Patent ID: 8820941

Claim:
A projection apparatus, comprising: a digital micro mirror device (DMD), suitable for being switched to a first operating state or a second operating state; a light source, emitting a light beam to the DMD; a lens, wherein when the DMD is switched to the first operating state, the DMD reflects the light beam to the lens; a photoelectric conversion device, wherein when the DMD is switched to the second operating state, the DMD reflects the light beam to the photoelectric conversion device, and the photoelectric conversion device generates a signal value according to a light intensity of the light beam; a decision device, electrically connected to the photoelectric conversion device, and comparing the signal value with a predetermined value, wherein when the signal value is smaller than the predetermined value, the decision device generates a driving signal value; and an adjustment module, electrically connected to the decision device and coupled to the light source, wherein the driving signal value is used for driving the adjustment module to sequentially adjust a position of the light source along a plurality of axes.