JP2005115307A - Display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display apparatus in which an image can be drawn by using a thin low-cost electronic paper. <P>SOLUTION: A suspension medium 6 and colored particles 7 having chargeability are sealed in a sealed space of an electronic paper 1 as a display layer covered with sheets 4, 5, and a conductive layer 2 is disposed on the lower face of the electronic paper 1. A marking device 3 having an electrode 10 at the top end and housing a battery 9 is used. When the plus electrode of the battery 9 is connected to the conductive layer 2 and the minus electrode is connected to the electrode 10 to generate a specified potential between the conductive layer 2 and the electrode 10, the colored particles 7 near the electrode 10 of the colored particles positively charged by friction or the like with the suspension medium 6 are attracted to the side of the electrode 10. By allowing the above phenomena to be visible through the sheet 4, an image can be displayed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a display device that performs drawing on electronic paper.

  Conventionally, recording and storing on paper with a writing instrument is highly convenient and generally used. However, in recent years, demands for resource saving and energy saving for increasing the global environment are increasing. Since paper consumes a large amount of energy and a large amount of water and wood at the time of production, it is considered to be preferable to suppress its use because of high environmental load. However, a display using an electrical signal such as a liquid crystal display device other than paper is not a substitute for paper in that it has poor visibility compared to paper and requires a maintenance power source to save the screen.

  Conventionally, there are an LED, a liquid crystal, a plasma, an EL display and the like as a display that can be rewritten with an electrical signal. However, in recent years, the need for saving resources and energy has been increasing for the preservation of the global environment, and displays that consume power to maintain image display are not suitable for applications such as signboards and posters.

  Various electronic papers or electronic inks have been proposed. This is a capsule in which a colored body such as a pigment is encapsulated with a dispersion medium mixed in a paper or ultrathin sheet, and the antistatic colored body appears on the surface layer only in the part where voltage is applied, and contrasts with the background part. Occurs, image formation is possible, and once the image formation is performed, a maintenance power source is unnecessary.

  As such electronic paper, for example, a method of manufacturing a display panel in which colored microcapsules are sequentially ejected and arranged on a substrate by an ink jet method has been proposed (for example, see Patent Document 1). In addition, an electronic book having a plurality of page displays in which a contrast medium is arranged on a flexible substrate (see, for example, Patent Document 2), an electrophoretic display element and an electrode printed on a substrate (for example, In addition, an electrophoretic display cell ink (see, for example, Patent Document 4) capable of two types of coloring has been proposed.

In these electronic papers, it is assumed that a control electrode is provided on the back surface of the substrate of the display unit and control is performed pixel by pixel. In this way, the presence of the control electrode on the back of the substrate increases the cost of electronic paper per sheet, and is thicker and harder than ordinary paper, making it difficult to use by taking up space for storage. There was a problem.
JP 2000-035769 A Japanese National Patent Publication No. 11-502950 Special Table 2002-520655 gazette JP 2000-290566 A

  It is an object of the present invention to obtain a display device using electronic paper that has good visibility, does not require maintenance power, and is thin and low in cost.

  Furthermore, it is an electrically rewritable display with good visibility and no maintenance power, and since it does not have a control electrode on the back surface, it is an object to obtain a large screen and high definition display at low cost.

  In order to achieve the above object, a display device according to claim 1 includes a display body layer enclosing a suspended medium and charged colored particles, and a conductive material disposed on a first surface of the display body layer. And a marking device having an electrode movable on a second surface opposite to the first surface of the display body layer.

  According to a second aspect of the present invention, in the display device according to the first aspect, a power source for generating a predetermined potential difference is provided between the conductive layer and the electrode.

  A third aspect of the present invention is the display device according to the first or second aspect, wherein the display body layer is formed by enclosing a suspension medium and colored body particles in a sealed space.

  According to a fourth aspect of the present invention, in the display device according to the first or second aspect, the display body layer is formed by encapsulating a capsule in which a suspension medium and colored body particles are encapsulated in a sealed space. Features.

  A fifth aspect of the present invention is the display device according to any one of the first to fourth aspects, wherein switching means for switching a polarity of a voltage applied to the electrode and the conductive layer is provided. Item 5. The display device according to any one of Items 1 to 4.

