JP5512367B2 - Color display device and manufacturing method thereof - Google Patents

Description

  The present invention relates to an invention of a color display device (for example, color electronic paper or a color pressure-sensitive switch product) that can be used for electronic devices such as mobile phones and PDAs, communication devices, electronic books, and signage.

Conventionally, as an invention of a color display device, a method of laminating an electrophoretic layer and a color filter layer (Patent Document 2) or the like has been studied, but this is to color-display by blocking pixels of unnecessary colors. As a result, there was a problem that the color was dim and the screen was darkened. Therefore, recently, as a method for solving this problem, a method of changing the color of each pixel itself by changing the driving potential by using a photonic crystal material (Patent Document 1) has been studied. For example, as shown in FIG. 9, a display device substrate 90, a patterned driver layer 8 in the pixel 50 units on one side of the display device substrate 90, said driver layer 8 of the display device substrate 90 A potential change caused by driving the patterns 80 and 81 of the driver layer 8 by having a structure including a layer 110 made of a photonic crystal material formed entirely on a surface opposite to the formed surface. As a result, the thickness of the layer 110 made of the photonic crystal material changes, and the color display device 200 is obtained in which the refractive index changes and the color of the reflected light reversibly changes in units of 50 pixels. And in the Example of patent document 1, about the layer which consists of polyferrocenylsilane which is an example of a photonic crystal material, it is disclosed that one pixel 50 changes to blue, green, and red according to the change of electric potential. ing. In addition to the change in potential, such a photonic crystal material has a layer 110 made of the photonic crystal material whose thickness changes depending on the change in pressure. It is also possible to obtain a color display device 200 whose color changes reversibly in units of 50 pixels.

JP-T-2006-504984 JP 2003-280044 A

  However, the method of changing the color of each pixel itself by changing the driving potential does not cause a problem when displaying the entire screen with a single solid color, but when driving a full color display, each pixel is driven. Alternatively, not only the loaded potential, but also the influence of the potential driven on the surrounding pixels, each pixel does not necessarily have the desired color, and the color of each pixel changes over time. There was a problem. Similarly, the method of changing the color of each pixel itself by changing the pressure applied does not cause a problem when a single color solid is displayed by applying pressure to the entire screen, but the pressure is applied to a part of the screen. When applying color to display the color of that part, not only the part where pressure is applied, but also the surrounding part is affected by the applied pressure, so the color is changed only to the desired part. There is a problem that the color of each pixel changes over time.

The present inventors solved the above-mentioned problems by the following invention. That is, according to the first aspect of the present invention, a display device substrate, and a driver layer that is patterned in a pixel unit on one side of the display device substrate, said driver layer of the display device substrate has been formed the surface Or a photonic crystal material layer formed on the opposite side, and the thickness of the layer made of the photonic crystal material changes due to a change in potential generated by driving each pattern of the driver layer , and the refractive index changes. A color display device in which the color of reflected light reversibly changes on a pixel-by-pixel basis , wherein the photonic crystal material layer is divided into islands having a size equal to or smaller than the pixel size. I will provide a. According to a second aspect of the present invention, there is provided the color display device according to the first aspect, wherein the size of the divided island is 1/4 to 1/1000 of the pixel size.

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According to a third aspect of the present invention, there is provided the color display device according to any one of the first and second aspects, wherein the islands configured to be separated are completely separated and independent. According to a fourth aspect of the present invention, there is provided the color display device according to any one of the first to third aspects, wherein the islands configured to be separated are partially connected. Moreover, according to the 5th aspect of this invention, the brightness of the said display device base material is 0-4 in the Munsell color system based on JIS-Z-8721: 1993, The 1st- 4th characterized by the above-mentioned. A color display device according to any of the aspects is provided.

