JP2002350906A - Reversible image display medium, image display method and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rewritable reversible image display medium which enable rewriting in an once displayed image simply and easily, and can thereby hold the same image for a long period of time, and to provide an image display method and an image display device. SOLUTION: The reversible image display medium TP is provided with an image display part 11 in which an image can be rewritten, and a nonvolatile memory M for storing image data corresponding to the image to be displayed on the image display part 11. The image display method includes a write process in which the image is written in the image display part 11 on the basis of the image data corresponding to the image to be displayed and which writes and stores the image data in the memory M, and a rewrite process in which the image data stored in the memory M are read and the image is rewritten in the image display part 11 on the basis of the read image data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a reversible image display medium, an image display method and an image display device.

[0002]

2. Description of the Related Art Today's image displays include pencils, pens,
Write characters, graphics, etc. manually on an image display medium, such as paper, using paints, etc., display documents, graphics, etc., created by a computer, word processor, etc. on a display such as a CRT display, or print on a paper, etc. This is done by, for example, displaying an output on a medium.

Further, a document, a figure, or the like, which is manually created on a medium such as paper, or a document, a figure, or the like on a medium such as paper output by a printer is printed on another medium such as paper using a copying machine or the like. In some cases, a copy is made, or transmitted by a facsimile machine or the like, and copied and output on a medium such as paper at a transmission destination.

[0004] Among these image displays, an image display for displaying characters, figures, and the like on an image display medium such as paper using a pencil, a pen, or the like, a printer using an electrophotographic system, an ink spraying system, a thermal transfer system, etc. In the image display in which characters, graphics, and the like are displayed on an image display medium such as paper by an image forming apparatus such as an image forming machine or a facsimile machine, the images can be clearly displayed at a high resolution, and the images are easy for human eyes to see.

However, it is not possible to repeat image display and image deletion on an image display medium such as paper. When writing letters and the like with a pencil, the letters and the like can be erased to some extent with an eraser, but if the letters etc. are thinly written, they will be completely erased if they are written with normal darkness. It is difficult to leave, and it is difficult to reuse a medium, such as paper, on which an image has been displayed, unless the image is also displayed on the back side of the medium on which an image has not been displayed.

[0006] Therefore, a medium such as paper on which an image is displayed is discarded or incinerated after it has been used up, and a lot of resources are consumed. In printers and copiers, consumables such as toner and ink are also consumed. Further, in order to obtain a display medium such as new paper, toner, ink, and the like, resources such as a medium and energy for manufacturing the medium are further required. This is contrary to the demand for environmental load reduction required today.

[0007] Recently, digital paper, which can be handled like paper, can rewrite images,
When rewriting an image, it consumes energy (for example, power), but can maintain a display image while displaying the image even after the supply of energy is stopped (for example, after power is turned off) (so-called memory rewriting). Reversible image display media have been proposed.

Such digital paper (rewritable reversible image display medium) has the advantages of a so-called soft copy such as a display (advantages such as rewritable, combination with digital information, resource saving, etc.) and a paper such as paper. It also has the advantages of a so-called hard copy (e.g., advantages such as easy-to-see, easy-to-carry, and good storage stability).

Conventionally proposed digital papers include an electrophoretic display (EPD) medium and a twisted ball display (TBD) medium.

The electrophoretic display medium forms a sealed space by arranging two substrates, at least one of which is transparent, facing each other with a space therebetween via a spacer, in which particles having electrophoretic ability are formed. It is filled with a display liquid dispersed in a dispersion medium of a different color, and displays images in the color of the particles or the color of the dispersion medium by migrating particles in the display liquid in an electrostatic field. is there.

Such a display liquid usually comprises a dispersion medium such as an isoparaffin type, fine particles such as titanium dioxide, a dye for imparting color contrast to the fine particles, a dispersant such as a surfactant, and additives such as a charge imparting agent. Is done.

The twisted ball type display medium holds a large number of microcapsules in which microspheres treated so that the half and the other half of the surface exhibit different colors or optical densities together with the insulating liquid therein. An image display medium for displaying images in a predetermined color by rotating microspheres in the microcapsules by electric or magnetic force.

More recently, media using powder particles,
For example, "Japan Hardcopy '99 Transactions PP249-252"
Has been proposed.

"Japan Hardcopy '99 Transactions PP249
In the image display medium introduced in the above-mentioned publication, two substrates each having an electrode and a charge transport layer laminated thereon are opposed to each other at a predetermined interval to form a sealed space, in which a conductive toner and a conductive toner and a conductive toner are formed. Insulating particles having different colors are enclosed, an electrostatic field is applied to charge and charge the conductive toner, and the conductive toner is moved by Coulomb force to display an image.

However, in any of these reversible image display media, the image holding property (image holding period) when energy (for example, power) is not supplied is lower (short) as compared with paper or the like, that is, with time. This causes a problem that the displayed image is disturbed or disappears. Possible causes for this include, for example, a decrease in the electrostatic force in the case of image display using electrostatic force, and aggregation and sedimentation of fine particles.

In this way, it is inferior to conventional papers and the like in that images cannot be held for a long period of time.

It is an object of the present invention to provide a rewritable reversible image display medium which enables a once displayed image to be rewritten easily and easily, thereby keeping the same image for a long time. I do.

The present invention also relates to an image display method for displaying an image on a rewritable reversible image display medium, wherein an image once displayed on the medium can be simply and easily rewritten on the medium, whereby the same image can be displayed. It is an object to provide an image display method capable of displaying an image for a long time.

The present invention also provides an image display device for displaying an image on a rewritable reversible image display medium, wherein an image once displayed on the medium can be simply and easily rewritten on the medium. The task is to provide.

[0020]

SUMMARY OF THE INVENTION The present invention provides the following reversible image display medium, image display method and image display apparatus to solve the above-mentioned problems. (1) Reversible image display medium A reversible image display having an image rewritable image display unit and a nonvolatile memory for storing image data corresponding to an image to be displayed on the image display unit. Medium.

According to this reversible image display medium, an image can be written in the image display section based on the image data corresponding to the image to be displayed, and the image data can be written and stored in the nonvolatile memory. When the image displayed on the image display unit deteriorates, the image data is read from the nonvolatile memory, and the same image can be easily and easily rewritten on the image display unit based on the read image data. Thus, the same image can be retained for a long time.

As such an image rewritable reversible image display medium, a medium having a reversible image display section having a memory function can be exemplified. This “reversible image display unit having memory properties” means that when rewriting an image, it consumes energy (for example, power) but displays the image even after the energy supply is stopped (for example, after the power is turned off). An image display unit that can maintain an image.

An image rewritable image display unit having such a memory function includes an electrophoretic display device which displays an image with a display liquid containing the above-mentioned (1) particles having electrophoretic ability and a dispersion medium in which the particles are dispersed. Image display unit, (2) Twisted ball type image display unit using a holding medium in which capsule units having particles rotatable by applying an electric field are dispersed, (3) “Japan Hard
copy '99 Transactions PP249-252 ".

A typical example of the twisted ball type image display unit is also known as a gyricon-based electronic paper display, and is usually in the form of a sheet, and is disclosed in US Pat. No. 4,126,854 and US Pat. 4,143,
No. 103 is an image display unit. However, it is not limited to this. That is, in the image display unit, one hemisphere and the other hemisphere present different colors (for example, one hemisphere is colored white, and the other hemisphere is colored other than white, for example, black. 2.) A two-color spherical body is enclosed in a cavity in an insulating holding medium in a state of being surrounded by a liquid or a liquid wax, and rotates in the cavity according to its electrical anisotropy by applying an external electric field according to an image. What is necessary is just to perform image display by this. Further, an image may be displayed under the action of heating exceeding the melting point of the wax and the action of an external electric field, while the image may be immobilized by cooling to a temperature substantially equal to or lower than the melting point of the wax.

In addition to the above, as the reversible image display medium according to the present invention, an image display section is formed between two substrates facing each other at a predetermined interval, and a partition wall is formed around the two substrates. And one or more developer accommodating cells surrounded by a circle, and a dry developer contained in each of the cells. The dry developers have different charging polarities and are optically reflective to each other. A reversible image display medium containing at least two kinds of dry-developed particles having triboelectricity having different concentrations can also be mentioned.

