JPH06301051A - Spatial optical modulation element - Google Patents

Abstract

PURPOSE:To provide a space optical modulating element capable of decreasing the variations in contrast by improving the contras in the pixel display part of a photoconductive later which is a light receiving later and uniformalizing the layer thickness of a liquid crystal layer which is an optical modulating layer. CONSTITUTION:The film thickness of the photoconductive layer 5 in peripheral parts 7 of display pixels is set at the same thickness as the film thickness of the photoconductive layer 5 in a pixel display part 6. Metallic reflection films 8 having a laminated structure of chromium and aluminum are formed on the photoconductive layer 5 in the pixel display part 6 and metallic peripheral light shielding films 11 likewise having the laminated structure of the chromium and aluminum are formed on the photoconductive layer 5 in the peripheral parts 7 of the display pixels.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a projection display,
The present invention relates to a spatial light modulator used in a holographic television or an optical arithmetic device.

[0002]

2. Description of the Related Art High-definition televisions having large screens and high-density pixels have been developed and put into practical use in various systems. Above all, the development of a projection display using liquid crystal technology in place of the conventional cathode ray tube (CRT) system has been actively pursued. With the cathode ray tube method, the brightness of the screen is reduced and the screen becomes dark for high density pixels. Further, it is difficult to increase the size of the cathode ray tube itself. On the other hand, although a projection display apparatus using a liquid crystal element of a transistor drive system is a promising method, it has problems that the aperture ratio does not increase and the element is expensive. Further, a liquid crystal light valve using a CRT as an optical input means has been attracting attention as a device having a simple element shape and combining the advantages of a CRT and a liquid crystal element (Japanese Patent Laid-Open No. 63-109422).

In recent years, it has become possible to display a moving image on a large screen of 100 inches or more by combining a highly sensitive amorphous silicon light receiving layer and a liquid crystal. Further, by using a ferroelectric liquid crystal capable of high-speed response as a liquid crystal material, it has become possible to realize a liquid crystal light valve with higher speed and higher resolution. This liquid crystal light valve is also expected to be the core of next-generation parallel computing devices and optical computing devices that utilize the memory properties and binary characteristics of ferroelectric liquid crystals.

By the way, in a spatial light modulator or a liquid crystal light valve composed of a liquid crystal layer and a photoconductive layer, when read light irradiating a minute metal reflection film corresponding to each pixel reaches the photoconductive layer, the contrast is increased. Cause to decrease. Therefore, in a spatial light modulator or a liquid crystal light valve that is composed of a liquid crystal layer and a photoconductive layer,
It is important to provide a light shielding film.

Japanese Patent Laid-Open No. 62-40430 discloses a conventional example in which a microelectrode and a light-shielding film are provided in a spatial light modulator or a liquid crystal light valve comprising a liquid crystal layer and a photoconductive layer.
There are respective publications of JP-A-62-169120. In these elements, as a light shielding film, an input light shielding film for preventing the incident light to be modulated from being superimposed on the output light,
Two types are required: an output light-shielding film for preventing reading light from leaking into the photoconductive layer and lowering the contrast of the display. When these light shielding films are provided between the photoconductive layer and the microelectrodes corresponding to the reflective layer, an electrically insulating film is used. However, when it is provided directly on the transparent conductive electrode, it need not be an electrical insulator.

On the other hand, the present inventors have proposed the following method of forming a light-shielding film (Japanese Patent Application No. 3-344521,
Japanese Patent Application No. 4-125846, Japanese Patent Application No. 4-136580
And Japanese Patent Application No. 4-136581). That is, in the spatial light modulator including the photoconductive layer, the liquid crystal layer, and the metal reflection film provided in the same plane between these layers and divided into minute shapes, the metal output light-shielding film is used. Is provided in a plane different from that of the metal reflection film having the minute shape. Further, a part of each of the separated metal reflection films and a part of the output light shielding film are brought into contact with each other through the organic polymer film.
Then, the organic polymer is made to contain carbon, an organic dye or an inorganic substance that absorbs light in a specific wavelength range.

