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:
Dec. 16, 1997
Filed:
Jun. 07, 1995
Kiyotaka Inadome, Kawasaki, JP;
Wataru Tatsuno, Yokohama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An internal focusing zoom lens comprises a first lens group of positive refracting power, a second lens group of negative refracting power, a third lens group of positive refracting power and a fourth lens group of positive refracting power disposed in the named order from the object side, in which at least the first lens group, the third lens group and the fourth lens group move toward an object along the optical axis during zooming from wide angle to telephoto such that an air gap increases between the first lens group and the second lens group, an air gap decreases between the second lens group and the third lens group and an air gap decreases between the third lens group and the fourth lens group, in which the second lens group moves toward the object along the optical axis during focusing, and which satisfies various conditions.