Patent Publication Number: US-10766276-B2

Title: Ink jet printing apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2018-69203, filed on Mar. 30, 2018 and Japanese Patent Application No. 2018-123917, filed on Jun. 29, 2018. The above applications are hereby expressly incorporated by reference, in its entirety, into the present application. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is related to an inkjet printing apparatus having an inkjet heat that ejects ink. 
     2. Description of the Related Art 
     Conventionally, inkjet printing apparatuses that perform printing by ejecting ink from an inkjet head to a print medium such as paper and film have been proposed. In addition, printing processes are also being administered to building materials, decorative panels, etc. using such an inkjet printing apparatus. 
     SUMMARY OF THE INVENTION 
     Here, in the case that a building material formed by an aluminum series sintered material (hereinafter, simply referred to as “aluminum sintered material”) is employed as a print medium, the aluminum sintered material is coated to a preliminary processing fluid in a preliminary process, the preliminary processing fluid is dried, and then a printing process is administered. 
     However, in the case that an aluminum sintered material which s coated with, for example, a preliminary processing fluid, is placed directly on a table of an inkjet printing apparatus and the aluminum sintered material is heated from above and dried, it is possible to evaporate the preliminary processing fluid which is contained in a porous material in the vicinity of the surface of the aluminum sintered material. However, the drying efficiency is low with respect to the preliminary processing fluid contained in the porous material in the interior of the aluminum sintered material and in the vicinity of the back side, that is, the side toward the table of the inkjet printing apparatus. This is because water vapor, which is generated by heating, is trapped by the table and cannot escape. The low drying efficiency results in a problem of decreased productivity. In addition, water droplets adhere on the side of the table. Therefore, the aluminum sintered material will be in close contact with the table, and there are problems that handling properties deteriorate and that the surface of the back side of the aluminum sintered body will become soiled. 
     Japanese Unexamined Patent Publication No. H10-217572 proposes to employ a mesh member as a platen when heating a printed sheet from the back side thereof on a platen. However, if only a mesh member is used, water vapor will still remain on the surface of the substrate after drying. As a result, drying speed decreases and it becomes difficult for the printed sheet to dry. In addition, when printing on a large sized substrate with the same apparatus, flatness cannot be secured, and therefore image quality will deteriorate. 
     In addition, Japanese Unexamined Patent Publication No. H7-25007 proposes to provide a print medium on a support portion having an opening through which water vapor is capable of passing, and to provide a condensation inducing portion for condensation of water vapor that has passed through the opening, when drying the print medium. However, a mechanism for processing the condensed liquid is necessary, and this configuration is not sufficient to dry a porous material such as the aluminum sintered material described above in a short amount of time. 
     The present invention has been developed in view of the foregoing circumstances. It is an object of the present invention to provide an inkjet printing apparatus, which is capable of improving the drying efficiency of a print medium when drying a liquid such as preliminary processing fluid 
     An inkjet printing apparatus of the present invention is an inkjet printing apparatus that ejects ink from an inkjet head to a print medium to perform printing, comprising a drying unit for drying a liquid which is contained in the print medium, a table on which the print medium is placed, and a gas flow generating unit for generating a gas flow in a space which is formed between the table and a surface of the print medium toward the side of the table. 
     According to the inkjet printing apparatus of the present invention, in the case that a liquid which is contained in a print medium is to be dried, a space is formed between the table and the surface of the print medium toward the side of the table, and gas flow is generated in the formed space by the gas flow generating unit. Therefore, the drying efficiency of the print medium can be improved, and as a result, productivity can be improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view that illustrates the schematic configuration of an inkjet apparatus according to a first embodiment. 
         FIG. 2  is a collection of diagrams that illustrate an example of a support member constituted by a plurality of lifting units. 
         FIG. 3  is a diagram that illustrates the schematic configuration of a shuttle unit. 
         FIG. 4  is a perspective view that illustrates the outer appearance of an inkjet head. 
         FIG. 5  is a diagram that illustrates the lifting units and a flow straightening member as viewed from above. 
         FIG. 6  is a block diagram that illustrates a control system of the inkjet printing apparatus of the first embodiment illustrated in  FIG. 1 . 
         FIG. 7A  is a diagram for explaining the operation of the inkjet printing apparatus of the first embodiment illustrated in  FIG. 1 . 
         FIG. 7B  is a diagram for explaining the operation of the inkjet printing apparatus of the first embodiment illustrated in  FIG. 1 . 
         FIG. 7C  is a diagram for explaining the operation of the inkjet printing apparatus of the first embodiment illustrated in  FIG. 1 . 
         FIG. 7D  is a diagram for explaining the operation of the inkjet printing apparatus of the first embodiment illustrated in  FIG. 1 . 
         FIG. 7E  is a diagram for explaining the operation of the inkjet printing apparatus of the first embodiment illustrated in  FIG. 1 . 
         FIG. 8  is a plan view that illustrates another shape of the lifting units. 
         FIG. 9  is a diagram that illustrates an example of a suction type gas flow generating unit. 
         FIG. 10  is a diagram that illustrates an example of a support member, which is placed on a flat bed unit. 
         FIG. 11  is a perspective view that illustrates the schematic configuration of an inkjet apparatus according to a second embodiment. 
         FIG. 12  is a diagram for explaining the operations of the lifting units and a position determining member. 
         FIG. 13  is a diagram for explaining an example of a relationship between the upper surface of the position determining member and the thickness of a print medium during a printing operation. 
         FIG. 14  is a cross sectional diagram of the second inkjet printing apparatus illustrated in  FIG. 11  taken along line A-A. 
         FIG. 15A  is a collection of explanatory diagrams for explaining the operation of the inkjet printing apparatus of the second embodiment illustrated in  FIG. 11   
         FIG. 15B  is a collection of explanatory diagrams for explaining the operation of the inkjet printing apparatus of the second embodiment illustrated in  FIG. 11   
         FIG. 15C  is a collection of explanatory diagrams for explaining the operation of the inkjet printing apparatus of the second embodiment illustrated in  FIG. 11   
         FIG. 15D  is a collection of explanatory diagrams for explaining the operation of the inkjet printing apparatus of the second embodiment illustrated in  FIG. 11   
         FIG. 15E  is a collection of explanatory diagrams for explaining the operation of the inkjet printing apparatus of the second embodiment illustrated in  FIG. 11   
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, a first embodiment of an inkjet printing apparatus of the present invention will be described in detail with reference to the drawings.  FIG. 1  is a schematic diagram that illustrates the configuration of an inkjet printing apparatus  1  of the present embodiment. Note that  FIG. 1  is a diagram that illustrates a state in which a support member  40  to be described later is accommodated in a flat bed unit  3 . In addition, in the description of the embodiments described below, the up, down, left, right, front, and back directions indicated by arrows in  FIG. 1  are defined as the up, down, left, right, front, and back directions of the inkjet printing apparatus  1 . 
     As illustrated in  FIG. 1 , the inkjet printing apparatus  1  of the present embodiments equipped with a shuttle base unit  2 , the flat bed unit  3 , a shuttle unit  4 , a drying unit  50 , a preliminary processing unit  6 , and a gas flow generating unit  60 . 
     A shuttle base unit  2  supports the shuttle unit  4 , the drying unit  50 , and the preliminary processing unit  6 , and moves the shuttle unit  4 , the drying unit  50 , and the preliminary processing unit  6  in the front-back direction (sub scanning direction). Specifically, the shuttle base unit  2  is equipped with a mount portion  11  and a sub scanning drive motor  12  (refer to  FIG. 6 ). 
     The mount portion  11  is formed in the shape of a rectangular frame, and supports the shuttle unit  4 , the drying unit  50 , and the preliminary processing unit  6 . Sub scanning drive guides  13 A and  13 B that extend in the front-back directions are respectively formed on the left and right sides of the mount portion  11 . The sub scanning drive guides  13 A and  13 B guide the shuttle unit  4 , the drying unit  50 , and the preliminary processing unit  6  such that these elements move in the front-back directions. 
     The flat bed unit  3  supports a print medium  15 , which is the aforementioned building material or decorative panel formed by a porous material. Note that an aluminum sintered material is an example of the building material formed by a porous material. An aluminum sintered material is formed by molding aluminum powder into the shape of a plate by sintering. However, the print medium  15  having the porous material is not limited to an aluminum sintered material, and other base materials may be employed. In addition, in the present embodiment, the flat bed unit  3  corresponds to the table of the present invention. 
