JP2009098319A - Information display device and printer using this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display medium, a photoprint device and an electrophoretic display device capable of increasing flexibility of an EPD display medium and reducing cost easily. <P>SOLUTION: A first substrate 11 and a second substrate 12, at least one of which has light transparency, are disposed facing each other. The first substrate 11 comprising an integrated resin film formed by arranging a multiplicity of cells 13. Each cell 13 is opened on one surface side, and sectioned by a partition 11a, and has a bottomed structure with the other surface side constituting the bottom part 11b of the substrate. Dispersion liquid 16 consisting of charged particles 14, insulation liquid 15, etc. are filled in each cell 13. A transparent electrode layer 17 is arranged in such a manner that it contacts the surface of the dispersion liquid 16 and seals them in all the cells 13. A display pattern is formed in a display medium 10 by the photoprint device provided with a first electrode member and a second electrode member that press the first substrate 11 and the second substrate 12 from their surface side respectively. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display medium, a printing apparatus, and an electrophoretic display apparatus that are used for display of an display (EPD) system using an electrophoretic phenomenon.

  Currently, various display technologies have been developed in response to information technology. For example, liquid crystal display devices, plasma display devices composed of so-called PDPs (plasma display panels), and FPD (flat panel display) devices such as organic EL display devices. Has been put to practical use. In addition, many studies have been made so far on display technologies related to EPD (ElectroPhoresis Display) using electrophoretic phenomenon, and various electrophoretic panels or electrophoretic display devices have been proposed (for example, Patent Document 1, Patent Document 1). 2). In this EPD device, it is easy to reduce the thickness as compared with the FPD device, and because of its memory function, electronic paper with a thin electrophoretic panel has been proposed (for example, Patent Document 3, Patent Document 3). 4).

  An example of such electronic paper will be described with reference to FIG. FIG. 10 is a partially enlarged sectional view thereof. In the electronic paper 100, the first substrate 101 and the second substrate 102 are disposed to face each other. Here, the first substrate 101 and the second substrate 102 are made of, for example, a PET (polyethylene terephthalate) sheet. A required number of pixels are arranged in a matrix between the first substrate 101 and the second substrate 102.

  In these pixels, TFTs (thin film transistors) serving as switching elements for so-called active matrix display and pixel electrodes connected to the TFTs are formed in a TFT layer 103 (not shown in detail). A resin layer 104 for planarizing the surface is formed on the TFT layer 103, and a pixel cell 106 partitioned by a partition wall 105 is formed. Here, each cell 106 is filled with a dispersion liquid 109 made of an insulating liquid 108 in which charged particles 107 are dispersed. A counter electrode 110 having optical transparency such as ITO (indium tin oxide) or ZnO (zinc oxide) is disposed so as to be in contact with the surface of the dispersion 109 and sealed in the cell 106. The counter electrode 110 is formed over the entire surface of the second substrate 102 as a common electrode for each pixel.

  In such an electronic paper 100, the charged particles 107 and the insulating liquid 108 are colored differently. For example, the positively charged charged particles 107 are white, and the insulating liquid 108 is colored black, blue, red or green. Two types of voltages having different polarities can be switched and applied between the pixel electrode of each pixel formed in the TFT layer 103 and the counter electrode 110.

In the display of the electronic paper 100, the charged particles 107 are aggregated on the side of the counter electrode 110 close to the observer, for example, by applying a voltage having the counter electrode 110 as a negative electrode and the pixel electrode as a positive electrode. For example, white is visually recognized. On the other hand, by applying a voltage with the counter electrode 110 as the positive electrode and the pixel electrode as the negative electrode, the charged particles 107 are aggregated on the resin layer 104 side far from the observer, and in this state, the observer changes the black color of the insulating liquid 108, for example. You will see. Thus, by electrically polarizing the dispersion 109 in the cell 106, two types of colors corresponding to the direction in which the voltage is applied are displayed. When the voltage application is stopped, the charged particles 107 remain agglomerated in the cell 106, the display pattern is stored in memory, and an electronic paper using an EPD display is realized.
JP 59-34518 JP-A-2-284125 JP 2002-169190 A JP 2006-202030 A

  However, the conventional electronic paper has a problem in that it is difficult to reduce the cost because a pixel electrode for applying a voltage to each pixel that performs display in the EPD system is formed by the TFT. The thickness of such electronic paper as a whole is limited to about 0.1 mm to 0.2 mm, and a large number of TFTs are formed in a matrix on the entire surface, so that its flexibility exceeds a certain limit. It was difficult to increase. For this reason, for example, it has been difficult to realize a display medium having flexibility similar to that of recording paper having a thickness of less than 100 μm.

