Method of evaluating imaging performance
US6563573B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 13, 1999 |
| Grant date | May 13, 2003 |
| Priority date | — |
| Expiry date | Sep 13, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7088
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of evaluating an imaging performance of an imaging optical system includes providing a member having a measurement mark with a predetermined surface level difference, illuminating the member having the measurement mark through the imaging optical system, and receiving reflection light from the illuminated measurement mark again through the imaging optical system. A detection signal is produced based on the measurement mark, illuminated through the imaging optical system, wherein the detection signal is produced while changing a focus within a depth of focus of the imaging optical system. A positional deviation is measured on the basis of the detection signal, and the imaging performance is evaluated of the imaging optical system on the basis of a change in a measured value of the positional deviation measurement with respect to a change in the focus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.