Abstract: A method for causing fluid to be ejected from a fluid chamber of a jet in a printhead. An actuator is actuated with a first energy imparting pulse to push fluid away from the actuator and toward a nozzle. Following a lapse of a first interval, the actuator is actuated with second energy imparting pulse to push fluid away from the actuator and toward the nozzle. Following a lapse of a second interval as measured from the second energy imparting pulse, the actuator is actuated with a break-off pulse to cause fluid extending out of an orifice of the nozzle to break off from fluid within the nozzle, wherein the second lapse is longer than the first lapse and is an inverse of the meniscus-jet mass frequency.

Abstract: A method for causing fluid to be ejected from a fluid chamber of a jet in a printhead. An actuator is actuated with a first energy imparting pulse to push fluid away from the actuator and toward a nozzle. Following a lapse of a first interval, the actuator is actuated with second energy imparting pulse to push fluid away from the actuator and toward the nozzle. Following a lapse of a second interval as measured from the second energy imparting pulse, the actuator is actuated with a break-off pulse to cause fluid extending out of an orifice of the nozzle to break off from fluid within the nozzle, wherein the second lapse is longer than the first lapse and is an inverse of the meniscus-jet mass frequency.

Abstract: In general, in an aspect, a laser produces a coherent beam to illuminate ink jetted from an orifice of an inkjet, for use in imaging the jetted ink, and a device is used to reduce an effect of speckle caused by the coherent beam in the imaging of the jetted ink.

Abstract: A method of cleaning an outer surface of a fluid ejector includes dispensing a cleaning fluid onto the outer surface of the fluid ejector, drying a region of the outer surface of the fluid ejector, and moving the region in a path across the outer surface of the fluid ejector to cause evaporation of the cleaning fluid along a front that moves across the outer surface of the fluid ejector A method of cleaning a surface of a fluid ejector includes dispensing a cleaning fluid onto the outer surface of the fluid ejector, the cleaning fluid including a solvent and carrier liquid that is more wettable to residue of fluid ejected from nozzles of the fluid ejector than the solvent and having a higher vapor pressure than the solvent, and evaporating the carrier liquid such that a concentration of solvent on the surface of the fluid ejector increases.

Abstract: A method for causing fluid to be ejected from a fluid chamber of a jet in a printhead. An actuator is actuated with a first energy imparting pulse to push fluid away from the actuator and toward a nozzle. Following a lapse of a first interval, the actuator is actuated with second energy imparting pulse to push fluid away from the actuator and toward the nozzle. Following a lapse of a second interval as measured from the second energy imparting pulse, the actuator is actuated with a break-off pulse to cause fluid extending out of an orifice of the nozzle to break off from fluid within the nozzle, wherein the second lapse is longer than the first lapse and is an inverse of the meniscus-jet mass frequency.

Abstract: The first plurality of nozzles and the second plurality of nozzles in a fluid ejection system are arranged in a plurality of nozzle pairs, each nozzle pair of the plurality of nozzle pairs including a first nozzle from the first plurality of nozzles and an associated second nozzle from the second plurality of nozzles, the first nozzle and associated second nozzle of each nozzle pair spaced apart in a second direction perpendicular to a first direction, the first direction being the direction of movement of a print media, by greater than zero and less than the pixel pitch p and spaced apart in the first direction. A controller is configured to cause the first nozzle and the second nozzle of each nozzle pair to deposit droplets at the same pixel in a line of pixels.

Abstract: A fluid ejector head includes a die with a plurality of fluid ejector units, each fluid ejector unit comprising a pumping actuator having a drive electrode, and a manifold that contacts the first side of the die to define a module volume in fluidic communication with a drainage volume. The module volume is defined in part between the manifold and at least a portion of plurality of fluid ejector units, and the drainage volume is located apart from the fluid ejector units. The module volume, in comparison to the drainage volume, has a greater ratio of interior surface area to volume or has a greater percentage of interior surface area covered by a non-wetting coating.

Abstract: A method of determining whether a flow path is ready for ejection includes supplying liquid to the flow path, which includes a pumping chamber and a nozzle, after supplying fluid to the flow path, applying energy to an actuator adjacent to the pumping chamber, measuring an electrical characteristic of the actuator to obtain a measured value, and comparing the measured value to a threshold value to determine if the flow path is ready for ejection.

