Abstract: An image forming apparatus includes a magnetic roller voltage applier for a magnetic roller, a developing roller voltage applier for a developing roller and a controller for controlling the appliers. The controller controls the magnetic roller voltage applier to apply, to the magnetic roller, a first voltage for forcibly conveying a thin layer of toner held on the developing roller toward the magnetic roller for a first period required for one turn of the developing roller, and controls the developing roller voltage applier to apply, to the developing roller, a second voltage for causing toner on the developing roller to fly onto the image carrier for a second period when at least the forcible consumption electrostatic latent image faces a facing portion between the developing roller and the magnetic roller. At least parts of the first period and the second period are overlapped with each other.

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: An image forming apparatus includes a separating unit for performing a stripping operation of forcibly returning toner particles carried on a toner bearing member to a developer bearing member, a sheet size discriminator for discriminating whether a sheet is a standard sized sheet or a long sheet, a determiner for determining whether or not there is any blank area of a predetermined length or longer in the sub scanning direction, where no toner image is to be substantially transferred, for each long sheet, and a controller for controlling the stripping operation. The controller causes the separating unit to perform the stripping operation at a developing timing of an electrostatic latent image corresponding to the blank area to be formed on the image bearing member when the sheet is a long sheet and when the blank area of the predetermined length or longer is present.

Abstract: A developing device includes a developer bearing member for bearing a developer so as to develop an electrostatic image, a restricting member for restricting the amount of developer born on the developer bearing member, a detector for detecting information on the amount of developer existing between the developer bearing member and the restricting member, and a controller which can change a value of a voltage to be applied to the restricting member during image formation based on a result detected by the detector.

Abstract: An image forming apparatus including: a photosensitive member; a charging device; an exposure device; and a developer carrying member, wherein, when it is assumed that an image forming area, a printing portion and a non-printing portion are an area on the photosensitive member on which an image to be transferred onto a recording material is formed, an area in the image forming area to which the developer adhere and an area in the image forming area to which the developer does not adhere, respectively, the exposure device exposes the printing portion at a first laser power, exposes the non-printing portion at a second laser power smaller than the first laser power, and exposes a non-image forming area on the photosensitive member between two adjacent image forming areas at no laser power or a third laser power smaller than the second laser power.

Abstract: An image forming apparatus includes an exposure device configured to expose image bearing members charged by charging devices to form latent images on the image bearing members, and a control unit configured to, in ether one or both of an image forming unit A and an image forming unit B, adjust an amount of exposure by which the image bearing member is exposed and a charging voltage based on information about the image bearing members of the image forming units A and B. The control unit is configured to make the charging voltage and the amount of exposure in the image forming unit A different from the charging voltage and the amount of exposure in the image forming unit B.

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

Abstract: An electronic development compensation method which is broadly applicable to SCMB development includes controlling image banding by actively correcting for mechanical development errors by modulating DC bias to a magnetic brush.

Abstract: An image forming apparatus includes image forming portion, toner-disposal container, conveying portion, driving portion, load detection portion, image formation control portion, and image forming condition adjustment portion. The image forming condition adjustment portion corrects, when image forming condition does not conform to predetermined condition, the image forming condition. In a case where a drive load detected by the load detection portion becomes greater than first threshold value while the conveying portion is driven by the driving portion and the image forming operation is executed, the image formation control portion temporarily stops the image forming operation, and causes the image forming condition adjustment portion to check and correct the image forming condition.

Abstract: A representative configuration of an image forming apparatus has a plurality of developing devices, each of which develops an electrostatic latent image formed on a photosensitive drum into a toner image using developer of plural colors. The image forming apparatus includes a density sensor which detects the amount of toner of the toner image for each color. In a case where it is determined that the amount of toner of any color departs from a predetermined range based on the detection result of the density sensor, development conditions of the rest of the developing devices, other than the developing device departing from the predetermined range, are changed such that the image densities developed by the respective developing devices are equal to each other.

