JP7563395B2 - Light control device, image display device and display device - Google Patents

Description

The present disclosure relates to a dimmer device, an image display device equipped with such a dimmer device, and a display device equipped with such an image display device, and more specifically, to a display device used, for example, in a head mounted display (HMD).

In recent years, augmented reality (AR) technology, which synthesizes and presents virtual objects and various information as electronic information as additional information in a real environment (or a part of it), has been attracting attention. To realize this augmented reality technology, head-mounted displays, for example, are being considered as devices that present visual information. As an application field, work support in the real environment is expected, such as providing road guidance information and providing technical information to engineers performing maintenance. In particular, head-mounted displays are very convenient because they do not require hands to be occupied. Also, when you want to enjoy videos and images while moving outdoors, you can simultaneously capture the video and image and the external environment in your field of vision, allowing for smooth movement.

A virtual image display device (display device) that allows an observer to observe a two-dimensional image formed by an image forming device as an enlarged virtual image by a virtual image optical system is well known. Then, by forming a virtual image based on a two-dimensional image in this display device, the observer can see an image of the outside world and the formed virtual image superimposed. However, when the environment around the display device is very bright or depending on the content of the virtual image formed, a problem may occur in which the virtual image observed by the observer cannot be given sufficient contrast. Therefore, a means for solving such a problem, that is, a virtual image display device (display device) equipped with a dimming device, is well known from, for example, International Publication WO2019/097895.

WO2019/097895 publication

However, when the dimming layer constituting the dimming device is made of an electrochromic material or the like, and the light transmittance is changed by applying a color change based on an electrochemical oxidation-reduction reaction of the substance constituting the dimming layer that occurs when an electric current is passed through the dimming layer, it can be difficult to color (develop) or decolorize the dimming layer in a short time (for example, within 12 seconds for a goggle-shaped device, or within 4 seconds for a glasses-sized device).

Therefore, the object of the present disclosure is to provide a dimming device having a configuration capable of coloring or decoloring in a short period of time, an image display device equipped with such a dimming device, and a display device equipped with such an image display device.

In order to achieve the above object, the light control device of the present disclosure includes:
A first electrode,
a second electrode facing the first electrode;
A light-controlling layer sandwiched between a first electrode and a second electrode; and
A control unit for controlling coloring and decoloring of the light-controlling layer;
It is equipped with
The control unit includes a secondary battery, a control circuit, and a capacitor.
The control unit
(A) charging a capacitor with a secondary battery; and
(B) When the light-controlling layer is colored or decolored, a voltage is applied to the first electrode and the second electrode based on the discharge of the capacitor;
Control.

In order to achieve the above object, the image display device of the present disclosure comprises:
Image forming apparatus,
An optical device having a virtual image forming area in which a virtual image is formed based on light emitted from an image forming device;
a light control device that is disposed opposite at least the virtual image formation area and adjusts the amount of external light incident from the outside;
Equipped with
The dimmer comprises the dimmer of the present disclosure.

In order to achieve the above object, the display device of the present disclosure comprises:
A frame to be worn on the observer's head; and
an image display device attached to a frame;
A display device comprising:
The image display device includes:
Image forming apparatus,
An optical device having a virtual image forming area in which a virtual image is formed based on light emitted from an image forming device;
a light control device that is disposed opposite at least the virtual image formation area and adjusts the amount of external light incident from the outside;
It is equipped with
The dimmer comprises the dimmer of the present disclosure.

1A and 1B are a schematic front view and a schematic cross-sectional view taken along the arrow BB in FIG. 1A, respectively, of an optical device and a light control device (for the right eye) in the display device of Example 1. FIG. 2A and 2B are respectively a schematic front view of an optical device and a dimming device (for the right eye) in a modified example of the display device of Example 1, and a schematic cross-sectional view along arrow B-B in FIG. 2A, and FIG. 2C is a schematic front view of a modified example of the dimming device. 3A and 3B are respectively a schematic cross-sectional view of a dimming device similar to that taken along arrows B-B in FIG. 1A, and a schematic side view of a display device (mainly for the right eye) when the display device is viewed from the left eye side. FIG. 4 is a conceptual diagram of an image display device in the display device of the first embodiment. FIG. 5 is a conceptual diagram of a modified example of the image display device in the display device of the first embodiment. FIG. 6 is a schematic diagram of the display device of the first embodiment as viewed from above. FIG. 7 is a schematic diagram of the display device of the first embodiment as viewed from the front. FIG. 8 is a graph showing an example of the relationship between the voltage (ΔV) applied between the first electrode and the second electrode constituting the light control device and the light transmittance. The upper, middle and lower parts of Figure 9 are graphs showing the voltage applied between the first and second electrodes constituting the dimming device, the current flowing through the dimming layer, and the change in light transmittance over time, respectively, after coloring has begun. The upper, middle, and lower parts of Figure 10 are graphs showing the voltage applied between the first electrode and the second electrode that constitute the dimming device, the current flowing through the dimming layer, and the change in light transmittance over time, respectively, after the start of decolorization. 11A and 11B are conceptual diagrams of a control unit constituting the light control device in the first embodiment and a first modified example thereof. FIG. 12 is a conceptual diagram of a second modified example of the control unit constituting the light control device in the first embodiment. FIG. 13 is a block diagram showing an example of the circuit configuration of the control circuit and the secondary battery. 14A and 14B are respectively an equivalent circuit diagram of a charging circuit for charging a capacitor, and a diagram showing changes in potential at each point in the equivalent circuit diagram shown in FIG. 14A. 15A and 15B are equivalent circuit diagrams of a light transmittance/polarity control circuit for controlling the light transmittance and changing the polarity of the voltage applied to the first electrode and the second electrode. FIG. 16 is a circuit diagram of another drive circuit of the light control device 700. FIG. 17 is a diagram illustrating the operation of the drive circuit shown in FIG. FIG. 18 is a conceptual diagram of an image display device in the display device of the second embodiment. FIG. 19 is a conceptual diagram of an image display device in the display device of the third embodiment. FIG. 20 is a schematic cross-sectional view showing an enlarged portion of the reflection type volume hologram diffraction grating in the display device of the third embodiment. FIG. 21 is a conceptual diagram of an image display device in the display device of the fourth embodiment. FIG. 22 is a schematic diagram of the display device of the fifth embodiment as viewed from above. 23A and 23B are a schematic diagram of the display device of Example 6 as viewed from above and a schematic diagram of a circuit for controlling the illuminance sensor, respectively. 24A and 24B are a schematic diagram of the display device of Example 7 as viewed from above and a schematic diagram of a circuit for controlling the illuminance sensor, respectively. 25A and 25B are schematic cross-sectional views of the light control devices of Examples 8 and 9, respectively, similar to those taken along the arrows BB in FIG. 1A. FIG. 26 is a schematic diagram of yet another modified example of the display device of the first embodiment, viewed from above. 27A, 27B, 27C, 27D, 27E, 27F, 27G, and 27H are conceptual diagrams of an optical device in yet another modified example of the display device of Example 1. FIG. 28 is a conceptual diagram of an optical device in yet another modified example of the display device of the first embodiment. 29A and 29B are schematic diagrams of an optical device in a modified example of the display device of Example 5, viewed from above. 30A and 30B are schematic diagrams of an optical device in another modified example of the display device of Example 5, as viewed from above and from the side, respectively. FIG. 31 is a flow chart showing the flow of the operation of the light control device of the first embodiment.

Hereinafter, the present disclosure will be described based on examples with reference to the drawings, but the present disclosure is not limited to the examples, and various numerical values and materials in the examples are merely examples. The description will be made in the following order.
1. General description of the light control device of the present disclosure, the image display device of the present disclosure, and the display device of the present disclosure 2. Example 1 (light control device of the present disclosure, the image display device of the present disclosure, and the display device of the present disclosure, an optical device of 1-A structure, and an image forming device of a first configuration)
3. Example 2 (Modification of Example 1, Optical Device of 1-A Structure, Image Forming Apparatus of Second Configuration)
4. Example 3 (another modification of Example 1, optical device of 1-B structure, image forming device of first configuration)
5. Example 4 (another modification of Example 1, optical device of 1-B structure, image forming device of second configuration)
6. Example 5 (another modification of Example 1, optical device of second structure, image forming apparatus of second configuration)
7. Example 6 (Modification of Examples 1 to 5)
8. Example 7 (another modification of Examples 1 to 5)
9. Example 8 (Modification of Examples 1 to 7)
10. Example 9 (another modification of Examples 1 to 7)
11. Other

<General Description of the Light Control Device of the Present Disclosure, the Image Display Device of the Present Disclosure, and the Display Device of the Present Disclosure> In the light control device of the present disclosure, the light control device constituting the image display device of the present disclosure, and the light control device constituting the display device of the present disclosure (hereinafter, these may be collectively referred to as the "light control device, etc." of the present disclosure), the control unit further
(C) applying a voltage to the first electrode and the second electrode based on the secondary battery after a predetermined time has elapsed since the start of coloring or decoloring of the light-adjusting layer;
The above can be controlled.

In addition, after a predetermined time T ₀ ' has elapsed since the start of coloring of the light-adjusting layer, a voltage is applied to the first electrode and the second electrode based on the secondary battery, but after a specified time (coloring/specified time) T ₁ ' has elapsed, the application of voltage to the first electrode and the second electrode based on the secondary battery may be stopped. Similarly, after a predetermined time T ₀ '' has elapsed since the start of decoloring of the light-adjusting layer, a voltage is applied to the first electrode and the second electrode based on the secondary battery, but after a specified time (decoloring/specified time) T ₁ '' has elapsed, the application of voltage to the first electrode and the second electrode based on the secondary battery may be stopped. In some cases, application of a voltage based on the secondary battery to the first and second electrodes may be stopped after a predetermined time T ₀ ″ has elapsed since the start of decolorization of the light-adjusting layer. In addition, when the light-adjusting layer is colored, the value of the voltage based on the discharge of the capacitor applied to the first and second electrodes and the value of the voltage based on the secondary battery applied to the first and second electrodes after a predetermined time T ₀ ′ has elapsed since the start of coloration of the light-adjusting layer may be the same value, and the light transmittance value of the light-adjusting layer is specified by this voltage. The predetermined times T ₀ , T ₀ 'T ₀ '', the specified time (coloring-specified time) T ₁ ', and the specified time (decoloring-specified time) T ₁ '' may be stored in advance in the control unit. Alternatively, the control unit measures the voltage applied to the first and second electrodes, and when the voltage applied to the first and second electrodes reaches the predetermined voltage and the specified voltage, the control unit stores the predetermined time T ₀ , T ₀ 'T ₀ '', the specified time (coloring-specified time) T _{1 ''} . It may be determined that the predetermined time (decoloring predetermined time) T ₁ '' has been reached.

In the light control device and the like of the present disclosure including the above preferred embodiment,
the control unit applies a positive potential to one of the first electrode and the second electrode and applies a negative potential to the other of the first electrode and the second electrode when the light control device is colored;
The control unit may be configured to apply a voltage having a polarity opposite to that of the first electrode and the second electrode when the dimmer is decolorized. Specifically, when the dimmer is colored, for example, a voltage relatively higher than that of the first electrode is applied to the second electrode, and when the dimmer is decolorized, for example, a voltage relatively higher than that of the second electrode is applied to the first electrode.

Furthermore, in the light control device and the like of the present disclosure including the various preferred embodiments described above,
When the charge amount that gives the desired light transmittance to the light-controlling layer during coloring is _Q0 , the charge amount of the capacitor after charging is _Q1 , and the charge amount of the capacitor after a predetermined time _T0 has elapsed since the start of coloring or decoloring of the light-controlling layer is _Q2 ,
0.4<(Q ₁ -Q ₂ )/Q ₀
Preferably,
1.0≦(Q ₁ -Q ₂ )/Q ₀ ≦10.0
The control unit may be configured to control the _voltages applied to the capacitor, the first electrode, and the second electrode so as to satisfy the following:
0.1 (seconds) ≦T ₀ ≦12 (seconds)
Preferably,
0.8 (seconds) ≦T ₀ ≦4 (seconds)
In addition, the predetermined time T ₀ ′ from the start of coloring of the light control device and the predetermined time T ₀ ″ from the start of decoloring of the light control device may be the same or different. Specifically, for example,
_T0 = _T0 ' = _T0 "
or,
T ₀ ＝T ₀ '＞T ₀ ”
More specifically, the values of T ₀ , T ₀ ', and T ₀ '' may be determined by carrying out various tests on the light control device.

Furthermore, in the dimming device etc. of the present disclosure, including the various preferred forms described above, when a voltage is applied to the first electrode and the second electrode, a current can flow through the dimming layer.

Specifically, the light control layer can be a type of light shutter that utilizes the color change of a substance caused by the oxidation-reduction reaction of an inorganic or organic electrochromic material. More specifically, the light control layer can be a type that includes an inorganic or organic electrochromic material. That is, the light control layer can be a type that has a laminated structure of a reduction coloring layer made of tungsten oxide, an electrolyte layer made of tantalum oxide, and an oxidation coloring layer containing iridium atoms, and in this case, the oxidation coloring layer can be a type that is made of an iridium tin oxide-based material. Specifically, the light control layer can be a type that has a laminated structure of inorganic electrochromic material layers such as a WO ₃ layer/Ta ₂ O ₅ layer/Ir _x Sn _1-x O layer from the first electrode side, or a laminated structure of inorganic electrochromic material layers such as a WO ₃ layer/Ta ₂ O ₅ layer/IrO _x layer. Instead of the WO ₃ layer, a MoO ₃ layer or a V ₂ O ₅ layer can be used. In addition, instead of the IrO _x layer, a ZrO ₂ layer or a zirconium phosphate layer can be used, or a Prussian blue complex/nickel-substituted Prussian blue complex can be used, or organic materials such as viologen derivatives, polythiophene derivatives, and Prussian blue derivatives can be used. Other examples of materials constituting the oxidation coloring layer include inorganic materials such as rhodium oxide (RhO _x ), nickel oxide (NiO _x ), chromium oxide (CrO _x ), zirconium oxide (ZrO _x ), zirconium phosphate, nickel hydroxide, and copper chloride, and organic materials such as metal complexes (Prussian blue complexes, ruthenium purple complexes), pentacyanocarbonyl iron ferrate; amine derivatives, phenazine, and viologen derivatives. Other examples of the electrolyte layer include propylene carbonate, ionic liquids, gels such as acetonitrile, ethylene carbonate, and propylene carbonate, and ionic polymers.

Alternatively, the light control device can be a type of light shutter using an electrodeposition method (electrodeposition method or field deposition method) that applies the electrodeposition/dissociation phenomenon that occurs due to a reversible oxidation-reduction reaction of a metal (e.g., silver particles), that is, the light control layer can be in a form that includes an electrolyte containing metal ions. Such a light control device will be described in detail in Example 9.

The color colored by the dimmer can be a fixed color such as blue, brown, or black, or the light passing through the dimmer can be colored a desired color by the dimmer, and the color colored by the dimmer can be variable. Specifically, for example, a dimmer that is colored red, a dimmer that is colored green, and a dimmer that is colored blue can be stacked. In this specification, the concept of "coloring" includes "color development."

Furthermore, in the dimming device etc. of the present disclosure, including the various preferred forms described above, a form can be provided in which a moisture-retaining member (described in detail later) is disposed at least between the second electrode and the second substrate.

Furthermore, in the light control devices and the like of the present disclosure including the various preferred embodiments described above, when the effective area of the light control layer is A (mm ² ) and the capacitance of the capacitor is C (farads),
C/A>1×10 ^-6 (F/mm ² )
It is possible to make the above configuration satisfy the above.

Furthermore, in the dimming devices etc. of the present disclosure, including the various preferred forms described above, the capacitor may be configured to be composed of multiple capacitors connected in parallel.

Furthermore, in the light control device and the like of the present disclosure including the various preferred embodiments described above, the control circuit
A current limiting circuit that limits the current when discharging the secondary battery; and
a voltage control circuit (regulator) that controls the voltages applied from the capacitor and the secondary battery to the first electrode and the second electrode;
The above configuration may be adopted.

Furthermore, in the dimming devices etc. of the present disclosure, including the various preferred forms described above, the secondary battery may be a lithium ion battery.

Furthermore, the light control device and the like of the present disclosure including the various preferred embodiments described above include a first substrate and a second substrate opposed to the first substrate,
The first electrode is provided on a surface of the first substrate facing the second substrate,
The second electrode may be provided on a surface of the second substrate facing the first substrate.

Specific examples of materials constituting the transparent first and second substrates constituting the light control device include transparent glass substrates such as soda lime glass and white plate glass, plastic substrates, plastic sheets, and plastic films. Examples of plastics include polyethylene terephthalate, polyethylene naphthalate, polycarbonate, cellulose acetate, and other cellulose esters, fluorine-based polymers such as polyvinylidene fluoride or copolymers of polytetrafluoroethylene and hexafluoropropylene, polyethers such as polyoxymethylene, polyacetal, polystyrene, polyethylene, polypropylene, and polyolefins such as methylpentene polymers, polyimides such as polyamideimide and polyetherimide, polyamides, polyethersulfones, polyphenylene sulfide, polyvinylidene fluoride, tetraacetyl cellulose, brominated phenoxy, polyarylates, polysulfones, COP (cycloolefin polymers), TAC films, and highly transparent self-adhesive acrylic films. The plastic sheets and plastic films may be rigid enough not to bend easily, or may be flexible. When the first and second substrates are made of transparent plastic substrates, a barrier layer made of an inorganic or organic material may be formed on the inner surface of the substrate.

The second substrate also functions as, for example, a protective substrate. The first substrate faces the optical device with a gap therebetween, or faces the optical device without a gap therebetween, or doubles as a component of the optical device (for example, a protective component provided on the optical device). A hard coat layer made of an organic/inorganic mixed layer (for example, made of acrylic-modified colloidal silica particles, phenyl ketone-based and acrylate-based organic substances, and methyl ethyl ketone) or an anti-reflection film made of a fluorine-based resin may be formed on the outer surface of the second substrate.

If necessary, an inorganic material film may be provided on the second substrate, which provides rigidity to the second substrate and makes it less likely to be distorted when the light control device is assembled. Examples of inorganic material films include aluminum oxide, silicon oxide, silicon nitride, and niobium oxide. The inorganic material film may be formed, for example, by a PVD method, a CVD method, a laser ablation method, or an atomic layer deposition method (ALD method).

The first and second substrates are sealed and bonded at their outer edges with a sealant. As the sealant, various resins such as thermosetting, photosetting, moisture-curing, and anaerobic curing types can be used, including epoxy resins, urethane resins, acrylic resins, vinyl acetate resins, ene-thiol resins, silicone resins, and modified polymer resins.

In the light control device and the like of the present disclosure including the various preferred embodiments described above,
The first electrode is composed of a plurality of strip-shaped first electrode segments extending in a first direction,
the second electrode is composed of a plurality of strip-shaped second electrode segments extending in a second direction different from the first direction;
The light blocking rate of the portion of the light control device corresponding to the overlapping region of the first electrode segment and the second electrode segment (the minimum unit region where the light blocking rate of the light control device changes) can be controlled based on the control of the voltage applied to the first electrode segment and the second electrode segment. That is, the light blocking rate can be controlled based on a simple matrix method. An example of a mode in which the first direction and the second direction are perpendicular to each other can be exemplified. When the light control device is colored, for example, a voltage higher than that applied to the first electrode is applied to the second electrode, and when the light control device is bleached, for example, a voltage higher than that applied to the second electrode is applied to the first electrode.

Alternatively, a thin film transistor (TFT) may be provided in each of the minimum unit areas to control the light blocking rate of the minimum unit area in which the light blocking rate of the light control device changes. That is, the light blocking rate may be controlled based on an active matrix method. Alternatively, either one of the first electrode and the second electrode may be a so-called solid electrode (unpatterned electrode), or both may be so-called solid electrodes (unpatterned electrodes).

As mentioned above, the first electrode may be patterned or unpatterned, and the second electrode may be patterned or unpatterned. Examples of materials constituting the first electrode and the second electrode include transparent conductive materials, specifically indium-tin composite oxides (ITO, indium tin oxide, including Sn-doped In ₂ O ₃ , crystalline ITO and amorphous ITO), fluorine-doped SnO ₂ (FTO), IFO (F-doped In ₂ O ₃ ), antimony-doped SnO ₂ (ATO), SnO ₂ , ZnO (including Al-doped ZnO and B-doped ZnO), indium-zinc composite oxides (IZO, indium zinc oxide), spinel-type oxides, oxides having a YbFe ₂ O ₄ structure, polyaniline, polypyrrole, polythiophene and other conductive polymers, but are not limited to these. Furthermore, two or more of these can be used in combination. Alternatively, the first electrode and the second electrode can be made of a metal such as gold, silver, copper, aluminum, nickel, titanium, or a thin wire made of an alloy. An auxiliary electrode (first auxiliary electrode) may be provided on the first electrode, or an auxiliary electrode (second auxiliary electrode) may be provided on the second electrode. The auxiliary electrode can be made of a metal such as gold, silver, copper, aluminum, nickel, titanium, or an alloy thereof, or the auxiliary electrode can be formed using silver paste or copper paste. The auxiliary electrodes (first auxiliary electrode and second auxiliary electrode) are required to have lower electrical resistance than the first electrode and the second electrode. The first electrode, the second electrode, and the auxiliary electrodes (first auxiliary electrode and second auxiliary electrode) can be formed based on various physical vapor deposition methods (PVD methods) such as vacuum deposition and sputtering, various chemical vapor deposition methods (CVD methods), various coating methods, various printing methods, etc., and patterning can be performed by any method such as etching, lift-off, and methods using various masks.

Either one of the first and second substrates can be configured to double as a light guide plate (which constitutes an optical device, as described later). By using such a configuration, the weight of the entire display device can be reduced, and there is no risk of the user (observer) of the display device feeling uncomfortable. Either one of the first and second substrates can be configured to be thinner than the other. In a display device equipped with a dimming device, the size and position of the area where the dimming device actually dims can be determined based on a signal for displaying an image in the image forming device. The size of the dimming device may be the same as that of the optical device, or it may be larger or smaller. In short, it is sufficient that the second deflection means (which is a virtual image forming area, as described later) is located within the orthogonal projection image of the dimming device.

