ES2399478B1 - METHOD AND DEVICE OF FLUID SIMINIST. - Google Patents

Abstract

Method and fluid delivery device characterized in that said fluid is supplied at constant pressure (P {sub, m}), at a supply point located between a distributor (7) and a return manifold (8), by using two pumps (2), which act in a controlled manner, so that one of them (2i) performs a fluid impulse, from a main tank (1), to a fluid distributor (7) exerting a certain pressure (P { sub, 1}), while the other pump (2r), performs a suction action on said return manifold (8), applying a certain pressure (P {sub, 2}) on the return manifold (8), and the difference between both pressures (P {sub, 1} -P {sub, 2}), is constant and preset by the control system as a set point (P {sub, m}), and that can be applied, by way of non-limiting example, the supply of fluids from a printhead and contains the priming and purge functionality in heads? through flow? or? non through flow ?, including said device, heating and cooling functionalities of said fluid.

Description

Technical sector

The present invention relates to equipment and techniques, which require a continuous, or timely, supply of fluids at a given pressure, in a controlled manner, whether it is equal, superior, or less than atmospheric (atmospheric, pressure or in depression), and it is especially useful, when said fluids contain dispersed solids, whose possible sedimentation and / or flocculation, can cause said devices to malfunction.

The design of fluid feeding devices, to deposition or printing equipment, by means of inkjet,

or inkjet (generically called "InkJet" in the technical literature), such as printheads (better known as "printhead" in the technical literature), has been subject to a very large number of patents, since the appearance of this technology.

The present invention preferably refers, but not exclusively, to this field of the art, and more specifically to printing systems using the technology known as "drop on demand" (DOD), or injection on demand, as opposed to the other technology known as "continuous InkJet" (CIJ), or continuous injection.

More specifically, and not limitatively, it refers to inkjet printing equipment with piezoelectric actuators (piezo-inkjet) or thermal heads (Thermal InkJet), although in the description of the invention, its applicability will be illustrated with examples in the first case, in particular, due to the existence of two different technologies in terms of ink feeding, "through flow" technology or active system, and previous passive system technology.

Prior art

One of the critical aspects to take into account, in the application of inkjet technology to printing processes, lies in the way in which the fine nozzles of the printheads are fed with the fluid to be ejected, of so that, in said injector, and more specifically in the outlet opening (nozzle in the literature), located on the nozzle plate (nozzle plate in the bibliography), a meniscus is formed, which must be subjected at a balanced pressure, to avoid the backward flow of the fluid (lowered), or an uncontrolled flow of it outwards.

Said pressure is known in the art as "meniscus pressure", which is defined by the characteristics of the fluid (density, viscosity and surface tension) and the nature of the materials that constitute the injectors and nozzles.

Meniscus pressure, usually, and should, have a negative value with respect to atmospheric pressure, easily explained by Jurin's law, which defines the height a fluid reaches (and therefore hydrostatic pressure), when the weight of the liquid column and the ascending force per capillarity, due to surface tension.

Thus, the state of the art offers numerous solutions to obtain and maintain this "meniscus pressure" with different advantages and disadvantages.

Among other solutions, we must indicate the one used by the applicant in their KERAjet K300, and K700 products, and that is schematically reflected in Figure 2. In said solution, the meniscus pressure is maintained by the difference in height (h) between the free surface of the fluid contained in a regulating tank (20) and the surface of the printhead nozzle plate (10), so that Pm = pgh, where p is the density of the liquid, g the acceleration of gravity and h said height difference .

Said meniscus pressure is usually equivalent to a height difference of between 20 and 200 mm, corresponding respectively to 2 and 20 mbar (in the case of density equal to one).

In said figure 2, the fluid supply system consists of a regulation tank (20) that maintains a constant level through level transducers and the action of a pumping system (2) through a filter (4) from a main deposit (1). Said configuration is known as "passive feeding system" since there is no continuous movement in the supply lines (5) that deliver the fluid to the feed distributor (7) located in the head bar (40) and from there to the printheads (10). The meniscus pressure is defined by the difference in height (h) between the free surface of the fluid in the regulating tank (20) and the plane of orifices of the injectors (nozzle plate).

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A passive feeding system, such as the one described, even allowing the fluid to be recirculated continuously, between the main tank (1) and the regulation tank (20) by any procedure, such as an overflow set at a height (h), which It defines the meniscus pressure, has been used intensively and provides sufficient flow to the printheads (10) if the sections of the pipes (5) and distributors (7 and 8) are suitable.

In the field of commercial office printers, another different passive system is used, consisting in that the main tank is directly connected to the printhead (10) and this is subjected to a constant pressure, regulated automatically, by applying a certain pressure to the fluid in the, directly or through membranes, by mechanical or pneumatic means.

