JPS61252530A - Electrode construction for liquid crystal memory - Google Patents

Abstract

PURPOSE:To make possible the recording and reproducing of information, signal, etc. by fixing a storage layer consisting of microcapsules sealed therein with the phase transition type liquid crystal by heat and light by the binder incorporated therein with a conductive material on the transparent electrodes provided on the surface of a thin-wall plate-shaped substrate formed of an insulating material. CONSTITUTION:A liquid crystal memory 1 consists of the storage layer 4 fixed with the microcapsules on the surface of the disk substrate 2 and the belt-like electrode 5. The storage layer 4 is coated in the stage of mixing the microcapsules 10 and the binder 11 into the recess 6 of the substrate 2. The microcapsules 10 are solidified by the solidification of the binder 11. Erasing of the recorded information is executed by connecting the output terminal of a high-frequency generator 20 to the belt-like electrodes 5, 5 and impressing AC of a high frequency, etc. between the electrodes. The liquid crystal molecules are replaced on the plane of the substrate 2 by the high frequency, by which said molecules are made transparent and the storage is erased. Laser light is irradiated on the position of the storage layer 4 corresponding to the subtracted fresh information to heat said position in succession of the above so that the liquid crystal 12 is clouded and the fresh information is recorded by the photothermal effect.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electrode structure of a liquid crystal memory that can record and reproduce information by irradiating a storage layer in which a photothermal phase change type liquid crystal is encapsulated with a laser beam, and particularly relates to A pair of transparent electrodes is provided on the surface or inside of a thin plate-like substrate, and a conductive binder is placed between these transparent electrodes to form a memory layer by fixing microcapsules filled with liquid crystal, The present invention relates to an electrode structure of a liquid crystal memory that enables information to be recorded and reproduced by irradiating the microcapsules of the storage layer with laser light, and which enables information to be erased by applying alternating current to the transparent electrode.

[Conventional technology]

Optical disk memory is known as a thin plate-shaped storage medium that can record, reproduce, or re-record a large amount of information. This optical disk memory consists of forming an optical recording thin film by vapor depositing a material with a remarkable magneto-optical effect on a disk base material in which grooves of a certain width are formed concentrically or spirally. It has a structure coated with a protective layer of resin.

When writing information to such optical disk memory,
Recording light emitted from a laser is incident on the disk base material side, and by locally changing the refractive index of the recording thin film due to the heat of the laser light, minute recording dots of varying shading are formed along the grooves, and information is recorded. Recording is in progress.

On the other hand, when reading information from an optical disk memory, the information is read by irradiating light into the groove, allowing the reflected light from the groove to enter a photoelectric conversion means, and converting it into an electrical signal. .

[Problem that the invention seeks to solve]

Although the above-mentioned optical disk memory can record and reproduce a large amount of information, the optical recording material is expensive, the process of forming the optical recording thin film is complicated, and reading errors may occur. It is necessary to prevent dust from adhering to the recorder, which causes problems such as troublesome storage and handling, and the need to write the recorded information on a label each time it is recorded. there were.

Incidentally, known techniques using liquid crystal as a recording medium include those described in JP-A-59-104625 and JP-A-59-94733, but the manufacturing technology and manufacturing process are difficult. Ta.

The present invention has been made in view of the above-mentioned problems, and it is possible to record and reproduce information, symbols, etc. by utilizing the property of a photothermal layer transition type liquid crystal that changes from transparent to cloudy due to photothermal treatment, and allows the liquid crystal to become transparent and cloudy. An object of the present invention is to provide an electrode structure for a liquid crystal memory that enables erasing of information, etc. by doing so.

[Means to solve the problem]

The electrode structure of the liquid crystal memory of the present invention, which solves the above problems, has a transparent electrode on the surface of a thin plate-like substrate made of an insulating material, and a binder mixed with a conductive substance on the transparent electrode to generate light and heat. A storage layer made of microcapsules encapsulating a phase change liquid crystal is fixed thereon, a transparent electrode and a transparent cover are sequentially provided on the storage layer, strip-shaped electrodes are provided on both sides of the substrate, and each strip-shaped electrode is attached to each of the strips. It is characterized by being electrically connected to transparent electrodes.

[Effect]

In this liquid crystal memory, information is stored by irradiating the surface of the storage layer with a powerful laser beam, heating the liquid crystal within the microcapsules in the required area with the laser beam, and then cooling the liquid crystal.

