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:
Mar. 18, 1997
Filed:
Jun. 30, 1995
Shigeyuki Uchiyama, Tokyo, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A focus detection device is disclosed that establishes a focus detection algorithm range on photoelectric conversion element arrays and detects the contrast distribution of the output signal strings of the arrays corresponding to this algorithm range. Moreover, the focus detection device determines transformation coefficients for the algorithm range based on a detected contrast distribution and coefficients predefined for some of a plurality of photo-electric conversion elements of the photo-electric conversion element arrays. The focus detection device computes the relative shift amount of the output signal strings corresponding to the algorithm range, and converts the shift amount into a defocus amount of a shooting lens based on the determined transfer coefficients. Moreover, while relatively shifting the pair of output signal strings of the pair of photo-electric conversion element arrays by a specific amount within the predetermined shift range, the invention computes a correlation-amount at each shift position and detects the focus adjustment condition of the shooting lens based on the shift position yielding the minimum correlation amount. The detected focus adjustment condition is determined to have a high level of confidence if the amount of change in the correlation amount in the vicinity of the shift position yielding the relatively minimum correlation amount satisifies specified conditions.