Abstract: A fluid ejector head includes a die with a plurality of fluid ejector units, each fluid ejector unit comprising a pumping actuator having a drive electrode, and a manifold that contacts the first side of the die to define a module volume in fluidic communication with a drainage volume. The module volume is defined in part between the manifold and at least a portion of plurality of fluid ejector units, and the drainage volume is located apart from the fluid ejector units. The module volume, in comparison to the drainage volume, has a greater ratio of interior surface area to volume or has a greater percentage of interior surface area covered by a non-wetting coating.

Abstract: The first plurality of nozzles and the second plurality of nozzles in a fluid ejection system are arranged in a plurality of nozzle pairs, each nozzle pair of the plurality of nozzle pairs including a first nozzle from the first plurality of nozzles and an associated second nozzle from the second plurality of nozzles, the first nozzle and associated second nozzle of each nozzle pair spaced apart in a second direction perpendicular to a first direction, the first direction being the direction of movement of a print media, by greater than zero and less than the pixel pitch p and spaced apart in the first direction. A controller is configured to cause the first nozzle and the second nozzle of each nozzle pair to deposit droplets at the same pixel in a line of pixels.

Abstract: A fluid ejector head includes a die with a plurality of fluid ejector units, each fluid ejector unit comprising a pumping actuator having a drive electrode, and a manifold that contacts the first side of the die to define a module volume in fluidic communication with a drainage volume. The module volume is defined in part between the manifold and at least a portion of plurality of fluid ejector units, and the drainage volume is located apart from the fluid ejector units. The module volume, in comparison to the drainage volume, has a greater ratio of interior surface area to volume or has a greater percentage of interior surface area covered by a non-wetting coating.

Abstract: Among other things, for ink jetting, a system includes a printhead including at least 25 jets and an imaging device to capture image information for all of the jets simultaneously, the captured image information being useful in analyzing a performance of each of the jets.

Abstract: In one aspect, the invention features assemblies for depositing droplets on a substrate during relative motion of the assembly and the substrate along a process direction. The assemblies include a first printhead module and a second printhead module contacting the first printhead module, each of the printhead modules including a surface that includes an array of nozzles through which the printhead modules can eject fluid droplets, wherein each nozzle in the first printhead module's nozzle array is offset with respect to a corresponding nozzle in the second printhead module's nozzle array in a direction orthogonal to the process direction.

Abstract: In one aspect, the invention features assemblies for depositing droplets on a substrate during relative motion of the assembly and the substrate along a process direction. The assemblies include a first printhead module and a second printhead module contacting the first printhead module, each of the printhead modules including a surface that includes an array of nozzles through which the printhead modules can eject fluid droplets, wherein each nozzle in the first printhead module's nozzle array is offset with respect to a corresponding nozzle in the second printhead module's nozzle array in a direction orthogonal to the process direction.

Abstract: In general, in one aspect, the invention features a method, including measuring a surface profile of a substrate, generating firing instructions for a droplet ejection device based on the surface profile, and depositing droplets on the substrate with the droplet ejection device according to the instructions.

Abstract: Techniques for printing charged droplets are described herein.

Abstract: In general, in one aspect, the invention features a method, including measuring a surface profile of a substrate, generating firing instructions for a droplet ejection device based on the surface profile, and depositing droplets on the substrate with the droplet ejection device according to the instructions.

Abstract: An apparatus for depositing droplets on a substrate is disclosed. The apparatus includes a support for the substrate, a droplet ejection assembly which includes a pumping chamber, a controller and a source of static pressure to maintain the total pressure in the pumping chamber above a threshold pressure level to avoid rectified diffusion type bubble growth in the pumping chamber. The droplet ejection assembly is positioned over the support for depositing the droplets on the substrate and includes, in addition to a pumping chamber, a displacement member and an orifice that ejects the droplets. The controller provides signals to the displacement member to eject drops.

Abstract: A drop ejector includes a channel proximate a nozzle opening to control fluid flow.

Abstract: In general, in one aspect, the invention features a method for driving a droplet ejection device having an actuator, including applying a multipulse waveform that includes two or more drive pulses to the actuator to cause the droplet ejection device to eject a single droplet of a fluid, wherein a frequency of the drive pulses is greater than a natural frequency, fj, of the droplet ejection device.