JPH07128873A - Optical sensor and information recording method - Google Patents

Abstract

PURPOSE:To obtain an optical sensor having high sensitivity and excellent information recording performance. CONSTITUTION:An optical sensor 10 formed by laminating photoconductive layers 14, 15 on an electrode 12, and an information recording medium 20 obtd. by laminating an information recording layer 23 in which information can be recorded with an electric field or charges on an electrode 21 are disposed to face each other. When voltage is applied between the electrode 12 of the optical sensor 10 and the electrode 21 of the information recording medium 20, and the sensor is exposed for information, the information can be rocorded at an amplified indensity larger than the current caused by the information exposure in the information recording medium. Further, after exposure for information, conductivity can be maintained by continuously applying voltage so that the information recording in the information recording medium 20 can be continued. The photoconductive layer of the optical sensor 10 consists of a charge producing layer 14 containing a charge producing material and a charge transfer layer 15 containing a charge trasnsfer material. The charge producing layer 14 contains same or different charge transfer material as the charge transfer material used in the charge transfer layer 15. Thereby, the obtd. optical sensor 10 has high sensitivity with large difference of voltage between an unexposed area and an exposed area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording system comprising an optical sensor and an information recording medium capable of recording optical information on the information recording medium in the form of visible information or electrostatic information, and particularly to the information recording medium. The present invention relates to an optical sensor having a photoconductive layer in which the performance of recording information on the optical sensor is significantly amplified, and an information recording method.

[0002]

2. Description of the Related Art An optical sensor composed of a photoconductive layer having an electrode provided on the front surface and an information recording medium composed of a charge holding layer having an electrode provided on the rear surface are arranged on the optical axis, facing the optical sensor. Then, exposure is performed while applying voltage between both conductive layers, electrostatic charge is recorded on the charge holding layer according to the incident optical image, and the electrostatic charge is reproduced by toner development or potential reading. For example, it is described in JP-A-1-290366 and JP-A-1-289975.
Further, the charge retention layer in the above method is a thermoplastic resin layer, the electrostatic charge is recorded on the surface of the thermoplastic resin layer and then heated,
A method of visualizing the electrostatic charge recorded by forming a frost image on the surface of the thermoplastic resin layer is described in, for example, Japanese Patent Application Laid-Open No. 3-192288.

Further, the applicant of the present invention uses the polymer-dispersed liquid crystal layer as the information recording layer in the above-mentioned information recording medium, exposes it when a voltage is applied in the same manner as described above, and aligns the liquid crystal layer by an electric field formed by an optical sensor. An information recording / reproducing method of performing information recording by using a transmitted light or reflected light for reproducing information is described in Japanese Patent Application No.
We applied for 3394 and Japanese Patent Application No. 4-24722.
This information recording / reproducing method can visualize recorded information without using a polarizing plate. In such an information recording method, an information recording method having higher sensitivity and higher resolution has been demanded.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides an optical sensor and an information recording method used for forming information on an information recording medium, which are excellent in information forming ability and improved in information recording sensitivity. The challenge is to provide.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to an optical sensor having a photoconductive layer laminated on an electrode, and an information recording medium having an information recording layer laminated on the electrode for recording information by an electric field or an electric charge. When the information is exposed while the electrodes are opposed to each other and a voltage is applied between the electrodes of the photosensor and the information recording medium, the information recording is performed on the information recording medium with an intensity amplified more than the current caused by the information exposure. In addition, the optical sensor has a function of maintaining conductivity even if the voltage is continuously applied after the information exposure is completed and continuing the information recording on the information recording medium. The conductive layer is composed of two layers, a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance. In the charge generating layer, the same or different charge transport as that used in the charge transporting layer. Sex A light sensor containing.
It is an optical sensor in which the charge transporting substance in the charge generating layer is 0.1 mol% or more of the charge generating substance. In an information recording method for recording optical information on an information recording medium by information exposure, the optical sensor and the information recording medium having an information recording layer formed on an electrode are arranged opposite to each other on the optical axis with a gap provided therebetween. This is an information recording method in which a voltage can be applied between the electrode and the electrode of the information recording medium. Further, it is an information recording method in which the information recording layer of the information recording medium is composed of a resin phase and a liquid crystal phase.

That is, the photosensor in the information recording apparatus of the present invention is formed by laminating a photoconductive layer on an electrode, and the photoconductive layer is formed by laminating a charge generation layer and a charge transport layer. The photoconductive layer generally has a function of generating photocarriers (electrons, holes) in the irradiated portion when light is irradiated, and these carriers can move in the layer width. The optical sensor of (1) has a combination of a photoconductive layer and an electrode and has semiconductivity so that the electric field or the amount of electric charge applied to the information recording medium at the time of irradiating light to the optical sensor is amplified with time as the light is irradiated. Further, if the voltage is continuously applied even after the light irradiation is finished, the increased conductivity is maintained, and the electric field or the amount of charge is continuously applied to the information recording medium.

The photosensor of the present invention has a persistent electroconductivity and an amplifying action, but the photoconductor which has been known to have a persistent electroconductivity is conventionally an insulating one. There is a persistent conductivity in the process of imparting conductivity to it by light irradiation or the like. On the other hand, the optical sensor of the present invention originally has the property of semiconductivity, which is a requirement for obtaining the action of the present invention, and the insulating sensor obtains the action of the present invention. It is not possible.

