Abstract: An image forming apparatus includes a detection unit configured to detect a first scan beam from a first light source; and a control unit. The control unit performs corrections in which a light emission period of scan beams per pixel is changed in accordance with which section is scanned by the scan beams, and performs corrections in which a light exposure amount by which the photosensitive member is exposed to light by the scan beams is changed in accordance with which section in the main scanning direction is scanned by the scan beams. Based on a detection timing at which the detection unit has detected the first scan beam, the control unit controls scan start timings at which the scan beams start scanning of the photosensitive member.

Abstract: The present invention pertains to an image forming apparatus that includes a latent image bearer, an exposure device, a detector, and processing circuitry. The exposure device exposes the latent image bearer to form a latent image based on image data. The detector detects density unevenness, in a main scanning direction, of a toner image obtained by developing the latent image. The processing circuitry corrects only an exposure amount of the exposure device based on the density unevenness to form an image portion with a higher gradation than a prescribed gradation, the processing circuitry further configured to correct the exposure amount and the image data based on the density unevenness in the main scanning direction detected by the detector to form an image portion with a gradation equal to or lower than the prescribed gradation.

Abstract: An image forming apparatus includes a photosensitive drum which is rotatable; light-emitting portions arranged along a direction of a rotational axis of the photosensitive drum, the light-emitting portions emitting light based on image data in order to expose the photosensitive drum; a reference clock signal generation portion which generates a reference clock signal with a predetermined period; a modulated clock signal generation portion which generates a modulated clock signal with a predetermined modulation period by spreading a spectrum of the reference clock signal and by modulating the predetermined period, wherein the light-emitting portions emit light for a lighting time set based on the modulated clock signal; and a control signal generation portion which generates with a period of n times the predetermined modulation period (n is an integer greater than or equal to 1) a control signal for controlling a timing at which the light-emitting portions emit light.

Abstract: An image forming device includes an image data acquirer acquiring image data, a laser source emitting a laser beam, a laser driver forming an electrostatic latent image by irradiating a scanning surface of a charged photoconductor with the laser beam, based on the image data, a shading characteristic corrector correcting light quantity of the laser beam, an image former forming an image based on the electrostatic latent image, and a controller controlling the image data acquirer, the laser driver, the shading characteristic corrector, and the image former. The shading characteristic corrector includes a PDM signal outputter outputting a pulse density modulation signal based on the correction of the light quantity of the laser beam, a smoothing circuit smoothing the pulse density modulation signal to obtain an analog signal to be output, and a spread clock outputter outputting a clock subjected to spread spectrum to the PDM signal outputter.

Abstract: A light source according to the present invention is for an exposure device of a multifunction peripheral and includes a multi-beam light source. Two laser diodes included in the multi-beam light source are individually driven by a laser driver. Reference signals Vref1 and Vref2 used to control the light emitting power of the laser diodes are individually generated by two reference signal generation circuits. The reference signals Vref1 and Vref2 are each generated by processing including digital calculation, and at least one of the reference signals Vref1 and Vref2 includes a component for correcting the relative output difference of the laser diodes.

Abstract: According to one embodiment, an image reading apparatus includes an exposure unit, a light sensor, and a controller. The exposure unit selectively emits light to positions along a first scan direction to write pixels in accordance with a main scan line of image data. The light sensor is at a position to receive light from the exposure unit and is configured to output a synchronization signal according to the detection of the light emitted for each main scan line of image data. The controller adjusts a starting pixel position along the first scan direction for a main scan line of image data based on a change in an output interval of the synchronization signal resulting from a change in an intensity of light emitted by the exposure unit.

Abstract: According to one embodiment, an image forming apparatus includes a photoreceptor, a charging member, an application unit, and a control unit. An image is formed on the photoreceptor. The charging member is in contact with or close to a surface of the photoreceptor. The application unit applies a voltage to the charging member. The control unit performs control so that a current flowing through the charging member and the photoreceptor becomes a constant current when the photoreceptor is in an unused state, measures a voltage when the constant current flows and stores the measured voltage as a reference voltage, and controls the application unit to apply a voltage obtained by adding correction according to a value indicating a usage amount of the photoreceptor to the reference voltage.

