JPH05173172A - Spatial optical modulating element and its manufacture - Google Patents

Abstract

PURPOSE:To provide the spatial optical modulating element which prevents crosstalk between incident light and output light nearly completely and can record and display a high-contrast image of high resolution by equipping the spatial optical modulating element with at least a photoconductive layer, a reflecting layer, and a ferroelectric liquid crystal layer, forming the reflecting layer separately in picture element units, and also forming a light shield film between picture elements of the reflecting layer. CONSTITUTION:On a transparent insulating substrate 11, a transparent conductive electrode 12 is formed and on it, the photoconductive layer 13 formed of an amorphous silicon semiconductor, etc., having diode structure is laminated. Further, the reflecting layer 14 and an orienting film 16 are formed thereupon while divided into a fine shape in the picture element units, and the light shield film 27 is formed between the picture elements of the reflecting layer 14 on the same plane without any gap.

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 an image display device such as a holographic television or an optical arithmetic device, or an image arithmetic device, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, high-definition televisions having a large screen and high-density pixels have been developed by various methods and partially put into practical use. Above all, the development of projection-type displays using liquid crystal technology is active as an alternative to the conventional CRT method. The conventional cathode ray tube method has a problem that the luminance of the screen tends to decrease and the entire image tends to be dark when aiming at higher pixel density, and it is difficult to increase the size of the cathode ray tube itself.

Further, a projection type display device using a liquid crystal element driven by a thin film transistor is an effective method in terms of downsizing and weight reduction and low power consumption, but the aperture ratio is not large and the element itself is complicated and expensive. Is mentioned as an issue to be solved.

On the other hand, the combination with the CRT-input photo-writing type liquid crystal element has a simpler device structure and CR.
As a device combining the advantages of T and a liquid crystal element (Japanese Patent Laid-Open No. 63-109422, etc.), in recent years, a liquid crystal element having an amorphous silicon thin film as a highly sensitive light receiving layer has been used, and more than 100 inches. It is now possible to project moving images on the large screen. With regard to the liquid crystal material, it has become possible to realize a higher resolution liquid crystal light valve by using a ferroelectric liquid crystal capable of high-speed response. Further, such an optical writing type liquid crystal element is expected to be the core of the next-generation parallel arithmetic device and optical computing device by utilizing the memory characteristic and the binarization characteristic of the ferroelectric liquid crystal. ..

On the other hand, a holographic television has been attracting attention as a device capable of viewing a three-dimensional stereoscopic moving image without glasses, and a liquid crystal element is particularly expected as a rewritable hologram recording medium. Current transistor drive type liquid crystal device has a resolution of 12 to 25 (lp / m
m), and it is desired to realize a high resolution of 200 (lp / mm) or more in the future.

The spatial light modulator used in such an image display device or image arithmetic device is provided with a liquid crystal layer, a photoconductive layer, an alignment film for aligning liquid crystals, and the like, and the conventional spatial light modulator is not provided. The alignment film is generally formed uniformly over the entire device.

On the other hand, in the conventional spatial light modulator, there has been proposed one in which minute electrodes are formed at the interface between the liquid crystal layer and the photoconductive layer (Japanese Patent Laid-Open Nos. 62-40430 and 62-169120). Publication). This is a microelectrode provided in place of the reflective layer of the multilayer dielectric thin film, and features are (1) easy manufacture, (2) no incident angle dependency, and (3) It has a high light reflectance.

When a spatial light modulator is used in a projection display, a high quality television image can be obtained due to its features of high aperture ratio and sharp pixel shape. In such a spatial light modulator, a light-shielding film is provided to prevent the incident light to be modulated and the output light from overlapping, and particularly when the light-shielding film is provided between the photoconductive layer and the reflective layer, the electrical insulation property is provided. On the other hand, when the light-shielding film is directly provided on the transparent electrode, it need not be an electrically insulating film.

