Patent Description:
Inkjet printing heads require periodic cleaning of printing nozzles to remove buildup (solid sediments and debris) on the nozzles, remove air bubbles, remove pooled liquids and otherwise maintain printing quality. Cleaning the printing head is an inherent part of the inkjet printing process, for example in some industrial settings the printing head is cleaned as often as every two minutes. The cleaning frequency depends on the specific application for which the printing head is being used. Typically, cleaning can also be done by removing the print head to one side of the printer for easy access and cleaning the head either manually or using a wiper. These methods are time consuming and inefficient.

Typically, removing buildup without contact to the orifice (nozzle) plate can be done using vacuum where a vacuum 'head' is moved across the orifice plate. The vacuum head can be maneuvered sufficiently close to allow the vacuum induced suction to remove ink and residues from the orifice plate (interchangeable with nozzle plate). Because the vacuum head does not contact the orifice plate, efficiency of the orifice plate cleaning is low. Similarly, service stations (referring to a dedicated zone within the printer housing), have an elastomeric wiper that wipes the print head surface to remove ink residue, as well as other debris that has collected on the face of the orifice plate. Other service stations include auxiliary wiping members to clean areas of the print head and protective bracket adjacent to the ink ejecting nozzles.

Moreover, when the ink contains volatile components, the ink at a nozzle may lose those components, resulting, under certain circumstances, in the remaining ingredients of the ink forming a semi-solid skin at the nozzle. The semi-solid skin, or buildup of solid sediments, can interfere with the jetting of ink from the nozzles, reducing the print quality or even disabling jetting of ink from one or more nozzles. Likewise, using UV-curable ink may also cause build-up that may eventually block the nozzles, reducing print quality.

<CIT> discloses devices, systems and methods for contactless maintenance of inkjet print heads. In particular, the document relates to devices, systems and methods that allow for removing of purged ink from an inkjet print head without contacting the aperture plate by drawing vacuum, with liquids or other mechanical means, such as wipes.

<CIT> discloses a head cleaning apparatus for an inkjet printer which allows preventing damages to the hydrophobic coating layer on a surface of the print head by washing the print head in a non-contact manner. The apparatus comprises a head driving part for elevating a head, a washing tub, and a suction nozzle. The washing tub stores washing liquid to dip a nozzle outlet of the head, which is moved downward by the head driving part, into the washing liquid. The suction nozzle removes the washing liquid in the nozzle outlet of the head floated after being dipped into the washing liquid of the washing tub with predetermined pressure.

<CIT> discloses an inkjet recording apparatus configured to perform recording by discharging ink from a plurality of discharge ports disposed on a recording head. The apparatus includes a cap adapted to cover the plurality of discharge ports disposed on the recording head, a recessed portion defined on a bottom face inside the cap, a suction hole facilitating introduction of a negative pressure to the recessed portion, an atmosphere communication hole located outside a range of the recessed portion and communicating with atmosphere, an ink absorber mounted inside the cap to cover the recessed portion, and a suction pump connected to the suction hole and configured to generate a negative pressure. When the plurality of discharge ports is covered with the cap, a projection image obtained when the plurality of discharge ports is projected onto the bottom face exists within the range of the recessed portion.

There is therefore a need for a system for cleaning orifice plates, with increased efficiency over conventional techniques, preventing sediment buildup, removing pooled liquids while simultaneously, not damaging the orifice plate itself.

Disclosed, in various embodiments, are systems and methods for removing purged ink and other debris from inkjet print head(s) and their surroundings, without contacting the nozzle plate of the print head(s) with mechanical means.

In an embodiment provided herein is a contactless cleaning system for at least one inkjet print head comprising: a support bracket; a platform having a proximal end and a distal end, an apical surface and a basal surface, a portion of the basal surface coupled to the support bracket; a catch basin defined in the apical surface of the platform; for each inkjet print head, an elongated bath defining a longitudinal axis, the elongated bath having length that is equal to or longer than the length of a nozzle plate of each inkjet print head; for each inkjet print head, a suction duct disposed distally to the elongated bath, the suction duct having a tip protruding apically from the catch basin with an elongated slit defining a longitudinal axis transverse to the longitudinal axis of the elongated bath; for each inkjet print head, an elongated washing port in communication with a pressurized liquid source and a vacuum source; and a vacuum blade having a length sized and configured to span a cross section of an area that needs cleaning due to wash liquid residue and other printing debris or condensation, the vacuum blade disposed distally to the washing port, being in communication with a vacuum source.

