JP2003208582A - Ic card with liquid crystal display function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an IC card with a liquid crystal display function that has a display function viewable from outside the card and is drivable with low power. <P>SOLUTION: The IC card with a liquid crystal display function is an IC card with a display function. The IC card is embedded with a film-shaped display medium so that display on the film-shaped display medium can be viewed from outside the IC card. The film-shaped display medium is a liquid crystal display without a polarizing plate for display. The film-shaped display medium is arranged on an IC circuit board integrated in the IC card. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of an IC card equipped with a film-shaped liquid crystal display medium.

[0002]

2. Description of the Related Art IC cards are widely used for authentication and settlement of ID cards, credit cards, point cards and the like. The IC card is a semiconductor card embedded and molded in a plastic card. IC cards are broadly classified into contact type IC cards with terminals provided on the surface of the card and non-contact type IC cards with a built-in antenna. These contact type and non-contact type IC cards both exchange information with terminals. In order to electrically perform (for example, authentication and rewriting of stored contents), various means have been proposed for confirming recorded information when in use or when carried.

As a method of visualizing card information, Japanese Patent Laid-Open No. 5-201130 (Oki Electric Industry Co., Ltd.) and Japanese Patent Laid-Open No.
As described in -278332 (Ricoh Company, Ltd.),
A method has been devised in which a reversible heat-sensitive recording layer is provided on the surface of a card to record the number of points and the balance. 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 Subject to restrictions.

On the other hand, many attempts have been made to mount a display medium using voltage drive such as liquid crystal display on a card. This is being studied 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-63-16171 (Kansai NEC Corporation), JP-A-63-116380 (NEC NEC microcomputer system), JP-A-63-1
In 76671 (Oki Electric Industry Co., Ltd.), an IC card in which a liquid crystal display medium and a battery are mounted on a contact type IC card is shown for the purpose of use as a financial card or a credit card. 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-11-120320 (Toppan Printing Co., Ltd.), the ferroelectric liquid crystal for an IC card is disclosed, and in JP-A-10-154215 (Shinko Denki Co., Ltd.), a ferroelectric liquid crystal for a non-contact IC card is disclosed. Liquid crystal displays are under consideration.

[0006]

As described above, by mounting the liquid crystal display on the IC card, it is possible to display dynamic information, and it is possible to display the balance and personal information only when desired. On the other hand, in the case of an IC card provided with a liquid crystal display, there may be a problem of securing a power source necessary for driving the IC card. Therefore, in most of the cases of inventions in which a liquid crystal display is mounted on an IC card, a method of incorporating a battery or a solar cell in the IC card has been selected. The mounting of the battery on the card itself leads to an increase in cost including an increase in the number of parts and wiring, and has been a cause of slowing down the spread of IC cards having a voltage-driven display.

Further, when the liquid crystal display is mounted on an IC card, there are problems in the shape and thickness of the liquid crystal display. Up to now, glass substrates have been used for nematic liquid crystal displays, which are often used in calculators, due to the uniform thickness of the liquid crystal layer and various surface treatments, but liquid crystal displays formed on these glass substrates. Devices were generally difficult to introduce into card form due to thickness issues.

Although a liquid crystal display device using a plastic substrate has been put into practical use in recent years, a polarizing film of about 100 μm has to be used on both sides in actual use. After all, it was difficult to introduce it into a card shape in terms of thickness. Among them, although many IC cards equipped with a ferroelectric liquid crystal film have been devised, it is necessary to provide a polarizing film on the front and back of the liquid crystal display, the driving voltage is high, and the display can be made by bending the card due to its nature. It was not practical to use it in an IC card because of problems.

The present invention has been made in view of the above problems of the prior art, has a display function visible from the outside of the card, can be driven with low power, and is neither too thin nor too thick. It is an object of the present invention to provide an IC card with a liquid crystal display function, which is an IC card having a practically sufficient thickness (usually in the range of 0.6 to 0.9 mm).

