Patent ID: 6674513
Filing Date: 2004-01-06
Classification: G02B,G03F

Abstract:
A dioptric projection optical system for forming an image of a pattern on a first surface, onto a second surface by action of radiation-transmitting refractors, comprising:a front lens unit having a positive refracting power, located in an optical path between said first surface and said second surface; a rear lens unit having a positive refracting power, located in an optical path between said front lens unit and said second surface; and an aperture stop located in the vicinity of a rear focal point position of said front lens unit; said projection optical system being telecentric on the said first surface side and on the said second surface side, wherein the following condition is satisfied: 0.0652/L<0.125, where f2 is a focal length of said rear lens unit and L is a distance from said first surface to said second surface.