LIQUID CRYSTAL DISPLAY DEVICE

• US 20090059145A1
• Filed: 08/22/2008
• Published: 03/05/2009
• Est. Priority Date: 08/28/2007
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Satake, Tetsuya, Nagae, Suguru, NISHIOKA, Takahiro
• Granted Patent: US 7,995,176 B2
• Time in Patent Office: Days
• US Class Current: 349/119
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes

Abstract

The liquid crystal display device according to this invention includes a control structure provided at each of or one of a liquid crystal side of a first substrate and a liquid crystal side of a second substrate to control a tilt direction of a liquid crystal upon application of a voltage to a liquid crystal layer, a first domain where a liquid crystal tilts in one direction upon application of a voltage to a liquid crystal layer, and a second domain where a liquid crystal tilts in a direction different from the tilt direction of the liquid crystal in the first domain by substantially 180°. Herein, an angle formed by the tilt direction of the liquid crystal in the first domain and a horizontal direction of a screen in the liquid crystal display device falls within a range between 22° and 39° or a range between 51° and 68°.

Claims

1. A liquid crystal display device comprising:

a first substrate that has electrodes provided at regular intervals to apply a voltage to a liquid crystal;

a second substrate that has an electrode applying a voltage to a liquid crystal;

a liquid crystal layer that is held between said first substrate and said second substrate and is made of a negative type liquid crystal aligned in a substantially vertical direction with respect to a substrate plane;

a first polarizing plate that is provided at a side which is different from a liquid crystal side of said first substrate;

a second polarizing plate that is provided at a side which is different from a liquid crystal side of said second substrate, and has a transmission axis which is orthogonal to a transmission axis of said first polarizing plate;

a first retardation plate that is provided between said first substrate and said first polarizing plate, and has a slow axis which is not parallel with and orthogonal to the transmission axis of said first polarizing plate;

a second retardation plate that is provided between said first substrate and said first retardation plate;

a third retardation plate that is provided between said second substrate and said second polarizing plate, and has a slow axis which is orthogonal to the slow axis of said first retardation plate;

a fourth retardation plate that is provided between said second substrate and said third retardation plate, and has a slow axis which is orthogonal to a slow axis of said second retardation plate;

a control structure that is provided at each of or one of the liquid crystal side of said first substrate and the liquid crystal side of said second substrate, and controls a tilt direction of the liquid crystal upon application of the voltage to said liquid crystal layer;

a first domain where the liquid crystal tilts in one direction upon application of the voltage to said liquid crystal layer; and

a second domain where the liquid crystal tilts in a direction which is different from the tilt direction of the liquid crystal in said first domain by substantially 180°

, wherein an angle formed by the tilt direction of the liquid crystal in said first domain and a horizontal direction of a screen in said liquid crystal display device falls within a range between 22° and

39°

or a range between 51° and

68°

.

2. The liquid crystal display device according to claim 1, wherein

an angle formed by the horizontal direction of the screen in said liquid crystal display device and a control structure extension direction of said control structure falls within a range between 22°

and 39°

.

3. The liquid crystal display device according to claim 1, wherein

an angle formed by the horizontal direction of the screen in said liquid crystal display device and a control structure extension direction of said control structure falls within a range between 51°

and 68°

.

4. The liquid crystal display device according to claim 1, further comprising:

a third domain where a liquid crystal tilts in a direction which is different from the tilt direction of the liquid crystal in said first domain; and

a fourth domain where a liquid crystal tilts in a direction which is different from the tilt direction of the liquid crystal in said third domain by substantially 180°

, wherein

when the angle formed by the tilt direction of the liquid crystal in said first domain and the horizontal direction of the screen in said liquid crystal display device is defined as φ

, an angle formed by the tilt direction of the liquid crystal in said third domain and the horizontal direction of the screen in said liquid crystal display device is 180°

−

φ

, and the angle φ

falls within a range between 26° and

42°

in place of the range between 22° and

39°

or a range between 48° and

64°

in place of the range between 51° and

68°

.

