JP2001174854A - Display device and display method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive display device and a display method by which characters and images of electronic information can be displayed, written once and partially erased. SOLUTION: The display device is equipped with a display sheet 6 having a large number of display pixels in which the pixel state is varied by magnetic or electric effects and with a magnetic or electric recording means to write and erase characters, pictures or the like in the sheet. In this device, the display pixel consists of microcapsules 1 to 3 housing particles which can rotate in the capsule and have two surface colors. Two or more kinds of microcapsules housing particles having different combination of two surface colors are disposed on the sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a character / character
The present invention relates to an inexpensive display device capable of displaying an image and additionally recordable, in particular, a display device using magnetic particle rotation and a display method.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 3-61196 In a device for enclosing fine particles in microcapsules and displaying information by the rotation of the fine particles, a method of displaying a color image is to use a rectangular column-shaped magnetic material display pixel to correspond to the pixel. An image display device characterized in that the semi-hard magnetic material displays three colors depending on whether a portion close to the pixel is magnetized to the N pole, S magnetized, or demagnetized. Proposed. In this device, the display color that is displayed when the semi-hard magnetic material is in the demagnetized state depends on the direction of gravity and the direction of the normal direction of the display panel. In this case, there is a disadvantage that the display color changes. 2. Japanese Patent Application Laid-Open No. 10-232630 A colored color filter composed of red, green, and blue is periodically arranged in pixel units on a display layer in which microcapsules enclosing magnetic rotating particles painted in white and black are arranged in a large number on a plane. Is disclosed. In this device, since a color filter is used, there is a disadvantage that a display panel becomes expensive. In addition, unlike the case of displaying only black and white, it is necessary to rotate the magnetic particles so that the write head position and the color filter pixel position are accurately aligned, so that accurate alignment between the magnetic head and the display sheet is required. In the case of a display device of a type in which a magnetic head and a display sheet are separated from each other, in this method, it is necessary to suppress expansion and contraction due to the temperature of the magnetic sheet, and it is necessary to use a material having a small coefficient of thermal expansion such as glass for a substrate. It has disadvantages such as a heavy sheet.

[0003] 3. Japanese Patent Application Laid-Open No. H10-214048 Colored particles coated in three colors are encapsulated in a double microcapsule of an outer shell and an inner shell.
The coloring particles control the rotation by a magnetic field. A display device is disclosed in which half of the inner shell is separately colored in black and half in black, and multicolor display is performed by a combination of the rotation position of the inner shell and the rotation position of the colored particles. In the present apparatus, by doubling the microcapsules, the manufacturing process of the microcapsules becomes complicated, resulting in an expensive display sheet. In addition, since both a magnetic circuit and an electric circuit are used, the method of controlling particle rotation becomes very complicated and expensive. 4. The yield value of a dispersion liquid in which magnetic particles are dispersed is 5 dyne / c.
A magnetic display panel characterized by having a size of m ² or more is disclosed.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an inexpensive display device and a display method capable of displaying characters and images of electronic information and capable of additionally writing and partially erasing.

[0005]

SUMMARY OF THE INVENTION A first aspect of the present invention is to provide a display sheet (A) having a large number of display pixels whose state changes by magnetic or electrical action, and a character,
In a display device capable of writing and erasing a picture or the like and having at least the sheet (A) and a magnetic or electric recording means (B), the display pixels are rotatable in a capsule and have a surface color of 2 or more. That two or more kinds of microcapsules containing particles having different colors of surface colors are arranged on the sheet (A), the microcapsules being composed of microcapsules containing particles of a color. The display device is characterized in that: The second aspect of the present invention is
In the first display device, the magnetic or electric recording means (B) is not integrated with the display sheet (A). A third aspect of the present invention is the first aspect, wherein two or more types of microcapsules containing particles having different combinations of the two surface colors are randomly arranged on the sheet (A). To 2 display devices.

A fourth aspect of the present invention is that the rotatable particles include:
The first to third display devices are characterized in that a combination of two surface colors is held in a microcapsule by a liquid or a gas having a different viscosity for each different particle. A fifth aspect of the present invention is that the rotatable particle is a permanent magnet in which the particle itself is magnetized in one direction or a particle in which the permanent magnet is dispersed or contained. In the display device. A sixth aspect of the present invention is the display device according to any one of the first to fifth aspects, wherein the magnitude of the remanent magnetization of the rotatable particles is different for each particle having a different combination of two surface colors.