Abstract: According to one embodiment, a driving apparatus includes a generating unit and a control unit. The generating unit respectively generates a plurality of pieces of driving data for causing each of a plurality of exposure heads to emit light for forming a plurality of element images. The control unit causes light emission start timings of the plurality of exposure heads based upon each of the plurality of pieces of driving data generated by the generating unit to be different between at least one of the exposure heads and other exposure heads.

Abstract: An image forming apparatus includes an image forming device and a control device. The image forming device forms an image on a recording medium. The control device controls an image forming process. The control device includes circuitry. The circuitry changes a plurality of partial images in a target image into a certain state. The target image is to be formed on the recording medium. The plurality of partial images are to be formed peripheral to a plurality of pattern images. Each of the plurality of pattern images is to be formed at a certain position on the recording medium. The circuitry further controls the image forming device to form the target image including the changed plurality of partial images and the plurality of pattern images on the recording medium, and corrects a position of the target image based on a detection result of the formed plurality of pattern images.

Abstract: In an example of a printing system, the amount of a printing fluid that is transferred from a developer unit onto an imaging plate is varied in order to alter the optical density of an area covered by the printing fluid.

Abstract: An apparatus identifies reflective surfaces used for scanning a first photosensitive member and a second photosensitive member. A first storage stores correction data corresponding to each of reflective surfaces of a first rotating polygonal mirror. A first correction unit corrects, on a basis of the correction data and information indicating the reflective surface, image data in association with the reflective surface. A second storage stores correction data corresponding to each of reflective surfaces of a second rotating polygonal mirror. A second correction unit corrects, on a basis of the correction data and information indicating the reflective surface, image data in association with the reflective surface.

Abstract: An image forming apparatus includes an apparatus body, a sheet stacking portion on which a sheet discharged from the apparatus body is to be stacked, an extension member, and an upper device. The extension member is rotatable about a rotating fulcrum between a first position at which the extension member is stored in the sheet stacking portion and a second position at which the extension member extends to downstream of the sheet stacking portion in a sheet discharge direction in which the sheet is discharged from the apparatus body. The upper device is disposed above the rotating fulcrum of the extension member and is supported to be openable by the apparatus body. The upper device in a closed state regulates a rotation of the extension member from the first position toward the second position.

Abstract: A configuration in which print heads disposed on an upper cover and a control substrate disposed on a housing are electrically connected via cables. The cables connect the print heads and the control substrate while passing through the back side of the rotating shaft in the housing so that a part of the cables contacts the rotating shaft or a grounded metallic receiving member disposed near the rotating shaft for supporting a part of the cables.

Abstract: An example shutter unit includes a motor including a driving shaft to rotate in a first rotation direction and to rotate in a second rotation direction opposed to the first rotation direction, a first shutter part to selectively expose a light window by receiving a driving force transferred from the driving shaft when the driving shaft rotates in the first rotation direction or the second rotation direction, and a second shutter part to selectively expose a sensor by receiving the driving force transferred from the driving shaft when the driving shaft rotates in the second rotation direction.

Abstract: A control circuit for an image forming apparatus includes a plurality of beam sources each configured to emit a beam, a photodetector configured to detect an intensity of the beam emitted from the plurality of beam sources, a processor configured to measure a slope efficiency of each beam source by controlling each beam source to emit the beam with different drive currents, and acquiring the intensity of each beam detected by the photodetector, and while a job is performed by the image forming apparatus, detect a current flowing in each beam source, determine an adjustment amount of a drive current for each beam source so that the beam source emits the beam at a predetermined output, based on the detected current and the measured slope efficiency, and adjust the drive current with the determined adjustment amount.

Abstract: In a case of performing a second rotation control to match the rotation phase of a first rotational polygon mirror with the rotation phase of a second rotational polygon mirror in a rising period, a period during which a non-image region is irradiated with light from both or one of a first light source and a second light source is controlled to be a second period longer than a first period.

