| Patent application number | Description | Published |
|---|
| 20080239009 | INKJET PRINTHEAD HAVING MEMS SENSORS FOR DIRECTIONALLY HEATED INK EJECTION - An inkjet printhead is provided having nozzles, bubble forming chambers containing ejectable ink, generally planar heater elements each bonded on one side to an associated chamber so that the other side faces into the chamber, a MEMS fluid sensor having a MEMS sensing element for detecting the presence or otherwise of the ejectable ink in the chamber, and control circuitry for measuring the current passing through the sensing element during its heating. The heater elements receive heating pulses to form gas bubbles in the ejectable ink on the side facing into the chamber which cause ink ejection from the nozzle. Each chamber has a dielectric layer proximate the side of the heater element which has a thermal product less than 1495 Jm | 10-02-2008 |
| 20080316256 | PRINTHEAD ASSEMBLY WITH SANDWICHED POWER SUPPLY ARRANGEMENT - A printhead assembly is provided for a printer system. The printhead assembly includes an elongate substrate defining a channel and spaced apart sets of ink supply holes. An ink distribution arrangement is located within the channel and is configured to distribute ink to the sets of ink supply holes. A first plate is in engagement with the substrate to hold the ink distribution arrangement within the channel. A power supply arrangement is also located within the channel. A second plate is in engagement with the substrate so that the power supply arrangement is sandwiched between the plates and held within the channel. | 12-25-2008 |
| 20090002421 | INKJET PRINTHEAD COMPRISING BONDED HEATER ELEMENT AND DIELECTRIC LAYER WITH LOW THERMAL PRODUCT - A thermal inkjet printhead with generally planar heater elements disposed in respective bubble forming chambers such that they are bonded on one side to the chamber so that the other side faces into the chamber. Each heater element receives an energizing pulse to heat ejectable liquid above its boiling point to form a gas bubble on the side facing into the chamber, whereby the gas bubble causes the ejection of a drop of the ejectable liquid from the nozzle. The chamber has a dielectric layer proximate the side of the heater element bonded to the chamber. The dielectric layer has a thermal product less than 1495 Jm | 01-01-2009 |
| 20090002440 | Inkjet Printer With Droplet Stem Anchor - An inkjet printer that has an array of ink chambers, each with a nozzle, a droplet stem anchor and a thermal actuator. The thermal actuator generates a vapour bubble in the ink chamber to eject ink through the nozzle. The thermal actuator has a plurality of heater elements connected in parallel with a cross bracing structure extending between the heater elements. The cross bracing structure also providing the droplet stem anchor. During use, the vapour bubble generated by the thermal actuator grows until it vents to atmosphere through the nozzle and the ink ejected from the nozzle is attached to the droplet stem anchor by an ink stem until the stem breaks and the ejected ink forms a separate drop. | 01-01-2009 |
| 20090002459 | Printhead With Low Viscous Drag Droplet Ejection - A inkjet printhead with heater elements adjacent an array of respective nozzles for heating a water-based printing fluid to form a gas bubble for ejecting a drop of the printing fluid from the nozzle. The heater is separated from the nozzle by less than 5 μm at their closest points and the nozzle length is less than 5 μm. The volume of liquid between the heater and the nozzle determines the inertia of the liquid and its acceleration in response to bubble formation. Moving the heater closer to the nozzle reduces the inertia of the liquid and increases its acceleration, so a lower bubble impulse is needed to eject a drop. This allows the printhead to use smaller heater elements with lower power requirements. Viscous drag in the nozzle reduces the momentum of fluid flowing through the nozzle. The viscous drag increases as the nozzle length (in the direction of fluid flow) increases. By reducing the nozzle length, a lower bubble impulse is needed to eject a drop. This also allows the printhead to use smaller heater elements with lower power requirements. | 01-01-2009 |
