Patent · US Expired

Automatic focusing camera

US4873543A · kind A · utility

10Cited by
3References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 8, 1987
Grant dateOct 10, 1989
Priority date
Expiry dateOct 8, 2007

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B7/36
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An automatic focusing camera includes a sensor for detecting an amount and a direction of difference between an image forming position of light from an object being photographed and a film surface to drive a taking lens in response to the measured outputs and focus determining capability which gives a decision of in-focus when the amount of difference is less than a first automatic focusing threshold. A focusing operation is achieved such that, comparing the amount of difference determined by the sensor with a second automatic focusing threshold of a standard value which is larger than the first automatic focusing threshold, when the amount is less than the second threshold and a direction of difference last measured and that presently measured are the same, a taking lens driving is continued to complete a focusing operation and when the directions are different from each other, the measurement is resumed after the next driving of the taking lens even when the amount is less than the second threshold.

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