Method and device for developing a toner image

摘要

In order to develop a toner image on a photoconductive substrate provided with a latent electrostatic charge image, a magnetic brush consisting of a multipole magnet core and a rotating sleeve surrounding the latter is provided. Situated on the sleeve is a uniform layer of an insulating, magnetic single-component toner having a layer thickness which is at least equal to the developing gap between the sleeve and the substrate. The magnet core is driven to rotate. In addition, a high-frequency AC voltage of more than 15 kHz is applied between the substrate and the magnetic brush.