JPH02245735A - Information recording medium and information recording and reproducing method - Google Patents

Abstract

PURPOSE:To obtain the information recording medium which can record information by the orientation at the molecular level of a liquid crystal polymer by recording exposing patterns by the orientation of the liquid crystal polymer and then reproducing the recorded exposing patterns via a polarizing means. CONSTITUTION:The liquid crystal polymer layer 11 of the information recording medium 3 consists of a thermotropic liquid crystal and while this information recording medium 3 is heated, information light is made incident or the medium is heated in some time after the end of the exposing by the information light, by which the orientation of the liquid crystal polymer molecules is generated and the information light is recorded in the form of the orientation of the liquid crystal polymer. The reproduction of the information from the information recording medium 3 recorded with the information on the liquid crystal polymer layer 11 is easily executed by laser light 20, natural light, etc., via a polarizer in such a manner. The recording of the information by the orientation at the molecular level of the information is possible in this way and the information recording medium having the high definition to allow recording and reproducing even as character signals is obtd.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention records information at the molecular level of a liquid crystal polymer by recording an exposure pattern using an exposure recording method when voltage is applied by aligning the liquid crystal polymer. The present invention relates to information recording media capable of

[Conventional technology]

Conventionally, in electrophotography, a photoconductive layer is thinly deposited on an electrode layer, the entire surface of the photoconductive layer is charged, and then imagewise exposed.
An electrostatic latent image is optically formed on the photoconductive layer by leaking the charge in the exposed area, and a toner with a polarity opposite to the residual charge is attached, which is then electrostatically transferred to paper, etc., and developed. something is known. This is mainly used for copying, but it shortens the retention period of electrostatic charge in the photoconductive layer as a recording medium, and the toner is developed immediately after the electrostatic latent image is formed. If so, it is very unusable due to low sensitivity.

Furthermore, the TVjil imaging technology requires line-sequential scanning in order to extract and record the electrical image signals obtained by the image pickup tube. Line-sequential scanning is performed using an electron beam in a picture tube and a magnetic head for video recording, but because resolution depends on the number of scanning lines, it deteriorates significantly compared to planar analog recording such as silver halide photography. There is a problem.

Furthermore, TV imaging systems that utilize solid-state imaging elements, which have been developing in recent years, are essentially the same in terms of resolution, and the problems inherent in these technologies are that image recording is of high quality and resolution. The more complicated the processing process is, the simpler the process is, the more likely there is a lack of storage function or a basic deterioration of image quality.

[Problem to be solved by the invention]

The present inventors first placed a photoreceptor made of a photoconductive layer with an electrode on the front surface and a charge retention medium made of a charge retention layer with an electrode on the rear surface facing each other, and then After image exposure with a voltage applied, the charge retention medium is separated,
They discovered that information can be reproduced extremely clearly by amplifying the surface potential accumulated as image information on the surface of the charge retention layer and outputting the image reproduction, and they would like to apply for this charge retention medium (Japanese Patent Application No. 127555/1982).

An object of the present invention is to provide an information recording medium in which information can be recorded by orientation of a liquid crystal polymer at the molecular level.

[Means to solve the problem]

To this end, the information recording medium of the present invention is characterized in that a liquid crystal polymer layer is laminated on the electrode.

Further, the information recording and reproducing method of the present invention includes arranging a photoreceptor made of a photoconductive layer provided with an electrode on its front surface, and an information recording medium made of a liquid crystal polymer layer opposed to the photoreceptor and provided with an electrode provided on its rear surface. , image exposure is performed while heating the recording medium to its liquid crystal phase region with a voltage applied between both electrodes, and the exposure pattern is recorded by the orientation of the liquid crystal polymer, and then the information recording medium is separated and cooled or information is stored after exposure. The method is characterized in that the recording medium is cooled after being separated, and then the recorded exposure pattern is reproduced through a polarizing means.

Hereinafter, the constituent materials of the information recording medium of the present invention, the method for forming the same, the information recording method, and the information recording and reproducing method will be explained.

