Drawing apparatus and method for acquiring inclination of nail

A drawing apparatus includes a mounting section where an object having a nail is mounted, and an inclination detection unit that detects a degree of an inclination of the nail in a width direction of the nail with respect to a reference state of the nail based on a shape of at least one target image along the width direction of the object, the target image being formed on the object.

CROSS-REFERENCE TO RELATED APPLICATIONS

A corresponding Japanese application is:

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a drawing apparatus and a method for detecting the inclination of a nail in the drawing apparatus.

2. Description of the Related Art

A drawing apparatus that draws a nail design on a nail has conventionally been known. Such a drawing apparatus is described in, for example, JP 2003-534083 T. The use of such a drawing apparatus makes it possible to enjoy a nail design easily without going to a nail salon or the like.

A drawing apparatus for nail printing has a structure where a finger having a nail on which a nail design is intended to be drawn is inserted into the drawing apparatus. Here, a sheet of paper and the like that are a normal printer's drawing targets do not incline normally. However, in such a drawing apparatus for nail printing, for example, the finger inserted in the drawing apparatus may rotate about an axis in the finger's extending direction to make the nail of the finger inclined with respect to a proper state that the nail is not inclined, with respect to the width direction. When the nail is inclined in this manner, if the nail design is drawn on the nail as it is without being aware of the inclined nail, the design drawn on the nail may be lopsided or distorted and its finish may not look beautiful.

Hence, when the nail is rotated about the axis of the finger extending direction and is inclined, it is preferable to take steps of, for example, correcting drawing data in accordance with the state of the inclination of the nail and then drawing, or prompting a user to stop the drawing operation, reset the finger, and try not to incline the nail.

The drawing apparatus for nail printing conventionally has a configuration to take a picture of a nail from above and has a configuration to detect the outline of the nail from the picture obtained by imaging. However, it is difficult to accurately detect the degree of the inclination of the nail, the inclination having been caused by the rotation about the axis in the finger's extending direction, in the picture imaged in this manner.

BRIEF SUMMARY OF THE INVENTION

The present invention has an advantage that can provide a drawing apparatus and method for detecting the inclination of a nail that can detect the degree of the inclination of the nail with accuracy with a relatively simple configuration and accordingly can draw excellently on the nail.

According to an embodiment of the present invention, there is provided a drawing apparatus including: a mounting section where an object is mounted, the object being a finger or a toe having a nail; and an inclination detection unit configured to detect a degree of an inclination of the nail in a width direction of the nail with respect to a reference state of the nail based on a shape of at least one target image along the width direction of the object, the target image being formed on the object mounted on the mounting section.

According to an embodiment of the present invention, there is provided a method for detecting inclination of a nail in a drawing apparatus, wherein the drawing apparatus includes a mounting section where an object is mounted, the object being a finger or a toe having the nail, the method including: an inclination detection step of detecting a degree of an inclination of the nail in a width direction of the nail with respect to a reference state of the nail based on a shape of at least one target image along the width direction of the object, the target image being formed on the object mounted on the mounting section along the width direction.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of a drawing apparatus and a method for detecting the inclination of a nail in the drawing apparatus according to the present invention is described in detail hereinafter with reference to the drawings.

The scope of the invention is not limited to the illustrated examples.

In the following embodiment, a description is given assuming that the drawing apparatus draws on a fingernail of the hand setting the fingernail as a drawing target. However, the drawing target of the present invention is not limited to the fingernail of the hand. For example, a toenail of the foot may be targeted for drawing.

FIG. 1is a front view of the drawing apparatus.

FIG. 2is a side view illustrating, in cross section, an internal configuration of part of the drawing apparatus illustrated inFIG. 1.

As illustrated inFIGS. 1 and 2, a drawing apparatus1is a hybrid nail printing apparatus including a drawing head41that ejects a drawing material such as ink to draw, and a drawing tool71configured of, for example, a writing instrument such as a pen to draw in contact with a drawing target while applying the drawing material such as ink. The drawing apparatus1includes a case body2, and an apparatus body10housed in the case body2. InFIGS. 1 and 2, the case body is indicated by a chain double-dashed line.

A drawing tool replacement purpose cover unit23configured to be openable/closable to replace the drawing tool71of a drawing unit40described below is provided at an upper end on a front surface of the case body2. The drawing tool replacement purpose cover unit23is pivotable on, for example, a hinge from a closed state to an open state as illustrated inFIG. 2.

Furthermore, a medium insertion/removal port24where a drawn medium to be mounted on a drawing tool break-in section61described below can be replaced is formed at a position on one side surface (a left side surface inFIG. 1in the embodiment) of the case body2, the position corresponding to the drawing tool break-in section61.

An operating unit25(seeFIG. 5) is installed on a top surface (top) of the case body2.

The operating unit25is an input unit that allows a user to perform various input operations.

Unillustrated operation buttons for performing various input operations, such as a power switch button to turn on the power to the drawing apparatus1, a stop switch button to stop the operation, a design selection button to select a design image to be drawn on a nail T, and a drawing start button to instruct the start of drawing, are placed on the operating unit25.

