Abstract: A fixing device includes a fixing rotator rotatable in a predetermined direction of rotation and a pressure rotator to press against the fixing rotator to form a fixing nip therebetween, through which a recording medium bearing a toner image is conveyed. A rotation load applicator is coupled to one of the fixing rotator and the pressure rotator to apply a rotation load to the one of the fixing rotator and the pressure rotator. The rotation load is in a range of from 0.1 Nm to 0.6 Nm.

Abstract: A fixing device includes an endless, rotatable fixing belt, a pressure rotator, a nip formation pad, a support, and a vibration repressor. The pressure rotator presses an outer surface of the fixing belt. The nip formation pad is disposed at an inner side of the fixing belt, to abut on the pressure rotator with the fixing belt interposed between the nip formation pad and the pressure rotator to form a fixing nip. The support is disposed at the inner side of the fixing belt, to support the nip formation pad. The vibration repressor is disposed between the nip formation pad and the support, to repress vibration of the nip formation pad.

Abstract: A fixing device includes a primary heater, a secondary heater, and a tertiary heater to heat a primary heating span, a secondary heating span, and a tertiary heating span of a fixing rotator, respectively. A primary temperature detector and a secondary temperature detector detect a temperature of the fixing rotator. A tertiary temperature detector detects a temperature of a pressure rotator. A controller selectively performs a primary control mode to de-energize the tertiary heater and a secondary control mode to connect the secondary heater and the tertiary heater in series to energize the primary heater, the secondary heater, and the tertiary heater. The controller energizes the secondary heater and the tertiary heater in the secondary control mode based on the temperature of the fixing rotator and the pressure rotator detected by the secondary temperature detector and the tertiary temperature detector, respectively.

Abstract: A fixing device includes a heater to generate heat and a fixing rotator to rotate while contacting the heater. A pressure rotator presses against the heater via the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator, through which a recording medium bearing a toner image is conveyed. The heater includes an insulative substrate and a resistive heat generation layer mounted on the substrate. The resistive heat generation layer is disposed upstream from a center of the fixing nip in a recording medium conveyance direction.

Abstract: Heat-equalizing rotation of a fixing member and a pressing member for equalizing the distribution of the temperature of a surface of the fixing member in a width direction is performed after a recording medium having a size less than or equal to a predetermined size in the width direction passes a nip portion and before a recording medium having a size greater than the predetermined size in the width direction passes the nip portion. Further, a termination condition of the heat-equalizing rotation is selected from among a plurality of different kinds of termination conditions, based on image formation related information related to next image formation performed after the heat-equalizing rotation.

Abstract: A fixing device includes a fixing rotator rotatable in a predetermined direction of rotation and a pressure rotator to press against the fixing rotator to form a fixing nip therebetween, through which a recording medium bearing a toner image is conveyed. A rotation load applicator is coupled to one of the fixing rotator and the pressure rotator to apply a rotation load to the one of the fixing rotator and the pressure rotator. The rotation load is in a range of from 0.1 Nm to 0.6 Nm.

Abstract: A fixing device includes a primary heater disposed opposite a fixing rotator to heat a circumferential span of the fixing rotator other than a fixing nip formed between the fixing rotator and a pressure rotator and a secondary heater disposed outboard from the primary heater in an axial direction of the fixing rotator to heat the fixing rotator at the fixing nip. The primary heater and the secondary heater heat a bi-heating span of the fixing rotator in the axial direction thereof. The secondary heater heats a mono-heating span of the fixing rotator in the axial direction thereof and generates a decreased amount of heat to be conducted to the bi-heating span of the fixing rotator. The decreased amount of heat is smaller than an increased amount of heat to be conducted to the mono-heating span of the fixing rotator that is heated by the secondary heater only.

Abstract: A fixing device includes a heater to generate heat and a fixing rotator to rotate while contacting the heater. A pressure rotator presses against the heater via the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator, through which a recording medium bearing a toner image is conveyed. The heater includes an insulative substrate and a resistive heat generation layer mounted on the substrate. The resistive heat generation layer is disposed upstream from a center of the fixing nip in a recording medium conveyance direction.

