Abstract: An image forming apparatus includes: an image carrier; an exposure device; a developing device that develops the latent image on the image carrier by using a toner charged to a predetermined polarity and having an external additive; a transfer device that transfers a toner image developed on the image carrier to a transfer medium; a first charging member that charges the external additive and the transfer residual toner remaining on the image carrier and the image carrier after transfer to the same polarity as a polarity of the toner; a cleaning member that electrostatically attracts the external additive and the transfer residual toner charged by the first charging member; and a second charging member that charges the image carrier to an electric potential smaller in absolute value than an electric potential of the image carrier generated after the image carrier passes the cleaning member.

Abstract: Provided is an apparatus and method for supplying a charge voltage to an organic photoconductor (OPC) drum. The apparatus includes a storage unit for storing first service life information of the OPC drum according to a first supplying method, and second service life information of the OPC drum according to a second supplying method, a sensor unit for measuring information about conditions surrounding the apparatus, a control unit for selecting one of the first and second supplying methods according to the measured information and determining a charge voltage corresponding to the service life information according to the selected method, and a voltage supplying unit using the selected method to supply the determined charge voltage to the OPC drum.

Abstract: An image-forming apparatus includes: a first image-forming portion; a second image-forming portion; an executing portion for executing an operation in a first mode in which an image is formed on a recording material by the first and second image-forming portions or a second mode in which an image is formed by the second image-forming portion; an AC-voltage source; a first DC-voltage source; a second DC-voltage source; and a controller for controlling the first and second voltage sources and the AC-voltage source so that in the first mode, application of the AC voltage by the AC-voltage source and the DC voltages by the first and second DC-voltage source are performed, and so that in the second mode, application of the DC voltage by the second DC-voltage source is performed, and application of the AC voltage by the AC-voltage source and the DC voltage by the first DC-voltage source are stopped.

Abstract: An electrophotographic printer includes a rotatable member and a carriage rotatable around an axis. Two rotatable chargers are mounted on the carriage, each for charging the rotatable member. A carriage drive rotates the carriage to bring the first charger into contact with the rotatable member and the second charger into operative arrangement with a cleaner, or vice versa. A charger drive rotates the charger in operative arrangement with the cleaner at a speed greater than a selected speed or with a torque greater than a selected torque, and the rotatable member rotates the rotatable charger in contact therewith at the selected speed with the selected torque.

Abstract: An image formation device for forming an image on a print medium by an electrophotographic process comprises a photosensitive body on which a developer image to be transferred to the print medium is formed by the electrophotographic process including charging of the photosensitive body, a charging unit which includes a charging wire and a grid and thereby electrically charges the photosensitive body, a charging power unit which applies wire potential to the charging wire, a wire potential measuring unit which measures the wire potential, and a charging control unit which controls the amount of electric charge supplied from the charging unit to the photosensitive body by controlling the wire potential based on the wire potential measured by the wire potential measurement unit. The charging control unit includes a control range restricting unit which restricts a control range of the wire potential within a prescribed electric potential.

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: In an image forming apparatus, a plurality of cartridges each of which includes a photoconductor and a charger configured to charge the photoconductor is detachably installable in a main body housing. Chargers are connected in parallel to a voltage application unit configured to apply a voltage to the chargers. A cartridge installation determination unit is configured to determine whether or not each of the cartridges is installed. Control over the voltage application unit exercised by a controller includes a constant-voltage control and a constant-current control. The controller is configured to execute the constant-voltage control upon startup of an initial operation for preparation of printing and to switch from the constant-voltage control to the constant-current control if the cartridge installation determination unit determines that all the cartridges are installed.

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 performs first control, while rotating an image bearing member at a first speed during non-image-formation, to apply a plurality of alternating-current voltages differing in peak-to-peak voltage to a charging device and to detect the value of each alternating current flowing through the image bearing member. When rotating the image bearing member at a second speed during image formation, the image forming apparatus performs second control, while rotating the image bearing member at the second sped before the start of image formation, to apply an alternating-current voltage determined based on the first control to the charging device. In the second control, the image forming apparatus detects the value of the alternating current flowing through the image bearing member, and determines a peak-to-peak voltage of the alternating-current voltage applied to the charging device at the time of image formation based on the detected alternating current value.

