Abstract: A printhead integrated circuit is provided. The integrated circuit comprises a substrate, a plurality of inkjet nozzles formed on the substrate and drive circuitry connected to the inkjet nozzles. Each inkjet nozzle comprises a nozzle chamber for storing ink to be ejected, at least one moveable actuator paddle forming at least a portion of a first wall of the nozzle chamber and an ink ejection opening defined in the first wall. In use, actuation of the actuator paddle causes ejection of ink from the nozzle.

Abstract: An inkjet printhead integrated circuit is provided comprising a substrate defining ink supply channels, a drive circuitry layer positioned on the substrate, and nozzle arrangements positioned on the substrate electrically connected to the drive circuitry. Each nozzle arrangement comprises a nozzle chamber defined by the substrate, a roof structure positioned over the chamber defining an ink ejection port, and a thermal actuator positioned in the roof. A portion of the actuator is made of a material which expands when heated and the actuator is arranged to receive an electrical current from the drive circuitry to heat the portion. Upon receipt of the current, the actuator is configured to be displaceable towards the substrate so as to reduce a volume of the chamber. Upon cessation of the current, the actuator is configured to be displaceable back to its original position so that ink is ejected from the ejection port.

Abstract: An ink jet printhead comprises a substrate having a plurality of nozzle arrangements formed therein. For each nozzle arrangement, an ink chamber is formed in the substrate. A rim disposed over the chamber defines an ink ejection port and a wall extending over said chamber and including a flexible portion defines an actuator. When actuated the wall moves independently of the rim and into said ink chamber forcing ink therein, out through the said ink ejection port. The flexible portion of said wall is made from material having a thermal expansion suitable to cause the wall to move into said ink chamber upon uneven heating of the flexible portion of the wall.

Abstract: The invention describes an inkjet printhead. The printhead includes an array of ink chambers, each with an outer wall defining an ink ejection port and having at least one actuator. The outer wall faces the print media substrate during use wherein the actuator move the ejection port away from the media substrate in order eject ink through the port. This arrangement does not have any actuators within the chamber to slow ink refill and the return of the outer wall to its quiescent state assists ink refill.

Abstract: A thermal inkjet printhead with generally planar heater elements disposed in respective bubble forming chambers, whereby the area of each heater is less than 300 ?m2. The heater area influences: 1. the energy required to heat the heater volume up to the fluid superheat limit; 2. the energy required to heat the protective coatings covering the heater to the superheat limit; 3. the heat that diffuses into the underlayer prior to bubble nucleation; and, 4. the heat that diffuses into the ink prior to bubble nucleation. Reducing the surface area of the heater reduces all of these terms and has a significant impact on the energy required to form a bubble and eject ink.

Abstract: A printer has a printhead comprising an array of nozzles. A nozzle arrangement has an ink chamber formed in a wafer substrate and one wall of said chamber having at least one flexible portion. The ink ejection port is formed substantially centrally on the wall with a rim surrounding it. The wall is adapted to move independently of said rim such that upon heating of the flexible portion of the wall, the wall bends into said ink chamber forcing ink therein out through the said ejection port.

Abstract: An ink jet printhead nozzle arrangement having an ink chamber formed in a wafer substrate and one wall of said chamber having at least one flexible portion. The ink ejection port is formed substantially centrally on the wall with a rim surrounding it. The wall is adapted to move independently of said rim such that upon heating of the flexible portion of the wall, the wall bends into said ink chamber forcing ink therein out through the said ejection port.

Abstract: A printer has an inkjet printhead formed on a wafer substrate. Formed in the wafer are a plurality of nozzle chambers for storing ink to be ejected. Each of the nozzle chambers has an outer wall defining an ink ejection port. In use, actuators cause the ink ejection port to move inward causing ink to be ejected through the nozzle. The actuators include a surface which bends inwards away from the centre of the nozzle chamber upon actuation and a thermal actuator device having a conductive resistive heating element encased within a material having a high coefficient of thermal expansion.

Abstract: A thermal inkjet actuator for use in an inkjet printer assembly includes heat conduction means arranged to realize a predetermined negative pressure profile to facilitate droplet formation. In a preferred embodiment the heat conduction means comprises a thin layer (54) of very high thermally conductive material such as Aluminium located in the middle of a non-heat conductive passive bend layer (56). The overall cool-down speed of the actuator, and hence the speed with which the passive bend layer returns to its quiescent position can be controlled by controlling the proximity of the heat conductive layer to the actuator's heater during fabrication.

Abstract: A printhead chip includes a substrate that incorporates a drive circuitry layer and defines a plurality of nozzle chambers and respective ink supply channels in fluid communication with the nozzle chambers. A plurality of nozzles is positioned on the substrate to be in fluid communication with respective nozzle chambers. A plurality of actuators is connected to the drive circuitry layer and is reciprocally displaceable with respect to the substrate on receipt of an electrical signal from the drive circuitry layer. At least one actuator is associated with each respective nozzle chamber. The actuators are positioned so that reciprocal displacement of each actuator results in reduction and subsequent enlargement of each respective nozzle chamber to eject ink drops from the respective nozzles.

Abstract: A micro-electromechanical actuator assembly includes a substrate that defines a fluid reservoir. An actuator is positioned in the reservoir and has a region of bend material and a heater. The heater is positioned so that heating of the actuator results in differential thermal expansion of the actuator to generate movement and subsequent ejection of ink. The actuator has at least one region of heat conductive material that is positioned to conduct heat from the actuator to facilitate cooling of the actuator.

Abstract: A micro-electromechanical fluid ejection device includes a substrate that defines a plurality of fluid supply channels and a plurality of chambers in fluid communication with respective fluid supply channels. A drive circuitry layer is positioned on the substrate. A plurality of roof structures is connected to the drive circuitry layer to cover respective fluid chambers. Each roof structure defines a fluid ejection port. At least one actuator is positioned in each roof structure. Each actuator is electrically connected to the drive circuitry layer to be displaceable into and out of its respective chamber to eject a drop of fluid from the fluid ejection port. At least some of the roof structures comprise a fixed portion that remains stationary during fluid ejection.

Abstract: An inkjet printhead chip includes a wafer substrate. A drive circuitry layer is positioned on the wafer substrate. A plurality of nozzle chambers is defined in the wafer substrate. A plurality of ink inlet openings is defined in the wafer substrate, in fluid communication with respective nozzle chambers. A plurality of nozzle chamber walls is opposite respective ink inlet openings and each defines an ink ejection port. A plurality of ink ejection actuators is connected to the drive circuitry layer. At least one actuator is positioned in each wall and is displaceable into the respective nozzle chamber to reduce a volume of the nozzle chamber and thus to eject ink from the nozzle chamber.

Abstract: A thermoelastic device comprising an expansive element is disclosed. The expansive element is formed from a material, which is preselected by calculating a dimensionless constant for the material. The dimensionless constant is indicative of the potential effectiveness of the material in a particular application, such as a micro-electromechanical system.

Abstract: A nozzle arrangement for an ink jet printhead includes a wafer substrate having a nozzle chamber defined therein. The nozzle arrangement has a nozzle chamber wall that defines an ink ejection port and a rim about the ink ejection port. An array of actuators connected to the wafer substrate and configured so that an edge of each actuator is displaceable, into the chamber, upon actuation of the actuator. This displacement reduces the volume within the nozzle, resulting in the ejection of ink from the ejection port.

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. Each heater element is configured such that an actuation energy of less than 500 nanojoules (nJ) is required to be applied to that element to heat it sufficiently to form such a bubble in the bubble forming liquid (which liquid can also be the ink). This configuration thus provides for a high efficiency printhead.