Method for determining layout for imaging relief precursor while taking total imaging time into account

Abstract

To provide a method for determining at least one layout for imaging at least one relief precursor, and a computer program.SOLUTION: A method for determining at least one layout for imaging at least one relief precursor (6) includes the steps of: receiving image job data of at least one image job including at least two raster image files (10 and 20) having at least two different resolutions (R1 and R2) and / or at least two different quality settings which require different image modes; and using processing means to determine at least one layout including image job data for imaging at least one mask layer of at least one relief precursor (6) while taking a total imaging time required for imaging at least one mask layer into account.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The field of the invention relates to methods and computer programs for determining at least one layout for imaging at least one relief precursor. [Background technology]

[0002] When determining the layout of received image job data, which typically includes at least two raster image files for imaging at least one relief precursor, the conventional method is to arrange the raster image files in a scanning manner: the raster image files are first arranged one by one in a first direction; when the space in the first direction of the precursor cannot accommodate the next raster image file, the arrangement moves to a second direction (usually perpendicular to the first direction), and then the raster image files are again arranged one by one in the first direction of the relief precursor.

[0003] However, this method of determining the layout is not entirely satisfactory: a large amount of precursors containing no raster image files may be generated and wasted, and furthermore, it may take a long time to image the mask layer according to the layout thus determined.

[0004] The following patent document 1 discloses a method for determining the layout of a relief precursor. Each time a user selects a new individual slug 11 (each individual slug contains a single image) or changes the slug selection, a cost calculator 14 automatically calculates and displays the calculated cost results, reflecting the changes made by the user. The cost configuration settings 13 include, among other parameters, the full load cost per square inch or millimeter of the plate, the full load cost per square inch for manufacturing each carrier, and the full load cost "per mount" for placing and edging the sealed slug plate. Thus, the invention in patent document 1 helps users arrive at the most cost-effective slug selection optimized for their specific needs, taking into account parameters such as plate cost, labor cost, and other relevant cost-related parameters.

[0005] However, new images are selected manually by the user: the layout decision is not automated. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2009 / 099541 A2 Summary of the Invention

[0007] Embodiments of the present disclosure are based on the insight that if two raster image files have two different resolutions or two different quality settings requiring different image modes, the resolution and / or quality setting introduce another variable that needs to be taken into account compared to when the raster image files placed on the relief precursor have the same resolution and the same quality setting. Furthermore, different layouts are possible even when the same raster image files need to be placed on the same relief precursor, since factors to consider when determining the layout will vary from customer to customer.

[0008] In other situations, one of the factors to consider when determining the layout may be how to reduce the areas of the relief precursor that do not contain imaging pixels, which would normally be wasted. However, because raster image files have a fixed size, knowing which raster image files need to be placed on the relief precursor does not make it obvious how to further reduce the wasted portions of this relief precursor.

[0009] One object of the present disclosure is to optimize the layout of image job data for imaging at least one relief precursor when there are at least two raster image files with different resolutions and / or different quality settings, and one object of the present disclosure is to reduce the portion of the relief precursor that is wasted.

[0010] According to a first aspect, there is provided a method for determining at least one layout for imaging at least one relief precursor, the method comprising the step of receiving image job data for at least one image job comprising at least two raster image files, the at least two raster image files having at least two different resolutions and / or at least two different quality settings requiring different imaging modes, the method further comprising the step of determining, using processing means, the at least one layout comprising the image job data for imaging at least one mask layer of the at least one relief precursor, taking into account a total imaging time required to image the at least one mask layer.

[0011] If there are two raster image files with two different resolutions and / or two different quality settings, the imaging settings will need to be changed and imaging will take longer than if the raster image files only had one resolution. By considering the total imaging time when determining the layout, the layout can reduce the additional time that the complexity of multiple resolutions and / or multiple imaging modes can introduce into the imaging process.

[0012] Typically, the imaging head moves relative to the relief printed precursor in a first direction and a second direction, where the first direction typically corresponds to the imaging direction and the second direction typically corresponds to a row direction perpendicular to the imaging direction.

[0013] Preferably, determining at least one layout includes prioritizing placement of raster image files having the same resolution and / or quality settings in a first direction, typically the imaging direction, over a second direction, typically the row direction. During imaging, the imaging head moves in an imaging direction perpendicular to the row direction, allowing the imaging head to cover an area in a single pass. Depending on the width of the raster image file, multiple passes may be required for imaging. After the first pass of the imaging head, the imaging head moves in the row direction and makes another pass in the imaging direction, and so on.

[0014] In many cases, the relative movement of the imaging heads is faster in one direction than in another, for example, the imaging direction is faster than the row direction, and preferential placement of raster image files in one direction can speed up the imaging of raster image files with the same resolution and / or quality settings.

[0015] As an example, the imaging head may move in a fast imaging direction and a slow imaging direction. For example, using N beams, pixel locations of N tracks may be written simultaneously as the N beams move in the fast imaging direction. The beams extend adjacent to each other in the slow imaging direction. Examples of fast imaging directions and slow imaging directions are described in WO 2018 / 228922 A1, where the fast imaging direction corresponds to the imaging direction (e.g., the direction of rotation of the drum to which the precursor is fixed) and the slow imaging direction corresponds to the row direction. Imaging of at least one relief precursor can be accelerated by prioritizing placement of raster image files with the same resolution in the fast imaging direction over the slow imaging direction.