  The present invention has been made in view of the above-described circumstances, and improves the flexibility of an EPD display medium as compared with the conventional display medium, and facilitates cost reduction, a printing apparatus, and an electrophoretic display apparatus. The purpose is to provide.

In order to achieve the above object, a display medium according to a first invention includes a first substrate and a second substrate, at least one of which is light transmissive and disposed opposite to each other, and the first substrate. A sheet-like display medium having an insulating liquid and a plurality of cells in which charged particles dispersed in the insulating liquid are enclosed. A display pattern is formed by an electric field selectively applied from the outside through one substrate.
Furthermore, it is preferable that an electrode layer is formed on one surface of the second substrate, and an electric field is applied from the outside through the first substrate.

A printing apparatus according to a second aspect of the invention includes a first substrate and a second substrate, at least one of which is light transmissive and disposed opposite to each other, and between the first substrate and the second substrate. A sheet-like display medium having an insulating liquid and a plurality of cells in which charged particles dispersed in the insulating liquid are enclosed, and the surface of the first substrate and the first A first electrode member and a second electrode member which are in contact with each other from the surface of the second substrate, and a voltage is applied between the first electrode member and the second electrode member to generate an electric field in the cell. By doing so, the charged particles are moved in the cell, and a display pattern is printed on the display medium.
When the second substrate of the display medium has an electrode layer, a voltage is applied between the electrode layer and the first electrode member in contact with the surface of the first substrate to generate an electric field in the cell.

  An electrophoretic display device according to a third aspect of the present invention includes a first substrate and a second substrate, at least one of which is light transmissive and disposed to face each other, the first substrate, and the second substrate. A sheet-like display medium having an insulating liquid and a plurality of cells enclosing charged particles dispersed in the insulating liquid, and the sheet-like display medium with respect to the sheet-like display medium A first electrode member and a second electrode member which are in contact with the surface of the first substrate and the surface of the second substrate, respectively, and a voltage is applied between the first electrode member and the second electrode member; And a printing device that prints a display pattern on the display medium by moving the charged particles in the cell by generating an electric field in the cell.

  According to the configuration of the present invention, the EPD display medium is increased in flexibility and has the same flexibility as recording paper. Further, it is possible to provide a display medium, a printing apparatus, and an electrophoretic display apparatus that can be easily reduced in cost.

Preferred embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or similar parts are denoted by the same reference numerals, and a part of the overlapping description is omitted. However, the drawings are schematic and ratios of dimensions and the like are different from actual ones.
(Display medium)
First, an EPD display medium according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing an example of the display medium.

  As shown in FIG. 1, in the display medium 10, the 1st board | substrate 11 and the 2nd board | substrate 12 are arrange | positioned facing each other. The first substrate 11 is made of an integral resin film in which a large number of cells 13 are arranged in a matrix, for example. Here, each cell 13 has a bottomed structure in which one surface side of the film-shaped resin is opened and partitioned from each other by the partition wall 11a, and the other surface side of the film-shaped resin is the substrate bottom portion 11b. The opening has a square shape, a circular shape, a honeycomb shape, or the like.

  Each cell 13 is filled with a dispersion liquid 16 composed of, for example, an insulating liquid 15 in which positively charged charged particles 14 are dispersed, as described in the prior art. A transparent electrode layer 17 having light transmissivity, such as ITO, is disposed so as to be in contact with the surface of the dispersion 16 and sealed in all the cells 13. The transparent electrode layer 17 is formed over the entire surface of the second substrate 12 as a common electrode for each pixel.

  In the sheet-like display medium 10, the charged particles 14 and the insulating liquid 15 are colored differently. For example, the charged particles 14 are white, and the insulating liquid 15 is black, blue, red or green.

  Here, a plurality of types of charged particles 14 may be mixed in the dispersion liquid 16. Further, in the display medium 10, it is sufficient that the display pattern can be visually recognized from either the first substrate 11 or the second substrate 12, so that either the first substrate 11 or the second substrate 12 has light transmittance. It only has to be. In addition, as long as the 1st board | substrate 11 has a light transmittance, the said transparent electrode layer 17 may be replaced by the opaque electrode layer.

(Display medium manufacturing method)
Next, a method for manufacturing the display medium 10 will be described with reference to FIG. FIG. 2 is a cross-sectional view of main manufacturing steps showing an example of the manufacturing method.

  In manufacturing the display medium 10, first, a UV (ultraviolet light) epoxy resin film having a film thickness of, for example, about 50 μm and being in a semi-cured state is prepared. And an embossing is given with respect to this epoxy resin film, and many recessed parts are formed. Thereafter, the embossed epoxy resin film is cured by UV irradiation. In this way, as shown in FIG. 2A, a large number of cells 13 each having a partition wall 11a and a substrate bottom 11b and configured by the recesses are arranged in a matrix, for example, having a thickness of about 50 μm. The first substrate 11 is formed. Here, each cell 13 has a structure in which the shape of the opening is, for example, a square having a side of about 50 μm and arranged at a pitch of about 60 μm.

