JP4925003B2 - Display medium capable of manual writing, display device, and display method - Google Patents

Description

  The present invention relates to a rewritable display medium, display device, and display method using electrophoresis, magnetophoresis, etc., and in particular, displays a main image by applying a magnetic field to the recording layer, and also records the recording The present invention relates to a display medium, a display device, and a display method capable of performing desired manual writing without affecting a main image by applying a magnetic field to a layer with a magnetic pen at a desired position.

  Conventionally, an electrophoretic display device that performs uniform and stable display operation by applying a microcapsule enclosing a dispersion medium and electrophoretic particles as display means using electrophoresis and magnetophoresis is disclosed in Japanese Patent Application Laid-Open No. 64-86116. Japanese Laid-Open Patent Publication No. 4-175196 discloses a color display means using magnetophoresis using a magnetic panel and a magnetic pen to obtain a clear image by increasing the recording speed using a low-boiling solvent as a dispersion medium. Japanese Patent Application Laid-Open No. 8-54841 and Japanese Patent Application Laid-Open No. 8-297470 disclose a system in which a magnetic particle is dispersed in wax and high-quality digital image display can be performed by a combination of heat application by a thermal head and a permanent magnet. In 2004-4412, a colored magnetic material and inorganic pigment particles are encapsulated in a capsule together with a hot-melt organic compound, and heat and magnetism are marked. Which displays an image by is presented in JP 2003-322882.

  However, the conventional image display means displays an image having a certain pattern, and recently, the main image once displayed is rewritten using a desired input pen, or one of the displayed main images. It does not have a function as a display means capable of manual writing such as deleting a part.

In view of this, display means capable of manual writing described above are presented in Japanese Patent Application Laid-Open Nos. 2000-47266 and 2005-208310.
JP-A 64-86116 JP-A-4-175196 Japanese Patent Laid-Open No. 8-54841 JP-A-8-297470 JP 2004-4412 A JP 2003-322882 A JP 2000-47266 A JP 2005-208310 A

  However, the display means that can be manually written as disclosed in Japanese Patent Application Laid-Open No. 2000-47266 is displayed by moving an electrophore dispersed in a dispersion medium enclosed in a microcapsule to the input pen side with an input pen. Rewriting is performed by switching between display and non-display in the image, and there is a disadvantage in that a display that is not rewritten in the main image located in the vicinity of the rewriting unit is rewritten together.

  Moreover, the display means capable of hand writing presented in Japanese Patent Application Laid-Open No. 2005-208310 exhibits a reliable rewriting function by mixing two types of images that can be rewritten by different signals on one display screen. However, the mechanism and control are complicated and the equipment is also complicated, such as requiring two electrophoretic display means such as electrophoresis and magnetophoresis and means for controlling these electrophoretic display means. There is a problem in terms of economy because of the large scale, and it is not particularly suitable for a simple application for the purpose of secondary rewriting such as partial writing or partial deletion of the main image.

  Therefore, the present invention can display a clear main image on the basis of a digital signal, and can manually write or rewrite the entire display on the main image as desired. The configuration is not complicated and is inexpensive. The present invention provides a display medium, a display device, and a display method that can be manually written with various facilities.

The rewritable display medium according to the present invention made to solve the above problems encloses a dispersion medium comprising colored magnetic particles, white nonmagnetic particles, and a heat-meltable organic compound having a melting point of 35 ° C. or higher and 120 ° C. or lower. A support made of a non-magnetic material, and a primary microcapsule and a secondary microcapsule encapsulating a dispersion medium composed of colored magnetic particles, white non-magnetic particles, and a high-boiling liquid having a high-viscosity boiling point of 240 to 300 ° C. at room temperature It has a recording layer arranged on the body.

  A main image is displayed by selectively moving the colored magnetic particles by heating the dispersion medium in the main capsule to a temperature higher than the melting point in a state where a magnetic field is applied to a desired position with respect to the recording layer, At a temperature at which the dispersion medium in the main capsule does not melt, a magnetic field is applied to the recording layer with a magnetic pen at a desired position to move the colored magnetic particles in the subcapsule, thereby easily performing manual writing on the main image. be able to.