A display unit26is installed in a substantially central portion of the top surface (top) of the case body2.

The display unit26includes, for example, a liquid crystal display (LCD: Liquid Crystal Display), an organic electroluminescence display, or any other flat display.

In the embodiment, for example, a finger image (an image of a print finger U1including an image of the nail T) obtained by imaging the print finger U1, an image of the contour and the like of the nail T included in the finger image, a design selection screen for selecting a design image to be drawn on the nail T, a thumbnail image for a design check, and an instruction screen for displaying various instructions are displayed on the display unit26, as appropriate.

Especially in the embodiment, if it is determined that the inclination of the nail T exceeds an allowable range in an inclination detection unit812bby an evaluation value calculated by the inclination detection unit812b(seeFIG. 5) described below, it is designed to display a message, for example, to prompt the user to reset the finger, on a display screen of the display unit26.

The display unit26functions as a notification unit that notifies the user of a matter which the degree of the inclination of the nail T exceeds the allowable range when the degree of the inclination of the nail T exceeds the allowable range.

A touch panel may be integrally formed on the surface of the display unit26. In this case, various selections and instructions can be made by touching the surface of the touch panel with, for example, the finger tip. It is configured such that various input operations can also be performed by a touch operation of touching the surface of the display unit26with, for example, a stylus pen or pointed rod-like writing instrument other than the finger tip.

The apparatus body10includes a lower machine casing11formed into a substantially box shape and installed in a lower part inside the case body2, and an upper machine casing12installed above the lower machine casing11in an upper part inside the case body2.

The lower machine casing11includes a back plate111, a bottom plate112, a pair of left and right side plates113aand113b, an X-direction moving stage housing section114, a Y-direction moving stage housing section115, and a dividing wall116.

Lower ends of the side plates113aand113bare respectively coupled to both of left and right ends of the bottom plate112. The side plates113aand113bare provided in a standing manner with respect to the bottom plate112.

As illustrated inFIG. 2, a lower part of the back plate111is formed in such a manner as to be recessed toward the front (frontward in a finger insertion direction) in two stages.

A lower end of the back plate111is coupled to a front end of the bottom plate112. The back plate111partitions an area surrounded by the bottom plate112and the side plates113aand113binto front and back spaces.

The space formed behind the recessed back plate111serves as the X-direction moving stage housing section114and the Y-direction moving stage housing section115(seeFIG. 2).

An X-direction moving stage45of the drawing unit40is housed in the X-direction moving stage housing section114when the drawing unit40(seeFIG. 2) has moved to the front (frontward in the finger insertion direction).

A Y-direction moving stage47of the drawing unit40is placed in the Y-direction moving stage housing section115.

The dividing wall116is provided inside the lower machine casing11in such a manner as to partition the front space in the lower machine casing11(the frontward space in the finger insertion direction surrounded by the back plate111, the bottom plate112, and the side plates113aand113b) into upper and lower spaces.

The dividing wall116is provided substantially horizontally. Both of left and right ends of the dividing wall116are respectively coupled to the side plates113aand113b. A back end of the dividing wall116is coupled to the back plate111.

The lower machine casing11is integrally provided with a finger fixing section30.

The finger fixing section30is described with reference toFIG. 3.

FIG. 3is a main part cross-sectional view schematically illustrating the configuration of the finger fixing section30and its peripheral.

The finger fixing section30includes a finger receiving section31that receives a finger having the nail T being a drawing target on which drawing is performed (hereinafter referred to as the “print finger U1”), and a finger withdrawal section32that allows the fingers but the print finger U1, which are not the drawing target, (hereinafter referred to as the “non-print fingers U2”) to withdraw.

The finger receiving section31is placed in substantially the widthwise center of the lower machine casing11above the dividing wall116. The space partitioned by the dividing wall116as the lower side of the lower machine casing11forms the finger withdrawal section32.

For example, if drawing is performed on the nail T of the ring finger, the ring finger as the print finger U1is inserted into the finger receiving section31as illustrated inFIG. 3. The other four fingers (the thumb, index finger, middle finger, and little finger) being the non-print fingers U2are inserted into the finger withdrawal section32.

The finger receiving section31opens toward the front surface side of the lower machine casing11(frontward in the print finger insertion direction). A lower side of the finger receiving section31is partitioned by a finger mounting section116aforming a part of the dividing wall116, both sides thereof by a divider31a, and a back side thereof by a divider31c.

The finger mounting section116aincludes a mounting surface (X-Y plane)116con its upper surface. The finger (the print finger U1) having the nail T on which drawing is performed is mounted on the mounting surface116c.

An upper side of the finger receiving section31is partitioned by a ceiling section31d.

A window31ethrough which the nail T of the print finger U1inserted in the finger receiving section31is exposed is formed in the ceiling section31d.

A finger holding section33that holds, from below, the print finger U1inserted in the finger receiving section31is placed on the mounting surface116cof the finger mounting section116a.

