Patent Publication Number: US-11642899-B2

Title: Recording device

Description:
The present application is based on, and claims priority from JP Application Serial Number 2020-138620, filed Aug. 19, 2020, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a recording device. 
     2. Related Art 
     An inkjet recording device disclosed in JP-A-2005-161758 is provided with an air blowing mechanism including a discharge fan that discharges air in a direction in which the air is blown with respect to an ink discharge unit of a recording head, and an air recovery mechanism including a recovery fan that sucks the air in a direction in which the air is received with respect to the ink discharge unit of the recording head. 
     The inkjet recording device disclosed in JP-A-2005-161758 is installed in an installation location including exhaust equipment, and the air recovery mechanism may be connected to the exhaust equipment via a duct. An exhaust capacity of the exhaust equipment is already determined at the installation location of the inkjet recording device, and the inkjet recording device cannot control the exhaust capacity of the exhaust equipment. 
     Here, when the exhaust capacity of the exhaust equipment is greater than an exhaust capacity of the recovery fan, there is a risk that an air flow inside the device created by the recovery fan may be disturbed by the discharge of air by the exhaust equipment. 
     SUMMARY 
     In order to solve the above-described problem, a recording device according to the present disclosure includes a recording unit configured to perform recording on a medium transported in a transport direction, a support unit facing the recording unit and including a support face configured to support the medium, a feeding unit provided upstream of the recording unit in the transport direction and configured to feed gas toward the support face, a suction unit provided downstream of the recording unit in the transport direction and configured to suck gas flowing from the support face, and a duct unit through which gas discharged from the suction unit flows. A pressure difference adjustment unit is provided in the duct unit, the pressure difference adjustment unit being configured to adjust a pressure difference between a pressure inside the duct unit and a pressure outside the duct unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a front view of a printer according to a first embodiment. 
         FIG.  2    is a schematic diagram illustrating an internal structure of the printer according to the first embodiment. 
         FIG.  3    is a plan view illustrating a bottom surface of a first duct according to the first embodiment. 
         FIG.  4    is a perspective view illustrating the first duct and a second duct according to the first embodiment. 
         FIG.  5    is a perspective view illustrating a section from the first duct according to the first embodiment to an exhaust duct of a factory. 
         FIG.  6    is a plan view illustrating a relationship between arrangements of the first duct and the second duct according to the first embodiment. 
         FIG.  7    is a schematic diagram illustrating a state in which a gas flows in the printer according to the first embodiment. 
         FIG.  8    is a schematic diagram illustrating a state in which a gas flows in a printer according to a second embodiment. 
         FIG.  9    is a perspective view illustrating a section from the first duct according to the second embodiment to the exhaust duct of the factory. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, the present disclosure will be described in overview. 
     A recording device according to a first aspect of the present disclosure for solving the above-described problem includes a recording unit configured to perform recording on a medium transported in a transport direction, a support unit facing the recording unit and including a support face configured to support the medium, a feeding unit provided upstream of the recording unit in the transport direction and configured to feed gas toward the support face, a suction unit provided downstream of the recording unit in the transport direction and configured to suck gas flowing from the support face, and a duct unit through which gas discharged from the suction unit flows. A pressure difference adjustment unit is provided in the duct unit, the pressure difference adjustment unit being configured to adjust a pressure difference between a pressure inside the duct unit and a pressure outside the duct unit. 
     An end of the duct unit through which gas discharged from the suction unit flows is coupled to exhaust equipment of a factory in which the recording device is installed, for example. 
     According to the present aspect, for example, when an exhaust capacity of the exhaust equipment is greater than an exhaust capacity of the suction unit provided in the recording device, the pressure inside the duct unit is lower than the pressure outside the duct unit. 
     Here, since the pressure difference between the pressure inside the duct unit and the pressure outside the duct unit is adjusted using the pressure difference adjustment unit, it is possible to reduce the pressure difference. Thus, even when the exhaust capacity of the exhaust equipment is greater than the exhaust capacity of the suction unit provided in the recording device, it is possible to suppress an air flow in the periphery of the recording unit and an air flow inside the suction unit from being disturbed by the discharge of air by the exhaust equipment. 
     With respect to the first aspect, the recording device according to a second aspect is a hole portion provided at a side portion of the duct unit. 
     According to the present aspect, since it is sufficient only that the hole portion be provided at the side portion of the duct unit, the pressure difference adjustment unit can be realized using a simple configuration, compared to a configuration in which a unit that adjusts the pressure difference is attached to the duct unit. 
     With respect to the second aspect, in the recording device according to a third aspect, the pressure difference adjustment unit includes a pipe coupled to the hole portion, the pipe being communicable with the inside of the duct unit and the outside of the duct unit, and a valve provided at the pipe, the valve being configured to adjust a flow rate of gas flowing inside the pipe. 
     According to the present aspect, by adjusting the flow rate of the gas flowing inside the pipe in accordance with a degree of opening of the valve, it is possible to reduce the pressure difference between the pressure inside the duct and the pressure outside the duct. In this way, the pressure difference can be changed in accordance with the capacity of the exhaust equipment at an installation location of the recording device. 
     With respect to the second aspect or the third aspect, in a recording device according to a fourth aspect, the duct unit includes a first duct into which gas flows from the suction unit, and a second duct positioned upstream of the first duct in a gravitational direction, and coupled to the first duct. As seen from the gravitational direction, an inner wall surface of the second duct is positioned further to the outside than an outer wall surface of the first duct. As seen from the gravitational direction, the hole portion is a gap between the inner wall surface and the outer wall surface. According to the present aspect, the gap between the inner wall surface and the outer wall surface functions as the hole portion. Here, since the second duct covers the first duct from upstream in the gravitational direction, even if dust falls in the gravitational direction from a ceiling of the installation location of the recording device, the dust can be prevented from entering the first duct and the second duct through the hole portion. 
