Transflective liquid crystal display device having various cell gaps and method of fabricating the same

• US 20040114077A1
• Filed: 07/18/2003
• Published: 06/17/2004
• Est. Priority Date: 12/17/2002
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Chen, Chih-Chiang, Chuang, Ching-Sang, Chang, Jiun-Jye
• Granted Patent: US 6,870,585 B2
• Time in Patent Office: Days
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133371 Cells with varying thickness of the liquid crystal layer
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/136222 Colour filters incorporated in the active matrix substrate

Abstract

A transflective LCD device having various cell gaps. The transflective LCD device is characterized by the passivation layer being formed on a lower substrate in a reflective region. A color filter layer is formed above the passivation layer, wherein a first thickness of the color filter layer in the reflective region is smaller than a second thickness of the color filter layer in a transmissive region. A transparent organic element is formed on an inner side of an upper substrate in the reflective region for bridging a gap in a liquid crystal layer between upper and lower substrates, wherein one end of the transparent organic element shores up the lower substrate. Thus, the gap thickness in the reflective region is smaller than that in the transmissive region.

Claims

1. A transflective liquid crystal display device having various cell gaps, comprising:

a first substrate having a transmissive region and a reflective region thereon;

an array of pixel driving elements formed on the first substrate in the reflective region;

an insulating layer formed on the first substrate to cover the array of pixel driving elements;

a passivation layer formed on the insulating layer in the reflective region, wherein a top surface of the passivation layer is higher than a top surface of the insulating layer;

a conformal reflective electrode formed on the passivation layer, wherein the reflective electrode electrically connects the array of pixel driving elements;

a conformal transparent electrode formed on the insulating layer, wherein the transparent electrode electrically connects the array of pixel driving elements;

a color filter layer formed on the reflective electrode and the transparent electrode, wherein a first thickness of the color filter layer in the reflective region is smaller than a second thickness of the color filter layer in the transmissive region;

a second substrate opposite the first substrate;

a common electrode formed on an inner side of the second substrate;

a liquid crystal layer interposed between the first substrate and the second substrate; and

a transparent organic element bridging a gap in the liquid crystal layer between the first substrate and the second substrate, formed on the common electrode in the reflective region, wherein one end of the transparent organic element shores up the color filter layer, thus a third thickness of the gap in the reflective region is smaller than a fourth thickness of the gap in the transmissive region.

2. The transflective LCD device according to claim 1, wherein the array of the pixel driving elements is an array of thin film transistors (TFTs).

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

4. The transflective LCD device according to claim 1, wherein the reflective electrode is an aluminum layer or a silver layer.

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

6. The transflective LCD device according to claim 1, wherein the transparent organic element has an angular shape.

7. A method of fabricating a transflective liquid crystal display device having various cell gaps, comprising the steps of:

providing a first substrate having a transmissive region and a reflective region thereon;

forming an array of pixel driving elements on the first substrate in the reflective region;

forming an insulating layer on the first substrate to cover the array of pixel driving elements;

forming a conformal transparent electrode on the insulating layer, wherein the transparent electrode electrically connects the array of pixel driving elements;

forming a passivation layer on the insulating layer in the reflective region, wherein a top surface of the passivation layer is higher than a top surface of the insulating layer;

forming a conformal reflective electrode on the passivation layer, wherein the reflective electrode electrically connects the array of pixel driving elements;

forming a color filter layer on the reflective electrode and the transparent electrode, wherein a first thickness of the color filter layer in the reflective region is smaller than a second thickness of the color filter layer in the transmissive region;

providing a second substrate opposite the first substrate;

forming a common electrode on an inner side of the second substrate;

forming a transparent organic element on the common electrode in the reflective region for bridging a gap in a liquid crystal layer between the first substrate and the second substrate, wherein one end of the transparent organic element shores up the color filter layer, thus a third thickness of the gap in the reflective region is smaller than a fourth thickness of the gap in the transmissive region; and

filling a space between the first substrate and the second substrate with liquid crystal molecules to form the liquid crystal layer.

8. The method according to claim 7, wherein the array of the pixel driving elements is an array of thin film transistors (TFTs).

9. The method according to claim 7, wherein the transparent electrode is an ITO (indium tin oxide) layer or an IZO (indium zinc oxide) layer.

10. The method according to claim 7, wherein the reflective electrode is an aluminum layer or a silver layer.

11. The method according to claim 7, wherein the common electrode is an ITO (indium tin oxide) layer or an IZO (indium zinc oxide) layer.

12. The method according to claim 7, wherein the transparent organic element has an angular shape.