Abstract: An image forming apparatus includes an image forming device to form a cleaning toner image in a cleaning region on a cleaning sheet and a check toner image in a check region on the cleaning sheet. The image forming apparatus further includes a fixing device including a first rotator and a heater to heat the first rotator to a cleaning temperature that is lower than a fixing temperature to which the first rotator is heated in a print job and higher than a cold offset temperature at which toner adheres to the first rotator by cold offset. Each of the cleaning region and the check region has a length greater than a circumferential length of the first rotator. The cleaning region and the check region are disposed at a leading section and a trailing section of the cleaning sheet in a cleaning sheet conveyance direction, respectively.

Abstract: A fixing device includes a rotatable fuser member a heater, a rotatable pressure member, a thermometer, and a feedback controller. The rotatable fuser member is subjected to heating. The heater heats the fuser member to a heating temperature. The rotatable pressure member is disposed opposite the fuser member. The fuser member and the pressure member are pressed against each other to form a fixing nip therebetween, through which the recording medium is conveyed, so as to fix the toner image in place under heat and pressure. The thermometer is disposed adjacent to the pressure member to detect an operational temperature of the pressure member. The feedback controller is operatively connected with the thermometer to control the heating temperature according to the detected operational temperature, so that the recording medium exhibits a substantially constant post-fixing temperature downstream from the fixing nip regardless of the heat capacity of the recording medium.

Abstract: A fixing device includes a fixing rotator formed into a loop and rotatable in a predetermined direction of rotation and a pressure rotator disposed outside the loop formed by the fixing rotator and pressed against the fixing rotator to form a fixing nip therebetween through which a recording medium bearing a toner image is conveyed. A stay is disposed opposite the pressure rotator via the fixing rotator. A heater is disposed opposite an inner circumferential surface of the fixing rotator to heat the fixing rotator. A pressurization member is pressed against the heater via the fixing rotator. A housing is interposed between the stay and the heater. A temperature detector is mounted on the housing to detect a temperature of the heater.

Abstract: An image forming apparatus includes a controller including a primary heating control portion to control a heater to perform a primary heating to heat a fixing rotator with a first amount of power determined based on a temperature of the fixing rotator, a secondary heating control portion to control the heater to perform a secondary heating to heat the fixing rotator with a preset second amount of power, and a switch portion to control the heater to switch between the primary heating and the secondary heating during an identical print job and to perform at least one of a primary switching from the primary heating to the secondary heating and a secondary switching from the secondary heating to the primary heating at a time different from a preset control cycle that defines a power supply time in the primary heating and the secondary heating.

Abstract: A fixing device includes an endless belt rotatable in a given direction of rotation and a thermal conductor to conduct heat from a heater to the endless belt. A pressure rotator is pressed against the endless belt to form a fixing nip therebetween. An abutment contacts the endless belt to restrict a trajectory of the endless belt to bring the endless belt into contact with the thermal conductor in a particular circumferential span spanning from a particular position upstream from the fixing nip to the fixing nip in the direction of rotation of the endless belt and to separate the endless belt from the thermal conductor in at least a part of an outboard circumferential span outboard from the particular circumferential span in the direction of rotation of the endless belt.

Abstract: An image forming apparatus includes an image forming device to form a cleaning toner image in a cleaning region on a cleaning sheet and a check toner image in a check region on the cleaning sheet. The image forming apparatus further includes a fixing device including a first rotator and a heater to heat the first rotator to a cleaning temperature that is lower than a fixing temperature to which the first rotator is heated in a print job and higher than a cold offset temperature at which toner adheres to the first rotator by cold offset. Each of the cleaning region and the check region has a length greater than a circumferential length of the first rotator. The cleaning region and the check region are disposed at a leading section and a trailing section of the cleaning sheet in a cleaning sheet conveyance direction, respectively.

