JP2008112082A - Image display medium and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance adhesion strength of color particles to a substrate and to improve retention property of a display screen. <P>SOLUTION: A dispersion liquid 24 having light transmitting property is sealed between a display substrate 18 and a back substrate 28, as well as colored particles 32 that move according to an electric field generated between the substrates are sealed. A charging layer 34 having charging characteristics that positive and negative polarities can be alternately exchanged according to the electric field generated between the substrates is provided between the back substrate and the region where the color particles 32 are sealed so as to enhance the adhesion strength of the color particles 32 to the substrate by the charging characteristics of the charging layer 34. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image display medium and an image display device.

  2. Description of the Related Art Conventionally, an image display medium using colored particles is known as an image display medium that has memory characteristics and can be rewritten repeatedly. Such an image display medium includes, for example, a pair of substrates and a plurality of types of colored particles that are sealed between the substrates so as to be movable between the substrates by an applied electric field and have different colors and charging characteristics. Is done. In addition, a gap member for partitioning the substrates into a plurality of cells may be provided between the substrates for reasons such as preventing the colored particles from being biased to a partial region in the substrates.

  In such an image display medium, the colored particles are moved by applying a voltage according to the image between the pair of substrates, the image is displayed as the contrast of the colored particles of different colors, and the voltage application is stopped. The colored particles remain attached to the substrate by van der Waals force or mirror image force, and the image display is maintained. However, it cannot be said that the adhesion force between the colored particles and the substrate due to these forces is sufficiently large, and there is a problem that the colored particles are not gradually peeled off from the substrate due to vibration or time, and the display quality of the image is gradually deteriorated. there were.

  As an image display medium that solves such a problem, for example, the techniques described in Patent Documents 1 to 3 have been proposed. In the Patent Document, various methods for increasing the adhesion of colored particles to a substrate have been proposed. ing.

  In the technique described in Patent Document 1, an image display medium in which colored particles are dispersed in a dispersion medium that causes a solid-liquid phase change depending on temperature is proposed, and the colored particles are driven by heating the dispersion medium to liquefy. After the display, the dispersion medium is solidified by natural cooling to fix the colored particles.

  In the technique described in Patent Document 2, an image display medium is proposed in which an adhesive layer is provided on the substrate surface to increase the adhesion between the colored particles and the substrate surface.

In the technique described in Patent Document 3, a charged film such as a ferroelectric substance or an electret having a charge opposite to that of the colored particles is formed on the substrate surface, and coloring is performed using electrostatic attraction by the charged film. An image display medium in which the adhesion between the particles and the substrate surface is increased has been proposed.
JP 2002-365670 A JP 2000-259102 A JP 2000-258805 A

  An object of the present invention is to improve the retention of a display image by reliably increasing the adhesion of colored particles to a substrate without a secondary obstacle by a method different from the prior art.

  In order to achieve the above object, the invention according to claim 1 is characterized in that at least one of the pair of substrates has translucency, and is sealed between the substrates, and moves according to an electric field formed between the substrates. One or more types of colored particles are provided adjacent to the region where the colored particles are enclosed between the substrates, and the polarity of the positive and negative can be alternately switched according to the electric field formed between the substrates. And a charging layer having excellent charging characteristics.

  According to a second aspect of the present invention, in the first aspect of the present invention, the medium in the region where the colored particles are moved between the substrates is a gas or a liquid having translucency.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the charging layer includes a charging unit in which positive and negative polarities can be alternately switched, and the charging unit has a unit pixel size. It is characterized by being smaller than this.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, a part of the charging layer deviating from the center of gravity is positively charged, and the remaining part is negative. It is characterized by comprising a plurality of rotating bodies that are charged and rotated according to the electric field formed between the substrates.

  According to a fifth aspect of the present invention, in the first aspect of the invention according to any one of the first to third aspects, the charging layer is a positively charged first material dispersed in a solvent having an insulating property. It is characterized by comprising a plurality of electrophoretic capsules containing particles and negatively charged second particles.

  The invention according to claim 6 is the invention according to claim 5, wherein the viscosity of the solvent having the insulating properties of the electrophoretic capsule is made higher than the medium viscosity in the region where the colored particles move between the substrates. It is characterized by that.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein a medium in a region where the colored particles are moved between the substrates has a color different from that of the colored particles. It is characterized by being a colored liquid.

  The invention according to claim 8 is the invention according to any one of claims 1 to 6, wherein a color different from that of the colored particles is provided between the charged layer and a region in which the colored particles are enclosed. It is further characterized by further comprising a colored reflecting surface.

  The invention according to claim 9 is the invention according to any one of claims 1 to 6, wherein the charged layer is colored in a color different from the colored particles.

  The invention described in claim 10 is characterized in that, in the invention described in any one of claims 1 to 6, the colored particles are provided with two or more types having different colors and charging characteristics.

  According to the eleventh aspect of the present invention, at least one of the pair of translucent substrates is sealed between the substrates, and moves in a direction intersecting the inter-substrate direction in accordance with an electric field formed between the substrates. , Provided adjacent to a region where the colored particles between the colored substrate and the colored particles between the substrates are enclosed, a part off the center of gravity is positively charged, the remaining part is negatively charged, and A charged layer including a plurality of rotating bodies that are colored in the same color system as the colored particles and are rotated according to an electric field formed between the substrates. It is a feature.

