A head cooling device includes a refrigerant supplying portion, a switching portion, and a switch processing portion. The refrigerant supplying portion supplies a refrigerant to each of a plurality of recording heads, which ejects ink, through a supplying path. The switching portion can switch a corresponding supplying path of at least one of the plurality of recording heads. The switch processing portion controls the switching portion to switch the corresponding supplying path so as to decrease the temperature difference among the plurality of recording heads.

A liquid discharge head includes a flow channel member, a pressurization part, a plurality of discharge holes, a flexible substrate, a cover member, and a heater. The flow channel member includes a first surface and a second surface that is positioned on an opposite side of the first surface. The pressurization part is positioned on the first surface. The plurality of discharge holes are positioned on the second surface. For the flexible substrate, a one-end part thereof that is positioned on the pressurization part is electrically connected to the pressurization part. The cover member covers the one-end part of the flexible substrate. The heater is positioned on the cover member.

A liquid discharging apparatus includes a head unit having a liquid discharging head that has a driving element, a position detection circuit that outputs a position information signal indicative of a position of the liquid discharging head, a first circuit that controls drive of the driving element based on a first signal, and a first conversion circuit that converts a first optical signal into the first signal; and a driving circuit having a second circuit that outputs a second signal, a second conversion circuit that converts the second signal into the first optical signal, a first cable, and a second cable, in which the first cable connects the first conversion circuit to the second conversion circuit, and propagates the first optical signal, and the second cable electrically couples the position detection circuit to the second circuit, and propagates the position information signal.

A method for processing water-based low-viscosity liquid inkjet inks for digital, contactless inkjet printing, wherein the inkjet ink is applied from systematically arranged nozzles in a time-dependent and location-dependent manner and divided into individual volume units, characterized in that the inkjet ink at the nozzle outlet is or is being cooled to temperatures below the temperature of the ambient air. A device for processing water-based low-viscosity liquid inkjet inks for digital, contactless inkjet printing, comprising at least one print head, whereby inkjet inks are applicable from systematically arranged nozzles in a time-dependent and location-dependent manner and divided into individual volume units, characterized in that the print head and/or the inkjet ink supplied to the print head is coolable.

There are provided a liquid jet head capable of dealing with jet of a variety of types of liquid, and at the same time superior in easiness in handling. The liquid jet head includes a main body part having a liquid jet head chip and a cooling section, and an inflow side connection unit and an outflow side connection unit each configured so as to selectively be attached to and detached from the main body part. As the inflow side connection unit, it is possible to select the first inflow side cover unit and the second inflow side cover unit. As the outflow side connection unit, it is possible to select the first outflow side cover unit and the second outflow side cover unit.

There is provided a liquid discharge apparatus including: a discharging member including a plurality of individual electrodes arranged side by side in a first direction, a plurality of individual channels arranged side by side in the first direction, a plurality of nozzles arranged side by side in the first direction, a common channel communicating with the plurality of individual channels, and an opening communicating with the common channel; and a heating member at least a part of which makes contact with the discharging member. An individual electrode, included in the plurality of individual electrodes and located at an end in the first direction, and the opening are apart from each other in the first direction. At least the part of the heating member is a part making contact with the discharging member, at a location between the opening and the individual electrode located at the end in the first direction.

There is provided a liquid discharge head including a first channel unit and a second channel unit. The first channel unit includes: a first joining surface; a tube disposed on an opposite surface opposite to the first joining surface; an outside portion; and a coupling portion. The second channel unit is joined to the first joining surface. An end of the outside portion and an end of the coupling portion in an orthogonal direction orthogonal to the first joining surface extend to an identical position in the orthogonal direction. The tube includes a circumferential portion that is exposed outside and extends in the orthogonal direction to the identical position to which the end of the outside portion and the end of the coupling portion extend.

A liquid discharge head includes a plurality of pressure generating elements configured to generate pressure to discharge a liquid, a plurality of wirings configured to transmit a drive signal to the plurality of pressure generating elements, respectively, a plurality of integrated circuits configured to drive the plurality of pressure generating elements, respectively, the plurality of integrated circuits being provided on the plurality of wirings, respectively, and a heat sink configured to contact the plurality of integrated circuits to dissipate heat in the plurality of integrated circuits. The heat sink includes a first dissipation part that directly contacts one of the plurality of integrated circuits, and a second dissipating part that contacts another of the plurality of integrated circuits via one of the plurality of wirings.

Provided is a droplet discharging device that can efficiently couple a droplet discharging head and a head driving circuit by a cable. A droplet discharging device includes a droplet discharging head, a head driving circuit configured to drive the droplet discharging head, a carriage configured to move while supporting the droplet discharging head and the head driving circuit, and a cable configured to electrically couple a head connector of the droplet discharging head and a circuit connector of the head driving circuit, the cable being detachably coupled to the head connector and to the circuit connector. The droplet discharging head and the head driving circuit are disposed such that the head connector and the head driving circuit do not overlap in a direction of pull-out of the cable from the head connector and the circuit connector and the droplet discharging head do not overlap in a direction of pull-out of the cable from the circuit connector.

A head unit including: an inkjet head that ejects ink; and a fixer to which the inkjet head is fixed, wherein an engaging part is provided to be fixed to one of the inkjet head and the fixer, and an engaged part is provided to be fixed to the other, the inkjet head is fixed to the fixer by engaging the engaging part and the engaged part, and in the engaging part or the engaged part, a rigidity of a portion including one part of an engagement surface on which the engaging part and the engaged part engage with each other is lower than a rigidity of the other portion.