Liquid crystal display device
View Patent ↗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.
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.