JPH09179075A - Light control eyeglasses - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide easy-to-see eyeglasses to changes in external light by controlling a transmissivity by means of varying a driving voltage of a liquid crystal panel when a change in a light quantity of external light is detected for longer than a fixed time. SOLUTION: A control part is composed of a solar battery 4 to supply a voltage for a driving voltage of a liquid crystal panel 2 and each part of circuits, a photosensor 5 to detect a light quantity of the external light, and a driving circuit 6 to control a transmissivity of the liquid crystal panel 2. The transmissivity of the liquid crystal panel 2 is controlled according to the brightness of the external environment by detecting the brightness of the external light by a photosensor 5 and controlling the driving voltage of the liquid crystal panel 2 according to the detected brightness. Thus, in the strong sunlight, the driving voltage is raised to block off the light and reduce the transmissivity of the liquid crystal panel 2, while, in the week sunlight, the driving voltage is lowered to increase the transmissivity of the liquid crystal panel 2, and thus, an visivility is improved by allowing more light to enter the eyes through the light control eyeglasses.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to glasses having a light control function.

[0002]

2. Description of the Related Art Sunlight in midsummer is strong in sunlight, and many people use sunglasses to avoid sunlight. In addition, many foreigners are vulnerable to ultraviolet rays, so many people wear sunglasses. You can protect your eyes from strong sunlight by using sunglasses. However, since the conventional sunglasses cannot change the transmittance of external light, they are useful when the sunlight is strong, but they are difficult to see in the shade or indoors.
Therefore, the sunglasses are to be removed according to the brightness of the external environment, but there is a problem that a person who has sunglasses with weak eyesight and a degree of eyesight cannot remove the sunglasses, which makes it rather difficult to see.

Therefore, dimming glasses having a dimming function using a liquid crystal panel have been considered.

[0004]

By the way, when a dimming function is realized by using a liquid crystal, when the amount of external light changes in a short time, the liquid crystal repeats a transmission state and a light blocking state at short time intervals, On the contrary, it may be difficult to see.

Further, in order to incorporate the liquid crystal panel into the frame of the glasses, it is necessary to bend the liquid crystal panel according to the shape of the frame, and at that time, the spacer inserted between the glass substrates moves and the gap changes. There is a problem of doing.

Further, in the liquid crystal panel, as shown in FIG. 10, a liquid crystal 19 is enclosed between two glass substrates 11 and 15, a front polarizing plate 12 is attached on the front glass substrate 11, and a back surface side is attached. The rear polarizing plate 16 is used by pasting it on the glass substrate 15. Therefore, there is a problem in that the front polarizing plate 12 or the rear polarizing plate 16 absorbs ultraviolet rays or infrared rays to generate heat, and the temperature of the liquid crystal panel rises to exceed the operation allowable temperature.

An object of the present invention is to provide dimming glasses that are easy to see even if the external light changes. Another object is to provide dimming glasses in which the gap does not change even when the liquid crystal panel is bent. Furthermore, another problem is to suppress the temperature rise of the liquid crystal panel due to ultraviolet rays or the like.

[0008]

The light control glasses of the first invention include a liquid crystal panel including two transparent substrates and a liquid crystal layer,
An optical sensor that detects the amount of external light and a voltage control unit that controls the light transmittance by changing the drive voltage of the liquid crystal panel when the change in the amount of external light is detected by the optical sensor for a certain period of time or more. Prepare

According to the first aspect of the invention, the transmittance of the liquid crystal panel is changed when the amount of external light continuously changes for a certain period of time or more. Therefore, the transmittance of the light control glasses frequently changes. Can be prevented from becoming difficult to see.

The dimming glasses of the second invention are a liquid crystal panel comprising two liquid crystal layers and two transparent substrates having heat fusion spacers fused to each other, an optical sensor for detecting the amount of external light, and an optical sensor. Voltage control means for controlling the drive voltage applied to the liquid crystal panel according to the amount of light detected in.

