JP2005284234A - Electrophoretic display element by vertical migration with barrier rib, electrophoretic display method and electrophoretic display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophoretic display apparatus which uses charged fine particles and charged magnetic fine particles by irradiation with radiation, which suppresses cross talk and which is capable of simple matrix driving. <P>SOLUTION: The electrophoretic display element and the electrophoretic display apparatus are equipped with a first substrate 1, a first driving electrode 6 laid on the first substrate, a second substrate 17 disposed to oppose the first substrate 1, a second driving electrode 12 laid on the second substrate, and a plurality of migration fine particles 8, 9 and 20 dispersed in a transparent insulating liquid 10 filling the space between the first substrate 1 and the second substrate 17. The electrophoretic display apparatus realizes high-definition image display by assembling the electrophoretic display elements each of which has electrodes to apply an AC electric field or an AC magnetic field or to superpose both to agitate the transparent insulating liquid 10 and which vertically moves the migration fine particles. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrophoretic display element that performs display by stirring and vertically moving charged fine particles or charged magnetic fine particles charged in an electron trap or hole trap by an irradiation with an AC electric field and an AC magnetic field. , Electrophoretic display method and electrophoretic display device.

The display device started from a cathode ray tube with a history of 100 years. Fluorescent display tubes, electroluminescence display devices, light emitter diode display devices, liquid crystal display devices, plasma display panel display devices, etc. are commercially available. Yes. However, all of these commercially available display devices do not endure gaze for a long time because they use luminescent color and transmitted light and see the color of the substance itself with a display device (transmission type) for viewing.
With the recent progress in IT, development of a next-generation display device (reflection type) for reading that has display characteristics like printed materials, is easy on the eyes, and can withstand long-time gaze is active. In particular, the progress of electronic technology in newspapers is remarkable, and distribution via satellite and broadband communication lines is expected to contribute to conservation of forest resources and the global environment through major reforms such as printing, transportation and delivery, and reduction of paper consumption. ing.

In order to satisfy such demands, next generation display devices have many demands such as large size, low price, high definition, energy saving, high speed response and full color. For this reason, many systems such as a particle system, a liquid crystal system, and a rewritable marking system have been developed.
The most frequently used liquid crystal display devices have excellent display characteristics such as high speed, colorization, and moving images. However, in addition to the problems related to the display quality of the transmission type, the resolution is generally about 120 dpi at the maximum. It is considerably low even when compared to PRINT OUT (usually 300 dpi).
For low price, large size, and high definition, the display method by electrophoresis of charged fine particles is considered to be the optimum technology for next generation display devices for ideal reading. For this reason, electrophoretic display devices have been developed, such as a method for moving particles in a microcapsule in the thickness direction and a method for rotating electrophoretic fine particles, but more than 300 dpi, such as electronic display of books and newspaper display by satellite distribution. Therefore, an electrophoretic display device in which spherical charged fine particles of several μm are dispersed in a transparent insulating liquid is insufficient.

  The idea of using charged fine particles for electrophoretic movement and displaying or storing them has been proposed for a long time (Ota: Patent Publication No. 50-15115), but the shape of charged fine particles and the charged potential (ζ potential) are small and unstable. Furthermore, there were many technical problems such as secondary aggregation and precipitation of migrating particles, erasure of previous history display images, and response speed, which could not be realized.

  As a full-fledged electrophoretic display method, there is a proposal of a horizontal movement type electrophoretic display method and apparatus for moving charged fine particles horizontally (Gouda: Japanese Patent Laid-Open Nos. 49-5598 and 11-202804). . This is a display device using a electrophoresis of electrophoretic particles dispersed in a transparent insulating liquid and provided with a partition wall that suppresses the occurrence of crosstalk and capable of a simple matrix driving method. However, since a barrier is provided for each pixel, a large display device has a complicated configuration, and solutions such as secondary aggregation, precipitation, and erasure of previous display images have not been made.

Problems to be solved by the invention

However, the present inventors have found that the electrophoretic display device has serious drawbacks that cannot be put into practical use. That is, when the image display is repeated, the display image adsorbed on the transparent insulating layer (display surface) covering the surface of the drive electrode adheres electrostatically strongly, and even if a DC electric field having a reverse polarity is applied. In the case of display writing again without being completely peeled off, there is a problem as an afterimage. Even when charged fine particles having a specific gravity smaller than that of the transparent insulating liquid are used, the electrophoretic particles are enlarged due to secondary aggregation, and the electrophoretic particles are precipitated in the long term, causing deterioration in image quality. The non-uniform distribution of the electrophoretic fine particles dispersed in the transparent insulating liquid due to long-term use affects the image quality of the display image and reduces the contrast. In general, the electrophoretic display method does not have a threshold because the electrophoretic fine particles do not have a threshold value, and a good contrast cannot be obtained.
In summary, the production of stable and sustained charged fine particles, separation of positive and negative charged fine particles, removal of secondary aggregation of electrophoretic fine particles and prevention of precipitation, erasure of previous history display images, migration in transparent insulating liquids There is a need for means that can simultaneously solve the uniform concentration distribution of fine particles, the improvement of image contrast, the elimination of crosstalk, and the like.
The largest defect is the persistence of the charged fine particles. Electrophoretic fine particles used in electrophoretic display devices use coloring materials such as dyes and ions, and bring in new charges. Therefore, they act as instability factors during electrophoresis due to an electric field, and have problems with stability. . In particular, when silicon oil or petroleum-based transparent insulating liquid is used, reduction of the charged charge cannot be improved by frictional charging or the like.

Means for solving the problem

The polymer fine particle material colored with black and color with electron traps is synthesized into true spherical fine particles, and this is synthesized with negatively charged fine particles by irradiation and polymer fine particle material with hole traps into true spherical fine particles. The electret charged fine particles such as white positively charged fine particles were developed by irradiation of this. An electrophoretic display element, an electrophoretic display method, and an electrophoretic display device having a novel configuration using the above were devised.
That is, the first substrate, the first transparent electrode, the transparent insulating layer, the first transparent driving electrode, and the transparent insulating layer (display surface) disposed on the first substrate are disposed to face the first substrate. The second substrate, the second electrode, the insulating layer, the second drive electrode, and the insulating layer (non-display surface) disposed on the second substrate, and the space between the first substrate and the second substrate are filled. AC electric field type electrophoretic display element and electrophoretic display method in which two types of positive and negative electrophoretic fine particles of transparent insulating liquid, black negatively charged particles dispersed in transparent insulating liquid, and white positively charged fine particles are enclosed And an electrophoretic display device.

