Abstract: An image forming apparatus according to the present invention includes a heating roller 2 fixed at a predetermined position, a pressurizing roller 3 press-fitted to the heating roller 2 by a pressurizing mechanism 4 to be movable, and a hardness change detecting mechanism 310 which becomes electrically conductive when the pressurizing roller 3 moves due to thermal expansion of the heating roller 2, and which detects a hardness change of the heating roller 2.

Abstract: A system for detecting stripper device blockage in a printing system is disclosed. The system includes a fusing member which during operation contacts a sheet of printer media to fuse a marking material to the sheet, a stripping device configured to apply pressurized air from an air supply through at least one orifice to the fuser member in order to separate the sheet from the surface and a flow measurement device in line with the air supply which measures air flow. The air flow device will assist in performing an assessment check which may include taking a baseline measurement of air flow and a diagnostic measurement of air flow. In the case where the difference between the diagnostic measurement and baseline measurement is above a different threshold, corrective action may be taken.

Abstract: A fixing device includes a first heater provided at a central part of a roller body in a longitudinal direction thereof and a second heater provided at the end of the roller body in the longitudinal direction thereof. A single thermostat is provided at a position where the difference between the first temperature when only the first heater lights and the second temperature when only the second heater lights is set within a predetermined range.

Abstract: An image forming apparatus including a thermostat arranged in a housing of a fixing device with terminals on both ends arranged slanted with respect to a longitudinal direction. A non-contact type temperature sensor is arranged adjacent to the thermostat. Discharge rollers are arranged at equidistance from a center reference line according to a smallest width of paper on a downstream side in a conveying direction of the paper of a housing. A center part of the thermostat and an opening for temperature detection of the temperature sensor are positioned between the discharge rollers.

Abstract: An image forming apparatus, including a heat roller in which a heating source is embedded, a press roller installed close to the heat roller, the press roller contacting the heat roller with a predetermined pressurizing force to form a fixing nip, and at least two overheat prevention devices installed near the heat roller to cut off a power supply to the heating source upon an overheating of the heat roller. One of the overheat prevention devices is installed at portion of the heat roller corresponding to a location within a width of a recording medium passing through the fixing nip and another is installed at a site near an end of the heat roller corresponding to a location outside the width of the recording medium.

Abstract: A fusing unit and a fusing apparatus using the fusing unit are provided. The fusing unit includes a pipe-shaped fusing roller having a heat generating unit and electrode members at both ends thereof. A power supply unit contacts the electrode members and supplies current thereto. A blocking member is disposed between the electrode members and the power supply units to block current by separating the power supply unit from the electrode members when a temperature of the heat generating unit rapidly increases.

Abstract: A method and system compare actual consumable usage (e.g., toner usage) with expected consumable usage in a xerographic machine, such as a printer or copier. Expected toner usage may be predicted from pixel count (area coverage) and actual usage is obtained from monitoring of consumable usage, such as from toner dispense data or toner bottle replacements. If the actual toner usage differs significantly from the expected toner usage (e.g., ±40%), the system may take some action, such as scheduling of a service call. Early detection of abnormal consumable usage in a xerographic machine may allow early correction before any noticeable image defects occur, such as images that are too light or too dark.

Abstract: Disclosed are a method of preventing overheating of a fuser assembly and an apparatus using the same. The method of preventing overheating of a fuser assembly includes inspecting whether a temperature of a fuser assembly is higher than a predetermined temperature. If the temperature of the fuser assembly is higher than the predetermined temperature it is determined whether there is a print command. A print sheet is passed through the fuser assembly, and conveyed to a predetermined location when there is no print command. The temperature is again inspected if there is no print command. If the temperature is lower than the predetermined temperature it is determined whether a predetermined time has lapsed. The temperature is again inspected if the predetermined time did not lapse.

Abstract: A fusing unit comprises a heating unit, a first roller and a second roller, at least one of which is heated by the heating unit, a belt which moves along the first roller and the second roller, a roller supporting unit which supports at least one of the first roller and the second roller, and a belt tension control unit which moves at least one of the first roller and the second roller so that the first roller and the second roller can move toward or apart from each other.

Abstract: A temperature detecting unit detects temperature of a fixing unit, and a control unit monitors temperatures detected by the temperature detecting unit. The control unit determines that the temperature detecting unit is abnormal when a first difference in temperatures in a first time period exceeds a first threshold.