[0016] Optionally, the imaging direction is approximately perpendicular to the row direction.

[0017] Optionally, the imaging direction is circumferential to the drum to which the relief precursor is fixed during imaging.

[0018] In this case, the row direction may be the length direction of the drum perpendicular to the circumferential direction.

[0019] Optionally, determining the at least one layout further comprises considering the number of relief precursors required to fit the image job data.

[0020] In some cases, it may be desirable to control the number of relief precursors for an image job(s). By considering the number of relief precursors required to fit the image job data, the raster image file may be organized based on relief precursors such that the total number of relief precursors imaged is limited or reduced.

[0021] Optionally, determining at least one layout further comprises considering whether raster image files of the same relief precursor belong to the same image job of said at least one image job.

[0022] Even with the same imaging setup, the same imaging head may produce slightly different imaging results for two different relief precursors, especially if there is a long interval between imaging the two relief precursors. If an area imaged from a portion of a first relief precursor needs to be overlaid with an area imaged from a portion of a second relief precursor, for example, if a portion of the first relief precursor corresponds to a first color and a portion of the second relief precursor corresponds to a second color and are combined to create a color image, these two areas may not necessarily be aligned. This potential misalignment can be mitigated by placing raster image files belonging to the same image job on the same relief precursor.

[0023] Furthermore, image job management is simplified. For example, an image job may include two raster image files, with the first raster image file placed on a first precursor and the second raster image file placed on a second precursor. The two precursors may have a long production interval: the first precursor may be imaged, exposed, washed, and dried before 10:00 AM, while the second precursor may not be imaged until 6:00 PM that same day. The customer must wait for the second precursor to complete the image job, even if the rest of the image job is already ready much earlier. By considering whether raster image files of the same relief precursor belong to the same image job, image jobs can be completed more quickly. Furthermore, it becomes easier to track the unfinished portions of an image job.

[0024] Optionally, determining at least one layout further comprises considering an image job priority or deadline of said at least one image job.

[0025] It may be necessary to increase the priority of an image job so that it can be completed before a certain deadline. By taking the priority or deadline into consideration, the corresponding image job data may be placed on a relief precursor that will be imaged sooner.

[0026] Optionally, determining the at least one layout comprises minimizing a total imaging time required to image the at least one mask layer.

[0027] This reduces the total imaging time and accelerates the manufacturing process of the relief precursor.

[0028] Optionally, determining the at least one layout includes using weighting factors for two or more of the following criteria: total imaging time required to image at least one mask layer, number of relief precursors required to match image job data, whether raster image files of the same relief precursor belong to the same image job of said at least one image job, image job priority or deadline of said at least one image job, or amount of waste.

[0029] The step of determining the layout may be influenced by various, sometimes conflicting priorities. For example, if image job priority takes precedence, the total imaging time may be longer and the number of relief precursors may be greater. As another example, raster image files of the same relief precursor may not belong to the same image job if it is desired to reduce the number of relief precursors needed to fit the image job data.

[0030] Furthermore, even with the same image job data, two different customers may want to obtain different layouts, where the first customer may want to minimize the total imaging time and the second customer may want to minimize the number of relief precursors to fit the image job data.

[0031] By using weighting factors for these criteria, different priorities can be taken into account, allowing the layout of the same image job to be flexibly adjusted to suit different requirements.

[0032] Optionally, at least one of the weighting factors is input to the processing means through a user interface.

[0033] Thanks to this feature, the user can indicate to the processing means how much weight he wants to give to a particular criterion. For example, he can indicate that 90% of the consideration should be given to the number of relief precursors, and the remaining 10% should be equally divided among the remaining criteria. As another example, he may indicate that 50% of the consideration should be given to the total imaging time, 20% to the number of relief precursors, 20% to the arrangement of raster image files of the same relief precursor that belong to the same image job, and the remaining 10% to the priority or deadline of a particular image job.

[0034] Optionally, the method further comprises: determining at least two different possible layouts including all of the image job data; assigning a score to each determined layout taking into account weighting factors; selecting the layout with the highest score as the layout for imaging at least one mask layer.

[0035] Therefore, layouts can be selected according to different requirements, which are reflected in different sets of weighting factors. By selecting the layout with the highest score, the priority indicated in the weighting factors is taken into account.

[0036] For example, each score corresponds to a set of weighting factors.

[0037] According to a preferred embodiment, the method further comprises the step of modifying the algorithm used to determine the at least one layout.

[0038] The method may use a neural network. For example, modifying the algorithm may include training the neural network and modifying the weights of the neural network. During training, the neural network is provided with a raster image file and a set of weighting factors as input. The neural network outputs a score determined based on the raster image file and the set of weighting factors. The neural network is trained to output at least one layout with the highest score(s) for the raster image file and the set of weighting factors. This may include, for example, adjusting the weights of the neural network to maximize the score from the same raster image file and set of weighting factors. This process may then be repeated for both the same raster image file but different sets of weighting factors and for different raster image files.

[0039] In this way, an improved neural network can be obtained.

