JPH06332001A - Information recording medium - Google Patents

Abstract

(57) [Summary] [Structure] The first information recording medium of the present invention is shown in FIG.
The information recording layer 11 made of a polymer liquid crystal exhibiting a smectic phase is laminated on the electrode layer 13 as shown in FIG. The second information recording medium is, as shown in FIG. 1B, an electrode layer 13 ', a photoconductive layer 14, an information recording layer 11,
In the information recording medium in which the electrode layers 13 are sequentially provided, at least one electrode is transparent, and the information recording layer is the same as that of the first information recording medium. [Effect] The information recording medium of the present invention does not require heating for recording information by forming the information recording layer with a polymer liquid crystal exhibiting a smectic phase, and further, once recorded information has a memory property. In addition, since the second information recording medium has the photoconductive layer, the second information recording medium does not need to be combined with an optical sensor and can record information by itself.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording medium capable of recording information by exposure with voltage application or voltage application using an optical sensor and recording electrostatic information as visible information.

[0002]

2. Description of the Related Art In the conventional electrophotographic technology, there is known an information recording medium in which a liquid crystal cell in which a nematic liquid crystal is sealed on a photoconductive layer between a pair of electrodes and an insulating layer for liquid crystal alignment are sequentially laminated. Is known in which information is exposed with a voltage applied between electrodes to lower the resistance of the photoconductive layer in the information exposed portion to align the liquid crystal and obtain a visible image using a deflector.

This information recording medium needs to be made into cells in order to enclose the liquid crystal, and in order to perform twist nematic orientation in the initial stage, an insulating film whose both surfaces are oriented by rubbing treatment is provided, and further, the cells are further provided. It is necessary to mix spacers to keep the gap constant, and it is not possible to obtain a high-resolution image. There is also an optical problem because a rigid and transparent support is required to form the gaps or cells.
Further, there is also a problem that such an alignment-processed material in the initial state cannot be detected unless a polarizing plate is used for reading.

The present inventors first prepared an information recording layer by laminating an information recording layer composed of a heat-melting type (thermotropic type) liquid crystal polymer layer on an electrode layer to form an information recording medium, which was opposed to an optical sensor. While heating to the liquid crystal phase region, exposure is performed when a voltage is applied, information is recorded by orienting the liquid crystal phase according to the information exposure, and by cooling the information recording layer,
It was found that the recorded information can be stored, and the application was filed earlier (Japanese Patent Application No. 1-67249). However, this type of information recording medium requires heating for recording.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to an information recording medium having a polymer liquid crystal of this kind as an information recording layer, which does not require heating for recording and can retain the recorded information permanently. The present invention relates to a medium, and an object thereof is to provide an information recording medium capable of recording information with high sensitivity and good contrast.

[0006]

A first information recording medium of the present invention is characterized in that an information recording layer made of a polymer liquid crystal exhibiting a smectic phase is laminated on an electrode layer.

The second information recording medium of the present invention is an information recording medium in which an electrode layer, a photoconductive layer, an information recording layer, and an electrode layer are sequentially provided, and at least one of the electrodes is transparent, and the information recording is performed. It is characterized in that the layer is composed of a polymer liquid crystal exhibiting a smectic phase.

FIG. 1A is a diagram for schematically explaining a cross section of a first information recording medium of the present invention, in which 3 is an information recording medium, 11 is an information recording layer, and 13 is an electrode layer. , 15 are substrates.

The information recording layer 11 is composed of a polymer liquid crystal exhibiting a smectic phase. As the polymer liquid crystal exhibiting a smectic phase, a polymer liquid crystal having a glass transition temperature of room temperature or lower may be used alone, or a polymer liquid crystal having a glass transition temperature of room temperature or higher may be mixed with a low molecular liquid crystal to obtain a glass liquid. Examples thereof include those having a low transition temperature and exhibiting a smectic liquid crystal phase, which are dissolved in a solvent to form an information recording layer by coating and forming on the electrode layer.

Examples of the polymer liquid crystal having a glass transition temperature of room temperature or lower include, for example,

[0011]

[Chemical 1]

(In the formula, n is about 40, glass transition temperature is -3.9 ° C., smectic phase-isotropic phase transition temperature 7
9.1 ° C., trade name LCP93, manufactured by Merck Ltd.) and the like. Such a polymer liquid crystal exhibiting a smectic phase at room temperature is dissolved in a solvent and applied on the electrode layer to form an information recording layer.

