Abstract: An image forming apparatus includes a developing cartridge, a main memory and a controller. The controller is configured to perform determining whether the developing cartridge is reached a lifetime on a basis of: at least one of s developing maximum printable number of sheets which corresponds to developing identification information, a maximum developing roller rotation number which corresponds to the developing identification information, and a maximum dot count which corresponds to the developing identification information; and at least one of a developing cumulative number of printed sheets, a cumulative developing roller rotation number and a cumulative dot count.

Abstract: An image forming unit forms an image on a sheet. A first generation circuit generates, regarding a member involved in image formation in the image forming unit, a first signal relating to a first abnormality. A second generation circuit generates, regarding the member, a second signal that relates to a second abnormality different from the first abnormality, and whose feature in a time axis direction or a frequency axis direction is different from that of the first signal. A control circuit has a single port to which the first signal and the second signal are to be input. The control circuit identifies between the first signal and the second signal based on a feature of a signal input to the port.

Abstract: According to one embodiment, an image forming apparatus includes an image forming portion, and a control portion. The image forming portion includes an image carrier, a charging device, and a cleaning device. The charging device includes a charging roller which contacts a surface of the image carrier. The cleaning device includes a cleaning blade, and an adjustment portion. The cleaning blade slidably contacts the surface of the image carrier. The adjustment portion adjusts a linear pressure of the cleaning blade exerted on the surface of the image carrier. The control portion executes, when a rate of increase of an outer layer resistance value of the charging roller caused by a decrease in the function of the cleaning blade is greater than or equal to a first rate, linear pressure adjustment control of controlling the adjustment portion to increase the linear pressure of the cleaning blade.

Abstract: Provided an electro-conductive member that can be used as a charging member capable of preventing the emergence of a ghost image. The member comprises an electro-conductive support and an electro-conductive layer, the electro-conductive layer has a matrix including a first cross-linked rubber, and domains, the domains each includes a second cross-linked rubber and an electronically conductive agent, at least some of the domains are exposed to an outer surface of the member to constitute protrusions, the outer surface is constituted by the matrix and the exposed domains, and in a double logarithmic plot with a frequency on the abscissa and an impedance on the ordinate, a slope at a frequency of 1.0×105 Hz to 1.0×106 Hz is ?0.8 to ?0.3, and an impedance at a frequency of 1.0×10?2 Hz to 1.0×101 Hz is 1.0×103 to 1.0×107?.

Abstract: An image forming apparatus includes an endless belt, a rotary member configured to transfer the toner image on the belt to the recording material, a power supply configured to apply transfer voltage to the rotary member to transfer the toner image on the belt to the recording material, an acquisition unit configured to acquire each value related to the number of recording materials passing through each area of the belt divided into a plurality of areas in a width direction of the belt, and an output unit configured to output error information related to a life of the belt based on each value.

Abstract: An image forming apparatus has a photosensitive member, a plurality of corona chargers configured to charge the photosensitive member by corona discharge, a plurality of charge output circuits configured to output a charging voltage being applied to each of the corona chargers, a plurality of abnormal discharge detection circuits configured to output an abnormal discharge detection signal according to abnormal discharge occurring in each of the corona chargers, and a controller configured to have a common input port connected to the abnormal discharge detection circuits wherein the abnormal discharge detection signal output from each of the abnormal discharge detection circuits is input to the controller through the common input port. Each of the abnormal discharge detection circuits is connected to a corresponding one circuit out of the charge output circuits.

Abstract: An image forming apparatus includes: an image carrier; a charging roller that charges the image carrier; a power supply part that applies a charging voltage to the charging roller; a current measurement part that measures a value of a DC component of a current flowing between the image carrier and the charging roller at at least two timings having mutually different elapsed times; and a hardware processor that measures an elapsed time from a start of application of the charging voltage by the power supply part, calculates a coefficient of an approximate expression indicating a relationship between the value of the DC component of the current flowing between the image carrier and the charging roller, and the elapsed time, and performs judgment related to life of the charging roller on the basis of the coefficient and a predetermined threshold.

