Abstract: A method for color registration includes determining if color registration is necessary, and if color registration is necessary, rotating an image forming medium and setting an optimum luminance of a registration sensor with respect to a rotating surface of the image forming medium, confirming an area with an undesirable surface condition on the image forming medium using luminance detected with respect to the rotating surface of the image forming medium during the setting of the optimum luminance, forming a preset mark for color registration adjustment excluding the area confirmed to have an undesirable surface condition, and carrying out color registration adjustment using the optimum luminance set with respect to the formed mark.

Abstract: A device includes a laser source configured to irradiate a toner image on a bearing member with light, a base extracting unit configured to extract a base area of a reflection waveform of light reflected from the toner image irradiated by the laser source, and a toner adhesion computing unit configured to compute the amount of toner adhesion in the toner image in accordance with a change in position of the base area of the reflection waveform.

Abstract: An image forming apparatus includes an image bearer; a toner image forming unit, a transfer unit, a detector, and a controller. The toner image forming unit forms a plurality of types of density detection patterns on the surface of the image bearer in mutually-different positions in a surface-movement direction of the image bearer. The density detection patterns have mutually-different lengths in a direction orthogonal to the surface-movement direction of the image bearer. The transfer unit transfers the density detection patterns onto the surface of the transfer member. The detector detects image densities of the density detection patterns transferred on the surface of the transfer member. The controller calculates an image density difference between the density detection patterns on a basis of a detection result obtained by the detector, and corrects a transfer bias for transferring a toner image on a basis of a value of the image density difference.

Abstract: An image forming apparatus including: a photosensitive member; a conveying member; an exposure head; a developing unit; an image forming unit; a concentration sensor having a first detection width in a conveyance direction and a second detection width in an axial direction of the photosensitive member; and a control unit, wherein the control unit controls the exposure head and the image forming unit to form a first image for correction, which includes a straight line part extending in the axial direction of the photosensitive member and having a length equal to or larger than the second detection width of the concentration sensor, on the conveying member, and wherein the control unit corrects a developing bias to be applied to the developing unit based on a detection result of the first image for correction by the concentration sensor.

Abstract: A wet-type image forming apparatus includes a density detection unit and a charge amount control unit for controlling the charge amount of toner on a liquid developer carrier. An image forming unit forms patch images while the charge amount control unit successively changes the charge amount of toner on the liquid developer carrier in a state in which a development bias is held at a prescribed value. The density detection unit detects the image density of each patch image thereby detecting a range of the charge amount of toner in which the image density of the patch image is almost saturated. The charge amount of toner in normal image formation is set to be equal to or greater than the range of the charge amount of toner in which the image density of the patch image is almost saturated.

Abstract: An image forming apparatus has a memory, an image forming unit, an intermediate transfer member, a density detector, a background density measurer, a test patch controlling unit and a density correcting unit. The density detector detects the density of the intermediate transfer member. The background density measurer stores background density, in the memory in correspondence with position information on the intermediate transfer member at a predetermined timing before a calibration for adjusting image formation density. The test patch controlling unit causes the image forming unit to form a test patch, on the intermediate transfer member while the intermediate transfer member is driven at a predetermined speed. The density correcting unit executes the calibration to adjust image formation density according to a difference between the background density stored in the memory when executing the calibration and corresponding to the position and density of the test patch.

Abstract: An image forming apparatus includes a measurement unit configured to emit light to a measurement target, and measure reflected light from the measurement target; a white reference plate disposed at a position opposed to the measurement unit; an image forming unit configured to form a measurement image on a sheet; and a calculation unit configured to, based on a measurement value of the white reference plate and a measurement value of the measurement image by the measurement unit, calculate a spectral reflectivity of reflected light from the measurement image. The calculation unit is configured to, after correcting a variation due to color change of the white reference plate with respect to the measurement value of the white reference plate, calculate the spectral reflectivity.

