Patent Document

CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority under 35 USC 119 from Japanese Patent Application No. 2008-252201 filed on Sep. 30, 2008, the disclosure of which is incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to a droplet ejecting device that forms an image on a recording medium by ejecting droplets toward the recording medium. 
         [0004]    2. Related Art 
         [0005]    Inkjet recording devices (droplet ejecting devices), that eject ink drops out from nozzles of an inkjet recording head (droplet ejecting head) and record an image on a recording sheet, are conventionally known. In order to keep the state of ejecting ink from the nozzles of the inkjet recording head good, the inkjet recording device is provided with a cleaning mechanism that wipes-off contaminating substances such as remaining ink (ink of increased viscosity), foreign matter (paper dust) and the like adhering to the nozzle surface. 
         [0006]    Japanese Patent Application Laid-Open (JP-A) No. 2004-195908, for example, discloses a cleaning mechanism that supplies cleaning liquid to a wiping sheet, pushes the wiping sheet containing the cleaning liquid against the nozzle surface of an inkjet recording head, and wipes-off the contaminating substances of the nozzle surface. 
       SUMMARY OF THE INVENTION 
       [0007]    However, in the technique disclosed in JP-A No. 2004-195908, because the applying and the wiping-off of the cleaning liquid are carried out simultaneously, it is difficult to cause the interface separating function of the cleaning liquid to be exhibited. 
         [0008]    In view of the aforementioned, the present invention provides a droplet ejecting device that, at the time of cleaning a nozzle surface, can cause the interface separating function of a cleaning liquid to be exhibited. 
         [0009]    A droplet ejecting device of a first aspect of the present invention includes: a droplet ejecting head having a nozzle surface at which plural nozzles that eject droplets are formed; an applying member applying a cleaning liquid to the nozzle surface; a wiping member disposed so as to be spaced apart from the applying member, and moving relative to the nozzle surface while contacting the nozzle surface, and wiping-off the cleaning liquid applied to the nozzle surface; and a unit for moving that moves both, the droplet ejecting head, and the applying member and the wiping member, relative to one another. 
         [0010]    In the droplet ejecting device of the first aspect, the droplet ejecting head is moved relative to the applying member and the wiping member by the unit for movement. The applying member and the wiping member are disposed so as to be apart from one another. Accordingly, at the time of cleaning the nozzle surface, the cleaning liquid is applied to the nozzle surface by the applying member, and thereafter, the cleaning liquid can be wiped-off from the nozzle surface by the wiping member. By carrying out applying and wiping of the cleaning liquid separately in this way, as compared with a case in which the applying and wiping of the cleaning liquid are carried out simultaneously, the cleaning liquid can be made to stay adhered to the nozzle surface for a long time, and the interface separating function of the cleaning liquid can be exhibited. 
         [0011]    In a droplet ejecting device of a second aspect, the applying member applies the cleaning liquid without contacting the nozzle surface. 
         [0012]    By applying the cleaning liquid without contacting the nozzle surface in this way, damage to the nozzle surface can be prevented. 
         [0013]    In a droplet ejecting device of a third aspect, the applying member is structured to include an applying roller having a rotating shaft that is disposed in a direction orthogonal to a direction of relative movement of the droplet ejecting head. 
         [0014]    By using an applying roller of such a structure, the cleaning liquid can be applied to the nozzle surface either by contact or without contact. 
         [0015]    In a droplet ejecting device of a fifth aspect, at a time of application of the cleaning liquid, the applying roller rotates in a forward direction with respect to the direction of relative movement of the droplet ejecting head. 
         [0016]    By making the rotating direction of the applying roller be the forward direction with respect to the direction of relative movement of the droplet ejecting head in this way, there is little friction with the nozzle surface, and damage to the nozzle surface can be prevented. Further, by making the rotating direction of the applying roller be the forward direction with respect to the direction of relative movement of the droplet ejecting head as described above, as compared with a case in which the applying roller is rotated in the reverse direction, there is little effect of the flow of the cleaning liquid on the meniscuses of the nozzles. Accordingly, the cleaning liquid can be applied to the nozzle surface without destroying the meniscuses, and poor ejecting due to the application of the cleaning liquid can be suppressed. 
