Abstract:
A capping fixture is adapted to be coupled to a droplet discharge device including a droplet discharge head aligned on a unit plate of a carriage. The capping fixture includes a base panel, a head cap portion and an elastic member. The head cap portion is disposed on the base panel at a position corresponding to the droplet discharge head to hermetically seal the droplet discharge head when the capping fixture is coupled to the carriage of the droplet discharge device. The elastic member elastically couples the head cap portion with the base panel so that the head cap portion is movable within a prescribed distance in a direction substantially perpendicular to the base panel.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to Japanese Patent Application No. 2007-257660 filed on Oct. 1, 2007. The entire disclosure of Japanese Patent Application No. 2007-257660 is hereby incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to a capping fixture for a droplet discharge head. 
         [0004]    2. Related Art 
         [0005]    An inkjet device, i.e., a droplet discharge device, for discharging a functional liquid in the form of droplets is commonly known as a device for forming a desired pattern on a substrate using a functional liquid. The droplet discharge device forms a pattern by arranging droplets of a functional liquid discharged from a droplet discharge head in arbitrary locations on a substrate while moving the substrate mounted on a stage and the droplet discharge head for discharging droplets of the functional liquid relative to each other in two dimensions. 
         [0006]    A droplet discharge device has recently become known in which a plurality of droplet discharge heads is mounted on a single carriage, and a plurality of carriages is furthermore provided. Such a droplet discharge device is used for large-screen color filter manufacturing and the like, and the drawing speed thereof is enhanced by discharging droplets at the same time from a plurality of carriages. 
         [0007]    In the droplet discharge head, the functional liquid is fed from a separately provided tank or the like, and the fed functional liquid is temporarily retained in an ink chamber (cavity) provided inside the droplet discharge head. The functional liquid retained in the ink chamber is discharged as droplets from numerous nozzle holes that are formed in a nozzle plate provided so as to face a stage. 
         [0008]    When the droplet discharge head is in standby, the functional liquid retained in the ink chamber may dry out. When the functional liquid dries, not only do the viscosity increase and the discharge quantity change, but the functional liquid may also harden and cause nozzle hole blockage, flight deflection during discharge, and other problems. 
         [0009]    A method for preventing drying of the functional liquid in the ink tank has therefore been proposed, in which a seal member referred to as a cap is automatically brought into contact with the nozzle plate of the droplet discharge head to prevent drying of the functional liquid (Japanese Laid-Open Patent Application No. 5-42676, for example). A proposal has also been made to connect a suction means to the cap and forcibly discharge the functional liquid of the ink tank (Japanese Laid-Open Patent Application No. 6-336018, for example). 
       SUMMARY 
       [0010]    However, when these methods are applied to the droplet discharge device described above, it is also necessary to provided caps for sealing the droplet discharge heads, raising and lowering means for automatically raising and lowering the caps, suction means for suctioning the functional liquid of the ink tank via the caps, and other components. The automatic capping device provided with these components has a large size, and the cost of the droplet discharge device is difficult to reduce. Unlike a droplet discharge device such as a home printer, the droplet discharge device described above is rarely stopped for long periods, and the opportunities for an automatic capping device to be used are extremely limited. 
         [0011]    The present invention was developed in order to overcome the abovementioned problems, and an object of the present invention is to provide a capping fixture for a droplet discharge device that can easily be attached and detached by hand, and that suppresses drying of the functional liquid inside the droplet discharge head. 
         [0012]    A capping fixture according to one aspect of the present invention is adapted to be coupled to a droplet discharge device including a droplet discharge head aligned on a unit plate of a carriage. The capping fixture includes a base panel, a head cap portion and an elastic member. The head cap portion is disposed on the base panel at a position corresponding to the droplet discharge head to hermetically seal the droplet discharge head when the capping fixture is coupled to the carriage of the droplet discharge device. The elastic member elastically couples the head cap portion with the base panel so that the head cap portion is movable within a prescribed distance in a direction substantially perpendicular to the base panel. 
         [0013]    In the capping fixture for a droplet discharge head according to the present invention, even when there are deviations in the height positions of the droplet discharge heads arranged in the unit plate, the elastic member that elastically supports the head caps can absorb the height position deviations, and all of the droplet discharge heads can be reliably sealed. Consequently, drying of the functional liquid can be suppressed in all of the droplet discharge heads arranged in the unit plate. 
