Printing system, movable support surface and method for printing system

Abstract

The present invention is entitled "Airflow control via self-closing holes on a movable support surface of a printing system, and related devices, systems and methods". A printing system includes an ink deposition assembly and a media transport assembly. The ink deposition assembly includes a print head, which is arranged to eject printing fluid to a deposition area of ​​the ink deposition assembly. The media transport assembly includes a vacuum source and a movable support surface. The movable support surface includes a valve having a hole through the media support surface. The media transport assembly is configured to hold one or more printing media on the movable support surface by vacuum suction, which is transmitted from the vacuum source through the valve. The valves are each configured to transition between a closed state and an open state, in which the airflow through the hole of the corresponding valve is blocked, and in the open state, the airflow through the hole of the corresponding valve is allowed.

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.

[0002] introduction

[0003] In some applications, an inkjet printing system uses an ink deposition assembly having one or more print heads and a media transport assembly to move a print medium (e.g., a substrate such as paper, envelopes, or other substrates suitable for printing with ink) through an ink deposition area (e.g., an area below the print head) of the ink deposition assembly. As the medium passes through the deposition area, the inkjet printing system forms a printed image on the print medium by ejecting ink from the print head onto the medium. In some inkjet printing systems, the media transport assembly utilizes vacuum suction to help hold the print medium on a movable support surface (e.g., a conveyor belt, a rotating drum, etc.) of a transport device. Vacuum suction to hold the print medium on 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 a side that supports the print medium. The vacuum source creates a vacuum state in the vacuum plenum, thereby causing vacuum suction through a hole in the movable support surface, which 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 holds the print media on the movable support surface. A media transport assembly utilizing vacuum suction can allow the print media to be securely held in place without slipping as it is transported through the ink deposition area beneath the ink deposition assembly, thereby helping to ensure proper positioning of the print media relative to the printhead and, therefore, more accurate printed images. The vacuum suction can also allow the print media to remain flat as it passes through the ink deposition area, which also helps to improve the accuracy of the printed image and helps prevent a portion of the print media from rising and hitting a portion of the ink deposition assembly and potentially causing a jam or damage.

[0004] One problem that may occur in an inkjet printing system that includes a media transport assembly that utilizes vacuum suction is the unexpected blurring of an image caused by the airflow caused by the vacuum suction. In some systems, such blurring may occur in portions of the printed image that are near the edge of the print medium, particularly those portions that are near the leading edge or trailing edge in the transport direction (sometimes referred to as the process direction) of the print medium. During a print job, when the print medium is transported through the deposition area of ​​the ink deposition assembly, the print medium is spaced apart from each other on the movable support surface, and thus portions of the movable support surface between adjacent print media are not covered by any print medium. This area between adjacent print media is referred to herein as the inter-media area. Therefore, near the leading edge and trailing edge of each print medium in the inter-media area, there are uncovered holes on the movable support surface. Since these holes are uncovered, the vacuum of the vacuum chamber causes air to flow through those uncovered holes. When ink droplets travel from the print head to the substrate, this airflow may deflect the drum, resulting in a blurred image.

[0005] There is a need to improve the accuracy of drop placement in inkjet printing systems and reduce blurring in the final printed media product. There is also a need to address the blurring problem in a reliable manner while maintaining printing and transport speeds to provide an efficient inkjet printing system. Summary of the invention

[0006] 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.

[0007] According to at least one embodiment of the present disclosure, a printing system includes an ink deposition assembly and a media transport assembly. 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 transport assembly includes a vacuum source and a movable support surface. The movable support surface includes a valve having an aperture through the media support surface. The media transport assembly is configured to hold one or more print media on the movable support surface by vacuum suction, which is transmitted from the vacuum source through the valve. The valves are each configured to transition between a closed state and an open state, in which the airflow through the aperture of the corresponding valve is blocked, and in which the airflow through the aperture of the corresponding valve is allowed in the open state.

[0008] According to at least one embodiment of the present disclosure, a movable support surface for a printing system includes a flexible belt and a plurality of valves arranged in the flexible belt to transmit vacuum suction through the flexible belt to hold a print medium transported by the movable support surface on the flexible belt. The valves are configured to transition between an open state and a closed state, in which the vacuum suction is transmitted through the corresponding valves and in which the vacuum suction is blocked through the corresponding valves.

[0009] According to at least one embodiment of the present disclosure, a method includes loading a print medium onto a movable support surface of a media transport assembly of a printing system, and holding the print medium on the movable support surface via vacuum suction through valves in the movable support surface. The method also includes causing those valves covered by the print medium to transition from a closed state to an open state via interaction between the print medium and the valve, in which the vacuum suction through the corresponding valve is blocked, and in which the vacuum suction through the corresponding valve is allowed, in which the vacuum suction through the corresponding valve is allowed. The method also includes transporting the print medium through a deposition area of ​​a print head of the printing system in a 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

[0010] 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:

[0011] Figures 1A to 1L Schematic illustration of airflow patterns relative to the printhead assembly, transport device, and print media during different stages of transporting the print media through the ink deposition area of ​​a conventional inkjet printing system, and the resulting blurring effects in the print media product.

[0012] Figure 2 is a block diagram illustrating components of one embodiment of an inkjet printing system including an air flow control system.

[0013] Figure 3 is a schematic diagram of an ink deposition assembly and a media transport assembly of one embodiment of an inkjet printing system.

[0014] Figure 4 is a top plan view of one embodiment of a movable support surface having a valve.

[0015] FIG. 5A to FIG. 5B yes Figure 4 A cross-sectional view of the movable support surface in FIG. Figure 4 The line A in is intercepted. DETAILED DESCRIPTION

[0016] In the drawings and descriptions herein, numerical indices such as "_1", "_2", etc. are attached to the ends of the reference numerals of some components. When there are multiple similar components and it is desired to refer to a specific component among those components, the same basic reference numeral is used and different indices are attached to distinguish the various components. However, when the components are referred to generally or as a whole without distinguishing the specific components, the index can be omitted from the basic reference numeral. Therefore, as an example, when it is desired to identify a specific print medium among the print media 5, the print medium 5 can be labeled and referred to as the first print medium 5_1, as shown in Figure 1, but in other cases where it is not desired to distinguish between multiple print media 5, it can also be labeled and simply referred to as print medium 5.

[0017] As described above, when the intermediary zone is close to or under the printhead, uncovered holes in the intermediary zone can create cross-flows that can blow satellite droplets off course and blur the image. Similarly, uncovered holes along the inside or outside of the print media can also create cross-flows that blur the image. To better illustrate some of the phenomena that cause blurring issues, refer to Figures 1A to 1F . Figure 1A , Figure 1D , Figure 1G and Figure 1J The print head 10 is schematically shown printing on the print medium 5 near the trailing edge TE, the leading edge LE, the inner edge and the middle of the print medium 5 respectively. Figure 1A , Figure 1D and Figure 1J is a cross section obtained through the print head 10 along the process direction (y-axis direction in the figure), and Figure 1G is a cross-section obtained through the same print head 10 along a cross-process direction perpendicular to the process direction (the x-axis direction in the figure), where Figure 1G The diagram in depicts an embodiment with three consecutive print heads along the x-direction, with one print head offset from the other two print heads. Figure 1B , Figure 1E , Figure 1H and Figure 1K They are shown respectively Figure 1A 、Figure AD、 Figure 1B and Figure 1J Magnified views of areas A, B, C, and D in FIG. Figure 1C , Figure 1F , Fig. 1I and Figure 1L Enlarged pictures of a printed image are shown respectively, the printed image comprising lines printed near the trailing edge TE, the leading edge LE, the inner edge and the middle of the paper.