     With respect to the fourth aspect, in a recording device according to a fifth aspect, an upper wall, to which the second duct is attached, is provided at an upstream end portion, in the gravitational direction, of the first duct. A ventilation hole is formed at the upper wall, the ventilation hole extending through the upper wall in the gravitational direction, and gas being flowable through the ventilation hole. A peripheral edge portion of the ventilation hole at the upper wall is inclined with respect to a horizontal direction orthogonal to the gravitational direction. 
     According to the present aspect, compared to a configuration in which the peripheral edge portion of the ventilation hole at the upper wall is along the horizontal direction, the gas can easily flow in the direction in which the upper wall is inclined. Thus, the gas can be suppressed from stagnating in a part of the suction unit. 
     With respect to the fourth aspect or the fifth aspect, a recording device according to a sixth aspect includes a third duct positioned upstream, in the gravitational direction, of the second duct and coupled to the second duct. A filter is detachably provided at the third duct, gas inside the third duct being permeable through the filter. 
     Foreign material may be included in the gas discharged from the suction unit. 
     According to the present aspect, the foreign material in the gas can be recovered by the filter, and the filter that is contaminated by the foreign material can be easily replaced. 
     With respect to any one of the first aspect to the sixth aspect, in a recording device according to a seventh aspect, the suction unit includes a circulation portion extending from a position between the recording unit and the support face to the duct unit, gas being flowable through the inside of the circulation portion, and a suction fan provided inside the duct unit and configured to suck gas. The duct unit includes a partition wall extending to the interior of the circulation portion and configured to partition a part of the circulation portion between the recording unit and the suction fan. 
     According to the present aspect, a part of the circulation portion is partitioned, between the recording unit and the suction fan, by the partition wall. Here, when a part of the gas that has not been sucked into the suction fan stagnates and flows toward the recording unit, the partition wall restricts the flow of this part of the gas. In this way, the gas that has flowed downstream from a space between the recording unit and the support face can be suppressed from once more flowing into the space and contaminating the medium. 
     With respect to the seventh aspect, in the recording device according to an eighth aspect, a part of the partition wall is inclined with respect to the horizontal direction orthogonal to the gravitational direction. 
     According to the present aspect, compared to a configuration in which a part of the partition wall is along the horizontal direction, the gas can easily flow in a direction in which the part of the partition wall is inclined. Thus, the gas can be suppressed from stagnating in a part of the suction unit. 
     First Embodiment 
     Hereinafter, a printer  10  according to a first embodiment, which is an example of a recording device according to the present disclosure, will be specifically described. 
       FIG.  1    illustrates an overall configuration of the printer  10  installed on a floor  2  of a factory  1 , which is an example of a installation location. The printer  10  performs recording on a medium M. Examples of the medium M include fabric and a sheet. Note that an X-Y-Z coordinate system illustrated in each of the drawings is an orthogonal coordinate system. 
     An X direction is a device width direction of the printer  10 , and, as an example, is a horizontal direction orthogonal to a gravitational direction to be described below. When the printer  10  is viewed from the front, a direction toward the left in the X direction is a positive X direction, and a direction toward the right is a negative X direction. Further, the X direction is an example of a width direction of the medium M. 
     A Y direction is an example of a transport direction of the medium M and of a depth direction of the printer  10 , and is a horizontal direction. Here, the transport direction in which the medium M is transported is a positive Y direction, and the direction opposite to the positive Y direction is a negative Y direction. 
     A Z direction is an example of a device height direction of the printer  10 . Here, the gravitational direction in which gravity acts on the printer  10  is a positive Z direction. Also note that a negative Z direction is the direction opposite to the gravitational direction. 
     An exhaust device  4 , which is an example of exhaust equipment, is installed on the floor  2 . Note that the exhaust device  4  may be provided at a ceiling portion (not illustrated) of the factory  1 . 
     The exhaust device  4  is provided with an exhaust fan (not illustrated), and is coupled to a third duct  92 , to be described below, of the printer  10 , via an exhaust duct  6 . Air discharge from the printer  10  is recovered by the exhaust device  4 , is cleaned, and then discharged from the exhaust device  4  to the outside of the factory  1 . Here, an amount of air generated as a result of the exhaust fan of the exhaust device  4  being rotated, that is, a flow rate of the air, is assumed to be V1 (m 3 /sec). The air is an example of a gas. 
     In this way, in the printer  10 , an end of a duct unit  54 , to be described later, is coupled to the exhaust device  4  via the exhaust duct  6 . 
     As illustrated in  FIG.  2   , the printer  10  includes, for example, a main body frame  12 , a main body cover  14 , a transport unit  16 , a recording unit  20 , a cleaning unit  26 , a control unit  28 , and a flow path  30 . 
     Specifically, as main units, the printer  10  is provided with the recording unit  20 , a glue belt  17 , a feeding unit  32 , a suction unit  42 , a duct unit  54 , and opening portions  86 , to be described later. 
     The main body frame  12  is configured as a base unit on which each of the units of the printer  10  are provided. 
     The main body cover  14  is an outer member that covers each of the units of the printer  10 . In the main body cover  14 , a section further in the positive Y direction than a center thereof in the Y direction protrudes in the negative Z direction. Of sections configuring the main body cover  14 , a wall portion in the negative Y direction is referred to as a side wall  14 A, and a wall portion in the negative Z direction is referred to as an upper wall portion  14 B. A plurality of inflow ports  15  are formed in the side wall  14 A that allow air to flow from the outside of the side wall  14 A to the interior of the main body cover  14 . 
