Abstract: In an image forming apparatus, a liquid ejection head has at least one ejection hole, and a conveyor moves a recording medium relative to the ejection head. A deflector deflects liquid droplets ejected from the ejection hole in a direction including at least a component of a direction substantially parallel to relative conveyance direction of the recording medium. A deflection angle setter sets two or more deflection angles such that when dots mutually adjacent in the direction substantially parallel to the relative conveyance direction of the medium are formed in an overlapping fashion, directions of flight of droplets ejected consecutively are deflected such that their directions of flight become different from each other. Droplet landing time differential between the first droplet and the second droplet becomes equal to or greater than quasi-fixing time period from a landing time of the first liquid droplet until the first liquid droplet becomes quasi-fixed.

Abstract: The formation and manipulation of microbubbles, microdroplets and films of (preferably) flowable materials, such as liquids and gases, are used to beneficially control or modulate acoustic-energy propagation, electromagnetic-energy propagation or electrical potential and current application. A droplet, bubble or film causes at least one of reflection, refraction, diffraction, attenuation, sapping, scattering, dissipation, redirection, conversion or blocking of at least one component of the energy due to the droplet, bubble or film causing a propagation discontinuity, disruption or energy-barrier to the energy. The energy comprises at least one of acoustic, electrical, electromagnetic, magnetic, kinetic, mechanical, chemical, RF, thermal, pneumatic, hydraulic or non-visible optical energy.

Abstract: A fluid ejection device, a method of cleaning the device, and a method of operating the device are provided. The device includes a substrate having a first surface and a second surface located opposite the first surface. A nozzle plate is formed over the first surface of the substrate and has a nozzle through which fluid is ejected. A drop forming mechanism is situated at the periphery of the nozzle. A fluid chamber is in fluid communication with the nozzle and has a first wall and a second wall. The first wall and the second wall are positioned at an angle other than 90° relative to each other. A fluid delivery channel is formed in the substrate and extends from the second surface of the substrate to the fluid chamber. The fluid delivery channel is in fluid communication with the fluid chamber.

Abstract: An ink-jet printer includes an ink-jet head which includes a nozzle, a main liquid droplet trapping section 30 which traps only a main liquid droplet, and a cover member which surrounds a space in which a satellite liquid droplet which is jetted from a nozzle at the same time when the main liquid droplet is jetted, flies. It is possible to suppress a decline in an accuracy of a landing position of the satellite liquid droplet, caused due to a change in a trajectory of flying of the satellite liquid droplet due to an effect of a flow of air in the space. Accordingly, it is possible to provide a liquid droplet jetting apparatus which is capable of controlling accurately the landing position of a very small satellite liquid droplet.

Abstract: A method and apparatus for forming fluid droplets includes a nozzle channel, a pressurized source of a non-conductive fluid in fluid communication with the nozzle channel, and a stimulation electrode. The pressurized source is operable to form a jet of the non-conductive fluid through the nozzle channel. At least one portion of the stimulation electrode is electrically conductive and contactable with a portion of the non-conductive fluid jet. The at least one electrically conductive and contactable portion of the stimulation electrode is operable to transfer an electrical charge to a region of the portion of the non-conductive fluid jet with the electrical charge stimulating the non-conductive fluid jet to form a non-conductive fluid droplet.

Abstract: A method of forming a liquid pattern according to liquid pattern data on a receiving medium using a liquid drop emitter that emits a continuous stream of liquid from a nozzle that is broken into drops of predetermined volumes by the application of drop forming energy pulse is disclosed comprising associating a pixel area of the receiving medium with a nozzle and a time interval during which a plurality of fluid drops ejected from the nozzle can impinge the pixel area of the receiving medium. The time interval is divided into a plurality of subintervals that are, in turn, grouped into a plurality of blocks. Each block is defined as a printing block or a non-printing block. A drop forming energy pulse is provided between each pair of consecutive blocks and between the subintervals of each printing block. No drop forming energy pulses are provided between the subintervals of the non-printing blocks.

Abstract: An inkjet printer having an array of nozzles from which ink drops are emitted further includes a mechanism adapted to detect fluid levels in an ink supply tank to the inkjet printer while the printer is in idle mode, and shut down the printer when ink usage exceeds a predetermined volume.

Abstract: A continuous inkjet print head jets a plurality of fluid streams from an array of multiple nozzle channels. The print head includes a flow conditioning means that establishes fully developed flow in one or more regions of the print head such that substantially equal flow conditions are created at each of the inlets of the multiple nozzle channels. The substantially equal flow conditions reduce nozzle-to-nozzle variations with respect to the required trajectories of the jetted fluids to improve jet pointing and thus lead to better print quality.

