Patent Publication Number: US-9901156-B2

Title: Drawing apparatus and drawing method for drawing apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present invention contains subject matter related to Japanese Patent Application No. 2015-252308 filed in the Japanese Patent Office on Dec. 24, 2015, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a drawing apparatus and a drawing method for a drawing apparatus. 
     2. Description of the Related Art 
     Conventionally, drawing apparatuses (nail printing apparatus) for drawing nail designs such as colors, and patterns on the surface of nails are known. An example of such a drawing apparatus is described in Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2003-534083. 
     Applying a plotter drawing apparatus, in which a drawing utensil (a drawing tool, namely a pen) for performing the drawing is mounted, to such a drawing apparatus is also being investigated. 
     Compared to an ink jet type drawing apparatus in which small droplets of ink are discharged, there are fewer restrictions related to the viscosity of usable inks, the particle size of the coloring material included in the ink, and the like in cases where drawing is performed using a pen. With the latter, inks with excellent color development that include coloring material that has a large particle size, and high-viscosity inks such as light-curable inks can be used. With such drawing apparatuses, it is possible to draw various types of nail designs, the same as would be performed at a nail salon. 
     Drawing apparatuses in which a pen is used are configured such that drawing is performed on a nail in a state where the pen is in contact with the surface of the nail. As such, in cases where the drawing object, namely the nail, has a damaged portion such as a chip, or a crack, the pen tip may catch or get stuck on the damaged portion when attempting to draw at this location. 
     Moving the pen in such a state may result in a major accident (injury) such as, for example, the caught pen tip cracking the nail even further or peeling the nail off. 
     Thus, when performing drawing on nail that has a damaged portion such as a chip, or a crack, there are cases where the nail design does not turn out as expected and the finish is not beautiful. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is advantageous in that a drawing apparatus and a drawing method for a drawing apparatus are provided whereby a condition of a drawing object, the drawing object being a nail, is determined and, as a result thereof, drawing processing on the drawing object can be performed safely and a certain degree of drawing quality can be ensured. 
     A drawing apparatus of the present invention by which the advantages described above are obtained includes an object mounting portion on which an object, namely at least one finger or toe, is mounted, and a processor. In such a drawing apparatus, the processor detects an actual outline, which indicates an actual shape of an outer periphery of a nail, from a captured image. The captured image is obtained by imaging a nail that constitutes a drawing object of the object mounted on the object mounting portion. Furthermore, the processor creates an interpolation outline from the captured image in which the outline of the outer periphery of the nail is smoothly interpolated; and determines whether or not the nail has a damaged portion on the basis of a comparison of the interpolation outline with the actual outline. 
     In a drawing method for a drawing apparatus of the present invention by which the advantages described above are obtained, the drawing apparatus includes an object mounting portion on which an object, namely at least one finger or toe is mounted. The drawing method includes an actual outline detection step of detecting an actual outline, which indicates an actual shape of an outer periphery of a nail, from a captured image. The captured image is obtained by imaging a nail that constitutes a drawing object of the object mounted on the object mounting portion. The drawing method further includes an interpolation outline creation step of creating an interpolation outline, in which an outline of the outer periphery of the nail is smoothly interpolated, from the captured image; and a damaged portion determination step of determining whether or not the nail has a damaged portion on the basis of a comparison of the interpolation outline with the actual outline. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         FIG. 1A  is a front view of a drawing apparatus according to an embodiment of the present invention.  FIG. 1B  is a side view illustrating an internal configuration of the drawing apparatus illustrated in  FIG. 1A . 
         FIG. 2A  is a top view of a drawing head according to the embodiment of the present invention.  FIG. 2B  is a side view of the drawing head according to the embodiment of the present invention. 
         FIG. 3  is a main constituent block diagram showing a control configuration of the drawing apparatus according to the embodiment of the present invention. 
         FIG. 4A  is an explanatory drawing illustrating a state where the actual outline and the interpolation outline of the nail are compared.  FIG. 4B  is an explanatory drawing illustrating a difference portion between the actual outline and the interpolation outline. 
         FIG. 5  is a flowchart showing damaged portion determination processing and drawing processing of the drawing apparatus according to the embodiment of the present invention. 
         FIG. 6A  is a plan view of a nail, illustrating a state where a nail design is drawn on a nail that has a damaged portion.  FIG. 6B  is a plan view of a nail, illustrating a state where correction is performed for moving a nail design to a position where the damaged portion is avoided, and the nail design is drawn. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An embodiment of the nail printing apparatus (drawing apparatus) and drawing method for the nail printing apparatus (drawing apparatus) according to the present invention is described below in detail while referring to the drawings. 
     While various limitations, which are technically preferable from the perspective of carrying out the present invention, are placed on the embodiment described below, the scope of the present invention should not be construed to be limited to the embodiment or the example illustrated in the drawings. 
     In the following embodiment, a nail printing apparatus  1  will be described as an apparatus for drawing on a drawing object, namely a fingernail. However, the drawing object of the present invention is not limited to a fingernail and, for example, may be a toenail. 
       FIG. 1A  is a front view of a nail printing apparatus  1 , illustrating an internal configuration of the nail printing apparatus.  FIG. 1B  is a side view illustrating the internal configuration of the nail printing apparatus illustrated in  FIG. 1A . 
     As illustrated in  FIGS. 1A and 1B , in the nail printing apparatus  1  of the present embodiment, a drawing head  43  is provided with drawing tools, namely a pen  41  and an ink jet drawing portion  71 . The nail printing apparatus  1  of the present embodiment uses plotter printing and ink jet printing to perform a drawing on a nail T of a print finger U 1 . 
     The nail printing apparatus  1  is provided with a case body  2  and an apparatus main body  10  housed in the case body  2 . 
     A cover  23 , configured to be openable and closeable, for replacing the pen  41  and the ink jet drawing portion  71  of the hereinafter described drawing unit  40  is provided in an end of an upper portion of a side surface of the case body  2 . 
     The cover  23  is pivotable via, for example, a hinge or the like, from a closed state to an open state, as illustrated in  FIG. 1A . 
     An operation unit  25  (see  FIG. 3 ) is set on an upper surface (top panel) of the case body  2 . 
     The operation unit  25  is an input unit where a user performs various types of input. 
     Operation buttons (not illustrated) for performing various types of input are set in the operation unit  25 . Examples of the operation buttons include a power switch button for turning on the power of the nail printing apparatus  1 , a stop switch button for stopping operation, a design selection button for selecting a design image to be drawn on the nail T, a drawing start button for commanding the drawing to start, and the like. 
     A display unit  26  is set approximately in a center portion of the top surface (top panel) of the case body  2 . 
     The display unit  26  is configured from, for example, a liquid crystal display (LCD), an organic electroluminescence display, or other type of flat display. 
     In the present embodiment, examples of images appropriately displayed on the display unit  26  include nail images obtained by imaging the print finger U 1  (finger images including images of the nail T), images of the outline or the like of the nail T included in the nail images, design selection images for selecting a design image to be drawn on the nail T, thumbnail images for design confirmation, command screens displaying various commands, and the like. 
