Liquid crystal display apparatus

Patent metadata

Field	Value
Publication number	US-12313939-B2
Application number	US-202418594517-A
Country	US
Kind code	B2
Filing date	Mar 4, 2024
Priority date	Apr 20, 2023
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

Each pixel includes first through fourth liquid crystal domains. The first through fourth liquid crystal domains are arranged in this order along the pixel longitudinal direction. The reference alignment direction of the second liquid crystal domain and the reference alignment direction of the third liquid crystal domain are respectively essentially the 135° direction and essentially the 315° direction, or respectively essentially the 45° direction and essentially the 225° direction. The pixel electrode includes a first through fourth slitted regions corresponding to the first through fourth liquid crystal domains, and a boundary region located between the second and third slitted regions. The boundary region includes n boundary slits (where n≥3) extending essentially in parallel to the pixel transverse direction; (n-1) first bridging portions each located between two adjacent boundary slits; and (n-2) dent patterns each located between two adjacent first bridging portions.

First claim

What is claimed is:

1. A liquid crystal display apparatus comprising:
a first substrate and a second substrate positioned opposite each other; and
a liquid crystal layer of a vertical alignment type interposed between the first substrate and the second substrate, wherein:
the liquid crystal display apparatus has a plurality of pixels,
the first substrate includes a pixel electrode provided in each of the plurality of pixels, and a first alignment film is provided between the pixel electrode and the liquid crystal layer,
the second substrate includes a counter electrode opposite the pixel electrode, and a second alignment film provided between the counter electrode and the liquid crystal layer,
each of the plurality of pixels includes a first liquid crystal domain, a second liquid crystal domain, a third liquid crystal domain, and a fourth liquid crystal domain, each of the first to fourth liquid crystal domains having a reference alignment direction defined by the first alignment film and the second alignment film, and the first to fourth liquid crystal domains having respectively different reference alignment directions,
a longitudinal direction and a transverse direction of each of the plurality of pixels respectively define a pixel longitudinal direction and a pixel transverse direction of that pixel, and the reference alignment directions of the first liquid crystal domain, the second liquid crystal domain, the third liquid crystal domain, and the fourth liquid crystal domain respectively define a first direction, a second direction, a third direction, and a fourth direction,
the first direction, the second direction, the third direction, and the fourth direction, each makes an angle, which is essentially equal to an odd multiple of 45°, with respect to the pixel transverse direction of each pixel,
the first liquid crystal domain, the second liquid crystal domain, the third liquid crystal domain, and the fourth liquid crystal domain are arranged in this order along the pixel longitudinal direction of the pixel,
the second direction and the third direction are respectively essentially the 135° direction and essentially the 315° direction, or are respectively essentially the 45° direction and essentially the 225° direction, wherein an azimuth angle of the pixel transverse direction is defined as 0°;
the pixel electrode includes:
a first slitted region which is a region corresponding to the first liquid crystal domain, and in which a plurality of first slits extending essentially in parallel to the first direction is formed,
a second slitted region which is a region corresponding to the second liquid crystal domain, and in which a plurality of second slits extending essentially in parallel to the second direction is formed,
a third slitted region which is a region corresponding to the third liquid crystal domain, and in which a plurality of third slits extending essentially in parallel to the third direction is formed,
a fourth slitted region which is a region corresponding to the fourth liquid crystal domain, and in which a plurality of fourth slits extending essentially in parallel to the fourth direction is formed, and
a boundary region located between the second slitted region and the third slitted region, and

the boundary region includes:
n boundary slits, where n is an integer equal to or greater than 3, each boundary slit extending essentially in parallel to the pixel transverse direction, the n boundary slits being arranged along the pixel transverse direction,
(n-1) first bridging portions each being located between two adjacent boundary slits among the n boundary slits, the (n-1) first bridging portions interconnecting the second slitted region and the third slitted region, and
(n-2) dent patterns each being located between two adjacent first bridging portions, among the (n-1) first bridging portions, and each including a first dent formed so as to be dented into the second slitted region from a boundary slit that is located between the two first bridging portions, and a second dent formed so as to be dented into the third slitted region from the boundary slit that is located between the two first bridging portions.

2. The liquid crystal display apparatus of claim 1 , wherein a distance from each of the (n-2) dent patterns to each of two first bridging portions that are adjacent to the dent pattern is not less than 10 μm and not more than 30 μm.

3. The liquid crystal display apparatus of claim 1 , wherein a width of each of the (n-1) first bridging portions along the pixel transverse direction is not less than 2.5 μm and not more than 3.5 μm.

4. The liquid crystal display apparatus of claim 1 , wherein a length of each of the first dent and the second dent, along the pixel longitudinal direction, is 1.5 μm or more.

5. The liquid crystal display apparatus of claim 1 , wherein the boundary region further includes two second bridging portions being located at opposite ends of the pixel electrode, along the pixel transverse direction, and interconnects the second slitted region and the third slitted region.

6. The liquid crystal display apparatus of claim 5 , wherein a width of each of the two second bridging portions, along the pixel transverse direction, is 6.0 μm or more.

7. The liquid crystal display apparatus of claim 1 , wherein each of the first alignment film and the second alignment film is a photo-alignment film.

8. The liquid crystal display apparatus of claim 1 , wherein, in each of the first liquid crystal domain, the second liquid crystal domain, the third liquid crystal domain, and the fourth liquid crystal domain, a pretilt direction that is defined by the first alignment film and a pretilt direction that is defined by the second alignment film are essentially antiparallel.

9. A liquid crystal display apparatus comprising:
a first substrate and a second substrate positioned opposite each other; and
a liquid crystal layer of a vertical alignment type interposed between the first substrate and the second substrate, wherein:
the liquid crystal display apparatus has a plurality of pixels,
the first substrate includes a pixel electrode provided in each of the plurality of pixels, and a first alignment film is provided between the pixel electrode and the liquid crystal layer,
the second substrate includes a counter electrode opposite the pixel electrode, and a second alignment film provided between the counter electrode and the liquid crystal layer,
each of the plurality of pixels includes a first liquid crystal domain, a second liquid crystal domain, a third liquid crystal domain, and a fourth liquid crystal domain, each of the first to fourth liquid crystal domains having a reference alignment direction defined by the first alignment film and the second alignment film, and the first to fourth liquid crystal domains having respectively different reference alignment directions,
a longitudinal direction and a transverse direction of each of the plurality of pixels respectively define a pixel longitudinal direction and a pixel transverse direction of that pixel, and the reference alignment directions of the first liquid crystal domain, the second liquid crystal domain, the third liquid crystal domain, and the fourth liquid crystal domain respectively define a first direction, a second direction, a third direction, and a fourth direction,
the first direction, the second direction, the third direction, and the fourth direction, each makes an angle, which is essentially equal to an odd multiple of 45°, with respect to the pixel transverse direction of each pixel,
the first liquid crystal domain, the second liquid crystal domain, the third liquid crystal domain, and the fourth liquid crystal domain ar

Assignees

• Sakai Display Products Corp

Inventors

• Hirata Mitsuaki

Classifications

• G02F1/134309

  characterised by their geometrical arrangement · CPC title

• G02F1/133757

  with different alignment orientations · CPC title

• G02F1/134345

  Subdivided pixels, e.g. for grey scale or redundancy · 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

• G02F1/133707 Primary

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