According to one embodiment, an image forming apparatus includes a process unit, a first rotator, a second rotator, a driving force transmission mechanism, and a displacement mechanism. The process unit forms an image. The first rotator is rotatable about a shaft in a first direction and a second direction reverse to the first direction. The second rotator is disposed in parallel to the first rotator. The second rotator is detachably connected to the process unit. The driving force transmission mechanism transmits a driving force of the first rotator to the second rotator to rotate the second rotator about a shaft when the first rotator is rotated in the first direction. The displacement mechanism releases the connection between the second rotator and the process unit by displacing the second rotator in a shaft direction when the first rotator is rotated in the second direction.

A guide structure includes a first guide member that guides a recording medium from a fixing unit to a transport roller unit, the fixing unit fixing an image formed on the recording medium to the recording medium by heating the recording medium that is transported, the transport roller unit transporting the recording medium; and a second guide member that comes into contact with the recording medium to which the image has been fixed by the fixing unit and guides the recording medium to the transport roller unit, the second guide member being disposed downstream of the first guide member in a transporting direction in which the recording medium is transported and being made of a material having a thermal conductivity higher than a thermal conductivity of a material of the first guide member.

An image forming apparatus has a sheet feed portion, a conveying portion, a control portion, a first sensor having the detection position at a first position in the sheet conveying passage, and a second sensor having the detection position at a second position downstream of the first position in the sheet conveying direction. The control portion performs first sensing to sense whether the sheet's rear end has passed the first position within a first time of the start of the feeding and second sensing to sense whether the sheet's rear end has passed the second position within a second time of the start of the feeding. Even if the control portion is unable to sense passage of the sheet's rear end in the first sensing, when it senses passage of the sheet's rear end in the second sensing, it makes the conveying portion continue feeding the sheet.

An image reading device includes a plurality of image reading units arranged at different positions in a width direction perpendicular to a conveyance direction of a recording medium to read an image on the recording medium at image reading positions and a conveyance roller pair that conveys the recording medium to the plurality of image reading units. The conveyance roller pair includes a drive roller and a driven roller that contacts the drive roller and rotates following the drive roller. The plurality of image reading units includes an upstream and a downstream image reading units downstream from the upstream image reading unit in the conveyance direction. A reading interval between the image reading positions and a diameter of the drive roller satisfy the relation:
X2=n1×π×D1a, where X2 represents the reading interval, n1 represents an integer, and D1a represents the diameter of the drive roller.

A drive mechanism that drives a rotator to rotate includes a main motor, an assist motor, and processing circuitry. The main motor drives the rotator. The assist motor drives the rotator and assists a drive of the rotator by the main motor. The processing circuitry controls a speed of the main motor so that a rotational speed of the rotator is constant, and controls a motor voltage of the assist motor so that the motor voltage of the assist motor changes according to a change in a motor current of the main motor.

An image forming apparatus includes a transfer unit configured to transfer second charged images superposed with one another onto a holding surface of a recording medium on which at least one first charged image has been electrostatically held and a static eliminating unit disposed upstream from the transfer unit in a transport direction of the recording medium and configured to remove static electricity from the recording medium electrostatically holding the at least one first charged image.

A recording medium conveyance device includes a conveyance device cover, a pair of guides, a maintenance part, a removable cover. The conveyance device cover is openable and covers a conveyance passage of a recording medium. The pair of guides forms the conveyance passage and includes a cover side guide on the conveyance device cover and a body side guide separable from the cover side guide. The maintenance part is on at least one of the pair of guides. The removable cover is configured to form a part of the conveyance passage and cover the maintenance part.

An image reading device includes a plurality of image reading units arranged at different positions in a width direction perpendicular to a conveyance direction of a recording medium to read an image on the recording medium at image reading positions and a conveyance roller pair that conveys the recording medium to the plurality of image reading units. The conveyance roller pair includes a drive roller and a driven roller that contacts the drive roller and rotates following the drive roller. The plurality of image reading units includes an upstream and a downstream image reading units downstream from the upstream image reading unit in the conveyance direction. A reading interval between the image reading positions and a diameter of the drive roller satisfy the relation:

X2=n1×π×D1a, where X2 represents the reading interval, n1 represents an integer, and D1a represents the diameter of the drive roller.

In an example, a conditioner module may include a bridge to receive media from a media path of an imaging device and to deliver the media to a media input of a finisher module. The conditioner module may include a calender nip disposed at an output end of the bridge. The calender nip may compress the media and may feed the media into the media input of the finisher module.

An image forming apparatus includes an image carrier, a toner supply unit, an application roller adjacent to the image carrier, a toner measuring unit, and a control unit. The toner supply unit supplies toner to the image carrier. The application roller applies a lubricant to the image carrier. The toner measuring unit measures an amount of toner transferred from the image carrier to the application roller. The control unit adjusts the supply of toner to be supplied to the image carrier in accordance with the amount of toner measured by the toner measuring unit.