| abstract |
To form an irregularity-free thin layer of developer on a developer supporting member, the surface of the developer supporting member is formed with concavo-convexities along the conveyance direction thereof. To eliminate any irregularity of the developer layer on the developer supporting member and to sufficiently impart charge to the developer by the friction between the developer and the supporting member, the concavo-convexities should preferably have a pitch of 5-100μ, a concavity depth d of 0.2-10μ and a concavity width W of 2d-3d. The concavo-convexities should desirably be rounded rather than sharp. |