Patent ID: 8152339
Filing Date: 2012-04-10
Classification: F21S,G02B,H01L,Y02E,Y10T

Abstract:
1. An illumination device based on multiple total internal reflections, comprising: a light-projecting slab having a plurality of injection faces and an output surface, the light-projecting slab further including a plurality of optical elements located optically between the plurality of injection faces and the output surface, each optical element being separated from adjacent elements by a material having an index of refraction lower than that of a material of the light-projecting slab, wherein each optical element includes a curved reflection surface, in cross-section the curve of the reflection surface being at least substantially parabolic and having an axis of symmetry and a focal point lying at least substantially along the axis of symmetry; an injection molded wedge-shaped optical waveguide slab separate from and optically coupled to the light-projecting slab, the optical waveguide slab having a first surface that is a reflector operating by total internal reflection in conjunction with a plurality of reflectors opposed to the first surface, the optical waveguide slab further including a plurality of exit faces adjacent the injection faces of the light-projecting slab, the plurality of injection faces and the plurality of exit faces forming a plurality of optical input apertures located between the optical waveguide slab and the light-projecting slab, the optical waveguide slab further including an input surface to receive light from a light source, the waveguide slab guiding the light from the input surface towards the optical input apertures through multiple total internal reflections, the optical elements of the light-projecting slab directing the light from each input aperture to the output surface wherefrom the light exits the illumination device as a plurality of beams, each beam having been reflected off the reflection surface of one of the optical elements via total internal reflection, in cross-section the curves of the reflection surfaces of the optical elements each having a shape such that light passing generally through that curve's focal point and reflecting off the reflection surface which forms that curve has an output direction generally parallel to the axis of symmetry of that curve of that reflection surface; and the light source being optically coupled to the input surface of the optical waveguide slab.