An image forming apparatus includes an image forming device that forms an image on a recording medium and circuitry that controls the image forming device. The image forming device forms an invisible image with an invisible material on the recording medium and forms a visible image with a visible material on the invisible image. Each of first and second adhesion amounts includes respective adhesion amounts of the visible material and the invisible material per unit area in a portion, in which the visible image is formed on the invisible image, of the composite image. The second adhesion amount is smaller than the first adhesion amount. The controller adjusts the amount of the invisible material included in the second adhesion amount to be smaller than that included in the first adhesion amount, to cause the image forming device to form the image according to the second adhesion amount.

An image forming apparatus includes an image forming device, a body, an intermediate transfer unit, a cover, and a guide rail. The body has a bottle housing hole in which a toner bottle is removably inserted. The intermediate transfer unit includes an intermediate transfer belt and a plurality of rollers to drive the intermediate transfer belt and is removably disposed between the image forming device and the bottle housing hole. The intermediate transfer unit and the toner bottle are accessible from a front side of the body. The openable and closable cover is disposed at an inlet-and-outlet port of the bottle housing hole. The guide rail is disposed at a lower side of the bottle housing hole to slidably guide the intermediate transfer unit and has a front-side end extended to a position crossing at least a vertical projection line of the cover on the front side of the body.

A sheet characteristic detection device includes: a detector that is disposed on a sheet ejection path through which a sheet is ejected and that detects an electrical resistance value of the sheet; and a charge neutralizer that is disposed on a downstream side of the detector on the sheet ejection path and that neutralizes electric charge on the sheet.

An image forming apparatus includes an apparatus body, and an opening/closing cover configured to expose an opening portion of the apparatus body by being opened. The apparatus body includes a main body frame, a plurality of conveyance units being detachably attached to the main body frame through the opening portion, a control board configured to control the plurality of conveyance units, and a relay board configured to be electrically connected to the control board. The plurality of conveyance units respectively include a plurality of first connectors. The relay board includes a plurality of second connectors that are arranged to face the opening portion and that are configured to be connected to the plurality of first connectors, the relay board being arranged at a position not interfering with attachment/detachment loci in which the plurality of conveyance units are attached to and detached from the main body frame.

An image forming apparatus includes an apparatus body, and an opening/closing cover configured to expose an opening portion of the apparatus body by being opened. The apparatus body includes a main body frame, a plurality of conveyance units being detachably attached to the main body frame through the opening portion, a control board configured to control the plurality of conveyance units, and a relay board configured to be electrically connected to the control board. The plurality of conveyance units respectively include a plurality of first connectors. The relay board includes a plurality of second connectors that are arranged to face the opening portion and that are configured to be connected to the plurality of first connectors, the relay board being arranged at a position not interfering with attachment/detachment loci in which the plurality of conveyance units are attached to and detached from the main body frame.

A metal frame provides a ground potential. An image forming unit forms a toner image on a sheet. A fixing apparatus fixes the toner image on the sheet. The fixing apparatus comprises a heating element for generating heat by being supplied with power from an alternating current power source. An insulating layer covers the heating element. A conductive layer contacts the insulating layer and insulated from the metal frame. A tube-shaped member is heated by the heating element. A pressing member is arranged opposing the tube-shaped member and forms a nip portion in cooperation with the tube-shaped member. A capacitive element whose one end is connected to the metal frame and whose other end is connected to the conductive layer of the fixing apparatus.

Each of four outer side surfaces of each of a plurality of square pipes include a groove portion formed along a longitudinal direction of each of the plurality of square pipes and a pair of ridge line portions forming edge portions on both sides of the groove portion. An additional member includes a contact plane which is a plane in contact with a portion of the plurality of square pipes. The additional member is fixed to a plurality of first target pipes which are some of the plurality of square pipes with the contact plane in contact with at least one of the pair of ridge line portions, or the additional member is fixed to a second target pipe which is one of the plurality of square pipes with the contact plane in contact with the pair of ridge line portions.

An image forming system includes an image forming apparatus and a feeding device, the image forming apparatus including an image forming unit, a housing, an opening/closing door openable and closable between a first closed position and a first open position, and a support unit openable and closable between a second closed position and a second open position and configured to support a sheet when the support unit is at the second open position, the feeding device being movable in a direction horizontal to the image forming apparatus, configured to move to a coupled position and a decoupled position and feed the sheet to the image forming apparatus when the feeding device is at the coupled position, wherein when the feeding device is at the decoupled position and the opening/closing door is at the first open position, the feeding device overlaps the support unit as viewed from a first direction.

A metal frame provides a ground potential. An image forming unit forms a toner image on a sheet. A fixing apparatus fixes the toner image on the sheet. The fixing apparatus comprises a heating element for generating heat by being supplied with power from an alternating current power source. An insulating layer covers the heating element. A conductive layer contacts the insulating layer and insulated from the metal frame. A tube-shaped member is heated by the heating element. A pressing member is arranged opposing the tube-shaped member and forms a nip portion in cooperation with the tube-shaped member. A capacitive element whose one end is connected to the metal frame and whose other end is connected to the conductive layer of the fixing apparatus.

A sheet feeding apparatus includes a sheet support unit, a feed unit, and an extension support unit. The inserted portion includes an opening portion that is larger than the insertion portion when viewed in the first direction and into which the insertion portion is inserted in the attached state, an engaged portion configured to engage and disengage with respect to the engagement portion in a second direction intersecting with the first direction and configured to position the extension support unit with respect to the sheet support unit in the first direction by engaging with the engagement portion in the attached state, a contacted portion configured to come into contact with the contact portion in a third direction intersecting with the first direction and the second direction, and an urging portion configured to urge the contact portion toward the contacted portion in the third direction.