Kyocera Document Solutions Inc.

Yohei Wakasa

Tamotsu Shimizu

Kazuhiro Nakachi

Takahiro Okubo

Mitsuhiro Hashimoto

Keiya Nishimura

In the image forming apparatus, a controller applies a collection voltage to a cleaning roller by a voltage application part in image formation process. The controller adjusts the collection voltage applied to the cleaning roller on bases of uncollected toner quantity of a toner image and residual charge of an image carrier, the uncollected toner being part of after-transfer remaining toner which results after formation of the toner image on an outer circumferential surface of the image carrier and transfer of the toner image onto a transfer-objective member, and which has missed being collected by the cleaning roller so as to remain even after one-round rotation of the image carrier.

Image forming apparatus

Provided is an image forming apparatus having a simple configuration capable of measuring a toner current included in a developing current and accurately calculating a toner charge amount based on the measurement result. The developing device has a developer carrier that carries a two-component developer including a magnetic carrier and toner. The density detecting device detects the density of the toner image. The current detecting unit detects a DC component of a developing current that flows when a developing voltage is applied to the developer carrier. The control unit, in a state in which the image carrier is rotated at two or more different linear speeds during non-image formation, forms the same reference image on the image carrier by the developing device, and estimates the toner charge amount based on the developing current when the reference image is formed and the density of the reference image.

Image forming apparatus using two-component developer including toner and carrier that determines toner charge amount based on a developing current

Provided is an image forming apparatus having a simple configuration capable of measuring a toner current included in a developing current and accurately calculating a toner charge amount based on the measurement result. A developing device has a developer carrier that carries a two-component developer including a magnetic carrier and toner. A developing voltage power supply applies a developing voltage obtained by superimposing an AC voltage on a DC voltage on the developer carrier. A control unit estimates a toner charge amount based on a toner current calculated by subtracting a carrier current from a developing current detected by a current detecting unit when a reference image is formed during non-image formation, and a toner developing amount calculated from the density of a reference image detected by a density detecting device.

Image forming apparatus having simple configuration and capable of measuring toner current included in developing current, and accurately calculating toner charge amount based on measurement result

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Osaka, Japan

Yohei Wakasa