JP6488780B2 - Color filter and electronic paper - Google Patents

Description

  The present invention relates to a color filter for reflection type electronic paper and electronic paper.

  In recent years, electronic paper, which is a flat type display device, has been developed. Electronic paper displays characters, images, and the like by controlling reflected light of ambient light (hereinafter also referred to as “environmental light”). Such electronic paper has excellent characteristics such as low power consumption, no eye fatigue, and good visibility under direct sunlight.

  In addition, as electronic paper capable of color display, one having a color filter having a plurality of colored layers and a reflective display element capable of performing white display and black display is known (for example, a patent) Reference 1). This electronic paper can display a desired color image by reflecting ambient light by performing white display using a reflective display element and transmitting the reflected light through a color filter.

JP 2003-280044 A

  In electronic paper, display characteristics with a wide viewing angle are desired. In order to realize such display characteristics, a configuration in which a scattering layer including a plurality of scattering particles is provided on a color filter and reflected light is scattered by the scattering layer can be considered.

  FIG. 11 is a diagram showing scattering characteristics of a conventional color filter. FIG. 6 shows that when the scattering layer is not provided on the color filter and when the scattering layer is provided, the color filter is arranged between the light source and the light receiver, and the light receiving angle of the light receiver is ± 30. It shows the results of measuring the scattering intensity of red, green, and blue light while changing in the range of °. As shown in FIG. 11, the scattering intensity of red, green, and blue light at a light receiving angle of about 6 ° or more and about −6 ° or less is almost 0 when no scattering layer is provided. It is increasing when there is. That is, the viewing angle characteristics can be improved.

  However, even when the number of scattering particles, the material and shape, the thickness of the scattering layer, and the like are adjusted using the scattering layer including such scattering particles, the viewing angle characteristics are greatly improved from the example of FIG. It is difficult to improve.

  The present invention has been made in consideration of such points, and an object thereof is to provide a color filter and electronic paper that can further improve the viewing angle characteristics.

The color filter for electronic paper according to an embodiment of the present invention,
A transparent substrate;
A colored layer provided on the transparent substrate;
A first scattering layer provided on the opposite side of the colored layer from the transparent substrate,
The first scattering layer has an uneven shape on the surface thereof.

In the above color filter,
The refractive index of the first scattering layer may be higher than the refractive index of the member of the electronic paper adjacent to the uneven shape.

In the above color filter,
The refractive index of the first scattering layer may be lower than the refractive index of the member of the electronic paper adjacent to the uneven shape.

In the above color filter,
The first scattering layer includes
A first transparent resin;
And an inorganic film that is provided on a surface of the first transparent resin and forms the uneven shape.

In the above color filter,
The first scattering layer includes
A first transparent resin;
And a refractive index adjusting agent dispersed in the first transparent resin.

In the above color filter,
The uneven shape of the first scattering layer may be formed by shaping.

In the above color filter,
The first scattering layer includes a plurality of unit optical elements each forming a part of the uneven shape,
The plurality of unit optical elements are arranged in a predetermined arrangement direction,
Each of the unit optical elements may have an asymmetric shape in the arrangement direction.

In the above color filter,
The first scattering layer includes a plurality of unit optical elements each forming a part of the uneven shape,
Each of the unit optical elements may have a shape of a part of a sphere or a spheroid.

In the above color filter,
The first scattering layer includes
A first transparent resin;
Scattering particles dispersed in the first transparent resin,
The uneven shape of the first scattering layer may be formed due to the presence of the scattering particles.

In the above color filter,
A second scattering layer provided between the first scattering layer and the colored layer;
The second scattering layer is
A second transparent resin;
And scattering particles dispersed in the second transparent resin.

Electronic paper according to an embodiment of the present invention,
The color filter;
A reflective display element that performs white display and black display, disposed so as to face the color filter;
It is characterized by providing.

  According to the present invention, viewing angle characteristics can be further improved.

