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:
Apr. 30, 1991
Filed:
Mar. 27, 1989
Applicant:
Inventors:
Hiroki Nakayama, Kanagawa, JP;
Nozomu Kitagishi, Tokyo, JP;
Jun Hattori, Kanagawa, JP;
Shigeyuki Suda, Tokyo, JP;
Akihisa Horiuchi, Tokyo, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ; G02B / ;
U.S. Cl.
CPC ...
350427 ; 350413 ; 350423 ; 350426 ;
Abstract
A zoom lens including at least two lens units of which the front one is of positive refractive power and the rear one is of negative refractive power, the units being axially movable to decrease their separation in zooming from the wide angle to the telephoto end. At least one of the lens units is provided with at least one refractive index distribution type lens arranged on a common optical axis of the other lenses in order to achieve a great advance in compactness.