Abstract: An image forming apparatus includes a conveyor, an image former, and a reading device. The conveyor conveys a medium in a conveyance direction. The image former forms an adjustment pattern on one side of the medium conveyed by the conveyor. The reading device downstream from the image former in the conveyance direction reads the adjustment pattern on the one side of the medium conveyed by the conveyor to generate read data. The adjustment pattern includes a first line segment and a second line segment that extend in directions different from each other and each are inclined with respect to the conveyance direction.

Abstract: An image forming apparatus includes a transfer processing portion, a detection processing portion, a correction processing portion, and an adjustment processing portion. The transfer processing portion transfers a detection toner image to outside an output area of a transfer object to which a toner image as an output target is transferred from an image-carrying member. The detection processing portion detects a density of the detection toner image that has been transferred to the transfer object by the transfer processing portion. The correction processing portion corrects a detection result of the detection processing portion based on an amount of toner transferred from the image-carrying member to the output area at a transfer timing when the detection toner image is transferred. The adjustment processing portion adjusts an image forming condition based on the detection result after correction by the correction processing portion.

Abstract: According to one embodiment, an image forming apparatus, includes a transfer belt onto which toner images are transferred during an image forming operation, and a sensor that emits light towards the transfer belt and detect an amount of light reflected by the transfer belt. A processor adjusts the amount of light emitted towards the transfer belt based on the detected amount of the reflected light, and stores, in a memory, light level information indicating an output level for the amount of light emitted towards the transfer belt by the sensor. The processor provides an instruction for outputting warning information when the light level information indicates the output level exceeds a threshold value.

Abstract: An image forming apparatus includes an image forming unit to form an image on a sheet, a conveyance unit to convey the sheet having the image formed thereon to a conveyance path and a reading unit to read a test image of a sheet conveyed to the conveyance path. In addition, a controller determines an adjustment value for adjusting a geometric characteristic of an image to be formed by the image forming unit based on a reading result of the reading unit, controls the image forming unit to form the test image, controls the reading unit to read the sheet having the test image formed thereon, and determines an adjustment value for adjusting a geometric characteristic of an image to be formed by the image forming unit based on a reading result of the reading unit.

Abstract: An image forming apparatus includes an image processor configured to perform image processing on image data based on a conversion condition to output converted image data; an image forming unit configured to form an image based on the converted image data output from the image processor, the image forming unit being controlled based on an image forming condition; and a controller configured to perform tone correction control, density evenness control, and total density control, which is a combination of the tone correction control and the density evenness control. In the tone correction control, the controller controls the image forming unit to form a test image on a sheet and obtains reading data related to the test image on the sheet.

Abstract: An example photodetector for detecting fluorescent toner includes a light emitting unit to emit light to a toner image, and a light receiving unit. The light receiving unit is to detect visible light reflected by the toner image, detect that the toner image includes the fluorescent toner based on the detection of the visible light, the visible light generated by the fluorescent toner and having a predetermined wavelength band different from a wavelength band of the emitted light, and output a signal corresponding to the detection of the fluorescent toner.

Abstract: A processor selects a target sheet from a plurality of predetermined sheet candidates in accordance with selection information that is input via an input device. Furthermore, the processor derives feature information regarding a noise point from a target image that is obtained through an image reading process performed on an output sheet output from an image forming device, the noise point being a dot-like noise image included in the target image. Furthermore, the processor determines whether or not the noise point is a dot-like sheet noise by applying the feature information to a determination algorithm that corresponds to the target sheet, the sheet noise being included in a sheet of the output sheet itself, the determination algorithm being one of a plurality of determination algorithms that respectively correspond to the plurality of sheet candidates.

Abstract: An apparatus outputs a first number of printed materials, reads the first number of printed materials output to acquire the first number of pieces of scanned image data, the first number being two or more, and controls a density of output printed materials by calculating variations in lightness values in the respective pieces of scanned image data included in scanned image data groups for each scanned image data group having as a unit a second number of pieces of scanned image data consecutive in order of being read among the first number of pieces of scanned image data, the second number being two or more, so that the printed materials are further output until all the variations in the lightness values are less than a first threshold value.