In another embodiment, provided herein is an inkjet print head comprising a nozzle plate with a grid of apertures along a longitudinal axis having a nozzle plate width transverse to the longitudinal axis of the nozzle plate; a guard plate with an elongated quadrilateral window sized and configured to expose the nozzle plate, the guard plate having guard plate width; and dispensing means configured to dispense an ink, being in fluid communication with the ink reservoir, wherein the dispensing means is configured to dispense ink droplets through the nozzle plate.

In another embodiment, provided herein is a method implementable in the above-described system for contactless cleaning of at least one inkjet print head as defined in the foregoing, the method comprising: at a first predetermined event, actuating the vacuum source; advancing the at least one print head along the longitudinal axis of the apertures grid in the nozzle plate in a proximal distance above the vacuum blade thereby removing excess ink from the nozzle plates area that needs cleaning; following clearing of a distal end of the guard plate, purging the at least one print head into at least one of the elongated bath and catch basin; and advancing the at least one print head along the longitudinal axis of the apertures grid in the nozzle plate in distal direction above the suction duct, thereby removing purged ink and cleaning the plurality of nozzle plates and guard plates.

These and other features of the methods, and systems for removing purged ink and other debris from inkjet print head without contacting the nozzle plate with mechanical means, will become apparent from the following detailed description when read in conjunction with the figures and examples, which are exemplary, not limiting.

For a better understanding of the cleaning systems and methods disclosed for removing purged ink and other debris from inkjet print head without contacting the nozzle plate with mechanical means, with regard to the embodiments thereof, reference is made to the accompanying examples and figures, in which:.

Provided herein are embodiments of systems and methods for removing purged ink and other debris from inkjet print head without contacting the nozzle plate with mechanical means.

A more complete understanding of the components, processes, assemblies, and devices disclosed herein can be obtained by reference to the accompanying drawings. These figures (also referred to herein as "FIG. ") are merely schematic representations (e.g., illustrations) based on convenience and the ease of demonstrating the present disclosure, and are, therefore, not intended to indicate relative size and dimensions of the devices or components thereof and/or to define or limit the scope of the exemplary embodiments. Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of the embodiments selected for illustration in the drawings, and are not intended to define or limit the scope of the disclosure. In the drawings and the following description below, it is to be understood that like numeric designations refer to components of like function.

Turning to <FIG> illustrating a contactless inkjet print head cleaning station <NUM> comprising: support bracket <NUM> with platform <NUM> (additional embodiments are shown in <FIG>) having proximal end <NUM> and distal end <NUM>, apical surface <NUM> and a basal surface <NUM>, whereby portion of basal surface <NUM> is operably coupled to support bracket <NUM>, for example, using coupling/leveling tabs <NUM>q enabling calibration/adjustment of the plane of suction nozzles (<NUM> X <NUM>, <NUM> X <NUM>, <NUM>) to the exact distance from print head <NUM> nozzle plate(s) <NUM> Also shown in <FIG>, <FIG>, is catch basin <NUM> defined in apical surface <NUM> of platform <NUM>. Each of the plurality of inkjet print heads (see e.g., <FIG>, <FIG>) there is elongated bath <NUM>i defining longitudinal axis X<NUM>, elongated bath <NUM>i having length l<NUM> that is equal to or longer than the length of nozzle plate <NUM>, l<NUM> (interchangeable with orifice plate see e.g., FIG. 4A) of each of the inkjet print heads <NUM> (see e.g., <FIG>). For each of the plurality of inkjet print heads <NUM>, suction duct is disposed distally to the elongated bath, suction duct having tip <NUM>p protruding apically from catch basin <NUM> with an elongated slit defining a longitudinal axis X<NUM> transverse to the longitudinal axis X<NUM> of elongated bath 106i. In addition, for each of the plurality of inkjet print heads <NUM>, elongated washing port <NUM>k in communication with a pressurized liquid source (see e.g., <NUM>, <FIG>) In certain embodiments, washing port <NUM>k further comprises vacuum conduit <NUM> (see e.g., <FIG>), sized and configured to contain the washing to the designated area and removes any resulting excesses. Also illustrated in <FIG>, and <FIG> is vacuum blade <NUM> having length l<NUM> spanning at least one side of catch basin <NUM>, vacuum blade <NUM> disposed distally to washing port <NUM>k, being in communication with vacuum source <NUM>, see e.g., <FIG>). Moreover, in another embodiment, vacuum blade <NUM> is configured to span at least the nozzle plate and up to the width of protective plate <NUM> of all printing heads <NUM>, including between and around print heads <NUM>. Likewise, vacuum blade <NUM> can be extended anywhere the print head <NUM> group are desired to wipe from debris due to printing condensate, spray, pooling and the like.