In addition, the laser beam is weakened and irradiated onto the storage layer of the liquid crystal memory, and the recorded content recorded on the storage layer is read by the reflected laser beam.

In order to erase the information once recorded, alternating current such as high frequency is applied to the strip electrode to apply alternating current to the storage layer between the transparent electrodes and align the directionality of the liquid crystal inside the microcapsule. After that, it can be heated with laser light and recorded again.

〔Example〕

Hereinafter, the present invention will be explained according to illustrated embodiments.

FIG. 1 is a plan view showing a first embodiment of the present invention. 1st
In the figure, the liquid crystal memory l is a memory formed by forming a hole 3 in the center of a disc-shaped disc substrate 2 made of an insulating material such as plastic, and fixing microcapsules to be described later on the surface of the disc substrate 2. A layer 4 and a strip-shaped electrode 5 made of a conductive material having a narrow width and concentric with the hole 3 are provided. Further, the strip electrode 5 is also provided on the surface of the disk substrate 2 on the opposite side from the storage layer 4.

FIG. 2 is a sectional view taken along line A--A in FIG. 1.

The storage layer 4 is provided between transparent electrodes 7.8 in a recess 6 provided in the disk substrate 2, and a cover 9 is attached to cover the recess 6, and the transparent electrode 7.8 is electrically conductive. These electrodes are each electrically connected to strip-shaped electrodes 5.5 formed of strip-shaped material.

FIG. 3 is an enlarged cross-sectional view of the storage layer 4 described above.

This storage layer 4 is made up of microcapsules 1o and an adhesive binder 11, and the microcapsules 10 and binder 11 are applied in a mixed state into the recesses 6 of the disk substrate 2, and when the binder 11 is solidified, the microcapsules are 1o is fixed. This microcapsule 1
o is made of a transparent conductive material, and liquid crystal 12 is sealed inside. This liquid crystal 12 is made by mixing a cholesteric liquid crystal into a nematic liquid crystal whose dielectric anisotropy is negative, and has the property of changing its phase by photothermal action, and can maintain a memory state by the photothermal effect. The binder 11 is mainly composed of polyvinyl alcohol, starch paste, polyacrylamide, etc., and is made conductive by mixing powders such as indium oxide and tin oxide, and when the main components dry, the microcapsules 10 are formed. It can be attached and fixed to the disk substrate 2. The cover 9 is fixed to the surface of the memory layer 4 so as to be in close contact with the surface of the storage layer 4 via the transparent electrode 8.

FIG. 4 is a block diagram showing the structure of the writing and reproducing section of the liquid crystal memory 1. As shown in FIG. The rotation of a disk motor 15 having a rotating shaft that fits into the hole 3 of the disk substrate 2 is controlled by a motor servo circuit 16. The recording/reproducing head 17 includes a semiconductor laser, a Pin diode, and an optical system that focuses the laser beam from the laser onto the storage layer 4 and provides information from the storage layer 4 to the Pin diode. The recording/reproducing head 17 is movable in the diametrical direction of the disk substrate 2 by a head drive motor 18. This head drive motor 18 is connected to the head drive motor control circuit 1.
The drive is controlled by 9. The high frequency generator 20 is used to erase information stored in the storage layer 4 of the liquid crystal disk memory 1, and its output can be supplied between the strip electrodes 5.5. Pi of the recording/reproducing head 17
The output signal from the n-diode is given to a regenerative amplifier circuit 21, amplified, and then supplied to a reproduced signal processing circuit 22 and a head drive motor control circuit 19, where it is converted and reproduced into a predetermined information signal. There is. The recording signal is processed by the recording signal processing circuit 23 and sent to the laser drive circuit 2.
4, and the laser drive circuit 24 is designed to drive the semiconductor laser of the RAD 17 for recording and reproduction. The motor servo circuit 16, head drive motor control circuit 19, high frequency generator 20, reproduction signal processing circuit 22, and recording signal processing circuit 23 are controlled by a control module ff125 composed of a microprocessor or the like. Note that 26 is an operation command from the outside.

Next, the operation of this embodiment will be explained.

The liquid crystal disk memory 1 is fitted onto the rotating shaft of the disk motor 15 to rotate the disk motor 15, and other circuits are put into operation.

