| 摘要 |
PURPOSE:To alleviate mixing ratio detection error due to fluctuation of electrostatic charge of a developer in the early stage of operation by adjusting a mixing ratio of carrier particles of <=50mum average diameter and 0.5-2 times the diameter of toner particles to them. CONSTITUTION:The early stage fluctuation value of detection voltage V can be alleviated to <=1/2 of the conventional values by adjusting a mixing ratio of an oxidized reduced iron powder or ferrite carrier 12 having 30mum average particle diameter to a toner 13 of 20mum average particle diameter to 10:1-10:1. An image small in border effect on the border, high in density, and good in halftone reproducibility can be obtained by controlling an amt. of electrostatic charge of the toner to the range of 10-50muc/g. It is due to the fact that the high mixing ratio of the toner restrains the force of the carrier 12 adsorbing the toner 13 to render it not too much and increases development capability. A mixing state in the case of mixing the resin carrier 14 contg. the magnetic powder of 30mum average particle diameter with the toner 15 of 25mum average particle diameter is shown on the right, and a similar effect is obtained. |
