Abstract: An image forming apparatus includes: a first photosensitive member; a second photosensitive member; a third photosensitive member; a first scorotron-type charger that is configured to charge the first photosensitive member; a second scorotron-type charger that is configured to charge the second photosensitive member; a third scorotron-type charger that is configured to charge the third photosensitive member; a first voltage applying circuit, which is connected to the first scorotron-type charger, and which is configured to apply a voltage to the first scorotron-type charger; and a second voltage applying circuit, which is commonly connected to the second scorotron-type charger and the third scorotron-type charger, and which is configured to apply a voltage to the second scorotron-type charger and the third scorotron-type charger.

Abstract: An electrostatic charging apparatus, includes: an endless-shaped electrostatic charging belt having electrical conductivity, the electrostatic charging belt being arranged in a state of having a predetermined contact zone being in contact with a moving to-be-charged body and moving in the same direction as a moving direction of the to-be-charged body; and plural electrode members including at least a first electrode member and a second electrode member, the plural electrode members being provided inside the electrostatic charging belt, and the first and second electrode members being provided on both sides of the contact zone of the electrostatic charging belt in the moving direction thereof so as to press the electrostatic charging belt against the to-be-charged body and forming gaps that permit electric discharge between the to-be-charged body and the electrostatic charging belt, the gaps being adjacent to the respective sides of the contact zone of the electrostatic charging belt.

Abstract: An image forming apparatus includes a drum; a charging member; a charging bias applying device; an image forming device; a detecting device for detecting a current passing between the charging member and the drum; an executing device for selectively executing a first mode in which the charging bias of a first frequency is applied to form the image on the drum rotated at a first speed and a second mode in which the charging bias of a second frequency is applied to form the image on the drum rotated at a second speed; a calculating device for calculating information indicating a relationship between an output of the detecting device when the AC voltage of the first frequency is applied and an output of the detecting device when the AC voltage of the second frequency is applied; and an adjusting device for adjusting a peak-to-peak voltage to be applied to the charging member in the first mode based on the output of the detecting device obtained by applying the AC voltage of the first frequency to the charging me

Abstract: Provided is an image forming apparatus including: a rotatable image carrier; a protective agent supplying unit supplying a protective agent to the image carrier; a first charging unit charging the image carrier to the same polarity as a regular charging polarity of a toner; a second charging unit charging the protective agent supplied to the image carrier to the opposite polarity to the regular charging polarity of the toner; an exposure unit forming an electrostatic latent image on the image carrier; a development unit developing the electrostatic latent image of the image carrier; and a transfer unit transferring the image of the image carrier, wherein the second charging unit is disposed between the protective agent supplying unit and the development unit.

Abstract: A charging device includes: a charging member; a charging power source that applies a charging voltage to the charging member; a temperature dependence storage unit that stores preset temperature dependence; a humidity dependence storage unit that stores preset humidity dependence; an ambient temperature detecting unit that detects an ambient temperature in the vicinity of the charging member; an ambient humidity detecting unit that detects an ambient humidity in the vicinity of the charging member; and a charging voltage control unit that applies the charging voltage to the charging member according to (i) a constant current value that is determined according to the temperature dependence as corresponding to the detected ambient temperature or (ii) a constant current value that is determined according to the humidity dependence as corresponding to the detected ambient temperature and the detected ambient humidity.

Abstract: An image forming apparatus includes a rotatable image bearer for carrying a toner image, a charger for contacting a surface of the image bearer, a cleaning blade for contacting the image bearer surface to remove toner thereon after toner image transfer onto a transfer material, and a controller for controlling a voltage applied to the charger. The controller applies to the charger a first potential which includes a peak-to-peak voltage larger than a discharge starting voltage in an image forming operation, and applies to the charger a second voltage which includes a peak-to-peak voltage smaller than the discharge starting voltage, for at least one full rotation of the image bearer, after completion of image formation and before an AC voltage component applied to the charger is shut off.