Further, in the case of a polymer liquid crystal having a glass transition temperature of room temperature or higher, a low molecular weight liquid crystal substance is mixed at an appropriate ratio to lower the glass transition temperature of the polymer liquid crystal so that the polymer liquid crystal is used at room temperature or the like. It can exhibit a smectic liquid crystal phase under the conditions and can be used. As the polymer liquid crystal having a glass transition temperature of room temperature or higher, for example,

[0014]

[Chemical 2]

(In the formula, n = 19 and the number average molecular weight is 8
690, weight average molecular weight 19090, weight average molecular weight /
Number average molecular weight = 2.19, glass transition temperature 39.0 ° C.,
Smectic phase-isotropic phase transition temperature 127.5 ° C., product name LCP94, manufactured by Merck),

[0016]

[Chemical 3]

In the formula, n = 40 and the glass transition temperature is 3
7.2 ° C., smectic phase-isotropic phase transition temperature 148.6
℃, trade name LCP83, manufactured by Merck),

[0018]

[Chemical 4]

In the formula, n = 12 and the number average molecular weight is 37.
90, weight average molecular weight 6000, weight average molecular weight / number average molecular weight = 1.58, glass transition temperature 46.7 ° C., smectic phase-isotropic phase transition temperature 82.9 ° C., trade name LCP
95, manufactured by Merck & Co., Inc., and the like.

The low-molecular liquid crystals mixed with these polymer liquid crystals include smectic liquid crystals, nematic liquid crystals,
A cholesteric liquid crystal or a mixture thereof can be used, but it is preferable to use a smectic liquid crystal from the viewpoint of so-called memory property that retains the orientation of the liquid crystal and permanently retains information.

As the smectic liquid crystal, a liquid crystal substance exhibiting a smectic A phase such as a cyanobiphenyl type, a cyanoterphenyl type, a phenyl ester type having a long carbon chain at the terminal group of a substance exhibiting liquid crystallinity, or a fluorine type, a ferroelectric substance A liquid crystal substance exhibiting a smectic C phase used as a liquid crystal,
Alternatively, a liquid crystal substance exhibiting smectic H, G, E, F or the like can be given. A nematic liquid crystal may be used, and the memory property can be improved by mixing with a smectic or cholesteric liquid crystal, and examples thereof include a Schiff base type, an azoxy type, an azo type, a benzoic acid phenyl ester type, and a phenyl cyclohexylate. Known nematic liquid crystals such as ester type, biphenyl type, terphenyl type, phenyl cyclohexane type, phenyl pyridine type, phenyl oxazine type, polycyclic ethane type, phenyl cyclohexene type, cyclohexyl pyrimidine type, phenyl type and tolan type can be used.

Although the polymer liquid crystal itself has a film-forming property, a solvent-soluble resin may be blended as a binder. By making the refractive index of the polymer liquid crystal to be almost the same as that of the polymer liquid crystal, it is opaque due to light scattering when no electric field is applied, and the liquid crystal phase is oriented when an electric field is applied, making the information recording part transparent. In addition, the deflector plate is not necessary for reproducing information, and the optical system for reading can be simplified. Examples of such a binder include acrylic resin, methacrylic resin, polyester resin, polystyrene resin, and copolymers containing these as a main component, epoxy resin, silicone resin, etc. 10 to 900 parts by weight, preferably 50 to 2 parts by weight
It is advisable to add it in a proportion of 00 parts by weight.

A polymer liquid crystal having a glass transition temperature below room temperature,
Alternatively, a polymer liquid crystal having a glass transition temperature of room temperature or higher and a low molecular weight liquid crystal, and a solvent for a mixture of these liquid crystal and a resin includes xylene, cyclohexanone, a halogenated hydrocarbon solvent represented by chloroform, methyl, or the like. Alcohol derivative solvent represented by cellosolve,
Examples thereof include ether solvents such as dioxane. In addition, specifically, methyl alcohol, denatured ethanol, isopropanol, n-propanol, sec
-Butanol, isobutanol, n-butanol, methylisobutylcarbinol, diisobutylcarbinol, hexylene glycol, acetic acid-sec-butanol, isobutyl acetate (98%), n-butyl acetate, methylaluminum acetate, aluminum acetate (95% Isomer mixture), ethyl lactate, methyl oxitol, ethyl oxitol,
Isopropyl oxitol, methyl oxitol acetate, ethyl oxitol acetate, butyl oxitol, methyl dioxitol, ethyl dioxitol,
Butyldioxitol, butyldioxitol acetate, methyl isobutyl ketone, ethyl amyl ketone, P
ent-O-xone (ME-6K), methylcyclohexanone, diisobutyl ketone, diacetone alcohol, isophorone, 1,4-dioxane, perchloroethylene, dichloropropane, 2-nitropropane, toluene, SBP100 / 140, rubber solvent, Xylene, SB
P140 / 165, SBP6, SBP11, Shell
solA, white spirit (LAWS), Shel
lsolE, ShellsolTD, White Spirit (115 ° F flammable), ShellsolT, Shell
lsolAB, Distillate, Solvent
300, ShellsolN, ShellsolRA,
ShellsolK, ShellsolR, Solve
nt350 and the like.

As a coating method, spinner coating, blade coating, dip coating and the like can be used. The average thickness of the information recording layer after drying is from 1 μm to
It is set to 30 μm. If the film thickness is too thick, the operating voltage will be high, but generally it is better to make the film thickness thinner to increase the sensitivity and thicker to increase the contrast.
In order to provide excellent sensitivity and contrast ratio, the film thickness is preferably 3 μm to 20 μm, more preferably 5 μm to 10 μm. As a result, the operating voltage can be lowered while maintaining high contrast.

