The present invention relates to a display panel using microcapsules which accommodates an electrophoretic or magnetophoretic particles, and more particularly, to a method of producing the display panel capable of arranging the microcapsules at a predetermined position on electrodes accurately and the display panel in which the microcapsules is accurately, arranged at the predetermined position on the electrodes.
In an electrophoretic display apparatus and magnetophoretic display apparatus for displaying a desired picture by using the microcapsules, each sealing colored dispersion media and the electrophoretic particles, the uniform arrangement of the microcapsules over a substrate is important on a stable display operation.
Conventionally, many methods with an object of producing a pressure sensing paper and a heat sensitive paper are proposed an methods of uniformly coating microcapsules on a plane surface.
For instance, the Japanese Patent No. 1545227 discloses a method of producing a pressure sensing copying paper by a free fall vertical curtain method as a preferable method than an air knife or blade coating method.
Also, the Japanese Patent No. 1376224 discloses a hopper typed coating apparatus as a similar method.
Further, the Japanese unexamined patent publication No. 57-27172 discloses a method to spray microcapsules coating liquid to a web (a support body) which runs continuously and to obtain a coating layer of continuous constant thickness by leveling this with a leveling device.
Moreover, the Japanese unexamined patent publication No. 62-138284 discloses a method in which a bonding layer is formed over a substrate, microcapsules layer is formed thereon, and the non-contacted microcapsules with the bonding layer are separated by gravity to form an uniform microcapsules layer of a single layer.
However, the aforementioned methods are for the purpose of obtaining the uniform layer of microcapsules, and are not sufficient methods for forming the microcapsules layer used in the display panel.
Properly placing the microcapsules at positions corresponding to electrodes or magnetic poles, configuring a display pixel in the display panel, is important to display a high definition image with uniform for each pixel. The display panel must form a uniform microcapsules layer and also control an arrangement place of each microcapsules.
Particularly, when trying to display in colors, it is necessary to place a number of microcapsules of different display colors for each pixel and control each individually. To carry out such control, the microcapsules of each display color has to be placed selectively, accurately, and with high precision, the arrangement of the microcapsules must be carried out at a higher precision.
At this point, a method of placing the microcapsules at a desired position selectively and accurately is not proposed in any method as aforementioned, and no such method exists except herein.
An object of the present invention is to provide a method of producing display panel using electrophoretic or magnetophoretic phenomenon, capable of placing microcapsules at the desired positions selectively and accurately.
Another object of the present invention is to provide a method of producing a display panel by using electrophoretic or magnetophoretic phenomenon, capable of high definition display or full color display by placing microcapsules at the desired position selectively and accurately.
Still, another object of the present invention in to provide a display panel using electrophoretic or magnetophoretic phenomenon, in which microcapsules are selectively and accurately placed at the desired positions.
Therefore, a method of producing a display panel according to the present invention, in which microcapsules each sealing dispersion media of each colored to a predetermined color and electrophoretic or magnetophoretic particles are placed over a substrate, and the desired image is displayed by changing a representation color of the microcapsules by applying an electric field or magnetic field to each microcapsules, comprises: a step of coating the microcapsules, each sealing dispersion media of each colored to a predetermined color and an electrophoretic particle or magnetophoretic particle, onto a substrate by using an optical hardening resin as a binder material; a step of fixing the microcapsules at the desired areas onto the substrate on which the microcapsules are arranged by irradiating light beam on the areas to harden the binder material and to fix the microcapsules over the substrata, and; a step of removing the non-use microcapsules and the binder material except for the hardened binder material and microcapsules fixed onto the substrate.
Preferably, electrodes poles or magnetic poles by which an electric filed or magnetic field is applied to the microcapsules are provided over the substrate, in the step of fixing the microcapsules onto the substrate, the light beam is selectively irradiated to the areas corresponding to the electrodes or magnetic poles over the substrate to fix the microcapsules to every area corresponding to the electrodes or magnetic poles provided over the substrate.
Further, in the stop of the microcapsules fixed over the substrate, the light beam is selectively irradiated at the desired areas by using a photomask.
Specifically, the processes is the steps are sequentially performed on the three types of microcapsules in which the electrophoretic particles or magnetophoretic particles each colored by one of three primary colors, and the dispersion media each colored by a color different to the three primary colors are sealed, and the three types of microcapsules being classified by the colors of the dispersion media, to arrange the three types of microcapsules over the substrate in a predetermined arrangement, to thereby produce the display panel able to display color images.
Further, the processes is the steps are sequentially performed on the three types of microcapsules in which the dispersion media each colored by one of three primary colors, and the electrophoretic particles or magnetophoretic particles each colored by a color different to the three primary colors are sealed, and the three types of microcapsules being classified by the colors of the electrophoretic particles or magnetophoretic particles, to arrange the three types of microcapsules over the substrate in a predetermined arrangement, to thereby produce the display panel able to display color images.
