Patent ID: 7470033

Claim:
A projection-optical system that forms, on a second surface, a reduced image of a first surface, the system comprising: a first reflective image-forming optical system situated and configured to form an intermediate image of the first surface, based on light from the first surface; a second reflective image-forming optical system situated and configured to form the reduced image on the second surface, based on light from the intermediate image; the first reflective image-forming optical system comprising, in order of light incidence from the first surface, a first reflective mirror having a concave reflective surface, a second reflective mirror having a convex reflective surface, a third reflective mirror, and a fourth reflective mirror having a concave reflective surface; the second reflective image-forming optical system comprising, in order of light incidence from the intermediate image, a fifth reflective mirror having a concave reflective surface, a sixth reflective mirror, a seventh reflective mirror having a convex reflective surface, and an eighth reflective mirror having a concave reflective surface; and satisfying conditions 1<RM 2 /H 0 <6 and 4<RM 3 /H 0 <13, wherein RM 2 is the absolute value of a center radius of curvature of the reflective surface of the second mirror, RM 3 is the absolute value of a center radius of curvature of the reflective surface of the third mirror, and H 0 is a maximum object height on the first surface.