Abstract: A recording medium is moved to a transfer printing station and print images are transfer-printed. The recording medium is transported to a fixing station. A print stop is initiated whereby the recording medium is halted, a further transfer printing is prevented, and a fixing is deactivated. It is checked whether a transfer-printed but unfixed page is still located in the printing apparatus. If so, a warning notification is automatically generated. A query is made as to whether an operating command has been input. If so, it is checked whether the unfixed page would also be output unfixed. If no, the operating command is executed. If yes, the print stop is automatically maintained. It is also inspected as to whether the unfixed page would be output upon execution of an additional operating command. If no, the additional operating command is executed. If yes, an error message is automatically generated.

Abstract: In a fixing apparatus, an internal temperature detection device is arranged within a heat generation region and detects temperature of a fixing device. An external temperature detection device is arranged at the outside of the heat generation region and detects temperature of the fixing device. Heat generation in the heat generating device is stopped when temperature reaches a prescribed first high temperature detection limit and a temperature rising amount in a prescribed time period after the first high temperature detection limit is reached exceeds a prescribed threshold.

Abstract: The fixing device includes: a fixing member including a conductive layer capable of self-heating by electromagnetic induction; a drive unit rotationally driving the fixing member; a magnetic field generating member generating an alternate-current magnetic field intersecting with the conductive layer; a fixation pressing member movable so as to come into pressure contact with an outer circumferential surface of the fixing member and to separate from the outer circumferential surface; and a temperature measurement unit that includes a temperature detector and a support portion, that measures temperature of the fixing member with the temperature detector which is pressed by the support portion to be brought into contact with an inner circumferential surface of the fixing member, and that holds a contact state between the temperature detector and the inner circumferential surface in every state where the fixing member is displaced in accordance with movement of the fixation pressing member.

Abstract: An image heating apparatus includes a coil for generating magnetic flux; a rotatable heater, having an electroconductive layer which generates heat by the magnetic flux, for heating an image on a recording material, the heater being disposed inside the coil; a magnetic member; a detector, disposed in an area between the magnetic member and an area of the heater opposing the coil, for detecting a temperature of the heater; an electric wire electrically connected to the detector; and an interruptor, for interrupting electric power supply to the coil on the basis of an output of the detector supplied through the electric wire. The magnetic member includes an opening through which the wire passes.

Abstract: The heating device includes plural heaters to heat fixing members; a power supplying device to supply power to the plural heaters; and a controller. The controller determines heater activation priority order for the heaters every control cycle, and allows the power supplying device to supply power to one of the heaters according to the heater activation priority order. When the controller judges that it is necessary to activate two or more of the heaters in a control cycle, the controller allows the power supplying device to supply power to one of the heaters having the highest rank in the heater activation priority order among the two or more of the heaters. The controller changes the heater activation priority order by according the lowest rank to the heater activated in the last control cycle while maintaining the rank relationship among the others of the heaters.

Abstract: An image forming apparatus forms an unfixed toner image on a sheet and includes a fixing unit including a fixing roller, a back-up member forming a nip with the fixing roller, and a rotatable heater contactable to and heating the fixing roller. The sheet is output from the apparatus after the unfixed toner image is fixed on the sheet. In a cleaning mode for cleaning the fixing unit, a predetermined unfixed toner image is formed on the sheet, the sheet is fed to the fixing unit, the toner is transferred from the sheet onto the fixing roller in the fixing nip, the toner transferred onto the fixing roller is brought into contact to the heating member, and thereafter, the toner on the fixing roller is transferred onto the sheet in the fixing nip.

Abstract: A sheet processing apparatus of the invention has: an ejecting unit that is capable of receiving a sheet on which a toner image has been heated and fixed, and ejecting the sheet for a predetermined normal ejecting time; and a processing unit that processes the sheet ejected by the ejecting unit according to obtained sheet information, wherein the ejecting unit ejects the sheet for an ejecting time longer than the normal ejecting time.

Abstract: An image forming apparatus that is capable of preventing an abnormal operation due to a voltage drop of a commercial power source and continuing an image forming operation efficiently even if the voltage drop occurs. A fixing unit fixes a toner image transferred onto a sheet. A voltage detection unit detects an input voltage of the commercial power source. A setting unit sets a fixing electric power supplied to the fixing unit from the commercial power source. A control unit suspends an operation when the set fixing electric power is less than a predetermined electric power and when the input voltage is less than a first voltage, and to continue the operation while reducing the set fixing electric power when the set fixing electric power is not less than the predetermined electric power and when the input voltage is less than a second voltage.

