Quarter wave plate comprising two optically anisotropic layers
First Claim
1. A quarter wave plate comprising an optically anisotropic layer A and an optically anisotropic layer B, said optically anisotropic layer A having a retardation value in the range of 210 to 300 nm when the retardation value is measured at the wavelength of 550 nm, and said optically anisotropic layer B having a retardation valve in the range of 115 to 150 nm when the retardation value is measured at the wavelength of 550 nm, said quarter wave plate having a ratio of a retardation value to a wavelength in the range of 0.2 to 0.3 when the retardation value is measured at the wavelength of 450 nm, 550 nm and 650 nm, wherein one of the optically anisotropic layers A and B is a layer made from liquid crystal molecules, and the other is a polymer film.
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Accused Products
Abstract
A circularly polarizing plate comprises a linearly polarizing membrane and a quarter wave plate. The quarter wave plate comprises an optically anisotropic layer A and an optically anisotropic layer B. The quarter wave plate has such an optical characteristic that a retardation value essentially is a quarter of a wavelength when the retardation value is measured at the wavelength of 450 nm, 550 nm and 650 nm. One of the optically anisotropic layers A and B is a layer made from liquid crystal molecules, and the other is a polymer film or a layer made from liquid crystal molecules.
20 Citations
33 Claims
- 1. A quarter wave plate comprising an optically anisotropic layer A and an optically anisotropic layer B, said optically anisotropic layer A having a retardation value in the range of 210 to 300 nm when the retardation value is measured at the wavelength of 550 nm, and said optically anisotropic layer B having a retardation valve in the range of 115 to 150 nm when the retardation value is measured at the wavelength of 550 nm, said quarter wave plate having a ratio of a retardation value to a wavelength in the range of 0.2 to 0.3 when the retardation value is measured at the wavelength of 450 nm, 550 nm and 650 nm, wherein one of the optically anisotropic layers A and B is a layer made from liquid crystal molecules, and the other is a polymer film.
- 12. A quartet wave plate comprising an optically anisotropic layer A and an optically anisotropic layer B, said optically anisotropic layer A having a retardation value in the range of 210 to 300 nm when the retardation valve is measured at the wavelength of 550 nm, and said optically anisotropic layer 13 having a retardation value in the range of 115 to 150 nm when the retardation value is measured at the wavelength of 550 nm, said quarter wave plate having a ratio of a retardation value to a wavelength in the range of 0.2 to 0.3 when the retardation value is measured at the wavelength of 450 nm, 550 nm and 650 nm, wherein each of the optically anisotropic layers A and B is a layer made from liquid crystal molecules.
- 23. A circularly polarizing plate which comprises a linearly polarizing membrane and a quarter wave plate comprising an optically anisotropic layer A and an optically anisotropic layer B, said optically anisotropic layer A having a retardation value in the range of 210 to 300 nm when the retardation value is measured at the wavelength of 550 nm, and said optically anisotropic layer B having a retardation value in the range of 115 to 150 nm when the retardation value it measured at the wavelength of 550 nm, said quarter wave plate having a ratio of a retardation value to a wavelength in the range of 0.2 to 0.3 when the retardation value is measured at the wavelength of 450 nm, 550 nm, and 650 nm, wherein each of the optically anisotropic layers A and B is a layer made from liquid crystal molecules.
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32. A reflective liquid crystal display comprising a reflector, is liquid crystal cell and a linearly polarizing membrane in this order, wherein a quarter wave plate is further arranged between the liquid crystal cell and the linearly polarizing membrane, said quarter wave plate comprising an optically anisotropic layer A and an optically anisotropic layer B, said optically anisotropic layer A having a retardation value in the range of 210 to 300 nm when the retardation value is measured at the wavelength of 550 nm, and said optically anisotropic layer B having a retardation value in the range of 115 to 150 nm when the retardation value is measured at the wavelength of 550 nm, said quarter wave plate having a ratio of a retardation value to a wavelength with the range of 0.2 to 0.3 when the retardation value is measured at the wavelength of 450 nm, 550 nm and 650 nm, wherein one of the optically anisotropic layers A and B is a layer made from liquid crystal molecules, and the other is a polymer him.
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33. A reflective liquid crystal display comprising a reflector, a liquid crystal cell and a linearly polarizing membrane so this order, wherein a quarter wave plate is further arranged between the liquid crystal cell and the linearly polarizing membrane, said quarter wave plate comprising an optically anisotropic layer A and an optically anisotropic layer B, said optically anisotropic layer A having a retardation value in the range of 210 to 300 nm when the retardation value is measured at the wavelength of 550 nm, and said optically anisotropic layer B having a retardation value in the range of 115 to 150 nm when the retardation value is measured as the wavelength of 550 nm, said quarter wave plate having a ratio of a retardation value to a wavelength in the range of 0.2 to 0.3 when the retardation value is measured at the wavelength of 450 nm, 550 nm and 650 nm, wherein one of the optically anisotropic layers A and B is a layer made from liquid crystal molecules.
Specification