[0018] like Figure 1A , Figure 1D , Figure 1G and Figure 1J As shown, the inkjet printing system includes one or more print heads 10 to eject ink to the print medium 5 through the print head opening 19 in the carrier plate 11. The inkjet printing system also includes a movable support surface 20 to transport the print medium 5 along the process direction P, which corresponds to the positive y-axis direction in the figure. The movable support surface 20 slides along the top of the vacuum platen 26, and a vacuum environment is provided on the bottom side of the platen 26. The movable support surface 20 has holes 21, and the vacuum platen 26 has platen holes 27. When the movable support surface 20 moves, the holes 21 and the holes 27 are periodically aligned, so that the area above the movable support surface 20 is exposed to the vacuum below the platen 26. In the area where the print medium 5 covers the holes 21, the vacuum suction through the aligned holes 21 and holes 27 generates a force that holds the print medium 5 on the movable support surface 20. However, since the holes 21 and holes 27 are blocked by the print medium 5, little or no air is sucked into these covered holes from the environment above the movable support surface 20. On the other hand, Figure 1A , Figure 1D and 1G As shown, in the dielectric inter-region 22 (see Figure 1A and Figure 1D ) and the uncovered area 24 near the inner side 1B of the pressure plate 26 (see Figure 1G ), holes 21 and holes 27 are not covered by the print medium 5, and therefore vacuum suction draws air from above the movable support surface 20 to flow downward through these holes 21 and holes 27. This creates an airflow, such as Figure 1A , Figure 1D and Figure 1G The dashed arrows in indicate that these airflows flow from the area surrounding the printhead 10 to the uncovered holes 21 and 27 in the inter-media area 22 and the uncovered area 24 , with some of the airflows passing under the printhead 10 .

[0019] exist Figure 1A , the print medium 5_1 is printed close to its trailing edge TE, and thus the area where ink is currently being ejected ("ink ejection area") (eg, Figure 1A The area A in the media inter-region 22 is located downstream (upstream and downstream are defined relative to the process direction P). Therefore, some of the air drawn into the media inter-region 22 will flow upstream through the inkjet area below the printhead 10. More specifically, the vacuum suction from the media inter-region 22 reduces the pressure in the area above the media inter-region 22, such as Figure 1A The area R1 in the print head 10 and the area downstream of the print head 10 (eg Figure 1A The pressure gradient causes air to flow from region R2 to region R1 in the upstream direction, wherein the air flow passes through the inkjet area between region R1 and region R2 (e.g., Figure 1AA portion of region A) in the inkjet area. Air flows such as these that pass through the inkjet area are referred to herein as cross flows 15. Figure 1A In some embodiments, the cross flow 15 flows upstream, but in other cases, the cross flow 15 may flow in different directions.

[0020] like Figure 1B As shown in the enlarged view A' in FIG. Figure 1A 1, as ink is ejected from the print head 10 toward the medium 5, a main drop 12 and satellite droplets 13 are formed. The satellite droplets 13 are much smaller than the main drop 12 and have less mass and momentum, and therefore the upstream cross-flow 15 tends to affect the satellite droplets 13 more than the main drop 12. Therefore, while the main drop 12 may land on the print medium 5 close to its intended deposition location 16 regardless of the cross-flow 15, the cross-flow 15 may push the satellite droplets 13 off the intended trajectory, causing them to land at an unintended location 17 on the medium 5 that is offset from the intended location 16. The results of such cross-flows and subsequent misaligned droplets can be seen in FIG. Figure 1C As can be seen in the actual printed image in , the denser printed dot region 16' corresponding to the intended printed line is formed by droplets (e.g., typically main droplets 12) that are primarily deposited at their intended locations, while the sparser dot region 17' that is dispersed away from the line is formed by droplets (e.g., typically satellite droplets 13) that are blown away from the intended location and landed at unintended locations. The printed line of the resulting image has a fuzzy or smudged appearance. It is noteworthy that Figure 1C The blur in the image is asymmetrically biased toward the trailing edge TE, which is the expected result of the cross-flow 15 near the trailing edge TE blowing mainly in the upstream direction. The inter-media region 22 may also cause other airflows flowing in other directions, such as downstream airflows from the upstream side of the printhead 10, but these other airflows do not pass through the area currently being jetted in the illustrated scene and therefore do not cause image blur. Only those airflows that pass through the jetting area are referred to herein as cross-flows.

[0021] Figures 1D to 1F Another situation where such blurring occurs is schematically shown, this time near the leading edge LE of the print medium 5_2. 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 inkjet area is now located upstream of the inter-media region 22. As a result, the cross-flow 15 across the inkjet area now originates from the upstream side of the print head 10 (e.g., from region R3) and flows downstream to region R4. Therefore, as Figure 1E As shown in the enlarged view B', it includes Figure 1DIn the case of printing close to the leading edge LE of the print medium 5_2, the satellite droplets 13 are blown toward the leading edge LE of the downstream print medium 5_2 (positive y-axis direction) to land at unintended locations 17, while the main droplets 12 tend to land at or near their intended locations 16. Figure 1F As shown, this effect results in an asymmetric blurring biased toward the leading edge LE of the print medium (ie, forming denser regions 16' of printed dots corresponding to lines, and sparser regions 17' of printed dots away from the lines toward the leading edge LE).

[0022] Figure 1G to Figure 1I Another situation where such blurring may occur is shown, this time near the inside edge IE of the print medium 5 due to uncovered holes 21 and holes 27 in that area. The reasons for causing blurring near the inside edge IE are similar to those described above with respect to the trailing edge TE and leading edge LE, except that in the case of printing near the inside edge IE, the inkjet area is now outside of the uncovered area 24 of holes 21 and holes 27 in the movable support surface 20 and platen 26. As a result, the cross-flow 15 across the inkjet area now originates outside of the print head 10 (e.g., from area R3) and flows in an inboard direction toward area R6. Thus, as shown in FIG. Figure 1H As shown in the enlarged view C', it includes Figure 1G In the enlarged view of the middle area C, when printing close to the inner edge IE, the satellite droplet 13 is blown inwardly toward the inner edge IE of the print medium 5 (positive y-axis direction) and falls at an unexpected position 17 instead of the expected position 16 where the main droplet 12 falls. Fig. 1I As shown, such a cross-flow pattern is expected to result in an asymmetric blurring biased toward the inner edge IE (ie, forming denser regions 16' of printed dots corresponding to lines, and sparser regions 17' of printed dots away from the lines toward the inner edge IE).

