Design of a freeform reflector for LED sources based on a feedback method

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.

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References

Chu

S-C

Yang

H-L

Liao

Y-H

H-Y

Wang

. One-time ray-tracing optimization method and its application to the design of an illuminator for a tube photo-bioreactor. Optics Express 2014; 22: 5357–5374.

Chen

Han

Luo

. A fast feedback method to design easy-molding freeform optical system with uniform illuminance and high light control efficiency. Optics Express 2013; 21: 1258–1269.

Chen

J-J

Wang

T-Y

Huang

K-L

Liu

T-S

Tsa

M-D

Lin

C-T

. Freeform lens design for LED collimating illumination. Optics Express 2012; 20: 10984–10995.

Qian

. Optimal design of optical system for LED road lighting with high illuminance and luminance uniformity. Applied Optics 2013; 52: 5888–5893.

Taguchi

. Recent progress and future prospect of high-performance near-UV based white LEDs: From ECO lighting to medical application. Proceedings of the SPIE 2009; 7422: 74220B–74220B.

Winston R, Minano JC, Benitez P, editors with contributions by Shatz N and Bortz JC. Nonimaging Optics, London: Elsevier Academic Press, 2005.

Wang

Zhang

. Study on optical design methods for LED extended sources. Proceedings of the SPIE 2010; 7655: 765536–765536.

Ries

Winston

. Tailored edge-ray reflectors for illumination. Journal of the Optical Society of America A 1994; 11: 1260–1264.

Yoshida

Horiuchi

Ushiyama

Yamamoto

. A numerical analysis method for evaluating rod lenses using the Monte Carlo method. Optics Express 2010; 18: 27016–27027.

10.

Fang

Boas

. Monte Carlo simulation of photon migration in 3D turbid media accelerated by graphics processing units. Optics Express 2009; 17: 20178–20190.

11.

Rubinstein

Kroese

. Simulation and the Monte Carlo Method, 2nd. New York: John Wiley and Sons, 2007.

12.

Lee

. Analysis of light-emitting diodes by Monte Carlo photon simulation. Applied Optics 2001; 40: 1427–1437.

13.

Feng

Luo

Han

. Design of LED freeform optical system for road lighting with high luminance/illuminance ratio. Optics Express 2010; 18: 22020–22031.

14.

Luo

Feng

Han

. Design of compact and smooth free-form optical system with uniform illuminance for LED source. Optics Express 2010; 18: 9055–9063.

15.

Ding

Liu

Zheng

Z-R

. Freeform LED lens for uniform illumination. Optics Express 2008; 16: 12958–12966.

16.

Hong K. Uniform distribution of points on the surface of a sphere. Retrieved 10 November 2014, from http://www.bogotobogo.com/Algorithms/uniform_distribution_sphere.php.

17.

Wang

Chen

Liu

Luo

Liu

. Design of compact freeform lens for application specific light-emitting diode packaging. Optics Express 2010; 18: 41–425.

18.

Situ

Han

Luo

. Combined feedback method for designing a free-form optical system with complicated illumination patterns for an extended LED source. Optics Express 2011; 19: A1022–A1030.

19.

Pachamanov

Pachamanova

. Optimization of the light distribution of luminaires for tunnel and street lighting. Engineering Optimization 2008; 40: 47–65.

20.

Luo

Feng

Liu

. Effect of phosphor settling on the optical performance of phosphor-converted white light-emitting diodes. Journal of Luminescence 2012; 132: 1252–1256.

21.

Cassarly

David

Jenkins

Riser

. Automated design of a uniform distribution using faceted reflectors. Optical Engineering 2000; 39: 1830–1839.

22.

Fournier

Cassarly

Rolland

. Fast freeform reflector generation using source-target maps. Optics Express 2010; 18: 5295–5304.

23.

Zhang

Liu

Gao

. Free-form reflector optimization for general lighting. Optical Engineering 2010; 49: 063003–063003.