Electrophoretic display with dual-mode switching
View Patent ↗The present invention relates to an improved EPD which comprises both the traditional up/down switching and the in-plane switching modes. The monochrome EPDs of the present invention are capable of displaying highlight color of choice which is different from the text. Furthermore, the full color EPDs of the present invention are capable of displaying high contrast images of high color saturation. Both high quality black and white states are possible in the full color displays of the present invention. The EPDs of the present invention do not need complex circuitry design, and are compatible with low cost and high yield roll-to-roll manufacturing processes.
1. An electrophoretic display comprising an array of electrophoretic cells, wherein each of said electrophoretic cells is sandwiched between a top layer comprising a top electrode and a bottom layer comprising a bottom electrode and each of said electrophorectic cells comprises
(i) partition walls;
(ii) in-plane electrodes which are part of the partition walls; and
(iii) an electrophoretic composition filled therein and said electrophoretic composition comprises charged pigment particles dispersed in a dielectric solvent or solvent mixture,
whereby each of said electrophoretic cells is capable of providing a three color system, displaying the color of the charged pigment particles, or the color of the dielectric solvent or solvent mixture, or a background color.
2. The electrophoretic display of claim 1 wherein said charged pigment particles are of the white color.
3. The electrophoretic display of claim 1 wherein said top electrode is transparent.
4. The electrophoretic display of claim 1 wherein said bottom electrode is colored.
5. The electrophoretic display of claim 4 wherein said bottom electrode is blackened.
6. The electrophoretic display of claim 1 wherein said bottom electrode comprises a thin film transistor.
7. The electrophoretic display of claim 1 wherein said electrophoretic compositions of red, green and blue color are sequentially filled and top-sealed in the electrophoretic cells.
8. The electrophoretic display of claim 1 wherein said electrophoretic cells are microcups and said microcups filled with said electrophoretic composition are sealed with a polymeric top-sealing layer that encloses the electrophoretic composition within each microcup.
9. The electrophoretic display of claim 8 wherein said polymeric top-sealing layer is on the viewing side.
10. The electrophoretic display of claim 8 wherein said polymeric top-sealing layer is on the non-viewing side.
11. The electrophoretic display of claim 8 wherein said polymeric top-sealing layer is formed from a sealing composition having a specific gravity lower than that of said electrophoretic composition.
12. The electrophoretic display of claim 1 wherein said charged pigment particles are particles of mixed colors.
13. The electrophoretic display of claim 8 wherein said polymeric top-sealing layer is being cured when on top of the electrophoretic composition.
14. The electrophoretic display of claim 1 wherein said charged pigment particles carry the same charge.
15. The electrophoretic display of claim 1 wherein said charged pigment particles are of the same color.