| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a developing device can prevent occurrence of a developing history phenomenon by improving developability of toner for a developing roller and collecting property of development residual toner on the developing roller, and an image forming apparatus including the same. <P>SOLUTION: In the developing devices 3a to 3d, a first N pole 41a is provided at an opposed position to the developing roller 23 inside the magnetic roller 22, and a third S pole 43a arranged at the above opposed position and a fourth S pole 43b arranged adjacently to an upstream side of the third S pole 43a in a rotating direction of the developing roller 23 are provided inside the developing roller 23. The fourth S pole 43b is formed so that its magnetic flux density in a normal direction may be larger than that of the third S pole 43a. <P>COPYRIGHT: (C)2011,JPO&INPIT |
