JPH04130420A - Optical writing type liquid crystal light valve - Google Patents

Abstract

PURPOSE:To improve resolution by constituting a light reflection layer of a dielectric mirror formed by alternately laminating many layers of compd. layers of Si and Ge and SiO2 layers. CONSTITUTION:The light reflection layer is constituted of the dielectric mirror formed by alternately laminating many layers of the comptd. layers 23 of the Si and Ge and the SiO2 layers. Then, the specific resistance 10<9> to 10<10> of the dielectric mirrors required for optimum driving of the liquid crystal light valve from the specific resistance (10<11> to 10<12>OMEGA.cm) of the ferroelectric liquid crystal and the specific resistance of a-Si:H(10<5> when bright and 10<10> to 10<11>OMEGA.cm when dark) of a photoconductive layer 15 is attained. The resolution is improved in this way.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical writing type liquid crystal light used in intermediate recording media of optical printers, image display devices, optical shutters, image processing devices, optical information processing systems, etc. It concerns valves.

[Summary of the invention]

The present invention is a light-emitting device that combines a high-temperature photoconductive layer that exhibits high resistivity in the dark and high conductivity when irradiated with light, and a dielectric mirror as a light-reflecting layer that has moderate conductivity and high reflectance. This invention relates to a writing type liquid crystal light valve.

As a photoconductive layer, the temperature (
Hydrogenated amorphous silicon (a-3i:H), etc., which is stable with respect to ~200-c), has a high specific resistance in the dark, and has a high photoconductivity when irradiated with light, provides good characteristics. As the light reflection layer, a compound layer of Si and Ge and a SiOz
When using a dielectric mirror in which multiple layers of .jii and .
The composition is 1≦x≦0.6. Furthermore, a compound layer, S
The thickness d of each layer of the IOz layer is d, assuming a predetermined wavelength λ, material refractive index n, and film thickness d so as to form a λ/4 film.
=J/4n.

By using the light valve according to the present invention, it is possible to provide an optical writing type image projection device that can display high-definition images, has a fast writing speed, and can display moving images.

[Prior art] In research on optical information processing and optical pattern recognition, many optical writing type liquid crystal light valves have been used to convert incoherent optical information into coherent optical information and to perform spatial light modulation of optical information. has been studied.

In order to improve resolution, contrast, and response speed, the above-mentioned optical writing type liquid crystal light valve uses ferroelectric liquid crystal, TN liquid crystal, SmA liquid crystal, etc. for the liquid crystal layer.
Many attempts have been made to use hydrogenated amorphous silicon (hereinafter referred to as a-5i:H), a chalcogenide compound such as CdSe, or an organic photoconductive material as the photoconductive layer.

In particular, Si/SiO□ multilayer film mirrors are used as dielectric mirrors that have high reflectance and electrical characteristics that suit the parameters of the liquid crystal drive circuit in optical writing type liquid crystal light valves that read out optical information. It has been.

In addition, S i Ot / T i O2, Z n
Research has been attempted to form dielectric mirrors by combinations such as S/M gF2.

[Problem to be solved by the invention] However, the above-mentioned conventional S i / S I
When a dielectric mirror is made with O2, the specific resistance in the in-plane direction is too low, so when light is irradiated, a voltage is applied to the entire surface, and depending on the degree, the image may be blurred, uneven, or distorted. There was a problem that the resolution could not be increased because it could not be written.

Furthermore, a semiconductor junction between a-3i:H, which is a photoconductive film, and a dielectric mirror also has the problem of exhibiting characteristics similar to those described above.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the optical writing type liquid crystal light valve according to the present invention has a light reflecting layer made of a multilayer consisting of a Si and Ge compound layer and a Sin layer alternately. It is composed of stacked dielectric mirrors, and has a composition of 0.01≦x≦0.6, where the molecular formula of the compound is SI+-xGe,l.

