Optical design and multi-objective optimization for U-type 2X zoom projection optics

In this research, a newly developed U-type 2X zoom optical lens design for Digital Light Processing (DLP) projector was proposed. With two prisms assembled in a non-coaxial optical system, the design could take advantage of compacting overall volume size. But in this design, the value of Relative Illuminance (RI) at wide angle position seems lower than that of coaxial optical system. If we corrected the design to improve the value of RI, Modulation Transfer Function (MTF) value would become lower relatively. In this study, we integrated the Taguchi method and principal component analysis (PCA) to optimize the multiple quality characteristics (RI and MTF) of this U-type projector lens. With the combination of the methods, a set of optimum design parameters was well selected to balance the values of MTF and RI and improve the MTF 16.42% and RI 1.54%. It was concluded that the integration of the Taguchi method and PCA succeeded in optimizing the MTF and RI values, and the U-type projector lens could be well designed without sacrificing system performance.