Abstract: An image forming apparatus to execute an image forming operation for forming an image includes an image bearing member, a development unit, a drive unit, a controller, and a humidity detection unit to detect humidity near the development unit. The development unit contains developer and includes a conveyance member to convey the developer and a developer carrying member to carry the developer to a position where an electrostatic latent image formed on the image bearing member is developed. The controller controls the conveyance and the developer carrying member through the drive unit not to execute a mode for driving the conveyance and the developer carrying member without executing the image forming operation when the humidity detected when power of the image forming apparatus is shifted from off to on is higher than a predetermined value, and to execute the mode when the detected humidity falls below the predetermined value afterward.

Abstract: An image forming apparatus to execute an image forming operation for forming an image includes an image bearing member, a development unit, a drive unit, a controller, and a humidity detection unit to detect humidity near the development unit. The development unit contains developer and includes a conveyance member to convey the developer and a developer carrying member to carry the developer to a position where an electrostatic latent image formed on the image bearing member is developed. The controller controls the conveyance and the developer carrying member through the drive unit not to execute a mode for driving the conveyance and the developer carrying member without executing the image forming operation when the humidity detected when power of the image forming apparatus is shifted from off to on is higher than a predetermined value, and to execute the mode when the detected humidity falls below the predetermined value afterward.

Abstract: A developing device includes a developing container, a feeding member, a developer carrying member, and a collecting device. A coverage which is a percentage of coating of surfaces of the carrier particles with the toner particles is 100% or more and 200% or less. The developer carrying member has a plurality of recessed portions formed on a surface thereof so that at least the toner particles having an average particle size are contactable with inner surfaces of the recessed portions, and the carrier particles having an average particle size are not contactable with the inner surfaces of the recessed portions. The recessed portions are formed so that not less than half of the toner particles having the average particle size are exposed from the recessed portions when the toner particles having the average particle size enter the recessed portions.

Abstract: A developing apparatus of the present disclosure includes a developing sleeve including a plurality of magnetic substance portions bearing, on a surface thereof, developer containing toner and carrier and conveying the developer to a developing area facing a photosensitive drum, and a magnet roller disposed within the developing sleeve and generating magnetic fluxes passing through the magnetic substance portion. The magnetic substance portion includes, on an end surface thereof, a high flux density portion disposed at least one of upstream and downstream parts in a conveyance direction of the developing sleeve and through which the magnetic fluxes pass and a low flux density portion through which the magnetic fluxes whose density is lower than the magnetic fluxes passing through the high flux density portion pass.

Abstract: A developer supply member, a toner collecting member, and a transfer member are arranged in order from an upper stream in a rotation direction of a developer bearing member, the developer bearing member bears an electrostatic image and includes a plurality of concave portions, a proportion of the concave portions per unit area in at least a toner bearing region of the developer bearing member is 55% or higher, a difference of potential is formed between the developer bearing member and the toner collecting member, and the toner t on the surface of the developer bearing member is collected through the difference of potential.

Abstract: An image forming apparatus that can reduce a toner bearing amount stably regardless of a density of an image. The image forming apparatus comprises a first generating unit which generates a reference pattern, and a second generating unit which generates, based on image data, a correction pattern for thinning out dots at a region from halftone density to high density. The image data is converted based on the reference pattern generated by the first generating unit and the correction pattern generated by the second generating unit. The image forming apparatus further comprises a photoreceptor. The photoreceptor is charged, the charged photoreceptor is exposed based on the converted image data to form an electrostatic latent image, and the electrostatic latent image is developed.

Abstract: An exposure unit forms an electrostatic latent image on the surface of the photoconductor by exposing a photoconductor charged by a charging unit. The electrostatic latent image includes a patterned latent image having a periodic pattern and a printing latent image according to image information to be printed. The patterned latent image includes exposed sections exposed by the exposure unit and unexposed sections less exposed than the exposed sections. Each of the exposed sections occupies 30% or more and 70% or less of an area of one period of the patterned latent image. The period of the patterned latent image in a width direction intersecting the periodic pattern is 100% or more and less than 400% of an average particle diameter of the toner.

Abstract: A developing device includes a developing member and a carrier collecting member. An outer surface of the developing member includes a plurality of protrusion portions aligned at regular intervals that are equal to or larger than an average particle diameter of toner particles and smaller than an average particle diameter of magnetic carrier particles. Each protrusion portion has a first face formed at one side of an apex of each protrusion portion and a second face formed at the other side of the apex, and an inclination angle of the first face is less than an inclination angle of the second face. In the circumferential direction of the developing member, when a downward direction of the first face is set to be positive, a relative velocity of a surface velocity of an image bearing member to a surface velocity of the developing member is set to be positive.

Abstract: A developing device includes: a developing container, a feeding member, a developer carrying member, and a collecting device. A coverage which is a percentage of coating of surfaces of the carrier particles with the toner particles is 100% or more and 200% or less. The developer carrying member has a plurality of recessed portions formed on a surface thereof so that at least the toner particles having an average particle size are contactable with inner surfaces of the recessed portions and the carrier particles having an average particle size are not contactable with the inner surfaces of the recessed portions. The recessed portions are formed so that not less than halves of the toner particles having the average particle size are exposed from the recessed portions when the toner particles having the average particle size enter the recessed portions.