The finger holding section33may be configured to be able to ascend and descend by an unillustrated mechanism. In this case, the finger holding section33is configured to descend to a height that does not interfere with putting in and taking out of the print finger U1when the print finger U1is inserted into the finger receiving section31or removed from the finger receiving section31, and to ascend in such a manner as to press the print finger U1up to a position where an upper surface of the print finger U1contacts an undersurface of the ceiling section31dwhen the print finger U1is fixed.

A nail mount base34protruding from the divider31cis provided in the finger receiving section31. It is designed such that the end portion of the nail T mounts onto the nail mount base34in a state where the print finger U1is being pressed up by the finger holding section33. Consequently, the height-wise position of the nail T is fixed at a constant position.

In the present invention, the finger holding section33and the nail mount base34are not always required in the drawing apparatus of the embodiment. The drawing apparatus1may be configured without them.

Front walls31f(seeFIG. 1) that block the front surface side of the lower machine casing11are provided in a standing manner on a top surface of the dividing wall116at both ends on the front surface side of the lower machine casing11.

A pair of guide walls31gthat narrows from one ends of the front walls31f, which are closer to the central portion, toward the finger receiving section31and guides the print finger U1into the finger receiving section31is provided in a standing manner on the top surface of the dividing wall116.

The user can sandwich the dividing wall116between the print finger U1inserted in the finger receiving section31and the non-print fingers U2inserted in the finger withdrawal section32. Hence, the print finger U1inserted in the finger receiving section31is stably fixed.

In the embodiment, a protrusion116bprotruding downward is formed at a front end of the dividing wall116.

The protrusion116bis, for example, a taper portion whose thickness gradually decreases toward the front side and gradually increases toward the back side. The protrusion116bmay have, for example, a shape that is thick as a whole as compared to a recess on a back side of the dividing wall116.

The protrusion116bis formed at the front end of the dividing wall116. Accordingly, when the non-print fingers U2have been inserted into the finger withdrawal section32, a space is secured between the already drawn nail T and an undersurface of the dividing wall116. Consequently, it is possible to prevent the drawing material, such as ink, that have been applied to the nail T, from attaching to the apparatus side and prevent the design drawn on the nail T from being smudged and marred, due to the contact of the already drawn nail T with the undersurface of the dividing wall116.

An area above the dividing wall116alongside the finger receiving section31(a position corresponding to the medium insertion/removal port24of the case body2, which is the left side inFIG. 1in the embodiment) is a home area where the drawing head41and the drawing tools71are on standby at the time of non-drawing).

The home area is provided with the drawing tool break-in section61, a drawing tool cap62, and a head cap mechanism43.

The drawing tool break-in section61is for breaking in the drawing tool71described below, and is placed within a drawable area of the drawing tool71.

A flat-plate like drawn medium inserted from the above-mentioned medium insertion/removal port24of the case body2is mounted on the drawing tool break-in section61being a flat-plate part.

The drawn medium to be mounted on the drawing tool break-in section61is simply required to be able to break in a nib712and is, for example, a slip of paper.

It is preferable that the drawn medium to be mounted on the drawing tool break-in section61be provided substantially as high as the nail T of the print finger U1inserted in the finger receiving section31.

In order to prevent the start of drawing from becoming patchy due to reasons such as the dry nib712and insufficient deposition of ink, the drawing tool break-in section61lowers the drawing tool71onto the drawn medium, draws a predetermined figure such as “o” or “∞”, breaks in the nib712, and makes the state of the nib712excellent before starting drawing on the nail T with image data.

The predetermined figure to be drawn upon breaking in is not especially limited. However, simple figures such as “o” and “∞” are preferable to prevent a waste of ink.

In breaking in, it is preferable to draw, shifting the position for drawing a figure such as “o” or “∞” bit by bit within an area of the drawing tool break-in section61for every break-in.

It is designed such that when drawing has been performed on the substantially entire surface of the drawn medium, a display screen that prompts the replacement of the drawn medium, such as “Please change paper,” is displayed on the display unit26.

In this case, the user removes the drawn medium from the medium insertion/removal port24to change it to new paper. Accordingly, it becomes possible to perform a break-in on the new drawn medium.

If the drawn medium is a roll of paper, when the drawing space is used up, the drawn medium is unreeled from the roll of paper to enable break-in on a new drawing surface.

The drawing tool cap62is for housing the drawing tool71(especially the nib712of the drawing tool71) when drawing is not performed (at the time of non-drawing) after the drawing tool71is attached to the drawing unit40. The drawing tool cap62is made of, for example, rubber.

In the embodiment, the drawing tool cap62is installed in the front of the drawing tool break-in section61(frontward in the finger insertion direction).

The drawing tool caps62are provided in such a manner as to be equal in number (four in the embodiment) to the drawing tools71that can be attached to the drawing unit40.

At the time of non-drawing, the drawing tool71is moved directly above the drawing tool cap62, and then lowered by a solenoid742described below to house the nib712in the drawing tool cap62. Consequently, the nib712can be prevented from becoming dry at the time of non-drawing.

