Abstract: A thermal bend actuator, having a plurality of elongate cantilever beams, is provided. The actuator comprises: a first active beam for connection to drive circuitry, the first beam being defined by a tortuous beam element, the tortuous beam element having a plurality of contiguous beam members; and a second passive beam mechanically cooperating with the first beam. When a current is passed through the first beam, the first beam expands relative to the second beam, resulting in bending of the actuator. The plurality of contiguous beam members comprises a plurality of longer beam members extending along a longitudinal axis of the first beam, and at least one shorter beam member extending across a transverse axis of the first beam and interconnecting longer beam members.

Abstract: A method of fabricating a printhead having a hydrophobic ink ejection face is provided. The method comprises the steps of: (a) providing a partially-fabricated printhead comprising a plurality of nozzle chambers and a relatively hydrophilic nozzle surface, the nozzle surface at least partially defining the ink ejection face; (b) depositing a layer of relatively hydrophobic polymeric material onto the nozzle surface, the polymeric material being resistant to removal by ashing; and (c) defining a plurality of nozzle openings in the nozzle surface, thereby providing a printhead having a relatively hydrophobic ink ejection face. Steps (b) and (c) may be performed in any order.

Abstract: An inkjet nozzle assembly is provided. The assembly comprises a nozzle chamber comprising a floor and a roof. The roof has a nozzle opening defined therein, and a moving portion moveable towards the floor. The assembly further comprises a thermal bend actuator, having a plurality of cantilever beams, for ejecting ink through the nozzle opening. A first active beam of the actuator defines at least 30% of a total area of the roof.

Abstract: An ink jet printhead includes a plurality of nozzles each having a nozzle aperture; a plurality of bubble forming chambers, each corresponding respectively to one of the plurality of nozzles; an inlet for communicating printing fluid between the nozzle aperture and a printing fluid supply, the inlet and the nozzle aperture being aligned along a common central axis; and a heater element disposed in each of the bubble forming chambers. Each heater element has two bubble nucleation regions suspended within the bubble forming chamber in a plane parallel to that of the nozzle aperture. The two bubble nucleation regions are laterally offset from the central axis, such that the lateral offset of one of the bubble nucleation regions is equal and opposite to the lateral offset of the other bubble nucleation region. The bubble nucleation regions are spaced from each other such that bubbles nucleated at each will grow until they unite to form the gas bubble that causes the ejection of a drop of ejectable liquid.

Abstract: An inkjet printhead that has an elongate chassis, first groups of apertures spaced along the elongate chassis, an ink distribution unit defining a plurality of ink distribution passages and second groups of apertures in fluid communication with respective ink distribution passages, the ink distribution unit being mounted to the elongate chassis so that the first group of apertures and the second group of apertures coincide and, a plurality of printhead modules for ejecting ink supplied through the ink distribution passages and the aligned first and second groups.

Abstract: A printhead nozzle arrangement is provided having a wafer defining a chamber for holding ejection fluid, an ejection port supported by a plurality of bridge members which extend from the ejection port to sides of the chamber, and a plurality of heater elements interleaved between the bridge members for causing ejection of fluid held in the chamber through the ejection port.

Abstract: A method of producing a thermoelastic actuator assembly having desired operating characteristics includes determining a desired negative pressure pulse characteristic for the actuator, determining a heat dissipation profile corresponding to the desired negative pressure pulse characteristic, and forming the thermoelastic actuator with a heat conduction means arranged to realize the profile.

Abstract: An inkjet printhead having a high density array of micro-electromechanical nozzles arrangements. Each arrangement comprises side walls located on a wafer substrate with a roof layer deposited on said walls to define an ink chamber, the roof layer defining a nozzle aperture; an inlet defined in the substrate to supply the ink chamber with printing fluid; and at least one heater element having a mass of less than 250 picograms suspended between the side walls in the chamber, the heater element operable to form a vapor bubble when electrical actuation energy of less than 120 nanojoules is applied thereto, said heater element having an annular shape with a point of collapse of the bubble near a center thereof.

Abstract: This invention provides for a nozzle arrangement for a printhead. The nozzle arrangement includes a substrate that defines an ink inlet passage. A nozzle plate is arranged on the substrate and defines an ink chamber in fluid communication with the ink inlet passage and a nozzle aperture in fluid communication with the ink chamber. A nozzle enclosure is arranged on the nozzle plate about the aperture and is configured to isolate the aperture from at least one adjacent aperture. The arrangement also includes a heater element suspended within the chamber and configured to produce ink cavitation when heated to eject a drop of ink via the nozzle aperture. The heater element is configured as a looped element so that no solid surface thereof is in the vicinity of a point of collapse of the produced cavitation.

Abstract: The invention provides for a micro-electromechanical nozzle arrangement for an inkjet printhead. The arrangement includes a substrate defining an inverted pyramidal ink chamber with a vertex thereof terminating at an ink supply channel defined by the substrate, said substrate having a layer of CMOS drive circuitry. The arrangement also includes a roof structure connected to the drive circuitry layer and covering the ink chamber, the roof structure defining a fluid ejection nozzle rim above said chamber. Also included is a plurality of actuators fast with and displaceable with respect to the roof structure, the actuators radially spaced about the nozzle rim between the guide rails. Each actuator has a serpentine heater element configured to expand thermally upon receiving current from the drive circuitry thereby moving said actuators into the chamber to increase a fluid pressure inside the chamber to eject a drop of ink via the ejection nozzle.