[0007] A seventh aspect of the present invention is that a threshold value of an electric or magnetic force for rotating particles in two or more kinds of microcapsules is different for each particle having a different combination of two surface colors. In the above-mentioned first to sixth display devices. According to an eighth aspect of the present invention, a semi-hard magnetic material capable of being partially magnetized and demagnetized is provided on the side of the sheet (A) opposite to the sheet surface having a large number of display pixels, and the partially magnetized and demagnetized material is provided. The first to seventh display devices are characterized in that the magnitude of the remanent magnetization of the semi-hard magnetic material can be set to an arbitrary level depending on the magnitude of the magnetic field applied from the outside. According to a ninth aspect of the present invention, a specific particle having a surface color having a specific two-color combination is provided with a threshold of a particle having a threshold larger than a threshold of an electric or magnetic force of the particle and equal to or larger than a threshold of the specific particle. By applying a smaller electric or magnetic force to rotate all the particles having a threshold value equal to or less than the threshold value of the specific particle including the specific particle, the electric or magnetic force of the specific particle is rotated. By applying an opposing electrical or magnetic force that is less than a force threshold and greater than a threshold of a particle having a threshold less than the threshold of the particular particle, all of the particles having a threshold less than the threshold of the particular particle are applied. The display method is characterized in that, by rotating the particles again, only the specific particles having the combination of the specific two colors are rotated. The tenth aspect of the present invention is that the particles having a combination of two surface colors are constituted by two kinds of two-color combination particles, one kind of particles is a combination of white and black, and the other kind is a combination of white and black. A ninth display method according to the ninth display method, wherein the ninth display method includes a combination of colors other than black. An eleventh aspect of the present invention is that particles having a combination of two surface colors are constituted by three types of combination particles of two colors, one type is a combination of white and red, and the second type is a combination of white and green. The ninth display method is characterized in that the third type is a combination of white and blue. A twelfth aspect of the present invention is that particles having a combination of two surface colors are composed of four types of two-color combination particles, one type combining white and red, and the second type combining white and green. The ninth display method is characterized in that the third type is a combination of white and blue, and the fourth type is a combination of white and black.

In the display device of the present invention, even if a display sheet is coated with microcapsules at random, the color of the microcapsules on the magnetic head can be changed to a desired color by a method of generating a magnetic field of the magnetic head disposed below the display sheet. Since it is possible to display colors, there is no need to align the magnetic head and the display sheet, and a low-cost and light material is used as the base material of the display sheet, although the coefficient of thermal expansion of a film or plastic sheet is large. A magnetic particle rotating display device of a color display to be used can be provided. As a result, the display sheet and the display head can be separated, for example, display on a plurality of sheets can be performed using one display head, and a display system that is less expensive than a device that requires a display head for each display sheet can be provided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a display device and a display method according to the present invention will be described below with reference to the drawings.

Embodiment 1 A display device shown in FIG. 1 has a display sheet 6 comprising three types of microcapsules 1, 2, and 3 and a sheet 5 containing or coated with a semi-hard magnetic material 4, and a magnetic head. It is composed of an array 7. Each microcapsule has a configuration in which permanent magnet particles are contained in a transparent cell. The permanent magnet particles are magnetized in advance to have an N pole and an S pole. In addition, the surface of the permanent magnet particles is painted in two colors, and in this embodiment, the microcapsule 1 is red on the N pole side and white on the S pole side, the microcapsule 2 is green on the N pole side and green on the S pole side. The microcapsules 3 are painted blue on the N pole side and white on the S pole side. The permanent magnet particles are held in the cell by gas or liquid, and are not physically bonded to the transparent cell so that they can be rotated by magnetic force. The above three types of microcapsules 1, 2, 3
Is applied evenly on the sheet 5 and bonded so that only specific microcapsules are not partially biased as shown in FIG. For example, as shown in FIG. 1, three types of microcapsules 1, 2, and 3 are made into one block unit,
It is preferable to apply and adhere to the sheet for each block. In the present invention, the display sheet refers to a microcapsule containing a permanent magnet, a sheet containing or applying a semi-hard magnetic material, or the like.

