Synchronized drive method and system

Abstract

The present invention relates to a synchronized driving method and system for at least one processing device (1, 1.1, 1.2, 1.3) of a substrate (S) moved by a transport means (10, 11, 12). The method includes: obtaining a position signal (s0) by an encoder (3) that provides a position related to the movement of the substrate (S) and / or the transport means (10, 11, 12) at each point in time; and driving the processing device (1; 1.1, 1.2, 1.3) when the position provided by the position signal (s0) from a positioning point (Pp) over which the substrate (S) has passed takes a predetermined drive position value (V0). The method further includes: measuring the physical and / or kinematic characteristics of the substrate (S) and / or the transport means (10, 11, 12) related to the movement and / or obtaining data relating to those characteristics; and driving the processing device (1; 1.1, 1.2, 1.3) based on the obtained measurements or data, the position signal (s0; s; s'; s A , s B , s C ) and / or drive position value (V0;V;V';V A , V B This is characterized by including correcting Vc).

Description

[Technical Field]

[0001] The present invention relates to a synchronized drive method and system for a substrate processing apparatus such as a panel, wherein the substrate is moved relative to the processing apparatus by a transport means such as a conveyor belt or a roller conveyor.

[0002] These driving methods and systems can synchronize the movement of the substrate with the movement of the substrate when performing drives on the substrate by processing equipment such as digital printing, coating, cutting, marking, or engraving.

[0003] The present invention is particularly applicable to the industry of digital printing of substrates, and further relates to a digital printing press including a synchronized drive system. [Background technology]

[0004] Synchronized drive methods and systems for substrate processing apparatus that use position signals acquired by an encoder are now well known. The position signals provide the position related to the movement of the substrate at each point in time.

[0005] In conveying systems consisting of conveyor belts or roller conveyors, rotary encoders are used. The rotary encoders are coupled functionally to the rotating shaft of the supply rollers of the conveyor belt or the rotating shaft of the roller conveyor. These encoders provide the angular position of their rotating shafts, which is related to the moving position of the substrate and / or the conveying system.

[0006] To drive the processing device in synchronization with the movement of the substrate, the processing device is driven when the position associated with the movement, provided by the position signal from the positioning point through which the substrate passes, takes a predetermined drive position value.

[0007] This drive position value is predetermined according to the distance between the positioning point and the drive point where the processing device should perform its action on the substrate.

[0008] Known synchronized drive methods and systems have the drawback of not achieving optimal accuracy due to delays or precedences to the specified timing of action and / or positional deviations of the action relative to the specified position on the substrate, which can occur when performing synchronized drive on the substrate.

[0009] This drawback is particularly problematic in digital printing methods and systems for substrates that aim to provide high-speed printing with high print resolution.

[0010] Improving print resolution in digital inkjet printers is possible by using print heads that eject smaller volume ink droplets, which can increase the number of pixels per unit print area.

[0011] In single-pass digital inkjet printers, it is also possible to improve print resolution by reducing the printing speed, thereby increasing the number of inkjet droplets ejected per unit length in the direction of substrate movement, and therefore the number of pixels per unit length of print in that direction.

[0012] In this regard, improvement in the synchronization accuracy of known substrate digital inkjet printing methods and systems is desirable. This improvement in synchronization accuracy has a direct impact on improving print resolution. This is because increasing the number of pixels per unit length in the direction of movement of a unit printing area or substrate in order to obtain a higher print resolution at a given printing speed requires higher synchronization accuracy in order to avoid delays in the ejection of print droplets and misalignment of ejected droplets on the substrate and / or ahead of them.

[0013] Patent Document 1 discloses a synchronized drive system for a substrate processing apparatus moved by a conveyor belt for substrate digital printing. To improve synchronization accuracy, the system incorporates an improved encoder compared to a purely rotary encoder, which includes an encoder strip, the encoder strip being moved by two rollers and positioned in contact with the conveyor belt. However, this encoder has the disadvantage of structural complexity when applied to the system.

[0014] Given the described shortcomings or limitations of existing solutions, there is a need for a solution that allows for simple implementation or construction while simultaneously improving the synchronization accuracy provided by known synchronized drive methods and systems for substrate processing equipment, by making minimal modifications to known synchronized drive methods and systems. [Prior art documents] [Patent Documents]

[0015] [Patent Document 1] International Publication No. 2021 / 146595 [Overview of the project] [Problems that the invention aims to solve]

[0016] To achieve this objective and to solve the technical problems discussed to date, and to provide additional advantages as described later, the present invention provides a synchronized driving method for at least one substrate processing apparatus when the substrate is moved by a transport means. [Means for solving the problem]

[0017] The method of the present invention includes acquiring a position signal by an encoder, which provides a position related to the movement of the substrate and / or transport means at each point in time. Furthermore, it includes driving a processing device when the position provided by the position signal from the positioning point through which the substrate passes takes a predetermined drive position value.

[0018] According to the present invention, the method further includes measuring the physical and / or kinematic characteristics of the substrate and / or the means of transport related to the movement and / or obtaining data regarding the characteristics, and correcting the position signal and / or the drive position value based on the measured values or the obtained data in order to drive the processing device.

[0019] Therefore, when the position signal and / or the drive position value is corrected, the processing device is driven when the position from the positioning point provided by the corrected position signal takes the drive position value before correction and / or when the position from the positioning point provided by the position signal before correction takes the corrected drive position value.

[0020] The position of the substrate and / or the means of transport related to the movement is understood to be, in particular, the position of the movable element, in particular the position of the substrate itself, the belt of the conveyor belt, the rotating shaft corresponding to the supply roller of the belt, the rotating shaft of the roller of the roller conveyor, etc., and thereby the position is related to the position of the substrate and / or the means of transport in the movement.

[0021] The position related to the movement is provided by a position signal generated by a position encoder that is known per se. In particular, the encoder is connected so as to function on the movable element where the movement is related to the movement of the substrate and / or the means of transport. The encoder can be, for example, of a linear type or a rotary type.

