JPS63278895A - Card having display function and memory capacity - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a card that has a memory capacity on its own, such as a bank CD card, an In card for confidentiality, a pre-sale card for train tickets, etc. There are suggestions.

[Conventional technology]

For pre-release cards such as bank CD cards and train tickets, magnetic tape is pasted onto a paper or resin board, and the magnetic tape is used to store information such as account numbers and balances. It is being said. However, the storage capacity of magnetic tape is very small and can only store numbers and symbols of several digits.

Further, in this case, the contents stored on the tape could not be arbitrarily rewritten.

EE was devised to solve such problems.
There are cards (so-called IC cards) equipped with integrated circuits having FROM (electrically rewritable ROM) memory.

C Problems with these cards] In other words, IC cards were devised for the purpose of increasing storage capacity;
It was also possible to arbitrarily rewrite a large amount of stored content using integrated circuits. However, even if not all of the information stored in the card, even the minimum information that the card owner wants to know can only be learned by using a terminal device connected to a large computer and displaying it on the display device of the terminal device. It was something that could be done.

Therefore, the ability to display the memory contents on the card was required.

Therefore, it was necessary to form a display section and an information storage section on the same card.

As a part for performing this display, a liquid crystal display is most commonly used due to its display ability and power consumption.

Furthermore, as the part that performs storage, the aforementioned EEFROM is generally used due to its storage capacity, and creating these on the same card increases the number of steps.

Many technical problems arose, including a complicated card structure.

[Means for trying to solve problems]

The present invention solves these conventional problems, and as claimed in the claims, a pair of substrates, an electrode on the substrate, a liquid crystal arrangement part on the electrode, and a liquid crystal disposed between the pair of substrates are filled. In addition, in a card made of a liquid crystal material having ferroelectric properties and having a display function and a memory capacity, the electrodes have a matrix configuration or a shape of one figure, character, symbol, etc., so that characters, nine figures, symbols, etc. can be displayed. a liquid crystal display area,
By applying energy such as electricity, heat, or light to the liquid crystal layer from outside the card, external information is used as a signal to create an information storage area that can be written, erased, and rewritten using a ferroelectric liquid crystal material. The invention comprises a card having a display function and a memory ability, which is characterized by having a polarizing means in at least a portion of the display area or the storage area.

In other words, the display area and memory area are constructed using the same ferroelectric liquid crystal, reducing the number of manufacturing steps.

Memory using this ferroelectric liquid crystal is
A patent and application was filed by the same inventor as the present invention.
There is an optical disk device j using ri#l dielectric liquid crystal, and the reading, rewriting, and erasing of stored information is the same.

This memorization method is based on the first state in which the liquid crystal molecules are tilted at an angle of θ with respect to the layer normal of the smectic layer, and the liquid crystal molecules in this state are On the other hand, by applying electrical, thermal, or optical energy from the outside, the layer is changed to a second state at an angle of 10 with respect to the normal line of the layer.

At this time, the difference between the states is determined by detecting an optical change caused by the difference between the first state and the second state using an external detection means.

In other words, the first state is 0. The second state is set to 1 and information is stored as a signal.

A method for causing liquid crystal molecules to assume the first state and the second state will be explained with reference to a cross-sectional view of the storage area of this card shown in FIG.

The first method is to create this state by making the distance □ between the upper and lower substrates (1) and (7) sufficiently shorter than the helical pitch of the ferroelectric liquid crystal (4). It is said to be 5 spTC, and it forces the liquid crystal molecules to assume two states by force from the interface (substrate).

Next, as a second method, the upper and lower liquid crystal alignment parts (3).

(5) There is a method of attracting liquid crystal molecules by utilizing the difference in polarity caused by changing the materials used to express this state, and a third method is that of the liquid crystal alignment part (
3) and (5) are formed into a laminated structure, and an electric field generated by storing charge in that part is applied to the liquid crystal (4), thereby causing the first state and the second state to be expressed. .

The present invention will be explained below with reference to Examples.

Embodiment FIG. 1A shows a card having a display function and a storage capacity using the ferroelectric liquid crystal memory of the present invention.

(B) shows its A-A' cross-sectional view.

Further, FIG. 3 shows a system using the card of the present invention.

The memory card consists of a pair of opposing boards (4) and a board (10).
). Furthermore, a pair of transparent electrodes (5) and (9) are provided inside the pair. Furthermore, alignment treatment parts (6) and (8) are formed on the pair of electrodes.

