Patent ID: 8493657

Claim:
A light source switching device adapted for a projection system, wherein the projection system is adapted to alternately provide a first light, a second light and a third light, the light source switching device comprising: a first light guiding device, having a first incident surface and a second incident surface, which is not parallel to the first incident surface; a second light guiding device, having a third incident surface, which is not parallel to one of the first incident surface and the second incident surface; a third light guiding device, having an outlet surface; a first phase switching device, disposed between the first light guiding device and the second light guiding device, the first phase switching device being adapted to be in one of a first status and a second status; and a second phase switching device, disposed between the second light guiding device and the third light guiding device, the second phase switching device being adapted to be in one of a third status and a fourth status; wherein when the first light travels into the first light guiding device from the first incident surface, the first phase switching device is capable of being in the first status thereof such that the first light is adapted to travel into the third light guiding device after traveling through the second light guiding device, and meanwhile the second phase switching device is capable of being in the third status thereof such that the first light is adapted to emit out from the outlet surface after traveling through the third light guiding device; when the second light travels into the first light guiding device from the second incident surface, the first phase switching device is capable of being in the second status thereof such that the second light is adapted to travel into the third light guiding device after traveling through the second guiding device, and meanwhile the second phase switching device is capable of being in the third status thereof such that the second light is adapted to emit out from the outlet surface after traveling through the third light guiding device; and when the third light travels into the second light guiding device from the third incident surface, the second phase switching device is capable of being in the fourth status thereof such that the third light is adapted to emit out from the outlet surface after traveling through the third light guiding device.