Liquid crystal display

Patent metadata

Field	Value
Publication number	US-9500917-B2
Application number	US-201313935184-A
Country	US
Kind code	B2
Filing date	Jul 3, 2013
Priority date	Mar 15, 2013
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

The present invention relates to a liquid crystal display including: a lower electrode including a unit pixel electrode; an upper electrode including an upper unit electrode facing the unit pixel electrode; and a liquid crystal layer between the lower electrode and the upper electrode and including a plurality of liquid crystal molecules aligned approximately perpendicular to the surfaces of the lower electrode and the upper electrode in the absence of an electric field, wherein the unit pixel electrode includes a stem forming a boundary between a plurality of sub-regions and a plurality of minute branches extending in different directions in two different sub-regions, the upper unit electrode includes an opening facing the stem and extending parallel to the stem, any alignment aid to pretilt the liquid crystal molecules is absent, and a length of the minute branches is equal to or less than about 53 μm.

First claim

What is claimed is:

1. A liquid crystal display comprising:
a substrate;
a first electrode disposed on the substrate and including at least one unit pixel electrode;
a second electrode including at least one unit electrode which faces the first electrode; and
a liquid crystal layer disposed between the first electrode and the second electrode and including a plurality of liquid crystal molecules aligned approximately perpendicular to a surface of the substrate in an absence of an electric field in the liquid crystal layer,
wherein a unit pixel electrode of the at least one the unit pixel electrodes include a stem disposed at a boundary between adjacent sub-regions and extending substantially in a first direction and a plurality of branches extending from the stem and disposed at the sub-regions, and the unit electrode includes an opening overlapping the stem in a plan view and extending substantially in the first direction, and
wherein the stem has a first width in a second direction substantially perpendicular to the first direction, the opening has a second width in the second direction, and the first width is equal to or smaller than the second width.

2. The liquid crystal display of claim 1 , wherein
the stem includes a cross-shaped stem, and
the unit pixel electrode includes a center pattern positioned at a center of the cross-shaped stem.

3. The liquid crystal display of claim 2 , wherein
the center pattern includes a polygon including a plurality of straight edges respectively positioned at the plurality of sub-regions and a vertex positioned on the stem.

4. The liquid crystal display of claim 3 , wherein
the opening includes a cross-shaped opening, and
the unit electrode includes a center opening positioned at a center of the cross-shaped opening.

5. The liquid crystal display of claim 4 , wherein
the center opening includes a polygon including a plurality of straight edges respectively positioned at the plurality of sub-regions.

6. The liquid crystal display of claim 4 , wherein
the center opening is smaller than the center pattern.

7. The liquid crystal display of claim 1 , wherein,
when the first electrode includes a plurality of unit pixel electrodes and the second electrode includes a plurality of unit electrodes,
the plurality of unit pixel electrodes are connected to each other via at least one first connection which is aligned with the stem, and
the plurality of unit electrodes are connected to each other a via at least one second connection which is aligned with the opening.

8. The liquid crystal display of claim 7 , wherein
the liquid crystal display comprises a plurality of pixels, one pixel of the plurality of pixels includes a first sub-pixel and a second sub-pixel which display images having luminances that are equal to each other or different from each other for one input image signal,
each of the first sub-pixel and the second sub-pixel includes the first electrode and the second electrode, and
a number of the at least one unit pixel electrode included in the second sub-pixel is larger than a number of the at least one unit pixel electrode included in the first sub-pixel.

9. The liquid crystal display of claim 8 , wherein
a width of a first transverse gap extending in a horizontal direction and extending between adjacent ones of the unit pixel electrodes of the first sub-pixel is smaller than a width of a first longitudinal gap extending in a vertical direction and extending between adjacent ones of the unit pixel electrodes of the first sub-pixel, and
a width of a second transverse gap extending in the horizontal direction and extending between the unit pixel electrodes of the second sub-pixel is larger than a width of a second longitudinal gap extending in the vertical direction and extending between the unit pixel electrodes of the second sub-pixel.

10. The liquid crystal display of claim 9 , wherein
a width of a first transverse opening extending in the horizontal direction of the unit electrode included in the first sub-pixel is smaller than a width of a first longitudinal opening extending in the vertical direction of the unit electrode included in the first sub-pixel, and
a width of a second transverse opening extending in the horizontal direction of the unit electrode included in the second sub-pixel is larger than a width of a second longitudinal opening extending in the vertical direction of the unit electrode included in the second sub-pixel.

11. The liquid crystal display of claim 10 , further comprising:
a first connection which connects between ends of the branches positioned respectively at an upper end and a lower end of the first electrode of the first sub-pixel; and
a second connection which connects between ends of the branches positioned respectively at a left end and a right end of the first electrode of the second sub-pixel.

12. The liquid crystal display of claim 11 , wherein
an angle between an extending direction of the branches included in the first electrode of the first sub-pixel and the horizontal direction is smaller than substantially 45 degrees.

13. The liquid crystal display of claim 1 , wherein:
the opening includes a cross-shaped opening; and
the unit electrode includes a center opening positioned at the center of the cross-shaped opening.

14. The liquid crystal display of claim 13 , wherein
the center opening includes a polygon including a plurality of straight edges respectively positioned at the plurality of sub-regions.

15. The liquid crystal display of claim 14 , wherein
the center opening is smaller than the center pattern.

16. The liquid crystal display of claim 1 , wherein:
the liquid crystal display comprises a plurality of pixels, one pixel of the plurality of pixels includes a first sub-pixel and a second sub-pixel which display images having luminances that are equal to each other or different from each other for one input image signal,
each of the first sub-pixel and the second sub-pixel includes the first electrode and the second electrode; and
a number of the at least one unit pixel electrode included in the second sub-pixel is larger than a number of the at least one unit pixel electrode included in the first sub-pixel.

17. The liquid crystal display of claim 16 , wherein
a width of a first transverse gap extending in a horizontal direction and extending between adjacent ones of the unit pixel electrodes of the first sub-pixel is smaller than a width of a first longitudinal gap extending in a vertical direction and extending between adjacent ones of the unit pixel electrodes of the first sub-pixel, and
a width of a second transverse gap extending in the horizontal direction and extending between the unit pixel electrodes of the second sub-pixel is larger than a width of a second longitudinal gap extending in the vertical direction and extending between the unit pixel electrodes of the second sub-pixel.

18. The liquid crystal display of claim 16 , wherein
a width of a first transverse opening extending in the horizontal direction of the unit electrode included in the first sub-pixel is smaller than a width of a first longitudinal opening extending in the vertical direction of the unit electrode included in the first sub-pixel, and
a width of a second transverse opening extending in the horizontal direction of the unit electrode included in the second sub-pixel is larger than a width of a second longitudinal opening extending in the vertical direction of the unit electrode included in the second sub-pixel.

Assignees

• Samsung Display Co Ltd

Inventors

• Ryu Jang Wi
• Shin Cheol
• Chang Hak Sun
• Shin Ki Chul
• Jang Jae-Soo
• Kim Ka Eun
• Oh Ho Kil
• Lee Se Hyun
• Jung Hyo Ju
• Song Sang Hyeon
• Jeon Sang Jin

Classifications

• G02F2203/04

  wavelength independent · CPC title

• G02F1/133707 Primary

  Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes · CPC title

• G02F1/133345

  Insulating layers (G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence) · CPC title

• G02F1/1393

  the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells (G02F1/1396, G02F1/141 take precedence) · CPC title

• G02F1/13439 Primary

  characterised by their electrical, optical, physical properties; materials therefor; method of making · CPC title