The appearance of printheads (10), which act under the principle of internal recirculation (through flow principle), such as Xaar-1001 models of Xaar plc (GB) or KM-1024 of Konica Minolta (JP), in the that there is a fluid inlet duct and an outlet duct, which allow to establish a continuous circulation of ink inside the head, makes it necessary to use new fluid supply systems, which take advantage of these printheads, such as the possibility of preventing the nozzles of the injectors or the nozzles, by sedimentation of solids, thanks to the continuous recirculation of the ink and that the new problems of meniscus pressure stability are solved, these systems are known as the "system of active feeding. "

Among the different solutions found, Robert Harvey, Stephen Temple and others, in patent EP 1425177-B1 (Droplet deposition apparatus) of priority date 11.09.2001, describe (fig. 1a) a deposition apparatus (printer) which has fluid supply means under pressure to the head injectors, pressure control means (64), located in the liquid supply to each printhead (56,58,30), to adjust the pressure of the liquid in each injector in the process of expulsion (injection) of liquids. In this patent, said supply system is characterized as described in Figures 4 and 5, by the existence of a supply tank (54), a control tank (64), restrictors (60.62) or resistors of flow and a pump (52) that recirculates the liquid to the heads and / or the control tank, depending on the resistance offered by the resistors (56, 58, 60 and 62).

Subsequently, Pau Drury, Stephen Temple and Michael Purser, in WO2006 / 030235-A2 (Fluid supply method and apparatus) of priority date 18.09.2004, describe a method and apparatus (fig. 1b) for the supply of fluid to a deposition device or printhead that uses the flow principle through the printhead or head (flow principle).

The pressure of the liquid entering and leaving the printhead is controlled directly at the printhead by the respective pressure controllers, preferably a transducer and a control system.

The supply system according to figures 5 and 6 forms a closed loop including a remote reservoir, and the entire system is organized in such a way that the free surface of the liquid in general is exposed on average, to a negative pressure, there is a circulation closed by the operation of a pump and a flow resistance, from the ink tank through the printhead, while Figure 8 shows a supply system that involves the use of two complex ink tanks communicated with each other by means of a pump and with the printhead, so that the application of suction on one of them establishes between the inlet and outlet of the head the necessary negative pressure.

Hideo lzawa, Takao Namiki, and others, in patent WO2006135077 (lnk supply device in InkJet recorder) of priority date 13.06.2005 and requested by MIYAKOSHI PRINTING MACHINERY CO., LTD describe a similar, but more complex, device in which a pressure tank (15) connected to a head (2) is required by an ink supply path, a main tank (9) connected to the pressure tank again by a main supply path (16) with a pump main ink (18), a recovery tank (7) connected to the main tank by a return path with an ink pump (22), and a drain (5) connected to the recovery tank through a recovery path ( 8) that has a recovery pump (6).

Kia Silverbrook, John Douglas Morgan and others, in WO 2007/098527 A1 (Printer wlth active fluidic architecture) of priority date 03.03.2006 describe an inkjet printer having an ink supply (112), a printhead of print consisting of integrated circuits (IC) (74) in communication with the ink supply through an upstream ink line (67), the print head IC (74), a waste ink outlet in fluid communication with the print head IC (74) through a downstream ink line (106), an upstream shut-off valve (138) in the upward ink line (67), and a downstream pumping mechanism (114 ), with a valve upstream of the printhead and a pump downstream of the printhead, the user has active control of ink flow upstream, downstream or at the printhead IC.

Additionally, Kia Silverbrook, John Douglas Morgan and others, in WO 2008/006132 A1 (Inkjet printhead with controlled de-prime) dated priority 10.07.2006 describe an inkjet printer having an ink supply, a ink distributor, in communication with the ink supply, a print head with IC and a series of ink ejection nozzles mounted on the ink collector, a pump in a communication with the fluid and a gas inlet that can be open to establish a fluid communication between the ink and a gas supply, which can be closed to form a gas-proof seal. The ink dispenser can be fed using the pump by closing the gas inlet, and depressed when the gas inlet is open. This allows the printhead to be depressed during storage and transport and allows the printhead IC to be cleaned by a foam formed by forced air through the ink nozzles.

For his part, Georg Grossrubatscher, in WO 2008 / 138586A1 (Ink supply system for an InkJet printer) of priority date 14.05.2007 and requested by DURST PHOTOTECHNIK-A.G. describes an ink supply system (2) for an inkjet printer (1) with a printhead distribution (6) for at least one color, printhead distribution (6) comprises a plurality of printheads print (7) each with a plurality of nozzles and the print heads (7) are aligned to form a total of the width of the print area (10) corresponding to a multiple of the print area width (9) of a single print head (7). Each of the printheads (7) is connected through a line to an intermediate tank (12) for the ink of the corresponding color, a plurality of printheads (7) is connected to a common intermediate tank (12) .

