JP2008116635A - Image display medium and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display medium in which the occurrence of short circuiting between electrodes is effectively prevented, the reliability of a display portion is high and the constitution is simple and inexpensive, and a method for manufacturing the same. <P>SOLUTION: The image display medium is constituted to include a first substrate laminate 1 formed with a first thin film electrode 1 having a high resistance portion 1d along top of a continuous line L connecting a point apart by a prescribed distance from a peripheral edge on a first substrate 1a, a second substrate laminate 2 arranged to face the first substrate laminate 1 and formed with a second thin film electrode 2b on a second substrate 2a, and a display layer 3 held between the first thin film electrode 1b of the first substrate laminate 1 and the second thin film electrode 2b of the second substrate laminate 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image display medium and a method for manufacturing the same, and more specifically, an image display medium having a simple and inexpensive structure with a highly reliable display portion in which occurrence of a short circuit between electrodes is effectively prevented and the manufacture thereof. Regarding the method.

  In recent years, in addition to paper media and electronic display devices as image display media, the contents of both have been combined, and the display contents are electrically rewritten among display media that have the advantages of paper and retain visibility and portability. An image display medium called “electronic paper” or “digital paper” that can be used is attracting attention. That is, cards (for example, commuter pass, examination ticket, membership card, ID card, cash card, credit card, merchandise distribution tag, etc.) having a non-contact IC represented by RFID (RF tag) are widely used. Accordingly, there has been a growing demand for rewritable display of characters, graphics, and the like on these cards, so that there is a great demand for “electronic paper” and the like.

Among these “electronic paper” technologies, high-definition display can be achieved in a short time with simple power supply means, and non-contact writing can be performed on the display surface. The optical writing type “electronic paper” technology that is expected to be applied is attracting attention (see Patent Document 1). In the case of “electronic paper” used for such an IC card, since the formation of the functional layer (display layer) is performed in the coating process, the cost can be reduced when continuous coating is performed. Since pattern formation requires an etching process consisting of photoresist application, exposure, development, and washing, continuous operation is difficult and cost reduction is difficult. As a cost reduction method, there is a method using a full-surface electrode that is not patterned as seen in a sheet-type inorganic EL device. However, since the driving voltage of “electronic paper” is relatively large, 300V to 400V, “electronic paper” When the distance between the electrodes on the end face from which the medium was cut was varied, a portion having a small distance between the electrodes (horizontal distance between the electrodes) could be short-circuited and discharged, resulting in damage.
JP 2005-18348 A

  The present invention has been made in view of the above-described background art. The occurrence of a short circuit between electrodes is effectively prevented, the reliability of a display portion is high, and an image display medium having a simple and inexpensive configuration and its efficiency. An object of the present invention is to provide a simple manufacturing method.

  In order to achieve the above object, according to the present invention, the following image display medium and a manufacturing method thereof are provided.

[1] A first substrate laminate in which a first thin film electrode having a high resistance portion is formed on a first substrate along a continuous line connecting points separated from a peripheral edge by a predetermined distance; A second substrate laminate in which a second thin film electrode is formed on a second substrate, opposite to the first substrate laminate, the first thin film electrode of the first substrate laminate, and the first substrate laminate An image display medium comprising: a display layer sandwiched between the second thin film electrodes of the two substrate laminates.

[2] The image display medium according to [1], wherein the first and second thin film electrodes are full surface electrodes formed on the entire surfaces of the first and second substrates.

[3] The high resistance portion of the first thin film electrode is formed along one or a plurality of continuous lines connecting points separated by a predetermined distance from the periphery of the first thin film electrode. The image display medium according to [1], wherein the image display medium is characterized.

[4] The high resistance portion of the first thin film electrode is a conductive fracture portion caused by a crack formed by bending the first thin film electrode. Image display medium.

[5] In the above [1], the high resistance portion in the first thin film electrode is a conductive fracture portion caused by thermal damage formed by laser processing on the first thin film electrode. The image display medium described.

[6] The image display medium according to [1], wherein the display layer includes a liquid crystal layer and a photoconductor layer.

[7] The above [1], further comprising first and second extraction electrodes connected to the surfaces of the first and second thin film electrodes for electrical connection with the outside. ] The image display medium as described in.