[0022] For example, when the means of transporting the substrate consists of a conveyor belt or a roller conveyor, a rotary encoder connected so as to function on the rotating shaft of the supply roller of the belt or the conveyor roller can be used, whereby it is possible to obtain a position signal that provides the position related to the movement through the angular position of the rotation of the shaft.

[0023] The pre-correction drive position value is a predetermined value corresponding to the position value provided by the pre-correction position signal from the positioning point, which causes the processing device to be driven when the substrate moves a certain distance from the positioning point.

[0024] Since the position related to movement provided by the position signal generated by the encoder is related to the movement of the substrate and / or the means of transport, the uncorrected drive position value can be obtained from this relationship, which is composed of theoretical functions such as kinematic functions that relate the variation in position provided by the position signal to the distance the substrate travels between two points.

[0025] Unlike known synchronized driving methods, the synchronized driving method of the present invention corrects the position signal and / or drive position value. The correction allows for the consideration of factors that affect the actual movement of the substrate and / or transport means, which are not considered when using the position signal and drive value before correction, as in the prior art, and thus the synchronization accuracy can be improved.

[0026] In this regard, the applicant found that the theoretical relationship between the position related to movement and the actual movement of the substrate and / or means of transport, as a result of the fact that a synchronized driving method is involved and that it determines the drive position value before correction, can constitute a major source of accuracy error. Accuracy error arises as a result of assumptions that need to be formulated in order to define the theoretical relationship.

[0027] Therefore, the applicant noticed that, for example, if the means of transport consists of a conveyor belt and is equipped with a rotary encoder connected to the rotating shaft of the belt's supply roller in a functional manner, there may be both misalignment between the shaft and the encoder and / or between the belt and the roller and / or between the substrate and the belt, as well as deformation of the belt itself, which results in accuracy errors not taken into account by the prior art methods.

[0028] Furthermore, it has been observed that these behaviors depend on the system's usage mechanism, specifically, on factors such as the load on the substrate, the moving speed, and the continuous operating time. Therefore, conventional synchronized drive methods cannot account for such behaviors because the drive position value remains constant. Unlike conventional synchronized drive methods, the present invention can account for these behaviors by dynamically changing the correction of the position signal and / or drive position value during system use.

[0029] In fact, it has been observed that these behaviors become increasingly pronounced as the movement speed and the load on the substrate increase.

[0030] In another aspect, the present invention also relates to a synchronized drive system for at least one processing apparatus for substrates that are moved relative to the apparatus by means of transport. The system is configured to implement the synchronized drive method described herein. In this respect, all matters described in the synchronized drive method of the present invention are applicable to the system, and vice versa.

[0031] The system of the present invention includes means for measuring the physical and / or kinematic properties of a substrate and / or transport means related to movement and / or acquiring data relating to such properties, and a control device, the control device being connected to an encoder for acquiring a position signal, means for detecting the passage of a positioning point of the substrate, means for measuring the physical and / or kinematic properties of a substrate and / or transport means related to movement and / or acquiring data relating to such properties, and the processing device.

[0032] Means for detecting the passage of a positioning point of a substrate include, in particular, at least one detection sensor for detecting the passage of a reference element fixed to the substrate. The reference element can be attached to or incorporated into the substrate itself and, in particular, form part of the substrate. For example, the reference element may consist of the leading edge of the substrate in the direction of movement of the substrate. The detection sensor may be, for example, a contrast detection sensor, which is itself a known method.

[0033] The control device is configured to implement the synchronized driving method of the present invention. The control device includes, in particular, at least one programmable device having FPGA programmable logic, and / or software.

[0034] The processing apparatus used in the present invention can be any type of apparatus used to perform operations on a moving substrate. For example, measuring apparatuses, coating apparatuses, cutting apparatuses, marking apparatuses, engraving apparatuses, digital printing apparatuses, etc., can be considered as processing apparatuses.

[0035] In particular, the present invention applies to an inkjet printer, especially a single-pass inkjet printer, and more specifically to a processing apparatus which is a digital inkjet printing device that constitutes the printer. As described above, a synchronized driving method for a digital inkjet printing device makes it possible to increase the printing speed of the substrate and / or improve the printing resolution.

[0036] A digital printing apparatus includes a plurality of print heads, each having a plurality of ink ejection nozzles arranged in a direction perpendicular to the direction of movement. In particular, the digital printing apparatus is configured to eject droplets with a volume of 20 pL or less, preferably 10 pL or less, and more preferably 5 pL or less, and / or to have a print resolution of 360 dPi or more, preferably 720 dPi or more, and more preferably 1200 dPi or more, in the direction perpendicular to the direction of movement. This resolution is determined by the physical distance between the ejection nozzles arranged in the print heads.

[0037] In another aspect, the present invention also relates to a substrate digital printing machine, which comprises an inkjet printer, in particular a single-pass inkjet printer, transport means for moving a substrate to be printed on by the inkjet printer, an encoder for acquiring a position signal, and detection means for detecting the passage of a position point of the substrate, wherein the inkjet printer comprises a printing apparatus.

[0038] The substrate digital printing machine of the present invention comprises a synchronized drive system for a digital printing machine as described above, for the synchronized drive of a substrate (S) being moved by a transport means.