The electrode layer 13 is required to be transparent when reading the information recorded on the information recording layer with transmitted light, and the metal thin film conductive film has a specific resistance value of 10 ⁶ Ω · cm or less. Film, conductive film of inorganic metal oxide such as indium tin oxide,
It is an organic conductive film such as a quaternary ammonium salt. The electrode layer is formed by a method such as vapor deposition, sputtering, CVD, coating, plating, dipping and 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. For example, an ITO film has a thickness of about 100 to 3000 Å, and the entire surface between the information recording layer and Alternatively, it is formed according to the formation pattern of the information recording layer.

When the information recorded on the information recording layer is read by reflected light, the electrode layer may be made light reflective or a light reflective layer may be laminated on the transparent electrode layer, for example, aluminum or the like. The metal electrode may be formed by a vapor deposition method or the like. As the light reflecting layer, for example, a dielectric mirror layer can be cited, and it is advisable to provide it on one side or both sides of the electrode layer at least.

The substrate 15 may be either transparent or opaque depending on whether information is read by transmitted light or reflected light. The information recording medium may have a shape such as a card, a film, a tape, a disc, etc., but the support strongly supports the information recording medium, and when the information recording layer has supportability, No need to provide. The material and thickness of the support are not particularly limited, and include, for example, a flexible plastic film or glass,
Rigid bodies such as plastic sheets and cards are used. Specifically, when the information recording medium has a flexible film, tape, disc, or card shape, a flexible plastic film is used, and when strength is required, a rigid sheet or glass. Inorganic materials and the like are used.

When information is reproduced by transmitted light, a layer having an antireflection effect may be laminated if necessary, or the transparent substrate may be adjusted to a film thickness capable of exhibiting the antireflection effect. Antireflection property may be imparted by combining the both. In addition, a primer layer may be provided between the respective layers such as the above-mentioned electrode layer, antireflection layer, and substrate in order to improve the adhesiveness.

Next, an information recording method on the first information recording medium of the present invention will be described. The information is recorded using a method such as an optical sensor, heat, laser, corona charging, etc., but preferably, an optical sensor is used to record the information. Such an optical sensor is one in which an electrode layer and a photoconductive layer are laminated on a transparent substrate, and the photoconductive layer is a single layer having a charge generating function and a charge transporting function corresponding to information light at the same time. System, and a laminated system in which a charge generation layer and a charge transport layer are sequentially laminated on an electrode layer, and are formed by the same material and forming method as the photoconductive layer in the second information recording medium described later. It The photoconductive layer generally has a function of generating photocarriers (electrons and holes) in the irradiated portion when irradiated with light, and these carriers can move in the layer width. When present, the effect is significant. An example of such an optical sensor is Japanese Patent Application No. 4-2879.
The optical sensor described in No. 83 is mentioned. In the optical sensor described in this publication, the electric field or the amount of electric charge applied to the information recording medium at the time of light irradiation is amplified as the light is irradiated, and the conductivity of the sensor is maintained when the voltage is continuously applied even after the light irradiation is completed. It has a function of continuing and continuously applying an electric field or an electric charge to the information recording medium.

An information recording device incorporating an optical sensor is shown in FIG. In the figure, 1 is an optical sensor, 3 is an information recording medium, and 1
3, 13 'are electrode layers, 14 is a photoconductive layer, 11 is an information recording layer, 15 is a substrate, 19 is a spacer, 21 is a light source, 22
Is a shutter having a drive mechanism, 23 is a pulse generator (power supply), and 24 is a dark box.

When information light is made incident from the light source 21 while voltage is being applied by the pulse generator 23 between the electrodes 13 and 13 ', photo carriers generated in the photoconductive layer 14 at the portion where the light is made incident are generated on both electrodes. By the electric field formed by, the electric field moves to the interface on the information recording layer 11 side, the voltage is redistributed, the liquid crystal phase in the information recording layer 11 is aligned, and recording is performed according to the pattern of information light. In the figure, the photoconductor side is the positive electrode and the information recording medium side is the negative electrode, but it goes without saying that the polarity is set according to the discharge characteristics of the optical sensor.

When setting the applied voltage, since some liquid crystal materials operate at a low voltage, the voltage distributions of the optical sensor, the air gap, and the information recording medium are appropriately set and applied to the information recording layer. The voltage should be set in its operating voltage range. Information recording by this optical sensor is possible as planar analog recording, and since the liquid crystal phase can be aligned at the electrostatic charge level,
The same high resolution as in the silver salt photography method can be obtained, and the exposure pattern is retained as a visible image due to the alignment of the liquid crystal.

As a method of inputting information to the first information recording medium of the present invention, there are a method using a camera and a recording method using a laser. 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. Further, 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 sets of R, G, B decomposed information recording media, or on one plane. Color images can also be taken by arranging the R, G, and B images side by side to form one frame for one set.