     The flat bed unit  3  is provided within a rectangular parallelepiped shaped recess, which is formed in the interior of the mount portion  11  of the shuttle base unit  2 . The flat bed unit  3  has a medium placement surface  3   a , which is a horizontal surface on which the print medium  15  is placed. The flat bed unit  3  has a hydraulic driving mechanism or the like, which is omitted from the figure and is configured to adjust the height of the medium placement surface  3   a.    
     In addition, the support member  40  to be described later is housed within the flat bed unit  3 , and passage apertures  3   b , through which the support member  40  passes when the support member  40  protrudes from the flat bed unit  3 , are formed in the medium placement surface  3   a  of the flat bed unit  3 . The passage apertures  3   b  are formed according to the shape of the support member  40 . In the present embodiment, the passage apertures  3   b  are formed as rectangular shapes that extend in the front-back directions. 
     The support member  40  of the present embodiment is equipped with a plurality of lifting units  41 , which are formed as rectangular parallelepipeds that extend in the horizontal direction. The plurality of lifting units  41  are provided such that the direction that they extend in is parallel to the direction of gas flow which is generated by the gas flow generating unit  60 . During a printing operation, the plurality of lifting units  41  are housed within the flat bed unit  3 , as illustrated in the upper portion of  FIG. 2 . Meanwhile, during a drying operation of the print medium  15  and during a gas flow generating operation to be described later, the lifting units  41  move upward as illustrated in the lower portion of  FIG. 2 , and protrude from the medium placement surface  3   a  of the flat bed unit  3 . A support member elevating mechanism  30  that moves the lifting units  41  in the up-down direction (vertical direction) is provided within the flat bed unit  3 . The support member elevating mechanism  30  has a predetermined actuator. 
     By causing the lifting units  41  to protrude from the medium placement surface  3   a  of the flat bed unit  3  with the support member elevating mechanism  30 , a space can be formed between the print medium  15  which is placed on the lifting units  41  and the flat bed unit  3 . The gas flow which is generated by the gas flow generating unit  60  can flow through the space. 
     Meanwhile, when conducting a printing operation, the support member elevating mechanism  30  moves the lifting units  41  downward, to house the lifting units  41  within the flat bed unit  3 . Thereby, the print medium  15  can be directly placed on the medium placement surface  3   a  of the flat bed unit  3 . Therefore, the flatness (horizontal property) of the print medium  15  can be secured, and the image quality of a printed image will be guaranteed. 
     Regarding the relationship between the lifting units  41  and the spaces among the lifting units  41 , the area of the portions where the lifting units  41  and the print medium  15  are in contact with each other is smaller than the area of the entire lower surface of the print medium  15 , preferably ⅔ the area or less. It is more preferable for the area of the portions where the lifting units  41  and the print medium  15  are in contact with each other to be ½ or less than the area of the entire lower surface of the print medium  15 , and still more preferably ⅓ or less. In the case of the support member  40  of the present embodiment, if the width in the direction orthogonal to the direction that the lifting units  41  extend is designated as L 1 , and the width in the direction perpendicular to the direction of the spaces among lifting units  41  is designated as L 2 . It is preferable for L 1 ≤2×L 2 , more preferably L 1 ≤L 2 , and still more preferably L 1 ≤L 2 /2, as illustrated in  FIG. 2 . 
     The shuttle unit  4  administers a printing process on the print medium  15 .  FIG. 3  is a diagram that illustrates the schematic configuration of the shuttle unit  4 . Note that  FIG. 3  illustrates a state in which a flow straightening member  43  to be described later is provided on the flat bed unit  3  and the print medium  15  is provided on the lifting units  41  of the support member  40 . 
     As illustrated in  FIG. 3 , the shuttle unit  4  is equipped with a casing  21 , a main scanning drive guide  22 , a main scanning drive motor  23  (refer to  FIG. 6 ), a head elevation guide  24 , a head elevating motor  25  (refer to  FIG. 6 ), and a head unit  26 . 
     The casing  21  houses each of the above components, such as the head unit  26 . The casing  21  is formed in the shape of a gate that straddles the flat bed unit  3  in the left-right direction. The casing  21  is supported by the mount portion  11  of the shuttle base unit  2  and is configured to be movable along the sub scanning drive guides  13 A and  13 B. 
     The main scanning drive guide  22  guides the head unit  26  such that it moves in the left-right direction (main scanning direction). The main scanning drive guide  22  is formed by an elongated member that extends in the left-right direction. The head unit  26  is moved in the left-right direction by the main scanning drive motor  23 . 
     The head elevation guide  24  guides the head unit  26  such that it moves in the vertical direction. The head elevation guide  24  is formed by a member having an elongated shape in the vertical direction. The head elevation guide  24  is configured to be movable in the left-right direction along the main scanning drive guide  22  together with the head unit  26 . The head unit  26  is moved up-down in the vertical direction by a head elevating motor  25 . 
     As described above, the head unit  26  performs a print process by ejecting ink to the print medium  15  while moving in the left-right direction along the main scanning drive guide  22 . The head unit  26  has four inkjet heads  31 , as illustrated in  FIG. 3 . 
       FIG. 4  is a perspective view that illustrates the outer appearance of an inkjet head  31 . As illustrated in  FIG. 4 , the inkjet head  31  has a nozzle plate  35  and a nozzle guard  36 . The nozzle plate  35  has a nozzle row in which a plurality of nozzles  37  for ejecting ink are arranged in the front to rear direction. 
     The nozzle guard  36  protects an ink ejection surface  35   a  of the nozzle plate  35 , has an opening  38  in a portion corresponding to the nozzle row of the nozzle plate  35 . The nozzle guard  36  is provided on the ink ejection surface  35   a  of the nozzle row. The opening  38  of the nozzle guard  36  is formed in a rectangular shape which is elongated in the front to rear direction, and is formed such that all the nozzles  37  are exposed. 
     Four of the inkjet heads  31  are arranged in the left-right direction such that they are parallel to each other. The four inkjet heads  31  eject inks of different colors (cyan, black, magenta and yellow, for example). 
     Returning to  FIG. 1 , the preliminary processing unit  6  performs preliminary processing by applying a preliminary processing fluid to the print medium  15 , which is formed by a porous material. In the present embodiment, the preliminary processing unit  6  is provided forward of the drying unit  50 . Configurations for applying the preliminary processing fluid to the print medium  15  may be configurations similar to the head unit  26  and the main scanning guide  22  provided within the shuttle unit  4 , to which preliminary processing fluid is supplied instead of ink. Such a configuration may eject the preliminary processing fluid onto the print medium  15 . Alternatively, a configuration may be adopted, in which a brush or a blade on which the preliminary processing fluid is coated is moved in the left-right direction (main scanning direction) to coat the print medium  15  with the preliminary processing fluid. 
     The preliminary processing unit  6  is supported by the mount portion  11  of the shuttle base unit  2  and is configured to be movable along the sub scanning drive guides  13 A and  13 B. The preliminary processing unit  6  sequentially applies the preliminary processing fluid to a predetermined range on the print medium  15  underneath the preliminary processing unit  6  by moving in the sub scanning direction. 
     The drying unit  50  evaporates the liquid that is absorbed in the print medium  15 , which is formed by a porous material (preliminary processing fluid and ink in the present embodiment). The drying unit  50 , which is provided between the shuttle unit  4  and the preliminary processing unit  6  the present embodiment, is equipped with a heater that extends in the left-right direction (main scanning direction). 
     The drying unit  50  is supported by the mount portion  11  of the shuttle base unit  2  and is configured to be movable along the sub scanning drive guides  13 A and  13 B. The drying unit  50  sequentially heats areas underneath it by moving in the sub scanning direction, and sequentially evaporates the liquid which is contained within the print medium  15 , to dry the print medium  15 . The drying unit  50  may be that which has a fan and a heating means such as a heater or the like and blows hot air toward the print medium  15 . Alternatively, the drying unit  50  may be that which has an infrared light source and irradiates the print medium  15  with infrared rays. 
     A gas flow generating unit  60  is provided on the frame of the front end portion of the mount portion  11 . The gas flow generating unit  60  generates a gas flow that flows from the front side to the rear side of the shuttle base unit  2  to generate a gas flow in the space  42  (refer to  FIG. 3 ) which is formed among the lifting units  41  described above. Specifically, the gas flow generating unit  60  is provided with one or a plurality of fans, and generates the gas flow by driving the one or more fans. In addition, the gas flow generating unit  60  is preferably provided with heating means such as a heater in addition to the one or more fans to generate a flow of warm gas. By adopting such a configuration, the drying efficiency of the print medium  15  can be improved. 
