WO2023249615A1

WO2023249615A1 - Printing with a plurality of trays

Info

Publication number: WO2023249615A1
Application number: PCT/US2022/034322
Authority: WO
Inventors: Marina Cantero Lazaro; Diana CANTO ESTANY; Maria Isabel BORRELL BAYONA
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2022-06-21
Filing date: 2022-06-21
Publication date: 2023-12-28

Abstract

According to an example, a printing method (400) comprises receiving a plurality of jobs (410), moving each tray of a plurality of trays towards a print zone (420), determining, for each of the trays, a position of the tray along its printing path (430), defining a combine print job based on the plurality of print jobs and the determined positions (440), and printing the combined print jobs on printing substrates provided on each tray of the plurality of trays (450).

Description

PRINTING WITH A PLURALITY OF TRAYS

BACKGROUND

Printing substrates may be provided on a printing system in a wide variety of ways. In some examples, a tray may be used to hold a printing substrate in a specific configuration to avoid image quality defects during a printing operation carried out on the printing substrate. Then, an advance mechanism may be used to move the tray and the printing substrate towards a print zone. Once the printing operation is performed, the printing substrate may be unloaded from the printing system by releasing the printing substrate from the tray.

BRIEF DESCRIPTION OF DRAWINGS

Features of the present disclosure are illustrated by way of example and are not limited in the following figure(s), in which like numerals indicate like elements, in which:

FIG. 1 shows a printing system comprising a first tray and a second tray movable along parallel printing paths, according to an example of the present disclosure;

FIG. 2A shows a top view of a printing system in a first position, according to an example;

FIG. 2B shows a top view of the printing system of FIG. 2A in a second position;

FIG. 2C shows a top view of the printing system of FIG. 2A and 2B in a third position;

FIG. 3 shows a chart representing a first printing operation and a second printing operation over a period of time, according to an example of the present disclosure;

FIG. 4 shows a flowchart of a method for printing on a plurality of trays, according to an example of the present disclosure; FIG. 5 shows a flowchart of a method for ejecting printing fluid on a plurality of trays based on the length of a swath, according to an example of the present disclosure;

FIG. 6 shows a computer-readable medium comprising instructions to be executed by a processor of a printing system, according to an example of the present disclosure.

DETAILED DESCRIPTION

For simplicity and illustrative purposes, the present disclosure is described by referring mainly to examples. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be readily apparent, however, that the present disclosure may be practiced without limitation to these specific details. In other instances, some methods and structures have not been described in detail so as not to unnecessarily obscure the present disclosure.

Throughout the present disclosure, the terms "a" and "an" are intended to denote at least one of a particular element. As used herein, the term "includes" means includes but not limited to, the term "including" means including but not limited to. The term "based on" means based at least in part on.

Printing systems may print onto a wide variety of printing substrates. In some examples, a printing operation may be carried out by dispensing printing fluid on the printing substrate as the printing substrate moves through a print zone of the printing system. To move the printing substrate across the printing system along a media path direction, printing systems may use an advance mechanism. Examples of advance mechanisms comprise belt-based elements, vacuum-based elements, or actuator-based elements arranged to move a printing substrate (or an intermediate element holding the printing substrate).

During the printing operation, a printhead (or printheads) of the printing system ejects printing fluid on the printing surface. The successive ejection of printing fluid results in a plurality of printing fluid drops being deposited on the printing substrate. As used herein, “printing fluid” refers generally to any substance that can be applied upon a substrate by a printing system during a printing operation, including but not limited to inks, primers and overcoat materials (such as a varnish), water, and solvents other than water.

Among others, a factor that has an impact on the performance of the printing operation is the relative position between the printhead and a top surface of the printing substrate during the printing operation. For instance, if the surface of the printing substrate is non-flattened (e.g., the printing substrate has wrinkles), the ejected drops may not be positioned at the desired locations. Similarly, if the printing substrate is skewed with respect to the media path direction, the deposition of printing fluid may result in dispensing the drops of printing fluid at the wrong locations. In other examples, a printing substrate may have to be in a specific state (e.g., stretched) during the printing operation.

