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. 12, 2009
Filed:
Sep. 15, 2004
Toshiaki Kagawa, Nara, JP;
Hiroshi Kida, Yamatokoriyama, JP;
Takashi Yamanaka, Yamatokoriyama, JP;
Tetsunori Mitsuoka, Tondabayashi, JP;
Toshiaki Kagawa, Nara, JP;
Hiroshi Kida, Yamatokoriyama, JP;
Takashi Yamanaka, Yamatokoriyama, JP;
Tetsunori Mitsuoka, Tondabayashi, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A fixing device () of the present invention includes a fixing roller () contacting a toner image surface, and a pressure roller () contacting a surface opposite to the toner image surface. In the fixing device (), a printing sheet (P) on which unfixed toner image is formed passes through a fixing nip portion (Y) where the fixing roller () and the pressure roller () are in contact with each other, so that the above-described toner image is fixed on the printing sheet (P). The fixing device () further includes a control circuit () which controls heater lamps (to) so that a surface temperature of the pressure roller () is in a temperature range defined by a cold offset occurring boundary temperature (Thc) of the fixing roller () and/or a hot offset occurring boundary temperature (Thh) of the fixing roller (). With this, it is possible to suppress or prevent a transfer of toner to a pair of rollers (a transfer from the back of the printing sheet to the pressure roller, a transfer from the pressure roller to the fixing roller).