JP4122831B2 - Rewritable display medium, display device, and display method using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rewritable display medium, a display device, and a display using the same, in which a plurality of types of colored magnetic particles encapsulated in the display device are magnetophoresed by applying heat and a magnetic field, and color display and display erasure are performed. Related to the method.
[0002]
[Prior art]
Examples of conventional display devices using electrophoresis and magnetophoresis include various devices disclosed in Japanese Patent Application Laid-Open Nos. 64-86116, 8-54841, and 8-297470. .
Among them, Japanese Patent Application Laid-Open No. 64-86116 discloses an electrophoretic display device that performs a uniform and stable display operation by applying a microcapsule enclosing a dispersion medium and electrophoretic particles.
Japanese Patent Application Laid-Open No. 8-54841 discloses a similar magnetophoretic display device, and in particular, a display device capable of performing a clear display with a high recording speed.
Japanese Patent Application Laid-Open No. 8-297470 discloses a magnetophoretic display device having a structure in which the durability of the microcapsules is enhanced and the back surface is colored in various colors.
[0003]
[Problems to be solved by the invention]
However, the image display panels used in the various electrophoretic display devices and the magnetophoretic display devices as described above are limited to the background color, the characters, and the design colors. It was not possible to achieve full color display that displayed many colors.
[0004]
On the other hand, as a magnetic recording medium capable of performing color display, for example, as described in Japanese Patent Laid-Open No. 1-63991, the N pole and the S pole of the magnetic particles are colored in different colors, and the magnetic force There is known a technique in which color display is performed by rotating magnetic particles by application of.
[0005]
Japanese Laid-Open Patent Publication No. 4-175196 discloses a magnetic recording medium that performs color display by coloring magnetic particles having different magnetic characteristics in different colors and controlling the magnetic field intensity.
[0006]
However, in the magnetic recording medium described in Japanese Patent Application Laid-Open No. 1-63991, a process such as coloring by coloring each fine magnetic particle, or the N pole and S pole of the magnetic particle are different. Since the process of coloring the color is extremely complicated, there is a problem that it is difficult to strictly perform the color coding of each pole.
[0007]
In the magnetic recording medium described in JP-A-4-175196, it is difficult to control the magnetic field strength at the time of display, and it is difficult to display a clear image due to the ambiguity of the magnetic field control. There is a problem that there is.
[0008]
On the other hand, Japanese Patent Application Laid-Open No. 2000-35598 discloses a technique in which electrophoretic particles colored in different colors are enclosed in microcapsules and color display is performed by applying an electric field. There is a problem that it is necessary to provide an independent electrode, which increases the manufacturing cost.
[0009]
Accordingly, the present invention provides a display medium, a display device, and a display method using these, which are capable of simultaneous multi-color display, have excellent image stability, are inexpensive, and use full-color magnetophoresis.
[0010]
[Means for Solving the Problems]
In the present invention, there is provided a display medium having a recording layer on a support made of a non-magnetic material, wherein the recording layer has a plurality of minute void members having voids arranged therein, and the inside of the minute void member. Each of the colored magnetic particles is dispersed in a heat-fusible organic compound that exhibits a solid state at room temperature, The colored magnetic particles are colored in any one of a plurality of colors, and the melting point of the heat-fusible organic compound enclosed in the microvoid member identified by the color of the colored magnetic particles is within the microvoid member. Selected to be different for each color of the colored magnetic particles dispersed in the Applying a magnetic field to the recording layer, The display target location of the recording layer is Of heat-meltable organic compounds plural Melting point One temperature region selected from multiple temperature regions separated by Heated at a temperature according to , By melting any hot-meltable organic compound, dispersed in the molten hot-melt organic compound Provided is a rewritable display medium that selectively moves colored magnetic particles to display an image.
[0011]
Further, in the present invention, a plurality of minute void members having voids inside are arranged on a support made of a nonmagnetic material, and a recording layer is provided. Inside Each of the colored magnetic particles is dispersed in a heat-fusible organic compound that exhibits a solid state at room temperature. The colored magnetic particles are colored in any one of a plurality of colors, and the melting point of the heat-fusible organic compound enclosed in the microscopic void member distinguished by the color of the colored magnetic particles is It is selected to be different for each color of the colored magnetic particles dispersed in the member. A display medium having a structure; a magnetic field applying unit that applies a magnetic field to the recording layer of the display medium; and a heating unit that heats the recording layer. The magnetic layer is applied by the magnetic field applying unit, and the recording layer is heated by the heating unit. Display target location The heat-meltable organic compound plural Melting point One temperature region selected from multiple temperature regions separated by Heating at a temperature according to Dispersed in the molten hot-melt organic compound by melting any hot-melt organic compound Provided is a display device that displays an image by selectively moving colored magnetic particles.