[0007]

By the way, in the above spatial light modulator proposed by the present inventors, the following method can be adopted to form the metal reflection film and the output light-shielding film. That is, first, after forming a photoconductive layer, a metal film of chromium or the like is deposited and a resist pattern is formed by using a photolithography technique. Then, after performing wet etching, the resist is removed. Next, using the chromium pattern as an etching mask, isotropic etching is performed by a chemical dry etching method using a mixed gas of CF ₄ and oxygen to remove a part of the photoconductive layer. Then, if aluminum is vapor-deposited on the entire surface of the substrate, a metal reflection film is formed on the pixel portion,
An output light-shielding film is formed on the lower part of the depression between the pixels.

However, when such a method is adopted, as shown in FIG. 4, the photoconductive layer 41 and the liquid crystal layer 43 are adjacent to each other with the alignment film 44 in the display pixel peripheral portion 40, The reading light 45 is directly applied to the photoconductive layer 41 of the display pixel peripheral portion 40. For this reason,
Electric charges are generated in the display pixel peripheral portion 40, and the electric charges are carried to the pixel display portion 39 located at the center, and the electric potential of the pixel fluctuates irrespective of the image signal, significantly lowering the contrast of the display image. become.

The photoconductive layer 41 of the display pixel peripheral portion 40 is also used.
Since there is no etching mask pattern of chrome on the top, the peripheral photoconductive layer 41 is removed by the same depth as the photoconductive layer 41 between pixels in the process of etching the photoconductive layer 41, and the pixel display portion 39 and A step is generated between the display pixel peripheral portion 40. The layer thickness of the liquid crystal layer 43 is controlled by the size and amount of spheres (hereinafter referred to as “beads”) 46 of several μm made of glass or the like dispersed as a spacer between two substrates. 39 and display pixel peripheral part 4
The difference from 0 causes a large variation in the layer thickness of the liquid crystal layer 43, resulting in a large variation in the contrast of the displayed image.

In order to solve the above-mentioned problems of the prior art, the present invention improves the contrast of the pixel display portion of the photoconductive layer which is the light receiving layer, and uniformizes the layer thickness of the liquid crystal layer which is the light modulation layer to provide contrast. It is an object of the present invention to provide a spatial light modulator capable of reducing the variation in the above.

[0011]

In order to achieve the above object, a spatial light modulator according to the present invention comprises a photoconductive layer in a region sandwiched by two transparent insulating substrates having transparent conductive electrodes. A liquid crystal layer, and a plurality of metal reflection films provided in the same plane between these layers and divided into minute shapes,
A spatial light modulation element having at least a metal output light-shielding film positioned in a plane different from this plane, wherein the photoconductive layer is coated on a peripheral portion of a pixel display section including the plurality of metal reflection films. It is characterized in that a metal peripheral light shielding film is provided.

In the above structure, it is preferable that part of the metal peripheral light-shielding film is connected to the transparent conductive electrode below the photoconductive layer. Further, in the above structure, it is preferable that the metal reflection film and the metal peripheral light shielding film are made of two or more layers of metal. In particular, it is preferable that the bottom layer of each of the metal reflection film and the metal peripheral light-shielding film is chromium, and the top layer is aluminum, and further, the bottom layer of the metal peripheral light-shielding film has a larger area than the top layer. preferable.

[0013]

According to the structure of the present invention, since the reading light is not directly irradiated to the photoconductive layer around the pixel display portion, no charge is generated around the pixel display portion. Since the potential of the display section does not change regardless of the image signal, the contrast of the pixel display section can be improved. Further, by etching the photoconductive layer using the metal reflection film and the metal peripheral light-shielding film as an etching mask, it is possible to make the photoconductive layer in the image display section and the peripheral section have the same film thickness, so that they are on the same plane. The beads can be dispersed to uniformly control the thickness of the liquid crystal. Therefore, it is possible to reduce the variation in the contrast of the display image, and it is possible to realize a good spatial light modulator.

