Abstract: An image forming apparatus includes an irradiation unit for irradiating an image carrier having a detection image with light; a light-receiving unit for receiving reflected light of the light irradiated by the irradiation unit and outputting a detection signal corresponding to a light-receiving amount of the reflected light including a specular-reflected light component; and a detection unit for detecting one of position information and density information of the detection image based on a signal corresponding to a difference between a value of the detection signal corresponding to the light-receiving amount of the reflected light from a first position where the detection image is formed and a value of the detection signal corresponding to the light-receiving amount of the reflected light from a second position different from the first position.

Abstract: An image forming device includes a plurality of image formation units each configured to form an image of one of a plurality of colors, and a patch image transfer unit configured to control transfer conditions during transferring a patch group that is a pattern for detecting a position shift and formed on an intermediate transfer belt onto a secondary transfer belt. The patch image transfer unit is configured to transfer patches of at least single color for which a band of transfer efficiency is narrowest, of the patch group, onto the secondary transfer belt under transfer conditions for the color, and during transition to the transfer conditions for the color from other transfer conditions or during transition from the transfer conditions for the color to the other transfer conditions, patches of a color other than the color, of the patch group is transferred onto the secondary transfer belt.

Abstract: A mark detecting device includes: a belt on which a plurality of marks are provided along a moving direction of the belt; a light-emitting element configured to irradiate at least one of the marks with light; a light-receiving element configured to receive a reflected light reflected from at least one of the belt and the mark of the light irradiated from the light-emitting element and output a signal; and a light amount adjuster configured to compare a first value obtained from the signal output by the light-receiving element and a second value obtained from a signal output by the light-receiving element after the first value is obtained, and to perform light amount adjustment of the light-emitting element when a difference between the first value and the second value is a first threshold or more.

Abstract: An image forming apparatus includes a belt, a plurality of image forming devices including a photosensitive member, a developing device, a transfer device and a blade, and a control device configured to form a pattern image on a first photosensitive member, when an image to be printed on a sheet is not formed, by applying a developing voltage to a first developing device, an absolute value thereof is greater than that when an image to be printed on a sheet is formed, transfer the pattern image onto the belt and apply a transfer voltage or transfer current having the same polarity as that applied to a second transfer device when an image to be printed on a sheet is formed to the second transfer device when the pattern image to be conveyed by the belt passes the second transfer device.

Abstract: A curling detection device includes an endless belt entrained around at least two rollers, a conveyance unit that conveys the endless belt by driving the rollers, an image forming unit that forms an image by transferring a toner image to either a surface of the endless belt directly or a recording medium on the endless belt, a pattern image forming controller that instructs the image forming unit to form lines of a curling detection pattern at predetermined intervals in a conveying direction of the endless belt and a predetermined angle against the conveying direction of the endless belt at a predetermined timing, a curling scanning unit that scans the curling detection pattern, and a detecting unit that detects a curling of the endless belt based on the interval of the curling detection pattern scanned by the curling scanning unit.

Abstract: A printing apparatus includes a belt mover for an endless belt that transports a recording medium, a feed amount calculator that calculates an amount of feed of the belt mover, a movement amount detection sensor as a movement amount measurer that measures actual amount of movement of the endless belt by image processing, a compensation table storer that stores a compensation table for compensating a transport error of the endless belt, and a control portion that calculates the amount of feed that is to bring about a predetermined amount of movement of the endless belt by using the feed amount calculator and by referring to the compensation table storer, moves the endless belt by using the belt mover on the basis of the amount of feed, compares the actual amount of movement of the endless belt measured by the movement amount detection sensor and the predetermined amount of movement.

Abstract: A set of adjustment pattern images includes first adjustment pattern images and second adjustment pattern images to be formed on a first side and a second side of a recording sheet, respectively, by an image forming apparatus. The set of adjustment pattern images is employed to adjust an image forming position by the image forming apparatus such that an image forming position of the first adjustment pattern images is aligned with an image forming position of the second adjustment pattern images. The set of adjustment pattern images includes at least two first adjustment pattern images that are spaced from each other and at least two second adjustment pattern images that are spaced from each other, and the first adjustment pattern images on the first side and the second adjustment pattern images on the second side are arranged alternately with each other.