Abstract: An image forming apparatus may include a first and second mode. In the first mode, the image forming apparatus uses a second charging member to charge toner that remains on an intermediate transfer member and then transfers the charged, remaining toner to an image carrier in a primary transfer portion. In the second mode, the image forming apparatus transfers the remaining toner adhered to the second charging member in the first mode to the intermediate transfer member. Also in a second mode, the image forming apparatus controls so that a surface potential of the image carrier that reaches the primary transfer portion at a timing at which the remaining toner transferred to the intermediate transfer member passes through the primary transfer portion has a same polarity as that of a surface potential of the image carrier in the first mode and also has an absolute value smaller than that thereof.

Abstract: An image forming apparatus includes a rotatable photosensitive member chargeable by a charging member; an applying device for applying to the charging member a charging bias; an image forming device for forming a toner image on the photosensitive member; a setting device for setting a first frequency of a first charging bias in a first rotation speed mode and for setting a second frequency of a second charging bias in a second rotation speed mode; a detector for detecting current passing between the charging and the photosensitive members during application of a test bias to the charging member; and an adjusting device for adjusting the second charging bias based on an output of the detector when the photosensitive member is rotated at a first speed and a test bias having the second frequency is applied to the charging member when switching from the first to the second rotation speed modes.

Abstract: An image forming apparatus including a latent image bearing member a surface of which is rotated, a charging device, an irradiating device, a developing device, a transfer device, and a control unit. The control unit controls the image forming apparatus to perform subsequent image formation in accordance with a subsequent image forming request when determining that the subsequent image forming request is present at a predetermined determination time after completion of previous image formation, and controls the image forming apparatus to shut down certain predetermined operations including at least rotation of the surface of the latent image bearing member and application of a charging bias from the charging device and a developing bias from the developing device in accordance with a predetermined shutdown sequence when determining that the subsequent image forming request is not present at the predetermined determination time.

Abstract: An image forming apparatus includes: a calculating device configured to, in a testing mode to replace a discharge path between a charging wire and a grid of a charger with a testing resistor having a predetermined resistance, calculate a charge voltage using the resistance of the testing resistor and a detection value by a grid-current detecting circuit; and a controller configured to, in an image forming mode to actually form an image, detect the charge voltage from a feedback voltage using a relation between a value of the feedback voltage which is detected by a charge-voltage detecting circuit in the testing mode and the charge voltage calculated by the calculating device.

Abstract: In an image forming apparatus, when backside contamination of a recording material occurs, a control portion carries out control so that a plurality of restoring toner bands having a length L1 longer than a circumference L3 of a secondary transfer roller is formed at an interval L2 at positions in which the restoring toner bands can overlap with control images with respect to a longitudinal direction of the secondary transfer roller and then is transferred onto the secondary transfer roller through an intermediary transfer belt. The restoring toner bands transferred onto the secondary transfer roller stagnate on a fur brush rubbing against the secondary transfer roller to remove an electric discharge product deposited on the secondary transfer roller. The toner stagnating on the fur brush is inverted in charge polarity and then is re-transferred onto the intermediary transfer belt through the secondary transfer roller.

Abstract: An image forming apparatus includes: a photosensitive member; a scorotron charger; a developing device; a voltage application circuit; a constant-voltage circuit; a first control device; a deboost circuit; and a second control device, wherein the deboost circuit has a circuit configuration in which a resistor and a control transistor are connected in series with each other, and deboosts the grid voltage by a voltage drop of the resistor to generate the developing voltage, and the second control device provides a control signal to the control transistor to control a current flowing in the resistor, thereby controlling the level of the developing voltage.

Abstract: An image forming apparatus including: one or a plurality of photosensitive drums; a plurality of chargers each having a grid, a voltage applying unit generating a charging voltage; a plurality of grid constant voltage circuits, each of the plurality of grid constant voltage circuits including: a voltage detecting unit that detects a voltage based on a grid voltage which is generated in the grid; a first current detecting unit detecting a first current; a voltage control line making the grid voltage constant; and an operation control device performing a feedback control such that the detected voltage has a predetermined voltage value; at least one of a second current detecting units detecting a second current flowing; and a controller controlling the voltage applying unit such that a sum of the first current and the second current corresponding to one of the plurality of chargers becomes a predetermined current value.

