Liquid crystal display panel, method for manufacturing liquid crystal display panel, and curved display

Patent metadata

Field	Value
Publication number	US-11960172-B2
Application number	US-202117435135-A
Country	US
Kind code	B2
Filing date	Jul 13, 2021
Priority date	Jun 16, 2021
Publication date	Apr 16, 2024
Grant date	Apr 16, 2024

Abstract

The present application discloses a liquid crystal display panel, a method for manufacturing the liquid crystal display panel, and a curved display. The liquid crystal display panel is configured with an alignment layer only on an array substrate, but not on an opposing substrate opposite to the array substrate. After photo-alignment, a pretilt angle of liquid crystal molecules near the array substrate is greater than a pretilt angle of liquid crystal molecules near the opposing substrate to effectively mitigate a problem of “black clusters.”

First claim

What is claimed is:

1. A liquid crystal display panel, comprising:
an array substrate;
an opposing substrate disposed opposite to the array substrate;
a liquid crystal layer made of a self-alignment liquid crystal material and disposed between the array substrate and the opposing substrate, wherein the liquid crystal layer comprises first liquid crystal molecules and second liquid crystal molecules, the first liquid crystal molecules are located on a side of the liquid crystal layer near the array substrate, and the second liquid crystal molecules are located on a side of the liquid crystal layer near the opposing substrate; and
an alignment layer only disposed on a side of the array substrate near the liquid crystal layer;
wherein an acute angle between a major axis of the first liquid crystal molecules and a vertical direction is a first pretilt angle, an acute angle between a major axis of the second liquid crystal molecules and the vertical direction is a second pretilt angle, and the first pretilt angle is greater than the second pretilt angle.

2. The liquid crystal display panel of claim 1 , wherein a difference in degrees between the first pretilt angle and the second pretilt angle is greater than 1.8 degrees.

3. The liquid crystal display panel of claim 2 , wherein the first pretilt angle is between 2.4 degrees and 4 degrees, and the second pretilt angle is between 0 degrees and 0.6 degrees.

4. The liquid crystal display panel of claim 1 , wherein the self-alignment liquid crystal material comprises liquid crystal molecules, vertical aligning agents, and reactive monomers, wherein the vertical aligning agents comprise a structure as shown by formula (1):

and the reactive monomers comprise a structure as shown by formula (2):

5. The liquid crystal display panel of claim 4 , wherein a mass fraction of the vertical aligning agents to the self-alignment liquid crystal material is between 0.3% and 0.6%, and a mass concentration of the reactive monomers in the self-alignment liquid crystal material is between 2000 parts per million (ppm) and 3000 ppm.

6. The liquid crystal display panel of claim 1 , wherein the alignment layer is made of polyimide compounds having a main chain based on imides, and the polyimide compounds has a side chain comprising reactive functional groups.

7. The liquid crystal display panel of claim 6 , wherein the reactive functional groups comprise at least one of unsaturated double bonds, unsaturated triple bonds, hydroxy groups, or amino groups.

8. A method for manufacturing a liquid crystal display panel,
comprising steps as follows:
providing an array substrate, an opposing substrate, and a self-alignment liquid crystal material, wherein the array substrate and the opposing substrate are disposed opposite to each other;
forming an alignment layer on a side of the array substrate near the opposing substrate;
injecting the self-alignment liquid crystal material between the array substrate and the opposing substrate; and
aligning the self-alignment liquid crystal material to form a liquid crystal layer, wherein the liquid crystal layer comprises first liquid crystal molecules and second liquid crystal molecules, the first liquid crystal molecules are located on a side of the liquid crystal layer near the array substrate, the second liquid crystal molecules are located on a side of the liquid crystal layer near the opposing substrate, an acute angle between a major axis of the first liquid crystal molecules and a vertical direction is a first pretilt angle, and an acute angle between a major axis of the second liquid crystal molecules and the vertical direction is a second pretilt angle;
wherein the first pretilt angle is greater than the second pretilt angle.

9. The method for manufacturing the liquid crystal display panel of claim 8 , wherein the step of aligning the self-alignment liquid crystal material to form the liquid crystal layer comprises: irradiating the self-alignment liquid crystal material by ultraviolet light to facilitate an angular velocity of the first pretilt angle to be faster than an angular velocity of the second pretilt angle.

10. The method for manufacturing the liquid crystal display panel of claim 9 , wherein irradiating the self-alignment liquid crystal material by the ultraviolet light is performed under conditions of a light wavelength between 270 nanometers and 380 nanometers, and a light intensity between 0.5 milliwatts per square centimeter and 0.7 milliwatts per square centimeter.

11. The method for manufacturing the liquid crystal display panel of claim 10 , wherein a difference between the angular velocity of the first pretilt angle and the angular velocity of the second pretilt angle is greater than or equal to 30 seconds per degree.

12. The method for manufacturing the liquid crystal display panel of claim 11 , wherein the self-alignment liquid crystal material is irradiated by the ultraviolet light with a light wavelength of 313 nanometers and the light intensity of 0.5 milliwatts per square centimeter to make the angular velocity of the first pretilt angle faster than or equal to 40 seconds per degree and the angular velocity of the second pretilt angle slower than or equal to 70 seconds per degree.

13. A curved display, comprising:
a liquid crystal display panel; and
a backlight module disposed on a side of the liquid crystal display panel away from a light output side;
wherein the liquid crystal display panel comprises:
an array substrate;
an opposing substrate disposed opposite to the array substrate;
a liquid crystal layer made of a self-alignment liquid crystal material and disposed between the array substrate and the opposing substrate, wherein the liquid crystal layer comprises first liquid crystal molecules and second liquid crystal molecules, the first liquid crystal molecules are located on a side of the liquid crystal layer near the array substrate, and the second liquid crystal molecules are located on a side of the liquid crystal layer near the opposing substrate; and
an alignment layer only disposed on a side of the array substrate near the liquid crystal layer;
wherein an acute angle between a major axis of the first liquid crystal molecules and a vertical direction is a first pretilt angle, an acute angle between a major axis of the second liquid crystal molecules and the vertical direction is a second pretilt angle, and the first pretilt angle is greater than the second pretilt angle.

14. The curved display of claim 13 , wherein a difference in degrees between the first pretilt angle and the second pretilt angle is greater than 1.8 degrees.

15. The curved display of claim 14 , wherein the first pretilt angle is between 2.4 degrees and 4 degrees, and the second pretilt angle is between 0 degrees and 0.6 degrees.

16. The curved display of claim 13 , wherein the self-alignment liquid crystal material comprises liquid crystal molecules, vertical aligning agents, and reactive monomers, wherein the vertical aligning agents comprise a structure as shown by formula (1):

and the reactive monomers comprise a structure as shown by formula (2):

17. The curved display of

Assignees

• Huizhou China Star Optoelectronics Display Co Ltd
• Tcl China Star Optoelectronics Tech Co Ltd

Inventors

• Yu Liang
• Zheng Feng

Classifications

• G02F1/133788 Primary

  by light irradiation, e.g. linearly polarised light photo-polymerisation · CPC title

• G02F1/133723 Primary

  Polyimide, polyamide-imide · CPC title

• G02F1/133749

  for low pretilt angles, i.e. lower than 15 degrees · CPC title

• G02F1/133761

  with different pretilt angles · CPC title

• G02F1/133711 Primary

  by organic films, e.g. polymeric films · CPC title