Image projection and detection apparatus

An image projection and detection apparatus, comprising:

• an illumination system, capable of providing an illumination beam;
• a digital micro-mirror device, disposed in an optical path of the illumination beam and comprising a plurality of micro-mirror structures, wherein each of the micro-mirror structures is capable of being switched between an on-state and an off-state, at least a part of the micro-mirror structures reflect the illumination beam into an image beam when in the on-state, and the image beam is transmitted to an object side;
• an optical detector, wherein at least a part of the micro-mirror structures reflect an object beam from the object side to the optical detector when in the off-state;
• and
• a total internal reflection unit, comprising:
• a first prism, having a light-incident surface and a first total reflection surface, wherein the illumination beam from the illumination system enters the first prism through the light-incident surface, and is totally reflected to the digital micro-mirror device by the first total reflection surface, the image beam formed by the reflection of at least a part of the micro-mirror structures in the on-state passes through the first total reflection surface and is transmitted to the object side, and the object beam from the object side passes through the first total reflection surface and is transmitted to the digital micro-mirror device;
• and
• a second prism, having a first optical surface and a second total reflection surface, wherein a first gap is maintained between the first optical surface and the first total reflection surface, the object beam reflected by at least a part of the micro-mirror structures in the off-state sequentially passes through the first total reflection surface, the first gap and the first optical surface, and is then totally reflected to the optical detector by the second total reflection surface.