Further, the display panel, according to the present invention, in which microcapsules each sealing dispersion media of each colored to a predetermined color, and electrophoretic particles or magnetophoretic particles, are placed over a substrate, and a display is performed by applying an electric or magnetic field to each microcapsule, to change a presentation color of the microcapsule comprising: a pair of substrates, at least one being a transparent substrate; a plurality of microcapsules placed and fixed between the pair of substrates by an optical hardening resin binder; and electrodes or magnetic poles, provided over the substrate, for applying an electric or magnetic field to the microcapsules.
Objects and features of the present invention as mentioned above becomes more clear from the following descriptions referring to the attached drawings,
First Embodiment
First, a method which is a basic production method of the display panel for the present invention and a method for placing the microcapsules at any positions over a substrate selectively and accurately will be explained referring to
At first, as shown in
Next, as shown in
And the binder material 44 on a portion not hardened is removed by washing in water.
As a result, the microcapsules can be selectively and accurately placed at the only desired positions as shown in
In this way, in the production method, the microcapsules can be placed at the desired portions by only irradiating the light beam. Therefore, for instance, in a step of coating the microcapsules over the substrate 41, a special high accuracy position control is not necessary, and the microcapsules can be selectively, accurately and easily placed at the desired positions.
Second Embodiment
Next, the production method of the electrophoretic display panel being capable of the full color display for each pixel will be explained referring to
First, a structure of the display panel is explained.
As shown in
Note that the second electrode 13 and the upper substrate 14 side in the display panel 10 are a display surface the three types of microcapsules 21(M), 22(Y), and 23(C) are in two dimensional arrangement, orderly placed in a column direction and row direction, and are a stripe arrangement such that each two rows of the same color are sequentially repeated in the column direction continuously and the same color in continued in the row direction as shown in
The lower substrate 11 is a substrate which is configured by any insulation members supporting the display panel 10.
The first electrode 12, as shown in
A charged pigment particles is mixed and dispersed in the dispersion media in which each of the microcapsules 21, 22, and 23 is colored to the predetermined color as aforementioned mentioned above. The microcapsules 21, 22, and 23 are individually housed in the microcapsules. The display panel 10 of the present embodiment reproduces color by a subtractive color and mixture method and each dispersion media is respectively dyed to three types of cyan (C), magenta (M), and yellow (Y) as aforementioned above. Also, a charge pigment particles is dyed to white.
A structure of each of the three types of microcapsules is shown in
Also,
A state when the electric field from outside is being applied to such the microcapsules will be explained as an example of the microcapsules 21 of magenta referring to
If it is assumed that the white pigment particles 27 is charged to negative and an electric field E is applied to the microcapsules 21 in a direction as shown in
In contrast, if an electric field B in a direction as shown in
As shown in the figure, the microcapsules is placed on each electrode of the first electrode 12 formed over the lower substrate 11 being divided and microcapsules layer is formed. Note that each microcapsules is fixed between the first electrode 12 and the second electrode 13 by the binder material 15 at this time.
And an electric field applied to each microcapsules is controlled by the first electrode 12 and each microcapsules provides the color of the dispersion media or white.
Also, in the display panel 10, the microcapsules 21, 22, and 23 of color being respectively magenta (M), yellow (Y), and cyan (C) are placed so as to sequentially align each two column in the column direction repeatedly as shown in
The second electrode 13 is electrode which faces the first electrode 12 by a layer of the microcapsules and is formed over the upper substrate 14. In the present embodiment, the second electrode 13 is a transparent electrode formed so as to cover the whole of the microcapsules arranged two dimensionally with the same potential as shown in
The upper substrate 14 is a substrate at the display surface side of the display panel 10. The upper substrate 14 and the second electrode 13 are formed by a transparent member. Thus, a state of the microcapsules, i.e. a state of color display of a desired picture by the microcapsules, can be observed when the display panel 10 is seen from the upper substrate 14 side which is the display surface.
Next, a production method of the display panel 10 with the such structure is explained.
First, three types of dispersion media are formed by using the dispersion media of three colors—magenta, yellow, and cyan, and the white pigment particles.
Next, three types of microcapsules respectively including the three types of dispersion media are formed.
The diameters of the formed microcapsules are uniformized by any of screening or specific gravity separation method etc.
Then, three types of the microcapsules of the uniformized diameters are sequentially placed on each divisional electrode of the first electrode 12 formed over the lower substrate 11 in an arrangement shown in
The arrangement method of the microcapsules according to the present invention will be explained referring to
First, as shown in
Next, as shown in
The binder material 15 of the portion not hardened is removed by washing in water.
As a result, the microcapsules 23 each including cyan (C) dispersion media can be selectively and accurately placed only on the display electrode 12ccorresponding to cyan, as shown in
Thereafter, a similar procedure mentioned above is repeated, whereby the microcapsules 22 including yellow (Y) dispersion media, and the microcapsules 21 including magenta (M) dispersion media are sequentially placed at predetermined positions.
Namely, first, the microcapsules 22 including yellow (Y) dispersion media are coated on the portions where the microcapsules 23 including cyan (C) dispersion media have not already been placed, over the lower substrate 11, on which the divisional electrode 12 is formed, by using the optical hardening resin as the binder material 15.