It is a longitudinal cross-sectional view which shows schematic structure of the electronic paper which concerns on 1st Embodiment. It is the top view which looked at the color filter from the arrow I direction of FIG. It is a figure which shows the scattering characteristic of the color filter of FIG. It is a longitudinal cross-sectional view which shows schematic structure of the color filter which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows schematic structure of the color filter which concerns on 3rd Embodiment. It is a longitudinal cross-sectional view which shows schematic structure of the color filter which concerns on 4th Embodiment. FIG. 7 is a longitudinal sectional view showing a manufacturing process of the color filter of FIG. 6. It is a top view of the exposure mask of FIG. It is a longitudinal cross-sectional view which shows schematic structure of the color filter which concerns on 5th Embodiment. It is a longitudinal cross-sectional view which shows schematic structure of the color filter which concerns on 6th Embodiment. It is a figure which shows the scattering characteristic of the conventional color filter.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual ones.

(First embodiment)
First, the entire electronic paper 100 will be described with reference to FIG.

Electronic Paper FIG. 1 is a longitudinal sectional view showing a schematic configuration of an electronic paper 100 according to the first embodiment. As shown in FIG. 1, the electronic paper 100 includes a color filter 10 for electronic paper, and a reflective display element 80 arranged to face the color filter 10 and performing white display and black display. Yes.

  The color filter 10 includes a transparent substrate 11, a black matrix layer (hereinafter referred to as a BM layer) 12 provided on the transparent substrate 11, and a plurality of colored layers 13 provided on the transparent substrate 11. The transparent first scattering layer 14 provided on the opposite side to the transparent base material 11 of the colored layer 13, that is, on the reflective display element 80 side of the colored layer 13. That is, the color filter 10 is a color filter with a scattering layer.

  The colored layer 13 includes a first colored area 20, a second colored area 30, a third colored area 40, and a white area 50. Each of the first colored area 20, the second colored area 30, the third colored area 40, and the white area 50 corresponds to one pixel.

  The color filter 10 is disposed so that the first scattering layer 14 and the reflective display element 80 face each other. Therefore, an observer observes the electronic paper 100 from the transparent base material 11 side (z direction side).

  Ambient light enters the reflective display element 80 through the color filter 10 from the viewer side. The reflective display element 80 is configured to control whether or not ambient light is reflected for each pixel. The reflective display element 80 performs white display by reflecting the ambient light and performs black display by not reflecting the ambient light. Therefore, the reflective display element 80 can display characters and images without using a backlight. A front light that irradiates light to the reflective display element 80 from the observer side when the ambient light is weak may be provided. In this case, the light from the front light enters the color filter 10 from a direction inclined with respect to the z direction.

  The display method of the reflective display element 80 is not particularly limited, and a known one can be applied. For example, an electrophoresis method, a twist ball method, a powder movement method (an electronic powder fluid method, a charged toner type method). ), Liquid crystal display method, thermal method (coloring method, light scattering method), electrochromic method, electrowetting method, and magnetophoresis method.

  Here, as an example, an electrowetting reflective display element 80 will be schematically described. The reflective display element 80 includes a white substrate 81, a plurality of first transparent electrodes 82 provided on the white substrate 81, a hydrophobic insulating layer 83 provided on the first transparent electrode 82, and a hydrophobic insulating layer. 83, a plurality of pixel side walls 84 provided on 83, an oil layer 85 provided between adjacent pixel side walls 84, and a transparent liquid 86 provided on the oil layer 85 and the pixel side walls 84. Note that a second transparent electrode may be provided on the liquid 86. A transparent substrate may be provided on the second transparent electrode. In these cases, an adhesive layer may be provided between the second transparent electrode or the transparent substrate and the uneven shape of the first scattering layer 14.

  Each oil layer 85 is located on the corresponding first transparent electrode 82. One set of the first transparent electrode 82 and the oil layer 85 corresponds to one pixel.

  When no voltage is applied to the first transparent electrode 82, the oil layer 85 covers the hydrophobic insulating layer 83 between adjacent pixel side walls 84 as shown in the figure. Since the oil layer 85 is colored, for example, black, the incident ambient light is not reflected by the oil layer 85 and black display is performed.

  On the other hand, when a voltage is applied to the first transparent electrode 82 corresponding to a certain pixel, although not shown, the oil layer 85 corresponding to this pixel moves to one pixel side wall 84 side and corresponds to this pixel. The liquid 86 comes into contact with the hydrophobic insulating layer 83 at the position. Thereby, in this pixel, the incident environmental light reaches the white substrate 81 and is reflected by the white substrate 81 to perform white display.

  In this way, the electronic paper 100 can perform a desired color image display by reflecting the ambient light by performing white display using the reflective display element 80 and transmitting the reflected light to the color filter 10. . Here, since the reflected light from the reflective display element 80 is scattered by the first scattering layer 14 and then passes through the color filter 10, display characteristics close to paper and display characteristics with a wide viewing angle can be obtained.