     The transport unit  16  includes a driving roller  16 A, a driven roller  16 B, the glue belt  17 , and a winding roller (not illustrated). Then, the transport unit  16  can transport the medium M in the positive Y direction, in accordance with the movement of the glue belt  17  caused by the rotation of the driving roller  16 A. In the positive Y direction, the driving roller  16 A is disposed downstream and the driven roller  16 B is disposed upstream. Further, both the driving roller  16 A and the driven roller  16 B have a rotation axis along the X direction. The rotation of the driving roller  16 A is controlled by the control unit  28  to be described below. 
     The glue belt  17  is an example of a support unit, and is configured as an endless belt formed by bonding together both ends of an elastic flat plate. Further, the glue belt  17  is wound over the outer circumferential surface of the driving roller  16 A and the outer circumferential surface of the driven roller  16 B, and can move in a revolving manner. 
     For example, an outer circumferential surface  17 A of the glue belt  17  has tackiness and is able to support and suck the medium M. The tackiness refers to a property of being able to temporarily adhere to another member, and being able to be peeled from an adhering state. 
     A flat portion of the outer circumferential surface  17 A positioned between the driving roller  16 A and the driven roller  16 B in the negative Z direction is a support face  18 . In other words, the glue belt  17  includes the support face  18 . A portion of the support face  18  faces the recording unit  20 , to be described later, in the Z direction. Further, the support face  18  can support the medium M. In other words, the printer  10  according to the embodiment is an inkjet type printer. 
     The recording unit  20  is an example of a recording unit, and can perform recording on the medium M transported in the positive Y direction. Specifically, the recording unit  20  includes a recording head  21 , which is an example of a discharge unit, and a carriage  22  that supports the recording head  21  such that the recording head  21  can reciprocate in the X direction. Further, the recording unit  20  is disposed above (in the negative Z direction) with respect to the glue belt  17 . 
     The recording head  21  includes a plurality of nozzles (not illustrated) and is disposed in the negative Z direction with respect to the support face  18 . Air can flow through a space  41  between the recording head  21  and the support face  18  or the medium M. In other words, the space  41  configures a part of a flow path through which air flows. 
     Further, the recording head  21  can perform the recording on the medium M by discharging ink, which is an example of droplets, from the plurality of nozzles onto a recording surface MA of the medium M. 
     The cleaning unit  26  is positioned downstream of the driving roller  16 A in a direction in which the glue belt  17  revolves, and cleans the outer circumferential surface  17 A. 
     The control unit  28  includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and storage (all not illustrated), and controls operations of each of the units of the printer  10 . 
     Of a space inside the printer  10 , the flow path  30  is a section that includes the space  41  described above and functions as a flow path through which air is forcibly caused to flow. Further, for example, the flow path  30  includes the feeding unit  32 , the suction unit  42 , the duct unit  54 , and the opening portions  86 . 
     The feeding unit  32  is provided upstream of the recording unit  20  in the positive Y direction, and feeds air toward the support face  18 . Specifically, for example, the feeding unit  32  includes a first flow path forming portion  33 , a second flow path forming portion  34 , a third flow path forming portion  35 , and a fourth flow path forming portion  36 . Each of the first flow path forming section  33 , the second flow path forming section  34 , the third flow path forming section  35 , and the fourth flow path forming section  36  is formed in a cylindrical shape by members (not illustrated), each configuring the interior of the printer  10 , and by the main body cover  14 . 
     The first flow path forming portion  33  communicates with the outside of the printer  10  via an inlet  15 , and extends from the inlet  15  in the negative Z direction. 
     The second flow path forming portion  34  extends in the positive Y direction from an end portion, in the negative Z direction, of the first flow path forming portion  33 . Further, a first fan  38  is provided inside the second flow path forming portion  34 . 
     The first fan  38  is rotated by a motor (not illustrated) to take in air from the first flow path forming portion  33  toward the second flow path forming portion  34 , and discharge the air from the second flow path forming portion  34  toward the third flow path forming portion  35 . 
     The third flow path forming portion  35  is bent in an L shape as viewed in the X direction, and includes a section extending from the second flow path forming portion  34  in the positive Y direction, and a section extending in the positive Z direction from an end portion thereof in the positive Y direction. Note that, for example, a flow path cross-sectional area of the third flow path forming portion  35  is smaller than a flow path cross-sectional area of the second flow path forming portion  34 . The flow path cross-sectional area is an area of the flow path in a plane orthogonal to a direction in which air flows. Further, an outlet  39  through which the air is blown in the positive Z direction toward the fourth flow path forming portion  36  is formed at section forming a terminal end of the third flow path forming portion  35 . 
     The fourth flow path forming portion  36  extends from the outlet  39  in the positive Z direction. Further, the dimension in the X direction of the fourth flow path forming portion  36  is substantially the same size as the dimension in the X direction of the glue belt  17 . In other words, the fourth flow path forming portion  36  is long in the X direction. An end portion in the positive Z direction of the fourth flow path forming portion  36  is connected to the space  41 . 
     In this way, the feeding unit  32  is capable of feeding the air flowing in from the inlet  15  into the space  41 . 
     Note that, in principle, the space  41  refers to a space between the recording head  21  and the support face  18 . Here, the recording head  21  reciprocates along the X direction. Thus, the space  41  also includes a space between a movement region in the X direction of the recording head  21  and the support face  18 . 
     The suction unit  42  is provided downstream of the recording unit  20  in the positive Y direction, and sucks air flowing from the support face  18 . Specifically, the suction unit  42  includes a circulation portion  44  and a second fan  52 . 
     The circulation portion  44  extends from the space  41  to the first duct  56  to be described later, and the air can circulate inside the circulation portion  44 . Further, for example, the circulation portion  44  includes a fifth flow path forming portion  46  and a sixth flow path forming portion  48 . The fifth flow path forming portion  46  and the sixth flow path forming portion  48  are formed in a cylindrical shape by members (not illustrated), each configuring the interior of the printer  10 , and by the main body cover  14 . 