In the second aspect of the present invention, the two transparent substrates are fused by the heat fusion spacer so that the gap between the transparent substrates does not change even when the liquid crystal panel is bent when the liquid crystal panel is incorporated into the frame of the glasses. You can

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of sunglasses according to an embodiment of the present invention. This sunglasses has a frame 1
Provided in the central part of the liquid crystal panel 2 and the frame 1,
The control unit 3 controls the amount of transmitted light of the liquid crystal panel 2. It should be noted that the sunglasses having a brown or gray color tone can be realized by using a polarizing material that makes the two polarizing plates of the liquid crystal panel 2 have a brown or gray color tone in the crossed Nicols state. Further, in order to adjust the color intensity of the light-shielded state, it is possible to control the degree of polarization of the polarizing plate material used. Further, in order to obtain a light-shielding color of brown, the product of the liquid crystal layer thickness d and the birefringence Δn of the liquid crystal material d ·
The value of Δn may be set to be about 0.2 to 0.6.

The control unit 3, as shown in FIG. 2, is a solar cell 4 that supplies a drive voltage of the liquid crystal panel 2 and a voltage to each circuit section.
And a drive circuit 6 for controlling the transmittance of the liquid crystal panel 2, and an optical sensor 5 for detecting the amount of external light. The drive circuit 6 outputs a drive voltage for making the left liquid crystal panel 2a and the right liquid crystal panel 2b transparent or light-shielded.

In a positive type liquid crystal which transmits light when a drive voltage is not applied, the relationship between the light transmittance of the liquid crystal and the drive voltage has the characteristics shown in FIG. That is, when the drive voltage is V0, the transmittance of the liquid crystal becomes the maximum value T0. When the driving voltage V1 is higher than that, the transmittance is T1, and when the driving voltage V2 is higher, the transmittance is the lowest value T2.

Therefore, the light sensor 5 detects the brightness of the external light, and the drive voltage of the liquid crystal panel 2 is changed according to the detected brightness, so that the light transmittance of the liquid crystal panel 2 is adjusted to the brightness of the external environment. Can be controlled accordingly. Thus, when the sunshine is strong, the drive voltage is increased to bring the liquid crystal panel 2 into the T1 to T2 state to block outside light, and when the sunshine is weak, the drive voltage is lowered to move the liquid crystal panel 2 to T0.
In the T1 state, a large amount of light can enter the eyes through the light control glasses to improve the visibility.

Next, the structure of the liquid crystal panel 2 will be described with reference to FIG. A polarizing plate 12 is provided on the surface of the upper glass substrate 11 on which external light is incident, and a transparent electrode 13 is formed on the lower surface of the upper glass substrate 11. Further, an alignment film 14 is formed below the transparent electrode 13.

A polarizing plate 16 is provided below the lower glass substrate 15 facing the upper glass substrate 11, a transparent electrode 17 is formed on the upper surface of the lower glass substrate 15, and an alignment film 18 is further provided thereon. Has been formed.

Upper glass substrate 11 and lower glass substrate 15
A liquid crystal 19 is enclosed between and, and the periphery of the two glass substrates is covered with a seal 23. Further, a plastic spacer 21 for ensuring a constant gap between the glass substrates 11 and 15 and upper and lower glass substrates 11 and 15 so as to ensure a constant gap even when the liquid crystal panel 2 is bent. Thermally fused spacer 2 fused
0 and are inserted. The heat fusion spacer 20 is made of, for example, an epoxy fusion spacer and includes two glass substrates 1
After the plastic spacer 21 and the heat fusion spacer 20 are sandwiched between the first and the second fifteen, the liquid crystal panel 2 is heated to fuse the heat fusion spacer 20 to the upper and lower glass substrates 11 and 15. This prevents the liquid crystal panel 3 from being curved and the spacers moving to change the thickness of the liquid crystal layer when the liquid crystal panel 3 is incorporated into the frame of the light control glasses. A film or plastic may be used instead of the glass substrate.

FIG. 5 is a diagram showing the electrode structure of the liquid crystal panel 2 of this embodiment. The outer dimensions of the lower glass substrate 15 are
It is larger than the outer dimensions of the upper glass substrate 11,
The transparent electrode of the upper glass substrate 11 is electrically connected to the terminal of the lower glass substrate 15, and the terminal of the transparent electrode of the upper glass substrate 11 is taken out from the lower glass substrate 15.

