| 摘要 |
PROBLEM TO BE SOLVED: To prevent an unevenness in density due to the difference of a distance from a developer penetrating hole corresponding with each first electrode, to the external surface of a developer feeding roller by making the diameter of the developer penetrating hole at an area which penetrates an insulation layer, larger, as the distance from the developer feeding roller becomes larger. SOLUTION: Toner penetrating holes 23 which correspond with first electrodes 21 for the first stage - eighth stage, are made first - eighth toner penetrating holes 23. Each toner penetrating hole 23 is constituted of a hole 23a which is made on the first electrode 21, a hole 23b which is made on a second electrode 22, and a hole 23c which is made on an insulation layer 20. In this case, as the toner penetrating hole 23 becomes away from a line L connecting the axial center of a toner feeding roller 1 and the axial center of a base roller, the diameter of the hole 23c being formed in the insulation layer 20 is made larger. In other words, as the distance from the toner penetrating hole 23 to the toner feeding roller becomes larger, the diameter of the hole 23c being formed on the insulation layer 20 is made larger. |
