Multi-parabolic illuminator to combine perpendicular collimated illuminations with an LED source

Abstract

Collimated illumination with a light-emitting diode (LED) is widely used in the residential, commercial, and industrial inspection fields. A slim LED illuminator composed of multi-parabolic surfaces to combine perpendicular collimated illuminations is proposed here. The multi-parabolic illuminator can produce a collimated rectangular illumination where light angle distributions for perpendicular axes can independently be controlled by different parabolic surfaces. This independence of the control makes the design of the illuminator simple. A prototype of the multi-parabolic illuminator is fabricated with an LED chip size of 3×3 mm and an opening aperture size of 20×60 mm. A maximum width of the prototype is 20 mm. The prototype demonstrates a production of a highly collimated rectangular illumination with half-intensity angles of about 7 degrees and 34 degrees for respective perpendicular axes.