Predictive Ink Delivery System and Method of Use

Abstract

A sub - controller (20) for printing, a controller (30), a fluid supply system and an apparatus, and a printing method. A processor - controlled sub - controller (20) is provided for controlling the fluid pressure in one or more droplet ejection heads (60); wherein the controller (30) is configured to receive a droplet ejection head movement curve for each of the one or more droplet ejection heads (60), determine a corresponding induced fluid pressure curve at one or more predetermined positions in each of the one or more droplet ejection heads (60) using the corresponding droplet ejection head movement curve; and generate corresponding pressure correction data for each of the one or more droplet ejection heads (60) based on the corresponding induced fluid pressure curve and a predetermined pressure window to be maintained at the one or more droplet ejection heads (60). A method of printing using one or more droplet ejection heads (60) fluidly connected to a fluid supply system is also provided, wherein the method comprises the steps of: receiving a droplet ejection head movement curve; using the corresponding droplet ejection head movement curve, determining a corresponding induced fluid pressure curve at one or more predetermined positions for each of the one or more droplet ejection heads; and generating a corresponding pressure correction file at the one or more predetermined positions based on the induced fluid pressure curve and the predetermined pressure window.

Description

[0001] The present disclosure relates to a sub - controller for printing, a controller, a fluid supply system and a device for printing, and a method for printing, which may be particularly applicable to applications where a droplet ejection head experiences acceleration / deceleration during printing, or where the droplet ejection head may experience position and orientation changes in multiple directions and degrees of freedom. Such applications can include printing onto large or complex shapes, such as walls and inclined surfaces or 3D objects.

[0002] Background

[0003] Droplet ejection heads are now widely used, whether in more traditional applications such as inkjet printing or in 3D printing or other rapid prototyping technologies. As a result, fluids, such as inks, can have new chemical properties to adhere to new substrates and increase the functionality of the deposited material. Droplet ejection heads have been developed that can be used in industrial applications, such as for direct printing onto substrates such as tiles or textiles, or for forming elements such as color filters in LCD or OLED displays for flat - panel TVs. Such industrial printing techniques using droplet ejection heads allow for short production runs, product customization, and even made - to - order design printing. Thus, it should be understood that droplet ejection heads continue to evolve and specialize to suit new and / or increasingly challenging applications. However, despite many advancements in the field of droplet ejection heads, there is still room for improvement.

[0004] In most applications, some form of fluid supply system is required to deliver fluid to the droplet ejection head. The purpose of the fluid supply system can be limited to replenishing the fluid ejected by the droplet ejection head; more complex systems can control temperature, fluid flow rate, pressure at one or more points inside the droplet ejection head, such as the pressure in the nozzles, thus controlling the position of the meniscus, and so on.

[0005] To ensure the reliable performance of a droplet ejection head, it is desirable to maintain a fluid meniscus within the nozzles of the droplet ejection head to prevent fluid from dripping onto the nozzle plate; to this end, the pressure inside one or more nozzles of the droplet ejection head is maintained below atmospheric pressure. This negative pressure is commonly referred to as back pressure or meniscus pressure. It is also desirable to prevent air from being ingested into the droplet ejection head, which can occur when the back pressure is too low, causing the meniscus to be drawn back into the droplet ejection head. Therefore, the back pressure must be maintained within a window, which is typically determined by: 1) the pressure at which fluid begins to drip onto the nozzle plate, and / or 2) the pressure at which air is ingested through the nozzle. In addition, variations in back pressure within this window may be sufficient to cause undesirable changes in droplet volume and velocity, which can result in observable defects in the printed image on the substrate. Therefore, for reliable and high-quality droplet ejection, it is generally necessary to control the back pressure and keep variations in the back pressure to a minimum (e.g., for the Xaar 1003 printhead, a range of ±2 mbar is specified). Variations in back pressure can originate from a variety of sources, such as changes in the printing task; additionally, in scanning applications where the droplet ejection head moves over a substrate, acceleration and deceleration of the droplet ejection head can also cause variations in back pressure. Therefore, fluid supply systems for droplet ejection heads often include some form of control device or process to respond to and compensate for variations in back pressure. The control can be active (such as a feedback loop) or passive (pressure attenuator / damper, etc.).

[0006] In recent years, there has been increasing interest in printing on more complex and / or larger shapes, such as on three-dimensional objects, or on surfaces such as walls, or on objects such as vehicles, to provide overall coverage, or to decorate and / or customize the surface with images and / or text and / or textures. Traditionally, many of these have been coated using techniques such as spraypainting, but this can be undesirable as large amounts of small particulate fluid are released into the atmosphere, which can be difficult or expensive to handle in order to prevent environmental damage or harm to the operator. Therefore, using a droplet ejection head to print on complex and / or large shapes and surfaces is of interest because it enables printing on a surface in a targeted and controlled manner without releasing large amounts of small particles into the atmosphere. This technique can also reduce the volume requirements of the ink / fluid and thus reduce costs. In addition, the printing technique can allow the simultaneous use of multiple colors or fluid types and permit complex printing jobs to be printed in a limited number of passes.

[0007] For example, printing on large / complicated shapes and surfaces may require the use of industrial robots, such as multi-axis machines or gantry systems or robotic arms. In such applications, the movement of the droplet ejection head may cause large and rapid pressure changes, and existing control methods may not be able to compensate for such pressure changes, making it difficult to prevent the droplet ejection head from dripping or ingesting air, or causing observable defects in the printed image. The object of the present invention is to prevent these drawbacks.

[0008] Figure 10a depicts printing on a substrate 81 using a moving droplet ejection head 60 in a scanning application. For a scanning application, the droplet ejection head 60 moves back and forth only in one direction while the substrate 81 moves under the droplet ejection head in the substrate movement direction 83, which is perpendicular to the droplet ejection head movement direction 84. In operation, before moving ([ Figure 10a (i)) to print the first strip 82(i), the idle droplet ejection head 60 is accelerated to reach a constant printing speed. After completing the first printed strip, the droplet ejection head 60 decelerates and then accelerates in the opposite direction to print the next strip 82(ii), as Figure 10a (ii) shows. The acceleration and deceleration of the droplet ejection head 60 will induce pressure changes due to the inertial forces acting on the fluid, but by accelerating / decelerating in areas outside the printing area (e.g., on either side of the substrate 81), such effects are generally limited.

[0009] Figure 10b depicts printing on a three-dimensional (3D) object 80 using a moving droplet ejection head 60. Similar to Figure 10a the scanning application depicted, the droplet ejection head 60 is accelerated and decelerated to obtain the correct position and speed at various parts of the object 80. In addition, the orientation of the droplet ejection head 60 must be changed to keep the droplets directed towards the surface of the object 80. However, different from the scanning application, such changes in speed and orientation cannot be limited to non-printing areas, and the induced pressure changes need to be compensated during printing in order to maintain the meniscus within the desired position range in the nozzle. For this purpose, as described above, back pressure needs to be controlled.