To perform the printing operation under operative conditions, printing systems may use trays as holding elements. These trays may be arranged for fixing the printing substrate in a specific configuration or state. To move the tray across the printing system, the advance mechanism may apply a force to the tray on which the printing substrate is provided. In an example, the tray may include clamping elements to receive a portion of a printing substrate such as an edge (e.g., a leading edge, a trailing edge, or a side edge). In other examples, the tray may be in the form of an elongated element to receive a portion of the printing substrate. In some other examples, the tray may be in the form of a wide surface (e.g., a platen) to receive the printing substrate.

As used herein, the term “tray” will be used to refer to a surface arranged to receive a printing substrate. In some examples, a tray may include at least one element for fixing a position of the printing substrate with respect to the surface of the tray. In some examples, the tray may be in the form of a flat surface on which the printing substrate is to be received. To load the printing substrate on the tray, a loading operation may have to be conducted. Similarly, to unload the printing substrate from the printing tray, an unloading operation may be conducted. These loading and unloading operations may be manually performed by the user or automatically performed by an element of the printing system. However, when a printing substrate is received on a tray of a printing system, the throughput of the printing system may be negatively impacted in exchange of better positioning of the printing substrate within the media path. In particular, the loading and unloading operations of the printing tray increase the idle times of the printing system. Similarly, the use of multiple trays may add some technical challenges which may result in increasing the idle times (for instance, spending more time in the loading and the unloading operations). In some examples, the loading and unloading operation may have to be carried out manually by a user of the printing system. Further, in some examples, the printing system itself may constrain the use of multiple trays because of the relative arrangement between the loading region and the unloading region. For instance, a printing system may include a region that operates both as a loading region and an unloading region.

Disclosed herein are examples of printing methods, printing systems, and computer-readable media including instructions that may be used to reduce the idle times in a printer while effectively performing a printing operation. Hence, different examples of methods, systems, and computer-readable media are described.

As used herein, the term “printing substrate” includes and is not limited to fabrics, textiles, or garments on which a printing fluid is ejected during a printing operation. Printing substrates include both traditional textiles such as a cloth or woven fabric but may also include other substrates for which the printing operations described herein are applicable. In some examples, the printing substrate may be in the form of a cloth (such as a shirt, a t-shirt, pants, or hats), bags and other accessories. In some examples, the printing substrate may have to be provided on the printing tray in a particular way (for instance, stretched) to effectively transfer the printing fluid to the printing substrate.

According to an example, a printing system may comprise a plurality of trays that move along parallel printing paths towards a print zone of the printing system. To perform printing operations, the printing system comprises a printhead over the print zone to eject printing fluid on a printing substrate provided on each tray of the plurality of trays. In some examples, the trays may be loaded at different times and/or may move at different speeds. As a result, the trays may reach the print zone at different times. In order to effectively perform the respective printing operation on each printing substrate, the printing system may comprise a controller to receive position data associated with a position of each of the trays. Based on the position data and the contents of the print jobs to be printed on the printing substrates, the controller may generate combined print data having a width associated with the addition of the individual widths of the trays and the gaps in between the trays. Then, based on the combined print data, the controller may control the printhead of the printing system such that the printhead dispenses printing fluid on portions of the printing substrates that have reached the print zone.

Referring now to FIG. 1 , a printing system 100 comprising a first printing tray 110 and a second printing tray 120 movable along parallel printing paths is shown. The printing system 100 further comprises a printhead 130 positioned over a print zone, wherein the printhead 130 is to eject printing fluid on printing substrates during a printing operation. In an example, a printing substrate may be provided on a printing tray (e.g., the first tray 110 or the second tray 120) by performing a loading operation. The printing system 100 further comprises an advance mechanism 140 to move the first tray 110 and the second tray 120 towards the print zone. In an example, the advance mechanism 130 may move the first tray 110 and the second tray 120 at the same speed.

