Projection objective having adjacently mounted aspheric lens surfaces
US7154678B2 · kind B2 · utility
0Cited by
24References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 15, 2005 |
| Grant date | Dec 26, 2006 |
| Priority date | — |
| Expiry date | Mar 15, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70933
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection objective has at least five lens groups (G1 to G5) and has several lens surfaces. At least two aspheric lens surfaces are arranged so as to be mutually adjacent. These mutually adjacently arranged lens surfaces are characterized as a double asphere. This at least one double asphere (21) is mounted at a minimum distance from an image plane (0′) which is greater than the maximum lens diameter (D2) of the objective.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.