Airflow control in printing systems via media alignment and related devices, systems and methods

Abstract

To improve the accuracy of the placement of droplets in printing systems and to reduce the appearance of a blur in a printed media product.SOLUTION: A printing system 100 comprises a printhead 110 to eject a print fluid to a deposition region. A movable support surface 120, such as a belt, is used to transport print media through a deposition region, with the print media being held against the movable support surface by vacuum suction through holes 121 in the movable support surface. A media registration device 155 loads the print media onto the movable support surface and registers the print media with a location of the movable support surface. The movable support surface comprises no-suction regions 151 in which the vacuum suction through the movable support surface is prevented. The no-suction regions extend across the width of the movable support surface in a cross-process direction, and are arranged at predetermined intervals along the process direction. A control system 130 causes the media registration device to register each of the print media with respective one of the no-suction-regions.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] Aspects of the present disclosure relate generally to inkjet printing, and more particularly to inkjet printing systems having media transport assemblies that utilize vacuum suction to hold and transport print media. Related devices, systems, and methods are also disclosed. [Background technology]

[0002] In some applications, inkjet printing systems use an ink deposition assembly having one or more printheads and a media transport assembly to move print media (e.g., a substrate such as paper, an envelope, or other substrate suitable for printing with ink) through an ink deposition region (e.g., an area beneath the printheads) of the ink deposition assembly. Inkjet printing systems form printed images on the print media by ejecting ink from the printheads onto the media as the media passes through the deposition region. In some inkjet printing systems, the media transport assembly utilizes vacuum suction to help hold the print media against a movable support surface (e.g., a conveyor belt, a rotating drum, etc.) of a transport device. The vacuum suction to hold the print media against the support surface can be achieved using a vacuum source (e.g., a fan) and a vacuum plenum that fluidly couples the vacuum source to the side of the movable support surface opposite the side that supports the print media. The vacuum source creates a vacuum in the vacuum plenum, causing vacuum suction through holes in the movable support surface that are fluidly coupled to the vacuum plenum. When the print media is introduced onto the movable support surface, the vacuum suction generates a suction force that holds the print media against the movable support surface. A media transport assembly that utilizes vacuum suction can allow the print media to be held securely in place without slippage while being transported through an ink deposition area beneath the ink deposition assembly, thereby helping to ensure accurate positioning of the print media relative to the print head and therefore a more accurate printed image. Vacuum suction can also allow the print media to be held flat as it passes through the ink deposition area, which can also help to increase the accuracy of the printed image and can help prevent portions of the print media from lifting and hitting portions of the ink deposition assembly, potentially causing jams or damage.

[0003] One problem that can arise in inkjet printing systems that include media transport assemblies that utilize vacuum suction is unintended smearing of the image resulting from airflow induced by the vacuum suction. In some systems, such smearing can occur in portions of the printed image near the edges of the print media, particularly near the leading or trailing edges of the print media in the transport direction (sometimes referred to as the process direction). During a print job, the print media are spaced apart on the movable support surface as they are transported through the deposition region of the ink deposition assembly, so that portions of the movable support surface between adjacent print media are not covered by any print media. This region between adjacent print media is referred to herein as the inter-media zone. Accordingly, adjacent to both the leading and trailing edges of each print media in the inter-media zone, the movable support surface has uncovered holes. Because these holes are uncovered, the vacuum in the vacuum plenum induces airflow through the uncovered holes. This airflow can deflect ink droplets and satellite droplets as they travel from the print head to the substrate, thereby causing image smearing.

[0004] A need exists to improve the accuracy of drop placement in inkjet printing systems and reduce the appearance of bleed in the final printed media product. A further need exists to address the problem of bleed in a reliable manner and while maintaining printing and transport speeds in order to provide an efficient inkjet printing system. Summary of the Invention

[0005] Embodiments of the present disclosure may solve one or more of the problems set forth above and / or may demonstrate one or more of the desirable features set forth above. Other features and / or advantages may become apparent from the following description.

[0006] According to at least one embodiment of the present disclosure, a printing system includes an ink deposition assembly, a media transport assembly, and a control system. The ink deposition assembly includes a print head arranged to eject printing fluid into a deposition region of the ink deposition assembly. The media transport assembly includes a movable support surface having holes therethrough, a media alignment device, and a vacuum suction source. The media alignment device is configured to load the print media onto the movable support surface and align the print media to a location on the movable support surface. The media transport assembly is configured to hold the print media against the movable support surface by vacuum suction through the holes and transport the print media along the process direction through the deposition region. The movable support surface includes non-suction areas where vacuum suction is prevented, the non-suction areas extending across the movable support surface in the cross-process direction and distributed along the movable support surface in the process direction. The control system is configured to cause the media alignment device to align each of the print media with a respective one of the non-suction areas.

[0007] According to at least one embodiment of the present disclosure, a method for transporting print media through a printing system includes generating a vacuum suction and applying a suction force by communicating the vacuum suction through one or more first regions of a movable support surface that moves through an ink deposition region of the printing system. The method further includes preventing the vacuum suction from communicating through one or more second regions of the movable support surface that moves through the ink deposition region. The method further includes loading the print media onto the movable support surface such that the print media is held against the movable support surface by the suction force through the one or more first regions and aligned with one of the second regions, transporting the print media through the ink deposition region via the movable support surface, and ejecting a printing fluid from a print head to deposit the printing fluid on the print media at the deposition region.

[0008] According to at least one embodiment of the present disclosure, a method includes loading a print medium onto a movable support surface of a media transport assembly of a printing system. The print medium is held against the movable support surface via vacuum suction through holes in the movable support surface. The movable support surface includes non-suction areas where vacuum suction is prevented. The non-suction areas extend across the movable support surface in a cross-process direction and are distributed in a process direction along the movable support surface. The method further includes selecting a media registration scheme from a plurality of media registration schemes the printing system is configured to use, the plurality of media registration schemes including a first media registration scheme in which a trailing edge of each print medium is registered against one of the non-suction areas. The method further includes registering the print medium using the selected registration scheme, transporting the print medium in a process direction via the movable support surface through a deposition zone of a print head of the printing system, and ejecting printing fluid from the print head to deposit the printing fluid on the print medium at the deposition zone. [Brief explanation of the drawings]

[0009] The present disclosure can be understood from the following detailed description taken alone or in conjunction with the accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiments of the present teachings and, together with the description, explain certain principles and operations. In the drawings:

[0010] [Figure 1A] 1A-1C illustrate schematic representations of airflow patterns relative to the printhead assembly, transport device, and print media during different stages of print media transport through the ink deposition area of ​​a conventional inkjet printing system, and the resulting bleed effects in the print media product. [Figure 1B] 1A-1C illustrate schematic representations of airflow patterns relative to the printhead assembly, transport device, and print media during different stages of print media transport through the ink deposition area of ​​a conventional inkjet printing system, and the resulting bleed effects in the print media product. [Figure 1C]1A-1C illustrate schematic representations of airflow patterns relative to the printhead assembly, transport device, and print media during different stages of print media transport through the ink deposition area of ​​a conventional inkjet printing system, and the resulting bleed effects in the print media product. [Figure 1D] 1A-1C illustrate schematic representations of airflow patterns relative to the printhead assembly, transport device, and print media during different stages of print media transport through the ink deposition area of ​​a conventional inkjet printing system, and the resulting bleed effects in the print media product. [Figure 1E] 1A-1C illustrate schematic representations of airflow patterns relative to the printhead assembly, transport device, and print media during different stages of print media transport through the ink deposition area of ​​a conventional inkjet printing system, and the resulting bleed effects in the print media product. [Figure 1F] 1A-1C illustrate schematic representations of airflow patterns relative to the printhead assembly, transport device, and print media during different stages of print media transport through the ink deposition area of ​​a conventional inkjet printing system, and the resulting bleed effects in the print media product. [Figure 1G] 1A-1C illustrate schematic representations of airflow patterns relative to the printhead assembly, transport device, and print media during different stages of print media transport through the ink deposition area of ​​a conventional inkjet printing system, and the resulting bleed effects in the print media product. [Figure 1H] 1A-1C illustrate schematic representations of airflow patterns relative to the printhead assembly, transport device, and print media during different stages of print media transport through the ink deposition area of ​​a conventional inkjet printing system, and the resulting bleed effects in the print media product. [Figure 1I] 1A-1C illustrate schematic representations of airflow patterns relative to the printhead assembly, transport device, and print media during different stages of print media transport through the ink deposition area of ​​a conventional inkjet printing system, and the resulting bleed effects in the print media product.

[0011] [Figure 2] 1 includes a block diagram illustrating components of an embodiment of an inkjet printing system including an air flow control system.

[0012] [Figure 3] FIG. 1 is a schematic diagram of an ink deposition assembly, a media transport assembly, and an air flow control system of an embodiment of an inkjet printing system.

[0013] [Figure 4] FIG. 4 is a top plan view of the printhead assembly of the inkjet printing system of FIG. 3.

[0014] [Figure 5A] 5 is a cross-sectional view of the inkjet printing system of FIG. 4, the cross section being taken along line D in FIG. 4. [Figure 5B] 5 is a cross-sectional view of the inkjet printing system of FIG. 4, the cross section being taken along line D in FIG. 4.

[0015] [Figure 6] FIG. 2 is a plan view of a movable support surface of one embodiment of a printing system.