     The fifth flow path forming portion  46  extends in the negative Z direction from a section in the positive Y direction with respect to the space  41 . Further, the dimension in the X direction of the fifth flow path forming portion  46  is substantially the same size as the dimension in the X direction of the glue belt  17 . An end portion of the fifth flow path forming portion  46  in the positive Z direction is connected to the space  41 . In other words, the air flowing through the interior of the space  41  is fed into the fifth flow path forming portion  46 . 
     The sixth flow path forming portion  48  extends in the negative Z direction from an end portion in the negative Z direction of the fifth flow path forming portion  46 . Further, the dimension in the X direction of the sixth flow path forming portion  48  is substantially the same size as the dimension in the X direction of the glue belt  17 . For example, the flow path cross-sectional area of the sixth flow path forming portion  48  is greater than the flow path cross-sectional area of the fifth flow path forming portion  46 . An end portion of the sixth flow path forming portion  48  in the negative Z direction is connected to the first duct  56  to be described later. 
     The second fan  52  is an example of a suction fan, and is provided inside the first duct  56  to be described later. Further, the second fan  52  sucks air from the fifth flow path forming portion  46  and the sixth flow path forming portion  48 . Then, the air sucked by the second fan  52  is discharged into the interior of the first duct  56 . 
     In this way, the suction unit  42  sucks the air flowing from the space  41 , and discharges the air to the first duct  56 . 
     The duct unit  54  includes, for example, the first duct  56 , a second duct  76 , and the third duct  92 . The air discharged from the suction unit  42  flows inside the duct unit  54 . Note that the air flowing inside the suction unit  42  and the duct unit  54  is very likely to include ink mist, which is a part of the ink discharged from the recording head  21 , dust inside the printer  10 , and the like. 
     The first duct  56  is fixed to the upper wall portion  14 B using bolts (not illustrated). The air from the suction unit  42  flows into the first duct  56 . Specifically, the first duct  56  is formed in a hollow box shape including a bottom wall  57 , side walls  62 , and an upper wall  72 . 
     The bottom wall  57  slopes obliquely downward as viewed from the X direction. In other words, the bottom wall  57  is inclined relative to the Y direction as viewed from the X direction. An end portion of the bottom wall  57  in the negative Y direction is positioned further in the positive Z direction than an end portion of the base wall  57  in the positive Y direction. Further, the bottom wall  57  extends in the X direction, and the dimension in the X direction thereof is substantially the same size as the dimension in the X direction of the glue belt  17 . 
     As illustrated in  FIG.  3   , eight through holes  58  are formed in the bottom wall  57 , for example. The eight through holes  58  are disposed while being spaced apart in the X direction, and penetrate the bottom wall  57  in the Z direction. Each of the through holes  58  is formed in a square shape having a set of sides along the X direction and a set of sides along the Y direction, as viewed from the Z direction. The center (not illustrated) of each of the through holes  58  is positioned in the negative Y direction with respect to the center in the Y direction of the bottom wall  57 . In other words, for example, each of the through holes  58  is disposed to be biased toward the end portion in the negative Y direction of the bottom wall  57 . 
     The side walls  62  are provided in the negative Z direction from both ends in the X direction and both end portions in the Y direction of the bottom wall  57 , except for a portion of a third side wall  65  to be described below. Specifically, the side walls  62  include a pair of first side walls  63  facing each other in the X direction, a second side wall  64  connecting, in the X direction, end portions in the positive Y direction of the pair of first side walls  63 , and a third side wall  65  connecting, in the X direction, end portions in the negative Y direction of the pair of first side walls  63 . 
     Of an end face, in the negative Z direction, of the first side wall  63 , an end thereof in the negative Y direction is positioned further in the positive Z direction than an end thereof in the positive Y direction, namely, the end face is inclined obliquely downward. In other words, the end face in the negative Z direction of the first side wall  63  is inclined with respect to the Y direction as viewed from the X direction. An end face of the third side wall  65  in the positive Z direction is positioned further in the positive Z direction than an end face of the second side wall  64  in the positive Z direction. An end face of the third side wall  65  in the negative Z direction is positioned further in the positive Z direction than an end face in the negative Z direction of the second side wall  64 . 
     As illustrated in  FIG.  7   , the end portion of the bottom wall  57  in the positive Y direction connects to a part of the top wall  14 B. The second side wall  64  stands upright in the negative Z direction from a part of the top wall  14 B. 
     The third side wall  65  is an example of a partition wall The third side wall  65  extends into the interior of, and partitions a part of, the circulation portion  44 , between the recording unit  20  and the second fan  52 . Specifically, the third side wall  65  includes an upper portion  66  that stands upright in the negative Z direction from the end portion in the negative Y direction of the bottom wall  57 , and a lower portion  67  that extends in the positive Z direction from the end portion in the negative Y direction of the bottom wall  57 . A part of the upper portion  66  is connected to the top wall  14 B. 
     A side surface in the positive Y direction of the second side wall  64  is referred to as an outer wall surface  64 A. A side surface in the negative Y direction of the third side wall  65  is referred to as an outer wall surface  65 A. 
     Note that in  FIG.  7   , the main flow of the air from the interior of the printer  10  toward the exhaust duct  6  is indicated by a dashed line arrow A1, and the flow of the air flowing into the duct unit  54  via the opening portion  86  is indicated by a dashed line arrow A2. 
     The lower portion  67  includes a vertical wall  68  along the X-Z plane and an inclined wall  69  extending obliquely upward from an end portion in the positive Z direction of the vertical wall  68 . The vertical wall  68  and the inclined wall  69  are positioned inside the sixth flow path forming portion  48 . 
