Abstract: A snap ring is set to a set portion of a shaft of a rotator from a direction orthogonal to an axial direction of the shaft. The snap ring includes a first arcuate portion and a second arcuate portion facing each other, being elastically deformable in directions away from each other, holding the set portion by elastic deformation restoring force. One ends of the first and second arcuate portions are away from each other to form an insertion portion to insert the set portion. When the snap ring is not used, the first arcuate portion has a same radius of curvature as the second arcuate portion and the set portion, and a center of curvature closer to the second arcuate portion than the first arcuate portion, and the second arcuate portion has a center of curvature closer to the first arcuate portion than the second arcuate portion.

Abstract: A sheet conveying device, which is included in a fixing device and an image forming apparatus, includes a sheet contacting body and a lateral relative position shifting body. The sheet contacting body is configured to contact a sheet to be conveyed. The lateral relative position shifting body is configured to shift a passing position of the sheet being conveyed toward the sheet contacting body, in a width direction perpendicular to a sheet conveying direction and a relative position to the sheet contacting body, each time the sheet is conveyed by a number of sheets based on a setting. The setting of the number of sheets varies based on information of the sheet.

Abstract: A snap ring is set to a set portion of a shaft of a rotator from a direction orthogonal to an axial direction of the shaft. The snap ring includes a first arcuate portion and a second arcuate portion facing each other, being elastically deformable in directions away from each other, holding the set portion by elastic deformation restoring force. One ends of the first and second arcuate portions are away from each other to form an insertion portion to insert the set portion. When the snap ring is not used, the first arcuate portion has a same radius of curvature as the second arcuate portion and the set portion, and a center of curvature closer to the second arcuate portion than the first arcuate portion, and the second arcuate portion has a center of curvature closer to the first arcuate portion than the second arcuate portion.

Abstract: A fixing device includes an endless belt rotatable in a predetermined direction of rotation and a nip formation assembly disposed opposite an inner circumferential surface of the endless belt. An opposed rotary body is pressed against the nip formation assembly via the endless belt to form a fixing nip between the endless belt and the opposed rotary body through which a recording medium bearing a toner image is conveyed. A belt holder contacts and supports each lateral end of the endless belt in an axial direction thereof. The belt holder is isolated from the opposed rotary body with a first interval interposed therebetween in the axial direction of the endless belt.

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 controller includes a plurality of voltage detectors to detect voltages of a plurality of power sources for supplying power to a plurality of heaters to heat a fixing member of a fixing device that fixes a toner image on a recording medium and a heater controller to execute duty control to turn on the plurality of heaters. The heater controller corrects a duty of at least one of the plurality of heaters based on the voltages detected by the plurality of voltage detectors and rated output values of the plurality of heaters.

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 a fixing rotator, a pressure rotator, and a pressure assembly that forms a fixing nip therebetween and includes a first adjuster and a second adjuster. The first adjuster includes a pressure cam, a first biasing device, a first pressure lever that holds the pressure rotator, and a second pressure lever that moves with the pressure cam and presses against the first pressure lever via the first biasing device. The first adjuster adjusts a load of the first biasing device to adjust a pressure force from the pressure rotator to the fixing rotator. The second adjuster includes an adjustment screw is driven into the second pressure lever, and a retainer that retains an adjusted state between the adjustment screw and the first pressure lever. The second adjuster adjusts a holding position of the first pressure lever to hold the pressure rotator.

Abstract: An image forming apparatus includes a fixing belt stretched across a first roller and a second roller including an elastic layer. A pressure rotator presses against the second roller via the fixing belt to form a fixing nip between the pressure rotator and the fixing belt. A recording medium bearing a toner image is conveyed through the fixing nip. A clearance detector detects a clearance between the first roller and the second roller. A mover moves the pressure rotator with respect to the second roller in a pressing direction in which the pressure rotator presses against the second roller via the fixing belt and a separation direction in which the pressure rotator separates from the second roller. A controller controls an amount of movement of the pressure rotator moved by the mover toward the second roller based on the clearance detected by the clearance detector.

Abstract: A sheet conveying device, which is included in a fixing device and an image forming apparatus, includes a sheet contacting body and a lateral relative position shifting body. The sheet contacting body is configured to contact a sheet to be conveyed. The lateral relative position shifting body is configured to shift a passing position of the sheet being conveyed toward the sheet contacting body, in a width direction perpendicular to a sheet conveying direction and a relative position to the sheet contacting body, each time the sheet is conveyed by a number of sheets based on a setting. The setting of the number of sheets varies based on information of the sheet.

Abstract: A fixing device includes a fixing rotator, a pressure rotator, and a pressure assembly that forms a fixing nip therebetween and includes a first adjuster and a second adjuster. The first adjuster includes a pressure cam, a first biasing device, a first pressure lever that holds the pressure rotator, and a second pressure lever that moves with the pressure cam and presses against the first pressure lever via the first biasing device. The first adjuster adjusts a load of the first biasing device to adjust a pressure force from the pressure rotator to the fixing rotator. The second adjuster includes an adjustment screw is driven into the second pressure lever, and a retainer that retains an adjusted state between the adjustment screw and the first pressure lever. The second adjuster adjusts a holding position of the first pressure lever to hold the pressure rotator.