Abstract: An imaging device includes a substrate supply, a printing system with at least one marking device adapted to transfer an image to a substrate resulting in a marked substrate, a scanning device and a substrate output. The substrate supply, printing system, scanning device, and substrate output are provided along the same shared substrate path providing an imaging system with reduced complexity.

Abstract: An image forming apparatus includes: an image carrier that carries and transports a latent image; a charging member that is arranged to be in contact with a surface of the image carrier; a developing device that supplies toner to the image carrier and forms a toner image; a density detection unit that detects a density of the toner image; a pattern detection unit that detects a predetermined density variation pattern based on a detection result of the density detection unit according to the toner image; and a determination unit that determines a state of the charging member based on the number of the predetermined density variation patterns detected within a predetermined period of time.

Abstract: An image forming apparatus includes a member arranged in contact with or in proximity to an image carrier, a sensor for measuring an electrical characteristic value of the member, a power supply which switches from a first mode in which one of a constant current and a constant voltage is applied to the member to a second mode in which the other is applied to the member, a storage which stores first correspondence between an amount of use of the member in the first mode and the electrical characteristic value, and a hardware processor. The hardware processor obtains second correspondence between the electrical characteristic value measured with the sensor and the amount of use of the member in the first mode and predicts a serviceable period of the member when the power supply is switched to the second mode based on the first and the second correspondences.

Abstract: An image forming apparatus generates a calibration chart including a plurality of patches at different densities. The image forming apparatus includes at least one sensor, a memory, and a circuitry. The memory stores patch data values of the patches. The circuitry acquires sheet data about a sheet to which the calibration chart is output. The circuitry generates the calibration chart in which the patches are arranged in a color measurable region of the at least one sensor, based on at least the sheet data and data indicating the color measurable region.

Abstract: In a sensor, a light emitter outputs light with which a toner pattern on an image carrier or a surface material of the image carrier is irradiated, and a photodetector receives reflection light from the toner pattern or the surface material. The sensor light intensity control unit provides a control voltage to the light emitter and controls light intensity thereof. The density determining unit determines a toner density on the basis of output of the photodetector. Further, the density determining unit determines a reference control voltage of the light emitter to set as a predetermined value the output of the photodetector corresponding to the reflection light from the surface material, determines a correction parameter corresponding to the reference control voltage, determines a correction amount corresponding to the correction parameter and the toner density, and corrects the toner density on the basis of the correction amount.

Abstract: In an embodiment, a processor-readable medium stores code representing instructions that when executed by a processor cause the processor to access a list of print jobs for printing. The processor further determines a healthy area of a transfer media. For each job in the list, the processor calculates an image risk area (IRA) based on the healthy area, and ranks each job in a print order according to its IRA.

Abstract: An image forming apparatus including an image carrier, a transfer member, an application circuit and a controller configured to acquire a transfer resistance value, the transfer resistance value being a value of electric resistance between the image carrier and the transfer member, determine whether the acquired transfer resistance value is less than or equal to a reference resistance value, and control the application circuit, in response to determining that the acquired transfer resistance value is less than or equal to the reference resistance value, to perform a current control process to cause a value of a transfer current passing through the transfer member becomes a target current value.

Abstract: An image forming apparatus includes: an image forming section configured to form a predetermined test image on an image bearing member by a regular development scheme and a first bias development scheme; a concentration detection section configured to detect a concentration of the test image formed by the image forming section; and a causal part determination section configured to determine on a basis of a result of detection by the concentration detection section a causal part of an image defect that is caused when an image is output.

