MXPA97008571A

MXPA97008571A - Method and apparatus for fluid cleaning a conti impression ink jet nozzle

Info

Publication number: MXPA97008571A
Application number: MXPA/A/1997/008571A
Authority: MX
Inventors: J Paroff Paul; Haan Henk; J Rowland Roger; V Moscate Anthony; C Chapin Kenneth; A Graziano Michael
Original assignee: Moore Business Forms Inc
Priority date: 1995-05-09
Filing date: 1997-11-07
Publication date: 1998-02-01

Abstract

The present invention relates to an ink jet printer head, characterized in that it comprises: a) a set of nozzle orifices through which droplets of ink are projected onto a path or path to a substrate for printing and a surface front of the set of nozzle orifices have channels passing between the orifices; b) a nozzle plate positioned between the set of nozzle orifices and the substrate and separated by a space of the assembly, the nozzle plate has a slot aligned therewith; to the path or trajectory to allow ink droplets to fly through the slot; and c) a stream of liquid cleaning fluid circulating in the channels of the front surface and through the space between the nozzle plate and the assembly of nozzle orifices, wherein the liquid fluid stream circulates while ink droplets project from the nozzle orifices during printing.

Description

METHOD AND APPARATUS P? KA CLEAN Culi DO YOU LIVE A NOZZLE? FIELD OF THE IONVENTION The invention retains the fields of the printing nozzles and, in particular, the drip-on-demand printing nozzles, such as the ink jet and bubble jet nozzles. The invention has a problem in the problems associated with dust, with other paints and with the tip that will disturb and clog these printing nozzles during run-on or continuous. lb BACKGROUND AND COMPENDIUM OF THE INVENTION Bubble jet printers and drop-on-demand inkjet printers (collectively referred to as ink jet printers) drive the ink droplets tubs from the nozzles onto a paper substrate adjacent to the nozzle. Examples of these types of printers are the Cannon nozzles known as liCOl and ÍiC? Z. Ai control with precision the trajectory and the moment From the ejection of the ink droplets, the ink jet nozzles print clear spots on the paper. To achieve accurate placement of the ink droplets, the inkjet nozzles should be provided with clear, clean holes for the droplets to pass through as they fly from the nozzle to the surface of the paper. In a conventional demand drip ink jet nozzle, a plurality of holes are located on the surface of the nozzle from which the ink droplets are driven. During printing, the ink is ejected out of the selected holes in the assembly to form the desired images on the paper. The discharge of the ink droplets and especially their impact on the surface of the paper creates a fine mist of ink that covers the surface of the nozzle. Also, during the ejection of the droplets, the external ink is sprayed and deposited on the surface of the nozzle adjacent to the orifices. These ink mist coatings attract paper fiber, dust, sand and other types of particles that can clog the nozzle orifices and block the ink droplets being sprayed from the nozzle. Also, the external ink id can accumulate in a way that blocks the holes. Consequently, there is a need to regularly clean the nozzle plate of the ink jet printers b so that the set of holes remain clear of ink and particles that would otherwise interfere with the printing of the ink on the paper. Previously, the inkjet printers had been cleaned by means of cleaners that cleaned the plates and the orifices of the nozzle. Between print jobs, the print head moves away from the paper roll to a cleaning station where it desiizates against a cleaner. These cleaning rollers pass through the surface of the nozzle plate and the orifice openings to remove particles that may be clogging the ink in the nozzles. Because the cleaners temporarily clog the nozzles, the cleaners are used only when the jet printers are not printing. b For example, a cleaner can be placed at the distant edges of the carriage path beyond the edges that hold the paper adjacent to the carriage trajectory. Examples of cleaning systems are described in U.S. Pat. No. b, 12b, 7bb, entitled "0 Ink Jet Registration Apparatus Having Cleaning Means for Cleaning a Registration Head" and in the German Patent Document No. DE 3, bl7,7b4 A. The cleaners they have proven to be generally acceptable for the application of printing on desks b where each individual printed work is relatively short and when the print nozzles are cleaned between intervals the cleaning is relatively short. In a normal desktop inkjet printer the carriage with the plaster jet print head can be moved to a cleaning station after each printing operation. This way in the usual desktop application, printing nozzles are often plyed by conventional cleaners and do not tend to clog with particles. With printing fed with continuous roll, the print nozzle is required to print constantly for many hours. This differs with normal desktop printing applications where each printing operation is carried out over a relatively short period. The displacement of the print head to a cleaning station remote from the paper to be printed necessarily interrupts the printing operation of a continuous printer. Although these interruptions or substantially interfere with the normal desktop printing jobs do not interfere