Abstract: An image forming apparatus includes a conversion unit, an image bearing member, an image forming unit that forms an image on the image bearing member based on image data converted by the conversion unit, a measuring unit that measures a measurement image on the image bearing member, and a controller that controls the image forming unit to form a first measurement image, controls the measuring unit to measure the first measurement image, and generates a conversion condition based on a result of measurement of the first measurement image and a first feedback condition. In forming a chromatic color image after a predetermined number of monochrome images, the controller controls the image forming unit to form a second measurement image, controls the measuring unit to measure the second measurement image, and generates the conversion condition based on a result of measurement of the second measurement image and a second feedback condition.

Abstract: An image forming apparatus includes a conversion unit, a correction unit, an image forming unit, a measurement unit, first, second, and third generation units, a reading unit, an input unit, and a determination unit. Image data of a color components indicating one pixel based on a multidimensional table is converted and then corrected based on one-dimensional tables corresponding to the color components. An image is formed on a sheet based on the corrected image data. A measuring image formed on the sheet is measured. The multidimensional table can be generated based on a multi-color first measuring image. The one-dimensional table can be generated based on a second measuring image. A pattern image formed on the sheet is read. The one-dimensional table can be generated based on a pattern image for each of the color components on the sheet. Input user instructions indicated how the one-dimensional table is generated.

Abstract: An image forming apparatus includes an image forming unit configured to form measurement images used for density correction at different timings using pseudo halftone processing patterns and a density detection sensor for detecting density of an object to be detected on an optical path including the formed measurement image. Further, the image forming apparatus includes a shutter which is arranged in the optical path between a density detection sensor and the measurement image, changed, by a motor, to a closed state in which a detecting surface of the density detection sensor is closed when the measurement image is not detected, and changed to an open state in which the detecting surface of the density detection sensor is opened when the measurement image is detected. Further, the image forming apparatus includes a controller which changes an image forming condition based on the detection result of the density detection sensor.

Abstract: In an image forming apparatus in which an electrostatic image is formed on an electrophotographic photosensitive member using at least a process of a pseudo halftone formed by dots as a method of representing gradation, the electrophotographic photosensitive member is provided on a surface thereof with a plurality of recessed portions of 0.5 ?m more and 5 ?m or less in depth and 20 ?m or more and 80 ?m or less in longest diameter of an opening, when a square region of 500 ?m×500 ?m is arbitrarily extracted on the surface of the electrophotographic photosensitive member, in the square region, a total area of the recessed portions is 10000 ?m2 or more and 90000 ?m2 or less and a total area of a flat portion contained in a portion other than the recessed portion is 80000 ?m2 or more and 240000 ?m2 or less, and an arrangement (A) of the plurality of recessed portions is such an arrangement that an image quality lowering index (f) calculated by specific processing is 14% or less.

Abstract: An image forming apparatus includes a conversion unit configured to convert image data based on a conversion condition corresponding to a type of halftoning, an image processing unit configured to perform the halftoning, an image forming unit configured to form an image, a measurement unit configured to measure a measuring image, an acquisition unit configured to acquire information related to the number of the sheets on which the measuring images are to be formed, and a controller configured to generate a first conversion condition corresponding to first halftoning based on a result of a first measuring image on a first sheet, and generate a second conversion condition corresponding to second halftoning based on a result of a second measuring image on a second sheet, wherein, based on the information, the controller controls whether to control the number of the first sheets is larger than the number of the second sheets.

Abstract: An image forming apparatus includes a conversion unit configured to convert image data based on a conversion condition which corresponds to a type of halftone processing; an image processing unit configured to execute the halftone processing on the image data converted by the conversion unit, wherein the halftone processing includes first halftoning and second halftoning which is different from the first halftoning; and an image forming unit including a photoreceptor and an exposure unit configured to expose, based on the image data on which the halftone processing is executed by the image processing unit, the photoreceptor with light to form an electrostatic latent image on the photoreceptor.