     As described hereinafter, in the present embodiment, a configuration is provided in which the display unit  26  is caused to display a notification in cases where the nail T has a damaged portion Ba (see  FIG. 4A ) so as to inform and alert a user. Thus, the display unit  26  functions as notification unit. 
     Note that a configuration is possible in which a touch panel for performing various types of input is integrated into the surface of the display unit  26 . 
     The apparatus main body  10  is formed into a rough box-shape and is provided with a lower frame  11  set in the lower portion of the interior of the case body  2 , and an upper frame  12  set above the lower frame  11  and in the upper portion of the interior of the case body  2 . 
     First, the lower frame  11  will be described. 
     The lower frame  11  has a back surface plate  111 , a bottom plate  112 , a pair of left and right side plates  113   a  and  113   b , an X-direction movement stage housing  114 , a Y-direction movement stage housing  115 , and a dividing wall  116 . 
     Bottom edges of the side plates  113   a  and  113   b  are joined respectively to left and right edges of the bottom plate  112 . The side plates  113   a  and  113   b  are provided in an upright state on the bottom plate  112 . 
     A lower portion of the back surface plate  111  is formed so as to sink forward (toward the finger insertion direction proximal side) in two stages. The bottom edge of the back surface plate  111  is joined to a front edge of the bottom plate  112 , and the back surface plate  111  divides the area surrounded by the bottom plate  112  and the side plates  113   a  and  113   b  into front and back. 
     The space formed on the back side of the sunken back surface plate  111  becomes the X-direction movement stage housing  114  and the Y-direction movement stage housing  115  (see  FIG. 1B ). 
     An X-direction movement stage  45  of the drawing unit  40  is housed in the X-direction movement stage housing  114  when the drawing unit  40  is moved forward (toward the finger insertion direction proximal side). 
     A Y-direction movement stage  47  of the drawing unit  40  is disposed in the Y-direction movement stage housing  115 . 
     The dividing wall  116  is provided inside the lower frame  11  so as to vertically divide the space on the front side inside the lower frame  11  (the space on the finger insertion direction proximal side surrounded by the back surface plate  111 , the bottom plate  112 , and the side plates  113   a  and  113   b ). 
     The dividing wall  116  is provided roughly horizontally, left and right edges of the dividing wall  116  are joined respectively to the side plates  113   a  and  113   b , and a back edge of the dividing wall  116  is joined to the back surface plate  111 . 
     A finger securing portion  30  (see  FIG. 1B ) is provided integrally in the lower frame  11 . 
     The finger securing portion  30  is configured from a finger receiving portion  31  for receiving the finger corresponding to the nail T (i.e. the drawing object) on which drawing will be performed (hereinafter referred to as “print finger U 1 ”), and a finger clearing portion  32  for clearing fingers other than the print finger U 1  (hereinafter referred to as “non-print fingers U 2 ”). 
     The finger receiving portion  31  is disposed on an upper side of the dividing wall  116  and, for example, slightly right of the center in a width direction of the lower frame  11 . 
     The space on the lower side of the lower frame  11 , partitioned by the dividing wall  116 , forms the finger clearing portion  32 . 
     For example, in cases where performing a drawing on the nail T of a ring finger, the ring finger is inserted into the finger receiving portion  31  as the print finger U 1 , and the non-print fingers U 2 , namely the other four fingers (thumb, index finger, middle finger, and little finger) are inserted into the finger clearing portion  32 . 
     The finger receiving portion  31  is open to a front surface side of the lower frame  11  (print finger insertion direction proximal side); and a bottom side is a finger mount portion  33  that is constituted by a portion of a top side of the dividing wall  116 . 
     The finger mount portion  33  is a constituent where the finger (the print finger U 1 ) of the nail T on which drawing is to be performed is mounted on the X-Y plane. 
     A top side of the finger receiving portion  31  is open and a surface of the nail T of the print finger U 1  inserted in the finger receiving portion  31  (i.e. the drawing object surface) is exposed. 
     A front wall  31   f  (see  FIG. 1A ) that closes the front surface side of the lower frame  11  is provided on the top surface of the dividing wall  116 , at both end portions on the front surface side of the lower frame  11 . 
     A pair of guide walls  31   g  (see  FIG. 1A ) that guides the print finger U 1  into the finger receiving portion  31  is erected on the top surface of the dividing wall  116 , and the pair of guide walls  31   g  narrows from the end of the front wall  31   f  on the center portion side toward the finger receiving portion  31 . 
     A user can pinch the dividing wall  116  between the print finger U 1  inserted in the finger receiving portion  31  and the non-print fingers U 2  inserted in the finger clearing portion  32 . Thus, the print finger U 1  inserted in the finger receiving portion  31  is stably secured. 
     A test drawing portion  61  is provided on the top surface of the lower frame  11 , beside the finger receiving portion  31  (location corresponding to a media access port  24  of the case body  2 , on the left side in  FIG. 1A ). The test drawing portion  61  is for performing test drawing to warm up a pen tip  413  (described hereinafter) to eliminate fading and the like at a time of beginning of drawing by the pen tip (tip portion)  413  of the pen  41  within a drawable area of the drawing head  43  (described hereinafter). 
     The test drawing portion  61  is a flat portion and is configured so that drawing media (not illustrated) inserted through the media access port  24  of the case body  2  is mounted thereon. 
     The drawing media mounted on the test drawing portion  61  is not limited, provided that test drawing of the pen tip (tip portion)  413  can be performed, and for example, may be a piece of paper. 
     A pen cap  62  is disposed within a movable range of the drawing head  43  (described hereinafter) on the top surface of the lower frame  11 , on a side opposite the test drawing portion  61  across the finger receiving portion  31  (in the present embodiment, the right side in  FIG. 1A ). The number of the pen cap  62  disposed (one in the present embodiment) corresponds to the number of a pen holder  42  (described hereinafter). 
     The pen cap  62  is formed, for example, from rubber, and at times when the pen  41  is mounted to the drawing unit  40  but not drawing (when not drawing), drying out of the pen tip  413  is prevented by lowering the pen  41  and storing the pen tip  413  in the pen cap  62 . 
     An ink jet maintenance portion  63  is provided at a position corresponding to a position where the ink jet drawing portion  71  is disposed when the pen tip  413  is stored in the pen cap  62 . The ink jet maintenance portion  63  is configured from, for example, a cleaning mechanism for cleaning an ink discharging portion (nozzle surface) of the ink jet drawing portion  71  described hereinafter, a cap mechanism for maintaining moist conditions of the ink discharging portion (nozzle surface), and the like (all not illustrated). 
     Note that the disposal of the pen cap  62 , the ink jet maintenance portion  63 , and the like is not limited to the examples described herein. 