Abstract: An image forming apparatus includes a photosensitive member (drum); a rotatable charging member for electrically charging the drum; a bias applying device for applying a charging bias to the charging member in the form of a DC voltage biased with an AC voltage; a current detector for detecting an AC current passing between the charging member and the drum; a temperature and humidity detector; a setting device for setting a condition of the charging bias on the basis of a plurality of detected AC currents passing between the charging member and the drum when a plurality of AC voltages depending on an output of the temperature and humidity detector are applied to the charging member; and a corrector for correcting the set condition of the charging bias on the basis of an output of the current detector when a predetermined AC voltage is applied to the charging member.

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 includes an exposure device having an adjustment period for adjusting an output while exposing a photosensitive drum to light prior to image formation and a developing device. The developing device is configured to change between a contact state where the photosensitive drum and a developing roller are in contact with each other and a separation state where they are separated from each other. The developing device changes from the separation state to the contact state when a portion on the photosensitive drum exposed to light in the adjustment period of the exposure device is at a developing position.

Abstract: An image forming device, comprising: at least one photosensitive body; scorotron chargers that charge the at least one photosensitive body; a charge voltage applying circuit to which the scorotron chargers are commonly connected, the charge voltage applying circuit being configured to apply a voltage to the scorotron chargers; wires respectively provided for the scorotron chargers; grid electrodes respectively provided for the scorotron chargers; a current detection unit configured to detect a grid current of each of the grid electrodes; and a grid current control unit configured to execute a constant-current control for a maximum grid current which is a maximum of grid currents flowing through the grid electrodes so that the maximum grid current is kept at a first threshold larger than or equal to a reference value by adjusting an output of the charge voltage applying circuit.

Abstract: An image forming apparatus includes: an image forming apparatus main body, a driven member removably disposed in the image forming apparatus main body, a rotary driver that rotates by current flowing, and after the blockage of the current flowing, continuously rotates due to an inertial force, a coupling part that has a driving-side member and a driven-side member, wherein when the driven-side member is mounted to the image forming apparatus main body, the driving-side member and a driven-side member are facing each other, and when the driving-side member and the driven-side member engage each other in the rotating direction, the rotary driver and the driven-side member are coupled to transmit the rotation of the rotary driver to the driven-side member, and a controller that controls so that, when the driven-side member is mounted to the image forming apparatus main body, the current flows to the rotary driver, and after the elapse of a certain period of time the current flow to the rotary driver is blocked.

Abstract: An image forming apparatus includes a rotatable photosensitive member; a corona charger provided with an opening opposed to a surface of the photosensitive member; image forming means for forming a toner image on the photosensitive member; a shutter for opening and closing the opening relative to the photosensitive member; sliding means for sliding in contact with the photosensitive member; measuring means for measuring time elapsed from end of image formation; and control means for controlling the apparatus on the basis of an output of the measuring means such that shutter is closed and the photosensitive member is rotated in contact with the sliding means.

Abstract: Provided is an apparatus and method for supplying a charge voltage to an organic photoconductor (OPC) drum. The apparatus includes a storage unit for storing first service life information of the OPC drum according to a first supplying method, and second service life information of the OPC drum according to a second supplying method, a sensor unit for measuring information about conditions surrounding the apparatus, a control unit for selecting one of the first and second supplying methods according to the measured information and determining a charge voltage corresponding to the service life information according to the selected method, and a voltage supplying unit using the selected method to supply the determined charge voltage to the OPC drum.

Abstract: An image forming cartridge comprises a developing unit configured to hold toner including a developing section configured to use the toner for developing and a supplying section configured to provide the toner to the developing section and a toner cartridge attachable to the developing unit, wherein the toner cartridge contains toner and supplies toner to the developing unit and the toner cartridge includes a stand-by charging unit configured to perform stand-by charge to the toner in the toner cartridge.

Abstract: An image forming apparatus includes a rotatable photosensitive member, a charging member, an applying device, an irradiation device, and a controller. The charging member contacts the photosensitive member to charge the photosensitive member. The applying device applies a direct-current voltage to the charging member. The irradiation device irradiates with light an upstream charging gap located upstream of a contact portion between the photosensitive member and the charging member in a rotation direction of the photosensitive member. The controller controls the irradiation device to irradiate with a first light amount when the photosensitive member rotates at a first speed, and to irradiate with a second light amount that is larger than the first light amount when the photosensitive member rotates at a second speed that is lower than the first speed.

