Abstract: A toner supplying method for supplying toner from a toner container to a developing part that causes toner to adhere to a latent image formed on a latent image carrying member and develops the latent image, includes detecting a toner amount in the developing part as being equal to or less than a predetermined toner amount value; forming a fog detecting image in a case where the toner amount in the developing part is equal to or less than the predetermined toner amount value, and detecting fog; and determining based on the detected fog whether to execute a toner ejecting process of ejecting the toner remaining in the developing part toward the latent image carrying member before supplying the toner to the developing part from the toner container.

Abstract: An image forming system including a first image forming apparatus and a second image forming apparatus. The first image forming apparatus forms an image on a first side of a recording medium and has a mark forming device to form a mark on the recording medium. The second image forming apparatus forms an image on a second side which is the obverse of the first side, and has a mark detector to detect the mark at a predetermined position in a conveyance path of the recording medium and a calculator to calculate an expansion and contraction ratio of the recording medium in a first direction and in a second direction perpendicular to the first direction based on the output of the mark detector.

Abstract: In an image forming apparatus, a controller performs development of toner patterns corresponding to a first halftoning method and a second halftoning method. One of the toner patterns contains first patch images for the first halftoning method, and another one contains second patch images for the second halftoning method. The controller performs development of only one out of both a first patch image (one of the first patch images) and a second patch image (one of the second patch images) if an absolute value of a difference between the number of dots in the first patch image and that in the second patch image is equal to or less than a predetermined value and an absolute value of a difference between the number of dot-level edges in the first patch image and that in the second patch image is equal to or less than a predetermined value.

Abstract: The present invention provides an image forming device including: plural image formation sections, a second exposure section, a transfer body, a reading section and an identification section. Each image formation section includes a control section that controls a first exposure section to form an identification image of a color represented by color information in accordance with an image formation instruction. The second exposure section performs exposure onto a charged image-bearing body and forms an electrostatic latent image. An image is formed at the transfer body. The reading section reads an image. The identification section outputs to the plurality of image formation sections an image formation instruction and, on the basis of a duration from the output until the identification image is read by the reading section, identifies a position of the image formation section forming the image of the color instructed by the image formation instruction.

Abstract: An image forming apparatus capable of ensuring a sufficient difference between amounts of light reflected from a base such as a transfer material and from a toner pattern in the detection of the toner pattern for registration correction control by a reflective optical sensor. The image forming apparatus includes a pattern generator for generating a toner pattern, a pattern detection sensor for detecting the toner pattern formed on the intermediate transfer belt, a pattern density decider for determining the density of the toner pattern that makes the amount of light received by the sensor in detection of the toner pattern equal to or less than a predetermined value.

Abstract: An image forming apparatus includes: an image carrier rotates in a predetermined direction; a correction image forming unit forming correction images on the image carrier in the predetermined direction; and a cleaning roller configured to clean the correction images on the image carrier. With respect to all values ranging from 1 to an arbitrary value n, a positive integer N which satisfies following expression for each of n exists: (T×N+L)/n?R/V?(T×(N+1)?L)/n, where R represents a circumferential length of the cleaning roller, L represents a length of each of the correction images in a moving direction of the image carrier, T represents a formation interval of the correction images in the moving direction of the image carrier, and V represents a ratio of a peripheral speed of the cleaning roller to a moving speed of the image carrier.

Abstract: A color image forming apparatus including a test pattern formation portion that forms test patterns of a plurality of colors in an image formation area in which images of the plurality of colors are formed on an image carrier and in an image non-formation area outside the image formation area on the image carrier, a detection portion that detects a shift of each of the test patterns of the plurality of colors formed in the image formation area and a shift of each of the test patterns of the plurality of colors formed in the image non-formation area, a computing portion that obtains, for each color, an offset value indicating an offset between the shift of the test pattern in the image non-formation area and the shift of the test pattern in the image formation area, and a storage portion that stores the offset value for each color.

