LIQUID CRYSTAL DISPLAY DEVICE

• US 20140320791A1
• Filed: 04/24/2014
• Published: 10/30/2014
• Est. Priority Date: 04/25/2013
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: OIWA, Mika, OKA, Shinichiro, MATSUSHIMA, Toshiharu
• Granted Patent: US 9,207,503 B2
• Time in Patent Office: Days
• US Class Current: 349/123
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
• CPC Class Codes: G02F 1/133784 by rubbing
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 2201/124 interdigital

Abstract

A pixel electrode formed into a slit structure with striped electrodes opposed to each other for a zero rubbing angle can provide fast response since rotational directions of the liquid crystals become opposite at both sides of the slit in the striped electrodes. The electrode structure, however, poses a problem of low transmittance.

Provided is a liquid crystal display device of IPS-Pro scheme including a pixel electrode with one pair of striped electrodes. The first striped electrode includes a short electrode section and long electrode sections, and the second striped electrode also includes a short electrode section and long electrode sections. The long electrode sections of the first striped electrode are disposed adjacently to those of the second striped electrode. Liquid crystals are aligned in a lengthwise direction of the striped electrodes.

Claims

1. A liquid crystal display device, comprising:

a common electrode having a flat structure;

a pixel electrode disposed above the common electrode via an insulating film;

an alignment film disposed on the pixel electrode; and

a liquid crystal layer disposed on the alignment film, wherein

the pixel electrode includes one pair of striped electrodes,

a first striped electrode of the striped electrodes pair includes a short electrode section and a plurality of long electrode sections,

a second striped electrode of the striped electrodes pair includes a short electrode section and a plurality of long electrode sections,

one of the long electrode sections belonging to the first striped electrode is disposed adjacently to one of the long electrode sections belonging to the second striped electrode,

the short electrode section belonging to the first striped electrode is disposed at an opposed position with respect to the long electrode sections belonging to the second striped electrode,

the short electrode sections of the first and second striped electrodes are shorter than the long electrode sections of the first and second striped electrodes, and

liquid crystals are aligned in a lengthwise direction of the striped electrodes.

2. The liquid crystal display device according to claim 1, wherein the pixel electrode has a slit to constitute the pair of striped electrodes.

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

the pixel electrode includes a contact hole in a place different from where the slit is located,

the common electrode includes a hole, and

the hole is close to the contact hole.

4. The liquid crystal display device according to claim 1, further comprising a gate line, wherein the lengthwise direction of the striped electrodes is parallel to a direction in which the gate line extends.

5. The liquid crystal display device according to claim 1, further comprising a source line, wherein the lengthwise direction of the striped electrodes is orthogonal to a direction in which the source line extends.

6. The liquid crystal display device according to claim 1, wherein the liquid crystal layer is made from a material that has a positive dielectric anisotropy.

7. The liquid crystal display device according to claim 1, wherein, of the first striped electrode, a distance between the adjacent two long electrode sections is shorter than a distance between the adjacent long and short electrode sections.

8. The liquid crystal display device according to claim 7, wherein the short electrode section belonging to the first striped electrode is nested between the adjacent long electrode sections belonging to the second striped electrode.

9. A liquid crystal display device, comprising:

a common electrode having a flat structure;

a pixel electrode disposed above the common electrode via an insulating film;

an alignment film disposed on the pixel electrode; and

a liquid crystal layer disposed on the alignment film, wherein

the pixel electrode includes a first striped electrode and a second striped electrode,

the first striped electrode includes

a first electrode section extending in a first direction, and

a first short electrode section, a second long electrode section, and a third long electrode section, each extending from the first electrode section to a second direction crossing the first direction,

the second striped electrode includes

a second electrode section extending in a first direction, and

a fourth short electrode section, a fifth long electrode section, and a sixth long electrode section, each extending from the second electrode section to the second direction,

the first short electrode section has a distal end disposed at an opposed position with respect to the second electrode section between the fifth long electrode section and the sixth long electrode section,

the third short electrode section has a distal end disposed at an opposed position with respect to the first electrode section between the second long electrode section and the third long electrode section,

the third long electrode section and the sixth long electrode section are adjacent to each other,

the first short electrode section and the fourth short electrode section are shorter than the second long electrode section, the third long electrode section, the fifth long electrode section, and the sixth long electrode section, and

liquid crystals are aligned in the second direction.

10. The liquid crystal display device according to claim 9, wherein the first direction and the second direction are orthogonal to each other.

11. The liquid crystal display device according to claim 9, wherein the pixel electrode has a slit to constitute the first striped electrode and the second striped electrode.

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

the pixel electrode includes a contact hole in a place different from where the slit is located,

the common electrode includes a hole, and

the hole is close to the contact hole.

13. The liquid crystal display device according to claim 9, further comprising a gate line extended in the first direction.

14. The liquid crystal display device according to claim 9, further comprising a source line extended in the second direction.

15. The liquid crystal display device according to claim 9, wherein the liquid crystal layer is made from a material that has a positive dielectric anisotropy.