Abstract: A power supply device includes a first switch section that can disconnect a 24-V power supply from a commercial alternating-current (AC) power supply and that operates with the voltage of 3.3 V, and a second switch section that can disconnect a voltage detection circuit from the commercial AC power supply and that operates with the voltage of 3.3 V. When a power saving mode is on, the 24-V power supply and the voltage detection circuit are disconnected from the commercial AC power supply by using the first and second switch sections, whereby the power supply device can be used in areas where different supply voltages are used, and at the same time reduction in power consumption in the power saving mode is achieved.

Abstract: A high voltage power supply (HVPS) without an output voltage adjustment, a method of adjusting an output voltage of a HVPS, and an image forming apparatus using the method are provided. The image forming apparatus includes a high-voltage output unit that outputs a high voltage produced by the HVPS, a tag that stores an offset voltage information and is attached to the HVPS, and a high-voltage output control unit that reads the tag attached to the HVPS to extract the offset voltage information, and corrects a high-voltage output control signal by using the offset voltage information to change the high voltage output by the high-voltage output unit. Accordingly, a process of adjusting an output voltage of an HVPS as a single component is not required. The manufacturing costs of HVPSs are reduced, and the process of finely adjusting an output voltage of the HVPS is simplified.

Abstract: A power supply includes a first capacitor, a resistor for discharging an electric charge of the first capacitor and for detecting zero crossing of the AC voltage input from the AC power supply, a second capacitor, and a frame ground o and a discharge resistor having a resistance value smaller than the resistor and configured to discharge an electric charge of the second capacitor, and switches between a state where a current to the discharge resistor is cut off and a state where a current flows through the discharge resistor.

Abstract: A developing unit develops a latent image with a developing agent. A supply unit supplies, to the developing unit, a developing alternating current bias voltage with a waveform having a pulse period during which a rectangular wave is output and a blank period during which no rectangular wave is output. An input signal generation unit generates, as an input signal be supplied to a primary side of a transforming unit that forms the developing alternating current bias voltage, an input signal obtained by adding an additional pulse smaller in width than the rectangular wave in the pulse period at a timing to transit from the pulse period to the blank period.

Abstract: A power control method for supplying AC power to a first load and a second load is provided. The method includes supplying, to the first load, AC power corresponding to a range of a phase angle 0 to a phase angle ?1 in each half cycle; and supplying, to the second load, AC power corresponding to a range of a phase angle ?2 to a phase angle ? in each half cycle, wherein ?1 is larger than 0 and not more than ?, ?2 is not less than 0 and smaller than ?, and ?1 is larger than ?2.

Abstract: An image reading apparatus includes a sheet feeding unit configured to sequentially feed documents loaded on a document positioning plate, a reading sensor configured to read a document of the plurality of documents fed by the sheet feeding unit, an acquisition unit to acquire an interval of the document between a trailing edge of a preceding document and a leading edge of a next document conveyed through the conveyance path, and a reading unit to execute a first reading mode using the reading sensor to read the document conveyed at a first conveyance speed, and a second reading mode using the reading sensor to read the document conveyed at a second conveyance speed that is lower than the first conveyance speed, wherein the reading unit executes the second reading mode after the first reading mode when the interval of the document is less than a predetermined interval.

Abstract: A printing apparatus/method includes at least one processor, at least one printing engine, and at least one graphic user interface all operatively (directly or indirectly) connected to each other. The graphic user interface has at least one display and at least one user input device. The display provides at least one menu having at least one user selectable parameter of the printing engine. The display provides at least one linear scale bar representing a range of values to which the selectable parameter can be set. The display provides at least two different graphic icons along the linear scale. The graphic icons conceptually represent different performance characteristics that the printing apparatus will have when the selectable parameter is set to different values along the range of values represented on the linear scale. The display can also provide numerical performance values adjacent each of the different graphic icons.

Abstract: Disclosed is an image forming device including an engine unit that performs image processing; an engine control unit that controls the engine unit; and a controller that generates items of starting information. The controller transmits a first item of the starting information indicating a cause of the starting process, and transmits a second item of the starting information when a content of the second item of the starting information is fixed. A time period required for fixing the second item of the starting information depends on the cause of the starting process. The engine control unit obtains the second item of the starting information, based on the first item of the starting information and timing information obtained in advance that indicates a timing at which the second item of the starting information is expected to be fixed.

