Patent · US Expired

Automatic focusing device with frequency weighted amplification

US4510384A · kind A · utility

10Cited by
2References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 16, 1982
Grant dateApr 9, 1985
Priority date
Expiry dateAug 16, 2002

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03B3/10
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An optical system is automatically focussed by deriving an electrical signal which has a frequency distribution corresponding to the spatial frequency distribution of an image received from a focussing lens; applying to the electrical signal an amplification which is greater at high frequencies than at low frequencies; and adjusting the optical system to maximize the amplified signal.

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