[8] The image display medium according to [1], further including a protective layer covering the entire surface.

[9] A first step of preparing a first substrate laminate in which a first thin film electrode is formed on a first substrate, and a point separated by a predetermined distance from the periphery of the first substrate laminate. A second step in which a high resistance portion is formed on the connected continuous line to make the first substrate laminate a high resistance laminate, and a second thin film electrode is formed on the second substrate. A third step of forming a display laminate by laminating a display layer on the second substrate laminate, and bonding the high-resistance laminate and the display laminate together. And a fourth step. A method for manufacturing an image display medium, comprising:

[10] In the second step, bending is performed along a continuous line connecting points separated from the periphery of the first substrate stack by a predetermined distance, and separated from the periphery of the first thin film electrode by a predetermined distance. The method for manufacturing an image display medium according to [9], wherein the high-resistance portion including a conductive breakage portion caused by a crack is formed along a continuous line connecting the spots.

[11] In the second step, a laser beam is irradiated on a continuous line connecting points separated by a predetermined distance from the periphery of the first substrate stack, and only a predetermined distance from the periphery of the first thin film electrode. The method for producing an image display medium according to [9], wherein the high-resistance portion including a conductive breakage portion caused by thermal damage is formed along a continuous line connecting remote points.

[12] The method for manufacturing an image display medium according to [9], wherein the first and second thin film electrodes are full surface electrodes formed on the entire surfaces of the first and second substrates. .

[13] The method for producing an image display medium according to [9], wherein the display layer includes a liquid crystal layer and a photoconductor layer.

[14] The method further includes a fifth step of connecting the first and second extraction electrodes for electrical connection to the outside to the surfaces of the first and second thin film electrodes. The method for producing an image display medium according to [9].

[15] The method for manufacturing an image display medium according to [9], further including a sixth step of forming a protective layer covering the whole.

  With the image display medium according to the first aspect of the present invention, the occurrence of a short circuit between the electrodes is effectively prevented, the reliability of the display portion is high, and a simple and inexpensive configuration is realized.

  In the case of the image display medium according to claim 2 of the present invention, the above-described effects are exhibited particularly effectively.

  With the image display medium according to claims 3 to 5 of the present invention, the above-described effects can be exhibited smoothly and reliably.

  The image display medium according to claims 6 to 7 of the present invention realizes an optical writing type “electronic paper” that exhibits the above-described effects.

  With the image display medium according to claim 8 of the present invention, the above-described effects can be exhibited more smoothly and reliably.

  According to the method for manufacturing an image display medium according to claim 9 of the present invention, the occurrence of a short circuit between the electrodes is effectively prevented, the reliability of the display portion is high, and an image display medium having a simple and inexpensive configuration is efficiently produced. Can be manufactured.

  By the method for manufacturing an image display medium according to claims 10 to 11 of the present invention, the above-described effects can be exhibited smoothly and reliably.

  In the case of the image display medium manufacturing method according to the twelfth aspect of the present invention, the above-described effects are exhibited particularly effectively.

  By the method for manufacturing an image display medium according to the thirteenth to fourteenth aspects of the present invention, an optical writing type “electronic paper” that exhibits the above-described effects can be efficiently manufactured.

  According to the image display medium manufacturing method of the fifteenth aspect of the present invention, the above-described effects can be exhibited more smoothly and reliably.

[First Embodiment]
(Configuration of image display medium)
1A and 1B show an image display medium according to a first embodiment of the present invention. FIG. 1A is a plan view, FIG. 1B is a cross-sectional view taken along line AA, and FIG. 1C is a cross-sectional view taken along line BB. is there. FIG. 2 is an exploded perspective view of the image display medium shown in FIG.

  As shown in FIGS. 1 and 2, the image display medium 10 according to the present embodiment has a high resistance portion along a continuous line L connecting points separated from the periphery by a predetermined distance on the first substrate 1a. The first thin film electrode 1b having the first thin film electrode 1b is formed, and the second thin film electrode 2b is formed on the second substrate 2a disposed opposite to the first thin film substrate 1 Display layer 3 sandwiched between the second substrate laminate 2 formed, the first thin film electrode 1b of the first substrate laminate 1 and the second thin film electrode 2b of the second substrate laminate 2 And a configuration provided with.

