Patent ID: 7775679

Claim:
A light source for use in a machine vision system for substantially uniformly illuminating a predetermined area, comprising: a base plate; a plurality of high intensity light emitting diodes mounted at spaced apart positions to said base plate, each of said diodes including a main body topped off by a primary lens having a convex end surface facing away from the base plate and an optical axis extending through said lens, each diode when energized emitting a light beam, consisting of a collection of light rays, along a light beam axis which deviates angularly from said optical axis of the primary lens; a secondary lens positioned over the primary lens of each of said diodes, each secondary lens including an interior surface spaced from, and having a concave curvature substantially coinciding with that of, the convex end surface of the primary lens over which it is positioned, and means for fixing the angular position of each secondary lens relative to the associated diode to compensate for said deviation so that the light beam transmitted by each secondary lens when its associated diode is energized is symmetric about the optical axis of said primary lens.