Apparatus for non-interactive electrophotographic development

Apparatus for non-interactive, dry powder development of electrostatic images on an image receiving member having an imageable surface with developer material including marking particles comprising:

• a housing containing developer material;
• a resonating donor member, spaced between 0.005″ and 0.015 from the image receiving member, for transporting marking particles to a development zone adjacent the image receiving member, said resonating donor member forming a cloud of marking particles in the development zone to develop said images, said resonating donor member includes a transducer element having a waveguide member attached thereto;
• and
• an AC power supply for providing an electrical bias to drive said transducer element, said AC power supply is adjusted so that said resonating donor member produces a toner cloud height between 0.005″ and 0.015″.