JPH08271865A - Liquid crystal board - Google Patents

Abstract

PURPOSE: To provide a liquid crystal board with which uniform writing lines and images are obtainable on a display screen and which has excellent writing feel by providing the opposite side of this display board with a cushion material layer. CONSTITUTION: A specific soln. is applied as a transparent high electric resistance layer 8 on a conductive layer 3 of a vapor deposited aluminum film formed by consisting a base material 2 of a polyethylene terephthalate film and the conductive layer 3 of a vapor deposited aluminum layer and is dried and cured. Further, a specific soln. is applied as a liquid crystal dispersed polymer 6 prepd. by finely dispersing liquid crystal drops 5 into a polymer matrix 4 on this transparent high electric resistance layer 8 and is dried and cured. A cushion material 41 consisting of a polyurethane foam is stuck by using a tacky adhesive on the outer side of the base material 2 of the liquid crystal sheet. Further, a conductive nonwoven fabric as a conductive member 42 is stuck as hemming of a board screen 18 consisting of a transparent insulator layer 7 and is simultaneously brought into contact with the conductive layer 3, by which this fabric is stuck to the cushion material 41. The laminated formed in such a manner is stuck to a substrate 43.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a liquid crystal board. More specifically, the present invention relates to an externally charged liquid crystal board capable of displaying or erasing an image by utilizing the electro-optical effect of changing the light scattering state of liquid crystal by applying or removing electrostatic charge.

[0002]

2. Description of the Related Art Conventionally, many display devices using a liquid crystal display element utilizing the electro-optical effect of liquid crystal have been proposed. Above all, a liquid crystal display device using a liquid crystal dispersed polymer layer in which liquid crystal is finely dispersed in a polymer matrix has been proposed as a liquid crystal display device having a simple structure and capable of obtaining a large board screen. For example, JP-A-61-83521 and JP-A-3
JP-A-43715 discloses a liquid crystal display device in which an electrostatic charge is applied from the outside of a display screen to cause a phase change of a liquid crystal or change an alignment state to perform display. However, these liquid crystal display devices cannot display or delete a handwritten image on a display screen from outside the liquid crystal display element.

The liquid crystal display device described in Japanese Patent Laid-Open No. 61-83521 displays and erases a recorded image by applying and removing an electrostatic charge from the outside of the display screen of a liquid crystal display element by a corona flow. It is a thing. However, when the present inventors examined this liquid crystal display device, when a static charge was applied to the display screen, the cholesteric liquid crystal could undergo a phase change to form a recorded image. Could not be restored and the recorded image could not be erased. In order to erase the recorded image, it is necessary to heat the liquid crystal to a temperature higher than the phase transition temperature or to add an AC electric field by using a new conductive sheet, and in order to perform repeated display, it is applied first. It has been found that a complicated operation is required for repeatedly displaying and erasing the recorded image, such as displaying after removing the electrostatic charge.

In the liquid crystal display device described in Japanese Unexamined Patent Publication No. 3-43715, when an electrostatic charge is applied from the outside of the display screen by various charging methods, the liquid crystal is aligned and the light scattering state in the liquid crystal display element is caused. The recording image is changed to obtain a recorded image. In order to erase the recorded image obtained in this way, it is necessary to apply an opposite charge equal to the charged amount to only the recorded image portion. Since the charge amount becomes slightly larger or smaller than the charged amount, it is difficult and cannot be easily erased. In addition, there is a disadvantage that the memory property of the recorded image is short in a high humidity environment at a temperature of 20 ° C. and a relative humidity of 90%.

For this reason, even if an attempt is made to obtain a handwritten liquid crystal board using the above-mentioned liquid crystal display device, the former requires a complicated display and erase method, and it is easy to repeatedly display and erase from the outside of the board screen. However, in the latter case, the recorded image cannot be erased substantially, and the durability of the liquid crystal board and the memory property of the recorded image in the environment of high humidity are also present. There is a problem in terms of performance that is short. Therefore, it was not possible to obtain a handwritten liquid crystal board which is satisfactory in terms of operation and durability and performance of the liquid crystal board.

