Abstract: It is judged whether a sufficient time for executing all of three correction processings (a high density correction processing, a halftone correction processing, and a registration correction processing) can be secured or not. When the sufficient time cannot be secured, the high density correction processing as an essential correction processing is executed. A history of the halftone correction processing and a history of the registration correction processing are compared with each other. A date of latest execution of the halftone correction processing and a date of latest execution of the registration correction processing are compared with each other to judge whether or not the execution of the halftone correction processing is earlier, and the registration correction processing and the halftone correction processing are executed, respectively.

Abstract: An image forming apparatus generates a color image on a transfer belt by superimposing toner images of respective colors generated by image forming units, and transfers the color image onto a transfer medium. The image forming apparatus includes a correction pattern forming unit configured to form a correction pattern for correcting color misalignment on the transfer belt, a detection sensor configured to detect the correction pattern formed on the transfer belt by the correction pattern forming unit, and a correction control unit configured to control a width of the correction pattern in response to an output of the detection sensor produced by detecting the correction pattern.

Abstract: An image forming apparatus that forms a color image includes: a sensor that detects a density of an image formed on the transfer body; a density adjusting unit that forms a density test pattern on a transfer body and that adjusts process parameters such that a density of the density test pattern on the transfer body falls within a predetermined range of a reference density; and a gradation adjusting unit that forms a gradation test pattern on the transfer body and updates the gradation correction data such that a density for every gradation of the gradation test pattern on the transfer body falls within a predetermined range of a reference gradation density acquired and stored beforehand. The gradation adjusting unit updates the gradation correction data subsequently after the density adjusting unit adjusts the density of the density test pattern.

Abstract: A controlling section controls an image forming section to form a calibration pattern on an object. The calibration pattern includes a plurality of first patterns and a plurality of second patterns. Each of the first patterns includes at least one pair of marks. Each of the at least one pair of marks has different colors and overlaps with each other in a first direction. The first patterns have different degrees of overlapping from each other. Each of the second patterns is formed between one of the first patterns and another one of the first patterns in the moving direction. The detecting section detects the first and second patterns formed on the object. The correcting section corrects the image forming position in the first direction based on detection results of the first patterns, and corrects the image forming position in a second direction based on detection results of the second patterns.

Abstract: An image forming apparatus capable of keeping reproducibility and gradation in balance and outputting high-quality images. A primary electrostatic charger charges a photosensitive drum. A polygon scanner irradiates the drum with a laser beam to form an electrostatic latent image on the drum. A developing device develops the latent image into a toner image by applying a developing bias to the drum. In performing development by the developing device at a preset environmental contrast potential, a CPU determines a required contrast potential for obtaining a target maximum density. The CPU compares between the environmental contrast potential and the required contrast potential. Further, the CPU sets an upper limit value for a set contrast potential to be set to the developing device according to the result of the comparison, and sets an output level of the laser light to be output from the developing device.

Abstract: An image forming apparatus includes a control unit arranged to control an image forming unit so as to form images based on image information and to form maintenance images for maintaining the image forming unit. The control unit is arranged to control the image forming unit so as to form images on the second side of the sheet after forming images on the first side of the sheet, and so as to form the maintenance images on the second side at positions such that the maintenance images do not overlap with the images based on the image information formed on the first side.

Abstract: A color image forming apparatus includes a density sensor which detects the light reflecting characteristics of an unfixed toner image formed on an image carrier or a transfer material carrier, and a color sensor which detects the light reflecting characteristics of the fixed toner image formed on a transfer material. A test image is formed on the transfer material in accordance with the detection result of the density sensor, and a density control process of controlling image forming conditions is controlled to be executed in accordance with a detection result of detecting the test image by the color sensor.

Abstract: An image forming apparatus includes a controller for detecting the opening and closing of a shutter from the output from an optical sensor and controlling the opening and closing operation of the shutter based on the detected result. The controller determines that if the optical sensor is turned “ON” within a predetermined period of time from when the shutter begins opening, the operation of the shutter from the closed state to the open state is correctly detected. When no reflected light is detected by the optical sensor even after a predetermined time has elapsed, the controller determines that an anomaly has occurred and closes the shutter and repeat another detecting process.