     The drawing unit  40  is configured from and provided with the drawing head  43 , a unit supporting member  44  that supports the drawing head  43 , the X-direction movement stage  45  for moving the drawing head  43  in the X direction (the X direction in  FIG. 1A ; the left-right direction of the drawing apparatus  1 ), an X-direction movement motor  46 , the Y-direction movement stage  47  for moving the drawing head  43  in the Y direction (the Y direction in  FIG. 1B ; the front-back direction of the drawing apparatus  1 ), a Y-direction movement motor  48 , and the like. 
       FIG. 2A  is a top view of a drawing head and  FIG. 2B  is a side view of the drawing head according to the present embodiment. 
     As illustrated in  FIGS. 2A and 2B , in the drawing head  43  of the present embodiment, the pen holder  42  holding the pen  41  and an ink jet holder  72  holding the ink jet drawing portion  71  are disposed adjacently to each other. 
     The ink jet drawing portion  71  is, for example, an ink cartridge-integrated head in which ink cartridges (not illustrated) corresponding to yellow (Y), magenta (M), and cyan (C) ink are formed integrally with an ink discharging portion (not illustrated) provided on a surface (in the present embodiment, the bottom surface in  FIG. 1A  and the like) facing the drawing object (the nail T) in each of the ink cartridges. 
     The ink discharging portion is provided with a nozzle array consisting of a plurality of nozzles for spraying each color of ink. The ink jet drawing portion  71  micronizes the ink and performs the drawing by spraying the ink from the ink discharging portion directly on the target drawing surface of the drawing object (the nail T). 
     Note that the ink jet drawing portion  71  is not limited to those that discharge the three colors of ink described previously. Ink cartridges holding other colors of ink and ink discharging portions may also be provided. 
     One pen  41  is mountable in the pen holder  42  of the present embodiment, and this pen  41  is replaceable in the pen holder  42 . 
     The pen  41  is a writing utensil that has the surface of the nail T as its drawing object surface, and performs a drawing by the tip portion thereof being brought into contact with the drawing object surface, namely the surface of the nail T. 
     As illustrated in  FIG. 2B  and the like, the pen  41  is provided with the pen tip  413  on a tip side (the lower side in  FIG. 2B ) of a rod-like pen shaft portion  411 . 
     An interior of the pen shaft portion  411  is an ink storing portion for storing various types of ink. 
     Any type of ink can be stored in the interior of the pen shaft portion  411 . Viscosity of ink, diameter of the coloring particles (particle size), and the like are not particularly limited and, for example, ink containing metallic glitter, white ink, UV-curable ink, ink for gel nails, ink for under coats, ink for top coats, nail varnish, and the like can be used. 
     In the present embodiment, the pen  41  is a ballpoint pen in which the pen tip  413  draws by the ink stored in the pen shaft portion  411  being dispensed by pressing the pen tip  413  against the surface of the nail T. 
     Note that the pen  41  is not limited to a ballpoint pen. For example, the pen  41  may be a felt-tip pen that draws by soaking ink into a felt-like pen tip, a brush pen that draws by soaking ink into a bundle of hairs, or the like. 
     The pen  41  having the pen tip  413  of any desired thickness may be used as well. 
     Each of the pens  41  that is replaced and set in the pen holder  42  may be pens that all have the same type of the pen tip  413 , or may be pens that have different types of the pen tip  413 . 
     The pen  41  is held by simply inserting it in the pen holder  42  from above. As such, the pen  41  can be easily replaced by a user by opening the cover  23  provided in the case body  2  and, for example, using hands or tweezers to grab a top end portion of the pen shaft portion  411  and lift the pen  41  out. 
     Thus, a user can realize a wide range of nail designs by appropriately replacing the pen  41  set in the pen holder  42  for a pen  41  having a different color or a different pen tip  413 , or using a different type of ink, depending on the nail design desired to be drawn. 
     The pen holder  42  is provided with a tubular member  421  that is open vertically and into which the pen  41  is inserted, a pen retaining member  422  disposed so as to block an opening on a bottom side of the tubular member  421  (the bottom side in  FIG. 2B ), and an auxiliary rod member  423  that moves vertically with the pen  41 . 
     A retaining hole  422   a  that retains the tip side of the pen shaft portion  411  of the pen  41  is formed in the pen retaining member  422 . The pen  41  is retained in the pen holder  42  by the tip side of the pen shaft portion  411  being inserted in the retaining hole  422   a  of the pen retaining member  422 . Note that screw grooves (not illustrated) may be formed in an outer circumferential surface of the tip side of the pen shaft portion  411 , screw grooves (not illustrated) capable of mating with the screw grooves of the shaft portion may be formed in an inner circumferential surface of the retaining hole  422   a , and the pen  41  may be retained in the retaining hole  422   a  by screwing the screw grooves on the pen shaft portion  411  side into the screw grooves on the retaining hole  422   a  side. 
     In the present embodiment, two auxiliary rod members  423  are disposed so as to sandwich the pen  41 . A bottom end of each of the auxiliary rod members  423  is mated with the pen retaining member  422  and, thereby, the auxiliary rod members  423  are fixed so as to be parallel with the pen shaft portion  411  of the pen  41 . 
     A retaining protrusion  424  protruding in a direction away from the axial center of the pen  41  is provided on the auxiliary rod members  423 . 
     A coil spring  425  is wrapped around the rod of the auxiliary rod members  423 . The coil spring  425  is configured to apply force in an upward direction to the auxiliary rod member  423  in a state free of external forces and holds the position of the pen  41  when not drawing at a position where the pen tip  413  does not come into contact with the nail T. 
     A pen vertical motor  426  constituted by a stepping motor, a gear  428  that engages with a gear  427  attached to a rotating shaft of the pen vertical motor  426 , and a plate spring  429  that pivots along with the rotation of the gear  428  are provided in the vicinity of the pen holder  42 . 
     In the present embodiment, a lifting mechanism of the pen  41  is constituted by the pen vertical motor  426 , the gear  427 , the gear  428 , the plate spring  429 , and the like. 
     When not drawing, the plate spring  429  does not apply external forces to the retaining protrusion  424  and, in this state, the pen  41  is pushed in an upward direction (the upward direction in  FIGS. 1A and 2B ) by the biasing force of the coil spring  425 . Thus, the tip portion of the pen  41 , namely the pen tip  413 , is separated from the drawing object surface, namely the surface of the nail T, and held at a height where the pen tip  413  does not come into contact with the surface. 
     On the other hand, when drawing, the pen vertical motor  426  rotates a prescribed number of steps, resulting in the plate spring  429  pivoting. At this time, the plate spring  429  engages with the retaining protrusion  424  provided on the auxiliary rod member  423  and presses the retaining protrusion  424  downward. 
     Thus, the pen  41  is pressed downward against the biasing force of the coil spring  425 , and the pen tip  413  comes into contact with the surface of the nail T. 
