Abstract: A fixing device includes an endless belt, a first radiant heater including a first heat generator to heat the endless belt, and a second radiant heater including a second heat generator, disposed outboard from the first heat generator in an axial direction of the endless belt, to heat the endless belt. A nip formation pad includes a nip-side face disposed opposite the endless belt. A contact heater heats at least one lateral end of the endless belt in the axial direction of the endless belt. The contact heater includes a nip-side face disposed opposite the endless belt. A thermal conduction aid covers the nip-side face of the nip formation pad and the nip-side face of the contact heater and conducts heat applied to the endless belt in the axial direction of the endless belt.

Abstract: A fixing device includes an endless belt, a nip formation pad disposed inside a loop formed by the endless belt, and a radiant heater to heat the endless belt. A contact heater is disposed at least at one lateral end of the nip formation pad in a longitudinal direction of the nip formation pad. The contact heater includes a heat generator to heat at least one lateral end of the endless belt in an axial direction of the endless belt. A thermal conduction aid, covering a nip-side face of the nip formation pad and a nip-side face of the contact heater, conducts heat applied to the endless belt in the axial direction of the endless belt. The thermal conduction aid includes a heater-side face being disposed opposite the contact heater and covering at least the heat generator of the contact heater.

Abstract: A fixing device includes a flexible endless belt formed into a loop and having an inner circumferential surface, a heater to heat the endless belt, and a nip formation assembly disposed inside the loop formed by the endless belt. The nip formation assembly includes a pressure pad made of heat-resistant resin including a hollow filler, and a supplementary thermal conductor having a belt sliding-contact face over which the inner circumferential surface of the endless belt slides. The supplementary thermal conductor is interposed between the endless belt and the pressure pad to conduct heat from the heater in an axial direction of the endless belt. The fixing device further includes a pressure rotator to press against the nip formation assembly 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.

Abstract: A fixing device includes an endless belt formed into a loop, a heater to heat the endless belt, a nip formation assembly disposed inside the loop, and a pressure rotator to press against the nip formation assembly to form a fixing nip between the endless belt and the pressure rotator. The nip formation assembly includes a pressure pad and a supplementary thermal conductor to conduct heat from the heater in an axial direction of the endless belt. The supplementary thermal conductor has an edge portion dimensioned to distance the supplementary thermal conductor from the endless belt at an end portion of a face over which the endless belt slides in a longitudinal direction of the supplementary thermal conductor. A distance between the edge portion of the supplementary thermal conductor and the endless belt increases toward an end portion of the endless belt in the axial direction thereof.

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 rotatable in a predetermined direction of rotation and an opposed rotator disposed opposite the fixing rotator to form a fixing nip therebetween through which a recording medium bearing a toner image is conveyed. A heater is disposed opposite the fixing rotator to heat the fixing rotator. A nip formation pad is disposed opposite an inner circumferential surface of the fixing rotator. The nip formation pad includes a base, a first thermal conductor sandwiched between the base and the fixing rotator and having a first thermal conductivity greater than a thermal conductivity of the base, and a bulge projecting from the first thermal conductor toward the opposed rotator at a downstream end of the first thermal conductor in a recording medium conveyance direction.

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 nip formation assembly disposed opposite an opposed rotator via an endless belt includes a nip formation pad to press against the opposed rotator via the endless belt to form a fixing nip between the endless belt and the opposed rotator, through which a recording medium bearing a toner image is conveyed. A fixing heater is disposed opposite at least a center span of the endless belt in an axial direction thereof where the recording medium is conveyed. The fixing heater heats the endless belt. A lateral end heater is mounted on the nip formation pad and disposed opposite a lateral end span of an inner circumferential surface of the endless belt in the axial direction thereof. The lateral end heater heats the endless belt.

Abstract: In a conventional current resonance switching power source, the burst period of a burst operation could not be sufficiently prolonged, and the efficiency characteristics were insufficient in a light load. In order to improve this, an embodiment of the present invention generates, upon operating in the burst mode, a control signal in accordance with a comparison result of a first reference voltage and a secondary side voltage of a transformer and a comparison result of a second reference voltage and the secondary side voltage of the transformer. Subsequently, the oscillation operation timing of an oscillator that performs an oscillation operation to the transformer and the oscillation frequency that changes the voltage excited on the secondary side of the transformer are controlled based on the control signal.

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 fixing device includes: a fixing member that is rotatable and in an endless shape; a heat source that heats the fixing member; a nip forming member that is arranged inside the fixing member; and a pressurizing member that is pressurized to be in contact with the nip forming member through the fixing member, to form a fixing nip. The fixing device fixes an unfixed image on a recording medium by passing the recording medium that carries the unfixed image through the fixing nip. The nip forming member includes a base layer, and a high thermal-conductive layer that is arranged on a surface layer of the base layer on a fixing nip side, and that has higher thermal conductivity than the base layer, and in the high thermal-conductive layer, a low thermal-conductive portion is arranged near an end portion in an axial direction of the fixing member.

Abstract: A fixing device includes a fixing rotator and a pressure rotator pressed against a nip formation pad via the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator, through which a recording medium is conveyed. The nip formation pad includes an increased thermal conduction portion having an increased thermal conductivity and a decreased thermal conduction portion having a decreased thermal conductivity and being inboard from the increased thermal conduction portion in the axial direction of the fixing rotator. The increased thermal conduction portion is disposed opposite a non-conveyance span of the fixing rotator where the recording medium is not conveyed and includes an inboard edge inboard from a lateral edge of the recording medium toward a center of the recording medium in the axial direction of the fixing rotator by a predetermined first distance.

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 includes a fixing rotator, a nip formation pad disposed opposite an inner circumferential surface of the fixing rotator, and a pressure rotator pressed against the nip formation pad via the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator, through which a recording medium is conveyed. A support is disposed opposite the pressure rotator via the nip formation pad to support the nip formation pad against pressure from the pressure rotator. The nip formation pad conducts heat in a thickness direction thereof perpendicular to an axial direction of the fixing rotator and a recording medium conveyance direction. The nip formation pad includes a multi-conductivity layer having a thermal conductivity varying in the axial direction of the fixing rotator and a support side layer contacting the support and having a thermal conductivity greater than a thermal conductivity of the support.

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: 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 includes a first heater and a second heater disposed inside a fixing rotator to heat the fixing rotator. The first heater generates an increased amount of heat and includes a first heat generator having a first heating span in a longitudinal direction of the first heater. The second heater generates a decreased amount of heat and includes a second heat generator having a second heating span in a longitudinal direction of the second heater. A partition is interposed between the first heater and the second heater to define a first compartment having an increased size and accommodating the first heater and a second compartment having a decreased size and accommodating the second heater.