For example, as seen in <FIG>, catch basin <NUM> can accommodate the full length l<NUM> of vacuum blade <NUM> and can be configured to be drained to a waste container (see e.g., <NUM> <FIG>). As seen in <FIG>, and <FIG> vacuum blade can have slits <NUM> configured to provide fluid communication to vacuumed fluids across a single print head, between adjacent print heads and at the periphery - wherever it is desired to clean liquids such as pooled liquids, debris and ink.

Also shown, in <FIG>, is sensor <NUM> located on apical surface <NUM>. Sensor <NUM> can be configured to sense the location of proximal end <NUM> of print head <NUM> and/or distal end <NUM> of print head <NUM> and/or print head <NUM> support bracket <NUM> or designated edge (see e.g., <FIG>), or designated edge thereof, to actuate or terminate processes for cleaning or steps in the methods disclosed. Additional sensor <NUM>' (not shown) can be positioned on platform <NUM>, opposite sensor <NUM>, and can each be functionally coupled to a different print head <NUM>, platform support bracket <NUM> and/or designated edge thereof, and be configured to actuate the various unit operations. Furthermore, additional sensors can be added for safety or redundancy. In another embodiment, some or all of the sensors can be replaced by, or used in parallel with axis' (e.g., X<NUM>) encoders for location verification and validation.

Nozzle (orifice) plate <NUM>, can be located on the printing side (lower, or basal surface) of printing head <NUM> (see also <FIG>), providing access for the nozzles to print. Purged ink <NUM> from each nozzle can exit the orifice grid. Purging, in other words, forcing ink out of the nozzles by pressure, may, under certain circumstances, cause ink drops <NUM> to be left hanging by adherence to the nozzle plate. Similar circumstances (in other words, ink drops <NUM> are left hanging by adherence to the nozzle plate) can be caused by a tickling process, referring to the formation of a pulse waveform configured to fill the orifice(s) without actually ejecting the ink drops, yet, due to surface phenomena where ink partially blocking the orifice(s), and surface tension, some ink will be expelled nonetheless.

The adhered can then be vacuumed by suction nozzle <NUM>p; and may (or may not) be recycled back into the ink recycling system. Purging (or tickling) is done for example, to refresh the ink in the print head ducts and nozzles. During at least one of: periodic cleaning after purging, and tickling, the orifice surface can be cleaned to remove buildup, purged liquid, and enable proper jetting of the printing ink from the nozzles (via the orifices). In order to preserve the smoothness and high interfacial tension between the printing side and the jetted ink (non-wetting, or drop forming characteristic) and the orifice surface, cleaning must be affected.

The term "fluid communication" or "liquid communication" refers to any area, a structure, or communication that allows for fluid communication between at least two fluid retaining regions, for example, a tube, duct, conduit or the like connecting two regions. One or more fluid communication can be configured or adapted to provide for example, vacuum driven flow, electrokinetic driven flow, control the rate and timing of fluid flow by varying the dimensions of the fluid communication passageway, rate of circulation or a combination comprising one or more of the foregoing. Alternatively, and in another embodiment, the term "in communication" can also refer to gaseous communication, i.e. that gas may be transferred from one volume to another volume since these volumes are in communication. This term does not exclude the presence of a gas shutter or valve between the volumes that may be used to interrupt the gas communication between the volumes.

Additional embodiments of elongated bath 106i are illustrated in <FIG>, where elongated bath 106i has a proximal end <NUM> and distal end <NUM>, with peripheral wall <NUM> protruding above catch basin <NUM> (see e.g., <FIG>), wherein wall <NUM> defining lip <NUM> with a channel therein (not shown), configured to accommodate and engage a gasket (e.g., O-ring) sized and configured to abut guard plate <NUM> of print head <NUM>, thus sealing elongated bath. Also shown is internal cavity <NUM> and elongated bath floor <NUM>. Washing ports <NUM>, <NUM> can, for example be the same as wash port <NUM>, including vacuum pipe <NUM> (see e.g., <FIG>); and have the same fluid communication to recycling modules as illustrated in <FIG> and <FIG>, or to waste tank <NUM>, as illustrated in <FIG>.

Accordingly and in an embodiment, as illustrated in <FIG>, in arriving to the cleaning module, print head can be maneuvered and either lowered to abut gasket <NUM>, or cleaning stage <NUM> (see e.g., <FIG>) can be maneuvered such that gasket <NUM> abuts guard plate <NUM>, creating a sealed tub. Once sealed, using pressurized washing liquid <NUM>, guard plate <NUM> and nozzle plate <NUM> can be sprayed using washing ports <NUM>, <NUM> (see e.g., <FIG>). Additionally or alternatively, elongated bath 106i can be filled (see e.g., <FIG>), such that washing liquid <NUM> is forced through nozzle plate <NUM> into print head <NUM>, then expelled again once elongated bath <NUM>i is drained through drain <NUM>j.