[0010] Figures 11a - 11c depicts the droplet ejection head 60 in three different positions to explain how the change in the orientation of the droplet ejection head 60 will change the height of the fluid column Δh acting on the fluid at the nozzle plate 61 of the droplet ejection head 60 and thus change the induced pressure 170 (ΔP). In Figure 11a and Figure 11b , the droplet ejection head 60 is rigidly fixed to the sensor 50 / controller 10, while in Figure 11c , the droplet ejection head 60 is capable of rotating relative to the sensor 50 / controller 10 and moving along a curved path 160.Figure 11c The height difference Δh3 therein is shown as an example at a given moment when the droplet ejection head 60 moves along the curved path 160.

[0011] ΔP = ρgΔh, where ρ is the density of the fluid (usually about 1000 kg / m 3 ), and Δh is the height of the fluid column between the nozzle plate 61 and the predetermined position 51 on the sensor 50 / controller 10. If the gravitational acceleration g is taken as 10 m / s 2 , then:

[0012] Figure Δh (m) ΔP (mbar) Figure 11a 0.1 10 Figure 11b 0 0 Figure 11c 0.07 7

[0013] Therefore, it should be understood from the above that a printing strategy involving moving one or more droplet ejection heads 60 to align with a three-dimensional object or a non-horizontal surface may cause an induced pressure change with the variation of the fluid column height Δh; and this will cause a change in the back pressure and may cause the meniscus to move outside its desired position range within the nozzle. Active control of the back pressure is known; for example, in a gravity supply system, the fluid level in the reservoir can be adjusted to control the fluid column height Δh measured between the fluid level in the reservoir and the nozzle plate 61. In other systems, such as Figures 11a - 11c those shown, the height Δh of the important fluid column is the height between the nozzle plate 61 and the predetermined position 51 where the control device 10 is located (as Figures 11a - 11c shown). The pressure can be measured at the predetermined position 51 and adjusted using the control device 10 to maintain the back pressure within the desired range. However, in the case where the droplet ejection head 60 accelerates / decelerates rapidly, or the orientation or direction changes, adjusting the back pressure in response to the measured pressure change may be too slow, which may result in an undesirable change in the droplet ejection performance at best, leading to observable defects in the printed image on the object / substrate, or at worst, causing dripping or air intake. For the latter, if the air cannot be removed from the droplet ejection head, air intake may cause nozzle failure. The present invention aims to provide a more effective pressure prediction and to provide more effective pressure control by using the pressure prediction to eliminate the above defects. The present invention also aims to provide a fluid supply system, a controller, and a device that implement the pressure prediction by a correction method.

[0014] Overview

[0015] Aspects of the present invention are set forth in the appended independent claims, while details of specific embodiments of the present invention are set forth in the appended dependent claims.

[0016] According to a first aspect of the present disclosure, there is provided a processor-controlled sub-controller for controlling the fluid pressure in one or more droplet ejection heads; wherein the sub-controller is configured to:

[0017] ·Receive the droplet ejection head movement curve of each of the one or more droplet ejection heads;

[0018] ·Using the corresponding droplet ejection head movement curve, determine the corresponding induced fluid pressure curve at one or more predetermined positions for each of the one or more droplet ejection heads; and

[0019] ·Based on the corresponding induced fluid pressure curve and the predetermined pressure window to be maintained at the one or more droplet ejection heads, generate corresponding pressure correction data for each of the one or more droplet ejection heads.

[0020] According to a second aspect of the present disclosure, there is provided a processor-controlled controller configured to control a printing process, including controlling the fluid pressure in one or more droplet ejection heads; wherein the controller is configured to:

[0021] ·Receive a printing strategy; and

[0022] ·Using the printing strategy, calculate the corresponding droplet ejection head movement curve for each of the one or more droplet ejection heads.

[0023] According to certain embodiments, there is provided a controller according to the second aspect, the controller further configured to send one or more droplet ejection head movement files to a sub-controller according to the first aspect.

[0024] According to certain other embodiments, there is provided a controller according to the second aspect, the controller further configured to incorporate the functions of a sub-controller according to the first aspect.

[0025] According to a third aspect of the present disclosure, there is provided a fluid supply system including a fluid supply source and a sub-controller according to the first aspect and / or a controller according to the second aspect; wherein the fluid supply source includes a fluid reservoir and one or more fluid supply paths, wherein the one or more fluid supply paths are connected to the fluid supply source at a first end and are configured to be connected to one or more droplet ejection heads at a second end.

[0026] According to certain embodiments, there is provided a fluid supply system according to the third aspect, wherein the fluid supply system further includes one or more control devices located at one or more predetermined positions, and wherein the one or more control devices communicate with the sub-controller according to the first aspect and / or the controller according to the second aspect.

[0027] According to some embodiments, a fluid supply system according to a third aspect is provided, the system further comprising one or more pressure sensors positioned to measure pressure at one or more predetermined locations and in communication with a sub-controller according to the first aspect and / or a controller according to the second aspect so as to provide pressure measurement results to the sub-controller according to the first aspect and / or the controller according to the second aspect.

[0028] According to a fourth aspect of the present disclosure, an apparatus is provided, the apparatus comprising a fluid supply system according to the third aspect; the apparatus further comprising one or more droplet ejecting heads fluidly connected to the fluid supply system at the second end of the one or more fluid supply paths, and one or more moving devices, wherein the moving devices are configured to mount one or more of the one or more droplet ejecting heads thereon.

[0029] According to a fifth aspect of the present disclosure, a printing method is provided, the printing method using one or more droplet ejecting heads fluidly connected to a fluid supply system according to the third aspect or an apparatus according to the fourth aspect; wherein the method comprises the steps of:

[0030] · Receiving a droplet ejecting head movement curve;

[0031] · Using the corresponding droplet ejecting head movement curve, determining a corresponding induced fluid pressure curve at one or more predetermined locations for each of the one or more droplet ejecting heads; and

[0032] · Generating pressure correction data at the one or more predetermined locations based on the induced fluid pressure curve and the predetermined pressure window; and

[0033] · Generating one or more pressure correction files for the one or more predetermined locations based on the pressure correction data.

[0034] According to one embodiment, generating the one or more pressure correction files may further comprise adjusting additional predictable pressure variations in the fluid supply system.