     The plate spring  429  flexes a suitable degree and, as a result, impact caused by the vertical movement of the pen  41  is absorbed by the plate spring  429  and the pen  41  moves vertically along with the height of the nail T while maintaining a suitable degree of pen pressure of the pen tip  413  in a roughly constant manner. Thus, the desired nail design can be drawn neatly on the surface of the drawing object, namely the nail T. 
     The unit supporting member  44  is fixed to an X-direction movement portion  451  that is attached to the X-direction movement stage  45 . 
     The X-direction movement portion  451  is configured to move in the X direction along guides (not illustrated) on the X-direction movement stage  45  via the driving of the X-direction movement motor  46 . Thus, the drawing head  43  that is attached to the unit supporting member  44  is configured to move in the X direction (the X direction in  FIG. 1A  and the left-right direction of the nail printing apparatus  1 ). 
     The X-direction movement stage  45  is fixed to a Y-direction movement portion  471  of the Y-direction movement stage  47 . The Y-direction movement portion  471  is configured to move on the Y-direction movement stage  47  in the Y direction along a guide (not illustrated) via the driving of the Y-direction movement motor  48 . Thus, the drawing head  43  that is attached to the unit supporting member  44  is configured to move in the Y direction (the Y direction in  FIG. 1B  and the front-back direction of the nail printing apparatus  1 ). 
     Note that in the present embodiment, the X-direction movement stage  45  and the Y-direction movement stage  47  are configured from combinations of the X-direction movement motor  46 , the Y-direction movement motor  48 , and ball screws and guides (not illustrated). 
     In the present embodiment, a head movement portion  49  is configured as an XY drive unit that drives the drawing head  43  provided with the pen  41  in the X direction and the Y direction via the X-direction movement motor  46 , the Y-direction movement motor  48 , and the like. 
     The pen vertical motor  426 , the ink jet drawing portion  71 , the X-direction movement motor  46 , and the Y-direction movement motor  48  of the drawing unit  40  are connected to a drawing control portion  815  of a control device  80  (see  FIG. 3 ; described hereinafter), and are configured to be controlled by the drawing control portion  815 . 
     An imaging unit  50  is provided with an image capturing device  51  and an illumination device  52 . 
     The imaging unit  50  illuminates the nail T of the print finger U 1 , which is inserted into the finger receiving portion  31  and is visible through the opening of the upper portion, using the illumination device  52 . 
     Moreover, the print finger U 1  is imaged using the image capturing device  51  and, a captured image of the nail T of the print finger U 1 , namely a nail image (image of finger including nail image) is acquired. 
     In the present embodiment, the image capturing device  51  and the illumination device  52  are fixed on a side (the left side of the drawing head  43  in  FIG. 1A ) of the drawing head  43  of the drawing unit  40 . 
     Specifically, as illustrated in  FIG. 2A , the drawing head  43  of the drawing unit  40  has an overhanging portion  401  overhanging in a lateral direction from a first edge (the left side in  FIG. 2A ) of the top surface of the drawing head  43 , and a substrate  53  is attached to the overhanging portion  401 . 
     The image capturing device  51  and the illumination device  52  constituting the imaging unit  50  are provided on a bottom surface of the substrate  53  so as to face the dividing wall  116 . 
     Note that a size of the substrate  53  and positions where the image capturing device  51  and the illumination device  52  are attached to the substrate  53  are not particularly limited. 
     The image capturing device  51  is, for example, a small camera having a solid state image sensor with a pixel count of about 2 million pixels or greater, a lens, and the like. 
     In the present embodiment, a nail shape detection portion  812  (see  FIG. 3 ) detects an actual outline La (see  FIG. 4A ) indicating the actual shape of the outer periphery of the nail T, on the basis of the captured images (the nail images) acquired by the image capturing apparatus  51 . 
     The nail shape detection portion  812  detects a position of the nail T on the X-Y plane, a vertical position of the nail T, and other nail information on the basis of the captured images (the nail images). 
     Note that the image capturing device  51  is preferably configured to be moved by the head movement portion  49  so as to image the nail T from differing positions or angles and acquire a plurality of captured images (nail images) and, thereby, detect the curvature and the like of the nail T of the print finger U 1 . 
     In cases where the image capturing device  51  acquires a plurality of captured images (nail images), the nail shape detection portion  812  (see  FIG. 3 ) can detect the curvature of the nail T on the basis of these captured images (nail images). 
     The illumination device  52  is, for example, a white LED or similar light source. 
     In the present embodiment, the illumination device  52  is disposed beside the image capturing device  51  (on the left side of the image capturing device  51  in  FIGS. 1A and 2A ). 
     The illumination device  52  radiates light downward and illuminates at least an imaging area below the image capturing device  51 . 
     The position of the illumination device  52  with respect to the image capturing device  51  is fixed. Note that the disposal and number of the illumination devices  52  provided is not limited to the illustrated examples. 
     The imaging unit  50  is connected to an imaging control portion  811  of the control device  80  (described hereinafter, see  FIG. 3 ), and is configured to be controlled by the imaging control portion  811 . 
     Note that image data of the image imaged by the imaging unit  50  is stored in a nail image memory region  821  of a memory unit  82  (described hereinafter). 
     The control device  80  is, for example, arranged on a substrate  13  or the like disposed in the upper frame  12 . 
       FIG. 3  is a main constituent block diagram showing the control configuration according to the present embodiment. 
     As illustrated in  FIG. 3 , the control device  80  is a computer provided with a control unit (processor)  81  constituted by a central processing unit (CPU) (not illustrated), and a memory unit  82  constituted by a read only memory (ROM), a random access memory (RAM), or the like (neither illustrated). 
     Various programs to operate the nail printing apparatus  1 , various data, and the like are stored in the memory unit  82 . 
     Specifically, various programs are stored in the ROM of the memory unit  82  such as an actual outline detection program for detecting an actual outline indicating the actual shape of the outer periphery of the nail T from the nail images (the captured images); an interpolation outline creation program for creating an interpolation outline of the nail T from the nail images (the captured images); a nail information detection program for detecting various types of nail information such as curvature in the width direction of the nail T, the width of the nail T, and the area of the nail T; a damaged portion determination program for determining whether or not the nail T has a damaged portion; a drawing data generation program for generating drawing data; and a drawing program for performing drawing processing. A configuration is provided whereby these programs are executed by the control device  80  and, thus, the components of the nail printing apparatus  1  are controlled in an integrated manner. 
     In the present embodiment, the memory unit  82  is provided with the nail image memory region  821  where the nail image (captured image) of the nail T of the print finger U 1  of a user acquired by the imaging unit  50  is stored, a nail information memory region  822  where the nail information detected by the nail shape detection portion  812  (the actual outline indicating the actual shape of the outer periphery of the nail T, the curvature of the nail T, and the like) and the interpolation outline of the nail T created by the damaged portion determination portion  813  are stored, a nail design memory region  823  where image data of a nail design to be drawn on the nail T is stored, and the like. 