[0023] In contrast, Figure 1J and Figure 1K The enlarged view D' corresponds to Figure 1J As shown in the enlarged view of area D in FIG. 1 , when printing away from the edge (trailing edge, leading edge, or inside edge) of the print medium 105, there may be little or no cross flow 15 because the inter-media area 22 and the uncovered area 24 are too far away to cause a large amount of airflow. Because the cross flow 15 will be weaker or non-existent farther away 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 1K and Figure 1LAs shown, when printing away from the edge of the print medium 5, the satellite droplets land at the expected position 16 or a position 18 closer to the expected position 16, resulting in less image blur. Due to other factors affecting the satellite droplets 13, the deposition position 18 of the satellite droplets may still differ from the expected position 16 to some extent, but the deviation is less than the deviation near the leading edge or the trailing edge. Figure 1L Describes such Figure 1J and Figure 1K The resulting image of the situation in , thereby showing a printed line showing drops landing at the expected location 16 ', with some of the drops landing at the expected location 16 ' sufficiently close to the location 18 '. The resulting image does not show a significant obvious blur or smudged appearance of the line.

[0024] In addition, the embodiments disclosed herein can suppress some cross-flows in order to reduce the blurring of the image that may occur. By suppressing cross-flows, the droplets (including, for example, satellite droplets) ejected from the print head are more likely to fall to their expected deposition position or closer to their expected deposition position, and the amount of blurring can therefore be reduced. According to various embodiments, the airflow control system includes a plurality of valves arranged on a movable support surface, wherein each valve forms a closable hole or passage that transmits vacuum suction through the movable support surface. Each valve is arranged to close and open the corresponding hole based on whether the print medium is located above the valve. When the valve is not covered by the print medium, the valve is biased to close the hole, and conversely, the hole is opened when the hole is covered by the print medium. For example, in some embodiments, each valve can include a biased closing mechanism (e.g., a flexible reed) that can move between an open position and a closed position, in which the closing mechanism does not block the airflow through the hole, and in the closed position, the closing mechanism blocks the airflow through the hole. The valve is configured to bias the closing mechanism toward a closed position (e.g., by vacuum suction and / or spring force within the closing mechanism) such that the closing mechanism is moved to the closed position by the bias when the print medium is not located above the valve. The valve is also configured such that when the print medium is located above the valve, the closing mechanism is maintained in an open position by interaction with the print medium. Specifically, vacuum suction through the aperture pulls the print medium downward toward the reed, thereby pressing the reed toward the open position and overcoming the biasing force that pushes the reed to the closed position. In this manner, the movable support surface is configured to automatically prevent suction through any uncovered aperture by virtue of the valve, which is passively actuated to a desired state without the need for active control or an electric actuator (e.g., by a biasing element and by interaction with vacuum suction and the print medium). Since suction through the uncovered apertures is prevented, cross-flow caused by such uncovered apertures is reduced or eliminated. Because cross-flow near the trailing edge, leading edge and / or lateral edges (outer and / or inner edges) of the print medium is reduced or eliminated, ink droplets (including satellite droplets) are more likely to land at or closer to their intended deposition locations and thereby reduce the amount of blurring near such edges of the print medium.

[0025] Now turn to Figure 2 , one embodiment of the printing system will be described in more detail. Figure 2 1 is a block diagram schematically illustrating a printing system 100 utilizing 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.

[0026] The ink deposition assembly 101 includes one or more print head modules 102. For simplicity, Figure 2 One printhead module 102 is shown in FIG. 1 , but the ink deposition assembly 101 may include any number of printhead modules 102. 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 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 as a carrier plate 111 herein. The carrier plate 111 includes a printhead opening 119, and the printhead 110 is arranged to eject its 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 equipment for supporting and facilitating the operation of the printhead 110, such as ink supply lines, ink reservoirs, electrical connections, etc.

[0027] 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 loading / 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 valve 122 in the movable support surface 120 includes an aperture 121 that can transmit vacuum suction through the surface 120 when the corresponding valve is in an open state. The vacuum suction transmitted through the aperture 121 can press the print media against the surface 120. The media loading / registration device 155 loads the print media onto the movable support surface 120 and registers the print media relative to various registration data.

[0028] The movable support surface 120 is movable relative to the ink deposition assembly 101, so that when the movable support surface 120 moves, the print medium held on the movable support surface 120 is transported relative to the ink deposition assembly 101. Specifically, the movable support surface 120 transports the print medium through the deposition area of ​​the ink deposition assembly 101, which is the area where the printing fluid (e.g., ink) is ejected onto the print medium, such as the area under the printhead 110. The movable support surface 120 can 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 compact the print medium, such as a belt, roller, etc.

[0029] As described above, the movable support surface includes valves 122, and each valve 122 includes an aperture 121. The aperture 121 includes a passage through the movable support surface 120 that can fluidly couple an area below the movable support surface 120 to an area above the movable support surface 120. The aperture 121 can be opened and closed by a closing mechanism of the corresponding valve 122. The valves 122 are configured to transition between an open state and a closed state based on whether they are covered by a print medium. When the valve 122 is in the open state, vacuum suction is passed to the area above the movable support surface through the associated aperture 121, and when the valve is in the closed state, air flow is blocked through the aperture 121 and vacuum suction is not passed to the area above the movable support surface through the aperture 121. When the aperture 121 is not covered by the print medium, each valve 122 is biased to a closed state. On the other hand, when the print medium is located above the aperture 121, the associated valve 122 is maintained in an open state, in which air flow is allowed through the aperture 121 (and thus the vacuum suction from the air chamber 125 is transmitted through the aperture 121). The valve 122 located below the print medium is maintained in an open state by interaction with the print medium. In some embodiments, all valves 122 are maintained in an open state, for example, via contact with the print medium disposed above the valve 122 and / or contact with a roller (described below with respect to Figure 3 The embodiment further described in the drawings) is initialized to an open state by an externally applied force, and then those valves 122 covered by the print medium are maintained in the open state by interaction with the print medium located above the valves 122, while those valves 122 not covered by the print medium are transformed back to the closed state due to the biasing force.

[0030] Because each of the valves 122 is biased to a closed state when print media is not positioned over the corresponding valve 122, suction is automatically prevented through any apertures 121 that happen to be uncovered by print media. Since suction through uncovered apertures 121 is prevented, cross flow caused by such uncovered apertures 121 is reduced or eliminated. Thus, image blurring near the edge of the print media is reduced.

[0031] The vacuum plenum 125 includes baffles, walls, or any other structure arranged to enclose or define an environment of a vacuum state (e.g., a low pressure state) maintained by a vacuum source 128, wherein the 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 via the platen holes 127 through the vacuum platen 126. 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.

[0032] As described above, the media loading / registration device 155 loads the print media onto the movable support surface 120 and registers the print media relative to various registration data, as is familiar to those skilled in the art. For example, when each print medium is loaded onto the movable support surface 120, and one edge of each print medium can be registered to (e.g., aligned with) process direction registration data extending in the process direction (such as Figure 1GRegistration data Reg in the media transfer assembly 103). In this document, the side of the media transfer assembly 103 closest to the process direction registration data is referred to as the outside of the media transfer assembly 103, and the edge that is registered with the data is referred to as the outside edge, while the opposite side of the device is referred to as the inside, and the opposite edge is referred to as the inside edge. In practice, the registration data can be located on either side of the media transfer assembly 103, and the side of the media transfer assembly 103 that is considered to be the outside will vary from system to system (or different each time within the same system), depending on which side the print media happens to be registered to. In addition, when the print media is loaded thereon, the leading edge and / or trailing edge of the print media can be registered to various cross-process data along the movable support surface 120. Therefore, by registering each print medium to one of the process direction registration data and the cross-process registration data, 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. Various media loading 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 are used in existing printing systems. Any existing media loading device or any new media loading device may be used as the media loading / 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.

