AREA SENSOR, LIQUID CRYSTAL DISPLAY UNIT, AND POSITION DETECTION METHOD

摘要

A liquid crystal display unit (100) comprises a liquid crystal panel (20) in which an optical sensor for detecting the intensity of light incident upon a front side thereof is incorporated, a back light (10) which emits light onto the liquid crystal panel (20) from a rear side, and a polarization reflection plate (50) which is arranged between the liquid crystal panel (20) and a front side polarization plate (40a) and which permits a component of light emitted from the back light (10) and transmitted through the liquid crystal panel (20), that oscillates in a direction parallel with the transmission axis of the front side polarization plate (40a) and reflects a component of the light which oscillates in a direction perpendicular to the transmission axis.