Abstract: In a reflective optical sensor in an image forming apparatus, an output from each N number of light-receiving elements (N?3), obtained when M number of light-emitting elements (M?3) included in a light-emitting unit emit detecting light, is separated into an amount of specularly reflected light and an amount of diffusely reflected light. The toner density of a pattern, which is formed on a supporting member in the image forming apparatus, is calculated based on a sum of the amounts of specularly reflected light and a sum of the amounts of diffusely reflected light.

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 plurality of toner-image forming units that receive image data and form electrostatic latent images on image bearing members in accordance with the image data, and form toner images of respective colors by developing the electrostatic latent images, an intermediate transfer member onto which the toner images are transferred, a transfer unit that transfers the toner images of the respective colors onto the intermediate transfer member, a controller that performs transfer control for changing a transfer pressure applied when the transfer unit transfers the toner images onto the intermediate transfer member, and a misregistration detector that detects a difference of a transfer position of each of the toner images of the respective colors on the intermediate transfer member when the transfer control is performed by the controller.

Abstract: An image forming apparatus includes an image bearing member; an image forming portion for forming a toner image on the image bearing member, the image forming portion being capable of forming an image to be formed on a recording material and forming a control image for controlling an image density at a position adjacent to the image to be formed on the recording material; an intermediary transfer member rotatable while carrying the toner image transferred from the image bearing member; a transfer member for forming a transfer portion where the toner image is to be transferred from the intermediary transfer member onto the recording material; an electrostatic cleaning member for electrostatically removing the toner deposited on the transfer member; a density detecting portion, provided upstream of the transfer member with respect to a rotational direction of the intermediary transfer member, for detecting a density of the control image transferred on the intermediary transfer member; an adjusting portion for a

Abstract: To restrict a period velocity change of a photoconductor that is an immediate cause of a color registration error, a gap change of a color registration error detection pattern caused by a linear velocity change of the photoconductor is acquired and a linear velocity change of the photoconductor is reduced based on a relationship between the gap change and a velocity of a motor, whereby a reduced color registration error is accomplished.

Abstract: A method for color measurement of printing materials produced in printing machines includes a first color measurement instrument in the printing machine measuring the color of printing materials, a second color measurement instrument outside the printing machine measuring the color of printing materials produced in the printing machine and a computer communicating with the instruments, storing nominal color values and regulating color in inking units of printing units with the first instrument based on deviations from the stored nominal color values, determined on the printing materials in the printing machine. Printing materials produced by the printing machine are recorded by the second instrument. The second instrument records deviations from an original based on the color measured values determined on printing materials.

Abstract: An image forming apparatus may include an image carrier for carrying a toner image and a correcting toner image, a detection sensor for detecting density information of the correcting toner image; and a controller for causing the image forming unit to correct an image forming condition based on the density information detected by the detection unit to execute a stabilization control. The image forming unit may form a plurality of correcting toner images different in density over plural non-image areas. The controller may determine which mode is set between a processing speed priority mode and an image quality priority mode. The image forming unit may continuously form correcting toner images on the image carrier in a different manner depending on the mode. The detection sensor may detect density information of the correcting toner images. The image forming unit may finish a processing operation in the stabilization control under execution.

Abstract: In a method or system for processing a measurement signal to detect a property of a toner mark, the toner mark is generated with aid of an image generation device. The toner mark is detected with aid of a measurement unit in that sample values determined by the measurement unit at sample points in time are output as the measurement signal for detecting the property of the toner mark. A function is determined to describe at least one part of a signal curve of the measurement signal on a basis of at least one part of the output sample values. At least one extreme value of the function is determined.

Abstract: An image forming apparatus includes an image bearer that bears a toner image and a reference toner image, a toner amount detector that detects an amount of toner in the reference toner image, a detected toner amount correction device that corrects the amount of toner detected by the toner amount detector in accordance with a prescribed condition of a previous image formed just before formation of the reference toner image, and a controller that changes a condition of formation of subsequent toner images based on the corrected toner amount.

