Abstract: An image forming apparatus includes an image forming unit, a fixer, first and second temperature sensors, and storage and control units. The fixer fixes an image formed on the sheet by pressing. The first temperature sensor is disposed away from the image forming unit and the fixer, and measures an ambient temperature. The second temperature sensor is disposed closer to the image forming unit than the first temperature sensor, and measures an ambient temperature. The storage unit stores one or more difference values between first and second temperatures measured by the first and second temperature sensors when a switching condition is satisfied. When a difference between the one or more difference values in the storage unit and a latest difference value is equal to or larger than a threshold, the control unit stores information indicating that a reference value for determining an abnormality is exceeded.

Abstract: In an image forming apparatus including a transfer member that primarily transfers a developer image from an image bearing member onto an intermediate transfer belt by applying an electric current to an intermediate transfer belt in a circumferential direction, a control unit which executes a first mode in which to rotate the intermediate transfer belt and a second mode in which to rotate the intermediate transfer belt at a rotation speed higher than that in the first mode. The control unit performs control such that an absolute value of a second voltage to be applied to the transfer member in a case of performing primary transfer in the second mode is less than an absolute value of a first voltage to be applied to the transfer member in a case of performing the primary transfer in the first mode.

Abstract: An electrophotographic belt includes a biaxially stretched cylindrical film as a base layer, wherein the biaxially stretched cylindrical film includes crystalline polyester, amorphous polyester and carbon black, a content of the carbon black with respect to the biaxially stretched cylindrical film is 2.0% by mass or more, and a surface resistivity measured on the surface of the biaxially stretched cylindrical film in an environment of 23° C. and 50% RH is 1×103 ?/square or higher and 1×1013 ?/square or lower, and A/B is 3.00 or smaller, where A (?/square) represents a surface resistivity of the biaxially stretched cylindrical film after the film is left to stand for 24 hours in an environment of 23° C. and 50% RH, and B (?/square) represents a surface resistivity of the biaxially stretched cylindrical film after the film is left to stand for 24 hours in an environment of 30° C. and 80% RH.

Abstract: An image forming apparatus includes an image bearing member, an image forming portion, a transfer member, an applying portion, and an executing portion configured to execute an output operation for forming and outputting a chart formed on a recording material on which a plurality of test images are transferred by applying a plurality of voltages to the transfer member by the applying portion. The executing portion changes a change width per level of the test voltage so that the change width is a first change width in a case that a material of the recording material on which the chart is formed is a first material and so that the change width is a second change width different from the first change width in a case that the material of the recording material is a second material different from the first material.

Abstract: An image forming apparatus includes an image bearing member, an image forming portion, a transfer member, a power source, an acquiring portion, and a controller capable of executing an operation in an adjustment mode. A plurality of test toner images transferred onto a recording material in the occurrence in the adjusting mode include a first test toner image transferred under application of a first test voltage and a second test toner image transferred under application of a second test voltage different from the first test voltage. In the operation in the adjustment mode, the controller adjusts the transfer voltage set for transfer on the basis of first information on variation in image density acquired in different regions of the first test toner image and second information on variation in image density acquired in different regions of the second test toner image.

Abstract: An image forming apparatus includes a sensing portion configured to sense a current that flows through a secondary transfer member, or a voltage that has been applied; and a controller configured to perform an operation to determine a transfer voltage to be applied to the secondary transfer member in secondary transfer, on a basis of a result of sensing performed by the sensing portion at a time when a test voltage has been applied to the secondary transfer member in non-image formation, and the controller performs, in the operation, controlling a first application portion and a second application portion not to apply the voltage to a primary transfer member during a period of applying the test voltage to the secondary transfer member.

Abstract: An image forming method includes forming, fixing, and applying. The forming forms a toner image on a recording medium by an image forming device. The fixing fixes the toner image on the recording medium with heat by a fixing device. The applying applies an electric charge by a charge applying device to the recording medium on which the toner image has been fixed by the fixing device, in a state in which an output-adjustable power source for the charge applying device has an electric current that is controlled to be constant.

