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:
Sep. 20, 2011
Filed:
Nov. 13, 2009
Junji Ishikawa, Moriya, JP;
Junji Ishikawa, Moriya, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
A fixing controller capable of rapidly detecting an excessive temperature rise, even if an abnormal temperature rise takes place in a state that a rotor of a fixing unit, such as a thin-walled roller or belt, stops rotating. A rotating belt is heated by a coil, a belt temperature is detected by a thermistor, and a drive frequency of a driving circuit for driving the coil is controlled by a control circuit. When the temperature detected by the thermistor becomes equal to or higher than a predetermined temperature, the drive circuit is stopped by an excessive temperature rise detecting circuit. The thermistor is heated such that a difference between the temperatures detected by the thermistor when the belt is rotating and when the belt stops rotating becomes equal to or larger than a predetermined temperature difference.