According to the sixth aspect of the present invention, there is provided a method of manufacturing the color display device according to any one of the first to fifth aspects, wherein the method of dividing the photonic crystal material layer into islands is by nanoimprint processing. A method for manufacturing a color display device is provided. According to a seventh aspect of the present invention, there is provided a method for manufacturing the color display device according to any one of the first to fifth aspects, wherein the method of dividing the photonic crystal material layer into islands is a color by photolithography. A method for manufacturing a display device is provided.

According to an eighth aspect of the present invention, there is provided a method for manufacturing the color display device according to any one of the first to seventh aspects, wherein the island-shaped photonic crystal material layer is displayed by a transfer method. A method for producing a color display device formed on a device substrate is provided.

The color display device according to the first aspect includes a display device base material, a driver layer patterned in pixel units on one side of the display device base material, and the surface of the display device base material on which the driver layer is formed or the opposite side. A photonic crystal material layer formed on the surface, and a color display device in which the color of the photonic crystal material layer reversibly changes pixel by pixel due to a change in potential generated by driving each pattern of the driver layer. The photonic crystal material layer is divided into islands having a size equal to or smaller than a pixel size. Therefore, the peripheral pixels of each pixel are hardly affected by the driven potential, and there is an effect that a desired color can be obtained even when full color display is performed. In addition, the color of each pixel can be prevented from changing over time.

The color display device according to the second aspect is characterized in that a size of the divided island is 1/4 to 1/1000 of a pixel size. Accordingly, since the size of each of the divided islands of the photonic crystal material layer is considerably smaller than the size of each pixel, a desired layer can be obtained without alignment between the driver layer and the photonic crystal material layer. There is an effect that color display is possible.

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Moreover, the color display device of the present invention according to the fifth aspect is characterized in that the brightness of the display device substrate is 0 to 4 in the Munsell color system based on JIS-Z-8721: 1993. Therefore, there is an effect that the color of the photonic crystal material layer can be developed more clearly.

In addition, the color display device manufacturing method according to the sixth aspect and the seventh aspect is characterized in that the method of dividing the photonic crystal material layer into islands is nanoimprinting or photolithography. Therefore, since the size of the island of the photonic crystal material layer can be processed to be considerably small, there is an effect that a finer color display device can be obtained.

Further, the color display device manufacturing method according to the eighth aspect is characterized in that the island-shaped photonic crystal material layer is formed on the display device substrate by a transfer method. That is, a transfer sheet is prepared by sequentially forming a photonic crystal material layer and an island-shaped adhesive layer on a substrate sheet having releasability, and the transfer sheet is laminated on a display device substrate, and then released from the mold The base sheet having the property is peeled to form an island-shaped adhesive layer and an island-patterned photonic crystal material layer on the display device substrate. Therefore, the photonic crystal material layer can be formed on a base sheet having releasability by roll-to-roll, and can be easily patterned in an island shape, so that the productivity is greatly improved.

It is the schematic perspective view which showed the structural example of the color display device of this invention, and shows the example of the structure in which the layer from which a color changes is formed in the island form which became completely separated and independent. It is the schematic sectional drawing which cut | disconnected FIG. 1 by the AA line. It is the schematic sectional drawing which showed the structural example of the color display device of this invention, and shows the example of the structure where a part of layer from which a color changes connects and is formed in island shape. It is a schematic sectional drawing which showed the structural example of the color display device of this invention, and shows the example of the structure where each island of the layer from which a color changes, and the pattern of a driver layer have produced position shift. FIG. 2 is a schematic cross-sectional view showing an example of a manufacturing method of the color display device shown in FIG. 1, in which a photonic crystal material layer and an island-shaped adhesive layer are sequentially formed on a substrate sheet having releasability The process which created is shown. FIG. 2 is a schematic cross-sectional view showing an example of a manufacturing method of the color display device shown in FIG. 1, showing a step in which a part of the photonic crystal material layer is removed by etching using the adhesive layer as a resist. It is the schematic sectional drawing which showed an example of the manufacturing method of the color display device shown in FIG. 1, and shows the process which laminated | stacked the transfer sheet on the display device base material. FIG. 2 is a schematic cross-sectional view showing an example of a manufacturing method of the color display device shown in FIG. 1, in which an adhesive layer and islands patterned on islands on a display device substrate by peeling a substrate sheet having transfer releasability A process of transferring and forming a photonic crystal material layer patterned in a shape is shown. It is the schematic sectional drawing which showed the structural example of the color display device of a prior art .