     When viewed from a function perspective, the control unit  81  is provided with the imaging control portion  811 , the nail shape detection portion  812 , the damaged portion determination portion  813 , a drawing data generation portion  814 , the drawing control portion  815 , a display control portion  816 , and the like. Functions of the imaging control portion  811 , the nail shape detection portion  812 , the damaged portion determination portion  813 , the drawing data generation portion  814 , the drawing control portion  815 , the display control portion  816 , and the like are realized by cooperation of the CPU of the control unit  81  and the programs stored in the ROM of the memory unit  82 . 
     The imaging control portion  811  is configured to cause the image capturing device  51  to image finger images, that is, nail images (captured images) including images of the nail T of the print finger U 1  inserted into the finger receiving portion  31 , by controlling the image capturing device  51  and the illumination device  52  of the imaging unit  50 . 
     In the present embodiment, while the imaging device  50  is moved by the drawing control portion  815  that controls the head movement portion  49 , the imaging control portion  811  causes the image capturing apparatus  51  to image the nail T from a plurality of positions or angles in the width direction of the nail T (e.g. directly above the nail T and diagonally above the nail T, or the like), and acquire a plurality of the nail images (captured images). 
     Note that the number of captured images acquired for one nail T is not particularly limited, but it is preferable that two or more captured images be acquired from different positions in the width direction of the nail T because it will be possible to perform accurate detection, including the detection of the curvature of the nail T. 
     The image data of the nail image acquired by the imaging unit  50  is stored in the nail image memory region  821  of the memory unit  82 . 
     The nail shape detection portion  812  is configured to detect the nail information on the nail T of the print finger U 1  on the basis of the images (captured images) of the nail T of the print finger U 1  inserted into the finger receiving portion  31 , the image being imaged by the image capturing device  51 . 
     In the present embodiment, the nail shape detection portion  812  detects the actual outline La (depicted as a solid line in  FIG. 4A ) indicating the actual shape of the outer periphery of the nail T as the nail information, on the basis of the captured images. 
     For example, in cases where the nail T has chipped portions, cracks, or the like, such portions appear as irregularities, and these irregularities are included in the actual outline La, which is an outline indicating the actual shape of the outer periphery of the nail area. 
     The technique whereby the actual outline La of the nail T is detected is not particularly limited. For example, the actual outline La can be detected by edge detection processing or similar image processing. 
     Note that the nail information acquired by the nail shape detection portion  812  is not limited to the actual outline La. For example, the nail information may include the X-Y coordinates of the horizontal position of the nail T, the height of the nail T (position in the vertical direction of the nail T, hereinafter referred to as the “vertical position of the nail T” or simply the “position of the nail T”), the shape in the width direction of the nail T, that is, the inclination angle with respect to the X-Y plane of the surface of the nail T (the curvature of the nail T or the inclination angle of the nail T), and the like. 
     The nail information acquired by the nail shape detection portion  812  is stored in the nail information memory region  822  of the memory unit  82 . 
     The damaged portion determination portion  813  creates an interpolation outline Lb of the nail T (depicted by dotted lines in  FIG. 4A ) from the images (the captured images) of the nail T of the print finger U 1  inserted into the finger receiving portion  31 , imaged by the image capturing apparatus  51 . 
     The interpolation outline Lb is an outline generated by interpolating such that the actual outline of the outer periphery of the nail T, at portions other than the root side (the growing side) of the nail T, has a smooth shape. For example, in cases where the nail T has a concavity in a portion of the actual outline, the interpolation outline Lb is an outline generated by interpolating the actual outline so as to eliminate the concavity. 
     Specifically, the interpolated outline Lb is generated by providing a plurality of points on the actual outline of the outer periphery of the nail T, extracted by the nail shape detection portion  812 , in the portions other than the root side of the nail T, and interpolating so as to smoothly connect between this plurality of points on the outline. Thus, the interpolated outline Lb is similar to the natural outline of the nail T. 
     Note that the technique whereby interpolating between the plurality of points is carried out is not particularly limited. For example, a technique such as linear interpolation, polynomial interpolation, or cubic spline interpolation may be used as the technique for interpolating between the plurality of points. 
     Note that the interpolation outline Lb is generated in cases of both where a concavity exists and where a concavity does not exist in the actual outline of the nail T. Moreover, in cases where a concavity does not exist in the actual outline of the nail T, the interpolation outline Lb is the same or is substantially the same as the actual outline La. 
     Upon creation of the interpolation outline Lb, the damaged portion determination portion  813  compares the created interpolation outline Lb with the actual outline La detected by the nail shape detection portion  812  and, as a result, determines whether or not the nail T has a damaged portion Ba (see  FIG. 4A ). 
     Next, a detailed description is given regarding the determination by the damaged portion determination portion  813  of whether or not the nail has the damaged portion Ba. 
     A normal nail T without chips or cracks is free of irregularities in the outline and the outline forms a smooth, curved line. On the other hand, a nail T with chips or cracks has irregularities in the outline thereof. 
     As such, the damaged portion determination portion  813  determines whether or not the nail T has the damaged portion Ba by comparing the interpolation outline Lb of the nail T with the outline indicating the actual shape of the nail area, namely the actual outline La, and detecting a difference therebetween. 
     That is, in cases where the nail T does not have chips and cracks, the entire actual outline La will be smooth and when compared with the interpolation outline Lb, hardly any differences will appear. 
     In contrast, in cases where the nail T has chips or cracks, irregularities will appear in the actual outline La, but the irregularities corresponding to the chips and cracks will nearly disappear in the interpolation outline Lb in which the outline is smoothly interpolated. As a result, when comparing the actual outline La with the interpolation outline Lb, a difference will appear. 
     When the damaged portion determination portion  813  of the present embodiment detects a difference, first, it is determined whether or not a value of the area of the difference portion S (see  FIGS. 4A and 4B ) is greater than or equal to a preset threshold. 
     Then, in cases where the value of the area of the difference portion S is greater than or equal to the preset threshold, whether or not the nail T has the damaged portion Ba is determined while taking into consideration a value obtained by dividing the circumferential length of the difference portion S by the value of the area of the difference portion S. 
     Here, the pen  41  performs the drawing in a state of contact with the surface of the nail T. As such, in cases where the nail T has a chip, a crack, or the like, and drawing is attempted at that location, the pen tip  413  may catch or get stuck at the chipped portion. 
     Especially, in cases where the pen  41  has a ballpoint pen tip  413 , as is anticipated in the present embodiment, moving the pen  41  while the pen tip  413  is caught at the chipped portion may result in an injury to the user such as the caught pen tip  413  cracking the nail T even further or peeling the nail T off. 
     Here, in cases where the portion where chipping or cracking has occurred is smaller than the diameter of the pen tip  413 , there is little possibility of the pen tip  413  becoming caught or stuck at the chipped portion. Accordingly, in these cases, there is no obstacle to performing the drawing processing as-is. 
     As such, the threshold of the value of the area is preferably the same or slightly greater than a value of the area of the pen tip  413  of the pen  41 . For example, when a ball diameter of the pen tip  413  of the ballpoint pen  41  is approximately 1 mm, the threshold of the value of the area is set, for example, to 1 mm 2 . 
