Abstract: An image forming device including a forming unit, an adhesion amount detector, a correction coefficient determiner, and a correction unit. The forming unit forms line images each having a different line width. The adhesion amount detector detects a toner adhesion amount for each of the line images. The correction coefficient determiner determines, according to the toner adhesion amounts detected for each line width, correction coefficients for a gradation value of the line images of each line width. The correction unit corrects a gradation value of a line image using a correction coefficient corresponding to the line width of the line image when forming the line image.

Abstract: An image forming device to and from which a developing unit in which a developer containing toner is filled is detachable and removable, comprises a hardware processor that: enables the developing unit to perform a stir operation of the developer filled in the developing unit as an initial operation of the developing unit; obtains a reference value of a toner density set in advance in time of a factory shipment of the developing unit at time the stir operation is performed; and compares a toner density received from the developing unit during the stir operation with the reference value to determine a stir condition of the developer.

Abstract: An image forming device to and from which a developing unit in which a developer containing toner is filled is detachable and removable, comprises a hardware processor that: enables the developing unit to perform a stir operation of the developer filled in the developing unit as an initial operation of the developing unit; obtains a reference value of a toner density set in advance in time of a factory shipment of the developing unit at time the stir operation is performed; and compares a toner density received from the developing unit during the stir operation with the reference value to determine a stir condition of the developer.

Abstract: An image forming device that forms a toner image on a surface of a photoreceptor, transfers the toner image to a recording material and outputs a printed recording material, includes: an intermediate transfer body that primarily transfers the toner image on the photoreceptor and secondarily transfers the toner image to the recording material; a cleaner that removes a toner left on the surface of the photoreceptor; a patch forming unit that forms a toner patch between two adjacent toner images when multiple toner images are continuously formed on the surface of the photoreceptor; a concentration detector that detects concentration of the toner patch primarily transferred to the intermediate transfer body from the photoreceptor; and a patch adjuster that adjusts toner amount used for forming the toner patch based on a result detected by the concentration detector.

Abstract: An image forming apparatus includes: an image forming part that forms a toner image on a recording medium; and a hardware processor that controls the image forming part, wherein the image forming part includes an image carrier, the hardware processor executes: a first adjustment process of adjusting the image forming part with use of a first image formation condition determined in accordance with a toner adhesion amount at a plurality of points in a first direction on the image carrier; and a second adjustment process of adjusting the image forming part with use of a second image formation condition determined in accordance with a toner adhesion amount at one point in a first direction on the image carrier, the image carrier rotates as a recording medium is conveyed, the first direction is a direction intersecting with a rotational direction of the image carrier.

Abstract: An image forming device that forms a toner image on a surface of a photoreceptor, transfers the toner image to a recording material and outputs, comprises: an intermediate transfer body that primarily transfers the toner image on the photoreceptor and secondarily transfers the toner image to the recording material; a cleaner that removes a toner left on the surface of the photoreceptor; a patch forming unit that forms a toner patch between two adjacent toner images when multiple toner images are continuously formed on the surface of the photoreceptor; a concentration detector that detects concentration of the toner patch primarily transferred to the intermediate transfer body from the photoreceptor; and a patch adjuster that adjusts toner amount used for forming the toner patch based on a result detected by the concentration detector.

Abstract: An image forming apparatus includes: an image forming part that forms a toner image on a recording medium; and a hardware processor that controls the image forming part, wherein the image forming part includes an image carrier, the hardware processor executes: a first adjustment process of adjusting the image forming part with use of a first image formation condition determined in accordance with a toner adhesion amount at a plurality of points in a first direction on the image carrier, and a second adjustment process of adjusting the image forming part with use of a second image formation condition determined in accordance with a toner adhesion amount at one point in a first direction on the image carrier, the image carrier rotates as a recording medium is conveyed, the first direction is a direction intersecting with a rotational direction of the image carrier.

Abstract: For each of N imaginary regions divided at predetermined intervals in the direction of the rotation shaft of a developer roller (12), the amount of toner consumed when an image is formed is previously calculated. Then, the same amount of toner as a toner consumption amount calculated for each imaginary region is supplied to a development device (2) earlier by a time in which the toner supplied from a toner hopper (5) is transported to each imaginary region than at the time of the development. Thus, it is possible to maintain a toner concentration within the development device within a predetermined range without the toner being dispersed and an image formation speed being reduced even if an image having a high print rate is formed.

Abstract: An image forming apparatus is provided which can execute an image stabilization operation and which includes: a determination portion that determines whether or not the image stabilization operation can be executed when a constituent member of the apparatus is replaced or when a consumable item is supplied; and an image stabilization control portion that executes the image stabilization operation when the determination portion determines that the image stabilization operation can he executed.

Abstract: For each of N imaginary regions divided at predetermined intervals in the direction of the rotation shaft of a developer roller (12), the amount of toner consumed when an image is formed is previously calculated. Then, the same amount of toner as a toner consumption amount calculated for each imaginary region is supplied to a development device (2) earlier by a time in which the toner supplied from a toner hopper (5) is transported to each imaginary region than at the time of the development. Thus, it is possible to maintain a toner concentration within the development device within a predetermined range without the toner being dispersed and an image formation speed being reduced even if an image having a high print rate is formed.

Abstract: An image forming apparatus has an image bearing member that moves at a specified speed; a toner pattern forming section for forming toner patterns of a specified type on the image bearing member under specified image forming conditions; a toner pattern detection member for detecting the toner patterns formed on the image bearing member; a toner amount varying section for varying a target amount of toner to adhere to the toner patterns; and a control section that calculates a toner adherence amount and a toner adherence position from detection results outputted from the toner pattern detection member and that performs image stabilization control to adjust the image forming conditions based on the calculation results. In the image stabilization control, the control section uses detection results of the same toner patterns both to calculate the toner adherence amount and to calculate the toner adherence position.