In FIG. 1 , the printing system 100 further comprises a controller 150. The controller 150 is configured to receive print data associated with printing operations on the printing substrates provided on the trays and to receive position data associated with a position of each of the first tray and the second tray within its printing paths. Based on the print data and the position data, the controller 150 is to generate combined print data. The combined print data may be understood as a combined print job in which the contents of each of the print jobs are distributed. To distribute the print jobs associated with the print data in a single print job, each of the print jobs may be vertically and horizontally arranged based on the relative position of the tray with respect to the print zone and a relative location of the printing path with respect to the other printing paths. Then, the controller 150 is to control the printhead 130 to transfer printing fluid on the printing substrates in accordance with the combined data. As previously explained, the generation of combined print data including each of the printing operations may contribute to reduce the idle times of the printing system 100. In particular, as the tray 110 and the tray 120 are positioned over the print zone, the printhead 130 may dispense printing fluid on each of the printing substrates. In some examples, one of the trays (e.g., the first tray 110) may reach the print zone before the other one (e.g., the second tray 120) and the controller 150 may control the printhead 130 to eject printing fluid over a width associated with the tray is on the print zone (e.g., the first tray 110). However, in other examples, the first tray 1 10 and the second tray 120 may be on the print zone over a period of time. Over the period of time, the controller 150 may control the printhead 130 to dispense printing fluid on multiple printing substrates.

Referring now to FIG. 2A, a top view of a printing system 200A is shown. The printing system 200A comprises a first tray 210 moving in the direction of arrow A and a second tray 220 movable in the direction of arrow B. The dashed lines in the printing system 200A represent the parallel printing paths of the first tray 210 and the second tray 220. The printing system 200A comprises a first loading region 215 for receiving the first tray 210 and a second loading region 225 for receiving the second tray 220. As previously explained, the printing system 200A further comprises a printhead 230 to eject printing fluid on printing substrates and an advance mechanism 240 to move the first tray 210 and the second tray 220 towards a print zone. In FIG. 2A, the print zone is covered by the printhead 230 and is not visible. In addition, the printing system 200A further comprises a controller (not represented in FIG. 2A) for controlling the printhead 230 to print on each of the printing substrates.

In FIG. 2A, a first printing substrate 211 is provided on the first tray 210 and a second printing substrate 221 is provided on the second tray 220, the first tray 210 being closer to the print zone than the second tray 220. Hence, if both trays move at the same speed, the first tray 210 will reach the print zone before the second tray 220. However, in some examples, the first tray 210 and the second tray 220 may move towards the print zone at different speeds before and may move at a common speed while moving over the print zone. In an example, the printing system 200A may comprise a sensor to determine the position of each of the first tray 210 and the second tray 220 within the corresponding printing path and the sensor may generate position data and send the position data to the controller of the printing system 200A. Then, based on the print data associated with the printing operations on the printing substrates and the position data, the controller of the printing system 200A may generate combined print data to be subsequently used for printing on the printing substrates provided on the trays.

According to an example, the printhead 230 may be in the form of a page- wide array configuration in which a plurality of printheads is arranged along a length spanning the width of the first tray 210 and the second tray 220. However, in other examples, the printhead 230 may be in the form of a printhead movable along a scan axis that spans the first tray 210 and the second tray 220, the scan axis being perpendicular to the printing paths represented in dashed lines. In order to reciprocate the printhead along the scan axis, the printing system 200A may further comprise a scanning mechanism configured to move the printhead.

According to other examples, the printing system 200A may comprise an output region to output each of the trays from the printing system 200A. In an example, the printing system 200A may comprise a first output region to output the first tray 210 and a second region to output the second tray 220. In some examples, the controller of the printing system 200A may control the advance mechanism 240 to selectively move at least one of the first tray 210 and the second tray 220 from the loading regions 215 and 225 towards the print zone in response to a loading signal. Then, upon the printhead has printed all the contents of the combined print data associated with a tray, the controller may control the advance mechanism 240 to move the tray to the output region. In an example, the loading signal associated with a tray may be issued in response to a user pressing a button to indicate that the respective tray has been loaded. In other examples, a sensor may be used to determine the presence of a printing substrate on the tray, and the sensor may send the loading signal to the controller upon determining the presence of the printing substrate.

According to some examples, the first loading region 215 and the second loading region 225 may be used as output regions. Accordingly, in the printing system 200A, once the printhead 230 has performed the printing operation on the printing substrates provided on the first tray 210 and the second tray 220, the advance mechanism 240 may move the first tray 210 and the second tray 220 towards the first loading region 215 and the second loading region, respectively.