Abstract: A measurement device is provided with: a measurement unit including a first mode that measures an electrical resistance of a recording medium used in an image forming apparatus in a first predetermined range of electrical resistance values and a second mode that measures the electrical resistance in a second range of electrical resistance values different from the first range, the second range and the first range being set such that with respect to the electrical resistance of multiple brands of recording media, a number of brands belonging to the second range is greater than a number of brands belonging to the first range; and a control unit that controls the measurement unit to prioritize execution of the second mode over the first mode.

Abstract: A transfer unit includes, as transfer rollers, a first roller and a second roller of which the latter has an elastic layer larger in an axial direction than that of the former, a first bearing member, a second bearing member, a roller holder, a first urging member, a second urging member, a switching cam, a transfer voltage power supply, and a driving mechanism. By rotating the roller holder, one of the first and second rollers is arranged opposite an image carrying member and, by rotating the switching cam, the first or second roller arranged opposite the image carrying member is arranged either at a reference position at which, by being kept in pressed contact with the image carrying member, the first or second roller forms a transfer nip or at a released position at which the first or second roller lies away from the image carrying member.

Abstract: The control unit executes a mode of detecting the image density of the toner image for control. The control unit sets the target toner density so that the target toner density becomes smaller than before execution of the mode and also set the target transfer current so that the target transfer current becomes smaller, in a case where the image density detected in the mode is higher by a predetermined threshold or more than a reference density.

Abstract: An image forming apparatus includes an image bearing member, a transfer member, a voltage applying portion applying a voltage to the transfer member, and a controller. The controller starts a control operation by applying a control voltage to the transfer member before a toner image is transferred to a transferred member from the image bearing member. On the basis of a coverage ratio indicating a ratio occupied by an image region per predetermined area regarding the toner image transferred to the transferred member from the image bearing member, the controller determines execution or non-execution of the control operation capable of being started before the toner image is transferred to the transferred member.

Abstract: A transfer unit includes a first roller, a second roller, a first bearing member, a second bearing member, a roller holder, a first urging member, a second urging member, a first switching cam, a second switching cam, and a driving mechanism. The first and second switching cams have first and second guide holes with which first and second engaging portions formed on the first and second bearing members engage respectively. By rotating the roller holder, one of the first and second rollers is arranged opposite an image carrying member and, by rotating the first and second switching cams to change engaging positions of the first and second engaging portions respectively, the first or second roller is arranged either at a reference position at which it is kept in pressed contact with the image carrying member or at a released position.

Abstract: A transfer unit includes first and second rollers of which the second roller has an elastic layer larger in the axial direction than the first roller, a roller holder, and a switching cam. One of the first and second rollers is, by rotating the roller holder, arranged opposite an image carrying member and, by rotating the switching cam, arranged selectively either at a reference position to form a transfer nip or at a released position to lie away from the image carrying member. Let a length of the elastic layer of the first roller in the axial direction, a width of an effective image area on the image carrying member to which a toner image can be transferred, and a width of a recording medium of a maximum size allowing transfer using the first roller be L1, L3, and L4 respectively, L4<L1?L3?5 mm is fulfilled.

Abstract: An image forming apparatus includes a controller and a transfer power supply portion configured to output a transfer voltage to a transfer portion so as to transfer a toner image onto a recording material. The transfer power supply portion superimposes a voltage output from a first power supply portion and a voltage output from a second power supply portion to output a superimposed voltage to the transfer portion. The first power supply portion includes a transformer including a primary coil and a secondary coil, and a rectifier circuit portion. The rectifier circuit portion includes a plurality of diodes and a plurality of capacitors. A capacitance of a predetermined capacitor to be charged by a half-wave rectified voltage of an AC voltage generated in the secondary coil is larger than a capacitance of a capacitor to be charged by a voltage higher than the half-wave rectified voltage.