The shape and the like of the drawing tool cap62are not limited to the unillustrated example. It may be, for example, an extra-long groove-shaped drawing tool cap that can receive the nibs712of all the drawing tools71attached to the drawing unit40.

In the embodiment, the drawing tool cap62is provided near the drawing tool break-in section61in this manner. Accordingly, upon starting drawing, the drawing tool71is raised for a break-in on the nearby drawing tool break-in section61. Drawing can be then started.

Hence, it is possible to keep the time taken to, for example, move the drawing tool71to a minimum, and to perform a speedy drawing operation.

The head cap mechanism43is for covering an ink ejection surface of the drawing head41at the time of non-drawing.

The head cap mechanism43is placed at a position above the dividing wall116, the position corresponding to a position where the drawing head41is placed when the drawing tools71are housed in the drawing tool caps62.

The head cap mechanism43is provided to cover the ejection surface of the drawing head41at the time of non-drawing. Accordingly, the drawing head41can be prevented from becoming dry at the time of non-drawing.

The drawing unit40uses a plurality of kinds of drawing materials such as inks to draw on the nail T based on the image data of a selected design image.

In the embodiment, the drawing unit40includes a carriage42in which the drawing head41, and a drawing tool unit72with the drawing tools71are mounted.

The carriage42is attached to a carriage support member44. Consequently, the drawing head41and the drawing tool unit72are supported by the carriage support member44via the carriage42.

The drawing unit40is configured including, for example, the X-direction moving stage45for moving the carriage42in the X direction (the X direction inFIG. 1, the left-and-right direction of the drawing apparatus1), an X-direction movement motor46, the Y-direction moving stage47for moving the carriage42in the Y direction (the Y direction inFIG. 2, the front-and-back direction of the drawing apparatus1), and a Y-direction movement motor48, in addition to the carriage42and the carriage support member44that supports the carriage42.

The drawing head41is an inkjet drawing tool that sprays a drawing material such as ink, which is a liquid material, to the nail T's surface being a drawing target surface, applies the ink to the nail T's surface, and draws.

The configuration and system in which the drawing head41sprays ink are not especially limited.

The drawing head41of the embodiment is, for example, an integral-type cartridge where an ink tank is integrated. A plurality of ink chambers (ink storage portions, not illustrated) partitioned separately is provided in the drawing head41. The ink chambers are respectively filled with, for example, inks of three colors, C, M, and Y, as the liquid materials. The kind and number of inks (liquid materials, drawing materials) are not limited to those illustrated herein.

The ejection surface (not illustrated) in which a nozzle to eject each color ink filled in the ink chamber is provided to a lower surface (a surface facing the finger mounting section116awhen the drawing head41is attached to the carriage42) of the drawing head41.

The drawing head41includes an ink ejection unit411for ejecting ink from the nozzle of the ejection surface. The ink ejection unit411includes, for example, a piezoelectric element (not illustrated) as an actuator.

The carriage42is provided with a head drive circuit board (not illustrated) that drives the drawing head41.

When the drawing head41is attached to the carriage42, a connector (not illustrated) on the drawing head41side is connected to the head drive circuit board. The ink ejection unit411is electrically connected to a control apparatus80via the head drive circuit board.

Consequently, a driving voltage is applied to the piezoelectric element forming the ink ejection unit411in accordance with the control of a drawing control unit815described below. The piezoelectric element changes shape or vibrates with the application of the voltage. Accordingly, an unillustrated ink channel is compressed to eject the ink from the nozzle of the ejection surface.

The drawing tool unit72includes at least one drawing tool71that draws on the nail T in contact with the surface of the nail T of the print finger U1.

The drawing tool71is held by a drawing tool holding portion73.

In the embodiment, the drawing tool unit72includes four drawing tool holding portions73(described below) that hold the drawing tools71one by one. The number, shape, and the like of the drawing tool holding portions73are not limited to the illustrated example.

The drawing tool71can be replaced as appropriate by opening the above-mentioned drawing tool replacement purpose cover unit23.

The drawing tools71may be attached to all the drawing tool holding portions73, or may be attached to part of the four drawing tool holding portions73.

The drawing tool71being a drawing tool is for drawing in contact with the surface of the nail T while applying a drawing material such as ink, which is a liquid material, to the surface of the nail T.

The drawing tool (writing instrument)71held by the drawing tool holding portion73includes a penholder711and the nib712provided on a distal end side of the penholder711.

The inside of the penholder711is an ink storage portion that stores various inks.

The viscosity, the particle diameter (particle size) of a color material, and the like of the ink stored in the penholder711are not especially limited. For example, gold and silver lame inks, white ink, UV curing inks and gel polishes, undercoats, top coats, and nail polishes can also be used as the inks.

The drawing tool71is, for example, a pen having the ballpoint pen nib712through which the ink stored in the penholder711seeps by pressing the nib712against the surface of the nail T to enable drawing.