  A sixth aspect of the present invention is the display device according to any one of the first to fifth aspects, wherein the marking device has a power source that generates a predetermined potential difference between the conductive layer and the electrode. Features.

  A seventh aspect of the present invention is the display device according to any one of the first to sixth aspects, wherein a voltage having an opposite polarity is applied to the electrodes during drawing and erasing. To do.

  The invention according to claim 8 is the display device according to any one of claims 1 to 7, wherein the marking device has another electrode to which a voltage having a polarity opposite to that of the electrode is applied. Features.

  The invention according to claim 9 is the display device according to any one of claims 1 to 8, wherein the conductive layer is covered with an insulating sheet.

  A tenth aspect of the present invention is the display device according to any one of the first to ninth aspects, wherein the marking device has a pen shape in appearance.

  An eleventh aspect of the invention is the display device according to any one of the first to tenth aspects, wherein the display body layer is a photosensitive body in which a photosensitive body, a charging member and a writing member for the photosensitive body are integrated. The photosensitive member unit can move while being in contact with the display layer.

  A twelfth aspect of the present invention is the display device according to any one of the first to tenth aspects, wherein the photosensitive unit moves in contact with the back surface of the display body layer. The surface has a transparent conductive layer, and the transparent conductive layer and the photosensitive member are electrically connected.

  A thirteenth aspect of the invention is the display device according to any one of the first to twelfth aspects, wherein the photoconductor uses an LED array for writing to the photoconductor, and the LED array is a photoconductor unit. It is integrally formed inside.

  A fourteenth aspect of the present invention is the display device according to any one of the first to thirteenth aspects, wherein the photoconductor includes a charger that rotates in contact with the photoconductor, and the charger is The photosensitive member unit is integrally formed.

  A fifteenth aspect of the present invention is the display device according to any one of the first to eleventh aspects, wherein the display body layer forms an image by moving the colored body in the medium by electrophoresis. It is characterized by that.

  A sixteenth aspect of the present invention is the display device according to any one of the first to eleventh aspects, wherein the display layer performs image formation by rotating a minute polarized contrast ball. Features.

  From the above description, the display device of the present invention has good visibility and does not require maintenance power, and since it does not have a control electrode on the back surface, a thin, low-cost rewritable electronic paper is obtained, and dedicated marking It is possible to perform drawing with the same feeling as a writing instrument using the apparatus, and it is possible to contribute to the conservation of the global environment by conserving resources, especially paper resources. It can also be applied to electronic memos, electronic blackboards, educational toys, and the like.

  In addition, because it has good visibility and does not require maintenance power and does not have a control electrode on the back side, high-definition image formation is required to transfer the electrostatic latent image written by light to a low-cost rewritable large-screen display. Is possible.

  As a first embodiment of the present invention, a marking device having a conductive layer disposed on a surface of a display body layer in which a suspended medium and colored particles having charging properties are enclosed, and having an electrode movable on the opposite surface By providing a predetermined potential difference between the conductive layer and the electrode, display is performed by moving nearby colored particles to the electrode side.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a configuration diagram of a display device according to Embodiment 1 of the present invention.
The display device includes an electronic paper 1, a conductive layer 2 provided on the lower surface of the electronic paper 1, and a marking device 3 used as an electronic pen.

  As the display layer, the electronic paper 1 has a sealed space covered with a thin transparent or translucent sheet 4 and a sheet 5 made of acrylic, polyester, polyethylene, PET, etc., and a suspension medium 6 such as silicone oil inside. Charged colored particles 7 are enclosed. As the colored particles 7, for example, carbon black, manganese ferrite, magnetite, ferrite, and other black or dark pigments can be used.

The conductive layer 2 is made of a thin film sheet made of aluminum, nickel, or the like, or an aluminum vapor deposited mylar, and the lower surface is covered with an insulating sheet 8 so that the user does not come in contact with the electric shock.
The marking device 3 is provided with an electrode 10 at the tip of a pen-like member and a battery 9 inside as shown in the figure.

