Single and multi-user head tracked glasses-free 3D displays

Abstract

This paper describes two head tracked displays; both provide glasses-free 3D (autostereoscopic) to viewers by producing pairs of exit pupils where the left and right stereo images are directed to the appropriate viewers' eyes under the control of a head tracker. The first display is single viewer where exit pupils are formed by a pair of picoprojectors whose position moves in accordance with the viewer's head position. Light is reflected back to the viewer's eyes using a retroreflecting screen. The second display is multi-user and is laser-based. A Gabor superlens screen is scanned with a vertical illumination column that acts as the backlight for a direct-view liquid crystal display (LCD). The emergent beam directions are controlled by a spatial light modulator (SLM) such that they land on the viewers' left and right eyes alternately. For each display the principle of operation, the display hardware and the results are presented here.