         [0017]    A droplet ejecting device of a seventh aspect further includes a waste liquid tray disposed at a position facing the nozzle surface, wherein the applying member is disposed at a side nearer to the waste liquid tray than to the wiping member. 
         [0018]    Because the cleaning liquid may drip down from the nozzle surface to which the cleaning liquid has been applied by the applying member, it is not preferable for the nozzle surface to be located at the image forming position after application of the cleaning liquid by the applying member and before the wiping-off thereof. Thus, it is preferable to dispose the applying member at the side near to the waste liquid tray in this way. 
         [0019]    In a droplet ejecting device of an eighth aspect, the unit for moving relatively moves the droplet ejecting head from an applying member side toward a wiping member side, and application of the cleaning liquid by the applying member and wiping of the cleaning liquid by the wiping member are carried out by movement in one direction. 
         [0020]    Due to such a structure, the applying and the wiping of the cleaning liquid can be carried out efficiently by movement of the recording head in one direction. 
         [0021]    A droplet ejecting device of a ninth aspect further includes a unit for separating that moves the wiping member in a direction of moving away from the droplet ejecting head. 
         [0022]    By providing such a unit for separation, after the cleaning liquid is applied by the applying member, the droplet ejecting head can be made to not contact the wiping member, and the cleaning liquid can adhere to the nozzle surface for a long time. 
         [0023]    Because of the above structure, the present invention can cause the interface separating function of a cleaning liquid to be exhibited at the time of cleaning a nozzle surface. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    An exemplary embodiment of the present invention will be described in detail based on the following figures, wherein: 
           [0025]      FIG. 1  is an overall structural drawing showing the structure of an inkjet recording device relating to an exemplary embodiment; 
           [0026]      FIG. 2  is a perspective view showing a state in which a head unit is disposed at an image forming section relating to the present exemplary embodiment; 
           [0027]      FIG. 3  is a perspective view showing a state in which the head unit is disposed at a maintenance section relating to the present exemplary embodiment; 
           [0028]      FIG. 4  is a perspective view showing a state in which the head unit is disposed at the image forming section relating to the present exemplary embodiment, and is withdrawn upward; 
           [0029]      FIG. 5  is a schematic drawing showing the image forming section and the maintenance section relating to the present exemplary embodiment; 
           [0030]      FIG. 6A  through  FIG. 6D  are drawings explaining operations at the time of cleaning a nozzle surface in the present exemplary embodiment; 
           [0031]      FIG. 7A  through  FIG. 7D  are drawings explaining other operations at the time of cleaning the nozzle surface in the present exemplary embodiment; 
           [0032]      FIG. 8  is a schematic structural drawing showing a modified example of the inkjet recording device relating to the present exemplary embodiment; and 
           [0033]      FIG. 9  is a schematic structural drawing showing another modified example of the inkjet recording device relating to the present exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    An inkjet recording device that is related to an exemplary embodiment of the present invention is described hereinafter. 
         [0035]    First, the overall structure of an inkjet recording device  10  will be described. 
         [0036]    (Inkjet Recording Device) 
         [0037]    As shown in  FIG. 1 , a feeding/conveying section  12  that feeds and conveys sheets is provided at the image forming device  10  relating to the present exemplary embodiment, at the upstream side in the conveying direction of sheets that serve as recording media. Provided along the sheet conveying direction at the downstream side of the feeding/conveying section  12  are: a processing liquid coating section  14  that coats a processing liquid on a recording surface of the sheet, an image forming section  16  that forms an image on the recording surface of the sheet, an ink drying section  18  that dries the image formed on the recording surface, an image fixing section  20  that fixes the dried image to the sheet, and a discharging section  21  that discharges the sheet on which the image is fixed. Further, a maintenance section  80  (see  FIG. 2 ) is provided adjacent to the image forming section  16 . 
         [0038]    The respective processing sections will be described hereinafter. 
         [0039]    (Feeding/Conveying Section) 
         [0040]    A stacking section  22  in which sheets are stacked is provided at the feeding/conveying section  12 . A sheet feed portion  24 , that feeds one-by-one the sheets that are stacked in the stacking section  22 , is provided at the downstream side in the sheet conveying direction of the stacking section  22  (there are cases hereinafter in which “in the sheet conveying direction” is omitted) of the stacking section  22 . The sheet that is fed by the sheet feed portion  24  is conveyed to the processing liquid coating section  14  via a conveying portion  28  that is structured by plural roller pairs  26 . 
         [0041]    (Processing Liquid Coating Section) 
         [0042]    A processing liquid coating drum  30  is disposed rotatably in the processing liquid coating section  14 . Holding members  32 , that nip the leading end portions of sheets and hold the sheets, are provided at the processing liquid coating drum  30 . In the state in which a sheet is held at the surface of the processing liquid coating drum  30  via the holding member  32 , the sheet is conveyed to the downstream side by the rotation of the processing liquid coating drum  30 . 
         [0043]    In the same way as at the processing liquid coating drum  30 , the holding members  32  are provided as well at intermediate conveying drums  34 , an image forming drum  36 , an ink drying drum  38  and a fixing drum  40  that will be described later. Further, the transfer of a sheet from an upstream side drum to a downstream side drum is carried out by the holding members  32 . 
         [0044]    A processing liquid coating device  42  and a processing liquid drying device  44  are disposed along the peripheral direction of the processing liquid coating drum  30  at the upper portion of the processing liquid coating drum  30 . Processing liquid is coated onto the recording surface of the sheet by the processing liquid coating device  42 , and the processing liquid is dried by the processing liquid drying device  44 . 
         [0045]    The processing liquid reacts with ink, aggregates the color material (pigment), and has the effect of promoting separation of the color material (pigment) and the solvent. A storing portion  46 , in which the processing liquid is stored, is provided at the processing liquid coating device  42 , and a portion of a gravure roller  48  is soaked in the processing liquid. 
         [0046]    A rubber roller  50  is disposed so as to press-contact the gravure roller  48 . The rubber roller  50  contacts the recording surface (obverse) side of the sheet such that the processing liquid is coated thereon. Further, a squeegee (not shown) contacts the gravure roller  48  and controls the processing liquid coating amount that is coated on the recording surface of the sheet. 
         [0047]    It is ideal that the film thickness of the processing liquid is sufficiently smaller than the droplet ejected by the head. For example, in a case in which the ejected droplet amount is 2 pl, the average diameter of the droplet ejected by the head is 15.6 μm. If the film thickness of the processing liquid is thick, the ink dot floats within the processing liquid without contacting the recording surface of the sheet. It is preferable to make the film thickness of the processing liquid be less than or equal to 3 μm in order to obtain a landed dot diameter of greater than or equal to 30 μm at an ejected droplet amount of 2 pl. 
         [0048]    On the other hand, at the processing liquid drying device  44 , a hot air nozzle  54  and an infrared heater  56  (hereinafter called “IR heater  56 ”) are disposed near to the surface of the processing liquid coating drum  30 . The solvent such as water or the like within the processing liquid is vaporized by the hot air nozzle  54  and the IR heater  56 , and a solid or thin-film processing liquid layer is formed on the recording surface side of the sheet. By making the processing liquid be a thin layer in the processing liquid drying process, the dots of ink that are ejected at the image forming section  16  contact the sheet surface such that the necessary dot diameter is obtained, and the actions of reacting with the thin-layer processing liquid, aggregating the pigment, and fixing to the sheet surface are easily obtained. 
         [0049]    The sheet, on whose recording surface the processing liquid has been coated and dried at the processing liquid coating section  14  in this way, is conveyed to an intermediate conveying section  58  that is provided between the processing liquid coating section  14  and the image forming section  16 . 
         [0050]    (Intermediate Conveying Section) 
         [0051]    The intermediate conveying drum  34  is provided rotatably in the intermediate conveying section  58 . A sheet is held at the surface of the intermediate conveying drum  34  via the holding member  32  provided at the intermediate conveying drum  34 , and the sheet is conveyed to the downstream side by the rotation of the intermediate conveying drum  34 . 
         [0052]    (Image Forming Section) 
         [0053]    The image forming drum  36  (that will be described later) is provided rotatably in the image forming section  16 . A sheet is held at the surface of the image forming drum  36  via the holding member  32  provided at the image forming drum  36 , and the sheet is conveyed to the downstream side by the rotation of the image forming drum  36 . 
         [0054]    A head unit  66  is disposed at the upper portion of the image forming drum  36  so as to contact the surface of the image forming drum  36 . The head unit  66  is structured so as to include single-pass-type inkjet line heads  64 , and a head housing  65  that houses the inkjet line heads  64 . At the head unit  66 , the inkjet line heads  64  of at least YMCK that are basic colors are arrayed along the peripheral direction of the image forming drum  36 , and form images of the respective colors on the processing liquid layer that was formed on the recording surface of the sheet at the processing liquid coating section  14 . Image formation is carried out by ejecting ink from nozzles (not shown) of the inkjet line heads  64  on the basis of image data. 
         [0055]    The processing liquid has the effect of making the color material (pigment) and the latex particles that are dispersed within the ink aggregate in the processing liquid, and forms aggregates at which flowing of the color material and the like do not arise on the sheet. As an example of the reaction between the ink and the processing liquid, an acid is contained within the processing liquid, and by lowering the pH, pigment dispersion is destroyed, and by using an aggregating mechanism, running of the color material, color mixing between the inks of the respective colors, and ejected droplet interference due to uniting of liquids at the time when the ink drops land are avoided. 
         [0056]    The inkjet line heads  64  carry out ejecting of droplets synchronously with an encoder (not illustrated) that is disposed at the image forming drum  36  and detects the rotating speed. Due thereto, the landing positions of the droplets are determined highly accurately, and non-uniform droplet ejection can be reduced independently of deviations of the image forming drum  36 , the precision of a rotating shaft  68 , or the surface speed of the drum. 
         [0057]    As shown in  FIG. 2 , the head unit  66  is mounted to a ball screw  67  that is disposed parallel to the rotating shaft  68  of the image forming drum  36 . A guide shaft  67 G is disposed beneath the ball screw  67 , parallel to the ball screw  67 . A guide rail  69  is provided beneath the head unit  66 . The guide rail  69  is disposed parallel to the ball screw  67 . Guide grooves  69 A, that are engaged by engaging portions (not shown) that project-out from the bottom surface of the head housing  65 , are formed in the guide rail  69 . The head unit  66  can move along the guide grooves  69 A. 
         [0058]    The ball screw  67 , the guide shaft  67 G and the guide rail  69  extend from an image forming position P 1  above the image forming drum  36 , to a maintenance position P 2  (see  FIG. 3 ) that is for carrying out maintenance of the inkjet line heads  64 . The ball screw  67  is rotated by a driving motor  66 M, and due to this rotation, the head unit  66  is moved between the image forming position P 1  and the maintenance position P 2 . Further, as shown in  FIG. 4 , the head unit  66  can be withdrawn from above the image forming drum  36 . 
         [0059]    Maintenance operations, such as cleaning the nozzle surfaces  63  of the inkjet line heads  64 , expelling ink of increased viscosity, and the like, are carried out at the maintenance section  80  that will be described later. 
         [0060]    Due to the rotation of the image forming drum  36 , the sheet, on whose recording surface an image is formed, is conveyed to an intermediate conveying section  70  that is provided between the image forming section  16  and the ink drying section  18 . However, because the structure of the intermediate conveying section  70  is substantially the same as that of the intermediate conveying section  58 , description thereof is omitted. 
         [0061]    (Maintenance Section) 
         [0062]    As shown in  FIG. 2  and  FIG. 5 , the maintenance section  80  is disposed adjacent to the image forming section  16  along the axial direction of the image forming drum  36 . A wiping unit  90 , an application unit  88 , and a nozzle cap  81  are disposed at the maintenance section  80  so as to be lined-up in that order from the side near the image forming drum  36 . 