The color display device of the present invention will be described below. In the color display device 1 shown in FIG. 1, the driver layer 8 is pattern-formed on the back surface of the display device substrate 90 in units of 50 pixels, and the surface is divided into islands having a size equal to or smaller than each pixel 50 by grooves 28. A crystalline material layer 10 is formed. The size of each pixel 50 is determined by the patterns 80 and 81 of the driver layer 8. FIG. 2 is a schematic sectional view of the color display device 1 taken along line AA. In FIG. 2, the photonic crystal material layer 10 is divided into islands 15, 16, 17, 18, 19, and 20 by grooves 28, and the islands 15, 16, 17, and 18 are included in one pixel.

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Examples of the display device substrate 90 include various glasses such as silicate glass, acrylic glass, chalcogen glass, and organic glass, and various plastic films such as polyester, urethane, acrylic, and vinyl chloride. It does not matter. Further, it may be transparent or colored. However, when the display device base material 90 sees the photonic crystal material layer 10 behind the driver layer 8 and the display device base material 90 from the driver layer 8 side to be described later, the display device base material 90 needs to be transparent. When viewed from the photonic crystal material layer 10 side, it is desirable that the material is colored with a concealing black or the like . The color of the photonic crystal material layer is set to black when there is a base material having a lightness of 0 to 4 in the Munsell color system based on JIS-Z-8721: 1993 behind the photonic crystal material layer 10. This is because the effect of being able to develop the color more clearly is obtained.

Examples of the driver layer 8 include a thin film transistor (TFT) and a metal insulator metal (MIM) made of an inorganic material such as amorphous silicon or an organic material such as pentacene, but other materials may also be used. When the driver layer 8 is made of a transparent material (for example, a transparent oxide semiconductor material such as zinc oxide, tin oxide, indium oxide, copper oxide, nickel oxide), the front surface of the photonic crystal material layer 10 The photonic crystal material layer 10 behind can be seen through the driver layer 8.

  Examples of the material of the photonic crystal material layer 10 whose color is changed by a change in potential include polyferrocenylsilane materials such as the substituted sila-1-ferrocenophan of Patent Document 1 described above. Other materials may be used as long as they change. As a product of a specific material whose color changes due to such a potential change, there is P-ink of OPALUX. Examples of the material of the photonic crystal material layer 210 whose color changes with a change in pressure include various synthetic rubber materials such as acrylic, silicon, and urethane resins, but other materials can be used as long as the color changes with a change in pressure. It may be a material. Examples of specific materials for which the color changes due to such a pressure change include OPALUX Elast-ink ID, Elast-ink XR, Color Sketch, Press 2, Peel & Reveal.

As a method for forming the photonic crystal material layer 10 , in addition to a normal printing method such as an offset printing method, a gravure printing method, a screen printing method, a method using various coaters, a spin coat, a coating, a vacuum deposition method, a sputtering method, an ion It is good to use a method such as plating or plating. The thickness of the photonic crystal material layer 10 is preferably formed in the range of 0.05 to 200 μm. This is because when the thickness of the photonic crystal material layer 10 is less than 0.05 μm, defects such as pinholes tend to occur, and even if the thickness is increased to more than 200 μm, the effect is not improved and productivity is only lowered. . In the drawing, the photonic crystal material layer 10 is provided on the surface of the display device substrate 90 opposite to the surface on which the driver layer 8 is formed, but the photonic crystal material layer 10 is displayed. You may provide in the surface in which the driver layer 8 of the device base material 90 was formed.

