Time-multiplexed dual-focal plane head-mounted display with a liquid lens

Focus cues play a significant role in three-dimensional (3-D) depth perception. Conventional stereoscopic displays, however, lack the ability to correctly render these cues, because they present a pair of stereoscopic images on a fixed image plane while forcing the eyes to converge at different distances to view objects at different depths. Using a fast liquid-lens device, we present the design and implementation of a time-multiplexed dual-focal plane display that is capable of rendering correct or near-correct focus cues as well as other depth cues, such as occlusion and shading for a 3-D scene. The focus range of the dual focal planes can vary from infinity to as close as 8 diopters. Two driving mechanisms are proposed to render near-correct focus cues and their effects on image sharpness, flicker, and brightness are compared.