Abstract: A heating device includes a belt, a heater that is in contact with an inner surface of the belt and divided into heater blocks in a width direction thereof, a pressing member that presses a sheet against the belt, a temperature sensor disposed on each of a number of the heater blocks that is at least one-half of the total number thereof, and a processor configured to select one or more of the heater blocks based on a width of the sheet, and select one or more temperature sensors disposed on one or more of the selected heater blocks having the non-paper passing region and control electric power supplied to said one or more of the selected heater blocks to protect against an excessive temperature rise in the non-paper passing region based on temperatures detected by the temperature sensors.

Abstract: A heating device includes a cylindrical film, a heater arranged inside the cylindrical film and extending along a longitudinal direction of the cylindrical film, a heat conductor extending along the longitudinal direction, and a first grease layer between the heater and the heat conductor and having a consistency grade less than or equal to three.

Abstract: A fixing belt and a fixing device suppress charging of the fixing belt and permit securing of a withstand voltage of secondary parts of the fixing belt are provided in addition to a heater. The fixing belt is formed of a tubular endless fixing film including, in order from an inner peripheral side of the film, a base layer, an elastic layer, and a release layer. A surface resistivity of the fixing belt measured from the base layer side is 7 [LOG ?/sq.] or more and 10 [LOG ?/sq.] or less.

Abstract: An image forming apparatus includes a fixing device and a processor. The fixing device has a heat generating element, a fixing belt which moves along a surface of the heat generating element while an inner peripheral surface of the fixing belt makes contact with the heat generating element, a rotatable body configured to be pressed against an outer peripheral surface of the fixing belt, and a lubricant which is applied to and in contact with the inner peripheral surface of the fixing belt. The processor is configured to acquire a physical quantity which changes in accordance with a magnitude of a torque that is applied to rotate the rotatable body, and cause the rotatable body to execute a predetermined operation to adjust a gap between the heat generating element and the fixing belt, based on the physical quantity acquired while the fixing device is carrying out image formation.

Abstract: According to one embodiment, a fixing device includes a belt, a heater, and a holder. The belt is formed into a cylindrical shape, is rotated in a circumferential direction to transport a sheet, and applies heat to the sheet. The heater is arranged on an inner side of the belt and extends in a predetermined longitudinal direction to heat the belt. The holder extends in the longitudinal direction of the heater and holds the heater. The holder includes a support portion and a retraction portion. The support portion comes into contact with the heater and supports the heater. The retraction portion is provided at a position avoiding the support portion in the longitudinal direction of the heater, and includes a smaller contact area with the heater than the contact area between the support portion and the heater or does not come into contact with the heater.

Abstract: An image processing apparatus includes a fixing unit including a heater and a fixing belt. The fixing belt is electrically connected between a first power source and a ground terminal. A controller is configured to control the heater to heat the fixing belt. The controller is further configured to determine whether a current is flowing through the fixing belt and, upon determining that a current is not flowing through the fixing belt, control the heater not to heat the fixing belt.

Abstract: A heating device includes a belt, a heater that is in contact with an inner surface of the belt and divided into heater blocks in a width direction thereof, a pressing member that presses a sheet against the belt, a temperature sensor disposed on each of a number of the heater blocks that is at least one-half of the total number thereof, and a processor configured to select one or more of the heater blocks based on a width of the sheet, and select one or more temperature sensors disposed on one or more of the selected heater blocks having the non-paper passing region and control electric power supplied to said one or more of the selected heater blocks to protect against an excessive temperature rise in the non-paper passing region based on temperatures detected by the temperature sensors.

Abstract: A fixing unit or device that can be used in an image forming apparatus includes a first heater element that is formed of a material that increases in electrical resistance with increases in temperature. A controller of the fixing unit is configured to vary a duty ratio of electric power applied to the first heater element during a start-up operation in which the temperature of the first heater element is raised to a target operating temperature. By varying the duty ratio during the start-up operation, changes in the resistance of the first heater element with the heating can be compensated. For example, the duty ratio can be increased during the course of the start-up to achieve the target operating temperature faster.

Abstract: An image forming apparatus includes a heater, a fixing device, and a controller. The heater includes a heat generator that generates heat when the heater is turned on. The fixing device may fix a developer image on a surface of an image forming medium using the heat from the heat generator. The controller detects a voltage of a power supply for supplying electric power to the heater, and determines an occurrence of an abnormality in the heater if a voltage drop amount at the time the heater is turned on as compared to a case in which the heater is turned off is smaller than a first threshold value.

Abstract: An image processing apparatus includes a fixing unit including a heater and a fixing belt. The fixing belt is electrically connected between a first power source and a ground terminal. A controller is configured to control the heater to heat the fixing belt. The controller is further configured to determine whether a current is flowing through the fixing belt and, upon determining that a current is not flowing through the fixing belt, control the heater not to heat the fixing belt.

Abstract: A heating device includes a cylindrical film, a heater arranged inside the cylindrical film and extending along a longitudinal direction of the cylindrical film, a heat conductor extending along the longitudinal direction, and a first grease layer between the heater and the heat conductor and having a consistency grade less than or equal to three.

