A liquid discharge head unit includes a liquid discharge head that has a first detection resistor that is provided to correspond to a first piezoelectric element group, a second detection resistor that is provided to correspond to a second piezoelectric element group, a power supply circuit that causes a current to flow through the first detection resistor and the second detection resistor, a voltage detection circuit that detects a voltage, and a switching circuit that is configured to switch between a first state in which the voltage detection circuit is configured to detect a voltage generated in the first detection resistor due to the current flowing from the power supply circuit and a second state in which the voltage detection circuit is configured to detect a voltage generated in the second detection resistor due to the current flowing from the power supply circuit.

A distance between the first circuit and the second circuit is a first distance, a distance between the first circuit and the temperature detection circuit is a second distance longer than the first distance, and a distance between the second circuit and the temperature detection circuit is a third distance longer than the first distance.

A head includes: a head unit; and a wiring film configured to be connected to the head unit. The wiring film includes: a flexible substrate; a first IC provided on the flexible substrate; a second IC provided on the flexible substrate; a first wire provided on the flexible substrate to connect the first IC and a first contact portion of the head unit; a second wire provided on the flexible substrate to connect the second IC and a second contact portion of the head unit; and a third wire provided on the flexible substrate. The first IC has a long side extended in a predetermined direction and connected to the first wire, the second IC has a long side extended in the predetermined direction and connected to the second wire, and the first IC and the second IC are aligned along the predetermined direction to be apart from each other.

There is provided a maintenance method of a head unit including a first nozzle array and a second nozzle array, the method including: in a first period, supplying a first driving signal having a first waveform to one first driving element corresponding to one first nozzle belonging to the first nozzle array to eject the liquid from one first nozzle; and supplying a second driving signal having a second waveform to one second driving element corresponding to one second nozzle belonging to the second nozzle array to eject the liquid from one second nozzle; and in a second period, supplying a third driving signal having a third waveform to the one first driving element to eject the liquid from the one first nozzle; and supplying a fourth driving signal having a fourth waveform to the one second driving element to eject the liquid from the one second nozzle.

An inkjet printing system with a droplet measurement apparatus is described herein. The droplet measurement apparatus has a light source with a collimating optical system, an imaging device disposed along an optical path of the collimating optical system, and a droplet illumination zone in the optical path of the collimating optical system, the droplet illumination zone having a varying droplet illumination location, wherein the light source, the imaging device, or both are adjustable to place a focal plane of the imaging device at the droplet illumination location. The droplet measurement apparatus is structured to accommodate at least a portion of a dispenser of the printing system within the droplet illumination zone.

In a printhead control circuit causing a printhead to execute printing, the printhead performing abnormality detection in response to a first signal inputted to a second terminal in a state in which the potential of a first terminal is a first potential and a second signal inputted to the second terminal in a state in which the potential of the first terminal is a second potential, one of the first and second potentials is higher than the potentials of the first and second signals, and a signal circuit is configured to output the first and second signals. The signal circuit outputs the first signal to the second wire electrically coupled to the second terminal in a state in which the first wire is being supplied with a first voltage signal at the first potential and outputs the second signal to the second wire after outputting the first signal in a state in which the first wire is being supplied with a second voltage signal at the second potential, which is different from the first potential, to cause the printhead to execute the abnormality detection in response to the first signal, the second signal, the first voltage signal, and the second voltage signal.

Provided is a printhead that performs printing by supplying a drive signal inputted to a second terminal to a drive element according to print data inputted to a first terminal, the printhead including: the first terminal; the second terminal; a determination circuit configured to perform based on different criteria, first determination to determine, in response to a first signal inputted to the first terminal, whether a potential of the second terminal is normal and second determination to determine, in response to a second signal inputted to the first terminal, whether the potential of the second terminal is normal; and a permission circuit configured to permit printing when the potential of the second terminal is determined to be normal in the first determination and second determination and does not permit printing when the potential of the second terminal is determined to be not normal in the first determination or second determination.

There is provided a head module in which a first direction is a main scanning direction, including: a first nozzle row including a first nozzle; a second nozzle row including a second nozzle; and a third nozzle row including a third nozzle, in which a distance P1 between the first nozzle row and the second nozzle row in the first direction and a distance P2 between the first nozzle row and the third nozzle row in the first direction are expressed as P1:P2=E1:O1 where a value E1 is a positive even number and a value O1 is a positive odd number satisfying O1>E1.

There is provided a liquid discharge apparatus for forming an image on a medium by discharging a liquid, including: a first discharge head that discharges a liquid; and a first temperature indicating section provided in the first surface, in which the first temperature indicating section indicates that a temperature of the first temperature indicating section is lower than a first threshold value in a first state, and indicates that the temperature of the first temperature indicating section is equal to or higher than the first threshold value in a second state, and the first state and the second state change reversibly, and at least a part of the first temperature indicating section overlaps at least a part of the first propagation wiring in a normal direction of the wiring substrate.

A printer is configured to provide a jet of extraction gas that extracts a printing fluid from a printing nozzle in the presence of an electric field that accelerates the extracted printing fluid toward a printing substrate. The printer is also configured to selectively turn the electric field and the jet of extraction gas off and on to enable printing in gas-extraction mode, an e-assisted gas-extraction mode, or an e-jet mode. The jet of gas can be provided by a second nozzle concentric with the printing nozzle. A third nozzle can discharge a focusing gas around the extracted printing fluid.