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. 31, 2016
Filed:
Feb. 12, 2014
Konica Minolta, Inc., Chiyoda-ku, JP;
Seiichi Kirikubo, Toyohashi, JP;
Masahiro Kamiya, Toyohashi, JP;
Takahiro Tsujimoto, Toyokawa, JP;
Yutaka Yamamoto, Shinshiro, JP;
Hidenori Mine, Toyohashi, JP;
Nobuhiro Matsuo, Toyokawa, JP;
KONICA MINOLTA, INC., Chiyoda-ku, Tokyo, JP;
Abstract
An image forming apparatus having: a power source applying alternating current voltage to the magnetizing coil; a demagnetizing coil switchable between a conductive state and a cutoff state, and when in the conductive state, cancelling out a portion of a magnetic flux produced by the magnetizing coil; a contact switch and a semiconductor switch electrically connected in parallel, and, in combination, bringing the demagnetizing coil into the conductive state or the cutoff state; and a control unit opening or closing the switches separately. The control unit: opens or closes the semiconductor switch in synchronization with a zero-crossing of the alternating current voltage at least when the contact switch is open; opens or closes the contact switch only when the semiconductor switch is closed; and opens the semiconductor switch when the demagnetizing coil brought into the conductive state by the contact switch needs to be maintained in the conductive state.