Edge effect compensation in high frequency vibratory energy producing devices for electrophotographic imaging

In an imaging device having a non-rigid member with a charge retentive surface moving along an endless path, means for creating a latent image on the charge retentive surface, means for imagewise developing the latent image with toner, means for electrostatically transferring the developed toner image to a copy sheet, and a resonator for enhancing toner release from the charge retentive surface, producing relatively high frequency vibratory energy and having a portion thereof adapted for contact across the non-rigid member, generally transverse to the direction of movement thereof, the resonator comprising:

• an energy transmitting horn member, for applying high frequency vibratory energy to the non-rigid member, having a platform portion, a horn portion including a set of horn elements linearly arranged to extend across the non-rigid member, each horn element having a contacting portion for contacting the non-rigid member and responsive to a driving vibration, the set of horn elements including a first end subset at one end of the linear arranged horn elements, a second end subset at a distal end of the linear arranged horn elements, and a central subset including the remainder of the linearly arranged horn elements;
• a voltage source producing a voltage signal;
• a plurality of vibratory energy producing means to drive said horn member to vibrate, each vibratory energy producing means producing a vibration responsive to the voltage signal directed from said voltage source, to drive a corresponding horn element to resonance;
• each vibratory energy producing means corresponding to a horn element in the first end and second end subsets having a vibration response to said voltage signal directed thereto distinct from each vibratory energy producing means corresponding to a horn element in the central subset, to provide a substantially uniform vibration response to the applied voltage signal across the resonator.

A resonator adapted to vibrate a moving non-rigid member comprising:

• an energy transmitting horn member, for applying high frequency vibratory energy to a moving surface, having a platform portion, a horn portion including a set of horn elements linearly arranged across a length thereof, each horn element having a contacting portion for contacting a surface and responsive to a driving vibration, the set of horn elements including a first end subset, a second end subset and a central subset;
• a voltage source producing a voltage signal;
• a plurality of vibratory energy producing means to drive said horn member to vibrate, each vibratory energy producing a vibration responsive to the voltage signal directed to each from said voltage source, to drive a corresponding horn element to resonance;
• each vibratory energy producing means corresponding to a horn element in the first end and second end subsets having a vibration response to said voltage signal directed thereto distinct from each vibratory energy producing means corresponding to a horn element in the central subset, to provide a substantially uniform vibration response to the applied voltage