Abstract: A fuser unit includes: a cylindrical member; a heat generator; a nip member; a backup member, which configures a nip part between the cylindrical member and the backup member with the cylindrical member; a conductive member, which is arranged to cover the heat generator at the inside of the cylindrical member; a temperature detection unit; a wiring; a first frame having insulation, which is 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, which is 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 heat-responsive switch includes a case member, a deformation member deformed from a shape concave to an inside of the case member to a convex shape in response to a temperature variation, a first electrode having a first contact, a second electrode having a second contact and bringing the second contact into contact with the first contact with the first contact impelled to the deformation member, a first pressing member pressing the first electrode to separate the first contact from the second contact by having an end pressed by the deformation of the deformation member into the convex shape, and a second pressing member pressing the deformation member to restore the deformation member to the concave shape and pressing the second electrode to keep the first contact and the second contact separated by having the end pressed to the deformation member from an outside of the case member.

Abstract: A thermally-actuated switch includes a movable member that is provided between a second electrode and a displacement member so as to be movable in a first direction, is pushed at one end by the displacement member in a concave state to push the second electrode at the other end to bring a second contact into contact with a first contact, and is moved in the first direction by an urging force acting on the second electrode due to convex displacement of the displacement member, and a regulating member that regulates movement of the movable member in a second direction orthogonal to the first direction from a transmittable position where a pushing force from the displacement member is capable of being transmitted to the second electrode, and releases the regulation such that the movable member moved in the first direction by the urging force is removed from the transmittable position.

Abstract: An embodiment of the present invention includes a fixing member; a pressure member for pressing against the fixing member so as to form a nip region between the pressure member and the fixing member; a pressure cancellation unit for pressing the pressure member against the fixing member and for cancelling the state in which the pressure member is pressed against the fixing member; a paper detachment member for detaching paper held between the fixing member and the pressure member in the nip region from the pressure member; and a separation mechanism for cleaning the paper detachment member by separating the paper detachment member from the pressure member in conjunction with a pressure cancellation operation of the pressure cancellation unit.

Abstract: A thermal switch includes a body that includes a pair of electrodes and is inserted into an insertion hole formed at a mounting portion so as to be mounted on the mounting portion, a displacement member that is held on the body and displaced according to temperature change, a synchronization member that is provided at the body and separates one contact of the pair of electrodes from the other contact thereof in synchronism with the displacement of the displacement member, and regulating portions that are provided at the body and regulate the separation of the body from the insertion hole.

Abstract: A fixing device includes a fuser member, a pressure member, a positioning mechanism, an operational thermometer, an environmental sensor, and a controller. The fuser member is subjected to heating. The pressure member is opposite the fuser member. Thee fuser member and the pressure member press against each other to form a fixing nip therebetween through which a recording medium is passed. The positioning mechanism is coupled with the pressure member to move the pressure member into and away from contact with the fuser member. The operational thermometer adjoins the pressure member to detect an operational temperature at a surface of the pressure member. The environmental sensor is disposed in the image forming apparatus to detect an environmental condition. The controller is connected to the operational thermometer and the environmental sensor to control the positioning mechanism to adjust spacing between the fuser member and the pressure member.

Abstract: A heating device includes: a driving member configured to rotate; a driven member configured to rotate with the rotation of the driving member; a heater configured to heat a surface of one of the driving member and the driven member; a temperature detector configured to measure the temperature of the heated surface; and a controller operable to control heating of the heater based on the measurement result of the temperature detector. The controller includes: a calculator operable to calculate a change ratio of a slope of a temperature change of the heated surface with time, based on a first temperature detected by the temperature detector at a first time point and a second temperature detected by the temperature detector at a second time point a predetermined time interval after the first time point; and a determiner operable to determine that an abnormality occurs when the change ratio exceeds a threshold.

Abstract: A fixing device includes a protected object disposed opposite an outer circumferential surface of a pressing rotary body and upstream from a fixing nip formed between the pressing rotary body and a fixing rotary body in a direction of rotation of the pressing rotary body; a stationary duct disposed upstream from the protected object in the direction of rotation of the pressing rotary body, the stationary duct including a blowoff outlet disposed opposite the outer circumferential surface of the pressing rotary body through which airflow impinges on the outer circumferential surface of the pressing rotary body; and a shield interposed between the blowoff outlet of the stationary duct and the protected object in the direction of rotation of the pressing rotary body to protect the protected object against airflow from the blowoff outlet.