Abstract: An information processing apparatus includes: a second reception unit configured to receive a predetermined signal outputted via a first signal line from the image forming unit; a third reception unit configured to receive a surface information outputted via a second signal line from the image forming unit; a storage unit configured to store, in association with the surface information, a plurality of pieces of correction data respectively corresponding to a plurality of reflecting surfaces; a correction unit configured to correct the image data to correspond to a reflecting surface onto which a light for scanning a photosensitive member is to be deflected, based on correction data; and a third output unit configured to, in response to receiving the predetermined signal, output the corrected image data.

Abstract: An information processing apparatus capable of specifying a reflection surface cheaply and accurately. A connected image forming apparatus generates a signal having first and second levels on the basis of information about reflection surfaces of a polygon mirror so that a period of the first level corresponding to a predetermined reflection surface becomes longer than that corresponding to the other reflection surfaces. The information processing apparatus detects a first timing at which the signal changes to the first level from the second level and a second timing at which the signal changes to the second level from the first level, specifies the reflection surface based on a period from the first timing to the second timing that is detected first after elapsing a first period from the first timing, and corrects the image data corresponding to the reflection surface according to the surface information and correction data.

Abstract: A period in which an adjustment unit adjusts a driving current such that the light irradiation unit emits a third light emission amount of light is switched to a period in which a light irradiation unit emits a second light emission amount of light, and the period in which the light irradiation unit emits the second light emission amount of light is switched to a period in which the light irradiation unit emits a first light emission amount of light.

Abstract: An optical scanning device includes a light source having plural light emitting portions, a deflection unit that deflects and scans plural light beams emitted from the light source in a main scanning direction, and plural optical element groups disposed between the light source and the deflection unit and including an optical element having a negative refractive power along a sub-scanning direction intersecting the main scanning direction. An interval in the sub-scanning direction of the plural light beams is adjusted by tilting the optical element having the negative refractive power on an axis along the main scanning direction.

Abstract: An image forming apparatus includes a light-receiving unit that includes light-receiving elements arranged along a movement direction of a target formed on an image carrier, and is arranged so as to receive light emitted from a light-emitting unit and specularly reflected off the image carrier; a member configured to limit a size, in the movement direction, of diffused reflection light that is incident on the light-receiving unit; a selection unit configured to select whether or not each of the light-receiving elements in the light-receiving unit is an effective light-receiving element; a generation unit configured to generate a detection signal from an output of the effective light-receiving element; and a detection unit configured to detect a target formed on the image carrier based on the detection signal.

Abstract: A method is provided wherein a metallic container is filled with a consumer identified beverage, seamed to a metallic end closure, distributed, and sold to the consumer. Thus, a consumer has influence and control over volume, qualities, and size of the beverage along with specific characteristics regarding the size and shape of the metallic container.

Abstract: An image forming apparatus has a control portion configured to control a charging bias to be applied to a charging member and a first exposure amount with respect to humidity inside an image forming apparatus and a thickness of a photosensitive layer of a photoreceptor, and the control portion controls the charging bias and the first exposure amount so that a potential difference between a non-image forming portion and the charging member increases as the humidity decreases, and decreases as the humidity increases.

Abstract: A relationship between a light amount of an exposure portion and a surface potential according to a use amount, a first detection light amount corresponding to a prescribed surface potential in the relationship where a use amount of a photosensitive member is a first use amount and a second detection light amount corresponding to the prescribed surface potential in the relationship where the use amount of the photosensitive member is a second use amount, which is greater than the first use amount, are acquired. The exposure portion changes, as an electrostatic image forming light amount, a first image forming light amount representing a setting value under the first use amount to a second image forming light amount representing a setting value under the second use amount on the basis of a ratio of the first detection light amount to the second detection light amount.

Abstract: An image reading apparatus includes an image reading chip for reading an image. The image reading chip includes a plurality of pixel units which include a light receiving element which receives light from the image so as to perform photoelectric conversion, an analog circuit, a logic circuit, and a power source pad to which a power source voltage is supplied. The image reading chip has a shape which includes a first side and a second side shorter than the first side. A distance between the analog circuit and a median point of the first side is shorter than a distance between the logic circuit and the median point of the first side, and a distance between the analog circuit and the power source pad is shorter than a distance between the logic circuit and the power source pad.

