Konica Minolta Business Technologies, Inc.

Konica Minolta, Inc.

Konica Corporation

Seiko Itagaki

Hiroshi Akita

Natsuko Minegishi

Hiroyuki Saito

Isamu Miura

Kunio Shigeta

Naoki Tajima

Tatsuya Furuta

Kazuhiro Saito

Kazuteru Ishizuka

Tomohiro Kawasaki

Kazutoshi Kobayashi

Shunichi Takaya

Ryoei Ikari

Seiji Yamaguchi

Toru Komatsu

Disclosed herein is a developing device including: a developer housing section configured to house a developer including toner and carrier; a carrier replenishing section configured to supply the carrier to the developer housing section; a carrier concentration detecting section provided at a position near a carrier replenishment position at which the carrier is received from the carrier replenishing section in the developer housing section, the carrier concentration detecting section being configured to detect a carrier concentration in the developer housing section; and a carrier replenishment determination section configured to determine whether the carrier is properly supplied to the developer housing section on the basis of a result of detecting by the carrier concentration detecting section.

Developing device and image forming apparatus

In an image forming apparatus including an image carrier, a developing device which uses a developer including a toner and a carrier and to develop the electrostatic latent image and forms a visible toner image, plural toner supplying devices each of which supplies the toner in which mass ratio of an additive against the toner is different, and a control section which controls a ratio of a toner supplying amount to be supplied from each of the plural toner supplying devices, under a condition that toner consumption per a single print is low, the control section is configured to increase the toner supplying ratio of the toner including a high ratio of the additive, and under a condition that the toner consumption per the single print is high, the control section is configured to decrease the toner supplying ratio of the toner including a high ratio of the additive.

Image forming apparatus

A lubricant coating device related to the present invention is characterized in that it comprises a lubricant supply unitwhich supplies a lubricantonto an outer peripheral surface of an image carrierthat is driven to rotate and a lubricant smoothing unitwhich is disposed on the downstream side in a rotating direction of the image carrierof the lubricant supply unitand smoothes the lubricantsupplied onto the outer peripheral surface. In the lubricant coating device, the lubricant smoothing unitrotates while being in surface contact with the outer peripheral surface of the image carrierand thereby smoothes the lubricantsupplied onto the image carrierby the lubricant supply unit

Lubricant coating device and image forming apparatus

A developing device, includes a developer agitating member, an upstream side developing roller, and a downstream side developing roller; wherein a toner in a developer handed over from the upstream side developing roller to the downstream side developing roller has a volume average particle size larger than a volume average particle size of the toner in the developer conveyed by the upstream side developing roller to the facing position between the upstream side developing roller and a photoreceptor drum.

Developing device with bias voltage and image forming apparatus

A carrier removing apparatus, including: an electrode, having a plurality of openings through which a carrier passes, disposed to oppose an image carrier, and a power source to apply a voltage onto the electrode so as to separate the carrier on the image carrier from the image carrier, wherein the electrode has a surface along a surface of the image carrier.

Carrier removing device and image forming apparatus

An image forming apparatus includes: an image carrier; a latent image forming device; a developing device; an electrode which faces to the image carrier; an electric power source, a toner contamination detecting device for detecting toner contamination onto the electrode; an electrode cleaning device for cleaning the electrode; and a controlling section. The control section controls the electric power source to apply at least an alternating current voltage to the electrode so that toner image is rearranged by reciprocally moving toner of the toner image between the image carrier and the electrode control section and allows the electrode cleaning device to clean the electrode when the toner contamination detecting device detects toner contamination on the electrode, and performs the toner rearrangement by the electrode from which the toner contamination is removed.

Image forming apparatus with a toner contamination detecting device

The present invention realizes an image forming apparatus which is equipped with a carrier recovery section of simple configuration and for which maintenance is not required, the apparatus includes: a photoconductive drum; a developing device to develop a latent image formed on the photoconductive drum by a two-component developer containing a toner and a magnetic carrier, and a carrier recovery section which is equipped with a recovery roller, wherein the carrier recovery roller includes a rotatable sleeve, and a magnet roller that is installed inside the sleeve and provided with a plurality of fixed magnetic poles including a main pole to recover the magnetic carrier adhered onto the photoconductive drum and a separating pole to separate the magnetic carrier from the recovery roller, wherein a separating member is disposed at such a position that is opposite to the sleeve at a prescribed distance in a non-contact state.

Provided is a developing device which can prevent the occurrence of a phenomenon of an excessive increase of a developer quantity in a developer standby space, thereby acquiring a stable image. The developing device comprises a developer agitation-transfer unit, a developer roller, a developer feeding roller, a developer guide member and a space forming member. The developing device is characterized in that the developer feeding roller rotates to transfer the developer transferred by the agitation-transfer means, upward from the clearance between the developer feeding roller and the developer guide member, and in that, when the developer standby space formed in the device is filled with the developer transferred by the developer feeding roller, the developer feeding roller is rotated to carry the developer, which overflows from the developer standby space, and to move the same in the direction away from the developer roller, so that the developer is once discharged from the developer standby space.

