A liquid discharge head is provided, which includes a nozzle plate which is formed with nozzles, and a channel member which is formed with pressure chambers and connecting channels for connecting the pressure chambers and the nozzles. The connecting channel includes a plurality of portions which have mutually different channel cross-sectional areas. The plurality of portions includes a first portion which is adjacent to the pressure chamber, and a second portion which is adjacent to the first portion, the first portion being interposed between the pressure chamber and the second portion. The first portion has the smallest channel cross-sectional area of those of the plurality of portions. S1≤0.3×S0 and S1≤0.7×S2 are fulfilled (S0: channel cross-sectional are of the pressure chamber, S1: channel cross-sectional area of the first portion, S2: channel cross-sectional area of the second portion).

The present embodiments relate to a printing apparatus capable of mitigating/preventing instances of turbulent deviation of ink jetted from print heads when printing onto a substrate, a severe form of which looks like woodgrain. The printing apparatus can include a jet plate that has a first width and that is disposed between the substrate and a series of print heads. The jet plate can also include a series of apertures formed in the jet plate that each correspond to one or more of the print heads, as well as a cutout portion at a first end of the jet plate that has a second width less than the first width.

A liquid injection device includes a driving circuit supplying, to an actuator, a driving signal including a prior driving pulse and a subsequent driving pulse supplied after the prior driving pulse. Where a speed of a leading tip of a prior liquid pillar injected from the nozzle by the prior driving pulse is V3, a speed of a leading tip of a subsequent liquid pillar injected from the nozzle by the subsequent driving pulse is V4, a time period from start of the injection of the prior liquid pillar until start of the injection of the subsequent liquid pillar is t4a, a difference between a time period from the injection of the prior liquid pillar from the nozzle until division of the prior liquid pillar in the case where the prior driving pulse is supplied to the actuator but the subsequent driving pulse is not supplied to the actuator, and the time period t4a, is t4b, and a time period from start of the injection of the prior liquid pillar until separation of the prior liquid pillar from the nozzle in the case where the prior driving pulse is supplied to the actuator but the subsequent driving pulse is not supplied to the actuator is t3a, t4a≦t3a and V4≧V3×(t4a/t4b+1) are satisfied.

An inkjet head includes an actuator that deforms in response to a drive signal from a drive circuit to change a volume of a pressure chamber to eject ink from a nozzle connected to the pressure chamber. The drive signal includes a main interval during which the ink is ejected and an auxiliary interval during which the ink is not ejected. The main interval includes a first pulse applying a first voltage, a first period maintaining the reference potential, and a second pulse applying a second voltage having a polarity opposite from the first voltage. The auxiliary interval is prior to the main interval and includes a third pulse applying a third voltage having the same polarity as the first voltage and a second period maintaining the reference potential.

A liquid jet device includes a head that discharges liquid to an object; a moving mechanism that moves at least one of the object and the head; and a controller that causes the head to discharge the liquid while moving the at least one of the object and the head in a first direction to form a first row of dots, and causes the head to discharge the liquid while moving the at least one of the object and the head in a second direction opposite the first direction to form a second row of dots that overlaps the first row of dots. The controller causes the center of the first dot in the second row of dots to be shifted from the center of the last dot in the first row of dots by a distance greater than or equal to a distance d.

Methods of ejecting droplets containing a non-Newtonian fluid by an acoustic droplet ejector can include applying a tone burst of focused acoustic energy to a fluid reservoir containing a non-Newtonian fluid at sufficient amplitude to effect droplet ejection according to a tone burst pattern. The tone burst pattern may include three discrete tone burst segments, the first tone burst segment having greater duration than the second and third segments, and third segment having greater duration than the second segment. The exact durations and amplitudes of the tone burst segments can be tuned to influence the ejection properties.

An inkjet head includes a pressure chamber storing ink, a nozzle communicating with the chamber, an actuator ejecting the ink through the nozzle by changing a volume of the chamber, and a circuit outputting a drive signal to the actuator with a drive waveform having a cycle based on a number of gradation levels being used for printing. When printing is performed using three or more gradation levels, the circuit outputs the signal that has a multi-drop drive waveform including two or more first waveforms for ejecting first to (n−1)-th droplets of the ink where n is equal to or greater than 3, a second waveform for ejecting an n-th droplet of the ink, and an intermediate time between the first waveform for ejecting the (n−1)-th droplet and the second waveform for ejecting the n-th droplet. The intermediate time is longer than a time between two adjacent first waveforms.

A method of ink jet printing using an ink jet imaging device including a plurality of nozzles arranged for expelling droplets of an ink by actuation of an ink channel includes the steps of: a) providing a bit map of a spit pattern comprising an arrangement of refresh dots to be printed by each of the plurality of nozzles; and d) printing the bitmap of the spit pattern. The spit pattern includes a plurality of clusters of refresh dots, each cluster including at least two sequential refresh dots expelled from a single nozzle. A spit pattern for use in such a method is disclosed.

A liquid discharge apparatus includes: a head including a pressure chamber and a nozzle, the head configured to discharge a liquid in the pressure chamber from the nozzle; circuitry configured to generate a drive waveform including multiple drive pulses to be applied to the head, the drive waveform successively including, in time series: a non-discharge pulse that does not cause the head to discharge the liquid from the nozzle; a latter discharge pulse after the non-discharge pulse, the latter discharge pulse including a contraction waveform element that contracts the pressure chamber to discharge the liquid from the nozzle; and a contraction waveform including the contraction waveform element that contracts the pressure chamber.

An inkjet printing method may includes a dot pattern printing process of printing a dot pattern group by discharging ink at a preset position of a surface of an object using a nozzle group for forming a dot pattern so that dropped droplets are not in overlap with each other, a connection pattern printing process of printing a connection pattern group by discharging ink at a position between neighboring patterns using a nozzle group for forming a connection pattern so that the same attractive force acts to the neighboring patterns dropped on the surface of the object, and a finishing printing process of finishing a coating of the surface of the object by discharging ink to an area except for neighboring dropped droplets using a nozzle group for finishing so that the same attractive force act to the dropped droplets that are dropped on the surface of the object.