Transflective liquid crystal display device with balanced color purity

• US 7,292,298 B2
• Filed: 03/20/2007
• Issued: 11/06/2007
• Est. Priority Date: 09/19/2002
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Tsai, Ching-Yu, Ko, Fu-Jen
• Primary Examiner(s): Ton; Toan
• Application Number:
  US11/723,496
• Publication Number:
  US 20070188684A1
• Time in Patent Office: 231 Days
• Field of Search: 349/106, 349113-114
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133555 Transflectors

Abstract

A transflective LCD device. The device includes a first color filter on a first substrate, and a reflective electrode on the first color filter. The reflective electrode has an opaque portion and a transparent portion. A second color filter is formed on an inner side of a second substrate opposite the first substrate. A common electrode is on the second color filter, and a liquid crystal layer is between the first and the second substrates. Another transflective LCD device is provided, including a first color filter on a first substrate, a reflective layer on part of the first color filter, a second color filter on the reflective layer and the first color filter, a transparent electrode on the second color filter, and a common electrode on an inner side of a second substrate opposite the first substrate.

Claims

1. A transflective liquid crystal display device, comprising:

a first substrate and a second substrate opposite thereto, wherein the first substrate comprises a first color region, a second color region and a third color region;

a first color filter on the first substrate, wherein the first color filter comprises;

a first color pattern comprising a first color major portion in the first color region, and first color bumps in the second color region and the third color region;

a second color pattern comprising a second color major portion covering the first color bumps in the second color region to have an uneven surface, and second color bumps on the major portion of the first color pattern in the first color region;

a third color pattern covering the first color bumps in the third color region to have an uneven surface;

a reflective electrode on the first color filter, wherein the reflective electrode has at least one opaque portion and at least one transparent portion;

a second color filter on an inner side of the second substrate;

a common electrode on the second color filter; and

a liquid crystal layer between the first substrate and the second substrate.

2. The transflective LCD device according to claim 1, further comprising:

an insulating layer formed between the first color filter and the reflective electrode.

3. The transflective LCD device according to claim 1, wherein the first substrate is a substrate comprising a thin film transistor (TFT) array.

4. The transflective LCD device according to claim 1, wherein the opaque portion of the reflective electrode is an aluminum layer having an uneven surface.

5. The transflective LCD device according to claim 1, wherein the transparent portion of the reflective electrode is an ITO (indium tin oxide) or IZO (indium zinc oxide) layer.

6. The transflectiye LCD device according to claim 1, wherein partial surfaces of the first color filter have bumps.

7. A method for forming a transflective liquid crystal display device, comprising:

providing a first substrate, comprising a first color region, a second color region and a third color region;

forming a first color pattern comprising a first color major portion in the first color region, and first color bumps in the second color region and the third color region;

forming a second color pattern comprising a second color major portion covering the first color bumps in the second color region to have uneven surface, and second color bumps on the first color major portion of the first color pattern in the first color region;

forming a third color pattern covering the first color pattern in the third color region to have uneven surface, wherein the first color pattern, the second color pattern and the third color pattern constitute a first color filter;

forming a reflective electrode on the first color filter, wherein the reflective electrode has at least one opaque portion and at least one transparent portion;

forming a second color filter overlying the reflective electrode;

providing a second substrate; and

forming a liquid crystal layer between the first substrate and the second substrate.

8. The method for forming a transflective liquid crystal display device according to claim 7, wherein the second color filter is directly formed on the reflective electrode.

9. The method for forming a transflective liquid crystal display device according to claim 7, wherein the second color filter is formed on a inner surface of the second substrate.

10. A transflective liquid crystal display device, comprising:

a first substrate and a second substrate opposite thereto, wherein the first substrate comprises a first color region, a second color region and a third color region;

a first color filter on the first substrate, wherein the first color filter comprises;

a first color pattern comprising a first color major portion in the first color region, and first color bumps in the second color region and the third color region;

a second color pattern comprising a second color major portion covering the first color bumps in the second color region to have an uneven surface, and second color bumps on the major portion of the first color pattern in the first color region;

a third color pattern covering the first color bumps in the third color region to have an uneven surface;

a reflective electrode disposed on the corresponding part of the first color bumps and the second color bumps;

a second color filter on an inner side of the second substrate;

a common electrode on the second color filter; and

a liquid crystal layer between the first substrate and the second substrate.

11. The transflective LCD device according to claim 10, further comprising:

an insulating layer formed between the first color filter and the reflective electrode.