For his part, Simon Bennett, in WO2009077790A1 (Recirculating ink system for InkJet printing) of priority date 18.12.2007 and requested by XENNIA TECHNOLOGY LIMITED describes an ink tank (10) for an ink recirculation system for delivery Ink to an inkjet print head (14) comprises a first chamber (16) for receiving ink from a main ink supply (12) and with an outlet to the head (24) for ink supply to a printhead (14), and a second camera (18) in communication with the first camera to receive excess ink from it above a predetermined height in the first chamber determined by the position of a transfer medium (20) , the second chamber with an input of the printhead (30) for receiving ink recycling and the printhead with a return output

(40) to return to the main ink (12) of ink supply the excess of a predetermined height in the second chamber by the position of the return outlet (40), the transfer output, in use, being vertical by above the return outlet (40).

In use, this reservoir, since the transfer socket (20) of the first chamber is vertically above the return outlet (40) of the second chamber, produces a pressure differential that causes the ink flow of the first chamber (16) to that of the printhead (14) through the exit of the printhead (24), through the printhead (14), and returned to the second chamber (18), to through the printhead inlet (30). The ink used is returned to the main tank (12) for reuse, whereby excess ink circulates through the system.

The system then uses gravity to produce the flow of ink through the printhead (14), without the need for pumps, level sensors, valves, etc. The ink tank is self-regulating, with the ink heights in the first and second chambers, and therefore the pressure differential, is determined by the relative heights of the two exit points.

On the other hand, Vincenzo Palumbo, in patent EP2093065-A1 (An ink supply system for printers) of priority date 19.02.2008, describes an ink supply system for printers (fig. 1c), also characterized in creating said pressure negative by using two tanks with two different levels, creating a circulation of the ink through the printhead (7) from the highest level tank (2) to the lowest level (3), by the difference in height of these levels (L2-L3), maintained by a pump that re-circulates the contents of the lowest level tank (2) to the highest level (3) and by means of the first tank (2) being at atmospheric pressure and the second tank being maintained (3) at a pressure lower than atmospheric.

Finally, Xaar plc (Xaar Technology Limited) has a device called "Hydra lnk SUPPLY System" on the market, which, although it advertises an operating capacity from room temperature to 50 ° C, lacks regulation capacity for temperatures below ambient temperatures. , which is a serious problem for intensive industrial uses, or if the fluid increases its temperature for some reason, since it only equips a heating system, but not a cooling system.

Said heating system consists of a heating resistors in the supply line, whereby the response of the system is clearly improved by the device object of the present invention.

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Additionally, said "Hydra Ink SUPPLY System" suffers from limitations regarding the number of printheads, which it is capable of controlling, and the method of controlling pressure and temperature.

Disclosure of the invention

There is no prior disclosure.

Technical problem

The solutions discussed and incorporated here by reference, in the prior art, in any case, partially solve the problem, but by creating new ones, which they do not solve.

Thus, in the case of using two tanks with different heights of level, whose difference causes the necessary hydrostatic pressure, they require external adjustments of overpressure or depression and the continuous transfer of fluid from the lowest level to the highest level tank, being controlled meniscus pressure indirectly controlled by the control of these levels and does not obviate the risk of malfunction and / or spillage of fluid to the outside through the heads, in case of failure in the supply of air for suction or stopping the transfer pump from one tank to another, being able to seal the heads by sedimentation in one of them, if the flow is reversed, intentionally or accidentally.

In the case of the use of resistors, impedances, or flow resistances, these in themselves are likely to require excessive maintenance due to malfunctions due to sedimentation seals of solids.

In the case of using other tanks other than the supply tank, additionally, a problem of commissioning time is created until the equilibrium situation is reached, and the replacement of the fluid (frequent occurrence in industrial applications), entails a taxed difficulty for the consumption of fluids and cleaning vehicles.

An additional difficulty is the fact that, except in the solution proposed by Hideo lzawa, Takao Namiki (which in turn is not applicable to the heads that work according to the "through flow" principle), these systems are not applicable in a way evident to previous or future non-flow heads, which will in itself constitute a limitation in its use, by preventing the standardization of a single fluid supply system, regardless of whether or not they use the "through flow" principle.

Technical solution

Advantageous effects

The present invention allows to obtain a fluid supply or supply system, according to the concept of "active system" detailed above, which solves the problems of current systems and offers the possibility of a single homogeneous solution independent of the printhead or printhead , independent of its technology, piezo or thermal, and independent of the "through flow" or "non through flow" operating principle.

Description of the figures

Figure 1 shows the prior art.

