JPH05249458A - Liquid crystal optical element and projection type liquid crystal optical device formed by using the element - Google Patents

Abstract

PURPOSE:To provide multilayered dielectric films formed by laminating light transparent dielectric thin films varying in refractive indices as the reflection function layer provided between a rear electrode substrate and a solid matrix. CONSTITUTION:The light of a lamp 1 is condensed by a lens 2, is transmitted through a lens 3, is made incident on a liquid crystal optical element 4 of a reflection type, is reflected by the reflection function layer provided on the rear electrode substrate 15 side, is emitted to the incident side, is passed through and condensed by a lens 3 and is projected through a diaphragm 5 by a lens 6. The liquid crystal optical element 4 is constituted by clamping a solidified liquid crystal optical element composite formed by dispersing a nematic liquid crystal optical element into a solid matrix between a front electrode substrate 11 and the rear electrode substrate 15 and has an operation mode of a transmission scattering type. The rear electrode substrate 15 has a reflection function by a reflection film 17. This reflection film 17 is the multilayered dielectric films formed by laminating the light transparent dielectric thin film having a relatively high refractive index and the light transparent dielectric thin film having a relatively low refractive index.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type projection type liquid crystal optical device and a liquid crystal optical element used therein.

[0002]

2. Description of the Related Art As a liquid crystal optical element, a liquid crystal optical element using a DSM (dynamic scattering) type liquid crystal was originally proposed, but in the DSM type, a current value flowing in the liquid crystal is high, so that current consumption is high. It has the drawback of being large, and currently, TN (twisted nematic) type liquid crystal is mainly used, and it has appeared in the market as a pocket TV. The TN type liquid crystal has an extremely small leakage current and consumes less power, and is therefore suitable for applications using a battery as a power source. However, since the polarizing plate is used, there is a drawback that the display becomes dark.

Furthermore, in recent years, nematic liquid crystals have been dispersed and held in a solidified matrix, and the refractive index of the solidified matrix is almost the same as the refractive index of the liquid crystal used when a voltage is applied or not applied. Attention has been paid to a transmission / scattering type liquid crystal optical element formed by sandwiching a liquid crystal solidified composite thus prepared. This transmission / scattering type liquid crystal optical element has an advantage that bright display is possible because no polarizing plate is used. For this reason, particularly when used in a projection type optical device, a bright projected image can be obtained, and therefore, it is attracting attention.

[0004]

When this transmission / scattering type liquid crystal optical element is used as a reflection type element by forming a light reflection layer on one surface of the element, light travels back and forth through the modulation material layer as compared with the case of using it as a transmission type element. The action length is twice as long, and as a result, the element has high scattering ability at the time of scattering. Therefore, when this transmission / scattering type liquid crystal optical element is used as a reflection type optical device, a significant difference between the transmission state and the scattering state occurs, and high contrast display can be performed as compared with the case of the transmission type optical device.

Further, when an active element and a storage capacitor are formed for each pixel, the reflective type eliminates the reduction of the pixel aperture ratio due to the formation of the storage capacitor, and a higher aperture ratio can be obtained as compared with the transmissive type. In addition to being easy, the degree of freedom in designing active elements such as TFTs is generally increased.

However, when it is used as a reflection type element, the light reflecting layer formed on the back electrode substrate of the element is generally a metal film such as aluminum also serving as a pixel electrode. Such a metal film as a reflective electrode has a problem that it easily reacts with a base material and it is difficult to obtain a flat surface corresponding to an optical mirror surface. In particular, in the case of a TFT in which an insulating material such as SiN _x is used as the base, the flatness is significantly deteriorated.

As a result, there is a problem that the effective light reflectance is lowered due to the scattering of light due to the unevenness of the reflecting electrode. Further, there is a problem that the reflectance of a metal reflective film such as an aluminum electrode film is about 90% or less, and a portion less than 100% is absorbed by the reflective film and converted into heat, which deteriorates element characteristics. Further, the surface of the reflective electrode is likely to react with the liquid crystal layer to deteriorate the specific resistance of the liquid crystal layer or to reduce the reflectance of the reflective electrode.

Therefore, as a back electrode substrate having a reflection function of a reflection type transmission / scattering type liquid crystal optical element used in a projection type liquid crystal optical device, it has a flat surface as an optical reflecting mirror and little light absorption. High reflectance and stability over time have been required.

[0009]

The present invention has been made to solve the above problems, and provides a projection type liquid crystal optical device having a bright and high contrast ratio and a liquid crystal optical element used for the same.

That is, a nematic liquid crystal is dispersed and held in a solidified matrix between a front electrode substrate having a transparent electrode and a back electrode substrate, and the solidified substance is applied to the solidified matrix in either a state where a voltage is applied or a state where no voltage is applied. Between the back electrode substrate and the solidified matrix, there is a transmission-scattering type operation mode in which a liquid crystal solidified composite is sandwiched so that the refractive index of the matrix substantially matches the refractive index of the liquid crystal used. A liquid crystal optical element in which a reflective function layer is provided on the reflective function layer, the transmissive dielectric thin film having a relatively high refractive index and the transparent dielectric thin film having a relatively low refractive index are laminated. Provided is a liquid crystal optical element having a reflective film formed of the dielectric multilayer film.

In this liquid crystal optical element, the electrodes of the back electrode substrate are composed of divided pixel electrodes, and each pixel electrode is driven by an active element provided for each pixel.
Provided is a liquid crystal optical element characterized in that a light-shielding film is patterned and formed on the electrode surface side of a back electrode substrate or the electrode surface side of a front electrode substrate corresponding to the position of an active element.

Further, nematic liquid crystal is dispersed and held in a solidified matrix between a front electrode substrate having a transparent electrode and a back electrode substrate, and the solidified liquid crystal is maintained in a state where a voltage is applied or not applied. Between the back electrode substrate and the solidified matrix, there is a transmission-scattering type operation mode in which a liquid crystal solidified composite is sandwiched so that the refractive index of the matrix substantially matches the refractive index of the liquid crystal used. A liquid crystal optical element in which a reflective function layer is provided on the back electrode substrate, which is composed of divided pixel electrodes, each pixel electrode being driven by an active element provided for each pixel, A microlens array is arranged on the light incident side surface, and the optical axis of the light incident on the back electrode surface side is tilted by an angle θ from the vertical axis of the substrate surface. Light incident on one of the microlenses is condensed on the surface position of the pixel electrode, further reflected by the reflection function layer, and emitted to the other microlens. Provided is a liquid crystal optical element characterized in that arrangement with a lens, focal length of microlens, thickness of front electrode substrate and refractive index of front electrode substrate are selected.

Further, the reflective function film of the above-mentioned liquid crystal optical element with microlenses has wavelength selective reflectivity, and a reflective function layer is formed on the pixel electrode and the active element. Further, there is provided a liquid crystal optical element having a light-shielding film patterned on a position corresponding to an active element on the reflection function layer.

Furthermore, in a projection type liquid crystal optical device provided with a light source optical system, a liquid crystal optical element and a projection optical system, any one of the above liquid crystal optical elements is used, and the light from the light source optical system is on the front electrode substrate side. Incident on the inside of the liquid crystal optical element, reflected by the reflection function layer, and emitted from the front electrode substrate side,
Further provided is a projection type liquid crystal optical device characterized by being projected by a projection optical system.

Further, in this projection type liquid crystal optical device, the color separation optical system is provided between the light source optical system and the liquid crystal optical element, and the color separation light is incident on different liquid crystal optical elements,
There is provided a projection type liquid crystal optical device characterized in that at least one of the reflective functional layers of the plurality of liquid crystal optical elements has a wavelength selective reflection property that compensates for a decrease in color purity due to a color separation optical system.

Further, in these projection type liquid crystal optical devices, the reflection function layer of the liquid crystal optical element is formed by being divided into a plurality of portions having different wavelength selective reflection properties. I will provide a.

In the projection type liquid crystal optical device of the present invention, as the liquid crystal optical element to be used, a reflection type liquid crystal optical element sandwiching a liquid crystal solidified composite capable of electrically controlling the scattering state and the transmitting state is used. There is. Therefore, no polarizing plate is required, a bright light source can be used, and the transmittance of light at the time of transmission can be significantly improved. Furthermore, since the light reflectance of the electrode substrate on the front side is reduced, a high contrast ratio can be easily obtained.

Further, the liquid crystal optical element sandwiching the liquid crystal solidified composite is problematic in that the alignment process is essential for the reflective TN (twisted nematic) type liquid crystal optical device and the active element is destroyed by static electricity generated at that time. Since points are also avoided, the manufacturing yield of liquid crystal optical elements can be significantly improved.

Furthermore, since this liquid crystal solidified composite is in the form of a film after solidification, problems such as short-circuiting between substrates due to pressurization of substrates and destruction of active elements due to movement of spacers are unlikely to occur.

Further, this liquid crystal solidified composite has a specific resistance equivalent to that of the conventional TN mode, and it is not necessary to provide a large storage capacitance for each pixel electrode as in the DS (dynamic scattering) mode. The active element provided in each pixel electrode can be designed easily, and the power consumption of the liquid crystal optical element can be kept low. Therefore, the manufacturing process is easy because the manufacturing process of the conventional liquid crystal optical element of the TN mode can be performed by only removing the alignment film forming process.

The specific resistance of the liquid crystal solidified composite is 5 ×
It is preferably 10 ⁹ Ωcm or more. Further, in order to minimize the voltage drop due to leakage current or the like, the specific resistance is more preferably 10 ¹⁰ Ωcm or more, and in this case, it is not necessary to give a large storage capacitance to each pixel electrode.

FIG. 1 is a schematic view showing the basic structure of the projection type liquid crystal optical device of the present invention. In FIG. 1, the lamp 1
The light emitted from the lens is condensed by the lens 2 etc., passes through the lens 3 that makes the light parallel rays, enters the reflective liquid crystal optical element 4, and is reflected by the reflective function layer provided on the back electrode substrate side. The light is then emitted to the incident side, passes through the lens 3 again, is condensed, passes through the diaphragm 5 which is a device for reducing diffused light, and is projected onto a screen (not shown) by the lens 6 of the projection optical system.