[0039] This allows the encoder to be used with minimal structural adaptation without modification, thereby improving the synchronization accuracy provided by known synchronized drive methods and systems for substrate processing equipment, while simultaneously enabling a simpler implementation or construction. [Brief explanation of the drawing]

[0040] The following drawings illustrate various practical embodiments of the present invention and do not limit it. [Figure 1] This figure schematically illustrates an embodiment of a synchronized drive method and system according to prior art. This figure is a schematic front view of the system with various components and shows the interactions between the components for carrying out the method. [Figure 2-4] Different general embodiments of the synchronized driving method and system of the present invention are schematically shown. These figures are schematic front views of the system with various components and show the interactions between the components for carrying out the method. [Figure 5-7] Different embodiments of the method and system of the present invention, applicable to the preferred general embodiment shown in Figure 4, are schematically shown. Similarly, these figures are schematic front views of the system with various components, illustrating the interactions between the components for carrying out the method. [Figure 8-9]Different embodiments of the method and system of the present invention are schematically shown, which are also applicable to the embodiment shown in Figure 4 and can be combined with the different embodiments shown in Figures 5-7. Each of these figures shows a schematic plan view of the system with various components. [Figure 10-12] A schematic example of the processing of pre- and post-correction position signals in the method and system of the present invention, applicable to the embodiment shown in Figure 4, is schematically shown. In particular, this exemplary embodiment can be applied in combination with the various embodiments shown in Figures 4 to 9. [Figure 13-15] Another embodiment of the synchronized driving method and system of the present invention, including multiple processing units, is schematically shown. This embodiment constitutes a preferred specific embodiment of the preferred general embodiment shown in Figure 4. These figures are schematic front views of the system with various components and show the interactions between the components for carrying out the method. Figures 13 and 15 relate to different embodiments. [Figure 16] Another embodiment of the synchronized driving method and system of the present invention, including multiple processing units, is schematically shown. This embodiment also constitutes a preferred specific embodiment of the preferred general embodiment shown in Figure 4. Similarly, this figure is a schematic front view of the system with various components, illustrating the interactions between the components for carrying out the method. [Figure 17-18] Different embodiments of the method and system of the present invention, applicable to both the embodiments shown in Figures 13-15 and Figure 16, are schematically shown. Figure 17 shows a schematic plan view of a system with various components. Figure 18 shows a schematic detail view of a processing apparatus consisting of a digital printing device, which is part of a single-pass inkjet printer. [Modes for carrying out the invention]

[0041] Figure 1 shows a known synchronized drive method and system for synchronizing a processing device (1) for a plate-shaped substrate (S), the plate-shaped substrate (S) is moved from left to right by a transport means (10) as shown in the figure.

[0042] The conveying means consists of a conveyor belt (10) including a belt (11) that supports the substrate (S) during movement, and moves within a closed circuit fed by two supply rollers. A drive motor (12) is connected to the shaft of one of the supply rollers (11) of the belt, and an encoder (3) is connected to the shaft of the other supply roller.

[0043] An encoder (3) acquires a position signal (s0), which provides the position of the substrate (S) and / or conveying means (10) related to movement at each point in time, and the encoder (3) consists of the angular position of the shaft of the supply roller of the belt (11) to which it is connected, which is related to the movement of the substrate (S) and the belt (11).

[0044] The processing device (1) is activated at the drive point (Pi) when the reference element (R) of the substrate (S) has passed the positioning point (Pp) and its angular position has reached a predetermined drive position value (V0). The passage of the reference element (R) through the positioning point (Pp) is detected by a detection sensor (2) that detects the reference element (R).

[0045] The angular position is provided by a position signal (s0). The position signal (s0) and the drive position value (V0) are processed by a position acquisition module (4), which is part of the system's control unit.

[0046] The processing unit's position acquisition module (4) is connected to the processing unit (1), the detection sensor (2), and the encoder (3), and the processing unit (1) performs a synchronized driving method for the substrate (S).

[0047] In particular, as shown in Figures 2-4, unlike the prior art, the method according to the present invention includes measuring the physical and / or kinematic characteristics of a substrate (S) and / or conveying means (10) related to movement and / or acquiring data relating to those characteristics, and correcting the position signal (s0;s) and / or drive position value (V0;V) based on the obtained measurements or data in order to drive the processing device (1).

[0048] The uncorrected position signal (s0) obtained from the encoder (3) and / or the uncorrected drive position value (V0) processed by the control device's position acquisition module (4) are corrected to obtain the corrected position signal (s) and / or the corrected drive position value (V). This correction is performed by the position correction module (5), which together with the position acquisition module (4) is part of the system's control device.

[0049] The position acquisition module (4) and position correction module (5) of the control device are connected in such a manner that they act on each other, and are further connected in such a manner that they act on the processing device (1), the detection sensor (2), the encoder (3), and the means for measuring the physical and / or kinematic characteristics of the substrate (S) and / or transport means (10) related to movement (2.1, 2.2; 7) and / or means for acquiring data relating to those characteristics (6), so that the processing device (1) can perform a synchronized driving method of the substrate (S).

[0050] As shown in Figure 2, means for acquiring data relating to the physical and / or kinematic properties of the substrate (S) and / or transporting means (10) related to movement may include, for example, a data logger (6) for storing and / or processing the data.

[0051] As shown in Figure 3, means for measuring the physical and / or kinematic properties of the substrate (S) and / or conveying means (10) related to movement may include, for example, a measuring sensor (7), which is, for example, a speed sensor for the belt (11) and / or substrate (S) as it passes through a measurement point (Pm). Similarly, any type of sensor can be used to measure physical properties such as the weight of the substrate, or other kinematic properties such as the acceleration of the belt and / or substrate (S) at the measurement point (Pm).

[0052] The obtained measurements and / or data are used in the position correction module (5) of the system control unit to correct the position signal (s0;s) or drive position value (V0;V). This correction can be performed, for example, based on a modification or adjustment of the theoretical relationship between the position related to movement obtained by the encoder (3) and the actual moving position of the substrate (S) and / or the belt (11) of the conveying means (10). Therefore, for example, if the belt (11) moves at a constant nominal speed, this speed affects the determination of the drive position value (V0) before correction, and it is possible to correct the drive position value (V0) in real time based on the measured speed of the belt (11) or substrate (S) at the measurement point (Pm).

[0053] Referring to Figures 4-9, the method according to the present invention includes obtaining a value (Δ) of the position variation between a first passing point (Pa) and a second passing point (Ps). The position is provided by an uncorrected position signal (s0) by detecting the passage of a reference element (R;Q, Q') fixed to a substrate (S) and / or transport means (10), particularly a belt (11), over the passing points (Pa, Ps).

[0054] According to the present invention, the correction of the position signal (s0;s) and / or the drive position value (V0;V) is performed based on a variation value (Δ). For example, this variation value (Δ) of position can be used to estimate the speed at which the belt (11) moves between a preceding point (Pa) and a subsequent point (Ps), thereby adjusting a constant nominal speed that determines the drive position value (V0) before correction to obtain the corrected drive position value (V).

