A liquid discharging head includes a discharge port that discharges a liquid, a pressure chamber that communicates with the discharge port, and an energy generating element that is disposed in the pressure chamber. In the liquid discharging head, the discharge port is provided with a plurality of projections that project towards a central portion of the discharge port from an inner peripheral edge of the discharge port, and an interval between the projections at a location where the projections are closest to each other is 5 m or less.

Fluid ejection devices with multiple activation modes are disclosed. An example printhead assembly includes a fluid ejection nozzle, a first resistor fluidically coupled to the fluid ejection nozzle, and a second resistor fluidically coupled to the fluid ejection nozzle. The example printhead also includes an addressing circuit to receive a nozzle address and an activation mode to activate the fluid ejection nozzle. The activation mode determines which of the first resistor and the second resistor are to be energized.

To make it possible to eject a difference in a change of temperature of liquid accompanying ejection of ink between normal ejection and ejection failure. The liquid ejection apparatus includes: a driving unit configured to drive a heating element; and a detection unit configured to detect an ejection state of the liquid ejection head based on an output from a temperature detection element provided in the liquid ejection head, wherein the liquid ejection head includes, in correspondence to the ejection port: a foaming chamber communicating with the ejection port; a first heating element for ejecting liquid by providing thermal energy to liquid in the foaming chamber; the temperature detection element for detecting temperature in the foaming chamber; and a second heating element generating thermal energy and arranged closer to the temperature detection element than the first heating element.

A fluid ejection device includes a fluid slot, a fluid ejection chamber communicated with the fluid slot, a drop ejecting element within the fluid ejection chamber, a fluid circulation channel communicated at one end with the fluid slot and communicated at another end with the fluid ejection chamber, a fluid circulating element within the fluid circulation channel, and a channel wall separating the fluid ejection chamber and the fluid circulation channel. The fluid circulation channel includes a channel loop, and a width of the channel wall is based on a width of the channel loop and a width of the fluid ejection chamber.

A fluid ejection device includes a fluid slot, a first fluid ejection chamber communicated with the fluid slot and including a first drop ejecting element, a second fluid ejection chamber communicated with the fluid slot and including a second drop ejecting element, a fluid circulation path communicated with the first fluid ejection chamber and the second fluid ejection chamber, and a fluid circulating element within the fluid circulation path.

According to an example, a printing system may include a drop ejecting element and a fluid circulating element corresponding to the drop ejecting element. The printing system may also include a logic device that is to receive a data stream addressed to the drop ejecting element, determine whether the data stream indicates that the drop ejecting element is to be energized, and in response to a determination that the data stream does not indicate that the drop ejecting element is to be energized, energize the fluid circulating element.

According to an example, a fluid ejection device may include a fluid feed slot, a plurality of fluid ejection chambers in fluid communication with the fluid feed slot, a plurality of drop ejecting elements, in which a drop ejecting element of the plurality of drop ejecting elements is positioned within each of the plurality of fluid ejection chambers, a fluid circulation channel in fluid communication at a first end of the fluid circulation channel with the fluid feed slot and in fluid communication at multiple second ends of the fluid circulation channel with the plurality of fluid ejection chambers, and a fluid circulating element within the fluid circulation channel. The fluid ejection device may also include a bubble dissipating structure positioned within the fluid circulation channel outside of the plurality of fluid ejection chambers.

A liquid jetting device includes a plurality of nozzles from which a liquid can be ejected, a plurality of pressure chambers, each being in fluid communication with an associated nozzle in the plurality of nozzles, actuators associated with each pressure chamber and configured to cause a pressure change in an associated pressure chamber in the plurality of pressure chambers, a heat-conductive chassis to which the plurality of nozzles, the plurality of pressure chambers, and the actuators are mounted, an integrated circuit held inside the chassis and configured to drive the actuators to eject liquid from the plurality of nozzles, a circuit board electrically connected to the integrated circuit and configured supply an electrical signal to integrated circuit, and a heat-conductive support to which the circuit board is mounted, the heat-conductive support held by the heat-conductive chassis to contact the integrated circuit and an inner surface of the heat-conductive chassis.

Microfluidic delivery systems for dispensing a fluid composition into the air comprising microfluidic die and at least one heating element that is configured to receive an electrical signal comprising a certain on-time and wave form to deliver a fluid composition into the air.

The present disclosure is directed to a microfluidic die that includes a plurality of heaters above a substrate, a plurality of chambers and nozzles above the heaters, a plurality of first contacts coupled to the heaters, and a plurality of second contacts coupled to the heaters. The plurality of second contacts are coupled to each other and coupled to ground. The die includes a plurality of contact pads, a first signal line coupled to the plurality of second contacts and to a first one of the plurality of contact pads, and a plurality of second signal lines, each second signal line being coupled to one of the plurality of first contacts, groups of the second signal lines being coupled together to drive a group of the plurality of heaters with a single signal, each group of the second signal lines being coupled to a remaining one of the plurality of contact pads.