Kyocera Document Solutions Inc.

Minolta Company, Ltd.

Minolta Camera Kabushiki Kaisha

Kyocera Mita Corporation

Yocera Document Solutions Inc.

Tamotsu Shimizu

Kenichi Tamaki

Kazunori Tanaka

Yasuhiro Tauchi

Yoshihiro Yamagishi

Shizuka Okada

Takahisa Nakaue

Akifumi Yamaguchi

Masashi Fujishima

Akihiro Watanabe

Hiroshi Yamazaki

Minoru Wada

Yuji Toyota

Takuji Watanabe

Kazuhiro Nakachi

Junichi Nakagawa

Takashi Morita

Teruhiko Nagashima

Takefumi Yotsutsuji

Norio Kubo

Asami Sasaki

Yasuhiro Oishi

Akira Matayoshi

Ikuo Makie

Sakae Saito

Yuji Kamiyama

Takahiro Okubo

Yasushi Imanishi

Koji Suenami

Kanako Morimoto

Eiji Gyotoku

Yoshinobu Yoneima

Yoshiyuki Iguchi

Yoshio Sakagawa

Shizuka Ikazaki

Hiroshi Murasaki

Hiroka Itani

Yu Sasaki

Chikara Ishihara

Kensuke Fujihara

Noboru Ito

Ryota Maeda

Mitsuhiro Hashimoto

Shiro Kaneko

Masaki Hayashi

Masahiko Matsuura

Eiji Nimura

Koji Fujii

Koji Kuramashi

Ryo Taniguchi

Ryota Okui

Susumu Mikawa

Yohei Wakasa

Hiroshi Mizuno

Junji Machida

Masaki Kadota

Yukihiro Mori

Ai Takagami

Koji Uno

Yukimasa Watanabe

Masaru Hatano

Kenichi Kasama

Junji Ohtani

Yuta Kitabayashi

Nobuyuki Hayashi

Yoshimi Shimizu

Satoshi Sunayama

Yoshihisa Terasaka

Hiroaki Sakai

Tomoyuki Kikuta

Kanako Kikuchi

Ryo Yamada

Akane Tokushige

Kouji Fujii

Eiji Gyoutoku

Uto Syu

Eriko Takeuchi

The developing device includes a development container, a developer carrier, and a toner trapping mechanism. The development container includes a first conveyance chamber and a second conveyance chamber placed in parallel juxtaposition and communicated with each other at their longitudinal both end portions, and the development container contains a toner-containing developer to be fed to an image carrier. The toner trapping mechanism includes a duct, an air inlet port, a trapping filter, and a fan. The duct is connected to the second conveyance chamber, and allows air present in the second conveyance chamber to flow therethrough. The development container has an air vent opened in the first conveyance chamber and communicated with outside of the development container.

Developing device and image forming apparatus

The image forming apparatus includes a developing part and a vibration generating part. The vibration generating part vibrates a filter provided in the developing part. The developing part includes a development container, a developer carrier, and a toner trapping mechanism. The development container includes a first conveyance chamber and a second conveyance chamber placed in parallel juxtaposition. The toner trapping mechanism has a duct, an air inlet port, an air exhaust port, and a filter. The air inlet port is opened along the longitudinal direction of the second conveyance chamber so as to allow air present in the second conveyance chamber to flow into the duct. The vibration generating part is placed outside the developing part so as to be opposed to the development container and positioned on a downstream side in a developer conveyance direction of the second conveyance chamber.

Developing device provided with a toner trapping mechanism

Provided is an image forming apparatus in which, while image formation is prevented from being performed, scattered toner that has dropped from a filter and adhered to an outer peripheral surface of a developer carrying member is recovered. A fixed magnet of the developer carrying member has a first pole that is arranged to face the filter, and a second pole and a third pole on a downstream side relative to the first pole. The first pole and the second pole have polarities opposite to each other, and the second pole and the third pole have a same polarity. A length of a gap between the developing container and an area where the developing sleeve faces the second pole among areas of the developing sleeve is smaller than a length between the developing sleeve and the filter.