Referring now to FIG. 2B, a printing system 200B is shown. The printing system 200B shows a second position of the trays of the printing system 200A previously explained in FIG. 2A. For illustrative purposes, the printhead 230 has been omitted such that a print zone 231 is visible. In the second position represented in FIG. 2B, a region of the first tray 210 is over the print zone 231 .

In FIG. 2B, an overlap distance 215 representing a distance along which the printhead of the printing system 200B may print printing fluid on multiple printing substrates at the same time is illustrated. In particular, the overlap distance 215 is defined from the leading edge of the second tray 220 to the trailing edge of the first tray 210 is represented. Hence, over the overlap distance 215, the printhead 230 may eject printing fluid on two different printing substrates.

According to some examples, the controller of the printing systems 200A and 200B may generate combined print data based on print data and position data. As previously described, the print data may be associated with the printing operations to be carried out on the printing substrates and the position data may be associated with a position of the first tray 210 and the second tray 220 within its printing path. In some examples, to generate the combined print data, the controller may arrange the print jobs associated to each of the printing operations within a combined print job based on the position of each of trays along its printing path and a location of the printing path associated to the tray. In some other examples, arranging each print job within the combined print job may comprise distributing the contents of the printing operations along a direction perpendicular to the parallel printing paths based on the locations of the printing paths associated with the trays and distributing the contents of the printing operations along the direction parallel to the parallel printing paths based on the locations of the printing paths associated with the trays.

Referring now to FIG. 2C, a printing system 2000 comprising a printhead 230 movable along a scan axis is shown. The printing system 2000 may correspond to the printing systems 200A and 200B previously explained in FIGs. 2A and 2B. However, in FIG. 20, the printhead is movable along a scan axis that spans the first tray 210 and the second tray 220.

In FIG. 20, the first tray 210 and the second tray 220 are on the print zone 231 . As previously explained, the printhead 230 may print on multiple printing substrates upon both trays are on the print zone 231 . In an example, the printing system 2000 may further comprise a scanning mechanism to move the printhead 230 along the scan axis. As the printhead 230 is moving across a width that spans the first tray 210 and the second tray 220, the printhead 250 may dispense printing fluid.

In the printing system 2000, the printhead 230 is to print an effective area in each of the swaths along the scan axis. The effective area is defined by a width of the printhead 230 and the distance traveled by the printhead during the swath. Accordingly, in FIG. 20, each of the first tray 210 and the second tray 220 has been divided into a plurality of swaths. For example, referring to the first tray 210, the printhead 230 has to perform seven swaths to print on the first substrate provided on the first tray 210. With respect to the second tray 220, the printhead 230 has to perform seven swaths. However, as previously described in FIG. 2B, due to the overlap distance between the first tray 210 and the second tray 220, the printhead 230 has to perform ten swaths to print on the printing substrates provided on the first tray 210 and the second tray 220. In other words, the printhead 230 of the printing system 2000 performs fewer swaths when printing on parallel trays that horizontally overlap over the overlap distance than when trays which do not horizontally overlap over an overlap distance.

In an example, the controller of the printing system 2000 may divide the combined print job resulting from the combined print data into a plurality of swaths. Once the combined print job is divided into the plurality of swaths, the controller may determine a movement range for the printhead 230 in each of the swaths. For instance, in FIG. 20, the plurality of swaths resulting from the combined print job may be separated into a first group of swaths 212a, a second group of swaths 212b, and a third group of swaths 212c. Over the first group of swaths 212a, the controller may determine a movement range in which the printhead 230 is to reciprocate over the first tray 210, thereby avoiding a movement over the length of the scan axis associated to the second tray 220. Over the second group of swaths 212b, the controller may determine a movement range in which the printhead 230 is to reciprocate over the first tray 210 and the second tray such that the printhead 230 dispenses printing fluid on the first tray 210 and the second tray 220. Then, over the third group of swaths 212c, the controller may determine a movement range in which the printhead 230 is to reciprocate over the second tray 220, thereby avoiding a movement over the length of the scan axis associated to the first tray 210. In this fashion, the overall times for printing on the first printing substrate provided on the first tray 210 and the second printing substrate provided on the second tray 220 is reduced. In some examples, the reduction of the distance traveled by the printhead 230 may reduce the servicing operations.