[0035] Alternatively, or additionally, the method may further comprise adjusting the pressure in the fluid supply system if there is a difference between the sensed pressure and the predetermined pressure window. Brief Description of the Drawings

[0037] Figure 1 A processor, a fluid supply system, a moving device, and a droplet ejecting head are depicted, wherein the fluid supply system includes a fluid source, a sub-controller controlled by the processor, and a control device;

[0038] Figure 2a Depicts a droplet ejection head and a sensor / controller moving together in a semi-circular path;

[0039] Figure 2b Is Figure 2a A representative diagram of the induced pressure curve and the pressure regulation curve of the droplet ejection head and the sensor / controller;

[0040] Figure 3 Depicts Figure 1 The process steps of the sub-controller;

[0041] Figure 4 Depicts similar to Figure 1 The processor, fluid supply system, mobile device, and droplet ejection head in, and also includes a control device and a pressure sensor in the fluid reservoir;

[0042] Figure 5 Depicts Figure 4 The process steps of the sub-controller;

[0043] Figure 6 Depicts a fluid supply system allowing through-flow, including a control device, a sensor, a sub-controller, and a main controller, and the fluid supply system allowing through-flow is connected to the droplet ejection head;

[0044] Figure 7 Depicts Figure 6 The process steps of the controller;

[0045] Figure 8 Depicts a device for aligning a 3D object, where the device includes a fluid supply system, a mobile device, and a droplet ejection head connected to the fluid supply system and mounted on the mobile device;

[0046] Figure 9 Depicts a fluid supply system including a control device, a main controller, and a fluid supply system connected to the droplet ejection head;

[0047] Figure 10a Depicts printing on a moving substrate using a moving droplet ejection head;

[0048] Figure 10b Depicts printing on a 3D object using a moving droplet ejection head;

[0049] Figure 11a Depicts a vertically oriented droplet ejection head and a sensor / controller;

[0050] Figure 11b Depicts a horizontally oriented droplet ejection head and a sensor / controller; and

[0051] Figure 11cDepicts a droplet ejection head that rotates independently of the sensor / controller.

[0052] It should be noted that the drawings are not drawn to scale and some features may be shown at exaggerated sizes so that these features are more clearly visible.

[0053] Detailed description of the drawings

[0054] Embodiments and their various implementations will now be described with reference to the drawings. Throughout the following description, like reference numerals are used for like elements where appropriate.

[0055] Figure 1 Depicts a processor 35, a fluid supply system 40, a mobile device 70, and a droplet ejection head 60 mounted on the mobile device 70; wherein the fluid supply system 40 includes a fluid supply source 46, a sub - controller 20 controlled by the processor 35, and a control device 10. The fluid supply source 46 includes a fluid reservoir 41 and a fluid supply path 42; a first end of the fluid supply path 42 is connected to the fluid reservoir 41, and a second end of the fluid supply path 42 is configured to be connected to the droplet ejection head 60 such that in operation, the fluid supply source 46 transports a fluid (such as ink) from the fluid reservoir 41 to the droplet ejection head 60 via the fluid supply path 42, as indicated by arrow 44. It should be understood that in other arrangements, depending on the operational requirements of the fluid supply source, the fluid supply source may include other components such as pumps, dampers, flow meters, flow regulators, additional intermediate reservoirs, valves, heater / coolers, temperature sensors, degassers, etc. The processor 35 is configured to control the sub - controller 20, the droplet ejection head 60, the mobile device 70, and the fluid reservoir 41, and any of its components if present, such as pumps, flow regulators, etc. The processor 35 may also include means for an operator to interact with and adjust the printing process, for example, the processor 35 may be a personal computer or any other suitable device.

[0056] The control device 10 is part of the fluid supply system and is located in or adjacent to the fluid supply path 42 so as to be in fluid connection with the fluid supply path 42, thereby being able to control the pressure in the fluid supply source 46. In this embodiment, the control device 10 is adjacent to the droplet ejection head 60. The sub - controller 20 is configured to control the control device 10. The sub - controller may be a system - on - chip module. The sub - controller may include software elements and / or FPGA logic.

[0057] Now turning to Figure 2a , this figure depicts the droplet ejection head 60 and the control device 10 moving together such that a movement curve can be derived (e.g., calculated) from the semi - circular path 160 along which the droplet ejection head 60 moves. Figure 2bas the Figure 2a droplet ejection head 60 in Figure 2a moves along a semi-circular path 160, a schematic diagram of how the predicted induced fluid pressure curve 170 changes as the height Δh of the fluid column between the nozzle plate 61 and a predetermined position 51 changes over time. Figure 2b Also depicted is a representation of a corrected pressure curve 200, where the induced pressure curve 170 has been corrected to remain within a predetermined pressure window 150.

[0058] As previously mentioned, although there are methods for regulating a fluid supply source in response to measurements of induced pressure changes, in applications where the induced pressure changes rapidly (due to changes in orientation and / or position and / or velocity), such methods may be too slow to respond and thus may not adequately control the induced pressure to maintain the pressure at the nozzle plate 61 within the predetermined pressure window 150, thereby preventing dripping / air ingestion or undesired changes in droplet size and velocity and thus preventing undesired changes in print quality / appearance. This application describes a method of compensating for some / all of the induced pressure changes by determining (predicting) some / all of the induced pressure changes before implementing a printing strategy and then using the predicted induced pressure changes and the predetermined pressure window 150 to calculate a desired pressure compensation scheme. Then, when printing, a device such as Figure 1 depicted can be used such that as the printing strategy is implemented and printing proceeds, the control device 10 adjusts the pressure in the fluid supply source 46 over time to compensate for the predicted pressure changes. This can be done, for example, as Figure 3 shown, Figure 3 depicting a series of process steps 140 that can be executed in the sub-controller 20 when a movement curve 111 is provided to the sub-controller 20 from, for example, the processor 35. Thus, if the droplet ejection head movement curve 111 is provided to the sub-controller 20 by the processor 35, the sub-controller 20 is configured to:

[0059] · Use the droplet ejection head movement curve 111 to determine the induced fluid pressure curve 170 at a predetermined position 51 of the droplet ejection head 60 (step 115); and

[0060] · Based on the induced fluid pressure curve 170 and the predetermined pressure window 150 to be maintained at the droplet ejection head 60, determine pressure correction data for the droplet ejection head 60 (step 120).

[0061] Then, the sub-controller 20 is configured to generate a pressure correction file 180 for the droplet ejection head 60 (step 125), and then provide the pressure correction file 180 to an external device, or directly control the control device 10 using the pressure correction file 180 (step 126), or supply the pressure correction file to the control device 10, which may have an internal controller to adjust and control the pressure in the fluid supply source 46 over time. It may be desirable to locate the sub-controller 20 in close proximity to the control device 10 to ensure that communications sent to / from the control device are transmitted and received on a short time scale.

[0062] It should be understood that the predetermined pressure window 150 may be a meniscus pressure window, whereby the upper limit is the pressure at which the nozzle plate 61 starts to get wet (Pm = 0 mbar), and the lower limit is the pressure at which air is ingested through the nozzle. These limits depend on various factors such as the type of droplet ejection head used, the nozzle size and shape (nozzle layout), and the properties of the fluid used. It should also be understood that if, for example, the pressure fluctuations within this meniscus pressure window are large enough to cause undesirable variations in the droplet size and velocity, and thus in the printed appearance, a predetermined pressure window 150 narrower than the meniscus pressure window may be used.

[0063] It should also be understood that the predetermined position 51 is the position at which control is to be exerted to adjust the fluid pressure so as to maintain the predetermined pressure window 150 at the droplet ejection head 60. It should also be understood that depending on where and how this control is to be exerted, the predetermined position 51 may be at a fixed position or may be at a moving position. For example, the control device 10 may be located on a mobile device 70 and move together with the droplet ejection head 60, or both may move independently of each other, or only the droplet ejection head may move while the position of the control device is fixed. However, as previously mentioned, with reference to Figures 11a - 11c , when determining the induced pressure 170, it is important the relative movement between the predetermined position 51 and the nozzle plate 61 and thus the fluid column height Δh.