  According to the twelfth aspect of the present invention, at least one of the pair of substrates having translucency and the substrate is sealed between the substrates and moved according to the electric field formed between the substrates, and the color and the charging characteristics are different. Provided adjacent to the region where the colored particles of the type or more and the colored particles between the substrates are encapsulated, a part off the center of gravity is positively charged, the remaining part is negatively charged, and the 2 A charged portion including a plurality of rotating bodies in which a portion charged with the same polarity as any one of the colored particles is colored in the same color system as the colored particles and rotated according to an electric field formed between the substrates. And a layer.

  According to the thirteenth aspect of the present invention, at least one of a pair of light-transmitting substrates and a substrate that is sealed between the substrates and moves according to an electric field formed between the substrates are different in color and charging characteristics. Provided adjacent to the region where the colored particles of the type or more and the colored particles between the substrates are encapsulated, a part off the center of gravity is positively charged, the remaining part is negatively charged, and the 2 A charged layer including a plurality of rotating bodies that are rotated in accordance with an electric field formed between the substrates, in which a portion charged to a polarity different from any one of the colored particles is colored in a complementary color system of the colored particles It is characterized by providing these.

  According to a fourteenth aspect of the present invention, the image display medium according to any one of the first to thirteenth aspects, a voltage applying unit that applies a voltage between the substrates, and the voltage application according to image information. And a control means for controlling the means.

  According to the first aspect of the present invention, the adhesion force of the colored particles to the substrate can be increased by electrostatic attraction force or electrostatic repulsion force. According to the second aspect of the present invention, it is possible to increase the adhesion of the colored particles to the substrate by moving the colored particles according to the electric field formed between the substrates.

  According to the third aspect of the present invention, the adhesion force of the colored particles to the substrate can be increased, and the image can be held faithfully to the display image.

  In the invention according to claim 4, the charged layer can be formed at a low cost by a known production method.

  According to the fifth aspect of the present invention, the charged layer can be formed at low cost by a known manufacturing method, and the charged layer can be manufactured without worrying about the positional relationship with the pixel.

  According to the sixth aspect of the present invention, the maintainability of the adhesion force of the colored particles to the substrate can be enhanced.

  According to invention of Claim 7, it becomes possible to display colors other than the color of a colored particle.

  According to invention of Claim 8, it becomes possible to display colors other than the color of a colored particle.

  According to invention of Claim 9, it becomes possible to display colors other than the color of a colored particle.

  According to the invention described in claim 10, it is possible to display two or more colors.

  According to the eleventh aspect of the present invention, it is possible to improve the color development when displaying the color of the colored particles.

  According to invention of Claim 12, the color development at the time of displaying the color of a colored particle can be improved.

  According to the thirteenth aspect, color mixing can be prevented.

  According to the fourteenth aspect of the present invention, the movement of the colored particles and the polarity of the charged layer can be controlled by controlling the voltage applied between the substrates, whereby the colored particles are attached to the substrate. Image display with increased wearing force can be performed.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. In addition, about the member which has the substantially same function, the same code | symbol may be attached | subjected through all the drawings and the overlapping description may be abbreviate | omitted.

(First embodiment)
FIG. 1 is a schematic configuration diagram showing an image display apparatus according to the first embodiment of the present invention, and shows a case where all colored particles are moved to the back substrate side.

  As shown in FIG. 1, an image display apparatus 10 according to an embodiment of the present invention is configured such that a transparent substrate 16 is formed on a transparent support substrate 14 and is opposed to the display substrate 18 with a gap. A rear substrate 28 in which a plurality of electrodes 22A, 22B, 22C (hereinafter may be referred to as electrodes 22) are formed on a support substrate 26, a gap member 30 that partitions the substrates into a plurality of cells, It has the image display medium 12 comprised by these.

  In addition, the cells formed between the display substrate 18 and the back substrate 28 are colored in a predetermined color and have colored particles 32 having a predetermined charging characteristic, and a transparent liquid 24 (transparent). Liquid) are encapsulated, and these are electrophoresed between the substrates by an electric field formed between the substrates.

  In the present embodiment, for example, colored particles 32 that are colored black can be applied, and the color is not limited to this. The colored particles 32 generally have a volume average particle size of 0.01 μm to 10 μm, preferably 0.03 μm to 3 μm, but are not limited thereto. If the volume average particle diameter of the colored particles 32 is smaller than the above range, the charge amount of the colored particles 32 is decreased, and the moving speed in the dispersion liquid 24 may be decreased. That is, display responsiveness may deteriorate. On the contrary, if the volume average particle size of the colored particles 32 is larger than the above range, the followability is good, but precipitation due to its own weight and a decrease in memory performance may easily occur.

  The light-transmitting dispersion liquid 24 is preferably a colorless and transparent liquid having insulating properties. For example, hydrocarbon solvents such as silicon, toluene, xylene, inparaffin, and normal paraffin can be used. In this embodiment, a liquid is applied as the dispersion liquid 24, but various gases such as air may be applied instead of the dispersion liquid 24.

  The transparent electrode 16 and the electrodes 22A, 22B, and 22C are connected to the voltage application unit 40, respectively. That is, an electric field is formed between the substrates by applying a voltage to the transparent electrode 16 and the electrodes 22A, 22B, and 22C by the voltage application unit 40. The transparent electrode 16 and the electrodes 22A, 22B, and 22C may be separated from the display substrate 18 and the back substrate 28 and disposed outside the image display medium 12, respectively.

  The voltage application unit 40 is connected to a control unit 42, and an image storage unit 44 is connected to the control unit 42.