Abstract: An image forming apparatus includes photosensitive drums; drum charging members, an AC voltage source for outputting an AC voltage commonly to at least two of the charging members; an AC voltage control devices for the charging members; variable resisters connected between the AC voltage source and the at least two charging members, respectively; use situation detecting means for detecting use situations of the drums, respectively; and adjusting means for adjusting electric resistances of the variable resisters, respectively. The adjusting means adjusts the electric resistances of the resisters in accordance with the detection results of the use situation detecting means such that the discharge currents applied to the at least two charging members are within predetermined ranges, respectively.

Abstract: An image forming apparatus includes photosensitive members, charging members supplied with charging voltages each comprising a component of a DC voltage and a component of an AC voltage, AC current measuring devices for measuring AC currents flowing into charging members, and control means for controlling peak-to-peak voltages of the AC voltages, wherein the control means calculates peak-to-peak voltages of the AC voltages required to provide a predetermined discharge current, from results of the measurements of the AC current measuring devices, and determines a maximum value of the required peak-to-peak voltages as a target value of a constant-voltage-control of the AC voltage in an image forming operation.

Abstract: An image forming apparatus includes an image carrier, a charging device to be applied with a charging voltage, an exposure device, a developer carrier to be applied with a development voltage, a developer supplying member to be applied with a supply voltage, a developer regulation member to be applied with a regulation voltage, and a voltage controller. The developer carrier has thereon a developer having a charge amount Q/M. The charge amount Q/M satisfies 25 [?C/g]?|Q/M|?40 [?C/g]. The image carrier has a surface potential Vopc, the development voltage is expressed as Vdb, and the developer carrier has a developer layer potential Vtnr thereon. The developer layer potential Vtnr relative to a difference between the surface potential Vopc and the development voltage Vdb is expressed by a ratio ?. The ratio ? satisfies 0.1???0.2.

Abstract: There is provided an image forming apparatus in which a correction value is acquired from a storage device provided in a coloring agent cartridge mounted in the image forming apparatus, it is determined whether the acquired correction value is within a specified numerical range, and when it is determined that the acquired correction value is not within the specified numerical range, a control parameter of a specified process relevant to an image forming operation is corrected based on a specified correction value previously set to correct the control parameter of the specified process performed by the image forming apparatus.

Abstract: The image forming apparatus includes a photosensitive drum capable of bearing an electrostatic image, a development device having a developing sleeve capable of bearing a developer and a developer container capable of storing a magnetic toner, and a CPU controlling operation to discharge a developer having polarity opposite to a normally charged polarity to the photosensitive drum by enlarging a restoration electric field to force the developer having a normally charged polarity from the photosensitive drum to the development sleeve during image forming is not performed compared to that during normal image forming is performed, based on a weighted value (p×K) on an edge portion pixel number p of an edge portion of an output image.

Abstract: An image forming unit has a rotatable electrostatic latent image carrier, a charge member positioned to contact the electrostatic latent image carrier and charge a surface of the electrostatic latent image carrier, and a developing part, which supplies a developer to the electrostatic latent image carrier for obtaining a developer image. The charge member includes a conductive elastic layer and a surface layer formed on a circumferential surface of the conductive elastic layer. The surface layer contains particles having an average particle size of 5 ?m-20 ?m; and a ratio of a surface area per unit area of the surface layer is in a range from 1.5 to 3.0.

Abstract: An image forming apparatus includes a photosensitive member; a corona charger, provided with an opening opposing the photosensitive member, for electrically charging the photosensitive member; image forming means for forming an image on the photosensitive member electrically charged by the corona charger; a sheet-like member for covering and uncovering the opening of the corona charger with respect to the photosensitive member; and control means for controlling a rotating operation of the photosensitive member so as to be started at a predetermined time in a period from start of an opening operation of the sheet-like member for starting image formation to end of the opening operation of the sheet-like member.

Abstract: An image forming apparatus includes a rotatable photosensitive member; charging device for electrically charging the photosensitive member by being supplied with a charging bias; a current detecting device for detecting a DC current flowing when a test bias in the form of a predetermined DC voltage biased with a predetermined AC voltage is applied to the charging device so as to cause discharging between the photosensitive member and the charging device; and a control device for controlling the charging bias on the basis of an output of the current detecting device.

