| 摘要 |
PURPOSE:To eliminate reverse fogging due to the backward motion of toner which is charged negatively and electrostatically by accurately controlling the electrostatic charge amount and saturated magnetism of toner on a toner carrier. CONSTITUTION:A bias from a bias power source 8 is applied between a sleeve 4 and an electrostatic image holder 1 to transfer toner 7 to an electrostatically charged part on the surface of the electrostatic image holder 1. In this case, a cylindrical sleeve which contains a fixed magnet of 750 - 1,000 gauss is applied with an AC bias of 200 - 4,000Hz in frequency and 500 - 3,000V in peak-to-peak value and a +100 - +300V DC bias and rotated at a >=600mm/s sleeve peripheral speed to perform development without contacting by using negative electrostatically single-component magnetic toner of 30 - 40emu/g in saturated magnetism containing 0.05 - 10wt.% negative electrostatically charged particulates of -5 - -300muc/g in triboelectric charge quantity and 5 - 30mmu in primary mean particle size. Consequently, no reverse fogging due to the backward motion of the negative electrostatically charged toner is caused. |
