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.

Abstract: A fixing device includes a fixing member, a heating member to heat the fixing member, a pressing member to press against the fixing member with a predetermined pressure, forming a nip where an image is fixed on a recording medium with heat and pressure, a heating controller to cause the heating member to heat the fixing member to a predetermined temperature set in advance and to preheat the fixing member while maintaining the temperature of the fixing member, a recording-medium data receiver to acquire recording-medium data before a fixing process is started, and a preheating-time adjuster to adjust a preheating time during which the heating member preheats the fixing member based on the data acquired by the recording-medium data receiver.

Abstract: An image forming apparatus and a method of driving the same are provided in which, if a driving environment is determined to be a low temperature environment, a driving load of an image forming unit is decreased by repeating driving and stopping a driving motor under a high load driving condition to generate a torque higher than a torque generated under a normal warm-up driving condition; and a warm-up operation is performed by driving the driving motor under the normal warm-up driving condition.

Abstract: An image forming apparatus has an image forming station for forming an image and a display unit for displaying specified information. A mode changing section switches a mode of the image forming apparatus between a first mode for waiting on standby with a first power consumption and a second mode for waiting on standby with second power consumption lower, than the first power consumption. A determining section determines whether an image can be formed after the mode is switched from the second mode to the first mode and a starting section starts the display unit when the determining section determines that no image can be formed. A notifying section generates a display on the display unit of information indicating that no image can be formed.

Abstract: A device and method for controlling the initiation of an image forming apparatus are provided using a NAND flash memory. The device for controlling initiation of an image forming apparatus includes: a NAND flash memory for storing a boot program and system control programs for initiating the image forming apparatus; a random-access-memory (RAM) for temporarily storing an execution program and data; and a driving unit arranged to first read the boot program and an engine control program among the system control programs from the NAND flash memory, execute the boot program and the engine control program, then read remaining system control programs from the NAND flash memory and store the remaining system control programs in the RAM when the boot program and the engine control program are being executed.

Abstract: A fixing device is operable through start-up and warm-up stages and has a rotatable fixing member to fix an unfixed toner image borne on a recording medium, an opposing member to press against the fixing member and form a nip on the fixing member, a temperature detector to detect temperature of the fixing member, and a heater controlled in accordance with the temperature of the fixing member to heat the fixing member. The heater is further controlled during the warm-up stage in accordance with at least one of if the fixing member is rotating and if the detected temperature has ever arrived at a prescribed target temperature in the warm-up stage.

Abstract: When a rotation member stops rotation, driving of a plurality of heating elements is sometimes partially be limited. A control unit detects a current flowing to the plurality of heating elements when the rotation member stops rotation, and driving of the plurality of heating elements is partially limited. The control unit sets the power ratio of powers to be supplied to the plurality of heating elements during a period the rotation member rotates to raise a fixing device to a fixing enable state in accordance with the detection result.

Abstract: A fixing device which can prevent deterioration and breakage of each member, and an image forming apparatus having the fixing device are provided. A separation/contact mechanism carries out separation/contact operation of an external heating section with respect to a fixing roller by turning the whole external heating section using a central axis of a rotation supporting roller out of a pair of rotation supporting rollers, as a rotation axis. This constitution can decrease impact force generated at the time of pressure-contact, and can prevent deterioration and breakage of the external heating belt and the fixing roller. Furthermore, when a heater lamp is provided in only the rotation supporting roller, positional deviation and damage of the heater lamp can be prevented.

Abstract: A fixing device includes a rotary, endless fuser belt, a heater, a thermometer, and a controller. The fuser belt is subjected to heating, on which the recording medium is conveyed to fuse the toner image thereon. The heater is located adjacent to the fuser belt for heating the belt. The thermometer is located adjacent to the fuser belt to detect an operational temperature of the belt. The controller is operatively connected to the thermometer and the heater to deactivate the heater upon detecting an abnormal condition in which the operational temperature detected remains below a setpoint temperature after lapse of a warm-up time limit since activation of the heater. The controller includes a historical data recorder and a processor. The historical data recorder records historical usage data of the fixing device since installation. The processor adjusts the warm-up time limit according to the historical usage data recorded.

Abstract: An image forming apparatus prevents the occurrence of the combinations of output wave numbers which are ineffective to suppress flicker in a case where a set heater temperature is significantly reduced. If the set temperature is significantly reduced from 200° C. to 130° C., for example, so that the reduced temperature does not require current to be applied to a ceramic heater, which can occur at the time of starting reverse conveyance of the recording sheet in the double-faced printing mode, temperature control is temporarily suspended and the output wave number of power controlled by a controller is varied to 0 waves based on the previously set combinations of 12, 10, 4 and 0 waves, for example, if the output wave number is varied from 12.

