| 摘要 |
PURPOSE: To provide a developing device obtaining a developed image where the sticking of developer to a non-image part is prevented and whose sharpness is excellent by controlling the occurrence of developer having reverse polarity at the time of a developing operation as much as possible. CONSTITUTION: A supply roller 24 is constituted of a member whose surface is at least elastic or flexible and also where toner is normally electrostatically charged on triboelectrification system series, and is disposed so as to be brought into contact with a developing roller 23 or to be deformed by a specified amount in the radial direction from the developing roller 23, and also is disposed so as to be brought into contact with the wall surface of a developing device casing 22 opposed to the supply roller 24 on the upstream side of the carrier direction of the toner positioned at the lower part of a gravity direction from a position where the supply roller 24 and the developing roller 23 are brought into contact or to be deformed by the specified amount in the radial direction from the wall surface. Thus, the toner which is insufficiently electrostatically charged or which is reversely electrostatically charged is reduced, so that only the toner normally electrostatically charged contributes to developing. |
