Patent ID: 8714781

Claim:
A film illumination system including: a. a transparent polymer sheet having opposing planar faces with a thickness not greater than 0.5 mm therebetween, the sheet defining a body with an array of elongated legs extending therefrom, wherein: (1) each leg has a bounding edge with opposing lengthwise edges extending therefrom, (2) the lengthwise edges are optically smooth such that at least substantial total internal reflection is provided to light traveling within the legs and encountering the edges, and (3) each leg is folded at a radius of curvature less than 50 times the sheet thickness such that the portions of the leg on the opposing sides of the fold have: i. faces oriented in at least substantially parallel planes, and ii. lengthwise axes extending at a nonzero angle with respect to each other, with the bounding edges being stacked in parallel face-to-face relation; and b. a light source: (1) emitting non-collimated light from an emission area greater than the thickness of the sheet, and (2) optically coupled to the stacked bounding edges of the legs, such that the light from the light source enters the bounding edges to travel to the body.