An image forming apparatus includes: a toner image forming section; a transfer section; a fixing section; a conveyance roller section disposed on a downstream side of the fixing section in a sheet conveyance direction; a conveyance guide section disposed on a downstream side of the conveyance roller section and including a first guide member disposed on a fixing side of a sheet and a second guide member disposed on a rear surface side of the sheet; a feeding-path-switching section disposed on a downstream side of the conveyance guide section and configured to switch sheet feeding paths; and a nip angle adjusting section configured to change a nip angle of a conveyance nip in accordance with whether a sheet on which an image is formed on a first surface thereof is conveyed, or a sheet on which an image is formed on a second surface thereof is conveyed.

The electro-photographic sheet of paper duplex printing machine includes a sheet supply section, a sheet positioning section which positions sheets and sends out sheets to a backup roller in an electro-photographic printing section, the electro-photographic printing section transfers an image which has been transferred onto the transfer roller onto the sheet, a chain delivery section, a delivery section and a sheet carrying section for turnover. The chain delivery section selectively transfers printed sheets, which has been transferred from the backup roller to the delivery section or sheet carrying section for turnover. The sheet carrying section for turnover supplies one side printed sheet to the sheet positioning section. The sheet fed from the sheet supply section and one side printed sheet fed from the sheet carrying section for turnover are alternately carried to the sheet positioning section and the toner image on the printed sheet is fixed by the fixing device.

An image formation system includes a cooling section that cools a sheet in a period after a toner image is fixed on a first surface by a first fixing section and before the toner image is formed on a second surface of the sheet by a second image forming apparatus, and a hardware processor that controls a cooling operation of the cooling section in accordance with a parameter representing a temperature of an image forming section of the second image forming apparatus.

This image forming device includes an image former, a fuser, a sheet transport path that transports a paper sheet to the image former and the fuser, first and second discharge ports that are connected to the sheet transport path so as to enable a paper sheet on which a toner image has been fused to be discharged to the outside, and a controller. The sheet transport path includes first to third transport paths, and a first and second switcher. The controller, in the case of duplex printing, controls the first and second switchers such that a one end side of the paper sheet is transported to the second discharge port, and controls the second switcher such that, when the one end side is being discharged from the second discharge port, reverses the paper sheet and causes the another end side to be transported toward the image former.

A transmission unit transmits driving force to be supplied from a motor to a roller pair. A switching unit acts on the transmission unit to switch a rotation direction of the roller pair by the driving force between a normal rotation and a reverse rotation. A control unit controls a rotation speed of the motor to convey the sheet at a second conveyance speed in a part of a first time period. The second conveyance speed is lower than a first conveyance speed. The first conveyance speed is a conveyance speed when the sheet is conveyed in the image forming unit. In the first time period the sheet having the image formed on the first surface is conveyed in a first direction. In a second time period the sheet is conveyed in a second direction.

An example image forming apparatus includes, a main body, a first fixing device disposed in the main body to primarily fix a toner image transferred on a printing medium while passing through a transfer device, a first discharge device to discharge the printing medium having passed through the first fixing device from the main body, and a second fixing device disposed in the main body to additionally fix the toner image on the printing medium having passed through the first fixing device, wherein the second fixing device may be supplied with the printing medium through a connection path returning from the first discharge device into the main body and connected to the second fixing device.

An image forming apparatus includes an image bearing member, a transfer device, a voltage applying portion, a fixing device, and a controller. During execution of an operation in an output mode, the controller is capable of selectively executing: an operation in which test images formed on a first side of a first recording material are fixed and then the first recording material is outputted without forming the test images on a second side of the first recording material and then in which a second recording material is passed through the fixing device without forming the test images on a first side of the second recording material and then the test images are transferred onto a second side of the second recording material.

An example image forming apparatus includes a simplex path for conveying printing medium passing through a fixing unit provided in a main body to a discharge port of the main body, a duplex path for turning over printing medium and conveying the printing medium to the simplex path, and a discharge unit for selectively conveying a first printing medium and a second printing medium in different directions, wherein the first printing medium includes an image formed on one surface passing through the simplex path, and the second printing medium includes an image formed on two surfaces and passing through the simplex path after passing through the duplex path.

An image forming apparatus sets, in a case where a mode for executing a heating process a plurality of times is set, a target temperature of a fixing unit during a second heating process depending on image information about a toner image to be formed on a first surface of a recording medium immediately before a first heating process.

A transmission unit transmits driving force to be supplied from a motor to a roller pair. A switching unit acts on the transmission unit to switch a rotation direction of the roller pair by the driving force between a normal rotation and a reverse rotation. A control unit controls a rotation speed of the motor to convey the sheet at a second conveyance speed in a part of a first time period. The second conveyance speed is lower than a first conveyance speed. The first conveyance speed is a conveyance speed when the sheet is conveyed in the image forming unit. In the first time period the sheet having the image formed on the first surface is conveyed in a first direction. In a second time period the sheet is conveyed in a second direction.