Abstract: An image forming system includes: an image forming apparatus that includes a transfer device that transfers a toner image onto a sheet and a fixing device that fixes the toner image; a sheet heating device that heats the sheet on an upstream of the fixing device in a sheet conveyance direction; a first detector that detects a temperature inside the image forming apparatus; a second detector that detects a temperature of the sheet before the sheet heating device heats the sheet; and a controller that causes the sheet heating device to heat the sheet based on a detection result by the second detector and a sheet passing condition of the sheet, and corrects at least one of a transfer current and a transfer voltage in the transfer device based on a detection result by the first detector in a case where the sheet heating device heats the sheet.

Abstract: According to one embodiment, there is provided a temperature abnormality detection circuit provided in a temperature control device includes a target temperature determination circuit, a difference arithmetic circuit, a temperature abnormality determination circuit, and a storage circuit. The temperature abnormality detection circuit is configured to determine the presence or absence of temperature abnormality by a response situation of a detected temperature by a temperature sensor, calculate a current temperature difference from the detected temperature acquired by the temperature sensor if it is determined that there is a temperature abnormality and an estimated WAE temperature value, and determine whether the temperature sensor is abnormal or the control circuit side is abnormal based on the result of comparison between the temperature difference and a preset threshold value.

Abstract: An image forming apparatus includes a rotatable image bearing member and a rotatable developing member to carry developer made up of toner particles and carrier particles adhered to surfaces of the toner particles. Where a pressing force pressing the developing member against the image bearing member is F1, a total number of the carrier particles interposed between the toner particles and the image bearing member is N1, and an adhesion Ft between a carrier particle and a toner particle, measured when the carrier particle is pressed against the toner particle with F1/N1 that is a pressing force per unit carrier particle, and an adhesion Fdr1 between the carrier particle and the image bearing member, measured when the carrier particle is pressed against the image bearing member with F1/N1, satisfy Ft?Fdr1.

Abstract: A transfer belt, to be used in a state of being in contact with a cleaning member and an image carrier, and to which a developer image is to be transferred from the image carrier, includes a surface layer and a base layer. The surface layer is in contact with the image carrier and the cleaning member. The base layer disposed at a position more apart from the image carrier and the cleaning member than the surface layer. The surface layer is provided with grooves formed by transferring a predetermined mold shape and extending in a first direction along a moving direction of the transfer belt in an operating state. The arithmetic average roughness of the surface layer in a predetermined region is less than or equal to 0.2 ?m.

Abstract: An image forming apparatus includes an intermediate transfer member, first and second transfer members, and a control unit. The control unit includes a first state where both the first and second transfer members are separated from the intermediate transfer member, a second state where the first transfer member contacts the intermediate transfer member and the second transfer member is separated from the intermediate transfer member, and a third state where both the first and second transfer members contact the intermediate transfer member. The control unit controls the driving member to move the moving unit, controls switch the first state to the second state and thereafter switch the second state to the third state. A rotation speed of the driving member when the second state is switched to the third state is lower than a rotation speed of the driving member when the first state is switched to the second state.

Abstract: An image forming apparatus includes: an image bearing member that carries a developer image; a transfer member that forms a transfer nip portion with the image bearing member and transfers the developer image in the transfer nip portion from the image bearing member to a recording material; a fixing portion that includes a heater and fixes the developer image to the recording material using heat of the heater; a temperature detection portion that detects a temperature of the fixing portion; a control portion that controls power supplied to the heater such that the temperature detected by the temperature detection portion becomes a predetermined control target temperature; and an acquisition portion that acquires a temperature of the image bearing member or the transfer member. The control target temperature is changed based on the temperature acquired by the acquisition portion.

Abstract: A drum cartridge includes a frame on which a toner cartridge is attachable, a photosensitive drum, and a drum memory. The drum cartridge relays information stored in the toner memory to the image forming apparatus when the toner cartridge is attached to the frame.

Abstract: An image forming apparatus includes an image forming portion, a heating portion that includes a heating element which is heated by power from a power supply and heats an image, a temperature detecting portion that detects temperature of the heating portion, and a power control portion that controls power supplied to the heating element based on information from the temperature detecting portion. The image forming apparatus further includes a detecting portion that detects whether voltage from the power supply exceeds a rated value, and when the detecting portion detects that the voltage from the power supply exceeds the rated value, the power control portion controls the power supply such that a waveform pattern of an electric current to the heating element in one control cycle becomes a waveform pattern of phase control, where power supplying time to the heating element in one half wave becomes a predetermined time or less.

Abstract: There is used an image forming apparatus including a fixing unit configured to heat a recording material at a fixing nip portion to fix a toner image, and a control unit configured to switch a target temperature, wherein, in the case where the target temperature of preceding recording material is first temperature, the target temperature of subsequent recording material is second temperature which is higher than the first temperature, and a difference between the second temperature and the first temperature has a first value, the control unit performs switching from timing which is earlier than reaching of the second recording material to the fixing nip portion by a predetermined period, and, the higher the target temperature of the preceding recording material, the shorter the predetermined period.

Abstract: An image formation apparatus according to one or more embodiments may include: an apparatus main body that includes an image formation section configured to form an image on a medium; a fixation device that includes a fixation member configured to heat the medium and is attachable to the apparatus main body in a first direction; and a temperature detector including a lens, provided in the apparatus main body, and configured to detect a temperature of the fixation member through the lens. An optical axis of the lens is inclined with respect to the first direction.

