| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a projection objective which secures a space sufficient for mounting an optical element particularly in the front portion of an objective. <P>SOLUTION: A projection objective includes: object planes (20, 100, 300, 2103) by which object visual fields are formed; an incident pupil (VE); a mirror image forming incident pupil (RE) within a mirror image forming incident pupil plane (103) obtained by forming the incident pupil (VE) into a mirror image within the object planes; image planes (21, 102, 302, 2102); an optical axis (HA); and at least a first mirror (S1) and a second mirror (S2). A background focus of the incident pupil of the projection objective is negative, principal rays (CR, CRP) which are generated from the central points of the object visual fields and traverse the objective from the object planes to the image planes intersect with the optical axis (HA) at least at one cross point (CROSS), and geometric positions of all cross points (CROSS, CROSS1, CROSS2) are present between the image planes (21, 102, 302, 2102) and the mirror image forming incident pupil plane (103). <P>COPYRIGHT: (C)2013,JPO&INPIT |