[0006]

The present applicant has studied such problems, and has already disclosed in JP-A-05-224182 that a transparent high electric resistance layer and a liquid crystal are finely dispersed in a polymer matrix on a conductive layer. Disclosed is an externally charged liquid crystal display device in which a liquid crystal dispersed polymer layer and a transparent insulator layer are sequentially laminated. Further, in Japanese Patent Laid-Open No. 05-281530, using such a liquid crystal display element, a writing means for applying an electrostatic charge from the outside to a transparent insulator layer, and an erasing means for removing the electrostatic charge on the surface thereof, Disclosed is a handwritten liquid crystal board set which has a power source for generating a surface potential on the surface thereof and is capable of repeatedly writing / erasing an image on a screen and having high operability, performance and safety.
However, there is room for further improvement in the writing line on the display screen when writing with a writing member, the uniformity of the image when a stamp is pressed, and the feeling of writing. An object of the present invention is to solve this problem, and to provide a liquid crystal board which has uniform writing lines and images on the display screen and has excellent writing feeling.

[0007]

[Means for Solving the Problems] The present inventors diligently studied a liquid crystal board in order to solve the above problems. As a result, they have found that the purpose can be achieved by providing a cushion material on the liquid crystal board, and have completed the present invention.

The liquid crystal display board of the present invention has the following constitution. (1) In a liquid crystal display board having a liquid crystal dispersed polymer layer in which liquid crystal is finely dispersed in a polymer matrix, a conductive layer, and a display screen capable of recording by external charging,
A liquid crystal board, wherein a cushion material layer is provided on the opposite side of the display screen. (2) The liquid crystal board according to item (1), which is formed by sequentially laminating a cushion material layer, a conductive layer, a liquid crystal dispersed polymer layer in which liquid crystal is finely dispersed in a polymer matrix, and a transparent insulator layer. (3) Cushion material layer, conductive layer, transparent high electric resistance layer,
A liquid crystal-dispersed polymer layer in which liquid crystal is finely dispersed in a polymer matrix and a transparent insulator layer are sequentially laminated (1).
The liquid crystal board according to item. (4) The liquid crystal board according to item (1), wherein a cushion material layer, a base material, a conductive layer, a liquid crystal dispersed polymer layer in which liquid crystal is finely dispersed in a polymer matrix, and a transparent insulator layer are sequentially laminated. (5) The liquid crystal according to item (1), which is formed by sequentially laminating a cushion material layer, a base material, a conductive layer, a transparent electric resistance layer, a liquid crystal dispersed polymer layer in which a liquid crystal is finely dispersed in a polymer matrix, and a transparent insulator layer. board. (6) The liquid crystal board according to item (1), which is formed by sequentially laminating a substrate, a cushion material layer, a base material, a conductive layer, a liquid crystal dispersed polymer layer in which liquid crystal is finely dispersed in a polymer matrix, and a transparent insulator layer. (7) Substrate, cushion material layer, base material, conductive layer, transparent high electrical resistance layer, liquid crystal dispersed polymer layer in which liquid crystal is finely dispersed in polymer matrix, and transparent insulator layer are laminated in this order (1) LCD board described.

The cushioning material of the liquid crystal board of the present invention includes processed sheets of natural rubber, synthetic rubber, etc., sponges such as polyethylene foam, polyurethane foam, resin foams such as expanded polystyrene, paper, pulp mold cushioning material, The material is not limited to those described above as long as it is a cloth, a non-woven cloth, or the like and has appropriate thickness and elasticity. The thickness of the cushion material layer is not particularly limited, but is usually 1 to 10 mm. The cushion material layer is provided at a position where the cushion material layer is provided instead of the base material on the opposite side of the display screen of a so-called liquid crystal sheet (LC sheet) including a conductive layer, a liquid crystal dispersed polymer layer, and the like.
A cushion material layer may be provided on the outside of the base material of the C sheet.

The conductive layer of the liquid crystal board of the present invention may be transparent or opaque and has a surface resistance of 10 ⁷ Ω.
/ □ Any layer having the following values may be used. Substantially, a glass, polyester, plastic film such as polyimide is used as a base material, and its surface is made of aluminum, titanium, chromium, tin, rhodium, gold, stainless steel, titanium nitride, nickel-chromium, aluminum-chromium or indium tin oxide. Made conductive.

The substrate of the present invention is a substrate for holding a conductive layer, and is a paper, cloth, non-woven fabric, polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene, polyvinyl chloride, polysulfone, polyphenylene oxide, ionomer, polyimide. , Plastic films such as polycarbonate. If the conductive layer itself is rigid, it is not necessary.