In some cases, the dimming device can be detachably arranged. In order to detachably arrange the dimming device, for example, a screw made of transparent plastic can be used to attach the dimming device to a frame, or a groove can be cut in the frame and the dimming device can be engaged in the groove, or a magnet can be attached to the frame to attach the dimming device to the frame, or a slide part can be provided in the frame and the dimming device can be fitted into the slide part. Alternatively, at least one of the first substrate and the second substrate can be attached to the frame, for example. Alternatively, the dimming device can be attached to the optical device. That is, the dimming device can be attached to the optical device in a state of close contact, or with a gap. In this case, the light guide plate and one of the substrates constituting the dimming device can be sealed and bonded by a sealing member at the outer edge. As the sealing member, various resins such as epoxy resins, urethane resins, acrylic resins, vinyl acetate resins, ene-thiol resins, silicone resins, modified polymer resins, etc., such as thermosetting, photosetting, moisture-curing, and anaerobic curing resins, can be used. However, the present invention is not limited to these. From the observer side, the optical device and the light control device may be arranged in this order, or the light control device and the optical device may be arranged in this order. In addition, a connector may be attached to the light control device (specifically, a connector may be attached to the first electrode or the second electrode), and the light control device may be electrically connected to a control unit for controlling the light blocking rate (light transmittance) of the light control device (for example, the control device may be included in a control device for controlling an image forming device) via this connector and wiring.

The maximum light transmittance of the light control device may be 50% or more, and the minimum light transmittance of the light control device may be 30% or less. The upper limit of the maximum light transmittance of the light control device may be 99%, and the lower limit of the minimum light transmittance of the light control device may be 1%.
(Light transmittance) = 100 (%) - (Shading rate)
This is in a relationship.

When the dimmer is in operation, the shading rate of the other areas of the dimmer can be "1" when the shading rate of the virtual image projection area of the dimmer, which includes the projected image of the virtual image onto the dimmer, is set to "1", or can be, for example, 0.95 or less. Alternatively, the shading rate of the other areas of the dimmer can be, for example, 30% or less. On the other hand, when the dimmer is in operation, the shading rate of the virtual image projection area of the dimmer can be 35% to 99%, for example, 80%. In this way, the shading rate of the virtual image projection area may be constant or may be changed depending on the illuminance of the environment in which the display device is placed.

In the display device etc. of the present disclosure, the light blocking rate may change gradually (i.e., continuously), or may be configured to change in a step-like manner depending on the arrangement and shape of the electrodes, or may be configured to change continuously or step-wise from a constant value. That is, the light control device may be in a state with a color gradation, a state in which the color changes stepwise, or a state in which the color changes continuously or stepwise from a constant color state. The light blocking rate can be controlled by the voltage applied to the first electrode and the second electrode. The potential difference between the first electrode and the second electrode may be controlled, or the voltage applied to the first electrode and the voltage applied to the second electrode may be controlled independently. When adjusting the light blocking rate, a test pattern may be displayed on the optical device.

The light control device etc. of the present disclosure further includes an illuminance sensor (or a second illuminance sensor) that measures the illuminance of the environment in which the display device is placed, and the control unit can start coloring and decoloring of the light control device and set the light transmittance based on the measurement result of the illuminance sensor (or the second illuminance sensor). Alternatively, the light control device etc. may further include a switch etc. that can be operated by an observer, and the control unit can start coloring and decoloring of the light control device and set the light transmittance based on the observer's operation of the switch etc. Alternatively, for example, the display device further includes a microphone, and the start of coloring and decoloring of the light control device can be controlled by voice input via the microphone. Specifically, the start of coloring and decoloring of the light control device may be controlled by instructions based on the observer's voice. Alternatively, the display device further includes an infrared input/output device, and the start of coloring and decoloring of the light control device may be controlled by the infrared input/output device. Specifically, the infrared ray input/output device may detect the blinking of the observer to control the start of coloring and decoloring of the light control device. Alternatively, in the image display device or display device of the present disclosure, the control unit may start coloring and decoloring of the light control device and set the light transmittance in synchronization with the start of image formation or the end of image formation in the image forming device.

As described above, the display device of the present disclosure may further include an illuminance sensor (environmental illuminance measurement sensor) that measures the illuminance of the environment in which the display device is placed, and the light blocking rate of the dimming device may be controlled based on the measurement results of the illuminance sensor (environmental illuminance measurement sensor). Alternatively, the display device may further include an illuminance sensor (environmental illuminance measurement sensor) that measures the illuminance of the environment in which the display device is placed, and the brightness of the image formed by the image forming device may be controlled based on the measurement results of the illuminance sensor (environmental illuminance measurement sensor). These configurations may be combined.

Alternatively, the display device of the present disclosure may further include a second illuminance sensor (sometimes referred to as a "transmitted light illuminance measurement sensor" for convenience) that measures the illuminance based on the light transmitted through the light control device from the external environment, and may control the light blocking rate of the light control device based on the measurement result of the second illuminance sensor (transmitted light illuminance measurement sensor). Alternatively, the display device of the present disclosure may further include a second illuminance sensor (transmitted light illuminance measurement sensor) that measures the illuminance based on the light transmitted through the light control device from the external environment, and may control the brightness of the image formed by the image forming device based on the measurement result of the second illuminance sensor (transmitted light illuminance measurement sensor). It is preferable that the second illuminance sensor (transmitted light illuminance measurement sensor) is disposed closer to the observer than the optical device. At least two second illuminance sensors (transmitted light illuminance measurement sensors) may be disposed to measure the illuminance based on the light transmitted through the high light blocking rate portion and the illuminance based on the light transmitted through the low light blocking rate portion. These forms may be combined. Furthermore, these configurations may be combined with a configuration in which control is performed based on the measurement results of the above-mentioned illuminance sensor (environmental illuminance measuring sensor).

The illuminance sensor (ambient illuminance measurement sensor, transmitted light illuminance measurement sensor) may be constructed from a well-known illuminance sensor, and the illuminance sensor may be controlled based on a well-known control circuit.

An observer observes the brightness of the light that has passed through the dimmer and the optical device, and can manually control and adjust the light transmittance (shading rate) by operating a switch or the like (specifically, a switch, button, dial, slider, knob, etc., and the same applies below), or can control and adjust the shading rate based on the measurement results of a second illuminance sensor (transmitted light illuminance measurement sensor) that measures the illuminance based on the light that has passed through the dimmer from the external environment. The light transmittance (shading rate) can be controlled and adjusted by controlling the voltage applied to the first electrode and the second electrode. At least two second illuminance sensors (transmitted light illuminance measurement sensors) may be arranged to measure the illuminance based on the light that has passed through the high shading rate portion and the illuminance based on the light that has passed through the low shading rate portion.

The optical device is semi-transmissive (see-through). Specifically, at least the part of the optical device facing the observer's eyeball (pupil) is semi-transmissive (see-through), and the outside scene can be seen through this part of the optical device and the dimming device. Note that "semi-transmissive" does not mean that 1/2 (50%) of the incident light is transmitted or reflected, but rather that a part of the incident light is transmitted and the rest is reflected. The display device may have one image display device (single-eye type) or two (binocular type). When two image display devices are provided, the light blocking rate of one dimming device and the light blocking rate of the other dimming device can be equalized by adjusting the voltage applied to the first electrode and the second electrode in each of the one dimming device and the other dimming device. The light blocking rate of one dimmer and the light blocking rate of the other dimmer can be controlled, for example, based on the measurement results of the second illuminance sensor (transmitted light illuminance measurement sensor) that measures the illuminance based on the light transmitted through the dimmer from the external environment described above, or alternatively, an observer can observe the brightness of the light that has passed through one dimmer and the optical device and the brightness of the light that has passed through the other dimmer and the optical device, and manually control and adjust the light blocking rate by operating a switch, etc. When adjusting the light blocking rate, a test pattern may be displayed on the optical device.

Furthermore, in the dimming device etc. of the present disclosure, which includes the preferred forms and configurations described above, the dimming device can be curved, which allows the dimming device to be easily and securely attached to the image display device or display device.

However, when the dimming layer constituting the dimming device is made of an electrochromic material and the light transmittance is changed by applying the color change of the substance generated by the oxidation-reduction reaction of the electrochromic material, a phenomenon occurs in which the color change of the dimming layer does not occur if the moisture inside the dimming layer disappears. Therefore, in the dimming device etc. of the present disclosure including the preferred form described above, for example, the first substrate is disposed closer to the observer than the second substrate, and a moisture retaining member is disposed at least between the second electrode and the second substrate as described above, and in this case, the end face of the moisture retaining member can be exposed to the outside. In addition, at least a part of the end (side surface) of the dimming device can be configured to ...

The second electrode is formed from above the light-adjusting layer onto the first substrate and spaced apart from the first electrode, and the moisture-retaining member can be configured to cover at least the second electrode and the light-adjusting layer.

The resin constituting the moisture-retaining member may be an acrylic resin, a silicone resin, or a urethane resin. Alternatively, the moisture-retaining member may be made of an ultraviolet-curable resin. Alternatively, the moisture-retaining member may be made of a material called OCA (Optical Clear Adhesive). Alternatively, the material constituting the moisture-retaining member may be at least one material selected from the group consisting of epoxy resins, polyvinyl resins such as polyvinyl alcohol and polyvinyl butyral, moisture-containing gels, and porous materials. An example of the moisture-containing gel is a mixture of sodium polyacrylate and polyethylene glycol having a dendron group at the end, and an example of the porous material is silica surface-modified with an organic silane compound. The "moisture-retaining member" may also be referred to as a proton supplying member, a transparent adhesive member capable of retaining moisture, or a transparent sealant capable of retaining moisture. Depending on the form of the moisture retaining member, for example, if the moisture retaining member is sheet-shaped, the second substrate and the second electrode, and the second substrate and the sealant can be bonded together via the moisture retaining member, or a thermoplastic ultraviolet curing type moisture retaining member can be used. Alternatively, if the moisture retaining member is liquid, the moisture retaining member can be applied from the second electrode to the sealant, pre-cured as necessary, and then the second substrate can be superimposed on the moisture retaining member while applying pressure as necessary, and the moisture retaining member can be cured by ultraviolet light. Alternatively, depending on the material used, the moisture retaining member can be bonded from the second electrode to the sealant based on a thermal lamination method or the like.

The sealant functions as a moisture barrier layer, but a part of the sealant can be composed of an auxiliary electrode. In this case, the auxiliary electrode can be composed of a first auxiliary electrode formed on the first electrode, and a second auxiliary electrode formed on the second electrode at a distance from the first auxiliary electrode. In this way, by providing the auxiliary electrode, an appropriate voltage can be easily applied to the first electrode and the second electrode, and the occurrence of a voltage drop in the first electrode or the second electrode can be suppressed, so that the occurrence of unevenness during coloring of the light control device can be reduced. The same applies below.

Alternatively, the sealant may be made of resin, in which case the Young's modulus of the resin constituting the sealant may be 1×10 ⁷ Pa or less, and further, in these cases, an auxiliary electrode may be provided inside a portion of the sealant. Here, the auxiliary electrode may be made of a first auxiliary electrode formed on the first electrode, and a second auxiliary electrode formed on the second electrode at a distance from the first auxiliary electrode. The resin constituting the sealant may be one selected from the group consisting of various resins such as thermosetting, photosetting, moisture-curing, and anaerobic curing, for example, acrylic resins, urethane resins, silicone resins, fluorine resins, vinyl acetate resins, ene-thiol resins, modified polymer resins, polyimide resins, and epoxy resins. When the sealant is made of resin, an inorganic filler such as silica or alumina may be added to the resin.

Alternatively, the sealant may be configured to have a convex portion provided on the edge of the first substrate, and in this case, an auxiliary electrode may be provided inside a portion of the sealant. Here, the auxiliary electrode may be configured to have a first auxiliary electrode formed on the first electrode, and a second auxiliary electrode formed on the second electrode at a distance from the first auxiliary electrode. The convex portion on the edge of the first substrate may be formed, for example, by heat pressing the edge of the first substrate using a heat press device, or may be formed by various physical vapor deposition methods (PVD methods), various chemical vapor deposition methods (CVD methods), or various printing methods.

Furthermore, the cross-sectional shape of the sealant can be a shape that narrows as it approaches the second substrate. By making the cross-sectional shape of the sealant such a shape, it is possible to avoid problems such as air bubbles being mixed in under the moisture retention member when the moisture retention member is placed on at least the second electrode and the moisture retention member extension portion extending from the moisture retention member is placed on the sealant. Such a cross-sectional shape of the sealant can be formed based on various methods, such as forming the sealant based on a printing method or forming the sealant based on a sputtering method using a metal mask.

Furthermore, it is desirable that the Young's modulus of the material (specifically, resin) constituting the moisture retention member is 1×10 ⁶ Pa or less, which can absorb various steps occurring inside the light control device and reduce the variation in thickness of the moisture retention member at the center of the light control device and the variation in thickness of the extension part of the moisture retention member (i.e., the entire distance between the first substrate and the second substrate can be made uniform), thereby preventing the occurrence of deterioration in visibility. Specifically, when the outside world is viewed through the light control device, it is possible to suppress the occurrence of distortion or deviation in the image of the outside world.

The moisture-retaining member is placed on at least the second electrode, and the moisture-retaining member extension portion extending from the moisture-retaining member is placed on the sealant, specifically, for example, by adhering or bonding the moisture-retaining member to the second electrode, and adhering or bonding the moisture-retaining member extension portion to the sealant. In addition, a second substrate is placed on the moisture-retaining member and the moisture-retaining member extension portion, specifically, for example, by adhering or bonding the second substrate to the moisture-retaining member and the moisture-retaining member extension portion.

The region in the light control device where the light blocking rate is increased may be the entire region of the light control device, or a part of the region of the light control device. That is, the light blocking rate of the region of the light control device facing the region of the second deflection means where the virtual image is actually formed (for example, a part of the region of the second deflection means described later) may be controlled. In other words, when a virtual image is formed in a part of the virtual image forming region based on the light emitted from the image forming device, the light control device may be controlled so that the light blocking rate of the virtual image projection region of the light control device (the region of the light control device corresponding to the virtual image forming region in the optical device) containing the projected image of the virtual image onto the light control device is higher than the light blocking rate of other regions of the light control device. In addition, the position of the virtual image projection region in the light control device is not fixed, but changes depending on the formation position of the virtual image, and the number of virtual image projection regions may also change depending on the number of virtual images (or the number of a series of virtual image groups, the number of blocked virtual image groups, etc.).

In the display device of the present disclosure including the various preferred forms described above (hereinafter, these may be collectively referred to as the "display device, etc. of the present disclosure"), the frame includes a front portion disposed in front of the viewer, two temple portions rotatably attached to both ends of the front portion via hinges, and a nose pad portion, and the light control device may be disposed in the front portion, in which case the optical device may be attached to the light control device. Alternatively, the optical device may be attached to the front portion, in which case the light control device may be attached to the optical device. Furthermore, in these cases, the front portion may have a rim portion, and the light control device may be fitted into the rim portion, or the optical device may be fitted into the rim portion, in which case the optical device may be fixed to the rim portion using an adhesive that is permeable to water vapor. Alternatively, the space between the light control device and the optical device may be in communication with the outside. In the display device, etc. of the present disclosure, the optical device may be arranged in the order of the light control device, or the light control device, and the optical device, from the viewer side.

Examples of adhesives that can transmit water vapor include adhesives based on non-polar materials such as silicones, ethylene-vinyl alcohol copolymers, and styrene-butadiene, which have high water vapor diffusion properties, and examples of moisture permeability of such adhesives include 2×10 grams/ ^m2 -day to 1.1× ¹⁰³ grams/ ^m2 -day. The moisture permeability can be measured based on JIS K7129:2008, and the test is performed on a 50 mm×50 mm test piece under conditions of a test temperature of 25°C±0.5°C and a relative humidity of 90±2%. The measurement is performed using a wet/dry sensor.

Furthermore, in the image display device of the present disclosure including the preferred embodiment described above, and in the display device of the present disclosure including the preferred embodiment described above, the optical device is
a light guide plate through which light incident from an image forming device propagates through the inside thereof by total reflection and is then emitted toward an observer;
a first deflection means for deflecting light incident on the light guide plate such that the light incident on the light guide plate is totally reflected inside the light guide plate; and
a second deflection means for deflecting the light propagated by total reflection inside the light guide plate so as to emit the light propagated by total reflection inside the light guide plate from the light guide plate;
The optical device may be configured to include the above. For convenience, such an optical device is called the "optical device of the first structure". The second deflection means a virtual image forming region of the optical device. The second deflection means (virtual image forming region) is located within the projected image of the dimming device. The term "total reflection" means total internal reflection or total reflection within the light guide plate. The light incident from the image forming device is emitted toward the observer after propagating through the inside of the light guide plate by total reflection, and the virtual image forming region of the optical device is configured by the second deflection means. The second deflection means (virtual image forming region) may be located within the projected image of the dimming device, or the dimming device may be located within the projected image of the second deflection means (virtual image forming region).

As described above, in an optical device of the first structure, the first deflection means can be configured to reflect light incident on the light guide plate, and the second deflection means can be configured to transmit and reflect (multiple times) the light that has propagated inside the light guide plate by total reflection. In this case, the first deflection means can be configured to function as a reflecting mirror, and the second deflection means can be configured to function as a semi-transmitting mirror. For convenience, such an optical device of the first structure will be referred to as an "optical device of 1-A structure."

In such an optical device of the 1-A structure, the first deflection means is, for example, made of a metal including an alloy, and can be composed of a light reflecting film (a kind of mirror) that reflects the light incident on the light guide plate, or a diffraction grating (for example, a hologram diffraction grating film) that diffracts the light incident on the light guide plate. Alternatively, the first deflection means can be composed of, for example, a multilayer laminate structure in which a large number of dielectric laminate films are laminated, a half mirror, or a polarizing beam splitter. The second deflection means can be composed of a multilayer laminate structure in which a large number of dielectric laminate films are laminated, a half mirror, a polarizing beam splitter, or a hologram diffraction grating film. The first deflection means and the second deflection means are disposed inside the light guide plate (built into the light guide plate), but in the first deflection means, the parallel light incident on the light guide plate is reflected or diffracted so that the parallel light incident on the light guide plate is totally reflected inside the light guide plate. On the other hand, in the second deflection means, the parallel light propagating inside the light guide plate by total reflection is reflected or diffracted (multiple times) and emitted as parallel light from the light guide plate. In some cases, one of the first deflection means and the second deflection means may be disposed on the outer surface of the light guide plate.

Alternatively, the first deflection means may diffract the light incident on the light guide plate, and the second deflection means may diffract the light propagated inside the light guide plate by total reflection multiple times. In this case, the first deflection means and the second deflection means may be configured to be made of diffraction grating elements, and the diffraction grating elements may be made of reflective diffraction grating elements or transmissive diffraction grating elements, or one of the diffraction grating elements may be made of a reflective diffraction grating element and the other of the diffraction grating elements may be made of a transmissive diffraction grating element. The diffraction grating element may be a volume hologram diffraction grating. A volume hologram diffraction grating means a hologram diffraction grating that diffracts and reflects only +1-order diffracted light. For convenience, the first deflection means made of a hologram diffraction grating may be called the "first diffraction grating member," and the second deflection means made of a hologram diffraction grating may be called the "second diffraction grating member." For convenience, such an optical device of the first structure is called an "optical device of the 1-B structure". The interference fringes of the holographic diffraction grating layer extend approximately in the Y direction. Here, in the light guide plate, the X direction is the longitudinal direction (horizontal direction) of the light guide plate, the Y direction is the width direction (height direction, vertical direction) of the light guide plate, and the Z direction is the thickness direction of the light guide plate.

In the optical device of the 1-B structure, a third deflection means may be provided into which the light emitted from the first deflection means is incident. The light emitted from the third deflection means is incident on the second deflection means. Here, the first deflection means, the second deflection means and the third deflection means are each made of a volume hologram diffraction grating, and when the wave vector obtained when the wave vector of the first deflection means is projected onto the light guide plate is k ^v ₁ , the wave vector obtained when the wave vector of the second deflection means is projected onto the light guide plate is k ^v ₂ , and the wave vector obtained when the wave vector of the third deflection means is projected onto the light guide plate is k ^v ₃ ,
k ^v ₁ + k ^v ₂ + k ^v ₃ = 0
It is preferable to satisfy the following:

The image display device in the display device etc. of the present disclosure can display a monochromatic (e.g., green or blue) image. In this case, for example, the angle of view can be divided into two (more specifically, for example, into equal parts), and the first deflection means can be configured to have two diffraction grating members stacked on each other corresponding to the two divided angle of view. Alternatively, when displaying a color image, the first diffraction grating member or the second diffraction grating member can be configured to have P diffraction grating layers stacked on each other, each made of a hologram diffraction grating, in order to correspond to the diffraction reflection of P types of light having different wavelength bands (or wavelengths) of P types (for example, P=3, which is three types: red, green, and blue). Each diffraction grating layer has an interference fringe corresponding to one type of wavelength band (or wavelength). Alternatively, the first diffraction grating member or the second diffraction grating member made of one diffraction grating layer can be configured to have P types of interference fringes formed thereon in order to correspond to the diffraction reflection of P types of light having different wavelength bands (or wavelengths). Alternatively, for example, a structure may be adopted in which a diffraction grating member made of a diffraction grating layer made of a hologram diffraction grating that diffracts and reflects light having a red wavelength band (or wavelength) is disposed on the first light guide plate, a diffraction grating member made of a diffraction grating layer made of a hologram diffraction grating that diffracts and reflects light having a green wavelength band (or wavelength) is disposed on the second light guide plate, and a diffraction grating member made of a diffraction grating layer made of a hologram diffraction grating that diffracts and reflects light having a blue wavelength band (or wavelength) is disposed on the third light guide plate, and these first light guide plate, second light guide plate, and third light guide plate are laminated with gaps. Alternatively, the angle of view may be divided into three equal parts, for example, and the first diffraction grating member or the second diffraction grating member may be configured to have a diffraction grating layer corresponding to each angle of view laminated. By adopting these configurations, it is possible to increase the diffraction efficiency, increase the diffraction acceptance angle, and optimize the diffraction angle when light having each wavelength band (or wavelength) is diffracted and reflected by the first diffraction grating member or the second diffraction grating member. It is preferable to provide a protective member to prevent the viewer from touching the hologram diffraction grating. The first substrate or the second substrate constituting the light control device may also serve as the protective member.

Photopolymer materials can be used as materials for the first and second diffraction grating members. The materials and basic structure of the first and second diffraction grating members made of holographic diffraction gratings may be the same as those of conventional holographic diffraction gratings. The diffraction grating member has interference fringes formed from its interior to its surface, and the method for forming the interference fringes themselves may be the same as conventional methods. Specifically, for example, an object beam is irradiated from a first predetermined direction on one side of a member (e.g., a photopolymer material) constituting the diffraction grating member, and at the same time, a reference beam is irradiated from a second predetermined direction on the other side of the member constituting the diffraction grating member, and the interference fringes formed by the object beam and the reference beam are recorded inside the member constituting the diffraction grating member. By appropriately selecting the first predetermined direction, the second predetermined direction, and the wavelengths of the object beam and the reference beam, the desired pitch of the interference fringes on the surface of the diffraction grating member and the desired inclination angle (slant angle) of the interference fringes can be obtained. The inclination angle of the interference fringes means the angle between the surface of the diffraction grating member (or the diffraction grating layer) and the interference fringes. When the first diffraction grating member and the second diffraction grating member are constructed from a laminated structure of a P-layer diffraction grating layer made of a hologram diffraction grating, such a lamination of diffraction grating layers may be performed by laminating (adhering) the P-layer diffraction grating layers, for example, using an ultraviolet curing adhesive, after preparing each of the P-layer diffraction grating layers separately. The P-layer diffraction grating layer may also be prepared by preparing one diffraction grating layer using a photopolymer material having adhesive, and then successively attaching photopolymer materials having adhesive thereon to prepare a diffraction grating layer. The prepared diffraction grating layer may be irradiated with an energy beam as necessary to polymerize and fix the monomer in the photopolymer material that remains unpolymerized when the diffraction grating layer is irradiated with the object light and reference light. Also, heat treatment may be performed as necessary to stabilize the layer.

