Abstract: An evaluation device evaluates an image clarity of a print image. The evaluation device includes: an object that is projected onto a measurement surface of a recording medium; an illuminator that makes the object projected onto the measurement surface; an imager that images the measurement surface on which the object has been projected to obtain image data; and a hardware processor that, based on a distribution of parameters related to a brightness of the image data, quantifies a degree of the image clarity into a numerical value and defines the numerical value as an evaluation value of the image clarity.

Abstract: An image forming apparatus includes: an image carrier; an exposing device; a developing device with a developing roller; a development current detector that detects development current between the image carrier and the developing roller; and a hardware processor. Under an image forming condition, the hardware processor causes the exposing device to draw, on the image carrier, a development current-detection pattern that includes a solid image and a halftone image that follows the solid image in an image-conveying direction of the image carrier, causes the developing device to develop the development current-detection pattern, obtains information on a chronological change of the detected development current from the development current detector, and determines whether or not a ghost image due to the solid image occurs based on a temporary drop of the detected development current during development of the halftone image.

Abstract: Provided is an image forming apparatus including: a transfer member; a first image carrier on which a first toner image using toner of a first color is formed; a second image carrier which is provided on a downstream side relative to the first image carrier in a moving direction (rotating direction) of the transfer member, and on which a second toner image using toner of a second color is formed; a lubricant supply section that supplies a lubricant to the second image carrier; and a control section that controls a supply amount of the lubricant to the second image carrier in accordance with an overlap amount between the first toner image and the second toner image which are transferred from the first image carrier and the second image carrier to the transfer member.

Abstract: Provided is an image forming apparatus including: a transfer member; a first image carrier on which a first toner image using toner of a first color is formed; a second image carrier which is provided on a downstream side relative to the first image carrier in a moving direction (rotating direction) of the transfer member, and on which a second toner image using toner of a second color is formed; a lubricant supply section that supplies a lubricant to the second image carrier; and a control section that controls a supply amount of the lubricant to the second image carrier in accordance with an overlap amount between the first toner image and the second toner image which are transferred from the first image carrier and the second image carrier to the transfer member.

Abstract: Provided is an image forming apparatus including a developer that performs development with toner, the image forming apparatus including a vibrator that applies vibrations to a vibrated portion of the developer, and a hardware processor that controls the vibrator. The hardware processor determines a toner leakage level based on a result of detecting toner leakage adhering to a sheet caused by the image forming apparatus, settles a vibrating condition of the vibrator in accordance with the toner leakage level, and causes the vibrator to perform a vibrating operation under the settled vibrating condition.

Abstract: An operation status prediction system includes a hardware processor. The hardware processor acquires data, which is relevant to an operation status at each timing of an operation device to be monitored, so as to be associated with information of the timing. The hardware processor predicts a future operation status according to the acquired operation status for each of a plurality of periods having different lengths from the present.

Abstract: An image forming apparatus includes: a developer carrier; a screw-shaped developer feeder that feeds developer to the developer carrier; an image carrier on which an image is imaged with toner of the developer; a developing current detector that detects developing current between the image carrier and the developer carrier during imaging; and a controller that detects image density failure that is periodic and oblique to a rotation direction of the image carrier. The controller causes a stripe image to be imaged on the image carrier and analyzes change of the developing current with time during imaging of the stripe image, thereby detecting the image density failure. The stripe image has a width in a length direction of the image carrier narrower than a period of a blade of the developer feeder and has a length in the rotation direction longer than a period of the image density failure.

Abstract: Provided is an image forming apparatus including a developer that performs development with toner, the image forming apparatus including a vibrator that applies vibrations to a vibrated portion of the developer, and a hardware processor that controls the vibrator. The hardware processor determines a toner leakage level based on a result of detecting toner leakage adhering to a sheet caused by the image forming apparatus, settles a vibrating condition of the vibrator in accordance with the toner leakage level, and causes the vibrator to perform a vibrating operation under the settled vibrating condition.