[0055] As shown in Figures 4 to 9, means for measuring the physical and / or kinematic properties of the substrate (S) and / or conveying means (10) related to movement may include, for example, at least one sensing sensor (2, 2.1, 2.2; 2.3; 2.4) that detects the passage of reference elements (R; Q; Q') fixed to the belt (11) of the conveyor belt (10) at passing points (Pa, Ps).

[0056] The positional variation (Δ) between the passing points (Pa, Ps) is acquired by a position variation acquisition module (8), which is part of the system control unit. This module (8) is connected to act on the detection sensors (2, 2.1, 2.2, 2.3, 2.4), the position acquisition module (4), and the position correction module (5).

[0057] In particular, as shown in Figure 4, the position change acquisition module (8) acquires the position provided by the position acquisition module (4) by the uncorrected position signal (s0) at the time when the reference elements (R;Q, Q') of the substrate (S) and / or transport means (10), detected by the respective detection sensors (2, 2.1, 2.2, 2.3, 2.4), pass through each passing point (Pa, Ps). The position change acquisition module (8) calculates the change value (Δ) by subtracting the position of the earlier passing point (Pa) from the position of the later passing point (Ps). This change value (Δ) is transmitted to the position correction module (5), and the position signal (s0;s) and / or drive position value (V0;V) are corrected based on it, and this is transmitted to the processing unit (1) for its synchronized drive at the drive point (Pi).

[0058] Preferably, according to the present invention, the correction of the position signal (s0;s) and / or drive position value (V0;V) based on the fluctuation value (Δ) includes obtaining the difference (δ) between a reference fluctuation value (Δ0) of position between passing points (Pa, Ps) and the fluctuation value (Δ) at the measurement position, thereby obtaining the corrected position signal (s) by adding the difference (δ) to the position signal (s0) before correction, and / or obtaining the corrected drive position value (V) by subtracting the difference (δ) from the drive position value (V0) before correction.

[0059] The acquisition of the difference (δ) can be performed in the position variation acquisition module (8), particularly as shown in Figure 4. The difference (δ) between the reference variation value (Δ0) and the variation value (Δ) at the measurement position calculated by module (8) is transmitted to the position correction module (5), and the position signal (s0;s) and / or drive position value (V0;V) are corrected based on this, and transmitted to the processing unit (1) for its synchronized drive at the drive point (Pi).

[0060] In this embodiment of the present invention, the correction of the position signal (s0;s) and / or the drive position value (V0;V) is performed by a difference (δ) that is directly applied (by addition or subtraction) to the position signal (s0) and / or the drive position value (V0) before correction. In addition to its simple implementation, it has the advantage that calculation errors in the process are minimized because it does not require any additional mathematical operations other than addition or subtraction.

[0061] The reference variation value (Δ0) can be theoretically obtained, for example, by a theoretical function, particularly a kinematic function, which relates the variation in position associated with the movement obtained by the uncorrected position signal (s0) to the distance between the passing points (Pa, Ps). In particular, the same theoretical or kinematic function used to calculate the uncorrected drive position value (V0) can be used for the distance between the positioning point and the drive device (1), for example, the drive point (Pi).

[0062] The reference fluctuation value (Δ0) and the drive position value before correction (V0) represent the increasing position value for the ideal behavior of the system (no deviations or deformations that cause errors in synchronization accuracy), and they precisely correspond to the distance between position detection points, i.e., the distance between the preceding point (Pa) and the succeeding point (Ps) for the reference fluctuation value (Δ0), and the distance between the positioning point (Pp) and the drive point (Pi) for the drive position value (V0). In this method, the synchronized drive method and system of the present invention can capture errors that need to be corrected.

[0063] In the context of this invention, the distance between points is generally understood to refer to the distance in the direction of movement or along a straight or curved path of movement. In this view, when two points are generally shown to be no distance or not far apart, it is understood that their projections in the direction of movement or along the path of movement coincide, and in particular the points coincide, i.e., they are the same point. In the illustrated embodiment, the direction of movement is the X-axis direction (see Figures 8, 9, 17, and 18).

[0064] Regarding the arrangement of the passing points (Pa, Ps), it is preferable that the first passing point (Pa) is positioned essentially close to or not far from the positioning point (Pp), and / or the second passing point (Ps) or measurement point (Pm) is positioned essentially close to or not far from the processing device (1; 1.1, 1.2, 1.3), particularly the drive point (Pi).

[0065] Preferably, the first passing point (Pa) is positioned after the positioning point (Pp), and the second passing point (Ps) is positioned before the processing device (1). This allows the correction for each substrate (S) to be performed in real time after the reference element (R) of the substrate has passed the second passing point (Ps) and before it is driven at the drive point (Pi).

[0066] In the context of the present invention, the term "positioning point, measurement point, pass point, or drive point being essentially close" is understood to mean that each measuring means, in particular a detection sensor or processing device, is physically essentially adjacent to each other along the direction of movement or path, and / or the distance between them is not significantly greater than the distance required to give the processing device (1) time to apply the corrected position signal (s) and / or corrected drive position value (V) to the processing device (1) after the reference element (R) of the substrate (S) has passed the subsequent pass point (Ps), due to limitations of the electronic processing of the control device.

[0067] In this regard, referring to Figure 5, the distance (e) between the later passing point (Ps) and the processing device (1), particularly the drive point (Pi), can be less than 10%, preferably less than 5%, and more preferably less than 1%, of the distance (D) between the positioning point (Pp) and the processing device (1) or the drive point (Pi). Similarly, the distance (c) between the positioning point (Pp) and the earlier passing point (Pa) can be less than 10%, preferably less than 5%, and more preferably less than 1%, of the distance (D) between the positioning point (Pp) and the processing device (1) or the drive point (Pi).

