Design of a freeform reflector for LED sources based on a feedback method. (May 2016)

• Record Type: Journal Article
• Authors: Wu, H; Luo, C; Zhang, X; Ge, P; Zhang, X
• Is Part Of: Lighting research & technology. Volume 48:Number 3(2016)
• Page Start: 365
• Page End: 375
• Publication Date: 2016-05
• Subjects: Lighting -- Periodicals; 621.32
• DOI: 10.1177/1477153514564002
• Languages: English
• ISSNs: 1477-1535

Abstract

We propose a method for the design of a freeform reflector by means of feedback methods to create light-emitting diode (LED) sources with uniform illuminance. A reflector is first designed to obtain a uniform circular light distribution for a point source. Then the optical performance of the reflector is investigated for both the point sources and extended sources based on a Monte Carlo ray tracing method. Comparing the illumination differences, a new reflector is generated by adding feedback. Repeated iterations of feedback can improve the reflector performance. To validate the method, a reflector is designed for an extended LED source. The results demonstrate that the illuminance uniformity can reach 88% and system efficiency can reach 97.4% simultaneously, after six feedback cycles. These are certainly able to meet the needs of general lighting applications.