     In addition, in the present embodiment, flow straightening members  43 , which are rectangular parallelepiped shaped members, are provided at both sides in the left-right direction of the support member  40  constituted by the plurality of lifting units  41 , in order to cause the gas flow generated by the gas flow generating unit  60  to flow efficiently into the spaces  42  among the lifting units  41 , as illustrated in  FIG. 3  and  FIG. 5 . Note that  FIG. 5  is a diagram that illustrates the lifting units  41  and the flow straightening members  43  as viewed from above. The flow straightening members  43  may be configured to be detachable from the flat bed unit  3  or may be fixed on the flat bed unit  3 . 
     Note that an intake unit (not illustrated) having an air intake aperture may be provided at the rear end side of the lifting units  41 , in order to cause the gas flow generated in the gas flow generating unit  60  to flow more efficiently into the space  42  of the support member  40 . 
     In addition, in the present embodiment, the support member  40  is provided in the flat bed unit  3  such that the direction in which the lifting units  41  extend matches the sub scanning direction. However, the present invention is not limited to such a configuration. For example, the gas flow generating unit  60  may be provided on the frame at the left or right end of the mount portion  11  so as to generate a gas flow flowing from the left side to the right side or the right side to the left side of the shuttle base unit  2 . In this case, the support member  40  may be provided in the flat bed unit  3  such that the direction in which the lifting units  41  extend matches the left-right direction (main scanning direction). That is, it is only necessary for the direction of the gas flow generated by the gas flow generating unit  60  to match with the direction in which the lifting units  41  extend. 
       FIG. 6  is a block diagram that illustrates the control system of the inkjet printing apparatus  1  of the present embodiment. The inkjet printing apparatus  1  is equipped with a control section  5  that controls the entire apparatus. The control section  5  is configured by a computer having a CPU (Central Processing Unit), a semiconductor memory, a hard disk, etc. The control section  5  controls each part illustrated in  FIG. 6  by executing a program which is stored in advance in a storage medium such as a semiconductor memory or a hard disk, and by operating an electric circuit. 
     In addition, as illustrated in  FIG. 6 , the inkjet printing apparatus  1  is provided with an operation panel  61 . The operation panel  61  is configured by, for example, a touch panel. The operation panel  61  displays various pieces of information such as an operation menu, and accepts various setting inputs from a user. Specifically, the operation panel  61  accepts setting inputs related to a printing process such as printing density, setting inputs of a heating temperature for the drying unit  50  described above, and setting inputs of gas flow volume and gas flow speed for the gas flow generating unit  60 . The control section  5  controls each section based on data which are set and input via the operation panel  61 . 
     Next, the operation of the inkjet printing apparatus  1  of the present embodiment will be described with reference to  FIGS. 7A through 7E .  FIGS. 7A through 7E  illustrate the inkjet printing apparatus  1  illustrated in  FIG. 1  as viewed from the left side thereof. 
     First, a print medium  15  is placed on lifting units  41  in a state in which the lifting units  41  are protruding from flat bed unit  3 , as illustrated in  FIG. 7A . Next, the control section  5  controls the sub scanning drive motor  12  to move the preliminary processing unit  6  in the forward direction (the direction of the arrow illustrated in  FIG. 7B ) and operates the preliminary processing unit  6  to apply the preliminary processing fluid to print medium  15 , to perform a preliminary process. 
     Then, after the preliminary processing fluid is applied to the print medium  15  by the preliminary processing unit  6 , the control section  5  controls the sub scanning drive motor  12  to move the drying unit  50  forward (the direction of the arrow illustrated in  FIG. 7C ). 
     At this time, the control section  5  sequentially heats the printing medium  15  along the forward direction by operating the drying unit  50  while moving the drying unit  50 , the preliminary processing fluid contained in the print medium  15  evaporates, and the print medium  15  is dried. In addition, the control section  5  generates gas flow in the spaces  42  among the lifting units  41  by operating the gas flow generating unit  60  simultaneously with the drying operation of the drying unit  50 . By the gas flow being generated, it is possible to smoothly exhaust the evaporated gas from the back side (underside) of the print medium  15 , and to promote drying of the print medium  15 . 
     Then, when the drying unit  50  moves to the drying operation completed position (the front end of  FIG. 7C ), the control section  5  causes the operation of the drying unit  50  and the gas flow generating unit  60  to cease, controls the support member elevating mechanism  30  to move the lifting units  41  downward such that they are housed in the flat bed unit  3 . As a result, the print medium  15  is placed directly on the medium placement surface  3   a  of the flat bed unit  3  as illustrated in  FIG. 7D . The distance between the print medium  15  and the head unit  26  is adjusted thereafter. Specifically, adjustments are conducted such that the distance Z (refer to  FIG. 7D ) between the print medium  15  placed on the medium placement surface  3   a  of the flat bed unit  3  and the inkjet head  31  in the shuttle unit  4  is 1.5 mm±0.5 mm. The distance between the print medium  15  and the head unit  26  may be adjusted by moving the head unit  26  in the vertical direction, or by moving the flat bed unit  3  in the vertical direction. 
     Next, the control section  5  controls the sub scanning drive motor  12  to perform a printing process while moving the shuttle unit  4  in the forward direction (the direction of the arrow illustrated in  FIG. 7D ), as illustrated in  FIG. 7D . Specifically, the control section  5  moves the shuttle unit  4  to a print start position on the print medium  15 . By controlling the main scanning drive motor  23  to move the head unit  26  in the main scanning direction, while controlling the inkjet head  31  based on an input print job to eject ink from the nozzle  37 , printing for one pass is performed. 
     After printing for one pass is completed, the control section  5  controls the sub scanning drive motor  12  to move the shuttle unit  4  forward to the printing position of a next pass. The control section  5  forms an image on the print medium  15  by alternately repeating the printing of single passes and movement of the shuttle unit  4 . 
     When the printing of one sheet is completed, the shuttle unit  4  is placed at the initial position again, as illustrated in  FIG. 7E . Thereafter, the control section  5  controls the support member elevating mechanism  30  to move the lifting units  41  upward such that they protrude from the flat bed unit  3  again. Next, the control section  5  controls the sub scanning drive motor  12  to move the drying unit  50  in the backward direction (the direction of the arrow illustrated in  FIG. 7E ), as illustrated in  FIG. 7E . 
     At this time, the control section  5  sequentially heats the printing medium  15  along the backward direction by operating the drying unit  50  while moving the drying unit  50 , to dry the ink which is attached to the print medium  15 . In addition, the control section  5  generates a gas flow in the spaces  42  among the lifting units  41  by operating the gas flow generating unit  60  simultaneously with the drying operation of drying unit  50 . By the gas flow being generated, it is possible to smoothly exhaust the evaporated gas from the back side (underside) of the print medium  15 , and to promote drying of the print medium  15 . 
     Thereafter, the control section  5  ceases the drying operation and the gas flow generating operation described above when the drying unit  50  reaches the rear end initial position illustrated in  FIG. 7E . Next, control section  5  the places preliminary processing unit  6  in the rear end initial position illustrated in  FIG. 7A , and the series of operations ends. 
     Note that post processing is not conducted in the above description. However, post processing may be conducted after printing depending on the type of print medium  15  or the type of ink. In this case, it is preferable for a post processing liquid to be applied to the print medium  15  after printing and then to carry out the drying operation and gas flow generating operation described above in a state in which the lifting units  41  are protruding from the flat bed unit  3 . 
     Regarding a post processing unit for applying the post processing liquid to the print medium  15 , for example, the post processing liquid may be supplied to the preliminary processing unit  6  instead of the preliminary processing fluid such that the preliminary processing unit  6  functions as both a preliminary processing unit and a post processing unit. Alternatively, a post processing unit having a similar configuration to that of the preliminary processing unit  6  may be provided separately. 
     In addition, in the embodiment described above, rectangular parallelepiped members that extend in the sub scanning direction are employed as the lifting units  41 . However, the present invention is not limited to such a configuration. For example, lifting units having columnar shape that extend in the up-down direction (vertical direction) may automatically enter and exit through the medium placement surface  3   a  of the flat bed unit  3 .  FIG. 8  is a plan view of lifting units  49  having the aforementioned columnar shapes that extend in the up-down direction. As illustrated in  FIG. 8 , it is preferable for the cylindrical lifting units  49  to be arranged uniformly on the medium placement surface  3   a  of the flat bed unit  3 . In addition, it is preferable for the plurality of columnar lifting units  49  to be spaced apart from each other along an orthogonal direction (the left-right direction in the present embodiment) with respect to direction in which the gas flow is blown (the front-back direction in the present embodiment) by the gas flow generating unit  60 . By adopting such a configuration, it will become possible to cause the gas flow generated by the gas flow generating unit  60  to flow efficiently among the lifting units  49 , and also to secure the flatness of the print medium  15 . 