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: A belt type fixing device includes a fix roller, a press roller rotatable in pressing contact with the fix roller, a heat roller accommodating a heat source therein and a belt passed over the fix roller and heat roller. A non-contact type temperature sensor is positioned in a sheet passing range corresponding to the width of a minimum sheet size and assigned to the heat roller while a contact type temperature sensor is positioned outside of the sheet passing range. A controller prevents the heat source from being turned on if a temperature sensed by the non-contact type temperature sensor is short of a preselected temperature B when a temperature sensed by the contact type temperature sensor reaches a preselected temperature A assigned to the non-contact type temperature sensor. A reflection type sheet sensor determines whether or not a sheet is present on the belt.

Abstract: A fuser assembly is provided with an onboard memory that may be used to store information useful in determining the conditions under which the fuser assembly has been operated. Such information can be used to better understand the root cause of fuser assembly failures, and estimate remaining fuser life, etc.

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: A fixing apparatus includes a fixing rotary body; a rotary body provided with an interval from the fixing rotary body; an endless belt rotating in a condition in which it is wound around the fixing rotary body and the rotary body; a pressure rotary body which makes a pressure contact with the fixing roller across the endless belt; a heater for heating a recording material conveyed by the endless belt; a cooling unit for cooling a recording material conveyed by the endless belt and heated by the heater; and an error detecting member for detecting an error in conveyance of the recording material. When an error is detected in the downstream of the cooling unit by the error detecting member, the recording material is stopped after the recording material on the endless belt is conveyed to a position in which the cooling unit cools the recording material.

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: 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: A sensor system for detecting gloss levels of a printed image on a substrate generated by a print engine, including: a fixing member for fixing marking particles on the substrate; an optical sensor for sensing a gloss value of the surface of the fixing member; and means for correlating the gloss value of the surface of the fixing member to a gloss value of the printed image on the substrate.

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: An image forming apparatus to prevent overheating of a fuser. In the image forming apparatus, a first overheating prevention unit compares the voltage detected by a temperature sensor, which senses temperature of the fuser, with a reference voltage and turns off the fuser when it overheats. A controller receives the detected voltage through an A/D port and performs on/off control of the fuser to keep its temperature at a predetermined level. A second overheating prevention unit compares the detected voltage with the A/D port voltage and turns off the fuser when the detected voltage is different from the A/D port voltage. When the A/D port is damaged, the A/D port voltage increased by the damage activates the second overheating prevention unit to turn off the fuser. This prevents overheating of the fuser caused by malfunction of the A/D port, thereby preventing disconnection of the thermostat or scorch of the fuser.

Abstract: An image forming apparatus includes a heat radiation unit to emit heat by an operating power supplied to the heat radiation unit, a switching unit to supply the heat radiation unit with the operating power, a relay unit to control the operating power to be supplied to the switching unit, a malfunction detector to detect whether the operating power is being supplied to the heat radiation unit and to output a malfunction signal corresponding to the switching unit or the relay unit if the power is not supplied thereby denoting a malfunction, and a controller to output an off-signal to at least one of the switching unit and the relay unit if the malfunction signal is received from the malfunction detector.

Abstract: An image heating apparatus of the present invention comprises: a heating means having heater elements, arranged along a direction intersecting in an advancing direction of a recording material, for generate heat upon energization to heat a toner image on the recording material, and a detecting means for detecting an abnormal state of the heating means. The heating means includes a plurality of heater element groups each having a plurality of the heater elements, the detecting means includes a plurality of current detecting elements for detecting the abnormal state of the heater groups respectively.

Abstract: A fixing device includes: a fixing roller; a center temperature detection unit including a protective member, the center temperature detection unit contacts the fixing roller in an axial center of the fixing roller and detects a temperature of the center section; an end temperature detection unit that contacts the fixing roller at an end portion of the fixing roller outside of a maximum print area of the recording medium and detects a temperature of the end section; and a control unit that controls heating of the fixing roller performed by the heating unit so that the heating is stopped when the value detected by the center temperature detection unit has exceeded a first upper limit value and when the value detected by the end temperature detection unit has exceeded a second upper limit value, the first upper limit value being lower than the second upper limit value.

Abstract: An image forming apparatus according to the present invention includes a heating roller 2 fixed at a predetermined position, a pressurizing roller 3 press-fitted to the heating roller 2 by a pressurizing mechanism 4 to be movable, and a hardness change detecting mechanism 310 which becomes electrically conductive when the pressurizing roller 3 moves due to thermal expansion of the heating roller 2, and which detects a hardness change of the heating roller 2.