with the commercial printing of continuous paper. In this regard, the conventional inkjet print head has been found to require cleaning during each JO at 60 minutes of continuous printing. The remote cleaning stations for inkjet printers are undesirable for commercial continuous printers since the printing operation must be interrupted every half hour to an hour for cleaning nozzles. Accordingly, there is a need to experience an apparatus and method for cleaning an ink nozzle without interrupting a printing job. Other techniques for cleaning the surface of the nozzle of a prior art inkjet printer are to clean with air jets in or around the nozzles of ink to blow particles from the surface of the nozzle or to prevent particles from adhering to the surface of the nozzle. Some of these techniques have included the use of ionized air to neutralize the static charges on the dust particles that attract dust to the nozzles. These techniques have only achieved partial success as reported in the U.S. Patent. No. 4,411.70b, entitled "Method and Apparatus to Remove Dust from Inkjet Printers". While the nozzles are cleaned with an air jet, the nozzles are sprayed with ink, and the turbulent air flow caused by the fans of the previous technique interrupts the path of the droplets of TiT hcLC ± d. paper. Since the previous systems to clean the inkjet nozzles have been less than If satisfactory, there has been a great need to experiment with a technique to electively clean the nozzles. Said need has not been completely satisfied until the present invention. The present invention relates to a technique for cleaning an ink jet nozzle with an ink jet, such as air or air that flows through the surface of the print nozzle and entrains dust and paper particles. that is Lúlii i eii to the surface of the nozzle. Once captured in the fluid, the particles are removed from the nozzles through the fluid flow. In one embodiment of the invention, a fluid stream flows through the nozzle surface of an inkjet printer to clean the printer. This current is located next to the nozzle assembly at which the droplets of ink are driven. Dust and paper particles that could otherwise clog the nozzle assembly are entrained by the fluid stream before they clog the nozzle orifices. A fluid source drains the supply of The fluid and network of fluid channels on the nozzle creates a fluid current path adapted to remove particles and dust in the vicinity of the nozzle assembly. The fluid flows continuously through the surface of the nozzle, ink, sand and 2b paper particles are continuously captured and removed from the nozzle assembly. In some embodiments, the current of the product does not interrupt the projection of the ink droplets from the ink set and, thus, does not interfere with the printing. A. In a first embodiment of the invention, the cleaning fluid is confined to the channels adjacent to the OL of the nozzle. The holes are not cleaned with the fluid. Accordingly, the ink jet nozzle can print while the cleaning fluid is flowing because the fluid flow does not obstruct or interfere with the droplets of ink ejected from the nozzle to the paper. Accordingly, the first embodiment of the present invention provides the apparatus and technique for continuously removing particles from the surface of an ink jet printer while printing continues. In a second embodiment of the invention, the cleaning fluid flows directly over the holes of the printing nozzle to wash the holes and the nozzle in general. Printing is interrupted while the holes are washed using the second mode. This method of washing the orifice of the invention washes away any residue of ink, dust or paper fibers that clog the orifices. In this way, the second mode provides a more thorough cleaning of the print nozzle of b than does the first mode. The second mode of / the invention can be used in conjunction with the first embodiment. In a third embodiment of the invention, the holes of the nozzle assembly are protected from dew and b from ink splashes by a nozzle plate. The nozzle plate is placed between the holes and includes a narrow slot through which the ink droplets are discharged. The nozzle plate is separated by a small hole from the holes of the nozzle and drains excess ink through this gap out of the nozzle holes. This third embodiment can be used in conjunction with the first and second embodiments of the invention. An object of the present invention is to clean the nozzle assembly lb of an inkjet printer and to prevent ink, dirt and paper particles from clogging the orifices of the nozzle assembly. It is a further object of the invention to continuously capture and remove the particles and ink from the set of nozzle while the nozzles are printing and wash the nozzles completely at other times. A further object of the invention is to extend the period of free printing maintenance of ink jet printers and to reduce the frequency of interrupting the 2b printing in the event that cleaning is required by the ü printers that ink jet. In addition, another object of the invention is to improve the print quality of inkjet printers by overcoming many of the problems caused by foreign paper particles and sands that have clogged previous ink jet printers. These and other objects are achieved by the invention which is illustrated and described in detail below.