Abstract: An inkjet printhead that has a substrate with a first layer, a second layer; and a flexible element supported by the second layer. The flexible element has an orifice through which ink is ejected. An actuator deflects the flexible element to force the ink through the orifice. The substrate has an opening formed through the first layer and a hole through the second layer such that the hole and the opening are in fluid communication to supply ink to the flexible element.

Abstract: A printhead comprising a plurality of unit cells, at least one of the plurality of unit cells comprising a substrate including an ink inlet passage. A chamber is defined by chamber sidewalls and at least part of a nozzle plate defining an aperture for ejection of ink from the chamber, the chamber being in fluid communication with the inlet passage. A nozzle enclosure comprising enclosure sidewalls and a roof defining an opening for ejection of ink, the nozzle enclosure surrounding the aperture. Ink ejected from the aperture is directed to the opening of the nozzle enclosure, thereby isolating the aperture from an adjacent aperture of an adjacent unit cell.

Abstract: Provided is an inkjet printhead integrated circuit that has a wafer substrate that has an ink passage, and a nozzle plate supported on the substrate by side walls to define an ink chamber supplied with ink via the ink passage. The nozzle plate has an ink ejection port corresponding to the ink chamber. A heater element is bonded to the nozzle plate inside the chamber for vaporising ink to generate a vapour bubble that ejects ink through the ejection port. The heater element is bonded to the nozzle plate with a low thermal product layer. The thermal product thermal product is less than 1495 Jm?2K?1s?1/2, the thermal product being (?Ck)1/2, where ? is the density of the layer, C is specific heat of the layer and k is thermal conductivity of the layer.

Abstract: A printhead for an inkjet printer includes a wafer defining a plurality of nozzle chambers and a plurality of ink supply channel in fluid communication with the plurality of nozzle chambers for supplying the plurality of nozzle chambers with ink; an ink ejection port associated with each nozzle chamber; and a plurality of actuators associated with each nozzle chamber, the plurality of actuators each including a petal formation. A plurality of petal formations are arranged around an ink ejection port of each nozzle chamber to annularly surround the ink ejection port. Each actuator is operable to displace a respective petal formation into the nozzle chamber.

Abstract: A method of fabricating a micro-mirror assembly. The method comprises the steps of: (a) forming a pair of electrodes spaced apart on a surface of a substrate; (b) depositing a layer of sacrificial material over the electrodes and the substrate; (c) defining a stem opening in the sacrificial material so as to form a scaffold; (d) depositing a layer of resiliently flexible material over the scaffold; (e) depositing a metal layer over the flexible layer; (f) etching through the metal layer and the flexible layer to define an individual micro-mirror; and (g) removing the sacrificial material to provide the micro-mirror assembly. The method produces a micro-mirror assembly with minimal number of MEMS fabrication steps.

Abstract: A MEMS integrated circuit comprises: a silicon substrate having a passivated CMOS layer, a MEMS layer disposed on the passivated CMOS layer, and a polymer layer disposed on the MEMS layer. The CMOS layer comprises drive circuitry for actuating actuator devices in the MEMS layer and the polymer layer comprises a polymerized siloxane.

Abstract: An inkjet nozzle assembly has a chamber with a nozzle opening for ejecting a liquid, a heater element disposed in the chamber, and a dielectric layer sandwiched between the heater element and a wall of the chamber. The dielectric layer has a thermal product of less than 1495 Jm?2K?1s?1/2. The thermal product is defined as (?Ck)1/2, where ? is the density of the layer, C is specific heat of the layer and k is thermal conductivity of the layer.

Abstract: A digital micro-mirror device comprising an array of micro-mirror assemblies positioned on a substrate. Each micro-mirror assembly comprises: a mirror spaced apart from the substrate; a stem supporting the mirror; and first and second electrodes positioned on either side of the stem. The stem is comprised of a resiliently flexible material, such that the mirror can tilt either towards the first electrode or towards the second electrode by an electrostatic force. The digital micro-mirror device may be used in data projectors and the like.

Abstract: A thermal bend actuator, having a plurality of elements, is provided. The actuator includes a first active element for connection to drive circuitry a second passive element mechanically cooperating with the first element. When a current is passed through the first element, the first element expands relative to the second element, resulting in bending of the actuator. The second element includes a material having negative thermal expansion.

Abstract: A nozzle assembly for an inkjet printhead. The nozzle assembly includes a nozzle chamber with a roof having a nozzle opening defined therein. The roof includes a moving portion moveable relative to a stationary portion, such that movement of the moving portion relative to the stationary portion causes ejection of ink through the nozzle opening. The nozzle assembly also includes an actuator for moving the moving portion and a seal member. The seal member is configured as a bridge spanning between the moving portion and the stationary portion.