Developing device

Provided is a developing device employing a two-component developer where a good image can be obtained by preventing the influence of scratching caused by a magnetic brush. A developing device comprises a first develop roller () for developing an electrostatic latent image, formed by the two-component developer on an image carrier (), in a first development area (n), and a second develop roller () for carrying toner supplied from the first develop roller () on the outer circumferential surface and developing the electrostatic latent image on the image carrier () in a second development area (n) on the downstream side of the first development area (n) in the rotational direction of the image carrier (), wherein the moving direction of the outer circumferential surface of a sleeve (A) is reverse to the moving direction of the surface of the image carrier () in the first development area (n), and a position (n) at which to supply toner from the first develop roller () to the second develop roller () is locate downstream of a regulation position (n) in the rotational direction of the first develop roller and upstream of the first development area (n).

An image forming apparatus includes: a supplying section for supplying developer; a first developing roller including plural magnetic poles and a first sleeve arranged rotatable to the first developing roller; a second developing roller including plural magnetic poles and a second sleeve arranged rotatable to the second developing roller, the second developing roller arranged adjacent to the first developing roller and parallel to the same; an electrode arranged between the first and second developing rollers; and a voltage applying unit for applying bias voltages each having different electric potential corresponding to the first developing roller, the second developing roller and the electrode, wherein an absolute value of the bias voltage to be applied to the electrode is larger than that of the bias voltage to be applied to the first developing roller and smaller than that of the bias voltage to be applied to the second developing roller.

Image forming apparatus with two developing rollers, and an electrode therebetween

Described is a developing roller, which makes it possible to appropriately peel developer off the developing roller, even if the developing roller is a small-sized. The developing roller includes a non-magnetic developing sleeve and a magnetic member installed into an inner space of the developing sleeve and having plural magnetic poles including a peeling magnetic pole. When a reference position is defined as such a position that exhibits a maximum value of magnetic flux density to be generated in a normal direction by the peeling magnetic pole, a magnetic-flux density flat region within which the magnetic flux density is kept at substantially a constant value being closely approximate to the maximum value of the magnetic flux density and the reference position is included, exists while fulfilling an Equation indicated as follow:&#x2267;7&#xb0;

Developing device, image forming apparatus and developing roller

A developing apparatus, comprises an endless belt shaped donor member; a developer supporting member to carry developer including toner and magnetic carrier and to form a toner layer on the donor member; a first supporting member arranged in the inside of the donor member with a predetermined gap against the developer supporting member and to strain the donor member; a second supporting member arranged in the inside of the donor member with a predetermined gap against the developer supporting member and to strain the donor member; a toner supply bias applying section to apply onto the first supporting member a toner supply bias for supplying toner from the developer supporting member to the donor member; and a toner recovery bias applying section to apply onto the second supporting member a toner recovery bias for recovering toner from the donor member to the developer supporting member.

Developing device, process unit, and image forming apparatus

An image forming apparatus includes: an image carrying body; a latent image forming unit to form an electrostatic latent image on the image carrying body; a developing unit to develop the electrostatic latent image on the image carrying body to form a toner image, the developing unit including a developing agent carrying body to carry a developing agent in a development region, and a direct-current power supply and an alternating-current power supply, both applying a developing bias voltage to the developing agent carrying body, the developing bias voltage generated by superimposing a direct-current voltage to an alternating voltage; a printing rate detecting unit to detect a printing rate; and a control unit to control the alternating-current power supply, wherein the control unit controls an output of the alternating-current power supply based on a detection result of the printing rate detecting unit.

Image forming apparatus which suppresses selective development of toner

There is described an image forming apparatus for forming a high-density image by using the reversal developing method and suppressing an occurrence of irregularities. The apparatus includes an image bearing member, a latent image forming device to form an electrostatic latent image, a magnetic field generating device to generate a magnetic field and a developing device to develop the electrostatic latent image so as to form a toner image on the image bearing member. At a developing region, the developer bearing member moves in a direction opposite to a moving direction of the image bearing member and the magnetic field generating device has a developing pole to form a magnetic brush for developing the electrostatic latent image. Further, an outer diameter R (mm) of the developer bearing member and a magnetic flux density Br(mT) of the developing pole fulfill the relationship of Br&#x2267;R&#xd7;4.5.

An image forming apparatus includes: a developing device which applies a developing bias voltage obtained by superimposing an AC bias voltage onto a DC bias voltage to a photoreceptor, and develops a latent image on the photoreceptor with a developer to form a toner image. The apparatus has a toner forced discharge mode for forming a toner image for forced discharge in a first image formation area provided in a non-image formation area other than a second image formation area on the photoreceptor to forcibly discharge a toner from the developing device. When the mode is selected, an AC bias voltage at a frequency lower than that in the second image formation area is applied to the first image formation area to develop a latent image for forced discharge, to form a toner image, and a toner of the toner image is collected by a cleaning device.

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Hachioji, Japan

Seiko Itagaki