[0012]
Further, in the present invention, a microporous member having a recording layer in which a plurality of microvoided members having voids are arranged on a support made of a nonmagnetic material is provided. Inside Each of the colored magnetic particles is dispersed in a heat-fusible organic compound that exhibits a solid state at room temperature. The colored magnetic particles are colored in any one of a plurality of colors, and the melting point of the heat-fusible organic compound enclosed in the microscopic void member distinguished by the color of the colored magnetic particles is It is selected to be different for each color of the colored magnetic particles dispersed in the member. Using a display medium having a configuration, a magnetic field is applied to the recording layer, and the recording layer is Display target location The the above Of heat-meltable organic compounds plural Melting point One temperature region selected from multiple temperature regions separated by Heated at a temperature according to , By melting any hot-melt organic compound, dispersed in the molten hot-melt organic compound Provided is a display method for displaying an image by selectively moving the colored magnetic particles.
[0013]
According to the present invention, the colored magnetic particles constituting the recording layer are selectively moved by selectively melting the heat-fusible organic compound by a heating means such as a thermal head in a state where a magnetic field is applied. Accordingly, it is possible to provide a rewritable display medium, display device, and display method capable of performing full-color display with clear color tone and high resolution and capable of erasing sharp and clear image display. .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, the display medium, the display device, and the display method of the present invention are not limited to the following examples.
[0015]
FIG. 1 shows a schematic sectional view of an example of the display medium of the present invention.
As shown in FIG. 1, the display medium 10 of the present invention has a configuration in which a recording layer 12 and a protective layer 13 are laminated on a support 11. The recording layer 12 has a configuration in which minute gap members 14 are filled and arranged, and a display material 24 including inorganic pigment particles 20 and colored magnetic particles 21 to 23 of a predetermined color is contained in the minute gap portions 14. It is assumed that it is dispersed in a heat-meltable organic compound 25 that exhibits a solid phase at room temperature.
In the display medium 10 shown in FIG. 1, the first to third colored magnetic particles 21 to 23 colored in yellow, magenta, and cyan are dispersed in the heat-meltable organic compounds 25a, 25b, and 25c, respectively. Thus, it is assumed that the minute gap members 14 distinguished by these colors are filled and arranged on the support 11.
In FIG. 1, the microscopic gap members 14 are filled and arranged in a planar shape on the support 11, but the present invention is not limited to this example, and in consideration of the sharpness and resolution of the color tone of the display image, It is good also as what was laminated | stacked.
Hereinafter, the display medium 10 of the present invention will be described in detail.
[0016]
The support 11 is formed of a non-magnetic material, for example, synthetic resins such as polyvinyl chloride, polyester, polycarbonate, polymethyl methacrylate, polystyrene, and polyethylene terephthalate, natural resin, paper, synthetic paper, metal, ceramics Etc. can be used alone or in combination. As for the shape of the support 11, a conventionally known shape such as a card shape, a sheet shape, a film shape and the like can be selected according to the application, and conventionally known physical properties required according to the application, for example, strength, rigidity, It is good also as what added concealment property, light impermeability, etc.
[0017]
The recording layer 12 has a configuration in which minute gap members 14 having gaps inside are filled and arranged. The microvoid member 14 is not particularly limited. For example, a microcapsule, a capillary, or a cell that can enclose a dispersion medium can be applied to form a microvoid structure. Any known one can be applied. In addition, by forming the void structure more finely, the resolution in the finally obtained display medium 10 and display device can be improved.
[0018]
Next, the inorganic pigment particles 20, the colored magnetic particles 21 to 23, and the heat-meltable organic compound 25 that exhibits a solid state at room temperature will be described.
[0019]
The material of the inorganic pigment particles 20 is not particularly limited, and for example, conventionally known materials such as titanium oxide, alumina, zinc oxide, silica, barium titanate, and barium zirconate can be applied. Especially titanium oxide (TiO ₂ ), Alumina (Al ₂ O _Three ), Zinc oxide (ZnO), silica (silicon oxide: SiO ₂ It is suitable for improving the contrast of the display medium 10 from which a white-colored inorganic oxide such as) is finally obtained.
[0020]
Examples of the material for forming the colored magnetic particles 21 to 23 include stainless steel such as iron, nickel, iron / nickel alloy, iron / nickel / chromium alloy, cobalt, cobalt / aluminum alloy, samarium / cobalt alloy, and the like. The fine particles in the form of flakes using an atomizer, a hammer mill or the like can be applied as the colored magnetic particles 21 to 23.
