Abstract: In an image forming apparatus, a determiner determines a target amount of transfer current based on first and second algorithms each representing a relation between an image area rate of a latent image bearer in the vicinity of an exit of a transfer nip and a target amount of transfer current to be provided to a nip creating member. The first algorithm is utilized in a second transfer step when the image area rate falls within a typical range from the lower limit (a %) to the upper limit (b %). The first algorithm decreases the target amount as the image area rate increases within that range.

Abstract: An image forming apparatus includes an image bearing member that bears a toner image; a transfer member that faces the image bearing member, nips a recording medium together with the image bearing member, and allows the recording medium to pass therebetween; a transfer-bias applying unit that applies transfer bias voltage to generate an electric field between the transfer member and the image bearing member; a cleaning member that is disposed in contact with the transfer member and removes toner from the transfer member; a cleaning-bias applying unit that applies cleaning bias voltage between the cleaning member and the transfer member; a transfer-toner-amount estimating unit that estimates an amount of toner to be transferred from the image bearing member to the transfer member when the recording medium does not pass therebetween; and a cleaning-bias controller that controls the cleaning bias voltage in correspondence with the estimated amount of toner.

Abstract: Disclosed herein are an image forming apparatus and a control method thereof. The image forming apparatus includes a plurality of photoconductors, a transfer belt, a plurality of transfer rollers arranged in parallel with the plurality of photoconductors, and a controller rotating the transfer belt under the condition that at least one of the plurality of transfer rollers presses the transfer belt toward at least one of the plurality of photoconductors, interrupting power transmitted to the transfer belt to cause at least another of the plurality of transfer rollers to press the transfer belt toward at least another of the plurality of photoconductors, standing by until rotation of the transfer belt is stopped, after interruption of the power, and controlling the at least another of the plurality of transfer rollers so as to press the transfer belt toward the at least another of the plurality of photoconductors.

Abstract: A transfer device includes image bearing members, an intermediate transfer belt, transfer members, a transfer bias applying unit and a bias control unit. The transfer bias applying unit applies a transfer bias to the transfer. The bias control unit causes a transfer bias having a polarity opposite to that of the toner to be applied to a first transfer member during the transfer process in the first transfer nip and during an adjacent transfer process which is the non-transfer process in the first transfer nip and the transfer process in a second transfer nip adjacent to the first transfer nip. Further, the bias control unit causes a transfer bias having the same polarity as that of the toner to be applied to the first transfer member during an adjacent non-transfer process which is the non-transfer process in the first transfer nip and the non-transfer process in the second transfer nip.

Abstract: An apparatus includes: a transfer unit configured to transfer recording agent onto a transfer sheet to print input data; an acquisition unit configured to acquire, when the transfer unit transfers and when it is detected that processing is to be performed due to which time is extended that is taken from ending processing on the transfer sheet to starting the processing on a following transfer sheet, the time generated due to performance of the detected processing; a generation unit configured to generate, when the acquired time is longer than a previously set time, a patch pattern on the transfer sheet; and a correction unit configured to correct output image density using the generated patch pattern.

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 includes a toner image forming unit that forms and continuously transfers a toner image based on image data onto a transported sheet from the front to the rear in a sheet transport direction as the sheet is transported, a fixing unit positioned downstream of the toner image forming unit in the transport direction and that fixes the transferred toner image onto the sheet, an image determining unit that determines whether the formed toner image is a scattering toner image that causes toner scattering during the transfer, and a speed controlling unit that controls, when it is determined that the toner image is a scattering toner image, a transport speed of the sheet and a transfer speed of the toner image to the sheet such that the speeds are slower than those when it is determined that the toner image is not a scattering toner image.

Abstract: An image forming apparatus and a method of controlling the same is provided. A plurality of cells formed at the surface of a transfer roller is filled with a developing agent to initialize the transfer roller, thereby suppressing contamination and electrical non-uniformity of the transfer roller. A method of controlling an image forming apparatus includes determining whether a transfer roller mounted in the image forming apparatus is a new one and, upon determining that the transfer roller is a new one, feeding a developing agent to the surface of the transfer roller and filling a plurality of cells formed at the surface of the transfer roller with the developing agent to initialize the transfer roller.