  Subsequently, as illustrated in FIG. 2B, the dispersion liquid 16 in which the charged particles 14 are dispersed in the insulating fluid 15 is filled in all the cells 13 of the first substrate 11. Note that a surfactant, a charge control agent, a viscosity modifier, and the like can be appropriately added to the dispersion liquid 16.

  Here, examples of suitable charged particles 14 include spherical titanium oxide. In addition, various organic or inorganic pigment particles can be used. For example, calcium carbonate, barium sulfate, gypsum, chromium oxide, manganese violet, carbon black, iron black, and bitumen, ultramarine blue, and phthalocyanine blue can be used. These materials are appropriately treated and dispersed in the insulating liquid 15.

  As the insulating fluid 15, first, a solvent that can be mixed with the insulating liquid 15 in which the charged particles 14 are dispersed may be selected, and a material in which various dyes that can be dissolved in the solvent are dissolved may be used. As the solvent, organic solvents such as m-xylene, ethylene glycol, dodecylbenzene, hexylbenzene, or silicone oil can be preferably used.

  Subsequently, as shown in FIG. 2C, the second substrate 12 made of a PET film having a light-transmitting transparent electrode layer 17 formed on one surface and a film thickness of about 30 μm to 40 μm is attached to the first substrate 11. The transparent electrode layer 17 is bonded to the upper end surface of the partition wall 11a with an adhesive. Here, the transparent electrode layer 17 is made of, for example, an ITO film having a film thickness of about 200 nm, contacts the surface of the dispersion 16, and encloses the dispersion 16 in all the cells 13.

  The display medium of the present embodiment is manufactured through the steps as described above. Here, the thickness of the display medium 10 can be made very easily less than 100 μm. In the above manufacturing method, the thickness can be about 80 μm, and a thickness equivalent to that of a normal recording sheet can be achieved.

  Further, in the display medium of this embodiment, since the TFT that becomes the pixel electrode is not formed at all, it is easy to reduce the cost. And since the TFT does not exist with the reduction of the thickness, it becomes extremely easy to increase the flexibility of the display medium, and it is possible to provide the same flexibility as, for example, recording paper used in various printers. Become.

  In the production of the display medium 10, a photosensitive polyimide resin film is formed on a PET film having a film thickness of, for example, 10 μm as the first substrate 11, and the photosensitive polyimide resin film is processed using a known photolithography technique to form partition walls. The cells 13 that are formed and separated from each other by the partition walls may be formed. In this case, the first substrate 11 is formed by the PET film and the partition walls made of polyimide.

  Next, another example of the display medium for EPD according to the embodiment of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view showing two modified examples of the display medium for EPD. The display medium for EPD shown in FIG. 3A has the same structure as the display medium 10 except that the transparent electrode layer 17 is deleted from the display medium 10 described above. In this display medium, the first substrate 11 and the second substrate 12 are bonded with the cell 13 interposed therebetween.

  In the EPD display medium of FIG. 3A, since the transparent electrode layer 17 is not provided, the thickness is reduced as compared with the display medium 10, and the flexibility is further enhanced as compared with the display medium 10.

  Further, the EPD display medium shown in FIG. 3B has a structure in which the vertical relationship between the second substrate 12 and the transparent electrode layer 17 in the above-described display medium 10 is reversed. That is, the first substrate 11 and the second substrate 12 are joined with the cell 13 interposed therebetween, and the transparent electrode layer 17 is formed on the upper surface of the second substrate 12.

  In the EPD display medium of FIG. 3B, since the transparent electrode layer 17 is on the upper surface of the second substrate 12, the second electrode member is electrically connected to the transparent electrode layer 17 as described later. In addition, the applied voltage for forming the display pattern on the display medium can be reduced more easily than in the case of the display medium 10.

  The manufacturing method of the display medium for EPD in FIG. 3A or 3B is the same as the manufacturing method of the display medium 10 shown in FIG. 2 except for the process of FIG. In these cases, in the step shown in FIG. 2C, the second substrate 12 made of, for example, a PET film without the transparent electrode layer 17 or the second substrate 12 having the transparent electrode layer 17 on the upper surface is used as the first substrate. 11, the lower surface of the second substrate 12 is bonded to the upper end surface of the partition wall 11a by an adhesive.