         [0063]    The nozzle cap  81  is a cap for covering the nozzle surfaces  63  of the inkjet line heads  64 , and is used at times of making the outer sides of the nozzle surfaces  63  negative pressure so as to suck ink of increased viscosity from the nozzles, and carrying out dummy ejecting that ejects ink out from the nozzles for maintenance rather than printing. A waste liquid tray  82  is provided beneath the nozzle cap  81 . A feed-out path  83 , for feeding waste liquid out to an unillustrated waste liquid ink tank, is connected to the floor portion of the waste liquid tray  82 . 
         [0064]    The application unit  88  is structured to include a applying roller  86  and a cleaning liquid tray  87 . Cleaning liquid  89  is pooled in the cleaning liquid tray  87 . A cleaning liquid containing a solvent such as DEGmBE (diethylene glycol monobutyl ether) or the like can be used as the cleaning liquid  89 . Cleaning liquid is supplied to the cleaning liquid tray  87  from a cleaning liquid tank  84  via a supply path  85 . While the cleaning operation is being repeated, ink and the like become mixed-in with the cleaning liquid  89  and the concentration thereof changes. Therefore, it is preferable to periodically replace the cleaning liquid  89 , or to sense changes in the reflected light (transmitted light) from the cleaning liquid  89  by using a photosensor or the like and replace the cleaning liquid  89 , so as to maintain the cleaning ability. 
         [0065]    A rotating shaft  86 A of the applying roller  86  is disposed in a direction orthogonal to the rotating shaft  68  of the image forming drum  36 , and the applying roller  86  can rotate around the rotating shaft  86 A. The outer surface of the applying roller  86  is arc-shaped also in the axial direction, so as to run along the nozzle surfaces  63  of the plural (four in the present exemplary embodiment) inkjet line heads  64  that are lined-up. The lower side of the applying roller  86  is immersed in the cleaning liquid  89  that is pooled in the cleaning liquid tray  87 . By rotating, the applying roller  86  draws-up the cleaning liquid  89  such that a cleaning liquid film can be formed on the outer surface of the applying roller  86 . A rubber roller of silicon, urethane, EPDM or the like, a plastic roller of POM or the like, or a metal roller of SUS or the like can be used as the applying roller  86 . In particular, a silicon roller or a POM roller can be suitably used. The direction of rotation of the applying roller  86  is the same direction (the forward direction) as the direction of movement of the head unit  66  at the time of cleaning 
         [0066]    The application of the cleaning liquid  89  to the nozzle surfaces  63  is carried out by causing the head unit  66  to pass by the upper side of the applying roller  86 . At this time, the applying roller  86  does not contact the nozzle surfaces  63  of the inkjet line heads  64 . Only the drawn-up cleaning liquid  89  contacts the nozzle surfaces  63 , and the cleaning liquid  89  is applied onto the nozzle surfaces  63 . 
         [0067]    At the wiping unit  90 , a wiping sheet  91  is made to contact the nozzle surfaces  63  of the inkjet line heads  64 , and wipes-off the cleaning liquid  89  that was applied to the nozzle surfaces  63 . The wiping unit  90  is disposed so as to be separated from the application unit  88 . A cloth of polyester or polypropylene that has indentations and recesses on the surface thereof can be used as the wiping sheet  91 . The wiping unit  90  has a draw-out portion  92 , a wiping roller portion  93 , a take-up portion  94 , a housing  95  and a vertical movement mechanism  96 . The wiping sheet  91 , that has not yet been used and is in a roll form, is disposed at the draw-out portion  92 . The wiping sheet  91  that is drawn-out from the draw-out portion  92  is conveyed by conveying rollers  97 , is trained around the wiping roller portion  93 , and is taken-up at the take-up portion  94 . At the wiping roller portion  93 , the wiping sheet  91  is pushed against the nozzle surfaces  63 . The drawing-out direction of the wiping sheet  91  is the direction opposite to the direction of movement of the head unit  66  at the time of cleaning The draw-out portion  92 , the wiping roller portion  93 , and the take-up portion  94  are housed within the housing  95 . 
         [0068]    The vertical movement mechanism  96  has a moving stand  96 A, and the housing  95  is disposed on the moving stand  96 A. The moving stand  96 A can be moved in the vertical direction by the vertical movement mechanism  96 . 
