Vertically aligned liquid crystal display
A vertically aligned liquid crystal display (VA-LCD) according to one embodiment has liquid crystal cells in which liquid crystals with a negative dielectric anisotropy are filled and which is provided between a first polarizer and a second polarizer, whose absorption axes are perpendicular to each other. The VA-LCD includes a sheet of +A plate and a sheet of −C plate, disposed between the first polarizer and the liquid crystal cells, and a sheet of +A plate disposed between the second polarizer and the liquid crystal cells, where an optical axis of the +A plate near the first polarizer is perpendicular to the absorption axis of the first polarizer, and an optical axis of the +A plate near the second polarizer is parallel with the absorption axis of the second polarizer, and where a thickness retardation value of the −C plate is in the range of −500 nm to −30 nm for a wavelength of 550 nm.
1. A vertically aligned liquid crystal display (VA-LCD) having liquid crystal cells in which liquid crystals with a negative dielectric anisotropy are filled and which is provided between a first polarizer and a second polarizer, whose absorption axises are perpendicular to each other, comprising:
a sheet of +A plate and a sheet of −C plate, disposed between the first polarizer and the liquid crystal cells; and
a sheet of +A plate disposed between the second polarizer and the liquid crystal cells,
wherein an optical axis of the +A plate near the first polarizer is perpendicular to the absorption axis of the first polarizer, and an optical axis of the +A plate near the second polarizer is parallel with the absorption axis of the second polarizer, and
wherein a thickness retardation value of the −C plate is in the range of −500 nm to −30 nm for a wavelength of 550 nm.
2. The VA-LCD according to claim 1 , wherein an in-plane retardation value of the +A plate near the first polarizer is in the range of 50 nm to 300 nm for a wavelength of 550 nm.
3. The VA-LCD according to claim 1 , wherein an in-plane retardation value of the +A plate near the second polarizer is in the range of 30 to 600 nm for a wavelength of 550 nm.
4. The VA-LCD according to claim 1 , wherein the first polarizer and the second polarizer respectively have an inner protective film, and the inner protective films of the first polarizer and the second polarizer have zero or a negative value of thickness retardation.
5. The VA-LCD according to claim 1 , the +A plate comprises a polymer film or a UV setting liquid crystal film.
6. The VA-LCD according to claim 1 , wherein the −C plate comprises a polymer film or a UV setting liquid crystal film.
7. The VA-LCD according to claim 1 , wherein the first polarizer and the second polarizer respectively have an inner protective film, and the inner protective films of the first polarizer and the second polarizer comprise undrawn cyclo-olefin, undrawn triacetate cellulose, or undrawn polynorbonene.
8. The VA-LCD according to claim 1 , wherein the VA-LCD uses a multidomain vertically aligned (MVA) mode or a vertically aligned (VA) mode which utilizes a chiral additive, and a cell gap of the liquid crystal cells is 2.5 to 8 μm.
9. A VA-LCD having liquid crystal cells in which liquid crystals with a negative dielectric anisotropy are filled and which are disposed between a first polarizer and a second polarizer, whose absorption axises are perpendicular to each other, comprising:
a bi-axial retardation film disposed between the first polarizer and the liquid crystal cells; and
a sheet of +A plate disposed between the second polarizer and the liquid crystal cells,
wherein an optical axis of the bi-axial retardation film near the first polarizer is perpendicular to the absorption axis of the first polarizer, and an optical axis of the +A plate is parallel with the absorption axis of the second polarizer, and
wherein the bi-axial retardation film has an in-plane retardation value in the range of 30 to 200 nm and a thickness retardation value in the range of −300 nm to −50 nm for a wavelength of 550 nm.
10. The VA-LCD according to claim 9 , wherein an in-plane retardation value of the +A plate near the second polarizer is in the range of 30 to 600 nm for a wavelength of 550 nm.
11. The VA-LCD according to claim 9 , wherein the +A plate functions as an inner protective film of the polarizer.
12. The VA-LCD according to claim 9 , wherein the bi-axial retardation film functions as an inner protective film of the polarizer.
13. The VA-LCD according to claim 9 , wherein the bi-axial retardation film is one of cyclo-olefin, drawn triacetate cellulose, drawn polynorbonene and bi-axial liquid crystal film.
14. The VA-LCD according to claim 9 wherein the first polarizer and the second polarizer respectively have an inner protective film, and the inner protective films of the first polarizer and the second polarizer have zero or a negative value of thickness retardation.
15. The VA-LCD according to claim 9 , the +A plate comprises a polymer film or a UV setting liquid crystal film.
16. The VA-LCD according to claim 9 , wherein the −C plate comprises a polymer film or a UV setting liquid crystal film.
17. The VA-LCD according to claim 9 , wherein the first polarizer and the second polarizer respectively have an inner protective film, and the inner protective films of the first polarizer and the second polarizer comprise undrawn cyclo-olefin, undrawn triacetate cellulose, or undrawn polynorbonene.
18. The VA-LCD according to claim 9 , wherein the VA-LCD uses a multidomain vertically aligned (MVA) mode or a vertically aligned (VA) mode which utilizes a chiral additive, and a cell gap of the liquid crystal cells is 2.5 to 8 μm.