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US 6,192,212 B1Granted
Image forming apparatus
AssigneeSharp Kabushiki Kaisha
InventorsHisashi Kunihiro, Takahiro Kimura, Akira Nakakuma
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AssigneeSharp Kabushiki Kaisha
InventorsHisashi Kunihiro, Takahiro Kimura, Akira Nakakuma
Estimating the term…
In image forming, the ratio of foreign substances mixed in the recycled toner which is removed from the photoreceptor drum surface by means of the cleaning device is computed as one of the characteristics of the recycled toner, based on the paper size, the image area and the transfer efficiency. If the recycled toner has a high ratio of foreign substances mixed therein and is determined to have a low quality, collection of the recycled toner into the developing unit is temporarily interrupted and a fixed amount of toner is conveyed from the developing unit to the cleaning device so as to improve the quality of the recycled toner. In this way, recycled toner of a low quality is prohibited from being used for subsequent image forming operations so as to prevent degradation of the image quality.
An image forming apparatus for forming images by electrophotography using a dual-component developer consisting of a toner and a carrier wherein the toner remaining on the photoreceptor surface after completion of the transfer step is removed by the cleaning device, collected and returned to the developing portion as the recycled toner and reused together with the fresh toner for a subsequent developing step,
Dependencies are inferred from the claim text.