Next, the operation according to the above configuration will be described.
In a normal state, the colored body particles 7 are immersed in the suspension medium 6. At this time, the colored particles 7 are positively charged due to friction with the suspension medium 6 or the like. In this state, the negative electrode of the battery 9 of the marking device 3 is connected to the electrode 10, the positive electrode is connected to the conductive layer 2 via the electric wire 11, and the electrode 10 is brought into contact with the surface 4 a of the sheet 4. Then, a potential difference is generated between the conductive layer 2 and the electrode 10, a part of the positively charged colored particles 7 moves toward the negative electrode 10, and concentrates under the electrode 10 as shown in the figure. This can be recognized through the sheet 4. Therefore, by moving the marking device 3 freely while the electrode 10 is in contact with the sheet surface 4a, it is possible to draw an image such as a picture or a character.
Note that the potential difference between the conductive layer 2 and the electrode 10 depends on conditions such as the thickness of the electronic paper 1, but for example, about 100 V / 100 μm is required as the moving electric field of the colored particles of 0.2 to 0.3 μm. If the thickness of the electronic paper 1 is, for example, 50 μm, the potential difference is about 50V.

According to the first embodiment, since it is necessary to integrate the conductive layer 2 as the control electrode with the electronic paper 1, the electronic paper 1 can be formed at a low cost and a thin shape. In addition, the marking device 3 can be used in the same manner as a writing instrument, and the electronic paper 1 can be used as an electronic memo paper.
By appropriately selecting the viscosity and specific gravity of the suspension medium 6, the size and specific gravity of the colored body particles 7, the magnitude of the voltage, etc., the colored body particles 7 once moved to the sheet 4 side can be The display stays stable in position and can be maintained.

  In the state shown in FIG. 1, when the polarity of the voltage applied to the electrode 10 and the conductive layer 2 is reversed and a voltage having a positive polarity is applied to the electrode 10 and a negative polarity is applied to the conductive layer 2, The particles 7 move to the conductive layer 2 side and again enter the suspension medium 6. Accordingly, the displayed image is erased and the screen is whitened.

FIG. 2 shows a marking device 12 that can be used as an electronic eraser according to a second embodiment of the present invention, and the same reference numerals as those in FIG.
This marking device 12 has the shape shown in the figure, an electrode 13 having a certain area is provided on the lower surface, and a battery 14 is provided therein.

In the above configuration, when the positive electrode of the battery 14 is connected to the electrode 13 and the negative electrode of the battery 14 is connected to the conductive layer 2 through the electric wire 15, the colored particles 7 gathered under the electrode 13 move downward. Then, since the image enters the suspension medium 6, the image displayed so far can be erased.
As described above, according to the second embodiment, it is possible to repeatedly use the electronic paper 1 for drawing and erasing, which contributes to resource saving, particularly to conservation of forest resources, compared to the case of using paper. it can.

In FIG. 1 of the first embodiment, if the polarity of the battery 9 is reversed, the marking device 3 can be used as an erasing marking device. Therefore, by providing means for switching the polarities of the batteries 9 and 14 of the marking devices 3 and 12 shown in FIGS. 1 and 2, a marking device that also serves as writing / erasing can be realized.
1 and 2, the batteries 9 and 14 are built in the marking devices 3 and 12, but the batteries may be provided outside the marking device.

FIG. 3 shows a display device according to Embodiment 3 of the present invention.
The electronic paper 21 is sealed with a thin transparent or translucent sheet 22 and a sheet 23, and a large number of minute capsules 24 are enclosed therein. In the capsule 24, colored particles 26 made of a suspension medium 25 and a chargeable pigment are enclosed.
A conductive layer 28 having an insulating sheet 27 is disposed on the lower surface of the electronic paper 21.
The marking device 29 is provided with a writing electrode 30 and an erasing electrode 31 at both ends of the pen-like member, and batteries 32 and 33. The batteries 32 and 33 are connected to the conductive layer 28 via electric wires 34.

  According to the above configuration, the electrode 30 is brought into contact with the sheet 22 to apply a negative voltage, and a positive voltage is applied to the conductive layer 28, so that the colored particles 26 in the capsule 24 in the vicinity of the electrode 30 are brought near the electrode 30. Collected images are displayed. Further, when the electrode 31 is brought into contact with the sheet 22 and a positive voltage is applied, and a negative voltage is applied to the conductive layer 28, the colored particles 26 in the capsule 24 gathered on the surface sink into the suspension medium 25. The image is erased.

