Patent Publication Number: US-11383540-B2

Title: Printing apparatus

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a printing apparatus. 
     2. Description of the Related Art 
     In the related art, a printing apparatus for printing on a workpiece having a curved surface by using an ink jet is known, for example, in Japanese Patent No. 6426038 (hereinafter referred to as “Patent Literature 1”). 
     Patent Literature 1 discloses a printing apparatus having a configuration in which an ink droplet is discharged by tilting a nozzle row in a sub scanning direction with respect to a side surface of a workpiece having a cylindrical shape body whose axial direction is a main scanning direction of an ink jet head. 
     However, the printing apparatus of Patent Literature 1 is limited to those in which the cross-sectional shape of the workpiece that can be printed is a cylindrical shape body. Therefore, there is a demand for a printing apparatus capable of printing with high accuracy even on a workpiece having any three-dimensional curved surface, not limited to a workpiece having a cylindrical shape body. 
     SUMMARY 
     The present disclosure provides a printing apparatus capable of printing a predetermined image with high accuracy by discharging droplets onto a workpiece having a three-dimensional curved surface according to the configuration indicated below. 
     That is, the printing apparatus of the present disclosure includes a printing unit that discharges ink onto a surface of the workpiece and a workpiece drive unit that adjusts a position of the workpiece. The printing unit includes a plurality of ink jet parts that discharge the ink and a main scanning linear motion mechanism that moves each of the plurality of ink jet parts in a same main scanning direction. 
     According to this configuration, the main scanning linear motion mechanism moves each of the plurality of ink jet parts in the same main scanning direction. That is, the main scanning linear motion mechanism moves each of the plurality of ink jet parts independently along the main scanning direction. As a result, for example, a printing apparatus capable of printing with a high degree of freedom can be obtained even on a workpiece having a recessed surface or a projection surface. 
     Further, the main scanning linear motion mechanism of the printing apparatus of the present disclosure moves the ink jet part involved in printing the workpiece among the plurality of ink jet parts so as to face the surface of the workpiece and moves one or more remaining ink jet parts among the plurality of ink jet parts to retreat from the surface of the workpiece. 
     According to this configuration, printing is performed with only the ink jet part involved in the printing facing the surface of the workpiece. On the other hand, the ink jet part that is not involved in the printing is configured to retreat from the workpiece so as not to interfere with the workpiece. As a result, the degree of freedom in a position adjustment motion of the workpiece can be increased. 
     Further, the printing unit of the printing apparatus of the present disclosure includes a sub scanning linear motion mechanism that moves at least one of the plurality of ink jet parts in a sub scanning direction intersecting with the main scanning direction. 
     According to this configuration, at least one of the plurality of ink jet parts is configured to be movable in the sub scanning direction. That is, only the ink jet part of the color that is a printing target is printed close to the workpiece. Therefore, interference between the workpiece and the ink jet part of other colors that are not the printing target can be prevented. As a result, the degree of freedom in a position adjustment motion of the workpiece can be increased. 
     Further, the printing unit of the printing apparatus of the present disclosure includes a forward and backward linear motion mechanism that moves at least one of the plurality of ink jet parts forward and backward with respect to the workpiece. 
     According to this configuration, the forward and backward linear motion mechanism moves at least one of the plurality of ink jet parts forward and backward with respect to the workpiece. That is, the forward and backward linear motion mechanism prints only the ink jet part of the color that is a printing target close to the workpiece. Therefore, interference between the workpiece and the ink jet part of other colors that are not the printing target can be prevented. As a result, the degree of freedom in a position adjustment motion of the workpiece can be increased. 
     Further, the printing unit of the printing apparatus of the present disclosure includes a rotation mechanism that rotates at least one of the plurality of ink jet parts. 
     According to this configuration, the ink jet part is configured to be rotatably by a rotation mechanism. As a result, a nozzle position of the ink jet part with respect to the workpiece can be finely adjusted by the rotation mechanism while moving the ink jet part in the main scanning direction. 
     Specifically, the rotation mechanism, for example, forms the plurality of nozzle rows arranged in a row along the sub scanning direction of the ink jet part in a position inclined obliquely with respect to the main scanning direction. Thereby, the pitch between the plurality of nozzles arranged in a row can be reduced. As a result, the print resolution of the printing apparatus can be increased. 
     Further, the rotation mechanism rotates, for example, the nozzle row of the ink jet part by 90° with respect to the main scanning direction. Thereby, the printing direction with respect to the workpiece can be changed. As a result, the accuracy of ink landing onto the workpiece can be improved. 
     Further, the workpiece drive unit of the printing apparatus of the present disclosure includes drive mechanisms of at least four axes, and at least two axes of the drive mechanisms of four axes are configured by a rotation mechanism. 
     According to this configuration, the workpiece drive unit includes the drive mechanisms of at least four axes, and at least two axes thereof are configured by a rotation mechanism. As a result, the adjustment range of the position of the workpiece can be widened. Therefore, the position adjustment according to the curved surface of the workpiece can be speeded up, and the workpiece can be printed with high accuracy. 
     Further, the main scanning linear motion mechanism of the printing apparatus of the present disclosure includes a first main scanning linear motion mechanism and a second main scanning linear motion mechanism arranged in parallel to each other. The plurality of ink jet parts are arranged in a row along the main scanning direction, and are alternately attached to the first main scanning linear motion mechanism and the second main scanning linear motion mechanism. 
     According to this configuration, the first main scanning linear motion mechanism and the second main scanning linear motion mechanism are arranged in parallel to each other. The plurality of ink jet parts are arranged in a row along the main scanning direction, and are alternately attached to the first main scanning linear motion mechanism and the second main scanning linear motion mechanism. Thereby, a gap between the ink jet part attached to the first main scanning linear motion mechanism and the ink jet part attached to the second main scanning linear motion mechanism can be set small. As a result, the entire length of the printing apparatus in the main scanning direction can be reduced. 