Abstract: In an image forming apparatus, a processor performs: a solid density stabilization of adjusting, in accordance with detected toner adhesion amounts of solid toner images of solid tone patterns, a condition to form solid images with respective target image densities; a misregistration reduction of adjusting, in accordance with detection timing of position detection toner images of misregistration detection patterns, a condition to reduce misregistration of toner images; and a halftone density stabilization of adjusting, in accordance with detected toner adhesion amounts of area coverage modulation toner images, a condition to form halftone images with respective target image densities.

Abstract: An image forming apparatus includes a controller configured to control a toner-image forming device to form a toner patch; and a detector configured to detect the toner patch on the image carrier. During a non-printing period, the controller causes a toner-image forming device to form toner patches, causes the detector to detect densities of the toner patches, and adjusts an image-forming condition of the toner-image forming device based on detected densities. During a printing period, the controller causes the toner-image forming device to form an output image in an image area and form fewer toner patches in a non-image area, causes the detector to detect densities of the fewer toner patches, and adjusts the image-forming condition of the toner-image forming device based on detected densities. The fewer toner patches are selected from and fewer than the plurality of toner patches formed during the non-printing period.

Abstract: An image forming apparatus includes an image forming part that forms a developer image, transfers the developer image to an intermediate transfer belt at a first transfer position and the developer image on the intermediate transfer belt to a sheet at a second transfer position. The image forming apparatus includes a detection part located between the first transfer position and the second transfer position and configured to detect a concentration of the developer image; and a controller configured to start a transfer of a concentration detection pattern that is a developer image for concentration detection during a period from when the developer image for print is transferred to the intermediate transfer belt to when the developer image for print is transferred to the sheet, and then to control the detection part to read the concentration detection pattern.

Abstract: An image forming apparatus includes: a detection unit detecting information about an image-adjusting pattern image fixed to a paper; a determination unit which, on the basis of an image-noise detecting pattern image that is formed on the paper prior to forming the image-adjusting pattern image, determines the presence or absence of an image noise generated in the image-adjusting pattern image; and a control unit. On the basis of the determination result of the determination unit, the control unit sets a detection region where the detection unit detects information about the image-adjusting pattern image, to a region where the image noise is not generated, and determines the image forming condition by using the information detected in the detection region.

Abstract: An optical sensor unit includes: a light-emitting device; a light-receiving device that receives light which is emitted from the light-emitting device and reflected from an object to be detected, and outputs an output value in accordance with the light; a shutter member that openably and closably covers an incident/exit plane having an exit part where light of the light-emitting device is emitted to the object to be detected and an incident part where light reflected from the object to be detected enters, and has a facing surface facing the incident/exit plane that is an inclined surface inclined to the incident/exit plane; and a corrector that corrects an output value of the light-receiving device when receiving light reflected from the object to be detected, based on an output value of the light-receiving device obtained by emitting light to the inclined surface of the shutter member.

Abstract: A method for compensation of banding in a marking platform includes: initiating a calibration stage; marking a test pattern over multiple intervals of a lowest fundamental frequency among marking modules; obtaining image data for the test pattern from a sensor; obtaining 1× signals from sensors associated with the marking modules; and processing the image data in relation to the 1× signals to form banding profiles for multiple marking modules. Alternatively, the method may include: processing image data in relation to 1× signals to form banding profiles for multiple marking modules; determining amplitudes in multiple banding profiles exceeds a threshold to identify dominant banding profiles; and processing dominant banding profiles to form dominant banding signatures.

Abstract: A image processing apparatus of the present invention comprises an image generation unit configured to generate image data of one page, a printing unit configured to mount color material on an intermediate transfer member to perform printing, and an obtaining unit configured to obtain a time (a time between print pages) showing a time interval between printing one page and printing next one page by the printing unit, and the printing unit outputs patches for adjusting density to be reproduced in the printing, to the intermediate transfer member in the time between print pages.

