An image forming apparatus, configured to operate in first and second modes of which color gamut is different from each other, includes an exposure unit configured to expose a photosensitive drum; a developing roller configured to form a toner image; a detection unit configured to detect density of the toner image transferred to an intermediate transfer member; and a controller configured to adjust the density based on a value of input image data. A dithering process for the controller's controlling of the exposure unit is different depending on whether the operation is in the first mode or the second mode, and in at least a part of the input image data, the density of the toner image formed by the dithering process in the first mode is higher than the density of the toner image formed by the dithering process in the second mode.

An image forming apparatus including a belt, a plurality of color information detectors, and a hardware processor. The belt is a belt on which images of a plurality of colors are formed to be laid on each other by a plurality of image formers that form the images of color components different from each other, the belt being colorless and transparent and having a transparency. The plurality of color information detectors are arranged on a front surface side and a back surface side of the belt, and detect, from the front and back surface sides, color information about a pattern image including two layers formed on the belt by two image formers among the plurality of image formers. The hardware processor calculates a color correction amount of an image formed by the two image formers based on detection results by the color information detectors.

An image forming apparatus includes a detection unit that optically detects a density of a reference toner image for density measurement formed on an image carrier. Either a first detection method for detecting the density of the reference toner image by receiving specularly reflected light reflected by the image carrier and the reference toner image for density measurement formed on the image carrier or a second detection method for detecting the density of the reference toner image by receiving diffusely reflected light from the image carrier and the reference toner image, is selected in accordance with color information of a toner, the color information being stored beforehand in a storage unit, and the density of the reference toner image is optically detected.

A printing apparatus includes: plural image forming units accommodating colorants of the same color; and a controller that forms an image of one color using the plural image forming units.

An image forming apparatus includes an image forming unit, a fixing unit, an image analyzer, and a temperature controller configured to control a temperature of the fixing unit in accordance to a target temperature. The image analyzer is configured to analyze image data for forming the toner image by the image forming unit, to evaluate a continuity of pixels of an image contained in the image data. The temperature controller is configured to change the target temperature based on analysis results of the image analyzer such that a value of the target temperature in a case where the image data contains an image with a continuity of pixels equal to or smaller than a predetermined value is higher than a value of the target temperature in a case where the image data contains no image with a continuity of pixels equal to or smaller than the predetermined value.

An image forming apparatus includes: a control unit configured to acquire base information by making a reading unit read a surface of the recording material with all image forming units set in a non-forming state, acquire first determination information by making the reading unit read a non-image region of the recording material with only a first image forming unit set in a forming state, and acquire second determination information by making the reading unit read the non-image region with all image forming units set in the forming state or with only all second image forming units set in the forming state. The control unit is further configured to determine a color of a toner adhered to the non-image region based on the base information, the first determination information, and the second determination information.

An image forming apparatus, configured to operate in first and second modes of which color gamut is different from each other, includes an exposure unit configured to expose a photosensitive drum; a developing roller configured to form a toner image; a detection unit configured to detect density of the toner image transferred to an intermediate transfer member; and a controller configured to adjust the density based on a value of input image data. A dithering process for the controller's controlling of the exposure unit is different depending on whether the operation is in the first mode or the second mode, and in at least a part of the input image data, the density of the toner image formed by the dithering process in the first mode is higher than the density of the toner image formed by the dithering process in the second mode.

An image forming apparatus includes: a control unit configured to acquire base information by making a reading unit read a surface of the recording material with all image forming units set in a non-forming state, acquire first determination information by making the reading unit read a non-image region of the recording material with only a first image forming unit set in a forming state, and acquire second determination information by making the reading unit read the non-image region with all image forming units set in the forming state or with only all second image forming units set in the forming state. The control unit is further configured to determine a color of a toner adhered to the non-image region based on the base information, the first determination information, and the second determination information.

There is provided a method for controlling an electrophotographic apparatus including forming a first measurement image by performing first halftone processing on image data, forming a second measurement image by performing second halftone processing different from the first halftone processing on the image data, measuring densities of the first measurement image and the second measurement image, calculating a density difference between each of densities of the measurement images, determining whether the density difference satisfies a predetermined reference value, and applying a surface treatment on an electrophotographic photosensitive member if the density difference does not satisfy the reference value, during a non-image formation period.

An image forming apparatus includes a developing roller configured to develop an electrostatic latent image on a photosensitive drum to form a toner image; a belt onto which the toner image is transferred; a detection unit configured to detect a density of an image for detection formed on the belt; and a controller configured to perform hue adjustment based on a detection result of the detection unit. The image forming apparatus performs image formation in a second mode using a color gamut different from a color gamut in a first mode, and the controller obtains a lookup table, which indicates a correlation between image data to be used and input image data in the second mode, based on the detection result in the first mode and a correlation of density between the first mode and the second mode.