Abstract: According to an embodiment, a fixing unit includes a heater, a fixing member, a press roller, a sensor, a processor, and a memory. The fixing member is heated by heat generated by the heater. The press roller forms a nip portion through which a medium having a fixing target material transferred thereto passes, between the press roller and the fixing member. The sensor measures a temperature of the fixing member. The processor controls the temperature of the fixing member so as to be a target value by acquiring the temperature detected by the sensor in a first period, and also acquires the temperature detected by the sensor in a second period shorter than the first period. The memory records the temperature acquired in the second period.

Abstract: A power supply apparatus includes a first circuit, a second circuit, a switcher configured to switch between a power supplied state and a power interrupted state, a driver configured to output a signal for switching the state of the switcher, an adjusting unit, a first control unit, a second control unit, a first communication portion, and a second communication portion. The first control unit is operated by power supplied by a signal generated in the first communication portion. The first control unit transmits, to the second communication portion, information about a detection result. The second control unit controls the adjusting unit based on the information. The first control unit outputs a predetermined signal for causing the driver to output the switching signal for putting the switcher into the interrupted state in a case where abnormality occurs. The driver outputs the switching signal for putting the switcher into the interrupted state based on the predetermined signal.

Abstract: In an image heating device having a plurality of heating blocks which are controllable independently in a longitudinal direction of a heater, an increase of the size of the heater can be suppressed, and temperatures of a plurality of heating block can be detected. A heater has a first temperature sensor corresponding to a first heating block, a second temperature sensor corresponding to a second heating block, a first electric conductor electrically coupled to the first temperature sensor, a second electric conductor electrically coupled to the second temperature sensor, and a common electric conductor electrically coupled to the first and second temperature sensors.

Abstract: A fixing device includes a heat generating member, an endless belt, and a heat conductive member that contacts the heat generating member in a first region. A positioning portion is provided at an end portion of the heat conductive member, so as to extend in a direction in which the positioning portion is spaced apart from the heat generating member. A supporting member is provided with a first opening at a position corresponding to a second region of the heat generating member, and supports the heat generating member via the heat conductive member. An electrical power shut-off member, located in the first opening of the supporting member, shuts off electrical power supplied to the heat generating member. The positioning portion is inserted into the first opening of the supporting member to prevent movement of the heat conductive member.

Abstract: A fixing device includes an elastic fixing roller, an endless belt, a pressing roller and a stretching part. The endless fixing belt is wound around the fixing roller with play. The pressing roller presses the fixing roller via the fixing belt to deform the fixing roller and forms a pressing area between the pressing roller and the fixing belt. A sheet passes through the pressing area. The stretching part is configured to pull the fixing belt in a direction opposite to the pressing roller and to stretch the fixing belt when a conveyance speed of the sheet conveyed to the pressing area is slower than a reference conveyance speed. The stretching part is configured to restrain deformation of the fixing roller to the pressing roller and to shorten length of the pressing area along a conveyance direction of the sheet.

Abstract: An image forming apparatus includes an image bearing drum; an exposing unit for exposing the drum; an electric circuit board provided substantially perpendicularly to an apparatus installing floor; a driving unit for supplying a driving force; a first metal plate supporting the exposing unit; a second metal plate supporting the electric circuit board; and a third metal plate supporting the driving unit. At least one of the first, second and third plates is provided at each of four sides of the apparatus, the four sides being substantially perpendicular to the floor. The first, second and third plates are electrically connected with each other.

Abstract: Provided is an inexpensive image forming apparatus that reduces wasteful operation and is capable of determining whether a fixing unit is attached properly. The image forming apparatus includes an image forming apparatus main body, and a fixing roller that fixes a pattern composed of toner on paper by heating when conveying the paper on which the pattern is formed, and uses a fixing unit that can be attached to and detached from the image forming apparatus main body. A temperature sensor for detecting the temperature of the fixing roller is provided in the fixing unit. The image forming apparatus includes a control unit that, after the fixing unit is attached, determines whether or not the fixing unit is attached properly to the image forming apparatus main body according to a magnitude relationship between the temperature detected by the temperature sensor and a preset first threshold value.