In some examples, the printing system 200C may comprise one or several servicing zones. The servicing zones may be used to perform a servicing operation. In an example, the scanning mechanism of the printing system may move printhead 230 to the servicing zone so as to perform the servicing operation. In an example, the controller of the printing system 200C may control the scanning mechanism to move the printhead to the at least one servicing zone based on the combined print data. During the servicing operation(s), the printhead 230 may dispense an amount of printing fluid on the servicing zone to keep the printhead under operative conditions over the upcoming dispensing operations. In particular, the servicing operation may refresh the printing fluid at the meniscus of the nozzle and the printing fluid within a printing fluid chamber of the printhead. In some examples, the servicing operations may be carried out for all the nozzles included in a printhead. In other examples, the servicing operations may be selectively performed for the nozzles that have exceeded a threshold time associated to a maximum time between subsequent firings of a nozzle. If the threshold time between subsequent firings of a nozzle is exceeded, the printing operation may result in image quality defects.

In some other examples, the controller of the printing system may determine where to perform an upcoming servicing operation based on the movement range of the printhead 230. As previously explained, the printhead 230 of the printing system 200C may selectively move over a portion of the scan axis based on the contents of the combined print data. Hence, based on the location of the printhead 230 with respect to each of the servicing zones, the controller of the printing system may control the scanning mechanism to move the printhead 230 to one of the servicing zones. In an example, the controller may control the scanning mechanism to move the printhead 230 to the closest servicing zone. In other examples, the controller may control the scanning mechanism to move the printhead 230 based on the movement range of the printhead 230 associated to the upcoming swath. For instance, the controller may determine a service zone of the service zones that reduces an overall traveled distance by the printhead 230. In some other examples, the controller may determine a servicing zone of the servicing zones so as to balance the usage of each of the servicing zones.

Referring now to FIG. 3, a chart 300 representing a first printing operation 301 and a second printing operation 302 over a period of time is shown. The first printing operation 301 and the second operation 302 may correspond with, for instance, the printing operations to be carried out on the printing substrates provided on a first tray and a second tray of a printing system. In an example, the printing system may correspond to the printing system 200A, 200B and 200C previously explained in FIGs. 1 and 2A to 2C.

In the chart 300, the first printing operation 301 comprises a first time frame 316 in which the first tray moves from an input region of the printing system towards a print zone of the printing system, a second time frame 317 in which the first tray is moving over the print zone, and a third time frame 318 in which the first tray moves towards an output region of the printing system. Over the first time frame 316 and the third time frame 318, the printhead of the printing system does not dispense printing fluid on the printing substrate provided on the tray. However, over the second time frame 317, the printhead of the printing system dispenses printing fluid on the printing substrate. With respect to the second printing operation 302, the second printing operation 302 comprises a first time frame 326 in which the second tray moves from the input region towards the print zone, a second time frame 327 in which the second tray is moving across the print zone, and a third time frame 318 in which the second tray moves to the output region of the printing system. Over the first time frame 326 and the third time frame 328, the printhead of the printing system does not dispense printing fluid on the printing substrate provided on the second tray. However, over the second time frame 327, the printhead dispenses printing fluid on the printing substrate.

In the chart 300, the second printing operation 302 has a delay 306 with respect to the first printing operation 301 . As a result, the second tray reaches the print zone later than the first tray. However, the first tray and the second tray are on the print zone over an overlap time 307. Over the overlap time 307, the printhead of the printing system may print on both the first tray and the second tray. In an example, the printing system may comprise a scan mechanism to move the printhead along a scan axis, and the printhead may print on the first tray and the second tray during the overlap time 307.

According to some examples, each of the first printing operation 301 and the second printing operation 302 may include additional time frames associated to further actions. For instance, the printing operations 301 and 302 may include additional time frames representing the loading times and/or unloading times.

Although the examples of FIGs. 1 to 3 have been explained in reference to printing systems comprising a first tray and a second tray, it should be understood that the printing system may include additional trays. In an example, the printing system may comprise a plurality of trays movable along a plurality of parallel printing paths. Accordingly, the controller of the printing system may generate the combined print data based on the print data and the position data associated to the plurality of trays.

