Design method for the high optical efficiency and uniformity illumination system of the projector

Abstract

How to balance the optical efficiency, illumination uniformity and the size of the illumination system is a challenging task in projector design. In this paper, we present a mathematical model describing the relationship between optical energy of the illumination system and the optical parameters and an optimization design method considering the light intensity distribution of the light source. By using the proposed method, two illumination systems are designed with different types of the digital micromirror device chips. In addition, we also propose a non-coaxial system to solve the deformation problem caused by the large flip angle of the DMD chip and further improve the illumination uniformity based on Scheimpflug principle. The optical efficiency and illumination uniformity of the illumination systems were verified and analyzed. The results indicate that the systems designed by the proposed method can provide a good design scheme and obtain a satisfactory utilization rate of the optical energy and higher uniformity.

High contrast ratio optimized total internal reflection prism for compact medium-wave IR target simulation system

“…According to the modulation principle of the DMD, 17 , 18 combined with the requirements of the illumination system and projection system in the design of TIR prism, 19 , 20 the contrast ratio enhancing OTIR prism should meet the following three conditions. The light beam of the illumination system can be fully reflected in the OTIR prism and uniformly illuminate the DMD, which can pass through the OTIR prism into the projection system after being reflected by the DMD.…”

An imaging homogenizer for DLP-based 3D printer

“…The RTIR prism will cause spot deformation with larger θin; one of these deformations is the lateral magnification to the flattop 9 . A Lambertian source (405nm) with a half angle of 30 degrees was used in the simulation, which nearly matches the practical light source.…”

“…RTIR prism is used to reduce the total track of the DLP engine and to facilitate the design of the imaging system. However, it reduces the flattop uniformity and introduces some deformations to the flattop, such as lateral magnification 9 .…”

Illumination design for high-contrast, high-power UV DLP projector

“…A DLP projector generally consists of three optical sub-systems: (1) The illumination system for reshaping and homogenizing the output from the light source (typically a LED) to achieve a uniform illumination spot of the micromirror array. (2) The projection system for imaging the light reflected by the micromirrors tilted in the on state at the specified magnification and working distance, with maximum image contrast and minimal distortion.…”