Abstract: In a fixing device for electrophotography, a fixing sheet carrying thereon a toner image is passed under application of heat and pressure between a toner heating member and a press roller to fix the toner image onto the a fixing sheet. The fixing device is so controlled that a temperature of the toner heating member is set higher and a temperature of the press roller is set lower in a ready-display state during warm-up for starting the fixing device or returning from a power save mode, respectively compared with corresponding set temperatures of the toner heating member and the press roller in a normal ready state. As a result, consumption of fixing energy is suppressed and the time until the ready state is reduced by a relatively simple control.

Abstract: A fixing device includes a fixing belt including a metal layer, a pressing member to form a nip between the pressing member and the fixing belt, an induction current generating coil that faces an outer periphery of the fixing belt, and heats the fixing belt located at a nip position through a hollow inside of the fixing belt, and a coil controller supplies a high frequency to the induction current generating coil.

Abstract: The image forming apparatus includes an image forming unit, a fixing part and a controller controlling power to be supplied to the heating unit so as to keep the temperature of the heating unit at a control target temperature. When the fixing process is ended, in a standby-mode, the supply of power to the heating unit is started to keep the temperature of the heating unit at the control target temperature, and the start time of the supply of power to the heating unit is set to a time when the temperature of the heating unit is lowered to a predetermined temperature lower than the control target temperature, thereby reducing the power consumption of the image forming apparatus in the standby-mode.

Abstract: A aspect of the invention is an image scanning apparatus including: a document feeder configured to sequentially feed document sheets stacked in the document feeder; an image scanning unit configured to scan the document sheets fed by the document feeder and to output image data thereof; a memory configured to store therein the image data; a detector configured to detect a failure of feeding the document sheets by the document feeder; a notifier configured to report the feeding failure when the detector detects the feeding failure; and a display unit configured to display the image data stored in the memory, upon detection of the feeding failure.

Abstract: A fixing device is provided with a fixing unit for fixing a toner image; a magnetic flux generator including a switching element for generating a magnetic flux; and a control unit for performing a start-up mode for raising the temperature of the fixing unit to a fixing temperature by the magnetic flux and a steady mode for maintaining the temperature of the fixing unit at the fixing temperature. The control unit turns off the switching element when the temperature of the switching element is equal to or higher than a first reference temperature lower than a destruction temperature during a period of the start-up mode, and turns off the switching element when the temperature of the switching element is equal to or higher than a second reference temperature lower than the destruction temperature and higher than the first reference temperature during a period of the steady mode.

Abstract: An image heating apparatus includes a control unit that executes a long grain feed mode of conveying a long grain recording sheet whose grain direction is in parallel with a conveying direction of the recording sheet and a short grain feed mode of conveying a short grain recording sheet whose grain direction is orthogonal to the conveying direction of the recording sheet, the control unit changing, in accordance to the long grain feed mode and the short grain feed mode, temperature of a first rotating body set by the heating unit and setting of at least either one changeable setting among settings of a pressure-contact mechanism and a driving mechanism configured such that the setting of at least one of them is changeable.

Abstract: The fixing apparatus includes a first rotary member that comes into contact with the unfixed toner image, a second rotary member that is heated by the first rotary member and forms the nip portion together with the first rotary member, and a air supply unit that supplies air to the second rotary member. The fixing apparatus is configured to execute a first mode of warming the first rotary member and the second rotary member as a warm-up while rotating the first rotary member and the second rotary member before the fixing process and performing supplying air by the air supply unit in the fixing process, and a second mode of performing the warm-up for a longer period than in the first mode and performing the supplying air by the air supply unit in the fixing process.

Abstract: An image forming apparatus includes: an image forming part which picks up a recording medium at a predetermined pickup timing and forms an image at a predetermined printing speed; and a controller which accelerates the timing for picking up the recording medium in advance of the predetermined pickup timing, and which lowers the printing speed so as to allow the printing operation to take place at a lower fusing temperature during warming up from a cold start in order to shorten the first print output time (FPOT).

Abstract: An image forming apparatus includes: an image forming unit configured to form a toner image on an image bearing member according to printing information; a transfer unit configured to transfer an unfixed toner image formed by the image forming unit onto a printing sheet; a fixing unit configured to heat the unfixed toner image carried on the printing sheet and fix the unfixed toner image on the printing sheet; a temperature measuring unit configured to measure the temperature of the fixing unit; and a quick-print processing unit configured to cause, when printing is started, even if the temperature of the fixing unit measured by the temperature measuring unit does not reach a ready temperature, the image forming unit to perform an image forming operation on the basis of a low process speed for enabling the fixing in the fixing unit, which is lower than a normal process speed corresponding to the ready temperature.