Although the light source of the present invention is simply shown in FIG. 1, a combination of a lamp with an ellipsoidal mirror, a parabolic mirror, a spherical mirror, a lens and the like can be used as a light source optical system. .. Examples of the lamp include a halogen lamp, a metal halide lamp, a xenon lamp and the like. further,
A cooling system may be added to this light source, or an infrared cut filter or an ultraviolet cut filter may be combined. Further, the laser light may be expanded and collimated by a beam expander and used as incident light.

When color lights are divided and made incident on a plurality of liquid crystal optical elements, light sources of three colors may be prepared from the beginning, or light may be split by a dichroic mirror, a dichroic prism or the like. If it is specifically applied to the apparatus of FIG. 1, a dichroic prism may be arranged between the lens 3 and the reflective liquid crystal optical element 4. In that case, three reflective liquid crystal optical elements are arranged on the three exit surfaces of the dichroic prism.

As the projection optical system, a conventional projection optical system including a lens or the like is used, but a device for reducing diffused light is combined with the projection optical system. The device that reduces this diffused light is the light that travels straight and is reflected with respect to the incident light among the light that has passed through the liquid crystal optical element (the pixel part is transmitted through the transmissive part and is reflected by the reflective film on the back side). It is sufficient to reduce the light (light coming in) that has been extracted and reflected without going straight (light that is scattered in the scattering state of the liquid crystal solidified composite). In particular, it is preferable to reduce the diffused light, which is the light reflected without going straight, without reducing the light that goes straight and is reflected.

The device for reducing the diffused light may be arranged in front of or behind the lens of the projection optical system or between the lenses in combination with the projection optical system as shown in FIG. The device for reducing the diffused light is not limited to the aperture or the spot which is the diaphragm as described above, but may be, for example, a small-area mirror arranged on the optical path. Further, the focal length and aperture of the projection lens may be selected so as to remove diffused light without using a special aperture or the like.

In order to shorten the optical path length, it is effective to incorporate a device for reducing diffused light in the projection optical system. In this case, the optical system becomes simpler and the size can be kept smaller than the case where the projection optical system and the device for reducing the diffused light are installed independently.

When a plurality of reflective liquid crystal optical elements are used in the projection optical system, the emitted light may be projected separately, or they may be combined into one and then projected. Good. However, it is preferable to combine and project them into one because the number of optical axes becomes one, and the degree of freedom in use increases. In particular, as described above, in the case of splitting with a dichroic prism for incidence, in the case of a reflection type liquid crystal optical element, the same dichroic prism can be used for synthesizing emitted light, and it is possible to use few expensive parts. It has great advantages. It also leads to downsizing of the projection type liquid crystal optical device.

FIG. 2 is a sectional view of a reflective liquid crystal optical element used in the projection type liquid crystal optical device of the present invention. In FIG. 2, 11 is a front electrode substrate, 12 is a transparent electrode formed on its inner surface, 13 is an antireflection film formed on its outer surface, 14 is a liquid crystal solidified composite, 15 is a back electrode substrate, and 16 is a back electrode substrate. Reference numeral 17 denotes an electrode, a reflective film formed of a dielectric multilayer film formed on the upper surface of the back electrode.

The front electrode substrate of the reflective liquid crystal optical element of the present invention is a transparent substrate such as glass or plastic, and a transparent electrode such as In ₂ O ₃ --SnO ₂ (ITO) or SnO ₂ is formed on its inner surface. And is usually a solid electrode. An antireflection film is provided on at least the surface (the surface on the side on which light is incident) of this front electrode substrate. Preferably, antireflection films are provided on both surfaces.

This antireflection film is made of SiO ₂ , TiO ₂ , ZrO ₂ , MgF whose refractive index is adjusted with that of the substrate or electrode.
_{It is} a single-layer or multi-layer interference film of an inorganic substance such as ₂ , Al ₂ O ₃ , CeF ₃ or an organic substance such as polyimide. In addition, in FIG.
Although the antireflection film is provided between the transparent electrode 12 and the liquid crystal solidified composite 14 on the inner surface side, the antireflection film may be provided between the substrate itself of the front electrode substrate and the transparent electrode 12. Further, in the multilayer antireflection film, the refractive index and the film thickness of the transparent electrode may be adjusted and used as constituent elements. Further, it may be a film having fine irregularities on the inner surface side, which prevents regular reflection due to scattering.

When the front electrode substrate 11 is bonded to a material having a refractive index similar to that of the front electrode substrate material such as a dichroic prism for color separation / synthesis described later with an optical adhesive or coupling oil, Since the interface reflection does not occur, the antireflection film 13 is unnecessary.

Since the back electrode substrate has an electrode and has a reflecting function by a reflecting film, it is made of glass, plastic,
Any of metal, ceramic, semiconductor, etc. may be used. The back electrode may be a transparent electrode such as ITO or SnO ₂ or an opaque electrode such as aluminum or chromium when a reflective film is provided on the back electrode as in the example of FIG. 2. As will be described later, the back electrode may have to be a transparent electrode depending on the positional relationship between the back electrode and the reflective film.

Since this back electrode is patterned and used as a pixel electrode, an active element such as a TFT (thin film transistor), thin film diode, or MIM is provided and connected as necessary. In order to reduce undesired reflection, it is preferable that such an active element is provided on the back electrode substrate and at least the surface of the front electrode substrate is made as flat as possible to reduce reflection.

The reflective film 17 formed of a dielectric multilayer film includes a translucent dielectric thin film having a relatively high refractive index formed on the inner surface of the back electrode substrate 15 and a translucent dielectric thin film having a relatively low refractive index. And are laminated. The multilayer film is made of SiO ₂ , MgF ₂ , Na ₃
Low refractive index transparent dielectric thin film such as AlF ₆ and TiO ₂ , Z
rO ₂ , Ta ₂ O ₅ , ZnS, ZnSe, ZnTe, S
i, Ge, Y ₂ O ₃ , Al ₂ O _{3 and} other high refractive index translucent dielectric thin films are alternately laminated, and have a structure in which a reflection wavelength band, a transmission wavelength band, and a reflectance are required. ,material·
The film thickness and number of layers are different, and the degree of freedom in design is wider than that of metal films.

There are two types of positional relationship between the back electrode 16 on the back electrode substrate 15 and the reflective film 17 made of a dielectric multilayer film. That is, one is a case where the reflective film 17 made of a dielectric multilayer film is formed on the back electrode substrate 15 on which the back electrode 16 is formed as shown in FIG. The other is a case where the back electrode 16 is formed on the back electrode substrate 15 on which the reflective film 18 made of a dielectric multilayer film is formed as shown in FIG.

The former can be applied to all back electrode substrates and back electrodes, but the latter is not applicable to the case where Si is used for the back substrate and active elements are formed for each pixel in the substrate. However, since the TFT is usually formed on the glass substrate, there is no problem in forming the TFT on the dielectric multilayer film formed on the glass substrate. Also in the latter case,
The back electrode is a transparent electrode.

The back electrode is preferably formed on the reflective film of the dielectric multi-layer film in that the applied voltage directly acts on the liquid crystal solidified composite. Therefore, the configuration of FIG. 3 is preferable in terms of low voltage driving. In this case, when an active element is formed on each of the back electrodes, it is preferable that the uppermost layer of the reflective film formed of the dielectric multilayer film which is in contact with the active element is made of a material that does not react at the interface. For this reason, specifically, SiO ₂ , TiO ₂ , ZrO ₂ , Ta
It is preferably an oxide dielectric such as ₂ O ₅ or Al ₂ O ₃ .

On the other hand, when a reflective film of the dielectric multilayer film is formed on the back electrode substrate on which the back electrode and the active element are formed as shown in FIG. 2, one voltage applied to the reflective film of the dielectric multilayer film is used. Parts are consumed. As a result, the effective driving voltage rises, but the dielectric multilayer film has an advantage of acting as a protective film for the electrodes and active elements.

When an active element is formed on each of the back electrodes, it also functions as a light-shielding film so that the light incident on the reflective liquid crystal optical element does not reach the active element directly. As a result, even when an active element such as amorphous silicon having a large photoconductive effect is used, it is possible to reduce the generation of photoinduced current without separately providing a light shielding layer.

In order to further increase the degree of light shielding, a light shielding film may be formed on the dielectric multilayer film at each active element position on the back electrode substrate side. In this case, since the dielectric multilayer film serves as a protective film for the active element, the reliability of the active element is high even when a light-shielding film of a photosensitive polymer is used and even when an alkaline developer is used for patterning by photoetching.

The reflection film formed of the dielectric multilayer film may be formed on the entire surface of the back electrode substrate with the same spectral characteristics as shown in FIGS. 2 and 3, or different back electrodes may have different spectral characteristics. You may form what has a characteristic. A concrete example of this is shown in FIG.
4 and FIG. 5 as an example corresponding to FIG.

In FIG. 4, the electrodes corresponding to RGB of the back electrode are denoted by 16R, 16G, and 16B, and the reflective film formed on the electrode is a dielectric multilayer film having a selective reflection property of RGB corresponding to the back electrode. Are represented by 17R, 17G, and 17B. Further, in FIG. 5, the electrodes corresponding to RGB of the back electrode are represented by 16R, 16G, and 16B, and are formed on the interface with the back electrode substrate, and the dielectric multilayer film having the selective reflection property of RGB corresponding to the back electrode. The reflective film by 18R, 18G,
Expressed as 18B.

By adopting such a structure, full color display can be performed by one liquid crystal optical element. Of course, when multi-color display may be performed instead of full color, a dielectric multilayer film having two types of wavelength selective reflection may be used.

When full color display is performed by using three reflective liquid crystal optical elements, the reflective film formed of the dielectric multilayer film of each liquid crystal optical element may be the same reflective film having no wavelength selective reflection property. This is because the light from the light source optical system is split into three colors by the color separation means such as a dichroic mirror and a dichroic prism and supplied to the liquid crystal optical element. The light separated by such color separation means does not include light other than the respective color components.

Even in such a case, it is preferable that the reflective film formed of the dielectric multilayer film of each liquid crystal optical element is a reflective film having different wavelength selective reflectivity. this is,
This is because the color purity may be insufficient only by color separation using a dichroic mirror or a dichroic prism. A polarizing plate is not used in the transmission / scattering liquid crystal optical element. For this reason, the wavelength range of passage (reflection) of the dichroic mirror or dichroic prism is P polarized light and S polarized light.
Since it differs depending on the polarized light, color separation tends to be insufficient.