Abstract: An image forming apparatus includes a control device that calculates a developing ability of the developing device based on a detection value detected by an optical detection device from the plural toner patches. The control device adjusts an image formation condition based on the calculated developing ability. A factor detection device is provided to detect a contributing factor that causes the developing ability to largely change after the last adjustment of the image formation condition. The control device controls image formation such that when the factor detection device does not detect the contribution factor and a developing ability calculated this time is different from that calculated last time (as to a part of the plural toner patches), the plural toner patches are formed based on a prescribed fixed image formation condition so that an attraction amount of toner attracting to the plural toner patches enter a prescribed range detectable for the optical detection device.

Abstract: A patch-pattern forming unit causes an image forming unit to form a patch pattern including a plurality of patches on a conveying member. A detecting unit detects the patch pattern formed on the conveying member. An adjusting unit adjusts an image forming condition of the image forming unit based on a result of detection by the detecting unit. The patch pattern has a length substantially equal to a distance between a patch-pattern start position, which is located at a space corresponding to at least a predetermined margin of a recording medium from a position of the image, and a position of the detecting unit.

Abstract: When a two-component developer stored in a developer tank has been replaced, an image forming apparatus performs (a) a first formation step of forming a reference toner image on a photoreceptor, (b) a detection step of detecting an amount of toner of the reference toner image, and (c) a supply step of supplying a predetermined amount of toner to the developer tank when the amount of toner detected in the detection step is less than a threshold. Moreover, the image forming apparatus repeats the first formation step, the detection step, and the supply step until the amount of toner detected in the detection step becomes not less than the threshold. This makes it possible to provide an image forming apparatus that is stable in image quality even immediately after replacement of developers.

Abstract: Systems and methods are described that facilitate calibrating a print engine using calibration data sets generated at at least two different L* levels to provide additional calibration measurement resolution toward the darker end of the grayscale spectrum. For instance a first, light grey (e.g., 70-90L*) calibration strip is scanned at a first resolution (e.g., 70-90L*) to generate a first calibration data set, and a second darker grey (e.g., 30-50L*) calibration strip is scanned at high resolution (e.g., 100L*) to generate a second calibration data set. The first calibration data set is used to calibrate the print engine for high L* values (e.g., 50-100) and the second calibration data set is used to calibrate the print engine for low L* values (e.g., 0-50). Alternatively, a single calibration strip having a known L* value can be scanned once at the known L* value and again at a higher L* value (e.g.

Abstract: An image processing apparatus includes an image forming unit, an image control unit, a sensor, and a correction unit. The image control unit controls the image forming unit to perform toner refresh which is an operation of outputting deteriorated toner at a high density, and controls the image forming unit to form a predetermined pattern. The sensor measures a density value of the formed image. The correction unit corrects the toner density for a high-density operation using the value measured from the image formed during the toner refresh and corrects the toner density for at least a low-density operation using the value measured from the predetermined pattern.

Abstract: An image forming apparatus includes: a cleaning blade provided on an intermediate transfer member to which a toner image formed on at least one image forming section is primary transferred and on a secondary transfer section which transfers the toner image transferred on the intermediate transfer member onto a transfer material, respectively, which cleans the toner image remained thereon, respectively; a bias power source which is electrically connected to the secondary transfer section; and a controller which causes the image forming section to form a patch toner image onto a non-image area on the image carrier corresponding to an area between adjoining two transfer materials, and causes the bias power source to conduct a power control in synchronization with a positional movement timing of the patch toner image, to supply selectively the patch toner image to the intermediate transfer member and the secondary transfer section.

Abstract: An image forming device includes an image forming unit forming an image on a sheet with an image forming property, a pattern forming unit forming a pattern on an object, a detection value determining unit determining a first detection value representing the image forming property of the image forming unit through detecting the pattern formed on the object by the pattern forming unit, a storage unit storing thereon the first detection value determined by the detection value determining unit, a correction value determining unit determining a correction value for correcting the image forming property with the first detection value stored on the storage unit and a second detection value that has previously stored on the storage unit, and a control unit controlling the image forming unit to form the image with the image forming property corrected based upon the correction value determined by the correction value determining unit.

Abstract: A tandem-type image forming apparatus includes a toner mark pattern forming unit configured to form a toner mark pattern; a sensor configured to detect the toner mark pattern; a first determining unit configured to determine presence or absence of color misregistration based on the detected result; and a color misregistration correcting unit configured to correct the color misregistration based on the determined result. The toner mark pattern includes paired toner marks disposed at different coordinates in the sub-scanning direction. One of the paired toner marks has their ends at different coordinates in the main scanning direction with respect to those of the other one. The first determining unit determines the presence or absence of the color misregistration in the main scanning direction based on the result of the detection of the paired toner marks.