     In addition, in the embodiment described above, a space is formed between the print medium  15  and the flat bed unit  3  by causing the lifting units  41  to protrude from the flat bed unit  3 . However, the present invention is not limited to employing the lifting units  41 . Other possible configurations may be that which grip the edges of the print medium and lift the print medium  15  upward, or that which suctions the print medium  15  to lift the print medium  15  upward. Such alternate configurations are also capable of forming a space between the print medium  15  and the flat bed unit  3 . That is, any configuration may be employed as long as a space can be formed between the print medium  15  and the flat bed unit  3 . 
     As still another alternative, a surface having concavities and convexities (grooves) may be formed in the medium placement surface  3   a  of the flat bed unit  3  itself, instead of providing the lifting units  41  as in the embodiment described above. A space may be formed between the print medium  15  and the flat bed unit  3  by the grooves achieving a configuration similar to the state in which the lifting units  41  are protruding. 
     In addition, a fan is employed as the gas flow generating unit  60  in the embodiment described above, and the gas flow is generated by blowing wind which is generated by the fan. However, the gas flow generating unit is limited to such a configuration. For example, in a configuration in which the lifting units  41  described above automatically enter and exit the flat bed unit  3 , suctioning apertures  3   c  may be provided among the lifting units  41  and a suctioning pipe  47  within the flat bed unit  3  may be connected to the suctioning apertures  3   c . A gas flow may be generated in the spaces among the lifting units  41 , by suctioning air with a suction pump  48  connected to the suctioning pipe  47  to suction air. By generating the gas flow by suction in this manner, the influence imparted by wind on the periphery can be decreased compared to the case in which the gas flow is generated by blowing with a fan as in the embodiment described above. 
     In addition, in the embodiment described above, the lifting units  41  are housed in the flat bed unit  3  and the lifting units  41  automatically protrude to form a space between the print medium  15  and the flat bed unit  3 . However, the present invention is not limited to this configuration. A space may be formed between the flat bed unit  3  and the print medium  15  by placing the print medium  15  on a support member which is formed separately on the flat bed unit  3 . 
       FIG. 10  is a diagram that illustrates an example of a support member  44  described above, which is placed on the flat bed unit  3  described above. Specifically, as illustrated in  FIG. 10 , the support member  44  is a plate shaped member having a predetermined thickness, and includes a plurality of protruding portions  45  having a rectangular parallelepiped shape extending in one direction in the horizontal direction, and recessed portions  46   a  which are formed in the protruding portions  45 . The size (outer periphery) of the support member  44  is larger than the size of the print medium  15  which is expected to undergo a printing operation, and the print medium  15  is placed on the support member  44 , to form the space with the recessed portions  46 . 
     Regarding the relationship between the protruding portions  45  and the recessed portions  46  (spaces), the area of the portion where the support member  44  and the print medium  15  are in contact is smaller than the area of the entire lower surface of the print medium  15 , and is preferably ⅔ or less. It is more preferable for the area to be ½ or less, and still more preferably ⅓ or less. In the case that the support member  44  illustrated in  FIG. 10  is employed, if the width in the direction perpendicular to the direction in which the protruding portions  45  extend is designated as L 3  and the width in the direction perpendicular to the direction in which the recessed portions  46  extend is designated as L 4 , it is preferable for L 3 ≤2×L 4  to be satisfied, more preferably L 3 ≤L 4 , and still more preferably L 3 ≤L 4 /2. 
     The support member  44  is placed on the flat bed unit  3  such that the direction in which the protruding portions  45  extend matches with the sub scanning direction. In the present embodiment, the protruding portions  45  are formed as rectangular parallelepiped shapes that extend in the front-back direction (sub scanning direction). Therefore, it is possible for the gas flow which is generated by the gas flow generating unit  60  to flow efficiently within the recessed portions  46  of the support member  44 , for the drying efficiency of the print medium  15  which is placed on the support member  44  to be improved. 
     In addition, it is possible to form a space easily between the print medium  15  and the flat bed unit  3  simply by placing the support member  44  on the flat bed unit  3 . Further, if the support member  44  is removed from the flat bed unit  3 , the print medium  15  can be placed directly on the flat bed unit  3 , and the flatness of the print medium  15  can be secured thereby. 
     In addition, in the embodiment described above, the drying operation by the drying unit  50  and the gas flow generating operation by the gas flow generating unit  60  are performed to dry the preliminary processing fluid and the post processing liquid contained in the print medium  15 . The amount of preliminary processing fluid and post processing liquid which is contained in print medium  15  may vary depending on the thickness of the print medium  15  and the size of the porous material. 
     Therefore, a table in which information regarding types of the print medium  15  with control conditions of the drying unit  50  and the gas flow generating unit  60  are correlated may be set in the control section  5 , for example. The control conditions of the drying unit  50  and the gas flow generating unit  60  may be determined based on information regarding the type of the print medium  15  which is input as a setting. Thereby, it becomes possible for the print medium  15  to be appropriately dried even in cases that the thickness of the print medium and the size of the porous material are different. 
     Information regarding the types of the print medium  15  may be the product information of the print medium  15 , information indicating thickness, or information indicating the size of the porous material. The information regarding the type of print medium  15  may be set and input via the operation panel  61 , or may be set and input in a printer driver (computer) that outputs a print job to the inkjet printing apparatus  1 . In addition, as for the thickness of the print medium  15 , for example, control may be exerted by classifying thicknesses into three levels, such as thin, middle, and thick, and the control conditions may be changed for three levels, which may be less than 3 mm, 3 mm or greater and less than 5 mm, and 5 mm or greater. 
     In addition, the heating temperature is a control condition of the drying unit  50 . In the case that a fan is employed as the drying unit  50 , gas flow volume and wind speed may also be included as control conditions. Further, gas flow volume and wind speed are control conditions of the gas flow generating unit  60 . In the case that the gas flow generating unit  60  is that which generates warm gas, the temperature of the warm gas may also be included as a control condition. 
     Further, in the case that the drying operation and the gas flow generating operation are performed in order to dry the ink after a printing process, a table in which the total amounts of ejected ink required for printing processes and control conditions for the drying unit  50  and the gas flow generating unit  60  are correlated may be prepared. Control conditions for the drying unit  50  and the gas flow generating unit  60  may be determined based on the total amount of ejected ink. Note that the gas flow volume and the gas flow speed are set to be greater and the temperature is also set to be higher as the total amount of ejected ink increases. 
     The total amount of ejected ink may be set via the operation panel  61 , or may be set and input in a printer driver (computer) that outputs a print job to the inkjet printing apparatus  1 . Alternatively, the total amount of ejected ink may be calculated from the data size of image data to be printed, which is included in the print job. 
     In the inkjet printing apparatus  1  of the embodiment described above, the shuttle unit  4  is moved relative to the print medium  15  (flat bed unit  3 ) to perform scanning in the sub scanning direction. However, the present invention is not limited to such a configuration. Alternatively, the shuttle unit  4  may be fixed and the print medium  15  (flat bed unit  3 ) may be moved, or both of the shuttle unit  4  and the print medium  15  (flat bed unit  3 ) may be moved. 
     In the embodiment described above, the position in the up down direction of the print medium  15  may be adjusted according to the thickness of the print medium  15 . Specifically, if the thickness of print medium  15  is thick, the lifting units  41  or  49  may be lowered to lower the position of print medium  15 , and the thickness of print medium  15  is thin, the lifting units  41  or  49  may be raised to raise the position of the print medium  15 , for example. By adopting such a configuration, it will become possible to maintain the distance between the print medium  15  and the drying unit  50  at a constant distance, and the drying efficiency can be maintained. As a method for adjusting the position of the print medium  15 , not only can the lifting units  41  or  49  be raised and lowered, but also the flat bed unit  3  may be raised and lowered in the up down direction. Further, after roughly adjusting the position of the print medium  15  by adjusting the height of the flat bed unit  3 , fine adjustments may be performed by raising and lowering the lifting units  41  or  49 . In addition, as another method for maintaining the distance between the print medium  15  and the drying unit  50  constant, the drying unit  50  may be raised and lowered employing an adjusting mechanism that includes a predetermined actuator. 