In the above-mentioned structure, according to a preferable structure in which a part of the metal peripheral light-shielding film is connected to the transparent conductive electrode under the photoconductive layer, even if a pulse voltage is applied between both transparent conductive electrodes, The metal peripheral light-shielding film and the transparent conductive electrode under the photoconductive layer are held at 0 potential. Therefore, even if the writing light is incident on the metal peripheral light-shielding film, the potential of this portion does not rise, so that it is possible to realize a spatial light modulator having a better contrast.

Further, in the above structure, according to a preferable structure in which the metal reflection film and the metal peripheral light-shielding film are made of two or more layers of metal, the light-shielding degree is increased, and a spatial light modulator having a better contrast is realized. be able to. Particularly, according to a preferable configuration in which the bottom layer of each of the metal reflection film and the metal peripheral light shielding film is chromium and the top layer is aluminum, the adhesion between the transparent conductive electrode and the peripheral light shielding portion of the substrate is improved. The peeling of the transparent conductive electrode can be prevented. Further, according to a preferable configuration in which the lowermost layer (chrome) of the metal peripheral light-shielding film has a larger area than the uppermost layer (aluminum), a cell reaction between the transparent conductive electrode under the photoconductive layer and aluminum does not occur. Since it is not present, the lead-out electrode portion of the transparent conductive electrode does not peel off and break.

[0016]

EXAMPLES The present invention will be described in more detail below with reference to examples. FIG. 1 is a sectional view showing an embodiment of the spatial light modulator according to the present invention.

As shown in FIG. 1, a transparent conductive electrode 4 (eg, I) is formed on a transparent insulating substrate 2 (eg, glass).
TO (indium-tin oxide), SnO _x ) and a photoconductive layer 5 having a rectifying property (for example, an amorphous silicon semiconductor having a diode structure) are sequentially laminated. Further, on the photoconductive layer 5, a separated minute metal reflection film 8 (for example, a metal thin film of aluminum, chromium, titanium, or the like) corresponding to a pixel and an alignment film 15 for aligning the liquid crystal layer 19 (for example, , A polymer thin film such as polyimide) are arranged in that order. Further, an output light-shielding film 14 (for example, a metal thin film of aluminum, chromium, titanium, etc.) for the reading light 21 is provided between the pixels.
The plane on which the output light-shielding film 14 is provided is located below the plane on which the metal reflection film 8 is provided, so that the light-shielding effect can be improved. In addition, the metal reflection film 8
And the output light shielding film 14 are electrically separated from each other, and there is no crosstalk between adjacent pixels.

The cell thickness of the liquid crystal layer 19 is controlled by the beads 18 dispersed as spacers. Particularly when a ferroelectric liquid crystal is used as the liquid crystal layer 19, it is preferable to control the cell thickness to 1 to 2 μm. Further, the alignment film 16 is uniformly formed on the transparent conductive electrode 3 on the opposite side. In FIG. 1, 1 is a transparent insulating substrate (for example, glass).

The spatial light modulator 25 is driven by applying a pulse voltage between the transparent conductive electrodes 4 and 3. Then, information is written in the photoconductive layer 5 by writing light (input light) 20 from the side of the transparent insulating substrate 2 on which the photoconductive layer 5 is formed. The electric resistance of the photoconductive layer 5 decreases in accordance with the intensity of the writing light (input light) 20, and the liquid crystal layer sandwiched between the minute metal reflection film 8 corresponding to each pixel and the opposing transparent conductive electrode 3. The voltage applied to 19 increases. Depending on the magnitude of this voltage, the liquid crystal layer 1
The orientation of 9 changes. The linearly polarized readout light 21 passing through the liquid crystal layer is reflected by the metal reflection film 8 of each pixel, passes through the liquid crystal layer 19 again, and then passes through the analyzer 24 to output light 2.
The change in light intensity is read out as 2.