In the display method, first, an AC electric field is applied between the first transparent electrode and the second electrode, the transparent insulating liquid is stirred, and simultaneously, a display DC electric field is applied between the first transparent drive electrode and the second drive electrode. The positive and negative electrophoretic particles are switched and vertically moved to move the black negative charged fine particles on the display surface of the positive electric field part and the white positively charged fine particles move to the non-display surface of the negative electric field part. Thereafter, an AC electric field is applied between the first transparent electrode and the second electrode to stir the insulating liquid to erase the previous display image, and a third process to make the display image white. I do. In order to perform white display, the direct current electric field for display is reversed in the first process, and the white positive charged fine particles are moved vertically to the display surface and the black charged fine particles are moved vertically to the non-display surface. If the black charged fine particles are charged fine particles of magenta, yellow, cyan, etc., a color display electrophoretic display element can be realized. This driving method is called an AC electric field method.
In this method, positive and negative electrophoretic fine particles are separated by stirring charged charged fine particles with an electric field, and fine black, white and color images are displayed on the display surface according to the polarity of the DC signal for display.

Developed electret black and color-loaded electromagnetic fine particles produced by adding magnetic fine particles to black and colored polymer fine particle materials with electron traps to synthesize spherical particles and irradiating them. . An electrophoretic display element, an electrophoretic display method, and an electrophoretic display device having a novel configuration using this and the white positively charged fine particles have been devised.
That is, a first substrate, a first transparent electrode (thin film magnetic generating coil electrode) disposed on the first substrate, a transparent insulating layer, a first transparent driving electrode, a transparent insulating layer (display surface), and the first substrate A second substrate disposed opposite to the first substrate, a second electrode (thin film magnetic coil electrode) disposed on the second substrate, an insulating layer, a second drive electrode, and an insulating layer (non-display surface) ), Positive and negative charges of the transparent insulating liquid filled between the first substrate and the second substrate, the black loaded electromagnetic fine particles dispersed in the transparent insulating liquid, and the white positive charged fine particles. The present invention proposes an electrophoretic display element, an electrophoretic display method, and an electrophoretic display device in which two types of electrophoretic fine particles are encapsulated.

In the display method, first, an alternating current is passed between the first transparent electrode and the second electrode to generate an alternating magnetic field, the transparent insulating liquid is stirred, and simultaneously a direct current electric field for display is generated between the first transparent driving electrode and the second driving electrode. Apply. The positive and negative electrophoretic fine particles are switched and vertically moved, and the black charged magnetic fine particles move on the display surface of the positive electric field portion, and the white positive charged fine particles move on the non-display surface of the negative electric field portion, and the first process for generating contrast, image display Then, a second process of passing an alternating electric field between the first transparent electrode and the second electrode to generate an alternating magnetic field to stir the transparent insulating liquid and applying a peeling direct current to erase the previous history display image; Further, image display is performed by a third process of displaying the entire white color of the display screen. In order to perform white display, the direct current electric field for display is reversed in the first process, and the white positively charged fine particles are moved vertically to the display surface and the black charged magnetic fine particles are moved vertically to the non-display surface. If the black charged magnetic fine particles are magenta, yellow and cyan charged magnetic fine particles, a color display electrophoretic display element can be realized. This driving method is called a magnetic induction method.
By stirring magnetically charged magnetic fine particles with a magnetic field, positive and negative electrophoretic fine particles are separated, and a desired black / white fine image is displayed on the display surface by a display DC signal.

An electrophoretic display element, an electrophoretic display method, and an electrophoretic display device having a novel configuration in which the black charged magnetic fine particles and the white positively charged fine particles are used and an alternating electric field and an alternating magnetic field are superimposed on the stirring of the moving fine particles have been devised.
That is, a first substrate, a first transparent electrode disposed on the first substrate, a transparent insulating layer, a second transparent electrode (coiled electrode for generating a thin film magnetic field), a transparent insulating layer, a first transparent driving electrode, and an insulating layer (Display surface), a second substrate disposed opposite to the first substrate, a second electrode disposed on the second substrate, an insulating layer, a third electrode (coiled electrode for generating a thin film magnetic field), Insulating layer, second drive electrode, insulating layer (non-display surface), transparent insulating liquid filled between first substrate and second substrate, and black load electromagnetic wave dispersed in transparent insulating liquid We propose an alternating current electric field / magnetic induction type electrophoretic display element that encloses two types of positive and negative electrophoretic fine particles, ie, positive and white fine particles.

  In the display method, first, an AC electric field is applied to the first transparent electrode and the second electrode to stir the transparent insulating liquid by the electric field, and an AC current is simultaneously applied between the second transparent electrode and the third electrode to generate an AC magnetic field. Then, the AC electric field and the AC magnetic field are superimposed to stir the black loaded electromagnetic fine particles and the white positively charged fine particles in the transparent insulating liquid. At the same time, a display DC electric field is applied between the first transparent drive electrode and the second drive electrode. First positive and negative electrophoretic fine particles are interchanged and vertically moved, black loaded electromagnetic fine particles move on the display surface of the positive electric field portion, and white positive charged fine particles move on the non-display surface of the negative electric field portion, and a first process, image After the display, an AC electric field is generated between the first transparent electrode and the second electrode, an AC magnetic field is generated on the second transparent electrode and the third electrode, the transparent insulating liquid is stirred, and a peeling DC electric field is applied at the same time. Next, the image is displayed by the second process of erasing the image, and then by the third process of displaying the entire white color of the display screen. In order to perform white display, it is only necessary to reverse the surface direct current electric field to vertically move white positively charged fine particles to the display surface and black load electromagnetic fine particles to the non-display surface. If the black load electromagnetic fine particles are magenta, yellow, and cyan load electromagnetic fine particles, a color display electrophoretic display element can be realized. This driving method is called an AC electric field / magnetic induction method.

  When AC electric field and AC magnetic field are applied to positively charged white positively charged fine particles and negatively charged and magnetically charged black loaded electromagnetic fine particles, it is easy to separate positive and negative migrating fine particles by stirring independently. When a DC signal for display is applied, it moves vertically in the direction of the display surface or non-display surface depending on the polarity, and both migrating microparticles are replaced, enabling high-definition image display with high-speed response.

  When the electrophoretic display elements based on the AC electric field method described above are assembled and integrated and driven by a simple matrix circuit, an active matrix circuit, or the like, an electrophoretic display device using an AC electric field method can be obtained. In addition, if an electrophoretic display element using magenta, yellow, cyan, etc., color negatively charged fine particles instead of black loaded electromagnetic fine particles and the white positively charged fine particles is used, a color electrophoretic display device using an AC electric field method Is realized.

  When the electrophoretic display elements by the magnetic induction method described above are assembled and integrated and driven by a simple matrix circuit, an active matrix circuit, or the like, an electrophoretic display device by a magnetic induction method can be obtained. If an electrophoretic display element using magenta, yellow, cyan, or other color-loaded electromagnetic fine particles and the white positively charged fine particles is used instead of the black-loaded electromagnetic fine particles, color electrophoresis using a magnetic induction method is performed. A display device is realized.

