JP2007193114A - Image display medium and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display medium which suppresses a damage to a thin film electrode generated when a thermoplastic film is thermally pressed, and to provide a manufacturing method of the image display medium. <P>SOLUTION: The image display medium 100 substantially comprises: a display layer 101 composed of liquid crystal, etc.; transparent first and second substrates 104, 105 which are disposed oppositely via the display layer 101 and have transparent first and second thin film electrodes 102, 103; first and second take-out electrodes 106, 107 which are formed on the surfaces of the first and second thin film electrodes 102, 103 and perform electric connection with the outside; a first reinforcing member 111 formed on the surface of the first substrate 104 so as to be extended over the second substrate 105 and the first take-out electrode 106; and a thermoplastic film 200 formed so as to cover the whole of a constituent part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flexible image display medium whose entire surface is covered with a thermoplastic film and a method for manufacturing the same.

  In recent years, image display media called electronic paper or digital paper having the advantages of both electronic display and paper have attracted attention as image display media, in addition to paper media and electronic display devices.

  In addition, development of an IC card to which a display function is added using such electronic paper has been performed, and there is a technique of forming a thermoplastic film on the surface by thermocompression bonding in order to protect the IC card from external damage.

  8A and 8B are cross-sectional views showing respective manufacturing steps of an image display medium (IC card with electronic paper) having a conventional thermoplastic film.

  An image display medium 100 includes a display layer 101 made of liquid crystal or the like, and transparent first and second substrates 104 having transparent first and second thin-film electrodes 102 and 103 arranged to face each other with the display layer 101 interposed therebetween. 105 and first and second extraction electrodes 106 and 107 for electrical connection with the outside formed on the surfaces of the first and second thin film electrodes 102 and 103 (the second extraction electrode is not shown) And a thermoplastic film 200 having a take-out hole 110 formed on the surface so as to cover the entire component part and for connecting to the first and second take-out electrodes 106 and 107 from the outside. Outlined.

  The thermoplastic film 200 is formed by covering the image display medium 100 with the first, second, and third thermoplastic members 201, 202, and 203 and bonding the entire image display medium 100 fixed on a table (not shown). ) Is used by heating and pressurizing from above in the vertical direction (FIG. 8A). As a result, the image display medium 100, the first thermoplastic member 201, and the second thermoplastic member 202 are thermocompression bonded, and the first thermoplastic member 201 and the second thermoplastic member 202 are the thermoplastic film 200. And formed on the surface of the image display medium 100 (FIG. 8B).

  However, in the manufacturing process of the image display medium 100, it is difficult to completely dispose the display layer 101, the second thin film electrode 103, the second substrate 105, and the first extraction electrode 106 without any gap. The 1st clearance gap 108 of 1 micrometer-100 micrometers arises.

  Then, when the first thermoplastic member 201 and the second thermoplastic member 202 are thermocompression bonded to the image display medium 100, the first substrate 104 and the first thin film electrode 102 are directly above the first gap 108. The located portion is deformed by pressure and becomes a damaged portion 114.

  In the damaged portion 114, there is a high risk that the first thin film electrode 102 is disconnected. In addition, even if it is not disconnected at the time of manufacture, there is a high possibility that the image display medium 100 is bent during use or a current is passed through the first thin film electrode 102 due to accumulated damage.

  In general, when the image display medium 100 is fixed on a table and heated and pressurized by a bonding tool from above, a buffer material is sandwiched between the image display medium 100 and the bonding tool. Due to its flexibility, the cushioning material can uniformly heat and press each part without being greatly affected by the unevenness of the surface due to the shape of the image display medium 100. There is a problem that pressure is continuously applied even to weak parts. Therefore, the first substrate 104 and the first thin film electrode 102 located above the second substrate 105 and the second thin film electrode 103 located below the thermoelectric pressure bonding of the thermoplastic film by the bonding tool. Damage portion 114 is likely to occur.

On the other hand, a technique has been disclosed that prevents cracks in the thin film electrode of a liquid crystal display device by applying no pressure to the end when the film-like circuit electrode is crimped to the takeout portion of the film liquid crystal display device. (For example, Patent Document 1).
JP 2000-284308 A

  However, when the image display medium is covered with a thermoplastic film, it is necessary to heat and press the entire image display medium, and the technique described in Patent Document 1 in which pressure is applied only to a part of the electrodes to be bonded is used. I can't.

  Accordingly, an object of the present invention is to provide an image display medium that suppresses damage to a thin film electrode that occurs when a thermoplastic film is thermocompression bonded, and a method for manufacturing the same.

