| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of a failure in fixing and the wrinkles of a paper sheet caused by the unevenness in an axial direction of the nip width between a heating roller and a pressure roller, in a fixing device for heating/pressing the paper sheet to which a toner image is transferred, so as to melt and press-fix the toner image on the paper. SOLUTION: The fixing device is provided with two backup rollers 3 rotated while coming into contact with the periphery of the pressure roller 2 and plural bearing members 4 for pressing the pressure roller 2 on the heating roller 1, with these backup rollers 3. The bearing members 4 are set to press the backup rollers 3 stronger in the vicinity of the central part of the pressure roller 2 than both end parts of it Thus, the press-contact force of the pressure roller 2 with the heating roller 1 is made almost equal in the axial direction and a uniform nip width can be obtained. Moreover, a cylindrical pressure rotary body and a nearly cylindrical press-contact member for pressing this pressure rotary body on the heating roller inside the pressure rotary body are provided and the press-contact member can be constituted to make the diameter of the central part larger than that of both end parts. |