     Next, an inkjet printing apparatus  10  according to a second embodiment of the present invention will be described in detail.  FIG. 11  is a schematic diagram that illustrates the configuration of the inkjet printing apparatus  10  of the second embodiment. The inkjet printing apparatus  10  of the second embodiment differs from the inkjet printing apparatus  1  of the first embodiment equipped with the gas flow generating unit  60  illustrated in  FIG. 1  in that the inkjet printing apparatus  10  has a suctioning mechanism in order to further expedite drying after the print medium  15  is coated with the preliminary processing fluid. In addition, the inkjet printing apparatus  10  is provided with position determining members capable of positioning the print medium  15  such that it does not shift during printing. Further, the mounting position and the configuration of a gas flow generating unit  70  differs from those of the inkjet printing apparatus  1  of the first embodiment. The position determining members are members that determine the position of the print medium  15  on the medium placement surface  3   a  (within the horizontal plane). Note that configurations which are similar to those of the inkjet printing apparatus  1  of the first embodiment are denoted by the same reference numerals and descriptions thereof will be omitted. The inkjet printing apparatus  10  of the second embodiment will be described in detail hereinafter, focusing on the points of difference from the inkjet printing apparatus  1  of the first embodiment. 
     The inkjet printing apparatus  10  of the present embodiment has the cylindrical lifting units  49  and the position determining members  80  (refer to  FIG. 12 ). The lifting units  49  and the position determining members  80  are configured to be capable of being housed in the flat bed unit  3 .  FIG. 11  is a diagram that illustrates a state in which the lifting units  49  and position determining members  80  are housed in the flat bed unit  3 . 
     As illustrated in  FIG. 11 , first passage apertures  3   d , through which the lifting units  49  pass when they protrude from the flat bed unit  3 , and a second passage apertures  3   e , through which the positioning determining members  80  pass when they protrude from the flat bed unit  3 , are formed in the surface of the flat bed unit  3 . The first passage apertures  3   d  are formed according to the shape of the lifting units  49 . In the present embodiment, the first passage apertures  3   d  are formed as circular shapes. The second passage apertures  3   e  are formed according to the shape of the position determining members  80 . In the present embodiment, the second passage apertures  3   e  are formed in rectangular shapes and an L shape. 
     As in the first embodiment, the plurality of lifting units  49  are accommodated in the flat bed unit  3  during a printing operation as illustrated in the upper portion of  FIG. 12 . Meanwhile, during a drying operation of the print medium  15  and a gas flow generating operation, which will be described later, the lifting units  49  move upward and protrude from the medium placement surface  3   a  of the flat bed unit  3  as illustrated in the lower portion of  FIG. 12 . A support member elevating mechanism  30  that moves the lifting units  49  in the up-down direction (vertical direction) is provided within the flat bed unit  3 . The support member elevating mechanism  30  has a predetermined actuator. 
     By causing the lifting units  49  to protrude from the medium placement surface  3   a  of the flat bed unit  3  employing the support member elevating mechanism  30  in this manner, a space is formed between the print medium  15  and the flat bed unit  3  placed on the lifting units  49 . Thereby, a gas flow generated by the gas flow generating unit  70  can flow through the space. Meanwhile, when performing a printing operation, the support member elevating mechanism  30  moves the lifting units  49  downward, and the lifting units  49  are housed in the flat bed unit  3 , as described above. As a result, the print medium  15  can be placed directly on the medium placement surface  3   a  of the flat bed unit  3 , so that the flatness (horizontal property) of the print medium  15  can be secured and the image quality of the printed image will be guaranteed. 
     Rectangular parallelepiped position determining members  80  having a rectangular cross section in the horizontal direction and a wall shaped position determining member  80  having an L shaped cross section in the horizontal direction that extend in the vertical direction are provided as the position determining members  80 . The L shaped position determining member  80  is provided at the right corner of the front end of the flat bed unit  3  as indicated by the second passage aperture  3   e  at this position in  FIG. 11 . The position determining members  80  having rectangular parallelepiped shapes are provided to face an upper exhaust port  70   a  and a lower exhaust port  70   b  of the gas flow generating unit  70  to be described later. A plurality of the position determining members  80  having rectangular parallelepiped shapes are provided at the peripheral edge of the flat bed unit  3  that extends in the sub scanning direction, and a plurality of the position determining members  80  having rectangular parallelepiped shapes are provided on the peripheral edge of the front end of the flood bed unit  3  that extends in the main scanning direction. In addition, the position determining members  80  are arranged such that the gas flow passes over the entirety of the medium placement surface  3   a  during the drying operation, in order to remove the water vapor which is generated on the upper surface and the lower surface of the print medium  15 . In the present embodiment, the rectangular parallelepiped position determining members  80  are arranged in the front-back direction and the left-right direction along the horizontal extending direction of the L-shaped position determining member  80 . More specifically, as indicated by the second passage apertures in  FIG. 11 , four rectangular parallelepiped position determining members  80  are arranged in the front-back direction, and two rectangular parallelepiped position determining members  80  are arranged in the left-right direction. 
     The gas flow generating unit  70  is configured to move in the sub scanning direction (front-back direction) while blowing gas flow radially or unidirectionally in the front-back direction from the upper exhaust port  70   a  and the lower exhaust port  70   b . The gas flow generating unit  70  is configured to such that the gas flow generated thereby is efficiently suctioned by the position determining members  80 , a plurality of which are arranged in the front-back direction and the let-right direction on the flat bed unit  3 . Note that with respect to the number of position determining members  80 , it is preferable for at least two or more position determining members  80  to be provided for one gas flow generating unit  70 , in order to suction the gas flow generated by the gas flow generating unit  70  and to position the print medium  15 . In addition, in the present embodiment, the gas flow generating unit  70  is configured to move in the sub scanning direction. However, instead of the gas flow generating unit  70  moving in this manner, a plurality of gas flow generating units  70  may be arranged side by side in the sub scanning direction, and a gas flow may be blown radially or unidirectionally from each of the respective gas flow generating units  70 . In addition, a single gas flow generating unit  70  may be fixedly provided so as to blow a gas flow in a broad radial direction toward the entirety of the medium placement surface  3   a  of the flood bed unit  3 . 
     In addition, a position determining member elevating mechanism  90  (refer to  FIG. 12 ) that moves the position determining members  80  in the up-down direction (vertical direction) is provided in the flat bed unit  3 . The position determining member elevating mechanism  90  has a predetermined actuator. 
     During a printing operation, the plurality of position determining members  80  protrude from the medium placement surface  3   a  of the flat bed unit  3  to a predetermined height, as illustrated in the upper portion of  FIG. 12 . Regarding this height, a height H 2  from the medium placement surface  3  a on the upper surface of the position determining members  80  is set to be less than or equal to a thickness H 1  of the print medium  15  which is placed on the medium placement surface  3   a , as illustrated in  FIG. 13 . By setting the height of the position determining members  80  as described above, it is possible to position the print medium  15  within the medium placement surface  3   a  by bringing the print medium  15  into contact with the position determining members  80 . In addition, it is possible to prevent the shuttle unit  4  (head unit  26 ), which is positioned above the print medium  15  during the printing operation, from colliding with the position determining members  80 . 
     Meanwhile, during a drying operation of the preliminary processing fluid and ink of the print medium  15  and a gas flow generating operation, the plurality of position determining members  80  move further upward than during the printing operation, as illustrated in the lower portion of  FIG. 12 . The upper surfaces of the position determining members  80  move to a position H 3  higher than the upper surface of the print medium  15  which is placed on the lifting units,  49  as illustrated in  FIG. 13 . As illustrated in  FIG. 12 , suction ports  81  are formed on the inner surface of each of the position determining members  80  on the side toward the print medium  15 . The position determining members  80  suction the gas flow through these suction ports  81 . By raising the position determining members  80  up to the aforementioned position H 3  and performing the suction operation during the drying operation of the print medium  15  and the gas flow generating operation, the gas flow which is generated by the gas flow generating unit  70  on the upper side and the lower side of the print medium  15  can be efficiently suctioned. As a result, drying efficiency can be improved. That is, the gas flow which is generated radially from the gas flow generating unit  70  is suctioned and collected by the position determining members  80  which are provided at positions that face the gas flow generating unit  70 . Thereby, it becomes possible to cause the gas to flow at a greater speed across the upper side and the lower side of the print medium  15 , thereby improving the drying efficiency of the print medium  15 . In addition, since it is possible to control the flow velocity distribution of the gas flow that flows on the upper side and the lower side of the print medium  15 , the print medium  15  can be prevented from being dried unevenly. 