Color Filter Next, the color filter 10 will be described in detail with reference to FIG. FIG. 2 is a plan view of the color filter 10 as viewed from the direction of arrow I in FIG. For convenience of explanation, the first scattering layer 14 is omitted in FIG. The cross-sectional view of the color filter 10 in FIG. 1 corresponds to the AA cross section in FIG.

(Transparent substrate)
As the transparent substrate 11, various materials that can appropriately support the BM layer 12, the colored layer 13, and the first scattering layer 14 and have transparency are used. For example, glass, polymer, or the like is used.

(BM layer)
The BM layer 12 is configured to shield ambient light from the observer side and reflected light from the reflective display element 80. In the present embodiment, the BM layer 12 has a matrix pattern.

  The plurality of regions defined by the BM layer 12 are any one of a region for the first colored area 20, a region for the second colored area 30, a region for the third colored area 40, and a region for the white area 50, respectively. It has become. The specific pattern of each region defined by the BM layer 12 is not particularly limited.

  The material of the BM layer 12 is not particularly limited as long as it has a desired light shielding property. For example, a resin composition containing a black colorant such as carbon black or titanium black can be used. As the resin used in this resin composition, for example, a photosensitive resin having a reactive vinyl group such as acrylate, methacrylate, polyvinyl cinnamate, or cyclized rubber is used.

(Colored layer)
As shown in FIG. 2, the colored layer 13 includes a plurality of unit pixels 16 arranged in a matrix. Each unit pixel 16 includes three colored areas (a first colored area 20, a second colored area 30, and a third colored area 40) and a white area 50, which are arranged in a matrix. Below, when it is not necessary to distinguish the 1st coloring area 20, the 2nd coloring area 30, and the 3rd coloring area 40 from each other, these are called the coloring areas 20, 30, and 40.

  The colored areas 20, 30, 40 and the white area 50 are provided between regions defined by the BM layer 12, that is, between the BM layers 12. The thicknesses of the colored areas 20, 30, 40 and the white area 50 are substantially equal.

  The first coloring area 20, the second coloring area 30, the third coloring area 40, and the white area 50 are repeatedly arranged in this order in the x direction. A plurality of sets of the colored areas 20, 30, 40 and the white area 50 that are repeatedly arranged in this way are arranged in the y direction. The arrangement order of the colored areas 20, 30, 40 and the white area 50 is not limited to the example illustrated.

  For example, the 1st coloring area 20 consists of a blue coloring layer which permeate | transmits blue light, the 2nd coloring area 30 consists of a green coloring layer which permeate | transmits green light, and the 3rd coloring area 40 permeate | transmits red light. It consists of a red colored layer.

  The white area 50 includes a white colored layer that transmits white light. More specifically, the white area 50 transmits visible light substantially uniformly regardless of the wavelength range. Therefore, the visible light transmittance of the white area 50 is higher than the visible light transmittance of the colored areas 20, 30, 40.

  By providing the white area 50 having such a high transmittance, the transmittance of the color filter 10 as a whole can be improved as compared with the case where only the colored areas 20, 30 and 40 are provided in the color filter 10. it can. Thereby, the brightness of the electronic paper 100 can be increased.

  Each of the colored areas 20, 30, 40 and the white area 50 is a layer formed by patterning a photosensitive colored area material by a photolithography method including an exposure process and a development process. As the coloring area material to be patterned by the photolithography method, any of negative and positive coloring area materials can be used. The order of forming the colored areas 20, 30, 40 and the white area 50 may be any order.

[Coloring area materials]
Next, a first colored area material (hereinafter referred to as a first material), a second colored area material (hereinafter referred to as a second material), and a third colored area constituting each colored area 20, 30, 40 and white area 50. The material for use (hereinafter referred to as the third material) and the material for the white area (hereinafter referred to as the fourth material) will be described. Each of the first to fourth materials includes a pigment dispersion including pigments and dyes of each color and a dispersant, a photoinitiator, a clearing agent including a polymer and a monomer, and a surfactant. Of these, the photoinitiator generates a radical component when irradiated with light. Further, the clearing agent contains at least a component that causes a polymerization reaction by a radical generated by the photoinitiator and cures, and a component that can dissolve the unexposed portion by subsequent development.