Abstract: An image forming apparatus including an image carrier that includes a photoconductive layer on which an electrostatic latent image is formed, a charging member that comes in contact with the image carrier and charges the photoconductive layer, and a feeding section that supplies a current to the charging member by applying a vibration voltage with an alternating current component superposed on a direct current component, wherein the alternating current component may contain a first amplitude that eliminates charging non-uniformity when the vibration voltage is applied with a uniform amplitude and a second amplitude that is smaller than the first amplitude.

Abstract: A mode in which a toner image formed on an intermediate transfer belt passes through a primary transfer portion without a toner image being transferred from a photosensitive drum onto the intermediate transfer belt is provided. In the mode, an area of the photosensitive drum that passes through the primary transfer portion while the toner image is passing through the primary transfer portion is defined as a first area. When the first area passes through a charging position, a charging bias is adjusted so that the occurrence of an image defect is prevented.

Abstract: An image forming apparatus includes an image bearing member; a first charging member for electrically charging the image bearing member by being supplied with an oscillating voltage in the form of a DC voltage biased with a common AC voltage during image formation; a second charging member, provided downstream of the first charging member with respect to a movement direction of the image bearing member, for electrically charging the image bearing member by being supplied with the DC voltage and the common AC voltage during the image formation; detecting portion for detecting an AC current passing through the second charging member; and a setting portion for setting, on the basis of a detection result of the detecting portion when a predetermined AC voltage is applied to the second charging member during non-image formation, the common AC voltage applied to the first charging member and the second charging member during the image formation so that a discharge current between the second charging member and the

Abstract: An image forming apparatus, includes: at lease one photosensitive element; a plurality of chargers configured to charge the at lease one photosensitive element; a voltage applying circuit commonly connected to the plurality of chargers and configured to apply a voltage to the plurality of chargers; a current detecting unit configured to detect a current sum of current that flows to the plurality of chargers from the voltage applying circuit; and a control device configured to control the voltage applying circuit so that the current sum detected by the current detecting unit becomes equal to or larger than a reference value.

Abstract: An image forming apparatus capable of suppressing occurrences of image defects and maintaining the image density constant while improving the development ability. The image forming apparatus includes a photosensitive drum on which an electrostatic latent image is carried, a developing sleeve on which developer is carried, an AC high-voltage drive circuit, an AC transformer, a DC high-voltage circuit, a p-p voltage detection circuit, and a CPU. The p-p voltage detection circuit converts a peak-to-peak voltage across a capacitor into a DC voltage which is taken out as a capacity detection signal. Based on the capacity detection signal output from the p-p voltage detection circuit, the CPU changes an image formation condition, e.g., a set value of a developing bias voltage.

Abstract: A bias corrector conducts a first bias correction calculation by performing first through third calculations. The first calculation compares a stored target charging current value to a first charging current value detected when a first charging bias was applied by a bias applying device. The second calculation is performed repeatedly to calculate a second charging bias based on the comparison result and then to compare the target charging current value to a second charging current value detected by the current detector when the second charging bias was applied by the bias applying device. The third charging bias is calculated based on the comparison result. A second bias correction calculation then is conducted to correct the charging bias obtained as a result of the first bias correction calculation based on photoconductor information detected by a photoconductor information detector.

Abstract: An image forming apparatus includes an image carrier configured to carry an image and a charger to which a direct current voltage overlapped with an AC voltage is applied as a charging bias to charge the image carrier. The charger is positioned in contact or contactlessly with the image carrier. The AC voltage applied to the charger in an adjustment of the AC voltage is not less than twice a charging start voltage Vth at which the image carrier starts to be charged.

Abstract: The image forming apparatus calculates a surface voltage of an image bearing member based on a first charge start voltage, which is obtained when a first voltage application section applies a first DC voltage to a charge section, and a second charge start voltage, which is obtained when a second voltage application section applies a second DC voltage to the charge section. This allows a high-quality image to be formed irrespective of a change in circumstance or drum layer thickness.

