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:
May. 21, 1985
Filed:
Apr. 05, 1982
Applicant:
Inventor:
Mitsuo Yasukuni, Sennan, JP;
Assignee:
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ;
U.S. Cl.
CPC ...
350454 ;
Abstract
A telephoto lens system comprising a front lens group of a positive refractive power fixed on the optical axis and a rear lens group of a negative refractive power is provided. The rear lens group consists, from the object to the image side, of a first positive subunit fixed on the optical axis, a second negative subunit movable along the optical axis and a third positive subunit fixed on the optical axis, the second negative subunit being movable toward the image side for focusing to a closer object. The object side end surface of the first positive subunit is concave and fulfills the following condition in relation with the front lens group: