OPTICAL FILM, POLARIZING FILM USING THE OPTICAL FILM, AND METHOD OF IMPROVING VISIBILITY ANGLE OF POLARIZING FILM

摘要

An optical film, comprising a first phase contrast film (2) having a requirement of (ne - no > 0) where an average refractive index in the surface of at least one sheet of film is (no) and a refractive index in the thickness direction thereof is (ne) and a second phase contrast film (3) having a requirement of (nx > ny >/= nz) where a refractive index in the surface of at least one sheet of film in the direction providing the maximum refractive index is (nx), a refractive index in the direction perpendicular to that direction is (ny), and a refractive index in the thickness direction thereof is (nz), wherein both films are laminated with each other, whereby, when the absorbing axis directions of a polarizing plate are disposed perpendicular to each other, the leakage of light occurred when an observing direction is tilted from a front in a direction different from the absorbing axis directions can be reduced.