Patent ID: 7652818

Claim:
An optical sight comprising: an optical train having an optical path therethrough, an entrance, and an exit; a reticle visible through the exit of the optical path; and an unpowered reticle illumination source having: a first light source that illuminates the reticle responsive to a level of ambient light, said first light source including: a scintillation material positioned so that ambient light entering an ambient-light receiver is incident upon the scintillation material, whereupon the scintillation material responsively emits secondary light and a light-gathering prism that receives the secondary light and has a diffusing surface disposed to illuminate the reticle using the secondary light, said prism having a first end into which said secondary light enters and multiple sides with reflective surfaces off which said secondary light reflects via total internal reflection to a exits to illuminate said reticle and a second light source that illuminates the reticle with an unpowered light source.