Abstract: The present invention provides an image forming apparatus which includes a rotatable photosensitive member, a charging device which charges the photosensitive member, an applying unit which applies an alternating current voltage to the charging device, a processing portion which extracts a discharge current component by removing an alternating current component corresponding to the alternating current voltage from a current flowing between the photosensitive member and the charging device, and a control unit which controls a peak-to-peak value of the alternating current voltage based on the discharge current component extracted by the processing portion.

Abstract: In an image forming apparatus, a control portion forms a restoring toner image (restoring toner band) at a position, in which the refreshing toner image overlaps with a control image with respect to a longitudinal direction of a secondary transfer roller, during post-rotation after image formation in an image forming job is completed. The restoring toner band is formed in a length corresponding to 3 full circumferences of the secondary transfer roller for one-sheet image forming job, 2 full circumferences of the secondary transfer roller for 5-sheet image forming job, and one full circumference of the secondary transfer roller for 10-sheet image forming job. In the case of an image forming job on 50 sheets or more, a lowering in cleaning performance of a secondary transfer member cleaning device for the secondary transfer roller is not caused to occur, so that the restoring toner band is not formed.

Abstract: A charging voltage control method of an image forming apparatus and an image forming apparatus thereof. The charging voltage control method of the image forming apparatus includes: applying a charging voltage amount determined by referring to a basic lookup table which determines the charging voltage based on a system load; and correcting the applied charging voltage by using a first correction value which is determined based on a first correction lookup table which determines the first correction value based on a difference between a target current corresponding to the lifespan of the charging roller and a charging current.

Abstract: An image forming method and apparatus in which a protective agent is supplied to an image carrier, and the image carrier is charged by a plurality of charging units. Degrees of discharge deterioration of the surface of the image carrier in the plurality of charging units are different, and the amount of protective agent supplied to a charging portion of a charging unit, in which a degree of discharge deterioration of the surface of the image carrier is high, is large.

Abstract: An image forming apparatus including: a photosensitive member; a charging member; a developer carrier; a transfer member; a charging control unit that applies a charging bias having the same polarity as a charged polarity of the developers to the charging member; and a transfer control unit that applies a transfer bias having a reverse polarity to the charged polarity of the developers to the transfer member, wherein when the transfer control unit sets the absolute value of the transfer bias to a first value, the charging control unit sets an absolute value of the charging bias to a third value, and wherein when the transfer control unit sets the absolute value of the transfer bias to a second value, the charging control unit sets the absolute value of the charging bias to a fourth value smaller than the third value.

Abstract: This invention provides an image forming apparatus for accurately specifying the type of the apparatus without increasing cost, and a method of controlling the same. To accomplish this, an image forming apparatus of the embodiment executes a continuous image formation test to specify the model of the self apparatus when a system control unit is connected to an engine control unit. In the continuous image formation, the image forming apparatus measures the period from synchronization signal output by the engine control unit to output of the next print start request by the system control unit, and specifies the model of the self apparatus in accordance with the measured period.

Abstract: An image forming device includes a photosensitive member, a charger, an exposing unit, a developing unit and a control unit. The charger charges the photosensitive member, and the exposing unit exposes the photosensitive member to light and forms an electrostatic latent image on the photosensitive member. The developing unit develops the electrostatic latent image formed and has a developing member having a surface potential and developer charged to a polarity. The control unit applies a first voltage having a first absolute value to the charger at least during development while applying a second voltage having a second absolute value to the charger during operations other than development. The first voltage, the second voltage and the surface potential have the same polarity as the developer with the first voltage absolute value being greater than the second voltage absolute value which is greater than an absolute value of the surface potential.

Abstract: An image forming apparatus includes an image bearing member; a charging device, including a rotatable magnetic particle carrying member and electroconductive magnetic particles carried on the rotatable magnetic particle carrying member, for charging the image bearing member by contacting the magnetic particles to the image bearing member; a measuring device for measuring magnitudes of a first force in a first direction and a second force in a second direction which are produced in a contact region between the image bearing member and the magnetic particles, wherein the first direction and second direction are independent from each other; and a control device for controlling an image forming operation on the basis of the forces measured by the measuring device.

Abstract: An image forming apparatus includes an image carrier to carry a toner image, a transfer member to form a transfer nip by contacting the image carrier surface, and a power supply to output a voltage to the recording material captured in the transfer nip so as to transfer the toner image formed on the image carrier surface. The voltage is switching alternately between a voltage in the transfer direction and a voltage opposite to the voltage in the transfer direction, and a time average value (Vave) of the voltage is set to have a polarity of the transfer direction, and is set to a value in the transfer voltage side, and a change mode to change a cycle of the voltage output from the power supply can be changed based on the toner deterioration information which determines the deterioration status of the toner.