Further, FLC (7) is filled between the substrates.

The periphery of this memory card is sealed (10) to prevent the PLC from coming into contact with the atmosphere.A pair of electrodes (5) and (9) extend from a pair of electrodes on the outer periphery of this memory card. (5') and (9').

These external contact electrodes (5°) and (9°) are connected to the lead terminals derived from the signal source (13) when writing and erasing memory (full-scale erasing), and a predetermined voltage is applied to them. will be carried out.

In this way, the system (101) is used to "write" information to the memory area whose entire surface is "0".

In other words, a light beam, especially infrared rays, is sent from (19) to the PLC arrayed in one direction over the entire surface, through a mirror (1B) and a half mirror (17), and then through a condensing optical system, a position correction system (22), and a predetermined beam. At this time, upper and lower electrodes (5) perform writing by irradiating light to an address and shifting the state of liquid crystal molecules at a predetermined address from the initial state.

If a voltage lower than the inversion threshold voltage of the liquid crystal was applied during (9), information could be written more quickly and accurately. Further, the light passes through a mirror (16) and reaches a photosensor (14). Monitor whether information is being written here.

As a method for "reading" information, a semiconductor laser (2
1) The light beam emitted from the polarizing means (20).

The laser beam enters through a half mirror (17), a condensing optical system, a position correction (auto tracking device) (22), and a polarizing means (20) of the memory card. Furthermore, the light transmitted through the storage area (3) of this memory card reaches the light receiving sensor (14) via a polarizing means (15) and a mirror (16). This optical sensor (14)
, the information is read by detecting whether the laser beam is transmitted or not.

In this case, mirror (1
6), (17), (18) and optical system (22)
was moved relatively parallel to the card (1) to write or read information at a predetermined address.

That is, the card (1) may be moved mechanically, the mirror or optical system may be moved, or both may be moved simultaneously.

This memory card will be described in more detail below.

In this example, a plastic substrate or a Corning 7059 glass substrate (4), (10) was used as the substrate.

ITO (indium tin oxide), which is a transparent conductive film, is formed on this substrate by vacuum evaporation. An asymmetrical alignment film (6) is placed inside this pair of electrodes (5) and (9).
) and (8) are provided, and a spacer (not shown) is interposed to form a liquid crystal cell with a substrate spacing of 2 μm.

FLC (7) is sandwiched between these. For alignment treatment, 0.1 PAN (polyacrylonitrile) and PVA (polyvinyl alcohol) were applied on the counter electrode (5).
It was provided by a spin method to a thickness of μ-lin, and then subjected to a known rubbing treatment. As an example of the rubbing process, a nylon cloth is rotated at 90 ORPM using a rubbing device, and the substrate is moved over the surface of the alignment film at a speed of 2 m/min.
) was formed. Moreover, an inorganic compound δ alignment film was formed on the other electrode (9) to form a liquid crystal alignment part (8) that was not subjected to rubbing treatment. A PLC such as a biphenyl chiral smectic liquid crystal was filled between the liquid crystal alignment parts (6) and (8). Other than this, BOBAMBC etc.
It can be filled with LC or FLC which is a blend of multiple liquid crystals. An example of the threshold characteristic of this FLC is shown in Fig. 4. In the same figure, by adding ±5V, the curve (24),
(25) could be obtained.

In other words, by inverting the liquid crystal molecules, light can be transmitted,
It has been found that it is possible to achieve non-transmission and at the same time obtain hysteresis, which exhibits a memory effect.

In FIG. 4, the vertical axis is the light transmittance.

In addition, as the display area section (2) of this card (1),
It has the same structure as the storage area described above.

However, in this example, a pair of electrodes (5).

(9) has a matrix configuration, and each character, figure, or symbol can be displayed using dots. Also, an IC for this purpose is provided on the card.

That is, the storage area section (3) and the display area section (2) of the card.
), all other structures are the same except for the shape of the electrodes, so it is possible to create a card that has both display and storage capabilities in the process of creating a conventional liquid crystal display device. It is something.

Further, the polarizing means (15) and (20) are attached to both sides of the card, so that no polarizing means is required on the optical reading means side.

Furthermore, since this polarizing means also serves as a polarizing plate for the display area, it can be manufactured at a lower cost.

