| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a reflection type projection optical apparatus wherein influence of an installation error of a reflection mirror on imaging characteristics is reduced. <P>SOLUTION: In the projection optical apparatus provided with: a first element (i=1) having a first reflection surface reflecting light emitted from an object (i=0) as reflection light; and a second element (i=2) having a second reflection surface reflecting and imaging the reflection light on an image surface (i=3), at least a spherical aberration, a coma aberration and an astigmatic aberration are compensated, the first element (i=1) has a non-spherical reflection surface as the first reflection surface, and the second element (i=2) has a non-spherical reflection surface as the second reflection surface. The first element (i=1) and the second element (i=2) preferably have non-spherical reflection surfaces which are rotationally symmetrical with respect to an optical axis. A paraxial marginal light beam of the first element (i=1) more preferably has a light beam height ratio γ<SB>1</SB>in a range of, e.g., 0.5≤γ<SB>1</SB><1. <P>COPYRIGHT: (C)2007,JPO&INPIT |
