US Patent 7736029 Lens array and illumination module

A lens array includes a first lens group with rows of first lenses having first optical surfaces, a second lens group with rows of second lenses having second optical surfaces, and a reference plane. Each first and second lenses extend along a first axis. The second lenses are disposed at two sides of the first lens group along a second axis perpendicular to the first axis. An optical axis of the second optical surface is perpendicular to the first and second axis. An optical axis of the first optical surface is perpendicular to the first axis and has an angle larger than 0 degree and smaller than 6 degrees with the optical axis of the second optical surface. The reference plane perpendicular to the second axis passes through the first lens group. A normal vector of each first optical surface on the optical axis points away from the reference plane.