Patent ID: 6999691

Claim:
A developing device used with an electrophotographic image forming apparatus having a photosensitive body, the developing device comprising: a toner transfer body which supplies toner to the photosensitive body having an electrostatic latent image formed thereon; a supplying member which supplies the toner to the toner transfer body; and a power supplying unit which applies a developing bias and a supplying bias formed by overlapping a DC potential on an AC potential to the toner transfer body and the supplying member, respectively and which varies the developing bias and the supplying bias simultaneously according to a first wave pattern to generate a first electric field to be applied to the toner transfer body and the supplying member to supply the toner to the toner transfer body when a development operation is performed, and varies the developing bias and the supply bias simultaneously according to a second wave pattern to generate a second electric field to be applied to the toner transfer body and the supplying member to remove the toner from the toner transfer body when the development operation is not performed.