Patent ID: 8050602

Claim:
A developing device, which visualizes an electrostatic latent image on an electrostatic latent image-supporting member by using a developer containing a toner and a carrier, comprising: a developer that contains a toner and a carrier so that the toner is charged to a first polarity, while the carrier is charged to a second polarity that is different from the first polarity, by mutual frictional contact between the toner and the carrier; a first transporting member placed at an opening portion of a developer vessel used for housing the developer; a second transporting member that faces the first transporting member with a first area interposed therebetween, and also faces an electrostatic latent image-supporting member with a second area interposed therebetween; a first electric-field-forming unit used for forming a first electric field between the first transporting member and the second transporting member so that the toner in the developer held by the first transporting member is transferred onto the second transporting member; and a second electric-field-forming unit used for forming a second electric field between the second transporting member and the electrostatic latent image-supporting member so that the toner held by the second transporting member is transferred onto the electrostatic latent image on the electrostatic latent image-supporting member to visualize the electrostatic latent image, wherein the first electric field, formed between the first transporting member and the second transporting member, includes at least an ac electric field, and the second transporting member has a surface that is charged to the same polarity as the charged polarity of the toner by friction-contact with the carrier, and a volume resistance value of 1×10 3 to 1×10 9 (Ω).