That is, the photosensor of the present invention is preferably semiconductive and has a specific resistance in the dark of 10 ⁹ to 10 ¹³ Ω · cm. Especially, the specific resistance is 10 ¹⁰ to 10 ¹¹ Ω.
The amplification effect is remarkable in the range of cm. Resistivity is 1
With an optical sensor larger than 0 ¹³ Ω · cm, 10 ⁵ to 1
In the electric field strength range of 0 ⁶ V / cm, it does not show the amplifying action as the optical sensor of the present invention. Further, an optical sensor having a specific resistance of less than 10 ⁹ is not preferable because a large amount of current flows and noise is generated by the current. On the other hand, a photoconductor element used for general electrophotography has a dark resistivity of 10 ¹⁴ to 10 ¹⁶ Ω · cm,
The photosensor of the present invention cannot achieve its purpose in electrophotography, and a photosensor having a photoconductive layer having a large dark resistivity for general electrophotography can be used for the purpose of the present invention. Can not.

FIG. 1 is a sectional view for explaining an optical sensor. In the photosensor 10, a photoconductive layer 13 is provided on an electrode 12 formed on a substrate 11, and the photoconductive layer 13 is composed of a charge generation layer 14 and a charge transport layer 15. The photoconductive layer is a conductive layer in which photocarriers such as electrons and holes are generated in the irradiated portion when light is irradiated, and these carriers can move across the layer width, especially when an electric field is present. , The layer where the effect is remarkable.

The charge generating layer 14 is composed of a binder resin and a charge generating substance, and examples of the charge generating substance include pyrylium dyes, thiapyrylium dyes and azurenium dyes as described in Japanese Patent Application No. 5-4721. Cationic dyes such as dyes, cyanine dyes and azurenium dyes,
Multiple polycyclic quinone pigments such as squarylium salt dyes, phthalocyanine pigments, perylene pigments, pyrantrone pigments, indigo pigments, quinacridone pigments, pyrrole pigments, azo pigments, etc. in a single layer Can be used in combination. Alternatively, two charge generating layers may be provided and a single charge generating substance may be used for each layer. Further, an electron accepting substance may be added to the charge generating layer. An electron accepting substance may be added. As the electron accepting substance, 2,4,7-trinitrofluorenone, tetrafluoro-P-benzoquinone, tetracyanoquinodimethane, triphenylmethane, maleic anhydride, hexacyanobutadiene and the like can be used.

Examples of the binder resin include polyvinyl chloride resin, polyvinyl acetate resin, acrylic resin, polyester resin, polyvinyl formal resin, polyvinyl butyral resin, polystyrene resin, polycarbonate resin, polybutyl methacrylate resin, polyvinylidene chloride resin, ethyl cellulose. Resin, silicone resin, epoxy resin, phenol resin, melamine resin, UV curable resin, thermosetting resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-acrylic copolymer resin, vinyl chloride-ethylene copolymer Resin, acrylic-styrene copolymer resin, styrene-butadiene copolymer resin, ethylene-vinyl acetate copolymer resin and the like can be mentioned. The binder resin to be used has an average molecular weight of 1,000 to 100,0 because the coating properties are unfavorable when the molecular weight becomes large.
It is preferable to use the one of 00. Regarding the mixing ratio of these charge generating substance and binder resin, it is desirable to use the binder in an amount of 0 to 10 parts by weight, preferably 0.3 to 1 part by weight, relative to 1 part by weight of the charge generating substance. . The electron-accepting substance can be used in a ratio of 10,000 to 10 mol per mol of the charge-generating substance. The thickness of the charge generation layer after drying is 0.01 to 1 μm, preferably 0.1 to 0.3 μm.

The charge transport layer 15 is composed of a charge transport material and a binder. The charge-transporting substance is a substance having a good property of transporting charges generated by the charge-generating substance,
For example, oxadiazole-based, oxazole-based, triazole-based, thiazole-based, triphenylmethane-based, styryl-based, pyrazoline-based, hydrazone-based, aromatic amine-based,
There are carbazole-based, polyvinylcarbazole-based, stilbene-based, enamine-based, azine-based, amine-based, butadiene-based, polycyclic aromatic compound-based, and the like, and it is necessary to use a substance having a good hole transport property.

Preferred are butadiene-based and stilbene-based charge-transporting substances, specifically, JP-A-62-2.
87257, JP-A-58-182640,
JP-A-48-43942, JP-B-34-5466
JP, JP-A-58-198043, JP-A-57.
No. 101844, JP-A-59-195660, JP-A-60-69657, and JP-A-64-65.
555, JP-A-1-164952, JP-A-64-57263, JP-A-64-68761, JP-A-1-230055, JP-A-1-142.
No. 654, JP-A-1-142655, JP-A-1-155358, JP-A-1-155357, JP-A-1-161245, and JP-A-1-142.
The charge transport materials described in Japanese Patent No. 643, etc. may be mentioned.
Examples of combinations of these charge generating substances and charge transporting substances include fluorenone azo pigments (charge generating substances)
And stilbene-based and triphenylamine-based charge-transporting substances, and bisazo-based pigments (charge-generating substances) and butadiene- and hydrazone-based charge-transporting substances are preferable. In the case of transporting electrons instead of transporting holes as charges as described above, the electron transporting substance described in Japanese Patent Application No. 5-4721 can be used as the electron transporting substance.