[0016] [Figure 7A] FIG. 2 is a plan view from above of a movable support surface of an embodiment of a printing system. [Figure 7B] FIG. 2 is a plan view from above of a movable support surface of an embodiment of a printing system. DETAILED DESCRIPTION OF THE INVENTION

[0017] As mentioned above, when the inter-media zone is near or below the print head, uncovered holes in the inter-media zone can create crossflows that can deflect ink droplets (large droplets) and satellite droplets (small droplets) ejected from the print head away from the print head, potentially causing image bleed. To better explain some of the phenomena that create bleed problems, refer to FIGS. 1A-1I. FIGS. 1A, 1D, and 1G schematically illustrate a print head 10 printing on a print medium 5 near the trailing edge TE, leading edge LE, and middle portion of the print medium 5, respectively. FIGS. 1B, 1E, and 1H show enlarged views of regions A, B, and C of FIGS. 1A, 1D, and 1G, respectively. FIGS. 1C, 1F, and 1I show enlarged photographs of printed images, which include printed lines near the trailing edge TE, leading edge LE, and middle portion of the paper, respectively.

[0018] As shown in FIGS. 1A, 1D, and 1G, an inkjet printing system includes a printhead 10 that ejects ink through openings 19 in a carrier plate 11 to print on a medium 5 (e.g., print media 5_1 and 5_2), and a movable support surface 20 that transports the print medium 5 in a process direction P, which corresponds to the positive y-axis direction in the figures. The movable support surface 20 is movable (e.g., slides) along the top of a vacuum platen 26, and a vacuum environment is provided on the bottom side of the platen 26. The movable support surface 20 has holes 21, and the vacuum platen 26 has holes 27, which periodically align as the movable support surface 20 moves to expose the area above the movable support surface 20 to the vacuum below the platen 26. In areas where the print medium 5 covers the holes 21, vacuum suction through the aligned holes 21 and 27 generates a force that holds the print medium 5 against the movable support surface 20. However, little or no air flows through these covered holes 21 and 27 because they are blocked by the print media 5. Meanwhile, as shown in Figures 1A and 1D, in the inter-media zone 22, the holes 21 and 27 are not covered by the print media 5_1, 5_2, and therefore the vacuum suction pulls air down through the holes 21 and 27 in the inter-media zone 22. This creates an airflow, indicated by the dashed arrows in Figures 1A and 1D, in the inter-media zone 22 from the area around the print head 10 toward the uncovered holes 21 and 27, with a portion of the airflow passing underneath the print head 10.

[0019] In FIG. 1A , the print medium 5_1 is printed near its trailing edge TE, and therefore the area where ink is currently being ejected (the “ink ejection area”) (e.g., area A in FIG. 1A ) is located downstream of the inter-media zone 22 (upstream and downstream are defined with respect to the process direction P, which is the direction of transport of the print medium by the movable support surface 20). Thus, some of the air drawn toward the inter-media zone 22 flows upstream through the ink ejection area A. More specifically, the vacuum suction from the inter-media zone 22 reduces the pressure in the area immediately above the inter-media zone 22, e.g., area R1 in FIG. 1A , while the area downstream of the print head 10, e.g., area R2 in FIG. 1A , remains at a higher pressure. This pressure gradient causes air to flow upstream from area R2 toward area R1, with the air flow crossing the ink ejection area (e.g., area A in FIG. 1A ) that is between areas R1 and R2. Some of this air may be drawn from the gap 9d between the downstream face of the printhead 10 and the edge of the opening 19 through which the printhead 10 ejects ink. Air flows such as these that cross the ink ejection region are referred to herein as cross-flows 15. In Figure 1A, the cross-flows 15 are flowing upstream, but in other situations, the cross-flows 15 may flow in a different direction.

[0020] As shown in enlarged view A' of FIG. 1B, which includes a close-up of region A, main ink droplets 12 and satellite ink droplets 13 are formed as ink is ejected from print head 10 toward media 5. Satellite droplets 13 are much smaller than main droplets 12, resulting in less mass and momentum; therefore, upstream cross-flow 15a tends to affect satellite droplets 13 more than main droplets 12. Thus, while main droplets 12 may land on print media 5 near their intended deposition locations 16 regardless of cross-flow 15, cross-flow 15 may push satellite droplets 13 from their intended trajectories, causing satellite droplets 13 to land at unintended locations 17 on media 5, displaced from unintended locations 16. This can be seen in the actual printed image of FIG. 1C , where the denser / darker line features are formed primarily by main drops deposited at their intended locations 16, while smaller dots dispersed away from the lines are formed by satellite drops that are blown away from their intended locations 16 and land in unintended locations 17, resulting in a smeared or smeared appearance to the printed lines. In particular, the smearing in FIG. 1C is asymmetrically biased toward the illustrated trailing edge TE of the paper, likely due to the cross-flow 15 near the trailing edge TE blowing primarily in the upstream direction shown in FIGS. 1A and 1B . The inter-media zone 22 may also direct other air flows from the upstream side of the printhead 10 that flow in other directions, such as downstream air flows, but these other air flows do not pass through the area where ink is currently being ejected in the illustrated scenario and therefore do not contribute to the smearing of the image. Only these air flows that cross the ink ejection area are referred to herein as cross-flow.

[0021] 1D-1F show another example of where such bleeding occurs, in this case near the leading edge LE of the print medium 5_2. When printing near the leading edge LE as shown in FIGS. 1C and 1D, the cause of bleeding near the leading edge LE is similar to that described above in connection with the trailing edge TE, except that the ink ejection region is now located upstream of the inter-media zone 22. As a result, the cross-flow 15 across the ink ejection region now originates from the upstream side of the print head 10, e.g., from region R3, and flows downstream to region R4, where there is an uncovered hole in the inter-media zone 22 adjacent to the leading edge LE. For example, air may be drawn from the gap 9u between the upstream face of the print head 10 and the edge of the opening 19 in the carrier plate 11. Thus, when printing near the leading edge LE, satellite droplets 13 are sprayed downstream (in the positive y-axis direction) toward the leading edge LE of the print medium 5_2, as shown in enlarged view B' of Figure 1E, which includes an enlarged view of the ink ejection area B. As shown in Figure 1F, such a phenomenon results in asymmetric bleeding that is biased toward the leading edge LE, and the satellite droplets are deposited at undesired locations 17 relative to their intended locations 16.

[0022] In contrast, as shown in FIG. 1G and the enlarged view C' in FIG. 1H corresponding to the enlarged view of the ejection area C, when the print medium (e.g., print medium 5_2) is being printed on an intermediate portion farther from the trailing and leading edges TE, LE, the inter-media zone 22 may be too far from the print head 10 and the ink ejection area C, inducing airflow near the ink ejection area C, resulting in little or no cross-flow 15. Because the cross-flow 15 is absent or weak away from the edge of the print medium 5, satellite droplets 13 in this region are likely to stray and be sprayed. Thus, as shown in FIGS. 1H and 1I, when printing farther from the edge of the print medium 5_2, satellite droplets land at locations 18 much closer to their intended locations 16, resulting in less image bleeding. The satellite droplet deposition location 18 may vary slightly from the intended location 16 due to other factors affecting the satellite droplets, but the deviation is less than near the leading or trailing edges and therefore does not result in significant bleeding.

[0023] The embodiments disclosed herein may inhibit some of the cross-flow to, among other things, reduce possible resulting image bleed. By inhibiting the cross-flow, droplets (including, for example, satellite droplets) ejected from the print head are more likely to land closer to or at their intended deposition locations. According to various embodiments, the movable support surface includes multiple non-suction areas where suction is prevented through the movable support surface. For example, in some embodiments, holes through the movable support surface may be omitted in the non-suction areas, or existing holes may be blocked using tape or other patch-type material and a process in the non-suction areas to prevent suction through the holes. The non-suction areas may extend across the movable support surface in the cross-process direction and may be distributed at intervals along the process direction. According to various embodiments, the airflow control system disclosed herein may reduce or eliminate cross-flow by controlling the alignment of print media transported by the movable support surface so that one of the trailing edge and leading edge of each print media is aligned with one of the non-suction areas. Thus, the trailing edge (or leading edge) of each print medium is adjacent to one of the non-suction regions, and because no holes are present (or the holes are blocked) in the non-suction region, vacuum suction from the adjacent inter-media zone that would otherwise induce air flow near that edge is reduced or eliminated. Thus, printing occurs near the trailing edge (or leading edge), but cross-flow near that edge is reduced in intensity or eliminated. With cross-flow near the trailing edge (or leading edge) of the print medium reduced or eliminated, ink drops (including satellite drops) are more likely to land at or near their intended deposition locations, thus reducing the amount of bleed near that edge of the print medium.

[0024] As noted above, aligning one edge of a print medium with a non-suction region reduces image bleed near that edge, but does not necessarily reduce image bleed near the opposite edge or cross-process edge for smaller width print media. Thus, in some embodiments, in addition to aligning one edge with a non-suction region, a gap is provided on one side of the print head, but not on the other side (or the gap is blocked, if present) to combat image bleed near the edge of the print medium opposite the aligned edge. For example, in some embodiments in which the trailing edge TE is aligned with a non-suction region, a downstream gap is provided on the downstream side of the print head, and not an upstream gap (or the upstream gap is blocked, if present), thereby reducing bleed near the leading edge LE. Conversely, in embodiments in which the leading edge LE is aligned with a non-suction region, an upstream gap is provided on the upstream side of the print head, and not a downstream gap (or the downstream gap is blocked, if present), thereby reducing bleed near the trailing edge TE. Therefore, as described above, by both aligning the print media with the non-suction area and providing upstream / downstream gaps, image bleed near both the leading edge LE and the trailing edge TE can be reduced. The reasons why providing gaps as described above reduces image bleed are explained in more detail below.