Abstract: Certain embodiments provide an image forming apparatus including: an image carrier; a latent image forming unit; a developing unit; a fixing unit; a toner cartridge; a battery in the toner cartridge; a temperature sensor in the toner cartridge driven by the battery; a first controller which causes the temperature sensor to measure an ambient temperature periodically in the toner cartridge and be supplied with power from the battery; a recording medium which is provided in the toner cartridge and records a result of measurement by the temperature sensor in timing controlled by the first controller; and a second controller which reads out information recorded in the recording medium, and changes an operating condition of the latent image forming unit, the developing unit and the fixing unit according to a state of preservation of the supply of toner, based on the information.

Abstract: Certain embodiments provide an image forming apparatus comprising an image forming part, a detection part, an arithmetic part, a storage device and an image quality maintaining control part. The image forming part forms an image quality maintaining adjustment pattern on a transfer belt to convey a sheet. The detection part detects the image quality adjustment pattern. The arithmetic part calculates, based on a detection result of the image quality maintaining adjustment pattern obtained by the detection part, image quality maintaining information for forming an image of desired image quality. The storage device stores the image quality maintaining information before the image forming apparatus transitions to a sleep mode. The image quality maintaining control part reads the image quality maintaining information from the storage device and controls the image forming part based on the read image quality maintaining information before the image forming apparatus returns after the sleep mode is released.

Abstract: A maintenance system includes a maintenance device and a control device that controls the operation of the maintenance device. The control device is configured to activate the maintenance device automatically when a numerical value associated with the operation of a maintenance target device reaches a predetermined threshold value and to activate the maintenance device when it receives an instruction from a user. When the control device is instructed to activate the maintenance device by an instruction from the user, the control device changes the preset threshold value such that the operation interval of the maintenance device becomes smaller.

Abstract: An image forming apparatus includes: a first photosensitive drum for a monochrome printing mode; second and third photosensitive drums for a color printing mode; a moving unit moving a medium from the first photosensitive drum via the second photosensitive drum to the third photosensitive drum; charger devices for charging the photosensitive drums; transfer devices for transferring developer images on the photosensitive drums to the medium; and a control unit configured to control charging biases of the charger devices and transfer biases of the transfer devices. The control unit executes, in the monochrome printing mode, an energy saving control in which absolute value of charging bias applied to the charger device for the third photosensitive drum is smaller than an absolute value of a charging bias applied to the charger device corresponding to the second photosensitive drum.

Abstract: A charge roller wiper for photoconductor unit for forming a toner image in an image forming device. The photoconductor unit comprises a photoconductor drum, a charge roller and a first charge roller wiper. The photoconductor drum receives toner particles for forming the toner image that is transferred onto a media sheet. The charge roller charges the photoconductor drum. A first charge roller wiper is disposed substantially parallel to path along which the charge roller moves between a working position and a storage position. The first charge roller wiper is configured to peripherally contact and clean the charge roller when the charge roller assumes a working position. A second charge roller wiper may be provided adjacent the storage position and disposed substantially perpendicular to the first charge roller wiper and directly in the path along which the charge roller moves.

Abstract: An image forming apparatus includes a rotatable image bearing member configured to bear an electrostatic latent image, a plurality of development devices including a developer bearing member configured to bear a developer for developing the electrostatic latent image, a rotatable development device supporting member configured to support the plurality of development devices. In the image forming apparatus, the developer bearing member is configured to execute development while contacting the image bearing member at a development position via the developer, rotating in the same direction as rotating direction of the image bearing member at the development position, and rotating at a speed faster than a surface speed of the image bearing member.

Abstract: An image forming device has: an image forming body on which an image is formed in a state in which the image forming body is charged; a charging device having plural discharge portions, and charging the image forming body by discharging of plural discharge portions; and a control section that, when forming the image on the image forming body, operates the plural discharge portions, and when not forming the image on the image forming body, switches between a state of operating some of the plural discharge portions and decreasing output of or stopping the discharge portions other than the some discharge portions, and a state of operating some other of the plural discharge portions and decreasing output of or stopping the discharge portions other than the some other discharge portions.