Alternatively, in the image display device in the display device or the like of the present disclosure, the optical device may be configured to be composed of a semi-transmitting mirror into which the light emitted from the image forming device is incident and emitted toward the observer's pupil, or may be configured to be composed of a polarizing beam splitter (PBS). The semi-transmitting mirror or polarizing beam splitter constitutes the virtual image forming area of the optical device. The light emitted from the image forming device may be configured to propagate through the air and enter the semi-transmitting mirror or polarizing beam splitter, or may be configured to propagate inside a transparent member such as a glass plate or plastic plate (specifically, a member made of the same material as the material constituting the light guide plate described later) and enter the semi-transmitting mirror or polarizing beam splitter. The semi-transmitting mirror or polarizing beam splitter may be attached to the image forming device via this transparent member, or the semi-transmitting mirror or polarizing beam splitter may be attached to the image forming device via a member other than this transparent member. For convenience, such an optical device is called an "optical device of the second structure". The semi-transmitting mirror may be the first deflection means in the optical device of the 1-A structure, for example, a light reflecting film (a type of mirror) made of a metal containing an alloy and reflecting light, or a diffraction grating (for example, a hologram diffraction grating film). Alternatively, the optical device may be configured to be made of a prism into which the light emitted from the image forming device is incident and which emits the light toward the pupil of the observer.

In the image display device in the display device etc. of the present disclosure, including the various preferred forms and configurations described above, the image forming device can be configured to have a plurality of pixels arranged in a two-dimensional matrix. For convenience, such an image forming device configuration is referred to as the "image forming device of the first configuration."

As the image forming device of the first configuration, for example, an image forming device composed of a reflective spatial light modulator and a light source; an image forming device composed of a transmissive spatial light modulator and a light source; an image forming device composed of light emitting elements such as an organic EL (Electro Luminescence) element, an inorganic EL element, a light emitting diode (LED), and a semiconductor laser element can be mentioned. Among them, an image forming device composed of an organic EL light emitting element (organic EL display device), an image forming device composed of a reflective spatial light modulator and a light source, and an image forming device composed of a light emitting element are preferable. As the spatial light modulator, a light valve, for example, a transmissive or reflective liquid crystal display device such as LCOS (Liquid Crystal On Silicon), and a digital micromirror device (DMD) can be mentioned, and as the light source, a light emitting element can be mentioned. Furthermore, the reflective spatial light modulator can be configured to be composed of a liquid crystal display device and a polarizing beam splitter that reflects a part of the light from the light source and guides it to the liquid crystal display device, and also passes a part of the light reflected by the liquid crystal display device and guides it to an optical device (for example, a light guide plate). As the light emitting element constituting the light source, a red light emitting element, a green light emitting element, a blue light emitting element, and a white light emitting element can be mentioned. Alternatively, the red light, green light, and blue light emitted from the red light emitting element, the green light emitting element, and the blue light emitting element may be mixed and luminance uniformed using a light pipe to obtain white light. Examples of the light emitting element include a semiconductor laser element, a solid-state laser, and an LED. The number of pixels may be determined based on the specifications required for the image display device, and specific values of the number of pixels may be 320×240, 432×240, 640×480, 854×480, 1024×768, and 1920×1080. In the image forming device of the first configuration, a diaphragm may be arranged at the position of the front focus (the focus on the image forming device side) of the lens system (described later), and this diaphragm corresponds to the image output section from which the image is output from the image forming device.

Alternatively, in the image display device in the display device or the like of the present disclosure including the preferred forms and configurations described above, the image forming device may be configured to include a light source and a scanning means for scanning the light emitted from the light source to form an image. For convenience, such an image forming device is referred to as an "image forming device of the second configuration."

The light source in the image forming apparatus of the second configuration may be a light emitting element, specifically a red light emitting element, a green light emitting element, a blue light emitting element, or a white light emitting element. Alternatively, the red light, green light, and blue light emitted from the red light emitting element, the green light emitting element, and the blue light emitting element may be mixed and luminance uniformed using a light pipe to obtain white light. Examples of the light emitting element include a semiconductor laser element, a solid-state laser, and an LED. The number of pixels (virtual pixels) in the image forming apparatus of the second configuration may also be determined based on the specifications required for the image display device. Specific values of the number of pixels (virtual pixels) may include 320×240, 432×240, 640×480, 854×480, 1024×768, and 1920×1080. In addition, when a color image is displayed and the light source is composed of red light emitting elements, green light emitting elements, and blue light emitting elements, it is preferable to perform color synthesis using, for example, a cross prism. Examples of the scanning means include a MEMS (Micro Electro Mechanical Systems) mirror or a galvanometer mirror having a micromirror that can rotate in two dimensions, which horizontally and vertically scans the light emitted from the light source. In the image forming device of the second configuration, the MEMS mirror or the galvanometer mirror can be disposed at the front focal point (the focal point on the image forming device side) of the lens system (described later), and the MEMS mirror or the galvanometer mirror corresponds to the image emitting section from which the image is emitted from the image forming device.

In the image forming device of the first configuration or the image forming device of the second configuration, the light that has been made into multiple parallel beams by the optical system (an optical system that makes the emitted light parallel, and may be called a "parallel light emission optical system", specifically, for example, a collimated optical system or a relay optical system) is made to enter the light guide plate. The requirement that the light be parallel is based on the need to preserve the light wavefront information when these beams enter the light guide plate even after they are emitted from the light guide plate via the first deflection means and the second deflection means. To generate multiple parallel beams, specifically, for example, the light emission unit of the image forming device may be positioned at the focal length (position) of the parallel light emission optical system. The parallel light emission optical system has the function of converting pixel position information into angle information in the optical system of the optical device. Examples of parallel light emission optical systems include optical systems that have positive optical power overall, which are formed by using a convex lens, a concave lens, a free-form prism, and a hologram lens, either alone or in combination. A light blocking section having an opening may be disposed between the parallel light emitting optical system and the light guide plate to prevent undesired light from being emitted from the parallel light emitting optical system and entering the light guide plate.

The light guide plate has two parallel surfaces (first and second surfaces) extending parallel to the axis of the light guide plate (longitudinal direction, horizontal direction, corresponding to the X direction). The width direction (height direction, vertical direction) of the light guide plate corresponds to the Y direction. The thickness direction of the light guide plate corresponds to the Z direction. When the surface of the light guide plate where the light is incident is the light guide plate incident surface and the surface of the light guide plate where the light is emitted is the light guide plate exit surface, the first surface may constitute the light guide plate incident surface and the light guide plate exit surface, or the first surface may constitute the light guide plate incident surface and the second surface may constitute the light guide plate exit surface. The first deflection means is disposed on the first surface or the second surface of the light guide plate, and the second deflection means is disposed on the first surface or the second surface of the light guide plate. The interference fringes of the diffraction grating member extend approximately parallel to the Y direction. Examples of materials constituting the light guide plate include optical glass such as quartz glass and BK7, glass including soda lime glass and white plate glass, and plastic materials (for example, PMMA, polycarbonate resin, laminated structure of polycarbonate resin and acrylic resin, acrylic resin, cycloolefin polymer, amorphous polypropylene resin, styrene resin including AS resin). The shape of the light guide plate is not limited to a flat plate, and may have a curved shape. As described above, the light control device may be curved.

In the display device etc. of the present disclosure, a light-shielding member that blocks external light from entering the optical device can be arranged in the area of the optical device where the light emitted from the image forming device is incident. By arranging a light-shielding member that blocks external light from entering the optical device in the area of the optical device where the light emitted from the image forming device is incident, even if the amount of incident external light changes due to the operation of the dimming device, external light does not enter the area of the optical device where the light emitted from the image forming device is incident in the first place, so that undesired stray light etc. is not generated and the image display quality in the display device is not deteriorated. It is preferable that the area of the optical device where the light emitted from the image forming device is incident is included in the projected image of the light-shielding member onto the optical device.

Alternatively, in the display device etc. of the present disclosure, a light-shielding member that blocks external light from entering the first deflection means can be arranged in the region of the first deflection means into which the light emitted from the image forming device is incident. By arranging a light-shielding member that blocks external light from entering the light guide plate in the region of the light guide plate into which the light emitted from the image forming device is incident, external light does not enter the region of the light guide plate into which the light emitted from the image forming device is incident, so that undesired stray light etc. is not generated and the image display quality of the display device is not deteriorated. It is preferable that the orthogonal projection image of the light-shielding member onto the light guide plate includes the region of the light guide plate into which the light emitted from the image forming device is incident.

The light-shielding member can be arranged on the opposite side of the optical device (light guide plate) to the side where the image forming device is arranged, and spaced apart from the optical device (light guide plate). In a display device having such a configuration, the light-shielding member may be made of, for example, an opaque plastic material, and such a light-shielding member may extend integrally from the housing of the image forming device, or may be attached to the housing of the image forming device, or may extend integrally from the frame, or may be attached to the frame. Alternatively, the light-shielding member may be arranged in a part of the optical device (light guide plate) opposite to the side where the image forming device is arranged, or the light-shielding member may be arranged in the light control device. The light-shielding member made of an opaque material may be formed, for example, on the surface of the optical device (light guide plate) based on a PVD method or a CVD method, or may be formed by a printing method, or a film, sheet, or foil made of an opaque material (plastic material, metal material, alloy material, etc.) may be attached. It is preferable that the projected image of the light blocking member onto the optical device (light guide plate) includes the projected image of the end of the light control device onto the optical device (light guide plate).

In the display device etc. of the present disclosure, as described above, the frame can be configured to include a front portion disposed in front of the viewer and two temple portions rotatably attached to both ends of the front portion via hinges. A tip portion of each temple portion is attached with an end portion (tip cell portion) as necessary. The image display device is attached to the frame, and specifically, for example, the image forming device may be attached to the temple portion, or a housing containing the image forming device may be attached to the front portion on the temple portion side. The image forming device (housing) may be attached by an appropriate method, for example, a method using screws. Furthermore, the front portion may be configured to include a nose pad portion. The front portion and the two temple portions may be configured as one unit. That is, when the display device etc. of the present disclosure is viewed as a whole, the frame generally has approximately the same structure and appearance as ordinary glasses or sunglasses. That is, when the display device etc. of the present disclosure is viewed as a whole, the assembly of the frame (including the rim portion) and the nose pad portion has approximately the same structure as ordinary glasses or sunglasses. The nose pads can also have a known configuration and structure. A speaker or headphone unit can be attached to the temples. The frame including the nose pads can be made of the same materials as those used to make regular eyeglasses or sunglasses, such as metals, alloys, plastics, or combinations of these.

In addition, in the display device etc. of the present disclosure, from the viewpoint of design or ease of wearing, it is desirable that the wiring (signal lines, power lines, etc.) from one or two image forming devices extend from the tip of the end piece to the outside through the temple part and the inside of the end piece, and are connected to the control device. Furthermore, each image forming device has a headphone part, and the wiring for the headphone part from each image forming device can be extended from the tip of the end piece to the headphone part through the temple part and the inside of the end piece. Examples of the headphone part include an inner-ear type headphone part and a canal type headphone part. More specifically, it is preferable that the wiring for the headphone part extends from the tip of the end piece to the headphone part so as to wrap around the back side of the auricle (ear shell). Also, it is possible to adopt a form in which a camera (imaging device) is attached to the center part of the front part. Specifically, the camera is composed of a solid-state imaging element made of, for example, a CCD or CMOS sensor, and a lens. The wiring from the camera may be connected to one of the image display devices (or image forming devices) via the front portion, for example, and may further be included in the wiring extending from the image display device (or image forming device).

In the display device of the present disclosure, a signal for displaying an image in the image display device (a signal for forming a virtual image in an optical device (e.g., a light guide plate)) can be received from the outside. In such a form, information and data related to the image to be displayed in the image display device are recorded, stored, and saved in, for example, a so-called cloud computer or server, and various information and data can be exchanged between the cloud computer or server and the display device by providing the display device with a communication means, for example, a mobile phone or smartphone, or by combining the display device with a communication means, and a signal based on the various information and data, i.e., a signal for displaying an image in the image display device (a signal for forming a virtual image in the optical device), can be received. Alternatively, a signal for displaying an image in the image display device (a signal for forming a virtual image in the optical device) can be stored in the display device. The image displayed in the image display device includes various information and data. Alternatively, the display device may be equipped with a camera (imaging device), and an image captured by the camera may be sent to a cloud computer or server via a communication means, various information and data corresponding to the image captured by the camera may be searched for in the cloud computer or server, the searched information and data may be sent to the display device via the communication means, and the searched information and data may be displayed as an image on the image display device.

When an image captured by a camera (imaging device) is sent to a cloud computer or a server via a communication means, the image captured by the camera may be displayed on an image display device and confirmed on an optical device (e.g., a light guide plate). Specifically, the outer edge of the spatial area captured by the camera may be displayed in a frame shape on the light control device. Alternatively, the light blocking rate of the area of the light control device corresponding to the spatial area captured by the camera may be higher than the light blocking rate of the area of the light control device corresponding to the outside of the spatial area captured by the camera. In such a form, the spatial area captured by the camera appears darker to the observer than the outside of the spatial area captured by the camera. Alternatively, the light blocking rate of the area of the light control device corresponding to the spatial area captured by the camera may be lower than the light blocking rate of the area of the light control device corresponding to the outside of the spatial area captured by the camera. In such a form, the spatial area captured by the camera appears brighter to the observer than the outside of the spatial area captured by the camera. This allows the observer to easily and reliably recognize where the camera is capturing the image of the outside.

The position of the area of the light control device corresponding to the spatial area captured by the camera (imaging device) can be calibrated. Specifically, by providing the display device with, for example, a mobile phone or smartphone, or by combining the display device with a mobile phone, smartphone, or personal computer, the spatial area captured by the camera can be displayed on the mobile phone, smartphone, or personal computer. If there is a difference between the spatial area displayed on the mobile phone, smartphone, or personal computer and the area of the light control device corresponding to the spatial area captured by the camera, a circuit for controlling the light blocking rate (light transmittance) of the light control device (which can also be substituted by a mobile phone, smartphone, or personal computer) can be used to move, rotate, or enlarge/reduce the area of the light control device corresponding to the spatial area captured by the camera, thereby eliminating the difference between the spatial area displayed on the mobile phone, smartphone, or personal computer and the area of the light control device corresponding to the spatial area captured by the camera.

The display device of the present disclosure, including the various modified examples described above, can be used, for example, to receive and display e-mails, display various information on various sites on the Internet, display various explanations and symbols, signs, marks, symbols, designs, etc. regarding the operation, manipulation, maintenance, disassembly, etc. of objects of observation such as various devices; display various explanations and symbols, signs, marks, symbols, designs, etc. regarding objects of observation such as people and objects; display videos and still images; display subtitles for movies, etc.; display explanatory text and closed captions regarding images synchronized with the images; various explanations regarding objects of observation in plays, kabuki, noh, kyogen, opera, concerts, ballet, various plays, amusement parks, art museums, tourist spots, recreational spots, tourist guides, etc. (various explanations during operation, manipulation, maintenance, disassembly, etc.), explanatory texts explaining the contents, progress, background, etc. of the objects, and can be used to display closed captions. In plays, Kabuki, Noh, Kyogen, opera, concerts, ballet, various plays, amusement parks, art museums, tourist spots, sightseeing spots, tourist guides, etc., texts as images related to the observed objects may be displayed on the display device at appropriate timing. Specifically, for example, in accordance with the progress of a movie or a play, an image signal is sent to the display device based on a predetermined schedule or time allocation, by an operator's operation or under the control of a computer, etc., and the image is displayed on the display device. In addition, various explanations related to the observed objects such as various devices, people, and objects are displayed on the display device by photographing (capturing) the observed objects such as various devices, people, and objects with a camera and analyzing the photographed (capturing) contents on the display device, and various explanations related to the observed objects such as various devices, people, and objects that have been created in advance can be displayed on the display device.

The image signal to the image forming device can include not only an image signal (e.g., character data) but also, for example, luminance data (luminance information), or chromaticity data (chromaticity information), or luminance data and chromaticity data related to the image to be displayed. The luminance data can be luminance data corresponding to the luminance of a predetermined area including an observation object viewed through an optical device (e.g., a light guide plate), and the chromaticity data can be chromaticity data corresponding to the chromaticity of a predetermined area including an observation object viewed through an optical device. In this way, by including luminance data related to an image, it is possible to control the luminance (brightness) of the image to be displayed, by including chromaticity data related to an image, it is possible to control the chromaticity (color) of the image to be displayed, and by including luminance data and chromaticity data related to an image, it is possible to control the luminance (brightness) and chromaticity (color) of the image to be displayed. When the luminance data corresponds to the luminance of a predetermined area including an observation object viewed through an optical device, the value of the luminance data can be set so that the luminance value of the image becomes higher (i.e., the image is displayed brighter) as the luminance value of the predetermined area including an observation object viewed through an optical device becomes higher. In addition, when the chromaticity data corresponds to the chromaticity of a predetermined area including an object viewed through an optical device, the chromaticity data value may be set so that the chromaticity of the predetermined area including the object viewed through an optical device and the chromaticity of the image to be displayed are approximately complementary colors. Complementary colors refer to a combination of colors that are located opposite each other on a color circle. They also refer to complementary colors such as green for red, purple for yellow, and orange for blue. They also refer to colors that cause a decrease in saturation when a certain color is mixed with another color in an appropriate ratio, such as white for light and black for objects, but the complementarity of the visual effect when juxtaposed is different from the complementarity when mixed. They are also called complementary colors, contrasting colors, and opposing colors. However, while complementary colors directly indicate the color opposite to them, complementary colors have a somewhat wider range of indications. A combination of complementary colors has a synergistic effect of enhancing each other's colors, which is called complementary color harmony.

For example, a head-mounted display (HMD) can be configured by the display device etc. of the present disclosure. This allows the display device to be made lighter and smaller, and the discomfort felt when wearing the display device can be significantly reduced, and furthermore, manufacturing costs can be reduced. Alternatively, the display device etc. of the present disclosure can be applied to a head-up display (HUD) provided in a vehicle or aircraft cockpit etc. Specifically, in a HUD in which a virtual image forming area in which a virtual image is formed based on light emitted from an image forming device is arranged on the windshield of a vehicle or aircraft cockpit etc., or in a HUD in which a combiner having a virtual image forming area in which a virtual image is formed based on light emitted from an image forming device is arranged on the windshield of a vehicle or aircraft cockpit etc., the virtual image forming area or combiner may be overlapped with at least a portion of a light control device. The display device etc. of the present disclosure can be used in a camera (imaging device) or as a stereoscopic display device. In this case, a polarizing plate or a polarizing film may be detachably attached to the optical device (e.g., a light guide plate) as necessary, or a polarizing plate or a polarizing film may be attached to the optical device. In addition, sunglasses may be formed using the light control device of the present disclosure, and the light control device of the present disclosure may be attached to a window (including windows in any field, including not only residential windows but also windows in any field, such as vehicular windows).

Example 1 relates to a display device (specifically, a head mounted display, HMD) of the present disclosure, specifically, to a display device of a first form having an optical device of a first structure (more specifically, an optical device of a 1-A structure) and an image forming device of a first configuration. FIG. 1A shows a schematic front view of the optical device and the dimming device (for the right eye) in the display device of Example 1, FIG. 1B shows a schematic cross-sectional view along the arrow B-B in FIG. 1A, FIG. 3A shows a schematic cross-sectional view of the dimming device similar to that along the arrow B-B in FIG. 1A, and FIG. 3B shows a schematic side view of the display device (mainly for the right eye) when the display device is viewed from the left eye side. In addition, conceptual diagrams of the image display device in the display device of Example 1 are shown in FIG. 4 and FIG. 5, a schematic view of the display device of Example 1 viewed from above is shown in FIG. 6, and a schematic view of the display device of Example 1 viewed from the front is shown in FIG. 7.

The display device of Example 1 or Examples 2 to 9 described below is
A frame 10 to be worn on the head of an observer 20; and
The image display devices 100, 200, 300, 400, and 500 are attached to a frame 10.

The image display devices 100, 200, 300, 400, and 500 in the first embodiment or in the second to ninth embodiments described below are
Image forming devices 111, 211,
An optical device 120, 320, 520 having a virtual image forming area where a virtual image is formed based on light emitted from an image forming device 111, 211; and
A light control device 700 that is disposed opposite at least the virtual image forming area and adjusts the amount of external light entering from the outside;
The display device in the embodiment is specifically a binocular type having two image display devices, but may be a monocular type having one image display device. Also, the image forming devices 111 and 211 display a monochromatic image, but the present invention is not limited to this.

Furthermore, in the image display devices 100, 200, 300, and 400 in the first embodiment or in the second to fourth and sixth to ninth embodiments described below,
an optical system (parallel light emission optical system) 112, 254 for converting light emitted from the image forming apparatus 111, 211 into parallel light;
The light beam collimated by the optical system 112, 254 enters the optical device 120, 320, is guided therein, and is then emitted.

The optical device 120 or 320 in the first embodiment or in the second to fourth and sixth to ninth embodiments described later has a first structure,
a light guide plate 121, 321 through which light incident from the image forming device 111, 211 propagates inside by total reflection and is then emitted toward the observer 20;
a first deflection unit 130, 330 for deflecting light incident on the light guide plate 121, 321 so that the light incident on the light guide plate 121, 321 is totally reflected inside the light guide plate 121, 321;
a second deflection unit 140, 340 for deflecting the light propagated by total reflection inside the light guide plate 121, 321 so as to emit the light from the light guide plate 121, 321;
The second deflection means 140, 340 constitute a virtual image forming region of the optical device. The second deflection means (virtual image forming region) 140, 340 is located within a projected image of the light control device 700. Furthermore, the second deflection means 140, 340 is covered by one of the substrates constituting the light control device 700. The optical devices 120, 320 are of a see-through type (semi-transmissive type).

