Patent ID: 6198576
Filing Date: 2001-03-06
Classification: G03F

Abstract:
A dioptric projection optical system for projecting an image of a first object onto a second object, the dioptric projection optical system having a numerical aperture of at least 0.63, the dioptric projection optical system comprising:a first lens portion;an aperture stop; anda second lens portion, wherein the first and second lens portions are disposed such that the first lens portion is between the first object and the aperture stop and the second lens portion is disposed between the aperture stop and the second object, wherein the first and second lens portions satisfy the following conditions:-0.000005<PTZ(1)+PTZ(2)<0.000005,and-0.005<PTZ(1)<0.005,where, PTZ(1) is a Petzval sum of the first lens portion and PTZ(2) is a Petzval sum of the second lens portion.