         [0069]    (Ink Drying Section) 
         [0070]    The ink drying drum  38  is provided rotatably in the ink drying section  18 . Plural hot air nozzles  72  and IR heaters  74  are disposed at the upper portion of the ink drying drum  38  so as to contact the surface of the ink drying section  18 . 
         [0071]    Here, as an example, the hot air nozzles  72  are disposed at the upstream side and the downstream side, and pairs of IR heaters  74  that are lined-up in parallel are disposed alternately with the hot air nozzles  72 . Other than this, numerous IR heaters  74  may be disposed at the upstream side and a large amount of thermal energy irradiated and the temperature of the moisture raised at the upstream side, whereas, at the downstream side, numerous hot air nozzles  72  may be disposed and the saturated water vapor blown-away. 
         [0072]    Here, the hot air nozzles  72  are disposed such that the angle at which the hot air is blown out is inclined toward the trailing end side of the sheet. Due thereto, the flow of hot air from the hot air nozzles  72  can be collected in one direction. Further, the sheet can be pushed against the ink drying drum  38  side, and the state in which the sheet is held at the surface of the ink drying drum  38  can be maintained. 
         [0073]    Due to the warm air from the hot air nozzles  72  and the IR heaters  74 , at the portion of the sheet where the image is formed, the solvent that is dispersed by the color material aggregating action is dried, and a thin-film image layer is formed. 
         [0074]    The warm air is usually set to 50° C. to 70° C., although it depends on the conveying speed of the sheet. By setting the temperature of the IR heater  74  to 200° C. to 600° C., the ink surface temperature is set so as to become 50° C. to 60° C. The evaporated solvent is discharged to the exterior of the image forming device  10  together with air, but the air is recovered. This air may be cooled by a cooler/radiator or the like, and recovered as liquid. 
         [0075]    Due to the rotation of the ink drying drum  38 , the sheet, on whose recording surface the image is dried, is conveyed to an intermediate conveying section  76  that is provided between the ink drying section  18  and the image fixing section  20 . Note that, because the structure of the intermediate conveying section  76  is substantially the same as that of the intermediate conveying section  58 , description thereof is omitted. 
         [0076]    (Image Fixing Section) 
         [0077]    The image fixing drum  40  is provided rotatably in the image fixing section  20 . The image fixing section  20  has the function of applying heat and pressure and fusing the latex particles within the image layer that is a thin layer formed on the ink drying drum  38 , and fixing them on the sheet. 
         [0078]    A heating roller  78  is disposed at the upper portion of the image fixing drum  40  so as to contact the surface of the image fixing drum  40 . At the heating roller  78 , a halogen lamp is built-in within a metal pipe of aluminum or the like that has good thermal conductivity, and thermal energy of greater than or equal to the Tg temperature of the latex is provided by the heating roller  78 . Due thereto, the latex particles fuse and push-in fixing into the indentations and protrusions on the sheet is carried out, and the unevenness of the surface of the image can be leveled and glossiness can be obtained. 
         [0079]    A fixing roller  80  is provided at the downstream side of the heating roller  78 . The fixing roller  80  is disposed in a state of press-contacting the surface of the image fixing drum  40 , and nipping force is obtained between the fixing roller  80  and the image fixing drum  40 . Therefore, at least one of the fixing roller  80  and the image fixing drum  40  has an elastic layer at the surface thereof, and has a uniform nip width with respect to the sheet. 
         [0080]    The sheet, on whose recording surface an image is fixed by the above-described processes, is conveyed by the rotation of the image fixing drum  40  toward the discharging section  21  side that is provided at the downstream side of the image fixing section  20 . 
         [0081]    Note that, although the image fixing section  20  is described in the present exemplary embodiment, it suffices to be able to, at the ink drying section  18 , dry and fix the image that is formed on the recording surface. Therefore, the image fixing section  20  is not absolutely necessary. 
         [0082]    Next, the cleaning of the nozzle surfaces  63  of the inkjet line heads  64  will be described. Note that the cleaning of the nozzle surfaces  63  may be carried out about the time of the maintenance process that is carried out by the application of pressure (suction), or may be carried out independently. 
         [0083]    First, the head unit  66  that is disposed at the image forming position P 1  is withdrawn upward so as to not contact the wiping unit  90  and the cleaning liquid of the application unit  88 , and is moved to the maintenance position P 2  (see  FIG. 6A ). 