[0010]

The invention according to claim 1 made in order to solve the above-mentioned problems is an IC card having a display function, and the display of the film-shaped display medium is visually observed from the outside of the IC card. A liquid crystal display in which the film display medium is embedded in the IC card as much as possible, and the film display medium does not include a polarizing plate for display,
An IC card with a liquid crystal display function, characterized in that the film-shaped display medium is provided on an IC circuit board incorporated in a C card.

According to a second aspect of the present invention, at least one layer made of a transparent material is provided in a region including a part or all of the upper part of the display portion of the film-shaped display medium, and only the transparent material is provided. 2. The IC card with a liquid crystal display function according to claim 1, wherein the display of the display section is visible through the layer of.

According to a third aspect of the present invention, the magnetic coupling coil provided on the IC circuit board is used to convert electromagnetic waves arriving from the outside of the IC card with a display function into electric power.
The IC with a liquid crystal display function according to claim 1, wherein the obtained electric power is used to drive the film-shaped display medium.
It's a card.

According to a fourth aspect of the invention, in the IC card with a liquid crystal display function according to any one of the first to third aspects, a polymer dispersed liquid crystal is used as the film-shaped display medium. is there.

According to a fifth aspect of the invention, there is provided the IC card with a liquid crystal display function according to the fourth aspect, wherein a polymer network type liquid crystal is used as the polymer dispersed liquid crystal.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The IC card with a display function referred to in the present invention is generally a contact type IC that communicates via electrical contacts.
Either a card, a non-contact type IC card that performs communication without using electrical contacts, or a composite type IC card that has both a contact type and a non-contact type functions with one sheet is applicable.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a diagram showing an embodiment of a card provided with a film-shaped display medium according to the present invention, FIG. 1 is a plan view, FIG. 2 is a developed perspective view showing the card structure, and FIG. 3 is a film liquid crystal medium. It is a card sectional view containing a part. The card (plastic card (1)) configuration of this embodiment is largely based on the oversheet base material (1-
1), core base material (1-2), and IC card substrate (1-
It consists of 3).

The oversheet base material (1-1) is 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 printing or coating such as a printing layer, a concealing layer and a protective layer. However, the film display (2)
It is preferable not to perform processing such as printing on the region overlapping the film display portion (2) so that the display of can be visually confirmed.

The core base material (1-2) is intended to mold the IC card base material into scissors from both sides, and is a colored or colorless transparent plastic such as polyethylene terephthalate, like the oversheet base material. , Polyester resins such as polyethylene naphthalate and polycarbonate, or polymer alloy resins using them as one composition, vinyl chloride, ABS resin,
Polypropylene, polystyrene, polymethylmethacrylate, cellulose propionate, cellulose acetate butyrate and the like can be used. The core substrate (1-2) is
Use two 0.2-0.35 mm thick sheets, or
It is possible to stack a plurality of sheets having a thickness of 03 to 0.16 mm to form a core base material.

At this time, in order to alleviate molding defects due to the thickness of the chips 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 pre-windowed. It can be cut into a shape, and it is possible to achieve the smoothness and the uniformity of thickness described in JIS etc. at the time of final card molding.

The IC card substrate (1-3) is an intermediate for manufacturing an IC card with a display function in the present invention, and has an antenna, a wiring, an IC chip, a power supply circuit and a film in a substrate shape having a size smaller than the card shape. A display medium is mounted. As the substrate (1-3a), glass epoxy can be used as in a conventional printed circuit board, but a polyimide resin may be used for the purpose of improving heat resistance and bending resistance. In addition, any material generally used for printed circuit boards can be used as a material for the substrate (1-3a).

The material of the antenna 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 others.
Gold, silver, carbon, etc. can also be used. The specific antenna pattern can be changed according to the frequency of the electromagnetic wave used, and can be provided by winding coil, etching, or printing. Also for wiring, a pattern can be formed by etching, plating, and printing.
A circuit is formed by soldering between C (1-3c) and the film display medium (2-1), and electrically connected by a conductive adhesive, an anisotropic conductive material, or the like.