Abstract: According to one embodiment, a fixing device includes a heat roller, a first heat generating body, a second heat generating body, and a power adjuster. The heat roller heats a conveyed sheet. The first heat generating body is provided in the heat roller and generates heat in the vicinity of the center in the length direction of the heat roller. The second heat generating body is provided in the heat roller and generates heat in the vicinities of both the ends in the length direction of the heat roller. The power adjuster applies thinning control to electric energy supplied to one or both of the first heat generating body and the second heat generating body.

Abstract: A fixing apparatus for fixing a toner image to a recording material includes a cylindrical film, a heater configured to make contact with the film, the heater including a substrate and a heat generation resistor formed on the substrate, and a heat conduction member configured to make contact with a surface of the heater opposite to a surface thereof being in contact with the film, the heat conduction member having a higher thermal conductivity than that of the substrate, and being divided into parts in a generatrix direction of the film. The toner image formed on the recording material is fixed on the recording material by using heat of the film, and one of the parts of the heat conduction member is configured to make contact with the heater continuously from a center to an end of a heat generation region of the heater in the generatrix direction.

Abstract: A system for operation of an induction stove includes an AC to DC voltage converter receiving AC voltage from a power input, a voltage sensing unit coupled to the converter and including an optocoupler, and a processor coupled to the sensing unit for receiving voltage information from the unit and controlling at least one of input voltage, input current, and oscillation frequency of a heating coil of the induction stove. A method for operating an induction stove includes converting an AC voltage from a power input to a DC voltage, supplying the DC voltage to a voltage sensing unit coupled to the converter and including an optocoupler, transmitting a voltage measurement from the sensing unit to a processor, and controlling at least one of an input voltage and oscillation frequency to a heating coil of the induction stove via the processor based at least in part on the voltage measurement.

Abstract: In a fixing device, a windbreak plate 908 for suppressing movement of air by a cooling fan 903 toward a thermistor 912 is provided. This windbreak plate 908 is, when a fixing roller 910 and a pressing roller 920 are spaced from each other, disposed opposed to the pressing roller 920 with a distance narrower than an opposing distance between an entrance guide 905 and the pressing roller 920.

Abstract: A control method of an image forming apparatus including a fixing device including a fixing rotator includes starting warming up the fixing device; detecting at least one of an electric voltage, an electric current, and an electric power input to the image forming apparatus when the fixing device is warmed up; detecting a temperature of the fixing rotator when the fixing device is warmed up; determining that the image forming apparatus is in a low input state that does not satisfy a predetermined input condition based on the detected one of the electric voltage, the electric current, and the electric power; determining that the fixing rotator is in a low temperature state that does not satisfy a predetermined heating condition based on the detected temperature of the fixing rotator; and issuing a notification that urges a recovery operation of the fixing device.

Abstract: A fixing device includes: a tubular member extending in an axial direction and supported so as to be rotatable; a heat-generating member extending in the axial direction and in contact with an area between one end and the other end of the tubular member, the heat-generating member generating heat to heat the tubular member by receiving voltage; a pressure member that presses, to an outer circumferential surface of the tubular member, a recording medium having a toner image transferred thereto; and an interrupting member disposed between another portion of the heat-generating member and the tubular member and extending in the axial direction, the interrupting member being in contact with an area between one end and the other end of the heat-generating member and interrupting the voltage applied to the heat-generating member when at least a portion in contact with the heat-generating member reaches or exceeds a threshold temperature.

Abstract: A fixing device includes a fixing belt, a belt guide, a pressuring member, a heat source and an excessive temperature rise preventing device. The guide contacts with the inside of the belt to assist the belt's rotation track. The heat source is located across the belt to the pressuring member to induction-heat the belt. The preventing device has first and second lead wires connected at one and another end sides in an axial direction of the belt and prevents excessive temperature rise of the guide in noncontact. The first lead wire is extended to one end side and pulled out from the inside to the outside via one end side in the belt. The second lead wire is extended to another end side, curved toward one end side, extended to one end side and pulled out from the inside to the outside via one end side in the belt.