Abstract: A printing apparatus includes an input unit configured to input a print job, a print unit configured to perform print processing onto a print medium based on the print job input by the input unit, a receiving unit configured to receive a request for shutting off power supply of the printing apparatus, an execution unit configured to execute processing for shifting to a state where power supply of the print unit can be shut off, in response to the fact that the request has been received by the receiving unit, and a control unit configured to perform control, if a request for shutting off a power supply of the printing apparatus is received by the receiving unit, to prevent the print processing based on the print job from being executed, and on the other hand, to permit execution of processing based on another job different from the print job.

Abstract: A constant current-type high-voltage power supply apparatus which is used in an image forming apparatus includes a leakage current detection unit that detects a leakage current leaked from at least one output terminal of the constant current-type high-voltage power supply apparatus and outputs the detected leakage current, a direct current voltage output unit that outputs different direct current (DC) voltages according to whether the leakage current detected by the leakage current detection unit is input, and a power control unit that controls power supply to the constant current-type high-voltage power supply apparatus according to the output DC voltage.

Abstract: A power supply device controls drive of a synchronous rectification switch unit by converting a voltage into a current, and comparing a voltage obtained by current-to-voltage conversion with a predetermined value.

Abstract: An image forming apparatus is provided. The image forming apparatus includes a plurality of photosensitive members arranged to align in parallel with one another, an exposure device arranged in an upper position with respect to the plurality of photosensitive members and configured to expose the photosensitive members to light, an exposure controller arranged in an upper position with respect to the exposure device and configured to control the exposure device according to inputted image data, a power board, arranged in a lower position with respect to the plurality of photosensitive members and configured to convert alternate current power to direct current power, and a voltage converter arranged in un upper position with respect to the exposure device and configured to convert the direct current power supplied from the power board into an at least single-leveled first voltage and supply the first voltage to the exposure controller.

Abstract: An image forming apparatus has a first unit for performing an image forming process on a sheet, a frame having a first surface facing the first unit and a second surface opposite the first surface. A second unit is mounted on the second surface of the frame and a high-voltage board is mounted on the second surface of the frame with the second unit located therebetween. A connecting mechanism electrically connects the first unit and the high-voltage board to supply high voltage to the first unit. The connecting mechanism includes a unit-side wire extending at a side of the first surface and a board-side wire connectable to the unit-side wire and extending at a side of the second surface. The unit-side wire and the board-side wire are connected with contacts thereof pressed into contact with each other.

Abstract: A high-voltage power supply comprises the following components. A piezoelectric transformer outputs a voltage in accordance with a supplied drive frequency. A rectification part is connected to an output side of the piezoelectric transformer. A drive frequency generating part generates the drive frequency supplied to the piezoelectric transformer. A voltage detection part detects an output voltage of the piezoelectric transformer or the rectification part. A control part controls the drive frequency generating part such that a drive frequency corresponding to the output voltage detected by the voltage detecting part is generated. A first time constant, which is a time constant of the control part, is smaller than a second time constant, which is a time constant of a control target including the piezoelectric transformer and the rectification part. A third time constant, which is a time constant of the voltage detecting part, is smaller than the second time constant.

Abstract: The image forming apparatus includes the control unit controls the potential at a transfer portion of a rotary to be a potential of the same polarity as the charged polarity of the toner at development, when an image forming apparatus starts rotating a photosensitive member, after the start of output by a common power supply and before a charge area on the photosensitive member reaches the transfer portion.

Abstract: An image forming apparatus is provided with a processing unit that performs a predetermined process, a power-supply shutting unit that shuts off power supply to the processing unit when a predetermined door is opened, a voltage detecting unit that detects a decrease in voltage at a point located posterior to the power-supply shutting unit, and a communication control unit that does not initiate communication with the processing unit if the decrease in voltage is detected by the voltage detecting unit before a start of the communication with the processing unit, and judges the just-ended communication as abnormal if the decrease in voltage is detected by the voltage detecting unit after the end of the communication with the processing unit.