     Note that the size of the chipped portion where there is a possibility of the pen tip  413  catching or stuck differs depending on the size, structure, material quality, and the like of the pen tip  413  of the pen  41 . As such, the threshold of the value of the area is preferably set appropriately in accordance with the size, structure, material quality, and the like of the pen tip  413  of the pen  41  used in the drawing. 
     Note that even if the area of the difference portion S is large, provided that the difference portion S has a comparatively gentle shape along the outer edge of the nail T, there is little possibility of the pen tip  413  becoming caught or stuck at the chipped portion. As such, in these cases, there is no obstacle to performing the drawing processing as-is. 
     Thus, to appropriately determine whether or not a damaged portion Ba exists that presents a danger when performing the drawing processing, it is preferable that the shape of the chipped portion be considered in addition to the area of the difference portion S. 
     For example, when two difference portions S are compared and the areas of both are approximately the same, it can be determined that the difference portion S with the longer circumferential length has a narrow, gentle shape. 
     As such, in the present embodiment, in cases where the detected difference portion S has an area greater than or equal to a certain area and the value obtained by dividing the circumferential length of the difference portion by the value of the area of the difference portion satisfies a certain condition (that is, in cases where the value obtained by dividing the circumferential length of the difference portion S by the area of the difference portion S is smaller than a predetermined value), the damaged portion determination portion  813  determines that the nail T has a damaged portion Ba that is an obstacle to drawing. 
     Here, the predetermined value is appropriately set to a value at which it can be said that the shape is gentle to a degree that catching does not easily occur, in accordance with type of the pen  41 , the shape of the pen tip  413 , and the like. 
     Thus, even if the difference portion S exists, it is determined that the damaged portion Ba does not exist when the certain condition is not satisfied. As such, it is possible to perform the drawing processing in cases where there are simply fine irregularities and cracks that do not pose an obstacle to drawing. 
     Note that in cases where a plurality of difference portions S is detected, the damaged portion determination portion  813  determines whether or not each of the difference portions constitutes a damaged portion Ba for all of the difference portions S, on the basis of the standards described above. Then, in cases where it is determined that none of the difference portions S constitute a damaged portion Ba, it is determined that the damaged portion Ba does not exist. 
     In cases where it is determined by the damaged portion determination portion  813  that the nail T has the damaged portion Ba, the display unit  26 , for example, is caused to display a message or the like to that effect. As a result, the user is informed of the existence of the damaged portion Ba that poses a danger to the performance of the drawing processing. 
     In these cases, the display unit  26  functions as notification unit for informing a user of the existence of the damaged portion Ba. 
     Note that the notification unit is not limited to the display unit  26 . For example, a speaker or similar audio output unit may be provided as the notification unit, and the user may be audibly informed of the existence of the damaged portion Ba. The user may be informed of the existence of the damaged portion Ba both visually and audibly. 
     In the present embodiment, in cases where it is determined that the damaged portion Ba exists, subsequent drawing processing is canceled. 
     The drawing data generation portion  814  generates drawing data for the drawing to be performed by the drawing head  43  to the nail T of the print finger U 1  on the basis of the nail information detected by the nail shape detection portion  813 . 
     Specifically, on the basis of the shape of the nail T (the actual outline La) and the like detected by the nail shape detection portion  812 , the drawing data generation portion  814  performs calibration processing, such as enlarging, reducing, and cropping, for calibrating the image data of the nail design to the shape of the nail T. 
     The drawing data generation portion  814  functions as an image data correction portion that performs appropriate curvature correction on the image data of the nail design specified to be drawn on the nail T, in accordance with the curvature of the nail T detected by the nail shape detection portion  812 . 
     As a result, drawing data for the nail design to be drawn by the pen  41  or the ink jet drawing portion  71  is generated. 
     The drawing control portion  815  is a control portion that outputs control signals to the drawing unit  40  on the basis of the drawing data generated by the drawing data generation portion  814 , and controls the X-direction movement motor  46 , the Y-direction movement motor  48 , the pen vertical motor  426 , the ink jet drawing portion  71 , and the like of the drawing unit  40 , so as to perform a drawing on the nail T that corresponds with the drawing data. 
     Specifically, when the pen  41  is not drawing, the drawing control portion  815  controls the pen vertical motor  426  so as to maintain a state in which the retaining protrusion  424  is not pressed down by the plate spring  429 ; and, when the pen is drawing, the drawing control portion  815  causes the pen vertical motor  426  to operate and controls the operation of the pen vertical motor  426  so that the retaining protrusion  424  is pressed down by the plate spring  429  and the tip side (the pen tip  413 ) of the pen  41  comes into contact with the surface of the nail T. 
     Note that at locations where the height of the nail T changes greatly and cannot be accommodated by the flexible deformation (elastic deformation) of the plate spring  429  alone, the drawing control portion  815  preferably causes the number of steps of the pen vertical motor  426  to be increased or decreased, thus adjusting the pen pressure of the pen  41  so that the pen pressure becomes substantially constant. 
     The display control portion  816  is configured to control the display unit  26  and cause the display unit  26  to display various types of display screens. In the present embodiment, examples of the various types of display screens the display control portion  816  is configured to display on the display unit  26  include nail design selection screens and thumbnail images for confirming designs, nail images acquired by imaging the print finger U 1 , various command screens, operation screens, and the like. 
     In the present embodiment, as described above, a configuration is provided in which the display unit  26  is caused to function as notification unit for informing a user of the existence of the damaged portion Ba and, in cases where it is determined by the damaged portion determination portion  813  that the nail T has the damaged portion Ba, the display control portion  816  causes the display unit  26  to display a message or the like to that effect. 
     Next, a damaged portion detection method and a drawing method by the nail printing apparatus  1  according to the present embodiment are described while referencing  FIG. 5 . 
     In cases where performing drawing using the nail printing apparatus  1 , a user first operates a power switch to turn on the control device  80 . 
     The display control portion  816  causes a design selection screen to be displayed on the display unit  26 , and the user operates operation buttons or the like on the operation unit  25  and selects a desired nail design from among a plurality of nail designs displayed on the design selection screen. As a result, a selection command signal is output from the operation unit  25  and the nail design intended to be drawn on the nail T is selected. 
     Next, as shown in  FIG. 5 , the display control portion  816  causes the display unit  26  to display a command screen prompting that the print finger U 1  be set in the finger receiving portion  31  (step S 1 ). 
     The user operates a drawing switch (not illustrated) of the operation unit  25  after inserting the print finger U 1  into the finger receiving portion  31 , inserting the non-print fingers U 2  into the finger clearing portion  32 , and securing the print finger U 1  to the finger receiving portion  31 . 
     Upon input of a command from the draw switch and before starting the drawing operations, first, the drawing control portion  815  controls the head movement portion  49  and causes the imaging unit  50  to move to a predetermined imaging position (step S 2 ). 