  When the electrophoretic display elements by the AC electric field / magnetic induction system described above are assembled and integrated and driven by a simple matrix circuit, an active matrix circuit, or the like, an electrophoretic display device by an AC electric field / magnetic induction system can be obtained. In addition, instead of black charged magnetic fine particles, color-loaded electromagnetic fine particles such as magenta, yellow, and cyan, and an electrophoretic display element using the white positively charged fine particles, color electric current by an AC electric field / magnetic induction method is used. An electrophoretic display device is realized.

  In the electrophoretic display element described above, the second substrate, the second electrode disposed on the second substrate, the insulating layer, the third electrode, the insulating layer, the second drive electrode, the insulating layer (non-display surface), and the like are transparent. When a light-sensitive material is used so that transmitted light can be irradiated from below, a transmission type electrophoretic display device can be obtained.

  The white positively charged fine particles have a particle size of 1 to 10 μm by suspension polymerization of Si fine oxide particles having a particle size of 0.1 μm as a hole trap and a white pigment such as titanium oxide or zinc oxide as a hole trap. These particles are irradiated with 5 to 10 kGy gamma rays to form white positively charged fine particles having a ζ potential of 20 to 100 mV. Since the particle size is true spherical fine particles and the particle size distribution is narrow, positively charged fine particles that are dispersed in a transparent insulating liquid and regularly move at a high speed when a direct current electric field for display is applied, and respond in a short time.

The black loaded electromagnetic fine particles are obtained by adding a fluorine resin as an electron trap material to a black colored polymer fine particle material, and further, magnetic fine particles of 0.1 μm or less such as Pt—Co, MnBi ferrite, YIG or the like, SmCo ₅ , FePt. Then, nanomagnetic fine particles such as CoPt are added to obtain spherical fine particles having a particle diameter of 1 to 10 μm by suspension polymerization. This is irradiated with an electron beam of 50 to 100 kGy to form black loaded electromagnetic fine particles having a ζ potential of −20 to −100 mV. Since the particle size is a true spherical fine particle and the particle size distribution is narrow, when a direct current electric field for display is applied and dispersed in a transparent insulating liquid, it regularly moves at high speed, and electrophoretic fine particles responding in a short time are obtained. In addition, when the same operation is repeated by using a polymer fine particle material colored in magenta, yellow, cyan, etc. as a polymer fine particle material, and repeating the same operation, colored electromagnetic particles can be produced.

  The white positively charged magnetic fine particles are obtained by adding, as a hole trap, a Si-based oxide ultrafine particle having a particle size of 0.1 μm or less, a white pigment such as titanium oxide or zinc oxide, and transparent magnetic fine particles YIG as a hole trap. The spherical superfine particles having a particle diameter of 1 to 10 μm are obtained by suspension polymerization. This is irradiated with 5 to 10 kGy of gamma rays to form white positively charged magnetic fine particles having a ζ potential of +20 to +100 mV. Since the particle size distribution is a true spherical ultrafine particle and the particle size distribution is narrow, when a direct current electric field for display is applied, a moving microparticle that regularly moves at high speed and responds in a short time is obtained.

  Transparent glass or polymer film can be used for the first substrate and the second substrate material.

The distance between the first substrate and the second substrate is preferably about 20 times or less of the particle size of the electrophoretic fine particles in consideration of the image quality of the display image, the contrast and the driving voltage, or 150 μm or less in consideration of the display DC electric field.
The electrophoretic display element may be a combination of black loaded electromagnetic fine particles and white positive charged fine particles, black positive charged fine particles, white negative charged fine particles, black positive charged magnetic fine particles, and white negative charged fine particles. In addition, a combination of white positively charged fine particles and magenta, yellow, cyan, etc., loaded electromagnetic fine particles, and a combination of white positively charged magnetic fine particles and magenta, yellow, cyan, etc. negatively charged fine particles can be used. . The charged magnetic fine particles have a particle size that is 2 to 5 times larger than that of the charged fine particles, and the separability is good in an alternating electric field and an alternating magnetic field in a transparent insulating liquid.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to the present invention will be described in detail below with reference to the drawings, but the dimensions and shapes of elements in the drawings are neither actual dimensions nor proportional to actual dimensions, which facilitates understanding. Therefore, it is exaggerated as appropriate.

FIG. 1 shows a basic configuration diagram of an electrophoretic display element according to the present invention. For the sake of convenience, FIG. I. Is an AC electric field system composed of black negatively charged fine particles 8 and white positively charged fine particles 9. A first substrate 1 (nesa glass), a first transparent electrode 2, a transparent insulating layer 3, a first transparent driving electrode 6, a transparent insulating layer (display surface) 7 disposed on the first substrate 1, and the first A second substrate 17 disposed opposite to the first substrate 1; a second electrode 16, an insulating layer 13, a second drive electrode 12, and an insulating layer (non-display surface) 11 disposed on the second substrate 17; The positive and negative of the transparent insulating liquid 10 filled between the first substrate 1 and the second substrate 17, the black electrophoretic particles 8 dispersed in the transparent insulating liquid 10, and the white positively charged fine particles 9. It is an electrophoretic display element that encloses two types of electrophoretic fine particles and moves vertically.
An AC power supply 22 is connected between the first transparent electrode 2 and the second electrode 16, the migrating fine particles are stirred by an AC magnetic field, and a display DC power supply 21 is connected between the first transparent drive electrode 6 and the second drive electrode 12. Then, the electrophoretic fine particles 8 and 9 are vertically moved to move the black negative charged fine particles 8 to the transparent insulating layer (display surface) 7 and the white positively charged fine particles 9 to the insulating layer (non-display surface) 11 to display an image.

II is a magnetic induction system composed of black loaded electromagnetic fine particles 20 and white positively charged fine particles 9. The transparent electrode on the surface of the first substrate 1 (Nesa glass) is patterned to form a thin-film coiled second transparent electrode 4 for generating a magnetic field. The transparent insulating layer 5, the first transparent drive electrode 6, and the transparent insulating layer (display surface) 7, a second substrate 17 disposed opposite to the first substrate 1, a thin film coiled third electrode 14 for generating a magnetic field disposed on the second substrate 17, an insulating layer 13, a second drive electrode 12, and Insulating layer (non-display surface) 11, transparent insulating liquid 10 filled between the first substrate and the second substrate, black load electromagnetic fine particles 20 dispersed in the transparent insulating liquid, and white positive charge This is an electrophoretic display element that encloses two types of electrophoretic particles, positive and negative, with the fine particles 9 and moves vertically.
A magnetic field generating AC power source 23 is connected between the second transparent electrode 4 and the third electrode 14, the black charged magnetic fine particles are stirred by the AC magnetic field, and the display DC is connected between the first transparent drive electrode 6 and the second drive electrode 12. The power source 21 is connected to move the electrophoretic fine particles 20 and 9 vertically, and the black loaded electromagnetic fine particles 20 are applied to the transparent insulating layer (display surface) 7 and the white positively charged fine particles 9 are applied to the insulating layer (non-display surface) 11. Move to display image.