The substrate of the present invention is a substrate for holding a liquid crystal board and a cushioning material, and vinyl resins such as chlorinated polyethylene, polypropylene, polystyrene and acrylic resin, vinylidene chloride resin, polyvinyl acetal resin, cellulose resin, ionomer, Hard plastic plate such as polyamide, polycarbonate, polyphenylene oxide, polysulfone, fluororesin, silicon resin, chlorosulfonated polyethylene, polyester, epoxy resin, glass, metal plate, wood plate, etc. integrated with the frame of the liquid crystal board set itself. By doing so, a simple liquid crystal board can be obtained.

The conductive member means an air temperature of 23 ° C. and a relative humidity of 50.
%, Any conductive material having a volume resistivity of 10 ¹² Ω · cm or less, conductive paper, cloth, non-woven fabric, conductive plastics such as rubber and sponge, conductive materials such as polypyrrole, polythiophene, polyaniline, etc. Polymers, metals, alloys, metal oxides and the like can be used. The conductive member is connected to the conductive layer and serves as a conductive wire when a character or a figure is drawn on the board screen by using the writing member and when the displayed image is erased by the erasing member.

The liquid crystal dispersed polymer layer of the liquid crystal board of the present invention has a temperature of 2 in which liquid crystal is finely dispersed in a polymer matrix.
Volume resistivity is 10 ¹³ Ω at 0 ° C and 90% relative humidity.
-It is preferably at least cm. The liquid crystal dispersed polymer layer is
It is preferable that the liquid crystal is dispersed in the polymer matrix in the form of independent droplets, and the polymer constituting the liquid crystal dispersed polymer layer may be a polymer having a crosslinked structure. As a method for dispersing the liquid crystal, a polymer-liquid crystal common solvent evaporation phase separation method (common solvent casting method), a polymerization phase separation method in which a polymer precursor is polymerized from a liquid crystal-polymer precursor mixture by light or heat, a liquid crystal There are a melt-cooling phase separation method of cooling a polymer from a heated and molten state, a method of microcapsulating a liquid crystal and dispersing it in a polymer matrix, and the like can be appropriately used.

The polymer that can be used in the liquid crystal dispersed polymer layer may be any polymer that is not easily miscible with the liquid crystal, for example, vinyl resin such as chlorinated polyethylene, polypropylene, polystyrene, acrylic resin, vinylidene chloride resin, polyvinyl formal, polyvinyl. Acetal,
Polyvinyl acetal resin such as polyvinyl butyral, cellulose resin, ionomer, polyamide, polycarbonate, polyphenylene oxide, polysulfone, fluororesin, silicon resin, butadiene / styrene rubber, chlorosulfonated polyethylene, polyester,
Examples include epoxy resin. A polymer obtained by a crosslinking reaction is preferable. For example, the cross-linking agent is a di- and polyisocyanate compound, and as the compound capable of reacting with the cross-linking agent, there are polyvinyl acetal, epoxy resin, carboxyl group-containing acrylic resin, polyester resin, fluororesin, etc., and cross-linked polymers obtained by reacting these. Is. The crosslinked polymer is a mixture of the above components,
After adding a solvent as needed, dry heating (20 to 100
℃).

The liquid crystal used in the liquid crystal dispersed polymer layer is preferably a nematic liquid crystal. The liquid crystal phase has a temperature range of −10 ° C. to 100 ° C. for practical use as a liquid crystal board,
Moreover, in order to display the recorded image clearly, the birefringence Δn
Is preferably 0.2 or more. The volume resistivity of the liquid crystal dispersed polymer layer of the liquid crystal board is 90 ° C at a temperature of 20 ° C.
% (Hereinafter abbreviated as 90% RH) of 10 ¹³ Ω · cm or more, the contour of the recorded image is clear even in an environment of temperature of 20 ° C. and 90% RH, and the memory property, erasability, durability, etc. Is improved. The reason is that the applied electrostatic charge is not easily moved and attenuated and thus is held for a long time, and the contour of the recorded image is not blurred even after a lapse of time and is kept clear. Further, since the applied electrostatic charge is less likely to move and attenuate even at the top and bottom of the board screen, the erasability is improved. However, if the volume resistivity is less than 10 ¹³ Ω · cm,
The applied electrostatic charge moves on the plane of the board screen and above and below,
Since the static charge is easily decayed, the static charge disappears and decays over time, and the static charge becomes unbalanced on the plane of the board screen and on the upper and lower sides of the board screen. As a result, the contour of the recorded image, the memory property, and the erasability are deteriorated. When a dichroic dye is added to the liquid crystal dispersed polymer layer together with liquid crystal, the color tone of the board screen can be changed, or the conductive layer and the substrate can be made transparent, and paper, plastic film, etc. can be provided as a colored layer on the outside of the substrate. When used, board colors and image colors of any color can be obtained and clear contrast can be obtained.

