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. 01, 1987
Filed:
Apr. 23, 1984
Hidenori Terasawa, Kawasaki, JP;
Nippon Kogaku K. K., Tokyo, JP;
Abstract
A zoom lens in which fluctuation of lateral chromatic aberration is small has, in succession from the object side, a first group of positive refractive power including at least one positive lens, a second group of negative refractive power including at least one negative lens, and an aperture stop disposed closer to the image plane than the second group. Each of the groups is moved on the optic axis during magnification change so that the distance between the first group and the second group becomes greater and the distance between the second group and the aperture stop becomes smaller as the focal length of the entire system becomes longer. At least one of negative lenses constituting the second group is formed of a material which satisfies the following conditions: