JP2008164738A - Display medium and display system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display medium with a low manufacturing cost, and a display system. <P>SOLUTION: Since a photoconductor 18 is disposed closer to a light transmitting substrate 12 side than a data electrode 20 and a pixel electrode 22, the photoconductor 18 is irradiated with light from the light transmitting substrate 12 side even if the data electrode 20 and the pixel electrode 22 are not composed of transparent materials. Consequently, materials for the data electrode 20 and the pixel electrode 22 are highly freely selected and the data electrode 20 and the pixel electrode 22 can be composed of inexpensive materials, and as a result an effect that the manufacturing cost of the display medium 10 is made inexpensive is attained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display medium and a display system, and more particularly to a display medium and a display system that are inexpensive to manufacture.

  Conventionally, rewritable display media such as electronic paper, liquid crystal display devices, and organic electroluminescence have been proposed. As one of such display medium driving methods, an active matrix driving method is known. When a display medium is driven by an active matrix driving method, it is necessary to form a field effect transistor on a substrate.

  Field effect transistors are roughly classified into inorganic transistors using inorganic semiconductors such as silicon and organic transistors using organic semiconductors. However, since a high temperature process is required when an inorganic transistor is formed on a substrate, it is difficult to manufacture the substrate on a substrate having low heat resistance such as a plastic substrate. On the other hand, since an organic transistor does not require a high-temperature process, for example, it can be formed on a plastic substrate. However, an organic transistor is likely to deteriorate over time and has a problem in stability. Therefore, unless many layers are sealed, it is difficult to use stably for a long time.

  Therefore, display media that do not use inorganic transistors or organic transistors have been proposed. As an example of such a display medium, a schematic configuration of a display medium provided with a display element and an optical switching element will be described.

  FIG. 10 is a diagram showing a schematic configuration of a conventional display medium and a writing device for writing an image on the display medium. As shown in FIG. 10, the display medium 100 includes a light incident side transparent electrode layer 132, in order from the light incident side transparent substrate 130, between the light incident side transparent substrate 130 and the display side transparent substrate 131 opposed thereto. The organic photoelectric switching element layer 134, the liquid crystal display element layer 136, and the display-side transparent electrode layer 138 are stacked.

  The writing device 120 includes a pattern forming unit 150 that forms a pattern according to image data, and a light irradiation unit 152 that irradiates the display medium 100 with writing light of the pattern formed by the pattern generation unit 150. .

When writing light is irradiated from the writing device 120, in the display medium 100, only the portion irradiated with the writing light makes the photoconductive switching element layer 134 conductive, and the portion not irradiated with the writing light remains non-conductive. . In this way, a desired pattern can be displayed on the display medium 100 by controlling the voltage applied to the liquid crystal display element layer 136 in accordance with the writing light.
JP 2002-2448066 A

  However, in the above configuration, since the writing device 120 has to generate a pattern corresponding to the image data in order to irradiate the writing light of the pattern to be formed on the display medium 100, the configuration of the writing device becomes complicated. There is a problem that an inexpensive display system cannot be provided. In the above configuration, since the electrode layer 138 is interposed between the light incident side transparent substrate 130 and the organic photoelectric switching element layer 134, in order to transmit light to the organic photoelectric switching element layer 134, The electrode layer 138 must be formed of an expensive transparent material, and the display medium 100 cannot be manufactured at low cost.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a display medium and a display system that are inexpensive to manufacture.

  To achieve this object, a display medium according to claim 1 includes a pixel electrode disposed on a light-transmitting light-transmitting substrate, a data electrode for supplying a data signal to be written to the pixel electrode, and the data Photoconductivity that electrically connects the data electrode and the pixel electrode by being connected to the data electrode and the pixel electrode and being irradiated with light on the translucent substrate side of the electrode and the pixel electrode A counter electrode disposed opposite to the pixel electrode, and a display layer disposed between the counter electrode and the pixel electrode and driven according to a data signal written to the pixel electrode. It is characterized by having.

  A display medium according to a second aspect of the present invention is the display medium according to the first aspect, wherein the capacitor electrode is formed closer to the light-transmitting substrate than the pixel electrode, and is disposed between the capacitor electrode and the pixel electrode. And an insulating film.

  The display medium according to claim 3 is the display medium according to claim 1 or 2, wherein the photoconductor is provided for each of a plurality of pixel electrodes, and each of the plurality of pixel electrodes is provided. The photoconductor provided for each pixel electrode is separated from each other for each pixel electrode.

  The display medium according to claim 4 is the display medium according to claim 1 or 2, wherein the photoconductor is arranged in layers between the data electrode, the pixel electrode, and the translucent substrate. It is what covers the one surface of the said translucent board | substrate, It is characterized by the above-mentioned. Here, “covering one surface of the light-transmitting substrate” is not limited to the case where the entire surface of the light-transmitting substrate is covered with the photoconductor, and at least in the display region in which the pixel electrode is disposed. This means that the photoconductor is disposed in a solid form.

  The display system according to claim 5 is a pixel electrode disposed on a translucent substrate having translucency, a data electrode for supplying a data signal to be written to the pixel electrode, and the data electrode and the pixel electrode, On the translucent substrate side, the data electrode and the pixel electrode are connected to the data electrode and the pixel electrode is electrically connected to electrically connect the data electrode and the pixel electrode. A photoconductor for non-conducting the data electrode and the pixel electrode, a counter electrode disposed opposite to the pixel electrode, and disposed between the counter electrode and the pixel electrode and written to the pixel electrode And a display medium having a display layer driven in accordance with the data signal, and a light irradiation means for irradiating the display medium with light.

