Three-dimensional display apparatus and oblique projection optical system

Abstract

An oblique projection optical system is provided with a first group lens system, a second group lens system and a third group lens system that are placed in succession from a short conjugate length focal surface, and each lens system has a plurality of single lenses. The first group lens system contains a beam regulator to form a telecentric structure. The second group lens system is set to have a great tilt decentration and a parallel decentration with respect to the first group lens system. The third group lens system is set to have a great tilt decentration and a parallel decentration with respect to the second group lens system. In this manner, instead of making the lenses decentered inside each lens system, the respective lens systems are made decentered from each other; thus, the resulting projection device is easily manufactured, and makes it possible to correct the distortion aberration and focal position on the screen surface, and to project an image with high precision. Therefore, it becomes possible to display a three-dimensional image with high precision.

Dependencies are inferred from the claim text.