III is an AC electric field / magnetic induction system composed of black loaded electromagnetic fine particles 20 and white positively charged fine particles 9 and stirring the migrating particles by superimposing an alternating electric field and an alternating magnetic field. The first substrate 1 and the second transparent electrode (coiled electrode for generating a thin film magnetic field) by patterning the first transparent electrode 2, the transparent insulating layer 3, and the transparent electrode disposed on the first substrate to form a magnetic field generating thin film coil ) 4, the transparent insulating layer 5, the first transparent drive electrode 6, the transparent insulating layer (display surface) 7, the second substrate 17 disposed opposite to the first substrate 1, and the second substrate 17 The second electrode 16, the insulating layer 15, the third electrode (coiled electrode for thin film magnetic field generation) 14, the insulating layer 13, the second drive electrode 12, and the insulating layer (non-display surface) 11 disposed on the top is there. A transparent insulating liquid 10 filled between the first substrate 1 and the second substrate 17, black load electromagnetic fine particles 20 dispersed in the transparent insulating liquid 10, white positively charged fine particles 9, and two types of positive and negative It is an electrophoretic display element that encloses migrating particles and moves vertically.
The AC power source 22 is connected between the first transparent electrode 2 and the second electrode 16, and the AC power source 23 for magnetic field generation is connected between the second transparent electrode 4 and the third electrode 14. 20 and 9 are agitated, a display DC power source 21 is connected between the first transparent drive electrode 6 and the second drive electrode 12, the electrophoretic particles 20 and 9 are moved vertically, and the black charged magnetic fine particles 20 are formed into an insulating layer. On the (display surface) 7, the white positively charged fine particles 9 are moved to the insulating layer (non-display surface) 11 to display an image.

  FIG. 2 is a time chart showing details of the driving method of each method. FIG. A shows an AC electric field system. The first step is divided into three stages, the first half, the middle, and the second half. First, an alternating electric field is applied between the first substrate and the second substrate, the transparent insulating liquid is stirred by the electric field, and in the previous period, a peeling direct current electric field is superimposed, the previous history display image is erased, and both electrophoretic particles are separated. In this case, a display direct current electric field is applied, black load electromagnetic fine particles are vertically moved to the display surface, white positively charged fine particles are vertically moved to the non-display surface, and an alternating electric field is excluded in the later stage to perform image display. In the second step, an AC electric field and a peeling DC electric field are applied to erase the previous history display image. In the third step, a negative DC electric field is applied to whiten the entire display surface, and the operation ends.

  FIG. B shows a magnetic induction system. The first step is divided into three stages, the first half, the middle, and the second half. First, an alternating current is applied between the first substrate and the second substrate to generate a magnetic field, and the transparent insulating liquid is stirred by the magnetism and magnetic field of the black loaded electromagnetic fine particles 20. Erasing previous history display image and separating positive / negative electrophoretic fine particles. In the middle period, display DC electric field is applied, black loaded electromagnetic fine particles are moved vertically to the display surface, white positively charged fine particles are moved vertically to the non-display surface, and in the latter period, the AC electric field is excluded and image display is performed. . In the second step, an AC electric field and a peeling DC electric field are applied to erase the previous history display image. In the third step, a negative DC electric field is applied to whiten the entire display surface, and the operation ends.

FIG. C shows an AC electric field / magnetic induction system. In the stirring process, an alternating electric field and an alternating magnetic field are superimposed. Electrophoretic particles are black-loaded electromagnetic particles and white positively charged particles. The superposition of the alternating electric field and the alternating magnetic field completely separates the positive and negative migrating fine particles. Similarly to the above, the first step is divided into three stages of the first period, the middle period, and the latter period. First, an alternating electric field and an alternating magnetic field are applied between the first substrate and the second substrate, both charged fine particles are stirred by the alternating electric field, and the charged magnetic fine particles are stirred by the alternating magnetic field. Ensure that the fine particles are separated.
In the middle period, DC electric field for display is applied, black loaded electromagnetic fine particles move vertically to the display surface, white positively charged fine particles move vertically to the non-display surface, and in the latter period, the AC electric field and AC magnetic field are excluded, Display images only in the world. In the second step, an AC electric field, an AC magnetic field, and a peeling DC electric field are applied to erase the previous history display image. In the third step, a DC electric field is applied to whiten the entire display surface, and the operation ends.

  FIG. 3 shows an example of the operating state of the electrophoretic fine particles in the electrophoretic display element according to the AC electric field system of the present invention. The electrophoretic display element includes a first substrate 1, a first transparent electrode 2, a transparent insulating layer 3, a first transparent driving electrode 6, a transparent insulating layer (display surface) 7 disposed on the first substrate, A second substrate 17 disposed opposite to one substrate, a second electrode 16, an insulating layer 13, a second drive electrode 12, an insulating layer (non-display surface) 11 disposed on the second substrate 17; Positive / negative 2 between the transparent insulating liquid 10 filled between the first substrate 1 and the second substrate 17, the black negatively charged fine particles 8 dispersed in the transparent insulating liquid, and the white positively charged fine particles 9. It is an electrophoretic display element that encloses various types of electrophoretic fine particles and moves vertically.

In the first stage of the first step, an AC power source 22 is connected between the first transparent electrode 2 and the second electrode 16, a peeling DC electric field is applied between the first transparent driving electrode 6 and the second driving electrode 12, and the AC electric field is transparent. The insulating liquid 10 is agitated to erase the previous history display image, separate the black negatively charged fine particles 8 and the white positively charged fine particles 9, and uniformly distribute the dispersed migrating fine particles in the transparent insulating liquid 10. When the display DC electric field 21 is applied simultaneously with stirring in the middle period, the charged fine particles are separated and the black negative charged fine particles 8 are moved to the display surface 7 and the white positively charged fine particles 9 are moved to the non-display surface 11 so that the migrating fine particles are replaced. . In order to obtain a good display image quality, a later process of only the display DC electric field 21 is required except for the AC electric field. As a result, an electrophoretic display element having a contrast composed of white and black electrophoretic fine particles can be obtained.
In the second step, the AC power supply 22 is connected between the first transparent electrode 2 and the second electrode 16 in the process of erasing the previous history display image, and adsorbed to the insulating layer (display surface) 7 and the insulating layer (non-display surface) 11. Delete the previous history display image. When the erasing is insufficient, a DC electric field having the same polarity as the electrophoretic fine particles is applied to electrostatically peel the electrophoretic fine particles from the display surface.
The third step is a step for making the entire display screen white. A negative DC electric field is applied to the first transparent electrode side, white charged fine particles are collected on the display surface, and the operation ends.
In order to obtain a white display, in the first step, the polarity of the display DC power supply 21 is reversed, a negative DC electric field is applied to the first drive electrode 6, a positive DC electric field is applied to the second drive electrode 12, and white positively charged fine particles are applied. 9 may be moved to the display surface 7, and the black charged fine particles 9 may be moved to the non-display surface 11. If the black charged fine particles are replaced with magenta, yellow, and cyan charged fine particles, a color electrophoretic display element is obtained with the same electrophoretic display element configuration.