Abstract: An image forming apparatus includes an electrostatic latent image forming unit, a developing unit, an apparatus information acquisition unit to acquire apparatus information relating to the image forming apparatus, a toner image condition information acquisition unit using the apparatus information and acquiring toner image condition information relating to a condition at a time of toner image formation by the electrostatic latent image forming unit and the developing unit, a reference toner image forming unit controlling the electrostatic latent image forming unit and the developing unit based on the toner image condition information and forming a reference toner image on the image carrier, a toner adhesion amount information acquisition unit to acquire information relating to a toner adhesion amount in the reference toner image, and a supply amount correction unit using the information relating to the toner adhesion amount and correcting a toner supply amount to the developing unit.

Abstract: An image forming apparatus of the present invention has first and second image carriers that are configured by positively-charged single layer type electrophotographic photoreceptors, and a controller that controls an operation for charging or destaticizing the circumferential surfaces of these image carriers. The controller switches between a first mode for causing the first and second image carriers to perform image formation while rotating these image carriers, and a second mode for causing only the first image carrier to perform image formation while rotating the first and second image carriers. In the second mode, the second image carrier is applied with a charging bias and subjected to a destaticizing operation without undergoing a developing operation. The first image carrier is applied with the charging bias and subjected to the developing operation and the destaticizing operation.

Abstract: An image forming apparatus for printing an image on a medium, comprising: a first image carrier; a second image carrier disposed downstream of the first image carrier in a traveling direction of the medium; a first charging member configured to charge the first image carrier; a second charging member configured to charge the second image carrier; and a control unit configured to execute a monochrome printing mode in which a monochromic image is formed on the medium using the first image carrier and the first charging member and a color printing mode in which a color image is formed on the medium using the second image carrier and the second charging member. In the monochrome printing mode, the control unit makes an absolute value of an electric surface potential of the second image carrier larger than an absolute value of the electric surface potential of the first image carrier.

Abstract: To provide: a charge control agent having negative chargeability, which contributes to environmental conservation and the like to an increased degree, has high performance (high charge amount, quick rise-up of charge, excellent stability with time, and high environmental stability), and has improved dispersibility; a toner for developing an electrostatic charge image containing the charge control agent; and an image forming method and an image forming apparatus each using the toner for developing an electrostatic charge image. A charge control agent for controlling a charged state of powder, characterized by including one or more units each represented by the following chemical formula (1) in a molecule.

Abstract: According to one embodiment, an image forming apparatus includes: a charging device configured to apply a voltage to a photoconductive drum to set the photoconductive drum to surface potential V0; a laser-beam irradiating unit configured to form an electrostatic latent image having potential Ver on the photoconductive drum; a neutralizing section configured to generate an electrostatic latent image for detection having the potential Ver on the photoconductive drum; a surface-potential detecting section configured to detect the surface potential V0 of the photoconductive drum; a density detecting section configured to detect printing density of a test patch for density measurement; and a control section configured to control, when a contrast potential Vc is adjusted, the surface potential V0 on a negative side at potential equal to or larger than a threshold.

Abstract: An image forming apparatus according to an embodiment includes a charging device that charges an electric charge to an image carrier, a developing device supplying the image carrier with a developer, and a transfer device that transfers a toner image formed on the image carrier by a developing device onto a recording medium. The apparatus further includes a control unit, discriminates between a first mode of forming an image on a first recording medium of a first thickness and a second mode of forming an image on a second recording medium thinner than the first recording medium to control a developing contrast electric potential, and controls a magnitude of the developing contrast electric potential in the second mode so as to be lower than the first mode.

Abstract: An image forming apparatus and a control method thereof are disclosed. A charge unit charges a surface of an organic photo conductor (OPC) to a predetermined electric potential. A developing unit develops an electrostatic latent image formed on the surface of the OPC by coating a developer on the same. A power supply unit supplies power to the charge unit and the developing unit. A control unit regulates the power supplied to the charge unit and the developing unit. After a developing process in the developing unit, the control unit regulates the power applied to at least one of the charge unit and the developing unit so as to collect a residual developer on the surface of the OPC to the developing unit. Accordingly, contamination of the charge unit and the transfer unit can be prevented and an image of a good quality can be achieved.

