| 摘要 |
PROBLEM TO BE SOLVED: To provide a relatively compact cata-dioptric type projection optical system that has superior imaging performance having various aberrations such as a chromatic aberration and a field curvature excellently corrected, and can secure a large effective image-side numerical aperture by excellently suppressing reflection loss on an optical plane.SOLUTION: A cata-dioptric type projection optical system which forms a reduced image of a first plane R on a second plane W includes at least two reflecting mirrors CM1, CM2 and transparent members L11-L217, and has an arcuate effective imaging region not including an optical axis AX of the projection optical system; and a condition of 1.05<R/Y<12 is satisfied, where R is the radius of curvature of an arc defining the effective imaging region and Yis a maximum image height on the second plane. |