[0064] It should be understood that there are multiple ways to determine the pressure correction data. For example, the sub - controller 20 can perform calculations to generate the pressure correction data. This can be calculated using physical laws; alternatively, the sub - controller 20 can use a look - up table or can have a comparator to generate the corresponding pressure correction data. The comparator can compare the determined induced fluid pressure with a predetermined or pre - stored induced pressure and, based on this comparison, output the pressure correction data. Additionally, in the case where the sub - controller uses a look - up table, this can be pre - determined and encoded into the sub - controller 20 or provided to the sub - controller together with the movement curve 111. Alternatively, the sub - controller 20 can use a pre - calibration process to generate the induced pressure curve 170 and / or the pressure correction data. For example, the device can be used to perform one or more calibration runs to generate a look - up table, or the device can be used to use the movement curve 111 to trace the droplet ejection head path in order to measure and record the induced pressure curve 170, compare the induced pressure curve 170 with a predetermined induced pressure curve, and thereby calculate or determine the pressure correction data. As an example, one or more pressure sensors 50 can move along the path that one or more droplet ejection heads will take and measure the pressure changes. It should be understood that when one or more pressure sensors 50 are used in this way to perform such a calibration run, the sensors must be integrated in such a way that the measured pressure represents the pressure in the nozzle. Alternatively, any other suitable method can be used to determine the pressure correction data. Then, the pressure correction data can be used to generate the pressure correction file 180, and the sub - controller 20 can also be configured to use the pressure correction file 180 to control the control device 10 located at the predetermined position 51 in order to dynamically adjust the fluid pressure in part or all of the fluid supply system 40 so as to maintain a predetermined pressure window 150 at the droplet ejection head 60 when the droplet ejection head 60 and the control device 10 are fluidly connected to the fluid supply source 46.

[0065] It should be understood that in many embodiments, it may be convenient to place the control device 10 close to the droplet ejection head 60. However, in other embodiments, as Figure 4 depicted by the dashed line in, it may be appropriate to locate the control device 10b in the fluid reservoir 41; additionally, in some embodiments, it may be desirable to have more than one control device 10, as Figure 4 depicted. For example, in Figure 4Among them, at least one of the control devices is either located near the fluid reservoir 41 and fluidly connected to the fluid reservoir 41, or located within the fluid reservoir 41, and at least one of the control devices 10 is fluidly connected to the fluid supply path 42. In addition, at least one of the control devices 10 is located near the second end of the fluid supply path 42 and is fluidly connected to the second end of the fluid supply path 42. For example, when the pressure correction data can be divided into global data and local data, it may be desirable to have more than one control device 10, so that the fluid pressure in the fluid source 46 can be adjusted by controlling the fluid in the fluid reservoir 41 to globally compensate for the slower changes in the height of the droplet ejection head, while using the control device 10 adjacent to the droplet ejection head 60 to locally control the faster changes (e.g., the orientation of the print head at a given height). In this case, the pressure correction file 180 can be two pressure correction files 180, each control device 10 having one pressure correction file 180. It should also be understood that there may be other sources of pressure variation in the fluid supply system 40, some of which may also be predictable / calculable / measurable / calibratable in advance, such as changes in fluid demand when the print load or print task changes, or changes due to changes in hydrostatic pressure caused by the consumption of the fluid reservoir 41 or changes due to the known performance of one or more pumps in the fluid supply system 40, pressure changes due to pipeline length or viscous damping, etc. The process steps in this case can be similar to Figure 5 the process steps depicted in Figure 5 The process steps in Figure 3 are similar to the process steps in

[0066] Figure 4Also depicted is a fluid supply system 40, which further includes a pressure sensor 50 located near the droplet ejection head 60 to measure the pressure at or near a predetermined location adjacent to the droplet ejection head 60. In addition, the sensor 50 communicates with the sub-controller 20 to provide the pressure measurement results to the sub-controller 20. It should also be understood that in the case where the sensor 50 measures the pressure near rather than at the predetermined location, the sensor or the sub-controller 20 / controller 30 to which the sensor provides the pressure measurement results may adjust the pressure measurement results to account for the location difference. It should be understood that there may be more than one sensor 50 in the fluid supply system 40. For example, there may be one sensor adjacent to each control device 10 present in the system or (where applicable) adjacent to each droplet ejection head 60. In other words, one or more pressure sensors 50 are connected to and controlled by the sub-controller 20 such that the sub-controller 20 is configured to receive one or more pressure measurement results of the pressure in the fluid supply path 42 measured at or near one or more predetermined locations 51. The one or more sensors 50 can check whether one or more control devices 10 are operating as expected and adjust the fluid pressure according to the expectation. Alternatively, one or more sensors 50 can also detect unpredictable pressure fluctuations in the fluid supply system 40. This may be due to the system operating environment, or a similar mobile device, or noise or vibration from any other source of unpredictable pressure fluctuations. In some embodiments, it may be desirable to have a system capable of adjusting for predictable induced pressure changes and unpredictable pressure fluctuations. Therefore, the sub-controller 20 can also be configured to determine one or more response pressure corrections based on the at least one or more pressure fluctuation measurements, the predetermined pressure window 150, and / or the corresponding pressure correction data. Then, the sub-controller 20 can also be configured to use the response pressure corrections to control one or more of the control devices 10 to dynamically adjust the fluid pressure in part or all of the fluid supply system 40 to maintain the predetermined pressure window 150 at the droplet ejection head 60. In this case, it may be desirable to use the sub-controller 20 located in the fluid supply system 40 to ensure a rapid response to any measured pressure fluctuations.

[0067] Now turning to Figure 6 , Figure 6 depicted is a processor 35 and a device 90 for printing, the device 90 including a fluid supply system 40 similar to the foregoing, a droplet ejection head 60 connected to the fluid supply system 40 at a second end of the fluid supply path 42, and a mobile device 70 on which the droplet ejection head 60 is mounted. The main difference from the previously described arrangement is that Figure 6Depicts a flow-through system, which is a fluid supply system 40 including one or more fluid supply paths 42 and one or more fluid return paths 43, such that the fluid return path 43 is connected to the fluid reservoir 41 at its first end and to the droplet ejection head 60 at its second end. Flow-through means that the fluid circulates around the fluid supply system 40 and through the droplet ejection head 60, where a portion of the fluid is withdrawn and ejected from the nozzles in the droplet ejection head 60, and the remaining portion returns to the fluid reservoir 41 as indicated by the return arrow 45. Additionally, it can be seen that the control device 10a positioned adjacent to the droplet ejection head 60 is configured to control the fluid pressure in the fluid supply path 42 and / or the fluid return path 43, such that at least one of the control devices is positioned adjacent to the second end of one of the one or more fluid return paths. Such that the first end of the fluid return path is at the fluid reservoir 41 and the second end is adjacent to the droplet ejection head 60.

