Dependence of viewing characteristics on polarization of scattered light from PDLC illuminated by planar light guide

The viewing characteristics of normally scattering polymer dispersed liquid crystal (PDLC) illuminated by guided light were studied. Luminance inversi on occurred at viewing angles of more than 40 degrees for the polarization component parallel to the plane of incidence while contrast ratio was more than I at all angles for the polarization component perpendicular to that p lane. The luminance inversion was caused by the refractive index mismatch f or the polarization component parallel to the plane of incidence even when an electric field was applied. By controlling the polarization of scattered light, we could suppress the luminance inversion.