There is provided a liquid discharge apparatus, in which a first inductance element included in a first demodulation circuit has a first terminal which a first amplified modulated signal is input, a second terminal which a first driving signal is output, a second inductance element included in a second demodulation circuit has a third terminal which is provided in a fourth side portion, and to which a second amplified modulated signal is input, a fourth terminal which is provided in a fifth side portion that faces the fourth side portion, and from which a second driving signal is output, and a second lead member coupled to the third terminal and the fourth terminal and having a third refraction point and a fourth refraction point, and the first inductance element and the second inductance element are positioned such that the second side portion and the fourth side portion face each other.

A liquid ejecting head control circuit controls a liquid ejecting head and a switching circuit. The liquid ejecting head control circuit includes a drive signal output circuit, and a switching control circuit. The switching control circuit outputs an ejection control signal defining an amount of a liquid to be ejected from a nozzle, a switching timing signal defining switching timing of the switching circuit, and a state selection signal defining a state of the switching circuit in a control period defined by the switching timing signal. The state selection signal for a first time period for which the liquid ejecting head is controlled so as to eject the liquid from the nozzle is different from the state selection signal for a second time period for which the liquid ejecting head is controlled so as not to eject the liquid from the nozzle.

A liquid discharge device includes a plurality of sets of a liquid chamber, a nozzle, a piezoelectric element, and an output waveform generator. The liquid chamber stores a liquid. The nozzle communicates with the liquid chamber. The piezoelectric element causes the liquid in the liquid chamber to be discharged from the nozzle as a droplet in response to application of a voltage to the piezoelectric element. The output waveform generator generates a drive waveform of the voltage applied to the piezoelectric element. The output waveform generator includes an output voltage selector to combine multiple voltages to generate the drive waveform and a slope switching selector to switch a slope of the drive waveform generated by the output voltage selector.

A driving device includes a piezoelectric element, a driving electrode, a first switch that performs switching whether to electrically couple the first wire to the driving electrode, a detection circuit that detects, via a second wire, a vibration produced in the piezoelectric element, a second switch that performs switching whether to electrically couple the second wire to the driving electrode, and a determination circuit that determines a state of the piezoelectric element. The second switch remains off during a first period, remains on during a second period subsequent to the first period, remains off during a third period subsequent to the second period, and remains on during a fourth period subsequent to the third period. The determination circuit determines a state of the piezoelectric element, based on a detection result of the detection circuit in at least part of the fourth period.

An inkjet head includes a pressure chamber storing ink, a nozzle communicating with the chamber, an actuator ejecting the ink through the nozzle by changing a volume of the chamber, and a circuit outputting a drive signal to the actuator with a drive waveform having a cycle based on a number of gradation levels being used for printing. When printing is performed using three or more gradation levels, the circuit outputs the signal that has a multi-drop drive waveform including two or more first waveforms for ejecting first to (n−1)-th droplets of the ink where n is equal to or greater than 3, a second waveform for ejecting an n-th droplet of the ink, and an intermediate time between the first waveform for ejecting the (n−1)-th droplet and the second waveform for ejecting the n-th droplet. The intermediate time is longer than a time between two adjacent first waveforms.

A head drive controller to drive a head to discharge a liquid, the head drive controller includes a drive waveform generator configured to generate a drive voltage waveform to drive the head, a switch coupled to the head and the drive waveform generator, the switch configured to select passing or non-passing of the drive voltage waveform generated by the drive waveform generator to the head. The drive voltage waveform includes a first expansion waveform element to expand a pressure chamber in the head, and a second expansion waveform element to expand the pressure chamber, the second expansion waveform element having a slew rate smaller than a slew rate of the first expansion waveform element.

There are provided a substrate on which a first integrated circuit, a first transistor, and a first inductor element are disposed, and which has a first side and a second side facing each other; a heat sink having a fifth side and a sixth side along the first side; the first integrated circuit, the first transistor, and the first inductor element are positioned in order of the first integrated circuit, the first transistor, and the first inductor element from the first side toward the second side, and the heat sink is fixed to the substrate such that a shortest distance between the fifth side and the first side is shorter than a shortest distance between the sixth side and the first side, and a shortest distance between the first integrated circuit and the fifth side is longer than a shortest distance between the first transistor and the sixth side.

There are provided a first fixing section to a third fixing section that fix a heat sink to a substrate on which a first driving circuit and a second driving circuit are disposed; the first drive circuit includes first transistor and first integrated circuit, and the second drive circuit includes second transistor and second integrated circuit, lengths of the first transistor and the second transistor in the normal direction of the substrate are longer than lengths of the first integrated circuit and the second integrated circuit, the first fixing section and the second fixing section overlap a first virtual straight line that connects the first transistor and the second transistor, and the third fixing section overlaps a second virtual straight line that connects the first integrated circuit and the second integrated circuit to each other.

There is provided a head unit including: a substrate on which a first driving circuit is disposed; a heat sink fixed to the substrate; and heat conductive elastic bodies positioned between the substrate and the heat sink, in which the first driving circuit includes a first integrated circuit, a first amplifier circuit including a first transistor, and a first smoothing circuit that outputs the first driving signal, in which a first heat conductive elastic body is in contact with the heat sink and the first integrated circuit, a second heat conductive elastic body is in contact with the heat sink and the first transistor, and the first heat conductive elastic body and the second heat conductive elastic body are in a form of a gel having flame retardancy and electric insulation property.

There are provided a substrate on which a first integrated circuit, a first transistor, a second integrated circuit, and a second transistor are disposed; a heat sink fixed to the substrate; a first heat conductive elastic body which is in contact with the heat sink and the first integrated circuit; a second heat conductive elastic body which is in contact with the heat sink and the first transistor; a third heat conductive elastic body which is in contact with the heat sink and the second integrated circuit; and a fourth heat conductive elastic body which is in contact with the heat sink and the second transistor, the heat sink has a first recess portion positioned between the first heat conductive elastic body and the second heat conductive elastic body, and a second recess portion positioned between the third heat conductive elastic body and the fourth heat conductive elastic body.