The drawing tool71is not limited to the ballpoint pen. The drawing tool71may be, for example, a marker pen that impregnates a felt tip with ink to draw, or a brush pen that impregnates a bundle of bristles with ink to draw. Various sizes can be prepared for the nib712.

If a plurality of the drawing tools71is held by the drawing tool holding portions73, each drawing tool71may be one having the nib712of the same type, or one having the nib712of a different type.

In the embodiment, four drawing tool holding portions73holding the drawing tools71are arranged in the width direction (the left-and-right direction, the X direction inFIG. 1) of the apparatus. Hence, the nibs712of the drawing tools71held respectively by the drawing tool holding portions73are respectively shifted in position in the X direction (the left-and-right direction of the apparatus). However, the shift amount is set to an integral multiple of one step in the drawing operation. The position is corrected by the number of steps equal to the shift amount according to the drawing tool71used for drawing. Drawing is then performed. Therefore, it is configured such that the four drawing tools71can draw at the same position.

Each drawing tool holding portion73is provided with a drawing tool holder731being a cylindrical portion that holds the drawing tool71substantially vertically.

The drawing tool holder731is configured to move the drawing tool71up and down in cooperation with a spring741and the solenoid742while holding the drawing tool71substantially vertically.

Specifically, while the solenoid742is being driven, the drawing tool71descends resisting the biasing force of the spring741to enter a drawing state where the drawing tool71can contact the surface of the nail T or drawn medium that is a drawing target.

While the solenoid742is open, the drawing tool71ascends due to the biasing force of the spring741to enter a non-drawing state where the drawing tool71is not in contact with the surface of the nail T or drawing medium.

In the embodiment, the solenoid742is used as the actuator for raising and lowering the drawing tool71. However, the actuator for raising and lowering the drawing tool71is not limited to the solenoid742. The drawing tool71is light-weight. Accordingly, the actuator for raising and lowering the drawing tool71can be configured of various small driving apparatuses such as a small motor, in addition to the solenoid.

The carriage support member44that supports the carriage42is fixed to an X-direction moving unit451attached to the X-direction moving stage45.

The X-direction moving unit451is configured to move in the X direction along an unillustrated guide on the X-direction moving stage45with the drive of the X-direction movement motor46. Consequently, the carriage42moves in the X direction (the X direction inFIG. 1, the left-and-right direction of the drawing apparatus1).

The X-direction moving stage45is fixed to a Y-direction moving unit471of the Y-direction moving stage47. The Y-direction moving unit471is configured to move in the Y direction along an unillustrated guide on the Y-direction moving stage47with the drive of the Y-direction movement motor48. Consequently, the carriage42moves in the Y direction (the Y direction inFIG. 2, the front-and-back direction of the drawing apparatus1).

In the embodiment, the X-direction moving stage45and the Y-direction moving stage47are configured to combine the X-direction movement motor46, the Y-direction movement motor48, and unillustrated ball screws and guides.

For example, step motors that move a predetermined amount whenever one pulse is transmitted are applied as the X-direction movement motor46and the Y-direction movement motor48of the embodiment.

In the embodiment, the X-direction movement motor46, the Y-direction movement motor48, and the like form a carriage moving unit49(seeFIG. 5) that moves, in the X and Y directions, the carriage42including the drawing tools71for drawing on the nail T.

The ink ejection unit411of the drawing head41, the solenoid742for moving the drawing tool71up and down, the X-direction movement motor46, and the Y-direction movement motor48in the drawing unit40are connected to the drawing control unit815(seeFIG. 5) of the control apparatus80described below, and configured to be controlled by the drawing control unit815.

As illustrated inFIGS. 1 and 2, a base plate13is installed in the upper machine casing12.

A guide rail57is provided to the backside (that is, the lower side inFIGS. 1 and 2) of the base plate13, extending in the front-and-back direction (the Y direction inFIG. 2) of the apparatus.

A moving stage56is attached to the guide rail57.

The moving stage56is configured to be movable by a stage movement purpose motor58(seeFIG. 5) along the guide rail57in the front-and-back direction (the Y direction inFIG. 2) of the apparatus.

A light application unit55is installed at substantially the center in the left-and-right direction (that is, the X direction inFIG. 1) on an undersurface of the moving stage56in the back (that is, the left side inFIG. 2) of the apparatus in the front-and-back direction (that is, the Y direction inFIG. 2).

In the embodiment, the light application unit55includes a light source that emits, for example, laser light as light, and a slit portion for changing the light emitted from the light source to light of a straight shape (line shape) in the left-and-right direction.

The light application unit55applies the light from the light source through the slit portion to apply the line-shaped light (hereinafter referred to as the line light) to a target. In the embodiment, the light application unit55functions as a target image formation unit that forms a line (target image) La (seeFIGS. 6A and 7A) in the width direction of a nail area detected by a nail area detection unit812adescribed below.

The light source of the light application unit55is not limited to the one that emits laser light. The light source may be one that includes, for example, an LED and emits light generated by light emission of the LED.