Abstract: An image forming apparatus includes a counting section, a storage section, a control section, and a driving member control section. The counting section counts the number of recording media subjected to successive printing. The storage section stores the number counted by the counting section. The control section performs a control process including: setting a power saving mode by selecting a printing speed of the fixing section which is lower than a preset normal speed used in the normal mode while selecting a preset fixing temperature of the fixing section which is lower than a preset normal temperature used in the normal mode when the normal mode is alive while a frequency of successive printing on not more than three recording media is a predetermined percentage or more. The driving member control section switches a current printing speed of the fixing section to a printing speed selected by the control section.

Abstract: A fixing device having a fixing belt which satisfies 42.2?ER?0.1044×D×??0.5174, where: D represents an inner diameter of the fixing belt; A represents a second inner diameter of the fixing belt; ER represents an elongation rate of the fixing belt and is formulated as ER=(A?D)/D×100; and ? represents a coefficient of kinetic friction between the fixing belt and the fixing roller. The fixing device is thus arranged so that the fixing belt is driven by the fixing roller to rotate in a state where the pressing roller is separated from the fixing belt. This makes it possible to lengthen a life of a fixing belt, to shorten a warm-up time, and to reduce power consumption in a fixing device using a belt fixing method.

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

Abstract: An image forming apparatus includes an image forming unit having image forming elements and a fixing unit. The image forming elements includes an image carrier, a charging unit, a developer carrier, and a developer supplier. The image forming apparatus further includes a post unoperated period image formation preparation processor operable to, when the unoperated period, which is a time period from an end of an image forming operation to a start of a subsequent image forming operation is equal to or greater than a threshold, perform an idling operation to rotate the image carrier while applying a post unoperated period image formation preparation voltage, which is different from a normal image formation voltage, to a given one or more of the image forming elements.

Abstract: A fixing device includes a heating roller which is heated by a heater, a pressure roller which comes into contact with a fixing belt to form a nip portion, and a thermopile capable of measuring a surface temperature of the fixing belt. The fixing device moves that portion on the surface of the fixing belt which was located at the nip portion with the pressure roller at the start of a warm-up operation, to a measurement location of the thermopile. The fixing device uses the thermopile to measure the temperature of that portion on the surface of the fixing belt moved to the measurement location. The fixing device controls the warm-up operation on the basis of the temperature measured by the thermopile. This can reduce the time required for the warm-up operation.

Abstract: A fixing control device includes a power distribution controller that adjusts a power distribution time period when the power is distributed to plural heater elements per control cycle, a turn on time determining member that determines a time when each of the plural heater elements is turned on based on a duty ratio between the power distribution time period and the control cycle, and a soft operation controller that either gradually starts or stops heating each of the plural heater elements during a soft start or stop period, respectively. One of the soft start and stop periods for one of the plural heater elements is decreased not to overlap with another one of the plural heater elements.

Abstract: An image forming apparatus, for which a heated roller fixing device is employed but for which a savings in power can still be obtained, is provided. The image forming apparatus includes: a fixing device, which is a heated roller fixing device that requires pre-heating in a stand-by state; an operation panel, with which a power-saving mode transition time period can be changed; and a control part, which selects pre-heating or does not select pre-heating of the heated roller fixing device. The control part employs the power-saving mode transition time period, entered at the operation panel, to change the pre-heating or to not change the pre-heating of the heated roller fixing device.

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: A fixing device includes a fuser member, a heater, a thermometer, and a power supply controller. The fuser member is subjected to heating. The heater is adjacent to the fuser member to heat the fuser member. The thermometer is adjacent to the fuser member to detect an operational temperature of the fuser member. The power supply controller controls power supply to the heater by adjusting a duty cycle. The controller includes a duty cycle calculator, a driver circuit, and a duty cycle modifier. The duty cycle calculator is operatively connected to the thermometer to calculate a primary value of the duty cycle based on the operational temperature. The driver circuit is operatively connected to the duty cycle calculator to supply power to the heater according to the duty cycle. The duty cycle modifier is connected between the duty cycle calculator and the driver circuit to modify the duty cycle.

Abstract: An image forming apparatus includes a control mechanism capable of selecting a plurality of print modes and a fixing device fixing an image developed based on one of the print modes selected by the control mechanism. The control mechanism selects any one of the print modes based on a successive print sheet number determined by print information received from a host device and a power consumption amount of each of the print modes calculated from fixing temperature of the fixing device prior to starting print operation.

