| 摘要 |
PROBLEM TO BE SOLVED: To reduce the wear of the covering layer of a developing sleeve and to prevent toner from being splashed from both end parts of the developing sleeve. SOLUTION: An electrically conductive coating layer (covering layer) 1a is formed at the central part of the developing sleeve 1 in a longitudinal direction. The layer 1a is constituted of covering agent including electrically conductive grains, spherical grains whose number average size is 0.3-30μm and bonding resin. By the effect of the spherical grains, the strong layer 1a having uniform covering strength is obtained and the toner is prevented from being splashed caused by the wear of the layer 1a. By including the electrically conductive grains, the excessive electric charge of the toner can be made to escape by using the layer 1a as a leak site at a developing time. Thus, the lowering of density or a sleeve ghost or the like is prevented from occurring caused by the charge-up of the toner. |
