Patent ID: 8049710

Claim:
An autostereoscopic display apparatus comprising: a display panel alternately displaying a plurality of images of different view points; image separating means for separating the plurality of images such that the separated images can be alternately observed in different viewing zones; and a directional backlight unit switched between a plurality of different angular distributions of illumination to selectively provide light to the display panel, wherein the directional backlight unit is switched between the plurality of different angular distributions of illumination in synchronization with an image display period of the display panel, and wherein the directional backlight unit comprises: a backlight; a first polarization plate disposed in front of the backlight; a polarization switch which changes the polarization direction of incident light according to an electrical control; a birefringent element array having a plurality of alternating first and second birefringent elements; a lenticular lens sheet having a plurality of parallel lenticular lens elements; and a second polarization plate disposed in front of the lenticular lens sheet.