[0040] Optionally, a step is performed to determine that the total area occupied by the raster image files of each mask layer of at least one relief precursor is at least 60%, preferably more than 70%, more preferably more than 80% of the total printable area of ​​said mask layer.

[0041] This feature reduces the waste of at least one relief precursor.

[0042] Optionally, determining the layout further comprises placing raster image files of the same image job onto at least one predetermined relief precursor.

[0043] In this way, additional variations that may be introduced by the relief precursor can be taken into account and / or mitigated, thus reducing inconsistencies in imaging results of the same image job.

[0044] Optionally, the at least one predetermined relief precursor is a single relief precursor or multiple consecutive relief precursors imaged one after the other.

[0045] Placing raster image files of the same image job onto the same relief precursor or onto multiple consecutive relief precursors ensures that variations in the imaging results from different relief precursors are reduced or even eliminated.

[0046] Optionally, the method further includes imaging the mask layer of the relief precursor according to the determined layout, wherein a first imaging head emitting at least one first ablation beam according to a first imaging mode and a second imaging head emitting at least one second ablation beam according to a second imaging mode different from the first imaging mode simultaneously image the mask layer of the relief precursor.

[0047] Simultaneous imaging of the mask layer with two different modes of ablation beams can reduce the time required to image two regions with two different resolutions and / or two different quality settings, e.g., by eliminating the need to image a region with a first resolution in a first pass and then image a region with a second resolution different from the first resolution in a subsequent pass.

[0048] Additionally or alternatively, the method further includes a step of imaging a mask layer of the relief precursor according to the determined layout, wherein an imaging head emitting at least one first ablation beam according to a first imaging mode and / or having a first size corresponding to a first resolution images the mask layer in a first pass of the imaging head, and wherein the same imaging head emitting at least one second ablation beam according to a second imaging mode different from the first imaging mode and / or having a second size corresponding to a second resolution different from the first resolution images the mask layer in a second pass of the imaging head.

[0049] Optionally, the imaging mode defines at least one of the following characteristics: intensity of the at least one laser beam; shape of the at least one laser beam; size of the at least one laser beam.

[0050] According to a second aspect, there is provided a method of determining at least one layout for imaging at least one relief precursor, the method comprising receiving image job data for at least one image job comprising a plurality of raster image files, the method further comprising determining, using processing means, at least one layout comprising image job data for imaging at least one mask layer of the at least one relief precursor, the method comprising overlaying at least two of the plurality of raster image files in the layout.

[0051] When determining the layout for imaging at least one mask layer, two raster image files are typically separated and do not overlap. However, not all of the area of ​​the relief printing plate corresponding to the raster image file is used for printing. By overlapping at least two of the raster image files in the layout, the area of ​​the relief printing plate not used for printing can be reduced.

[0052] Optionally, the image job data comprises at least two display raster image files having cutting marks associated with the at least two raster image files, and the method includes taking the cutting marks into account to determine the at least one layout. Preferably, the cutting marks of the at least two display raster image files are prevented from intersecting with each other. In another embodiment, the cutting marks are directly included in the at least two raster image files. Also, in such an embodiment, the determining step may be performed such that the cutting marks do not intersect with each other.

[0053] To separate two image zones of a relief printing plate, cutting marks and / or cutting contours can be used. A cutting mark is typically a line or a set of lines used to manually separate image zones. A cutting contour is often an irregular shape that must be followed by an automatic cutting table. By taking the cutting marks into account, the cutting marks can be kept clear and subsequent separation can be performed efficiently.

[0054] Optionally, the cutting marks are included in the raster image file.

[0055] Optionally, the at least two raster image files comprise a first raster image file having at least one image area comprising imaging pixels and at least one non-image area comprising non-imaging pixels, and a second raster image file having at least one image area comprising imaging pixels, and the step of overlapping the at least two raster image files in the layout includes a step of avoiding overlap between the image area of ​​the second raster image file and the non-image area of ​​the first raster image file.

[0056] Portions of the relief printing plate corresponding to the non-image areas may undergo additional processing during manufacture of the relief plate, for example, the non-image areas correspond to locations where the image zones of the relief printing plate (corresponding to the image areas of the first and second raster image files) become separated after the relief precursor has been exposed and developed. By not overlapping the image areas of a raster image file with the non-image areas of another raster image file, potential damage to the image zones of the relief printing plate corresponding to the image areas can be avoided.

[0057] According to one embodiment, there is a non-functioning region outside of the image region I. The non-functioning region includes imaging pixels added to the region. The non-functioning region may be as disclosed, for example, in European Patent Application No. 23199621.6 (European Publication No. EP4345596A1). According to some embodiments, determining the layout includes considering imaging pixels added to the non-functioning region, where different fill patterns of pixels in the non-functioning region may result in different amounts of total imaging time, etc.

[0058] Optionally, the cutting marks are located at edges of image areas of said at least one image area.

[0059] Optionally, the at least one non-image region comprises a boundary surrounding the at least one image region.

[0060] By keeping the image regions of the raster image files away from the border, it can be ensured that the image regions of the two raster image files remain a constant distance from each other even after they overlap.

[0061] Optionally, the boundary comprises a cutting mark.