  The display system according to claim 6 is the display system according to claim 5, wherein the display medium includes a capacitor electrode formed closer to the light-transmissive substrate than the pixel electrode, and the capacitor electrode and the pixel electrode. And an insulating film disposed therebetween.

  The display system according to claim 7 is the display system according to claim 5 or 6, wherein the irradiation position moving means for sequentially moving the irradiation position of the display medium by the light irradiation means, and the irradiation position movement means. And a data signal supply means for supplying a data signal corresponding to the moved irradiation position to the data electrode.

  8. The display system according to claim 8, further comprising: a light irradiation stop unit that stops light irradiation by the light irradiation unit while the data signal is being supplied by the data signal supply unit. It is characterized by.

  The display system according to claim 9 is the display system according to any one of claims 5 to 8, wherein the light irradiation unit narrows light from the light sources arranged in one direction and the display medium. And a light guide means for guiding the light.

  A display system according to a tenth aspect is the display system according to any one of the fifth to eighth aspects, wherein the light irradiation unit irradiates a laser beam.

  According to the display medium of claim 1, when the data electrode and the pixel electrode are electrically connected due to light being irradiated to the photoconductor, a data signal from the data electrode is written to the pixel electrode. The display layer is driven to display. Here, since the photoconductor is disposed closer to the light-transmitting substrate than the data electrode and the pixel electrode, the light from the light-transmitting substrate can be transmitted even if the data electrode and the pixel electrode are not made of a transparent material. The photoconductor is irradiated. Therefore, there is a high degree of freedom in selecting the material for the data electrode and the pixel electrode, and the data electrode and the pixel electrode can be made of an inexpensive material, which has the effect of reducing the manufacturing cost of the display medium.

  Note that “electrically conducting the data electrode and the pixel electrode” means that the photoconductor connected to the data electrode and the pixel electrode is lowered in impedance by light irradiation, and an electrical equivalent circuit includes a conductor and It means reducing the resistance to a level that can be seen.

  Preferably, the photoconductor electrically connects the data electrode and the pixel electrode when irradiated with light having a predetermined wavelength or when irradiated with light having a predetermined threshold value or more. Even if light is irradiated, if the wavelength or intensity of light does not satisfy the conditions, the data electrode and the pixel electrode are left non-conductive. In this way, it is possible to suppress the resistance of the photoconductor from being lowered by unexpected light such as natural light or illumination light.

  According to the display medium of the second aspect, in addition to the effect produced by the display medium of the first aspect, the capacitive electrode formed on the light-transmitting substrate side with respect to the pixel electrode, and between the capacitive electrode and the pixel electrode Therefore, the insulating film between the pixel electrode and the capacitor electrode serves as a capacitor, and the data signal written to the pixel electrode can be held. Therefore, the data signal supply time can be shortened, and the time required for writing can be shortened.

  According to the display medium of the third aspect, in addition to the effect achieved by the display medium of the first or second aspect, the photoconductor is disposed separately from each other for each pixel electrode. A data signal can be written only to the pixel electrode. Therefore, there is an effect that high quality display can be realized.

  According to the display medium of the fourth aspect, in addition to the effect of the display medium according to the first or second aspect, the photoconductor is arranged in a layer between the data electrode and the pixel electrode and the translucent substrate. Since it covers one surface of the light-transmitting substrate, for example, the photoconductor layer is formed on one surface by spin coating, and the manufacturing is easy and the manufacturing cost is lower. There is.

  According to the display system of claim 5, when the data electrode and the pixel electrode are electrically connected due to light being applied to the photoconductor, a data signal from the data electrode is supplied to the pixel electrode. The display layer is driven in accordance with the data signal written to the pixel electrode to display. Here, since the photoconductor is disposed closer to the light-transmitting substrate than the data electrode and the pixel electrode, the light from the light-transmitting substrate can be transmitted even if the data electrode and the pixel electrode are not made of a transparent material. The photoconductor is irradiated. In other words, there is a high degree of freedom in selecting the material for the data electrode and the pixel electrode, and the data electrode and the pixel electrode can be made of an inexpensive material, so that the manufacturing cost of the display medium can be reduced. is there.

  Further, when light is not irradiated, the data electrode and the pixel electrode are made non-conductive, so that the data signal is not written to the pixel electrode. Therefore, for example, a data signal can be written for each predetermined region, such as writing a data signal for each pixel or writing a data signal for each line. Therefore, compared with the case where the entire pattern to be displayed on the display medium is once generated on the writing device side and projected onto the display medium, the configuration is simple and the manufacturing cost is reduced.

  According to the display system of claim 6, in addition to the effect of the display system of claim 5, the display medium is a capacitive electrode formed on the light-transmitting substrate side with respect to the pixel electrode, the capacitive electrode, and the pixel Since the insulating film disposed between the electrode and the electrode is provided, the insulating film between the pixel electrode and the capacitor electrode serves as a capacitor, and the data signal written to the pixel electrode can be held. Therefore, the data signal writing time for each pixel electrode can be shortened.

  According to the display system of the seventh aspect, in addition to the effect produced by the display system according to the fifth or sixth aspect, the irradiated position of the display medium is sequentially moved by the irradiated position moving means, and the moved target is moved. Since the data signal corresponding to the irradiation position is supplied to the data electrode, the data signal can be written sequentially for each predetermined region. Therefore, there is an effect that the configuration is simple and the manufacturing cost is low.