Abstract: According to the invention, a method is provided for calculating a Fractional Area Coverage (FAC) for determining the density of toner to evaluate the effectiveness of a xerographic printing process. The amount of diffuse light being reflected at the specular angle is determined during densitometer calibration and subsequent specular sensor readings are corrected by subtracting a fraction of the diffuse sensor signal from the specular sensor signal. Also provided is a computer readable media having stored computer executable instructions, wherein the computer executable instructions, when executed by a computer, directs a computer to perform a method for calculating a FAC for determining the density of toner to evaluate the effectiveness of a xerographic printing process.

Abstract: A test pattern printed by a printer is assessed—without colorimetric equipment—to provide data used in recalibrating the printer. The assessment may be made by an unskilled operator, and can include discerning whether a particular pattern is visible in the printed test pattern, or whether a feature in the test pattern is relatively wider or narrower. From such assessment, needed changes to the printer's calibration data are inferred and implemented. A variety of other printer calibration techniques are disclosed. The technology is illustrated in the context of dye sublimation printers, and is particularly useful in optimizing printing of digitally-watermarked graphics.

Abstract: A method creates a printing image charge on a photoreceptor printing region of a photoreceptor within a printing apparatus and, simultaneously with the creating of the printing image charge, charges source patches on the photoreceptor outside the photoreceptor printing region. The method then transfers developer material from a donor roll to the photoreceptor. The source patches cause developer material to be removed from areas of the donor roll outside a donor roll printing region to create developer material-depleted regions. The method then reloads the donor roll with developer material using a magnetic brush and evaluates a reload function of the donor roll by characteristics of developer material on target patches with developer material in areas of the non-printing region of the photoreceptor adjacent the target patches. The method then alters the printing image charge to maintain the reload function within a predetermined range.

Abstract: Disclosed herein are a method and a printing apparatus implementing the method to minimize cross-process direction non-uniformities of color images in printed documents. When printing images on a photoreceptor, halftone test patches are generated for each color. A first halftone cell orientation (of dots) of the test patches and their corresponding color image data is determined. The halftone cells of test patches may be provided or rotated to a second orientation (or angle or degrees) for printing in an inter-document zone of the photoreceptor, while the first orientation of the color image data in the document image area of the photoreceptor remains the same. Errors or non-uniformities (e.g., with TRC correction) caused by sensor misreading of test patches at specific orientations in the cross-process direction are substantially eliminated, thereby providing output images without streaks or visible errors.

Abstract: When an input image is to be formed on a sheet conveyed to a transfer roller, the exposure section is controlled and deviation correction is performed to offset the image forming position across the width of the sheet in response to the result of detection by a deviation sensor. By contrast, when pattern images are to be formed on a sheet in response to the instruction of the main control section, the image forming control section does not perform deviation correction in the process of forming a pattern image.

Abstract: A full-color image forming apparatus for forming a toner image for each color on each image carrier, and for transferring the toner image onto a sheet, including: an image forming section for forming a correcting toner image for each color on a portion of an image carrier, wherein the portion corresponds to an interval between the successive sheets; and a control section for conducting a correcting operation of the toner image for each color, based on the correcting toner image which is formed by the image forming section, wherein, when the image forming section is possible to conduct an operation, if the image forming section is controlled to interrupt the correcting operation to use the correcting toner image yet to be formed, the control section controls the image forming section to form the residual correcting toner image, before the control section controls the image forming section to stop the operation.

Abstract: The present disclosure relates to a method, system and apparatus for calibrating an image forming device using a toner patch sensor which emits and detects light in at a given wavelength. A plurality of toner patches may be deposited onto a control surface, wherein the toner patches include a first toner patch including a first toner, a second toner patch including the first toner deposited over a second toner, and a third toner patch including the second toner. Signals indicative of the reflectivity of the plurality of toner patches and the control surface may be measured by emitting light of a given wavelength in the infrared spectrum and detecting the amount of incident light reflected from said plurality of toner patches and said control surface. The signals indicative of reflectivity may then be used to adjust operating parameters of the image forming device which may then control toner mass density.

Abstract: In the image forming apparatus, the partial image data for gradation adjustment is threshold conversion data of a partial image, the partial image is a part of a base pattern image with a predetermined size and does not contain any sides of the base pattern image, and the base pattern image is an image generated in an error diffusion method; and the patch image generator unit generates an image of a toner pattern by arranging the partial image of the partial image data repeatedly, and forms the toner pattern.