  In particular, in the rewritable display medium of the present invention, the melting point of the dispersion medium enclosed in the main capsule is 35 ° C. or more and 120 ° C. or less, which is convenient and energy-saving.

  In the present invention, the display medium, a magnetic field applying means for applying a magnetic field to the display medium, a heat applying means for applying heat to the display medium, and a subcapsule forming the display medium are provided. A magnetic pen for applying a magnetic field to the encapsulated colored magnetic particles, and heating the dispersion medium in the main capsule to a temperature higher than the melting point by the magnetic field applying means and the heat applying means. A main image is displayed by selectively moving, and a magnetic field is applied to a desired position by a magnetic pen on the recording layer at a temperature at which the dispersion medium in the main capsule does not melt, so that the colored magnetic particles in the subcapsule are An apparatus for performing hand writing by moving the object is provided.

  In particular, the magnetic field applying means is preferably a magnetic platen roll, and the heat applying means is preferably a thermal head.

Furthermore, in the present invention, main microcapsules encapsulating a dispersion medium composed of a colored magnetic material, white nonmagnetic particles, and a heat-fusible organic compound having a melting point of 35 ° C. or higher and 120 ° C. or lower ; colored magnetic particles; A rewritable recording medium having a recording layer in which particles and a secondary microcapsule enclosing a dispersion medium composed of a high-boiling liquid having a high-viscosity boiling point of 240 ° C. to 300 ° C. at room temperature are arranged on a support made of a nonmagnetic material By using a display medium and selectively moving the colored magnetic particles by heating to a temperature higher than the melting point of the dispersion medium in the main capsule with a magnetic field applied to the recording layer at a desired position. Main image display based on the main capsule by displaying an image and applying a magnetic field to the recording layer at a desired position with a magnetic pen at a temperature at which the dispersion medium in the main capsule does not melt Effect without giving a move the colored magnetic particles in the sub-capsule to provide a rewritable image display method that enables hand writing to the main image. This image display method includes initialization for erasing all displayed images by heating the entire surface of the recording medium to a temperature equal to or higher than the melting point of the dispersion medium sealed in the main capsule.

  According to the present invention, a dispersion medium made of a heat-fusible organic compound enclosed in a main microcapsule that forms a recording layer is selectively melted, and colored magnetic particles dispersed in the dispersion medium are subjected to a predetermined magnetic field. By applying and selectively moving, high-resolution main image display can be performed, and colored magnetic particles in the subcapsule can be magnetically applied with a magnetic pen to affect the main image display. The desired manual writing can be performed.

  It should be noted that although the resolution of the manual writing is inferior to that of the thermal writing signal portion, the main image is based on a digital signal and the manual writing is at the level of an auxiliary memo, so it can be said that the quality is sufficient for the purpose of use.

  In addition, according to the present invention, it is possible to easily display an image by combining heating at a relatively low temperature to melt the heat-fusible organic compound in both initialization and main image display and magnetic application. Therefore, a clear image display can be performed with very little energy consumption.

  Furthermore, according to the present invention, the colored magnetic particles in the main microcapsule are in a fixed state except during recording and erasing in which the colored magnetic particles are dispersed in a dispersion medium made of a heat-fusible organic compound that exhibits a solid state at room temperature. Therefore, even if magnetism is applied from the outside after information recording, the colored magnetic particles do not move, and an extremely stable main image can be obtained.

  Furthermore, in the present invention, a main image is formed by moving colored magnetic particles dispersed in a dispersion medium made of a heat-fusible organic compound in which a desired portion is melted by a thermal head (heating means) by applying a magnetic force. As a result, a fine image can be formed.

  In addition, since the recording layer constituting the display medium of the present invention can be formed by applying a coating liquid containing microcapsules on a support, it can be produced by a very simple manufacturing process, And it can also be manufactured at a very low cost.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following examples.

