| 摘要 |
PURPOSE:To prevent uneven density, by setting a secondary upper limit value lower than a primary upper limit value for either of a primary or secondary current. CONSTITUTION:Electric charging currents of a primary charger 2, and a secondary charger 3 detected with a sensor 7 are fed to a micro CPU 15 and controlled so as to converge them to each aimed value. A secondary upper limit value lower than a primary upper limit value set from the dielectric breakdown value, etc. of a photosensitive drum and the chargers is set in either of the primary or secondary charging current. Both of the primary and secondary charging currents are lowered by setting such an upper limit value and the synergistic effect of control of the primary and secondary currents and defect of causing uneven density due to dusted wires is eliminated, thus preventing uneven density. |