Abstract: An image forming apparatus includes: a first optical head group including first optical heads arranged in a sub-scanning direction; a second optical head group including second optical heads arranged in the sub-scanning direction and overlapping the first optical head group in a main scanning direction; a detector that detects displacement amounts between the first optical heads and the second optical heads; and a controller that performs registration based on the detection by the detector. The controller performs, with one of the first optical heads as a reference, registration on the other first optical heads, performs, with one of the second optical heads as a reference, registration on the other second optical heads, and performs registration between the first optical head group and the second optical head group based on a displacement amount between one of the first optical heads and one of the second optical heads.

Abstract: An optical writing control device controls emission or lighting of a light source onto a photoconductor surface in a latent image forming process and a discharge process, by either setting a light emission time longer in the discharge process or setting a resolution in a sub-scanning direction lower in the discharge process, compared to the latent image forming process.

Abstract: An optical scanner includes a light source; a rotating polygon mirror that reflects and deflects the light beam output from the light source; a drive unit that rotationally drives the rotating polygon mirror; a beam detection unit that detects the light beam; and a control unit that controls the light source and the drive unit. The control unit can control the drive unit with a detection result of the beam detection unit, and adjust a rotational speed of the rotating polygon mirror. The control unit has a high definition mode in which the rotational speed of the rotating polygon mirror is controlled with high accuracy at the time of normal light beam irradiation, and a light source life mitigation mode in which light beam irradiation is performed by controlling the output of the light source with keeping rotation of the rotating polygon mirror during standby.

Abstract: An image-forming apparatus includes a light-irradiation unit configured to move a spot of laser light on a surface of a photosensitive member at a non-constant scanning velocity in a main scanning direction to form a latent image on the photosensitive member, an image data correcting unit configured to correct a length in the main scanning direction of image data by inserting one or more image data pieces into the image data, the number of the image data pieces increasing as the scanning velocity increases, and/or extracting one or more image data pieces from the image data, the number of the image data pieces increasing as the scanning velocity decreases, and a brightness correcting unit configured to correct a brightness of the laser light so that an emission brightness increases as the scanning velocity increases and/or the emission brightness decreases as the scanning velocity decreases.

Abstract: When an edge effect or sweeping occurs in a developing material, pixels, among a plurality of pixels that configure image data, will arise in which a developing material consumption amount rises beyond an original consumption amount. A CPU corrects the developing material consumption amount for the pixels, among the plurality of pixels that configure the image data, in which the developing material consumption amount will rise beyond the original consumption amount.

Abstract: An image forming apparatus, including: a photosensitive member; a light source configured to emit a light beam; a deflecting unit configured to deflect the light beam to scan the photosensitive member to form an electrostatic latent image and having a rotary polygon mirror and a motor configured to rotate the rotary polygon mirror; a housing provided with the photosensitive member, the light source, and the deflecting unit; a temperature detecting unit configured to detect a temperature; and a control unit configured to pre-rotate the rotary polygon mirror before a start signal for image formation and to rotate, after the start signal, the rotary polygon mirror at a rotation speed higher than a rotation speed for pre-rotation of the rotary polygon mirror, wherein the control unit sets a target value of the rotation speed for the pre-rotation based on a result of detection by the temperature detecting unit.

Abstract: When an edge effect or sweeping occurs in a developing material, pixels, among a plurality of pixels that configure image data, will arise in which a developing material consumption amount rises beyond an original consumption amount. A CPU corrects the developing material consumption amount for the pixels, among the plurality of pixels that configure the image data, in which the developing material consumption amount will rise beyond the original consumption amount.