The image display section can (1) repeatedly perform image display and image erasure, and can therefore use conventional image display media such as paper and consumables such as developer and ink related to image formation. (2) High-contrast, high-quality images can be displayed, (3) High-resolution, high-quality images can be displayed, There are advantages such as a low drive voltage for image display.

At least one of the two types of dry developing particles contained in the dry developer may be magnetic developing particles. As described above, when the developer containing magnetic particles is used for displaying an image, the developer can be easily moved by applying a magnetic stirring force in a magnetic field. (2) Image display method (2-1) First image display method This is an image display method for displaying an image on the reversible image display medium described in (1) above, based on image data corresponding to an image to be displayed. An image display method for writing an image to the image display unit and writing and storing the image data in the nonvolatile memory.

According to this image display method, not only an image is written in the image display unit based on image data corresponding to an image to be displayed, but also the image data is written and stored in the nonvolatile memory. When the image displayed on the section deteriorates, the image data stored in the nonvolatile memory is read out, and the same image can be easily and easily rewritten on the image display section based on the read out image data. Thus, the same image can be retained for a long time. (2-2) Second image display method This is an image display method for displaying an image on the reversible image display medium according to the above (1), wherein image data stored in the nonvolatile memory is read, and the read image is read. An image display method including a rewriting step of rewriting an image in the image display unit based on data.

According to this image display method, the image data stored in the non-volatile memory can be read out, and the same image can be easily and easily rewritten on the image display section based on the read image data. (2-3) Third image display method This is an image display method for displaying an image on the reversible image display medium described in (1) above, wherein the writing step described in (2-1) and the (2-) An image display method including the rewriting step according to 2).

This image display method has the advantages of the first and second image display methods.

In the first and second image display methods, the rewriting step may be periodically repeated so that a good same image is always displayed. (2-4)
Further, the following can be exemplified as specific examples of the image display method according to the present invention.

A medium placement unit on which the reversible image display medium can be placed; an image writing unit for writing an image to an image display unit of the medium based on image data corresponding to an image to be displayed; And a data writing unit for writing and storing in a nonvolatile memory of the reversible image display medium arranged in the medium placement unit. A writing step of writing the image data to the non-volatile memory; and a reversible image display medium in which the image is written to the image display unit and the image data is written to the nonvolatile memory is arranged in a medium arrangement unit of the writing device. When the image can be rewritten on the image display unit, the image data stored in the non-volatile memory is deleted. Read by looking out section, an image display method comprising: a re-writing process for re-writing of the image to the image display unit by the writing unit based on image data read out.

In this image display method, a reversible image display medium in which an image is written to an image display unit and image data is written to a non-volatile memory is arranged in a medium arrangement unit of the writing device, and is transmitted to the image display unit. If the state in which the image can be rewritten continues for a predetermined time, the image may be rewritten to the image display unit periodically. (3) Image display device (3-1) First image display device This is an image display device for displaying an image on the reversible image display medium described in (1) above, based on image data corresponding to an image to be displayed. An image display device, comprising: an image writing unit that writes an image to the image display unit by writing the image data to the nonvolatile memory. (3-2) Second image display device An image display device for displaying an image on the reversible image display medium according to (1), wherein the data read unit reads image data stored in the nonvolatile memory; An image rewriting unit for rewriting an image on the image display unit based on the image data read by the data reading unit. (3-3) Third image display device The third image display device is an image display device for displaying an image on the reversible image display medium according to (1), and includes the image writing unit and the data writing unit according to (3-1). And the above (3-2)
An image display device including a data reading unit and an image rewriting unit described in (1).

In the third image display device, the image writing section and the image rewriting section may be provided separately, but a part or all may be common.

According to the first, second, and third image display devices, the first, second, and third image display methods can be respectively performed, whereby the same image is held on the image display unit for a long time. be able to.

In the second and third image display devices, the image data stored in the non-volatile memory is periodically stored in the data reading section while the reversible image display medium is mounted. A periodic rewriting control unit for causing the image rewriting unit to rewrite an image on the image display unit based on the image data read by the data reading unit is provided so that the same good image is always obtained. The information may be displayed. (3-4) Further, the following can be exemplified as specific examples of the image display device according to the present invention.

A medium placement section on which the reversible image display medium can be placed, an image writing section for writing an image based on image data corresponding to an image to be displayed on the image display section of the medium, and a nonvolatile memory of the medium And a reversible image display medium in which the image data is written in the image display unit and the image data is written in the nonvolatile memory. A detection device that is arranged in the medium arrangement unit and detects that the image can be rewritten on the image display unit of the medium, and a data reading unit that can read image data stored in the nonvolatile memory. And a control unit. The control unit transmits the image to an image display unit of a reversible image display medium arranged in a medium arrangement unit of the writing device. Writing the image based on the data and controlling the writing device to write the image data to the nonvolatile memory of the medium, the image is written to the image display unit, and the image data is written to the nonvolatile memory. When the detection device detects that the reversible image display medium has been placed in the medium placement portion of the writing device and the image can be rewritten on the image display portion, the non-volatile data is stored in the data reading portion. An image display device for controlling the writing device to read the image data from the volatile memory and to cause the writing device to rewrite an image to an image display unit based on the read image data.

In this image display device, a reversible image display medium in which an image is written to an image display unit and image data is written to a non-volatile memory is arranged in the medium arrangement unit of the writing device instead of the detection device. When a state in which the image can be rewritten on the image display unit of the medium is continued for a predetermined time or more, a detection device for detecting the state is provided. The state in which the reversible image display medium in which the image data is written in the reversible memory is arranged in the medium arrangement section of the writing device and the image can be rewritten on the image display section can be continued for a predetermined time or more. When detected by the detection device, each time the detection is performed, the data reading unit is caused to read image data from the nonvolatile memory, and based on the read data, Te configured to control the data reading unit and the writing unit so as to perform re-writing of the image to the image display unit, thereby may be periodically performs image rewriting.

Since the nonvolatile memory does not lose data even when power is not supplied and can store image data semi-permanently, an image based on the image data can be replaced with an image on the medium as necessary. It can be displayed again on the display unit.

Examples of the nonvolatile memory include a semiconductor IC memory and a magnetic tape. In addition, for example, if a small rewritable optical disk currently used can be further miniaturized and integrated with an image display medium, such a disk can be adopted.

As the image data reading section from the nonvolatile memory, a display data output device such as a personal computer or a digital camera may be used. For example, a display data output device such as a personal computer or a digital camera is connected to the writing device, the display data output device reads out image data stored in a nonvolatile memory, and sends the image data to the writing device. The writing device may rewrite (redisplay) the image on the image display unit.

The data reading section may be provided in the writing device, and the writing device may read image data from the non-volatile memory and rewrite (redisplay) the image on the image display portion. Good.

When a magnetic tape is used as the non-volatile memory, a magnetic head is provided in the writing device, and the magnetic head and the medium having the magnetic tape are scanned relative to each other. The image data may be written on the magnetic tape with a magnetic head, or a magnetic head may be provided in the image data reading unit, and the image data recorded on the magnetic tape may be read by the data reading unit. Good. The operation of reading the image data from the magnetic tape by the data reading unit and the operation of rewriting (redisplaying) the image on the image display unit by the writing device based on the image data may be separately performed. The operation and the image writing operation may be performed continuously within one scan. Further, the magnetic head may be provided separately from the writing device.

An image writing unit for writing an image on an electric field driven type reversible image display unit capable of displaying an image by forming an electric field (electrostatic field) corresponding to an image to be formed, Can be formed by using an electrostatic latent image or using a writing electrode. An image writing unit using an electrostatic latent image An electrostatic latent image corresponding to an image to be displayed is formed on one of the two substrates of the image display unit (for example, the substrate on the image observation side). Or an electrostatic latent image formed outside is brought close to and an electrostatic field is formed based on the electrostatic latent image.