[0025] It has been found that providing a gap downstream of the print head while omitting an upstream gap upstream of the print head (or blocking the upstream gap, if present) reduces the amount of image bleed near the leading edge LE of the print media. This improvement occurs for two main reasons. First, the presence of the downstream gap allows beneficial relief air to be pulled through the downstream gap into the inter-media zone when the leading edge LE is under the print head. For example, in the situation shown in FIG. 1D , relief air 14 flows through downstream gap 9d. The relief air is beneficial for counteracting some of the negative pressure caused by suction from the inter-media zone, which reduces the strength with which air is pulled from elsewhere around the print head, which in turn reduces the strength with which cross-flow is pulled under the print head. The relief air passing through the downstream gap reduces the strength of cross-flow when the leading edge LE is under the print head, thereby reducing the amount of image bleed near the leading edge LE. A second reason for the improvement in image bleed near the leading edge LE is that omitting or blocking the upstream gap prevents cross-flow from being drawn down through the upstream gap when the leading edge LE is under the printhead. An example of such cross-flow can be seen in FIG. 1D , where a portion of cross-flow 15 is drawn down through upstream gap 9u. While omitting or blocking the upstream gap does not eliminate all cross-flow that occurs near the leading edge LE, it removes one significant source of cross-flow that can occur near the leading edge LE, thus reducing the aggregate intensity of cross-flow and, therefore, image bleed near the leading edge LE. Thus, both the beneficial relief air provided by the downstream gap and the blocking of cross-flow through the upstream gap contribute to reducing the amount of image bleed that occurs near the leading edge.

[0026] Providing a downstream gap while omitting or blocking the upstream gap tends to reduce image bleed near the leading edge LE, but can also contribute to increased image bleed at the trailing edge TE if other measures are not taken. This occurs because the air flowing through the downstream gap is beneficial relief air when the leading edge LE is under the print head, but is cross-flow when the trailing edge TE is under the print head. Similarly, omitting or blocking the upstream gap prevents some cross-flow when the leading edge LE is under the print head, but this also prevents beneficial relief air from being provided when the trailing edge TE is under the print head. Thus, improving image bleed at the leading edge LE through the above-described approach may come at the cost of worsening image bleed at the trailing edge TE if other measures are not taken. However, in embodiments in which the trailing edge TE is aligned with a non-suction region, there is little or no suction from the inter-media zone near the trailing edge TE, and therefore the above-described worsening of image bleed near the trailing edge TE due to the gap around the print head does not occur. Therefore, in some embodiments, aligning the trailing edge TE to the non-suction area is beneficial in combination with providing an open downstream gap and omitting / blocking the upstream gap, thus allowing for a sufficient reduction in image bleeding at both the trailing edge TE and the leading edge LE.

[0027] Conversely, if the open and blocked gaps are reversed (i.e., the upstream gap is open but the downstream gap is omitted or blocked), this reduces the amount of image bleed near the trailing edge TE, but not the leading edge LE. This reduction in image bleed occurs for reasons similar to those discussed above with respect to the leading edge LE, except that, with respect to the leading edge LE, beneficial relief air tends to emerge from the upstream gap and cross-flow tends to enter from the downstream gap. Additionally, this improvement at the leading edge LE by providing an open upstream gap and omitting or blocking the downstream gap may come at the cost of worsening image bleed at the trailing edge TE if no measures are taken. However, in embodiments in which the leading edge LE is aligned with a non-suction region, there is little or no suction from the inter-media zone near the leading edge LE, and therefore the aforementioned worsening of image bleed near the leading edge LE due to gaps around the print head does not occur. Therefore, in some embodiments, aligning the leading edge LE to the non-suction area is beneficial in combination with providing an open upstream gap and omitting / blocking the downstream gap, thus allowing for a sufficient reduction of image bleeding at both the trailing edge TE and the leading edge LE.

[0028] Referring now to FIG. 2, an embodiment of a printing system will be described in more detail. In the drawings and description herein, a numerical index, such as “_1,” “_2,” etc., is added after the reference numeral of some components. When there are multiple similar components and it is desired to refer to a specific one of those components, the same reference numeral is used, with a different index added to distinguish between the individual components. However, when components are referred to generally or collectively without the need to distinguish between specific ones, the index may be omitted from the reference numeral. Thus, as an example, a print medium 5 may be labeled and referred to as a first print medium 5_1, as in FIG. 1A, when it is desired to identify a specific one of the print media 5, but may be labeled and referred to simply as print medium 5 in other cases where it is not desired to distinguish between multiple print media 5. Additionally, letters, such as “a,” “b,” “u,” “d,” etc., are added after the reference numeral of some components.

[0029] 2 is a block diagram that schematically illustrates a printing system 100 that utilizes the airflow control system described above. Printing system 100 includes an ink deposition assembly 101 for depositing ink on print media, a media transport assembly 103 for transporting the print media through ink deposition assembly 101, and a control system 130 for controlling the operation of printing system 100. These components of printing system 100 are described in more detail below. Additionally, various components of printing system 100 are involved in controlling airflow around the print heads, and therefore these parts may be collectively referred to as airflow control system 150.

[0030] The ink deposition assembly 101 includes one or more printhead modules 102. For simplicity, one printhead module 102 is shown in FIG. 2 , but any number of printhead modules 102 may be included in the ink deposition assembly 101. In some embodiments, each printhead module 102 may correspond to a particular ink color, such as cyan, magenta, yellow, and black. Each printhead module 102 includes one or more printheads 110 configured to eject printing fluid, such as ink, onto a print medium to form an image. For simplicity, one printhead 110 is shown in FIG. 2 in the printhead module 102, but any number of printheads 110 may be included per printhead module 102. The printhead module 102 may include one or more walls, including a bottom wall, which may be referred to herein as a carrier plate 111. The carrier plate 111 includes a printhead opening 119 through which the printhead 110 is disposed to eject ink. In some embodiments, the carrier plate 111 supports the printheads 110. In other embodiments, the print head 110 is supported by other structures. The print head module 102 may also include additional structures and devices to support and facilitate operation of the print head 110, such as ink supply lines, ink reservoirs, electrical connections, etc., as known in the art.

[0031] As shown in FIG. 2 , media transport assembly 103 includes movable support surface 120, vacuum plenum 125, vacuum source 128, and media alignment device 155. Movable support surface 120 transports print media through the deposition region of ink deposition assembly 101. Vacuum plenum 125 provides vacuum suction from vacuum source 128 to one side (e.g., the bottom side) of movable support surface 120, and print media is supported on the opposite side (e.g., the top side) of movable support surface 120. Holes 121 through movable support surface 120 communicate the vacuum suction through surface 120 such that the vacuum suction presses the print media down against surface 120. Media alignment device 155 loads print media onto movable support surface 120 and aligns the print media with various alignment datums.

[0032] The movable support surface 120 is movable relative to the ink deposition assembly 101, such that as the movable support surface 120 moves, the print medium held against the movable support surface 120 is transported relative to the ink deposition assembly 101. Specifically, the movable support surface 120 transports the print medium through a deposition region of the ink deposition assembly 101, which is an area where a printing fluid (e.g., ink) is ejected onto the print medium, such as an area beneath the print head 110. The movable support surface 120 can be actuated to move relative to the ink deposition assembly 101 and can comprise any structure having holes 121 that allow vacuum suction to press down on the print medium, such as a belt, drum, or the like.

[0033] Vacuum plenum 125 comprises baffles, walls, or any other structure arranged to surround or define an environment in which a vacuum condition (e.g., a low-pressure condition) is maintained by vacuum source 128, and plenum 125 fluidly couples vacuum source 128 to movable support surface 120 such that movable support surface 120 is exposed to the vacuum condition within vacuum plenum 125. In some embodiments, movable support surface 120 is supported by vacuum platen 126, which may be the top wall of vacuum plenum 125. In such embodiments, movable support surface 120 is fluidly coupled to the vacuum in plenum 125 via holes 127 through vacuum platen 126. In some embodiments, movable support surface 120 is itself one of the walls of vacuum plenum 125 and is therefore directly exposed to the vacuum in plenum 125. Vacuum source 128 may be any device configured to remove air from plenum 125 to create a low-pressure condition in plenum 125, such as a fan, pump, etc.

[0034] The movable support surface 120 includes non-suction regions 151, as described above. The non-suction regions 151 include portions of the movable support surface 120 that do not allow fluid communication of vacuum suction through the movable support surface 120. In some embodiments, the non-suction regions 151 include portions of the media support surface 120 that are free of holes 121. In other embodiments, the non-suction regions 151 include portions of the media support surface 120 where the holes 121 are blocked, for example, by covering or filling the holes 121 with a material (e.g., tape). The non-suction regions 151 each extend in the cross-process direction across the movable support surface 120 and are distributed at intervals along the process direction.

[0035] The purpose of the non-suction regions 151, as discussed above, is to reduce the amount of suction that occurs near the leading or trailing edge of the print media. To do this, each non-suction region 151 must extend a sufficient width in the cross-process direction. Therefore, it should be understood that references to non-suction regions herein do not refer to the typical space that exists between adjacent holes 121 or adjacent rows of holes 121 in the movable support surface. Instead, each non-suction region 151 extends far enough in the cross-process direction to occupy the space that would be occupied by at least several rows of holes 121 if the non-suction region 151 were not present. In other words, if the pitch (spacing) between adjacent rows of holes 121 in the cross-process direction is d1, then the width of the non-suction region 151 in the cross-process direction is at least N·d1, where N is 2 or greater. The specific width of the non-suction region 151 in the cross-process direction may vary from system to system and may be selected based on considerations such as the desired gap between adjacent print media (wider suction regions may involve larger gaps between print media) and the desired amount of bleed reduction (wider non-suction regions may result in better bleed reduction). The optimal width of the non-suction region 151 for a given system and a given set of design goals may be determined experimentally, for example, by testing different widths of the non-suction region 151 and measuring the amount of image bleed for each different width. In some embodiments, the width of the non-suction region 151 in the cross-process direction may be equal to the width of the ink deposition region of a single print head 110 in the cross-process direction. In some embodiments, the width of the non-suction region 151 in the cross-process direction may be equal to the width of the print head 110 in the cross-process direction. In some embodiments, the width of the non-suction region 151 in the cross-process direction may be equal to the width of the print head module 102 in the cross-process direction. In some embodiments, the width of the non-suction region 151 in the cross-process direction may be equal to the width of the print head module 102 in the cross-process direction. In some embodiments, the width of the non-suction region 151 may be at least 15 mm. In some embodiments, the width of the non-suction area 151 may be at least 25 mm.