When information to be recorded is input to the recording signal processing circuit 23, it is processed and provided to the laser drive circuit 24. A signal from the laser drive circuit 24 is applied to the semiconductor laser of the recording/reproducing head 17 to strongly excite the semiconductor laser. Then, the storage layer 4 on the disk substrate 2 is irradiated with a laser beam whose drive is controlled by the laser drive circuit 24 . The liquid crystal 12 in the microcapsule IO fixed in the storage layer 4 is heated by laser light,
After this, when the laser beam is removed and the storage layer 4 is cooled, the portion of the liquid crystal 12 irradiated with the laser beam becomes cloudy, indicating that information has been recorded. That is, before being heated with laser light, the liquid crystal 12 has a grandshuan structure with its helical axis parallel to the disk substrate 2 and is transparent; When the liquid crystal 12 returns to the link phase, it becomes a focal conic structure in which the directions of the helical axes are random due to thermal disturbance, and the liquid crystal 12 becomes cloudy. The structural state of the liquid crystal 12 due to this photothermal effect is maintained as long as it is not heated again by laser light, so that information can be recorded.

When reading information from the liquid crystal disk memory 1, the output of the semiconductor laser of the recording/reproducing radar 17 is weakened to emit a laser beam, which is irradiated onto the storage layer 4 using an optical system. When the reflected laser light from the storage layer 4 is similarly applied to the Pin diode using an optical system, it is converted into an electric signal, which is regeneratively amplified by the regenerative amplifier circuit 21 and supplied to the regenerative signal processing circuit 22 . Reproduction signal processing circuit 22
The signal is then processed and converted into the necessary information.

Furthermore, in order to erase the recorded information, the output end of the high frequency generator 20 is connected to the strip electrode 5.5, and an alternating current such as a high frequency is applied between the strip electrodes 5.5. In this way, the liquid crystal molecules are rearranged on the plane of the disk substrate 2 by the high frequency, returning to a transparent Grand Chouan structure, and the stored numbers are erased. Then, a laser beam is irradiated to the position of the storage layer 4 corresponding to the new information subtracted to heat the liquid crystal 12, and the liquid crystal 12 becomes cloudy due to the photothermal effect, thereby allowing new information to be recorded.

In addition, since a liquid crystal is used in this embodiment, as shown in FIG. 5, characters, symbols, etc. can be written on it, and it can be used in place of headings and labels.

According to this embodiment, since it is configured as described above, it is rewritable with a liquid crystal, is inexpensive, and is easy to handle.
Since it is a liquid crystal, it is highly stable (there is no need to transport it in a special container, etc.), and it can also be used in place of headings and labels, allowing visual confirmation of information.

FIG. 6 is a plan view showing a second embodiment of the liquid crystal memory according to the present invention.

In FIG. 6, a liquid crystal memory 31 is formed of a storage layer 34 surrounded by a frame 33 and a strip of conductive material on the surface of a thin rectangular card substrate 32 made of an insulating material such as transparent plastic. A strip electrode 35 is provided.

This strip-shaped electrode 35 is formed by applying or pasting a conductive material close to and parallel to the long side of the card substrate 32.

FIG. 7 is a sectional view taken along line 1-1 in FIG. 6.

In the liquid crystal memory 31, metallic transparent electrodes 33, 33 are embedded in a card substrate 32 at intervals, and a storage layer 34 is embedded between these transparent electrodes 33. A transparent cover 39 to cover the electrode 33
is attached, and a strip electrode 35 is attached on the back side of the card board 32.
A strip electrode 35 is provided at the same position. Strip electrode 35
．． 35 are electrically connected to transparent electrodes 33 and 33, respectively.

FIG. 8 is an enlarged cross-sectional view of the storage layer 34 described above. This memory layer 34 consists of microcapsules 40 and an adhesive binder 41. The microcapsules 40 and binder 41 are mixed and applied to the recessed portions of the card substrate 32, and as the binder 41 solidifies, the microcapsules 40 are Fixed. This microcapsule 4
0 is made of a transparent conductive material, and a liquid crystal 42 is sealed inside. This liquid crystal 42 is made by mixing a cholesteric liquid crystal into a nematic liquid crystal whose dielectric anisotropy is negative, and has the property of changing its phase by photothermal action, and can maintain a memory state by the photothermal effect. The binder 41 is mainly composed of polyvinyl alcohol, starch paste, polyacrylamide, etc., and is made conductive by mixing powders such as indium oxide and tin oxide, and when the main component dries, the microcapsules 40 are formed. Card board 4
2. Pasting can be fixed. And cover 39
is fixed in close contact with the surface of this storage layer 34.

