Photopic Optimization of Digital Micromirror Devices (DMDs)


  • Matthew Engel Student


Digital Micromirror Devices (DMDs) are a type of Micro-Opto-Electro-Mechanical System (MOEMS) consisting of an array of hundreds of thousands to millions of mirrors, which are individually programmed to tilt in one of two ways, ON (+12o) and OFF (-12o). These devices are at the heart of Digital Light Projection (DLP) systems, providing for a means of pixilation in laser projector systems. These DMDs are one of the main efficiency bottlenecks in DLP systems, averaging 69% efficiency in the visible spectrum. By improving the efficiency of these devices it is possible to reduce costs during production of DLP systems and reduce power consumption. Two factors that can be altered to increase the efficiency are the transmission through an optical window and the reflectance off an array of aluminium mirrors. The most practical way to improve the efficiency is found to be by applying a High Reflectivity (HR) coating to the surface of these DMDs. The coating must meet the power and thermal constraints currently present in DMDs and must be easily applied. Two coatings were found to meet these criterion: Duraflect and SiO2 (Enhanced Aluminium). These coatings have been projected to increase efficiency by an average of 11% and 10.7% respectively. In order to obtain a clearer picture on the optimal coating to use, additional testing must be performed on the modified DMDs.