Abstract: A fixing device includes a nip formation pad to press against a fixing rotator. A primary heater is disposed opposite the fixing rotator in a primary heating span spanning in an axial direction of the fixing rotator to heat the primary heating span of the fixing rotator from which heat is conducted to the nip formation pad with a primary conduction. A secondary heater is disposed opposite the fixing rotator in a secondary heating span that is outboard from the primary heating span in the axial direction of the fixing rotator. The secondary heater is interposed between a first nip formation portion and a second nip formation portion of the nip formation pad to heat the secondary heating span of the fixing rotator through the nip formation pad from which heat is conducted to the fixing rotator with a secondary conduction greater than the primary conduction.

Abstract: According to an embodiments, a fixing device includes: an endless fixing member; a heating unit that is provided inside an inner peripheral surface of the fixing member; and a nip forming unit that comes into press-contact with a rotationally driven pressing member with the fixing member interposed therebetween to form a nip. The nip forming unit has a shape in which a center of a contact surface protrudes toward the pressing member compared to both ends. The nip forming unit has a protruding amount at a center toward the pressing member compared to both ends of the nip forming unit in no-load state is set to be less than a bent amount of the nip forming unit when the nip forming unit comes into press-contact with the pressing member with the fixing member interposed therebetween.

Abstract: A fixing device includes a flexible, tubular fixing rotator rotatable in a predetermined direction of rotation and an opposed rotator disposed opposite the fixing rotator. A nip formation pad presses against the opposed rotator via the fixing rotator to form a fixing nip between the fixing rotator and the opposed rotator, through which a recording medium bearing a toner image is conveyed. A fixing heater is disposed opposite at least a conveyance span of the fixing rotator in an axial direction thereof where the recording medium is conveyed to heat the fixing rotator. A lateral end heater is mounted on the nip formation pad and disposed opposite an inner circumferential surface of the fixing rotator at a lateral end of the fixing rotator in the axial direction thereof to heat the fixing rotator. A supplementary thermal conductor contacts the fixing rotator and the lateral end heater.

Abstract: A method for manufacturing a mill roll including a preheating process for joining end portions 16 to 19 of a roll barrel member 13 and/or shaft materials 14, 15, and a friction pressure welding process strongly pressing and joining the shaft materials 14, 15 to a core material 11 after frictionally heating the joining end portions 16 to 19 by rotating the shaft materials 14, 15 while pressing to the core material 11, and a manufacturing apparatus including first and second holding means 29, 23 for the roll barrel member 13 and the shaft materials 14, 15, a rotating means rotating the shaft materials 14, 15, a pressing means 24 pressing the core material 11 and the shaft materials 14, 15 in an axial direction, and a preheating means 31 preheating the joining end portions 16 to 19 of the roll barrel member 13 and the shaft materials 14, 15.

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 fixing rotator and an opposed rotator pressed against the fixing rotator to form a fixing nip therebetween. A primary heater is disposed opposite the fixing rotator in a circumferential span of the fixing rotator other than the fixing nip in a circumferential direction of the fixing rotator to heat the fixing rotator. A heat shield is interposed between the primary heater and the fixing rotator and disposed outboard from at least a decreased size recording medium conveyance span of the fixing rotator spanning in an axial direction of the fixing rotator where a recording medium having a decreased size in the axial direction of the fixing rotator is conveyed. The heat shield shields the fixing rotator from the primary heater. A secondary heater is mounted on the heat shield to heat the fixing rotator.

Abstract: A method for manufacturing a mill roll including a preheating process for joining end portions 16 to 19 of a roll barrel member 13 and/or shaft materials 14, 15, and a friction pressure welding process strongly pressing and joining the shaft materials 14, 15 to a core material 11 after frictionally heating the joining end portions 16 to 19 by rotating the shaft materials 14, 15 while pressing to the core material 11, and a manufacturing apparatus including first and second holding means 29, 23 for the roll barrel member 13 and the shaft materials 14, 15, a rotating means rotating the shaft materials 14, 15, a pressing means 24 pressing the core material 11 and the shaft materials 14, 15 in an axial direction, and a preheating means 31 preheating the joining end portions 16 to 19 of the roll barrel member 13 and the shaft materials 14, 15.

Abstract: A fixing device may include an endless fixing member; a heating unit that is provided inside an inner peripheral surface of the fixing member; and a nip forming unit that comes into press-contact with a rotationally driven pressing member with the fixing member interposed therebetween to form a nip. The nip forming unit has a shape in which a center of a contact surface protrudes toward the pressing member compared to both ends. The nip forming unit has a protruding amount at a center toward the pressing member compared to both ends of the nip forming unit in no-load state is set to be less than a bent amount of the nip forming unit when the nip forming unit comes into press-contact with the pressing member with the fixing member interposed therebetween.