         [0014]    The capping fixture may further include a connecting retention part configured and arranged to connect and retain the base panel to the carriage when the capping fixture is coupled to the carriage. 
         [0015]    According to this capping fixture for a droplet discharge head, providing the connecting retention means for connecting and retaining the base panel in relation to the carriage enables the capping fixture to be manually attached to and detached from the carriage. Consequently, there is no need to provide a large-sized capping device provided with an automatic raising and lowering device for raising and lowering the capping fixture, for example, and the manufacturing cost of the droplet discharge device can be reduced. 
         [0016]    The capping fixture may further include a positioning member configured and arranged to position the head cap portion with respect to the droplet discharge head when the capping fixture is coupled to the carriage. 
         [0017]    According to this capping fixture for a droplet discharge head, providing a positioning member for positioning the head caps with respect to the corresponding droplet discharge heads enables the head caps to be reliably brought into close contact with all of the droplet discharge heads arranged in the unit plate. Consequently, drying can be reliably suppressed in the droplet discharge heads. 
         [0018]    The capping fixture may further include a height adjusting member configured and arranged to adjust a gap between the unit plate of the carriage and the base panel when the capping fixture is coupled to the carriage, the height adjusting member having a contacting part that contacts the unit plate when the capping fixture is coupled to the carriage. 
         [0019]    According to this capping fixture for a droplet discharge head, providing the height adjusting means for adjusting the gap between the unit plate and the base panel makes it possible to adjust the gap between the head caps and the base panel when the capping fixture is attached to the carriage. Specifically, the elastic force created by the elastic member in the separation direction can be adjusted. Consequently, the close contact of the head caps with the corresponding droplet discharge heads can be adjusted. As a result, the droplet discharge heads can be more reliably sealed. 
         [0020]    The capping fixture may be arranged so that the contacting part includes a magnet. 
         [0021]    According to this capping fixture for a droplet discharge head, the contacting part for making contact with the unit plate is provided with a magnet; e.g., the unit plate is formed by a magnetic material, whereby the capping fixture can be easily retained in close contact with the unit plate. Consequently, the capping fixture can easily be attached to the unit plate by using the connecting retention means to fix the capping fixture after the capping fixture is retained in close contact by the contacting part (magnet). 
         [0022]    The capping fixture may further include a release lever configured and arranged to release the contacting part from the unit plate when the capping fixture is separated from the carriage. 
         [0023]    According to this capping fixture for a droplet discharge head, the contacting part (magnet) can easily be released from the unit plate by providing a release lever for releasing the contacting part (magnet) from the unit plate. As a result, the capping fixture can easily be removed from the carriage. 
         [0024]    The capping fixture may further include a holding member configured and arranged to hold a duct connection member connected to the carriage when the capping fixture is coupled to the carriage. 
         [0025]    According to this capping fixture for a droplet discharge head, the duct connection member can be fixed to the fixing member and conveyed during conveyance or at other times, for example, by providing the fixing member for fixing the duct connection member connected to the droplet discharge heads. Consequently, since the duct connection member does not impede conveyance, the carriage can easily be conveyed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    Referring now to the attached drawings which form a part of this original disclosure: 
           [0027]      FIG. 1  is a perspective view showing an overall structure of a droplet discharge device; 
           [0028]      FIG. 2  is a side elevational view showing the relationship between the carriage plates and the carriage; 
           [0029]      FIG. 3  is a perspective view showing the overall structure of the unit plate of the carriage on which the droplet discharge head is mounted as viewed from the nozzle plate side; 
           [0030]      FIG. 4  includes a pair of diagrams (a) and (b), wherein  FIG. 4(   a ) is a perspective view showing the droplet discharge head as viewed from the nozzle plate; and  FIG. 4(   b ) is a simplified sectional view showing the droplet discharge head; 
           [0031]      FIG. 5  is a perspective view showing the capping fixture attached to the carriage in the first embodiment; 
           [0032]      FIG. 6  is a perspective view showing the capping fixture in the first embodiment; 
           [0033]      FIG. 7  is a diagram showing the relationship between the head cap and the base panel; 
           [0034]      FIG. 8  is a perspective view showing the capping fixture attached to the carriage in the second embodiment; and 
           [0035]      FIG. 9  is a perspective view showing the capping fixture in the second embodiment. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     First Embodiment 
       [0036]    An embodiment of the pattern formation device in which the present invention is implemented will be described below according to the drawings. 