As the binder resin, the same binder resins as those in the above-mentioned charge generation layer can be used, but preferably polyvinyl chloride resin, polyvinyl acetate resin, acrylic resin, polyester resin, polyvinyl formal resin, polyvinyl butyral resin. , Polystyrene resin, polycarbonate resin, polybutylmethacrylate resin, polyvinylidene chloride resin, ethylcellulose resin, silicone resin, epoxy resin, phenol resin,
Melamine resin, vinyl chloride-vinyl acetate copolymer resin,
Vinyl chloride-acrylic copolymer resin, vinyl chloride-ethylene copolymer resin, acrylic-styrene copolymer resin,
Styrene-butadiene copolymer resin, ethylene-vinyl acetate copolymer resin and the like polyvinyl acetal resin, styrene resin, styrene-butadiene copolymer resin can be mentioned, but when the charge-transporting substance has an action as a binder resin. Does not require the use of binder resin. The binder resin used has an average molecular weight of 1,000 to 100, because the coating properties deteriorate as the molecular weight increases.
It is preferable to use 000. The binder resin is preferably used in a proportion of 0.05 to 1 part by weight with respect to 1 part by weight of the charge transport material. The charge transport layer has a thickness after drying of 1 to 50 μm, preferably 10 to
30 μm is preferable.

In the charge transport layer, the electron-accepting substance described in the section of the charge-generating layer is mixed in a proportion of 0.0001 to 10 mol per 1 mol of the charge-transporting substance. can do. The charge transporting layer is prepared by dissolving or dispersing the charge transporting substance, the binder resin, and the electron accepting substance in the same solvent as described in the section of the charge generating layer, applying the same coating method on the charge generating layer, and drying. After the steps, it is formed to have a film thickness after drying of 1 to 50 μm.

Particularly, in the optical sensor of the present invention,
Sensitivity is increased in the optical sensor by the interaction between the charge generating substance and the charge transporting substance. In order to increase the charge generation efficiency, it is effective to reduce the proportion of the binder resin in the charge transport layer, but when the amount of the binder resin is reduced, it becomes difficult to form a smooth layer as the charge transport layer, Moreover, since the generation efficiency of photocarriers changes depending on the state of the interface between the charge generation layer and the charge transport layer, a high performance optical sensor cannot be obtained unless the interface is smooth.

The present invention has found that the photosensor can be made highly sensitive by mixing the charge transporting substance contained in the charge transporting layer into the charge generating layer. The amount of the charge transporting substance mixed in the charge generating layer is preferably 0.01 to 10 in molar ratio with respect to the charge generating substance, particularly preferably 0.1 to 1, and more preferably 0.1. 01
If it is below, the effect of addition cannot be obtained, and if it is 10 or more, the dark current is small and it is not suitable for the information recording method of the present invention, which is not preferable. The charge transporting substance mixed in the charge generating layer may be the same charge transporting substance as the charge transporting substance used in the charge transporting layer laminated on the charge generating layer, or Different charge transporting substances may be used.

The electrodes 12, it is necessary to have a transparency if opaque later information recording medium, when the information recording medium has a transparency transparent may be either opaque, 50-10 ⁴ Materials that stably provide a surface resistivity of Ω / cm ² , such as metal thin film conductive films of zinc, titanium, copper, iron, tin, tin oxide, indium oxide, zinc oxide, titanium oxide, tungsten oxide, vanadium oxide, etc. Inorganic metal oxide conductive film, organic conductive film such as quaternary ammonium salt, etc., and are used alone or as a composite material of two or more kinds. Of these, oxide semiconductors are preferable, and indium oxide-tin oxide composite oxide (ITO) is particularly preferable.

The electrode 12 is formed by vapor deposition, sputtering or CV.
It is formed by a method such as D, coating, plating, dipping, or electrolytic polymerization. The film thickness needs to be changed depending on the electrical characteristics of the material forming the electrodes and the applied voltage at the time of recording information.
The thickness is about 300 nm and is formed according to the formation pattern of the entire surface between the information recording layer and the photoconductive layer. The substrate 11 is required to have transparency if the information recording medium described later is opaque. However, if the information recording medium has transparency, it may be transparent or opaque.
It has the shape of a film, tape, disk, etc. and strongly supports the optical sensor. If the optical sensor itself has supportability, it is not necessary to provide it, but the material and thickness thereof are not particularly limited as long as it has a certain strength capable of supporting the optical sensor. For example, a flexible plastic film, a plastic sheet such as glass, polyester, or polycarbonate, or a rigid body such as a card is used. In addition, if the electrode 12 is transparent, a layer having an antireflection effect may be laminated on the other surface of the substrate on which the electrode 12 is provided, or a film having a thickness capable of exhibiting the antireflection effect may be formed. The antireflection property may be imparted by adjusting the transparent substrate or by combining the two.

Next, the information recording method of the present invention will be described. FIG. 2 is a sectional view for explaining the information recording device used in the method of the present invention. The optical sensor 10 and the information recording medium 20 are arranged so as to face each other with a spacer 16 in between and stacked. The information recording medium 20 will be described. First, as an information recording medium in the present invention, a case where the information recording layer is a polymer dispersed liquid crystal is mentioned. The polymer dispersed liquid crystal is composed of a resin phase and a liquid crystal phase, and has a structure in which resin particles are dispersed in the liquid crystal phase. The liquid crystal material uses a smectic liquid crystal, a nematic liquid crystal, a cholesteric liquid crystal or a mixture thereof. be able to. As the liquid crystal, it is preferable to use a smectic liquid crystal from the viewpoint of memory property since it retains its orientation and permanently retains information. As smectic liquid crystals, a cyanobiphenyl-based substance having a long carbon chain at the terminal group of a substance exhibiting liquid crystallinity,
Liquid crystal substances showing smectic A phase such as cyanoterphenyl type, phenyl ester type and fluorine type, liquid crystal substance showing smectic C phase used as ferroelectric liquid crystal, or liquid crystal showing smectic H, G, E, F, etc. Examples include substances.