Furthermore, the dielectric mirror has a multilayer stacked structure using compound layers having at least two types of Ge element concentrations, or the Ge element concentration of each compound layer decreases from the photoconductive layer side to the liquid crystal alignment layer side. It has a multilayered structure with a concentration gradient.

Furthermore, a structure was adopted in which an insulating layer was inserted between the dielectric mirror and the photoconductive layer.

[Function] According to the optical writing type liquid crystal light valve of the present invention having such a configuration, a compound layer of Si and Ge,
The molecular formula of the compound layer is 5j.
By configuring the dielectric mirror with a composition of 0.1≦x≦0.6 when l-XGeX, the specific resistance of the ferroelectric liquid crystal (10''-10'!Ω・C11) and the photoconductive layer are a
-3i:H specific resistance (10'Ω・in bright and dark conditions, 1010 to 10Ω・cJ in dark conditions), the specific resistance of the dielectric mirror required to optimally drive the liquid crystal light valve is 10
'~1010 has been achieved.

In addition, the dielectric mirror is made of a compound layer of Si and Ge and Si0
By forming a multilayer structure in which the G layers are alternately stacked, the light reflection characteristics of the dielectric mirror can be enhanced, and the light transmittance can be suppressed to almost 0% due to the light absorption of the compound layer of Si and Ge.
A dielectric mirror is realized which has a high visible light reflectance and whose photoconductive layer is less affected by readout light.

Furthermore, Ge of each of the compound layers constituting the dielectric mirror is
By setting the element concentration to a concentration gradient that decreases from the photoconductive layer side to the liquid crystal alignment layer side, the usable wavelength band can be widened, and by using compound layers with at least two types of Ge element concentrations, By making it a multilayer laminated structure,
Each compound layer has reflection characteristics centered around different wavelength bands, and these overlap to widen the usable wavelength band.

Furthermore, by providing an insulating layer between the photoconductive layer and the dielectric mirror, the semiconductor junction between the photoconductive layer and the dielectric mirror can be avoided, and the specific resistance in the in-plane direction due to the semiconductor junction can be reduced. Preventing the decline.

Here, each layer of the compound layer and the SiO2 layer constituting the dielectric mirror is preferably formed as λ/4, and if the predetermined wavelength is λ and the refractive index of each layer is n, then the thickness d of each layer is as follows:
It is necessary to form it as d=λ/4n.

[Example] Figure 1 shows a combination of a highly sensitive light guide layer according to the present invention that exhibits high abrasive resistivity when dark and high conductivity when irradiated with light, and a dielectric mirror that has moderate conductivity and high reflectance. FIG. 2 is a cross-sectional view showing the structure of an optical writing type liquid crystal light valve.

In this embodiment, first, a transparent glass substrate is prepared as the transparent substrate 118.11b, and the transparent electrode layers 12a, 12b are
A polar layer of ITOI Bright 1 was formed on the surface, and a non-reflective coating layer 18 was further formed on the outer surface of the transparent substrate 11b.

Further, on the optical writing side transparent electrode layer 1.2a, S
i Discharge and decompose gas mainly consisting of F4 to a thickness of 2 to 3μ
A photoconductive layer 15 was formed by forming an intrinsic a-3iH of m.

Further, Si-G is formed on the photoconductive layer 15 via the insulating layer 22.
A dielectric mirror 17 consisting of a multilayer stack of a compound layer of e and a SiO layer was formed. Silicon monoxide (Si0) was deposited on the dielectric mirror 17 and the transparent electrode on the projection side to a thickness of 200 OA using a film thickness meter set at an angle of 82 degrees to the normal direction of the substrate and in the normal direction of vapor deposition. The liquid crystal alignment layers 13a and 13b were formed by diagonal gluing. The transparent substrates 11a and llb have alignment layers 13a and 13b facing each other, and have a diameter of 1.5 μm.
Spacer 19 from adhesive with m glass fiber added
A gap was controlled and formed through the ferroelectric liquid crystal layer 14 to sandwich the ferroelectric liquid crystal layer 14 therebetween. The encapsulated ferroelectric liquid crystal composition contains 4((4″-octyl)phenyl)benzoic acid (3″-fluoro, 4″-octyloxy)phenyl ester and 4-((4″-octyl)phenyl) as an ester-based SmC liquid crystal mixture. '
-octyloxy) benzoic acid (3"-fluoro0.4" octyloxy) phenyl ester mixed in a ratio of 1=1, and as an optically active substance, 5-octyloxynaphthalenecarboxylic acid and 1'-cyanethyl A ferroelectric liquid crystal composition was used by adding 25% by weight of ester.

