Ricoh Company, Ltd.

Shin Murayama

Shintaro Yamada

Ryuji Inoue

Shuuichi Nakagawa

Kazushige Oonishi

Yuji Nagatomo

Rumi Konishi

Shin Yamamoto

Yoshio Sakagawa

Yasuhide Matsuno

Kazushige Ohnishi

Tomofumi Yoshida

Hirobumi Ooyoshi

Yoshimichi Ishikawa

Masanari Fujita

Tetsumaru Fujita

Chiyoshi Nozaki

Manabu Hamada

Shinichi Arasawa

Shuichi Nakagawa

Yoshiko Ogawa

Kenji Asuwa

An image forming apparatus includes a latent image bearer, a charging roller, a first cleaner, a second cleaner, and a rotation controller. The latent image bearer bears a latent image on a surface thereof. The charging roller charges the latent image bearer. The first cleaner cleans the surface of the latent image bearer. The second cleaner cleans a surface of the charging roller. The rotation controller controls the latent image bearer to execute a set of backward rotation and first forward rotation at least once during a non-image formation time period, and either temporarily stop and start second forward rotation or continuously execute the second forward rotation by a rotation distance corresponding to at least one rotation of the charging roller.

Image forming apparatus and driving method for driving image forming apparatus

A developing device includes a developer bearer and a regulation member. The developer bearer bears developer on a surface thereof. The developer bearer is rotatable forward and in reverse. The regulation member is disposed in contact or non-contact with the surface of the developer bearer to regulate amount of the developer on the developer bearer. In a non-development period, when the developer bearer rotates in a direction of reverse rotation opposite to a direction of forward rotation in which the developer bearer rotates in a development period, the developer bearer stops a series of rotating operations after the developer bearer rotates in the direction of forward rotation as a last rotating operation. A total rotation amount of forward rotation is set to be greater than a total rotation amount of reverse rotation in the series of rotating operations.

Developing device and image forming apparatus including same

An image forming apparatus includes a rotatable photoconductor, a charging unit, an exposure unit to expose the photoconductor to reduce an electrical potential at the photoconductor, a developing unit to charge the toner held on a toner bearing member with friction and attract the toner to the exposed portion on the photoconductor by supplying a development voltage from a first power source and using an electrical potential difference between the toner bearing member and the photoconductor in the development area, a reverse development voltage controller to supply a reverse development voltage while a non-charged portion on the photoconductor passes the development area, and a developer reducing potential applier to supply a development restraining potential and an absolute value smaller than a target charging potential to the photoconductor while the reverse development voltage is supplied.

Image forming apparatus including a controller configured to regulate a potential difference between a photoconductor and a developing member

A semiconductive member including an alkali metal salt having the formula (M).X in a surface layer thereof. M represents Na, K, or Li; X represents Cl, Br, I, F, CHCOO, CFCOO, CH(COOH)CHCOO, (CHCOO), CH(COOH)CHCOO, (CHCOO), (HOOC)Ar(COO), Ar(COO), (HOOC)Ar(COO), (HOOC)Ar(COO), Ar(COO), (HOOC)Ar(COO), (HOOC)Ar(COO), (HOOC)Ar(COO), Ar(COO), Ar&#x2014;SO, Ar(SO), an oligomer or a polymer having an acrylic acid anion unit, or an oligomer or a polymer having an methacrylic acid anion unit; Ar represents a benzene ring, a naphthalene ring, or a biphenyl ring; and n is a numeral equivalent to the anionic valence of X.

Semiconductive member, and developing roll, charging roll, transfer belt, and image forming apparatus using same

A developing device develops an electrostatic latent image formed on an image carrier with toner. The developing device includes a developer carrier, a developer supplying unit that supplies a developer on the developer carrier, a layer shaping member that shapes the developer supplied on the developer carrier into a thin layer, and an electric-field control member that is arranged downstream of a shaping nip formed between the developer carrier and the layer shaping member and that controls an intensity of an electric field generated between the developer carrier and the layer shaping member.

Device for developing an electrostatic latent image, and process cartridge and image forming apparatus including the same

A developing device for developing an electrostatic latent image on an image carrier by supplying a one-component developer to the image carrier. Good images can be obtained over long periods of time, without printing history becoming apparent on account of residual developer. The developing device has a developer carrier that is rotatable and disposed facing an image carrier; and a conductive developer supply and recovery member rotatably arranged so as to abut the developer carrier. The rotation direction of the conductive developer supply and recovery member is opposite to the rotation direction of the developer carrier at a position where the developer carrier and the conductive developer supply and recovery member abut each other. A contact pressure P between the developer carrier and the conductive developer supply and recovery member is set so as to satisfy the relationship 0 (kPa)&#x3c;P&#x3c;5.0 (kPa).

