Airflow control in a printing system via media registration and related devices, systems and methods

Abstract

The present invention is entitled "Airflow control in a printing system via media registration and related devices, systems and methods". The present invention provides a printing system, which includes a print head for ejecting a printing fluid into a deposition area. A movable support surface such as a belt is used to transport the printing medium through the deposition area, wherein the printing medium is pressed against the movable support surface by vacuum suction through holes on the movable support surface. A media registration device loads the printing medium onto the movable support surface and registers the printing medium to the position of the movable support surface. The movable support surface includes non-suction areas, in which vacuum suction through the movable support surface is prevented. The non-suction areas 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 causes the media registration device to register each of the printing media relative to a corresponding one of the non-suction areas.

Description

Technical Field

[0001] Aspects of the present disclosure relate generally to inkjet printing, and more particularly to an inkjet printing system having a media transport assembly that utilizes vacuum suction to hold and transport print media. Related devices, systems, and methods are also disclosed. Background Art

[0002] In some applications, an inkjet printing system uses an ink deposition assembly having one or more print heads and a media transport assembly that moves a print medium (e.g., a substrate such as paper, packaging, or other substrate suitable for printing with ink) through an ink deposition area (e.g., an area below the print head) of the ink deposition assembly. The inkjet printing system forms a printed image on the print medium by ejecting ink from the print head onto the medium as the medium passes through the deposition area. In some inkjet printing systems, the media transport assembly utilizes vacuum suction to help press the print medium against a movable support surface (e.g., a conveyor belt, a rotating drum, etc.) of a transport device. The vacuum suction that presses the print medium 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 a side of the movable support surface opposite to the side that supports the print medium. The vacuum source creates a vacuum state in the vacuum plenum, thereby causing vacuum suction through an aperture in the movable support surface that is fluidly coupled to the vacuum plenum. When the print media is introduced onto the movable support surface, the vacuum suction creates a suction force that presses the print media against the movable support surface. A media transport assembly utilizing vacuum suction can allow the print media to remain firmly in place without slipping while being transported through the ink deposition area below the ink deposition assembly, thereby helping to ensure proper positioning of the print media relative to the printhead and, therefore, allowing images to be printed more accurately. The vacuum suction can also allow the print media to be flattened as it passes through the ink deposition area, which can also help improve the accuracy of the printed image and help prevent a portion of the print media from rising and hitting a portion of the ink deposition assembly and possibly causing a jam or damage.

[0003] One problem that may occur in an inkjet printing system that includes a media transport assembly that utilizes vacuum suction is that the air flow caused by the vacuum suction causes unexpected blurring of the image. In some systems, such blurring may occur in portions of the printed image that are close to the edge of the print medium, particularly in those portions near the leading edge or the trailing edge of the print medium in the transport direction (sometimes referred to as the process direction). During a print job, as the print medium is transported through the deposition area of ​​the ink deposition assembly, the print medium is spaced apart from one another on the movable support surface, and thus the portion of the movable support surface that is located between adjacent print media is not covered by any print medium. This area between adjacent print media is referred to herein as the inter-media area. Therefore, there are uncovered holes in the movable support surface that are adjacent to both the leading edge and the trailing edge of each print medium in the inter-media area. Because these holes are uncovered, the vacuum of the vacuum plenum causes airflow to pass through those uncovered holes. This airflow may deflect ink droplets and satellites as they flow from the print head to the substrate, and thus cause image blurring.

[0004] There is a need to improve the accuracy of drop placement in inkjet printing systems and reduce the hazy appearance of the final printed media product. There is also a need to solve the hazy problem in a reliable manner while maintaining the speed of printing and delivery to provide an efficient inkjet printing system. Summary of the invention

[0005] Embodiments of the present disclosure may solve one or more of the above problems and / or may exhibit one or more of the above desirable features.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 delivery assembly, and a control system. The ink deposition assembly includes a print head, which is arranged to eject a printing fluid to a deposition area of ​​the ink deposition assembly. The media delivery assembly includes a movable support surface, a media registration device, and a vacuum suction source, and the movable support surface has a hole passing through the movable support surface. The media registration device is configured to load the print medium onto the movable support surface and to register the print medium to the position of the movable support surface. The media delivery assembly is configured to press the print medium against the movable support surface by vacuum suction through the hole, and to transport the print medium through the deposition area along the process direction. The movable support surface includes non-suction areas that prevent vacuum suction, and these non-suction areas extend across the movable support surface in the cross-process direction and are distributed along the movable support surface in the process direction. The control system is configured to cause the media registration device to register each of the print media relative to a corresponding one of the non-suction areas.

[0007] According to at least one embodiment of the present disclosure, a method for conveying print media through a printing system includes: generating vacuum suction; and conveying the vacuum suction through one or more first areas of the ink deposition area of ​​the printing system through the movement of a movable support surface to apply a suction force. The method also includes preventing the vacuum suction from being conveyed through one or more second areas of the ink deposition area through the movement of the movable support surface. The method also includes: loading the print media onto the movable support surface so that the print media is pressed against the movable support surface by the suction force through the one or more first areas and is aligned relative to one of the second areas; conveying the print media through the ink deposition area via the movable support surface; and ejecting a printing fluid from a print head to deposit the printing fluid onto the print media in the deposition area.

[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 delivery assembly of a printing system. The print medium is pressed against the movable support surface via vacuum suction through holes on the movable support surface. The movable support surface includes non-suction areas, wherein vacuum suction is prevented in these non-suction areas. The non-suction areas extend across the movable support surface in a cross-process direction and are distributed along the movable support surface in the process direction. The method also includes selecting a media registration scheme from a plurality of media registration schemes that the printing system is configured to use, the plurality of media registration schemes including a first media registration scheme in which a rear edge of each print medium is registered with one of the non-suction areas in the non-suction areas. The method also includes: registering the print medium using the selected registration scheme; conveying the print medium through a deposition area of ​​a print head of the printing system in the process direction via the movable support surface; and ejecting a printing fluid from the print head to deposit the printing fluid onto the print medium in the deposition area. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0010] FIG. 1A to FIG. 1I Schematically illustrates airflow patterns relative to a printhead assembly, transport device, and print media during different stages of print media transport through an ink deposition area of ​​a conventional inkjet printing system, and the resulting blurring effects in the print media product.

[0011] Figure 2is a block diagram illustrating components of an embodiment of an inkjet printing system including an airflow control system.

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

[0013] Figure 4 is from Figure 3 A plan view of the printhead assembly of an inkjet printing system as seen from above.

[0014] FIG. 5A to FIG. 5B yes Figure 4 A cross-sectional view of an inkjet printing system, wherein the cross section is taken along Figure 4 The D in the figure is intercepted.

[0015] Figure 6 is a plan view from above of a movable support surface of an embodiment of a printing system.

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

[0017] As mentioned above, when the intermediary area is close to or under the printhead, the uncovered holes in the intermediary area can create cross-flows that can blow ink drops (large drops) and satellites (small drops) ejected from the printhead off-course and cause image blur. To better illustrate some of the phenomena that cause blurring problems, refer to FIG. 1A to FIG. 1I . Figure 1A , Figure 1D and Figure 1G The print head 10 is schematically shown printing on the print medium 5 close to the rear edge TE, the front edge LE and the middle portion of the print medium 5 respectively. Figure 1B , Figure 1E and Figure 1H They are shown respectively Figure 1A , Figure 1D and Figure 1G Enlarged views of area A, area B and area C. Figure 1C , Figure 1F and Fig. 1I An enlarged picture of a printed image is shown, the printed image comprising lines printed respectively close to the rear edge TE, the front edge LE and the middle portion of a sheet of paper.

[0018] like Figure 1A , Figure 1D and Figure 1GAs shown, the inkjet printing system includes a print head 10 and a movable support surface 20, the print head is used to eject ink through the opening 19 in the carrier plate 11 to the print medium 5 (for example, the print medium 5_1 and the print medium 5_2), and the movable support surface conveys the print medium 5 in the process direction P, which corresponds to the positive y-axis direction in the figure. The movable support surface 20 can move (for example, slide) along the top of the vacuum platen 26, and the vacuum environment is provided on the bottom side of the platen 26. The movable support surface 20 has a hole 21, and the vacuum platen 26 has a hole 27, and the hole 21 and the hole 27 are periodically aligned with the movement of the movable support surface 20 so as to expose the area above the movable support surface 20 to the vacuum below the platen 26. In the area where the print medium 5 covers the hole 21, the vacuum suction through the aligned hole 21 and the hole 27 generates a force that presses the print medium 5 against the movable support surface 20. However, little or no air flows through these covered holes 21 and holes 27 because they are blocked by the print medium 5. On the other hand, Figure 1A and Figure 1D As shown, in the inter-media area 22, the holes 21 and 27 are not covered by the print media 5_1, 5_2, and therefore the vacuum suction causes the air to be sucked out and flow downward through the holes 21 and 27 in the inter-media area 22. This produces a Figure 1A and Figure 1D The air flows indicated by the dashed arrows in FIG. 2 flow from the area around the print head 10 toward the uncovered holes 21 and holes 27 in the inter-media area 22 , with some of the air flows passing under the print head 10 .