In this case, it is necessary to provide a light shielding film on the photoconductive layer 5 so that the photoconductive layer 5 is not switched by the irradiation of the reading light 21, but in the pixel display portion 6, the metal reflection film 8 shields the light. Also serves as a membrane. On the other hand, in the display pixel peripheral portion 7, the metal peripheral light-shielding film 11 covers the entire surface of the photoconductive layer 5. Therefore, the read light 21 is not directly applied to the photoconductive layer 5 of the display pixel peripheral portion 7, so that no charge is generated in the display pixel peripheral portion 7, and as a result, the potential of the pixel display portion 6 is increased. Does not change regardless of the image signal, so that the contrast of the pixel display section 6 can be improved. Further, the film thickness of the photoconductive layer 5 in the display pixel peripheral portion 7 is the same as the film thickness of the photoconductive layer 5 in the pixel display portion 6, and the pixel display portion 6 and the display pixel peripheral portion 7 are on the same plane. ing. This allows
Since the layer thickness of the liquid crystal layer 19 can be made uniform, it is possible to reduce the variation in the contrast of the display image,
A good spatial light modulator can be realized.

Further, in the present spatial light modulator 25,
Since the metal peripheral light-shielding film 11 and the transparent conductive electrode 4 are connected, even if a pulse voltage is applied between the both transparent conductive electrodes 4 and 3, the metal peripheral light-shielding film 11 and the transparent conductive electrode 4 are connected to each other. Is held at 0 potential. Therefore, even if the writing light 20 is incident on the metal peripheral light-shielding film 11, the potential of this portion does not rise, and as a result, it is possible to realize a spatial light modulator having better contrast.

The material used for the photoconductive layer 5 is, for example, CdS, CdTe, CdSe, ZnS, ZnSe,
Compound semiconductors such as GaAs, GaN, GaP, GaAlAs, InP, amorphous semiconductors such as Se, SeTe, AsSe, Si, Ge, Si _1-x C _x , Si _1-x Ge _x , G
e _1-x C _x (0 <x <1) or other polycrystalline or amorphous semiconductor, and (1) phthalocyanine pigment (hereinafter abbreviated as Pc), for example, metal-free Pc, XPc (X = Cu, Ni,
Co, TiO, Mg, Si (OH) _2, etc.), AlCl
PcCl, TiOClPcCl, InClPcCl, I
nClPc, InBrPcBr, etc., (2) azo dyes such as monoazo dyes and disazo dyes, (3) penylene pigments such as penylene anhydride and penylene acid imide,
(4) indigoid dye, (5) quinacridone pigment,
(6) Polycyclic quinones such as anthraquinones and pyrenequinones, (7) cyanine dyes, (8) xanthene dyes,
There are (9) charge transfer complexes such as PVK / TNF, (10) eutectic complexes formed from pyrylium salt dye and polycarbonate resin, and (11) organic semiconductors such as azurenium salt compounds.

Amorphous Si, Ge, Si
_{1-x Cx} , Si _1-x Ge _x , Ge _1-x C _x (hereinafter a-
Si, a-Ge, a-Si _1-x C _x , a-Si _1-x Ge
_x , a-Ge _1-x C _x ) is used as the photoconductive layer 5, hydrogen or a halogen element may be included in order to reduce the dielectric constant or increase the resistivity. It may include oxygen or nitrogen. Further, in order to control the resistivity, elements such as B, Al, and Ga, which are p-type impurities,
Alternatively, an element such as P, As, or Sb which is an n-type impurity may be added. As described above, the amorphous materials to which impurities are added are stacked to form junctions of p / n type, p / i type, i / n type, p / i / n type, etc., and the photoconductive layer 5 is depleted. Layers can be formed to control dielectric constant and dark resistance or operating voltage polarity. In addition to such amorphous materials,
A heterojunction is formed by laminating two or more of the above materials,
A depletion layer may be formed in the photoconductive layer 5.

As the liquid crystal material of the liquid crystal layer 19, it is preferable to use a chiral smectic C liquid crystal which is a ferroelectric liquid crystal. Since the thickness of the liquid crystal layer 19 is in the case of the reflective spatial light modulator, it is preferable to set the thickness to about 1 μm because the contrast ratio of the output light can be increased.