The transparent electrode for display of the upper glass substrate 11 is formed in the region shown by the broken line in FIG. 5, and the common electrode and the segment electrode are electrically connected to the terminals 32 formed on the lower glass substrate 15 by the silver paste 31. However, it can be electrically connected to the drive circuit 6.

The transparent electrode of the lower glass substrate 15 is formed in the region shown by the alternate long and short dash line in FIG. 5, the common electrode and the segment electrode are connected to the terminal 33, and the drive circuit 6
It can be electrically connected to.

Next, referring to FIGS. 6 (A), 6 (B) and 7, a second embodiment of the present invention for preventing the temperature rise of the liquid crystal panel 2 due to ultraviolet rays, infrared rays, etc. incident from the outside will be described. And explain.

As described in the conventional example, the polarizing plate 12 on the surface of the liquid crystal panel 2 absorbs external light to generate heat and the temperature inside the liquid crystal panel 2 rises. Therefore, there is a problem that when the sunshine is strong in the midsummer, the internal temperature of the liquid crystal panel 2 exceeds the operation allowable temperature, and the liquid crystal panel 2 cannot function as the light control glasses.

In FIG. 6A, a cut sheet 51 for ultraviolet rays and infrared rays is attached to the polarizing plate 12 via a spacer 52, and the ultraviolet rays and infrared rays are cut to suppress heat generation of the polarizing plate 12. . In this case, since the spacer 52 is provided between the ultraviolet / infrared cut sheet 51 and the polarizing plate 12, the cut sheet 51 generates heat by the polarizing plate 12.
Does not affect, and the polarizing plate 12 itself does not generate heat. As a result, the temperature rise of the liquid crystal panel 2 can be suppressed even under strong sunlight such as midsummer.

Further, FIG. 3B shows that a reflection sheet for ultraviolet rays and infrared rays is attached on the polarizing plate 12 and the ultraviolet rays or infrared rays are reflected to suppress the heat generation of the polarizing plate 12. Further, in FIG. 7, a spacer 54 is provided between the polarizing plate 12 and the glass substrate 11 to release the heat generated by the polarizing plate 12 to the outside to suppress the temperature rise of the liquid crystal panel 2.

Next, a method for realizing appropriate light control when the amount of external light changes regularly or irregularly will be described. When the amount of outside light changes regularly or irregularly, if the transmittance of the liquid crystal panel 2 is changed according to the change of the amount of light, the transmittance of the light control glasses may be changed due to the change of ambient brightness. It changes rapidly and becomes difficult to see.

Therefore, the above-mentioned problem can be solved by changing the transmittance of the liquid crystal panel 2 when the change of the amount of the external light continues for a certain time or more. FIG. 8 is a diagram showing a light-dark state when light is blocked by a house along a road or an obstacle such as a tree when the vehicle is traveling and the brightness changes.

In the figure, light is blocked by the obstacle for 4 seconds in the section B-C, and then the section C-D remains bright for 6 seconds without any obstacle. Further, in the next section D-E, the light is blocked again by the obstacle for 6 seconds, and the dark state continues.

When the above-mentioned bright and dark states are repeated, the time (non-dimming time) from the change in the light amount detected by the optical sensor 5 to the actual change in the transmittance of the liquid crystal panel 2 is 3 seconds. The bright and dark states of the liquid crystal panel 2 in each section when set to 1 and when set to 1 second will be described with reference to FIG.

First, the case where the non-dimming time is set to 3 seconds will be described. In this case, in the section A-B shown in FIG. 9 (1), since there is no obstacle, the external light is in a bright state, and the drive voltage is supplied from the drive circuit 6 to the liquid crystal panel 2. When the driving voltage is applied, the transmittance of the liquid crystal panel 2 becomes low, and the liquid crystal panel 2 becomes dark. In this state, external light is attenuated by the light control glasses and reaches the eyes.

Next, in the section B-C shown in FIG. 2B, the light is blocked by the obstacle for 4 seconds. When it is determined that the amount of external light detected by the optical sensor 5 is in the dark state for 3 seconds or more, the drive circuit 6 switches the drive voltage from the on state to the off state. As a result, the transmittance of the liquid crystal panel 2 is increased, and the liquid crystal panel 2 is in the bright state (transmissive state). In this state, the outside light reaches the eye without being attenuated by the light control glasses.