  FIG. 1 is an enlarged schematic diagram showing an example of an embodiment of a rewritable display medium according to the present invention. In the display medium 1, a recording layer 3 and a protective layer 4 are laminated on a support 2. It has a configuration. The recording layer 3 has a configuration in which two types of microcapsules consisting of main microcapsules 5 and sub-microcapsules 6 are filled and arranged. In the main microcapsules 5, colored magnetic particles 7 and white nonmagnetic particles 9 are present at room temperature. It is encapsulated in a dispersed state in a dispersion medium 8 made of a heat-fusible organic compound exhibiting a solid phase state. In the sub-microcapsule 6, colored magnetic particles 10 and white non-magnetic particles 11 have a high boiling point and high viscosity at room temperature. It is enclosed with the precipitation inhibitor 12 in a state of being dispersed in a dispersion medium 13 made of a solvent.

  More specifically, the support 2 is made of non-magnetic materials such as synthetic resins such as polyvinyl chloride, polyester, polycarbonate, polymethyl methacrylate, polystyrene, and polyethylene terephthalate, natural resins, paper, synthetic paper, metals, ceramics, and the like. Conventionally known shapes such as a card shape, sheet shape, film shape, etc., which are used alone or in combination, can be selected and used according to the application, and for example, strength and rigidity required according to the application. In addition, conventionally known physical properties such as concealability and light impermeability may be added.

  The recording layer 3 has a configuration in which main microcapsules 5 and sub-microcubes 6 are filled and arranged. In the display medium 1 shown in the present embodiment, the main microcapsules 5 and the sub-microcubes 6 are filled and arranged on the support 2 in a planar shape, but in consideration of the sharpness and resolution of the display image. It is also possible to have a laminated structure, and by forming the main microcapsule 5 and the submicrocube cell 6 finely, the resolution of the image displayed on the display medium 1 and the display device 14 finally obtained Can also be improved.

  The material of the colored magnetic particles 7 enclosed in the main microcapsule 5 is, for example, stainless steel such as iron, nickel, iron / nickel / base metal, iron / nickel / chromium alloy, cobalt, cobalt / aluminum alloy, samarium / cobalt. Those having excellent magnetism, such as alloys, may be used, and it is preferable to use those particles that are made into uniform fine particles using a ball mill or the like, and those having a particle size of about 0.1 to 5 μm. It is suitable in terms of ease of movement by applying magnetism, which will be described later, and contrast of displayed images. However, any shape that does not hinder movement by applying magnetism, such as a spherical shape and a needle shape, are known in the art. Shaped ones can be used. Any color can be selected. For example, black may be selected on the assumption that the contrast of the main image to be displayed is emphasized.

  Further, as the white nonmagnetic particles 9 enclosed in the main microcapsules 5, fine particles such as titanium oxide (anatase type, rutile type), zinc oxide, zinc sulfide and the like are used.

  The dispersion medium 8 made of a heat-fusible organic compound that disperses the colored magnetic particles 7 shows a solid state at room temperature (about 10 to 30 ° C.) and a fluid state at a temperature higher than room temperature. For example, natural or synthetic waxes such as paraffin wax and carnauba wax, natural or synthetic resins, carboxylic acid esters, etc. can be used singly or in combination, and can be used appropriately, particularly from a solid state to a fluid state. It is preferable that the change is steep according to the temperature change.

  The main microcapsules 5 enclosing the white magnetic particles 7 and the dispersion medium 8 are, for example, acrylic resin, methacrylic resin, polystyrene resin, polyester resin, polyurethane resin, polyurea resin, polyamide resin, epoxy resin, amino resin. A phase separation method in which a conventionally known material such as gelatin or alginic acid is used alone or a mixture of a plurality of materials, for example, a concentrated phase of a polymer is separated around the core substance dispersed in a polymer solution, Monomer or polymerization from either the liquid-cured coating method in which a polymer curing agent is allowed to act around the core material in the polymer solution to cure the polymer, the inner phase of the emulsion in which the core material is dispersed, or the outer phase. In-situ polymerization method for supplying a catalyst and covering the surface of the core material with a polymer, the core material Microencapsulation techniques such as interfacial polymerization that supplies monomers from both the inner and outer phases of the dispersed emulsion are used, especially phase separation methods using cross-linked gelatin, urea formalin, melamine formalin resin, etc. This method is preferable because it can produce microcapsules having a uniform particle diameter and uniform dispersion in which the mobility of the white magnetic particles 7 is not hindered, but is limited to these forming methods. Is not to be done.

