Patent ID: 8095026

Claim:
A developing device, comprising: a developer container for containing developer including toner and carrier; a toner-supplying developer supporting member for supporting on a surface thereof, the developer in the developer container to convey the developer; a toner supporting member for supporting toner received from the toner-supplying developer supporting member and conveying the toner to develop an electrostatic latent image on an image supporting member; a toner-collecting developer supporting member for collecting a post-development residual toner from the toner supporting member; a first bias power supply for applying a first bias voltage to the toner-collecting developer supporting member to form a first bias electric field between the toner-collecting developer supporting member and the toner supporting member in a direction in which toner is transferred to the toner supporting member; and a second bias power supply for applying a second bias voltage to the toner-supplying developer supporting member to form a second bias electric field between the toner-supplying developer supporting member and the toner supporting member in a direction in which toner is transferred to the toner supporting member, wherein an average of a voltage of the toner-collecting developer supporting member in reference to the toner supporting member has the same polarity as and a smaller absolute value than an average of a voltage of the toner-supplying developer supporting member in reference to the toner supporting member, and wherein a toner collecting capability for the toner-collecting developer supporting member to collect toner from the toner supporting member is higher than a toner collecting capability for the toner-supplying developer supporting member to collect toner from the toner supporting member.