FIG. 1 is a cross-sectional view of an information recording medium of the present invention, and FIG. 2 is a cross-sectional view of another information recording medium of the present invention, in which 3 is an information recording medium, 11 is a liquid crystal polymer layer, 13 is an electrode, and 14 is an insulating layer,
15 is a support.

The information recording medium of the present invention records information on a liquid crystal polymer layer.

The liquid crystal polymer layer 11 uses thermotropic (heat-melting) liquid crystal. When a liquid crystal polymer is heated, it undergoes a phase transition from a solid state to a liquid crystal phase to a solution phase. For example, in the case of a polyester polymer, the viscosity becomes extremely low in the liquid crystal state and exhibits a nematic liquid crystal phase.

Specifically, polyester-based products include, for example, X7G (trade name, manufactured by Eastman Kodak Company), Econol (trade name, manufactured by Sumitomo Chemical Co., Ltd.), Xydar (trade name, manufactured by Dartco Nippon Petrochemical Co., Ltd.), Vectra (trade name, manufactured by Celanese Co., Ltd.), , manufactured by Polyplastics), Novakielate (manufactured by Mitsubishi Chemical Corporation), Rodran (manufactured by Unitika), Ul t
rax (manufactured by BASF), Idemitsu LCP (manufactured by Idemitsu Kosan), Toso LCP (manufactured by Toso), as well as main chain liquid crystal polymers such as polyesteramide and polyazomethine. Side-chain type liquid crystal polymers and liquid crystal copolymers in which mesogenic groups having liquid crystal properties are introduced into the backbone chains such as polymethacrylate, polyacrylate, polysiloxane, polypeptide, polyphosphazene, and polyethylimine can be used.

Furthermore, it is possible to use a mixture of two or more of the above-mentioned liquid crystal polymers, or a mixture of a low-molecular liquid crystal having liquid crystallinity in a polymer.

The liquid crystal polymer layer 11 shown in FIG. 1(a) is formed by coating the electrode substrate 13 with a liquid crystal polymer, and preferably has a thickness of 1 μm to several hundred μm.

In order to record information on an information recording medium made of a liquid crystal polymer formed in this way, the liquid crystal polymer that has been cooled and solidified is heated again to the liquid crystal phase temperature range while applying a voltage, or after applying the voltage, heating is performed. It is done by doing. The liquid crystal polymer layer may be heated, for example, by resistance heating provided in the support 15, or by providing means for heating only the information recording medium portion from the outside. As shown in Figure (b), the orientation of liquid crystal polymer molecules is changed in the voltage application section.

If the above-mentioned liquid crystal polymer has insulating properties in its solid state, it is best to coat it directly on the electrode substrate, but liquid crystal polymers with poor insulating properties can be coated on the electrode through an insulating layer as shown in Figure 2. applied.

The insulating layer 14 is made of a highly insulative insulating resin in order to suppress the movement of charges, and is required to have an insulating property with a specific resistance of 10 14 Ω·cm or more.

Further, the resin constituting the insulating layer is required to have heat resistance higher than the liquid crystal region temperature of the liquid crystal polymer, and must be able to retain information charges for a certain period of time in that temperature range.

Examples of such resins include fluororesins such as polytetrafluoroethylene, fluorinated ethylene propylene,
Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, polyimide resin, polyetheretherketone resin, polyparaxylylene, etc. can also be used.

First, the insulating layer 14 laminated on the electrode 13 and the liquid crystal polymer layer can be formed on the electrode by vapor deposition, sputtering, etc., or by dissolving it in a solvent and coating or dipping. Alternatively, a layer may be formed by attaching a film of the above polymer via an adhesive or the like.

The film thickness must be such that no charge tunneling phenomenon occurs, and the film thickness is preferably at least 1000 Å or more.

Further, it is preferable that the surface of the insulating layer is subjected to rubbing treatment or alignment treatment using an alignment agent or the like in advance.