  According to the third embodiment, since the colored body particles 26 are enclosed in the capsule 24, the colored body particles 26 in the capsule 24 used for image display can be more stably held in a display state, and visibility is improved. Can be improved. Further, drawing and erasing can be performed by one marking device 29.

FIG. 4 shows a display device used as an electronic blackboard according to Embodiment 4 of the present invention.
In FIG. 4, an electronic paper 41 having the same configuration as that of the first or third embodiment is formed in a belt shape, is spanned between the shaft rollers 42 and 43, and is movable with the rotation of the shaft rollers 42 and 43. Then, the image is drawn on the electronic paper 41 using the marking device 44 having the same configuration as that of the first embodiment. Further, an erasing electrode 45 as the marking device 12 of the second embodiment is provided as a blackboard eraser. Further, a roller-shaped erasing electrode 46 is provided at the end of the electronic paper 41 so that when the electronic paper 41 moves, the image is erased when the screen passes through the roller-shaped erasing electrode 46.
Note that the marking device 44 may also serve as drawing / erasing as described above.
In this way, it is possible to realize an electronic blackboard that performs drawing on electronic paper in the same manner as using a writing instrument.

FIG. 5 shows a display device used as an educational toy for electronic drawing according to Embodiment 5 of the present invention.
In FIG. 5, an electronic paper 51 having the same configuration as that of the first embodiment is provided on a plate member 50, and the electronic paper 51 can be drawn using a marking device 52. Further, an erasing electrode member 53 is provided at the end of the plate member 50 so as to be able to move on the electronic paper 51, so that the image can be erased. Although not shown, the plate material 50 is provided with a conductive layer.
In this way, it is possible to realize an educational toy for electronic drawing that draws on electronic paper with the same feeling as using a writing instrument.

Next, a second embodiment of the present invention will be described.
An image display body in which an electrically controllable colored body is encapsulated, a photoconductor and a photoconductor unit in which a charging member and a writing member for the photoconductor are integrated, and the photoconductor unit moves while contacting the surface itself. By doing so, image formation is performed. In this way, the electrostatic latent image written on the photosensitive member is transferred to the image display member, enabling high-definition image formation of about 600 dots / inch, increasing the width direction of the photosensitive member, By taking a long time, it becomes possible to easily handle large screens. In this way, a high-definition, large-screen display that can be rewritten without using maintenance power during image display is possible.

  The photosensitive unit is brought into contact with and moved from the rear surface of the display body. The display body surface has a transparent conductive layer, and the transparent conductive layer and the photosensitive substrate are electrically connected. FIG. 6 shows an outline of this display device, and FIG. 7 shows a sectional view during image formation.

  The photosensitive unit 102 moves in the direction of arrow A along a guide (not shown) on the back surface of the display layer. After the photoconductor 120 is uniformly charged, optical writing is performed by the writing unit 122 to form an electrostatic latent image. Then, the image transfer unit contacts the display body layer 100 to transfer the latent image to the display body.

  The photoconductor after the latent image is transferred is neutralized by the neutralizing lamp 123 as necessary, the potential is leveled, and it is used again for charging. FIG. 7 shows a state in which the photoconductor 120 is positively charged, the non-image portion is exposed to erase the charge, and the charge remains only in the image portion. When the photosensitive member 120 comes into contact with the back surface of the display body in the latent image transfer portion, the positive electro-resistant colored particles 110 in the opaque medium 111 are repelled in the image portion and appear on the display surface.

  In the non-image area, the colored particles 110 remain in the lower part of the opaque medium 111 and are not recognized from the surface. In this way, contrast is generated and image formation becomes possible. At this time, the transparent electrode 112 on the surface of the display layer and the photosensitive substrate are electrically connected by the conductive line 126, so that an electric field necessary for moving the colored particles is formed. In this way, a rewritable high-definition display that can handle a large screen and does not require maintenance power can be obtained.