[0019] exist Figure 1A , the print medium 5_1 is printed near its trailing edge TE, and thus the area where ink is currently ejected ("ink ejection area") (eg, Figure 1A The area A in the intermediary region 22 is located downstream of the intermediary region 22 (upstream and downstream are defined relative to the process direction P, which is the direction in which the print media is conveyed by the movable support surface 20). Therefore, some of the air drawn toward the intermediary region 22 will flow upstream through the ink ejection area A. More specifically, the vacuum suction from the intermediary region 22 reduces the area directly above the intermediary region 22, such as Figure 1A Region R 1 The pressure in the area downstream of the print head 10 is Figure 1A Region R 2 Maintain a higher pressure. This pressure gradient causes the air to flow upstream from area R 2 Flow to region R 1 , where the airflow traverses the region R 1 and region R 2The ink jetting area between Figure 1A Some of this air can be drawn out from the gap 9d between the downstream face of the print head 10 and the edge of the opening 19 through which the print head 10 ejects ink. Air currents such as these that cross the ink ejection region are referred to herein as cross flows 15. Figure 1A As shown, the cross flow 15 flows upstream, but in other cases, the cross flow 15 can flow in a different direction.

[0020] like Figure 1B As shown in the enlarged view A' of the enlarged view including the area A in FIG, when the ink is ejected from the print head 10 toward the medium 5, a main ink droplet 12 and a satellite ink droplet 13 are formed. The satellite droplet 13 is much smaller than the main droplet 12 and has less mass and momentum, and therefore the upstream cross-flow 15a tends to have a greater impact on the satellite droplet 13 than on the main droplet 12. Therefore, although the main droplet 12 can land on the print medium 5 near its intended deposition position 16 regardless of how the cross-flow 15 flows, the cross-flow 15 can push the satellite droplets 13 off the intended trajectory, causing them to land at an unintended position 17 on the medium 5, and the unintended position 17 deviates from the intended position 16. This can be seen in FIG. Figure 1C As can be seen in the actual printed image in , the denser / darker line portion is formed by the main droplets that are mainly deposited at their intended locations 16, while the smaller dots scattered away from the line are formed by satellite droplets that are blown away from the intended locations 16 to land in unintended locations 17, resulting in a blurred or smudged appearance of the printed line. It is worth noting that Figure 1C The blur in the image is asymmetrically biased toward the rear edge TE of the paper shown. This is because the cross flow 15 near the rear edge TE is mainly in Figure 1A and Figure 1B The inter-media region 22 may also cause other airflows, such as downstream airflows from the upstream side of the printhead 10, to flow in other directions, but these other airflows do not pass through the area currently ejecting ink in the illustrated scene and therefore do not cause image blur. Those airflows that only cross the ink ejection area are referred to herein as cross flows.

[0021] Figures 1D to 1F Another example of such blurring occurring is shown, but this time near the leading edge LE of the print medium 5_2. Figure 1C and Figure 1DAs shown, the reasons for blurring near the leading edge LE are similar to those described above with respect to the trailing edge TE, except that in the case of printing near the leading edge LE, the ink ejection area is now located upstream of the inter-media region 22. As a result, the cross-flow 15 across the ink ejection area now originates from the upstream side of the printhead 10, for example, from the region R 3 , and flows downstream to the region R of the inter-media region 22 where the uncovered holes are located adjacent to the front edge LE 4 For example, air can be sucked out from the gap 9u between the upstream face of the print head 10 and the edge of the opening 19 of the carrier plate 11. Figure 1E As shown in the enlarged view B' of the enlarged view including the ink ejection area B, in the case of printing near the leading edge LE, the satellite droplets 13 are blown downstream toward the leading edge LE (positive y-axis direction) of the print medium 5_2. Figure 1F As shown, such phenomena result in an asymmetric blurring biased toward the leading edge LE, where satellite droplets are deposited at unintended locations 17 relative to intended locations 16.

[0022] In contrast, Figure 1G as well as Figure 1H As shown in the enlarged view C' corresponding to the enlarged view of the ink ejection area C in FIG. 5 , when the print medium (e.g., the print medium 5_2) is printed in the middle portion farther from the rear edge TE and the front edge LE, there may be little or no cross flow 15 because the inter-media area 22 is too far from the print head 10 and the ink ejection area C to cause a large amount of airflow near the ink ejection area C. Because the cross flow 15 is less present or weaker farther from the edge of the print medium 5, the satellite droplets 13 in this area are less likely to be blown off course. Therefore, as shown in FIG. Figure 1H and Fig. 1I As shown, when printing is farther from the edge of the print medium 5_2, the satellite droplets land at a position 18 closer to the expected position 16, resulting in less image blur. Due to other factors that affect the satellite droplets, the deposition position 18 of the satellite droplets may still differ from the expected position 16, but the deviation is less than the deviation near the leading edge or the trailing edge, and therefore does not cause noticeable blur.

[0023] In addition, the embodiments disclosed herein can suppress some of the cross-flows in the cross-flows so as to reduce the resulting image blur that may occur. By suppressing the cross-flows, the droplets (including, for example, satellite droplets) ejected from the print head are more likely to fall closer to or fall at their expected deposition positions, and thus the amount of blur can be reduced. According to various embodiments, the movable support surface is provided with a plurality of non-suction areas that prevent suction from passing through the movable support surface. For example, in some embodiments, the hole passing through the movable support surface can be omitted in the non-suction area, or the existing hole can be blocked in the non-suction area using tape or other patching type materials and processes to prevent suction from passing through the hole. The non-suction area can extend across the movable support surface in the cross-process direction, and can be distributed at certain intervals along the process direction. According to various embodiments, the airflow control system disclosed herein can reduce or eliminate the cross-flow by controlling the registration of the print medium conveyed by the movable support surface, so that one of the front edge and the rear edge of each print medium is registered with a non-suction area in the non-suction area. Therefore, since the rear edge (or front edge) of each print medium is adjacent to one of the non-suction areas and there are no holes (or the holes are blocked) in the non-suction area, vacuum suction from the adjacent inter-media area that would otherwise cause airflow near the edge is reduced or eliminated. Therefore, when printing is performed near the rear edge (or front edge), the cross-flow intensity near the edge is reduced or eliminated. With the cross-flow near the rear edge (or front edge) of the print medium reduced or eliminated, ink droplets (including satellite droplets) are more likely to land on or closer to their intended deposition positions, and thus the amount of blurring near the edge of the print medium is reduced.

[0024] As described above, the registration of one of the edges of the print medium with the non-suction area reduces the image blurring near the edge, but for print media of smaller width, it does not necessarily reduce the image blurring near the opposite edge or across the process edge. Therefore, in some embodiments, in addition to registering one edge with the non-suction area, a gap is provided on one side of the print head, and no gap is provided on the other side of the print head (or if present, the gap is blocked) to prevent the image blurring near the edge of the print medium relative to the registered edge. For example, in some embodiments where the rear edge TE is registered with the non-suction area, a downstream gap is provided on the downstream side of the print head, and no upstream gap is provided (or if present, the upstream gap is blocked), which reduces the blurring near the front edge LE. On the contrary, in the embodiment where the front edge LE is registered with the non-suction area, an upstream gap is provided on the upstream side of the print head, and no downstream gap is provided (or if present, the downstream gap is blocked), which reduces the blurring near the rear edge TE. Therefore, by both registering the print medium with the non-suction area and providing the upstream / downstream gap as described above, image blurring near both the leading edge LE and the trailing edge TE can be reduced. The reason why providing the gap as described above reduces image blurring is described in more detail below.

[0025] It has been found that providing a downstream gap on the downstream side of the printhead, while omitting the upstream gap on the upstream side of the printhead (or blocking the upstream gap if present), reduces the amount of image blurring near the leading edge LE of the print media. This improvement is for two main reasons. First, the presence of the downstream gap allows beneficial release air to be drawn through the downstream gap into the inter-media area when the leading edge LE is below the printhead. For example, Figure 1D In the state shown, the released air 14 flows through the downstream gap 9d. This released air is beneficial because it offsets some of the negative pressure caused by the suction in the inter-media area, and this causes the strength of the air sucked out from other places around the printhead to be reduced, which reduces the strength of the cross flow being sucked under the printhead. Because the released air passing through the downstream gap reduces the strength of the cross flow when the leading edge LE is below the printhead, the amount of image blur near the leading edge LE is reduced. The second reason for improving image blur near the leading edge LE is that the omission or blocking of the upstream gap prevents the cross flow from being drawn downward through the upstream gap when the leading edge LE is below the printhead. Figure 1DAn example of such cross flow can be seen in , where some of the cross flow 15 is sucked downward through the upstream gap 9u. Omitting or blocking the upstream gap does not eliminate all cross flow occurring near the leading edge LE, but it does eliminate one major source of cross flow that may occur near the leading edge LE, and therefore it reduces the overall strength of the cross flow, and therefore reduces image blur near the leading edge LE. Thus, both the beneficial release air provided by the downstream gap and the blocking of cross flow through the upstream gap help reduce the amount of image blur that occurs near the leading edge.