Abstract: A fixing device thermally fixes an unfixed image formed on a recording sheet that passes through a nip, the nip being formed by a pressing member pressing against a circumferential surface of a heating rotating body that includes a resistance heating layer. The fixing device includes a power supplier configured to supply power to the resistance heating layer, a driver configured to rotate the heating rotating body, a controller configured to control supply of the power by the power supplier, and an abnormal heat detector configured to detect whether abnormal heat occurs anywhere along an entire surface of a heat-producing region within the heating rotating body, detection being performed during rotation of the heating rotating body. The controller causes the power supplier to stop supplying power to the resistance heating layer when the abnormal heat detector detects abnormal heat.

Abstract: An image heating apparatus including: an image heating member for heating an image formed on a sheet at a nip portion; a temperature detector for detecting temperature of a predetermined region of the image heating member; a cooler for cooling the predetermined region; and an activating device for activating the cooler to perform a cooling operation in accordance with an output of the temperature detector, wherein the apparatus has a first mode of stopping a cooling operation in accordance with an output of the temperature detector; and a second mode of stopping the cooling operation in accordance with an end of image heating processing irrespective of the output of the temperature detecting device. The image heating apparatus is capable of suppressing unnecessary energy consumption, and of eliminating uneven glossiness due to a reduced temperature region at a boundary between a sheet passing portion and a non-sheet passing portion.

Abstract: A fixing device includes a fixing roller, a heating member, a pressure roller, a first temperature detecting element that detects a temperature of a contact region of the fixing roller that comes into contact with a paper, and a second temperature detecting element that detects a temperature of a noncontact region, and in which energization control of the heating member is carried out by the first one, and energization control is stopped when a temperature detected by the second reaches a prescribed temperature, the device including a conduction shutoff portion that, shuts off the energization where the temperature of the contact region has reached an upper limit, wherein, in which a center of the paper in an axial direction of the fixing roller has been aligned with a reference position of the fixing roller, the paper is transported, and the first one and the shutoff portion are placed symmetrically.

Abstract: A fixing device includes a fixing roller, a pressure roller and a soaking roller. Temperature of the soaking roller, which contacts with the pressure roller, is measured by a temperature measurement section. This makes it possible to precisely estimate the temperature distribution of the fixing roller and the pressure roller including a non-paper feed area of paper sheets. Based on the temperature of the soaking roller, fixing operation is controlled by a fixing operation control section. Thereby, optimal control can be implemented to suppress the temperature rise in the non-paper feed area according to the estimated temperature distribution of the fixing roller and the pressure roller.

Abstract: Damages on fixing members caused by paper passing through can be reduced. The registration rollers 53 and the registration oscillation roller 54 are provided on an upstream side of a fixing nip portion in a conveyance path for paper P and have a function of moving the paper P being conveyed toward the fixing nip portion, in a paper width direction, and the control section 10 performs paper oscillation control and fixing unit oscillation control in correlation with each other, the paper oscillation control in which the registration rollers 53 and the registration oscillation roller 54 are controlled to oscillate a position on which the paper P passes through, and the fixing unit oscillation control in which the fixing unit oscillation motor 36 is controlled to oscillate the fixing unit.

Abstract: An apparatus and method of protecting a fuser unit and an image forming apparatus having the same include a fuser drive motor portion to drive the fuser unit, a power detecting portion to detect power that is supplied to the fuser unit, and a power cutoff portion to cut off the power supplied to the fuser unit when a motor rotation signal is not output from the fuse drive motor portion and the power detecting portion detects the power that is supplied to the fuser unit. The fuser unit protecting apparatus and method and the image forming apparatus including the fuser unit protecting apparatus are configured to detect rotation of a fuser drive motor and supply of an alternating current required for a temperature rise and cut off the power supply when abnormal conditions occur, to prevent a continuous rise in a temperature of the fuser unit as well as deformation thereof.

Abstract: An image forming apparatus forms an image by fixing, on a recording medium, a toner image formed by an image forming unit. The image forming apparatus includes a determination unit which determines whether a delay has occurred during conveyance of a recording medium, based on the detection result of the recording medium discharged from a fixing unit for fixing a toner image on the recording medium, and a control unit which controls the operation of the image forming apparatus based on the determination result of the determination unit and a determination result indicating whether a jam processing operation was executed for the fixing unit.