         [0037]      FIG. 1  shows the overall structure of the droplet discharge device  1  as the pattern formation device for forming red, green, and blue color filters on a glass substrate on which a black matrix is formed. In the droplet discharge device  1  as shown in  FIG. 1 , a base  2  that extends in the primary scanning direction (X-axis direction) is provided on a floor surface, a pair of X-axis guide rails  11  are laid on the upper surface  2   a  of the base in the primary scanning direction (X-axis direction), and an X-axis movement plate  12  is mounted on the pair of X-axis guide rails  11 . The X-axis movement plate  12  is mounted so as to be able to move in the primary scanning direction along the X-axis guide rails  11 . X-axis linear motors M 1  are provided to the pair of X-axis guide rails  11 , and the X-axis linear motors M 1  move the X-axis movement plate  12  mounted on the pair of X-axis guide rails  11  back and forth in the X-axis direction via an air slider (not shown). 
         [0038]    In  FIG. 1 , the primary scanning direction is the X-axis direction, the secondary scanning direction orthogonal to the primary scanning direction (X-axis direction) is the Y-axis direction, the direction (vertical direction) orthogonal to the X-axis direction and Y-axis direction is the Z-axis direction, and the direction of rotation about the Z-axis direction is the θ direction. 
         [0039]    A substrate stage  14  is provided on the upper surface of the X-axis movement plate  12 . The substrate stage  14  is a vacuum suction table, a color filter substrate (referred to as a CF substrate) W composed of a glass substrate is suction-fixed to the upper surface of the substrate stage, and the CF substrate W is conveyed. The substrate stage  14  is supported and fixed so as to be able to rotate in the θ direction with respect to the X-axis movement plate  12  by a stage rotation mechanism  16  indicated by a dashed line provided between the X-axis movement plate  12  and the substrate stage  14 . 
         [0040]    Consequently, the substrate stage  14  (CF substrate W) moves together with the X-axis movement plate  12  in the X-axis direction (primary scanning direction). The substrate stage  14  (CF substrate W) also rotates in the θ direction parallel to the plane (XY plane (horizontal plane)) of the X-axis movement plate  12 . 
         [0041]    A pair of Y-axis guide rails  18  are provided so as to straddle over the X-axis guide rails  11  in the Y-axis direction. Support columns  19   a  at one end of the pair of Y-axis guide rails  18  are provided upright on one side of the upper surface  2   a  of the base  2 , and support columns  19   b  at the other end are provided upright on the floor at a distance from the base  2 . The pair of Y-axis guide rails  18  are arranged parallel to each other across a prescribed interval in the X-axis direction. In the pair of Y-axis guide rails  18  extending parallel to each other in the Y-axis direction in the present embodiment, the position above the base  2  is the work area, and the position at a distance from the base  2  is the standby area. 
         [0042]    A plurality (six in the present embodiment) of carriage plates  21  is arranged so as to bridge the space between the pair of Y-axis guide rails  18 . The carriage plates  21  are mounted so as to be able to move in the secondary scanning direction (Y-axis direction) along the Y-axis guide rails  18 . The pair of Y-axis guide rails  18  are provided with Y-axis linear motors M 2 , and the Y-axis linear motors M 2  move each of the carriage plates  21  mounted on the pair of Y-axis guide rails  18  reciprocally in the Y-axis direction via an air slider (not shown). In other words, the carriage plates  21  move on the Y-axis guide rails  18  back and forth between the work area and the standby area. 
         [0043]    It should be noted that when the droplet discharge device  1  is at rest, the carriage plates  21  are guided to the standby area and are made to stand by in the standby area until the next activation of the droplet discharge device  1 . 
         [0044]    Functional-liquid feeding units  22  and head electrical installation units  23  are mounted on the upper surface of each carriage plate  21 . The functional-liquid feeding units  22  are supply circuit devices for storing a prescribed quantity of the functional liquid F (see  FIG. 4(   b )) and feeding the functional liquid F to droplet discharge heads  40  (see  FIGS. 4(   a ) and  4 ( b )). The head electrical installation units  23  are electrical circuit devices for feeding electric signals for driving the droplet discharge heads  40 . 
         [0045]    The functional liquid F referred to herein is red, green, and blue filter ink that is placed in the frames of the black matrix formed on the CF substrate W. The functional liquid F is arranged in the frames of the black matrix formed on the CF substrate W, and is then dried to form red, green, and blue filters. 