A transparent polymer having a high electric resistance can be used for the transparent insulator layer of the liquid crystal board of the present invention. The volume resistivity is preferably 10 ¹³ Ω · cm at a temperature of 20 ° C. and 90% RH.
With the above, for example, polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene, polyvinyl chloride, polysulfone, polyphenylene oxide, ionomer, polycarbonate, nylon and fluororesin films such as adhesive, laminated with an adhesive, It can be obtained by applying a solution of a material having the above physical properties and drying it. If a transparent insulator layer having a volume resistivity of less than 10 ¹³ Ω · cm at a temperature of 20 ° C. and a relative humidity of 90% is used, a problem in performance occurs due to the same reason as that of the liquid crystal dispersion polymer layer, and a practical liquid crystal is used. Not a board.

The transparent high electric resistance layer of the liquid crystal board of the present invention is provided between the conductive layer and the liquid crystal dispersed polymer layer.
Its volume resistivity is 10 at 90% RH at 20 ° C.
¹³ Ω · cm or more. This layer more reliably prevents migration and attenuation of the electrostatic charge applied to the board surface, and thus improves performance such as sharpness of the contour of the recorded image, memory property and erasability. If a volume resistivity of less than 10 ¹³ Ω · cm at a temperature of 20 ° C. and 90% RH is used, a problem in terms of performance is caused for the same reason as that of the liquid crystal dispersion polymer layer, which is not practical. The transparent high electric resistance layer can be obtained by coating, or by laminating a high electric resistance film with an adhesive or an adhesive. The thickness of the transparent high electric resistance layer is preferably in the range of 0.4 to 10 μm.

In the means for displaying a recorded image of the liquid crystal board of the present invention, one terminal of a power source capable of generating a potential of 50 V or more between the surface of the liquid crystal board and the conductive layer is electrically connected to the conductive layer of the liquid crystal board. After connecting, the other terminal is electrically connected to the writing member. A recorded image can be obtained by bringing the writing member into contact with the board screen of the liquid crystal board. When a surface potential of 50 volts or more is generated on the board screen, the liquid crystal in the liquid crystal dispersed polymer layer is oriented by an electrostatic field and becomes transparent, and a transparent and high-contrast recorded image is obtained on the cloudy board screen. When the surface potential is less than 50 volts, the liquid crystal is not sufficiently oriented due to insufficient alignment, and thus the contrast of the recorded image is low.

The recorded image erasing means of the liquid crystal board of the present invention electrically connects the conductive layer of the liquid crystal board and the erasing member. By bringing the erasing member into contact with the recorded image (substantially the surface of the transparent insulator layer) on the board screen of the liquid crystal board, the recorded image and the conductive layer have the same potential, and the static charge of the recorded image is easily removed. To delete the recorded image.

A member for writing used in the liquid crystal board of the present invention,
Examples of the erasing member include metals and alloys such as copper, iron, aluminum, tin, palladium, gold, silver, brass and stainless steel, oxides of metals such as tin, indium, silver, zinc and manganese, polypyrrole, polythiophene and polyaniline. Conductive polymers such as, and conductive materials such as graphite and carbon fiber.

Depending on the characteristics of the material, these materials may be directly processed into wire (conductor wire), contact (terminal), conductive fiber, plastic film, fiber, non-woven fabric, rubber, sponge, glass, etc. The surface of the base material is processed to form conductive film, conductive fiber, conductive rubber, conductive sponge, conductive glass, etc., or processed into fine particles or fibers and then kneaded into plastic, rubber, etc. Can be made into a form such as a conductive plastic, a conductive rubber, or a conductive porous body, and these can be used as a writing member or an erasing member by combining them according to the purpose of use or further processing. it can.

When the writing member and / or the erasing member is used as a stamp using a conductive elastic body or the like, it is possible to easily display an arbitrary character or figure only by bringing the stamp into contact with the board screen. You can Furthermore,
By using the conductive fiber or the conductive elastic body in a writing brush type, the handwriting of the recorded image can be made thicker or thinner than if it were drawn with a writing brush.