UH.EVE DESCRIPTION ÜE THE DRAWINGS The invention will be explained in more detail with reference to the drawings identified as follows: Figure 1 is a cross-sectional view of an ink jet printer head with a cleaning mechanism with the associated fluid, forming a first embodiment of the invention; Figure 2 is a front view of the surface of the ink jet printer head illustrated in Figure 1; Figures 3 and 4 illustrate front and cross-sectional views, respectively, of another embodiment of the invention; Figure b illustrates a front view of a b additional embodiment of the invention; and Figures O and 7 illustrate a front view of yet another embodiment of the invention.

DETAILED DESCRIPTION OF THE MODALITY yH BERLDA The Fixture 1 illustrates an ink jet printer head 10 mounted co or a carriage on an arrow 12 in a printing mechanism. In particular, the printing mechanism can be a printer fed with conventional continuous roll, which computes a large volume of printing. It is common that the speed of the roll in these printers is of yi.4 m per minute and has a scale of speed of operation of? Ü.y to lb2.4 m. of roll per minute. Furthermore, these printers operate continuously and will print normally for periods as long as twelve hours without interruption, with the condition that the inkjet printer does not require cleaning during that period. The paper or other roll substrate moves with or band 14 in the direction of arrow lb. The web moves across the surface of a plate lb adjacent to the print head. The platen places the print roll directly upstream and generally parallel to the ink jet head. The printing mechanism may include b conventional roll handling assemblies (not shown), for example traction feeders, for moving the roll at a predetermined speed, in a precisely controlled shape and along a predefined trajectory. The ink or print head is attached to the arrow by means of a support 17 of inan L so that the print head can be sanded in position on the wing and arranged in a set with other printheads uniformly spaced across the width of the head. the band. Alternatively, the print head can be slidably mounted on the arrow, and moved from one part to another through the arrow in a controlled manner during printing, to place the print head with respect to the moving web. The support can also include fins l? ' that dissipate the heat of the ink jet printer head. A thermocouple can be attached to the base of a fin of the head to detect the temperature of the print head. The support can be formed of aluminum or of any other material that is suitable for securely holding the ink jet nozzle assembly. The ink jet nozzle assembly includes a plate l? Mounting on the front surface of the print head holder 17. The mounting plate retains the print head in a recess 20 of the holder. The plate overlaps the recess of the support and is removably attached to the support by screws or other fastening devices. The mounting plate includes a rectangular slot 21 through which protrudes the front nose of the print head. The openings in the nozzle assembly 23 are located on the front surface of the nose of the print head. The mounting plate can be made of machined copper and coated with an indigo coating., v.gr. Teflon, in and near the area of the holes, to reduce the tendency for excess ink to clog the holes. The nozzle plate 24 overlaps the mounting plate and nose of the print head. The nozzle plate is attached to the mounting plate or support by screws or other fastening devices. A seal 2b can be placed between the nozzle plate and the mounting plate preventing the cleaning fluid from leaving the space between the two plates. Further, the nozzle plate includes a narrow slot 2b aligned with the set of holes in the nozzles 23 of the print head to allow the ink droplets to fly from the holes through the slot 2b and into the web. paper 14. The slot is in alignment with the set of holes in the nozzle. In addition, the slot has an open area that is only slightly larger than the area of the nozzle assembly. The nozzle plate partially protects the nozzle assembly from ink splatters that strike the baoua uo papui. The plate that the mouthpiece can be lined with a porous matoriai so that the ink splashed on the plate of the mouth can be extracted through the plate and the hollow between the back of the plate of the mouthpiece and of the toothpick. of assembly. The nozzle plate protects the print head from the splash of the ink droplets as they impact on the paper web. The ink spray is collected on the outer surface of the nozzle plate instead of splashing back onto the nozzle assembly. In addition, the tint that drips into the gap between the mold and the nozzle plate is protected from the fibers of the roll and from the paper and other particles that tend to be attracted to the surfaces wetted with ink. The ink that congregates on the surface of the nozzle 4tí of the print head does not collect the fibers of the roll and other particles due to the nozzle plate. It is believed that the presence of the nozzle pin can only extend for several hours (as opposed to O.b to l.b hours) the period during which the nozzle of the print head can reliably and continuously print between cleanings. The ink droplets 27 are propelled from the holes of the nozzle 23 in a direction towards the paper web 14 for printing. As the droplets impact the roll, most of the ink remains as points, or other indications. Some ink will splash as it hits the paper and a mist of ink particles. In addition, he spoke to some residue of ink mist that arises from the ejection of the ink chips from the orifices of the nozzle. This ink mist flows in the vicinity of the tip of the nozzle, the nose of the printhead 22 and the paper roll, and tends to settle on these surfaces, with a coating 34 of coarse ink that accumulates in accordance continue printing. Since the roll of paper moves, the accumulation on any other section of the roll is not evident. The print head does not move. Consequently, ink accumulated on the surfaces of the print head can pose problems, which will be solved by the present invention. The impact of the ink droplets, the movement of the paper roll and other factors cause the paper fibers and other tub particles 3b to be dislodged from the roll and other surfaces and float in the ink mist.