Developing device, process cartridge and image forming apparatus

A developer regulating member capable of stably regulating the thickness of a developer even when used for a long time, while preventing the increase in the production cost, a developing device having the developer regulating member, an image forming apparatus having the developing device, a process cartridge, and a method of producing the developer regulating member. The average crystal particle diameter D [&#x3bc;m] of a plate-like member provided in a layer-thinning blade which functions as the developer regulating member and which abuts against a developing roller functioning as a developer carrier, and the curvature radius R [&#x3bc;m] of a bent portion satisfy the relationship of D&#x2266;60.53&#xd7;R&#xd7;10&#x2212;12.61.

Developing device having developer regulating member, and image forming apparatus using developing device

A developing device that prevents the formation of agglomerated masses of developing agent in the bottom of the developing agent housing chamber near the developing roller and the supply roller, and that maintains the fluidity of the developing agent in the bottom of the developing agent housing chamber, while minimizing any increase in size of the developing device. The developing device includes an agitator disposed higher than the developing roller, the regulating blade, and the supply roller, and that agitates a non-magnetic one component developing agent within the developing agent housing chamber; and a developing agent ingress prevention member disposed higher than the supply roller, and lower than the agitator, and the side surface or edge portion of the developing agent ingress prevention member near the developing roller is higher than the topmost point of the supply roller, and lower than the lowermost point of the regulating nip formed by the contact of the developing roller and the regulating blade.

Developing device, process unit, and image forming apparatus which prevents ingrass of the developing agent in the vicinity of the developing member

A developing device that can reliably supply toner from a toner supply roller to a developing roller and that does not generate scraping irregularities in the toner thin layer on the developing roller, and a process cartridge and an image forming apparatus having the same. The developing device has: a toner supply chamber; a developing roller provided in the toner supply chamber; a toner supply roller provided in the toner supply chamber for supplying toner to the developing roller; and a layer regulation member for forming the toner on the developing roller into a thin layer, and develops electrostatic latent images on an image carrier by applying bias voltage to the developing roller. An intermediate contact member is interposed between the developing roller and the toner supply roller. The intermediate contact member is a sheet member fixed at one end, and the free end of the sheet member is interposed between the developing roller and the toner supply roller, with the free end side protruding therebetween.

Developing device for image forming apparatus and process cartridge having the same

An image developing method is disclosed that is able to efficiently remove degraded toner on a developing agent carrier, prevent formation of abnormal images, ensure good image quality over time, and increase the service life of the device. The developing method includes a step of calculating an amount of consumption of the developing agent during image formation and an amount of consumption of the developing agent in a compulsory toner consumption mode under different calculation conditions between the image formation and the compulsory toner consumption mode. In the compulsory toner consumption mode, a developing bias different from a developing bias used during image formation is applied for a predetermined time period to discharge residual developing agent on a developing agent carrier to a latent image carrier.

Image developing method, image developing device, and image forming device

A disclosed developing device includes a developing roller; a supply roller that is in contact with the developing roller and configured to supply toner to the developing roller; a current measuring unit configured to measure an electric current that flows from the developing roller to the supply roller when the toner is supplied from the supply roller to the developing roller; and an error determining unit configured to detect a development error of the developing roller based on the electric current measured by the current measuring unit.

Developing device, image forming apparatus, and development error detecting method

A developing device is provided with which the increase in torque of a supply roller, unevenness of image density, and wear to the supply roller caused by the formation of an aggregated block of toner in the gap between the supply roller and the opposing side wall of a supply developer holding chamber can be suppressed. This developing device comprises a developing roller for developing an electrostatic latent image supported on a photoconductive member, a supply developer holding chamber for holding toner to be supplied to the developing roller, a supply roller for supplying the toner supported on the peripheral face thereof to the developing roller, a hopper that is disposed above the supply developer holding chamber and used to hold toner for replenishing the supply developer holding chamber, and a communication opening for allowing the hopper to communicate with the supply agent holding chamber, wherein a canopy member is provided directly above the gap to impede the advance of the toner on the supply roller into the gap between the supply roller and the opposing side wall of the supply developer holding chamber.

Developing device including an advance impeding member and an image forming apparatus using the same

A developing apparatus is disclosed that includes a developer carrier for carrying a developer used for developing a latent image, a developer supplying chamber having a developer supplying member for supplying the developer to the developer carrier by rotation, a developer storing chamber positioned above the developer supplying chamber for storing the developer and supplying the developer to the developer supplying chamber, and a partitioning member positioned between the developer supplying chamber and the developer storing chamber. The partitioning member has an opening through which the developer is supplied from the developer storing chamber to the developer supplying chamber. The developing apparatus includes a conveying member positioned above the partitioning member for conveying the developer in a substantially horizontal direction. The conveying member has an opening facing part situated directly above the opening for conveying the developer with less force than the other parts of the conveying member.

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Hyogo, Japan

Shin Murayama