Abstract: A voltage detection apparatus is configured to detect a voltage value applied to a first or second current path of a heater. The voltage detection apparatus detects a first period during which the voltage value of the first or second current path exceeds a threshold voltage as well as a second period during which electric power is supplied to the first current path or the second current path to control the electric power supplied to the first and second current paths. The voltage detection apparatus uses a detection result to detect a state where over-power is supplied to the heater.

Abstract: The present invention provides a fixing device that can interrupt power supply to the resistive heat layer more reliably than the conventional technology, for example, at occurrence of abnormality. Electrodes 52a and 52b are provided on a circumferential surface of a fixing roller that includes a resistive heat layer that generates heat by receiving power supply, and power is supplied to the resistive heat layer when power supplying electrodes 54a and 54b that are electrically connected to an electric power source 55 are slidingly in contact with the electrodes 52a and 52b. An insulating tape 522a is attached on the electrode 52a, and the drive controller 59 rotates a motor 58 until the electrode 52a and the insulating tape 522a are in contact with each other, so that power supply to the resistive heat layer is interrupted.

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 fixing apparatus according to one embodiment of the present invention includes a rotating hot roller, a rotating pressure roller, a heating belt that contacts the hot roller and conducts heat, a first support roller and a second support roller that are heated by a heat source, support the heating belt suspended therebetween, and conduct heat to the heating belt, a first temperature detection device that detects a first temperature of an area of the first support roller where it contacts the heating belt or an area of the heating belt where it contacts the first support roller, a second temperature detection device that detects a second temperature of an area of the second support roller where it contacts the heating belt or an area of the heating belt where it contacts the second support roller, and a device for detecting rotation stoppage of one of the support rollers.

Abstract: In an image forming apparatus including a fixing portion in which a fixing nip portion is defined between a heater and a pressure roller via an endless belt, a pressure setting portion, which sets a pressure to be exerted on the fixing nip portion, sets a first pressure during fixing, sets a second pressure lower than the first pressure when the apparatus is not used, and sets a third pressure lower than the first pressure and higher than the second pressure when a recording material is jammed.

Abstract: A fixing device according to this invention includes a heating roller, a heater driver, a thermistor, and a CPU. The heating roller has a heater and heats a recording sheet. The heater driver drives the heater. The thermistor detects a surface temperature of the heating roller. The CPU stops an operation of the heater driver when the surface temperature of the heating roller becomes higher than a predetermined temperature and, thereafter, causes the thermistor to perform detection of the surface temperature of the heating roller for a predetermined time period and issues an alarm about occurrence of a first abnormality when the surface temperature of the heating roller fails to drop in the predetermined time period.

Abstract: The heating apparatus includes a first detection part which detects whether or not the power supplied to the heat generation member is in an overpower state by detecting a positive phase of a half wave in an alternating voltage of a commercial power supply applied to the first or the second current path of the heat generation member, a second detection part which detects whether the power supplied to the heat generation member is in an overpower state or not by detecting a negative phase of a half wave in an alternating voltage the commercial power supply applied to the first current path or the second current path of the heat generation member, and a control part which controls itself to stop supplying power from the commercial power supply to the heat generation member in a case where an overpower state is detected by the first or second detection part.

Abstract: A heating control device which is capable of detecting an abnormality of an object to be heated accurately. A power-supply unit applies the electric power to the electromagnetic induction heating coil. A magnetic flux detecting unit detects a magnetic flux emitted from the electromagnetic induction heating coil across the object, and outputs a voltage corresponding to the detected magnetic flux. A changing unit changes at least one of the detected magnetic flux voltage value and an abnormality detection threshold value based on relationship between an electric power set value that defines the electric power and an input voltage inputted to the power-supply unit. A determination unit compares the detected magnetic flux voltage value changed by the changing unit to the abnormality detection threshold value, and determines an abnormality of the object when the detected magnetic flux voltage value is larger than the abnormality detection threshold value.

Abstract: An image forming apparatus includes a fixing portion for fixing an image formed on a recording material, the fixing portion including an endless belt, a heater contacted to an inner surface of the endless belt, a pressing member for forming a fixing nip with the heater with the endless belt in the nip; and a switching mechanism for switching a state of the fixing nip between a first state in which pressure at the time of a fixing operation is applied in the fixing nip and a second state in which the pressure at the time of the fixing operation is not applied in the fixing nip, wherein when electric power is supplied to the heater in the second state, the switching mechanism operates to switch the state of the fixing nip from the second state to the first state.