Abstract: An image forming apparatus includes an image forming unit configured to form a measurement image on a sheet, a measurement unit configured to radiate light on the measurement image via a transparent window, and measure the light reflected from the measurement image, a white reference plate of which a white level is measured by the measurement unit, a black member of which a black level is measured by the measurement unit, and a determination unit configured to determine, based on a change in a measurement result of the white reference plate and a change in a measurement result of the black member measured by the measurement unit, whether the white reference plate, the black member, or the window is soiled.

Abstract: Provided is a charging member contamination determining device including plural units that includes a charging member, a member to be charged and a measuring section that measures a discharging current value between the charging member and the member to be charged, a calculating section that calculates a difference between current values measured by two units among the plural units, and a determining section that determines the presence or absence of contamination in the charging member based on the difference between the current values for each combination of two units calculated by the calculating section.

Abstract: An image forming apparatus comprises a plurality of photoconductors, a plurality of chargers including charging members, a voltage application unit to which charging members are connected in parallel and which is configured to apply a voltage to the charging members, a controller, and a messaging unit. The controller is configured to change, upon startup, the voltage to be applied by the voltage application unit to the charging members from a previously applied first voltage to a second voltage of which an absolute value is smaller than that of the first voltage, to obtain amounts of electric currents caused to flow through the respective charging members by application of the second voltage. A determination as to whether any anomaly is present is made based upon the obtained amounts of electric currents for the charging members. The messaging unit is configured to produce a notification about presence or absence of anomaly.

Abstract: A management server capable of communicating with a providing apparatus via a network and using a function provided by the providing apparatus includes a reception unit configured to receive failure information from the image forming apparatus, and a notification unit configured to perform notification for arranging maintenance of the image forming apparatus according to the failure information received from the image forming apparatus, wherein the management server does not arrange the maintenance of the image forming apparatus if it can be identified that the failure is caused by the providing apparatus based on the received failure information.

Abstract: An image forming apparatus for forming an image in accordance with light to be emitted from a light source includes: a digital half-toning unit configured to convert a uniform-pixel-value region of image data to a parallel-line pattern formed with a plurality of parallel lines extending obliquely with respect to a direction, in which pixels are arrayed, thereby expressing each gray level of the image data as an area percentage; a modulated-signal generating unit configured to generate a modulated signal by modulating the converted image data with a clock signal; a light-source driving unit configured to drive the light source according to the modulated signal; and an edge control unit configured to narrow a to-be-illuminated region, which is to be illuminated by the light from the light source, in each of edge neighborhoods of the lines constituting the parallel-line pattern, while increasing intensity of the light.

Abstract: An image forming apparatus includes a photosensitive section driven to rotate, a light emission unit configured to emit light to form electrostatic latent images on the photosensitive section, a process section configured to form images on the photosensitive section, a detection unit configured to detect an output generated via the process section when an electrostatic latent image for correction passes through a position facing the process section, and a control unit configured to execute a correction of a position of an electrostatic latent image in image formation based on a detection result from the detection unit.

Abstract: A reference value of an electric current flowing through each charging member is determined and recorded in a memory unit at a predetermined time by a reference value recording unit. A voltage application unit is caused to start applying a voltage to the charging members upon startup of an image forming apparatus, and a measurement value of an electric current flowing through each charging member is determined by a measurement unit. A charging member of which the measurement value is such that an absolute value of a difference between the reference value and the measurement value is not smaller than a predetermined value is marked by a determination unit. If there is at least one marked charging member and at least one not-marked charging member, a notification produced by a messaging unit is given through a notification unit.

Abstract: An image forming apparatus includes a photosensitive member; a corona charger, provided with an opening, for electrically charging the photosensitive member; a sheet-like shielding member for shielding the opening of the corona charger; a moving device for moving the shielding member in a longitudinal direction of the photosensitive member; a potential sensor for detecting a potential of a portion of the photosensitive member chargeable by the corona charger; and a controller for detecting, on the basis of a result of detection of the potential of the portion of the photosensitive member by the potential sensor, whether or not a charging operation capable of electrically charging the photosensitive member by the corona charger is performed in a state in which the shielding member is located between the opening of the corona charger and the photosensitive member.

