| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device having excellent developing characteristics in all the density range from low density to high density. SOLUTION: This developing device 10 is equipped with a developing roller 12 carrying developer to a developing area 20 being the most proximate area to an image carrier 2. The roller 12 is constituted of a sleeve 14 carrying the developer held on its outer surface by its rotation and made of non-magnetic material, and a magnet roller 16 fixedly arranged inside the sleeve 14 and having plural magnetic poles including a developing magnetic pole 22 corresponding to the developing area 20. An area C being >=about 80% of a maximum value out of an area having magnetic attractive force B formed at the position of the magnetic pole 22 is formed from the upstream side to the downstream side of the opposed area D of the magnetic pole 22 in the rotating direction of the sleeve 14. |
