Method and apparatus for setting an illumination optical unit
US8345219B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 2012 |
| Grant date | Jan 1, 2013 |
| Priority date | — |
| Expiry date | May 11, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70266
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for setting an illumination optical unit involves determining an actual value of an intensity-weighted illumination parameter of the illumination optical unit for multiple field points and for multiple illumination angles. The influence of a deformation of at least one of the optical surfaces of the illumination optical unit on the at least one illumination parameter is then determined. A desired value of the illumination parameter is then predefined. A desired form of the at least one optical surface is determined so that the actual value of the illumination parameter corresponds to the desired value of the illumination parameter within predefined limits. Finally, the optical surface is deformed with the aid of at least one actuator so that an actual form of the optical surface corresponds to the desired form.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.