Next, a method of manufacturing the spatial light modulator having the above structure will be described with reference to FIG. First, 55m
ITO (indium-tin oxide) is formed on the glass substrate 2 of m × 45 mm × 1.1 mm by a sputter deposition method in a film thickness of 0.05 to 0.5 μm and a film forming area of 55 mm × 30 mm, The transparent conductive electrode 4 was formed. Next, hydrogenated amorphous silicon having a p / i / n diode structure (hereinafter a-Si; H
(Hereinafter abbreviated as “) film was laminated with a film thickness of about 2 μm to form the photoconductive layer 5. Here, the p layer is doped with boron by 400 ppm, and the n layer is doped with phosphorus by 50 ppm. The p-layer has a thickness of 1000 Å, the i-layer has a thickness of 1.7 μm, and the n-layer has a thickness of 2000 Å. Then, a metal film of chromium or the like having a film thickness of 2000 angstrom is formed on the surface of the photoconductive layer 5 by a resistance heating vapor deposition method or the like, and by photolithography, a film of 20 μm × 20 μm, a pitch of 25 μm, and 1000 × 1000 pixels is formed. A resist pattern having a thickness of about 2 μm was formed. Then, after etching with an etchant containing perchloric acid or the like, the resist was removed with fuming nitric acid. Then, using the chromium pattern as an etching mask, isotropic etching is performed by a chemical dry etching method using a mixed gas of CF ₄ and oxygen to form a groove of 1.3 μm in the photoconductive layer (5a-Si; H film) 5. Was set up. After this, aluminum is applied again to the entire surface of the substrate.
The metal reflection film 8, the output light-shielding film 14, and the metal peripheral light-shielding film 11 were formed by vapor deposition with a film thickness of 000 angstrom.

On the other hand, on the glass substrate 1 having a size of 55 mm × 55 mm × 1.1 mm, ITO is formed into a film having a thickness of 0.05 to 0.5 μm and a film forming area of 55 × 30 mm by a sputter deposition method, and is transparent. The conductive electrode 3 was formed. Then, a polyamic acid was applied onto both substrates by spin coating and heated at a temperature of 200 ° C. for 1 hour to form a polyimide polymer film having a thickness of about 200 Å. Next, alignment treatment was performed so that the alignment of the ferroelectric liquid crystal molecules was parallel to the thickness direction of the device, and alignment films 15 and 16 were formed. Alignment treatment (rubbing treatment)
Was performed by rubbing the surface in a certain direction with a rayon resin cloth. Then, a thermosetting resin 17 in which resin beads having a diameter of 2.6 μm are mixed is provided on the glass substrate 2 on the side where the photoconductive layer 5 is laminated, except for the liquid crystal injection opening.
Was screen-printed so as to surround the whole. Then
On the other glass substrate 1, beads 18 made of resin or the like and having a diameter of 1 μm dispersed in isopropyl alcohol were sprayed and attached to the entire surface.
Then, the pair of glass substrates are stuck together, placed in a vacuum bag, evacuated and hermetically sealed, and then heated in an atmosphere of about 90 ° C. for about 30 minutes while keeping the inside in a vacuum state, and further in an atmosphere of about 150 ° C. The resin 17 was cured by heating for about 2 hours to prepare a liquid crystal panel. Then, while heating the ferroelectric liquid crystal in a vacuum state at about 80 ° C., the ferroelectric liquid crystal is uniformly injected into the liquid crystal panel by injecting it through the opening of the resin 17 by utilizing the pressure and the capillary phenomenon caused by the introduction of nitrogen gas. Filled. In order to uniformly align the ferroelectric liquid crystal molecules, this device is placed in a thermostat at a liquid crystal phase transition temperature or higher, for example, about 9
After heating to 0 ° C. and returning to room temperature at a slow cooling rate of about 0.2 ° C./min, the opening of resin 17 was sealed with resin 17. As a result, a liquid crystal layer 19 having a thickness of 1 μm was formed between both substrates.

