JP4207446B2 - Manufacturing method of multicolor display panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multicolor display panel using an electrophoretic phenomenon or a rotating phenomenon by applying an electric field to a display microcapsule in which electrophoretic particles and rotating particles are dispersed in a dispersion medium, and a method for manufacturing the same.
[0002]
[Prior art]
In recent years, with the development of information equipment, information display has been made in various forms. As a display of variable information, a CRT (cathode ray tube), a liquid crystal display, and the like are mainly used. A light-emitting display such as a liquid crystal display of the type using a CRT or a backlight makes the eyes look tired when used for a long time, and is not suitable for reading a document or the like.
[0003]
On the other hand, a liquid crystal display of a type that does not use a backlight has a problem that the darkness of the screen due to the use of a polarizing plate appears remarkably and the visibility is poor. Furthermore, the images displayed on these displays have no memory property and have the disadvantage that they disappear as soon as the electrical energy supply is stopped.
[0004]
In addition to the displays of portable information devices such as so-called PDAs (Personal Digital Assistants) and electronic books that will become more widespread in the future, printed materials such as newspapers, books, magazines, and posters, and output from paper to printers, etc. When replacing hard copy with display, it is necessary to keep eyes on eyes even when used for a long period of time, with good visibility, low power consumption, and memory characteristics of images. It is believed that there is.
[0005]
Conventionally, electrophoretic display devices and two-color ball display devices are known as non-light-emitting displays that satisfy these requirements to some extent.
[0006]
A large number of electrophoretic display devices using an electrophoretic phenomenon by applying an electric field of electrophoretic particles dispersed in a dispersion medium have been reported as disclosed in Japanese Patent Publication No. 50-15115.
[0007]
However, although the conventional technique can perform monochromatic display, it has been difficult to perform multicolor display. This is because it is difficult to arrange multicolor electrophoretic particles on predetermined pixels.
[0008]
For this reason, a structure in which a color filter is superimposed on monochromatic electrophoretic particles is also known.
[0009]
In this structure, the color transmitted through the color filter is scattered in the microcapsule and travels as stray light to pixels of other color filters at a constant rate, so that the amount of light is reduced, leading to a decrease in contrast.
[0010]
[Problems to be solved by the invention]
The present invention has been made to solve such problems, and the object of the present invention is to reliably place a plurality of display microcapsules whose optical reflection characteristics are changed by application of an electric field at a desired position. An object of the present invention is to provide a display panel capable of high-definition and high-quality multiple colors and color display and a method for manufacturing the same.
[0019]
[Means for Solving the Problems]
The invention according to claim 1 of the present invention is
(A) providing a transparent conductive first electrode on the transparent substrate of the front substrate, and providing a photosensitive conductive layer on the first electrode;
(B) applying a photopolymer on the photosensitive conductive layer;
(C) forming a cell frame having a shape in which a predetermined number of display microcapsules are accommodated in the photopolymer layer using a lithography method;
(D) The front substrate is immersed in an electrodeposition liquid containing a microcapsule for display containing at least a first color pigment or dye and a dispersion medium, a voltage is applied through the first electrode, and electrodeposition of the cells is performed. Irradiating light only through the mask plate to the part to be processed, and electrodepositing the display microcapsule in a predetermined cell;
(E) Similarly for the second and third colors, (d) and (e) are repeated, and at least two or more required colors are repeated in all the cells,
(F) The rear substrate having the second electrode, which is a matrix electrode, is laminated and integrated so as to sandwich the cell so that the positional relationship between the cell on which the display microcapsules are electrodeposited and the matrix electrode correspond to each other. Process,
Is a manufacturing method of a multicolor display panel.
[0020]
According to a second aspect of the present invention, in the method for manufacturing a display panel according to the first aspect , the white color and the pigment are contained in the photopolymer.
[0021]
The invention according to claim 3 is the method for manufacturing a display panel according to claim 1 , characterized in that the photopolymer contains a black dye and a pigment.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0023]
In the present embodiment, the present invention will be described by exemplifying a display panel capable of color display by reproducing colors using additive primary colors (R, G, B) and a manufacturing method thereof.
[0024]
First, the multicolor display panel according to the present invention will be described. FIG. 1 is a cross-sectional view showing the structure of a multicolor display panel using three additional primary colors of red (R), green (G), and blue (B).