         [0084]    Next, the head unit  66  is lowered such that the nozzle surfaces  63  can contact the wiping unit  90  and the cleaning liquid of the application unit  88 , and is moved toward the image forming position P 1  (the image forming section  16 ) (see  FIG. 6B ). At this time, the applying roller  86 , while rotating in the same direction as the direction of movement of the head unit  66 , draws-up the cleaning liquid  89  that is pooled in the cleaning liquid tray  87 , and forms a cleaning liquid film on the outer surface. Further, the draw-out portion  92  and the take-up portion  94  are driven so that the wiping sheet  91  moves in the direction opposite to the moving direction of the head unit  66 . 
         [0085]    While moving toward the image forming position Pl, the nozzle surfaces  63  of the inkjet line heads  64  reach the region above the applying roller  86 , and contact the cleaning liquid  89  on the surface of the applying roller  86 , and the cleaning liquid  89  is applied thereto. Then, the nozzle surfaces  63  move further in the state in which the cleaning liquid  89  is applied thereto. At this time, adhered matter B that adheres to the nozzle surfaces  63  is dissolved by the cleaning liquid  89 . Then, the nozzle surfaces  63  reach the region above the wiping roller portion  93 . At this position, the wiping sheet  91  is pressed against the nozzle surfaces  63 , and the adhered matter B that is dissolved by the cleaning liquid  89  is wiped-off by the wiping sheet  91  (see  FIG. 6C ). The application of the cleaning liquid  89  by the applying roller  86  and the wiping-off by the wiping sheet  91  are carried out in succession. The adhered matter B on the entire nozzle surfaces  63  is wiped-off, and the head unit  66  reaches the image forming position P 1  (see  FIG. 6D ). 
         [0086]    In the present exemplary embodiment, as described above, the application of and the wiping-off of the cleaning liquid  89  are carried out separately. Accordingly, after separating of the interface between the adhered matter B and the nozzle surfaces  63  is promoted by the cleaning liquid, wiping-off is carried out. Therefore, the adhered matter B can be removed effectively. 
         [0087]    Further, in cases in which the nozzle surfaces  63  are greatly dirtied, cleaning can be carried out as follows. 
         [0088]    First, the moving stand  96 A is lowered by the vertical movement mechanism  96  and the wiping unit  90  is withdrawn downward, so that the wiping sheet  91  does not contact the nozzle surfaces  63  (see  FIG. 7A ). Then, the head unit  66  is moved from the image forming position P 1  toward the maintenance position P 2  (see  FIG. 7B ). While moving toward the maintenance position P 2 , the nozzle surfaces  63  of the inkjet line heads  64  pass above the wiping unit  90  without contact, and reach the region above the applying roller  86 . The applying roller  86  is rotated in the same direction as the direction of movement of the head unit  66 , i.e., in the opposite direction of the above-described case of heading toward the image forming position P 1 . The cleaning liquid  89  on the surface, that has been drawn-up by the applying roller  86 , contacts the nozzle surfaces  63 , and the cleaning liquid  89  is applied thereto. Then, the head unit  66  moves further and reaches the maintenance position P 2  (see  FIG. 7C ). At this time, the nozzle surfaces  63  have not been wiped and are in a state in which the cleaning liquid  89  is applied thereto. Cleaning liquid may drip downward, but because the head unit  66  is above the waste liquid tray  82 , the cleaning liquid can be received in the waste liquid tray  82 . 
         [0089]    The head unit  66  is made to stand-by at the maintenance position P 2  for a predetermined soaking time period. Due thereto, the interface separating effect of the cleaning liquid  89  can be exhibited even more effectively. Thereafter, the wiping unit  90  is returned to the upper side (see  FIG. 7D ) so that the wiping sheet  91  can contact the nozzle surfaces  63 . Then, the head unit  66  is moved toward the image forming position Pl. At this time, the applying roller  86  is driven reversely so as to rotate in the same direction as the head unit  66 . The cleaning liquid  89  is again applied to the nozzle surfaces  63  at the time when they pass above the application unit  88 . The adhered matter B is, together with the cleaning liquid, wiped-off by the wiping sheet  91  of the wiping unit  90  (see  FIG. 6A  through  FIG. 6D ). 