  According to the display system of the eighth aspect, in addition to the effect produced by the display system of the seventh aspect, since the light irradiation by the light irradiation means is stopped during the supply of the data signal, the data signal is stopped. Prior to this, the data electrode and the pixel electrode are made non-conductive. Therefore, it is possible to suppress the influence of the stop of the data signal from reaching the pixel electrode, and to realize a high quality display.

  According to the display system of the ninth aspect, in addition to the effect produced by the display system according to any one of the fifth to eighth aspects, the light irradiation means includes a light source arranged in one direction and light from the light source. Since the light guide means that narrows down and guides it to the display medium is provided, light can be irradiated only to a very narrow region, and there is an effect that high-definition display can be performed.

  According to the display system of the tenth aspect, in addition to the effect exhibited by the display system according to any one of the fifth to eighth aspects, the light irradiating means irradiates a laser beam, and therefore only in a very narrow region. There is an effect that light can be irradiated and high-definition display can be performed.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram illustrating a display medium 10 according to the first embodiment of the present invention.

  As shown in FIG. 1, the display medium 10 includes a light-transmitting substrate 12, a counter substrate 14 disposed to face the light-transmitting substrate 12, and a sealing material 16 provided along the periphery of the counter substrate 14. It is mainly provided. Although details will be described later with reference to FIG. 2, a display layer 26 (see FIG. 2) containing charged particles is filled between the light-transmitting substrate 12 and the counter substrate 14, and the edge is sealed. It is sealed with a material 16. In addition, a plurality of data electrodes 20 parallel to each other are disposed on the transparent substrate 12, and one end of each data electrode 20 is exposed on the outer peripheral side of the counter substrate 14. Although details will be described later with reference to FIG. 3, the display layer 26 (see FIG. 2) is driven according to the data signal supplied to the data electrode 20, and an image is displayed on the counter substrate 14. In addition, although the insulating film 15 is coat | covered by the upper surface of the translucent board | substrate 12, in order to prevent drawing becoming complicated, illustration is abbreviate | omitted in FIG.

  The translucent substrate 12 and the counter substrate 14 are both translucent substrates, and examples of the material thereof include glass, synthetic resin, and natural resin. A preferable material of the light-transmitting substrate 12 and the counter substrate 14 is a synthetic resin exhibiting flexibility. , Polyimide, nylon, polypropylene, and hard polyethylene (high density polyethylene). Among these synthetic resins, polyethylene terephthalate, polyethylene naphthalate, and polyphenylene sulfide are particularly preferable materials in terms of transparency, strength, and heat resistance. By using the material having flexibility as described above as the light-transmitting substrate 12 and the counter substrate 14, the entire display medium 10 can exhibit flexibility.

  Next, the structure of the display medium 10 will be described more specifically with reference to FIG. FIG. 2A is a diagram schematically illustrating electrodes disposed on the light-transmitting substrate 12 of the display medium 10, and FIG. 2B is a cross-sectional view illustrating an enlarged part of the display medium 10. It is. 2B is a cross-sectional view taken along a cutting line that passes through the photoconductor 18 and is substantially orthogonal to the data electrode 20 (see the IIb-IIb line in FIG. 2A). Although the cross section is illustrated, the protective layer 24, the display layer 26, the counter electrode 34, and the counter substrate 14 illustrated in the cross section of FIG. 2B are illustrated in FIG. The illustration is omitted to prevent complication.

  As shown in FIG. 2B, the transparent electrode 12 is provided with a capacitor electrode 13, an insulating film 15, a photoconductor 18, a data electrode 20, and a pixel electrode 22 on the surface facing the counter substrate 14. It is installed. A counter electrode 34 is provided on substantially the entire surface of the counter substrate 14 on the side facing the translucent substrate 12. In the following description, the longitudinal direction of the data electrode 20 is referred to as the Y direction of the display medium 10, and the direction orthogonal to the longitudinal direction of the data electrode 20 is referred to as the X direction of the display medium 20.

  The photoconductor 18 is a member made of a material that exhibits a low resistance when irradiated with light of a predetermined wavelength and exhibits a high resistance value when not irradiated with light of a predetermined wavelength. For example, phthalocyanine, polyvinyl It is composed of an organic material such as carbazole, an inorganic material such as amorphous silicon, or an inorganic oxide such as zinc oxide or titanium oxide. As shown in FIG. 2B, the photoconductor 18 is disposed on the side of the transparent substrate 12 with respect to the data electrode 20 and the pixel electrode 22 and connected to both the data electrode 20 and the pixel electrode 22. . When light is irradiated, the resistance of the photoconductor 18 is reduced (the photoconductor 18 is turned on), and the data electrode 20 and the pixel electrode 22 are electrically connected. On the other hand, when light is not irradiated, the photoconductor 18 returns to the original resistance value (the photoconductor 18 is turned off), and the data electrode 20 and the pixel electrode 22 are electrically disconnected. As described above, the photoconductor 18 functions as a switch between the data electrode 20 and the pixel electrode 22.

  The data electrode 20 is an electrode formed in a plurality of substantially parallel lines. Each data electrode 20 is provided with a plurality of pixel electrodes 22 at a predetermined interval, and each data electrode 20 supplies a data signal for writing to the plurality of pixel electrodes 22. Since the data electrode 20 and the pixel electrode 22 are arranged apart from each other and are connected via the photoconductor 18 that functions as a switch, a voltage (data signal) is applied to the data electrode 20 A data signal is supplied to the pixel electrode 22 only at a location where the photoconductor 18 is on, and no data signal is supplied to the pixel electrode 22 at a location where the photoconductor 18 is off.

