A print head of a binary continuous jet printer comprising: a plurality of nozzles for producing a plurality of ink jets in a cavity delimited by lateral walls, an upper wall and a lower wall, a sorting unit for separating drops or sections of one or more of the jets intended for printing from drops or sections that do not serve for printing, a slot, which passes through the lower wall, enabling the exit of ink drops intended for printing, a gutter for recovering drops or sections not intended for printing, a conduit for injecting gas into the cavity, and for making this gas circulate, in the cavity, to the plurality of nozzles for producing a plurality of ink jets in the cavity, then to the gutter.

A print head of a binary continuous jet printer comprising: a plurality of nozzles for producing a plurality of ink jets in a cavity delimited by lateral walls, an upper wall and a lower wall, a sorting unit for separating drops or sections of one or more of the jets intended for printing from drops or sections that do not serve for printing, a slot, which passes through the lower wall, enabling the exit of ink drops intended for printing, a gutter for recovering drops or sections not intended for printing, a conduit for injecting gas into the cavity, and for making this gas circulate, in the cavity, to the plurality of nozzles for producing a plurality of ink jets in the cavity, then to the gutter.

According to some examples a substance displacement apparatus may comprise a gas ejection aperture and a deflector arm. The gas ejection aperture may be to direct gas towards a roller having a surface on which a substance is disposed. The deflector arm may be moveable between a first position in which gas is directed away from a target area on the surface of the roller, and a second position in which gas is directed towards the target area on the surface of the roller, thereby to displace at least some of the substance from the surface of the roller within the target area. A method and a print apparatus are also disclosed.

According to some examples a substance displacement apparatus may comprise a gas ejection aperture and a deflector arm. The gas ejection aperture may be to direct gas towards a roller having a surface on which a substance is disposed. The deflector arm may be moveable between a first position in which gas is directed away from a target area on the surface of the roller, and a second position in which gas is directed towards the target area on the surface of the roller, thereby to displace at least some of the substance from the surface of the roller within the target area. A method and a print apparatus are also disclosed.

A method for operating a printhead of a continuous inkjet printer comprising: producing at least one ink jet in a cavity of the print head; electrostatically separating drops or sections of one or more of the jet intended for printing from drops or sections that do not serve for printing; exiting from the cavity drops or sections of ink intended for printing, through a slot open on the outside of the cavity; and circulating at least one flow of air along the outlet slot of the cavity in a direction essentially perpendicular to at least one jet of ink emitted by the printhead and intended for printing. The air having a water vapor pressure lower than the water vapor pressure defined by 100% relative humidity at the coldest temperature of the printer.

A method for operating a printhead of a continuous inkjet printer comprising: producing at least one ink jet in a cavity of the print head; electrostatically separating drops or sections of one or more of the jet intended for printing from drops or sections that do not serve for printing; exiting from the cavity drops or sections of ink intended for printing, through a slot open on the outside of the cavity; and circulating at least one flow of air along the outlet slot of the cavity in a direction essentially perpendicular to at least one jet of ink emitted by the printhead and intended for printing. The air having a water vapor pressure lower than the water vapor pressure defined by 100% relative humidity at the coldest temperature of the printer.

A recording element substrate includes a substrate, a plurality of energy generating elements arranged on the substrate to form an element row, a plurality of supply ports arranged along the element row to form a supply port row, and a plurality of supply paths extending from the plurality of supply ports along the thickness direction of the substrate, wherein a plurality of beam portions disposed between adjacent supply ports in the direction of the supply port row has a plurality of conductor layers in which a conductor layer including a power supply conductor connected to the energy generating elements and a conductor layer including a ground conductor connected to the energy generating elements, are stacked along the thickness direction of the substrate, and wherein at least one of the plurality of conductor layers is occupied by one power supply conductor or one ground conductor.

A drop-on-demand printing method comprising performing the following steps in a printing head: discharging a first primary drop of a first liquid from a first nozzle outlet to move along a first path (pA) with a first speed; discharging a second primary drop of a second liquid from a second nozzle outlet to move along a second path (pB) with a second speed, lower than the first speed, wherein the second path (pB) is inclined with respect to the first path (pB) along an axis inclined at an angle () from 3 to 60 degrees and crosses the first path (pA) at a connection point; controlling the flight of the first primary drop and the second primary drop to combine the first primary drop with the second primary drop into a combined drop at the connection point so that a chemical reaction is initiated between the first liquid of the first primary drop and the second liquid of the second primary drop; applying electric charge to the combined drop; wherein the path of flight (pC) of the combined drop is altered no more than 20 degrees from the axis of the path of flight (pA) of the first primary drop; and controlling the path of flight (pC) of the combined drop with applied electric charge by deflecting electrodes.

A drop-on-demand printing method comprising performing the following steps in a printing head: discharging a first primary drop of a first liquid from a first nozzle outlet to move along a first path (pA) with a first speed; discharging a second primary drop of a second liquid from a second nozzle outlet to move along a second path (pB) with a second speed, lower than the first speed, wherein the second path (pB) is inclined with respect to the first path (pB) along an axis inclined at an angle () from 3 to 60 degrees and crosses the first path (pA) at a connection point; controlling the flight of the first primary drop and the second primary drop to combine the first primary drop with the second primary drop into a combined drop at the connection point so that a chemical reaction is initiated between the first liquid of the first primary drop and the second liquid of the second primary drop; applying electric charge to the combined drop; wherein the path of flight (pC) of the combined drop is altered no more than 20 degrees from the axis of the path of flight (pA) of the first primary drop; and controlling the path of flight (pC) of the combined drop with applied electric charge by deflecting electrodes.

A jetting device may include a vacuum nozzle configured to direct a gaseous flow of a gaseous fluid in flow communication with a jetting outlet; a vacuum pump configured to draw the gaseous flow into the vacuum nozzle and further towards the vacuum pump via the vacuum nozzle outlet; and an inlet conduit between a vacuum nozzle inlet and the ambient environment, where the inlet conduit includes a control valve configured to control a flow rate of the gaseous flow through the vacuum nozzle outlet based on adjusting a smallest diameter of the inlet conduit between an open diameter and a constricted diameter. The open diameter may be greater than a smallest diameter of the suction hole. The gaseous flow may include a first gaseous flow into the vacuum nozzle via a suction hole and an adjustable second gaseous flow into the vacuum nozzle via the vacuum nozzle inlet.