     According to the present disclosure, it is possible to provide a printing apparatus capable of printing accurately on a workpiece having a three-dimensional curved surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view illustrating a schematic configuration of a state in which a workpiece of a printing apparatus according to Exemplary Embodiment 1 is turned upward; 
         FIG. 2  is a side view illustrating a schematic configuration of a state in which the workpiece of the same printing apparatus is moved downward; 
         FIG. 3  is a side view illustrating a schematic configuration when a position of the workpiece of the same printing apparatus is changed; 
         FIG. 4  is a plan view illustrating a configuration of an ink jet part of the same printing apparatus; 
         FIG. 5  is a plan view illustrating another configuration of the ink jet part of the same printing apparatus; 
         FIG. 6  is a plan view illustrating still another configuration of the ink jet part of the same printing apparatus; 
         FIG. 7  is a plan view illustrating still another configuration of the ink jet part of the same printing apparatus; 
         FIG. 8  is a view illustrating a distance between a nozzle of a head part of the same printing apparatus and a surface of the workpiece; 
         FIG. 9  is a view illustrating a distance between the nozzle of the head part and the surface of the workpiece when a position of the workpiece of the same printing apparatus is changed; 
         FIG. 10  is a perspective view illustrating a relationship between the workpiece of the same printing apparatus and a coating line; 
         FIG. 11  is a side view illustrating a state in which a nozzle faces print coordinates of the workpiece of the same printing apparatus; 
         FIG. 12  is a side view illustrating a state in which a nozzle faces the next print coordinates of the workpiece of the same printing apparatus; 
         FIG. 13  is a perspective view illustrating a first region on a curved surface of the workpiece of the same printing apparatus; 
         FIG. 14  is a perspective view illustrating the first region and a second region on the curved surface of the workpiece of the same printing apparatus; 
         FIG. 15  is a side view illustrating a schematic configuration of a printing apparatus according to Exemplary Embodiment 2; 
         FIG. 16  is a side view illustrating a schematic configuration of a printing apparatus according to Exemplary Embodiment 3; 
         FIG. 17  is a side view illustrating a schematic configuration of a printing apparatus according to Exemplary Embodiment 4; 
         FIG. 18  is a side view illustrating a schematic configuration of a printing apparatus according to Exemplary Embodiment 5; 
         FIG. 19  is a front view illustrating a schematic configuration of a printing apparatus according to Exemplary Embodiment 6; 
         FIG. 20  is a view for explaining dispositions of a plurality of ink jet parts when an X-axis linear motion mechanism of Exemplary Embodiment 6 is in one row or two rows; 
         FIG. 21  is a side view illustrating a schematic configuration of a printing apparatus according to Exemplary Embodiment 7; 
         FIG. 22  is a side view illustrating a schematic configuration of a printing apparatus according to Exemplary Embodiment 8; 
         FIG. 23  is a side view illustrating a schematic configuration of a printing apparatus according to Exemplary Embodiment 9; and 
         FIG. 24  is a side view illustrating a schematic configuration of a printing apparatus according to Exemplary Embodiment 10. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, exemplary embodiments of the present disclosure will be described based on the drawings. The following description of the desired exemplary embodiments is essentially merely an example and is not intended to limit the present disclosure, application of the disclosure, or use of the disclosure. 
     Exemplary Embodiment 1 
     Hereinafter, a schematic configuration of printing apparatus  1  of Exemplary Embodiment 1 of the present disclosure will be described based on  FIGS. 1 to 3 . 
       FIG. 1  is a front view illustrating a schematic configuration of printing apparatus  1  according to Exemplary Embodiment 1.  FIG. 2  is a side view illustrating a schematic configuration of printing apparatus  1 .  FIG. 3  is a side view illustrating a schematic configuration when a position of workpiece W of printing apparatus  1  is changed. 
     As illustrated in  FIGS. 1 to 3 , printing apparatus  1  of Exemplary Embodiment 1 is an apparatus that prints a predetermined image by discharging droplet  25  such as ink or a coating material onto workpiece W having a three-dimensional curved surface. Workpiece W is formed of, for example, a resin molded product or the like. 
     Printing apparatus  1  includes printing unit  10 , workpiece drive unit  30 , controller  15 , and the like. Printing apparatus  1  further includes frame  2  and gate-shaped gantry  3  erected from frame  2 . Workpiece drive unit  30  is disposed on frame  2 . Printing unit  10  is disposed on gantry  3 . 
     Printing apparatus  1  of Exemplary Embodiment 1 is configured as described above. 
     Hereinafter, printing apparatus  1  of Exemplary Embodiment 1 will be described by dividing printing apparatus  1  into terms for each component. 
     Printing Unit 
     First, a configuration of printing unit  10  of printing apparatus  1  will be described. 
     As illustrated in  FIG. 1 , printing unit  10  is disposed more upward than a printing surface of workpiece W. Printing unit  10  includes X-axis linear motion mechanism  11  (sometimes referred to as a “main scanning linear motion mechanism”) which is a drive mechanism of one axis, a plurality of ink jet parts  20 , and the like. 
     The X-axis linear motion mechanism  11  is attached to gantry  3 . Each of the plurality of ink jet parts  20  is attached to X-axis linear motion mechanism  11 . X-axis linear motion mechanism  11  moves each of the plurality of ink jet parts  20  in the same main scanning direction (in  FIG. 1 , the horizontal direction (X direction)). 
     Specifically, X-axis linear motion mechanism  11  is configured by a linear motor type drive mechanism. X-axis linear motion mechanism  11  drives each of the plurality of ink jet parts  20  individually in the X direction. As a result, X-axis linear motion mechanism  11  drives only ink jet part  20  that is involved in printing among the plurality of ink jet parts  20  so as to face a surface of workpiece W. At the same time, X-axis linear motion mechanism  11  drives ink jet part  20  that is not involved in the printing so as to retreat from workpiece W. 
     Specifically, at least four ink jet parts  20  are provided, for example, corresponding to four colors of cyan (C), magenta (M), yellow (Y), and black (K). 
     Ink jet part  20  discharges droplet  25  toward workpiece W while moving in the main scanning direction. Ink jet part  20  prints an image on the surface of workpiece W with discharged droplet  25 . At this time, workpiece drive unit  30  further relatively moves workpiece W with respect to ink jet part  20  as illustrated in  FIG. 3 . As a result, the image can be printed in a sub scanning direction (in  FIG. 2 , the horizontal direction (Y direction)) which is orthogonal to the main scanning direction. 
     Next, ink jet part  20  of printing unit  10  will be described with reference to  FIG. 4 .  FIG. 4  is a plan view illustrating a configuration of ink jet part  20  of printing apparatus  1 . 
     As illustrated in  FIG. 4 , ink jet part  20  includes head part  21  and curing part  23 . Head part  21  is provided with four nozzle rows arranged at predetermined intervals in the X direction. The nozzle row includes a plurality of nozzles  22  arranged in one row along the sub scanning direction (Y direction). A pitch between nozzles  22  adjacent to each other in the X direction is set to, for example, 150 dpi to 1200 dpi. A nozzle row having a plurality of nozzles  22  may be arranged side by side in two or more rows along the sub scanning direction. 
     In the example illustrated in  FIG. 4 , in order to explain the pitch between nozzles  22  in an easy-to-understand manner, an example is illustrated in which the plurality of nozzles  22  in the four nozzle rows are arranged side by side at the same position (overlapping position) when viewed from the printing direction, but the present disclosure is not limited to this. For example, the plurality of nozzles  22  in the four nozzle rows may be arranged with being shifted at positions where the plurality of nozzles  22  do not overlap each other when viewed from the printing direction. As a result, the resolution of printing can be increased. 