  A plurality of pixel electrodes 22 are arranged in a matrix in the X direction and the Y direction. An area covered by one pixel electrode 22 corresponds to one pixel of the display medium 10, and an area covered by all the arranged pixel electrodes 22 corresponds to a display area of the display medium 10. As shown in FIG. 2A, a row of pixel electrodes 22 arranged in the Y direction (longitudinal direction in FIG. 2A) includes data from one data electrode 20 disposed via the photoconductor 18. A signal is written. When a data signal is written to the pixel electrode 22, an electric field is generated between the pixel electrode 22 and a counter electrode 34 described later, and the display layer 26 (see FIG. 2B) can be driven.

  As shown in FIG. 2B, the capacitor electrode 13 is disposed at a position facing the pixel electrode 22 in the lower layer of each pixel electrode 22 on the light transmitting substrate 12 side. One capacitor electrode 13 is disposed corresponding to one pixel electrode 22. Between the capacitor electrode 13 and the pixel electrode 22, an insulating film 15 that covers the upper surface of the translucent substrate 12 is disposed. The capacitor electrode 13 is grounded, and the insulating film 15 between the pixel electrode 22 and the capacitor electrode 13 serves as a capacitor. Even after the photoconductor 18 is turned off, data is written to the pixel electrode 22. The data signal is retained. In the present embodiment, the description will be made assuming that the capacitive electrode 13 is provided, but the capacitive electrode 13 may not be provided.

  Note that the capacitor electrode 13, the data electrode 20, the pixel electrode 22, and the counter electrode 34 are not particularly limited as long as they have conductivity, and are not limited to materials thereof. Metal, semiconductor, conductive resin, conductive paint Further, it can be composed of various materials such as conductive ink and inorganic transparent conductor. In particular, the data electrode 20 and the pixel electrode 22 do not need to be made of a transparent electrode material, and can be made of an inexpensive electrode material.

  As described above, in order for the photoconductor 18 to function as a switch, it is necessary to irradiate the photoconductor 18 with light. However, according to the display medium 10 of the present embodiment, since the photoconductor 18 is disposed closer to the transparent substrate 12 than the electrodes (the data electrode 20 and the pixel electrode 22), the electrode is made of an opaque material. This is because even if configured, the light irradiated from the translucent substrate 12 side can reach the photoconductor 18.

  Further, as shown in FIG. 2B, a protective film 24 is provided on the formation surface of the data electrode 20 and the pixel electrode 22 in the transparent substrate 12. The protective film 24 prevents direct contact between the electrophoretic medium 32 and the electrodes (the data electrode 20 and the pixel electrode 22), which will be described later, so that the electrodes (the data electrode 20 and the pixel electrode 22) in the display medium 10 are not deteriorated. Can be prevented. The protective film 24 is excellent in water repellency, oil repellency, corrosion resistance, chemical resistance, and the like, and therefore, for example, an inorganic oxide thin film such as silicon oxide and aluminum oxide, polyimide resin, polyvinyl alcohol resin, fluorine It can be composed of a polymer resin thin film such as a resin. Note that a liquid-resistant protective film is also provided on the surface of the counter substrate 14 where the counter electrode 34 is formed. However, in order to prevent the drawing from becoming complicated, in FIG. The illustration of the protective film is omitted.

  The display layer 26 is a layer composed of a liquid electrophoretic medium 32 containing charged particles (white charged particles 28 and black charged particles 30) that are positively or negatively charged. The display layer 26 is provided between the pixel electrode 22 on the transparent substrate side 12 in the display medium 10 and the counter electrode 34, and is driven according to a data signal written to the pixel electrode 22.

The white charged particles 28 are made of a resin dyed white with a pigment or a dye, and are positively charged, for example. The black charged particles 30 are made of a resin dyed black with a pigment or dye, and are charged with a polarity opposite to that of the white charged particles 28.
The electrophoretic medium 32 is preferably a transparent solvent having high electrical resistance (high insulation), and examples thereof include oily polysiloxane such as silicone oil.

  The display principle when the white charged electrophoretic particles 28 are positively charged and the black charged particles 30 are negatively charged will be described. First, when the counter electrode 34 is used as a common electrode and a positive data signal is written to the pixel electrode 22, the positively charged white charged particles 28 gather on the counter electrode 34 side, and thus an observer viewed from the counter substrate 14 side. On the side, the pixel is white. On the other hand, the black charged particles 30 charged with the opposite polarity to the white charged particles 28 gather on the pixel electrode 22 side and are not visually recognized. On the contrary, when a negative data signal is written to the pixel electrode 22, the black charged particles 30 gather on the counter electrode 34 side, so that black is observed on the observer side viewed from the counter substrate 14 side and black display is performed. It becomes a pixel.

  With reference to FIG. 3, the relationship between the data signal supplied to each data electrode and the display state will be described. FIG. 3A is a diagram showing data signals supplied to each data electrode 20, and FIG. 3B is a diagram when the data signals shown in FIG. It is a figure which shows typically the display state.

  In FIG. 3, a case where a data signal is written to the pixel electrodes 22 for one line arranged in the X direction will be described as an example. First, as shown in FIG. 3A, description will be made assuming that either a −10V or + 10V data signal is supplied to each data electrode 20. On the other hand, light L having a predetermined wavelength is irradiated from the light projecting substrate 12 side of the display medium 10 to one line for which data signal writing is desired. In this way, the photoconductor 18 is turned on only for one line irradiated with the light L, and the photoconductors 18 of other lines not irradiated with the light L are turned off. Therefore, the data signal is written only to the pixel electrodes 22 for one line irradiated with the light L.