In addition, as the ink accumulates around the nozzle caused by the ink mist, some of these particles contribute to the accumulation of ink 34 and particles in the vicinity of the ink jet nozzles. If this accumulation is allowed to continue without being removed by the 2b cleaning, the accumulation will clog the holes in the nozzle 2J and interrupt the printing of the ink. Although the nail plate protects the printing caoe of many stray particles and the spray of ink, the nozzle plate does not completely avoid the need for cleaning with a set of orifices from the mouthpiece. The present invention also includes a technique for removing the ink and the accumulated particles that surround the orifices of the nozzle while the printing continues. It has been found that by discharging a fluid, such as water or air, through the nose surface of the print head, so that the ink and the particles covering the nozzle assembly can be washed. In one embodiment, the water is supplied to the gap 40 between the mounting plate and the nozzle plate 24 from a water source via the conduit 42 that passes through the support 17 and the mounting plate and is discharged. from a relatively large opening or openings 44 on the front surface of the mounting plate. The fluid discharged from these openings enters the gap 40 between the mounting and nozzle plates and flows downward, as indicated by the arrow 4o, between the plates and towards the nose 22 of the print head. As the fluid reaches the nose 22 of the printhead, it is wetted and bisected on the front surface 4c of the nose. By doing so, lb the ink, the fibers and the wet particles that cover the front surface of the nose are washed with the rain. Flushing with the ink, fibers and other particles flow down through the clog between the mounting plates and the nozzle until they reach a suction opening in the mounting plate. Due to a light suction applied in that opening, the fluid is drawn into the opening and out through conduits b2 to discharge (not illustrated). Ei Fugue, water or other liquid, if they can be discarded or filtered and recycled through the printer. Alternatively, the fluid removed by suction in the suction opening b, may be only the excess ink in the gap 4U between the mounting and nozzle plates. The suction of the fluid will create capillary forces in the hole that draws the ink down through the gap into the suction opening and out of the nozzle assembly. In this alternative embodiment, a separate fluid source, supply conduits 42 and fluid discharge ports 44 on the printhead are unnecessary, because the excess ink itself is used with the cleaning fluid. If a flushing fluid, such as distilled water, is supplied, then the impression may have to be interrupted or may continue while the fluid flushes the front surface 4t of the nozzle, depending on the The trajectory of the output of the product through the super- vision of the whole group. If the nail is dense through the entire nozzle assembly, then the fluid will wash across the holes. Although this dense flow is particularly elective for cleaning the clogged printing orifices, the illu- minary interferes with the projection of the ink droplets, and, from this, the printing can be interrupted or even stopped by the dense flows. of the cleaning fluid. Alternatively, a flow of light fluid confined to the channels b4 in the mounting plate and / or in the front surface 4ü of the nozzle can be used while printing continues because the channels are not cut through any of the holes that interfere with the ink flow. Excessive dirt, fibers and other particles can be attracted to these channels by coating the channels and surfaces near the channels with hydrotilic coatings. The fluid in the channels carries the ink, fibers and other particles out of the front surface of the nozzle assembly and of the suction opening bO. In another alternative embodiment, as illustrated in idS Figurds 3 and 4, [the same numbers of Figures 1 and 2 have been used in these figures to refer to features that are common in all figures], the b single fluid path of the first modality has been changed to a system of 1luido of trajectory double shovel clean the exees? of ink, paper and other particles. This washer wash, which is intended to be used as long as the print head is not urn, since washing may interfere with the printing operation. A pair of flux ducts oO, Ü2 extend through an upper portion of the support to the print head 1 / from a pair of outlets ü4 of a fluid source [not shown] towards the first and second fluid discharge ports,? O, bb, respectively. In this