Abstract: An image forming apparatus is provided that forms an image using developers of different tone and the same hue. When forming images for measurement for density control, the apparatus performs density control by forming a greater number of density levels of an image for measurement developed using a light developer than the number of density levels of an image for measurement developed using a dark developer. Thus, even if the amount of applied light developer may fluctuate, the fluctuation can be compensated to prevent the occurrence of pseudo-contours that lower image quality.

Abstract: A positional misalignment correcting device includes a pattern forming unit that forms a correction pattern and a detecting unit that detects the correction pattern. The detecting unit includes one light emitting element and one light receiving element. The pattern forming unit forms the correction pattern on a transfer member such that a formation area in which the correction pattern is to be formed along a direction perpendicular to a conveying direction of the transfer member is smaller than a light-receiving area of the light receiving element.

Abstract: Patches of black and a mixture of color coloring materials are formed on a recording medium, and the chromaticities of the patches are detected (S11). Black tonality data serving as reference lightnesses corresponding to respective tonality data are acquired from pieces of lightness information contained in the detected chromaticities corresponding to the respective tonalities of the black patches. Pieces of black lightness information are corrected on the basis of the acquired black tonality data and the detection results of the black patches. Chromaticities corresponding to the black tonality data are defined as target chromaticities, and the mixture rates of the color coloring materials are corrected on the basis of the target chromaticities and the chromaticities obtained by detecting the patches using the color coloring materials.

Abstract: A light-transmissive transfer belt used in the system for determining toner mass amount and methods for making the belt. A system and method, using the transparent transfer belt, is capable of determining an amount of toner mass present on a toner application surface, and the real-time adjustment of parameters controlling xerographic transfer performance in the system. The system includes transmission-based sensors alone and in combination with reflective-based sensors.

Abstract: A control unit controls a device that executes an image forming process, compares changes of each toner adhesion amount in an image-density-detection pattern image when a developing-bias control condition is changed, with respect to a toner adhesion amount in an image-density-detection pattern image in a normal status, performs a malfunction-occurrence prediction process according to the degree of each change of the densities, and displays the result.

Abstract: An apparatus and method to update patch image formation frequency, in which an electrostatic latent image is formed on an image supporting object, and the electrostatic latent image is developed with a toner. The image formation apparatus includes a developing unit, a toner supply unit for supplying the toner to the developing unit, a patch image density detecting unit for detecting the density of a patch image formed on the image supporting object, a toner density detecting unit for detecting the density of the toner held in the developing unit, and a control unit that adjusts a generating interval of the patch image according to a detection result of the patch image density detecting unit.

Abstract: An image forming apparatus is provided that forms an image using developers of different tone and the same hue. When forming images for measurement for density control, the apparatus performs density control by forming a greater number of density levels of an image for measurement developed using a light developer than the number of density levels of an image for measurement developed using a dark developer. Thus, even if the amount of applied light developer may fluctuate, the fluctuation can be compensated to prevent the occurrence of pseudo-contours that lower image quality.

Abstract: A print control unit causes a secondary-transfer control unit to move a secondary transfer unit apart from an intermediate transfer member, causes a direct-transfer control unit to cause a black image forming unit to form a black image and transfer the black image onto a transfer sheet being conveyed along a conveying path, and causes a positional-alignment control unit to perform positional alignment.

Abstract: An image forming apparatus includes a plurality of image bearing members, each of which is configured to bear a portion of a pattern image including a plurality of reference images in a given form, an endless moving member facing the plurality of image bearing members and configured to receive the pattern image, an image detecting unit configured to detect the plurality of reference images, a rotational angle detecting unit configured to separately detect each image bearing member at a given rotational angle, and a controller configured to detect a speed deviation pattern for each revolution of each image bearing member. The controller is configured to detect the speed deviation pattern based on a result obtained from a phase component and a quadrature component of a frequency signal generated from the detection result obtained by the rotational angle detecting unit and a result of detecting the plurality of reference images in the pattern image transferred onto the endless moving member.

Abstract: An image forming apparatus includes an image bearing member; toner image formation means for forming a toner image on the image bearing member; removing means for removing deposited matter deposited on the image bearing member; detecting means for detecting a toner image to be detected, formed on the toner image formation means; control means for controlling a toner image forming condition of the toner image forming means in accordance with a result of detection of the toner image to be detected by the detecting means; the apparatus being operable in a mode in which the removing means operates to remove the deposition, and the detecting means operates to detect the toner image to be detected, executing means for executing an operation in the mode; and an operating portion for manually starting execution of the operation in the mode by the executing means.

