Patent ID: RE42617

Claim:
An image projection system comprising: a light source for generating a light beam; a reflective housing comprising an opening, the opening having a diameter smaller than a maximum diameter of the reflective housing, the reflective housing forming an accommodating space, the light source installed inside the accommodating space so that the light beam generated by the light source substantially propagates along an optical path through the opening away from the accommodating space, wherein the reflective housing is substantially parabolic shaped, and the optical path is a substantially parallel route by which the light beam propagates after being reflected by the parabolic reflective housing; and an invisible-light reflector installed at a reflecting position intersecting with the optical path outside the opening of the reflective housing, a normal of the invisible-light reflector and the optical path intersecting to form a predetermined angle so that invisible light of the light beam emitted from the opening will be reflected back into the accommodating space; wherein the predetermined angle formed by the normal of the invisible-light reflector and the optical path is an acute angle not equal to zero degrees, so that infrared rays of the light beam reflected back into the accommodating space by the invisible-light reflector will not focus on the reflective housing.