Liquid crystal display and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-11391992-B2
Application number	US-201815981032-A
Country	US
Kind code	B2
Filing date	May 16, 2018
Priority date	Aug 22, 2017
Publication date	Jul 19, 2022
Grant date	Jul 19, 2022

Abstract

A liquid crystal display includes: a first substrate; a second substrate overlapping the first substrate and spaced apart therefrom; a liquid crystal layer between the first substrate and the second substrate and including liquid crystal molecules; a first alignment layer between the first substrate and the liquid crystal layer; and a plurality of protrusions between the first alignment layer and the liquid crystal layer, wherein the first alignment layer includes a photoinitiator, wherein the plurality of protrusions include a polymerization product of the photoinitiator, a reactive mesogen, and a vertical alignment additive, and the vertical alignment additive may be less reactive than the photoinitiator.

First claim

What is claimed is:

1. A liquid crystal display comprising:
a first substrate;
a second substrate overlapping the first substrate and spaced apart therefrom;
a liquid crystal layer between the first substrate and the second substrate, and comprising liquid crystal molecules and a vertical alignment additive;
a first alignment layer between the first substrate and the liquid crystal layer; and
a plurality of protrusions between the first alignment layer and the liquid crystal layer,
wherein the first alignment layer comprises a photoinitiator,
wherein the plurality of protrusions comprise a polymerization product of the photoinitiator, a reactive mesogen, and the vertical alignment additive, and the vertical alignment additive is less reactive than the photoinitiator in a wavelength range of 300 nanometers to 350 nanometers,
wherein the vertical alignment additive is one or more of compounds represented by Chemical Formulas 1 to 5:

2. The liquid crystal display of claim 1 , wherein the photoinitiator is benzophenone.

3. The liquid crystal display of claim 1 , wherein no protrusion of the plurality of protrusions is present between the second substrate and the liquid crystal layer.

4. The liquid crystal display of claim 1 , wherein
the liquid crystal molecules adjacent to the second substrate are aligned at an angle perpendicular to the second substrate.

5. The liquid crystal display of claim 4 , wherein
a difference between the pretilt angle of the liquid crystal molecules adjacent to the first substrate and the pretilt angle of the liquid crystal molecules adjacent to the second substrate is 0.2 degree or greater.

6. The liquid crystal display of claim 1 , wherein the vertical alignment additive is a compound represented by Chemical Formula 1:

7. A liquid crystal display comprising:
a first substrate;
a second substrate overlapping the first substrate and spaced apart therefrom;
a liquid crystal layer between the first substrate and the second substrate and comprising liquid crystal molecules and a vertical alignment additive;
a first alignment layer positioned between the first substrate and the liquid crystal layer; and
a plurality of protrusions between the first alignment layer and the liquid crystal layer,
wherein the first alignment layer comprises a photoinitiator,
wherein the plurality of protrusions comprise a polymerization product of the photoinitiator, a reactive mesogen, and the vertical alignment additive,
wherein an alignment layer is not present between the second substrate and the liquid crystal layer, and
wherein the vertical alignment additive is one or more of compounds represented by Chemical Formulas 1 to 5:

8. The liquid crystal display of claim 7 , wherein the vertical alignment additive is less reactive than the photoinitiator in a wavelength range of 300 nanometers to 350 nanometers.

9. The liquid crystal display of claim 7 , wherein the liquid crystal display has a curved shape.

10. The liquid crystal display of claim 7 , wherein the photoinitiator is benzophenone.

11. The liquid crystal display of claim 7 , wherein
no protrusion of the plurality of protrusions is present between the second substrate and the liquid crystal layer.

12. The liquid crystal display of claim 7 , wherein
liquid crystal molecules adjacent to the first substrate are aligned at a pretilt angle, and
liquid crystal molecules adjacent to the second substrate are aligned at an angle perpendicular to the second substrate.

13. The liquid crystal display of claim 12 , wherein
a difference between the pretilt angle of the liquid crystal molecules adjacent to the first substrate and the angle of the liquid crystal molecules adjacent to the second substrate is 0.2 degree or greater.

14. A method of manufacturing a liquid crystal display, comprising:
providing a first substrate comprising a first alignment layer comprising a photoinitiator;
providing a second substrate overlapping the first substrate;
forming a liquid crystal layer comprising a plurality of liquid crystal molecules, a reactive mesogen, and a vertical alignment additive between the first substrate and the second substrate, wherein the vertical alignment additive is less reactive than the photoinitiator in a wavelength range of 300 nanometers to 350 nanometers;
irradiating ultraviolet light toward the first substrate and the second substrate; and,
polymerizing the photoinitiator, the reactive mesogen, and the vertical alignment additive to form the liquid crystal display,
wherein the first alignment layer includes a photoinitiator,
wherein the photoinitiator, the reactive mesogen, and the vertical alignment additive are polymerized by the ultraviolet light to form a plurality of protrusions on the first alignment layer,
wherein the liquid crystal display is a curved liquid crystal display, and
wherein the vertical alignment additive is one or more of compounds represented by Chemical Formulas 1 to 5:

15. The method of manufacturing the liquid crystal display of claim 14 , wherein the photoinitiator is benzophenone.

16. The method of manufacturing the liquid crystal display of claim 14 , wherein a content of the vertical alignment additive is about 0.1 weight percent to about 3 weight percent based on the total weight of the liquid crystal layer.

17. The method of manufacturing the liquid crystal display of claim 14 , wherein
after the irradiating of the ultraviolet light,
liquid crystal molecules adjacent to the first substrate are aligned at a pretilt angle, and
liquid crystal molecules adjacent to the second substrate are aligned at an angle perpendicular to the second substrate.

18. The method of manufacturing the liquid crystal display of claim 17 , wherein
a difference between the pretilt angle of the liquid crystal molecules adjacent to the first substrate and the angle of the liquid crystal molecules adjacent to the second substrate is 0.2 degree or greater.

19. The method of manufacturing the liquid crystal display of claim 14 , wherein the vertical alignment additive is a compound represented by Chemical Formula 1:

20. The method of manufacturing the liquid crystal display of claim 14 , wherein a central wavelength of the ultraviolet light is about 300 nanometers to about 350 nanometers.

Assignees

• Samsung Display Co Ltd

Inventors

• Kwon Oh Jeong
• Kim Ka Eun
• Kim Tae Min
• Suh Duck Jong
• Seo Bong-Sung
• Lee Seul Gee

Classifications

• G02F1/133776

  having structures locally influencing the alignment, e.g. unevenness · CPC title

• G02F2202/022

  polymeric · CPC title

• G02F1/133707 Primary

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

• G02F1/133749

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

• G02F1/133757

  with different alignment orientations · CPC title