[0026] Although providing a downstream gap while omitting or blocking the upstream gap tends to reduce image blur near the leading edge LE, it may also cause increased image blur at the trailing edge TE if no other countermeasures are taken. This is because the air flowing through the downstream gap, although it is a beneficial release air when the leading edge LE is located below the print head, becomes a cross flow when the trailing edge TE is located below the print head. Similarly, although omitting or blocking the upstream gap prevents some cross flow when the leading edge LE is located below the print head, this also prevents the provision of beneficial release air when the trailing edge TE is located below the print head. Therefore, if no other countermeasures are taken, the improvement of image blur at the leading edge LE by the above method may be at the expense of worsening image blur at the trailing edge TE. However, in an embodiment in which the trailing edge TE is aligned with the non-suction area, there is almost no suction from the inter-media area near the trailing edge TE, and therefore the above-mentioned deterioration of image blur near the trailing edge TE (due to the gap around the print head) does not occur. Thus, in some embodiments, registration of the trailing edge TE with the non-suction region is beneficially paired with providing an open downstream gap and omitting / blocking an upstream gap, thereby allowing for satisfactory reduction of image blur at both the trailing edge TE and the leading edge LE.

[0027] In contrast, if the open and blocked gaps are reversed (i.e., the upstream gap is opened and the downstream gap is omitted or blocked), this reduces the amount of image blur near the rear edge TE rather than the front edge LE. The reasons for such reduction in image blur are similar to those described above with respect to the front edge LE, except that the beneficial release air now comes from the upstream gap relative to the front edge LE, while the crossflow tends to come from the downstream gap. In addition, if no countermeasures are taken, the image blur at the front edge LE may be improved at the expense of worsening the image blur at the rear edge TE by providing an open upstream gap while omitting or blocking the downstream gap. However, in an embodiment in which the front edge LE is aligned with the non-suction area, there is almost no suction from the inter-media area near the front edge LE, and therefore the above-mentioned deterioration of the image blur near the front edge LE (due to the gap around the print head) does not occur. Therefore, in some embodiments, the alignment of the front edge LE with the non-suction area is beneficially paired with providing an open upstream gap and omitting / blocking the downstream gap, thereby allowing satisfactory reduction of image blur at both the rear edge TE and the front edge LE.

[0028] Now go to Figure 2 , an embodiment of the printing system will be described in more detail. In the drawings and descriptions herein, digital marks such as "_1", "_2", etc. are attached to the end of the figure numbers of some components. When there are multiple similar components and it is desired to reference a specific one of these components, the same basic figure number is used and different marks are attached to it to distinguish the various components. However, when the components are generally or commonly referenced without distinguishing specific components, the marks can be omitted from the basic figure number. Therefore, as an example, when it is desired to identify a specific one of the print media 5, the print medium 5 can be marked and referred to as the first print medium 5_1, as shown in Figure 1A, but in other cases where it is not desired to distinguish multiple print media 5, it can also be marked and simply referred to as the print medium 5. In addition, letters such as "a", "b", "u", "d", etc. are attached to the end of the figure numbers of some components.

[0029] Figure 2 1 is a block diagram schematically illustrating a printing system 100 that utilizes the above-described airflow control system. The printing system 100 includes an ink deposition assembly 101 for depositing ink on a print medium, a media transport assembly 103 for transporting the print medium through the ink deposition assembly 101, and a control system 130 for controlling the operation of the printing system 100. Each of these components of the printing system 100 is described in more detail below. In addition, various components of the printing system 100 participate in controlling the airflow around the printhead, and therefore these components may be collectively referred to as an 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 specific ink color, such as cyan, magenta, yellow, and black. Each printhead module 102 includes one or more printheads 110 that are configured to eject a printing fluid, such as ink, onto a print medium to form an image. Figure 2 , for simplicity, one printhead 110 is shown in the printhead module 102, but each printhead module 102 may include any number of printheads 110. 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, and the printheads 110 are arranged to eject their ink through the printhead opening 119. In some embodiments, the carrier plate 111 supports the printhead 110. In other embodiments, the printhead 110 is supported by other structures. As is known in the art, the printhead module 102 may also include additional structures and devices, such as ink supply lines, ink reservoirs, electrical connections, etc., to support and facilitate the operation of the printhead 110.

[0031] like Figure 2 As shown, the media transport assembly 103 includes a movable support surface 120, a vacuum plenum 125, a vacuum source 128, and a media registration device 155. The movable support surface 120 transports the print media through the deposition area of ​​the ink deposition assembly 101. The vacuum plenum 125 provides vacuum suction from the vacuum source 128 to one side (e.g., the bottom side) of the movable support surface 120, and the print media is supported on the opposite side (e.g., the top side) of the movable support surface 120. The holes 121 through the movable support surface 120 transmit the vacuum suction through the surface 120 so that the vacuum suction presses the print media against the surface 120. The media registration device 155 loads the print media onto the movable support surface 120 and registers the print media relative to various registration references.

[0032] The movable support surface 120 is movable relative to the ink deposition assembly 101, and thus when the movable support surface 120 moves, the print medium pressed against the movable support surface 120 is conveyed relative to the ink deposition assembly 101. Specifically, the movable support surface 120 conveys the print medium through a deposition area 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 under the printhead 110. The movable support surface 120 may include any structure that can be driven to move relative to the ink deposition assembly 101 and has holes 121 to allow vacuum suction to press the print medium, such as a belt, a drum, etc.

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

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

[0035] As described above, the purpose of the non-suction areas 151 is to reduce the amount of suction that occurs near the leading edge or trailing edge of the print medium, and in order to do this, the non-suction areas 151 each need to extend a sufficient width in the cross-process direction. Therefore, it should be understood that references to non-suction areas herein do not refer to the normal space that exists between adjacent holes 121 or between adjacent rows of holes 121 in the movable support surface. Instead, if the non-suction areas 151 were not present, each non-suction area 151 would extend far enough in the cross-process direction to occupy the space that would otherwise be occupied by at least multiple rows of holes 121. In other words, if the pitch (spacing) between adjacent rows of holes 121 in the cross-process direction is d 1 , then the width of the non-pumping region 151 in the cross-process direction is at least N·d 1 , where N is a number of 2 or greater. The specific width of the non-suction area 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 (a wider non-suction area may require a larger gap between print media), and the desired amount of blur reduction (to a certain extent, a wider non-suction area may reduce blur more). For a given system and a given set of design goals, the optimal width of the non-suction area 151 can be determined experimentally, for example, by testing different widths of the non-suction area 151 and measuring the amount of image blur for each different width. In some embodiments, the width of the non-suction area 151 in the cross-process direction may be equal to the width of the ink deposition area of ​​a single print head 110 in the cross-process direction. In some embodiments, the width of the non-suction area 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 area 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 area 151 can be at least 15 mm. In some embodiments, the width of the non-suction area 151 can be at least 25 mm.

[0036] The spacing between the non-suction zones 151 adjacent in the process direction can be any desired spacing. In some embodiments, the spacing is set to be roughly suitable for the print medium of one or more sizes that the printing system 100 is designed to use. For example, in an embodiment where the movable support surface 120 length is about 2060mm, the non-suction zones 151 are spaced apart by about 257mm (center to center distance), which can be conducive to the use of the print medium of various standard sizes. In some embodiments, the spacing between the non-suction zones is set to be suitable for the longest print medium that the system is designed to use. In some embodiments, the spacing between the non-suction zones 151 is uneven. For example, in some embodiments, the spacing between the non-suction zones can alternate between a small spacing (for example, corresponding to a print medium of minimum size) and a larger spacing.