Abstract: An image forming apparatus includes an image carrier, a charging member, a transferring member, a first voltage applying part, a current measuring part, a fan, a cleaning member and a controlling part. The controlling part carries out an aging operation rotating the image carrier and bringing the cleaning member in sliding contact with the image carrier before forming an image. The controlling part lengthens a running time of the aging operation in a case where a current value measured by the current measuring part is equal to or less than a first threshold value when the fan blows an outside air to the image carrier and the first voltage applying part applies voltage to one of the charging member and transferring member, in comparison with another case where the current value measured by the current measuring part exceeds the first threshold value.

Abstract: An image forming apparatus includes an image carrier, a transferer to apply a constant-current controlled bias to a transfer medium to form a transfer electric field, a constant-current source configured to apply an electrical current to the transferer, an electrical characteristic detector, an environment detector, a first corrector, a second corrector, and a third corrector. The electrical characteristic detector detects an electrical characteristic value corresponding to a resistance in a current path from the constant-current source to the transferer. The environment detector detects an environmental condition inside the image forming apparatus. The first corrector corrects the electrical current based on the electrical characteristic detection and a predetermined threshold. The second corrector corrects the electrical current based on the environment detection. The third corrector sets the threshold based on the environment detection.

Abstract: An image forming apparatus and a control method for the same, which ensure acquisition of a high-quality image by controlling physical-states of toner on a developer roller based on sensed variation in states of internal components of a developer cartridge, and which enable sensing and determination of the lifespan of the developer cartridge, is provided. The control method for the image forming apparatus includes applying a current detection bias to a developer roller blade of a developer cartridge, detecting the magnitude of current of the developer roller blade when the current detection bias is applied to the developer roller blade, and variably controlling a developer cartridge bias to be applied to the developer cartridge for image formation based on the detected magnitude of current of the developer roller blade, so as to allow a target magnitude of constant current to flow through the developer roller blade during image formation.

Abstract: An image forming apparatus includes a control unit controlling first and second voltage application mechanisms and shifting a difference Vdif (=Vrs?Vdr) between Vrs and Vdr toward polarity opposite to normal charge polarity of a developer as S decreases, where S is an absolute value of a speed difference between a circumferential speed of an image bearing member, which rotates while bearing an electrostatic latent image and a circumferential speed of a developer bearing member, which rotates at a constant circumferential speed ratio with respect to the image bearing member to develop the electrostatic latent image while bearing the developer, Vdr is a voltage that the first voltage application mechanism applies to the developer bearing member, and Vrs is a voltage that the second voltage application mechanism applies to the developer supply member.

Abstract: An image forming apparatus includes an image bearing member for carrying an electrostatic latent image; a developing device, containing a developer including a toner and a carrier, for developing the electrostatic latent image carried on the image bearing member into a toner image with the developer; a supplying device for supplying the toner to the developing device; a first detecting portion for detecting information on a temperature of the developing device; a second detecting portion for detecting information on a temperature of the supplying device; and a correcting portion for correcting, when detection results of the first and second detecting portions are different from each other, an image forming condition with increase of a supply amount of the supplying device.

Abstract: An apparatus to control a printing density in an image forming device and a method thereof, capable of controlling the printing density of a printed matter according to an amount of pages for a single page and a print rate. The apparatus and method solve a problem wherein the printing density is recognized as being degraded due to an increase of pages for a single paper or a reduced print rate. The printing density is set automatically or manually, and a bias voltage applied to a developing roller is controlled according to set-up information so that the printing density is controlled.

Abstract: An image forming apparatus includes a sensor that detects a property of a developer material, a transport unit that contacts the developer material and moves the developer material toward a recording medium, and a controller that receives the data regarding the property of the developer material from the sensor unit and sets both a voltage and a velocity of the transport unit, wherein the voltage and the velocity is determined based on data regarding the detected property of the developer material received from the sensor.