Abstract: Temperature of a printing medium 110 is sufficiently decreased by stopping the printing medium 110 in a discharge path, conveying the printing medium at a low speed, switching a conveyance path, or the like. If the temperature of the printing medium 110 can be sufficiently decreased, the thermochromism phenomenon is suppressed. As a result, it is possible to provide an image forming apparatus capable of achieving highly accurate color matching and color stability.

Abstract: An image forming apparatus includes an image bearing member; a toner image forming device; an image transferring device; a transfer bias applying device; an image fixing device; a sensor for detecting light reflected by the toner image fixed on the sheet; a controller for controlling a leading portion bias applied to the leading portion of the sheet with respect to a sheet feeding direction and a central portion bias applied to the central area of the sheet. The controller forms first and second test images on the leading and central portions, respectively, and sets conditions of the leading and central portion biases on the basis of an output of the sensor, in correlation with a kind of the sheet. A toner deposition amount per unit area of the first test image is smaller than that of the second test image.

Abstract: The image forming apparatus includes: a measuring unit configured to measure reflected light from a test sheet, the measuring unit including a first sensor and a second sensor, a generation unit configured to generate information regarding a color of a plurality of measurement images based on a measurement result by the measuring unit; and a detection unit configured to detect a sensor that has output an abnormal measurement result in the measuring unit, based on the measurement result. The detection unit is further configured to detect a sensor that has output the abnormal measurement result, based on measurement results obtained by the measuring unit regarding reflected light from a predetermined region of the test sheet. The predetermined region corresponds to a region on which the plurality of measurement images are not formed.

Abstract: An image forming apparatus includes a conversion unit, an image forming unit, a controller, a conveyance unit, a measurement unit, a determination unit, an adjustment unit, and a generation unit. The conversion unit converts image data based on conversion condition. The image forming unit forms and fixes an image to a sheet. The controller controls to create first and second test sheets having respective reference and measurement images. The first and second test sheets are conveyed. The test images are measured. The determination unit determines first and second information regarding positions. The adjustment unit adjusts an image forming condition based the measured test images. The conversion condition is generated based on a second measurement result. A first reference image length in a direction in which the first test sheet is conveyed is longer than a second reference image length in a direction in which the second test sheet is conveyed.

Abstract: An image forming apparatus includes a conversion unit, a correction unit, an image forming unit, a measurement unit, first, second, and third generation units, a reading unit, an input unit, and a determination unit. Image data of a color components indicating one pixel based on a multidimensional table is converted and then corrected based on one-dimensional tables corresponding to the color components. An image is formed on a sheet based on the corrected image data. A measuring image formed on the sheet is measured. The multidimensional table can be generated based on a multi-color first measuring image. The one-dimensional table can be generated based on a second measuring image. A pattern image formed on the sheet is read. The one-dimensional table can be generated based on a pattern image for each of the color components on the sheet. Input user instructions indicated how the one-dimensional table is generated.

Abstract: An image forming apparatus comprises an image forming unit configured to form measurement images used for density correction at different timing using pseudo halftone processing pattern and a density detection sensor for detecting density of an object to be detected on an optical path including the measurement image formed. Further, the image forming apparatus comprises a shutter which is arranged on the optical path between a density detection sensor and the measurement image, changed, by a motor, to a closed state in which a detecting surface of the density detection sensor is closed when the measurement image is not detected and changed to an open state in which the detecting surface of the density detection sensor is opened when the measurement image is detected. Further, the image forming apparatus comprises a controller which changes an image forming condition based on detection result of the density detection sensor.

Abstract: An image forming apparatus includes a conversion unit, an image bearing member, an image forming unit that forms an image on the image bearing member based on image data converted by the conversion unit, a measuring unit that measures a measurement image on the image bearing member, and a controller that controls the image forming unit to form a first measurement image, controls the measuring unit to measure the first measurement image, and generates a conversion condition based on a result of measurement of the first measurement image and a first feedback condition. In forming a chromatic color image after a predetermined number of monochrome images, the controller controls the image forming unit to form a second measurement image, controls the measuring unit to measure the second measurement image, and generates the conversion condition based on a result of measurement of the second measurement image and a second feedback condition.