Note that it is preferable to use a polyimide film as the insulating layer because it has heat resistance and can further enhance the alignment effect. It is also preferable to laminate film-like insulating layers with their orientation treatment directions perpendicular to each other.

The insulating layer prevents discharge charges from the electrodes and the photoreceptor (described later) from being injected into the liquid crystal polymer phase, and also prevents the orientation in the image exposure area by retaining charges emitted from the photoreceptor. This makes it possible to

The support 15 supports the information recording medium 3 with strength, and there are no particular restrictions on its material and thickness as long as it has a certain level of strength that can support the liquid crystal polymer layer. A rigid body such as a flexible plastic film, glass, or plastic sheet is used, and is required to have light transparency and heat resistance at the melting temperature of the liquid crystal polymer. Specifically, when the information recording medium 3 takes the form of a flexible film, tape, or disk, a flexible plastic film is used, and when strength is required, a rigid sheet, glass, etc. is used. Inorganic materials etc. are used.

In addition, on the other side of the support, if necessary, a layer having an antireflection effect may be laminated, or the thickness of the support may be adjusted to a level that can exhibit an antireflection effect, or a combination of both may be used. It is preferable to impart antireflection properties.

The electrode 13 is formed on the support 15 and needs to be transparent or semi-transparent, and as above, heat resistance is required, and the material is not limited as long as the specific resistance value is 10 hΩ・C11 or less. (, inorganic metal conductive films, inorganic metal oxide conductive films, organic conductive films such as quaternary ammonium salts, etc.) Such electrodes can be processed by thin deposition, sputtering, CVD, coating, plating, deimping, electrolytic polymerization, etc. The thickness of the film must be changed depending on the electrical properties of the material constituting the electrode and the voltage applied during information recording. It is formed on the entire surface between the layers or in accordance with the formation pattern of the liquid crystal polymer layer.

Next, a method for recording information on an information recording medium according to the present invention will be explained.

FIG. 3 is a diagram for explaining the information recording method, in which 1 is a photoreceptor, 5 is a former thick electrical layer support, 7 is a photoreceptor electrode, 9 is a photoconductive layer, and 17 is a power source.

First, a photoconductive layer support 5 made of glass with a thickness of 1 fi
A transparent photoreceptor electrode 7 made of indium oxide (CITO) with a thickness of 1,000 μm is formed, and a photoconductive layer 9 of about 10 μm is formed thereon to constitute the photoreceptor 1.

As shown in the same figure (A), 10μ
The information recording medium 3 is arranged with a gap of about m.

Next, as shown in FIG. 3B, a voltage is applied between the electrodes 7 and 13 by the iii source 17. If it is a dark place, the photoconductive layer 9
is a high-resistance material, so if the voltage applied to the gap is below the discharge starting voltage according to Paschen's law, no change will occur between ti, and if a voltage higher than the discharge starting voltage is applied to the gap by an external power supply. When this occurs, a discharge occurs, and charges are accumulated on the surface of the information recording medium, and this state continues until the voltage drops to the discharge starting voltage, resulting in fog charges.

Further, when recording on this information recording medium, it is necessary to heat the information recording medium, for example, by resistance heating (not shown) embedded in a support, and to heat the liquid crystal polymer to a temperature at which it exhibits a liquid crystal phase. In this temperature range state, when light 18 is incident from the photoreceptor 1 side, the photoconductive layer 9 in the portion where the light has entered
exhibits conductivity and discharge occurs, charges are accumulated on the surface of the insulating layer, and alignment of liquid crystal polymer molecules occurs at the charge accumulation site in the liquid crystal polymer layer. Further, even if there is a uniform fog charge in advance, charge is further accumulated in the area where light is incident, so information can be recorded based on the contrast with the unexposed area.

Also the statue as above! When formed by discharge of a charge,
There are some that operate at low voltage due to liquid crystal polymer, so
When setting the applied voltage, it is preferable to set the voltage distribution applied to the liquid crystal polymer layer within its operating voltage range by appropriately setting the voltage distribution between the photoreceptor, the air gap, and the information recording medium.