Abstract: An image forming apparatus and a controlling method thereof. The image forming apparatus includes a fixing member having a heating source to heat a developer of a recording medium, a power supply unit to the heating source, first and second temperature sensors for respective first and second positions on the fixing member, a width sensor for the recording medium, and a control unit, when a difference between the first temperature and the second temperature is greater than a predetermined reference value, determining whether the first temperature is abnormal based on the width of the recording medium and, when the first temperature is abnormal, interrupting the power supply to the heating source. An error in the temperature sensor is determined when a temperature difference between the first and second position of the fixing member is greater than a predetermined degree and the recording medium passes through both temperature sensors.

Abstract: A fixing unit controlling apparatus that includes a switching unit of a power supplier to supply power to a fixing unit according to a power supply controlling signal to control a temperature of the fixing unit, and a switching unit of a power shutter to shut off power supplied to the fixing unit when the fixing unit controlling apparatus operates abnormally, wherein the switching units of the power supplier and the power shutter are both connected to a snubber circuit of the power shutter.

Abstract: In one embodiment, a fixing apparatus is configured of a pressing portion for causing the pressure roller to enter a pressure applied state by applying bias, a switching portion for causing the pressing portion in the pressure applied state to enter a pressure released state by causing a cam to rotate forward, a pressure state detection portion for detecting the pressure released state, and a control portion for, when shifting from the pressure applied state to the pressure released state, turning forward the cam of the switching portion in the pressure applied state and stopping the cam after the pressure state detection portion detects the pressure released state. If the cam is turned forward with respect to the switching portion for a certain time period, but the pressure state detection portion does not detect the pressure released state, the control portion performs forward rotational direction retry control.

Abstract: An image forming apparatus which is capable of detecting occurrence of an abnormality that a fixing member which is actually in an unpressurized state is detected to be in a pressurized state, and supply of electric power to a heating member is continued. A fixing device includes a fixing belt and a pressure roller. The fixing belt and the pressure roller are pressed against each other such that a nip is formed therebetween, for nipping and conveying a transfer material through the nip while heating and pressing the same. A pressurizing unit selectively switches between a pressurizing state and an unpressurizing state. When the pressurizing unit is in the pressurized state, a heater heats the fixing belt. The heating of the fixing belt is stopped based on a temperature detected by a thermistor after a lapse of a predetermined time period from start of the heating.

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 includes an overheat prevention device to control a heater based on a fusing temperature detected by a temperature sensor within a predetermined range when a controller generates an abnormal heater control signal.

Abstract: An apparatus for image formation comprises a fixing member, a pressing member, a heating member, a sensor, and a controller. The heating member heats at least one of the fixing and pressing members during a heating operation. The sensor senses the surface temperature of at least one of the fixing and pressing members. If the surface temperature sensed by the sensor exceeds a threshold temperature, the controller stops the heating operation of the heating member. If the sensed temperature drops below the threshold temperature, the controller starts the heating operation of the heating member. The controller includes a period measuring unit for measuring the switching period at which the controller switches the starting and stopping of the heating operation of the heating member. The controller restrains the heating of the fixing and pressing members if the switching period exceeds a reference time.

Abstract: An image forming apparatus, including: a fixing device having: a first heat generator for generating heat for a fixing processing, the first heat generator using electric power supplied by a commercial power source; and a second heat generator for generating heat for the fixing processing, the second heat generator using electric power supplied by the auxiliary power source device; a heat generation controller for allowing the first heat generator and the second heat generator to generate heat; a sheet jam detector for detecting a sheet jam of a recording sheet which occurs in the image forming section having the fixing device and a conveyance path of a recording sheet; and a charge controller for allowing charging of the auxiliary power source device to start when the sheet jam detector detects a sheet jam, and the charged capacity detector detects no full charge of the auxiliary power source device.

Abstract: A fixing device includes a fixing member, an induction heating unit, a pressing member, and a damage detection unit. The fixing member heats a toner image on a recording medium to fix the toner image onto the recording medium. The induction heating unit heats the fixing member by electromagnetic induction. The pressing member presses the fixing member to form a fixing nip portion. The fixing member includes a heat insulating elastic layer and a sleeve layer. The sleeve layer is located outside the heat insulating elastic layer and is provided with an outer conductive layer that generates heat from a magnetic flux generated by the induction heating unit. The damage detection unit is connected to the outer, conductive layer.

