An electrohydrodynamic print head has a plurality of nozzles arranged in a plurality of wells. Extraction electrodes are located around the wells at a level below the nozzles. Further, shielding electrodes are located around the wells at a level below the extraction electrodes. For each well, there are several such shielding electrodes located at different angular positions. This allows to use the shielding electrodes for laterally deflecting the ink after its ejection from the nozzles.

A liquid discharge method of discharging a liquid from a nozzle of a liquid discharge head by applying a drive pulse to a drive element of the liquid discharge head includes an acquisition step of acquiring a recording condition including a first discharge characteristic and a second discharge characteristic of the liquid from the liquid discharge head, a determination step of determining the drive pulse to be applied to the drive element, based on the recording condition, and a driving step of applying the drive pulse determined in the determination step to the drive element. In the liquid discharge method, in the determination step, the drive pulse is determined by a determination method subjected to weighting in which a weight of the first discharge characteristic is greater than a weight of the second discharge characteristic.

A printer includes a nozzle from which a stream of printing fluid is electrostatically extracted and directed toward a printing surface. A diverter can selectively interrupt the stream of printing fluid so that at least some of the extracted printing fluid is not deposited on the printing surface. Another stream of printing fluid can be extracted from another nozzle in a different direction from the first. Respective diverters can selectively and independently interrupt each stream of printing fluid to control which portions of the extracted fluids are deposited over the printing surface. Diverted printing fluid can be collected and reused. The diverters allow for a more constant or uniform extraction field while permitting selective deposition of ink droplets similar to drop-on-demand printing schemes.

An arrayed electrohydrodynamic printhead without the extraction electrodes is provided. A printhead is formed by an ink cartridge, a flow channel plate, a nozzle plate, a control electrode layer. The ink cartridge includes an ink inlet, an ink outlet, an installation hole, a flow channel layer inlet, flow channel layer outlet. The flow channel plate has the functions of guiding the ink to flow into the nozzle plate and increasing the potential difference between the nozzles, and includes a flow channel inlet, a flow channel outlet, a drainage channel, and a microfluidic channel. A body of the nozzle plate includes nozzles and nozzle electrodes. The microfluidic channel forms a voltage division unit between each nozzle, so that the voltage on the triggered nozzle is dispersed in the flow channel without affecting other nozzles, and independent and controllable injection of each nozzle is thereby achieved.

A liquid discharge method of discharging a liquid from a nozzle of a liquid discharge head by applying a drive pulse to a drive element of the liquid discharge head includes an acquisition step of acquiring a recording condition including a first discharge characteristic and a second discharge characteristic of the liquid from the liquid discharge head, a determination step of determining the drive pulse to be applied to the drive element, based on the recording condition, and a driving step of applying the drive pulse determined in the determination step to the drive element. In the liquid discharge method, in the determination step, the drive pulse is determined by a determination method subjected to weighting in which a weight of the first discharge characteristic is greater than a weight of the second discharge characteristic.

An arrayed electrohydrodynamic printhead without the extraction electrodes is provided. A printhead is formed by an ink cartridge, a flow channel plate, a nozzle plate, a control electrode layer. The ink cartridge includes an ink inlet, an ink outlet, an installation hole, a flow channel layer inlet, flow channel layer outlet. The flow channel plate has the functions of guiding the ink to flow into the nozzle plate and increasing the potential difference between the nozzles, and includes a flow channel inlet, a flow channel outlet, a drainage channel, and a microfluidic channel. A body of the nozzle plate includes nozzles and nozzle electrodes. The microfluidic channel forms a voltage division unit between each nozzle, so that the voltage on the triggered nozzle is dispersed in the flow channel without affecting other nozzles, and independent and controllable injection of each nozzle is thereby achieved.

A print head for an inkjet printer includes a nozzle, a first electrode positioned to receive an ink droplet from the nozzle, a second electrode positioned to receive the ink droplet from the first electrode, and a controller configured to operate the first electrode to ionize the ink droplet and set a flight speed of the ink droplet. The controller is further configured to selectively activate the second electrode to deflect the ink droplet in response to the print head changing from a horizontal printing orientation to a vertical printing orientation.

A print head for an inkjet printer includes a nozzle, a first electrode positioned to receive an ink droplet from the nozzle, a second electrode positioned to receive the ink droplet from the first electrode, and a controller configured to operate the first electrode to ionize the ink droplet and set a flight speed of the ink droplet. The controller is further configured to selectively activate the second electrode to deflect the ink droplet in response to the print head changing from a horizontal printing orientation to a vertical printing orientation.

An electrohydrodynamic print head has a plurality of nozzles arranged in a plurality of wells. Extraction electrodes are located around the wells at a level below the nozzles. Further, shielding electrodes are located around the wells at a level below the extraction electrodes. For each well, there are several such shielding electrodes located at different angular positions. This allows to use the shielding electrodes for laterally deflecting the ink after its ejection from the nozzles.

A liquid supply unit that includes a liquid ejection apparatus and configured to be mounted onto a holder unit that has a liquid introducing needle that extends in a first direction includes an outer shell, a liquid supply port, and an engagement structure including a first engagement portion, in which the first engagement portion is disposed on a mounting direction side of the outer shell at a position that overlaps with the outer shell when the liquid supply unit is viewed from the demounting direction side.