For example, the area desired to be washed, such as at-least the nozzle area, can be enclosed fully and potentially hermetically in the tub. In this embodiment the tub serves as a capping station (see e.g., <FIG>, <FIG>) and/or purge bath (See e.g., <FIG>) as well as wash port <NUM>k, and may allow other functions such as vacuum purge (see e.g., <FIG>), whereby the force for the nozzle purge comes from a controlled vacuum source <NUM> (see e.g., <FIG>) in the wash port, and/or inverse nozzle purge (see e.g., <FIG>), whereby washing fluid <NUM> is controllably forced through print head <NUM> nozzle plate <NUM> into print head <NUM>, for example for clearing blockages. Other various combinations of the methods described including the controlled draining of the fluids and gasses from the wash port during or after said methods are possible as illustrated in <FIG>.

In another embodiment, as illustrated in <FIG> elongated bath <NUM>i opening may be covered by cover <NUM> closed by an actuating mechanism (not shown), which, when closed, does not allow spray washing liquid <NUM> to exit the elongated bath 106i. Cover <NUM> can further add protection, contained self-washing functionality as well as means for system diagnosis without the need for external cover at a specified distance such as with print head <NUM> when washing.

Turning now to <FIG>, illustrating washing stage <NUM>, which can be a single module as illustrated in <FIG>, a part of a plurality of static washing modules as illustrated in <FIG>, or as part of a maneuverable (in other words, motorized and mobile) stage on X and/or Y and/or Z axis to serve a plurality of print heads (see e.g., <FIG>).

An embodiment of inkjet print head <NUM> having proximal end <NUM> and distal end <NUM>, is illustrated in <FIG> and can comprise: nozzle plate <NUM> (see e.g., <FIG>) with a grid of apertures along a longitudinal axis X<NUM> having a nozzle plate width W<NUM> transverse to longitudinal axis X<NUM> of nozzle (or aperture) plate <NUM>. Print heads <NUM> can also have guard plate <NUM> with elongated quadrilateral window <NUM> sized and configured to expose nozzle plate <NUM>, the guard plate having guard plate width W<NUM> and dispensing means configured to dispense ink <NUM> (see e.g., <FIG>), being in fluid communication with the ink reservoir (not shown), wherein the dispensing means (e.g., pump, piezo-electric pulse, membrane and the like) is configured to dispense ink <NUM> droplets through nozzle plate <NUM>. The dispensing means can be, for example an apparatus for dispensing small quantities of liquid including micro-valves, piezoelectric dispensers, continuous-jet print-heads, boiling (bubble-jet) dispensers, and other means affecting the temperature and properties of the fluid flowing through the dispenser.

Turning now to <FIG>, where each of elongated baths <NUM>i further comprise drain <NUM>j in fluid communication with first receptacle <NUM> (see e.g., <FIG>, <FIG>). As illustrated, elongated bath <NUM>i is slanted toward drain <NUM>j, with elongated bath width W<NUM> that is equal to or wider than width W<NUM> of nozzle plate <NUM>. Similarly and as illustrated in <FIG> and <FIG>, each suction duct having tip <NUM>p protruding apically from catch basin <NUM> can be in fluid communication with vacuum source <NUM> (see e.g., <FIG>), through dedicated vessel, <NUM> (see e.g., <FIG>, <FIG>), configured to capture and collect ink <NUM> adsorbed onto at least one of nozzle plate <NUM> and guard plate <NUM> (see e.g., <FIG>) of print head <NUM>. Tip <NUM>p width W<NUM> of elongated slit in tip <NUM>p of the suction duct sized to be equal to or wider than width W<NUM> of the nozzle plate <NUM>. However, in certain embodiments, width W<NUM> of elongated slit in tip <NUM>p of the suction duct sized to be equal to width W<NUM> of the nozzle plate <NUM> exactly. As illustrated in <FIG>, Tip <NUM>p of the suction duct can have other shapes and sizes and may not necessarily be elongated, yet can still be sized to be equal to or wider than width W<NUM> of the nozzle plate <NUM>.

