Multiple mirror catadioptric optical system
US5515207A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 3, 1993 |
| Grant date | May 7, 1996 |
| Priority date | — |
| Expiry date | Nov 3, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70275
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A reduction projection system (10) characterized by large numerical aperture has an unobscured optical path without the need to resort to truncated lens elements. The system includes first and second reduction stages. The first reduction stage includes a first mirror group (20) and a first lens group (30). The second reduction stage includes a second mirror group (40) and a second lens group (50). Together, the first mirror group and the first lens group form an intermediate reduced image of the object at an intermediate image region (70). The second mirror group and the second lens group form a further reduced image at an image plane (15).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.