Abstract: A fixing device includes a first support and a second support to rotatably support a fixing rotator at a first lateral end and a second lateral end of the fixing rotator in an axial direction thereof. A first stopper is mounted on the first support. A second stopper is mounted on the second support. A first skew restraint projects from an outer circumferential surface of the fixing rotator radially at the first lateral end of the fixing rotator in the axial direction thereof. A second skew restraint projects from the outer circumferential surface of the fixing rotator radially at the second lateral end of the fixing rotator in the axial direction thereof. The second skew restraint comes into contact with the second stopper as the fixing rotator moves in the axial direction thereof toward the first support.

Abstract: A fixing device includes a heat generator including a first non-conductive portion having a first width in an axial direction of the heat generator and a second non-conductive portion spaced apart from the first non-conductive portion in a circumferential direction of the heat generator and having a second width in the axial direction of the heat generator that is smaller than the first width of the first non-conductive portion. The heat generator is movable between a first heating position where the first non-conductive portion is disposed opposite an exciting coil unit and a second heating position where the second non-conductive portion is disposed opposite the exciting coil unit.

Abstract: A fixing device includes an endless belt rotatable in a given direction of rotation and a thermal conductor to conduct heat from a heater to the endless belt. A pressure rotator is pressed against the endless belt to form a fixing nip therebetween. An abutment contacts the endless belt to restrict a trajectory of the endless belt to bring the endless belt into contact with the thermal conductor in a particular circumferential span spanning from a particular position upstream from the fixing nip to the fixing nip in the direction of rotation of the endless belt and to separate the endless belt from the thermal conductor in at least a part of an outboard circumferential span outboard from the particular circumferential span in the direction of rotation of the endless belt.

Abstract: A fixing device temperature control method includes selectively energizing at least one of a plurality of heaters that heats a fixing rotary body according to an image area on a recording medium where a toner image is formed on the recording medium, detecting a temperature of a pressing rotary body pressed against the fixing rotary body, and controlling the energized, at least one of the plurality of heaters based on the detected temperature of the pressing rotary body so as to heat the fixing rotary body to a target temperature. The image area on the recording medium corresponds to a plurality of axial heating spans on the fixing rotary body.

Abstract: A fixing device includes a fixing rotary body, an opposed member opposing the fixing rotary body to form a nipping portion, and a heater to heat the fixing rotary body. The heater includes heat generators arranged in a width direction of a recording medium and separately supplied with power. When an unfixed image on the medium has an image area and a non-image area, power supplied to each of the heat generators is controlled so that, of the heat generators, a first heat generator corresponding to the image area becomes a higher temperature and second heat generators corresponding to the non-image area becomes a lower temperature. When the second heat generators are adjacent to each other, power supplied to one of the second heat generators closer to the image area is set to be greater than power supplied to another of the second heat generators farther from the image area.

Abstract: An image forming apparatus includes a controller including a primary heating control portion that determines a first amount of power supplied to a heater based on a temperature of a fixing rotator detected by a temperature detector and controls the heater to perform a primary heating to heat the fixing rotator with the first amount of power, a secondary heating control portion that controls the heater to perform a secondary heating to heat the fixing rotator with a preset second amount of power, and a switch portion that controls the heater to switch between the primary heating and the secondary heating during an identical print job without changing a target temperature of the fixing rotator.

Abstract: An image forming apparatus includes a controller including a primary heating control portion to control a heater to perform a primary heating to heat a fixing rotator with a first amount of power determined based on a temperature of the fixing rotator, a secondary heating control portion to control the heater to perform a secondary heating to heat the fixing rotator with a preset second amount of power, and a switch portion to control the heater to switch between the primary heating and the secondary heating during an identical print job and to perform at least one of a primary switching from the primary heating to the secondary heating and a secondary switching from the secondary heating to the primary heating at a time different from a preset control cycle that defines a power supply time in the primary heating and the secondary heating.

Abstract: A fixing device includes a rotatable fixing member to rotate while contacting an unfixed image; a pressure member to form a fixing nip with the fixing member; a heating member having a plurality of heating elements divided in a direction perpendicular to a conveyance direction of a sheet; a heat performance sensor to detect heating performance of each heating element of the heating member, and a controller to control the heating member. The controller controls each heating element independently such that a temperature of a portion of the fixing member corresponding to a blank area becomes lower than the temperature of a portion of the fixing member corresponding to an image area; and controls the temperature to be maintained at each heating element based on the detection result of the heating performance of each heating element detected by the heat performance sensor.