Further, in the case of a transmissive liquid crystal optical element, since the dichroic mirrors or dichroic prisms for color separation and color synthesis are different, a combination having different spectral characteristics is adopted to improve the color purity of RGB colors. Can be improved. However, in the case of the reflective liquid crystal optical element, due to the restriction of the optical path, the same dichroic mirror or dichroic prism for color separation and color synthesis is used. Therefore, as compared with the case of a transmissive liquid crystal optical element, R
The degree of freedom in adjusting the color purity of GB color is low, and it is difficult to improve the color purity.

In particular, when a light source having a good color rendering property such as a halogen lamp, a metal halide lamp, a xenon lamp is used, light in the wavelength range of 570 to 590 nm is mixed in G or R, and the color purity is deteriorated as compared with CRT. , Tend to be a problem in full color display.

In the present invention, color purity can be greatly improved by forming a reflective film of a dielectric multilayer film having wavelength selective reflectivity that does not reflect in the wavelength region of this boundary region. Specifically, when the colors are separated into RGB colors, the light in the boundary region of RG enters both the R and G liquid crystal optical elements. Similarly, the light in the boundary area of GB is G and B.
Incident on both liquid crystal optical elements.

In this case, at least one of the R and G liquid crystal optical elements does not reflect the light in the boundary region of RG, and at least one of the G and B liquid crystal optical elements has the G color.
The light in the border area of B is not reflected. As a result, the colors emitted from the liquid crystal optical elements do not overlap, and the color purity is improved. More specific combinations are shown in Table 1 and Table 2.
Shown in. In Tables 1 and 2, "light" represents the amount of light and "color" represents the color purity. Good things A to C, respectively
(A is the best), and bad is represented by x. ○ is
It means that each liquid crystal optical element transmits and reflects the corresponding light component.

[0051]

[Table 1]

[0052]

[Table 2]

In Example 1, since both the boundary regions of RG and GB are included in both liquid crystal optical elements, if the wavelength range of these boundary regions is wide, the color purity is lowered. In particular, when a white lamp having a high color rendering property is used, a decrease in color purity of G or R becomes a problem. Example 2 is an example in which wavelength selective reflectivity is imparted only to the reflective film of the G liquid crystal optical element. Since both boundary regions of RG and GB are included only in R or B, respectively, the color purity does not decrease. In particular, even when a white lamp having a high color rendering property is used, if the light in the wavelength range of 570 to 590 nm is cut by the G selective reflection film, the G color purity is improved.

Example 3 is an example in which wavelength selective reflectivity is given only to the reflective films of the G and B liquid crystal optical elements, and RG and GB are used.
Since both boundary regions are included only in R or G, the color purity does not decrease. Example 4 is an example in which the reflective films of all the liquid crystal optical elements are provided with wavelength selective reflectivity, and since both boundary regions of RG and GB are not included in both, color purity does not decrease.

Example 5 is better than Example 1 but inferior in color purity to Examples 2 to 4. This is an example in which only the reflective film of the G liquid crystal optical element is provided with wavelength selective reflectivity so that light having a wavelength close to R is transmitted, and the boundary region of RG is R
Included only in the liquid crystal optical element of. In this case, the GB boundary region is included in both G and B, but the apparent color purity is less deteriorated than the mixture of red and green colors.

Example 6 is an example in which wavelength selective reflectivity is given only to the reflective film of the R liquid crystal optical element, and the boundary region of RG is G
Included only in the liquid crystal optical element of. In this case, the color purity of G is inferior to that of Example 5, but the color purity of R is improved. Example 7
This is an example in which wavelength selective reflectivity is given only to the reflective films of the R and G liquid crystal optical elements, and the boundary region of RG is not included in the R and G liquid crystal optical elements. In this case, the color purity of R is improved as compared with Example 5.

Combinations other than the above are conceivable, but when a white lamp with high color rendering is used,
570 to 590 which causes deterioration of R or G color purity
The use of the wavelength selective reflection film of the reflection film of the liquid crystal optical elements of Examples 2 to 7 described above is particularly useful for removing light in the nm wavelength region.

The reflective film of the dielectric multi-layered film can obtain various spectral characteristics by changing the structure of the multi-layered film and has a high degree of design freedom. Therefore, the color purity is not sufficient only with the dichroic mirror or the dichroic prism. Even in such a case, there is an advantage that the effect of the filter for correcting the color purity as described above is exhibited.

The emitted lights may be combined by the same or another color combining means such as a dichroic mirror or a dichroic prism, and may be incident on the projection optical system and projected on the screen. Alternatively, the images may be separately made incident on the projection optical system and projected to synthesize the images on the screen.

In the present invention, in particular, the dichroic mirror or the dichroic prism is used to separate the light from the white projection light source system into the three colors of RGB and to combine the respective color lights that have respectively passed through the three reflective liquid crystal optical elements. It is preferable that the reflective film of the dielectric multilayer film of each reflective liquid crystal optical element has a spectral reflection characteristic corresponding to each color. This enables full-color display with high color purity. Further, since the same dichroic mirror or dichroic prism can be used for the color separation / combination system as compared with the case of using the transmission type liquid crystal optical element, the projection type liquid crystal optical device can be downsized.

On the other hand, when a reflective film of a dielectric multilayer film having different spectral characteristics is formed for each back electrode of the back electrode substrate, a different color display is provided for each electrode. In particular, as in the case of the direct-view type color liquid crystal optical element in which the color filter is formed on the front electrode substrate, the spectral reflectance of the reflective film formed by the dielectric multilayer film is set to 1 unit of three RGB colors in the adjacent pixels. Color projection display is possible with a single reflective liquid crystal optical element.

Also in this case, desired spectral characteristics and high reflectance can be obtained by changing the material and the number of layers of the dielectric multilayer film. Therefore, compared with the light absorption type color filter,
It is possible to display with high color purity and high light utilization efficiency.

The reflective film of the dielectric multilayer film of the present invention may be formed on the entire surface of the display portion of the back electrode substrate as shown in FIGS. 2 to 5, or may be formed only on the back electrode portion. Good. When it is not necessary to change the wavelength-selective reflectivity for each part as shown in FIGS. 2 and 3, it is preferable to form a solid surface because it is easier to manufacture. In addition, when there are irregularities due to electrodes, active elements, etc. as shown in FIG. 2, it is possible to fill the concave portions with a transparent material and flatten the surface before forming the reflective film of the dielectric multilayer film.

Further, when a liquid crystal optical element which is in a liquid crystal solidified substance complex and is in a scattered state in a state where no voltage is applied, scattered light is not projected by a device for reducing diffused light, resulting in a dark display. Therefore, it is not necessary to form a light shielding film between the electrodes of each pixel. For this reason, when finely processing a reflective film formed of a dielectric multi-layered film having spectral reflectance characteristics of RGB, the dimensional accuracy thereof is less severe than that of the conventional TN liquid crystal that requires the formation of a light shielding film. ..

When the reflective film formed of the dielectric multilayer film has wavelength selective reflectivity, light may escape to the back side. In this case, when the back electrode substrate is not opaque, it is preferable that the air side interface of the back electrode substrate is such that the light transmitted through the reflective film of the dielectric multilayer film is regularly reflected at this interface and does not overlap with the projected light. Specifically, a black light absorption layer may be formed, or a frost shape with fine irregularities may be formed, or an antireflection film may be formed. Thereby, the regular reflection light can be reduced and a high extinction ratio can be obtained.

Further, when an active element is provided for each pixel, particularly, in the case of an active element such as amorphous silicon having a large photoconductive effect, a light-shielding film used in a normal transmission type is used as a front electrode substrate or a back electrode. If the substrate is formed at a position corresponding to each active element, the photoconductive effect due to the incident light of the active element does not occur.

The operation of the projection type liquid crystal optical device of the present invention will be described using a liquid crystal optical element sandwiching a liquid crystal solidified composite in a scattering state in the absence of applied voltage.

In the pixel portion in the transmissive state of the reflective liquid crystal optical element, light is transmitted, reflected by the reflective film (regular reflection), and emitted. This straight light is a light that passes through a device that reduces diffused light, so that it is displayed brightly on the projection screen. On the other hand, light is scattered at the pixel portion in the scattered state and is emitted as diffused light. Most of this light will not be able to pass through the device that attenuates the diffuse light, so it will appear dark on the projection screen.

In the present invention, since the liquid crystal optical element of the reflection type is used, in the pixel portion in the scattering state, the light that reaches the back side without being scattered is reflected and passes through the scattering portion again, so that it is further scattered. As a result, a high scattering rate is obtained in the thin liquid crystal solidified composite layer. Further, when the transmission type liquid crystal optical element has the same scattering ability, the liquid crystal solidified substance composite layer can be made thin, so that the driving voltage can be reduced.

In the present invention, a liquid crystal solidified substance composite is composed of a solidified substance matrix having a large number of fine pores formed therein and a liquid crystal filled in the pores thereof, and either when a voltage is applied or when no voltage is applied. In the state, the refractive index of the solidified matrix is made to substantially match the refractive index of the liquid crystal used. In this case, it is preferable to use a liquid crystal solidified substance composite in which the refractive index anisotropy Δn of the liquid crystal used is 0.18 or more. In particular, it is preferable to use a nematic liquid crystal having a positive dielectric anisotropy so that the refractive index of the solidified matrix thereof substantially matches the ordinary refractive index (n _o ) of the liquid crystal used.

This liquid crystal solidified composite is sandwiched between a front electrode substrate and a back electrode substrate having a reflective film of a dielectric multilayer film to form a reflective liquid crystal optical element. The refractive index of the liquid crystal changes depending on the applied state of the voltage between the electrodes of this reflection-type liquid crystal optical element, and the relationship between the refractive index of the solidified matrix and the refractive index of the liquid crystal changes. When they match, they are in a transmissive state (normally reflected and light is emitted), and when they have different refractive indices, they are in a scattered state (diffused light is emitted).

