DIOPTRIC SYSTEM AND PROJECTION-TYPE IMAGE DISPLAY APPARATUS

摘要

Disclosed are projection-type image display apparatus, and a projection optical system provided in the same.  The projection optical system has a dioptric system and a catoptric system.  In the dioptric system, a lens (non-circular lens) provided on a catoptric-system-facing side has a non-circular shape that constitutes a part of a virtual circle area centered on the optical axis center of the dioptric system.  That is, the non-circular lens has a shape obtained by cutting out a part of the virtual circular lens having the same optical axis center as the dioptric system.