JP2003315760A - Ic card loaded with display function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an IC card loaded with a display function wherein it is not needed to incorporate a cell necessary for continuation of display therein and to control high voltage for control by building a film liquid crystal display medium on the IC card, making it possible to display dynamic information by control from the loaded IC and providing a means for easily cancelling display while securing continuity of display. <P>SOLUTION: The IC card loaded with the display function in which a film liquid crystal element is built is characterized in that display of contents of the card by communication with an external instrument and erasure of display contents by application of stress of bending deformation or the like are made possible. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC card equipped with means for displaying variable information by a film liquid crystal, and can be suitably used for a prepaid card, a credit card, a point card, a boarding pass, a boarding pass, and an ID card. It is a thing.

[0002]

2. Description of the Related Art IC cards are often used for authentication and settlement purposes for ID cards, credit cards, point cards and the like. The IC card is formed by embedding a semiconductor chip in a plastic card, and is roughly classified into a contact type in which terminals are provided on the card surface and a non-contact type in which an antenna is built. Contact type and non-contact type IC cards are
Since both of them electrically communicate with the terminal (for example, authentication and rewriting of stored contents), various methods have been proposed as means for confirming recorded information during use or carrying. As a method of visualizing the card information, Japanese Patent Laid-Open No. Hei 5-
201130 (Oki Electric Industry Co., Ltd.) and Japanese Patent Laid-Open No. 5-2
As disclosed in 78332 (Ricoh Co., Ltd.), a method of recording a point number and a balance by providing a reversible thermosensitive recording layer on the surface of a card has been invented. Such thermal recording can be inexpensively provided on the card, and characters and the like can be recorded neatly, but on the other hand, performance such as poor repeatability printability and the fact that it must be passed through the terminal Get limited in terms of terms.

Therefore, many attempts have been made to provide a voltage-driven display element such as a liquid crystal on the card itself by using voltage control by an IC incorporated in the card. Such a card with a display function is being considered as a means for confirming personal information in which security is important and dynamic information such as balance display and accumulated point value. JP-A-63-16
171 (Kansai NEC Corporation) and Japanese Patent Laid-Open No. 63-116.
In 380 (NEC Electric Microcomputer System Co., Ltd.) and JP-A-63-176671 (Oki Electric Industry Co., Ltd.), an IC card in which a liquid crystal display element and a battery are mounted on a contact type IC card is used as a financial card or a credit card. It is shown for the purpose of using. Buttons for controlling the operation of the IC and a battery for driving are provided on the surface of the card so that a display according to the operation is performed. Further, in JP-A-11-120312 (Toppan Printing Co., Ltd.), a ferroelectric liquid crystal for an IC card is disclosed in
In 154215 (Shinko Denki Co., Ltd.), a ferroelectric liquid crystal display for a non-contact IC card is under study.

When the display element is introduced into these IC cards, it is required to make the display element thin and drive it at a low voltage.
When introducing a general-purpose film liquid crystal such as nematic liquid crystal or a ferroelectric liquid crystal film, an optical film such as a polarizing plate or a polarizing film is necessary in addition to the film cell, which is inconvenient in terms of medium thickness and price. There are many. Further, in the case of a low-voltage driven liquid crystal medium, it is generally difficult to obtain display sustainability, and therefore, it is necessary to incorporate a battery, while conversely, when a liquid crystal with a memory property having display sustainability is used, A high voltage is required when switching the display.

A polymer network liquid crystal display (PNLC; Polymer) is one that can be driven at a low voltage without requiring an optical film such as a polarizing film for displaying.
The Network Liquid Crystal) is known. Generally, polymer dispersed liquid crystal (PDL)
C; Polymer Dispersed Liquid
d Crystal) is a display medium composed of a polymer binder and a liquid crystal compound, like a liquid crystal called a liquid crystal,
A curable resin that serves as a binder is provided so as to form a mesh, but since the liquid crystal is continuously present in the medium, 3
It is possible to drive from the scattering state to the transparent state with a low voltage of about 5 V. However, the display obtained by driving at a low voltage can be displayed only while the voltage is being applied, and when the power is turned off, the original scattering state is restored in an extremely short time, making it impossible to read the information. .

