Multi-user 3D display

Abstract

A 3D display that incorporates an RGB laser projector as the backlight for an LCD and a head position tracker is described. The display provides 3D to several viewers who do not need to wear special glasses and are able to move freely over a large region. It operates on the principle of forming regions in the viewing field, referred to as exit pupils, where either a left image or a right image is seen on the screen. These exit pupils follow the positions of the viewers' eyes by using the output of the head tracker to control the backlight optics. The stereo image pair is displayed on a direct-view LCD and a steering optics array behind this forms the pupils. Frame sequential operation is being investigated as this enables higher resolution and simplified optics. An RBG laser source illuminates a binary phase hologram on an LCOS device that directs light to the appropriate positions on the array. The information on this device is derived from a high-precision single-user 3D video head tracker that employs an appearance-based method for initial head detection and a modified adaptive block-matching technique for head and eye location measurements in the tracking phase