Abstract: A fixing device includes a fixing rotary body and a heater disposed opposite and heating the fixing rotary body. A nip formation assembly presses against an opposed body via the fixing rotary body to form a fixing nip between the fixing rotary body and the opposed body, through which a recording medium is conveyed. A movable heat shield movable in a circumferential direction of the fixing rotary body is interposed between the heater and the fixing rotary body to shield the fixing rotary body from the heater in a variable axial span of the fixing rotary body. A stationary heat shield, interposed between the heater and the fixing rotary body to shield the fixing rotary body from the heater, is disposed outboard from a lateral edge of a heat generator of the heater in an axial direction of the fixing rotary body.

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: When calculating an actual turn-on duty based on a required duty according to a feedback control, the actual turn-on duty is corrected using a correction table or a correction conversion formula such that a required turn-on duty and the actual turn-on duty coincide with each other. A fixing heater is controlled according to the corrected actual turn-on duty.

Abstract: A fixing device includes a fixing rotator heated by a heater and a pressing rotator pressed against the fixing rotator to form a fixing nip therebetween, through which a recording medium bearing a toner image is conveyed. A heat shield interposed between the heater and the fixing rotator is movable in a circumferential direction of the fixing rotator to shield the fixing rotator from the heater in a variable axial shield span of the fixing rotator. The fixing rotator performs fixing rotation to convey the recording medium through the fixing nip while heating the recording medium and supplemental rotation other than fixing rotation. The heat shield moves to a decreased shield span position where the heat shield shields the fixing rotator from the heater in a decreased axial shield span of the fixing rotator during supplemental rotation thereof.

Abstract: A fixing device includes a fixing rotary body and a heater disposed opposite the fixing rotary body. A heat shield is movable in a circumferential direction of the fixing rotary body and interposed between the heater and the fixing rotary body to shield the fixing rotary body from the heater. An overheating suppressor is interposed between the heater and the heat shield to shield the heat shield from the heater. The heat shield includes an intermediate portion spanning in the circumferential direction of the fixing rotary body and movable between a shield position where the intermediate portion is disposed opposite the heater directly and a retracted position where the intermediate portion is disposed opposite the heater via the overheating suppressor.

Abstract: A fixing device capable of shifting to a sleep state includes a heat source; a rotatable fixing member that is partly heated by the heat source to heat an unfixed image carrying surface of a recording medium; a rotatable pressing member that is in pressure contact with the fixing member to form a nip portion between the pressing member and the fixing member; a rotation drive unit that directly or indirectly rotates the fixing member; a temperature detecting unit that detects a temperature of the fixing member; and a controller configured to prohibit the fixing device from shifting to the sleep state when the temperature of the fixing member in a region facing the heat source is equal to or more than a predetermined temperature T1 at a point when a predetermined time period t1 has elapsed from the stop of rotation drive of the rotation drive unit.

Abstract: A fixing device includes a support member disposed to support a nip formation member on an inner peripheral surface of a fixing belt. The support member includes a parallel portion that supports the nip formation member and extends parallel to a sheet transport direction in a nip portion, and a rise portion that extends from the parallel portion in a direction drawn apart from the nip portion. The rise portion is inclined to the parallel portion such that an inclination direction of the rise portion is substantially parallel to a virtual straight line connecting a center of rotation of the fixing belt and an inlet point of the nip portion or falls within a range of rotational angles of ±15° by which the virtual straight line is rotated around the center of rotation of the fixing belt.

Abstract: A fixing device includes an elastic rotator and a cooler disposed opposite the rotator to cool the rotator with cooling air. A mover contacts and moves the rotator to a first position where the rotator is disposed opposite the cooler with an increased first interval therebetween and a second position where the rotator is disposed opposite the cooler with a decreased second interval therebetween. A rectification plate is movably mounted on the cooler to contact the rotator constantly to guide the cooling air to the cooler.

Abstract: A fixing device includes a first roller contacting a fixing belt to generate a rotation friction force therebetween to rotate the fixing belt and a second roller contacting the fixing belt to exert a first inhibition force to the fixing belt in a direction opposite a direction of rotation of the fixing belt. A separation aid is disposed downstream from a fixing nip formed between the fixing belt and a pressure rotator in the direction of rotation of the fixing belt to decrease a curvature of the fixing belt and exert a second inhibition force to the fixing belt in the direction opposite the direction of rotation of the fixing belt. The second inhibition force is added to the first inhibition force to obtain a combined inhibition force that is smaller than the rotation friction force between the fixing belt and the first roller.

Abstract: A fixing device includes a fixing belt stretched taut across a fixing rotator and a support rotator. A pressure rotator is pressed against the fixing rotator via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium bearing a toner image is conveyed. The pressure rotator includes a recess defining an outer diameter of each lateral end of the pressure rotator in an axial direction thereof that is greater than an outer diameter of a center of the pressure rotator in the axial direction thereof A first separator is disposed downstream from the fixing nip in a recording medium conveyance direction and contacts an inner circumferential surface of the fixing belt. The first separator is isolated from the pressure rotator and includes a projection disposed opposite the recess of the pressure rotator.