  Further, the other sub-microcapsule 6 filled and arranged on the support 2 together with the main microcapsule 5 is for enabling manual writing display with a magnetic pen, and includes colored magnetic particles 10 and white non-magnetic particles. 11. A dispersion medium 13 composed of a high-boiling solvent having a high viscosity at room temperature and a suspending agent 12 are encapsulated.

  The colored magnetic particles 10 are formed to have a core material similar to the colored magnetic particles 7 enclosed in the main microcapsule 5 and a similar particle size, and exhibit good behavior with respect to magnetism. Further, it may be encapsulated with an adhesive and a colorant to give a special color tone. The color attached to the colored magnetic particles 10 is preferably a color different from that used for the main microcapsule 5 such as red, and the two can be clearly distinguished, but is not particularly limited. What is necessary is just to select suitably according to the intended use etc. including the enclosure of the microcapsule 5. FIG.

  On the other hand, the dispersion medium 13 encapsulated in the sub-microcapsule 6 is made of a high-viscosity high-boiling solvent, for example, one having a boiling point of 240 ° C. to 300 ° C. and a viscosity of about 2 to 15 cp, specifically, dodecyl. Examples thereof include benzene, diphenyl ether, butyl phthalate, benzyl benzoate, phenyl phosphate, and cresyl phosphate.

  Further, as the white nonmagnetic particles 11 enclosed in the sub-microcapsules 6, fine particles such as titanium oxide (anatase type, rutile type), zinc oxide, zinc sulfide and the like are used. As the precipitation inhibitor 12 enclosed in the sub-microcapsule 6, silica, silicate, fine powder alumina, kaolin, clay, bentonite, fine calcium carbonate, fine barium sulfate, etc. are applied, and the addition amount is 0 of the dispersion medium 13. 2 to 5% by weight is preferred.

  The sub-microcapsule 6 is also formed by the same forming method using the same material as the main microcapsule 5, and the formed main microcapsule 5 and sub-microcapsule 6 are, for example, an aqueous binder, an emulsion binder, or the like. The recording layer 3 is formed by dispersing it in a predetermined binder and coating it on the support 2. Specifically, by various methods such as a conventionally known printing method, a coating method such as a roll coating method and a bead coating method, and an ink jet method in which the ink mixed with the above-described microcapsules is sprayed on the support holiday 2. It can be prepared and can be appropriately selected according to the intended use and production amount of the display medium 1.

  In the drawing, reference numeral 4 denotes a protective layer 4 disposed on the upper surface of the recording layer 3, which serves to hold the recording layer 3 formed on the support 2, and is disposed on the recording layer 3. The microcapsule having light transmissivity so that the colored magnetic particles 7 inside the main microcapsule 5 can be colored and the colored magnetic particles 10 inside the auxiliary microcapsule 6 for handwritten display can be visually recognized from the outside; It is necessary to select a film thickness that is appropriate for maintaining heat resistance and mechanical strength of the display surface to withstand repeated heat application by heating means such as a thermal head 18 described later. For example, epoxy resin, polytetrafluoroethylene, polyvinyl chloride, polyester, polycarbonate, polymethyl methacrylate, polystyrene, polyethylene terephthalate, Polyvinyl alcohol, formed from gelatin of the sheet material or the like.

  FIG. 2 schematically shows a preferred embodiment of a display device 14 that performs image formation using the display medium 1 shown in FIG. 1 and initialization as a preparation stage thereof. A magnetic sheet 15 and a heat plate 16 are arranged along the recording layer 3 of the display medium 1.

  The magnetic sheet 15 has a function of applying a magnetic field to the colored magnetic particles 7 enclosed in the main microcapsules 5 forming the recording layer 3, and the heat plate 16 is a main microcapsule 5 forming the recording layer 3. Has a function of heating the dispersion medium 8 enclosed in the container. In the present embodiment, the magnetic sheet 15 and the heat plate 16 are arranged on the protective layer 4 side of the recording layer 3, but one or both of the magnetic sheet 15 and the heat plate 16 may be arranged on the protective layer 4 side. Good.