Abstract: An image formation apparatus includes: image formation units mounted in series in a conveyance direction of a transfer object and that form images and correction patterns of different color developers on the transfer object; a sensor that detects a color misregistration, by the emission of a detection light to the correction pattern on the transfer object and the reception of a reflection light from the transfer object; an identification unit that identifies, out of the image formation units, a first image formation unit using a first developer which is the developer with the lowest reflectance, based on reflectance information indicating reflectances of the developers for the image formation units, or based on color information indicating the colors of the developers for the image formation units; and a corrector that corrects the color misregistration with respect to the first image formation unit identified by the identification unit.

Abstract: An image forming apparatus forms an image by optical scanning. The image forming apparatus includes: a light source; an image processing unit that processes image data; a modulation signal generation unit that generates a light source modulation signal; a light source drive unit that drives the light source based on the light source modulation signal; and a correction value identifying unit that identifies a correction value for correcting a registration error of an image to be formed. The image processing unit performs first image processing of image data with first resolution based on a correction value identified by the correction value identifying unit, the first image processing including deformation processing and gradation processing of the image data. The modulation signal generation unit converts image data processed in the image processing unit into image data with resolution higher than the first resolution and performs second image processing.

Abstract: An image forming apparatus includes a detector for detecting one of position and density information of a detection image based on a signal corresponding to a difference between a value of a detection signal corresponding to a first position of one of the detection image on an image carrier and a surface of the image carrier and an average value of a value of the detection signal corresponding to a second position on a downstream side with respect to the first position in a moving direction of the detection image and a value of the detection signal corresponding to a third position on an upstream side with respect to the first position in the moving direction during a time when the detection image formed on the image carrier passes through an irradiation region of an irradiation device.

Abstract: Color registration errors are corrected for print jobs including periodic image content. A first subset of document pages are printed and the resulting color registration errors are measured. The measured color registration errors are analyzed to identify the presence of a periodic pattern of color registration errors having a repeat period. A repeating pattern of color registration correction values are determined corresponding to the periodic pattern of color registration errors. A second subset of the document pages is printed using the determined repeating pattern of color registration correction values.

Abstract: The image forming apparatus comprises a photosensitive drum which is replaceable, an intermediate transfer belt unit which is brought into contact with the photosensitive drum to operate and which is replaceable, and a separation motor configured to move the intermediate transfer belt unit in a direction toward the photosensitive drum and in a direction away from the photosensitive drum. The image forming apparatus causes the separation motor to separate the intermediate transfer belt unit and the photosensitive drum from each other in a case where at least one of the photosensitive drum and the intermediate transfer belt unit reaches the replacement timing when the image forming apparatus shifts to a low-power state in which power consumption of the image forming apparatus is suppressed compared with that of the image forming apparatus in a normal operation.

Abstract: An apparatus for reducing registration errors in a media handling device. The apparatus including an image-bearing member having sheets individually pass across the image-bearing member. Each sheet pass corresponds to one of a series of iterations between the image-bearing member and the sheets. The image-bearing member is operatively coupled to a controller for regulation motion of the image-bearing member. The controller receives input signals representing at least one measured disturbance. Each disturbance being defined by a pattern of image-bearing member movement away from and substantially returning to a reference state of motion. A repetition of the pattern being coincident with at least one of the iterations, wherein based on the measured disturbance, the reference state and an indication associated with when the pattern will repeat, a modified signal is generated for the actuator to adjust the image-bearing member motion in coordination with the indication.

Abstract: A target cycle recording portion (821) records target cycle data (Tref) into a first ring buffer (824) each time a reference pulse signal (Ps) is generated, thereby recording the target cycle data (Tref) sequentially into the first ring buffer (824). A measured cycle recording portion (822) records measured cycle data (Tenc) into a second ring buffer (825) each time an encoder pulse signal (Pe) is generated, thereby recording the measured cycle data (Tenc) sequentially into the second ring buffer (825). A phase error calculating portion (823) calculates a phase error PHE by integrating a difference between the target cycle data (Tref) and the measured cycle data (Tenc) that are sequentially recorded in data buffers respectively in correspondence with each other in the two ring buffers.