[0068] The proximity of the first passing point to the positioning point and the subsequent passing point to the drive point makes it possible to maximize the distance (d) between the passing points (Pa, Ps), and therefore the length of the location of the synchronization error in the direction of movement, which substantially spans the entire length of movement of the substrate (S) from positioning to drive. On the other hand, the coincidence of these points makes it possible to use the same sensing sensor on them.

[0069] Figure 6 shows an embodiment in which the first passing point (Pa) is not far from the positioning point (Pp). Figure 7 shows another embodiment in which the first passing point (Pa) is not far from the second passing point (Ps). The embodiment in Figure 7 can be applied, for example, to a system like the one shown in the illustration in which a point on the belt (11) passes the same point (Pa, s) multiple times. In this view, the invention is applicable to conveyor belts (10) having a belt (11) that moves in a closed circuit as shown in the illustration, or to conveyor belts in which the belt itself moves back and forth passing the same point.

[0070] Figures 8 and 9 show the details of this system in plan view. These figures show the specific arrangement and shape of the reference elements (R;Q, Q').

[0071] In Figure 8, the panel-shaped substrate (S) has a reference element (R) incorporated into its upper surface. This reference element (R) is detected by a detection sensor (2) when it passes a positioning point (Pp), by a detection sensor (2.1) when it passes a previous passing point (Pa), and by a detection sensor (2.2) when it passes a later passing point (Ps).

[0072] For simplification, the drawing shows that the reference element (R) used to detect passage through points (Pa, Ps) is the same as the one used to detect passage through positioning point (Pp). However, this does not exclude cases where these reference elements (R) are different elements or are located at different positions on the substrate (S).

[0073] Preferably, the substrate (S) and / or conveying means (10, 11, 12), particularly the belt (11) of the conveyor belt (10), include a plurality of reference elements (R;Q, Q'). This allows for more frequent correction of the position signal (s0;s) and / or drive position value (V0;V) by obtaining different measurements, particularly different measurements of position related to movement, fluctuation (Δ) or difference (δ), as the number of reference elements (R;Q, Q') present increases.

[0074] More preferably, according to the present invention, a plurality of reference elements (Q;Q') are part of a reference pattern (Q, Q') and are fixed to a substrate (S) and / or a conveying means (10), particularly a belt (11). By arranging the reference elements (Q;Q') that form the reference pattern (Q, Q'), more precise control of the arrangement, dimensions, and spacing of the reference elements constituting the pattern can be enabled, thereby increasing the reliability of the measurement.

[0075] Therefore, for example in Figure 9, in this case, a reference pattern (Q, Q') is incorporated into the upper surface of the belt (11), formed by continuous black (Q) and white (Q') bands extending along its entire length on one side, coinciding with the direction of movement. The reference elements (Q; Q') are the lateral bands, where a color change occurs between white and black. The detection sensors (2.1, 2.2) are contrast detection sensors that detect the color change between white and black, and therefore the reference elements (Q; Q'), when they pass through the passing points (Pa, Ps). In addition, the substrate (S) incorporates a reference element (R) as in the embodiment of Figure 8, which is detected by the detection sensor (2) when it passes through the positioning point (Pp).

[0076] Reference elements and reference patterns applicable to the present invention can have any shape, configuration or arrangement. Reference elements (R, Q, Q') can be fixed, attached or incorporated into the base material (S) itself, in particular by forming a part of the base material (S), or into (or on) the belt (11) of the conveying means (10), particularly the conveyor belt (10).

[0077] In particular, the criterion elements of a criterion pattern can be formed by different motifs, such as consecutive letters or numbers. The selection of different criterion elements in a criterion pattern makes it easier to distinguish them when determining which criterion elements pass through a later passpoint (Ps) after passing through a earlier passpoint (Pa).

[0078] Similarly, in particular, if reference pattern lines (Q;Q') as shown in multiple Figures 9 are arranged parallel to each other, for example on both sides of the belt, it is possible to provide a greater number of measurements per unit time.

[0079] Preferably, the method of the present invention includes storing measurement-related data, for example, using a control device memory. In particular, the method includes storing the position, variation (Δ), and / or difference (δ) related to movement for different substrates (S) and / or different reference elements (R;Q, Q') of the substrates (S) or transport means (10), so that the correction of the position signal (s0;s) and / or drive position value (V0;V) is performed based on the selection of data, particularly in a FIFO ("first-in, first-out") manner. This storage makes it possible to manage the measured or acquired data regardless of the position of the substrate (S).

[0080] According to a preferred embodiment of the present invention, as shown in Figures 10-12, the uncorrected position signal (s0) and the corrected position signal (s) are pulse signals. In this case, the position or position variation (Δ) can be easily obtained by counting the number of pulses (p, p') of the signal (s0, s). The uncorrected pulse signal (s0) is obtained directly from an encoder that encodes the position related to movement. Advantageously, by processing the position signal as a pulse signal (s0; s), it can be used as a clock signal to a processing unit for continuous synchronization, as is done in digital printing.

[0081] Preferably, the corrected position signal (s) is obtained by inserting or suppressing pulses (p, p') in the uncorrected position signal (s0), which allows for easy correction of the position signal (s0;s).

[0082] Therefore, for example, if the detected difference (δ) value is δ=0 (Figures 10a-10b), no correction of the position signal (s0) or drive position value (V0) is necessary, and it means that the position variation between the passing points (Pa, Ps) is ideal or as expected.

[0083] Figure 10a shows the uncorrected pulse signal (p)(s0) obtained from the encoder (3). This is the signal at period T. The point in time when the reference element (R) passes the positioning point (Pp) is indicated as tp. The figure also shows the point in time when the reference element (R) passes the previous point (Pa). The dashed line indicates the signal that has not yet elapsed.

[0084] Figure 10b shows the pulse signal (s0;s). The point in time when the reference element (R) passes the later passpoint (Ps) is shown as ts. As is clear from the figure, two pulses (p) are counted between ta and ts, so the measured variation value (Δ) is Δ=2. Therefore, when the predetermined reference variation value (Δ0) is Δ0=2, δ=Δ0-Δ=0, meaning no pulses are inserted into the position signal and there is no correction.