     The inclined wall  69  is inclined in an intersecting direction intersecting the Y direction as viewed from the X direction. An end portion in the positive Y direction of the inclined wall  69  is positioned further in the negative Z direction than an end portion in the positive Y direction thereof. That is, a part of the first side wall  63  is inclined with respect to the Y direction that is orthogonal to the positive Z direction. Further, the inclined wall  69  extends to a position where the end portion in the positive Y direction thereof covers the through hole  58  as viewed from the positive Z direction. In this way, the inclined wall  69  partitions a part of a space of the sixth flow path forming portion  48  into a space close to the recording unit  20  and a space close to the first duct  56 . 
     The upper wall  72  is provided at a downstream end portion of the first duct  56  in the negative Z direction. Further, the upper wall  72  also covers the bottom wall  57  and the side wall  62  from the negative Z direction, except for a part of the bottom wall  57 . Furthermore, the upper wall  72  is inclined obliquely downward as viewed from the X direction, and an end portion in the negative Y direction thereof is positioned further in the positive Z direction than an end portion in the positive Y direction thereof. Further, the upper wall  72  extends in the X direction, and the dimension in the X direction thereof is substantially the same size as the dimension in the X direction of the glue belt  17 . The second duct  76 , to be described later, is attached to the upper wall  72 . 
     The first duct  56  and the second duct  76  are illustrated in  FIG.  4   . One ventilation hole  73 , which penetrates the upper wall  72  in the positive Z direction, is formed in a central portion in the X direction of the upper wall  72 , for example. The ventilation hole  73  is formed in a square shape having a pair of sides along the X direction and a pair of sides along the Y direction. The center of the ventilation hole  73  in the Y direction is positioned in the center, in the Y direction, in the upper wall  72 . An opening area of the ventilation hole  73  is larger than an opening area of one of the through holes  58  ( FIG.  3   ). In this way, the ventilation hole  73  is formed in the upper wall  72  so that the air can flow therethrough. A peripheral edge portion  72 A of the ventilation hole  73  in the upper wall  72  is inclined in a direction intersecting the Y direction as viewed from the X direction. In other words, the peripheral edge portion  72 A of the ventilation hole  73  in the upper wall  72  is inclined with respect to the Y direction that is orthogonal to the positive Z direction. 
     The second duct  76  is positioned downstream of the first duct  56  in the negative Z direction. In other words, the second duct  76  is positioned upstream of the first duct  56  in the positive Z direction. Further, the second duct  76  is coupled to the first duct  56 . Specifically, the second duct  76  includes a pair of opposing walls  77  facing each other in the X direction, a first vertical wall  78  and a second vertical wall  79  facing each other in the Y direction, and a top wall  82  and inclined walls  83  and  84  that form a ceiling portion of the second duct  76 . 
     End faces of the opposing walls  77  in the positive Z direction are inclined along the upper wall  72 . Both end portions in the Y direction of the opposing walls  77  stand upright in the negative Z direction. End faces in the negative Z direction of the opposing walls  77  extend along the Y direction. Plate portions  81  that protrude toward the outside in the X direction are formed on end portions, in the positive Z direction, of the opposing walls  77 . The plate portions  81  are attached to the upper wall  72  by bolts  89 . Further, the dimension of the opposing wall  77  in the Y direction is greater than the dimension of the first duct  56  in the Y direction. 
     As illustrated in  FIG.  7   , the first vertical wall  78  connects, in the X direction, end portions of the pair of opposing walls  77  ( FIG.  4   ) in the positive Y direction. A side surface in the negative Y direction of the first vertical wall  78  is an inner wall surface  78 A. Further, the first vertical wall  78  and the second side wall  64  are collectively referred to as a side portion  61 A. 
     The second vertical wall  79  connects, in the X direction, end portions in the negative Y direction of the pair of opposing walls  77 . A side surface in the positive Y direction of the second vertical wall  79  is an inner wall surface  79 A. Further, the second vertical wall  79  and the third side wall  65  are collectively referred to as a side portion  61 B. 
     As illustrated in  FIG.  4   , the top wall  82  connects, in the Y direction, the center in the X direction of the first vertical wall  78  and the center in the X direction of the second vertical wall  79 . Further, the top wall  82  is formed in a plate shape having a predetermined thickness in the Z direction. One ventilation hole  85 , which penetrates the top wall  82  in the positive Z direction, is formed in the top wall  82 . 
     The ventilation hole  85  is formed in a square shape having a pair of sides along the X direction and a pair of sides along the Y direction. The center of the ventilation hole  85  in the Y direction is positioned in the center, in the Y direction, in the top wall  82 . The ventilation hole  85  is aligned in the Z direction with the ventilation hole  73 . An opening area of the ventilation hole  85  is larger than the opening area of the ventilation hole  73 . In this way, the ventilation hole  85  is formed in the top wall  82  so that the air can flow therethrough. 
     The inclined wall  83  is inclined from an end portion in the positive X direction of the top wall  82  toward the end portion in the negative Z direction of the opposing wall  77  in the positive X direction. The inclined wall  84  is inclined from an end portion in the negative X direction of the top wall  82  toward the end portion in the negative Z direction of the opposing wall  77  in the negative X direction. 
     As illustrated in  FIG.  5    and  FIG.  7   , the third duct  92  is positioned upstream of the second duct  76  in the positive Z direction and is coupled to the second duct  76 . Specifically, the third duct  92  includes a pair of vertical walls  93  facing each other in the X direction, a vertical wall  94  and a vertical wall  95  facing each other in the Y direction, and a top wall  96  configuring an end portion of the third duct  92  in the negative Z direction. Note that the vertical wall  93  in the positive X direction is not illustrated. 