Abstract: A droplet generator comprising a first unit having an elongate liquid chamber one end thereof is open and at least one raw of orifices disposed in a line oppositely to the open end in the longitudinal direction of the first unit, a second unit having an elongate diaphragm provided on the bottom of the second unit and a plurality of vibrators provided within the diaphragm area, a vibrating apparatus provided on the top of the vibrators, and a stationary section to fix the vibrating apparatus. The diaphragm of the second unit is provided closely and oppositely to the open end of the liquid chamber of the first unit.

Abstract: A device, method and system for causing a controlled collapse of cavities formed within liquid droplets wherein a pressurized jet comprising a liquid and nanoparticle material and possibly fuel produces droplets from the breakup of the jet stream. The liquid droplets are irradiated with energy to produce and expand cavities formed within the droplets by irradiation of the nanoparticles contained within the droplets. The droplets are collided with a target to collapse the cavities within the droplets. The irradiating and colliding are timed to enhance implosion energy resulting from the cavities' collapse. The implosion energy and the fuel in the cavity may be used to activate and sustain a fusion reaction.

Abstract: A method and apparatus for inkjet printing by means of a plurality of inkjet nozzles arranged in at least one row and having spaced, parallel nozzle axes for emitting liquid ink drops towards the substrate, and multi-level charging and deflecting plates controlled to deflect individual drops to selected locations on the substrate with respect to the respective nozzle axis according to the pattern to be printed. The multi-level charging and deflecting plates are controlled to cover, for each nozzle, a line section which includes two non-contiguous deposit zones to receive ink drops from the respective nozzle, separated by a non-deposit zone not to receive ink drops from the respective nozzle.

Abstract: A continuous stream ink jet printer is provided having an ink droplet forming mechanism for ejecting a stream of ink droplets having a selected one of at least two different volumes toward a print medium and a droplet deflector and ink conduit which are integrally formed to the printhead for producing a flow of gas that interacts with the ink droplet stream to separate droplets having different volumes and collects all droplets not used for printing. The provision of integrally forming the gutter system with the droplet forming mechanism eliminates the requirement to align an external gutter system upon full print engine assembly.

Abstract: An ink jet recording apparatus in which a filter unit to filter ink with a filter having a pore size of 2.2 to 5.8 ?m is provided in an ink supply channel to supply the ink to an ink jet head. The ink flowing through the ink supply channel is quickly filtered by the filter unit, and supplied to the ink jet head without delay, thus the occurrence of ink discharge failure can be reliably suppressed.

Abstract: A printing system includes a catcher having a length with portions of the catcher defining a fluid drop contact region and an opening for passage of the fluid away from the fluid contact region with the opening having two ends. A fluid drop generator is operable to form fluid drops at least some of which contact the fluid drop contact region of the catcher. An eyelid is operatively associated with the catcher. A pair of walls are positionable at locations outside of the ends of the opening such that the pair of walls and the eyelid are operable to form a fluid seal at least partially around the opening of the catcher. A first portion of the each of the pair of walls extends in a first direction toward the fluid drop generator, and a second portion of each of the pair of walls extends in a second direction at least partially toward each other.

Abstract: A drop deflector apparatus for a continuous drop emission system that deposits a liquid pattern on a receiver according to liquid pattern data comprising a plurality of drop nozzles formed along a nozzle array axis and emitting a plurality of continuous streams of a liquid that breaks up into a plurality of streams of drops having nominal flight paths that are substantially parallel and substantially within a nominal flight plane is disclosed. An airflow plenum having an evacuation end connected to a negative pressure source and an impingement end having an opening located adjacent the nominal flight plane into which ambient air is drawn for the purpose of deflecting drops in an air deflection direction perpendicular to the nominal flight plane is provided.

Abstract: The invention relates to an apparatus for printing a fluid material by means of a continuous jet printing technique, comprising a reservoir for storing the material, a channel connected with the reservoir, which is provided with at least one outflow opening from which, in use, flows a jet of the material breaking up into drops, and a pressure regulating mechanism for varying the pressure of the material upstream of the outflow opening for the purpose of obtaining drops, the apparatus comprising pressure generating means for passing the material under a predetermined pressure through the channel in the direction of the outflow opening, which pressure generating means are arranged for applying the predetermined pressure to the material in the channel hydraulically and/or pneumatically.