Image forming apparatus

Provided is an image forming apparatus that is capable of carrying out a scattered-toner recovery mode in which, while image formation is prevented from being performed, scattered toner that has dropped from a filter and adhered to an outer peripheral surface of a developer carrying member is recovered by a cleaning unit through intermediation of an image bearing member. A fixed magnet of the developer carrying member has a first pole that faces the image bearing member, a second pole that faces the filter, and an intermediate pole between the first pole and the second pole.

An image forming apparatus includes a developer, a development device, and an image bearing member. The developer includes an initial developer containing an initial carrier and a replenishment developer containing a replenishment carrier. The initial carrier has a surface roughness Sa1 of at least 0.3 μm and no greater than 1.0 μm. A ratio Sa1/Sa2 of the surface roughness Sa1 of the initial carrier to a surface roughness Sa2 of the replenishment carrier is at least 1.2 and no greater than 3.4. The packing volume Vp calculated from equation (1)'Vp=100×Y/(Z×DS)' was at least 40% and no greater than 70%. In equation (1), Y represents an amount of the developer conveyed by a developer bearing member. Z represents an apparent density of the initial developer. DS represents a width of a space between the developer bearing member and the image bearing member.

Image forming apparatus and image formation method

An image forming apparatus includes first, second, and third acquisition processing portions. The first acquisition processing portion acquires the potential value of a charged area, charged by the charging member, on the image-carrying member. The second acquisition processing portion acquires a state value regarding the state of a surface layer of the image-carrying member based on the potential value of the charged area acquired by the first acquisition processing portion and the current value of a charging current flowing through the charging member during formation of the charged area. The third acquisition processing portion acquires the electrical resistance value of the transfer member based on the state value acquired by the second acquisition processing portion, the voltage value of a transfer voltage applied to the transfer member, and the current value of a transfer current flowing through the charged area in response to application of the transfer voltage.

Image forming apparatus capable of accurately acquiring electrical resistance value of transfer member, electrical resistance value acquisition method

Provided is an image forming apparatus in which, while image formation is prevented from being performed, scattered toner that has dropped from a filter and adhered to an outer peripheral surface of a developer carrying member is recovered by a cleaning unit through intermediation of an image bearing member. An absolute value of a perpendicular-magnetic-force gradient of a fixed magnet of the developer carrying member is 4.0 mT/° or less at a position where the fixed magnet faces a central portion of the filter in a rotation direction of a developing sleeve.

An image forming apparatus includes a developing member, a first detection processing portion, and an acquisition processing portion. The developing member conveys developer to a facing portion between the developing member and the image-carrying member. The first detection processing portion detects a first development current for each of a plurality of specific voltages with different DC voltage values applied to the developing member, the first development current flowing, in response to application of the specific voltages, through the facing portion including the developer and a specific exposed area, formed by the light emitting portion, on the image-carrying member. The acquisition processing portion acquires a potential value of the specific exposed area based on the DC voltage values of the specific voltages and current values of the first development current, detected by the first detection processing portion, corresponding to the respective specific voltages.

Image forming apparatus capable of acquiring potential value of exposed area on image-carrying member, potential value acquisition method

An image forming apparatus includes an image carrier, a cleaning unit, a development device, and a control unit. The development device includes a toner collection mechanism having a developer carrier and a filter. The control unit is capable of executing a scattered toner recovery mode at non-image forming time, in which the filter is vibrated, a potential difference is generated in the direction for the toner to move from the developer carrier to the image carrier, the developer carrier is rotated in a reverse direction to that at image forming time, and the image carrier is rotated in the same direction as that at the image forming time, so that scattered toner, which has dropped from the filter and adhered to the developer carrier, is recovered by the cleaning unit via the image carrier.