  When the display device 14 is used, first, the dispersion medium 8 enclosed in the main microcapsules 5 forming the recording layer 3 is heated and melted by the heat plate 16 and the main microcapsules 5 are used by using the magnetic sheet 15. The colored magnetic particles 7 and the colored magnetic material 9 enclosed in the sub-microcapsule 6 are arranged on the protective layer 4 side, that is, the display surface side, so that the main microcapsule 5 is black and the sub-microcapsule 6 is black. The initial state is displayed in red. At this time, the support 2 side of the main microcapsule 5 and the sub-microcapsule 6 is white. When the support 2 is formed of a transparent body, the whole is white, and when the support 2 is worn, it is colored. Displayed in color. Note that the apparatus used for this initialization may be a full surface heating apparatus different from that used for displaying the main image.

  In particular, as a display device 14 suitable for displaying a digital image as a main image, a thermal head 18 is suitable as a heating unit as shown in FIG. 3, and a magnetic field applying unit used in combination with this is a magnetic unit. A platen roll 17 is preferred. That is, the positional relationship is preferably such that the display material passes between the thermal head 18 and the magnetic platen robot 17. That is, the thermal recording apparatus including the opposed magnetic platen roll 17 and the thermal head 18 is used to heat the dispersion medium 8 made of a heat-fusible organic compound in the main microcapsule 5 to a temperature higher than its melting point based on the digital signal. The dispersion medium 8 is melted.

  Then, the magnetic platen roll 17 is arranged on the support 2 side, that is, the side opposite to the display screen having the protective layer 4 and a magnetic field is applied to cause all the colored magnetic particles 7 in the main microcapsule 5 to undergo magnetophoresis. To the support leave 2 side. At the same time, all the colored magnetic particles 10 in the sub-microcapsule 6 also move to the support 2 side by passing through the platen roll 17, so that the colored portion visually recognized from the display surface side in the micro cab cell 5. The colored magnetic particles 7 that have not moved are brought into a desired digital black display.

  When contact writing is performed from the protective layer 4 side with a magnetic pen (not shown) at an environmental temperature (for example, room temperature) at which the dispersion medium 8 does not melt in the recording layer 3 having the main image composed of the black image, the portion is colored red. Since the dispersion medium 8 has a solid phase in the main microcapsule 5, the colored magnetic particles 7 do not move by magnetism, so the main image remains unchanged.

  In general, in order to display a colored image of a small area on a white area having a large area, which is a large number of information patterns, with a minimum amount of heat energy, it is desirable that the portion to which heat is applied is printed in black. In order to make this possible with the display medium 1 according to the present invention, the recording layer 3 is formed by using the transparent support 2 and the image of the main microcapsule 5 in a state where the magnetic layer is applied from the protective layer 4 side is supported. It will be visually recognized from the body 2 side. That is, in this case, the display surface is on the support 2 side.

  In this case, the colored magnetic particles 10 enclosed in the sub-microcapsules 6 are also moved to the support 2 side by the application of magnetism to be colored on the entire surface, so that the protective layer is not heated again as a process after the print display. The colored magnetic particles 10 encapsulated in the sub-microcapsules 6 are moved to the protective layer 4 side by applying a magnetic field to the entire surface from the 4 side, and the colored magnetic particles 7 encapsulated in the main microcapsules 5 are disposed on the support 2 side. It is desirable to display the main image to be formed. In this case, manual writing with a magnetic pen is performed from the support 2 side.

  In addition, although the heat utilization efficiency deteriorates, the signal applied from the protective layer 4 side is reversed and heat is applied to a large area to display an image, or the transparent support 2 is formed thinly. It is also possible to apply images from the support 2 side and visually recognize an image from the protective layer side. In either case, the colored magnetic particles 10 enclosed in the sub-microcapsules 6 for hand-written display are finally magnetic. This is the final display of the sub-microcapsule 6 which is moved to the surface to which is applied and is not manually written.

  The display medium 1 and the display device 14 of the present invention can be used as various display boards. In particular, the display content of the main image by a digital image is manually written later to make corrections, corrections, necessary notes, and side points. By performing the above in response to the user's request, the usability of the display board can be improved.

