Research described in this paper encompasses the design and building of glasses-free (autostereoscopic) displays that utilize a direct-view liquid-crystal display whose backlight is provided by a projector and novel steering optics. This is controlled by the output of a multi-user head-position tracker. As the displays employ spatial multiplexing on a liquid-crystal-display screen, they are inherently 2-D/3-D switchable with 2-D being achieved by simply displaying the same image in the left and right channels. Two prototypes are described in this paper; one incorporating a holographic projector and the other a conventional LCOS projector. The LCOS projector version addresses the limitations of brightness, cross-talk, banding in the images, and laser stability that occur in the holographic projector version. The future development is considered and a comparison between the prototypes and with other 3-D displays is given.
