Liquid crystal display device

Patent metadata

Field	Value
Publication number	US-9841633-B2
Application number	US-201514922377-A
Country	US
Kind code	B2
Filing date	Oct 26, 2015
Priority date	Mar 2, 2011
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

In the step of curing a resin for bonding a TFT substrate and a counter substrate each having an alignment film that has been optically aligned by using UV-light, damage to the alignment film due to the UV-light can be prevented without using a light shielding mask. A UV-light absorption layer is formed between each black matrix on the counter substrate. The TFT and counter substrates are sealed at their periphery by a resin that is cured by UV-light radiated from the counter substrate side. Since the absorption layer has a high absorbability to UV-light at a wavelength of 300 nm or less that degrades the alignment film, damage to the alignment film due to the UV-light for curing the resin can be prevented. Thus, provision of a light shielding mask for shielding the UV-light for the display region can be saved.

First claim

What is claimed is:

1. A liquid crystal display device comprising:
a TFT substrate having a first alignment film;
a counter substrate having a second alignment film, the counter substrate being bonded to the TFT substrate by a seal material; and
liquid crystals sealed inside the substrates and the seal material;
wherein the counter substrate has a UV-light absorption layer,
the second alignment film is optically aligned by UV-light, and the second alignment film is optically alignable by UV-light having a wavelength of 300 nm or less,
the second alignment film is formed between the UV-light absorption layer and the liquid crystals,
the seal material is a UV-light curable resin curable by UV-light having a wavelength of 340 nm or more, and
the transmittance of the UV-light absorption layer to UV-light at a wavelength of 300 nm is lower than that to UV-light at a wavelength of 340 nm,
wherein the UV-light absorption layer has a transmittance to UV-light at a wavelength of about 340 nm or more, of about 90% or more, and a transmittance to UV-light at a wavelength of about 300 nm or less, of about 10% or less,
wherein the TFT substrate and the counter substrate form a first pixel,
the TFT substrate has a pixel electrode and does not have a color filter at an area of the TFT substrate corresponding to the first pixel, and
the counter substrate has the UV-light absorption layer and does not have a color filter at an area of the counter substrate corresponding to the first pixel, but has the UV-light absorption layer at the same area of the counter substrate corresponding to the first pixel.

2. The liquid crystal display device according to claim 1 ,
wherein an overcoat layer is formed between the UV-light absorption layer and the second alignment layer,
the transmittance of the UV-light absorption layer to UV-light at a wavelength of 300 nm is lower than that of the overcoat film, and the transmittance of the UV-light absorption layer to UV-light at a wavelength of 340 nm is higher than that of the overcoat film.

3. The liquid crystal display device according to claim 2 ,
wherein the TFT substrate has an organic passivation film formed between the TFT substrate and the first alignment film,
the first alignment film is optically aligned by UV-light,
the transmittance of the UV-light absorption layer to UV-light at a wavelength of 300 nm is lower than that of the organic passivation film, and
the transmittance of the UV-light absorption layer to UV-light at a wavelength of 340 nm is higher than that of the organic passivation film.

4. A liquid crystal display device comprising:
a TFT substrate having a first alignment film;
a counter substrate having a second alignment film, the counter substrate being bonded to the TFT substrate by a seal material; and
liquid crystals sealed inside the substrates and the seal material;
wherein the counter substrate has a UV-light absorption layer,
the second alignment film is optically aligned by UV-light, and the second alignment film is optically alignable by UV-light having a wavelength of 300 nm or less,
the second alignment film is formed between the UV-light absorption layer and the liquid crystals,
the seal material is a UV-light curable resin curable by UV-light having a wavelength of 340 nm or more,
an overcoat layer is formed between the UV-light absorption layer and the second alignment layer, and
the transmittance of the UV-light absorption layer to UV-light at a wavelength of 300 nm is lower than that of the overcoat film, and the transmittance of the UV-light absorption layer to UV-light at a wavelength of 340 nm is higher than that of the overcoat film,
wherein the UV-light absorption layer has a transmittance to UV-light at a wavelength of about 340 nm or more, of about 90% or more, and a transmittance to UV-light at a wavelength of about 300 nm or less, of about 10% or less,
wherein the TFT substrate and the counter substrate form a first pixel,
the TFT substrate has a pixel electrode and does not have a color filter at an area of the TFT substrate corresponding to the first pixel, and
the counter substrate has the UV-light absorption layer and does not have a color filter at an area of the counter substrate corresponding to the first pixel, but has the UV-light absorption layer at the same area of the counter substrate corresponding to the first pixel.

5. The liquid crystal display device according to claim 4 ,
wherein the TFT substrate has an organic passivation film formed between the TFT substrate and the first alignment film,
the first alignment film is optically aligned by UV-light,
the transmittance of the UV-light absorption layer to UV-light at a wavelength of 300 nm is lower than that of the organic passivation film, and
the transmittance of the UV-light absorption layer to UV-light at a wavelength of 340 nm is higher than that of the organic passivation film.

6. The liquid crystal display device according to claim 4 ,
wherein the liquid crystal display device is a monochromatic liquid crystal display device.

Assignees

• Japan Display Inc

Inventors

• Kunimatsu Noboru
• Matsumoto Yuko
• Tomioka Yasushi
• Morimoto Masateru
• Katayama Atsuhiro

Classifications

• G02B5/208

  for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation · CPC title

• G02F1/133509

  Filters, e.g. light shielding masks · CPC title

• G02F1/1337

  Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers · CPC title

• G02F1/1368

  in which the switching element is a three-electrode device {(G02F1/136277 takes precedence)} · CPC title

• G02F1/133788 Primary

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