At the stage where information is recorded on the liquid crystal polymer layer in this way, the power supply 17 is turned off, the information recording medium 3 is peeled off from the photoreceptor l, and the recorded state in the liquid crystal polymer is cooled as shown in FIG. can be immobilized.

In addition, after peeling the information recording medium 3 from the photoreceptor by applying a voltage without heating as shown in FIG. It can also be fixed by cooling.

When this information recording method is used for planar analog recording, alignment at the liquid crystal polymer molecular level can be obtained, so high resolution can be obtained similar to silver salt photography, and the exposure pattern is preserved in the form of alignment in the liquid crystal polymer layer. It is stored for a long time because it is stored for a long time.

Methods for inputting information to the information recording medium of the present invention include a method using a high-resolution electrostatic camera and a recording method using a laser. The information light may be incident from the photoreceptor side or may be incident from the information recording medium side. First, high-resolution electrostatic cameras use a photoreceptor l and an information recording medium 3 instead of the photographic film used in ordinary cameras.
The recording member is formed by a mechanical shutter or an electric shutter. In addition, a prism separates the optical information into R, G, and B light components, and a color filter is used to extract them as parallel light. One frame is formed with 3 cents of information recording media that has been separated into R, G, and B, or 1 frame is used. By arranging R, G, and B images on a plane and making one frame worth 1 cent, it is also possible to create a color image.

For recording methods using lasers, the light sources include argon laser (514,488 nm), helium-neon laser (633 nm), and semiconductor laser (780 nm).
(nm, 810 nm, etc.) can be used, and a voltage is applied to the photoreceptor and the information recording medium with their surfaces brought into close contact with each other or facing each other at a fixed interval. In this state, laser exposure corresponding to image signals, character signals, code signals, and line drawing signals is performed by scanning. Analog recording such as images is performed by modulating the light intensity of the laser, and digital recording such as characters, codes, and line drawings is performed by ON-OFF control of the laser light. Further, halftone dots in an image are formed by applying dot generator ON-OFF control to laser light.

Incidentally, the spectral characteristics of the photoconductive layer in the photoreceptor do not need to be the same as those of Mattissos, but only need to be sensitive to the wavelength of the laser light source.

Next, a method for reproducing information recorded on the information recording medium will be explained.

FIG. 4 is a diagram showing an example of a potential reading method in an information recording and reproducing method, and the same numbers as in FIG. 1 indicate the same contents. In addition, in the figure, 20 is a laser 21, a 1/4 wavelength plate,
22 is an analyzer, and 23 is a photodetector.

To reproduce information from an information recording medium on which information is recorded,
In addition to grounding the electrode in the information recording medium, the laser 2
0 is scanned from the bottom of the information recording medium, and 1
A polarizing means consisting of a 74 wavelength plate 21 and an analyzer 22 is placed in the optical path, and the polarized laser beam is detected by a photodetector 23, thereby making it possible to reproduce the information stored in the liquid crystal polymer layer.

In the case of reproduction using natural light, it is preferable to scan the information recording medium with a laser beam through a polarizing means and reproduce the transmitted light in the same manner as described above.

[Action and effect of the invention]

The liquid crystal polymer layer in the information recording medium is made of thermodropink (heat-melting type) liquid crystal, and when the liquid crystal phase temperature is taken as, for example, a polyester system exhibits a nematic liquid crystal phase,
In this liquid crystal state, the viscosity is extremely low. When a voltage is applied at this stage, the molecules are oriented, and when the temperature is lowered, the oriented molecular arrangement remains and has a memory effect.

By using an information recording medium having this liquid crystal polymer layer, the present invention allows information light to be incident on the information recording medium while heating it, or after the exposure with the information light is completed.
It has been discovered that by heating the liquid crystal polymer for a certain period of time, the molecules of the liquid crystal polymer are caused to align, and information light can be recorded in the form of the alignment of the liquid crystal polymer.

