An object is to provide a liquid ejection head and liquid ejection apparatus capable of preventing a deterioration in ink circulation efficiency in the vicinities of ejection ports. To this end, a common supply channel and a common collection channel are provided as separate channels. An ink supplied from the common supply channel is supplied to pressure chambers through supply connection channels, and collected from the pressure chambers into the common collection channel through collection connection channels. Also, the common supply channel and the common collection channel extend in a direction crossing a main scanning direction in which the liquid ejection head is scanned and the ejection direction of the liquid.

A thermal inkjet printing device includes a fluidic die having a thermal sensor and a processor coupled to the fluidic die. The processor is to receive temperature data from the thermal sensor and determine a flow rate of liquid printing agent through the fluidic die based on the temperature data and an operating parameter for the fluidic die.

A fluid jet ejection device, a method of making a fluid jet ejection head, and a method of improving the plume characteristics of fluid ejected from the fluid jet ejection head. The pharmaceutical drug delivery device includes a cartridge body; and a fluid jet ejection cartridge disposed in the cartridge body. The fluid jet ejection cartridge contains a fluid and an ejection head attached to the fluid jet ejection cartridge. The ejection head contains a plurality of fluid ejectors thereon and a nozzle plate having a plurality of fluid ejection nozzles therein associated with the plurality of fluid ejectors. At least one of the plurality of fluid ejection nozzles has an orthogonal axial flow path relative to a plane defined by the nozzle plate and at least one of the plurality of fluid ejection nozzles has an angled axial flow path relative to a plane define by the nozzle plate.

A fluid jet ejection device, a method of making a fluid jet ejection head for a fluid ejection device, and a method of improving the plume characteristics of fluid ejected from the fluid jet ejection head. The fluid jet ejection device includes a cartridge body; and a fluid jet ejection cartridge disposed in the cartridge body. The fluid jet ejection cartridge contains a fluid and an ejection head attached to the fluid jet ejection cartridge. The ejection head contains a plurality of fluid ejectors thereon and a nozzle plate having a plurality of fluid ejection nozzles therein associated with the plurality of fluid ejectors, wherein a first portion of the plurality of fluid ejection nozzles have a first axial flow path length and a second portion of the plurality of fluid ejection nozzles have a second axial flow path length greater than the first axial flow path length.

According to examples, an apparatus may include a pump generator having a first resistance level and being positioned within a fluid circulation channel and a drop generator having a second resistance level and being positioned within a fluid ejection chamber. The apparatus may also include a control line connected to both the pump generator and the drop generator and a controller. The controller may output, at a first time, a first signal having a first pulse duration to the control line, the first signal to cause fluid in the fluid circulation channel to reach or exceed a first temperature and fluid in the fluid ejection chamber to remain below the first temperature and may output, at a second time, a second signal having a second pulse duration, the second signal to cause fluid in the fluid circulation channel and the fluid ejection chamber to reach or exceed the first temperature.

In a case where air bubbles exist in ink at the time of circulating the ink within a liquid ejection module, the amount circulating ink runs short and stability of ejection is blocked. The liquid ejection module has: a pressure chamber that communicates with an ejection port and which stores a liquid; an energy generation element that produces energy for causing a liquid to be ejected from the ejection port; a supply flow path that supplies a liquid to the pressure chamber; a collecting channel that collects a liquid from the pressure chamber; a liquid sending chamber that connects to the collecting channel; a connection flow path that connects the liquid sending chamber and the supply flow path; and a liquid sending unit configured to circulate a liquid, and the liquid sending chamber has a continuously inclined structure.

A fluid-ejection element of a fluid-ejection device includes a chamber layer having a pair of chambers fluidically disconnected from one another within the chamber layer. The fluid-ejection element includes a tophat layer over the chamber layer and fluidically connecting the chambers to define a fluid recirculation path between the chambers. The fluid-ejection element includes a nozzle common to both the chambers.

A fluid-ejection element of a fluid-ejection device includes a chamber layer having a chamber. The fluid-ejection element includes an above-chamber layer fluidically connected to the chamber layer and through which fluid is to recirculate. The fluid-ejection element includes a firing resistor disposed at a bottom of the chamber. The fluid-ejection element includes a nozzle above the chamber through which the firing resistor is to eject the fluid from the chamber.

A fluid ejection die may include a fluid actuator, a substrate supporting the fluid actuator, a chamber layer supported by the substrate and a bypass passage in the substrate. The substrate may include a closed inlet channel having an inlet opening for connection to an outlet of a fluid source and an outlet channel having an outlet opening of a first size for connection to an inlet of the fluid source. The chamber layer includes a recirculation passage to supply fluid for ejection by the fluid actuator through an ejection orifice and to circulate fluid across the fluid actuator from the closed inlet channel to the outlet channel. The bypass passage is of a second size less than the first size and connects the inlet channel to the inlet of the fluid source while bypassing any fluid actuator provided for ejecting fluid through an ejection orifice.

An aspect of the present invention is a liquid ejection apparatus including: a liquid ejection head including a heating element, a first protection layer, a second protection layer that functions as a first electrode, a second electrode that is electrically connected to the first electrode, and an ejection port; and a control unit configured to perform control of setting a potential difference between potentials of the first and second electrodes to a predetermined value by changing at least one of the potentials of the first electrode and the second electrode, in which the control unit sets the potential difference to a first value in a case where printing is performed, and the control unit sets the potential difference to a second value different from the first value and feeds power to at least one of a plurality of the heating elements in a case where printing is not performed.