Patent ID: 8154672
Filing Date: 2012-04-10
Classification: G02B,G02F,H04N

Abstract:
1. A reflective liquid crystal display apparatus comprising: a polarization beam splitter having a polarization split film; a reflective liquid crystal display device; a quarter wave plate disposed between the polarization beam splitter and the reflective liquid crystal display device; and an illumination optical system configured for guiding a light flux from a light source in a converged state to the polarization beam splitter, and also illuminating the reflective liquid crystal display device with light from the light source via the polarization beam splitter and the quarter wave plate, wherein an optical axis of the illumination optical system is inclined with respect to the polarization split film; wherein, with the positive phase difference provided to convert linear polarized light into right-handed circling polarized light or elliptic polarized light and the negative phase difference provided to convert linear polarized light into left-handed circling polarized light or elliptic polarized light, the phase difference which the reflective liquid crystal display device in a black display state of the reflective liquid crystal display apparatus provides to the diffracted light occurring at the reflective liquid crystal display device is positive or zero, wherein, with the polarization direction of S-polarized light defined by the optical axis of the illumination optical system and the polarization split film as the S-polarization direction, the polarization split film which receives the light flux in a converged state has a first region which emits light having a polarization direction inclined clockwise with respect to the S-polarization direction as viewed from the side of the reflective liquid crystal display device, and a second region which emits light having a polarization direction inclined counter-clockwise with respect to the S-polarization direction as viewed from the side of the reflective liquid crystal display device, wherein a cross-point is an intersection point of the optical axis of the illumination optical system and the reflective liquid crystal display, wherein the phase difference, which the reflective liquid crystal display device provides to the first diffracted light emitted from the cross-point and cast into the first region, is greater than the phase difference which the reflective liquid crystal display device provides to the second diffracted light emitted from the cross-point and cast into the second region, and wherein the quarter wave plate can be positioned such that the direction of the fast axis of the quarter wave plate and the S-polarization direction are generally parallel.