Abstract: The image forming apparatus includes a CPU that performs control to form an inspection image for determining whether or not banding is suppressed to be smaller than a predetermined threshold value; and a density sensor that detects an intensity of banding periodically occurring in a sub-scanning direction of the formed inspection image. If based the detected banding intensity, the CPU has determined that the banding is not suppressed to be smaller than the predetermined threshold value, the CPU performs control to not perform banding correction or performs control to re-set a relationship between a phase of a rotary member and correction information.

Abstract: An apparatus to monitor a condition of a solid state charge device (SSCD) useful in electrostatic printing includes a power supply and a frequency detector. The power supply provides current to the SSCD, and includes a resonant controller. The frequency detector senses a frequency associated with the current, and since the frequency is representative of the condition of the SSCD, the frequency detector thereby monitors the condition of the SSCD. A method of monitoring the condition of the SSCD includes providing current to the SSCD using a power supply, and sensing a frequency associated with the current. The power supply includes a resonant controller, and the frequency is representative of the condition of the SSCD, and thus the method thereby monitors the condition of the SSCD. A corresponding computer-readable medium is also disclosed.

Abstract: An image forming apparatus includes a rotatable belt member, a plurality of image forming members opposing the belt in an image forming region, a first detecting member configured to detect a position of the belt member with respect to a widthwise direction, a second detecting member configured to detect a moving direction, an adjusting roller configured to adjust the moving direction in the image forming region, the adjusting roller configured to adjust the moving direction in the image forming region, and a control portion configured to control a position of the adjusting roller on the basis of outputs of the first detecting member and the second detecting member without changing a position of the belt member in the image forming region in a direction perpendicular to a surface of the belt member.

Abstract: A computer implemented method of cleaning electrodes (such as wires) is used in a toner-based electrostatic printing device. The electrodes produce an environment containing charged toner particles to assist in electrostatic printing. The method automatically monitors at least two printing parameters that are unrelated to signals and voltages provided to the electrodes (using a processor of the electrostatic printing device). Further, this method also uses the processor automatically infers a toner contamination of the electrodes from the printing parameters. This allows the processor to automatically adjust the printing the used by the electrostatic printing device during electrostatic printing to maintain the contamination of the electrodes below a threshold.

Abstract: An apparatus to monitor a condition of a solid state charge device (SSCD)) useful in electrostatic printing includes a power supply and a frequency detector. The power supply provides current to the SSCD, and includes a resonant controller. The frequency detector senses a frequency associated with the current, and since the frequency is representative of the condition of the SSCD, the frequency detector thereby monitors the condition of the SSCD. A method of monitoring the condition of the SSCD includes providing current to the SSCD using a power supply, and sensing a frequency associated with the current. The power supply includes a resonant controller, and the frequency is representative of the condition of the SSCD, and thus the method thereby monitors the condition of the SSCD. A corresponding computer-readable medium is also disclosed.

Abstract: An image forming apparatus includes: a photoconductor; a charger configured to charge the photoconductor, the charger having a discharge wire and a grid; a charge-voltage applying device configured to generate charge voltage and apply the charge voltage to the discharge wire; and an abnormal-discharge detector provided between an output end portion of the charge-voltage applying device and the ground. The abnormal-discharge detector is configured to detect an abnormal discharge occurring in the charger by detecting an abnormal current passing via the grid and the ground upon occurrence of the abnormal discharge.

Abstract: A method includes moving a first end portion of a charging member with respect to a photoconductive member to obtain a first electrical discharge event corresponding to conduction of an electrical current from the charging member to the photoconductive member. The method also includes identifying a first adjustment value corresponding to a distance in which the first end portion moved toward the photoconductive member to obtain the first electrical discharge event. The method also includes moving a second end portion of the charging member with respect to the photoconductive member to obtain a second electrical discharge event corresponding to conduction of an electrical current from the charging member to the photoconductive member. The method also includes identifying a second adjustment value corresponding to a distance in which the second end portion moved toward the photoconductive member to obtain the second electrical discharge event.