  The control unit 42 includes a CPU, a ROM, a RAM, a hard disk, and the like. The CPU displays an image on the image display medium 12 according to a program stored in the ROM, the hard disk, or the like. The image storage unit 44 is configured by a hard disk or the like, and stores a display image for displaying an image on the image display medium 12. That is, the control unit 42 controls the voltage application unit 40 according to the display image stored in the image storage unit 44 to apply a voltage between the substrates, so that the colored particles 32 move according to the voltage and the image is displayed. Is displayed. The display image stored in the image storage unit 44 may be taken into the image storage unit 44 via various recording media such as a CD-ROM and a DVD and a network.

  Furthermore, in the image display apparatus 10 according to the first embodiment of the present invention, the surface on the back substrate 28 side in the cell formed between the display substrate 18 and the back substrate 28 constituting the image display medium 12, that is, A charged layer 34 whose polarity changes according to the voltage applied between the transparent electrode 16 and the electrode 22 is provided in a portion adjacent to the region where the colored particles 32 are enclosed.

  The charged layer 34 encloses spherical large-diameter particles 36 larger than the colored particles 32. The large-diameter particles 36 are at least partially charged from the center of gravity and charged with a negative polarity, and the remainder is negatively charged, and the polarity changes by rotating according to the electric field formed between the substrates. . The charged layer 34 is filled with a liquid having a predetermined viscosity so that the large-diameter particles 36 are rotated and maintained in this state. In the present embodiment, the capsule 38 has a predetermined viscosity. Liquid and large-diameter particles 36 are enclosed. The charged layer 34 holds the colored particles 32 on the substrate by repelling the colored particles 32 to the display substrate 18 side by the positive and negative charging portions of the large-diameter particles 36 or sucking the colored particles 32 to the back substrate 28 side. It is designed to assist in power.

  In the present embodiment, spherical particles are applied to the large-diameter particles 36, but the present invention is not limited to this, and various rotating particles can be applied. In the present embodiment, the large-diameter particle 36 has a charging characteristic in which one hemisphere is positively charged and the other hemisphere is negatively charged, and is rotated by applying a voltage between the transparent electrode 16 and the electrode 22. It will be described as being.

  In the present embodiment, the size of the charged portion where the polarity of the charging layer 34 changes, that is, the size of the large-diameter particle 36 is set smaller than the size of the unit pixel (electrodes 22A, 22B, 22C) of the display image. However, it is preferable that at least one or more positive and negative charged portions (large-diameter particles 36) alternately arranged are arranged in one unit pixel.

  The large particle 36 can be formed at a low cost by a known production method, and a layer can be formed by a coating process in a form dispersed in a resin. For example, particles in which a white pigment such as titanium oxide, silicon oxide, or zinc oxide is dispersed in polystyrene, polyethylene, polypropylene, polycarbonate, PMMA, acrylic resin, phenol resin, formaldehyde condensate, or the like may be used. As for colors, for example, general pigments or dyes used in printing inks and color toners can be used for white, black, RGB, and YMC colors. In order to enclose the large-diameter particles 36 between the substrates, for example, an electrophotographic method or a toner jet method is used. The details of each member constituting the image display medium 12 may be those described in Japanese Patent Application Laid-Open No. 2001-3225, for example.

  In addition, the colored particles 32 and the large-diameter particles 36 are maintained in a state where a voltage is applied by van der Waals force, mirror image force, or the like even after the application of the voltage between the substrates is stopped. In particular, since the large-sized particles 32 have a large adhesion area (contact area) with the capsule wall surface and a large adhesion force, they hardly vibrate or rotate with time.

  Next, an example of display drive control of the image display apparatus 10 according to the first embodiment of the present invention configured as described above will be described. The charging characteristics of the colored particles 32 are positively charged as described above.

  When the voltage application unit 40 applies a voltage so that the back substrate 28 side is negative (display substrate 18 side applied voltage> back substrate 28 side applied voltage) between the transparent electrode 16 and the electrode 22 under the control of the control unit 42, FIG. As shown, the positively charged colored particles 32 are moved to the back substrate 28 side. Further, the large-diameter particles 36 of the charging layer 34 have their positively charged hemisphere rotated to the back substrate 28 side and negatively charged hemisphere to the display substrate 18 side. That is, the negatively charged hemispherical surface of the large-diameter particle 36 and the positively charged colored particle 32 face each other, and the holding force of the colored particle 32 on the back substrate 28 side is improved by the electrostatic attractive force.

  Further, under the control of the control unit 42, the voltage application unit 40 applies a voltage between the transparent electrode 16 and the electrodes 22 </ b> A and 22 </ b> C so that the back substrate 28 side is positive (display substrate 18 side applied voltage <back substrate 28 side applied voltage). In addition, when a voltage is applied between the transparent electrode 16 and the electrode 22B so that the back substrate 28 side is negative, as shown in FIG. 2, the positively charged colored particles 32 are formed in the regions corresponding to the electrodes 22A and 22C. The large-diameter particles 36 of the charging layer 34 corresponding to the region are moved to the display substrate 18 side, and the positively charged hemisphere is rotated to the display substrate 18 side, and the negatively charged hemisphere is rotated to the back substrate 28 side. The Further, in the region corresponding to the electrode 22B, the positively charged colored particles 22 are moved to the back substrate 28 side, and the large-diameter particles 36 of the charging layer 34 corresponding to the region have the positively charged hemisphere as the back substrate. On the 28th side, the negatively charged hemisphere is rotated to the display substrate 18 side.

