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. 04, 2012
Filed:
Jun. 21, 2010
Kiriko Chosokabe, Tokyo, JP;
Eiji Nemoto, Tokyo, JP;
Norikazu Okada, Kanagawa, JP;
Takuma Kasai, Kanagawa, JP;
Kiriko Chosokabe, Tokyo, JP;
Eiji Nemoto, Tokyo, JP;
Norikazu Okada, Kanagawa, JP;
Takuma Kasai, Kanagawa, JP;
Ricoh Company, Limited, Tokyo, JP;
Abstract
An image forming apparatus includes a halogen heater in a fixing unit; an AC source applying an alternating voltage to the halogen heater; a half-wave control unit that performs the heater half-wave control to control the halogen heater on the half-wavelength basis, according to a heater-on/off pattern set for each control cycle having a predetermined length; a heater-off-time measuring unit that measures heater-off period of time; a phase-control-execution determining unit that determines, based on the measured heater-off period of time, whether the heater phase control is to be performed on the alternating voltage, the phase control being performed by shifting phase of the alternating voltage; and a phase control unit that performs, when the phase control is determined to be performed, the phase control only for a period of time depending on the measured heater-off period of time after switch-on of the heater and before execution of the half-wave control.