To provide an optical polarizer that can be adapted to light from a point light source and reduce luminance unevenness, and to provide a surface light source device and a transmission image display device.
A light diffusion plate 21 includes a plurality of first convex sections 30 extending in a first direction and formed in parallel on a first main surface 21a, and a plurality of optical element sections 40 extending in a second direction and formed on a second main surface. Each of the first convex sections 30 has a curved surface. Each of the optical element section 40 is formed to have a region where the intensity distribution of exit light in a plane orthogonal to the second direction changes in a linear function manner in the range of 10 to 90% of the maximum intensity of the exit light. When a measurement light source is disposed at a distance of 100 mm from the first main surface 21a for measuring the exit light, the intensity distribution of the exit light is obtained based on the light source position in the second direction, with respect to the distance therefrom. The region of the intensity distribution has point symmetry with respect to the position corresponding to 50% of the maximum intensity.
OTA HIROSHI
Yoshinori Shimizu
Takashi Mikami