Abstract: An image forming apparatus includes an image forming device and circuitry. The image forming device forms an image on a recording material. The circuitry executes image quality adjustment control for adjusting image quality of the image formed by the image forming device. The circuitry is configured to selectively execute a first control mode for executing first image quality adjustment control and a second control mode including both the first image quality adjustment control and second image quality adjustment control. The circuitry executes only the second image quality adjustment control without executing the first image quality adjustment control in a case in which an execution skip condition for skipping the first image quality adjustment control is satisfied even when an execution condition for executing the second control mode is satisfied.

Abstract: An image forming apparatus includes an image carrier, an image forming unit, a transfer unit, a detector, a controller, an edge detector, and an abnormality detector. The detector detects developer attached to an image carrying surface at a position between a position where an image is formed and a position where the image is transferred. The controller controls the image forming unit such that a check image including an edge that extends in a direction intersecting the moving direction of the image carrying surface is formed in a region of the image carrying surface that passes through the detection position. The edge detector determines a position of the edge based on a detection status of the developer. The abnormality detector determines whether or not the image former is abnormal based on the position of the edge.

Abstract: A printing system is disclosed. The printing system includes at least one physical memory device to store ink model logic and one or more processors coupled with the at least one physical memory device to execute the ink model logic to generate first ink model parameter data for a first print medium based on first ink deposition data for a second print medium and first optical density measurement data for the first print medium.

Abstract: An image forming apparatus according to the present disclosure includes an image forming unit configured to form an image based on an image forming condition; a reading unit configured to read a test image on a sheet; a controller configured to: control the image forming unit to form the test image; obtain read data related to the test image output from the reading unit is formed; and update the image forming condition based on the read data. The controller operates in a first mode and a second mode, the first mode is a mode in which, the controller controls the image forming unit to form the image for the second sheet after the image forming condition is updated based on the reading data related to the test image.

Abstract: Example implementations relate to a system comprising a memory resource to store instructions executable by a processing resource. In some examples, the processing resource can execute instructions to perform a calibration procedure for a printing device including a printing component. Responsive to the calibration procedure, the processing resource can execute instructions to deliver a print material arranged in a compound shape to a calibration image on the printing component included in the printing device. Responsive to performing the delivery, the processing resource can execute instructions to measure a print material density of the print material on the calibration image of the compound shape during the calibration procedure via a density sensor included in the printing device. Furthermore, the processing resource can execute instructions to detect an abnormality in the print material density via signal analysis instructions and provide a notification regarding the print material density abnormality.

Abstract: An information processing apparatus that transmits print data and a print quality requirement to a control system that controls a printing apparatus to output a printed product satisfying required print quality, includes a reception unit configured to receive print data, a display control unit configured to display, on a display unit, a user interface that prompts a user to select a setting of print quality of the print data from among predetermined options, a generation unit configured to generate quality requirement data suitable for an option selected via the user interface, and a transmission unit configured to transmit, to the control system, the print data received by the reception unit and the quality requirement data generated by the generation unit, wherein the quality requirement data includes at least information indicating an acceptable range of a color difference between a standard color value and a colorimetric value of the printed product.

Abstract: An image forming apparatus includes an image forming unit configured to form an image on a sheet; a detection unit configured to detect a characteristic value of the sheet; a reading unit configured to optically read the sheet; and a control unit configured to perform determination processing for determining whether or not an image failure has occurred, by comparing a determination value acquired by causing the reading unit to read a non-image area of the sheet after an image has been formed on the sheet, with a reference determination value that is based on the characteristic value detected by the detection unit.

Abstract: An image forming apparatus includes: an image former that has an image carrier for supporting toner and prints a first image formed by exposure to the image carrier and a developing processing on continuous paper; and a hardware processor that controls the image former so as to print a second image on the continuous paper in a case where information on at least one of coverage and a printing distance of the first image formed by the image former meets a predetermined condition, wherein the hardware processor controls the image former so as to stop forming the second image on the image carrier before a toner amount of the second image per unit width at a predetermined position on the image carrier in a main scanning direction exceeds a threshold value affecting an exposure memory.

Abstract: Provided in one example is a printing system that has a printing zone with a platen (10), a drive, a suction force generator (18), a media advance sensor (26) to monitor movement of the medium through the printing zone in a medium advance direction, and a controller 28) to perform suction force calibration prior to printing. The suction force calibration includes controlling the drive to cause movement of the medium from an initial position at least partly through the printing zone while the suction force generator is controlled to generate at least one suction force level, determining a suction force level to be used during printing on the medium based on the output of the media advance sensor during the movement, and moving the medium back to the initial position.