Abstract: An image processing apparatus, according to the present invention can include a forming portion capable of forming a mark on a bearing member, a light projecting portion capable of irradiating a light onto the bearing member, a light receiving portion capable of receiving a reflection light from the bearing member and from the mark, and outputs a received light signal in accordance with the received light amount, a judging portion capable of judging the existence or non-existence of a mark on the bearing member based on the received light signal, an evaluating portion capable of evaluating a reflection state of the bearing member and an adjusting portion capable of adjusting a light receiving sensitivity of the light receiving portion at a time of a judgment by the judging portion, in accordance with an evaluation of the evaluating portion.

Abstract: A plurality of test patches each including a dark and light image which has density unevenness of a predetermined period in which the plurality of test patches are differentiated in phase difference relative to a phase of density unevenness induced by rotational unevenness occurring at a predetermined period in the motor for driving a photosensitive drum is formed. Then, density information of the plurality of test patches with is detected by a density sensor 41, and the phase of the density unevenness is obtained based on detection results (density information) of the plurality of test patches as well as based on a phase difference corresponding to a test patch whose density unevenness is a predetermined value in amplitude.

Abstract: An image-forming device includes an image-forming unit, a test image memory, a test image forming unit, a density measuring unit, an abnormality determining unit, a test image re-forming unit, and a density re-measuring unit. The image-forming unit forms an image on a recording medium based on inputted image data. The test image memory stores image data of test image used for calibrating density of image to be formed by the image-forming unit. The test image forming unit controls the image-forming unit to form the test image by reading image data for test image stored in the test image memory and outputting the image data to the image-forming unit. The density measuring unit measuring the density of the test image that the image-forming unit forms on the recording medium. The abnormality determining unit compares the density of test image measured by the density measuring unit with prescribed values pre-stored in association with the test images to determine whether the measured density is abnormal.

Abstract: In order to determine the image quality of an encoded image in consideration of the printing characteristic of an output apparatus (e.g., a copying machine and a printer), the image forming apparatus has an intermediate formation unit for forming dots that are based on dot data making up an encoded image on an intermediate transfer body, and a decision unit for deciding whether the encoded image should be formed on a sheet or not based on the density of the dots formed on the intermediate transfer body by the intermediate formation unit.

Abstract: A toner-image detecting sensor for detecting a toner image before being transferred onto a recording sheet and a fixed-image detecting sensor for detecting the toner image after being secondarily transferred and fixed on the recording sheet are arranged so that the positions of them in a main scanning corresponding direction are aligned. An image forming apparatus has a first image adjustment mode and a second image adjustment mode. In the first image adjustment mode, image adjustment is made on the basis of only a result of detection by the toner-image detecting sensor without transferring the test pattern onto the recording sheet. In the second image adjustment mode, the test pattern is transferred onto the recording sheet, and image adjustment is made on the basis of both a result of detection by the toner-image detecting sensor and a result of detection by the fixed-image detecting sensor.

Abstract: There is provided an image forming apparatus. The image forming apparatus, after controlling so as to develop the developer image representing the predetermined image formed a plurality of times in the same location on an image carrier by an exposing component, controls such that without performing exposure with the exposing component, the developer image, developed on the image carrier by the developing component applying a biasing voltage to the developer so as to adhere the developer to the image carrier including to the same location on the image carrier, is transferred to the transfer component and detects whether or not a ghost image is generated by comparing the density detected by a detecting component at a position of a transfer body corresponding to the same location of the image carrier to a reference density.

Abstract: An image forming apparatus includes: a plurality of image forming units as defined herein; an image carrier as defined herein; a first operation controlling unit as defined herein; a second operation controlling unit as defined herein; a density detecting sensor that detects densities of the images formed on the image carrier; a measuring unit that binarizes a density detection output of the image position deviation correction patterns formed on the image carrier, from the density detecting sensor, and that measures intervals between color patterns of the image position deviation correction patterns, based on the binarized output; and a position deviation correction controlling unit that performs a position deviation correcting control of, when the intervals measured by the measuring unit and of the color patterns in the image position deviation correction patterns are deviated from a predetermined range, correcting position deviation of the toner images formed by the image forming units.