In this case, the formation of the electrostatic field may be performed simultaneously with the formation of the electrostatic latent image, or may be performed after the formation of the electrostatic latent image. The electrostatic field can be formed, for example, by setting a predetermined potential for forming the electrostatic field on a substrate on which an electrostatic latent image is formed or on a substrate opposite to a substrate to be approached. The predetermined potential can be set, for example, by applying a bias to a counter electrode provided or brought into contact with the opposite substrate in advance, or by grounding the counter electrode.

The electrostatic latent image may be formed directly on the surface of the image display section (substrate surface) using, for example, a direct electrostatic latent image forming apparatus, or may be formed using an external electrostatic latent image forming apparatus. The electrostatic latent image formed outside may be transferred or formed close to the surface of the image display unit (substrate surface).

As the direct electrostatic latent image forming apparatus, various discharge-type electrostatic latent image forming apparatuses that discharge an electrostatic latent image charge by discharging to the surface of an image display unit in accordance with an image to be displayed can be used. Various types of charge injection type electrostatic latent image forming apparatuses in which electric charges are injected into the surface of the image display unit and an electrostatic latent image charge is applied in accordance with an image to be described. Examples of the former include an ion flow type device and a multi-stylus type device having an electrostatic recording head in which recording electrodes are arranged in a predetermined direction (for example, a main scanning direction when a substrate is scanned by the device). As an example of the latter, a multi-stylus type device having an electrostatic recording head in which recording electrodes are arranged in a predetermined direction (for example, a main scanning direction when a substrate is scanned by the device) and adjacent control electrodes are arranged adjacent to the recording electrodes. Can be mentioned.

The external electrostatic latent image forming apparatus forms an electrostatic latent image corresponding to an image to be displayed on an electrostatic latent image carrier, and forms the electrostatic latent image on the electrostatic latent image carrier. That is transferred or approached to the surface of the image display unit substrate. More specifically, an electrostatic latent image corresponding to an image to be displayed is formed on a photoconductor such as a photoconductor, and the electrostatic latent image on the photoconductor is transferred to the surface of the image display unit substrate. Forming an electrostatic latent image corresponding to an image to be displayed on a dielectric, or transferring or approaching the electrostatic latent image on the dielectric to the surface of the image display unit substrate. Can be exemplified.

In such an external electrostatic latent image forming apparatus, particularly an apparatus for forming an electrostatic latent image on a photoconductor such as a photoconductor, an image writing section for an image display section is usually provided with an electrostatic latent image carrier. In the case of an electrophotographic image writing unit having a photoconductor such as a photoconductor, there is an advantage that the photoconductor and the like can be shared. An image forming apparatus that uses a writing electrode The image forming apparatus includes an image writing electrode that is in contact with or close to a substrate of an image display unit, and applies a bias corresponding to an image to be displayed on the electrode.

For example, there is an individual electrode for each pixel which is in contact with or placed in close proximity to one substrate of the image display unit (for example, a substrate on the image observation side), and a counter electrode which is in contact with or is placed close to the other substrate of the display unit. An image forming apparatus having electrodes and applying a bias corresponding to an image to be displayed on each individual electrode can be given.

As an image writing unit for writing an image on a magnetically driven reversible image display unit capable of displaying an image by forming a magnetic field corresponding to an image to be formed, an image writing unit having an image writing magnetic head Can be mentioned.

Also, in the case of an image writing section for forming an image on a reversible image display section of either an electric field drive type or a magnetic drive type, the image display section is initialized or, as one type of initialization, the previous display is performed before the image display. May be included. In addition, the image display section is initialized, the previously displayed image is erased before the image is displayed, and the flowability of the developing particles is increased in displaying the image (especially in the case of the image display section of a dry-charged particle-containing medium). A developer stirring device may be included for (e.g., enhancing the fluidity of the developing particles in the display unit). Both the image erasing device and the developer stirring device may be included.

The image erasing device includes, for example, an erase electric field forming device for forming an electric field for moving the developing particles constituting the developer in the image display portion, a stirring device for applying a stirring force to the developer, or both of them. An example of the device that includes it can be given. The application of the stirring force can be performed by, for example, forming an alternating electric field, forming an oscillating magnetic field, irradiating an ultrasonic wave, applying mechanical vibration, or combining these with the developer.

As the erase electric field forming device, for example,
For the image display portion of the dry type reversible image display medium including the charged particles, one of the two types of developing particles having the same optical reflection density (in other words, “same contrast” or “same color”) A) An apparatus that forms an electric field so that the developing particles are collected on one substrate side and the other developing particles having the same optical reflection density are collected on the other substrate side. According to this device, the image display unit can be initialized or the image can be erased, and the next time a new image is formed, it is only necessary to move the developing particles in the image unit. High quality.

Such an erase electric field forming apparatus includes a pair of electrodes or dielectrics arranged with an image display section of a reversible image display medium therebetween, and a power supply device for applying a bias voltage to these electrodes or dielectrics. Can be exemplified.

In addition, various discharge-type electric field forming devices that form an electric field by discharging to an image display portion, and various charge injection-type electric field forming devices that form an electric field by injecting charges into an image display portion can be exemplified. Examples of the former include a corona charging device, an ion flow type electric field forming device, and a multi-stylus type electric field forming device having a head in which electrodes are arranged in a predetermined direction. As the latter example, electrodes are arranged in a predetermined direction. And a multi-stylus type electric field forming apparatus having a head in which adjacent control electrodes are arranged adjacent to the electrodes.

The following can be exemplified as the stirring device. A device for forming an alternating electric field on the reversible image display unit.

This device can be used when at least one of the developer particles is insulating. A device for forming an oscillating magnetic field on the reversible image display unit.

This device can be used when at least one of the developer particles contains a magnetic material.・ A device that irradiates ultrasonic waves to the reversible image display unit. A device that applies mechanical vibration to the reversible image display unit. A device combining two or more of the above devices.

Of these, the alternating electric field forming device and the oscillating magnetic field forming device are particularly effective.

[0061]

Embodiments of the present invention will be described below with reference to the drawings.

As an example of the embodiment of the present invention, a case of a reversible image display medium including dry-type charged particles will be described.

FIG. 1 shows a reversible image display medium according to the present invention (here, a dry type reversible image display medium containing charged particles).
FIG. 2 is a diagram illustrating a schematic configuration of an example.

A reversible image display medium TP shown in FIG. 1 has an image rewritable image display unit 11 and a nonvolatile memory M for storing image data corresponding to an image to be displayed on the image display unit 11. And

FIGS. 2, 3 and 4 show the image display section 11 of the reversible image display medium TP shown in FIG. The image display unit 11 shown in FIG. 2 to FIG.
And a substrate 112. These substrates 111 and 112
Are opposed to each other with a predetermined gap therebetween. Partition walls 113 are provided between the substrates 111 and 112, and the partition walls 113 ensure a predetermined gap between the substrates. That is, the partition 113 is formed on both substrates 1
Also serves as a spacer between 11 and 112. In addition, both substrates 1
11 and 112 are mutually connected and fixed by a partition 113.

The first substrate 111 is a transparent substrate, and is formed of, for example, a light transmitting plate such as transparent glass, a transparent resin film, or the like. This substrate 111 is a substrate on the image observation side.

The partition 113 is also provided with a developer containing cell 116.
(See FIG. 5). That is, the partition walls 113 are formed upright on the inner surface of the first substrate 111 in a grid pattern as shown in FIG.
A plurality of developer accommodating cells 116 are formed in a rectangular shape with a part of 13 as a partition wall.

Each partition wall has a width α and a height h, and the interval between adjacent partition walls is pt.

The first electrode 11 is provided on the inner surface of the first substrate 111.
4 are formed. The first electrode 114 is a transparent electrode in which a plurality of individual electrodes 114a are arranged in a grid pattern. Each individual electrode is formed of, for example, a transparent ITO film. The individual electrodes 114 a are arranged in each of the cells 116 at substantially the same interval as the thickness α of the wall 113. That is, here, one cell corresponds to one pixel.

The second substrate 112 is not necessarily required to be transparent, but is formed of, for example, a light-transmitting plate such as a transparent glass, a resin film, or the like.

