Portable 3D laser projector using mixed polarization technique

Abstract

This paper introduces a new twist on stereoscopic displays-one that has similarities to existing methods in that it utilizes both polarization and color to present different stereo 3D perspectives to each eye, but by combining the use of polarization and color, it avoids weaknesses associated with previous methods. This new method is named Mixed Polarization 3D. Color imbalance artifacts associated with anaglyph methods of 3D are avoided by alternating the colors presented to each eye. Flicker, associated with polarization-sequential 3D, or the need to increase the frame rate to at least 120 Hz to avoid this perceived flicker, is avoided in mixed polarization 3D by presenting both eyes with 3D information in every single frame. It is particularly aimed at use in scanned laser projectors where all three primary colors (R, G, B) are already polarized and simultaneously displayed. Like other polarization-based approaches, it requires the use of a polarization-preserving screen and inexpensive passive polarization glasses. The 3D display needs just a single handheld mobile projector coupled with an active polarization rotator, thus the image registration problems with two projectors is avoided.