[0033] The control system 130 includes processing circuitry for controlling the operation of the printing system 100. The processing circuitry may include one or more electronic circuits configured with logic for performing the various operations described herein. The electronic circuitry may be configured with logic to perform the operations by means of dedicated hardware configured to perform the various operations, by means of software instructions that can be executed by the circuitry to perform the various operations, or any combination thereof. In examples where the logic includes software instructions, the electronic circuitry of the processing circuitry includes a memory device storing the software and a processor including one or more processing devices capable of executing the 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 of the processing circuitry includes dedicated hardware, 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., in addition to or in lieu of a processor. The processing circuitry may also include any combination of dedicated hardware and a general purpose processor and software.

[0034] Now turn to Figure 3, an embodiment of the printing system 300 will be described, which can be used as a reference above Figure 2 A printing system 100 is described. Figure 3 Included is a schematic diagram showing a portion of the printing system 300 from a side view. Figure 3 As shown, the printing system 300 includes an ink deposition assembly 301 and a media transport assembly 303, which can be used as the ink deposition assembly 101 and the media transport assembly 103, respectively. The printing system 300 may also include Figure 3 Additional components not shown, such as a control system (eg, control system 130).

[0035] like Figure 3 As shown, in the printing system 300, the ink deposition assembly 301 includes four printhead modules 302, wherein each printhead module 302 has a plurality of printheads 310. The printhead modules 302 are arranged in series along the process direction P above the media transport assembly 303, so that the print medium 305 is sequentially transported under each printhead module in the printhead modules 302. The printheads 310 are arranged to eject printing fluid (e.g., ink) through corresponding printhead openings 319 in corresponding carrier plates 311, respectively. In one embodiment, each printhead module 302 has three printheads 310, and the printheads 310 are arranged in an offset pattern, wherein two printheads 310 are aligned with each other in the cross-process direction, and the third printhead 310 is offset upstream or downstream from the other two printheads 310 ( Figure 3 Only two printheads 310 are visible in each module 302 because one of the printheads 310 is obscured by the other printhead 310 in this view). In other embodiments, different numbers and / or arrangements of printheads 310 and / or printhead modules 302 are used.

[0036] In printing system 300, media transport assembly 303 includes a flexible belt that provides a movable support surface 320. Figure 3 As 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. In addition, rollers 356 are provided to press the print medium against the movable support surface 320, which can facilitate the flat adhesion of the print medium 305 to the movable support surface 320. In addition, in this embodiment, the vacuum air chamber 325 includes a vacuum platen 326 that forms the top wall of the air chamber 325 and supports the movable support surface 320. The platen 326 includes platen holes 327 that allow fluid communication between the interior of the air chamber 325 and the underside of the movable support surface 320.

[0037] The movable support surface 320 includes a plurality of valves 322 which can be used as Figure 2 The valves 122 in the printing system 100 of the present invention are shown. Each valve 322 includes a hole 321 that fluidly connects an area below the movable support surface 320 to an area above the movable support surface, and a closing mechanism that closes and opens the hole 321. Therefore, the valve 322 and its corresponding hole 321 have an open state and a closed state. The holes 321 are arranged so that the outflow opening of each hole 321 (for example, on the bottom side of the movable support surface 320, opposite to the side supporting the print medium) is aligned with a set of corresponding platen holes 327 along 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, thereby causing the hole 321 and the platen hole 327 to be temporarily vertically aligned (i.e., aligned along the z-axis direction). When the hole 321 is in an open state and moves over the corresponding platen hole 327, the hole 321 and the platen hole 327 define an open passage that fluidly couples the environment above the movable support surface 320 to the low pressure state in the vacuum chamber 325, thereby generating vacuum suction through the hole 321 and the platen hole 327. The suction generates a vacuum pressing force on the print medium 305 disposed above the hole 321. When the hole 321 is in a closed state, the vacuum suction is prevented from being transmitted through the hole 321 regardless of whether the hole 321 is aligned with the platen hole 327.

[0038] Similar to the valve 122 described above, the valve 322 is configured to transition between an open state and a closed state based on whether the valve is covered by the print medium. The valve 322 is initialized to an open state (by an external force, further described below). As further described below, after being initialized to an open state, if the valve 322 is not covered by the print medium 305 due to a biasing force, the valve automatically transitions from the open state to the closed state. On the other hand, those valves 322 that are covered by the print medium remain in the open state by interacting with the print medium overcoming the biasing force.

[0039] More specifically, the valve 322 may include a closing mechanism (e.g., a flexible reed) that can move between an open position and a closed position, wherein the position of the closing mechanism controls whether the hole 321 of the valve 322 is in an open state or a closed state. The closing mechanism is biased to the closed position. The biasing force that biases the closing mechanism to the closed position may include a vacuum suction force that is applied to the closing mechanism due to the closing mechanism being exposed to vacuum suction from the air chamber 325. The biasing force may also include an internal structural force (e.g., a spring force) of the closing mechanism. When there is no print medium above a given valve 322, there is no reaction force to overcome the biasing force, and thus the closing mechanism moves to the closed position. On the other hand, when there is print medium above a given valve 322, the print medium interacts with the closing mechanism (e.g., presses against) and provides a reaction force to overcome the biasing force and hold the closing mechanism in the open position. The reaction force from the print medium may include the weight of the print medium 305 and the vacuum suction force applied to the print medium 305 via the open hole 321.

[0040] In some embodiments, the valves 322 may be initialized to an open state due to the weight of the print media pressing against the closure mechanism when the print media is loaded onto the movable support surface 320. In such embodiments, only those valves 322 that are directly below the print media are initialized to an open state, while the other valves may remain in a closed state.

[0041] However, in some embodiments, the weight of the print medium 305 alone may not be sufficient to overcome the biasing force to move the closure mechanism to the open position. Figure 3) is used to provide additional external force to help initialize the valve to the open position. As the movable support surface 320 (and any print media loaded thereon) passes beneath the roller 356, the roller 356 presses against the movable support surface 320 (either directly or via the print media, if present), and thereby applies a force to the closing mechanism of the valve 322. The force generated by the roller 356 pressing against the closing mechanism is sufficient to overcome the biasing force, and thus the closing mechanism moves to the open position as the valve passes over the roller 356. As described above, once a given valve 322 is initialized to the open position, the valve will remain in the open position or transition to the closed position based on whether there is print media 305 above the aperture 321. Even after there is no longer a pressing force from roller 356, the valves 322 located below the print medium remain in an open state despite the fact that the weight of the print medium is insufficient to overcome the biasing force, because once the holes 321 have been initially opened by roller 356, the vacuum suction from the vacuum chamber can now be transmitted through the open holes 321 to the print medium above the valves 321, and the vacuum suction interacts with the print medium to generate a suction force that pulls the print medium toward the movable support surface. This suction force on the print medium (combined with the weight of the print medium) is sufficient to overcome the biasing force and hold the valves in an open position. Therefore, immediately after passing roller 356, all valves 322 open, but shortly thereafter, all holes 321 covered by the print medium remain in an open state, while all holes 321 not covered by the print medium transition to a closed state 321.