As described above, the spatial light modulator 25 having the structure shown in FIG. 1 is obtained. If the spatial light modulator 25 is manufactured as described above, the metal reflection film 8 and the metal peripheral light-shielding film 11 can have two layers. That is, the metal reflection film 8 and the metal peripheral light-shielding film 11 are composed of lower layers 9 and 12 made of chromium and upper layers 10 and 1 made of aluminum, respectively.
3 will be formed. Then, by forming the metal reflection film 8 and the metal peripheral light-shielding film 11 in two or more layers, the light-shielding degree was increased, and as a result, a spatial light modulator having a better contrast could be realized.

In particular, as in the present embodiment, each bottom layer 9,
A good spatial light modulator was able to be obtained by using 12 for chromium and for each uppermost layer 10, 13 for aluminum. That is, the transparent conductive electrode 4 may be peeled off due to a battery reaction between the transparent conductive electrode 4 and aluminum. However, when the material of the lowermost layers 9 and 12 is chromium, the transparent conductive electrode 4 and the substrate are separated from each other. Adhesion with the peripheral light-shielding portion was improved, and peeling of the transparent conductive electrode 4 could be prevented. In addition, since chromium is a hard metal, damage due to impact during the assembly process was eliminated. Furthermore, since aluminum has a high reflectance of 100%, the degree of light shielding is increased.

Further, by setting the lowermost layers 9 and 12 (chromium) to have a film forming area larger than that of the uppermost layers 10 and 13 (aluminum), a better spatial light modulator can be obtained. That is, when the chromium film formation area of the lowermost layers 9 and 12 is made smaller than the aluminum film formation area of the uppermost layers 10 and 13, a cell reaction between the transparent conductive electrode 4 and aluminum occurs, and the transparent conductive electrode Although there is a possibility that the lead-out electrode portion of No. 4 may be peeled off and broken, the peeling is prevented by making the chromium film forming area of the lowermost layers 9 and 12 larger than the aluminum film forming area of the uppermost layers 10 and 13. We were able to. Specifically, in this embodiment, the photoconductive layer 5
Chromium film formation area 3 on (film formation area 33 x 33 mm)
Formed in 5 × 35 mm, aluminum film formation area 34 ×
It was formed with 34 mm.

The spatial light modulator 25 produced as described above was evaluated as a projection display. FIG. 2 shows a schematic view of the projection display device.

Optical writing is performed by the CRT display 26 on the spatial light modulator 25 obtained in this embodiment. The number of pixels of the element is 480 in height and 650 in width. A light source 27 (metal halide lamp) for reading is applied to the spatial light modulator 25 via a condenser lens 28 and a polarization beam splitter 29. The output image is enlarged by the lens 30 and displayed on the screen 31. When each dot on the CRT display 26 is written in the separated pixel of the spatial light modulator 25, it is converted into a quadrangle on the screen 31.

The spatial light modulator 25 has a large aperture ratio of 80% to obtain a bright image, and an image enlarged to a size of 100 inches has a light flux of 1000 lm or more on the screen 31. It was also confirmed that the contrast of the moving image on the screen 31 was 200: 1 and the resolution was 650 TV lines in the vertical direction. In addition, when a moving image was output, a clear high-luminance image was obtained with no afterimage with respect to the movement of the video rate.

Next, using the spatial light modulator 25,
When the holographic television device shown in FIG. 3 was assembled, reproduction of a stereoscopic image displayed in real time was confirmed. The He-Ne laser 32 of coherent light was used to illuminate the subject 33, and an interference fringe pattern was formed on the image pickup surface of the CCD 35 together with the reference light passing through the collimator 34. This image data was transferred to the CRT 36 and optically written in the spatial light modulator 25 to reproduce the interference fringe pattern. When a He-Ne laser 37 of coherent light was used to read in the reflection mode, a clear three-dimensional image with high contrast was observed. In FIG. 3, reference numeral 38 is a polarization beam splitter.