  An LED array formed integrally with the photoconductor unit is used for optical writing on the photoconductor. In this way, as shown in FIG. 7, the photosensitive member rotating shaft 124 and the LED array unit 122 can be integrally formed to fix the irradiation position of the LED light, and the photosensitive member unit moves while rotating. This makes it possible to prevent the writing position from being shifted due to vibrations. In this way, it is possible to deal with a large screen, and a rewritable, high-definition display that does not require maintenance power can be obtained.

  For charging the photoreceptor, a contact rotating charger integrally formed with the photoreceptor unit is used. In this way, as shown in FIG. 7, the photosensitive member rotating shaft 124 and the charger rotating shaft 125 are integrally formed, and the contact width and contact pressure of the charging roller or charging brush can be fixed. Further, it is possible to prevent uneven charging due to vibration when the photosensitive unit moves while rotating. In this way, it is possible to deal with a large screen, and a rewritable, high-definition display that does not require maintenance power can be obtained.

  The image display layer is such that the colored body moves through the medium by electrophoresis. In this way, the colored body quickly moves due to the potential difference caused by the contact of the electrostatic latent image formed on the photoreceptor, and the maintenance power is applied to the once displayed image by making the specific gravity of the colored body and the medium the same. It becomes useless. In this way, a rewritable high-definition display that can handle a large screen and does not require maintenance power can be obtained.

  The image display layer is configured to perform image formation by rotating a minute polarized contrast ball. In this way, the contrast ball quickly rotates 180 degrees to form an image due to the potential difference caused by the contact of the electrostatic latent image formed on the photoconductor, and the image once displayed becomes stable and does not require maintenance power. . In this way, it is possible to deal with a large screen, and a rewritable and high-definition display that does not require maintenance power can be obtained.

  FIG. 6 is a display using the present invention. The display includes an image display layer 100 and a photosensitive unit moving unit 101 on the back. FIG. 8 shows a cross-sectional configuration diagram of this image display device. The photosensitive unit moves in the direction A at a line side of 100 mm / sec. A charging roller 121 formed of a semiconductive urethane rubber layer is pressed against the photoconductor 120 to apply a bias to charge the photoconductor surface to + 500V.

  Then, exposure is performed at a resolution of 600 dpi by the LED array unit 122, and the potential of the non-image portion is lowered to + 50V. In the image transfer portion, the colored particles are moved by the potential difference between the transparent electrode 112 on the surface of the display layer and the photosensitive member in contact with the display layer 100 to form an image.

  The display layer has a structure in which colored particles 131 for electrophoresis are enclosed in a medium 132 in a microcapsule 130. The material of the capsule 130 was formaldehyde urea cross-linked resin having a diameter of 40 μm, a positively charged dark pigment was used as the electrophoretic particles 131, and the electrophoretic medium 132 was prepared by adjusting the specific gravity of Isopar G with tetrachloroethylene.

  The capsules were dispersed and fixed on the sheet by the binder 133 of Byron 200. The display layer was created with a length of 1 m and a width of 2 m. The width of the photoconductor was set to 1 m, and the photoconductor was arranged vertically and moved by 2 m from the back surface of the display layer. In this way, a rewritable high-definition display having a large screen and requiring no maintenance power was obtained.

  In Example 7, the display has the same configuration as that of Example 6, but an image display layer encapsulating a polarized contrast ball 140 as shown in FIG. 9 is used. The black side 141 contains an oxide pigment and the white side 142 contains a titanium-based pigment, which is precharged in a corona discharge dipole.

  The charged contrast balls are applied in the form of a film using silicon resin as a binder 143. A minute gap filled with dielectric liquid isopar V is formed around the particles, thereby enabling smooth rotation of the contrast ball 140. Such a display layer was formed on a large screen similar to that of Example 6, and a rewritable high-definition display that did not require maintenance power was obtained.

  Although the display has the same configuration as that of Example 6, titanium microparticles coated with low density polyethylene are used as the white migrating particles 131 in the microcapsule as shown in FIG. Were mixed. In such a case, image formation is performed with the portion where the particle is exposed on the surface being white, and when the particle is submerged, black. Such a display layer is formed on a large screen similar to that of the first embodiment, and a rewritable high-definition display that does not require maintenance power can be obtained.