A liquid crystal solidified substance composite composed of a solidified substance matrix having a large number of fine pores formed therein and a liquid crystal filled in the pores is such that the liquid crystal is contained in liquid bubbles such as microcapsules. Although it has a structure, individual microcapsules do not have to be completely independent, and liquid bubbles of individual liquid crystals may communicate with each other through a slit like a porous body.

The liquid crystal solidified substance composite used in the reflection type liquid crystal optical element of the present invention is prepared by mixing the liquid crystal and the curable compound constituting the solidified substance matrix to form a solution or latex. The solidified substance matrix may be separated by performing photo-curing, heat-curing, curing by removing a solvent, reaction curing or the like so that the liquid crystal is dispersed in the solidified substance matrix.

This curable compound is preferably a photocurable or thermosetting type because it can be cured in a closed system. In particular, the use of a photocurable curable compound is preferable because it can be cured in a short time without being affected by heat.

As a concrete manufacturing method, a conventional ordinary TN is used.
A cell is formed using a sealing material as in the case of the liquid crystal optical element, and an uncured mixture of liquid crystal and a curable compound is injected from the injection port, and the injection port is sealed and then irradiated with light or heated. It can also be cured.

In addition, in the case of the reflective liquid crystal optical element of the present invention, for example, a liquid crystal and a curable compound are provided on one of the front electrode substrate and the back electrode substrate without using a sealing material. It is also possible to supply an uncured mixture, and then stack the other electrode substrate and cure it by light irradiation or the like.

Of course, thereafter, a sealing material may be applied to the periphery to seal the periphery. According to this manufacturing method, the uncured mixture of the liquid crystal and the curable compound may simply be supplied by roll coating, spin coating, printing, coating with a dispenser, etc., so that the injection step is simple and the productivity is extremely high. Good.

The uncured mixture of these liquid crystals and the curable compound contains ceramic particles for controlling the substrate gap, plastic particles, spacers such as glass fibers, pigments, dyes,
Viscosity modifiers and other additives that do not adversely affect the performance of the present invention may be added.

By curing an element that is in a scattering state when no voltage is applied in such a state that a sufficiently high voltage is applied only to a specific portion during this curing step, that portion can be kept in a light transmitting state at all times. Therefore, when there is something that is desired to be fixedly displayed, such a normal transmission portion may be formed. Conversely, in the case of an element that is in a transmissive state when no voltage is applied, the ordinary scattering portion can be similarly formed.

The higher the transmittance in the transmissive state of the reflective liquid crystal display element using this liquid crystal solidified composite, the better, and the haze value in the scattered state is preferably 80% or more.

In the present invention, the refractive index of the solidified matrix (after curing) is the same as the refractive index of the liquid crystal used in either the voltage applied state or the non-voltage applied state, and in the opposite state, The index of refraction is not matched to that of the liquid crystal used. As a result, the light is transmitted when the refractive index of the solidified material matrix and the refractive index of the liquid crystal match, and the light is scattered (white turbid) when they do not match. The scattering property of this element is higher than that of a conventional DS mode reflective liquid crystal display element, and a display with a high contrast ratio can be obtained.

[0082] In the present invention, particularly, in a voltage applied state, the refractive index of the solidified matrix (after curing) is preferably made to coincide with the liquid crystal n _o used. As a result, since a transmissive state is achieved when a voltage is applied, the transmissivity during light transmission is high and the light is evenly transmitted, so that the display contrast ratio is improved.

The liquid crystal dispersed and held in the solidified matrix is preferably independent particles or particles in which some of them are connected. This is effective in achieving both high scattering power and high transparency when driven at a low voltage. Scattering is caused by the presence of an interface between the liquid crystal and the solidified matrix. Therefore, the larger the area of this interface, the higher the scattering property. In order to increase the area of this interface with a certain optimum liquid crystal particle diameter, it is important to increase the amount of liquid crystals independently separated from the resin, that is, increase the liquid crystal particle density.

However, as the amount of the liquid crystal separated from the solidified matrix is increased, the respective liquid crystal particles come into communication with each other, and further, the liquid crystal comes to have a structure in which all the liquid crystal communicates with each other. The loss of the liquid crystal interface separated from the matrix leads to a decrease in the scattering ability.

Refractive index anisotropy Δn (= n _{e of} the liquid crystal used)
-N _o) is the contribution to scattering, obtain a high scattering property,
It is preferable that it is larger than a certain level, specifically, Δn>
0.18 is preferable, and Δn> 0.22 is particularly preferable.
Further, n _o of the liquid crystal used is preferably set to substantially match the refractive index of the solidified matrix (n _p), high transparency when an electric field is applied to obtain the time. More specifically, n _o -0.
03 <it is preferable to satisfy the relationship of n _p <n _o +0.05.

Further, in order to improve the scattering property, it is effective to increase the volume fraction Φ of the operable liquid crystal of the liquid crystal solidified composite, and Φ> 20% is preferable, and the higher scattering property is obtained. Φ> 35% is preferred, and Φ> 4
5% is preferable. On the other hand, if Φ is too large, the structural stability of the liquid crystal solidified composite is deteriorated, so Φ <70% is preferable.

In the liquid crystal solidified substance composite of the reflection type liquid crystal optical element of the present invention, since the liquid crystal molecules are arranged under the influence of the solidified substance matrix wall surface when no voltage is applied, they are not arranged in a fixed direction. .. Therefore, when the refractive indexes of the two are different in this state, a scattering state (that is, a cloudy state) is shown.

When such a reflection type liquid crystal optical element which shows a scattering state when no voltage is applied is used as a projection type optical device, light is scattered in a portion having no electrode, and the portion other than the pixel portion of the back electrode is scattered. Even if the light shielding film is not provided, the light does not reach the projection screen and thus appears black. As a result, in order to prevent leakage of light from parts other than the pixels,
Since it is not necessary to shield the portion other than the pixels with a light shielding film or the like, there is also an advantage that the step of forming the light shielding film is unnecessary.

When the wiring electrode of the pixel is formed, a weak electric field is generated in the liquid crystal solidified composite layer between itself and the counter electrode, and incident light passes through the liquid crystal solidified composite layer,
There may be a case where black display is not performed due to reflection by the wiring electrode. As a countermeasure, a light absorption layer is formed on the wiring electrode,
Alternatively, a light shielding film may be formed at a corresponding position on the front electrode substrate.

A voltage is applied between the electrodes of a desired pixel. In the pixel portion to which this voltage is applied, the liquid crystal is arranged in parallel with the electric field direction, and n _{o of} the liquid crystal and n of the solidified matrix are arranged.
_{When p} coincides with _p, it indicates a transmissive state, and light is transmitted through the desired pixel, resulting in a bright display on the projection screen.

By curing such an element in such a state that a sufficiently high voltage is applied only to a specific portion during this curing step, that portion can be kept in a light transmitting state at all. If desired, such a normally permeable portion may be formed.

When a TFT is used as an active element in the present invention, silicon may be suitable as a semiconductor material. In particular, since polycrystalline silicon has low photosensitivity like amorphous silicon, malfunction does not occur even if the light from the light source is not blocked by the light blocking film, which is preferable. When this polycrystalline silicon is used as a projection type liquid crystal optical device as in the present invention, a strong projection light source can be used and a bright display can be obtained.

Further, in the case of the conventional TN type liquid crystal optical element, a light-shielding film is often formed between the pixels in order to suppress light leakage from the pixels. At the same time, the light-shielding film can be simultaneously formed on the active element portion, and the formation of the light-shielding film on the active element portion does not significantly affect the whole process. That is, even if polycrystalline silicon is used as the active element and the light shielding film is not formed in the active element portion, the number of steps cannot be reduced if the light shielding film needs to be formed between the pixels.

On the other hand, in the present invention, as described above,
The use of by liquid crystal and solidified matrix composite such that substantially coincides with the liquid crystal n _o the refractive index of the resin matrix used, black in the projection screen in a portion where no voltage is applied is projected light is scattered Therefore, it is not necessary to form a light shielding film between pixels.

The optical performance of the dielectric multilayer film is determined by the material used and the number of layers. However, if the thickness becomes thicker, the voltage drop there becomes larger and the driving efficiency of the liquid crystal deteriorates. For example, the thickness of the SiO ₂ film and the TiO ₂ film is 1.
The reflectance of the 5 μm multilayer film is about 99%, and the remaining 1% is leaked light. At this time, the voltage drop is about 0.5 to 0.6 V although there are other factors. By using other materials (SiO ₂ film and Si film) or increasing the number of layers, the reflectance is 99.9.
It can be 9%.

The reflectance is not uniquely determined, but
When used as a projection type liquid crystal optical device, the desired screen light amount and the light intensity of the light source to be used are related, and therefore the combination may be an optimum combination.

When polycrystalline silicon is used as the active element, polycrystalline silicon has a relatively low photosensitivity, so that malfunction due to light is unlikely to occur. For this reason, the strictness of the light-shielding property is not required even if the light-shielding film is not formed in the active element portion, so that the step of forming the light-shielding film can be eliminated or simplified, and the productivity is improved.

Even when amorphous silicon, which has a higher photosensitivity than polycrystalline silicon, is used, a light-shielding film is formed on the semiconductor portion of the amorphous silicon to allow a slight leakage of light (for example, a reflectance of 99 to 99. 95% of the time)
Can be used.

Whether polycrystalline silicon or amorphous silicon is used as the active element, by forming a dielectric multilayer film on the back electrode substrate surface on which the pixel electrode and the active element are formed as shown in FIG. It can be said that most of the incident light is reflected by the multilayer film and the amount of light incident on the active element becomes small, and the dielectric multilayer film itself functions as a light shielding film and has a light shielding effect.

In the liquid crystal optical element and the liquid crystal optical device of the present invention, an infrared cut filter, an ultraviolet cut filter or the like may be laminated, characters or figures may be printed, or a plurality of liquid crystal optical elements may be provided. May be used.

Further, in the present invention, a protective plate such as a glass plate or a plastic plate may be laminated on the outside of the liquid crystal optical element. As a result, even if the surface is pressed, the risk of damage is reduced, and safety is improved.

In the present invention, it is preferable to use a photocurable compound as the uncured curable compound which constitutes the above-mentioned liquid crystal solidified composite, and it is particularly preferable to use a photocurable vinyl compound. Specifically, a photocurable acrylic compound is exemplified. Particularly, those containing an acrylic oligomer which is polymerized and cured by light irradiation are preferable.