The second electrode 115 is provided on the inner surface of the second substrate 112 facing the first substrate 111. Second electrode 1
Reference numeral 15 is continuous over the entire image display area on the inner surface of the substrate 112. The second electrode 115 is not necessarily a transparent electrode, but may be, for example, indium tin oxide (ITO).
It may be formed on a transparent electrode formed as described above.

Further, a dry developer DL containing white developing particles WP and black developing particles BP triboelectrically charged in each cell.
Is housed.

Each cell is sealed, and the developer DL does not leak from the cell.

The image display section 11 will be described more specifically. The second substrate 112 has a thickness of 50 μm here.
The second electrode 115 is formed entirely of an ITO thin film with a thickness of 500 ° by a sputtering method.

The first substrate 111 is coated with a photoresist on polyethylene terephthalate (PET) on which an ITO thin film is formed on the entire surface in the same manner as the second substrate 112, and is exposed and exposed.
It has a two-dimensional array of first electrodes 114 (group of individual pixel electrodes 114a) formed by stripping and removing the photoresist layer after patterning by development and etching.

The first electrode 11 in the image display section 11
As shown in FIG. 6, the transparent individual electrode 114a constituting the electrode 4 is a square electrode having a length of 1 mm and a width of 1 mm.
The leads 110 are connected and formed so that a voltage can be applied to each electrode.

The partition 113 is formed by repeating a thick-film resist process on a region (inter-electrode region) other than the square electrode on the first substrate 111 to form a lattice with a height h = 100 μm as shown in FIG. is there.

The grid-like partition walls 113 of the first substrate 111
(Developer accommodating cell) 116 surrounded by
L is adjusted so that the volume ratio of the developer DL with respect to the capacity of the concave portion 116 is about 30%.

The details of the developing particles and the developer in the cell are as follows. White developing particles WP 100 parts by weight of a thermoplastic polyester resin (softening point 121 ° C., glass transition point 67 ° C.), 40 parts by weight of titanium oxide (CR-50, manufactured by Ishihara Sangyo Co., Ltd.), and zinc salicylate as a negative charge control agent Complex (Orient Chemical: Bontron E)
-84) was sufficiently mixed with 5 parts by weight with a Henschel mixer, kneaded with a twin-screw extruder, and cooled.

The kneaded material was coarsely pulverized, then pulverized by a jet pulverizer, and subjected to air classification to obtain a white fine powder having a volume average particle size of 12 μm.

Thereafter, 0.3 parts by weight of hydrophobic silica particles (manufactured by Nippon Aerosil Co., Ltd .: Aerosil R-972) were added.
The mixture was mixed with a Henschel mixer to obtain white developed particles WP. Black developing particles BP Styrene-n-butyl methacrylate resin (softening point 13
100 parts by weight, 2 parts by weight of carbon black (manufactured by Lion Yushi Co., Ltd., Ketjen Black) and silica (manufactured by Nippon Aerosil Co., Ltd. 200)
And 1.5 parts by weight of a magnetite-based magnetic powder (RB-BL
After 500 parts by weight (Titanium Industry Co., Ltd.) were sufficiently mixed with a Henschel mixer, the mixture was kneaded with a vented twin-screw kneader.

After cooling the kneaded material, the mixture was coarsely pulverized by a feather mill, finely pulverized by a jet mill, and classified by an air classifier to obtain black particles BP having a volume average particle diameter of 25 μm. Developer DL The white particles WP and the black particles BP are placed in a polyethylene bottle at a ratio of 30 g of white particles and 70 g of black particles,
The mixture was stirred and mixed for 30 minutes while being rotated on a ball mill base to obtain a developer DL. The white particles were negatively charged and the black particles were positively charged. This developer DL was used.

The second substrate 112 is the first substrate 1 on which the photocurable adhesive 119a is thinly applied only on the top of the partition wall 113.
11 is adhered to the first substrate 111 by being adhered to the ITO film forming surface side, and the photocurable adhesive 119a is cured by ultraviolet irradiation. And the first and second substrates 11
Reference numerals 1 and 112 have their peripheral portions sealed and sealed with an epoxy adhesive 119b.

The individual electrode 114a is connected to the electrode selection circuit 117 via each lead 110 as shown in FIGS. A positive drive voltage generation circuit 118a, a negative drive voltage generation circuit 118b, and a display data control unit 119 are connected to the electrode selection circuit 117. A drive voltage is applied to each of the individual electrodes 114 a independently from the electrode selection circuit 117.
Reference numeral 9 denotes input of display data from a display data output device (for example, a computer, a word processor, a facsimile machine, a digital camera, etc.) not shown, and controls the electrode selection circuit 117 based on the input data. In other words, these electrode selection circuits and the like constitute an image writing unit 212 to be described later for a reversible image display unit with a counter electrode.

Thus, a bias voltage is applied to the second electrode 115 in the image display section 11 as, for example, a ground electrode or, if necessary, from a bias power supply (not shown) to the electrode 115, and the second electrode 115 is connected to the individual electrode 114a. In the meantime, a predetermined voltage is applied from the positive drive voltage generation circuit 118a or the negative drive voltage generation circuit 118b via the electrode selection circuit 117 which is controlled so that a desired image is displayed by the display data control unit 119, A predetermined electric field is formed for each pixel. Thus, as shown in FIG.
In FIG. 4, the developing particles WP and BP move from the state where the developing particles are mixed as shown in FIG. 4 according to the electric field.

According to the image display section 11, an image can be displayed, for example, as shown in FIG. In FIG. 7, Bk is a black display portion, and W is a white display portion.

In the image display section 11, the individual pixel electrodes 1
A negative voltage is applied to a pixel to be displayed in black, and a positive voltage is applied to a pixel to be displayed in white, to each of the fourteenth electrodes 114a. In this way, an image is formed by applying voltages according to the display data.

At this time, the entire surface of the image display medium is sequentially scanned while rotating the rotating magnetic pole roller R2 having a rotating magnetic pole on the front side (image observing side) or the back side (opposite side of the image observing side) of the image display section 11. By doing so, the encapsulated particles can be stirred, and the particle moving speed can be increased. In addition, the magnet plate MG in which the N pole and the S pole shown by a chain line in FIG. 4 are alternately arranged may be vibrated in the direction of arrow A in the figure.

The nonvolatile memory M shown in FIG. 1 is a bare chip of a semiconductor IC memory here, and a writing device 210 described later via an interface unit (I / F unit).
Leads to. The bare chip M is covered with a protective film or the like, and cannot be directly touched by a hand.

The non-volatile memory M does not lose data even when power is not supplied, and can store image data semi-permanently. Therefore, an image based on the image data can be stored in the medium TP as needed. It can be displayed again on the display unit 11.

According to the reversible image display medium TP described above, an image is written in the image display section 11 based on image data corresponding to an image to be displayed, and the image data is written and stored in the nonvolatile memory M. be able to. Then, when the image displayed on the image display unit 11 deteriorates, the image data is read from the nonvolatile memory M, and the same image is simply and easily rewritten on the image display unit 11 based on the read image data. it can. Thus, the same image can be retained for a long time.

Next, an example of displaying an image using the reversible image display medium TP will be described together with an image display device.

FIG. 8 shows the reversible image display medium TP shown in FIG.
The schematic configuration of an example of the image display device 200 in which are arranged (connected here) is shown.

The image display device 200 shown in FIG. 8 has a medium placement section 211 (here, an interface (I / F) section) on which a reversible image display medium TP can be placed (here, connected).
An image writing unit 212 that writes an image based on image data corresponding to an image to be displayed on the image display unit 11 of the medium TP, and a data write that writes and stores the image data in the nonvolatile memory M of the medium TP A writing unit 210 including a unit 213; a data reading unit 230 (here, a personal computer which is an example of a display data output device) capable of reading image data stored in the nonvolatile memory M;
0, an image rewriting unit (common to the image writing unit 212) for rewriting an image on the image display unit 11 based on the read image data;
F) section 214.

The reversible image display medium TP has an I / F unit 211
Is connected to the writing device 210 via the. Thereby, the second electrode 115 (common electrode) and the first electrode 115 of the image display section 11 are formed.
The electrodes 114 (individual electrodes) are connected to the image writing unit 212, and the non-volatile memory M stores the data writing units 213 and I
/ F section 214.

