| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface light source device used for a liquid crystal display device which can be lightweight.SOLUTION: In the surface light source device wherein light is emitted to a liquid crystal display panel from a rear side of the liquid crystal display panel, the surface light source device includes a light source, and a polarized optical sheet for making light emitted from the light source incident and emit by polarizing the light. The polarized optical sheet has a prism section wherein a plurality of unit prisms are arranged on a side where the light source is arranged. The unit prism has an incident surface for making the light emitted from the light source incident into the unit prism, and a total reflection surface for totally reflecting the light incident from the incident surface. Each unit prism extends in an arc shape or a linear shape, and the plurality of unit prisms are arranged in a concentric shape or in a direction different from an extending direction. The light source emits light inclined in a radial direction of a concentric circle or in a direction where the unit prisms are lined up, to the prism part. |