     In addition, by providing the position determination members  80  with a suctioning mechanism for suctioning the gas flow (both the gas flow generated during internal circulation to be described later and gas flow generated during exhaust to the exterior) blown from the gas flow generating unit  70 , it will be unnecessary to provide members for positioning and a suctioning mechanism. As a result, the apparatus can be miniaturized, and cost reduction can also be achieved. 
     Note that the suction ports  81  are not necessarily provided in all of the position determining members  80 , but may be provided at least in the position determining members  80  arranged at positions that face the gas flow generating unit  70 . That is, in the case of the present embodiment, it is not necessary to provide the suction ports  81  in the two position determining members  80  which are arranged in the left-right direction. 
     In the present embodiment, two rectangular suction ports  81  are formed arrayed in the up-down direction in each position determining members  80 , as illustrated in  FIG. 12 . However, the shape and number of the suction ports  81  are not limited to such a configuration. One, or three or more suction ports  81  may be formed, and circular or elliptical suction ports  81  may be provided. 
     The configurations of the shuttle unit  4 , the drying unit  50  and the preliminary processing unit  6  are the same as those of the first embodiment described above. 
     In the inkjet printing apparatus  10  of the present embodiment, a sub scanning drive guide  13 C is provided on the left side surface of the mount portion  11  of the shuttle base unit  2 , as illustrated in  FIG. 11 . The sub scanning drive guide  13 C guides the gas flow generating unit  70  to move in the front-back direction. The gas flow generating unit  70  of the present embodiment is installed on the left side surface of the mount portion  11  which is provided with the sub scanning drive guide  13 C, and is moved in the front-back direction together with the drying unit  50  by the sub scanning drive motor  12 . 
     The gas flow generating unit  70  of the present embodiment generates a gas flow flowing from the left side to the right side of the shuttle base unit  2  to generate gas flows at the upper side and the lower side of the print medium  15  which is supported by lifting units  49 . Specifically, the gas flow generating unit  70  is provided with one or a plurality of fans, and generates the gas flow by driving the one or more fans. In addition, the gas flow generating unit  70  of the present embodiment has the upper exhaust port  70   a  and the lower exhaust port  70   b , as illustrated in  FIG. 11 .  FIG. 14  is a cross sectional view of the inkjet printing apparatus  10  illustrated in  FIG. 11  in the direction of the arrow A-A that illustrates a in which the lifting units  49  and position determining members  80  are protruding from the flat bed unit  3  and the print medium  15  is placed on the lifting units  49 . 
     As illustrated in  FIG. 14 , the gas flow generating unit  70  is configured such that it is located near the bottom of the drying unit  50 . The upper exhaust port  70   a  is located above the upper surface of the print medium  15  which is expected to undergo a printing operation, and the lower exhaust port  70   b  is located below the lower surface of the print medium  15 . By causing the gas flow which is exhausted from the upper exhaust port  70   a  to flow along the upper side of the print medium  15  and by causing the gas flow which is exhausted from the lower exhaust port  70   b  along the lower side of the print medium  15 , it becomes possible to efficiently generate gas flows at both sides of the print medium  15 . As a result, drying of the print medium  15  can be promoted further. 
     Note that the gas flow generating unit  70  may be raised or lowered in the vertical direction according to the type of print medium  15  in order to generate gas flow more efficiently at both sides of the print medium  15 . The gas flow generating unit  70  may be configured such that the distance between the upper exhaust port  70   a  and the lower exhaust port  70   b  is changeable according to the thickness of print medium  15 . 
     In addition, it is not necessary for the gas flow generating unit  70  to have two exhaust ports. A configuration may be adopted in which gas flow which is exhausted from one exhaust port flows on both sides of the print medium  15 . Further, it is preferable for the wind speed of the gas flow generated by the gas flow generating unit  70  to be within a range from 7 msec to 9 m/sec. Drying can be accelerated by setting the wind speed to 7 m/sec or greater, and heat generated by the drying unit  50  can be efficiently circulated by setting the wind speed to 9 msec or less. 
     The gas flow which is exhausted from the gas flow generating unit  70  is suctioned by the suction ports  81  of the position determining members  80  after passing through the upper side and the lower side of the print medium  15 . 
     An intake pipe  85 , a first filter  82 , a second filter  83 , a fan section  84 , a vent pipe  86 , an exhaust pipe  87 , and a circulation pipe  88  are provided in the mount portion  11  of the shuttle base unit  2 . These elements constitute a circulation exhaust mechanism. By operation of the fan section  84 , the gas flow is suctioned from the suction ports  81  of the position determining members  80 , and the gas flow which is suctioned flows through the first filter  82  and the second filter into the circulation pipe  88 , to return to the gas flow generating unit  70  (internal circulation), or is exhausted to the exterior of the apparatus by the exhaust pipe  87  (exhaust to the exterior) 
     One end of the intake pipe  85  is connected to the suction ports  81  within the position determining members  80  and the other end is connected to the first filter  82 . The gas flow which is suctioned through the suction ports  81  of the position determining members  80  is supplied to the first filter  82 . 
     The first filter  82  is a filter that removes moisture from the gas flow supplied thereto, and is constituted by a silica gel zeolite filter, for example. Note that the first filter  82  is not limited to being a silica gel zeolite filter, and other known filters may be employed, as long as they are capable of removing moisture. The gas flow, from which the moisture has been removed by the first filter  82 , is supplied to the second filter  83  via the vent pipe  86 . 
     The second filter  83  is a filter that removes odors from the gas flow supplied thereto, and is constituted by an activated carbon filter, for example. Note that the second filter  83  is not limited to being an activated carbon filter, and any other known filter may be used as long as they are capable of removing odors. The gas flow from which the odors are removed by the second filter  83  is supplied to the fan section  84  via the vent pipe  86 . 
     If the amount of moisture in the gas flow supplied to the second filter  83  is great, there is a risk of influencing the performance and durability of the second filter  83 . Therefore, although it is preferable to provide the second filter  83  that removes odors at a stage after the first filter  82  that removes moisture as in the present embodiment, the present invention is not limited to this order of filters. That is, the first filter  82  may be provided at a stage after the second filter  83 . 
     In addition, two filters are provided in the present embodiment. However, but the present invention is not limited to such a configuration. Only one of the filters may be provided, or a plurality of types of filters that remove odors may be provided, for example. 
     The fan section  84  is equipped with a fan and a switching section for switching the exhaust destination of gas flow supplied thereto between the circulation pipe  88  and the exhaust pipe  87 . The fan section  84  performs the suction operation through the suction port  81  of the position determining members  80  by operating the fan under the control of the control section  5 , and operates the switching section to switch between exhaust to the circulation pipe  88  and exhaust to the exhaust pipe  87 . 
     In the case that exhaust is switched to the exhaust to the circulation pipe  88  by the switching section, the gas flow supplied to the fan section  84  is supplied to the gas flow generating unit  70 , and is exhausted from the upper exhaust port  70   a  and the lower exhaust port  70   b  again, and then suctioned through the suction ports  81  of the position determining members  80 . Thereby, the gas flow internally circulates within the apparatus. In contrast, in the case that exhaust is switched to the exhaust pipe  87  by the switching section, the gas flow supplied to the fan section  84  is discharged to the exterior of the apparatus. 
     Regarding the switching between the exhaust to the circulation pipe  88  and the exhaust to the exhaust pipe  87 , in the case that the amount of preliminary processing fluid applied to the print medium  15  is great or the amount of ink is great, the amount of moisture in the circulating gas flow will increase. As a result, the moisture will not be removed by the gas flow passing through the first filter  82 , and there is a possibility that the drying time of the print medium  15  will become long. Therefore, in such a case, the fan section  84  causes the gas flow to be internally circulated in the apparatus so that the gas flow passes through the first filter  82  a plurality of times. Thereby, the drying of the print medium  15  can be promoted further. Conversely, if the preliminary processing fluid and the ink amount are not considerably great, it is not necessary for the gas flow to pass through the first filter  82  a plurality of times. Therefore, the fan section  84  exhausts the gas flow to the exhaust pipe  87  such that the gas flow is exhausted to the exterior. 
     Depending on the amount or the type of preliminary processing fluid and ink which is applied to the print medium  15 , there may be a strong odor in the vicinity of the flood bed unit  3  and the print medium  15  itself may also have a strong odor immediately after coating. There are cases in which the aforementioned second filter  83  cannot completely remove the order. As a result, the odor in the vicinity of the apparatus will become stronger, and the working environment may deteriorate. Therefore, in such a case, the fan section  84  exhausts the gas flow to the exhaust pipe  87  without internally circulating the gas flow within the apparatus in order to exhaust the gas flow to the exterior, thereby diffusing the odor and decreasing the concentration of the odor, to improve the working environment. Conversely, if the odor of the preliminary processing fluid and the ink amount is not strong, the fan section  84  exhausts to the circulation pipe  88  to internally circulate the gas flow. This makes it possible to increase the utilization efficiency of warm air. 
