An image forming apparatus includes a platen on which an original is to be placed, a feeder configured to feed an original placed on a tray, a sensor configured to detect a sheet on the tray, a lamp provided to the feeder, a reader configured to read the original placed on the platen and to read the original conveyed by the feeder, an image forming unit configured to form an image on a sheet, and a controller. The controller is configured to control the image forming unit to form a first test image on a sheet, control the reader to read the first test image formed on the sheet placed on the platen, control a density of the image to be formed by the image forming unit based on a reading result of the first test image.

An image forming apparatus includes an image forming device and control circuitry to control the image forming device. The control circuitry is configured to: select control content to be executed based on a selection instruction from a user; set a set time of executing control of the control content selected, based on a setting instruction from the user; and execute, at the set time, the control of the control content selected.

An image forming apparatus includes a platen on which an original is to be placed, a feeder configured to feed an original placed on a tray, a sensor configured to detect a sheet on the tray, a lamp provided to the feeder, a reader configured to read the original placed on the platen and to read the original conveyed by the feeder, an image forming unit configured to form an image on a sheet, and a controller. The controller is configured to control the image forming unit to form a test image on a sheet, control the reader to read the test image formed on the sheet placed on the platen, control a density of the image to be formed by the image forming unit based on a reading result of the test image.

An image forming apparatus includes an image bearing member, an image forming portion, a transfer member, an applying portion, and an executing portion configured to execute an output operation for forming and outputting a chart formed on a recording material on which a plurality of test images are transferred by applying a plurality of voltages to the transfer member by the applying portion. The executing portion changes a change width per level of the test voltage so that the change width is a first change width in a case that a material of the recording material on which the chart is formed is a first material and so that the change width is a second change width different from the first change width in a case that the material of the recording material is a second material different from the first material.

An image forming apparatus includes an image forming unit for forming an image on a sheet, a reading unit for reading the image on the sheet and an inspection unit for inspecting whether an image formation failure has occurred by comparing the image read by the reading unit with a reference image registered in advance. The image forming apparatus executes the inspection with the inspection unit in a first inspection mode or a second inspection mode. The first inspection mode is a mode in which the inspection unit executes the inspection on all sheets on which the image is formed by the image forming unit. The second inspection mode is a mode in which the inspection unit executes the inspection on some of the sheets on which the image is formed by the image forming unit, and the inspection unit does not execute the inspection on the other sheets.

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 for forming an image on a sheet, a reading unit for reading the image on the sheet and an inspection unit for inspecting whether an image formation failure has occurred by comparing the image read by the reading unit with a reference image registered in advance. The image forming apparatus executes the inspection with the inspection unit in a first inspection mode or a second inspection mode. The first inspection mode is a mode in which the inspection unit executes the inspection on all sheets on which the image is formed by the image forming unit. The second inspection mode is a mode in which the inspection unit executes the inspection on some of the sheets on which the image is formed by the image forming unit, and the inspection unit does not execute the inspection on the other sheets.

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 platen on which an original is to be placed, a feeder configured to feed an original placed on a tray, a sensor configured to detect a sheet on the tray, a lamp provided to the feeder, a reader configured to read the original placed on the platen and to read the original conveyed by the feeder, an image forming unit configured to form an image on a sheet, and a controller. The controller is configured to control the image forming unit to form a first test image on a sheet, control the reader to read the first test image formed on the sheet placed on the platen, control a density of the image to be formed by the image forming unit based on a reading result of the first test image.