Abstract: An apparatus and method for controlling power of a fixing unit is provided. The apparatus includes a power supply unit supplying DC power to the fixing unit, and a power controller controlling the power supply unit to gradually increase a DC power supply time until a pre-set time is reached. Accordingly, a flicker characteristic can be reduced by gradually increasing a supply time of DC power to the fixing unit.

Abstract: An image forming device fusing a developer transferred to a recording medium surface based on inputted print data includes a heat source, a fusion member supported in a freely rotatable manner and heated by the heat source, a pressure application member positioned to face the fusion member and pressing against the fusion member, a temperature detection device positioned to face the pressure application member and detecting a surface temperature of the pressure application member, and a temperature control part controlling a heating temperature by the heat source based on a detection result by the temperature detection device. The temperature control part selects a second set temperature that is lower than a preset first set temperature when the surface temperature of the pressure application member detected by the temperature detection device is less than a predetermined temperature, to control a temperature of the fusion member.

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: An image processing apparatus includes: an image processing unit that executes an image process in accordance with an instruction by a user; an accumulating unit that accumulates electric energy consumed in a preparation process of the image processing unit for each user; and a control unit which, if the image processing unit is made usable by the preparation process and executes image processes in accordance with a plurality of instructions by a plurality of users, controls the accumulating unit to allot and accumulate the electric energy for each of the plurality of users.

Abstract: A power control method and apparatus to heat a heating roller includes heating a heating roller provided to fix a toner image of print data in an image forming apparatus, the heating roller having a heating resistor to receive roller power. The power control method includes gradually increasing a maximum level of a source power supplied from an external source up to a specific maximum supply level, and supplying the maximum source power to the heating resistor as the roller power while gradually increasing the maximum level of the source power up to a specific maximum supply level, measuring a surface temperature of the heating roller, and supplying the source power of which maximum level is equal to the maximum supply level to the heating resistor as the roller power until the measured surface temperature reaches a specific fixing target temperature, and fixing the toner image onto a printing medium.

Abstract: A fixing device includes a fixing belt including a metal layer, a pressing member to form a nip between the pressing member and the fixing belt, an induction current generating coil that faces an outer periphery of the fixing belt, and heats the fixing belt located at a nip position through a hollow inside of the fixing belt, and a coil controller supplies a high frequency to the induction current generating coil.

Abstract: An image forming apparatus includes a fixing device; a mode selecting unit for selecting one of a normal mode and a power save mode; and a fixing control unit. The fixing device includes a rotational member, a pressing member disposed to press against the rotational member for sandwiching and pressing a print medium with the rotational member after a developer image is developed on the print medium, and a heating portion for heating the rotational member. In the normal mode, a normal printing operation is enabled. In the power save mode, the printing operation is partially terminated to conserve power consumption. The fixing control unit controls the rotational member to rotate for a specific amount when the mode selecting unit selects the power save mode.

Abstract: A fixing device is disclosed, including: a fixing rotative body, a heat source, and a control part. The control part conducts a printing temperature control which varies an ON ratio per unit time of the heat source based on a detection result of the temperature detecting part to maintain a printing target temperature in a printing state, conducts a waiting temperature control which performs an ON/OFF control based on the detection result of the temperature detecting part to maintain a waiting target temperature in a waiting state after a printing operation ends, and conducts a forcible ON control which forcibly turns on the heat source for a predetermined time before starting the ON/OFF control when the detection result of the temperature detecting part after the printing operation ends is lower than the waiting target temperature.

Abstract: An image forming apparatus includes a plurality of heaters 56 for heating the fixing roller 52, a plurality of temperature sensors 57 for detecting the temperatures of the areas to be heated by the plurality of heaters 56 respectively, and a control unit 11 for turning on and off the plurality of heaters 56 on the basis of the temperatures detected by the plurality of temperature sensors 57. If one of the heaters 56 is on when the area to be heated by the other heater cools down to the ON temperature, the control unit 11 turns on the other heater with the same timing as the one heater is turned off.