[0103] The liquid crystal used in the present invention may be a nematic liquid crystal, the liquid crystal such as refractive index of the solidified matrix agrees with the liquid crystal n _o is preferred. This liquid crystal
The composition may be used alone or, but it can be said that it is advantageous to use the composition in order to satisfy various performance requirements such as operating temperature range and operating voltage.

When a photocurable compound is used as the liquid crystal used in the liquid crystal solidified composite, it is preferable that the photocurable compound is uniformly dissolved, and the cured product after photoexposure is not dissolved. Alternatively, it is preferably made difficult to dissolve. Further, when the composition is used, it is preferable that the solubility of each liquid crystal is as close as possible.

In the case of producing a liquid crystal solidified composite, the substrate and the counter electrode substrate are arranged so that their electrode surfaces face each other like a conventional ordinary liquid crystal optical element, and the periphery is sealed with a sealing material, The uncured liquid mixture for the solidified liquid crystal complex may be injected from the inlet to seal the inlet, or the uncured mixture of the curable compound and the liquid crystal may be supplied on one of the electrode substrates. Alternatively, the other electrode substrate may be laminated to manufacture.

In the liquid crystal optical element of the present invention, a dichroic dye, a simple dye or a pigment may be added to the liquid crystal, or a curable compound colored may be used.

In the present invention, liquid crystal is used as a solvent in the liquid crystal solidified substance complex, and the photocurable compound is cured by photoexposure, so that it is not necessary to evaporate a simple solvent or water which is unnecessary at the time of curing. Therefore, since it can be cured in a closed system, the conventional manufacturing method of injecting into a cell can be adopted as it is, and it has high reliability and also has the effect of adhering two substrates with a photocurable compound, which is more reliable. Will be more likely.

By thus forming the liquid crystal solidified composite, the risk of short circuit between the upper and lower transparent electrodes is low, and
Unlike a normal TN type liquid crystal optical element, it is not necessary to strictly control the orientation and the substrate gap, and a liquid crystal optical element capable of controlling the transmission state and the scattering state can be manufactured with extremely high productivity.

The ratio of the straight-ahead component and the scattered component reaching the projection screen can be controlled by the diameter of a spot, a mirror or the like, which is a device for reducing diffused light, and the focal length of a lens, to obtain a desired display contrast and display. It may be set so that brightness can be obtained.

When a device for reducing diffused light such as an aperture is used, it is preferable that the light incident on the liquid crystal optical element from the light source for projection is more parallel in order to increase the brightness of the display. It is preferable to configure a light source optical system by combining a light source having a brightness and as close as possible to a point light source, a concave mirror, a condenser lens, and the like. For this purpose, by using a light source having a high directivity such as a laser beam, it is possible to obtain light that is closer to parallel and to obtain a high contrast ratio.

Further, in the above description, the device for reducing the diffused light was mainly explained by the aperture and the spot, but a small mirror may be arranged instead of the spot so that only the necessary light can be taken out.

Further, in the case of the reflective type as compared with the transmissive type, the back electrode substrate does not need to be a translucent material such as glass and the degree of freedom in material selection is high. Further, a heat sink, a temperature controller such as a heater or a Peltier element may be installed on the surface of the back electrode substrate together with a thermometer to control the temperature of the liquid crystal solidified substance composite in the optimum operating temperature range.

The projection type liquid crystal optical device of the present invention may be any one as long as the light from the light source for projection is incident on the reflection type liquid crystal optical element and the reflected and emitted light is used. Therefore, it includes not only a display device that projects an image on a large-sized projection screen but also a reflection-type light modulator.

[0114]

In the present invention, since a liquid crystal solidified substance composite is used as a reflection type liquid crystal optical element, high scattering characteristics can be obtained even with a thin liquid crystal solidified substance composite, and as a characteristic of the element itself, a high contrast ratio is obtained. Is obtained.

Further, since the reflecting film made of the dielectric multilayer film is used, an optical reflecting surface having a better flatness can be obtained and the reflectance is higher than that of the reflecting film made of the metal film. As a result, the high contrast ratio can be improved. can get.

Furthermore, since the spectral reflectance can be arbitrarily adjusted according to the structure of the reflective film formed of the dielectric multilayer film, the same effect as that of the light absorption type color filter can be obtained. Since the dielectric multilayer film color filter is superior to the light absorption type color filter in the steepness of the light separation wavelength and the extinction ratio, a color optical element having high color purity and light utilization rate can be obtained.

[0117]

【Example】

(Example 1) Glass substrate (Corning "705
9 "), one surface was frosted so that the transmitted light was not specularly reflected. An ITO transparent electrode was provided on the surface of the substrate where the surface was not roughened, and three back electrode substrates were prepared in which a polycrystalline silicon TFT was arranged as a back electrode for each pixel. As shown in FIG. 2, SiO ₂ having a refractive index of 1.45 and TiO ₂ having a refractive index of 2.35 are alternately formed on each of the back electrode substrates so that each optical film thickness nd = λ / 4 (λ: in each RGB. 20 layers are laminated, and the reflectance is 99 in each of the RGB wavelength bands.
%, A reflective film of a dielectric multi-layer film was formed on the entire surface of the substrate by a vacuum deposition method to prepare a back electrode substrate.

On the other hand, one surface of the same glass substrate was formed with fine irregularities to the extent that regular reflected light was reduced and transmitted light was not extremely reduced, and an ITO transparent electrode was further formed thereon. On the opposite surface, Al ₂ O ₃ , ZrO ₂ , MgF
_An antireflection film consisting of the three-layer film of ₂ was formed to prepare a front electrode substrate in which the reflectance in the visible region was suppressed to 0.2% or less. Peripheral portions of the back electrode substrate and the front electrode substrate were sealed with a sealing material to form three cells of RGB.

The cell shape is a diagonal of 4.4 inches, the number of pixels is 480 vertical × 640 horizontal, and each pixel size is 140 μm × 1.
It was 40 μm. Further, in this transmission / scattering type liquid crystal optical element, it is not necessary to form the light-shielding film on the front electrode substrate, which is required in the conventional TN type liquid crystal optical element. In the state of the liquid crystal optical element, the aperture ratio of the pixel is as high as 58%.

Further, by forming a reflection film of a dielectric multilayer film to form a reflection type liquid crystal optical element, the additional capacitance portion can also be used as an opening, so that the aperture ratio is 6
A large value of 7% was obtained. When a conventional transmissive TN type liquid crystal optical element having the same TFT configuration is used, the aperture ratio remains as low as 40% due to the formation of the light shielding film.

A nematic liquid crystal having Δn of about 0.24 and Δε of about 16 was uniformly dissolved in an acrylate monomer, a bifunctional urethane acrylate oligomer, and a photo-curing initiator, and the solution was injected into the cell. The object composite was cured to prepare three reflective liquid crystal optical elements having a liquid crystal content of 68 wt%.

As shown in FIG. 6, these three reflection type liquid crystal optical elements 21R, 21G and 21B for RGB are used to convert the light from the light source optical system 22 into a parallel light by a condenser lens 24 through a reflecting mirror 23. After that, it was placed immediately after color separation into RGB three colors by the cross type dichroic mirror 25. Each liquid crystal optical element 21R, 21G,
The incident light to 21B is obliquely incident within an incident angle of 10 °,
The RGB color lights that are normally reflected on the reflecting surface of the dielectric multilayer film enter the cross dichroic mirror 25 again, and the three RGB colors are color-synthesized, and the condensing lens 24 and the reflecting mirror 26.
After that, the light is focused on the diaphragm 27 which is a device for reducing diffused light.
Then, the projection optical system 28 including the diaphragm 27 as a component projects the image on a projection screen (not shown).

At this time, a diaphragm which is a device for reducing diffused light
The converging angle δ (= 2 tan ⁻¹ (φ / 2f)) determined by the diameter φ of 27 and the focal length f of the condensing lens 24 was set to 8 °. A metal halide lamp having a light source of 250 W and an arc length of 5 mm was used as a light source, and the light was collected by an elliptical mirror with a cold mirror. As a result, the contrast ratio on the projection screen was 120 and the luminous flux was 800 lumen.

Further, the light (wavelength 500 to 590 nm) other than the light having a wavelength of 495 nm or less and 595 nm or more, which is reflected by the crossed dichroic mirror and is incident on the reflective liquid crystal optical element for RG, has a wavelength of 500 to 590 nm. Incident on. For this reason, when the reflective films of the three RGB cells are not provided with selective reflectivity, the color purity of the projected image is CR.
It was slightly lower than T. Therefore, as the reflective film of the liquid crystal optical element for G, a reflective film having a selective reflectivity that reflects light having a wavelength of 560 nm or less and transmits light having a wavelength of 570 nm or more is used. As a result, the reflective film also functions as a dichroic filter, and a color purity of CRT or higher was achieved.

In this embodiment, the cross-type dichroic mirror is used in the color separation / synthesis system. However, although the cost is high, the angle adjustment is not necessary and the reflection type liquid crystal optical element is directly bonded to the antireflection film. It is also possible to use a dichroic prism in which the interface reflection disappears without forming the.
Although the volume increases, a normal non-intersecting dichroic mirror may be used.

(Comparative Example 1) When an aluminum film was used as a back electrode and a reflective film instead of the back electrode and the reflective film of Example 1, the contrast ratio was 90 and the luminous flux was 600 lumens. Further, in the case of a transmissive liquid crystal optical element in which a reflective film is not provided on the back electrode substrate (other configurations are the same), the light collection angle δ
= 5 °, the contrast ratio was 120 and the luminous flux was 450 lumens. Further, in all cases, the color purity of the above-mentioned green was poor, and the color became yellowish green.

(Embodiment 2) The same substrate as in Embodiment 1 is used, an ITO transparent electrode is provided on the surface of the substrate on which the surface is not roughened, and an amorphous silicon TFT is used as a back electrode for each pixel. A back electrode substrate on which was arranged was produced. Each adjacent pixel on the back electrode substrate, that is, the pixel electrode -T
On the FT-electrode wiring, as shown in FIG.
SiO ₂ and TiO ₂ having a refractive index of 2.35 are alternately laminated in an appropriate film thickness of 20 to 30 layers, each having a reflectance of 98% or more in the RGB wavelength band and a reflectance of 5% or less in other wavelength bands. A reflective film (RGB filter) having wavelength selective reflectivity as shown below was formed by a high frequency magnetron sputtering method.