  In one aspect of the present invention, in order to achieve the above object, in an image display medium whose entire surface is covered with a thermoplastic film, the display layer and the first and second layers disposed opposite to each other with the display layer interposed therebetween First and second substrates having thin film electrodes; first and second extraction electrodes formed on the surfaces of the first and second thin film electrodes for electrical connection to the outside; and A position straddling the second substrate and the first extraction electrode on the first substrate side, and a position straddling the first substrate and the second extraction electrode on the second substrate side; And an reinforcing member formed on at least one of the image display medium.

  According to the one aspect of the present invention, it is possible to suppress damage to the first thin film electrode that occurs when the thermoplastic film is thermocompression bonded, and to prevent disconnection.

  The reinforcing member has a position straddling the second substrate on the first substrate side and the first extraction electrode, and the first substrate and the second extraction electrode on the second substrate side. It may be formed at both the position straddling.

  Thus, when the thermoplastic film is thermocompression bonded to the image display medium, the first and second thin film electrodes are used even when the front and back surfaces are heated and pressed under the same conditions, not in one direction. It is possible to suppress damage to the wire and prevent disconnection.

  The reinforcing member formed at a position straddling the second substrate and the first extraction electrode on the first substrate side can straddle the first substrate and the second extraction electrode. The reinforcing member having such a size and formed at a position straddling the first substrate and the second extraction electrode on the second substrate side is the second substrate and the first substrate. You may have a magnitude | size which can straddle an extraction electrode.

  As a result, when the mechanical strength of the connecting portion between the first and second thin film electrodes and the first and second extraction electrodes is increased and the image display medium is bent and deformed, the first and second thin film electrodes are formed. It is possible to prevent damage such as disconnection occurring in the thin film electrode.

  A reinforcing member formed at a position straddling the second substrate on the first substrate side and the first extraction electrode is formed on the surface of the first substrate, and on the second substrate side. The reinforcing member formed at a position straddling the first substrate and the second extraction electrode may be formed on the surface of the second substrate.

  The reinforcing member formed at a position straddling the second substrate on the first substrate side and the first extraction electrode is formed inside the first substrate, and the reinforcing member is formed on the second substrate side. The reinforcing member formed at a position straddling the first substrate and the second extraction electrode may be formed inside the second substrate.

  According to another aspect of the present invention, in order to achieve the above object, in the method of manufacturing an image display medium whose entire surface is covered with a thermoplastic film, the first and second thin film electrodes are sandwiched between the display layers. The first and second substrates having the first and second substrates are arranged opposite to each other, and first and second extraction electrodes for electrically connecting to the outside are formed on the surfaces of the first and second thin film electrodes. Step, a position straddling the second substrate on the first substrate side and the first extraction electrode, and the first substrate and the second extraction electrode on the second substrate side. And a second step of forming a reinforcing member in at least one of the straddling positions, and a method for manufacturing an image display medium.

  The second step includes a position straddling the second substrate on the first substrate side and the first extraction electrode, the first substrate on the second substrate side, and the second substrate. The reinforcing member may be formed both at a position straddling the extraction electrode.

  Examples of the image display medium include liquid crystal types such as a bistable nematic liquid crystal type, a cholesteric liquid crystal type, a ferroelectric liquid crystal type, and a smectic A liquid crystal type, an optical writing liquid crystal type, a toner display type, an electrophoretic type, and an electrochromic type. , A MEMS type IC card with a display function using electronic paper, and the display layer is composed of a layer having liquid crystal, colored particles, etc., depending on the type of the image display medium.

  One of the first and second substrates located at least on the display side is made of a transparent resin material such as polyethylene terephthalate (PET), polynaphthalate, polycarbonate, polyether sulfone having a thickness of 100 μm.

  At least one of the first and second thin film electrodes is a transparent electrode made of, for example, 50 nm indium tin oxide (ITO) or zinc oxide.

  Depending on the type of the display layer, the first and second thin film electrodes are, for example, both in the form of a full surface electrode, one in the form of a full surface electrode and the other in the form of a pixel electrode, and one in the form of a scan electrode and the other in the form of a signal electrode. A form of a line electrode that scans by moving one on the signal electrode and the other on the signal electrode can be considered.

  The first and second extraction electrodes are made of a metal such as Ni having a thickness of 140 μm, for example.