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. In the case of halftone dot formation in an image, laser light is subjected to dot generator ON-OFF control.

As shown in FIG. 3, when the electrostatic information recorded on the information recording medium is reproduced by transmitted light, the liquid crystal is oriented in the electric field direction in the information recording portion, so that the light A is transmitted. On the other hand, the light B is scattered at the portion where no information is recorded, and the contrast with the information recording portion can be obtained.
The information recorded by the orientation of the liquid crystal is visible information that can be visually read, but it can also be magnified and read by a projector, laser scanning, or CC.
Information can be read with high accuracy by reading using D, and scattered light can be prevented by using a Schlieren optical system as needed. Furthermore, as described above, it is possible to read by reflected light by making the electrode layer itself light reflective or by laminating a light reflective layer on the electrode layer.

Next, the second information recording medium of the present invention will be described. The second information recording medium is one in which a photoconductive layer is incorporated into the first information recording medium, and does not require an optical sensor or the like for recording information and can record information by itself. FIG. 1B is a diagram for schematically explaining the cross section, in which 3 is an information recording medium, 11 is an information recording layer, 13 and 13 'are electrode layers, 14 is a photoconductive layer,
Reference numeral 5 is a substrate.

Photoconductive layer 14 laminated on electrode 13 '
There are a single layer type and a laminated type in which a charge generation layer and a charge transport layer are laminated. The photoconductive layer generally has a function of generating photocarriers (electrons and holes) in the irradiated portion when irradiated with light, and these carriers can move in the layer width. When present, the effect of the layer is remarkable, but in particular, the electric field applied to the information recording layer during light irradiation to the photoconductive layer is amplified with light irradiation, and the voltage is applied even after the light irradiation is completed. It is preferable to have a function of continuing the application of the magnetic field to keep its conductivity and continuously applying the electric field to the information recording medium.

First, the single-layer photoconductive layer is formed of an inorganic photoconductive material or an organic photoconductive material. As the inorganic photoconductive substance, Se, Se-Te, ZnO, Ti
O _2, Si, CdS, and the like, a vapor deposition method, a sputtering method, the electrode layer by a CVD method or the like, 5 to 30 [mu] m, alone or mixed system, is laminated preferably in a thickness of 20 to 30 [mu] m. Further, the above-mentioned inorganic photoconductor as fine particles may be dispersed in an organic insulating resin such as a silicone resin, a polyester resin, a polycarbonate resin, a styrene-butadiene resin, a styrene resin, or a polyvinyl acetal resin to form a photoconductive layer, In this case, 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, of the photoconductive fine particles are dispersed in 1 part by weight of the resin.

The organic photoconductive substance includes a polymer photoconductive substance and a dispersion of a low molecular weight photoconductive substance in an insulating binder. As the polymer photoconductive substance, for example, polyvinylcarbazole (PVK), poly-N-ethylenically unsaturated group substitution containing allyl group or acryloxyalkyl group ethylenically unsaturated group instead of vinyl group in PVK There are carbazoles, poly-N-ethylenically unsaturated group-substituted phenothiazines such as poly-N-acrylphenothiazine and poly-N- (β-acryloxy) phenothiazine, and polyvinylpyrene. Above all, poly
N-ethylenically unsaturated group-substituted carbazoles, particularly polyvinylcarbazole, are preferably used.

Examples of the low molecular weight photoconductive substance include oxadiazoles substituted with an alkylaminophenyl group and the like, triphenylmethane derivatives, hydrazone derivatives, butadiene derivatives, stilbene derivatives and the like. 1 part by weight is 0.1 to 5 parts by weight, preferably 0.1 to 1 part by weight of an electrically insulating resin such as a silicone resin, a polyester resin, a polycarbonate resin, a styrene-butadiene copolymer resin, a styrene resin or a polyvinyl acetal resin. It may be dispersed in parts by weight to form a film-forming organic photoconductive substance. The film thickness of these organic photoconductive substances after drying is 5 to 30 μm, preferably 10 to 30 μm.
m on the electrode.

If desired, the organic photoconductive layer may contain a persistent conductivity imparting agent described in Japanese Patent Application No. 4-287983. The above-mentioned organic photoconductive layer itself has a persistent conductivity, and this persistent conductivity imparting agent is added for the purpose of enhancing the persistent conductivity in the above-mentioned organic photoconductive layer. The persistent conductivity imparting agent is 0.001 to 1 part by weight with respect to 1 part by weight of the organic photoconductive substance,
Preferably 0.001 to 0.1 part by weight is added. If the added amount of the persistent conductivity imparting agent exceeds 1 part by weight,
This is not preferable because the amplification function of the photoconductive layer is significantly reduced. In addition, some persistent conductivity imparting substances do not have a spectral sensitivity in visible light, and when utilizing optical information in the visible light region, an electron-accepting substance is added to increase sensitivity in the visible light region. A dye or the like can be further added. Examples of the electron accepting substance include nitro-substituted benzene, diano-substituted benzene, halogen-substituted benzene, quinones and trinitrofluorenone. Examples of the sensitizing dye include triphenylmethane dye, pyrylium salt dye and xanthene dye. Electron-accepting substances, sensitizing dyes, etc.
It is added in an amount of 0.001 to 1 part by weight, preferably 0.01 to 1 part by weight, relative to 1 part by weight of the organic photoconductive substance. At the same time, when the optical information is in the infrared region, it is advisable to add a pigment such as phthalocyanine or the like, a pyrrole-based dye, a cyanine-based dye or the like in the same amount, and vice versa. In this case, the purpose is achieved by adding the same amount of each wavelength absorbing substance.