[0036] The spacing between adjacent suction regions 151 in the process direction can be any desired spacing. In some embodiments, the spacing is set to approximately accommodate one or more sizes of print media that the printing system 100 is designed to use. For example, in one embodiment in which the movable support surface 120 is approximately 2060 mm long, the non-suction regions 151 are spaced approximately 257 mm apart (center-to-center), which can facilitate the use of various standard sizes of print media. In some embodiments, the spacing between the non-suction regions is set to accommodate the longest length of print media that the system is designed to use. In some embodiments, the spacing between the suction regions 151 is not uniform. For example, in some embodiments, the spacing between the suction regions can alternate between small spacings (e.g., corresponding to the smallest size of print media) and larger spacings.

[0037] As described above and as is well known to those skilled in the art, the media registration device 155 loads the print media onto the movable support surface 120 and registers the print media with respect to various registration data. The process direction registration data extends in the process direction and is fixed relative to the transport device 103 (see, for example, the process direction registration data Reg_P in FIGS. 4, 6, and 7). As each print media is loaded onto the movable support surface 120, the edge of the print media extending along the process direction is aligned with the process direction registration data. Herein, the side of the media transport assembly 103 closest to the process direction registration data Reg_P is referred to as the outside of the media transport assembly 103, and the opposite side is referred to as the inside. For example, in FIG. 4, the right side of the platen 326 is the outside. In practice, registration data Reg_P can be located on both sides of the media transport assembly 103; therefore, the side of the media transport assembly 103 that is considered the outside will vary from system to system (or from time to time within the same system) as the print media is accidentally registered. In addition, multiple cross-process alignment data extend in the cross-process direction (see, for example, cross-process alignment data Reg_CP in FIG. 6 ). Unlike the process direction alignment data, the cross-process alignment data is fixed to the movable support surface 120 and moves in the process direction. When each printing medium is placed on the movable support surface 120, the edge of the printing medium extending along the cross-process direction (leading edge LE or trailing edge TE) is aligned with one of the cross-process alignment data. Therefore, by aligning each printing medium with one of the process direction alignment data and the cross-process alignment data, the correct location and orientation of the printing medium with respect to the movable support surface 120 can be achieved, enabling accurate printing of an image on the printing medium. As discussed in more detail below, in the embodiments disclosed herein, the cross-process data is part of the non-suction regions 151, which means that each cross-process datum is located at or within the boundary of one of the non-suction regions 151.

[0038] It should be noted that the alignment data corresponds to a line or axis that conceptually exists, but there is not necessarily a physical feature that corresponds to the data. For example, the process direction alignment data may correspond to a line that is a certain distance from the edge of the movable support surface, but there is not necessarily any feature on the movable support surface that represents this line.

[0039] Various media registration devices for loading and registering print media onto a movable support surface are known in the art and are used in existing printing systems. Any existing or new media registration device can be used as media registration device 155. Because the structure and function of such media registration devices are well known in the art, further detailed descriptions of such systems will be omitted.

[0040] The control system 130 includes processing circuitry for controlling the operation of the printing system 100. The processing circuitry may include one or more electronic circuits configured with logic for performing the various operations described herein. The electronic circuitry may include logic for performing the operations by including software instructions that perform the various operations executable by the circuitry, or by including dedicated hardware configured to perform the various operations, or any combination thereof. In examples where the logic includes software instructions, the electronic circuitry of the processing circuitry includes a memory device that stores the software and a processor that includes one or more processing devices capable of executing instructions, such as, for example, a processor, processor core, central processing unit (CPU), controller, microcontroller, system-on-chip (SoC), digital signal processor (DSP), graphics processing unit (GPU), etc. In examples where the logic of the processing circuitry comprises dedicated hardware, in addition to or instead of a processor, the dedicated hardware may include any electronic device configured to perform specific operations, such as an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Complex Programmable Logic Device (CPLD), a discrete logic circuit, a hardware accelerator, a hardware encoder, etc. The processing circuitry may also include any combination of dedicated hardware and general-purpose hardware with software.

[0041] The processing circuitry of control system 130 is configured with, among other things, media alignment logic 156. Media alignment logic 156 controls the operation of media alignment device 155. In particular, media alignment logic 156 controls where cross-process alignment data is located, and therefore where the media alignment device aligns the print media. Media alignment logic 156 controls the alignment of the print media so that either the leading edge or the trailing edge of the print media is aligned with one of the non-suction regions 151. In other words, the media alignment logic sets the cross-process alignment data to be at the boundary of or within the non-suction region 151, causing the media alignment device 155 to align either the leading edge or the trailing edge with the alignment data. In some embodiments, the trailing edge is aligned with the non-suction region 151. In some embodiments, the leading edge is aligned with the non-suction region 151. In some situations, it may be advantageous to align the trailing edge of the print medium with the non-suction region 151 because the trailing edge is less likely to lift the movable support surface 120 when located near or within the non-suction region 151. An example of an alignment scheme in which the trailing edge of the print medium is aligned with the non-suction region 151 is described in more detail below with respect to FIG.

[0042] In some embodiments, the media matching logic 156 may include additional matching schemes in addition to those described above and may switch between matching schemes based on user selection or based on detected conditions. For example, the matching scheme described above is designed to reduce image bleed and may therefore be used when a user selects settings that prioritize image bleed reduction, or if it is otherwise determined that image bleed reduction is needed based on detected conditions (e.g., based on real-time feedback of measured image bleed). Other matching schemes may be prioritized, such as by print speed, i.e., pages per minute. Switching between different media matching schemes is described in more detail below with reference to the embodiments of Figures 7A and 7B.

[0043] It should be understood that control system 130 may include two or more individual circuits or units, and that these individual circuits or units need not be coupled together or physically or logically connected. Thus, control system 130 may be a collection of different components, some of which may be located in one device or housing and others in other devices or housings. In other words, control system 130 includes all of the various circuits involved in controlling the operation of printing system 100, regardless of how those circuits are packaged or where they are located. For example, in some embodiments, processing circuitry physically located in the same device housing as media matching device 155 is programmed with media matching logic 156, while other processing circuitry of control system 130, such as a general-purpose processor or main controller of printing system 100, is located in a different portion of printing system 100. As another example, in some embodiments, the general-purpose processor or main controller of printing system 100 is configured with media matching logic 156.

[0044] Although not shown in FIG. 2 , in some embodiments, the airflow control system 150 may also block one of the upstream or downstream gaps associated with each print head 110 while leaving the other gap open. In particular, in embodiments where the trailing edge of the print medium is aligned with the non-suction region 151, then the upstream gap (i.e., the gap between the upstream face of the print head 110 and the edge of the opening 119) is blocked, while the downstream gap (i.e., the gap between the downstream face of the print head 110 and the edge of the opening 119) remains open. Conversely, in embodiments where the leading edge of the print medium is aligned with the non-suction region 151, then the downstream gap is blocked, while the upstream gap remains open. In some embodiments, the blocked gap may be blocked by a blocking member (e.g., blocking member 352) positioned above or within the corresponding gap to block the gap. In other embodiments, the blocked gap may be effectively blocked by being eliminated by positioning the print head 110 against (or very close to) the edge of the opening 119 on one side of it. For example, the upstream gap may be "blocked" by positioning the print head 110 against (or very near to) the upstream side of the opening 119. Thus, references in this specification and claims to "blocking" an upstream gap or a downstream gap should be understood to broadly encompass both blocking the gap using a blocking member, or effectively blocking the gap and positioning the print head 110 against or near the edge of the opening.

[0045] As noted above, non-suction areas are described as areas where suction is not provided. However, in some embodiments, non-suction areas can be replaced with reduced-suction areas, which are portions of the movable support surface where suction is not completely eliminated but instead significantly reduced compared to other portions of the movable support surface. For example, a reduced-suction area can be an area where the hole density and / or hole size in the movable support surface is significantly reduced compared to the remainder of the movable support surface. A significant reduction in suction through a non-suction area means a reduction of at least 50% or more, for example, by reducing the hole density or size by 50% or more. This reduction in the amount of suction in a reduced-suction area still has the effect of reducing the intensity at which cross-flow is induced, and as a result, is not as effective as in a non-suction area. Additionally, some hold-down force may still be applied if the print media accidentally overlaps the reduced-suction area. Other aspects described herein regarding non-suction areas, such as print media alignment, would still be applicable, except that a reduced-suction area replaces a non-suction area.

[0046] 3-7B, various embodiments of printing systems that may be used as printing system 100 are described.

[0047] Figures 3-5B illustrate a printing system 300 that may be used as the printing system 100 described above with reference to Figure 2. Figure 3 includes a schematic diagram showing a portion of the printing system 300 from a side view. Figure 4 includes a plan view from above of a portion of the printing system 300. In Figure 4, some components that are not otherwise visible because they are positioned below other components are shown with dashed or dotted lines. Figures 5A and 5B include cross sections of the printing system 300, with the cross section taken along line D in Figure 4.