Referring now to FIG. 4, a method 400 for printing on a plurality of printing substrates movable along parallel printing paths is shown. As previously explained, printing on parallel trays increases the throughput of the printing operation while not increasing the overall costs of the printing system.

At block 410, method 400 comprises receiving a plurality of print jobs, each print job associated to a tray from a plurality of trays. Referring back to the system 200A of FIG. 2A, a first print job may be associated with the first tray 210 and a second print job may be associated with the second tray 220. At block 420, method 400 comprises moving each tray towards a print zone. In an example, an advance mechanism (e.g., advance mechanism 240) may move a tray of the plurality of trays towards the print zone upon the printing substrate has been loaded on the respective tray. For example, the advance mechanism may move a tray towards the print zone upon receiving a loading signal associated with the loading of the tray. At block 430, method 400 comprises determining, for each of the trays, a position of the tray along its printing path. In an example, the position of the trays may be determined using a sensor (e.g., an optical sensor). In other examples, each of the trays may include a transmitter, and the printing system may include a receiver. In some other examples, the trays may include an encoder, and based on the readings of the encoder, a position of a printing tray along its printing path may be determined. Alternatively, the advance mechanism may include a sensor to determine a position of a printing tray along its printing path. Then, at block 440, method 400 comprises defining a combined print job based on the plurality of print jobs and the determined positions of the plurality of trays. As previously explained, the combined print job includes the print jobs associated with each of the trays when considering a position of a tray associated with a print job within its printing path and a relative position of the printing path for the tray with respect to the other printing paths. At block 450, method 400 comprises printing the combined print job on printing substrates provided on each tray of the plurality of trays.

In some examples, defining the combined print job based on the plurality of print jobs and the determined positions of the plurality of trays at block 440 comprises arranging each print job of the plurality of print jobs within the combined print job based on the position of the tray associated to the print jobs along its printing path and a location of the printing path associated to the tray. In some other examples, arranging each print job of the plurality of pint jobs comprises distributing the print jobs along a direction parallel to the parallel printing paths based on the determined positions of the trays and distributing the print jobs along a direction perpendicular to the parallel printing paths based on the locations of the printing paths associated with the trays. In particular, distributing the print jobs along the direction parallel to the parallel printing paths comprises arranging at least two print jobs so as to the at least two print jobs partially overlap (e.g., along the overlap distance 215 in FIG. 2B) in the direction parallel to the printing paths. In some other examples, method 400 further comprises moving a tray at a threshold speed as the tray is moving over the print zone. In some examples, the trays may move at different speeds along a portion of the media path defined from the input region of the printing system to the print zone. Then, once the tray reaches the print zone, the printing tray moves at a threshold speed. As a result, even if the trays of the printing system move at different speeds prior to reaching the print zone, the trays will be moved at the threshold speed during their movement over the print zone so as to effectively perform the printing operation on the plurality of trays.

As previously explained, in some examples, a printing system may comprise a scanning mechanism to move the printhead along a scan axis that spans each of the trays of a plurality of trays of the printing system. Hence, in some examples, block 450 of method 400 may comprise moving a printhead along a scan axis that spans each of the trays and ejecting, with the printhead, printing fluid onto at least two different substrates as the printhead performs a swath along the scan axis. In some other examples, method 400 may further comprise determining printhead servicing zones based on the combined print job. As explained above, a printing system may include multiple servicing zones. In some examples, the servicing zones may be located at each of the ends of the scan axis. In an example, the determination of the servicing zone may be made such that a distance from a current position of the printhead to the selected servicing zone is reduced. In other examples, the servicing zones over the printing operation may be determined such that the distance travelled by the printhead to the servicing zones is reduced over the plurality of swaths associated to the combined print job.

