Projection optical apparatus
US4801977A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 1988 |
| Grant date | Jan 31, 1989 |
| Priority date | — |
| Expiry date | May 24, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70883
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection optical apparatus comprises a projection optical system for projecting the image of an object onto a substrate, data collecting means for obtaining data regarding a factor which causes a variation in the optical characteristic of the projection optical system, adjusting means for adjusting the relation between the substrate and the image of the object relative to the variation in the optical characteristic of the projection optical system, means for determining the amount of adjustment by the adjusting means in accordance with a model formula using a predetermined parameter on the basis of the data obtained by the data collecting means, means for independently measuring the variation in the optical characteristic of the projection optical system, and means for correcting the parameter of the model formula on the basis of the result measured by the measuring means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.