On the other hand, in a display using a cholesteric liquid crystal having a bistable orientation state, when the spontaneous orientation of the liquid crystal layer is a planar orientation (hereinafter P orientation), a focal conic orientation (hereinafter F orientation) is generated by an applied voltage. Homeotropic alignment (hereinafter H-alignment) due to higher applied voltage
Has the state of. The P-orientation has a spontaneous multi-layer orientation of rod-shaped molecules, has an orientation in one direction in one layer, and twists the orientation direction slightly between adjacent layers to form a spiral structure as a whole. . In the P orientation, the period can be set to the order of the optical wavelength by selecting the material, and selective reflection can be provided in the visible region. Therefore, even when the cholesteric liquid crystal is used, an optical film such as a polarizing film is required. Since it does not, thinning is possible. Further, by applying an appropriate voltage, the alignment can be aligned in the vertical direction with respect to the electric field, and it can be changed to the F alignment state in which incident light is almost transmitted. Both the P-orientation state and the F-orientation state are stable states, and since the display has a memory property, a power source is not always required for sustaining the display. However, switching from the F orientation state to the P orientation state must go through the H orientation state (depending on the cell thickness).
Usually, a high voltage of about 30 to 60V is required.
Therefore, it is difficult to secure a liquid crystal display medium for an IC card, which has both thinness, low voltage driving, and continuous display.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a film liquid crystal display medium is built in an IC card, and dynamic information can be displayed under the control of an on-board IC. It is an object of the present invention to provide a display function-equipped IC card that does not require a built-in battery required for sustaining display or control of a high voltage for control by providing a means for canceling display.

[0008]

In order to achieve the above object in the present invention, first, in the invention of claim 1, in a display function IC card having a built-in film liquid crystal element, the contents of the card by communication with an external device And a display function can be erased by applying stress such as bending deformation.

According to a second aspect of the present invention, in the IC card with a display function according to the first aspect, the I-type display function is provided.
This is an IC card equipped with a display function characterized in that a cholesteric liquid crystal exhibiting bistability in a planar state and a focal conic state is used as a film liquid crystal element incorporated in a C card.

According to a third aspect of the present invention, in the IC card with a display function according to the first aspect, the film liquid crystal element is in a planar state when no voltage is applied, and is partially changed to a focal conic state by applying a voltage. This is an IC card equipped with a display function, which is characterized in that it is displayed as a display.

According to a fourth aspect of the invention, in the IC card having a display function according to the first aspect, a film liquid crystal element is provided on a circuit board embedded in the IC card. It is what

According to the invention of claim 5, a card is formed by laminating a transparent resin base material on the whole surface or a part of the circuit board provided with the film liquid crystal element so that the display content of the film liquid crystal element can be confirmed at least. An IC card with a display function, characterized by being molded into a shape.

According to a sixth aspect of the present invention, in the IC card with a display function according to the first aspect, an antenna coil provided on a circuit board embedded in the card converts an electromagnetic wave from the outside into electric power, and a film liquid crystal. An IC card equipped with a display function, which is used for driving an element.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, in order to solve the above-mentioned problems, a selective reflection state due to spontaneous alignment of liquid crystal and a state in which incident light is almost transmitted in order to align in a direction perpendicular to an electric field when a voltage is applied. By providing a cholesteric liquid crystal having bistability in a flexible film cell, a thin liquid crystal film that does not require an optical film such as a polarizing film is provided, and it is provided with an antenna coil on the circuit board built into the non-contact IC card. With LCD display function I
Use C card. The liquid crystal film is driven by an electromotive force generated by a built-in battery or an antenna coil and controlled by an IC chip built in the IC card. The displayed contents can be continuously displayed without requiring the application of a voltage. To erase the display, bend the card appropriately or apply a light pressure to the display with your finger, etc., causing collapse of the orientation of the cholesteric liquid crystal provided in the flexible film cell and induction of spontaneous orientation, It can be performed at the discretion of the user without applying a high voltage or using a special device. The antenna coil referred to in the present invention refers to a coil-shaped antenna, and may be made of either a conductor pattern or a conductor.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a view showing an embodiment of a card provided with a film liquid crystal display medium according to the present invention, FIG. 2 is an exploded perspective view showing the card structure, and FIG. 3 includes a film liquid crystal medium portion. It is a card sectional view.

The card (plastic card (1)) structure of this embodiment is roughly classified into an oversheet base material (1-1), a core base material (1-2), and an IC card substrate (1-3). Consists of.