Abstract: A thermal fixing device includes a fixing member, a flexible endless belt, a flexible endless belt, a rotary pressure member, a heating unit, and a rotation detector. The flexible endless belt is disposed on an outer circumferential surface of the fixing member. The rotary pressure member is disposed parallel to and pressing against the fixing member via the endless belt. The heating unit heats the endless belt. The rotation detector detects a rotation speed of the endless belt. The heating unit is powered off when the rotation speed of the endless belt detected by the rotation detector is at or below a predetermined threshold value.

Abstract: A fixing controller capable of rapidly detecting an excessive temperature rise, even if an abnormal temperature rise takes place in a state that a rotor of a fixing unit, such as a thin-walled roller or belt, stops rotating. A rotating belt is heated by a coil, a belt temperature is detected by a thermistor, and a drive frequency of a driving circuit for driving the coil is controlled by a control circuit. When the temperature detected by the thermistor becomes equal to or higher than a predetermined temperature, the drive circuit is stopped by an excessive temperature rise detecting circuit. The thermistor is heated such that a difference between the temperatures detected by the thermistor when the belt is rotating and when the belt stops rotating becomes equal to or larger than a predetermined temperature difference.

Abstract: An image forming apparatus includes a main power unit that outputs a first DC power and an auxiliary power unit that outputs a second DC power to the components of the image forming apparatus. The auxiliary power unit includes a rechargeable capacitor. A measuring unit measures performance of the capacitor and a determining unit determines performance insufficiency of the capacitor based on the measured performance and the system configuration of the image forming apparatus. The performance is, for example, changes in a capacitance of the capacitor with time. When the determining unit determines performance insufficiency of the capacitor, a control unit adjusts, for example, a use range of the capacitor.

Abstract: A fixing unit removably installable in an image forming apparatus includes an endless fixing member; a metal member disposed in proximity to an inner surface of the fixing member; a nip formation member supported by the metal member to slidably contact the fixing member or oppose the fixing member via a slide sheet; a heater to heat the metal member to heat the fixing member; a rotary pressing member to rotate the fixing member, disposed opposite the nip formation member via the fixing member to form a nip between the rotary pressing member and the fixing member; a rotation detector to detect a rotational state of the fixing member. Heating rotation of the fixing member is continuously performed until a predetermined rotational state of the fixing member is obtained, to spread lubricant substantially uniformly at least between the fixing member and the metal member.

Abstract: A fixing device includes a fixing member, a pressure member, and a damage detecting unit. The fixing member includes a heat-insulating elastic layer, to which a conductive thin-film layer is provided. The pressure member presses against the fixing member to form a fixing nip. The damage detecting unit detects the electric resistance of the thin-film layer. The damage detecting unit detects a change in the electric resistance of the thin-film layer, thereby detecting damage to the fixing member. Depending on the extent of the damage, the condition of conveyance of a recording medium to the fixing nip is changed.

Abstract: An image forming apparatus including a fixing device using an induction heating method determines a driving frequency for a switching element configured to drive an induction coil, according to a difference between a detected temperature of an electrically conductive heating element provided in the fixing device and a target temperature. When the determined frequency is a predetermined minimum frequency and a current flowing through the induction coil is at a predetermined value or less, the image forming apparatus generates a signal indicating the abnormality of electric power supplied to the induction coil.

Abstract: A fixing device for fixing a toner image on a recording medium includes a fixing roller, a pressing roller, and at least one of a sheet guide, a sheet separation plate, and an electric component module. The fixing roller rotates in a predetermined direction of rotation. The pressing roller rotates and contacts an outer circumferential surface of the fixing roller to form a nip between the pressing roller and the fixing roller through which the recording medium bearing the toner image passes to fix the toner image by heat and pressure. The position of the pressing roller is changeable relative to the fixing roller. At least one of the sheet guide, the separation plate, and the electric component module moves in conjunction with movement of the pressing roller as a single integrated unit without changing relative positions with respect to the pressing roller.

Abstract: A fixing device includes a heat conductive member; a flexible fixing belt looped around the heat conductive member, an inner circumference of the flexible fixing belt slidably contacting a portion of an outer circumferential surface of the heat conductive member; a rotary pressing member disposed opposing the heat conductive member; heat sources disposed in a circumferential direction of the fixing belt at a predetermined interval to heat the heat conductive member; and temperature detectors provided to detect a surface temperature of the fixing belt at a detection position at which heating intensity of a corresponding one of the heat sources is not affected by any other one. In operation, the inner circumferential surface of the fixing belt contacts the heat conductive member at a position at which each temperature detector contacts the fixing belt as the detection position or a position proximal to the detection position of each temperature detector.