Figure 1a shows the state of the art according to EP-1425177

Figure 1b shows the state of the art according to WO2006 / 030235

Figure 1c shows the state of the art according to EP2093065

Figure 2 shows the prior art state used by the applicant in their KERAjet K300, and K700 products.

Figure 3 schematically shows active fluid feeding device applied to the head feed (10t) of the "through flow" type.

Figure 4 schematically shows active fluid feeding device applied to the head feed (10nt) of the "non through flow" type.

Figure 5 shows an additional embodiment to that shown in Figure 4, without suction pump (2r)

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Figure 6 shows various views of an embodiment of the "through flow" head bar (42) according to the

present invention Figure 7 shows an embodiment of the present invention in which a possible configuration is shown of a head bar (42), these being of the "through flow" type.

Figure 8 shows various views of an embodiment of the "non through flow" head bar (41) according to the

present invention Figure 9 shows an embodiment of the present invention in which a possible configuration is shown of a head bar (41), these being of the "non through flow" type.

Figure 10 shows a view of the preferred embodiment of the active ink feed system of

double control (50) according to the present invention. Figure 11 shows various views of a preferred embodiment of the active ink feed system of double control (50) according to the present invention.

Figure 11a shows finished exterior view according to figure 10. Figure 11b shows a side view of Figure 10. Figure 11c shows plan view of figure 10.

Legend of the figures

one

Work deposit

2

Bomb

3

Air-dumper (pressure compensator)

4

Filter

5

Feed tube to the bar

6

Turbo return from the bar

7

Feed bar (feed section)

8

Return bar (return section)

9

Connection bars / feed-return sections

10

Printhead

eleven

Temperature sensor

12

Pressure sensor

20 Level Deposit

31 Refill tube 32 Heating circuit 33 Cooling circuit 34 Return tube 35 Feed tube 36 Level sensor (36)

40 Head bar according to prior art

41 Heads bar for printheads without "through flow".

42 Header bar for printheads with "through flow".

50 Dual control active ink feeding system.

Best way to realize the invention

The present invention describes an active fluid feeding system and device, shown schematically in Figure 3, applied to the feed of heads (10t) of the "through flow" type, where, from a work tank (1) and by actuating a pump (2i), the fluid is conducted through a supply and distribution circuit (3i-4-5-7) to the head bar (42), where the printheads (10t) are located (in this case "through flow") to, after feeding these through circulation of the fluid inside, return to the work tank (1), being driven by a return circuit (8-6-3) by the action of a new pump (2r), so that, on the circuit the pump (2i) exerts a compressing effect, and the pump (2r) a depressing effect, the difference of these effects being the one that defines the meniscus pressure inside the heads ( 10t).

Said device is equipped with an automatic control system, which by means of a control program converts the pressure signals of the pressure sensors or transducers (12i, 12r) into pressure values (P1 and P2) and manages the regime of working of the pumps (2i and 2r) so that the values of P1-P2 remain constant and equal to the meniscus pressure Pm preset.

In more detail, said Figure 3 describes a feeding system, in which, from a work tank (1) and by means of the operation of a pump (2i), preferably of membrane, and more preferably of at least double body, The system feeds the fluid, after passing through a pressure compensator (3) to eliminate residual pulsations of the pump, and after filtering on a filter (4) the fluid is conducted through a feed tube (5) to the section of feed (7) of the head bar (42), where the printheads (10t) (in this case "through flow") are located to, after feeding these by circulation of the fluid inside, return to the work tank (1) the excess fluid (only a small fraction of the supplied flow is ejected), being led from the head (10t) to the return section (8) and from it, by means of a return tube (6), return through the action of a suction pump (2r), whose pulses are am Netted by a pressure compensator (3r).

Although it is not reflected in Figure 3, said device may include a temperature control circuit and heating and / or cooling systems of said fluid, said possibility is contemplated and is reflected in Figure 10.

As anticipated, an additional advantage of the fluid feeding system and device, object of the present invention, lies in its applicability to printheads of the type "" ", and thus, in Figure 4 a system is described schematically and active fluid feeding device, applied to the feed of heads (10nt) of the "non through flow" type, where, from a work tank (1) and by means of a pump (2i), the fluid is conducted by means of a power and distribution circuit (3i-4-5-7) to the head bar (42), where the printheads (10t) are located (in this case "non through flow" for, after feeding these, via a connection (9) between the inlet distributor (7) and the outlet manifold (8), return to the work tank (1), being driven by a return circuit (8-6-3) by means of the action of a new pump (2r), so that, on the circuit the pump (2i) exerts a compressing effect, and the pump (2r) a depressing effect, the difference of these effects being the one that defines the meniscus pressure inside the heads (10nt).