         [0090]    Note that, although the applying roller  86  does not contact the nozzle surfaces  63  in the present exemplary embodiment, the cleaning liquid may be applied in a state in which the applying roller  86  is made to contact the nozzle surfaces  63 . In particular, by applying the cleaning liquid in a non-contact state as in the present exemplary embodiment, the load on the nozzle surfaces  63  can be mitigated. 
         [0091]    Further, in the present exemplary embodiment, the direction of rotation of the applying roller  86  is made to be the same direction as the direction of movement of the nozzle surfaces  63 , but the rotating direction of the applying roller  86  may be made to be the opposite direction. In particular, by making the rotating direction of the applying roller  86  be the same direction as the moving direction of the nozzle surfaces  63  as in the present exemplary embodiment, the load on the nozzle surfaces  63  can be further suppressed. Further, by making the rotating direction of the applying roller  86  be the forward direction with respect to the relative moving direction of the head unit  66  as described above, as compared with a case in which the applying roller  86  is rotated in the reverse direction, the flow of the cleaning liquid affects the meniscuses of the nozzles less. Accordingly, the cleaning liquid can be applied to the nozzle surfaces  63  without destroying the meniscuses, and poor ejecting due to application of the cleaning liquid can be suppressed. 
         [0092]    In the present exemplary embodiment, the application unit  88  is disposed at the side nearer to the maintenance position P 2  than the wiping unit  90  is, but such a positional relationship is not absolutely necessary. In particular, by arranging the units in the positional relationship of the present exemplary embodiment, after application of the cleaning liquid, the head unit  66  is disposed at the maintenance position P 2 . Therefore, when the cleaning liquid that has been applied to the nozzle surfaces  63  drips down, that cleaning liquid can be received by the nozzle cap for maintenance or the like. 
         [0093]    Further, the present exemplary embodiment describes an example of carrying out wiping of the nozzle surfaces  63  by the wiping sheet. However, as shown in  FIG. 8 , wiping can be carried out by moving a blade  99  relatively while causing the blade  99  to contact the nozzle surfaces  63 . 
         [0094]    Moreover, the present exemplary embodiment describes an example of applying the cleaning liquid by using the applying roller  86 , but, as shown in  FIG. 9 , the cleaning liquid may be blown onto the nozzle surfaces  63  by using a spraying member  101 . In this case, it is preferable that the cleaning liquid be blown-out from an oblique direction with respect to the nozzle surfaces  63 . 
         [0095]    Although the head unit  66  is moved in the present exemplary embodiment, the application unit  88  and the wiping unit  90  may be moved with respect to the head unit  66 . 
         [0096]    Further, the above exemplary embodiment describes the case of an inkjet recording device that ejects ink and forms an image on a sheet. However, the liquid that is ejected is not limited to ink. For example, the present invention can be applied to drying devices in general of various industrial applications, such as the formation of bumps for parts packaging by ejecting solder in a molten state onto a substrate, the formation of an EL display panel that is carried out by ejecting an organic EL solution onto a substrate, or the like. 
       EXAMPLE   
       [0097]    By using DEGmBE (diethylene glycol monobutyl ether) of a viscosity of 20 CP as the cleaning liquid of the inkjet recording device of the present exemplary embodiment, a cleaning liquid film of 0.5 mm was formed on an applying roller whose diameter was φ 40 mm and whose rotational speed was 600 rpm, and the cleaning liquid was applied to the nozzle surfaces with the moving speed of the head unit being 80 mm/sec. A Toraysee (manufactured by Toray Industries, Inc.) was used as the wiping sheet, and was moved at 1.5 mm/sec in the direction opposite the head unit, and wiped-off the nozzle surfaces. The time from the application of the cleaning liquid until the wiping-off of the cleaning liquid by the wiping sheet was approximately 2 seconds. During this time, the cleaning liquid penetrated into the interface between the adhered matter and the nozzle surfaces, interface separation occurred, and the adhered matter was wiped-off well.

Technology Category: 7