[0062] By not placing the image areas of the raster image files within the boundaries, potential damage to the image areas of the relief printing plate corresponding to the image areas of the first and second raster image files can be avoided when the image areas are subsequently separated.

[0063] Optionally, the second raster image file has at least one non-image area comprising non-imaged pixels. In the method, overlaying the at least two raster image files in the layout includes overlaying the non-image area of ​​the second raster image file with the non-image area of ​​the first raster image file.

[0064] In this way, more image area can be placed on the printed area of ​​the relief precursor, thereby reducing wasted portions of the relief precursor.

[0065] Optionally, at least one non-image area comprises a mark, such as the cutting mark described above. Additionally or alternatively, the mark comprises a registration mark and / or an attachment mark. The registration mark is, for example, as disclosed in patent application WO 2019 / 038400 A1. The registration mark is used, for example, by the cutting table to check how the plate is positioned on the cutting table. For example, the attachment mark ensures that the relief plate is positioned in the correct position on the printing cylinder, for example, in such a way that its position matches the positions of other plates of different colors.

[0066] Alternatively, the marks may be included in the image area and printed onto the print medium or written onto the relief plate precursor before, during or after cutting the relief plate precursor.

[0067] The present disclosure further relates to a flexographic printing plate obtained by the above-mentioned method.

[0068] The present disclosure further relates to a computer program or computer program product comprising computer executable instructions for controlling the above-mentioned method when said program is run on a computer.

[0069] The present disclosure further relates to a digital data storage medium encoded with a machine-executable program of instructions for performing any of the steps of the above-described methods.

[0070] Any feature of the first aspect can be combined with any feature of the second aspect.

[0071] The accompanying drawings are used to illustrate presently preferred, non-limiting, exemplary embodiments of the method, control module, and system of the present invention. These and other advantages of the features and objects of the present invention will become more apparent and the invention will be better understood from the following detailed description read in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0072] [Figure 1] FIG. 1 shows the layout of a raster image file of a relief plate precursor according to a method according to a first embodiment of the present disclosure, the layout being determined taking into account the total imaging time required to image at least one mask layer. [Figure 2] FIG. 2 shows the layout of a raster image file of a relief plate precursor according to a method according to a first aspect of the present disclosure, where the layout is determined taking into account the number of relief precursors required to fit the image job data. [Figure 3] FIG. 3 is a diagram showing a variation of the layout of FIG. 2. [Figure 4] FIG. 2 shows the layout of raster image files of two relief plate precursors according to a method according to a first aspect of the present disclosure, where the layout is determined taking into account the priority or deadline of the image job. [Figure 5] FIG. 1 shows the layout of raster image files of two relief precursors according to a method according to a first aspect of the present disclosure, where the layout is determined taking into account whether the raster image files of the same relief precursor belong to the same image job. [Figure 6]FIG. 10 shows the layout of a raster image file of a relief plate precursor according to a method according to a second aspect of the present disclosure. [Figure 7] FIG. 10 shows the layout of a raster image file of a relief plate precursor according to a method according to a second embodiment, illustrating the avoidance of overlapping cutting marks. [Figure 8] FIG. 10 is a diagram showing the layout of raster image files of a relief plate precursor according to a method according to a second aspect of the present disclosure, including avoiding overlap of image areas of the second raster image file with boundaries of image areas of the first raster image file, the boundaries representing non-image areas of the first raster image file. [Figure 9] A diagram showing the layout of raster image files of a relief plate precursor according to a method according to a second aspect of the present disclosure, including overlapping boundaries of the first and second raster image files, the boundaries representing a portion of the non-image area. [Figure 10] 1 illustrates an exemplary embodiment of a system according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0073] Flexography or letterpress printing is a technique commonly used for high volume printing. A flexography or letterpress printing plate is a relief plate with printing elements, usually called reliefs or dots, protruding above non-printing elements to produce an image on a recording medium such as paper, cardboard, film, foil, laminate, etc. Cylindrical printing plates or sleeves may also be used.

[0074] There are various methods for producing flexographic printing plate precursors. According to conventional methods, flexographic printing plate precursors are produced from a multilayer substrate comprising a backing layer and one or more photohardening layers (also called photosensitive layers). These photohardening layers are imaged by exposure to electromagnetic radiation through a mask layer containing image information, or by direct and selective exposure to light, for example by scanning the plate to transfer the image information and obtain a relief plate.

[0075] The relief precursor may be, for example, a digital relief precursor or an analog relief precursor. In the case of a digital relief precursor, the mask layer is an integral layer of the precursor, and imaging of the mask layer forms an ablation layer, whereas in the case of an analog relief precursor, the mask layer is typically a separate layer, such as a film, with radiation-transparent and radiation-opaque areas, which is attached to the relief precursor before exposure to electromagnetic radiation. For example, an opaque ablatable layer of a substrate layer may be used, and structures may be generated by ablation, or the transmittance of a layer of the film may be modified by exposure with a laser.

[0076] 1 shows the layout of a relief plate precursor 6, including image job data for imaging a mask layer of the relief plate precursor 6. The image job data comprises at least two raster image files 10, 20 having at least two different resolutions R1, R2.