[0025]
The display panel shown in FIG. 1 has a transparent conductive first electrode (1b) made of indium oxide-tin oxide (ITO), tin-antimony, indium tin oxide, tin oxide, etc. on a transparent substrate (1a). Photosensitivity of photoconductive compounds such as cadmium sulfide, germanium, zinc oxide, amorphous selenium, amorphous silico, titanyl phthalocyanine, polyvinyl carbazole and the like which show conductivity when light is irradiated onto the first electrode (1b). The front substrate (1) on which the conductive conductive layer (1c) is formed and the back substrate (3) on which the second electrode (3b) which is a matrix electrode is formed on the base material (3a) are arranged opposite to each other. In the meantime, red (R), green (G), blue (B) colored electrophoretic particles 11, 12, and 13 and black electrophoretic particles (14) are encapsulated in a transparent dispersion medium, respectively. Ma The black capsule (110), the G color display microcapsule (120), and the B color display microcapsule (130) are held in the polymer resin cell (2) layer and arranged in a pattern at a desired position. .
The first electrode and the second electrode are called electric field applying means.
[0026]
The second electrode (3b) formed on the back substrate (3) is provided between a matrix electrode formed corresponding to the display microcapsules arranged in a pattern at a desired position and a matrix electrode (not shown). A switching element for displaying an image is provided.
[0027]
The first electrode (1b) formed on the front substrate (1) is provided so as to cover the entire surface with the same potential.
[0028]
As shown in FIG. 1, the multicolor display panel has display microcapsules 110 and 120 whose optical reflection characteristics change to red (R), green (G), blue (B), and black, respectively, by applying an electric field. , 130 are arranged adjacently so as to be repeatedly arranged in order, and by controlling the electric field applied to each pattern, color display by additive color mixture becomes possible.
[0029]
The principle of multicolor display using the display microcapsules in which the electrophoretic particles are enclosed is shown in FIG. That is, as shown in FIG. 2A, this display microcapsule (200) has a capsule shell (202) made of acrylic resin such as polymethyl methacrylate and polyethyl methacrylate, urea resin, gum arabic, etc. In addition, colored particles (201) made of an R color pigment and black particles (204) made of carbon black are dispersed and encapsulated in a highly viscous dispersion medium (203) such as silicone oil. In this case, the colored particles are made to have a positive charge, and the black particles are made to have a negative charge.
[0030]
When an electric field is applied to the display microcapsule (200) so that the first electrode of the front substrate (1) is a negative electrode and the second electrode of the rear substrate (3) is a positive electrode, as shown in FIG. The colored particles (201) are electrophoresed on the front substrate (1) side, and the black particles (204) are electrophoresed on the back substrate (3) side. Therefore, the viewer will observe the R color of the colored particles.
Conversely, when an electric field is applied so that the first electrode of the front substrate (1) is a positive electrode and the second electrode of the rear substrate (3) is a negative electrode, the black particles (204) are front surfaces as shown in FIG. On the substrate (1) side, the colored particles (201) are electrophoresed on the back substrate (3) side. Therefore, the viewer will observe the black black particles.
Therefore, an image can be displayed by applying an electric field to each pixel based on image data.
[0031]
In the case of the display microcapsule (300) in which rotating particles in which one surface of the hemisphere is colored with red (R), green (G), and blue (B) and the other hemisphere is made black are included for each pixel. When an electric field is applied, the rotating particles rotate and an image can be displayed.
[0032]
For example, as shown in FIG. 3A, one surface (301) of the hemisphere is R color, one surface (302) of the other hemisphere is black, the R color side of the rotating particles is the positive electrode, and the black side is the negative electrode. When the electric field is applied so that the first electrode of the front substrate (1) is a negative electrode and the second electrode of the rear substrate (3) is a positive electrode, the R color of the rotating particles is as shown in FIG. Are oriented so that the black side faces the front substrate (1) side and the black side faces the rear substrate (3) side. Therefore, the viewer will observe the R color.
Conversely, when an electric field is applied so that the first electrode of the front substrate (1) is the positive electrode and the second electrode of the rear substrate (3) is the negative electrode, the black color of the rotating particles is on the front substrate (1) side, and the R color is Oriented to face the back substrate (3) side. Therefore, the viewer will observe black.
Therefore, an image can be displayed by applying an electric field to each pixel based on image data.
[0033]
Further, in the inventions according to claims 3 to 6, when color display is performed with three additive primary colors, when the three colors overlap, it becomes white, and black is difficult to display. In the case of displaying in color, it is indicated that it is preferable to make the other white because it is black when three colors overlap and it is difficult to display white.