FIG. 9 is a block diagram showing the configuration of the recording and reproducing section of the liquid crystal memory 31. In FIG. 9, the mechanism for transporting the liquid crystal memory 31 and the like are omitted.

The liquid crystal memory 31 is supplied by a transport mechanism (not shown) as indicated by the arrow a, and is discharged as indicated by the arrow. It may be composed of a motor, etc.
By rotating a capstan 45A provided on the rotating shaft in forward and reverse directions, the liquid crystal memory 31 can be moved forward and backward as shown by arrow C in the figure. This card drive motor 4
5, drive control is performed by a card drive motor control circuit 46. 47 is a recording/reproducing head;
The recording/reproducing head 47 includes a semiconductor laser 47A that generates laser light, a photoelectric conversion element 47B such as a Pin diode that converts reflected light from the liquid crystal memory 31 into an electrical signal,
The laser light from the semiconductor laser 37A is transferred to the liquid crystal memory 3.
It is configured to include an optical system 47C that focuses on one memory layer 34 and guides reflected light from the memory layer 34 to a photoelectric conversion element 47B. This recording/reproducing head 47 can be moved forward and backward as indicated by arrow d by a feed mechanism 48A connected to the rotating shaft of a head drive motor 48.

The head drive motor 48 is connected to the head drive motor control circuit 4
Drive control is performed by 9.

The AC generating circuit 50 is used to erase information stored in the storage layer 34 of the liquid crystal memory 31, and its output can be supplied between the strip electrodes 35 and 35. The output signal from the photoelectric conversion element 37B of the recording/reproducing head 47 is given to the reproduction amplifier circuit 51, where it is amplified and then sent to the reproduction signal processing circuit 52 and the head drive motor control circuit 49.
The signal is supplied to the reproducing signal processing circuit 52, which converts and reproduces the signal into a predetermined information signal, and outputs the signal as a reproduced signal. The recording signal is processed by the recording signal processing circuit 53 and given to the laser drive circuit 54.
is designed to drive the semiconductor laser 47A of the recording/reproducing head 47.

The operation of the card drive motor control circuit 46 , head drive motor control circuit 49 , AC generation circuit 50 , reproduction signal processing circuit 52 , and recording signal processing circuit 53 is controlled by a control device 55 . The control device 55 is composed of a microprocessor sensor, etc., and this control device 55 receives commands 56 from the outside.
Each of the above circuits is controlled according to an operation control procedure based on the following. Note that the signal given from the regenerative amplifier circuit 51 to the head drive motor control circuit 49 is used for tracking the head 47.

Next, the operation of this embodiment will be explained.

When the liquid crystal memory 31 is inserted through a predetermined insertion slot (not shown), the liquid crystal memory 31 is sent to the recording/reproducing section by a feeding mechanism (not shown), and enters the state of the recording/reproducing section.
Next, when a command 56 is input from the outside, the control device 55 operates and controls a predetermined circuit in accordance with the command.

First, we will explain the operation when recording.

When information to be recorded (recording signal) is input to the recording signal processing circuit 53, it is processed and provided to the laser drive circuit 54. The signal from the laser drive circuit 54 is applied to the semiconductor laser 47A of the RAD 47 for recording and reproduction, and strongly excites the semiconductor laser 47A. Then, the laser light driven and controlled by the laser drive circuit 54 hits the card board 32.
The upper storage layer 34 will be irradiated. Thus, the card drive motor 45 is controlled by the card drive motor control circuit 4.
6 to move the liquid crystal memory 31 in the C direction, and drive the head drive motor 48 via a head drive motor control circuit 49 to move the head 14.
is moved in the d direction to irradiate a predetermined position with laser light.

The liquid crystal 42 in the microcapsule fixed in the storage layer 34 is heated by the laser beam, and when the laser beam is removed and the storage layer 34 is cooled, the liquid crystal 42 in the area irradiated with the laser beam becomes cloudy. The information will be recorded. That is, the liquid crystal 42 before being heated with laser light
The pongee made of pongee is transparent with a grandshuan structure parallel to the card substrate 32, but when irradiated with laser light, the liquid crystal 42
When it is turned into a liquid and then cooled to return to the cholesteric phase, a focal conic structure with random pongee orientation due to thermal disturbance occurs, and the liquid crystal 42 becomes cloudy. The structural state of the liquid crystal 42 due to this photothermal effect is maintained as long as it is not heated again by laser light, so that information can be recorded. The records are formed as minute recording dots that are both cloudy and transparent on a fixed line.

