Canon Kabushiki Kaisha

Shunichi Takada

Yasunori Chigono

Koichi Hashimoto

Tomohito Ishida

Makoto Fukatsu

Kenta Kubo

Emi Hagiwara

Shintaro Ishida

Tetsuya Atsumi

Tatsuya Tada

Mitsuhiro Furukawa

Megumi Uchino

Masahiro Ootsuka

Tatsuya Inoue

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.

Image forming apparatus that executes a mode for driving each of conveyance member and developer carrying member without executing image forming operation

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.

Developing device having a developer carrying member with recessed portions

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.

Image forming apparatus and image forming method for reducing toner bearing amount, and storage medium thereof

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.

Image forming apparatus

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.

Glossiness processing apparatus and image forming apparatus

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. In the glossiness treatment mode, one of the image forming stations forms, as a topmost layer, a toner image having a tone gradation provided by a dot growth type screening, and an image forming station, other than the one for forming the topmost toner image, forms the toner image having the tone gradation provided by a line growth type screening.

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Soka, Japan

Shunichi Takada