Abstract: A fixing device includes a fixing rotator, a first heater, a second heater, and circuitry. The first heater heats a region on the fixing rotator to heat a recording medium having a width smaller than a predetermined width. The second heater heats a region on the fixing rotator to heat a maximum recording medium used in the fixing device. The second heater has a heat generation distribution in which a heat generation amount of each of both end portions corresponding to both end portions of the maximum recording medium in a width direction of the recording medium is larger than a heat generation amount of a center portion. The circuitry determines whether to turn on the first heater and turn off the second heater or to turn on both the first heater and the second heater based on a required power to bring the fixing rotator to a fixing temperature.

Abstract: A fixing device includes a fixing rotator over which a recording medium bearing an image is conveyed. A first heater heats the fixing rotator and generates heat evenly in a maximum conveyance span where the recording medium having a maximum width in a width direction of the recording medium is conveyed. The maximum width is available for the fixing rotator. A second heater heats the fixing rotator and generates heat in the maximum conveyance span. The second heater includes a first portion that generates heat in a first heat generation amount and a second portion that generates heat in a second heat generation amount that is greater than the first heat generation amount of the first portion.

Abstract: A fixing device includes a fixing rotator over which a recording medium bearing an image is conveyed. A first heater heats the fixing rotator and generates heat evenly in a maximum conveyance span where the recording medium having a maximum width in a width direction of the recording medium is conveyed. The maximum width is available for the fixing rotator. A second heater heats the fixing rotator and generates heat in the maximum conveyance span. The second heater includes a first portion that generates heat in a first heat generation amount and a second portion that generates heat in a second heat generation amount that is greater than the first heat generation amount of the first portion.

Abstract: A fixing device includes an endless first rotator, a second rotator configured to contact and press the first rotator, a heater configured to heat the first rotator, a heater support, and a thermal equalizer contacting the first rotator to uniform a temperature distribution in an axial direction of the first rotator. The heater support supports the heater by a clearance fit.

Abstract: A fixing device includes a belt, an opposed rotator, a nip formation pad, a heater, a stay, and a positioner. The nip formation pad has a plurality of projections in a longitudinal direction of the nip formation pad. The positioner is disposed between the nip formation pad and the stay to position the nip formation pad. The positioner has a plurality of insertion holes arranged in a longitudinal direction of the positioner to accept the projections and restrict movement of the nip formation pad with respect to the positioner in a rotation direction of the belt and a direction opposite the rotation direction. The plurality of insertion holes includes an insertion hole disposed at a position corresponding to an end portion of the nip formation pad to accept two or more projections of the projections arranged in the longitudinal direction of the nip formation pad.

Abstract: A fixing device includes an endless first rotator, a second rotator configured to contact and press the first rotator, a heater configured to heat the first rotator, a heater support, and a thermal equalizer contacting the first rotator to uniform a temperature distribution in an axial direction of the first rotator. The heater support supports the heater by a clearance fit.

Abstract: A fixing device that includes a rotatable endless fixing member, a fixing heat source which heats the fixing member, a pressure member provided on the outside of the fixing member and facing the fixing member, a nip forming member provided inside the fixing member and forming a fixing nip between the fixing member and the pressure member, a nip forming support member for supporting the nip forming member, a high-thermal-conductive member provided between the fixing member and the nip forming member, an adhesive provided between the high-thermal-conductive member and the nip forming member. The thermal conductivity of the adhesive is larger than the thermal conductivity of the nip forming member and lower than the thermal conductivity of the high-thermal-conductive member.

Abstract: A fixing device includes a belt, an opposed rotator, a nip formation pad, a heater, a stay, and a positioner. The nip formation pad has a plurality of projections in a longitudinal direction of the nip formation pad. The positioner is disposed between the nip formation pad and the stay to position the nip formation pad. The positioner has a plurality of insertion holes arranged in a longitudinal direction of the positioner to accept the projections and restrict movement of the nip formation pad with respect to the positioner in a rotation direction of the belt and a direction opposite the rotation direction. The plurality of insertion holes includes an insertion hole disposed at a position corresponding to an end portion of the nip formation pad to accept two or more projections of the projections arranged in the longitudinal direction of the nip formation pad.