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 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 bearing member bearing an image; a transfer member having the image transferred thereto from the image bearing member; a correction-image-formation control unit that causes, on the transfer member, a bias correction image to be formed based on an uncorrected bias and a first parameter-correction image to be formed immediately behind the bias correction image based on the uncorrected bias and an uncorrected image-formation parameter; a bias correcting unit obtaining a corrected bias by correcting the uncorrected bias based on the bias correction image; a bias determining unit for determining whether the corrected bias is within a predetermined range defined based on the uncorrected bias; and a parameter correcting unit obtaining, if the corrected bias is within the predetermined range, a corrected image-formation parameter by correcting the uncorrected image-formation parameter based on the first parameter-correction image.

Abstract: A spectral colorimetric apparatus for detecting a color of an image of a subject, including: an illumination optical system illuminating the subject on a detection surface; a spectral optical system including a spectral element spectrally separating the beam diffused by the subject and a light receiving element array detecting a spectral intensity distribution; and a guiding optical system for guiding a beam diffused by the subject, wherein: the detection surface is parallel to a spectral plane including a principal ray of a beam entering the spectral optical system and a principal ray of a beam spectrally separated; the principal ray of the beam enters the spectral optical system within the spectral plane obliquely to a line joining a center of the light receiving element array with a surface vertex of the spectral element; and a light receiving surface of the light receiving element array is orthogonal to the spectral plane.

Abstract: An image forming apparatus includes an image carrier, an image forming member, a transferer, a toner image detector, and a controller. The transferer transfers the toner image from the image carrier directly or indirectly onto a recording medium transported by a surface moving member. The toner image detector detects a test toner image formed in a test toner image detection area located at an end portion of the surface moving member. The controller checks a length of the recording medium in a main scanning direction during continuous image formation, and forms the test toner image either in a space between recording media when the length of the recording medium exceeds a length of the surface moving member minus a length of the test toner image detection area in the main scanning direction or otherwise in parallel to the toner image transferred onto the recording medium.

Abstract: Provided is an image forming apparatus including: photosensitive drums; electrostatic latent image forming units; developing sleeves; patch detection sensors which detect image densities of the toner images formed by the electrostatic latent image forming units; and toner replenishment units which replenish the developing sleeves with the toner based on the detection results of the patch detection sensors. Further, controllers are provided to make a control such that the rotation speeds of the developing sleeves at the time of forming the reference toner image is higher than the rotation speeds of the developing sleeves at the time of forming a normal image.

Abstract: A printing device configured to print a diagnostic plot, the diagnostic plot including a cockle pattern, a main media advance pattern, and a secondary media advance pattern, wherein the cockle pattern, main media advance pattern, and secondary media advance pattern are for providing feedback and for adjusting printing characteristics associated with the printing device. A method of adjusting vacuum levels in a vacuum system of a printing device including generating a diagnostic plot on media; the diagnostic plot including a cockle pattern, a main media advance pattern, and a secondary media advance pattern, and accepting adjustments to printing parameters on the printing device based on printing defects displayed on the diagnostic plot.

Abstract: An apparatus includes: a drying unit to dry a printing medium on which an image was printed using an inkjet head; a humidification unit to humidify the printing medium that was dried by the drying unit so that the moisture content of the printing medium becomes the equilibrium state in the ambient environment; a colorimetric unit to perform colorimetry on the printing medium that was humidified by the humidification unit; and a calibration unit to calibrate printing properties on the basis of the result of colorimetry by the colorimetric unit.

Abstract: An image forming apparatus includes plural image holding members; an intermediate transfer material; a transfer unit that transfers the toner images onto a recording medium; a density control toner image creating unit that creates a density control toner image at a constant position on each of the image holding members; a density detection unit that detects density of the density control toner image transferred onto a non-image region; and a creation timing control unit that controls timing of creating the density control toner image to create the density control toner image in the non-image region of the intermediate transfer material at a position where a length obtained by integrally multiplying the length obtained by adding the non-image region to the image region along the moving direction of the intermediate transfer material becomes equal to a length obtained by integrally multiplying the circumferential length of the image holding member.