     With regard to the above-described exhaust switching in the fan section  84 , a user may set and input switching commands, or the switching may be conducted automatically. In the case that switching of the exhaust destination from the fan section  84  is conducted automatically, the control section  5  may obtain information regarding the amount of preliminary processing fluid or the total amount of ejected ink required for printing processing, and employs a preset profile, table or the like to conduct automatic switching according to the amount, for example. Alternatively, the control section  5  may acquire information regarding the type of preliminary processing fluid or ink, and conduct automatic switching according to the type by employing a preset profile, table, or the like. Information regarding the amount or the type of preliminary processing fluid or information regarding the total amount of ejected ink or ink type may be set by user input or may be included in the print job, and the control section  5  may be obtain the information from the print job. 
     Further, the amount of moisture circulating in the apparatus may be measured directly, and switching between exhaust to the circulating pipe  88  (internal circulation) and exhaust to the exhaust pipe  87  (exhaust to the exterior) may be performed based on the results of measurement. Specifically, a measurement unit that measures the amount of moisture of the gas flow may be provided between the first filter  82  and the second filter  83 , between the second filter  83  and the fan section  84 , or the like. In the case that the amount of moisture measured by the measurement unit is less than a threshold value which is set in advance, the control section  5  may switch exhaust to the exhaust pipe  87 . In the case that the amount of moisture measured by the measurement unit is greater than or equal to the threshold value, the control section  5  may switch exhaust to the circulation pipe  88 . In addition, the control section  5  may monitor the amount of moisture of gas flow in real time, and switch from exhaust to the circulation pipe  88  to exhaust to the exhaust pipe  87  in the case that the amount of moisture becomes less than the threshold value from being greater than or equal to the threshold value. 
     Regarding control systems of the inkjet printing apparatus  10  of the present embodiment, it is the same as that of the inkjet printing apparatus  1  of the first embodiment, other than control systems specific to the present embodiment. 
     Next, the operation of the ink presentation apparatus  10  of the present embodiment will be described with reference to  FIGS. 15A through 15E .  FIGS. 15A through 15E  are a collection of diagrams of the inkjet printing apparatus  10  illustrated in  FIG. 1 , as viewed from the left side. 
     First, as illustrated in  FIG. 15A , the print medium  15  is placed on the lifting units  49  in a state in which the lifting units  49  and the position determining members  80  are protruding from the flat bed unit  3 . At this time, it is preferable for the print medium  15  to be places such that one corner of the print medium  15  abuts the L shaped position determining members  80 , and the two sides of the print medium  15  that form the corner abut the rectangular parallelepiped position determining members  80 . However, a certain degree of clearance may be provided between the print medium  15  and the position determining members  80  during the preliminary process. 
     Next, the control section  5  controls the sub scanning drive motor  12  to move the preliminary processing unit  6  in the forward direction (the direction of the arrow illustrated in  FIG. 15B ) and causes the preliminary processing unit  6  to operate, to coat the print medium with the preliminary processing fluid, to administer the preliminary process. 
     After the print medium  15  is coated with the preliminary processing fluid by the preliminary processing unit  6 , the control section  5  controls the sub scanning drive motor  12  to move the drying unit  50  and the gas flow generating unit  70  in the forward direction (the direction of the arrow illustrated in  FIG. 15C ) as illustrated in  FIG. 15C . 
     In addition, the control section  5  sequentially heats the printing medium  15  along the forward direction by operating the drying unit  50  while moving the drying unit  50  at this time. Thereby, the preliminary processing fluid contained in the print medium  15  evaporates and dries. Further, the control section  5  generates gas flow above and below the print medium  15  by operating the gas flow generating unit  70  simultaneously with the drying operation of the drying unit  50 . Still further, the control section  5  performs the suction operation through the suction ports  81  of the position determining members  80  by operating the fan section  84  simultaneously with the generation of the gas flow by the gas flow generating unit  70 . 
     The inkjet printing apparatus  10  of the present embodiment promotes drying of the preliminary processing fluid on the surfaces of the print medium  15  by generating the gas flow by the gas flow generating unit  70  and suctioning by the position determining members  80 . The inkjet printing apparatus  10  further promotes drying of the print medium  15  by smoothly exhausting gas which evaporates from the back side (lower side) of the print medium  15 . 
     In addition, the inkjet printing apparatus  10  of the present embodiment is capable of removing the moisture from the gas flow by passing the gas flow which is suctioned through the suction ports  81  of the position determining members  80  through the first filter  82 , thereby further promoting drying. As another benefit of this feature, rusting of metal components can be prevented. 
     In addition, the inkjet printing apparatus  10  of the present embodiment is capable of removing unpleasant odors from the gas flow by passing the gas flow which is suctioned through the suction ports  81  of the position determining members  80  through the second filter  83 . Thereby, it is possible to prevent the odors from spreading in the vicinity of the apparatus, and it is possible to improve the working environment for operators. 
     Then, when the drying unit  50  and the gas flow generating unit  70  move to a drying operation completion position (the front end in  FIG. 15C ), the control section  5  ceases the operations of the drying unit  50 , the gas flow generating unit  70 , and the fan section  84 . Thereafter, the control section  5  controls the support member elevating mechanism  30  to move the lifting units  49  downward such that they are housed in the flat bed unit  3 . As a result, the print medium  15  is placed directly on the medium placement surface  3   a  of the flat bed unit  3 , as illustrated in  FIG. 15D . 
     Also, the control section  5  controls the position determining member elevating mechanism  90  to move the position determining members  80  downward, such that the upper surfaces of the position determining members  80  are below the upper surface of print medium  15  and above the medium placement surface  3   a  of the flat bed unit  3 . Then, positioning of the print medium  15  is performed by the user again. That is, the user causes one corner of the print medium  15  to abut the L shaped position determining members  80  and causes the two sides that form the corner to abut the rectangular parallelepiped position determining members  80 . By positioning the print medium  15  in this manner, it is possible to ensure the positional accuracy of the image printed on the print medium  15 . 
     Thereafter, the distance between the print medium  15  and the head unit  26  is adjusted. Specifically, the distance Z (refer to  FIG. 15D ) between the print medium  15 , which is placed on the medium placement surface  3   a  of the flat bed unit  3 , and the inkjet head  31  within the shuttle unit  4  is adjusted to be 1.5 mm±0.5 mm. The distance between the print medium  15  and the head unit  26  may be adjusted by moving the head unit  26  in the up-down direction, or by moving the flat bed unit  3  in the up-down direction. 
     Next, the control section  5  controls the sub scanning drive motor  12  to perform a printing process while moving the shuttle unit  4  in the forward direction (the direction of the arrow illustrated in  FIG. 15D ), as illustrated in  FIG. 15D . Specifically, the control section  5  moves the shuttle unit  4  to a printing start position above the print medium  15 . By controlling the main scanning drive motor  23  to move the head unit  26  in the main scanning direction, the inkjet head  31  is controlled based on the input print job to eject ink from the nozzle  37 , thereby performing printing for a single pass. 
     After printing for the single pass is completed, the control section  5  controls the sub scanning drive motor  12  to move the shuttle unit  4  forward to a printing position for a next pass. The control section  5  forms an image in print medium  15  by alternately repeating printing for single passes movement the of shuttle unit  4 . 
     At a point in time when printing of one sheet is completed, the shuttle unit  4  is arranged at the initial position again, as illustrated in  FIG. 15E . The control section  5  then controls the support member elevating mechanism  30  to move the lifting units  49  upward, and controls the position determining member elevating mechanism  90  to move the position determining members  80  upward. Thereby, the lifting units  49  and the position determining members  80  are caused to protrude from the flat bed unit  3  again. 
     Next, the control section  5  controls the sub scanning drive motor  12  to move the drying unit  50  and the gas flow generating unit  70  in the backward direction (the direction of the arrow illustrated in  FIG. 15E ), as illustrated in  FIG. 15E . 
     At this time, the control section  5  sequentially heats the printing medium  15  along the forward direction by operating the drying unit  50  while moving the drying unit  50 , to dry the ink which is attached to the print medium  15 . In addition, the control section  5  generates gas flows above and below print medium  15  by operating the gas flow generating unit  70  simultaneously with the drying operation of the drying unit  50 . Further, the control section  5  causes the fan section  84  to operate simultaneously with the generation of the gas flows by the gas flow generating unit  70 , to perform suction through the suction ports  81  of the position determining members  80 . 