Next, the configuration of each embodiment of the dielectric mirror 17 in the optical writing type liquid crystal light valve according to the present invention shown in FIG. 1 will be explained based on the drawings.

FIG. 2 is a configuration diagram showing a first embodiment of a dielectric mirror according to the present invention. About 942 people and Si+-
This is a structure in which 600 layers of x CeX23 are alternately repeated 7 times, and then 600 layers of S I + -X G e z23 are formed thereon.

In addition, the photoconductive layer 15 a-3i:H and SiCeX
23, an insulating layer 22 of SiO□ was sandwiched.

As a result, the specific resistance in the in-plane direction was too low due to the semiconductor junction between a-5i:H and the dielectric mirror 17, and it was possible to prevent voltage from being applied to the entire surface when irradiated with light. This time, we used Sing for the insulating layer, but we also used G e Oz.
, T i 02, A1. It is also possible to use an insulating layer such as O.

FIG. 3 shows the characteristics of resistivity with respect to the composition ratio of the dielectric mirror according to the present invention.
cm, the specific resistance of a-3iHO is 105Ω・in light and darkness.

, 1010~1°1Ω・in the dark. To optimally drive the liquid crystal light valve, the specific resistance of the dielectric mirror is 1.
Must be 09~1o10Ω, c. s on the horizontal axis
The composition ratio X of i, -e Ge8 was taken, and the specific resistance at that composition was taken on the vertical axis. From the figure, the specific resistance of the dielectric mirror is 109
~10111Ω・. When the composition ratio X is 0.25 to 0
．． It turned out to be between 50 and 50. This time, the value of X was as above, but Si, Gex
The composition ratio was set to 0.1≦x≦0.6 because the O resistivity varies in the range between line A and B&l in the figure depending on the deposition conditions.

FIG. 4 shows the optical characteristics of the dielectric mirror of the first embodiment shown in FIG. 2. From the figure, the visible light reflectance is 90.
%, and the visible light transmittance was almost 0%. The reason why the reflectance is 90% but the transmittance is almost 0% is Si and G.
This is due to the light absorption of the compound layer e. It can be seen that the material has a high visible light reflectance, and has the property of transmitting only the writing light and reflecting the reading light.

However, since 5i-Ge, which is a high refractive index material of the present invention, contains Ge, it absorbs a lot of light, resulting in a substantial decrease in light reflectance.

FIG. 5 is a configuration diagram showing a second embodiment of a dielectric mirror according to the present invention. Dielectric mirror 17 in this embodiment
About 580 people and S
iO
A multilayer film 30 formed to the same thickness as G eg 25,
On top of that, about 942 SiO228 people and S of x=0.19
It has a structure in which a multilayer film 31 is formed by repeating 1t-X Gex 29 four times by about 600 people alternately.

Furthermore, an insulating layer of 5iOz22 was sandwiched between the a-3i:H photoconductive layer 15 and the multilayer film 30. As a result, the a-3i:H photoconductive layer 15 and the dielectric mirror 17
Due to the semiconductor junction, the specific resistance in the in-plane direction is too low, and it was possible to prevent the phenomenon in which a voltage would be applied to the entire surface when irradiated with light. This time, we used SiC2 for the insulating layer, but we also used Ge0
It is also possible to use an insulating layer such as MgFz or MgFz.