Then, a groove 28 is formed in the photonic crystal material layer 10 whose color changes according to a change in potential, and in the cross-sectional view shown in FIG. 2, islands 15, 16, 17, 18, 19 less than the size of each pixel 50 are formed. , 20 are divided into independent structures. With this structure, when the driver layer 8 is driven to change the potential, the photonic crystal material layer 10 on the islands 15, 16, 17, and 18 has only a change in potential generated in the pattern 80. The influence of the potential change caused by the adjacent pattern 81 is blocked by the groove 28.

  Therefore, the photonic crystal material layer 10 of the islands 15, 16, 17, and 18 is generated in the pattern 80 even if the change in potential generated in the pattern 80 is significantly different from the change in potential generated in the adjacent pattern 81. The color changes only by a change in potential, and the color of the photonic crystal material layer 10 on the islands 19 and 20 changes only by a change in potential generated in the pattern 81. As a result, each pixel 50 can be independently changed to a desired color, and if this is applied to the entire screen, the color display device 1 capable of full color control can be obtained.

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2 and 11 show an example in which the islands 15, 16, 17, 18 , 19, and 20 are completely separated and independently formed, but a partially connected structure ( 3) are also included in the scope of rights. That is, the sense that if the island 15,16,17,18,19,20 separated so as not to undergo a change in potential occurring next to the pattern 81 by the groove 28 is formed, the other shape is not limited It is. In the case of a partially connected island structure as shown in FIG. 3, when a protective layer or the like is formed on the photonic crystal material layers 10 and 210 and the adhesion between the protective layer and the display device substrates 90 and 290 is poor 1 has the advantage that the photonic crystal material layers 10 and 210 serve as an anchor layer that helps the adhesion thereof.

The size (length) of each island is desirably 1/4 or smaller than the size (length) of the pixel 50 as shown in FIGS. The reason is that if the a pattern 80 of the island 15, 16, 17, 18 and the driver layer 8 as shown in FIG. 4 was prepared misaligned, the island 18 is the potential of the pattern 80 of the driver layer 8 Although not only the change but also the influence of the change in the potential of the pattern 81, the desired color cannot be controlled, but the photonic crystal material layer 10 on the islands 15, 16, and 17 only changes the potential generated in the pattern 80. This is because the color can be changed and controlled to a desired color, so that one pixel 50 can be controlled to a desired color within an allowable range.

In other words, by making the size of each island 1/4 or smaller than the size of the pixel 50, the desired color display can be achieved without aligning the driver layer 8 and the photonic crystal material layer 10. Because there is. However, the reason why the size of each island is made smaller than 1/1000 of the size of the pixel 50 is that there is a problem in productivity because it is necessary to form so many grooves 28 and to reduce the width of each groove. The effect will not increase. Therefore, the size of the island is preferably ¼ to 1/1000 of the size of the pixel 50.

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The thickness of the photonic crystal material layer 10 is preferably formed within a range of 0.1 to 200 μm. This is because defects such as pinholes tend to occur when the thickness of the color-changing layer 10 is less than 0.1 μm, and even if the thickness is greater than 200 μm, the effect does not increase and productivity only decreases. .

The width of the groove 28 is preferably set in the range of 0.02 to 200 μm. If the width of the grooves 28 and 228 is larger than 200 μm, the grooves 28 are visible to the viewer, which is not preferable in terms of appearance design. If the width of the grooves 28 is less than 0.02 μm, there is a problem in productivity and the effect is improved. Because there is no. The depth of the groove 28 is preferably in the range of ¼ to 1/1 of the thickness of the photonic crystal material layer 10 . This is because if there is a division less than ¼ of the thickness of the photonic crystal material layer 10, it is likely to be affected by the potential change occurring in the adjacent pattern 81 .

