Patent ID: 6469827
Filing Date: 2002-10-22
Classification: G02B,G03F,G21K

Abstract:
A condenser system for use with a ringfield camera comprising:a small compact source of continuous spectrum of radiation light; collector mirrors comprising at least two substantially equal radial segments of a parent aspheric mirror, each having one focus at the radiation source and a curved line focus filling the object field of the camera at the radius of the ringfield and each producing a beam of radiation; a corresponding number of sets of correcting mirror means which are capable of translation or rotation, or both, such that all of the beams of radiation pass through the entrance pupil of the camera and form a coincident arc image at the ringfield radius, wherein at least one of the correcting mirrors of each set, or a mirror that is common to said sets of mirrors, from which the radiation emanates, is a concave relay mirror that is positioned to shape a beam segment having a chord angle of about 25 to 85 degrees into a second beam segment having a chord angle of about 0 to 60 degrees; and one or more diffractive spectral filters for separating first radiation light having a particular wavelength from the continuous spectrum of radiation light.