[0009]

However, in the structure of the conventional spatial light modulator disclosed in Japanese Patent Laid-Open No. 62-40430, a uniform light shielding film is electrically insulated between the photoconductive layer and the reflective layer. It is relatively easy to manufacture because it is made of a conductive material, but since an insulating layer is interposed between the photoconductive layer and the metal reflective layer, charge accumulation in the insulating layer causes the photoconductive characteristics during driving. There is a problem that the switching characteristics are deteriorated.

On the other hand, in the structure of the conventional spatial light modulator disclosed in Japanese Patent Laid-Open No. 62-169120, a light-shielding film does not exist in a portion corresponding to a pixel, and the structure shown in FIGS. As shown, there is no intervening electrical insulation layer. However, since separate photolithography processes are required for the electrode forming process and the light-shielding film forming process, there is a problem that high precision is required for the alignment and it is difficult to form high density pixels. For example,
To achieve a resolution of 100 (lp / mm), several μm
High-precision alignment called order is required.

In order to solve the above problems, the present invention provides a spatial light modulator having a liquid crystal layer, a photoconductive layer, a reflective layer, etc., in which an alignment film is formed only on the reflective film separated for each pixel. With the above structure, high-density pixel pattern formation is realized, and it is an object of the present invention to provide a spatial light modulator capable of faithfully displaying high-density information.
It is an object of the present invention to provide a method for manufacturing a spatial light modulator that can form an alignment film and a reflective film in the same pixel pattern by a single photolithography process and can easily form a light shielding film.

[0012]

In order to achieve the above object, the spatial light modulator of the present invention comprises at least a photoconductive layer,
A spatial light modulator comprising a reflective layer and a ferroelectric liquid crystal layer, wherein the reflective layer is formed separately for each pixel, and a light-shielding film is formed between the pixels of the reflective layer. Characterize.

In the above structure, it is preferable that the reflection layer is an aluminum metal thin film and the light shielding film is a film containing aluminum oxide. Further, in the above configuration,
It is preferable that the light-shielding film is a film containing aluminum oxide and a metal is deposited on the surface thereof.

Further, in the method for manufacturing a spatial light modulator of the present invention, a metal reflective layer is uniformly formed on the photoconductive layer, and then an alignment film is uniformly formed on the metal reflective layer. , Forming a resist film on the alignment film in a pixel pattern, subsequently removing the alignment film located between the pixels, and then using an anodic oxidation method,
It is characterized in that the metal reflective layer located between the pixels is changed to an oxide insulating layer to form a light shielding film, and then the resist film is removed.

[0015]

According to the above structure, the spatial light modulator including at least the photoconductive layer, the reflective layer and the ferroelectric liquid crystal layer, wherein the reflective layer is formed separately for each pixel, Since the light-shielding film is formed between the pixels, the reflective layer corresponding to the pixel is in direct contact with the photoconductive layer, and the insulating layer is interposed between the reflective layer and the photoconductive layer. Since there is no voltage loss and charge accumulation, stable operation is realized, and since the reflective layer and the light shielding film are formed on the same plane without any gap, crosstalk between the incident light and the output light is prevented. It can be prevented almost completely.

Further, since the reflection layer is an aluminum metal thin film and the light-shielding film is a film containing aluminum oxide, a reflection layer having a high light reflectance can be easily formed, and an anodic oxidation method or the like can be used. By using the above metal oxidation treatment, it is possible to easily form the light-shielding film on the same plane without a gap simply by oxidizing the metal thin film with the pixel pattern.