  Next, the display medium 1, the display device 14, and the display method using these according to the present invention will be described with specific examples, but the present invention is not limited to the following examples.

(Preparation of display medium)
First, the main microcapsule 5 in which the colored magnetic particles 7 colored in black, the white nonmagnetic particles 9 and the dispersion medium 8 made of a heat-fusible organic compound are enclosed is prepared. 3 parts by weight of black ferrite magnetic fine particles with an average particle size of about 0.3 μm and 12 parts by weight of titanium oxide fine particles with an average particle size of about 0.3 μm are heated to 60 ° C. to melt paraffin wax (melting point: 40 ° C.). Disperse uniformly in 85 parts by weight, and disperse the dispersion in 200 parts by weight of a 10% gelatin aqueous solution heated to 60 ° C. using a homogenizer at a rotational speed of 2000 rpm for an average particle size of 30 μm. Went.

  Next, 200 parts by weight of a 10% aqueous gum arabic solution is mixed with the obtained dispersion, and further 1000 parts by weight of water is added and maintained at 40 ° C., and a 10% aqueous acetic acid solution is added dropwise so that the pH becomes 4. Adjusted. Thereafter, the mixture was cooled to a liquid temperature of 7 ° C., 10 parts by weight of 30% formalin aqueous solution was added, and 10% sodium hydroxide aqueous solution was added dropwise to adjust to pH 9, and gelatin and gum arabic were used as shells. Capsule 5 was produced.

  The secondary microcapsule 6 comprises 2 parts by weight of red magnetic particles containing ferrite particles having an average particle diameter of about 0.3 μm, 11 parts by weight of white titanium oxide having an average particle diameter of about 0.3 μm, and 85 parts by weight of dibutyl phthalate. The mixture was mixed, and 0.5 parts by weight of the antisettling agent Aerosil was added thereto, and the mixture was prepared by the same process as that for the main microcapsule 5.

  Next, on the transparent poly (ethylene terephthalate) film (support 2) having a thickness of 30 μm as a coating liquid in which the main microcapsules 5 and the sub-microcapsules 6 prepared as described above are mixed in a polyvinyl alcohol aqueous solution 5: 1. To form a recording layer 3 having a thickness of 40 μm, and further, protective dust 4 having a thickness of 10 μm is formed on the recording layer 3 using an ultraviolet curable resin such as an AS resin. Produced.

(Display media initialization)
A magnetic field was applied to the entire surface of the display medium 1 manufactured as described above from the protective layer 4 side, that is, from the display surface side, by the magnetic sheet 15, and the entire surface was heated at 80 ° C. by the heat plate 16. By doing so, the dispersion medium 8 made of paraffin wax enclosed in all the main microcapsules 5 was melted, and the colored magnetic particles 7 moved to the display surface side by magnetophoresis. Similarly, the colored magnetic body 10 of the sub-microcapsule 6 also moved to the surface side. Thereby, from the display surface side, it is possible to visually recognize a color in which the black color of the colored magnetic particles 7 sealed in the main microcapsule 5 and the red color of the colored magnetic body 10 sealed in the sub-microcapsule 6 are mixed. White is visually recognized from the side, and the heating and magnetic field application are stopped in this state, whereby the dispersion medium 8 made of paraffin wax of the main microcapsule 5 is solidified, and the display medium 1 in the initial state is obtained.

(Main image (black digital display))
A place where the entire surface of the display medium 1 manufactured as described above is applied with a magnetic field by the magnetic platen roll 17 from the support 2 side, that is, the side opposite to the display surface, and is made black based on the digital signal from the protective layer 4 side. Only was heated selectively to a temperature of 60 ° C. or higher by the thermal head 18. At this time, the dispersion medium 8 made of paraffin wax in the heated main micro cab cell 5 melted, and the colored magnetic particles 7 moved to the support 2 side by magnetophoresis. Further, the colored magnetic particles 10 in the sub-microcapsule 6 moved to the support 2 side regardless of the presence or absence of heating based on the signal. Thereby, from the protective layer 4 side, it becomes possible to visually recognize that only the portion to which heat is applied has changed to white of the white non-magnetic particles 11, and in this state, by stopping the heating and magnetic field application, the main micro The dispersion medium 8 in the cab cell 5 was solidified, and the display medium 1 displaying the main image visually digitally displayed was obtained. At this time, when the same display medium 1 is viewed from the support 2 side, the display is reversed black and white.