Abstract: An image forming apparatus includes: an image carrier; an exposing device; a developing device with a developing roller; a development current detector that detects development current between the image carrier and the developing roller; and a hardware processor. Under an image forming condition, the hardware processor causes the exposing device to draw, on the image carrier, a development current-detection pattern that includes a solid image and a halftone image that follows the solid image in an image-conveying direction of the image carrier, causes the developing device to develop the development current-detection pattern, obtains information on a chronological change of the detected development current from the development current detector, and determines whether or not a ghost image due to the solid image occurs based on a temporary drop of the detected development current during development of the halftone image.

Abstract: An image forming apparatus includes: a developer carrier; a screw-shaped developer feeder that feeds developer to the developer carrier; an image carrier on which an image is imaged with toner of the developer; a developing current detector that detects developing current between the image carrier and the developer carrier during imaging; and a controller that detects image density failure that is periodic and oblique to a rotation direction of the image carrier. The controller causes a stripe image to be imaged on the image carrier and analyzes change of the developing current with time during imaging of the stripe image, thereby detecting the image density failure. The stripe image has a width in a length direction of the image carrier narrower than a period of a blade of the developer feeder and has a length in the rotation direction longer than a period of the image density failure.

Abstract: An evaluation device evaluates an image clarity of a print image. The evaluation device includes: an object that is projected onto a measurement surface of a recording medium; an illuminator that makes the object projected onto the measurement surface; an imager that images the measurement surface on which the object has been projected to obtain image data; and a hardware processor that, based on a distribution of parameters related to a brightness of the image data, quantifies a degree of the image clarity into a numerical value and defines the numerical value as an evaluation value of the image clarity.

Abstract: An image forming apparatus includes a cleaning member formed by an elastic body, and a member to be cleaned in which toner added with an external additive adheres to a surface, and the toner is to be cleaned by the cleaning member being in contact with the surface, wherein the cleaning member has a protrusion disposed on a cleaning surface extending from a contact part with the member to be cleaned, and facing a side where the toner is to be cleaned, of the member to be cleaned.

Abstract: An image forming apparatus including: an image carrier that carries a toner image; a cleaner that contacts a surface of the image carrier and removes a toner, the cleaner being located at a first position during stop of rotation of the image carrier and located at a second position during rotation of the image carrier; a moving mechanism that moves the cleaner between the first position and the second position by moving the cleaner in a direction parallel to a rotation shaft of the image carrier while maintaining a contact state between the cleaner and the image carrier; and a hardware processor, in which the hardware processor starts to move the cleaner from the first position to the second position with the moving mechanism during stop of the rotation of the image carrier, and the hardware processor starts to rotate the image carrier during movement of the cleaner.

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: An image forming apparatus includes a cleaning member formed by an elastic body, and a member to be cleaned in which toner added with an external additive adheres to a surface, and the toner is to be cleaned by the cleaning member being in contact with the surface, wherein the cleaning member has a protrusion disposed on a cleaning surface extending from a contact part with the member to be cleaned, and facing a side where the toner is to be cleaned, of the member to be cleaned.

Abstract: An image forming apparatus includes: a developer casing that accommodates a developer; a developer detector that is disposed in the developer casing, and that detects, based on magnetic force, the developer from a plurality of detection ranges that is close to each other and is disposed side by side in a vertical direction in the developer casing; and a hardware processor that performs control of detecting a liquid level position of the developer in the developer casing, based on a detection result detected by the developer detector.

Abstract: A developing apparatus includes: a developer carrying body that carries a developer and is rotationally driven; a developer stirring member that is rotationally driven and thereby stirs the developer and conveys the developer to the developer carrying body; and a developer recovery member that is rotationally driven and thereby returns and recovers the developer stripped from the developer carrying body after development of the electrostatic latent image, to the developer stirring member, wherein a driving speed of the developer stirring member and a driving speed of the developer recovery member are independently controllable from each other.

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: An image forming apparatus includes: a developer casing that accommodates a developer; an developer detector that is disposed in the developer casing, and that detects, based on magnetic force, the developer from a plurality of detection ranges that is close to each other and is disposed side by side in a vertical direction in the developer casing; and a hardware processor that performs control of detecting a liquid level position of the developer in the developer casing, based on a detection result detected by the developer detector.

Abstract: A developing apparatus includes a developer carrier that carries a developer, and a developer casing that contains the developer to be supplied to the developer carrier. An opening/closing part is 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. A hardware processor 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.