Abstract: An image forming apparatus includes a rotating member; a forming unit for each of a plurality of colors used in image formation, configured to form a developer image of the corresponding color on the rotating member or on a recording medium on the rotating member; a driving unit configured to rotate the rotating member; a period detection unit configured to detect a rotation period of the rotating member; and a control unit configured to, according to a detection result detected by the period detection unit, obtain a variation in the rotation period of the rotating member due to a change in the driving unit, and perform correction control for misregistration in the developer image formed on the rotating member or on the recording medium on the rotating member by the forming unit.

Abstract: An image forming apparatus includes image forming sections each including a developing section having a developer bearing member and a developer supply unit and a transfer unit that transfers an image developed on a photoconductor by the developing unit onto a transfer body, a controller that controls a driving time of the developer bearing member so that developer is born on the developer bearing member during a period when image formation is not performed and the developer attached to the transfer body by the image forming sections does not overlap, a detector that detects the attached developer by each image forming section, and a specification unit that specifies the image forming section which attaches the developer to the transfer body, on the basis of a time from when the controller starts driving the developer bearing member to when the detector detects the developer attached to the transfer body.

Abstract: In an aberration-correcting method according to an embodiment of the present invention, in an aberration-correcting method for a laser irradiation device 1 which focuses a laser beam on the inside of a transparent medium 60, aberration of a laser beam is corrected so that a focal point of the laser beam is positioned within a range of aberration occurring inside the medium. This aberration range is not less than n×d and not more than n×d+?s from an incidence plane of the medium 60, provided that the refractive index of the medium 60 is defined as n, a depth from an incidence plane of the medium 60 to the focus of the lens 50 is defined as d, and aberration caused by the medium 60 is defined as ?s.

Abstract: Disclosed is an inkjet printing apparatus with an inkjet printing unit performing printing onto web paper to be transported. The apparatus includes a drive roller transporting the web paper, a transportation velocity detector detecting a transportation velocity of the web paper, an encoder generating a timing reference signal of the printing by the printing unit in accordance with transportation of the web paper, the encoder being disposed in a transport roller, a printing correction data generator generating printing correction data in accordance with the transportation velocity and the timing reference signal so as to correspond to a time-dependent variation of the transport roller provided with the encoder; and an offset corrector correcting the printing of the inkjet printing unit to the web paper in accordance with the printing correction data.

Abstract: The rotation speed of an intermediary transfer belt 41 when it is brand-new is stored as a reference rotation speed. Registration patches Rk to Ry are formed to calculate displacement amounts, and based on the rotation speed difference between the rotation speed of the intermediary transfer belt 41 and the reference rotation speed, the calculated displacement amounts are corrected into displacement amounts expected when the secondary transfer roller 42 is contacted with the intermediary transfer belt 41. Next, based on the corrected displacement amounts, the positions at which exposing devices 60K to 60Y form electrostatic latent images are corrected. Thus, registration correction can be performed accurately without requiring too much time or toner, with consideration given to the difference in the rotation speed of the intermediary transfer belt 41 depending on whether the secondary transfer roller 42 is contacted with or released from the intermediary transfer belt 41.

Abstract: An image forming apparatus includes a plurality of latent image bearers, a latent image writer, a plurality of developing units, a primary transfer unit, a secondary transfer unit, an adjuster, a pattern image formation controller, a color deviation detector, a color deviation correction controller, and an image-formation-mode setting unit. The color deviation correction controller executes color deviation correction control in the separated state. The image-formation-mode setting unit sets a normal linear-velocity image formation mode in which an image is formed at a normal linear velocity and at least one non-normal linear-velocity image formation mode including a low linear-velocity image formation mode in which an image is formed at a low linear velocity slower than the normal linear velocity.

