A liquid ejecting head includes: a plurality of individual flow channels provided with nozzles; a common supply flow channel through which a liquid is supplied to the plurality of individual flow channels; a common discharge flow channel through which the liquid is discharged from the plurality of individual flow channels; and a bypass flow channel that bypasses the plurality of individual flow channels and causes the common supply flow channel and the common discharge flow channel to communicate with each other. A combined flow channel resistance of the bypass flow channel and the plurality of individual flow channels is greater than a flow channel resistance of the common supply flow channel and is greater than a flow channel resistance of the common discharge flow channel.

A piezoelectric device includes a substrate, a diaphragm; and a piezoelectric actuator, in which the substrate, the diaphragm, and the piezoelectric actuator are laminated in this order in a first direction, the diaphragm includes a first layer containing silicon as a constituent element, a third layer disposed between the first layer and the piezoelectric actuator and containing zirconium as a constituent element, and a second layer disposed between the first layer and the third layer and containing at least one impurity element selected from the group consisting of a metal, a metalloid, and a semiconductor other than silicon and zirconium, as a constituent element, and the impurity element diffuses into the third layer.

The diaphragm includes a first layer containing silicon as a constituent element, a third layer disposed between the first layer and the piezoelectric actuator and containing zirconium as a constituent element, and a second layer disposed between the first layer and the third layer and containing at least one selected from the group consisting of a metal other than iron, silicon, and zirconium, a metalloid, and a semiconductor, as a constituent element, in the second layer and the third layer, a position with a highest concentration of impurities other than the constituent elements of the second layer and the third layer is in the second layer, a position with a highest concentration of zirconium is in the third layer, and a position with a highest concentration of silicon is in the first layer.

A liquid ejecting apparatus includes a first liquid ejecting head configured to eject a liquid to an ejection direction, a sub-carriage that holds the first liquid ejecting head, and a carriage that holds the sub-carriage. The sub-carriage includes: a first member that is thermally conductive and holds the first liquid ejecting head; and a heating section provided in the first member. The first liquid ejecting head includes a first side wall facing the first member. The first member is located between the heating section and the first side wall when viewed in the ejection direction.

A liquid ejection head of a side shooter type includes a plate including nozzles arranged along a first direction and through which liquid is ejected, an actuator including pressure chambers communicating with the nozzles, dummy chambers each disposed between two adjacent pressure chambers, and sidewalls separating the chambers along the first direction and deformable to change a volume of each pressure chamber according to a signal, and covers having apertures and partly covering both ends of each pressure chamber in a second direction intersecting the first direction such that the pressure chambers communicate with a common chamber at both ends thereof through the apertures. Each cover includes a first portion on and between the sidewalls and a second portion other than the first portion, and a first length of the first portion is equal to or greater than a second length of the second portion in the second direction.

In this liquid ejecting head, the pressure chamber extends in a second direction crossing a first direction, the first direction being a direction from the pressure chamber to the nozzle. The pressure chamber and the absorbing chamber are disposed at a same position in the first direction and next to each other in the second direction. The actuator is disposed on an opposite side in the first direction with respect to the pressure chamber. The absorption member is disposed on the opposite side in the first direction with respect to the absorbing chamber, the absorption member including at least part of members constituting the actuator.

There is provided a head unit including: a discharge section that includes a piezoelectric element driven by a first driving signal and discharges a liquid; a switching circuit that switches whether or not to supply the first driving signal; a first substrate that propagates the first driving signal and the discharge control signal to the switching circuit; a second substrate to which the first driving signal and the discharge control signal are supplied and which propagates the first driving signal and the discharge control signal to the first substrate; a first coupling member including a first conductive section that electrically couples the first substrate and the second substrate; and a second coupling member including a second conductive section that electrically couples the first substrate and the second substrate, in which a cross-sectional area of the first conductive section is larger than a cross-sectional area of the second conductive section.

There is provided a head unit including: a discharge section that includes a piezoelectric element driven by a driving signal and discharges a liquid; a first substrate; a second substrate; and a coupling member that electrically couples the first substrate and the second substrate, in which the coupling member includes a pin header having a plurality of insertion pins including a first insertion pin and a second insertion pin, and a holding section that holds the plurality of insertion pins in a state of being insulated, and a pin socket having the same number of a plurality of insertion holes as the plurality of insertion pins, which are provided corresponding to the plurality of insertion pins, and the coupling member electrically couples the first substrate and the second substrate by inserting the plurality of insertion pins into the corresponding plurality of insertion holes.

The control portion controls (i) a discharging operation of discharging the liquid from the plurality of nozzles by driving the plurality of energy generation elements and (ii) a pressurization operation of pressurizing the liquid from the individual flow path side in a state in which the plurality of nozzles are sealed by the sealing portion.

A liquid ejecting head includes a liquid flow channel including nozzles constituting a nozzle row configured to eject a liquid, a dummy flow channel including dummy nozzles constituting a dummy nozzle row not configured to eject liquid, and a closing section formed by an adhesive and closing the dummy flow channel.