Abstract: A system and method by which, in photoreceptor devices that use non-contact charging, an impending failure of a photoreceptor can be accurately estimated based on a determined thickness of a charge transport layer in the photoreceptor. The systems and methods may include measuring current delivered to the photoreceptor charge transport layer, measuring voltage of the photoreceptor transport layer, determining a slope of the charge device, determining the thickness of the charge transport layer based on at least one of the measured current value, voltage value, or charge device slope, and determining a photoreceptor replacement interval based on the determined thickness.

Abstract: In the case where image formation is performed by using a part of a plurality of image forming units, an associated image bearing member of a remaining part of the plurality of image forming units is rotated together with an intermediary transfer member or a recording material carrying member while a voltage of a polarity opposite to that of polishing particles is applied to an electric charge imparting member.

Abstract: An image forming apparatus has a job-content recognition device for judging whether a number inputted as the number of print copies to be made is larger or smaller than a predetermined reference value; a print-data recognition device for judging whether or not inputted print data include image data and/or graphic data; and a control device for controlling executions of image stabilization control in a printing section. The control device sets a predetermined period as intervals among executions of the image stabilization control, and sets a period shorter than the predetermined period as the intervals among executions of the image stabilization control when the number inputted as the number of print copies to be made is larger than the predetermined reference value and also the inputted print data include image data and/or graphic data.

Abstract: An image forming apparatus includes a movable image bearing member; charging means for electrically charging the image bearing member; voltage applying means for applying to the charging means an oscillating voltage including an oscillating component and a constant component in one cycle; discharging means for selectively discharging an electrically charged surface of the image bearing member to form an electrostatic latent image; and changing means for changing an application time of the constant component during the one cycle depending on a spatial frequency, with respect to a movement direction of the image bearing member, of the electrostatic latent image to be formed.

Abstract: An image forming apparatus which predicts VL fluctuations of a photosensitive drum in consideration of a double-sided print mode, and performs an image formation control based on the prediction, and thus always obtains a stable density image. The image forming apparatus performs an appropriate image formation control by controlling an image forming condition based on a photosensitive member rotation time, a photosensitive member stop time, a temperature of an atmospheric environment, an absolute humidity of the atmospheric environment, and whether an image formation that precedes a subsequent image formation is performed in single-sided printing or double-sided printing.

Abstract: An image forming apparatus including a photosensitive member, a charging apparatus to charge a surface of the photosensitive member when applied with a charging voltage, and an exposure apparatus to expose the surface of the photosensitive member after being charged to form an electrostatic image. A developing apparatus attaches a developer to the electrostatic image and develop the electrostatic image as a developer image when applied with a development voltage. An environment measuring apparatus measures information regarding temperature and a time information obtaining apparatus obtains information regarding a photosensitive member rotation time that represents a time during which the photosensitive member is rotated, and information regarding a photosensitive member stop time that represents a time during which the photosensitive member is stopped. A control apparatus controls an image formation condition based on a control mode.

Abstract: An image forming apparatus includes a photosensitive member; a charging device; an exposure device device; a developing device; a transfer charger; a pre-exposure device; a current detector; a calculating device; and a correcting device. The calculating device determines a property formula on the basis of currents, detected by the current detector, flowing between said transfer member, or the charging device, and an area of the photosensitive member charged by the light discharger. The calculating device calculates a correction amount of the correcting device on the basis of the property formula and a current flowing between said transfer member and an area of the photosensitive member charged by the charging device which is supplied with a predetermined DC voltage with discharging by the pre-exposure device.

Abstract: A method creates a printing image charge on a photoreceptor printing region of a photoreceptor within a printing apparatus and, simultaneously with the creating of the printing image charge, charges source patches on the photoreceptor outside the photoreceptor printing region. The method then transfers developer material from a donor roll to the photoreceptor. The source patches cause developer material to be removed from areas of the donor roll outside a donor roll printing region to create developer material-depleted regions. The method then reloads the donor roll with developer material using a magnetic brush and evaluates a reload function of the donor roll by characteristics of developer material on target patches with developer material in areas of the non-printing region of the photoreceptor adjacent the target patches. The method then alters the printing image charge to maintain the reload function within a predetermined range.

