Advancements in 3-D stereoscopic display technologies : Micropolarizers, improved LC shutters, spectral multiplexing, and CLC inks : 3-D imaging

An overview of four new technologies for stereoscopic imaging developed by VRex, Inc., of Elmsford, New York, is presented. First, the invention of μPol micropolarizers has made possible the spatial multiplexing of left and right images in a single display, such as an LCD flat panel or photographic medium for stereoscopic viewing with cross-polarized optically passive eyewear. The μPol applications include practical, commercially available stereoscopic panels and projectors. Second, improvements in fabrication of twisted nematic (TN) liquid crystals and efficient synchronization circuits have increased the switching speed and decreased the power requirements of LC shutters that temporally demultiplex left and right images presented field-sequentially by CRT devices. Practical low-power wireless stereoscopic eyewear has resulted. Third, a new technique called spectral multiplexing generates flicker-free field-sequential stereoscopic displays at the standard NTSC video rate of 30 Hz per frame by separating the color components ofimages into both fields, eliminating the dark field interval that causes flicker. Fourth, new manufacturing techniques have improved cholesteric liquid crystal (CLC) inks that polarize in orthogonal states by wavelength to encode left and right images for stereoscopic printers, artwork, and other 3-D hardcopy.