| 摘要 |
PROBLEM TO BE SOLVED: To prevent a ghost as a history of an image remaining on a developing sleeve from appearing, to make the excellent image possible to be formed, and to eliminate the problems of the developer deterioration, the scratch occurrence on the developing sleeve, deficient charge quantity of the developer, lowering of the image density, the increase in color mixture derived from being left standing, and deterioration of fine line reproducibility, or the like. SOLUTION: Relating to this developing device a paddle wheel 44 is arranged so that the least proximate range A (mm) between a periphery of the developing sleeve 41 and rotary locus of a paddle wheel 44, and carrier's volume average grain size D (μm) satisfies the next relational expression, D<=A<=150×D, and the common normal (n) that connects a rotary shaft center of the developing sleeve 41 and the rotary shaft center of a paddle wheel 44, lines in the range of setting angle 10 deg. to 90 deg. toward the direction of gravity at an angle (ψ) with respect to the horizontal line (m) crossing the rotary center of the developing sleeve 41. |
