Patent ID: 8139990

Claim:
A developing device comprising: a housing in which nonmagnetic one-component toner is housed; a developing roller which horizontally extends in an opening of the housing; a feed roller which is set in the housing parallel to the developing roller in pressure contact with the developing roller so as to form a first nip portion and which is rotated in a direction equal to a rotational direction of the developing roller so as to feed toner to the developing roller; and a feed stabilizing member which is placed within the housing and is in contact with an upstream-side portion of the feed roller lower than the first nip portion, the upstream side being referred to along the rotational direction, so as to form a second nip portion, and which restricts toner feed quantity from the feed roller to the developing roller, the feed stabilizing member being provided so as to extend from a generally triangular-shaped first region, which is surrounded by a portion of the developing roller lower than the first nip portion and a portion of the feed roller lower than the first nip portion, to one side of the second nip portion opposite to the first region side; and a toner circulation path as a path where toner is pushed back from the first region through below the feed stabilizing member to a second region corresponding to a place upper than the feed stabilizing member on the one side of the second nip portion opposite to the first region side with an aid of pressure of toner that tends to accumulate in the first region.