  Thus, each colored area 20, 30, 40 and white area 50 is configured to transmit light of the corresponding color, while the BM layer 12 is configured to shield light.

(First scattering layer)
As shown in FIG. 1, the first scattering layer 14 has a concavo-convex shape on its surface, that is, the surface facing the reflective display element 80. The first scattering layer 14 includes a plurality of unit optical elements 60 that each form a part of an uneven shape. The plurality of unit optical elements 60 are arranged in a predetermined arrangement direction (x direction).

  Although not shown, each unit optical element 60 may extend linearly along the arrangement direction (x direction) and the y direction orthogonal to the z direction. In this case, each unit optical element 60 is formed in a columnar shape and has the same cross-sectional shape along the longitudinal direction thereof, that is, along the y direction.

  The cross section shown in FIG. 1, that is, a cross section parallel to both the arrangement direction (x direction) of the unit optical elements 60 and the normal direction (z direction) of the transparent substrate 11 (hereinafter simply referred to as “first scattering layer 14”). Each unit optical element 60 has an asymmetric triangular shape in the arrangement direction (x direction). Such an asymmetric shape can improve the scattering characteristics as compared with the case of a symmetric shape.

  Note that at least some of the unit optical elements 60 may have different cross-sectional shapes on the main cut surface. In such a configuration, the unit optical element 60 can exhibit scattering characteristics different from those in the case where the main cutting surface has the same cross-sectional shape.

  The shape of the unit optical element 60 is not limited to the illustrated example, but a part of a sphere (for example, a hemisphere), a part of a spheroid (for example, a half spheroid), a polygonal pyramid such as a cone and a quadrangular pyramid, and the like. As an example, a truncated cone, a truncated cone, and a truncated cone such as a polygonal truncated pyramid can be given. The shape of the unit optical element 60 may be appropriately selected according to necessary scattering characteristics.

  The refractive index of the first scattering layer 14 is higher than the refractive index of the member of the electronic paper 100 adjacent to the uneven shape, that is, the refractive index of the liquid 86 of the reflective display element 80 in the illustrated example. As described above, the second transparent electrode is provided on the liquid 86, the transparent substrate is provided on the second transparent electrode, and the adhesive layer is provided between the transparent substrate and the uneven shape of the first scattering layer 14. In some cases, the refractive index of the first scattering layer 14 is higher than the refractive index of the adhesive layer.

  Or the refractive index of the 1st scattering layer 14 may be lower than the refractive index of the member of the electronic paper 100 adjacent to uneven | corrugated shape. In general, the material of the first scattering layer 14 can be easily selected when the refractive index of the first scattering layer 14 is higher than the refractive index of the member of the electronic paper 100 adjacent to the uneven shape.

  The visible light transmittance of the first scattering layer 14 is preferably 85% or more, and more preferably 90% or more. The 1st scattering layer 14 is comprised from transparent thermoplastic resins, such as a polycarbonate-type resin, for example. A thermoplastic resin will not be specifically limited if transparency, a refractive index, etc. are satisfy | filled.

  The uneven shape of the first scattering layer 14 may be formed by shaping. That is, the molding member having the concavo-convex shape is pressed against the heated thermoplastic resin, and the concavo-convex shape of the molding member is transferred to the first scattering layer 14. By using shaping, the uneven shape of the first scattering layer 14 can be easily formed, and an arbitrary uneven shape can be formed.

  FIG. 3 is a diagram showing the scattering characteristics of the color filter 10 of FIG. FIG. 3 shows the result of measuring the scattering intensity of red, green, and blue light by arranging the color filter 10 between the light source and the light receiver, changing the light receiving angle of the light receiver within a range of ± 30 °. Show. 3 and FIG. 11, the vertical scale is the same.

  As shown in FIG. 3, when the light receiving angle is about 6 ° or more and about −6 ° or less, the red, green, and blue light scattering intensities are stronger than the conventional one shown in FIG. Therefore, the viewing angle characteristic is wider than the conventional one shown in FIG.

  As described above, according to the present embodiment, the refraction direction of light is changed using the uneven shape of the first scattering layer 14 and the refractive index difference between the first scattering layer 14 and the liquid 86 as a whole. Wide viewing angle characteristics can be provided. Therefore, by appropriately adjusting the concavo-convex shape and refractive index of the first scattering layer 14, it is possible to obtain a wide viewing angle characteristic that cannot be achieved when only the scattering layer including scattering particles is provided. That is, the viewing angle characteristic can be further improved.

