Reflector Design Using LightTools

By Optical Research Associates

LightTools can be used to design and analyze the performance of a wide variety of illumination systems. Recently, LightTools was put to the test to redesign a segmented-reflector stop lamp at Yorka North America. Using LightTools to precisely analyze the luminous intensity and illuminance distributions in the original design, we were able to correct the design problems, meet SAE standards, and build a prototype that agreed very well with the simulations. This paper describes how the redesign was accomplished.

The first step was to simulate the original system to reproduce the problems seen in the initial prototype. The original geometry of the segmented-reflector stop lamp was imported into LightTools using the IGES import capability. Then, a 3157 bulb was added to each section. In addition, reflective surface properties and two receivers were added to complete the simulation setup. One receiver was a farfield receiver that measured the luminous intensity output, and the other was a surface receiver that measured the illuminance distribution hitting the outer tail lens.