The present disclosure relates to a printing apparatus, and the printing apparatus according to the present disclosure includes an optical unit for expanding and displaying a hitting point of ink, from above a substrate; and a nozzle unit for ejecting the ink, wherein the nozzle unit includes a nozzle body that is obliquely disposed with respect to the substrate; and a nozzle that is coupled to the nozzle body, and has a flow path from which the ink is ejected, and has a tip that is bended towards the substrate.

The electrohydrodynamic print head comprises a plurality of nozzles. Each nozzle has a central nozzle duct laterally surrounded by a nozzle wall. The top end of the nozzle duct communicates with an ink feed duct. An annular trench laterally surrounds the nozzle. An extraction electrode is located around the axis of the nozzle at a level below it, and a shaping electrode located laterally outside the nozzle duct. The shaping electrode is arranged within a ring having a horizontal width of less than the vertical distance between said shaping electrode and the extraction electrode or it is located above the trench. Both these measures allow to operate the device with high voltages with reduced risk of electrical breakdown.

There is provided a liquid discharging apparatus including: a liquid discharging head having a nozzle; an electrode; a voltage supplier; a first output part configured to output a first signal corresponding to an electric change, of the electrode or the liquid discharging head, caused in a case that the liquid discharging head performs inspection driving for discharging a liquid from the nozzle toward the electrode; a second output part connected to the electrode; a high pass filter; a third output part connected to the electrode via the high pass filter; and a controller. The controller is configured to: determine whether the liquid is normally discharged based on the first signal; and determine whether a short circuit is formed between the liquid discharging head and the electrode based on a second signal outputted from the second output part and a third signal outputted from the third output part.

The area necessary to install the liquid jet head to be positioned by a positioning mechanism is reduced. An inkjet head is provided with a head main body for jetting ink, a base member which supports the head main body, and is installed on an installation surface of a carriage, and a positioning mechanism which adjusts a position of the base member in a direction along the installation surface with respect to a positioning pin disposed on the installation surface, wherein the positioning mechanism is supported by the base member, and at least a part of the positioning mechanism is arranged inside an outer shape of the base member in a plan view of the installation surface viewed from a vertical direction thereof.

A first supporting member includes a first engaging portion and a second engaging portion that respectively engage with a first engaged portion and a second engaged portion that are provided in a second supporting member. The first engaging portion and the second engaging portion are configured to apply force in directions opposite to the directions in which the first engaged portion and the second engaged portion move when an opening opens.

A liquid ejecting head has a nozzle forming surface to which a nozzle section through which liquid is ejected is open, wherein an electrostatic propensity of the nozzle section due to contact with the liquid is lower than an electrostatic propensity of the nozzle forming surface due to contact with the liquid. The amount of fluorine per unit area in the nozzle section is smaller than the amount of fluorine per unit area in the nozzle forming surface.

A fluid ejection device includes a fluid slot, at least one fluid ejection chamber communicated with the fluid slot, a drop ejecting element within the at least one fluid ejection chamber, a fluid circulation channel communicated with the fluid slot and the at least one fluid ejection chamber, and a fluid circulating element communicated with the fluid circulation channel. The fluid circulating element is to provide on-demand circulation of fluid from the fluid slot through the fluid circulation channel and the at least one fluid ejection chamber.

Provided is a liquid ejection apparatus capable of cooling a control board of a liquid ejection head without cooling a liquid supply path. Ae liquid ejection unit ejects ink onto paper. Ae control board controls the operation of the liquid ejection unit. Ae head housing covers and houses the control board inside thereof. Ae liquid supply path supplies ink to the liquid ejection head. Ae main body housing covers and houses a portion of the liquid ejection head except for the liquid ejection unit. A fan causes air to flow between the main body housing and the head housing. The liquid supply path is inserted from the outside to the inside of the main body housing in the vicinity of the liquid ejection head, and is connected to the liquid ejection head.

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 for operating a printer can include draining a print material from a printer, placing a sacrificial metal into the printer, ejecting the sacrificial metal from a nozzle of the printer, and cooling to printer to a temperature that is below a melting point of the print material and the sacrificial metal. The print material can be or include aluminum and the sacrificial metal can be or include tin. The print material can be drained from the printer when the print material is in molten form, for example, from about 600° C. to about 2000° C. The sacrificial metal can be ejected from the nozzle at a temperature above the melting point of the sacrificial metal but below the melting point of the print material, for example, below about 300° C. The method can reduce or eliminate cracking of various printer structures such as the nozzle during a shutdown or cooling of the printer.