  Accordingly, in the region corresponding to the electrode 22B, the negatively charged hemispherical surface of the large-diameter particle 36 and the positively charged colored particle 32 face each other, and the colored particle 32 moves toward the back substrate 28 side by electrostatic attraction. In the region corresponding to the electrodes 22A and 22C, the positively charged hemisphere of the large-diameter particle 36 and the positively-charged colored particle 32 face each other in the region corresponding to the electrodes 22A and 22C. The holding force of the colored particles 32 to the display substrate 18 side is improved by the repulsive force.

  On the other hand, the size of the large-diameter particles 36 corresponds to the resolution at which the colored particles 32 are held on the substrate. Therefore, the outline of the display image is maintained even if it is larger than the size of the pixels, but thin lines and small dots Such as image retention is reduced. For example, when the size of the large-diameter particles 36 is two pixels of the display image, the retention of the colored particles 32 on the substrate is maintained at half the resolution of the display image. Therefore, as in the present embodiment, if the size of the large particle 36 is smaller than the size of the pixel, a sharp image can be held. Furthermore, if the size of the large particle 36 is extremely smaller than the size of the pixel, or if the large particle 36 is disposed in the unit pixel (for each electrode 22) as shown in FIG. It is possible to hold an image. Further, when the size of the large particle 36 is extremely smaller than the size of the pixel, the image display medium can be manufactured without worrying about the positional relationship of the pixel of the large particle 36.

  In the present embodiment, the holding force of the colored particles 32 to the substrate is improved by the spherical large-diameter particles 36. However, as described above, the large-diameter particles 36 have a large adhesion area with the capsule wall surface, and thus the adhesion force. Because it is strong, it is strong against impact. Therefore, an electric field is formed by applying a voltage between the substrates, and the spherical large-diameter particles 36 are rotated, so that the state of the large-diameter particles 36 is maintained as it is even when the power is turned off. The retainability to the substrate can be improved.

  In the above embodiment, the charging layer 34 is not limited to the one composed of the large-diameter particles 36. For example, as shown in FIG. 4, the charged layer 34 is filled with a liquid in a capsule (a solvent having insulating properties). Alternatively, an electrophoretic capsule 48 in which the electrophoretic particles 46 are enclosed in the capsule may be applied. In this case, the electrophoresis capsule 48 encloses the positively charged electrophoretic particles 46A and the negatively charged electrophoretic particles 46B dispersed in a solvent having insulating properties. For example, as shown in FIG. 4, the electrophoretic particles 46A and 46B enclosed in the electrophoretic capsule 48 may enclose colored particles colored white or black, or may be transparent. However, colored particles of other colors may be encapsulated. The electrophoresis capsule 48 is formed at a low cost by a known manufacturing method, and the layer can be easily formed by a coating process in a form dispersed in a resin. Here, as an advantage of the electrophoretic capsule 48, since the electrophoretic particles 46 contained in the capsule serve as the minimum unit of the charging unit, not the minimum unit of the positive and negative charging units in which the capsules are alternately switched, the charging unit and the pixel. The image display medium can be manufactured without worrying about the positional relationship.

  In addition, when the electrophoretic capsule 48 shown in FIG. 4 is applied as the charging layer 34, it is preferable to set the viscosity of the liquid in the capsule higher than the medium viscosity of the dispersion liquid 24. As a result, the migration resistance of the electrophoretic particles 46 in the electrophoretic capsule 48 increases, so that the colored particles 32 are held on the substrate by the electrophoretic capsule 48 compared to the case where the viscosity of the dispersion liquid 24 is set higher. Sexuality can be increased. In this case, since the migrating speed of the migrating particles 46 in the electrophoretic capsule 48 is slowed down, the image display speed may be lowered. First, a predetermined voltage is applied between the substrates to display a display image. Later, it is possible to cope with a driving method such as applying a voltage for moving the colored particles 46 of the electrophoretic capsule 48 of the charging layer 34 to drive the charged particles 34 slower than the display speed.

  Further, in the above embodiment, a transparent liquid is applied as the dispersion liquid 24. However, the present invention is not limited to this. For example, as shown in FIG. When the dispersion liquid 25 is applied and the colored particles 32 are moved to the back substrate 28 side, the color of the dispersion liquid 25 may be displayed.

(Second Embodiment)
Next, an image display apparatus according to the second embodiment of the present invention will be described. FIG. 6 is a schematic configuration diagram showing an image display apparatus according to the second embodiment of the present invention.

  In the image display medium 12 according to the first embodiment, the colored particles 32 are moved in the direction between the substrates. In the second embodiment, the colored particles 32 are moved in a direction intersecting with the direction between the substrates. Is.

  In the image display medium 12 according to the second embodiment, as shown in FIG. 6, two electrodes on the back substrate 28 side are provided in one cell, and the charging layer 34 is colored on the display substrate 18 side. The reflective surface 33 colored in a predetermined color (for example, white) different from the particles 32 is provided, and when the colored particles 32 are retracted from the reflective surface 33, the reflective surface 33 colored from the display substrate 18 side. Since the other colors are the same as those of the first embodiment, detailed description thereof is omitted.

  Here, an example of display drive control of the image display apparatus according to the second embodiment will be described. The charging characteristics of the colored particles 32 are assumed to be positively charged as in the first embodiment.

  When the voltage application unit 40 applies voltage so that the back substrate 28 side is negative (display substrate 18 side applied voltage)> back substrate 28 side applied voltage) between the transparent electrode 16 and the electrodes 22A and 22B by the control of the control unit 42. As shown in FIG. 6A, the positively charged colored particles 32 are moved to the back substrate 28 side. Further, the positively charged hemisphere of the large-diameter particles 32 of the charging layer 34 is rotated to the back substrate 28 side, and the negatively charged hemisphere is rotated to the display substrate 18 side. That is, the negatively charged hemispherical surface of the large-diameter particle 36 and the positively charged colored particle 32 face each other, and the holding force of the colored particle 32 on the back substrate 28 side is improved by the electrostatic attractive force.

