Patent ID: 8215777
Filing Date: 2012-07-10
Classification: G03B

Abstract:
1. A light guide module for use in a projection apparatus, the projection apparatus comprising an illumination mechanism and a DMD (Digital Micromirror Device), the illumination mechanism being adapted to provide a light beam, the light beam traveling along a first axis to the DMD via the light guide module, and then the light beam being reflected along a second axis, the light guide module comprising: a plurality of interfaces, being adapted to enable the light beam to undergo a plurality of total internal reflections on each of the interfaces in turn, wherein the total internal reflections have a traveling direction parallel to a reference plane, and the first axis and the second axis are parallel to each other; and a first prism, having a first surface, a second surface and a third surface for defining the interfaces, and the first prism having a refractive index substantially between 1.6 to 2.0, wherein the light beam travels to the first prism along the first axis, and then the light beam undergoes the total internal reflections on the first surface, the second surface and the third surface of the first prism in turn.