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:
Jun. 04, 2002
Filed:
Jul. 26, 2000
Hiromitsu Fukuda, Chiyoda, JP;
Toshio Ogiso, Tsuchiura, JP;
Masaru Nakano, Tsukuba, JP;
Kazuo Kikuchi, Hitachi, JP;
Katsumi Kumada, Kitaibaraki, JP;
Chikara Hiraoka, Hitachi, JP;
Katsuyoshi Onose, Hitachi, JP;
Hitoshi Furuyama, Hitachi, JP;
Takashi Kakuhashi, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A fixing device in an image formation apparatus has a heating roller and a backup roller. These rollers are each coated with single silicone rubber layers around the respective peripheries of their core bars. This silicone rubber has a volume resistance value of 10 &OHgr;·cm or more. The heating roller is charged with electricity of the same polarity as the polarity of toner particles due to frictional electrification caused at the time of feeding of a recording medium. The heating and the backup roller are polarized reverse to the polarity of the recording medium. A quantity of charged electricity on the backup roller is made larger than that on the heating roller. This permits the image formation apparatus to prevent offset from occurring at the time of fixing a toner image onto the recording medium to cope with various types of recording media.