  FIG. 4 shows an example of the operating state of the electrophoretic fine particles in the electrophoretic display element according to the magnetic induction system of the present invention. The configuration of the electrophoretic display element includes a first substrate 1, a second transparent electrode (coiled electrode for thin film magnetic field generation) 4 disposed on the first substrate, a transparent insulating layer 5, a first transparent drive electrode 6, a transparent An insulating layer (display surface) 7, a second substrate 17 disposed opposite to the first substrate 1, and a third electrode (coiled electrode for generating a thin film magnetic field) 14 disposed on the second substrate 17. , The insulating layer 13, the second drive electrode 12, the insulating layer (non-display surface) 11, the transparent insulating liquid 10 filled between the first substrate 1 and the second substrate 17, and the transparent insulating liquid 10 This is an electrophoretic display element that encloses two kinds of positive and negative electrophoretic fine particles, that is, dispersed black loaded electromagnetic fine particles 20 and white positively charged fine particles 9, and moves vertically.

In the first stage of the first step, an AC magnetic field generating AC power source 23 is connected between the second transparent electrode 4 and the third electrode 14, a peeling DC electric field is applied between the first transparent driving electrode 6 and the second driving electrode 12, The black load electromagnetic fine particles 20 dispersed in the transparent insulating liquid 10 by the AC magnetic field are stirred, the previous history display image is erased, the black load electromagnetic fine particles 20 and the white positively charged fine particles 9 are separated, and the transparent insulating liquid 10 Uniform distribution of migrating fine particles dispersed in the medium is performed. When the display DC electric field 21 is applied simultaneously with stirring in the middle period, the electrophoretic microparticles are separated, the black negatively charged microparticles 20 are moved to the display surface, the white positively charged microparticles 9 are moved to the non-display surface 11, and the electrophoretic microparticles are replaced. Is called. In order to obtain a good display image quality, it is necessary to exclude the AC electric field and only the display DC electric field 21 later. As a result, an electrophoretic display element having a contrast composed of white and black electrophoretic fine particles can be obtained.
In the second step, an AC power source 23 that generates an AC magnetic field is connected between the second transparent electrode 4 and the third electrode 14 in the process of erasing the previous history display image, and the insulating layer (display surface) 7 and the insulating layer (non-display) Surface) The previous history display image adsorbed to 11 is erased. When the erasing is insufficient, a DC electric field having the same polarity as the electrophoretic fine particles is applied to electrostatically peel the electrophoretic fine particles from the display surface.
The third step is a step for making the display screen 7 entirely white. A negative DC electric field is applied to the first transparent electrode side, white charged fine particles 9 are collected on the display surface 7, and the operation is completed.

  FIG. 5 shows an example of the operating state of the electrophoretic fine particles in the electrophoretic display element using the AC electric field / magnetic induction system of the present invention. The electrophoretic display element is composed of a first substrate 1, a first transparent electrode 2 disposed on the first substrate, a transparent insulating layer 3, a second transparent electrode (coiled electrode for generating a thin film magnetic field) 4, and a transparent insulating layer. 5, the first transparent drive electrode 6, the transparent insulating layer (display surface) 7, the second substrate 17 disposed opposite to the first substrate 1, and the second electrode disposed on the second substrate 17. 16, insulating layer 15, third electrode (coiled electrode for thin film magnetic field generation) 14, insulating layer 13, second drive electrode 12, insulating layer (non-display surface) 11, and between first substrate 1 and second substrate 17 Electrophoretic display by vertical movement in which transparent insulating liquid 10 filled in, black loaded electromagnetic fine particles 20 dispersed in the transparent insulating liquid, and two types of positive and negative electrophoretic fine particles of white positive charged fine particles 9 are enclosed. It is an element.

In the first stage of the first step, an AC power source 22 is connected between the first transparent electrode 2 and the second electrode 16, and an AC power source 23 for generating an AC magnetic field is connected between the second transparent electrode 4 and the third electrode 14. 1. A peeling DC electric field is applied between the transparent driving electrode 6 and the second driving electrode 12, and the transparent insulating liquid 10 is stirred by the AC electric field, the AC magnetic field, and the peeling DC electric field, the previous history display image is erased, and the black load is applied. The electromagnetic fine particles 20 and the white positively charged fine particles 9 are separated, and the dispersed fine particles are uniformly distributed.
In the middle period, when the display DC power supply 21 is applied simultaneously with stirring, the electrophoretic fine particles are separated, the black negatively charged fine particles 20 are vertically moved to the display surface 7, and the white positively charged fine particles 9 are vertically moved to the non-display surface 11. However, in order to obtain a good display image quality, only the display direct-current power supply 21 is required after the AC electric field is excluded. As a result, an electrophoretic display element having a contrast composed of white and black electrophoretic particles can be obtained.
In the second step, an AC power supply 22 is applied between the first transparent electrode 2 and the second electrode 16 and simultaneously an AC magnetic field is generated between the second transparent electrode 4 and the third electrode 14 in the process of erasing the previous history display image. An AC power source 23 was connected, and a DC electric field for separation having the same polarity as the electrophoretic fine particles was applied to the first and second drive electrodes 6 and 12 to adsorb the insulating layer (display surface) 7 and the insulating layer (non-display surface) 11. Delete the previous history display image.
The third step is a step for making the entire display screen white. A negative DC electric field is applied to the first transparent electrode side, white positively charged fine particles 9 are collected on the display surface 7, and the operation is completed.

FIG. 6 is a manufacturing flowchart and a cross-sectional view of an electrophoretic display device using an AC electric field method. For convenience, it is shown by 4 pixels. The first substrate 1 is transparent nesa glass. As the transparent electrode material, indium tin oxide (ITO), zinc oxide, or the like is used. This is patterned by photolithography to form a first transparent electrode 2, and a polycarbonate film is applied by about 20 to 50 μm by spinner coating to form a transparent insulating layer 3. The first transparent drive electrode 6 is formed by sputtering and patterning ITO on the surface. Again, a polycarbonate film is applied in an amount of 20 to 50 μm by spin coating to form a transparent insulating layer (display surface) 7, and further, a photoresist is applied thereon and patterned to form partition walls. A transparent insulating liquid 10 in which electrophoretic fine particles are dispersed is applied to the recess, and excess liquid is removed with a blade. The concave square partition walls have a depth of 100 to 150 μm and a width of 60 μm, and the square partition walls have a width of 10 to 20 μm.
The second substrate 17 is also transparent nesa glass. The second electrode 16 is formed by patterning the nesa electrode to form the second electrode 16, applying about 20 to 50 μm of the polycarbonate film 13, and sputtering ITO on the surface. The spinner is coated again, and a polycarbonate film is applied by 20 to 50 μm to form an insulating layer (non-display surface) 11, which is bonded to the first substrate to form an AC electric field type electrophoretic display device.