Abstract: A fixing device includes a fixing rotary body, an opposed member, a heater, and a heating controller. The opposed member opposes the fixing rotary body to form a nipping portion therebetween. The heater includes heat generators arranged in a width direction of a recording medium. When the recording medium fed to the nipping portion has an image area and a non-image area, the heating controller controls the outputs of the heat generators based on image information so that a first heat generator of the heat generators corresponding to the image area is higher in temperature and a second heat generator of the heat generators corresponding to the non-image area is lower in temperature. Based on information other than the image information, the heating controller temporarily shifts an area of the fixing rotary body corresponding to the non-image area to a temperature differing from a normal temperature.

Abstract: A fixing device includes an endless belt formed into a loop and rotatable in a given direction of rotation. An opposed rotary body contacts the endless belt to form a fixing nip therebetween through which a recording medium bearing a toner image is conveyed. A heater is disposed in proximity to an irradiation span spanning on an inner circumferential surface of the endless belt in a circumferential direction thereof to emit light that irradiates and heats the irradiation span of the endless belt. A shield is interposed between the heater and the irradiation span of the endless belt in a diametrical direction thereof to shield the irradiation span of the endless belt from heated air surrounding the heater.

Abstract: A fixing device includes a fixing rotator formed into a loop and rotatable in a predetermined direction of rotation and a pressure rotator disposed outside the loop formed by the fixing rotator and pressed against the fixing rotator to form a fixing nip therebetween through which a recording medium bearing a toner image is conveyed. A stay is disposed opposite the pressure rotator via the fixing rotator. A heater is disposed opposite an inner circumferential surface of the fixing rotator to heat the fixing rotator. A pressurization member is pressed against the heater via the fixing rotator. A housing is interposed between the stay and the heater. A temperature detector is mounted on the housing to detect a temperature of the heater.

Abstract: A fixing device includes a first support and a second support to rotatably support a fixing rotator at a first lateral end and a second lateral end of the fixing rotator in an axial direction thereof. A first stopper is mounted on the first support. A second stopper is mounted on the second support. A first skew restraint projects from an outer circumferential surface of the fixing rotator radially at the first lateral end of the fixing rotator in the axial direction thereof. A second skew restraint projects from the outer circumferential surface of the fixing rotator radially at the second lateral end of the fixing rotator in the axial direction thereof. The second skew restraint comes into contact with the second stopper as the fixing rotator moves in the axial direction thereof toward the first support.

Abstract: A fixing device includes a rotatable, endless fixing belt; a rotatable contact member configured to contact a circumferential surface of the fixing belt to form a nip in association with the fixing belt; and a heating member disposed at an interior surface of the fixing belt, configured to heat the fixing belt. The heating member includes a multiple heat sources arranged along the width of a sheet of recording media in a direction perpendicular to a sheet conveyance direction. A controller changes an area to be heated by each heat source based on image data and corresponding to an unfixed image on the sheet. The fixing belt is heated by the heating member so that the unfixed image on the sheet that has been conveyed to the nip is fixed onto the sheet at least with heat. The heating member is disposed at a portion other than the fixing nip.

Abstract: A fixing device includes a rotatable fuser member, a rotatable pressure member, a heater, a rotary driver, a thermometer, and a controller. The rotatable fuser member is subjected to heating. The rotatable pressure member is disposed opposite the fuser member. The heater heats the fuser member. The rotary driver imparts torque to at least one of the fuser and pressure members. The fuser member and the pressure member are pressed against each other to form a fixing nip therebetween. The thermometer is disposed external to the fixing nip to detect a temperature outside the fixing nip. The controller is operatively connected with the thermometer to control an amount of heat applied to the recording medium through the fixing nip according to the detected temperature, so that the recording medium exhibits a substantially constant post-fixing temperature downstream from the fixing nip.