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: The non-sheet-feeding portion temperature rise is reduced during warm-up operation of an image heating apparatus, the time needed for the warm-up operation is reduced, and the accuracy of the image fixing operation is improved. When a CPU determines that a temperature detected by an end portion thermistor is higher than a temperature detected by a center portion thermistor, the CPU controls the temperature of a fixing heater based on a detection result of the end portion thermistor. When the CPU determines that the temperature detected by the end portion thermistor is equal to or less than the temperature detected by the center portion thermistor, the CPU controls the temperature of the fixing heater based on a detection result of the center portion thermistor.

Abstract: An image forming apparatus includes a photosensitive member driving part that drives a photosensitive member, a counting part that carries out an adding operation when the photosensitive member driving part drives the photosensitive member, and carries out a subtracting operation when the photosensitive member driving part stops the photosensitive member; and a control part that interrupts, when a count value of the counting part becomes equal to or more than a first predetermined value, a printing operation of driving the photosensitive member, forming an electrostatic latent image on the photosensitive member, and fixing a toner adhering to the photosensitive member onto a recording sheet, and causes the counting part to start the subtracting operation.

Abstract: To control a cooling fan to cool a fusing unit of an image forming apparatus, it is determined whether the fusing unit is turned on or off. If the fusing unit is determined to be turned on or off, it is determined whether a condition to turn the cooling fan on or off is satisfied. If the cooling fan on/off condition is satisfied, the cooling fan is turned on or off. Thus, the driving of the cooling fan is minimized when the driving of the cooling fan is unnecessary so that the cooling fan is driven at a high efficiency.

Abstract: A fixing device according to an embodiment of the present invention heats a metal conductive layer of a heat roller using an induction current generating coil. In order to supplement a heat capacity of the heat roller, a press roller having a large heat capacity is heated by a halogen lamp. During a start of activation of an image forming apparatus, when a printer control circuit is started, the supply of electric power to the halogen lamp is started before warming-up is started.

Abstract: Provided is an image forming apparatus having a network connecting portion, a control portion, and a status information storage portion. When a status request is sent from an external apparatus while the image forming apparatus is in a power-saving status, based on a condition set by a setting portion, the control portion makes a determination of whether (a) to perform supply of power to the main body of the image forming apparatus and acquire a status information to transmit it through the network portion or (b) not to perform supply of power to the main body of the image forming apparatus, but to transmit through the network portion a status information that has been stored in the status information storage portion before the status request, and performs controls based on the determination.

Abstract: In a fixing apparatus provided with a plurality of fixing heaters having heat distribution characteristics that are different from each other inside a fixing roller, and an image forming apparatus provided with the fixing apparatus, an auxiliary heater is provided, the auxiliary heater being provided inside the fixing roller and to which power is distributed only during the warm-up period until the fixing roller in a lower temperature state reaches a predetermined fixing temperature. The plurality of fixing heaters includes a first fixing heater having first heat distribution characteristics that mainly heats a center portion of the fixing roller, and a second fixing heater having second heat distribution characteristics that mainly heats both end portion regions of the fixing roller.

Abstract: A temperature control apparatus includes a temperature sensor which detects a temperature of a heating element, a controller for controlling heat generation of the heating element in accordance with a detected temperature by the temperature sensor, and a monitoring circuit which monitors the detected temperature, and stops operation of the controller in a predetermined stop period defined on the basis of the detected temperature when a predetermined operation mode of plural operation modes is set.

Abstract: The present invention relates to a method and a control system for driving a three-strand brushless, electronically commutated electric motor (2), wherein a line AC voltage (UN) is rectified and fed via a slim DC link (8) with minimum DC link reactance as a DC link voltage (UZ) to an inverter (10) that can be driven to supply and commutate the electric motor (2). A pulsating DC voltage (UG) initially generated by rectifying the line AC voltage (UN) is dynamically increased with respect to its instantaneous values by a step-up chopper (18) in such a manner that the resulting DC link voltage (UZ) with a reduced ripple always lies above a defined limit voltage (U18/U1) over time. The control system consists of a network rectifier (6), a downstream slim DC link (8) with minimum DC link reactance and a controllable inverter (10) that can be supplied via the DC link and driven to commutate the electric motor (2).

Abstract: A fixing rotational body is rotated immediately before shifting from a standby mode to a power saving mode in which not only power supply to a heater and the rotation of the fixing rotational body are stopped but also a timer is stopped so that the reliability of the thermistor detection temperature when returning from the power saving mode is improved, and fixing defect is prevented while power consumption in the power saving mode is reduced.