Abstract: A fixing device comprises a rotatable endless flexible belt, a drive roller opposed to the rotatable endless flexible belt to contact and drive an outer circumferential surface of the rotatable endless flexible belt, and a nip formation device receiving pressure from the drive roller via the rotatable endless flexible belt to form a nip thereon to sandwich and convey a recording sheet. A heat source is provided to generate heat and heat the nip. Each of the end roller portions of the drive roller has a higher friction coefficient surface than a central roller portion of the drive roller sandwiching the recording sheet. These end roller portions are composed of separate bodies from the central roller portion and detachably attachable from and to the central roller portion.

Abstract: The image heating apparatus has a plurality of heat generators which are capable of forming a plurality of heat generating distributions in the longitudinal direction for supplying heat to a heating member. Unevenness in temperature is decreased by changing the heat generating distribution when cooling by a fan for the heating member starts. The heat generating distribution is changed so that heat generating amount at an area in the longitudinal direction corresponding to the cooling area cooled by the fan is to be larger than the heat generating amount before starting the cooling.

Abstract: A control portion determines whether a malfunction occurs or not in a roller temperature sensor and an ambient temperature sensor by comparing a trajectory (temporal behavior) actually created by two-dimensional data on a temperature table with a target trajectory. In other words, the control portion successively integrates a prescribed weight for each transition from one element to the adjacent element corresponding to a trajectory of two-dimensional data on the temperature table, and determines whether or not a malfunction occurs in the roller temperature sensor and the ambient temperature sensor, based on the integrated weight.

Abstract: In a fixing device, when sheets of small width size are continuously passed and temperature rises in both side parts, a temperature control unit stops print control of an auxiliary lamp. When the temperature rise in both side parts continues after that, a drive control unit shifts the fixing device to a wait mode and pre-runs the fixing device. Moreover, in a low-temperature environment, when temperature rises in both side parts when sheets Ps of small width size are continuously passed, the temperature control unit switches temperature control of the fixing device to three-stage control.

Abstract: The present invention provides a low-cost and safe image forming apparatus that has a first state in which first and second resistance heating bodies of a heater are connected in series, a second state in which the first and second resistance heating bodies are connected in parallel, and a third state in which a first switching unit shuts off a power supply path and a second switching unit is connected to a first power source terminal to block power supply to the heater.

Abstract: An apparatus is capable of switching between a mode in which a first resistance heating element and a second resistance heating element are connected in series and a mode in which they are connected in parallel. When a temperature increase rate detected by a temperature detection unit is smaller than a threshold rate although a current detected by a current detection unit is greater than a threshold current, a notification of a failure is issued.

Abstract: A fixing apparatus including a rotation detection circuit which detects the rotation state of the rotating member or pressing member, and one to (N?1) limiting circuits which limit driving of one to (N?1) driving circuits in accordance with an output from the rotation detection circuit, wherein when the rotation detection circuit detects that the rotating member or pressing member is not rotating, the one to (N?1) limiting circuits limit driving of the one to (N?1) driving circuits in accordance with the output from the rotation detection circuit to suppress energization of the heating elements regardless of the driving signals from the control unit to the driving circuits.

Abstract: Disclosed are an image forming apparatus and a fixing unit control method thereof, the image forming apparatus including an image forming unit, a fixing unit, a power supply to supply operating power to the fixing unit, a temperature sensor to sense a temperature of the fixing unit, a first protection unit to compare the sensed result of the temperature sensor with a first predetermined reference value and to output a signal, a switching unit to turn on/off power supplied to the fixing unit in accordance with the signal output from the first protection unit, a second protection unit to compare the sensed result of the temperature sensor with a second predetermined reference value and to output a signal, and a relay unit to turn on/off the operating power supplied to the fixing unit in accordance with the signal output from the second protection unit.

Abstract: The present invention provides a fixing apparatus including: a pair of rotating bodies that transports a recording medium on which an image is formed by using an image forming material, by sandwiching the recording medium; a heating section that heats at least one of the pair of rotating bodies; a moving section that moves the pair of rotating bodies between a position at which they mutually contact and a position at which they are mutually separated; a temperature detecting section that detects a surface temperature of at least one of the pair of rotating bodies without contacting the rotating bodies; and a twine generation determining section that determines whether the recording medium has twined around either one of the pair of rotating bodies based on a rate of temperature increase after a temperature decrease of the surface temperature detected by the temperature detecting section.

Abstract: A fixing device includes a heater, first and second pressure-applying members, a belt support member, a fixing belt, a contact member and a temperature detector. The fixing belt is entrained about the heater, the first pressure-applying member and the belt support member. The second pressure-applying member opposes the first pressure-applying member through the fixing belt. The contact member, which extends in the width direction of the fixing belt, is in contact with an inner surface of the fixing belt. The temperature detector, which is disposed between the belt support member and the contact member, detects a temperature of the fixing belt through the contact member.