         [0046]    As shown in  FIG. 2 , a suspension mechanism  25  is provided in the center position of the lower surface of each carriage plate  21 , and a carriage  30  is attached to the lower end part of the suspension mechanism  25 . 
         [0047]    The suspension mechanism  25  has a suspension base plate  26 , a suspension rotation frame  27 , and a suspension support frame  28 . The suspension base plate  26  is connected and fixed in position at the center of the lower surface of the carriage plate  21 , and the suspension rotation frame  27  is connected to the lower end part thereof. The suspension support frame  28  is connected to and supported by the lower end part of the suspension rotation frame  27  so as to be able to rotate in the θ direction. The suspension rotation frame  27  has a θ-axis rotation motor (not shown), and the θ-axis rotation motor rotates the suspension support frame  28  in the θ direction with respect to the suspension base plate  26  (carriage plate  21 ). The carriage  30  is supported by and fixed to the suspension support frame  28 , and the carriage  30  hung from the suspension mechanism  25  is rotated in the θ direction. 
         [0048]    The carriage  30  has a substantially rectangular cuboid carriage frame  31 . Open parts are provided on both sides of the carriage frame  31  in the X-axis direction and the Y-axis direction (the open parts in the X-axis direction are shown in  FIG. 8 ), and the surrounding air can flow in and out with respect to the inside of the carriage frame  31 . A unit plate  34  is fixed by a screw or the like (not shown) to the lower end part of the carriage frame  31  of the substantially rectangular cuboid carriage  30 . Droplet discharge heads  40  are detachably attached to the unit plate  34  and fixed in precise positions. In the present embodiment, three droplet discharge heads  40  arranged along the X-axis direction are attached in two rows parallel to the Y-axis direction; i.e., a total of six droplet discharge heads  40  are attached, as shown in  FIG. 3 . Ducts, wiring, and the like are provided inside the carriage frame  31 , but are omitted from the drawings in order to reduce complexity. 
       Droplet Discharge Heads  40   
       [0049]    The droplet discharge heads  40  attached to the unit plate  34  will next be described with reference to  FIG. 4 ,  FIG. 4(   a ) is an external perspective view showing a droplet discharge head as viewed from the substrate stage  14 . The droplet discharge head  40  is provided with a liquid body introduction part  41  having two connecting pins  42 ; a head base plate  43  that continues to the side of the liquid body introduction part  41 ; a pump unit  44  that continues into the liquid body introduction part  41 ; and a nozzle plate  45  that continues into the pump unit  44 . 
         [0050]    A duct connecting member (see  FIG. 2 )  50  that is connected to the functional-liquid feeding units  22  is connected to the connecting pins  42  of the liquid body introduction part  41 . A pair of head connectors  43 A are mounted to the head base plate  43 , and a flexible flat cable (not shown) connected to the head electrical installation units  23  is connected to the head base plate  43  via the head connectors  43 A. 
         [0051]    A rectangular head body  40 A is formed by the pump unit  44  and the nozzle plate  45 . 
         [0052]    Two nozzle rows  47  composed of discharge nozzles  46  for discharging droplets Fb are formed in the nozzle formation face  45   a  of the nozzle plate  45 . The two nozzle rows  47  are arranged parallel to each other, and each of the nozzle rows  47  is composed of  180  (shown schematically in the drawing) discharge nozzles  46  aligned at an equal pitch. Specifically, the two nozzle rows  47  are arranged symmetrically about the center line of the nozzle formation face  45   a  of the head body  40 A. 
         [0053]      FIG. 4(   b ) shows the inside of the pump unit  44  of the droplet discharge head  40 , and above each of the discharge nozzles  46  is a cavity  52 , an oscillation plate  53 , and a piezoelectric element PZ. The cavities  52  are connected to a functional-liquid feeding unit  22  via the duct connecting member, and accommodate the functional liquid F (filter ink) from the same functional liquid feeding unit  22  and feed the filter ink to the discharge nozzles  46 . The oscillation plates  53  vibrate the regions opposite the cavities  52  in the Z direction, thereby expanding and contracting the volume of the cavities  52 , and a meniscus of each discharge nozzle  46  is thereby vibrated. When the piezoelectric elements PZ receive a signal having a prescribed drive waveform, the piezoelectric elements PZ contract and extend in the Z direction, thereby vibrating the regions of the oscillation plates  53  in the Z direction. When the oscillation plates  53  vibrate in the Z direction, a portion of the accommodated filter ink in the cavities  52  is discharged as a droplet Fb from a discharge nozzle  46 . 