Abstract: An image forming apparatus includes a charging member for charging a surface of a photosensitive member to a first potential, an exposing member for partially exposing the charged surface of the photosensitive member such that a potential of the exposed portions becomes a second potential smaller than the first potential, a developer carrier for feeding developer onto the photosensitive member, a discharging-beam member for irradiating a discharging beam onto the photosensitive member having a developer image, and a control device configured to: control a developing bias to become a third potential larger than the second potential and smaller than the first potential; and control a discharging bias such that a potential of portions on the photosensitive member where the developer image has not been formed becomes a fourth potential not smaller than the third potential and smaller than the first potential.

Abstract: A developing device of the present disclosure has a developer bearing member, a toner bearing member, a bias controller. With respect to a duty ratio of the alternating current bias of a polarity with which the toner is moved from the developer bearing member to the toner bearing member, a second duty ratio that is a duty ratio of the collection bias is set to be smaller than a first duty ratio that is a duty ratio of the development bias. When a transition is made from the development operation to the collection operation, in a state where the developer bearing member and the toner bearing member are being driven to rotate, the bias controller performs control so that the bias applier applies the alternating current bias having a third duty ratio that is smaller than the first duty ratio and larger than the second duty ratio.

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

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

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

Abstract: Methods for printing are provided. In one aspect, the method includes providing a primary imaging member having engine pixel locations with a ratio modulated difference of potentials, establishing a first development difference of potential to form a first net development difference of potential between the first development difference of potential and the engine pixel location and providing a first charged toner such that the second toner develops at the engine pixel location. Establishing a second development difference of potential that is greater than the first difference of potential proximate the engine pixel location such that a determined amount of first toner develops at the engine pixel locations according to a second net development difference of potential. Wherein the range of second toner potentials is such that a determined range of ratios of second toner amounts and the determined first toner amount provide ratio modulated differences of potential.

Abstract: Methods for printing are provided. In one aspect, the method includes providing a primary imaging member having engine pixel locations with a ratio modulated difference of potentials, establishing a first development difference of potential to form a first net development difference of potential between the first development difference of potential and the engine pixel location and providing a first charged toner such that the first toner develops at the engine pixel location according to the first net development difference of potential. Establishing a second development difference of potential that is greater than the first difference of potential proximate the engine pixel location such that a determined amount of second toner develops at the engine pixel locations. Wherein the range of first toner potentials is such that a determined range of ratios of first toner amounts and the determined second toner amount provide ratio modulated differences of potential.

Abstract: An image forming apparatus includes an image carrying member, a developer carrying member configured to carry developer to be supplied to the image carrying member, a transfer member configured to transfer a developer image formed on the image carrying member to a sheet passing between the image carrying member and the transfer member, a detector configured to detect a temperature, and a control device. The control device is configured to change, in response to a sheet interval, a developing bias to the applied to the developer carrying member from a first developing bias to a second developing bias at a changing rate based on a temperature detected by the detector, the changing rate being an amount of change in the developing bias per unit time based on the temperature.

Abstract: An image forming apparatus includes an image carrier, a developing part, a storing part and an adjusting part. The image carrier includes a surface. An electrostatic latent image formed on the surface is developed by a toner, thereby forming a toner image on the surface. The developing part contains the toner supplied from a toner cartridge and supplies the toner to the image carrier. The storing part stores information relating to a replacement rate when a first toner in the developing part is replaced by a second toner, in a case where kinds of the first toner contained in the developing part and the second toner being supplied from the toner cartridge are different. The adjusting part adjusts density of the toner image on the basis of the replacement rate when a toner cartridge containing the first toner is replaced by another toner cartridge containing the second toner.

