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.

Disclosed is a liquid ejecting head including a flow passage forming section in which a pressure chamber which communicates with a nozzle ejecting liquid and a circulation liquid chamber which communicates with the pressure chamber to circulate the liquid are formed, a driving element that generates pressure change in the pressure chamber, a circuit board for driving the driving element, and a connecting terminal that electrically connects the driving element with the circuit board, in which the connecting terminal overlaps the circulation liquid chamber in a plan view.

An ink-jet recording apparatus may include an ink-jet head having: individual connection flow channels through which ink can be discharged from pressure chambers; and a common flow channel at which ink from the individual connection flow channels merges, wherein when the ink is ejected, in a nozzle through which the maximum amount of ink per unit time is ejected, the relationship of (Fn/Fi)10 is satisfied, Fn representing the amount of ink ejected per unit time from the nozzle, and Fi representing the average flow rate of ink discharged per unit time from the individual connection flow channels, and the relationship of (Rc/Rt)10 is satisfied, Rc representing the flow channel resistance of the common flow channel, and Rt representing the synthetic resistance of the individual connection flow channels.

According to one or more embodiments, the inkjet head includes an actuator and a driver. The actuator causes a pressure chamber to expand or contract. The driver applies an ejection pulse to the actuator to eject ink from the pressure chamber. The ejection pulse includes an expansion pulse having a width of 0.75 to 1.25 times a pressure propagation time of the pressure chamber, a rest period after the expansion pulse, and a contraction pulse after the rest period.

A liquid ejection head according to the present disclosure includes: a printing element substrate including an ejection surface provided with a first ejection orifice array in which an ejection orifice configured to be capable of ejecting a liquid is arranged in plurality in an array direction and a second ejection orifice array arranged in a direction intersecting with the array direction and the first ejection orifice array; and a protective member provided with a first opening corresponding to the first ejection orifice array and a second opening corresponding to the second ejection orifice array, wherein the protective member is arranged adjacent to the ejection surface of the printing element substrate via an adhesive arranged between the first ejection orifice array and the second ejection orifice array.

A recording method of the present disclosure, which is a recording method of performing recording on a recording medium by using a recording device including an ink jet head, includes ejecting a composition for ink jet from the ink jet head, in which the composition for ink jet contains a metal pigment, the metal pigment is formed of a plurality of scaly metal particles, the ink jet head includes a circulation flow path for circulating the composition for ink jet, and an average thickness of the metal particles determined by atomic force microscopy is 19 nm or less.

A liquid jetting device includes a plurality of nozzles from which a liquid can be ejected, a plurality of pressure chambers, each being in fluid communication with an associated nozzle in the plurality of nozzles, actuators associated with each pressure chamber and configured to cause a pressure change in an associated pressure chamber in the plurality of pressure chambers, a heat-conductive chassis to which the plurality of nozzles, the plurality of pressure chambers, and the actuators are mounted, an integrated circuit held inside the chassis and configured to drive the actuators to eject liquid from the plurality of nozzles, a circuit board electrically connected to the integrated circuit and configured supply an electrical signal to integrated circuit, and a heat-conductive support to which the circuit board is mounted, the heat-conductive support held by the heat-conductive chassis to contact the integrated circuit and an inner surface of the heat-conductive chassis.

According to one embodiment, a liquid ejection head includes an actuator with a plurality of pressure chambers and dummy chambers. The pressure chambers are each part of a groove that is disposed between an adjacent pair of sidewalls. Each pressure chamber is in fluid communication with a nozzle for ejecting a liquid. The dummy chambers are each between an adjacent pair of pressure chambers. A common chamber is fluidly connected to an end of each of the pressure chambers. A throttle portion is at the end portion of each pressure chamber. Each throttle portion blocks a part of a liquid flow path from the first common chamber to the pressure chamber. The first throttle portion is formed of a resin material.

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.

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.