An image forming apparatus includes a photosensitive member, an exposing unit exposes the photosensitive member to exposure light to form an electrostatic latent image, a developing unit develops the electrostatic latent image to form an image, an intermediate transfer member onto which the image on the photosensitive member is transferred, a measurement unit measures a measurement image on the intermediate transfer member, an adjustment unit adjusts gradation characteristics based on the measurement result of the measurement unit, and correction unit corrects intensity of the exposure light for each of a plurality of positions on the photosensitive member in a scanning direction. the correction unit corrects the intensity based on the correction amount with respect to the intensity corresponding to a predetermined position. the predetermine position corresponds to a position in the scanning direction, at which the measurement image is formed.

A spectral colorimetric apparatus comprises a light source, a spectral element, a light receiving element, a substrate on which the light receiving element is mounted, a housing and a pressing portion. The housing has a first side wall on which the substrate is fixed and a second side wall on which the spectral element is fixed. The pressing portion pinches the spectral element together with the second side wall and presses the spectral element to the second side wall.

An image forming apparatus includes an image forming unit, a transfer unit, and a controller. The transfer unit transfers a developer image formed by the image forming unit onto a transfer object. The controller controls each of the image forming unit and the transfer unit on a basis of printing data. The controller performs a printing control to cause a first printing operation and a second printing operation to be executed. The first printing operation forms a first developer image directed to an entire pixel region of a print image and transfers the first developer image onto the transfer object. The second printing operation forms a second developer image directed selectively to a high-gradation pixel region and transfers the second developer image onto the transfer object. The high-gradation pixel region is a pixel region, having a gradation value equal to or greater than a threshold, of the print image.

An image forming apparatus includes an image forming unit configured to form an image on a sheet, and an image reading unit configured to read an image from a sheet. The image forming apparatus outputs a sheet for which first processing was performed, and then output a sheet for which second processing for forming, by the image forming unit, an image of a predetermined pattern was performed. The image forming apparatus, based on a read image obtained by reading, by the image reading unit, the sheet for which the second processing was performed, obtain density correction data to be used for image formation by the image forming unit.

The image forming apparatus including: a controller controlling the image forming unit to form a test image, controlling the measurement unit to measure the test image on the image bearing member, and controlling the transfer unit to transfer the test image to the sheet; a reception unit receiving a user instruction; a second generation unit generating the conversion condition based on the user instruction and the measurement result of the test image, wherein the sample image includes a first sample image, a second sample image, and a third sample image, a color difference between the first and second sample images is smaller than a threshold value, a color difference between the second and third sample images is larger than the threshold value, density of the first sample image is higher than density of the second sample image and density of the third sample image.

An image forming apparatus that performs printing on continuous paper includes: an image forming unit that forms a toner image on an image carrier; a transfer unit that transfers the toner image on the image carrier to the continuous paper; a cleaning unit that removes toner on a surface of the image carrier downstream of a transfer position; and a control unit that performs toner consumption control to form the toner image on the image carrier, wherein the control unit can perform first control to form a first toner image on the image carrier and transfer the toner image to the continuous paper and second control to form a second toner image on the image carrier and remove toner by the cleaning unit without transferring the toner image to the continuous paper, and can select which of the first control and the second control is operated.

An image reading apparatus includes a first scanner provided in a housing, a conveyance unit, and a first calibration member. The conveyance unit is provided with a separation unit which separates the first calibration member upward from the first scanner. When the first calibration member is separated, the separation unit releases connection between the conveyance unit and the housing.

A digital printing machine color control method includes printing test images onto substrates, measuring substrates using a measuring device, comparing actual color values on substrates and saved color setpoints of test images using a controller, calculating differences between color setpoints and actual color values on substrates using the controller, upon exceeding acceptable deviations between color setpoints and actual color values, modifying solid or halftone values by a factor using the controller, repeating printing test images using test image halftone values corrected by the factor and measuring new actual color values using the measuring device, comparing actual color values newly printed using corrected values and saved color setpoints of test images using the controller, calculating differences between newly printed actual color values and saved color setpoints of test images using the controller, and printing print jobs if differences between new actual color values and color setpoints are below acceptable deviations.

An image forming system including: a reading unit configured to read, through a transparent member, an image on a first sheet conveyed by a conveyance unit; an opposed member provided opposite to the reading unit with respect to the transparent member, the first sheet passing through a gap between the opposed member and the transparent member; and at least one processor configured to control, based on the image read by the reading unit, a geometric characteristic of an image to be formed on a second sheet by an image forming portion, and control a changing unit to change the size of the gap to a first size when the thickness of the first sheet is a first thickness, and to a second size larger than the first size when the thickness of the first sheet is a second thickness larger than the first thickness.

Provided is an operation method of an image forming apparatus, the operation method including according to a color registration pattern that is a standard for determining an overlapping degree of respective color images of a plurality of colors to form a color image, transferring respective developers with the plurality of colors onto an intermediate transfer body; obtaining patch data of patches of the plurality of colors transferred according to the color registration pattern onto the intermediate transfer body. The patch data is compared with reference patch data corresponding to the color registration pattern, and based on a result of the comparing, noise data corresponding to noise is detected from the patch data. Standard patch data is obtained by removing the noise data from the patch data, and performing color registration based on the standard patch data.