Returning now to <FIG>, SA, 11B and 19A and 19B, elongated (in certain embodiment, or other aperture shapes) washing port protrudes apically from catch basin <NUM> floor, protrusion <NUM>k (see e.g., <FIG>, <FIG>) defining an elongated opening with axis X<NUM> transverse (or parallel, see e.g., <FIG>) to longitudinal axis of the elongated bath X<NUM> and width W<NUM> that is equal to or larger than width W<NUM> of the print head's guard plate (see e.g., <FIG>). In addition, elongated washing port further comprises a liquid ejection nozzle <NUM> (see e.g., <FIG>), sized and configured to eject a fan-shaped washing liquid <NUM> at an angle θ of between about <NUM>° and about <NUM> ° (see e.g., <FIG>, <FIG>), for example, between <NUM>° and <NUM>°. Furthermore, width W<NUM> of washing liquid fan <NUM> is configured and sized to be equal to or larger than nozzle plate <NUM> width W<NUM> yet smaller than width W<NUM> of guard plate <NUM> of print head <NUM>, thus being configured to wash the whole basal surface of print head <NUM>. The washing liquid is pressurized for example, to at least about one (<NUM>) atmosphere, or between about <NUM> Atm. and about <NUM> Atm. , or between about <NUM> Atm. and <NUM> Atm. In other embodiment, and as illustrated in <FIG>, the fan-shaped spray may be configured to cover the whole underside of print head <NUM> and even overlap when two (or more) washing ports <NUM>, <NUM> are used, with the fan-shaped spray being in parallel with the longitudinal axis X<NUM> of nozzle plate <NUM>. Although the disclosure refers to fan-shaped spray, depending on the desired use, other spray shapes are contemplated, for example full cone spray, hollow cone spray, full jet blast, hollow circular spray, flat fan and their combination. For example, in the embodiment illustrated in <FIG>, it is contemplated that the spray shape of cleaning liquid <NUM> used in wash ports <NUM>, <NUM>, can be the same or different, for example wash port <NUM> will spray a hollow cone, while washing port <NUM> will spray a flat fan. Moreover, the washing fluid expelled from each washing port <NUM>, <NUM> can be different or the same.

<FIG> and <FIG> illustrate an embodiment of the washing module directed to a single (<FIG>) or a plurality (<FIG>) print head(s), without recycling option. As illustrated, air/liquid separators <NUM> (illustrated in fluid communication, in other words, hydraulically coupled with and to vacuum blade <NUM>), and <NUM>, can be the same or discrete units and the determination on keeping the separators the same or different can be based on the printed materials (inks) and the needs of the user. As illustrated, vacuum blade <NUM> can be used to dry or otherwise wipe liquids and other debris from the area sought to be cleaned (see e.g., <FIG>) following purging, either to catch basin <NUM> or to elongated bath 106i as illustrated in <FIG>, <FIG>. Similarly, catch basin <NUM>, suction duct <NUM>p, and wash port <NUM>k can be in fluid communication with air/liquid separator <NUM>, while wash port <NUM>, being in fluid communication with wash liquid <NUM> delivery system <NUM>. As illustrated in <FIG>, the architecture can be duplicated for two or more print heads both in terms of stage <NUM> (see e.g., <FIG>, <FIG>), as well as separators <NUM>, <NUM>', while air/liquid separators <NUM> being in fluid communication with vacuum blade <NUM> can be single reservoir, or as illustrated in <FIG>, and <FIG>, each slit <NUM> in vacuum blade <NUM>, may be directed to different reservoirs (separators) e.g., <NUM>', <NUM>" and the like.

Conversely, <FIG> and <FIG>, illustrate an embodiment of the washing module directed to a single (<FIG>) or a plurality (<FIG>) print head(s), with recycling option. As illustrated, air/liquid separator <NUM> in fluid communication with vacuum blade <NUM>, while wash port <NUM>k elongated bath 106i, are in fluid communication with dedicated separator <NUM> with suction duct <NUM>p in fluid communication with dedicated separator <NUM>. Each separator can be in further communication with a vacuum source <NUM> and a compressor <NUM> and allowing the collected liquid to further undergo recycling. Similar to the non-recycling embodiments, vacuum blade <NUM> can be used to dry or otherwise wipe liquids and other debris from the area sought to be cleaned (see e.g., <FIG>) following purging, either to catch basin <NUM> or to elongated bath <NUM>i as illustrated in <FIG>, <FIG>. Similarly, catch basin <NUM>, suction duct <NUM>p, can be adapted to collect purged ink(s) and be in fluid communication with air/liquid separator <NUM>, where collected inks can be recycled and returned to print heads <NUM>. As illustrated in <FIG>, the architecture can be duplicated for two or more print heads both in terms of stage <NUM> (see e.g., <FIG>, <FIG>). Under certain circumstances, depending on the ink used in each print head, washing liquid <NUM> used to wash nozzle plate <NUM> and guard plate <NUM> used for one print head <NUM> (e.g., PHi), will be different than washing liquid <NUM>' used for another print head <NUM> (e.g., PH<NUM>), or be changed sequentially on the same print head. Moreover, in the embodiment illustrated in <FIG>, it is contemplated that the washing liquid <NUM> expelled from wash port <NUM> will be the same or different than washing liquid <NUM>' expelled from washing port <NUM>. Selection of washing liquid <NUM>, can be dependent on, for example, the type of ink used, the desired cleaning, the stage of cleaning, whether debris is present rather than pooled ink or purged ink, whether there are blockages in the nozzle plate, their combination and the like. It stands to reason, that recycling and reclamation of different washing liquids, each associated with a different print head can also be done using dedicated air/liquid separators <NUM>, <NUM>' (see e.g., <FIG>).

