Reflective type liquid crystal display device and fabricating method thereof

• US 7,791,691 B2
• Filed: 05/20/2009
• Issued: 09/07/2010
• Est. Priority Date: 11/12/2003
• Status: Active Grant

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: LG Display Co., Ltd.
• Inventors: Lee, Jong Hwae, Hur, Jae Hong
• Primary Examiner(s): Kim; Richard H
• Application Number:
  US12/453,739
• Publication Number:
  US 20100003883A1
• Time in Patent Office: 475 Days
• Field of Search: None
• US Class Current: 349/106
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 2201/16 series; tandem
• CPC Class Codes: G02F 2201/44 Arrangements combining different electro-active layers, e.g. electrochromic, liquid crystal or electroluminescent layers
• CPC Class Codes: G02F 2203/02 reflective

Abstract

The present invention provides a reflective type liquid crystal display device and fabricating method thereof, by which resolution is enhanced in a manner of representing two colors from one sub-pixel. The present invention includes a first substrate having a plurality of thin film transistors and a plurality of pixel electrodes within a plurality of sub-pixels defined by a plurality of gate and data lines perpendicularly crossing with each other, respectively, a second substrate assembled to the first substrate to confront, a liquid crystal layer between the first and second substrates, a third substrate assembled to the first substrate to confront, a plurality of reflective electrodes on an inside of the third substrate to correspond to a plurality of the sub-pixels, respectively, and a color filter layer having a plurality of electrophoretic bodies on a plurality of the reflective electrodes wherein each of the electrophoretic bodies is micro-encapsulated with ionic pigment particles.

Claims

1. A method of fabricating a reflective type liquid crystal display device, comprising the steps of:

forming a plurality of gate and data line on a first substrate to define a plurality of sub-pixels;

forming a plurality of thin film transistors at a plurality of crossings of a plurality of the gate and data lines;

forming a plurality of pixel electrodes connected to a plurality of the thin film transistors, respectively;

assembling a second substrate to oppose the first substrate;

forming a liquid crystal layer between the first and second substrates;

forming a plurality of reflective electrodes on a third substrate to correspond to a plurality of the sub-pixels, respectively;

forming a counter electrode directly on the first substrate and facing the third substrate;

forming a color filter layer on the plurality of reflective electrodes comprising a plurality of electrophoretic bodies wherein each of the electrophoretic bodies is micro-encapsulated with ionic pigment particles, wherein each electrophoretic body has two pigment particles among R, G and B pigment particles, and the color filter layer is formed between the first substrate and the third substrate; and

assembling the third substrate to the first substrate to confront.

2. The method of claim 1, wherein each of the electrophoretic bodies is colored by differently-colored pigment particles to be encapsulated with oppositely charged ionic substances.

3. The method of claim 1, wherein a plurality of the electrophoretic bodies is formed by methods of spin coating, dipping, dispensing, printing, ink jet, and screen coating.

4. The method of claim 1, wherein each of the reflective electrodes has a size corresponding to that of each of sub-pixels or to that of each unit pixel line.

5. The method of claim 4, wherein a positive or negative voltage is applied to each of the reflective electrodes.

6. The method of claim 4, wherein each of the electrophoretic bodies is formed on each of the reflective electrodes by encapsulating at least two of R, G, and B pigment particles.

7. The method of claim 1, further comprising the step of forming a partition wall between a plurality of the reflective electrodes.

8. The method of claim 1, wherein a plurality of the reflective electrodes is formed a low resistance metal layer.

9. The method of claim 1, wherein each of the pixel electrodes is formed of a transparent conductive material.

10. The method of claim 1, wherein the third substrate is assembled to the first substrate by pressurizing.

11. The method of claim 1, further comprising:

forming a black matrix and a common electrode on an inside of the second substrate.