Color electrophoretic display
View Patent ↗The present invention is directed to a color display device wherein each of the display cells is filled with an electrophoretic fluid comprising two types of charged pigment particles dispersed in a colored medium. Multiple colors of high quality may be achieved by the present invention.
1. A display device comprising display cells, wherein each of said display cells is
a) sandwiched between a first layer comprising a common electrode and a second layer comprising a pixel electrode, and
b) filled with a display fluid comprising a first type of pigment particles which is white and a second type of pigment particles which is red, green or blue, and said two types of pigment particles are oppositely charged and are dispersed in a black solvent,
wherein said black solvent comprises non-charged or slightly charged black particles dispersed in a clear and colorless solvent.
2. The display device of claim 1 , wherein said white pigment particles are formed from TiO 2 .
3. The display device of claim 1 , wherein at least one type of the pigment particles are encapsulated pigment particles.
4. The display device of claim 1 , wherein said display fluid further comprises a charge control agent.
5. The display device of claim 1 , wherein said non-charged or slightly charged black particles are substantially transparent.
6. The display device of claim 1 , wherein the non-charged or slightly charged black particles have a zeta potential of <20.
7. The display device of claim 1 , wherein the non-charged or slightly charged black particles are polymeric and are in the form of a transparent polymeric matrix, with dye molecules embedded in the matrix.
8. The display device of claim 1 , wherein each display cell defines a sub-pixel and three sub-pixels forms a pixel.
9. A display device comprising display cells, wherein each of said display cells is
a) sandwiched between a first layer comprising a common electrode and a second layer comprising a pixel electrode, and
b) filled with a display fluid comprising a first type of pigment particles which is white and a second type of pigment particles which is red, green or blue, and said two types of pigment particles are oppositely charged and are dispersed in a colored solvent which has a color complementary to the color of the second type of pigment particles,
wherein the colored solvent comprises non-charged or slightly charged colored particles dispersed in a clear and colorless solvent.
10. The display device of claim 9 , wherein each display cell defines a sub-pixel and three sub-pixels form a pixel.
11. The display device of claim 9 , wherein said display fluid further comprises a charge control agent.
12. The display device of claim 9 , wherein said non-charged or slightly charged colored particles are substantially transparent.
13. The display device of claim 9 , wherein the non-charged or slightly charged colored particles have a zeta potential of <20.
14. The display device of claim 9 , wherein the non-charged or slightly charged colored particles are polymeric and are in the form of a transparent polymeric matrix, with dye molecules embedded in the matrix.
15. A display device comprising display cells and a white background layer, wherein each of said display cells is
a) sandwiched between a first layer comprising a common electrode and a second layer comprising a pixel electrode and at least one in-pane electrode, and
b) filled with a display fluid comprising a first type of pigment particles which are white and a second type of pigment particles which are red, green or blue, and said two types of pigment particles are oppositely charged and are dispersed in a colored solvent which has a color complementary to the color of the second type of pigment particles,
wherein the colored solvent comprises non-charged or slightly charged colored particles dispersed in a clear and colorless solvent.
16. The display device of claim 15 , wherein each display cell defines a sub-pixel and two sub-pixels form a pixel.
17. The display device of claim 15 , wherein said display fluid further comprises a charge control agent.
18. The display device of claim 15 , wherein said non-charged or slightly charged colored particles are substantially transparent.
19. The display device of claim 15 , wherein the non-charged or slightly charged colored particles have a zeta potential of <20.
20. The display device of claim 15 , wherein the non-charged or slightly charged colored particles are polymeric and are in the form of a transparent polymeric matrix, with dye molecules embedded in the matrix.