6 shows the optical characteristics of the dielectric mirror of the second embodiment shown in FIGS. 6 and 5. FIG. From the figure, the visible light reflectance is 95%.
The visible light transmittance was 0% and the 0 reflectance was 95%.
However, the reason why the transmittance is 0% is because the light absorption of Ge is large, and the dielectric mirror of this example configured in this way has a visible light reflectance that is lower than that of the dielectric mirror of the first example. It can be seen that it has the ability to transmit only the writing light and reflect the reading light.

FIG. 7 is a configuration diagram showing a third embodiment of a dielectric mirror according to the present invention. The dielectric mirror 17 according to this embodiment is
An insulating layer 5iOx2 is formed on the photoconductive layer 15 a-3i:H.
Approximately 942 people and 34. −
, Ge, is repeated 7 times for approximately 600 people, and then 5i
In this example, the Ge composition X of S++-Xcex is x = 0.45 for the first layer and the third layer 32, and x = 0.45 for the fifth layer and the seventh layer 32.
3 is X-0,40, and the 9th layer and the 11th layer 34 are x = 0.
30, the 13th layer and the 15th layer 35 had a structure where x=0.25.

In this example, 5i1 from the side 13a close to the liquid crystal alignment layer.
-The composition of the XGeX layer was changed two at a time, but it does not matter how many layers the composition is changed, as long as the structure has a gradient of element concentration so that the element concentration is lower on the side closer to the liquid crystal alignment layer, it meets the specifications. It doesn't matter how you combine them.

FIG. 8 shows the optical characteristics of the dielectric mirror of the third embodiment shown in FIG. 7. Visible light reflectance is 95 compared to Kuni.
%, and the visible light transmittance was approximately 0%. The reason why the reflectance is 95% but the transmittance is almost 0% is Si and G.
This is because there is light absorption in the compound layer with e. Thus, it can be seen that the visible light reflectance is higher than that of the dielectric mirror of the first embodiment, and that it has the characteristic of transmitting only the writing light and reflecting the reading light.

As mentioned above, the dielectric mirror in each example was produced by vacuum evaporation, but other film-forming methods such as sputtering,
It can also be produced by a method such as a CVD method.

When writing image information, etc. to the optical writing type liquid crystal light valve according to the present invention using an LD or LED, first, the entire surface of the liquid crystal light pulp is irradiated with light, and a DC voltage sufficiently higher than the threshold voltage is applied. or, if no light irradiation is performed, apply a DC bias voltage that is sufficiently larger than the dark threshold voltage to align the ferroelectric liquid crystal to a stable state in one direction and store it in that state. carry out the process.

Next, without light irradiation, a DC voltage of opposite polarity is applied, which is below the threshold voltage during dark and above the threshold (i voltage) during light irradiation, and an optical writing device such as a laser beam or LED is applied. The image information to be projected and displayed is written using light.The photoconductive layer used here has a thickness of 700 to 850 nm.
Because it has a sufficiently high sensitivity to light with a wavelength of m,
For example, when irradiated with a semiconductor laser having a center wavelength of 780 nm, the photoconductive film 15 exposed to light generates carriers and enters a low resistance state, and the applied bias voltage is applied to the liquid crystal layer in the form of resistance division. Excite liquid crystal molecules. The region that is not irradiated with light maintains a high resistance, and therefore, almost no voltage is applied to the liquid crystal molecules, so the liquid crystal molecules are not excited, and as a result, the alignment direction of the liquid crystal molecules in the light irradiated area and the non-light irradiated area is changed. It will be stored in memory with different values.

The image information written in this way is reflected by the reflective layer when linearly polarized projection light that has passed through the polarizer is projected onto the screen after passing through the analyzer. When the contrast ratio between the bistable states was measured using a polarizing plate with a degree of polarization of 99.9% and a single transmittance of 38% as a polarizer and an analyzer, it showed an extremely high value of 400:1 or more. In liquid crystal display modes such as TN type and DSM type that do not have bistability or memory properties, the amount of reflected light is modulated by the voltage directly applied to the liquid crystal molecules, but the image retention time is difficult to determine. It's short.