Referring now to FIG. 5, a method 550 for ejecting printing fluid on a plurality of trays based on the length of a swath is shown. In an example, block 450 of the method 400 previously explained in FIG. 4 may correspond to the method 550. At block 551 , method 550 comprises determining a plurality of swaths of a printhead along the scan axis based on the combined print job. At block 552, method 550 comprises determining a swath length along the scan axis in accordance with the determined swaths. In an example, block 552 may comprise determining a width of the contents of the combined print job in each of the swaths of the plurality of swaths and, based on the determined widths, determining the swath length. Then, at block 553, method 550 comprises moving the printhead along the scan axis in accordance with the determined swath lengths. In an example, moving the printhead in accordance with determined swath lengths comprises moving the printhead over a region of the print zone on which the printhead is to eject printing fluid. In other words, instead of moving the printhead along the full length of the scan axis, the printhead selectively moves along a length of the scan axis associated with the contents of the combined print job. Then, at block 554, method 550 comprises ejecting, with the printhead, printing fluid onto at least two different printing substrates as the printhead performs a swath along the scan axis.

According to an example, a computer-readable medium may comprise instructions that, when executed by a processor, may cause the processor to perform a series of operations. In an example, the execution of the instructions may result in the methods 400 and 550 previously explained in FIGs. 4 and 5.

Examples of computer-readable medium comprise any non-transitory tangible medium that can embody, contain, store, or maintain instructions for use by a processor. Computer readable media include, for example, electronic, magnetic, optical, electromagnetic, or semiconductor media. More specific examples of suitable computer readable media include a hard drive, a random-access memory (RAM), a read-only memory (ROM), memory cards and sticks and other portable storage devices.

Referring now to FIG. 6, a computer-readable medium 600 comprising a plurality of instructions 610 to 650 is shown. The instructions, when executed by a processor of a printing system, may cause the processor to perform a series of actions. The computer-readable medium 600 represented in FIG. 6 comprises a first instruction 610, a second instruction 620, a third instruction 630, a fourth instruction 640, and a fifth instruction 650. The first instruction 610, when executed by the processor, causes the processor to receive print jobs to be printed on a first printing substrate. The second instruction 620, when executed by the processor, causes the processor to move each of the first tray and the second tray to a print one along parallel printing paths. As previously explained in FIGs. 1 to 2C, to move the trays, the processor may control an advance mechanism of the printing system so as to move each of the trays towards the print zone. The third instruction 630, when executed by the processor, causes the processor to determine a position of the trays along its printing path. In an example, the position may be determined via a sensor of the printing system. Then, the fourth instruction 640, when executed by the processor, causes the processor to determine combined print data based on the determined positions and the print jobs. In an example, determined combined print data based on the determined positions and the print jobs comprises distributing (vertically and horizontally) each of the print jobs within a combined print job based on the relative locations of the trays within the printing system. The relative locations include both a relative position between the trays in a direction parallel to the media path and the lateral distances between the trays in a direction perpendicular to the media path. Then, the fifth instruction 650, when executed by the processor, causes the processor to control a printhead of the printing system to print on the first printing substrate and the second printing substrate based on the determined combined print data.

In some examples, the computer-readable medium 600 may comprise further instructions to cause the processor to divide the combined print data into a number of swaths and control the printhead to print on the first printing substrate and the second substrate (i.e. , the fifth instruction 650) comprises control a scanning mechanism to move the printhead along a scan axis and control the printhead to eject printing fluid onto the first printing substrate and the second printing substrate in at least one swath of the number of swaths.

As explained throughout the description, printing on trays movable along parallel printing paths reduces the overall times of the printing operation when using trays, thereby increasing the throughput of the printing system. Further, the printing operation on parallel trays reduces the costs associated with additional components (e.g., additional servicing stations, additional printheads, additional carriages, additional advance mechanisms, or additional controllers) without having a negative impact on other factors associated to the performance of the printing system. In addition, when the printing system comprises a scanning mechanism to move the printhead, the movement of the printhead may be associated to the contents of the combined print data, and hence, the overall times for printing on both printing substrates is further reduced and the life of the printhead is improved. What has been described and illustrated herein are examples of the disclosure along with some variations. The terms, descriptions, and figures used herein are set forth by way of illustration only and are not meant as limitations. Many variations are possible within the scope of the disclosure, which is intended to be defined by the following claims (and their equivalents) in which all terms are meant in their broadest reasonable sense unless otherwise indicated.

