An image forming apparatus is provided. The image forming apparatus includes a sensor to detect a toner concentration, and a processor to control a rendering of image-forming data to form an image on an image forming medium, according to a level of toner concentration saving that is adjusted based on the detected toner concentration.

An image forming apparatus includes an intermediate transfer body, a plurality of image formation units arranged in a direction along which the intermediate transfer body moves. The plurality of image formation units includes a first image formation unit and at least one second image formation unit disposed downstream of the first image formation unit.

An apparatus converts image data based on a conversion condition, forms an image using a developer, measures the developer, and measures humidity. The apparatus determines a first density of an image when a mode of the apparatus changes from a power saving mode in which the apparatus cannot form an image to a normal mode in which the apparatus can form an image, from values measured, based on a first determination condition, determines a second density of an image when the apparatus has formed images on a predetermined number of sheets in the normal mode, from values measured, based on a second determination condition that is different from the first determination condition, and generates the conversion condition based on the first density and the second density.

An image forming apparatus includes an image forming device to form an image on an image bearer and circuitry configured to accept, from a user, an input of a density level selected from a plurality of different density levels and control an image forming condition under which the image forming device forms the image. The circuitry is configured to correct density unevenness of the image formed on the image bearer by the image forming device and correct the density unevenness of the image at the density level accepted. The density unevenness is unevenness appearing in a main scanning direction orthogonal to a direction of conveyance of the image bearer during image formation.

An image forming apparatus includes a memory and circuitry. The memory is configured to store a status of the image forming apparatus and a first detected density value obtained in a first tone correction based on a dither pattern. The circuitry is configured to calculate a difference between the status of the image forming apparatus upon the first tone correction and the status of the image forming apparatus upon a second tone correction following the first tone correction. The circuitry is further configured to calculate a correction value according to the difference in the status of the image forming apparatus, based on the first detected density value and a second detected density value obtained in the second tone correction based on a reference pattern.

An image forming apparatus includes an image bearer, an image forming section, an image density difference detector, and control circuitry. The image forming section is configured to form a gradation image pattern on a surface of the image bearer. The gradation image pattern includes gradation images having different image densities stepwise in a sub-scanning direction. The image density difference detector is configured to detect image density differences in a main scanning direction of the gradation images. The control circuitry is configured to execute an image density difference correction mode that corrects the image density differences in the main scanning direction based on detection results detected by the image density difference detector.

An image inspection system including: an image forming apparatus that forms an image on a sheet; an image reading apparatus that reads the image formed on the sheet through the image forming apparatus; and an image inspector that inspects the image read by the image reading apparatus. The image inspector includes a hardware processor that sets an edge portion of the sheet as an image inspection excluded area that is excluded from targets for inspection of the image.

A measurement apparatus includes a first conveyance path, a second conveyance path, a measuring portion, a third conveyance path and a sheet stacking portion. A sheet discharged out of an image forming apparatus is conveyed toward a downstream apparatus through the first conveyance path. The second conveyance path is branched from the first conveyance path, extended below the first conveyance path, and merged with the first conveyance path. The measuring portion is disposed on the second conveyance path. The third conveyance path is provided above the first conveyance path and is configured to convey the sheet from which a test image has been measured by the measuring portion in the second conveyance path. The sheet stacking portion is provided above the first conveyance path, and the sheet discharged out of the third conveyance path is stacked on the sheet stacking portion.

An image forming apparatus includes: an image bearing member; a developer carrying member to correspond to the image bearing member; drive portion to rotationally drive the developer carrying member; control unit to control the rotational drive by the drive portion, and detection portion to detect information from the toner patch. Modes for controlling, by control unit, the rotational drive of the drive portion include (i) a first mode which uses a first driving condition including a first peripheral speed ratio between the developer carrying member and the image bearing member and (ii) a second mode which uses a second driving condition including a second peripheral speed ratio which is higher than the first peripheral speed ratio. The control unit controls the image bearing member to form the toner patch for each of peripheral speed ratios and sets the second driving condition on the basis of the detected information.

Disclosed is an image forming apparatus including: an image forming unit which forms an image on a sheet; an abnormality detector which detects an image abnormality from the sheet on which the image is formed; and a hardware processor which, at the time of execution of a job, causes the image forming unit to form a test image for checking a detection level of the image abnormality by the abnormality detector, causes the abnormality detector to detect the image abnormality from the sheet on which the test image is formed, and performs an operation confirmation process of generating operation confirmation information of the abnormality detector on the basis of a detection result by the abnormality detector.