  Thereby, it is possible to obtain excellent display characteristics even when, for example, a front light is used. That is, the light from the front light enters the color filter 10 from a direction inclined with respect to the z direction, but a suitable scattering characteristic can be obtained even for such light due to the wide viewing angle characteristic.

  In addition, since the white area 50 having a higher transmittance than the colored areas 20, 30, 40 is provided, the amount of light taken out to the observer side is increased, and a decrease in luminance due to scattering can be suppressed.

  Note that when the decrease in luminance due to scattering is small, the white area 50 may not be provided.

(Second Embodiment)
The second embodiment is different from the first embodiment in that the first scattering layer 14 </ b> A has an inorganic film 62. Hereinafter, a description will be given focusing on differences from the first embodiment.

  FIG. 4 is a longitudinal sectional view showing a schematic configuration of a color filter 10A according to the second embodiment. The first scattering layer 14A of the color filter 10A includes a first transparent resin 61 and an inorganic film 62 that is provided on the surface of the first transparent resin 61 and forms an uneven shape. In the present embodiment, the refractive index of the first scattering layer 14 </ b> A represents the refractive index of the inorganic film 62.

  Therefore, when the refractive index of the first scattering layer 14A is higher than the refractive index of the member (for example, the liquid 86) of the electronic paper 100 adjacent to the uneven shape, for example, ITO may be used as the material of the inorganic film 62. .

  Further, when the refractive index of the first scattering layer 14A is lower than the refractive index of the member of the electronic paper 100 adjacent to the uneven shape, a material having an appropriate refractive index may be used as the material of the inorganic film 62.

  As a method for forming the first scattering layer 14A, an uneven shape (a plurality of unit optical elements 60) is formed by molding on the surface of the first transparent resin 61 made of a thermoplastic resin as in the first embodiment. The inorganic film 62 may be formed on the uneven shape. As a result, the inorganic film 62 forms an uneven shape.

  According to this embodiment, even if it is difficult to obtain a necessary refractive index with the first transparent resin 61, the refractive index can be set by the inorganic film 62. Therefore, the color filter 10A can be easily manufactured. Moreover, the same effect as 1st Embodiment is also acquired.

(Third embodiment)
The third embodiment is different from the first embodiment in that the first scattering layer 14B has the refractive index adjusting particles 63. Hereinafter, a description will be given focusing on differences from the first embodiment.

  FIG. 5 is a longitudinal sectional view showing a schematic configuration of a color filter 10B according to the third embodiment. The first scattering layer 14 </ b> B of the color filter 10 </ b> B includes a first transparent resin 61 and a plurality of refractive index adjusting particles (refractive index adjusting agents) 63 dispersed in the first transparent resin 61. Therefore, the refractive index of the first scattering layer 14 </ b> B can be adjusted by adjusting the refractive index, content, average particle diameter, and the like of the refractive index adjusting particles 63.

  The material of the refractive index adjusting particles 63 is not particularly limited as long as it has a refractive index adjusting function. It is preferable that the refractive index adjusting particles 63 have transparency. This is because the transmittance of the first scattering layer 14B can be improved. The average particle diameter of the refractive index adjusting particles 63 may be in the range of 100 nm or more and 600 nm or less, for example. The refractive index adjusting particles 63 may be spherical, for example.

  As a method for forming such a first scattering layer 14B, the refractive index adjusting particles 63 are mixed in the first transparent resin 61 made of a thermoplastic resin, and the surface of the first transparent resin 61 has an uneven shape (a plurality of units). The optical element 60) may be formed by shaping.

  According to the present embodiment, even when it is difficult to obtain a necessary refractive index with the first transparent resin 61, the refractive index of the first scattering layer 14B can be easily adjusted by the refractive index adjusting particles 63. it can. Therefore, the color filter 10B can be easily manufactured. Moreover, the same effect as 1st Embodiment is also acquired.

(Fourth embodiment)
The fourth embodiment is different from the first embodiment in that a concavo-convex shape is formed using photolithography. Hereinafter, a description will be given focusing on differences from the first embodiment.