The data reading section 230 is connected to the writing device 210 via the I / F section 214.
As a result, the data reading unit 230 is
12 and the nonvolatile memory M.

The image writing section 212 includes an electrode selection circuit 117, a positive drive voltage generation circuit 118a, a negative drive voltage generation circuit 118b, and a display data control section 119, as shown in FIGS.

In the image display device 200, the writing (image display) of the image on the reversible image display medium TP by the writing device 210 writes the image data to be printed from the display data output device 230 (here, a personal computer). To the writing device 210
Individual electrode 1 of image display unit 11 corresponding to image data on the side
This is performed by controlling the application of voltage to.

That is, as described above, the individual electrodes 114
“a” is connected to the electrode selection circuit 117 through each lead 110 as shown in FIGS. Electrode selection circuit 11
7, a positive drive voltage generation circuit 118a, a negative drive voltage generation circuit 118b, and a display data control unit 119 are connected. A drive voltage is applied to each of the individual electrodes 114a independently from the electrode selection circuit 117.
The display data control unit 119 receives display data from the display data output device 230 (here, a personal computer), and controls the electrode selection circuit 117 based on the display data.

At this time, the writing device 210 writes image data in the nonvolatile memory M by the data writing section 213 at the same time.

The reversible image display medium TP in which the image is written in the image display section 11 and the image data is written in the nonvolatile memory M is stored in the nonvolatile memory M on the personal computer 230 side. The image data is read, and the image is rewritten on the image display unit 11 by the image rewriting unit (common to the image writing unit 212) of the writing device 210.

According to the image display apparatus 200 described above, not only an image is written in the image display section 11 based on image data corresponding to an image to be displayed, but also the image data is written and stored in the nonvolatile memory M. When the image displayed on the image display unit 11 is deteriorated (for example, the image disappears or is disturbed), the image data stored in the nonvolatile memory M is read out, and based on the read image data, it is easy and easy. The same image can be rewritten on the image display unit. Thus, the same image can be retained for a long time.

Here, the data reading section 230 (here, a personal computer) reads out the image data stored in the nonvolatile memory M, sends the image data to the writing device 210, and Although the rewriting (redisplay) of the image was performed on the image display unit 11, the data reading unit 230 is provided in the writing device 210, and the writing device 210 reads the image data from the non-volatile memory M and the image display unit. The image may be rewritten (redisplayed) to the memory 11.

In any case, in the image display device 200, the reversible image display medium TP in which the image is further written in the image display section 11 and the image data is written in the nonvolatile memory M is arranged in the medium arrangement of the writing device 210. Part 2
11 for detecting that rewriting of an image on the image display unit 11 of the medium TP is enabled.
0, an image is written to the image display unit 11 of the reversible image display medium TP arranged in the medium arrangement unit 211 of the writing device 210 based on the image data, and the medium TP
The writing device 210 is controlled to write the image data to the nonvolatile memory M, and the reversible image display medium TP in which the image is written to the image display unit 11 and the image data is written to the nonvolatile memory M is written. Device 21
0 that the image can be rewritten on the image display unit 11 by being disposed in the medium
Is detected, the data reading unit 230 reads the image data from the non-volatile memory M, and based on the read image data, causes the writing device 210 to rewrite the image to the image display unit 11. May be provided with a control unit CONT for controlling the writing device 210.

Also, instead of the detection device 220, a reversible image display medium TP in which an image is written in the image display unit 11 and image data is written in the nonvolatile memory M is arranged in the medium arrangement unit 211 of the writing device 210 ( For example, when a state in which the image display unit 11 of the medium TP is enabled to rewrite the image on the image display unit 11 for a predetermined time or more is provided, a detecting device (for example, a detecting device including a timer) for detecting this is provided. A reversible image display medium TP in which an image is written on the display unit 11 and image data is written on the nonvolatile memory M
Is detected by the detecting device that the state in which the image is rewritten to the image display unit 11 for a predetermined time or more is arranged (for example, connected) to the medium disposing unit 211 of the writing device 210. , Each time it is detected,
The data reading unit 230 and the writing device 210 are controlled so that the data reading unit 230 reads image data from the nonvolatile memory M, and rewrites an image to the image display unit 11 based on the read data. The control unit CONT may be configured to periodically rewrite an image (refresh the image).

In FIG. 8, the magnets shown in FIG. 4 are not shown.

FIG. 9 shows a reversible image display medium according to the present invention (here, a dry type reversible image display medium containing charged particles).
It is a figure showing the schematic structure of other examples.

A reversible image display medium TP ′ shown in FIG. 9 includes an image rewritable image display section 13 and the image display section 13.
And a non-volatile memory M ′ for storing image data corresponding to an image to be displayed.

FIG. 10 shows the reversible image display medium T shown in FIG.
FIG. 3 shows a schematic cross-sectional view of a part of the image display unit 13 at P ′.

The image display section 13 shown in FIG. 10 is rectangular in its entirety, and includes a first substrate 131, a second substrate 132, and a partition 133 between these two substrates.

The first substrate 131 and the partition 133 are integrally formed by heating and pressing transparent polyethylene terephthalate (PET). The first substrate 131 has an average thickness of the base portion of 25 μm. The partition 133 has a width of 30 μ.
m and a height h = 100 μm in a grid pattern at 1 mm intervals. The thickness of the entire image display unit is H = 150 μm
It is.

The first substrate 131 and the grid-shaped partition 133
(Developer accommodating cell) 136 surrounded by
L is adjusted so that the volume ratio of the developer DL to the volume of the concave portion 136 is about 30%. Note that the developer DL is the same as that used for the image display unit in FIGS.

The second substrate 132 is made of a 25 μm-thick carbon black-containing PET film. The second substrate 132 is brought into close contact with the first substrate 131 on which the photocurable adhesive 139a is thinly applied only on the top of the partition wall 133, and is irradiated with ultraviolet light. The photocurable adhesive 139a is thereby cured, and thus is adhered to the first substrate 131. Although not shown, the peripheral portions of the first and second substrates 131 and 132 are sealed by heat sealing.

The non-volatile memory M 'shown in FIG. 9 is a magnetic tape here, and is provided at the end of the reversible image display medium in the longitudinal direction (X direction in FIG. 9).

The data is not erased from the magnetic tape M 'even if power is not supplied, and the image data can be stored semi-permanently. Therefore, an image based on the image data can be transferred to the medium TP' if necessary. The image can be displayed again on the image display unit 13.

According to the reversible image display medium TP ′ shown in FIG. 9, an image is written in the image display section 13 based on the image data corresponding to the image to be displayed, and the image data is written and stored in the magnetic tape M ′. Can be kept. When the image displayed on the image display unit 13 deteriorates, the image data is read from the magnetic tape M ′, and the same image is simply and easily rewritten on the image display unit 13 based on the read image data. it can. Thus, the same image can be retained for a long time.

Next, an example of displaying an image using the reversible image display medium TP ′ will be described together with an image display device.

FIG. 11 shows the reversible image display medium T shown in FIG.
3 shows a schematic configuration of an example of an image display device 300 on which P ′ is arranged.

An image display device 300 shown in FIG. 11 has a medium placement unit 311 on which a reversible image display medium TP 'can be placed.
And an image writing unit 312 for writing an image based on image data corresponding to an image to be displayed on the image display unit 13 of the medium TP ′, and writing and storing the image data on the magnetic tape M ′ of the medium TP ′ Data writing unit 313
A data reading unit 230 (here, a personal computer which is an example of a display data output device) capable of reading image data stored on the magnetic tape M ′, and the data reading unit 23
0 includes an image rewriting unit (common to the image writing unit 312) for rewriting an image on the image display unit 13 based on the read image data.

FIG. 12 shows the image writing section 31 shown in FIG.
2 shows a schematic configuration diagram of a part of one example.

The image writing section 312 in FIG. 12 includes an ion flow type direct electrostatic latent image forming device CR2.
The device CR2 includes a corona ion generator c2 for generating corona ions, a writing electrode e2 for guiding the corona ions generated by the generator to, for example, the surface of the first substrate 111 of the display unit 13, and a positive (or negative) electrode. A write electrode control circuit f2 for applying a voltage to the write electrode e2 to guide corona ions to a pixel corresponding portion on the surface of the substrate 111 in accordance with an image to be displayed.

