Ink flow heat exchanger for inkjet printhead
First Claim
Patent Images
1. A printing device comprising:
- a substrate having a front surface for facing a medium to be printed upon, said substrate having a back surface;
a plurality of ink election chambers on said front surface which define cavities for receiving ink;
a plurality of ink election elements, each ink election element being within a respective ink election chamber, said ink election elements being heated by electrical signals to elect droplets of said ink from a respective nozzle in fluid communication with a respective ink ejection chamber;
an ink conduit having a first wall and a second wall terminating proximate to said back surface of said substrate, so that ink flows through said ink conduit, across at least a portion of said back surface of said substrate, and into said ink ejection chambers; and
at least one bubble accumulation chamber for accumulating bubbles caused by heating of said ink by said substrate due to said electrical signals heating said ink election elements, said at least one bubble accumulation chamber comprising a cavity substantially surrounding said back surface of said substrate, said cavity configured such that said bubbles do not interfere with the flow of ink across said back surface of said substrate and into said ink election chambers.
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Abstract
An ink conduit for an inkjet printhead is disclosed which increases the velocity of ink flowing across the back surface of a substrate and into ink ejection chambers. The increased velocity of ink across the back surface of the substrate results in greater removal of heat from the substrate. This increased ink velocity is achieved by providing narrow ink conduit openings proximate to the back surface of the substrate. To avoid air bubbles becoming trapped in the relatively narrow ink conduit, one or more pockets are formed to allow the accumulation of bubbles, so that the bubbles do not affect the ink flow through the ink conduit and into the ink ejection chambers.
23 Citations
20 Claims
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1. A printing device comprising:
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a substrate having a front surface for facing a medium to be printed upon, said substrate having a back surface; a plurality of ink election chambers on said front surface which define cavities for receiving ink; a plurality of ink election elements, each ink election element being within a respective ink election chamber, said ink election elements being heated by electrical signals to elect droplets of said ink from a respective nozzle in fluid communication with a respective ink ejection chamber; an ink conduit having a first wall and a second wall terminating proximate to said back surface of said substrate, so that ink flows through said ink conduit, across at least a portion of said back surface of said substrate, and into said ink ejection chambers; and at least one bubble accumulation chamber for accumulating bubbles caused by heating of said ink by said substrate due to said electrical signals heating said ink election elements, said at least one bubble accumulation chamber comprising a cavity substantially surrounding said back surface of said substrate, said cavity configured such that said bubbles do not interfere with the flow of ink across said back surface of said substrate and into said ink election chambers. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method performed by a printer, said printer comprising a carriage and a printhead mounted in said carriage, said printhead comprising a substrate having a back surface and having a front surface for facing a medium to be printed upon, said ink ejection elements being located within respective ink ejection chambers on said front surface of said substrate, each of said ink ejection chambers defining a cavity for receiving ink, said printhead containing one or more bubble accumulation chambers, said one or more bubble accumulation chambers comprising a cavity substantially surrounding said back surface of said substrate, said cavity configured such that accumulated bubbles do not interfere with the flow of ink across said back surface of said substrate and into said ink ejection chambers, said method comprising the steps of:
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scanning said carriage across a print zone; providing energizing signals to heat said ink ejection elements within respective ink ejection chambers in said printhead mounted in said carriage; supplying ink through an ink conduit having an opening proximate to said back surface of said substrate, said ink flowing through said opening, across at least a portion of said back surface of said substrate, and into said ink ejection chambers; generating bubbles from gas being released from said ink as said ink is heated by energizing said ink ejection elements; and accumulating said bubbles in said one or more bubble accumulation chambers. - View Dependent Claims (19, 20)
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Specification