A nematic liquid crystal may be used, and the memory property can be improved by mixing it with a smectic or cholesteric liquid crystal. For example, a Schiff base type, an azoxy type, an azo type, a benzoic acid phenyl ester type, Cyclohexyl acid phenyl ester type, biphenyl type, terphenyl type, phenyl cyclohexane type,
Known nematic liquid crystals such as phenylpyridine type, phenyloxazine type, polycyclic ethane type, phenylcyclohexene type, cyclohexylpyrimidine type, phenyl type and tolan type can be used. Also, a microcapsule obtained by mixing polyvinyl alcohol or the like with a liquid crystal material can be used. When selecting a liquid crystal material, it is preferable to use a material having a large refractive index anisotropy because it provides a high contrast.

The material for forming the resin particles is, for example, an ultraviolet curable resin that is compatible with the liquid crystal material in the monomer or oligomer state, or a solvent common to the liquid crystal material in the monomer or oligomer state. Those having compatibility with can be preferably used. Examples of such an ultraviolet curable resin include acrylic acid ester, methacrylic acid ester and the like, and in a monomer or oligomer state, for example, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, polyethylene glycol diacrylate, polypropylene glycol. Diacrylate, isocyanuric acid (ethylene oxide modified) triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetraacrylate, neopentyl glycol diacrylate, hexanediol diacrylate, etc. -Based oligomer, further nonylphenol-modified acrylate, N-vinyl-2-pyrrolidone, 2-hydroxy-3-phenoxy Monofunctional monomers or oligomers such as acrylate and the like. The solvent is not particularly limited as long as it is a solvent common to the materials used, and is represented by, for example, a hydrocarbon solvent represented by xylene or the like, a halogenated hydrocarbon solvent represented by chloroform or the like, or methyl cellosolve. Examples thereof include alcohol derivative solvents and ether solvents represented by dioxane.

As a photo-curing agent for curing the UV-curable resin, for example, 2-hydroxy-2-methyl-1-phenylpropan-1-one (Darocur 11 manufactured by Merck & Co., Inc.) is used.
73), 1-hydroxycyclohexyl phenyl ketone (Irgacure 184 manufactured by Ciba-Geigy), 1-
(4-Isopropylphenyl) -2-hydroxy-2-
Methylpropan-1-one (Merck Darocur 1
116), benzyl dimethyl ketal (Irgacure 651 manufactured by Ciba-Geigy), 2-methyl-1- [4-
(Methylthio) phenyl] -2-morpholinopropanone-1 (Ciba-Geigy Irgacure 907),
A mixture of 2,4-diethylthioxanthone (Kayacure DETX manufactured by Nippon Kayaku Co., Ltd.) and ethyl p-dimethylaminobenzoate (Kayacure EPA manufactured by Nippon Kayaku Co., Ltd.), isopropylthioxanthone (KuntaCure ITX manufactured by Ward Brekinsop), and Examples thereof include a mixture with ethyl p-dimethylaminobenzoate, but liquid 2-hydroxy-2-methyl-1-phenylpropan-1-one is compatible with a liquid crystal material, a polymer-forming monomer or an oligomer. Is particularly preferable in terms of.

The ratio of the liquid crystal material to the resin used is such that the liquid crystal content is 10% by weight to 90% by weight, preferably 40% by weight.
It is preferable to use it in an amount of 80% by weight, and if it is less than 10% by weight, the light transmittance is low even if the liquid crystal phase is oriented by information recording, and if it exceeds 90% by weight, a phenomenon such as liquid crystal seepage occurs. Occurs, and image unevenness occurs, which is not preferable. A large amount of liquid crystal is present in the information recording phase to improve the contrast ratio and reduce the operating voltage.

A method for forming the information recording layer is carried out by using a blade coater, a roll coater, a roll coater, or a mixed solution prepared by dissolving or dispersing a resin forming material, a liquid crystal, a photo-curing agent and the like in a solvent.
Alternatively, it is formed by applying by a coating method such as a spin coater and curing the resin forming material by light or heat. If necessary, a leveling agent may be added to improve the coating suitability of the solution and improve the surface property.

In forming the information recording layer, the mixed solution is heated to a temperature at which the mixed liquid of the resin-forming material and the liquid crystal maintains an isotropic phase, so that the liquid crystal and the ultraviolet-curable resin-forming material are completely compatible with each other. Therefore, it is possible to obtain an information recording layer in which a resin phase and a liquid crystal phase are uniformly dispersed. If the liquid crystal is UV-cured at a temperature below the isotropic phase, there arises a problem that the phase separation between the liquid crystal and the UV-curable resin material becomes large. That is, the liquid crystal domain grows too much, the skin layer is not completely formed on the information recording layer surface, the phenomenon of liquid crystal bleeding occurs, and the ultraviolet curable resin becomes matte, making it difficult to accurately capture information. However, it is not preferable, and the ultraviolet curable resin may not be able to hold the liquid crystal, and may not even form the information recording layer. On the other hand,
When heating is required to maintain the isotropic phase when the solvent is evaporated, there is a problem that the wettability with respect to the electrode is particularly lowered and a uniform information recording layer cannot be obtained.

