Thermal ink jet printhead with cavitation gap
AssigneeSilverbrook Research Pty Ltd
InventorKia Silverbrook
Life of this patent
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Abstract
There is disclosed an ink jet printhead which comprises a plurality of nozzles and one or more heater elements corresponding to each nozzle. Each heater element is configured to heat a bubble forming liquid in the printhead to a temperature above its boiling point to form a gas bubble therein. The generation of the bubble causes the ejection of a drop of an ejectable liquid (such as ink) through the respective corresponding nozzle, to effect printing. The bubble forming liquid (which may also be the ink) is collapsible, having a point of collapse towards which it collapses, and each heater element is configured such that the point of collapse of a bubble formed by it is spaced from that heater element.
Claims50
An ink jet printhead comprising:
- a plurality of nozzles;
- and
- at least one respective heater element corresponding to each nozzle, wherein
- each heater element is arranged for being in thermal contact with a bubble forming liquid,
- each heater element is configured to heat at least part of the bubble forming liquid to a temperature above its boiling point to form therein a collapsible gas bubble having a point of collapse, thereby to cause the ejection of a drop of an ejectable liquid through the nozzle corresponding to that heater element, and
- each heater element is configured such that the point of collapse of a bubble formed thereby is spaced from that heater element.
A printer system incorporating a printhead, the printhead comprising:
- a plurality of nozzles;
- and
- at least one respective heater element corresponding to each nozzle, wherein
- each heater element is arranged for being in thermal contact with a bubble forming liquid,
- each heater element is configured to heat at least part of the bubble forming liquid to a temperature above its boiling point to form therein a collapsible gas bubble having a point of collapse, thereby to cause the ejection of a drop of an ejectable liquid through the nozzle corresponding to that heater element, and
- each heater element is configured such that the point of collapse of a bubble formed thereby is spaced from that heater element.
A method of ejecting a drop of an ejectable liquid from a printhead, the printhead comprising a plurality of nozzles and at least one respective heater element corresponding to each nozzle, the method comprising the steps of:
- heating at least one heater element correspoding to a nozzle so as to heat at least part of a bubble forming liquid which is in thermal contact with the at least one heated heater element to a temperature above the boiling point of the bubble forming liquid;
- generating a collapsible gas bubble, having a point of collapse, in the bubble forming liquid by said step of heating, such that the point of collapse is spaced from the at least one heated heater element;
- and
- causing the drop of ejectable liquid to be ejected through the nozzle corresponding to the at least one heated heater element by said step of generating a gas bubble.
Dependencies are inferred from the claim text.