Abstract: A fuser for thermally fixing a toner image on a recording medium includes: an endless fusing belt configured to transfer heat to the toner image; a heat source configured to heat the fusing belt; a detection unit configured to detect peripheral inward deformation of the fusing belt; and a power cut-off unit configured to cut off power supplied to the heat source upon detection of the peripheral inward deformation of the fusing belt by the detection unit.

Abstract: An image forming apparatus includes an image forming section, a heat source, a fixing rotating body, a pressurizing rotating body, a feeding section for feeding a medium, a temperature adjusting section for controlling an amount of heat generated by the heat source, and a control section. The control section switches between a first mode in which the fixing rotating body and the pressurizing rotating body rotate at a first circumferential speed and the medium is fed to the image forming section at a first distance interval, and a second mode in which the fixing rotating body and the pressurizing rotating body rotate at a second circumferential speed higher than the first circumferential speed and the medium is fed to the image forming section at a second distance interval longer than the first distance interval.

Abstract: An image forming apparatus includes an image forming section, a heat source, a fixing rotating body, a pressurizing rotating body, a feeding section for feeding a medium, a temperature adjusting section for controlling an amount of heat generated by the heat source, and a control section. The control section switches between a first mode in which the fixing rotating body and the pressurizing rotating body rotate at a first circumferential speed and the medium is fed to the image forming section at a first distance interval, and a second mode in which the fixing rotating body and the pressurizing rotating body rotate at a second circumferential speed higher than the first circumferential speed and the medium is fed to the image forming section at a second distance interval longer than the first distance interval.

Abstract: The present invention reduces delay in supplying heat to fixing nip when sheet passes therethrough and overcomes disadvantages like uneven gloss in page and fixing faults by including temperature detector 83 detecting temperatures of fixing member including heat application roller and fixing belt, leading end detector 85 detecting timing leading end of sheet passes through predetermined position upstream in conveyance path from fixing position by distance portion of fixing belt having been in position heated by heat application part 81 travels to fixing position, and temperature controller 87 performing normal temperature control being on-off control of heat application part 81 based on detected temperature until sheet passes through, keeping heat application part 81 on until detected temperature reaches switching temperature if it exceeds switching temperature and heat application part 81 is off before detection when the sheet passes through and resuming normal temperature control when it reaches predetermin