In this case, unlike the first embodiment, the structure of the multilayer film is designed so that the reflectance is reduced at wavelengths other than the RGB reflection wavelength bands. The patterning of the reflective film for each pixel was performed by ordinary photolithography. The front electrode substrate was prepared in the same manner as in Example 1. However, TF
As a light-shielding film for T, an antireflection film was formed between the glass substrate and a Cr film, which was then patterned and ITO was formed on the entire surface. The periphery of the back electrode substrate and the front electrode substrate was sealed with a sealing material to form one cell, and the same liquid crystal and resin raw material as in Example 1 were injected and cured.

The cell shape is diagonal 10.4 inches, the number of pixels is 480 vertical × 640 horizontal (× 3: RGB), each pixel size is 330 μm × 110 μm, and 11 adjacent in the horizontal direction.
A reflection type dielectric multilayer filter corresponding to RGB is formed in a mosaic pattern in a pixel of 0 μm. Further, in this transmission / scattering type liquid crystal optical element, the aperture ratio of the pixel is 55% in the state of the transmission type liquid crystal optical element before forming the reflection film.
And shows a high value. Furthermore, by forming a reflective film of a dielectric multilayer film to form a reflective liquid crystal optical element,
Since the additional capacitance part can also be used as an opening,
A large aperture ratio of 63% was obtained.

This reflection type liquid crystal optical element 31 is arranged immediately after the light from the light source optical system 32 is collimated by the condenser lens 34 through the reflecting mirror 33, as shown in FIG. Liquid crystal optical element
Incident light to 31 is obliquely incident within an incident angle of 10 °, is regularly reflected on the reflection film surface of the dielectric multilayer film, and is incident to the condenser lens 34 again to the diaphragm 37 which is a device for reducing diffused light. Collected. Then, the projection optical system 38 including the diaphragm 37 as a constituent element projects the light onto a projection screen (not shown).

At this time, a diaphragm which is a device for reducing diffused light
The converging angle δ determined by the diameter φ of 36 and the focal length f of the lens is 8 ° as in the first embodiment, and the light source optical system is 40
Using a metal halide lamp with 0 W and an arc length of 5 mm,
The light was collected by an elliptical mirror with a cold mirror. As a result, a contrast ratio of 120 on the projection screen and a luminous flux of 2500
I got a lumen.

(Comparative Example 2) As the back electrode substrate of Example 2, an aluminum film was used as the back electrode and the reflection film instead of the back electrode and the reflection film, and a light absorbing type R was used as the front electrode substrate.
A liquid crystal optical element was prepared using a GB mosaic color filter formed between a transparent electrode and a substrate. The device had a contrast ratio of 30 and a luminous flux of 1000 lumens.

Further, in the case of a transmissive liquid crystal optical element in which a reflective film is not provided on the back electrode substrate (other configurations are the same), the converging angle δ = 5 °, the contrast ratio was 120, and the luminous flux was 800 lumen. .. Then, in all of the cases using the light absorption type RGB mosaic color filter, the RGB color purity was inferior to that in the case of using the liquid crystal optical element of the present example.

Example 3 As the front electrode substrate and the back electrode substrate, transparent electrodes of ITO were provided in segments on a glass substrate, and 1/3 duty multiplex driving electrodes were patterned. As shown in FIG. 2, SiO ₂ having a refractive index of 1.45 and T having a refractive index of 2.35 are formed on the back electrode substrate on which the segment electrodes are formed.
Alternating io ₂ optical film thickness (refractive index x film thickness) 266 nm
Then, 30 layers were laminated so that the reflection mirror had a reflectance of 99.9% or more at the oscillation wavelength of 1064 nm of the Nd: YAG laser, and was formed by the vacuum deposition method.

In order to prevent the transmitted light from being regularly reflected on the outer surface of the back electrode substrate on which the segment electrodes are not formed,
A frosted surface was used. In addition, at the interface between the glass substrate of the front electrode substrate and the liquid crystal solidified composite,
By forming a dielectric multilayer antireflection film having an ITO transparent electrode film as a constituent element, the interfacial reflected light is reduced to 0.2% or less, and the outer surface is a V-type reflection consisting of a two-layer film of ZrO ₂ and SiO _2. An anti-reflection film is formed to reduce the reflectance at a wavelength of 1064 nm to 0.
What was suppressed to 2% or less was used.

A nematic liquid crystal having Δn of about 0.27 and Δε of about 16 was uniformly dissolved in an acrylate monomer, a bifunctional urethane acrylate oligomer and a photo-curing initiator, and the solution was injected into the cell. The object composite was cured to prepare one reflective liquid crystal optical element having a liquid crystal content of 68 wt%.

The cell shape is 230 mm × 150 mm, and an operation area of 192 mm × 96 mm exists in this central portion. In the operation area, 1.9 mm square segments were arranged at a pitch of 2 mm, 96 segments in the horizontal direction and 48 segments in the vertical direction, and the aperture ratio of the pixel was about 90%.

The driving was performed with 1/3 duty and 1/3 bias. Off voltage is an effective value of 4V as driving voltage
Driven to be _rms . The reflectance at a wavelength of 1064 nm when no voltage is applied is about 1%, and the reflectance when a voltage is applied is about 5%.
A high energy utilization factor and a high contrast ratio of about 55 were achieved.

As shown in FIG. 8, this reflection type liquid crystal optical element 41 uses an Nd: YAG laser as a projection light source system 42,
The emitted light was irradiated onto the liquid crystal optical element 41 by expanding the collimated light irradiation diameter to the effective surface of the liquid crystal optical element by a Kepler-type afocal optical system using two condenser lenses 44A and 44B and a reflecting mirror 43. The liquid crystal optical element 41 was arranged immediately after the light from the light source optical system 42 was collimated by the condenser lens 44B.

Light incident on the liquid crystal optical element 41 has an incident angle of 10
The light enters obliquely within an angle, is regularly reflected by the surface of the reflective film formed of the dielectric multilayer film, enters the condenser lens 44B again, and is condensed on the diaphragm 47 which is a device for reducing diffused light in the figure. And
A projection optical system 48 installed behind the diaphragm 47 reduces and projects the laser irradiation target 49.

At this time, since the laser beam has high directivity,
Since the light is condensed into a small spot at the position of the diaphragm 47 which is a device for reducing the diffused light, the converging angle δ is set to 1 ° or less. The reduction image magnification of the liquid crystal optical element formed at the position of the irradiation object 49 can be arbitrarily changed by the combination of the condenser lens and the projection optical system. Further, when the liquid crystal optical element has a rectangular shape, it is preferable to use a cylindrical lens in the lens system before entering the liquid crystal optical element so that the laser beam can be effectively used. Further, a scanning optical element such as a polygon mirror may be provided between the laser and the liquid crystal optical element in order to scan the reduced projection image on the irradiation target position and perform multi-pattern irradiation.

Therefore, by using such an optical system and placing an absorber of 1064 nm light at the position of the laser irradiation object, the display pattern of the liquid crystal optical element is printed or processed, and the laser marker, laser processing machine, laser solder, A laser welder etc. was obtained.

Example 4 The liquid crystal optical element of Example 1 has a structure as shown in FIG. As a result, the opening was smaller and the brightness was slightly lower than in Example 1, but the voltage required for driving could be slightly lower. There was almost no difference in the contrast ratio.

(Embodiment 5) In the liquid crystal optical element of Embodiment 1, leak light of incident light that passes through the dielectric multilayer film and is incident on the TFT is completely blocked, and deterioration of image quality due to photosensitivity of the TFT is prevented. In order to suppress it, as shown in FIG. 9, a light shielding film was formed on the dielectric multilayer film at a position corresponding to the TFT of each pixel on the back electrode substrate. The other configurations were the same as those in Example 1.

The light-shielding film used here is not a Cr metal film which is usually used by forming a film on a front electrode substrate in a transmissive active matrix liquid crystal display element, but a black color in which fine carbon particles are dispersed in a photosensitive polymer. In addition, a photosensitive polymer (CK-2000, Fuji Hunt Electronics Technology Co., Ltd.) having a high electric insulation property was used. In this case, when the metal film is used as the light-shielding film, the dielectric multilayer film mirror interposed between the TFT and the metal film acts as a capacitor, and thus the TFT
Deteriorate the characteristics of. Further, in the case of the reflection type, the incident light is reflected by the reflection on the metal surface, so that the TFT portion is not shielded from light corresponding to black.

By using the black photosensitive polymer as in the embodiment, no additional capacitance is generated, and even when the reflective type of the present invention is used, the TFT portion is always displayed in black and the contrast ratio of the projected image is deteriorated. It is not the cause.

The black photosensitive polymer used in this example can be finely patterned by exposure to ultraviolet light as in the case of a negative photoresist, and the portion exposed to ultraviolet light is cured by an alkali developing solution. To remain. Usually TF
T has a problem of chemical resistance against an alkaline solvent, but in the manufacturing process of the reflection type liquid crystal optical element of the present invention, the alkali developing solution does not come into direct contact with the TFT,
Since the dielectric multilayer film acts as a protective film, the TFT is not adversely affected. Actually, a black photosensitive polymer having a film thickness of 1 to 2 μm was formed by patterning on the dielectric multilayer film at the TFT position of each pixel.

When an alignment film is required at the interface with the liquid crystal, such as a TN type liquid crystal optical element, etc.
If the m projections are present on the substrate, it becomes difficult to form a uniform alignment film, and thus it becomes necessary to form a flattening film thereon. However, since the liquid crystal solidified composite does not require an alignment film, there is no problem even if protrusions of about 1 to 2 μm are present on the substrate due to the element structure.

A similar black photosensitive polymer may be pattern-formed on aluminum, which is the electrode wiring, in order to reduce reflection on the metal surface. in this case,
Unlike the light blocking of the TFT, the light blocking degree acts on the reciprocal movement of light, so that the film thickness may be half that of the TFT light blocking film. Alternatively, since the voltage is not always applied between the electrode wiring and the counter electrode and the liquid crystal cured material composite layer is not in a transparent state, the contrast ratio of the projected image is slightly deteriorated, but the light shielding for the electrode wiring is not performed. The membrane may be omitted. Further, in order to reduce aluminum metal reflection, a black metal oxide such as Cr ₂ O ₃ may be used in addition to the black photosensitive polymer.