  FIG. 6 is a longitudinal sectional view showing a schematic configuration of a color filter 10C according to the fourth embodiment. The first scattering layer 14C of the color filter 10C includes a plurality of unit optical elements 60C that each form a part of an uneven shape. Each unit optical element 60C has a shape of a part of a sphere or a spheroid. In the cross section shown in FIG. 6, that is, the main cutting plane of the first scattering layer 14C, each unit optical element 60C has a substantially symmetrical shape in the arrangement direction (x direction).

  At least some of the unit optical elements 60C may have different shapes. The plurality of unit optical elements 60C may be irregularly arranged. As a result, the scattering characteristics can be improved.

  Such an uneven shape (a plurality of unit optical elements 60C) can be formed using photolithography. That is, first, a scattering layer coating solution having photosensitivity is prepared by mixing a scattering layer material containing a transparent resin or the like and a solvent. Then, the scattering layer coating liquid is applied to the entire surface of the BM layer 12 and the colored layer 13 formed on the transparent substrate 11. Next, as shown in FIG. 7, the scattering layer material 65 obtained by heating the scattering layer coating solution is exposed using an exposure mask M1.

  FIG. 8 is a top view of the exposure mask M1 of FIG. FIG. 7 corresponds to the BB cross section of FIG. The exposure mask M1 has a plurality of circular openings OP1, and portions other than the openings OP1 shield exposure light. For this reason, exposure is performed on the region corresponding to the opening OP1, but the degree of exposure decreases as it goes from the central portion of the opening OP1 to the edge portion.

  Therefore, as shown in FIG. 7, an exposed portion 65 a having a shape of a part of a sphere is formed in the scattering layer material 65 at a position corresponding to the opening OP <b> 1. Therefore, the scattering layer material 65 can be developed to form the first scattering layer 14C having an uneven shape corresponding to the exposed portion 65a.

According to this embodiment, the same effect as the first embodiment can be obtained.
Note that the fourth embodiment may be combined with the second or third embodiment.

(Fifth embodiment)
The fifth embodiment is different from the first embodiment in that the uneven shape of the first scattering layer 14 </ b> D is formed due to the presence of the scattering particles 66. Hereinafter, a description will be given focusing on differences from the first embodiment.

  FIG. 9 is a longitudinal sectional view showing a schematic configuration of a color filter 10D according to the fifth embodiment. The first scattering layer 14 </ b> D of the color filter 10 </ b> D includes a first transparent resin 61 and a plurality of scattering particles 66 that exhibit a light scattering action dispersed in the first transparent resin 61.

  The uneven shape of the first scattering layer 14 </ b> D is formed due to the presence of the scattering particles 66. More specifically, the concavo-convex shape is formed such that the outline of the scattering particles 66 is raised.

  The material of the scattering particles 66 is not particularly limited as long as it has a light scattering action. For example, inorganic substances such as titanium oxide, zirconia, silicon dioxide, aluminum oxide, barium sulfate, acrylic resins, divinylbenzene resins, benzoguanamine resins, styrene resins, melamine resins, acrylic-styrene resins, polycarbonate resins, Examples thereof include organic substances such as polyethylene resins and polyvinyl chloride resins, and fine particles such as a mixture of two or more thereof.

  The scattering particles 66 are preferably transparent. This is because the transmittance of the first scattering layer 14D can be improved. As such scattering particles 66, for example, a melamine resin, a benzoguanamine resin, or the like may be used.

  The average particle diameter of the scattering particles 66 is, for example, in the range of 100 nm or more and 600 nm or less. The shape of the scattering particles 66 may be spherical, for example. What is necessary is just to determine suitably the average particle diameter and shape of the scattering particle 66 according to the uneven | corrugated shape to form. The refractive index of the scattering particles 66 may be larger than the refractive index of the first transparent resin 61. The content of the scattering particles 66 is not particularly limited as long as it is an amount that can scatter light and does not impair the transparency of the first scattering layer 14D.

  The formation method of the first scattering layer 14D is not particularly limited. For example, after scattering particles 66 are mixed in a heated thermoplastic resin and formed into a film shape, the thermoplastic resin is thermally contracted by cooling. You may make it the outline of the scattering particle 66 emerge.

  According to the present embodiment, in addition to the scattering due to the uneven shape of the first scattering layer 14D, scattering due to the scattering particles 66 also occurs, so that the viewing angle characteristics can be improved as compared with the first embodiment. Further, since the scattering particles 66 are irregularly located and the particle diameters thereof also vary, the uneven shape is inevitably formed irregularly. That is, an irregular uneven shape can be easily formed. Further, the viewing angle characteristics can be further improved by the irregular uneven shape.