  Then, as shown in FIG. 3B, the display layer 26 is driven in accordance with the data signal written to each pixel electrode 22. For example, in a pixel in which a data signal of +10 V is written to the pixel electrode 22, the positively charged white charged particles 28 (see FIG. 2B) move to the counter substrate 14 side and are viewed from the counter substrate 14 side. On the observer side, the pixel is white. On the other hand, in a pixel in which a data signal of −10 V is written to the pixel electrode 22, the negatively charged black charged particles 30 (see FIG. 2B) move to the counter substrate 14 side and are viewed from the counter substrate 14 side. On the observer side, the pixel is black.

  Note that after the irradiation of the light L is stopped, the photoconductor 18 is turned off. Here, since the capacitive electrode 13 (see FIG. 2B) is disposed below the pixel electrode 22, the data signal written to the pixel electrode 22 does not immediately disappear, but for a while. , Retained. Furthermore, when the state is left for a long time, the data signal written to the pixel electrode 22 is lost, but the charged particles (white charged particles 28 and black charged particles 30) are attracted by electrostatic adsorption or intermolecular force. The display state is maintained by staying on the side of each electrode (pixel electrode 22 or counter electrode 34).

  According to the display medium 10 of the first embodiment, the photoconductor 18 is disposed between the data electrode 20 and the pixel electrode 22, so that light is used between the data electrode 20 and the pixel electrode 22. The current flowing through can be controlled. Therefore, it is not necessary to provide a field effect transistor for each pixel, and the display medium 10 can be configured at low cost.

  In addition, each photoconductor 18 is provided for each of the plurality of pixel electrodes 22, and each photoconductor 18 is disposed separately for each pixel electrode 22. In other words, one photoconductor 18 connected to one pixel electrode 22 is not in contact with another adjacent pixel electrode 22. Therefore, when one photoconductor 18 is turned on, a data signal is written only to one pixel electrode 22 in contact with the photoconductor 18 and does not affect other adjacent pixel electrodes 22. High quality display can be realized.

  A display system 40 according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a perspective view showing an external configuration of the display system 40 of the second embodiment. As shown in FIG. 4, the display system 40 includes the display medium 10 according to the first embodiment described above and a writing device 50. In the display system 40, the display medium 10 and the writing device 50 are configured separately. Therefore, after the writing device 50 writes an image on the display medium 10, the display medium 10 can be detached from the writing device 50 and carried freely. As described above, according to the display medium 10 of the present embodiment, the display state is maintained even after the supply of the data signal is stopped. Therefore, even when the display medium 10 is removed from the writing device 50 and carried, The image written on the medium 10 is retained without being erased.

  The writing device 50 has a substantially rectangular parallelepiped outer shape, and is mainly provided with a main body 52, a platen glass 54, a light irradiation device 58, and a cover 60. The writing device 50 is mainly connected to a computer (not shown), supplies a data signal to the display medium 10 based on image data transmitted from the computer, and writes an image.

  The main body 52 has a substantially rectangular parallelepiped outer shape, and the upper surface is greatly opened. And the platen glass 54 comprised by transparent plate-shaped members, such as a glass plate, is engage | inserted by the opening part, for example. In the main body 52, a space for moving the light irradiation device 58, a space for supporting the light irradiation device 58, and a function for driving the light irradiation device 58 is secured. It is formed larger than.

  The platen glass 54 is formed in a rectangular shape in plan view, and has a size that allows the display medium 10 to be placed thereon. As shown in FIG. 4, since the platen glass 54 is fitted at a position lower than the upper surface of the main body 52, a step 56 exists between the edge of the platen glass 54 and the upper surface of the main body 52. . Using this step 56, the edge of the platen glass 54 and the edge of the display medium 10 are aligned, and the display medium 10 can be accurately placed at a predetermined position on the platen glass 54.

  The light irradiator 58 is provided with light sources arranged in one direction. By causing the light sources to emit light, the light irradiator 58 emits light of a predetermined wavelength toward the upper side (that is, the platen glass 54 side) (hereinafter referred to as a line). Light). The light irradiation device 58 is provided in the main body 52 so as to be capable of reciprocating in a direction perpendicular to the arrangement direction of the light sources. Hereinafter, the arrangement direction of the light sources in the light irradiation device 58 is referred to as the X direction of the light irradiation device 58, and the reciprocating direction of the light irradiation device 58 is referred to as the Y direction of the light irradiation device 58.

  The light irradiation device 58 of the present embodiment will be described on the assumption that the display medium 10 can irradiate the photoconductor 18 for one line aligned in the X direction at a time. The light irradiation device 58 includes a cylindrical lens (an example of a light guide unit described in claims) that further narrows down the linear light emitted from the light source and guides the light to the display medium 10. In this way, only a very narrow range of the display medium 10 can be irradiated, so that high-definition images can be written.

  The cover 60 is openably and closably attached to the main body 52 via a hinge (not shown) on the back side. When the display medium 10 is placed on the platen glass 54 with the counter substrate 14 side up, and the cover 60 is closed, the lower surface of the cover 60 is in contact with the upper surface of the display medium 10. A data signal output terminal 62 is provided on the lower surface of the cover 60. The same number of data signal output terminals 62 as the data electrodes 20 exposed in the display medium 10 are formed.

  As shown in FIG. 4, when the display medium 10 is placed so that the upper left corner of the display medium 10 and the upper left corner of the platen glass 54 are aligned and the cover 60 is closed, the data exposed on the display medium 10 is displayed. The electrode 20 and the data signal output terminal 62 provided on the cover 60 are in a one-to-one contact, and an electrical contact is made. A data signal is supplied to the display medium 10 through this contact.