Abstract: A fixing device that includes a rotatable endless fixing member, a fixing heat source which heats the fixing member, a pressure member provided on the outside of the fixing member and facing the fixing member, a nip forming member provided inside the fixing member and forming a fixing nip between the fixing member and the pressure member, a nip forming support member for supporting the nip forming member, a high-thermal-conductive member provided between the fixing member and the nip forming member, an adhesive provided between the high-thermal-conductive member and the nip forming member. The thermal conductivity of the adhesive is larger than the thermal conductivity of the nip forming member and lower than the thermal conductivity of the high-thermal-conductive member.

Abstract: A fixing method is provided including the step of fixing a toner on a recording medium with a fixing device. The toner has a binder resin, a colorant, and a release agent, and has a release agent amount indicator of from 0.01 to 0.20. The release agent amount indicator is represented by a ratio (P2850/P828) of an intensity (P2850) at a wave number of 2,850 cm?1 to an intensity (P828) at a wave number of 828 cm?1 of the toner measured by a Fourier transform infrared spectroscopy attenuated total reflection method. The fixing device includes a fixing rotator driven to rotate by a driving source, a pressure rotator driven to rotate by rotation of the fixing rotator, a fixing belt interposed between the fixing rotator and the pressure rotator, and a heater to heat the fixing belt.

Abstract: A fixing device includes an endless fixing rotator, a heater, a nip formation assembly, and an opposed rotator. The endless fixing rotator is rotatable in a direction of rotation. The heater heats the fixing rotator. The nip formation assembly is disposed opposite an inner circumferential surface of the fixing rotator. The opposed rotator is pressed against the nip formation assembly via the fixing rotator to form a fixing nip between the fixing rotator and the opposed rotator. The nip formation assembly includes a nip former to contact the inner circumferential surface of the fixing rotator, maintain a constant thickness against pressure from the opposed rotator, and transfer heat. The opposed rotator is shorter than the nip former in a longitudinal direction of the opposed rotator. The opposed rotator is disposed within an area opposite the nip former.

Abstract: A fixing method is provided including the step of fixing a toner on a recording medium with a fixing device. The toner comprises a binder resin, a colorant, and a release agent, and has a release agent amount indicator of from 0.01 to 0.20. The release agent amount indicator is represented by a ratio (P2850/P828) of an intensity (P2850) at a wave number of 2,850 cm?1 to an intensity (P828) at a wave number of 828 cm?1 of the toner measured by a Fourier transform infrared spectroscopy attenuated total reflection method. The fixing device includes a fixing rotator driven to rotate by a driving source, a pressure rotator driven to rotate by rotation of the fixing rotator, a fixing belt interposed between the fixing rotator and the pressure rotator, and a heater to heat the fixing belt.

Abstract: A fixing device includes an endless belt and a pressure rotator disposed opposite an outer circumferential surface of the endless belt. The pressure rotator has a first span in an axial direction of the endless belt. A nip formation pad, which is disposed opposite an inner circumferential surface of the endless belt, forms a fixing nip between the endless belt and the pressure rotator. The nip formation pad includes a belt-side face disposed opposite the endless belt. A radiant heater, which is disposed opposite the inner circumferential surface of the endless belt, heats the endless belt. A thermal conduction aid, which contacts the belt-side face of the nip formation pad, conducts heat in the axial direction of the endless belt. The thermal conduction aid has a second span within which the first span of the pressure rotator is provided at the fixing nip.

Abstract: A fixing device includes an endless fixing belt, a heat source, an opposed member, a nip formation pad, and a heat conductive member. The nip formation pad includes an abutment region, a first opening portion, and second opening portions. The abutment region includes a plurality of abutment surfaces abutting a first face of the heat conductive member. The first opening portion is disposed at a center of the abutment region to form a non-contact area at which the nip formation pad does not contact the heat conductive member. The abutment region includes an upstream abutment area and a downstream abutment area from the first opening portion in a direction of conveyance of a recording medium. The second opening portions divide at least one area of the upstream abutment area and the downstream abutment area into a plurality of portions in a longitudinal direction of the nip formation pad.

