Abstract: A power supply unit is provided. An output generation circuit generates an output corresponding to an supplied drive signal and supplies the output to a load. A detection circuit receives the output and generates a detection signal in response to the output. A control circuit generates a digital control signal for controlling a value of the output toward a target value in response to the detection signal. A first D/A conversion circuit receives the digital control signal and converts the digital control signal into an analog control signal, the first D/A conversion circuit being capable of setting a reference range for defining a voltage range of the analog control signal. A driving circuit generates the drive signal in response to the analog control signal and supplies the drive signal to the output generation circuit. A range switching circuit switches the reference voltage range of the first D/A conversion circuit between a wide range and a narrow range narrower than the wide range.

Abstract: A feedback control device is provided. The feedback control device includes a controlled-system which outputs an output in correspondence with a control signal; a feedback signal generating member which generates a feedback signal as the output of the controlled-system; a reference signal unit which outputs a reference control signal to the controlled-system; and a determination unit which determines a version of the controlled-system on the basis of the feedback signal generated by the feedback signal generating member when the reference signal unit outputs the reference control signal to the controlled-system.

Abstract: An image forming apparatus includes: a plurality of photosensitive members; a plurality of discharging units respectively facing the plurality of photosensitive members; a plurality of high-voltage power supply units which are provided for the plurality of charging units and supply power to the plurality of discharging units; a discharge detection unit that detects abnormality in the plurality of discharging units; a controller which controls the output of one of the high-voltage power supply units having the largest output to be smaller when the discharge detection unit detects abnormality; and a determination unit which, in a state where the controller controls the output of the one of the high-voltage power supply unit, determines whether abnormality occurs in the discharging unit corresponding to the one of the high-voltage power supply unit based on the detection state of the discharge detection unit.

Abstract: An image forming apparatus comprises an image carrier configured to hold a developing agent image; a transfer unit that transfers the developing agent image to a recording medium; a first application unit that controls a transfer voltage applied to the transfer unit; a recovery unit that recovers the developing agent remaining on the image carrier; a second application unit that controls a recovery voltage applied to the recovery unit; a determination unit that determines whether or not a recovery current flowing between the image carrier and the recovery unit exceeds a first predetermined current value; and a control unit that, when the determination unit makes a positive determination that the recovery current has exceeded the first predetermined current value, performs a protective control for controlling the first application unit such that a transfer current flowing between the image carrier and the transfer unit becomes greater.

Abstract: An image forming apparatus includes an object to be cleaned, a cleaning device, a generation device, a control device, a voltage detection device and a load resistance detection device. The cleaning device cleans the object to be cleaned. The generation device generates a cleaning voltage in the cleaning device. The control device controls the generation device thereby to control the cleaning voltage. The voltage detection device detects the cleaning voltage generated in the cleaning device. The load resistance detection device detects a load resistance between the object to be cleaned and the cleaning device, based on at least one control parameter to be used by the control device to control the generation device and the cleaning voltage detected by the voltage detection device.

Abstract: There is provided an image forming device, including: a first electrical load; a second electrical load; a voltage generation circuit that generates a second voltage to be applied to the second electrical load; a shunt circuit that located between an output side of the voltage generation circuit and the first electrical load; and a controller that executes first control of controlling the shunt circuit to change a first voltage applied from the shunt circuit to the first electrical load to a first target level, and second control of controlling the voltage generation circuit to change the second voltage to a second target level. The controller executes voltage change suppression control of controlling the second voltage such that change of the second voltage becomes gentler as a difference between the first voltage and the first target level becomes larger.

Abstract: An image forming apparatus includes: an attachment unit configured to receive at least one voltage and being replaceable with a test tool, a controller for controlling operation of a plurality of voltage generating circuits, a current detecting section and a deciding section. The controller is configured to control a first voltage generating circuit so as to generate a test voltage and so as to apply the test voltage through a first voltage line, the test tool, and a second voltage line to a second voltage generating circuit. The deciding section is configured to, upon a detection current corresponding to the applied test voltage and detected by the current detecting section being equal to or greater than a first predetermined value, decide that the predetermined voltages are to be normally applied through the respective first and second voltage lines to the attachment unit.