[0037] As described above, the media registration device 155 loads the print media onto the movable support surface 120 and registers the print media relative to various registration datums, as is known to those skilled in the art. The process direction registration datums extend in the process direction and are fixed relative to the transport device 103 (see, e.g., Figure 4 , Figure 6 7). When each print medium is loaded onto the movable support surface 120, the edge of the print medium along the process direction is aligned with the process direction registration reference. In this document, the side of the media transport assembly 103 closest to the process direction registration reference Reg_P is referred to as the outer side of the media transport assembly 103, and the opposite side is referred to as the inner side. Figure 4 , the right side of the platen 326 is the exterior side. In implementation, the registration datum Reg_P can be located on either side of the media transport assembly 103, and thus the side of the media transport assembly 103 that is considered the exterior side will vary from system to system (or from time to time within the same system) depending on which side the print media happens to be registered to. In addition, a plurality of cross-process registration datums extend in the cross-process direction (see, e.g., Figure 6). Unlike the process direction registration datum, the cross-process registration datum moves with the movable support surface 120 in a fixed manner in the process direction. When each print medium is loaded onto the movable support surface 120, the edge of the print medium along the row in the cross-process direction (the leading edge LE or the rear edge TE) is aligned with one of the cross-process registration datums in the cross-process registration datums. Therefore, by registering each print medium to the process direction registration datum and one of the cross-process registration datums in the cross-process registration datums, accurate positioning and orientation of the print medium relative to the movable support surface 120 can be enforced, thereby allowing accurate printing of images on the print medium. As will be discussed in more detail below, in the embodiments disclosed herein, the cross-process datum is part of the non-suction area 151, which means that each cross-process datum is located at or within the boundary of one of the non-suction areas 151.

[0038] Note that the registration datum corresponds to a conceptually existing line or axis, but there is not necessarily a physical feature corresponding to the datum. For example, the process direction registration datum may correspond to a line at a certain distance from the edge of the movable support surface, but there is not necessarily any feature on the movable support surface representing the line.

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

[0040] The control system 130 includes a processing circuit system for controlling the operation of the printing system 100. The processing circuit system may include one or more electronic circuits configured with logic components for performing various operations described herein. The electronic circuit may be configured with logic components for performing operations by including dedicated hardware configured to perform various operations, including software instructions that can be executed by the circuit system to perform various operations, or any combination thereof. In examples where the logic components include software instructions, the electronic circuit of the processing circuit system includes a memory device and a processor, the memory device stores software, and the processor includes, for example, one or more processing devices capable of executing instructions such as a processor, a processor core, a central processing unit (CPU), a controller, a microcontroller, a system on a chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), etc. In examples where the logic components of the processing circuit system include dedicated hardware, in addition to or in place 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 processors and software.

[0041] The processing circuit system of the control system 130 is configured with a media registration logic component 156, etc. The media registration logic component 156 controls the operation of the media registration device 155. Specifically, the media registration logic component 156 controls the position of the cross-process registration reference, thereby controlling the position where the media registration device registers the print medium. The media registration logic component 156 controls the registration of the print medium so that the front edge or the rear edge of the print medium is registered with one of the non-suction areas 151. In other words, the media registration logic component sets the cross-process registration reference at or within the boundary of the non-suction area 151, and causes the media registration device 155 to align the registration reference with the front edge or the rear edge. In some embodiments, the rear edge is registered with the non-suction area 151. In some embodiments, the front edge is registered with the non-suction area 151. In some cases, it may be advantageous to align the trailing edge with the non-suction area because when the trailing edge of the print medium is located near or in the non-suction area 151, it is less likely to lift from the movable support surface 120. Figure 6 An example of a registration scheme in which the trailing edge of the print medium is registered with the non-suction area 151 is described in more detail.

[0042] In some embodiments, the media registration logic component 156 may include additional registration schemes in addition to those described above, and may switch between registration schemes based on user selection or based on detected conditions. For example, the above-described registration scheme is designed to reduce image blur, and therefore, this registration scheme can be used when a user selects a setting that prioritizes reducing image blur, or when it is otherwise determined that image blur relief may be needed based on detected conditions (e.g., based on real-time feedback of measured image blur). Other registration schemes may prioritize things such as print speed, i.e., sheets per minute. See below for more information. Fig. 7A and Figure 7B The embodiments describe switching between different media registration schemes in more detail.

[0043] It should be understood that the control system 130 may include more than one individual circuit or unit, and that the individual circuits or units need not be juxtaposed or physically or logically coupled together. Thus, the control system 130 may be a collection of different parts, some of which may be located in one device or housing, and other parts of which may be located in other devices or housings. In other words, the control system 130 includes all of the various circuits that participate in controlling the operation of the printing system 100, regardless of how the circuits happen to be packaged or where the circuits are located. For example, in some embodiments, processing circuitry physically located within the same device housing as the media registration device 155 is programmed with the media registration logic component 156, while other processing circuitry of the control system 130, such as a general processor or main controller of the printing system 100, is located in a different part of the printing system 100. As another example, in some embodiments, the general processor or main controller of the printing system 100 is configured with the media registration logic component 156.

[0044] Despite Figure 2110 , but in some embodiments, the airflow control system 150 can also block one of the upstream gap or the downstream gap associated with each print head 110 while leaving the other gap open. Specifically, in an embodiment in which the rear edge of the print medium is aligned with the non-suction area 151, 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 an embodiment in which the leading edge of the print medium is aligned with the non-suction area 151, the downstream gap is blocked, while the upstream gap remains open. In some embodiments, the gap to be blocked can be blocked by a blocking member (e.g., a blocking member 352) that is located above or in the corresponding gap to block the gap. In other embodiments, the gap to be blocked can be effectively blocked by placing the print head 110 against (or very close to) the edge of the opening 119 on one side thereof to eliminate the gap to be blocked. For example, the upstream gap can be "blocked" by positioning the print head 110 against (or very close to) the upstream side of the opening 119. Therefore, references to "blocking" an upstream gap or a downstream gap in this document and the claims should be understood to broadly cover both: using a blocking member to block the gap, or eliminating the gap by positioning the print head 110 against or near the edge of the opening to effectively block the gap.

[0045] In the above, non-suction area is described as the area where suction is not provided. However, in some embodiments, non-suction area can be replaced by the area that reduces suction, and these areas that reduce suction are parts of the movable support surface, and in these parts, compared with other parts of the movable support surface, suction is not completely eliminated but significantly reduced. For example, the area that reduces suction can be the area where the density of the holes in the movable support surface and / or the size of the holes are significantly reduced compared with the rest of the movable support surface. The suction that passes through the significant reduction of non-suction area means reducing at least 50% or more, for example, the density or size of the holes are reduced by 50% or more. The reduction of the amount of the suction in the area that reduces suction will still have the effect of reducing the intensity of causing cross flow, although it may not be as effective as non-suction area. In addition, in the case where the print medium just overlaps with the area that reduces suction, some pressing forces may still be applied. Other aspects (such as the registration of print media) described herein relative to the non-suction area will still be applicable, and the difference is that the area that reduces suction will replace the non-suction area.

[0046] Now go to Figures 3 to 7B , various embodiments of a printing system that may be used as the printing system 100 will be described.

[0047] Figures 3 to 5B A printing system 300 is shown, which can be used as a reference above. Figure 2 A printing system 100 is described. Figure 3 A schematic diagram showing a portion of printing system 300 from a side view is included. Figure 4 Included is a plan view from above of a portion of printing system 300. Figure 4 In the drawings, some components that are not originally visible in the view because they are located below other components are shown by dotted lines or dash-dot lines. Figure 5A and Figure 5B A cross section of the printing system 300 is included, wherein the cross section is taken along Figure 4 The D in the figure is intercepted.

[0048] like Figure 3 As shown, the printing system 300 includes an ink deposition assembly 301, a media delivery assembly 303, and an air flow control system 350, which can be used as the ink deposition assembly 101, the media delivery assembly 103, and the air flow control system 150, respectively. The printing system 300 may also include Figures 3 to 5B Additional components not shown, such as a control system (eg, control system 130).

[0049] In the printing system 300, the ink deposition assembly 301 includes Figure 3 The four print head modules 302 are shown, each of which has Figure 4 The three print heads 310 are shown. Figure 3 As shown, the print head modules 302 are arranged in series along the process direction P above the media delivery assembly 303, so that the print medium 305 is sequentially delivered under each of the print head modules 302. The print head 310 is arranged to eject the printing fluid (e.g., ink) through the corresponding print head opening 319 in the corresponding carrier plate 311, wherein the bottom side end of the print head 310 extends downward to the middle of the print head opening 319. In this embodiment, as shown in FIG. Figure 4 As shown, the printheads 310 are arranged in an offset pattern, wherein one of the printheads 310 is further upstream or downstream than the other two printheads 310 of the same printhead module 302. In other embodiments, different numbers and / or arrangements of printheads 310 and / or printhead modules 302 are used.