5. The liquid crystal display device according to claim 4, wherein

when an angle formed by the horizontal direction of the screen in said liquid crystal display device and a control structure extension direction of said control structure in said first domain is defined as φ

, the angle formed by the tilt direction of the liquid crystal in said third domain and the horizontal direction of the screen in said liquid crystal display device is 180°

−

φ

, and the angle φ

falls within the range between 26° and

42°

.

6. The liquid crystal display device according to claim 4, wherein

when an angle formed by the horizontal direction of the screen in said liquid crystal display device and a control structure extension direction of said control structure in said first domain is defined as φ

, the angle formed by the tilt direction of the liquid crystal in said third domain and the horizontal direction of the screen in said liquid crystal display device is 180°

−

φ

, and the angle φ

falls within the range between 48° and

64°

.

7. A liquid crystal display device comprising:

a first substrate that has electrodes provided at regular intervals to apply a voltage to a liquid crystal;

a second substrate that has an electrode applying a voltage to a liquid crystal;

a liquid crystal layer that is held between said first substrate and said second substrate and is made of a negative type liquid crystal aligned in a substantially vertical direction with respect to a substrate plane;

a first polarizing plate that is provided at a side which is different from a liquid crystal side of said first substrate;

a second polarizing plate that is provided at a side which is different from a liquid crystal side of said second substrate, and has a transmission axis which is orthogonal to a transmission axis of said first polarizing plate;

a first retardation plate that is provided between said first substrate and said first polarizing plate, and has a slow axis which is not parallel with and orthogonal to the transmission axis of said first polarizing plate;

a second retardation plate that is provided between said second substrate and said second polarizing plate, and has a slow axis which is orthogonal to the slow axis of said first retardation plate;

a control structure that is provided at each of or one of the liquid crystal side of said first substrate and the liquid crystal side of said second substrate, and controls a tilt direction of the liquid crystal upon application of the voltage to said liquid crystal layer;

a first domain where the liquid crystal tilts in one direction upon application of the voltage to said liquid crystal layer; and

a second domain where the liquid crystal tilts in a direction which is different from the tilt direction of the liquid crystal in said first domain by substantially 180°

, wherein

an angle formed by the tilt direction of the liquid crystal in said first domain and a horizontal direction of a screen in said liquid crystal display device falls within a range between 25° and

39°

or a range between 51° and

65°

.

8. The liquid crystal display device according to claim 7, wherein

an angle formed by the horizontal direction of the screen in said liquid crystal display device and a control structure extension direction of said control structure falls within a range between 250 and 39°

.

9. The liquid crystal display device according to claim 7, wherein

an angle formed by the horizontal direction of the screen in said liquid crystal display device and a control structure extension direction of said control structure falls within a range between 51°

and 65°

.

10. The liquid crystal display device according to claim 7, further comprising:

a third domain where a liquid crystal tilts in a direction which is different from the tilt direction of the liquid crystal in said first domain; and

a fourth domain where a liquid crystal tilts in a direction which is different from the tilt direction of the liquid crystal in said third domain by substantially 180°

, wherein

when the angle formed by the tilt direction of the liquid crystal in said first domain and the horizontal direction of the screen in said liquid crystal display device is defined as X, an angle formed by the tilt direction of the liquid crystal in said third domain and the horizontal direction of the screen in said liquid crystal display device is 180°

−

φ

, and the angle φ

falls within a range between 29° and

35°

in place of the range between 25° and

39°

or a range between 55° and

61°

in place of the range between 51° and

65°

.

11. The liquid crystal display device according to claim 10, wherein

when an angle formed by the horizontal direction of the screen in said liquid crystal display device and a control structure extension direction of said control structure in said first domain is defined as φ

, the angle formed by the tilt direction of the liquid crystal in said third domain and the horizontal direction of the screen in said liquid crystal display device is 180°

−

φ

, and the angle φ

falls within the range between 29° and

35°

.

12. The liquid crystal display device according to claim 10, wherein

when an angle formed by the horizontal direction of the screen in said liquid crystal display device and a control structure extension direction of said control structure in said first domain is defined as φ

, the angle formed by the tilt direction of the liquid crystal in said third domain and the horizontal direction of the screen in said liquid crystal display device is 180°

−

φ

, and the angle φ

falls within the range between 55° and

61°

.