Abstract: A fixing device includes a primary heater, a secondary heater, and a tertiary heater to heat a primary heating span, a secondary heating span, and a tertiary heating span of a fixing rotator, respectively. A primary temperature detector and a secondary temperature detector detect a temperature of the fixing rotator. A tertiary temperature detector detects a temperature of a pressure rotator. A controller selectively performs a primary control mode to de-energize the tertiary heater and a secondary control mode to connect the secondary heater and the tertiary heater in series to energize the primary heater, the secondary heater, and the tertiary heater. The controller energizes the secondary heater and the tertiary heater in the secondary control mode based on the temperature of the fixing rotator and the pressure rotator detected by the secondary temperature detector and the tertiary temperature detector, respectively.

Abstract: A fixing device includes a nip formation pad that presses against a pressure rotator via an endless belt to form a fixing nip between the belt and the pressure rotator, through which a recording medium bearing a toner image is conveyed. A fixing heater is disposed opposite at least a center span of a conveyance span of the belt in an axial direction thereof where the recording medium is conveyed to heat the belt. A first lateral end heater and a second lateral end heater are mounted on the nip formation pad and disposed opposite a first lateral end span and a second lateral end span of an inner circumferential surface of the belt in the axial direction thereof, respectively, to heat the belt. The second lateral end heater is electrically connected in series to the first lateral end heater.

Abstract: A fixing device includes a rotatable fuser member, a rotatable pressure member, a heater, and a controller. The rotatable fuser member is subjected to heating. The rotatable pressure member is disposed opposite the fuser member. The pressure member presses against the fuser member to form a fixing nip therebetween, through which multiple recording media, each spaced apart from each other by an interval distance in a conveyance direction, are sequentially conveyed at a conveyance speed. The heater is disposed adjacent to the fuser member to heat the fuser member. The controller is operatively connected to the heater to control power supply to the heater through a series of on-off switching control cycles, each including an on-time during which the heater power supply is on, and an off-time during which the heater power supply is off, in synchronization with conveyance of the recording medium.

Abstract: An image forming apparatus includes a conveyance passage unit, a fixing device, an optical sensor, a fixing condition adjuster, and a regulator. A recording medium passes through the conveyance passage unit. The fixing device fixes a toner image onto the recording medium. The optical sensor includes a light-emitting device and a light-receiving device to detect smoothness of the recording medium according to strength of light received. The fixing condition adjuster adjusts fixing conditions according to the smoothness detected. The regulator is disposed in the conveyance passage unit to regulate conveyance of the recording medium, such that at least a part of the recording medium passes through an irradiated area including an intersection that is determined by an emission angle of a first optical axis of light emitted by the light-emitting device and a reflection angle of a second optical axis of light received by the light-receiving device.

Abstract: An image forming apparatus includes an image forming device to form a toner image on a recording medium under a prescribed image forming condition, a fixing device to fix the toner image borne on the recording medium thereonto by heating the recording medium based on target fixing temperature, and a detector to detect a type of recording medium. The type is used in setting at least one of the image forming condition and the target fixing temperature. The inequality Tb>Ta is established when Ta represents a time period needed to reach a setting of fixing temperature allocated to the recording medium with its tip detected by the detector after detection of the tip and Tb represents a time period needed for the recording medium with its tip detected by the detector to reach the fixing device after detection of the tip.

Abstract: An image forming apparatus for forming an image on each of recording media includes an optical sensor to irradiate each of the recording media with light to detect smoothness of each of the recording media according to a strength of specularly reflected light of the light with which each of the recording media is irradiated, and a processor to compare the smoothness of the recording media to determine whether a normal image can be formed on one of the recording media having a smoothness detected last.

Abstract: When calculating an actual turn-on duty based on a required duty according to a feedback control, the actual turn-on duty is corrected using a correction table or a correction conversion formula such that a required turn-on duty and the actual turn-on duty coincide with each other. A fixing heater is controlled according to the corrected actual turn-on duty.

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: A fixing device includes a rotatable fuser member, a rotatable pressure member, a heater, and a controller. The rotatable fuser member is subjected to heating. The rotatable pressure member is disposed opposite the fuser member. The pressure member presses against the fuser member to form a fixing nip therebetween, through which multiple recording media, each spaced apart from each other by an interval distance in a conveyance direction, are sequentially conveyed at a conveyance speed. The heater is disposed adjacent to the fuser member to heat the fuser member. The controller is operatively connected to the heater to control power supply to the heater through a series of on-off switching control cycles, each including an on-time during which the heater power supply is on, and an off-time during which the heater power supply is off, in synchronization with conveyance of the recording medium.

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.