Claims

CLAIMS What is claimed is:

1 . A printing method comprising: receiving a plurality of print jobs, each print job being associated to a tray from a plurality of trays of a printing system; moving each tray towards a print zone of the printing system, wherein the trays move along parallel printing paths; determining, for each of the trays, a position of the tray along its printing path; defining a combined print job based on the plurality of print jobs and the determined positions of the plurality of trays; and printing the combined print job on printing substrates provided on each tray of the plurality of trays.

2. The method of Claim 1 , wherein defining the combined print job comprises: arranging each print job of the plurality of print jobs within the combined print job based on the position of the tray associated to the print job along its printing path and a location of the printing path associated to the tray.

3. The method of Claim 2, wherein arranging each print job of the plurality of print jobs comprises: distributing the print jobs along a direction parallel to the parallel printing paths based on the determined positions of the trays, and distributing the print jobs along a direction perpendicular to the parallel printing paths based on the locations of the printing paths associated with the trays, wherein distributing the print jobs along the direction parallel to the parallel printing paths comprises arranging at least two print jobs so as to the at least two print jobs share a common portion along the direction parallel to the printing paths.

4. The method of Claim 1 , the method further comprising moving a tray at a threshold speed as the tray is moving over the print zone.

5. The method of Claim 1 , wherein printing the combined print job on the plurality of printing substrates and the determined positions of the plurality of trays comprises: moving a printhead along a scan axis that spans each of the trays, and ejecting, with the printhead, printing fluid onto at least two different printing substrates as the printhead performs a swath along the scan axis.

6. The method of Claim 5, further comprising: determining a plurality of swaths of the printhead along the scan axis based on the combined print job; and determining a swath length for each swath of the plurality of swaths based on the combined print job, wherein moving the printhead along the scan axis comprises moving the printhead in accordance with the determined swath lengths.

7. The method of Claim 5, further comprising determining printhead servicing zones based on the combined print job. A printing system comprising: a first tray and a second tray movable along parallel printing paths; a printhead over a print zone, the printhead to eject printing fluid on printing substrates provided on the first tray and the second tray; an advance mechanism to move the first tray and the second tray towards the print zone; and a controller to: receive print data associated with printing operations on the printing substrates, receive position data associated with a position of each the first tray and second tray within its printing path, generate combined print data based on the print data and the position data, and control the printhead to transfer printing fluid on the printing substrates in accordance with the combined print data. The printing system of Claim 8, further comprising a loading region and an output region, wherein the controller is further to: control the advance mechanism to selectively move at least one of the first tray and the second tray from the loading region towards the print zone in response to a loading signal, and upon the printhead has printed based on the combined print data associated with a tray, control the advance mechanism to selectively move the tray from the print zone to the output region. The printing system of Claim 8, further comprising a sensor to determine the position of each the first tray and second tray within the corresponding printing path, wherein the sensor is to generate the position data and to send the position data to the controller. The printing system of Claim 8, wherein printing system further comprises a scanning mechanism to reciprocate the printhead along a scan axis that spans the first tray and the second tray, wherein in at least one swath, the printhead ejects printing fluid onto the first printing substrate and the second printing substrate. The printing system of Claim 11 , wherein the controller is further to determine a movement range for the scanning mechanism based on the combined print data. The printing system of Claim 11 , wherein the printing system comprises at least one servicing zone, wherein the controller is to control scanning mechanism to move the printhead to the at least one servicing zone based on the combined print data. A computer-readable medium comprising instructions that, when executed by a processor of a printing system, cause the processor to: receive print jobs to be printed on a first printing substrate associated to a first tray and a second printing substrate associated to a second tray; move each of the first tray and the second tray to a print zone along parallel printing paths; determine a position of the trays along its printing path; determine combined print data based on the determined positions and the print jobs; and control a printhead to print on the first printing substrate and the second printing substrate based on the determined combined print data. The computer-readable medium of Claim 14, comprising further instructions to cause the processor to divide the combined print data into a number of swaths, wherein control the printhead to print on the first printing substrate and the second printing substrate comprises: control a scanning mechanism to move the printhead along a scan axis, and control the printhead to eject printing fluid onto the first printing substrate and the second printing substrate in at least one swath of the number of swaths.