<title>Eclipse projection</title>

Abstract

We have used the eclipse method for a pair of liquid crystal (LC) projectors so they produce a stereoscopic image, with very little cross-talk, by taking advantage of the fact that liquid crystal projectors have long image lag. We operate an eclipse system whose rate is independent of the field rate of the projectors since the liquid crystal image is sustained more or less continuously. In this way we are turning a problem associated with these projectors into the method for projecting good stereoscopic images. We use a pair of LC shutters at the projector lenses opening and closing out of phase with each other, eclipsing the images at a high enough rate to preclude flicker. The selection device eyewear uses left and right LC shutters that run in synchrony with the projector shutters. A stereoscopic images is viewed the right image is seen by the right eye when the right shutters for both projector and eyewear are open. The left eye image is blocked by both eyewear and projector shutters, and so on, vice versa, field after field. The fields have been, in effect, created by the projector shutters and are unrelated to the actual video field rate. An important aspect of this approach is that the resultant stereo image has very low cross-talk because the process is dependent upon the dynamic range of the LC shutters and eliminates any contribution of cross-talk from pixel hysteresis.