Further, since the light-shielding film is a film containing aluminum oxide, and the metal is deposited on the surface of the film, the light-shielding film is colored and the light absorption rate is improved, and the light-shielding performance of the light-shielding film is good. Becomes

According to the method of manufacturing a spatial light modulator of the present invention, a metal reflective layer is uniformly formed on the photoconductive layer,
Further, after forming an alignment film uniformly on the metal reflection layer, a resist film is formed on the alignment film in a pixel pattern, then the alignment film located between the pixels is removed, and then the anode film is formed. By using an oxidation method, the metal reflection layer located between the pixels is changed to an oxide insulation layer to form a light-shielding film, and then the resist film is removed, whereby the pixel pattern of the alignment film and the pixel pattern of the reflection layer are changed. It is possible to easily obtain a spatial light modulator in which the reflection layer and the light-shielding film are almost completely aligned and are formed on the same plane without a gap.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an embodiment of the spatial light modulator of the present invention. Transparent insulating substrate 1 such as glass
1, a transparent conductive electrode 12 such as ITO or SnO _x is formed, and a photoconductive layer 13 such as an amorphous silicon semiconductor having a diode structure is laminated on the transparent conductive electrode 12.

The material used for the photoconductive layer 13 is, for example, CdS, CdTe, CdSe, ZnS, ZnSe, Ga.
Compound semiconductors such as As, 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) semiconductor such as polycrystalline or amorphous semiconductor, or (1) phthalocyanine pigment (hereinafter referred to as “P
abbreviated as “c”), for example, metal-free Pc, XPc (X = Cu,
Ni, Co, TiO, Mg, Si (OH) _2, etc.), Al
ClPcCl, TiOClPcCl, InClPcC
1, InClPc, InBrPcBr, etc., (2) Azo dyes such as monoazo dyes and disazo dyes, (3) Penylene anhydrides, Penylene pigments such as penylene acid imides, (4) Indigoid dyes, (5) Quinacridone pigments, (6) Polycyclic quinones such as anthraquinones and pyrenequinones, (7) Cyanine dyes, (8) Xanthene dyes, (9) Charge transfer complexes such as PVK / TNF, (10) Formed from pyrylium salt dyes and polycarbonate resins There are organic semiconductors such as eutectic complexes and (11) azurenium salt compounds.

Amorphous Si, Ge, Si
_1-xC_x, Si_1-xGe_x, Ge_1-xC_x(Hereinafter, a-
Si, a-Ge, a-Si_1-xC_x, A-Si_1-xGe
_x, A-Ge _1-xC_xAbbreviated as) to the photoconductive layer 13
When used, hydrogen or halogen elements may be included.
First, use oxygen or nitrogen to reduce the dielectric constant or increase the resistivity.
You can include it. In addition, p-type impurities are used to control the resistivity.
Is an element such as B, Al, or Ga, or is an n-type impurity.
Elements such as P, As, and Sb may be added.

In this way, the amorphous materials doped with impurities are laminated to form junctions of p / n, p / i, i / n, p / i / n, etc., and the depletion layer is formed in the photoconductive layer 13. May be formed to control the dielectric constant, dark resistivity or operating voltage polarity. Not only such an amorphous material, but two or more kinds of the above materials are laminated to form a heterojunction, and the photoconductive layer 13 is formed.
A depletion layer may be formed inside. In addition, the photoconductive layer 13
The film thickness of is preferably in the range of 0.1 μm to 10 μm.

On the photoconductive layer 13, a reflective layer 14 such as a metal thin film of aluminum, chromium, titanium or the like or a multilayer dielectric thin film, and a polymer thin film such as nylon or polyimide for orienting liquid crystal or SiO ₂ orthorhombic. Alignment film 16 such as vapor deposition film
Are formed by being divided into minute shapes on a pixel-by-pixel basis.
In particular, as the alignment film having excellent electric characteristics, for example, polyimide disclosed in Japanese Patent Application No. 3-1145 and represented by the general formula (Formula 1) can be used.

[Chemical 1]

Light-shielding films 27 are formed in the same plane between the pixels of the reflective layer 14 without any gap. The alignment film 1
No. 5 is formed so that the orientation of the ferroelectric liquid crystal molecules is parallel to the layer direction, and the thickness thereof is 1000 angstroms or less, and particularly preferably 100 angstroms or less. Further, the thickness of the reflective layer 14 is preferably in the range of 100 to 2000 angstroms, particularly 500 to 150 angstroms.
The range of 0 Å is particularly preferred.