Next, the laminated photoconductive layer is formed by sequentially laminating the charge generation layer and the charge transport layer on the electrode, and includes an inorganic material photoconductive layer and an organic material photoconductive layer. The charge generation layer in the inorganic system is formed by depositing Se—Te, Si doped with sulfur, oxygen, or the like on the electrode by a vapor deposition method, a sputtering method, a CVD method, or the like to have a thickness of 0.05 μm to 1 μm. Then, as a charge transport layer, Se, As is formed on the charge generation layer.
₂ Se ₃ , Si, Si doped with methane or the like may be similarly laminated to have a film thickness of 10 μm to 50 μm.

Next, the charge generating layer in the organic system comprises a charge generating substance and a binder.
Fluorenone azo pigments, monoazo pigments, bisazo pigments, pyrrole pigments, azulenium salt pigments, phthalocyanine pigments, polycyclic aromatic pigments, pyrylium salt pigments, triazo pigments, squarylium salt pigments, perylene pigments , Antoanthrone pigments, cyanine pigments, polycyclic quinone pigments, imidazole pigments and the like, and specific examples thereof include the charge generating substances described in Japanese Patent Application No. 4-287983.

Examples of the binder include silicone resin, styrene-butadiene copolymer resin, epoxy resin, acrylic resin, saturated or unsaturated polyester resin, PMMA resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate mixed resin and the like. For example, the charge generation material is formed by dispersing it in a binder. The charge generating agent is preferably a fluorenone azo pigment or a bisazo pigment, and the binder is preferably a polyester resin or a vinyl chloride-vinyl acetate mixed resin. It is desirable that the charge generating agent and the binder are used in a mixing ratio of 0.1 to 10 parts by weight, preferably 0.1 to 1 part by weight, relative to 1 part by weight of the charge generating agent. The charge generation layer has a thickness after drying of 0.01 to 1 μm, preferably 0.1 to 1 μm.
0.3 μm is preferable.

The charge transport layer comprises a charge transport material and a binder. The charge transport material is a material having a good transport property of the charge generated by the charge generation material, and for example, a hydrazone-based material,
Pyrazoline-based, PVK-based carbazole-based, oxazole-based, triazole-based, aromatic amine-based, amine-based, triphenylmethane-based, butadiene-based, stilbene-based, polycyclic aromatic compound-based, etc. It is necessary to. Preferred are butadiene-based and stilbene-based charge transfer agents, and specifically, Japanese Patent Application No. 4-
The charge transport material described in Japanese Patent No. 287983 can be used.

As the binder, the same binders as described above for the charge generation layer can be used, but polyvinyl acetal resin, styrene resin and styrene-butadiene copolymer resin are preferable. The binder is
It is desirable to use 0.1 to 10 parts by weight, preferably 0.1 to 1 part by weight, relative to 1 part by weight of the charge transport agent. The thickness of the charge transport layer after drying is 1 to 50 μm, preferably 10 to 30 μm.

Examples of combinations of these charge generating substances and charge transporting substances include combinations of fluorenone azo pigment (charge generating substance) and stilbene type charge transporting agent, bisazo type pigment (charge generating substance) and butadiene type, hydrazone type. The combination of the charge-transporting agents described above is preferable.

The persistent conductivity imparting agent and the electron acceptor described in the section of the single-layer photoconductive layer are added to the charge generation layer and the charge transport layer in the laminated photoconductive layer in the same proportions. However, it is preferably added to the charge generation layer.

When the single-layer photoconductive layer or laminated photoconductive layer is an organic photoconductive layer, dichloroethane, 1,1,2-trichloroethane, monochlorobenzene, tetrahydrofuran, cyclohexane, dioxane, or 1 is used as a solvent. , 2,3-trichloropropane, ethyl cellosolve, 1,1,1, -trichloroethane, methyl ethyl ketone, chloroform, toluene and the like may be used as a coating solution. The coating method may be a blade coating method, a dipping method, a spinner. A coating method and the like can be mentioned.

The photoconductive layer may be provided on the electrode via the charge injection control layer. The charge injection control layer is provided as needed, and is provided to control the charge injection property from the electrode to the photoconductive layer and adjust the voltage substantially applied to the information recording medium. However, in the information recording medium of the present invention, it is necessary to set the sensitivity of the photoconductive layer in the operating voltage region of the liquid crystal in the information recording layer. That is, the difference (contrast potential) between the potential (bright potential) applied to the information recording layer in the exposed portion and the potential (dark potential) applied to the information recording layer in the unexposed portion is made large in the liquid crystal operating region. Because it is necessary.