embodiment, the nozzle plate is fixed directly to the mounting plate by means of screws 74 or other fixing means. The first discharge orifice ob opens from the support 17 out of the recess 70 between the pin of the nozzle 24 and a section of the front surface 1 of the support and of the print head, the section of which includes the surface of the trunk. the nozzle 4b. The fluid flows down through this gap until it passes over the ios orifices i of the nozzle assembly. Below the nozzle assembly, the front surface of the print head falls back along an inclined section 74 until it meets another vertical section 7b that terminates in the suction opening bü of the support. The surface B slopes wide the 7U hole inside a container It is a relatively large amount of fluid that collects, excess ink, the fibers of the roll and other accumulated particles. The fluid escapes downwards into the container and is extracted by the capillary forces of the suction opening b bU of the support. Similarly, the second flush conduit releases the fluid to the second flush port, b, which may constitute a row of openings as illustrated in Fixture 4, through which the Fugue exits. super iicie bO of the piaca of the nozzle i. The fluid wets and flushes the front surface of the nozzle plate as the Flue flows down and traverses the surface of the plate. Within the second slot of the nozzle plate 24, portions of the fluid can flow around, lb over and into the slot. The fluid that flows around and over the groove, washes the ink and the particles that have been collected on the plate. This external fluid path, the ink and the particle mixture continues its flow down onto the nozzle plate [surface tension] keeps the runaway current on the surface of the plate] until the runaway is withdrawn into an opening b2 in the mouth of the nozzle in communication with the suction opening bO in the support. The fluid that is extracted from the groove 2b, flushes the groove and is drawn into the cavity 7d 2b between the nozzle plate and the printhead, from and where the fugue, the ink and the mixture of particles are extracted by the suction opening bO of the support. Figure b shows another embodiment of the invention wherein a pair of flushing streams flow through the ironing surface of the nozzle 4b on either side of the nozzle assembly to clean the ink from the surface. 4b unenti as follows the impression. This modality can be used with or without a nozzle plate [according to the illustrated]. A pair of horizontal flusher ducts I, 2 and 2 mounted on or inside the mounting plate 1 are connected to a fluid source [represented by Figs 4] and discharged from the opening or adjacent to the front surface 4b of the nozzle of the print head. The fluid from the discharge openings enters a pair of horizontal channels, 100 which are parallel to and on opposite sides of the nozzle assembly 23. The channels and surfaces near the channels and nozzle orifices can be coated. with a hydrophobic material so that the ink will not be allowed to accumulate in these areas and will be extracted from the channels and washed out of the channel. As the fluid in the channel reaches the opposite end of the channel, the fug is sucked out to the openings 102, 104 on the mounting plate. These openings are connected to ducts 10, 10b which are also necfluous to a drain 11U which imparts suction to the ducts and to the openings 2, 4 to extract the solution through the channels. The directions u and / illustrate another embodiment of the invention specially adapted to use air [or other air as a cleaning agent. A multiple air streams 112, such as an oval shaped jet, provide a flow of horizontally directed pressure air [Fig. or] or see ticaimente [F g. /] through the front surface 4o of the nozzle assembly ¿or. The bellows manifold is connected to a compressed source [n? illustrated]. The pressure of the air stream is drawn onto the wetted ink towards the front surface of the nozzle assembly and causes the ink [including pounds and other entrained particles] to run out of the shaft 112 and emit a vacuum manifold 114, which can have a shape similar to that of the bellows. The vacuum manifold picks up the ink flow and directs it [see arrow lio] to a drain [not illustrated]. In addition, the vacuum manifold can be connected to a vacuum pump to draw air through the nozzle assembly and into the manifold. Depending on whether the flow pressure of the jet through the nozzle assembly interrupts the path of the ink jet nozzles, the bellows and vacuum manifolds may or may not be operated while printing continues.

