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 fluid comprising a first type of pigment particles which is white and a second type of pigment particles which is colored, and said two types of pigment particles are oppositely charged and 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 fluid of claim 1 , wherein said second type of pigment particles is non-white and non-black.
3. The fluid of claim 1 , wherein said second type of pigment particles is red, green, blue, cyan, magenta or yellow.
4. The fluid of claim 1 , wherein said second type of pigment particles is red, green or blue.
5. The fluid of claim 1 , wherein said non-charged or slightly charged black particles are substantially transparent.
6. The fluid of claim 1 , wherein the non-charged or slightly charged black particles have a size of less than 100 nanometers.
7. The fluid of claim 1 , wherein the non-charged or slightly charged black particles have a zeta potential of <20.
8. The fluid of claim 1 , wherein the non-charged or slightly charged black particles are polymeric and in the form of a transparent polymeric matrix, with dye molecules embedded in the matrix.
9. A display device comprising the display fluid of claim 1 , wherein said fluid is sandwiched between a first layer comprising a common electrode and a second layer comprising pixel electrodes.
10. A display fluid comprising a first type of pigment particles which is white and a second type of pigment particles which is colored and said two types of pigment particles are oppositely charged and dispersed in a colored solvent, wherein the colored solvent comprises non-charged or slightly charged colored particles dispersed in a clear and colorless solvent and the color of the non-charged or slightly charged colored particles is complementary to the color of the second type of pigment particles.
11. The fluid of claim 10 , the second type of pigment particles dispersed in the colored solvent gives the appearance of a black color.
12. The fluid of claim 10 , wherein said second type of pigment particles is non-white and non-black.
13. The fluid of claim 10 , wherein said second type of pigment particles is red, green, blue, cyan, magenta or yellow.
14. The fluid of claim 10 , wherein said second type of pigment particles is red, green or blue.
15. The fluid of claim 10 , wherein said non-charged or slightly charged colored particles are substantially transparent.
16. The fluid of claim 10 , wherein said non-charged or slightly charged colored particles have a size of less than 100 nanometers.
17. The fluid of claim 10 , wherein the non-charged or slightly charged colored particles have a zeta potential of <20.
18. The fluid of claim 10 , wherein the non-charged or slightly charged colored particles are polymeric and in the form of a transparent polymeric matrix, with dye molecules embedded in the matrix.
19. A display device comprising the display fluid of claim 10 , wherein said fluid is sandwiched between a first layer comprising a common electrode and a second layer comprising pixel electrodes.
20. A display device which comprises a display fluid of claim 10 and said fluid is sandwiched between a first layer comprising a common electrode and a second layer comprising pixel electrodes and in-plane electrodes.