[0048] 3, printing system 300 includes ink deposition assembly 301, media transport assembly 303, and air flow control system 350, which may be used as ink deposition assembly 101, media transport assembly 103, and air flow control system 150, respectively. Printing system 300 may also include additional components not shown in FIGS. 3-5B, such as a control system (e.g., control system 130).

[0049] In the printing system 300, the ink deposition assembly 301 includes four printhead modules 302, as shown in FIG. 3, each having three printheads 310, as shown in FIG. 4. As shown in FIG. 3, the printhead modules 302 are arranged in series along a process direction P above the media transport assembly 303, such that the print medium 305 is transported sequentially beneath each of the printhead modules 302. The printheads 310 are arranged to eject printing fluid (e.g., ink) through corresponding printhead openings 319 in corresponding carrier plates 311, with the bottom ends of the printheads 310 extending partway into the printhead openings 319. In this embodiment, as shown in FIG. 4, the printheads 310 are arranged in an offset pattern, with one of the printheads 310 being further upstream or downstream than the other two printheads 310 of the same printhead module 302. In other embodiments, a different number and / or arrangement of printheads 310 and / or printhead modules 302 is used.

[0050] In printing system 300, media transport assembly 303 includes a flexible belt that provides a movable support surface 320. As shown in FIG. 3 , movable support surface 320 is driven by rollers 329 to move along a looped path, a portion of which passes through ink deposition region 323 of ink deposition assembly 301. Additionally, in this embodiment, vacuum plenum 325 includes a vacuum platen 326 that forms a top wall of plenum 325 and supports movable support surface 320. Platen 326 includes platen holes 327 that allow fluid communication between the interior of plenum 325 and the underside of movable support surface 320.

[0051] In some embodiments, the platen hole 327 can include a channel on its top side, as seen in the enlarged cross-sectional view of FIG. 3, which can increase the opening area of ​​the hole 327 on its top side. Specifically, the platen hole 327 can include a bottom portion 327a that opens to the bottom side of the platen 326 and a top portion 327b that opens to the top side of the platen 326, with the top portion 327b being a different size and / or shape than the bottom portion 327a. For example, FIGS. 3-5E show an embodiment of the platen hole 327 in which the top portion 327b is a channel that is elongated in the process direction, while the bottom portion 327a is a through hole that is less elongated and has a smaller cross-sectional area (see enlargement D of FIG. 3 and the dashed line in FIG. 4). In some embodiments, multiple holes 327 can share the same top portion 327b; in other words, multiple bottom portions 327a can be connected to the same top portion 327b.

[0052] The holes 321 in the movable support surface 320 are positioned such that each hole 321 is aligned in the process direction (y-axis) with a corresponding collection of platen holes 327. Thus, as the movable support surface 320 moves across the platen 326, each hole 321 periodically moves over its corresponding platen hole 327, resulting in the holes 321 and platen holes 327 temporarily being vertically aligned (i.e., aligned in the z-axis direction). As the holes 321 move over their corresponding platen holes 327, the holes 321 and 327 define openings that fluidly couple the environment above the movable support surface 320 to the low-pressure conditions in the vacuum plenum 325, thus creating a vacuum suction through the holes 321 and 327. This suction creates a vacuum hold-down force on the print medium 305 when the print medium 305 is placed over the holes 321.

[0053] As shown in FIGS. 3-5B, the movable support surface 320 has non-suction regions 351. The non-suction regions 351 may be used as the non-suction regions 151 described above in connection with FIG. 2. The non-suction regions 351 may also be considered part of the airflow control system 350. In this embodiment, the non-suction regions 351 are formed as regions in the belt of the movable support surface 320 that do not have holes 321. Specifically, the non-suction regions 351 are regions in the belt where multiple rows of holes 321 have been omitted from their locations. In the example of FIGS. 4-5B, each non-suction region 351 corresponds to six (6) omitted rows of holes 321; however, in other examples, fewer or more rows of holes 321 may be omitted, making the non-suction regions 351 wider or narrower. The discussion of the non-suction regions 151 above is applicable to the non-suction regions 351, and therefore, redundant description will be omitted.

[0054] Airflow control system 350 also includes a media alignment device 355 that loads print media 305 onto and aligns print media 305 with respect to movable support surface 320. Media alignment device 355 is similar to media alignment device 155 described above. Airflow control system 350 also includes media alignment logic (not shown) for controlling the operation of media alignment device 355, which is similar to media alignment logic 156 described above. A control system (not shown) for printing system 300 is configured with media alignment logic in the same manner as described above with respect to media alignment logic 156.

[0055] As shown in FIGS. 3-5B, the printing system 300 is configured to register the print media 305 relative to the non-suction zones 351, as described above with respect to the non-suction zones 151. In the embodiment of FIGS. 3-5B, the trailing edge of the print media 305 is registered with the non-suction zones 351. Specifically, the trailing edge TE of each print media 305 is aligned with the downstream datum of one of the non-suction zones 351. Thus, as shown in FIGS. 4 and 5B, the suction zone 351 to which the print media 305_1 is registered overlaps with the inter-media zone 322 between the print media 305_1 and the next print media 305_2 being transported through the system. Depending on the size of the print media 305 used, the percentage of the inter-media zone 322 that overlaps with the non-suction zone 351 will vary. For example, if a longer print media 305 than shown in FIGS. 4 and 5B were used, the leading edge LE of the print media 305_2 could be located near the upstream boundary of the non-suction zone 351. Conversely, if a shorter print medium 305 than that shown is used, the leading edge LE of the print medium 305_2 will be further away from the upstream boundary of the non-suction region 351.

[0056] As shown in FIGS. 4-5B, the airflow control system 350 may also optionally include a blocking member 352 for blocking one of the gaps 309u or 309d. In the embodiment of FIGS. 4-5B, the trailing edge TE of the print medium 305 is aligned with the non-suction region 351, and therefore the blocking member 352 blocks the upstream gap 309u. In other embodiments, the leading edge LE of the print medium 305 is aligned with the non-suction region 351, and therefore the blocking member 352 blocks the downstream gap 309d. In still other embodiments, the blocking member 352 is omitted. The blocking member 352 is positioned above the corresponding gap 309u or 309d so as to contact or be proximate to the carrier plate 311 on one end and the print head 310 on the other end. Thus, the blocking member 352 blocks airflow through the corresponding gap 309u or 309d. References to "blocking" a gap, "preventing" air from flowing through the gap, or other similar references refer to creating a relatively high impedance state through the gap such that airflow through the gap is significantly reduced compared to a fully open state (e.g., where impedance is increased tenfold and / or airflow is reduced). Thus, blocking or blocking a gap and preventing airflow through the gap does not necessarily require a hermetic seal or strict elimination of all airflow. In FIG. 4 , blocking members 352 are located above the corresponding gap 309u or 309d, but in other embodiments, blocking members may be located below or within gap 309u or 309d. In FIG. 4 , one blocking member 352 is provided for each print head 310. In other embodiments, multiple print heads 310 may share the same blocking member 352. For example, a single blocking member may extend across a printhead module to cover both upstream gaps 309u of an upstream printhead 310, while a downstream printhead 310 has its own blocking member 352. As another example, a single blocking member may be provided for an entire printhead module 302, blocking the upstream gaps 309u of all printheads 310 in that module 302.

[0057] In some embodiments, blocking member 352 is omitted, and one of gaps 309u or 309d is eliminated entirely by positioning print head 310 against (e.g., in contact with) the edge of opening 319 on one side of it. For example, upstream gap 309u can be eliminated by positioning print head 310 against the upstream side of the edge of opening 319.

[0058] As described above, providing the non-suction region 351 on the movable support surface 320 and aligning the trailing edge of the print medium 305 with the non-suction region 351 reduces cross-flow (and therefore image smearing) near the trailing edge of the print medium 305. Furthermore, blocking the upstream opening 309u in conjunction with the aforementioned alignment of the print medium 305 with the non-suction region 351 reduces cross-flow (and therefore image smearing) near the leading edge of the print medium 305. These phenomena are described in more detail below with reference to Figures 5A and 5B.

[0059] 5A shows a situation in which the inter-media zone 322 is located beneath the print head 310, with the print head 310_1 printing on the print medium 305_1 near its trailing edge TE. In such a situation, if the countermeasures described herein were not used, then as described above with reference to FIG. 1A, the inter-media zone 322 would draw air from the downstream side of the print head, for example, through the downstream gap 309d of the print head 310_1, creating a cross flow that could cause image bleeding. However, because a non-suction area 351 is provided adjacent the trailing edge TE of the print medium 305_1, suction from the inter-media zone 322 is largely prevented, particularly near the trailing edge TE. Although there is a portion of the intermediate-media zone 322 having unobstructed holes 321 through which vacuum suction still flows, this unobstructed portion of the print head-medium zone 322 is relatively far from the downstream side of the print head 310_1 in the state shown in FIG. 5A , and therefore suction from this unobstructed portion of the inter-media zone has little or no effect on the area near the downstream side of the print head 310_1. Thus, cross-flow from the downstream side of the print head 310_1 is not induced, or if induced, is relatively weak. Thus, image bleed near the trailing edge TE of the print medium 305_1 is prevented or reduced.

[0060] Figure 5B shows another state in which the inter-media zone 322 has progressed further downstream from the state shown in Figure 5A, where print head 310_2 is printing on print medium 305_1 near its trailing edge TE, while print head 310_1 is printing on the following print medium 305_2 near its leading edge.

