Patent ID: 7151582

Claim:
A liquid crystal display device comprising: a liquid crystal cell comprising a pair of substrates and a liquid crystal layer arranged between the pair of substrates, the liquid crystal of the liquid crystal cell being of a vertical alignment type; first and second polarizers arranged on either side of the liquid crystal cell; a first retardation plate arranged between the liquid crystal cell and the first polarizer; a second retardation plate arranged between the liquid crystal cell and the second polarizer; each of the first and second retardation plates having an optical axis in a plane parallel to the surfaces of the substrates and a retardation of substantially λ/4, the optical axis of the first retardation plate being perpendicular to the optical axis of the second retardation plate, the negative retardation ((nx+ny) /2−nz) of each of the retardation plates being approximately zero; a first optical plate arranged on or near the liquid crystal cell and having refractive indices in the relationship of nx=ny>nz, the first optical plate having a retardation the value of which is identical to that of the liquid crystal layer and the sign of which is reverse to that of the liquid crystal layer; a second optical plate having refractive indices in the relationship of nx=ny<nz, said second optical plate or a part thereof being arranged on or near the first polarizer; and a third optical plate arranged on or near the second polarizer and having refractive indices in the relationship of nx>ny=nz.