The cell thickness of the ferroelectric liquid crystal layer 16 is determined by the spacers 17 such as dispersed resin beads. In particular, in order to increase the contrast of output light, the thickness of the ferroelectric liquid crystal layer 16 is about 2 μm in the case of the transmissive spatial light modulator, and about 1 μm in the case of the reflective spatial light modulator.
It is preferable to set to μm. Further, the material of the ferroelectric liquid crystal layer 16 is preferably a chiral smectic C liquid crystal which is a ferroelectric liquid crystal.

Similarly, a transparent conductive electrode 19 such as ITO or SnO _x is formed on a transparent insulating substrate 20 such as glass, and an alignment layer 18 similar to the alignment film 15 is formed on the entire surface thereof. Are formed uniformly.

Next, the operation of the spatial light modulator will be described. Incident light 21 is emitted from the substrate side on which the photoconductive layer 13 is laminated.
The pattern information is recorded by. On the opposite side of the element, the reading light 22 is emitted through the polarizer 23,
Output light 2 modulated according to the recorded pattern information
4 is output via the analyzer 25. The polarizer 23
And the polarization directions of the analyzer 25 are orthogonal to each other.

FIG. 3 is a cross-sectional view for explaining the steps of one embodiment of the method for manufacturing a spatial light modulator of the present invention. In the step (a), an ITO transparent conductive electrode 12 is formed on the glass substrate 11 by a sputtering method, and then an amorphous silicon photoconductive layer 13 having a pin diode structure is formed by a plasma CVD method. in addition,
An aluminum thin film reflection layer 14 is formed by an electron beam evaporation method, and then an alignment film 15 for aligning a ferroelectric liquid crystal.
As a coating, a thin film of a polyimide polymer is formed.

In step (b), the resist film 30 is applied to a desired pixel pattern and exposed. The portion where the resist film 30 is formed corresponds to the pixel region,
The portion where the resist film 30 is removed becomes a region between pixels.

In step (c), the alignment film 15 located between the pixels is removed by oxygen plasma asher. Through this step, the alignment film 15 is divided into pixel units, and the divided alignment film 15a is formed.

In step (d), the aluminum layer between the pixels is made into an insulating aluminum oxide layer by anodizing a part of the reflective layer 14 located between the pixels while leaving the resist film 30. Reform.

An example of the anodizing treatment will be described below. (C)
The whole substrate obtained in the step is dipped in, for example, a 15% sulfuric acid aqueous solution, the transparent conductive electrode 12 is used as an anode electrode, and the separately immersed carbon electrode is used as a cathode electrode, and the current density is 10 m.
Constant current electrolysis of A / cm ² is performed. The aqueous solution temperature is stabilized within the range of 20 ° C to 25 ° C.

By such anodizing treatment, the aluminum layer between the pixels is modified into an anodized aluminum layer,
On its surface, fine holes called bores having a diameter of 100 angstroms or less, which are peculiar to the anodic oxide film, are formed. The anodized film can be colored by depositing a metal such as nickel or copper in the bore. For example,
By dipping the entire substrate in a nickel sulfate electrolytic solution and applying a voltage, nickel is deposited in the bore and colored. Finally, the whole substrate is immersed in pure water for about 30 minutes to seal the hydrate. By this step, the aluminum separating / reflecting film 15 separated in pixel units and the light shielding film 27 located between pixels are formed.

In step (e), after removing the resist film 30, the alignment film 15 is subjected to an alignment treatment. In order to obtain uniform orientation, it is preferable to rub the surface of the polymer film with a cloth such as nylon when carrying out the orientation treatment. Further, as the alignment film 15, SiO _{2 formed} by the oblique vapor deposition method is used.
Rubbing is not required when using a film.

After the step (e), the spatial light modulator shown in FIG. 1 can be manufactured by laminating the spacers 17 together with the dispersed glass substrate 20 on the opposite side.

