A wafer structure is disclosed and includes a chip substrate and a plurality of inkjet chips. The chip substrate is a silicon substrate fabricated by a semiconductor process. At least one inkjet chip is directly formed on the chip substrate by the semiconductor process and diced into the at least one inkjet chip for inkjet printing. Each of the inkjet chip includes a plurality of ink-drop generators produced by a semiconductor process and formed on the chip substrate. Each of the ink-drop generators includes a thermal-barrier layer, a resistance heating layer, a conductive layer, a protective layer, a barrier layer, an ink-supply chamber and a nozzle.

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.

An inkjet printing apparatus includes: a print head device including an inkjet head to spray a composition for ink including a plurality of bipolar elements; an ink circulation device including an ink storage to store the composition for ink, and transfer the composition for ink to the print head device; an ink injection device to inject the composition for ink into the ink storage; and a temperature adjusting device to adjust a temperature of the composition for ink. The temperature adjusting device includes: a first temperature adjusting device to adjust a temperature to be included in a first reference temperature range; a second temperature adjusting device to adjust a temperature to be included in a second reference temperature range; and a third temperature adjusting device to adjust a temperature to be included in a third reference temperature range.

A fluidic die may include a fluid channel layer defining a number of fluid channels therein, a slot layer disposed on a side of the fluid channel layer, and a first fluid slot and a second fluid slot defined in the slot layer. At least one of the fluid channels fluidically couples the first fluid slot to the second fluid slot. The first fluid slot and the second fluid slot are defined in the slot layer along a length of the fluidic die.

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.

In an example, a machine-readable medium stores instructions which when executed by a processor cause the processor to determine a difference between a measured printed output and an expected printed output. Based on the difference, a first control instruction for controlling a drop size wherein the drop size is variable, and a second control instruction for controlling a dot density of a variable dot density may be determined.

A wafer structure is disclosed and includes a chip substrate and at least one inkjet chip. The chip substrate is a silicon substrate fabricated by a semiconductor process. The inkjet chip is directly formed on the chip substrate by the semiconductor process, whereby the wafer structure is diced, and the inkjet chip is produced, to be implemented for inkjet printing. The inkjet chip includes a plurality of ink-drop generators produced by the semiconductor process and formed on the chip substrate. Each of the ink-drop generators includes a barrier layer, an ink-supply chamber and a nozzle, and the ink-supply chamber and the nozzle are integrally formed in the barrier layer.

A wafer structure is disclosed and includes a chip substrate and at least one inkjet chip. The chip substrate is a silicon substrate fabricated by a semiconductor process on a wafer of at least 12 inches. The inkjet chip is directly formed on the chip substrate by the semiconductor process, whereby the wafer is diced, and the inkjet chip is produced, to be implemented for inkjet printing. The inkjet chip includes plural ink-drop generators produced by the semiconductor process and formed on the chip substrate. The ink-drop generators are arranged in a longitudinal direction to form plural longitudinal axis array groups having a pitch maintained between two adjacent ink-drop generators in the longitudinal direction, and arranged in a horizontal direction to form plural horizontal axis array groups having a central stepped pitch equal to or less than 1/600 inches maintained between two adjacent ink-drop generators in the horizontal direction.

A wafer structure is disclosed and includes a chip substrate and at least one inkjet chip. The chip substrate is a silicon substrate fabricated by a semiconductor process. The inkjet chip is directly formed on the chip substrate by the semiconductor process, whereby the wafer structure is diced, and the inkjet chip is produced, to be implemented for inkjet printing. The inkjet chip includes a plurality of ink-drop generators produced by the semiconductor process and formed on the chip substrate. Each of the ink-drop generators includes a barrier layer, an ink-supply chamber and a nozzle, and the ink-supply chamber and the nozzle are integrally formed in the barrier layer.

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.