LIQUID CRYSTAL DISPLAY DEVICE WITH CONTROLLABLE VIEWING ANGLE AND DRIVING METHOD THEREOF

• US 20110025675A1
• Filed: 02/27/2009
• Published: 02/03/2011
• Est. Priority Date: 03/04/2008
• Status: Active Grant

• Current Assignee: Shanghai Tianma Micro-Electronics Company Limited (Tianma Microelectronics Company Limited)
• Original Assignee: Shanghai Tianma Micro-Electronics Company Limited (Tianma Microelectronics Company Limited)
• Inventors: Peng, Xuhui, Nie, Xinghua, Huo, Sitao, Ling, Zhihua
• Granted Patent: US 8,482,501 B2
• Time in Patent Office: Days
• US Class Current: 345/211
• CPC Class Codes: G02F 1/1323 Arrangements for providing a switchable viewing angle
• CPC Class Codes: G02F 1/134381 Hybrid switching mode, i.e. for applying an electric field with components parallel and orthogonal to the substrates
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2320/068 for control of viewing angle adjustment
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

A liquid crystal display device with controllable viewing angle of the present invention has an upper substrate (101) on which an upper substrate common electrode (103) is disposed, a lower substrate (102) on which a pixel electrode is disposed, and a liquid crystal layer (107) sandwiched between the upper substrate (101) and the lower substrate (102). The liquid crystal molecules are vertical to the upper substrate (101) in substance when no voltage is applied, and a plurality of parallel strip-like lower substrate common electrodes (104) are disposed on the lower substrate (102). The upper substrate common electrode (103) and the pixel electrode (105) provide an electric field perpendicular to the upper substrate (101) in order to form a first viewing angle mode when a voltage is applied, the lower substrate common electrode (104) and the pixel electrode (105) provide an electric field perpendicular to the upper substrate (101) and an electric field parallel to the upper substrate (101) in order to form a second viewing angle mode when a voltage is applied. A method of driving the said liquid crystal display device is also disclosed.

Claims

1. A liquid crystal display device comprising:

an upper substrate on which an upper substrate common electrode is disposed,

a lower substrate parallel to the upper substrate on which a pixel electrode is disposed, and

a liquid crystal layer sandwiched between the upper substrate and the lower substrate, and the liquid crystal molecules are arranged perpendicular to the upper substrate in substance when no voltage is applied,

wherein a plurality of parallel strip-like lower substrate common electrodes are disposed on the lower substrate, and

wherein the upper substrate common electrode and the pixel electrode provide an electric field perpendicular to the upper substrate when a voltage is applied to the upper substrate common electrode and the pixel electrode to form a first viewing angle mode, and the lower substrate common electrode and the pixel electrode provide an electric field perpendicular to the upper substrate and an electric field parallel to the upper substrate when a voltage is applied to the lower substrate common electrode and the pixel electrode to form a second viewing angle mode.

2. The liquid crystal display device according to claim 1, wherein the lower substrate common electrode is floated when a voltage is applied to the upper substrate common electrode and the pixel electrode, and the upper substrate common electrode is floated when a voltage is applied to the lower substrate common electrode and the pixel electrode.

3. The liquid crystal display device according to claim 1, wherein the dielectric anisotropy of the liquid crystal molecules is negative.

4. The liquid crystal display device according to claim 1, wherein an insulation layer is disposed between the lower substrate common electrode and the pixel electrode.

5. The liquid crystal display device according to claim 1, wherein the viewing direction in the first viewing angle mode is substantially perpendicular to that in the second viewing angle mode.

6. The liquid crystal display device according to claim 1, wherein the first viewing angle mode is a left viewing angle mode, and the second viewing angle mode is a lower viewing angle mode.

7. The liquid crystal display device according to claim 1, wherein the upper substrate common electrode, the lower substrate common electrode and the pixel electrode are all transparent electrodes.

8. The liquid crystal display device according to claim 7, wherein the transparent electrode includes one of ITO, IZO and IGO or a combination thereof.

9. The liquid crystal display device according to claim 1, wherein polarization plates are attached to outside of the upper substrate and the lower substrate respectively, and the direction of absorption axis of the polarization plate attached to the upper substrate is vertical to the direction of absorption axis of the polarization plate attached to the lower substrate.

10. A driving method for a liquid crystal display device, the liquid crystal display device comprising:

an upper substrate on which an upper substrate common electrode is disposed,

a lower substrate parallel to the upper substrate on which a pixel electrode is disposed, and

a liquid crystal layer sandwiched between the upper substrate and the lower substrate, liquid crystal molecules are perpendicular to the upper substrate in substance when no voltage is applied,

wherein a plurality of parallel strip-like lower substrate common electrodes are disposed on the lower substrate,

the driving method comprising the following steps;

applying a voltage to the upper substrate common electrode and the pixel electrode to generate an electric field perpendicular to the upper substrate and thus provide a first viewing angle mode;

applying a voltage to the lower substrate common electrode and the pixel electrode to generate an electric field perpendicular to the upper substrate and an electric field parallel to the upper substrate and thus provide a second viewing angle mode; and

switching between the first viewing angle mode and the second viewing angle mode by selectively applying the voltage to the upper substrate common electrode or the lower substrate common electrode.

11. The driving method for a liquid crystal display device according to claim 10, wherein the direction in the first viewing angle mode is substantially perpendicular to that in the second viewing angle mode.

12. The driving method for a liquid crystal display device according to claim 10, wherein the lower substrate common electrode is floated when the voltage is applied to the upper substrate common electrode and the pixel electrode;

and the upper substrate common electrode is floated when the voltage is applied to the lower substrate common electrode and the pixel electrode.