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).

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 print element substrate comprises: a plurality of heaters configured to cause discharge of droplets; a pad array in which a plurality of pads configured to do electrical connection from an outside are arranged; and a plurality of resistance monitor elements configured to measure resistance values of the plurality of heaters, wherein the plurality of resistance monitor elements are arranged along a direction of the pad array.

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.

A liquid ejection head includes a substrate, a heat generating resistor element arranged on the substrate and a flow channel forming member for forming a flow channel. The flow channel forming member has a side wall surrounding at least part of the heat generating resistor element. The heat generating resistor element has a pair of oppositely disposed sides and a pair of electrical connection regions which extend along the respective ones of the pair of sides and are separated from the respective ones of the pair of sides by a distance. The side wall has at least one concave corner which is comprised of a curved surface or a surface extending obliquely to the pair of sides and the heat generating resistor element has at least one convex corner which faces the at least one concave corner of the side wall and is rounded or chamfered.

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.

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.

A print element substrate comprises: a plurality of heaters configured to cause discharge of droplets; a pad array in which a plurality of pads configured to do electrical connection from an outside are arranged; and a plurality of resistance monitor elements configured to measure resistance values of the plurality of heaters, wherein the plurality of resistance monitor elements are arranged along a direction of the pad array.

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.