The permanent magnet particles in the three types of microcapsules 1, 2, and 3 are held in the microcapsules so as to rotate when the intensity of magnetization of the semi-hard magnetic material 4 exceeds a certain threshold. In this embodiment, the permanent magnet particles in the microcapsule 1 are in the air, the permanent magnet particles in the microcapsule 2 are in the dispersion liquid having a yield value of about 0.2 dyne / cm ^2, and the permanent magnet particles in the microcapsule 3 are in the dispersion liquid. The magnet particles are held in a dispersion liquid having a yield value of about ² dyne / cm ² . The threshold of the magnetic force at which the permanent magnet particles in each microcapsule rotates is 5 Gauss for microcapsule 1 and 15 Gau for microcapsule 2.
ss, the microcapsule 3 is set to 30 Gauss. Using a two-dimensional magnetic head array 7 corresponding to the display pixel pitch from below the display sheet 6 whose surface is covered with the microcapsules 1, 2, and 3, the semi-hard magnetic material 4
Magnetization. In the present embodiment, three microcapsules 1, 2 and 3 are used as one block unit, but the number of one block unit of the microcapsules is not limited to three and may be arbitrary. May be the number of Further, the permanent magnet particles may be particles in which minute permanent magnets are dispersed or incorporated.

Embodiment 2 An embodiment of a method for displaying a specific color for each magnetic head corresponding to the pixel pitch will be described. The magnetic field applied to the microcapsules from the semi-hard magnetic material of the display device of FIG.
A downward magnetic field is applied to the magnetic head 7 so as to be equal to or more than Gauss, so that the white portions of all the pixels are directed to the surface to be in an initial state.

(1) Red display method An upward magnetic field is applied to the magnetic head 7-1 in FIG. 2 so that the intensity of the magnetic force applied to the microcapsules from the semi-hard magnetic material 4 becomes 5 Gauss or more and less than 15 Gauss. The magnetization of the semi-hard magnetic material 4 is reversed so as to be as follows. As a result, of the three types of microcapsules, only the microcapsules 1 having a red color are inverted, and the pixels on the magnetic head 7-1 are displayed in red. (2) Green display method An upward magnetic field is applied to the magnetic head 7-2 in FIG. 2 so that the magnetic force applied from the semi-hard magnetic material 4 to the microcapsule is not less than 15 Gauss and less than 30 Gauss. The magnetization of the semi-hard magnetic material 4 is reversed. As a result, of the three types of microcapsules, the microcapsules 1 and 2 having red and green colors are inverted. Next, the magnetization of the semi-hard magnetic material 4 is reversed again using the magnetic head 7-2 in FIG. 3 so that the magnetic force applied to the microcapsules becomes 5 Gauss or more and less than 15 Gauss.
As a result, only the microcapsule 1 is inverted again, and finally, the pixels on the magnetic head 7-2 become the microcapsule 2
Only is inverted and green is displayed. (3) Blue display method An upward magnetic field is applied to the magnetic head 7-3 in FIG. 2, and the semi-hard magnetic material is applied so that the magnetic force applied from the semi-hard magnetic material 4 to the microcapsule becomes 30 Gauss or more. The magnetization of the material 4 is reversed. Thereby, all three types of microcapsules are inverted. Next, the magnetic head 7- in FIG.
3, the magnetization of the semi-hard magnetic material 4 is reversed again so that the intensity of the magnetic force applied to the microcapsules becomes 15 Gauss or more and less than 30 Gauss. As a result, the microcapsules 1 and 2 are inverted again, and finally the pixels on the magnetic head 7-3 are in a state where only the microcapsules 3 are inverted, and blue is displayed.

Embodiment 3 In Embodiments 1 and 2, full-color display can be achieved by using three types of microcapsules containing permanent magnet particles which are separately coated in red / white, green / white, and blue / white. Although an example of a possible display device has been described, when full-color display is not required as in an electronic blackboard or the like, two types of microcapsules are used in the display devices of Embodiments 1 and 2; Created a display device consisting of a combination of black and the other is a combination of colors other than white and black, and for example, a display device in which electronic pixel display is black and additional writing is performed in a color other than black was realized. .

Embodiment 4 One kind of microcapsule is a combination of white and red, the second kind is a combination of white and green, the third kind is a combination of white and blue, and the fourth kind is a combination of white and black. By using the four types of microcapsules described above and giving each microcapsule a different inversion threshold, a full-color display device having a large contrast was obtained.

As a method of controlling the threshold value for inverting the permanent magnet particles in the microcapsule, in addition to the method of holding the cell with a gas or liquid having a different viscosity in the cell described in the above embodiment, , And a combination of the above two methods. In the above embodiment, the display method using the rotating magnetic particles has been described. However, in the display using the electric particle rotation in which the spherical dielectric is encapsulated in the microcapsule and the particles are rotated according to the direction of the electric field to perform the display. Also, the color display shown in the present invention can be performed.