Next, in the section C-D shown in FIG. 3C, the obstacle disappears again, and the optical sensor 5 detects that the external light is in the bright state for 3 seconds or more. The drive voltage is switched from off to on. When the driving voltage is supplied to the liquid crystal panel 2, the transmittance of the liquid crystal panel 2 becomes low, and the liquid crystal panel 2 becomes in the dark state (light-shielding state). In this state, external light is attenuated by the light control glasses and reaches the eyes.

Next, in the section D-E shown in FIG. 4 (4), if the obstacle blocks the light for 6 seconds and it is determined that the amount of outside light is dark for 3 seconds or more, the drive circuit 6 The nigiri drive voltage is switched from the on state to the off state. When the drive voltage is turned off, the transmittance of the liquid crystal panel 2 is increased and the liquid crystal panel 2 is in a bright state.

Next, in the section E-F shown in FIG. 5 (5), there is no obstacle and it becomes bright, but since the period is 2 seconds, the drive voltage output from the drive circuit 6 remains off. It does not change and the transmittance of the liquid crystal panel 2 maintains the same high state as in the section D-E immediately before that. In this state, the outside light reaches the eye without being attenuated by the light control glasses.

That is, even if the external light changes from the dark state to the bright state, or vice versa, if the state does not last for 3 seconds or more, the transmittance of the light control glasses changes. It is supposed not to. Therefore, when the brightness of outside light changes from a bright state to a dark state or from a dark state to a bright state in a short time, it is possible to prevent the transmittance of the light control glasses from changing at a short time interval and causing an eyesore. it can.

Similarly, in the H-I section shown in FIG. 6 (6), the bright state until then changes from the bright state to the dark state due to an obstacle, but since the period is 2 seconds, the output from the drive circuit 6 is output. The drive voltage applied remains unchanged in the ON state, and the transmittance of the liquid crystal panel 2 remains low.

Similarly, in the JK period shown in FIG. 7 (7), the bright state changes to the dark state due to an obstacle, but since the period is 2 seconds, the drive voltage output from the drive circuit 6 is It remains in the ON state and does not change, and the transmittance of the liquid crystal panel 2 remains low.

Further, the LM section shown in FIG. 8 (8) also changes from a bright state to a dark state due to an obstacle, but since the period is short, the drive voltage output from the drive circuit 6 remains in the ON state. Become.

On the other hand, when the non-dimming time until the start of dimming is set to 1 second, H- shown in FIG. 9 (6)
In the section I, the brightness of the external environment changes from the bright state to the dark state due to the obstacle, and the state continues for 2 seconds. Therefore, the drive voltage output from the drive circuit 6 changes from the on state to the off state. As a result, the transmittance of the liquid crystal panel 2 is increased and the liquid crystal panel 2 is brought into a bright state. In this state, the outside light reaches the eye without being attenuated by the light control glasses.

In the next section I-J, the obstacle disappears and the dark state changes to the bright state, and this state continues for 4 seconds. Therefore, the drive voltage output from the drive circuit 6 changes from the off state to the on state. When the drive voltage is turned on, the transmittance of the liquid crystal panel 2 becomes low, and the liquid crystal panel 2 becomes dark.
In this state, external light is attenuated by the light control glasses and reaches the eyes.

Then, in the next JK section shown in FIG. 7 (7), the bright state is changed to the dark state due to an obstacle and the state continues for 2 seconds, so that the driving voltage output from the driving circuit 6 is turned on. The state changes to the off state. When the drive voltage is turned off, the transmittance of the liquid crystal panel 2 is increased and the liquid crystal panel 2 is in a bright state. In this state, the outside light reaches the eye without being attenuated by the light control glasses.

Similarly, in the next section K-L, since there is no obstacle, the drive voltage output from the drive circuit 6 is turned on, and the transmittance of the liquid crystal panel 2 becomes low. The state changes to a dark state. And the next L
Since there is an obstacle in the −M section, the drive voltage output from the drive circuit 6 is turned off, the transmittance of the liquid crystal panel 2 is increased, and the liquid crystal panel 2 is in a bright state.