[0042] Because the valves 322 automatically move to a closed state in the absence of print media 305 covering the apertures 321 associated with the valves 322, cross flow that would otherwise be caused through those apertures 321 is prevented. Thus, image blurring near the edge of the print media 305 is reduced or prevented. Additionally, because the apertures 321 covered by the print media 305 are in an open state, vacuum suction can be transmitted through those apertures 321 to apply a compressive force to the print media 305.

[0043] In some embodiments, such as in Figure 3 As can be seen in the enlarged cross-sectional view of , the platen hole 327 may include (coupled to) a channel on its top side, which may increase the opening area of ​​the platen hole 327 on its top side. Specifically, the platen hole 327 may include a through-hole portion 327a leading to the bottom side of the platen 326 and a channel portion 327b leading to the top side of the platen 326, wherein the channel portion 327b is extended along the process direction. In some embodiments, multiple through-hole portions 327a may be coupled to the same channel portion 327b.

[0044] The media transport assembly 303 also includes a media loading / 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 loading / registration device 355 is similar to the media loading / registration device 155 described above and can be used as the media loading / registration device described above. In some embodiments, the roller 356 can be part of the media loading / registration device 355.

[0045] Figures 4 to 5B Embodiments of valves that may be used with a movable support surface according to various embodiments of the present disclosure are shown. Figure 4 is a detailed perspective view of valve 422 as viewed from above valve 422. Figure 5A and Figure 5B Including along Figure 4 A cross section taken along line A in Figure 5A The valve 422 is shown in a closed state, and Figure 5B The valve 422 is shown in an open state. In some embodiments, as Figure 4 The valve 422 is formed within the movable support surface 420, and portions of the valve 442 are formed from the material of the movable support surface 420. In other embodiments (not shown), the valve 442 may be formed as a separate structure that may be joined to the movable support surface 420. Figures 4 to 5B In the following description, various layers 428 to 432 are shown and described as separate layers to facilitate understanding. However, in reality, layers 428 to 432 may be indistinguishable from one another in the finished product due to being joined together or manufactured together as a whole. In other words, in some embodiments, valve 422 is formed from separately identifiable layers, which may include layers 428 to 432, but in other embodiments, valve 422 may be formed in a material without identifiable layers, in which case layers 428 to 432 as described herein should be understood to refer to different portions (e.g., depths) of the material. In some embodiments, layers 428 to 432 are also part of movable support surface 420. For convenience, it is assumed in portions of the following description that layers 428 to 432 are part of movable support surface 420, but this is not limiting. In Figure 4 In FIG. 4 , the top layer 428 of the valve 422 (and in some embodiments, the top layer of the movable support surface 420 as well) is transparent to allow other components to be visible.

[0046] like Figures 4 to 5BAs shown, valve 422 includes an aperture 421 that forms a passage through valve 422 and through a movable support surface 420 in which valve 422 is disposed. Aperture 421 includes a top aperture portion 435 that defines a passage to the top side (the side facing the print medium) of movable support surface 420 and a bottom aperture portion 427 that is offset from the top aperture portion 435, the top aperture portion defining a passage to the bottom side (the side facing the vacuum platen / vacuum chamber) of movable support surface 420. Top aperture portion 435 may be formed in layers 428 and 429, while bottom aperture portion 427 is formed in layers 430 to 432. The aperture also includes a chamber 434 formed in layers 430 and 431, wherein top aperture portion 435 is fluidly coupled to chamber 434 (assuming that reed 423, described in more detail below, is in an open position). The bore 421 also includes one or more channels 426 formed in the layer 429, which are fluidly coupled at one end to the bottom bore portion 427 and at the other end to the chamber 434 (again assuming that the reed 423 is in the open position). Thus, the top bore portion 435 is fluidly coupled to the bottom bore portion 427 via the chamber 434 and the channels 426 (again assuming that the reed 423 is in the open position), and thus the bore 421 can fluidly couple the area below the valve 422 to the area above the valve 422.

[0047] As mentioned above, in Figure 4 In the embodiment, the top layer 428 is omitted / made transparent to show the features below the top layer 428. Except in the area corresponding to the top hole portion 435, the top layer 428 covers Figure 4 Each of the components shown has a top layer 428 having a hole that forms part of a top hole portion 435. Figure 4 , the bottom hole portion 427 is offset from the top hole portion 435 along the process direction (y-direction), and thus the channel 426 extends along the process direction, but this is a non-limiting example, and in other embodiments, the valve 422 and / or hole 421 can be oriented in any manner.

[0048] As described above, valve 422 also includes a flexible reed 423 located in chamber 434 below top hole portion 435. Reed 423 forms a closing mechanism for valve 422 and is capable of being in a closed position (see Figure 5A ) and open position (see Figure 5B). In the closed position, the reed 423 is positioned at the boundary between the top hole portion 435 and the chamber 434, and thus the reed 423 blocks the airflow between the chamber 434 and the top hole portion 435. In addition, in the closed position, the reed 423 is positioned at the boundary between the chamber 434 and the passage 426, and thus the reed 423 blocks the airflow between the chamber 434 and the passage 426. Therefore, when the reed 423 is in the closed position, the hole 421 is closed and the airflow between the top hole portion 435 and the bottom hole portion 427 is blocked. In the open position (see Figure 4 and Figure 5B ), the reed 423 allows airflow between the top hole portion 435 and the chamber 434 and between the chamber 434 and the channel 426. Thus, when the reed 423 is in the open position, the hole 421 is open and allows airflow between the top hole portion 435 and the bottom hole portion 427. The airflow is depicted by the dashed arrows in the figure, with some portions of the airflow labeled 450a to 450d, which will be discussed further below.

[0049] The reed 423 may be formed from the material of the movable support surface 420 itself, such as from a flexible strip of material in various embodiments, or alternatively may be a separate structure. The proximal end of the reed 423 is connected to the remainder of the valve 422, while the distal end of the reed 423 is a free end that is movable in a vertical direction relative to the remainder of the valve 422 (i.e., along the thickness dimension of the movable support surface 420). Thus, the reed 423 is configured as a cantilever such that a downward force applied to the distal end of the reed 423 causes the reed 423 to resiliently flex / bend. In the closed position (see Figure 5A ), the reed 423 is relatively unbent and generally parallel to the top and bottom sides of the third layer 430 of the movable support surface 420. In the open position (see Figure 5B ), the reed 423 is bent, wherein its distal end moves downward toward the bottom side of the movable support surface 420. The reed 423 includes a protrusion 424 at the distal end portion of the reed 423. The protrusion 424 extends vertically from the remaining portion of the reed 423, so that when the reed 435 is in the closed position, the protrusion 424 extends out of the top hole portion 435, wherein the top of the protrusion 424 is located above the top of the layer 428 (i.e., above the top of the movable support surface 420). Therefore, when there is a print medium 405 above the valve 422 (see Figure 5B ), protrusion 424 contacts the bottom surface of print medium 405. If print medium 405 is passively pressed against top surface 428 (i.e., the top surface of movable support surface 420), such as by a roller or by vacuum suction, the force applied by print medium 405 to protrusion 424 pushes protrusion 424 downward and moves reed 423 to the open position. If print medium is not present (see Figure 4), the reed 423 can return to the closed position. In some embodiments, the reed 423 is integrally formed from the material of the layer 430 (e.g., from the material of the movable support surface 420), such as by cutting or otherwise removing or omitting material to form the reed 423. In other embodiments, the reed 423 is a separate structure joined to the remainder of the valve 422.