(Display media printing device)
Next, an example of a display medium printing apparatus according to an embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a schematic configuration diagram showing an example of the printing apparatus. FIG. 5 is a schematic top view showing an example of a printing head used in the printing apparatus, and FIG. 6 is an enlarged cross-sectional view taken along the line XX in FIG. FIG. 7 is a schematic diagram for explaining the printing operation of the display medium by the printing apparatus of this embodiment.

  As shown in FIG. 4, the printing apparatus 20 includes a printing head 21, a printing control unit 22, a conveyance roller 23, and guide rollers 24 and 24 as main components. Here, the print head 21 serving as the first electrode member is fixedly attached, and the print electrode side of the print electrode substrate portion 26A formed on the support substrate 25 of the print head 21, which will be described in detail later, is directed upward. It arrange | positions so that the medium 10 may be pressed. And the conveyance roller 23 used as the 2nd electrode member is arrange | positioned in the position which faces this printing electrode side. Here, the display medium 10 is conveyed while being pressed or in contact with the surface of the printing electrode substrate portion 26 </ b> A of the printing head 21 by the conveying roller 23. In addition, in order to selectively apply an electric field from the outside to the display medium, a print control unit 22 that transmits voltage pulses is connected to the drive circuit board unit 26B of the print head 21.

  The display medium 10 is transported or pumped in the transport direction 27b, which is the sub-scanning direction, with the transport rotation 27a of the transport roller 23 that is rotationally driven by a drive motor (not shown). Here, the display medium 10 is in the form of a sheet such as the recording paper as described above, and the materials and sizes of the various rollers are set in accordance with the sizes thereof.

  The conveyance roller 23 is made of a curved conductor such as a cylinder or a cylinder, or an insulator, and is movable in the vertical direction. The conveyance roller 23 is urged in a direction in pressure contact with the printing head 21 by a spring (not shown). The transport roller 23 has a cushioning property for pressing the display medium 10 against the print electrode of the print head 21. When the transport roller 23 is made of an insulator, the surface thereof is covered with a conductive material having an appropriate hardness. Yes.

  The guide roller 24 guides the display medium 10 in the transport direction 27b and enables its stable transport. The guide roller 24 is also urged so as to be movable in the vertical direction by a spring (not shown).

(Print head)
As shown in FIGS. 5 and 6, in the print head 21, the print electrode substrate portion 26 </ b> A and the drive circuit substrate portion 26 </ b> B are provided adjacent to each other on the main surface of the support substrate 25.

The print electrode substrate portion 26A is composed of an insulating substrate 31 such as Al ₂ O ₃ (alumina), and a base insulating layer 32 having a protruding portion 32a having a convex cross section is formed on the surface of the insulating substrate 31. A large number of strip-shaped printing electrodes 33 are formed so as to cover at least the protrusions 32 a on the base insulating layer 32. As shown in FIG. 5, the print electrodes 33 are arranged in a line as a predetermined number, for example, 2056 print electrode arrays in the main scanning direction of the print head.

  A protective layer 34 made of an insulating material that covers the print electrodes 33 arranged as the print electrode array is provided.

  On the other hand, the drive circuit board portion 26B includes a drive circuit board 35 and the like, a circuit pattern (not shown) and the like are formed on the surface of the board, and a drive IC 36 and the like are mounted. Then, the bonding wires W are electrically connected between the printing electrode 33 of the printing electrode board portion 26A and the driving IC 36 of the driving circuit board portion 26B and between the driving IC 36 and the circuit pattern of the driving circuit board portion 26B. Has been. These bonding wires W and driving ICs 36 are hermetically sealed with a sealing material 37 made of, for example, a mold resin. Here, the sealing material 37 is omitted from FIG. 5 for the purpose of clarifying the drawing.

  The drive circuit board portion 26B is preferably formed at a position where the apex of the sealing material 37 is lower than the surface of the protective layer 34 of the printing electrode substrate portion 26A with respect to the main surface of the support substrate 25.

  In the printing head 10, the support substrate 25 is made of, for example, Al (aluminum) metal, and the insulating substrate 31 is usually made of an insulating material having heat resistance. In addition to alumina ceramics, silicon, quartz, silicon carbide, or the like is used. You may be comprised with ceramics.

The base insulating layer 32 may be an insulator material. For example, it is made of a glass film made of SiO ₂ (silicon oxide) or a polyimide resin. Here, the protrusion 32a having a convex cross section has a height of about 50 μm, for example, and extends in the main scanning direction of the print head 21 in a band shape with a width of about 30 μm to 100 μm.

  The printing electrode 33 is mainly composed of a metal such as Al, Cu (copper), an AlCu alloy, or a refractory metal such as W (tungsten) or Mo (molybdenum). The printing electrode 33 is formed in a strip shape with a width of 30 μm to 100 μm, for example.

The protective layer 34 is made of a hard and dense insulator material such as SiON (silicon oxynitride), Si ₃ N ₄ (silicon nitride), or SiC (silicon carbide). The protective layer 34 has a function of covering the printing electrode 33 and protecting it from abrasion due to pressure contact or sliding contact of the display medium 10 and corrosion due to contact with moisture contained in the atmosphere.

(Print head manufacturing method)
Next, the production of the printing head 21 will be described. First, on the surface of an elongated insulating substrate 31 made of Al ₂ O ₃ ceramics, for example, a glass paste obtained by adding and mixing a suitable organic solvent and solvent to SiO ₂ glass powder is applied and formed by a well-known screen printing method. To do. Then, the base insulating layer 32 made of a glass film having a thickness of, for example, 100 μm is deposited on the surface of the insulating substrate 31 by firing at a predetermined temperature. And the protrusion part 32a of a strip | belt-shaped putter is formed with the width | variety of about 30 micrometers-about 100 micrometers by the photoengraving process, for example. Here, when the band-like pattern width becomes wide, it may be formed only by a screen printing method of glass paste and firing thereof. In this case, only the protrusion 32 a is formed on the insulating substrate 31 so as to extend in the main scanning direction of the printing head 21.

  Next, an Al film or an AlCu alloy film having a film thickness of, for example, about 0.5 μm is formed by, for example, a sputtering method so as to cover the base insulating layer 32 and the protrusions 32a, and printing is performed by a photoengraving process. The electrode 33 is formed by patterning. Alternatively, the patterned printing electrode 33 may be formed by sputtering an Al film or an AlCu alloy film using a mask jig (shadow mask).

  Thereafter, a protective layer 34 that covers the entire surface is formed by sputtering using a shadow mask. Here, the protective layer 34 is made of, for example, a SiON film having a thickness of about 1 μm to 2 μm. In this way, the print electrode substrate portion 26A is formed.

  Next, the printing electrode substrate portion 26A and the drive circuit substrate portion 26B in which, for example, a bare chip drive IC 36 is incorporated in advance are placed and fixed on the support substrate 25 made of an aluminum plate or the like via an adhesive. All the print electrodes 33 are electrically connected to the bonding pads on the output side of the drive IC 36 by bonding wires W made of, for example, Al wires or Au wires. Further, the bonding pads on the input side of the driving IC 36 are electrically connected to the circuit pattern of the driving circuit board 35 by bonding wires W. Finally, the driving IC 36 and the bonding wire W are hermetically sealed with the sealing material 37 by a known mounting technique. In this way, the printing head 21 of this embodiment is completed.

  Next, an example of the display medium printing operation by the above-described printing apparatus 20 will be described. The sheet-like display medium 10 is guided by the guide rollers 24 and 24 so as to be sandwiched between the printing head 21 and the conveying roller 23. Here, based on the print data transmitted from the print control unit 22 and given in time series, the print voltage pulse is transmitted to the print electrode array including the print electrodes 33. Then, printed images such as characters and figures are formed by the printing electrodes 33 of the printing electrode array. In this way, for example, an information display pattern is formed on the display medium 10.

  Specifically, as shown in FIG. 7, the display medium 10 is sandwiched between the surface of the transport roller 23 and the surface of the printing electrode substrate portion 26 </ b> A in the printing head 21. Here, a conductor layer 23a is formed on at least the outer peripheral surface of the transport roller 23, and contacts and presses the surface of the second substrate 12 of the display medium 10 over a wide area. The transport roller 23 or the conductor layer 23a is fixed to the ground potential. In addition, the printing electrode 33 contacts and presses the surface of the first substrate 11 of the display medium 10 via the protective layer 34 on the printing electrode substrate portion 26A.

  Then, a printing voltage pulse is transmitted from the printing control unit 33 to the printing electrode 33. When the printing voltage pulse is a positive voltage of 15V or 30V generated from the voltage source 38a, for example, it is generated in the cell 13 of the display medium 10 with the conductive layer 23a as the negative electrode and the printing electrode 33 as the positive electrode. Due to the electric field, for example, the positively charged charged particles 14 are aggregated, for example, on the second substrate 12 side close to the observer. In this state, the observer visually recognizes, for example, a white print of the charged particles 14.

  On the other hand, when the printing control unit 22 is switched to the voltage source 38b by the switch 39 and the printing voltage pulse becomes a negative voltage generated from the voltage source 38b, the conductive layer 23a is used as the positive electrode and the printing electrode 33 is used as the negative electrode. The charged particles 14 are agglomerated on the first substrate 11 side far from the observer due to the electric field generated in the observer 13, and the observer visually recognizes the color of the insulating liquid 15, for example, black.

  Here, at the same time that the plane area of the print electrode 33 becomes twice or more the plane area of the cell 13 of the display medium 10, a plurality of cells 13 are printed. When the plane area of the print electrode is smaller than the plane area of the cell 13, one cell 13 is printed by one print voltage pulse.

  As described above, in the printing apparatus 20 according to the present embodiment, the dispersion within the cells 13 of the display medium 10 is performed by the printing electrode 33 on the surface side of the printing head 21 pressed against the display medium 10 and the conductor layer 23 a of the transport roller 23. The liquid 16 is electrically polarized. Then, two colors corresponding to the direction in which the voltage is applied are displayed according to the polarity of the printing voltage pulse transmitted from the printing control unit 22. Here, the display medium 10 is transported in the transport direction 27b, which is the sub-scanning direction, with the transport rotation 27a of the transport roller 23 while receiving the printing operation as described above. When the voltage is not applied, the charged particles 14 remain agglomerated in the cell 13 and the display pattern is stored in memory and recorded.

  In the printing apparatus 20, the display pattern is formed in the same manner even with the EPD display medium described in FIG. 3 other than the display medium 10. When the display medium for EPD has a structure as shown in FIG. 3B, the transparent electrode layer 17 is on the upper surface of the second substrate 12, so that the transport roller 23 is used as the second electrode member. Thus, it is possible to use a guide roller 24 whose surface is at least grounded.

  Furthermore, the second electrode member is not a structure such as a roller whose surface is formed in a cylindrical shape or a columnar shape, but a structure that can be contacted and electrically connected without damaging the surface of the transparent electrode layer 17. It only has to be. For example, a curved body such as a copper wire having a curved surface may be used. In this case, since the second electrode member is electrically connected to the transparent electrode layer 17, it is easy to reduce the applied voltage when the display pattern is formed.

  The printing apparatus can easily form a display pattern on the above-described display medium at a low cost in exactly the same way as an image is formed on a recording sheet by a printer. And it becomes possible to provide a user with a large amount of low-cost display media on which a display pattern is formed.

  In the printing head 21 used in the printing apparatus, the printing electrode 33 can have various shapes. For example, the planar shape may be a dot shape. Further, the base insulating layer 32 may be formed flat. The printed electrode 33 may be arranged on the surface of the insulating substrate 31 and may have a wiring structure taken out to the surface through a via hole provided in the base insulating layer 32.

(Electrophoretic display device)
Next, an example of the electrophoretic display device according to the embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a schematic configuration diagram illustrating an example of an electrophoretic display device. FIG. 9 is a schematic top view showing an example of an erasing head used in the electrophoretic display device.

  As shown in FIG. 8, the electrophoretic display device 40 includes, as main components, a display medium 10, a printing head 21, an erasing head 41, a display control unit 42, a main transport roller 43, a sub transport roller 44, and guide rollers 45 and 45. I have. Here, the display medium 10 has been described with reference to FIGS. 1 and 2, and the print head 21 has been described with reference to FIGS. The erasing head 41 erases the existing display pattern of the display medium 10 so that a new display pattern can be formed. Then, as described with reference to FIG. 7, the printing head 21 prints the display medium 10 based on a command from the display control unit 42 to form a new display pattern.

  The main transport roller 43 is rotationally driven in a rotation direction 46 by a drive motor (not shown), and the sub transport roller 44 is not driven from a drive unit and freely rotates around its rotation axis. Then, as shown in FIG. 8, the display medium 10 is fed back and wound between the main transport roller 43 and the sub transport roller 44, and reciprocates in the moving directions 47a and 47b. ing. Here, for example, the first substrate 11 of the display medium 10 is formed so as to be light transmissive, and the second substrate 12 is not light transmissive. The display pattern printed and formed on the display medium 10 is visible from the first substrate 11 side, that is, from the front side of the drawing in FIG.

  Here, the main transport roller 43 and the sub transport roller 44 are made of a curved conductor such as a cylinder or a column or an insulator. At least the main transport roller 43 has a surface covered with a conductive material having an appropriate hardness.

  The guide rollers 45, 45 guide the display medium 10 in the moving direction 47 b, and press the first substrate 11 of the display medium 10 to the electrode side of the print head 21 and the erasing head 41 arranged at the back of the display medium 10. It is supposed to be. These guide rollers 45 serving as the second electrode member are made of a curved conductor such as a cylinder or a cylinder, or an insulator. When the guide roller 45 is made of an insulator, the surface of the guide roller 45 has an appropriate hardness. It is preferable that it is covered with a material. The main transport roller 43 and the sub transport roller 44 may also function as the second electrode member.