The corona ion generating section c2 is provided in the shield case c21.
A corona wire c22 is formed by stretching a gold-plated tungsten wire having a diameter of 20 μm, and a positive (or negative) voltage (for example, 4 kV to 10 kV) is applied to this wire from a power supply Pc2 to generate corona ions.

The write electrode e2 is provided on the portion of the shield case c21 facing the first substrate 131 of the display section 13, and is composed of an upper electrode e21 and a lower electrode e22. The ion stream can pass.

The electrode control circuit f2 includes a control power supply Pc21,
Including a bias power supply Pc22 and a control unit f21,
The control unit f21 applies an ion extraction voltage corresponding to the polarity of the ions to be derived toward the display unit 13 to the electrodes e21 and e21.
22 can be applied.

Here, when a positive voltage is applied to the upper electrode e21 and a negative voltage is applied to the lower electrode e21 under the instruction of the control unit f21, positive corona ions can be guided to the image display unit of the medium (FIG. 12). (A)). When a negative voltage is applied to the upper electrode e21 and a positive voltage is applied to the lower electrode e21, positive corona ions can be confined (FIG. 12B).

An electrode roller R1 is provided so as to face the writing electrode e2, and a bias voltage is applied to the electrode roller R1 from the power supply PW1, or the roller R1 is set to the ground potential. The roller R1 incorporates a magnetic pole roller R2 that is driven to rotate.

In forming an image on the display section 13, the developer DL contains white developing particles WP (insulating particles) and black developing particles BP (magnetic particles), and these are almost uniformly mixed before the image is displayed. (See FIG. 10).

The surface of the display section 13 in such a state is previously charged at a predetermined potential (about −500 in this case) with a charger such as a corona charger.
V) is uniformly charged. Note that the charging method and configuration are not limited as long as the surface of the display unit 13 can be charged in advance. While the display unit 13 thus pre-charged is relatively moved with respect to the device CR2, and the electrode roller R1 is rotated in the medium feeding direction and the magnetic pole roller R2 is rotated in the opposite direction, an image to be displayed is formed. Accordingly, the control unit f
Under the instruction of 21, for a predetermined pixel corresponding portion corresponding to an image to be displayed among a plurality of pixel corresponding portions on the surface of the first substrate 111, positive corona ions are derived as shown in FIG. The outflow of ions is prevented for the other pixels as shown in FIG. Here, the first substrate 1
The surface potential of the region charged with the positive corona ions on the surface of the surface 11 is about +500 V, and the surface potential of the uncharged region is about -500 V which is charged in advance. In this manner, the counter electrode roller R1 having the rotatable magnetic pole roller R2 therein is grounded, and the rotation of the magnetic pole promotes the movement of the contained developer DL, so that the white developing particles WP (insulating particles) And the black developing particles BP (magnetic particles) move toward the front substrate (image observation side substrate 131) / back substrate (substrate 132 opposite to the image observation side).

Thus, as shown in FIG. 13, the display section 13 has a region (about +500) charged with positive corona ions.
The area charged to V) is a white area, and the other area (area charged to about -500 V) is acted upon by a reverse electric field to form a black area, so that an image can be displayed.

After erasing the surface charge (electrostatic latent image) of the image display unit 13 on which an image has been formed, an image can be formed again by the image writing unit 312 again.

It is not always necessary to charge the surface of the display unit 13 in advance.

The discharge wire c2 in the device CR2
2 can be replaced by a solid discharge element.

The image display device 300 shown in FIG. 11 is further provided with a magnetic head HD shown in FIG.

In the image display device 300, the medium TP 'having the magnetic head HD and the magnetic tape M' is scanned relative to each other, so that the image is displayed on the magnetic tape M 'by the magnetic head HD in the writing device 310. Data can be written. Further, the image data recorded on the magnetic tape M ′ can be read by the data reading unit 230.

The writing (image display) of an image on the reversible image display medium TP ′ by the writing device 310 is performed by transmitting image data to be printed from the display data output device 230 (here, a personal computer) to the writing device 310. The writing device 310 converts the image data into data for each line corresponding to the image position, and outputs the data in accordance with the print position. The data conversion for each line corresponding to the image position of the image data may be performed on the display data output device side.

At this time, the writing device 210 simultaneously writes the image data onto the magnetic tape M ′ as well.
At 3 the data is written by the magnetic head HD.

The reversible image display medium TP ′ in which the image is written in the image display unit 13 and the image data is written in the nonvolatile memory M ′ is stored in the nonvolatile memory M ′ by the data reading unit 230. The written image data is read, and the image is rewritten on the image display unit 13 by the image rewriting unit (common to the image writing unit 312) of the writing device 310.

According to the image display apparatus 300 described above, not only an image is written in the image display section 13 based on image data corresponding to an image to be displayed, but also the image data is written and stored on the magnetic tape M '. When the image displayed on the image display unit 13 is degraded (for example, the image disappears or is disturbed), the image data stored on the magnetic tape M ′ is read out, and based on the read image data, it is easy and easy. The same image can be rewritten on the image display unit. Thus, the same image can be retained for a long time.

The operation of reading the image data from the magnetic tape M 'by the data reading section 230 and the operation of the image display section 1 by the writing device 310 based on the image data.
3 may be performed separately, or the data read operation and the image write operation may be performed continuously within one scan. Further, the magnetic head HD may be provided separately from the writing device 310.

The image writing unit 312 shown in FIG.
Includes an ion flow type electrostatic latent image forming apparatus, but is not limited thereto, and may include various electrostatic latent image forming apparatuses.

As an example of the embodiment of the present invention, the case of a dry type reversible image display medium containing charged particles has been described. The same applies to a reversible image display medium. These reversible image display media will be described below. <Image Display Portion of Electrophoretic Reversible Image Display Medium> FIG.
Shows a structural example of the image display unit 14 of the electrophoretic reversible image display medium.

The image display section 14 shown in FIG. 14 includes an electric field coloring layer 140 supported on a transparent support substrate 146. The developing layer 143 in which the charged coloring particles 141 are dispersed in the insulating liquid 142 is used as the electric field coloring layer 140.
4 and the insulating layer 145 are sealed. As the insulating liquid 142, high-purity petroleum (for example, Isopar (trade name) manufactured by Esso Corporation) is used, and an ionic surfactant and a dye are contained therein.
There is. The ionic surfactant is adsorbed on the pigmented organic coloring particles 141 and the particles are electrochemically stably charged. The charged colored particles 141 are liquid 142
Dispersed in it to show electrophoretic properties.

The display section 14 checks whether an electric field is applied or not.
When an electric field opposite to the predetermined electric field is applied, the color of the dye in the insulating liquid 142 is visible, but when the electrostatic latent image is written, the charged colored particles 141 move toward the transparent conductive layer 144. Move and see the pigment.

The display section 14 has the insulating liquid 1 in the display section.
An image can be displayed by forming an electrostatic field corresponding to the image to be displayed on the charged developing particles (here, charged colored particles) 141 dispersed in the sample.

Although the structural example has been described above, when the image display section of the electrophoretic reversible image display medium is used, the image display mediums TP and T shown in FIGS. 1 to 4 and FIGS.
At P ′, a developer 14 in which charged colored particles 141 are dispersed in an insulating liquid 142 in each cell in place of the developer DL
Electrophoretic image display units 11 and 13 enclosing 3 are used.

However, the developer 143 is sealed in the first and second
After bonding the substrates to each other while leaving the liquid inlets, air bubbles are put into each cell from the inlets, and then the inlets are heat-sealed.

The details of the developer in each cell are as follows.

A black dye (BAS) was added to 100 ml of isoparaffinic hydrocarbon (Isopa G manufactured by Exxon Chemical Co., Ltd.).
1 g of Sudan Black X60 (manufactured by Company F) was added and sufficiently dissolved and mixed to prepare a colored liquid.