[0068] Figure 6 What is also different from the previously described arrangement is that the fluid supply system 40 includes a controller 30 and a sub-controller 20. It should be understood that Figure 6 the controller 30 in Figure 6 performs some of the steps that would be performed in the processor 35 in the previously described arrangement. Thus, for example, in

[0069] · receives a printing strategy from the processor 35; and

[0070] · uses the printing strategy to calculate the droplet ejection head movement curve 111 of the droplet ejection head 60.

[0071] The controller 30 is then configured to send the droplet ejection head movement curve 111 to the sub-controller 20, which can be substantially as described herein. Figure 7 Depicts the main steps of the process:

[0072] · Step 100 - Receive print job data;

[0073] · Step 105 - Use the print job data to determine the printing strategy 106;

[0074] · Step 110 - Determine the movement curve 111;

[0075] · Execute step 140 (as previously referenced in Figure 3 described) to determine the pressure correction file 126; and

[0076] · Step 130 - Execute the print job.

[0077] In Figure 6 device 90, controller 30 sends a movement curve to sub - controller 20 to perform step 140. Once the pressure correction file 126 has been determined by sub - controller 20, controller 30 then performs the printing job. This means that controller 30 can also be configured to control the movement device 70 to move the droplet ejection head 60 according to the droplet ejection head movement curve 111, and the printing strategy can also include a printing command, and controller 30 can also be configured to control the droplet ejection head 60 to execute the printing command. In addition, the printing strategy can include a fluid requirement, and controller 30 can also be configured to control the fluid supply system 40 and / or the fluid reservoir 41 to meet the fluid requirement. It should be understood that the above process is a specific division of the required tasks or steps, and in other embodiments, the balance of tasks can be differently allocated among the processor 35, controller 30, and sub - controller 20.

[0078] Now consider Figure 8 , Figure 8 which depicts processor 35 and device 90. Device 90 is similar to the device described in Figure 6 . For simplicity, the fluid supply system is depicted in a simplified form, with arrows indicating the fluid supply path. In this arrangement, the movement device 70 is schematically shown as a robotic arm 72, where the droplet ejection head 60 is arranged on a bracket 71 on the robotic arm 72 and is shown aligned with a 3D body 80. It can be seen that the use of the robotic arm 72 allows the droplet ejection head to handle the surface or the protrusions and contours on the non - planar surface of the 3D body 80. Thus, device 90 includes a movement device 70 that is configured to be movable in three or more directions and / or orientations. In addition, the movement device 70 is a robotic arm 72 with multiple degrees of freedom. It should be understood that the movement device 70 can be any suitable device or mechanism with multiple degrees of freedom. The main difference from the arrangement depicted in Figure 6 is that in the arrangement of Figure 8 , the sub - controller 20 is omitted, and the controller 30 is configured to incorporate the functions of the sub - controller 20. It should be understood that according to the requirements of a particular embodiment, the fluid supply system 40 can include one or more control devices 10 located at one or more predetermined positions 51, and the control devices 10 can communicate with the sub - controller 20 and / or the controller 30.

[0079] Now turn to Figure 9 , Figure 9 which depicts an arrangement similar to the previous figures; Figure 9Comprises device 90 and processor 35. Device 90 includes features similar to the previous embodiments, but has two droplet ejection heads 60 instead of one droplet ejection head 60, and both of the two droplet ejection heads 60 are mounted on the same moving device 70. It should be understood that in other embodiments, there may be multiple droplet ejection heads 60, and multiple droplet ejection heads 60 can all be mounted on the same moving device 70, or each moving device 70 or robotic arm 72 can have one droplet ejection head 60, or any other arrangement of multiple rows or multiple arrays of droplet ejection heads 60 mounted on one or more moving devices 70, including multiple droplet ejection heads 60 and multiple moving devices 70, where each moving device 70 has more than one droplet ejection head 60. Similar to Figure 8 the same, Figure 9 it has controller 30, but does not have sub - controller 20, so controller 30 will include the functions of sub - controller 20. The controller can also include additional functions. For example, Figure 9 the controller 30 in communicates with the droplet ejection head 60, the moving device 70, and the fluid supply source 41 containing control device 10b to control the droplet ejection head 60, the moving device 70, and the fluid supply source 41 containing control device 10b. There are also three additional control devices: a control device (10a) positioned adjacent to the point where the fluid supply path 42 divides into two sub - paths 42 - 1 and 42 - 2, and control devices (10 - 1, 10 - 2) positioned adjacent to each droplet ejection head 60, where each of the two sub - paths 42 - 1, 42 - 2 connects to the droplet ejection head 60 at their respective second ends. It should be understood that if there are more than two droplet ejection heads 60, the fluid supply path 42 can be similarly divided into more sub - paths, or a separate fluid supply path 42a, 42b, 42c, …, 42n can be provided for each droplet ejection head 60 or each group of droplet ejection heads 60, with a similar fluid supply path separation point in the latter case, such that each droplet ejection head 60 is connected to the fluid supply system 40 and supplied with fluid. Thus, the fluid supply system 40 can include multiple fluid supply paths 42 and multiple control devices 10. Figure 9 depicts one control device (10 - 1 and 10 - 2) for each droplet ejection head 60, but it should be understood that a 1:1 relationship may not be required, and, for example, if the droplet ejection heads 60 are closely grouped together, and / or the droplet ejection heads 60 are in a fixed positional relationship with each other, a single control device 10 can, for example, control several droplet ejection heads 60. One or more control devices 10 can be configured to be controllable so as to dynamically adjust the fluid pressure within part or all of the fluid supply system 40 when operating; where the control device 10 can be controlled by controller 30, as Figure 9 shown, or by a sub - controller, as depicted in other embodiments.

[0080] The arrangements and embodiments described herein can be used in conjunction with methods of printing on vertical or non-planar or three-dimensional surfaces or on complex shapes such as three-dimensional forms or volumes. Such methods can use one or more droplet ejection heads 60 fluidly connected to a fluid supply system 40, as described herein; wherein the method comprises the steps of:

[0081] · Receiving one or more droplet ejection head movement curves 111;

[0082] · Using the respective droplet ejection head movement curves 111 to determine respective induced fluid pressure curves at one or more predetermined positions for each of the one or more droplet ejection heads;

[0083] · Generating pressure correction data at the one or more predetermined positions based on the induced fluid pressure curves and a predetermined pressure window.

[0084] The predetermined pressure window can depend on the droplet ejection head used, the fluid used, the distance and / or angle between the fluid supply system 40 and the droplet ejection head 60, the fluid supply pipe diameter, and any other components that the fluid supply system 40 may include. Additionally, the predetermined pressure window can be a meniscus pressure window or a (possibly narrower) pressure range in order to optimize printing performance. The printing method can also include controlling the fluid pressure within the fluid supply system 40 during operation so as to maintain the predetermined pressure window 150 at the one or more droplet ejection heads 60 while receiving and executing a print command, such that while moving the one or more droplet ejection heads 60 according to the movement curve 111 of the droplet ejection head 60, the one or more droplet ejection heads 60 print an image onto a substrate.

