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:
Jun. 02, 1998
Filed:
Nov. 26, 1996
Kiyotaka Inadome, Kawasaki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A zoom lens system in which a movement locus of a focusing lens unit is defined by synthesizing a focus cam and a zoom compensation cam so as to achieve an in-focus state by a substantially constant amount of rotation for an identical object distance independently of a zooming state. In zooming, an amount of movement of the focusing lens unit is defined by a combination of the focus cam and the zoom compensation cam. An amount of movement of a non-focusing lens unit is defined by a combination of a zoom cam and the zoom compensation cam. In focusing, the amount of movement of the focusing lens unit is defined by the focus cam. The zoom lens system satisfies specified formulas so that the number of data of specific coefficients required for auto-focusing can be reduced, and an error upon calculation of the lens driving amount of the focusing lens unit using stored specific coefficients in correspondence with a detected defocus amount can be reduced.