Abstract: An image forming apparatus includes a voltage applying unit for applying a voltage to an electric load; a sub control unit for controlling the voltage applying unit; a restarting unit for restarting the sub control unit in response to receipt of a restart signal; a determining unit for determining whether or not restart of the sub control unit is abnormal restart; and a main control unit. The main control unit generates a control start signal for allowing the voltage applying unit to start generation of the voltage, and the restart signal. When the determining unit determines that restart of the sub control unit is abnormal restart, the main control unit sends again the control start signal to the sub control unit.

Abstract: An image forming apparatus is provided. The image forming apparatus includes a photosensitive member which carries an electrostatic latent image; a charger comprising a charging wire extended in a direction parallel to an axial direction of the photosensitive member, the charger serving to charge the photosensitive member, and a promoting unit which is provided on at least one side of a region of the charger which is opposite to an image forming region in which the electrostatic latent image is formed, the promoting unit promoting a leakage current of the charger; detecting unit which detects a leakage current of the charger; and a correction unit which corrects the charging wire if the leakage current is detected.

Abstract: A power supply circuit identification device for identifying a type of a power supply circuit, the power supply circuit having an input terminal to which a control signal for controlling electrical power supplied to an electrical load is input and an output terminal from which a detection signal that indicates whether the electrical power corresponding to the control signal is supplied to the electrical load is output, at least one of the input terminal and output terminal being plurally provided and having a type-dependent correlation between the input and output terminals. The identification device includes: a control section configured to input the control signal to the power supply circuit via the input terminal; a reading section configured to read the detection signal from the output terminal; and an identification section configured to identify a type of the power supply circuit based on a reading result from the reading section.

Abstract: An image-forming device includes a cleaning unit, a toner detection unit, a control unit, and a cleaning target member in the housing. The cleaning unit applies a predetermined voltage with a predetermined absolute value to the cleaning target member to remove toner from the cleaning target member through an electrostatic force. The toner detection unit detects an amount of toner on the cleaning target member at least twice to detect a first amount of toner and a second amount of toner. The first amount and the second amount of toner are detected when a first voltage having a first absolute value is applied as the predetermined voltage at a first time and when a second voltage having a second absolute value is applied as the predetermined voltage at a second time. The control unit determines the predetermined absolute value based on the first toner amount and the second toner amount.

Abstract: An image forming device includes plural electrostatic latent image holding bodies that hold, on surfaces thereof, electrostatic latent images to be developed with developers of multiple colors, respectively, plural electrification control units that face the electrostatic latent image holding bodies and charge or discharge the surfaces of the electrostatic latent image holding bodies, respectively, a current controller that controls electric currents, each of which is supplied between the electrostatic latent image holding body and the electrification control unit for a corresponding one of the multiple colors, to be a constant target current, a maximum voltage output unit that outputs a maximum voltage among voltages each of which is applied between the electrostatic latent image holding body and the electrification control unit for a corresponding one of the multiple colors, and a detector that detects malfunction of the electrification control units when the maximum voltage exceeds a predetermined value.

Abstract: A power supply for supplying electric power comprises a power circuit which supplies L channels of electric power (L: positive integer), a control circuit board which outputs multiple types of control signals including a digital control signal and a PWM signal, a digital-to-analog converter having M channels (M: positive integer less than L) each of which converts the digital control signal into an analog control signal, and N demodulation circuits (N=L?M) each of which generates an analog control signal by demodulating the PWM signal. The control circuit board is electrically connected to the power circuit via the M channels of the digital-to-analog converter and the N demodulation circuits. N is a positive integer not more than M.