Abstract: In an image forming apparatus, a cleaning blade, disposed on a downstream side of a transfer roller in a rotation direction of an image carrier, removes toner remaining on the image carrier after transfer of a toner image to an intermediate transfer member. After completion of an image forming operation, a controller causes the transfer roller to separate from the intermediate transfer member, cause the developing device to form on the image carrier a toner band to be supplied to the cleaning blade, and cause rotation of the image carrier to stop such that at least a part of the toner band formed on the image carrier stops within a section from a first position facing the transfer roller to a second position facing the cleaning blade in the rotation direction.

Abstract: An image forming apparatus includes an image forming portion, an image input portion, a transfer unit, a transfer voltage power supply, and a control portion. The transfer unit includes a transfer roller having a metal shaft and an elastic layer laid around an outer circumferential face of the metal shaft to form a transfer nip by keeping the elastic layer in pressed contact with an image carrying member, and transfers a toner image formed on the image carrying member to a recording medium as it passes through the transfer nip. The transfer unit includes, as the transfer roller, a first roller, and a second roller having a larger axial-size elastic layer compared to the first roller. The control portion arranges the first or second roller opposite the image carrying member according to width-direction sizes of the recording medium and image data fed to the image input portion.

Abstract: A belt transfer type multi-function device includes: a control device performing controlling such that an image to be printed on paper already caught between a transfer roller and the belt roller is printed, and if printing should not be performed on a next paper, movement of the next paper is stopped on a transfer path before the next paper is positioned between the transfer roller and the belt roller, the image already transferred on the transfer belt is deleted in a state in which the next paper is stopped on the transfer path, and the next paper in a stopped state is ejected as a blank paper through a ejection port along the transfer path, so that the image already transferred to the transfer belt, which is to be printed on the next paper along the movement direction of paper, is not printed on the next paper.

Abstract: An imaging system includes a transfer roller, a bias application device, and a controller. The transfer roller forms a transfer nip region between the transfer roller and a transfer belt, and the transfer roller transfers toner images carried on the transfer belt, onto media conveyed through the transfer nip region, during a print job. The bias application device applies a bias to the transfer roller. The controller controls the bias application device to apply a first bias to the transfer roller so that the toner image is transferred to a first medium during the printing job, apply a second bias having a polarity opposite to the first bias to the transfer roller between the first medium and a second medium following the first medium, and apply a third bias having the same polarity as the first bias to the transfer roller between the first medium and the second medium.

Abstract: An image forming apparatus includes image bearing members, an intermediary transfer member having ion conductivity, primary transfer members, a first voltage applying portion, a secondary transfer member, a second voltage applying portion, and a controller. On the basis of image information, the controller controls a transfer voltage applied to the secondary transfer member so as to be different between a first voltage when a first region, in which a coverage indicating a ratio occupied by an image region per predetermined area is a first coverage passes through the secondary transfer portion and a second voltage when a second region, in which the coverage is a second coverage larger than the first coverage, passes through the secondary transfer portion. The controller controls a change amount of the first voltage with respect to the second voltage so as to be different between a first mode and a second mode.

Abstract: An example image forming apparatus includes a printing engine including a plurality of photosensitive drums, a motor device to provide a driving force to each of the plurality of photosensitive drums, and a processor to control the printing engine such that printing data is printed on a printing paper and control the motor device such that at least one of the plurality of photosensitive drums operates at a different speed from the other photosensitive drums while the printing data is printed.

Abstract: An imaging system includes an endless belt, a tensioning system that applies tension to the endless belt, a contact member that engages with the endless belt, and a detector that detects slack at a part of the endless belt. A controller causes the contact member to be separated from the endless belt so that the tensioning system reduces the slack of the endless belt in response to the detector detecting the slack.

Abstract: An image forming apparatus includes an image forming portion, a belt, an inner roller, an outer member, an inner roller position changing mechanism, an acquiring portion, and a controller. In a case that information acquired by the acquiring portion shows that first and second recording materials are coated paper, the controller controls a position changing mechanism so that a position of the inner roller when a toner image is transferred onto the second recording material is changed to a second position. In a case that the information acquired by the acquiring portion shows that the first and second recording materials are plain paper, the controller controls the position changing mechanism so that the position of the inner roller when the toner image is transferred onto the second recording material is maintained at a first position.