On the other hand, according to the present invention, the light reflectance is determined by its threshold characteristic,
Due to the bistable memory property, it cannot take halftones and becomes 1 or 0, but
The written image will be retained semi-permanently unless a voltage higher than the threshold voltage or strong pressure is applied from the outside. After the image was formed, the voltage was left open and measurements were taken again three days later, and it was confirmed that there was almost no change in the contrast ratio, and that the film had extremely excellent memory properties.

In addition to the SiO oblique evaporation film, the liquid crystal alignment film used in the present invention is prepared by applying and baking a mixed solution of a basic chromium complex as a vertical alignment agent and polyimide as a horizontal alignment agent, and then subjecting it to a rubbing treatment. Therefore, there is no problem in using an alignment film that provides a high pretilt angle of 10° to 30°. Furthermore, even if a pyrimidine-based chiral smectic mixed liquid crystal composition or a liquid crystal mixture consisting of an ester-based chiral smectic liquid crystal composition and a pyrimidine-based chiral smectic liquid crystal composition are used as the liquid crystal to be encapsulated, exactly the same effect can be obtained. There is.

In the first, second, and third embodiments described above, the dielectric mirror according to the present invention can have an extremely low readout light transmittance, so that the light shielding layer used in the conventional optical writing type liquid crystal light valve is not required. , there is no need to provide it between the dielectric mirror and the photoconductive layer. Of course, it goes without saying that an optical writing type liquid crystal light valve having a structure in which the light-shielding layer is added so that stronger readout light can be used is very good.

Next, an application example of the optical writing type liquid crystal light valve of the present invention will be explained. FIG. 9 is a conceptual diagram of a digital color laser printer to which the optical writing type liquid crystal light valve of the present invention is applied. In the figure, 37a, 37b, and 37c are optical writing type liquid crystal light valves related to the present invention, and after images corresponding to each color of red R, green G, and full B are written by a laser scanner 38, the projection optical system 39 An image of each color is formed on the media 4° using light whose wavelength is limited using a filter corresponding to each color. The medium 31 has leuco dyes of xo-y, cyan C, and magenta M encapsulated in microcapsules 50a, 50b, and 50c that harden in response to light of different wavelengths as shown in FIG. 1O, respectively. A color image is formed on the receiver sheet 41 by applying pressure with a pressure roller 42 to the Lenher sheet 41 coated with a coloring agent.

By applying the optical writing liquid crystal light valve according to the present invention to the above system, it was possible to realize a digital color laser printer with high image quality and short output time.

Furthermore, a high-quality color projector can be realized by placing a screen at the position of the media 40 of the digital color laser printer and projecting three colors at the same time.

Next, a case where the optical writing type liquid crystal light valve of the present invention is used as an incoherent-coherent converter will be explained. In this case, CdS is used as the photoconductive layer 15 in FIG.
A vacuum-deposited material such as Se, 5eTe, etc., an organic material, or a functionally separated multilayer structure is used. The other configurations are the same as those described above.

According to the above-described incoherent-coherent converter, an image is formed on the ferroelectric liquid crystal layer I4 by incoherent writing light 20 from the outer surface of the cell, and the image formed by writing is previously Irradiation of coherent projection light 21 through a polarizer whose polarization axis is aligned with the orientation direction (or perpendicular direction thereof) of liquid crystal molecules aligned by applying an electric field opposite to the application direction, and
It can be read by projecting through an analyzer in a direction perpendicular (or parallel) to the polarization direction of the reflected light during total erasure.

The liquid crystal light pulp of the present invention will be described below as an incoherent liquid crystal light pulp.
An example of application as a coherent converter will be explained.

