Patent ID: 8634751

Claim:
An image forming apparatus comprising: a transfer nip configured to transfer a toner image to a sheet conveyed at a transfer speed; a first conveyance belt configured to convey the sheet to which the toner image is transferred at the transfer nip; a second conveyance belt provided downstream of the first conveyance belt in a conveyance direction in which the sheet is conveyed and configured to convey the sheet; a fixing nip provided downstream of the second conveyance belt in the conveyance direction and configured to fix the toner image to the sheet while conveying the sheet; a fixing drive unit configured to drive the fixing nip so that the fixing nip conveys the sheet at a speed that is higher than the transfer speed in a high speed fixing mode in which the fixing nip fixes the toner image to the sheet while conveying the sheet at the speed that is higher than the transfer speed; and a control unit configured to perform control so that a circumferential speed of the second conveyance belt is changed from a first speed at which the sheet advances from the transfer nip to a second speed at which a leading edge of the sheet enters the fixing nip and which is higher than the first speed after a trailing edge of the sheet, conveyed by the first conveyance belt whose circumferential speed is set to the first speed and the second conveyance belt whose circumferential speed is set to the first speed, passes the transfer nip and before the leading edge of the sheet reaches the fixing nip in the high speed fixing mode and in response to a length of the conveyed sheet in the conveyance direction being longer than a length from the transfer nip to an upstream end of the second conveyance belt, wherein, after the circumferential speed of the second conveyance belt is changed to the second speed, the sheet sucked against the second conveyance belt is conveyed by the second conveyance belt while sliding on the first conveyance belt.