Abstract: An electrophotographic printer includes a charge roller in charge-transferring relation to a photoconductive imaging portion. The printer may determine an AC voltage setpoint of the charge roller.

Abstract: An image forming apparatus includes an image bearing member; a transfer member configured to transfer a toner image carried on the image bearing member to a sheet by being applied with a voltage; a controller configured to execute a mode of outputting a test chart for setting a voltage to be applied to the transfer member during image formation, the mode being a mode of transferring a plurality of test images to the test chart by applying a plurality of different voltages to the transfer member; and an operation portion capable of setting a type of a sheet on which the mode is executed. The controller is configured to preset a voltage value for setting a voltage to be applied when the test images are transferred in execution of the mode based on a voltage value, which is set in the previous execution of the mode.

Abstract: An image formation apparatus according to an embodiment may include: a first image formation unit that forms a first toner image on a first image carrier by using a bright toner containing a bright pigment; a second image formation unit that forms a second toner image on a second image carrier by using a non-bright toner containing no bright pigment; a transfer unit that transfers the first and second toner images to a transfer body; and a controller that controls the transfer unit. The controller is configured to perform control such that a transfer efficiency of the bright toner in a case where the second toner image is superimposed to the first toner image formed on the transfer body is lower than the transfer efficiency of the bright toner in a case where the second toner image is not superimposed to the first toner image formed on the transfer body.

Abstract: An image forming apparatus includes an image bearing member, an intermediary transfer belt, a transfer member, a voltage source for applying a voltage to the transfer member, a detecting portion for detecting a current flowing through the transfer member, and a controller for carrying out constant-voltage control so that the voltage applied to the transfer member becomes a target voltage when a recording material P passes through a transfer portion. The controller is capable of changing the voltage applied to the transfer member so that a detection result detected by the detecting portion during transfer falls within a predetermined range. The controller changes the predetermined range on the basis of the detection result detected by the detecting portion when the voltage is applied to the transfer member in a state in which the recording material P is absent in the transfer portion.

Abstract: An imaging system includes a steering roller and a positioning mechanism. The steering roller extends along a longitudinal direction, and being tiltable about a fulcrum to adjust an alignment position of an endless belt. The positioning mechanism is coupled to the steering roller, to position an adjustable position of the fulcrum of the steering roller, along the longitudinal direction of the steering roller. The positioning mechanism includes a guide that extends along the longitudinal direction of the steering roller, and a protrusion that engages with the guide, and that is located at the adjustable position of the fulcrum.

Abstract: An image forming apparatus includes a transferred body to which a toner image is transferred, a transfer device, a contact-separation device, and circuitry. The transfer device transfers the toner image from the transferred body onto a recording medium. The contact-separation device includes a motor and drives the motor to move the transfer device away from or into contact with the transferred body. The circuitry causes the contact-separation device to move the transfer device away from or into contact with the transferred body. The circuitry moves the transfer device away from the transferred body to a first position during standby and locates the transfer device at a second position that is closer to a contact position at which the transfer device is configured to contact the transferred body than the first position in an interval between the recording medium and a succeeding recording medium.

Abstract: Provided is an image forming apparatus including an image carrier, a transfer unit, a driver, a hardware processor, an adjustment mechanism, and a speed detector. The hardware processor sets a command value. The hardware processor performs a constant-torque control based on a constant-speed drive torque detected in a constant-speed control. In the constant-torque control, the hardware processor performs a feedback control to set a reference value to an average speed of the driver during passage of a first sheet and calculate a difference from an average speed during passage of a subsequent sheet so as to derive the command value. The hardware processor determines whether a load torque increase, its factor, and/or its influence exceeds a threshold, and forcibly sets the reference value to a speed detected while a pressure between the transfer unit and the image carrier is reduced by the adjustment mechanism from the pressure during image transfer.