Said device is equipped with an automatic control system, which by means of a control program converts the pressure signals of the pressure sensors or transducers (12i, 12r) into pressure values (P1 and P2) and manages the regime of working of the pumps (2i and 2r) so that the values of P1-P2 remain constant and equal to the meniscus pressure Pm preset.

The remaining details are equivalent to those shown in Figure 3, and as is also reflected in Figure 3, said device may include a temperature control circuit and of the heating and / or cooling systems of said fluid.

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Figure 5 shows an additional embodiment to that shown in Figure 4, in which the system presents a modification with respect to that shown in said Figure 4, as long as it does not have a suction pump (2r), nor corresponding pressure compensator (3rd). Said configuration, obviously of lower cost than that shown in Figure 4, may be equally operative for the purposes described in the present invention, although the possible actions of purging and overpressure in the meniscus, desired in start-up and maintenance processes , entails a fluid flow greater than necessary for the embodiment described in Figure 4, while on the contrary, the control of the maintenance of the meniscus pressure is simpler.

Figure 6 shows various views of an embodiment of the "through flow" head bar (42) according to the present invention.

Figure 7 shows an embodiment of the present invention in which a possible configuration of a head bar (42) is shown, these being of the "through flow" type, in which the view of section AA and the power supply (7) and return circuits (8), the pressure sensors (12i and 12r) and the meniscus pressure expression as a function of the height (h) between said pressure sensors and the nozzle-plate are evidenced .

Figure 8 shows various views of an embodiment of the "non through flow" head bar (41) according to the present invention.

Figure 9 shows an embodiment of the present invention in which a possible configuration of a head bar (41) is shown, these being of the "non through flow" type, in which the view of section AA is shown and the feeding (7) and return (8) circuits, the pressure sensor (12i) and the meniscus pressure expression are evidenced as a function of the height (h) between the pressure sensor and the nozzle-plate.

Figure 10 shows a preferred embodiment of the dual control active ink feed system

(50) according to the present invention.

Figure 11 shows various views of the preferred embodiment of the dual control active ink feed system (50) according to the present invention and Figure 10.

How to carry out the invention

The present invention describes a fluid delivery method and device, characterized in that it is susceptible to use in a wide range of applications that require precise control of the pressure with which said fluid is delivered at the point of application.

Said method is characterized, by describing the way in which, by means of the action of two fluid delivery systems, preferably membrane pumps, acting in a complementary manner and in opposition to the two possible operating capacities of these, that is, by driving fluid or sucking fluid , by means of a control system, preferably automated through an automaton, controls the performance of said impulse systems in function of the pressure values obtained from sensors, preferably of the transducer type, so that by means of a control system, preferably control proportional, integral and / or derivative, it responds to the possible pressure variations measured according to the consumptions made at the point of delivery of said fluids and allows on the one hand the maintenance of a preset setpoint pressure, and on the other hand the programmed and controlled variation of said set point if required by the ap Licensing

Thus, the described method of supplying fluids will be of preferred application, and not limited, or exclusive, to the supply of fluids to digital printing systems and preferably, to systems based on the use of DOD print heads (drop on demand ), in any of its possible embodiments (piezoelectric or thermal) and acting equally satisfactory whether they use the principle known as "through flow", or if they use others considered "non through flow".

The fluid supply device method object of the present invention further allows priming operations of the heads, priming (filling of the injectors and internal parts of the head with the fluid) and purging (pouring a controlled amount of fluid through of the nozzles of the head plate).

The priming operation consists in maintaining a meniscus pressure (priming pressure Pc) slightly higher than the working pressure (Pm), that is, Pc> Pm, for a certain time tc (priming time) thus allowing the Injector channels replace the air (or cleaning solvents) they contained before the priming operation. Said priming operation may be performed both by decreasing the rate of the suction pump, and therefore the return flow, and increasing the rate of the delivery pump and therefore the feed rate.

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The purge operation consists in maintaining a meniscus pressure (purge pressure Pp) slightly higher than the working pressure (Pm), that is, Pp> Pc> Pm, for a certain time tc (purge time) thus allowing that the channels of the injectors replace the air (or cleaning solvents) that they contained before the purge operation and the possible residues that could have dirtied the nozzles (fiber, dust, humidity, etc.). Said purge operation may also be carried out both by decreasing the rate of the suction pump, and therefore the return flow, and by increasing the rate of the discharge pump and therefore the feed rate. The system may optionally have a system for collecting excess fluid discharged in the purge process and may optionally be forwarded to the main tank previously filtered or not, if desired, but said system that is collected in the present invention by reference It is not an essential part of it, being able to opt for solutions that do not require it (dead zone shooting, spatulation, sponge collection, etc.).

The device resulting from the method of supply of fluids object of the present invention, may have control elements of heating and / or cooling subsystems of the fluid, and the control of said subsystem can be assumed by the control automaton by means of the appropriate information obtained through a temperature sensor installed in the ink circulation circuit or in the supply tank.

