| abstract |
An optical film (defined as an optical film-A) produced by drawing resin containing needle-like birefringent fine particles, characterized in that the resin exhibits a positive birefringence in the drawing direction, the needle-like birefringent fine particles exhibit a negative birefringence in the drawing direction of the resin, and the optical film has the following optical values: nx(a)>nz(a)>ny(a), 105nm≤Ro(a)≤350nm, 0.2<Nz<0.7, where Ro(a), Nz are defined as follows: Expression (i) Ro(a)=(nx(a)-ny(a))×d, expression (ii) Nz=(nx(a)-nz(a))/(nx(a)-ny(a)), (where, drawing direction of resin is y, refractive index in the drawing direction ny(a), refractive index in a direction orthogonal to y in film plane nx(a), refractive index in film thickness direction nz(a), and thickness (nm) of film d). |