Abstract: An image processing apparatus may include a storage unit, a generation unit, a recording unit, and a transmission unit. The storage unit is managed to allow access from an external information processing apparatus. The generation unit generates image data for audit for auditing the image data later. The image data is generated by a reading unit reading a document or is input. The recording unit records the image data for audit generated by the generation unit. The transmission unit transmits, to the external information processing apparatus, information about the image data in which the image data for audit is recorded by the recording unit among the image data stored in the storage unit in a case where a request for referring to the storage unit is received from the external information processing apparatus.

Abstract: Printing modules are provided. One embodiment of the printing module is controlled to cause a writer to cause the print image to be generated so that the print image is moved along a printing path through the printing area so that despite any possible variations in the location of the print image or the cross edge of the receiver, the print image is being transferred as the cross edge of the receiver is moved through the printing area by a receiver transport system of a printer and so that the print image is transferred to either the receiver or to the sheet.

Abstract: The image forming apparatus includes a discharge execution section for forcedly discharging toner from a developing device and forming a toner image on a photosensitive drum, in which a primary transfer roller transfers the toner image formed on the photosensitive drum by the discharge execution section by applying, to a predetermined area part of the toner image, a first transfer bias having a predetermined transfer efficiency with respect to an intermediate transfer belt and applying, to a part excluding the predetermined area part of the toner image, a second transfer bias whose transfer efficiency is at least smaller than the predetermined transfer efficiency of the first transfer bias.

Abstract: An image forming apparatus includes movable first and second image bearing members, latent image forming units that form electrostatic latent images and latent index patterns, a movable belt member contacting the image bearing members, toner image transfer members that transfer toner images, obtained by depositing toner on the latent images, onto the belt member, latent pattern detectors that detect the latent index patterns, an adjusting portion that adjusts relative positions between the latent index patterns on the basis of detection results of the detectors, and a setting portion that sets a latent pattern transfer voltage, during image formation, on the basis of a detection result of one of the latent pattern detectors on condition that a plurality of test voltages are applied to one of the latent pattern transfer member during non-image formation.

Abstract: A control unit is provided which controls at least one of a first power supply unit (a secondary transfer power supply connected to a secondary transfer roller) and a second power supply unit (high-voltage power supplies connected to a conductive brush and a conductive roller) so that a current supplied to a primary transfer region from a beginning of primary transfer until a beginning of secondary transfer has a magnitude larger than a magnitude of a current supplied to the primary transfer region from a beginning of image formation until the beginning of the primary transfer.

Abstract: An image forming apparatus includes a first forming unit that forms a color image on a first image-carrier using a color toner, a first transfer unit that transfers the color image formed on the first image-carrier to a transfer medium at a first transfer bias, a second forming unit that, using an invisible toner absorbing infrared light or ultraviolet light, forms on a second image-carrier a code image representing information by an arrangement of dots, and a second transfer unit that transfers the code image formed on the second image-carrier to the transfer medium at a second transfer bias higher than the first transfer bias.

Abstract: An image forming apparatus capable of accurately forming an image in a predetermined position on a sheet. An image forming unit forms a toner image on a drum. The toner image is transferred onto a belt. A motor drives the belt to convey the toner image to a transfer position where the toner image is transferred onto a sheet. An image position-detecting section detects that a patch image indicating the position of the toner image on the belt has reached a detection position upstream of the transfer position in an image conveying direction. A sheet position-detecting section detects that the leading edge of the sheet has reached a detection position upstream of the transfer position in a sheet conveying direction. An image speed-setting section controls the conveying speed of the belt based on timings of detection by the respective image position-detecting and sheet position-detecting sections.

Abstract: An image forming method includes rotating a transfer roller which forms a transfer nip by coming in contact with a transfer belt and has a concaved portion wider than the transfer nip in a rotation direction, such that the concaved portion comes to a position of facing the transfer belt, stopping rotation of the transfer roller at a position where the transfer belt faces the concaved portion of the transfer roller and the transfer belt and the transfer roller are spaced apart from each other, moving the transfer belt while the transfer roller is stopped and transferring an image formed on an image carrier to the transfer belt, and detecting the transferred image by a detection portion.