Abstract: The apparatus includes a CPU which executes, based on a detection result of a BD sensor, start-up control for controlling driving of a scanner motor, so that a rotation number of the scanner motor reaches a predetermined rotation number, and executes determination control for determining a voltage to be applied to a primary transfer unit based on a detection result of a transfer current detection circuit by a transfer voltage output circuit upon execution of image formation, and when an image forming station K which executes image formation is different from an image forming station Y including the BD sensor, the CPU parallelly executes the start-up control and determination control.

Abstract: An image forming apparatus includes: a rotatable image bearing member; a transferring member that forms a transfer nip portion with the image bearing member; a voltage application section that applies a voltage to the transferring member in such a manner that a certain amount of current flows through the transferring member; and a control section that sets a front-end current to a current that flows through the transferring member when a voltage having a polarity opposite to a transfer polarity and an absolute value substantially the same as or greater than an absolute value of a surface potential of the image bearing member is applied to the transferring member, the control section controlling the voltage application section in such a manner that the set front-end current flows through the transferring member when a front-end portion of a recording sheet in a conveyance direction passes through the transfer nip portion.

Abstract: A scanning system for use in an imaging apparatus includes a first light source and a second light source for emitting light beams for generating an image. A driver circuitry has first and second outputs connected to the first and second light sources, respectively, for controlling the first and second light sources. A signal transmitter includes a first interface for communicating a clock signal to the driver circuitry and a second interface for communicating an image information signal to the driver circuitry. During a clock cycle of the clock signal, the driver circuitry captures a first bit information from the image information signal at a rising edge of the clock signal and a second bit information from the image information signal at a falling edge of the clock signal. Thereafter, the driver circuitry drives the first and second light sources based on the first and second bit information captured, respectively.

Abstract: A light scanning device that performs rapid scanning synchronization timing detection to thereby enable automatic light amount control to be executed rapidly and with high accuracy. A light amount sensor disposed on a scanning line of the laser light receives the laser light. A controller controls the timing of emission by the laser emitting device and a light amount of the laser light based on image data, according to an output from the light amount sensor. A temperature sensor detects the temperature of the laser emitting device or in the light scanning device. A storage section stores data indicative of a relationship between temperature, current supplied to the laser emitting device, and light amount. A controller controls current to be supplied to the laser emitting device based on temperature detected by the temperature detecting unit and data stored in the storage section.

Abstract: In an image forming apparatus, in the case where a time necessary for a developer bearing member to rotate from a measurement position where an attracting unit attracts the toner on the developer bearing member to a developing position at which an electrostatic latent image on the photosensitive member is developed by a toner on the developer bearing member is represented by a time Tqcm, a time necessary for the photosensitive member to rotate from an exposure position at which an exposure unit exposes the photosensitive member to the developing position is represented by a time Tetd, and a time necessary for a control unit to control an exposing condition based on a charge amount measured by a measuring unit is represented by a time Tp, the attracting unit is disposed so that Tqcm?Tedt+Tp holds true.

Abstract: Provided is a charging member contamination determining device including plural units that includes a charging member, a member to be charged and a measuring section that measures a discharging current value between the charging member and the member to be charged, a calculating section that calculates a difference between current values measured by two units among the plural units, and a determining section that determines the presence or absence of contamination in the charging member based on the difference between the current values for each combination of two units calculated by the calculating section.

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 color image forming apparatus has a light emitting element emitting light, a laser driving unit causing the light emitting element to emit light of a light amount at a first emission level for visualizing a toner image onto a first area where the toner image is to be visualized on a charged photosensitive member and to emit light of a light amount at a second emission level for weak emission onto a second area where the toner is not to be adhered to the charged photosensitive member. In addition, an acquiring unit acquires information of an integrated number of rotations of the photosensitive member, a drive current adjusting unit adjusts the drive current for the second emission level, and changes a magnitude of the drive current for the second emission level in accordance with the information of the integrated number of rotations of the photosensitive member.

Abstract: An image forming apparatus includes an exposure control unit that performs control, based on a shift-amount of an exposure position from an ideal position, the shift-amount being obtained from a detection-result of a misregistration correcting pattern image, to shift at least one of an exposure timing corresponding to first image data which is input to one of two electric cables in contact with a target electric cable and an exposure timing corresponding to second image data which is input to another one of the two electric cables, with respect to an exposure timing corresponding to target image data being input to the target electric cable both sides of which are in contact with the two other electric cables, among a plurality of the electric cables which corresponds respectively to a plurality of the exposure units provided for each of a plurality of colors.

