Ricoh Company, Ltd.

Yoshiko Ogawa

Masaaki Yamada

Yasuyuki Ishii

Yuuji Ishikura

Atsushi Kurokawa

Tetsuro Hirota

Hideyasu Seki

Hideki Kosugi

Osamu Endou

Yuji Ishikura

Yasunobu Shimizu

Akira Azami

Akihiro Kawasaki

Yoshiharu Kishi

Rumi Konishi

Junichi Matsumoto

Toshio Koike

Masanori Horike

Noriyuki Kimura

Yuki Oshikawa

Yoshihiro Fujiwara

Yoshiyuki Fukuda

Kei Saito

Kenichi Ono

Yutaka Takahashi

Shin Kayahara

Ryuji Inoue

Motohiro Kawanabe

Shintaro Yamada

Atsushi Takehara

Keinosuke Kondoh

Yoshio Sakagawa

Akihiro Kawakami

Kimihiro Tanaka

Mutsuki Morinaga

Kenji Asuwa

Shin Murayama

Shuuichi Nakagawa

Kentaro Mikuniya

Shingo Nagatsuka

Takuya Etoh

Kazushige Oonishi

A developing device includes a developer bearer to carry, by rotation, developer including toner and magnetic carrier to a developing range facing a latent image bearer; a casing including a developer container and an opening to expose a part of the developer bearer disposed in the casing; an opposing face of the casing including a conductive material and opposing to a surface of the developer bearer downstream from the developing range in a direction of rotation of the developer bearer; a developing bias source to apply a developing bias to the developer bearer; and an insulation layer disposed on the opposing face of the casing. The opposing face is disposed across, from the developer bearer, a casing gap sized to allow the developer borne on the developer bearer to contact the opposing face.

Developing device, and image forming apparatus and process cartridge incorporating same

A developing device includes a developer bearer disposed facing a latent image bearer in a developing range to transport developer by rotation, a support to support the developer bearer and including a holder mount, a rod-shaped developer regulator disposed facing a surface of the developer bearer across a gap, and a holder secured to the holder mount of the support to hold the rod-shaped developer regulator. The rod-shaped developer regulator extends in an axial direction of the developer bearer.

Developing device and image forming apparatus incorporating same

A developing device including: a toner bearing member configured to bear a toner on a surface of the toner bearing member and configured such that the surface thereof is rotated to supply the toner to and develop a latent electrostatic image on a surface of a latent electrostatic image bearing member in a developing region which faces the latent electrostatic image bearing member; and a regulating member configured to regulate an amount of the toner to be moved towards the developing region, wherein the surface of the toner bearing member has regularly arranged convex portions, and wherein a non-electrostatic adhesive force between the toner and the surface of the toner bearing member is less than 9.0 nN.

Developing device and image forming apparatus including a toner bearing member having a predetermined relationship with toner

A development device includes a developer bearer to carry by rotation developer to a development range facing a latent image bearer, and a planar metal developer regulator to adjust an amount of developer carried by the developer bearer to the development range. The developer bearer includes a developer carrying range having surface unevenness, and the developer regulator includes a fixed end portion held by a regulator holder and a free end portion to contact a surface of the developer bearer.

Development device and image forming apparatus incorporating same

A development device includes a developer bearer to carry by rotation developer to a development range facing a latent image bearer and a developer regulator to adjust an amount of developer transported to the development range by the developer bearer. The developer bearer includes a developer carrying range having surface unevenness; and a surface of the developer bearer is coated with a coating material including a resin material and particles to roughen the surface.

Development device, and image forming apparatus and process cartridge incorporating same

An image forming apparatus includes a latent image carrier; a latent image writer to write a latent image on the latent image carrier; a developing unit including a toner carrier having first and second electrodes insulated via an insulator member and a voltage applying unit to apply voltages to the first and second electrodes having a potential difference to generate first electric fields to cause the toner to hop from the toner carrier to the latent image carrier to develop a toner image; and a transfer unit to transfer the developed toner image to a transferring member. When alternating voltages having a same phase and same amplitude are applied to the first and second electrodes to form second electric fields between the latent image carrier and the toner carrier, the toner is discharged from the toner carrier to the latent image carrier in a toner discharge mode.