In other words, the methods disclosed herein provide for utilizing a sequence of different washing solutions through the same washing port <NUM>k on the same print head <NUM> to clean nozzle plate <NUM> and its surrounding (in other words, between adjacent print heads <NUM> e.g. PHi, PH<NUM>, and PH<NUM> in <FIG>, and around the whole group of print heads), can be carried out for circumstances where the material and/or the residue form the first cleaning solution cannot be removed by the single solution washing step. Consequently, a sequence of solutions can be used in such a way that the second (or third or more) solution is formulated and configured to remove the residue, ink or debris left-over form the previous step, and if necessary additional washing steps can be applied. In another embodiment, the last step comprises a fast drying solution such as, for example, isopropyl alcohol, acetone (if possible) or deionized (DI) water, each utilized so long as it is a compatible with printer head <NUM> nozzle's plate <NUM> material.

In an embodiment, the methods described herein are implemented using the systems described. Accordingly, provided herein is a method for contactless cleaning of a plurality of inkjet print heads <NUM>, implementable in a system comprising: support bracket <NUM>; platform <NUM> having a proximal end <NUM> and distal end <NUM>, apical surface <NUM> and basal surface <NUM>, a portion of which is coupled to support bracket <NUM>. Platform <NUM> also comprises catch basin <NUM> defined in apical surface <NUM> of platform <NUM>. For each of plurality of inkjet print heads <NUM>, elongated bath <NUM>i exists, defining longitudinal axis X<NUM>, elongated bath <NUM>i having length l<NUM> that is sized and configured to be equal to or longer than length l<NUM> of nozzle plate <NUM> of each of inkjet print head <NUM>. In addition, for each of plurality of inkjet print heads <NUM>, a suction duct is disposed distally to elongated bath 106i, suction duct having tip <NUM>p protruding apically to catch basin <NUM> with an elongated slit defining longitudinal axis X<NUM> transverse to longitudinal axis X<NUM> of elongated bath 106i. Also, for each of plurality of inkjet print heads <NUM>, there is an elongated washing port <NUM>k in communication with a pressurized liquid source and a vacuum source <NUM> configured to contain the washing spray. Although shown as an elongated opening with a major axis X<NUM> transverse to longitudinal axis X<NUM>, other aperture shapes are contemplated.

Further, platform <NUM> comprises vacuum blade <NUM> having length l<NUM> spanning at least catch basin <NUM> side, vacuum blade <NUM> disposed distally to washing port <NUM>k, being in communication with a vacuum source, wherein each inkjet print head <NUM> comprises: nozzle plate <NUM> with a grid of apertures along longitudinal axis X<NUM> having nozzle plate width W<NUM> transverse to longitudinal axis X<NUM> of nozzle plate <NUM> with guard plate <NUM> with elongated quadrilateral window <NUM> sized and configured to expose nozzle plate <NUM>, guard plate505 having guard plate width Wsos; and a dispensing means configured to dispense ink <NUM>, being in fluid communication with ink reservoir (not shown), wherein the dispensing means is configured to dispense ink <NUM> droplets through nozzle plate <NUM>, the method comprising: at a first predetermined event (e.g., purging), depending on the type of printing, the ink and the printing conditions, (optionally automatically) actuating vacuum source <NUM> (see e.g., <FIG>). In an embodiment, using the first predetermined time event to reduce the number of times and the time length for purging processes.

A predetermined event can be, for example a set time lapse period, number of prints generated, time length of a single print process, amount of ink used in over one or several printing process(es), residue build-up detected by user or sensors (e.g., cameras configured to inspect the orifice plate(s)). For example, at designated times during a print job, such as when alternating printing between print heads and/or printing materials, before starting to print, upon detecting deterioration of printing by sensors (camera) on a print output, before, after, and/or as part of a series of other actions such as print head docking, print head capping, tickling, replacement of print head and/or ink or other fluid circulated through the print head such as cleaning solution.

