Light guiding plate, illumination device, and liquid crystal display device

摘要

An illumination device (10) having high contrast and high brightness, capable of reducing the quantity of leaking light, and capable of being made thin is provided. The illumination device includes a light source (15) and a light guiding plate (12) that introduces light of the light source from a side end face (12a) to the inside of the light guiding plate (12) and emits the light that propagates the inside of the light guiding plate from an emitting face (12b). Prismatic shapes (14) for reflecting the propagated light inside the light guiding plate (12) and emitting the reflected light to the emitting face are formed on the emitting face of the light guiding plate (12).