The control IC (1-3c) is a power supply circuit for rectifying an alternating current excited by an antenna (coil), a processor for processing the original function of the IC card, and a film display medium (based on a signal obtained from the processor). A driver for performing the control of 2-1) may be provided as one chip,
It 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. It is also possible, but in that case, some wiring connections and I
The C terminal (3) is preferably processed after 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 material (2-1a) provided with a transparent conductive layer (2-1b) and a spacer and a sealant (2-1c). After encapsulating the liquid crystal material (2-1d) in the cell-shaped cell, the monomer component in the liquid crystal material can be fixed by being cured by UV irradiation from the outside.

The cell substrate (2-1a) may be a film having transparency, toughness and 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, coating with polyvinyl alcohol copolymer, polyvinyl alcohol, SiOx, SiNx or vapor deposition is performed to improve barrier resistance, and known UV absorbers are impregnated or coated to improve light resistance. May be. Further, in order to increase the scattering strength of the liquid crystal, it is preferable to provide a reflective layer such as Al vapor deposition on the back side of the display surface.

For the transparent conductive layer (2-1b), a transparent conductive material such as indium tin oxide (ITO), tin oxide, zinc oxide or the like is formed 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 sealant (2-1c) are
For maintaining a gap between two cell substrates, for example, Mylar,
Materials for various liquid crystal cells such as alumina and polymer beads can be used. DSK-7 (manufactured by Shikoku Kasei Co., Ltd.)
LC such as DSA-001 (manufactured by Dainippon Ink Co., Ltd.)
It is preferable to mix a spacer having a diameter of 5 to 20 μm with the D panel sealant and dispose the spacer on the outer frame of the display section provided on the cell substrate (2-1a).

As the liquid crystal material (2-1d), single or plural kinds of liquid crystal compounds or liquid crystal mixtures can be used, and nematic liquid crystal is particularly preferable. Further, these liquid crystal materials have melting points, viscosities, refractive index anisotropies (Δn),
It can be appropriately selected and blended in consideration of the dielectric anisotropy (Δε), the phase transition temperature of the isotropic liquid and the liquid crystal, the solubility of the polymerizable composition, and the like. Kaihei 5-2
24179 (Dainippon Ink and Chemicals, Inc.) and JP-A-7-266878 (Dainippon Ink and Chemicals, Inc.)
According to the liquid crystal material described in. Examples of liquid crystal materials include nematic liquid crystals, smectic liquid crystals, and cholesteric liquid crystals. Such liquid crystal materials include benzoic acid ester-based, cyclohexylcarboxylic acid ester-based, phenylcyclohexane-based, biphenylcyclohexane-based, pyrimidine-based, dioxane-based, cyclohexanecyclohexane ester-based, cyclohexylethane-based, tolan-based,
Various liquid crystal compounds such as ankenyl compounds are used.

As such a liquid crystal material, for example, 4
-Substituted benzoic acid-4'-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid-4'-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid-4'-substituted biphenyl ester, 4- (4-substituted cyclohexanecarbonyloxy) Benzoic acid-4'-substituted phenyl ester, 4- (4-substituted cyclohexyl) benzoic acid-4'-
Substituted phenyl ester, 4- (4-substituted cyclohexyl) benzoic acid-4′-substituted cyclohexyl ester, 4
Examples thereof include-substituted phenyl-4'-substituted cyclohexane, 4-substituted biphenyl-4'-substituted cyclohexane, 2- (4-substituted phenyl) -5-substituted pyridine and the like.

As the transparent solid substance forming the polymer-dispersed liquid crystal, it is preferable to use a photocurable resin obtained by polymerizing a polymer-forming monomer or oligomer. The photocurable resin contains at least a polymer-forming monomer or oligomer and a photopolymerization initiator, and may be any one that induces phase separation from the liquid crystal material by the polymerization thereof.