Abstract: A frequency determining portion determines a driving frequency of an induction heater. A determination processing portion determines whether or not the driving frequency determined by the frequency determining portion is within a predetermined prohibited frequency band. A frequency changing portion, when the driving frequency determined by the frequency determining portion is within the prohibited frequency band and is lower than a predetermined threshold within the prohibited frequency band, changes the driving frequency to a frequency equal to or lower than a lower boundary frequency of the prohibited frequency band, and when the driving frequency is within the prohibited frequency band and is equal to or higher than the threshold, changes the driving frequency to a frequency equal to or higher than a higher boundary frequency of the prohibited frequency band. A heating control portion drives the induction heater by the driving frequency changed by the frequency changing portion.

Abstract: A rotation detection mechanism has a pulse plate, an optical sensor, a holder, and an input gear. The pulse plate has a light-blocking portion formed on an outer peripheral surface thereof. The optical sensor has a detection portion that detects whether an optical path thereof is opened or interrupted by the light-blocking portion of the pulse plate. The holder has a bearing hole that rotatably supports a rotary shaft of the pulse plate. The rotary shaft has a convex portion formed on an outer peripheral surface thereof and thus is in a key shape when seen from an axial direction thereof. On an inner peripheral surface of the bearing hole, a groove portion is formed through which the convex portion passes when the rotary shaft is inserted into the bearing hole, and the bearing hole is in a circular shape when seen from an axial direction thereof.

Abstract: A fixing device includes a magnetic flux generation unit, an auxiliary heating body formed of material that generates heat from the magnetic flux generated by the magnetic flux generation unit, a rotatable fixing belt having opposing first and second ends in a direction of its rotational axis and a material that generates heat from the magnetic flux, a magnetic flux shield in contact with the auxiliary heating body and having first and second openings that expose the auxiliary body, the first and second openings being symmetrical with respect to a center point along the rotational axis between the first and second ends, a temperature sensor in contact with the auxiliary heating body through one of the first and second openings of the magnetic flux shield shielding member, and a driver that controls power supplied to the magnetic flux generation unit in accordance with signals from the temperature sensor.

Abstract: An image forming apparatus includes an image forming unit, a heater, a heat receiving member configured to fix a toner image on a sheet, a first temperature sensor configured to sense a first temperature of the heat receiving member, a second temperature sensor configured to sense a second temperature of the heat receiving member, and a controller. The controller is configured to, after the image forming unit starts image formation: when a difference between the first temperature and the second temperature exceeds a threshold value a first number of times, perform a temperature reduction control in which the controller reduces a number of sheets to be printed per unit time and the image forming unit performs image formation for the reduced number of sheets to be printed per unit time; and increase the threshold value in accordance with a time elapsed.

Abstract: An image forming apparatus includes a heating roller, a temperature sensor, a controller, a signal wire, and a first resistor. The temperature sensor detects the temperature of a heating roller. The controller has a processor. The signal wire transmits a signal of the temperature sensor to the controller (input terminal). The first resistor is disposed between an output terminal of the controller and the signal wire. The controller includes a voltage application unit, a voltage detection unit, and a determination unit. The voltage application unit applies a voltage to the output terminal. The voltage detection unit detects a voltage value of the input terminal. The determination unit determines whether or not an abnormality occurs in the signal wire, on the basis of the voltage value detected by the voltage detection unit.

Abstract: Provided is a fixing apparatus for fixing a toner image on a recording material while conveying the recording material on which the toner image has been formed at a nip portion that includes a roller, a heating unit configured to heat the roller from outside the roller, the heating unit receiving power supplied from a power supply, a backup unit forming the nip portion with the roller, and a power shutdown member configured to operate in response to an abnormal temperature of the backup unit and shut down power supply to the heating unit.

Abstract: The present invention provides an apparatus having a part of a current detecting circuit configured to detect current to a heater in a fixing unit so that a main body of the image forming apparatus may have one configuration for 100 V and 200 V and provides an equal resolution of current detection for an apparatus for 100 V and an apparatus for 200 V.