The oversheet base material (1-1) serves as the outermost surface layer of this card, and is a colored or colorless transparent plastic such as polyethylene terephthalate.
Polyester resins such as polyethylene naphthalate and polycarbonate, or polymer alloy resins and polyester copolymers using them as one composition, vinyl chloride, ABS resin, polypropylene, polystyrene, polymethylmethacrylate, cellulose propionate, cellulose Acetate butyrate or the like can be used.
A sheet having a thickness of 16 to 200 μm can be appropriately used, but in order to maintain quality such as curl prevention of a card, it is preferable to use a sheet using the same thickness on the front and back sides, if possible, of the same lot. preferable. If necessary, the oversheet substrate can be subjected to a printing process such as a printing layer, a hiding layer, a protective layer or a coating process. However, so that the display on the film display section (2) can be visually confirmed,
It is preferable not to perform processing such as printing on a region overlapping the film display portion (2).

The core base material (1-2) is intended for molding the IC card base material (1-3) into scissors from both sides, and is a overseat base material (1-1).
Similarly colored or colorless transparent plastics such as polyethylene terephthalate, polyethylene naphthalate,
Polyester resins such as polycarbonate, or polymer alloy resins, vinyl chloride, ABS resins, polypropylene, polystyrene, etc. using them as one composition
Poly (methyl methacrylate), cellulose propionate,
Cellulose acetate butyrate or the like can be used. As the core base material (1-2), two sheets having a thickness of 0.2 to 0.35 mm can be used, or a plurality of sheets having a thickness of 0.03 to 0.16 mm can be stacked to form a core base material. . If necessary, the core substrate can be subjected to printing processing such as a printing layer and a concealing layer and coating processing. Further, it is preferable to process at least a portion corresponding to the back surface of the cholesteric liquid crystal film for display to black or a color close to black in order to increase the apparent contrast of the selective reflection of the liquid crystal. Further, in order to alleviate molding defects due to the thickness of the chip provided on the IC substrate (1-3) and the thickness of the film display medium and the pressure during lamination, specific portions of a plurality of sheets are cut out in a window shape in advance. It is possible to achieve the smoothness and thickness uniformity described in JIS and the like during final card molding.

The IC card substrate (1-3) is an intermediate for manufacturing an IC card equipped with a display function according to the present invention, and has an antenna coil, wiring, an IC chip, a power circuit, and a substrate having a size smaller than the card shape. A film display medium is mounted.

As the substrate (1-3a), glass epoxy can be used as in the conventional printed circuit board, but a polyimide resin film substrate or a polyimide resin film substrate is used for the purpose of improving heat resistance, bending resistance, and thinning. Polyethylene naphthalate (P
EN) film substrates may also be used. Other,
Any material generally used for printed boards can be used as a material for the board (1-3a).

The material for the antenna coil and the wiring (1-3b) is not particularly limited as long as it has sufficient conductivity, but copper is preferable because it is inexpensive, and gold, silver and carbon are also preferable. Can also be used. The specific antenna coil pattern can be changed according to the frequency of the electromagnetic wave used, and can be provided by winding coil, etching, or printing. A pattern can also be formed in the wiring by etching, plating, printing, soldering with the antenna coil, the control IC (1-3c), the film display medium (2-1), a conductive adhesive, A circuit is formed by being electrically connected by an anisotropic conductive material or the like.

The control IC (1-3c) is a power supply circuit that rectifies the alternating current excited by the antenna coil, a processor that processes the original function of the IC card, and a film display medium (2-) based on the signal obtained from the processor. The driver for controlling 1) may be provided as a single chip, or may be composed of a plurality of modules. Further, an IC chip of a type in which a contact type IC chip for communicating by contact with an external terminal and an IC chip for non-contact communication can be used together in one IC, or a contact type IC chip is provided. However, in that case, it is preferable that a part of the wiring connection and the IC terminal (3) be processed after the card molding. The display signal output from the driver IC chip for display control is coupled to the film display medium (2-1) via the wiring on the IC substrate (1-3a).
In that case, a known anisotropically conductive material can be used, and it is preferable to use an anisotropically conductive pressure-sensitive adhesive sheet having a thickness of 10 to 20 μm.

The film display medium (2-1) is a film made of a pair of cell base materials (2-1a) provided with a transparent conductive layer (2-1b), a spacer and a sealant (2-1c). It is obtained by enclosing the liquid crystal material (2-1d) in a cell.

