An image forming apparatus includes an image forming unit to form an image on a sheet. A fixing device heats the sheet and includes a tubular body that presses against the sheet and rotates, and a heat generator contacts an inside surface of the tubular body. The length dimension of the heat generator is aligned with the axial direction of the tubular body. The heat generator has a first row of first heating elements with a first gap between each adjacent pair of first heating elements and a second row of second heating elements. The first and second rows are offset from one another in a width direction corresponding to the sheet conveyance direction. A second gap is between each adjacent pair of second heating elements in the longitudinal direction. The positions of the first gaps are different from positions of the second gaps.

A photo finisher includes a heating roller, a pressing roller, a belt, a supporting roller and a duct. The heating roller is to generate heat. The pressing roller is pressed against the heating roller to form a heating nip. The belt is supported by the supporting roller and the heating roller to pass through the heating nip, and the belt is extending to a downstream side of the heating nip. The duct is positioned apart from the belt, the duct includes a first end in the width direction being provided with an air inlet port and a second end, opposite to the first end, being blocked, and the duct includes an air discharge port opening towards the belt.

A fixing unit includes a tubular film, a pressure roller, a heater including a first heating element and a second heating element, a detector configured to detect a temperature of the heater, a switcher configured to switch which of the first heating element and the second heating element is supplied power from a power supply, and a controller configured to control the switcher. The controller is configured to execute a first control of determining a first electric energy and a second electric energy based on the temperature of the heater detected by the detector and a target temperature of the heater, and a second control of causing the switcher to switch between a state in which power is supplied to the first heating element by the first electric energy and a state in which power is supplied to the second heating element by the second electric energy.

A fuser having a heater, a holder, and a connector, is provided. The heater is in a form of a planar plate. The heater has a metal-made base plate having a recessed portion, a heating pattern having a resistance-heating element arranged on the base plate, and a plurality of power-supplying terminals conductive to the heating pattern. The plurality of power-supplying terminals are located in an end area in the heater on one side in a lengthwise direction of the heater. The holder supports the heater and has a projecting portion configured to contact the recessed portion in the lengthwise direction. The connector has electrodes connectable with the plurality of power-supplying terminals. The recessed portion is located between the heating pattern and one of the plurality of power-supplying terminals closest to the heating pattern in the lengthwise direction.

A heating device includes a first temperature sensor and a second temperature sensor that detect a temperature of at least one of a first rotator, a second rotator, and a heater that heats at least one of the first rotator and the second rotator. The first temperature sensor is disposed outboard from an increased conveyance span where an increased size sheet having an increased width in a longitudinal direction of the heater is conveyed. The second temperature sensor is disposed outboard from a decreased conveyance span where a decreased size sheet having a decreased width in the longitudinal direction of the heater is conveyed. The decreased conveyance span is smaller than the increased conveyance span. The second temperature sensor is disposed within the increased conveyance span and disposed opposite the first temperature sensor via a center of the increased conveyance span in the longitudinal direction of the heater.

An electrothermal heating device for heating a print medium includes an endless belt, a first electrode and a second electrode. The endless belt rotates in a rotational direction about a rotation axis that defines an axial direction, so as to generate heat when the endless belt rotates and is supplied with power. The endless belt includes a base portion made of a nanocomposite material having a carbon filler. The first and second electrodes are in contact with the base portion of the endless belt. The first and second electrodes extend in the axial direction of the endless belt, and are spaced apart in the rotational direction of the endless belt. A volume resistivity of the base portion of the endless belt in the rotational direction is less than a volume resistivity of the base portion in the axial direction.

A fixing device includes a movable belt; and a planar heat-generating section that is in contact with the belt and in which, among plural heat-generating portions provided in a movement direction of the belt, a heat-generating portion on an upstream side in the movement direction of the belt has a larger heat generation amount than a heat-generating portion on a downstream side.

A fixing device includes a fixing belt that is endless and rotatable. A nip formation pad is disposed opposite an inner circumferential face of the fixing belt via a lubricant. A pressure roller sandwiches the fixing belt together with the nip formation pad to form a pressing region through which a recording medium is conveyed. A cap is disposed opposite a lateral end of the fixing belt in an axial direction of the fixing belt. A seal is tubular and contacts an outer circumferential face of the fixing belt in at least a part of an inner circumferential face of the seal. The seal seals a gap between the cap and the fixing belt. The seal includes a non-perpendicular portion that is not perpendicular to a circumferential direction of the fixing belt and defines a slit.

A fixing device includes a first rotator, a second rotator, a heater, a conductor, and a discharger. The first rotator includes a conductive first layer, a non-conductive second layer, and a conductive third layer. The first to third layers exist in an order of the first layer to the third layer from a center of the first rotator to an outside of the first rotator. The second rotator forms a nip between the first rotator and the second rotator. A recording medium bearing a toner image passes through the nip. The heater is disposed inside a loop of the second rotator and heats the second rotator. The conductor is in contact with one of the first layer and the third layer. The discharger is in contact with the conductor and the other one of the first layer and the third layer and removes electric charge from the first rotator.

An image forming apparatus includes an image forming unit, a fixing unit, a heating portion and a removal unit to remove a particulate dust generated due to vaporization of a parting agent by heat in the fixing unit. The removal unit includes a sheet-like filter provided with a base layer and a collecting layer laminated on the base layer for collecting dust. The removal unit includes a holding unit to hold the filter in a cylindrical shape with the base layer outside and the collecting layer inside. The removal unit includes a fan connected to one of opening end sides of the filter held in the cylindrical shape and generates an air flow inside of the cylindrical shape which causes air passing from outside of the filter to inside to flow toward the one of the opening end sides.