Abstract: An image forming apparatus includes a fixing rotator and an opposed rotator pressed against the fixing rotator to form a fixing nip therebetween, through which a recording medium bearing a toner image is conveyed. A heater heats the fixing rotator. A temperature sensor contacts the opposed rotator to detect a temperature of the opposed rotator. A conveyor conveys the recording medium to the fixing nip. A driver drives the conveyor. A controller, operatively connected to the temperature sensor and the driver, controls the driver to drive the conveyor to convey the recording medium to the fixing nip based on the temperature of the opposed rotator detected by the temperature sensor. The controller causes the driver to be ready to drive the conveyor when a change in the detected temperature of the opposed rotator per unit time reaches a predetermined threshold.

Abstract: An image forming apparatus includes a charging device configured to uniformly charge a surface of a photoconductive element; an image writing device configured to write an image in the charged photoconductive element by light to form an electrostatic latent image; a developing device configured to visualize the formed electrostatic latent image as a toner image; a transfer device configured to transfer the toner image to a sheet recording medium; a fixing device configured to fix the transferred toner image onto the medium; and a surface information detecting device configured to detect surface information of a fixing member of the fixing device. The surface information detecting device radiates optical spots on a surface of the fixing member in a direction crossing a conveying direction, receives reflected light of each optical spot, and detects the surface information of the fixing device based on the detection results of the reflective lights.

Abstract: A fixing device includes a fixing belt, a pressuring member, a heat source, a pressing member, a temperature sensor and a controller. A detected region whose temperature is detected by the temperature sensor is formed in the fixing belt, and an elastic layer of the detected region is provided with a hole in a part thereof in a circumferential direction. The controller judges that the fixing belt is rotating in a case where the temperature detected by the temperature sensor alternately increases and decreases in a state that the heat source is heating the fixing belt, and judges that the fixing belt is not rotating in a case where the temperature detected by the temperature sensor does not alternately increase and decrease in the state that the heat source is heating the fixing belt.

Abstract: An image forming apparatus includes a developing device; a temperature detecting unit measuring a temperature of a main body; a cooling unit cooling the inside of the image forming apparatus; and a controller controlling the cooling unit based on result of the temperature detecting unit. The controller increases an air flow rate of the cooling unit such that the air flow rate is higher than a predetermined rate if the result of the temperature detecting unit is higher than a first temperature during non image forming and the controller increases an air flow rate of the cooling unit such that the air flow rate is higher than the predetermined rate if the result of the temperature detecting unit is higher than a second temperature which is higher than the first temperature during an image forming operation.

Abstract: A fixing device includes a fixing unit configured to fix an image on a sheet with heat when the sheet passes through a nip formed in the fixing unit, a temperature detection unit disposed adjacent to the fixing unit, and a control unit configured to change a maximum amount of power that is suppliable to the fixing unit from a first value to a second value that is smaller than the first value, based on a temperature detected by the temperature detection unit.

Abstract: A fixing device includes a fixing belt, a pressuring member, a heat source, a pressing member and a first heating stop device. The fixing belt is provided to be rotatable around a rotation axis. The pressuring member is configured to be rotatable and to come into pressure contact with the fixing belt so as to form a fixing nip. The heat source is arranged at an inner diameter side of the fixing belt, provided at a position displaced from the rotation axis and configured to heat the fixing belt. The pressing member is configured to press the fixing belt to a side of the pressuring member. The first heating stop device is configured to face an outer circumferential face of a closest part to the heat source of the fixing belt and to operate at a first operating temperature so as to stop the heat source from heating the fixing belt.

Abstract: A fixing device includes a fixing belt, a pressuring member, a heat source, a pressing member, a heating stop device, shape restricting members and biasing members. The fixing belt is provided to be rotatable around a rotation axis. The pressing member is provided to be rotatable and to come into pressure contact with the fixing belt so as to form a fixing nip. The heat source heats the fixing belt. The pressing member presses the fixing belt to a side of the pressuring member. The heating stop device faces an outer circumferential face of the fixing belt and to operate at an operating temperature so as to stop the heat source from heating the fixing belt. The shape restricting members are attached to both end parts of the fixing belt and restricts a shape of the fixing belt.