[0021]
The colored magnetic particles 21 to 23 are colored according to the color desired to be displayed on the finally obtained display medium 10. For example, when performing full color display on the display medium 10, the three primary colors yellow, It is assumed that the first to third colored magnetic particles 21 to 23 colored magenta and cyan are enclosed in different microscopic gap members 14, respectively.
[0022]
The colored magnetic particles 21 to 23 can be colored by coating the magnetic particles with, for example, a Co-Mn composite oxide, or a synthetic resin paint made of hematite or the like and polyester or acrylic resin. The material for coloring the magnetic particles is not limited to the above paint, and various conventionally known dyes can be appropriately used.
[0023]
The colored magnetic particles 21 to 23 are preferably those having a particle diameter of 5 to 30 μm in consideration of ease of movement by applying magnetism, which will be described later, and image contrast in the display medium 10. As the colored magnetic particles 21 to 23, various conventionally known shapes can be applied as long as the shapes do not hinder movement due to magnetic application, such as a spherical shape or a needle shape.
[0024]
The heat-meltable organic compound 25 in which the inorganic pigment particles 20 and the colored magnetic particles 21 to 23 are dispersed exhibits a solid phase at room temperature (about 10 to 30 ° C.) and is heated to a temperature higher than room temperature (about 35 to 35 ° C.). For example, natural or synthetic waxes such as paraffin wax and carnauba wax, natural or synthetic resins, carboxylic acid esters, etc. can be used alone or in combination as appropriate. . In particular, it is preferable that the change from the solid phase state to the fluid state is steep according to the temperature change.
[0025]
As the hot-melt organic compound 25, those having different melting points corresponding to the colors of the colored magnetic particles are applied.
That is, as described above, the first to third colored magnetic particles 21 to 23 colored in three primary colors yellow, magenta, and cyan are encapsulated in different microscopic gap members 14, respectively. Is selected so that the melting point of the heat-meltable organic compound 25 enclosed in the microscopic gap member 14 distinguished by the colors of the colored magnetic particles 21 to 23 is different for each color of the colored magnetic particles. To do.
For example, the melting point of the hot-melt organic compound 25a that disperses the first colored magnetic particles 21 is T1, the melting point of the hot-melt organic compound 25b that disperses the second colored magnetic particles 22 is T2, and the third colored magnetic particles. When T3 is the melting point of the hot-melt organic compound 25c in which 23 is dispersed, T1>T2> T3 is selected.
[0026]
Specifically, the heat-meltable organic compound 25a that disperses the yellow first colored magnetic particles 21 has a melting point of about 90 ° C., and the heat-meltable organic compound 25b that disperses the magenta second colored magnetic particles 22 has a melting point. As for the hot-melt organic compound 25c in which the cyan third colored magnetic particles 23 are dispersed at about 65 ° C., paraffin wax having a melting point of about 40 ° C. can be applied.
The melting point of the heat-meltable organic compound 25 can be specified within a suitable range by selecting the number of hydrocarbon chains in the molecular structure, for example.
[0027]
The fine void member 14 which is a so-called shell material enclosing the inorganic pigment particles 20, the colored magnetic particles 21 to 23 and the heat-meltable organic compound 25 as described above includes, for example, an acrylic resin, a methacrylic resin, a polystyrene resin, It can be formed of a known resin material such as polyester resin, polyurethane resin, polyurea resin, polyamide resin, epoxy resin, natural resin, etc., alone or in a mixture of two or more.
[0028]
As the microscopic void member 14, a microcapsule in which a so-called core substance mainly composed of the inorganic pigment particles 20, the colored magnetic particles 21 to 23, and the hot-melt organic compound 25 is encapsulated is preferably used. The following are mentioned as a manufacturing method of such a microcapsule.
[0029]
For example, a phase separation method in which a concentrated polymer phase is separated around the core material dispersed in the polymer solution, and a liquid-cured coating film in which the polymer is cured around the core material in the polymer solution by a polymer curing test agent or the like. Method, an in-situ polymerization method in which a monomer or a polymerization catalyst is supplied from either the inner phase or the outer phase of the emulsion in which the core material is dispersed and the surface of the core material is covered with a polymer, and the emulsion in which the core material is dispersed A microencapsulation technique such as an interfacial polymerization method in which a monomer is supplied from both an internal phase and an external phase is suitable, but it is not limited to these methods.