The display means of the liquid crystal board of the present invention, the writing member used for the erasing means, and the erasing member do not need to be connected by a conductive wire. For example, even if an appropriate portion of the display means is touched with the hand and the other hand or the writing member is brought into contact with the board screen, a display can be obtained in the same manner as the display means. If the user touches such a portion and touches the recorded image portion of the board screen with the other hand or holding the erasing member, erasing can be performed in the same manner as the erasing means. The liquid crystal board is simple and less prone to failure without the risk of wire entanglement or disconnection even after repeated display and deletion.

More specifically, the display means comprises a connection line between the other terminal of the power supply and the tentacle surface electrode of the writing switch, and the erasing means comprises the connection line between one terminal of the power supply and the conductive layer. , The connecting line between the terminal and the tentacle surface electrode of the erasing switch, and the erasing switch and the writing switch are interlocked. For example, the b contact of the writing switch and the a contact of the erasing switch are connected in series to one terminal of the power source, and the a contact of the writing switch and the b contact of the erasing switch are connected in series to the other terminal of the power source. I will do it. That is, the writing switch is pressed with one hand to contact the surface electrode, and the other hand or the other hand holds the writing member and contacts the board screen to obtain a recorded image. To be Further, the recorded image can be erased by pressing the erasing switch with one hand to contact the surface electrode and holding the erasing member with the other hand itself or the other hand to contact the recorded image on the board screen.

Further, by using the liquid crystal board as shown in FIGS. 3 and 4 in which wirings such as the power source and the switch are not provided at all, one hand touches the conductive member 42,
The writing member 44 having a built-in power supply for generating a surface potential of 50 V or more on the surface of the liquid crystal board is brought into contact with the board screen 18 to display images such as characters and figures. When erasing this image, the recorded image can be erased by touching the conductive member 42 with one hand and holding the erasing member with the other hand to contact the recorded image on the board screen. It is also possible to manually erase without holding the erasing member.

[0027]

The recorded image is displayed and erased on the principle that the liquid crystal dispersed polymer layer of the liquid crystal board of the present invention becomes transparent and opaque depending on the presence or absence of an electrostatic field. That is, when no electrostatic field is applied, light scattering occurs due to the difference in refractive index between the polymer and the liquid crystal, and the liquid crystal board is cloudy and opaque.
When characters or figures are drawn on the board screen using a pen-type or stamp-type writing member, an electric field is applied to the liquid crystal-dispersed polymer layer through the transparent insulator layer, and the liquid crystal is oriented in the direction of the electric field. The refractive index of the liquid crystal is almost the same, as a result, light scattering does not occur and it becomes transparent,
A contrast occurs between the board screen and the drawn characters or figures, and the display state is set. Conventionally, these characters and figures were not always drawn uniformly, but by providing a cushioning material, the tip of the pen-type or stamp-type writing member can be made even and sure when drawing characters and figures on the board screen. Since the board screen is pressed, the outline of the writing line becomes clear, and uniform characters and figures can be drawn.
Further, the elasticity of the cushioning material eliminates the hard feeling of the board screen, and therefore a soft writing feeling can be obtained.

[0028]

Embodiments of the present invention will be described with reference to the drawings. In the drawings, the same numbers are given to the same members and parts. 1 to 4
FIG. 1 is a schematic view of an embodiment of a liquid crystal board of the present invention.