Abstract: An image forming apparatus includes a plurality of paper feed portions, an image forming portion, a storage portion that stores, for each of the paper feed portions, sheet delay information indicating an occurrence frequency of a sheet delay that is a phenomenon in which a time required for arrival of a front end of the sheet at a prescribed position from the start of feeding of the sheet is larger than a threshold time, and a control portion that, based on the sheet delay information on the each of the paper feed portions, recognizes the occurrence frequency of a sheet delay of each of the plurality of paper feed portions and preferentially sets, as a paper feed source, one of the paper feed portions whose value of the occurrence frequency of a sheet delay is equal to or less than a prescribed value.

Abstract: An image forming apparatus includes a photosensitive member, a transfer member, a transfer power source, and a control unit. At a start time of a start-up operation at the time of starting an image forming operation, on the surface of the photosensitive member, a first position coincides with a charging position, and a third position coincides with a transfer position. During a period in which an area on the photosensitive member located between the first position and the third position in a rotation direction of the photosensitive member passes the transfer position, the control unit performs control of applying a first voltage having the same polarity as a normal charging polarity of toner to the transfer member by the transfer power source, and, at a predetermined timing, changing a voltage from the first voltage to a second voltage having an absolute value less than that of the first voltage.

Abstract: An image forming apparatus includes an image bearing member; a transfer member; and a controller configured to execute a plurality of modes of outputting a test chart, the modes involving transferring a plurality of test images to the test chart by applying a plurality of different voltages to the transfer member. The modes include a first mode and a second mode, the first mode being a mode in which a number of voltage levels to be applied to the transfer member when the plurality of test images are transferred to the test chart is a first predetermined number, and the second mode being a mode in which the number of voltage levels to be applied to the transfer member when the plurality of test images are transferred to the test chart is a second predetermined number which is greater than the first predetermined number.

Abstract: An image forming apparatus includes an intermediate transfer belt, a plurality of rollers including an inner roller and where the intermediate transfer belt is stretched, an outer roller provided at a position facing the inner roller with the intermediate transfer belt in between, and an arm member. The intermediate transfer belt receives transfer of a toner image. The outer roller forms a transfer nip to transfer the toner image from the intermediate transfer belt to a recording medium. The arm member rotatably supports both end parts of the inner roller. When the inner roller is positioned at a first rotating position, the transfer nip is formed at a first position in an outer roller circumferential direction, and when the inner roller is positioned at a second rotating position, the transfer nip is formed at a second position different from the first transfer nip position in the outer roller circumferential direction.

Abstract: An image forming apparatus includes an image bearing member, a transfer member, a voltage source, a current detecting portion, and a controller. In a case that the predetermined voltage is changed in a first job on the basis of the detection result of the current detecting portion during passing of the recording material through the transfer portion, in a second job subsequent to the first job, when a first recording material of the second job passes through the transfer portion, the controller changes a voltage applied to the transfer member on the basis of the predetermined voltage changed in the first job.

Abstract: A controller can select and execute a full color mode of performing image formation in a first state in which each primary transfer member is in contact with an intermediate transfer belt, and a monochrome mode of performing image formation in a second state in which only a primary transfer member is in contact with the intermediate transfer belt. The controller determines which state of the first state and the second state is formed, based on a detection result obtained by a current detection circuit when a photosensitive drum is charged by a charging roller, and voltage is applied to the primary transfer member from a primary transfer power source.

Abstract: In a state that a first voltage is applied to a charging member so as to form a surface potential on a region of an image bearing member and a second voltage the same in polarity as the first voltage is applied to a transfer member, a detection unit detects a transfer current in the region of the image bearing member during one rotation of the image hearing member after the region passes through a charging portion, when an absolute value of the surface potential formed on the region immediately before entry into the charging portion is larger than an absolute value of the surface potential formed on the region when it is positioned upstream of a transfer portion and downstream of the charging portion in a rotational direction of the image bearing member.