Abstract: A method and apparatus for faster monochrome printing in an in-line electrophotographic printer is described. The printer is configured such that it has more light emitting sources for use in an image transfer assembly for black than for image transfer assemblies for any other color in the printer. When printing a color print job, less than all of the light emitting sources in the black image transfer assembly are used. A print controller directs print data for a monochrome print job to all of the available light emitting sources in the black image transfer assembly and increases the print medium transport speed. The system and method may be configured to operate with dedicated data channels for each light emitting source or may share some data channels for monochrome and color print jobs.

Abstract: An image forming apparatus includes: a density detection unit that detects densities of an image developed by a developing unit at a plurality of positions in a main-scanning direction; a processing unit that obtains at least one of an amplitude and a phase of a first periodical density change of the image, of which cycle is a rotation cycle of a photosensitive drum, at the plurality of positions in the main-scanning direction on the basis of an output signal of the density detection unit, and corrects a drive signal for the light source so as to suppress the first periodical density change of the image at each position in the main-scanning direction on the basis of the rotation cycle of the photosensitive drum and at least one of the amplitude and the phase.

Abstract: An image forming device includes a density correction unit that corrects density based on a density detection value of the density correction pattern; a first density correction pattern generating unit that generates a first density correction pattern having low resolution; and a second density correction pattern generating unit that generates a second density correction pattern having high resolution. When a first density detection value of the first density correction pattern is greater than a predetermined threshold value, the density correction unit corrects the density by determining a density correction reflection rate, based on the first density detection value. When the first density detection value is less than or equal to the predetermined threshold value, the density correction unit corrects the density by determining the density correction reflection rate, based on a second density detection value of the second density correction pattern.

Abstract: An image forming apparatus includes an image forming unit having an exposure unit and a developing unit; a detection unit configured to detect a thickness and an area ratio of a toner layer of a pattern image formed by the image forming unit; a storage unit configured to store data indicating permissible ranges for the thickness and the area ratio of the toner layer; and a correction unit configured to change, when the thickness or the area ratio of the toner layer detected by the detection unit falls outside the corresponding permissible range indicated by the data stored in the storage unit, a spot diameter of the laser beam so that the thickness and the area ratio of the toner layer respectively fall within the permissible ranges.

Abstract: Provided are a first detecting unit having a singular first light-receiving element disposed to face a direction of normal reflection of light, the light having been emitted from a first light-emitting element toward a first detection image formed on the rotary member and reflected thereat, and a second detecting unit having a singular second light-receiving element disposed to face a direction different from a direction of normal reflection of light, the light having been emitted from a second light-emitting element toward a second detection image formed on the rotary member and reflected thereat. A value relating to toner density is obtained based on a first detection result detected by the first detecting unit and a second detection result detected by the second detecting unit.

Abstract: An image forming apparatus includes a forming unit configured to form a detection patch on a recording material and a detecting unit configured to detect the detection patch on the recording material being conveyed at a first conveying speed. After the detecting unit detects the detection patch, the recording material with the detected detection patch is conveyed at a second conveying speed higher than the first conveying speed.

Abstract: An image forming apparatus includes a toner image forming device for forming a color image. The toner image forming device forms a first color test image and a second color test image superposedly on an image conveying member so that at least one of a screen angle and a screen ruling with respect to the first color test image is different from that with respect to the second color test image. The image forming apparatus further includes a detecting device for detecting a distribution of heights of the first and second color test images formed superposedly on the image conveying member by the toner image forming device, and a control device for controlling a toner image forming condition of the toner image forming device on the basis of the distribution detected by the detecting device.

Abstract: An image forming apparatus includes an image forming unit configured to from a measurement image on a recording paper by a color material, a fixing unit configured to fix the measurement image onto the recording paper by heating, a measurement unit configured to measure the measurement image fixed onto the recording paper downstream of the fixing unit in a conveyance direction of the recording paper, and a control unit configured to perform control such that a period of time from when the recording paper passes through the fixing unit until the measurement unit measures color of the measurement image is longer than a period of time from when the recording paper passes through the fixing unit until the measurement unit measures density of the measurement image.