Abstract: A method of printing is provided.

Abstract: A method of printing includes associating a pixel area of a recording medium with a nozzle and a time interval during which a fluid drop ejected from the nozzle can impinge the pixel area of the recording medium; dividing the time interval into a plurality of subintervals; grouping some of the plurality of subintervals into blocks; associating one of two labels with each block, the first label defining a printing drop, the second label defining non-printing drops; associating no drop forming pulse between subintervals of each block having the first label; associating a drop forming pulse between each subinterval of each block having the second label; associating a drop forming pulse between other subintervals, the drop forming pulse being between each pair of consecutive blocks; and causing drops to be ejected from the nozzle based on the associated drop forming pulses.

Abstract: A printhead for an inkjet printer includes an ink reservoir and a plurality of nozzles for ejecting ink from the ink reservoir onto print media, the nozzles being formed in the ink jet printer printhead in a predetermined fashion with bores purposefully shaped and directed to determine the formation and placement of main drops and/or satellite droplets when ink is ejected from the ink reservoir when the printhead is part of an inkjet printer.

Abstract: The method and equipment for detangling individual jets in an ink jet print station utilizes a reservoir containing fluid and a printhead. The printhead has a drop generator, an orifice structure connected to the drop generator for forming numerous jets, a catcher connected to the drop generator; and a charge device secured to the catcher. A fluid supply system is connected between the printhead and the reservoir. A controller and numerous actuators are connected to the drop generator, and adapted to vibrate the drop generator. A fluid pump is connected to the fluid supply line, is operated by the controller, and is adapted to raise the pressure on the drop generator to at least an operating pressure and lower the pressure on the drop generator to a minimal pressure to prevent entanglement of the jets.

Abstract: An ink jet printer is characterised in that a connection part (1) of an umbilical connected to a connection part of a print head of the printer, comprises: first (12, 13, 14, 15, 17, 18, 20–23, 25) and second means (12, 14, 15, 16, 25) for positioning the umbilical electrical terminations (13, 19) and hydraulic terminations (24) mechanically fixed to the connection part (1) of the umbilical; third (12, 28) positioning means mechanically connected to the umbilical, and fourth positioning means (31, 48) mechanically connected to the connection part (3) of the print head, the third (12, 28) positioning means and the fourth positioning means (31, 48) cooperating to position the connection part (1) of the umbilical with respect to the connection part (3) of the print head. A translation movement alone is necessary to connect the umbilical onto the print head.

Abstract: An assembly for depositing material onto a substrate includes a reservoir containing the material. The reservoir also includes a nozzle through which the material is jetted and formed into droplets. The droplets travel through flight paths prior to deposition onto the substrate. The assembly includes a charging ring for inducing an electrical charge to one or more of the droplets and a plurality of deflection plates for controlling the flight paths of the droplets. In addition, the assembly also includes a droplet manipulating device configured to manipulate the droplets at least one of during the flight paths and after deposition of the droplets onto the substrate.

Abstract: Ink jet printing apparatus includes a linear array of jet modules each having an inlet for receiving ink, an outlet for re-circulating the ink, a nozzle for discharging ink in the form of droplets, and a perturbation device for causing a continuous stream of ink droplets to be discharged from the respective nozzle. The apparatus further includes an ink supply system having an inlet manifold, an outlet manifold, and a plurality of connecting passageways connecting the jet modules in parallel between the inlet and outlet manifolds. The connecting passageways connect the inlet of each jet module to the inlet manifold and the outlet of each jet module to the outlet manifold, such as to define a T-connection of each jet module with the inlet and outlet manifolds. Such a construction reduces the mass of each jet module thereby permitting printing at higher frequencies and with smaller ink droplets.

Abstract: The method for controlling ink migration onto a catcher of an ink jet print station from catch condition using a low surface tension ink entails bringing an ink jet print station using low surface tension ink into catch condition with the eyelid sealably engaging the catcher and the catcher flow pan, and using an eyelid actuator to unseal the eyelid forming a gap between the catcher flow pan, the catcher, and the eyelid. The method ends by operating the ink jet print station with the eyelid unsealed to suppress migration of the low surface tension ink onto the catcher during standby mode.

Abstract: Electrocatalyst powders and methods for producing electrocatalyst powders, such as carbon composite electrocatalyst powders. The powders have a well-controlled microstructure and morphology. The method includes forming the particles from an aerosol of precursors by heating the aerosol to a relatively low temperature, such as not greater than about 400° C.