[0061] In the condition shown in Figure 5B, if the countermeasures described herein were not used, then as described above with reference to Figure 1A, the inter-media zone 322 would draw air from the downstream side of the print head 310_2, for example, through the downstream gap 309d of the print head 310_2, creating a cross-flow that could cause image bleeding near the trailing edge TE of the print medium 305_1. However, the non-suction area 351 is provided adjacent the trailing edge TE of the print medium 305_1, thereby preventing or reducing the cross-flow from the downstream side of the print head 310_2 for the same reasons as described above with reference to Figure 5A. Thus, image bleeding near the trailing edge TE is prevented or reduced.

[0062] 5B , if the countermeasures described herein are not used, then as described above with reference to FIG. 1D , the inter-media zone 322 would draw air from the upstream side of the print head 310_1, for example, through the upstream gap 309u of the print head 310_1, creating a cross-flow that could cause image bleeding near the leading edge LE of the print medium 305_2. However, because the upstream gap 309u of the print head 310_1 is blocked (e.g., by the blocking member 352), the cross-flow that would otherwise flow through the upstream gap 309u of the print head 310_1 is prevented. While some cross-flow may flow from the upstream side of the print head 310_1, for example, from the region upstream of the printhead module 302 to the inter-media zone 322, the strength of the upstream gap 309u can be reduced because the impedance between the upstream sides of the print head modules 302 is higher than the impedance that would exist between the upstream gap 309u and the inter-media zone 322 if the upstream gap 309u were not blocked. Additionally, because downstream gap 309d remains unobstructed, relief air 314 can flow through downstream gap 309d into the unobstructed portion of inter-media zone 322, as indicated by the dashed arrow in FIG. 5B . This relief air 314 offsets some of the suction from inter-media zone 322, thus increasing the pressure in the region above inter-media zone 322 compared to without relief air 314. This reduces the intensity with which air is drawn from other regions, such as from upstream of print head 310_1. Thus, the cross-flow, already weakened by the obstruction of upstream gap 309u, is further weakened by the presence of relief air 314 from downstream gap 309d. Thus, the cross-flow from upstream of print head 310 is reduced in intensity, preventing or reducing image bleed near leading edge LE of print medium 305_2.

[0063] FIG. 6 illustrates an embodiment of a printing system that includes a movable support surface 620. The movable support surface 620 can be used as the movable support surface 320 or the movable support surface 120 described above. FIG. 6 also illustrates an exemplary system for registering print media 605 on the movable support surface 620. This system can be used in any of the printing systems described herein. In particular, the media registration logic 156 of printing system 100 and / or the media registration logic of printing system 300 can be configured to register the print media similar to the example shown in FIG. 6.

[0064] In FIG. 6 , a plan view of a segment of movable support surface 620 is shown, and the segment is shown flat or planar. However, it should be understood that in practice, some portions (or all) of movable support surface 620 may be curved in the process direction rather than planar, and one end of movable support surface 620 may be coupled to the other end of movable support surface 620 to form a closed loop, such as movable support surface 320 shown in FIG. 3 . Movable support surface 620 includes holes 621 that allow vacuum suction to be communicated to print medium 605 to hold print medium 605 against movable support surface 620. Movable support surface 620 also includes non-suction regions 651, similar to non-suction regions 151 and 351 described above. Non-suction regions 651 can be regions of movable support surface 620 where no holes 621 exist or where existing holes 621 have been blocked.

[0065] As shown in Figure 6, the process direction alignment data Reg_P is parallel to the process direction P and is positioned near the outer side OS of the movable support surface. The outer edge OE of the print medium 605 is aligned with the process direction alignment data Reg_P. Thus, as shown in Figure 6, if different print media 605a-605d having different sizes are used, their respective outer edges OE will all be aligned with each other in the process direction, but their respective inner edges IE may not be aligned.

[0066] As shown in FIG. 6 , each non-suction region 651 has associated cross-process matching data (Reg_CP). In FIG. 6 , the cross-process matching data (Reg_CP) is aligned with the downstream boundary of the associated non-suction region 651, and the trailing edge (TE) of each printing medium 605 is aligned with one of the cross-process matching data (Reg_CP). Thus, the trailing edge (TE) of each printing medium 605 is adjacent to one of the non-suction regions 651. As shown in FIG. 6 , if different printing media 605a-605d having different sizes are used, their respective leading edges may be positioned differently relative to the non-suction region 651. For example, because printing medium 605d is shorter in the process direction than printing medium 605a, the leading edge of printing medium 605a is relatively closer to the next non-suction region 651 downstream of printing medium 605a, while the leading edge of printing medium 605d is relatively further from the next non-suction region 651 downstream of printing medium 605d.

[0067] In some embodiments, including the embodiment of FIG. 6 , the non-suction areas 651 are spaced apart in the process direction to accommodate all sizes of print media 605 that the printing system is configured to use. Specifically, the spacing between the suction areas 651 is set for each size of print media 605 so that when the trailing edge TE of the print media 605 is aligned with a non-suction area 651, the leading edge LE of the print media 605 does not fall within one of the non-suction areas 651. If the leading edge LE falls within a non-suction area 651, this could lead to lifting or curling of the leading edge LE from the movable support surface 620 because any portion of the print media 605 in the non-suction area 651 does not receive suction to hold it down. Therefore, in some embodiments, the spacing of the non-suction areas 651 can be controlled to prevent this from occurring. In FIG. 6 , four different print media 605a-605b are shown, each having a different size. As shown in FIG. 6 , the leading edge LE of each of these print media 605a-605d does not fall within the non-suction area 651.

[0068] One way to ensure that the above conditions are met is to extend the non-suction area 651 at least w maxThe distance is w max is the process direction width of the largest print media 605 that the printing system is configured to use. However, in some situations, this approach results in having a relatively large inter-media zone between print media when smaller print media are used, reducing the number of print media that can be printed per unit time.

[0069] Another approach to satisfying the above conditions is to define the non-suction area 651 as common and spaced apart by a distance equal to or slightly greater than w common is the process direction width that is most common (i.e., the most types of print media have this width or a similar width) or most commonly used (i.e., the most frequently used print media has this width) among the different sizes of print media 605 that the system is configured to use. Such spacing can make it possible to optimize the print speed (number of print media per unit time) for the most frequently used print size, while potentially sacrificing the print speed of some other, less common print sizes. For example, in the printing system of FIG. 6, it is expected that the most frequently used size of print media will be print medium 605a. Furthermore, in the printing system of FIG. 6, multiple sizes of print media have the same or similar width as print medium 605a (e.g., print medium 605b). Thus, in the example of FIG. 6, the non-suction regions 651 are spaced apart by a distance slightly greater than the width of print medium 605a. Therefore, because the width of the inter-media zone between adjacent sheets is relatively small, the print speed of print media 605a and 605b is very good. In contrast, print medium 605c has a relatively slow print speed due to the relatively large inter-media zone between adjacent sheets.

[0070] The spacing between the non-suction areas 651 is w maxIf the spacing is set to less than 1 / 2, as in FIG. 6, this can result in some of the larger print media overlapping one or more of the non-suction regions 651. For example, in FIG. 6, print medium 605c overlaps one of the non-suction regions 651. This overlap of the non-suction regions 651 is unlikely to cause any problems because a portion of print medium 605c does not experience any hold-down suction, and the unheld portion is in the middle of print medium 605c. In particular, the portion of print medium 605 not experiencing suction is very unlikely to lift the movable support surface 620 because other portions of the print medium surrounding it are actively being held down. Therefore, as long as the non-suction regions 651 are sufficiently far from the leading edge LE, there is unlikely to be any problems. In some examples, the spacing between non-suction regions 651 can be set so that any suction region 651 overlapped by print medium 605 is at least 10 mm, and in some embodiments, approximately 25 mm, from the leading edge LE.

[0071] Note that, as noted above, the inter-sheet distance can be set equal to or slightly greater than the various widths described above. One reason for making the distance slightly greater than these widths, rather than exactly equal to the widths, is to provide some margin of error to account for the possibility that the leading edge LE of the print medium 605 may be located slightly downstream from its nominal position. The location of the leading edge LE of the print medium 605 may deviate from its nominally expected position relative to the next non-suction region 651 due to factors such as variations in the actual spacing between the non-suction regions 651 from the nominally set spacing due to manufacturing tolerances, variations in the actual spacing between the non-suction regions 651 due to wear or expansion / contraction of the movable support surface 620 due to environmental conditions (e.g., temperature), and manufacturing tolerances in the media alignment device, which lead to unavoidable variations in the alignment location of the print medium 605 relative to the respective alignment data.

[0072] As discussed above, slight variations in the actual location of the print medium 605 relative to the non-suction region 651 in a real-world system are why, in some circumstances, it may be advantageous to align the trailing edge TE of the print medium 605 relative to the suction region 651 rather than aligning the leading edge LE of the print medium 605 relative to the non-suction region 651. If the trailing edge TE is positioned above the non-suction region 651, due to the variations discussed above or some other factor, the trailing edge TE is unlikely to lift off the movable support surface 620 even without air suction because the direction of movement of the print medium 605 tends to force the air around the print medium 605 down into the movable support surface 620. Furthermore, the trailing edge TE is unlikely to cause a jam even if it does lift off the movable support surface because it is likely to only be pressed down onto the movable support surface as the leading edge LE continues to be pulled forward. In contrast, if the leading edge LE were aligned with the non-suction region 651, inevitable variations in the location of the print media 605 relative to their nominal location could result in the leading edge LE being positioned above the non-suction region 651. This could cause the leading edge LE to lift the movable support surface 620, potentially resulting in curling of the print media or causing a jam. Nevertheless, while in some situations it may be advantageous to align the trailing edge TE with the non-suction region, in some embodiments the leading edge is aligned with the non-suction region.

