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:
Aug. 20, 1991
Filed:
Jan. 19, 1990
Yasuhiro Kusuda, Osaka, JP;
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
In a multi-color copying apparatus including a plurality of developing units containing developers in different colors, respectively, the improvement comprising: said developing units each including a magnet roller, a rotatable sleeve roller and a changeover means for changing over each of said developing units between a developing state and a nondeveloping state; in at least one of said developing units disposed downstream of the remaining ones of said developing units in a direction of displacement of a photosensitive member, said changeover means including a first means for effecting angular displacement of said magnet roller between developing and nondeveloping positions at which one of magnetic poles of said magnet roller confronts and does not confront said photosensitive member, respectively, and a second means for turning on said sleeve roller for its rotational drive such that at the time of changeover of said one of said developing units from the nondeveloping state to the developing state, said second means is actuated upon lapse of a predetermined time period after actuation of said first means.