Display device

• US 10,642,103 B2
• Filed: 03/15/2018
• Issued: 05/05/2020
• Est. Priority Date: 08/27/2014
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Matsushima, Toshiharu
• Primary Examiner(s): Pan, Jia X
• Application Number:
  US15/922,399
• Publication Number:
  US 20180203310A1
• Time in Patent Office: 782 Days
• 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 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned

Abstract

According to one embodiment, a display device includes first and second substrates, and liquid crystal layer. The first substrate includes first and second electrodes. The second electrode includes comblike electrodes extending in parallel to a first direction and tapered toward tips thereof, and a connecting portion which connects the comblike electrodes. An initial alignment direction is parallel to the first direction or a direction orthogonal to the first direction. The comblike electrode includes a first part having sides each form a first angle with the first direction, and a second part having sides each form a second angle with the first direction, the second angle being greater than the first angle.

Claims

1. A display device comprising:

a first substrate including a first electrode, an insulating layer covering the first electrode, a second electrode opposed to the first electrode with the insulating layer interposed therebetween, and a first alignment film covering the second electrode;

a second substrate including a second alignment film opposed to the first alignment film; and

a liquid crystal layer including liquid crystal molecules sealed between the first alignment film and the second alignment film, wherein

the second electrode includes a plurality of comblike electrodes extending parallel to a first direction, and a connecting portion which connects the comblike electrodes,

an initial alignment direction of the liquid crystal molecules is parallel to the first direction or a second direction which is orthogonal to the first direction,

the comblike electrode includes a first part having sides opposed to each other in the second direction each form a first angle with the first direction, a second part having sides opposed to each other in the second direction each form a second angle with the first direction, and a third part having sides opposed to each other in the second direction each form a third angle with the first direction,

the second part is located between the first part and the third part,

the second angle is greater than the first angle and the third angle,

a second length of the second part in the first direction is longer than a first length of the first part in the first direction, and

the second length is longer than a third length of the third part in the first direction.

2. The display device of claim 1, wherein the first length of the first part or the third length of the third part is less than or equal to 5 μ

m.

3. The display device of claim 1, wherein the first angle or the third angle is substantially zero.

4. The display device of claim 1, wherein the second angle is greater than or equal to 1.0 degree.

5. The display device of claim 1, wherein the liquid crystal molecules have positive dielectric anisotropy, and the initial alignment direction is parallel to the first direction.

6. The display device of claim 1, wherein the comblike electrodes include a plurality of first comblike electrodes extending from the connecting portion in the first direction and arranged along the second direction, and a plurality of second comblike electrodes extending from the connecting portion in the direction opposite to the first direction and arranged along the second direction.

7. The display device of claim 6, wherein the first comblike electrodes and the second comblike electrodes are symmetrical with respect to an axis parallel to the second direction.

8. The display device of claim 6, wherein the first comblike electrodes and the second comblike electrodes are arranged alternately in the second direction.

9. The display device of claim 1, wherein the first substrate is provided with a plurality of subpixels, the second electrode is provided over the plurality of subpixels and includes an aperture closed by the connecting portion, and the comblike electrodes are arranged in the aperture.

10. A display device comprising:

a first substrate including a first electrode, an insulating layer covering the first electrode, a second electrode opposed to the first electrode with the insulating layer interposed therebetween, and a first alignment film covering the second electrode;

a second substrate including a second alignment film opposed to the first alignment film; and

a liquid crystal layer including liquid crystal molecules sealed between the first alignment film and the second alignment film, wherein

the second electrode includes a plurality of comblike electrodes extending parallel to a first direction, and a connecting portion which connects the comblike electrodes,

an initial alignment direction of the liquid crystal molecules is parallel to the first direction or a second direction which is orthogonal to the first direction,

the comblike electrode includes a first part, a second part, and a third part,

the first part is boated between the connecting portion and the second part,

the second part is located between the first part and the third part,

the first part has a first width in the second direction,

the second part is tapered toward the third part, and an end portion of the second part at the third part side has a second width smaller than the first width,

the third part has a third width in the second direction, the third width is equal to the second width,

a second length of the second part in the first direction is longer than a first length of the first part in the first direction, and

the second length is longer than a third length of the third part in the first direction.

11. The display device of claim 10, wherein the first length of the first part or the third length of the third part is less than or equal to 5 μ

m.

12. The display device of claim 10, wherein

the first part has sides opposed to each other in the second direction each form a first angle with the first direction, and

the first angle is substantially zero.

13. The display device of claim 10, wherein

the second part has sides opposed to each other in the second direction each form a second angle with the first direction, and

the second angle is greater than or equal to 1.0 degree.

14. The display device of claim 10, wherein the liquid crystal molecules have positive dielectric anisotropy, and the initial alignment direction is parallel to the first direction.

15. The display device of claim 10, wherein the comblike electrodes include a plurality of first comblike electrodes extending from the connecting portion in the first direction and arranged along the second direction, and a plurality of second comblike electrodes extending from the connecting portion in the direction opposite to the first direction and arranged along the second direction.

16. The display device of claim 15, wherein the first comblike electrodes and the second comblike electrodes are symmetrical with respect to an axis parallel to the second direction.

17. The display device of claim 15, wherein the first comblike electrodes and the second comblike electrodes are arranged alternately in the second direction.

18. The display device of claim 10, wherein the first substrate is provided with a plurality of subpixels, the second electrode is provided over the plurality of subpixels and includes an aperture closed by the connecting portion, and the comblike electrodes are arranged in the aperture.