At the predetermined event simultaneously advancing all the plurality of print head <NUM> along their longitudinal axis X<NUM> of apertures grid in nozzle plate <NUM> (see e.g., <FIG>) in a proximal direction (in other words, from distal end <NUM> toward proximal end <NUM>) above vacuum blade <NUM> thereby removing excess ink and other loose debris and/or pooled liquids from each nozzle plate <NUM>, as well as guard plate <NUM>, as well as other areas between and around print head(s) <NUM>. Following clearing of distal end <NUM> of guard plate <NUM> (detected in an embodiment by sensor <NUM>, purging print heads <NUM> into at least one of elongated bath <NUM>i and catch basin <NUM>; and advancing plurality of print head <NUM> along longitudinal axis X<NUM> of apertures grid in nozzle plate <NUM> in distal direction above the suction duct <NUM>p thereby removing purged ink and in a contactless manner, cleaning plurality of nozzle plates <NUM> and guard plates <NUM>.

In an embodiment, maintenance procedures utilizing the contactless cleaners described herein, can typically include purging ink through apertures of the print head, which can also be referred to as "burping". In order to purge ink from print head <NUM> of e.g., <FIG>, and <FIG> a purge pressure may be applied to ink in an on-board reservoir (not shown) using a pressure source (e.g., air pump, or compressed air tank) through an opening, or vent, operably coupled to print head <NUM>. In an embodiment, the term "purge pressure" refers to the pressure of air (or other gas) applied to ink <NUM> in an on-board reservoir that is configured to urge ink from the reservoir through the inkjet ejectors and be released from the apertures in nozzle plate <NUM>.

The methods for contactless cleaning of inkjet print heads can further comprise at a second predetermined event (for example, between about <NUM> hours and <NUM> hours, or upon noticing a precipitous decline in print quality, both which can be determined automatically), before the step of purging, advancing the plurality of print heads <NUM> along the longitudinal axis X<NUM> of the apertures grid in the nozzle plate <NUM> above the wash port <NUM>k; and spraying guard plate <NUM> and nozzle plate <NUM> with cleaning liquid <NUM> (see e.g., <FIG>, <FIG>, <FIG>), wherein elongated, or differently shaped (see e.g., <FIG>)washing port <NUM>k protrudes apically from catch basin <NUM>, the protrusion defining an elongated opening with axis X<NUM> transverse to longitudinal axis X<NUM> of elongated bath <NUM>i and width W<NUM> that is equal to or larger than width W<NUM> of the print head's <NUM> nozzle plate <NUM>, and wherein elongated washing port <NUM>k further comprises a liquid ejection nozzle <NUM>, sized and configured to eject a fan-shaped washing liquid <NUM> at an angle θ of between about <NUM>° and about <NUM> °. Washing port <NUM>k is further coupled and in fluid communication with a vacuum source (see e.g., <NUM> FIG. 's 2B and <NUM>) configured to vacuum excess washing liquid, used to contain the washing port's spray of liquid washing fluid <NUM>.

In certain embodiments, ejection of ink from nozzle plate <NUM> can employ dispensing means such as a piezoelectric element, which repeatedly applies and reduces pressure to eject ink, and can cause minute bubbles to form due to cavitation, or through turbulence once purged.

The ink and other components (e.g., build up residue, solid sediment and the like) suctioned off using the system described herein can be transported to a waste reclamation system (see e.g., <FIG>, <FIG>), modified and returned to print head <NUM> ink reservoir. Similarly, washing liquid <NUM> sucked from suction duct <NUM>k can be recycled into usable wash liquid. The recycling sub-system may comprise various components, for example filters, valves, adsorbing elements, manifolds, addition of various solvents and additives and the like. Generally, the term "recycling" refers to a sub-system used to reprocess the purged content such as, for example, ink of suction duct <NUM>p (see e.g., <FIG>, and <FIG>) to a condition where it can be used effectively in the printing operation carried out. As an example, washing liquid <NUM> may be recycled in a separate system to the ink recycling system, see e.g., <FIG> and <FIG>.

The terms "first," "second," and the like, when used herein do not denote any order, quantity, or importance, but rather are used to denote one element from another. The terms "a", "an" and "the" herein do not denote a limitation of quantity, and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The suffix "(s)" as used herein is intended to include both the singular and the plural of the term that it modifies, thereby including one or more of that term (e.g., the channel(s) includes one or more channel). Reference throughout the specification to "one embodiment", "another embodiment", "an embodiment", and so forth, means that a particular element (e.g., feature, structure, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments.