[0030]
Among the above methods, microcapsules having a uniform particle diameter and having the core substance uniformly dispersed can be manufactured by manufacturing using an in situ polymerization method or a phase separation method. Examples of the polymerizable monomer used in these methods include acrylic acid esters, methacrylic acid esters, styrene and derivatives thereof, isocyanates, various amines, and compounds having an epoxy group.
As described above, the recording layer 12 can be formed by dispersing the fine gap member 14 made of, for example, microcapsules in a predetermined binder and coating the dispersion on the support 11. As the binder, for example, a water-based binder, a solvent-based binder, an emulsion-based binder, and the like can be applied.
[0031]
Specifically, the recording layer 12 includes a conventionally known printing method such as an offset printing method, a gravure printing method, and a silk screen printing method, a coating method such as a roll coating method and a knife edge method, and a micro gap member 14 such as the microcapsule. A transfer method using a transfer sheet mixed with the above, an ink jet method in which ink containing the above-described microcapsules or the like is sprayed on the support 11, and the above-described microcapsules or the like mixed between the support 11 and a protective layer 13 described later. It can be produced by various methods such as a method of filling a solution, and can be appropriately selected according to the intended use and quantity of the display medium 10.
[0032]
Next, the protective layer 13 will be described.
Examples of the material for forming the protective layer 13 include epoxy resins, tetrafluoroethylene, polyvinyl chloride, polyester, polycarbonate, polymethyl methacrylate, polystyrene, polyethylene terephthalate, and other synthetic resins, natural resins, and the like.
The protective layer 13 holds the recording layer 12 formed on the support 11, and allows the colored magnetic particles 21 to 23 and the inorganic pigment particles 20 enclosed in the minute gap member 14 to be visually recognized from the outside. It is necessary to have transparency. Further, in order to maintain the mechanical strength of the display surface of the display medium 10, a necessary film thickness is appropriately selected and formed.
[0033]
Next, a display device that forms an image on the above-described display medium 10 of the present invention and an image display method using these will be described.
FIG. 2 shows a schematic configuration diagram of an example of the display device of the present invention.
The display device 30 of the present invention includes the display medium 10 shown in FIG. 1, a magnetic field applying unit 31 that applies a magnetic field, and a heating unit 32.
The magnetic field application unit 31 has a function of applying a magnetic field to the colored magnetic particles 21 to 23 of the recording layer 12, and the heating unit 32 has a function of heating the hot-melt organic compound 25 of the recording layer 12. Have.
FIG. 2 shows a state in which the magnetic field applying means 31 and the heating means 32 are arranged on the side of the display medium 10 facing the protective layer 13, but each of these faces the support 11 independently. It can be arranged on the side, and can be moved as appropriate according to the display color of image formation described later.
[0034]
Next, a method for displaying an image using the display medium 10 and the display device 30 of the present invention described above will be described. The image display method of the present invention is not limited to the following examples.
In this example, three primary colors are displayed on the display medium 10 shown in FIG. 1, the first colored magnetic particles 21 are yellow, the second colored magnetic particles 22 are magenta, and the third colored magnetic particles 23 are Cyan colored ones were applied.
[0035]
As described above, the first to third colored magnetic particles 21 to 23 colored yellow, magenta, and cyan are encapsulated in different microscopic gap members 14, respectively. The melting point of the heat-fusible organic compound 25 enclosed in the microscopic gap member 14 distinguished by the color is selected so as to be different for each color of the colored magnetic particles, and the first colored magnetic particles 21 are dispersed. The melting point of the hot-melt organic compound 25a is T1, the melting point of the hot-melt organic compound 25b that disperses the second colored magnetic particles 22 is T2, and the melting point of the hot-melt organic compound 25c that disperses the third colored magnetic particles 23. When T3 is set to T3>T2> T3.
[0036]
Next, a display method will be described.
First, in the state shown in FIG. 2, all of the inorganic pigment particles (white) enclosed in the three types of microvoid members 14 are on the protective layer 13 side, that is, the display surface side, and all the microvoid members 14 display white. The white display (erased state) is made on the entire surface.
[0037]
In the case of displaying yellow, first, as shown in FIG. 3, the heating means 32 is heated to a temperature (t> T1) higher than the melting point T1 of the hot-melt organic compound 25a, and all the minute gap members are obtained. The hot-melt organic compound 25 in 14 is melted. And the magnetic field application means 31 is arrange | positioned at the protective layer 13 formation surface side, ie, the display surface side, a magnetic field is applied, and the 1st-3rd colored magnetic particles 21-23 are magnetophoresed. If it does in this way, as shown in FIG. 3, all the 1st-3rd colored magnetic particles 21-23 will move to the display surface side, and it will be in the state by which the black display was made | formed on the whole surface.
