An image forming apparatus includes: a gear provided on a transmission path of driving force from a drive unit to a photoreceptive drum; a first acquisition processor to acquire a charged amount of toner; a formation processor to form a toner image for detection based on an image for detection with density according to the charged amount of toner acquired by the first acquisition processor among a plurality of images for detection having different color from each other for every time when a specific formation timing arrives; a second acquisition processor to acquire a variation width of density in the toner image for detection formed by the formation processor; and a determination processor to determine a failure timing of the gear based on the variation width for each formation timing corresponding to any one of the plurality of images for detection.

An image forming apparatus includes: an image forming unit configured to form an image on a sheet; a line sensor configured to read a sheet having test images formed thereon while the sheet having the test images formed thereon is conveyed; and a controller configured to: control the image forming unit to form the test images on the sheet; control the line sensor to read the sheet having the test images formed thereon; obtain read data related to the test images, the read data being output by the line sensor; and control, based on the read data, a geometric characteristic of an image to be formed on a sheet by the image forming unit, wherein the controller is configured to determine, in a reading area of the line sensor, whether dust is detected in a first area.

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.

Downtime relating to formation and detection of a detection image is reduced. An image forming apparatus includes a controller configured to calculate a first conversion unit to convert a gradation of input image data so that density output for the input image data becomes a first density output characteristic based on a first detection result of the detection image detected by a density sensor in a first mode. The controller generates a second conversion unit to convert the gradation of the input image data so that the density output for the input image data becomes a second density output characteristic in a second mode based on the detection result in the first mode and correction information, and further updates the correction information based on a second detection result of the detection image detected by the density sensor in the second mode and the first detection result.

An image forming apparatus includes: an image forming unit configured to form an image on a sheet; a line sensor configured to read a sheet having test images formed thereon while the sheet having the test images formed thereon is conveyed; and a controller configured to: control the image forming unit to form the test images on the sheet; control the line sensor to read the sheet having the test images formed thereon; obtain read data related to the test images, the read data being output by the line sensor; and control, based on the read data, a geometric characteristic of an image to be formed on a sheet by the image forming unit, wherein the controller is configured to determine, in a reading area of the line sensor, whether dust is detected in a first area.

Downtime relating to formation and detection of a detection image is reduced. An image forming apparatus includes a controller configured to calculate a first conversion unit to convert a gradation of input image data so that density output for the input image data becomes a first density output characteristic based on a first detection result of the detection image detected by a density sensor in a first mode. The controller generates a second conversion unit to convert the gradation of the input image data so that the density output for the input image data becomes a second density output characteristic in a second mode based on the detection result in the first mode and correction information, and further updates the correction information based on a second detection result of the detection image detected by the density sensor in the second mode and the first detection result.

An image forming apparatus includes a stack portion, a regulation portion, a detection unit, and a control unit. The regulation portion regulates a position of an edge of recording material stacked on the stack portion. The detection unit detects the position of the edge of the stacked and regulated recording material, and outputs a detection signal per the recording material edge detected position. Where the position of the recording material edge is detected, the control unit obtains a first width of the recording material stacked on the stack portion, calculates a second width of the recording material based on the detection signal output from the detection unit, and obtains a third width of the recording material by correcting a width of the recording material based on difference information between the second width of the recording material and the first width of the recording material.

Downtime relating to formation and detection of a detection image is reduced. An image forming apparatus includes a controller configured to calculate a first conversion unit to convert a gradation of input image data so that density output for the input image data becomes a first density output characteristic based on a first detection result of the detection image detected by a density sensor in a first mode. The controller generates a second conversion unit to convert the gradation of the input image data so that the density output for the input image data becomes a second density output characteristic in a second mode based on the detection result in the first mode and correction information, and further updates the correction information based on a second detection result of the detection image detected by the density sensor in the second mode and the first detection result.

An image forming apparatus with an image forming unit, including a photosensitive drum and an optical scanning device having a transparent window through which laser light that scans the photosensitive drum passes. The image forming apparatus further includes a cleaning mechanism configured to clean the transparent window and a controller unit configured to control the cleaning mechanism to clean the transparent window, wherein the controller unit controls the image forming unit to form an adjustment pattern on the photosensitive drum after the cleaning mechanism performs a cleaning operation for cleaning the transparent window.

An image forming apparatus includes a stack portion, a regulation portion, a detection unit, and a control unit. The regulation portion regulates a position of an edge of recording material stacked on the stack portion. The detection unit detects the position of the edge of the stacked and regulated recording material, and outputs a detection signal per the recording material edge detected position. Where the position of the recording material edge is detected, the control unit obtains a first width of the recording material stacked on the stack portion, calculates a second width of the recording material based on the detection signal output from the detection unit, and obtains a third width of the recording material by correcting a width of the recording material based on difference information between the second width of the recording material and the first width of the recording material.