Abstract: An image forming apparatus including: an image forming unit which forms an image; a fixing unit which fixes the image transferred to a printing medium; a power supply which supplies operation power to the fixing unit; a contactless sensor sensing a temperature of the fixing unit and respectively outputting a sensor-sensing voltage and a sensor-compensating voltage; and a contactless-sensing protector which shuts off the power if the sensor-sensing voltage is higher than the sensor-compensating voltage. The fixing unit can be protected from overheating and control error through the contactless-sensing protector for sensing the fixing temperature and shutting off the power.

Abstract: Apparatuses useful for printing and methods of controlling a temperature of a surface in an apparatus useful for printing are disclosed. An exemplary embodiment of the apparatuses includes a first roll including a first outer surface and at least one first heating element for heating the first outer surface; a second roll including a second outer surface; a nip between the first outer surface and the second outer surface; a first temperature sensor for sensing a pre-nip temperature at a pre-nip location; and a first voltage modulator connected to each first heating element and the first temperature sensor. The first voltage modulator receives a temperature signal from the first temperature sensor indicative of the pre-nip temperature and modulates an AC voltage supplied to each first heating element to maintain each first heating element continuously ON at a power level ranging from partial power to full power to control the pre-nip temperature.

Abstract: An image forming apparatus that enables to continue an operation so that electric power consumption does not exceed a power supply capacity even if an electric current sensor breaks down. A temperature detection unit detects a temperature of a fixing unit that fixes a developed image transferred to sheet material. A failure detection unit detects whether an electric current detection unit that detects an electric current from a commercial power source breaks down. A control unit determines a fixing electric power supplied to the fixing unit based on the temperature detected by the temperature detection unit; and changes the determined fixing electric power so that the electric power consumption does not exceed a limit value and so as not to exceed a predetermined electric power without using an output of the electric current detection unit when the failure detection unit detects a failure of the electric current detection unit.

Abstract: An image forming apparatus includes a first fan and a second fan that are configured to generate air in a main body of the apparatus, a controller configured to control operations of the fans, and a detector configured to detect a malfunction of a first fan. When the detector detects the malfunction of the first fan, the controller increases a voltage applied to the second fan as compared with that before the malfunction is detected.

Abstract: A heating device and an image forming apparatus which make it possible to improve the degree of freedom in design to enhance the accuracy of detecting the state of a to-be-heated member, and easily reduce cost. An induction heating coil generates magnetic flux by flow of electric current therethrough. Ferrite cores formed of a magnetic material form magnetic paths. The fixing belt generates heat by the action of the magnetic flux generated by the induction heating coil 101. An antenna is disposed in an area at a location opposite to the fixing belt 120 with the ferrite cores therebetween, for detecting magnetic flux passing through the area. A control circuit determines whether or not the state of the fixing belt has changed, based on a result of detection by the antenna.

Abstract: A fixing device shifts to the anomaly detection mode in arbitrary timing except during printing. In the anomaly detection mode, a first heat generation member and a second heat generation member are off and only a third heat generation member is turned on for a predetermined time. A quantity of temperature change in a fixing member during that time is detected by a first temperature detection member or a second temperature detection member. When the quantity of temperature change is within a predetermined range, it is determined that the third heat generation member is normal. In inspecting whether the third heat generation member is normal or not, when the temperature of the fixing member is in the area exceeding T1° C. where the temperature rise gradient of the fixing member is gentler, the inspection is skipped.

Abstract: A fixing device for fixing an unfixed toner image on a recording sheet by passing the recording sheet through a fixing nip and applying heat and pressure to the recording sheet, the fixing device comprising: a heater including a resistance heater part and a supporting member, the resistance heater part having a positive resistance-temperature characteristic in a temperature range above a predetermined level, and the supporting member being insulative and supporting the resistance heater part such that the resistance heater part applies heat to the recording sheet; a current detector detecting a current supplied to the resistance heater part; and an abnormality determiner determining whether the resistance heater part has an abnormality, based on an initial current detected by the current detector at a predetermined time after a beginning of power supply to the resistance heater part and before the temperature of the resistance heater part reaches the predetermined level.

Abstract: An image forming apparatus capable of executing a mode for decelerating a rotation speed of a fixing member and a pressure member between sheets in a continuous print than that during a fixing operation.

