A study of the functions of a novel ripple TIR lens

Most LED luminaires encounter the problem of color non-uniformity in illumination fields. In order to address the issue, we propose a ripple TIR lens, which can apply to both phosphor-converted LEDs and multicolor LED arrays and achieves good color performance. The ripple TIR lens consists of a collimator and a ripple panel. Simulation results based on a precise phosphor-converted white LED model indicate that the normalized standard deviation (NSD) in terms of angular color uniform (ACU) of the LED model integrated with the ripple TIR lens decreases much from 0.792 to 0.232, compared with the NSD of the bare white LED. Moreover, a study of the ripple optics on multicolor LED arrays is proposed and analysis results demonstrate the ripple optics can enhance the color uniformity of illumination pattern. Various uniform colors with low NSDs can be achieved by adjusting the light output of each LED chip, which implies the ripple TIR lens has a good employment in fields of entertainment and architectural lighting.