JP3239140B2 - Color display panel, color display device, and color display method using the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a color display panel, a color display device, and a color display method using magnetophoresis.

[Prior Art] A typical display method uses an electronic blackboard, which moves a writing instrument such as a board marker in a X or Y direction on a panel such as a whiteboard while responding to input information. To record and display predetermined characters and figures. However, this display method has problems such as the use of consumables such as writing instruments, and the removal of dry powder of the board marker when erased. Therefore, it is possible to easily display and erase on a relatively large screen without using writing instruments. A display method using magnetism has attracted attention. As a display method using such magnetism, for example, the following method has been proposed.

Create a display cell between the magnetic recording sheet and the transparent sheet, enclose a dispersion of magnetic particles dispersed in the cell, form a magnetic latent image on the magnetic recording sheet using a magnetic head,
A method in which magnetic particles are attracted by magnetophoresis using the magnetic latent image to produce a contrast between a non-magnetized portion and a display (Japanese Patent Publication No. 56-852).

A display cell is formed between the magnetic recording sheet and the transparent sheet, a dispersion liquid in which foil-like reflective magnetic particles are dispersed is sealed in the cell, and a magnetic head is used to form a magnetic latent image on the magnetic recording sheet. A method in which reflective magnetic particles are oriented by this magnetic latent image to form a contrast as in the case of liquid crystal and display is performed (Japanese Patent Laid-Open No. 61-233425).

A display panel is formed between at least two sheets having a transparent display surface, and a magnetic panel in which a dispersion liquid in which black magnetic particles are dispersed in a white medium is sealed in the cell. Magnetic particles are gathered on the opposite side (back side) of the surface, the display surface is kept in a state where the magnetic particles are concealed by the white dispersion medium, and then the display surface is applied with a magnetic field from a display surface using a magnetic pen made of magnet. A method in which the magnetic particles gathered on the side are subjected to magnetophoresis on the surface to perform display with a contrast between the white dispersion medium and the black magnetic particles (JP-A-59-21)
No. 4700).

[Problems to be solved by the invention]

However, the conventional display method using magnetism has the following problems.

Since the above-mentioned display methods use a magnetic recording sheet and a magnetic head, it is difficult to enlarge the screen, and the application is limited to a small one such as a card. In addition, since the magnetic particles take on a brown or black color, they are limited to white / black display.

The above-mentioned display method utilizes a device for displaying with a magnetic pen composed of a simple magnet without using a magnetic recording sheet or a magnetic head. Here, a display panel has one side and a depth on the entire surface of a transparent plastic. About 2m
A honeycomb-shaped cell of about m is formed, and a dispersion liquid of a white pigment and magnetic particles is sealed in the cell.First, the entire magnetic particles are sucked and moved to the back side by a uniform magnetic field for erasing from the back side. The back side forms a state concealed by a white pigment, and then by applying a magnetic field for display or recording with a magnetic pen made of magnet from the display side, the magnetic particles are migrated from the back side to display. A relatively large screen is also possible.

However, this also has the following disadvantages.

(I) Since the total amount of the magnetic particles sealed in the honeycomb-shaped cell is indicated by the suction movement from the back side to the front side, the minimum unit is determined by the size of the cell,
No higher resolution can be obtained.

(Ii) It is difficult to form a honeycomb-shaped cell and to enclose the dispersion liquid in the cell without bubbles, and it is extremely difficult to enlarge the screen as large as a blackboard.

(Iii) The display body exhibits rigidity due to the honeycomb, and is not flexible.

(Iv) Since the magnetic particles usually show black or black-brown, the display is limited to black / white display.

The present invention provides a flexible color display panel, a color display device, and a color display method using the same, which can solve the above-mentioned drawbacks of the prior art, in particular, the above-mentioned drawbacks of the display method. The purpose is to:

[Means for solving the problem]

In order to achieve the above object, according to the present invention, a magnetic property and a hue or a color tone are different on a non-magnetic support, and
A color display panel provided with a layer of microcapsules having a particle diameter of 80 to 100 μm in which a dispersion liquid of two or more magnetic particles of 10 to 16 μm is sealed is provided.

