Polarization illumination device and projector having the same

摘要

A polarization illumination device and projector having the polarization illumination device are provided. An example of the polarization illumination device comprises an illuminator (1,2) and a polarizer (5). The polarizer comprises a polarization splitting surface (54) and a reflecting surface (53), which form an inverted V shape. The splitting surface (54) splits part of the light into a transmitted component (Lp) and a reflected component (Ls) and directs the former in a first direction and the latter is reflected back to the illuminator by the reflecting surface. the reflecting surface reflects a remaining part of the light and directs it toward the splitting surface. The splitting surface reflects one component back to the illuminator and transmits the other component toward a second direction different from the first direction. The light components reflected back to the illuminator change their plane of polarization by traversing the quarter waveplate twice before being incident on the polarizer again.