  Further, under the control of the control unit 42, the voltage application unit 40 applies a voltage between the transparent electrode 18 and the electrode 22A so that the back substrate 28 side is negative (display substrate 18 side applied voltage)> back substrate 28 side applied voltage). At the same time, when a voltage is applied between the transparent electrode 18 and the electrode 22B so that the back substrate 28 side is positive, as shown in FIG. 6B, the positively charged colored particles 32 are on the back substrate 28 side and the electrode 22A direction. The reflecting surface 33 provided on the display substrate 18 side of the charging layer 34 can be observed from the display substrate 18 side, and a colored predetermined color (for example, white) is displayed. Further, the large-diameter particles 36 of the charging layer 34 corresponding to the electrode 22A are rotated positively on the back substrate 28 side and negatively charged hemisphere on the display substrate 18 side, and correspond to the electrode 22B. The positively charged hemisphere of the large-diameter particles 36 of the charging layer 34 is rotated to the display substrate 18 side, and the negatively charged hemisphere is rotated to the back substrate 28 side. That is, the negatively charged hemispherical surface of the large-diameter particle 36 and the positively charged colored particle 32 face each other, and the holding force of the colored particle 32 on the back substrate 28 side is improved by the electrostatic attractive force. Further, the state after the colored particles 32 are moved is also maintained by the repulsive force from the portion where the positive hemisphere of the large-diameter particles 36 of the charging layer 34 is rotated toward the display substrate 18 side.

  In the second embodiment, a voltage is applied between the transparent electrode 16 and the electrodes 22A and 22B. However, the present invention is not limited to this, and the configuration in which the transparent electrode 16 is omitted is provided between the electrodes 22A and 22B. A voltage may be applied.

  In the second embodiment, the reflective surface 33 provided on the display substrate 18 side of the charging layer 34 is colored in a color different from that of the colored particles 32, and the colored particles 32 are retracted in a direction intersecting the inter-substrate direction. Thus, the color of the surface is displayed. However, the present invention is not limited to this. For example, as shown in FIGS. 7A and 7B, the surface of the charging layer 34 on the display substrate 18 side is transparent. In addition, large-diameter particles 35 colored in a different color from the colored particles 32 may be used as the charging layer 34. Thus, when the colored particles 32 are retracted, the color of the large-diameter particles 35 can be observed from the display substrate 18 side as shown in FIG. 7B, and the color of the large-diameter particles 35 is displayed. Can be made.

(Third embodiment)
Subsequently, an image display apparatus according to a third embodiment of the present invention will be described. FIG. 8 is a schematic configuration diagram showing an image display apparatus according to the third embodiment of the present invention.

  In the first embodiment, one kind of colored particles 32 is sealed between the display substrate 18 and the back substrate 28. In the third embodiment, two kinds of colored particles 32 are sealed between the substrates. . In the third embodiment, two types of colored particles 32 are encapsulated between the substrates. However, three or more types of colored particles 32 having different colors and charging characteristics may be encapsulated.

  In this embodiment, the two types of colored particles 32 encapsulated between the substrates enclose white particles 32W colored white and black particles 32K colored black. However, the color to be colored is not limited to this. The colored particles 32 colored in other colors may be applied.

  In the present embodiment, the charging characteristics of the two kinds of colored particles 32 sealed between the substrates are charged with opposite polarities, the black particles 32K are positively charged, and the white particles 32W are negatively charged. The black particles 32K may be negatively charged and the white particles 32W may be positively charged.

  Here, an example of display drive control of the image display apparatus according to the third embodiment will be described. As described above, the charging characteristics of the colored particles 32 are such that the black particles 32K are positively charged and the white particles 32W are negatively charged.

  When the voltage application unit 40 applies a voltage so that the back substrate 28 side becomes negative between the transparent electrode 16 and the electrode 22 by the control of the control unit 42 (display substrate 18 side applied voltage> back substrate 28 side applied voltage), FIG. As shown in (A), the positively charged black particles 32K are moved to the back substrate 28 side, and the negatively charged white particles 32W are moved to the display substrate 18 side. Further, the large-diameter particles 36 of the charging layer 34 have their positively charged hemisphere rotated to the back substrate 28 side and negatively charged hemisphere to the display substrate 18 side. That is, the negatively charged hemispherical surface of the large-diameter particle 36 and the positively charged black particle 32K face each other, and the holding force of the black particle 32K on the back substrate 28 side is improved by the electrostatic attractive force. Further, since the negatively charged white particles 32W are repulsive by the negatively charged hemisphere of the large-diameter particles 36, the holding force of the white particles 32W on the display substrate 18 side is improved.

  Further, under the control of the control unit 42, the voltage application unit 40 applies a voltage between the transparent electrode 16 and the electrodes 22 </ b> A and 22 </ b> C so that the back substrate 28 side is positive (display substrate 18 side applied voltage <back substrate 28 side applied voltage). At the same time, when a voltage is applied between the transparent electrode 16 and the electrode 22B so that the back substrate 28 side is negative, as shown in FIG. 8B, in the region corresponding to the electrodes 22A and 22C, the positively charged black The particles 32K are moved to the display substrate 18 side, and the negatively charged white particles 32W are moved to the back substrate 28 side. Further, the large-diameter particles 36 of the charging layer 34 corresponding to the region are rotated such that the positively charged hemisphere is on the display substrate 18 side and the negatively charged hemisphere is on the back substrate 28 side.

