Patent ID: 7639427

Claim:
A light collecting device for a projection apparatus, comprising a first light collecting rod, the first light collecting rod comprising: a longitudinal direction; a body extending along the longitudinal direction; an incident end, defined at an end of the body, the incident end comprising a first incident surface and a first reflecting surface, the first incident surface being adjacent to the first reflecting surface to form an included angle therebetween; and an emergent end, defined at an end opposite to the incident end on the body; wherein the first light collecting rod is a prism having an cross sectional area increasing from the incident end to the emergent end along the longitudinal direction, a first light beam is adapted to pass through the first incident surface and travel in the body of the first light collecting rod toward the emergent end along the longitudinal direction, and a second light beam is adapted to enter the body of the first light collecting rod and be reflected by the first reflecting surface of the incident end to travel toward the emergent end along the longitudinal direction.