An image forming apparatus that enhances measurement accuracy of a pattern image and improves quality of a printed image. Light emitted from a light emission unit based on a first measurement condition is reflected from an image bearing member, and first information is generated based on a measurement result of the image bearing member. Second information is determined based on the first measurement condition, the first information, and a second measurement condition. Light is emitted based on the first measurement condition when a first measurement image is measured, and an image forming condition is generated based on a measurement result of the first measurement image and the first information. Light is emitted based on the second measurement condition when a second measurement image is measured, and the image forming condition is generated based on a measurement result of the second measurement image and the second information.

An image forming apparatus includes a photoreceptor, an exposure unit, a developing unit, and a control unit. The control unit sets the toner-layer-forming electric potential difference lower than an electric potential when forming the image on the print medium, forms a combined patch for calibration by the set toner-layer-forming electric potential difference for calibration, so as to adjust the developing-bias potential by measuring a print density of the formed combined patch. The combined patch includes a first patch and a plurality of second patches. The plurality of second patches have a width within a range of 0.2 mm to the predetermined value in the peripheral-velocity direction of the photoreceptor, extend with a length equal to or more than the predetermined value in the rotation-shaft direction of the photoreceptor, and are arranged at a predetermined interval in the peripheral-velocity direction of the photoreceptor.

An image formation apparatus that includes: first to third image formation units provided in this order in a traveling direction of a transfer target medium; a detector configured to detect first to third correction patterns formed on the transfer target medium by the first to third image formation units, respectively; and a control unit programed to control image misregistration correction based on a result of detection by the detector. The control unit causes the first and third image formation units to form the first and third correction patterns on the transfer target medium, respectively. When an amount of image misregistration between the first correction pattern and the third correction pattern is less than a predetermined value, the control unit neither causes the second image formation unit to form the second correction pattern, nor executes the image misregistration correction.

An image forming apparatus including an image forming unit that forms an image, an intermediate transfer member for a measuring image, a measurement unit that measures the measuring image, a conversion unit that converts a measurement result of the measuring image on a basis of a conversion condition, a determination unit that determines an image forming condition on a basis of the converted measurement result, and an update unit that updates the conversion condition while forming and measuring first measuring images, converting the measurement results of the first measuring images, determining a measuring image forming condition on a basis of the converted measurement results, forming second measuring images on a basis of the measuring image forming condition, obtaining measuring results of the second measuring images output from another measuring unit, and updating the conversion condition on a basis of the measurement results of the second measuring images.

The image processing apparatus of the present invention includes: an edge determination unit configured to detect an edge pixel to which a white pixel and a black pixel are adjacent in a first direction in an image in which each pixel is represented as a white pixel or a black pixel; a first detection unit configured to detect a number of consecutive pixels up to the edge pixel in the first direction in the image; a second detection unit configured to detect a number of consecutive pixels whose number of consecutive pixels in the first direction is larger than a first threshold in a second direction perpendicular to the first direction in the image; and a type determination unit configured to determine a type of the edge pixel based on detection results by the first detection unit and detection results by the second detection unit.

An image forming apparatus includes a plurality of image forming units configured to form images, an image bearing member, a detection unit configured to detect a pattern image formed on the image bearing member, the pattern image being used for detecting a color misregistration, a controller configured to control the plurality of image forming units to form a plurality of first pattern images, each having a different color, and control the detection unit to detect the color misregistration, and a storage unit configured to store data on the color misregistration, wherein the controller corrects an image forming position based on the stored data, and wherein in a case where an error is detected in the data, the controller controls the plurality of image forming units to form a plurality of second pattern images, different form the plurality of first pattern images, before the plurality of first pattern images is formed.

An image forming apparatus includes: a photoreceptor; an exposing unit comprising a light window and a light source; a developing unit; a transfer unit; a sensing unit comprising a sensor sensing a toner image of the transfer unit; and a shutter unit configured to open or close the light window and the sensor, wherein the shutter unit includes: a motor configured to have a driving shaft rotating in a first rotation direction and a second rotation direction; a first shutter part configured to open or close the light window by receiving driving force transferred from the driving shaft when the driving shaft rotates in the first and second rotation directions; and a second shutter part configured to open or close the sensor by receiving driving force transferred from the driving shaft when the driving shaft rotates in the second rotation direction.

An image forming apparatus includes an image carrier, an endless intermediate transfer belt, a primary transfer member, a secondary transfer member, a displacement amount detecting device, and a control unit. The displacement amount detecting device detects displacement amounts of a reference image in a main-scanning direction and a sub-scanning direction. The reference image is formed on the intermediate transfer belt. The displacement amount detecting device includes a density detecting sensor and a surface potential sensor. The density detecting sensor detects a print density of the reference image formed on the intermediate transfer belt. The surface potential sensor detects a surface potential of the reference image. The displacement amount detecting device simultaneously detects the identical reference image using the density detecting sensor and the surface potential sensor to ensure simultaneous detections of displacement amounts in the main-scanning direction and the sub-scanning direction.

In an image forming apparatus, an image forming unit forms a first image of a first color and a second image of a second color. An obtaining unit obtains information related to relative positions of a first measurement image, which is formed on an image carrier, of the first color and a second measurement image, which is formed on an image carrier, of the second color. A generation unit generates correlation data based on first information corresponding to a first image forming speed and second information corresponding to a second image forming speed. A controller, in a case where the image forming unit forms an image at the second image forming speed, corrects relative positions of the first image and the second image based on the first information in advance and the correlation data.

An image forming apparatus includes an image bearer, a toner image forming device, a plurality of image density detectors, and a controller. The plurality of image density detectors are disposed at predetermined intervals opposite the image bearer in a width direction of the image bearer. The controller causes the toner image forming device to form toner image patterns having an identical density at the plurality of positions on the image bearer and the plurality of image density detectors detects a density of the toner image patterns. Based on the detected density of the toner image patterns, the controller identifies multiple cyclic fluctuations of the density of the toner image patterns and adjusts an image forming condition based on the multiple cyclic fluctuations of the density of the toner image patterns to decrease an amplitude caused by the multiple cyclic fluctuations of the density of the toner image patterns.