Next, the operation when reading information from the liquid crystal memory 31 will be explained.

A control signal is given from the control device 55 to the recording signal processing circuit 53 to control the laser drive circuit 54, and the laser drive circuit 54 is used for recording and reproduction.
The output of the semiconductor laser 47A of No. 7 is weakened to emit laser light, which is irradiated onto the storage layer 34 via the optical system 47C. When the reflected laser light from the storage layer 34 is similarly applied to the photoelectric conversion element 47B using the optical system 47C, the reflected laser light is converted into an electric signal, which is regenerated and amplified by the regenerative amplification circuit 51 to produce a reproduced signal. The signal is supplied to the processing circuit 52. The reproduced signal processing circuit 52 processes the signal and converts it into necessary information. At this time as well, information at a predetermined position can be read by driving the card drive motor 45 and head drive motor 48 in the same manner as described above.

The operation when erasing recorded information will be explained.

To erase recorded information, the AC generating circuit 50
The output end of is connected to the strip electrodes 35.35, and an alternating current such as high frequency or low frequency is applied between these strip electrodes 35.35. In this way, the liquid crystal molecules are rearranged on the plane of the card substrate 32 by the alternating current, returning to a transparent Grandshuan structure, and the stored information is erased. Thereafter, a laser beam is irradiated to the position of the storage layer 34 corresponding to the new information to heat the liquid crystal 42, and the liquid crystal 42 becomes cloudy due to the photothermal effect, thereby making it possible to record new information.

In this embodiment, since the liquid crystal 42 is used for the storage layer 34, as shown in FIG. 10, characters, symbols 57, etc. can be written on it, and headings etc. can be displayed, so that it can be used in place of a label. There are advantages.

FIG. 11 is a sectional view showing a third embodiment of the present invention.

The liquid crystal memory 61 has a storage layer 64 surrounded by a frame 63 made of an insulating material on the surface of a thin rectangular card substrate 62 made of an insulating material such as plastic, and this storage layer 64 is connected to a transparent electrode 67. .67, and a strip electrode 65 is provided near it, and this memory layer 64 is formed by fixing the same microcapsules as in the second embodiment to the surface of the card substrate 62. The frame 63 is fixed to the surface of the card substrate 62 using an insulating material, and a transparent cover 69 is attached so as to span the frame 63 and cover the transparent electrode 67 provided on the surface of the storage layer 64. It is.

According to this third embodiment, manufacturing becomes easy and costs can be reduced.

〔Effect of the invention〕

Since the present invention is constructed as described above, it is rewritable using a liquid crystal, is inexpensive and easy to handle, is highly stable because it is a liquid crystal, does not need to be transported in a special container, etc. Since the heading can be used in place of a label, information can be confirmed visually, and the area occupied for storage can be reduced. Further, according to the present invention, there is an advantage that the entire liquid crystal can be made transparent by applying alternating current to the strip electrode.

[Brief explanation of drawings]

1 is a plan view showing a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the arrow A-A in FIG. 1, FIG. 3 is a cross-sectional view showing an enlarged storage layer, and FIG. The figure is a block diagram showing the recording/reproducing means used in the first embodiment, FIG. 5 is a plan view showing an example of use in which it can be used as a label, and FIG. 7 is a sectional view taken from 1-1 in FIG. 6, FIG. 8 is an enlarged sectional view of the storage layer, and FIG. 9 is a block diagram showing the recording/reproducing means used in the second embodiment. FIG. 10 is a plan view showing an example of use as a label substitute, and FIG. 11 is a sectional view showing a third embodiment of the present invention. 1.31.61--・LCD memory, 2.32.62-
・-Card board, 33.63・--Frame, 4, 34
, 64----one memory layer, 5.35.65--band-shaped electrode, 7,8--transparent electrode, 10.40--
Microcapsule, 11.41--Binder, 12
．． 42-・Liquid crystal.

Claims (1)

[Claims] A transparent electrode is provided on the surface of a thin substrate made of an insulating material, and a microcapsule containing a photothermal phase change type liquid crystal is fixed onto this transparent electrode using a binder made of a conductive material to form a memory layer. , a cover is attached onto the storage layer via a transparent electrode, strip-shaped electrodes are provided on both sides of the substrate, and both strip-shaped electrodes and both transparent electrodes are electrically connected, respectively. Electrode structure of liquid crystal memory.