Further, according to the present invention, the magnetic property and hue or hue are different on a non-magnetic support, and a particle size of 80 to 100 μm in which a dispersion of two or more magnetic particles having a particle size of 10 to 16 μm is sealed. A color display panel provided with a coating layer of microcapsules, an erasing magnet arranged on the support side of the display panel for attracting and moving the entire magnetic particles to the support side, and magnetization characteristics and hue or color tone in the microcapsules Different in action magnetic field strength for selectively attracting and moving magnetic particles different from
1 or more magnetic pens or variable magnetic field strength
A color magnetic display device comprising a magnetic pen of the book is provided.

Further, according to the present invention, the magnetic property and hue or hue are different on the non-magnetic support, and a particle diameter of 80 to 100 μm in which a dispersion of two or more magnetic particles having a particle diameter of 10 to 16 μm is sealed. A color display panel provided with a coating layer of microcapsules is used, and after the entire magnetic particles are attracted and moved toward the support by the erasing magnet disposed close to the support of the display panel, the action magnetic field strengths are different. A color display method is provided in which color display is performed by scanning two or more magnetic pens or one magnetic pen having a variable operating magnetic field strength to selectively magnetize magnetic particles. .

 Hereinafter, the present invention will be described in detail.

The present invention relates to a display panel, a display device, and a display method that can be applied to an electronic blackboard or the like that requires a relatively large screen and flexibility and that can be colored, and that has different magnetization characteristics and hues or colors. Using a color display panel provided with a layer of microcapsules enclosing a dispersion of two or more magnetic particles having a particle size of 10 to 16 μm, and applying magnetic fields with different intensities to the color display panel, The method for coloring the magnetic particles used in the present invention is as follows. (I) The surface of the magnetic particles is once opaque with a white opaque pigment. After concealing the coating, a method of coloring with a desired dye, pigment or the like (Japanese Patent Laid-Open No. 60-74)
No. 41, No. 59-197047, No. 60-6952, No.
(Ii) Disperse magnetic fine particles in a binder solution, granulate the particles once by a spray drying method or the like, and coat the surface with titanium white (titanium oxide white pigment). (Iii) a method of directly dyeing ultrafine (about 200 mm or less) magnetic particles exhibiting light transmittance with a pigment or the like (US Patent No. 4,23
Nos. 8,558, 4,150,173 and 4,474,866), and (iv) a particle size 2 that reduces the degree of coloring and hiding power of the particles themselves.
A method of dispersing a spherical or elliptical spherical iron powder having a diameter of about 12 μm together with a dye and pigment in a binder resin and then pulverizing the powder (US Pat.
4,803,143), and various other methods are possible.

In the above, as the magnetic particles, iron, nickel, cobalt, magnetite, manganese ferrite, nickel ferrite, cobalt ferrite, barium ferrite, nickel zinc ferrite, copper zinc ferrite,
Particles such as manganese zinc ferrite and magnesium zinc ferrite are used. That is, these particles are colored in a desired color tone (if black, as they are), and colored magnetic particles having different magnetization characteristics can be obtained by changing the composition ratio between the magnetic particles and the binder or the dye / pigment as follows. Obtainable.

Next, a method for producing colored magnetic particles having different magnetization characteristics will be described.

(A) Iron powder having a particle diameter of 2 to 7 μm (average particle diameter of 4 μm) and a saturation magnetization of 153 emu / g obtained by spray drying iron pentacarbonyl (see US Pat. No. 4,803,143) at a wall temperature of 250 ° C. Got ready. Next, 12 g of titanium oxide, 18 g of copper phthalocyanine, and 90 g of the above-mentioned iron powder were dispersed in a solution of 0.3 g of an antioxidant and 30 g of an ethylene-vinyl acetate copolymer resin dissolved in 500 g of methylene chloride. By spray drying at 50 ° C., blue magnetic particles having a particle size of 10 to 15 μm and a saturation magnetization of 52 emu / g were obtained.