Abstract: An image forming apparatus includes: an image bearing member; a rotatable transfer member; a conveying portion for conveying a recording material; a controller for controlling an operation for forming a test image of a toner on the image bearing member in an interval region between consecutive output images of the toner; and a detecting portion for detecting the test image. The controller permits the formation of the test image, when next one of the consecutive output images is to be transferred onto a first side of the recording material, and the controller is capable of preventing the formation of the test image, when next one of the consecutive output images is to be transferred onto a second side of the recording material.

Abstract: An image forming apparatus including: an image forming section; and a control section allowing the image forming section to form a belt-shaped pattern on sheets in such a way that a formation starting position of the belt-shaped pattern is shifted for a distance, obtained by dividing a measurement-distance by a number of sheets to be used, in a main-scanning direction sheet by sheet; collecting, sheet by sheet, pieces of density information each of which indicates the density of the belt-shaped pattern at a measurement position of measurement positions; creating data in which the pieces of density information respectively correspond to the measurement positions arranged in the main-scanning direction on each of the sheets; and correcting density unevenness of image data in the main-scanning direction based on the created data, wherein the image forming section forms an image based on the image data of which the density unevenness is corrected.

Abstract: An image forming apparatus includes a first acquiring unit, a determination unit, a second acquiring unit, and a notifying unit. The first acquiring unit acquires first settable region information on a plane-shaped recording medium in other image forming apparatus. The first settable region information indicates a first settable region on which a registration mark is settable. The determination unit determines a first region based on the first settable region information. The first region is a region on which the registration mark is formable in a cascade printing system including the image forming apparatus and the other image forming apparatus. The second acquiring unit acquires second settable region information on the plane-shaped recording medium. The second settable region information indicates a second settable region on which the registration mark is formable in the plane-shaped recording medium. The notifying unit provides invalidity information indicating the registration mark is possible invalid.

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: A pattern forming unit forms a pattern for correcting a position shift of an image. A detecting unit detects the pattern. A measuring unit measures a time from a start of a control signal for controlling timing to start forming the image until a detection of the pattern. A control unit controls a position of forming the image based on the time measured by the measuring unit.

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 1x signals from sensors associated with the marking modules; and processing the image data in relation to the 1x signals to form banding profiles for multiple marking modules. Alternatively, the method may include: processing image data in relation to 1x 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: An embodiment of an image forming apparatus may include a photosensitive member, a development unit, a transfer member, a sensor, and a correcting unit. The development unit may form a toner image on the photosensitive member. The toner image member may be transferred onto the transfer member. The sensor may detect light from a surface of the transfer member. The correcting unit may correct a toner density in a first area of the transfer member after transfer of a toner image of a test pattern to the first area. The correcting unit may correct the toner density on the basis of a difference between an output value of the sensor from a second area before the transfer of the toner image of the test pattern and an output value of the sensor from the second area after the transfer of the toner image of the test pattern.

Abstract: By using a black-image forming device, an abrasive pattern is formed on a sheet conveying belt so that toner is input to a contact section where a cleaning blade is in contact with the sheet conveying belt. After the toner is input to the contact section where the cleaning blade is in contact with the sheet conveying belt and then the sheet conveying belt makes one or more revolutions, a process control is performed in which Y, M, and C toner patterns and B toner pattern are transferred onto the sheet conveying belt.

Abstract: Methods and systems herein provide for printing a plurality of variations of a test image utilizing different values of a print quality parameter for print quality analysis of a printer. A print quality parameter is selected that modifies a print quality of the printer when printing a test image. A range of values for the print quality parameter is defined to utilize when printing the test image. A plurality of variations of the test image are printed based on the range of values defined for the print quality parameter, which allows for an analysis of the print quality of the printer by the user.