Abstract: An image forming apparatus includes a fixing unit having a fixing roller and a heating roller to fix a toner image on a printing medium and a heater to heat the heating roller, a power supply to supply power to the heater included in the fixing unit along a power supply line, a first switch operable to selectively supply the power from the power supply to the heater, a main controller arranged to control an operation of the first switch to maintain a temperature of the fixing unit within a predetermined fixing temperature range, a second switch operable to open the power supply line between the power supply and the heater, and an auxiliary controller arranged to control an operation of the second switch to open the power supply line if the temperature of the fixing unit is outside the predetermined fixing temperature range.

Abstract: A smoke detecting device including: a light-emitting portion that emits light; a light-receiving portion that receives scattered light resulting from the light which the light-emitting portion emits being scattered by smoke generated from a recording medium on which flash-light is irradiated from a flash fusing device; and a judging section that acquires a light amount signal of the received light, from the light-receiving portion, and that judges, on the basis of the light amount signal, whether or not smoke has been generated from the recording medium on which flash-light is irradiated from the flash fusing device, the light that the light-emitting portion emits passing through a space between the flash fusing device and the recording medium, is provided.

Abstract: A thermal fixing device for fixing toner images onto recording sheets includes a heat member, a pressing member, a temperature sensor, a clock, and a control unit. The control unit performs a toner fixing control and a high-temperature heat-up control. During the toner fixing control, the control unit controls the heat member to heat up to a fixing temperature required to melt toner on a recording sheet disposed between the heat member and the pressing member. During the high-temperature heat-up control, the control unit controls the heat member to heat up to a high-temperature fixing temperature that is higher than the fixing temperature. The control unit sets length of the high-temperature heat-up control in accordance with length of the start-up time measured by the clock.

Abstract: An image forming apparatus includes: an imaging device that forms a toner image based on image data and transfers the toner image to a recording medium; a fixing device including a pair of rotatable members that defines a contact pressing portion that allows the recording medium with the toner image to pass through, and heats and presses the recording medium with the toner image; a surface potential measuring device that measures a surface potential of at least one of the pair of rotatable members; and a controller that performs control to give an alert notification that at least one of the pair of rotatable members which contacts with the toner image to be fixed should be replaced, when a result of the surface potential measured by the surface potential measuring device has exceeded a predetermined value.

Abstract: This invention can provide a fixing apparatus capable of determining its own life with high accuracy, and an image forming apparatus using this fixing apparatus. To accomplish this, a fixing apparatus includes a fixing unit whose nip portion is separable, a fixing driving motor which drives the fixing unit, a load detecting unit which detects the load acting on the fixing driving motor, and a determining unit which determines the life of the fixing unit on the basis of the difference between the load while the fixing unit is in a press-contacted state and the load while the fixing unit is in a separated state, which are detected by the load detecting unit.

Abstract: An image forming apparatus has a fixing unit for fixing a toner image formed on a recording material, and a heater, for heating the fixing unit, made of a carbon-based material. In order to detect and expect the life of the heating unit with good accuracy, the image forming apparatus further has a current measuring device for measuring a current passing through the heating unit and a notification device for providing notification of information on a life of the heating unit depending on an output of the current measuring device.

Abstract: A temperature control device includes a first heat source, a second heat source configured to heat a controlled object subjected to temperature control, a first temperature detector configured to detect a temperature of heat from the first heat source, a second temperature detector configured to detect a temperature of the controlled object, a heat transfer member configured to transfer heat produced by the first heat source to the controlled object, a heat-transfer-amount changing unit configured to change the amount of heat transferred to the controlled object by the heat transfer member, and a controller configured to control a transfer state of the heat-transfer-amount changing unit on the basis of an output from the first temperature detector and an output from the second temperature detector.

Abstract: A fixing device has a fixing belt, a trembler coil for heating the fixing belt with magnetic flux, a ferrite core around which the trembler coil is wound, and a heater for heating the ferrite core. The ferrite core has a Curie temperature which is between a fixing temperature of the fixing belt and a smoking start temperature of the fixing belt. The heating of the ferrite core with the heater allows the temperature of the ferrite core to reach the Curie temperature before the temperature of the fixing belt reaches a smoking start temperature. Thereby, an excessive rise in temperature of the fixing belt is suppressed, which prevents the fixing belt from smoking and igniting.