     Ink jet part  20  is configured by, for example, a piezo type device. Ink jet part  20  discharges a predetermined amount of droplets  25  vertically downward from nozzle  22 , for example, toward the surface of workpiece W, in response to a drive signal supplied from controller  15 . 
     In curing part  23 , the ink or the coating material which is applied to the surface of workpiece W is cured. As curing part  23 , it is appropriately selected from the following devices and the like depending on the type of ink and coating material to be applied. For example, as curing part  23 , an ultraviolet light source such as a metal halide lamp or UV-LED, an infrared light source such as a halogen lamp, an infrared laser diode, or an infrared laser, a heat source by a heater, or the like can be used. 
     In Exemplary Embodiment 1, as illustrated in  FIG. 4 , the configuration in which ink jet part  20  includes head part  21  and one curing part  23  has been described as an example, but the present disclosure is not limited to this. 
     For example, as illustrated in  FIG. 5 , ink jet part  20  may include head part  21 , and two curing parts  23  which are disposed on both sides of head part  21  in the main scanning direction (in  FIG. 5 , the horizontal direction (X direction)). With this configuration, the ink on workpiece W can be efficiently cured by using two curing parts  23  during a reciprocating motion of ink jet part  20  with respect to workpiece W. 
     Further, as illustrated in  FIG. 6 , ink jet part  20  may include head part  21 , curing part  23 , and distance measurement part  24 . Distance measurement part  24  measures a distance between ink jet part  20  and workpiece W. Distance measurement part  24  is appropriately selected depending on the type of material constituting workpiece W. For example, as distance measurement part  24 , a contact type probe, a non-contact type laser displacement meter, an ultrasonic displacement meter, an LED, or the like can be used. Distance measurement part  24  with the above described non-contact type measures a distance based on the time from when workpiece W is irradiated with light until the light returns to a light receiving element (not illustrated). 
     At this time, printing unit  10  of Exemplary Embodiment 1 is configured so as to measure a distance between workpiece W and printing unit  10  by distance measurement part  24  before printing by discharging droplet  25  onto workpiece W for the following reasons. 
     That is, when workpiece W is made of, for example, a resin molded product, a dimensional difference of ±1 mm or more may occur between workpiece W and printing unit  10  with respect to designed CAD data of a product. 
     Therefore, in printing unit  10  of Exemplary Embodiment 1, the distance between ink jet part  20  and workpiece W is measured in advance by distance measurement part  24 . As a result, it is possible to prevent a collision between ink jet part  20  and workpiece W during printing in advance. Further, a printing gap, which is a distance that droplet  25  can reach reliably, can be appropriately set in advance. 
     In addition to measuring the distance between above described ink jet part  20  and workpiece W, a shape of workpiece W may be measured and the shape of workpiece W may be converted into surface data of workpiece W based on the measurement data of the shape by distance measurement part  24 . As a result, the surface data of workpiece W can be used for the printing. Further, distance measurement part  24  may measure only a representative point of an area to be printed and appropriately change the printing gap based on information of the representative point. As a result, the time required for printing can be shortened. 
     The measurement of the distance between workpiece W and printing unit  10  may be obtained with the total number of components to be printed or may be performed by extracting the components to be printed. When workpiece W is made of a material having excellent dimensional stability, it is not necessary to particularly perform the measurement of the distance described above. 
     Further, as illustrated in  FIG. 7 , ink jet part  20  may include only head part  21  and distance measurement part  24 . 
     Ink jet part  20  may be configured such that curing part  23  and distance measurement part  24  are not provided, and only head part  21  is provided alone. As a result, the curved surface that ink jet part  20  can handle increases, the weight of ink jet part  20  can be reduced, and the device configuration can be simplified. 
     Ink jet part  20  may have a configuration having a plurality of head parts  21 . In the case of a configuration having a plurality of head parts  21 , not all head parts  21  need to have different colors, and a plurality of head parts  21  having the same color may be provided. As a result, for example, the amount of white ink that hides the base that is used in a large amount can be increased as compared with the inks of other colors, and the usage time can be extended. Further, when the curved surface is printed by two head parts  21  of the same color, the tact becomes shorter. 
     For example, it may be configured to further include ink jet part  20  of another color, so-called special color, such as light cyan (Lc) or light magenta (Lm) for improving the graininess of an image, green (G), orange (Or), red (R), or violet (V) for expanding the color reproduction region. As a result, the expressiveness of a product package to be printed or the appeal of the product can be improved. Further, it may be configured to add a plurality of color nozzle rows to head part  21  of one ink jet part  20 . As a result, one head can handle a plurality of colors or materials, so that the size can be reduced. 
     When an image is formed on workpiece W of a medium whose base is not white, an ink jet part with white (W) is usually required. In this case, for example, the ink jet part with white (W) may be disposed separately from ink jet part  20  having four colors. 
     An ink jet part for a primer may be provided in order to impart adhesion to the base. An ink jet part for a clear may be provided in order to form an uneven texture or to form a protective layer on the coated color. Further, an ink jet part for a metallic material containing aluminum, gold, silver, copper, and the like may be provided. These ink jet parts do not necessarily have to be provided and may be appropriately disposed as needed. Examples of the desired combination of the ink jet parts described above include (1) cyan, magenta, yellow, and black, (2) white, cyan, magenta, yellow, and black, (3) white, cyan, magenta, yellow, black, and clear, (4) primer, cyan, magenta, yellow, black, and clear, (5) metallic, white, cyan, magenta, yellow, and black, and the like. Further, examples of the combinations include (6) white, cyan, magenta, yellow, black, light cyan, and light magenta, (7) primer, white, cyan, magenta, yellow, black, and clear, and the like. Furthermore, examples of the combinations include (8) metallic, white, cyan, magenta, yellow, black, and clear, (9) metallic, white, cyan, magenta, yellow, black, light cyan, and light magenta, (10) metallic, white, cyan, magenta, yellow, black, light cyan, light magenta, and clear, and the like. 
     The ink or the coating material of each of the above colors is made of, for example, a material that is cured by ultraviolet rays (UV). The ink or the coating material for a primer or a clear may be an ultraviolet type or a solvent type. Further, the ink or the coating material of the metallic material may be an ultraviolet type or a solvent type. 
     As described above, the ink or the coating material of each color is desirably a material that is cured by the ultraviolet rays (UV), but may be a solvent type. That is, the ink that hardens with ultraviolet rays enables drying in a short time. When it is a solvent type, the material can be easily designed, so that there is a possibility that more materials can be used to expand the applicable range. 
     Printing unit  10  of printing apparatus  1  is configured as described above. 
     Workpiece Drive Unit 
     Next, workpiece drive unit  30  of printing apparatus  1  will be described with reference to  FIGS. 1 to 3 . 
