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:
Nov. 30, 1976
Filed:
Apr. 03, 1975
Kyozo Uesugi, Izumi, JA;
Mitsuo Yasukuni, Osaka, JA;
Minolta Camera Kabushiki Kaisha, Osaka, JA;
Abstract
A macro-photography varifocal lens assembly is provided for attachment to a camera body. The lens assembly can include a first lens group of negative refractive power and a second lens group of positive refractive power further supplemented by a master or auxiliary lens group of positive refractive power. One of the first and second lens groups are mounted for relative movement to vary the overall focal length of the lens assembly as the lens group moves across a predetermined range of movement. The image plane of the refracted image is continuously shifted from an initial predetermined position at one end of the range of movement towards the object and then away from the object to return to the initial predetermined position at the other end of the range of movement. This relative movement or shift of the image plane towards the object being sufficient to focus an image of an object in a macro-photography range. Various embodiments of the present invention can accomplish the combination of a lens system having two or more focal lengths with an intermediate macro-photography capability.