An image forming apparatus has a feed tray, a transferring unit, a fixing unit, a output tray, a conveying unit for conveying a sheet along a sheet conveyance path including a first sheet conveyance path and a second sheet conveyance path which branches from the first sheet conveyance path on a downstream side and joins to the first sheet conveyance path on a upstream side, and a controller. The controller causes the conveying unit to convey sheets, calculates a specific amount related to the amount of toner per unit area of a page in image data, performs double-sided printing with the large number of sheets conveyed in a case where the specific amount is smaller than a predetermined amount, and performs double-sided printing with the small number of sheets conveyed in a case where the specific amount is equal to or larger than the predetermined amount.

According to one embodiment, the temperature control device is a temperature control device for controlling temperature of a temperature controlled target to which heat is propagated from a heater by supplying power to the heater, the device including: a temperature estimation unit; a duty generation unit; and a signal generation unit. The temperature estimation unit estimates the temperature of the temperature controlled target based on the duty value. The duty generation unit generates the duty value based on the temperature estimation result by the temperature estimation unit, the temperature detection result of the temperature controlled target by the temperature sensor, and the target temperature. The signal generation unit outputs an energization pulse for controlling the power supplied to the heater based on the duty value.

A roller member includes a rotating shaft and a roller portion. The roller portion includes a first layer provided on at least a portion of an outer peripheral surface of the rotating shaft, and a second elastic layer provided on at least a portion of an outer peripheral surface of the first layer. The first layer is made of a material having a coefficient of linear expansion lower than a coefficient of linear expansion of a material of the second elastic layer.

A manufacturing method for a silicone rubber molded body that is to be used in an electrophotographic image forming apparatus includes a heating process of a precursor of a silicone rubber molded body. The heating process includes heating the precursor of a silicone rubber molded body and externally introducing an environmental gas and discharging the environmental gas to outside, to reduce an amount of a low molecular weight compound remaining in the precursor of a silicone rubber molded body.

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.

An image forming apparatus includes: a conveying portion configured to convey a continuous recording medium in a first conveying direction or in a second conveying direction opposite to the first conveying direction; an image forming portion configured to form a toner image on the continuous recording medium at a transfer nip; a fixing portion provided on a lower stream side of the image forming portion in the first conveying direction and configured to heat and fix the toner image formed on the continuous recording medium, at a fixing nip; a retaining portion provided between the transfer nip and the fixing nip in the first conveying direction and configured to retain a part of the continuous recording medium; and a control portion configured to control the conveying portion to convey a passed portion that has passed through the fixing nip and control the retaining portion to retain the passed portion.

An apparatus includes a first and second driving circuits that energize a first and third heat generating blocks; a first and second temperature detection members that detect each temperature of the first and third heat generating blocks; a control portion that controls the first and second driving circuits according to at least one of the temperatures detected by the first and second temperature detection members; and a connection switching portion that selectively connects any one of the first and second driving circuits to a second heat generating block according to a switching instruction from the control portion. The control portion controls energization of the second heat generating block together with a heat generating block which is energized by the driving circuit connected to the second heat generating block.

A fixing apparatus fixes an image onto a recording material. A first fuse and a second fuse are connected in series each other. A power supply line is connected to one end of the first fuse. A signal line is connected to a connection point between another end of the first fuse and one end of the second fuse. A ground line is connected to another end of the second fuse. Information regarding the fixing apparatus is held in accordance with melt states of the first and second fuses.

In an image forming device, a device body has an opening. A process member forms a developer image on a sheet. The fixing device fixes the developer image on the sheet. A fixing device is removable from the device body through the opening. A process-power supply member supplies process-power to the process member based on power inputted from a power supply member. A switch switchable between: a first state in which the switch allows connection between the process-power supply member and the power supply member; and a second state in which the switch disconnects the process-power supply member from the power supply member to interrupt input of the process-power to the process-power supply member. The switch switches to the first state when the fixing device is mounted in the device body. The switch switches to the second state when the fixing device is removed from the device body.

An image forming apparatus includes an image forming unit that forms a first image and a second image and transfers the first and second images to a recording medium, the first image including a metallic color image, the second image not including the metallic color image; and a fixing unit that fixes the first image and the second image to the recording medium. The image forming apparatus has a mode in which, when forming the first image on only one of a first surface and a second surface of the recording medium, the image forming unit transfers the first image to the first surface of the recording medium and the fixing unit fixes the first image to the first surface, and subsequently the image forming unit transfers the second image to the second surface of the recording medium and the fixing unit fixes the second image to the second surface.