  According to the writing device 50, the light irradiating device 58 irradiates the display medium 10 with one line of photoconductors 18 arranged in the X direction, and supplies a data signal to the display medium 10, thereby supplying one line. The data signal can be written to the pixel electrode 22 of the minute. After the data signal for one line is written, the light irradiation device 58 is moved by one line in the Y direction of the writing device 50 and the display medium 10, and the data signal is written to the next one line in the display medium 10. . By repeating such an operation, it is possible to write data electrodes to the pixel electrodes 22 for all lines and display a desired image on the display medium 10.

  FIG. 5 is a block diagram showing an electrical configuration of the writing device 50 described above. As shown in FIG. 5, the writing device 50 includes a CPU 70, a ROM 72, a RAM 74, an interface (hereinafter referred to as I / F) 76, a light irradiation device 58, a light irradiation device driving motor 78, and data. A signal generation circuit 80 is provided, and these are connected via a bus.

  The CPU 70 is a central processing that controls the writing device 50 as a whole, and executes various programs such as a program that executes the processing shown in the flowchart of FIG. The ROM 72 is a non-volatile memory that stores various control programs executed by the CPU 70 and fixed value data, and the RAM 74 temporarily stores data and programs necessary for various processes executed by the CPU 70. .

  The I / F 76 is an interface for wired connection or wireless connection of an external device such as a personal computer (PC), and data of the external device such as a personal computer (PC) connected via the I / F 76 is transmitted. Controls input and output.

  The light irradiation device drive motor 78 is a motor for reciprocating the light irradiation device 58 described above along the longitudinal direction of the conveyance rail provided in the Y direction (see FIG. 4) of the writing device 50. The driving is controlled by the CPU 70. The data signal generation circuit 80 generates a data signal according to the image data input via the I / F 76 and supplies the data signal to the data signal output terminal 62.

  With reference to FIG. 6, the writing process executed by the writing device 50 configured as described above will be described. FIG. 6 is a flowchart of the writing process executed by the writing device 50 according to the second embodiment. This writing process is started when the display medium 10 is placed on the platen glass 54, the cover 62 is closed, and a writing execution command is input. Here, the write execution command is input by an operation of an execution button (not shown) provided in the writing device 50 or a predetermined operation performed on a PC connected via the I / F 76.

  In this writing process, first, the variable N is set to “1” (S2), and then the light irradiation device drive motor 78 (see FIG. 5) is driven to irradiate the Nth line of the display medium 10. Next, the light irradiation device 58 is conveyed (S4). In the present embodiment, the Nth line is the number of lines counted in the Y direction starting from the side where the data electrode 20 of the display medium 10 is exposed.

  Then, after the conveyance of the light irradiation device 58 is completed, the light source of the light irradiation device 58 is caused to emit light, and the line light having a predetermined wavelength is irradiated (S6). Thereby, the line light is irradiated to the Nth line of the display medium 10. Next, by driving the data signal generation circuit 80 (see FIG. 5), a data signal to be written in the Nth line is generated and supplied to the data electrode 20 of the display medium 10 via the data signal output terminal 62 (see FIG. 5). S8). Since line light is being irradiated to the Nth line, only the photoconductor 18 of the Nth line is on. Therefore, the data signal supplied to each data electrode 20 is written only to the pixel electrode 22 of the Nth line, and not written to the pixel electrodes 22 of other lines.

  Next, the irradiation of the line light by the light irradiation device 58 is stopped (S10). As a result, the Nth photoconductor 18 is turned off. Therefore, the data electrode 20 and the pixel electrode 22 are made non-conductive, and the writing of the data signal from the data electrode 20 to the pixel electrode 22 is completed. Here, in order to drive the display layer 26, a data signal needs to be applied to the pixel electrode 22 for a predetermined time. According to the display medium 10 of the present embodiment, the data signal written to the pixel electrode 22 is held for a while by the capacitive electrode 13 disposed in the lower layer of the pixel electrode 22. The writing time of the data signal to the electrode 22 can be shortened. As a result, writing can be performed at high speed as a whole.

  Next, the supply of the data signal from the data signal output terminal 62 is stopped (S12). By stopping the supply of the data signal, the voltage of the data electrode 20 becomes 0 V. However, since the photoconductor 18 is turned off before this, the pixel electrode 22 may be affected by the stop of the data signal. Suppressed and high quality display can be realized.

  Next, “1” is added to N (S14), and it is determined whether or not all lines have been written (S16). When the last line has not been written (S16: No), the process returns to S4. And the light irradiation apparatus 58 is conveyed (S4). As a result, the irradiated position is moved to the next line adjacent in the Y direction (S4), and the line light is irradiated and the data signal is supplied to the next line. When the process is repeated until the last line of the display medium 10 is written (S16: Yes), the writing process is terminated.

  According to the display system 40 of this embodiment, the irradiated position of the display medium 10 is sequentially moved line by line, and a data signal corresponding to the moved irradiated position is supplied to the data electrode 20. That is, data signals can be sequentially written line by line. Therefore, the configuration of the writing device 50 is simpler than the conventional method (see FIG. 10) in which a pattern to be displayed on the display medium is once generated on the writing device side and projected onto the display medium. Yes, the manufacturing cost is low.

  A display system according to a third embodiment of the present invention will be described with reference to FIGS. The display system of the third embodiment is different in that a writing device 90 is provided instead of the writing device 50 in the display system 40 of the second embodiment, and the others are common. Therefore, in the third embodiment, the writing device 90 will be mainly described.