Abstract: An image-forming apparatus includes a movable lever which functions as a recording medium detector for detecting the passage of a recording medium and a temperature detecting portion provided on the movable lever. The temperature of the recording medium is detected without providing an additional space for a sensor for detecting the temperature of the recording medium.

Abstract: The invention prevents cracking of heater that may occur when a fixing device becomes uncontrollable and provides an image forming apparatus that is advantageous from the viewpoint of recycling of parts. A heater support member that supports a heater during abnormal temperature rise is provided at a position at which a heater holder deforms greatly when abnormal temperature rise of the heater occurs.

Abstract: A jumper cable is provided in a connector connected to an output signal of a temperature detection device and a detection signal line of fixing device specification means, and electric power supply to the temperature detection device is connected though the jumper cable. Therefore, when an electric connector connecting a main body of an image forming apparatus and a fixing device is disconnected, the overheating of the fixing device is avoided.

Abstract: The fixing device includes a pair of rotating bodies which conveys a recording medium between a nip; a heating unit which heats at least one of the rotating bodies; and a temperature detection unit which detects a temperature of at least one of the rotating bodies. The temperature detection unit detects a temperature change until an image forming apparatus is normally operated since the heating unit starts the heating, and the temperature change is stored. It is judged that the image forming apparatus is in an abnormal state when the temperature detection unit detects a temperature change different from the temperature change in the normal operation. A temperature control unit stops passage of current through the heating unit when it is judged that the image forming apparatus is in the abnormal state.

Abstract: Exemplary embodiments include systems and methods to operate an image forming apparatus including at least one or more images of an image reproduction job to be performed using the image forming apparatus and an image reproduction device having a useful life consumed by the image forming apparatus in performing the jobs. Exemplary embodiments include determining image information regarding one or more images for at least one image reproduction job; determining, for the image reproduction device, a remaining useful life of the image reproduction device; determining, for at least one job, and based on the remaining useful life of the image reproduction device, if that job can be performed based on the remaining useful life; generating, an alert notification if that job can not be completed in view of the remaining useful life; and conveying the alert notification to a user, wherein the image information includes fuser use information for reproducing the images.

Abstract: A fixing device has a heating roller with a heat source therein. A power supply operates the heat source for heating a transfer material and fixing a toner image thereon. A pressure roller is spaced from the heating roller and a facing member faces the heating roller. An endless fixing belt is mounted on the facing member and the heating roller and contacts the pressure roller to form a nip. A temperature detector faces the outer surface of the fixing belt for detecting the surface temperature thereof. An excessive temperature preventer faces part of the outer surface of the heating roller where the fixing belt is not mounted for detecting the surface temperature of the heating roller and cutting off the power supply to the heat source when the surface temperature rises above a preset temperature.

Abstract: An apparatus and a method for protecting a fixing unit from overheating and to reduce a warm-up time of a fixing unit, and an image forming apparatus using the same are disclosed. According to aspects of the present invention, a temperature of the fixing unit is detected, the detected temperature and a first reference temperature are compared, and the temperature of the fixing unit is controlled based on results of the comparison while the controller is turned on and performs initialization. Once controller initialization is completed, the detected temperature is compared to a second reference temperature and an interrupt of the fixing unit heating power occurs when the detected temperature exceeds the second reference temperature.

Abstract: A heating apparatus includes a heating roller that is heated by heating units, a main power supply that supplies power from an external power supply to the main heating unit, and an auxiliary power supply that supplies power to the auxiliary heating unit. The auxiliary power supply further includes a mass capacitor of multiple capacitor cells, which are charged by the external power supply. The connection mode of the capacitor cells is changed at least at the time of electric discharge.

Abstract: A fixing device includes a heater; a fixing rotary body having a circumferential surface which paper carrying an unfixed image makes contacts with and passes on, and heated to a predetermined temperature by a heating operation of the heater; a temperature detecting unit which detects the temperature of a portion of the circumferential surface inside a widest paper passage region in an axial direction of the fixing rotary body; a control unit which stops the heating operation of the heater when a temperature detected by the temperature detecting unit exceeds a predetermined overheat temperature; and a measuring unit which measures a continuous heating time from a point of time when the heating operation of the heater starts. The control unit stops the heating operation of the heater when the continuous heating time measured by the measuring unit exceeds a predetermined scheduled heating time.