     As illustrated in  FIGS. 1 to 3 , workpiece drive unit  30  includes fixing jig  40  attached to a front end having a high degree of freedom of movement. Workpiece W is fixed to fixing jig  40 . Workpiece drive unit  30  transports workpiece W fixed to fixing jig  40  below printing unit  10 . 
     Workpiece drive unit  30  includes drive mechanisms of four axes. Two axes among the drive mechanisms of four axes are Y-axis linear motion mechanism  31  and Z-axis linear motion mechanism  32 . The other two axes among the drive mechanisms of four axes are A-axis rotation mechanism  35  and B-axis rotation mechanism  36 . 
     Y-axis linear motion mechanism  31  is mounted on frame  2 . Y-axis linear motion mechanism  31  moves workpiece W in the sub scanning direction (Y direction). 
     Z-axis linear motion mechanism  32  is attached to Y-axis linear motion mechanism  31 . Z-axis linear motion mechanism  32  moves workpiece W in the vertical direction (Z direction). 
     One end of A-axis rotation mechanism  35  is attached to Z-axis linear motion mechanism  32 , and supporting arm  41  is attached to the other end of A-axis rotation mechanism  35 . A-axis rotation mechanism  35  rotates workpiece W with the A-axis extending in the X direction from Z-axis linear motion mechanism  32  as the center of rotation via supporting arm  41 . 
     B-axis rotation mechanism  36  is attached to A-axis rotation mechanism  35  via supporting arm  41 . Fixing jig  40  is attached to B-axis rotation mechanism  36 . B-axis rotation mechanism  36  rotates workpiece W with the B-axis extending in the Z direction from supporting arm  41  as the center of rotation. 
     Workpiece drive unit  30  operates Y-axis linear motion mechanism  31 , Z-axis linear motion mechanism  32 , A-axis rotation mechanism  35 , and B-axis rotation mechanism  36  based on a signal from controller  15 . As a result, workpiece drive unit  30  moves workpiece W fixed to fixing jig  40  below ink jet part  20 . At this time, workpiece drive unit  30  moves workpiece W while adjusting a position and a position of workpiece W by using the drive mechanisms of four axes (see  FIG. 3 ). 
     Workpiece drive unit  30  of printing apparatus  1  is configured as described above and moves workpiece W. 
     Controller 
     Next, controller  15  of printing apparatus  1  illustrated in  FIG. 1  will be described. 
     Controller  15  is constituted by, for example, a personal computer, a programmable logic controller (PLC), or the like. Controller  15  controls the operations of printing unit  10  and workpiece drive unit  30 . 
     Specifically, controller  15  controls an operation of the plurality of ink jet parts  20  with respect to printing unit  10  via X-axis linear motion mechanism  11 . Further, controller  15  controls such that an appropriate amount of droplets  25  such as ink or coating material are discharged from head part  21  of ink jet part  20  of printing unit  10 . 
     Further, controller  15  controls the operations of Y-axis linear motion mechanism  31 , Z-axis linear motion mechanism  32 , A-axis rotation mechanism  35 , and B-axis rotation mechanism  36  with respect to workpiece drive unit  30 . 
     Controller  15  of printing apparatus  1  is configured as described above. 
     Position and Orientation of Workpiece when Printing 
     Next, a position and an orientation of workpiece W when printing will be described with reference to  FIG. 8 . 
     As illustrated in  FIG. 8 , among the plurality of nozzles  22  of ink jet part  20 , a point where a perpendicular line drawn from nozzle  22   a  in the vicinity of the center toward the surface of workpiece W intersects with the surface of workpiece W, is defined as intersection  75 . A point where a perpendicular line drawn from a point, in which a center line of head part  21  in the X direction and a center line of head part  21  in the Y direction intersect as illustrated by alternate long and short dash lines in  FIG. 4 , toward the surface of workpiece W intersects with the surface of workpiece W may be defined as intersection  75 . As a result, a center position of head part  21  can be set as a center position of the locus, and the calculation can be performed in consideration of symmetry. Therefore, a printing track can be easily calculated by using each of all the nozzle rows. 
     At intersection  75 , tangential line  76  with respect to the surface of workpiece W is parallel to a lower surface of ink jet part  20  (the surface on which nozzle  22  is disposed). A distance between nozzle  22  and the surface of workpiece W is defined as D. 
     As described above, controller  15  controls a drive of the drive mechanism which is constituted by Z-axis linear motion mechanism  32 , Y-axis linear motion mechanism  31 , A-axis rotation mechanism  35 , and B-axis rotation mechanism  36 . At this time, controller  15  controls the drive mechanism so that distance D1 between nozzle  22   a  in the vicinity of the center and intersection  75  on the surface of workpiece W, which is illustrated in  FIG. 8 , is substantially constant (including constant), and adjusts the position and the orientation of workpiece W. 
     Distance D1 is set to any value in the range of, for example, 0.3 mm to 7 mm. As described above, this range is a range in which droplet  25  can be stably applied. Distance D1 is not limited to the above range and can be changed as needed, such as a curved surface of workpiece W or the printing accuracy. 
     However, usually, there are portions having different curvatures on the surface of workpiece W. Therefore, even when controller  15  adjusts distance D1 between nozzle  22   a  in the vicinity of the center and intersection  75  on the surface of workpiece W to be substantially constant (including constant), the distance between nozzle  22  and the surface of workpiece W changes. 
     At this time, in a part where distance D between nozzle  22  and workpiece W is longer than a predetermined value, the time for droplet  25  to reach workpiece W becomes longer. Therefore, droplet  25  discharged from nozzle  22  is easily affected by the surrounding air flow and the like. As a result, a landing position of droplet  25  on workpiece W may shift, causing phenomena such as oozing, blurring, and color shift. That is, when droplet  25  cannot be accurately disposed at a predetermined position on a three-dimensional curved surface on the surface of workpiece W, the image quality of the printed image may deteriorate. 
     For example, a distance between left end nozzle  22  and workpiece W illustrated in  FIG. 9  is longer than a distance between left end nozzle  22  and workpiece W illustrated in  FIG. 8 . Therefore, it is necessary to adjust the coating width of the nozzle row according to the curvature of the surface of workpiece W and dispose droplet  25  with high accuracy. 
     Controller  15  sets a coating region according to the following procedure based on the CAD data and the like. After that, controller  15  applies droplet  25  to the surface of workpiece W by changing the coating width of the nozzle row for each set coating region via ink jet part  20 . 
     Hereinafter, the setting of the coating region will be specifically described with reference to  FIGS. 10 to 14 . 
     First, as illustrated in  FIG. 10 , controller  15  sets coating line  50  on the surface of workpiece W. At this time, it is desirable that coating line  50  is set at a part on the surface of workpiece W that is close to the plane having the smallest curvature. That is, the difference in distance D can be reduced. Therefore, by applying the droplets from a part having a small curvature, it is possible to print using a wide printing width. 