With such a structure, the TF
Since the light leaked to T was further reduced, even when light with high illuminance of 1 million lux or more was incident on the display element of this example,
The photo-induced leak current of the TFT was completely eliminated, and the background light in the black display was also reduced. As a result, the contrast ratio of the projected image and the image quality were improved as compared with Example 1. In addition, the reduction of the pixel aperture ratio due to the formation of the light shielding film is 2
It was about%.

This liquid crystal optical element was actually used in the same light source system and projection optical system as in Example 1 to evaluate the projected image. However, in order to further brighten the projected image, the light source was changed to a metal halide lamp of 250W to 400W. As a result, the contrast ratio on the projection screen was 140 and the luminous flux was 1300 lumen, although the illuminance of light incident on the liquid crystal display element was increased 1.6 times.

In this embodiment, as shown in FIG. 9 or 11, the light shielding film in the case where the dielectric multilayer film is formed on the back electrode substrate on which the pixel electrode and the active element are formed has been described. However, similarly to the back electrode substrate in which the pixel electrode and the active element are formed on the substrate on which the dielectric multilayer film is formed, the above-mentioned photosensitive polymer is also provided at the active element position as shown in FIG. 10 or 12. The light-shielding film may be patterned by using-. In this case, since the dielectric multilayer film does not act as a protective film for the active element, it is necessary to pay attention to the development conditions so as not to deteriorate the active element in the development using the alkaline solution.

Further, although the case where the light shielding film is formed on the TFT substrate side is described in this embodiment, a black matrix may be formed on the TFT or the wiring portion on the counter substrate side as in the conventional case. In this case, if a metal film such as a Cr film is directly formed on a flat glass surface, regular reflection is increased, which causes a deterioration in the contrast ratio of the projected image. Therefore, an antireflection film of Cr such as Cr ₂ O ₃ is formed between the glass or the glass with ITO and the Cr film. Alternatively, it is preferable to reduce the regular reflection by forming a Cr film on the frosted glass surface as described above.

Example 6 The same reflection type TFT as in Example 1
In order to improve the effective aperture ratio of the TFT by using the substrate,
A microlens array was mounted on the front electrode substrate on the light incident side of the liquid crystal display element of the present invention. The sectional view is shown in FIG. When the reflective liquid crystal display element of the present invention is combined with a microlens array to improve the aperture ratio of a TFT, it differs from the conventional transmissive or reflective liquid crystal display in the following two points.

First, when a microlens array is combined with a transmissive liquid crystal display element, the microlens array is brought into close contact with the liquid crystal display element on the light incident side, and the microlens array is not normally used on the light emitting side. As a result, even if the light incident on the display element has a uniform directivity, the directivity of the light emitted from the display element is disturbed after being condensed on the TFT opening by the microlens array.

Therefore, in order to project the light having the disordered directivity without loss, it was necessary to use a projection lens having a small F number, that is, a large aperture. This has made it difficult to use a high-resolution, high-magnification, compact projection lens.

Further, in the case of the transmission / scattering type display, if the directivity of the light of the transparent pixel is disturbed by the microlens, the scattered light and the non-scattered light cannot be distinguished, and the function of the scattered light removing system is reduced. As a result, there arises a problem that the contrast ratio of the projected image is deteriorated. Such problems are solved by mounting microlens arrays on the light incident side and the light emitting side of the transmissive liquid crystal display element,
Since the number of parts is increased and the time and effort for alignment are increased, the cost becomes high.

In the case of the structure of this embodiment, since it is used as a reflection type, one microlens array allows light to pass twice on the light incident side and the light emitting side. Therefore, if parallel light with uniform directivity is used as the incident light and the reflection surface of the liquid crystal display element is located at the focal position of the microlens, the reflected light of the straight traveling light (non-scattered light) is obtained as shown in FIG. By passing through the microlens array again, parallel light with uniform directivity is obtained.

Therefore, as in the case of the conventional transmission type, the directivity of the incident light and the emitted light of the transparent pixel does not change even if one microlens array is used, and as a result, the specifications of the projection lens depend on the presence or absence of the microlens. No need to change. That is, the projection lens can be used with its performance maintained, and the function of the scattered light removing system does not deteriorate.

Secondly, as a reflection type liquid crystal display element using a conventional TN type liquid crystal, an optical system in which a prism type polarization element is arranged on the light incident side of the liquid crystal display element is known. In this case, in order to obtain the optimum optical characteristics of the prism type polarizing element, the incident light is made to enter the reflective surface of the liquid crystal display element vertically.

At this time, it is only necessary that the incident light of the same pixel of the microlens array provided on the light incident side is reflected and the emitted light emitted therefrom is transmitted through the same microlens. In this case, similarly to the transmissive type, it suffices to dispose the centers of the individual microlenses so as to coincide with the centers of the openings of the pixels.

However, in the case of the reflection type liquid crystal display element of the present invention, the combination with the conventional prism type polarization element is not suitable because it sacrifices the brightness. As shown in FIG. It is preferable that light is incident on the surface at an angle. In that case, it is impossible to condense incident light on a specific pixel by the same microlens and parallelize reflected light on the dielectric multilayer film surface of the pixel electrode again without sacrificing light utilization efficiency.

Therefore, as shown in FIG. 13, two adjacent microlenses are used in the plane including the optical axis, and the center of the display electrode of the pixel is located at the center between the centers of the microlenses. The arrangement and installation of the microlens array is determined, and the light incident on one of the microlenses at an angle to the reflection surface of the liquid crystal display element is condensed at the center of the pixel display electrode, and the reflected light is reflected by the other microlens. It is preferable to determine the focal length and light incident angle of the microlens so that the light is emitted to the lens.

Specifically, the relationship as shown in FIG. 13 is satisfied, and the pixel length of the liquid crystal display element (= side length corresponding to the pixel length of the microlens) is a, and the focal length of the microlens is Where f is the distance from the principal point of the microlens to the reflecting surface, the incident angle of the incident light with respect to the reflecting surface of the liquid crystal display element is θ, and the refractive index of the front electrode substrate glass is n, d = n × f = It is preferable that the structure satisfies the relationship of 0.5 × a / tan θ (1). However, the focal length f of the microlens is a value when both sides are air, and it is approximated that the microlens array and the front electrode substrate (made of glass) have the same refractive index.

The liquid crystal display element of this embodiment has a pixel size of 14
Since a TFT in which square pixels of 0 μm × 140 μm are arranged in a lattice is used, a = 140 μm, and the incident angle θ of the incident light with respect to the reflection surface of the liquid crystal display element is 5 °.
When the refractive index n of the surface electrode substrate glass is 1.5, the focal length f of the microlens is set to about 0.53 mm from the relationship of the formula (1).

The thickness of the front electrode substrate glass and the microlens array was determined so that the distance d from the principal point of the microlens to the reflecting surface was 0.8 mm. As the microlens array, one directly formed on the front electrode substrate glass may be used, or the flat surface of the separately prepared microlens array may be adhered to the front electrode substrate (made of glass). In this case, it is not necessary to form an antireflection film on the surface of the front electrode substrate, but it is preferable to form an antireflection film on the air interface with the microlens array. The microlens array may be regular plano-convex homogenized glass,
It may be a gradient index flat plate microlens array by ion diffusion.

Using the thus prepared liquid crystal display device with a microlens array, the projection image was evaluated by the same optical system as in Example 1, and as a result, a TFT having an aperture ratio of 67% was obtained.
However, the same light utilization efficiency as that of the TFT having an aperture ratio of 85% was effectively obtained.

Even when a TFT having an aperture ratio of 40% and a low aperture ratio is used, a TF having an aperture ratio of 85% can be effectively formed by using the liquid crystal display element structure with the microlens array.
The same light utilization efficiency as T was obtained. Since an elliptic mirror is used as a condenser mirror as the light source system of the present embodiment and a diaphragm is arranged at the second focal position, incident light to the reflection type liquid crystal display element depends on the aperture diameter and the focal length of the condenser lens. The directivity can be adjusted, and in the present embodiment, the range of the directivity is set to 8 °, which is the same as the converging angle of the scattered light removing system.

As a result, the incident light is condensed into a circle having a diameter of about 90 μm on the surface of the pixel electrode, and if the TFT has an aperture ratio of 40% or more, all of them are about 85% corresponding to the effective aperture ratio of the microlens array. This is because the incident light can be used without light loss. Further, by using the incident light and the microlens array having such directivity, the incident light is condensed only on the pixel electrode portion, and T
Since light does not reach the FT and the wiring portion position, it is not necessary to form a light shielding film.

Actually, using this liquid crystal optical element with a microlens array, the projection image was evaluated with the same optical system configuration as in Example 1. As a result, a contrast ratio of 140 on the projection screen and a luminous flux of 1000 lumens were obtained.

The microlens array of this embodiment is effective for a transmission-scattering and reflection-type liquid crystal optical element, and not only when the reflection function is a dielectric multilayer film, but also when a general metal film is used. It is also applicable when used.

[0172]

In the projection type liquid crystal optical device of the present invention, the liquid crystal material sandwiched between the front electrode substrate and the back electrode substrate is a liquid crystal solidified substance capable of electrically controlling the scattering state and the transmitting state. Since a reflective liquid crystal optical element sandwiching the composite is used, no polarizing plate is required, and the transmittance of light at the time of transmission can be greatly improved compared to the conventional TN type liquid crystal optical element, which is bright. A projected image is obtained.

The reflective liquid crystal optical element used in the present invention is capable of controlling high scattering property and high transmissivity by changing the applied state of voltage, and it has a substrate gap larger than that of the transmissive type. Can be driven at a low voltage because
Even in the case of driving using a driving IC for a conventional TN type liquid crystal optical element, a display having a high contrast ratio and high brightness can be realized.