Abstract: Line width of images marked by an image marking device is adjusted by reading a calibration patch marked by the marking device, and then adjusting one or more settings of the marking device, such as exposure intensity or cleaning field intensity, independent of the digital control of the tone reproduction curve so that the line width of subsequently marked images becomes closer to a target value. A digital control may be implemented to compensate for the impact of the modification of the one or more settings on the tone reproduction curve.

Abstract: A method for calibrating a position of a first register line in a register mark for a multi-color printing machine, said first register line consisting of a first color that does not offer sufficient contrast with respect to a printing material to allow detection above a determined threshold on a register sensor. A plurality of register marks, each consisting of at least one starting line, a background line and a first register line, is printed, said background line consisting of a second color which offers sufficient contrast with respect to the first color for detection above the specified threshold on the register sensor if the first register line is printed on the background line, and said background line having a width that is greater than the first register line, and said starting line, said background line and said first register line being printed with the use of the pre-determined control parameters, which normally cause the first register line to be printed on the background line.

Abstract: In a registration mark, when toners of plural colors are divided into two groups of a low-reflectance group having a relatively low spectral reflectance and a high-reflectance group having a relatively high spectral reflectance in accordance with high and low levels of spectral reflectances with respect to light emitted by an optical sensor, a toner pattern that gives information of a toner-image formation position of a toner-image forming unit using the toner that belongs to the low-reflectance group includes a first pattern in which the toner that belongs to the high-reflectance group is distributed without a gap in a moving direction of the transferred member, and second patterns formed with the toner used by the toner-image forming unit, the second patterns being arranged on both sides of the first pattern in the moving direction of the transferred member without a gap with respect to the first pattern.

Abstract: An image information detecting apparatus comprises a light source comprising a light emitting surface, an image bearing member, a light receiving unit comprising a light receiving surface, an illumination optical system for causing the light emitting surface and the image bearing member to have a conjugate relationship and illuminating a pattern for detecting the overlap positional deviation with a beam; and a light receiving optical system for causing the image bearing member and the light receiving surface to have a conjugate relationship and guiding the beam for detecting the overlap positional deviation to the light receiving unit, wherein a straight line portion of a conjugate image of the light emitting surface on the image bearing member and a straight line portion of a conjugate image of the light receiving surface on the image bearing member are parallel with each other.

Abstract: An image forming apparatus includes an image bearing body, a latent image forming section that forms a latent image on the image bearing body, a development section that develops the latent image using toner, a transfer section that transfers a toner image to a transferred body, a pressuring and contacting section that pressures and contact the transfer section against and with the image bearing body via the transferred body, a cleaning blade that removes residual toner, and a controller. The controller analyzes a print pattern of the image to be formed on the sheet. The controller controls the pressuring and contacting section to change a contact state between the image bearing body and the transferred body while adjusting an image patch formed in a domain corresponding to an inter-sheet portion between the sheet and the next sheet on the image bearing body according to an analysis result.

Abstract: An image forming apparatus includes a plurality of forming devices, a measuring device and a correcting device. In execution of a steady-deviation detection, the correcting device controls the forming devices to form a first pattern and detects a steady deviation amount of the image forming position on a basis of a measurement result of the first pattern. In execution of a varying-deviation detection, the correcting device controls at least one of the forming devices to form a second pattern and detects a varying deviation amount of the image forming position having a cycle on a basis of a measurement result of the second pattern. The correcting device determines necessity of executing the other one of the steady-deviation detection and the varying-deviation detection on the basis of the measurement result in the one of the steady-deviation detection and the varying-deviation detection.

Abstract: An image forming apparatus including a control section which detects an offset of a recording sheet being conveyed, the offset being in a main scanning direction perpendicular to a conveyance direction of the recording sheet; performs an offset regulation control which adjusts a main scanning direction image area signal in accordance with the offset; and forms a patch at a non-transfer area on an image carrier, wherein the control section performs a first control based on the offset of the recording sheet for the offset regulation control while a sub scanning direction image area signal is active for image forming on the recording sheet, and performs a second control for the offset regulation control while the image area signal in the sub scanning direction is inactive.

