Led collimation optics with improved performance and reduced size

Abstract

An LED module that includes an LED (light-emitting diode) and a rotationally symmetrical, bowl-shaped collimator lens is provided. The collimator lens has an inner refractive wall, an outer reflective wall, a first surface having an entrance aperture with a recess in which the LED is situated and which collimator lens is also provided with a second surface from which light generated by the LED emerges, the normal to the surface extending substantially parallel to the axis of symmetry of the lens, and the LED module also includes one or more of the following structures: (1) a conic wall portion of the recess of the inner refractive wall at the entrance aperture that includes a curved portion, and an outer reflective wall so configured in accordance with the structure of the inner refractive wall to achieve substantial collimation of a source of light at the entrance aperture; and/or (2) a first surface of the lens that is recessed away from the LED source; and/or (3) two surfaces of said refractive wall between which the refractive function of said refractive wall is divided. The LED module offers an improvement in the performance of the Flat top Tulip Collimator disclosed and claimed in our co-pending application Ser. No. 09/415,833 in terms of reduced size, beam divergence, beam uniformity, and to some degree efficiency. Moreover, it allows a wider variety of choices in optimizing various performance characteristics, and this in turn allows more flexibility in the structure design.