Yen-Pin TSAI and Chinghua HUNG^*

Department of Mechanical Engineering, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 300, Taiwan, R.O.C.

(Received July 21, 2010; Accepted January 19, 2011)

In this article, we report an optical design for a light emitting diode that can achieve high illumination quality using two hyperbolic reflectors. The relative movements of the reflectors and the light source produce a zoom function that can change the illumination beam from convergence to divergence. This study uses optical software ZEMAX for system simulation, and optimization was performed to select reflector parameters with the objectives of both improving floodlight uniformity and spotlight efficiency. Finally, experiments were conducted to verify the validity of the design, and the results corresponded well to the zoom illumination simulations.

Key words: hyperbolic, reflector, LED, illumination, optimization

^*E-mail address: chhung@mail.nctu.edu.tw