| 20090015637 | INKJET NOZZLE ARRANGEMENT HAVING A NOZZLE RIM TO FACILITATE INK DROP MISDIRECTION - Provided is an inkjet nozzle arrangement for an inkjet printhead. The arrangement includes a wafer substrate defining sidewalls and a roof portion to form an ink chamber, the roof portion further defining a nozzle aperture, as well as a heater element suspended inside the ink chamber for thermal expansion and subsequent ejection of ink from the chamber via the nozzle aperture. The arrangement also includes a nozzle rim defined about the aperture on the roof portion, said rim having an inner and an outer lip to facilitate ink drop misdirection during ink ejection to minimise cavitation corrosion of the heater element. | 01-15-2009 |
| 20090185009 | INKJET PRINTHEAD INTEGRATED CIRCUIT WITH RECTIFYING VALVES - Provided is a unit cell arrangement for an inkjet printhead. The unit cell arrangement includes a substrate that defines an ink inlet and sidewalls supporting a roof portion on the wafer substrate to form an ink chamber. The roof portion defines at least one nozzle rim. The unit cell also includes a heater element suspended in the chamber between the sidewalls for thermal cavitation of ink in the chamber to facilitate ink ejection via the nozzle rim. Further included is a rectifying valve arranged in the ink inlet to provide decreased hydraulic resistance to ink flowing into the chamber than ink flowing out of the chamber in order to reduce fluidic cross talk between chambers of similar unit cells on the substrate and to improve ink refill times of the chambers. | 07-23-2009 |
| 20100002059 | Inkjet Thermal Actuator With Parallel Current Paths - An inkjet printhead comprising: an array of ink chambers, each having a nozzle and a thermal actuator for generating vapour bubbles to eject ink through the nozzle; wherein, the thermal actuator has a pair of contacts and at least two parallel current paths between the contacts, each of the current paths having a plurality of heater elements for nucleating a vapour bubble. | 01-07-2010 |
| 20100073432 | Ink Jet Printhead Incorporating Heater Element Proportionally Sized To Drop Size - An inkjet printhead comprises a plurality of nozzles; a supply of printing fluid in fluid communication with the plurality of nozzles; and a plurality of heater elements corresponding respectively to each of the nozzles, the heater elements for heating the printing fluid to form a gas bubble for ejecting a drop of printing fluid of a predetermined volume from the nozzle. Each of the heater elements has an area proportional to the predetermined volume. The area being such that an amount of energy generated by each heater element to form the gas bubble is substantially equal to or less than an amount of energy absorbable by a drop of printing fluid having the predetermined volume. | 03-25-2010 |
| 20100103216 | MEMS FLUID SENSOR - A fluid sensor for detecting fluid in a chamber, has a MEMS sensing element of conductive material with a resistance that is a function of temperature, and electrical contacts for connection to an electrical power source for heating the sensing element with an electrical signal, so that control circuitry can measure the current passing through the sensing element during heating of the sensing element; and determine the temperature of the sensing element from the known applied voltage, the measured current and the known relationship between the current, resistance and temperature. As the temperature of the element will be greater if it is in the presence of gas rather than liquid, the sensor determines if there is liquid or gas in the chamber. This is particularly useful to detect if the chambers of an inkjet printhead are primed with ink. | 04-29-2010 |
| 20100134567 | INKJET PRINTHEAD WITH HEATER ELEMENTS HAVING PARALLEL CURRENT PATHS - An inkjet printhead having an array of ink chambers is disclosed. Each ink chamber has a nozzle and a heater element for generating vapour bubbles to eject ink through the nozzle. The heater element has multiple current paths connected in parallel. Each current path has at least one portion with a reduced cross-section relative to the remainder of the current path. A cross bracing structure is also provided for connecting intermediate portions of the current paths. | 06-03-2010 |
| 20100149279 | INKJET NOZZLE ASSEMBLY HAVING HEATER ELEMENT BONDED TO CHAMBER WALL VIA DIELECTRIC LAYER - 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 | 06-17-2010 |
| 20100231654 | Ink Chamber with Droplet Step Anchor - Provided is an inkjet printhead having an array of ink chambers formed on a planar support surface of a wafer substrate. Each ink chamber in the array has a nozzle, a thermal actuator for ejecting ink through the nozzle and a droplet stem anchor. The thermal actuator has two sections with higher resistance than the remainder of the thermal actuator. The droplet stem anchor is positioned between the two sections with higher resistance of the thermal actuator. | 09-16-2010 |
