A method for reducing artifacts in an electrophotographic printing system includes receiving a print job including image data for a set of pages. The electrophotographic printing system is used to print a block of pages from the print job to provide corresponding printed pages. The image data for the block of pages is analyzed to determine an average toner usage rate. If the determined average toner usage rate for the block of pages falls outside an acceptable toner usage rate range, image data for a compensation image and a number of compensation images are determined such that the average toner usage rate will be brought back into the acceptable toner usage rate range.

A method for reducing artifacts in an electrophotographic printing system includes receiving a print job including image data for a set of pages. The electrophotographic printing system is used to print a block of pages from the print job to provide corresponding printed pages. The image data for the block of pages is analyzed to determine an average toner usage rate. If the determined average toner usage rate for the block of pages falls outside an acceptable toner usage rate range, image data for a compensation image and a number of compensation images are determined such that the average toner usage rate will be brought back into the acceptable toner usage rate range.

A sheet discharging apparatus includes a sheet supporting portion supporting a sheet discharged out of a nip portion nipping the sheet and a guide portion provided opposed to an upper surface of the sheet fed out of the nip portion. The guide portion includes a fixed restricting portion restricting a rear end of the sheet with respect to a sheet discharging direction to moving upward away from an extension line in a sheet discharging direction of the nip portion after passing through the nip portion.

A sheet discharging apparatus includes a sheet supporting portion supporting a sheet discharged out of a nip portion nipping the sheet and a guide portion provided opposed to an upper surface of the sheet fed out of the nip portion. The guide portion includes a fixed restricting portion restricting a rear end of the sheet with respect to a sheet discharging direction to moving upward away from an extension line in a sheet discharging direction of the nip portion after passing through the nip portion.

An image forming apparatus comprises an image forming unit; a sensor that measures a measurement image; and a controller. The controller controls the image forming condition based on a measurement result of measuring a first measurement image; acquires information having a correlation to density variation of images to be formed by the image forming unit; controls the image forming condition based on the information; determines a first value regarding a density of an image to be formed, based on a measurement result of measuring a second measurement image; determines a second value regarding a density of the image to be formed by the image forming unit, based on the information; and controls a timing at which the image forming unit next forms the first measurement image, based on the first value and the second value.

An image forming apparatus is configured to obtain information indicating the capacity of a toner container. In accordance with the obtained information, a gamma table for correcting the luminance value of a printing-target image is determined and the luminance value of the image is corrected by using the determined gamma table.

An image forming apparatus is configured to obtain information indicating the capacity of a toner container. In accordance with the obtained information, a gamma table for correcting the luminance value of a printing-target image is determined and the luminance value of the image is corrected by using the determined gamma table.

An image forming apparatus configured to perform image formation using a component unit configured to be attachable to and detachable from a main body of the image forming apparatus is provided. The image forming apparatus includes: an access unit configured to access a storage device included in the component unit attached to the main body; and a control unit configured to control the access unit to read and update information stored in the storage device. The storage device includes a first area and a second area configured to store use information indicating a use state of the component unit, and updating of the use information stored in the first area by the control unit is configured such that updating only within a predetermined limit is permitted, and no limit is provided on updating of the use information stored in the second area.

An image forming apparatus configured to perform image formation using a component unit configured to be attachable to and detachable from a main body of the image forming apparatus is provided. The image forming apparatus includes: an access unit configured to access a storage device included in the component unit attached to the main body; and a control unit configured to control the access unit to read and update information stored in the storage device. The storage device includes a first area and a second area configured to store use information indicating a use state of the component unit, and updating of the use information stored in the first area by the control unit is configured such that updating only within a predetermined limit is permitted, and no limit is provided on updating of the use information stored in the second area.

An image forming device includes: an image former that executes image forming processing to form an image on a sheet; a primary controller; a secondary controller that controls the image former; a sensor that detects a state of the image former and transmits sensor data indicating the state to the secondary controller; a first transmission path between the secondary controller and the primary controller; and a second transmission path different from the first transmission path. The primary controller instructs the secondary controller to execute the image forming processing. Data related to the execution of the image forming processing is transmitted through the first transmission path. The secondary controller generates diagnostic data for failure diagnostics from the sensor data and life prediction relating to the image forming device and transmits the diagnostic data to the primary controller via the second transmission path.