Here, in the first embodiment, the first deflection means 130 and the second deflection means 140 are disposed inside the light guide plate 121. The first deflection means 130 reflects the light incident on the light guide plate 121, and the second deflection means 140 transmits and reflects the light propagated inside the light guide plate 121 by total reflection multiple times. That is, the first deflection means 130 functions as a reflecting mirror, and the second deflection means 140 functions as a semi-transmitting mirror. More specifically, the first deflection means 130 provided inside the light guide plate 121 is made of aluminum (Al) and is composed of a light reflecting film (a kind of mirror) that reflects the light incident on the light guide plate 121. On the other hand, the second deflection means 140 provided inside the light guide plate 121 is composed of a multi-layer laminated structure in which a large number of dielectric laminated films are laminated. The dielectric laminated film is composed of, for example, a TiO ₂ film as a high dielectric constant material and a SiO ₂ film as a low dielectric constant material. A multilayer laminated structure in which a large number of dielectric laminated films are laminated is disclosed in JP-A-2005-521099. In the drawing, six dielectric laminated films are illustrated, but the present invention is not limited to this. A thin piece made of the same material as the material constituting the light guide plate 121 is sandwiched between the dielectric laminated films. In the first deflection means 130, the parallel light incident on the light guide plate 121 is reflected (or diffracted) so that the parallel light incident on the light guide plate 121 is totally reflected inside the light guide plate 121. On the other hand, in the second deflection means 140, the parallel light propagated by total reflection inside the light guide plate 121 is reflected (or diffracted) multiple times, and is emitted from the light guide plate 121 in the form of parallel light toward the pupil 21 of the observer 20.

The first deflection means 130 may be formed by cutting out the portion 124 of the light guide plate 121 where the first deflection means 130 is to be provided, providing the light guide plate 121 with a slope on which the first deflection means 130 is to be formed, and then vacuum-depositing a light reflecting film on the slope, and then adhering the cut-out portion 124 of the light guide plate 121 to the first deflection means 130. The second deflection means 140 may be formed by producing a multi-layer laminated structure in which the same material as the material constituting the light guide plate 121 (e.g., glass) and a dielectric laminated film (which can be formed by, for example, a vacuum deposition method) are laminated in large numbers, cutting out the portion 125 of the light guide plate 121 where the second deflection means 140 is to be provided to form a slope, adhering the multi-layer laminated structure to the slope, and polishing or the like to adjust the outer shape. In this way, an optical device 120 in which the first deflection means 130 and the second deflection means 140 are provided inside the light guide plate 121 can be obtained.

Here, in Example 1 or Examples 2 to 4 and Examples 6 to 9 described later, the light guide plate 121, 321 made of optical glass or plastic material has two parallel surfaces (first surface 122, 322 and second surface 123, 323) extending parallel to the light propagation direction (X direction) by internal total reflection of the light guide plate 121, 321. The first surface 122, 322 and the second surface 123, 323 are opposed to each other. Then, parallel light is incident from the first surface 122, 322 corresponding to the light incident surface, propagates inside by total reflection, and then exits from the first surface 122, 322 corresponding to the light exit surface. However, this is not limited to this, and the light incident surface may be formed by the second surface 123, 323, and the light exit surface may be formed by the first surface 122, 322.

In the first embodiment or the third embodiment described later, the image forming device 111 constituting the image display device 100 is a first configuration image forming device, and has a plurality of pixels arranged in a two-dimensional matrix. Specifically, as shown in FIG. 4, the image forming device 111 is composed of a reflective spatial light modulator 150 and a light source 153 consisting of a light-emitting diode that emits white light. The entire image forming device 111 is housed in a housing 113 (shown by a dashed line in FIG. 4), and the housing 113 has an opening (not shown), through which light is emitted from the optical system (parallel light emission optical system, collimated optical system) 112. The reflective spatial light modulator 150 is composed of a liquid crystal display device (LCD) 151 consisting of LCOS as a light valve, and a polarizing beam splitter 152 that reflects a part of the light from the light source 153 and guides it to the liquid crystal display device 151, and also passes a part of the light reflected by the liquid crystal display device 151 and guides it to the optical system 112. The liquid crystal display device 151 includes a plurality of pixels (liquid crystal cells) (for example, 640×480 pixels) arranged in a two-dimensional matrix. The polarizing beam splitter 152 has a known configuration and structure. Unpolarized light emitted from the light source 153 impinges on the polarizing beam splitter 152. In the polarizing beam splitter 152, the P-polarized component passes through and is emitted outside the system. On the other hand, the S-polarized component is reflected by the polarizing beam splitter 152, enters the liquid crystal display device 151, is reflected inside the liquid crystal display device 151, and is emitted from the liquid crystal display device 151. Here, of the light emitted from the liquid crystal display device 151, the light emitted from the pixels displaying “white” contains a large amount of P-polarized component, and the light emitted from the pixels displaying “black” contains a large amount of S-polarized component. Therefore, of the light emitted from the liquid crystal display device 151 and impinging on the polarizing beam splitter 152, the P-polarized component passes through the polarizing beam splitter 152 and is guided to the optical system 112. On the other hand, the S-polarized light component is reflected by the polarizing beam splitter 152 and returned to the light source 153. The optical system 112 is composed of, for example, a convex lens, and an image forming device 111 (more specifically, a liquid crystal display device 151) is disposed at a focal length (position) of the optical system 112 in order to generate parallel light.

Alternatively, as shown in Fig. 5, the image forming device 111' is composed of an organic EL display device 150'. The image emitted from the organic EL display device 150' passes through a convex lens 112, becomes parallel light, and travels toward the light guide plate 121. The organic EL display device 150' has a plurality of pixels (organic EL elements) (e.g., 640 x 480) arranged in a two-dimensional matrix.

The frame 10 is composed of a front part 11 arranged in front of the viewer 20, two temple parts 13 rotatably attached to both ends of the front part 11 via hinges 12, and end pieces (also called tip parts, earmuffs, or ear pads) 14 attached to the tip of each temple part 13. A nose pad part 10' is also attached. That is, the assembly of the frame 10 and the nose pad part 10' basically has a structure substantially the same as that of normal glasses. Furthermore, each housing 113 is detachably attached to the temple part 13 by an attachment member 19. The frame 10 is made of metal or plastic. Note that each housing 113 may be attached to the temple part 13 by the attachment member 19 so that it cannot be detached. Also, although the state in which each housing 113 is attached to the inside of the temple part 13 is shown, it may be attached to the outside of the temple part 13.

Furthermore, the wiring (signal lines, power lines, etc.) 15 extending from the image forming device 111 extends from the tip of the end piece 14 to the outside through the temple part 13 and the inside of the end piece 14, and is connected to the control device (including the control unit 30) 18. Furthermore, each image forming device 111A, 111B is equipped with a headphone part 16, and the headphone part wiring 16' extending from each image forming device 111A, 111B extends from the tip of the end piece 14 to the headphone part 16 through the temple part 13 and the inside of the end piece 14. More specifically, the headphone part wiring 16' extends from the tip of the end piece 14 to the headphone part 16, wrapping around the back side of the auricle (auricle). With this configuration, the headphone part 16 and the headphone part wiring 16' do not give the impression of being arranged in a messy manner, and a neat display device can be obtained.

A camera 17, which is composed of a solid-state image sensor made of a CCD or CMOS sensor and a lens (not shown) as required, is attached to the center of the front part 11 by an appropriate mounting member (not shown). A signal from the camera 17 is sent to the control device 18 via wiring (not shown) extending from the camera 17.

Here, in the display device of Example 1 or Examples 2 to 9 described below, the light control device 700 is disposed in the front section 11. The optical devices 120, 320 are attached to the light control device 700. The front section 11 has a rim 11', and the light control device 700 is fitted into the rim 11'. From the observer's side, the optical devices 120, 320 and the light control device 700 are disposed in this order, but the light control device 700 and the optical devices 120, 320 may also be disposed in this order.

In Example 1 or Examples 2 to 9 described below, the optical devices 120, 320, and 520 overlap at least a portion of the light control device 700, which is a type of optical shutter. Specifically, in the examples shown in Figures 1A and 1B, the optical devices 120, 320, and 520 overlap a portion of the light control device 700. However, this is not limited to this, and the optical devices 120, 320, and 520 may overlap the light control device 700. In other words, the outer shape of the optical devices 120, 320, and 520 (more specifically, the light guide plates 121 and 321 that constitute the optical devices) and the light guide members 602, 612, and 622 may be the same as the outer shape of the light control device 700. FIG. 2A shows a schematic front view of the optical device and the light control device in such a form (i.e., a modified example of the display device of Example 1), and FIG. 2B shows a schematic cross-sectional view of the optical device and the light control device along the arrow B-B in FIG. 2A. In this modified example, a gap is provided between the light control device 700 and the light guide plate 121, 321, and the light control device 700 and the light guide plate 121, 321 are bonded together at the outer periphery by an adhesive 719D. The same can be applied to the embodiments described below. As a result, the outer edge of the light guide plate 121, 321 is hidden by the rim 11' described later, and the outer edge of the light guide plate 121, 321 is not visible. Here, the nose side of the observer 20 is referred to as the inside, and the ear side is referred to as the outside, and the area of the light control device 700 facing the virtual image forming area (second deflection means 140, 340) of the optical device is referred to as the virtual image forming area facing area 701.

In the display device of Example 1 or Examples 2 to 9 described later, the light control device 700 is
First electrode 712A,
a second electrode 712B facing the first electrode 712A;
A light-controlling layer 716 sandwiched between the first electrode 712A and the second electrode 712B; and
A control unit 30 that controls coloring and decoloring of the light-controlling layer 716;
Equipped with
The control unit 30 includes a secondary battery 31, a control circuit 32, and a capacitor (also called a capacitor, specifically, for example, an electric double layer capacitor, also called a supercapacitor or ultracapacitor) 33.
The control unit 30
(A) Charging of the capacitor 33 by the secondary battery 31, and
(B) When the light-controlling layer 716 is colored or decolored, a voltage is applied to the first electrode 712A and the second electrode 712B based on the discharge of the capacitor 33;
Furthermore, the control unit 30 controls
(C) application of a voltage to the first electrode 712A and the second electrode 712B based on the secondary battery 31 after a predetermined time (T ₀ ) has elapsed since the start of coloring or decoloring of the light-controlling layer 716;
The first electrode 712A and the second electrode 712B are connected to the control unit 30 via a connector (not shown). In the example shown in Fig. 11A, the capacitor 33 is one, but the capacitor 33 may be multiple capacitors 33 connected in parallel to ensure a desired capacitance.

In addition, after a predetermined time T ₀ ' has elapsed since the start of coloring of the light-adjusting layer 716, a voltage is applied to the first electrode 712A and the second electrode 712B based on the secondary battery 31, but after a specified time (coloring/specified time) T ₁ ' has elapsed, the application of voltage to the first electrode 712A and the second electrode 712B based on the secondary battery 31 may be stopped. Similarly, after a predetermined time T ₀ '' has elapsed since the start of decoloring of the light-adjusting layer 716, a voltage is applied to the first electrode 712A and the second electrode 712B based on the secondary battery 31, but after a specified time (decoloring/specified time) T ₁ '' has elapsed, the application of voltage to the first electrode 712A and the second electrode 712B based on the secondary battery 31 may be stopped. In some cases, application of a voltage based on the secondary battery 31 to the first electrode 712A and the second electrode 712B may be stopped after a predetermined time T ₀ ″ has elapsed since the start of decolorization of the light-adjusting layer 716. In addition, when the light-adjusting layer 716 is colored, the value of the voltage applied to the first electrode 712A and the second electrode 712B based on the discharge of the capacitor 33 and the value of the voltage applied to the first electrode 712A and the second electrode 712B based on the secondary battery 31 after a predetermined time T ₀ ′ has elapsed since the start of coloring of the light-adjusting layer 716 may be set to the same value, and the value of the light transmittance of the light-adjusting layer 716 is specified by this voltage. Predetermined times T ₀ , T ₀ 'T ₀ '', specified time (coloring, specified time) T ₁ ', specified time (decoloring, specified time) T ₁ The control unit 30 may store the time T 0 , T 0 'T 0 ", the specified time (coloring, specified time) T 1 ', and the specified time (erasing, specified time) T 1 " in advance. Alternatively, the control unit 30 may measure the voltage applied to the first electrode 712A and the second electrode 712B, and when the voltage applied to the first electrode 712A and the second electrode 712B reaches a predetermined voltage, the control unit 30 may determine that a predetermined time T ₀ , T ₀ 'T ₀ ", the specified time (coloring, specified time) T ₁ ', and the specified time (erasing, specified time) T ₁ " have been reached.

Furthermore, in the display device of Example 1 or Examples 2 to 9 described later,
When coloring the light control device, the control unit 30 applies a positive potential to one of the first electrode 712A and the second electrode 712B and applies a negative potential to the other of the first electrode 712A and the second electrode 712B;
When the dimmer is decolorized, the control unit 30 applies a voltage having a polarity opposite to that when the dimmer is colored to the first electrode 712A and the second electrode 712B. Specifically, when the dimmer is colored, for example, a voltage relatively higher than that applied to the first electrode 712A is applied to the second electrode 712B, and when the dimmer is decolorized, for example, a voltage relatively higher than that applied to the second electrode 712B is applied to the first electrode 712A.

In the display device of Example 1 or Examples 2 to 9 described below, the light control device 700 includes a first substrate 711A and a second substrate 711B facing the first substrate 711A, the first electrode 712A is provided on the facing surface of the first substrate 711A facing the second substrate 711B, and the second electrode 712B is provided on the facing surface of the second substrate 711A facing the first substrate 711A. In the illustrated example, the first substrate 711A faces the viewer 20, but the second substrate 711B may also face the viewer 20.

Furthermore, in the display device of Example 1 or Examples 2 to 9 described later, when the charge amount that gives the desired light transmittance to the light-adjusting layer 716 during coloring is _Q0 , the charge amount of the capacitor 33 after charging is _Q1 , and the charge amount of the capacitor 33 after a predetermined time _T0 has elapsed since the start of coloring or decoloring of the light-adjusting layer 716 is _Q2 ,
0.4<(Q ₁ -Q ₂ )/Q ₀
Preferably,
1.0≦(Q ₁ -Q ₂ )/Q ₀ ≦10.0
The control unit 30 controls the voltages applied to the capacitor 33 and the first and second electrodes 712A and 712B so as to satisfy _the following:
0.1 (seconds) ≦T ₀ ≦12 (seconds)
Preferably,
0.8 (seconds) ≦T ₀ ≦4 (seconds)
Specifically, but not limited to,
Q ₀ = 250 millifarads (when the dimming area is 2500 ^mm2 )
Q ₁ = 500 millifarads and Q ₂ = 250 millifarads can be given.
Examples include T ₀ =4 seconds, T ₀ ' =4 seconds, and T ₀ '' =2 seconds.

Furthermore, when the effective area of the light control layer 716 is A (mm ² ) and the capacitance of the capacitor 33 is C (farads),
C/A>1×10 ^-6 [0.000001] (F/mm ² )
Specifically,
A = 2500 ^mm2
C=250 millifarads.

When the light control device is colored or decolored, a constant voltage is applied to the first electrode 712A and the second electrode 712B from the capacitor 33 and/or the secondary battery 31 via a voltage control circuit (regulator) 50. The output voltage from the secondary battery 31 may be higher than the voltage at which damage does not occur to the material that constitutes the light control layer 716. By using the voltage control circuit 50, problems such as damage to the material that constitutes the light control layer 716 can be avoided, but in some cases the voltage control circuit 50 is not necessary.

Furthermore, in the display device of Example 1 or Examples 2 to 9 described below, when a voltage is applied to the first electrode 712A and the second electrode 712B, a current flows through the dimming layer 716.

The light control device 700 is a type of light shutter that utilizes the color change of a substance caused by the oxidation-reduction reaction of an electrochromic material. Specifically, the light control layer 716 includes an electrochromic material. More specifically, the light control layer 716 has a laminated structure of a _WO3 layer (reduction coloring layer) _{713/Ta2O5 layer} (electrolyte layer) 714/ _{IrXSn1 -XO} layer (oxidation coloring layer) 715 from the first electrode side. The _WO3 layer 713 develops color by reduction. _{The Ta2O5} layer 714 constitutes a solid electrolyte, and the _{IrXSn1 -XO} layer 715 develops color by oxidation. A protective layer 719A made of a SiN layer, a _SiO2 layer, an _{Al2O3 layer} , a _TiO2 layer, or a laminated film of these is formed between the first electrode 712A and the first substrate 711A. By forming the protective layer 719A, the light control device can be provided with ion blocking properties that prevent ions from passing back and forth, waterproof properties, moisture resistance, and scratch resistance. A base layer 719B is formed between the second substrate 711B and the second electrode 712B. In addition, the first substrate 711A and the second substrate 711B are sealed at the outer edge with a sealant 719C made of ultraviolet curing resin such as ultraviolet curing epoxy resin, epoxy resin cured by ultraviolet light and heat, or thermosetting resin. The first substrate 711A and the second substrate 711B are made of PEN (polyethylene naphthalate) resin, PES (polyethersulfone) resin, COP (cycloolefin polymer), colorless and transparent polyimide resin, TAC film, or highly transparent self-adhesive acrylic film, but are not limited to these. The first electrode 712A and the second electrode 712B made of a transparent conductive material such as ITO or IZO are not patterned and are so-called solid electrodes. The light control device 700 itself can be fabricated by a known method.

In the _{IrxSn1 -xO} layer 715, Ir and _H2O react to form iridium hydroxide Ir(OH) _n . When a negative potential is applied to the first electrode 712A and a positive potential is applied to the second electrode 712B, protons H ⁺ move from the _{IrxSn1 -xO} layer 715 to _{the Ta2O5} layer 714 and electrons are released to the second electrode 712B, causing the next oxidation reaction to proceed and causing the _{IrxSn1 -xO} layer 715 to become colored.
Ir(OH) _n → IrO _X (OH) _nX (coloring) + X・H ⁺ + X・e ^-

Meanwhile, protons H ⁺ in the Ta ₂ O ₅ layer 714 move into the WO ₃ layer 713, electrons are injected from the first electrode 712A into the WO ₃ layer 713, and the next reduction reaction proceeds in the WO ₃ layer 713, causing the WO ₃ layer 713 to become colored.
WO ₃ + X・H ⁺ + X・e ^- → H _X WO ₃ (coloring)

Conversely, when a positive potential is applied to the first electrode 712A and a negative potential is applied to the second electrode 712B, a reduction reaction proceeds in the opposite direction to the above in the _{IrxSn1 -xO layer} 715, causing decolorization, and an oxidation reaction proceeds in the opposite direction to the above in the _WO3 layer 713, causing decolorization. The _Ta2O5 layer 714 contains _H2O , which is ionized by applying a voltage to the first electrode 712A and the second electrode 712B, and contains protons H ⁺ and ^OH- ions, which contribute to the coloring reaction and decolorization reaction.

Figure 8 shows an example of the relationship between the voltage (ΔV) applied between the first electrode 712A and the second electrode 712B and the light transmittance. In the example shown, the light transmittance decreases as the value ΔV of the voltage applied between the first electrode 712A and the second electrode 712B increases, but when ΔV exceeds 1 volt, the rate at which the light transmittance decreases becomes smaller. It was also possible to recognize that the light-control layer 716 began to color when ΔV was 0.2 volts.

9 shows a graph showing the change in current flowing through the dimming layer 716 in a state after the start of coloring when a constant voltage (ΔV) is applied between the first electrode 712A and the second electrode 712B constituting the dimming device 700 as shown in the upper part of FIG. 9, and a graph showing the change in light transmittance is shown in the lower part of FIG. 9. Also, in a state after the start of decoloring when a constant voltage (-ΔV) is applied between the first electrode 712A and the second electrode 712B constituting the dimming device 700 as shown in the upper part of FIG. 10, a graph showing the change in current flowing through the dimming layer 716 is shown in the middle part of FIG. 10, and a graph showing the change in light transmittance is shown in the lower part of FIG. 10. Here, the case of Example 1 in which the current flowing through the dimming layer 716 is not limited is indicated by "A", and the case in which the current flowing through the dimming layer 716 is limited to 20 milliamperes is indicated as Comparative Example 1 by "B". In the case of Example 1 in which the current flowing through the light-controlling layer 716 is not limited, a voltage is applied to the first electrode 712A and the second electrode 712B based on the discharge of the capacitor 33. After the voltage is applied to the first electrode 712A and the second electrode 712B based on the discharge of the capacitor 33, a voltage is applied from the secondary battery 31 to the first electrode 712A and the second electrode 712B.

In the case of Comparative Example 1, in which the current flowing through the light-adjusting layer 716 is limited to 20 milliamperes, it takes a long time to color and erase. On the other hand, in the case of Example 1, in which the current flowing through the light-adjusting layer 716 is not limited, a voltage is applied to the first electrode 712A and the second electrode 712B based on the discharge of the capacitor 33, so it can be seen that the time required for coloring and erasing is significantly shortened.

By the way, when adjusting the light by the light control device 700, it is necessary to reverse the polarity of the voltage applied to the first electrode 712A and the second electrode 712B for coloring and decoloring. Also, in order to obtain the target light transmittance, it is necessary to change (control or set) the voltage applied between the first electrode 712A and the second electrode 712B. Moreover, in order to quickly change the light transmittance, it is necessary to pass a large current between the first electrode 712A and the second electrode 712B at the start of coloring or decoloring. In addition, when a large current flows between the first electrode 712A and the second electrode 712B, for example, the voltage supplied to the image forming device must not temporarily drop, causing the operation of the entire display device to become unstable.

11A and 13 show circuit diagrams of the control unit 30. Note that Fig. 13 is a circuit diagram of a secondary battery control unit 32A which is a part of the control circuit 32 constituting the control unit 30. The control circuit 32
A current limiting circuit that limits the current when the secondary battery 31 is discharged; and
A voltage control circuit (regulator) 50 that controls the voltage applied from the capacitor 33 and the secondary battery to the first electrode 712A and the second electrode 712B;
Here, the current limiting circuit is included in the secondary battery control unit 32A. In the illustrated example, the capacitor 33 is one, but the secondary battery control unit 32A may be configured with a plurality of capacitors 33 connected in parallel to ensure a desired capacitance.

The control circuit 32 includes a first switch section 41 and a second switch section 42. In the control section 30, the positive terminal 1031 and the negative terminal 1032 of the secondary battery control section 32A are connected to the first switch section 41 constituting the control circuit 32, and both ends of the capacitor 33 are also connected to the first switch section 41. Furthermore, the dimmer 700 is also connected to the first switch section 41 via the second switch section 42. The polarity of the voltage applied to the first electrode 712A and the second electrode 712B can be switched by switching the second switch section 42.

The positive terminal 1031 and the negative terminal 1032 of the secondary battery control unit 32A are also connected to an image forming device or the like that constitutes the display device, and the image forming device or the like is driven by the secondary battery 31. Here, the secondary battery 31 is composed of a cell (battery pack) 1001 shown in FIG. 13.

