Light control plate, surface light source device, and transmission type image display apparatus

摘要

A light control plate, a surface light source device, and a transmission type image display apparatus which can emit light widened within a predetermined angle range are provided. In a light control plate 40, a plurality of light components from respective light sources incident on a main face 40a are emitted from an exit surface 40b. A corresponding area 41 for a space between two light sources adjacent to each other in the main face of the light control plate 40 has first to third regions 41A to 41C. The first and third regions have a plurality of first light path control parts 42 for widening first incident light F1 i ; (F2 i ) within a predetermined angle range and emitting thus widened light from the exit surface by utilizing refraction of the first incident light on a plurality of planar parts 41 k,m . The second region has a second light path control part 43 for emitting second incident light F1 i , F2 i within the predetermined angle range from the exit surface by utilizing total reflection within a prism part 46 m . The first incident light is light from the light source closer to the first light path control part in the two light sources, while the second incident light is light from the two light sources.