An image forming apparatus includes a transfer belt, a forming unit, a detection unit, a correction unit, a drive system, a determination unit, and a notification unit. The forming unit forms an image-misregistration detection pattern of a plurality of colors on the belt. The correction unit corrects an image misregistration of an image of each color based on a detection result of the pattern. The determination unit detects a difference amount between a pattern interval of the pattern on the belt and a pattern interval serving as a reference value for each color and determines that an abnormality has occurred in a driving state of the drive system, in response to the difference amount equal to or greater than a threshold value. The notification unit notifies occurrence of the misregistration when the determination unit determines that the driving state is abnormal, based on the difference amount of any one color.

An image forming apparatus include an image forming device, an image bearer, a transferrer, a cleaner, and an adhesion amount detector. The image forming device forms, on the image bearer, a toner image to be transferred to a recording medium and a toner image pattern to be input to the cleaner without being transferred to the recording medium. The cleaner cleans the image bearer. The adhesion amount detector detects a toner adhesion amount of the toner image. The toner image pattern is a belt-shaped pattern elongated in an orthogonal direction orthogonal to a traveling direction of the image bearer and having a greater amount of toner input to a portion of the cleaner corresponding to a position of the adhesion amount detector in the orthogonal direction than that input to a portion of the cleaner not corresponding to the position of the adhesion amount detector in the orthogonal direction.

An image forming apparatus includes an image forming portion, a transfer unit, a power supply, and a reader. A test chart is formed by transferring test images to a recording material while applying test voltages from the power supply to the transfer unit. A transfer voltage to be applied to the transfer unit during transfer is set based on the read test images. A reference image is formed on the test chart. The reader reads the test chart by scanning the test chart from a first position to a second position that falls within the test images. The first position falls within a boundary of the recording material on which the test chart is formed and falls outside the test images. Based on the reference image, the result of the reader reading the test chart is obtained by scanning the test chart from the first position to the second position.

An apparatus comprising a first control unit that executes density correction processing on image data and generates an image signal, an image forming unit that forms an image on a recording medium on the basis of the image signal, and a second control unit that controls the image forming unit. The first control unit includes a specifying unit that transmits specifying information relating to the density correction processing to the second control unit. The second control unit includes an acquisition unit that acquires a parameter relating to the image forming apparatus, and an estimation unit that estimates a plurality of image densities corresponding to tone levels identified by the specifying information transmitted from the first control unit on the basis of the parameter acquired by the acquisition unit and transmits the plurality of image densities to the first control unit.

An image forming apparatus includes an image forming portion, a transfer portion, a power source, a reading portion, and a controller. The controller executes an output operation so that first test images do not overlap with second test images, respectively, on a first side and a second side of a recording material. On the basis of information on the second test voltage for transfer of the second test image, of the plurality of second test images, of which information on a density read by the reading portion coincides with a preset condition, the controller sets a transfer voltage for image transfer onto the second side in double-side image formation so that an absolute value of the transfer voltage set for the image transfer onto the second side in the double-side image formation is larger than an absolute value of the second test voltage coincided with the preset condition.

An image forming apparatus includes a plurality of image bearers, a plurality of rotation reference position detectors, and circuitry. Each of the plurality of rotation reference position detectors faces a corresponding image bearer of the plurality of image bearers to detect a rotation reference position of the corresponding image bearer. The circuitry performs, before an operation of rotating the plurality of image bearers, alignment control based on a result of detection performed by the plurality of rotation reference position detectors. The alignment control is control of driving of the plurality of image bearers to acquire a given relationship between the respective rotation reference positions of the plurality of image bearers. The circuitry determines whether to perform the alignment control based on whether the operation of rotating the plurality of image bearers is a function maintenance related operation.

An image forming apparatus includes a light scanning device, a developing portion, a control portion and a storage portion. The storage portion stores an evaluation chart. The evaluation chart includes a first evaluation pattern and a second evaluation pattern. The first evaluation pattern includes a first patch row. The first patch row is formed by arranging a plurality of first evaluation patches. The first evaluation patch includes a first dot row and a second dot row. The second evaluation pattern includes a second patch row. The second patch row is formed by arranging a plurality of second evaluation patches.

An image forming apparatus includes a light scanning device, a developing portion, a control portion and a storage portion. An evaluation chart includes a first evaluation pattern and a second evaluation pattern. The first evaluation pattern includes a first patch row. The first patch row is formed by arranging a plurality of first evaluation patches. The first evaluation patch includes a first dot row and a second dot row. The second evaluation pattern includes a second patch row. The second patch row is formed by arranging a plurality of second evaluation patches.

An image forming apparatus includes a light scanning device, a developing portion, a control portion and a storage portion. The storage portion stores an evaluation chart. The evaluation chart includes a first evaluation pattern and a second evaluation pattern. The first evaluation pattern includes a first patch row. The first patch row is formed by arranging a plurality of first evaluation patches. The first evaluation patch includes a first dot row, a second dot row and an auxiliary dot row. The second evaluation pattern includes a second patch row. The second patch row is formed by arranging a plurality of second evaluation patches.

An image forming apparatus includes an intermediate transfer member, a cleaning member, and an image forming unit having a developer carrier. During an image forming job, when a ratio of an amount of toner consumed to a distance that the developer carrier is rotationally driven is greater than a threshold value, the image forming unit forms a first toner supply image for supplying toner to the cleaning member in a predetermined period that is from a time at which a first toner image is transferred to the intermediate transfer member to a time at which a second toner image is transferred to the intermediate transfer member. When the ratio is less than the threshold value, the image forming unit forms a second toner supply image for supplying toner to the cleaning member in the predetermined period and having a density that is higher than a first toner supply image density.