A flow path member includes a first substrate, a second substrate, bonding adhesive, and recessed portions. The first substrate has a first surface formed with an opening of a flow path. The second substrate has a second surface facing the first surface. The bonding adhesive bonds the first and second surfaces together. The recessed portions are formed in at least one of the first surface of the first substrate and the second surface of the second substrate. Each recessed portion is a hole configured to take up excess bonding adhesive and, as a non-through hole, does not extend through the entire thickness of a substrate. Each of the recessed portions extends into the first substrate or the second substrate as a rectangular column or an elliptical column and, when a shape of each recessed portion is viewed from the direction orthogonal to the first surface, the shape is approximately isotropic.

There is provided a liquid discharge apparatus including: a head including a nozzle configured to discharge a liquid, and a driver element configured to apply a pressure to the liquid; a tank configured to store the liquid; a circulation channel configured to circulate the liquid between the head and the tank; a pump; and a controller. The controller is configured to carry out: a non-discharge flushing process of performing a non-discharge flushing by driving the driver element such that the liquid is not discharged from the nozzle; a switching process of switching the pump between ON and OFF; and a determining process of determining a frequency of driving the driver element in the non-discharge flushing process according to a circulation flow amount of the liquid changing due to the switching of the pump between ON and OFF in the switching process.

There is provided a liquid discharging head including: supply manifolds; a supply integration channel which extends linearly along an arrangement direction crossing a longitudinal direction of the supply manifolds; return manifolds; and a return integration channel which extends linearly along the arrangement direction. The supply integration channel has a supply port arranged apart from the supply manifolds, being configured to supply liquid to the supply integration channel via the supply port, and at least a part of the supply port being overlapped, in a plan view, with a pressure chamber-arranging area in which pressure chambers communicating with nozzles are arranged. The return integration channel has a return port arranged apart from the return manifolds, being configured to drain the liquid from the return integration channel via the return port, and at least a part of the return port being overlapped, in the plan view, with the pressure chamber-arranging area.

A liquid discharging head includes: individual channels; a first common channel; and a second common channel Each of the plurality of individual channels includes: a pressure chamber, a nozzle, a connecting channel, a first communicating channel, and two second communicating channels. A first vector of the first communicating channel has an orientation from one end to the other end of the first communicating channel. Respective second vectors of the two second communicating channels have orientations, each of the orientations being from one end to the other end of one of the two second communicating channels along an extending direction of the two second communicating channels. The first communicating channel is arranged, with respect to the nozzle, on one side in a second direction orthogonal to the first direction, and the two second communicating channels are arranged, with respect to the nozzle, on the other side in the second direction. Each of the orientation of the first vector and the orientation of the second vector includes an orientation component from the one side toward the other side in the second direction.

Provided is a piezoelectric ceramic composition including a potassium sodium niobate-based perovskite type complex oxide represented by Compositional Formula ABO.sub.3, as a main component. Further, the piezoelectric ceramic composition contains Bi in an A site and Zr in a B site. Further, the piezoelectric ceramic composition includes a segregation portion positioned in a crystal grain. At least one of Zr or Bi is localized in the segregation portion.

A liquid ejecting head includes a channel forming body including a plurality of individual channels, a first manifold and a second manifold. The plurality of individual channels includes: a nozzle; a pressure chamber which is arranged to be apart from the nozzle in a first direction; a descender communicating the pressure chamber and the nozzle with each other, and extending in the first direction; a return channel including a first return channel and a second return channel, extending in a direction crossing the first direction, and having one end connected to the descender; and a communicating channel including a first communicating channel, and connecting the other end of the return channel to the second manifold. The first communicating channel connects the first return channel to the second manifold and connects the second return channel to the second manifold.

A first active region is made of a piezoelectric overlaps a midsection of a pressure chamber when viewed in plan through a pressure applying surface. A second active region is made of a piezoelectric member closer than the first active region to the pressure applying surface. The second active region extends over both a peripheral section of the pressure chamber and an outer region located outside the pressure chamber when viewed in plan through the pressure applying surface. A driver controls intensity of a first electric field applied to the first active region and intensity of a second electric field applied to the second active region such that the time period over which the first active region contracts and the time period over which the second active region contracts overlap or coincide with each other. The first electric field is more intense than the second electric field.

A head chip prevented from deteriorating in printing quality is provided. The head chip is provided with an intermediate plate which has a plurality of columns of communication hole groups for each channel column, the communication hole group having communication holes individually communicated with ejection channels of an actuator plate and arranged in a line in an X direction. The communication holes adjacent to each other in the X direction are arranged so as to be shifted in a Y direction from each other. The intermediate plate is provided with a non-penetrating groove closed by a nozzle plate, and a penetrating hole communicated with the non-penetrating groove, and communicated with an outside of the head chip through a non-ejection channel. A part of the non-penetrating groove is located in an inter-communication hole region. A minimum gap in the X direction between an opening edge of the communication hole and the non-penetrating groove in the inter-communication hole region is larger than a minimum gap in the X direction between the opening edge of the communication hole and the non-ejection channel.

A liquid discharging head is provided with: individual channels; a first common channel; and a second common channel. The individual channels include: first individual channels which have first pressure chambers and which are aligned in a second direction to form a first individual channel array, and second individual channels which have second pressure chambers and which are aligned in the second direction to form a second individual channel array; the first individual channel array and the second individual channel array are arranged in a third direction. The first common channel communicates with both of the first individual channels and the second individual channels; and the first pressure chambers and the second pressure chambers do not overlap with the second common channel in a first direction, and do not overlap with each other in the second direction.

A liquid discharge head includes a head body, a plurality of driver ICs, a flexible substrate, and a wiring board. The head body includes a discharge hole configured to discharge a liquid. The plurality of driver ICs controls drive of the head body. The plurality of driver ICs are mounted at the flexible substrate, and the flexible substrate is electrically connected to the head body. The wiring board includes a plurality of connectors. In addition, the flexible substrate includes: a plurality of protruding portions configured to protrude in the same direction and each including a tip portion to be inserted into corresponding one of the plurality of connectors; and a slit formed between the protruding portions adjacent to each other and extending up to a region between the driver ICs adjacent to each other.