Abstract: A transfer device includes a transfer device, a facing member, and a prepressing member. The transfer member transfers a toner image, which is carried on an intermediate transfer member, to a recording medium. The facing member is disposed so as to be in pressed contact with the transfer member with the intermediate transfer member therebetween. The prepressing member is disposed so as to be in pressed contact with the transfer member with the intermediate transfer member therebetween at a position that is upstream of a contact section in which the facing member is in pressed contact with the transfer member and that is immediately behind a position at which the toner image starts to come into contact with the recording medium. A pressure applied by the prepressing member is lower than a pressure with which the facing member is in pressed contact with the transfer member.

Abstract: An image forming apparatus including: an intermediate transfer member configured to transfer the developer images on the plurality of photosensitive members; a secondary transfer member configured to transfer the developer images transferred onto the intermediate transfer member onto a recording sheet; a plurality of primary holding rollers provided to each of the plurality of photosensitive members, respectively; a collecting unit configured to collect developer remaining on the intermediate transfer member; and a control device configured to control biases applied to the secondary transfer member and the plurality of primary holding rollers, wherein, after printing control terminates, the control device is configured to perform cleaning control in which biases having opposite polarities to biases during the printing control are applied to the plurality of primary holding rollers and the secondary transfer member.

Abstract: An image forming apparatus includes an image carrier, a transfer member and a cleaning member. The image forming apparatus: determines whether the electric resistance of a recording medium is low or high; applies a first transfer bias to the transfer member if the electric resistance is low; applies a second transfer bias to the transfer member if the electric resistance is high; applies a first cleaning bias to the cleaning member if the electric resistance is low; and applies a second cleaning bias to the cleaning member so that a potential difference between a portion of a surface of the image carrier against which the cleaning member is rubbed and the cleaning member becomes smaller than that in a case of applying the first cleaning bias if the electric resistance is high.

Abstract: A detection unit is disposed between a feeding unit and a secondary transfer unit on a conveyance path, and detects a transfer material that is conveyed. A control unit, if the detection unit cannot detect the transfer material by a predetermined timing after a feeding operation by a feeding unit, moves the secondary transfer unit away from a intermediate transfer member, causes the intermediate transfer member to continue rotating, and causes the feeding unit to retry feeding of the transfer material.

Abstract: A transfer unit includes a rotatable static-dissipative member with a time-varying electrical property. A second member selectively transfers toner to or from the static-dissipative member. A power source selectively produces an electrostatic transfer field between the static-dissipative member and the second member, so that toner is transferred between the static-dissipative member and the second member. A charger spaced apart from the static-dissipative member selectively deposits charge thereon. A control system successively drives a plurality of different selected voltages or currents through the charger and measures a plurality of respective resulting charger currents or voltages. It uses the selected voltages or currents and the respective charger currents or voltages to automatically estimate a variation in the electrical property. It then causes the power source to produce an electric transfer field that transfers toner and compensates for the estimated variation.

Abstract: An image forming apparatus includes an image forming unit, an image carrier carrying a developer image, a transfer unit for transferring the developer image to a recording medium, a voltage supplying unit for supplying a transfer voltage to the transfer unit, a transfer current measuring unit for measuring a transfer current value when a prescribed voltage is applied while no recording medium exists in the transfer unit, a resistor serially coupled between the transfer current measuring unit and the transfer unit, a memory unit for memorizing electrical character information of the recording medium, and a controller for controlling the transfer voltage where the developer is transferred to the recording medium, based on a consequence measured by the transfer current measuring unit, a recording medium width in association with the recording medium type, the electrical character information, and a resistance value of the resistor, to adjust a secondary transfer current value.

Abstract: An image forming apparatus includes an image carrier, a transfer unit, and a control unit. The image carrier has a surface to bear a toner image thereon. The transfer unit has a transfer member to transfer the toner image onto a recording sheet conveyed in a conveyance direction for trailing-end borderless image formation and duplex image formation. The transfer unit is configured to form the toner image on the recording sheet without forming a margin at a trailing end of the recording sheet in the conveyance sheet in the trailing-end borderless image formation. The transfer unit is configured to form the toner image on front and back faces of the recording sheet in the duplex image formation. When a width of the toner image formed in a borderless image area of the recording sheet in the trailing-end borderless image formation is smaller in a direction perpendicular to the conveyance direction than a threshold value, the control unit permits the duplex image formation.

