Abstract: A developing device includes a toner bearing member holding a toner on its surface for conveyance of the toner to a development region where the toner bearing member opposes an image bearing member via a predetermined gap therebetween; a regulating member pressed against the surface of the toner bearing member for regulation of the amount of toner conveyed to the development region; and a developing bias source for applying an alternating electric field between the toner bearing member and the image bearing member. The developing device features the use of the toner bearing member including a conductive substrate formed with an elastic layer, an intermediate layer and a surface layer on the surface thereof, respective volume resistances &rgr;1, &rgr;2 and &rgr;3 of which layers satisfy a condition &rgr;2≦&rgr;1≦&rgr;3, the toner bearing member having an arithmetic average surface roughness in the range of 0.8 to 2.5 &mgr;m, and the use of the toner having a volume-average particle size of 3 to 8 &mgr;m.

Abstract: A developing device of monocomponent development system for developing a latent image formed on an image bearing member according to the present invention includes a toner carrying member disposed opposite the image bearing member via a gap of 50 to 250 &mgr;m therebetween, and including a conductive substrate and an elastic layer having a rubber hardness of not more than 70 degrees and a thickness in the range of 7 to 50 &mgr;m, and a regulating member pressed against a surface of the toner carrying member for regulating the amount of toner on the toner carrying member.

Abstract: A developing device includes a toner bearing member holding a toner on its surface for conveyance of the toner to a development region where the toner bearing member opposes an image bearing member via a predetermined gap therebetween; a regulating member pressed against the surface of the toner bearing member for regulation of the amount of toner conveyed to the development region; and a developing bias source for applying an alternating electric field between the toner bearing member and the image bearing member. The developing device features the use of the toner bearing member including a conductive substrate formed with an elastic layer, an intermediate layer and a surface layer on the surface thereof, respective volume resistances &rgr;1, &rgr;2 and &rgr;3 of which layers satisfy a condition &rgr;2≦&rgr;1≦&rgr;3, the toner bearing member having an arithmetic average surface roughness in the range of 0.8 to 2.5 &mgr;m, and the use of the toner having a volume-average particle size of 3 to 8 &mgr;m.

Abstract: A developing device of monocomponent development system for developing a latent image formed on an image bearing member according to the present invention includes a toner carrying member disposed opposite the image bearing member via a gap of 50 to 250 &mgr;m therebetween, and including a conductive substrate and an elastic layer having a rubber hardness of not more than 70 degrees and a thickness in the range of 7 to 50 &mgr;m, and a regulating member pressed against a surface of the toner carrying member for regulating the amount of toner on the toner carrying member.