Abstract: An image forming apparatus includes a detection member configured to detect a conveyance state of a recording medium, a control unit configured to sequentially execute a first operation for continuously executing a rotation operation of an image bearing member and an intermediate transfer member without stopping them when the detection member detects a failure, and a second operation for stopping the rotation operation of the image bearing member when the surface of the image bearing member is moved by a predetermined distance through the rotation operation of the image bearing member after the failure is detected.

Abstract: An image forming apparatus comprises a plurality of sheet detection units, provided at different positions along a sheet width direction, configured to detect the sheet conveyed on a conveyance path. A controller determines, by using the plurality of sheet detection units, a presence or absence of a sheet being conveyed in each of a plurality of regions sectioned in the sheet width direction, and determines, based on input image data, a presence or absence of an image to be formed in each of the plurality of regions. The controller further determines, based on the above determination results, whether or not the image to be formed on the sheet being conveyed is to be formed with a deviation from the sheet, and controls an image forming operation in accordance with this determination result.

Abstract: According to some examples, a method comprises successively transferring a series of images from an imaging surface to an intermediate transfer member, ITM, then from the ITM to positions on a web substrate. The method may comprise intermittently adjusting a position at which particular images are transferred to the ITM by a first defined distance laterally across the ITM and by a second defined distance longitudinally with respect to the ITM. The method may comprise adjusting a position at which the particular images are transferred to the web substrate by approximately the first defined distance laterally relative to the ITM and by approximately the second defined distance longitudinally relative to the ITM. The method may comprise, after a first defined number of intermittent position adjustments, changing a direction in which the position is adjusted. A print apparatus and a machine-readable medium are also disclosed.

Abstract: An image forming apparatus includes a first conveyor, a cutter, a second conveyor, a detection image forming section, a detector, and a controller. The first conveyor conveys a print medium. The cutter cuts the conveyed print medium. The second conveyor conveys, in a first direction, the print medium cut by the cutter. The detection image forming section forms a detection image on the print medium and the second conveyor. The detector detects, at two positions in a second direction, the detection image formed on the print medium or the detection image formed on the second conveyor. The controller varies one or both of a conveying speed of the print medium to be conveyed by the first conveyor and a cutting speed of the print medium to be cut by the cutter, on the basis of a comparison of the detection image detected at the two positions.

Abstract: An image forming apparatus includes: an image holding section; a transfer section that includes a transfer member, applies a transfer electric-field to a transfer region between the image holding section and the transfer member, and electrostatically transfers an image held by the image holding section onto a recording medium; a contact section that acts as an electrode to ground while being in contact with the recording medium when the recording medium passes through the transfer region; a first resistance detection section; a second resistance detection section; a comparison section that compares a first system resistance detected by the first resistance detection section with a second system resistance detected by the second resistance detection section; and a switching section that switches between constant voltage control and constant current control for the transfer electric-field produced by the transfer section depending on a result of comparison by the comparison section.

Abstract: According to one embodiment, there is provided a toner cartridge used in an image forming apparatus including a processor which forms a toner pattern image on a photoconductive member, transfers the toner pattern image on a medium, and changes an image forming condition based on a detection result obtained by optically detecting the toner pattern transferred onto the medium, the toner cartridge including: a toner accommodating container accommodating a toner, and a memory. The memory stores a plurality of reference data which are determined according to toner characteristics in the toner accommodating container and a value indicating an image forming execution amount, and are used for applying reference values for an optical detection result of a toner pattern formed by the toner on the medium.

Abstract: An image forming apparatus includes an image bearing member, a transfer member, a voltage source, a sensor, an acquiring portion, an information storing portion, and a controller configured to adjust the voltage applied to the transfer member. During continuous image formation for continuously forming images on a plurality of recording materials, a detection result of the sensor is corrected on the basis of the detection result of the sensor in a detection period in which a current recording material passes through a transfer portion, an index value relating to a toner image transferred onto a detection region passing through the transfer portion in the detecting period, and correction information, and then on the basis of the corrected value of the detection result, the controller controls the voltage applied to the transfer member for a subsequent recording material passing through the transfer portion.