Examples of a method of forming grooves 28 and 228 in the photonic crystal material layer 10 and dividing the islands 15 , 16 , 17 , 18, 19, and 20 include nanoimprint processing and photolithography. This method may be used.

Specifically, a nanoimprint mold having a shape obtained by inverting the shape of the desired groove 28 and islands 15 , 16 , 17 , 18, 19 , and 20 is created, and set on the photonic crystal material layer 10. Or it forms by what is called normal temperature nanoimprint method or the thermal nanoimprint method which presses with a fixed pressure, adding heat. Alternatively, if the photonic crystal material layer 10 can be made into an ultraviolet curable type, it may be formed by a so-called UV nanoimprint method in which the photonic crystal material layer 10 is hardened by being pressed with a slightly weak pressure and irradiated with ultraviolet rays to have a predetermined shape.

Alternatively, a layer that is hardened or solubilized with ionizing radiation may be formed, exposed with ionizing radiation, developed, and then etched using the photonic crystal material layer 10 as an etching resist. Examples of ionizing radiation include visible light, ultraviolet light, infrared light, electron beam, X-ray, and gamma ray. Examples of the material that can be cured by ionizing radiation include resists such as calixarene, and examples of the material that can be solubilized by ionizing radiation include resin resists such as acrylic, pyrimidine, and novolac.

  Etching is preferably an anisotropic etching method. Anisotropic etching is etching having a property of suppressing etching with respect to the orientation in the film surface direction. Specifically, oxygen, argon, fluorine For example, a dry etching method using plasma such as a system gas can be used. After the etching, the etching resist may be peeled off. Examples of the stripper include alkali resist strippers such as sodium hydroxide and aqueous potassium hydroxide, and organic solvents such as toluene.

  In the nanoimprint process or photolithography, a very narrow and deep (high aspect ratio) fine groove can be formed. Accordingly, since the size of the island of the layer in which the color changes can be processed to be considerably small, there is an effect that a finer color display device can be obtained.

Further, the photonic crystal material layer 10 whose color is changed by a change in potential may be directly formed on the display device substrate 90, but the photonic crystal material layer 10 and the islands are formed on the base sheet 60 having releasability. A transfer sheet 65 in which adhesive layers 70 patterned in a shape are sequentially formed (see FIG. 5), and a part of the photonic crystal material layer 10 is removed by etching using the adhesive layer 70 as a resist (see FIG. 6). Next, the transfer sheet 65 is laminated on the display device base material 90 on which the driver layer 8 is formed on the back surface (see FIG. 7), and then the base sheet 60 having releasability is peeled to form the driver layer 8 on the back surface. The island-shaped adhesive layer 70 and the island-shaped photonic crystal material layer 10 may be transferred and formed on the display device substrate 90 (see FIG. 8).

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In these methods, the photonic crystal material layer 10 can be formed roll-to-roll and wide on the substrate sheet 60 having releasability, and can be easily patterned in an island shape, so that the productivity is greatly improved. There is.

  As the base sheet 60 having releasability, 5-800 μm acrylic, polycarbonate, polyester, polybutylene terephthalate having a surface coated with a resin such as fluorine, silicon, melamine, polypropylene, polyamide, polyurethane, polyvinyl chloride, polyvinyl chloride. Examples thereof include resin films such as vinyl chloride.

Examples of the adhesive layer 70 include layers made of acrylic, urethane, vinyl, and rubber resins. General-purpose printing methods such as gravure, screen, and offset, methods using various coaters, methods such as painting and dipping It is good to form with. As a method for patterning the adhesive layer 70 in an island shape, the above-described photolithography or the like may be used. As the etching method, the aforementioned anisotropic etching method or the like may be used. If only the portion of the photonic crystal material layer 10 where the adhesive layer 70 is formed can be transferred while leaving the portion of the photonic crystal material layer 10 where the adhesive layer 70 is not formed on the base sheet 60. The step of etching the photonic crystal material layer 10 using the adhesive layer instead of the resist (that is, the steps of FIGS. 6 and 14) may be omitted. Alternatively, the adhesive layer 70 may be formed on the entire surface after a part of the photonic crystal material layer 10 is separately removed by etching with a resist and patterned into an island shape.

