Electrophoretic display with color filters

• US 20030021005A1
• Filed: 07/26/2002
• Published: 01/30/2003
• Est. Priority Date: 07/27/2001
• Status: Active Grant

• Current Assignee: E Ink California, LLC (E Ink Corporation)
• Original Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Inventors: Wu, Zarng-Arh George, Liang, Rong-Chang, Tseng, Scott C-J, Zang, Hongmei
• Granted Patent: US 6,850,355 B2
• Time in Patent Office: Days
• US Class Current: 359/296
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/1677 Structural association of cells with optical devices, e.g. reflectors or illuminating devices
• CPC Class Codes: G02F 1/1679 Gaskets; Spacers; Sealing of cells; Filling or closing of cells

Abstract

This invention relates to an electrophoretic display comprising a transparent top viewing electrode, a bottom electrode and a plurality of isolated cells having well-defined size, shape and aspect ratio, said cells filled with charged pigment particles dispersed in a dielectric solvent or solvent mixture, and a color filter placed with the top transparent electrode.

Claims

1. An electrophoretic display comprising

(a) a transparent top viewing electrode;

(b) a bottom electrode;

(c) a plurality of isolated cells having well-defined size, shape and aspect ratio, said cells filled with charged pigment particles dispersed in a dielectric solvent or solvent mixture; and

(d) a color filter layer.

2. The electrophoretic display of claim 1 wherein the transparent top viewing electrode is a transparent conductor film on transparent plastic substrate.

3. The electrophoretic display of claim 1 wherein the bottom electrode is a conductor film or a substrate containing thin film transistors.

4. The electrophoretic display of claim 2 wherein said color filter layer is on the top of the transparent plastic substrate layer.

5. The electrophoretic display of claim 2 wherein said color filter layer is between the top conductor film and the plastic substrate layer.

6. The electrophoretic display of claim 2 wherein said color filter layer is underneath the top conductor film.

7. The electrophoretic display of claim 1 wherein the cells are substantially uniform in size and shape.

8. The electrophoretic display of claim 1 wherein the plurality of cells comprises cells of different sizes and shapes.

9. The electrophoretic display of claim 1 wherein the cells are non-spherical.

10. The electrophoretic display of claim 1 wherein the cells are formed from microcups with an opening area ranging from about 10² to about 1×

10⁶ μ

m².

11. The electrophoretic display of claim 1 wherein the cells are formed from microcups with an opening area ranging from about 10³ to about 1×

10⁵ μ

m².

12. The electrophoretic display of claim 1 wherein the cells are formed from microcups with an opening having a circular, polygonal, hexagonal, rectangular or square shape.

13. The electrophoretic display of claim 1 wherein the cells have a depth in the range from about 5 to about 100 microns.

14. The electrophoretic display of claim 1 wherein the cells have a depth in the range from about 10 to about 50 microns.

15. The electrophoretic display of claim 1 wherein the cells have an opening to total area ratio in the range from about 0.05 to about 0.95.

16. The electrophoretic display of claim 1 wherein the cells have an opening to total area ratio in the range from about 0.4 to about 0.9.

17. The electrophoretic display of claim 1 is a monochrome display.

18. The electrophoretic display of claim 1 is a multiple color display.

19. The electrophoretic display of claim 1 wherein said color filter is of the same color or different colors for said individual cells.

20. The electrophoretic display of claim 1 wherein said color filter comprises stripes of red, green and blue color.

21. The electrophoretic display of claim 1 wherein said color filter further comprises a black matrix.

22. The electrophoretic display of claim 1 wherein said particles are white or colored.

23. The electrophoretic display of claim 1 wherein said dielectric solvent is black or of other colors.

24. The electrophoretic display of claim 1 wherein said particles carry opposite charges.

25. The electrophoretic display of claim 24 wherein the positively charged particles are white and the negatively charged particles are colored.

26. The electrophoretic display of claim 24 wherein the positively charged particles are colored and the negatively charged particles are white.