Pump action refill ink jet printing mechanism
First Claim
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1. An ink jet printhead comprising:
- a nozzle chamber having an ink ejection port in one wall of said chamber;
an ink supply source interconnected to said nozzle chamber via another wall of said chamber;
a first moveable actuator in said another wall of said chamber for ejecting ink from said ink ejection port; and
a second moveable actuator in said another wall of said chamber for pumping ink into said chamber from said ink supply source after said first actuator has caused the ejection of ink from said chamber.
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Abstract
This patent describes an ink jet printer based around ink jet nozzles which utilize a pump action so as to rapidly refill a nozzle chamber for ejection of subsequent ink drops. The nozzle chamber includes a first actuator for ejecting ink and a second actuator for pumping ink into the nozzle chamber. The actuators can comprise thermal bend actuators having a conductive heater element encased within a material having a high co-efficient of thermal expansion. The heater element is of a serpentine form and is concertinaed upon heating.
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Citations
16 Claims
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1. An ink jet printhead comprising:
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a nozzle chamber having an ink ejection port in one wall of said chamber;
an ink supply source interconnected to said nozzle chamber via another wall of said chamber;
a first moveable actuator in said another wall of said chamber for ejecting ink from said ink ejection port; and
a second moveable actuator in said another wall of said chamber for pumping ink into said chamber from said ink supply source after said first actuator has caused the ejection of ink from said chamber. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
(a) said first actuator ejects ink from said ink ejection port; and
(b) said second actuator pumps ink towards said ink ejection port so as to rapidly refill the nozzle chamber around the area of said ink ejection port.
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10. An ink jet printhead as claimed in claim 1 wherein surfaces of said actuators are treated to make them hydrophilic.
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11. An ink jet printhead as claimed in claim 1 wherein said actuators are formed by utilization of a sacrificial material layer which is etched away to release said actuators.
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12. An ink jet printhead as claimed in claim 1 wherein portions of said nozzle include a silicon nitride covering so as to insulate and passivate them from adjacent portions.
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13. An ink jet printhead as claimed in claim 1 wherein said nozzle chamber is formed from crystallographic etching of a silicon substrate.
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14. An ink jet printhead as claimed in claim 1 wherein said nozzle is constructed via fabrication from a silicon wafer utilizing semiconductor fabrication techniques.
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15. An ink jet printhead as claimed in any one of claims 1 to 5 wherein:
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(a) said first actuator is activated to eject ink from said ink ejection port;
(b) said first actuator is deactivated so as to cause a portion of said ejected ink to break off from a main body of ink within said nozzle chamber;
(c) said second actuator is activated to pump ink towards said ink ejection port so as to rapidly refill the nozzle chamber around the are of said ink ejection port; and
(d) said first actuator is activated to eject ink from the ink ejection port while simultaneously deactivating said second actuator so as to return to its quiescent position;
otherwise(e) said second actuator is deactivated to return to its quiescent position.
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16. An ink jet printhead comprising:
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a nozzle chamber having an ink ejection port in one wall of said chamber;
an ink supply source interconnected to said nozzle chamber via another wall of said chamber;
a first moveable actuator in said another wall of said chamber for ejecting ink from said ink ejection port said first moveable actuator being arranged substantially opposite said ink ejection port;
a second moveable actuator in said another wall of said chamber for pumping ink into said chamber from said ink supply source after said first actuator has caused the ejection of ink from said chamber, wherein said first and second actuators form segments of a nozzle chamber wall opposite said ink ejection port and between said nozzle chamber and ink supply source; and
said actuators comprise a conductive heater element encased within a material having a high co-efficient of thermal expansion whereby said actuators operate by means of electrical heating by said heater element and wherein said heater element is of a serpentine form and is concertinaed upon heating so as to allow substantially unhindered expansion of said material during heating.
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Specification