Abstract: An image forming apparatus and a control method of the image forming apparatus. The image forming apparatus includes a photosensitive medium, a charger to charge the photosensitive medium, an exposing unit to expose light to the photosensitive medium to form a latent image on the photosensitive medium, a developing unit which is disposed opposite to the photosensitive medium to develop the latent image into a visible image, a density sensing unit to sense a density of an area of the photosensitive medium, and a controller to determine whether a preset developing condition corresponds to a background image generating condition based on the density sensed by the density sensing unit and to adjust the developing condition based on the determination.

Abstract: An image forming apparatus includes a member (drum), a charging device, an exposure device, a developing device, a transfer device, a cleaning blade, a selecting device for selecting an execution mode from an image forming mode and a recovery mode, and a controller for controlling a peak-to-peak voltage applied to the charging device in the operation in the recovery mode. When the recovery mode is selected, the controller effects control so that a band-like toner image is formed on the drum and is supplied to the cleaning blade and so that a peak-to-peak voltage of the AC voltage larger than that of the AC voltage applied to the charging device in the operation in the image forming mode is applied to the charging device in a predetermined period after a leading end of the band-like toner image subjected to removal by the cleaning blade passes through the charging device.

Abstract: An image forming apparatus includes an image bearing member to bear a toner image, a transfer device to transfer the toner image onto a recording medium, and a moving device controller to control a moving device that moves the transfer device such that the moving device moves the transfer device to contact the image bearing member during transfer of the toner image on the image bearing member to the recording medium; separates the transfer device from the image bearing member as a toner patch on the image bearing member passes through the transfer area; and maintains the transfer device in contact with the image bearing member from a preceding transfer of a toner image to a succeeding transfer of a toner image during continuous printing, as at least one of areas between successive toner images on the image bearing member without the toner patch passes through the transfer area.

Abstract: According to various embodiments, there is a charging device including a first conductive layer disposed over a first dielectric layer; a second dielectric layer disposed over a first conductive layer, the second dielectric layer including a plurality of cavities, wherein each of the plurality of cavities exposes a portion of the first conductive layer; a plurality of micro-tips, wherein one of the plurality of micro-tips is disposed within each of the plurality of cavities and on the first conductive layer; a second conductive layer disposed over the second dielectric layer; and a system of interconnected air flow channels disposed in the second dielectric layer and connected to the cavities, such that air injected through an air inlet exits through the plurality of cavities. The charging device can also include one or more power supplies to apply bias voltages to the first and the second conductive layers.

Abstract: An image forming apparatus includes a photosensitive member; a charging member contactable to said photosensitive member to electrically charge said photosensitive member; applying means applying a charging bias voltage to said charging member; detecting means detecting a current flowing between said charging member and said photosensitive member; a controller for controlling said image forming apparatus to execute an operational mode for removing an electric discharge product deposited on a surface of said photosensitive member, in the case that detecting means detects a current not lower than a predetermined value when a voltage lower than a voltage at which an electric charge starts between said photosensitive member and said charging member is applied to said charging member.

Abstract: An image forming apparatus has a charging unit which charges an image carrier by applying a voltage to a charging member arranged to be in contact with the image carrier. The image forming apparatus includes an alternating voltage applying unit which generates an alternating voltage, a first voltage detection unit which detects a positive peak voltage of the alternating voltage, a second voltage detection unit which detects a negative peak voltage of the alternating voltage, a voltage amplitude determination unit which determines an amplitude value of the alternating voltage based on the positive peak voltage detected, and an alternating voltage control unit which outputs a signal which changes an output from the alternating voltage applying unit.

Abstract: A charging device includes: a charging member that faces an image carrier and charges a surface of the image carrier; a charging voltage controller that controls a charging voltage to be applied to the charging member when the surface of the image carrier is to be charged, and applies the charging voltage obtained by superposing an AC voltage which is subjected to constant-current control on a DC voltage; a variation range detector that detects a variation range of the AC voltage which changes according to the characteristic change of the charging member; and a response speed controller that reduces a response speed for the variation of the AC voltage in correspondence with the characteristic change when the variation range is larger than a predetermined set value.