Abstract: An image forming apparatus, where, at suitable positions in a power supply path of a first heat generating member and a second heat generating member which can be switched to a series connection condition and a parallel connection condition, there are arranged a current detection section including a circuit which detects a current subjected to rectification of a positive half wave and a circuit which detects a current subjected to rectification of a negative half wave, and an applied voltage detection section including a circuit which detects a voltage subjected to full-wave rectification. Consequently, in the image forming apparatus which can be used in locations using different power supply voltages, failure of the apparatus can be detected, and reliability of the apparatus can be enhanced.

Abstract: An abnormality detection device for an image forming apparatus detects an abnormality in the image forming apparatus which includes a heating belt looped around a heating roller and a fixing roller. The abnormality detection device for an image forming apparatus includes: thermistors for detecting temperatures of one widthwise end portion and the other widthwise end portion of the heating belt; a temperature difference detection section for determining whether or not a temperature difference between the temperature of the one end portion and the temperature of the other end portion which are detected by the thermistors is greater than a predetermined value; and a judgment section for judging that an abnormality has occurred in the image forming apparatus when it is determined in the temperature difference detection section that the temperature difference is greater than the predetermined value.

Abstract: The present invention provides an apparatus having a part of a current detecting circuit configured to detect current to a heater in a fixing unit so that a main body of the image forming apparatus may have one configuration for 100 V and 200 V and provides an equal resolution of current detection for an apparatus for 100 V and an apparatus for 200 V.

Abstract: An image forming apparatus includes a heating element that generates heat, a temperature detector that detects a temperature of the heating element, a resistor that divides a detection result of the temperature detector and a predetermined reference voltage, a disconnection detector that detects a disconnection of the temperature detector, a converter that converts the divided voltage value into a digital signal and outputs the digital signal to a controller, a comparing unit that inverts its output on the basis of a predetermined threshold, a delay circuit that delays an increase in an output voltage of the comparing unit, a discharge circuit that quickly discharges the output voltage of the comparing unit, a latch circuit connected to an output of the discharge circuit, and a power supply path connecting and disconnecting unit that is connected to the latch circuit and connects and disconnects a power supply path to the heating element.

Abstract: An image forming apparatus includes a fixing portion for heating and fixing an unfixed image formed on a recording material, the fixing portion including a cylindrical film, a heater provided in an inside space of the film, a switch portion actuatable by heat from the heater, and a protection element for shutting off electric power supplied to the heater; a DC voltage source for generating a DC voltage from a commercial AC voltage source. The protection element is connected in a DC circuit operable by the DC voltage source, and when the switch portion is rendered off, the electric power supply to the heater is shut off.

Abstract: The image forming apparatus can be used in areas having different power supply voltages, in which a failure of the apparatus can be detected so that reliability of the apparatus is improved. The apparatus includes a connection state switching part which switches connection of a first heat generating member and a second heat generating member, which generate heat by electric power supplied from a commercial power supply through a power supply path, between a serial connection state and a parallel connection state, and a current detection part which detects current flowing in the power supply path. The current detection part is disposed in the power supply path after branching toward the first heat generating member and the second heat generating member in the parallel connection state.

Abstract: A fuser unit may include a cylindrical member, a heat generator, a nip member, and a backup member. A nip part may be defined between the cylindrical member and the backup member. The fuser unit may further include a conductive member, arranged to cover the heat generator at the inside of the cylindrical member, a temperature detection unit, a wiring, a first frame having insulation, arranged at an opposite side to the heat generator with respect to the conductive member being interposed therebetween at the inside of the cylindrical member, and which extends along the conductive member, and a second frame, arranged at an opposite side to the conductive member with respect to the first frame being interposed therebetween at the inside of the cylindrical member, and which extends along the first frame, wherein the wiring is arranged between the first frame and the second frame.

Abstract: A fuser assembly for an electrophotographic imaging device which removes excess heat from overheated portions of the fuser assembly and includes a heating member; a backup roll disposed proximate to the heating member so as to form a fuser nip therewith; and a heat exchange roll in contact with the backup roll such that rotation of the backup roll rotates the heat exchange roll, the heat exchange roll having an air passage for moving cooling air from one end to an opposite end of the heat exchange roll so as to provide cooling to the fuser assembly.