Abstract: A controller of an image forming apparatus calculates a density difference between a measurement result of a toner image having the highest density formed on a photosensitive drum, which is obtained by an image density sensor, and the highest density of a density target. When the density difference falls within a predetermined range, the controller generates a tone correction table based on a density value of a first toner image formed with a plurality of densities including the highest density, and sets, based on the density difference, an exposure amount of laser light to be applied to the photosensitive drum by an exposure device. When the density difference falls out of the predetermined range, the controller generates the tone correction table based on a density value of a second toner image having a larger number of tone levels than that of the first toner image.

Abstract: An image forming apparatus of the present invention acquires first correction characteristics representing an output density for an input gradation value at a reference position in a main scanning direction and second correction characteristics representing a relative relationship of an output density at a predetermined position in the main scanning direction with the output density at the reference position in the main scanning direction. Then, the image forming apparatus corrects image data corresponding to the predetermined position in the main scanning direction based on the first correction characteristics and the second correction characteristics.

Abstract: An image formation system includes an image forming section that includes a belt and a roller. The image forming section forms, in a predetermined region of a sheet, either: a first patch image for performing tone correction of a toner image formed on the sheet, or a second patch image for monitoring color variation of the toner image formed on the sheet. The image forming system further includes a controller that controls the image forming section to form only one of the first patch image and the second patch image on any one sheet.

Abstract: Precise correction of a position of a toner image formed by an image forming station can be accomplished in a device using two-component developer. An electrostatic latent image for forming a color misregistration correction pattern for color misregistration correcting includes a first latent image pattern and a second latent image pattern at a position downstream of the first latent image pattern with respect to the moving direction of the electrostatic latent image.

Abstract: An image forming apparatus includes an image forming section and a controller. The image forming section transfers a toner image to a transfer target and includes plural developing units. The plural developing units include a first developing unit and at least one second developing unit. The plural developing units each include an image holding body and a developing roller. The image holding body has an outer circumferential surface and is rotated. The controller controls the image forming section so that, when a low-area-coverage portion and a high-area-coverage portion are disposed adjacent to each other and are formed by the first developing unit, a correction toner image is superposed on a boundary portion, where the low-area-coverage portion and the high-area-coverage portion are adjacent to each other, by the at least one second developing unit.

Abstract: Each light source has plural light emitting portions that are arranged at the different positions in at least a sub-scanning corresponding direction. A memory of a scanning control device stores correction data of the deviation of the beam pitch, correction data of the light amount difference, and correction data to decrease an influence of a reciprocity failure, for each combination of pixel forming light emitting portions. When a write signal is generated, a write control circuit of the scanning control device reads the correction data of the deviation of the beam pitch, the correction data of the light amount difference, and the correction data of the reciprocity failure according to the combination of the pixel forming light emitting portions from the memory, overlaps the read correction data to correction data of an APC, and outputs the overlapped data to a corresponding light source unit as light amount correction data.

Abstract: The data conversion unit of an image forming apparatus converts input image data into dot image data in which pixel values having gradation information are arranged in a matrix. A storage unit stores optical face tangle error information of each reflecting surface of a rotary polyhedron. An assignment unit assigns a number to each of the plurality of reflecting surfaces, specifies by which of the plurality of reflecting surfaces light emitted for each line of the dot image data is to be reflected and assigns the number of the reflecting surface to each line of the dot image data. A determination unit determines a light emission mode corresponding to the dot image data based on the optical face tangle error information and the number of the reflecting surface. An exposure control unit causes the light source to emit light in accordance with the determined emission mode.

Abstract: The image forming apparatus includes an image processing section that converts image data into pixel data, an image forming section that forms a toner image based on the pixel data, and a fixing section that fixes the toner image to the recording material by heating the recording material with the toner image formed thereon while conveying the recording material through a nip portion. The image processing section divides the pixel data corresponding to one recording material into a plurality of areas each formed of a predetermined number of pixels and acquires density information on some of the pixels within each of the areas as representative values. The fixing section carries out a process of fixing the toner image for which the density information has been acquired, under a fixing condition according to a maximum value of the representative values.