[0085] The processing unit is driven by a predetermined reference drive value, in this example V0=6, i.e., 6 pulses counting from tp. The point in time when the processing unit (1) is driven at the drive point (Pi) is shown as ti in Figure 10c.

[0086] Similar to the examples shown in Figures 10a to 10c, Figures 11a to 11c show the case where the measurement difference (δ) is δ = -1. In this case, the position signal before correction (s0) is corrected by suppressing the pulse (p) in the position signal after correction (s). As a result, since the drive position value is V0 = 6, the processing unit (1) is driven at a later drive point (Pi) at time ti than in the case shown in Figures 10a to 10c, delaying the execution of the operation and thereby improving the synchronization accuracy.

[0087] Similar to the examples shown in Figures 10a-10c and 11a-11c, Figures 12a-12c show the case where the measurement difference (δ) is δ = +1. The position signal before correction (s0) is corrected by adding a pulse (p) to the position signal after correction (s). As a result, since the drive position value is V0 = 6, the processing unit (1) is driven at time ti at an earlier drive point (Pi) than in the case shown in Figures 10a-10c, improving synchronization accuracy by accelerating the execution of the drive.

[0088] The example described with reference to Figures 10-12 is an example in which the position signal (s0;s) is corrected based on the measured difference (δ) with respect to a predetermined drive position value V0. However, as another embodiment of the present invention, for example, the drive position value (V0;V) may be corrected by simply adding the measured difference (δ) to the drive position value (V0;V) or subtracting the measured difference (δ) from the drive position value (V0;V) without changing the position signal (s0).

[0089] According to a preferred embodiment of the present invention, the position signal (s0;s) and / or the drive position value (V0;V) are corrected when the position from the positioning point (Pp) provided by the position signal (s0) before correction reaches a predetermined corrected position value (Vc). In particular, this position value indicates the point in time when the pulses (p, p') necessary for the correction are inserted into or suppressed from the position signal before correction.

[0090] The corrected position value (Vc) can be selected as a value close to and / or smaller than a predetermined drive position value (V0). The approximation is understood to mean that the absolute value of the difference between the drive position value (V0) and the corrected position value (Vc) is smaller than the drive position value (V0) and is large enough to provide sufficient time to correct the position signal (s0;s) and / or the drive position value (V0;V).

[0091] For example, as can be seen in the case shown in Figure 11, the corrected position value (Vc) is Vc=5 because 5 pulses of the uncorrected position signal (s0) are counted in order to suppress the correction pulse (p). In the case shown in Figure 12, the corrected position value (Vc) is Vc=3 because 3 pulses of the uncorrected position signal (s0) are counted in order to add the correction pulse (p').

[0092] Figures 13-18 show different embodiments of the method and system of the present invention, which include a plurality of processing units (1.1, 1.2, 1.3), each of which has a drive point (Pi, Pi', Pi''; Pii, Piii).

[0093] Figures 17 and 18 show a digital printing press with a synchronized drive system, where the processing unit is a digital inkjet printing machine (1.1, 1.2, 1.3). The digital printing machine is part of an inkjet printer (20), particularly a single-pass inkjet printer. Each digital printing machine (1.1, 1.2, 1.3) comprises a plurality of print heads (21), each print head (21) having a plurality of ink ejection nozzles (22) aligned along a direction (Y axis) perpendicular to the direction of movement (X axis). Each digital printing machine (1.1, 1.2, 1.3) may correspond to one print color. Since the Y-axis resolution of the print head (21) is determined by the distance (g) between the ejection nozzles (22), in the configuration shown in Figure 18, the resolution is determined by half the distance (g) between the nozzles.

[0094] In the embodiments shown in Figures 13-15, the system includes a plurality of sequential processing units (1.1, 1.2, 1.3) associated with a single pair of passing points (Pa, Ps). This configuration allows for optimization of the measuring means and available space, particularly when it is not possible to insert sensing sensors between the processing units (1.1, 1.2, 1.3). According to a preferred embodiment, the processing units (1.1, 1.2, 1.3) are positioned between the passing points (Pa, Ps).

[0095] In the first modified embodiment shown in Figures 13 and 14, the processing units (1.1, 1.2, 1.3) are driven by a common corrected position signal (s') and / or a common corrected drive position value (V'). To this end, the system control unit comprises a position acquisition module (4), a position correction module (9), and a position variation acquisition module (8), as in the case where there is only one processing unit (1). These modules (4, 8, 9) are connected to each other in order to act on measuring means, particularly on detection sensors (2.5, 2.6), and further on the processing units (1.1, 1.2, 1.3) in order to apply the synchronized driving method of the present invention.

[0096] The common correction of the position signals (s0, s') can be corrected, for example, by a ratio so that when the substrate passes through the processing apparatus, the difference (δ) is dispersed along the moving direction and applied. Specifically, based on the measured value of the difference (δ) and the distances (f) between the passing points (Pa, Ps) and between the passing points and the processing apparatus (f1, f2, f3, f4), the number of pulses per unit length is inserted or suppressed. Similarly, the common correction of the drive position values (V0; V’) can be corrected by a ratio so that when the substrate passes through the processing apparatus, the drive position value (V’) is dynamically corrected by dispersing the difference (δ) along the moving direction of the substrate and applying it.

[0097] According to a preferred embodiment of the present invention, the correction by ratio of the position signal (s0, s') and / or the drive position value (V0; V’) is such that the position from the positioning point (Pp) provided by the position signal (s0) before correction is from the position value (V ci ) after a predetermined start correction until the position value (V cf ) after a predetermined final correction is taken. In particular, the range of the position values after this correction (V ci , V cf ) indicates the period during which the pulses (p, p’) required for the correction are inserted into the position signal before correction dispersively or suppressed by the position signal before correction dispersively.

