Patent · US Expired

Automatic focusing mechanism

US4005442A · kind A · utility

2Cited by
3References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 26, 1974
Grant dateJan 25, 1977
Priority date
Expiry dateDec 26, 1994

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B7/32
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An automatic focusing mechanism for adjusting the focus setting of the objective lens of an optical instrument such as a photographic camera. The adjustable focusing cell of the objective lens is coupled to a pivotal reception means so that the focus setting of the objective lens is maintained coincident with the distance between the camera and an object to be photographed when the longitudinal axis of the reception means is in alignment with a reflected light beam image transmitted from the camera to the object from an emission means spaced from the reception means. A rangefinder circuit controls the pivotal motion of the reception means so as to maintain its longitudinal axis in alignment with the reflected light beam image through variations in camera-to-object distance.

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