The light application unit55is placed in an orientation from the back of the apparatus toward the finger receiving section31in the front of the apparatus, the orientation being inclined at a predetermined inclination angle with respect to a plane direction of the mounting surface116con a virtual perpendicular plane being perpendicular to the plane direction of the mounting surface116cof the finger mounting section116a, intersecting the width direction of the nail T, and extending along the insertion direction of the print finger U1into the finger receiving section31.

The light application unit55is configured to apply the line light of one straight line (line shape) along the width direction of the nail T onto the print finger U1inserted in the finger receiving section31, and its nail T from an obliquely upward position (in the embodiment, from obliquely above with respect to the nail end direction), deviating in the finger extending direction from directly above the nail T.

In other words, the line light applied from the light application unit55is a straight line along the width direction of the nail T when viewed from the application direction.

In the embodiment, the moving stage56is moved in the Y direction as appropriate to adjust the position of the light application unit55. Accordingly, the position of the light application unit55is set such that at least a portion having a maximum length in the width direction of the nail T, or its vicinity, is exposed to the line light applied from the light application unit55.

Furthermore, the position of the light application unit55is preferable to be set to a position, the line light from which is also applied to a skin portion of the print finger U1touching both ends of the nail T in the width direction. The curvature of the surface changes greatly at the locations where the both ends of the nail T in the width direction touch the skin portion of the print finger U1. Hence, when the position of the light application unit55is set to such a position, a line La formed on the nail and finger by being exposed to the line light passes the locations where both ends of the nail T in the width direction touch the skin portion of the print finger U1. Consequently, two feature regions that can be clearly distinguished from the other portions appear in a line image Lb (seeFIG. 4) obtained by imaging the line La. The feature regions are described in detail below.

The light application unit55as the target image formation unit is not limited to the one that applies the line light. It may be, for example, one that performs scanning in the width direction while applying a beam light emitted from the light source to the nail T. In this case, the light application unit55further includes a mechanism that performs scanning in the width direction of the nail (that is, the X direction inFIG. 1) with the beam light emitted from the light source.

The light application unit55is connected to a light source control unit816(seeFIG. 5) of the control apparatus80described below to be controlled by the light source control unit816.

A camera51as an imaging apparatus is installed at a position that is substantially the center in the left-and-right direction (that is, the X direction inFIG. 1) on the undersurface of the moving stage56and that is directly above the nail T of the print finger U1inserted in the finger receiving section31, or its vicinity.

The camera51preferably has, for example, approximately two million pixels or more.

The camera51is for imaging the nail T of the print finger U1inserted in the finger receiving section31from substantially directly above to obtain a finger image (an image of the print finger U1including an image of the nail T).

In the embodiment, the camera51further functions as a line imaging unit that images the line (target image) La (seeFIGS. 6A and 7A) formed on the surfaces of the nail T and the finger by the light application unit55and acquires a finger image including the line image Lb (seeFIG. 4).

As described below, in the embodiment, the inclination detection unit812bdetects the height-wise shape of the nail T in the width direction based on the principle of triangulation from the line image (target picture) Lb in the finger image acquired by the camera51.

Hence, in the embodiment, the light application unit55is placed in the back of the apparatus. The line light is applied by the light application unit55to the print finger U1having the nail T not from directly above or directly beside the nail T but from the position deviating in the finger extending direction at the predetermined inclination angle (for example, approximately 45 degrees inFIG. 3) with respect to the plane direction of the mounting surface116c. The camera51then images the line La formed by the light application unit55from substantially directly above the nail T of the print finger U1.

FIG. 4is an example of the finger image obtained by imaging the line La formed on the surfaces of the print finger U1inserted in the finger receiving section31, and its nail T.

The line (target image) La formed by the line light applied at the predetermined inclination angle is imaged from substantially directly above the nail T. Accordingly, the finger image including the line image (target picture) Lb having an arc shape illustrated inFIG. 4is imaged.

The placement and the like of the light application unit55and the camera51are not limited to the illustrated examples.

For example, the inclination angle at which the light application unit55applies the line light to the print finger U1having the nail T is not limited to 45 degrees, but is simply required to be approximately between 30 degrees and 70 degrees.

The position and the inclination angle of the camera51are not limited to the placement where the nail T of the print finger U1inserted in the finger receiving section31is imaged from substantially directly above as in the illustrated examples, but are simply required to be placement where whole area of the nail T can be imaged.

For example, contrary to the embodiment, the light application unit55may be placed substantially directly above the nail T of the print finger U1inserted in the finger receiving section31to apply the line light to the surface of the nail T from a direction substantially perpendicular to the plane direction of the mounting surface116c. The camera51may be configured to image the line La from obliquely above (for example, from obliquely above in the nail end direction), deviating in the finger extending direction from directly above the nail T.

In other words, it is required that the direction in which the line light is applied to the nail T by the light application unit55is set to a direction having a first angle with respect to the plane direction of the mounting surface116con the virtual perpendicular plane, and that the direction of the optical axis of the camera51with respect to the nail T is set to a direction having a second angle, which is different from the first angle, with respect to the plane direction of the mounting surface116con the virtual perpendicular plane. At this point in time, the difference between the first and second angles is the above inclination angle.

