Patent ID: 8373692
Filing Date: 2013-02-12
Classification: G09G,H04N

Abstract:
1. An optical modulator comprising: a liquid crystal display device to convert a first linearly polarized-state bundle of rays, with optical modulation based on an input video signal, into a second linearly polarized-state bundle of rays that is orthogonal to the first linearly polarized-state bundle of rays in polarization, the first linearly polarized-state bundle of rays being involved in incident bundle of rays obtained by polarization conversion of a bundle of rays emitted from a light source and being incident on the optical modulator; a reflective polarizer to allow the first linearly polarized-state bundle of rays to pass therethrough before the first linearly polarized-state bundle of rays is optically modulated into the second linearly polarized-state bundle of rays, to reflect a third linearly polarized-state bundle of rays in a first direction, the third linearly polarized-state bundle of rays being in parallel with the second linearly polarized-state bundle of rays in polarization and being originally involved in the incident bundle of rays, and to reflect the second linearly polarized-state bundle of rays in a second direction different from the first direction; a transparent polarizer to allow the second linearly polarized-state bundle of rays reflected by the reflective polarizer in the second direction to pass therethrough and to reflect a fourth linearly polarized-state bundle of rays in the first direction, the fourth linearly polarized-state bundle of rays being in parallel with the first linearly polarized-state bundle of rays in polarization and being involved in the second linearly polarized-state bundle of rays reflected in the second direction; and an optical sensor to detect the fourth linearly polarized-state bundle of rays reflected by the transparent polarizer, wherein the liquid crystal display device is provided in a specific location so as to optically modulate the first linearly polarized-state bundle of rays that is incident thereon after passing through the reflective polarizer and to reflect the second linearly polarized-state bundle of rays obtained by the optical modulation towards the reflective polarizer so that the second linearly polarized-state bundle of rays is reflected by the reflective polarizer in the second direction, the reflective polarizer is provided in a specific location so as to allow the first linearly polarized-state bundle of rays to pass therethrough before optically modulated and to reflect the second linearly polarized-state bundle of rays obtained by the optical modulation towards the transparent polarizer, and the optical sensor is located on an optical path of the fourth linearly polarized-state bundle of rays reflected by the transparent polarizer in the first direction but not on an optical path of the third linearly polarized-state bundle of rays reflected by the reflective polarizer in the first direction.