An ink discharge device including an ink, an ink discharge head, and a negative pressure generator is provided. The ink comprises water, a colorant, an organic solvent X having a solubility parameter of from 8.9 to 12.0 and comprising no glycol ether compound, and a copolymer comprising a structural unit represented by the following formula (1): ##STR00001##
where R1 represents a hydrogen atom or methyl group and Y represents an alkylene group having 2 to 18 carbon atoms. The ink discharge head includes a nozzle to discharge the ink, a plurality of individual liquid chambers in communication with the nozzle, a flow-in channel to let the ink flow into the individual liquid chambers, and a flow-out channel to let the ink flow out from the individual liquid chambers. The negative pressure generator is configured to generate a negative pressure that lets the ink flow out from the individual liquid chambers.

A liquid ejecting head unit includes: a plurality of liquid ejecting heads that have a nozzle-formed surface; and a unit base that has a bottom portion having a fixing surface to which the plurality of liquid ejecting heads are fixed, and a wall portion which extends from the bottom portion in a direction perpendicular to the fixing surface and which is continuous in a direction in which the plurality of liquid ejecting heads are aligned.

A method of operating an electrostatic ink jet printhead, the printhead comprising: one or more ejection tips from which, in use, ink is ejected, the one or more ejection tips defining a tip region; a printhead housing, the printhead housing defining a cavity in which the one or more ejection tips are located; the method comprising the steps of, during a printing operation, passing a vapour into the cavity to reduce evaporation of ink in the tip region.

A liquid-discharging head includes a pressure-generating element configured to be actuated to apply pressure on liquid in a pressure chamber from which the liquid is discharged through a nozzle, an actuation controller configured to control actuation of the pressure-generating element, a heat-releasing member configured to contact the actuation controller, and a cover member configured to cover the actuation controller and part of the heat-releasing member. The heat-releasing member includes a first heat-releasing member and a second heat-releasing member. The first heat-releasing member is arranged outside the cover member and has a surface exposed to external air. The second heat-releasing member is arranged inside the cover member and has a first end portion to contact the actuation controller. The first heat-releasing member and the second heat-releasing member are arranged to contact each other.

A liquid droplet ejecting apparatus includes a liquid droplet ejecting head that includes a plurality of nozzles from which a liquid supplied from a liquid supply source through a liquid supply path is ejected as a liquid droplet, and ejects the liquid droplet from the nozzle to a recording medium to perform a recording process, a first detecting section that detects a vibration waveform of the pressure chamber, which is vibrated when an actuator is driven to cause the pressure chamber communicating with the nozzle to vibrate, to detect a state inside the pressure chamber, and a second detecting section that reads a pattern formed on the recording medium by ejecting the liquid droplet from the nozzle to detect an ejection state of the liquid droplet.

An ink discharge device including an ink, an ink discharge head, and a negative pressure generator is provided. The ink comprises water, a colorant, an organic solvent X having a solubility parameter of from 8.9 to 12.0 and comprising no glycol ether compound, and a copolymer comprising a structural unit represented by the following formula (1):

##STR00001##

where R1 represents a hydrogen atom or methyl group and Y represents an alkylene group having 2 to 18 carbon atoms. The ink discharge head includes a nozzle to discharge the ink, a plurality of individual liquid chambers in communication with the nozzle, a flow-in channel to let the ink flow into the individual liquid chambers, and a flow-out channel to let the ink flow out from the individual liquid chambers. The negative pressure generator is configured to generate a negative pressure that lets the ink flow out from the individual liquid chambers.

A droplet discharging device according to an embodiment of the present disclosure includes an object holding unit configured to hold an object, at least one first droplet discharging nozzle configured to discharge a first droplet, a plurality of second droplet discharging nozzles having a second tip having a second inner diameter smaller than a first inner diameter of a first tip of the first droplet discharging nozzle and configured to discharge a second droplet using the first droplet discharged from the first droplet discharging nozzle, and a driving unit configured to control a relative positional relationship between the object held by the object holding unit and the second droplet discharging nozzle and a relative positional relationship between the first droplet discharging nozzle and the second droplet discharging nozzle.

A printhead includes a plurality of firing chambers, a plurality of fluid ejectors, and at least one field generating member. Each one of the firing chambers includes a nozzle region to receive printing fluid. The printing fluid includes an ink vehicle having pigments disposed therein. At least one field generating member generates a non-uniform electric field to apply forces to maintain respective pigments in the ink vehicle of the printing fluid in the nozzle region.

A liquid-discharging head includes a pressure-generating element configured to be actuated to apply pressure on liquid in a pressure chamber from which the liquid is discharged through a nozzle, an actuation controller configured to control actuation of the pressure-generating element, a heat-releasing member configured to contact the actuation controller, and a cover member configured to cover the actuation controller and part of the heat-releasing member. The heat-releasing member includes a first heat-releasing member and a second heat-releasing member. The first heat-releasing member is arranged outside the cover member and has a surface exposed to external air. The second heat-releasing member is arranged inside the cover member and has a first end portion to contact the actuation controller. The first heat-releasing member and the second heat-releasing member are arranged to contact each other.

A liquid ejecting apparatus includes: a liquid ejecting unit that ejects a liquid supplied through a liquid supply path from a nozzle; a maintenance unit that performs a maintenance operation of the liquid ejecting unit; and an ejection state detecting unit that is able to detect a state inside a pressure chamber communicating with the nozzle. The ejection state detecting unit detects a state inside the pressure chamber before the maintenance operation and at least one state inside the pressure chamber during the maintenance operation or after the maintenance operation, and is able to determine malfunction of at least one of the maintenance unit and function units arranged in the liquid supply path based on a change in a state inside the pressure chamber due to the maintenance operation.