  The reinforcing member is made of metal such as stainless steel (SUS), Al alloy, Ni alloy, ceramic, glass, or a resin harder than the first and second substrates (for example, melamine resin, bakelite resin, acrylonitrile / butadiene / styrene). (ABS) resin, polyphenylene sulfide, etc.), for example, a plate-like member having a thickness of 25 to 200 μm.

  The thermoplastic film is made of a transparent thermoplastic resin such as PET, amorphous PET (PET-G), polyvinyl chloride, or polyester.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the image display medium which suppresses the damage to the thin film electrode which arises when thermocompression bonding a thermoplastic film, and its manufacturing method.

[First Embodiment]
(Configuration of image display medium)
FIGS. 1A and 1B are a top view and a bottom view of an image display medium according to the first embodiment of the present invention, and FIGS. 2A and 2B are cross-sectional views. 2 (a) and 2 (b) are diagrams in which cut surfaces along chain lines AA ′ and BB ′ in FIG. 1 are viewed in the directions of arrows in the drawing.

  The image display medium 100 includes a transparent first and second thin film electrodes 102 and 103 that are disposed opposite to each other with a display layer 101 made of liquid crystal or the like interposed therebetween. Substrate 104, 105, first and second extraction electrodes 106, 107 for electrical connection with the outside formed on the surfaces of first and second thin film electrodes 102, 103, and second substrate 105 And a reinforcement formed on the surface of the first substrate 104 so as to straddle the first extraction electrode 106 and at a position straddling the second substrate on the first substrate side and the first extraction electrode. The first reinforcing member 111 as a member and a thermoplastic film 200 formed so as to cover the entire constituent part are schematically configured.

  The first gap 108 is a gap generated between the display layer 101, the second thin film electrode 103, the second substrate 105, and the first extraction electrode 106 in the manufacturing process of the image display medium 100. The gap width is, for example, 1 μm to 100 μm.

  The second gap 109 is a gap generated between the display layer 101, the first thin film electrode 102, the first substrate 104, and the second extraction electrode 107 in the manufacturing process of the image display medium 100. The gap width is, for example, 1 μm to 100 μm.

  The plate-like first reinforcing member 111 is formed on the first substrate 104 so as to cover at least a portion located immediately above the first gap portion 108, but the size and shape are limited to this. For example, as shown in FIGS. 1A and 2B, the first and second thin film electrodes 102 and 103 are formed so as to cover the second gap 109 as well. In addition, it is possible to increase the resistance to bending deformation of the connection portion between the first extraction electrodes 106 and 107.

  Further, the first reinforcing member 111 may be formed not only on the surface of the first substrate 104 but also inside the first substrate 104.

  The thermoplastic film 200 is formed by thermocompression bonding the first, second, and third thermoplastic members 201, 202, and 203, which will be described later, to the surface of the image display medium 100. As shown in FIG. An extraction hole 110 for connecting to the first and second extraction electrodes 106 and 107 from the outside is provided. The take-out hole 110 may be formed on the opposite surface shown in FIG. Further, the extraction hole 110 may be provided after the thermoplastic film 200 is formed on the surface of the image display medium 100.

  The first and second thermoplastic members 201 and 202 are melted, for example, on the surface of a mother layer made of PET having a thickness of 100 μm, for example, a hot-melt adhesive having a thickness of 25 μm, a copolyester-based hot melt adhesive, or the like. Has a layer. The molten layer has a lower melting point than the mother layer, and thermocompression bonding is performed with the surface on which the molten layer is formed facing the image display medium 100 surface side.

  As shown in FIGS. 1A and 1B, an IC chip 113 such as a wireless tag can be mounted as necessary.

  FIG. 3 is an exploded perspective view of the image display medium. The thermoplastic film 200 is represented as first, second, and third thermoplastic members 201, 202, and 203 before thermocompression bonding. The first and second thermoplastic members 201 and 202 have a plate shape that covers the surface of the image display medium 100, and the third thermoplastic member 203 has a frame shape that covers the side surface.

(Production of image display medium)
FIGS. 4A to 4C are cross-sectional views showing each manufacturing process of the image display medium according to the first embodiment of the present invention. 4A to 4C are the same as the cross section shown in FIG.

  First, as shown in FIG. 4A, the image display medium 100 before forming the thermoplastic film 200 is prepared, and the partial surface of the first substrate 104 that is located immediately above the first gap 108 is covered. Thus, the first reinforcing member 111 is formed.

  Next, as shown in FIG. 4B, the image display medium 100 is covered with the first, second, and third thermoplastic members 201, 202, and 203, and the entire image display medium 100 fixed on the table is covered. Using a bonding tool (not shown), heat and pressure are applied from above in the vertical direction with the cushioning material interposed therebetween.