[0034]

As described above, according to the configuration of the present invention, the photoconductive layer in the periphery of the pixel display portion is not directly irradiated with the readout light, so that the charge is generated in the periphery of the pixel display portion. As a result, the potential of the pixel display unit does not change irrespective of the image signal, so that the contrast of the pixel display unit can be improved. Further, by etching the photoconductive layer using the metal reflection film and the metal peripheral light-shielding film as an etching mask, it is possible to make the photoconductive layer in the image display section and the peripheral section have the same film thickness, so that they are on the same plane. The beads can be dispersed to uniformly control the thickness of the liquid crystal. Therefore, it is possible to reduce the variation in the contrast of the display image, and it is possible to realize a good spatial light modulator.

In the structure of the present invention, according to a preferred structure in which a part of the metal peripheral light-shielding film is connected to the transparent conductive electrode under the photoconductive layer, a pulse voltage is applied between both transparent conductive electrodes. In addition, the metal peripheral light-shielding film and the transparent conductive electrode below the photoconductive layer are held at 0 potential. Therefore, even if the writing light is incident on the metal peripheral light-shielding film, the potential of this portion does not rise, so that it is possible to realize a spatial light modulator having a better contrast.

Further, in the constitution of the present invention, according to the preferable constitution in which the metal reflection film and the metal peripheral light-shielding film are made of two or more layers of metal, a spatial light modulator having an increased light-shielding degree and a better contrast can be obtained. Can be realized.
Particularly, according to a preferable configuration in which the bottom layer of each of the metal reflection film and the metal peripheral light shielding film is chromium and the top layer is aluminum, the adhesion between the transparent conductive electrode and the peripheral light shielding portion of the substrate is improved. The peeling of the transparent conductive electrode can be prevented. Further, according to a preferable configuration in which the lowermost layer (chrome) of the metal peripheral light-shielding film has a larger area than the uppermost layer (aluminum), a cell reaction between the transparent conductive electrode under the photoconductive layer and aluminum does not occur. Since it is not present, the lead-out electrode portion of the transparent conductive electrode does not peel off and break.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a spatial light modulator according to the present invention.

FIG. 2 is a schematic view of a projection display device manufactured using the spatial light modulator according to the present invention.

FIG. 3 is a schematic view of a holographic television device manufactured by using the spatial light modulator according to the present invention.

FIG. 4 is a sectional view showing a conventional spatial light modulator.

[Explanation of symbols]

 1, 2 Transparent Insulating Substrate 3, 4 Transparent Conductive Electrode 5 Photoconductive Layer 6 Pixel Display Area 7 Display Pixel Peripheral Area 8 Metal Reflective Film 9 Upper Metal Reflective Film 10 Lower Metal Reflective Film 11 Metal Peripheral Light-Shielding Film 12 Upper Layer Metal peripheral light-shielding film 13 Lower metal peripheral light-shielding film 14 Output light-shielding film 15, 16 Alignment film 17 Resin 18 Beads 19 Liquid crystal layer 20 Writing light 21 Reading light 22 Output light 23 Polarizer 24 Analyzer 25 Spatial light modulator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Akiyama 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor, Kuni Ogawa, 1006, Kadoma, Kadoma, Osaka Prefecture, Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A photoconductive layer, a liquid crystal layer, and a microscopic layer provided in the same plane between these layers in a region sandwiched by two transparent insulating substrates each having a transparent conductive electrode. A spatial light modulation element comprising at least a plurality of metal reflection films divided into shapes and a metal output light-shielding film located in a plane different from this plane, the pixel display including the plurality of metal reflection films. A spatial light modulation element, characterized in that a metal peripheral light-shielding film that covers the photoconductive layer is provided in the peripheral portion of the portion. 2. The spatial light modulator according to claim 1, wherein a part of the metal peripheral light shielding film is connected to the transparent conductive electrode below the photoconductive layer. 3. The spatial light modulator according to claim 1, wherein the metal reflection film and the metal peripheral light shielding film are made of two or more layers of metal. 4. The spatial light modulator according to claim 3, wherein the bottom layer of each of the metal reflection film and the metal peripheral light-shielding film is chromium, and the top layer is aluminum. 5. The spatial light modulator according to claim 4, wherein the lowermost layer of the metal peripheral light-shielding film has a larger area than the uppermost layer.