Example 1 will be described with reference to FIG. (A) Preparation of liquid crystal sheet: On a conductive layer 3 of an aluminum vapor deposition film (manufactured by Toyo Metallizing Co., Ltd .: "# 125 Metalmy TS") in which a base material 2 is a polyethylene terephthalate film and a conductive layer 3 is a vapor deposition aluminum layer, As the transparent high electric resistance layer 8, a solution having the following composition was applied, dried and cured so that the dry film thickness was 3 μm. Polyvinyl formal (manufactured by Denki Kagaku Kogyo Co., Ltd .: “Denka Formal # 20”) 10% tetrahydrofuran solution 9.0 g Polyisocyanate (manufactured by Takeda Pharmaceutical Co., Ltd .: “Takenate D110N”) 0.4 g The above transparent high electric resistance layer 8 Polymer matrix 4 on top
As the liquid crystal dispersed polymer layer 6 in which the liquid crystal droplets 5 are finely dispersed,
A solution having the following composition was applied, dried, and cured so that the dry film thickness was 7 μm. Polyvinyl formal (manufactured by Chisso Corporation: “Vinylec K-624”) 10% tetrahydrofuran solution 4.2 g Polyisocyanate (manufactured by Takeda Pharmaceutical Co., Ltd .: “Takenate D110N”) 0.56 g Nematic liquid crystal (manufactured by MERCK: “E44”) 0.36 g Furthermore, a transparent insulator layer 7 made of a polyethylene terephthalate film (manufactured by Teijin Ltd .: "Tetron Film F") having a thickness of 9 μm was laminated on the liquid crystal dispersed polymer layer 6 by using an adhesive, and this example was used. A liquid crystal sheet of was prepared. Further, for the liquid crystal dispersed polymer layer 6 whose humidity was adjusted to 90% RH at an air temperature of 20 ° C., a direct current power source (“PR-630” manufactured by Trio Co., Ltd.) and an electrometer (“TR8651” manufactured by Takeda Riken Kogyo Co., Ltd.) were used. ), The insulation resistance measurement sample box (manufactured by Advantest Corporation: “TR42”) was used to measure the volume resistivity, and the following values were shown. Transparent high electric resistance layer 1.5 × 10 ¹⁴ Ω · cm Liquid crystal dispersed polymer layer 7.4 × 10 ¹⁴ Ω · cm

(B) Preparation of liquid crystal board: A cushion material 41 made of polyurethane foam having a thickness of 2 mm was attached to the outside of the base material 2 of the liquid crystal sheet by using an adhesive. The following connections were made. 1) A writing switch 30 is provided, and a surface electrode 33 thereof is provided.
The lead wire 12 is connected to (made of phosphor bronze), the erasing switch 31 is arranged, and the lead wire 16 is connected to the surface electrode 34 thereof. 2) A conductor 22, between the terminal 11 of the power source 10 and the conductor 12.
Connect the conductor and contact in the order of the a contact 23 of the writing switch, the conductor 24, and the b contact 25 of the erase switch.
The conductor 26, the b contact 27 of the writing switch, the conductor 28, and the a contact 29 of the erasing switch are connected between the conductor 5 and the conductor 16 in this order. 3) The writing switch 30 is a contact point 2 of the writing switch.
3 and the writing contact b contact 27 to form an interlock. The erasing switch 31 includes an erasing switch b contact 25 and an erasing switch a contact 2.
In conjunction with 9, an interlock is formed. Also, normally, the b contact 25 of the erasing switch and the b contact of the writing switch are
The contact 27 is connected, and the a-contact 23 of the writing switch and the a-contact 29 of the erasing switch are correspondingly separated from each other. 4) Furthermore, 1 is provided between the terminal 14 of the power source 10 and the lead wire 15.
An electrical resistance 19 of 0 MΩ, an electrical resistance 20 of 10 MΩ between the conducting wire 15 and the conductive layer 3, and an electrical resistance 21 of 10 MΩ between the erasing switch a contact 29 and the conducting wire 16 were respectively connected. Cushion material 41 with LC sheet attached
The substrate 43 was attached to the above, and the above wiring was housed therein to manufacture a liquid crystal board (FIG. 2).

(C) Writing operation: While pushing the writing switch 30 with the left hand, the writing member 13 is held with the right hand (contacting the surface electrode 33 of the writing switch) and a drawing line such as characters and figures is drawn on the board screen 18. A recorded image 32 was obtained. The strokes were uniform and clear, and the writing feel was soft and easy to write. (D) Erase operation: While pressing the erase switch 31 with the left hand (contacting the surface electrode 34 of the erase switch), the image is erased by tracing the recorded image 32 with the erase member 17 with the right hand. In this writing operation and erasing operation, the human body naturally plays a role in connecting the surface electrode 33 of the writing switch 30 and the writing member 13 and connecting the surface electrode 34 of the erasing switch 31 and the erasing member 17. . In this embodiment, the electric resistance and the interlock are combined to provide safety, and a double electric shock prevention mechanism is provided. In this way, a liquid crystal board was obtained that not only can be repeatedly displayed and erased, but also with high safety, in which the lines drawn on the screen are uniform and clear, with a soft writing feeling and easy writing.

Comparative Example 1 A liquid crystal board was produced in the same manner as in Example except that the cushion material 41 was not used. The feeling of writing is harder than that of the example, and the drawing line of characters, figures, etc. is less uniform than that of the example 1.

