A liquid ejection apparatus includes a liquid ejection head and a controller. The controller configured to perform: determining whether a discharge failure occurs in a first nozzle; in a case where it is determined that the discharge failure occurs in the first nozzle, determining whether a certain condition is satisfied; in a case where it is determined that the certain condition is satisfied: applying a flushing signal to a second driving element; applying a driving signal to the second driving element; determining whether the discharge failure occurs in a second nozzle; in a case where it is determined that the discharge failure does not occur in the second nozzle, executing a first purge; and in a case where it is determined that the discharge failure occurs in the second nozzle, executing a second purge.

A liquid discharge head includes a flow passage substrate which is formed with individual flow passages, the individual flow passages including nozzles and pressure chambers communicated with the nozzles respectively, the pressure chambers being open on a surface of the flow passage substrate; a sealing member which is adhered to the surface via an adhesive and which seals the pressure chambers; and an actuator substrate which has a piezoelectric layer adhered to a surface of the sealing member on a side opposite to the flow passage substrate via an adhesive and individual electrodes formed on a side opposite to the sealing member with respect to the piezoelectric layer. The sealing member is composed of a material different from a material of the piezoelectric layer; and the surface has an adhesion area to which the sealing member is adhered and a non-adhesion area to which the sealing member is not adhered.

an adhesive having a first amount exists on a side of the first piezoelectric element line, of a joint of the wiring substrate and the pressure chamber substrate or the vibration plate, an adhesive having a second amount that is larger than the first amount exists on a side of the second piezoelectric element line of the wiring substrate, of the joint, and a first discharging element related to the first piezoelectric element line is different from a second discharging element related to the second piezoelectric element line.

A flow path member includes a first substrate having a first surface that has a flow path, and includes a second substrate having a second surface opposing the first surface. In the flow path member in which the first and second substrates are joined together with adhesive provided between the first and second surfaces, a groove is formed in at least one of the first and second surfaces. When the first substrate is viewed from a direction orthogonal to the first surface, the flow path is disposed on a groove inner side. The groove has a first portion having a first depth and a second portion having a second depth shallower than the first depth. The second portion is that portion of the groove existing inside a region surrounded by an outer edge of the first surface and extension lines of two sides that form a flow path corner.

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 head comprises multiple nozzles on an ejection surface. The number n of nozzle rows each comprising a plurality m of nozzles arranged in a direction intersecting a first direction are disposed parallel to each other, where n and m are integers 2 or greater. Between the nozzles of each nozzle row, the nozzles of other of the nozzle rows are located as viewed in the first direction and the plurality of nozzles are located at the number m×n of dot positions. An interval defined by the number of dot positions from a dot position where one nozzle is arranged to a dot position just before a dot position where a next one of the nozzles is arranged in each row is referred to as nozzle pitch. At least one of the rows comprises two or more types of the nozzle pitches varying in the number of the dot positions.

A liquid ejecting head including: an individual flow path row in which a plurality of individual flow paths communicating with a nozzle that ejects a liquid in a first axis direction are arranged in parallel along a second axis orthogonal to a first axis, and a first common liquid chamber communicating with the plurality of individual flow paths, in which each of the plurality of individual flow paths has a pressure chamber that stores a liquid.

A liquid discharge head includes a base plate, a cavity plate located on the base plate and including a cavity, and a piezoelectric actuator substrate located on the cavity plate. The cavity plate includes: a first groove located inside a contact region with the piezoelectric actuator substrate and configured to release an adhesive for bonding the cavity plate and the piezoelectric actuator substrate; and a second groove located in a manner to surround the contact region with the piezoelectric actuator substrate and configured to release the adhesive. The base plate includes a third groove configured to open the first groove to the atmosphere. The third groove is configured to communicate between the first groove and the outside through a first hole communicating with the first groove and a second hole located outside the contact region of the cavity plate and the piezoelectric actuator substrate.

A piezoelectric actuator includes a common electrode on a piezoelectric layer at a first side adjacent to a first surface and extends over a plurality of piezoelectric elements. A plurality of first individual electrodes is on the piezoelectric layer at a second side adjacent to a second surface. Each of the plurality of first individual electrodes is at a piezoelectric element of the plurality of piezoelectric elements, and are not electrically connected together. A first insulating layer is on the common electrode at the first side and extends over the plurality of piezoelectric elements. A plurality of second individual electrodes is on the first insulating layer at the first side. Each of the plurality of second individual electrodes is at a piezoelectric element of the plurality of piezoelectric elements, and overlap centers of the plurality of first individual electrodes. The plurality of second individual electrodes are electrically connected together.

A liquid discharge head includes an individual channel which includes: a nozzle; a pressure chamber; a descender of which one end in the first direction is nearer to the nozzle than the other end; and a second connecting channel connecting a second common channel and the one end of the descender. A central axis of the nozzle is positioned between the second common channel and a central axis of the descender in the second direction. The descender includes a first portion including the one end and a second portion positioned between the pressure chamber and the first portion in the first direction. In an end, of the descender, opposite to the second connecting channel in the second direction, an inner wall defining the one end of the first portion protrudes toward the second connecting channel in the second direction beyond an inner wall defining the second portion.