Abstract: An image forming apparatus includes a charging device, an image bearing member, an electrostatic image forming device, a development device including a developer bearing member, a transfer device, and a controller. The controller controls a potential of the image bearing member such that, during image formation to form an image on a recording material having a predetermined size, an absolute potential value (V1) of a region on a surface of the image bearing member outside a region corresponding to a passage region for a recording material in a width direction orthogonal to a movement direction of the surface of the image bearing member, an absolute potential value (V2) of a non-image portion in the region corresponding to the passage region for the recording material, and an absolute potential value (Vdc) of the developer bearing member satisfy the following condition: Vdc<V1<V2.

Abstract: The present invention provides a method and apparatus for forming an image. A controller manages a charger and a developing bias voltage to increase an absolute value of the charging voltage to an image-bearing member and an absolute value of a developing bias voltage to a developer-bearing member to predetermined values in a plurality of steps. The controller controls the developing bias voltage applied to the developer-bearing member; wherein the following relation holds in each of the plurality of steps: |VD|>|Vi|, where VD represents a developing bias voltage applied to the developer-bearing member and Vi represents a charged potential of the image-bearing member. This invention is especially useful for mono-component development using DC voltage as a development driving mechanism.

Abstract: The image forming apparatus including: a photoconductor provided with a charge generation layer and an overcoat layer; a first charging unit charging the photoconductor when an image is formed; an exposure unit irradiating the photoconductor with light having a wavelength to which a relative sensitivity of the charge generation layer is larger than a relative sensitivity of the overcoat layer; a development unit developing an electrostatic latent image formed on the photoconductor by the first charging unit and the exposure unit with toner; a transfer unit transferring an image developed on the photoconductor to a medium; a light irradiation unit irradiating the photoconductor with light having a wavelength to which the relative sensitivity of the overcoat layer is larger than the relative sensitivity of the charge generation layer; and an erasing unit erasing a charge from the photoconductor irradiated with light by the light irradiation unit.

Abstract: An image forming apparatus includes a high voltage generating circuit 91 that applies an oscillating voltage in which a DC voltage and an AC voltage are superimposed on each other, to a charging member 42 disposed in contact with an image carrier 41; a voltage control portion 96 that controls a peak-to-peak voltage of the AC voltage to a target voltage value; and an initial voltage adjusting portion 95 that sets a target voltage value based on a DC current value between the image carrier 41 and the charging member 42 which is detected by a current detecting portion 92. When an environmental condition which is used when the target voltage value is set changes, the initial voltage adjusting portion 95 performs an interrupt operation during an image forming process.

Abstract: Provided is an image forming apparatus capable of performing stable charging and thus stable image formation over a long term by changing a charge control method based on various environments. An engine control section serves as a first applied voltage determining unit, obtains a relationship between an applied voltage and a discharge current amount to a charging roller, and determines a voltage value of an applied voltage corresponding to a predetermined discharge current amount. The engine control section serves as a second applied voltage determining unit and determines a voltage value of a voltage to be applied to the charging roller based on the environment information detected by the environmental sensor. The engine control section selects, as the voltage to be applied to the charging roller, any one of the voltage values determined by the first and the second applied voltage determining units based oh the environment information.

Abstract: An image forming apparatus includes: an image bearing body on which surface a solid lubricant is supplied, forming and bearing an image on the surface; a charging member to which a voltage is applied, being in contact with the image bearing body to impart a charge; a voltage applying section that applies the voltage to the charging member, capable of switching the voltage between superimposed voltage on which DC voltage and AC voltage are superimposed and non-superimposed voltage including only DC voltage; an image forming section that forms a toner image; a transfer device that transfers the formed toner image to a transferring body; a cleaning member that contacts the image bearing body to scrape unnecessary substance from the surface; and a voltage switching section that switches the voltage applied to the charging member between the superimposed voltage and the non-superimposed voltage according to an amount of the solid lubricant.

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.