         [0054]    A rectangular flange-shaped flange part  48  to receive the liquid body introduction part  41  is formed at the base of the pump unit  44 ; i.e., the base of the head body  40 A. The flange part  48  prevents unseating, and also acts as a connecting part that is connected and fixed to the unit plate  34  by a head fixing screw (not shown). A pair of screw holes (female screws)  49  for small screws that fix the droplet discharge head  40  to the unit plate  34  are formed in the flange part  48 . In other words, the head body  40 A is inserted through a through-hole (not shown) formed in a prescribed position of the unit plate  34 , and the droplet discharge head  40  is fixed to the unit plate  34  by the head fixing screw (not shown) that passes through the unit plate  34  and engages with a screw hole  49 . 
         [0055]    The X-axis, Y-axis, and Z-axis shown in  FIGS. 2 through 4  are the same as the X-axis, Y-axis, and Z-axis shown in  FIG. 1 . Specifically, in the state in which the unit plate  34  is attached to the droplet discharge device  1 , the nozzle rows  47  (see  FIG. 4 ) formed in the droplet discharge head  40  extend in the Y-axis direction. 
       Capping Fixture  60   
       [0056]    Following is a description of the capping fixture  60  for preventing drying of the droplet discharge heads  40  of the carriages  30  during standby when the droplet discharge device  1  is at rest, and all of the carriages  30  (carriage plates  21 ) are in standby in the standby area until being activated. 
         [0057]    As shown in  FIG. 5 , a capping fixture  60  is attached to each of the carriages  30 . 
         [0058]    The capping fixture  60  has a base panel  61 , and the base panel  61  is supported at a prescribed distance from the unit plate  34  to which the plurality of droplet discharge heads  40  fixed to the carriage  30  is attached. 
         [0059]      FIG. 6  is a perspective view showing the entire capping fixture  60  as viewed from above, and first through fourth positioning guide panels  62   a,    62   b,    62   c,    62   d  as positioning members are fixed to the upper surface  61   a  of the base panel  61  at the four corners thereof. A fifth positioning guide panel  62   e  is fixed to the upper surface  61   a  of the base panel  61  in the center on one side thereof in the X-axis direction. 
         [0060]    The first positioning guide panel  62   a  comes into contact with the first side surface S 1  (see  FIG. 3 ; same hereinafter) of the unit plate  34 , the second positioning guide panel  62   b  comes into contact with the second side surface S 2  of the unit plate  34 , the third positioning guide panel  62   c  comes into contact with the third side surface S 3  of the unit plate  34 , the fourth positioning guide panel  62   d  comes into contact with the fourth surface S 4  of the unit plate  34 , and the fifth positioning guide panel  62   e  comes into contact with the fifth side surface S 5  of the unit plate  34 . The base panel  61  is thereby positioned with respect to the X-axis direction and Y-axis direction of the unit plate  34 . 
         [0061]    Positioning guide pins  63  as positioning members are fixed to the upper surface  61   a  of the base panel  61  on both ends thereof in the X-axis direction. 
         [0062]    The positioning guide pins  63  are fitted in a pair of pin holes (not shown) provided to the unit plate  34 . The base panel  61  is thereby precisely positioned with respect to the X-axis direction and Y-axis direction of the unit plate  34 . 
         [0063]    Pairs of height adjusting members  64   a,    64   b,    64   c,    64   d  are also fixed to the upper surface  61   a  of the base panel  61  at both ends thereof in the X-axis direction. The height adjusting members  64   a,    64   b,    64   c,    64   d  have adjustment screws  65  as contacting parts, and the heads of the adjustment screws  65  come into contact with the unit plate  34 , whereby the base panel  61  is precisely positioned with respect to the Z-axis direction of the unit plate  34 . 
         [0064]    The heads of the adjustment screws  65  are composed of magnets, and when the base panel  61  is retained by the unit plate  34  while the position thereof is adjusted, the heads of the adjustment screws  65  are retained in close contact with the unit plate  34  by magnetic attraction. 
         [0065]    A release lever  66  for removing from the unit plate  34  the base panel  61  retained in close contact with the unit plate  34  by the magnetic attraction of the heads of the adjustment screws  65  is provided to the other side in the X-axis direction of the upper surface  61   a  of the base panel  61 . 