Illumination lamps (illumination devices)52such as white LEDs are installed on the moving stage56in such a manner as to surround the camera51. The illumination lamp52is for illuminating the nail T of the print finger U1when the camera51images the nail T.

An imaging unit50in the embodiment is configured including the camera51and the illumination lamps52.

The imaging unit50is connected to an imaging control unit811(seeFIG. 5) of the control apparatus80described below to be controlled by the imaging control unit811.

Image data of an image imaged by the imaging unit50is stored in a nail image storage area821of a storage unit82described below.

The control apparatus80is installed on, for example, the base plate13placed in the upper machine casing12.

FIG. 5is a main part block diagram illustrating a control configuration in the embodiment.

As illustrated inFIG. 5, the control apparatus80is a computer including a control unit81configured of a CPU (Central Processing Unit) and the storage unit82configured of ROM (Read Only Memory), RAM (Random Access Memory), and the like (none are illustrated).

Various programs, various types of data, and the like for operating the drawing apparatus1are stored in the storage unit82.

Specifically, various programs such as a nail information detection program for detecting nail information on the shape and the position of the nail T, the degree of the inclination of the nail T, and the like from a finger image, a drawing data generation program for generating drawing data, and a drawing program for performing a drawing process are stored in the ROM of the storage unit82. Each unit of the drawing apparatus1is configured to be centrally controlled by the control apparatus80executing these programs.

In the embodiment, the storage unit82is provided with the nail image storage area821that stores an image of the nail T of the print finger U1of the user (a finger image including the image of the nail T) acquired by the imaging unit50, a nail information storage area822that stores the nail information detected by a nail information detection unit812, a design storage area823that stores image data of design images to be drawn on the nail T, and the like.

The control unit81includes the imaging control unit811, the nail information detection unit812, a drawing data generation unit813, a display control unit814, the drawing control unit815, and the light source control unit816from the viewpoint of functions.

The functions as the imaging control unit811, the nail information detection unit812, the drawing data generation unit813, the display control unit814, the drawing control unit815, and the like are achieved by the cooperation between the CPU of the control unit81and the programs stored in the ROM of the storage unit82.

The imaging control unit811is for controlling the camera51and the illumination lamps52of the imaging unit50to image an image of the nail T of the print finger U1inserted in the finger receiving section31with the camera51.

In the embodiment, the imaging control unit811controls the camera51and the illumination lamps52of the imaging unit50to image the nail T of the print finger U1and acquire an image of the nail T.

The imaging control unit811further controls the camera51and the illumination lamps52of the imaging unit50serving as the line imaging unit to image the print finger U1having the nail T, on the surface of which the inclination detection purpose line La has been drawn by the light application unit55, and to acquire an image of the print finger U1including the line image Lb.

The nail information detection unit812is for detecting nail information of the nail T of the print finger U1based on the image of the nail T of the print finger U1imaged and acquired by the camera51.

In the embodiment, the nail information detection unit812includes the nail area detection unit812aand the inclination detection unit812b.

The nail information here includes information on the shape and size of the nail area formed by the outline of the nail T, and the position (horizontal position) of the nail T, the degree of the inclination of the nail T, and the like.

The nail area detection unit812adetects the outline of the nail T and detects whole area formed by the outline of the nail T as the nail area. The nail area detected by the nail area detection unit812abecomes a drawing area where drawing is performed by the drawing unit40.

The inclination detection unit812bdetects the degree of the inclination of the nail T in the width direction with respect to a proper posture (reference state) that the nail T is not inclined, caused by the print finger U1's rotation (roll) about the lengthwise axis of the print finger U1, the axis intersecting the width direction of the nail T.

As described below, the inclination detection unit812bdetects the curved shape of the nail T (the curvature of the nail T in the width direction, hereinafter referred to as the nail curvature) in the process of detecting the degree of the inclination of the nail T. The curved surface correction is performed on a design image based on the nail curvature detected by the inclination detection unit812b. Accordingly, nail printing with beautiful finish without distortion becomes possible in the drawing apparatus1.

A specific description is given here of the detection of the nail information by the nail information detection unit812.

The nail area detection unit812adetects the shape, size, and position of the outline of the nail T from the finger image including the nail image of the nail T of the print finger U1, the finger image having been acquired by the camera51, based on, for example, a difference in color between the nail T and the finger part other than the nail T. The outline is acquired as information on the outline of the nail T represented by x and y coordinates or the like.

The nail area detection unit812a's method for detecting the outline (shape and the like) of the nail T is not especially limited, and not limited to the one described herein.

If the print finger U1is rotated about the lengthwise axis of the print finger U1, the inclination detection unit812bdetects the degree of the inclination of the nail T caused by the rotation based on the finger image (the image of the print finger U1including the image of the nail T) including the inclination detection purpose line La image (that is, the line image Lb) imaged by the camera51.