Abstract: A fixing device includes a substantially cylindrical metal member, a heater, an endless, flexible fixing member, a rotary pressing member, a stationary member, a first temperature detector, and a second temperature detector. The first temperature detector is disposed upstream from a nip in a rotation direction of the fixing member to detect a surface temperature of the fixing member. The second temperature detector is disposed downstream from the nip in a rotation direction of the pressing member to detect a surface temperature of the pressing member. When a difference between a surface temperature of the fixing member detected by the first temperature detector and a surface temperature of the pressing member detected by the second temperature detector after a predetermined time has elapsed since the first temperature detector detects the surface temperature of the fixing member is greater than a predetermined threshold, the heater stops heating the metal member.

Abstract: A fixing device for fixing a toner image onto a recording paper includes a heating member for heating the recording paper, a pressing member for pressing the heating member by pressure-applying contact, a casing accommodating the heating member and the pressing member, and being provided with an exit port for discharging the recording paper, and a closing unit added to the exit port for keeping a temperature of the casing. The closing unit has a rotation member, and an opposed member forming a nip region together with the rotation member.

Abstract: An image forming apparatus for forming an image on a sheet, includes: an image forming section which forms the image on the sheet; a fixing device which fixes the image onto the sheet; a first duct which covers the fixing device and ventilates air heated by the fixing device; a second duct, which covers the first duct and ventilates cool air introduced from outside; and an exhaust fan which exhausts the air that has passed through each of the first duct and the second duct.

Abstract: A fixing device including a heating element and a pressure element, for fixing a developer image transferred onto a recording sheet is provided. The pressure element is configured to be positioned selectively in two or more pressing positions defined relative to the heating element. The pressure element in any one of the pressing positions is configured to be pressed against the heating element. A plurality of interrupter elements are provided opposite to the heating element. Each of the interrupter elements is configured to sense a temperature of the heating element and to interrupt a flow of electrical current to a heat source for heating the heating element when the temperature is not lower than a predetermined threshold value. The interrupter elements are arranged in positions corresponding to the pressing positions.

Abstract: When the temperature of a fixing section has not reached a fixable temperature and the condition of an image forming apparatus is an abnormal temperature rising condition, a print controller causes a toner image conveying section to move a toner image on an intermediate transfer member to a predetermined toner image standby position upstream of a secondary transfer section and to put the toner image on standby at the toner image standby position, and causes a recording medium conveying section to put a recording medium on standby at a predetermined sheet standby position upstream of the secondary transfer section. Thereafter, when the temperature of the fixing section reaches the fixable temperature, the print controller causes the secondary transfer section to transfer the toner image on the intermediate transfer member onto the recording medium.

Abstract: An image formation device, which can properly execute an image formation process even if at least any one of plural fixing units included in the image formation device cannot be used due to a breakdown or the like, is provided. In the image formation device, if a first fixing unit cannot be used, a CPU controls not to execute a first transportation process of using the first fixing unit and a second fixing unit and a second transportation process of using the first fixing unit. Further, if the second fixing unit cannot be used, the CPU controls not to execute the first transportation process but to execute the second transportation process.

Abstract: A fixing device usable with an image forming apparatus having a fixing roller to fix a toner on a recording medium, a heater to heat the fixing roller, and an alternating current (AC) power source to supply an AC electric power to the heater may include a power converting part to convert the AC electric power of the AC power source and to supply the converted power to the heater; a relay including a first relay contact point disposed on a first AC power supply line between the AC power source and the power converting part and a relay coil to open and close the first relay contact point, the relay selectively supplying the AC electric power from the AC power source to the heater and the power converting part; a direct current (DC) power supplier to supply a DC power to the relay coil; and a thermoswitch interposed between the relay coil and the DC power supplier and mounted adjacent to the fixing roller so as to interrupt the DC power from the DC power supplier to the relay coil, when a temperature of the fixi

Abstract: Optical measurement system and method for determining a wear level of printer components such as fuser rolls. Papers can be treated with optical brighteners, which act as distinct tag/trace molecules with fluorescent properties. A fluorescence pattern on the fuser roll can be changed in accordance with the edge density distribution in the print engine, when paper edges are accumulated on the fuser roll surface. A photo detector can capture a two-dimensional, digital image of the fluorescence pattern on the fuser roll surface to be measured, after illuminating the fuser roll, with intensity near ultraviolet range, by a light source. An image processor with a parameterized model can measure changes in the fluorescence pattern by analyzing the digital image of the fuser roll surface in order to determine the level of edge wear on the fuser rolls.