(B) Red magnetic particles having a particle diameter of 12 to 15 μm and a saturation magnetization of 50 emu / g were obtained in exactly the same manner as in (a) except that titanium oxide was replaced with zinc oxide and copper phthalocyanine was replaced with a red disperse dye. .

(C) Particle sizes of 10 to 1 were obtained in exactly the same manner as in (a) except that titanium oxide was replaced with 6 g of zinc oxide and 6 g of stearic acid, and copper phthalocyanine was replaced with 20 g of phthalocyanine green.
Green magnetic particles having a saturation magnetization of 50 emu / g at 6 μm were obtained.

(D) Except for the antioxidant, titanium oxide and copper phthalocyanine in the above (a), and further replacing the iron powder with an average particle size of 0.1.
Except for using 10 g of ferrite powder having a saturation magnetization of 81 emu / g at 2 μm, a particle diameter of 10 to 12 μm and a saturation magnetization of 20 emu / g were used.
g of black magnetic particles were obtained.

In the above description, the saturation magnetization of each magnetic particle is
It is a value measured with a magnetic balance of A / m.

Next, an example of a method for producing a microcapsule enclosing a magnetic particle dispersion and a color display panel provided with a coating layer thereof will be described.

Magna flux oil was used as a dispersion medium, and 15 wt% of titanium white was finely dispersed therein, and the red and black magnetic particles obtained in the above (b) and (d) were dispersed at a ratio of 8 wt% each. A dispersion for display was obtained. Next, the dispersion was encapsulated in a transparent film of gelatin and gum arabic by a known complex coacervation method.
It was further dried by spray drying as microcapsules of 80 to 100 μm. The dried microcapsules were dispersed in a styrene / butadiene latex at a ratio of 20% by weight, and this dispersion was applied on a 100 μm transparent polyester film to a wet thickness of about 150 μm and dried to obtain a color display panel.

〔Example〕

FIG. 1 is a sectional view showing a configuration of a color display device according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a color display panel, which is provided with a coating film of a microcapsule 12 enclosing a dispersion liquid for display and a binder 13 on a support 11, and a transparent protective layer 14 on the surface thereof. This microcapsule
Reference numeral 12 denotes a non-magnetic white pigment, titanium white 121, a low-magnetization black magnetic particle 122, and a high-magnetization red magnetic particle 123. is there. The method for producing the colored magnetic particles, the microcapsules enclosing the dispersion thereof, and the coating layer thereof is as described above.

In the color display method using the display panel 1, first, the erasing magnet 2 is moved from the back surface of the panel as shown by the arrow direction a, and the entire magnetic particles inside the microcapsules 12 are attracted and collected on the back surface side. Next, a relatively weak magnet 32 having a magnetic force of, for example, about 400 gauss is applied to the nib 31 from the panel surface side.
When the color magnetic pen 3 held at the position is moved as shown by an arrow c according to the character / graphic information, the saturation magnetization is 50 emu / g.
Only the high-magnetization red magnetic particles 123 selectively magnetized to the front side, and the low-magnetization black magnetic particles 122 remained on the back side and were concealed by the white pigment 121. Is displayed.

In addition, for example, a strong magnet 42 of about 1000 Gauss
When the magnetic pen 4 for black held at 41 is moved according to the character / graphic information, for example, as indicated by an arrow b, both magnetic particles of the high-magnetization red magnetic particles 123 and the low-magnetization black magnetic particles 122 are surfaced at this portion. Because of the electrophoresis on the side, it is black and displayed black.

Red magnetic particles in the display panel 1 in exactly the same way
When the blue magnetic particles obtained in the above (a) are used instead of 123, blue / black display can be performed, and when the green particles obtained in the above (c) are used, two colors of green / black can be displayed. .

In the above description, two magnetic pens having magnets having different generated magnetic field intensities are used. However, according to the present invention, the same operation can be performed with one magnetic pen. is there. In this case, for example, a mechanism is provided in which a magnet having a predetermined generated magnetic field strength is housed in a magnetic pen and the magnet is movable in the axial direction in the magnetic pen. The magnetic field intensity acting on the magnetic particles is the same as that of the magnetic pen 3 in FIG. 1, and when set at the second position, the magnetic field intensity acting on the magnetic particles is the same as that of the magnetic pen 4 in FIG. As the mechanism for changing the position of the magnet, for example, a mechanism similar to that used for a ballpoint pen in which a pen tip protrudes when a notch is pressed and a pen tip retreats when a release button is pressed can be used.

