Reflective color display

Patent metadata

Field	Value
Publication number	US-9494841-B2
Application number	US-201414491410-A
Country	US
Kind code	B2
Filing date	Sep 19, 2014
Priority date	Mar 21, 2012
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

An electrophoretic reflective color display has a color filter on an electrophoretic display layer displaying black and white. A colored portion and a non-colored portion are provided in a pixel of the color filter layer, and the colored portion has a hue defined by specified values of chromaticity coordinates (a*, b*), measured with transmitted light using a D65 light source, in a chromaticity diagram of the L*a*b* color system.

First claim

The invention claimed is:

1. A reflective color display, comprising:
a substrate;
an electrophoretic display layer formed on the substrate;
a light transmissive electrode layer formed on the electrophoretic display layer; and
a color filter layer formed on the light transmissive electrode layer and including at least one colored portion and a non-colored portion in a pixel located on the light transmissive electrode layer,
wherein the colored portion has a green hue defined by a chromaticity coordinate (a*, b*) in a chromaticity diagram of the L*a*b* color system satisfying −70≦a*≦−30 and −20≦b*≦20, where the chromaticity coordinate is measured with transmitted light using a D65 light source.

2. The reflective color display of claim 1 , wherein the colored portion and the non-colored portion in the pixel have an area ratio ranging from 1:1 to 1:7.

3. The reflective color display of claim 1 , wherein the colored portion has an area of not less than 25% in the pixel.

4. A reflective color display, comprising:
a substrate;
an electrophoretic display layer formed on the substrate;
a light transmissive electrode layer formed on the electrophoretic display layer; and
a color filter layer formed on the light transmissive electrode layer and including at least one colored portion and a non-colored portion in a pixel located on the light transmissive electrode layer,
wherein the colored portion has a yellow hue defined by a chromaticity coordinate (a*, b*) in a chromaticity diagram of the L*a*b* color system satisfying −20≦a*≦20 and 30≦b* ≦70, where the chromaticity coordinate is measured with transmitted light using a D65 light source.

5. The reflective color display of claim 4 , wherein the colored portion and the non-colored portion in the pixel have an area ratio ranging from 1:1 to 1:7.

6. The reflective color display of claim 5 , further comprising:
a plurality of pixel electrodes formed on the substrate; and
an adhesive layer formed on the pixel electrodes,
wherein the electrophoretic display layer is formed on the adhesive layer.

7. The reflective color display of claim 6 , wherein the electrophoretic display layer comprises a plurality of microcapsules and a binder resin fixing the microcapsules therein.

8. The reflective color display of claim 4 , wherein the colored portion has an area of not less than 25% in the pixel.

9. A reflective color display, comprising:
a substrate;
an electrophoretic display layer formed on the substrate;
a light transmissive electrode layer formed on the electrophoretic display layer; and
a color filter layer formed on the light transmissive electrode layer and including at least one colored portion and a non-colored portion in a pixel located on the light transmissive electrode layer,
wherein the colored portion is provided in a plurality and comprises a first colored portion and a second colored portion, the first colored portion has a red hue defined by a chromaticity coordinate (a*, b*) in a chromaticity diagram of the L*a*b* color system satisfying 30≦a*≦70 and −20≦b*≦20, and the second colored portion has a green hue defined by the chromaticity coordinate satisfying −70≦a*≦−30 and −20≦b*≦20, where the chromaticity coordinate is measured with transmitted light using a D65 light source.

10. The reflective color display of claim 9 , wherein the first colored portion and the second colored portion each have an area of not less than 25% in the pixel.

11. The reflective color display of claim 9 , wherein the first colored portion and the second colored portion have a total area of not less than 40% in the pixel.

12. The reflective color display of claim 9 , wherein the first colored portion and the second colored portion have a total area of 40-50% in the pixel.

13. The reflective color display of claim 12 , further comprising:
a plurality of pixel electrodes formed on the substrate; and
an adhesive layer formed on the pixel electrodes,
wherein the electrophoretic display layer is formed on the adhesive layer.

14. The reflective color display of claim 13 , wherein the electrophoretic display layer comprises a plurality of microcapsules and a binder resin fixing the microcapsules therein.

15. A reflective color display, comprising:
a substrate;
an electrophoretic display layer formed on the substrate;
a light transmissive electrode layer formed on the electrophoretic display layer; and
a color filter layer formed on the light transmissive electrode layer and including at least one colored portion and a non-colored portion in a pixel located on the light transmissive electrode layer,
wherein the colored portion is provided in a plurality and comprises a third colored portion and a fourth colored portion, the third colored portion has a blue hue defined by a chromaticity coordinate (a*, b*) in a chromaticity diagram of the L*a*b* color system satisfying −20≦a*≦20 and −70≦b*≦−30, and the fourth colored portion has a yellow hue defined by the chromaticity coordinate satisfying −20≦a*≦20 and 30≦b*≦70, where the chromaticity coordinate is measured with transmitted light using a D65 light source.

16. The reflective color display of claim 15 , wherein the third colored portion and the fourth colored portion each have an area of not less than 25% in the pixel.

17. The reflective color display of claim 15 , wherein the third colored portion and the fourth colored portion have a total area of not less than 40% in the pixel.

18. The reflective color display of claim 15 , wherein the third colored portion and the fourth colored portion have a total area of 40-50% in the pixel.

19. The reflective color display of claim 18 , further comprising:
a plurality of pixel electrodes formed on the substrate; and
an adhesive layer formed on the pixel electrodes,
wherein the electrophoretic display layer is formed on the adhesive layer.

20. The reflective color display of claim 19 , wherein the electrophoretic display layer comprises a plurality of microcapsules and a binder resin fixing the microcapsules therein.

Assignees

• Toppan Printing Co Ltd

Inventors

• Kitazawa Kazushige

Classifications

• G02F1/133514 Primary

  Colour filters · CPC title

• G02F2203/02

  reflective · CPC title

• G02B5/201 Primary

  in the form of arrays · CPC title

• G02F1/167 Primary

  by electrophoresis · CPC title

• G02F1/1677

  Structural association of cells with optical devices, e.g. reflectors or illuminating devices · CPC title