In addition, for the purposes of the present disclosure, directional or positional terms such as "top", "apical", "basal", "proximal", "distal", "bottom", "upper," "lower," "side," "front," "frontal," "forward," "rear," "rearward," "back," "trailing," "above," "below," "left," "right," "radial," "vertical," "upward," "downward," "outer," "inner," "exterior," "interior," "intermediate," etc., are merely used for convenience in describing the various embodiments of the present disclosure.

The term "coupled", including its various forms such as "operably coupled", "coupling" or "coupleable", refers to and comprises any direct or indirect, structural coupling, connection or attachment, or adaptation or capability for such a direct or indirect structural or operational coupling, connection or attachment, including integrally formed components and components which are coupled via or through another component or by the forming process (e.g., an electromagnetic field). Indirect coupling may involve coupling through an intermediary member or adhesive, or abutting and otherwise resting against, whether frictionally (e.g., against a wall) or by separate means without any physical connection.

The contactless cleaner used in the systems and methods for removing purged ink without mechanical or fluid contact described herein can further be in electric communication with at least one sensor (e.g., pressure sensor) and a processor, configured to maintain a predetermined pressure or a programmable pressure profile throughout the cleaning process and the recycling process and additionally or alternatively, diagnose problems in the system. For example, the system can comprise sensor array at various locations, with temperature and/or pressure and/or viscosity data feedback to the processor, which, in turn, will control the various valves, affecting gas flow fluid/spray pressure, and the like.

Other than proximity sensor <NUM>, other sensors can be incorporated into the system, for example, image (visual) sensors (e.g., CMOS, CCD, for example to monitor ink color, drop shape/volume and nozzle status), microflow (or flow) sensors (e.g., EM based, Resonant feedback based, Pitot-based) viscosity sensors, timing sensors, conductivity sensors, or an array comprising one or more of the foregoing. The sensors, including the temperature sensors and/or humidity sensors can provide data to a processor comprising memory having thereon computer-readable media with a set of executable instruction enabling the processor, being in electronic communication with a driver or drivers, as well as the print heads, to automatically (in other words, without user intervention) change the position of the print heads, relative to the cleaning platform. The processor may also determine whether purging ink is recycled back to an ink reservoir in fluid communication with the print head or diverted to waste vessel.

The processor can further have a memory module with computer readable media stored thereon, comprising a set of instructions thereon configured to carry out the cleaning and/or recycling methods described herein, provide temperature/pressure controls, timing, movement, vacuum flow, spray pressure profile (t, P, fan angles) and form, continuous or pulsed spray and the like.

The term "comprising" and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, "including", "having" and their derivatives.

All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. Furthermore, the terms "first," "second," and the like, herein do not denote any order, quantity, or importance, but rather are used to denote one element from another.

Likewise, the term "about" means that amounts, ranges, sizes, formulations, parameters, and other quantities and characteristics are not and do not need be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. In general, an amount, ranges, size, formulation, parameter or other quantity or characteristic is "about" or "approximate" whether or not expressly stated to be such and is intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, "about" can include a range of +/-<NUM>% or <NUM>%, or <NUM>% of a given value.

Claim 1:
A contactless cleaning system for at least one inkjet print head (<NUM>) comprising:
a. a support bracket (<NUM>);
b. a platform (<NUM>) having a proximal end (<NUM>) and a distal end (<NUM>), an apical surface (<NUM>) and a basal surface (<NUM>), a portion of the basal surface (<NUM>) coupled to the support bracket (<NUM>);
c. a catch basin (<NUM>) defined in the apical surface (<NUM>) of the platform (<NUM>);
d. for each inkjet print head (<NUM>), an elongated bath (<NUM>i) defining a longitudinal axis (X<NUM>), the elongated bath (<NUM>i) having a length (l<NUM>) that is equal to or longer than the length (l<NUM>) of a nozzle plate (<NUM>) of each inkjet print head (<NUM>);
e. for each inkjet print head (<NUM>), a suction duct disposed distally to the elongated bath (<NUM>i), the suction duct having a tip (<NUM>p) protruding apically from the catch basin (<NUM>) with an elongated slit defining a longitudinal axis (X<NUM>) transverse to the longitudinal axis (106i) of the elongated bath (106i);
f. for each inkjet print head (<NUM>), an elongated washing port (<NUM>k) in communication with a pressurized liquid source and a vacuum source (<NUM>); and
g. a vacuum blade (<NUM>) having a length (l<NUM>) spanning at least the area sought to be cleaned, the vacuum blade (<NUM>) disposed distally to the washing port (<NUM>k), being in communication with the vacuum source (<NUM>).