Abstract: An image forming apparatus includes a photoreceptor, a developing apparatus, a developing bias supply power source, a control section for controlling a developing bias, a density sensor, and an arithmetic section. When an image density adjustment operation is performed, the arithmetic section determines a print-time developing bias in accordance with a detection result obtained by detecting, by the density sensor, a plurality of image density adjustment toner images formed by changing a developing bias. The print-time developing bias is set by the control section when printing is performed. also, In a case where a previous print-time developing bias falls within at least a low range of a predetermined range of the developing bias, the arithmetic section determines the print-time developing bias to a value between a reference developing bias for a target image density and the previous print-time developing bias.

Abstract: A developer supply device is provided, which includes a developer retrieving member disposed to face a developer holding surface of a developer holding member across a predetermined distance in a position downstream relative to a developer supply position where the developer holding member faces an intended device to be supplied with development agent in a direction perpendicular to a main scanning direction parallel to an axial direction of the developer holding member. The developer retrieving member is driven to rotate around an axis parallel to the main scanning direction and configured to retrieve the development agent from the developer holding surface under a retrieving electric field that is generated when a retrieving voltage is applied between the developer retrieving member and the developer holding member.

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

Abstract: An image forming apparatus is provided. The image forming apparatus includes a photosensitive member, a developing roller which carries developer and contacts the photosensitive member, and a control device which is configured to apply, to the developing roller, a developing bias having a direct current component and an alternating current component overlapped with each other so as to supply developer from the developing roller to the photosensitive member. The control device is configured to execute either one of a first mode in which an amplitude of the alternating current component of the developing bias is set with a first set value and a second mode in which the amplitude of the alternating current component of the developing bias is set with a second set value larger than the first set value, based on whether or not a temperature of the developing roller is a first predetermined value or larger.

Abstract: The image forming apparatus includes a photosensitive drum, developer bearing members to develop a latent image formed on the photosensitive drum into a toner image while bearing developer, a secondary transfer roller to transfer the toner image to a sheet, an operation apparatus to which smoothness of the sheet having the toner image transferred, and a CPU which controls to decrease fog elimination potential difference between non-image portion potential of the photosensitive drum and direct current component potential of bias applied to developer bearing members in a case that smoothness inputted to the operation apparatus is information that the smoothness of the sheet having the toner image formed is equal to or higher than a predetermined smoothness as compared to a case of being lower than the predetermined smoothness.

Abstract: An image forming apparatus is capable of executing, in non-image formation, for example, in a sheet-to-sheet interval, a developer bearing member stop mode in which the developer conveyance by a development sleeve is stopped. For example, the apparatus turns off primary transfer bias in the sheet-to-sheet interval. Even if fogging toner is no longer supplied after the development sleeve drive is stopped, the apparatus can reduce frictional force variation between the photosensitive drum and the intermediate transfer belt to prevent speed variation of the photosensitive drum or the intermediate transfer belt, thus reducing the possibility of image unevenness and out of color registration.

Abstract: An image forming apparatus includes an image bearing member on which a developer image is formed, a developer bearing member configured to develop a surface of the image bearing member, and a cleaning member configured to clean a residual developer remaining on the surface of the image bearing member, wherein, when an image forming operation is interrupted, the image forming apparatus is capable of performing a recovery operation before resuming the image forming operation, and wherein the image forming apparatus is capable of, during the recovery operation, a potential difference between a potential applied to the developer bearing member and a surface potential of a non-image area within the surface of the image bearing member greater than that during the image forming operation according to a predetermined value such that the developer on the image bearing member is moved to the developer bearing member.

Abstract: An image forming apparatus includes an image forming unit configured to form an image under a control condition and including developing device; a toner cartridge configured to supply toner to the developing device; a measuring device configured to acquire measurement data; a first memory which is provided for the toner cartridge and includes a data reference destination for obtaining the control condition and a correction value of the control condition for standard data or a plurality of control data corresponding to the measurement data; a second memory configured to store the measurement data, the standard data, one of the correction value and the control data, and the obtained control condition; and a processing mechanism configured to read the standard data and the correction value, or the measurement data and the control data and to obtain the control condition.