[0050] As described above, one or more channels 426 are formed in layer 429. Figures 4 to 5B As shown, channel 426 is formed as an open space omitted or removed from layer 429. The top side of channel 426 is bounded by layer 428, and the sides are bounded by portions of layer 429. In particular, channel 426 is separated from top hole portion 435 in the lateral direction by barrier 425, which surrounds top hole portion 435 in second layer 429. Figure 4 In the embodiment, two channels 426 are provided extending along opposite sides of the top hole portion 435, and the lateral portion of the barrier 425 separates the channels 426 from the top hole portion 435. The bottom of the channel 426 is defined by the reed 423 and / or the remaining portion of the third layer 430.

[0051] When the reed 423 is in the closed position ( Figure 5A ), the top surface of the reed 423 is in contact with or very close to the layer 429 (including the barrier 425). Therefore, when the reed 423 is in the closed position, the reed 423 and the layer 429 (including the barrier 425) cooperate to separate the channel 426 from the chamber 434 to prevent airflow therebetween. Therefore, when the reed 423 is in the closed position, the airflow is blocked between the bottom hole portion 427 and the top hole portion 435, so that the vacuum suction from the vacuum air chamber is not transferred to the top hole portion 435. However, when the reed 423 is in the closed position, the vacuum suction from the vacuum air chamber is transferred to the channel 426, thereby establishing a relatively low pressure state in the channel 426. This relatively low pressure state in the channel 426 causes a vacuum suction force F1 to be applied to the reed 423, pulling the reed 423 upward. The force F1 is given by Figure 5A Therefore, in the closed state, the vacuum suction from the vacuum chamber generates a force that holds the reed 423 in the closed position.

[0052] When the reed 423 is in the open position ( Figure 4 and Figure 5B ), the top surface of the reed 423 is spaced apart from the bottom of the blocking member 425, so that air can flow between the chamber 423 and the channel 426 by passing under the blocking member 425 (via the gap between the bottom of the blocking member 425 and the top of the reed 423). Figure 4 and Figure 5BFor example, air enters hole 421 through airflow 450a via top hole portion 435, as shown in FIG. Figure 4 and Figure 5B 426, and then the air passes under the barrier 425 as shown by airflow 450b into the channel 426. The air then flows through the channel 426, as shown by airflow 450c, and enters the bottom hole portion 427, as shown by airflow 405d, from which the air exits the hole 421. Thus, when the reed 423 is in the open position, vacuum suction from below the movable support surface 420 is allowed to pass through the hole 421 via the bottom hole portion 427, the channel 426, the chamber 434, and the top hole portion 435 to the top side of the movable support surface 420. Figure 5B As shown, when there is a print medium 405 above the hole 421, the vacuum suction transmitted to the bottom side of the print medium 405 through the hole 421 generates a relatively low pressure state below the print medium 405, thereby generating a vacuum suction force F2 applied to the print medium to pull the print medium 405 downward. The force F2 is Figure 5B 423. The vacuum suction force F2 tends to pull the print medium 405 downward, causing the print medium 405 to be pressed downward against the protrusion 424 of the reed 423. The upward spring force of the reed 423 and the upward vacuum suction force F1 applied to the reed 423 tend to resist the downward movement of the reed 423, and the downward vacuum suction force F2 is large enough to overcome this resistance. Due to the geometry of the hole 421, the downward vacuum suction force F2 applied to the print medium 405 can be large enough to overcome the upward vacuum suction force F1 applied to the reed 423. For example, a larger surface area of ​​the print medium 405 can be exposed to vacuum suction, thereby generating a greater suction force. In addition, the position where the force F2 is applied to the reed 423 (i.e., at the protrusion 424) may be farther than the position where the force F1 is applied, so that the leverage (mechanical advantage) of the force F2 applied to the reed 423 is greater. Thus, the downward vacuum suction force F2 applied to the print medium 405 overcomes the resistance of the upward suction force and the spring tension of the reed 423, thereby pulling the print medium 405 against the top of the movable support surface 420, and the reed 423 is pushed downward into the open position. The reed 423 will remain in this open position as long as vacuum suction continues to be applied to the print medium 405. However, if the print medium 405 is removed, the upward vacuum suction force F1 and the spring tension of the reed 423 move the reed 423 back to the closed position.

[0053] Valve 422 can be similar to a reed valve in some aspects, which utilizes a flexible reed positioned above the hole to allow airflow through the hole in one direction while preventing airflow from passing through the hole in the opposite direction. However, valve 422 can be different from a reed valve in various ways. For example, valve 422 is not necessarily intended to allow airflow in one direction while preventing airflow in another direction, because in operation, the airflow through valve 422 has been limited to move in only one direction due to vacuum suction. In addition, in a reed valve, the reed is usually actuated due to the change of which side of the reed is exposed to a higher pressure and which side is exposed to a lower pressure (due to the change of the direction of the airflow), that is, when the lower pressure is located on the first side of the reed, the reed is opened, but when the lower pressure is located on the second side of the reed, the reed is closed. On the contrary, in valve 422, the low pressure is located on the same side of reed 423 in both the closed state and the open state (assuming that the vacuum suction is turned on). Thus, valve 422 is not actuated from closed to open due to a change in which side of reed 423 is exposed to lower pressure, but rather valve 422 is actuated from a closed state to an open state due to an external force applied to reed 423 (e.g., from the print media and / or roller).

[0054] As described above, in some embodiments, valve 422 is an integral part of movable support surface 420, being formed at least in part from the material of movable support surface 420. In some of these embodiments, movable support surface 420 comprises a flexible strip having a plurality of layers 428-432 stacked together, and valve 522 is formed within layers 428-432. The layers are formed in a Figure 5A and Figure 5BIn some embodiments, layers 428 to 432 are formed separately and then joined together, for example, by adhesive, fusion (e.g., melting), sewing, or by any other connection technology. In some embodiments, layers 428 to 432 are formed together as a whole, for example, by additive manufacturing (e.g., 3D printing). In some embodiments, some or all of the layers in layers 428 to 432 are formed by materials different from other layers in layers 428 to 432. In some embodiments, some or all of the layers in layers 428 to 432 are formed by materials identical to each other. In some embodiments, the thickness of the movable support surface 420 can be approximately 0.35 mm, and the thickness of each layer in layers 428 to 432 is less than 0.1 mm. In some embodiments, the length of the reed 423 and the chamber 434 can be approximately 0.8 mm, which can allow the movable support surface 420 to bend around the roller used in the media transmission assembly without damaging the reed 423 or causing other failures. Although layers 428 to 432 are shown and described herein as separate layers for ease of understanding, in reality, layers 428 to 432 may be indistinguishable from one another in the finished product due to being joined together or manufactured together as a whole. The above description of examples of valve 422 and layers having suitable materials and dimensions also applies to other embodiments in which valve 422 is formed as a different structure from movable support surface 420 and (or can be) joined to movable support surface 420.