Abstract: A fixing device includes a fixing rotator rotatable in a predetermined direction of rotation and a nip formation assembly contacting an inner circumferential surface of the fixing rotator. An opposed rotator presses against the nip formation assembly via the fixing rotator to form a fixing nip between the fixing rotator and the opposed rotator, through which a recording medium is conveyed. A support, disposed opposite the inner circumferential surface of the fixing rotator, supports the nip formation assembly. A heater, disposed opposite the inner circumferential surface of the fixing rotator, heats the fixing rotator. A reflector, disposed opposite an outer circumferential surface of the fixing rotator, reflects heat radiated from the fixing rotator onto the fixing rotator. The reflector spans a circumferential span of the fixing rotator where the fixing rotator is spaced apart from the support with a decreased interval therebetween.

Abstract: According to an embodiment, provided is a fixing device that includes: a rotatable fixing member that heats a recording medium on a side carrying an unfixed image; a rotatable pressing member that is pressed and is contacted with the fixing member to form a nip portion between the pressing member and the fixing member; a heat source heating the fixing member; a relay switch provided in an energizing path for the heat source; a temperature detection sensor detecting a temperature of the fixing member; and a control unit that controls energization of the heat source according to the temperature detected by the temperature detection sensor. The control unit keeps the relay switch in an off state if the temperature of the fixing member is equal to or more than a predetermined temperature when the fixing member has stopped rotation.

Abstract: A fixing device capable of shifting to a sleep state includes a heat source; a rotatable fixing member that is partly heated by the heat source to heat an unfixed image carrying surface of a recording medium; a rotatable pressing member that is in pressure contact with the fixing member to form a nip portion between the pressing member and the fixing member; a rotation drive unit that directly or indirectly rotates the fixing member; a temperature detecting unit that detects a temperature of the fixing member; and a controller configured to prohibit the fixing device from shifting to the sleep state when the temperature of the fixing member in a region facing the heat source is equal to or more than a predetermined temperature T1 at a point when a predetermined time period t1 has elapsed from the stop of rotation drive of the rotation drive unit.

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: 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: In the present invention, upon return from a standby mode or sleep mode, image data is acquired as warming-up time estimate information for estimating the warming-up time to increase the temperature of a fixing belt to a target fixing temperature and, if the acquired image data is the data on a black-and-white image, control is performed to delay the heating start timing of the fixing belt.

Abstract: In an embodiment, provided is a fixing device that includes: a fixing belt rotatable and endless; a belt holding member holding the fixing belt at each end part in an axial direction; a heat source heating the fixing belt; a nip forming member provided inside the fixing belt; an opposing rotator forming a nip portion between the opposing rotator and the fixing belt via the fixing belt; and a separating member that extends near the nip portion and separates a recording medium from a surface of the fixing belt. A leading end of the separating member is provided with a receding portion and an approaching portion that is at a different position from a position of the receding portion different in the axial direction. The approaching portion is provided nearer to the nip portion than the receding portion is provided.

Abstract: A fixing device includes an endless flexible belt, an elongated stationary pad, a rotary pressure member, and a low-friction sheet. The endless flexible belt is looped into a generally cylindrical configuration extending in an axial direction thereof for rotation in a rotational, circumferential direction thereof. The elongated stationary pad is stationarily disposed inside the loop of the belt. The rotary pressure member is disposed parallel to the belt. The rotary pressure member presses against the stationary pad via the belt to form a nip therebetween, through which a recording medium is conveyed in a conveyance direction. The low-friction sheet of lubricant-impregnated material covers the stationary pad to supply a lubricant between the stationary pad and the belt across the nip. The low-friction sheet has one or more flow channels defined therein.

Abstract: A fixing device includes at least one heater disposed opposite an inner circumferential surface of an endless rotary body to heat the endless rotary body and a shield interposed between the endless rotary body and the at least one heater to shield the endless rotary body from heat radiated from the at least one heater. A first size recording medium passes over a first passage region of the endless rotary body and a second size recording medium passes over a second passage region of the endless rotary body. The shield includes a notch disposed opposite a lateral end of the second passage region of the endless rotary body in an axial direction thereof. The lateral end of the second passage region overlaps a non-passage region of the endless rotary body in the axial direction thereof where the first size recording medium does not pass.

Abstract: A fixing device includes a rotary endless fixing belt; a nip forming member disposed in an interior of the fixing belt; a rotary opposed member to contact the nip forming member via the fixing belt to form a nip together with the fixing belt; a heat source to directly heat the fixing belt at a portion other than the nip, including at lease one heat-generation part disposed outside lateral ends of a maximum area of the fixing belt where a recording medium passes through, wherein a recording medium carrying an unfixed image is conveyed to the nip and the fixing device fixes the unfixed image onto the recording medium; and a shielding member disposed between the fixing belt and the heat generation part of the heat source and configured to shield heat from the heat source at least at an area outside the maximum passing area of the recording medium.