Abstract: The present invention provides a mechanism that more appropriately evaluates an image defect caused by a specific process in an image forming apparatus. An image forming apparatus of this invention performs colorimetry of a patch image at a spatial resolution corresponding to the spatial frequency of color unevenness caused by a specific process included in an image forming process. A statistic value based on the n-th (n is an integer of 2 or more) order central moment of a specific color component of a colorimetric value obtained by performing colorimetry at the spatial resolution is compared with a reference value, thereby detecting that the color unevenness caused by the specific process has occurred in the patch image.

Abstract: In an image forming apparatus, when it is determined that a pre-execution condition is satisfied, a cleaning unit is brought from a first state into a second state and is controlled to clean the bearing body. When it is determined that an execution condition is satisfied, a pattern acquisition is executed to form a pattern image on the bearing body by using an image forming section and to acquire characteristics of the pattern image based on detection results. The pre-execution condition includes a condition that a correlation value satisfies a first condition. The correlation value is correlated with an amount of deviation in characteristics of images formed by the image forming section. The execution condition includes a condition that the correlation value satisfies a second condition. The correlation value satisfies the first condition before satisfying the second condition.

Abstract: An image forming apparatus includes a latent image carrier, a charging device, a latent image forming device, a developing device, a transfer device, a toner amount detector, and a control circuit to execute an imaging condition determination process. The control circuit obtains a linear approximation formula of a developing potential and an amount of toner according to an exposure potential of the patch pattern and a detected amount of toner to calculate a developing gamma and a developing start voltage according to a gradient of the linear approximation formula, determines target charging potential, exposure potential and developing bias according to the developing gamma and the developing start voltage, determines an amount of a background potential to be corrected according to a difference between the developing start voltage and a target developing start voltage obtained according to environmental information, and corrects the target charging potential.

Abstract: The image forming apparatus includes process units that are closely arranged around respective photosensitive members and act on the photosensitive members, a light emission section that forms an electrostatic latent image for detection on the photosensitive member and a detection section that detects that the electrostatic latent image passes through a position facing the process unit, and a control section that performs misregistration correction control based on the detection result.

Abstract: In a method or device to control at least one property of a print image printed on a substrate, a first evaluation period is defined. A measurement value is determined with aid of an optical sensor which measures at least one determination point on the substrate within the first evaluation period, and also determining a position of the determination point within the first evaluation period. The determined measurement value is compared with a preset reference value. Depending on a result of the comparison, an inking of the substrate is controlled for the print image in at least one subsequent second evaluation period at a point within the second evaluation period which has a position within the second evaluation period that corresponds to said position of the determination point in said first evaluation period.

Abstract: An image forming apparatus executes banding correction at a level determined according to variation of the density characteristic of the image forming apparatus to achieve a high quality image. In the image forming apparatus, a banding correction unit acquires information about a cause of density variation that may occur in a sub scanning direction of a rotation member, which is used for forming a toner image on an image carrier based on input image information and sets, based on the acquired information, the level of the density correction, which is determined according to the density variation cause information.

Abstract: The image forming apparatus detects a color deviation amount in a timing when a developing roller separates from or contacts a photosensitive drum to set a difference in peripheral velocities between the photosensitive drum and an intermediate transfer belt or a transfer material conveying belt based on the color deviation amount and information about the use degree of the intermediate transfer belt.

Abstract: An image forming apparatus in which an optical sensor for detecting an adjustment toner image of black color is disposed on an image bearing member and an optical sensor for detecting adjustment toner images of other colors is disposed on an intermediate transfer member. With this configuration, even if the adjustment toner images of black and other colors simultaneously pass through a transfer portion for black color to reduce downtime, it is possible to reduce an effect on the subsequent image caused by light irradiation from the optical sensor and, at the same time, to prevent adjustment toner images of other colors from being excessively retransferred to the image bearing member (for black color) due to discharge. Control is performed such that a voltage less than a discharge start voltage is applied.