(Hand writing)
The main image displayed in black obtained by the above-described means was overwritten with a red line by drawing a line with a magnetic pen (not shown) from the protective layer 4 side.

  According to the above-described image display mechanism using the display medium 1 and the display device 14 of the present invention, the size, mixing ratio, coating amount, and thermal treatment of the main microcapsule 5 and the submicrocapsule 6 are performed. By controlling the resolution of the heating means such as 18, the resolution of the display medium 1 can be improved.

  In the image display embodiment described above, the case where the colored magnetic particles 7 sealed in the main microcapsules 5 of the display medium 1 shown in FIG. 1 are black has been described, but the present invention is limited to this. The colored magnetic particles 7 having an arbitrary color can be selected according to the color desired to be displayed on the finally obtained display screen, and the hand-written magnetic material is set to red. The desired color can be obtained.

  1 is an enlarged schematic cross-sectional view showing an embodiment of a rewritable display medium according to the present invention.   1 is an enlarged schematic cross-sectional view showing an embodiment of a rewritable display device according to the present invention.   It is an expanded sectional schematic diagram which shows different embodiment of the rewritable display apparatus which is this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Display medium, 2 Support body, 3 Recording layer, 4 Protective layer, 5 Main microcapsule, 6 Submicrocapsule, 7 Colored magnetic particle, 8 Dispersion medium, 9 White nonmagnetic particle, 10 Colored magnetic particle, 11 White nonmagnetic Particles, 12 Precipitation inhibitor, 13 Dispersion medium, 14 Display device, 15 Magnetic sheet, 16 Heat plate, 17 Magnetic platen roll, 18 Thermal head

Claims (5)

Main microcapsules enclosing a dispersion medium composed of colored magnetic particles, white nonmagnetic particles, and a heat-meltable organic compound having a melting point of 35 ° C. or higher and 120 ° C. or lower ; colored magnetic particles, white nonmagnetic particles, and high viscosity at room temperature A rewritable display medium comprising a recording layer in which sub-microcapsules enclosing a dispersion medium made of a high-boiling liquid having a boiling point of 240 ° C. to 300 ° C. are arranged on a support made of a nonmagnetic material .   The display medium according to claim 1, a magnetic field applying unit for applying a magnetic field to the display medium, a heat applying unit for applying heat to the display medium, and a subcapsule forming the display medium A rewritable display device comprising a magnetic pen for applying a magnetic field to the colored magnetic particles.   The rewritable display device according to claim 2, wherein the magnetic field applying unit is a magnetic platen roll, and the heat applying unit is a thermal head. Main microcapsules encapsulating a dispersion medium composed of colored magnetic material, white nonmagnetic particles and a heat-meltable organic compound having a melting point of 35 ° C. or higher and 120 ° C. or lower , colored magnetic particles, white nonmagnetic particles, and high viscosity at room temperature Using the rewritable display medium having a recording layer in which sub-microcapsules enclosing a dispersion medium made of a high-boiling liquid having a boiling point of 240 ° C. to 300 ° C. are arranged on a support made of a nonmagnetic material, A main image is displayed by selectively moving the colored magnetic particles by heating to a temperature higher than the melting point of the dispersion medium in the main capsule in a state where a magnetic field is applied to the layer at a desired position, Without affecting the main image display based on the main capsule by applying a magnetic field to the recording layer with a magnetic pen at a temperature at which the dispersion medium in the capsule does not melt. Rewritable image display method characterized in that by moving the colored magnetic particles in the capsule to allow a hand written to the main image.   5. The rewritable method according to claim 4, further comprising an initialization step of erasing all displayed images by heating the entire surface of the recording medium to a temperature equal to or higher than the melting point of the dispersion medium sealed in the main capsule. Image display method.

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