Abstract: An image forming apparatus includes an endless belt, a heater, a first temperature sensor, a second temperature sensor, and a controller. The endless belt has a center portion and end portions in an axial direction, and defines an internal space therein and an outer peripheral surface. The first temperature sensor is positioned at the center portion and facing the outer peripheral surface. The second temperature sensor is positioned at one of the end portions and in the internal space. The controller is configured to: receive a first signal from the first temperature sensor; control the heater based on the first signal; receive a second signal from the second temperature sensor; and determine whether an edge overheat occurs at the one of the end portions based on the second signal.

Abstract: The image heating apparatus heats a toner image beard on a recording material while conveying the recording material at a nip portion, and includes: a heater; a fixing member; a pressure member; a first temperature detecting member; a second temperature detecting member configured to detect a temperature on non-sheet-passing area; a control device; and an air supplying member supplying an air to the non-sheet-passing area. The air supplying member is started to be drive when a temperature detected by the second temperature detecting member reaches a predetermined temperature which is higher than the target temperature. The control device controls the quantity of the air in response to information related to the power supplied to the heater when a temperature detected by the second temperature detecting member reaches the predetermined temperature.

Abstract: An image forming apparatus includes a fixing unit having a heater and fixing a toner image formed on a recording material onto this recording material. The heater includes a first heat-generating member and a second heat-generating member, a first driving element provided on a power supply path to the first heat-generating member; a second driving element provided on a power supply path to the second heat-generating member, a control unit controlling the first driving element and the second driving element respectively, first detection unit for detecting current flowing through the first heat-generating member, a second detection unit of detecting current flowing through the second heat-generating member, and a safety circuit receiving a first output of the first detection unit and a second output of the second detection unit.

Abstract: A fixing device includes an endless belt, a nip member having a contact surface that is in contact with the inner surface of the endless belt, a backup member configured to pinch the endless belt in conjunction with the nip member, an upstream guide disposed upstream of the nip portion in the rotating direction, and a regulating portion. The upstream guide and the nip member are disposed while a first gap is provided, in a conveying direction of the recording sheet, between a middle portion of the upstream guide and a middle portion of the nip member. The regulating portion and one of the upstream guide and the nip member are disposed while a second gap is provided therebetween in the conveying direction of the recording sheet. The second gap is smaller than the first gap in the conveying direction of the recording sheet.

Abstract: An image forming apparatus includes a fixing roller to fix a toner on a recording medium; a heater to heat the fixing roller; an alternating current (AC) power source to generate an AC electric power such that the heater heats the fixing roller according to the AC electric power; a unit interposed between the heater and the AC power source to selectively supply the AC electric power from the AC power source to the heater so as to control the heater to heat the fixing roller; a relay including a first relay contact point disposed on a first AC power supply line between the AC power source and the unit and a relay coil to open and close the first relay contact point; the relay selectively supplying the AC electric power from AC power source to the heater and the power control switch; a direct current (DC) power supplier to supply a DC power to the relay coil; and a thermoswitch interposed on a DC power supply line between the DC power supplier and the relay coil to control the supply of the AC electric power fr

Abstract: An image forming apparatus and a control method thereof in which occurrence or removal of a paper rolling state in a fusing device is judged based on temperature of the fusing device. The apparatus includes a temperature sensor to sense temperature of the fusing device, a memory to store information about occurrence or removal of the paper rolling state, and a controller to judge occurrence or removal of the paper rolling state. The controller detects an initial temperature of the fusing device when the apparatus is turned off and then on in a state in which the information about occurrence of the paper rolling state is stored in the memory, heats the fusing device by applying power thereto for a predetermined time based on the initial temperature, and judges occurrence or removal of the paper rolling state based on temperature of the fusing device detected after power application.

Abstract: A fixing device includes a heating body; first and second coils for induction heating that heat the heating body by an induction heating method; a first switching element connected to the first coil for induction heating; a second switching element connected to the second coil for induction heating; a driving signal transmission unit that sends a first drive signal to the first switching element and a second drive signal to the second switching element so that the first switching element and the second switching element operate at the same timing to apply a first input voltage to the first coil for induction heating and a second input voltage to the second coil for induction heating; and a voltage drop unit that steps down the first input voltage applied to the first coil for induction heating so that the first input voltage is lower than the second input voltage.