Abstract: An image forming apparatus according to the invention comprises a light source for emitting light in accordance with printing data, an image carrier carrying on a surface thereof a latent image based on the emitted light out of the light source, a developer carrier for developing the latent image carried on the image carrier, a supply member for supplying a developer to the developer carrier, and a controller for controlling a voltage between the developer carrier and the supply member in accordance with a light emitting amount of the light source at a prescribed use amount, for suppressing occurrences of image failures even where using different developers.

Abstract: An image forming device includes each of developing devices including an image carrying part, a charging part that charges the image carrying part, a developing part on which a developing voltage is applied and which attaches developer to the image carrying part to develop the electrostatic latent image, and a control part that controls each of the developing devices. The developers are a white developer and other color developers, one of the developing devices using the white developer being defined the white developing device, the others using the other color developers being defined the non-white developing devices, and a developing potential difference of the white developing device is smaller than other developing potential differences of the non-white developing devices, the developing potential difference being defined between the developing voltage and potential of the image carrying part of the each developing device.

Abstract: An image forming apparatus includes first photosensitive members, first chargers for charging the first photosensitive members, developer carriers for supplying developer to the first photosensitive members, a first charging-bias applying unit that applies charging biases to the first chargers, development-bias applying units for applying development biases to the corresponding developer carriers, a charging-current sensing unit that separately senses a charging current flowing in each of the first chargers, and a control unit that controls the development biases based on the sensed charging current. When a difference between a reference charging-current value and a detected charging-current value exceeds a predetermined value, if the detected charging-current value is larger than the reference charging-current value, the control unit increases an absolute value of a development bias applied to a developer carrier corresponding to the charger having the difference exceeding the predetermined value.

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

Abstract: A developing device includes a non-magnetic rotatable sleeve of a developer bearer to bear developer and a development electric field generator to generate a development electric field between the image bearer and the developer bearer by applying a development bias to the developer bearer. The developing bias is an AC bias generating an AC electric field therebetween. The magnetic carrier includes a plurality of fine particles each covered by a covering layer made of prescribed material having a volume resistivity equal to or more than 1012 [?·cm] having a prescribed particle diameter equal to or less than 100 [nm]. Each of the a plurality of fine particles has a total volume resistivity equal to or less than 105 [?·cm]. The magnetic carrier has a total volume resistivity equal to or more than 1012 [?·cm].

Abstract: A charge bias causing the surface potential of a photosensitive drum to be lower than that in image formation is applied to a charge roller during a period in which the stop position of a rotary is moved from an unknown state to a home position to cause a developing bias to be applied to a developing roller to be smaller than that in the image formation.

Abstract: An image forming apparatus includes a first rotating unit, an image carrier, an electrostatic latent image forming unit, a third rotating unit, an intermediate transfer body, first and second transfer units, and the following elements. A developing device includes a rotating body, a second rotating unit, plural developing units. A supply unit supplies a bias to a developer carrying member of each developing unit. A setting unit sets the bias to a first condition to develop the latent image of a first color at least while the latent image is being located at the developing position, and sets the bias to a second condition to suppress transferring of the toner in the subsequent developing unit to the image carrier after the second rotating unit starts rotating the rotating body from a waiting position and before stopping rotating the rotating body and locates the subsequent developing unit at the developing position.

Abstract: An image forming apparatus includes an image carrier, a developing unit that visualizes an electrostatic latent image formed on a surface of the image carrier, using a developing material, and a supply unit that supplies a periodic wave as a developing bias to the developing unit. A single period of the periodic wave is formed by a first time period in which a voltage in which a DC voltage and an AC voltage are superimposed is applied and a second time period in which only a DC voltage is applied. In addition, a count unit counts an amount of electrostatic latent images that have been formed in succession, and a control unit changes the duration of the second time period according to the amount of electrostatic latent images counted by the count unit without stopping image formation to continue the image formation.