FIG. 11 is a conceptual diagram of a coherent optical correlation system using an optically written liquid crystal light valve according to the present invention. The reflected light from the measurement object 61 is imaged by a lens 62 onto a liquid crystal optical element 63 using an optical writing type liquid crystal light valve according to the present invention. Since the area is larger than those using optical crystals, it can be measured even when the object to be measured is large.Also, the response speed is faster than those using liquid crystals in modes such as TN and DSM, so it can be used in real time. Near high-speed processing is possible. The image produced on the optical writing type liquid crystal light HALPRO 3 is split by a polarizing beam splitter 64, and coherent light 65 whose polarization axis direction matches the director direction of the ferroelectric liquid crystal molecules at the time of complete erasure is irradiated. . The irradiated light undergoes polarization state conversion due to birefringence and is reflected only at the portion where the director is inverted due to writing. The reflected light passes through a polarizing beam splinter 64, a pass lens 66, a mantid filter 67, and a lens 68, and forms an image on a correlation coordinate plane 69, so that only the portion whose polarization state has been changed by birefringence is formed on a correlation coordinate plane 69. It performs optical information processing. In this application example, by using the incoherent-coherent converter using the liquid crystal optical element of the present invention, a coherent optical correlation system that can be used for large objects and can perform high-speed processing close to real time is developed. is realized.

Next, a case where the optical writing type liquid crystal light valve of the present invention is used as an optical bistable memory will be explained.

In this case, the photoconductive layer 15 in FIG.
: H layer. Here, the photoconductive layer 15 has a film composition to which B, P, etc. are added during discharge decomposition, or a-5i:H layer and I
A structure in which an n-type or p-type semiconductor film of other composition is layered between the TO transparent electrode, or an organic photoconductive film formed by a printing method, or a photoconductive film formed by vapor deposition of Se, 5eTe, etc. A membrane may also be used.The other configuration is as shown in FIG. 1, and since it has already been explained, the explanation here will be omitted.

The data written here is read out by the readout light (projected light ) 21 and measurement of the intensity of the reflected light through an analyzer in a direction perpendicular to (or parallel to) the polarization direction of the reflected light during the total erasure.

Memory using such liquid crystal light pulp has a recording density that depends on the spot diameter of the laser beam, so CD
- It has been confirmed that the optical bistable memory is capable of high-density recording equivalent to ROM, has fast access speed, can be erased and rewritten as many times as possible, and does not require a backup power source.

An example in which the liquid crystal light valve of the present invention is applied to an optical bistable memory will be described below.

FIG. 12 is a conceptual diagram of an optical disk memory using the liquid crystal light valve of the present invention, and FIG. 13 is an enlarged view of only the central portion of the optical disk memory. The structure of the memory sections 71a and 71b in FIG. 12 is the same as that in FIG.
A writing optical system 72 using a semiconductor laser was placed on the photoconductive film side of the memory sections 71a and 72b on the side of 1b where there is no photoconductive layer. In addition, as shown in FIG. 13, the central part of the cough optical disk memory 70 has transparent electrodes on a transparent electrode substrate.
Each has an exposed portion 81381b, and the electrode butt 83 provided on the rotating shaft 82a82b is provided in this portion.
A and 83b are brought into contact and rotated while applying an electric field to the exposure disk memory. Scanning is performed by this rotation and movement of the writing optical system 72 and the reading optical system 73 in the radial direction of the disk.

The optical disk memory of this application example is capable of high-density recording equivalent to CROM, whose recording density depends on the diameter of the laser beam, and has fast access speed, and can be erased and rewritten any number of times. It was confirmed that the Hanokhupu is an optical bistable memory that does not require a power supply.