Next, as shown in FIG. 4, the heating means 32 is heated to a temperature lower than the melting point T1 of the hot-melt organic compound 25a and higher than the melting point T of the hot-melt organic compound 25b (T1>t> T2). Only the heat-meltable organic compound 25a is solidified and the other heat-meltable organic compounds 25b and 25c are dissolved. Then, the magnetic field applying means 31 is arranged on the support 11 side, a magnetic field is applied, and the second and third colored magnetic particles 22 and 23 are migrated to the support 11 side.
In this way, only the first colored magnetic particles 21 colored yellow are fixed on the display surface, and the second and third colored magnetic particles 22 and 23 are transferred to the back surface. Yellow display can be performed.
[0038]
Next, a case where magenta display is performed will be described.
First, as shown in FIG. 2, a white display (erased state) is formed on the entire surface. Next, as shown in FIG. 5, the heating means 32 sets the temperature lower than the melting point T1 of the hot-melt organic compound 25a and higher than the melting point T2 of the hot-melt organic compound 25b (T1>t> T2). The meltable organic compounds 25b and 25c are in a dissolved state.
Then, the magnetic field applying means 31 is arranged on the protective layer 13 side, that is, the display surface side, a magnetic field is applied, and the second and third colored magnetic particles 22 and 23 migrate to the display surface side. If it does in this way, as shown in FIG. 5, the 2nd and 3rd colored magnetic particles 22 and 23 will move to the display surface side, and it will be in the state by which the mixed color display of magenta and cyan was made.
Next, as shown in FIG. 6, the heating means 32 is set to a temperature lower than the melting point T2 of the hot-melt organic compound 25b and higher than the melting point T3 of the hot-melt organic compound 25c (T2>t> T3). The meltable organic compound 25a and the heat-meltable organic compound 25b are solidified, and only the heat-meltable organic compound 25c is dissolved.
And the magnetic field application means 31 is arrange | positioned at the support body 11 side, a magnetic field is applied, and the 3rd colored magnetic particle 23 is migrated to the support body 11 side.
In this way, only the second colored magnetic particles 22 colored magenta are fixed on the display surface, and the first and third colored magnetic particles 21 and 23 are transferred to the back surface. Magenta can be displayed.
[0039]
Next, a case where cyan display is performed will be described.
First, as shown in FIG. 2, a white display (erased state) is formed on the entire surface. Next, as shown in FIG. 7, the heating means 32 is set to a temperature lower than the melting point T2 of the hot-melt organic compound 25b and higher than the melting point T3 of the hot-melt organic compound 25c (T2>t> T3). The meltable organic compound 25a and the heat-meltable organic compound 25b are solidified, and only the heat-meltable organic compound 25c is dissolved.
Then, the magnetic field applying means 31 is arranged on the protective layer 13 side, that is, the display surface side, a magnetic field is applied, and the third colored magnetic particles 23 migrate to the display surface side.
In this way, only the third colored magnetic particles 23 colored cyan are fixed on the display surface, and the first and second colored magnetic particles 21 and 22 are transferred to the back surface. Cyan display can be performed.
[0040]
As described above, in the display medium 10 and the display device 30 of the present invention, a magnetic field is applied and heated at a temperature corresponding to the melting point of each of the hot-melt organic compounds 25a to 25c to select the hot-melt organic compound. By selectively moving the colored magnetic particles 21 to 23 dispersed in the molten heat-fusible organic compound, and finally displaying the desired colors of the three primary colors and a combination of these colors, Alternatively, the display can be erased.
[0041]
Specifically, the display medium 10 and the display device 30 of the present invention include various cards such as a point card, a medical examination ticket, a commuter pass, a recording bulletin board, an advertising board, a memo board, a blackboard, a white board, a portable memo pad, and an infant. It can be applied to toys, educational materials, calligraphy boards, display boards for various game machines, and the like.
[0042]
Next, the display medium, the display device, 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 examples shown below.
[0043]
〔Example〕
(Preparation of display medium)
First, microcapsules in which yellow colored magnetic particles are enclosed are prepared.
5 parts by weight of yellow colored magnetic particles mainly composed of 70% Fe, and white inorganic pigment particles (TiO 2) ₂ ) 1 part by weight is uniformly dispersed in 6 parts by weight of paraffin wax having a melting point of 90 ° C. heated and melted at 100 ° C., and this dispersion is used in 200 parts by weight of a 10% gelatin aqueous solution heated to 95 ° C. using a homogenizer. Then, a dispersion treatment was performed at a rotational speed of 2000 rpm for about 5 minutes until the average particle size became 75 μm.