Abstract: Disclosed are an electrophotographic apparatus for forming images on sheets, and corresponding methods. The electrophotographic apparatus includes an endless fuser belt for fusing toner particles to the sheets to form the images, a sensor for detecting a defect position of at least one defect in the endless fuser belt, and a controller that receives the defect position of the at least one defect on the endless fuser belt from the sensor, wherein the controller positions the endless fuser belt relative to the sheets to avoid the at least one defect from coming into contact with the toner on the sheets during fusing of the toner particles to the sheets.

Abstract: Disclosed are a heating unit and its malfunction determining method, an image fixing device including the heating unit, and an image forming apparatus including the image fixing device. The method comprises a temperature detection step of detecting temperature of a heating body in the heating unit; a first malfunction determination step of obtaining a temperature rise time of the heating body, and then determining whether there is malfunction in the heating unit; and a second malfunction determination step of calculating a temperature increase rate of the heating body, and then determining whether there is malfunction in the heating unit.

Abstract: An image fixing assembly includes a heating unit having a heating element and a fusing member enclosing the heating element; a backup member; and a heat conducting member. The fusing member is configured to rotate around the heating element. Further, the fusing member is capable of being heated by the heating element. The backup member is abuttingly coupled to the fusing member for configuring a nip portion therebetween, and is capable of pressing media sheets against the fusing member, when the media sheets pass through the nip portion. The heat conducting member is capable of retractably coupling to one of the fusing member and the backup member for enabling flow of heat between the one of the fusing member and the backup member, and the heat conducting member, for reducing a thermal gradient. Further disclosed is a method for fixing images on the media sheets using the image fixing assembly.

Abstract: An image heating apparatus includes a heating rotary member, which heats an image on a recording material at a nip portion, an air blowing device for blowing air toward an air blowing port to cool a predetermined area of the heating rotary member, a shutter, which opens and closes the air blowing port, and a determination device. The determination device determines an execution of an operation of the air blowing device with the shutter opened after a first job is completed, in accordance with a size of a recording material in a width direction perpendicular to a recording material transport direction in a second job for supplying a recording material, between an execution termination of the first job for continuously supplying recording materials having a size smaller than a predetermined size in the width direction, while operating the air blowing device, and a start of a recording material supply of the second job, in a case that the second job is executed subsequent to the termination of the first job.

Abstract: A failure predictor for predicting failure of a fixing device including a first characteristics value extractor to extract a first characteristics value representing a time interval between each implementation of repair of a surface of one of a pair of rotary bodies, a second characteristics value extractor to extract a second characteristics value representing a change in a degree of glossiness on the surface of one of the pair of rotary bodies during a period of time between before and after repair of the surface of one of the pair of rotary bodies, a third characteristics value extractor to extract a third characteristics value representing a change in a current value of a drive motor, and a determination device to predict failure of the fixing device caused by the condition of the surface of one of the pair of rotary bodies using the extracted first, second, and third characteristics values.

Abstract: An image heating apparatus includes a coil; a rotatable image heating member for generating heat by a magnetic flux generated by the coil to heat an image on a recording material; a voltage source for applying a high frequency current to the coil; a temperature detecting member for detecting a temperature of the image heating member; control device for controlling electric power supply to the coil from the voltage source on the basis of an output of the temperature detecting member such that the temperature of the image heating member is maintained at a set temperature T; and protecting device for stopping the electric power supply to the coil when the output of the temperature detecting member indicates a predetermined abnormal temperature Te, wherein at least a part of the image heating member is made of a magnetism-adjusted alloy having a predetermined magnetic permeability decrease start temperature Tc? and a predetermined Curie temperature, and wherein T?Tc?<Te<Tc.

Abstract: A fixing apparatus which heat-fixes a toner image transferred onto a sheet, including: a heating device configured to generate eddy currents in a conductive heating element using a magnetic core and an exciting coil to produce heat; a core moving unit configured to move the core; a current detecting unit configured to detect a current flowing through the exciting coil; and an abnormal signal output unit configured to output a signal indicating an abnormality when a difference between a first current value and a second current value is smaller than a predetermined threshold value, the first current value being detected by the current detecting unit before the core is moved by the core moving unit, the second current value being detected by the current detecting unit after the core is moved by the core moving unit.