In particular, in the present invention, since the reflection film of the dielectric multilayer film is used as the reflection film of the back electrode substrate, the problem such as the deterioration of the optical mirror surface due to the reaction with the substrate interface material hardly occurs and the reflectance is high. It is easy to obtain a flat mirror surface that does not absorb light. Further, since it has no conductivity, there is no problem of short circuit with the wiring electrode.

Furthermore, selective reflectivity can be imparted by the structure of the multilayer film. Therefore, it can function as a reflection-type color filter that does not absorb light. As a result, it is possible to obtain a bright projection display with a good contrast ratio while taking advantage of the fact that a thin substrate space can be provided, which makes it possible to drive at a low voltage.

Further, since the reflective liquid crystal optical element used in the present invention does not need to use a polarizing plate, its optical characteristics have little wavelength dependence, and color correction of the light source is almost unnecessary. I also have. In addition, since problems such as rubbing or other alignment treatment essential to the TN type liquid crystal optical element and destruction of the active element due to static electricity accompanying it can be avoided, the manufacturing yield of the liquid crystal optical element can be greatly improved.

Furthermore, since this liquid crystal solidified composite is in the form of a film after curing, problems such as short circuit between substrates due to pressure of the substrates and breakage of active elements due to movement of spacers are unlikely to occur.

Further, this liquid crystal solidified composite has a specific resistance equivalent to that of the conventional TN mode, and it is not necessary to provide a large storage capacitance for each pixel electrode as in the conventional DS mode. Is easy to design, the ratio of the effective pixel electrode area can be easily increased, and the power consumption of the liquid crystal optical element can be kept low.

Further, since the manufacturing process of the conventional liquid crystal optical element of the TN mode can be carried out only by removing the alignment film forming process, the production is easy.

Further, the liquid crystal optical element using this liquid crystal solidified composite has a feature that the response time is short,
It is easy to display moving images. Further, since the electro-optical characteristic (voltage-transmittance) of this liquid crystal optical element is a comparatively gentle characteristic as compared with the liquid crystal optical element of the TN mode, it can be easily applied to gradation display.

[0181] Further, the liquid crystal optical element of the present invention is that so as to substantially coincide with the liquid crystal n _o of using the refractive index of the solidified matrix, the light is scattered at the portion where no voltage is applied, pixel Even if the other portions are not shielded by the light shielding film, light does not leak at the time of projection and it is not necessary to shield the gap between adjacent pixels.

Therefore, in particular, by using an active element made of polycrystalline silicon as the active element, it is possible to use a high-luminance projection light source only by providing no light-shielding film or a simple light-shielding film in the active element portion. Thus, it is possible to easily obtain a high-luminance projection type liquid crystal optical device. Further, in this case, the light-shielding film may not be provided at all, or only a simple light-shielding film may be required, and the production process can be further simplified.

Further, as compared with the transmissive liquid crystal optical element, the threshold value in the applied voltage-transmittance characteristic becomes clear, so that high duty ratio multiplex driving becomes possible, leading to higher aperture ratio and higher definition.

Further, since the reflection film of the dielectric multilayer film has almost no light absorption and is excellent in light resistance as used as a mirror for a resonator of a laser, it has high durability against high power laser light, It is possible to reduce the irradiation area of the reflection type liquid crystal optical element, increase the laser power density, and reduce the size.

Further, as shown in another embodiment of the liquid crystal optical element of the present invention, if a light shielding film is provided on the back electrode substrate side, the optical characteristics can be further improved.

Further, by disposing the microlens array on the front electrode substrate side as shown in another embodiment, the optical path of the light reaching the back electrode substrate can be controlled, and malfunction of the active element can be reduced. And the efficiency of light can be improved. Further, the optical characteristics can be further improved by using the reflective functional layer formed of the above-mentioned dielectric pair multilayer film and the light shielding film together.

In addition to the above, the present invention can be applied in various ways within a range that does not impair the effects of the present invention.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a basic configuration of a projection type liquid crystal optical device of the present invention.

FIG. 2 is a cross-sectional view showing the basic structure of a reflective liquid crystal optical element of the present invention.

FIG. 3 is a cross-sectional view showing a liquid crystal optical element of the present invention in which a back electrode on the back electrode substrate side has a reflective film as a base.

FIG. 4 is a sectional view showing a liquid crystal optical element of the present invention in which a reflective film is provided on the upper surface of a full-colored back electrode.

FIG. 5 is a sectional view showing a liquid crystal optical element of the present invention in which a base of a full-colored back electrode is a reflective film.

FIG. 6 is a schematic view showing another example of the projection type liquid crystal optical device of the present invention.

FIG. 7 is a schematic view showing another example of the projection type liquid crystal optical device of the present invention.

FIG. 8 is a schematic view showing another example of the projection type liquid crystal optical device of the present invention.

FIG. 9 is a cross-sectional view showing an example of a liquid crystal optical element of the present invention in which a reflective film is provided between an active element and a light shielding film.

FIG. 10 shows a back electrode on the back electrode side, which is a reflection film,
Sectional drawing which shows the example of the liquid crystal optical element of this invention which provided the active element and the light shielding film on it.

FIG. 11 is a cross-sectional view showing an example of a liquid crystal optical element of the present invention, which is full-colored and in which a reflective film is provided between a back electrode and an active element provided side by side, and a light shielding film.

FIG. 12 is a cross-sectional view showing another example of the liquid crystal optical element of the present invention, which is full-colored and provided with a back electrode, a light-shielding film, a reflective film (base surface), and an active element.

FIG. 13 is a sectional view showing an example of a liquid crystal optical element with a microlens of the present invention.

[Explanation of symbols]

 1: Lamps 2, 3, 6: Lens 4: Liquid crystal display element 5: Aperture 7: Microlens array 8: Adhesive material 11: Front electrode substrate 12: Transparent electrode 13: Antireflection film 14: Liquid crystal solidified composite 15: Back electrode substrate 16: Back electrodes 17, 18: Reflective film 19: Active element 20: Light-shielding film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsuneo Wakabayashi 1160 Matsubara, Hazawa-machi, Kanagawa-ku, Yokohama, Kanagawa Prefecture AZ Technology Co., Ltd.

Claims (10)

[Claims] 1. A nematic liquid crystal is dispersed and held in a solidified matrix between a front electrode substrate having a transparent electrode and a back electrode substrate, and the solidified substance is formed when a voltage is applied or not applied. Between the back electrode substrate and the solidified matrix, there is a transmission-scattering type operation mode in which a liquid crystal solidified composite is sandwiched so that the refractive index of the matrix substantially matches the refractive index of the liquid crystal used. A liquid crystal optical element in which a reflective function layer is provided on the reflective function layer, the transmissive dielectric thin film having a relatively high refractive index and the transparent dielectric thin film having a relatively low refractive index are laminated. A liquid crystal optical element having a reflecting film formed of a dielectric multilayer film as described above. 2. The liquid crystal optical element according to claim 1, wherein the reflective functional layer has wavelength selective reflectivity. 3. The liquid crystal optical element according to claim 1, wherein the electrode of the back electrode substrate is composed of divided pixel electrodes,
Each pixel electrode is driven by an active element provided for each pixel, and a light-shielding film is patterned and formed on the electrode surface side of the back electrode substrate or the electrode surface side of the front electrode substrate corresponding to the position of the active element. Liquid crystal optical element to do. 4. The liquid crystal optical element according to claim 3, wherein a reflective function layer is formed on the pixel electrode and the active element,
Further, the liquid crystal optical element is characterized in that a light shielding film is formed by patterning at a position corresponding to the active element on the reflection function layer. 5. A nematic liquid crystal is dispersed and held in a solidified matrix between a front electrode substrate having a transparent electrode and a back electrode substrate, and the solidified substance is formed when a voltage is applied or not applied. Between the back electrode substrate and the solidified matrix, there is a transmission-scattering type operation mode in which a liquid crystal solidified composite is sandwiched so that the refractive index of the matrix substantially matches the refractive index of the liquid crystal used. A liquid crystal optical element in which a reflective function layer is provided on the back electrode substrate, which is composed of divided pixel electrodes,
Each pixel electrode is driven by an active element provided for each pixel, a microlens array is arranged on the light incident side of the front electrode substrate, and the optical axis of the light incident on the back electrode surface is the vertical axis of the substrate surface. The light incident on one microlens of the adjacent microlenses of the microlens array is converged at the surface position of the pixel electrode and further reflected by the reflection function layer, and the other microlens is inclined by the angle θ from The liquid crystal is characterized in that the pixel size, the angle θ, the arrangement of the pixel electrode and the microlens, the focal length of the microlens, the thickness of the front electrode substrate and the refractive index of the front electrode substrate are selected so as to be emitted to Optical element. 6. The liquid crystal optical element according to claim 5, wherein the pixel size and the size of each microlens are substantially the same, the pixel size is a, the focal length of the microlens is f, and the principal point of the microlens is the reflection film surface. And d is the distance to the front electrode substrate and n is the refractive index of the front electrode substrate, the liquid crystal optical element is characterized by the following relationship: d = n × f = 0.5 × a / tan θ. 7. The liquid crystal optical element according to claim 5 or 6, wherein the reflective function layer comprises a translucent dielectric thin film having a relatively high refractive index and a translucent dielectric thin film having a relatively low refractive index. A liquid crystal optical element having a reflection film formed of the dielectric multilayer film as described above. 8. A projection type liquid crystal optical device provided with a light source optical system, a liquid crystal optical element and a projection optical system, wherein the liquid crystal optical element according to any one of claims 1 to 7 is used. A projection type liquid crystal optical device characterized in that light enters the liquid crystal optical element from the front electrode substrate side, is reflected by the reflective functional layer, is emitted from the front electrode substrate side, and is further projected by a projection optical system. 9. The projection type liquid crystal optical device according to claim 8, wherein a color separation optical system is provided between the light source optical system and the liquid crystal optical element, and the color separation light is incident on different liquid crystal optical elements, and a plurality of them are provided. 2. A projection type liquid crystal optical device, wherein at least one of the reflective function layers of the liquid crystal optical element has wavelength selective reflectivity so as to compensate for the decrease in color purity due to the color separation optical system. 10. The projection type liquid crystal optical device according to claim 8 or 9, wherein the reflective function layer of the liquid crystal optical element is formed by being divided into a plurality of portions having different wavelength selective reflection properties. Type liquid crystal optical device.