     The vertical wall  94  is disposed downstream of the vertical wall  95  in the positive Y direction. Further, the vertical wall  94  is attached to the pair of vertical walls  93  using screws (not illustrated). Note that the vertical wall  94  can be removed from the pair of vertical walls  93  by removing the screws. In other words, the vertical wall  94  is detachably provided on the pair of vertical walls  93 . 
     The top wall  96  covers, from the negative Z direction, a space enclosed by the pair of vertical walls  93 , the vertical wall  94 , and the vertical wall  95 . One ventilation hole  97 , which penetrates the top wall  96  in the positive Z direction, is formed in the top wall  96 . The ventilation hole  97  is formed in a circular shape as viewed from the Z direction. The center of the ventilation hole  97  is positioned in the center in the top wall  96 . An opening area of the ventilation hole  97  is smaller than an opening area of the exhaust duct  6 . In this way, the ventilation hole  97  is formed in the top wall  96  so that the air can flow therethrough. 
     As illustrated in  FIG.  7   , a filter  98  is provided inside the third duct  92 . The filter  98  is mounted in the third duct  92  by attaching the vertical wall  94  to the pair of vertical walls  93  ( FIG.  5   ) in a state of being disposed inside the third duct  92 . Further, the filter  98  can be detached from the third duct  92  by removing the vertical wall  94  from the pair of vertical walls  93 . In this way, the filter  98  is detachably provided in the third duct  92 . 
     The filter  98  is configured to allow the air inside the third duct  92  to pass therethrough. Further, the filter  98  is able to capture foreign material, such as ink mist or the like mixed in with the air. A non-woven fabric, glass wool, and rock wool can be used as the filter  98 . 
     As viewed from the positive Z direction, the inner wall surface  78 A is positioned further to the outer side in the positive Y direction than the outer wall surface  64 A. Similarly, the inner wall surface  79 A is positioned further to the outer side in the negative Y direction than the outer wall surface  65 A. 
     As viewed from the positive Z direction, a section corresponding to a gap between the inner wall surface  78 A and the outer wall surface  64 A, and a section corresponding to a gap between the inner wall surface  79 A and the outer wall surface  65 A are, respectively, the opening portions  86 . The opening portion  86  is an example of a hole portion. Further, the opening portion  86  is also an example of a pressure difference adjustment portion provided on the side portions  61 A and  61 B of the duct unit  54 . 
     The opening portion  86  adjusts a pressure difference ΔP (=P2−P1) between a pressure P1 inside the duct unit  54  and a pressure P2 inside the exhaust duct  6 . In other words, the pressure P2 is the pressure P2 outside the duct unit  54 . Note that the pressure difference ΔP is not illustrated. The flow path cross-sectional area of the opening portion  86  is determined by performing a fluid simulation in advance, so as to reduce the pressure difference ΔP. 
     In the duct unit  54 , the amount of air generated by the second fan  52  being rotated, that is, the flow rate of the air, is V2 (m 3 /sec). With respect to the flow rate V1 of the air in the exhaust device  4  ( FIG.  1   ) described above, the flow rate V2 is set such that V2 is smaller than V1. As a result of the flow rate V1 being generated, the pressure inside the exhaust duct  6  becomes the pressure P1. On the other hand, as a result of the flow rate V2 being generated, the pressure inside the duct unit  54  becomes the pressure P2. 
     Here, the pressure P1 is less than the pressure P2, that is, the pressure difference ΔP is generated, and thus, in particular, a part of the air flowing through the circulation portion  44  may be discharged to the duct portion  54  regardless of the rotational state of the second fan  52 . In this case, if the pressure difference ΔP is not adjusted, the flow of the air may be disturbed in each of the flow paths including the circulation portion  44  inside the printer  10 . 
     In the embodiment, the “adjustment of the pressure difference ΔP” performed by the pressure difference adjustment portion is performed by adjusting the difference between the flow rate V2 of the air in the duct unit  54  and the flow rate V1 of the air in the exhaust duct  6 . Specifically, by causing the air to flow from the outside to the inside of the duct unit  54 , a flow rate V3 (m 3 /sec) is generated that is different from the flow rate V2, and the flow rate (V2+V3) is brought closer to the flow rate V1, thereby stabilizing the flow of air inside the circulation portion  44 . Note that an “adjusted state of the pressure difference ΔP” refers not only to a state in which the flow rate V3 is changed as appropriate, but also includes a state in which the flow rate V3 has already been adjusted. 
     As illustrated in  FIG.  6   , when the first duct  56  and the second duct  76  are viewed from the negative Z direction, an interval in the Y direction between the outer wall surface  64 A and the inner wall surface  78 A is L1 (mm), and an interval in the Y direction between the outer wall surface  65 A and the inner wall surface  79 A is L2 (mm). For example, L1 is equal to L2. Further, when the first duct  56  and the second duct  76  are viewed from the negative Z direction, an interval in the Y direction between the inner surface, in the positive Y direction, of the through hole  73  and the inner surface, in the positive Y direction, of the ventilation hole  85  is L3 (mm), and an interval in the Y direction between the inner surface, in the negative Y direction, of the through hole  58  and the inner surface, in the negative Y direction, of the ventilation hole  85  is L4 (mm). For example, L3 is equal to L4. 
     Next, actions of the printer  10  according to the first embodiment will be described with reference to  FIG.  1    to  FIG.  7   . The numbers of individual drawings will be omitted below. 
     The air fed to the inside of the feeding unit  32  by the rotation of the first fan  38  flows toward the space  41 . On the other hand, due to the rotation of the second fan  52  in the suction unit  42 , air and foreign material, such as ink mist, sucked from the space  41  are discharged to the exhaust duct  6  through the duct unit  54 . In this case, a flow rate difference ΔV between the flow rate V1 of the exhaust device  4  and the flow rate V2 of the second fan  52  is generated, but outside air flows from the opening portions  86  into the duct unit  54 , that is, the flow rate V3 is added to the flow rate V2, and thus, the flow rate V1 and the flow rate V2+V3 are balanced. In other words, the pressure difference ΔP between the pressure P1 and the pressure P2 is reduced. 