  In addition, the image display medium 10 of the present embodiment includes first and second extraction electrodes connected to the surfaces of the first and second thin film electrodes 1b and 2b for electrical connection with the outside. 1c and 2c are further provided. In FIGS. 1B and 1C, the display layer 3 is disposed on the second thin film electrode 2b side of the second substrate laminate 2, but the first layer of the first substrate laminate 1 is the first. It may be arranged on the thin film electrode 1b side. Moreover, you may arrange | position an adhesive bond layer between the display layer 3 and the 1st thin film electrode 1b or the 2nd thin film electrode 2b.

  Further, in the image display medium 10 of the present embodiment, as the first and second thin film electrodes 1b and 2b, full-surface electrodes formed on the entire surfaces of the first and second substrates 1a and 2a are used. .

  The image display medium 10 in the present embodiment is used as an IC card or the like to which a display function using “electronic paper” such as an optical writing type, a toner display type, and an electrophoretic method is added. Hereinafter, each component will be specifically described.

(Substrate laminate)
In the first substrate laminate 1, a first thin film electrode 1b having a high resistance portion 1d is formed on a first substrate 1a along a continuous line L connecting points separated from the periphery by a predetermined distance. Configured. The second substrate laminate 2 is configured by forming a second thin film electrode 2b on a second substrate 2a. A display layer 3 described later is sandwiched between the first thin film electrode 1b of the first substrate laminate 1 and the second thin film electrode 2b of the second substrate laminate 2.

  As the 1st and 2nd board | substrates 1a and 2a which comprise the 1st and 2nd board | substrate laminated bodies 1 and 2, at least one located in the display side, for example, the polyethylene terephthalate (PET) whose thickness is 25-200 micrometers And the like that are made of a transparent resin material.

  As the first and second thin film electrodes 1b and 2b constituting the first and second substrate laminates 1 and 2, at least one of them positioned on the display side is, for example, indium tin oxide (ITO) having a thickness of 50 to 350 nm. And a transparent electrode made of zinc oxide or the like.

  The high resistance portion 1d of the first thin film electrode 1b is not particularly limited as long as it can effectively prevent the occurrence of a short circuit between the electrodes. For example, the first thin film electrode 1b is bent. It can be mentioned that the portion is a conductive fracture due to a crack formed by the above.

  Further, as another example of such a high resistance portion 1d, it can be mentioned that the portion is a conductive fracture due to thermal damage formed by laser processing on the first thin film electrode 1b. As such laser processing, for example, a gas laser such as an excimer laser or a carbon dioxide laser, or a solid laser such as a YAG laser or a semiconductor laser can be used.

  As described above, in the present embodiment, the first and second thin film electrodes 1b and 2b are both configured to have the form of full-surface electrodes, but depending on the type of the image display medium, for example, Is a full surface electrode, the other is a pixel electrode, one is a plurality of scan electrodes, the other is a plurality of signal electrodes perpendicular to the scan electrodes, one is a plurality of scan electrodes, and the other moves in the longitudinal direction on the scan electrodes It may have a form of a plurality of individual electrodes to be scanned, one of which is a plurality of signal electrodes, and the other of which is a form of a plurality of individual electrodes which are scanned by moving in the longitudinal direction on the signal electrode. Further, when the first and second thin film electrodes 1b and 2b are composed of a plurality of electrodes such as row electrodes and column electrodes, etc., when there are a plurality of extraction electrodes 1c and 2c described later, the first and second thin film electrodes 1b and 2b The extraction electrodes 5a and 5b are composed of electrode groups corresponding to the first and second thin film electrodes 1b and 2b, respectively.

(Display layer)
As the display layer 3, although it changes with kinds of the image display medium 10, what consists of a layer which has a liquid crystal, a colored particle, etc. can be mentioned, for example. In the case where the image display medium 10 is an optical writing type “electronic paper”, a liquid crystal layer and a photoconductor layer may be included. Specific examples of such a display layer 3 include, for example, a liquid crystal layer whose reflectance (transmittance) changes according to an applied voltage, a light absorption layer that absorbs light, and a resistance value that is reduced by light irradiation. Examples thereof include a structure in which a photoconductor layer is laminated in order from the display surface side, or a structure in which a light absorption layer, a photoconductor layer, an isolation layer, and a liquid crystal layer are laminated in order from the display surface side. Note that examples of the liquid crystal layer include a polymer dispersed liquid crystal and a microencapsulated liquid crystal (for example, a liquid crystal layer configured to have a microcapsule in which a cholesteric liquid crystal is encapsulated). Examples of the photoconductor layer may include a charge transport layer and a pair of charge generation layers stacked on both sides of the charge transport layer. Thus, an alternating voltage can be applied to the liquid crystal layer, so that deterioration of the liquid crystal layer can be suppressed, and the driving voltage can be lowered and the lifetime of the electronic paper can be increased. Further, as the display layer 3, in addition to the above, a microencapsulated electrophoretic element, a gyricon element, and the like can be given. Examples of the bonding between the display layer 3 and the thin-film electrodes 1b and 2b include bonding by coating or pressure bonding.

(Adhesive layer)
In order to improve the bondability between the display layer 3 and the thin film electrodes 1b and 2b, an adhesive layer (not shown) may be disposed. Examples of such an adhesive layer include acrylic and urethane adhesives and pressure-sensitive adhesives. The thickness of the adhesive layer is preferably 1 to 8 μm, for example.

(Extraction electrode)
The first and second extraction electrodes 1c and 2c are made of a metal such as Ni having a thickness of 50 to 200 μm, for example, and have higher rigidity or hardness than the first and second thin film electrodes 1b and 2b. It is preferable.

(Protective layer)
In the present embodiment, although not shown, it is preferable to further include a protective layer covering the whole. As such a protective layer, for example, a thermoplastic film made of a transparent thermoplastic resin using PET (polyethylene terephthalate), amorphous PET (PET-G), polyvinyl chloride, polyester, or a combination thereof. Can be mentioned. Such a thermoplastic film is formed, for example, by thermocompression bonding a thermoplastic member to the surface of the image display medium 10 using a bonding tool. In this case, it is preferable to have an extraction hole for connecting to the first and second extraction electrodes 1c and 2c from the outside. In order to prevent wear of the extraction hole, a metal pipe such as Ni or stainless steel is fitted into the extraction hole, and the first and second extraction electrodes 1c and 2c are wired in the metal pipe. It may be.

(IC chip)
In this embodiment mode, although not illustrated, an IC chip such as a wireless tag may be mounted in a predetermined area as necessary.

(Production of image display medium)
FIG. 3 is an explanatory view showing the manufacturing process of the image display medium according to the first embodiment of the present invention in the order of steps, (a) shows the first step of preparing the first substrate laminate, (B) shows a state before bending in the second step in which the high resistance portion is formed by bending and the first substrate laminate is made into a high resistance laminate, and (c) is in the second step. The state after bending is shown, (d) shows the third step of forming the display laminate by laminating the display layer on the second substrate laminate, and (e) shows the high resistance laminate and the display. The 4th process of bonding a laminated body is shown.

(First step)
As shown in FIG. 3A, a first substrate laminate 1 is prepared in which a first thin film electrode 1b is formed on a first substrate 1a. Specifically, the first thin film electrode 1b is formed on the entire surface of the first substrate 1a, and is punched into a planar shape shown in FIG.

(Second step)
As shown in FIGS. 3B and 3C, the first thin-film electrode 1b is reliably formed with an electrically disconnected portion (high resistance portion 1d (see FIGS. 1A and 3E)). In order to achieve this, a male mold 4a and a female mold 4b are used, and the first substrate stack 1 (the first substrate 1a and the first thin film electrode 1b) is disposed between the male mold 4a and the female mold 4b. Bending by pressurization is performed so that it is 10 mm or less, preferably 3 mm or less. In this way, the high resistance portion 1d is formed on the continuous line L connecting the points separated from the peripheral edge of the first substrate laminate 1 by the predetermined distance D, and the first substrate laminate 1 is formed into the high resistance laminate. It can be the body S1. In this case, the high resistance portion 1d along one continuous line L (see FIG. 1A) can be formed. FIG. 3B shows a case where the first thin film electrode 1b is bent from the first substrate 1a side, but conversely, the first thin film electrode is formed from the first substrate 1a side. You may bend to the 1b side.