Abstract: An image transfer system comprises an image bearer and an opposed member having a contact surface contacting a recording medium and opposed to a surface of the image bearer to form a transfer nip. A pressing device applies pressure to the transfer nip. An engaging and disengaging member engages and disengages the contact surface from the surface of the image bearer. A transfer bias device applies a transfer bias transferring an image formed on the image bearer onto the recording medium conveyed and pinched at the transfer nip. The image is composed of an adjustment pattern formed on a portion of the image bearer corresponding to an interval between recording mediums successively conveyed through the transfer nip. The engaging and disengaging device disengages the contact surface from the surface of the image bearer to form a gap therebetween when the adjustment pattern passes therethrough.

Abstract: An image forming apparatus has an intermediate transfer member to which an image on an image bearing member is primarily transferred. The image primarily transferred to the intermediate transfer member is secondarily transferred to a recording medium. The velocity at which the recording medium is conveyed is switched to a velocity different from the image forming velocity before the recording medium is conveyed to the transfer position.

Abstract: An image forming apparatus includes a bias controller that controls a first application unit that applies a bias to a transfer member. The bias controller applies a reverse bias to the transfer member when a first region passes through a nip part. Then, when a second region passes through the nip part, the bias controller applies a fixed first forward bias to the transfer member. When a third region passes through the nip part, in order to implement the control the bias controller applies a variable second forward bias to the transfer member. The first forward bias is set at a predetermined value or above and increases a potential of the transfer member 46 to a level at which a toner image is transferred in the second region when the second region passes through the nip part.

Abstract: A transfer device includes a power supply control unit, a direct-current (DC) power supply, an alternating-current (AC) power supply, and a transfer unit. The power supply control unit controls a first control signal for controlling a DC voltage and a second control signal for controlling an AC voltage based on a condition relating to image formation. The DC power supply outputs the DC voltage based on the first control signal. The AC power supply selectively outputs, with a particular waveform, either of the DC voltage output from the DC power supply or a superimposed voltage obtained by superimposing the AC voltage determined based on the second control signal on the DC voltage output from the DC power supply. The transfer unit transfers a developer onto a sheet using a voltage output from the AC power supply.

Abstract: An image forming apparatus includes: an image carrier; a toner image forming unit that forms a toner image on the image carrier; a transfer unit that transfers the toner image on the image carrier to a transfer target having ridges and valleys on a surface thereof; an adjusting unit that adjusts a ratio of A/B, where A is a transfer ratio [%] from the image carrier to a valley portion of the transfer target while B is a transfer ratio [%] from the image carrier to a ridge portion of the transfer target, based on an adjustment input by a user; and a control unit that controls a transfer condition of the transfer unit based on the ratio of A/B adjusted by the adjusting unit.

Abstract: A transfer device comprising: a load including a transferring unit, the transferring unit being configured to transfer an image on a transferable material; a direct current source connected to the load and configured to apply a direct voltage to the load; and an alternating current source connected between the load and the direct current source in attachable and detachable manner, the alternating current source being configured to selectively apply to the load an overlapping voltage that is formed by overlapping an alternating voltage and the direct voltage.

Abstract: An image forming apparatus includes a power source to output a voltage having an alternating waveform to transfer a toner image from an image bearing member to a recording medium. A time-averaged value (Vave) of the voltage has a polarity in a transfer direction, in which the toner image is transferred from the image bearing member to the recording medium, and an absolute value of the time-averaged value is greater than a midpoint value (Voff) of the voltage intermediate between a maximum value and a minimum value of the voltage. As a roughness of the recording medium increases, a duty ratio (Duty) expressed by A/(A+B) is reduced, where A is an area of the waveform of the voltage in a return direction opposite the transfer direction relative to the midpoint value in one cycle and B is an area in the transfer direction relative to the midpoint value.

Abstract: An image forming apparatus includes: a conveying belt; a first photosensitive member; and a second photosensitive member; a first transfer member; a second transfer member; a first pushing member; a second pushing member; and a changing unit, wherein the first photosensitive member is disposed on the upstream side of the second photosensitive member in a conveying direction of the transfer receiving member, and the changing unit changes the pushing force of the second transfer member that is disposed on the downstream side of the first photosensitive member in a conveying direction of the transfer receiving member.