Therefore, for example, the dark potential applied to the liquid crystal layer in the unexposed portion of the photoconductive layer needs to be set to about the operation start potential of the liquid crystal, and 10 ⁵ V / cm to 10 V / cm is applied to the bulk of the photoconductive layer.
10 ^-4 to 10 ^-8 A under an electric field of ⁶ V / cm
The conductivity is required to the extent that a dark current of / cm ² is generated, and the range of 10 ^-5 to 10 ^-6 A / cm ² is preferable.
In the photoconductive layer having a dark current of 10 ^-8 A / cm ² or less, the liquid crystal layer is not aligned even in the exposed state, and in the photoconductive layer having a dark current of 10 ^-4 A / cm ² or more, the voltage is applied even in the unexposed state. At the same time, a large amount of current flows, the liquid crystal in the information recording layer is not aligned, and even if it is exposed, the difference in its transmittance cannot be obtained. The charge injection control layer is appropriately provided in relation to the characteristics of such an information recording medium. When it is necessary to keep the dark potential in the photoconductive layer low, the charge injection control layer is a layer having a charge injection preventing property. There are two types of charge injection prevention layers, a layer utilizing a so-called tunneling effect and a layer utilizing a rectifying effect, and the one described in Japanese Patent Application No. 4-287983 can be used.

Next, the information recording layer 11 described in the section of the first information recording medium is laminated on the photoconductive layer 14 in the same manner as the first information recording medium.

The electrode layers 13 and 13 'are made of the above-mentioned first material.
The same material and forming method as the electrode layer in the information recording medium of can be adopted, but when reading recorded information with transmitted light, transparency is required, and when reading with reflected light, either Whether one electrode layer is light reflective,
A light reflecting layer such as a dielectric mirror layer may be laminated on either one of the electrode layers. A substrate may be laminated on the electrode 13 on the information recording layer.

Next, in this second information recording medium, a transparent insulating layer may be provided between the photoconductive layer 14 and the information recording layer 11. When the transparent insulating layer is provided, it is particularly suitable when the photoconductive layer is an organic photosensitive layer formed by using a solvent, and the liquid crystal in the information recording layer is eluted by the interaction between the photoconductive layer and the information recording layer. Alternatively, when the information recording layer is formed on the photoconductive layer by coating, the photoconductive material is eluted by the solvent for forming the information recording layer to prevent image unevenness. When forming the transparent insulating layer, it is necessary that it is not compatible with either the organic photoconductive layer forming material or the information recording layer forming material. Further, in the case of having conductivity, the space charge is diffused and the resolution is deteriorated, so that the insulating property is required. However, since the transparent insulating layer lowers the distribution voltage applied to the liquid crystal layer or deteriorates the resolution, it is preferable that the film thickness is thin, and the thickness is preferably 2 μm or less.
In addition, the thinning causes not only the generation of image noise due to the interaction with time, but also the problem of penetration due to defects such as pinholes in the multilayer coating. Since the permeability varies depending on the solid content ratio of the material to be laminated and applied, the type of solvent, and the viscosity, the film thickness of the material to be laminated and applied is appropriately set. Further, in order to prevent these problems, the following materials may be laminated and used. Further, in consideration of the voltage distribution applied to each layer, it is preferable to use a material having a high dielectric constant as well as a thin film.

Such a transparent insulating layer is made of an inorganic material.
SiO ₂ , TiO ₂ , CeO ₂ , Al ₂ O ₃ , GeO ₂ , Si ₃ N ₄ , AlN, Ti
Alternatively, N 2 or the like may be used to form the layers by vapor deposition, sputtering, chemical vapor deposition (CVD), or the like. Further, an aqueous solution of polyvinyl alcohol, water-based polyurethane, water glass or the like may be used as a water-soluble resin having a low compatibility with an organic solvent, and 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, and in this case, it may be dissolved in a fluorine-based solvent and coated by a spin coating method, or laminated by a blade coating method, a roll coating method or the like. As the coatable fluorine resin, the fluorine resin described in Japanese Patent Application No. 4-24722 can be preferably used. When selecting a coating type transparent insulating material, the solvent does not dissolve the photoconductive layer, and does not dissolve in the material forming the information recording layer when forming the information recording layer by coating, or when coating. It is necessary that it does not dissolve in the solvent.