  FIG. 7 is a cross-sectional view and a 3 × 3 matrix plan view of an electrophoretic display device using an alternating electric field system. In order to maintain the resolution of 300 dpi, the electrophoretic display element is a prism having a side of 60 to 70 μm and a height of 100 to 150 μm, and the width of the partition wall is about 20 μm. FIGS. A and b are reflection type AC electric field type electrophoretic display devices, and FIGS. C and d are transmissive types in which transmitted light is effectively utilized through light irradiation from the back through the partition walls of the electrophoretic display element. An electrophoretic display device.

FIG. 8 is a manufacturing flowchart and a sectional view of an electrophoretic display device using a magnetic induction method. For convenience, it is shown by 4 pixels. The first substrate 1 is transparent nesa glass. As the transparent electrode material, indium tin oxide (ITO), zinc oxide, or the like is used. A transparent electrode on Nesa glass is patterned by photolithography to form a coiled surface electrode for generating a thin film magnetic field, and an insulating layer is formed on the surface by spin coating of polycarbonate with 20 to 50 μm, and a transparent electrode material is sputtered and patterned to form a thin film magnetic field. The first transparent electrode 4 is constituted by conducting the front and back as the back electrode of the generating coil. FIG. 9 shows the configuration of a coiled electrode for generating a thin film magnetic field.
A polycarbonate film is applied to the surface by spinner coating to a thickness of about 20 to 50 μm to form a transparent insulating layer 5, and ITO is sputtered and patterned on the surface to form the first transparent drive electrode 6. Again, a polycarbonate film is applied by spinner coating to a thickness of 20 to 50 μm to form a transparent insulating layer (display surface) 7, and further, a photoresist is applied thereon and patterned to form partition walls, and the migrating particles in the recesses A transparent insulating liquid 10 in which 8 and 9 are dispersed is applied, and excess particles are removed with a blade.
The second substrate 17 is similarly transparent nesa glass. As with the first transparent electrode 4, the nesa film is patterned to form a coiled surface electrode for generating a thin film magnetic field, polycarbonate is coated on the surface with a 20 to 50 μm spinner to form an insulating layer, and a transparent electrode material is sputtered and patterned. Thus, the back electrode of the thin-film magnetic field generating coil is used, and the second electrode 14 is formed by conducting the front and back. A polycarbonate is applied by spinner coating to 20 to 50 μm to form an insulating layer (non-display surface) 11 and bonded to the first substrate 1 to obtain a magnetic induction type electrophoretic display device.

  FIG. 10 is a cross-sectional view and a 3 × 3 matrix plane configuration diagram of an electrophoretic display device using a magnetic induction method. In order to maintain the resolution of 300 dpi, the electrophoretic display element is a prism having a side of 60 to 70 μm and a depth of 100 to 150 μm, and the width of the partition wall is about 20 μm. FIGS. A and b are reflection type AC electric field type electrophoretic display devices, and FIGS. C and d are transmissive types in which transmitted light is effectively utilized through light irradiation from the back through the partition walls of the electrophoretic display element. An electrophoretic display device.

FIG. 11 is a manufacturing flowchart and a sectional view of an electrophoretic display device using an alternating electric field / magnetic induction method. For convenience, it is shown by 4 pixels. The first substrate 1 is transparent nesa glass. As the transparent electrode material, indium tin oxide (ITO), zinc oxide, or the like is used. This is patterned by photolithography to form the first transparent electrode 2, and a polycarbonate film is applied by 20 to 50 μm by spinner coating to form the transparent insulating layer 3. ITO is sputtered on the surface and patterned to form a surface electrode of a thin-film magnetic field generating coil. Further, the surface is coated with a spinner-coating polycarbonate and an insulating layer is applied in a thickness of 20 to 50 μm. The surface is sputtered with ITO again and patterned to form a back electrode of a coil for generating a thin film magnetic field. Constitute.
A polycarbonate film of 20 μm is applied to the surface to form the insulating layer 5, and ITO is sputtered again and patterned to form the first transparent drive electrode 6. Further, a polycarbonate film is applied to the surface by spinner coating to form 10 to 20 μm to form an insulating layer (display surface) 7, and a photoresist is applied on top of that and patterned to form partition walls, and in the recesses A transparent insulating liquid 10 in which electrophoretic particles are dispersed is applied, and excess particles are removed with a blade to manufacture the first substrate 1.
The second substrate 17 is also transparent nesa glass. The transparent electrode is patterned to form the second electrode 16, and the third electrode (coiled electrode for generating a thin film magnetic field) 14 is manufactured in the same manner as the first transparent electrode 4. An insulating layer 13 is applied, a transparent electrode material is sputtered, and patterned to form the second drive electrode 12. Furthermore, 20-50 micrometers of polycarbonate films | membranes were apply | coated and the insulating layer (non-display surface) 11 was formed.
The first substrate 1 and the second substrate 17 are bonded together to form an AC electric field / magnetic induction type electrophoretic display device.

  FIG. 12 is a cross-sectional view and a 3 × 3 matrix plan view of an electrophoretic display device using an alternating electric field / magnetic induction method. In order to maintain the resolution of 300 dpi, the electrophoretic display element is a prism having a side of 60 to 70 μm and a depth of 100 to 150 μm, and the width of the partition wall is about 10 μm. FIGS. A and b are reflection type AC electric field type electrophoretic display devices, and FIGS. C and d are transmissive types in which transmitted light is effectively utilized through light irradiation from the back through the partition walls of the electrophoretic display element. An electrophoretic display device.

  The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications, design changes, and the like within the technical scope of the present invention are included in the technical scope.

The invention's effect

As described above in detail, the present invention has the following effects.
First, by applying an alternating electric field, electrophoretic charged fine particles dispersed in a transparent insulating liquid are agitated, the erasure of previous display images, separation, precipitation, secondary aggregation, uniform distribution, etc. are solved, resulting in fine and high contrast. High quality display is now possible.

  Secondly, the combination of charged magnetic fine particles and non-magnetic charged fine particles solves the problem of stirring the transparent insulating liquid by the alternating magnetic field, separating the migrating fine particles, erasing the previous history display image, precipitation, secondary aggregation, uniform distribution, etc. High-definition and high-contrast high-quality display is now possible.

  Third, the combination of charged magnetic particles and non-magnetic charged particles superimposes alternating electric field and alternating magnetic field, and independently stirs the non-magnetic charged particles and charged magnetic particles dispersed in the transparent insulating liquid for higher efficiency. This eliminates the separation of migrating microparticles, image erasure, precipitation, secondary aggregation, uniform distribution, etc., enabling higher definition and higher contrast and higher quality display.

  Fourth, polymer fine particle material added with an electron trap is polymerized into spherical particles, and this is irradiated with radiation to polymerize the polymer fine particle material added with a hole trap material to negatively charged fine particles, Electrophoretic fine particles, which are made into true spherical fine particles and irradiated with radiation to form positively-charged fine particles, enable electrophoretic display with excellent particle size distribution, chargeability, high definition, and fluidity.

