The communication plate has a first layer that defines a wall surface of the communication flow channel, a second layer stacked on a side of the first layer opposite to the wall surface, and a third layer stacked on a side of the second layer opposite to the first layer, and the thermal expansion coefficient of the second layer is smaller than the thermal expansion coefficient of the first layer and is smaller than the thermal expansion coefficient of the third layer.

There is provided a liquid discharge apparatus configured to discharge a liquid, including a channel member for the liquid. The channel member is formed to include: individual channels; a first and second manifold channels; and a bypass channel. Each of the individual channels and the bypass channel are all connected to the first manifold channel on only one of an upper and lower sides of a central portion between upper and lower surfaces of the first manifold channel, and connected to the second manifold channel on only one of upper and lower sides of a central portion between upper and lower surfaces of the second manifold channel. A channel resistance of the bypass channel is smaller than that of the individual channels.

A channel member of a liquid ejection head includes an ejection surface, an outer peripheral surface that is connected to an outer edge of the ejection surface and that faces outside of the ejection surface in a direction along the ejection surface, and a plurality of ejection holes that open in the ejection surface. The channel member includes a plurality of concave portions in the outer edge of the ejection surface, the plurality of concave portions being recessed in the ejection surface and being recessed in the outer peripheral surface. With the configuration, it is possible to collect, in the concave portions, a liquid (such as ink mist) that has leaked out from the ejection holes.

An ink discharge apparatus includes a discharge head and a controller, the discharge head having a plurality of nozzle rows arranged in a first direction, each of the plurality of nozzle rows including a plurality of nozzles arranged to align in a second direction intersecting the first direction. The controller is configured to receive a print job and carry out a mode determining process to determine whether a print mode is a low gap print mode or a high gap print mode based on the print job, and a number of discharge reducing process to reduce the total number of discharging ink per unit time from the plurality of nozzles as compared with the case of the low gap print mode, if the print mode is determined as the high gap print mode.

There is provided a liquid discharge head including: a plurality of nozzles arranged in a first direction; a plurality of pressure chambers; a plurality of throttles; and a common channel extending in the first direction and connected to the plurality of throttles. The common channel has: a supply port, and a terminal part which is at least one of both end parts in the first direction of the common channel, the supply port being not provided at the terminal part. A terminal throttle which is one of the plurality of throttles and which is positioned closest to the terminal part among the plurality of throttles has a channel resistance same as a channel resistance of a throttle of the plurality of throttles different from the terminal throttle, and extends from a connection between the terminal throttle and one of the plurality of pressure chambers to the terminal part.

A liquid discharging head includes: individual channels; a first common liquid chamber provided commonly for the individual channels; and a second common liquid chamber provided commonly for the individual channels. Liquid is supplied from the first common liquid chamber to the individual channels and the liquid flows into the second common liquid chamber from the individual channels. Each of the individual channels has: a pressure chamber; a first channel; a nozzle connected to the first channel and configured to discharge the liquid; a second channel separated from the nozzle in a first direction and connecting the pressure chamber and the first channel; and a third channel connected to the first channel on a side opposite to the second channel in the first direction with the nozzle sandwiched between the third channel and the second channel.

Printheads for a jetting apparatus. In one embodiment, a printhead comprises a plurality of flow-through jetting channels each configured to jet a print fluid out of a nozzle. The printhead further includes a supply manifold fluidly coupled to the flow-through jetting channels, a return manifold fluidly coupled to the flow-through jetting channels, and one or more bypass manifolds fluidly coupled between the supply manifold and the return manifold.

Printheads and design of printheads. In one embodiment, a printhead comprises a plurality of jetting channels, and a manifold apparatus fluidly coupled to the jetting channels. For each jetting channel, the printhead includes a first fluid path between the jetting channel and the manifold apparatus, and a second fluid path between the jetting channel and the manifold apparatus. The jetting channel is configured to jet a print fluid via pressure waves generated in a pressure chamber of the jetting channel. Lengths of the first fluid path and the second fluid path are different by a threshold length so that an arrival time of the pressure waves at the manifold apparatus are different by a threshold time.

A liquid discharge head includes: nozzles aligned on a nozzle surface; a supply manifold configured that a liquid is supplied therein from the outside of the liquid discharge head; a return manifold which is arranged between the nozzle surface and the supply manifold in a first direction, which is configured that the liquid is flown out therefrom to the outside of the liquid discharge head, and which is provided with a return damper part; and individual flow channels each of which corresponds to one of the nozzles. Each of the individual flow channels has a return throttle channel communicating the corresponding nozzle with the return manifold and being arranged between the return manifold and the nozzle surface in the first direction. The return manifold has a compliance larger than a compliance of the supply manifold.

A liquid discharge head includes a channel unit. The channel unit is formed therein with: a plurality of individual channels aligning in a first direction, a common channel extending in the first direction, a supply hole in communication with the common channel, and a damper chamber provided in a position overlapping with the supply hole in a second direction orthogonal to the first direction. The channel unit includes a first plate having a first surface where a recess is formed to constitute the damper chamber, and a second plate having a second surface attached to the first surface via an adhesive. A protrusion is provided on a bottom of such a first part of the recess as overlaps with the supply hole in the second direction.