 Image Number 4 for United States Patent #7619722.
A method for replacing a lens having refractive power in a first projection optical system includes measuring a wavefront of measuring light passing through the first projection optical system in a state in which the lens having refractive power or a master lens is mounted in the first projection optical system, measuring a wavefront of measuring light passing through a second projection optical system in a state in which the master lens or an alternative lens is mounted in the second projection optical system, processing the alternative lens in accordance with measurement results, and replacing the lens having refractive power in the first projection optical system with the processed alternative lens.
|