Abstract: A system for delivering material onto a substrate. The system includes a jetting system having a reservoir containing the material and the reservoir includes a nozzle through which the material is expelled from the reservoir. An arcuate section is positioned between the reservoir and the nozzle. The material is configured to travel from the reservoir, through the arcuate section, and through the nozzle. The system also includes a means for applying pressure on the material contained in the reservoir, wherein the material is expelled from the reservoir through application of pressure by the means for applying pressure to thereby create a column of the material from the nozzle. A means for producing pressure modulations is located proximate the nozzle and is configured to substantially regulate formation of droplets from the column of the material. In addition, the system includes a charging ring configured to induce an electrical charge to selective ones of the droplets as they pass through the charging ring.

Abstract: A method, and apparatus for performing the method, are intended to prevent all of the ink discharged from a defective one of multiple nozzles in a continuous inkjet printhead from being used for printing on a print medium. This can be done by periodically heating the defective nozzle at a frequency that is greater than frequencies other nozzles which are not defective are periodically heated, to cause the defective nozzle to only discharge ink droplets that have a smaller volume than ink droplets discharged from the nozzles that are not defective. Then, the smaller volume droplets discharged from the defective nozzle are prevented from reaching a print medium, but the larger volume ink droplets discharged from the nozzles that are not defective are allowed to reach the print medium.

Abstract: An emission device for ejecting a liquid drop is provided. The device includes a body. Portions of the body define an ink delivery channel and other portions of the body define a nozzle bore. The nozzle bore is in fluid communication with the ink delivery channel. An obstruction having an imperforate surface is positioned in the ink delivery channel. The emission device can be operated in a continuous mode and/or a drop on demand mode.

Abstract: An integrated circuit fabricated on a single substrate that includes a data bus and purpose-specific functional units connected to the data bus. The functional units include a halftoner and a printhead interface. A general-purpose processor is connected to the data bus for controlling the functional units, and for coordinating the functional units to print pages. The halftoner may halftone contone color data to a bi-level color layer, and then composit a bi-level black layer over the bi-level color layer.

Abstract: The present invention relates to a method and system for forming a protective cushion to slow down evaporation and prevent clogging in an inactive ink-jet printhead by a) heating ink-jet ink in the at least one ink firing chamber, the ink separating into an organic surfactant phase and an ink colorant phase; and b) forming the protective cushion at the at least one nozzle by allowing the organic surfactant phase to settle as a layer covering the opening of the at least one nozzle in the at least one ink firing chamber.

Abstract: A system and method for supplying replenishment fluid to an ink tank, wherein the ink tank includes a supply line to supply ink to a nozzle and a return line to receive unused ink. The method comprises the steps of periodically using a control system to recalibrate the ink pressure along the supply line to obtain an optimal print quality; and after the ink pressure has been recalibrated, using the control system to automatically adjust a supply rate of the replenishment fluid to the ink tank, wherein the supply rate of the replenishment fluid is adjusted based on the recalibrated ink pressure.

Abstract: The inkjet recording apparatus having ink, where the inertia of ink in a flow passage is M, a viscosity resistance of the ink in the flow passage is R, and a return force of a meniscus is K in a nozzle, when the ink is charged in the flow passage composed of a nozzle and a pressure generating chamber, the physical properties of the ink and the share of the flow passage are set such that, a relationship of 0.2??2/?2?1.0 is satisfied, where ?=?{square root over (K/M)} and ?=R/2M.

Abstract: A catcher device is provided for a continuous ink jet printer of the kind for generating a row of parallel selectively charged drop streams catches charged ink drops. The catcher device combines the attributes of two different materials, specifically a polymer and a metal, and two different processes, to eliminate high cost, material limitations, and geometry constraints associated with prior art catcher constructions.

Abstract: A print head provides for multi-level printing with colorants of different densities without print head replication. A continuous ink jet printer includes a plurality of ink sources; a print head connected to multiple ink sources; and apparatus adapted to selectively transfer ink from each of the connected sources to the print head or to block such transfer. The nozzles selectively create a streams of ink droplets having a plurality of volumes. The apparatus also includes a droplet deflector having a gas source to interact with the stream of ink droplets, thereby separating ink droplets into printing and non-printing paths. The apparatus includes a print heads which can be switched between “light” and “dark” ink sources. This allows multi-level printing, thus achieving higher print quality at the same resolution without incurring the costs associated with additional dedicated print heads.