[0098] In the embodiment of the second modification shown in FIGS. 14 and 15, the drives of the processing apparatuses (1.1, 1.2, 1.3) are respectively based on the corrected position signals (s A , s B , s C ) and / or the corrected drive position values (V A , V B , V CThis is carried out by the system control unit, as in the case where there is only one processing unit (1), comprising a position acquisition module (4), a position correction module (9'), and a position change acquisition module (8). These modules (4, 8, 9') are connected to one another, to act on measuring means, in particular to detection sensors (2.5, 2.6), and further to processing units (1.1, 1.2, 1.3), in order to apply the synchronized drive method of the present invention.

[0099] Position signal (s0, s A , s B , s C The correction of the difference (δ) can be performed, for example, by weighted correction, in which the difference (δ) is applied in a timely, weighted manner for each processing device (1.1, 1.2, 1.3) along the direction of movement of the substrate as it passes through the processing devices (1.1, 1.2, 1.3). In particular, a number of pulses are inserted or suppressed based on the measured difference (δ) value and the distance (f) between the passing points (Pa, Ps) and between the passing points and the processing devices (f1, f2, f3, f4).

[0100] According to another embodiment of the present invention shown in Figure 16, the system of the present invention comprises a plurality of consecutive processing units (1.2, 1.3), each associated with a pair of waypoints (Par, Ps'; Par, Ps'') where the forward waypoint (Par) and / or the subsequent waypoints (Ps', Ps'') are shared. In the modified embodiment shown in Figure 16, the first waypoint (Par) is shared for the last two processing units (1.2, 1.3). This configuration makes it possible to insert measuring means, such as detection sensors (2.8, 2.9), into the waypoints (Ps', Ps'') between the processing units (1.2, 1.3), more specifically into a single waypoint, while optimizing the measuring means and available space.

[0101] The system control unit comprises a position acquisition module (4), position correction modules (5.1, 5.2, 5.3), and position variation acquisition modules (8.1, 8.2), similar to the case where there is only one processing unit (1). These modules (4, 5.1, 5.2, 5.3, 8.1, 8.2) are connected to one another, to measuring means, in particular to detection sensors (2.7, 2.8, 2.9), and further to processing units (1.1, 1.2, 1.3), in order to apply the synchronized drive method of the present invention.

[0102] According to a preferred modified embodiment, the preceding passing point (Pa;Par) is positioned essentially in close proximity to, or not far from, a preceding processing unit (1.1) to at least one processing unit (1.2;1.3), and more specifically, in front of the preceding processing unit (1.1). This configuration is realized in both the embodiments shown in Figures 13-15 and Figure 16 by the preceding processing unit (1.1), i.e., the device positioned in front of the other processing units (1.2, 1.3). In this configuration, the subsequent processing units (1.2, 1.3) are driven relative to the preceding processing unit (1.1) regardless of any synchronization errors affecting the preceding processing unit (1.1) itself. [Explanation of Symbols]

[0103] 1 Processing Unit 2 detection sensors 3 Encoders 4. Position acquisition module 5. Position Correction Module 6. Means of acquiring data, data logger 7. Measurement Sensor 8. Position change acquisition module 10 Conveying means 11 belts 12 Drive motor 20 Inkjet Printers 21 Printhead 22 Discharge nozzles p, p' Number of pulses Pa, the passing point ahead Pi drive point Pm measurement point Pp positioning point Ps. A passing point after Q, Q' reference elements R reference element S base material Position signal before s0 correction s Corrected position signal s' Common corrected position signal V0 drive position value before correction Drive position values ​​after V and Vc correction V' Common corrected drive position value Reference variation value at position Δ0 Δ Position variation value δ is the difference between the reference variation value Δ0 and the variation value Δ at the measurement location.

Claims

1. A synchronized driving method for at least one processing device (1, 1.1, 1.2, 1.3) of a substrate (S) moved by a transport means (10, 11, 12), - Using encoder (3), the position signal (s ０ The steps include obtaining the signal, wherein the signal provides a position related to the movement of the substrate (S) and / or the transport means (10, 11, 12) at each point in time, - The position signal (s) from the positioning point (Pp) through which the substrate (S) passes ０ The position provided by ) is a predetermined drive position value (V ０ When the ) is taken, the process involves driving the processing device (1; 1.1, 1.2, 1.3), The synchronized drive method includes, - A step of measuring the physical and / or kinematic properties of the substrate (S) and / or the transport means (10, 11, 12) related to movement, and / or a step of acquiring data relating to those properties, - To drive the processing device (1; 1.1, 1.2, 1.3), based on the acquired measurement values or data, the position signal (s ０ ; s; s'; s Ａ 、s Ｂ 、s Ｃ ) and / or the drive position value (V ０ ; V; V'; V Ａ 、V Ｂ 、Vc) is corrected, and A synchronized driving method characterized by including the following:

2. This includes obtaining a value (Δ) of the positional variation between a preceding passing point (Pa; Par) and a subsequent passing point (Ps), the position being determined by detecting the passage of a reference element (R; Q, Q') fixed to the substrate (S) and / or the transport means (10) through the passing point (Pa, Par; Ps), thereby obtaining the position signal (s) before correction. ０ ) is provided by and thereby the position signal (s ０ ;s;s';s Ａ s Ｂ s Ｃ ) and / or the drive position value (V ０ ;V;V';V Ａ , V Ｂ The synchronized driving method according to claim 1, characterized in that correction of Vc) is performed.

3. Reference variation value of position between the aforementioned passing points (Pa, Par; Ps) (Δ ０ This includes obtaining the difference (δ; δ'; δ'') between the value of variation (Δ) at the measurement position and thereby obtaining the corrected position signal (s; s'; s Ａ s Ｂ s Ｃ ) is the position signal (s) before correction. ０ The drive position value (V) obtained by adding the difference (δ) to the drive position value (V) before correction is equal to the drive position value (V) before correction. ０ The synchronized driving method according to claim 2, characterized in that it is obtained by subtracting the difference (δ) from ).

4. The synchronized driving method according to claim 2 or 3, characterized in that the base material (S) and / or the transport means (10, 11, 12) comprises a plurality of reference elements (R; Q, Q'), and in particular the reference elements (Q; Q') are part of a reference pattern (Q, Q').

