| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that is simple in structure and prevents formation of wrinkles and poor fixation of an envelope-shaped recording medium. <P>SOLUTION: An image forming apparatus 1 comprises: a pressure mechanism 50 for providing a nip pressure at a nip part N by pressure-contacting a pressure roller 19 with a heating roller 18; a detection member 81 for detecting passage of a recording medium 9 at a predetermined position to the nip part N; a switching member 55 for changing the nip pressure at the nip part N; and a switching controller 101 for controlling the switching member 55 so as to change the nip pressure at the nip part N. When an envelope-shaped recording medium 9 is fixed and a predetermined delay time elapses after the passage of the recording medium 9 is detected with a detection member 81, the switching controller 101 switches the switching member 55 so that the nip pressure by the pressure mechanism 50 is reduced. <P>COPYRIGHT: (C)2012,JPO&INPIT |