Now, as an example of how this display memory card is used, for example, when using it as a CD card for use at a bank, etc., the card owner goes to the bank, and the CD terminal connected to the computer is connected to the card's electrode (5'). , (9
°), and extracts information such as the card owner, account number, past transaction details, etc. from the storage area of the card using optical reading means, and at the same time reads new information using optical means. The necessary information is written on the card display.

The liquid crystal used in this display is a liquid crystal that exhibits ferroelectricity (chiral smectic C liquid crystal), so when it is sealed in a parallel plate with a helical pitch or less, it has a stable biaxial position, and due to the electric field, One of the two directions can be selected. Moreover, even if the electric field is removed, it remains fixed in a stable position, and by combining it with a polarizing plate, it is possible to leave a display (such as letters).

Therefore, when the card is taken out of the CD terminal, power is no longer supplied to the card, and the memory remains in the ferroelectric liquid crystal storage area and ferroelectric display area.

In this way, the user can view the contents of the memory anytime and anywhere.

Although we have only shown how to use a bank CD card here, it is quite possible to use it for other purposes.

In this embodiment, the card of the present invention has a display area (2
) and storage area section (3) are both shown in a transmissive format, but in addition to this embodiment, a reflective format may also be used without hindering the effects of the present invention.

In this case, since the laser beam is reflected at the electrode portion of the card, one of the substrates can be made of metal, and the card of the present invention can be manufactured at a lower cost.

Furthermore, when the card of the present invention is not provided with external electrode terminals, the memory of the card can be read without using any electrical connections, and in that case the storage section works as a ROM.

In addition, dichroic dyes are added to FLC, and guest-
It is also possible to store and display information in the host mode, and in this case, the device is characterized in that it only requires one or zero polarizing means.

〔effect〕

By inserting a display device using ferroelectric liquid crystal and a storage area inside the card, the card itself has a memory function compared to conventional magnetic card type cards, and the memory content of the card. It is now possible to check some or all of the information at any time through a display device without the need for a specific terminal device.

Also, since power is only needed when rewriting, there is no longer a need for a power supply inside the card.

In addition, since the storage area section and the display area section were able to be realized with the same structure, cards with two functions can be created in the same process as conventional liquid crystal display devices, and are inexpensive. It has become possible to realize a simple memory card that can be mass-produced.

Although the storage area of the present invention has the same structure as the display area, the stored information is not exposed to the outside and cannot be seen unless it is read by a dedicated machine!
It can be used for D cards etc. In addition, since the display in this display area does not require a power source such as a battery or a control mechanism such as a CPU, the machine becomes simple and can be produced in large quantities at low cost. The credibility of the stored information is improved by the display means. In addition, LCD displays cannot be rewritten without applying voltage and heating, and are stable without data being removed even with changes in temperature that occur in daily life. , it can be reused by changing it.

Furthermore, since the polarizing means attached to the card serves as the polarizing means for the display area and the storage area, it can be manufactured at a lower cost.

[Brief explanation of drawings]

FIG. 1 shows a plan view and a sectional view of a card according to the invention. FIG. 2 shows the states of liquid crystal molecules. FIG. 3 shows the system of the card of the present invention. FIG. 4 shows the characteristics of transmitted light in the storage area of the card of the present invention. 1...Card 2...Display area section 3...Storage area section 6.8...Liquid crystal alignment section 7... ····liquid crystal

Claims (1)

[Claims] 1. A display function and a memory capacity made of a pair of substrates, an electrode on the substrate, a liquid crystal alignment section on the electrode, and a liquid crystal material having ferroelectricity filled between the pair of substrates. The card has a liquid crystal display area for displaying characters, figures, symbols, etc., and a liquid crystal display area for displaying characters, figures, symbols, etc., and a card for transmitting energy such as electricity, heat, or light, by having the electrodes in a matrix configuration or in the shape of figures, letters, symbols, etc. An information storage area that can be written, erased, and rewritable by applying external information to the liquid crystal layer from outside the card as a signal is realized using a ferroelectric liquid crystal material, and at least one of the display area or the storage area
A card having a display function and a memory ability, characterized by having a polarizing means in a portion thereof. 2. In claim 1, the liquid crystal alignment unit limits the states that the liquid crystal molecules can take to only a certain plurality of states, and as long as energy such as electricity, heat, or light is not supplied from the outside. A card having a display function and a memory ability, which is characterized by having the ability to maintain a specific state.