Abstract: A continuous inkjet method and apparatus including a printhead (2) having an orifice (7) for ejecting a continuous stream of ink droplets of a larger size (21) and a smaller size (23), and a droplet filter (41) for generating a liquid curtain (43) that captures and absorbs the smaller droplets (23) but admits the larger droplets (21). The liquid curtain (43) is orthogonally disposed with respect to the stream of ink droplets (21, 23) and the liquid curtain (43) is the same type of ink as the droplets. The droplet filter (41) in one embodiment includes a source of pressurized ink (51), a nozzle (45) connected to the pressurized ink source (51), and an ink recycler (57) for recapturing and recycling ink. The droplet filter nozzle (45) of one embodiment has a slit-type opening and is directed downwardly in the same direction as the force of gravity.

Abstract: A catcher is provided. The catcher includes a body made from a porous material and having a first, second, and third portion. The first portion of the body defines a delimiting edge. The second portion of the body defines an area recessed from the delimiting edge. The third portion of the body is positioned adjacent to the second portion of the body and extends away from the recessed area such that the second portion of the body and the third portion of the body form an ink accumulation area.

Abstract: A drop-on-demand printer having a row of ink ejection locations (2) for ejecting plural ink droplets, each ejection location (2) having an associated ejection electrode (40) to which a voltage is applied for causing electrostatic ejection of the droplets from the respective ejection location (2); a guard channel (5) disposed between adjacent ejection locations (2), each guard channel (5) having an electrode (50) disposed therein; and control means for applying a voltage to said guard channel electrodes (50), said applied voltage being the average of the voltages applied in operation over a given time to the adjacent ejection location electrodes.

Abstract: A droplet generator for a continuous stream ink jet print head includes an elongate cavity for containing the ink and nozzle orifices in a wall of the cavity for passing ink from the cavity to form jets. The nozzle orifices extend along the length of the cavity. An actuator is disposed on the opposite side of the cavity to the wall for vibrating the ink in the cavity such that each jet breaks up into ink droplets. In operation of the generator, a standing wave is present in the ink in the cavity. The cross-sectional area of the cavity varies along its length in a manner so as to tailor the form of the standing wave in the cavity such that each jet breaks up into the ink droplets at a respective predetermined distance from the wall of the cavity.

Abstract: The use of the lowest all catch voltage for deflecting the charged droplets onto the catcher surface enhances the reliability of the startup sequence for ink jet printers. Going from a state where all of the droplets are hitting in the eyelid seal and catch pan assembly to a state where all of the droplets are deflected and caught on the catcher face will help eliminate the possibility of splatter on the charge plate electrodes and/or the charge short detect level circuitry, ink on top of the eyelid seal, and wicking of ink out of the eyelid.

Abstract: A method, and apparatus for performing the method, are intended to prevent all of the ink discharged from a defective one of multiple nozzles in a continuous inkjet printhead from being used for printing on a print medium. This can be done by periodically heating the defective nozzle at a frequency that is greater than frequencies other nozzles which are not defective are periodically heated, to cause the defective nozzle to only discharge ink droplets that have a smaller volume than ink droplets discharged from the nozzles that are not defective. Then, the smaller volume droplets discharged from the defective nozzle are prevented from reaching a print medium, but the larger volume ink droplets discharged from the nozzles that are not defective are allowed to reach the print medium.

Abstract: A continuous ink jet printhead and method are provided. The printhead includes an ink delivery channel. A plurality of nozzle bores are in fluid communication with the ink delivery channel. An individual obstruction is associated with each nozzle bore. Each individual obstruction is positioned in the ink delivery channel such that each obstruction creates a lateral flow pattern in ink continuously flowing through each of the plurality of nozzle bores as measured from a plane perpendicular to the plurality of nozzle bores.

Abstract: An automatic start-up sequence is provided for an inkjet printer that uses volatile inks for printing. At startup, colorless flush fluid is employed to remove in the drop generator and from the exterior of the orifice plate and from the charge plate. Jets of the flush fluid are established. Stimulation is applied to the jets and charge voltage is applied to the associated charging electrodes to deflect the jets toward the catcher. Concurrent with the jets being so deflected, the jetting fluid is changed from flush fluid for cleaning to the ink for printing. The ability to control the jets of fluid with charge voltage prevents splattering of fluid on the charge leads during the transition from make-up fluid to ink.

