| 摘要 |
PURPOSE:To allow the decision of the presence or absence of abnormality and more particularly the accurate and easy judgment of the presence or absence of the mechanical and electrical abnormality from the inside of a developing device to the photosensitive body or further the abnormality in the section having influence on image formation such as deterioration, etc., of developer with the device using a two-component developer consisting of a combination of a high-resistance or insulating toner and a conductive carrier. CONSTITUTION:The developer consisting of at least the carrier subjected to a conduction treatment on at least the surface thereof and the high-resistance or insulating toner is used for the developer of the device disposed with a toner carrying member deposited with the developer on the front surface side of the photosensitive body 1 and an exposing means on the rear surface side of the photosensitive body, respectively. A friction area 10 is formed at just before the start of exposing and a developing bias Vi including at least a constant voltage DC component is impressed to the photosensitive body 1 side from the toner carrying member via the friction area 10 and the adequateness or inadequateness of the image formation is judged in accordance with the detection signal taken out of the photosensitive body 1 side. |