  On the other hand, in the region corresponding to the electrode 22B, the positively charged black particles 32K are moved to the back substrate 28 side, and the negatively charged white particles 32W are moved to the display substrate 18 side. Further, the positively charged hemisphere of the large-diameter particles 36 of the charging layer 34 corresponding to the region is rotated to the back substrate 28 side, and the negatively charged hemisphere is rotated to the display substrate 18 side.

  Accordingly, in the region corresponding to the electrode 22B, the negatively charged hemispherical surface of the large-diameter particle 36 and the positively charged black particle 32K face each other, and the black particle 32K toward the back substrate 28 side by electrostatic attraction force. The holding force of the white particles 32W on the display substrate 18 side is improved by the repulsive force of the negatively charged hemisphere of the large-diameter particles 36 and the negatively charged white particles 32W. On the other hand, in the region corresponding to the electrodes 22A and 22C, the holding force of the black particles 32K on the display substrate 18 side is improved by the repulsive force of the positively charged hemisphere of the large-diameter particles 36 and the positively charged black particles 32K. At the same time, the positively charged hemispherical surface of the large-diameter particle 36 and the negatively charged white particle face each other, and the holding force of the white particle 32W on the back substrate 28 side is improved by the electrostatic attractive force.

(Fourth embodiment)
Subsequently, an image display apparatus according to a fourth embodiment of the present invention will be described. FIG. 9 is a schematic configuration diagram showing an image display apparatus according to the fourth embodiment of the present invention.

  In the second embodiment, the color of the surface on the display substrate 18 side of the colored charging layer 34 is displayed by coloring the surface on the display substrate 18 side of the charging layer 34 and retracting the colored particles 32. However, in the fourth embodiment, colored large-diameter particles 37 are used as the large-diameter particles 36 of the charging layer 34 in the second embodiment.

  That is, in the fourth embodiment, the surface of the charging layer 34 on the display substrate 18 side is transparent, and colored large-diameter particles 37 are enclosed in the charging layer 34.

  At this time, the large-diameter particle 37 has a portion colored in a color different from the color of the colored particle 32, and in this embodiment, one hemisphere is painted white and the other hemisphere is painted black. However, the present invention is not limited to this, and other colors may be applied, or the areas to be divided into two colors may be divided into different areas.

  The large-diameter particles 37 are at least partially charged from the center of gravity and charged with a negative polarity and the rest are rotated according to the electric field formed between the substrates.

  In the present embodiment, the colored particles 32 are colored black and charged positively, and the large-diameter particles 37 are described as an example in which the white side is positively charged and the black side is negatively charged. However, it is not limited to this.

  Here, an example of display drive control of the image display apparatus according to the fourth embodiment will be described.

  When the voltage application unit 40 applies a voltage between the transparent electrode 16 and the electrodes 22A and 22B so that the back substrate 28 side is negative (display substrate 18 side applied voltage> back substrate 28 side applied voltage) by the control of the control unit 42, As shown in FIG. 9A, the positively charged colored particles 32 are moved to the back substrate 28 side. Further, the large-diameter particles 37 of the charging layer 34 are rotated such that the positively charged white hemispherical surface is rotated toward the back substrate 28 and the negatively charged black hemispherical surface is rotated toward the display substrate 18. That is, the negatively charged hemispherical surface of the large-diameter particle 37 and the positively charged colored particle 32 face each other, and the holding force of the colored particle 32 on the back substrate 28 side is improved by the electrostatic attractive force. Furthermore, since the black hemispherical surface of the large-diameter particles 37 faces the display substrate 18 side, the blackness observed from the display substrate 18 side is improved.

  Further, under the control of the control unit 42, the voltage application unit 40 applies a voltage between the transparent electrode 18 and the electrode 22A so that the back substrate 28 side is negative (display substrate 18 side applied voltage)> back substrate 28 side applied voltage). At the same time, when a voltage is applied between the transparent electrode 18 and the electrode 22B so that the back substrate 28 side is positive, the positively charged colored particles 32 are on the back substrate 28 side and the electrode 22A side as shown in FIG. 9B. The surface of the charging layer 34 on the display substrate 18 side can be observed from the display substrate 18 side, and the color of the colored large-diameter particles 37 is displayed. Further, the large-diameter particles 37 of the charging layer 34 corresponding to the electrode 22A are rotated such that the positively charged white hemisphere is rotated to the back substrate 28 side and the negatively charged black hemisphere is rotated to the display substrate 18 side. In the large-diameter particles 37 of the charging layer 34 corresponding to 22B, the positively charged black hemisphere is rotated to the display substrate 18 side, and the negatively charged white hemisphere is rotated to the back substrate 28 side. That is, the negatively charged hemispherical surface of the large-diameter particle 37 and the positively charged colored particle 32 face each other, and the holding force of the colored particle 32 on the back substrate 28 side is improved by the electrostatic attractive force. Further, the state after the colored particles 32 are moved is also maintained by the repulsive force from the portion where the positive hemisphere of the large-diameter particles 37 of the charged layer 34 is rotated toward the display substrate 18 side. Further, white is displayed by the white hemisphere of the large-diameter particles in the region corresponding to the electrode 22B.

  In the fourth embodiment, the voltage is applied between the transparent electrode 16 and the electrodes 22A and 22B. However, the present invention is not limited to this, and the configuration in which the transparent electrode 16 is omitted is provided between the electrodes 22A and 22B. A voltage may be applied.