Abstract: One aspect of the present invention provides an information processing apparatus for determining a height of a toner image formed on a carrier, the apparatus comprising: a control unit configured to control an amount of irradiation light based on whether laser light irradiated by an irradiation unit is irradiated onto the toner image; an acquisition unit configured to acquire an image obtained by capturing reflected light of the laser light irradiated by the irradiation unit; and a determination unit configured to determine the height of the toner image based on the acquired image.

Abstract: In an apparatus which forms an adjustment toner image outside an image area in a direction orthogonal to a moving direction of an image bearing member, a toner change amount of the adjustment toner image which is directly transferred onto and adheres to a transfer roller without interposing a recording medium differs depending on a transfer electric field. Since the transfer electric field is in a direction for reversing a charging polarity of the toner, when the transfer electric field is large, the toner charge amount of the adjustment toner image is reduced. Therefore, in case that the transfer electric field is large, the cleaning electric field is set small. Thereby the toner of the adjustment toner image can be sufficiently cleaned off by an electrostatic cleaning member irrespective of the transfer voltage, and contamination on a back side of a recording material can be avoided.

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: An image forming apparatus includes: a photosensitive member configured to be rotated; scanning means for scanning, by light corresponding to image data, the photosensitive member that is charged, thereby forming an electrostatic latent image on the photosensitive member; and a contacting member in contact with the photosensitive member to form a nip portion. In a correction mode in which a shift of an image is corrected based on a detection result obtained by detecting, at the nip portion, an electrostatic latent image for correction formed on the photosensitive member by the scanning means, a width of the electrostatic latent image for correction is equal to or more than a width of the nip portion in a rotation direction of the photosensitive member.

Abstract: If the length of an adjustment toner image is longer than a circumferential length of a photosensitive member, a voltage which is less than a discharge start voltage is applied while a region of the photosensitive member irradiated with light by an optical sensor passes through a transfer portion. Further, a voltage which is greater than or equal to the discharge start voltage is applied while the photosensitive member rotates at least once after the region of the photosensitive member irradiated with light by the optical sensor passes through the transfer unit. As a result, density unevenness in the adjustment toner image and a potential change in the photosensitive member due to the optical sensor exposing the adjustment toner image are prevented.

Abstract: In an embodiment, a diffuse reflection output conversion method is executed in an apparatus detecting a plurality of gradation patterns. The apparatus includes a light emitter and light receiver, and detects specular reflection and diffuse reflection simultaneously. A region before specular reflection saturation is a region where the specular reflection component decreases and saturates at minimum level. A diffuse reflection detector is calibrated by: obtaining a diffuse reflection output resulting from an amount of attached powder at a border between the region before specular reflection saturation and the region after specular reflection saturation; calculating a ratio between the diffuse reflection output and a reference diffuse reflection output calculated in advance as a calibration coefficient; and multiplying a diffuse reflection output obtained from the gradation patterns by the calibration coefficient calculated at the calculating.

Abstract: An image forming apparatus includes an intermediate transfer body; a generating unit generating test pattern data; a storage unit storing a color displacement amount; a correcting unit correcting the test pattern data and image data based on the color displacement amount currently stored in the storage unit; a forming unit forming a test pattern based on the test pattern data corrected by the correcting unit on the intermediate transfer body at predetermined intervals, and forming an image based on the image data corrected by the correcting unit on the intermediate transfer body; a detecting unit detecting the test pattern formed on the intermediate transfer body; an updating unit determining an amount of change of the color displacement amount from a result of detection by the detecting unit, and updating the color displacement amount stored in the storage unit by using the amount of change of the color displacement amount.

