Research on DMD infrared scene projector with a high contrast ratio infrared prism design

In this paper a single-DMD infrared scene projector with a high contrast ratio prism design of the illumination optical system is presented. By using the innovative infrared three-element TIR prism group, the off-state and flat-state light that reflected by the DMD could be all steered away from the projection lens. The contrast ratio and optical efficiency has been improved with this three-element TIR prism as the light-separator. This DMD infrared scene projector also features low-profile and compact structure. The illumination and projection optical systems are proved to be of great efficient light utilization. In this letter we analyze the impacts of optical efficiency on temperature simulation. This architecture with three-element TIR prism added could be used in IRSP based single-DMD to improve contrast and optical efficiency.