46.2: Optical System of Ultra‐Thin Rear Projector Equipped with Refractive‐Reflective Projection Optics

Abstract

An ultra-thin DLP TM* rear projector composed of a refractive-reflective projection optics and an off-axis hybrid screen has been designed. The projection optics has extraordinarily large projection angle of 136 degrees with very low distortion, which is also applicable for a video-wall monitor as well as a stand-alone display. Results of prototype projection systems using the technology will be presented.

Analysis and reduction of dark zone in ultra‐thin wedge‐plate displays

“…2(b), if the ray enters the wedge plate at a height h, Eq. (1) can be rewritten as (2) where b is the height of the incident ray at entrance and the wedge thickness of the entrance port is b + h. Equations (1) and (2) are the basic formulas of ray tracing in the wedge plate.…”

“…Currently, rear-projection displays could be realized with a ratio of projector thickness to screen diagonal length of~1:10. 2 Nevertheless, this implementation requires an elaborate projection-lense design 3 and a very unique hybrid (asymmetrical) Fresnel lens. 4 Theoretically, the analysis is difficult because common paraxial optics is generally not applicable.…”

Design of off-axis reflective projection lens using spherical Fresnel surface

“…Hence, the design concept of reflective objective lens is accepted by more and more lens designer. Many reflective projection lens design are reported [3][4][5], Ogawa studied a projection lens layout with four aspheric mirrors [6], the detail design and manufacture performance were put forward. But the manufacture and measurement of large aspheric surfaces are very difficult.…”

Design of objective lens with reflective spherical Fresnel zone plate

“…At present, the design concept of the reflective objective lens is accepted by more and more lens designers. Many reflective objective lens designs are reported [3][4][5], for example, Ogawa J has studied the objective lens layout with four aspheric mirrors [6], and the detailed design and manufacture performance were put forward. However, the manufacture and measurement of large aspheric surfaces are difficult.…”