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:
Sep. 21, 1999
Filed:
Oct. 15, 1996
Applicant:
Inventors:
Koushi Yoshibe, Kawasaki, JP;
Yoshiharu Shiokama, Chiba-ken, JP;
Assignee:
Nikon Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B / ; G03B / ;
U.S. Cl.
CPC ...
396 62 ; 396 63 ; 396 79 ;
Abstract
A lens barrel and a camera system are capable of precisely calculating a photographic magnification and a field range. The lens barrel having a focusing or zooming movable lens unit is stored with effective focal length data corresponding to a position of the movable lens unit, detects the position of the movable lens unit, outputs the corresponding effective focal length data and calculates the photographic magnification and the field range. An accuracy of a calculated value is thereby enhanced enough not to cause an underexposure on the whole or the underexposure in a peripheral portion as compared with a central portion.