Specific examples of the spatial light modulator and the method for manufacturing the same according to the present invention will be described in detail below. (Example 1) In this example, the manufacture of the spatial light modulator shown in FIG. 1 will be described. As the transparent insulating substrate 11, a 55 mm × 45 mm × 1.1 mm glass substrate was used, and ITO having a thickness of 0.1 μm was formed thereon by a sputtering method to form the transparent conductive electrode 12. Next, by the plasma CVD method, p / i / with a thickness of 2.2 μm is formed.
Photoconductive layer 13 having an effective area of 35 mm × 35 mm, which is obtained by stacking amorphous silicon films having an n-diode structure.
Formed. The reflective layer 1 is formed on the effective area of the photoconductive layer 13.
4 as an aluminum thin film by electron beam evaporation method
It was formed to a thickness of 500 Å.

Subsequently, as the alignment film 15, a polyamic acid, which is a precursor of polyimide, is applied to the reflective layer 1 by a spinner.
4 was applied to the surface of No. 4 in a thickness of about 100 angstroms or less, and the whole substrate was placed in a heat treatment furnace and subjected to heat treatment at 230 ° C. for 1 hour to form a polyimide film by imidizing the polyamic acid.

Next, a process of dividing the alignment film 15 and the reflective layer 14 into pixel units will be described. The size of one pixel is 20 μm
1000 pixels x 1 with a pixel pitch of 25 μm at x 20 μm
After the resist film 30 was formed by coating with a pixel pattern of 000 pixels, the substrate was heated to 150 ° C. and the alignment film located between the pixels was removed by an oxygen plasma asher for 10 minutes.

This substrate was dipped in a sulfuric acid aqueous solution stabilized at 22 ° C. to 24 ° C., a constant current of 12 mA / cm ² was applied for 20 seconds using the transparent conductive electrode 12 as an anode,
The portion of the transparent conductive electrode 12 not coated with the resist film 30 was modified into a light shielding film 27 of an aluminum oxide layer.
Next, in order to increase the light absorption rate of the light shielding layer 27,
While immersing the whole substrate in nickel sulfate solution, AC 10V
By conducting constant voltage electrolysis with, nickel was deposited in the bore on the surface of the anodic oxide film, and the light shielding film 27 was colored black.
After that, the resist film 30 was removed.

On the other hand, as the transparent insulating substrate 20 on the opposite side, a glass substrate similar to the transparent insulating substrate 11 was used, and an ITO transparent conductive electrode 19 similar to the transparent conductive electrode 12 was formed thereon. Further, an alignment film 18 made of a polyimide film was laminated in the same manner as the alignment film 15, and the surface was rubbed with a nylon cloth in a certain direction to perform an alignment treatment.

Next, the formation of the ferroelectric liquid crystal layer 16 will be described. In order to realize a ferroelectric liquid crystal layer having a thickness of about 1 μm, beads having a diameter of 1 μm dispersed in isopropyl alcohol are sprayed on the surface of the alignment film 15 on one side of the substrate, and then the transparent insulating substrate 11 is formed. , 20 was coated with a UV curable resin and adhered to each other to prepare a liquid crystal cell. After injecting a ferroelectric liquid crystal (trade name "ZLI-3654", manufactured by Merck & Co., Inc.) into this liquid crystal cell in a vacuum, a temperature higher than the phase transition temperature (62 ° C) of the ferroelectric liquid crystal in order to obtain uniform alignment. Then, the film was returned to room temperature at a slow cooling rate of 1 ° C./minute or less and reoriented.

Next, characteristic evaluation of the obtained spatial light modulator
Will be described. Transparent conductive electrode of spatial light modulator 1
AC voltage is applied between 12 and the transparent conductive electrode 19.
In this state, the operation was confirmed by using white light as the incident light 21.
As a result, the ratio of output light intensity to incident light intensity is
If the light amount loss of the polarizer 23 and the analyzer 25 is excluded, it is 80
% To 90%, and the incident light intensity is several μW /
cm ²If it is above, the rising of the output light is observed,
It was confirmed that the operation is sufficient even if the light intensity is small.