Abstract: There is provided an image forming device, comprising: a first electrical load; a second electrical load; a voltage generation circuit that generates a second voltage to be applied to the second electrical load; a shunt circuit that located between an output side of the voltage generation circuit and the first electrical load; and a controller that executes first control of controlling the shunt circuit to change a first voltage applied from the shunt circuit to the first electrical load to a first target level, and second control of controlling the voltage generation circuit to change the second voltage to a second target level. The controller executes voltage change suppression control of controlling the second voltage such that change of the second voltage becomes gentler as a difference between the first voltage and the first target level becomes larger.

Abstract: A power supply unit is provided. An output generation circuit generates an output corresponding to an supplied drive signal and supplies the output to a load. A detection circuit receives the output and generates a detection signal in response to the output. A control circuit generates a digital control signal for controlling a value of the output toward a target value in response to the detection signal. A first D/A conversion circuit receives the digital control signal and converts the digital control signal into an analog control signal, the first D/A conversion circuit being capable of setting a reference range for defining a voltage range of the analog control signal. A driving circuit generates the drive signal in response to the analog control signal and supplies the drive signal to the output generation circuit. A range switching circuit switches the reference voltage range of the first D/A conversion circuit between a wide range and a narrow range narrower than the wide range.

Abstract: An image forming apparatus is provided. A first cleaning unit is configured to collect a particle deposited on an object. An applying unit is configured to apply a voltage to the first cleaning unit. A first detector is configured to detect a first current flowing between the first cleaning unit and the object A controller is configured to control the applying unit. When the detected first current becomes equal to or greater than a first predetermined value, the controller controls the applying unit to reduce the voltage applied to the first cleaning unit so as to make the first current smaller than the first predetermined value.

Abstract: An image forming apparatus comprises an image carrier configured to hold a developing agent image; a transfer unit that transfers the developing agent image to a recording medium; a first application unit that controls a transfer voltage applied to the transfer unit; a recovery unit that recovers the developing agent remaining on the image carrier; a second application unit that controls a recovery voltage applied to the recovery unit; a determination unit that determines whether or not a recovery current flowing between the image carrier and the recovery unit exceeds a first predetermined current value; and a control unit that, when the determination unit makes a positive determination that the recovery current has exceeded the first predetermined current value, performs a protective control for controlling the first application unit such that a transfer current flowing between the image carrier and the transfer unit becomes greater.

Abstract: An image forming apparatus has: an image forming unit which is configured to scan a laser beam in a main scanning direction to expose a photosensitive member, and which forms an electrostatic latent image on the photosensitive member to form an image; a process cartridge that is detachably mounted within the image forming apparatus, the process cartridge holding the photosensitive member on which the electrostatic latent image is formed, and configured to develop the electrostatic latent image by supplying toner to the electrostatic image; and an origin detection unit that is provided on the process cartridge in a position lying within a range of an optical path of the laser beam and out of a range of an optical path of the laser beam for forming the electrostatic latent image, the origin detection unit configured to detect an origin of the laser beam for scanning and exposing.

Abstract: An image forming apparatus is provided. The image forming apparatus includes: a photosensitive member; a discharging unit arranged to face the photosensitive member; a high-voltage power supply unit which supplies power to the discharging unit; a discharge detection unit which detects abnormal discharge in the discharging unit; an output controller which controls an output of the high-voltage power supply unit according to control information; and a cleaning detection unit which compares current control information for the high-voltage power supply unit supplying power to the discharging unit in which abnormal discharge is detected with previous control information for the high-voltage power supply unit when previous abnormal discharge is detected in the discharging unit, and which detects whether the discharging unit has been cleaned based on the comparison result.

Abstract: A feedback control device is provided. The feedback control device includes a controlled-system which outputs and output in correspondence with a control signal; a feedback signal generating member which generates a feedback signal as the output of the controlled-system; a reference signal unit which outputs a reference control signal to the controlled-system; and a determination unit which determines a version of the controlled-system on the basis of the feedback signal generated by the feedback signal generating member when the reference signal unit outputs the reference control signal to the controlled-system.