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US 6,578,940 B2Granted
System for ink short protection
AssigneeHewlett-Packard Development Company, L.P.
InventorsDavid A Rehmann, Steven B Elgee
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Abstract
A system for ink short protection for signaling to inkjet printheads includes a differential signaling driver having a first and a second terminal, a differential signaling receiver having a first and a second terminal, a first capacitor in series between the first terminals, a second capacitor in series between the second terminals, and circuitry for reducing charge accumulation on the capacitors. A method for ink short protection and a printing mechanism having such an ink short protection system are also provided.
Claims10
A printing mechanism, comprising:
- an inkjet printhead which selectively ejects ink;
- an ink short protection system for signaling to the inkjet printhead comprising:
- a differential signaling driver having a first and a second terminal;
- a differential signaling receiver having a first and a second terminal;
- a first capacitor in series between the first terminals;
- a second capacitor in series between the second terminals;
- passive circuitry for dissipating charge accumulated on the capacitors;
- and
- active circuitry for manipulating a data stream transmitted from the driver by steering current to the driver first terminal for a logic 1 data element and alternatively steering current to the driver second terminal for a logic 0 data element, whereby signals present on the first and second driver terminals tend to cancel the charge applied to the capacitors by previous signals.
6 more elements
Dependencies are inferred from the claim text.