Examples of the polymer-forming monomer include methyl, ethyl, propyl, butyl, amyl, 2-ethylhexyl, octyl, nonyl, dodecyl, hexadecyl, octadecyl, nonadecyl, cyclohexyl, norbornyl,
Isobonyl, cyclopentenyl, perfluoro-substituted alkyl, benzyl, methoxyethyl, butoxyethyl, ethylene oxide-added alkyl, propylene oxide-added alkyl, phenoxyethyl, allyl, methallyl, glycidyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-chloro- Acrylate, methacrylate or fumarate having a substituent such as 2-hydroxypropyl, dimethylaminoethyl, diethylaminoethyl and the like.

In addition to these, ethylene glycol, polyethylene glycol, propylene glycol,
Mono (meth) acrylates or poly (meth) acrylates such as polypropylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, trimethylolpropane, glycerin and pentaerythritol, vinyl acetate, vinyl butyrate or Vinyl benzoate, acrylonitrile, cetyl vinyl ether, limonene, cyclohexene, diallyl phthalate, diallyl isophthalate, 2
-, 3- or 4-vinyl pyridine, acrylic acid, methacrylic acid, acrylamide, methacrylamide, N-hydroxymethoxymethyl acrylamide or N-hydroxyethyl methacrylamide and their alkyl ether compounds, trimethylolpropane to ethylene oxide or propylene oxide Di- or tri- (meth) acrylate of triol obtained by addition of styrene, di- (meth) acrylate of diol obtained by addition of ethylene oxide or propylene oxide to neopentyl glycol, 2-hydroxyethyl (meth) acrylate and phenyl isocyanate Alternatively, a reaction product with n-butylisocyanate, poly (meth) acrylate of dipentaerythritol, or poly (meth) acrylate of tris- (hydroxyethyl) -isocyanuric acid. (Meth) acrylate, tris -
Poly (meth) acrylate of (hydroxyethyl) -phosphoric acid, mono (meth) acrylate or di (meth) acrylate of di- (hydroxyethyl) -dicyclopentadiene, caprolactone-modified hydroxypentavalene neopentyl glycol (meth) acrylate , Linear aliphatic di (meth) acrylate, polyolefin-modified neopentyl glycol (meth) acrylate, and the like.

Examples of the polymer-forming oligomer include epoxy (meth) acrylate and polyester (meth).
Acrylate, polyurethane (meth) acrylate, polyether (meth) acrylate and the like can be used.

Examples of the photopolymerization initiator include 2-hydroxy-2-methyl-1-phenylpropan-1-one (“Darocur 1173” manufactured by Merck), 1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba Geigy). Irgacure 184 "), 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1-
1-on (“Darocur 1116” manufactured by Merck), benzyl dimethyl ketal (“Irgacure 651” manufactured by Ciba-Geigy), 2-methyl-1- [4- (methylthio)
Phenyl] -2-morpholinopropanone-1 (“Irgacure 907” manufactured by Ciba Geigy), 2,4-diethylthioxanthone (“Kayacure DET manufactured by Nippon Kayaku Co., Ltd.”)
X ") and a mixture of ethyl p-dimethylaminobenzoate, acyl phosphonate (Lucirin TPO manufactured by BASF), and the like.

[0036]

EXAMPLES Examples of the present invention will now be described in detail with reference to the drawings, but the present invention is not limited to the materials and structures used. Polymer beads having a diameter of 10 μm (manufactured by Sekisui Fine Chemical Co., Ltd.) were dispersed as spacers on a polycarbonate cell substrate having a thickness of about 200 μm on which an ITO electrode was formed, and a sealant (DSA-001 (manufactured by Dainippon Ink and Chemicals, Inc.) Was adhered to the other cell base material coated with and baked and cured to form a 2 × 4 cm film-shaped liquid crystal cell, and then a liquid crystal composition, a photocurable resin, and a liquid crystal containing a photopolymerization initiator. Ink (PNM-17
0) (manufactured by Dainippon Ink and Chemicals, Inc.) was injected using a vacuum injection method. Thereafter, while maintaining the temperature of the substrate at 36 ° C., ultraviolet rays were irradiated for 60 seconds so that the illuminance on the irradiation surface of the substrate became 50 mW / cm ² or more, and a cloudy and opaque film liquid crystal display medium was obtained.