Abstract: The image forming device includes a reception unit, an image forming unit, a switching unit, a detection unit, and a charging unit. The switching unit switches the image forming device between a first mode in which the reception unit is not supplied a voltage from a power source, is supplied power from a secondary battery, and receives image forming requests, and a second mode in which the image forming unit is supplied the voltage and performs image forming. The detection unit detects a value of an amount of energy of the secondary battery. In the second mode, the charging unit charges the secondary battery by supplying the voltage to the secondary battery when the value is equal to or less than a threshold value, and the charging unit boosts the voltage and supplies the boosted voltage to the secondary battery when the value is greater than the threshold value.

Abstract: An image forming apparatus is disclosed that includes a power storage unit. The power storage unit includes a constant voltage generation part configured to generate a constant voltage from a commercial power supply, the constant voltage generation part being connected to an external apparatus operating by consuming power; a voltage increasing circuit configured to increase the constant voltage generated by the constant voltage generation part; a capacitor configured to store an electric charge supplied from the voltage increasing circuit; a circuit control part configured to control charging of the capacitor; and an output part configured to output power stored in the capacitor, the power having a voltage different from the constant voltage.

Abstract: An image forming apparatus includes a charging device for performing charging and discharging using a power storage device, and a plurality of loads each serving as a target of power supply from said charging device and being used in operation of the image forming apparatus. The image forming apparatus obtains information about an operation status of the image forming apparatus and sets priorities for being a target of power supply from the charging device for the plurality of loads, according to the obtained information. The image forming apparatus controls power supply operation of the charging device according to the information about the remaining capacity of the power storage device and the set priorities.

Abstract: A power supply system includes a switching power supply. The switching power supply includes an overcurrent detection circuit. The overcurrent detection circuit includes a current detecting resistor, a reference voltage generation circuit, and a comparison circuit. The current detecting resistor is provided on a secondary side of a transformer. The reference voltage generation circuit generates a first reference voltage when an output voltage of the switching power supply is a first output voltage and a second reference voltage lower than the first reference voltage when the output voltage is a second output voltage. The comparison circuit detects an overcurrent by comparing a voltage across the current detecting resistor with the first reference voltage or the second reference voltage.

Abstract: An image forming apparatus that includes a power supply unit to convert AC power input to the image forming apparatus into DC power, a high-voltage power unit to convert the converted DC power to high voltage, an image forming unit to form an image using the converted high voltage, and a controller to control operation of the image forming unit, where the power supply unit, the high-voltage power unit, and the controller are disposed on a single circuit board.

Abstract: A method for monitoring subsystem power includes, with a power control system of an electronic device, receiving energy usage data from one of a plurality of subsystems within the electronic device, with the power control system, maintaining energy usage data for the plurality of subsystems within the electronic device, and with the power control system, providing integrated energy usage data to one of the plurality of subsystems.

Abstract: A converter includes a switching element configured to switch an input voltage, a drive unit configured to drive the switching element, a pulse signal generating unit configured to supply a pulse signal to the drive unit, and a bypass unit configured to connect the switching element and the pulse signal generating unit without involving the drive unit. An operation of the bypass unit maintains the switching element in an on state when the input voltage is switched to a lower voltage and switching of the input voltage is stopped.

Abstract: An image forming apparatus for performing job processing includes a power supplying unit configured to supply power to a heating unit, a cooling unit configured to cool an inside of an enclosure of the image forming apparatus, a power generating unit configured to generate power by heat dissipated from the heating unit, a power storage unit configured to store the power generated by the power generating unit, and a power supply control unit configured to, after driving the cooling unit by the power from one of the power supplying unit and the power generating unit, switch a power source of the cooling unit from one of the power supplying unit and the power storage unit to the power generating unit.

Abstract: A high-voltage power supply to output a plus/minus high-voltage, which is applied to image forming apparatuses, includes a plus high-voltage output unit outputting the plus high-voltage by using a Pulse Width Modulation (PWM) signal, a minus high-voltage operation control unit charging a certain voltage while the plus high-voltage output unit is outputting the plus high-voltage, a minus high-voltage output unit outputting the minus high-voltage by using the certain voltage charged in the minus high-voltage operation control unit, and a minus high-voltage blocking unit to block the output of the minus high-voltage from the minus high-voltage output unit while the plus high-voltage output unit is outputting the plus high-voltage.

