Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
2001-04-16
2003-04-15
Gordon, Raquel Yvette (Department: 2853)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
Reexamination Certificate
active
06547371
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the construction of micro-electro mechanical devices such as ink jet printers.
BACKGROUND OF THE INVENTION
In international patent application PCT/AU98/00550, the present applicant has proposed an ink jet printing device which utilises micro-electro mechanical (mems) processing techniques in the construction of a print head driven by thermal bend actuator devices for the ejection of fluid such as ink from an array of nozzle chambers.
Devices of this type have a number of limitations and problems.
It is an object of the present invention to provide various aspects of an inkjet printing device which overcomes or at least ameliorates one of or more of the disadvantages of the prior art or which at least offers a useful alternative thereto.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the present invention, there is provided an inkjet printhead having a series of nozzles for the ejection of ink wherein each said nozzle has a rim formed by the conformal deposition of a rim material layer over a sacrificial layer and a subsequent planar etching of at least said rim material layer so as to form said nozzle rim.
The planar etching can comprise chemical-mechanical planarization of the rim material layer and any associated sacrificial layers.
In accordance with a second aspect of the present invention, there is provided an inkjet printhead comprising:
a plurality of nozzle chambers each having an ink ejection aperture in one wall thereof and an actuator interconnection aperture in a second wall thereof;
a moveable ink ejection paddle located within the nozzle chamber and moveable under the control of an external thermal actuator through said actuator interconnection aperture for the ejection of ink out of said ink ejection aperture;
said external actuator being covered by a protective covering shell around the operational portions of said actuator, spaced apart from said actuator.
The protective covering shell can be formed simultaneously with the formation of other portions of the inkjet printing arrangement in particular with the nozzle chamber walls.
The protective covering shell can be formed by deposition and etching of a sacrificial material layer followed by deposition and etching of an inert material layer forming the covering shell.
The external actuator can comprise a thermal bend actuator.
In accordance with a third aspect of the present invention, there is provided a method of forming an inkjet printhead on a substrate said method including:
providing a first substrate on which is formed electrical drive circuitry made up of one or more interleaved layers of conductive, semi-conductive and non-conductive materials for the control of said inkjet printhead;
forming on said substrate at least one nozzle chamber having an ink ejection aperture in one wall thereof;
providing a moveable ink ejection paddle within said nozzle chamber, moveable under the control of an actuator for the ejection of ink out of said ink ejection aperture;
and utilizing portions of at least one of said interleaved layers as a sacrificial material layer in the formation of one or more of the group comprising said actuator and said ink ejection paddle.
The sacrificial material layer can comprise portions of a conductive layer of the electrical drive circuitry. The electrical drive circuitry can comprise a Complementary Metal Oxide (CMOS) process and the sacrificial material layer can comprise a CMOS metal layer.
The sacrificial material layer can be utilized in formulating the actuator. The actuator can comprise a thermal actuator. The actuator can be located external to the nozzle chamber and can be interconnected to the ink ejection paddle through an actuation interconnection aperture formed in a second wall of the nozzle chamber.
In accordance with a fourth aspect of the present invention, there is provided an inkjet printhead constructed by MEMS processing techniques with a plurality of ink ejection nozzles each having a nozzle chamber, an external thermal bend actuator having a proximal end anchored to a substrate and a distal end connected to an ink ejection paddle within said chamber;
wherein said external thermal bend actuator further comprises a series of layers and includes a planar conductive heating circuit layer which includes a first portion adjacent said proximal end forming a planar conductive heating circuit for heating said thermal bend actuator, and a second portion extending into said ink ejection paddle, said second portion being electrically isolated from said first portion by means of a discontinuity in said planar conductive heating circuit layer, said discontinuity being located external to said nozzle chamber.
The planar conductive heating circuit layer can comprise substantially titanium nitride. The conductive circuit preferably can include at least one tapered portion adjacent the proximal end so as to increase resistive heating adjacent the proximal end.
In accordance with a fifth aspect of the present invention, there is provided an inkjet printhead having a series of ink ejection nozzles for the ejection of ink, each of said nozzles interconnecting a nozzle chamber with an external atmosphere, each said nozzle having a first meniscus rim around which an ink meniscus normally forms, and an extended ink flow prevention rim spaced outwardly from said first meniscus rim and substantially encircling said first meniscus rim, arranged to prevent the flow of ink across the surface of said inkjet printhead.
The ink flow prevention rim can be substantially co-planar with the first meniscus rim and can be formed from the same material as the first meniscus rim.
The ink flow prevention rim and the first meniscus rim are preferably formed utilizing chemical mechanical planarization.
The ink flow prevention rim and the first meniscus rim are preferably formed from Titanium Nitride.
In accordance with a sixth aspect of the present invention, there is provided a moveable micromechanical device including a bend actuator adapted to curve in a first bending direction and having a substantially planar bottom surface, said bend actuator being formed on a plane substrate on top of a number of deposited lower layers, wherein the bend actuator is formed by a plurality of steps including:
forming a series of structures in said deposited lower layers, said series of structures having a surface profile including a series of elongate ribs running in a direction substantially transverse to said first bending direction.
The bend actuator can comprise a thermal bend actuator. The deposited layers can include a conductive circuitry layer and can be interconnected to the bend actuator for activation of the bend actuator. The bend actuator can be attached to a paddle member and actuated for the ejection of ink from an ink ejection nozzle of an inkjet printhead. The deposited layer, located under the bend actuator can include a power transistor for the control of operation of the bend actuator.
In accordance with a seventh aspect of the present invention, there is provided a method of construction of an inkjet printhead having a large array of inkjet nozzle arrangements said method comprising:
defining a single inkjet nozzle arrangement for the ejection of ink from a single nozzle; and
utilizing a series of translations and rotations of said single inkjet nozzle arrangement to form all the inkjet nozzles of said inkjet print head;
said utilizing step including:
initially forming a plurality of nozzles in a pod;
forming a group of pods, each group corresponding to a different colored ink dispensed from said printhead;
forming a plurality of said groups of pods into a firing group;
combining firing groups forming a segment of said printhead;
forming each segment together to form said printhead.
The inkjet nozzle arrangements can include a series of layers deposited and etch utilizing a mask. The layers can include conductive layers which are preferably etched utilizing the mask so as to form a series of conductive interconnections. The co
Gordon Raquel Yvette
Silverbrook Research Pty Ltd
LandOfFree
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