Touch projection system

摘要

A touch projection system includes a screen, an image-capturing device, a micromirror device, and a TIR prism disposed in front of the micromirror device. The TIR prism includes an optical path compensation structure or a hollowed channel, so that an image light from the screen, traveling through the TIR prism to be reflected by the micromirror device, can travel through the optical path compensation structure or the hollowed channel to avoid a probable optical path difference on the image light due to traveling through the TIR prism. Thereby, the invention can solve that a distortion may be induced in a touch image formed by the image-capturing device receiving the image light reflected by the micromirror device.

主权项

1. A touch projection system, comprising:
a screen; a light source device for emitting projection light; an image-capturing device for receiving image light from the screen; a micromirror device for reflecting the projection light and the image light; and a total internal reflection prism, comprising:
a main body having a first side surface, a second side surface, a third side surface, and a fourth side surface, the second side surface being opposite to the first side surface, the third side surface and the fourth side surface being adjacent to the second side surface, the second side surface facing the micromirror device, the projection light from the light source device entering the main body through the third side surface, exiting out the main body through the second side surface, being reflected by the micromirror device to enter the main body through the second side surface, and exiting out the main body through the first side surface to be projected onto the screen; andan optical path compensation structure fixedly disposed on the fourth side surface, the image light from the screen entering the main body through the first side surface, exiting out the main body through the second side surface, being reflected by the micromirror device to enter the main body through the second side surface, and exiting out the main body through the optical path compensation structure to be received by the image-capturing device, wherein optical distances for the image light to travel from entering the main body through different portions of the second side surface to exiting out the main body through the optical path compensation structure are substantially equivalent.