Image display medium, and image display device equipped with the image display medium

1. An image display medium comprising:

a display substrate that is at least transparent;

a back substrate opposing the display substrate with a gap therebetween;

at least two or more kinds of moving particle groups that are chargeable and that are different colors, the moving particle groups being enclosed between the display substrate and the back substrate and moving between the substrates in accordance with an electric field formed between the substrates;

a transparent liquid for dispersing the moving particles, the transparent liquid being enclosed between the display substrate and the back substrate; and

a colored member disposed between the display substrate and the back substrate, and having gaps through which the moving particle groups can move, and being a color that is different from the colors of the moving particle groups,

wherein the colored member is structured by a colored particle group whose particles have a volume average particle diameter larger than a volume average particle diameter of particles of the moving particle groups, and

wherein a size of the particles of the colored particle group structuring the colored member is greater than or equal to 10 times the size of the particles of the moving particle groups.

2. The image display medium of claim 1 , wherein a transparent porous member, which has through-holes through which the moving particle groups can move, is disposed between the display substrate and the colored particle group structuring the colored member.

3. The image display medium of claim 1 , wherein the colored member is structured by a porous member having through-holes through which the moving particle groups can move.

4. The image display medium of claim 1 , wherein the colored member is disposed so as to abut the display substrate.

5. The image display medium of claim 1 , wherein the colored member is disposed with a gap between the colored member and the display substrate.

6. The image display medium of claim 1 , wherein the colored member moves in accordance with an electric field formed between the substrates.

7. The image display medium of claim 1 , wherein a color of the colored member is white, and, when there are two kinds of the moving particle groups, the colors thereof are black and a chromatic color.

8. The image display medium of claim 1 , wherein a color of the colored member is black, and, when there are two kinds of the moving particle groups, the colors thereof are white and a chromatic color.

9. The image display medium of claim 1 , wherein a color of the colored member is a chromatic color, and, when there are two kinds of the moving particle groups, the colors thereof are white and black.

10. The image display medium of claim 1 , wherein, when the image display medium is sectioned into at least three cells, combinations of chromatic colors of the moving particles and the colored member in the three cells are combinations of red, green and blue, or combinations of yellow, magenta and cyan.

11. An image display device comprising:

the image display medium of claim 1 ;

a first electrode disposed at a display substrate side;

a second electrode disposed at a back substrate side; and

voltage applying unit for applying voltage between the first electrode and the second electrode and forming an electric field between the substrates.

12. An image display medium comprising:

a display substrate that is at least transparent;

a back substrate opposing the display substrate with a gap therebetween;

at least two or more kinds of moving particle groups that are chargeable and that are different colors, the moving particle groups being enclosed between the display substrate and the back substrate and moving between the substrates in accordance with an electric field formed between the substrates;

a transparent liquid for dispersing the moving particles, the transparent liquid being enclosed between the display substrate and the back substrate; and

a colored member disposed between the display substrate and the back substrate, and having gaps through which the moving particle groups can move, and being a color that is different from the colors of the moving particle groups,

wherein the colored member is structured by a colored particle group whose particles have a volume average particle diameter larger than a volume average particle diameter of particles of the moving particle groups, and

wherein a surface roughness of the particles of the colored particle group structuring the colored member is greater than the volume average particle diameter of the moving particle groups.

13. An image display medium comprising:

a display substrate that is at least transparent;

a back substrate opposing the display substrate with a gap therebetween;

at least two or more kinds of moving particle groups that are chargeable and that are different colors, the moving particle groups being enclosed between the display substrate and the back substrate and moving between the substrates in accordance with an electric field formed between the substrates;

a transparent liquid for dispersing the moving particles, the transparent liquid being enclosed between the display substrate and the back substrate; and

a colored member disposed between the display substrate and the back substrate, and having gaps through which the moving particle groups can move, and being a color that is different from the colors of the moving particle groups,

wherein the colored member is structured by a colored particle group whose particles have a volume average particle diameter larger than a volume average particle diameter of particles of the moving particle groups, and

wherein the particles of the colored particle group structuring the colored member have attached thereto accessory particles whose the volume average particle diameter is smaller than the volume average particle diameter of the particles of the colored particle group and greater than the volume average particle diameter of the particles of the moving particle groups.

14. The image display medium of claim 13 , wherein the the accessory particles are attached to the colored particle group at a covering ratio of 1% to 30%.