Abstract: In an image forming apparatus, an error detection mark is formed by using an image forming unit on the surface of a carrier along a detection line passing through an exposure position in a carrier moving direction. The error detection mark includes a first mark and a second mark spaced from each other by a fixed distance in the carrier moving direction. The error detection mark is measured by the sensor. A measurement error of the sensor for a registration mark is determined based on the measured values for the first mark and second mark. A registration mark is formed by using the image forming unit on the surface of the carrier on the detection line. The registration mark is measured using the sensor. Offset of an image-forming position is corrected based on the determined measurement error and a measured value for the registration mark.

Abstract: An image forming apparatus includes a generation unit configured to generate correlation data indicating a relationship between a relative position of a first image and a second image corresponding to a first speed and a relative position of the first image and the second image corresponding to a second image forming speed; a controller configured to, in a case where a image forming unit forms an image at the second speed, correct a relative position of the first image and the second image based on first information and on correlation data; and a prohibition unit configured to prohibit formation of the measurement image at the second speed in a case where a housing unit does not house a predetermined recording material corresponding to the second speed.

Abstract: An image forming apparatus includes a unit configured to correct a relative position of a first image and a second image, and a controller configured to form a first measurement image in a case where a first condition is satisfied, and to form the first measurement image and a second measurement image in a case where a second condition is satisfied. The controller is further configured to, in a case where the first condition is satisfied, determine whether or not the second condition is satisfied before the first condition is satisfied next, and in a case where the second condition is satisfied before the first condition is satisfied next, cause an image forming unit to form the first measurement image and the second measurement image.

Abstract: A belt transport apparatus includes a first computation unit that computes a first deviation between a surface speed of a belt and a target speed of the belt, a position controller that computes a speed correction value based on the first deviation, a speed deviation ratio computation unit that computes a ratio of the belt surface speed and a rotational speed of a driving roller, a second computation unit that selectively computes according to predetermined conditions one of a second deviation between the rotational speed and a sum of an increment of the speed correction value and the target speed and a third deviation between the rotational speed and a sum of a value corrected according to the ratio stored in a storage unit and the target speed, and a control unit that controls the rotational speed based on the one of the second and third deviations.

Abstract: A color image forming apparatus includes an image forming unit configured to form misregistration detection patterns, a transfer member on which the misregistration detection patterns are transferred, a plurality of detection units configured to detect the misregistration detection patterns transferred onto the transfer member, a calculation unit which calculates misregistration values from detection results detected by the plurality of detection units, and a control unit which controls an image forming condition by the image forming unit based on the misregistration values. The image forming unit forms first and second marks at different positions in a direction perpendicular to a moving direction of the transfer member as the misregistration detection patterns, and the calculation unit calculates the misregistration values based on detection results of the first and second marks.

Abstract: An image forming apparatus includes a process unit configured to act on a photosensitive member, detecting unit configured to detect a latent image formed on the photosensitive member, and a color misalignment correcting unit configured to perform color misalignment correction based on time information obtained by detecting, by the detecting unit, a detection pattern including a plurality of latent image marks for color misalignment correction. In addition, a storage unit stores a weighting coefficient of each latent image mark. The color misalignment correcting unit is further configured to weight the time information by using the corresponding weighting coefficient and perform color misalignment correction.

Abstract: An image forming apparatus includes: an image forming unit configured to form developer images of a plurality of colors on an image carrier; and a control unit configured to execute a first correction control and a second correction control that has a higher correction precision than the first correction control in order to correct misregistration between the developer images formed by the image forming unit. The control unit is further configured to execute the second correction control when a cumulative correction error, which is a cumulative value of correction error occurring when performing misregistration correction using the first correction control, exceeds a first threshold.