Abstract: An image forming apparatus includes a reading unit, a receiving unit, an image forming unit, a fixing unit, and a control unit. The reading unit generates generated image data indicating the image. The receiving unit receives external image data. The image forming unit forms, by using a recording agent, an image on a sheet based on the generated or external image data. The fixing unit fixes the recording agent on the sheet. The control unit controls to start raising a temperature of the fixing unit at a first timing, where a copy process is executed. The control unit controls to start raising the temperature of the fixing unit at a second timing, which is later than the first timing, where a printing process is executed.

Abstract: An image forming apparatus includes a non-contact temperature sensor that commences measuring temperature of a heating member in a fixing device once a waiting period of a certain length has passed after power supply commences to the fixing device, and acquires information indicating a heating condition of the heating member when the fixing device transitions to a non-power supplied state. Once the waiting period has passed, the apparatus controls to increase the heating member temperature to a target temperature, while monitoring the heating member temperature using the non-contact temperature sensor. During the waiting period, the apparatus estimates the heating member temperature at a present time using the information, and controls to increase the heating member temperature when the estimated temperature does not exceed a threshold temperature, and prevent increase of the heating member temperature when the estimated temperature exceeds the threshold temperature.

Abstract: An image forming apparatus is provided that includes: a heating member that heats a recording sheet; a pressure member that presses the recording sheet between the heating member and the pressure member; an adjustment mechanism that causes the heating member and the pressure member to contact or to separate; and a control section that, at a time of a warm-up operation or an idling operation, based on a predetermined condition, controls the adjustment mechanism so as to cause the heating member and the pressure member to contact at a contact pressure that is lower than a contact pressure between the heating member and the pressure member at a time of image formation or is approximately identical to the contact pressure at a time of image formation.

Abstract: A fixing device includes a heating member, a pressurizing member, a coil wound in a loop shape in the width direction of the heating member to generate a magnetic flux that inductively heats the heating member, and a magnetic core adjacent to the coil. The magnetic core is configured to apply the magnetic flux to an inductive heat-generating layer of the heating member. The magnetic core includes first core parts and second core parts. The first core parts are positioned to enclose the coil in a direction orthogonal to a direction in which paper is conveyed. The second core parts are placed in hollow areas formed by the loops of the coil at both ends in the direction orthogonal to the paper conveyance direction. The second core parts have a higher Curie temperature and a lower thermal capacity than the first core parts.

Abstract: An image processing apparatus includes an image forming unit, power supplier, power controller, memory, signal transmission unit and transmission timer. The image forming unit forms an image based on image data from a plurality of host devices. The power supplier supplies power to a power system including the image forming unit. The power controller controls the power from the power supplier to the power system. The memory stores a usage amount of each host device. The signal transmission unit transmits a response request to a host device having at least a predetermined usage amount. The transmission timer counts a first time period from a transmission of the response request. The power controller halts the power from the power supplier to the power system when determining, based on the first time period, that a reply to the response request is not transmitted from the specific host device for a predetermined period.

Abstract: A fixing device for fixing a toner image on a recording medium includes a hollow, fixing rotary body rotatable in a given direction of rotation and a first heater disposed opposite an inner circumferential surface of the fixing rotary body to heat the fixing rotary body. A pressing rotary body is pressed against the fixing rotary body to form a fixing nip therebetween through which the recording medium bearing the toner image is conveyed. A heat conductor, disposed opposite the first heater and the inner circumferential surface of the fixing rotary body, is disconnectably connected to a guide disposed downstream from the fixing device in a recording medium conveyance direction to guide the recording medium discharged from the fixing nip. The heat conductor conducts heat received from the first heater to the guide.

Abstract: A heating unit is heated by supply of an alternate-current power. A heating control unit executes a phase control to supply the alternate-current power to the heating unit for an ON-width in at least a half-wave period of the alternate-current power. A storing unit stores therein parameters for calculating the ON width. The heating control unit calculates the ON width based on the parameters stored in the storing unit and executes the phase control using a calculated ON width.

Abstract: A power control apparatus and an image forming apparatus include a non-heating control unit to control non-heating control components according to a power-on signal, and a heating control unit to increase a level of a source power supplied as roller power and to supply the increased level of the roller power to a heating roller according to phases of current of the source power such that heating the roller reaches a temperature before a power-on process of the non-heating control unit is completed.

