Patent ID: 9606443
Date: 2017-03-28
CPC Classifications: G02B,G03F,H01L

Claim:
1. A projection optical system which projects a reduced image of an object arranged on a first surface onto a second surface through liquid, the projection optical system comprising: a first imaging optical system, which forms an intermediate image of the object with light from the object; and a second imaging optical system, which forms the reduced image with light from the intermediate image, wherein the first imaging optical system is a catadioptric optical system including an even number of reflective mirrors, the second imaging optical system is a dioptric optical system including no shield area on an exit pupil, an optical axis of each optical element of the first imaging optical system and of the second imaging optical system is arranged on a single optical axis, the second imaging optical system comprises a planoconvex lens arranged closest to the second surface in the second imaging optical system so as to come into contact with liquid, a number of 70% or more among a plurality of transmissive members of the second imaging optical system being formed with silica, and the reduced image is an inverted image of the object and formed in a region which does not include the single optical axis.