         [0066]    Furthermore, first and second clamp devices  77   a,    77   b  as connecting retention parts are fixed to both ends of the upper surface  61   a  of the base panel  61  in the X-axis direction. 
         [0067]    The first clamp device  77   a  is connected so as to clamp the sixth side surface S 6  (see  FIG. 3 ; same hereinafter) of the unit plate  34 , and the second clamp device  77   b  is connected so as to clamp the seventh side surface S 7  of the unit plate  34 , so that the base panel  61  does not separate from the unit plate  34  (see  FIG. 5 ; the second clamp device  77   b  is not shown). 
         [0068]    Consequently, when the base panel  61  is mounted to the lower side of the unit plate  34 , the base panel  61  is guided by the first through fifth positioning guide panels  62   a  through  62   e  and the positioning guide pins  63 , and the X-axis direction and Y-axis direction thereof are positioned, and the base panel  61  is positioned by the height adjusting members  64   a  through  64   d  with respect to the Z-axis direction, and connected to and retained on the unit plate  34  by the magnetic attraction of the adjustment screws  65 . The base panel  61  is securely connected to and retained on the unit plate  34  by the first and second clamp devices  77   a,    77   b.    
         [0069]    In the base panel  61  as shown in  FIG. 6 , head caps  68  (head cap portions) whose number (six in the present embodiment) corresponds to the droplet discharge heads  40  provided to the unit plate  34  are positioned so as to correspond to the droplet discharge heads  40 . 
         [0070]    In each head cap  68 , a cap body  69  is placed in a concave part  61   b  formed on the upper surface  61   a  in the base panel  61 , as shown in  FIG. 7 . Through holes  69   a  are formed at both sides in the Y-axis direction of the cap body  69 , and guide shafts  70  inserted from the lower surface  61   c  of the base panel  61  are passed through the through holes  69   a.  Retainer members  71  are attached to the distal ends of the guide shafts  70 , and the cap body  69  can move along the guide shafts  70  without coming off the guide shafts  70 . 
         [0071]    Coil springs SP as elastic members are provided to the guide shafts  70  between the cap body  69  and the base panel  61 . The cap body  69  (head cap  68 ) is therefore clamped and retained in a position (position of engagement with the retainer members  71 ) at a distance from the base panel  61  by the coil springs SP. When the cap body  69  (head cap  68 ) is pressed against the elastic force of the coil springs SP, the cap body  69  (head cap  68 ) moves toward the base panel  61 . 
         [0072]    A ring-shaped seal member  73  that is brought into close contact with the nozzle formation face  45   a  so as to enclose all of the discharge nozzles  46  of the droplet discharge head  40  is provided to the cap body  69  to hermetically seal the droplet discharge head  40 . A cap chamber  72  that is open at the top is formed by the cap body  69  and the seal member  73 . 
         [0073]    Consequently, when the base panel  61  is connected to and retained on the unit plate  34 , the head caps  68  provided to the base panel  61  are brought into close contact with the nozzle formation face  45   a  in a state in which the ring-shaped seal members  73  enclose all of the discharge nozzles  46  in the corresponding droplet discharge heads  40  provided to the unit plate  34 . As a result, defects such as blockage due to exposure to outside air and drying of the functional liquid F are eliminated in the droplet discharge heads  40  provided to the unit plate  34 . 
         [0074]    At this time, even when attachment error in the Z-axis direction occurs for each of the droplet discharge heads  40  provided to the unit plate  34 , the head caps  68  are clamped and retained by the guide shafts  70  and the coil springs SP so as to be able to move in the Z-axis direction, and are therefore reliably brought into close contact with the corresponding droplet discharge heads  40 . 
         [0075]    Such effects as the following can be obtained through the embodiment described above. 
         [0076]    (1) According to the embodiment described above, the head caps  68  of the capping fixture  60  can move along the guide shafts  70 , and are elastically retained in the direction of separation from the base panel  61  by the coil springs SP. Consequently, even when there are height deviations from the unit plate  34  of the droplet discharge heads  40  attached to the carriages  30 , the seal member  73  can be reliably brought into close contact with the nozzle formation face  45   a  by the elastic force of the coil springs SP. Specifically, the droplet discharge heads  40  of the carriage  30  can be reliably sealed. As a result, drying of the functional liquid F in the droplet discharge heads  40  can be suppressed. 