To the dispersion obtained as described above, 200 parts by weight of a 10% aqueous gum arabic solution was added, and further 1000 parts by weight of water was added, and the temperature was kept at 40 ° C. It adjusted so that it might become. Thereafter, the liquid temperature is cooled to 7 ° C., 10 parts by weight of 30% formalin aqueous solution is added, 10% aqueous sodium hydroxide solution is added dropwise to adjust the pH to 9, and gelatin and gum arabic shell microcapsules A was produced.
[0044]
The magenta colored magnetic particles are applied in place of the yellow colored magnetic particles, the paraffin wax having a melting point of 65 ° C. is applied in place of the paraffin wax having the melting point of 90 ° C., and magenta is obtained by the same process as described above. A microcapsule B encapsulating the colored magnetic particles was prepared.
[0045]
A cyan colored magnetic particle is applied in place of the yellow colored magnetic particle, and a paraffin wax having a melting point of 40 ° C. is applied in place of the paraffin wax having a melting point of 90 ° C. The microcapsule C encapsulating the colored magnetic particles was prepared.
[0046]
Next, on a transparent polyethylene terephthalate film having a thickness of 30 μm, a coating liquid in which the microcapsules A, B, and C prepared as described above were uniformly dispersed in an aqueous polyvinyl alcohol solution was applied to form a recording layer.
Further, a protective layer having a thickness of 3 μm was formed on the recording layer using an acrylic resin, and the intended display medium 10 of the present invention was produced.
[0047]
(Display is cleared)
A magnetic field applying means was disposed on the support side of the display medium produced as described above to apply a magnetic field, and the entire surface was heated at 95 ° C. By doing so, the paraffin wax in all the microcapsules was melted, and each colored magnetic particle was moved to the support side, that is, the side opposite to the display surface side by magnetophoresis.
As a result, only the white inorganic pigment particles can be seen from the display surface side. By stopping the heating and the magnetic field application in this state, the paraffin wax is solidified and the display medium 10 in the erased state is obtained.
[0048]
(Displays black)
A magnetic field applying means is arranged on the display surface side of the display medium manufactured as described above, and a magnetic field is applied, and only a place where display is desired is selectively performed at a temperature of 90 ° C. or more by a heating means such as a thermal head or a laser. Heat to.
At this time, the paraffin wax in all the microcapsules at the heated location was melted, and each colored magnetic particle moved to the display surface side by magnetophoresis.
As a result, yellow, magenta and cyan colored magnetic particles can be visually recognized from the display surface side. By stopping heating and magnetic field application in this state, the paraffin wax is solidified and visually becomes black. The displayed display medium 10 is obtained.
[0049]
(Displays yellow)
A magnetic field applying means is arranged on the display surface side of the display medium manufactured as described above, and a magnetic field is applied, and only a place where display is desired is selectively performed at a temperature of 90 ° C. or more by a heating means such as a thermal head or a laser. Heat to. At this time, the paraffin wax in all the microcapsules at the heated location was melted, and each colored magnetic particle moved to the display surface side by magnetophoresis.
Next, the magnetic field applying means is arranged on the support side, that is, the surface side opposite to the display surface, and only the place where the display is desired is selectively adjusted by the heating means so that the temperature is 65 ° C. or higher and 90 ° C. or lower. did. As a result, only the paraffin wax in the microcapsules enclosing the magenta and cyan colored magnetic particles was melted, and the magenta and cyan colored magnetic particles were transferred to the support side by magnetophoresis.
By stopping the heating and magnetic field application in this state, the paraffin wax is solidified and the display medium 10 visually displayed in yellow is obtained.
[0050]
(Displays magenta)
The display medium manufactured as described above is first set in an erased state (white display). A magnetic field application unit is arranged on the display surface side to apply a magnetic field, and only a place where display is desired is selectively heated to a temperature of 65 ° C. or higher and 90 ° C. or lower by a heating unit such as a thermal head or a laser. As a result, only the paraffin wax in the microcapsules enclosing magenta and cyan colored magnetic particles was melted, and the magenta and cyan colored magnetic particles were moved to the display surface side by magnetophoresis.
Next, the magnetic field applying means is arranged on the support side, that is, the surface opposite to the display surface to apply the magnetic field, and only the place where display is desired is selectively performed at 40 ° C. by a heating means such as a thermal head or a laser. The temperature was adjusted to 65 ° C. or lower. As a result, only the paraffin wax in the microcapsules enclosing the cyan colored magnetic particles was melted, and the cyan colored magnetic particles were transferred to the support side by magnetophoresis.
