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:
Aug. 18, 1998
Filed:
Jun. 10, 1997
Yoshiharu Shiokama, Chiba-ken, JP;
Seiichi Yasukawa, Yotsukaido, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An automatic focusing device for a camera capable of accommodating an interchangeable zoom lens which prevents inadvertently performing a moving subject tracking lens drive control when the zoom lens causes focus shift as a result of a zooming operation. The automatic focusing device operates in a first drive mode in which movement of the subject in the optical axis direction is detected and the moving subject is tracked by providing compensation for the drive amount of the lens according to the movement of the subject, and a second drive mode in which movement of the subject in the optical axis direction is not detected and compensation for the drive amount of the lens is not provided. A determination that the zoom lens causes focus shift during a zooming operation is made when the object distance is within a specified distance range, and a focus shift signal is output when focus shift will occur. An inhibition device inhibits the lens drive in the first lens drive mode in response to the focus shift signal.