Design of a high-resolution dual-mode optical system for automotive color projection

To meet the high-resolution and dual-mode projection requirements for automotive exteriors, a color projection optical system based on digital light processing (DLP) technology has been designed. An innovative dual-mode switching mechanism based on overall system rotation is proposed, enabling imaging on two mutually perpendicular planes and significantly expanding projection functionality and application scenarios. Meanwhile, a folded optical path structure is adopted to effectively reduce the axial length, meeting the compact space constraints of in-vehicle applications. The projection objective formed by all-glass spherical lenses balances image quality and cost-effectiveness. The illumination unit, optimized through imaging methods, achieves illuminance uniformity exceeding 93% and optical efficiency above 80%. The design results show that the modulation transfer function is greater than 0.5 at 47 lp/mm for the system in both projection modes. Lateral chromatic aberration is less than 5 µm. Lateral illuminance uniformity is from 0.8 to 1.2, and the optical efficiency is greater than 30%, which meets the design requirements greatly. The system overcomes the limitations of traditional automotive projection systems-low-resolution and single-mode projection-offering significant application value.