Abstract: A sheet stacker includes a sheet stacking member, a biasing force applier, an angle changer, and a biasing force change reducer. The sheet stacking member has an upstream portion in a sheet conveyance direction. The upstream portion is movable in a vertical direction. The biasing force applier is configured to bias the sheet stacking member upward. The angle changer is configured to change an angle of a sheet stacking face of the sheet stacking member, relative to a surface of a sheet conveyed through a sheet conveying portion. The biasing force change reducer is configured to restrain a change of a biasing force acting on the sheet stacking member, before and after a change of the angle of the sheet stacking member by the angle changer.

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 sheet stacker includes a sheet stacking member, a biasing force applier, an angle changer, and a biasing force change reducer. The sheet stacking member has an upstream portion in a sheet conveyance direction. The upstream portion is movable in a vertical direction. The biasing force applier is configured to bias the sheet stacking member upward. The angle changer is configured to change an angle of a sheet stacking face of the sheet stacking member, relative to a surface of a sheet conveyed through a sheet conveying portion. The biasing force change reducer is configured to restrain a change of a biasing force acting on the sheet stacking member, before and after a change of the angle of the sheet stacking member by the angle changer.

Abstract: A sheet ejection device includes a sheet stacker, a retainer, and a biasing member. The sheet stacker has a stacker face and a coupling portion. The sheet stacker is configured to stack a sheet on the stacker face. The retainer has a coupling portion and an adjuster configured to rotate the sheet stacker to adjust an angle of the stacker face. The retainer is configured to retain the sheet stacker to be movable in a vertical direction. The biasing member is coupled to the sheet stacker and the retainer to apply a biasing force to bias the sheet stacker in an upward direction to the retainer. The sheet stacker is configured to move in a downward direction against the biasing force, as a number of sheets stacked on the stacker face increases. The coupling portion of the retainer is configured to move when the adjuster rotates the sheet stacker.

Abstract: A separation member that is used to separate a conveyance object from two rotation members, the conveyance object having been sent out from a nip that is formed by the two rotation members that are in contact with one another, the separation member includes a wavy part directed toward the nip and inclined from a normal to a center line of the two rotation members at a predetermined angle. The wavy part covers a contact zone where the conveyance object can come into contact with the separation member along a conveyance direction and along a width direction of the conveyance object, and the wavy part has a plurality of depressions parallel to each other and extending in a direction inclined from the conveyance direction and inclined from the width direction, at least two of the depressions overlapping along the conveyance direction.

Abstract: A fixing device includes a tubular rotator and a first heater disposed inside the tubular rotator and extended in a longitudinal direction of the first heater. The first heater heats the tubular rotator. A second heater is disposed inside the tubular rotator and extended in a longitudinal direction of the second heater. The second heater heats the tubular rotator. A heating adjuster is interposed between the first heater and the second heater. The heating adjuster adjusts heat conduction from the first heater to the second heater. A joint combines the heating adjuster with the second heater.

Abstract: A separation member that is used to separate a conveyance object from two rotation members, the conveyance object having been sent out from a nip that is formed by the two rotation members that are in contact with one another, the separation member includes a wavy part directed toward the nip and inclined from a normal to a center line of the two rotation members at a predetermined angle. The wavy part covers a contact zone where the conveyance object can come into contact with the separation member along a conveyance direction and along a width direction of the conveyance object, and the wavy part has a plurality of depressions parallel to each other and extending in a direction inclined from the conveyance direction and inclined from the width direction, at least two of the depressions overlapping along the conveyance direction.

Abstract: A fixing device includes a separator disposed downstream from a nip former in a recording medium conveyance direction and isolated from a pressure rotator via a fixing belt. The separator stretches the fixing belt. A presser is interposed between a fixing nip formed between the living belt and the pressure rotator and an upstream end of the separator in a rotation direction of the fixing belt. The presser comes into contact with an inner circumferential surface of the fixing belt to press the fixing belt against the pressure rotator. A pressure adjuster, contacting the pressure rotator, changes a pressing position of the pressure rotator relative to the fixing belt to adjust pressure exerted from the pressure rotator to the fixing belt. A presser position adjuster, contacting the presser, changes a presser position of the presser relative to the fixing belt according to the pressing position of the pressure rotator.

Abstract: A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A separator is disposed downstream from the nip former in a recording medium conveyance direction and stretches the fixing belt. The separator is spaced apart from the pressure rotator via the fixing belt. A presser is interposed between an exit of the fixing nip and an upstream end of the separator in the rotation direction of the fixing belt. The presser comes into contact with an inner circumferential surface of the fixing belt to press the fixing belt against the pressure rotator.

Abstract: A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt and including an elastic layer as a surface layer. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A presser is disposed downstream from an exit of the fixing nip in a recording medium conveyance direction. The presser brings the fixing belt into contact with the pressure rotator.

Abstract: A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A presser is disposed downstream from an exit of the fixing nip in a recording medium conveyance direction. The presser brings the fixing belt into contact with the pressure rotator. A gap retainer contacts the nip former and is coupled to the presser to retain isolation of the presser from the nip former.

Abstract: A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A presser is disposed downstream from an exit of the fixing nip in the rotation direction of the fixing belt. The presser brings the fixing belt into contact with the pressure rotator. A mover is coupled to the presser to move the presser between a contact position where the presser brings the fixing belt into contact with the pressure rotator and an isolation position where the presser isolates the fixing belt from the pressure rotator.

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: A fixing device includes an endless fixing belt stretched taut across a first roller and a second roller and rotatable in a predetermined direction of rotation. A pressure rotator is pressed against the first roller via the fixing belt to form a fixing nip between the pressure rotator and the fixing belt, through which a recording medium is conveyed. A separation aid, disposed downstream from the fixing nip in the direction of rotation of the fixing belt to separate the recording medium from the fixing belt, includes a contact face contacting an inner circumferential surface of the fixing belt and a bulge disposed at a center of the contact face in a longitudinal direction of the separation aid. The bulge projects toward the inner circumferential surface of the fixing belt relative to each lateral end of the contact face in the longitudinal direction of the separation aid.

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 fixing device includes a tubular rotator and a first heater disposed inside the tubular rotator and extended in a longitudinal direction of the first heater. The first heater heats the tubular rotator. A second heater is disposed inside the tubular rotator and extended in a longitudinal direction of the second heater. The second heater heats the tubular rotator. A heating adjuster is interposed between the first heater and the second heater. The heating adjuster adjusts heat conduction from the first heater to the second heater. A joint combines the heating adjuster with the second heater.

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 a separator disposed downstream from a nip former in a recording medium conveyance direction and isolated from a pressure rotator via a fixing belt. The separator stretches the fixing belt. A presser is interposed between a fixing nip formed between the living belt and the pressure rotator and an upstream end of the separator in a rotation direction of the fixing belt. The presser comes into contact with an inner circumferential surface of the fixing belt to press the fixing belt against the pressure rotator. A pressure adjuster, contacting the pressure rotator, changes a pressing position of the pressure rotator relative to the fixing belt to adjust pressure exerted from the pressure rotator to the fixing belt. A presser position adjuster, contacting the presser, changes a presser position of the presser relative to the fixing belt according to the pressing position of the pressure rotator.

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.