     Next, as illustrated in  FIG. 11 , controller  15  sets a plurality of print coordinates  52  divided into equal pitches  51  on set coating line  50 . Print coordinates  52  are calculated by using the CAD data according to the required necessary print resolution. At this time, for example, print coordinates  52  are desirably set at a pitch of the print resolution. Print coordinates  52  may be set at a pitch that is an integral multiple of the print resolution. As a result, it is possible to suppress an increase in the amount of data and shorten the printing time. Further, when it is set to an integral multiple, data complementation can be easily supplemented. 
     Next, controller  15  relatively moves ink jet part  20  with respect to workpiece W along set coating line  50 . Specifically, ink jet part  20  is relatively moved with respect to workpiece W so that the perpendicular line, which is drawn from nozzle  22   a  in the vicinity of the center of head part  21  of ink jet part  20  toward the surface of workpiece W, coincides with print coordinates  52 . At this time, controller  15  moves workpiece W while adjusting the position and the orientation so that distance D between nozzle  22  and the surface of workpiece W is substantially constant (including constant). 
     Next, as illustrated in  FIG. 12 , controller  15  controls the drive mechanism such that the inclination of line segment  53  connecting print coordinates  52  that faces nozzle  22  and next print coordinates  52  is set to near 0 (zero) (parallel and horizontal to the nozzle surface), and moves and rotates workpiece W. As a result, workpiece W changes from a state illustrated in  FIG. 11  to a state illustrated in  FIG. 12 . In  FIGS. 11 and 12 , the tangential line of the curved surface at each of print coordinates  52  and the nozzle surface are parallel. The tangential line of the curved surface at print coordinates  52  is perpendicular to coating line  50 . 
     Next, controller  15  relatively moves ink jet part  20  with respect to all print coordinates  52  on set coating line  50 . After that, controller  15  selects only nozzle  22  whose distance D between nozzle  22  and the surface of workpiece W is within a certain range D2 at print coordinates  52  among the plurality of nozzles  22  (see  FIGS. 8 and 9 ). Specifically, controller  15  selects only nozzle  22  whose distance D from the surface of workpiece W is within 5 mm, for example. 
     At this time, as illustrated in  FIG. 13 , controller  15  sets a region that can be coated by selected nozzle  22  to first region  55 . Specifically, first region  55  is set in a region interposed between two lines parallel to coating line  50 . 
     Next, after first region  55  is set, controller  15  sets next coating line  54  at a position adjacent to first region  55 , as illustrated in  FIG. 14 . The above-mentioned process is repeated, and a region interposed between the two lines parallel to coating line  54  is set as second region  56 . 
     Further, controller  15  repeatedly sets the above process for a necessary coating region of workpiece W. After that, controller  15  applies droplet  25  for each set coating region via ink jet part  20 . 
     At this time, when the curvature of the surface of each of the coating regions is different, the widths of the coating regions are different. Therefore, the number of nozzles  22  to be selected will also be different. At that time, controller  15  controls distance D between nozzle  22  and the surface of workpiece W so as to be within a certain range (D2). As a result, droplet  25  can be accurately applied to the coating region within distance D2 within a certain range via ink jet part  20 . 
     When the coating region of workpiece W is divided into a plurality of regions, it is desirable to divide workpiece W so that no gap is formed between each of the coating regions. Therefore, controller  15  sets, for example, coating line  54  at an end portion of first region  55 . As a result, no gap is formed between first region  55  and second region  56 . However, even when a gap is formed between the coating regions, separately, another coating region may be provided so as to cover a part where the gap is formed, and then droplet  25  may be applied. 
     In the above description, when distance D between nozzle  22  and the surface of workpiece W is set, although the example described with reference to nozzle  22   a  in the vicinity of the center among the plurality of nozzles  22 , another nozzle  22  may be used as a reference. For example, nozzles  22  disposed at both end portions of the nozzle row may be used as a reference. As a result, it is possible to set a region without a gap or a wide region in particular. Further, it may be configured such that droplet  25  is applied by using different nozzles  22  when setting the region and when coating. That is, for example, when a problem occurs in nozzle  22  that is used when setting a region, nozzle  22  that is used when setting a region is offset when coating instead of using nozzle  22  that is used when setting a region in the region. As a result, even when a problem occurs in nozzle  22 , it can be easily dealt with. 
     When the curvature of the surface of workpiece W is large, nozzle  22  which is used less frequently may be generated. In that case, it is desirable that nozzle  22  that is not used for a certain period of time is configured to perform dummy coating. As a result, unused nozzle  22  can be appropriately cleaned to properly maintain a state of nozzle  22 . 
     As described above, printing apparatus  1  of Exemplary Embodiment 1 can draw a pattern on workpiece W having a curved surface with high accuracy. That is, printing apparatus  1  of Exemplary Embodiment 1 can be used for forming a design for the external appearance of a product, drawing a wiring pattern on a three-dimensional surface, or the like. 
     Exemplary Embodiment 2 
     Hereinafter, a schematic configuration of printing apparatus  1  of Exemplary Embodiment 2 of the present disclosure will be described based on  FIG. 15 . 
       FIG. 15  is a side view illustrating a schematic configuration of printing apparatus  1  according to Exemplary Embodiment 2. Hereinafter, the same parts as those in Exemplary Embodiment 1 are designated by the same reference numerals, and only the differences will be described. 
     As illustrated in  FIG. 15 , printing unit  10  of printing apparatus  1  of Exemplary Embodiment 2 includes X-axis linear motion mechanism  11  which is a drive mechanism of one axis and a plurality of ink jet parts  20 . 
     Workpiece drive unit  30  includes drive mechanisms of four axes. Two axes among the drive mechanisms of four axes are Y-axis linear motion mechanism  31  and Z-axis linear motion mechanism  32 . The other two axes among the drive mechanisms of four axes are A-axis rotation mechanism  35  and B-axis rotation mechanism  36 . 
     One end of B-axis rotation mechanism  36  is attached to Z-axis linear motion mechanism  32  via first arm  61 . B-axis rotation mechanism  36  rotates workpiece W with the B-axis extending in the Y direction from Z-axis linear motion mechanism  32  as the center of rotation. 
     A-axis rotation mechanism  35  is attached to B-axis rotation mechanism  36  via second arm  62 . Fixing jig  40  is attached to A-axis rotation mechanism  35  via third arm  63 . A-axis rotation mechanism  35  rotates workpiece W with A-axis extending in the X direction from second arm  62  as the center of rotation. 
     With the configuration of workpiece drive unit  30 , among the plurality of ink jet parts  20 , only ink jet part  20  including a material that is a printing target can be printed close to workpiece W. As a result, it is possible to prevent the other ink jet part  20  from interfering with workpiece W. As a result, the degree of freedom in a position adjustment motion of workpiece W can be further increased. 