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

[0051] In some embodiments, the platen aperture 327 may include a channel on its top side, such as in Figure 3 As seen in the enlarged cross-sectional view of , this can increase the area of ​​the opening of the hole 327 on its top side. Specifically, the pressure plate hole 327 may include a bottom side portion 327a and a top side portion 327b, the bottom side portion leading to the bottom side of the pressure plate 326, and the top side portion leading to the top side of the pressure plate 326, wherein the top side portion 327b has a size and / or shape different from the bottom side portion 327a. For example, Figures 3 to 5B An embodiment of a platen hole 327 is shown in which the top side portion 327b is a channel elongated in the process direction, while the bottom side portion 327a is a through hole that is less elongated and has a smaller cross-sectional area (see Figure 3 The enlarged image D and Figure 4 In some embodiments, multiple holes 327 may share the same top side portion 327b, or in other words, multiple bottom side portions 327a may be coupled to the same top side portion 327b.

[0052] The holes 321 of the movable support surface 320 are arranged so that each hole 321 is aligned with a set of corresponding platen holes 327 in the process direction (y-axis). Therefore, when the movable support surface 320 moves across the platen 326, each hole 321 will periodically move over the corresponding platen hole 327, causing the hole 321 and the platen hole 327 to temporarily align vertically (i.e., align in the z-axis direction). When the hole 321 moves over the corresponding platen hole 327, the hole 321 and the hole 327 define an opening that fluidly couples the environment above the movable support surface 320 to the low pressure state in the vacuum plenum chamber 325, thereby generating vacuum suction through the hole 321 and the hole 327. If the print medium 305 is disposed over the hole 321, the suction generates a vacuum pressing force on the print medium 305.

[0053] like Figures 3 to 5B As shown, the movable support surface 320 has a non-suction area 351. The non-suction area 351 can be used as the above relative to Figure 2The non-suction areas 151 are described. The non-suction areas 351 can also be considered as part of the airflow control system 350. In this embodiment, the non-suction areas 351 are formed as areas of the strip of movable support surface 320 that do not have any holes 321. Specifically, the non-suction areas 351 are areas of the strip in which multiple rows of holes 321 have been omitted from where they were originally located. Figures 4 to 5B In the example of FIG. 1 , each non-suction region 351 corresponds to six (6) rows of holes 321 that have been omitted, but in other examples, fewer or more rows of holes 321 may be omitted, thereby making the non-suction region 351 wider or narrower. The above discussion of the non-suction region 151 is applicable to the non-suction region 351, and therefore a repeated description is omitted.

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

[0055] like Figures 3 to 5B As shown, the printing system 300 is configured to align the print medium 305 with the non-suction area 351, as described above with respect to the non-suction area 151. Figures 3 to 5B In the embodiment of the present invention, the rear edge of the print medium 305 is aligned with the non-suction area 351. Specifically, the rear edge TE of each print medium 305 is aligned with the reference on the downstream side of one of the non-suction areas 351. Figure 4 and Figure 5B As shown, the non-suction area 351 to which the print medium 305_1 is registered overlaps the inter-medium area 322, which is located between the print medium 305_1 and the next print medium 305_2 being transported through the system. Depending on the size of the print medium 305 used, the ratio of the overlap between the inter-medium area 322 and the non-suction area 351 will change. For example, if a ratio of Figure 4 and Figure 5BIf a longer print medium 305 than the one shown is used, the front edge LE of the print medium 305_2 can be positioned closer to the upstream boundary of the non-suction area 351. On the contrary, if a shorter print medium 305 than the one shown is used, the front edge LE of the print medium 305_2 will be further away from the upstream boundary of the non-suction area 351.

[0056] like Figures 4 to 5B As shown, the airflow control system 350 may also optionally include a blocking member 352 for blocking one of the gaps 309u or 309d. Figures 4 to 5B In some embodiments, the rear edge TE of the print medium 305 is aligned with the non-suction area 351, and thus the blocking member 352 blocks the upstream gap 309u. In other embodiments, the front edge LE of the print medium 305 is aligned with the non-suction area 351, and thus the blocking member 352 blocks the downstream gap 309d. In other embodiments, the blocking member 352 is omitted. The blocking member 352 is positioned above the corresponding gap 309u or 309d so that one end thereof is in contact with or in close proximity to the carrier plate 311 and the other end is in contact with or in close proximity to the print head 310. Thus, the blocking member 352 blocks airflow through the corresponding gap 309u or 309d. References to "blocking" the gap, "blocking" air from flowing through the gap, or other similar references refer to a relatively high impedance state generated by the gap, so that the airflow through the gap is significantly reduced (e.g., the impedance is increased tenfold and / or the airflow is reduced tenfold) compared to the fully open state. Therefore, blocking or plugging a gap and preventing airflow through the gap does not necessarily require a hermetic seal or strict elimination of all airflow. Figure 4 In the embodiment, the blocking member 352 is disposed above the corresponding gap 309u or 309d, but in other embodiments, the blocking member may be disposed below or within the gap 309u or 309d. Figure 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 the print head module to cover the upstream gaps 309u of two upstream print heads 310, while the downstream print head 310 has its own blocking member 352. For another example, a single blocking member may be provided for the entire print head module 302, and may block the upstream gaps 309u of all print heads 310 in the module 302.

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

[0058] As described above, providing the non-suction area 351 in the movable support surface 320 and registering the trailing edge of the print medium 305 with the non-suction area 351 reduces cross flow (and therefore image blur) near the trailing edge of the print medium 305. In addition, blocking the upstream opening 309u in combination with the aforementioned registration of the print medium 305 with the non-suction area 351 reduces cross flow (and therefore image blur) near the leading edge of the print medium 305. Figure 5A and Figure 5B These phenomena are explained in more detail.

[0059] Figure 5A 3 shows a state where the inter-media area 322 is located below the print head 310, where the print head 310_1 prints on the print medium 305_1 close to its rear edge TE. In this case, if the countermeasures described herein are not used, as described above with reference to Figure 1A As described above, the inter-media area 322 will suck air from the downstream side of the print head (e.g., through the downstream gap 309d of the print head 310_1), thereby generating a cross flow that may cause image blur. However, because the non-suction area 351 is set adjacent to the rear edge TE of the print medium 305_1, most of the suction from the inter-media area 322 (especially near the rear edge TE) is blocked. A portion of the inter-media area 322 has unblocked holes 321, and vacuum suction still flows through these holes, but this unblocked portion of the inter-media area 322 is blocked in the Figure 5A In the state shown, the downstream side of the print head 310_1 is relatively far away, and therefore the suction from the unblocked portion of the inter-media area has little effect on the area near the downstream side of the print head 310_1. Therefore, no cross flow from the downstream side of the print head 310_1 is caused, or if caused, the cross flow is relatively weak. Therefore, image blurring near the rear edge TE of the print medium 305_1 is prevented or reduced.

[0060] Figure 5B The dielectric inter-region 322 has been Figure 5AThe state shown is another state further downstream. In this state, the print head 310_2 is printing near the rear edge TE of the print medium 305_1, while the print head 310_1 is printing near the leading edge of the subsequent print medium 305_2.

[0061] exist Figure 5B In the state shown, if the countermeasures described herein are not used, as described above with reference to FIG. 1A , the inter-medium area 322 will suck air from the downstream side of the print head 310_2 (e.g., through the downstream gap 309d of the print head 310_2), thereby generating a cross flow that may cause image blur near the rear edge TE of the print medium 305_1. However, since the non-suction area 351 is provided adjacent to the rear edge TE of the print medium 305_1, the cross flow from the downstream side of the print head 310_2 is prevented or reduced for the same reasons as described above with respect to FIG. Figure 5A Therefore, image blurring near the rear edge TE is prevented or reduced.

[0062] In addition, Figure 5B If the countermeasures described in this article are not used, the Figure 1D As described, the inter-media region 322 will draw air from the upstream side of the print head 310_1 (e.g., through the upstream gap 309u of the print head 310_1), thereby generating a cross flow that may cause image blur near the leading edge LE of the print medium 305_2. However, because the upstream gap 309u of the print head 310 is blocked (e.g., by the blocking member 352), the cross flow that might otherwise flow through the upstream gap 309u of the print head 310_1 is prevented. Some cross flows may still flow from the upstream side of the print head 310_1 to the inter-media region 322, such as from the area upstream of the print head module 302, but blocking the upstream gap 309u reduces the strength of these cross flows because if the upstream gap 309u is not blocked, the impedance between the upstream sides of the print head module 302 is higher than the impedance that would exist between the upstream gap 309u and the inter-media region 322. Additionally, since the downstream gap 309d remains unblocked, the released air 314 is able to flow through the downstream gap 309d to the unblocked portion of the inter-media area 322, as shown in FIG. Figure 5B. The released air 314 counteracts some of the suction from the inter-media area 322, thereby increasing the pressure in the area above the inter-media area 322 relative to the case where the released air 314 would not exist. This reduces the strength of air sucked out from other areas (such as from upstream of the print head 310_1). Therefore, the cross flow that has been weakened by the blockage of the upstream gap 309u is further weakened by the presence of the released air 314 from the downstream gap 309d. Therefore, the strength of the cross flow from the upstream side of the print head 310 is reduced, and the image blurring near the leading edge LE of the print medium 305_2 is prevented or reduced.