[0085] It should be understood that in the presence of other predictable pressure variations in the fluid supply system 40, the generation of the pressure correction data can thus also include adjusting for additional predictable pressure variations in the fluid supply system 40. Depending on the embodiment, one or more ways of calculating the pressure correction data can be implemented, for example the printing method can include one or more of the following:

[0086] · Generating the pressure correction data includes performing calculations using, for example, formulas and / or physical laws;

[0087] · Generating the pressure correction data includes using a look-up table;

[0088] · Generating the pressure correction data includes using a comparator;

[0089] · Generating the pressure correction data includes performing a pre-print calibration process.

[0090] Once the pressure correction data is determined, the printing method may include controlling the fluid pressure in the fluid supply system 40 by dynamically adjusting the pressure in the fluid supply system 40 during operation using one or more control devices 10 and the pressure correction data, and the pressure correction data may be provided as a pressure correction file.

[0091] The printing method may further include sensing the pressure in the fluid supply system 40 at one or more locations, such as at one or more predetermined locations 51, using one or more sensors 50. This may be performed as a check to determine whether the control device correctly corrects the induced pressure in the fluid supply system, or, additionally / alternatively, the sensor may be used to measure unpredictable pressure fluctuations in the fluid supply system 40, such as due to environmental-induced vibrations or vibrations from components of the device 90. Accordingly, the printing method may further include adjusting the pressure in the fluid supply system 40 if there is a difference between the sensed pressure and a predetermined pressure window.

[0092] It should be understood that in order to determine the droplet ejection head movement curve 111, it may be necessary to determine a printing strategy; this may be calculated / defined in the processor 35. For example, the printing method may include determining or receiving print job data and using the print job data such that determining the printing strategy includes using one or more of a print grid, print resolution, swath profile, number of layers, and stitching. After determining what to print and where to print, the printing method further includes determining a printing strategy, where determining the printing strategy includes calculating the droplet ejection head movement curve 111 of one or more droplet ejection heads 60. It should be understood that such calculation may include calculating the droplet ejection head path, droplet ejection head speed, droplet ejection head acceleration or deceleration, and / or droplet ejection head orientation. Determining the printing strategy may further include determining print commands and fluid requirements.

[0093] The controller and / or sub-controller may be a computing device, a microprocessor, an application specific integrated circuit (ASIC), a system-on-chip module including a processor element and FPGA logic, or any other suitable device that functions to control various components of the fluid supply system and / or the droplet ejection head. The processor may be, for example, a microprocessor or a computer.

[0094] The present disclosure also provides the following clauses:

[0095] 1. A processor-controlled sub-controller for controlling the fluid pressure in one or more droplet ejection heads, wherein the sub-controller is configured to:

[0096] Receive the droplet ejection head movement curve of each of the one or more droplet ejection heads;

[0097] Using the corresponding droplet ejection head movement curve, determine a corresponding induced fluid pressure curve at one or more predetermined positions for each of the one or more droplet ejection heads; and

[0098] Based on the corresponding induced fluid pressure curve and a predetermined pressure window to be maintained at the one or more droplet ejection heads, generate corresponding pressure correction data for each of the one or more droplet ejection heads.

[0099] 2. The sub - controller according to clause 1, wherein the sub - controller is configured to use the corresponding pressure correction data for each of the one or more droplet ejection heads to generate a corresponding pressure correction file.

[0100] 3. The sub - controller according to clause 1 or clause 2, wherein the sub - controller is configured to perform calculations to generate the corresponding pressure correction data, and / or wherein the sub - controller is configured to use a look - up table to generate the corresponding pressure correction data, and / or wherein the sub - controller is configured to use a comparator to generate the corresponding pressure correction data.

[0101] 4. The sub - controller according to any one of the preceding clauses, wherein the sub - controller is configured to use a pre - calibration process to generate the induced fluid pressure curve and / or the corresponding pressure correction data.

[0102] 5. The sub - controller according to any one of the preceding clauses, further configured to use the pressure correction file to control one or more control devices located at the one or more predetermined positions so as to dynamically adjust the fluid pressure in part or all of the fluid supply system when the droplet ejection head and the control device are fluid - connected to the fluid supply system, to maintain the predetermined pressure window at the one or more droplet ejection heads.

[0103] 6. The sub - controller according to any one of the preceding clauses, the sub - controller is further configured to receive one or more pressure measurement results measured at the one or more predetermined positions.

[0104] 7. The sub-controller according to clause 6, wherein the sub-controller is further configured to determine one or more response pressure corrections based on the at least one or more pressure measurements and the predetermined pressure window and / or the corresponding pressure correction data, and wherein the sub-controller is further configured to use the response pressure corrections to control one or more control devices located at the one or more predetermined positions so as to dynamically adjust the fluid pressure in part or all of the fluid supply system when the droplet ejection head and the control device are fluidly connected to the fluid supply system, in order to maintain the predetermined pressure window at the one or more droplet ejection heads.

[0105] 8. A processor-controlled controller configured to control a printing process, including controlling the fluid pressure in one or more droplet ejection heads; wherein the controller is configured to:

[0106] Receive a printing strategy; and

[0107] Use the printing strategy to calculate a corresponding droplet ejection head movement curve for each of the one or more droplet ejection heads.

[0108] 9. The controller according to clause 8, further configured to send the droplet ejection head movement curve to the sub-controller according to any one of clauses 1 to 7, or further configured to incorporate the functionality of the sub-controller according to any one of clauses 1 to 7.

[0109] 10. The controller according to clause 8 or clause 9, further configured to control one or more moving devices so as to move the one or more droplet ejection heads according to the droplet ejection head movement curve, wherein the one or more droplet ejection heads are mounted on the one or more moving devices.

[0110] 11. The controller according to any one of clauses 8 to 10, wherein the printing strategy includes a printing command, and wherein the controller is further configured to control the one or more droplet ejection heads to execute the printing command, and wherein the printing strategy includes a fluid requirement, and wherein the controller is further configured to control a fluid supply source to meet the fluid requirement.

[0111] 12. A fluid supply system comprising a fluid supply source and the sub-controller according to any one of clauses 1 to 7, or the controller according to any one of clauses 8 to 11; wherein the fluid supply source includes a fluid reservoir and one or more fluid supply paths, wherein the one or more fluid supply paths are connected to the fluid reservoir at a first end and are configured to be connected to one or more droplet ejection heads at a second end.

[0112] 13. The fluid supply system according to clause 12, wherein the fluid supply system further comprises one or more control devices located at the one or more predetermined positions, and wherein the one or more control devices communicate with the sub-controller and / or the controller, and wherein the one or more control devices are configured to be controllable so as to dynamically adjust the fluid pressure within part or all of the fluid supply system during operation; wherein the control devices are controlled by the sub-controller and / or the controller.