     Exemplary Embodiment 3 
     Hereinafter, a schematic configuration of printing apparatus  1  of Exemplary Embodiment 3 of the present disclosure will be described based on  FIG. 16 . 
       FIG. 16  is a side view illustrating a schematic configuration of printing apparatus  1  according to Exemplary Embodiment 3. Hereinafter, the same parts as those in Exemplary Embodiment 1 are designated by the same reference numerals, and only the differences will be described. 
     As illustrated in  FIG. 16 , printing unit  10  of printing apparatus  1  of Exemplary Embodiment 3 includes drive mechanisms of two axes and a plurality of ink jet parts  20 . The drive mechanisms of two axes includes X-axis linear motion mechanism  11  and a plurality of Y′-axis linear motion mechanisms  13  (sub scanning linear motion mechanism). 
     The plurality of Y′-axis linear motion mechanisms  13  are provided corresponding to each of the plurality of ink jet parts  20 . The plurality of Y′-axis linear motion mechanisms  13  are attached to X-axis linear motion mechanism  11 . Each of the plurality of ink jet parts  20  is attached to X-axis linear motion mechanism  11  via corresponding each of Y′-axis linear motion mechanisms  13 . 
     The plurality of Y′-axis linear motion mechanisms  13  move at least one of the plurality of ink jet parts  20  in the sub scanning direction (Y direction). That is, for example, among the plurality of ink jet parts  20 , only ink jet part  20  including the material (color, raw material, or the like) that is a printing target is moved in the sub scanning direction by the corresponding Y′-axis linear motion mechanism  13 . 
     Workpiece drive unit  30  includes drive mechanisms of four axes. Two axes among the drive mechanisms of four axes are Y-axis linear motion mechanism  31  and Z-axis linear motion mechanism  32 . The other two axes among the drive mechanisms of four axes are A-axis rotation mechanism  35  and B-axis rotation mechanism  36 . 
     With the configuration of Exemplary Embodiment 3, among the plurality of ink jet parts  20 , only ink jet part  20  including a material that is a printing target can be printed close to workpiece W. As a result, it is possible to prevent the other ink jet part  20  from interfering with workpiece W. As a result, the degree of freedom in a position adjustment motion of workpiece W can be further increased. 
     Exemplary Embodiment 4 
     Hereinafter, a schematic configuration of printing apparatus  1  of Exemplary Embodiment 4 of the present disclosure will be described based on  FIG. 17 . 
       FIG. 17  is a side view illustrating a schematic configuration of printing apparatus  1  according to Exemplary Embodiment 4. Hereinafter, the same parts as those in Exemplary Embodiment 1 are designated by the same reference numerals, and only the differences will be described. 
     As illustrated in  FIG. 17 , printing unit  10  of printing apparatus  1  of Exemplary Embodiment 4 includes drive mechanisms of two axes and a plurality of ink jet parts  20 . The drive mechanisms of two axes includes X-axis linear motion mechanism  11  and a plurality of Z′-axis linear motion mechanisms  14  (forward and backward linear motion mechanism). 
     The plurality of Z′-axis linear motion mechanisms  14  are provided corresponding to each of the plurality of ink jet parts  20 . The plurality of Z′-axis linear motion mechanisms  14  are attached to X-axis linear motion mechanism  11 . Each of the plurality of ink jet parts  20  is attached to X-axis linear motion mechanism  11  via corresponding each of Z′-axis linear motion mechanisms  14 . 
     The plurality of Z′-axis linear motion mechanisms  14  move at least one of the plurality of ink jet parts  20  forward and backward in the Z direction with respect to workpiece W. That is, for example, among the plurality of ink jet parts  20 , only ink jet part  20  including the material (color, raw material, or the like) that is a printing target is moved downward by the corresponding Z′-axis linear motion mechanism  14 . 
     Workpiece drive unit  30  includes drive mechanisms of four axes. Two axes among the drive mechanisms of four axes are Y-axis linear motion mechanism  31  and Z-axis linear motion mechanism  32 . The other two axes among the drive mechanisms of four axes are A-axis rotation mechanism  35  and B-axis rotation mechanism  36 . 
     With the configuration of Exemplary Embodiment 4, among the plurality of ink jet parts  20 , only ink jet part  20  including a material that is a printing target can be printed close to workpiece W. As a result, it is possible to prevent the other ink jet part  20  from interfering with workpiece W. As a result, the degree of freedom in a position adjustment motion of workpiece W can be further increased. 
     Further, even when the surface of workpiece W has a recessed portion, only the corresponding ink jet part  20  can be brought close to the recessed portion to discharge droplet  25 . As a result, it is possible to draw a pattern on workpiece W with high accuracy. 
     Exemplary Embodiment 5 
     Hereinafter, a schematic configuration of printing apparatus  1  of Exemplary Embodiment 5 of the present disclosure will be described based on  FIG. 18 . 
       FIG. 18  is a side view illustrating a schematic configuration of printing apparatus  1  according to Exemplary Embodiment 5. Hereinafter, the same parts as those in Exemplary Embodiment 1 are designated by the same reference numerals, and only the differences will be described. 
     As illustrated in  FIG. 18 , printing unit  10  of printing apparatus  1  of Exemplary Embodiment 4 includes drive mechanisms of two axes and a plurality of ink jet parts  20 . The drive mechanisms of two axes includes X-axis linear motion mechanism  11  and a plurality of C′-axis rotation mechanisms  38 . 
     The plurality of C′-axis rotation mechanisms  38  are provided corresponding to each of the plurality of ink jet parts  20 . The plurality of C′-axis rotation mechanisms  38  are attached to X-axis linear motion mechanism  11 . Each of the plurality of ink jet parts  20  is attached to X-axis linear motion mechanism  11  via corresponding each of C′-axis rotation mechanisms  38 . The C′-axis rotation mechanism  38  rotates head part  21  in the horizontal direction with C′-axis extending in the Z direction as the center of rotation. 
     Workpiece drive unit  30  includes drive mechanisms of four axes. Two axes among the drive mechanisms of four axes are Y-axis linear motion mechanism  31  and Z-axis linear motion mechanism  32 . The other two axes among the drive mechanisms of four axes are A-axis rotation mechanism  35  and B-axis rotation mechanism  36 . 
     According to the configuration of Exemplary Embodiment 5, ink jet part  20  can be moved in the main scanning direction by X-axis linear motion mechanism  11  and a position of nozzle  22  of head part  21  with respect to workpiece W can be finely adjusted in the horizontal direction by C′-axis rotation mechanism  38 . 
     Specifically, for example, rows of a plurality of nozzles  22  arranged in one row along the sub scanning direction of ink jet part  20  are formed in a position inclined obliquely with respect to the main scanning direction. As a result, the pitch between nozzles  22  can be reduced and the print resolution can be increased. 