  Examples of the transfer method include a thermal transfer method in which a heated pad is pressed, a dry laminate method in which adhesion is performed through another laminate adhesive layer, and a simultaneous molding transfer method.

  A 25 μm polyethylene terephthalate film coated with silicon resin is prepared as a substrate sheet having releasability, and a 2 μm thick photonic crystal material layer (trade name: P-ink of OPALUX Co., Ltd.) is formed on the substrate sheet having releasability. ), An adhesive layer made of novolac resin having a thickness of 1 μm was sequentially formed on the entire surface by gravure printing.

  Next, a photomask patterned in the shape of a square island having a size of 2500 μm2 separated by a groove of 5 μm width is placed on the adhesive layer, exposed to exposure light from a metal halide lamp light source, developed with tetramethylammonium hydroxide, and the adhesive layer is Patterned into islands. Next, dry etching was performed to obtain a transfer sheet in which the color changing layer was also patterned in an island shape.

Next, the transfer sheet was laminated on a display device substrate made of a black polyester film having a thickness of 2 mm and a TFT driver layer made of pentacene having a pixel size of 200 μm square on the back surface and heated to 200 ° C. The silicon pad was pressed with a pressure of 2 atm for 2 seconds. After cooling, when the substrate sheet having the releasability of the transfer sheet was peeled off, a color display device was obtained in which island-like island-like photonic crystal material layers and adhesive layers were transferred and formed on the display device substrate. .

When the obtained color display device was driven by changing the potential in the range of −1, 6V to + 2V, the color of the photonic crystal material layer changed according to the change of the potential. Note that there was a slight misalignment between the color changing layer and the TFT driver layer , but there was no effect on the color display of each pixel, and the desired full-color display was possible. It was possible to do.

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1 , 200 Color display device 8 driver layer
10 Photonic crystal material layers 15, 16, 17, 18, 19, 20 Islands less than the size of each pixel
28 groove 50 pixel 60 substrate sheet having releasability
65 Transfer sheet 70 Adhesive layer 80, 81 Driver layer pattern
90 0 Display device substrate
110 Layer made of photonic crystal material

Claims (8)

Display device base material, driver layer patterned in pixel unit on one side of the display device base material, and photonic crystal material formed on the surface of the display device base material on which the driver layer is formed or on the opposite surface And the thickness of the layer made of the photonic crystal material is changed by a change in potential generated by driving each pattern of the driver layer , and the refractive index is changed so that the color of reflected light is reversibly in pixel units. A color display device which changes , wherein the photonic crystal material layer is divided into islands having a size equal to or smaller than a pixel size.   2. The color display device according to claim 1, wherein a size of the divided island is ¼ to 1/1000 of a pixel size. Color display device according to any one of claims 1-2, characterized in that the islands each other configured the separated by the independent completely separate. Color display device according to any one of claims 1 to 3, island each other configured the separated by is characterized in that it is connected in some. The color display device according to claim 1, wherein the brightness of the display device substrate is 0 to 4 in the Munsell color system based on JIS-Z-8721: 1993. A method for manufacturing a color display device according to any one of claims 1 to 5 , wherein the method of dividing the photonic crystal material layer into islands is by nanoimprinting. . A method for manufacturing a color display device according to any one of claims 1 to 6 , wherein the method of dividing the photonic crystal material layer into islands is by photolithography. . A method of manufacturing a color display device according to any one of claims 1 to 7, characterized in that formed on the display device substrate by a transfer method photonic crystal material layer separated in the island A method for manufacturing a color display device.

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