Abstract: An image forming apparatus having a first mode for operation with predetermined power consumption and a second mode for operation with less power consumption than the power consumption in the first mode includes: a paper cassette capable of being attached to a predetermined section of the image forming apparatus, the paper cassette storing paper therein; a detection part detecting the attachment and detachment of the paper cassette to and from the predetermined section; and a shift part, upon the detection by the detection part that the paper cassette has been attached to the predetermined section during the operation in the second mode, shifting the image forming apparatus from the second mode to the first mode.

Abstract: A method and an apparatus to control power supplied to a heating roller and a phase control circuit corresponding to the method or the apparatus. The phase control circuit may include an examination unit to compare levels of a sine wave having a predetermined first period and a switching signal to increase and decrease repeatedly according to a predetermined second period, and a phase control signal generation unit to generate a phase control signal having a non-zero in intervals of time sections including a time when levels of the switching signal and the sine wave which is in a decreasing section are equal to each other during a time period when the level of the sine wave is zero, and a time when levels of the switching signal and the sine wave which is in an increasing section are equal to each other during a time period when the level of the sine wave is zero.

Abstract: The image forming apparatus includes a fixing portion, a temperature detection element, and a power control portion. The power control portion is capable of setting a first power supply control mode for supplying power according to the detected temperature for each one control cycle, a second power supply control mode for supplying power according to the detected temperature for each one control cycle and a third power supply control mode for supplying predetermined power, and switches, immediately before a leading edge of the recording material enters the fixing portion, a state of supplying the power in the first power supply control mode to a state of supplying the power in the second power supply control mode, and then switches the state of supplying the power in the second power supply control mode to a state of supplying the power in the third power supply control mode.

Abstract: A fixing device capable of shifting to a sleep state includes a heat source; a rotatable fixing member that is partly heated by the heat source to heat an unfixed image carrying surface of a recording medium; a rotatable pressing member that is in pressure contact with the fixing member to form a nip portion between the pressing member and the fixing member; a rotation drive unit that directly or indirectly rotates the fixing member; a temperature detecting unit that detects a temperature of the fixing member; and a controller configured to prohibit the fixing device from shifting to the sleep state when the temperature of the fixing member in a region facing the heat source is equal to or more than a predetermined temperature T1 at a point when a predetermined time period t1 has elapsed from the stop of rotation drive of the rotation drive unit.

Abstract: A fixing device includes a temperature controller that controls a temperature of a fixing rotary body based on the temperature of the fixing rotary body detected by a temperature detector so as to heat the fixing rotary body to a plurality of preset target temperatures that includes a first target standby temperature, a target fixing temperature, a target idle temperature, and a second target standby temperature. When the target fixing temperature is lower than the first target standby temperature, the temperature controller separates a pressing rotary body from the fixing rotary body to idle the fixing rotary body for a predetermined idle time period before a fixing operation starts. After the fixing operation, the temperature controller controls a heater to change the temperature of the fixing rotary body to the second target standby temperature.

Abstract: An image forming apparatus includes a fixing member; a pressing member abutting against the fixing member; a first temperature detection unit for detecting a temperature of the fixing member; a heating member for heating the fixing member; a power control unit for controlling power supplied to the heating member; a drive unit for rotating the fixing member; and a control unit for controlling the power control unit and the drive unit according to the temperature of the fixing member and a temperature of the pressing member before the fixing member rotates.

Abstract: A fixing device including a fixing member, an opposing member, a plurality of heat sources, and a voltage detector. The opposing member is disposed opposite the fixing member to contact the fixing member to form a nip portion at which an unfixed image on a recording medium is fixed. The plurality of heat sources heats the fixing member. The voltage detector detects an applied voltage of at least one of the plurality of heat sources. Upon detection of the applied voltage of the heat sources by the voltage detector, a voltage is applied to at least one of the heat sources.

Abstract: A method of controlling a printing job of an image forming apparatus having an image forming unit. The method of controlling a printing job includes transforming scanned data into printable data, and determining a time to start driving the image forming unit according to the type of data scanned, starting driving the image forming unit at the determined start time, and printing the scanned data transformed into printable data. The time required to perform a printing job is thereby reduced, and scanned data can be output normally.

Abstract: A fixing apparatus includes a film, a heater that contacts the inner face of the film and is capable of changing heat distribution, and a pressure member that forms the nip portion with the heater via the film, the pressure member including a region on which a diameter is increased from a center portion toward an end portion, wherein the fixing apparatus performs heater control so that a ratio of an amount of heat generation at the end portion of the heater to an amount of heat generation at the center portion of the heater is changed based on a temperature of the end portion of the pressure member, during a period at least from when the warm-up of the fixing apparatus is started until the recording material reaches the nip portion.

