Patent ID: 8111968

Claim:
A device for guiding illumination comprising: a body having a first surface with a plurality of ramp structures and falling structures, a second surface in which said first surface and said second surface are along opposite sides of said body, and an optical axis substantially parallel to said second surface; said ramp structures and said falling structures alternate with each other along said first surface, in which at least one of said ramp structures enables transmission of light from the ramp structure out of said body towards an adjacent one of said falling structures which receives the transmitted light back into the body, wherein light when received from one end of said body is totally or substantially internally reflected within said body unless transmitted from said at least one of said ramp structures out of and back into said body via an adjacent one of said falling structures until directed by reflection from one of said ramp structures to exit said body from said second surface; and each one of said ramp structures meets the next one of said falling structures along said first surface from said one end of said body at an acute angled apex, each of said ramp structures represents a rising surface at a first acute angle with respect to said optical axis, and each of said falling structures represents a falling surface tilted at the acute angled apex forming a second acute angle with respect to the normal of said optical axis toward the rising surface of one of said ramp structures which preceded the falling surface along said first surface from said one end of said body.