[0055] Although specific shapes and relative sizes are shown for various portions of valve 422, these shapes and relative sizes are not limiting. For example, top hole portion 435 and bottom hole portion 427 can be larger or smaller, have different aspect ratios (i.e., more rectangular or less rectangular), have different shapes (e.g., square, polygonal, etc.). As another example, reed 423 can be longer, shorter, wider, narrower, or have different shapes (e.g., rectangular, etc.). In addition, although two channels 42 are shown, in other embodiments, fewer or more channels 426 can be provided to connect chamber 434 to bottom hole portion 427.

[0056] In the above about Figures 4 to 5BIn the depicted embodiment, the valve 422 is formed directly within the movable support surface 420 and is an integral part of the movable support surface 420. In other words, at least some components of the self-closing hole 421 are formed from the same body that constitutes the movable support surface 420 itself, for example, the material of the movable support surface 420 can form the barrier 425 and define the boundaries of the top hole portion 435, the bottom hole portion 427, and the channel 426. In addition, in some embodiments, the reed 423 can also be formed from the material of the movable support surface 420, as described above. However, it should be understood that the same valve 423 can be manufactured in a body that is separate from the movable support surface 420, and then the body can be later joined to the movable support surface 420. In such embodiments, a body such as the one shown in FIG. 4 is used. Figures 4 to 5B , but the material layer mentioned above as a layer of the movable support surface 420 should instead be a material layer in which the body of the valve 422 is formed. The body including the valve 422 can be inserted into the movable support surface 420 (e.g., via a hole in the movable support surface 452) and attached to the movable support surface via adhesive, fusion, press fit, friction fit, etc. In some embodiments, the body including the valve 422 is configured similar to a rivet to have a portion that changes shape after being inserted through the movable support surface 420 (e.g., via bending, deformation, expansion, etc.) to secure the body to the movable support surface 420.

[0057] The present specification and drawings illustrating inventive aspects and embodiments should not be construed as limiting - 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 present specification and claims. In some cases, well-known circuits, structures, and techniques are not shown or described in detail to avoid obscuring the present invention. The same numbers in two or more drawings represent the same or similar elements.

[0058] In addition, the terms used herein to describe aspects of the present invention, such as spatial and relational terms, are selected to help the reader understand the embodiments of the present invention, but are not intended to limit the present invention. For example, spatial terms such as "below", "under", "below", "above", "above", "inside", "outside", "upward", "downward" and the like may be used herein to describe the direction or spatial relationship of one element or feature to another element or feature, as shown in the figure. These spatial terms are used relative to the posture 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 accompanying drawings, then the item described herein as being "above" the second item with respect to the world reference system will be "below" the second item with respect to the world reference system. Therefore, different spatial terms may be used to describe the same spatial relationship or direction, depending on the reference frame being considered. In addition, the poses of the items shown in the figures are selected for ease of illustration and description, but in actual implementations, the items may have different poses.

[0059] The term "process direction" refers to the direction parallel to and pointing in the same direction as the axis along which the print media moves as it is transported through the deposition area of ​​the ink deposition assembly. Thus, the process direction is the direction parallel to the y-axis in the figure and pointing in the positive y-axis direction.

[0060] 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 "inboard" cross-process direction and an "outboard" 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 a positive or negative direction along 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 a cross-process direction" means that the valve can move in an inboard direction, an outboard direction, or both directions.

[0061] The terms "upstream" and "downstream" may refer to directions parallel to the process direction, wherein "downstream" refers to a direction pointing in the same direction as the process direction (i.e., the direction of transporting the print medium through the ink deposition assembly), and "upstream" refers to 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 positions of elements, wherein an "upstream" element is displaced in an upstream direction relative to a reference point, and a "downstream" element is displaced in a downstream direction relative to a reference point. In other words, an "upstream" element is closer to the beginning of a path taken when transporting the print medium through the ink deposition assembly (e.g., the location where the print medium engages the movable support surface) than some other reference element. Conversely, a "downstream" element is closer to the end of the path (e.g., the location where the print medium leaves the support surface) than some other reference element. The reference point of other elements to which the "upstream" or "downstream" element is compared (e.g., "the upstream side of the print head") may be explicitly stated, or may be inferred from the context.

[0062] The terms "inside" and "outside" refer to cross-process directions, where "inside" refers to one cross-process direction and "outside" refers to the cross-process direction opposite to "inside". In the figures, "inside" corresponds to the positive x-axis direction and "outside" corresponds to the negative x-axis direction. The terms "inside" and "outside" also refer to relative positions, where "inside" elements are displaced in the inside direction relative to a reference point and "outside" elements are displaced in the outside direction relative to a reference point. The reference point may be explicitly stated, or it may be inferred from the context (e.g., "inside of the print head").

[0063] The term "vertical" refers to a direction perpendicular to the movable support surface in the deposition area. At any given point, there are two perpendicular directions pointing in opposite directions, namely, an "upward" direction and a "downward" direction. Therefore, considering the reference frame 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").

[0064] The term "horizontal" refers to a direction parallel to the movable support surface in the deposition area (or tangential 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 the process direction and the cross-process direction.

[0065] The term "vacuum" has different meanings in various contexts, ranging from a space that does not contain any matter in a strict sense to a relatively low pressure state in a more general sense. In this article, the term "vacuum" is used in a general sense and should be broadly understood as a state or environment in which the air 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 the amount can be small or large. Therefore, "vacuum" as used herein may include, but is not limited to, states that may be considered a "vacuum" in the stricter sense of the term.

[0066] The term "air" has different meanings in various contexts, ranging from the Earth's atmosphere in a strict sense (or a gas mixture with a composition similar to the Earth's atmosphere) to any gas or gas mixture in a more general sense. In this document, the term "air" is used in a general sense and should be broadly understood as any gas or gas mixture. This may include, but is not limited to, the Earth's atmosphere, an inert gas such as one of the noble gases (e.g., helium, neon, argon, etc.), nitrogen (N2), or any other desired gas or gas mixture.

[0067] In addition, unless the context indicates otherwise, the singular forms "a", "an", and "the" are also intended to include the plural forms. Also, the terms "include", "comprise", "contain", etc. specify the presence of the described 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 components described may be directly connected electrically or mechanically, or they may be indirectly connected through one or more intermediate components. Unless the context of the description indicates otherwise, mathematical and geometric terms are not necessarily intended to be used according to their strict definitions, as one 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 a descriptive term, even if the term also has a strict definition.

[0068] Whenever feasible, elements and their associated aspects described in detail with reference to one embodiment may be included in other embodiments where they are not specifically shown or described. 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 claimed to be included in the second embodiment.

