Folded optics methods and apparatus for improving efficiency of LED-based luminaires

摘要

A hybrid lens collimates light emitted by a light source via refraction and reflection. A folded optic element of the lens comprises an outer reflective surface, a lens output surface, and a hollow core comprising a sidewall having a curved profile, a core output boundary, and a core input opening through which the light emitted by the light source enters the hollow core. A reflector of the lens receives the light emitted by the light source, reflects a first portion of the light into the hollow core of the folded optic element, and directly transmits a second portion of the light into the hollow core without reflection by the reflector. In one example, the lens output surface has a diameter of 65 millimeters, the lens has a thickness (between the light source and the lens output surface) of about 13.5 millimeters and provides substantially collimated light with a beam divergence angle of 12 degrees or less.