[0077] In Figure 1, a relief plate precursor 6 is fixed to an imaging drum. The drum defines an imaging direction C and a row direction L. The row direction L is, for example, the longitudinal direction of the drum parallel to the drum's rotation axis. The imaging direction C is, for example, the circumferential direction of the drum.

[0078] In the example of Figure 1, the mask layer is imaged in at least two passes. In the first pass, a first pass zone 40 of the mask layer is imaged. The first pass zone 40 corresponds to the area covered by one pass of the imaging head in the imaging direction C. The first pass zone 40 has a dimension in the row direction L that corresponds to the imaging width of the corresponding imaging head. The first pass zone 40 has a dimension in the imaging direction C that is less than or equal to the circumference of the drum. Figure 1 shows two first pass zones 40, each corresponding to an imaging head 50, 60.

[0079] In a second pass following the first pass, a second pass zone 42 is imaged. The second pass zone 42 is located downstream in the row direction C relative to the corresponding first pass zone 40. The second pass zone 42 preferably has the same dimension in the row direction L as the corresponding first zone 40, or it may be different.

[0080] Similar comments apply to the third pass zone 44, the fourth pass zone (not shown in the drawings), etc.

[0081] For example, imaging direction C corresponds to the fast imaging direction. For example, row direction L corresponds to the slow imaging direction.

[0082] The layout is determined taking into account the total imaging time required to image at least one mask layer, for example, to minimize the total imaging time required to image at least one mask layer. According to the embodiment shown in Figure 1, determining the layout includes prioritizing the imaging direction C to arrange raster image files 10, 20 having the same resolution with respect to the row direction L.

[0083] According to some preferred embodiments, when the mask layer of the relief precursor 6 is imaged according to the determined layout, the imaging uses at least two different imaging heads 50, 60, as shown in Figure 1. The first imaging head 50 emits at least one first ablation beam 52 according to a first imaging mode M1. The second imaging head 60 emits at least one second ablation beam 62 according to a second imaging mode M2 ​​that is different from the first imaging mode M1. The first imaging head 50 and the second imaging head 60 simultaneously image the mask layer of the relief precursor 6.

[0084] The imaging modes M1, M2 define at least one of the following characteristics: intensity of at least one laser beam, shape of at least one laser beam, size of at least one laser beam, total number of laser beams used in a pass, and scrambling.

[0085] Even without scrambling, it is possible to obtain straight edges between the imaging strips. As a result, dust lines may be visible at the edges of the strips. This may be unacceptable in certain cases, for example, for high-quality work. A way to avoid so-called "dust lines" is scrambling. In scrambling, pixels at the edges of the imaging strips, either the previous strip or the current strip, are randomly imaged so that the two strips fit together in a complementary way, for example, like a puzzle. For this to happen, the strips must overlap. The number of overlapping pixels is a parameter of the scrambling. Additionally or alternatively, the frequency (every x number of pixels) at which a different random value is selected for scrambling may be changed.

[0086] Different sizes of the at least one ablation beam 50, 60 may be obtained by using different sets of optical lenses. According to a preferred embodiment, the size of the at least one ablation beam, and more generally the imaging mode, is determined by the folder in which the raster image files are located. Each folder defines a different imaging mode.

[0087] Alternatively, the raster image file may include a header containing information about what size ablation beam is used to image the pixels in the raster image file.

[0088] Alternatively, the imaging mode for imaging a raster image file is determined by an imaging mode file corresponding to the raster image file.

[0089] The imaging mode may further define whether to apply a surface screen pattern in the imaging mode and / or whether to apply different screen surface patterns in different imaging modes.

[0090] The different imaging modes are, for example, the modes disclosed in application WO 2020 / 188041.

[0091] 2 shows an embodiment in which the number of relief precursors 6 required to fit the image job data is taken into account when determining the layout. For example, if only the total imaging time is considered, it may be quicker to place a raster image file 10 having a first resolution R1 on a first relief precursor and a raster image file 20 having a second resolution R2 on a second relief precursor. However, this layout may leave large portions of the first and / or second relief precursors empty without raster image files, which would be wasted.

[0092] In the embodiment of Fig. 2, the raster image files 10, 20 with a first resolution R1 and a second resolution R2 are arranged so that they can be laid out on the same relief precursor 6. In particular, the arrangement of the shaded raster image files with the first resolution R1 and the second resolution R2 has been adjusted: several raster image files 20 with the second resolution R2, which would normally have had to be arranged on separate relief precursors, can now be arranged on one relief precursor together with several raster image files with the first resolution R1.

[0093] According to an optional embodiment, the raster image files can be rotated before being placed on the relief precursor. For example, in FIG. 2, the shaded raster image files having a first resolution R1 and a second resolution R2 can be rotated by 90 degrees. These two raster image files can then be swapped, with raster image file 10 having the first resolution R1 being placed in a first zone of the mask layer that can be imaged by an imaging head, and raster image file 20 having the second resolution R2 being placed in a second zone of the mask layer downstream of and separate from the first zone that can be imaged by another imaging head. The modified layout is shown in FIG. 3. The layout in FIG. 3 can further reduce the imaging time of the relief precursor, particularly compared to the layout in FIG. 2.

