Design of a dual-focal-plane head-up display system using double freeform mirrors

This paper presents the design of a dual-focal-plane head-up display (HUD) system utilizing double freeform mirrors. The system is specifically developed for automotive applications, aiming to enhance driving safety and experience by projecting vehicle information within the driver’s line of sight. Compared to the traditional WHUD, the ARHUD offers a broader field of view and a greater virtual image distance. If the ARHUD system has double focal planes, it can separately display basic and interactive driving information to drivers, which is currently a significant research direction in the ARHUD system design. The proposed design only uses double freeform mirrors and uses a single display source for both focal planes, thus reducing the overall system complexity, assembly difficulty, and cost. Detailed design methods and results are discussed, showcasing the system’s good imaging performance and compact structure, which provide valuable insights for the development of next-generation dual-focal-plane HUDs for vehicles. The proposed system demonstrates significant advancements in reducing fabrication and testing difficulties compared to traditional dual-focal-plane HUD designs. The study’s findings contribute to the future development of dual-focal-plane head-up display systems.