The titanium dioxide particles (manufactured by Ishihara Sangyo Co., Ltd.)
CR-50) and 0.5 wt% of sulfol B
a-30N (barium sulfonate manufactured by Matsumura Petroleum Institute Co., Ltd.) was mixed with 70 g of an IP solvent 1620 solution, and the mixture was mixed with a sand grinder (IGARASHI KIKA).
I SEIZO CO. , Ltd. Using 1 mm diameter glass beads (150 cc) as a medium, a cooling water temperature of 20 ° C., and a disk rotation speed of 2,000 rpm in a に て GL vessel with a water jacket.
For 15 hours for wet grinding.

To 100 parts by weight of the concentrated liquid developer, IP
Solvent 1620 was diluted by adding 900 parts by weight,
T. K. Auto homomixer M type (Special Kika Kogyo Co., Ltd.)
Was subjected to a dispersion treatment at 10,000 rpm for 5 minutes to obtain a developer, which was used as the developer 143. <Image display section of twisted ball type reversible image display medium>
FIG. 15 shows an example of the structure of the image display section 15 of the twisting ball type reversible image display medium.

The image display section 15 shown in FIG. 15 has an electric field coloring layer 150 supported on a transparent support substrate 156. The electric field coloring layer 150 is formed by surrounding a single-sided colored sphere 151 having one side colored 151a with an insulating liquid 152 so as to float therein, embedding the liquid in the insulating holding medium 153, and placing a transparent conductive layer 154 on one side of the medium 153. And an insulating layer 155 formed on the opposite side.

The single-sided colored sphere 151 is produced by, for example, uniformly arranging white spheres of glass mainly composed of TiO ₂ on a suitable table and depositing chromium or the like from the upper surface. The size may be in the range of 30 μm to 100 μm, but 10 μm
If the following is set, the resolution will be higher.

The single-sided colored sphere 151 is dispersed in an insulating holding medium 153 such as an elastomer, and the medium 153 is immersed in a solution of an ionic surfactant in an organic solvent such as toluene. Swell, thereby causing the insulating liquid 152 to collect around the single-sided colored sphere 151. Thus, the single-sided colored sphere 151 is made of the insulating liquid layer 15.
2, the liquid is embedded in the insulating holding medium 153 together with the liquid in a rotatable state.

Since the one-sided colored sphere 151 has different properties on one hemisphere and the other hemisphere, the amounts of adsorbed ions are different on both surfaces. Therefore, when an electric field is applied to the display unit 15, the direction of the surface of the single-sided colored particles 151 changes depending on the direction of the electric field. Accordingly, an image is displayed by seeing the colored surface of the single-sided colored sphere 151 or an uncolored surface.

Although the structural example has been described above, here, when the image display section of the twisting ball type reversible image display medium is used, the one manufactured in the following steps is used.

The image display portion of the twisting ball type reversible image display medium is a spherical body, one hemispherical surface is a white surface coated with poly (trifluoroethyl methacrylate), and the other hemispherical surface is blue. Was prepared using a two-color sphere having a particle size of 17 μm. The resin for forming the sphere used here is a polyester resin, the white pigment is titanium dioxide, and the blue pigment is copper phthalocyanine. First step: Preparation of white monochromatic sphere 50 g of sulfonated polyester resin, copoly (propylene-ethylene-terephthalate) copoly (propylene-ethylene-5-sulfoisophthalate)
Dispersed at 250C in 250 g of water. The resulting polyester emulsion was then cooled to room temperature, about 25 ° C., to which one part of a titanium oxide in water dispersion (50% solids) available from Sun Chemicals.
0 g was added. While slowly adding a 1% by weight aqueous magnesium chloride solution (50 ml) to the resulting mixture,
The mixture was homogenized and mixed at about 1000 rpm. Thereafter, the resulting mixture was transferred to a 1 liter kettle. The resulting mixture was stirred overnight (about 18 hours) at 200 rpm and heated to 55 ° C. Thus, when measured using a Coulter counter, 50 g of a white monochromatic sphere having a diameter of 17 μm and a geometric size distribution of 1.13 was obtained. Second step: White sphere 1 (prepared as described above in the first step) in 100 g of surface polymerization water of the white monochromatic sphere
0g to 0.25g cerium ammonium nitrate and 1m
of nitric acid 1N solution was added. The resulting mixture was stirred for 3 hours, after which the white spheres were filtered and the spheres were resuspended in 100 ml of water. Then, 0.25 g of potassium persulfate, 0.25 g of sodium disulfite and 0.
5 g of trifluoroethyl acrylate were added. The resulting mixture was stirred at room temperature (about 25 ° C.) for 3 hours, and the surface-grafted monochromatic spheres thus obtained were filtered, washed with water and resuspended in about 1 liter of water. Third step: Thermal evaporation coating of spheres on glass with copper phthalocyanine Using the obtained monochromatic charged white sphere suspension, on a glass slide substrate by Langmuir-Blodgett technology,
A coating layer having a thickness of less than about 500 nanometers (here, about 400 nanometers) was formed. About 18
Air dried for hours. Approximately 0.00
The copper phthalocyanine pigment was vacuum-deposited in a vacuum atmosphere of 01 mmHg to about 0.1 mmHg.

Thus, white / blue bicolor spheres were obtained. In this two-color sphere, the proportions of the blue and white portions were almost equal. The 0.3 μm thick phthalocyanine layer has little effect on the diameter of the sphere, and the diameter of the resulting dichroic sphere remains at about 17 μm. In this image display section, the white side of the sphere treated with fluoroacrylate and the side coated with blue with copper phthalocyanine are charged with different charging polarities. Fourth Step: Production of Image Display Unit 50 g of the two-color sphere prepared by the above steps was mixed with 50 g of SYLGARD (registered trademark) 185 silicone elastomer kit available from Dow Corning.・ P. Gardner Company (P. Gardner C
ompamy), the gap is about 20 μm
The mixture is spread on a glass plate surface using a weighing bar such as an 8-pass wet film applicator of ~ 500 µm to form a sheet, and the sheet is heated from about 80 ° C to about 100 ° C.
The SYLGARD elastomer sheet was crosslinked at a temperature of about 3 hours to about 24 hours. -The sheet was then plasticized by immersing the sheet in a container containing about 50 ml to about 500 ml of a suitable oil such as Isopar or silicone oil to form an oil-filled hole in the sheet. -The sheet was further removed from the oil container and sealed between mylar (MYLAR) substrates about 15 μm thick. Note that a conductive layer (for example, a conductive layer formed by an Al deposition process) was previously formed on one of the mylar substrates (backside substrate).

Thus, an image display section of a twist ball type reversible image display medium was obtained. <Image Display Unit of Magnetically Driven Reversible Image Display Medium> FIG.
Reference numeral 6 denotes an image display unit 16 of a magnetically driven reversible image display medium.
2 shows an example of the structure.

The image display section 16 shown in FIG. 16 comprises light-absorbing black magnetic particles 164, a dispersion medium, a thickener, if desired,
A multi-cell structure sheet 160 formed by partitioning a plastic dispersion liquid 165 containing a colorant as a component into a small chamber 163 between at least two transparent substrates 161 and 162 on the image observation side.
Is an image display unit enclosed in each of the small chambers 163.

Instead of the image display section having such a structure, a coating layer of a large number of microcapsules containing the same light-absorbing black magnetic particles 164 and plastic dispersion liquid 165 was formed on one surface of the transparent substrate. An image display unit may be used.

As shown in FIG. 16, such an image display section is provided for each pixel in accordance with an image to be formed by using a magnetic head H2 from the substrate surface of the front side (image observation side) substrate 161. , The magnetic particles 164 attracted by the magnetic force migrate, and an image is displayed with a difference in color contrast between the plastic dispersion liquid 165 and the magnetic particles 164.

As the magnetic head H2 for writing, for example, the magnetic particles 164 in the small chamber 163 of the display unit 16 (or the microcapsule of the image display unit of the microcapsule type medium) are attracted to the front substrate 161 by magnetic force. An electromagnet 171 group provided on the front substrate 161 side to obtain
One having a DC power supply 172 for supplying a DC current to each electromagnet 171 can be used.

