IP Library Granted Patent US 6,961,104
Granted Patent B2
US 6,961,104 · App. 10/421,723 · Granted Nov 1, 2005

Transflective liquid crystal display device and fabricating method thereof

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Quick Facts
Patent No.
US 6,961,104
App. No.
10/421,723
Granted
Nov 1, 2005
Kind
B2
Abstract

A transflective liquid crystal display device includes: first and second substrates facing and spaced apart from each other, the first and second substrates having reflective and transmissive portions; a first retardation film on an outer surface of the first substrate, the first retardation film having a first optical axis; a first polarizing plate on the first retardation film, the first polarizing plate having a first transmissive axis; a common electrode on an inner surface of the first substrate; a pixel electrode on an inner surface of the second substrate; a second retardation film on an outer surface of the second substrate, the second retardation film having a second optical axis; a second polarizing plate on the second retardation film, the second polarizing plate having a second transmissive axis; and a liquid crystal layer between the common electrode and the pixel electrode, the liquid crystal layer having a director, wherein the first optical axis has a first angle of θ with respect to the first transmissive axis, the director has a second angle of 2θ+45° with respect to the first transmissive axis, the second optical axis has a third angle of 3θ+90° with respect to the first transmissive axis, and the second transmissive axis has a fourth angle of 4θ with respect to the first transmissive axis.

Claims (32)

1. A transflective liquid crystal display device, comprising:

first and second substrates facing and spaced apart from each other, the first and second substrates having reflective and transmissive portions;

a first retardation film on an outer surface of the first substrate, the first retardation film having a first optical axis;

a first polarizing plate on the first retardation film, the first polarizing plate having a first transmissive axis;

a common electrode on an inner surface of the first substrate;

a pixel electrode on an inner surface of the second substrate;

a second retardation film on an outer surface of the second substrate, the second retardation film having a second optical axis;

a second polarizing plate on the second retardation film, the second polarizing plate having a second transmissive axis; and

a liquid crystal layer between the common electrode and the pixel electrode, the liquid crystal layer having a director,

wherein the first optical axis has a first angle of θ with respect to the first transmissive axis, the director has a second angle of 2θ+45° with respect to the first transmissive axis, the second optical axis has a third angle of 3θ+90° with respect to the first transmissive axis, and the second transmissive axis has a fourth angle of 4θ with respect to the first transmissive axis.

2. The device according to claim 1 , wherein a first cell gap defined as a thickness of the liquid crystal layer within the transmissive portion is about twice as large as a second cell gap defined as a thickness of the liquid crystal layer within the reflective portion.

3. The device according to claim 2 , further comprising an insulating layer between the inner surface of the second substrate and the pixel electrode, wherein the insulating layer has a first transmissive hole corresponding to the transmissive portion.

4. The device according to claim 1 , wherein the first angle of θ is within a range of about 15° to about 17.5°.

5. The device according to claim 1 , wherein the pixel electrode includes a reflective electrode and a transmissive electrode, wherein the reflective electrode has a second transmissive hole corresponding to the transmissive portion.

6. The device according to claim 5 , further comprising a passivation layer between the reflective electrode and the transmissive electrode.

7. The device according to claim 6 , wherein the reflective electrode is formed over the transmissive electrode.

8. The device according to claim 6 , wherein the transmissive electrode is formed over the reflective electrode.

9. The device according to claim 1 , further comprising a first orientation film between the common electrode and the liquid crystal layer and a second orientation film between the pixel electrode and the liquid crystal layer.

10. The device according to claim 1 , wherein the first and second retardation films are half wave plates (HWPs).

11. A fabricating method of a transflective liquid crystal display device, comprising:

forming a common electrode on a first substrate having reflective and transmissive portions;

forming a pixel electrode on a second substrate having the reflective and transmissive portions;

attaching the first and second substrates such that the common electrode faces the pixel electrode;

forming a liquid crystal layer between the common electrode and the pixel electrode, the liquid crystal layer having a director,

forming a first retardation film on an outer surface of the first substrate, the first retardation film having a first optical axis;

forming a first polarizing plate on the first retardation film, the first polarizing plate having a first transmissive axis;

forming a second retardation film on an outer surface of the second substrate, the second retardation film having a second optical axis; and

forming a second polarizing plate on the second retardation film, the second polarizing plate having a second transmissive axis,

wherein the first optical axis has a first angle of θ with respect to the first transmissive axis, the director has a second angle of 2θ+45° with respect to the first transmissive axis, the second optical axis has a third angle of 3θ+90° with respect to the first transmissive axis, and the second transmissive axis has a fourth angle of 4θ with respect to the first transmissive axis.

12. The method according to claim 11 , wherein the first retardation film and the first polarizing plate are a single plate, wherein the single plate is formed on the outer surface of the first substrate.

13. The method according to claim 11 , wherein the second retardation film and the second polarizing plate are a single plate, wherein the single plate is formed on the outer surface of the attached second substrate.

14. The device according to claim 11 , wherein the first and second retardation films are half wave plates (HWPs).

Assignments (2)
CHANGE OF NAME Recorded Jun 19, 2008
From: LG.PHILIPS LCD CO., LTD.
To: LG DISPLAY CO., LTD.
Reel/Frame 021147/0009 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 24, 2003
From: BAEK, HEUM-II
To: LG.PHILIPS LCD CO., LTD.
Reel/Frame 014008/0170 →