| 摘要 |
PROBLEM TO BE SOLVED: To reduce a developer stuck to the convex part surface of a developer carrier and further to reduce surface staining by storing the developer supplied to the developer carrier in developer storage holes whose diameters on opening sides are larger than those on bottom surface sides. SOLUTION: Plural developer storage holes 20 for storing the developer are formed on the surface of a developer carrying roll 2 and the surface is rugged. The storage hole 20 is formed so that the diameter 20a on the opening side of the storage hole 20 is larger than the diameter 20b on the bottom surface side and further, on the opening side and bottom surface side of the storage hole 20, a large-diameter part 20c and a small-diameter part 20f are formed respectively. Thus, the opening side of the storage hole 20 of the developer carrying roll 2 has the large-diameter part 20c, to suppress a phenomenon that the developer stored in the small-diameter part 20f trickles down the wall of the hole 20 and oozes out in the contact part of an electrostatic latent image carrier drum with the projected part 2b of the carrying roll 2. Thus, the deterioration in image quality caused by the surface staining can be reduced. |