In the light control device of the embodiment, the capacitor 33 is charged by the secondary battery 31 at a limited current value except when the capacitor 33 is discharging. Furthermore, when the coloring or decoloring of the light control device 700 starts, a voltage is applied to the first electrode 712A and the second electrode 712B based on the discharge of the capacitor 33. Furthermore, when the capacitor 33 discharges and the voltage applied to the first electrode 712A and the second electrode 712B decreases, that is, after a predetermined time (T ₀ ) has elapsed since the coloring or decoloring of the light control device 700 starts, a voltage is applied to the first electrode and the second electrode based on the secondary battery 31. The flow of the above-mentioned operation of the light control device is shown in FIG. 31.

Specifically, when the capacitor 33 is charged by the secondary battery 31 at a limited current value in the first switch section 41, the switch section _SW2 is in a connected state and the switch sections _SW1 and _SW3 are in a disconnected state. When the charging of the capacitor 33 is completed, the switch section _SW2 is in a disconnected state. Furthermore, when the coloring or decoloring of the light control device 700 starts, the switch sections _SW1 and _SW2 are in a disconnected state and the switch section _SW3 is in a connected state, and the capacitor 33 is discharged. Note that, when the capacitor 33 is discharged, if the reverse flow of current from the capacitor 33 to the secondary battery control section 32A is prevented by the secondary battery control section 32A, the switch section _SW1 may be in a connected state. Furthermore, after a predetermined time ( _T0 ) has elapsed from the start of coloring or decoloring of the light control device 700, the switch section _SW1 is in a connected state and the switch sections _SW2 and _SW3 are in a disconnected state.

As shown in FIG. 13, the secondary battery control unit 32A, which is part of the control circuit 32 constituting the control unit 30, includes an exterior member (not shown), a switch unit 1021, a current detection resistor 1014, a temperature detection element 1016, and a controller 1010. The switch unit 1021 includes a charge control switch 1022 and a discharge control switch 1024. The control unit also includes a positive terminal 1031 and a negative terminal 1032, and during charging, the positive terminal 1031 and the negative terminal 1032 are connected to the positive terminal and the negative terminal of the charger, respectively, for charging. During use of the display device, the positive terminal 1031 and the negative terminal 1032 are connected to the positive terminal and the negative terminal of the display device, respectively, for discharging.

The cell 1001 (secondary battery 31) is composed of multiple lithium ion batteries 1002 connected in series and/or parallel. Note that FIG. 13 shows a case where six lithium ion batteries 1002 are connected in 2 parallel 3 series (2P3S), but any other connection method such as p parallel q series (where p and q are integers) is also acceptable. That is, the connection format of the lithium ion batteries may be in series, in parallel, or a mixture of both.

The switch unit 1021 includes a charge control switch 1022 and a diode 1023, as well as a discharge control switch 1024 and a diode 1025, and is controlled by the controller 1010. The diode 1023 has a reverse polarity with respect to the charge current flowing from the positive terminal 1031 to the cell 1001, and a forward polarity with respect to the discharge current flowing from the negative terminal 1032 to the cell 1001. The diode 1025 has a forward polarity with respect to the charge current and a reverse polarity with respect to the discharge current. In this example, the switch unit is provided on the positive (+) side, but it may be provided on the negative (-) side. The charge control switch 1022 is opened when the battery voltage reaches the overcharge detection voltage, or when the capacitor 33 starts discharging, and is controlled by the controller 1010 so that the charge current (or reverse current) does not flow in the current path of the cell 1001. After the charge control switch 1022 is opened, only discharging is possible through the diode 1023. Also, when a large current flows during charging or when the capacitor 33 starts discharging, the controller 1010 controls the switch 1022 to be opened and to cut off the charging current (or reverse current) flowing through the current path of the cell 1001. The discharge control switch 1024 is opened when the battery voltage reaches the over-discharge detection voltage, and is controlled by the controller 1010 so that no discharging current flows through the current path of the cell 1001. After the discharge control switch 1024 is opened, only charging is possible through the diode 1025. Also, when a large current flows during discharging, the controller 1010 controls the switch 1022 to be opened and to cut off the discharging current flowing through the current path of the cell 1001. In this way, the secondary battery control unit 32A also functions as a current limiting circuit that limits the current during discharging of the secondary battery 31.

The temperature detection element 1016 is, for example, a thermistor and is provided near the cell 1001. The temperature measurement unit 1015 measures the temperature of the cell 1001 using the temperature detection element 1016 and sends the measurement result to the controller 1010. The voltage measurement unit 1012 measures the voltage of the cell 1001 and the voltage of each lithium ion battery 1002 that constitutes the cell 1001, A/D converts the measurement result, and sends it to the controller 1010. The current measurement unit 1013 measures the current using a current detection resistor 1014 and sends the measurement result to the controller 1010.

The switch control unit 1020 controls the charge control switch 1022 and the discharge control switch 1024 of the switch unit 1021 based on the voltage and current sent from the voltage measurement unit 1012 and the current measurement unit 1013. When the voltage of any of the lithium ion batteries 1002 falls below the overcharge detection voltage or the overdischarge detection voltage, or when a large current flows suddenly, the switch control unit 1020 sends a control signal to the switch unit 1021 to prevent overcharging, overdischarging, and overcurrent charging and discharging. The charge control switch 1022 and the discharge control switch 1024 can be composed of a semiconductor switch such as a MOSFET. In this case, the diodes 1023 and 1025 are composed of the parasitic diode of the MOSFET. When a p-channel FET is used as the MOSFET, the switch control unit 1020 supplies a control signal DO and a control signal CO to the gates of the charge control switch 1022 and the discharge control switch 1024, respectively. The charge control switch 1022 and the discharge control switch 1024 are made conductive by a gate potential that is lower than the source potential by a predetermined value or more. That is, in normal charging and discharging operations, the control signals CO and DO are set to low level, and the charge control switch 1022 and the discharge control switch 1024 are made conductive. Then, for example, in the event of overcharging or overdischarging, the control signals CO and DO are set to high level, and the charge control switch 1022 and the discharge control switch 1024 are made open.

The memory 1011 is, for example, an erasable programmable read only memory (EPROM) which is a non-volatile memory. The memory 1011 prestores values calculated by the controller 1010 and the internal resistance value of each lithium ion battery 1002 in the initial state measured during the manufacturing process, and can be rewritten as necessary. In addition, by storing the full charge capacity of the lithium ion battery 1002, the remaining capacity can be calculated together with the controller 1010.

The temperature measurement unit 1015 measures the temperature using a temperature detection element 1016, performs charge/discharge control in the event of abnormal heat generation, and also performs corrections in the calculation of remaining capacity.

As described above, the switching of the first switch unit 41 and the second switch unit 42 can be performed based on the measurement results of the illuminance sensor (or the second illuminance sensor), or can be performed by operation by the observer 20, or can be performed in synchronization with the start or end of image formation in the image forming device.

As shown in FIG. 11B, in some cases, the voltage control circuit (regulator) 50 may be omitted. Also, as shown in FIG. 12, the switch units 41A and 41B may be provided, and two capacitors 33A and 33B may be provided, and a higher voltage may be applied to the second electrode 712B than the first electrode 712A by discharging the capacitor 33A, thereby coloring the light control device 700, and a higher voltage may be applied to the first electrode 712A than the second electrode 712B by discharging the capacitor 33B, thereby decoloring the light control device 700. In these cases, the secondary battery control unit 32A may include a voltage control circuit that controls the value of the voltage applied to the first electrode 712A and the second electrode 712B to control the light transmittance of the light control layer 716.

Fig. 14A shows a charging circuit 60 for charging the capacitor 33. This charging circuit 60 includes a comparator 61, a constant voltage IC with a current limiting function (hereinafter referred to as a "constant voltage IC 62"), and a voltage control circuit (regulator) 50. Fig. 14B shows the change in potential at each part. In this charging circuit 60, the terminal voltage (V _ELDC ) of the constant voltage IC 62 is applied to the inverting terminal of the comparator 61 via a resistor R4. The reference voltage V _REF and the hysteresis voltages V ₁ and V ₂ are set by resistors R1, R2, and R3. When the terminal voltage (V _ELDC ) falls below the voltage V ₂ , the enable terminal EN of the constant voltage IC 62 transitions to a "high" state, the constant voltage IC 62 turns on, the limited current I _CHG flows, and the capacitor 33 is charged. When the terminal voltage (V _ELDC ) reaches voltage V ₁ (i.e., the maximum operating voltage of capacitor 33), the enable terminal EN of the constant voltage IC 62 transitions to the "low" state, the constant voltage IC 62 turns off, and charging ends. Such a charging circuit 60 may be provided upstream of the capacitor 33 in the circuits shown in Figures 11A, 11B, and 12.

Figures 15A and 15B show light transmittance/polarity control circuits 70A and 70B for controlling the light transmittance and changing the polarity of the voltage applied to the first electrode 712A and the second electrode 712B. The light transmittance/polarity control circuits 70A and 70B control the voltage applied to the first electrode 712A and the second electrode 712B depending on the level of light transmittance, and control the polarity of the voltage applied to the first electrode 712A and the second electrode 712B according to instructions for coloring/decoloring. The second switch section 42 shown in Figures 11A and 11B is replaced by the light transmittance/polarity control circuits 70A and 70B.

The light transmittance/polarity control circuit 70A shown in FIG. 15A is composed of two operational amplifiers 71A and 71B. A potential (V _DD /x) between V _DD and the ground potential is input to the non-inverting input of the operational amplifiers 71A and 71B. The value of "x" is, for example, an integer equal to or greater than 2. A potential V _IN is input to the inverting input of the operational amplifier 71B. The light transmittance of the dimming device 700 is specified (set) by the potential V _IN . The output of the operational amplifier 71B is connected to the first electrode 712A of the dimming device 700 and is also connected to the inverting input of the operational amplifier 71A. The output of the operational amplifier 71A is connected to the second electrode 712B of the dimming device 700. The positive power supplies of the two operational amplifiers 71A and 71B are connected to a voltage control circuit (regulator) 50, and the voltage control circuit 50 is connected to a capacitor 33. In addition, the negative power supplies of the two operational amplifiers 71A and 71B are grounded.

Alternatively, the light transmittance/polarity control circuit 70B is shown in FIG. 15B. The light transmittance/polarity control circuit 70B has two constant voltage circuits that output a positive voltage with respect to the ground, and controls the coloring/decoloring of the dimmer 700 (control of the polarity of the applied voltage) and the light transmittance by increasing or decreasing the output voltage V _{out-2 of} one constant voltage circuit based on an output voltage control signal relative to the fixed output voltage V out-1 of the other constant voltage circuit. When (V out _-2 - V _out-1 )>0, the dimmer 700 is in a colored state, and when (V _out-2 - V _out-1 )<0, the dimmer 700 is in a decolored state. Also, the light transmittance is determined depending on the value of |V _out-2 - V _out-1 |.

A circuit diagram of another drive circuit of the dimmer 700 is shown in FIG. 16, and the operation of the drive circuit shown in FIG. 16 is explained in FIG. 17. The DC voltage of the output of the D/A converter 81 changes according to the light transmittance setting signal of the dimmer 700. When this DC voltage is high, the light transmittance of the dimmer 700 decreases (coloring), and when the DC voltage is low, the light transmittance of the dimmer 700 increases (discoloration). In addition, the edge of the DC voltage change is extracted by the differential circuit 82. Then, after several seconds have passed from the edge of this DC voltage change, the discharge current from the capacitor 33 begins to flow into the dimmer layer 716. In addition, since the edge of the DC voltage change is bipolar, it is summarized into one-way polarity by the absolute value circuit 83. Then, a square wave is generated by the comparator circuit 84, and the level shift circuit 85 corrects it to a waveform based on ground. Furthermore, a delay is generated by the mono-multi delay IC 86 to set the low level period of the square wave (the disable period of the constant voltage IC 62) to a section in which discharge current from the capacitor 33 should be avoided.

In some cases, the first electrode and/or the second electrode may be divided into multiple blocks, and the light blocking rate in each block may be controlled to control the light blocking rate for each region of the dimmer. Alternatively, the first electrode or the second electrode may be a strip-shaped electrode or a mesh-shaped electrode, or a strip-shaped auxiliary electrode or a mesh-shaped auxiliary electrode may be formed on the first electrode or the second electrode, so that the light blocking rate in multiple regions of the dimmer can be controlled independently. In some cases, the dimmer may be configured as a liquid crystal display device driven based on, for example, an active matrix system or a simple matrix system, and the light blocking rate of the dimmer may be controlled.

When the light blocking rate in the light control device 700 is controlled based on, for example, a simple matrix method, a schematic plan view of the light control device 700 is shown in FIG.
The first electrode 712A is composed of a plurality of strip-shaped first electrode segments 712A′ extending in a first direction,
The second electrode 712B is composed of a plurality of strip-shaped second electrode segments 712B′ extending in a second direction different from the first direction,
The light blocking rate of a portion of the dimmer corresponding to an overlapping region (the minimum unit region in which the light blocking rate of the dimmer changes) between the first electrode segment 712A' and the second electrode segment 712B' is controlled based on the control of the voltage applied to the first electrode segment 712A' and the second electrode segment 712B'. The first direction and the second direction are perpendicular to each other, and specifically, the first direction extends in the horizontal direction (X direction), and the second direction extends in the vertical direction (Y direction).

The light control device 700 was estimated to achieve a light transmittance of 72% to 7%. The area of the region of the light control device 700 that contributes to light control (hereinafter referred to as the "light control region") was set to, for example, 1120 ^mm2 (=56 mm x 20 mm). The amount of charge required for coloring and decoloring of such a light control device 700 was measured to be 224 millicoulombs. From this, the amount of charge per unit area of the light control region of the light control device 700 is 0.2 millicoulombs/ ^mm2 (=224/1120).

In a light control device with a dimming region of 1120 ^mm2 , it was experimentally confirmed that, when no restriction is imposed on the current flowing between the first electrode 712A and the second electrode 712B, it takes 3.6 seconds for the current flowing between the first electrode 712A and the second electrode 712B to reach 20 milliamperes, for example, during coloring, and 1.8 seconds during decoloring. Furthermore, from the data on the change in current over time, it was found that, at this time, 157 millicoulombs, which corresponds to 70% of the charge of 224 millicoulombs at which coloring is completed, are injected into the light control device during coloring, and 220 millicoulombs, which corresponds to 98% of the charge of 224 millicoulombs at which decoloring is completed, are injected into the light control device during decoloring. From this, when a current limit of 20 milliamperes is imposed on secondary battery 31 during coloring/erasing, in order to supply the amount of charge required for coloring/erasing from capacitor 33 without impairing the operating speed, the amount of charge change ( _Q1 - _Q2 ) before and after discharging capacitor 33 with respect to the amount of charge _Q0 required for coloring/erasing must be _Q0 x 0.98 or more.

This charge amount is determined by the capacitance C of the capacitor 33 and the potential difference (V ₁ -V ₂ ) before and after discharge. In practice, the voltage of the secondary battery 31 that charges the capacitor 33 is set to a commercially available rated voltage of 3.7 volts. This voltage corresponds to the voltage V ₁ at the start of discharge of the capacitor 33. If the voltage V ₂ immediately after a sufficient charge is applied to the light-adjusting layer 716, that is, when a current equal to or less than the limit current starts to flow, is set to 1.5 volts, the voltage control circuit can have an even simpler circuit configuration. In this case, the capacitance C required for the capacitor 33 to cover a charge amount of 220 millicoulombs, which corresponds to 98% of the charge amount of 224 millicoulombs at which decolorization is completed, with a potential difference of 2.2 volts (3.7 volts - 1.5 volts) is:
C=Q/ΔV=220[mC]/2.2[V]=100[mF]
In fact, it is possible to obtain a discharge current from such a capacitor 33 that is about the same as that of a secondary battery 31 without current limitation, and the average current during discharge of the capacitor 33 during decolorization was about 124 millicoulombs/second (=124 milliamperes).

The discharge time T _Discharge of the capacitor 33 is generally expressed as follows, where P is the output of the capacitor 33:
T _Discahrge = (1/2) x C x (V ₁ ² - V ₂ ² )/P
(See ELMA's technical documents https://www.elna.co.jp/capacitor/double_layer/pdf/calculation.pdf.) Here, output P = (output current) x (output voltage). If the output current is approximated by the average current during discharge of 124 millicoulombs/second (= 124 milliamperes), and the output voltage is approximated by the average voltage {( _V1 + _V2 )/2 = 2.6 volts}, then
T _Discahrge = (1/2) x 100 [mC/V] x (3.7 ² -1.5 ² ) [V ² ]
/(124×2.6) [mC・V/sec]
≒ 1.8 seconds
It can be seen that the same operating speed can be obtained by driving the dimmer 700 using the capacitor 33 as when the secondary battery is discharged without current limitation. Although the discharge voltage of the capacitor 33 decreases as the capacitor 33 is discharged, a constant voltage is applied to the dimmer 700 by the voltage control circuit.

Incidentally, the actual operating speed of the light control device and the amount of charge required for the capacitor 33 vary depending on the area of the light control area in the light control device, the required range of light transmittance, the limiting current, the rated voltage of the secondary battery 31, and the voltage applied between the electrodes of the light control device. The example described above is an example in which coloring/decoloring is performed in a sunglass-sized light control device (area contributing to light control: 1120 mm ² ) with a light transmittance range of 72% to 8%, and the voltage V ₂ between the electrodes is 1.5 volts. In this case, the current due to the discharge of the capacitor 33 is expected to be a maximum of about 300 milliamperes.

The charge per unit area of 0.2 millicoulombs/ ^mm2 is the charge required for coloring and decoloring a light control device that has been experimentally confirmed, but in reality, a larger charge is required to expand the light transmittance range. Since the charge of the capacitor 33 also varies depending on the voltage, the capacitance per unit area C [F/ ^mm2 ] that will likely cover the required charge even at a lower voltage (0.2 volts) is:
C=Q[mC/ ^mm2 ]/V[V]
=0.2×10 ^-3 /0.2
=0.001 [F/mm ² ]
Taking into account the narrower light transmittance range and voltage,
C/A>1×10 ^-6 [F/mm ² ]
It is set as follows.

The operating time of capacitor 33 corresponding to a limit current of 20 milliamps (3.6 seconds when coloring, 1.8 seconds when decoloring) is also an operating time that has been experimentally confirmed. However, as the area of the dimming area in a dimming device increases, the operating time becomes longer (slower) regardless of the operating circuit. Therefore, the relationship between the area of the dimming area and the operating time should be determined taking into account practical value and the actual operating speed.

As described above, since the display device of Example 1 is provided with a dimming device, it is possible to provide a high contrast to the virtual image observed by the observer. Moreover, the coloring/decoloring of the dimming device can be performed quickly by applying a voltage to the first electrode and the second electrode based on the discharge of the capacitor, and a small secondary battery can be used. Furthermore, since the capacitor is charged by the secondary battery, it is possible to simplify the configuration of the entire control unit and to reduce the weight and size of the display device. In addition, since the control unit applies a voltage to the first electrode and the second electrode based on the secondary battery after a predetermined time (T ₀ ) has elapsed since the start of coloring or decoloring of the dimming device, it is possible to stabilize the value of the light transmittance of the dimming device.

As described above, in the secondary battery control unit, the controller controls to suppress the flow of a large current from the secondary battery control unit. Therefore, when using such a secondary battery control unit, it is difficult to pass a large current between the first electrode and the second electrode in order to quickly change the light transmittance of the dimming layer. However, in Example 1, the dimming device is equipped with a capacitor, and the coloring and decoloring of the dimming device can be quickly performed by applying a voltage to the first electrode and the second electrode based on the discharge of the capacitor. Moreover, if a predetermined time has passed since the start of coloring of the dimming layer, the coloring state of the dimming layer can be stabilized by applying a voltage to the first electrode and the second electrode based on the secondary battery.

Example 2 is a modification of Example 1, and relates to an optical device of the 1-A structure and an image forming device of the second configuration. As shown in Fig. 18, which is a conceptual diagram of an image display device 200 in a display device (head mounted display) of Example 2, in Example 2, an image forming device 211 (211A, 211B) is composed of an image forming device of the second configuration. That is, it includes a light source 251 and a scanning means 253 that scans the parallel light emitted from the light source 251. More specifically, the image forming device 211 includes:
Light source 251,
a collimating optical system 252 that converts the light emitted from the light source 251 into parallel light;
a scanning means 253 for scanning the parallel light emitted from the collimating optical system 252; and
a relay optical system 254 that relays and emits the parallel light scanned by the scanning means 253;
The image forming device 211 is entirely housed in a housing 213 (indicated by a dashed line in FIG. 18), and the housing 213 has an opening (not shown) through which light is emitted from the relay optical system 254. Each housing 213 is detachably attached to the temple portion 13 by an attachment member 19.

The light source 251 is composed of a light-emitting element that emits white light. The light emitted from the light source 251 is incident on a collimating optical system 252 that has a positive optical power overall, and is emitted as parallel light. This parallel light is reflected by a total reflection mirror 256, and horizontal and vertical scanning is performed by a scanning means 253 consisting of a MEMS that can rotate a micromirror in two dimensions and scan the incident parallel light two-dimensionally, and a kind of two-dimensional image is generated, and virtual pixels (the number of pixels can be the same as in Example 1, for example) are generated. The light from the virtual pixel passes through a relay optical system (parallel light emission optical system) 254 composed of a well-known relay optical system, and the parallel light beam is incident on the optical device 120.

The optical device 120, into which the light beam collimated by the relay optical system 254 is incident, guided, and emitted, has the same configuration and structure as the optical device described in Example 1, so a detailed description thereof will be omitted. Also, as described above, the display device of Example 2 has substantially the same configuration and structure as the display device of Example 1, except that the image forming device 211 is different, so a detailed description thereof will be omitted.

Example 3 is also a modification of Example 1, but relates to an optical device of the 1-B structure and an image forming device of the first configuration. FIG. 19 shows a conceptual diagram of an image display device 300 in a display device (head-mounted display) of Example 3. FIG. 20 shows a schematic cross-sectional view of an enlarged portion of a reflective volume hologram diffraction grating. In Example 3, the image forming device 111' is composed of an organic EL display device 150', as in Example 1. The image forming device 111' is composed of an organic EL display device 150', as in Example 1. The image forming device may be composed of the image forming device 111 in Example 1 shown in FIG. 4. The optical device 320 has the same basic configuration and structure as the optical device 120 of Example 1, except that the configuration and structure of the first deflection means and the second deflection means are different.