An image forming apparatus includes a development device, and a control unit that controls the development device. The development device includes a toner collection mechanism having a duct, a filter, and an exhaust fan. The duct is connected to a conveyance chamber of the development container and allows air in the conveyance chamber to flow through. The filter is disposed at a connecting part between the duct and the conveyance chamber, and collects toner flowing into the duct from the conveyance chamber. The exhaust fan makes the air in the conveyance chamber flow to the outside via the duct. The control unit changes rotational frequency or operation frequency of the exhaust fan based on current detected by a current detection unit at non-image forming time.

A developing device includes a developing container storing a two-component developer containing a magnetic carrier and a toner, a developer carrying member carrying the developer on its outer circumferential surface, and a regulation member arranged to be opposed at a prescribed distance to the developer carrying member. The developer carrying member includes a developing sleeve on which a magnetic brush is formed, and a magnet secured in the developing sleeve and having a plurality of magnetic poles including a regulation pole opposed to the regulation member and a downstream-side magnetic pole arranged downstream of the regulation pole with respect to the rotation direction of the developing sleeve. The magnet is such that the vertical magnetic force gradient [mT/°] has a local minimum value near a position at which the vertical magnetic force is 0 [mT] between the downstream-side surface of the regulation member and the downstream-side magnetic pole.

Developing device and image forming apparatus including the same

A developing device includes a developing container, a first stirring conveyance member, a second stirring conveyance member, a developer carrying member including a developing sleeve and a magnet, and a regulation member. The regulation pole in the magnet has a region extending over 10° or more in which a maximum value of a vertical magnetic force is not more than 65 [mT] and a vertical magnetic force gradient is not more than 0.3 [mT/°]. A peak position of the vertical magnetic force gradient of the regulation pole is arranged at a position opposed to the second stirring conveyance member, and when a value of the vertical magnetic force gradient and a value of the vertical magnetic force at the peak position of the vertical magnetic force gradient are indicated as A [mT/°] and K [mT], respectively, A≥2.8 and A×K≥62.5 are satisfied.

Developing device including developer carrying member and containing two-component developer and image forming apparatus including the developing device

A developing device includes a developing container storing a two-component developer, a developer carrying member, and a regulation member. The developer carrying member includes a developing sleeve, and a magnet having a regulation pole opposite the regulation member and a main pole opposite the image carrying member. The regulation member is arranged downstream of the position at which the vertical magnetic force of the regulation pole is 0 [mT] but upstream of a position at which the vertical and horizontal magnetic forces of the regulation pole are equal. Let the horizontal magnetic force gradient at the position at which the horizontal magnetic force of the main pole is 0 [mT] be A and the horizontal magnetic force gradient at the upstream-side surface of the regulation member along the rotation direction of the developing sleeve be B, then |A|&#x3e;2.45 and |B|&#x3c;1.30.

An image forming portion applies a bias voltage in which an AC component is superimposed on a DC component between a first carrying member and a second carrying member, and transfers toner from the first carrying member to the second carrying member to form an image on the second carrying member. An AC setting processing portion performs AC calibration to set a magnitude of the AC component of the bias voltage. A potential measurement processing portion measures a surface potential of the first carrying member or the second carrying member based on a target current flowing between the first carrying member and the second carrying member. A drive processing portion executes the AC calibration before measurement of the surface potential in a case where, when measuring the surface potential, an activation condition is satisfied.

Image forming apparatus and control method of image forming apparatus

An image forming apparatus includes an amorphous silicon photosensitive member, a developing device including a developer carrying member that carries a two-component developer, and a control portion. When a potential difference V0&#x2212;Vdc between the photosensitive member and the developer carrying member has a first potential difference at which the toner is moved from the developer carrying member to the photosensitive member and a second potential difference at which the toner is moved from the photosensitive member to the developer carrying member, the control portion adjusts V0 or Vdc so that the first potential difference and the second potential difference are equal in value and opposite in polarity, and a first development current |Ia| that flows at the first potential difference and a second development current |Ib| that flows at the second potential difference satisfy 1.9&#xd7;10&#x2265;|Ib|/N&#x2265;5.7&#xd7;10[&#x3bc;A/mm].

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Osaka, Japan

Tamotsu Shimizu