As described above, when the transmittance of the liquid crystal panel 2 is changed when the change in the brightness of the external light continues for 1 second or more, the transmittance of the liquid crystal panel 2 is frequently changed and becomes difficult to see. On the other hand, if the transmittance of the liquid crystal panel 2 is changed when the change in brightness continues for 3 seconds or more, the change in the transmittance of the liquid crystal panel 2 is not so much noticed, and the level is not a problem in practical use. Become.

In the above embodiments, the case of using the positive type liquid crystal has been described, but the negative type liquid crystal may be used. Further, the liquid crystal panel is not limited to the TN type liquid crystal, but S
It is also possible to use TN liquid crystal, phase transition liquid crystal, ferroelectric liquid crystal, or the like.

Further, the liquid crystal panel 2 may be formed integrally with the frame 1, or the liquid crystal panel 2 may be formed integrally with the control unit 3 so as to be detachable from the glasses.
Further, in the above-described embodiment, the liquid crystal panel 2 is turned on and off by the light amount detected by the optical sensor 5, but the transmittance of the liquid crystal panel 2 is controlled according to the light amount detected by the optical sensor 5. The light may be attenuated in multiple stages.

[0046]

According to the present invention, the transmittance of the liquid crystal panel is changed only when the change in the brightness of the external light continues for a certain time or longer, so that the dimming is easy to see even when the brightness changes in a short time. Can realize glasses. Further, since the two transparent substrates are fused by using the heat fusion spacer,
Even when the liquid crystal panel is bent when the liquid crystal panel is attached to the frame of the glasses, the gap of the liquid crystal panel can be prevented from changing.

[Brief description of the drawings]

FIG. 1 is an external view of light control glasses of an embodiment.

FIG. 2 is a circuit block diagram of light control glasses.

FIG. 3 is a diagram showing a voltage-transmittance characteristic of the liquid crystal panel 2.

FIG. 4 is a schematic sectional view of a liquid crystal panel 2.

FIG. 5 is a diagram showing an electrode structure of a glass substrate.

FIG. 6 (A) is a cross-sectional view of a liquid crystal panel 2 using ultraviolet and infrared cut sheets, and FIG. 6 (B) is
It is sectional drawing of the liquid crystal panel 2 which used the ultraviolet-ray and infrared reflection sheet.

FIG. 7 is a cross-sectional view of the liquid crystal panel 2 in which a spacer is provided between the polarizing plate 12 and the glass substrate 11.

FIG. 8 is a diagram showing a bright and dark state due to an obstacle.

FIG. 9 is a diagram showing a light / dark state of a liquid crystal panel in each section when a non-dimming time is set.

FIG. 10 is a cross-sectional view of a conventional liquid crystal panel.

[Explanation of symbols]

 2 liquid crystal panel 3 control unit 4 solar cell 5 optical sensor 6 drive circuit

Claims (7)

[Claims] 1. A liquid crystal panel comprising two transparent substrates and a liquid crystal layer, an optical sensor for detecting the amount of external light, and a change in the amount of external light detected by the optical sensor for a predetermined time or more, A dimming spectacles, comprising: voltage control means for controlling a light transmittance by changing a driving voltage of the liquid crystal panel. 2. A liquid crystal panel composed of two transparent substrates and a liquid crystal layer fused by a heat fusion spacer, an optical sensor for detecting the amount of external light, and a light amount detected by the optical sensor. And a voltage control means for controlling a drive voltage applied to the liquid crystal panel. 3. The light control glasses according to claim 1, wherein the liquid crystal panel has a polarizing plate, and a member for reflecting or absorbing ultraviolet rays and infrared rays is provided on the polarizing plate. 4. The light control glasses according to claim 1 or 2, wherein the liquid crystal panel, the optical sensor and the voltage control means are integrally formed and detachable from the frame of the glasses. 5. When the two transparent substrates are curved,
2. The light control glasses according to claim 1, wherein a heat fusion spacer for holding a gap between the transparent substrates is fused to the two transparent substrates. 6. The photochromic lens according to claim 1, wherein the optical sensor comprises a solar cell, and the drive voltage of the liquid crystal panel is controlled according to the output voltage of the solar cell. 7. The light control glasses according to claim 2, wherein the heat-sealing spacer is an epoxy-based heat-sealing spacer.