The invention is described as mdiiera that is considered to have the modalities as practical and preferred. The invention is not limited to the modalities described, but covers the various modifications and equivalent provisions included within the spirit and scope of the appended claims. lb twenty 2b

Claims

CLAIMS AMENDED SHEET 1. An ink jet printer head [lü] comprises: a. a set of nozzle holes [? ] through which the yotitas de ti ta [27] are projected onto a path to a substrate for printing; b. A nozzle plate [24] is placed between the set of nozzle orifices and the substrate and separated by a gap in the assembly, the nozzle plate has a slot aligned with respect to the path to allow the ink chips to come out through the slot [2b]; and b c. a flushing stream [4?] injected into the hollow at a location adjacent to the orifices of the nozzle, passes through the holes, and is withdrawn from the hollow at a location downstream of the flushing stream from the orifices.
2. An ink jet printer head [lü] according to claim 1, further comprising a front surface of the print head on which the set of nozzle holes [23] is placed, and wherein the plate The nozzle is separated from the surface by the ironclad [40] and the tip of the nozzle [24] that covers the super fi cial nontal. J. A single ink jet printer [10] as claimed in claim 1, wherein the slot [2b] in the nozzle plate [24] has an area that is slightly larger than the area of the nozzle. nozzle orifice set Í ¿J > 4. An ink jet printer head [10] as claimed in claim 2, wherein the nozzle plate [2b] is formed of porous, ink-adsorbent material. b. An ink jet printer comprising: a. an ink-jet printer head [10] having a front surface and a set of nozzle holes [23] disposed on the front surface, wherein the ink droplets [27] are projected through the orifices a io along a path to a substrate [14]; b. a support [17] having a recess adapted to receive the ink jet print head; c. a mounting plate [iy] removably affixed to the support and securing said inkjet printer head in the recess, the mounting plate having an aperture in which the iron surface of the inkjet print head projects;; d. a nozzle plate [24] attached to the mounting plate b and covering the opening in the mounting plate and separated by a recess [40] from the front surface of the ink jet printer head, wherein the plate the nozzle has a groove [2o] aligned with the set of holes of the nozzle and through which pass 10 yots of the ink jet in its path, and e. a flushing stream [4b] injected into the hollow at a location adjacent to the orifices of the nozzle, passes through the orifices, and is drawn from the hollow to a location downstream of the exhaust stream of Ib the holes. b. An ink jet print head according to claim b, further comprising a stream of cleaning fluid flowing through the front surface of the ink jet print head. 7. An ink jet printer according to claim b, further comprising a stream of cleaning fluid [4b] fleeing within the gap between the nozzle plate and the front surface of the print head. 2b 2b 8. A ink jet printer head of con? Rmation with claim 7, wherein the nozzle plate [24] has an ironfal surface [b?] In front of the substrate and a rear surface in front of the printer head, and the plate The nozzle is porous so that the ink splashed on the iron surface is extracted through the nozzle stem and washed by the flushing stream. Y. An ink jet printer in compliance 10 with claim 7, which further comprises a second rip current on a front surface [bO] of the nozzle plate in front of the substrate and wherein at least a portion of the second rip current is drawn through the slot [2o] of The lip plate of the nozzle that is driven with the cleaning fluid stream. 