Abstract: A controller takes in a detection signal indicating the surface electrical potential of a photoconductive drum (7) from a surface electrical potential sensor (step #1), and determines whether the surface electrical potential is smaller than the predetermined threshold value (step #2). As a result, when the controller (6) determines that the surface electrical potential is equal to or greater than the predetermined threshold value (NO in step #2), it uses the low print rate density patch to execute the density adjustments in accordance with the toner density and the developing bias associated with the density patch (step #3). When the controller (6) determines that the surface electrical potential is smaller than the predetermined threshold value (NO in step #1), it uses a high print rate density patch to execute the density adjustments in accordance with the toner density and the developing bias associated with the density patch (step #4).

Abstract: An image output controller is capable of directly or indirectly controlling a printer printing a color chart and a color measuring apparatus carrying out color measurement for the color chart. When color authentication is executed for an optionally set image, a process is carried out in relation to user's setting or automatic optimization including at least one of a printing position of the color chart, a layout of the color chart and a color value of the color chart. The printer is controlled according to a printing condition based on the user's setting or the automatic optimization so that the color chart is printed on a sheet of predetermined printing paper. The color measuring apparatus is controlled so as to carry out color measurement for the printed color chart.

Abstract: A technique that can contribute to improvement of analysis accuracy in analysis processing concerning an image forming apparatus is provided. An image forming apparatus that forms, on a sheet, a test pattern formed by a color obtained by mixing toners of plural colors, scans a test pattern image formed on the sheet with a color sensor, and performs predetermined image quality control processing on the basis of information scanned, the image forming apparatus including an analysis-information forming unit that forms predetermined information used for an analysis concerning the image forming apparatus on a sheet.

Abstract: Certain embodiments provide an image forming apparatus including: an image processing unit; a printer; a memory configured to store an adjustment value; an operation panel configured to receive a change for the adjustment value according to a user input; an adjuster configured to change, according to input information from the operation panel, the adjustment value from a first value to a second value; and a print controller configured to adjust a position of an image according to the second value and cause the printer to print a numerical value character string representing the second value together with a test pattern.

Abstract: An image formation device has an image formation section, a pattern image detection section and a registration correction section. The image formation section forms an image to be outputted and a pattern image on an image-bearing body, the pattern image is formed at a non-image creation region outside an image creation region at which the outputted image is formed. The pattern image detection section detects a position of the pattern image for detecting positional offset of the image. The registration correction section corrects the positional offset based on the detected position of the pattern image.

Abstract: A patch mark-forming unit forms a first patch mark at a first density on a surface. A light emitting unit emits an incident light onto the surface moving. The incident light reflected by the surface is divided into a mirror-reflected light and a diffusion-reflected light on the surface. A first detecting unit detects an amount of the diffusion-reflected light. The patch mark forming unit reforms a second patch mark at a second density weaker than the first density if the amount detected by the first detecting unit is larger than a threshold. A second detecting unit detects an amount of the mirror-reflected light reflected by the surface on which the second patch mark has been reformed. A position calculating unit calculates, based on the amount detected by the second detecting unit, a position at which an image should be formed. An image-forming unit forms an image at the position.

Abstract: An image forming apparatus appropriately adjusts an image forming conditions even if a halftone-processed image data is inputted. The image forming apparatus forms a patch image by applying a halftone process which is substantially equivalent to the halftone process which has been previously performed for the inputted image data. The image forming apparatus detects the density of the formed patch image and adjusts the image forming conditions according to the detected density.

Abstract: In an image forming apparatus, a control device recognizes expansion and contraction of a pattern image based on an output of an image detector. The control device calculates a driving motor velocity fluctuation cancellation pattern for driving a common drive source. The driving motor velocity fluctuation cancellation pattern creates a latent image expansion and contraction cancellation pattern capable of canceling the expansion and contraction of the pattern image detected by the image detecting device. A process of obtaining the cancellation patterns is executed except when a print job for forming the toner image is executed in accordance with image information. The control device controls the common drive source in accordance with the cancellation driving motor pattern.

Abstract: An image printing system includes a print engine and a sensing system. The print engine is configured to print a marking material image on a image bearing surface. The sensing system includes a plurality of illuminators, a modulator, a sensor, and a demodulator. Each illuminator is configured to simultaneously emit a light beam at the marking material image on the image bearing surface, thereby producing reflectance from the marking material image at least in a first direction. The modulator is configured to modulate an intensity characteristic of each of the light beams emitted by the illuminators such that each light beam has a different modulated waveform characteristic, where the waveform characteristic includes at least frequency. The sensor is configured to detect the reflectance from the plurality of light beams in the first direction and output a reflectance signal.