Abstract: An image fixing apparatus has an integration circuit which is provided in a signal path from a comparison circuit to a relay drive circuit and integrates a signal input to the integration circuit, wherein an integral value of the signal input to said integration circuit reaches a reference value; and a latch circuit having an input port connected to a signal path from said integration circuit to the relay drive circuit and an output port connected to a signal path from the comparison circuit to the integration circuit. The latch circuit continuously transmits a signal from said output port to the integration circuit, upon a change in a signal level of the input port so that the relay is switched to the open position, and latches the relay in the open position.

Abstract: Provided is a fixing device including: a heater; a heating body that is heated by the heater and is caused to rotate; a pressure body that is in contact with the heating body, and is caused to rotate; a plurality of temperature sensor units each including a temperature sensing element that is covered with a protective member and is in contact with the heating body in order to sense a temperature of the heating body; and a control unit that recognizes temperatures of the heating body at respective portions thereof based on signals received from the temperature sensor units, brings the heater into an ON state if the recognized temperatures exhibit a temperature difference of a predetermined value or larger, judges that the protective member has peeled off if all the temperatures sensed by using the temperature sensor units are recognized to have risen, and corrects the temperature.

Abstract: A fixing device includes a pressing member, a belt member which rotates in contact with the pressing member and forms a nip with the pressing member, a first roller member and a second roller member to guide a rotation of the belt member, and a heating member which is mounted in one of the first roller member or the second roller member to heat the belt member, the heating member including at least two heaters to respectively heat at least two areas on the belt member corresponding to at least two width dimensions substantially parallel to a rotational axis of the one of the first roller member and the second roller member, and a sensor member to control a temperature of the belt member. The heating member includes a first heater to heat a central portion of the one of the first roller member and the second roller member, and a second heater to heat opposite ends of the one of the first roller member and the second roller member.

Abstract: A replaceable unit monitor assembly includes a substrate member, multiple thermal insulating stand-off members, and a monitor device mounted on the substrate member. The stand-off members mount the substrate member to an end hub of a fuser roll of a printing machine while limiting conductive heat transfer to the monitor device.

Abstract: A fixing device includes a fixing rotation body heating and fixing an unfixed image onto a recording medium; a pressing rotation body pressing the recording medium to the fixing rotation body; and a temperature detection unit detecting a temperature of the pressing rotation body. Further, when a predetermined time period elapses since a warm-up operation has started before a temperature detected by the temperature detection unit is equal to or greater than a predetermined temperature or when the temperature detected by the temperature detection unit is equal to or greater than the predetermined temperature before the predetermined time period elapses since a warm-up operation has started, the fixing device determines that the warm-up operation is finished.

Abstract: An image fixing device, having a belt-driving method to drive an endless belt which is entrained about at least two supporting members, including: a first supporting member on which a light transmitting area is provided; a heater which is housed within the first supporting member; a sensor which is mounted at a position to detect light rays, emitted from the heater and passed through the light transmitting area; and a control section which is configured to detect a lateral displacement of the endless belt in a width direction, based on a detected result of the light rays, detected by the sensor.

Abstract: An image forming apparatus having a heating roller and a pressing roller includes a temperature sensing unit provided to be broken when the heating roller is overheated and a pressure releasing control unit provided to release the pressing roller from the heating roller when the temperature sensing unit is broken, when a microcomputer erroneously operates due to a damage of an A/D port of the microcomputer, such that the pressing roller is forcibly released from the heating roller by the pressure releasing control unit, thereby preventing the heating roller and the pressing roller from being fused to each other.

Abstract: A fixing device includes a heating rotating body that is heated by a heater and rotates, a pressurizing rotating body that is in contact with a surface portion of the heating rotating body and rotates, and that forms a fixing portion, a pressing mechanism that presses the pressurizing rotating body against the heating rotating body and that uses a plurality of springs disposed on both end portions of the pressurizing rotating body in a direction of the second rotation shaft, and a switching mechanism that switches between a first pressing state in which first combination of springs selected from among the plurality of springs are maintained and a second pressing state in which second combination of springs selected from among the plurality of springs except the first combination of the springs are maintained.

Abstract: A fixing device includes a fixing roller that is driven to rotate, a fixing belt that is driven by rotation of the fixing roller, and a driven roller that rotates along with the fixing belt. The fixing device also includes a pressing member that is pressed against the fixing roller with the fixing belt interposed therebetween to form a nip portion, a measuring unit that measures a rotation speed of the driven roller, and a control unit that adjusts a fixing condition based on the rotation speed of the driven roller.