| 摘要 |
PURPOSE:To facilitate the increase of the charged electrostatic charging quantity of a developer by preventing a developer carrying member from traversing the fluidized bed of the developer. CONSTITUTION:A developer T close to a developing roller 5 in the fluidized bed 17 is magnetically restrained and is pushed up toward a magnetic blade 11 by rotation of the developing roller 5 and is inverted and flows down and is moved upward again in the position of a magnetic pole 9c by the rotating force of the developing roller 5 and passes the same process and is circulated in the fluidized bed 17 by convection. During this convection, the developer T is charged by friction due to rotation of the developing roll 5 or rubbing between developer particles, and its electrostatic-charging quantity is increased and held. Since the developer in the fluidized bed 17 is moved up to a part under a line l, the developer T which is led from the bottom of a vessel 1 to a point P by a rod material 27 and has a small-charged electrostatic charging quantity is taken into the fluidized bed 17. Thus, the electrostatic charging quantity of the developer T in the fluidized bed 17 is not reduced because an agitating rod 23 and the rod material 27 do not traverse the fluidized bed 17. |