The cell substrate (2-1a) may be a film having transparency, toughness, flexibility and a smooth surface, but polyethylene terephthalate, polyarylate, polycarbonate, polyether sulfone, epoxy. A resin film used as a base material for a normal film LCD such as is preferable, and two sheets having a thickness of 50 to 400 μm are used in combination. If necessary, polyvinyl alcohol copolymer, polyvinyl alcohol, SiOx, SiNx are provided by coating or vapor deposition to improve the barrier resistance, and known UV absorbers are impregnated or coated to improve the light resistance. May be.

The transparent conductive layer (2-1b) is formed of a transparent conductive material such as indium tin oxide (ITO), tin oxide or zinc oxide by a known method such as a sputtering method, a vacuum vapor deposition method or a CVD method ( It can be formed by setting a thickness of 100 to 2500Å). In addition, a conductive paste can be used for a part of wiring for ensuring vertical conduction in the cell.

The spacer and the sealant (2-1c) are
For maintaining a gap between the two cell base materials (2-1a), various liquid crystal cell materials such as Mylar, alumina, and polymer beads can be used. A sealant for LCD panels such as DSK-7 (manufactured by Shikoku Kasei Co., Ltd.) and DSA-001 (manufactured by Dainippon Ink and Chemicals) has a diameter of 3 to 20 μm.
It is preferable to mix the spacers and to arrange the spacers in the outer frame of the display section provided on the cell substrate (2-1a).

As the liquid crystal material (2-1d), a single kind or a plurality of kinds of liquid crystal compounds or a liquid crystal mixture can be used, but the liquid crystal system or mixture used has selective reflection in the visible region under the use environment. However, it is sufficient if it can be driven by voltage stimulation. Such liquid crystal materials include cholesterol halides such as cholesteryl bromide and cholesteryl chloride, monocarboxylic acid cholesterol esters and monocarboxylic acid sitosterol esters such as cholesteryl acetate and cholesteryl propionate, cholestanol esters of benzoic acid derivatives, and dicarboxylic acid esters. A cholesterol derivative that exhibits liquid crystallinity as a simple substance such as a basic acid zircholesteryl ester can be used. Further, a compound such as a Schiff base type, an azo type, an ester type or a biphenyl type, which is originally a nematic liquid crystal, has a 2-methylbutyl group or a 3-methylbutoxy group at the end thereof,
Chiral nematic liquid crystals with optically active branched alkyl or alkoxy groups such as methylhexyl groups, or mixed systems of chiral nematic liquid crystals with these optically active substances introduced into general nematics or commercially available chiral agents (Merck) S-811, S-1011, R-101
1, CB15, etc.) can be used. Further, these liquid crystal materials are appropriately selected and blended in consideration of the melting point, viscosity, refractive index anisotropy (Δn), dielectric anisotropy (Δε) of the materials, and phase transition temperature of the isotropic liquid and the liquid crystal. Can be used.

[0029]

Embodiments of the present invention will be specifically described below with reference to the drawings, but the present invention is not limited to the materials and configurations used in this embodiment.

A sealing agent DSA-001 (manufactured by Dainippon Ink and Chemicals, Inc.) in which polymer beads having a diameter of 5 μm (manufactured by Sekisui Fine Chemical Co., Ltd.) are mixed as spacers into a cell substrate made of a polycarbonate having an ITO electrode and having a thickness of about 200 μm. ) Was applied so as to surround the electrode formation portion, and was adhered to the other cell base material, and then baked and cured to form a 1 × 2 cm film-shaped cell.

As the cholesteric liquid crystal material, liquid crystal E4 is used.
4 (Merck) /80.1% by weight, chiral agent S81
1 (manufactured by Merck) /16.0% by weight, chiral agent S10
11 (manufactured by Merck & Co.) / 3.9 parts by weight were mixed, and the mixture was injected into a film cell by a vacuum injection method to seal the injection port. After the cell was created, when stress was applied to the entire surface of the cell with a finger, the liquid crystal layer was in the P orientation, and a green color at 530 nm was shown as a reflection spectrum peak. The change from the P-oriented state to the F-oriented state was observed at about 15V.