     As described above, according to the printer  10 , when the discharge capacity of the exhaust device  4  is greater than the discharge capacity of the suction unit  42  provided in the printer  10 , the pressure P1 inside the duct unit  54  is lower than the pressure outside the duct unit  54 , that is, lower than the pressure P2 of the exhaust duct  6 . Here, the pressure P1 inside the duct unit  54  is increased by the outside air flowing through the opening portions  86  and into the duct unit  54 . In other words, by adjusting the pressure P1 to a value close to the pressure P2, the pressure difference ΔP can be reduced. Thus, even if the discharge capacity of the exhaust device  4  is greater than the discharge capacity of the suction unit  42  provided in the printer  10 , the air flow around the recording unit  20  and the air flow inside the suction unit  42  can be prevented from being disturbed by the air discharge by the exhaust device  4 . 
     According to the printer  10 , since it is sufficient only to provide the opening portions  86  provided on the side portions  61 A and  61 B of the duct unit  54 , the pressure difference adjustment unit can be realized by a simple configuration, compared to a configuration in which a unit for adjusting the pressure difference ΔP is attached to the duct unit  54 . 
     According to the printer  10 , the opening portion  86  that is the gap between the inner wall surface  78 A and the outer wall surface  64 A, and the opening portion  86  that is the gap between the inner wall surface  79 A and the outer wall surface  65 A respectively function as the hole portions. Here, the second duct  76  is in a state of covering the first duct  56  from upstream in the positive Z direction, and thus, even if dust falls in the positive Z direction from the ceiling of the installation location of the printer  10 , the dust can be prevented from entering the first duct  56  and the second duct  76  through the opening portions  86 . 
     According to the printer  10 , compared to a configuration in which the peripheral edge portion of the ventilation hole  73  in the upper wall  72  is along the horizontal direction, the air can easily flow in the direction in which the upper wall  72  is inclined. As a result, the air can be suppressed from stagnating in a part of the suction unit  42 . 
     Note that the air discharged from the suction unit  42  may contain foreign material. Here, according to the printer  10 , the filter  98  is detachably provided inside the third duct  92 . Thus, foreign material in the air can be recovered by the filter  98 , and the filter  98  that is contaminated by the foreign material can be easily replaced. 
     According to the printer  10 , a part of the circulation portion  44  is partitioned by the third side wall  65 , in the space between the recording unit  20  and the second fan  52 . Here, when a part of the air that has not been sucked into the second fan  52  stagnates and flows toward the recording unit  20 , the third side wall  65  restricts the flow of this part of the air. In this way, the air that has flowed downstream from the space  41  between the recording unit  20  and the support face  18  can be suppressed from once more flowing into the space  41  and contaminating the medium M. 
     According to the printer  10 , compared to a configuration in which a part of the third side wall  65  is along the horizontal direction, the air can easily flow in the direction in which the part of the third side wall  65  is inclined. Thus, the air can be prevented from stagnating in a part of the circulation portion  44  of the suction unit  42 . 
     Second Embodiment 
     Next, as an example of the recording device according to the present disclosure, a printer  100  according to a second embodiment will be described in detail with reference to the appended drawings. Note that the same reference signs are assigned to components common to the first embodiment, and a description thereof will be omitted. Further, even when the dimensions of the members differ from those of the first embodiment, the same reference signs will be assigned where the function is the same, and a description thereof will be omitted. 
     As illustrated in  FIG.  8   , with respect to the printer  10  ( FIG.  7   ), the printer  100  has a configuration in which a dimension in the Y direction of the second duct  76  and a dimension in the Y direction of the third duct  92  are respectively set to be the same as the dimension in the Y direction of the first duct  56 . In other words, in the printer  100 , the opening portions  86  ( FIG.  7   ) are not formed. Furthermore, the printer  100  differs from the configuration of the printer  10  in that the printer  100  includes a pipe  102  and a valve  104 . 
     In the second duct  76 , no hole portion is formed in the first vertical wall  78 . One ventilation hole  106 , which penetrates the second vertical wall  79  in the Y direction, is formed in the central portion, in the X direction, of the second vertical wall  79 , for example. 
     The ventilation hole  106  is an example of the hole portion, and is formed in a circular shape as viewed from the Y direction. Note that a “configuration in which a hole portion is provided in a target member” does not only include a configuration in which another member in which the through hole is formed is provided on the target member, but also includes a configuration in which the through hole is formed directly in the target member. 
     For example, the pipe  102  is formed in a cylindrical shape and extends in the Y direction. An end portion in the positive Y direction of the pipe  102  is coupled to the ventilation hole  106  and an edge portion of the ventilation hole  106 . In this way, the pipe  102  can achieve communication between the inside of the duct unit  54  and the outside of the duct unit  54 , that is, the outside of the printer  100 . In other words, the pipe  102  is configured to allow air to flow from outside the printer  10  into the duct unit  54 . 
     The valve  104  is provided in the pipe  102  and is configured so as to be able to adjust the flow rate of air flowing inside the pipe  102 . Specifically, the valve  104  includes a handle  105  operated by a user. Rotation of the handle  105  to one side increases the flow of the air flowing through the interior of the pipe  102 . Further, the rotation of the handle  105  to the other side reduces the flow of the air flowing through the interior of the pipe  102 . Here, in a state in which the pipe  102  is closed and the exhaust device  4  ( FIG.  1   ) is in operation, the pressure inside at least the second duct  76  is lower than the pressure outside the printer  100 . Thus, when the handle  105  is rotated to open the pipe  102 , air flows from the outside of the printer  100  into the second duct  76 , through the pipe  102 . 