[0094] 4 illustrates an embodiment where the priority or deadline of an image job is taken into consideration when determining the layout: a shaded raster image file 30 having a third resolution R3 corresponds to an image job with a higher priority than another raster image file 30 having a third resolution R3 that is not shaded.

[0095] The layout of the first relief precursor 6-1 includes at least one raster image file having a first resolution R1 and / or at least one raster image file having a second resolution R2. The at least one raster image file having the first resolution R1 and / or the at least one raster image file having the second resolution R2 has a higher priority than the unshaded raster image file having a third resolution R3. In the case of FIG. 4, placing all raster image files 30 having the third resolution R3 on the second relief precursor 6-2 without considering the priority of the image job could reduce the total imaging time and / or reduce relief precursor waste. However, the shaded image file 30 having the third resolution R3 has a higher priority and is therefore placed on the first relief precursor 6-1 instead. In this manner, the image file 30 can be imaged earlier than other image files 30 having the same resolution. A relief printing plate having a printing area corresponding to this image file can be ready for printing earlier than printing areas corresponding to other image files.

[0096] FIG. 5 illustrates an embodiment in which the layout is determined taking into account whether raster image files of the same relief precursor belong to the same image job. In the example in FIG. 5, raster image files 10C, 10M, 10Y, 10K, and 70 belonging to a first image job are arranged on a first relief precursor 6-1, and raster image files 20C and 20M belonging to a second image job are arranged on a second relief precursor 6-2. In the example in FIG. 5, at least some of the raster image files 10 arranged on the first relief precursor 6-1, for example, all of the raster image files 10, have the same size and / or the same resolution R1. For example, each of the raster image files 10 arranged on the first relief precursor 6-1 corresponds to one color of the image job, for example, a CMYK color. Optionally, as shown in FIG. 5, the first relief precursor 6-1 further comprises at least one additional raster image file 70 having a different size compared to the other raster image files 10 arranged on the first relief precursor 6-1. For example, the additional raster image file 70 comprises a barcode for identifying the image job placed on the first relief precursor 6-1.

[0097] Raster image files 20 having a second size and / or a second resolution R2 are arranged on the second relief precursor 6-2, e.g., each raster image file 20 arranged on the second relief precursor 6-2 corresponds to one color of the image job.

[0098] Of the four criteria for determining the layout mentioned above, namely the total imaging time required to image at least one mask layer, the number of relief precursors required to fit the image job data, whether raster image files of the same relief precursor belong to the same image job, the priority or deadline of the image job, etc., a balance between different criteria may be considered rather than just one criterion (and thus the others are ignored), such as: the total imaging time required to image at least one mask layer;

[0099] According to some embodiments, the weighting factors for determining at least two layouts containing the same image job data and / or for determining layouts of two different image job data can be modified. For example, at least one of the weighting factors can be input to the processing means through a user interface according to different customer needs. Alternatively, the weighting factors can be fixed.

[0100] FIG. 6 illustrates an embodiment according to the second aspect of the present disclosure. A first raster image file 100 and a second raster image file 200 are disposed on a relief precursor 6. For example, the raster image files 100 and 200 are rectangular. Each raster image file 100 and 200 includes at least one image area I comprising imaging pixels. At least one of the image areas I may not be rectangular. In the example illustrated in FIG. 6, one image area I is circular, and another image area I is triangular. An outer portion of at least one image area I of the first raster image file 100 overlaps an outer portion of at least one image area I of the second raster image file 200, forming an overlapping area 250. According to some embodiments as illustrated in FIG. 6, the overlapping area 250 between the first raster image file 100 and the second raster image file 200 does not include imaging pixels.

[0101] The imaging head can move more quickly in zones of the relief precursor corresponding to non-image areas of the raster image file comprising non-imaged pixels than in zones of the relief precursor corresponding to imaged areas comprising imaged pixels of the raster image file. According to one embodiment, an increased imaging head movement speed is taken into account when determining the layout, since if some imaged pixels of a raster image file in one area overlap only with non-imaged pixels of another raster image file, the imaging head movement speed in this area will decrease.

[0102] Figure 7 illustrates another embodiment according to the second aspect of the present disclosure. The figure shows four raster image files 100, 200, 300, and 400. At least one of the raster image files, in the example of Figure 7, comprises at least one image area I comprising imaged pixels and at least one non-image area NI comprising non-imaged pixels. For example, at least one non-image area NI at least partially surrounds at least one image area I. As shown in Figure 7, overlapping of cutting marks is avoided.

[0103] The overlapping may include overlapping only the non-image regions of the two raster image files 100, 200. The cut marks 270 corresponding to a raster image file may overlap the non-image regions NI of another raster image file (the cut marks corresponding to the second raster image file 200 overlap the non-image regions NI of the first raster image file 100), and / or the cut marks 270 corresponding to a raster image file may not overlap the non-image regions NI of another raster image file (the cut marks 270 corresponding to the first raster image file 100 do not overlap the non-image regions NI of the second raster image file 200, and the cut marks corresponding to the second raster image file 200 do not overlap the non-image regions NI of the third raster image file 300).

