| 摘要 |
PURPOSE: To prevent the occurrence of a defective image caused by the shaving of a developer supplying roller at the tie of driving a developing device, without increasing its initial torque by coating the surface of the developer supplying roller with specific powder. CONSTITUTION: This device is provided with a developing sleeve 110 for carrying a developer in a developing chamber 102 to a developing region and the developer supplying roller 112 which is rotatable and brought into contact with the developing sleeve 110. The surface of the supplying roller 112 is provided with the powder not having any chargeability or the powder charged to the same polarity as that of the developer and having the absolute value of the chargeability equal to or less than that of the developer. For instance, the supplying roller 112 consisting of a polyurethane foamed body having 80 foamed cells (piece/25mm) is filled with toner 201 and as the toner in the developing chamber 102, only the toner 102 coating the supplying roller 112 is provided. Thus, static torque is reduced to half that when the supplying roller 112 does not have any coating and the generation of a void streak is prevented in the formation of an image as well. |