(Fifth embodiment)
Subsequently, an image display apparatus according to a fourth embodiment of the present invention will be described. FIG. 10 is a schematic configuration diagram showing an image display apparatus according to the fifth embodiment of the present invention. The fifth embodiment is a combination of the third embodiment and the fourth embodiment, and uses two kinds of colored particles 32 and large-diameter particles 37 separated into two colors.

  That is, in this embodiment, two kinds of colored particles 32 are enclosed between the substrates, the surface of the charging layer 34 on the display substrate 18 side is transparent, and the large-diameter particles 37 of the charging layer 34 are formed on one hemisphere. The other hemisphere is painted white and black.

  In the present embodiment, positively charged black particles 32K and negatively charged white particles 32W are applied to the two types of colored particles in the same manner as in the third embodiment, but the present invention is not limited to this. In the present embodiment, unlike the fourth embodiment, the large particle 37 is described as an example in which the black side is positively charged and the white side is negatively charged. However, the present invention is not limited to this.

  Here, an example of display drive control of the image display apparatus according to the fifth embodiment will be described.

  When the voltage application unit 40 applies a voltage so that the back substrate 28 side is negative (display substrate 18 side applied voltage> back substrate 28 side applied voltage) between the transparent electrode 16 and the electrode 22 under the control of the control unit 42, FIG. As shown in (A), the positively charged black particles 32K are moved to the back substrate 28 side, and the negatively charged white particles 32W are moved to the display substrate 18 side to display white. The large-diameter particles 37 of the charging layer 34 have their positively charged black hemisphere rotated to the back substrate 28 side and negatively charged white hemisphere rotated to the display substrate 18 side. That is, the negatively charged white hemispherical surface of the large-diameter particle 37 and the positively charged black particle 32K face each other, and the holding force of the black particle 32K on the back substrate 28 side is improved by the electrostatic attraction force. The Further, since the negatively charged white particles 32W are repulsive by the negatively charged hemisphere of the large-diameter particles 37, the holding force of the white particles 32W on the display substrate 18 side is improved.

  Further, since the white hemispherical surface of the large-diameter particles 37 faces the display substrate 18, the white display by the white particles 32W is assisted, and the whiteness is improved as compared with the case where white is displayed only by the colored particles 32W.

  Further, under the control of the control unit 42, the voltage application unit 40 applies a voltage between the transparent electrode 16 and the electrodes 22 </ b> A and 22 </ b> C so that the back substrate 28 side is positive (display substrate 18 side applied voltage <back substrate 28 side applied voltage). In addition, when a voltage is applied between the transparent electrode 16 and the electrode 22B so that the back substrate 28 side is negative, as shown in FIG. 10B, in the region corresponding to the electrodes 22A and 22C, the positively charged black The particles 32K are moved to the display substrate 18 side, and the negatively charged white particles 32W are moved to the back substrate 28 side. In addition, the large-diameter particles 37 of the charging layer 34 corresponding to the region are rotated such that the positively charged black hemisphere is on the display substrate 18 side and the negatively charged white hemisphere is on the back substrate 28 side.

  On the other hand, in the region corresponding to the electrode 22B, the positively charged black particles 32K are moved to the back substrate 28 side, and the negatively charged white particles 32W are moved to the display substrate 18 side. Further, the large-diameter particles 37 of the charging layer 34 corresponding to the region are rotated such that the positively charged black hemisphere is on the back substrate 28 side and the negatively charged white hemisphere is on the display substrate 18 side.

  Accordingly, in the region corresponding to the electrode 22B, the negatively charged hemispherical surface of the large-diameter particle 37 and the positively charged black particle 32K face each other, and the black particle 32K toward the back substrate 28 side by electrostatic attraction force. The holding force of the white particles 32W on the display substrate 18 side is improved by the repulsive force of the negatively charged hemispherical surface of the large-diameter particles 37 and the negatively charged white particles 32W. On the other hand, in the region corresponding to the electrodes 22A and 22C, the holding force of the black particles 32K on the display substrate 18 side is improved by the repulsive force of the positively charged hemisphere of the large-diameter particles 37 and the positively charged black particles 32K. At the same time, the positively charged hemispherical surface of the large-diameter particles 37 and the negatively charged white particles 32W face each other, and the holding force of the white particles 32W on the back substrate 28 side is improved by the electrostatic attractive force. From the display substrate 18 side, the regions corresponding to the electrodes 22A and 22C are displayed in black, and the regions corresponding to the electrodes 22B are displayed in white. In each region, the color of the large-diameter particles 37 of the charging layer 34 Therefore, white and black are assisted, so that the black and white coloring degree is improved as compared with the case where white and black are displayed only by the colored particles 32.

  In the image display apparatus according to the fifth embodiment, as shown in FIG. 11, the colored particles 32 are colored particles 52 (in FIG. 11) in a transparent capsule 50 in which a transparent intracapsule electrophoresis solution is sealed. The black particles 52K and the white particles 52W) may be enclosed. Moreover, you may make it apply the capsule 50 shown in FIG. 11 to said each embodiment and modification.

  Further, the image display device according to the fifth embodiment uses white particles 32W, black particles 32K, and large-diameter particles 37 in which one hemisphere is separated into white and the other hemisphere is divided into black. However, instead of the black particles 32K, other colored particles may be used, and the black portion of the large-diameter particles 37 may be colored in a complementary color system of the colored particles. This prevents color mixing such that white becomes the color of the color particles when displaying white.