     For example, in cases where imaging from directly above the nail T, the head movement portion  49  is controlled so as to move the imaging unit  50  directly above the nail T. 
     Then, the imaging control portion  811  controls the imaging unit  50  and causes the image capturing device  51  to image the print finger U 1  while illuminating the print finger U 1  using the illumination device  52 . 
     As a result, the imaging control portion  811  acquires a captured image (nail image) of the nail T of the print finger U 1  that has been inserted into the finger receiving portion  31  (step S 3 ). 
     Note that in cases where a plurality of captured images is acquired at different positions, the imaging unit  50  is appropriately moved by the head movement portion  49  and imaging is performed. 
     Upon acquisition of the captured images (the nail images), the nail shape detection portion  812  detects the actual shape of the outline of the nail T, namely the actual outline La, on the basis of the nail images (the captured images) (step S 4 ). 
     The nail shape detection portion  812  detects the curvature of the nail T and other nail information on the basis of the nail images (the captured images). 
     Next, the damaged portion determination portion  813  creates the interpolation outline Lb of the nail T on the basis of the nail images (the captured images) (step S 5 ). 
     Then, the damaged portion determination portion  813  compares the created interpolation outline Lb with the actual outline La of the nail T detected by the nail shape detection portion  812  and determines whether or not there is a difference therebetween (step S 6 ). 
     Then, in cases where there is a difference therebetween (step S 6 ; YES), the damaged portion determination portion  813  further calculates the area of the difference portion S and determines whether or not the area is greater than or equal to a certain area (e.g. 1 mm 2  or greater) (step S 7 ). 
     In cases where the area of the difference portion S is greater than or equal to the certain area (step S 7 ; YES), the damaged portion determination portion  813  further detects the circumferential length of the difference portion S (step S 8 ) and determines whether or not the value obtained by dividing the circumferential length of the difference portion S by the area of the difference portion S satisfies the predetermined condition (step S 9 ). That is, in cases where circumferential length/area&lt;predetermined value, the damaged portion determination portion  813  determines that the predetermined condition is satisfied. 
     Then, in cases where the value obtained by dividing the circumferential length of the difference portion S by the area of the difference portion S satisfies the predetermined condition (step S 9 ; YES), the damaged portion determination portion  813  determines that the difference portion S is the damaged portion Ba and determines that the nail T has the damaged portion Ba (step S 10 ). 
     In these cases, the display control portion  816  causes the display unit  26  to display an alert indicating the existence of the damaged portion Ba, and the control unit  81  cancels the drawing processing (step S 11 ). 
     On the other hand, (1) in cases where there is no difference between the interpolation outline Lb and the actual outline La (step S 6 ; NO), (2) in cases where there is a difference portion but the area of the difference portion S is smaller than the certain area (step S 7 ; NO), and (3) in cases where the area of the difference portion S is greater than or equal to the certain area but the value obtained by dividing the circumferential length of the difference portion S by the value of the area of the difference portion S does not satisfy the predetermined condition (step S 9 ; NO), the damaged portion determination portion  813  determines that the difference portion S is not the damaged portion Ba and that the nail T does not have the damaged portion Ba (step S 12 ). 
     Then, in these cases, drawing processing for drawing the nail design selected by the user on the nail T is performed by the drawing unit  40  (step S 13 ). 
     Specifically, the drawing data of the nail design is generated by the drawing data generation portion  814 , the drawing control portion  815  outputs the drawing data to the drawing unit  40 , and the drawing is performed on the nail T by the pen  41  or the ink jet drawing portion  71  while the drawing control portion  815  operates the head movement portion  49  and causes the drawing head  43  to move appropriately. 
     Note that in cases where a plurality of the difference portions S is detected in step S 6 , the processing of step S 7  to step S 9  is repeated for each of the difference portions S. As a result, in cases where even one of the plurality of difference portions S is determined to be the damaged portion Ba, step S 10  is carried out and it is determined that the nail T has the damaged portion Ba, the display unit  26  is caused to display the alert, and the drawing processing is canceled. 
     As described above, according to the present embodiment, the actual shape of the outline of the nail T, namely the actual outline La, is detected and the interpolation outline Lb of the nail T is created from the captured images of the nail T; and the actual outline La and the interpolation outline Lb are compared to each other. As a result, it is determined whether or not the nail T has the damaged portion Ba. 
     As such, in cases where the nail T has cracks or chips, these can be detected as the damaged portion Ba and the condition of the drawing object, namely the nail T, can be determined. Thus, the drawing processing can be safely performed. 
     When drawing is performed on a nail T that has the damaged portion Ba, often the nail design does not turn out as expected. However, by determining the presence or absence of the damaged portion Ba, such as in the present embodiment, the finish of the nail design can be secured and a certain degree of drawing quality can be ensured. 
     In the present embodiment, in cases where the interpolation outline Lb and the actual outline La are compared to each other, the difference therebetween is detected, and the detected difference portion S is greater than or equal to the certain area, the value obtained by dividing the circumferential length of the difference portion S by the value of the area of the difference portion S is taken into consideration and it is determined whether or not the nail T has the damaged portion Ba. 
     In these cases, provided that only fine chips and cracks have occurred, there is no obstacle to performing the drawing. As such, instead of only considering the area of the difference portion S, the value obtained by dividing the circumferential length of the difference portion by the value of the area of the difference portion is also taken into consideration. As a result, the determination of the presence or absence of the damaged portion Ba is performed while taking both the size and the shape of the difference portion S into consideration. As such, situations can be avoided where it is unnecessarily determined that the damaged portion Ba exists and drawing cannot be performed. 
     In the present embodiment, a configuration is provided in which in cases where it is determined by the damaged portion determination portion  813  that the nail T has the damaged portion Ba, the display unit  26  is caused to display a notification to that effect and notify (alert) the user. As a result, the user can know that the nail T is in a dangerous condition where injury may result if drawing is performed. Thus, the user can appropriately deal with the situation by, for example, filing the chipped portion of the nail to shape the nail. 
     The embodiment described above is for the purpose of elucidating the present invention and is not to be construed as limiting the present invention. The invention can of course be altered and improved without departing from the gist thereof. 
     For example, the damaged portion determination portion  813  may be configured to compare the actual outline La and the interpolation outline Lb of the nail T and, if there is a difference therebetween, determine that the damaged portion Ba exists. 
     A difference will appear when comparing with the interpolation outline Lb if there are irregularities in the outline of the nail T and, as such, in cases where such a determination is performed, the portion with the irregularities can be widely detected as the damaged portion Ba. 
     For example, the damaged portion determination portion  813  may be configured to compare the actual outline La with the interpolation outline Lb of the nail T and determine that the nail T has the damaged portion Ba in cases where there is a difference therebetween and the area of the detected difference portion S is greater than or equal to a certain area. 
     In cases where the area of the difference portion S is great to a certain degree, the pen tip  413  of the pen  41  will easily catch on the chipped portion and, often, the nail design does not turn out as expected. 
