A liquid discharge head, comprising an insulating member arranged on a substrate, a resistive heating element arranged in the insulating member and configured to generate thermal energy used to discharge a liquid, a bubble chamber provided above the insulating member and configured to generate bubbles of the liquid based on the thermal energy, and a temperature detection element capable of detecting a temperature in the bubble chamber, wherein the temperature detection element is arranged between the resistive heating element and the bubble chamber and in a conductive layer closest to the bubble chamber in a plurality of conductive layers provided with respect to the insulating member.

A print element substrate, comprising a base, a heater provided on the base and configured to generate heat used to discharge ink, a flow path member, which forms an ink flow path, configured to form, together with the base, a bubbling chamber in which the ink is bubbled by the heat of the heater provided in a bottom surface of the bubbling chamber, and a temperature sensor capable of detecting a temperature of the bubbling chamber, the temperature sensor being formed of the same material as the heater and provided in the same layer as the heater on the base.

An element substrate of a liquid ejection head includes an ejection element for ejecting a liquid, a plurality of electrode pads for receiving power for causing the ejection element to eject the liquid, and a sensor for detecting that the liquid has invaded the vicinity of the plurality of electrode pads. The sensor has first wiring connected with one electrode pad of the plurality of electrode pads and second wiring connected with one electrode pad different from the electrode pad connected with the first wiring.

An element substrate has a layered structure including a heating resistance element, a first insulation layer where a temperature detection element constituted by a via is formed, and a second insulation layer provided between the heating resistance element and the temperature detection element which electrically insulates the heating resistance element and the temperature detection element.

A fluid ejection device includes a number of primitives, each receiving a same set of addresses and including a number of ejection chambers, each corresponding to a different address of the set of addresses and including a drive bubble formation mechanism and a drive bubble detect (DBD) mechanism. Input logic receives nozzle column data groups (NCG), each NCG including fire pulse groups (FPG), each FPG including DBD data having an enable value or disable value, and ejection data bits, each ejection data bit corresponding to a different one of the primitives. For each FPG of each NCG, activation logic identifies the FPG as a DBD FPG when the DBD data has the enable value and activates in each primitive the drive bubble formation mechanism and the DBD mechanism identified by the DBD FPG to perform a DBD measurement.

In various examples, a fluid ejection device may include a substrate with a fluid feed hole and a corrosion-detecting conductive path or sensor disposed behind a wall of the fluid feed hold. The corrosion-detecting conductive path or sensor may close a circuit in response being exposed to a fluid contained within the fluid feed hole.

Example implementations relate to controllers and printers to operate at least one liquid ejection device of a printhead; the liquid ejection device comprising a nozzle and an associated print liquid chamber bearing a transducer to eject print liquid from the nozzle in response to a firing signal; the print chamber being fluidically coupled to a nozzle supply channel; the at least one liquid ejection device comprising a channel coupled to the print liquid chamber and the nozzle supply channel; the channel having a respective actuator to urge print liquid through the print chamber in response to a circulation signal; wherein the controller comprises temperature control circuitry to actuate the respective actuator using a temperature control signal to increase the temperature of print liquid in the print liquid chamber.

A fluidic die including fluid chambers, each including an electrode exposed to an interior of the fluid chamber and each having a corresponding fluid actuator operating at a first voltage level. Monitoring circuitry, operating at a second voltage level lower than the first voltage level, includes a select transistor and a pulldown transistor for each fluid chamber to selectively couple to the electrode, at least the select transistor being a high voltage tolerant transistor to operate at the second voltage in a normal operating condition and having a breakdown voltage level greater than the first voltage level to prevent a fault current from flowing into the select transistor from the electrode in a fault condition if the fluid actuator short-circuits to the electrode.

According to examples, an apparatus may include a fluidic chamber, in which fluid is to be temporarily held. The apparatus may also include a heating component to generate heat to form a drive bubble in the fluid held in the fluidic chamber and a cavitation plate may be provided between the fluidic chamber and the heating component. The cavitation plate may be in communication with the fluidic chamber and may physically separate the fluidic chamber from the heating component to protect the heating component. In addition, a controller may determine a condition in the fluidic chamber based on an electrical signal received from the cavitation plate.

Misalignment of printing positions is reduced in a print head that circulates an ink between a printing apparatus and the print head in a case where the misalignment is apt to change dynamically along with heat deformation. To this end, printing element substrates in the print head are adjusted to a target temperature and then a liquid is circulated through the print element substrates. After thermal expansion of the print head reaches a steady state, an amount of misalignment of printing positions in a direction of conveyance of the print head is obtained by using a test pattern printed by using printing elements. Further, a correction value for correcting the misalignment of the printing positions is set based on the obtained amount of misalignment of the printing positions.