[0073] In one embodiment, print medium 605a in FIG. 6 corresponds to a substrate measuring 8.5 inches by 11 inches, print medium 605b corresponds to a substrate measuring 8.5 inches by 14 inches, print medium 605c corresponds to a substrate measuring 14 inches by 17 inches, and print medium 605d corresponds to a substrate measuring 7 inches by 11 inches. In this embodiment, the spacing between the non-suction areas is approximately 230 mm (approximately 9.1 inches), and the width of each non-suction area is approximately 25 mm (approximately 1 inch). This allows various commonly used types of print media to be aligned with the non-suction areas 651 without the leading edge LE entering the non-suction areas 651, while also optimizing the printing speed of 8.5 inches by 11 inch substrates, which is one of the most commonly used types of print media 605. It should be understood that the principles described above and illustrated in FIG. 6 are applicable to other sizes of print media, other sizes of non-suction areas 651, and other spacings between the non-suction areas 651. Different systems may be optimized around different sizes of print media. For example, what is considered the most commonly used print medium may vary from one system to the next depending on the system's intended use case and / or intended geographic region in which the system may be commercialized. For example, a system intended for sale / use in a particular geographic region or field of use may not have suction areas configured based on print media commonly used in that region or field of use, while a system intended for sale / use in another region or field of use may have non-suction areas configured differently. As one example, 8.5-inch by 11-inch substrates may be more common in North America, while A3 and A4-sized substrates may be more common in Europe. As another example, a system intended primarily for use in home or office printing may use a different size range of print media and may have a different most common type of print media than a system intended primarily for use in industrial applications.

[0074] As noted above, in some embodiments, the printing system may be configured to select between different registration schemes based on different user settings or different detected conditions. Figures 7A and 7B illustrate such an example. Similar to Figure 6, Figure 7A illustrates a registration scheme in which the trailing edge of each print medium 705 is registered with one of the non-suction regions 751. This registration scheme is intended to combat image bleeding near the trailing edge and is therefore referred to herein as a bleed-optimized registration scheme. However, as already noted above, such a bleed-optimized registration scheme may result in a slightly lower printing speed (e.g., sheets per unit time) than would otherwise be possible.

[0075] In contrast, FIG. 7B illustrates a matching scheme in which printing speed takes priority over bleed reduction, referred to herein as a speed-optimized matching scheme. In the speed-optimized matching scheme, the cross-process matching data is arranged so that the leading edge of each print medium 705 is a predetermined distance from the trailing edge of the adjacent print medium 705. This results in an inter-media zone 722 having a predetermined width equal to the aforementioned distance. Importantly, in the speed-optimized matching scheme, the width of the inter-media zone 722 can be controlled independently of the size of the print medium 705, and the width can be set smaller than would be possible in a bleed-optimized matching scheme. In a bleed-optimized matching scheme, the width of the inter-media zone 722 is entirely defined by the fixed spacing between the non-suction region 751 and the width of the print medium 705. Therefore, in a bleed-optimized matching scheme, the width of the inter-media zone 722 cannot be selectively controlled, and the width can be relatively large if the selected print medium 705 is particularly narrow. However, with the speed-optimized matching scheme, the width of the inter-media zone 722 can be freely set regardless of the size of the print media 705, allowing for the use of a relatively small inter-media zone 722. For example, the smallest inter-media zone 722 that the printing system is designed to handle can be used. Using a smaller inter-media zone 722 allows more print media 705 to fit within the same given length of the movable support surface 720, thus increasing the number of print media 705 printed per given unit of time (assuming a constant speed for the movable support surface 720). For example, comparing FIGS. 7A and 7B shows that using the bleed-optimized matching scheme ( FIG. 7A ) five of the print media 705 fit within a given length of the movable support surface 720, corresponding to a printing speed of five media per given unit of time, while using the speed-optimized matching scheme ( FIG. 7B ) six of the print media 705 fit within the same length, corresponding to a printing speed of six media per given unit of time. The difference in printing speed between the bleed-optimized and speed-optimized matching schemes can vary from one type of printing media to the next.For example, if the print medium 705 has a width approximately equal to the spacing between the non-suction regions 751 (such as print media 605a and 605b in FIG. 6 ), the speed of the bleed-optimized matching scheme may be similar to that of the velocity-optimized matching scheme. However, if the print medium 705 is particularly narrow relative to the spacing between the non-suction regions 751 (such as print medium 605d from FIG. 6 ), or if the print medium 705 is wider than the spacing between the non-suction regions 751 (such as medium 605c in FIG. 6 ), there may be a significant increase in printing speed when switching from the bleed-optimized matching scheme to the velocity-optimized matching scheme. Of course, a drawback of the velocity-optimized matching scheme is that the bleed-reduction effect near the trailing edge is lost. In some situations, printing speed may take priority over such bleed-reduction effect, while in other situations the opposite may be true.

[0076] In some embodiments, the printing system may allow selection between several matching schemes, which may include, for example, a bleed-optimized matching scheme and a speed-optimized matching scheme as described above. In some embodiments, one of the matching schemes may be a default scheme, and another scheme may be selected as desired based on various factors related to a particular print job. In some embodiments, the printing system may be configured to provide feedback of the printing speed associated with each of the matching schemes in terms of the selected print medium to help determine which scheme is preferred under a given set of conditions.

[0077] In some embodiments, the selection of a matching scheme may be performed manually by a user, while in other embodiments, a control system of the printing system may automatically select between matching schemes based on detected conditions. For example, the control system may consider the location of the image content being printed and select a bleed-optimized scheme when the image is printed close to the trailing edge and a speed-optimized scheme when the image is not printed near the trailing edge. As another example, the control system may consider the type of image content being printed and select a bleed-optimized scheme when an image that is particularly sensitive to bleed, such as a barcode or thin line, is being printed. As another example, the control system may receive real-time feedback of the amount of image bleed in the printed image and switch from a speed-optimized scheme to a bleed-optimized scheme when the amount of detected bleed reaches a threshold. Bleed may be detected, for example, by acquiring an electronic image of the printed image (e.g., via an in-line scanner) and performing image processing on the detected bleed (e.g., detecting the edges of the inked area in the image and quantifying the amount of ink dots or dark pixels outside the edges). In some embodiments, in addition to the system automatically selecting a matching scheme, the system may also allow the user to manually select a matching scheme that, when selected, overrides the system-selected scheme.

[0078] The present specification and the accompanying drawings illustrating aspects and embodiments of the present invention should not be construed as limiting, and the claims define the protected invention. Various mechanical, compositional, structural, electrical, and operational changes can be made without departing from the spirit and scope of the specification and claims. In some instances, well-known circuits, structures, and techniques have not been shown or described in detail so as not to obscure the invention. Like numbers in two or more figures represent the same or similar elements.

[0079] Furthermore, the terms used herein to describe aspects of the present invention, such as spatial and relational terms, are selected to aid the reader in understanding embodiments of the present invention, but are not intended to limit the present invention. For example, spatial terms such as "beneath," "below," "lower," "above," "upper," "inboard," "outboard," "up," and "down" may be used herein to describe the orientation or spatial relationship of one element or feature to another element or feature, as shown in the figures. These spatial terms are used relative to the orientation shown in the figures and are not limited to a particular frame of reference in the real world. Thus, for example, the direction of "up" in a figure does not necessarily correspond to "up" in the world frame of reference (e.g., away from the Earth's surface). Furthermore, when different frames of reference are considered to be shown in the figures, the spatial terms used herein may need to be interpreted differently in the different frames of reference. For example, a direction referred to as "up" with respect to one of the figures may correspond to a direction referred to as "down" with respect to a different frame of reference that is rotated 180 degrees from the frame of reference of the figure. As another example, if a device is rotated 180 degrees in the world frame of reference compared to how it is shown in the figure, an item described herein as "above" or "over" a second item associated with the figure will be "below" or "beneath" the second item with respect to the world frame of reference. Thus, depending on which frame of reference is being considered, different spatial terms can be used to describe the same spatial relationship or direction. Furthermore, the poses of items shown in the figures are chosen for convenience of illustration and description, but in actual implementations, the items may be in different poses.

[0080] The term "process direction" refers to the direction parallel to and pointing in the same direction as the print media moves as it is transported through the deposition region of the ink deposition assembly. Thus, the process direction is the direction parallel to and pointing in the positive direction of the y-axis in the figures.

[0081] The term "cross-process direction" refers to a direction perpendicular to the process direction and parallel to the movable support surface. At any given point, there are two cross-process directions pointing in opposite directions: the "inner" cross-process direction and the "outer" cross-process direction. Thus, given the frame of reference shown in the figures, a cross-process direction is any direction parallel to the x-axis, including directions pointing in either a positive or negative direction along the x-axis. References to the "cross-process direction" herein should be understood as referring generally to any of the cross-process directions, rather than to one specific cross-process direction, unless otherwise indicated by context. Thus, for example, a statement that "the valve is movable in the cross-process direction" means that the valve can move inward, outward, or both.

[0082] The terms "upstream" and "downstream" may refer to a direction parallel to the process direction, with "downstream" referring to a direction facing the same direction as the process direction (i.e., the direction in which the print media is transported through the ink deposition assembly) and "upstream" referring to a direction facing opposite the process direction. In the figures, "upstream" corresponds to the negative y-axis direction and "downstream" corresponds to the positive y-axis direction. The terms "upstream" and "downstream" may also be used to refer to the relative locations of elements, with an "upstream" element being displaced upstream relative to a reference point and a "downstream" element being displaced downstream relative to a reference point. In other words, an "upstream" element is closer to the beginning of the path taken by the print media as it is transported through the ink deposition assembly (e.g., where the print media meets the movable support surface) than some other reference element. Conversely, a "downstream" element is closer to the end of the path (e.g., where the print media leaves the support surface) than some other reference element. The point of reference of other elements to which an "upstream" or "downstream" element is compared may be explicitly stated (e.g., "upstream of the print head") or may be inferred from the context.