Abstract: An image forming apparatus includes an image carrier, an image forming means for forming a patch image on the image carrier, a light emitting means, a plurality of light receiving means adjacently arranged so as to receive light reflected from the patch image when light is irradiated by the light emitting means onto the patch image which moves with movement of the image carrier and each including one or more light receiving elements, and an output means for outputting an output signal that depends on a difference between a received light quantity of a first light receiving means and a received light quantity of a second light receiving means that are respectively odd-numbered and even-numbered in the arrangement order of the light receiving means.

Abstract: An image data acquiring unit 32 acquires image data of a chart sheet and a reference chart and image data of the white sheet from the external imaging device. A shading correcting unit 34 generates shading correction data on the basis of a white sheet, and performs shading correction for the image data of the chart sheet and the reference chart using the shading correction data. A projective transforming unit performs a projective transformation for the image data of the chart sheet and the reference chart. A color value identifying unit identifies color values of patches in a test chart printed on the chart sheet and color values of patches in the reference chart after the shading correction and the projective transformation. A correction data generating unit generates image correction data on the basis of the identified color values of patches in the test chart and the reference chart.

Abstract: An image forming apparatus includes a first image bearing member, a second image bearing member, a developing device for forming a toner image on the basis of an electrostatic latent image formed on the first image bearing member, and an electrostatic latent image forming portion for forming an electrostatic latent image mark on the first image bearing member. In addition, a detecting portion detects a position of the electrostatic latent image mark, and an adjusting portion adjusts, on the basis of a detection result of the position of the electrostatic latent image mark, superposition between the toner image formed on the first image bearing member and the toner image formed on the second image bearing member. An electrostatic latent image which is undetectable by the detecting portion is formed between a formation region of the toner image on the first image bearing member and a formation region of the electrostatic latent image mark on the first image bearing member.

Abstract: According to an embodiment, provided is an image forming apparatus that forms an image on a moving body using toner. The image forming apparatus includes a pattern creating device that creates a first pattern for toner density detection and a second pattern for positional deviation detection on the moving body, the first pattern and second pattern being disposed to be arrayed in a main-scanning direction; a reflecting optical sensor including an emitting system that includes at least three light-emitting elements of which positions at least in the second direction are different and a light-receiving system that includes at least three light-receiving elements that receive light beams that are emitted from the emitting system and reflected from the first pattern and second pattern; and a processing device that obtains toner density information and positional deviation information simultaneously based on an output signal of the light-receiving system.

Abstract: An image forming apparatus includes: a conveyance member; a detection unit which outputs a detection signal according to a mark for image formation condition correction; an image forming unit which forms a print image and the mark; and a change unit which changes at least one of a printing reference position and a mark reference position such that an offset amount between the printing reference position and the mark reference position becomes larger as an angle difference between a sub-scanning direction and a conveyance direction of the conveyance member is larger, wherein the printing reference position is a basis of determining a formation position of the print image in a main scanning direction and the mark reference position is a basis of determining at least one of a formation position and a size of the mark in the main scanning direction.

Abstract: An image forming apparatus includes an image bearing drum for carrying a toner image; an intermediary transfer member; a primary transfer device for primary transfer of a toner image from the drum onto the intermediary member; a secondary transfer device for secondary transfer of the toner image from the intermediary member onto a sheet; and a cleaning unit for removing the toner on the intermediary member. The cleaning unit includes a scraping member for removing the toner deposited on the intermediary member, an accommodating portion for the removed toner, a discharging member, provided downstream of the scraping member with respect to a moving direction of the intermediary member, for moving the toner in the accommodating portion to the intermediary member by application of a voltage, and a regulating member contacted to the discharging member to regulate an amount of the toner deposited on the discharging member.

