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:
Mar. 18, 1980
Filed:
Aug. 28, 1978
Mitsuo Yasukuni, Sakai, JP;
Toshinobu Ogura, Tondabayashi, JP;
Takanobu Omaki, Sennan, JP;
Masahide Tanaka, Toyonaka, JP;
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
A constant magnification zoom lens system is provided that has the capability of permitting a predetermined desired constant magnification of an image during a zoom operation. A variator lens group for varying the focal length of the lens system and a compensator lens group for controlling the position of an image formed by the lens system is provided. Pairs of cam and follower assemblies can be provided in the barrel mechanism to control the movement of the respective compensator lens group and variator lens group so that the position of an image of a fixed object is maintained within a predetermined depth of focus in a normal zooming mode of operation and also the position of an image of a moving object can be maintained within a predetermined depth of focus in response to any variation of focal length to provide a constant magnification photography mode.