  Here, the erasing head 41 can erase the display pattern printed on the display medium 10, and comprises an erasing electrode substrate portion 48A and a drive circuit substrate portion 48B as shown in FIG. In the erasing electrode substrate portion 48A, a single erasing electrode 49 which is hatched in the drawing is formed in place of the printing electrode array composed of a large number of printing electrodes 33 in the printing electrode substrate portion 26A described in FIGS. ing. The single erasing electrode 49 covers the protrusion 32 a formed on the insulating substrate 31 and is arranged in a strip shape with a substantially constant width in the main scanning direction of the erasing head 41. Further, the driving IC 36 such as the printing head 21 is not necessary and is not attached to the driving circuit board portion 48B.

  Except for the above configuration, the structure of the erasing head 41 is substantially the same as that of the printing head 21. The erasing electrode 49 and the circuit pattern of the drive circuit board portion 48B are electrically connected by a bonding wire W, and the bonding wire W and the bonding region are hermetically sealed by a sealing material 37 made of, for example, a mold resin. Has been. The erase electrode 49 is covered with a protective layer 34 except for the bonding region.

  The erasing electrode 49 of the erasing head 41 is supplied with a constant voltage, for example, a constant voltage of a negative electrode, from the display control unit 42. Alternatively, an alternating voltage is supplied. Here, for example, when a negative constant voltage is applied, the main transport roller 43, the sub transport roller 44, or the guide roller 45 fixed to the ground potential is used as a positive electrode, and the erase electrode 49 is used as a negative electrode. For example, the positively charged charged particles 14 are agglomerated on the first substrate 12 side by the electric field formed in the inside 13. And all the cells 13 of the display medium 10 become white, for example. That is, all the display patterns printed on the display medium 10 are erased.

  Then, the erased display medium 10 is subjected to display control by the print head 21 arranged adjacent to the erase head 41 so that a new information display print is displayed on the display medium 10 as described with reference to FIGS. This is performed according to the information signal from the unit 42. For example, black is displayed as the color of the insulating liquid 15 in the cell 13 described above. Then, the display medium 10 moves in the moving direction 47a in accordance with the rotational drive of the main transport roller 43, and the display pattern of the information is visually recognized from the front side of the electrophoretic display device 40.

  In the electrophoretic display device 40, new information can be displayed continuously or intermittently. Further, it is possible to continue displaying the same information. In this case, it is only necessary to stop the operations of the erasing head 41 and the printing head 21 and only drive the main transport roller 43 to rotate.

  In the electrophoretic display device 40, the display pattern is formed in the same manner even if the display medium for EPD described in FIG. When the display medium for EPD has a structure as shown in FIG. 3B, the second electrode members are the main transport roller 43 and the sub transport roller 44 as described in the printing apparatus 20. Alternatively, it may be a structure different from the guide roller 45 and may be a curved body such as a copper wire having a curved surface, which is pressed and electrically connected without damaging the surface of the transparent electrode layer 17.

  In addition, the printing apparatus 20 described with reference to FIG. 4 and the various display media described above can be integrated into an electrophoretic display apparatus. Here, as in the case of the electrophoretic display device 40, the display pattern can be easily rewritten with the erasing head 41.

  The EPD display medium of the present embodiment is thin and excellent in flexibility, and can be as flexible as general recording paper. In addition, the electrophoretic display device with high versatility can be realized along with the cost reduction of the display medium.

  Although the preferred embodiments of the present invention have been described above, the above-described embodiments do not limit the present invention. Those skilled in the art can make various modifications and changes in specific embodiments without departing from the technical idea and technical scope of the present invention. For example, as a display medium for EPD, a display pattern is generated by a voltage applied between a first electrode member that presses the surface of a first substrate and a second electrode member that presses the surface of the second substrate. Anything can be used. The present invention can be applied even if the first substrate or the second substrate is made of an inflexible material or a non-insulating material.

