Patent ID: 9274327
Filing Date: 2016-03-01
CPC Classification: G02B,G03F

Claim Text:
1. A projection objective configured to image an object field into an image field, the projection objective comprising: a multiplicity of lenses; a concave mirror; a first deflection mirror in optical proximity to a first field plane of the projection objective, the first deflection mirror configured to deflect radiation from the object field to the concave mirror; a second deflection mirror in optical proximity to a second field plane of the projection objective, the second deflection mirror configured to deflect radiation from the concave mirror to the image field, wherein: the second field plane is optically conjugate to the first field plane; relative to an optical axis of the projection objective, the first deflection mirror is tilted about an axis perpendicular to the optical axis and parallel to a first direction; relative to the optical axis of the projection objective, the second deflection mirror is tilted about an axis perpendicular to the optical axis and parallel to the first direction; the first deflection mirror is displaceable parallel to the first direction between first and second positions; and the second deflection mirror is displaceable parallel to the first direction between first and second positions.