Kyocera Document Solutions Inc.

Shizuka Ikazaki

Tamotsu Shimizu

Akihiro Watanabe

An image forming apparatus includes an image carrier, a developer carrier, a bias applying section, a leakage detecting section, and a bias controlling section. The developer carrier carries developer in the form of a layer of magnetized filaments to supply toner to the image carrier. The bias applying section applies to the developer carrier a development bias including a direct current voltage VmagDC and an alternating current voltage VmagAC superposed on each other. The leakage detecting section causes a discharge between the image carrier and the developer carrier and detects a leakage voltage when the discharge occurs. The leakage detecting section performs the leakage voltage detection in a blank region of the image carrier bearing no electrostatic latent image. The bias controlling section determines an alternating current voltage VmagAC according to a detected leakage voltage, and a frequency of the alternating current voltage VmagAC according to the voltage VmagAC.

Image forming apparatus with function of setting appropriate development bias

A developer container includes a container housing for storing developer, a cylinder section projecting from the container housing and including a developer discharge port, and a rotary member for conveying the developer to the discharge port. The rotary member includes a rotary shaft rotatably supported and having a first part located in the container housing and a second part located in the cylinder section, and a resilient member projecting from the second part of the rotary shaft in a radial direction of rotation of the rotary member and facing the developer discharge port. The resilient member includes a tip end operable to protrude radially outward out of the developer discharge port after rubbing an inner surface of the cylinder section as the rotary shaft of the rotary member makes rotation.

Developer container and image forming apparatus including the same

A developing device includes a development housing, a developer carrier, a toner carrier, a bias applying unit, a leakage detecting unit, a bias control unit and a leakage detection control unit. The developer carrier carries a developer layer. The toner carrier receives the toner from the developer layer and supplies the toner to an image carrier. The bias applying unit includes one transformer and applies direct-current voltages and alternating-current voltages to the developer carrier and the toner carrier. The leakage detecting unit detects leakage occurring between the image carrier and the toner carrier or between the toner carrier and the developer carrier. The leakage detection control unit detects a value of an inter-peak voltage, at which the leakage occurs, by applying the same direct-current voltage to the toner carrier and the developer carrier and changing the inter-peak voltages of the alternating-current voltages.

Developing device and image forming apparatus provided with same

A developing device includes a development housing, a developer carrier, a toner carrier, a bias applying unit, a leakage detecting unit, a bias control unit and a leakage detection control unit. The developer carrier carries a developer layer. The toner carrier receives the toner from the developer layer and supplies the toner to an image carrier. The bias applying unit includes one transformer and applies direct-current voltages and alternating-current voltages to the developer carrier and the toner carrier. The leakage detecting unit detects leakage occurring between the image carrier and the toner carrier or between the toner carrier and the developer carrier. The leakage detection control unit detects a value of an inter-peak voltage at which the leakage occurs and determines whether the leakage occurs between the image carrier and the toner carrier or between the toner carrier and the developer carrier.

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Osaka, Japan

Shizuka Ikazaki