Abstract: An image forming apparatus includes an image bearer; a charger to charge the image bearer; an electrostatic latent image former to form an electrostatic latent image on the image bearer; an image developer to develop the electrostatic latent image with a toner to form a visual toner image; a transferer to transfer the toner image on a transfer material; a toner concentration calculator to calculate a concentration of the toner; and an optical detector. At least a toner patch image is formed on the image bearer with an irradiation quantity set such that an irradiated part potential is larger than a developing condition, the toner patch image is read by the optical detector, and the charging condition is corrected on the basis of a difference between a toner concentration of the toner patch image and a target toner concentration.

Abstract: An image forming apparatus includes: a pseudo-halftone processing unit that processes input image data to output image data of first resolution; a resolution converting unit that converts the image data of the first resolution into image data of second resolution that is higher than the first resolution; a modulation-signal generating unit that generates a modulation signal obtained by modulating the image data of the second resolution according to a clock signal; and a light-source driving unit that drives a light source according to the modulation signal. The pseudo-halftone processing unit converts a region of pixels having the same pixel value into a parallel line pattern that is formed with a plurality of parallel lines oblique relative to a direction of arrangement of pixels. The resolution converting unit generates the image data o in which each edge of the lines forming the parallel line pattern is smoothed.

Abstract: An image forming apparatus includes a process unit arranged in the vicinity of the circumference of each photosensitive member and the process unit is configured to act on the photosensitive member in forming a toner image thereon. The image forming apparatus detects a time period since a laser beam emission unit emits a laser beam to the photosensitive member to form an electrostatic latent image for detection until the formed electrostatic latent image for detection or a toner image based on the electrostatic latent image for detection reaches the process unit, and performs color misregistration correction control based on the result of detection. In this case, a control unit at least decreases the light amount of a pre-exposure LED when the electrostatic latent image for detection passes through a position facing the pre-exposure LED.

Abstract: An image forming apparatus includes an update unit configured to cause an image forming unit to form a first measurement image, cause a measurement unit to measure the first measurement image, and update a process condition based on a measurement result; a first determination unit configured to cause the image forming unit to form a plurality of second measurement images, cause the measurement unit to measure the plurality of second measurement images, and determine the process condition based on a measurement result, the plurality of second measurement images being formed according to a plurality of test process conditions; and a second determination unit configured to determine the plurality of test process conditions, based on an environment information obtained by an obtainment unit and the process condition updated by the update unit.

Abstract: An image forming apparatus includes a rotatable photoconductor, a charging unit, an exposure unit to expose the photoconductor to reduce an electrical potential at the photoconductor, a developing unit to charge the toner held on a toner bearing member with friction and attract the toner to the exposed portion on the photoconductor by supplying a development voltage from a first power source and using an electrical potential difference between the toner bearing member and the photoconductor in the development area, a reverse development voltage controller to supply a reverse development voltage while a non-charged portion on the photoconductor passes the development area, and a developer reducing potential applier to supply a development restraining potential and an absolute value smaller than a target charging potential to the photoconductor while the reverse development voltage is supplied.

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: The image forming apparatus includes a determination unit configured to determine whether or not a polygon mirror has converged to the number of rotations that allows image formation to be performed, and the determination unit is capable of detecting a first timing and a second timing and determines that the polygon mirror has converged to a number of rotations that allows the image formation to be performed based on an earlier one of the first timing and the second timing.

Abstract: An image forming apparatus includes a first image forming portion including a first photosensitive member, a first charging member to electrically charge the first photosensitive member, and a first exposure member to expose to light the charged first photosensitive member to form an electrostatic latent image, and a second image forming portion including a second photosensitive member, a second charging member to electrically charge the second photosensitive member, and a second exposure member to expose to light the charged second photosensitive member to form an electrostatic latent image.

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