[0113] 14. The fluid supply system according to clause 12 or clause 13, wherein the fluid supply system is configured as a flow-through system comprising one or more fluid supply paths and one or more fluid return paths.

[0114] 15. The fluid supply system according to any one of the preceding clauses, wherein the one or more predetermined positions include one or more of the following: adjacent to and fluidly connected to the fluid reservoir; and / or located within the fluid reservoir, and / or located within or fluidly connected to one of the one or more fluid supply paths, and / or positioned adjacent to or fluidly connected to the second end of the one or more fluid supply paths, and / or when referring to clause 14, positioned adjacent to or fluidly connected to the second end of the one or more fluid return paths.

[0115] 16. The fluid supply system according to any one of clauses 12 to 15, further comprising one or more pressure sensors positioned to measure the pressure at the one or more predetermined positions in the fluid supply system, and wherein the one or more sensors communicate with the sub-controller and / or the controller so as to provide pressure measurement results to the sub-controller and / or the controller.

[0116] 17. An apparatus comprising the fluid supply system according to any one of clauses 12 to 16, the apparatus further comprising one or more droplet ejection heads fluidly connected to the fluid supply system at the second end of the one or more fluid supply paths, and one or more moving devices, wherein the moving devices are configured to mount one or more of the one or more droplet ejection heads on the moving devices, and wherein the one or more moving devices are configured to be movable in three or more directions and / or orientations.

[0117] 18. A printing method, the printing method using one or more droplet ejection heads, the one or more droplet ejection heads being fluidly connected to a fluid supply system according to any one of clauses 12 to 16, or the method using the apparatus according to clause 17; wherein the method comprises the following steps:

[0118] Receiving a droplet ejection head movement curve;

[0119] Using the corresponding droplet ejection head movement curve, determining a corresponding induced fluid pressure curve at one or more predetermined positions for each of the one or more droplet ejection heads;

[0120] Generating corresponding pressure correction data based on the corresponding induced fluid pressure curve and a predetermined pressure window to be maintained at the one or more droplet ejection heads; and

[0121] Generating a corresponding pressure correction file for the one or more predetermined positions based on the pressure correction data.

[0122] 19. The printing method according to clause 18, wherein generating the pressure correction file further comprises adjusting additional predictable pressure variations in the fluid supply system.

[0123] 20. The printing method according to clause 18 or clause 19, wherein generating the pressure correction data comprises performing calculations, and / or wherein generating the pressure correction data comprises using a look-up table, and / or wherein generating the pressure correction data comprises using a comparator, and / or wherein generating the induced fluid pressure curve and / or the corresponding pressure correction data comprises performing a pre-print calibration process.

[0124] 21. The printing method according to any one of clauses 18 to 20, further comprising controlling the fluid pressure within the fluid supply system during operation so as to maintain the predetermined pressure window.

[0125] 22. The printing method according to clause 21 when referring to clause 13, wherein controlling the fluid pressure within the fluid supply system during operation comprises dynamically adjusting the pressure in the fluid supply system using the one or more control devices and the pressure correction file.

[0126] 23. The printing method according to any one of clauses 18 to 22 when referring to clause 16, wherein the method comprises sensing the pressure in the fluid supply system at the one or more predetermined positions, and wherein the method further comprises adjusting the pressure in the fluid supply system if there is a difference between the sensed pressure and the predetermined pressure window.

[0127] 24. The printing method according to any one of clauses 18 to 23, wherein the method further comprises receiving a printing command and executing the printing command, and further comprises moving the one or more droplet ejection heads according to the droplet ejection head movement curve.

[0128] 25. The printing method according to any one of clauses 18 to 24, wherein calculating the droplet ejection head movement curve for each of the one or more droplet ejection heads comprises one or more of the following: calculating the droplet ejection head path and / or the droplet ejection head speed and / or the droplet ejection head acceleration or deceleration and / or the droplet ejection head orientation.

Claims

1. A processor-controlled sub-controller for controlling fluid pressure in one or more droplet ejection heads, wherein the sub-controller is configured to: Receive a droplet ejection head movement curve for each of the one or more droplet ejection heads; Use the corresponding droplet ejection head movement curve to determine a corresponding induced fluid pressure curve at one or more predetermined positions for each of the one or more droplet ejection heads; Generate corresponding pressure correction data for each of the one or more droplet ejection heads based on the corresponding induced fluid pressure curve and a predetermined pressure window to be maintained at the one or more droplet ejection heads; And Use a pressure correction file to control one or more control devices located at the one or more predetermined positions so as to dynamically adjust the fluid pressure in part or all of the fluid supply system when the one or more droplet ejection heads and the one or more control devices are fluidly connected to a fluid supply system to maintain the predetermined pressure window at the one or more droplet ejection heads, Wherein the one or more predetermined positions are positions at which control is to be exerted to adjust the fluid pressure so as to maintain the predetermined pressure window at each of the one or more droplet ejection heads, and Wherein the upper limit of the predetermined pressure window is the pressure at which fluid begins to drip onto the nozzle plate and the lower limit of the predetermined pressure window is the pressure at which air is ingested through the nozzle.

2. The sub-controller according to claim 1, Wherein, The sub-controller is configured to generate a corresponding pressure correction file using the corresponding pressure correction data for each of the one or more droplet ejection heads.

3. The sub-controller according to claim 1, Wherein, The sub-controller is configured to perform calculations to generate the corresponding pressure correction data, and / or wherein the sub-controller is configured to use a look-up table to generate the corresponding pressure correction data, and / or wherein the sub-controller is configured to use a comparator to generate the corresponding pressure correction data.

4. The sub-controller according to claim 2, Wherein, The sub-controller is configured to perform calculations to generate the corresponding pressure correction data, and / or wherein the sub-controller is configured to use a look-up table to generate the corresponding pressure correction data, and / or wherein the sub-controller is configured to use a comparator to generate the corresponding pressure correction data.

5. The sub-controller according to any one of claims 1-4, Wherein, The sub-controller is configured to use a pre-calibration process to generate the corresponding induced fluid pressure curve and / or the corresponding pressure correction data.

6. The sub-controller according to any one of claims 1-4, the sub-controller is further configured to receive one or more pressure measurement results measured at the one or more predetermined positions.

7. The sub-controller according to claim 6, wherein the sub-controller is further configured to determine one or more response pressure corrections based on the one or more pressure measurements and the predetermined pressure window and / or the corresponding pressure correction data, and wherein, the sub-controller is further configured to use the response pressure corrections to control the one or more control devices located at the one or more predetermined positions so as to dynamically adjust the fluid pressure in part or all of the fluid supply system when the one or more droplet ejector heads and the one or more control devices are fluidly connected to the fluid supply system to maintain the predetermined pressure window at the one or more droplet ejector heads.

