Design of LED optics with two aspherical surfaces and the highest efficiency

Abstract

The method for computation of LED optical elements with two aspherical surfaces and the highest possible efficiency is presented. The series of optical elements producing uniformly illuminated circle regions were computed and simulated with point light source. The simulation data shows that such optical elements have good performance for all angular sizes of the illuminated region (from 0° to 160°) including cases of full collimation and illumination of wide regions. The proposed design method works well with extended light sources too. The optical element with height of 7 mm generating uniformly illuminated region with angular size of 60° was simulated with extended light source 1x1 mm. The light efficiency decreased by 1-2 % only and the irradiance distribution remained the same. Taking into account the small dimensions of the proposed optical elements they can compete with TIR-optics in cases of generation narrow-angle light distributions.