  At this time, since the first reinforcing member 111 is present, the applied pressure is dispersed and does not concentrate on the portion of the first substrate 104 located immediately above the first gap portion 108.

  As a result, as shown in FIG. 4C, the portion of the first substrate 104 and the first thin film electrode 102 located immediately above the first gap 108 is not deformed by pressure, and the thermoplastic film 200 is deformed. Thus, the image display medium 100 covering the surface can be formed.

(Effects of the first embodiment)
According to the first embodiment, by forming the first reinforcing member 111 on the image display medium 100, it is possible to suppress damage to the first thin film electrode 102 that occurs when the thermoplastic film 200 is thermocompression bonded. Therefore, it becomes possible to prevent disconnection.

  In addition, the first and second thin film electrodes 102 and 103 and the first and second thin film electrodes 102 and 103 are formed by covering the first reinforcing member 111 so as to cover the first gap 108 and the second gap 109. When the image display medium 100 is bent and deformed by increasing the mechanical strength of the connecting portion of the extraction electrodes 106 and 107, damage such as disconnection occurring in the first and second thin film electrodes can be prevented.

[Second Embodiment]
In the second embodiment, unlike the first embodiment, when the thermoplastic film is thermocompression bonded to the image display medium, it is created by heating and pressurizing both front and back surfaces under the same conditions, not in one direction. The image display medium will be described. In this case, damage may occur on both the first and second substrate sides.

(Configuration of image display medium)
5A and 5B are a top view and a bottom view of the image display medium according to the second embodiment of the present invention, and FIGS. 2A and 2B are cross-sectional views. 2 (a) and 2 (b) are diagrams in which cut surfaces along chain lines AA ′ and BB ′ in FIG. 1 are viewed in the directions of arrows in the drawing.

  The difference from the image display medium 100 according to the first embodiment is that the second reinforcement as a reinforcement member formed at a position straddling the first substrate on the second substrate side and the second extraction electrode. The member 112 is formed on the surface of the second substrate 105 so as to straddle the first substrate 104 and the second extraction electrode 107. Since other components are the same as those in the first embodiment, the description thereof is omitted.

  The plate-like second reinforcing member 112 is formed on the second substrate 105 so as to cover at least a portion located immediately above the second gap portion 109, but the size and shape are limited to this. For example, as shown in FIGS. 5 (b) and 6 (a), the first and second thin film electrodes 102, 103 are formed so as to cover the first gap portion 108 as well. And the tolerance with respect to the bending deformation of the connection part of the 1st and 2nd extraction electrodes 106 and 107 can be raised.

  Further, the second reinforcing member 112 may be formed not only on the surface of the second substrate 105 but also inside the second substrate 105.

(Production of image display medium)
7A to 7C are cross-sectional views showing each manufacturing process of the image display medium according to the first embodiment of the present invention. In addition, the cross section shown to Fig.7 (a)-(c) is the same as the cross section shown to Fig.6 (a).

  First, as shown in FIG. 7A, the image display medium 100 before forming the thermoplastic film 200 is prepared, and the partial surface of the first substrate 104 located immediately above the first gap 108 is covered. As described above, the second reinforcing member 112 is formed so as to cover the partial surface of the first reinforcing member 111 located immediately below the second gap portion 109 of the second substrate 105.

  Next, as shown in FIG. 7B, the image display medium 100 is covered with first, second, and third thermoplastic members 201, 202, and 203, for example, a laminate using a heating roller (not shown). Using a method or the like, heating and pressurization are performed on both sides of the image display medium 100 under the same conditions.

  At this time, since the first reinforcing member 111 is present, the applied pressure is dispersed and does not concentrate on the portion of the first substrate 104 located immediately above the first gap portion 108.

  In addition, since the second reinforcing member 112 is present, the applied pressure is dispersed and does not concentrate on the portion of the second substrate 105 located immediately below the second gap portion 109.

  As a result, as shown in FIG. 7C, the portion of the first substrate 104 and the first thin film electrode 102 located immediately above the first gap 108, and the second substrate 105 and the second thin film The image display medium 100 whose surface is covered with the thermoplastic film 200 can be formed without a portion of the electrode 103 located immediately below the second gap 109 being deformed by pressure.

