Projection optical system and projection exposure apparatus using the same
US6867922B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 2000 |
| Grant date | Mar 15, 2005 |
| Priority date | — |
| Expiry date | Sep 2, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70741
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection optical system includes a plurality of positive lens groups having a positive refractive power, and at least one negative lens group having a negative refractive power, wherein, when L is a conjugate distance of the projection optical system and φ0 is the sum of powers of the or each negative lens group, a relation |L×φ0|>17 is satisfied, wherein, when h is a height of an axial marginal light ray and hb is a height of a most abaxial chief ray, at least two aspherical surfaces are formed on surfaces which satisfy a relation |hb/h|>0.35, wherein, when ΔASPH is an aspherical amount of each aspherical surface, a relation |ΔASPH/L|>1.0×10−6 is satisfied, and wherein the at least two aspherical surfaces include regions in which, from a central portion toward a peripheral portion of the surface, their local curvature powers change with mutually opposite signs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.