Abstract: A fixing device includes a fixing rotator and a heater disposed inside the fixing rotator to heat the fixing rotator with radiant heat. A pressure rotator presses against the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator. A reflector is disposed opposite the heater to reflect the radiant heat radiated from the heater to the fixing rotator. The reflector includes a first parallel plane, a second parallel plane, and a third tilt plane. The second parallel plane is parallel to the first parallel plane and stepped with respect to the first parallel plane. The second parallel plane is disposed closer to the fixing nip and the heater than the first parallel plane. The third tilt plane bridges the first parallel plane and the second parallel plane and is disposed opposite the heater.

Abstract: A fixing device includes a fixing rotator, a first heat generator and a second heat generator that heat the fixing rotator, and a support disposed inside the fixing rotator. A reflector, interposed between the support and each of the first heat generator and the second heat generator, reflects light radiated from the first heat generator and the second heat generator toward the fixing rotator. The reflector includes a body mounted on the support and a shield portion projecting from the body toward the first heat generator and the second heat generator to shield the fixing rotator from the first heat generator and the second heat generator. An electric circuit is connected to the first heat generator and the second heat generator. A heat generation restrainer is provided in the electric circuit to restrict heat generation in the electric circuit.

Abstract: A fixing device includes a fixing rotator rotatable in a predetermined direction of rotation and a nip formation pad disposed inside the fixing rotator. A pressure rotator presses against the nip formation pad via the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator. A heat generator is disposed inside the fixing rotator to heat the fixing rotator. A reflector is interposed between the heat generator and the nip formation pad. The reflector includes a reflection face to reflect radiant heat radiated from the heat generator. The reflection face includes a reflection portion disposed opposite the heat generator at various angles. A support is provided separately from the nip formation pad and supports the reflector.

Abstract: A fixing device for fixing an unfixed image onto a recording medium includes a fixing belt, a nip forming member, an opposing rotary member, a heater, and a temperature detector. The fixing belt is formed into a loop to move endlessly and fix the unfixed image on the recording medium. The nip forming member is disposed inside the loop formed by the fixing belt. The opposing rotary member contacts the nip forming member via the fixing belt to form a nip portion therebetween while rotating. The heater heats the fixing belt at a place other than the nip portion. The temperature detector detects a temperature of the surface of the fixing belt. The temperature detector detects the temperature near a place of the fixing belt that easily deforms as the fixing belt is heated by the heater.

Abstract: A fixing device to fix a toner image on a sheet includes a first rotary member that rotates in a predetermined direction and a second rotary member that contacts an outer circumferential surface of the first rotary member. A stationary member is fixed inside the first rotary member to press the first and second rotary members together to form a nip portion between the rotary members. A reinforcement member is fixedly provided inside the first rotary member and pressed against the stationary member. The fixing device includes heat source to heat the first rotary member and a reflector to reflect heater light emitted from the heat source toward the first rotary member.

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: An image forming apparatus includes a first heater disposed opposite and heating at least a center of a fixing belt in an axial direction thereof and a second heater disposed opposite and heating at least a lateral end of the fixing belt in the axial direction thereof. A power supply supplies power to the first heater and the second heater. A controller that controls the power supply includes a calculator to calculate an elapsed time elapsed after at least one of the first heater and the second heater starts heating the fixing belt. The controller controls the power supply to supply power to the first heater and the second heater such that a power density of the second heater is greater than a power density of the first heater when the elapsed time calculated by the calculator is smaller than a predetermined time.

Abstract: A fixing device including a fixing member, an opposing member, a plurality of heat sources, and a voltage detector. The opposing member is disposed opposite the fixing member to contact the fixing member to form a nip portion at which an unfixed image on a recording medium is fixed. The plurality of heat sources heats the fixing member. The voltage detector detects an applied voltage of at least one of the plurality of heat sources. Upon detection of the applied voltage of the heat sources by the voltage detector, a voltage is applied to at least one of the heat sources.

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 nip formation pad to press against a fixing rotator. A primary heater is disposed opposite the fixing rotator in a primary heating span spanning in an axial direction of the fixing rotator to heat the primary heating span of the fixing rotator from which heat is conducted to the nip formation pad with a primary conduction. A secondary heater is disposed opposite the fixing rotator in a secondary heating span that is outboard from the primary heating span in the axial direction of the fixing rotator. The secondary heater is interposed between a first nip formation portion and a second nip formation portion of the nip formation pad to heat the secondary heating span of the fixing rotator through the nip formation pad from which heat is conducted to the fixing rotator with a secondary conduction greater than the primary conduction.

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: An image forming apparatus includes a first heater disposed opposite and heating at least a center of a fixing belt in an axial direction thereof and a second heater disposed opposite and heating at least a lateral end of the fixing belt in the axial direction thereof. A power supply supplies power to the first heater and the second heater. A controller that controls the power supply includes a calculator to calculate an elapsed time elapsed after at least one of the first heater and the second heater starts heating the fixing belt. The controller controls the power supply to supply power to the first heater and the second heater such that a power density of the second heater is greater than a power density of the first heater when the elapsed time calculated by the calculator is smaller than a predetermined time.