On the other hand, 1 on a 50 μm thick polyimide substrate.
From the conductive film provided with 0 μm thick copper foil,
Mask the circuit parts such as wiring and wiring, and use the etching method.
An IC circuit board was obtained. Non-contact I to this IC circuit board
Mount the C chip and driver chip by soldering
The above film liquid crystal display medium is used as an anisotropic conductive sheet FP2.
70 using 322D (Sony Chemical Co., Ltd.)
° C, 0.2 MPa / cm ²Heat press under the condition of 5 sec
Was made to adhere.

The IC circuit board containing the film display medium thus obtained was perforated with the same type as the film display medium, and PE of 0.1 mm thickness was formed so that the films would not overlap.
Three TG films PCT-010M (manufactured by Taihei Chemicals Co., Ltd.) are stacked, two ordinary films are stacked on the back side of the IC circuit board, and then laminated by a high temperature vacuum press (Kitagawa Seiki Co., Ltd.). Processed. Further, the same film was laminated on the front and back, and subjected to a laminate molding process again. Equipped with a film display function by extracting into a card shape I
I got a C card.

MFR which is a Reader / Writer for a non-contact IC card which transmits a 13.56 MHz signal
D560 (manufactured by Philips Semiconductor Co.)
It was confirmed that the card liquid crystal was mounted on the card and displayed (from P orientation to F orientation). After confirming that it was displayed for a while even after moving away from the Reader / Writer, the card was slightly bent several times, and the entire surface of the liquid crystal display returned to the original green color (see FIG. 4).

[0035]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a film-shaped display medium using a polymer network liquid crystal which does not require a polarizing film or the like is used, so that it can be electrically formed into a card-shaped limited thickness. It became possible to mount a display medium that can control the display. Further, according to the present invention, since there is no need to provide a power supply unit such as a battery or a solar battery in the card and it is not necessary to provide a high voltage or another erasing mechanism for erasing the display, the number of parts is small and the same liquid crystal It has become possible to significantly reduce the manufacturing cost and manufacturing process for display mounted IC cards.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an embodiment of an IC card with a display function according to the present invention.

FIG. 2 is an exploded perspective view showing the overall layer structure of an embodiment of an IC card with a display function according to the present invention.

FIG. 3 is a cross-sectional view showing the configuration of a specific portion of the embodiment of the display function-equipped IC card according to the present invention.

FIG. 4 is an example of an actual erasing operation for one embodiment of an IC card with a display function according to the present invention.

[Explanation of symbols]

1 ... Plastic card 1-1 ... Oversheet base material 1-2 ... Core substrate 1-3 ... IC card substrate 1-3a ... substrate 1-3b ... Antenna coil and wiring 1-3c ... Control IC 2 ... Display 2-1 ... Film display medium 2-1a ... Cell base material 2-1b ... Transparent conductive layer 2-1c ... Spacer and sealant 2-1d ... Liquid crystal material 3 ... IC terminal

Continued front page    F-term (reference) 2C005 MA29 MB01 MB02 MB08 MB10                       NA02 NA08 NA09 NB01 PA03                       QA03 QB01 RA04 TA21 TA22                 2H088 EA62 GA03 JA15 JA29 MA18                 5B035 AA05 BA03 BA05 BB09 CA01                       CA06 CA12 CA13 CA23

Claims (6)

[Claims] 1. A display function-equipped IC card having a built-in film liquid crystal element, wherein the contents of the card can be displayed by communication with an external device and the contents of the display can be erased by applying stress such as bending deformation. IC card with display function. 2. The IC card with a display function according to claim 1, wherein a cholesteric liquid crystal exhibiting bistability in a planar state and a focal conic state is used as a film liquid crystal element incorporated in the IC card with a display function. IC card with display function. 3. The IC card with a display function according to claim 1, wherein the film liquid crystal element is in a planar state when no voltage is applied, and is partially changed to a focal conic state by voltage application for display. An IC card with a characteristic display function. 4. The display function-equipped IC card according to claim 1, wherein a film liquid crystal element is provided on a circuit board embedded in the IC card. 5. A card-shaped molding is carried out by laminating a transparent resin base material on the entire surface or a part of a circuit board provided with the film liquid crystal element so that the display content of the film liquid crystal element can be confirmed at least. An IC card with a characteristic display function. 6. The IC card with a display function according to claim 1, wherein an electromagnetic wave from the outside is converted into electric power by an antenna coil provided on a circuit board embedded in the card and used for driving a film liquid crystal element. An IC card with a display function that is characterized by.