Abstract: A multifunction peripheral includes: development units of respective colors; an intermediate transfer belt; a transfer roller; a movement mechanism that moves the intermediate transfer belt in a direction of coming in contact with and separating from a magenta development unit and the like; a concentration sensor; a control part that causes the magenta development unit and the transfer roller to form a toner pattern on the intermediate transfer belt; and a determination unit that determines that the pressing state of the magenta development unit and the like and the intermediate transfer belt is normal when the toner pattern concentration detected by the concentration sensor after the toner pattern is transferred to the intermediate transfer belt has reached a predetermined concentration value.

Abstract: Apparatus and method for minimizing ghosting defects and process control instabilities for a printing system are disclosed. According to an exemplary embodiment, a controller retrieves uniformity measurements of an interdocument zone (IDZ) and sheet zone (SZ). In response to the uniformity measurements, a transfer current IDZ level is controlled to minimize differences in subsequent charging, photodischarge and/or development associated with the IDZ and SZ.

Abstract: The image forming apparatus has a first and a second transfer member which transfer toner images onto a transfer body; and a control section, which measures a first density of a first toner image formed on the transfer body, measures a second density of a second toner image formed on the transfer body and determines a transfer current for the first and the second transfer member based on the first and the second density.

Abstract: An image forming apparatus has an image forming section having a photoreceptor on which a toner image is formed, an endless belt that revolves with its outer surface facing the photoreceptor, a steering roller adapted to provide a tension to the belt and adjust the position of the belt in the width direction, a transfer roller that presses the belt toward the photoreceptor so as to form a transfer nip where the toner image is transferred, a transfer pressure adjusting mechanism adapted to adjust pressing force when the transfer roller presses the belt toward the photoreceptor, and a controller adapted to control the pressing force adjusted by the transfer pressure adjusting mechanism, according to the adjustment state of the steering roller.

Abstract: A transfer bias voltage supplier supplies, to a transfer member, a transfer bias voltage of a polarity opposite to the polarity of toner. The absolute value of transfer bias voltage to be supplied to the transfer member when a leading/trailing end of the sheet is passed through the nip portion is set smaller than when a toner image transfer region of the sheet is passed through the nip portion. A separation bias voltage supplier supplies, to a discharging electrode member, a separation bias voltage of a polarity opposite to the polarity of transfer bias voltage. The absolute value of separation bias voltage to be supplied to the discharging electrode member when the leading/trailing end of the sheet is passed through a discharging gap is set smaller than when the transfer region is passed through the discharging gap.

Abstract: An image forming apparatus is provided. The image forming apparatus includes a chassis having an opening, a cover, photosensitive members, an intermediate transfer belt, a primary-transfer member, a secondary-transfer roller, a cleaner device, a waste toner container, which is movable along a predetermined direction to be removably installed in the chassis through the opening and stores residual toner, a connector, and a feed roller, which is arranged within the feeding path to feed the recording sheet in the feeding path. The feed roller is arranged in a position to at least partially fall within a vertical range of the waste toner container and to be aligned with the waste toner container along an axial direction of the second feed roller.

Abstract: The image forming apparatus includes a discharge execution section for forcedly discharging toner from a developing device and forming a toner image on a photosensitive drum, in which a primary transfer roller transfers the toner image formed on the photosensitive drum by the discharge execution section by applying, to a predetermined area part of the toner image, a first transfer bias having a predetermined transfer efficiency with respect to an intermediate transfer belt and applying, to a part excluding the predetermined area part of the toner image, a second transfer bias whose transfer efficiency is at least smaller than the predetermined transfer efficiency of the first transfer bias.

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 bearing member, a transfer member, and a power supply unit that outputs a voltage to the transfer member. The power supply unit includes a first voltage generation circuit that includes a piezoelectric transformer driven at a drive frequency within a predetermined frequency area to output a first voltage having a predetermined polarity, and a second voltage generation circuit that outputs a second voltage with a polarity opposite to the predetermined polarity. In addition, a control unit controls the power supply unit to output a superposed voltage as a voltage having the predetermined polarity and corresponding to a voltage output from the piezoelectric transformer by driving the piezoelectric transformer at a driven frequency out of range of the predetermined frequency area, with the superposed voltage being a voltage in which the first voltage and the second voltage are superposed.