Abstract: An image forming apparatus includes an image bearing member, a sensor, a pattern forming section, and a position correction section. The position correction section specifies a first reference position and a second reference position. In a registration correction carried out when the image bearing member is in a time-elapsed state that is a state after the initial state, the position correction section specifies the position of each of the patch images of the respective colors included in the registration correction pattern formed by the pattern forming section at the time of registration correction and corrects based on the first reference position and the second reference position the correction amount to be applied to each image forming position specified in the registration correction currently being carried out.

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 a image forming unit; an image bearing member having a surface to bear a toner image and a test pattern; the surface having a first time-surface positioned identical to the test pattern, an integer multiple of revolutions upstream or downstream from the test pattern in a surface movement direction, and a second time-surface positioned different from the test pattern, shorter than one revolution upstream or downstream from the test pattern; a reflection light detector to detect the amount of light reflected from the test pattern and the first and second time-surfaces of the image bearing member; and a controller to control the image forming unit based on the detection result and determine whether to execute a first-surface control to detect at least the first time-surface or a second-surface control to detect only the second time-surface based on use condition of the image forming apparatus.

Abstract: In an image forming apparatus, an image forming device have an operating part and is configured to form an image at an image formation position on an imaging target. A control device is configured to control the image forming device to start performing an image forming process, determine an adjustment amount regarding the image formation position based on an operation amount of the operating part measured during a period of time from a first specified timing in a previous image forming process to a second specified timing in or before a current image forming process, and adjust, based on the adjustment amount, the image formation position where an image is formed pursuant to the current image forming process.

Abstract: An image forming apparatus in which a first toner image to be transferred to a recording medium through secondary transfer is formed on an intermediate transfer member and a second toner image not to be transferred to the recording medium through secondary transfer is formed on the intermediate transfer member after the first toner image has been formed. When the first toner image and the second toner image are formed, a position on the intermediate transfer member at which the second toner image is formed is controlled in accordance with a conveying direction length of the recording medium, to which the first toner image is transferred through secondary transfer, measured by using a detection unit.

Abstract: An image forming apparatus determines the amount of cleaning toner that is supplied to each of an intermediate transfer belt 31 and a secondary transfer belt 42 based on the number of sheets that have been fed with the pick-up side of the sheet opposed to the intermediate transfer belt 31 and the number of sheets that have been fed with the pick-up side of the sheet opposed to the secondary transfer belt 42; integrally forms on the intermediate transfer belt 31 cleaning toner images that are supplied to each of the intermediate transfer belt 31 and the secondary transfer belt 42; and switches the application and the stop application of the transfer voltage for transferring the toner image from the intermediate transfer belt 31 to the secondary transfer roller 41 at a timing corresponding to the determined amount of toner.

Abstract: Patch background data at each position of a background where a toner patch is formed in the second rotation is estimated from background measurement data at a plurality of positions detected in the first rotation and patch neighborhood measurement data detected in the second rotation at a plurality of positions where no toner patch is formed. Since the apparatus can execute density measurement before the light emission amount of a density sensor stabilizes, the time required for density measurement can be shorter than before. Since the change ratio of the light emission amount and the variation of the reflected light amount from the background are reflected on the patch background data, the density measurement accuracy can be improved.

Abstract: An image forming apparatus includes a preliminary toner image forming unit, a detecting unit, an adjusting unit, an obtaining unit, an activation grasping unit, a determining unit, and a preparation unit. The preliminary toner image forming unit causes an inactive image forming unit to form a preliminary toner image and causes the preliminary toner image to be transferred onto a transfer body. The detecting unit detects the preliminary toner image. The adjusting unit adjusts quality of a toner image. The obtaining unit obtains information regarding an image to be output. The activation grasping unit grasps an estimated activation timing. The determining unit determines whether a time period until the estimated activation timing has become equal to an image quality adjustment period. The preparation unit causes the preliminary toner image forming unit to transfer the preliminary toner image and causes the adjusting unit to adjust the quality of the toner image.

Abstract: An image forming apparatus, includes an image forming unit configured to form a reference pattern and a test pattern on a sheet, a measurement unit configured to detect the reference pattern formed on the sheet and to measure the test pattern formed on the sheet, and a control unit configured to control a measurement timing of the test pattern by the measurement unit according to a detection interval between two reference patterns detected by the measurement unit.

