Patent ID: 6985685
Filing Date: 2006-01-10
Classification: G03G

Abstract:
1. A developing device comprising: (a) a rotary developer carrier facing a latent image carrier for carrying a developer comprising a toner and a carrier; (b) a rotary developer supply and collection member for supplying the developer to and collecting from the developer carrier; (c) a first rotary developer stirring member for stirring the developer while conveying and circulating the developer; (d) a second rotary developer stirring member for stirring the developer while conveying and circulating the developer between the first and second developer stirring members, wherein the developer carrier, the developer supply and collection member, the first developer stirring member and the second developer stirring member are arranged in a housing in parallel with each other in this order in a direction leaving the latent image carrier, and wherein conveyance directions of the developer of the first and second developer stirring members are opposite to each other with respect to rotary axis directions thereof, and conveyance power for the developer thereof is substantially identical to each other; (e) a third rotary developer stirring member for stirring the developer, having a length in a rotary axis direction smaller than that of the second developer stirring member and a conveyance power for the developer in a rotary axis direction that is substantially zero, provided facing the second developer stirring member at a position corresponding to an upstream portion of and farther than the second developer stirring member in the housing; and (f) a toner replenishment inlet through which a new toner is replenished, provided in the housing at an upper position of a part where circumferential surfaces of the second and third developer stirring members face each other, and on an upstream side in the conveyance direction of the developer of the second developer stirring member, wherein the third developer stirring member is rotated so that the circumferential surface thereof moves downward in the same direction as that of the circumferential surface of the second developer stirring member at the position where the circumferential surfaces of the second and third developer stirring members face each other.