[0063] Figure 6 FIG. 6 also shows an exemplary system for registering print media 605 on movable support surface 620. The system can be used in any of the printing systems described herein. Specifically, the media registration logic component 156 of the printing system 100 and / or the media registration logic component of the printing system 300 can be configured similarly to Figure 6 The example shown registers the print media.

[0064] exist Figure 6 , a plan view of a segment of a movable support surface 620 is shown, wherein the segment is depicted in a flat or planar state. However, it should be understood that in implementation, some (or all) of the movable support surface 620 may be curved in the process direction rather than planar, and one end of the movable support surface 620 may be coupled to the other end of the movable support surface 620 to form a closed loop, for example, as Figure 3 . The movable support surface 620 includes holes 621 through which vacuum suction is transmitted to the print medium 605 to press the print medium 605 against the movable support surface 620. The movable support surface 620 also includes a non-suction area 651 similar to the non-suction areas 151 and 351 described above. The non-suction area 651 can be an area of ​​the movable support surface 620 where no holes 621 exist or where existing holes 621 are blocked.

[0065] like Figure 6 As shown, the process direction registration reference 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 registered (aligned) with the process direction registration reference Reg_P. Figure 6As shown, when different printing media 605a to 605d having different sizes are used, their respective outer edges OE are aligned with each other in the process direction, but their respective inner edges IE may not be aligned.

[0066] like Figure 6 As shown, there is a cross-process registration reference Reg_CP associated with each of the non-pumping regions 651. Figure 6 , the cross-process registration datum Reg_CP is aligned with the downstream boundary of the associated non-suction area 651, and the rear edge TE of each print medium 605 is aligned with one of the cross-process registration datums Reg_CP. Therefore, the rear edge TE of each print medium 605 is adjacent to one of the non-suction areas 651. Figure 6 As shown, when different printing media 605a to 605d having different sizes are used, their respective front edges may be differently positioned relative to the non-suction area 651. For example, because the printing medium 605d is shorter than the printing medium 605a in the process direction, the front edge of the printing medium 605a is relatively close to the next non-suction area 651 downstream of the printing medium 605a, while the front edge of the printing medium 605d is relatively farther from the next non-suction area 651 downstream of the printing medium 605d.

[0067] In some embodiments (including Figure 6 In some embodiments, 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 non-suction areas 651 is set so that for each size of the print media 605, when the rear edge TE of the print media 605 is aligned with the non-suction areas 651, the front edge LE of the print media 605 does not fall within one of the non-suction areas 651. If the front edge LE falls within the non-suction area 651, this may cause the front edge LE to lift or curl 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 press it out. Therefore, in some embodiments, the spacing of the non-suction areas 651 can be controlled to avoid this situation. Figure 6 , four different print media 605a to 605b, each having a different size, are shown. Figure 6 As shown, the leading edge LE of each of these printing media 605 a to 605 d does not fall within the non-suction area 351 .

[0068] One way to ensure that the above conditions are met is to space the non-pumping areas 651 at least W apart in the process direction.最大 , where W 最大 is the width in the process direction of the largest print medium 605 that the printing system is configured to use. However, in some cases, when using smaller print media, this method can result in relatively large inter-media areas between print media, which reduces the amount of print media that can be printed per unit time.

[0069] Another method to meet the above conditions is to space the non-pumping areas 651 equal to or slightly longer than W. 常用 The distance W 常用 is the width in the process direction that is most commonly used among the different sizes of print media 605 that the system is configured to use (i.e., more types of print media have this width or a similar width) or the width in the process direction that is most commonly used (i.e., the print media that is most frequently used has this width). Such spacing can allow for optimizing print speed (higher amount of print media per unit time) for most print sizes and / or the most frequently used print sizes, while possibly sacrificing print speed for some other less commonly used print sizes. For example, in Figure 6 In the printing system of FIG. 1 , it is expected that the print medium of the size used most frequently will be print medium 605a. Figure 6 In the printing system of FIG. 1 , multiple sizes of print media have the same or similar width as print medium 605 a (eg, print medium 605 b). Figure 6 In the example of FIG. 6 , the non-suction areas 651 are spaced apart by a distance just slightly greater than the width of the print medium 605a. Therefore, the printing speed of the print media 605a and 605b is very good because the width of the inter-media area between adjacent sheets is relatively small. In contrast, the printing speed of the print medium 605c is relatively low because the inter-media area between adjacent sheets is relatively large.

[0070] When the interval between the non-suction areas 651 is set to be smaller than W 最大 When Figure 6 As shown, this will cause some of the larger print media to overlap with one or more non-suction areas 651. For example, in Figure 6In the embodiment of the present invention, the print medium 605c overlaps with a non-suction area in the non-suction area 651. Although this overlap of the non-suction area 651 causes a part of the print medium 605c not to experience any compression suction, since the uncompressed part is located in the middle of the print medium 605c, this is unlikely to cause any problem. Specifically, the part of the print medium 605 that does not receive suction is unlikely to be lifted from the movable support surface 620 because the print medium is actively compressed around the other parts of the part. Therefore, as long as the non-suction area 651 is far enough from the front edge LE, there is no possibility of any problem. In some examples, the spacing between the non-suction areas 651 can be set so that any non-suction area 651 overlapped by the print medium 605 is at least 10mm from the front edge LE, and in some embodiments is about 25mm from the front edge.

[0071] In the above, it should be noted that the distance between sheets of paper 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 these widths is to provide some margin of error to account for the possibility that the leading edge LE of the print medium 605 is positioned slightly farther downstream than its nominal position. The position of the leading edge LE of the print medium 605 can deviate from its nominal expected position relative to the next non-suction area 651 due to factors such as: changes in the actual spacing between the non-suction areas 651 compared to the nominal set spacing due to manufacturing tolerances; changes in the actual spacing between the non-suction areas 651 due to stretching or contraction of the movable support surface 620 caused by wear or environmental conditions (e.g., temperature); manufacturing tolerances of the media registration device causing inevitable changes in the registration position of the print media 605 relative to their corresponding registration references, etc.

[0072] As described above, slight variations in the actual position of the print medium 605 relative to the non-suction area 651 in the real system is one reason why it may be advantageous in some cases to align the rear edge TE of the print medium 605 with the non-suction area 651 without aligning the front edge LE of the print medium 605 with the non-suction area 651. If, due to the variations described above or due to some other factors, the rear edge TE is positioned above the non-suction area 651, this is unlikely to cause a problem because even if the rear edge TE is not subject to suction, it is unlikely to lift from the movable support surface 620 because the direction of movement of the print medium 605 causes the air surrounding the print medium 605 to tend to push the print medium 605 downward into the movable support surface 620. Furthermore, even if the rear edge TE does lift from the movable support surface, it is unlikely to cause a jam because as the front edge LE continues to be sucked forward, the rear edge TE will likely simply be pushed back onto the movable support surface. In contrast, if the leading edge LE is aligned with the non-suction area 651, the inevitable changes in the position of the print media 605 relative to their nominal position may cause the leading edge LE to be located above the non-suction area 651. This may potentially allow the leading edge LE to lift from the movable support surface 620, thereby potentially causing the print media to curl or cause a jam. However, although it may be advantageous to align the trailing edge TE with the non-suction area in some cases, in some embodiments, the leading edge is aligned with the non-suction area.

[0073] In one embodiment, Figure 6 The print medium 605a in corresponds to a substrate of 8.5 inches (in.) by 11 inches (in.) size, the print medium 605b corresponds to a substrate of 8.5 in. by 14 in. size, the print medium 605c corresponds to a substrate of 14 in. by 17 in. size, and the print medium 605d corresponds to a substrate of 7 in. by 11 in. size. In this embodiment, the spacing between the non-suction areas is about 230 mm (about 9.1 inches), and the width of each non-suction area is about 25 mm (about 1 inch). This allows various commonly used types of print media to be aligned with the non-suction area 651 without having their leading edges LE fall within the non-suction area 651, while also optimizing the printing speed of 8.5 in. by 11 in. substrates, which is one of the most commonly used types of print media 605. It should be understood that the above-mentioned and Figure 6The principle shown is applicable to other sizes of print media, other sizes of non-suction zones 651 and other spacings between non-suction zones 651. Different systems can be optimized around print media of different sizes. For example, the print media that is considered to be the most commonly used print media can vary from system to system, depending on the expected use case of the system and / or the expected geographic area in which the system can be commercialized. For example, a system intended to be sold / used in a specific geographic area or field of use may have a non-suction zone configured based on the print media commonly used in the area or field of use, while a system intended to be sold / used in other areas or fields of use may have non-suction zones with different configurations. For example, a substrate of 8.5in. by 11in. may be more common in North America, while a substrate of A3 and A4 size may be more common in Europe. For another example, a system that is mainly intended to be used for home or office printing may use print media of different range sizes and may have the most commonly used type of print media different from a system that is mainly intended to be used for industrial printing.

