Optical System Design Of Micro-Projector

With fast technology development, the requirement of projector will not be limited only on its performance. Its portability and maneuverability will be paid more attention. Consequently, micro-projector will be mainly developing direction. Many manufactures compete to invest on micro-projector production.By the comparison of projector elements performance, LED is selected for projecting source, and LCOS chip for micro-display. The illuminating method of the micro-display element is in described detail.Based on calculation of optical parameters, the projection lens is selected and analyzed. The inverted telephoto lens is applied finally. From the initial structure, the projection lens is optimized by ZEMAX software. After optimization the objective is only composed of five-elements. The low-cost and high transmittance is realized. The on-axis and off-axis optical system transfer function are both above 0.5 at cut-off frequency. The distortion is less than 1%.The high quality image is acquired. By using image space telecentric optical path the illumination uniformity is more than 70%. The total length of the optical system is less than 51mm.The requirement of compact and small size for the micro- projector is achieved.