[0069] 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.

[0070] Other embodiments according to the present disclosure will be apparent to those skilled in the art by considering the specification and practicing the invention disclosed herein. The specification and embodiments are intended to be considered exemplary only, and the following claims are to be given their fullest scope, including equivalents, 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 a deposition area of ​​the ink deposition assembly; as well as a media transport assembly including a vacuum source and a movable support surface, the movable support surface including a valve having an aperture therethrough, and the media transport assembly being configured to hold one or more print media on the movable support surface by vacuum suction, The vacuum suction is transmitted from the vacuum source through the valve, wherein the valves are each configured to transition between a closed state in which airflow through the aperture of the corresponding valve is blocked, and an open state in which airflow through the aperture of the corresponding valve is permitted, wherein the valves are configured such that, for each of the valves: In the absence of the printing medium covering the corresponding valve, the corresponding valve is maintained in the closed state; and In the case where one of the printing media covers the corresponding valve, The corresponding valve is maintained in the open state by a force applied by the print medium to the corresponding valve through contact between the print medium and the corresponding valve, wherein the force applied by the print medium to the corresponding valve is generated by a weight of the print medium and a suction force applied by vacuum suction from the vacuum source to the print medium.

2. The printing system according to claim 1, wherein the valve is biased into the closed state.

3. The printing system according to claim 2, wherein each of the valves is biased toward the closed state by a biasing force, the biasing force comprising a combination of an internal spring force and a suction force applied to the respective valve from the vacuum suction, wherein both the spring force and the suction force urge the valve toward the closed state; and Each of the valves is configured such that, under a condition that one of the printing media covers the corresponding valve, the force applied to the corresponding valve by the printing medium overcomes the biasing force.

4. The printing system according to claim 3, Each of the valves is configured such that, in the absence of print medium covering the corresponding valve, the biasing force causes the valve to move to and / or remain in the closed state.

5. The printing system according to claim 1, Each of the valves includes a flexible reed configured as a cantilever coupled to the movable support surface, and the flexible reed is movable by bending between an open position and a closed position, wherein the open position allows airflow through the hole of the corresponding valve, and the closed position blocks airflow through the hole of the corresponding valve, the open position of the flexible reed corresponds to the open state of the corresponding valve and the closed position of the flexible reed corresponds to the closed state of the corresponding valve.

6. The printing system according to claim 5, wherein each of the valves is biased toward the closed state by an internal spring force generated by a flexible reed of the respective valve and a suction force from the vacuum suction applied to the flexible reed of the respective valve, wherein both the spring force and the suction force urge the flexible reed of the respective valve toward the closed position; Each of the valves is configured such that the vacuum suction from the vacuum source is directed through the aperture of the corresponding valve to generate the suction force on the flexible reed.

7. The printing system according to claim 6, Each of the valves is configured such that, under the condition that the corresponding valve is in the open state and no printing medium covers the corresponding valve, the biasing force moves the flexible reed to the closed position to transform the corresponding valve into the closed state.

8. The printing system according to claim 6, Each of the valves is configured such that, under the condition that the corresponding valve is in the open state and is covered by one of the printing media, the force applied by the printing medium to the corresponding valve is sufficient to overcome the biasing force and hold the flexible reed in the open position.

9. The printing system according to claim 1, Wherein the media transport assembly further comprises a roller arranged to engage the valves as the valves move past the roller, wherein engagement of the roller with one of the valves transitions the valve to the open state.

10. The printing system according to claim 1, wherein the media transfer 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.

11. The printing system according to claim 1, wherein the media transport assembly further comprises a roller arranged to transition each of the valves to an open state by engaging each of the valves as the valves move past the roller, Each of the valves, after being in the open state, is configured as follows: Under the condition that the corresponding valve is covered by one of the printing media, the corresponding valve is maintained in the open state due to the force applied to the corresponding valve by the printing medium; Under the condition that the corresponding valve is not covered by the printing medium, the corresponding valve is converted into the closed state due to the biasing force applied to the corresponding valve.

12. The printing system according to claim 1, wherein For each of the valves, the corresponding valve is configured to be passively actuated from the closed state to the open state by the print medium contacting and applying force to the movable part of the corresponding valve in a state where the corresponding valve is covered by one of the print media.

13. A movable support surface for a printing system, the movable support surface comprising: Flexible belt; as well as a plurality of valves disposed in the flexible belt to transmit vacuum suction through the flexible belt to hold print media transported by the movable support surface on the flexible belt, wherein the valve is configured to transition between an open state in which the vacuum suction is transmitted through the corresponding valve and a closed state in which the vacuum suction is blocked by the corresponding valve, and Each of the valves includes a hole and a flexible reed configured as a cantilever coupled to the flexible strip, and the flexible reed is movable by bending between an open position and a closed position, wherein the open position allows airflow through the hole of the corresponding valve, and the closed position blocks airflow through the hole of the corresponding valve, the open position of the flexible reed corresponds to the open state of the corresponding valve and the closed position of the flexible reed corresponds to the closed state of the corresponding valve.

14. The movable support surface according to claim 13, Each of the valves is configured to bias the flexible reed to the closed position at least in part by a spring force generated by the flexible reed.

15. The movable support surface according to claim 13, The flexible reed includes a protrusion configured to extend above a top surface of the movable support surface when the flexible reed is in the closed position.

16. The movable support surface of claim 15, wherein For each of the valves, the flexible reed of the corresponding valve is configured to be passively actuated from the closed state to the open state by the printing medium contacting and applying force to the protrusion of the flexible reed of the corresponding valve when the corresponding valve is covered by one of the printing media.

17. The movable support surface according to claim 13, Each of the valves is configured such that, under a condition where vacuum suction is provided to an area below the valve, the vacuum suction generates a biasing force on the flexible reed that pushes the flexible reed toward the closed position.

18. A method comprising: loading print media onto a movable support surface of a media transport assembly of the printing system; holding the print medium on the movable support surface via vacuum suction from a vacuum source delivered through a valve in the movable support surface; causing those of the valves covered by the print medium to transition from a closed state in which vacuum suction through the corresponding valve is blocked to an open state in which vacuum suction through the corresponding valve is allowed via an opening force applied to the valve by the print medium; causing those of the valves that are covered by the print medium and have been turned to the open state to be maintained in the open state via a holding force applied to the valves by the print medium, the holding force being generated by the weight of the print medium and a suction force applied to the print medium by the vacuum suction from the vacuum source; conveying the print media via the movable support surface in a process direction through a deposition area of ​​a print head of the printing system; as well as Printing fluid is ejected from the print head to deposit the printing fluid onto the print medium in the deposition area.

19. The method according to claim 18, wherein Causing those of the valves covered by the print medium to transition from the closed state to the open state includes the opening force being generated by pressing the print medium against the valve via a roller.

20. The method according to claim 19, further comprising: Through the interaction between the roller and the valve, those valves among the valves that are not covered by the printing medium are transformed from the closed state to the open state, and those valves among the valves that are not covered by the printing medium are transformed from the open state to the closed state by the biasing force after the interaction with the roller.

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