  Fifth, the polymer fine particle material in which the electron trap and the magnetic fine particles are mixed is polymerized into a spherical particle, which is irradiated with radiation to form a loaded electromagnetic fine particle. Electrophoretic display with excellent definition and fluidity is now possible.

  Sixth, in an electrophoretic display element having a square partition wall, a good display contrast without a crosstalk phenomenon is obtained, and a reflective electrophoretic display device can be realized by simple matrix and active matrix driving.

  Seventh, a transmission type electrophoretic display device can be realized by light irradiation from the back surface.

  Eighth, a color electrophoretic display device can be realized by using charged fine particles such as magenta, yellow, and cyan, and charged magnetic fine particles.

It is sectional drawing which shows the basic composition of the electrophoretic display element of this invention. I. AC electric field system II. Magnetic induction system III. AC electric field / magnetic induction It is a figure which shows the typical drive method of the electrophoretic display element of this invention. a) AC electric field method b) Magnetic induction method c) AC electric field / magnetic induction method It is a schematic diagram which shows the behavior of the electrophoretic particle in the electrophoretic display element by the alternating current electric field system of the present invention. 1st process: 1st period, 2nd period, 3rd process. It is a schematic diagram which shows the behavior of the electrophoretic particle in the electrophoretic display element by the magnetic induction system of this invention. 1st process: 1st period, 2nd period, 3rd process. It is a schematic diagram which shows the behavior of the electrophoretic particle in the electrophoretic display element by the alternating current electric field / magnetic induction system of the present invention. 1st process: 1st period, 2nd period, 3rd process. It is a manufacture flowchart and sectional drawing of the electrophoretic display device by an alternating current electric field system by the present invention. FIG. 3 is a cross-sectional view and a 3 × 3 matrix plane configuration diagram of a reflection type and transmission type electrophoretic display element array according to an AC electric field method according to the present invention. 6 is a manufacturing flowchart and a cross-sectional view of an electrophoretic display device using a magnetic induction method according to the present invention. It is the schematic of the 1st transparent electrode (coil for thin film magnetic field generation) 4 by the magnetic induction system by this invention. FIG. 4 is a cross-sectional view and a 3 × 3 matrix plane configuration diagram of a reflective and transmissive electrophoretic display element array using a magnetic induction method according to the present invention. It is a manufacture flowchart and sectional drawing of an electrophoretic display device by an alternating current electric field and a magnetic induction system by the present invention. FIG. 4 is a cross-sectional view and a 3 × 3 matrix plane configuration diagram of a reflection type and transmission type electrophoretic display element array using an AC electric field / magnetic induction method according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... 1st board | substrate 2 ... 1st transparent electrode 3 ... Transparent insulating layer 4 ... 2nd transparent electrode 5 ... Transparent insulating layer 6 ... 1st transparent drive electrode 7 ... Insulating layer 8 ... Black negatively charged fine particles 9 ... White positively charged fine particles 10 ... Transparent insulating liquid 11 ... Insulating layer 12 ... Second drive electrode 13 ... Insulating layer 14 ... 3rd electrode 15 ... Insulating layer 16 ... 2nd electrode 17 ... 2nd board | substrate 18 ... Display element 19 ... Partition 20 ... Black load electromagnetic fine particle 21 ... Direct current for display Power source 22 ... AC power source for stirring 23 ... Magnetic field generating power source for stirring

Claims (18)