Abstract: An image forming apparatus includes a switching unit that can switch polarities of potentials of an intermediate transfer member generated at a primary transfer part and a secondary transfer part in synchronization, and a control unit that executes adjustment processing in which a potential having a polarity opposite to the polarity upon the transfer is generated at least one of the primary transfer part and the secondary transfer part, in which the control unit controls the switching unit in a manner that, in a case where the adjustment processing is performed in a course of continuous image formation on a plurality of transfer materials conveyed to the secondary transfer part, a timing for generating the potential having the opposite polarity corresponds to a timing at which toner images are not transferred at both of the primary transfer part and the secondary transfer part.

Abstract: In an image forming apparatus, when some of a plurality of image supporters which are preceded by another image supporter on an upstream side of the carrying direction are referred to as downstream side image supporters, a control section derives a toner supply amount for each of positions in a main-scanning direction for each of downstream side image supporters based on image data for the downstream side image supporters and image data for an upstream side image supporter, and thereafter generates patch image data that represents the derived toner supply amount, and the exposure section further scans each of the downstream side image supporters in the main-scanning direction with an optical beam modulated according to the patch image data generated by the control section.

Abstract: An image forming apparatus includes a generation unit configured to generate correlation data indicating a relationship between a relative position of a first image and a second image corresponding to a first speed and a relative position of the first image and the second image corresponding to a second image forming speed; a controller configured to, in a case where an image forming unit forms an image at the second speed, correct a relative position of the first image and the second image based on first information and on correlation data; and a prohibition unit configured to prohibit formation of the measurement image at the second speed in a case where a housing unit does not house a predetermined recording material corresponding to the second speed.

Abstract: An image forming apparatus, a color registration test pattern of the image forming apparatus, and a method of forming the color registration test pattern are provided. A time required for color registration may be reduced by minimizing a region in which a color registration test pattern is formed on an intermediate transfer body. A control method of the image forming apparatus, which includes photosensitive media arranged side by side to correspond to colors in a rotation direction of the intermediate transfer body, includes forming first patterns of the colors arranged in a single row in a sub-scanning direction in a first region of the intermediate transfer body over a single-rotation period of the photosensitive media, and forming second patterns of the colors arranged in a single row in the sub-scanning direction in a second region of the intermediate transfer body over another single-rotation period of the photosensitive media.

Abstract: An image forming apparatus includes an image bearing member, a controller controls a first and the second image forming unit to form a measurement image on the image bearing member, wherein the measurement image is composed with a first measurement image having a first color, and a second measurement image having a second color with a lower reflectance than the first color, a radiation unit emits a irradiation light to the measurement image, a light receiving unit receives a reflected light from the measurement image, a comparison unit compares a light amount of the reflected light from the measurement image with a threshold value, and a changing unit increases the threshold value, if a measurement time period during which a light amount of the reflected light from the measurement image is equal to or greater than the threshold value is longer than a predetermined time period.

Abstract: An image forming apparatus includes an image forming device which forms an image on a rotation member, a sensor, and a controller. The controller executes an overlapping pattern detection processing which detects a positional deviation amount using an overlapping pattern including a plurality of overlapping marks with overlapped colorant images of two colors, a non-overlapping pattern detection processing which detects a positional deviation amount using a non-overlapping pattern including a plurality of marks, each having a single color, and an execution processing which executes the overlapping pattern detection processing or the non-overlapping pattern detection processing based on a condition.

Abstract: An image forming apparatus including a body provided at one side thereof with an opening, a transfer device movably installed at the body so as to be detachable through the opening, and a locking lever rotatably installed at the transfer device, wherein the locking lever rotates between a first position at which one end of the locking lever protrudes from the transfer device and a second position at which the one end is accommodated within the transfer device, and the body includes a locking protrusion that is locked with other end of the locking lever in a state that the locking lever is at the first position, so that only in a state that a worker rotates the locking lever while gripping the transfer device, the transfer device is separated from the body, thereby separating the transfer device in a safe manner.

Abstract: Disclosed is an image forming apparatus including: an image forming unit configured to form an image on a conveyed recording medium; a density detecting unit configured to detect a density of the image formed on the recording medium; a phase detecting unit configured to detect a phase of a predetermined periodic member; a control unit configured to instruct the image forming unit to form a pattern on the recording medium, and to prepare correction data for one period of the periodic member from density data obtained by detecting the density of the pattern; and a density unevenness correcting unit configured to correct image data by repeatedly applying the correction data for one period so as to match with the phase of the periodic member, and to correct the density unevenness in the conveying direction, which is caused due to the periodic member.

