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:
Feb. 04, 1997
Filed:
Jun. 07, 1995
Yoshiharu Shiokama, Kawasaki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An automatic focusing device in which when a lens shifting range is arbitrarily limited and set with respect to the distance to a target object, the defocus amount and lens position are automatically detected, and the image plane shifting amount corresponding to the limited lens shifting range is calculated. Then, the corresponding image shifting amount and the detected defocus amount are compared. As a result of such comparison, if the defocus amount is found smaller, i.e., the target object is within the lens shift limiting range, the lens is shifted by the lens shifting amount thus calculated so as to perform focusing. If the defocus amount is found larger, i.e., the target object is outside the lens shift limiting range, the driving of the driving device is disabled so as not to shift the lens. If the defocus amount is found larger and the lens shifting is disabled, the defocus amount is again detected. The image shifting amount and lens shifting amount are calculated by the standard image plane shifting conversion coefficient and correction coefficient.