Abstract: An image forming apparatus includes an image carrier, a charging member, a voltage applying part, a current measuring part and a controlling part. The image carrier carries a toner image. The charging member electrically charges the image carrier. The voltage applying part applies voltage to the charging member. The current measuring part measures current flowing into the charging member. The controlling part controls applied voltage of the voltage applying part. The controlling part decides, when a predetermined voltage is applied to the charging member for a predetermined time by the voltage applying part, if an increase quantity of the current measured by the current measuring part exceeds a predetermined threshold value, that at least one of the image carrier and the charging member is in an abnormal state.

Abstract: A belt drive apparatus is equipped with an endless belt rotationally movable by being supported by a plurality of rollers. A moving speed signal output part outputs a signal based on a rotational movement of the endless belt. A width direction position signal output part outputs a position signal for which its value changes in response to a position of the endless belt in a direction of width of the endless belt. A width direction position control part controls a position of the endless belt in the direction of width of the endless belt. A process execution part performs a predetermined process using the signal output from the moving speed output part based on the position signal output from the width direction position signal output part.

Abstract: An image forming apparatus includes: a photoconductor; a charger configured to charge the photoconductor, the charger including a discharge wire and a grid; a voltage applying circuit configured to generate charge voltage and apply the charge voltage to the discharge wire of the charger; a grid-current detector configured to detect a grid current passing through the grid; a controller configured to control the voltage applying circuit on the basis of a detection value detected by the grid-current detector so that the grid current is constant; an abnormal-discharge detector configured to detect an abnormal discharge occurring in the charger; and a suppression resistor configured to suppress abnormal discharge energy. The suppression resistor includes a first terminal and a second terminal. The first terminal is connected to the grid. The second terminal is connected to at least one of the grid-current detector and the abnormal-discharge detector.

Abstract: Provided is an image forming apparatus capable of accurately detecting deformation of a roller member. The image forming apparatus configured to form an image by forming an electrostatic latent image on a photosensitive drum (1) and developing the electrostatic latent image by a developer, includes: a rotatable roller member (2) configured to be held in press-contact with the photosensitive drum (1); and a deformation determining unit configured to determine deformation of the roller member (2), and the deformation determining unit configured to detect a value of a current flowing between the roller member (2) and the photosensitive drum (1) in response to application of a voltage to the rotating roller member (2), and determine the deformation of the roller member (2) based on the detection result.

Abstract: According to aspects of the embodiments, there is provided an apparatus and method to detect when a consumable such as a toner bottle is replaced before end of life (EOL), throwing out toner that could be used for future printing incurs a cost. In metered accounts, the supplier incurs the cost of this waste. This disclosed process proposes monitoring the approximate rate of toner and then calculating the average amount of consumption per bottle since the last time the bottle was detected as empty. This then determines the toner consumption per bottle yield rate. Yield rate (YR) is calculated based on the estimated amount of toner delivered from a known bottle quantity at the point when the current bottle goes empty. The yield rate is displayed as a gauge on the user interface of the printer.

Abstract: A method includes moving a first end portion of a charging member with respect to a photoconductive member to obtain a first electrical discharge event corresponding to conduction of an electrical current from the charging member to the photoconductive member. The method also includes identifying a first adjustment value corresponding to a distance in which the first end portion moved toward the photoconductive member to obtain the first electrical discharge event. The method also includes moving a second end portion of the charging member with respect to the photoconductive member to obtain a second electrical discharge event corresponding to conduction of an electrical current from the charging member to the photoconductive member. The method also includes identifying a second adjustment value corresponding to a distance in which the second end portion moved toward the photoconductive member to obtain the second electrical discharge event.