[0074] As described above, in some embodiments, the printing system can be configured to select between different registration schemes based on different user settings or different detected conditions. Fig. 7A and Figure 7B An example of this is shown in Fig. 7A , a registration scheme is shown in which the rear edge of each print medium 705 is registered with one of the non-suction areas 751, similar to Figure 6 This registration scheme aims to prevent image blurring near the rear edge and is therefore referred to herein as a fuzzy-optimized registration scheme. However, as already mentioned above, such a fuzzy-optimized registration scheme may result in a slightly lower printing speed (e.g., number of sheets per unit time) than would otherwise be possible.

[0075] In contrast, Figure 7B, a registration scheme is shown in which printing speed is prioritized over blur reduction, which is referred to herein as a speed-optimized registration scheme. In the speed-optimized registration scheme, the cross-process registration datum 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 the inter-medium region 722 having a predetermined width equal to the aforementioned distance. Importantly, in the speed-optimized registration scheme, the width of the inter-medium region 722 can be controlled independently of the size of the print medium 705, and the width can potentially be set to be smaller than the width possible in the fuzzy-optimized registration scheme. In the fuzzy-optimized registration scheme, the width of the inter-medium region 722 is completely defined by the fixed spacing between the non-suction regions 751 and the width of the print medium 705. Therefore, in the fuzzy-optimized registration scheme, the width of the inter-medium region 722 cannot be selectively controlled, and the width can be relatively large if the selected print medium 705 is particularly narrow. However, in the speed optimized registration scheme, because the width of the inter-media area 722 can be freely set without considering the size of the print media 705, a relatively small inter-media area 722 can be used. For example, the smallest inter-media area 722 that the printing system is designed to handle can be used. Using a smaller inter-media area 722 allows more print media 705 to fit within the same given length of the movable support surface 720, and thus increases the amount of print media 705 printed per given unit of time (assuming the speed of the movable support surface 720 is constant). For example, comparing Fig. 7A 7B, it can be seen that the fuzzy optimization registration scheme ( Fig. 7A ), five print media 705 are matched within a given length of the movable support surface 720, corresponding to the printing speed of the five media per given unit time, and a speed optimization registration scheme is used ( Figure 7B ), the six print media 705 are matched in the same length, corresponding to the printing speed of the six media per given unit time. The difference in printing speed between the fuzzy optimization registration scheme and the speed optimization registration scheme may vary depending on the type of print media. For example, if the width of the print medium 705 is approximately equal to the spacing between the non-suction areas 751 (such as Figure 6 605a and 605b in the non-pumping region 751), the speed in the fuzzy optimization registration scheme can be similar to the speed in the speed optimization registration scheme. However, for a print medium 705 (such as Figure 6 For a print medium 605d in the non-suction area 751 and for a print medium 705 wider than the spacing between the non-suction areas 751 (such as Figure 6When switching from the blur optimization registration scheme to the speed optimization registration scheme, the printing speed may be significantly improved. Of course, one disadvantage of the speed optimization registration scheme is that the blur reduction effect near the rear edge is lost. In some cases, printing speed may take precedence over such blur reduction effect, while in other cases, the opposite may be true.

[0076] In some embodiments, the printing system may allow selection among multiple registration schemes, which may include, for example, fuzzy optimized registration schemes and speed optimized registrations such as those described above. In some embodiments, one of the registration schemes may be a default scheme, and another scheme may be selected as needed based on various factors associated with a particular print job. In some embodiments, the printing system may be configured to provide feedback on the print speed associated with each of the registration schemes in view of the selected print medium to help determine which scheme may be preferred under a given set of conditions.

[0077] In some embodiments, the selection of the registration scheme may be made manually by a user, while in other embodiments, the control system of the printing system may automatically select between the registration schemes based on detected conditions. For example, the control system may consider the location of the image content to be printed, select a blur optimization scheme when the image is printed near the rear edge, and select a speed optimization scheme when the image is not printed near the rear edge. As another example, the control system may consider the type of image content being printed, and may select a blur optimization scheme when printing images that are particularly sensitive to blur (such as barcodes or thin lines). As another example, the control system may receive real-time feedback on the amount of image blur in the printed image, and may switch from a speed optimization scheme to a blur optimization scheme if the amount of blur detected reaches a threshold. For example, blur may be detected by: obtaining an electronic image of the printed image (e.g., via an online scanner); and performing image processing on the electronic image to detect blur (e.g., detecting the edge of an inked area in the image and quantifying the number of ink dots or dark pixels that fall outside the edge). In some embodiments, in addition to the system automatically selecting a registration scheme, the system may allow the user to manually select a registration scheme that overrides the system-selected scheme when selected.

[0078] This description and drawings illustrating aspects and embodiments of the invention should not be construed as limiting, and the claims define the protected invention. Various mechanical, compositional, structural, electrical and operational changes may be made without departing from the spirit and scope of the specification and claims. In some cases, well-known circuits, structures and techniques are not shown or described in detail to avoid obscuring the invention. The same numbers in two or more drawings represent the same or similar elements.

[0079] In addition, terms such as spatial terms and relational terms used herein to describe various aspects of the present invention are selected to help the reader understand the embodiments of the present invention, but are not intended to limit the present invention. For example, as shown in the accompanying drawings, spatial terms such as "under", "below", "lower", "above", "upper", "inside", "outside", "upward", "downward", etc. may be used herein to describe the direction or the spatial relationship of one element or feature to another element or feature. These spatial terms are used relative to the postures shown in the accompanying drawings and are not limited to a specific reference system in the real world. Thus, for example, the direction "upward" in the accompanying drawings does not necessarily correspond to "upward" in the world reference system (e.g., away from the surface of the earth). In addition, if a different reference system than that shown in the accompanying drawings is considered, the spatial terms used herein may need to be interpreted differently in the different reference system. For example, a direction referred to as "upward" relative to one of the accompanying drawings may correspond to a direction referred to as "downward" relative to a different reference system rotated 180 degrees from the reference system of the accompanying drawings. As another example, if the device is flipped 180 degrees in the world reference system compared to the device shown in the drawing, an item described herein as "above" or "over" a second item relative to the drawing would be "below" or "under" the second item relative to the world reference system. Thus, depending on the reference system being considered, different spatial terms may be used to describe the same spatial relationship or direction. In addition, the poses of the items shown in the drawings have been selected for ease of illustration and description, but in specific implementations during implementation, the items may have different poses.

[0080] The term "process direction" refers to a direction parallel to and pointing in the same direction as the axis along which the print medium moves as it is transported through the deposition area of ​​the ink deposition assembly. Thus, the process direction is a direction parallel to the y-axis in the drawings and pointing in the positive y-axis direction.

[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, namely an "inner" cross-process direction and an "outer" cross-process direction. Therefore, considering the reference system shown in the accompanying drawings, the cross-process direction is any direction parallel to the x-axis, including directions pointing in the positive or negative direction of the x-axis. Unless the context indicates otherwise, references herein to "cross-process direction" should be understood to refer generally to any cross-process direction, rather than to a specific cross-process direction. Thus, for example, the statement "the valve is capable of moving along the cross-process direction" means that the valve can move in an inner direction, an outer direction, or both directions.

[0082] The terms "upstream" and "downstream" may refer to directions parallel to the process direction, wherein "downstream" is a direction pointing in the same direction as the process direction (i.e., the direction in which the print medium is conveyed through the ink deposition assembly), and "upstream" is a direction pointing in the opposite direction to the process direction. In the accompanying drawings, "upstream" corresponds to the negative y-axis direction, while "downstream" corresponds to the positive y-axis direction. The terms "upstream" and "downstream" may also be used to refer to the relative position of elements, wherein an "upstream" element is displaced in the upstream direction relative to a reference point, and a "downstream" element is displaced in the downstream direction relative to a reference point. In other words, an "upstream" element is closer to the beginning of a path (e.g., where the print medium engages the movable support surface) than some other reference element, and the print medium takes the path as the print medium is conveyed through the ink deposition assembly. Conversely, a "downstream" element is closer to the end of the path (e.g., where the print medium leaves the support surface) than some other reference element. The reference point for other elements to which the "upstream" or "downstream" element is compared may be explicitly stated (e.g., "the upstream side of the print head"), or may be inferred from the context.

[0083] The terms "inner" and "outer" refer to cross-process directions, where "inner" refers to one cross-process direction and "outer" refers to the cross-process direction opposite to "inner". In the figures, "inner" corresponds to the positive x-axis direction and "outer" corresponds to the negative x-axis direction. The terms "inner" and "outer" also refer to relative positions, where "inner" elements are displaced in the inner direction relative to a reference point and "outer" elements are displaced in the outer direction relative to a reference point. Reference points can be explicitly stated (e.g., "inner side of the print head") or can be inferred from the context.

