A first temperature detecting member is arranged in a longitudinal direction of a heater at a position that is (i) in a vicinity of an end adjacent to a second heating element among ends in the longitudinal direction of a first heating element, and (ii) separated from a reference passing position with respect to a recording material end that passes near a boundary between the first heating element and the second heating element by at least 2.5 mm toward a side close to a transport reference position, and a second temperature detecting member is arranged in the longitudinal direction at a position that is (iii) in a vicinity of an end adjacent to the first heating element among ends in the longitudinal direction of the second heating element, and (iv) separated from the reference passing position by at least 2.5 mm toward a side far from the transport reference position.

Provided is an image forming apparatus and a control program. A fixer includes a first roller which includes an elastic layer having a predetermined thickness in a surface, a second roller which includes an elastic layer having a thickness smaller than that of the first roller in a surface, a fixing belt which is laid across the first roller and forms a fixing nip portion between the second roller and the fixing belt, and first and second drive motors that drive the first and second rollers, respectively. A hardware processor controls a drive current of the first drive motor so that an electromotive current generated in the second drive motor has a predetermined value in a case where the first roller is rotatively driven by the first drive motor and the second roller is caused to rotate as a follower of the first roller and the fixing belt.

In an image forming device, a first fixing member has a roller. A second fixing member has a belt to form a nip together with the first fixing member. A pressure modifying mechanism modifies a nip pressure at the nip to selected one of a first nip pressure and a second nip pressure smaller than the first nip pressure. A controller drives the first motor to drive the roller and fixes the developer image on a sheet in a state that the nip pressure is the first nip pressure. The controller modifies the nip pressure from the first nip pressure to the second nip pressure while driving the first motor in a case where a final sheet among one or more sheets fixed according to a print job has passed the nip, and halts the first motor after the nip pressure is modified to the second nip pressure.

According to one embodiment, a temperature control device includes a temperature estimation unit and a frequency generation unit. The temperature estimation unit is configured to estimate a temperature of an object being heated by an induction heating coil, the temperature being estimated based on a frequency of a drive signal supplied to an inverter connected to the induction heating coil. The frequency generation unit is configured to set the frequency of the drive signal based on the temperature estimated by the temperature estimation unit, a detected temperature of the object from a temperature sensor, and a target temperature for the object.

Provided is an image forming apparatus and a control program. A fixer includes a first roller which includes an elastic layer having a predetermined thickness in a surface, a second roller which includes an elastic layer having a thickness smaller than that of the first roller in a surface, a fixing belt which is laid across the first roller and forms a fixing nip portion between the second roller and the fixing belt, and first and second drive motors that drive the first and second rollers, respectively. A hardware processor controls a drive current of the first drive motor so that an electromotive current generated in the second drive motor has a predetermined value in a case where the first roller is rotatively driven by the first drive motor and the second roller is caused to rotate as a follower of the first roller and the fixing belt.

An image forming apparatus includes an image fixing unit to pass a sheet carrying an unfixed toner image on a first side. The image fixing unit includes: a first fixing section adjacent to the first side of the sheet; a first heating section to heat the first fixing section; a second fixing section adjacent to a second side opposite to the first side of the sheet; and a second heating section to heat the second fixing section. The image forming apparatus further includes: sheet feeding trays holding sheets; a storage unit storing fixing temperatures of the fixing sections preset for each type of the sheets in the sheet feeding trays; and a controller to select standby temperatures from the fixing temperatures, based on temperature profiles of the fixing sections, and to instruct the heating sections to respectively maintain the fixing sections at the selected standby temperatures during a standby mode.

A fixing device includes a heating body, a pressuring body, a heating source, a guiding part, a temperature sensing part and a charging part. The heating source supplies the heating body heat used for heating the medium. The guiding part guides the medium to a nip between the heating body and the pressuring body, at an upstream side from the nip in a conveying direction of the medium. The temperature sensing part senses a temperature of the heating body. The charging part electrically discharges to electrically charge the heating body with the same polarity as toner, at an opposite side to the guiding part across the temperature sensing part. The charging part includes a discharging electrode electrically discharging toward the heating body facing to the discharging electrode and an enclosure wall supporting the discharging electrode, enclosing the discharging electrode and producing an electric field in cooperation with the discharging electrode.

A fixing device includes a first pressure structure, a second pressure structure, a fixing member, a first arm, a second arm, and an elastic member. The fixing member is disposed between the first and second pressure structures. The first arm is pivotable about a first shaft and includes a first pressing portion and a first connection portion. The second arm is pivotable about a second shaft and includes a second pressing portion and a second connection portion. The elastic member biases the first and second pressing portions toward each other. A first leverage ratio of a distance between the first shaft and the first connection portion to a distance between the first shaft and the first pressing portion is different from a second leverage ratio of a distance between the second shaft and the second connection portion to a distance between the second shaft and the second pressing portion.

A pressure-bonding device that pressure-bonds pressure-bondable toner surfaces to each other which are surfaces of a printing medium on which pressure-bondable toners are formed includes: a pair of rollers that applies a pressure to pressure-bondable surfaces, on which the pressure-bondable toner surfaces of the printing medium face each other, by sandwiching the printing medium in a nip portion; and a heating control mechanism that heats the nip portion.

A fixing device includes a first pressure structure, a second pressure structure, a fixing member, a first arm, a second arm, and an elastic member. The fixing member is disposed between the first and second pressure structures. The first arm is pivotable about a first shaft and includes a first pressing portion and a first connection portion. The second arm is pivotable about a second shaft and includes a second pressing portion and a second connection portion. The elastic member biases the first and second pressing portions toward each other. A first leverage ratio of a distance between the first shaft and the first connection portion to a distance between the first shaft and the first pressing portion is different from a second leverage ratio of a distance between the second shaft and the second connection portion to a distance between the second shaft and the second pressing portion.