Reduction of speckles and distortion in projection system by using a rotating diffuser

Abstract

A head up display (HUD) with laser backlight unit has two principle problems; one is laser speckles and the other is distortion. In this study, we propose that a rotating diffuser set at the intermediate image plane of the HUD projection system can simultaneously solve these problems. The conditions of speckle reduction and de-distortion are also estimated in this paper.