An inkjet printhead includes an inkjet nozzle with a main actuator and a peripheral actuator in a firing chamber. A determination is made as to whether the inkjet nozzle has sat idle, e.g., not firing for a threshold period of time. When the inkjet nozzle has sat idle, both the main actuator and the peripheral actuator are activated to jet at least one ink drop. When the inkjet nozzle has not sat idle, only the main actuator is activated to jet ink drops.

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.

A fluid ejector includes a fluid ejection module having a substrate and a layer separate from the substrate. The substrate includes a plurality of fluid ejection elements arranged in a matrix, each fluid ejection element configured to cause a fluid to be ejected from a nozzle. The layer separate from the substrate includes a plurality of electrical connections, each electrical connection adjacent to a corresponding fluid ejection element.

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

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.

An example provides a fluid ejection apparatus including a first firing resistor and a second firing resistor to selectively cause fluid to be ejected through a single nozzle, and a parasitic resistor arranged to add a parasitic resistance to the first firing resistor.

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.

When cleaning is performed to remove kogation, which is deposited on a heat acting portion, by causing an electrochemical reaction through application of a voltage between an upper electrode and an opposing electrode, a wiring located at a periphery of the opposing electrode occludes hydrogen generated during the cleaning, thereby causing hydrogen embrittlement. A unit configured to heat the wiring connected to the opposing electrode is provided, and is driven during the cleaning or after the cleaning, to thereby force hydrogen out of the wiring. Thus, the hydrogen embrittlement of the wiring is suppressed.

An example provides a fluid ejection apparatus including a first firing resistor and a second firing resistor to selectively cause fluid to be ejected through a single nozzle, and a parasitic resistor arranged to add a parasitic resistance to the first firing resistor.

The present disclosure is directed to a microfluidic die that includes a first larger heater and a second smaller heater is a single chamber. The first heater is configured to form a primary bubble that ejects fluid from a nozzle associated with the chamber. The second heater is configured to form a secondary bubble to prevent blow back caused when the primary bubble bursts and ejects fluid from the nozzle. The first and second heater may be coupled to a single input trace and a single ground trace.