Further, in the case of an organic material which is formed into a film in a vacuum system, there is no fear of dissolving the photoconductive layer during the film formation. Of these, polyethylene, polypropylene, poly (monochlorotrifluoroethylene), polytetrafluoroethylene, etc. can be used as the material for forming the film by the vapor deposition method.
As a material for forming a film by the CVD method, polyparaxylene specifically described in Japanese Patent Application No. 4-24722 can be used. If the photoconductive layer is made of an inorganic material and does not interact with the information recording layer, it is not necessary to provide the transparent insulating layer. Next, a method of recording information on the second information recording medium of the present invention will be described with reference to FIG. First, when the information light 18 is incident while a voltage is applied between the electrodes 13 and 13 ′ by the power source, the photo carriers generated in the photoconductive layer 14 in the portion where the light is incident move due to the electric field formed by both electrodes. Then, by redistribution of the voltage, the liquid crystal phase in the information recording layer is oriented, and recording according to the pattern of the information light 18 is performed. The voltage may be applied for a predetermined time while the information light 18 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 determined by the operation of the liquid crystal. It is recommended to set it in the voltage range.

This information recording method is capable of planar analog recording, and recording at the liquid crystal particle level can be obtained, so that high resolution can be obtained, and the exposure pattern is retained as a visible image due to the orientation of the liquid crystal phase. To be done. Further, as the information input method, the same method as the method using the camera and the method described with the laser described in the section of the first information recording medium can be used. Further, the recording method using a laser can be similarly performed. Further, the spectral characteristics of the photoconductive layer do not need to be panchromatic, and may be sensitive to the wavelength of the laser light source. When the information recorded on the second information recording medium is read by transmitted light, it is reproduced in the same manner as the case of the first information recording medium shown in FIG.

If an insulating light reflecting layer is used instead of the transparent insulating layer, it becomes suitable for reading recorded information by reflected light. Examples of the insulating light reflecting layer include a dielectric mirror layer and a light-shielding light-shielding film. Examples of the dielectric mirror layer include those having a film thickness of λ / 4 and formed of, for example, a combination of silicon dioxide and titanium dioxide, or zinc sulfide and magnesium fluoride. As the light-shielding film having light reflectivity, for example, aluminum oxide, which is an insulating material, and germanium, which is a light-shielding material, are vapor-deposited at a rate of 50Å /
Second, germanium is vapor-deposited at a rate of 20 Å / sec at the same time to give a film thickness of about 1 μm. The recorded information is read by reflected light from the information recording layer side.

Further, the information recording medium of the present invention is used by being cut in an appropriate size in the layer width direction according to the use mode, and the inside of the information recording layer is exposed at the cut surface, Bleeding of the liquid crystal phase occurs during storage. When this bleeding phenomenon occurs, a problem arises in that when information is recorded, accurate information cannot be recorded at the edge of the information recording medium. In order to prevent this, after cutting the information recording medium into an appropriate shape, a resin layer may be similarly laminated on the cut surface by the coating method or the laminating method to protect the cut surface.

Further, the information recording medium of the present invention records electrostatic information in a state of being visualized by the orientation of the liquid crystal, but the information once oriented and visualized is not erased and a memory property is imparted. . To erase the memory, it is preferable to heat it to a high temperature near the isotropic phase transition, and it can be used again for information recording.

[0062]

In the first information recording medium of the present invention, the information recording layer is formed of a polymer liquid crystal exhibiting a smectic phase, so that heating is not required for information recording and the information is once recorded. Information can have a memory property, and since the second information recording medium has a photoconductive layer, it does not need to be combined with an optical sensor and can record information by itself. is there.

Further, in the information recording medium of the present invention, the information recording layer can be uniformly thinned by the coating technique.
A large-area information recording medium can be manufactured, and since information can be recorded at the liquid crystal molecule level, a high-resolution image can be recorded. Hereinafter, examples will be described. In the examples, “parts” means parts by weight and “%” means% by weight.

[0064]

Example 1 An indium tin oxide (ITO) film having a film thickness of 1000 Å was formed on a thoroughly washed glass substrate having a thickness of 1.1 mm by a sputtering method to obtain an electrode layer. 3 g of polymer liquid crystal LCP93 (trade name, manufactured by Merck) on the electrode
Was dissolved in 7 g of xylene, and using a blade coater,
It was applied and dried at 80 ° C. for 1 hour. The film thickness was 10 μm. (Fabrication of optical sensor) The following structure as charge generation agent

[0065]

[Chemical 5]

Using a mixed solvent of 3 parts of a fluorenone azo pigment (manufactured by Nippon Senshoku Co., Ltd.) having 1 part, a polyester resin (byron 200 manufactured by Toyobo Co., Ltd.) and 1,4-dioxane: cyclohexane = 1: 1. Solid content of 2% 1
The 00g solution was sufficiently dispersed with a paint shaker to form a coating solution, and ITO having a film thickness of 500Å and a resistance value of 80Ω / cm ²
The ITO side of the glass substrate having the film was applied using a blade coater with a gap of 2 mils, dried at 100 ° C. for 1 hour, and a charge generation layer having a film thickness of 0.3 μm was laminated.
On this charge generation layer, the following structure is used as a charge transfer agent.

[0067]

[Chemical 6]

25 parts of para-dimethylstilbene, 5 parts of polystyrene resin (HRM-3, manufactured by Denka), 1,
1,2-trichloroethane 102 parts, dichloromethane 6
8 parts of the coating solution is applied using a blade coater and dried at 80 ° C. for 2 hours to laminate a charge transport layer, and a light having a thickness of 20 μm composed of a charge generation layer and a charge transport layer. A conductive layer was provided to obtain an optical sensor.

