| 摘要 |
PROBLEM TO BE SOLVED: To provide a fixing device where a narrow nip width is provided at warming-up, thereby, capable of contributing to the reduction of a warmup time, and also, capable of securing a wide nip width at a fixation process, dispensing with the installation of a special lifting device or the like, and to provide an image forming apparatus. SOLUTION: A nip part 17 is formed with the press contact of a heat belt 18 with a pressure roller 19, and a heat source 20 for heating the heat belt 18 is installed at the inside of the heat belt 18, a pressure support 21 that slides in contact with the inside surface of the heat belt 18 so as to enlarge the nip width H1 at the nip part 17 along the rotating direction of the heat belt 18 is provided, and also, the pressure support 21 is constituted of the aggregate of two kinds of thermal deformation members 22 and 23 having different thermal expansion coefficients. By having such a constitution, due to a difference in thermal expansion coefficient between the members 22 and 23, the pressure support 21 deforms so that the nip width H1 of the nip part 17 is enlarged when being heated by the heat source 20. COPYRIGHT: (C)2008,JPO&INPIT
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