Abstract: A fixing device includes a fixing rotator, an opposed rotator disposed opposite the fixing rotator, a pressure pad, a lateral end heater, and a thermal conduction aid. The pressure pad presses against the opposed rotator via the fixing rotator to form a fixing nip between the fixing rotator and the opposed rotator. The lateral end heater is disposed on the pressure pad to heat a lateral end of the fixing rotator in the axial direction of the fixing rotator. The thermal conduction aid is interposed between the pressure pad and the fixing rotator to decrease a temperature gradient of the fixing rotator in an axial direction of the fixing rotator. The pressure pad includes a nip-side face disposed opposite the thermal conduction aid. The lateral end heater includes a nip-side face being disposed opposite the thermal conduction aid and projecting beyond the nip-side face of the pressure pad.

Abstract: A fixing device includes a fixing rotator, a plurality of heat sources having different heat distributions to heat the fixing rotator, a pressing member to press the fixing rotator and form a nip to fix the unfixed toner image on the recording material, a shield disposed between the plurality of heat sources, a plurality of temperature sensors each disposed opposite to the heat source, a processor to control the plurality of heat sources so that a temperature detected by the temperature sensor becomes a predetermined target temperature. The processor controls the heaters so that a temperature difference ?T=T2?T1 becomes greater than zero, wherein T1 is the target temperature for the temperature sensor close to an entrance of the nip, and T2 is the target temperature for the temperature sensor far from the entrance of the nip.

Abstract: A fixing device includes a fixing sleeve, a pair of holders, a heater, a nip formation pad, a pressing member, a pressing mechanism, and a controller. The nip formation pad has a regular crown-shaped surface abutted against an inner surface of the fixing sleeve. The pressing member forms a nip with the nip formation pad in a state of abutting against the fixing sleeve. The controller controls the pressing mechanism in a first mode in which the pressing mechanism presses the pressing member toward the nip formation pad with a first pressing force to equalize a width of the nip and a second mode in which the pressing mechanism presses the pressing member with a second pressing force greater than the first pressing force so that the width of the nip is smaller at both ends than at a center of the nip.

Abstract: A fixing device includes an endless fixing rotator, a heater, a nip formation assembly, and an opposed rotator. The endless fixing rotator is rotatable in a direction of rotation. The heater heats the fixing rotator. The nip formation assembly is disposed opposite an inner circumferential surface of the fixing rotator. The opposed rotator is pressed against the nip formation assembly via the fixing rotator to form a fixing nip between the fixing rotator and the opposed rotator. The nip formation assembly includes a nip former to contact the inner circumferential surface of the fixing rotator, maintain a constant thickness against pressure from the opposed rotator, and transfer heat. The opposed rotator is shorter than the nip former in a longitudinal direction of the opposed rotator. The opposed rotator is disposed within an area opposite the nip former.

Abstract: A fixing device includes a rotatable endless belt formed into a loop and a heater disposed opposite the endless belt to heat the endless belt. A nip formation pad is disposed inside the loop formed by the endless belt. The nip formation pad includes a metallic thermal equalizer extending in an axial direction of the endless belt. A rotatable pressure rotator presses against the nip formation pad via the endless belt to form a fixing nip between the endless belt and the pressure rotator, through which a recording medium bearing a toner image is conveyed. The pressure rotator includes an increased tackiness portion disposed at a lateral end of the pressure rotator in an axial direction of the pressure rotator to transmit a driving force to the endless belt. The increased tackiness portion is disposed opposite the thermal equalizer of the nip formation pad.

Abstract: A fixing device includes a fixing rotator, a plurality of heat sources having different heat distributions to heat the fixing rotator, a pressing member to press the fixing rotator and form a nip to fix the unfixed toner image on the recording material, a shield disposed between the plurality of heat sources, a plurality of temperature sensors each disposed opposite to the heat source, a processor to control the plurality of heat sources so that a temperature detected by the temperature sensor becomes a predetermined target temperature. The processor controls the heaters so that a temperature difference ?T=T2?T1 becomes greater than zero, wherein T1 is the target temperature for the temperature sensor close to an entrance of the nip, and T2 is the target temperature for the temperature sensor far from the entrance of the nip.