Next, the obtained optical sensor and the information recording medium of the present invention produced as described above are arranged so as to face each other with a PET film of 10 μm as a spacer, and incorporated in the recording apparatus of FIG. Was positive and the information recording medium side was negative, and a DC voltage of 800 V was applied. With the voltage applied, exposure was performed from the photosensor side using a halogen lamp with an illuminance of 1000 lux as a light source for 0.1 seconds, and after the exposure was completed, the information recording medium was taken out and information recording was completed. The exposed portion became light transmissive, and the transmittance of light of 800 nm at this portion was 40%. On the other hand, the unexposed part had no light transmittance, and the transmittance of this part was only 10%.

A normal camera was used as an exposure method, and an object was photographed outdoors and in the daytime with an exposure f of 1.4 and a shutter speed of 1/60 seconds while a voltage of 1000 V was applied. After the exposure, the information recording medium was taken out, and an image having gradation was confirmed. Further, as a result of reading this information recording medium with a scanner using a CCD line sensor and further outputting with a sublimation printer, a hard copy having gradation and high resolution was obtained.

[0071]

Example 2 3 g of a polymer liquid crystal LCP94 (trade name, manufactured by Merck) and 1 g of a low-molecular liquid crystal (trade name E-31LV, manufactured by Merck) were dissolved in 10 g of xylene, and a blade coater was used. In the same manner as 1), apply on the electrode layer, and
It was dried at 0 ° C. for 1 hour to form an information recording layer having a film thickness of 10 μm.

An image similar to that of Example 1 was obtained when a subject was photographed in the daytime in the same manner as in Example 1 except that the applied voltage was set to 900V.

[0073]

Example 3 Polymer liquid crystal LCP93 (trade name, manufactured by Merck Ltd.) 3 g and polymethyl methacrylate (trade name Acrypet, manufactured by Mitsubishi Rayon Co., Ltd.) 2 g were dissolved in 5 g of methyl ethyl ketone, and a blade coater was used. 1
Similarly, apply on the electrode layer and dry at 80 ° C. for 1 hour,
An information recording layer having a film thickness of 6 μm was provided.

When the subject was photographed in the daytime in the same manner as in Example 1, an image similar to that in Example 1 was obtained.

[0075]

Example 4 Fluorine-containing resin CYTOP (trade name; Asahi Glass) on the photoconductive layer of the optical sensor prepared in Example 1.
Co., Ltd., water absorption 0.01%, specific resistance 1 × 10 ¹⁸ Ω · c
m) perfluoro (2-butyltetrahydrofuran)
Dissolve in, and the 4.5% solution is 1500r with a spinner.
pm, apply for 20 seconds, dry at 80 ° C for 1 hr,
A transparent insulating layer having a film thickness of 1 μm was formed.

Next, an information recording layer similar to that used in Example 3 was formed on the transparent insulating layer to a thickness of 6 μm, and an ITO film having a film thickness of 500 Å was sputtered on the information recording layer as an upper electrode. To form a film, and a second information recording medium of the present invention was produced.

An ordinary camera is used as the exposure method, and
With a voltage of 00V applied, exposure f = 1.4 and shutter speed 1/60 seconds were taken outdoors and in the daytime.
After the exposure, the information recording medium was taken out, and an image having gradation was confirmed. In addition, this information recording medium is CC
Read with a scanner using a D line sensor,
Furthermore, as a result of outputting with a sublimation printer, it has gradation,
A high resolution hard copy was obtained.

[Brief description of drawings]

FIG. 1 is a schematic view showing a cross section of an information recording medium of the present invention, where (a) shows a first information recording medium and (b) shows a second information recording medium.

FIG. 2 is a schematic diagram of an information recording device using an optical sensor.

FIG. 3 is a diagram for explaining a method of reproducing recorded information on an information recording medium with transmitted light.

FIG. 4 is a diagram for explaining an information recording method on a second information recording medium.

[Explanation of symbols]

1 is an optical sensor, 3 is an information recording medium, 11 is an information recording layer, 12 is an insulating light reflecting layer, 13 and 13 'are electrode layers, 1
4 is a photoconductive layer, 15 is a substrate, 18 is information light, 19 is a spacer, 21 is a light source, 22 is a shutter having a drive mechanism, 23 is a pulse generator (power source), 24 is a dark box, A is transmitted light, B is It is scattered light.

Claims (2)

[Claims] 1. An information recording medium, wherein an information recording layer made of a polymer liquid crystal exhibiting a smectic phase is laminated on an electrode layer. 2. An information recording medium in which an electrode layer, a photoconductive layer, an information recording layer, and an electrode layer are sequentially provided, and at least one of the electrodes is transparent, and the information recording layer is made of a polymer liquid crystal exhibiting a smectic phase. An information recording medium characterized by the following.