In the third embodiment, the first deflection means and the second deflection means are disposed on the surface of the light guide plate 321 (specifically, the second surface 323 of the light guide plate 321). The first deflection means diffracts the light incident on the light guide plate 321, and the second deflection means diffracts the light propagated inside the light guide plate 321 by total reflection. Here, the first deflection means and the second deflection means are made of a diffraction grating element, specifically a reflective diffraction grating element, more specifically a reflective volume hologram diffraction grating. In the following description, the first deflection means made of a reflective volume hologram diffraction grating is referred to as the "first diffraction grating member 330" for convenience, and the second deflection means made of a reflective volume hologram diffraction grating is referred to as the "second diffraction grating member 340" for convenience.

In Example 3 or Example 4 described later, the first diffraction grating member 330 and the second diffraction grating member 340 are configured to have one diffraction grating layer laminated. Each diffraction grating layer made of a photopolymer material has interference fringes corresponding to one type of wavelength band (or wavelength) formed therein, and is manufactured by a conventional method. The pitch of the interference fringes formed in the diffraction grating layer (diffraction grating element, diffraction grating member) is constant, and the interference fringes are linear and extend in the Y direction. The axes of the first diffraction grating member 330 and the second diffraction grating member 340 extend in the X direction, and the normals extend in the Z direction.

Figure 20 shows an enlarged schematic partial cross-sectional view of a reflection type volume hologram diffraction grating. In the reflection type volume hologram diffraction grating, interference fringes having a slant angle (slant angle) φ are formed. Here, the slant angle φ refers to the angle between the surface of the reflection type volume hologram diffraction grating and the interference fringes. The interference fringes are formed from the inside to the surface of the reflection type volume hologram diffraction grating. The interference fringes satisfy the Bragg condition. Here, the Bragg condition refers to a condition that satisfies the following formula (A). In formula (A), m is a positive integer, λ is the wavelength, d is the pitch of the grating surface (the interval in the normal direction of the virtual plane including the interference fringes), and Θ is the complement angle of the angle of incidence on the interference fringes. In addition, when light enters the diffraction grating member at an incident angle ψ, the relationship between Θ, the slant angle φ, and the incident angle ψ is as shown in formula (B).

m・λ=2・d・sin(Θ) (A)
Θ=90°-(φ+ψ) (B)

As described above, the first diffraction grating member 330 is disposed (bonded) on the second surface 323 of the light guide plate 321, and diffracts (specifically, diffracts and reflects) the parallel light incident on the light guide plate 321 so that the parallel light incident on the light guide plate 321 from the first surface 322 is totally reflected inside the light guide plate 321. Furthermore, as described above, the second diffraction grating member 340 is disposed (bonded) on the second surface 323 of the light guide plate 321, and diffracts (specifically, diffracts and reflects multiple times) the parallel light propagated by total reflection inside the light guide plate 321, and emits the parallel light from the first surface 322 of the light guide plate 321 as parallel light.

Even in the light guide plate 321, the parallel light propagates through the inside by total reflection and is then emitted. At this time, since the light guide plate 321 is thin and the light path traveling inside the light guide plate 321 is long, the number of total reflections until it reaches the second diffraction grating member 340 varies depending on the angle of view. More specifically, of the parallel light incident on the light guide plate 321, the number of reflections of the parallel light incident at an angle approaching the second diffraction grating member 340 is less than the number of reflections of the parallel light incident on the light guide plate 321 at an angle away from the second diffraction grating member 340. This is because the angle formed by the light propagating inside the light guide plate 321 and the normal line of the light guide plate 321 when the light diffracted by the first diffraction grating member 330 and incident on the light guide plate 321 at an angle approaching the second diffraction grating member 340 collides with the inner surface of the light guide plate 321 is smaller than that formed by the parallel light incident on the light guide plate 321 at an angle in the opposite direction. In addition, the shape of the interference fringes formed inside the second diffraction grating member 340 and the shape of the interference fringes formed inside the first diffraction grating member 330 are symmetrical with respect to a virtual plane perpendicular to the axis of the light guide plate 321. The surfaces of the first diffraction grating member 330 and the second diffraction grating member 340 that do not face the light guide plate 321 may be covered with a transparent resin plate or transparent resin film to prevent damage to the first diffraction grating member 330 and the second diffraction grating member 340. In addition, a transparent protective film may be attached to the first surface 322 to protect the light guide plate 321 .

The light guide plate 321 in Example 4 described below basically has the same configuration and structure as the light guide plate 321 described above.

As described above, the display device of Example 3 has substantially the same configuration and structure as the display device of Example 1, except for the optical device 320, so a detailed description will be omitted.

Example 4 is also a modification of Example 1, but relates to an optical device of 1-B structure and an image forming device of the second configuration. A conceptual diagram of an image display device in a display device (head-mounted display) of Example 4 is shown in Figure 21. The light source 251, collimating optical system 252, scanning means 253, parallel light emitting optical system (relay optical system 254), etc. in the image display device 400 of Example 4 have the same configuration and structure as Example 2 (image forming device of the second configuration). Furthermore, the optical device 320 in Example 4 has the same configuration and structure as the optical device 320 in Example 3. The display device of Example 4 has substantially the same configuration and structure as the display device of Example 1, except for the above differences, so detailed description will be omitted.

Example 5 is also a modification of the image display device in Example 1, but relates to an optical device of a second structure and an image forming device of a second configuration. Figure 22 shows a schematic diagram of the display device of Example 5 viewed from above.

In the fifth embodiment, the optical device 520 constituting the image display device 500 is composed of semi-transparent mirrors 530A and 530B into which light emitted from the light sources 251A and 251B is incident and emitted toward the pupil 21 of the observer 20. In the fifth embodiment, the light emitted from the light source 251 (251A, 251B) arranged in the housing 213 propagates inside an optical fiber (not shown) and, for example, enters the scanning means 253 (253A, 253B) attached to the rim 11' near the nose pad portion 10', and the light scanned by the scanning means 253 enters the semi-transparent mirrors 530A and 530B. Alternatively, the light emitted from the light sources 251A and 251B arranged in the housing 213 propagates through the inside of an optical fiber (not shown) and enters, for example, the scanning means 253 (253A, 253B) attached above the parts of the rims 11' corresponding to both eyes, and the light scanned by the scanning means 253 enters the semi-transmitting mirrors 530A and 530B. Alternatively, the light emitted from the light sources 251A and 251B arranged in the housing 213, enters the scanning means 253 (253A, 253B) arranged in the housing 213, and is scanned by the scanning means 253 directly enters the semi-transmitting mirrors 530A and 530B. Then, the light reflected by the semi-transmitting mirrors 530A and 530B enters the pupil 21 of the observer 20. The image forming device can be substantially the image forming device 211 described in the second embodiment. Except for the above differences, the display device of Example 5 has substantially the same configuration and structure as the display device of Example 1, and therefore a detailed description thereof will be omitted.

Example 6 is a modification of Example 1. Figure 23A shows a schematic diagram of the display device of Example 6 viewed from above. Figure 23B shows a schematic diagram of a circuit that controls the illuminance sensor.

The display device of Example 6 further includes an illuminance sensor (environmental illuminance measurement sensor) 901 that measures the illuminance of the environment in which the display device is placed, and controls the light blocking rate of the dimming device 700 based on the measurement result of the illuminance sensor (environmental illuminance measurement sensor) 901. In addition, or independently, the brightness of the image formed by the image forming device 111, 211 is controlled based on the measurement result of the illuminance sensor (environmental illuminance measurement sensor) 901. The environmental illuminance measurement sensor 901 having a known configuration and structure may be disposed, for example, at the outer end of the dimming device 700. The environmental illuminance measurement sensor 901 is connected to the control device 18 via a connector and wiring not shown. The control device 18 includes a circuit that controls the environmental illuminance measurement sensor 901. The circuit that controls the environmental illuminance measuring sensor 901 is composed of an illuminance calculation circuit that receives a measurement value from the environmental illuminance measuring sensor 901 and calculates the illuminance, a comparison calculation circuit that compares the illuminance value calculated by the illuminance calculation circuit with a standard value, and an environmental illuminance measuring sensor control circuit that controls the light control device 700 and/or the image forming devices 111, 211 based on the value calculated by the comparison calculation circuit, and these circuits can be composed of known circuits. In controlling the light control device 700, the light blocking rate of the light control device 700 is controlled, while in controlling the image forming devices 111, 211, the brightness of the image formed by the image forming devices 111, 211 is controlled. The control of the light blocking rate in the light control device 700 and the control of the brightness of the image in the image forming devices 111, 211 may be performed independently or in a correlated manner.

For example, when the measurement result of the illuminance sensor (ambient illuminance measurement sensor) 901 is equal to or greater than a predetermined value (first illuminance measurement value), the light blocking rate of the dimming device 700 is set to equal to or greater than a predetermined value (first illuminance blocking rate). On the other hand, when the measurement result of the illuminance sensor (ambient illuminance measurement sensor) 901 is equal to or less than a predetermined value (second illuminance measurement value), the light blocking rate of the dimming device 700 is set to equal to or less than a predetermined value (second illuminance blocking rate). Here, the first illuminance measurement value can be 10 lux, the first illuminance blocking rate can be any value between 99% and 70%, the second illuminance measurement value can be 0.01 lux, and the second illuminance blocking rate can be any value between 49% and 1%.

The illuminance sensor (ambient illuminance measuring sensor) 901 in Example 6 can be applied to the display devices described in Examples 2 to 5. In addition, if the display device is equipped with an imaging device, the illuminance sensor (ambient illuminance measuring sensor) 901 can also be configured from a light receiving element for exposure measurement provided in the imaging device.

In the display device of Example 6 or Example 7 described below, the shading rate of the dimming device is controlled based on the measurement results of the illuminance sensor (ambient illuminance measurement sensor), the brightness of the image formed by the image forming device is controlled based on the measurement results of the illuminance sensor (ambient illuminance measurement sensor), the shading rate of the dimming device is controlled based on the measurement results of the second illuminance sensor (transmitted light illuminance measurement sensor), and the brightness of the image formed by the image forming device is controlled based on the measurement results of the second illuminance sensor (transmitted light illuminance measurement sensor).As a result, not only can a high contrast be imparted to the virtual image observed by the observer, but the viewing conditions of the virtual image can be optimized depending on the illuminance of the surrounding environment in which the display device is placed.

Example 7 is also a modification of Example 1. Figure 24A shows a schematic diagram of the display device of Example 7 viewed from above. Figure 24B shows a schematic diagram of a circuit that controls the second illuminance sensor.

The display device of Example 7 further includes a second illuminance sensor (transmitted light illuminance measurement sensor) 902 that measures the illuminance based on the light transmitted from the external environment through the light control device, that is, measures whether the ambient light is transmitted through the light control device and adjusted to the desired illuminance before entering, and controls the light blocking rate of the light control device 700 based on the measurement result of the second illuminance sensor (transmitted light illuminance measurement sensor) 902. In addition, or independently, the brightness of the image formed by the image forming device 111, 211 is controlled based on the measurement result of the second illuminance sensor (transmitted light illuminance measurement sensor) 902. The transmitted light illuminance measurement sensor 902 having a known configuration and structure is arranged on the observer side of the optical device 120, 320, 520. Specifically, the transmitted light illuminance measurement sensor 902 may be arranged, for example, on the inner surface of the housing 113, 213. The transmitted light illuminance measurement sensor 902 is connected to the control device 18 via a connector and wiring not shown. The control device 18 includes a circuit for controlling the transmitted light illuminance measuring sensor 902. The circuit for controlling the transmitted light illuminance measuring sensor 902 is composed of an illuminance calculation circuit for receiving a measured value from the transmitted light illuminance measuring sensor 902 and calculating an illuminance, a comparison calculation circuit for comparing the illuminance value calculated by the illuminance calculation circuit with a standard value, and a transmitted light illuminance measuring sensor control circuit for controlling the light control device 700 and/or the image forming devices 111 and 211 based on the value calculated by the comparison calculation circuit, and these circuits can be composed of known circuits. In controlling the light control device 700, the light blocking rate of the light control device 700 is controlled, while in controlling the image forming devices 111 and 211, the brightness of the image formed by the image forming devices 111 and 211 is controlled. The control of the light blocking rate in the light control device 700 and the control of the brightness of the image in the image forming devices 111 and 211 may be performed independently or in a correlated manner. Furthermore, when the measurement result of the transmitted light illuminance measuring sensor 902 cannot be controlled to the desired illuminance in consideration of the illuminance of the environmental illuminance measuring sensor 901, that is, when the measurement result of the transmitted light illuminance measuring sensor 902 does not reach the desired illuminance, or when even more delicate illuminance adjustment is desired, the light blocking rate of the light control device may be adjusted while monitoring the value of the transmitted light illuminance measuring sensor 902. At least two second illuminance sensors (transmitted light illuminance measuring sensors) may be disposed to measure the illuminance based on the light that has passed through the portion with a high illuminance blocking rate and the illuminance based on the light that has passed through the portion with a low illuminance blocking rate.

The second illuminance sensor (transmitted light illuminance measuring sensor) 902 in Example 7 can be applied to the display device described in Examples 2 to 5. Alternatively, the second illuminance sensor (transmitted light illuminance measuring sensor) 902 in Example 7 and the illuminance sensor (ambient illuminance measuring sensor) 901 in Example 6 may be combined. In this case, various tests may be performed, and the control of the light blocking rate in the light control device 700 and the control of the image brightness in the image forming devices 111 and 211 may be performed independently or in correlation with each other. By adjusting the voltages applied to the first electrode and the second electrode in each of the light control device for the right eye and the light control device for the left eye, the light blocking rate in the light control device for the right eye and the light blocking rate in the light control device for the left eye can be equalized. The potential difference between the first electrode and the second electrode may be controlled, or the voltage applied to the first electrode and the voltage applied to the second electrode may be controlled independently. The light blocking rate in the light control device for the right eye and the light blocking rate in the light control device for the left eye can be controlled, for example, based on the measurement results of the second illuminance sensor (transmitted light illuminance measurement sensor) 902, or the observer 20 can manually control and adjust the light blocking rate by observing the brightness of the light that has passed through the light control device and the optical device for the right eye and the brightness of the light that has passed through the light control device and the optical device for the left eye and operating a switch, button, dial, slider, knob, etc.

Example 8 is a modification of Examples 1 to 7. In the light control device of Example 8, a moisture retaining member is disposed at least between the second electrode and the second substrate.

As shown in a schematic cross-sectional view of FIG. 25A, the light control device 700′ in the eighth embodiment has the following features:
First substrate 711A,
a second substrate 711B disposed opposite the first substrate 711A and receiving external light;
a light control layer 716 provided between the first substrate 711A and the second substrate 711B;
Equipped with
A first electrode 712A is provided between the light control layer 716 and the first substrate 711A.
A second electrode 712B is provided between the light-controlling layer 716 and the second substrate 711B. The light-controlling layer 716 has a laminated structure of a reduction coloring layer 713, an electrolyte layer 714, and an oxidation coloring layer 715.

And, a moisture retaining member 721 is disposed at least between the second electrode 712B and the second substrate 711B. The end face of the moisture retaining member 721 is exposed to the outside. At least a part of the end (side) of the dimming device 700' is composed of a sealing member 723 and a moisture retaining member 721 from the first substrate side. That is, at least a part of the end of the dimming device 700' is composed of a laminated structure of the sealing member 723 and the moisture retaining member extension portion 722 extending from the moisture retaining member 721 from the first substrate side. The sealing member 723 is provided, for example, on the edge portion of the first substrate 711A.

The second electrode 712B is formed from above the dimming layer 716 onto the first substrate 711A, and is spaced apart from the first electrode 712A, and the moisture retaining member 721 covers at least the second electrode 712B and the dimming layer 716. That is, the first electrode 712A is formed on the first substrate 711A, the dimming layer 716 is formed on the first electrode 712A, the second electrode 712B is formed at least on the dimming layer 716, and the moisture retaining member 721 covers at least the second electrode 712B and faces the second substrate 711B. Between the sealing member 723 and the second substrate 711B, a moisture retaining member extension portion 722 extending from the moisture retaining member 721 is disposed. Furthermore, a part of the sealing member 723 is composed of an auxiliary electrode (not shown) made of copper (Cu). The remaining portion of the sealing member 723 is made of resin, specifically, an acrylic adhesive. The auxiliary electrodes are made of a first auxiliary electrode (not shown) formed on the first electrode 712A, and a second auxiliary electrode (not shown) formed on the second electrode 712B at a distance from the first auxiliary electrode. The sealing member 723 and the moisture retaining member extension 722 form a side wall of the light control device 700'. The sealing member 723 is provided without any gaps.

The resin constituting the moisture-retaining member 721 and the moisture-retaining member extension portion 722, which can also be called a proton supply member, a transparent adhesive member capable of retaining moisture, or a transparent sealing member capable of retaining moisture, may be appropriately selected from acrylic resins, silicone resins, or urethane resins, and in Example 8, is specifically composed of an acrylic resin.

By forming the moisture retention member 721 and the moisture retention member extension 722 from a material with a Young's modulus of 1×10 ⁶ Pa or less, it is possible to absorb various steps occurring inside the light control device, and to reduce the variation in the thickness of the moisture retention member 721 and the thickness of the moisture retention member extension 722 at the center of the light control device. That is, it is possible to uniformize the entire distance between the first substrate 711A and the second substrate 711B. As a result, it is possible to prevent the occurrence of deterioration in visibility. Specifically, when the outside world is viewed through the light control device 700', it is possible to suppress the occurrence of distortion or deviation in the image of the outside world.

The first electrode 712A and the second electrode 712B made of ITO or IZO are not patterned and are so-called solid electrodes. A connector (not shown) is attached to a part of the auxiliary electrode of the dimming device 700', and the first electrode 712A and the second electrode 712B are electrically connected to a control unit 30 for controlling the light blocking rate of the dimming device 700'.

When moisture disappears from inside the electrochromic element, the electrochromic element no longer changes color. However, in the dimming device of Example 8, moisture enters and exits through the end face of the moisture-retaining member extension (the side wall of the dimming device), so problems such as reduced reliability of the dimming device, image display device, or display device can be avoided. Furthermore, by providing an auxiliary electrode, an appropriate voltage can be easily applied to the first electrode and the second electrode, and the occurrence of a voltage drop in the first electrode or the second electrode can be suppressed, thereby reducing the occurrence of unevenness when coloring the dimming device.

Example 9 is also a modification of Examples 1 to 7. In the light control device of Example 9, the light control device is composed of a type of optical shutter using an electrodeposition method (electrodeposition method or field deposition method) that applies the electrodeposition/dissociation phenomenon that occurs due to a reversible oxidation-reduction reaction of a metal (e.g., silver particles). A schematic cross-sectional view of the light control device of Example 9 is shown in Figure 25B.

In such a dimming device, when the dimming layer is composed of an electrolyte layer containing metal ions, it is desirable that the metal ions consist of silver ions and that the electrolyte contain at least one type of salt (referred to as a "supporting electrolyte salt") selected from the group consisting of LiX, NaX and KX (wherein X is a fluorine atom, a chlorine atom, a bromine atom or an iodine atom).

It is preferable that the coloring and decoloring of the light control device (specifically, an electrodeposition type light control device) occur due to the deposition of a metal (e.g., silver) on the second electrode and the dissolution of the metal (e.g., silver) in the electrolyte based on the application of a voltage to the first electrode and the second electrode. If the metal ions are silver ions and the second electrode is made of silver, that is, if the metal material constituting the second electrode and the metal ions are made of the same metal, an electrochemically stable electrode reaction can be realized.

The electrolyte contains metal ions as materials that are colored (colored) by electrochemical reduction and oxidation, and the associated precipitation and dissolution. The electrochemical precipitation and dissolution reaction of the metal ions causes coloring (coloring) and decoloring, and the light blocking rate of the light control device changes. In other words, the operation of the light control device in such a display device can be said to be an operation that reversibly causes the deposition of metal by electrolytic plating and the dissolution reaction of the deposited metal. In this way, metal ions that can realize coloring (coloring) and decoloring by electrochemical deposition and dissolution are not particularly limited, but in addition to the above-mentioned silver (Ag), bismuth (Bi), copper (Cu), sodium (Na), lithium (Li), iron (Fe), chromium (Cr), nickel (Ni), and cadmium (Cd) ions and combinations of these ions can be exemplified, and among them, particularly preferred metal ions are silver (Ag) and bismuth (Bi). Silver and bismuth can easily undergo a reversible reaction and cause a high degree of discoloration when deposited.

The electrolyte contains metal ions, specifically, a substance containing metal ions is dissolved in the electrolyte. More specifically, the substance containing metal ions is, for example, at least one type of silver halide such as AgF, AgCl, AgBr, or AgI, preferably AgI or AgBr, and this substance containing metal ions is dissolved in the electrolyte. The concentration of the silver halide can be, for example, 0.03 to 2.0 mol/liter.

An electrolyte containing metal ions is sealed between the first and second substrates, and the electrolyte can be composed of an electrolytic solution or a polymer electrolyte. A solvent containing a metal salt or an alkyl quaternary ammonium salt can be used as the electrolytic solution. Specifically, the electrolyte can be water, ethyl alcohol, isopropyl alcohol, 2-ethoxyethanol, 2-methoxyethanol, propylene carbonate, dimethyl carbonate, ethylene carbonate, γ-butyrolactone, acetonitrile, sulfolane, dimethoxyethane, dimethylformamide (DMF), diethylformamide (DEF), dimethylsulfoxide (DMSO), N,N-dimethylacetamide (DMAA), N-methylpropionic acid amide (MPA), N-methylpyrrolidone (MP), dioxolane (DOL), ethyl acetate (EA), tetrahydrofuran (THF), methyltetrahydrofuran (MeTHF), or a mixture thereof. Examples of the matrix (base) polymer used in the polymer electrolyte include polymer materials having repeating units of alkylene oxide, alkylene imine, or alkylene sulfide in the main skeleton unit, the side chain unit, or the main skeleton unit and the side chain unit, or copolymers containing a plurality of different units thereof, or polymethyl methacrylate derivatives, polyvinylidene fluoride, polyvinylidene chloride, polyacrylonitrile, polycarbonate derivatives, or mixtures thereof. When the electrolyte is made of a polymer electrolyte, the electrolyte may be a single layer, or may have a laminate structure in which a plurality of polymer electrolytes are laminated.

It is also possible to use a matrix polymer that is swollen by adding water or an organic solvent. In particular, when a high response speed is required, adding water or an organic solvent to the matrix polymer makes it easier for the metal ions contained in the electrolyte to move.

Depending on the characteristics of the matrix polymer and the desired electrochemical reaction, if hydrophilicity is required, it is preferable to add water, ethyl alcohol, isopropyl alcohol, or a mixture of these, and if hydrophobicity is required, it is preferable to add propylene carbonate, dimethyl carbonate, ethylene carbonate, γ-butyrolactone, acetonitrile, sulfolane, dimethoxyethane, ethyl alcohol, isopropyl alcohol, dimethylformamide, dimethyl sulfoxide, dimethylacetamide, n-methylpyrrolidone, or a mixture of these.