[0034]
According to the eighth aspect of the present invention, the cell frame is made black to improve the black margin so that the cell frame has a black matrix function like a liquid crystal display. Further, the invention according to claim 7 is to improve the sharpness of white when white is dull and displayed.
[0035]
Next, a method for manufacturing such a multicolor display panel will be described.
A multicolor display panel using a transparent dispersion medium and display microcapsules using colored particles and black particles of red (R), green (G), and blue (B) will be described as an example.
[0036]
As the transparent dispersion medium used for the display microcapsules, for example, a solvent obtained by mixing silicone oil, aliphatic hydrocarbon, aromatic hydrocarbon, alicyclic hydrocarbon, or the like alone or appropriately can be used.
[0037]
As the colored particles, organic pigments such as known azo pigments and phthalocyanine pigments, various inorganic pigments, metal powders, fine particles such as glass or resin, and composites thereof are used.
[0038]
As the black particles, an inorganic pigment such as carbon black, a fine powder such as glass or resin, and a composite of these are used.
[0039]
If necessary, the dispersion stability in the dispersion can be improved by adding various surfactants, dispersants and the like to the surface of the particles.
[0040]
When an electric field is applied to a dispersion system in which colored particles and black particles are dispersed in these transparent dispersion media to change the display color, the colored particles and black particles are charged to charges having opposite polarities. Even if charged to the same charge, by providing a sufficient difference in charge amount, color display similar to that of a dispersion system in which black particles are dispersed in a colored dispersion medium can be achieved.
[0041]
Three types of dispersions in which these R color particles and black particles, G color particles and black particles, B color particles and black particles are dispersed in a transparent dispersion medium are each a phase separation method such as a composite coacervation method, Display microcapsules are prepared using a known method such as an interfacial polymerization method, an in-situ method, a solution dispersion cooling method, or the like.
These display microcapsules control the diameter distribution of the prepared display microcapsules by an arbitrary method such as sieving or specific gravity separation as required.
[0042]
These three types of display microcapsules are each dispersed in a predetermined electrolytic solution to form an electrodeposition solution.
[0043]
Next, a method for forming the transparent conductive first electrode (1b), the photosensitive conductive layer (1c) and the cell (2) on the base material (1a) of the front substrate (1) will be described.
As the base material (1a) of the front substrate made of a transparent member, a plastic film base material such as polyethylene terephthalate, polycarbonate, and polyethersulfone can be suitably used in addition to the glass base material.
[0044]
As the transparent first electrode (1b) formed on the base material (1a) of the front substrate (1), a transparent first electrode such as ITO (Indium Tin Oxide) is used. If necessary, a water vapor prevention layer, an antiglare layer, and a hard coat layer can be provided on either side of the substrate.
[0045]
A photosensitive conductive layer (1c) is provided on the first electrode (1b). The photosensitive conductive layer (1c) becomes conductive when exposed to light, and inorganic materials such as cadmium sulfide, lead sulfide, and selenium, and organic materials such as phthalocyanine, perylene, and azo are used.
[0046]
A cell (2) layer is formed on the photosensitive conductive layer (1c). The cell (2) layer is formed using a lithography method as shown in FIG.
On the photosensitive conductive layer (1c), a negative photoresist (4) material is applied, and a mask plate (5) on which a cell pattern is formed is brought into close contact with the material to be exposed. Thereafter, the non-photocured area is removed by development, and the photocured portion is formed as a cell frame (4a). (See FIGS. 4A to 4C)
[0047]
A negative photoresist is a pattern that uses a photopolymerization or photocrosslinking reaction by suitably blending a photosensitive monomer, a photopolymerization initiator, or the like into a resin component such as an acrylic resin having an acidic functional group such as a carboxyl group. Examples of the photosensitive monomer include acrylic acid esters such as N-vinyl pyrrolidone, ethyl acrylate and propyl acrylate, methacrylic acid esters such as ethyl methacrylate and propyl methacrylate, tetrahydrofurfuryl methacrylate, and caprolactone modified products thereof. Derivatives, styrene, α-methylstyrene, acrylic acid and the like, and mixtures thereof.
[0048]
The amount used is desirably 1 to 100 parts by weight, more preferably 5 to 80 parts by weight based on 100 parts by weight of the resin component.