The fluid supply device object of the present invention is schematically described by figure 3 whose execution detail of the feed module (50) is illustrated in figure 10 and the preferred embodiment is described by the assembly of Figures 3, 6, 7 and 10.

Figure 6 shows respectively and in this order, an isometric view, where the inlet (5) and outlet (6) conduits of the fluid in the head bar (42) are clearly visible, showing both the feed distributor (7) as the return one (8) and the pressure sensors (10), a different part views an embodiment of the "through flow" head bar (42) according to the present invention. Below is a plan view of said configuration of the head bar (42) in which the feed and return ducts in each printhead are visible, and their connection to the power distributors (7) and return (8).

Next, a rear side isometric figure of the assembly is shown, in which the termination of the power distributors (7) and return (8) can be observed.

Figure 7 shows in detail an embodiment of the present invention in which a possible configuration of a head bar (42) is shown, these being of the "through flow" type, according to Figure 6, in which it is shown a side view of said head bar (42) and the view of section AA where the supply (7) and return (8) circuits, the pressure sensors (12i and 12r) and the pressure expression of the meniscus depending on the height (h) between said pressure sensors and the nozzle-plate.

Figure 8 shows various views of an embodiment of the "non through flow" head bar (41) according to the present invention, and showing respectively and in this order, an isometric view, where the ducts of inlet (5) and outlet (6) of the fluid in the head bar (42), showing, both the feed distributor (7) and the return (8) and pressure sensors (10), a part different views an embodiment of the "non through flow" head bar (41) according to the present invention.

Below is a plan view of said configuration of the head bar (42) in which the feed and return ducts are visible in each printhead, and its connection to the feed distributor (7) and return manifold (8) .

Next, a rear side isometric figure of the assembly is shown, in which the termination of the power distributors (7) and return (8) can be observed.

Figure 9 shows in detail an embodiment of the present invention in which a possible configuration of a head bar (41) is shown, these being of the "non through flow" type, in which the view of the section AA and the supply (7) and return (8) circuits, the pressure sensor (12i) and the meniscus pressure expression are shown as a function of the height (h) between the pressure sensor and the nozzle- plate.

Figure 10 shows the views in detail an embodiment of the present invention in which a possible configuration of the fluid movement subsystem (50) constituted by a reservoir (1) that can be fed through an external system is shown through the filling tube (31), according to a level control (36) and that through the action of a pump (2i) and the power supply (35), the fluid passes through the filter (4) to, through the feed outlet to the feed tube (5).

In this way, the fluid is sent to the head bar (41, 42) and returns to the subsystem through the return tube from the bar (6), through the action of the return pump (2r) and through it, return to the tank (1) by the return tube (34) whose design is made so that said return creates a turbulence in the tank that allows agitation of the fluid inside said tank (1) and prevents sedimentation of the possible solids containing the dispersed fluid.

5 This figure shows the heating (32) and cooling (33) circuits.

Said heating circuit (32) may be constituted by a resistor, or by a circuit through which a liquid circulates at a temperature greater than or equal to that desired. The cooling circuit will contain a liquid at a temperature equal to or lower than desired.

10 The operation of both circuits will be automatically regulated by an external control, depending on the desired setpoint temperature and the fluid temperature value determined by the temperature sensor (11).

Industrial applicability

The fluid delivery method and device, which the present invention describes, is characterized by being capable of use in a wide range of applications that require precise control of the pressure with which said fluid is delivered at the point of application, especially in the supply of fluids to printheads or printheads.

Claims (13)

one.

 A fluid delivery method and device characterized in that said fluid is supplied at constant pressure (Pm), at a supply point located between a feed distributor (7) and a return manifold (8), by using two pumps (2), which act in a controlled manner, so that one of them (2i) performs a fluid impulse from a main tank (1), to a fluid distributor (7) exerting a certain pressure (P1), while the other pump (2r) performs a suction action on said return manifold (8), applying a certain pressure (P2) on the return manifold (8), and the difference between the two presses (P1-P2), is constant and preset by the control system as a set point (Pm).

2.

 A method and fluid delivery device according to claim 1 characterized in that said controlled form of supply is set by an automatic control system, which controls the operating regime of said pumps (2i and 2r), depending on the signals collected by pressure sensors (12) located in the distributor (7) and the return manifold (8).

3.

 A fluid delivery method and device according to claim 2 characterized in that said automatic control is carried out by means of a programmable automaton or any equivalent means.

Four.

 A fluid delivery method and device according to claim 1 characterized in that said pumps are of the membrane or diaphragm type and preferably multi-body, and more preferably four-body.

5.