Abstract: A fixing device includes a first heater provided at a central part of a roller body in a longitudinal direction thereof and a second heater provided at the end of the roller body in the longitudinal direction thereof. A single thermostat is provided at a position where the difference between the first temperature when only the first heater lights and the second temperature when only the second heater lights is set within a predetermined range.

Abstract: A fixing apparatus according to one aspect of the present invention comprises a first non-contact temperature detecting section which detects a surface temperature of a heat roller in the vicinity of a heating apparatus, a second non-contact temperature detecting section which is provided in non-contact with a surface of each of a heat roller and a pressure roller, and which detects a surface temperature of at least one of the heat roller and the pressure roller, and a control section which compares a difference between a first temperature detected by the first non-contact temperature detecting section and a second temperature detected by the second non-contact temperature detecting section with a predetermined specified temperature difference, and when the difference between the first temperature and the second temperature is greater than the specified temperature difference for a predetermined period or longer, stops heating of the heat roller by the heating apparatus.

Abstract: A fixing apparatus of one embodiment of the present invention has a heating member which is heated by induction heating, a pressing member which supplies a predetermined pressure to the heating member, and induction heating mechanisms which supply a predetermined magnetic field to the heating member. The induction heating mechanisms have a plurality of coils. By arranging the adjacent coils and adjacent coils to overlap, the temperature distribution in the length direction of the heating member can be made uniform.

Abstract: When a state, in which the temperature detected by a thermistor for detecting the temperature of a heating roller does not increase, is continued for 15 seconds, even though the printing operation is performed and a heater for heating the heating roller is energized, it is determined that the temperature of the heating roller does not increase normally. The same determination process is performed again while the printing operation is inhibited from being started with respect to a new sheet. In this determination process, when it is determined that the temperature of the heating roller increases normally, it is not determined as an error state. The printing operation is resumed. On the other hand, when it is determined that the temperature of the heating roller does not increase normally, the printing operation is inhibited.

Abstract: An electrophotographic image forming apparatus includes a device to set a temperature correspondence electrifying duty ratio relative to a fixing heater of a fixing device according to a detected temperature. A device is included to set a power corresponding electrifying duty ratio relative to the fixing heater, according to a detected voltage; along with a device to compare the temperature correspondence electrifying duty ratio and the power correspondence electrifying duty ratio. When the temperature correspondence electrifying duty ratio is equal to or larger than the power correspondence electrifying duty ratio, it is restricted to obtain a restricted electrifying duty ratio. Electrifying control is then performed using the restricted ratio. When electrifying the fixing heater immediately after the power has been turned on, a power correspondence electrifying duty ratio is set according to a first voltage. Electrifying control is then performed using the set power correspondence electrifying duty ratio.

Abstract: An image forming apparatus, is provided with a fixing device including a heat source to receive power supply and to generate heat, and a temperature sensor to detect a temperature of the heat source; a control section to conduct a heat source temperature control and an abnormal temperature detecting control in response to a detection result of the temperature sensor; and an electric power cutout section to cut out the power supply to the heat source on a basis of the abnormal temperature detecting control by the control section. The control section conducts the heat source temperature control for the fixing device and/or the abnormal temperature detecting control for the electric power cutout section with at least two CPUs.

Abstract: When a temperature control does not operate, and a thermal runaway state occurs, the temperatures of a heating roller and a thermostat rise rapidly. When the rise in the temperature occurs such that the temperature of the thermostat reaches or exceeds a predetermined temperature, both ends of a thermostat are brought into an open circuit state. Thus the supply of a power from a commercial power source to an exciting coil is directly cut off.

Abstract: An apparatus for fusing print sheets, such as in xerographic printing, comprises a heating element, and a temperature-sensitive mounting for the heating element. The mounting changes a position of the heating element over the course of use of the apparatus, thereby enabling a more efficient use of the heating element and emitted heat within the fusing apparatus.

Abstract: If a temperature of a heat roller 12 rises abnormally, a thermostat 54 operates. When the thermostat 54 operates, a conduction path to an excitation coil 91 of a relay 90 is cut off so that a normally open contact 92 of the relay 90 can be operated. When the normally open contact 92 operates, the supply path of a drive signal supplied from a frequency variable oscillator 81 to a transistor 63 is cut off. By the cut-off, a high-frequency current does not flow through coils 14a to 14c; therefore, induction heating with respect to the heat roller 12 is stopped.