Abstract: In an image forming apparatus, a controller causes a first fixing member to heat up to a standby temperature Tr lower than a fixing temperature, through a control process executed from a state in which rotation of the first fixing member is stopped and a nip pressure is set at a second pressure smaller than a first pressure. The control process includes: a first process of activating and controlling a heater to cause the first fixing member to heat up toward a target temperature; a second process of starting the rotation of the first fixing member; a third process of changing the nip pressure from the second pressure to the first pressure; a fourth process of changing the nip pressure from the first pressure to the second pressure; and a fifth process of stopping the rotation of the first fixing member, executed in this sequence.

Abstract: A fixing apparatus to fix a toner image formed on a recording material to the recording material includes a rotatable member having a heat generation layer, a power supply circuit, and a control unit. The power supply circuit supplies electrical power to the rotatable member. The control unit controls supply of electrical power to the rotatable member and detects a change rate of electrical resistance of the heat generation layer. The heat generation layer generates heat by the electrical power supplied to the rotatable member, and the toner image on the recording material is fixed to the recording material by the heat from the heat generation layer. If the change rate of the electrical resistance to the supplied electrical power is higher than a predetermined threshold, the control unit stops the supply of electrical power to the rotatable member.

Abstract: An image forming apparatus includes a fixing unit including a heater; a bidirectional thyristor for supplying electric power form an AC power source to the heater in a conduction state and for cutting off supply of the electric power from the AC power source to the heater in a non-conduction state; a control unit for outputting a control signal for controlling the conductive state or the non-conduction state of the bidirectional thyristor; and a DC voltage source for supplying electric power for conduction of the bidirectional thyristor by the control signal outputted from the control unit. The control unit controls the heater in a predetermined control cycle on a one half-wave unit basis of an AC voltage of the AC power source. The control unit outputs a plurality of control signals in one half-wave of the AC voltage.

Abstract: An image forming apparatus includes a belt, an image forming unit, a first roller configured to form a transfer portion where the toner image is transferred from the belt to a recording material, a second roller disposed upstream of the first roller, a pressing member disposed upstream of the first roller and downstream of the second roller, a guide member disposed upstream of the transfer portion, and a connecting member configured to electrically connect the guide member and the pressing member to each other.

Abstract: At least an electrode of a first electrode group and at least an electrode of a second electrode group are formed in a region nearer to one edge portion of a substrate than to a center of the substrate in a longer-side direction of the substrate, and the electrode that is nearest to the second electrode group in the longer-side direction among the first electrode group formed in the region nearer to the one edge portion and the second electrode group are provided with a space between the electrode and the second electrode group.

Abstract: A cleaning apparatus includes a plate shaped cleaner that comes into contact with a belt shaped member that rotates supported by a roller in a position not opposed to the roller in a surface on an opposite side of a surface where the roller comes into contact with the belt shaped member, wherein the plate shaped cleaner cleans the surface of the belt shaped member, and a hardware processor. The hardware processor obtains an amount of use of the plate shaped cleaner for each belt tension state in the belt shaped member in which the belt tension state is switched. The hardware processor sets a replacement determination timing of the plate shaped cleaner based on the obtained amount of use of the plate shaped cleaner.

Abstract: A capacitive voltage sensor assembly includes an electrode extending along a longitudinal axis, the electrode having a first end and a second end opposite the first end, and a tubular shield surrounding and spaced radially outward from a portion of the electrode. The tubular shield includes a plurality of through holes. The sensor assembly also includes a circular sensor element positioned radially inward of the tubular shield and including a first layer made of electrically conductive material and a second layer made of electrically insulating material. The circular sensor element includes a plurality of circumferentially spaced gaps.

Abstract: An image forming apparatus includes a fixing unit including a tubular film, a pressure roller, and a heater including a heating element. The apparatus further includes a control unit configured to calculate an accumulated electrical energy supplied to a portion of the heating element. The portion of the heating element is located in an area corresponding to a second area of the nip portion. The second area is an area of the nip portion through which the recording material conveyed to the nip portion is not passed. The control unit is configured to determine an operation of heat leveling, which is performed for leveling a heat distribution in the nip portion after the recording material had passed the nip portion, based on the calculated accumulated electrical energy.

Abstract: A heating device for heating a medium on which an image can be formed includes a cylindrical belt, a first heating unit, and a second heating unit. The first and second heating units are inside the cylindrical belt and face an inner circumferential surface of the belt. A controller is configured to control the heating units to generate heat. When the medium is to be heated to reach an image fixing temperature at which the image can be fixed to the medium, the controller controls the first and second heating units to both generate heat. After the medium is heated to the image fixing temperature, the controllers control the first heating unit to generate heat, but not the second heating unit.

Abstract: A position sensor includes a detector and a signal processor. The detector includes: a sensor chip having a surface; a first detection element disposed at the surface of the sensor chip; and a second detection element disposed at the surface of the sensor chip. The signal processor processes a signal input from the detector. The first detection element outputs a first detection signal corresponding to a position of a detection target, based on a change in a magnetic field received from the detection target. The second detection element outputs a second detection signal corresponding to the position of the detection target, based on the change in the magnetic field received from the detection target. A center of balance of the first detection element coincides with a center of balance of the second detection element.