     Note that the valve  104  may be electrically controllable, such as an electromagnetic valve. Further, a first air pressure sensor (not illustrated) is provided outside the second duct  76 , and a second air pressure sensor (not illustrated) is provided inside the second duct  76 , and a control unit (not illustrated) that controls the valve  104  is provided. According to this configuration, the control unit can control the valve  104  such that a difference between an output from the first air pressure sensor and an output from the second air pressure sensor is equal to or less than a chosen set value, and the trouble of the operation of the user can be eliminated. In this case, as long as the difference in pressure between the pressure outside the second duct  76  and the pressure inside the second duct  76  can be detected, positions where the first air pressure sensor (not illustrated) and the second air pressure sensor (not illustrated) are provided may be adjusted as appropriate. 
     Next, actions of the printer  100  according to the second embodiment will be described. Note that a description of the same actions and effects as those of the printer  10  will be omitted. 
     According to the printer  100 , by adjusting the flow rate of the air flowing inside the pipe  102  in accordance with a degree of opening of the valve  104 , the pressure difference ΔP between the pressure inside the duct unit  54  and the pressure outside the duct unit  54  can be reduced. In this way, the pressure difference ΔP can be changed depending on the capacity of the exhaust device  4  in the installation location where the printer  100  is installed. 
     The printers  10  and  100  according to the first and second embodiments of the present disclosure are based on the configurations described above. However, of course, modifications, omissions, and the like may be made to a partial configuration insofar as they do not depart from the gist of the disclosure of the present application. 
       FIG.  9    illustrates a printer  110  as a modified example of the printer  100  according to the second embodiment. Note that reference will be made to  FIG.  8    in relation to the configuration of the printer  100 . 
     In the printer  110 , the ventilation hole  106  is not formed, and the printer  110  does not include the pipe  102  and the valve  104 . In the printer  110 , for example, four ventilation holes  112  are respectively formed in the first vertical wall  78  and the second vertical wall  79 . Here, the four ventilation holes  112  in the first vertical wall  78  will be described, and an illustration and description of the four ventilation holes  112  in the second vertical wall  79  will be omitted. 
     The four ventilation holes  112  are an example of the hole portion, and penetrate the first vertical wall  78  in the Y direction. Further, the four ventilation holes  112  are formed in the first vertical wall  78  at intervals in the X direction. For example, the shape of the ventilation hole  112  is a square shape. Further, the flow path cross-sectional area of the ventilation hole  112  is determined by performing a fluid simulation so that the pressure difference ΔP described above is reduced. 
     According to the printer  110 , since it is sufficient that the four ventilation holes  112  only be formed in the side portions  61 A and  61 B, respectively, of the duct unit  54 , the pressure difference adjustment unit can be realized by a simple configuration, compared to a configuration in which a unit for adjusting the pressure difference ΔP is attached to the duct unit  54 . 
     In the printers  10  and  100 , the pressure difference adjustment unit may be configured using a louver. Further, an adjustment structure may be used in which the pressure difference adjustment unit is configured by a plurality of opening portions and lid portions capable of opening and closing the opening portions, and in which the flow rate difference ΔV between the flow rate V1 and the flow rate V2, or the pressure difference ΔP is reduced by causing some of the opening portions to be closed and causing the remaining opening portions to be open. 
     The pressure difference adjustment unit may be formed in the first duct  56 . 
     The exhaust duct  6  may be coupled to the second duct  76  without providing the third duct  92 . The first duct  56  and the second duct  76 , the second duct  76  and the third duct  92 , or the first duct  56 , the second duct  76 , and the third duct  92  may be configured as one integrated member. 
     The opening portion  86  is not limited to being formed over the entire X direction of the second duct  76 , and may be formed at a portion, in the X direction, of an end portion in the positive Z direction of the second duct  76 . 
     The upper wall  72  may extend along the horizontal direction. 
     The filter  98  is not limited to being provided in the third duct  92 , and may be provided in the first duct  56  or the second duct  76 . In other words, the position of the filter  98  can be freely set as long as the filter  98  is downstream of the second fan  52 . 
     The lower portion  67  of the third side wall  65  need not necessarily extend into the interior of the circulation portion  44 . In other words, a portion of the circulation portion  44  need not necessarily be partitioned using the third side wall  65 . 
     In place of the inclined wall  69 , a wall portion extending along the horizontal direction may be provided. 
     Examples of the medium M include a film, in addition to the fabric and the sheet. A method for aligning the transport of the medium M may be either of a center resist method using a center position in the X direction as a reference, or a side resist method using a position of one of the ends in the X direction as the reference. 
     The recording unit  20  is not limited to performing the recording in a serial manner as in the recording head  21 , and may perform the recording in a line head manner. Further, as the recording unit  20 , a fixing mechanism for fixing a toner, including a color material, to the medium M may be employed. In other words, the printers  10 ,  100  and  110  may employ an electrophotographic method. 
     The support unit is not limited to a belt, and may be a pallet that supports the medium M and is moved in the transport direction. 
     A known diaphragm pump may be employed instead of the first fan  38  and the second fan  52 . 
     A transport belt functioning as the support unit is not limited to the glue belt  17 , and belts using various adsorption power inducing mechanisms can be used, such as an electrostatic attraction method using electrostatic forces generated by applying a voltage, a vacuum suction method using a compressor, an intermolecular force method using an adhesive, and the like. 
     Further, the transport belt is not limited to the endless belt that is caused to move in the revolving manner. For example, the transport belt may be a flat belt (a belt having an end) that is taken up by a roller as the roller rotates. When the belt having the end is employed, it is sufficient that the cleaning unit  26  be configured to clean the outermost surface of a portion, of the belt having the end, that is taken up by the roller.