(Effect of the second embodiment)
According to the second embodiment, when the thermoplastic film 200 is thermocompression bonded to the image display medium 100, even if the front and back surfaces are heated and pressed under the same conditions, not in one direction, the image By forming the first and second reinforcing members 111 and 112 on the display medium 100, the damage to the first and second thin film electrodes 102 and 103 generated when the thermoplastic film 200 is thermocompression bonded is suppressed, It becomes possible to prevent disconnection.

  Further, the first and second thin film electrodes 102 are formed by forming both the first and second reinforcing members 111 and 112 so as to cover directly above and immediately below the first gap 108 and the second gap 109. , 103 and the first and second extraction electrodes 106 and 107, when the mechanical strength is increased and the image display medium 100 is bent and deformed, the disconnection or the like generated in the first and second thin film electrodes Damage can be prevented.

  The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. In addition, the constituent elements of the above embodiments can be arbitrarily combined without departing from the spirit of the invention.

(A), (b) is the top view and bottom view of the image display medium which concern on the 1st Embodiment of this invention. (A), (b) is sectional drawing of the image display medium based on the 1st Embodiment of this invention. 1 is an exploded perspective view of an image display medium according to a first embodiment of the present invention. (A)-(c) is sectional drawing which showed each manufacturing process of the image display medium based on the 1st Embodiment of this invention. (A), (b) is the top view and bottom view of the image display medium which concern on the 2nd Embodiment of this invention. (A), (b) is sectional drawing of the image display medium based on the 2nd Embodiment of this invention. (A)-(c) is sectional drawing which showed each manufacturing process of the image display medium based on the 2nd Embodiment of this invention. (A)-(b) is sectional drawing which showed each manufacturing process of the conventional image display medium.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image display medium 101 Display layer 102 1st thin film electrode 103 2nd thin film electrode 104 1st board | substrate 105 2nd board | substrate 106 1st extraction electrode 107 2nd extraction electrode 108 1st clearance gap 109 2nd Gap portion 110 Extraction hole 111 First reinforcing member 112 Second reinforcing member 113 IC chip 114 Damaged portion 200 Thermoplastic film 201 First thermoplastic member 202 Second thermoplastic member 203 Third thermoplastic member

Claims (7)

In an image display medium whose entire surface is covered with a thermoplastic film,
A display layer;
First and second substrates having first and second thin film electrodes disposed opposite to each other across the display layer;
First and second extraction electrodes formed on the surfaces of the first and second thin film electrodes for electrical connection with the outside;
A position straddling the second substrate and the first extraction electrode on the first substrate side, and a position straddling the first substrate and the second extraction electrode on the second substrate side And a reinforcing member formed on at least one of
An image display medium comprising:   The reinforcing member has a position straddling the second substrate on the first substrate side and the first extraction electrode, and the first substrate and the second extraction electrode on the second substrate side. The image display medium according to claim 1, wherein the image display medium is formed at both of the positions extending over the two. The reinforcing member formed at a position straddling the second substrate and the first extraction electrode on the first substrate side can straddle the first substrate and the second extraction electrode. Has such a size,
The reinforcing member formed at a position straddling the first substrate and the second extraction electrode on the second substrate side can straddle the second substrate and the first extraction electrode. The image display medium according to claim 1, wherein the image display medium has a size as described above. The reinforcing member formed at a position straddling the second substrate on the first substrate side and the first extraction electrode is formed on the surface of the first substrate,
The reinforcing member formed at a position straddling the first substrate and the second extraction electrode on the second substrate side is formed on the surface of the second substrate. 2. The image display medium according to 1. A reinforcing member formed at a position straddling the second substrate on the first substrate side and the first extraction electrode is formed inside the first substrate,
The reinforcing member formed at a position straddling the first substrate and the second extraction electrode on the second substrate side is formed inside the second substrate. The image display medium described in 1. In the method for producing an image display medium whose entire surface is covered with a thermoplastic film,
The first and second substrates having the first and second thin film electrodes are arranged opposite to each other with the display layer interposed therebetween, and the surface of the first and second thin film electrodes is electrically connected to the outside. A first step of forming first and second extraction electrodes;
A position straddling the second substrate and the first extraction electrode on the first substrate side, and a position straddling the first substrate and the second extraction electrode on the second substrate side And a second step of forming a reinforcing member on at least one of
A method for manufacturing an image display medium, comprising:   The second step includes a position straddling the second substrate on the first substrate side and the first extraction electrode, the first substrate on the second substrate side, and the second substrate. The method for manufacturing an image display medium according to claim 6, wherein the reinforcing member is formed at both of the positions extending over the extraction electrode.

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