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:
Dec. 23, 1997
Filed:
Dec. 07, 1994
Katsumi Sugimoto, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A thermal fixing device for rising a temperature of a heat roller up to a designated temperature in a short time and a color image forming apparatus using this device. This thermal fixing device comprises a heat roller having a heat source and positioned on the side of a toner image on a recording medium to fix the toner image; a pressurizing member, positioned opposite to the side of the toner image on the recording medium, for pushing the recording medium against the heat roller; a temperature sensor for detecting a temperature of the heat roller; and a control circuit for controlling the heat source of the heat roller by comparing a detected temperature of the temperature sensor with a set temperature, sequentially stepwise increasing the set temperature up to the designated temperature when starting the operation of the device and, at the same time, controlling a generated energy of a plurality of heat sources to sequentially decrease the generated energy thereof. The heat roller includes an elementary tube accommodating a heat source, a rubber member provided along the periphery of the elementary tube, and a heat emission prevention member covering the ends of the tube. The temperature sensor is provided in a position for detecting a temperature of this elementary tube. The heat emission prevention member is formed with a plurality of air holes.