Abstract: Various configurations and applications of traveling wave grids are disclosed. Systems for transporting particles to feed apertures, and/or for transporting particles from storage reservoirs are described. The systems are particularly useful for transporting toner particles in printing systems.

Abstract: A transfer belt apparatus, system and method are provided to prevent image blooming. For example, an ink jet printing apparatus may include a grounded print head, a counter-electrode opposite the ground print head, and a bi-layer transfer belt provided between a print head and a counter-electrode and at least partially supported by two or more transfer bias rollers. A method may include applying a voltage between a print head and a counter-electrode to accelerate ink drops coming out of the print head toward a transfer belt, and evacuating charge accumulated on the transfer belt with a time constant smaller than a drop ejection frequency of the print head.

Abstract: A toner gating apparatus for supplying toner through an aperture to a gas channel having a propellant stream. The toner gating apparatus has a traveling wave grid having electrodes. A first gating electrode is located proximate a first side of the aperture. A second gating electrode is located proximate a second side of the aperture. A third gating electrode is located in the gas channel. A first voltage source having a first phase is connected to both the first gating electrode and a first electrode of the travelling wave grid. A second voltage source having a second phase is connected to both the second gating electrode and a second electrode of the travelling wave grid. A third voltage source having a third phase is connected to both the third gating electrode and a third electrode of the travelling wave grid.