Abstract: A droplet generator for a continuous stream inkjet print head has an elongate cavity for containing the ink and nozzle orifices in a wall of the cavity for passing the ink from the cavity to form jets. The nozzle orifices extend along the length of the cavity. An actuator is disposed so as to address the face of the cavity opposite the wall to vibrate the ink in the cavity such that each jet breaks up into ink droplets at substantially the same predetermined distance from the wall. The actuator has a plurality of constituent sub-actuators each capable of independent vibration. The combined coverage of the face of the cavity by the sub-actuators is such that the jet break up can be achieved without resonance of the cavity in its dimension from the wall to the face.

Abstract: A system and method are provided for improving the reliability for shutting down high resolution ink jet printheads for continuous ink jet printers. The shutdown technique fo the present invention solves the problem of ink and/or flush fluid drying in or around orifice holes on higher resolution printheads. This is accomplished with pulse modulation of air pressure used to blow and dry the printhead filters while balancing air flow and negative pressure across the droplet generator and the orifice array.

Abstract: A droplet generator for a continuous stream ink jet print head includes an elongate cavity for containing the ink, nozzle orifices in a wall of the cavity for passing ink from the cavity to form jets. The nozzle orifices extend along the length of the cavity. An actuator is disposed on the opposite side of the cavity to the wall for vibrating the ink in the cavity by itself vibrating relative to the wall. The vibration is such that each jet breaks up into ink droplets at the same predetermined distance from the wall of the cavity. The thickness of the wall through which the nozzle orifices extend is less than 90 &mgr;m. The wall includes a planar member secured to the remainder of the droplet generator so as to form a boundary which extends around the nozzle orifices and within which the planar member is unsupported. The boundary includes first and second boundary lengths which extend along the length of the cavity on either side of the nozzle orifices.

Abstract: A continuous inkjet method and apparatus including a printhead (2) having an orifice (7) for ejecting a continuous stream of ink droplets of a larger size (21) and a smaller size (23), and a droplet filter (41) for generating a liquid curtain (43) that captures and absorbs the smaller droplets (23) but admits the larger droplets (21). The liquid curtain (43) is orthogonally disposed with respect to the stream of ink droplets (21, 23) and the liquid curtain (43) is the same type of ink as the droplets. The droplet filter (41) in one embodiment includes a source of pressurized ink (51), a nozzle (45) connected to the pressurized ink source (51), and an ink recycler (57) for recapturing and recycling ink. The droplet filter nozzle (45) of one embodiment has a slit-type opening and is directed downwardly in the same direction as the force of gravity.

Abstract: Ink particles that start flying toward the printing medium P earlier than or later than the ink particles for the line central area are used as ink particles for the line ends. Accordingly, it is possible to compensate for the affects of electrical charges onto the flying path of the ink particles for the line end portions, reducing the amount of bending at the ends of the printed line such that the bend is not noticeable, thereby improving the quality of printing to satisfy consumer demands.

Abstract: A catcher is provided. The catcher includes a body made from a porous material and having a first, second, and third portion. The first portion of the body defines a delimiting edge. The second portion of the body defines an area recessed from the delimiting edge. The third portion of the body is positioned adjacent to the second portion of the body and extends away from the recessed area such that the second portion of the body and the third portion of the body form an ink accumulation area.

Abstract: In a first aspect, in a continuous stream ink jet printing system generating a plurality of streams of ink droplets, a chosen number of droplets of each stream is less than all of the droplets of the stream. A controller of the printing system is arranged to consider for printing from among a number of the droplets of each stream greater than the chosen number with the proviso that the resultant selection made observes this constraint. In second and third aspects, the controller of the printing system is arranged to create a set of droplet print positions ideal for representing an image to be printed, which set is permitted to include print positions offset from print positions of a nominal matrix, at speeds of operation less than the predetermined speed. The controller compares the positions at which droplets are deposited at the lower speed with the set of ideal positions. The controller decides which droplets to print in dependence on the comparison.

Abstract: A screen mesh ink drop catcher assembly, which is adapted to catch non-printed ink drops while not catching printed ink drops, includes a housing having a fluid return channel, and a screen extending from the housing operable to collect unwanted ink drops. The housing of the ink drop catcher assembly may include at least one surface, at least a portion of which is grooved and operatively associated with the screen thereby improving ink drop flow from the screen to the fluid return channel. The housing of the ink drop catcher assembly may include a screen support with the screen being at least partially positioned about the screen support. The screen support of the ink drop catcher assembly may include at least one surface, at least a portion of which is grooved and operatively associated with the screen thereby improving ink drop flow from the screen to the fluid return channel.