 A fluid delivery method and device according to claim 1 characterized in that said use of the pumps (2) includes a pressure compensator (3) that dampens the pulses of the pump.

6.

 A fluid delivery method and device according to claim 1 characterized in that said main tank contains heating or cooling elements, and more preferably it contains heating and cooling elements.

7.

 A method and fluid delivery device according to claim 1 characterized in that said supply point is constituted by a printhead or printhead.

8.

 A fluid delivery method and device according to claim 7 characterized in that said printhead is of the "through flow" type

9.

 A fluid delivery method and device according to claim 7 characterized in that said printhead can be of the "non through flow" type.

10.

 A method and fluid delivery device according to claims 1 and 7 characterized in that said automatic control system allows to vary the set pressure (Pm) can be increased to a priming value (Pc) to allow the filling of said head (10 ) so that Pc> Pm without loss of fluid from the holes or nozzles of the head (10).

eleven.

 A fluid delivery method and device according to claims 1 and 7 characterized in that said automatic control system allows the set pressure (Pm) to be varied and can be increased to a value (Pp) that allows said head to be purged (10) so that Pp> Pc> Pm to force the fluid out through the holes or nozzles of the head (10) to a collection or cleaning system.

12.

 A fluid delivery method and device characterized in that said fluid is supplied at constant pressure (Pm), printhead or printhead. located between a power distributor (7) and a return manifold (8), by means of the use of two pumps (2), which act in a controlled manner, so that one of them (2i) carries out a fluid impulsion from a main tank (1), which contains heating and cooling elements, up to a fluid distributor (7) exerting a certain pressure (P1), while the other pump (2r) performs a suction action on said return manifold (8 ), applying a certain pressure (P2) on the return manifold (8), and the difference between the two press (P1-P2), is constant and preset by the control system as a set point (Pm), which additionally allows vary the set pressure (Pm) by increasing it to a priming value (Pe) to allow filling of said head (10) so that Pc> Pm without loss of fluid through the holes or nozzles of the head (10) , or it can be increased to a value (Pp) q It is possible to purge said head (10) so that Pp> Pc> Pm to force the fluid out through the holes or nozzles of the head (10) to a collection or cleaning system.

SPANISH OFFICE OF THE PATENTS AND BRAND Application no .: 201030156 SPAIN Date of submission of the application: 05.02.2010 Priority Date: REPORT ON THE STATE OF THE TECHNIQUE 51 Int. Cl.: B41J2 / 18 (2006.01) RELEVANT DOCUMENTS

Category

56 Documents cited Claims Affected

X

US 6116727 A (HAGIWARA YOSHIHIRO) 12.09.2000, column 1, line 60 - column 4, line 39; figures. 1-12

X

EP 0721845 A2 (CANON KK) 17.07.1996, column 7, line 35 - column 9, line 56; Figure 1. 1-12

TO

JP 2003145788 A (KONISHIROKU PHOTO IND) 21.05.2003, Summary of the EPODOC database. Recovered from EPOQUE. 1.6-9

TO

US 2008084463 A1 (KAWASE JUNYA) 10.04.2008, paragraphs [0012], [0043-0049]; figure 7. 1-12

TO

JP 2005007720 A (CANON FINETECH INC) 13.01.2005, Summary of the EPODOC database. Recovered from EPOQUE; paragraphs [0014-0017]; figures. 1-12

TO

EP 0568419 A1 (IMAJE SA) 03.11.1993, column 3, line 5 - column 5, line 26; Figure 1. 1-12

TO

JP 2007331281 A (FUJI XEROX CO LTD) 27.12.2007, Summary of the EPODOC database. Recovered from EPOQUE; figures. 1-12

TO

US 2008273046 A1 (ISHINAGA HIROYUKI et al.) 06.11.2008, paragraphs [0011-0018]; figures. 1-12

Category of the documents cited X: of particular relevance Y: of particular relevance combined with other / s of the same category A: reflects the state of the art O: refers to unwritten disclosure P: published between the priority date and the date of priority submission of the application E: previous document, but published after the date of submission of the application

This report has been prepared • for all claims • for claims no:

Date of realization of the report 13.03.2013

Examiner G. Villarroel Álvaro Page 1/5

REPORT OF THE STATE OF THE TECHNIQUE Application number: 201030156 Minimum documentation sought (classification system followed by classification symbols) B41J Electronic databases consulted during the search (name of the database and, if possible, terms of search used) INVENES, EPODOC State of the Art Report Page 2/5  WRITTEN OPINION Application number: 201030156 Date of Completion of Written Opinion: 03.13.2013 Statement

Novelty (Art. 6.1 LP 11/1986)

Claims Claims 2-12 1 IF NOT

Inventive activity (Art. 8.1 LP11 / 1986)

Claims Claims 1-12 IF NOT

The application is considered to comply with the industrial application requirement. This requirement was evaluated during the formal and technical examination phase of the application (Article 31.2 Law 11/1986).  Opinion Base.- This opinion has been made on the basis of the patent application as published. State of the Art Report Page 3/5  WRITTEN OPINION Application number: 201030156  1. Documents considered.- The documents belonging to the state of the art taken into consideration for the realization of this opinion are listed below.

