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. 09, 1986
Filed:
Dec. 17, 1984
Yasumasa Tomori, Sakado, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
Cam grooves for displacing lenses of an optical system in which lenses or lens groups are displaced in parallel to an optical axis by a lens-operating ring mounted on a support barrel rotatable about the optical axis, but not shifted in parallel to the optical axis. The cam grooves are provided by obtaining the maximum lengths of displacement of vari-focal lenses, among the lengths of displacement of the one or more lenses or one more lens groups, in respective equal-difference minute ranges between respective changed focal lengths, over the entire range of a train of varying focal lengths or photographic distance; and by applying lead angles as slope of cam grooves to the respective maximum lengths of displacement of the lenses.