An example method of purging filler fluid from a printhead of a printing device includes applying a plurality of energy levels to a resistor coupled to the printhead. In addition, the method includes determining a temperature profile of a fluid within the printhead while applying the plurality of energy levels. Further, the method includes characterizing the fluid based on the temperature profile.

A fluid ejection device includes a fluid slot, a plurality of fluid ejection chambers communicated with the fluid slot, a plurality of drop ejecting elements one of each within one of the fluid ejection chambers, a plurality of fluid circulation channels each communicated with the fluid slot and one or more of the fluid ejection chambers, and a plurality of fluid circulating elements each communicated with one or more of the fluid circulation channels. The fluid circulating elements are to provide intermittent circulation of fluid from the fluid slot through the one or more of the fluid circulation channels and the one or more of the fluid ejection chambers.

An integrated semiconductor heating assembly includes a semiconductor substrate, a chamber formed therein, and an exit port in fluid communication with the chamber, allowing fluid to exit the chamber in response to heating the chamber. The integrated heating assembly includes a first heating element adjacent the chamber, which can generate heat above a selected threshold and bias fluid in the chamber toward the exit port. A second heating element is positioned adjacent the exit port to generate heat above a selected threshold, facilitating movement of the fluid through the exit port away from the chamber. Addition of the second heating element reduces the amount of heat emitted per heating element and minimizes thickness of a heat absorption material toward an open end of the exit port. Since such material is expensive, this reduces the manufacturing cost and retail price of the assembly while improving efficiency and longevity thereof.

A fluid ejection device includes a fluid slot, a plurality of fluid ejection chambers communicated with the fluid slot, a plurality of drop ejecting elements one of each within one of the fluid ejection chambers, a plurality of fluid circulation channels each communicated with the fluid slot and one or more of the fluid ejection chambers, and a plurality of fluid circulating elements each communicated with one or more of the fluid circulation channels. The fluid circulating elements are to provide intermittent circulation of fluid from the fluid slot through the one or more of the fluid circulation channels and the one or more of the fluid ejection chambers.

A printing apparatus includes an ink treatment chamber having an inlet for receiving ink into the chamber. The ink is received in a non-gaseous statement. Heating elements heat the ink in the ink treatment chamber. After being heated, a nozzle ejects the heated ink. The heating of the ink may cause the ink to be changed to a gaseous ink and the gaseous ink may be ejected by the nozzle.

A fluid ejection device includes a fluid slot, a plurality of fluid ejection chambers communicated with the fluid slot, a plurality of drop ejecting elements one of each within one of the fluid ejection chambers, a plurality of fluid circulation channels each communicated with the fluid slot and one or more of the fluid ejection chambers, and a plurality of fluid circulating elements each communicated with one or more of the fluid circulation channels. The fluid circulating elements are to provide intermittent circulation of fluid from the fluid slot through the one or more of the fluid circulation channels and the one or more of the fluid ejection chambers.

A fluid ejection device includes a fluid slot, a plurality of fluid ejection chambers communicated with the fluid slot, a plurality of drop ejecting elements one of each within one of the fluid ejection chambers, a plurality of fluid circulation channels each communicated with the fluid slot and one or more of the fluid ejection chambers, and a plurality of fluid circulating elements each communicated with one or more of the fluid circulation channels. The fluid circulating elements are to provide intermittent circulation of fluid from the fluid slot through the one or more of the fluid circulation channels and the one or more of the fluid ejection chambers.

A fluid ejection cartridge may include a substrate including substrate ribs that define fluid feed slots extending from a first side to a second side of the substrate, fluid chambers having nozzle openings on a first side of the substrate, an ejection element within each of the fluid chambers and a substrate carrier on a second side of the substrate. The substrate carrier may include carrier ribs that define fluid passageways having oblique centerlines and internal widths that gradually increase from a first width proximate the substrate to a second width, greater than the first width, distant the substrate. Concavely tapered adhesive bonds directly contact faces of the substrate ribs and the carrier ribs to adhere the substrate ribs to the carrier ribs.

A printing apparatus includes an ink treatment chamber having an inlet for receiving ink into the chamber. The ink is received in a non-gaseous statement. Heating elements heat the ink in the ink treatment chamber. After being heated, a nozzle ejects the heated ink. The heating of the ink may cause the ink to be changed to a gaseous ink and the gaseous ink may be ejected by the nozzle.

A fluid ejection cartridge may include a substrate including substrate ribs that define fluid feed slots extending from a first side to a second side of the substrate, fluid chambers having nozzle openings on a first side of the substrate, an ejection element within each of the fluid chambers and a substrate carrier on a second side of the substrate. The substrate carrier may include carrier ribs that define fluid passageways having oblique centerlines and internal widths that gradually increase from a first wid Attached Attached Attached Attached for your review Attached for your review th proximate the substrate to a second width, greater than the first width, distant the substrate. Concavely tapered adhesive bonds directly contact faces of the substrate ribs and the carrier ribs to adhere the substrate ribs to the carrier ribs.