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. 27, 1989
Filed:
Jun. 23, 1986
Applicant:
Inventors:
Nozomu Kitagishi, Tokyo, JP;
Hiroki Nakayama, Kanagawa, JP;
Shigeyuki Suda, Tokyo, JP;
Jun Hattori, Kanagawa, 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 variable focal length objective having a plurality of lens units with at least one unit separation being varied to vary the focal length of the entire system, in which at least one of the plurality of lens units has at least gradient-index lens having a refractive index distribution of the form: N(h)=N.sub.0 +N.sub.1 h.sup.2 +N.sub.2 h.sup.4 +N.sub.3 h.sup.6 + . . . where h is the height from the optical axis, N.sub.0 is the refractive index on the optical axis, and N.sub.1, N.sub.2, N.sub.3, . . . are constants, satisfying the following conditions: