A liquid ejection head includes a flow channel structure, a supply channel structure, a piezoelectric element, a sealing substrate, and a heater. The flow channel structure defines an ejection channel including an individual channel and a manifold. The individual channel has a nozzle and a pressure chamber in which pressure is applied to liquid for causing the liquid to be ejected from the nozzle. The supply channel structure defines a supply channel configured to allow the liquid to flow therethrough to the ejection channel. The piezoelectric element is positioned on an upper surface of the flow channel structure and facing the pressure chamber via a vibration plate. The sealing substrate is made of a material having a higher thermal conductivity than the supply channel structure. The sealing substrate surrounds the piezoelectric element on the flow channel structure to seal the piezoelectric element. The heater is disposed at the sealing substrate.

A liquid ejection head includes a nozzle surface having a plurality of nozzles, a channel structure stacked on the nozzle surface in a stacking direction, and a supply channel structure formed of a material having a lower thermal conductivity than a material of the channel structure. The channel structure has a liquid ejection channel communicating with the nozzles. The supply channel structure has a supply channel communicating with the liquid ejection channel. The supply channel structure has a covering portion covering at least a portion of an end surface on a side of the channel structure in a width direction orthogonal to the stacking direction.

A liquid ejection head includes a flow channel structure, a supply channel structure, and a particular heater. The flow channel structure defines an ejection channel that leads liquid toward a plurality of nozzles arranged in a nozzle row along a first direction. The supply channel structure defines a supply channel configured to allow liquid to flow therefrom to the ejection channel. The particular heater is configured to heat liquid. The flow channel structure is made of inorganic material having a higher thermal conductivity than material used for the supply channel structure. The flow channel structure includes an end portion protruding outward relative to a side surface of the supply channel structure. The particular heater is disposed at the end portion of the flow channel structure.

A head includes a flow path substrate including a flow path of the liquid in the flow path substrate, a nozzle plate which is attached to the flow path substrate and in which the nozzle is formed, a pressure chamber substrate that is attached to a location facing the nozzle plate with the flow path substrate interposed therebetween and that has a pressure chamber, and a pressure generation portion that operates according to an electrical signal from a wiring substrate coupled to an electrode provided on the pressure chamber substrate and that changes a pressure of the pressure chamber to eject the liquid from the nozzle, in which the nozzle plate and the wiring substrate are disposed such that the nozzle plate does not overlap a coupling portion between the wiring substrate and the electrode when viewed in a thickness direction of the flow path substrate.

A circuit unit includes a circuit board, a cover being configured to house the circuit board inside, a first airflow inlet formed in a first surface of the cover, and a first duct formed in the first surface wherein the first duct is in communication with the first airflow inlet, and a sliding mechanism that supports the circuit unit such that the circuit unit is movable, the sliding mechanism includes a fixed frame, a second airflow inlet formed in the fixed frame, and a second duct that is formed in the fixed frame and in communication with the second airflow inlet, and, when the circuit unit is located at the first position, the first duct and the second duct are engaged with each other such that a third duct is formed to cause the first airflow inlet and the second airflow inlet communicate each other.

A head module includes a base, a plurality of heads mounted on the base, a plurality of wiring members connected to the plurality of heads, the plurality of wiring members mounting a plurality of drive circuits, respectively, and a heat dissipation member thermally coupled to the plurality of drive circuits. The heat dissipation member is disposed facing the plurality of heads and the base, and the heat dissipation member contacts the base at a position between adjacent heads of the plurality of heads.

A liquid ejection head includes: a first head unit; a second head unit disposed adjacent to the first head unit in a first direction and located on a first side of the first head unit in a second direction; and a heat uniforming unit shared by the first head unit and the second head unit. Each of the first head unit and the second head unit includes: a unit body including an actuator; and a first driver integrated circuit disposed on the first side of the unit body in the second direction. The heat uniforming unit includes a first heat uniforming member disposed on the first side of the first head unit and the second head unit in the second direction. The first heat uniforming member includes a first protrusion located next to the second head unit in the first direction and protruding toward the first head unit.

An image forming system includes an image forming unit configured to form a toner image on a recording material; a fixing device configured to fix the toner image on the recording material on which the toner image is formed by the image forming unit; a first cooling unit capable of cooling the recording material passed through the fixing device; a second cooling unit capable of cooling the recording material passed through the first cooling unit; and a control unit configured to carry out control so that during execution of an image forming job, the image forming job is stopped when both the first cooling unit and the second cooling unit are out of order and is continued when either one of the first cooling unit and the second cooling unit is out of order.

There is provided a liquid discharge head including: a communication plate having a plurality of descenders in respective communication with a plurality of nozzles, a pressure chamber plate being stacked on the communication plate and having a plurality of pressure chambers, a piezoelectric element arranged in a position overlapping with the pressure chambers in a stacking direction, and a discharge common channel extending in an array direction and being in communication with the plurality of pressure chambers. The discharge common channel includes: a first discharge portion formed in the communication plate; and a second discharge portion formed in the pressure chamber plate and in communication with the first discharge portion, the second discharge portion reaching as high as to a surface of the pressure chambers at the side of the piezoelectric element along the stacking direction.

A head module includes a head and a cover. The head includes a nozzle plate and a channel substrate. The nozzle plate includes a nozzle configured to discharge liquid from a discharge surface of the nozzle plate. The channel substrate includes an individual channel communicated with the nozzle. The channel substrate has a surface facing the nozzle plate. The cover covers at least one side of the discharge surface of the nozzle plate of the head. An outer shape of the nozzle plate is smaller than an outer shape of the channel substrate. The cover has a bonded surface bonded to the surface of the channel substrate in an outer area of the nozzle plate with an adhesive. The bonded surface of the cover is closer to the channel substrate than the discharge surface of the nozzle plate is.