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.

There is provided liquid discharging head including; channel member which includes plates stacked in a first direction and adhered to each other via adhesive, and in which individual channels each including nozzle and pressure chamber communicated with the nozzle is formed. The plates include first plate and second plate adhered to adhesion surface of the first plate via the adhesive. Hollows each construct one of the individual channels are opened in the adhesion surface. The hollows are arranged side by side in second direction orthogonal to the first direction in the adhesion surface, and three or more grooves are formed in the adhesion surface between two of the hollows adjacent to each other in the second direction, each of the three or more grooves extending in third direction which is orthogonal to the first direction and which crosses the second direction.

A liquid ejection head includes an ejection-port defining member and a substrate having at least three liquid supply openings arranged in an array direction. The substrate has at least one groove in a region between ends of the liquid supply openings and an edge of the substrate. The groove extends from and communicates with the end of at least one of two outermost liquid supply openings of the liquid supply openings in the array direction. The groove extends at least to a position where the groove is superposed on the liquid supply opening next to the liquid supply opening communicating with the groove in an extending direction in which the liquid supply openings extend.

A liquid in the vicinity of a nozzle is efficiently circulated. A liquid ejecting head includes: a nozzle plate provided with a first nozzle; a flow channel forming unit provided with a first pressure, a first communication channel through which the first nozzle and the first pressure chamber communicate with each other, and a circulating liquid chamber. The nozzle plate is provided with a first circulation channel through which the first communication channel and the circulating liquid chamber communicate with each other.

In a liquid ejecting head, a reduction in mechanical strength due to a liquid chamber provided to circulate a liquid is limited.

The liquid ejecting head includes: a nozzle plate provided with a nozzle; a flow channel forming unit provided with a pressure chamber to which a liquid is supplied, a communication channel through which the nozzle and the pressure chamber communicate with each other, and a circulating liquid chamber communicating with the communication channel; and a pressure generating unit that generates a pressure change in the pressure chamber. A height at a first location in the circulating liquid chamber is larger than a height at a second location on a side of the communication channel when viewed from the first location.

In one example, a process for making a micro device assembly includes placing a micro device on a front part of a printed circuit board, molding a molding on the printed circuit board surrounding the micro device, and then forming a channel to the micro device in a back part of the printed circuit board.

An object of the present invention is to provide an ink jet head and the like that are small, are capable of achieving a higher resolution, increasing ejection stability, and lowering production costs, and include flow paths capable of circulating ink. An ink jet head of the present invention includes: a head chip including nozzles, pressure chambers that communicate with the respective nozzles, piezoelectric elements that correspond to the respective pressure chambers, discrete circulation flow paths that branch from ink flow paths extending from inlets of the pressure chambers to outlets of the nozzles and are capable of discharging the ink in the pressure chambers, and a common circulation flow path with which at least two of the discrete circulation flow paths communicate; and a common supply liquid chamber that is provided on the upper surface of the head chip, and stores the ink to be commonly supplied to the respective pressure chambers through ink supply holes formed in the upper surface of the head chip.

According to one embodiment, a liquid ejection head, includes a piezoelectric member having grooves extending lengthwise in a first direction. The grooves separate the piezoelectric member into piezoelectric elements spaced from each other in a second direction. A connection portion of the piezoelectric member is under a portion of the grooves in a third direction and connects the piezoelectric elements to each other. Individual electrodes are on a first surface of the piezoelectric member on a first side. A common electrode is on a second surface of the piezoelectric member on a second side. Each groove has a depth on the first side that is deeper than a depth in an end portion on the second side. The depth of each groove in the end portion on the first side reaches through the piezoelectric member to a substrate.

A liquid ejecting apparatus is provided with pressure generating units for pressure chambers one of which is provided for each of a plurality of nozzles and drives the pressure generating units corresponding to liquid ejection requests which request liquid ejection from the nozzles while achieving supplying of a liquid to the pressure chambers and collection of the liquid which has passed through the pressure chambers. Accordingly, the liquid is ejected from the nozzles. Meanwhile, an occurrence of a fault in the liquid ejection is determined using a vibration transition of a residual vibration which occurs in the liquid of the pressure chambers according to a pressure change accompanying driving of the pressure generating units, and driving of the pressure generating unit of an ejection fault pressure chamber in which it is determined that a fault occurs in the liquid ejection is stopped spanning at least a fixed stopping period.

A liquid discharging head includes a first flow path member comprising a first flow path and a pressure chamber; a second flow path member stacked on the first flow path member and comprising a second flow path; a wiring substrate comprising a connection terminal for electrically connected to a driving element to generate a pressure change in the pressure chamber; and a circulation flow path for circulating the liquid through the pressure chamber. A surface of the first flow path member includes a first region which is stacked on the second flow path member via the wiring substrate and a second region which is stacked on the second flow path member without the wiring substrate. The first flow path and the second flow path are in communication with each other in the second region so as to be the circulation flow path.