A fluorine-based surfactant may be added to the information recording layer for the purpose of maintaining wettability to the electrode and forming a film on the surface of the resin. Examples of such a fluorine-based surfactant include Sumitomo 3M Ltd.
Made, Fluorard FC-430, Fluorard FC-43
1, N- (n-propyl) -N- (β-acryloxyethyl) -perfluorooctylsulfonic acid amide (EF-125M manufactured by Mitsubishi Materials Corp.), N- (n-propyl) -N- (β -Methacryloxyethyl) -perfluorooctyl sulfonic acid amide (Mitsubishi Materials Corporation)
EF-135M), perfluorooctane sulfonic acid (MF-101 manufactured by Mitsubishi Materials), perfluorocaprylic acid (EF-20 manufactured by Mitsubishi Materials)
1), N- (n-propyl) -N-perfluorooctanesulfonic acid amide ethanol (Mitsubishi Materials Corporation)
EF-121) manufactured by Mitsubishi Materials Co., Ltd.
102, same EF-103, same EF-104, same EF-1
05, the same EF-112, the same EF-121, the same EF-12
2A, EF-122B, EF-122C, EF-
122A3, EF-123A, EF-123B, EF-132, EF-301, EF-303, E
F-305, EF-306A, EF-501, E
F-700, EF-201, EF-204, EF
-351, EF-352, EF-801, EF-
802, EF-125DS, EF-1200, E
F-L102, same EF-L155, same EF-L174,
The same EF-L215 etc. are mentioned. In addition, 3- (2-perfluorohexyl) ethoxy-1,2-dihydroxypropane (MF-100 manufactured by Mitsubishi Materials Corporation), N
-N-propyl-N-2,3-dihydroxypropyl perfluorooctyl sulfonamide (MF-110 manufactured by Mitsubishi Materials Corporation), 3- (2-perfluorohexyl) ethoxy-1,2-epoxypropane (Mitsubishi Materials MF-120 manufactured by Co., Ltd., Nn-propyl-N
-2,3-epoxypropyl perfluorooctyl sulfonamide (MF-130 manufactured by Mitsubishi Materials Corporation),
Perfluorohexyl ethylene (Mitsubishi Materials Corporation)
MF-140), N- (3-trimethoxysilyl) propyl) perfluoroheptylcarboxylic acid amide (MF-150 manufactured by Mitsubishi Materials Corp.), N- (3-trimethoxysilyl) propyl) perfluoroheptyl sulfone. Examples include amide (MF-160 manufactured by Mitsubishi Materials Corp.) and the like. The fluorine-based surfactant is added in a proportion of 0.1 to 20% by weight based on the total amount of the liquid crystal and the resin forming material.

Further, the solid content concentration in the coating solution for forming the information recording layer is preferably 10 to 60% by weight, and at the time of curing, the curing conditions such as the kind and concentration of the resin, the coating layer temperature, and the ultraviolet irradiation conditions are appropriately selected. By setting
It is possible to favorably form a skin layer consisting only of a resin layer having no liquid crystal phase as the outer skin layer, which can increase the proportion of liquid crystal used in the information recording layer,
Further, it is possible to prevent the liquid crystal from seeping out. As described above, the ultraviolet curable resin has been described as the resin material, but in addition, a solvent-soluble thermosetting resin having compatibility with a liquid crystal material and a common solvent, for example, an acrylic resin, a methacrylic resin, a polyester resin, a polystyrene resin, Also, an epoxy resin, a silicone resin, etc., such as a copolymer mainly composed of these may be used. Since the film thickness of the information recording layer affects the resolution, the film thickness after drying may be 0.1 μm to 10 μm, preferably 3 μm to 8 μm, and the operating voltage should be lowered while maintaining high resolution. You can If the film thickness is too thin, the contrast of the information recording portion will be low, and if it is too thick, the operating voltage will be high, which is not preferable.

If the information recording layer itself has a supporting property and the support is omitted, a skin layer is formed on the surface of the information recording layer. Even if laminated by a method or the like, cracking does not occur and the conductivity is not lowered. In this case, it is advisable to form the information recording medium by peeling off the temporary support after providing the electrodes on the information recording layer provided on the temporary support.

An electrode 22 is laminated on a substrate 21 of the information recording medium, and an information recording layer 23 is formed on the electrode.
The electrode 22 is provided on the substrate 21 by using the same material as that of the electrode 12 in the above-described optical sensor and the same stacking method. As shown in FIG. 2, this information recording medium is arranged so as to face the above-mentioned optical sensor via the spacer 16, and both electrodes 12 and 22 are connected via a voltage source V to form a first information recording device. It The electrodes 12, 22 in this device are
Either one or both may be transparent. As the spacer, using a resin film such as polyester such as polyethylene terephthalate, polyimide, polyethylene, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyamide, polypropylene, cellulose acetate, ethyl cellulose, polycarbonate, polystyrene, polytetrafluoroethylene, etc. It may be formed, or may be formed by applying and drying each of the above resin solutions. Also, aluminum, selenium, tellurium,
It may be formed by vapor deposition of a metal material such as gold or platinum, or an inorganic or organic compound. Since the film thickness of the spacer becomes the gap distance between the optical sensor and the information recording medium and affects the voltage distribution applied to the information recording layer, it is at least 100.
The thickness is preferably not more than μm, more preferably 3 μm to 30 μm.

