Patent ID: 8237901
Filing Date: 2012-08-07
Classification: G02F

Abstract:
1. A liquid crystal display device comprising: an OCB mode liquid crystal display panel comprising a first substrate including a first alignment film, a second substrate including a second alignment film, and a liquid crystal layer which is held between the first alignment film and the second alignment film, a rubbing direction of the first alignment film and the second alignment film agrees with a reference azimuth direction; and a first optical compensation element which is disposed outside the first substrate and a second optical compensation element which is disposed outside the first substrate, the first optical compensation element and the second optical compensation element optically compensating a retardation of the liquid crystal layer in a predetermined display state in which a voltage is applied to the liquid crystal layer; wherein the first optical compensation element includes: a first polarizer plate having a first absorption axis which intersects at 45° with respect to the reference azimuth direction, a first retardation plate which is disposed between the first polarizer plate and the liquid crystal display panel, includes a first slow axis parallel with the reference azimuth direction, and imparts a phase difference of a ¼ wavelength; a second retardation plate which is disposed between the first polarizer plate and the first retardation plate, includes a second slow axis parallel with the first absorption axis, and has a biaxial refractive index anisotropy; a third retardation plate corresponding to an A-plate which is disposed between the first retardation plate and the liquid crystal display panel and includes a third slow axis perpendicular to the reference azimuth direction, and a fourth retardation plate corresponding to a C-plate which is disposed between the first retardation plate and the third retardation plate; the second optical compensation element includes: a second polarizer plate having a second absorption axis which intersects at 135° with respect to the reference azimuth direction; a fifth retardation plate which is disposed between the second polarizer plate and the liquid crystal display panel, includes a fifth slow axis perpendicular to the reference azimuth direction, and imparts a phase difference of a ¼ wavelength; a sixth retardation plate which is disposed between the second polarizer plate and the fifth retardation plate, includes a sixth slow axis perpendicular to the second absorption axis, and has a biaxial refractive index anisotropy; a seventh retardation plate corresponding to an A-plate which is disposed between the fifth retardation plate and the liquid crystal display panel and includes a seventh slow axis perpendicular to the reference azimuth direction; and an eighth retardation plate corresponding to a C-plate which is disposed between the fifth retardation plate and the seventh retardation plate, and the second retardation plate has the refractive index anisotropy which is set in such a manner as to compensate (a) a difference of a polarization state due to an influence of optical rotary power that differs between azimuth directions of light passing through the liquid crystal layer and to compensate (b) a shift of the polarization state of light, which passes through the first retardation plate, from an azimuth direction of the first absorption axis of the first polarizer plate.