Patent ID: 7843515
Filing Date: 2010-11-30
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 having a first optical axis; 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 the illumination optical system has a second optical axis which is inclined with respect to the polarization split film, and 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, and wherein, with the polarization direction of S-polarized light defined by the second optical axis 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, and wherein the phase difference, which the reflective liquid crystal display device provides to the first diffracted light emitted from a point on the first optical axis 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 a point on the first optical axis and cast into the second region, and wherein the quarter wave plate is positioned such that the direction of the fast axis of the quarter wave plate and the S-polarization direction are generally parallel.