Abstract: A power supply device including a transformer having a primary winding and a secondary winding, and a switching element connected to the primary winding configured to drive the switching element to output voltage from the secondary winding includes a control unit configured to drive the switching element such that the switching element is turned on and, in which, in a case where the control unit performs an intermittent drive operation which repeats a period for which the switching element is driven and a period for which the drive of the switching element is stopped, in which the control unit drives the switching element such that the switching element is turned off before the voltage according to the current flowing to the primary winding reaches the voltage output from the secondary winding in the period for which the switching element is driven.

Abstract: An image forming apparatus includes a control board, a first connection terminal provided on an outer surface of the control board, an installation section disposed at the outer surface side of the control board, a substrate capable of being installed into the installation section, a second connection terminal provided on a first surface of the substrate and connected to the first connection terminal, a grip portion provided on a second surface of the substrate at a first end thereof in an in-plane direction, and an external connection terminal provided on the substrate so as to project from the substrate at a second end thereof in the in-plane direction. The external connection terminal is externally exposed to allow an external device to be connected thereto when the substrate is installed into the installation section after the external connection terminal is inserted through an opening in the apparatus body.

Abstract: An image heating apparatus includes an image heating rotational member configured to heat an image on a recording material, a pressure member configured to form a nip portion with the image heating rotational member and pinch the heated recording material in the nip portion, a first external heater including a first heat generation member and configured to contact an outer surface of the image heating rotational member and heat an area of the image heating rotational member that has passed the nip portion, and a second external heater including a second heat generation member and configured to contact an outer surface of the image heating rotational member and heat an area of the image heating rotational member heated by the first external heater. In the image heating apparatus, maximum power applied to the second heat generation member is smaller than maximum power applied to the first heat generation member.

Abstract: An image forming apparatus includes an image carrier and the following elements. A charging unit charges the image carrier. An exposure unit exposes the charged image carrier to light and forms an electrostatic latent image. A developing unit generates a developing electric field and develops the electrostatic latent image. A transfer unit transfers the developed image. A controller outputs an AC setting signal. The developing unit includes a bias power supply source having the following elements. An output transformer includes a primary winding and a secondary winding. A switching circuit supplies a current to the primary winding. A current control circuit includes first impedance and second impedance. The first impedance is set when the AC voltage has a first frequency and the second impedance is set when the AC voltage has a second frequency, thereby controlling a current flowing between the primary winding and the switching circuit.

Abstract: An image forming apparatus includes an image carrier and the following elements. A charging unit generates a charging electric field and charges the image carrier with the charging electric field. An exposure unit exposes the charged image carrier to light and forms an electrostatic latent image on the image carrier. A developing unit generates a developing electric field and develops the electrostatic latent image. A transfer unit transfers the developed image onto a transfer subject. At least one of the charging electric field and the developing electric field is generated by a bias power supply unit including a transformer having a primary winding and a secondary winding, and also including the following elements. A switch circuit supplies a current to the primary winding of the transformer by switching a switching device. A modulator circuit generates a PWM modulation signal. A waveform setting unit sets a waveform of a carrier signal.

Abstract: In a high voltage power supplying apparatus, a pulse generation unit generates a pulse signal with a predetermined frequency. A piezoelectric transformer outputs a voltage in accordance with the frequency of the pulse signal. A detection unit detects an output voltage of the piezoelectric transformer. A control unit controls the pulse generation unit to change the frequency of the pulse signal by a predetermined value towards a frequency corresponding to a target voltage until the output voltage becomes equal to the target voltage. A storage unit stores data indicating the frequency when the output voltage reaches the target voltage. The control unit controls the output voltage to be equal to the target voltage by variably controlling the frequency of the pulse signal by a value smaller than the predetermined frequency from the frequency corresponding to the data stored in the storage unit.

Abstract: An image forming apparatus is provided. The image forming apparatus includes a source, voltage generator to generate a source voltage to provide developing units with a power-supply voltage, a second voltage generator to generate a developing bias voltage applied to a developing roller and a supply bias voltage applied to a supply roller upon receiving the source voltage generated by the source voltage generator, and a switching unit to selectively provide the developing units with different voltage levels generated by the second voltage generator. The apparatus includes a Zener diode installed at a common end, so that a deviation of the developing voltage applied to the developing device affected by a deviation of Zener diode components can be reduced, resulting in an increased color image quality and a reduction in production costs.

