Marking head for fluid jet assisted ion projection imaging systems

Claim 1

A fluid jet assisted electrographic marking apparatus for placing electrostatic charges upon a charge receptor surface in an image-wise pattern, including means for supplying a transport fluid, housing means including an upstream ion generation region and a downstream ion modulation region, said housing means including inlet means for receiving transport fluid from said means for supplying, located upstream of said ion generation region, ion modulation means located at said ion modulation region, and outlet means from which transport fluid exits said housing, said ion modulation means being characterized by comprising charge storage means, comrising electrically conductive electrodes positioned adjacent the path of said transport fluid in said ion modulation region, for controlling the passage of ions out of said housing, said charge storage means being divided into sections, charging means for applying predetermined voltages to said sections in accordance with said image-wise pattern, means for selectively and sequentially coupling said charge storage means in a given section to said charging means and for isolating non-selected sections from said charging means, whereby said charge storage means in a given section are brought to the predetermined voltage when coupled and hold the predetermined voltage when isolated, for controlling the passage of ions out of said housing, and said electrodes, said charging means and said means for selectively and sequentially coupling are thin film elements integrally fabricated upon a substrate.