5. A synchronized driving method according to any one of claims 2 to 4, characterized in that the earlier passing point (Pa; Par) is located essentially close to or not far from the positioning point (Pp) and / or the later passing point (Ps) is located essentially close to or not far from the processing device (1; 1.1, 1.2, 1.3).

6. A synchronized driving method according to any one of claims 2 to 5, characterized in that the aforementioned passing point (Pa; Par) is positioned after the positioning point (Pp) and / or the subsequent passing point (Ps) is positioned before the processing device (1; 1.1, 1.2, 1.3).

7. The synchronized driving method according to any one of claims 2 to 6, characterized in that the aforementioned passing point (Pa; Par) is located in essentially close proximity to or not far from the preceding processing unit (1.1) with respect to the at least one processing unit (1.2; 1.3), more specifically, is located before the preceding processing unit (1.1).

8. Multiple successive processing units (1.1, 1.2, 1.3) are associated with a single pair of passing points (Pa, Ps), thereby the processing units (1.1, 1.2, 1.3) are controlled by a common corrected position signal (s') and / or a common corrected drive position value (V'), or by their respective corrected position signals (s Ａ s Ｂ s Ｃ ) and / or the respective corrected drive position values ​​(V Ａ , V Ｂ A synchronized driving method according to any one of claims 2 to 7, characterized in that it is driven by Vc, and in particular the processing apparatus (1.1, 1.2, 1.3) is positioned between the passing points (Pa, Ps).

9. A synchronized driving method according to any one of claims 2 to 7, characterized in that a plurality of successive processing units (1.2, 1.3) are associated with their respective pairs of passing points (Par, Ps'; Par, Ps''), and the preceding passing point (Par) and / or the subsequent passing points (Ps', Ps'') are shared.

10. This includes saving the data relating to the measurement, in particular saving the position relating to the movement, the variation value (Δ), and / or the difference (δ; δ'; δ'') for different substrates (S) and / or reference elements (S) or different reference elements (R; Q, Q') of the transport means (10, 11, 12), thereby saving the position signal (s ０ ;s;s';s Ａ s Ｂ s Ｃ ) and / or the drive position value (V ０ ;V;V';V Ａ , V Ｂ The synchronized drive method according to any one of claims 1 to 9, characterized in that the correction of Vc) is performed based on the selection of the data, particularly by the FIFO method.

11. The position signal before correction (s ０ ) and the corrected position signal (s) are pulse signals, particularly the signal (s ０ A synchronized driving method according to any one of claims 1 to 10, characterized in that the position is related to the movement, the fluctuation value (Δ), and / or the difference (δ; δ'; δ'') obtained by counting the number of pulses (p, p') of , s).

12. The corrected position signal (s) is the same as the uncorrected position signal (s) ０ The synchronized driving method according to claim 11, characterized in that it is obtained by inserting or suppressing pulses (p, p') in ).

13. The synchronized drive method according to any one of claims 1 to 12, wherein the processing apparatus (1; 1.1, 1.2, 1.3) is an inkjet printer (20), in particular a digital inkjet printing apparatus (1; 1.1, 1.2, 1.3) which is part of a single-pass inkjet printer, and each digital printing apparatus (1.1, 1.2, 1.3) comprises a plurality of print heads (21), each print head (21) has a plurality of ink ejection nozzles (22) arranged in alignment perpendicular to the direction of movement, and in particular the digital printing apparatus (1.1, 1.2, 1.3) is configured to eject droplets with a volume of 20 pL or less, preferably 10 pL, more preferably 5 pL or less, and / or to provide a print resolution of 360 dPi or more, preferably 720 dPi, more preferably 1200 dPi or more in a direction perpendicular to the direction of movement.

14. A synchronized drive system for at least one processing apparatus (1; 1.1, 1.2, 1.3) of a substrate (S), wherein the substrate (S) is moved relative to the apparatus (1; 1.1, 1.2, 1.3) by a transport means (10, 11, 12), The system is configured to implement the synchronized drive method described in any one of claims 1 to 13. - Means for measuring and / or acquiring data relating to the physical and / or kinematic properties of the substrate (S) and / or the transport means (10, 11, 12) related to movement, - Control devices (4, 5, 8, 9, 9'; 5.1-5.3; 8.1, 8.2) and Includes, Means for measuring and / or acquiring data relating to the physical and / or kinematic properties of the substrate (S) and / or the conveying means (10, 11, 12) related to the movement include, in particular, At least one detection sensor (2; 2.1, 2.2; 2.3; 2.4; 2.5, 2.6; 2.7, 2.8, 2.9) for detecting the passage of reference elements (R; Q, Q') fixed to the substrate (S) and / or the transport means (10, 11, 12), A measuring sensor (7), particularly a speed sensor, for the substrate (S) and / or the transport means (10, 11, 12), and / or Includes a data logger (6), The control device receives a position signal (s ０ A system characterized by being connected to act on an encoder (3) for obtaining a value, means for detecting the passage of the substrate (S) to a positioning point (Pp), means for measuring the physical and / or kinematic characteristics of the substrate (S) and / or the transport means (10, 11, 12) related to movement and / or acquiring data relating to those characteristics, and the processing device (1; 1.1, 1.2, 1.3).

15. A digital printing press for substrate (S), - An inkjet printer (20) including multiple digital printing devices (1.1, 1.2, 1.3), particularly a single-pass inkjet printer, - Transport means (10, 11, 12) for moving the substrate (S) printed by the inkjet printer (20), - Position signals (s) that provide the position of the substrate (S) and / or the transport means (10, 11, 12) related to movement at each point in time. ０ An encoder (3) that obtains ) and - Means for detecting the passage of the positioning point (Pp) of the substrate (S), and in particular means including a detection sensor (2) for detecting the passage of a reference element (R) fixed to the substrate (S) to the positioning point (Pp), A digital printing press comprising a synchronized drive system according to claim 14 for synchronized driving of the digital printing apparatus (1.1, 1.2, 1.3) of the substrate (S) moved by the transport means (10, 11, 12), including the transport means (10, 11, 12).

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