Patent · US Expired

Automatic focusing device of a microscope

US4342905A · kind A · utility

79Cited by
3References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 21, 1980
Grant dateAug 3, 1982
Priority date
Expiry dateAug 21, 2000

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B21/244
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An automatic focusing device of a microscope having an objective lens and a stage on which a specimen is placed comprises distance varying means for varying the relative distance between the objective lens and the stage, distance detecting means for producing a distance output corresponding to said distance, photoelectric detector means for photoelectrically detecting a high frequency component of the space frequency component of the image of the specimen on the stage by the objective lens, judging means for judging whether or not a predetermined peak smaller than a maximum peak exists in the output of the photoelectric detector means within a predetermined distance range from a first distance output of the distance detecting means when the output of the photoelectric detector means assumes said maximum peak and for producing an in-focus output when said predetermined peak exists, and means for determining said relative distance on the basis of said in-focus output.

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