As described above, the application of a voltage to the first electrode and the second electrode causes the deposition of metal on the second electrode and the dissolution of the metal in the electrolyte, resulting in coloring and decoloring of the light control device (specifically, an electrodeposition type light control device). Generally, the surface of the layer (metal layer) made of the metal deposited on the second electrode that comes into contact with the electrolyte is uneven and appears black, while the surface of the metal layer that comes into contact with the second electrode is mirror-like. Therefore, when used as a light control device, it is desirable that the surface of the metal layer that comes into contact with the electrolyte faces the viewer. In other words, it is preferable that the first substrate is disposed closer to the viewer than the second substrate.

It is preferable that the second electrode is not patterned within the effective area of the dimming device. That is, it is preferable that the portion of the second electrode occupying the effective area of the dimming device is configured from an unpatterned transparent electrode layer (so-called solid transparent electrode layer). Specifically, it is preferable that the size of the projected image of the unpatterned second electrode is the same as or larger than the projected image of the second deflection means. The portion of the second electrode that is drawn out to the outside may be patterned.

As described above, by adding a salt (supporting electrolyte salt) containing an ion species different from the metal ion species to be precipitated/dissolved to the electrolyte, the electrochemical precipitation/dissolution reaction can be performed more effectively and stably. Examples of such supporting electrolyte salts include the above-mentioned lithium salts, potassium salts, sodium salts, and tetraalkyl quaternary ammonium salts. Specific examples of the lithium salts include LiCl, LiBr, LiI, LiBF ₄ , LiClO ₄ , LiPF ₆ , and LiCF ₃ SO _3. Specific examples of the potassium salts include KCl, KI, and KBr. Specific examples of the sodium salts include NaCl, NaI, and NaBr. Specific examples of the tetraalkyl quaternary ammonium salts include tetraethylammonium borofluoride salts, tetraethylammonium perchlorate salts, tetrabutylammonium borofluoride salts, tetrabutylammonium perchlorate salts, and tetrabutylammonium halide salts. The alkyl chain length of the quaternary ammonium salt may be non-uniform. The supporting electrolyte salt may be added at a concentration, for example, about 1/2 to 5 times that of the substance containing metal ions. In addition, inorganic particles may be mixed as a colorant into the electrolyte consisting of a polymer electrolyte.

In addition, in order to perform electrochemical reactions, particularly metal deposition and dissolution, reversibly and efficiently, at least one type of additive such as a growth inhibitor, a stress suppressor, a glossing agent, a complexing agent, or a reducing agent may be added to the electrolyte. As such an additive, an organic compound having a group having an oxygen atom or a sulfur atom is preferable, and for example, at least one type selected from the group consisting of thiourea, 1-allyl-2-thiourea, mercaptobenzimidazole, coumarin, phthalic acid, succinic acid, salicylic acid, glycolic acid, dimethylamine borane (DMAB), trimethylamine borane (TMAB), tartaric acid, oxalic acid, and D-glucono-1,5-lactone is preferably added. In particular, the addition of mercaptobenzimidazole (see the structural formula below), which is similar to mercaptoalkylimidazole, is preferable because it improves reversibility and provides excellent long-term and high-temperature storage properties.

但し、Ｒ１，Ｒ２，Ｒ３は、それぞれ、水素原子、あるいは、Ｃ_nＨ_2n+1（但し、ｎは１以上の整数）で示されるアルキル基である。

Here, R1, R2 and R3 are each a hydrogen atom or an alkyl group represented by C _n H _2n+1 (wherein n is an integer of 1 or more).

In addition, when an electrochemical reaction occurs, side reactions other than the intended reaction may occur. For example, if the electrolyte contains salts including halides, these may be oxidized from their ionic state by the following reaction depending on the potential. This may result in a color other than the desired color.

I ₂ + 2e ^- → or ← 2I ^- (0.536V)
_Br2 + ^2e- → or ← ^2Br- (1.065V)
_Cl2 + ^2e- → or ← ^2Cl- (1.360V)

Therefore, to eliminate the occurrence of this unwanted coloring, it is necessary to suppress the above-mentioned side reaction and reduce the oxidized halide. In this case, a general reducing agent can be used as the reducing agent, and it may be added to the electrolyte as an additive. For example, ascorbic acid compounds and trialkyl alcohol amines represented by the following formula are suitable as such reducing agents.

In particular, triethanolamine, which is a trialkyl alcohol amine and is represented by the following formula, is preferred because adding it to the electrolyte provides excellent long-term and high-temperature storage properties.

In addition, an oxidizing agent is added when a reduction reaction occurs due to a side reaction other than the specified reaction. Therefore, it is preferable to add a reducing agent or oxidizing agent to the electrolyte in order to suppress side reactions mainly caused by anion species that may occur at both the first and second electrodes when the metal is precipitated.

In the dimming device of Example 9, the distance between the first electrode and the second electrode is preferably 20 μm to 200 μm. The shorter the distance between the first electrode and the second electrode, the lower the electrical resistance between the electrodes, which leads to a shorter coloring/decoloring time and a lower power consumption, and is therefore preferable. However, if the distance between the first electrode and the second electrode is less than 20 μm, the mechanical strength decreases, and there is a risk of pinholes or cracks occurring. In addition, if the distance between the first electrode and the second electrode is too short, there is a risk of uneven coloring due to biased concentration of the electric field, and uneven contrast when the observer is watching the image.

The first and second substrates are sealed and bonded together at their outer edges with a sealant. As the sealant, also called a sealant, various resins such as epoxy resin, urethane resin, acrylic resin, vinyl acetate resin, ene-thiol resin, silicone resin, modified polymer resin, etc., such as thermosetting, photosetting, moisture-curing, and anaerobic curing resins, can be used. The electrolyte may contain a columnar structure as necessary. The columnar structure provides strong self-holding (strength) between the substrates, and is composed of columnar structures such as cylindrical bodies, square columns, elliptical columns, and trapezoidal columns arranged at regular intervals based on a predetermined pattern such as a lattice arrangement. It is also possible to use stripes arranged at regular intervals. It is preferable that the columnar structures are arranged not randomly, but at regular intervals, at intervals that gradually change, or in a predetermined arrangement pattern that is repeated at regular intervals, so that the spacing between the substrates can be appropriately maintained and the passage of light in the light control device is not hindered. Spacers may be disposed between the pair of substrates to keep the gap between the substrates uniform. Examples of spacers include spheres made of resin or inorganic oxide. Spacers whose surfaces are coated with thermoplastic resin may also be suitably used. To keep the gap between the substrates uniform, only columnar structures may be disposed, or both spacers and columnar structures may be disposed, or only spacers may be disposed instead of columnar structures. When used in combination with columnar structures, the diameter of the spacer is equal to or less than the height of the columnar structures, and preferably equal to the height of the columnar structures. When no columnar structures are disposed, the diameter of the spacer corresponds to the thickness of the gap between the pair of substrates.

The first electrode is preferably made of nanowires, and the average diameter of the nanowires is preferably 1 μm or less, and more preferably 0.5 μm or less. The average length of the nanowires (average length in the long axis direction) is preferably 1×10 ⁻⁶ m or more and 5×10 ⁻⁴ m or less, preferably 5×10 ⁻⁶ m or more and 2.5×10 ⁻⁴ m or less, and more preferably 1×10 ⁻⁵ mm or more and 1×10 ⁻⁴ m or less. The average diameter of the nanowires (average length in the short axis direction) is, as described above, 1 μm (1×10 ⁻⁶ m) or less, but is preferably 5×10 ⁻⁹ m or more and 5×10 ⁻⁷ m or less, more preferably 1×10 ⁻⁸ m or more and 1×10 ⁻⁷ m or less, and even more preferably 1×10 ⁻⁸ m or more and 5×10 ⁻⁸ m or less. If the average length of the nanowires is less than 1×10 ⁻⁶ m, for example, when the first electrode is formed based on a coating method or a printing method, the number of contact points between the nanowires is reduced, making it difficult to obtain electrical continuity, and as a result, there is a risk that the electrical resistance of the first electrode will be high. On the other hand, if it exceeds 5×10 ⁻⁴ m, the nanowires will be too easily entangled, and there is a risk that the dispersion stability will be poor. If the average diameter of the nanowires exceeds 1×10 ⁻⁶ m, the characteristics as a conductor will be improved, but there is a risk that haze due to light scattering will be noticeable and transparency will be lost. On the other hand, if the average diameter of the nanowires is less than 5×10 ⁻⁹ m, there is a risk that the transparency will be improved, but the conductivity will be deteriorated due to oxidation.

The conductive material constituting the first electrode can be any material that is electrochemically stable, specifically, metal materials such as silver (Ag), bismuth (Bi), platinum (Pt), chromium (Cr), aluminum (Al), cobalt (Co), and palladium (Pd) can be mentioned, among which, for reasons described later, it is preferable to use silver (Ag). The first electrode can be obtained, for example, by dispersing nanowires made of a conductive material in a solvent, coating or printing them on the first substrate, and subjecting them to heat treatment, or by dispersing fine particles made of a conductive material in a solvent, coating or printing them on the first substrate, and subjecting them to heat treatment. In these cases, the first electrode is not patterned. Specifically, it is preferable that the portion of the first electrode that occupies the effective area of the dimming device is not patterned. Here, the effective area of the dimming device refers to an area that is the same as or larger than the projected image of the second deflection means described later. The same applies below. That is, it is preferable that the size of the projection image of the unpatterned portion of the first electrode is equal to or larger than the projection image of the second deflection means described later. The portion of the first electrode that is drawn out to the outside can be made of a conductive material. Alternatively, it can be obtained by forming a thin metal film on the first substrate and then randomly (or irregularly or disorderly) patterning the thin metal film. Carbon (e.g., carbon nanotubes) can also be used as the conductive material, and in this case, it is sufficient to make it into an ink using a resin and a solvent and print it on the first substrate.

By forming the first electrode using nanowires based on a coating method or a printing method, a first electrode in which the nanowires are randomly (or irregularly or disorderly) arranged can be obtained, and as a result, the diffraction phenomenon of the light passing through the first electrode can be effectively prevented. Furthermore, as described above, by making the average diameter of the nanowires 1 μm or less, preferably 0.5 μm or less, the diffraction phenomenon of the light passing through the first electrode can be more effectively prevented, and the light scattering intensity can be reduced. For example, when a fluorescent lamp is viewed through a dimmer, if the diffraction phenomenon occurs in the light passing through the first electrode, the fluorescent lamp appears rainbow-colored, and the visibility becomes extremely poor. However, by preventing the diffraction phenomenon from occurring in the light passing through the first electrode, such problems can be reliably avoided.

Examples of the second electrode include so-called transparent electrodes, and specific examples thereof include indium-tin composite oxides (ITO, indium tin oxide, including Sn-doped In ₂ O ₃ , crystalline ITO, and amorphous ITO), fluorine-doped SnO ₂ (FTO), IFO (F-doped In ₂ O ₃ ), antimony-doped SnO ₂ (ATO), SnO ₂ , ZnO (including Al-doped ZnO and B-doped ZnO), indium-zinc composite oxides (IZO, indium zinc oxide), spinel-type oxides, oxides having a YbFe ₂ O ₄ structure, polyaniline, polypyrrole, polythiophene, and other conductive polymers, but are not limited to these. Furthermore, two or more of these can be used in combination. The second electrode can be formed based on a physical vapor deposition method (PVD method) such as a vacuum deposition method or a sputtering method, various chemical vapor deposition methods (CVD methods), various coating methods, etc. The electrode can be patterned by any method such as an etching method, a lift-off method, or a method using various masks.

Below, a specific example of the dimming device 800 of Example 9 is described.

The light control device 800 of the ninth embodiment is
A transparent first substrate 801 and a transparent second substrate 803 facing the first substrate 801;
A first electrode 802 provided on a first substrate 801;
A second electrode 804 provided on a second substrate 803; and
an electrolyte 805 containing metal ions sealed between the first substrate 801 and the second substrate 803;
It consists of
The first electrode 802 is made of a thin wire of a conductive material.
The second electrode 804 is composed of a transparent electrode layer.

The first substrate 801 is disposed closer to the observer than the second substrate 803. The first electrode 802 is made of nanowires, and the average diameter of the nanowires is 1 μm or less. More specifically, the conductive material constituting the first electrode 802 is silver (Ag), and the first electrode 802 is made of silver nanowires. The average length (length in the long axis direction) of the silver nanowires and the average diameter (length in the short axis direction) of the nanowires are 4×10 ⁻⁴ m and 5×10 ⁻⁷ m, respectively. The first electrode 802 is made of silver nanowires arranged randomly (or irregularly or disorderly), but is shown in a layered state in the drawing. The metal ions are made of silver (Ag) ions, and the electrolyte 805 contains a supporting electrolyte salt made of LiI. By using silver ions as the metal ions and constituting the second electrode 804 from silver, that is, by using the same metal as the metal material constituting the second electrode 804 and the metal ions, an electrochemically stable electrode reaction can be realized. The first substrate 801 and the second substrate 803 are made of glass having a thickness of 0.4 mm, and the distance between the first substrate 801 and the second substrate 803 is 100 μm. The second electrode 804 is made of a transparent electrode made of indium-tin composite oxide (ITO), and is formed based on a combination of a PVD method such as a sputtering method and a lift-off method. The first electrode 802 is not patterned, and the second electrode 804 is not patterned either, and these electrodes are so-called solid electrodes. Specifically, the portions of the first electrode 802 and the second electrode 804 that occupy the effective area of the light control device 800 are not patterned. Here, the effective area of the light control device 800 refers to an area that is the same as the projected image of the second deflection means 140, 340, or is larger than the projected image. More specifically, the size of the projection image of the unpatterned portion of the first electrode 802 and the portion of the second electrode 804 is larger than the projection image of the second deflection means 140, 340. The portion leading out the first electrode 802 to the outside is made of another conductive material (not shown). The portion leading out the second electrode 804 to the outside is patterned. The first electrode 802 and the second electrode 804 are connected to the control device 18 via a connector and wiring (not shown). The outer edges of the two substrates 801, 803 are sealed with a sealant 806. Furthermore, the first substrate 801 of the light control device 800 is fixed to the light guide plate 121 by a sealing member, and a gap is provided between the first substrate 801 and the light guide plate 121. The first substrate 801 of the light control device 800 has a length approximately equal to that of the light guide plate 121, and the first substrate 801 of the light control device 800 is fixed to the light guide plate 121 by a sealing member. The sealing member is disposed on the outer edge of the first substrate 801.

The first electrode 802 can be obtained by printing a dispersion of silver nanowires in a solvent onto the first substrate 801 using a screen printing method and then subjecting it to a heat treatment.

A barrier layer (not shown, for example, made of an inorganic material, specifically, alumina) may be formed between the first substrate 801 and the first electrode 802, and between the second substrate 803 and the second electrode 804. Furthermore, a protective layer made of a SiN layer, a _SiO2 layer, an _{Al2O3 layer} , a _TiO2 layer, or a laminated film of these may be formed between the second electrode 804 and the barrier layer. By forming the protective layer, it is possible to impart ion blocking properties that prevent ions from passing back and forth, waterproof properties, moisture resistance, and scratch resistance to the light control device.

1 part by weight of polyether with a molecular weight of approximately 350,000, 10 parts by weight of dimethyl sulfoxide (DMSO), 1.7 parts by weight of sodium iodide, and 1.7 parts by weight of silver iodide were mixed and heated to 120°C to prepare a homogeneous solution. Triethanolamine, coumarin (see formula below), and benzimidazole (see formula below) were then added to this solution to obtain electrolyte 805. Note that 10 grams of triethanolamine, 1.5 grams of coumarin, and 1.5 grams of benzimidazole were added per liter of this solution.

Then, the first substrate 801 on which the first electrode 802 is formed and the second substrate 803 on which the second electrode 804 is formed are sealed at their outer edges using an olefin-based sealant 806. The sealant 806 contains 10% by volume of spacers (not shown) made of plastic spherical beads with an average particle size of 100 μm. An opening (injection port) is provided in a part of the sealant. Then, an electrolyte 805 containing AgI is vacuum-injected from the opening provided in the sealant into the inside of the cell in which the first substrate 801 and the second substrate 803 thus obtained are bonded together, and then the opening is sealed to obtain the light control device 800.

The application of a voltage to the first electrode 802 and the second electrode 804 causes the deposition of silver on the second electrode 804 and the dissolution of silver into the electrolyte 805, resulting in coloring and decoloring of the light control device (specifically, an electrodeposition type light control device). This makes it possible to control the light transmittance of the light control device 800. Specifically, when a relatively positive voltage is applied to the first electrode 802 and a relatively negative voltage is applied to the second electrode 804, the following occurs on the second electrode 804:
Ag ^{++ e-} → Ag
Based on the above reaction, silver is precipitated and a thin silver layer is formed on the second electrode 804. Therefore, the light transmittance of the light control device 800 is low. On the other hand, conversely, when a negative voltage is applied to the first electrode 802 and a positive voltage is applied to the second electrode 804,
Ag → Ag ⁺ + e ^-
The above reaction occurs, and the silver deposited on the second electrode 804 dissolves in the electrolyte 805. As a result, the second electrode 804, which was in a colored state, becomes transparent. Therefore, the light transmittance in the light control device 800 is high. The light transmittance in the light control device 800 can be controlled based on the value of the voltage applied to the first electrode 802 and the second electrode 804 and the application time. The voltage applied to the first electrode 802 and the second electrode 804 can be controlled by an observer operating a control knob provided on the control device 18. That is, the observer observes the image from the optical device 120, 320 and adjusts the light transmittance of the light control device 800 to improve the contrast of the image. In addition, as a result of various tests, it was found that the maximum light transmittance of the light control device 800 is 50% or more (preferably 50% or more and 99% or less) and the minimum light transmittance is 30% or less (preferably 1% or more and 30% or less).

In the display device of Example 9, the light control device is composed of a so-called electrodeposition type light control device having a first electrode made of a thin conductive material and a second electrode made of a transparent electrode layer, so that it is possible to provide a display device that can provide high contrast to the image observed by the observer, consumes little power, and can sufficiently increase the amount of external light incident on the image display device. Moreover, by forming the first electrode using silver nanowires based on a printing method, it is possible to obtain a first electrode in which the silver nanowires are randomly (or irregularly or disorderly) arranged, and as a result, it is possible to effectively prevent the diffraction phenomenon from occurring in the light that has passed through the first electrode. Moreover, by setting the average diameter of the silver nanowires as described above, it is possible to more effectively prevent the diffraction phenomenon from occurring in the light that has passed through the first electrode, and to reduce the light scattering intensity.

Although the present disclosure has been described above based on preferred embodiments, the present disclosure is not limited to these embodiments. The configurations and structures of the display device (head-mounted display) and image display device described in the embodiments are illustrative and can be modified as appropriate. For example, a surface relief hologram (see US Patent No. 20040062505A1) may be arranged on the light guide plate. In the optical device 320, the diffraction grating element can be configured as a transmission type diffraction grating element, or one of the first deflection means and the second deflection means can be configured as a reflection type diffraction grating element and the other can be configured as a transmission type diffraction grating element. Alternatively, the diffraction grating element can be a reflection type blazed diffraction grating element. The display device of the present disclosure can also be used as a stereoscopic display device. In this case, a polarizing plate or a polarizing film can be detachably attached to the optical device as necessary, or a polarizing plate or a polarizing film can be attached to the optical device.

In the embodiment, the image forming devices 111 and 211 are described as displaying a monochromatic (e.g., green) image, but the image forming devices 111 and 211 can also display color images. In this case, the light source may be configured to emit, for example, red, green, and blue light. Specifically, for example, the red light, green light, and blue light emitted from the red light-emitting element, the green light-emitting element, and the blue light-emitting element may be mixed and luminance-uniformed using a light pipe to obtain white light. In some cases, the light passing through the dimmer may be colored to a desired color by the dimmer, and in this case, the color colored by the dimmer may be variable. Specifically, for example, a dimmer colored red, a dimmer colored green, and a dimmer colored blue may be stacked.

The image display devices described in Examples 1 to 9 can also be modified as described below. That is, as shown in Fig. 26, which is a schematic diagram viewed from above, a light-shielding member 903 is formed on the outer surface of the light control device 700' facing the first diffraction grating member 330 to prevent light from leaking out of the light guide plate 321 and reducing the light utilization efficiency.

Alternatively, the optical device in the image display device described in Examples 3 and 4 can be modified as described below. That is, as shown in FIG. 27A, a conceptual diagram of an optical device in a modified example of the display device of Example 1, the hologram diffraction grating on the light incident side can be a transmission type diffraction grating element 330B, and the hologram diffraction grating on the light exit side can be a reflection type diffraction grating element 340A. Note that light enters from the transmission type diffraction grating element 330B side, and light exits from the transmission type diffraction grating element 340B side. Alternatively, as shown in FIG. 27B, a conceptual diagram of an optical device in a modified example of the display device of Example 1, the hologram diffraction grating on the light incident side can be a reflection type diffraction grating element 330A, and the hologram diffraction grating on the light exit side can be a transmission type diffraction grating element 340B. Alternatively, as shown in Fig. 27C, the hologram diffraction grating on the light incident side can be a transmission type diffraction grating element 330B, and the hologram diffraction grating on the light exit side can be a transmission type diffraction grating element 340B. Alternatively, as shown in Fig. 27D, the hologram diffraction grating on the light incident side can be a reflection type diffraction grating element 330A and a transmission type diffraction grating element 330B, and the hologram diffraction grating on the light exit side can be a reflection type diffraction grating element 340A. Alternatively, as shown in Fig. 27E, the hologram diffraction grating on the light incident side can be a reflection type diffraction grating element 330A and a transmission type diffraction grating element 330B, and the hologram diffraction grating on the light exit side can be a transmission type diffraction grating element 340B. Alternatively, as shown in Fig. 27F, the hologram diffraction grating on the light incident side can be a reflective diffraction grating element 330A, and the hologram diffraction grating on the light exit side can be a reflective diffraction grating element 340A and a transmission type diffraction grating element 340B, as shown in Fig. 27G, the hologram diffraction grating on the light incident side can be a transmission type diffraction grating element 330B, and the hologram diffraction grating on the light exit side can be a reflective diffraction grating element 340A and a transmission type diffraction grating element 340B, as shown in Fig. 27H, the hologram diffraction grating on the light incident side can be a reflective diffraction grating element 330A and a transmission type diffraction grating element 330B, and the hologram diffraction grating on the light exit side can be a reflective diffraction grating element 340A and a transmission type diffraction grating element 340B, as shown in Fig. 27H, the optical device in the modified display device of the modified example of the display device of the first embodiment.