(Sixth embodiment)
The sixth embodiment is different from the first embodiment in that the second scattering layer 70 is further provided. Hereinafter, a description will be given focusing on differences from the first embodiment.

  FIG. 10 is a longitudinal sectional view showing a schematic configuration of a color filter 10E according to the sixth embodiment. The color filter 10 </ b> E includes a second scattering layer 70 provided between the first scattering layer 14 and the colored layer 13.

  The second scattering layer 70 includes a second transparent resin 71 and a plurality of scattering particles 72 dispersed in the second transparent resin 71. The second transparent resin 71 may be made of the same material as the resin that forms the first scattering layer 14. The scattering particles 72 may be the same as the scattering particles 66 of the fifth embodiment.

  The 2nd scattering layer 70 can be formed by apply | coating the coating liquid for scattering layer formation containing the 2nd transparent resin 71 and the scattering particle 72 on the colored layer 13, and hardening this. Thereafter, the first scattering layer 14 may be formed on the second scattering layer 70 by the same method as in the first embodiment.

  According to the present embodiment, in addition to scattering by the first scattering layer 14, scattering by the second scattering layer 70 also occurs, so that the viewing angle characteristics can be improved as compared to the first embodiment.

  The sixth embodiment may be combined with any of the second to fifth embodiments.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

10, 10A, 10B, 10C, 10D, 10E Color filter 11 Transparent substrate 12 Black matrix layer (BM layer)
13 colored layers 14, 14A, 14B, 14C, 14D first scattering layer 16 unit pixel 20 first colored area 30 second colored area 40 third colored area 50 white area 60, 60C unit optical element 61 first transparent resin 62 inorganic Film 63 Refractive index adjusting particle (refractive index adjusting agent)
65 Scattering layer material 66 Scattering particle 70 Second scattering layer 71 Second transparent resin 72 Scattering particle 80 Reflective display element 100 Electronic paper

Claims (9)

A color filter for electronic paper,
A transparent substrate;
A colored layer provided on the transparent substrate;
A first scattering layer provided on the opposite side of the colored layer from the transparent substrate,
Wherein the first scattering layer, have a concave-convex shape on its surface,
The first scattering layer includes
A first transparent resin;
And a refractive index adjusting agent dispersed in the first transparent resin .   The color filter according to claim 1, wherein a refractive index of the first scattering layer is higher than a refractive index of a member of the electronic paper adjacent to the uneven shape.   2. The color filter according to claim 1, wherein a refractive index of the first scattering layer is lower than a refractive index of a member of the electronic paper adjacent to the uneven shape. Wherein the uneven shape of the first scattering layer is formed by shaping, color filter according to any one of claims 1 to 3, characterized in that. The first scattering layer includes a plurality of unit optical elements each forming a part of the uneven shape,
The plurality of unit optical elements are arranged in a predetermined arrangement direction,
The color filter according to claim 4 , wherein each of the unit optical elements has an asymmetric shape in the arrangement direction. The first scattering layer includes a plurality of unit optical elements each forming a part of the uneven shape,
Each of the unit optical elements, the color filter according to any one of claims 1 to 4 having the shape of a portion of a sphere or spheroid, that is characterized. A color filter for electronic paper,
A transparent substrate;
A colored layer provided on the transparent substrate;
A first scattering layer provided on the opposite side of the colored layer from the transparent substrate,
The first scattering layer has an uneven shape on its surface,
The first scattering layer includes
A first transparent resin;
Scattering particles dispersed in the first transparent resin,
Wherein the uneven shape of the first scattering layer is formed due to the presence of the scattering particles, features and to Luke color filter that. A color filter for electronic paper,
A transparent substrate;
A colored layer provided on the transparent substrate;
A first scattering layer provided on the opposite side of the colored layer from the transparent substrate,
The first scattering layer has an uneven shape on its surface,
A second scattering layer provided between the first scattering layer and the colored layer;
The second scattering layer is
A second transparent resin;
The second having a scattering particles dispersed in a transparent resin, wherein the to Luke color filter that. The color filter according to any one of claims 1 to 8 ,
A reflective display element that performs white display and black display, disposed so as to face the color filter;
Electronic paper characterized by comprising.

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