As a coloring material of the plastic dispersion liquid 165, a white pigment or other pigments or dyes can be used. Such a colorant can be added, for example, in an amount of 10% or less, preferably 3% or less, to the plastic dispersion liquid to increase the contrast between the plastic dispersion liquid 165 and the magnetic particles 164, thereby sharpening the image display. Can be.

The light-absorbing black magnetic particles 164 are preferably formed by kneading a magnetic substance such as magnetite, ferrite, etc., carbon black as a coloring agent, and a binder resin, and pulverizing the mixture to a particle size of about 5 μm to 100 μm. .

The light-absorbing black magnetic particles 164 are preferably contained in the plastic dispersion liquid 165 in an amount of 5 to 30% by weight, more preferably 10 to 20% by weight.

As the dispersion medium constituting the plastic dispersion liquid 165, a paraffin-based solvent represented by Isopar (isoparaffin solvent manufactured by Esso Chemical Co., Ltd.), silicone oil, and the like are preferably used.

[0167]

As described above, according to the present invention, a rewritable reversible image display medium which enables a once displayed image to be simply and easily rewritten, thereby maintaining the same image for a long period of time. Can be provided.

Further, according to the present invention, there is provided an image display method for displaying an image on a rewritable reversible image display medium, wherein an image once displayed on the medium can be simply and easily rewritten on the medium. An image display method capable of displaying the same image for a long time can be provided.

Further, according to the present invention, there is provided an image display apparatus for displaying an image on a rewritable reversible image display medium, wherein the image once displayed on the medium can be simply and easily rewritten on the medium. Can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an example of a reversible image display medium according to the present invention (here, a dry type reversible image display medium containing charged particles).

FIG. 2 is a sectional view showing a schematic configuration of a part of an image display unit in the reversible image display medium shown in FIG.

3 is a cross-sectional view of an image display unit of the reversible image display medium shown in FIG. 1 before image display and a schematic configuration diagram of an image writing unit.

4 is a cross-sectional view of an image display state of an image display unit in the reversible image display medium shown in FIG. 1 and a schematic configuration diagram of an image writing unit.

FIG. 5 is a perspective view of a first substrate and grid-like partition walls formed on the first substrate in the image display unit shown in FIGS. 2 to 4;

FIG. 6 is a plan view of a first substrate and individual electrodes formed on the first substrate in the image display unit shown in FIGS. 2 to 4;

FIG. 7 is a diagram showing an example of image display on the image display unit shown in FIGS. 2 to 4;

8 is a diagram showing a schematic configuration of an example of an image display device in which the reversible image display medium shown in FIG. 1 is arranged (connected here).

FIG. 9 is a diagram showing a schematic configuration of another example of a reversible image display medium (here, a dry type reversible image display medium containing a charged particle) according to the present invention.

10 is a cross-sectional view showing a schematic configuration of a part of an image display unit in the reversible image display medium shown in FIG.

11 is a diagram showing a schematic configuration of an example of an image display device on which the reversible image display medium shown in FIG. 9 is arranged.

12 is a diagram illustrating a schematic configuration of a part (an ion flow type direct electrostatic latent image forming apparatus) of an example of the image writing unit illustrated in FIG. 11, and FIG. 12A illustrates an ion flow state; (B) is a diagram showing an ion flow stopped state.

FIG. 13 is a diagram for explaining how an image is displayed on an image display unit by the device shown in FIG. 12;

FIG. 14 is a diagram illustrating a structural example of an image display unit of an electrophoretic image display medium.

FIG. 15 is a diagram illustrating a structural example of an image display unit of a twisted ball type image display medium.

FIG. 16 is a diagram illustrating a structural example of an image display unit of a magnetically driven image display medium.

[Explanation of symbols]

TP, TP 'Dry type reversible image display medium containing charged particles 11 Image display portion 111, 112 Substrate 113 Partition wall 114 First electrode 114a Individual electrode 115 Second electrode 116 Developer containing cell 117 electrode of reversible image display medium TP Selection circuit 118a Positive drive voltage generation circuit 118b Negative drive voltage generation circuit 119 Display data control section 119a Photocurable adhesive 119b Epoxy adhesive M, M 'Non-volatile memory WP White developing particles BP Black developing particles DL Developer α Partition Wall width h Partition wall height pt Partition wall interval Bk Black display portion W White display portion R1 Electrode roller R2 Magnetic pole roller MG Magnet plate 200 Image display device 210 Writing device 211 Medium placement unit (interface (I / F) unit) 212 Image Writing unit (image rewriting unit) 213 data Writing unit 220 Detecting device 230 Data reading unit 214 Interface (I / F) unit CONT control unit 131, 132 Substrate 133 Partition wall 136 Developer storage cell 139a Photocurable adhesive 300 Image display device 310 Writing device 311 Medium placement unit 312 Image writing unit (image rewriting unit) 313 Data writing unit CR2 Ion flow type direct electrostatic latent image forming device c2 Corona ion generating unit e2 Writing electrode f2 Writing electrode control circuit c21 Shield case c22 Corona wire Pc2 Power supply e21 Upper electrode e22 Lower electrode Pc21 Control power supply Pc22 Bias power supply f21 Control unit HD magnetic head 14 Image display unit of electrophoretic reversible image display medium 140 Electric field coloring layer 141 Charged colored particles 142 Insulating liquid 143 Developer 144 Transparent conductive layer 145 Insulating layer 146 Transparent support substrate 15 Image display section of twisted ball type reversible image display medium 150 Electric field coloring layer 151 Single-sided colored sphere 151a Colored 152 Insulating liquid 153 Insulating holding medium 154 Transparent conductive layer 155 Insulating layer 156 Transparent support substrate 16 Image display part of magnetically driven reversible image display medium 161, 162 Substrate 163 Small chamber 164 Light absorbing black magnetic particles 165 Plastic dispersion liquid H2 Magnetic head 171 Electromagnet 172 DC power supply

Claims (11)

[Claims] 1. A reversibility comprising: an image display unit capable of rewriting an image; and a nonvolatile memory for storing image data corresponding to an image to be displayed on the image display unit. Image display medium. 2. The image display section comprises: two substrates facing each other at a predetermined interval; and one or more developers formed between the two substrates and surrounded by a partition wall. A storage cell; and a dry developer contained in each of the cells, wherein the dry developer has at least two kinds of triboelectric charging properties having different charging polarities and different optical reflection densities. The reversible image display medium according to claim 1, comprising dry-developed particles having: 3. The reversible image display medium according to claim 2, wherein at least one of the two types of dry developing particles contained in the dry developer is a magnetic developing particle. 4. An image display method for displaying an image on a reversible image display medium according to claim 1, wherein the image is written in the image display unit based on image data corresponding to an image to be displayed. An image display method comprising a writing step of writing and storing the image data in the nonvolatile memory. 5. An image display method for displaying an image on a reversible image display medium according to claim 1, wherein the image data stored in the nonvolatile memory is read, and based on the read image data. An image display method, comprising a rewriting step of rewriting an image on the image display unit. 6. An image display method for displaying an image on a reversible image display medium according to claim 1, 2 or 3, comprising a writing step according to claim 4 and a rewriting step according to claim 5. An image display method characterized by the following. 7. The image display method according to claim 5, wherein the rewriting step is periodically repeated. 8. An image display device for displaying an image on a reversible image display medium according to claim 1, 2 or 3, wherein an image is written in the image display unit based on image data corresponding to an image to be displayed. An image display device comprising: a writing unit; and a data writing unit that writes and stores the image data in the nonvolatile memory. 9. An image display device for displaying an image on a reversible image display medium according to claim 1, 2 or 3, wherein said data read unit reads image data stored in said nonvolatile memory. An image rewriting unit for rewriting an image in the image display unit based on the image data read by the image display unit. 10. An image display device for displaying an image on the reversible image display medium according to claim 1, 2, or 3.
An image display device comprising: the image writing unit and the data writing unit according to claim 9; and the data reading unit and the image rewriting unit according to claim 9. 11. When the reversible image display medium is mounted, the data reading unit periodically reads the image data stored in the nonvolatile memory, and the image rewriting unit reads the image data. The image display device according to claim 9, further comprising a periodic rewrite control unit that rewrites an image on the image display unit based on the image data read by the data read unit.