Patent ID: 8023866

Claim:
A marking apparatus comprising: a traveling wave grid toner transport circuit structure having in series a feed portion, a marking portion, and an recovery portion, wherein the portions have a generally continuous transport surface; the transport circuit structure being configured to transport a powdered toner cloud along the transport surface generally along a transport direction; a receiver having a receiver surface adjacent and separated by a gap from the transport surface of the marking portion of the transport circuit structure; a circuit for generating a projecting electric field in the gap between the receiver surface and the transport surface; a plurality of electromechanical transducers located in the marking portion of the transport circuit structure for selectively releasing patches of toner from the transport surface such that such released toner patches are projected across the gap by the projecting electric field; the traveling wave grid toner transport structure being configured to prevent toner from contacting the receiver surface except as to toner patches released by the electromechanical elements; and the projecting electric field being insufficient to cause transfer of toner to the receiver surface except when released by the electromechanical transducers.