[0104] The overlapping may include overlapping a non-image region NI of one raster image file with an image region I of another raster image file (the non-image region NI of the fourth raster image file 400 overlaps the image region I of the third raster image file 300, and the non-image region NI of the third raster image file 300 overlaps the image region I of the fourth raster image file 400). The cutting marks 270 may or may not overlap with the non-image regions NI of another raster image file (the cutting marks 270 corresponding to the fourth raster image file 400 overlap with the non-image regions NI of the third raster image file 300).

[0105] 8 illustrates another embodiment according to the second aspect of the present disclosure similar to FIG. 6 . A first raster image file 100 has at least one image region I comprising imaged pixels. The first raster image file 100 further has at least one non-image region NI comprising non-imaged pixels. In the example of FIG. 8 , the at least one non-image region NI is a boundary surrounding at least a portion of, for example, a complete perimeter of, the image region I. A second raster image file 200 has at least one image region I comprising imaged pixels. The first raster image file 100 overlaps with the second raster image file 200 in an overlap region 250.

[0106] 8, overlapping the first raster image file 100 and the second raster image file 200 in the layout includes avoiding overlap between image region I of the second raster image file 200 and non-image region N1 of the first raster image file 100. Image region I of the first raster image file 100 and / or the second raster image file 200 may be partially or completely located within overlap region 250, as shown in FIG. 8, or may be outside overlap region 250, as shown in FIG.

[0107] Figure 9 shows another embodiment according to the second aspect of the present disclosure. Features of Figure 9 are the same as those in Figure 8 unless otherwise noted below.

[0108] In this embodiment, the second raster image file 200 has at least one non-image area NI comprising non-image pixels. The non-image area NI, for example, surrounds the image area I of the second raster image file 200. At least one non-image area NI of the second raster image file 200 overlaps with at least one non-image area NI of the first raster image file 100. The image area I of the first raster image file 100 does not overlap with the image area I of the second raster image file 200. The non-image area NI of the second raster image file 200 may be partially located within the overlapping area 250, completely located within the overlapping area 250, or not overlapping with the overlapping area 250, as shown in FIG. 9 .

[0109] 10 illustrates an embodiment of a system comprising a raster image processing (RIP) module 510 and an imaging system 600. The imaging system 600 comprises a processing module 610 and an imaging device 620 (e.g., an imager).

[0110] The RIP module 510 converts a source image file, here a PDF file, into a raster image file, which is input to the processing module 610 of the imaging system 600. The RIP module 510 is a component used in image processing to generate a raster image file, also known as a bitmap. The source image file may be a page description in a high-level page description language such as PostScript, Portable Document Format, XPS, or another bitmap. In the latter case, the RIP applies either a smoothing algorithm or an interpolation algorithm to the input bitmap to generate an output bitmap. Raster image processing is the process of converting vector digital information, such as a PostScript file, into a high-resolution raster image file. The RIP module 510 is typically implemented either as a software component of an operating system or as a firmware program running on a microprocessor.

[0111] The RIP module 510 has a layout function that determines at least one layout for imaging at least one relief precursor. The layout is determined according to an embodiment of the present disclosure. The RIP module 510 is configured to generate a combined raster image file, the combined raster image file comprising raster image files arranged according to the determined layout. The RIP module 510 includes a memory configured to store the combined raster image file. The RIP module 510 is configured to send the combined raster image file to an imaging system 600, such as an imaging device 620, to image a mask layer of the relief precursor.

[0112] According to one embodiment, the combined raster image file is input to processing module 610 of imaging system 600. In processing module 610, the following steps are performed: receiving a combined raster image file; analyzing the image data of the combined raster image file; determining control data based on the analyzed image data, the control data being data for controlling settings of an imaging device to modify physical characteristics of generated image features corresponding to pixels of the combined raster image file; Outputting control data to the imaging device 620 for imaging the relief precursor.

[0113] During imaging, the imaged pixels are transferred to the mask layer as ablated spots or spots with varying transmittance of the electromagnetic radiation used to harden the photosensitive layer. When the photosensitive layer of the relief precursor plate covered by the imaged mask layer is hardened, for example, by electromagnetic radiation, the areas exposed through the imaged spots are hardened, while the areas covered by the non-imaged portions of the mask layer remain unhardened. The photosensitive layer is then developed together with the mask layer, for example, by treating with a liquid (e.g., solvent or water) in a washing step to wash away the unhardened portions of the photosensitive layer and the mask layer, or by thermal development with the aid of a developing material (e.g., a nonwoven polymer web). In this way, a relief plate is obtained.

[0114] While the principles of the present invention have been described above with reference to specific embodiments, it should be understood that this description is by way of example only and does not limit the scope of protection determined by the appended claims.

Claims

1. A method for determining at least one layout for imaging at least one relief precursor (6), comprising the steps of: receiving image job data for at least one image job comprising at least two raster image files (10, 20) having at least two different resolutions (R1, R2) and / or at least two different quality settings requiring different image modes (M1, M2); - determining, using processing means, at least one layout comprising said image job data for imaging said at least one mask layer of said at least one relief precursor (6) taking into account the total imaging time required to image said at least one mask layer; A method comprising:

2. 2. The method of claim 1, wherein the step of determining at least one layout includes a step of prioritizing the placement of raster image files having the same resolution and / or the same quality setting in a first orientation (C) over a second orientation (L) different from the first orientation (C).