It is sectional drawing which shows an example of the display medium concerning embodiment of this invention. (A) thru | or (c) is sectional drawing according to a manufacturing process which shows an example of the manufacturing method of a display medium. (A) And (b) is sectional drawing which shows the different modification of the display medium concerning embodiment of this invention. 1 is a schematic configuration diagram illustrating an example of a display medium printing apparatus according to an embodiment of the present invention. It is a top view which shows an example of the printing head used for the printing apparatus of FIG. FIG. 6 is an enlarged cross-sectional view taken along the line XX in FIG. 5. FIG. 5 is a schematic diagram for explaining the printing operation of the display medium by the printing apparatus according to the embodiment of the present invention. 1 is a schematic configuration diagram illustrating an example of an electrophoretic display device according to an embodiment of the present invention. It is a top view which shows an example of the erasing head used for the electrophoretic display device of FIG. It is a partially expanded sectional view which shows an example of the electronic paper of a prior art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Display medium, 11 ... 1st board | substrate, 11a ... Partition, 11b ... Substrate bottom part, 12 ... 2nd board | substrate, 13 ... Cell, 14 ... Charged particle, 15 ... Insulating fluid, 16 ... Dispersion liquid, 17 ... Transparent electrode 20 ... Printing device, 21 ... Print head, 22 ... Print control unit, 23 ... Conveying roller, 23a ... Conducting layer, 24, 45 ... Guide roller, 25 ... Support substrate, 26A ... Print electrode substrate unit, 26B, 48B ... Drive circuit board portion, 27a ... Transfer rotation, 27b ... Transfer direction, 31 ... Insulating substrate, 32 ... Base insulating layer, 32a ... Protrusion, 33 ... Print electrode, 34 ... Protective layer, 35 ... Drive circuit board, 36 ... Drive IC, 37 ... Sealing material, 38a, 38b ... Voltage source, 39 ... Switch, 40 ... Electrophoretic display device, 41 ... Erase head, 42 ... Display control unit, 43 ... Main transport roller, 44 ... Sub transport roller 46 direction of rotation, 7a, 47b ... moving direction, 48A ... erase electrode substrate portion, 49 ... erase electrode

Claims (10)

A first substrate and a second substrate, at least one of which is light transmissive and disposed opposite to each other;
A plurality of cells disposed between the first substrate and the second substrate and encapsulating an insulating liquid and charged particles dispersed in the insulating liquid;
A sheet-like display medium having
A display medium on which a display pattern is formed by an electric field selectively applied from the outside through the at least one substrate.   The display medium according to claim 1, wherein an electrode layer is formed on one surface of the second substrate, and an electric field is applied from the outside through the first substrate.   The display medium according to claim 1, wherein the cell is formed by embossing the first substrate. A first substrate and a second substrate, at least one of which is light transmissive and disposed opposite to each other, and disposed between the first substrate and the second substrate, and an insulating liquid and the second substrate A sheet-like display medium having a plurality of cells in which charged particles dispersed in an insulating liquid are sealed is in contact with each of the first substrate surface and the second substrate surface from the first substrate surface. An electrode member and a second electrode member,
A voltage is applied between the first electrode member and the second electrode member to generate an electric field in the cell, thereby moving the charged particles in the cell and printing a display pattern on the display medium. A printing apparatus characterized by that.   A first substrate having at least one optical transparency and disposed opposite each other and a second substrate having an electrode layer, and disposed between the first substrate and the second substrate for insulation A sheet-like display medium having a conductive liquid and a plurality of cells in which charged particles dispersed in the insulating liquid are enclosed, and a first electrode member in contact with the surface of the first substrate. And applying a voltage between the electrode layer of the second substrate and the first electrode member to generate an electric field in the cell, thereby moving the charged particles in the cell and the display medium. A printing apparatus characterized in that a display pattern is printed.   The first electrode member includes a support substrate, an insulating layer formed on a surface of the support substrate, a printing electrode group in which a plurality of electrodes are arranged on the insulating layer, and the printing electrode group 6. The printing apparatus according to claim 4, further comprising: a printing head having a protective layer made of an insulating material formed thereon, wherein the protective layer is in contact with the surface of the first substrate.   6. The printing apparatus according to claim 4, wherein the second electrode member is formed in a curved shape, and at least a surface thereof has conductivity and is in contact with a surface of the second substrate. A first substrate and a second substrate, at least one of which is light transmissive and disposed opposite to each other, and disposed between the first substrate and the second substrate, and an insulating liquid and the second substrate A plurality of cells enclosing charged particles dispersed in an insulating liquid, and a sheet-like display medium,
A first electrode member and a second electrode member which are in contact with the sheet-like display medium from the surface of the first substrate and the surface of the second substrate, respectively; A printing device that applies a voltage between the electrode members to generate an electric field in the cell, thereby moving the charged particles in the cell and printing a display pattern on the display medium;
An electrophoretic display device comprising: A support substrate, an insulating layer formed on the surface of the support substrate, a single electrode formed on the insulating layer, and a protective layer made of an insulator material formed on the single electrode; An erasing head having
9. The electrophoretic display device according to claim 8, wherein a display pattern on the display medium is erased by the erasing head, and a new display pattern is printed on the display medium by the printing apparatus.   In the erasing head, the protective layer on the single electrode is in contact with the surface of the first substrate of the display medium, and a voltage is applied between the display electrode and the second electrode member. The electrophoretic display device according to claim 9, wherein the electrophoretic display device is erased.

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