On the other hand, 1 on a 50 μm thick polyimide substrate.
The conductive film provided with a copper foil of 0 μm is used to mask the circuit parts such as the antenna and wiring, and the
A C circuit board was obtained. A non-contact IC chip and a driver chip are mounted on this IC circuit board by soldering, and the above film liquid crystal display medium is used as an anisotropic conductive sheet FP2322.
D (Sony Chemical Co., Ltd.), 70 ° C., 0.
Thermal pressing was performed under the conditions of 98 MPa and 5 seconds to bring them into close contact.

The IC circuit board containing the film display medium thus obtained was perforated with holes of the same type as the film display medium, and a 0.1 mm thick amorphous polyester [PETG (Eastman Chemical Co., Ltd.]] film PCT-010M (manufactured by Taihei Chemicals Co., Ltd.), and two ordinary films on the back side of the IC circuit board, and then a high temperature vacuum press (Kitagawa Seiki) Laminated molding process was performed by the company. Further, the same film was laminated on the front and back, and subjected to a laminate molding process again. A card with a film display function was obtained by extracting it into a card shape.

MFR which is a Reader / Writer for a non-contact IC card which transmits a signal of 13.56 MHz
D560 (manufactured by Philips Semiconductor Co.)
The card was brought close to, and it was confirmed that the film liquid crystal mounted on the card was displayed.

[0040]

As described above, by using the film-like display medium using the network liquid crystal which is a polymer-dispersed liquid crystal which does not require the polarizing film according to the present invention, a card-shaped limited thickness is obtained. In addition, it is possible to mount a display medium that can electrically control the display. Further, the IC and the display medium mounted on the card can be driven without providing a power supply unit such as a battery or a solar cell in the card. As a result, it is possible to significantly reduce the manufacturing cost and the manufacturing process for a similar liquid crystal display mounted IC card with a small number of parts.

[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 an overall layer structure of an embodiment of an IC card with a display function according to the present invention.

FIG. 3 is a diagram further illustrating the configuration of a specific unit in the embodiment of the 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 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

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI Theme Coat (reference) G06K 19/00 K (72) Inventor Kazuo Kobayashi 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Stock In-house (72) Inventor Naoyuki Sakata 1-5-1, Taito, Taito-ku, Tokyo Top-term printing company F term (reference) 2C005 MA27 NA09 NB01 NB39 QB01 QB05 2H088 EA03 EA22 EA27 EA62 HA01 HA05 HA06 HA08 JA02 JA04 JA06 MA20 2H089 HA04 JA04 KA04 QA16 RA04 TA01 TA07 UA09 5B035 AA00 AA05 BA03 BA05 BB09 CA01 CA06 CA12 CA23

Claims (5)

[Claims] 1. An IC card having a display function, wherein the film-shaped display medium is embedded in the IC card so that the display of the film-shaped display medium can be viewed from the outside of the IC card, and A liquid crystal display function characterized in that the film-shaped display medium is a liquid crystal display without a polarizing plate for display, and the film-shaped display medium is provided on an IC circuit board incorporated in an IC card. IC card with. 2. A transparent material alone is provided in a region including a part or all of the upper part of the display portion of the film-shaped display medium.
The IC card with a liquid crystal display function according to claim 1, wherein the above-mentioned layers are provided, and the display of the display section can be viewed through the layer made of only the transparent material. 3. A magnetic coupling coil provided on the IC circuit board is used to convert electromagnetic waves arriving from the outside of the IC card with a display function into electric power, and the electric power obtained is transferred to the film-shaped display medium. The IC card with a liquid crystal display function according to claim 1, which is used for driving. 4. The IC card with a liquid crystal display function according to claim 1, wherein a polymer-dispersed liquid crystal is used as the film-shaped display medium. 5. The IC card with a liquid crystal display function according to claim 4, wherein a polymer network type liquid crystal is used as the polymer dispersed liquid crystal.