FIG. 4 is a graph showing changes in output light intensity with respect to incident light intensity under a constant voltage. From the graph, it is understood that the spatial light modulator can be used as a projection display having continuous gray scales because halftone output is possible in a low light illuminance region. It was confirmed that the optical input / output characteristics did not change even after continuous driving, and the memory state after the driving was stable was maintained for at least one month or more. The output light contrast ratio is also 25
The spatial light modulator having a good value of 0: 1 or more and having a small amount of leaked light and a good light shielding performance could be obtained.

Next, the characteristic evaluation of the obtained spatial light modulator will be described. FIG. 7 is a schematic configuration diagram of a projection display device used for evaluation of the spatial light modulator. As a means for performing optical writing to the spatial light modulator 1, the vertical is 48
A CRT display 43 having a resolution of 0 pixels and a width of 650 pixels was used. The readout light is emitted from the light source 40 of the metal halide lamp, and the condenser lens 41
The light is condensed by the laser beam and is irradiated onto the spatial light modulator 1 via the polarization beam splitter 42. The output image is reflected by the polarization beam splitter 42, enlarged by the lens 44, and formed on the screen 45. When each pixel on the screen of the CRT display 43 is written in the divided pixels of the spatial light modulator 1, the pixels are converted into rectangular pixels on the screen 45.

As a result, an image having a large aperture ratio of 80% and enlarged to a size of 100 inches is displayed on the screen 4.
5 gives a bright image with an illuminance of 2000 lumens. Further, it was confirmed that the image contrast was 250: 1 and the resolution was 650 TV lines in the vertical direction. This means that the spatial light modulator 1 has a resolution of 50 (lp / mm).

When a moving image was output, there was no afterimage with respect to the movement of the video rate, and a clear high-luminance image was obtained. Further, in order to obtain a color image, three sets of combinations of the CRT display 43 corresponding to the three primary colors of RGB and the spatial light modulation element 1 are prepared and synthesized on the screen, so that a good color image is finely reproduced, Moreover, there was almost no leakage light in the area between pixels, and a light blocking performance of 1/10 ⁴ or less of the maximum illuminance in the pixel area was obtained.

Next, the results of characteristic evaluation of the spatial light modulator as a holographic television device will be described. FIG. 8 is a schematic configuration diagram of a holographic television device used for evaluation of the spatial light modulator. As means for performing optical writing to the spatial light modulator shown in Example 2, He-
The coherent light from the Ne laser 51 is reflected by the half mirror 5.
The light beam is split into two, and one light beam is emitted to the CCD 58 through the subject 50 through the lens 56, and the other light beam passes through the beam expander including the lenses 54 and 55, and is referred to the CCD 58 through the half mirror 57. It is irradiated as light, and an interference fringe pattern is formed on the image pickup surface of the CCD 58. The image data of the interference fringe pattern is converted into an electric signal, transferred to the CRT 65 and reproduced.

The image data of the interference fringe pattern reproduced on the screen of the CRT 65 is optically written and recorded in the spatial light modulator 1 by the lens 66. The spatial light modulator 1 has a pixel pattern of 8 μm square pixels having a pitch of 10 μm and 3200 × 3200 = about 10 ⁷ pixels.

The He-Ne laser 61 is used to read out the image.
The coherent light from the laser beam passes through the beam expander composed of the lenses 62 and 63, is irradiated onto the spatial light modulation element 1 via the polarization beam splitter 64, and the modulated output light passes through the polarization beam splitter 64 and passes through the lens 67. , A stereoscopic image in the reflection mode is observed with the naked eye 68.

As a result, the stereoscopic image displayed in real time can be reproduced and the movement of the subject 50 can be observed by the real time hologram. The aperture ratio is 64%,
It was confirmed that the image contrast was 200: 1 and the resolution was 100 lines / mm.