Abstract: There is provided an image forming apparatus and method capable of reducing a measurement error in a measurement result of the surface potential of an electrostatic latent image formed on the surface of an image bearing member. The measurement error occurs under the influence of an electric field generated from a pre-exposed area. Consequently, miniaturization of an image forming apparatus and consistent print quality can be achieved. The image forming apparatus includes an image forming control section for determining an error correction value corresponding to the charge state of a latent image on the basis of relationships between charge states of the latent image and error correction values which have been prepared in advance, computing an error corrected potential measurement value using the error correction value and a potential measurement value, and controlling the image forming apparatus on the basis of the error corrected potential measurement value.

Abstract: An image forming apparatus includes a rotatable image bearing member; a first charging member for electrically charging the image bearing member; a second charging member, provided downstream of the first charging member with respect to a rotational direction of the image bearing member, for electrically charging the image bearing member; an applying device for applying a voltage to the first charging member and the second charging member; a detecting device for a DC current passing through the second charging member; and a controller for controlling, when an AC voltage and a DC voltage are applied to the second charging member while a DC voltage is applied to the first charging member, the DC voltage applied to the second charging member so that an absolute value of the DC current detected by the detecting device is within a predetermined range.

Abstract: An initialization method of an electrophotographic image forming apparatus includes rotating a photosensitive member to receive toner along a width of the photosensitive member prior to activation of a charging unit and to remove the toner with a cleaning unit, and activating the charging unit configured to charge the photosensitive member in response to a determination of a completion of a predetermined number of rotations of the photosensitive member.

Abstract: An image forming apparatus, including: an image bearing member; a charging device which charges the image bearing member; a developing device which develops an electrostatic image formed on the image bearing member with toner; a transferring device which transfers a toner image formed on the image bearing member by the developing device onto a recording medium; a separation charge-eliminator disposed opposite to the image bearing member, for separating the medium from the image bearing member after transfer; a current detecting device which detects a separation current flowing through the charge-eliminator; and a control device which outputs a control signal regarding the charge-eliminator based on a first current value detected by the current detecting device with a charging voltage being applied to the charging device and a second current value detected by the current detecting device with a transfer voltage being applied to the transferring device.

Abstract: An image forming device includes an image holding member and a charging unit. In a case in which an AC current, while being increased, is supplied to the charging unit in a state in which a DC voltage value and an AC voltage value applied to the charging unit are maintained, or a case in which a DC voltage, while being increased, is supplied to the charging unit in a state in which the AC voltage value applied to the charging unit is maintained, a current detection unit detects DC current values. An inflection point derivation unit derives an inflection point of a correlation line representing an correlation between the detected DC current values and the supply amounts. An execution unit executes pre-specified processing when a characteristic value of the derived inflection point reaches a pre-specified value.

Abstract: Apparatus and method for minimizing ghost defect are disclosed. Ghosting results in interdocument bands when paper size is changed and process control instability due to using the interdocument zone (IDZ) for voltage and density control. A controller retrieves feedback measurements of the IDZ and sheet zone (SZ) non-uniformity. In response to the measurements, the transfer current IDZ level is controlled to minimize differences in subsequent charging, photodischarge and development.

Abstract: In an image forming apparatus, a control portion forms a restoring toner image (restoring toner band) at a position, in which the refreshing toner image overlaps with a control image with respect to a longitudinal direction of a secondary transfer roller, during post-rotation after image formation in an image forming job is completed. The restoring toner band is formed in a length corresponding to 3 full circumferences of the secondary transfer roller for one-sheet image forming job, 2 full circumferences of the secondary transfer roller for 5-sheet image forming job, and one full circumference of the secondary transfer roller for 10-sheet image forming is job. In the case of an image forming job on 50 sheets or more, a lowering in cleaning performance of a secondary transfer member cleaning device for the secondary transfer roller is not caused to occur, so that the restoring toner band is not formed.

Abstract: An image forming apparatus includes a rotatable photosensitive member; a charging member for electrically charging the photosensitive member; a power source for applying a DC voltage to the charging member; an irradiation member for irradiating with light a surface of the photosensitive member; and a controller for controlling the irradiation of the light by the irradiation member. The photosensitive member is movable at a first speed and a second speed slower than the first speed. The irradiation of the light by the irradiation member is effected when the photosensitive member is moved at the first speed to effect image formation, and is not effected when the photosensitive member is moved at the second speed to effect the image formation.