By stopping heating and magnetic field application in this state, the paraffin wax is solidified, and the display medium 10 visually displayed on magenta is obtained.
[0051]
(Displays cyan)
The display medium manufactured as described above is first set in an erased state (white display).
A magnetic field applying means is arranged on the display surface side to apply a magnetic field, and only a place where display is desired is selectively heated to a temperature of 40 ° C. or higher and 65 ° C. or lower by heating means such as a thermal head or a laser. As a result, only the paraffin wax in the microcapsules enclosing the cyan colored magnetic particles was melted, and the cyan colored magnetic particles moved to the display surface side by magnetophoresis.
By stopping heating and magnetic field application in this state, the paraffin wax is solidified, and the display medium 10 visually displayed on magenta is obtained.
[0052]
(Displays neutral colors)
By combining the display of yellow, magenta and cyan as described above, an arbitrary intermediate color can be displayed, and a full color image can also be displayed.
[0053]
According to the above-described image display mechanism using the display medium and the display device of the present invention, the size of the minute gap member such as the microcapsule in which the colored magnetic particles of each color are encapsulated, and the thermal head for performing heat treatment on the member. The resolution of the display medium can be improved by controlling the resolution of the heating means.
[0054]
In the example of the image display described above, the case where the colored magnetic particles sealed in the minute gap member 14 of the display medium 10 in FIG. 1 are yellow, magenta, and cyan has been described, but the present invention is limited to the above-described example. Instead, any colored magnetic particles can be selected according to the color desired to be displayed on the finally obtained display screen.
[0055]
In the display medium and the display device shown in the above-described example, in order to make the display erased, the colored magnetic particles 21 to 23 in the minute gap member 14 are placed on the support 11 side as shown in FIG. However, the present invention is not limited to the above-described example, and the heat-meltable organic compounds 25a to 25c that are dispersion media themselves are colored. By making white so that high contrast can be obtained for each color of the magnetic particles 21 to 23, the amount of the inorganic pigment particles 20 in the minute gap member 14 can be reduced or not used at all. .
[0056]
【The invention's effect】
According to the present invention, the colored magnetic particles constituting the recording layer are selectively moved by selectively melting the heat-fusible organic compound by a heating means such as a thermal head in a state where a magnetic field is applied. Accordingly, it is possible to provide a rewritable display medium, a display device, and a display method that can perform full-color display with a clear color tone, high resolution, and can perform sharp and clear image display erasure. It was.
[0057]
In particular, by applying a heat-meltable organic compound having a different melting point for each color of the colored magnetic particles, it is possible to display an image for each color only by controlling the heating temperature, there is no color mixing, and a clear Color image display is now possible.
[0058]
Further, by applying particularly white particles as the inorganic pigment particles, it is possible to obtain contrast with each colored magnetic particle, high resolution, and clearer image display.
[0059]
In addition, according to the display medium and the display device of the present invention, it is possible to easily display an image by combining heating at a relatively low temperature enough to melt the heat-fusible organic compound and magnetic application. As a result, it is possible to display a clear image with very little energy consumption.
[0060]
Further, according to the display medium and the display device of the present invention, the colored magnetic particles are dispersed in the dispersion medium made of a heat-fusible organic compound that shows a solid phase at room temperature in the minute gap member, and are fixed except at the time of recording / erasing. Therefore, even when magnetism is applied from the outside after information recording, the colored magnetic particles do not move and an extremely stable recording state can be obtained.
[0061]
Further, in the display medium, display device, and display method of the present invention, image formation and erasure are performed by moving the colored magnetic particles dispersed in the heat-fusible organic compound melted by the operation of the heating means by applying magnetism. Therefore, an extremely fine image can be formed by increasing the operation accuracy of the heating means.
[0062]
In addition, since the recording layer constituting the display medium of the present invention can be formed by applying a coating liquid containing a minute gap member on a support, it can be produced by a very simple manufacturing process, It was possible to produce at an extremely low cost.
[Brief description of the drawings]
FIG. 1 shows a schematic cross-sectional view of a display medium of the present invention.
FIG. 2 is a schematic sectional view of the display device of the present invention.
FIG. 3 is a state diagram for performing image formation in the display medium and the display device of the present invention.
FIG. 4 is a state diagram for performing image formation in the display medium and the display device of the present invention.
FIG. 5 shows a state diagram for performing image formation in the display medium and display device of the present invention.
FIG. 6 is a state diagram for performing image formation in the display medium and the display device of the present invention.
