To provide a light control board unit capable of fully and uniformly dispersing light from a point light source, a planar light source device, and a transmission type image display device.
The light control board unit has a first, second, and third light control boards arranged in a board-thickness direction, and each light control board has a plurality of projected sections extending in one direction on an upper surface; and the parallel projected sections and an extending direction of the projected sections approximately cross each other at right angles, the cross-sectional shape of the projected section is a triangle, and an outline shape v(u) satisfies the relationship: 0.95v0(u)≤v(u)≤1.05v0(u) at a uv coordinate system: when an axis line passing both ends on an orthogonal cross section in the extending direction of each projected section is a u axis. Here, the v0(u) satisfies formula (1).
KAWAGUCHI YUJIRO
KAWAKAMI TAKESHI
Yoshinori Shimizu
Takashi Mikami