[0049]
Examples of the photopolymerization initiator include benzoin such as benzoin, benzoin methyl ether and benzoin ethyl ether and alkyl ethers thereof; acetophenones such as acetophenone and 2,2-dimethoxy-2-phenylacetophenone; methyl anthraquinone and 2-ethyl Anthraquinones such as anthraquinone; thioxanthones such as thioxanthone and 2,4-diethylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; benzophenones such as benzophenone and 4,4-bismethylaminobenzophenone and azo compounds, triazines A compound, an acyl phosphine oxide compound, etc. can be used suitably individually or in mixture of 2 or more types. The amount used is desirably 0.5 to 50 parts by weight, more preferably 1 to 30 parts by weight, based on 100 parts by weight of the photosensitive monomer.
[0050]
Moreover, a solvent component can be suitably mix | blended as needed. The solvent can be arbitrarily used depending on compatibility with the resin component and the like, and the blending amount is 5 to 400 parts by weight, more preferably 10 to 200 parts by weight with respect to 100 parts by weight of the resin component. is there.
[0051]
A first electrode (1b), a photosensitive conductive layer (1c), and a cell (2) layer are formed on the transparent substrate (1a), and an electrodeposition liquid in which display microcapsules are dispersed is used on the front substrate (1). The electrodeposition process is performed, and display microcapsules are added for each color.
[0052]
Here, a display microcapsule dispersed in 18 MΩ · cm ultrapure water is used as the electrodeposition liquid, and the display microcapsule is positively charged in pure water.
[0053]
FIG. 5 is a schematic view of an apparatus for electrodepositing the display microcapsules in the cells of the front substrate, and FIG. 6 is a diagram for explaining the electrodeposition method.
[0054]
First, in order to electrodeposit the R color microcapsule of the first color on a predetermined cell, a voltage is applied to the first electrode of the front substrate (1) via a connector. First, the front substrate (1) is immersed in the electrodeposition liquid (8) in which the first color R-display microcapsules are dispersed. The counter electrode (7) is also already installed in the electrodeposition liquid (8). A carbon electrode was used as the counter electrode (7). In addition, insoluble electrodes such as stainless steel and titanium can be used.
[0055]
As shown in FIG. 5, the electrolytic cell (10) is irradiated with light from the outside of the cell, and the light transmitted through the mask plate (6, 6r) having a pattern in which only the R display cell transmits light is front surface. A predetermined part of the cell (2) is illuminated through the substrate (1). The photosensitive layer of the cell exposed to light receives light and has electrical conductivity. On the other hand, no current flows in the photosensitive layer where light does not strike.
[0056]
Here, a voltage is applied between the front substrate (1) and the counter electrode (7). By setting the front substrate (1) to a negative potential, the positively charged R display microcapsules (110) move and are electrodeposited on the irradiated X portion. The voltage can be applied by selecting DC or pulse. (See FIGS. 6A and 6B).
[0057]
After a sufficient energization time, the front substrate (1) is taken out of the electrolytic cell (10) and washed with pure water.
[0058]
Next, the same operation as the electrodeposition of the R color display microcapsule (110) is performed for the G color display microcapsule (120) and the B color display microcapsule (130). The red (R), green (G), and blue (B) mask plates are each adjusted by an alignment device.
FIG. 6C shows that the G color display microcapsules (120) are electrodeposited using a G color electrodeposition mask plate (6g).
There is no regulation on the order of electrodeposition. Other colors can also be used by the same operation.
[0059]
And the display panel of the structure of FIG. 1 can be manufactured by bonding back substrate (3) in which the 2nd electrode (3b) was formed on these microcapsule pattern layers for a display.
[0060]
As described above, by patterning a plurality of display microcapsules having different optical reflection characteristics that change due to application of an electric field by the electrodeposition method, each display microcapsule is accurately arranged at a desired position. As a result, the electric field applying means on the substrate can be accurately arranged at a desired position.
[0061]
As shown in the present embodiment, each of the dispersion media is colored in three primary colors and the electrophoretic particles are black, and the three types of display microcapsules are transparent. Three types of microcapsules for display composed of colored particles colored in three primary colors and black particles can be accurately arranged to be repeatedly arranged in order as a display unit for each pixel, with high definition capable of color display for each pixel. High-quality display panels can be manufactured.
[0062]
The display panel manufacturing method of the present invention is not limited to the present embodiment, and various suitable modifications can be made. For example, in the embodiment of the present invention, a method for manufacturing a display panel capable of color display has been exemplified. For example, two types of display microcapsules whose optical reflection characteristics change between black and white and red and white. By using the electrodeposition method, patterning, and placing it at the desired position, the display colors are black, red, and white only, but a higher definition display than when three types of display microcapsules are used. Panels can be manufactured.
