At least, it has the portable possibility one optical element for two positions at least, optical subsystem for the especially projection exposure device

摘要

There is provided an optical system including an optical element having a first used area and a second used area on which impinge rays of a light bundle, and a device for moving the optical element between a first position and a second position. The light bundle impinges on the first used area when the optical element is in the first position, and light bundle impinges on the second used area when the optical element is in the second position.