Abstract: An image forming apparatus is provided. The image forming apparatus includes a lateral cover, which is an external covering to cover a lateral side of the image forming apparatus, and a connector member having at least one protrusion, by which the lateral cover is connected to the connector member. The lateral cover is formed to have an inwardly-dented handgrip, which has an open end and a closed end, and at least one opening on an upper section of the handgrip. The at least one protrusion protrudes downwardly from a surface of the connector member. The at least one protrusion is inserted in the at least one opening of the lateral cover to penetrate the connector member and to protrude downwardly from the upper section of the handgrip.

Abstract: This disclosure provides methods and systems for troubleshooting charging and photoreceptor failure modes associated with a xerographic process. Specifically, according to an exemplary method the photoreceptor decay behavior, with and without the effects of depletion, are quantified and used to determine a performance state of one or more of the charging stations and the photoreceptor surface.

Abstract: An image forming apparatus including: a plurality of photosensitive drums; a plurality of scorotron chargers provided for the plurality of photosensitive drums, respectively, a voltage application circuit commonly connected to the plurality of scorotron chargers, a plurality of wires provided for the plurality of scorotron chargers, respectively; a plurality of grid electrodes provided for the plurality of scorotron chargers, respectively; at least one of current detecting units provided for at least one of the plurality of grid electrodes, respectively, and at least one of the current detecting units detecting grid current which flows into at least one of the grid electrodes, respectively; and a control device configured to control the voltage application circuit such that at least one of the grid currents detected by at least one of the current detecting units become equal to or higher than a reference value.

Abstract: An image forming apparatus and a method of monitoring power consumption of the image forming apparatus are provided. For each one of parts of the image forming apparatus selected for monitoring, part-specific power consumption information is obtained based on accumulated operation amount information. The obtained part-specific power consumption information is used to generate power consumption information indicating an amount of electric power consumed by at least a portion of the image forming apparatus.

Abstract: An image forming apparatus which comprises a developing unit having a toner and a carrier therein, the apparatus includes an agitator to agitate the toner, a toner sensor to receive a control voltage and to generate an output voltage corresponding to a remaining amount of the toner in the developing unit, a pulse width modulator to supply the control voltage to the toner sensor corresponding to a pulse width modulation (PWM) signal and a controller to control the pulse width modulator to supply the control voltage to the toner sensor to adjust a duty ratio of the PWM signal and make the output voltage reach a target value. The controller determines whether the agitator is normal or abnormal based on the output voltage of the toner sensor.

Abstract: An image recording apparatus, including: a recording device; discharge trays; a discharge mechanism; detectors; an input device through which is inputted authentication information relating to image data; and a controller including: an image-data reception portion; an authentication-information confirming portion to make a confirmation as to whether the authentication information contains specific information; a confirmation-necessity judging portion to judge whether the confirmation by the confirming portion with respect to the image data is necessary; a selecting portion to select one discharge tray on which the recording medium is not placed, wherein, where the judging portion judges that the confirmation is necessary, the controller permits selection of the one discharge tray, controls the recording device to record the image based on the image data after the confirmation that the authentication information contains the specific information, and controls the discharge mechanism to discharge, to the select

Abstract: As set forth herein, computer-implemented methods and systems facilitate adjusting an HFSI counter increment as a function of local relative humidity in order to adjust corona device lifespan. Adjustment factors are set for a plurality of GOM levels and an adjustment factor to be applied to the HFSI counter increment is assigned to or set for each GOM level. A curve is determined or calculated that approximates the adjustment factor, and a quadratic equation defining the curve is determined. Humidity measurement data is received from an environmental sensor coupled to the printer device, and depending on the relative humidity in the local environment of the printer, and an adjustment factor derived from the quadratic equation is applied to the HFSI counter increment to adjust for dry or humid conditions.