Abstract: An image forming apparatus having a normal mode and a standby mode includes an image forming unit to form an image, a switching unit which selectively allows power to be supplied to the image forming unit, a controller to control the switching unit based on a phase signal of the power, a power cut-off unit which cuts off the power to the image forming unit in the standby mode, and a phase detector which is connected to both ends of the power cut-off unit, detects a phase of the power via different phase detection routes according to whether being in the normal mode or in the standby mode, and outputs the phase signal of the power so that a power consumption of the image forming apparatus does not exceed a predetermined value in the standby mode.

Abstract: An image reading apparatus includes a feeder, a first reading unit, a first memory which stores image data of the surface of the document read by the first reading unit, a second reading unit located at an upstream side of the first reading position, a second memory which stores image data of the document read by the second reading unit and a controller configured to control the feeder, the first reading unit and the second reading unit. The controller controls to execute pre-scanning the document by the second reading unit over a predetermined range shorter than a separation distance between the first reading position and the second reading position in a transporting direction from a leading edge of the document when the document reaches the second reading position. The controller further controls to execute storing obtained pre-scanned image data into the second memory and measuring the size of the document based on the pre-scanned image data stored in the second memory.

Abstract: The multifunction peripheral registers (i) function information indicative of a type of function executed in a past cooperative process in cooperation with an application and (ii) a URL which was being set when an execution start instruction on the function was received from the application so that the function information and the URL are associated with each other. In a case where (i) a first URL, which is identical to a second URL which is currently set, is registered and (ii) a function indicated by function information associated with the first URL requires a warm-up, a device control section starts the warm-up of, an image forming section.

Abstract: A method and an apparatus to control power supplied to a heating roller and a phase control circuit corresponding to the method or the apparatus. The phase control circuit may include an examination unit to compare levels of a sine wave having a predetermined first period and a switching signal to increase and decrease repeatedly according to a predetermined second period, and a phase control signal generation unit to generate a phase control signal having a non-zero in intervals of time sections including a time when levels of the switching signal and the sine wave which is in a decreasing section are equal to each other during a time period when the level of the sine wave is zero, and a time when levels of the switching signal and the sine wave which is in an increasing section are equal to each other during a time period when the level of the sine wave is zero.

Abstract: When electric power supply is started in response to a power switch being turned on, a control unit determines whether a stored operation mode is a normal mode or a power saving mode with reference to the stored operation mode. More specifically, the control unit determines whether a digital multifunction peripheral is set to operate in the normal mode or the power saving mode before electric power supply to the digital multifunction peripheral is stopped. If the set operation mode is the normal mode, the control unit controls the digital multifunction peripheral to operate in the normal mode. If the set operation mode is the power saving mode, the control unit controls the digital multifunction peripheral to operate in the power saving mode.

Abstract: An image forming apparatus is configured to be able to switch a target temperature of an image heating member from a standby target temperature during a standby state in which a pressurizing member is separated from the image heating member to a first target temperature or a second target temperature which is lower than the standby and first target temperatures. The image forming apparatus controls a contacting/separating mechanism such that a time from when an image forming signal is input until when the pressurizing member in the standby state contacts the image heating member and forms a nip is shorter in a case when the target temperature of the image heating member is the second target temperature than in a case when the target temperature of the image heating member is the first target temperature.

Abstract: An image forming apparatus includes an image forming station for forming an unfixed image on a recording material; a fixing portion for heating and fixing an unfixed image formed on the recording material, the fixing portion including a fixing rotatable member, and a pressing roller cooperative with the fixing rotatable member to form a nip for nipping and feeding the recording material; an ambient condition sensor for detecting an ambient temperature and an ambient humidity; and a controller for controlling the fixing portion; wherein the controller sets such a warming-up time for warming up the fixing portion that a temperature of the pressing roller at the time when the recording material enters the nip is a temperature calculated on the basis of the ambient temperature and the ambient humidity.

Abstract: An induction heating type fusing device to reduce the size of an induction coil and an image forming apparatus having the same, and a control method thereof. The image forming apparatus includes a printing device to form an image on a recording medium, and a fusing device to fix the image to the recording medium. The fusing device includes a heating member arranged to transfer heat to the recording medium and having a main heater and a sub heater, and an induction coil having a width equal to or less than a width of the recording medium and arranged in an axial direction of the heating member to generate a magnetic field acting on the main heater. The sub heater is arranged inside the heating member to heat both ends of the main heater.