Abstract: An image forming device including: an image forming unit; a heating body; a power supply unit; a temperature sensing member; and a controller. The image forming unit is configured to form an image on a recording sheet. The heating body is configured to heat the recording sheet on which the image is formed. The power supply unit is configured to supply power to the heating body. The temperature sensing member is configured to detect a temperature of the heating body. The controller is configured to: control the power supply unit based on the detected temperature; determine whether or not a high-power output state of the power supply unit has continued for a first duration under a print control process; and judge that the temperature sensing member is in an abnormal state when determination is made so that the high-power output state has continued for the first duration.

Abstract: A fixing device includes a heat roller, a fuser member, an endless belt, a pressure member, a first rotation transmitter, a second rotation transmitter, a rotation sensor, a controller, a first biasing member, and a second biasing member. The heat roller is rotatable around a rotational axis thereof while subjected to induction heating. The fuser member is disposed parallel to the heat roller. The endless belt is looped for rotation around the heat roller and the fuser member. The pressure member is disposed opposite the fuser member via the endless belt. The first rotation transmitter is connected to the rotational axis of the heat roller to rotate around a rotational axis thereof upon rotation of the heat roller. The second rotation transmitter engages the first rotation transmitter to rotate around a rotational axis thereof upon rotation of the first rotation transmitter.

Abstract: A method for determining abnormality of a temperature sensor and the image forming apparatus, the method comprises: detecting an actual temperature of a fixing apparatus and an input voltage; calculating an actual temperature variation amount in a predetermined time period; comparing the detected input voltage and a predetermined voltage; comparing the calculated actual temperature variation amount and a first reference temperature variation amount if the input voltage is greater than the predetermined voltage; determining that the temperature sensor is abnormal if the actual temperature variation amount is less than the first reference temperature variation amount; comparing the calculated actual temperature variation amount and a smaller second reference temperature variation amount if the input voltage is equal to or less than the predetermined voltage; determining that the temperature sensor is abnormal if the actual temperature variation amount is less than the second reference temperature variation amou

Abstract: An image forming apparatus includes a fixing unit, a power supply switch, a timer unit, a backup memory, and a controller. The backup memory is configured to nonvolatilely store an accumulated time, the accumulated time being a total period of time during which a heater is energized for detection of disconnection of a temperature-detecting unit after the power supply switch is turned on. The controller is configured to: recognize temperature of a heated member based on an output from the temperature-detecting unit, control the energization of the heater, and start the energization of the heater when the power supply switch is turned on. The controller is configured to determine that a disconnection of the temperature-detecting unit has occurred if the temperature recognized based on the output from the temperature-detecting unit remains in a predetermined low-temperature zone when the accumulated time has become a predetermined detecting-execution time period.

Abstract: A fixing device includes an endless belt that supplies heat to a medium, a heat diffusion member that stretches the endless belt, a heating body that heats the heat diffusion member, an overtemperature protector that is positioned to face the heating body; and a pressure application support member that is positioned between the heating body and the overtemperature protector.

Abstract: An image forming apparatus includes a fixing portion for heating and fixing an unfixed image formed on a recording material, the fixing portion including a cylindrical film, a heater provided in a cylindrical shape of the film, a switch portion actuatable by heat from the heater, and a protection element for shutting off electric power supplied to the heater; a DC voltage source for generating a DC voltage from commercial AC voltage source, wherein the protection element is disposed in the shape of cylinder of the film is connected in a DC circuit operable by the DC voltage source, and wherein when the switch portion is rendered off, the electric power supply to the heater is shut off.

Abstract: Provided is a fixing device including a transparent cylindrical body that is formed in a cylindrical shape to be rotatable, an opposing member that is arranged to oppose the transparent cylindrical body and forms a contact region in a portion between the transparent cylindrical body and the opposing member, a laser beam radiation device that is provided in an external portion of the transparent cylindrical body and radiates the laser beams, a light converging member that is provided in an internal portion of the transparent cylindrical body and is disposed to be in contact with portions of the transparent cylindrical body, and a liquid filling body that fills an air interface layer between a portion of the transparent cylindrical body and the light converging member, with a transparent liquid enabling the laser beams to pass therethrough.