Abstract: There is provided a developing device for developing an electrostatic latent image formed on a photoreceptor with a developer to form an image, including: a developing container that contains the developer; and a developing roller that faces the photoreceptor, is arranged adjacent to the developing container, and conveys the developer contained in the developing container to the photoreceptor, wherein the developing roller includes a magnetic pole forming part to be formed with a plurality of magnetic poles along a circumferential direction of the developing roller, at least a catch pole is formed as one of the plurality of magnetic poles, and in the catch pole, an amount of a total magnetic charge in an axial direction of the developing roller is kept constant, and a part of magnetic flux density distribution is different from another part of magnetic flux density distribution along the axial direction of the developing roller.

Abstract: A developing device includes a hardware processor that performs control in which a developer circulation state is switched between a first state and a second state depending on states of the developer in the first and the second regions. The first state is a state in which a developer circulation path is formed in each of the first and the second regions, and the second state is a state in which a single developer circulation path is formed all through the first and the second regions.

Abstract: A developing apparatus includes: a developer carrying member carrying a developer; a plurality of developer feeders accommodating the developer carried by the developer carrying member and being arranged in an axial direction of the developer carrying member; and a collecting part that collects the developer from the developer carrying member and feeds the developer to a second developer feeder different from a first developer feeder located at a position where the developer is collected from the developer carrying member in the axial direction, among the plurality of developer feeders.

Abstract: A system for predicting occurrence of a defective image includes: an input device configured to input image data into an image forming apparatus; and a hardware processor configured to analyze a spatial frequency of gradient distribution of an image in accordance with a size of a density irregularity specific to the image forming apparatus with respect to the input image data and to calculate a probability of a conspicuous density irregularity of the size in regard to the image formed by the image forming apparatus based on the image data with reference to an index of correlation between an analysis result and an evaluation value of the density irregularity.

Abstract: A developing device includes: a plurality of development sections arranged in an axis direction of a developer bearing member; a communication section disposed at a boundary of adjacent two development sections of the development sections, and configured to communicate between the two development sections; and a control section configured to perform an operation of moving the developer between the two development sections through the communication section to equalize degradation states of the developer in the two development sections.

Abstract: A developing device includes a developing agent carrier body that carries a developing agent; a supplier that has a plurality of movement areas for moving the developing agent and that supplies the developing agent to the developing agent carrier body; a confluence path that combines the developing agent moving in each of the plurality of movement areas and thereafter returns the developing agent to the plurality of movement areas; and a mixing member that mixes the developing agent entered in the confluence path.

Abstract: A developing apparatus includes: a developer carrying member carrying a developer; a plurality of developer feeders accommodating the developer carried by the developer carrying member and being arranged in an axial direction of the developer carrying member; and a collecting part that collects the developer from the developer carrying member and feeds the developer to a second developer feeder different from a first developer feeder located at a position where the developer is collected from the developer carrying member in the axial direction, among the plurality of developer feeders.

Abstract: A simplified, rigorous and accurate method of measuring pH of an analyte solution with extreme precision, which does not cause errors against actual pH through compensating a pH variation by a liquid temperature or a concentration of potassium chloride of an internal liquid in a glass electrode or a reference electrode when pH is measured with respect to various analyte solutions such as a sample solution having a high concentration of salts, a sample solution contaminated with salts and a sample solution having a low concentration of salts.

Abstract: A developing device includes a hardware processor that performs control in which a developer circulation state is switched between a first state and a second state depending on states of the developer in the first and the second regions. The first state is a state in which a developer circulation path is formed in each of the first and the second regions, and the second state is a state in which a single developer circulation path is formed all through the first and the second regions.

Abstract: An image forming apparatus includes: an image forming unit including a rotating member; a rotation position detecting unit that detects a rotation position of the rotating member; an image density detecting unit that detects density of an image; an image information analysis unit that analyzes image information; a density profile management unit that manages a density profile; a correction data generation unit that generates correction data; a density correction unit that performs density correction; and a density correction control unit that sets a density correction level, wherein when the density correction level is set at reference accuracy, the density correction unit corrects density, and when the density correction level is set at accuracy higher than the reference accuracy, the density profile management unit forms a corrective patch image and generates a new density profile, the correction data generation unit updates the correction data, and the density correction unit corrects density.

Abstract: A developing apparatus includes: a developer carrier that carries a developer; a developer casing that contains the developer to be supplied to the developer carrier; an opening/closing part capable of controlling a moving amount of the developer between a first region on one side in an axial direction of the developer carrier and a second region on the other side in the axial direction of the developer carrier by opening or closing the first region and the second region; and a hardware processor that controls an open/closed state of the opening/closing part in accordance with the state of the developer in the first region and the second region.