Abstract: Temperature of a printing medium 110 is sufficiently decreased by stopping the printing medium 110 in a discharge path, conveying the printing medium at a low speed, switching a conveyance path, or the like. If the temperature of the printing medium 110 can be sufficiently decreased, the thermochromism phenomenon is suppressed. As a result, it is possible to provide an image forming apparatus capable of achieving highly accurate color matching and color stability.

Abstract: An image forming apparatus including a conversion unit configured to convert image data based on a conversion condition which corresponds to a type of halftone processing; an image processing unit configured to execute the halftone processing to the image data converted by the conversion unit; wherein the halftone processing includes first halftoning and second halftoning which is different from the first halftoning, a photoreceptor; an exposure unit configured to expose the photoreceptor to form an electrostatic latent image an image forming unit including a photoreceptor, an exposure unit configured to expose, based on the image data that executed the halftone processing by the image processing unit, the photoreceptor with light to form an electrostatic latent image on the photoreceptor.

Abstract: An image forming apparatus includes a fixing unit configured to heat and fix a measurement image formed by an image forming unit to a sheet, a measurement unit arranged downstream of the fixing unit in a conveyance direction of the sheet and configured to measure color of the fixed measurement image, a conversion unit configured to convert a measurement result of the measurement unit into a measurement result at a predetermined temperature based on conversion setting information set in advance, a setting unit configured to set a mode for generating the conversion setting information, and a generation unit configured to generate the conversion setting information by causing the image forming unit to form the measurement image on the sheet, causing the fixing unit to fix the formed measurement image, and causing the measurement unit to repeatedly measure the fixed measurement image in response to setting of the mode.

Abstract: An image forming apparatus includes a feeding unit configured to feed a sheet, an image forming unit configured to form a measurement image on the sheet fed by the feeding unit, a measuring unit configured to measure the measurement image formed on the sheet by the image forming unit, and an adjustment unit configured to perform an adjustment operation on basis of a measurement result of the measurement image. In this case, the image forming unit forms the measurement image of a first side of the sheet and forms a setting aid image on a second side that is different from the first side, and the setting aid image shows information describing the direction of the sheet for setting in the feeding unit and information for prompting to set the sheet with the second side up in the feeding unit.

Abstract: In an image forming apparatus in which an electrostatic image is formed on an electrophotographic photosensitive member using at least a process of a pseudo halftone formed by dots as a method of representing gradation, the electrophotographic photosensitive member is provided on a surface thereof with a plurality of recessed portions of 0.5 ?m more and 5 ?m or less in depth and 20 ?m or more and 80 ?m or less in longest diameter of an opening, when a square region of 500 ?m×500 ?m is arbitrarily extracted on the surface of the electrophotographic photosensitive member, in the square region, a total area of the recessed portions is 10000 ?m2 or more and 90000 ?m2 or less and a total area of a flat portion contained in a portion other than the recessed portion is 80000 ?m2 or more and 240000 ?m2 or less, and an arrangement (A) of the plurality of recessed portions is such an arrangement that an image quality lowering index (f) calculated by specific processing is 14% or less.

Abstract: An image forming apparatus configures a normal transfer potential in a yellow primary transfer unit, and configures a transfer potential which does not cause any retransfer phenomenon of a yellow measurement image in image carriers located on the downstream side of the yellow primary transfer unit. When a color difference obtained from a reference density and a density of a measurement image on an intermediate transfer belt becomes equal to or larger than a prescribed value, the image forming apparatus determines that multinary-color density adjustment is required.

Abstract: An image forming apparatus includes; an exposure unit configured to perform, based on the image data, first exposure for a photosensitive member and second exposure for the photosensitive member exposed by the first exposure; a determination unit configured to determine a type of the image to be formed based on image data; and a control unit configured to control the exposure unit such that a difference in an exposure amount between the first exposure and the second exposure performed based on the image data when the type of the image is a character is larger than the difference in the exposure amount between the first exposure and the second exposure performed based on the image data when the type of the image is a picture.