     The inkjet printing apparatus  10  of the present embodiment promotes the drying of ink on the surface of the print medium  15  by the generation of the gas flows by the gas flow generating unit  70  and the suctioning by the position determining members  80 . In addition, drying of the print medium  15  is further promoted by smoothly exhausting gas which evaporates on the back side (underside) of the print medium  15 . 
     In addition, the inkjet printing apparatus  10  of the present embodiment is configured to causes the gas flow, which is suctioned by the suction ports  81  of the position determining members  80 , to pass through the first filter  82  and the second filter  83 , so that moisture and odor are removed. 
     The control section  5  then stops the drying operation, the gas flow generating operation and the suction operation described above when the drying unit  50  and the gas flow generating unit  70  are arranged at the back end initial position illustrated in  FIG. 15E . Next, the control section  5  arranges the preliminary processing unit  6  at the back end initial position illustrated in  FIG. 15A , and the series of processes is completed. 
     In the description above, a post process is performed. However, a post process may be performed after printing, depending on the type of the print medium  15  or the type of ink. In this case, the print medium  15  is coated with a post processing liquid after printing, and it is preferable for the drying operation, the gas flow generating operation, and the suctioning operation described above to be performed in a state in which the lifting units  49  and the position determining members  80  are protruding from the flat bed unit  3 . 
     In the inkjet printing apparatus  10  of the second embodiment, the six rectangular parallelepiped position determining members  80  are moved in the up-down direction. However, the position determining members  80  to be moved in the up-down direction may be selected according to the size of the print medium  15 . For example, in the case that a comparatively large print medium  15  is employed, all six of the rectangular parallelepiped position determining members  80  are moved in the up-down direction, as in the second embodiment described above. In the case that a comparatively small print medium  15  is used, only the two position determining members  80  which are closer to the L shaped position determining members  80  from among the four rectangular parallelepiped position determining members  80 , for example, may be moved in the up-down direction. That is, in the case that the size of the print medium  15  is comparatively small, only the rectangular parallelepiped position determination members  80  close to the L shaped position determining members  80  from among the six rectangular parallelepiped position determining members  80  may be moved in the up-down direction. 
     Specifically, a table or the like in which the sizes of print media  15  and the position determining members  80  to be moved in the up-down direction are correlated with each other may be set in the control section  5  in advance. In this case, the control section  5  may refer to the table based on input information regarding the size of a print medium  15 , and control the position determining member elevating mechanism  90  to select the position determining members  80  to be moved in the up-down direction. 
     The information regarding the size of the print medium  15  may be input and set by a user, or may be information included in a print job which is obtained. Alternatively, the size of a print medium  15  which is placed on the flatbed unit  3  may be detected by employing an optical sensor or the like. 
     Note that the position determining members  80  may be divided into blocks as the position determining members  80  of the second embodiment described above are, or may be of an integrated unitary shape. 
     In addition, in the case that the inkjet printing apparatuses  1  and  10  of the first and second embodiments are configured such that the gas flow generating units  60 ,  70  are capable of generating warm gas flow, warm gas flow and cold gas flow may be switched according to the amount or the type of preliminary processing fluid or the total amount of ejected ink. That is the, control section  5  may switch to cold air when the amount of preliminary processing fluid or total amount of ejected ink is small, and switch to warm air when these amounts are large. Alternatively, in the case that a preliminary processing fluid or ink which is likely to volatilize is employed, the control section  5  may switch to cold gas flow, and in the case that a preliminary processing fluid or ink which is not likely to volatilize is employed, the control section  5  may switch to warm gas flow. By switching between cold gas flow and warm gas flow in this manner, electrical power consumption can be reduced. Note that the method for obtaining information regarding the amount or the type of preliminary processing fluid, the total amount of ejected ink, or the type of ink is the same as that which was described previously. 
     The following additional items are disclosed with respect to the inkjet printing apparatus of the present invention. 
     The inkjet printing apparatus of the present invention may be provided with a support member on the table that forms a space between the surface of the print medium toward the table and the table. 
     In addition, in the inkjet printing apparatus of the present invention, the support member may be of a columnar shape that extends in the vertical direction or a rectangular parallelepiped shape that extends in the horizontal direction. 
     In addition, in the inkjet printing apparatus of the present invention, the support member may be columnar, and a plurality of columnar support members may be provided along a direction perpendicular to the direction of the gas flow which is generated by the gas flow generating unit with intervals therebetween such that the gas flow can pass therethrough. 
     In addition, the inkjet printing apparatus of the present invention may be equipped with an elevating mechanism for raising and lowering the support member in the vertical direction. 
     In addition, the inkjet printing apparatus of the present invention may be equipped with a support member elevating mechanism for raising and lowering the support member in the vertical direction. The support member elevating mechanism may raise the support member upward in the vertical direction during the gas flow generating operation of the gas flow generating unit to form the space, and lower the support member downward in the vertical direction during a printing operation. 
     In addition, in the inkjet printing apparatus of the present invention, it is possible to provide an adjusting mechanism for adjusting the position of at least one of the print medium and the drying unit according to the thickness of print medium. 
     In addition, in the inkjet printing apparatus of the present invention, the gas flow generating unit may be capable of generating gas flow by suctioning gas from within in the space. 
     In addition, the inkjet printing apparatus of the present invention may be provided with a control section that exerts control such that a drying operation by the drying unit and a gas flow generating operation by the gas flow generating unit are simultaneously performed. 
     In addition, the inkjet printing apparatus of the present invention may be provided with a control section for controlling at least one of the drying unit and the gas flow generating unit according to the type of the print medium. 
     In addition, the inkjet printing apparatus of the present invention may be provided with a position determining member that positions the print medium within a placement surface for the print medium. The position determining member may have a suctioning mechanism for suctioning the gas flow which is generated by the gas flow generating unit. 
     In addition, the inkjet printing apparatus of the present invention may be provided with a position determining member elevating mechanism for raising and lowering the position determining member. The position determining member elevating mechanism may move the position determining member upward in the vertical direction during a gas flow generating operation by the gas flow generating unit, and move the position determining member downward in the vertical direction during a printing operation. 
     In addition, the inkjet printing apparatus of the present invention may be provided with a filter, through which gas flow which is suctioned by the suctioning mechanism of the position determining member passes, that removes moisture or odor included in the gas flow. 
     In addition, the inkjet printing apparatus of the present invention may be provided with a switching section that switches between internal circulation and exhaust to the exterior of the gas flow which has passed through the filter, according to the amount or the type of liquid that the print medium is coated with. 
     In addition, the inkjet printing apparatus of the present invention may employ a filter that removes moisture which is included in the gas flow as the filter, and may be equipped with a switching section that switches between internal circulation and exhaust to the exterior of the gas flow which has passed through the filter, according to the amount of moisture which is included in the gas flow. 
     EXPLANATION OF THE REFERENCE NUMERALS 
     
         
           1  ink jet printing apparatus 
           2  shuttle base unit 
           3  flatbed unit 
           3   a  medium mounting surface 
           3   b  passage aperture 
           3   c  suctioning aperture 
           3   d  first passage aperture 
           3   e  second passage aperture 
           4  shuttle unit 
           5  control unit 
           10  ink jet printing apparatus 
           11  gantry section 
           12  sub scanning drive motor 
           13 A,  13 B,  13 C sub scanning drive guide 
           15  printing medium 
           21  casing 
           22  main scanning drive guide 
           23  main scanning drive motor 
           24  head elevating guide 
           25  head elevating motor 
           26  head unit 
           30  support member elevating mechanism 
           31  ink jet head 
           35  nozzle plate 
           35   a  ink ejection surface 
           36  nozzle guard 
           37  nozzle 
           38  opening 
           40  support member 
           41  lifting unit 
           42  space 
           43  flow straightening member 
           44  support member 
           45  protruding portion 
           46  recessed portion 
           47  suctioning pipe 
           48  suction pump 
           49  lifting unit 
           50  dry unit 
           60  gas flow generating unit 
           61  operation panel 
           70  gas flow generating unit 
           70   a  upper exhaust port 
           70   b  lower exhaust port 
           80  position determining member 
           81  suction port 
           82  first filter 
           83  second filter 
           84  fan section 
           85  intake pipe 
           86  vent pipe 
           87  exhaust pipe 
           88  circulation pipe 
           90  position determining member elevating mechanism