摘要 |
An electrographic printing system moves a dielectric imaging member past a charge transfer print cartridge or bulk charging source, and a landing electrode arrangement directs charged particles with enhanced precision to dot positions on the imaging member. The arrangement includes a central, point-like, target electrode and a field electrode that, together with the target electrode, provides a corrective electric field component to form a focusing, or at least a non-diverging field over the target position. Field deflection artifacts such as "venetian blinding" are substantially corrected. The target electrodes are located behind the imaging member, in registry with the charging cartridge which is opposed to the other side of the member. Different landing electrode arrangements may include one- or two-dimensional arrays of targeting electrodes and are adapted to either bulk or pointwise arrays of charge emitter. Two dimensional imaging may be performed by timed actuation of landing electrodes using a charged particle source that is always ON, by multiplexing the print cartridge electrodes, or multiplexing some electrodes of each of the two structures at a lower rate. A self-limiting feedback loop assures charge dot saturation without image distortion.
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