Patent ID: 7215909

Claim:
A developing device installable in an image forming apparatus having one end and another end, comprising: a developing roller supported by said developing device and adapted to develop a latent image formed on an electrophotographic photosensitive member; a developing blade adapted to regulate the thickness of a toner layer on said developing roller and provided so as to be in contact with said developing roller; a helical gear provided at one end of said developing roller in an axial direction thereof and adapted to transmit a driving force to said developing roller; a regulating portion provided at the another end of said developing device in the axial direction thereof so as to maintain the position of said developing roller in the axial direction thereof; urging means, which is provided at the one end of said developing device in the axial direction thereof, for urging said developing roller toward said regulating portion, and for urging said developing roller toward said regulating portion so as to maintain the position of said developing roller, wherein said urging means urges said developing roller in the same direction as a direction in which said helical gear urges said developing roller when the driving force is transmitted to said developing roller, wherein the urging force of said urging means is not less than double the weight of said developing roller.