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.

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.

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 fluid ejection device is described. In an example, a device includes a substrate having a chamber formed thereon to contain a fluid. A metal layer includes a resistor under the chamber having a surface thermally coupled to the chamber. At least one layer is deposited on the metal layer. A polysilicon layer is under the metal layer comprising a polysilicon structure under the resistor to change topography of the resistor such that the surface is uneven.

In some examples, a cartridge includes a printhead comprising a fluid feed slot, a fluid chamber formed between a nozzle layer and a passivation layer, the fluid chamber fluidically coupling the fluid feed slot and a nozzle of the nozzle layer, and a printhead-integrated sensor to sense a property of a fluid in the fluid chamber, the sensor including a ground electrode exposed to the fluid chamber through an opening in the passivation layer.

An operation method of a heater device with a memory unit, wherein the heater device includes a plurality of heater circuits, each of the plurality of heater circuits includes a first transistor and a second transistor. In a burning mode, selectively turning on at least one of the first transistors according to a first signal, so that a first current generated by voltage signals coupled to two terminals of the first transistor passes through the memory unit. In a reading mode, sequentially turning on the first transistors to determine states of the memory units. In a heating mode, selectively turning on at least one of the second transistors according to a second signal, so that a second current generated by voltage signals coupled to two terminals of the second transistor passes through a heater.

An ink manifold for use with a heater chip in an inkjet printhead, including a first planar surface and a second opposite planar surface, a plurality of ink channels located on the first planar surface of the ink manifold for supplying ink to the heater chip, and a plurality of ink ports located on the second opposite planar surface of the ink manifold, each of the plurality of ink ports being in liquid communication with a respective one of the plurality of ink channels, each of the plurality of ink channels having a bottom wall defined by bottom wall portions that rise from each ink port within the ink channel to a maximum height at an angle of at least 12 degrees.

An example provides a fluid ejection device including a fluid feed slot, a fluid chamber between a nozzle layer and a passivation layer, and a printhead-integrated sensor to sense a property of a fluid in the fluid chamber. The sensor may include a ground electrode exposed to the fluid chamber through a via in the passivation layer.

A fluid ejection device is described. In an example, a device includes a substrate having a chamber formed thereon to Ncontain a fluid. A metal layer includes a resistor under the chamber having a surface thermally coupled to the chamber. At least one layer is deposited on the metal layer. A polysilicon layer is under the metal layer comprising a polysilicon structure under the resistor to change topography of the resistor such that the surface is uneven.

An example provides a fluid ejection device including a fluid feed slot, a fluid chamber between a nozzle layer and a passivation layer, and a printhead-integrated sensor to sense a property of a fluid in the fluid chamber. The sensor may include a ground electrode exposed to the fluid chamber through a via in the passivation layer.