  The writing device 50 according to the second embodiment described above emits line-shaped light. On the other hand, the writing device 90 of the third embodiment is different from the writing device 50 of the second embodiment in that the spot-shaped laser beam is irradiated. In the description of the writing device 90 of the third embodiment, the same components as those of the writing device 50 of the second embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 7 is a block diagram showing an electrical configuration of the writing device 90 according to the third embodiment. As shown in FIG. 7, the writing device 90 is provided with a laser light irradiation device 92 instead of the light irradiation device 58. The laser light irradiation device 92 is provided with a laser light emitting unit that emits spot-like laser light (an example of light described in claims), and irradiates the display medium 10 while scanning with the laser light. In addition, since such a laser beam irradiation apparatus 92 is a well-known structure, detailed illustration and description of a structure are abbreviate | omitted.

  The writing process executed by the writing device 90 will be described with reference to FIG. FIG. 8 is a flowchart of a writing process executed by the writing device 90 according to the third embodiment. This writing process is started when the display medium 10 is placed on the platen glass 54, the cover 62 is closed, and a writing execution command is input.

  In this writing process, first, the variable M and the variable N are set to “1” (S32). Next, a laser beam is irradiated by the laser beam irradiation device 80 with the photoconductor 18 of the Nth pixel in the Mth line as the irradiated position (S34). When the laser beam is irradiated, the photoconductor 18 of the Mth line N pixel is turned on, and the Nth data electrode 20 and the pixel electrode 22 of the Mth line N pixel become conductive. In the present embodiment, the Mth line is the number of lines counted in the Y direction starting from the side where the data electrode 20 of the display medium 10 is exposed, and the Nth pixel is the counter substrate 14 of the display medium 10. This is the number of pixels counted in the X direction starting from the left end.

  Next, the data signal generation circuit 80 (see FIG. 7) outputs a data signal to be written to the pixel electrode 22 of the Mth line Nth pixel to the Nth data electrode 20 (S36). As described above, since only the M line Nth pixel electrode 22 and the Nth data electrode 20 are electrically connected to each other by laser light irradiation, the data signal supplied to the data electrode 20 is the Mth line Nth. It is written only to the pixel electrode 22 and not written to the other pixel electrodes 22.

  Next, the supply of the data signal from the data signal output terminal 62 is stopped (S40). Next, “1” is added to N (S42), and it is determined whether or not the data signal has been written to all the pixel electrodes 22 in the M-th line (S44). When data signals are not yet written to all the pixel electrodes 22 (S44: No), the process returns to the process of S34, and the irradiation position by the laser beam irradiation device 80 is set to the next pixel electrode 22 adjacent in the X direction. It is moved (S34), and laser light irradiation and data signal supply are repeated. If data signals are written to all the pixel electrodes 22 in the M-th line while repeating the process in this way (S44: Yes), the variable N is set to "1" (S46), and "1" is set to M. Add (S48). Next, it is determined whether or not all lines have been written (S50). If the data signal has not yet been written up to the final line (S50: No), the process returns to S34, and the irradiation position by the laser beam irradiation device 80 is moved to the first pixel of the next line adjacent in the Y direction. (S34), laser beam irradiation and data signal output are repeated. If the writing up to the last line is completed while repeating the process in this way (S50: Yes), the writing process is terminated.

  According to the display system of the third embodiment, the irradiated position of the display medium 10 is sequentially moved, and a data signal corresponding to the moved irradiated position is supplied to the data electrode 20, so that the data signal is 1 Sequential writing can be performed pixel by pixel. Therefore, the configuration of the writing device 90 is simpler than the conventional method (see FIG. 10) in which a pattern to be displayed on the display medium 10 is once generated on the writing device side and projected onto the display medium. Thus, the manufacturing cost is low.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications and changes can be easily made without departing from the spirit of the present invention. Can be inferred.

  For example, in the display medium 10, the photoconductor 18 is provided for each pixel electrode 22 and is provided separately for each pixel electrode 22. Instead of this, the photoconductor 18 may be disposed in layers so as to cover one surface of the light-transmitting substrate 12. Here, “covering one surface of the light-transmitting substrate 12” is not limited to the case where the entire surface of the light-transmitting substrate 12 is covered with the photoconductor 18, and at least the pixel electrode 22 is disposed. This means that the photoconductor 18 is disposed in a solid shape in the displayed area.

  FIG. 9 is a diagram schematically showing electrodes and photoconductors 18 provided on the light-transmitting substrate 12 in the display medium 10 according to the modification. As shown in FIG. 9, if the photoconductor 18 is disposed in a solid shape on one surface of the translucent substrate 12, and further the data electrode 20 and the pixel electrode 22 are disposed thereon, the photoconductor 18 can be formed by an inexpensive and easy technique such as spin coating. When the photoconductor 18 is arranged in a layer on the entire surface of the translucent substrate 12 as described above, the writing device that irradiates the spot-shaped laser light described in the third embodiment is used as the writing device. A device 90 is preferably used. If only a very small area of the photoconductor 18 for one pixel is irradiated with a sufficiently narrow laser beam, even if the photoconductor 18 is continuously provided, only the target pixel electrode 22 is obtained. This is because conduction to the data electrode 20 can realize high-definition image display.

  Further, the display medium 10 of the above-described embodiment has been described as performing monochrome display, but the present invention can also be applied to a display medium configured to be capable of color display.

  In addition, the display layer 26 of the display medium 10 according to the above-described embodiment uses a so-called electrophoresis method in which an image is displayed by causing the charged particles 28 and 30 to migrate. Not limited to. In particular, a display layer having a property of maintaining a display state even when an external voltage becomes zero, such as a ferroelectric liquid crystal, can be preferably used.