Abstract: An image processing apparatus includes a plurality of drive units, a control unit, and an operation information input unit. The plurality of drive units drive based on electric power supplied. The control unit shifts the plurality of drive units to a power saving state or a normal state. The operation information input unit is sequentially input first operation information indicating a start of a process and second operation information indicating a process content. The control unit shifts the plurality of drive units to the normal state when the first operation information is input to the operation information input unit with the plurality of drive units being in the power saving state. The control unit shifts a particular drive unit to the power saving state based on the second operation information when the second operation information is input.

Abstract: An image forming apparatus includes a power supply circuit, at least one motor configured to receive electric power from the power supply circuit, a photosensitive body configured to be rotated by the motor for forming an image on a sheet, a charger configured to charge the photosensitive body, a high voltage generation circuit configured to receive electric power from the power supply circuit and generate a high voltage applied to the charger, and a control device. The control device is configured to determine whether a motor activation condition to activate the motor is satisfied, determine whether a limitation condition to limit a peak of a current output from the power supply circuit is satisfied, and regulate the current flowing through the high-voltage generation circuit if the motor activation condition and the limitation condition are satisfied.

Abstract: A fixing device includes a pressing rotary body pressed against a fixing rotary body to form a fixing nip therebetween through which a recording medium bearing a toner image is conveyed; a heater to heat the fixing rotary body, disposed opposite a circumferential surface of the fixing rotary body and upstream from the fixing nip a predetermined circumferential distance along the circumferential surface of the fixing rotary body in a direction of rotation of the fixing rotary body; a heater driver to turn on and off the heater; a timing calculator to calculate a reference time at which a trailing end portion of the recording medium in a conveyance direction of the recording medium reaches the fixing nip; and a heater driver controller to cause the heater driver to turn off the heater at a turn-off time earlier than the reference time.

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

Abstract: In a first power state of an image forming apparatus in which a first power supply unit supplies power to a network I/F but does not supply power to a central processing unit (CPU), if a received packet is a first type packet, a power supply control unit shifts the image forming apparatus to a second power state in which the first power supply unit supplies power to the CPU but the second power supply unit does not supply power to the image forming unit. If the received packet is a second type packet, the power supply control unit shifts the image forming apparatus to a third power state in which the first power supply unit supplies power to the CPU and the second power supply unit supplies power to the image forming unit.

Abstract: An image forming apparatus comprises: a piezoelectric sensor that produces an variable output signal depending on the amount of infrared energy; a human body detecting device having a lens that forms a detecting area serving for detecting if the person enters; a peak detector that detects a peak of an output signal produced when the person enters the detecting area; an offset voltage judgment portion that judges if the output signal falls to the offset voltage after the peak; a moving direction judgment portion that judges the direction in which the person moves in the detecting area; and a mode controller that switches the power supply mode to a first mode if the power supply mode is found to be a second mode requiring less power than the first mode while the moving direction judgment portion judges that the person moves toward the image forming apparatus.

Abstract: An image reading device is provided, which includes a controller configured to, when a carriage reaches a turn-around position in a moving direction, control a motor to once stop, then rotate in a second direction opposite to a first direction such that a planetary gear swings to a position separated from an output gear and that an intermediate gear moves to an engagement position to engage with the output gear, and thereafter again rotate in the first direction so as to transmit a driving force from the motor to the output gear via an input gear, a planetary gear, and the intermediate gear.

Abstract: An image forming apparatus includes an image bearing member, a transfer member, and a power supply unit that outputs a voltage to the transfer member. The power supply unit includes a first voltage generation circuit that includes a piezoelectric transformer driven at a drive frequency within a predetermined frequency area to output a first voltage having a predetermined polarity, and a second voltage generation circuit that outputs a second voltage with a polarity opposite to the predetermined polarity. In addition, a control unit controls the power supply unit to output a superposed voltage as a voltage having the predetermined polarity and corresponding to a voltage output from the piezoelectric transformer by driving the piezoelectric transformer at a driven frequency out of range of the predetermined frequency area, with the superposed voltage being a voltage in which the first voltage and the second voltage are superposed.