Abstract: An image forming apparatus and a method of controlling a fusing unit thereof are provided. The method includes: detecting a present mode of the image forming apparatus; selecting a waveform number control to control an electric power source which is supplied to the fusing unit when the present mode is a standby mode; and supplying the electric power source to one of a plurality of heat generating members depending on the waveform number control to prevent the plurality of heat generating members from being simultaneously supplied with the electric power.

Abstract: A belt fuser assembly for a color EP printer that quickly warms up the fusing belt before allowing a first sheet of print media to run through the printing stations at the fuser assembly. The warm-up cycle includes: (1) a preheat mode, (2) a first portion of a belt temperature warm-up mode, (3) a second portion of the belt temperature warm-up mode, and (4) a tight belt temperature control mode. The preheat mode operates the fuser's heater at less than full power, and prevents the fuser belt from rotating. The first portion of the belt temperature warm-up mode operates the heater at full power, and the fuser belt begins rotating, but not at its full speed. The second portion of the belt temperature warm-up mode operates the heater at less than full power, and the fuser belt begins rotating at its full speed.

Abstract: An image forming apparatus includes a power supply unit that controls a level of electrical power supplied to the heating lamp during a warm-up of the heating unit that involves at least a first warm-up stage. During the first warm-up stage, when power begins to be supplied to the heating lamp, the power supply unit gradually increases a level of power supplied to the heating lamp from zero to a defined supply level according to a phase control of an alternating current (AC) of the source power. If a second warm-up stage is included, during the second warm-up stage, the power supply unit may maintain the level of power supplied to the heating lamp at the defined supply level until the measured surface temperature of the heating unit has reached a defined target temperature.

Abstract: An image forming apparatus comprises an image information obtainer that obtains image information, a gradation sequence processor that applies multiple types of gradation sequence processing to the image information, and a toner image formation device that forms a toner image based on the image information. A fixing device is provided to fix the toner image onto a recording medium in a fixing process. A temperature controller is also provided to change a start-up temperature of the fixing device before the fixing process. The start-up temperature is changed in accordance with inclusion of a halftone process and a type of the gradation sequence processing applied to the image information.

Abstract: An image forming apparatus includes a fixing roller, a heating section, a pressurizing roller, an oil roller, a first cleaning roller, and a control section. The pressurizing roller is pressed against the fixing roller. The oil roller abuts against the fixing roller and is capable of being rotated by rotation of the fixing roller to apply oil onto a surface of the fixing roller. The first cleaning roller abuts against the oil roller and is capable of being rotated by rotation of the oil roller to clean a surface of the oil roller. When the control section determines that the fixing roller and the pressurizing roller have performed fixing on a predetermined number and more of consecutive sheet surfaces, the control section carries out a first control process which causes the heating section to stop and the fixing roller to rotate for a first predetermined time period after the fixing.

Abstract: An image-forming device, such as a laser printer, includes a sheet-feed section, an image-forming section, a thermal fixing section and a control section. The sheet-feed section is configured to feed a recording sheet to a conveyance path. The image-forming section is disposed along the conveyance path and configured to form a toner image on the recording sheet. The thermal fixing section is disposed downstream of the image-forming section in a direction of sheet feeding and configured to fix the toner image on the recording sheet with a predetermined temperature. The control section is configured to control the temperature of the thermal fixing section, to detect a sheet-feed error in the sheet-feed section and to output an error signal indicative of the error occurring. The control section may further be configured to change the temperature of the thermal fixing section in response to the error signal.

Abstract: The present invention relates to an image forming apparatus that minimizes the consumption of power during physical formatting of the hard disk drive or the deletion of data therefrom and to a control method thereof. The image forming apparatus has a non-volatile storage unit that stores image data and a controller that executes at least one of the operations of initialization of the storage unit and deletion of the image data stored in the storage unit, and further includes as operating modes an image forming mode during which image formation is enabled and a power-saving mode during which power consumption is minimized, wherein the controller switches the operating mode to power-saving mode when initialization processing or image data deletion processing is begun.

Abstract: An image forming apparatus for performing a copier job and a printer job includes a controller operatively connected to a fixing rotary body heater and a pressing rotary body heater to control the fixing rotary body heater and the pressing rotary body heater. The controller activates a standby mode after the copier job and the printer job are finished in which the controller turns off at least the fixing rotary body heater and a subsequent off mode in which the controller turns off the pressing rotary body heater and the fixing rotary body heater, and identifies which of the copier job and the printer job is to be performed to turn on and off the pressing rotary body heater in the standby mode according to the identified job.