Abstract: An image forming apparatus is provided. The image forming apparatus includes an image forming unit configured to form a mark, a conveyance member configured, to convey the mark, a sensor configured to read the mark conveyed by the conveyance member, a measurement unit configured to measure a moving time period between a time when the image forming unit forms the mark and a time when the mark conveyed by the conveyance member is read by the sensor, and a determination unit configured to determine whether a traveling speed of the conveyance member is appropriate based on the moving time period measured by the measurement unit.

Abstract: First position information formed on a conveyance body is read by an information detecting portion, and second position information formed on a second image carrier is read by the information detecting portion. Control is made such that a position of an image on the second image carrier matches with a position of an image on the conveyance body from information read by the information detecting portion in transferring the image from the second image carrier to the conveyance body. The information detecting portion is held by a hold member and is disposed at a transfer region.

Abstract: An image forming apparatus includes a plurality of image bearing members and a control unit. After an image forming mode starts until a toner image is primarily transferred onto an intermediate transfer member from an uppermost-stream image bearing member of the plurality of image bearing members provided at an uppermost stream position, the control unit is configured to provide a toner patch onto at least one of primary transfer portions. The toner patch is formed by developing an electrostatic latent image formed on at least one of the plurality of the image bearing members, and in the image forming mode a timing at which a trailing edge of the toner patch that passes through one of the plurality of the primary transfer portions reaches a secondary transfer portion is earlier than a timing at which the recording material reaches the secondary transfer portion.

Abstract: A control apparatus executes feedback control on an endless belt driven in a condition having a periodic disturbance to compensate an influence of the periodic disturbance. A disturbance other than the periodic disturbance is added to the belt during feedback control, and the control apparatus obtains phase angles of the periodic disturbance on timing when the other disturbance is added. The control apparatus obtains interpolation coefficients that respectively interpolate values of feedforward inputs in the case when the other disturbance is added at the time when phase angles of the periodic disturbance stored in a memory are a plurality of typical angles, and adds values obtained by adding values obtained by multiplying the interpolation coefficients respectively by the feedforward inputs to a control value of feedback control as a correction value.

Abstract: An image forming apparatus, which achieves reduced color registration time and real-time calibration of color position shift, and a control method for the same, is provided.

Abstract: An image forming apparatus comprises: an image forming unit configured to form an image quality adjustment pattern image on an image carrier to be driven at a predetermined speed; a detector configured to detect the image quality adjustment pattern image; an image quality adjustment controller configured to control image quality adjustment processing in accordance with a detection result by the detector; a speed change unit configured to change an image formation speed indicating a speed at which an image is formed, and an interval change unit configured to change an interval at which the detector acquires a detection result in accordance with a change amount between the image formation speed before changed by the speed change unit and the image formation speed after changed.

Abstract: An image processing apparatus includes a plurality of sensors arrange for reading different patches in a chart for color correction that includes a plurality of patches, a unit configured to acquire information on a color gamut, a color gamut division unit configured to divide the acquired color gamut into divided color gamuts, a determination unit configured to determine a plurality of patches to be used in a measurement of each divided color gamut, and a chart data generation unit configured to generate chart data of the chart in such a way as to allow one and the same sensor of the plurality of sensors to measure the plurality of patches of a respective divided color gamut determined by the determination unit.

Abstract: An image forming apparatus, including: an image forming unit configured to form toner images on an image bearing member and toner patterns for detecting a relative position of the toner images; a detection unit having a light emission unit and a light receiving unit configured to receive reflection light from the image bearing member and the toner patterns to output an analog signal; a conversion unit configured to convert the analog signal into a digital signal based on a threshold value; a correction unit configured to correct a misregistration between the toner images on a recording medium based on the digital signal; and a control unit configured to control, when values of the analog signal includes a value lower than the threshold value, light intensity of the light emission unit so that the values of the analog signal become higher than the threshold value.