The image display devices described in Examples 3 and 4 can also be modified as described below. That is, as shown in FIG. 28, which is a conceptual diagram of an optical device and a light control device in a modified example of the display device of Example 1, a first reflective volume hologram diffraction grating 351, a second reflective volume hologram diffraction grating 352, and a third reflective volume hologram diffraction grating 353 may be provided. In the first reflective volume hologram diffraction grating 351, the interference fringes of the diffraction grating member extend approximately in the Y direction. In the second reflective volume hologram diffraction grating 352, the interference fringes of the diffraction grating member extend in an oblique direction. In the third reflective volume hologram diffraction grating 353, the interference fringes of the diffraction grating member extend approximately in the X direction. The light beam emitted from the image forming device 111, 111', 211 is diffracted in the X direction by the first reflection type volume hologram diffraction grating 351, propagates through the light guide plate 321, and enters the second reflection type volume hologram diffraction grating 352. The light beam is then diffracted obliquely downward by the second reflection type volume hologram diffraction grating 352, and enters the third reflection type volume hologram diffraction grating 352. The light beam is then diffracted in the Z direction by the third reflection type volume hologram diffraction grating 353, and enters the pupil 21 of the observer 20.

Figures 29A and 29B are schematic diagrams viewed from above of a modified optical device constituting the optical device of the second structure described in Example 5.

In the example shown in FIG. 29A, light from a light source 601 enters a light guide member 602 and collides with a polarizing beam splitter 603 provided in the light guide member 602. Of the light from the light source 601 that collides with the polarizing beam splitter 603, the P-polarized component passes through the polarizing beam splitter 603, and the S-polarized component is reflected by the polarizing beam splitter 603 and heads toward a liquid crystal display device (LCD) 604 made of LCOS as a light valve. An image is formed by the liquid crystal display device (LCD) 604. Since the polarized component of the light reflected by the liquid crystal display device (LCD) 604 is dominated by the P-polarized component, the light reflected by the liquid crystal display device (LCD) 604 passes through the polarizing beam splitters 603 and 605, passes through a quarter-wave plate 606, collides with and is reflected by a reflector 607, passes through the quarter-wave plate 606, and heads toward the polarizing beam splitter 605. At this time, the polarization component of the light is dominated by the S-polarized component, so it is reflected by the polarizing beam splitter 605 and heads toward the pupil 21 of the observer 20. As described above, the image forming device is composed of the light source 601 and the liquid crystal display (LCD) 604, the optical device is composed of the light guiding member 602, the polarizing beam splitters 603 and 605, the quarter-wave plate 606, and the reflector 607, and the polarizing beam splitter 605 corresponds to the virtual image forming region of the optical device.

29B, light from image forming device 611 travels through light guiding member 612 and collides with semi-transparent mirror 613, some of the light passes through semi-transparent mirror 613, collides with reflector 614 and is reflected, collides with semi-transparent mirror 613 again, some of the light is reflected by semi-transparent mirror 613, and travels toward pupil 21 of observer 20. As described above, the optical device is composed of light guiding member 612, semi-transparent mirror 613, and reflector 614, and semi-transparent mirror 613 corresponds to the virtual image forming region of the optical device.

Alternatively, Figs. 30A and 30B show schematic diagrams of an optical device in another modified example of the display device of Example 5, viewed from above and from the side. This optical device is composed of a hexahedral prism 622 and a convex lens 625. Light emitted from the image forming device 621 enters the prism 622, collides with and is reflected by the prism surface 623, travels through the prism 622, collides with and is reflected by the prism surface 624, and reaches the pupil 21 of the observer 20 via the convex lens 625. The prism surfaces 623 and 624 are inclined in the direction facing each other, and the planar shape of the prism 622 is a trapezoid, specifically, an isosceles trapezoid. The prism surfaces 623 and 624 are mirror-coated. If the thickness (height) of the portion of the prism 622 facing the pupil 21 is made thinner than 4 mm, which is the average human pupil diameter, the observer 20 can see an image of the outside world superimposed on a virtual image from the prism 622.

In some cases, the first electrode and/or the second electrode may be divided into a plurality of blocks, and the light blocking rate in each block may be controlled to control the light blocking rate of the light control device from a first predetermined region in the region facing the virtual image formation region to a second predetermined region in the region facing the virtual image formation region. Alternatively, the first electrode or the second electrode may be a strip-shaped electrode or a mesh-shaped electrode, or a strip-shaped auxiliary electrode or a mesh-shaped auxiliary electrode may be formed on the first electrode or the second electrode, to independently control the light blocking rate in a plurality of regions of the light control device, thereby controlling the light blocking rate of the light control device from a first predetermined region in the region facing the virtual image formation region to a second predetermined region in the region facing the virtual image formation region.

The present disclosure may also be configured as follows.
[A01] 《Light control device》
A first electrode,
a second electrode facing the first electrode;
A light-controlling layer sandwiched between a first electrode and a second electrode; and
A control unit for controlling coloring and decoloring of the light-controlling layer;
It is equipped with
The control unit includes a secondary battery, a control circuit, and a capacitor.
The control unit
(A) charging a capacitor with a secondary battery; and
(B) When the light-controlling layer is colored or decolored, a voltage is applied to the first electrode and the second electrode based on the discharge of the capacitor;
A dimmer device that controls the light.
[A02] The control unit further includes:
(C) applying a voltage to the first electrode and the second electrode based on the secondary battery after a predetermined time has elapsed since the start of coloring or decoloring of the light-adjusting layer;
The light control device according to [A01],
[A03] A dimming device as described in [A02], in which after a predetermined time has elapsed since the start of coloring of the dimming layer, a voltage based on a secondary battery is applied to the first electrode and the second electrode, and after a specified time (coloring/specified time) has elapsed, the application of voltage based on the secondary battery to the first electrode and the second electrode is discontinued.
[A04] A dimming device described in [A02] or [A03], in which a voltage is applied to the first electrode and the second electrode based on a secondary battery after a predetermined time has elapsed since the start of decolorization of the dimming layer, and the application of the voltage to the first electrode and the second electrode based on the secondary battery is stopped after a specified time (decolorization/specified time) has elapsed.
[A05] The light control device according to [A02] or [A03], wherein application of voltage to the first electrode and the second electrode based on the secondary battery is stopped after a predetermined time has elapsed since the start of decolorization of the light control layer.
[A06] The control unit applies a positive potential to one of the first electrode and the second electrode and applies a negative potential to the other of the first electrode and the second electrode when coloring the light control device;
The light control device according to any one of [A01] to [A05], wherein, when the light control device is decolorized, the control unit applies to the first electrode and the second electrode a voltage having a polarity opposite to that when the light control device is colored.
[A07] When the charge amount that gives the desired light transmittance to the photochromic layer during coloring is _Q0 , the charge amount of the capacitor after charging is _Q1 , and the charge amount of the capacitor after a predetermined time _T0 has elapsed from the start of coloring or decoloring of the photochromic layer is _Q2 ,
0.4<(Q ₁ -Q ₂ )/Q ₀
The light control device according to any one of [A01] to [A06], wherein the control unit controls the capacitor and the voltages applied to the first electrode and the second electrode so as to satisfy the above.
[A08] 1.0≦(Q ₁ -Q ₂ )/Q ₀ ≦10.0
The light control device according to [A07], wherein the control unit controls the capacitor and the voltages applied to the first electrode and the second electrode so as to satisfy the above.
[A09] 0.1 (seconds) ≦T ₀ ≦12 (seconds)
The light control device according to [A07] or [A08], which satisfies the above.
[A10] The light control device according to any one of [A01] to [A09], in which a current flows through the light control layer when a voltage is applied to the first electrode and the second electrode.
[B01] The light control device according to any one of [A01] to [A10], wherein the light control layer has a laminated structure of a reduction coloring layer made of tungsten oxide, an electrolyte layer made of tantalum oxide, and an oxidation coloring layer containing iridium atoms.
[B02] The light control device according to [B01], wherein the oxidized coloring layer is made of an iridium tin oxide-based material.
[B03] The light control device according to [B01] or [B02], wherein a moisture retaining member is disposed at least between the second electrode and the second substrate.
[B04] The light control device according to [B03], wherein an end face of the moisture retaining member is exposed to the outside.
[B05] Further comprising a sealing member provided on an edge portion of the first substrate,
The light control device according to [B04], wherein a moisture retention member extension portion extending from the moisture retention member is disposed between the sealing member and the second substrate.
[B06] The second electrode is formed on the light-adjusting layer and on the first substrate, and is spaced apart from the first electrode;
The light-adjusting device according to [B05], wherein the moisture-retaining member covers at least the second electrode and the light-adjusting layer.
[B07] The light control device according to [B05] or [B06], wherein a part of the sealing member is made of an auxiliary electrode.
[B08] The auxiliary electrode is composed of a first auxiliary electrode formed on the first electrode, and a second auxiliary electrode formed on the second electrode at a distance from the first auxiliary electrode.
[B09] The light control device according to [B05] or [B06], wherein the sealing member is made of resin.
[B10] The light control device according to [B09], wherein the Young's modulus of the resin constituting the sealing member is 1×10 ⁷ Pa or less.
[B11] The light control device according to [B05] or [B06], in which an auxiliary electrode is provided on the inside of at least a part of the sealing member.
[B12] The auxiliary electrode is composed of a first auxiliary electrode formed on the first electrode, and a second auxiliary electrode formed on the second electrode at a distance from the first auxiliary electrode.
[B13] The light control device according to [B05] or [B06], wherein the sealing member is made of a convex portion provided on the edge portion of the first substrate.
[B14] The light control device according to [B13], in which an auxiliary electrode is provided on the inner side of a part of the sealing member.
[B15] The auxiliary electrode is composed of a first auxiliary electrode formed on the first electrode, and a second auxiliary electrode formed on the second electrode at a distance from the first auxiliary electrode.
[B16] The light control device according to any one of [B05] to [B15], wherein the cross-sectional shape of the sealing member becomes narrower toward the second substrate.
[B17] The light control device according to any one of [B03] to [B16], wherein an inorganic material film is formed on the surface of the second substrate facing the moisture retaining member.
[B18] The light control device according to any one of [B03] to [B17], wherein the Young's modulus of the material constituting the moisture retaining member is 1×10 ⁶ Pa or less.
[B19] The light control device according to [B18], wherein the resin constituting the moisture retaining member is an acrylic resin, a silicone resin or a urethane resin.
[C01] The dimmer device is
a transparent first substrate and a transparent second substrate facing the first substrate;
A first electrode provided on a first substrate;
A second electrode provided on the second substrate; and
an electrolyte containing metal ions sealed between the first substrate and the second substrate;
It consists of
The first electrode is made of a thin wire of a conductive material,
The display device according to any one of [A01] to [A10], wherein the second electrode is composed of a transparent electrode layer.
[C02] The display device according to [C01], wherein the first substrate is disposed closer to the viewer than the second substrate.
[C03] The display device according to [C02], wherein the first electrode is made of a nanowire.
[C04] The display device according to [C03], wherein the average diameter of the nanowires is 1 μm or less.
[C05] The display device according to any one of [C01] to [C04], wherein the first electrode is made of silver.
[C06] The display device according to any one of [C01] to [C05], wherein the second electrode is not patterned within the effective area of the light control device.
[C07] The metal ion is a silver ion;
The display device according to any one of [C01] to [C06], wherein the electrolyte contains at least one salt selected from the group consisting of LiX, NaX, and KX (wherein X is a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom).
[C08] A display device described in any one of [C01] to [C07], in which coloring and decoloring of the dimming device occur due to deposition of metal on the second electrode and dissolution of metal into the electrolyte based on application of a voltage to the first electrode and the second electrode.
[D01] When the effective area of the light-controlling layer is A (mm ² ) and the capacitance of the capacitor is C (farads),
C/A>1×10 ^-6 (F/mm ² )
The light control device according to any one of [A01] to [C08], which satisfies the above.
[D02] The light control device according to any one of [A01] to [D01], wherein the capacitor is composed of a plurality of capacitors connected in parallel.
[D03] The control circuit includes:
A current limiting circuit that limits the current when discharging the secondary battery; and
a voltage control circuit that controls the voltages applied from the capacitor and the secondary battery to the first electrode and the second electrode;
The light control device according to any one of [A01] to [D02],
[D04] The light control device according to any one of [A01] to [D03], wherein the secondary battery is a lithium ion battery.
[D05] Further comprising an illuminance sensor (environmental illuminance measurement sensor) for measuring the illuminance of the environment in which the display device is placed,
The display device according to any one of [A01] to [D04], which controls the light transmittance of the dimming device based on the measurement result of an illuminance sensor (ambient illuminance measuring sensor).
[D06] Further comprising an illuminance sensor (environmental illuminance measurement sensor) for measuring the illuminance of the environment in which the display device is placed,
The display device according to any one of [A01] to [D05], which controls the brightness of an image formed by an image forming device based on the measurement result of an illuminance sensor (ambient illuminance measuring sensor).
[D07] Further comprising a second illuminance sensor (transmitted light illuminance measuring sensor) that measures illuminance based on light transmitted through the dimmer from the external environment,
The display device according to any one of [A01] to [D06], wherein the light transmittance of the dimming device is controlled based on the measurement result of the second illuminance sensor (transmitted light illuminance measuring sensor).
[D08] Further comprising a second illuminance sensor (transmitted light illuminance measuring sensor) that measures illuminance based on light transmitted through the dimmer from the external environment,
The display device according to any one of [A01] to [D07], wherein the brightness of an image formed by an image forming device is controlled based on a measurement result of a second illuminance sensor (a transmitted light illuminance measuring sensor).
[D09] The display device according to [D07] or [D08], wherein the second illuminance sensor (transmitted light illuminance measuring sensor) is disposed closer to the viewer than the optical device.
[D10] A display device described in any one of [D05] to [D09], in which when the measurement result of the illuminance sensor (ambient illuminance measurement sensor) becomes a predetermined value or more, the light transmittance of the dimming device is set to a predetermined value or less.
[D11] A display device described in any one of [D05] to [D09], which sets the light transmittance of the dimming device to a predetermined value or more when the measurement result of the illuminance sensor (ambient illuminance measurement sensor) becomes a predetermined value or less.
[D12] A display device described in [D07] or [D08], in which when the measurement result of the second illuminance sensor (transmitted light illuminance measurement sensor) becomes a predetermined value or more, the light transmittance of the dimming device is set to a predetermined value or less.
[D13] A display device described in [D07] or [D08], in which when the measurement result of the second illuminance sensor (transmitted light illuminance measurement sensor) becomes a predetermined value or less, the light transmittance of the dimming device is set to a predetermined value or more.
[D14] The display device according to any one of [A01] to [D13], wherein the maximum light transmittance of the dimming device is 50% or more and the minimum light transmittance of the dimming device is 30% or less.
[D15] The light control device according to any one of [A01] to [D14], which is curved.
[D16] A dimming device according to any one of [A01] to [D15], wherein the first substrate and the second substrate are made of a plastic material.
[E01] <<Image display device>>
Image forming apparatus,
An optical device having a virtual image forming area in which a virtual image is formed based on light emitted from an image forming device;
a light control device that is disposed opposite at least the virtual image formation area and adjusts the amount of external light incident from the outside;
It is equipped with
The light control device is an image display device including the light control device according to any one of [A01] to [D16].
[E02]《Display device》
A frame to be worn on the observer's head; and
an image display device attached to a frame;
A display device comprising:
The image display device includes:
Image forming apparatus,
An optical device having a virtual image forming area in which a virtual image is formed based on light emitted from an image forming device;
a light control device that is disposed opposite at least the virtual image formation area and adjusts the amount of external light incident from the outside;
It is equipped with
The light control device is a display device comprising the light control device according to any one of [A01] to [D16].

LIST OF SYMBOLS 10: Frame, 10': Nose pad section, 11: Front section, 11': Rim, 12: Hinge, 13: Temple section, 14: End piece section, 15: Wiring (signal line, power line, etc.), 16: Headphone section, 16': Wiring for headphone section, 17: Camera, 18: Control device, 19: Mounting member, 20: Observer, 21: Eye, 30: Control section, 31: Secondary battery, 32: Control circuit, 32A: Secondary battery control section, 33: Capacitor, 41: First switch section, _SW1 , _SW2 , SW ₂ : Switch section, 42: Second switch section, 50: Voltage control circuit (regulator), 60: Charging circuit, 61: Comparator, 62: Constant voltage IC with current limiting function (constant voltage IC), 70A, 70B: Light transmittance/polarity control circuit, 71A, 71B: Operational amplifier, 100, 200, 300, 400, 500: Image display device, 111, 111A, 111B, 111', 211, 211A, 211B: Image forming device, 112: Optical system (collimated optical system), 113, 213: Housing, 120, 320, 5 20: Optical device, 121, 321: Light guide plate, 122, 322: First surface of light guide plate, 123, 323: Second surface of light guide plate, 124, 125: Part of light guide plate, 130: First deflection means, 140: Second deflection means (virtual image forming region), 330: First deflection means (first diffraction grating member), 330A, 340A: Reflective diffraction grating element, 340: Second deflection means (second diffraction grating member, virtual image forming region), 330B, 340B: Transmissive diffraction grating element, 351: First reflective volume hologram diffraction grating, 352: Second Reflection type volume hologram diffraction grating, 353... third reflection type volume hologram diffraction grating, 150... reflection type spatial light modulation device, 150'... organic EL display device, 151... liquid crystal display device (LCD), 152... polarizing beam splitter (PBS), 153... light source, 251, 251A, 251B... light source, 252... collimating optical system, 253... scanning means, 254... optical system (relay optical system), 256... total reflection mirror, 530A, 530B... semi-transmitting mirror, 601... light source, 602... light guiding member, 603, 6 05: Polarizing beam splitter, 604: Liquid crystal display device, 606: 1/4 wavelength plate, 607: Reflector, 611: Image forming device, 612: Light guide member 612, 613: Semi-transmissive mirror, 614: Reflector, 621: Image forming device, 622: Prism, 623, 624: Prism surface, 625: Convex lens, 700, 700': Light control device, 701: Virtual image forming area facing area, 711A: First substrate, 711B: Second substrate, 712A: First electrode, 712B: Second electrode, 713: _WO3 layer (reduced coloring layer), 714: _Ta2O5 layer ₍ electrolyte layer), 715: _{IrXSn1 -X} O layer (oxidation coloring layer), 716... light control layer, 719A... protective layer, 719B... underlayer, 719C... sealant, 719D... adhesive, 721... moisture retention member, 722... moisture retention member extension, 723... sealing member, 800... light control device, 801... first substrate, 802... first electrode, 803... second substrate, 804... second electrode, 805... electrolyte, 806... sealant, 901... illuminance sensor (ambient illuminance measurement sensor), 902... second illuminance sensor (transmitted light illuminance measurement sensor), 903... light shielding portion material, 1001...cell (battery pack), 1002...magnesium secondary battery, 1010...control unit, 1011...memory, 1012...voltage measurement unit, 1013...current measurement unit, 1014...current detection resistor, 1015...temperature measurement unit, 1016...temperature detection element, 1020...switch control unit, 1021...switch unit, 1022...charge control switch, 1024...discharge control switch, 1023, 1025...diode, 1031...positive terminal, 1032...negative terminal, CO, DO...control signal

Claims (16)

A first electrode,
a second electrode facing the first electrode;
a light-controlling layer sandwiched between a first electrode and a second electrode;
A first substrate,
a protective layer formed between the first electrode and the first substrate; and
A control unit for controlling coloring and decoloring of the light-controlling layer;
Equipped with
The control unit includes a secondary battery, a control circuit, and a capacitor.
The control unit
(A) charging a capacitor with a secondary battery; and
(B) When the light-controlling layer is colored or decolored, a voltage is applied to the first electrode and the second electrode based on the discharge of the capacitor;
A dimmer device that controls the light. The control unit further includes:
(C) applying a voltage to the first electrode and the second electrode based on the secondary battery after a predetermined time has elapsed since the start of coloring or decoloring of the light-adjusting layer;
The light control device according to claim 1 . the control unit applies a positive potential to one of the first electrode and the second electrode and applies a negative potential to the other of the first electrode and the second electrode when the light control device is colored;
The light control device according to claim 1 , wherein, when the light control device is in a bleached state, the control unit applies to the first electrode and the second electrode a voltage having a polarity opposite to that when the light control device is in a colored state. When the charge amount that gives the desired light transmittance to the light-controlling layer during coloring is _Q0 , the charge amount of the capacitor is _Q1 , and the charge amount of the capacitor after a predetermined time _T0 has elapsed from the start of coloring or decoloring of the light-controlling layer is _Q2 ,
0.4<(Q ₁ -Q ₂ )/Q ₀
The light control device according to claim 1 , wherein the control unit controls the capacitor and the voltages applied to the first electrode and the second electrode so as to satisfy the following: 1.0≦(Q ₁ -Q ₂ )/Q ₀ ≦10.0
The light control device according to claim 4 , wherein the control unit controls the capacitor and the voltages applied to the first electrode and the second electrode so as to satisfy the following: 0.1 (seconds) ≦T ₀ ≦12 (seconds)
The light control device according to claim 4, which satisfies the above. The light control device according to claim 1, in which a current flows through the light control layer when a voltage is applied to the first electrode and the second electrode. The light control device according to claim 1, wherein the light control layer has a laminated structure of a reduction coloring layer made of tungsten oxide, an electrolyte layer made of tantalum oxide, and an oxidation coloring layer containing iridium atoms. The light control device according to claim 8, wherein the oxide coloring layer is made of an iridium tin oxide-based material. The light control device according to claim 1, wherein a moisture-retaining member is disposed at least between the second electrode and the second substrate. When the effective area of the light-controlling layer is A (mm ² ) and the capacitance of the capacitor is C (farads),
C/A>1×10 ^-6 (F/mm ² )
The light control device according to claim 1 , which satisfies the above. The dimmer device according to claim 1, wherein the capacitor is composed of multiple capacitors connected in parallel. The control circuit includes:
A current limiting circuit that limits the current when discharging the secondary battery; and
a voltage control circuit that controls the voltages applied from the capacitor and the secondary battery to the first electrode and the second electrode;
The light control device according to claim 1 . The light control device according to claim 1, wherein the secondary battery is a lithium ion battery. Image forming apparatus,
An optical device having a virtual image forming area in which a virtual image is formed based on light emitted from an image forming device;
a light control device that is disposed opposite at least the virtual image formation area and adjusts the amount of external light incident from the outside;
Equipped with
The image display device comprises a light control device according to any one of claims 1 to 14. A frame to be worn on the observer's head; and
an image display device attached to a frame;
A display device comprising:
The image display device includes:
Image forming apparatus,
An optical device having a virtual image forming area in which a virtual image is formed based on light emitted from an image forming device;
a light control device that is disposed opposite at least the virtual image forming area and adjusts the amount of external light incident from the outside;
It is equipped with
A display device comprising the light control device according to any one of claims 1 to 14.

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