(Third step)
As shown in FIG. 3D, a second substrate laminate 2 in which a second thin film electrode 2b is formed on a second substrate 2a is prepared, and a display layer is provided on the second substrate laminate 2. 3 is laminated to form a display laminate S2. Specifically, the second substrate laminate 2 is formed by coating the entire surface of the second thin film electrode 2b on the second substrate 2a, and then the display layer 3 is continuously applied on the second thin film electrode 2b. And then punched into the planar shape shown in FIG. 1A to form the second display laminate S2.

(Fourth process)
As shown in FIG. 3 (e), the high resistance laminate S1 and the display laminate S2 are bonded together. In this case, for example, a heating tool (for example, 80 to 150 ° C.) is applied to the entire high resistance laminated body S1 and display laminated body S2 fixed on the stand by using a bonding tool and sandwiching a cushioning material from above. Bonding can be performed by applying pressure (for example, 0.3 MPa or more). Further, for example, heating and pressurization may be performed under the same conditions from both the front and back surfaces of the high resistance laminate S1 and the display laminate S2 by using a laminating method using a heating roller. Moreover, you may use an adhesive agent for a joint surface.

(Fifth step)
Next, first and second extraction electrodes 1c and 2c (see FIG. 1A) for electrical connection with the outside are connected to the surfaces of the first and second thin film electrodes 1b and 2b. To do.

(Sixth step)
Next, if necessary, an IC chip such as a wireless tag is mounted and a protective layer covering the whole is formed.

  In this way, it is possible to obtain the image display medium 10 in which the high resistance portion 1d is formed on the first thin film electrode 1b and which is not easily short-circuited. Moreover, since the method of this embodiment does not require patterning, the image display medium 10 can be manufactured at low cost.

[Second Embodiment]
(Configuration of image display medium)
4A and 4B show an image display medium according to a second embodiment of the present invention, where FIG. 4A is a plan view, FIG. 4B is a cross-sectional view taken along line EE, and FIG. 4C is a cross-sectional view taken along line FF. is there.

  As shown in FIG. 4, the basic configuration of the image display medium 10 according to the second embodiment is the same as that of the first embodiment shown in FIG. 1, but the second embodiment. In the case of the image display medium 10 according to the above, the high resistance portion 1d along the three continuous lines (L1, L2, L3) is formed, and the short circuit can be surely prevented.

  FIGS. 5A and 5B are cross-sectional views illustrating a part of the method for manufacturing the image display medium 10 according to the second embodiment, in which FIG. 5A is a state before pressurization during bending, and FIG. 5B is during pressurization. A state and (c) show the state after pressurization, respectively. The bending process shown in FIG. 5 is basically the same as the bending process shown in FIGS. 3B and 3C. However, the number of bent portions is increased, and three continuous lines (L1, L2,. The high resistance portion 1d along L3) is formed (see FIGS. 4A and 4C).

  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-described embodiments may be arbitrarily combined within a scope that does not depart from the spirit of the invention.

  The image display medium of the present invention can be used as an RFID (RF tag) as an application such as “electronic paper” or “digital paper” that can maintain the visibility and portability and can electrically rewrite display contents. Cards (for example, commuter pass, examination ticket, membership card, ID card, cash card, credit card, merchandise distribution tag, etc.) and information media (eg, books, electronic newspapers, etc.) equipped with representative non-contact ICs For example, transportation industry, medical industry, financial industry, distribution industry, publishing industry, information transmission industry, electronic equipment manufacturing industry, tourism industry, entertainment industry, etc.