Abstract: An image forming apparatus includes an image carrier, an image forming unit, a density sensor, a gradation characteristic data generator, and a gradation corrector. The density sensor includes a low-pass filter to remove a high-frequency component of an output of the image density sensor. The gradation characteristic data generator forms a gradation correction pattern on the image carrier. The gradation correction pattern is a continuous gradation pattern including first and second patterns. The gradation characteristic data generator continuously detects image density of the continuous gradation pattern and background areas adjacent to the continuous gradation pattern to generate the gradation characteristic data. The gradation characteristic data generator forms a compensation pattern on the image carrier next to and continuous with a leading end of the first pattern in an image carrier rotational direction, to compensate for a response delay of the output of the density sensor due to the low-pass filter.

Abstract: An image forming apparatus is disclosed, including a light source; a drum; an optical scanning apparatus; and an endless belt. The image forming apparatus further includes a pattern forming unit which forms, on the endless belt along a conveying direction of the endless belt, a density fluctuation detecting pattern having a period; a density sensor which detects the density fluctuating detecting pattern and outputs a density signal including information on density fluctuations in the conveying direction of the endless belt; and a period detecting sensor which detects the period included in the density fluctuations.

Abstract: An image forming apparatus includes an image forming unit and a controller. The image forming unit forms an image on a continuous recording medium by transferring to the continuous recording medium a toner image obtained by developing a latent image formed on a photoreceptor. The controller controls the image forming unit such that an image based on image information is formed in a specific image area on the continuous recording medium, and at the same time, a specific image pattern is formed in a specific side area outside the image area on the continuous recording medium.

Abstract: An image forming unit forms an electrostatic latent image on an image carrier based on image data converted by a conversion unit, and the image is developed by a developing portion using toner. A replenishment control unit controls an amount of the toner with which the developing portion is replenished based on a toner density in the developing portion so that the toner density in the developing portion reaches a target density. A first determination unit determines a target density based on a result of a first measurement image being measured. A correction unit corrects conversion conditions based on a result of measuring a second measurement image and a correction condition. A second determination unit determines the correction condition based on the target density determined by the first determination unit.

Abstract: In an image forming apparatus, a high-density portion and a low-density portion are arranged close to each other such that a boundary between the high-density portion and the low-density portion intersects with the conveyance direction of a density detection patch. A controller compares, in the conveyance direction, temporal change in the density detection value at a boundary portion shifting from the high-density portion to the low-density portion, with temporal change in the density detection value at a boundary portion shifting from the low-density portion to the high-density portion, and sets a process condition based on a result of the comparison.

Abstract: An image forming apparatus has a detector that includes a toner density sensor arranged on the downstream side of a fixing section. When performing a control to determine an image forming condition of an image forming section based on the detection result of an image-adjusting pattern image obtained by the detector, the temperatures of a plurality of points in the axial direction of the fixing section are detected by a fixing temperature detector. Further, based on the temperature detection values obtained by the fixing temperature detector, a controller sets a detection area of the detector in a place where the fixing temperature is equal to a desired temperature, so that the detector detects the information about the image-adjusting pattern image at such place.

Abstract: An image forming unit forms a plurality of measurement images based on a plurality of process conditions. A measurement unit measures the density of each of the plurality of measurement images. A determination unit uses a first determination mode or a second determination mode. In the first determination mode, a process condition is determined from a first measurement result higher than target density and a second measurement result lower than the target density, from among a plurality of measurement results. In the second determination mode, the process condition is determined from measurement results lower than the target density.

Abstract: A signal processing apparatus includes a pulse signal producing section configured to produce image creating signals for image formation in response to image data by using an image processing clock corresponding to each pixel of the image data; a measuring section configured to measure a difference between an actual value and an ideal value of a signal width of the image creating signal at the time of measurement; and a processing section configured to correct the image data so as to cancel the difference at the time of an actual action.

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

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

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

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

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

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

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

Abstract: An image forming apparatus includes a sample pattern outputting part holding a sample pattern and supplying the held sample pattern to the image forming part, a selection part allowing a user to select one of the color sample images that configure the sample pattern, an image formation density adjustment amount holding part determining and holding image formation density adjustment amounts for increasing or decreasing image formation densities of the plurality of the colors, an image formation density adjusting part adjusting image formation densities of the plurality of the colors according to the image formation density adjustment amounts, a presenting part presenting to the user the image formation density adjustment amounts; and an image formation density adjustment amount modifying part receiving from the user modifications with respect to the image formation density adjustment amounts and updating the image formation density adjustment amounts.