Abstract: An image forming apparatus includes an image forming unit that forms, on an image bearing member, an image for adjusting operations of the image forming apparatus, a container that contains toner removed from the image bearing member, and a controller that controls formation of the image for adjusting the operations of the image forming apparatus so that after an amount of toner contained in the container reaches a threshold value, an amount of toner removed from the image bearing member and to be contained in the container is reduced to less than before the amount of toner contained in the container reaches the threshold value.

Abstract: Methods, software, circuits and apparatuses for detecting a malfunction in an imaging device. The methods generally comprise orienting an image at an angle on an image detecting device; detecting the image; determining an error in the image; and correlating the error to a malfunction in the imaging device. Software instructions can be adapted to determine an orientation angle of an image; analyze the image to detect an error; and calculate a location of a malfunction in the imaging device. The circuits generally include a memory element; logic configured to calculate the orientation of an image; a processor configured to analyze the image and locate a fault; and logic configured to determine a location of the fault in the image and correlate the fault to a malfunction in an imaging device. The present invention advantageously provides a lower cost technique for detecting a malfunction in a high resolution imaging device.

Abstract: An image forming apparatus includes image carriers; an exposing unit that forms latent images on the image carriers; a developing unit that develops the latent images with toners of different colors from each other; a first transfer unit that forms a color image by superimposing and transferring the developed images onto a second image carrier; a test pattern forming unit that forms, on the image carriers, test patterns to be transferred onto the second image carrier; and test pattern detection units capable of detecting the test patterns transferred onto the second image carrier in different positions from each other in a main-scanning direction. The test pattern forming unit selectively switches, depending on a width of the test patterns in the main-scanning direction, whether to form each of the test patterns in a position detectable by the corresponding one of the test pattern detection units.

Abstract: An image forming apparatus includes a first reading device which reads a reference image formed on a sheet, a second reading device which reads a reference image formed on an image carrier, a control device which can execute a first control process for adjusting image formation conditions based on a density of the reference image acquired from a read result of the first reading device, and a second control process for adjusting the image formation conditions based on a density of the reference image acquired from a read result of the second reading device, wherein the control device executes the second control process before performing image formation based on the image data when the first control process has not been executed in a period from when mounting of the unit configuring the image forming device is detected to when image formation is performed.

Abstract: A diagnostic method for color stability in an image printing system includes printing a test pattern onto output media; measuring, during the printing of the test pattern, an image of the test pattern on an image transfer surface using one or more image transfer surface sensors to obtain one or more image transfer surface signals; measuring a printed image of the test pattern on the output media using a printed image sensor to obtain a printed image signal; calculating correlation functions for the one or more image transfer surface signals and the printed image signal; and analyzing the correlation functions for the one or more image transfer surface signals and the printed image signal to identify a subsystem in the image printing system that causes variations in color within the plurality of prints of the test pattern.

Abstract: An image forming device, configured to make image quality adjustment based on calibration data, includes a storage configured to store the calibration data for the image quality adjustment, an acquiring unit configured to acquire first image data, a converter configured to, when a predetermined condition is satisfied, convert the first image data acquired by the acquiring unit into second image data by placing, into the first image data, test pattern data for forming one or more test patterns, an image forming unit configured to form an image based on the second image data on an image-formed body thereof, a sensor configured to measure densities of the test patterns included in the image formed on the image-formed body, and a modifying unit configured to modify the calibration data stored on the storage based on the densities measured by the sensor.

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 and apparatus saves on toner cost and improves productivity for running registration and color process controls in a printer by making dual use of patches for both functions. That is, the small patches normally used only for registration measurement are also used for xerographic process control measurements, thereby eliminating the need for large patches and obtaining registration information and color control information at the same time. The dual use of small patches to measures both registration and color process control is made possible by periodically establishing correlation between the density of large density patches and the smaller registration patches.

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.