Abstract: An image forming system includes first and second apparatuses. The first image forming apparatus includes a first image forming unit and a first transfer unit. The first image forming unit forms an image of at least one color. The first transfer unit transfers the formed image to a recording medium. The second image forming apparatus includes a second image forming unit and a second transfer unit. The second image forming unit forms an image different in at least a part of colors from the first image forming apparatus. The second transfer unit transfers the formed image to the recording medium on which the image has been formed by the first image forming apparatus. A total resistance of the second transfer unit along a direction in which a transfer current flows is larger than that of the first transfer unit.

Abstract: In the first charge amount acquisition operation, based on density of a plurality of toner images for measurement or based on a direct component of a developing current at the time of forming the plurality of toner images in addition to the density of the plurality of toner images for measurement, the charge amount acquisition section acquires a first toner charge amount that is a charge amount of toner included in the toner image for measurement. In the second charge amount acquisition operation, based on the toner density detected at the time of image formation and a relationship between the first toner charge amount and the toner density detected in the first charge amount acquisition operation, the charge amount acquisition section acquires a second toner charge amount that is a charge amount of the toner in the development device.

Abstract: An image forming apparatus includes an image bearing drum; a drum charging member, disposed at a charging position opposed to the drum, for applying the drum with a charging bias; a developing member for developing an electrostatic image formed on the drum with toner, with a developing bias; a transfer member for transferring a toner image from the drum onto a sheet, with a transfer bias; a transfer bias source for outputting the transfer bias; and a controller for effecting control to start raising of the transfer bias so as to correspond to a timing at which an area of the drum passing at a timing of starting of raising of the charging bias passes the transfer position and to complete the raising of the transfer bias so as to correspond to a timing at which an area of the drum passing at a timing of completion of raising of the charging bias passes the transfer position.

Abstract: A voltage maintenance element is connected to a contact member that contacts a primary transfer surface area of an intermediate transfer belt to which toner images are transferred from a plurality of image carriers between stretch members, in such a way as to prevent the electric potential of the intermediate transfer belt from varying between respective image forming stations.

Abstract: An image forming device of an intermediate transfer method of transferring a toner image formed on an image carrier to a sheet of paper through an intermediate transfer body, the image forming device including a transfer roller which is disposed facing the image carrier across the intermediate transfer body, and which forms a nip part with the image carrier; a movement mechanism which moves the transfer roller in a direction along a movement direction of the intermediate transfer body; a pressure varying mechanism which changes a pressing force of the transfer roller on the intermediate transfer body; and a hardware processor which controls the movement mechanism and the pressure varying mechanism, and which sets a contact position and the pressing force of the transfer roller on the intermediate transfer body based on paper information of the sheet of paper as an image formation target.

Abstract: An image forming apparatus includes a latent image bearer to bear a latent image, a potential sensor having a vibrator driven by a drive frequency to detect a surface potential of the latent image bearer, a developer bearer to bear developer that develops the latent image on the latent image bearer, and a power supply to apply a superimposed voltage obtained by superimposing an alternating voltage on a direct current voltage on the developer bearer. The frequency of the alternating voltage is not a multiple of the drive frequency and is a value obtained by adding a predetermined value to a multiple of the driving frequency.

Abstract: There is provided a voltage generation device for generating a voltage in which an alternating-current voltage is superimposed on a direct-current voltage, to apply the voltage to a rotary body. The voltage generation device includes a direct-current power supply, an alternating-current power supply, a variation phase determiner, and a voltage controller. The alternating-current power supply is connected to the direct-current power supply. The variation phase determiner is configured to determine whether variation of an output voltage of the alternating-current power supply and variation of an output current of the alternating-current power supply are in opposite phases. The voltage controller is configured to perform gain correction for the output voltage in a case where the variation of the output voltage and the variation of the output current are in opposite phases.