Abstract: A heating device includes a cylindrical film configured to be rotated about an axis, a heater including a substrate that extends along a longitudinal direction parallel to the axis, and a heater element on the substrate and facing an inner surface of the cylindrical film. A heat conductor extends along the longitudinal direction and has first and second surfaces. A first portion of the heat conductor contacts the substrate and a second portion of the heat conductor has a groove in the first surface. A temperature sensing element is disposed at a position on the second surface at a position opposite the groove.

Abstract: According to one embodiment, a fixing device includes a belt, a heater, and a holder. The belt is formed into a cylindrical shape, is rotated in a circumferential direction to transport a sheet, and applies heat to the sheet. The heater is arranged on an inner side of the belt and extends in a predetermined longitudinal direction to heat the belt. The holder extends in the longitudinal direction of the heater and holds the heater. The holder includes a support portion and a retraction portion. The support portion comes into contact with the heater and supports the heater. The retraction portion is provided at a position avoiding the support portion in the longitudinal direction of the heater, and includes a smaller contact area with the heater than the contact area between the support portion and the heater or does not come into contact with the heater.

Abstract: A heating device includes a belt, a heater that is in contact with an inner surface of the belt and divided into heater blocks in a width direction thereof, a pressing member that presses a sheet against the belt, a temperature sensor disposed on each of a number of the heater blocks that is at least one-half of the total number thereof, and a processor configured to select one or more of the heater blocks based on a width of the sheet, and select one or more temperature sensors disposed on one or more of the selected heater blocks having the non-paper passing region and control electric power supplied to said one or more of the selected heater blocks to protect against an excessive temperature rise in the non-paper passing region based on temperatures detected by the temperature sensors.

Abstract: A heating device includes an belt, a heater contacting the belt and divided into heater blocks, a pressing member pressing a sheet against the belt, a temperature sensor disposed on a number of the heater blocks being at least one-half of a total number of the blocks, and a processor configured to select heater blocks based on a width of the sheet, select first temperature sensors on the selected heater blocks not having a non-paper passing region and control electric power supplied to the heater blocks so that temperatures detected by the first sensors are within a predetermined range, and select second temperature sensors on the selected heater blocks having the non-paper passing region and control electric power supplied to the heater blocks having the non-paper passing region to protect against an excessive temperature rise in the non-paper passing region based on second temperatures detected by the second sensors.

Abstract: An image forming apparatus includes a fixing device and a processor. The fixing device has a heat generating element, a fixing belt which moves along a surface of the heat generating element while an inner peripheral surface of the fixing belt makes contact with the heat generating element, a rotatable body configured to be pressed against an outer peripheral surface of the fixing belt, and a lubricant which is applied to and in contact with the inner peripheral surface of the fixing belt. The processor is configured to acquire a physical quantity which changes in accordance with a magnitude of a torque that is applied to rotate the rotatable body, and cause the rotatable body to execute a predetermined operation to adjust a gap between the heat generating element and the fixing belt, based on the physical quantity acquired while the fixing device is carrying out image formation.

Abstract: A heating device includes an belt, a heater contacting the belt and divided into heater blocks, a pressing member pressing a sheet against the belt, a temperature sensor disposed on a number of the heater blocks being at least one-half of a total number of the blocks, and a processor configured to select heater blocks based on a width of the sheet, select first temperature sensors on the selected heater blocks not having a non-paper passing region and control electric power supplied to the heater blocks so that temperatures detected by the first sensors are within a predetermined range, and select second temperature sensors on the selected heater blocks having the non-paper passing region and control electric power supplied to the heater blocks having the non-paper passing region to protect against an excessive temperature rise in the non-paper passing region based on second temperatures detected by the second sensors.

Abstract: A fixing device includes an endless belt, a heater in contact with an inner surface of the belt and divided into a plurality of heater blocks in a width direction of the belt, a pressing member positioned to face the heater with the belt interposed therebetween and configured to press a conveyed sheet against the belt and the heater, a temperature sensor disposed in each of at least half of the heater blocks, and a processor. The processor selects heater blocks based on width and position of the conveyed sheet to form a heat generation block, controls power supplied to the heater blocks so that a temperature of the heat generation block is within a predetermined temperature range, and selects the temperature sensor disposed in a heater block having a non-paper passing region and control an excessive temperature rise in the non-paper passing region.

Abstract: According to one embodiment, a fixing device includes a belt, a heater, and a holder. The belt is formed into a cylindrical shape, is rotated in a circumferential direction to transport a sheet, and applies heat to the sheet. The heater is arranged on an inner side of the belt and extends in a predetermined longitudinal direction to heat the belt. The holder extends in the longitudinal direction of the heater and holds the heater. The holder includes a support portion and a retraction portion. The support portion comes into contact with the heater and supports the heater. The retraction portion is provided at a position avoiding the support portion in the longitudinal direction of the heater, and includes a smaller contact area with the heater than the contact area between the support portion and the heater or does not come into contact with the heater.

Abstract: According to one embodiment, a fuser includes a heat roller, an endless belt, a first press roller and a second press roller. The heat roller rotates and contacts a toner surface side of a sheet, and heats the sheet. The endless belt contacts a part of an outer peripheral surface of the heat roller. The first press roller contacts a part of an inner peripheral surface of the endless belt, and is provided at an insertion part of the sheet in a nip portion where the heat roller contacts the endless belt. The second press roller contacts a part of the inner peripheral surface of the endless belt, is provided at an exit part of the sheet in the nip portion, and has a lower rotational resistance than the first press roller.