Abstract: An image forming apparatus reduces superimposing misalignment due to skew difference and registration difference and superimposing misalignment of visible image due to periodic position error generated on a plurality of latent image carriers respectively by correcting image information. A controller of the image forming apparatus has a deviation amount storing unit store data of magnification error in the sub-scanning direction e, executes rotation posture determining process that sets writing rotation posture as rotation angle posture at the time of starting writing latent image on photoconductors for Y, M, C, and K respectively, and has an image data correcting unit correct the image information based on the determined writing rotation posture and various error data (including magnification error in the sub-scanning direction e).

Abstract: An image forming apparatus includes an image carrier; an image forming unit; a processor for controlling the image forming unit according to a predetermined image forming condition setting data; an image density sensor to detect an image density of the toner pattern formed on the image carrier; a reference rotary position detector; an image density fluctuation data acquisition unit to obtain an image density fluctuation data of more than one circumferential length of the photoreceptor drum with reference to the reference rotary position detected by the reference rotary position detector based on a result related to the toner pattern formed on the image carrier detected by the image density sensor; and a correction data generator to generate a correction data to correct a reference image forming condition setting data with a correction amount corresponding to each rotary position of the rotary member to thus reduce the image density fluctuation.

Abstract: Provided are an image forming apparatus that, when a difference between a developing bias in correcting an image density and a reference developing bias has a value not less than a prescribed value that is set preliminarily, replenishes or consumes a toner forcibly, executes correction of the image density again, and controls the developing bias in such a manner that a toner density is controlled to fall within an appropriate range, and an image forming method using the same. When a difference between a developing bias value after correction of the image density and the reference developing bias becomes larger than the prescribed value to the plus side or the minus side, a toner density control portion performs control to consume or replenish a toner forcibly.

Abstract: An image forming apparatus includes first and second image bearing members configured to bear electrostatic latent images, a rotatable belt configured to receive toner images from the first and second image bearing members, and an executing portion configured to execute an operation in a correction mode for determining timing at which formation of the electrostatic latent image starts on at least one of the first and second image bearing members with respect to a widthwise direction of the belt between test toner images transferred onto the belt from the first and second image bearing members. In addition, first and second detecting members detect positions of the belt with respect to the widthwise direction, and a calculating portion calculates a movement distance of a predetermined point on the belt with respect to the widthwise direction.

Abstract: After a toner image is transferred from a photoreceptor to an intermediate transfer belt, a surface of the photoreceptor is destaticized by a static eraser including a plurality of light emitting elements arranged in an axial direction of the photoreceptor. A first density sensor and a second density sensor for detecting densities of toner applied to the intermediate transfer belt are provided at a position where a large quantity of light from the static eraser is applied to the photoreceptor surface and a position where a small quantity of light from the static eraser is applied to the photoreceptor surface. In a case where a density difference between the detected toner densities exceeds a predetermined threshold value, a destaticization controller carries out an additional destaticizing operation by the static eraser.

Abstract: An image forming apparatus includes an image bearer, a toner image forming unit, a detector, and a controller to adjust an image forming condition based on a detection result by the detector. During a non-printing period, multiple toner patterns are formed in an end and center portions of the image bearer in a direction perpendicular to a direction in which the image bearer moves, and a smaller number of toner patterns selected from the multiple toner patterns are formed in a non-image area, in the end portion of the image bearer, during a printing period. The controller determines a target density X of the smaller number of toner patterns by X=H (a mean detected density of the multiple toner patterns formed in the end portion)×J (a predetermined reference value)/I(a mean detected density of the multiple toner patterns formed in the end portion and in the center portion).

Abstract: The image forming apparatus includes a CPU that performs control to form an inspection image for determining whether or not banding is suppressed to be smaller than a predetermined threshold value; and a density sensor that detects an intensity of banding periodically occurring in a sub-scanning direction of the formed inspection image. If based the detected banding intensity, the CPU has determined that the banding is not suppressed to be smaller than the predetermined threshold value, the CPU performs control to not perform banding correction or performs control to re-set a relationship between a phase of a rotary member and correction information.