Achromatic suppression of ghost images in head-up displays

We examine the chromatic properties of ghost images appearing in expanded viewing angle polarization-type head-up display systems. We propose an achromatic polarization correction method to suppress ghost images in the whole visible spectral range. The method is based on the use of two half-wave plates of orthogonal optical axis–one being laminated on the combiner, the other attached to the head-up display (HUD) projector. We show that in this configuration the dispersion of the two waveplates cancel each other. Based on the results, a ghost image free colour HUD is demonstrated with 13 ° × 40 ° FOV. We present our modeling and experimental results and our demonstration HUD system.