It is also possible to perform the same role as described above by incorporating one electromagnet in one magnetic pen and changing the applied voltage as needed through a changeover switch.

FIG. 2 is a cross-sectional view of a conventional display device shown for comparison, in which a display cell 14 is formed via a spacer 13 between sheet-like supports 11 and 12 having a transparent display side.
In 14, a liquid in which magnetic particles 142 are dispersed in a white dispersion medium 141
The magnetic display panel 1 is configured by enclosing the magnetic display panel 140. Here, brown or black particles are used as the magnetic particles 142.

In the display method using the magnetic display panel 1, the erasing magnet 2 is moved from the back surface of the magnetic display panel 1 as indicated by an arrow A 'to first collect the entire magnetic particles on the back surface side, and then the pen
By moving the magnetic pen 3 holding the display magnet 32 at the tip of 31 as shown by the arrow B ', the magnetic particles at that portion are magnetized to the surface side to display only one color. In this conventional device, the magnetic particles 142 are replaced with brown-black or black magnetic particles first, and then (a), (b),
By using the colored magnetic particles as described in (c) and (d), color display is possible, but in such a case, the display is limited to one color display. Can not.

〔The invention's effect〕

According to the present invention, by using a color display panel configured as described above using magnetophoresis as a display,
Consumables such as markers are not required, and erasure powder damage can be eliminated at the same time. Color display can be achieved by using two or more types of magnetic particles having different magnetization characteristics and hue or color tone, and the resolution can be improved by microencapsulating the dispersion of magnetic particles, enabling fine line reproduction. become. In addition, by encapsulation, a color display panel of any size from large to small can be formed, and flexibility can be obtained, so that a free shape such as roundness can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the structure of a display device according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional display device. DESCRIPTION OF SYMBOLS 1 ... Color display panel, 11 ... Support 12 ... Microcapsule, 13 ... Binder 14 ... Transparent protective layer, 121 ... Titanium white 122 ... Black magnetic particles, 123 ... Red magnetic particles 120 ... Dispersion liquid for display, 2 ... Magnet for erasing 3,4 Magnetic pen, 32,42 ... Magnet

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G09F 9/30-9/46 G02F 1/167-1/19 B43L 1/00

Claims (3)

(57) [Claims] 1. A microcapsule having a particle size of 80 to 100 μm, in which a dispersion of two or more magnetic particles having a particle size of 10 to 16 μm and having different magnetic properties and a hue or color tone is encapsulated on a nonmagnetic support. A color display panel comprising a layer. 2. A microcapsule having a particle size of 80 to 100 μm, in which a dispersion of two or more magnetic particles having a particle size of 10 to 16 μm and having different magnetization characteristics and a different hue or color tone is encapsulated on a nonmagnetic support. A color display panel provided with a coating layer, an erasing magnet arranged on the support side of the display panel for attracting and moving the entire magnetic particles to the support side, and having different magnetization characteristics and hue or color tone in the microcapsules. 2. A color magnetic display device comprising two or more magnetic pens having different action magnetic field strengths for selectively attracting and moving magnetic particles to be formed, or one magnetic pen having a variable action magnetic field strength. 3. A microcapsule having a particle size of 80 to 100 μm, in which a dispersion of two or more magnetic particles having a particle size of 10 to 16 μm and having different magnetization characteristics and a different hue or color tone is encapsulated on a nonmagnetic support. After using a color display panel provided with a coating layer, the entire magnetic particles are attracted and moved to the support side by an erasing magnet arranged close to the support side of the display panel, and then two or more magnetic field strengths different from each other are applied. A color display by scanning the magnetic pen or one magnetic pen having a variable operating magnetic field intensity to selectively magnetize the magnetic particles.