[0051]

As described in detail above, the spatial light modulator of the present invention is a spatial light modulator including at least a photoconductive layer, a reflective layer, and a ferroelectric liquid crystal layer, and the reflective layer is provided for each pixel. Since the light-shielding film is formed separately between the pixels of the reflective layer, crosstalk between the incident light and the output light can be almost completely prevented, so that the contrast is high and Images with high resolution can be recorded and displayed.

Further, since the reflection layer is an aluminum metal thin film and the light-shielding film is a film containing aluminum oxide, the light reflectance of the reflection layer is high and, moreover, metal oxidation treatment such as anodic oxidation is used. Since the light-shielding film can be easily formed on the same plane as the reflective layer without a gap, it is possible to obtain a spatial light modulator having a low manufacturing cost.

Further, since the light-shielding film is a film containing aluminum oxide and the metal is deposited on the surface of the film, the light-shielding film is colored and the light absorption rate is improved, and the light-shielding performance of the light-shielding film is good. Therefore, an image with higher contrast can be obtained.

Further, in the method for manufacturing a spatial light modulator of the present invention, after the metal reflective layer is uniformly formed on the photoconductive layer, the alignment film is uniformly formed on the metal reflective layer. , Forming a resist film on the alignment film in a pixel pattern, subsequently removing the alignment film located between the pixels, and then using an anodic oxidation method,
By changing the metal reflective layer located between the pixels to an oxide insulating layer to form a light-shielding film, and then removing the resist film, the pixel pattern of the alignment film and the pixel pattern of the reflective layer almost completely match, Furthermore, since the reflective layer and the light-shielding film are formed on the same plane without a gap, crosstalk between the incident light and the output light is small, and a spatial light modulator with high contrast can be easily obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a spatial light modulator of the present invention.

FIG. 2 is a cross-sectional view for explaining a process of an embodiment of the method for manufacturing the spatial light modulator of the present invention.

FIG. 3 is a graph showing changes in output light intensity with respect to incident light intensity of the spatial light modulator of the present invention.

FIG. 4 is a schematic configuration diagram of a projection display device used for evaluation of a spatial light modulator.

FIG. 5 is a schematic configuration diagram of a holographic television device used for evaluation of a spatial light modulator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spatial light modulator 11, 20 Transparent insulating substrate 12, 19 Transparent conductive electrode 13 Photoconductive layer 14 Reflection layer 14a Separation reflection layer 15, 18 Alignment film 15a Divided alignment film 16 Ferroelectric liquid crystal layer 17 Spacer 21 Incident light 22 Read-out light 23 Polarizer 24 Output light 25 Analyzer 27 Light-shielding film 30 Resist film 40 Light source 41 Condenser lens 42 Polarizing beam splitter 43 CRT display 44 Lens 45 Screen 51, 61 He-Ne laser 52, 57 Half mirror 53 Mirror 54, 55, 56, 62, 63, 66, 67 lens 58 CCD 64 polarizing beam splitter 65 CRT 68 naked eye

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

Claims (4)

[Claims] 1. A spatial light modulator comprising at least a photoconductive layer, a reflective layer and a ferroelectric liquid crystal layer, wherein the reflective layer is formed separately for each pixel, and the pixel of the reflective layer is formed. A spatial light modulator comprising a light-shielding film formed between the two. 2. The reflective layer is an aluminum metal thin film,
The spatial light modulator according to claim 1, wherein the light shielding film is a film containing aluminum oxide. 3. The spatial light modulator according to claim 2, wherein the light-shielding film is a film containing aluminum oxide, and a metal is deposited on the surface thereof. 4. A metal reflective layer is uniformly formed on the photoconductive layer, an alignment film is uniformly formed on the metal reflective layer, and a resist film is formed on the alignment film to form pixels. Then, the alignment film located between the pixels is removed, and then the metal reflection layer located between the pixels is changed to an oxide insulating layer by using an anodic oxidation method to form a light shielding film. A method for manufacturing a spatial light modulator, which comprises forming and then removing the resist film.