Abstract: An image forming apparatus includes a plurality of developing devices to develop toners of different colors on an image carrier; a power supply to supply the plurality of developing devices with a first voltage to develop the toners on the image carrier; a switching unit to connect the power supply to one of the plurality of developing devices; and a voltage divider to supply some of the other developing devices that are not connected to the power supply with a second voltage to prevent toner development and to supply any other remaining developing device with a third voltage, an absolute value of which is less then an absolute value of the second voltage.

Abstract: An image forming apparatus includes a power supply unit to generate DC power, a plurality of function units to perform the functions of the image forming apparatus, a control unit to control the operation of a plurality of function units, a switching unit to receive DC power of the power supply unit and switch power provided to the control unit and each of a plurality of function units, and a power management unit to receive DC power of the power supply unit and to control a switching operation of the switching unit according to an operation mode of the image forming apparatus.

Abstract: A switching power supply device including: a transformer configured to include a primary winding, a secondary winding, and an auxiliary winding; a switching unit configured to switch a current that flows through the primary winding of the transformer; a control unit configured to control a switching operation of the switching unit; a starting resistor connected between a voltage input side of the primary winding and a power supply terminal of the control unit; a voltage supply unit configured to rectify and smooth a voltage output from the auxiliary winding and supply the resultant to the power supply terminal; and an activation control unit configured to control activation timing of the control unit by inputting a voltage to an ON/OFF terminal of the control unit, the activation control unit being connected between the voltage input side of the primary winding and a ground side of the auxiliary winding.

Abstract: A power control apparatus and an image forming apparatus is provided to prevent a heating element from overheating when DC power is supplied and to perform normal operation regardless of the type of input power. The power control apparatus includes a power supply to supply power to a load, an alternating current (AC) power switch to discontinuously switch on AC power between the power supply and the load, and a direct current (DC) cutoff circuit to block supply of DC power through the AC power switch to prevent supply of the DC power to the load via the AC power switch when the DC power is input through the power supply.

Abstract: A high-voltage power supply for an image forming apparatus compares a detected output voltage generated by dividing a high-voltage output by a voltage dividing circuit with a control value to feedback control the high-voltage output and outputs a voltage that is to be applied to a member involved in image formation. The high-voltage power supply includes a printed circuit board on which a resistor connected to a high-voltage output side of the voltage dividing circuit is mounted. A slit including a first portion and a second portion is formed in the printed circuit board. The first portion extends across a straight line connecting terminals of the resistor. The second portion continues from the first portion and extends in a direction receding from one of the terminals of the resistor.

Abstract: The power supply apparatus is configured to detect the output voltage of a piezoelectric transformer and controls the frequency of a pulse signal to drive the piezoelectric transformer based on the detected output voltage and a preset target voltage so as to perform feedback control of the output voltage of the piezoelectric transformer, the gain when performing the feedback control is switched in accordance with the target voltage.

Abstract: A power supply apparatus including a current regulation unit configured to regulate a surge current generated on a primary side of a piezoelectric transformer. The surge current is generated when the piezoelectric transformer including a piezoelectric element and a holding unit, which are connected to each other using a conductive rubber, is driven.

Abstract: A high-voltage power supply to output a plus/minus high-voltage, which is applied to image forming apparatuses, includes a plus high-voltage output unit outputting the plus high-voltage by using a Pulse Width Modulation (PWM) signal, a minus high-voltage operation control unit charging a certain voltage while the plus high-voltage output unit is outputting the plus high-voltage, a minus high-voltage output unit outputting the minus high-voltage by using the certain voltage charged in the minus high-voltage operation control unit, and a minus high-voltage blocking unit to block the output of the minus high-voltage from the minus high-voltage output unit while the plus high-voltage output unit is outputting the plus high-voltage.

Abstract: A voltage conversion unit converts alternating current voltage generated by an alternating current voltage generation unit into a predetermined output voltage. An adjustment unit monitors the output voltage and adjusts a driving pattern for driving the alternating current voltage generation unit in accordance with a waveform distortion generated in a rectangular wave of the output voltage. The driving pattern is a pattern having, in a half cycle of the rectangular wave of the alternating current voltage, a first ON period during which the alternating current voltage is applied to the voltage conversion unit, an OFF period during which the alternating current voltage is not applied to the voltage conversion unit, and a second ON period during which the alternating current voltage is applied to the voltage conversion unit. The adjustment unit adjusts a ratio of the first ON period, the OFF period, and the second ON.

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.