A heater device with a memory unit includes a first transistor, a second transistor, a memory unit and a heater. The first terminal of the second transistor and the first terminal of the first transistor are electrically connected to each other. The memory unit is electrically connected to the second terminal of the first transistor. The heater is electrically connected to the second terminal of the second transistor.

A liquid ejection head including a base substrate, an ejection port to eject a liquid, a heating element formed above the base substrate that heats the liquid to eject the liquid from the ejection port, a temperature detection element formed above the base substrate that detects a temperature of the liquid, a wiring layer connected to the heating element, a protective layer formed on the base substrate that protects the heating element and the wiring layer from the liquid, and a liquid supply port that penetrates the base substrate and supplies the liquid to the ejection port. When viewed in a direction perpendicular to the base substrate, the temperature detection element is disposed between the heating element and the liquid supply port, and the temperature detection element is formed on the protective layer.

In an example implementation, a method of dual and single drop weight printing includes operating a printing system in a hybrid drop weight print mode to enable ejecting black ink from high drop weight nozzles and low drop weight nozzles, and ejecting color ink from high drop weight nozzles but not from low drop weight nozzles.

Printheads and printers are described herein. In one example, a printhead includes a number of drop generators disposed in a first array and a second array. The drop generators in both the first array and the second array are spaced one dot pitch apart perpendicular to the motion of a print medium, and alternate between a high drop weight (HDW) drop generator and a low drop weight (LDW) drop generator. Each drop generator in the first array is in a line of the motion of the print medium with a corresponding drop generator in the second array, wherein each HDW drop generator in the first array is in line with an LDW drop generator in the second array, and each LDW drop generator in the first array is in line with an HDW drop generator in the second array.

Printheads and printers are described herein. In one example, a printhead includes a plurality of nozzles configured to eject ink drops of different sizes wherein a low drop weight (LDW) drop is ejected through a nozzle with a circular bore (CB), and a high drop weight (HDW) drop is ejected through a nozzle with a non-circular bore (NCB).

A liquid-discharging-head substrate includes an insulation layer, an electrode, and a heating resistor element, wherein the insulation layer includes a first opening portion including a first opening formed in a surface of the insulation layer, a second opening having a smaller opening area than an opening area of the first opening, and a surface connecting the first opening and the second opening, and a second opening portion extending from the second opening to a back surface of the insulation layer, wherein the electrode is formed in the second opening portion, and a surface of the electrode is exposed from the second opening when viewed from the surface side of the insulation layer, and wherein the heating resistor element is in contact with the surface connecting the first opening and the second opening, and with the surface of the electrode.

Printheads and printers are described herein. In one example, a printhead includes a plurality of nozzles configured to eject ink drops of different sizes wherein a low drop weight (LDW) drop is ejected through a nozzle with a circular bore (CB), and a high drop weight (HDW) drop is ejected through a nozzle with a non-circular bore (NCB).

A thermal fluid ejection heating element may include a first conductive trace, and an at least partially perforated resistive thin film material electrically coupling the first conductive trace to a second conductive trace. The perforations within the perforated resistive thin film material defines a resistance of the thermal fluid ejection heating element.

A liquid-discharging-head substrate includes an insulation layer, an electrode, and a heating resistor element, wherein the insulation layer includes a first opening portion including a first opening formed in a surface of the insulation layer, a second opening having a smaller opening area than an opening area of the first opening, and a surface connecting the first opening and the second opening, and a second opening portion extending from the second opening to a back surface of the insulation layer, wherein the electrode is formed in the second opening portion, and a surface of the electrode is exposed from the second opening when viewed from the surface side of the insulation layer, and wherein the heating resistor element is in contact with the surface connecting the first opening and the second opening, and with the surface of the electrode.

Printheads and printers are described herein. In one example, a printhead includes a number of drop generators disposed in a first array and a second array. The drop generators in both the first array and the second array are spaced one dot pitch apart perpendicular to the motion of a print medium, and alternate between a high drop weight (HDW) drop generator and a low drop weight (LDW) drop generator. Each drop generator in the first array is in a line of the motion of the print medium with a corresponding drop generator in the second array, wherein each HDW drop generator in the first array is in line with an LDW drop generator in the second array, and each LDW drop generator in the first array is in line with an HDW drop generator in the second array.