Abstract: An image forming apparatus that can reduce a toner bearing amount stably regardless of a density of an image. The image forming apparatus comprises a first generating unit which generates a reference pattern, and a second generating unit which generates, based on image data, a correction pattern for thinning out dots at a region from halftone density to high density. The image data is converted based on the reference pattern generated by the first generating unit and the correction pattern generated by the second generating unit. The image forming apparatus further comprises a photoreceptor. The photoreceptor is charged, the charged photoreceptor is exposed based on the converted image data to form an electrostatic latent image, and the electrostatic latent image is developed.

Abstract: An image forming apparatus includes: an image bearing member; an electric potential sensor which detects electric potential of a toner image; a density sensor which acquires information of a density of the toner image; and a controller which controls contrast electric potential and the AC bias based on a result of the detection of the density sensor and a predetermined target value, wherein the controller decreases the development contrast, and increases the AC bias, when a charging electric potential difference, which is a potential difference between a potential of a predetermined toner image developed by the development device on the image bearing member and the DC bias applied to the development device when the predetermined toner image is developed, increases from a first predetermined value to a second predetermined value;

Abstract: An image forming apparatus includes: a developing container; a concave-convex member which has a plurality of grooves formed in a rotation direction; a collecting portion; and a receiving member, wherein each groove has side surfaces including a first side surface formed in one direction and a second side surface formed in the other direction in a circumferential direction of the concave-convex member, wherein the first side surface has a smaller inclination angle than the second side surface, and when a direction which moves down the first side surface in the circumferential direction of the concave-convex member is set to be positive, a relative velocity of a surface velocity of the concave-convex member to a surface velocity of the receiving member is set to be positive, at a position in which the concave-convex member and the receiving member come into contact with each other.

Abstract: The image forming apparatus includes an image carrier, a developer carrier, a magnetic field generation unit that is fixedly disposed in a hollow part of the developer carrier and includes a plurality of magnetic poles disposed in a circumferential direction of the developer carrier, a conductive member disposed so as to oppose a predetermined magnetic pole, of the plurality of magnetic poles, which is located odd-number pole upstream of a magnetic pole corresponding to a developing area D in a rotational direction of the developer carrier, a power source that can apply a voltage to the conductive member, a potential detection unit configured to detect pre-development and post-development potentials of a predetermined image formed on the image carrier, and a changing unit configured to change the voltage to be applied from the power source to the conductive member based on a detection result obtained by the potential detection unit.

Abstract: A glossiness processing apparatus for glossiness treatment includes a first glossiness treatment unit; a second glossiness treatment unit provided downstream of the first glossiness treatment unit with respect to a feeding direction of a sheet; wherein each of the units including a film movable having a surface in contact with an image surface of the sheet while moving; a heating member contacted to another surface of the film, the heating member including a plurality of heat generating elements arranged along a direction substantially perpendicular to a moving direction of the film; a pressing member cooperating with the heating member to form a nip, with the film therebetween, for nipping and feeding the sheet; wherein positions of the heat generating elements are offset relative to positions of the heat generating elements of the first glossiness treatment unit.

Abstract: An image forming apparatus includes a plurality of image forming stations for forming a toner image having superposed toner image components on a recording material, a fixing portion for fixing the toner image on the recording material, and a glossiness treatment unit, operable when a glossiness treatment mode is selected, for glossiness treatment of the toner image fixed on the recording material by heating the toner image. The glossiness treatment unit includes a film movable in a feeding direction of the recording material, a heating member contacting the film, and a pressing member cooperating with the heating member to form a nip, with the film therebetween, for nipping and feeding the recording material.

Abstract: An image forming apparatus includes an image forming unit for forming a toner image on a recording material; a fixing portion for fixing the toner image; a glossiness treatment unit, operable when a glossiness treatment mode is selected, for glossiness treatment of the toner image fixed on the recording material by heating the toner image, the glossiness treatment unit including a film movable in a feeding direction of the recording material, a heating member contacted to the film, a pressing member cooperating with the heating member to form a nip, with the film therebetween, for nipping and feeding the recording material; wherein in the glossiness treatment mode, the image forming unit forms, as a topmost layer, a toner image having a tone gradation provided by a dot growth type screening.

Abstract: A glossiness processing apparatus for glossiness treatment includes a first glossiness treatment unit; a second glossiness treatment unit provided downstream of the first glossiness treatment unit with respect to a feeding direction of a sheet; wherein each of the units including a film movable having a surface in contact with an image surface of the sheet while moving; a heating member contacted to another surface of the film, the heating member including a plurality of heat generating elements arranged along a direction substantially perpendicular to a moving direction of the film; a pressing member cooperating with the heating member to form a nip, with the film therebetween, for nipping and feeding the sheet; wherein positions of the heat generating elements are offset relative to positions of the heat generating elements of the first glossiness treatment unit.

Abstract: A sheet surface treating apparatus includes a heater including a substrate and a heat generating element provided on the substrate; a transfer film which is movable while contacting the heater; a pressing member cooperating with the heater to form a nip for feeding a sheet carrying thermoplastic resin material, through the transfer film; wherein the sheet is fed by the nip together with the transfer film in a state that the thermoplastic resin material is in contact with the transfer film, and is heated by the heater in the nip so that a configuration of a surface of the transfer film is transferred to the thermoplastic resin material, and then is separated from the transfer film; wherein a downstream end of the heat generating element with respect to a sheet feeding direction is disposed at a position upstream of an end of the nip with respect to the sheet feeding direction, and a distance between the downstream end of the nip and the downstream end of the heat generating element is not less than 0.