In some examples, a controller receives impedance sensor values from an impedance sensor in a printhead, determines whether the impedance sensor values correlate to a production of an effective drive bubble for the printhead, and issues a command to modify a firing parameter for a fluid ejector of the printhead based on the impedance sensor values.

Methods and apparatuses for controlling aerosol streams being deposited onto a substrate via pneumatic shuttering. The aerosol stream is surrounded and focused by an annular co-flowing sheath gas in the print head of the apparatus. A boost gas flows to a vacuum pump during printing of the aerosol. A valve adds the boost gas to the sheath gas at the appropriate time, and a portion of the two gases is deflected in a direction opposite to the aerosol flow direction to at least partially prevent the aerosol from passing through the deposition nozzle. Some or all of the aerosol is combined with that portion of the boost gas and sheath gas and is exhausted from the print head. By precisely balancing the flows into and out of the print head, maintaining the flow rates of the aerosol and sheath gas approximately constant, and keeping the boost gas flowing during both printing and shuttering, the transition time between printing and partial or full shuttering of the aerosol stream is minimized. The pneumatic shuttering can be combined with a mechanical shutter for faster operation. A pre-sheath gas can be used to minimize the delay between the flow of gas in the center and the flow of gas near the sides of the print head flow channel.

Methods and apparatuses for controlling aerosol streams being deposited onto a substrate via pneumatic shuttering. The aerosol stream is surrounded and focused by an annular co-flowing sheath gas in the print head of the apparatus. A boost gas flows to a vacuum pump during printing of the aerosol. A valve adds the boost gas to the sheath gas at the appropriate time, and a portion of the two gases is deflected in a direction opposite to the aerosol flow direction to at least partially prevent the aerosol from passing through the deposition nozzle. Some or all of the aerosol is combined with that portion of the boost gas and sheath gas and is exhausted from the print head. By precisely balancing the flows into and out of the print head, maintaining the flow rates of the aerosol and sheath gas approximately constant, and keeping the boost gas flowing during both printing and shuttering, the transition time between printing and partial or full shuttering of the aerosol stream is minimized. The pneumatic shuttering can be combined with a mechanical shutter for faster operation. A pre-sheath gas can be used to minimize the delay between the flow of gas in the center and the flow of gas near the sides of the print head flow channel.

Methods and apparatuses for controlling aerosol streams being deposited onto a substrate via pneumatic shuttering. The aerosol stream is surrounded and focused by an annular co-flowing sheath gas in the print head of the apparatus. A boost gas flows to a vacuum pump during printing of the aerosol. A valve adds the boost gas to the sheath gas at the appropriate time, and a portion of the two gases is deflected in a direction opposite to the aerosol flow direction to at least partially prevent the aerosol from passing through the deposition nozzle. Some or all of the aerosol is combined with that portion of the boost gas and sheath gas and is exhausted from the print head. By precisely balancing the flows into and out of the print head, maintaining the flow rates of the aerosol and sheath gas approximately constant, and keeping the boost gas flowing during both printing and shuttering, the transition time between printing and partial or full shuttering of the aerosol stream is minimized. The pneumatic shuttering can be combined with a mechanical shutter for faster operation. A pre-sheath gas can be used to minimize the delay between the flow of gas in the center and the flow of gas near the sides of the print head flow channel.

Methods and apparatuses for controlling aerosol streams being deposited onto a substrate via pneumatic shuttering. The aerosol stream is surrounded and focused by an annular co-flowing sheath gas in the print head of the apparatus. A boost gas flows to a vacuum pump during printing of the aerosol. A valve adds the boost gas to the sheath gas at the appropriate time, and a portion of the two gases is deflected in a direction opposite to the aerosol flow direction to at least partially prevent the aerosol from passing through the deposition nozzle. Some or all of the aerosol is combined with that portion of the boost gas and sheath gas and is exhausted from the print head. By precisely balancing the flows into and out of the print head, maintaining the flow rates of the aerosol and sheath gas approximately constant, and keeping the boost gas flowing during both printing and shuttering, the transition time between printing and partial or full shuttering of the aerosol stream is minimized. The pneumatic shuttering can be combined with a mechanical shutter for faster operation. A pre-sheath gas can be used to minimize the delay between the flow of gas in the center and the flow of gas near the sides of the print head flow channel.

A print head of a continuous ink jet printer comprising: a cavity for the circulation of jets, at least one nozzle for producing at least one ink jet or solvent in the cavity, at least one electrode for sorting drops or segments of one or several of the jets intended for printing from drops or segments that are not used for printing, an outlet slot of the cavity, open onto the exterior of the cavity and allowing the exiting of the drops or segments of ink intended for printing, a 1.sup.st gutter for recovering drops or segments not intended for printing, a 2.sup.nd gutter for recovering drops or segments that are not deflected and not intended for printing, this 2.sup.nd gutter being mobile and comprising an input slot and at least one suction channel, a motor, to actuate the 2.sup.nd gutter for recovering in movement between a retracted position, in which it does not close off the outlet slot of the cavity, and a closed position, in which its input slot faces the outlet slot of the cavity; a seal between the print head and the 2.sup.nd gutter for recovering in the closed position of the latter.

A print head of a continuous ink jet printer comprising: a cavity for the circulation of jets, at least one nozzle for producing at least one ink jet or solvent in the cavity, at least one electrode for sorting drops or segments of one or several of the jets intended for printing from drops or segments that are not used for printing, an outlet slot of the cavity, open onto the exterior of the cavity and allowing the exiting of the drops or segments of ink intended for printing, a 1.sup.st gutter for recovering drops or segments not intended for printing, a 2.sup.nd gutter for recovering drops or segments that are not deflected and not intended for printing, this 2.sup.nd gutter being mobile and comprising an input slot and at least one suction channel, a motor, to actuate the 2.sup.nd gutter for recovering in movement between a retracted position, in which it does not close off the outlet slot of the cavity, and a closed position, in which its input slot faces the outlet slot of the cavity; a seal between the print head and the 2.sup.nd gutter for recovering in the closed position of the latter.

There is provided a liquid ejecting apparatus including: a head having a nozzle; a signal outputting part having an electrode and configured to output a signal indicating a magnitude of an electric change in the electrode; and a controller. The controller is configured to execute a determination as to whether or not the nozzle is normal based on the signal output from the signal outputting part in a case that the controller drives the head so as to eject a liquid droplet from the nozzle toward the electrode. The controller is configured to determine that the nozzle is normal in a case that the magnitude of the electric change is within a predetermined normal range, and to determine that the nozzle has a first abnormality in a case that the magnitude of the electric change is greater than the normal range.

There is provided a liquid ejecting apparatus including: a head having a nozzle; a signal outputting part having an electrode and configured to output a signal indicating a magnitude of an electric change in the electrode; and a controller. The controller is configured to execute a determination as to whether or not the nozzle is normal based on the signal output from the signal outputting part in a case that the controller drives the head so as to eject a liquid droplet from the nozzle toward the electrode. The controller is configured to determine that the nozzle is normal in a case that the magnitude of the electric change is within a predetermined normal range, and to determine that the nozzle has a first abnormality in a case that the magnitude of the electric change is greater than the normal range.

An ink set including a first ink containing a pigment and a water-soluble resin having an anionic group, a second ink containing substantially no pigment and a reactive component, and a third ink containing a polymer emulsion and a water-soluble resin having an anionic group. The pKa of the reactive component is lower than the pKa of the anionic group of the water-soluble resin in the first ink and higher than the pKa of the anionic group of the water-soluble resin in the third ink.