A first substrate, a first transparent electrode, a transparent insulating layer, a first transparent driving electrode and a transparent insulating layer (display surface) disposed on the first substrate, and a second disposed facing the first substrate; A substrate, a second electrode, an insulating layer, a second drive electrode and an insulating layer (non-display surface) disposed on the second substrate, and a transparent insulating liquid filled between the first substrate and the second substrate And an electrophoretic display device comprising black negatively charged fine particles dispersed in the transparent insulating liquid and two positive and negative charged fine particles such as white positively charged fine particles or color negatively charged fine particles and white positively charged fine particles. It is a display method.
First, an AC electric field is applied between the first transparent electrode and the second electrode, and the transparent insulating liquid is stirred in an AC electric field to separate positive and negative charged fine particles. At the same time, the first transparent drive electrode and the second electrode A first process of applying a direct current electric field for display between the drive electrodes and moving vertically to move the fine particles to the transparent insulating layer (display surface) or non-display surface, and again after the display, the first transparent electrode and the first transparent electrode An AC electric field is applied between the two electrodes, the transparent insulating liquid is stirred with an AC electric field, and the display is terminated by a second process of erasing the previous display and a third process of displaying the entire display screen in white. A monochrome or color electrophoretic display element using an alternating electric field system and a monochrome or color electrophoretic display method. A first substrate, a thin-film coil-shaped first transparent electrode for generating a magnetic field, a transparent insulating layer, a first transparent driving electrode, an insulating layer (display surface) disposed on the first substrate, and facing the first substrate A second substrate disposed; a thin-film coiled third electrode for generating a magnetic field disposed on the second substrate; an insulating layer; a second drive electrode; and an insulating layer (non-display surface); the first substrate; A transparent insulating liquid filled between the second substrates, black loaded electromagnetic fine particles dispersed in the transparent insulating liquid, white positively charged fine particles, or color loaded electromagnetic fine particles and white positively charged fine particles, etc. An electrophoretic display element including two types of positive and negative electrophoretic fine particles and a display method.
First, an alternating current is passed between the first transparent electrode and the third electrode to generate an alternating magnetic field, and the transparent insulating liquid is stirred with the alternating magnetic field to separate positive and negative fine particles, and at the same time, the first transparent drive A first step of applying a direct current electric field for display between the electrode and the second drive electrode and vertically moving the fine particles to the transparent insulating layer (display surface) or the non-display surface; A second process of generating a magnetic field by passing an alternating current between the transparent electrode and the third electrode, stirring the transparent insulating liquid by the magnetic field and erasing the previous history display, and further displaying the entire display screen in white. An electrophoretic display method using a magnetic induction system, wherein display is terminated by three processes. First substrate, first transparent electrode, transparent insulating layer, thin film coiled second transparent electrode for generating magnetic field, transparent insulating layer, first transparent driving electrode, transparent insulating layer (display surface) arranged on first substrate A second substrate disposed opposite to the first substrate, a second electrode, an insulating layer, a thin film coiled third electrode for generating a magnetic field, an insulating layer, and a second layer disposed on the second substrate. A drive electrode, an insulating layer (non-display surface), a transparent insulating liquid filled between the first substrate and the second substrate, black load electromagnetic fine particles dispersed in the transparent insulating liquid, and white An electrophoretic surface plate and an electrophoretic display method comprising positively charged microparticles or two types of positive and negative electrophoretic particles such as color-loaded electromagnetic fine particles and white positively charged fine particles.
First, an alternating electric field is applied between the first transparent electrode and the second electrode, and simultaneously, an alternating current is applied to the second transparent electrode and the third electrode to generate a magnetic field. Stir the insulating liquid and separate positive and negative fine particles to promote fluidity. At the same time, a direct current electric field for display is applied between the first transparent drive electrode and the second drive electrode, and the electrophoretic particles are moved vertically to the display surface or the non-display surface. A second process of generating an alternating electric field between the first transparent electrode and the third electrode, and simultaneously generating a magnetic field between the second transparent electrode and the third electrode, stirring the transparent insulating liquid and erasing the previous history display; An electrophoretic display method using an alternating electric field / magnetic induction method, wherein the display is terminated by a third process of displaying the entire display screen in white.   In the first process of claim 3, the migrating fine particles are adsorbed onto the transparent insulating layer (display surface) on the first transparent driving electrode disposed on the first substrate to display an image. A positive DC electric field signal is displayed on the first transparent drive electrode for black display. For white display, a negative DC electric field signal is applied to display an image. The superposition of an alternating electric field and a magnetic field efficiently stirs the transparent insulating liquid, and the charged magnetic fine particles and nonmagnetic positively charged fine particles increase the fluidity. 4. The electrophoretic display method according to the AC electric field / magnetic induction method according to claim 3, wherein the image is moved in the direction of the display surface and the fine particles are exchanged to display an image having a desired contrast. In the second process of claim 4, when the previous history display image is insufficiently erased, a DC electric field having the same polarity as the electrophoretic fine particles is applied to the first transparent drive electrode and the second drive electrode, and the previous history display image is displayed. It is electrically separated from the display surface and non-display surface. Simultaneously, an AC electric field is generated between the first transparent electrode and the fourth electrode, and a magnetic field is generated between the second transparent electrode and the third electrode. An electrophoretic display method that stirs the insulating liquid and completely erases the previous display image.   When performing display writing again, if the previous history display image is insufficiently erased, the first floor repeats the second process to stir the transparent insulating liquid to completely erase the previous history display image. 4. An electrophoretic display system and an electrophoretic display element according to claim 1, wherein the electrophoretic display system and the electrophoretic display element are moved between a first transparent drive electrode and a second drive electrode to display an image on the display surface.   The electrophoretic display device according to any one of claims 1 to 3, wherein the second substrate, the second electrode, the third electrode, the insulating layer, the second driving electrode, and the insulating layer (non-layered) disposed on the second substrate and the second substrate. A monochrome and color electrophoretic display device characterized in that a display surface) is made of a translucent material so that transmitted light can be irradiated from below.   The monochrome and color according to any one of claims 4 to 7, wherein the electrophoretic display elements of the AC electric field system according to claim 1 are assembled and integrated to display by a simple matrix or active matrix driving method. Electrophoretic display device.   The monochrome and color electrophoresis according to any one of claims 4 to 7, wherein the electrophoretic display elements according to claim 2 are assembled, integrated, and displayed by a simple matrix or an active matrix circuit. Display device.   The monochrome and color according to any one of claims 4 to 7, wherein the electrophoretic display elements of the AC electric field / magnetic induction system according to claim 3 are assembled, integrated, and displayed by a simple matrix or an active matrix circuit. Electrophoretic display device.   The white positively charged fine particles have a particle size of 1 to 2 by suspension polymerization method by adding Si oxide ultrafine particles having a particle size of 0.1 μm and white pigments such as titanium oxide and zinc oxide as hole traps to the polymer fine particle material. 10 μm spherical ultrafine particles are formed, and 5-10 kGy of gamma rays are irradiated to the particles to form white positively charged fine particles having a ζ potential of 20-100 mV. The particles are spherical ultrafine particles and have a narrow particle size distribution, so they are positively charged fine particles that are dispersed in a transparent insulating liquid, regularly move at a high speed when a display DC electric field is applied, and respond in a short time.   The black negatively charged fine particles and the color negatively charged electromagnetic fine particles are added to a polymer fine particle material colored black or magenta, yellow, cyan, etc., by adding a fluorine resin as an electron trap material, and by suspension polymerization, The particles are 10 μm spherical fine particles, irradiated with an electron beam of 50 to 100 kGy, and black negative charged fine particles having a ζ potential of −20 to −100 mV. Since it has a spherical shape and a narrow particle size distribution, it is a negatively charged fine particle that disperses in a transparent insulating liquid, moves regularly at a high speed when a display DC electric field is applied, and responds in a short time. The black loaded electromagnetic fine particles may be magnetic fine powder particles having a particle size of 0.1 μm or less, such as Pt—Co, MnBi ferrite, YIG, and the like, by adding a fluorine resin as an electron trap material to black colored polymer fine particle material, Nano magnetic fine particles such as SmCo ₅ , Fe—Pt, CoPt, etc. are added to obtain spherical ultrafine particles having a particle diameter of 1 to 10 μm by suspension polymerization, irradiated with an electron beam of 50 to 100 kGy, and a ζ potential of −20 to − 100 mV black loaded electromagnetic fine particles. The color-loaded electromagnetic fine particles have a particle size of 1 by adding a fluorine resin as an electron trap material to a polymer fine particle material colored in magenta, yellow, cyan, or the like, adding white magnetic fine particles such as YIG, and suspension polymerization. 10 to 10 μm spherical fine particles, which were irradiated with radiation in the same manner as described above to form color-loaded electromagnetic fine particles. Since the particle size distribution is narrow, the color-loaded electromagnetic particles are dispersed in a transparent insulating liquid, regularly move at high speed when a display electric field is applied, and respond in a short time.   The white positively charged magnetic fine particles are suspended by adding Si-based oxide fine particles as hole traps to the polymer fine particle material, adding white pigments such as titanium oxide and zinc oxide, and white magnetic fine particles such as YIG. The spherical ultrafine particles having a particle diameter of 1 to 10 μm are formed by a polymerization method and irradiated with 5 to 10 kGy of gamma rays to form white positively charged magnetic particles having a ζ potential of +20 to +100 mV. Since it is a spherical ultrafine particle and has a narrow particle size distribution, it is a white positively charged magnetic fine particle that disperses in a transparent insulating liquid, moves regularly at high speed when a display electric field is applied, and responds in a short time.   The electrophoretic display element and the electrophoretic display device according to claim 1, wherein an average particle diameter of the electrophoretic particles is 1 to 10 μm or less.   The electrophoretic display element and the electrophoretic display device according to claim 1, wherein the first substrate and the second substrate are made of glass or polymer film.   11. The electrophoretic display element and the electrophoretic display device according to claim 1, wherein a distance between the first substrate and the second substrate is 20 times the particle diameter of the fine particles or 150 μm or less.   For the electrophoretic display element, black positively charged magnetic fine particles and white loaded electromagnetic fine particles can also be used. In this case, the display DC electric field needs to have a reverse polarity. In addition, magnetic fine particles and non-magnetic fine particles can be exchanged for white and black, but magnetic fine particles are 2 to 5 times larger than non-magnetic fine particles, which is effective for electric and magnetic field separation. It is.

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