Method for manufacturing liquid crystal display device

Patent metadata

Field	Value
Publication number	US-2016178969-A1
Application number	US-201414907872-A
Country	US
Kind code	A1
Filing date	Jul 24, 2014
Priority date	Jul 30, 2013
Publication date	Jun 23, 2016
Grant date	—

Abstract

The present invention provides a method for manufacturing a liquid crystal display device including a photo-alignment film and capable of sufficiently improving the display quality. The method for manufacturing a liquid crystal display device of the present invention is a method for manufacturing a liquid crystal display device including a photo-alignment film. The method for manufacturing a liquid crystal display device successively includes a step (1) of forming on a substrate a film from a photo-alignment-film material that contains a solvent and a polymer including a photo-functional group that is capable of causing at least one chemical reaction selected from the group consisting of photodimerization, photoisomerization, and photo-Fries rearrangement; a step (2) of pre-heating the film to evaporate the solvent; a step (3) of irradiating the pre-heated film with polarized light; and a step (4) including an operation of main-heating the polarized-light-irradiated film at multiple temperatures from a lower temperature to a higher temperature. The liquid crystal display device is of an in-plane switching mode or a fringe field switching mode in each of which a pre-tilt angle is substantially 0°.

First claim

1 . A method for manufacturing a liquid crystal display device including a photo-alignment film,
the method for manufacturing a liquid crystal display device successively comprising: a step (1) of forming on a substrate a film from a photo-alignment-film material that contains a solvent and a polymer including a photo-functional group that is capable of causing at least one chemical reaction selected from the group consisting of photodimerization, photoisomerization, and photo-Fries rearrangement; a step (2) of pre-heating the film to evaporate the solvent; a step (3) of irradiating the pre-heated film with polarized light; and a step (4) including an operation of main-heating the polarized-light-irradiated film at multiple temperatures from a lower temperature to a higher temperature, the liquid crystal display device being of an in-plane switching mode or a fringe field switching mode in each of which a pre-tilt angle is substantially 0°.

2 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein the main heating in the step (4) is performed at a temperature of 90° C. or higher.

3 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein the pre-heating in the step (2) is performed at a temperature of 90° C. or lower.

4 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein the liquid crystal display device aligns liquid crystal molecules having negative anisotropy of dielectric constant by the photo-alignment film.

5 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein the main heating in the step (4) includes an operation performed so as to include multiple temperature-constant periods at different temperatures.

6 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein the main heating in the step (4) is performed at a temperature of 90° C. or higher and 140° C. or lower for one minute or longer, and at a temperature of 180° C. or higher.

7 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein the main heating in the step (4) is performed using multiple heaters set to different temperatures.

8 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein the main heating in the step (4) is performed using a single heater and the temperature of the heater is successively changed to a different temperature.

9 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein the main heating in the step (4) is performed by transferring the substrate in a heater that includes a region having a temperature gradient.

10 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein the photo-functional group is at least one functional group selected from the group consisting of a cinnamate group, a chalcone group, a coumarin group, a stilbene group, a phenyl ester group, and an azobenzene group.

11 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein the polymer including the photo-functional group includes a backbone that has at least one structure selected from the group consisting of polyamic acids, polyimides, acrylic structures, methacrylic structures, maleimide, and polysiloxanes.

12 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein the photo-alignment-film material further contains a polyamic acid.

13 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein the photo-functional group is capable of causing at least photodimerization, the step (4) includes two main heating operations at different temperatures and, between the first and second main heating operations, a step (4a) of irradiating the film after the first main heating with light.

14 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein a material of the polymer contained in the photo-alignment-film material includes in a main chain or a side chain a structure represented by any of the following formulas (1) to (3):

wherein X represents a direct bond, O, COO, OCO, CO, or C≡C.

15 . The method for manufacturing a liquid crystal display device according to claim 1 ,
wherein a material of the polymer contained in the photo-alignment-film material includes one or both of a carboxyl group and an amide group in a main chain or a side chain.

Assignees

• Sharp Kk

Inventors

• Miyake Isamu
• Miyachi Koichi
• ASAGI Hiroaki

Classifications

• G02F1/133788 Primary

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

• G02F1/133711

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

• G02F1/134372

  for fringe field switching [FFS] where the common electrode is not patterned · CPC title

• G02F1/134363

  for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS] · CPC title