Abstract: A color image forming apparatus having photosensitive members; developing devices for developing electrostatic latent images formed on the photosensitive members into toner images with developers comprising toner and carriers; toner concentration sensors for detecting toner concentrations of the developers in the respective developing devices; a toner image bearing member for bearing the toner images temporarily; a toner adherence amount sensor for detecting toner adherence amounts of the toner images held on the image bearing member; and a controller for calculating, with respect to the developing devices, individual optimal developing bias voltage ranges within which a target toner adherence amount can be achieved while the toner concentrations of the developers are within a predetermined toner concentration range from a lower limit to an upper limit, so as to specify a common optimal developing bias voltage range that are commonly suitable for all the developing devices to achieve the target toner adherenc

Abstract: The present invention aims to provide an image forming apparatus and the like that perform a highly-accurate tone correction in a relatively short time and includes the following: a pattern former, with use of each image forming unit, on a sheet, forming tone patches in the main or sub scanning direction (41k,c,y,m) and aligning markers, which indicate positions of the tone patches, in the same direction as the tone patches (42k,c,y,m); a pattern reader reading the sheet with the tone patches and markers formed thereon; a coordinate determiner determining coordinates of the tone patches in the direction of the aligned tone patches based on the read markers (42k,c,y,m); a density determiner determining densities of the tone patches (41k,c,y,m) read based on the determined coordinates; and an updating part updating the tone correction table based on relationships between the determined densities and tone levels.

Abstract: An image forming apparatus performs dither processing on image data to form an image subjected to pseudo-halftone processing. The image forming apparatus includes a dither processing unit that performs dither processing on image data, and a dither pattern generation unit that generates a dither matrix for use in the dither processing, in accordance with an output gradation level. The dither matrix has a size of M×N pixels, and has a plurality of halftone dots arranged in a predetermined pattern in accordance with the output gradation level in order to represent a gradation of each color. The plurality of halftone dots are arranged in the dither matrix such that the halftone dots corresponding to at least two colors are substantially identical in color area ratio to each other in the dither matrix irrespective of a relative position with respective to the colors.

Abstract: A tandem-type color image forming apparatus forms a toner pattern and toner markers on an intermediate transfer member. Tone levels in the toner pattern vary in a sub scanning direction, and the toner markers which are a same color with the tone pattern each oppose, in a main scanning direction, a different one of the tone level portions in the toner pattern, each tone level portion representing a different one of the tone levels. Positions of the toner markers in the sub scanning direction are determined to detect densities in the toner pattern corresponding to the determined positions. Tone of image data is corrected in an image formation based on a relationship between the densities and the tone levels corresponding to the determined positions.

Abstract: An image forming device for forming an image on an image carrier using a different grayscale reproduction method for each of two or more different attributes contained in portions of the image. The image forming device forms a different standard pattern in one-to-one correspondence with each different attribute contained in the image portions, using a grayscale reproduction method used for reproducing image portions containing the attribute, detects density of each standard pattern formed by the standard pattern forming unit, sets, for each different attribute, a condition for correcting grayscale of the image portions containing the attribute, in accordance with the detected density, and corrects grayscale of the image portions in accordance with each condition set by the correction condition setting unit.

Abstract: A color image forming apparatus having photosensitive members; developing devices for developing electrostatic latent images formed on the photosensitive members into toner images with developers comprising toner and carriers; toner concentration sensors for detecting toner concentrations of the developers in the respective developing devices; a toner image bearing member for bearing the toner images temporarily; a toner adherence amount sensor for detecting toner adherence amounts of the toner images held on the image bearing member; and a controller for calculating, with respect to the developing devices, individual optimal developing bias voltage ranges within which a target toner adherence amount can be achieved while the toner concentrations of the developers are within a predetermined toner concentration range from a lower limit to an upper limit, so as to specify a common optimal developing bias voltage range that are commonly suitable for all the developing devices to achieve the target toner adherenc

Abstract: An image forming apparatus has an image bearing member that moves at a specified speed; a toner pattern forming section for forming toner patterns of a specified type on the image bearing member under specified image forming conditions; a toner pattern detection member for detecting the toner patterns formed on the image bearing member; a toner amount varying section for varying a target amount of toner to adhere to the toner patterns; and a control section that calculates a toner adherence amount and a toner adherence position from detection results outputted from the toner pattern detection member and that performs image stabilization control to adjust the image forming conditions based on the calculation results. In the image stabilization control, the control section uses detection results of the same toner patterns both to calculate the toner adherence amount and to calculate the toner adherence position.

Abstract: In an image forming apparatus of the present invention, a developing unit for magenta contains magenta-type toner for pseudo full-color image forming whose chromaticity point is shifted closer to yellow hue on a chromaticity diagram, in comparison with genuine-magenta toner for full-color image forming, and likewise, a developing unit for cyan contains cyan-type toner for the pseudo full-color image forming whose chromaticity point is shifted closer to yellow hue on the chromaticity diagram, in comparison with genuine-cyan toner for the full-color image forming.

Abstract: In a developer cartridge of toner and carrier, uneven distribution of the carrier at least in the vicinity of a replenishing port is eliminated regardless of the composition ratio between the carrier and the toner and the specific gravity of the carrier. Provided is a construction including a developer container in which a developer containing toner and carrier is received and which has a developing roller to supply the toner to an image carrier, a developer cartridge in which a replenishing developer containing the toner and the carrier is received and which has a replenishing port connected to the developer container to allow the developer container to be replenished with the developer via the replenishing port, and stirring means capable of stirring the developer located at least in the vicinity of the replenishing port in the developer cartridge.