     As such, in cases where the difference portion S has such a large area, by determining that the damaged portion Ba exists without considering the shape of the difference portion S, the safety of the drawing processing can be ensured, the finish of the nail design can be secured, and a certain degree of drawing quality can be ensured. 
     In the present embodiment, an example is given of a case in which the processing of step S 7  and on is performed in cases where the difference portion S is detected by the damaged portion determination portion  813  in step S 6  of  FIG. 5 , regardless of the location of the difference portion S. However, in cases where the damaged portion Ba is not included in the area of the nail T where the pen  41  is expected to draw (the drawing object area), the pen tip  413  of the pen  41  will not catch on the damaged portion Ba and there is no especial danger. 
     As such, a configuration is possible in which the notification to the user, the cancellation of the drawing, or similar processing is performed only in cases where the damaged portion Ba is located within the drawing object area of the nail T for the nail design selected by the user. 
     In this case, if the damaged portion determination portion  813  detects a difference portion S caused by a chip or the like, the damaged portion determination portion  813  determines whether or not the difference portion S is located within the drawing object area of the nail T for the nail design selected by the user. In cases where the difference portion S is located outside the drawing object area, the drawing processing is performed as-is. In contrast, the processing of step S 7  and on is performed only when it is determined that the difference portion S is located within the drawing object area. 
     In the present embodiment, an example is given of a case in which, in cases where it is determined by the damaged portion determination portion  813  that the nail T has the damaged portion Ba, measures are taken in which the user is informed to that effect, and the drawing processing is canceled. However, the measures taken when it is determined that the damaged portion Ba exists are not limited thereto. 
     For example, a configuration is possible in which, in cases where it is determined by the damaged portion determination portion  813  that the nail T has the damaged portion Ba, the drawing data of the nail design is corrected in the drawing data generation portion  814  such that drawing is performed while avoiding the damaged portion Ba. 
     For example, in cases such as that illustrated on the left side in  FIG. 6A  where a nail design D with a flower pattern drawn near the free end of the nail is selected, and the damaged portion Ba exists on the left side of the free end portion of the nail T, if the image data of the nail design D is calibrated as-is to the nail T, as illustrated on the right side of  FIG. 6A , a portion of the flower pattern will run onto the damaged portion Ba. 
     In such a case (that is, in a case where the damaged portion Ba is within the drawing object area), for example, as illustrated in  FIG. 6B , the image data is corrected such that the nail design D is lowered to a location where the nail design D does not run onto the damaged portion Ba. As a result, the possibility of the pen tip  413  catching on the damaged portion Ba is eliminated and the desired nail design can be safely drawn. 
     Likewise, the possibility of the pen tip  413  catching on the damaged portion Ba can be avoided and the desired nail design D can be safely drawn by, for example, shrinking or deforming the nail design D a degree at which the drawing object area does not run onto the damaged portion Ba. 
     Note that in cases where taking measures by correcting or modifying the drawing data of the nail design as described above, the display unit  26  or the like may be caused to display an expected finish of a case where the drawing is performed on the basis of the corrected or modified drawing data, and the user may be requested to select whether or not to perform the drawing processing using the corrected drawing data. 
     For example, in cases where image data of a plurality of types of nail designs is stored in the nail design memory region  823 , a configuration is possible in which the display unit  26  is caused to display the nail designs that can be drawn while avoiding the damaged portion Ba in cases where it is determined by the damaged portion determination portion  813  that the nail T has the damaged portion Ba. 
     In this case, for example, when the nail T has the damaged portion Ba in the middle of the free end portion, the display unit  26  or the like is caused to display the nail designs that do not include the damaged portion Ba within the drawing object area and present these nail designs to the user. Examples of such nail designs include those in which single point patterns are drawn in the middle portion of the nail T. 
     In this case, the display unit  26  functions as design presentation means for presenting nail designs to a user. 
     Then, the user re-selects a nail design from among those displayed on the display unit  26  and, thereby, drawing processing is performed for the selected nail design. 
     In this case, the user can freely select from among nail designs that match the condition of the nail T, and a nail design matching the preferences of the user can be safely drawn. 
     Note that the measures such as those described above taken in cases where it is determined, by the damaged portion determination portion  813  that the nail T has the damaged portion Ba, may be selectable by a user. 
     That is, in cases where informing by causing the display unit  26  to display that the damaged portion Ba exists, a configuration is possible in which the user can select from the operation unit  25  or the like whether to finish as-is without performing the drawing processing, correct or modify the selected nail design to a drawable state, or cause the display unit  26  or other design presentation means to present other drawable nail designs and re-select the nail design; and perform processing in accordance with the selection. 
     In the present embodiment, an example is given of a case in which, in cases where the nail T has the difference portion S, the damaged portion determination portion  813  determines whether the difference portion S constitutes the damaged portion Ba on the basis of the area thereof and the value obtained by dividing the circumferential length by the value of the area. However, the technique and determination standard for determining whether or not the difference portion S corresponds to the damaged portion Ba, and the factors used in the determination are not limited to the examples described in the present embodiment, and any are possible provided that they are suitable to enable the determination of whether or not the difference portion S is of a level where problems will not occur such as the pen tip  413  catching or the like when performing drawing by the pen  41 . 
     In the present embodiment, a configuration has been described in which the drawing head  43  of the nail printing apparatus (the drawing apparatus)  1  is provided with the pen holder  42  that holds the pen  41  for drawing and also the ink jet drawing portion  71 . However, the drawing apparatus may have a configuration in which the ink jet drawing portion  71  is not provided and the drawing is performed by only the pen  41 . 
     In the present embodiment, an example has been given of a case where the drawing head  43  is provided with one pen holder  42 . However, the number of the pen holders  42  provided in the drawing head  43  is not limited to one. For example, a configuration is possible in which two or more pen holders  42  are provided and two or more pens  41  for drawing are held. 
     In the present embodiment, an example has been given of a case where a user manually replaces the pen  41  held by the pen holder  42  as necessary. However, a configuration is possible in which a waiting space is provided where the pens  41  stand by in a home area  60  or the like, and the required pen  41  is automatically acquired from the waiting space and inserted into the pen holder  42  by a pen replacing mechanism (not illustrated). 
     In the present embodiment, an example has been given of a case where the image capturing apparatus  51  and the illumination device  52  are mounted to the drawing head  43 . However, the positions at which the image capturing apparatus  51  and the illumination device  52  are provided are not limited thereto. For example, a mechanism for moving the imaging unit  50  may be provided separately from the mechanism for moving the drawing head  43 . 
     In the present embodiment, an example has been given of the nail printing apparatus  1  in which fingers are inserted into the apparatus one finger at a time and drawing is performed sequentially. However, a configuration is also possible in which consecutive drawing can be performed on a plurality of fingers, without the need to insert and remove each finger. 
     The embodiment described above is not to be construed as limiting the scope of the present invention and include the scope of the invention recited in the claims and equivalents.