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:
Oct. 11, 2011
Filed:
May. 08, 2008
Satoshi Kinouchi, Tokyo-to, JP;
Osamu Takagi, Tokyo-to, JP;
Yoshinori Tsueda, Shizuoka-ken, JP;
Toshihiro Sone, Kanagawa-ken, JP;
Koichiro Saito, Shizuoka-ken, JP;
Satoshi Kinouchi, Tokyo-to, JP;
Osamu Takagi, Tokyo-to, JP;
Yoshinori Tsueda, Shizuoka-ken, JP;
Toshihiro Sone, Kanagawa-ken, JP;
Koichiro Saito, Shizuoka-ken, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Toshiba Tec Kabushiki Kaisha, Tokyo, JP;
Abstract
A fixing device includes a heat roller having a degaussing alloy material, an induction heating member for exciting the heat roller, an inverter circuit for giving power at a predetermined frequency to the induction heating member, and a control unit, and when driving at a first drive frequency and fixing small size sheets by continuous passing, a local temperature rise occurs at an end part of the heat roller, and the end part approaches the Curie temperature, and when impedance of the inverter circuit reduces and an excessive current flows in the circuit, the fixing device drives at a higher second drive frequency, thereby increases a resistance of the heat roller by an epidermal effect of magnetic flux, increases an apparent resistance of the inverter circuit, makes it possible to use a flowing current within a normal range, heating a central part of the heat roller, and continues the fixing.