[0063]
Further, in the present embodiment, three primary colors of additive color mixture using three types of display microcapsules whose optical reflection characteristics are changed to red (R), green (G), blue (B), and black are used. Although the case has been illustrated, display microcapsules having optical reflection characteristics of the three primary colors of subtractive color yellow (Y), magenta (M), and cyan (C) can also be used. Also, any other color combination may be used. In the case of using a display microcapsule having optical reflection characteristics of three additive primary colors, red (R), green (G), and blue (B), the other optical reflection characteristic is preferably black. Color can also be used.
[0064]
Furthermore, there is no particular limitation as long as the number of display microcapsules held in each pattern is one or more, and a plurality of display microcapsules having a small diameter may be used.
[0065]
【The invention's effect】
As described above, if the display panel and the manufacturing method thereof according to the present invention are used, two or more kinds of display microcapsules having different optical reflection characteristics that change by application of an electric field are patterned by an electrodeposition method. It is possible to provide a display panel that can be reliably installed at the position, capable of high-definition and high-quality multiple colors and color display, and a manufacturing method thereof.
[Brief description of the drawings]
FIG. 1 is a cross-sectional configuration diagram of a display panel according to an embodiment of the present invention.
FIGS. 2A and 2B are diagrams illustrating a display method using electrophoretic particles, where FIG. 2A shows a display microcapsule, and FIGS. 2B and 2C show states when an electric field is applied.
3A and 3B are diagrams illustrating a display method using rotating particles, in which FIG. 3A shows a display microcapsule, and FIG. 3B shows a state when an electric field is applied.
FIGS. 4A and 4B illustrate a process of forming a cell layer on a substrate. FIG. 4A shows a cell layer formed by applying a photopolymer to the substrate, FIG. 4B exposing through a mask plate, and FIG. 4C developing. It is sectional drawing which shows each performed state.
FIG. 5 is a schematic external view of an apparatus for electrodeposition of display microcapsules.
6A and 6B illustrate a process of electrodepositing display microcapsules on a cell layer. FIG. 6A shows a process of moving an R display microcapsule through an R-color electrodeposition mask plate while applying an electric field, (B) shows the state where the R color display microcapsules are electrodeposited in the predetermined cells, and (c) shows the state where the B color display microcapsules are electrodeposited in the predetermined cells. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Front substrate 1a ... Transparent base material 1b ... 1st electrode 1c ... Photosensitive conductive layer 2 ... Cell 2a ... Cell frame 3 ... Back substrate 3a ... Base material 3b ... 2nd electrode 4 ... Photopolymer 4a ... Photocuring part ( Cell frame)
5 ... cell forming mask plate 6 ... electrodeposition mask plate 6r ... R color electrodeposition mask plate 6g ... G color electrodeposition mask plate 7 ... counter electrode 8 ... electrodeposition solution 10 ... electrolytic cell 11 ... R color particles 12 ... G color Particle 13 ... B color particle 14 ... Black particle 100 ... Multicolor display panel 110 ... R color display microcapsule 120 ... G color display microcapsule 130 ... B color display microcapsule 200 ... Electrophoretic particles are enclosed Microcapsule 201 ... Colored particle 202 ... Capsule shell 203 ... Dispersion medium 204 ... Black particle 300 ... Microcapsule 301 in which rotating particles are enclosed ... Colored hemisphere 302 ... Blacked hemisphere

Claims (3)

(A) providing a transparent conductive first electrode on the transparent substrate of the front substrate, and providing a photosensitive conductive layer on the first electrode;
(B) applying a photopolymer on the photosensitive conductive layer;
(C) forming a cell frame having a shape in which a predetermined number of display microcapsules are accommodated in the photopolymer layer using a lithography method;
(D) The front substrate is immersed in an electrodeposition liquid containing a microcapsule for display containing at least a first color pigment or dye and a dispersion medium, a voltage is applied through the first electrode, and electrodeposition of the cells is performed. Irradiating light only through the mask plate to the part to be processed, and electrodepositing the display microcapsule in a predetermined cell;
(E) Similarly for the second and third colors, (d) and (e) are repeated, and at least two or more required colors are repeated in all the cells,
(F) The rear substrate having the second electrode, which is a matrix electrode, is laminated and integrated so as to sandwich the cell so that the positional relationship between the cell on which the display microcapsules are electrodeposited and the matrix electrode correspond to each other. Process,
A method for producing a multicolor display panel comprising: 2. The method for producing a display panel according to claim 1, wherein the photopolymer contains a white dye and a pigment. 2. The method for producing a display panel according to claim 1, wherein the photopolymer contains a black dye and a pigment.

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