Patent ID: 7674019

Claim:
An illumination system comprising a light source, an illumination lens, and at least one rectangular target zones, the light source emitting light into a solid angle exceeding pi steradians with a known intensity distribution, the illumination lens comprising a first surface that receives at least 90% of the light of the known intensity distribution, the first surface shaped to transform the known intensity distribution into an intermediate intensity distribution within the transparent material of the lens, the lens further comprising a second surface that receives the intermediate intensity distribution, the second surface shaped to transform the intermediate intensity distribution into a final intensity distribution that produces a prescribed illumination distribution upon the at least one rectangular target zone, at least one of the shapes of the first and second surfaces being non-rotationally symmetric and being mathematically generated by: identifying a rectangular grid on the target; and; in correspondence with the rectangular grid on the target, establishing a sphere-covering pseudo-rectangular grid on the solid angle of the source emission, wherein: the pseudo-rectangular grid has the same proportions and the same number of cells as the rectangular grid on the target; the cells of the rectangular grid on the target and the cells of the pseudo-rectangular grid have the same relative assignment of light flux; and each cell has a representative central ray.