LIGHT EMITTING DEVICE, SURFACE LIGHT SOURCE, LIQUID CRYSTAL DISPLAY DEVICE, AND LENS

摘要

A light emitting device includes plural light emitting diodes and plural lenses each of which expands the light from the light emitting diode. The lens includes an incident surface through which the light from the light emitting diode is entered at an optical axis and around the optical axis, and an output surface from which the incident light is output while radially expanded. The incident surface includes a continuous concave surface, the output surface includes a continuous convex surface, and the lens has different refractive powers in a first direction orthogonal to the optical axis and in a second direction orthogonal to the optical axis and the first direction.