Patent · US Expired

Monitoring focus of a lens imaging system based on astigmatism

US6208748A · kind A · utility

14Cited by
3References
23Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 5, 2000
Grant dateMar 27, 2001
Priority date
Expiry dateJan 5, 2020

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03F7/70641
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

Methods for determining a focus position of a lens system based on astigmatism. The methods can be used to monitor the focus of the lens system or to determine the flatness of a surface.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.