Kyocera Document Solutions Inc.

Ryo Yamada

Ikuo Makie

Yu Sasaki

Yuji Kamiyama

Tamotsu Shimizu

Akihiro Watanabe

Minoru Wada

Yasuhiro Tauchi

Yuji Toyota

Yukari Ota

Uto Syu

A developing device (-) is provided with a development container (), a first stirring conveyance member (), a second stirring conveyance member (), and a developer carrier (). The development container () has a first conveyance chamber (), a second conveyance chamber (), and a communication portion (). The first stirring conveyance member () includes a first rotation shaft () and a first stirring blade (). The second stirring conveyance member () includes a second rotation shaft () and a second stirring blade (). The developer carrier () is opposed to the second stirring conveyance member (). The first rotation shaft () includes, at least in a partial region in an axial direction of the first rotating shaft (), a tapered portion () of which a shaft diameter increases toward a downstream side in a developer conveyance direction in the first conveyance chamber ().

Developing device and image forming apparatus provided therewith

An image forming apparatus includes an image carrying member, a charging device, an exposure device, a development device, a development voltage power supply, a humidity detection device and a controller. The exposure device exposes the surface of the image carrying member charged by the charging device to form an electrostatic latent image. The development device includes a development container which stores a developer including a toner and a developer carrying member which supplies, to the image carrying member, the toner in the developer, and develops the electrostatic latent image into a toner image. The development voltage power supply applies, to the developer carrying member, a development voltage with an alternating voltage superimposed on a direct voltage. The humidity detection device detects an absolute humidity around the development device. The controller stepwise increases the frequency of the alternating voltage as the absolute humidity detected by the humidity detection device is increased.

Image forming apparatus

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, a first stirring member and a second stirring member, and a developing roller. The developing container includes a first stirring chamber, a second stirring chamber, and a communication portion. The first stirring member includes a reverse spiral vane that conveys a developer in a direction reverse to a circulation direction. An air discharge duct is formed on a wall portion of the first stirring chamber opposed to the reverse spiral vane and in an area excluding the communication portion and discharges air from the first stirring chamber to an outside of the developing container via an air discharge port at a distal end of the air discharge duct. A filtration portion is disposed in the air discharge duct adjacently to the air discharge port and restricts leakage of the developer through the air discharge port.

Developing device having air discharge duct and image forming apparatus including the developing device

A developing device includes a developer container, a developer carrier, and a stirring/conveying member. The developer container stores developer containing toner. The developer carrier carries on its surface the toner in the developer container. The stirring/conveying member includes a rotary shaft rotatably supported on the developer container and a stirring blade formed around the outer circumferential face of the rotary shaft and stirs and conveys the developer in the developer container. The stirring/conveying member to be used can be selected from a plurality of types of stirring/conveying members with rotary shafts with different shaft diameters.

Developing device allowing selection of a stirring/conveying member to be used from a plurality of types of stirring/conveying members with rotary shafts with different shaft-diameters and image forming apparatus therewith

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Osaka, Japan

Ryo Yamada