The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 22, 1988
Filed:
Feb. 24, 1988
Masamori Makino, Hachioji, JP;
Konica Corporation, Tokyo, JP;
Abstract
A focus detection system detects an in-focus position of a photographing lens on the basis of a phase difference between image signals produced from two focusing portions of an image sensor for focusing an object image, the image sensor being scanned at least two times to produce first image signals corresponding to the object image from a first scanning cycle and second image corresponding to the object image from a second scanning cycle of the image sensor. A detector is provided for detecting maximum and minimum values of the first image signals produced from the two focusing portions obtained in a first scanning cycle of the image sensor. A signal converter converts signal components of the second image signals falling within a range of the maximum and minimum values detected by the detector into digital signals, the second image signals and the signal components being obtained in a second scanning cycle of the image sensor. A processor is responsive to the output from the signal converter for calculating the in-focus position of the photographing lens based on a phase difference between the image signals produced from the two focusing portions of the image sensor in the second scanning cycle, and the lens is moved to an in-focus position responsive to the output of the processor.