     The printing direction can be changed by rotating the row of nozzles  22  of ink jet part  20  by 90° with respect to the main scanning direction. As a result, the landing accuracy of droplet  25  can be improved. 
     Exemplary Embodiment 6 
     Hereinafter, a schematic configuration of printing apparatus  1  of Exemplary Embodiment 6 of the present disclosure will be described based on  FIG. 19 . 
       FIG. 19  is a front view illustrating a schematic configuration of printing apparatus  1  according to Exemplary Embodiment 6. Hereinafter, the same parts as those in Exemplary Embodiment 1 are designated by the same reference numerals, and only the differences will be described. 
     As illustrated in  FIG. 19 , workpiece drive unit  30  of printing apparatus  1  of Exemplary Embodiment 6 includes drive mechanisms of four axes. Two axes among the drive mechanisms of four axes are Y-axis linear motion mechanism  31  and Z-axis linear motion mechanism  32 . The other two axes among the drive mechanisms of four axes are A-axis rotation mechanism  35  and B-axis rotation mechanism  36 . 
     Printing unit  10  includes X-axis linear motion mechanism  11  and a plurality of ink jet parts  20 . 
     X-axis linear motion mechanism  11  includes first X-axis linear motion mechanism  11   a  (first main scanning linear motion mechanism) and second X-axis linear motion mechanism  11   b  (second main scanning linear motion mechanism). First X-axis linear motion mechanism  11   a  and second X-axis linear motion mechanism  11   b  are disposed in parallel with each other in the X direction. First X-axis linear motion mechanism  11   a  is disposed more upward than second X-axis linear motion mechanism  11   b.    
     For example, two ink jet parts  20  are attached to first X-axis linear motion mechanism  11   a . Specifically, ink jet part  20  is attached to first X-axis linear motion mechanism  11   a  via first supporting member  45 . 
     First supporting member  45  includes horizontal part  45   a  extending along first X-axis linear motion mechanism  11   a  in the horizontal direction and vertical part  45   b  extending downward from a left end portion of horizontal part  45   a . Ink jet part  20  is attached to a lower end portion of vertical part  45   b.    
     On the other hand, for example, two ink jet parts  20  are attached to second X-axis linear motion mechanism  11   b . Ink jet part  20  is attached to second X-axis linear motion mechanism  11   b  via second supporting member  46 . Second supporting member  46  extends along second X-axis linear motion mechanism  11   b  in the horizontal direction. 
     Four ink jet parts  20  are arranged so as to line up in the X direction. Four ink jet parts  20  are alternately attached to first X-axis linear motion mechanism  11   a  and second X-axis linear motion mechanism  11   b.    
     Specifically, ink jet part  20  which is first from the left in  FIG. 19  is attached to first X-axis linear motion mechanism  11   a  via first supporting member  45 . Ink jet part  20  which is second from the left is attached to second X-axis linear motion mechanism  11   b  via second supporting member  46 . 
     Ink jet part  20  which is third from the left in  FIG. 19  is attached to first X-axis linear motion mechanism  11   a  via first supporting member  45 . Ink jet part  20  which is fourth from the left is attached to second X-axis linear motion mechanism  11   b  via second supporting member  46 . 
     Each of the nozzle surfaces of four ink jet parts  20  is disposed at positions on substantially the same plane (including on the same plane). 
     With the above configuration, the entire length of printing apparatus  1  in the X direction can be reduced as described below with reference to  FIG. 20 . 
     That is, as illustrated in the upper part in  FIG. 20 , when X-axis linear motion mechanism  11  is in one row, each of four ink jet parts  20  is held by X-axis linear motion mechanism  11  by second supporting member  46 . Therefore, when four ink jet parts  20  are moved to the left side in a state where second supporting members  46  maintain gaps that do not interfere with each other, a distance between the center of ink jet part  20  positioned at the left end and the center of ink jet part  20  positioned at the right end is A1. 
     On the other hand, as illustrated in the lower part in  FIG. 20 , X-axis linear motion mechanism  11  of Exemplary Embodiment 6 is configured by two rows in which first X-axis linear motion mechanism  11   a  and second X-axis linear motion mechanism  11   b  are disposed in parallel with each other in the Z direction. Ink jet parts  20  which are first and third from the left are attached to first X-axis linear motion mechanism  11   a  via first supporting member  45 . On the other hand, ink jet parts  20  which are second and fourth from the left are attached to second X-axis linear motion mechanism  11   b  via second supporting member  46 . 
     Vertical part  45   b  of first supporting member  45  is configured to have a shape smaller than the horizontal width of ink jet part  20  in the X direction. Therefore, when moving while maintaining a gap that does not interfere with two ink jet parts  20  held by first supporting member  45  and two ink jet parts  20  held by second supporting member  46  of four ink jet parts  20 , a distance between the center of ink jet part  20  positioned at the left end and the center of ink jet part  20  positioned at the right end is A2. 
     As a result, it becomes A2&lt;A1. 
     That is, the gap between ink jet part  20  attached to first X-axis linear motion mechanism  11   a  and ink jet part  20  attached to second X-axis linear motion mechanism  11   b  can be set small. As a result, the entire length of printing apparatus  1  in the X direction can be reduced. 
     Exemplary Embodiment 7 
     Hereinafter, a schematic configuration of printing apparatus  1  of Exemplary Embodiment 7 of the present disclosure will be described based on  FIG. 21 . 
       FIG. 21  is a side view illustrating a schematic configuration of printing apparatus  1  according to Exemplary Embodiment 7. Hereinafter, the same parts as those in Exemplary Embodiment 1 are designated by the same reference numerals, and only the differences will be described. 
     As illustrated in  FIG. 21 , printing unit  10  of printing apparatus  1  of Exemplary Embodiment 7 includes X-axis linear motion mechanism  11  and a plurality of ink jet parts  20 . 
     Workpiece drive unit  30  includes drive mechanisms of five axes. Two axes among the drive mechanisms of five axes are Y-axis linear motion mechanism  31  and Z-axis linear motion mechanism  32 . The other three axes among the drive mechanisms of five axes are A-axis rotation mechanism  35 , B-axis rotation mechanism  36 , and C-axis rotation mechanism  37 . 
     C-axis rotation mechanism  37  is attached to Z-axis linear motion mechanism  32  via first arm  61 . C-axis rotation mechanism  37  rotates workpiece W with C-axis extending in the Z direction from first arm  61  as the center of rotation. 
     A-axis rotation mechanism  35  is attached to C-axis rotation mechanism  37  via second arm  62 . A-axis rotation mechanism  35  rotates workpiece W with A-axis extending in the X direction from second arm  62  as the center of rotation. 
     B-axis rotation mechanism  36  is attached to A-axis rotation mechanism  35  via an arm (not illustrated). Fixing jig  40  is attached to B-axis rotation mechanism  36 . B-axis rotation mechanism  36  rotates workpiece W with the B-axis extending in the Y direction as the center of rotation. 