[0084] The term "vertical" refers to a direction perpendicular to the movable support surface in the deposition area. At any given point, there are two vertical directions pointing in opposite directions, namely, an "upward" direction and a "downward" direction. Therefore, considering the reference system shown in the accompanying drawings, a vertical direction is any direction parallel to the z-axis, including directions pointing in the positive z-axis direction ("upward") or the negative z-axis direction ("downward").

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

[0086] The term "vacuum" has different meanings in various contexts, ranging from a strict meaning of space without any matter to a more general meaning of a relatively low pressure state. In this article, the term "vacuum" is used in a general sense and should be understood to refer broadly to a state or environment in which the gas pressure is lower than a certain reference pressure such as ambient pressure or atmospheric pressure. The amount by which the pressure of a vacuum environment should be lower than the reference pressure to be considered a "vacuum" is not limited and can be a small amount or a large amount. Therefore, "vacuum" as used herein may include, but is not limited to, states that may be considered "vacuum" in the stricter sense of the term.

[0087] The term "air" has various meanings in various contexts, ranging from the strict meaning of the Earth's atmosphere (or a mixture of gases having a composition similar to the Earth's atmosphere) to a more general meaning of any gas or mixture of gases. In this document, 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 (N 2 ) gas, or any other desired gas or gas mixture.

[0088] In addition, unless the context indicates otherwise, the singular forms "a", "an", and "the / said" are intended to include the plural forms as well. Moreover, the terms "comprise", "contain", "include", etc. specify the presence of the specified features, steps, operations, elements, and / or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements, parts, and / or groups. Unless otherwise specifically stated, the parts described as being connected may be directly connected electrically or mechanically, or they may be indirectly connected via one or more intermediate parts. Unless the context of the description indicates otherwise, mathematical terms and geometric terms are not necessarily intended to be used according to their strict definitions, because those of ordinary skill in the art will understand that, for example, substantially similar elements that function in a substantially similar manner can easily fall within the scope of the descriptive term, even when the term also has a strict definition.

[0089] Elements and related aspects described in detail with reference to one embodiment may be included in other embodiments where they are not specifically shown or described when feasible. For example, if an element is described in detail with reference to one embodiment and is not described with reference to a second embodiment, the element may still be required to be included in the second embodiment.

[0090] It is to be understood that the particular examples and embodiments set forth herein are non-limiting and that modifications in structure, dimensions, materials, and methods may be made without departing from the scope of the present teachings.

[0091] By considering this specification and practicing the invention disclosed herein, other embodiments according to the present disclosure will be apparent to those skilled in the art. The specification and embodiments are intended to be considered exemplary only, and the following claims (including equivalents) are to be given their broadest rights under applicable law.

Claims

1. A printing system, comprising: an ink deposition assembly, the ink deposition assembly comprising a print head arranged to eject a printing fluid to an ink deposition area of ​​the ink deposition assembly; a media transport assembly including a movable support surface having an aperture therethrough, a media registration device, and a vacuum suction source, wherein the media registration device is configured to load the print media onto the movable support surface and register the print media to a position on the movable support surface, each of the print media having a leading edge and a trailing edge, wherein the media transport assembly is configured to press the print media against the movable support surface by vacuum suction through the apertures and to transport the print media through the ink deposition area in a process direction, and wherein the movable support surface comprises a non-suction area preventing the vacuum suction, the non-suction area extending across the movable support surface in a cross-process direction and distributed along the movable support surface in the process direction; as well as a control system configured to cause the media registration device to register the leading edge or the trailing edge of each of the print media relative to a corresponding one of the non-suction areas with an upstream gap between the upstream face of the print head and an edge of the print head opening and a downstream gap between the downstream face of the print head and the edge of the print head opening, and wherein: the upstream gap is blocked for passage of airflow and the downstream gap is opened for passage of airflow and the control system is configured to cause the media registration device to register the rear edge of each of the printing media with a corresponding one of the non-suction areas, or The downstream gap is blocked for passage of airflow and the upstream gap is opened for passage of airflow and the control system is configured to cause the media registration device to register a leading edge of each of the print media with a corresponding one of the non-suction areas.

2. The printing system according to claim 1, The control system is configured to cause the media registration device to align a rear edge of each of the printing media with a corresponding one of the non-suction areas.

3. The printing system according to claim 1, Each of the non-suction areas comprises a portion of the movable support surface that does not include any of the holes.

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

5. The printing system according to claim 3, Each non-suction area extends in the process direction over a length at least equal to the length of the print head in the process direction.

6. The printing system according to claim 1, Each of the non-suction areas comprises a corresponding portion of the movable support surface, the corresponding portion comprises a corresponding subset of the holes, and each of the holes located in any of the non-suction areas is blocked.

7. The printing system according to claim 6, The holes are arranged in the process direction in rows extending perpendicularly to the process direction, and each non-suction area comprises at least two or more rows of the holes.

8. The printing system according to claim 7, Each non-suction area extends in the process direction over a length at least equal to the length of the print head in the process direction.

9. The printing system according to claim 1, The control system is configured to cause the media registration device to switch between a first media registration scheme and a second media registration scheme, wherein the first media registration scheme includes aligning each of the printing media relative to a corresponding one of the non-suction areas, and the second media registration scheme includes aligning the printing media so that the leading edge of each of the printing media is a predetermined distance away from the rear edge of the previous printing medium of the printing media.

10. The printing system according to claim 9, Wherein the control system is configured to select between the first media registration scheme and the second media registration scheme based on a user selection.

11. The printing system according to claim 9, Wherein the control system is configured to select between the first media registration scheme and the second media registration scheme based on a detected condition.

12. The printing system according to claim 1, The non-suction areas are sized and spaced apart in the process direction such that, for each size of print medium that the printing system is configured to use, when the rear edge of the print medium is aligned with one of the non-suction areas, the front edge of the print medium is not located in any of the non-suction areas.

13. The printing system according to claim 1, wherein the media transport assembly includes a vacuum platen supporting the movable support surface, the vacuum platen including a platen aperture that transmits the vacuum suction to the movable support surface; and Wherein the movable support surface comprises a belt configured to move over a surface of the vacuum platen.

14. A method of conveying print media through a printing system according to any one of claims 1-8 and 12-13, the method comprising: loading print media onto the movable support surface of the media transport assembly of the printing system, wherein the print medium is pressed against the movable support surface via vacuum suction through holes in the movable support surface, wherein the movable support surface comprises a non-suction area, wherein the vacuum suction is prevented in the non-suction area, and wherein the non-suction zone extends across the movable support surface in a cross-process direction and is distributed along the movable support surface in a process direction; registering the trailing edge of the print medium with one of the non-suction areas; conveying the print medium via the movable support surface in a process direction through the ink deposition area of ​​the print head of the printing system; as well as Printing fluid is ejected from the printhead to deposit the printing fluid onto the print medium in the ink deposition area.

15. A method of conveying a print medium through a printing system according to any one of claims 9 to 11, the method comprising: loading a print medium onto the movable support surface of the media transport assembly of the printing system, the print medium including the leading edge and the trailing edge, wherein the print medium is pressed against the movable support surface via vacuum suction through holes in the movable support surface, wherein the movable support surface comprises a non-suction area, wherein the vacuum suction is prevented in the non-suction area, and wherein the non-suction zone extends across the movable support surface in a cross-process direction and is distributed along the movable support surface in a process direction; selecting a media registration scheme from a plurality of media registration schemes that the printing system is configured to use, the plurality of media registration schemes including the first media registration scheme in which the trailing edge of each print medium is registered with one of the non-suction areas; registering the print medium using the selected media registration scheme; conveying the print medium via the movable support surface in a process direction through the ink deposition area of ​​the print head of the printing system; as well as Printing fluid is ejected from the printhead to deposit the printing fluid onto the print medium in the ink deposition area.

16. The method according to claim 15, Wherein the plurality of media registration schemes include a second media registration scheme in which the print media are registered such that the leading edge of each print medium is a predetermined distance from the trailing edge of a previous print medium.

17. A method of conveying print media through a printing system according to any one of claims 1 to 13, the method comprising: Produce vacuum suction; transmitting the vacuum suction through movement of the movable support surface through one or more first regions of the ink deposition area of ​​the printing system to apply a suction force; preventing the vacuum suction from being transmitted through one or more second areas of the movable support surface moving through the ink deposition area; loading print media onto the movable support surface and registering the leading edge or the trailing edge of the print media relative to one of the second regions such that the print media is pressed against the movable support surface by the suction force through the one or more first regions; conveying the print medium through the ink deposition area via the movable support surface; as well as Printing fluid is ejected from the printhead to deposit the printing fluid onto the print medium in the ink deposition area.

Images