Further, in the information recording apparatus of the present invention, in addition to disposing the optical sensor and the information recording medium with a gap, the information recording is performed after forming an insulating dielectric layer on the photoconductive layer of the optical sensor. Layers and top electrodes may be formed. Inorganic materials such as SiO ₂ and Ti are used to form the dielectric layer.
_{O 2, CeO 2, Al 2} O 3, GeO 2, Si 3 N 4, AlN, using TiN or the like, a vapor deposition method, a sputtering method, may be formed by stacking by chemical vapor deposition (CVD) method or the like. Further, a water-soluble resin having a low compatibility with an organic solvent, for example, polyvinyl alcohol, water-based polyurethane, using an aqueous solution of water glass,
The layers may be laminated by a spin coating method, a blade coating method, a roll coating method or the like. Further, a coatable fluororesin may be used, in which case it is dissolved in a fluorine-based solvent,
It may be applied by spin coating or laminated by blade coating, roll coating, or the like. As the fluororesin which can be applied, for example, JP-A-1-131215
Organic materials such as the fluororesin disclosed in Japanese Unexamined Patent Publication, and polyparaxylylene formed into a film in a vacuum system can be preferably used.

Next, an information recording method for the information recording apparatus of the present invention will be described. FIG. 3 is a diagram illustrating an information recording method using the optical sensor of the present invention. First, a voltage is applied between the electrodes 12 and 22 by a power source. When recording on this information recording medium, the information recording medium is heated by, for example, resistance heating (not shown) embedded in the support,
By heating the liquid crystal to a temperature at which it exhibits a liquid crystal phase, the memory property can be further improved. Electrodes 12, 22
When the information light 17 is made incident while applying a voltage therebetween, the photo carriers generated in the photoconductive layer composed of the charge generation layer 14 and the charge transport layer 15 in the part where the light is made incident are generated by the electric field formed by both electrodes. The voltage is moved, the voltage is redistributed, the liquid crystal phase in the information recording layer is aligned, and recording is performed according to the pattern of the information beam 17. The voltage may be applied for a predetermined time while the information light 17 is being incident.

Since some liquid crystals have different operating voltages and ranges, when setting the applied voltage and the applied voltage time, the voltage distribution in the information recording medium is appropriately set, and the voltage distribution applied to the information recording layer is set to the liquid crystal. It is recommended to set it in the operating voltage range of. This information recording method enables planar analog recording and obtains recording at the liquid crystal level, so that high-resolution recording is achieved, and the exposure pattern is retained as a visible image due to the orientation of the liquid crystal phase.

As the information recording method, there are a camera method and a laser recording method. As a method using a camera, an information recording medium is used instead of a photographic film used in a normal camera, and it is used as a recording member, and an optical shutter can be used and an electric shutter can also be used. It is profitable. Also, the optical information is separated into R, G, and B light components by a prism and a color filter and taken out as parallel light to form one frame with three information recording media for each of R, G, and B, or 1
Color images can also be taken by recording R, G, and B images on different portions of each information recording medium to form one frame.

The laser recording method is as follows.
Argon laser (514.488n)
m), a helium-neon laser (633 nm), a semiconductor laser (780 nm, 810 nm, etc.) can be used,
Laser exposure corresponding to an image signal, a character signal, a code signal, and a line drawing signal is performed by scanning. An analog recording such as an image is performed by modulating the light intensity of the laser, and a digital recording such as a character, a code or a line drawing is performed by ON / OFF control of the laser light. Further, in the case of halftone dot formation in an image, a laser beam is subjected to ON / OFF control of a dot generator.

The exposure information recorded on the information recording medium is obtained by separating the information recording medium and reproducing the information by transmitted light.
In the information recording part, light is transmitted because the liquid crystal is oriented in the direction of the electric field, whereas light is scattered in the part where information is not recorded, and contrast with the information recording part is obtained.
The information recorded by these information recording devices may be read by reflected light. The information recorded by the orientation of the liquid crystal is visible information that can be visually read, but it can also be read by enlarging it with a projector and highly accurate by laser scanning or transmitted light or reflected light using a CCD. The information can be read by and the scattered light can be prevented by using a Schlieren optical system as needed.

The information recording medium in the information recording apparatus of the present invention records electrostatic information in a state in which the electrostatic information is visualized by the orientation of the liquid crystal. However, by selecting the combination of the liquid crystal and the resin, the information is once oriented and visualized. Information is not erased, and a memory property is added. Further, by heating to a high temperature near the isotropic phase transition, the memory can be erased, so that it can be used for recording information again.

The optical sensor of the present invention is suitable for recording information on an information recording medium having a polymer dispersed liquid crystal as an information recording layer as described above, but other information recording medium, for example, Japanese Patent Laid-Open No. 4-70842. Japanese Patent Laid-Open No. 4-46347,
An electrostatic information recording medium described in JP-A-3-7942, JP-A-4-73769, etc., which uses an insulating resin layer having an excellent charge retention property such as a fluororesin as an information recording layer, Stores information in the form of electrostatic charge and is toner developed,
An information recording medium capable of reproducing electrostatic information by reading a potential, and Japanese Patent Laid-Open Nos. 3-170985, 3-170984, and 3-192288.
An information recording medium having a thermoplastic resin layer as an information recording layer, which is described in Japanese Patent Application Laid-Open Publication No. 2004-242242, where information is accumulated on the surface in the form of an electrostatic charge in the same manner as above, and then the information is frosted by being heated. It can also be used for information recording on an information recording medium that can be stored as an image and reproduced as visible information.