Abstract: A developing device includes: a plurality of development sections arranged in an axis direction of a developer bearing member; a communication section disposed at a boundary of adjacent two development sections of the development sections, and configured to communicate between the two development sections; and a control section configured to perform an operation of moving the developer between the two development sections through the communication section to equalize degradation states of the developer in the two development sections.

Abstract: An image forming apparatus includes: an image forming unit including a rotating member and being configured to form an image on a paper sheet in accordance with print job data; a rotation position detecting unit configured to detect a rotation position of the rotating member; an image density detecting unit configured to detect a density in an image formed on an image carrier; an image information analyzing unit configured to analyze image information in the print job data; a density profile managing unit configured to form a correction patch image on the image carrier, and create and manage a density profile indicating periodical density unevenness; a correction data creating unit configured to create correction data; a density correcting unit configured to perform density correction; and a density correction control unit configured to predict an appearance of periodical density unevenness, and set conditions for the density correction.

Abstract: A simplified, rigorous and accurate method of measuring pH of an analyte solution with extreme precision, which does not cause errors against actual pH through compensating a pH variation by a liquid temperature or a concentration of potassium chloride of an internal liquid in a glass electrode or a reference electrode when pH is measured with respect to various analyte solutions such as a sample solution having a high concentration of salts, a sample solution contaminated with salts and a sample solution having a low concentration of salts.

Abstract: A system for predicting occurrence of a defective image includes: an input device configured to input image data into an image forming apparatus; and a hardware processor configured to analyze a spatial frequency of gradient distribution of an image in accordance with a size of a density irregularity specific to the image forming apparatus with respect to the input image data and to calculate a probability of a conspicuous density irregularity of the size in regard to the image formed by the image forming apparatus based on the image data with reference to an index of correlation between an analysis result and an evaluation value of the density irregularity.

Abstract: A method of controlling an image forming apparatus, an image forming apparatus and image forming system are described, with which banner paper can be processed by appropriately detecting the banner paper in the fixing position when the conveyance of the banner paper is halted. The image forming apparatus comprises a paper conveying unit for conveying banner paper, an image forming unit for transferring an image to the banner paper, a fixing unit for fixing the image to the banner paper in a fixing nip by heating and pressing the banner paper conveyed along a conveying route, and a control unit. This control unit identifies information about the paper position which coincides with the fixing nip when the conveyance of the banner paper is halted and information about the amount of paper deformation of the banner paper in the paper position, and outputs the information which is identified.

Abstract: An image forming apparatus uses a first developer conveyance amount and a first correction amount calculated respectively in a first state, a second developer conveyance amount and a second correction amount calculated respectively in a second state in which the developer conveyance amount is smaller than the developer conveyance amount of the first state, and a third developer conveyance amount detected in a third state in which the developer conveyance amount is smaller than the developer conveyance amount of the first state and is larger than the developer conveyance amount of the second state to calculate a third correction amount for correcting density unevenness of the toner image in the third state, and perform control to correct the density unevenness of the toner image based on the calculated third correction amount.

Abstract: An image forming apparatus includes: an image forming unit including a rotating member and being configured to form an image on a paper sheet in accordance with print job data; a rotation position detecting unit configured to detect a rotation position of the rotating member; an image density detecting unit configured to detect a density in an image formed on an image carrier; an image information analyzing unit configured to analyze image information in the print job data; a density profile managing unit configured to form a correction patch image on the image carrier, and create and manage a density profile indicating periodical density unevenness; a correction data creating unit configured to create correction data; a density correcting unit configured to perform density correction; and a density correction control unit configured to predict an appearance of periodical density unevenness, and set conditions for the density correction.

Abstract: An image forming apparatus includes: an image forming unit including a rotating member; a rotation position detecting unit that detects a rotation position of the rotating member; an image density detecting unit that detects density of an image; an image information analysis unit that analyzes image information; a density profile management unit that manages a density profile; a correction data generation unit that generates correction data; a density correction unit that performs density correction; and a density correction control unit that sets a density correction level, wherein when the density correction level is set at reference accuracy, the density correction unit corrects density, and when the density correction level is set at accuracy higher than the reference accuracy, the density profile management unit forms a corrective patch image and generates a new density profile, the correction data generation unit updates the correction data, and the density correction unit corrects density.

Abstract: An image forming apparatus uses a first developer conveyance amount and a first correction amount calculated respectively in a first state, a second developer conveyance amount and a second correction amount calculated respectively in a second state in which the developer conveyance amount is smaller than the developer conveyance amount of the first state, and a third developer conveyance amount detected in a third state in which the developer conveyance amount is smaller than the developer conveyance amount of the first state and is larger than the developer conveyance amount of the second state to calculate a third correction amount for correcting density unevenness of the toner image in the third state, and perform control to correct the density unevenness of the toner image based on the calculated third correction amount.