With a wealth of design freedom, freeform optical surface is gaining more and more uses in the field of LED lighting. In this paper, aiming at the commercial LED lighting application, a design method combining freeform surface and aspherical surface for reducing the source model error is presented, which can decrease error caused by the point source model and increase the accuracy of the light distribution effectively. Based on this method, a LED spotlight lens for realizing octagon spot is designed. By using the injection molding machine, the plastic lens is manufactured, and it is tested by using a goniophotometer. The experimental result shows good consistence with the design. The method may be useful for improving the design precision in the LED lighting.
© 2013 Optical Society of AmericaPDF Article