Abstract: A bias power supply device includes: a temperature detecting unit; a control signal generation unit generating and outputting an output frequency setting signal for setting a frequency of an alternating current power in accordance with a repetition frequency and a resonance frequency signal being set at a lower or higher repetition frequency according to the measured temperature; a waveform signal generation circuit generating a waveform signal for pulse-width modulation having a time constant for rising set by capacity and resistance based on the resonance frequency signal; a modulation circuit generating a pulse-width-modulated modulation signal based on the waveform signal and the output frequency setting signal; a switching circuit driven by the modulation signal; and a transformer having a first winding and a second winding, and supplying an alternating current power with a repetition frequency of the output frequency setting signal to an external load connected to the second winding.

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: A toner image for measurement of an area coverage modulation of 90% or more is formed on a photosensitive drum in a non-image formation, and a setting condition for defining a developability of a toner image in an image formation is set so that a detection result of an optical sensor detecting the toner image for measurement becomes a preset target value. The target value is set to be lower as a value of the setting condition increases from a lower side to a higher side of the developability. The target value is set so that a color difference ?E of an image having half the maximum image density obtained after the setting condition is set with respect to an image having half the maximum image density obtained after the setting condition is set in a setting mode with use of unused developer is 6.5 or less.

Abstract: A high voltage power supply includes a developer carrier, an image carrier, a developing control unit, a load detection unit, a variation detection unit, and a voltage correction unit. The developing control unit applies a developing bias voltage to the developer carrier and thereby supplies the developer to the image carrier and develops an electrostatic latent image. The variation detection unit detects the variation in capacitance between the developer carrier and the image carrier detected by the load detection unit. The voltage correction unit corrects the developing bias voltage by decreasing the developing bias voltage as the variation increases, and increasing the developing bias voltage as the variation decreases.

Abstract: An image forming apparatus includes a photosensitive member; a charging device for electrically charging the photosensitive member; an exposure device for exposing to light the photosensitive member charged by the charging device to form an electrostatic image on the photosensitive member; a developing device for developing the electrostatic image on the photosensitive member with toner to form a toner image; a transfer portion for transferring the toner image from the photosensitive member onto an image receiving member; a toner charging portion, disposed upstream of the charging device and downstream of the transfer portion with respect to a rotational direction of the photosensitive member, for electrically charging the toner remaining on the photosensitive member without being transferred onto the image receiving member; and control portion for controlling the charging device and the exposure device so that a stripe-shaped electrostatic image is repeatedly formed in substantially parallel to a longitudina

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: A development device includes a developer container, a rotary developer carrier that is disposed facing the latent image carrier and including multiple outer electrodes arranged in a circumferential direction of the developer carrier, an inner electrode electrically insulated from the multiple outer electrodes, an insulation layer disposed between the inner and outer electrodes, and a surface layer overlaying the outer electrodes and electrically insulating the multiple outer electrodes from each other, a bias power source to generate electrical fields that change with time by applying a first and second bias voltages to the inner and outer electrodes, respectively, an electrical field adjuster to regulate the electrical fields in accordance with a thickness of the surface layer of the developer carrier, and a controller.

Abstract: An image forming apparatus of a representative configuration of the present invention includes a photosensitive drum, which carries an electrostatic latent image, and a developing sleeve, which carries a two-component developer and develops the electrostatic latent image on the photosensitive drum into a toner image. Moving directions of the photosensitive drum and the developing sleeve are opposite at an opposing portion in a developing device having a speed changing portion, which changes the driving speed of the developing sleeve, and a controller, which switches a target speed of the developing sleeve so that it is driven at a second velocity, before it is driven at the first velocity set in a lower speed mode, when the lower speed mode is executed in which the photosensitive drum is driven at a lower speed than in the normal image forming.