[0017]

[Effect] 1. Claims 1 to 8 An inexpensive display device capable of displaying electronic information and an image, being recordable, and capable of separating a magnetic head and a display sheet, particularly a display device using magnetic particle rotation is provided. 2. According to the ninth aspect of the present invention, there is provided a display method capable of rotating only a combination particle of a specific color. 3. Claim 10 A display method capable of changing the colors of the display and the additional writing has been provided. 4. [Claim 11] A display method for displaying a display color in full color is provided. 5. A twelfth aspect of the present invention provides a full-color display method in which display colors are performed in full color and the contrast is high.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic cross section of a display device according to a first embodiment.

FIG. 2 is a schematic diagram illustrating a method of displaying a specific color for each magnetic head corresponding to a pixel pitch according to a second embodiment.

FIG. 3 is a schematic diagram illustrating a method for displaying a specific color for each magnetic head corresponding to a pixel pitch according to a second embodiment.

[Explanation of symbols]

 Reference Signs List 1 1 type of microcapsules 2 1 type of 3 types of microcapsules 3 1 type of 3 types of microcapsules 4 Semi-hard magnetic material 5 Sheet containing or coated with semi-hard magnetic material 6 Display sheet 7 Magnetic head array

Claims (12)

[Claims] 1. A display sheet (A) having a large number of display pixels, the state of which changes by magnetic or electrical action, and characters and pictures can be written and erased on the sheet (A). (A) and at least a magnetic or electric recording means (B), wherein the display pixel is constituted by a microcapsule containing particles capable of rotating inside the capsule and having two surface colors, The sheet (A) is a sheet in which the microcapsules contain two or more kinds of particles having different combinations of surface colors.
A display device, which is disposed on the display. 2. The magnetic or electric recording means (B)
The display device according to claim 1, wherein the display device is not integrated with the display sheet (A). 3. A sheet according to claim 1, wherein two or more kinds of microcapsules containing particles having different combinations of the two surface colors are randomly arranged on the sheet (A). The display device according to any one of the above. 4. The microcapsule according to claim 1, wherein the rotatable particles are held in a microcapsule by a liquid or a gas having a different viscosity for each particle having a combination of two surface colors. The display device according to any one of the above. 5. The rotatable particle is a permanent magnet in which the particle itself is magnetized in one direction or a particle in which the permanent magnet is dispersed or contained.
The display device according to any one of claims 1 to 4. 6. The magnitude of the remanent magnetization of a rotatable particle is:
The display device according to any one of claims 1 to 5, wherein a combination of two surface colors is different for different particles. 7. An electrical or magnetic force threshold for rotating particles in two or more microcapsules,
The display device according to any one of claims 1 to 6, wherein a combination of two surface colors is different for different particles. 8. A semi-hard magnetic material capable of being partially magnetized and demagnetized is provided on a side of the sheet (A) opposite to a sheet surface having a large number of display pixels, and said partially magnetized and demagnetizable material is provided. 8. The display device according to claim 1, wherein the magnitude of the remanent magnetization of the semi-hard magnetic material can be set to an arbitrary level depending on the magnitude of a magnetic field applied from the outside. 9. The method according to claim 1, wherein the surface color of the specific particle having a specific two-color combination is larger than the threshold of the particle having an electric or magnetic force larger than the threshold of the electric or magnetic force and being equal to or larger than the threshold of the specific particle. After applying a small electric or magnetic force to rotate all particles having a threshold equal to or less than the threshold of the specific particle, including the specific particle,
By applying an opposing electrical or magnetic force that is less than a threshold of an electrical or magnetic force of the specific particle and greater than a threshold of a particle having a threshold less than the threshold of the specific particle, A display method characterized by rotating all the particles having a threshold value less than the threshold value of particles again to rotate only the specific particles having the surface color having a specific combination of two colors. 10. Particles having a combination of two colors of surface color are composed of two kinds of combination particles of two colors, one kind of particles is a combination of white and black, and the other kind is other than white and black. 10. The display method according to claim 9, wherein the display method comprises a combination of the following colors. 11. Particles having a combination of two colors of surface color are composed of three kinds of combination particles of two colors, one kind is a combination of white and red, the second kind is a combination of white and green, 10. The display method according to claim 9, wherein the type is a combination of white and blue. 12. A particle having a combination of two surface colors is composed of four types of two-color combination particles, one type being a combination of white and red, the second type being a combination of white and green, and 10. The display method according to claim 9, wherein the type is a combination of white and blue, and the fourth type is a combination of white and black.