[0083] The terms "inside" and "outside" refer to cross-process directions, with "inside" referring to one cross-process direction and "outside" referring to the cross-process direction opposite "inside." In the figures, "inside" corresponds to the positive x-axis direction and "outside" corresponds to the negative x-axis direction. The terms "inside" and "outside" also refer to relative locations, with "inside" elements displaced inwardly relative to a reference point and "outside" elements displaced outwardly relative to a reference point. The reference point may be explicitly stated (e.g., "inside the print head") or inferred from the context.

[0084] The term "vertical" refers to a direction perpendicular to the movable support surface in the deposition region. At any given point, there are two vertical directions pointing in opposite directions: an "upward" direction and a "downward" direction. Thus, considering the reference frame shown in the figure, a vertical direction is any direction parallel to the z-axis, including directions pointing in the positive direction of the z-axis ("up") or the negative direction of the z-axis ("down").

[0085] The term "horizontal" refers to a direction parallel to the movable support surface in the deposition region (or tangent to the movable support surface in the deposition region if the movable support surface is not flat in the deposition region). The horizontal direction includes the process direction and the cross-process direction.

[0086] The term "vacuum" has various meanings, ranging from the strict meaning of a space devoid of all matter to the more general meaning of a state of relatively low pressure. As used herein, the term "vacuum" is used in a general sense and should be understood to refer broadly to a state or environment in which air pressure is lower than some reference pressure, such as ambient or atmospheric pressure. The amount by which the pressure of a vacuum environment must be lower than the reference pressure to be considered a "vacuum" is not limiting and can be a small or large amount. Thus, "vacuum" as used herein may include, but is not limited to, states that can be considered a "vacuum" under the stricter sense of the term.

[0087] The term "air" has different meanings in different contexts, ranging from the strict meaning of the Earth's atmosphere (or a mixture of gases whose composition is similar to that of the Earth's atmosphere) to the more general meaning of any gas or mixture of gases. As used herein, the term "air" is used in a general sense and should be understood to refer broadly to any gas or mixture of gases. This may include, but is not limited to, the Earth's atmosphere, an inert gas such as one of the noble gases (e.g., helium, neon, argon, etc.), nitrogen (N2) gas, or any other desired gas or gas mixture.

[0088] Additionally, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context indicates otherwise. Also, the terms "comprises," "comprising," and "includes" specify the presence of stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups. Unless specifically stated otherwise, components described as coupled may be electrically or mechanically coupled, or indirectly coupled through one or more intermediate components. Mathematical and geometric terms are not necessarily intended to be used in accordance with their precise definitions unless the context of the description indicates otherwise, even though the terms also have precise definitions, because those skilled in the art will understand, for example, that substantially similar elements that function in a substantially similar manner may readily fall within the scope of the descriptive terms.

[0089] Elements and their associated aspects described in detail with reference to one embodiment may, wherever practical, be included in other embodiments in which they are not specifically shown or described. For example, if an element is described in detail with reference to one embodiment but not with reference to a second embodiment, the element may be claimed as being included in the second embodiment.

[0090] It should be understood that the specific examples and embodiments described herein are non-limiting, and modifications to structure, dimensions, materials, and methodology can be made without departing from the scope of the present teachings.

[0091] Other implementations in accordance with the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and embodiments be considered as exemplary only, and that the following claims be accorded the fullest breadth and scope thereof under applicable law, including equivalents.

Claims

1. 1. A printing system comprising: an ink deposition assembly including a printhead disposed to eject printing fluid into a deposition area of ​​the ink deposition assembly; A media transport assembly comprising: a movable support surface having an aperture therethrough; a media alignment device; and a vacuum suction source; the media alignment device is configured to place print media on the movable support surface and align the print media to a location on the movable support surface, each print media having a leading edge and a trailing edge; the media transport assembly is configured to hold the print media against the movable support surface by vacuum suction through the holes and transport the print media along a process direction through the deposition area; the movable support surface includes non-suction areas in which the vacuum suction is prevented, the non-suction areas extending across the movable support surface in a cross-process direction and distributed along the movable support surface in the process direction; a media transport assembly, each of the non-suction regions comprising a portion of the movable support surface that does not include any of the holes; a control system configured to cause the media alignment device to align the leading edge and the trailing edge of each of the print media with a respective one of the non-suction areas when defining upstream and downstream with respect to the process direction, wherein an upstream gap exists between an upstream face of the print head and a rim of a print head opening, and a downstream gap exists between a downstream face of the print head and the rim of the print head opening; the upstream gap is closed to the passage of airflow and the downstream gap is open to the passage of airflow, and the control system is configured to cause the media alignment device to align the trailing edge of each of the pieces of print media with a respective one of the non-suction areas; or A printing system, wherein the downstream gap is closed to the passage of air flow, the upstream gap is open to the passage of air flow, and the control system is configured to cause the media alignment device to align a leading edge of each of the printing media with a respective one of the non-suction areas.

2. The printing system of claim 1 , wherein the control system is configured to cause the media alignment device to align a trailing edge of each of the print media with a respective one of the non-suction areas.

3. 2. The printing system of claim 1, wherein the holes are arranged in rows in the process direction extending perpendicular to the process direction, and each non-suction area extends in the process direction a length at least equal to the length of an area occupied by two or more rows of the holes.

4. The printing system of claim 1 , wherein each non-suction region extends in the process direction a length at least equal to a length of the print head in the process direction.

5. 2. The printing system of claim 1, wherein each of the non-suction regions includes a respective portion of the movable support surface that includes a respective subset of the holes, and each of the holes located in any of the non-suction regions is blocked.

6. The printing system of claim 5 , wherein the holes are arranged in rows in the process direction extending perpendicular to the process direction, and each non-suction area includes at least two or more rows of holes.

7. The printing system of claim 6 , wherein each non-suction region extends in the process direction a length at least equal to a length of the print head in the process direction.

8. 1. A printing system comprising: an ink deposition assembly including a printhead disposed to eject printing fluid into a deposition area of ​​the ink deposition assembly; A media transport assembly comprising: a movable support surface having an aperture therethrough; a media alignment device; and a vacuum suction source; the media alignment device is configured to place print media on the movable support surface and align the print media to a location on the movable support surface, each print media having a leading edge and a trailing edge; the media transport assembly is configured to hold the print media against the movable support surface by vacuum suction through the holes and transport the print media along a process direction through the deposition area; a media transport assembly, the movable support surface including non-suction areas where the vacuum suction is prevented, the non-suction areas extending across the movable support surface in a cross-process direction and distributed along the movable support surface in the process direction; a control system configured to cause the media alignment device to align the leading edge and the trailing edge of each of the print media with a respective one of the non-suction areas when defining upstream and downstream with respect to the process direction, wherein an upstream gap exists between an upstream face of the print head and a rim of a print head opening, and a downstream gap exists between a downstream face of the print head and the rim of the print head opening; the upstream gap is closed to the passage of airflow and the downstream gap is open to the passage of airflow, and the control system is configured to cause the media alignment device to align the trailing edge of each of the pieces of print media with a respective one of the non-suction areas; or the downstream gap is closed to the passage of airflow, the upstream gap is open to the passage of airflow, and the control system is configured to cause the media alignment device to align a leading edge of each of the print media with a respective one of the non-suction areas; A printing system, wherein the control system is configured to change the media alignment device between a first alignment scheme that includes aligning each of the printing media against a respective one of the non-suction areas and a second alignment scheme that includes aligning the printing media so that a leading edge of each of the printing media is a predetermined distance from the trailing edge of a previous one of the printing media.

9. The printing system of claim 8 , wherein the control system is configured to select between the first and second matching schemes based on a user selection.

10. The printing system of claim 8 , wherein the control system is configured to select between the first and second matching schemes based on a detected condition.

11. 2. The printing system of claim 1, wherein the non-suction areas are sized and spaced apart in the process direction for each size of print media the printing system is configured to use such that when a trailing edge of the print media is aligned with one of the non-suction areas, a leading edge of the print media is not located in any of the non-suction areas.

12. the media transport assembly includes a vacuum platen supporting the movable support surface, the vacuum platen including platen holes communicating the vacuum suction to the movable support surface; The printing system of claim 1 , wherein the movable support surface comprises a belt configured to move over a surface of the vacuum platen.

13. 1. A method comprising: loading a print medium, the print medium including a leading edge and a trailing edge, onto a movable support surface of a media transport assembly of a printing system; the print medium is held against the movable support surface via vacuum suction through holes in the movable support surface; the movable support surface includes a non-suction area, and the vacuum suction is prevented in the non-suction area; the non-suction areas extending in a cross-process direction across the movable support surface and distributed in a process direction along the movable support surface; selecting a media registration scheme from a plurality of media registration schemes the printing system is configured to use, the plurality of media registration schemes including a first media registration scheme in which a trailing edge of each print medium is registered against one of the non-suction areas; registering the print media using the selected media registration scheme; transporting the print medium in a process direction via the movable support surface through a deposition area of ​​a print head of the printing system; ejecting a printing fluid from the print head to deposit the printing fluid onto the print medium at the deposition area; The method, wherein the plurality of media registration schemes includes a second registration scheme in which print media are registered so that a leading edge of each print media is a predetermined distance from a trailing edge of a previous print media.

Images