Further, the optical sensor of the present invention cannot be used in the present invention because it does not have the semiconductivity which is a feature of the present invention in the as-prepared state. For use in the present invention, by leaving it in a bright place for a predetermined time or longer, it becomes a sensor that exhibits a predetermined semiconductivity even in a dark place. Further, it may be used after uniformly exposing the entire surface with a sufficient amount of light before use as an optical sensor.

FIG. 4 shows a method for measuring the characteristics of the optical sensor of the present invention. A gold electrode 17 having a size of 0.16 cm ² is formed on the charge transport layer 15 of the photosensor, and a direct current is applied between the gold electrode and the transparent electrode 12 so that the transparent electrode side is positive. The light source 31 and the optical shutter 32 are arranged so that the optical sensor can be irradiated with light for a certain period of time. After 500 ms from the start of voltage application, 20 lux of green light is irradiated for about 33 ms. A resistor is connected between the optical sensor and the power supply, and the current flowing through the optical sensor can be measured by measuring the voltage across the resistor.

In FIG. 5, the horizontal axis shows the time and the vertical axis shows the measurement results showing the change with time in the current value after the start of light irradiation. The light irradiation start time was set to t = 0. At this time, the current value at time t = 0 was defined as the dark current value, and the difference between the measured current value and the dark current value was defined as the photocurrent. As shown in the figure, the photocurrent increases during the light irradiation, and the photocurrent decays after the light irradiation ends, but the photocurrent continues to flow for a sufficiently long time. Therefore, each photosensor can be compared with each photocurrent value at the photocurrent value 33 msec after the start of irradiation with 20 lux of green light.

In such an amplification type optical sensor having a large dark current value, the larger the dark current value, the larger the photocurrent value tends to be. When this optical sensor is used in an information recording system, if the dark current value is different, the optical sensor with a large photocurrent does not always have a higher information forming ability, and the ratio of the dark current value to the photocurrent value is not always higher. Need to compare. In addition, the information forming ability when a polymer dispersion type liquid crystal medium is used as the information recording medium shows that when the liquid crystal recording medium is a parallel circuit of a resistor and a capacitor, the liquid crystal recording medium is exposed in the exposed portion and the unexposed portion. FIG. 6 shows the results obtained by measuring the applied voltage from the measurement data of the characteristics of the optical sensor. Since the exposed part has higher conductivity than the unexposed part, an extra voltage is applied to the liquid crystal recording medium, and the liquid crystal recording medium in the exposed part is transmitted to record information. FIG. 7 shows the time change of the potential difference between the exposed portion and the unexposed portion. At this time, the larger the potential difference between the exposed portion and the unexposed portion is, the better image information can be recorded. Therefore, the greater the potential difference, the more sensitive the optical sensor can be. Further, the liquid crystal recording medium has a threshold value, and it is necessary to compare the potential difference when the potential of the unexposed portion reaches the threshold value of the liquid crystal recording medium.

As described above, when the photosensors of the present invention were compared, it was found that the performance was improved by mixing the charge transporting substance in the charge generating layer, as compared with the case where the charge generating material was not mixed. . As described above, it was possible to obtain an optical sensor which can be easily and smoothly formed into a film in manufacturing and can record information with high efficiency.

[0044]

The optical sensor having the photoconductive layer laminated on the electrode and the information recording medium having the information recording layer laminated on the electrode capable of recording information by electric field or electric charge are arranged to face each other. When information exposure is performed with a voltage applied between the electrode of the information recording medium and the electrode of the information recording medium, it is possible to record information on the information recording medium with an intensity amplified more than the current caused by the information exposure. In a photosensor having a function of continuing conductivity by continuing to apply a voltage after completion of the step and continuously continuing to record information on an information recording medium, including a charge generating layer containing a charge generating substance and a charge transporting substance. In the charge generation layer of the photoconductive layer composed of two charge transport layers, the same or different charge transport material as that used in the charge transport layer is mixed, so that the potential difference between the unexposed portion and the exposed portion is It is possible to obtain light sensor Kinadaka sensitivity.

[0045]

【Example】

Example 1 A film having a thickness of 1 was formed on a 1.1 mm-thick glass substrate that had been thoroughly washed.
An ITO film of 00 nm was formed by sputtering to obtain an electrode layer. On the electrode, 3 parts by weight of a bisazo pigment having the following structure, 1/100 in molar ratio with respect to the bisazo pigment
A charge-transporting substance as described below, vinyl chloride
0.75 parts by weight of vinyl acetate copolymer, 0.25 parts by weight of polyvinyl acetate, 98 parts by weight of 1.4-dioxane, 98 parts by weight of cyclohexanone were mixed and dispersed for 6 hours with a paint shaker to prepare a coating solution, which was then applied to a spinner. 1400r
After coating at pm for 0.4 seconds, the coating was dried at 100 ° C. for 1 hour to form a charge generation layer having a thickness of 300 nm.

