Electrophoretic display with dual-mode switching

• US 7,271,947 B2
• Filed: 02/14/2003
• Issued: 09/18/2007
• Est. Priority Date: 08/16/2002
• Status: Expired due to Fees

• Current Assignee: E Ink California, LLC (E Ink Holdings Incorporated)
• Original Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Inventors: Liang, Rong-Chang, Chung, Jerry
• Primary Examiner(s): Spestor; David
• Assistant Examiner(s): TRA, TUYEN Q
• Application Number:
  US10/367,595
• Publication Number:
  US 20040032390A1
• Time in Patent Office: 1,677 Days
• Field of Search: 359/296, 430/32, 430/34, 430/38, 204/600, 204/450, 345/105, 345/107
• US Class Current: 359/296
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/16762 having three or more electrodes per pixel
• CPC Class Codes: G02F 1/16766 for active matrices
• CPC Class Codes: G02F 1/1681 having two or more microcells partitioned by walls, e.g. of microcup type
• CPC Class Codes: G02F 2202/28 Adhesive materials or arrangements
• CPC Class Codes: G09G 2300/04 Structural and physical details of display devices
• CPC Class Codes: G09G 2300/06 Passive matrix structure, i.e. with direct application of both column and row voltages to the light emitting or modulating elements, other than LCD or OLED
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167
• CPC Class Codes: G09G 3/3446 with more than two electrodes controlling the modulating element

Abstract

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.

Claims

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.