Design of a bright polarized head-mounted projection display

In optical see-through head-mounted displays, it has been a common challenge that the displayed image lacks brightness and contrast compared with the direct view of a real-world scene. Consequently, such displays are usually used in dimmed lighting conditions, which limits the feasibility of applying such information displays outdoors or in scenarios where well-lit environments, such as in operation rooms, are required. The lack of image brightness is aggravated in the design of a see-through head-mounted projection display (HMPD). For instance, the overall flux transfer efficiency of existing HMPD designs is less than 10%. The design of a polarized head-mounted projection display (p-HMPD) is presented. The images of a p-HMPD system can potentially be three times brighter than those in existing HMPD designs. It is further demonstrated that the p-HMPD design is able to dramatically improve image brightness, contrast, and color vividness with experimental results. Finally, the design of a compact optical system and helmet prototype is described.