Also, unlike the above, the optical memory is manufactured in a cart-like shape, and writing is performed using a polygon mirror or galvano mirror.
Optical bistable memory that can perform high-density recording, has fast access speed, can be erased and rewritten any number of times, and does not require a power source. It was confirmed that

[Effects of the Invention] As described above, the liquid crystal light valve of the present invention not only has a large contrast ratio, but also has a fast response speed and can perform high-speed writing using laser beams. A high-resolution, large-area, high-speed incoherent-coherent converter that can be manufactured, has a large contrast ratio, can be addressed with light such as a laser in a short time, can be accessed at high density and at high speed, and can be erased and rewritten. In addition, an optical bistable memory that does not require a power source can be realized by simply changing the photoconductive layer, and can be used as an intermediate recording medium for optical printers, image display devices, optical shutters, coherent correlation systems and other image processing devices, and optical information. This dramatically increases the performance and range of applications of systems, etc.

In addition, the dielectric mirror used in the liquid crystal light valve of the present invention has a high reflectance and has electrical characteristics that match the parameters of the liquid crystal drive circuit, making it possible to increase the resolution without blurring or unevenness of the image. did it.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the structure of the optical writing type liquid crystal light valve of the present invention, Fig. 2 is a configuration diagram of a dielectric mirror related to the present invention, and Fig. 3 is the characteristic of resistivity with respect to the composition ratio of Si and Ge. 4 is a diagram showing the optical characteristics of the dielectric mirror of the first embodiment shown in FIG. 2, and FIG. 5 is a configuration diagram showing the second embodiment of the dielectric mirror according to the present invention. Figure 6 is the fifth
FIG. 7 is a diagram showing the optical characteristics of the dielectric mirror of the second embodiment shown in the figure, FIG. 7 is a configuration diagram showing the third embodiment of the dielectric mirror according to the present invention, and FIG. A diagram showing the optical characteristics of the dielectric mirror of the example, FIG. 9 is a schematic diagram of a digital color laser printer to which the optical writing type liquid crystal light valve of the present invention is applied, and FIG. 10 is a diagram showing the digital color laser printer shown in FIG. 9. FIG. 11 is a schematic diagram showing the configuration of a writing medium used in the present invention, and FIG.
FIG. 2 is a schematic diagram of an optical disk memory using the optical writing type liquid crystal light valve of the present invention, and FIG. 13 is an enlarged view of the center of the optical disk memory shown in FIG. 8. 11a, 11b...Transparent substrates 12a, 12b...Transparent electrode layers 13a, 13b...Liquid crystal alignment film layer 14...Ferroelectric liquid crystal layer...Photoconductive layer...Dielectric mirror...・Anti-reflective coating layer...Spacer, adhesive...Writing light...Reading light...Insulating layer...-3i +-x G eX...SiO□...First layer and third layer... ...5th layer and 7th layer...9th layer and 11th layer...13th layer and 15th layer 37c...Liquid crystal light valve...Laser scanner...Projection optical system...Writing Media...Receiver sheet 50b, 50c...Microcapsule...Heath 7b...Measurement object...Lens...Light writing method Liquid crystal light valve...Polarizing beam splitter, lens... Coherent light...transmission lens...mantid filter...lens...correlation coordinate plane...magneto-optical disk memory 71b...part of memory...optical system b...transparent electrode b...・Rotation axis b...Electrode pad and above Applicant: Seiko Electronic Industries Co., Ltd. Agent Patent attorney: Keinosuke Hayashi

Claims (2)

[Claims] (1) In an optical writing type liquid crystal light valve that is equipped with a photoconductive layer, a light reflection layer, a liquid crystal alignment layer, a liquid crystal layer, and a voltage application means and can write information using light such as a laser beam or an LED, the light reflection layer is , general formula Si_1_−_x
Si and Ge compound layer denoted by Ge_x and SiO_2
An optical writing type liquid crystal light valve characterized by being composed of a dielectric mirror in which multiple layers are laminated alternately. (2) The optical writing type liquid crystal light valve according to claim 1, wherein the compound layer satisfies 0.1≦x≦0.6. (3) The elemental concentration of Ge in the compound layer constituting the light reflecting layer is 3. The optical writing type liquid crystal light valve according to claim 1, wherein the element concentration gradient is large in a layer near the photoconductive layer and small in a layer near the liquid crystal alignment layer.