Abstract: A fixing device controller includes a plurality of voltage detectors to detect voltages of a plurality of power sources for supplying power to a plurality of heaters to heat a fixing member of a fixing device that fixes a toner image on a recording medium and a heater controller to execute duty control to turn on the plurality of heaters. The heater controller corrects a duty of at least one of the plurality of heaters based on the voltages detected by the plurality of voltage detectors and rated output values of the plurality of heaters.

Abstract: A fixing device includes an endless belt, a drive rotator, a driven rotator, a rotation detector, and circuitry. The drive rotator contacts and rotates the endless belt. The driven rotator contacts an inner circumferential surface of the endless belt. The rotation detector detects a rotational speed of the driven rotator. The circuitry is operatively connected to the rotation detector to control a rotational speed of the drive rotator based on the rotational speed of the driven rotator detected by the rotational detector. The circuitry changes the rotational speed of the drive rotator when a recording medium bearing a toner image is not conveyed over the endless belt.

Abstract: A fixing device includes a heat source; a fixing member looped into a generally cylindrical shape to rotate in a circumferential direction thereof and partially heated by the heat source and to heat a surface of a recording medium bearing an unfixed toner image to fix the unfixed toner image thereon in a fixing process; a rotary pressing member disposed facing the fixing member to form a nip therebetween, through which the recording medium is transported in a transport direction; and a rotation driver to rotate one of the fixing member and the pressing member. In a case in which the fixing member is halted for a reason other than the fixing process while power of the fixing device is on, electric power is not supplied to the heat source and the fixing member is rotated by a predetermined amount or more after the fixing member is halted.

Abstract: An image forming apparatus includes a fixing device. The fixing device includes a rotatable endless fixing member, a nip forming member arranged inside the fixing member, a pressing member in contact with the nip forming member via the fixing member, and a heating source configured to heat the fixing member. When an abnormality occurs in at least one of the fixing device and other devices included in the image forming apparatus, a rotation of the fixing member is stopped prior to stopping a rotation driving of a discharging unit and, after stopping, the fixing member is controlled to rotate.

Abstract: An image forming apparatus includes a fixing belt stretched across a first roller and a second roller including an elastic layer. A pressure rotator presses against the second roller via the fixing belt to form a fixing nip between the pressure rotator and the fixing belt. A recording medium bearing a toner image is conveyed through the fixing nip. A clearance detector detects a clearance between the first roller and the second roller. A mover moves the pressure rotator with respect to the second roller in a pressing direction in which the pressure rotator presses against the second roller via the fixing belt and a separation direction in which the pressure rotator separates from the second roller. A controller controls an amount of movement of the pressure rotator moved by the mover toward the second roller based on the clearance detected by the clearance detector.

Abstract: A fixing device includes: a rotatable endless fixing belt; a nip forming member arranged inside the fixing belt; a facing rotating body that abuts the nip forming member via the fixing belt to form a nip portion with the fixing belt; a heat source that directly heats up the fixing belt at a portion other than the nip portion; and a supporting member that supports the nip forming member. The fixing device conveys a recording medium carrying an unfixed image to the nip portion to fix the unfixed image to the recording medium, and the supporting member includes a rising portion extending in an abutting direction of the facing rotating body against the fixing belt and having a tip close to an inner circumferential surface of the fixing belt, and is set to have a section modulus of 200 mm3 or higher.

Abstract: A separation device includes an endless belt, a rotary body, a separation supporter, and a transfer mechanism. The separation supporter presses against an inner circumferential surface of the endless belt downstream from an area of contact between the endless belt and the rotary body in a recording medium conveyance direction to curve the endless belt toward an outer circumferential surface side of the endless belt at a greater curvature than a curvature of the endless belt at the area of contact between the endless belt and the rotary body. The transfer mechanism switches the separation supporter between a first position and a second position farther from the area of contact between the endless belt and the rotary body than the first position.

Abstract: A fixing device includes an endless belt rotatable in a predetermined direction of rotation and a nip formation assembly disposed opposite an inner circumferential surface of the endless belt. An opposed rotary body is pressed against the nip formation assembly via the endless belt to form a fixing nip between the endless belt and the opposed rotary body through which a recording medium bearing a toner image is conveyed. A belt holder contacts and supports each lateral end of the endless belt in an axial direction thereof. The belt holder is isolated from the opposed rotary body with a first interval interposed therebetween in the axial direction of the endless belt.

Abstract: A fixing device includes an endless belt, a drive rotator, a driven rotator, a rotation detector, and circuitry. The drive rotator contacts and rotates the endless belt. The driven rotator contacts an inner circumferential surface of the endless belt. The rotation detector detects a rotational speed of the driven rotator. The circuitry is operatively connected to the rotation detector to control a rotational speed of the drive rotator based on the rotational speed of the driven rotator detected by the rotational detector. The circuitry changes the rotational speed of the drive rotator when a recording medium bearing a toner image is not conveyed over the endless belt.