The image display medium which concerns on the 1st Embodiment of this invention is shown, (a) is a top view, (b) is an AA sectional view, (c) is a BB sectional drawing. It is a disassembled perspective view of the image display medium shown in FIG. It is explanatory drawing which shows the manufacturing process of the image display medium based on the 1st Embodiment of this invention in order of a process, (a) shows the 1st process of preparing a 1st board | substrate laminated body, (b) is bending. In the second step of forming a high resistance portion by processing and making the first substrate laminate a high resistance laminate, the state before folding is shown. (C) shows the state after bending in the second step. (D) shows a third step of forming the display laminate by laminating the display layer on the second substrate laminate, and (e) is a step of attaching the high resistance laminate and the display laminate. The 4th process to match is shown. The image display medium which concerns on the 2nd Embodiment of this invention is shown, (a) is a top view, (b) is EE sectional view taken on the line, (c) is FF sectional view taken on the line. It is sectional drawing which shows a part of manufacturing method of the image display medium concerning the 2nd Embodiment of this invention, (a) is the state before the pressurization in a bending process, (b) is the state under pressurization, ( c) shows the state after pressurization.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st board | substrate laminated body 1a 1st board | substrate 1b 1st thin film electrode 1c 1st extraction electrode 1d High resistance part 2 2nd board | substrate laminated body 2a 2nd board | substrate 2b 2nd thin film electrode 2c 2nd Extraction electrode 3 Display layer 4a Male mold 4b Female mold 10 Image display medium D Distance from the periphery of the first thin film electrode L Continuous line L1 to L3 Continuous line P Pressure S1 High resistance laminate S2 Display laminate

Claims (14)

A first substrate laminate in which a first thin film electrode having a high resistance portion is formed on a first substrate along a continuous line connecting points separated from the periphery by a predetermined distance;
A second substrate laminate in which a second thin film electrode is formed on a second substrate disposed opposite to the first substrate laminate;
A display layer sandwiched between a first thin film electrode of the first substrate stack and a second thin film electrode of the second substrate stack;
An image display medium comprising:   The image display medium according to claim 1, wherein the first and second thin film electrodes are full surface electrodes formed on the entire surfaces of the first and second substrates.   The high resistance portion of the first thin film electrode is formed along one or a plurality of continuous lines connecting points separated by a predetermined distance from the periphery of the first thin film electrode. The image display medium according to claim 1.   2. The image display medium according to claim 1, wherein the high resistance portion of the first thin film electrode is a conductive break portion caused by a crack formed by bending the first thin film electrode.   2. The image display according to claim 1, wherein the high resistance portion of the first thin film electrode is a conductive break portion caused by thermal damage formed by laser processing on the first thin film electrode. Medium.   The image display medium according to claim 1, wherein the display layer includes a liquid crystal layer and a photoconductor layer.   The first and second extraction electrodes connected to the surfaces of the first and second thin film electrodes for electrical connection with the outside are further provided. Image display medium.   The image display medium according to claim 1, further comprising a protective layer covering the whole. A first step of preparing a first substrate laminate in which a first thin film electrode is formed on a first substrate;
A second step of forming a high resistance portion on a continuous line connecting points separated by a predetermined distance from the periphery of the first substrate stack, and making the first substrate stack a high resistance stack;
A second substrate laminate in which a second thin film electrode is formed on a second substrate is prepared, and a display layer is laminated on the second substrate laminate to form a display laminate. Process,
A method for producing an image display medium, comprising: a fourth step of bonding the high-resistance laminate and the display laminate.   In the second step, a point separated by a predetermined distance from the periphery of the first thin film electrode is bent along a continuous line connecting points separated by a predetermined distance from the periphery of the first substrate stack. The method for manufacturing an image display medium according to claim 9, wherein the high resistance portion including a conductive breakage portion caused by a crack is formed along the connected continuous line.   In the second step, a laser beam is irradiated on a continuous line connecting points separated by a predetermined distance from the periphery of the first substrate stack, and a point separated by a predetermined distance from the periphery of the first thin film electrode. The method of manufacturing an image display medium according to claim 9, wherein the high resistance portion including a conductive fracture portion caused by thermal damage is formed along a continuous line connecting the two. The method for manufacturing an image display medium according to claim 9, wherein the first and second thin film electrodes are full surface electrodes formed on the entire surfaces of the first and second substrates.
The method for manufacturing an image display medium according to claim 9, wherein the display layer includes a liquid crystal layer and a photoconductor layer.   10. The method according to claim 9, further comprising a fifth step of connecting first and second extraction electrodes for electrical connection to the outside to the surfaces of the first and second thin film electrodes. The manufacturing method of the image display medium as described in 2.   The method for producing an image display medium according to claim 9, further comprising a sixth step of forming a protective layer covering the whole.

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