  The display has the same configuration as that of Example 6, but a negatively charged organic photoreceptor is used as the photoreceptor. Then, after uniformly charging the surface of the photoreceptor to −500 V, only the non-image area was exposed to reduce the potential to −50 V. As an image display pair, negatively charged carbon fine particles were enclosed in the microcapsule of FIG. 8 to form an image. Such a display layer was formed on a large screen similar to that in Example 1, and a rewritable high-definition display without requiring maintenance power was obtained.

It is a block diagram which shows the display apparatus by Example 1 of this invention. It is a block diagram which shows the display apparatus by Example 2 of this invention. It is a block diagram which shows the display apparatus by Example 3 of this invention. It is a block diagram which shows the display apparatus used as an electronic blackboard by Example 4 of this invention. It is a block diagram which shows the display apparatus used as an electronic educational toy by Example 5 of this invention. 1 is a schematic view of a display device according to the present invention. 1 is a schematic cross-sectional view of a display device according to the present invention. 1 is a schematic cross-sectional view of a display device according to the present invention. 1 is a schematic cross-sectional view of a display device according to the present invention.

Explanation of symbols

1, 21 Electronic paper 2, 28 Conductive layer 3, 12, 29 Marking device 6, 25 Suspension medium 7, 26 Colored particles 8, 27 Insulating sheet 9, 14, 32, 33 Battery 10, 13, 30 Electrode 24 Capsule DESCRIPTION OF SYMBOLS 100 Image display layer 101 Photoconductor unit moving part 102 Photoconductor unit 110 Colored particle 111 Opaque medium 112 Transparent electrode 120 Photoconductor 121 Charging roller 122 LED array unit 123 Static elimination lamp 124 Photoconductor rotating shaft 125 Charger rotating shaft 126 Conductive line 130 Microcapsule 131 Electrophoretic particle 132 Medium 133, 143 Binder 140 Contrast ball 141 Black side 142 White side

Claims (16)

A display body layer in which suspended particles and colored particles having charging properties are enclosed;
A conductive layer disposed on the first surface of the display layer;
A display device comprising a marking device having an electrode movable on a second surface opposite to the first surface of the display body layer.   The display device according to claim 1, further comprising a power source that generates a predetermined potential difference between the conductive layer and the electrode.   The display device according to claim 1, wherein the display body layer is formed by sealing the suspension medium and the colored body particles in a sealed space.   The display device according to claim 1, wherein the display body layer is formed by sealing a capsule in which the suspension medium and the colored body particles are sealed in a sealed space.   The display device according to claim 1, further comprising a switching unit that switches a polarity of a voltage applied to the electrode and the conductive layer.   The display device according to claim 1, wherein the marking device has a power source that generates a predetermined potential difference between the conductive layer and the electrode.   The display device according to claim 1, wherein a voltage having a reverse polarity is applied to the electrode at the time of drawing and at the time of erasing.   The display device according to claim 1, wherein the marking device includes another electrode to which a voltage having a polarity opposite to that of the electrode is applied.   The display device according to claim 1, wherein the conductive layer is covered with an insulating sheet.   The display device according to claim 1, wherein the marking device has a pen shape in appearance.   The display layer includes a photoconductor unit in which a photoconductor and a charging member and a writing member for the photoconductor are integrated, and the photoconductor unit can move while being in contact with the display layer. The display device according to claim 1, wherein the display device is a display device.   The photoconductor unit moves in contact with the back surface of the display body layer, the surface of the display body layer has a transparent conductive layer, and the transparent conductive layer and the photoconductor are electrically connected. The display device according to claim 1, wherein the display device is a display device.   13. The device according to claim 1, wherein the photoconductor uses an LED array for writing to the photoconductor, and the LED array is integrally formed in the photoconductor unit. Display device.   14. The photoreceptor according to claim 1, wherein the photoreceptor has a charger that rotates in contact with the photoreceptor, and the charger is integrally formed in the photoreceptor unit. The display device described in 1.   The display device according to claim 1, wherein the display body layer forms an image by moving a colored body in a medium by electrophoresis.   The display device according to claim 1, wherein the display body layer forms an image by rotating a polarized minute contrast ball.

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