In order to reproduce information from an information recording medium in which information is recorded in a liquid crystal polymer layer in this way, information can be easily reproduced using laser light, natural light, etc. through a polarizer, and the information can be easily reproduced in units of electrostatic charge. Information is recorded at the level of liquid crystal polymer molecules, and the recorded information is fixed by cooling the molecular arrangement of the polymer, so it is stably stored. Further, information can be recorded as a continuous tone image, and the information recording medium can be used as a high-resolution information recording medium that can also be recorded and reproduced as a (0.1) signal or character signal.

Examples will be described below.

[Example 1] An indilum tin oxide (ITO) electrode is laminated to a thickness of 1000 nm on a glass substrate having a thickness of 1II111 by sputtering. On the electrode, a liquid crystal polymer (phase transition temperature °C, g36n108i) having a repeating unit consisting of 7 acrylate as a main skeleton and a mesogenic group was made into a 30% solution in a methyl ethyl ketone mixed solvent and coated with a blade coater to give a dry film thickness of 10 μm. The information recording medium of the present invention was prepared by applying the coating as described above.

[Example 2] As shown in FIG. 3, the photoreceptor 1 manufactured in Reference Example 1 described later and the information recording medium manufactured in Example 1 were
Using a 0 μm polyester film as a spacer, the information recording medium surface was placed opposite to the photoconductive layer surface of the photoreceptor, and the information recording medium was placed on a grounded heating plate (not shown) at 0 to 50°C, and then the information recording medium was placed between the two electrodes. to the negative side of the photoreceptor,
With the liquid crystal polymer layer side facing positive, a DC voltage of 600 V was applied, and while the voltage was being applied, exposure was performed from the photoconductor side for 1 second using a halogen lamp with an illuminance of 1000 lux as a light source.
Information was recorded on the liquid crystal polymer layer.

As shown in FIG. 4, the exposure pattern on the liquid crystal polymer layer of the information recording medium with information recorded in this manner could be clearly reproduced using an argon laser 20.

[Reference example]

Poly-N-vinylcarbazole 10g (Seinan Kaori Co., Ltd.)
(manufactured by Toyobo Co., Ltd.), 10 g of 2,4.7-trinitride fluorenone, 2 g of polyester resin (binder: Byron 200 manufactured by Toyobo Co., Ltd.), 90 g of tetrahydrofuran (THF)
A mixed solution having the composition was prepared in a dark place, and InzOs-5
nO□ was applied to a spuntered glass substrate (In thickness) with a film thickness of about 1000 using a doctor blade.
The mixture was dried with ventilation at 0° C. for about 1 hour to obtain a photosensitive layer having a photoconductive layer with a thickness of about 10 μm. In addition, in order to completely dry the sample, it was further air-dried for one day before use.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of an information recording medium of the present invention, FIG. 2 is a schematic cross-sectional view of another information recording medium of the present invention, FIG. 3 is a diagram for explaining an information recording method, and FIG. FIG. 3 is a diagram for explaining an information reproduction method. 1 is a photoreceptor, 3 is an information recording medium, 5 is a photoconductive layer support,
7 is a photoreceptor electrode, 9 is a photoconductive layer, 11 is a liquid crystal polymer layer,
13 is an electrode, 15 is a support, 17 is a power source, 18 is a pattern exposure light, 20 is a laser beam, 21.22 is a polarizing means,
23 is a photodetector.兇匈(a) 3rd fig.(c) (Jyosoku) Ura zu(ka) (82)

Claims (2)

[Claims] (1) An information recording medium characterized in that a liquid crystal polymer layer is laminated on an electrode. (2) A photoreceptor made of a photoconductive layer with an electrode provided on the front surface and an information recording medium made of a liquid crystal polymer layer with an electrode provided on the rear surface facing the photoreceptor are arranged, and a voltage is applied between the two electrodes. Image exposure is carried out while heating the recording medium to its liquid crystal phase region while applying a . and then reproducing the recorded exposure pattern through a polarizing means.