Patent ID: 6970218

Claim:
A semi-transmissive type liquid crystal display device comprising: a semi-transmissive type liquid crystal display cell having a lower substrate, an upper substrate which constitutes an observation side, a liquid crystal layer sandwiched between the lower substrate and the upper substrate, a lower orientation film which is formed over a surface of the lower substrate which is brought into contact with the liquid crystal layer, and an upper orientation film formed over a surface of the upper substrate which is brought into contact with the liquid crystal layer; an upper polarizer arranged at a side of the upper substrate opposite to the liquid crystal layer; an upper Î»/2 phase difference plate arranged between the upper polarizer and the upper substrate; an upper Î»/4 phase difference plate arranged between the upper Î»/2 phase difference plate and the upper substrate; a lower polarizer arranged at a side of the lower substrate opposite to the liquid crystal layer; a lower Î»/2 phase difference plate arranged between the lower polarizer and the lower substrate; a lower Î»/4 phase difference plate arranged between the lower Î»/2 phase difference plate and the lower substrate; and an optical film having negative uniaxial double refractive index ellipsoids arranged between the lower Î»/4 phase difference plate and the lower substrate, wherein a twist angle of the liquid crystal layer is larger than 0Â° and equal to or smaller than 90Â°, the orientation axis direction of the optical film having negative uniaxial double refractive index ellipsoids is arranged within a range of âˆ’5Â° to +5Â° with respect to the direction which is rotated by 90Â° in the clockwise direction from a resultant vector of the orientation axis direction of the upper orientation film and the orientation axis direction of the lower orientation film of the liquid crystal display cell, and a phase lagging axis of the lower Î»/4 phase difference plate is arranged within a range of âˆ’10Â° to +10Â° with respect to the orientation axis direction of the optical film having negative uniaxial double refractive index ellipsoids, and a phase lagging axis of the upper 4/Î» phase difference plate is arranged within a range of âˆ’5Â° to +5Â° with respect to the direction which is rotated 90Â° in the clockwise direction from a resultant vector of the orientation axis direction of the upper orientation film and the orientation axis direction of the lower orientation film of the liquid crystal display cell.