8. A processor-controlled controller configured to control a printing process, including controlling the fluid pressure in one or more droplet ejector heads; wherein the controller is configured to: receive a printing strategy; use the printing strategy to calculate a corresponding droplet ejector head movement curve for each of the one or more droplet ejector heads; use the corresponding droplet ejector head movement curve to determine a corresponding induced fluid pressure curve for each of the one or more droplet ejector heads at one or more predetermined positions; generate corresponding pressure correction data based on the corresponding induced fluid pressure curve and the predetermined pressure window to be maintained at the one or more droplet ejector heads; and use a pressure correction file to control one or more control devices located at the one or more predetermined positions so as to dynamically adjust the fluid pressure in part or all of the fluid supply system when the one or more droplet ejector heads and the one or more control devices are fluidly connected to a fluid supply system to maintain the predetermined pressure window at the one or more droplet ejector heads.

9. The controller according to claim 8, further configured to send the droplet ejector head movement curve to the sub-controller according to any one of claims 1 to 7, or further configured to incorporate the functionality of the sub-controller according to any one of claims 1 to 7.

10. The controller according to claim 8, further configured to control one or more moving devices to move the one or more droplet ejector heads according to the droplet ejector head movement curve, wherein the one or more droplet ejector heads are mounted on the one or more moving devices.

11. The controller according to claim 9, further configured to control one or more moving devices to move the one or more droplet ejector heads according to the droplet ejector head movement curve, wherein the one or more droplet ejector heads are mounted on the one or more moving devices.

12. The controller according to any one of claims 8 to 11, wherein, The printing strategy includes a printing command, and wherein the controller is further configured to control the one or more droplet ejection heads to execute the printing command, and wherein the printing strategy includes a fluid requirement, and wherein the controller is further configured to control a fluid supply source to meet the fluid requirement.

13. A fluid supply system comprising a fluid supply source and a sub-controller according to any one of claims 1 to 7, or a controller according to any one of claims 8 to 12; wherein the fluid supply source includes a fluid reservoir and one or more fluid supply paths, wherein the one or more fluid supply paths are connected to the fluid reservoir at a first end and are configured to be connected to one or more droplet ejection heads at a second end.

14. The fluid supply system according to claim 13, wherein, the fluid supply system further includes the one or more control devices at the one or more predetermined locations, and wherein the one or more control devices communicate with the sub-controller and / or the controller, and wherein the one or more control devices are configured to be controllable so as to dynamically adjust the fluid pressure within part or all of the fluid supply system during operation; wherein the one or more control devices are controlled by the sub-controller and / or the controller.

15. The fluid supply system according to claim 13, wherein, the fluid supply system is configured to be a flow-through system including one or more fluid supply paths and one or more fluid return paths.

16. The fluid supply system according to claim 14, wherein, the fluid supply system is configured to be a flow-through system including one or more fluid supply paths and one or more fluid return paths.

17. The fluid supply system according to any one of claims 13 to 16, wherein, the one or more predetermined locations include one or more of the following: adjacent to and fluidly connected to the fluid reservoir; and / or within the fluid reservoir, and / or within or fluidly connected to one of the one or more fluid supply paths, and / or positioned adjacent to or fluidly connected to the second end of the one or more fluid supply paths.

18. The fluid supply system according to claim 15 or 16, wherein, the one or more predetermined locations are positioned adjacent to or fluidly connected to the second end of the one or more fluid return paths.

19. The fluid supply system according to any one of claims 13 to 16, further comprising one or more pressure sensors positioned to measure the pressure at the one or more predetermined locations in the fluid supply system, and wherein, The one or more pressure sensors communicate with the sub-controller and / or the controller to provide pressure measurement results to the sub-controller and / or the controller.

20. An apparatus comprising a fluid supply system according to any one of claims 13 to 19, the apparatus further comprising one or more droplet ejection heads fluidly connected to the fluid supply system at the second end of the one or more fluid supply paths, and one or more moving means, wherein the one or more moving means are configured to mount one or more of the one or more droplet ejection heads on the one or more moving means, and wherein, the one or more moving means are configured to be movable in three or more directions and / or orientations.

21. A printing method using one or more droplet ejection heads fluidly connected to a fluid supply system according to any one of claims 13 to 19, or the printing method using an apparatus according to claim 20 ； wherein the printing method comprises the steps of: receiving a droplet ejection head movement curve; using the corresponding droplet ejection head movement curve to determine a corresponding induced fluid pressure curve at one or more predetermined positions for each of the one or more droplet ejection heads; generating corresponding pressure correction data based on the corresponding induced fluid pressure curve and a predetermined pressure window to be maintained at the one or more droplet ejection heads; and generating a corresponding pressure correction file for the one or more predetermined positions based on the pressure correction data.

22. The printing method according to claim 21, wherein, generating the pressure correction file further comprises adjusting additional predictable pressure variations in the fluid supply system.

23. The printing method according to claim 21, wherein, generating the pressure correction data comprises performing calculations, and / or wherein, generating the pressure correction data comprises using a look-up table, and / or wherein generating the pressure correction data comprises using a comparator, and / or wherein generating the corresponding induced fluid pressure curve and / or the corresponding pressure correction data comprises performing a pre-print calibration process.

24. The printing method according to claim 22, wherein, generating the pressure correction data comprises performing calculations, and / or wherein, generating the pressure correction data comprises using a look-up table, and / or wherein generating the pressure correction data comprises using a comparator, and / or wherein generating the corresponding induced fluid pressure curve and / or the corresponding pressure correction data comprises performing a pre-print calibration process.

25. The printing method according to any one of claims 21 to 24, further comprising controlling the fluid pressure within the fluid supply system during operation to maintain a predetermined pressure window.

26. The printing method according to claim 25, wherein, Controlling the fluid pressure within the fluid supply system during operation includes dynamically adjusting the fluid pressure in the fluid supply system using one or more control devices and the pressure correction file, where the one or more control devices are located at the one or more predetermined positions, and where the one or more control devices communicate with the sub - controller and / or the controller, and where the one or more control devices are configured to be controllable so as to dynamically adjust the fluid pressure within part or all of the fluid supply system during operation; and where the one or more control devices are controlled by the sub - controller and / or the controller.

27. The printing method according to any one of claims 21 - 24, 26, wherein, the fluid supply system further includes one or more pressure sensors, the one or more pressure sensors being positioned to measure the pressure at the one or more predetermined positions in the fluid supply system, and where the one or more pressure sensors communicate with the sub - controller and / or the controller so as to provide pressure measurement results to the sub - controller and / or the controller; the printing method includes sensing the pressure in the fluid supply system at the one or more predetermined positions, and where the printing method further includes adjusting the pressure in the fluid supply system if there is a difference between the sensed pressure and the predetermined pressure window.

28. The printing method according to any one of claims 21 - 24, 26, wherein, the printing method further includes receiving a printing command and executing the printing command, and further includes moving the one or more droplet ejecting heads according to the droplet ejecting head movement curve.

29. The printing method according to any one of claims 21 - 24, 26, wherein, calculating the droplet ejecting head movement curve for each of the one or more droplet ejecting heads includes one or more of the following: calculating the droplet ejecting head path and / or the droplet ejecting head speed and / or the droplet ejecting head acceleration or deceleration and / or the droplet ejecting head orientation.

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