         [0077]    (2) According to the embodiment described above, the first through fifth positioning guide panels  62   a  through  62   e  and the positioning guide pins  63  are provided for adjusting the position of the capping fixture  60  with respect to the unit plate  34  when the capping fixture  60  is attached to the carriage  30 . Consequently, the position of the capping fixture  60  (head caps  68 ) with respect to the unit plate  34  (droplet discharge heads  40 ) can be adjusted, and the head caps  68  can be reliably brought into close contact with the droplet discharge heads  40 . As a result, the droplet discharge heads  40  can be reliably sealed. 
         [0078]    (3) According to the embodiment described above, the height adjusting members  64   a  through  64   d  for adjusting the space between the unit plate  34  and the base panel  61  are provided to the base panel  61  of the capping fixture  60 . The heads of the adjustment screws  65  of the height adjusting members  64   a  through  64   d  are also composed of magnets. Consequently, the sealing force of the head caps  68  with respect to the droplet discharge heads  40  can be increased by using the height adjusting members  64   a  through  64   d  to adjust the space between the unit plate  34  and the base panel  61 . As a result, the droplet discharge heads  40  can be more reliably sealed. 
         [0079]    The heads (magnets) of the adjustment screws  65  of the height adjusting members  64   a  through  64   d  are also brought into contact with the unit plate  34 , whereby the capping fixture  60  can easily be retained in close contact with the unit plate  34 . By operating the first and second clamp devices  77   a,    77   b  from this state, the capping fixture  60  can easily be attached to the carriage  30 . 
         [0080]    (4) According to the embodiment described above, a release lever  66  is provided for separating the heads (magnets) of the adjustment screws  65  of the height adjusting members  64   a  through  64   d  from the unit plate  34  when the capping fixture  60  is retained in close contact with the unit plate  34  by the heads (magnets) of the adjustment screws  65  of the height adjusting members  64   a  through  64   d.    
         [0081]    Consequently, when the heads (magnets) of the adjustment screws  65  of the height adjusting members  64   a  through  64   d  are in contact with the unit plate  34 , the capping fixture  60  can easily be removed from the unit plate  34  by operating the release lever  66 . 
         [0082]    (5) According to the embodiment described above, first and second clamp devices  77   a,    77   b  are provided for connecting and fixing the capping fixture  60  to the carriage  30 . Consequently, the capping fixture  60  can easily be manually connected and fixed to the carriage  30 . As a result, since the droplet discharge heads  40  can be sealed, and drying of the functional liquid F can be suppressed without providing a large-sized capping device having, for example, a raising and lowering means, the cost of the droplet discharge device  1  can be reduced. 
       Second Embodiment 
       [0083]    A second embodiment of the present invention will next be described according to  FIGS. 8 and 9 . 
         [0084]    As shown in  FIG. 8 , the capping fixture  80  of the present embodiment is a capping fixture for preventing drying of the droplet discharge heads  40 , and is attached to the carriage  30  when the carriage  30  removed from the carriage plate  21  (suspension support frame  28 ) is transported. The same reference symbols are used to refer to elements that are the same as in the first embodiment, and no description thereof will be given. 
         [0085]    As shown in  FIG. 9 , the capping fixture  80  has a base panel  81 , and the base panel  81  is fixed to the carriage  30  and retained at a prescribed distance with respect to the unit plate  34  to which the plurality of droplet discharge heads  40  is attached. The external shape of the base panel  81  is similar to that of the unit plate  34 , albeit slightly larger. 
         [0086]    First through fourth positioning guides  82   a,    82   b,    82   c,    82   d  as positioning members in two groups are fixed to the four corners of the upper surface  81   a  of the base panel  81 . 
         [0087]    The first through fourth positioning guides  82   a,    82   b,    82   c,    82   d  hold the four corners of the unit plate  34 , whereby the base panel  81  is positioned with respect to the X-axis direction and Y-axis direction of the unit plate  34 . 
         [0088]    Furthermore, height adjusting members  84   a,    84   b,    84   c,    84   d,    84   e,    84   f  are fixed to both ends of the upper surface  81   a  of the base panel  81  in the X-axis direction. The height adjusting members  84   a  through  84   f  have adjustment screws  85  as contacting parts, and the heads of the adjustment screws  85  come into contact with the unit plate  34 , whereby the base panel  81  is precisely positioned with respect to the Z-axis direction of the unit plate  34 . 
