Abstract: The present invention provides an image forming apparatus including an upstream conveying portion, a downstream conveying portion, and a loop detector, wherein the image forming apparatus further includes a driving portion which moves the contact portion to a projecting position where the sheet conveying path is in contact with a conveyed sheet and to a retracted position where the sheet conveying path is not in contact with the conveyed sheet, and a controlling portion which controls the driving portion such that the contact portion is moved from the projecting position to the retracted position before a tip end of a sheet which enters the sheet conveying path from the upstream conveying portion reaches the contact portion.

Abstract: The image forming apparatus includes an image forming portion forming a toner image on a recording material, and a fixing portion heating and fixing the toner image formed on the recording material to the recording material, wherein the apparatus has a cleaning mode in which the fixing portion is cleaned, and when the cleaning mode is set, the image forming portion forms a predetermined toner image on the recording material, and the fixing portion then heats and fixes the predetermined toner image to the recording material to form a cleaning sheet which is heated and conveyed to clean the fixing portion. By the virtue of the present invention, it achieves high cleaning performance in which the fixing portion is cleaned by the cleaning sheet.

Abstract: The image forming apparatus includes a fixing portion, a temperature detection element, and a power control portion, wherein the power control portion is capable of setting a first power supply control mode for supplying power according to the detected temperature for each one control cycle, a second power supply control mode for supplying power according to the detected temperature for each one control cycle and a third power supply control mode for supplying predetermined power, and switches, immediately before a leading edge of the recording material enters the fixing portion, a state of supplying the power in the first power supply control mode to a state of supplying the power in the second power supply control mode, and then switches the state of supplying the power in the second power supply control mode to a state of supplying the power in the third power supply control mode.

Abstract: The image forming apparatus includes an image forming portion forming a toner image on a recording material, and a fixing portion heating and fixing the toner image formed on the recording material to the recording material, wherein the apparatus has a cleaning mode in which the fixing portion is cleaned, and when the cleaning mode is set, the image forming portion forms a predetermined toner image on the recording material, and the fixing portion then heats and fixes the predetermined toner image to the recording material to form a cleaning sheet which is heated and conveyed to clean the fixing portion. By the virtue of the present invention, it achieves high cleaning performance in which the fixing portion is cleaned by the cleaning sheet.

Abstract: The image forming apparatus, in the case where image forming is performed on a recording medium whose size covers a position of a second temperature detection element perpendicularly disposed to the recording medium conveyance direction, when the detected temperature rises to a predetermined temperature during execution of the first power supply control, a first power supply control is switched to a second power supply control. In the case where image forming is performed on a recording medium whose size does not cover a position of the second temperature detection element, when the detected temperature rises to a predetermined temperature during execution of the first power supply control, a conveyance control portion executes a control for extending the conveyance interval of the recording medium. Thus, an unduly large temperature rise in the non-sheet passing portion is prevented, and a good quality image can be provided without glossy unevenness in one sheet.