Printer RF line control

Claim 2

A printhead assembly comprising a printhead having any array of mutually spaced first and second electrode sets, each electrode of the first set crossing plural electrodes of the second set, control means for actuating an electrode of the first set together with a selected group of electrodes of the second set at locations corresponding to desired image points, and means for inhibiting actuating of the electrode of the first set when no electrodes of the second set correspond to desired image points.

Claim 3

An improved printhead drive controller for driving an electrographic printhead of the type having first and second sets of electrodes constituting an array of charge deposition loci defined by crossings of electrodes of said first and second sets, the electrodes of said first set being linearly extending electrodes which are energized at an energy to constitute sources of charge carriers and the electrodes of said second set extending transversely thereto and being energized with a control signal to selectively gate charge carriers from the sources to a recording member, such imProved printhead drive controller comprising first means for receiving a set of actuation signals corresponding to electrodes of the second set and determining whether at least one electrode of the second set is to be energized for gating charge carriers from the sources constituted by an electrode of the first set, and second means for inhibiting energizing the electrode of the first set when the first means determines that no electrode of the second set is to be energized.

Claim 4

An improved printhead drive controller for driving an electrographic printhead of the type having first and second sets of electrodes constituting an array of charge deposition loci defined by crossings of electrodes of said first and second sets, the electrodes of said first set being linearly extending electrodes which are energized at an energy to constitute sources of charge carriers and the electrodes of said second set extending transversely thereto and being energized with a control signal to selectively gate charge carriers from the sources to a recording member, such imProved printhead drive controller comprising first means for receiving a set of actuation signals corresponding to electrodes of the second set and determining whether at least one electrode of the second set is to be energized for gating charge carriers from the sources constituted by an electrode of the first set, and second means for inhibiting energizing the electrode of the first set when the first means determines that no electrode of the second set is to be energized.

Claim 5

The improved printhead drive controller of claim 2, wherein said first means comprises a plurality of logic gates which receive as inputs selection signals for selecting ones of said second electrodes and which develop an output signal therefrom, and said second means includes an AND gate which receives as inputs said output signal and an RF line enable signal to develop an RF output control signal, said RF output control signal being operative to energize the RF line.

Claim 8

A printhead assembly having improved lifetime, such assembly comprising a printhead having an array of mutually spaced first and second electrode sets, each electrode of the first set crossing plural electrodes of the second set control means for providing synchronized signals to actuate one electrode of the first set together with a selected group of electrodes of the second set, the selected group having crossing points corresponding to desired image points, said control means including plural high voltage switching elements for actuating ones of the electrodes of the first set, and having a characteristic lifetime, and means for preventing actuation of electrodes of the first set when no electrodes of the second set have crossing points corresponding to desired image points, thereby decreasing the number of switching cycles of said control means and increasing said lifetime.

Claim 9

A printhead assembly having improved lifetime, such assembly comprising a printhead having an array of mutually spaced first and second electrode sets, each electrode of the first set crossing plural electrodes of the second set control means for providing synchronized signals to actuate one electrode of the first set together with a selected group of electrodes of the second set, the selected group having crossing points corresponding to desired image points, said control means including plural high voltage switching elements for actuating ones of the electrodes of the first set, and having a characteristic lifetime, and means for preventing actuation of electrodes of the first set when no electrodes of the second set have crossing points corresponding to desired image points, thereby decreasing the number of switching cycles of said control means and increasing said lifetime.

Claim 10

A printhead assembly having improved lifetime, such assembly comprising a printhead having an array of mutually spaced first and second electrode sets, each electrode of the first set crossing plural electrodes of the second set control means for providing synchronized signals to actuate one electrode of the first set together with a selected group of electrodes of the second set, the selected group having crossing points corresponding to desired image points, said control means including plural high voltage switching elements for actuating ones of the electrodes of the first set, and the printhead being subject to aging as a result of such actuating and having a characteristic lifetime, and means for preventing actuation of electrodes of the first set when no electrodes of the second set have crossing points corresponding to desired image points, thereby decreasing the number of actuations of said first electrodes and increasing said lifetime.

Claim 11

A printhead assembly having improved lifetime, such assembly comprising a printhead having an array of mutually spaced first and second electrode sets, each electrode of the first set crossing plural electrodes of the second set control means for providing synchronized signals to actuate one electrode of the first set together with a selected group of electrodes of the second set, the selected group having crossing points corresponding to desired image points, said control means including plural high voltage switching elements for actuating ones of the electrodes of the first set, and the printhead being subject to aging as a result of such actuating and having a characteristic lifetime, and means for preventing actuation of electrodes of the first set when no electrodes of the second set have crossing points corresponding to desired image points, thereby decreasing the number of actuations of said first electrodes and increasing said lifetime.