     According to the configuration of Exemplary Embodiment 7, the number of drive mechanisms of workpiece drive unit  30  can be increased. As a result, the adjustment range of the position of workpiece W can be further widened. 
     Exemplary Embodiment 8 
     Hereinafter, a schematic configuration of printing apparatus  1  of Exemplary Embodiment 8 of the present disclosure will be described based on  FIG. 22 . 
       FIG. 22  is a side view illustrating a schematic configuration of printing apparatus  1  according to Exemplary Embodiment 8. Hereinafter, the same parts as those in Exemplary Embodiment 1 are designated by the same reference numerals, and only the differences will be described. 
     As illustrated in  FIG. 22 , printing unit  10  of printing apparatus  1  of Exemplary Embodiment 8 includes X-axis linear motion mechanism  11  and a plurality of ink jet parts  20 . 
     Workpiece drive unit  30  includes drive mechanisms of five axes. Two axes among the drive mechanisms of five axes are Y-axis linear motion mechanism  31  and Z-axis linear motion mechanism  32 . The other three axes among the drive mechanisms of five axes are A-axis rotation mechanism  35 , B-axis rotation mechanism  36 , and C-axis rotation mechanism  37 . 
     A-axis rotation mechanism  35  is attached to Z-axis linear motion mechanism  32 . A-axis rotation mechanism  35  rotates workpiece W with the A-axis extending in the X direction from Z-axis linear motion mechanism  32  as the center of rotation. 
     B-axis rotation mechanism  36  is attached to A-axis rotation mechanism  35  via box-shaped holding body  42  in which an upper side is opened. B-axis rotation mechanism  36  rotates workpiece W with the B-axis extending in the Y direction from A-axis rotation mechanism  35  as the center of rotation. Holding body  42  is formed in a box shape with an open upper portion, and houses supporting arm  41 , B-axis rotation mechanism  36 , and the like inside. Therefore, workpiece drive unit  30  can be made smaller. 
     C-axis rotation mechanism  37  is attached to B-axis rotation mechanism  36  via supporting arm  41 . Fixing jig  40  is attached to the front end side of C-axis rotation mechanism  37 . C-axis rotation mechanism  37  rotates workpiece W with C-axis extending in the Z direction from supporting arm  41  as the center of rotation. 
     According to the configuration of Exemplary Embodiment 8, the number of drive mechanisms of workpiece drive unit  30  can be increased. As a result, the adjustment range of the position of workpiece W can be further widened. 
     Exemplary Embodiment 9 
     Hereinafter, a schematic configuration of printing apparatus  1  of Exemplary Embodiment 9 of the present disclosure will be described based on  FIG. 23 . 
       FIG. 23  is a side view illustrating a schematic configuration of printing apparatus  1  according to Exemplary Embodiment 9. Hereinafter, the same parts as those in Exemplary Embodiment 1 are designated by the same reference numerals, and only the differences will be described. 
     As illustrated in  FIG. 23 , printing unit  10  of printing apparatus  1  of Exemplary Embodiment 9 includes X-axis linear motion mechanism  11  and a plurality of ink jet parts  20 . 
     Workpiece drive unit  30  includes drive mechanisms of five axes. Two axes among the drive mechanisms of five axes are Y-axis linear motion mechanism  31  and Z-axis linear motion mechanism  32 . The other three axes among the drive mechanisms of five axes are A-axis rotation mechanism  35 , B-axis rotation mechanism  36 , and C-axis rotation mechanism  37 . 
     A-axis rotation mechanism  35  is attached to Z-axis linear motion mechanism  32 . A-axis rotation mechanism  35  rotates workpiece W with the A-axis extending in the X direction from Z-axis linear motion mechanism  32  as the center of rotation. 
     B-axis rotation mechanism  36  is attached to A-axis rotation mechanism  35  via first arm  61 . B-axis rotation mechanism  36  rotates workpiece W with the B-axis extending in the Y direction from first arm  61  as the center of rotation. 
     C-axis rotation mechanism  37  is attached to B-axis rotation mechanism  36  via second arm  62 . Fixing jig  40  is attached to C-axis rotation mechanism  37 . C-axis rotation mechanism  37  rotates workpiece W with C-axis extending in the Z direction from second arm  62  as the center of rotation. 
     According to the configuration of Exemplary Embodiment 9, the number of drive mechanisms of workpiece drive unit  30  can be increased. As a result, the adjustment range of the position of workpiece W can be further widened. 
     Exemplary Embodiment 10 
     Hereinafter, a schematic configuration of printing apparatus  1  of Exemplary Embodiment 10 of the present disclosure will be described based on  FIG. 24 . 
       FIG. 24  is a side view illustrating a schematic configuration of printing apparatus  1  according to Exemplary Embodiment 10. Hereinafter, the same parts as those in Exemplary Embodiment 1 are designated by the same reference numerals, and only the differences will be described. 
     As illustrated in  FIG. 24 , printing unit  10  of printing apparatus  1  of Exemplary Embodiment 10 includes X-axis linear motion mechanism  11  and a plurality of ink jet parts  20 . 
     Workpiece drive unit  30  includes drive mechanisms of five axes. Two axes among the drive mechanisms of five axes are Y-axis linear motion mechanism  31  and Z-axis linear motion mechanism  32 . The other three axes among the drive mechanisms of five axes are A-axis rotation mechanism  35 , B-axis rotation mechanism  36 , and C-axis rotation mechanism  37 . 
     Y-axis linear motion mechanism  31  is mounted on frame  2 . Y-axis linear motion mechanism  31  moves workpiece W in the sub scanning direction. 
     C-axis rotation mechanism  37  is attached to Y-axis linear motion mechanism  31 . C-axis rotation mechanism  37  rotates workpiece W with C-axis extending in the Z direction from Y-axis linear motion mechanism  31  as the center of rotation. 
     Z-axis linear motion mechanism  32  is attached to C-axis rotation mechanism  37 . Z-axis linear motion mechanism  32  moves workpiece W in the vertical direction. 
     A-axis rotation mechanism  35  is attached to Z-axis linear motion mechanism  32 . A-axis rotation mechanism  35  rotates workpiece W with the A-axis extending in the X direction from Z-axis linear motion mechanism  32  as the center of rotation. 
     B-axis rotation mechanism  36  is attached to A-axis rotation mechanism  35  via first arm  61 . Fixing jig  40  is attached to B-axis rotation mechanism  36  via second arm  62 . B-axis rotation mechanism  36  rotates workpiece W with the B-axis extending in the Y direction from first arm  61  as the center of rotation. 
     According to the configuration of Exemplary Embodiment 10, the number of drive mechanisms of workpiece drive unit  30  can be increased. As a result, the adjustment range of the position of workpiece W can be further widened.