Abstract: An image heating apparatus includes an endless belt having a heat generation layer; a driving rotatable member forming a nip; a pressing pad for pressing the endless belt toward the driving rotatable member; an electric energy supply device for supplying electric energy to the heat generation layer; and a shut-off element configured to break electric connection between the electric energy supply device and the heat generation layer when a temperature of the endless belt reaches a predetermined upper limit temperature, wherein the shut-off element is disposed contacted with the endless belt in a region, with respect to a widthwise direction of the endless belt, outside a passing region of a maximum width of the sheet usable with the apparatus and inside of a heat generating region of the heat generation layer.

Abstract: In a case where a process is carried out with respect to an envelope in a fixing process mode, at least either (i) a set temperature of a fixing roller in a fixing process or (ii) a set temperature of an endless belt in the fixing process which endless belt is provided in an external heating device is changed in accordance with a time period between an end of a warm-up mode and a start of the fixing process mode. This makes it possible to prevent both a wrinkle and inadequate fixing in a fixing process of an envelope carried out by a fixing device of an external heating method.

Abstract: An image forming apparatus including a heating rotating body (first body) and a pressurizing rotating body (second body) disposed in a pressure contact state, and commencing image forming when a temperature of the first body reaches a predetermined temperature lower than a fixing temperature. The apparatus acquires a value indicating a temperature of the second body upon commencement of warm-up, and when the value is below a threshold value, heats the first body until the temperature thereof reaches the fixing temperature while rotating the two bodies at a first speed, and when the value equals or exceeds the threshold value, heats the first body until the temperature thereof reaches the predetermined temperature while rotating the two bodies at a second speed slower than the first speed and further heats the first body until the temperature thereof reaches the fixing temperature while rotating the two bodies at the first speed.

Abstract: An image forming capable of operating with reliability and shortening the down time. An operation unit forms an image. A power source unit supplies electric power supplied from an external power source to the operation unit. A storing unit stores successful data which shows that the image forming apparatus has started successfully. A mode selection unit selects a first mode in which regular electric power is supplied to the operation unit at a start-up when the storing unit stores the successful data, and a second mode in which electric power smaller than the regular electric power is supplied to the operation unit at the start-up when the storing unit does not store the successful data. A power control unit controls the electric power supplied from the power source unit to the operation unit according to the mode selected by the mode selection unit.

Abstract: When a printer starts a printing operation using a rolled sheet having IC chips, it is determined whether an error occurred while an IC chip writing device writes information to the IC chips. First page information specifying a page region in which an error occurred and second page information specifying a page region which has been subjected to the printing operation using the printer at a time of occurrence of the error are transmitted to a host computer. Then, recovery information generated using the host computer is obtained, and a print restarting position of a recording medium is controlled so that an information writing position at the time of occurrence of the error corresponds to a position in which the printing operation is restarted. Thereafter, the printing operation is restarted from the printing restarting position in accordance with the recovery information.

Abstract: An image forming apparatus includes a fuser that fuses a paper medium and a fuser control device that controls an AC power supplied to the fuser. The fuser control device includes a phase detecting device that receives an AC voltage, detects zero-crossing points of the AC voltage, outputs a phase detecting signal when the zero-crossing points are detected, and selectively cuts off a flow of AC power into the phase detecting device in response to a mode control signal, a signal generator that generates a phase control signal to control a phase of the AC power supplied to the fuser based on the phase detecting signal, and a temperature controller that controls a temperature of the fuser by controlling the phase of the AC power supplied to the fuser according to the phase control signal.

Abstract: A fixing device to perform a fixing process includes an endless, rotatable belt member; a nip-forming rotary member disposed outside a loop of the belt member; a fixing roller disposed at a backside of the fixing nip inside the loop of the belt member and around which the belt member is rotatably stretched; a heater to heat the belt member at a position different from a position where the belt member is rotatably stretched around the fixing roller; a temperature detector; a memory device to store an operational history of the heater; and a processor operatively connected to the heater to control the heater, before the recording sheet is passed through the fixing nip, to perform a warming-up operation to raise a temperature of the fixing roller at the backside of the fixing nip based on the operational history of the heater stored in the memory device.