FIG. 7 shows a state diagram for performing image formation in the display medium and display device of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Display medium, 11 ... Supporting substrate, 12 ... Recording layer, 13 ... Protective layer, 14 ... Micro gap member, 20 ... Inorganic pigment particle, 21 ... First colored magnetic particle, 22 ... ... 2nd colored magnetic particles, 23 ... 3rd colored magnetic particles, 24 ... display material, 25, 25a, 25b, 25c ... hot-melt organic compound, 30 ... display device, 31 ... magnetic field Applying means, 32 ... heating means

Claims (11)

A display medium having a recording layer on a support made of a nonmagnetic material,
In the recording layer, a plurality of minute void members having voids inside are arranged,
Inside the microscopic void member, each colored magnetic particle is dispersed in a heat-fusible organic compound that exhibits a solid state at room temperature,
The colored magnetic particles are colored in any one of a plurality of colors, and the melting point of the heat-fusible organic compound enclosed in the microvoid member identified by the color of the colored magnetic particles is within the microvoid member. Selected to be different for each color of the colored magnetic particles dispersed in the
A magnetic field is applied to the recording layer, and a display target location of the recording layer is heated at a temperature corresponding to one temperature region selected from a plurality of temperature regions separated by a plurality of melting points of the hot-melt organic compound. In addition, by melting an arbitrary heat-meltable organic compound, the colored magnetic particles dispersed in the melted heat-meltable organic compound are selectively moved to display an image, which can be rewritten. Display medium.   2. The rewritable according to claim 1, wherein the colored magnetic particles and the inorganic pigment particles are dispersed in a heat-fusible organic compound that exhibits a solid state at room temperature inside the microvoid member. Display medium.   The rewritable display medium according to claim 1, wherein the microscopic gap members constituting the recording layer are filled and arranged in a planar shape on the support. The colored magnetic particles rewritable display medium according to any one of claims 1 to 3, characterized in that it is colored in one of three primary colors.   The rewritable display medium according to any one of claims 1 to 4, wherein a melting point of the heat-meltable organic compound exhibiting a solid state at normal temperature is 35 ° C or higher and 120 ° C or lower. . On a support made of a nonmagnetic material, there is a recording layer in which a plurality of minute void members having voids are arranged inside, and in each of the minute void members, the colored magnetic particles are in a solid state at room temperature. Ri Na are dispersed in heat-fusible organic compounds shown, the colored magnetic particles colored in any color of a plurality of colors, the heat sealed in the small air gap member which is distinguished by the color of the colored magnetic particles A display medium having a configuration in which the melting point of the fusible organic compound is selected to be different for each color of the colored magnetic particles dispersed in the microscopic gap member ;
Magnetic field applying means for applying a magnetic field to the recording layer;
Heating means for heating the recording layer,
While applying a magnetic field by said magnetic field applying means, by the heating means, first temperature region selected display target location of the recording layer from a plurality of temperature zones partitioned by the plurality of the melting point of the heat-fusible organic compound by heating at a temperature corresponding to, by melting any heat-fusible organic compound, and the colored magnetic particles dispersed in a heat-fusible organic compound the melt selectively moved, by performing image display A display device.   The display device according to claim 6, wherein the colored magnetic particles and the inorganic pigment particles are dispersed in a heat-fusible organic compound that exhibits a solid state at room temperature inside the microvoid member. .   8. The display device according to claim 6, wherein the microscopic gap members constituting the recording layer are filled and arranged in a planar shape on the support. Display device according to any one of claims 6 to 8, wherein said colored magnetic particles that are colored in any one of the three primary colors.   10. The display device according to claim 6, wherein a melting point of the hot-melt organic compound is 35 ° C. or higher and 120 ° C. or lower. The recording layer has a recording layer on a support made of a non-magnetic material, and the recording layer has a plurality of microscopic void members arranged therein. Ri but Na are dispersed in heat-fusible organic compounds showing a solid state at room temperature, the colored magnetic particles colored in any color of a plurality of colors, the minute gap member which is distinguished by the color of the colored magnetic particles Using a display medium having a configuration in which the melting point of the heat-fusible organic compound enclosed in the inside is selected so as to be different for each color of the colored magnetic particles dispersed in the minute gap member ,
A magnetic field is applied to the recording layer, and a display target location of the recording layer is heated at a temperature corresponding to one temperature region selected from a plurality of temperature regions separated by a plurality of melting points of the hot-melt organic compound. And a method of displaying an image by selectively moving the colored magnetic particles dispersed in the molten heat-fusible organic compound by melting an arbitrary heat-fusible organic compound. .

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