  In the display system 40 according to the above-described embodiment, the user manually places the display medium 10 on the platen glass 54 and writes a data signal on the display medium 10. Instead of this, for example, a configuration similar to an automatic paper feeder provided in a scanner or a copier may be provided in the writing devices 50 and 90 to automatically feed the display medium 10. In this way, the display medium 10 can be sent to an accurate writing position, so that a configuration for alignment need not be provided.

  In addition, the light irradiation device 58 of the writing device 50 has been described as being provided with a light source arranged in one direction for irradiating line light. This light irradiation device 58 is a so-called line image sensor that reads the image by guiding the reflected light from the platen glass 54 side to the photoelectric conversion element through a lens, and the photoelectric conversion element outputs an electric signal corresponding to the intensity of the reflected light. It may be configured. In this way, the writing device 50 can be used not only as a device for writing an image on the display medium 10, but also as a scanner for reading a document placed on the platen glass 54, for example.

  Further, in the above-described embodiment, the data signal generation circuit 80 and each data electrode 20 are electrically connected to each other by contacting the portion of the data electrode 20 exposed on the outer peripheral side of the counter substrate 14 and the data signal output terminal 62. However, as long as the data signal generation circuit 80 and each data electrode 20 are connected, any form may be used.

  Further, in the writing process of the second embodiment described above (see FIG. 6), after one line is irradiated by the light irradiation device 58 and before the next one line is irradiated, the light irradiation device 58 is temporarily used. However, instead of stopping the line light irradiation, the light may be continuously irradiated.

It is a figure explaining the display medium in 1st Embodiment of this invention. (A) is a figure which shows typically the electrode arrange | positioned at the translucent board | substrate of a display medium, (b) is sectional drawing which expands and shows a part of display medium. (A) is a figure which shows the data signal supplied to each data electrode, (b) shows typically the display state when the data signal shown to (a) is written in each pixel electrode. FIG. It is a perspective view which shows the external appearance structure of the display system of 2nd Embodiment. It is a block diagram which shows the electric constitution of the writing device in 2nd Embodiment. It is a flowchart of the writing process performed with the writing device of 2nd Embodiment. It is a block diagram which shows the electric constitution of the writing device in 3rd Embodiment. It is a flowchart of the writing process performed with the writing device of 3rd Embodiment. It is a figure which shows typically the electrode and photoconductor which were arrange | positioned in the translucent board | substrate in the display medium of a modification. It is a figure which shows schematic structure of the conventional display medium and the writing apparatus which writes an image in the display medium.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Translucent board | substrate 18 Photoconductor 20 Data electrode 22 Pixel electrode 26 Display layer 34 Counter electrode 58 Light irradiation apparatus (an example of a light irradiation means)
92 Laser light irradiation device (an example of light irradiation means)
L light S4 one example of irradiated position moving means S8 one example of data signal supplying means S10 one example of light irradiation stopping means S34 one example of irradiated position moving means S36 one example of data signal supplying means

Claims (10)

A pixel electrode disposed on a translucent substrate having translucency;
A data electrode for supplying a data signal to be written to the pixel electrode;
The data electrode and the pixel electrode are electrically connected between the data electrode and the pixel electrode by being connected to the data electrode and the pixel electrode on the light transmitting substrate side of the data electrode and the pixel electrode. A photoconductor;
A counter electrode disposed to face the pixel electrode;
A display medium, comprising: a display layer disposed between the counter electrode and the pixel electrode and driven in accordance with a data signal written to the pixel electrode. A capacitor electrode formed closer to the light-transmitting substrate than the pixel electrode;
The display medium according to claim 1, further comprising an insulating film disposed between the capacitor electrode and the pixel electrode. The photoconductor is provided for each of a plurality of pixel electrodes,
The display medium according to claim 1, wherein the photoconductor provided for each of the plurality of pixel electrodes is disposed separately from each other for each pixel electrode.   The photoconductor is disposed in a layer between the data electrode, the pixel electrode, and the translucent substrate, and covers one surface of the translucent substrate. The display medium according to claim 1. A pixel electrode disposed on a translucent substrate having translucency;
A data electrode for supplying a data signal to be written to the pixel electrode;
The data electrode and the pixel electrode are electrically connected to the data electrode and the pixel electrode on the side of the transparent substrate from the data electrode and the pixel electrode. , When the light irradiation is stopped, a photoconductor that makes the data electrode and the pixel electrode non-conductive,
A counter electrode disposed to face the pixel electrode;
A display medium including a display layer disposed between the counter electrode and the pixel electrode and driven in accordance with a data signal written to the pixel electrode;
A display system comprising: a light irradiation means for irradiating the display medium with light. The display medium includes a capacitive electrode formed on the light-transmissive substrate side with respect to the pixel electrode,
6. The display system according to claim 5, further comprising an insulating film disposed between the capacitor electrode and the pixel electrode. Irradiation position moving means for sequentially moving the irradiation position of the display medium by the light irradiation means;
The display system according to claim 5, further comprising a data signal supply unit that supplies a data signal corresponding to the irradiated position moved by the irradiated position moving unit to the data electrode.   8. The display system according to claim 7, further comprising: a light irradiation stop unit that stops the light irradiation by the light irradiation unit during the supply of the data signal by the data signal supply unit. The light irradiation means includes a light source arranged in one direction,
The display system according to claim 5, further comprising a light guide unit that narrows light from the light source and guides the light to the display medium.   The display system according to claim 5, wherein the light irradiation unit irradiates a laser beam.

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