  In each of the above embodiments, the colored particles 32 and the large-diameter particles 36 and 37 are spherical bodies. However, the present invention is not limited to this, and various shapes of rotating bodies can be applied.

  Further, although each of the above embodiments and modifications has been described individually, the image display device may be configured by combining the respective characteristic configurations.

It is a schematic block diagram which shows the image display apparatus concerning 1st Embodiment of this invention, and shows the case where all the colored particles are moving to the back substrate side. It is a schematic block diagram which shows the image display apparatus concerning 1st Embodiment of this invention, and shows the case where some colored particles are moving to the display substrate side, and the remaining colored particles are moving to the back substrate side. It is a figure which shows the case where the magnitude | size of a large diameter particle and the magnitude | size of an electrode are made into the same magnitude | size. It is a figure which shows the case where a large diameter particle is used as an electrophoretic capsule. It is a figure which shows the case where the colored dispersion liquid is used. It is a schematic block diagram which shows the image display apparatus concerning 2nd Embodiment of this invention. It is a figure which shows the case where the colored large diameter particle is used. It is a schematic block diagram which shows the image display apparatus concerning 3rd Embodiment of this invention. It is a schematic block diagram which shows the image display apparatus concerning 4th Embodiment of this invention. It is a schematic block diagram which shows the image display apparatus concerning 5th Embodiment of this invention. It is a figure which shows an example comprised by enclosing the colored particle of each color in the transparent capsule which enclosed the transparent in-capsule electrophoretic solution.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image display apparatus 12 Image display medium 14, 26 Support substrate 16 Transparent electrode 18 Display substrate 22, 22A, 22B, 22C Electrode 24, 25 Dispersion liquid 28 Back substrate 32, 52 Colored particle 32W White particle 32K Black particle 33 Reflective surface 34 Charged layer 35, 36, 37 Large diameter particle 40 Voltage application unit 42 Control unit 46 Electrophoretic particle 48 Electrophoresis capsule 50 Capsule

Claims (14)

A pair of substrates, at least one of which is translucent,
One or more colored particles that are encapsulated between the substrates and move according to an electric field formed between the substrates; and
A charging layer provided adjacent to a region where the colored particles are sealed between the substrates, and having a charging characteristic in which positive and negative polarities can be alternately switched according to an electric field formed between the substrates;
An image display medium comprising:   The image display medium according to claim 1, wherein a medium in a region in which the colored particles are moved between the substrates is a light-transmitting gas or liquid.   3. The image display medium according to claim 1, wherein the charging layer includes a charging unit in which positive and negative polarities can be alternately switched, and the charging unit is smaller than a unit pixel.   The charged layer is composed of a plurality of rotating bodies that are partially charged from the center of gravity and positively charged while the remaining portion is negatively charged and rotated in accordance with the electric field formed between the substrates. The image display medium according to any one of claims 1 to 3, wherein the image display medium is characterized.   The charged layer is composed of a plurality of electrophoretic capsules containing positively charged first particles and negatively charged second particles dispersed in a solvent having insulating properties. The image display medium according to any one of claims 1 to 3.   The image display medium according to claim 5, wherein the viscosity of the solvent having the insulating properties of the electrophoretic capsule is higher than the medium viscosity in a region where the colored particles move between the substrates.   7. The medium according to claim 1, wherein a medium in a region in which the colored particles are moved between the substrates is a liquid colored in a color different from that of the colored particles. Image display medium.   The reflective surface colored in the color different from the said colored particle is further provided between the area | region where the said charged layer and the said colored particle are enclosed, The any one of Claim 1 thru | or 6 characterized by the above-mentioned. The image display medium described.   The image display medium according to claim 1, wherein the charging layer is colored in a color different from that of the colored particles.   The image display medium according to any one of claims 1 to 6, wherein the colored particles include two or more types having different colors and charging characteristics. A pair of substrates, at least one of which is translucent,
Colored particles encapsulated between the substrates and moving in a direction crossing the inter-substrate direction in accordance with an electric field formed between the substrates; and
Provided adjacent to the region where the colored particles are enclosed between the substrates, a part off the center of gravity is positively charged, the remaining part is negatively charged, and charged with a polarity different from that of the colored particles. A charged layer comprising a plurality of rotating bodies that are colored in the same color system as the colored particles and rotated according to an electric field formed between the substrates;
An image display medium comprising: A pair of substrates, at least one of which is translucent,
Two or more kinds of colored particles having different colors and charging characteristics, encapsulated between the substrates and moving according to an electric field formed between the substrates;
Provided adjacent to the region where the colored particles are enclosed between the substrates, a part off the center of gravity is positively charged, the remaining part is negatively charged, and of the two or more types of colored particles A charged layer including a plurality of rotating bodies that are colored in the same color system as the colored particles and are rotated according to an electric field formed between the substrates;
An image display medium comprising: A pair of substrates, at least one of which is translucent,
Two or more kinds of colored particles having different colors and charging characteristics, encapsulated between the substrates and moving according to an electric field formed between the substrates;
Provided adjacent to the region where the colored particles are enclosed between the substrates, a part off the center of gravity is positively charged, the remaining part is negatively charged, and of the two or more types of colored particles A charged layer including a plurality of rotating bodies that are colored in a complementary color system of the colored particles and are rotated according to an electric field formed between the substrates;
An image display medium comprising: An image display medium according to any one of claims 1 to 13,
Voltage applying means for applying a voltage between the substrates;
Control means for controlling the voltage application means according to image information;
An image display device comprising:

Images