An image forming apparatus, includes: a fixing portion configured to fix a toner image formed according to printing image data on a recording medium; an image processing portion configured to obtain reference image data according to the printing image data and a prescribed image pattern, and determines a target temperature on the basis of the reference image data, the reference image data being used as a reference for determining the target temperature at which the temperature of the fixing portion is maintained; and an electric power control portion configured to control electric power to be supplied to the fixing portion so that the temperature of the fixing portion is maintained at the target temperature.

An image forming apparatus includes a photosensitive member, a charging unit, an exposure unit, a developing unit, a transfer unit, and a controller configured to control the photosensitive member, the charging unit, the exposure unit, the developing unit, and the transfer unit to form a measurement image on the sheet, and acquire read data on the measurement image output from a reading device. The measurement image includes a first measurement image and a second measurement image. The controller forms the first measurement image based on a first image signal value and forms the second measurement image based on a second image signal value different from the first image signal value. The controller detects a streak included in the first measurement image or the second measurement image and determines an error based on a detection result.

The present invention pertains to an image forming apparatus that includes a latent image bearer, an exposure device, a detector, and processing circuitry. The exposure device exposes the latent image bearer to form a latent image based on image data. The detector detects density unevenness, in a main scanning direction, of a toner image obtained by developing the latent image. The processing circuitry corrects only an exposure amount of the exposure device based on the density unevenness to form an image portion with a higher gradation than a prescribed gradation, the processing circuitry further configured to correct the exposure amount and the image data based on the density unevenness in the main scanning direction detected by the detector to form an image portion with a gradation equal to or lower than the prescribed gradation.

An image forming apparatus includes circuitry, a reader, and an exposure device that drives lighting elements aligned in a main scanning direction to form a first test image. The circuitry acquires density of first sub-areas, into which the first test image is divided in the main scanning direction, and calculates first correction data based on density of each of the first sub-areas and average density of the first sub-areas, to correct light amounts of the lighting elements. The exposure device forms a second test image with the light amounts corrected. The circuitry acquires density of second sub-areas, into which the second test image is divided in the main scanning direction, and calculates second correction data based on density of a second sub-area adjacent to each of the second sub-areas, to further correct the light amounts. The second sub-areas are differently located from the first sub-areas in the main scanning direction.

An image forming apparatus includes an image forming device, an image position detector, and an image density detector. The image forming device forms an image on a surface of a recording medium. The image position detector detects a position of the image. The image density detector detects a density of the image. The image forming device forms a position detection image on a surface of a first recording medium. The image position detector detects a position of the position detection image on the surface of the first recording medium. The image forming device forms a density detection image on a second recording medium. The image density detector detects a density of the density detection image on the surface of the second recording medium.

An image forming apparatus, including: an image former; and a hardware processor which detects a density of an image formed by the image former, controls the image former to continuously perform image formation on a predetermined number of sheets and thereafter form a plurality of types of halftone test images on a sheet, determines whether an image defect is generated and determines a factor causing the image defect by analyzing densities of the plurality of types of test images, executes a recovery mode which is set for each of the factor when the image defect is determined to be generated, and controls the image former to form a charged test image which is formed by the charger charging the surface of the image carrier and an uncharged test image which is formed without charging of the surface of the image carrier by the charger.

An image forming apparatus includes an image forming section to form a correction pattern, a reading unit to read the pattern and generate first data, a color converter to convert the first data into second data, a memory to store density conversion data for a recording medium, a determiner to determine whether the memory contains the conversion data for the recording medium the pattern is formed, an acquisition unit to acquire spectral measured by an external colorimeter the memory does not contain the conversion data, a first density converter to convert the spectral data into density data, a density conversion data generator to correlate the second data and the density data and generate the conversion data, a second density converter to convert the second data into the density data using the conversion data, and a correction curve generator to generate correction curve data based on the density data.

An image forming apparatus including an image forming unit, a fixing unit, a reading unit, a reference member, and a controller is described. The image forming unit forms an image and a detection image on a sheet. The detection image is used for detecting geometric characteristics of an image to be formed on a sheet by the image forming unit. The fixing unit fixes the image and the detection image formed by the image forming unit on the sheet. The reading unit reads the detection image on the sheet. The controller adjusts geometric characteristics of the image to be formed on a sheet based on a reading result of the detection image by the reading unit, and controls the reading unit to read the reference member and executes shading correction based on a reading result of the reference member.

A 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 the 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.

In a case where a first mode in which a reader reads test patterns while sheets are fed to the reader by a document feeder is executed, an image forming apparatus forms a first test pattern on a first sheet and a second test pattern on a second sheet before the first test pattern on the first sheet placed on an original tray of the document feeder is read by the reader. In a case where a second mode in which the reader reads the test patterns on the sheets without feeding the sheets by the document feeder is executed, the apparatus forms the second test pattern after a reading of the first test pattern on the first sheet with the reader starts.