Document

Publication or Identification Number publication date

D01

US 6116727 A (HAGIWARA YOSHIHIRO) 12.09.2000

D02

EP 0721845 A2 (CANON KK) 17.07.1996

D03

JP 2003145788 A (KONISHIROKU PHOTO IND) 05/21/2003

D04

US 2008084463 A1 (KAWASE JUNYA) 04.10.2008

D05

JP 2005007720 A (CANON FINETECH INC) 13.01.2005

D06

EP 0568419 A1 (IMAJE SA) 03.11.1993

D07

JP 2007331281 A (FUJI XEROX CO LTD) 12.27.2007

D08

US 2008273046 A1 (ISHINAGA HIROYUKI et al.) 06.11.2008

 2. Statement motivated according to articles 29.6 and 29.7 of the Regulations for the execution of Law 11/1986, of March 20, on Patents on novelty and inventive activity; quotes and explanations in support of this statement In the state of the art there are systems for supplying continuous or punctual feed fluids, in which, as in inkjet, certain stable parameters are required in the circuit, in some cases a constant pressure is sought at a point determined of control, or in the same point of exit, being always necessary the regulation of the same. For this there are different solutions, some of which are shown in the state of the art cited. In the case of the application and as claimed in Claim 1, to achieve said objective, two pumps are used, one that carries out the flow of the fluid from the main tank at a certain pressure and another one of suction on the return manifold by exerting a pressure different on the ink that returns to the tank, being claimed that the difference between both pressures remains constant and the set pressure set by the control system is considered. The aforementioned document D01 is an ink supply system in an ink recirculation inkjet printer that includes an ink tank (10), a supply line (30) between the tank and the printheads in which there is a impeller pump (34), and a return line (32) of the ink to the reservoir from the printheads entailed by a suction pump (35). This document details the undesirable fluctuation of pressures at the different points of the circuit and the measures to be taken to maintain a stable situation, which include means of absorbing pressure fluctuations in the ink supply to the heads causing the ink discharge be at constant pressure (see column 1 lines 60 to 65 and column 3 lines 23 to 52). It follows that the first claim of the application lacks novelty and inventive activity. Document D02 consists of a system for removing impurities and bubbles from the power circuit of an inkjet printer. In one of the described embodiments there is a closed circuit consisting of a line that goes from the tank to the injectors, in which there is a fluid delivery pump (9), and an ink collection line from the printheads, in which there is a pump (11) that sucks the fluid and returns it to the main tank. This document mentions the need to adjust the working parameters of the pumps to achieve the desired operation, for which they must approach the data in table 2 included in column 9 of the memory of said document. It is considered that it is implicit in this reasoning, that one of the ways to achieve optimal operation is to keep the pressure difference constant and therefore an expert in the field would easily reach the solution proposed in the application (see column 9, lines 39 to 43). As for dependent claims 2 to 12, it is considered that: the pumps must always be controlled to conform to the desired operation, and since a working pressure on the fluid has to be selected, pressure sensors are necessary. The elements capable of carrying out such controls are multiple and it is considered a design option to incorporate one or the other. The same goes for the choice of the pump that drives or sucks the fluid. The inclusion of pressure compensators is implicit in the regulation. Heating and / or cooling elements in the main tank is an option to choose according to the needs of the system, and the incorporation thereof does not affect the circuit claimed in the claim of the application. Furthermore, if the fluid is considered to be ink, for example in the application of the device to a printhead, it is evident that given the special characteristics of this fluid and its need for adjustment to the injection, its fluidity must be maintained for which the supply temperature has to be controlled which leads directly to the control of the ink conditions in the main tank. See in this regard document D03 which includes means for heating the ink in the tank. State of the Art Report Page 4/5  WRITTEN OPINION Application number: 201030156 As for the conditions of priming and purging, it is obvious that to achieve the beginning of the ink discharge with the consequent filling of the heads and their purging or cleaning, an increase in pressure is convenient, the documents cited D01 and D02 describe systems that are perfectly susceptible to increase pressure for such purposes. Documents D04 to D07 show the state of the art regarding the request containing common elements with the solution provided in it. Due to the above reasons, it is considered that the first claim of the application is not new and that the invention as a whole does not have inventive activity according to articles 6.1 and 8.1 of patent law 11/1986. State of the Art Report Page 5/5