         [0089]    The heads of the adjustment screws  85  are composed of magnets, and when the base panel  81  is retained by the unit plate  34  while the position thereof is adjusted, the heads of the adjustment screws  85  are retained in close contact with the unit plate  34  by magnetic attraction. 
         [0090]    Furthermore, first and second clamp devices  87   a,    87   b  as connecting retention parts are fixed to both ends of the upper surface  81   a  of the base panel  81  in the X-axis direction. The first and second clamp devices  87   a,    87   b  are connected so as to clamp the lower edges  32  of the sides of a carriage frame  31  in the X-axis direction as shown in  FIG. 8 , and so that the base panel  81  does not separate from the carriage  30  (unit plate  34 ). 
         [0091]    Consequently, when the base panel  81  is mounted to the lower side of the unit plate  34 , the X-axis direction and Y-axis direction thereof are positioned by the first through fourth positioning guides  82   a,    82   b,    82   c,    82   d,  and the base panel  81  is positioned by the height adjusting members  84   a  through  84   f  with respect to the Z-axis direction, and is connected to and retained on the unit plate  34  by the magnetic attraction of the adjustment screws  85 . The base panel  81  is securely connected to and retained on the unit plate  34  by the first and second clamp devices  87   a,    87   b.    
         [0092]    As shown in  FIG. 9 , the base panel  81  is also provided with head caps  68  having the same structure as in the first embodiment. 
         [0093]    Consequently, when the base panel  81  is connected to and retained on the unit plate  34 , the head caps  68  provided to the base panel  81  are brought into close contact with the nozzle formation face  45   a  in a state in which the ring-shaped seal members  73  enclose all of the discharge nozzles  46  in the corresponding droplet discharge heads  40  provided to the unit plate  34 . As a result, defects such as blockage due to exposure to outside air and drying of the functional liquid F are eliminated in the droplet discharge heads  40  provided to the unit plate  34 . 
         [0094]    At this time, even when attachment error in the Z-axis direction occurs for each of the droplet discharge heads  40  provided to the unit plate  34 , the head caps  68  are clamped and retained by the guide shafts  70  and the coil springs SP so as to be able to move in the Z-axis direction, and are therefore reliably brought into close contact with the corresponding droplet discharge heads  40 . 
         [0095]    Furthermore, tube fixing panels  88  as holding members that are folded in an L-shape are fixed to both ends of the upper surface  81   a  of the base panel  81  in the X-axis direction. As shown in  FIG. 8 , the tube fixing panels  88  fix together the duct connecting member  50  (see  FIG. 2 ) for feeding the functional liquid F to the droplet discharge heads  40  from the functional-liquid feeding units  22  when the capping fixture  80  is connected to and retained on the carriage  30 . 
         [0096]    According to the embodiment described above, such effects as those described below can be obtained in addition to the effects described in (1) through (5) of the first embodiment. 
         [0097]    (6) According to the embodiment described above, the tube fixing panels  88  for fixing together the duct connecting member  50  are provided to the capping fixture  80 , whereby the duct connecting member  50  can be fixed when the carriage  30  is transported. Consequently, the carriage  30  can easily be transported. 
         [0098]    The embodiments described above may be modified as described below. 
         [0099]    In the first and second embodiments described above, the capping fixtures  60 ,  80  are connected to and retained on the carriage  30  through the use of the first and second clamp devices  77   a,    77   b  and the first and second clamp devices  87   a,    87   b.  This configuration is not limiting, and the capping fixtures  60 ,  80  may be connected to and retained on the carriage  30  using screws or the like. 
         [0100]    In the first and second embodiments described above, the elastic members are coil springs SP. This configuration is not limiting, and leaf springs or the like, for example, may also be used. 
         [0101]    In the first and second embodiments described above, a carriage  30  is described that has six droplet discharge heads  40  mounted therein. This configuration is not limiting, and the arrangement and number of droplet discharge heads mounted in the carriage may be appropriately changed. 
         [0102]    In the first and second embodiments described above, a droplet discharge device is described for discharging droplets of a filter ink and forming a color filter on a CF substrate. This configuration is not limiting, and the present invention may be applied to a droplet discharge device for forming metal wiring, a droplet discharge device for forming an insulation layer, a droplet discharge device for forming a liquid crystal layer or an alignment film, a droplet discharge device for forming a luminescent layer of an organic EL display device, or the like. 
       General Interpretation of Terms 
       [0103]    In understanding the scope of the present invention, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts. Finally, terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies. 
         [0104]    While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.