3. The method of claim 2 , wherein the first direction (C) is substantially perpendicular to the second direction (L).

4. 4. A method according to claim 2 or 3, wherein said first direction (C) is the circumferential direction of a drum to which said relief precursor (6) is fixed during imaging.

5. The method according to any one of claims 1 to 4, wherein the step of determining at least one layout further comprises the step of taking into account the number of relief precursors (6) required to fit the image job data.

6. 6. The method according to any one of claims 1 to 5, wherein said step of determining at least one layout further comprises the step of considering whether raster image files of the same relief precursor (6) belong to the same image job of said at least one image job.

7. The method of any one of claims 1 to 6, wherein said step of determining at least one layout further comprises the step of considering an image job priority or a deadline of said at least one image job.

8. 8. The method of claim 1, wherein determining at least one layout comprises minimizing a total imaging time required to image the at least one mask layer.

9. 9. The method according to any one of claims 1 to 8, wherein the step of determining at least one layout comprises using weighting factors for two or more of the following criteria: total imaging time needed to image the at least one mask layer; number of relief precursors (6) needed to match the image job data; whether raster image files of the same relief precursor (6) belong to the same image job of the at least one image job; image job priority or deadline of the at least one image job; amount of waste.

10. 10. The method of claim 9, wherein at least one of the weighting factors is input to the processing means through a user interface.

11. The method comprises: determining at least two different possible layouts including all of the image job data; assigning a score to each determined layout taking into account said weighting factors; selecting the layout with the highest score as the layout for imaging the at least one mask layer; 11. The method of claim 9 or 10, further comprising:

12. 12. The method according to any one of claims 1 to 11, wherein the step of determining is performed such that the total area occupied by the raster image files of each mask layer of the at least one relief precursor is at least 60%, preferably more than 70%, more preferably more than 80% of the total printable area of ​​the mask layer.

13. 13. The method according to any one of claims 1 to 12, wherein the step of determining a layout further comprises the step of arranging the raster image files (10C, 10M, 10Y, 10K) of the same image job on at least one predetermined relief precursor.

14. The method of claim 13 , wherein the at least one predetermined relief precursor is a single relief precursor or multiple consecutive relief precursors imaged one after the other.

15. The method comprises: imaging said mask layer of a relief precursor (6) according to said determined layout; further comprising 15. The method according to any one of claims 1 to 14, wherein a first imaging head (50) emitting at least one first ablation beam (52) according to a first imaging mode (M1) and a second imaging head (60) emitting at least one second ablation beam (62) according to a second imaging mode (M2) different from the first imaging mode (M1) simultaneously image the mask layer of the relief precursor (6).

16. 16. The method of claim 15, wherein the imaging mode (M1, M2) defines at least one of the following characteristics: intensity of at least one laser beam, shape of at least one laser beam, size of at least one laser beam, total number of laser beams used in the imaging head, scrambling.

17. A method for determining at least one layout for imaging at least one relief precursor (6), comprising the steps of: receiving image job data for at least one image job, the image job data comprising a plurality of raster image files (100, 200); - determining, using processing means, at least one layout comprising said image job data for imaging at least one mask layer of said at least one relief precursor (6), comprising superimposing at least two of said plurality of raster image files (100, 200) in said layout; A method comprising:

18. 18. The method of claim 17, wherein the image job data comprises at least two display raster image files having cutting marks (270) associated with the at least two raster image files, and the method includes a step of taking the cutting marks (270) into account to determine the at least one layout, and preferably avoiding the cutting marks (270) of the at least two display raster image files from intersecting with each other.

19. The at least two raster image files are a first raster image file (100) having at least one image area (I) comprising imaged pixels and at least one non-image area (NI) comprising non-imaged pixels; a second raster image file (200) having at least one image area (I) with imaging pixels; Equipped with 19. The method of claim 17 or 18, wherein the step of overlapping the at least two raster image files in the layout includes a step of avoiding overlap between the image area (I) of the second raster image file (200) and the non-image area (NI) of the first raster image file (100).

20. 20. The method according to claim 18 or 19, wherein the cutting marks are arranged at the edges of image areas (I) of the at least one image area (I).

21. 21. The method of claim 19 or 20, wherein said at least one non-image area (NI) comprises a border surrounding said at least one image area (I).

22. 22. The method of claim 18 or 21, wherein the boundary comprises the cutting mark.

23. the second raster image file (200) has at least one non-image area (NI) comprising non-image pixels; 23. The method of any one of claims 19 to 22, wherein the step of overlapping the at least two raster image files in the layout comprises overlapping the non-image areas (NI) of the second raster image file (200) with the non-image areas (NI) of the first raster image file (100).

24. Flexographic printing plate obtainable by the method according to any one of claims 1 to 23.

25. A computer program or computer program product comprising computer executable instructions for controlling a method according to any one of claims 1 to 23 when said program is run on a computer.

26. A digital data storage medium encoded with a machine-executable program of instructions for performing any of the steps of the method of any one of claims 1 to 23.

27. A system for producing relief printing forms, comprising control means for carrying out the method according to any one of claims 1 to 23.

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