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: A method and apparatus for saving power in an image production device is disclosed. The method may include determining if the image production device has been inactive for a predetermined period of time, wherein if it is determined that the image production device has been inactive for a predetermined period of time, decreasing a fuser fan's output by a predetermined amount, decreasing a fuser lamp setting by a predetermined amount, the fuser system being heated to operate at a temperature that is at a first predetermined level, setting a timer, determining if the fuser system's temperature is at a second predetermined level, wherein if it is determined that the fuser system's temperature is not at the second predetermined level, determining if the timer expired, wherein if it is determined that the timer expired, decreasing a fuser lamp setting by the predetermined amount and resetting the timer.

Abstract: An image forming apparatus includes an imaging section and a thermal fixing device. The fixing device fuses a toner image formed by the imaging section onto the recording sheet passing through a fixing nip. The fixing device includes a fixing member, a pressure member, a heater, a temperature sensor, and a temperature controller. The fixing member is rotatable, and the pressure member is pressed against the fixing member to form the fixing nip therebetween. The heater heats at least a portion of the fixing member. The temperature sensor senses a temperature of the fixing member. The temperature controller controls the temperature of the fixing member in at least one of an on-off mode and a PID mode. The temperature controller initially operates in the on-off mode upon entering recovery, and switches to the PID mode when a threshold time has elapsed after entering recovery.

Abstract: A printer having operational modes including a sleep mode, includes, an operation display unit, a sleep-mode setting-value table in which a warm-up time from the sleep mode and an estimated amount of power consumption per certain unit of time in the sleep mode are stored in association with values for setting items to set up conditions of the sleep mode, and a first setup unit. The first setup unit is configured to, when setting up the conditions of the sleep mode, extract the estimated amount of power consumption and the warm-up time in reference to the sleep-mode setting-value table by using, as a key, values of the setting items inputted through the operation display unit, and display the extracted estimated amount of power consumption and warm-up time in the operation display unit.

Abstract: An image heating apparatus has a coil; a rotatable image heating member capable of generating heat by a magnetic flux generated by the coil to heat an image; a temperature detecting member; an electric power supply controller for controlling electric power supply to the coil; and an execution portion for executing a stand-by mode operation in which the image heating member is at rest, and the apparatus waits for input of an image formation signal while the electric power supply controller carries out its power supply control operation such that in the stand-by mode, along no longitudinal line on said image heating member, the temperature of the image heating member exceeds Curie temperature on an entirety of the longitudinal line.

Abstract: A fixing device includes a fixing rotation body heating and fixing an unfixed image onto a recording medium; a pressing rotation body pressing the recording medium to the fixing rotation body; a first temperature detection unit detecting a temperature of the fixing rotation body; and plural second temperature detection units detecting a temperature of the pressing rotation body. Further the fixing device selects a predetermined second temperature detection unit from the plural second temperature detection units depending on an operation mode of the fixing device, and the fixing device detects the temperature of the pressing rotation body by using the predetermined second temperature detection unit selected by the fixing device.

Abstract: An apparatus and method for image fixing are disclosed. A fixing device includes a fixing member, a pressure member, a heater, and a pressure controller. The fixing member and the pressure member face with each other to form a nip. The heater heats a surface of the fixing member when the fixing member rotates. The pressure controller changes a pressure generated at the nip, according to an operation of the fixing device.

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

Abstract: The image forming apparatus includes: an image former which, upon receiving a first instruction, feeds a sheet and performs an image forming operation to form an image on the sheet; a fixing part which (i) secures a fixing nip by bringing outer circumferential surfaces of first and second rotating bodies into contact with each other, (ii) upon receiving a second instruction, heats the first and second rotating bodies until a temperature thereof reaches a target temperature, and (iii) thermally fixes the image onto the sheet passing through the fixing nip; and a determiner which determines output timings of the first and second instructions such that a timing at which a leading end, in a sheet convey direction, of the image formed on the sheet reaches the fixing nip and a timing at which the temperature of the first and second rotating bodies reaches the target temperature match each other.

Abstract: An image forming apparatus operates in a power saving mode or in the normal printing mode. An image forming section forms an image in accordance with print data received from an external apparatus. A state detecting section detects a state of the image forming apparatus. A controller causes the image forming apparatus to enter into a power saving mode where the controller terminates supply of electric power to a section of the image forming apparatus that consumes a large electric power. A data detecting section detects whether the print data exists in the image forming apparatus. When the state detecting section detects a change in the state of the image forming apparatus and the data detecting section fails to detect print data in the image forming section, the controller causes the image forming apparatus to enter the power saving mode.