Example 2 This will be described with reference to FIGS. A cushion material 41 made of polyurethane foam having a thickness of 2 mm was attached to the surface of the base material 2 of the liquid crystal sheet of Example 1 using an adhesive. A conductive non-woven fabric is attached as the conductive member 42 as an edge of the board screen 18 made of the transparent insulator layer 7 and, at the same time, is brought into contact with the conductive layer 3 and attached to the cushion material 41. This was attached to a substrate 43 in which the board frame and the substrate were integrated to produce a liquid crystal board. Touch the left hand to the conductive member 42,
A pen 44 with a built-in power source and a charged nib was held in the right hand and a letter was written on the board screen. The strokes were uniform and clear, and had a soft writing feel and was easy to write. Erase member 1
7 was held in the right hand and the left hand was brought into contact with the conductive member 42 to erase the written characters.

[0034]

EFFECTS OF THE INVENTION It is possible to provide a liquid crystal board in which lines drawn on the screen are uniform and clear lines and writing lines can be drawn, and the writing feeling is soft and easy to write. Of course, not only can the display and erasing be repeated easily but also it is highly safe and can be used easily.

[Brief description of drawings]

FIG. 1 is a schematic view of a liquid crystal board of the present invention in which a power source, a switch and the like are wired.

FIG. 2 is an actual perspective view of the liquid crystal board shown in FIG.

FIG. 3 is an actual perspective view of a liquid crystal board of the present invention in which a power source, a switch and the like have no wiring.

4 is a view showing a cross section taken along the line AA of the liquid crystal board of FIG.

[Explanation of symbols]

 2 Base Material 3 Conductive Layer 4 Polymer Matrix 5 Liquid Crystal Drop 6 Liquid Crystal Dispersed Polymer Layer 7 Transparent Insulator Layer 8 Transparent High Electric Resistance Layer 10 Power Supply 11 Terminal 12 Conductor Wire 13 Writing Material (Pen Type) 13 Writing Material (Stamp Type) 14 terminals 15 conducting wire 16 conducting wire 17 erasing member 18 board screen 19 electrical resistance 20 electrical resistance 22 conducting wire 23 writing switch a contact 24 conducting wire 25 erasing switch b contact 26 conducting wire 27 writing switch b contact 28 conducting wire 29 erasing switch a Contact point 30 Writing switch 31 Erasing switch 32 Recorded image 33 Tentacle surface electrode of writing switch 34 Tentacle surface electrode of erasing switch 41 Cushion material 42 Conductive member 43 Substrate (or frame) 44 Special pen (pen with built-in power supply)

Claims (7)

[Claims] 1. A liquid crystal display board having a liquid crystal-dispersed polymer layer in which liquid crystal is finely dispersed in a polymer matrix, a conductive layer, and a display screen capable of recording by external charging, and a cushion material layer provided on the opposite side of the display screen. Liquid crystal board that is characterized. 2. The liquid crystal board according to claim 1, wherein a cushion material layer, a conductive layer, a liquid crystal dispersion polymer layer in which liquid crystal is finely dispersed in a polymer matrix, and a transparent insulator layer are sequentially laminated. 3. The liquid crystal board according to claim 1, wherein a cushion material layer, a conductive layer, a transparent high electric resistance layer, a liquid crystal dispersed polymer layer in which liquid crystal is finely dispersed in a polymer matrix, and a transparent insulator layer are sequentially laminated. . 4. The liquid crystal board according to claim 1, wherein a cushion material layer, a base material, a conductive layer, a liquid crystal dispersion polymer layer in which liquid crystal is finely dispersed in a polymer matrix, and a transparent insulator layer are sequentially laminated. 5. A cushion material layer, a base material, a conductive layer, a transparent electric resistance layer, a liquid crystal dispersed polymer layer in which liquid crystal is finely dispersed in a polymer matrix, and a transparent insulator layer are sequentially laminated. LCD board. 6. A substrate, a cushion material layer, a base material, a conductive layer,
The liquid crystal board according to claim 1, wherein a liquid crystal-dispersed polymer layer in which liquid crystal is finely dispersed in a polymer matrix and a transparent insulator layer are sequentially laminated. 7. A substrate, a cushion material layer, a base material, a conductive layer,
The liquid crystal board according to claim 1, wherein a transparent high electric resistance layer, a liquid crystal dispersed polymer layer in which liquid crystal is finely dispersed in a polymer matrix, and a transparent insulator layer are sequentially laminated.