Next, the binder material 15 is hardened to selectively irradiating the light beam at the only locations desired to place the microcapsules 22 including yellow (Y) dispersion media by using the photomask 30. The binder material 15 of the portions not hardened is removed by washing in water.
Finally, the microcapsules 21 including magenta (M) dispersion media are coated on the portions, where the microcapsules 23 including cyan (C) dispersion media and the microcapsules 22 including yellow (Y) dispersion media are not placed, over the lower substrate 11 on which the divisional electrode 12 is formed, by using the optical hardening resin as the binder material 15.
The binder material 15 is hardened to selectively irradiating the light beam at the only locations desired to coat the microcapsules 21 including magenta (M) dispersion media through the use of the photo ask 30.
At a result of this process, the microcapsules 21, 22, and 23 respectively including magenta (M), yellow (Y), and cyan (C) are respectively placed on divisional electrodes 12m, 12y, and 12a, corresponding to each color selectively and accurately, as shown in
Once the microcapsules 21, 22, and 23 are placed over the lower substrate 11, on which the first electrodes 12 are formed, the upper substrate 14 on which the second electrodes 13 are formed and the lower substrate 11 are bonded together, so as to sandwich the microcapsules 21, 22, and 23 therebetween.
In this way, the display panel 10 with a structure as shown in
As explained above, in the production method of the display panel of the present embodiment, an electrophoretic display panel capable of full color display is produced by performing a step in which the microcapsules including dispersion media of desired color are previously coated onto the whole of the substrate 11 and the microcapsules of desired color are placed at the desired position by irradiating the light beam at the portions desired to place that color's microcapsules for each color of magenta (M), yellow (Y), and cyan (C). Therefore, a high accuracy full color electrophoretic display panel can be produced, in which the microcapsules of each color is accurately placed, by a comparatively simple process without requiring a process of special accurate position control.
Note that the production method of the display panel in the present invention is not limited to the first and second embodiments as aforementioned, and various preferred modifications are available.
For instance, in the second embodiment, the production method of the display panel 10, which is capable of full color display, is described a specific panel, however, it is clear that the production method of the display panel in the present invention can be applied to a monochrome display panel.
Although the display panel of an electrophoretic system is described in the first and second embodiments as an example, a display panel of a magnetophoretic system can also be configured by a system similar to this. In that case, charged pigment particles may be changed to magnetic powder, and a voltage application means may be changed to a magnetic field application means.
Then, any means which is normally known may be used as the magnetic field application means to be comprised in the display panel. For instance, various types of magnetic heads or magnets various types may be used.
Also, three types of colors-red, green, and blue which are additional color mixture three primary colors may be used instead of the three types of colors—magenta, yellow, and cyan which are the subtractive color mixture three primary colors are used for the color of the dispersion media in the second embodiment. Also, combinations of other colors may be used.
Although the color of the charged pigment particles in white, it is preferable that the color of the charged pigment particles are black, for instance, when the additional color mixture three primary colors are used for the color of the dispersion media, and such black color may be adopted. The color of the charge pigment particles may be arbitrary determined.
Further, although the three types of microcapsules corresponding to the three primary colors are formed by changing the color of the dispersion media in the second embodiment, color of the dispersion media is identical and the three types of microcapsules corresponding to the three primary colors may be formed by changing the color of the microcapsules.
A case of a stripe arrangement in which each two columns of the same color is continuously connected in the column direction is described as an example as shown in
Furthermore, the structure of one pixel may also be defined by six microcapsules being in series in one row, as in the present embodiment, or for instance, the structure of one pixel may also be defined by three microcapsules being in series in one row or an arrangement of 2×2 of a number of four microcapsules such as having number of two microcapsules of any colors and may be arbitrarily determined.
And, the areas to place the microcapsules is limited by the photomask having the shape corresponding to the electrode or magnetic poles in the production method of the display panel according to the present invention. Therefore, aligning and placing the microcapsules orderly in the first and the second embodiments as aforementioned are not necessary if the microcapsules is small enough for the electrode. It may be better to position the microcapsules to be a layer as uniform as possible and to select the microcapsules to fix by using the photomask corresponding to the shape of the electrode or the pixel. Such the method is also falls in the scope of rights of the present invention.
As explained above, the production method of the display panel, using electrophoretic or magnetophoretic, which can selectively and accurately place the microcapsules at the desired positions, can be provided according to the present invention. Thus, the production method of the display panel, using electrophoretic or magnetophoretic capable of precision display or full color display, can be provided. Further, the display panel, using electrophoretic or magnetophoretic selectively and accurately placing the microcapsules at the desired position, can be provided.
The production method of the display panel in the present invention can be applied to a display panel using the microcapsules housing the electrophoretic or magnetophoretic particles.
Number | Date | Country | Kind |
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11-041637 | Feb 1999 | JP | national |
This application is a Continuation of prior pending application Ser. No. 09/673,372, filed Oct. 16, 2000 which is a U.S. National Stage of PCT/JP00/00976 filed Feb. 21, 2000, the contents of which are incorporated herein by reference.
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Number | Date | Country | |
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20030193473 A1 | Oct 2003 | US |
Number | Date | Country | |
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Parent | 09673372 | US | |
Child | 10434240 | US |