Image forming apparatus

A development device includes a developer bearer to carry by rotation developer to a development range facing a latent image bearer, and a developer regulator to adjust an amount of developer transported to the development range by the developer bearer. Multiple projections are formed in a surface of the developer bearer, and, in a direction in which the developer bearer rotates, a downstream end of each of the multiple projections is higher than an upstream end of the projection.

A development device includes a toner carrier including first and second groups of electrodes, a toner supplier, and an electrical field generator. The electrical field generator includes a positive-phase pulse voltage generation circuit, a negative-phase pulse voltage generation circuit, a first DC power source for supplying a bias for setting a peak value of pulse voltages, a second DC power source to output a variable voltage having a polarity identical to a polarity of toner charge, a first diode having an anode connected to a lower potential side of the first DC power source and a cathode connected to an output terminal of the positive-phase pulse voltage generation circuit, and a second diode having an anode connected to the lower potential side of the first DC power source and a cathode connected to an output terminal of the negative-phase pulse voltage generation circuit.

Development device, process cartridge incorporating same, and image forming apparatus incorporating same

A development device includes a developer container, a rotary developer carrier that is disposed facing the latent image carrier and including multiple outer electrodes arranged in a circumferential direction of the developer carrier, an inner electrode electrically insulated from the multiple outer electrodes, an insulation layer disposed between the inner and outer electrodes, and a surface layer overlaying the outer electrodes and electrically insulating the multiple outer electrodes from each other, a bias power source to generate electrical fields that change with time by applying a first and second bias voltages to the inner and outer electrodes, respectively, an electrical field adjuster to regulate the electrical fields in accordance with a thickness of the surface layer of the developer carrier, and a controller.

A disclosed developing device includes a toner carrying member having electrodes, a toner supply unit supplying the toner to the toner carrying member, and a hopping electric field generator unit generating electric field to cause the toner hopping on the toner carrying member by applying a pulse voltage to the electrodes. The hopping electric field generator unit includes a pulse voltage generator circuit generating the pulse voltage, a first direct-current power source supplying bias to the pulse voltage generator circuit for regulating a peak value of the pulse voltage, and a second direct-current power source having a same polarity with a toner charging polarity, and outputting a variable voltage level. The hopping electric field generator unit controls the peak value of the pulse voltage by changing an output of the first power source and a mean thereof by changing an output of the second power source.

Developing device, process cartridge, and image forming apparatus

In a disclosed image forming apparatus, a developing bias applied to a developer carrier or exposure energy with which an image carrier is exposed is adjusted such that an isolated one-dot image on the image carrier has a predetermined image density. When the image carrier is exposed to form dot images continuously arranged in a main scanning direction, the exposure time period for each dot image is shorter than that when the image carrier is exposed to form the isolated one-dot image.

Image forming apparatus and image forming method which controls the exposing of an image carrier to change the exposure time period in the main scanning direction

A patch-pattern forming unit causes an image forming unit to form a patch pattern including a plurality of patches on a conveying member. A detecting unit detects the patch pattern formed on the conveying member. An adjusting unit adjusts an image forming condition of the image forming unit based on a result of detection by the detecting unit. The patch pattern has a length substantially equal to a distance between a patch-pattern start position, which is located at a space corresponding to at least a predetermined margin of a recording medium from a position of the image, and a position of the detecting unit.

Image forming apparatus, image forming method, and computer program product

A toner consumption-calculating apparatus includes a printed portion area-detecting unit that detects an area of a printed portion of image data of a latent image that is formed on a latent image-bearing member; a latent image portion area-detecting unit that detects an area of a latent image portion on the latent image-bearing member; and a latent image portion toner consumption-calculating unit that calculates latent image portion toner consumption that indicates toner amount that is consumed due to adhering on the latent image portion. The latent image portion toner consumption-calculating unit uses a detection result of the latent image portion area-detecting unit and a detection result of the printed portion area-detecting unit to calculate the latent image portion toner consumption.

Toner consumption-calculating apparatus, image forming apparatus, and toner consumption calculating method

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.

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Tokyo, Japan

Yoshiko Ogawa