10. An ink jet printer according to claim 7, wherein the front surfaces of the print head are grooved with the channels. , 20 100] for cleaning fluid streams. 11. An ink jet printer according to claim 10, wherein the channels are coated with a hydroiobic material. 12. An inkjet printer in accordance with 2b with claim b, wherein the gap between the The iron surface of the inkjet printer and the nozzle plate are enlarged to form a container [7b] below which set of nozzle tips. b 13. a conformance ink jet printer with claim b, which further comprises a suction opening [b2, bU] in the holder and is placed by the tester? of the bore hole assembly and the suction opening having a light vacuum to extract excess ink from the 10 between the inkjet printer head and the ink plate. 14. An ink jet printer according to claim 7, further comprising a suction opening [bO,] on the support and located below the set of holes of the nozzle and the suction opening having a vacuum. light to extract the fluid stream after the current running through the front surface of the print head is washed. lb. An ink jet printer in compliance 20 with claim 14, wherein the nozzle plate includes an opening aligned with the suction opening [bü, b2] of the support and causes the escape to escape on the nozzle plate which is withdrawn towards the opening of the plate and also towards the suction opening. 2b 16. An ink jet printer according to claim 1, wherein the cleaning run is a gas. 17. A conormity ink jet printer with claim 7, wherein the flushing fluid is a liquid. lb. A method for cleaning an ink jet print head [10] having a front surface with a set of holes [?] Of the nozzle, and a nozzle plate [24] separated by a hole [4?] Of ia. front surface of the print head, the method comprises the following steps. to. driving the ink from the nozzle assembly through a slot [2o] of the nozzle plate and towards a band [14] to print on the web; b. protect the op- tions of the splash of ink and fibers and particles carried by the air with the nozzle plate; c. Draining the excess ink on the assembly under the nozzle through the gap between the front surface of the print head and the nozzle plate, And d. inject a cleaning fluid into the recess to make the escape flee through the nozzle assembly. b 2b 19. A method for cleaning a printing ink head of compliance with claim lb, further comprising the step [d] of washing the front surface of the print head with a rip current b [4b] and in step [c] drain the stream of Fugue [bü] and the excess ink. 20. A method for cleaning an inkjet print head of compliance with claim 1, wherein the nozzle plate includes a channel [yb, l ?? j 10 adjacent to the orilicios and step [d] is also practiced by making the current of escape through the Cdiidl. 21. A method for cleaning an ink jet print head in accordance with claim i, wherein step [d] further includes washing the surface The ironing of the nozzle plate with a stream of fluid and extracting a part of the fluid stream that passes through the nozzle plate through the slot [2o] of the nozzle plate. twenty 2b Y