Abstract: An image forming apparatus includes a photosensitive section driven to rotate, a light emission unit configured to emit light to form electrostatic latent images on the photosensitive section, a process section configured to form images on the photosensitive section, a detection unit configured to detect an output generated via the process section when an electrostatic latent image for correction passes through a position facing the process section, and a control unit configured to execute a correction of a position of an electrostatic latent image in image formation based on a detection result from the detection unit.

Abstract: An image forming apparatus that is capable of reducing velocity fluctuation due to variation of friction torque between an image bearing member and an intermediate transfer medium depending on a toner image. An exposure unit forms a latent image on the image bearing member rotated by a first drive unit. A development unit develops the latent image to form a toner image. A primary transfer unit transfers the toner image to an intermediate transfer medium rotated by a second drive unit. A secondary transfer unit transfers the toner image to a sheet. A control unit controls the drive units so that a peripheral velocity difference between the image bearing member and the intermediate transfer medium becomes a first value at starting, and controls so that the peripheral velocity difference becomes a second value larger than the first value when minute toner reaches the position of the primary transfer unit.

Abstract: A method and apparatus are provided for assessing the operation of a col or printing system (10) by measuring color plane mis-registration. The printing system (10) is caused to print a multi-sheet test job (26) with corresponding test points on each sheet distributed vertically and horizontally over the sheet. The test points comprise test markings for determining horizontal and vertical color plane mis-registration values. These test markings are measured by an imaging subsystem (30) to determine horizontal and vertical color plane mis-registration values (31) for the printing colors. The mis-registration values are then analyzed (33, 36) by a processing subsystem (32) to derive a plurality of mis-registration parameters that provide different respective views of mis-registration behaviour across the test sheets. An output is provided based on the mis-registration parameters.

Abstract: An image forming apparatus includes a developer image forming part, an intermediate transfer body, a primary transfer part, a drive mechanism to drive the intermediate transfer body, a medium carrying mechanism, and a drive controller to control an operation of the medium carrying mechanism. The developer image forming part forms a mark developer image. The developer image detection part detects the mark developer image moving on a carrying path that is from a primary transfer position to a secondary transfer position, and the drive controller controls carrying of a medium based on a detection result of the mark developer image by the developer detection part.

Abstract: Electrostatic image graduations inclined by a first angle in a main scanning direction are formed on a photosensitive drum and transferred to an intermediate transfer belt, and electrostatic image graduations inclined by a second angle in the main scanning direction are formed on the photosensitive drum and transferred to the intermediate transfer belt so as to overlap with the electrostatic image graduations inclined by the first angle. The electrostatic image graduations inclined by the first angle are detected by a conducting wire having a linear conductive member inclined by the first angle in the main scanning direction of the intermediate transfer belt. The electrostatic image graduations inclined by the second angle are detected by a conducting wire having a linear conductive member inclined by the second angle in the main scanning direction of the intermediate transfer belt.

Abstract: An image forming apparatus that is capable of forming an electrostatic latent image on the surface of a photosensitive member with high position accuracy even when the shaft of the photosensitive member is off-centered. In the apparatus, exposure devices form electrostatic latent images on respective photosensitive drums, and developing devices develop the electrostatic latent images. An intermediate transfer belt rotates in contact with the photosensitive drums. A rotary encoder detects a rotational speed of a drum shaft of each photosensitive drum. An amount of off-centering of the drum shaft is detected, and a correction coefficient for correcting positional displacement of electrostatic latent images is calculated. A control unit corrects timing of exposure using the calculated correction coefficient, and controls the exposure device to form the image on the photosensitive drum based on the corrected timing of exposure.

Abstract: A color registration method includes determining whether color registration is needed or not, if color registration is needed, setting an optimal amount of light of the registration sensor in a feedback manner, forming a predetermined mark for color registration correction on an image forming medium, and performing color registration correction with respect to the formed mark using the set optimal amount of light.