[0046]

[Chemical 1]

On this charge generation layer, 1 part by weight of a compound having the following structure as a charge transporting substance and 4 parts of a polystyrene resin were used.
80 parts by weight of a coating solution prepared by mixing 22 parts by weight of 1,1,2-trichloromethane and 14 parts by weight of dichloromethane at 400 rpm for 0.4 seconds with a spinner.
After drying for 2 hours, a charge transport layer was laminated to obtain photosensors of Sample Nos. 1 to 3 having a photoconductive layer having a film thickness of 20 μm and composed of a charge generation layer and a charge transport layer. The obtained optical sensor was used after being aged for 3 days in a dark place with a relative humidity of 60% or less after the production. The molar ratios of the charge generating substance and the charge transporting substance in the charge generating layer of each sample number were as follows. Sample No. 1 10000: 1 Sample No. 2 100: 1 Sample No. 3 10: 1 Sample No. 4 1: 1

[0048]

[Chemical 2]

Comparative Example 1 Sample 6 in which only the charge generating substance was used in the photosensor and the charge generating layer of Sample 5 in which the ratio of the charge generating substance to the charge transporting substance in the charge generating layer was 1:10. The optical sensor of was prepared in the same manner as in Example 1 except that the compounding ratio was changed.

Example 2 With respect to the photosensors produced in Example 1 and Comparative Example 1, the photocurrent and dark current values were measured by the method shown in FIG.
FIG. 8 shows the relationship between the dark current and the voltage when the measurement voltage is changed from 100 to 600V. The dark current value tends to decrease as the content of the charge transporting substance in the charge generating layer increases. 9 shows the relationship between the photocurrent and the voltage, and FIG. 10 shows the relationship between the photocurrent and the dark current. From FIG. 10, the ratio of photocurrent to dark current tends to increase as the ratio of the charge transport material in the charge generation layer increases. This indicates that the optical sensor has high recording performance. Table 1 shows the measured values at the measurement voltage of 300V.

[0051]

[Table 1]

Example 3 The information recording performance of the optical sensor when the liquid crystal recording medium was used as the information recording medium was determined. The liquid crystal recording medium was a parallel circuit of a resistor and a capacitor, the film thickness was 6 μm, the capacitance per 1 cm ^{2 was} 1000 pF, and the electric resistance was 160 MΩ. Since the current (dark current) in the unexposed portion of the optical sensor is different, if the applied voltage for information recording is the same, the voltage applied to the liquid crystal recording medium in the unexposed portion is different. Therefore, for each optical sensor, the voltage applied to the liquid crystal recording medium in the unexposed area is 6
The applied voltage was corrected so as to reach the threshold value of the liquid crystal recording medium after 0 msec. FIG. 11 shows the result of time change of the potential difference between the exposed portion and the unexposed portion for each optical sensor.
Further, the maximum value of the voltage difference between the exposed portion and the unexposed portion is shown in Table 1 as a potential difference. When the molar ratio is 1:10 or more, the dark current is too low to record an image.

[0053]

As a charge generation layer formed as a photoconductive layer of an optical sensor, a charge generation layer in which a charge transport substance is mixed with a charge transport substance is formed, and then a layer of the charge transport substance is formed. It is possible to obtain a highly sensitive optical sensor in which the potential difference between the unexposed portion and the exposed portion is large.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating an optical sensor of the present invention.

FIG. 2 is a sectional view illustrating an information recording device used in the information recording method of the present invention.

FIG. 3 is a diagram illustrating an information recording method using the optical sensor of the present invention.

FIG. 4 is a diagram illustrating a method for measuring the characteristics of the optical sensor of the present invention.

FIG. 5 is a diagram illustrating electrical characteristics of an optical sensor.

FIG. 6 is a diagram illustrating a voltage applied to an information recording medium made of polymer dispersed liquid crystal.

FIG. 7 is a diagram illustrating a time change of a potential difference between an exposed portion and an unexposed portion.

FIG. 8 is a diagram illustrating electrical characteristics of an optical sensor.

FIG. 9 is a diagram illustrating electrical characteristics of an optical sensor.

FIG. 10 is a diagram illustrating electrical characteristics of an optical sensor.

FIG. 11 is a diagram illustrating electrical characteristics of an optical sensor.

[Explanation of Codes] 10 ... Photosensor, 11 ... Substrate, 12 ... Electrode, 13 ... Photoconductive layer, 14 ... Load generation layer, 15 ... Charge transport layer, 16 ... Spacer, 17 ... Information light, 20 ... Information recording medium , 21 ... Substrate, 22 ... Electrode, 23 ... Information recording layer 31 ... Light source, 32 ...
Optical shutter

Claims (4)

[Claims] 1. An optical sensor having a photoconductive layer laminated on an electrode and an information recording medium having an information recording layer capable of recording information by an electric field or electric charges laminated on the electrode are arranged to face each other. When information exposure is performed with a voltage applied between the electrodes of the optical sensor and the information recording medium, information can be recorded on the information recording medium with an intensity amplified above the current resulting from the information exposure, and A photosensor having a function of continuing conductivity by continuing to apply a voltage even after finishing information exposure, and continuously continuing to record information on an information recording medium, in which a photoconductive layer of the photosensor contains a charge-generating substance. It is composed of two layers, a charge generating layer containing a charge transporting material and a charge transporting layer containing a charge transporting material, and the charge generating layer contains a charge transporting material which is the same as or different from that used in the charge transporting layer. Tosu Light sensor. 2. An optical sensor, wherein the charge transporting substance in the charge generating layer is 0.1 mol% or more of the charge generating substance. 3. An information recording method for recording optical information on an information recording medium by information exposure, wherein a gap is provided between the optical sensor according to claim 1 and the information recording medium having an information recording layer formed on an electrode. An information recording method, characterized in that the electrodes are arranged so as to face each other on an optical axis, and a voltage is applied between an electrode of an optical sensor and an electrode of an information recording medium so that a voltage can be applied. 4. The information recording method according to claim 3, wherein the information recording layer of the information recording medium comprises a resin phase and a liquid crystal phase.