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 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 an intermediary transfer member having an elastic layer; a toner image forming portion for forming a toner image for an image to be carried on the intermediary transfer member; a transfer member, which presses the intermediary transfer member, for transferring the toner image for the image from the intermediary transfer member onto a recording material; a pressing mechanism capable of changing pressure applied from the transfer member to the intermediary transfer member; and a controller for controlling the toner image forming portion so that a length of the toner image for the image on the intermediary transfer member with respect to a rotational direction of the intermediary transfer member is decreased with an increase of the pressure.

Abstract: An image forming apparatus includes an image bearing member for bearing a toner image, a rotatable intermediary transfer member onto which the toner image is to be primary-transferred from the image bearing member, a contact member movable toward and away from the intermediary transfer member, a voltage applying unit for applying a voltage to the contact member, a current detecting circuit for detecting a current passing through the contact member, and a control portion for effecting control so that the contact member is in contact with or separated from the intermediary transfer member.

Abstract: In an image forming apparatus transferring a toner image on an intermediate transfer member onto a sheet in a transfer nip between a nip forming member and the transfer member, a resistance or environment detection device detects electrical resistance of the sheet or an environmental parameter correlated with the resistance, an output device outputs a transfer current, a storage device stores, as an algorithm for calculating a transfer current target value according to an image area ratio in the nip, algorithms corresponding to different resistances or environmental parameters, and a control device selects and uses, from the algorithms, an algorithm according to the detection result of the resistance or environment detection device as the algorithm for calculating the target value, and controls an output current value to equalize a current value based on the image area ratio in the nip with the target value based on the algorithm.

Abstract: An image forming apparatus includes an image bearing member bearing a toner image, an endless rotatable transfer belt for transferring the toner image from the image bearing member to a transfer material, and a transfer device transferring the toner image from the image bearing member to the transfer belt. The transfer device includes a sheet member, one end of which is fixed and the other end of which comes in contact with an inner peripheral surface of the transfer belt, and a pressing member for pressing the sheet member to the transfer belt. In addition, a moving unit moves the pressing member in a moving direction of the transfer belt so that a contact state of the sheet member with respect to the transfer belt is changed.

Abstract: An image forming apparatus includes: an image carrier; a transfer member arranged so as to face the image carrier; and a non-transferred toner adhesion unit that causes a non-transferred toner to adhere to an inter-sheet area present on the image carrier during a period of continuous image formation in which images are continuously formed on the image carrier. The transfer member is a foam roller. The image forming apparatus further includes a contacting and separating unit that causes the foam roller and the image carrier to come into contact with and be separated from each other. The contacting and separating unit separates the image carrier and the transfer member when the inter-sheet area present on the image carrier passes through a transfer area in which the image carrier and the transfer member face each other in association with rotation of the image carrier.

Abstract: An image forming apparatus including: a transfer belt; a rotational body; a transfer roller that forms a transfer nip part between the transfer roller and the rotational body with the transfer belt therebetween; a pressing section that presses one of the rotational body and the transfer roller against the other of the rotational body and the transfer roller; and a controlling section that controls the pressing section so as to change the pressing direction of the rotational body or the transfer roller in accordance with a predetermined image formation condition.

Abstract: An image forming apparatus includes an image carrier, a charging unit, an exposure unit, a developing unit, and a transfer unit. The transfer unit includes a bias power supply and transfers a developed image onto a transfer body. The bias power supply includes a first power supply unit, a second power supply unit, a threshold setting unit, a detector, and an output controller. The first power supply unit generates a transfer electric field. The second power supply unit generates a non-transfer electric field. The threshold setting unit has a first threshold and a second threshold, and performs a change from the first threshold to the second threshold when switching from the non-transfer electric field to the transfer electric field is performed. The detector detects the current which is caused to flow by the first power supply unit. The output controller controls the first power supply unit.

Abstract: An image forming apparatus includes a transfer member configured to abut against an image carrier for carrying a toner image to form a transfer nip; and a power supply configured to output a bias voltage for transferring the toner image on the image carrier onto a recording medium nipped in the transfer nip. The bias voltage includes a first voltage for transferring the toner image from the image carrier onto the recording medium in a transfer direction and a second voltage having an opposite polarity of the first voltage, the first and the second voltages being alternately output. A time-averaged value of the bias voltage is set to a polarity in the transfer direction and is set in the transfer direction side with respect to a median between a maximum and a minimum of the bias voltage.