Abstract: In an image-forming device, each of the N chargers charges the opposed photoconductor with a discharge. The voltage applying unit applies voltages to the N chargers, individually. The abnormal discharge detecting unit detects an occurrence of an abnormal discharge at least one of the N chargers. The voltage detecting unit detects first voltages applied to the N chargers before the occurrence of the abnormal discharge is detected, and second voltages applied to the N chargers after the occurrence of the abnormal discharge is detected. The calculating unit calculates a difference between the first voltage and the second voltage for each of the N chargers. The identifying unit identifies one charger as a charger at which the abnormal discharge is occurring. The difference between the first voltage and the second voltage applied to the one charger is the greatest among the differences.

Abstract: An image forming apparatus which comprises a developing unit having a toner and a developer therein, the apparatus includes a toner sensor to receive a control voltage and to generate an output voltage corresponding to a remaining amount of the toner in the developing unit, a pulse width modulator to supply the control voltage to the toner sensor corresponding to a pulse width modulation (PWM) signal and a controller to control the pulse width modulator to supply the control voltage to the toner sensor to adjust a duty ratio of the PWM signal and make the output voltage reach a target value.

Abstract: An image forming apparatus includes: sensor detecting light intensity and output voltage based on the light intensity; data acquisition part setting reference voltages for the sensor to detect light intensity of bare surface of intermediate transfer member, acquiring, at set reference voltage, voltage output by the sensor on the bare surface as detection data; storage storing the detection data corresponding to the reference voltages; judgment part judging whether to perform image density correction processing; voltage calibration part adjusting output level at light intensity detection; density acquisition part forming toner pattern, and acquiring density data of the toner pattern by causing the sensor having adjusted output level to detect its light intensity; density data correction part reading one piece of detection data referring to output level, and correcting the density data based on the detection data; and image density correction part performing the processing based on the density data.

Abstract: An image forming apparatus, comprising: a charge voltage application circuit configured to be connected to a plurality of chargers in a process cartridge and to apply a voltage to the plurality of chargers; a current detection unit configured to detect a current flowing through each of the plurality of chargers; and a controller. The controller judges that the process cartridge is not attached to the image forming apparatus when the current smaller than a first threshold is detected by the current detection unit in a state where the charge voltage application circuit generates a predetermined voltage.

Abstract: An image forming apparatus comprises a plurality of photoconductors, a plurality of chargers including charging members, a voltage application unit to which charging members are connected in parallel and which is configured to apply a voltage to the charging members, a controller, and a messaging unit. The controller is configured to change, upon startup, the voltage to be applied by the voltage application unit to the charging members from a previously applied first voltage to a second voltage of which an absolute value is smaller than that of the first voltage, to obtain amounts of electric currents caused to flow through the respective charging members by application of the second voltage. A determination as to whether any anomaly is present is made based upon the obtained amounts of electric currents for the charging members. The messaging unit is configured to produce a notification about presence or absence of anomaly.

Abstract: An image forming apparatus includes: a photoconductor; a charging unit that charges the photoconductor; an applying unit that produces a charging voltage; a current detecting unit that detects a charging current; an image forming unit that forms an image on a recording medium; a conveying unit that conveys the recording medium; and a control unit. The control unit receives a current detecting signal; determines whether an abnormal discharge occurs during an image forming operation based on the current detecting signal; controls the applying unit to reduce a value of the charging voltage if the abnormal discharge occurs; determines whether the abnormal discharge stops occurring as a result of reducing the value of the charging voltage; and controls the conveying unit to eject the recording medium during the image forming operation if the abnormal discharge stops occurring.

Abstract: An image forming apparatus which comprises a developing unit having a toner and a developer therein, the apparatus includes a toner sensor to receive a control voltage and to generate an output voltage corresponding to a remaining amount of the toner in the developing unit, a pulse width modulator to supply the control voltage to the toner sensor corresponding to a pulse width modulation (PWM) signal and a controller to control the pulse width modulator to supply the control voltage to the toner sensor to adjust a duty ratio of the PWM signal and make the output voltage reach a target value.