Model for a Mono-Component Development Process Using Edge Enhancement Effects of Floating Electrodes U

The contributions of the electrostatic field and the magnetic field to the development characteristics of a new mono-component development system are analyzed. This development system employs a special development roller which comprises 1) a development sleeve with a special structure consisting of an electroconductive substrate with a dielectric layer formed on the substrate having a number of small independent electrodes located at the surface of the dielectric layer, and 2) a magnet roller rotating at high speed within the development sleeve. The analysis indicates that the magnetic field has a significant effect only on the toner particles, which are charged helow a certain,level, hut the effect of the magnetic field on the toner particles, which are normally charged above a predetermined level, is negligible. Also, the analysis of the magnetic field indicates that the presently employed magnet roller, which rotates at high speed, can he replaced by a micropitch magnet roller, which rotates at low speed, since the same advantages obtained by the high-speed magnet roller can be obtained by the low-speed magnet roller. Furthermore, this analysis indicates that if the quantity of the electric charge on the toner particles can he controlled, a nonmagnetic toner can also he employed in the present development system. From these results a new idea for a further improved development system has been formed.