Abstract: A method and apparatus for automatically adjusting nip width based on a scanned nip print image on ultraviolet (UV)-sensitive media in an image production device is disclosed. The method may include receiving a signal to generate a nip print, automatically inserting a sheet of UV-sensitive media into a fuser nip in the image production device, pausing the sheet of UV-sensitive media in the fuser nip for a predetermined time period, illuminating the UV-sensitive media with ultraviolet light to generate a nip print, scanning the generated nip print, determining if a nip width adjustment is required based on the scanned nip print, and if it is determined that a nip width adjustment is required based on the scanned nip print, adjusting the nip width using a nip width adjustment device.

Abstract: An apparatus to protect a half or full bridge circuit including a first switching unit and a second switching unit in an image forming apparatus performing induction heating, the apparatus including a switching control unit to control operations of the first switching unit and the second switching unit by generating and outputting a first driving signal to turn on or off the first switching unit and a second driving signal to turn on or off the second switching unit; and an arm-short detecting unit to output a disable signal to stop operation of the switching control unit in response to the first driving signal and the second driving signal simultaneously being signals to turn on the first switching unit and the second switching unit.

Abstract: A first feature quantity computing unit that computes a first feature quantity representing an average of a plurality of driving loads recorded by a driving load of a fixing section recording unit of an image forming device that records the driving load acquired by a driving load acquiring unit that acquires the driving load, a second feature quantity computing unit that computes a second feature quantity representing a deviation of the plurality of the driving loads, and a diagnosis unit that performs failure diagnosis including estimation of a cause of a failure of the fixing section using the first feature quantity and the second feature quantity are used.

Abstract: A fixing device including a fixing member; a heat source to heat the fixing member; a power supply to supply power to the heat source; a thermostat provided in the middle of a circuit connecting the heat source and the power supply to block power supply from the power supply to the heat source upon detection of a temperature of the fixing member equal to or greater than a predetermined temperature; a support member to contact terminals fixed to the thermostat to support the thermostat; and electrode plates provided opposite the support member with a gap therebetween to form a part of the circuit by connecting to surfaces of the terminals of the thermostat opposite surfaces thereof contacting the support member while the terminals are positioned within the gap. The electrode plates include a first guide part to guide the terminals into the gap.

Abstract: An electrically isolated temperature sensor for use with a printer, copier, or all-in-one fuser. The fuser includes an AC driven heater to which a thermistor is mounted for sensing the temperature of the fuser heater. A resistance of the thermistor controls the period of a periodic signal generated by an astable multivibrator. An optical isolator isolates the printer fuser from down line processing circuits, and transfers the periodic signal to such processing circuits. The printer fuser employs a separate floating ground that is not connected to other DC circuits of the printer. With this arrangement, any AC power that is inadvertently coupled from the heater to the DC circuits of the fuser is isolated thereto. The AC power is isolated to the fuser and cannot be propagated through the fuser to other down line circuits of the printer.

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 of the invention detects a temperature of plural positions of a heat roller by a multiple non-contact temperature sensor at the same time and controls the temperature of plural heat source members. The non-contact temperature sensor and a contact temperature sensor detect the temperature of the same position. According to the detection result, maintenance is performed or a temperature conversion table is corrected, the non-contact temperature sensor is maintained with high precision, and the heat roller is controlled the temperature with high precision.

Abstract: A fixing device includes a fixing member including a recording medium passing area inside thereof through which the recording medium passes, a first heater disposed in the fixing member to heat the fixing member, a first pressing member disposed opposite the fixing member to press against and rotate the fixing member to fix the unfixed toner image on the recording medium, a second heater disposed outside the recording medium passing area and inside the fixing member to heat the fixing member cyclically in a given cycle of heating, a temperature detector to detect a change in the temperature of the fixing member when the fixing member is cyclically heated by the second heater, and a determination unit to evaluate a condition of rotation of the fixing member based on the cycle of heating by the second heater and the cycle of change in the temperature detected by the temperature detector.

Abstract: In a fixer unit system and method to detect a fire in a fixer unit of an electrographic image generation device, at least one portion of a fixer region of the fixing unit is monitored with a photoelectric sensor arranged adjacent to a substrate material having a toner image to be fixed, at least one portion of radiation generated by at least one heat radiator of the fixer unit is not detected by the photoelectric sensor by not passing said at least one portion of the radiation generated by the at least one heat radiator through to the photoelectric sensor by use of an optical filter associated with the photoelectric sensor. An error signal is output when a fire in the fixer region is detected with the photoelectric sensor.