OBLIQUE PROJECTION OPTICAL SYSTEM AND PROJECTION TYPE VIDEO DISPLAY APPARATUS USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a compact projection type video display apparatus that may include an oblique projection optical system with ultra-short projection distance and a plane mirror, and prevents trapezoidal distortion due to oblique projection and has a favorable focus performance.

SOLUTION: The projection type video display apparatus is provided with the oblique projection optical system composed of a plurality of lenses. The lens arranged closest to a projection plane is disposed at a position where a video vertical direction effective region through which a light flux passes does not contain an optical axis shared by the greatest number of lenses among optical axes of the plurality of lenses. A light path folding plane mirror is arranged at a predetermined angle with respect to the optical axis between the lens and the projection plane so as to obtain an enlarged video obtained by a video light flux folded by the plane mirror in a video display face direction.

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