In the embodiment, firstly, the inclination detection unit812bdetects the line image Lb from the finger image based on, for example, differences in color and light reflection condition between the nail T and the finger part.

The degree of the inclination of the nail T is then detected based on the line image Lb.

In other words, the positions and inclination angles of the camera51and the light application unit55are preset on the apparatus side. The set values are known.

When the line light is applied from obliquely above, deviating in the finger extending direction from directly above the nail T, the line La formed by the line light on the surfaces of the nail T and the print finger U1is a straight line when viewed from the line light application direction as illustrated inFIGS. 6A and 7A.

When the line La formed by the line light on the surfaces of the nail T and the print finger U1is imaged from substantially directly above the nail T, the line La is curved following the shapes of the surfaces of the nail T and the print finger U1. The finger image (the image of the print finger U1including the image of the nail T) including the arc-shaped line image Lb illustrated inFIG. 4is imaged.

The inclination detection unit812bcalculates a finger shape curve Lc indicating changes, along the width direction of the nail T, in actual heights of the surfaces of the nail T and the print finger U1on which the line La is formed (that is, changes, along the width direction of the nail T, in height-wise distance of the nail T between a given reference position and the surface of the nail T, at a location where the line La on the nail T and the print finger U1is formed) as illustrated inFIGS. 6B and 7B, with the principle of triangulation based on the shape of the line image Lb and the value of the above inclination angle.

If the line image Lb has some width (that is, if the line La is relatively bold), the inclination detection unit812bextracts a widthwise central position of the line image Lb (for example, a portion having the highest brightness) to detect the degree of the inclination of the nail T using the central position.

The line light is assumed here to be formed into a shape of one straight line. However, the shape of the line light is not limited to this.

For example, the line light may have a shape having a side of a straight line shape along the width direction of the nail T and having the other part of an arbitrary shape such as a curve. In this case, the part being the straight line shaped side is used to enable detection of the degree of the inclination of the nail T.

Furthermore, the line light may not be of the shape having the straight line shaped side, but may be one including a part formed in a preset shape such as a curve or broken line. Also in this case, the part formed in the preset shape is used to enable detection of the curved shape of the nail T.

FIGS. 6B and 7Billustrate the finger shape curve Lc obtained by plotting widthwise changes in heights of the surfaces of the nail T and the print finger U1, the changes being calculated by the inclination detection unit812bwith the principle of triangulation based on the shape of the line image Lb and the value of the above inclination angle.

In other words, the finger shape curve Lc indicates widthwise changes in heights of the surfaces of the nail T and the print finger U1.

A case is illustrated here in which the skin portion of the print finger U1touching the ends of the nail T in the width direction are also exposed to the line light. The inclination detection unit812bsets, as a reference state, a state where the shape on one side (right side) of the finger shape curve Lc across the center in the width direction of the nail T and its shape on the other side (left side) across the center are shapes having symmetry within a predetermined allowable range. If the finger shape curve Lc is in the reference state, the inclination detection unit812bdetermines that the print finger U1is mounted appropriately in the finger receiving section31and the degree of the inclination of the nail T is within the allowable range. On the other hand, if the finger shape curve Lc deviates from the reference state, the inclination detection unit812bdetermines that the print finger U1is inclined with respect to the state where it is mounted appropriately in the finger receiving section31and the degree of the inclination of the nail T exceeds the allowable range.

FIG. 6Billustrates the finger shape curve Lc of when the print finger U1is hardly rotated about the lengthwise axis (rotation axis) of the print finger U1with respect to the reference state to be hardly inclined, and the print finger U1is mounted appropriately in the finger receiving section31, as illustrated inFIG. 6A.

On the other hand,FIG. 7Billustrates the finger shape curve Lc of when the print finger U1is rotated relatively largely about the lengthwise axis (rotation axis) of the print finger U1with respect to the reference state to be inclined relatively largely in the finger receiving section31, as illustrated inFIG. 7A.

InFIGS. 6B and 7B, regions Pa1and Pa2surrounded by dot-and-dash lines on the finger shape curve Lc correspond to the locations where the ends of the nail T in the width direction touch the skin portion of the print finger U1, and their vicinities. The shapes in the regions are reduced in height with respect to both sides in the width direction corresponding to the positions of the regions. The curvature of the finger shape curve Lc changes greatly with respect to both sides. The direction of the curve is also opposite to both sides.

In the embodiment, the regions Pa1and Pa2on the finger shape curve Lc are set as feature regions. Points where the curvature of the finger shape curve Lc changes greatly in the feature regions Pa1and Pa2are set as feature points Pp1and Pp2.

FIG. 7Billustrates a case where the inclination of the print finger U1is large and accordingly the left feature region Pa1is visible and the right feature region Pa2is not visible.

As illustrated inFIG. 6B, if the two feature points Pp1and Pp2exist on the finger shape curve Lc, the shape of a region between the two feature points Pp1and Pp2on the finger shape curve Lc indicates widthwise changes in height of the surface of the nail T. The shapes of regions outward of the two feature points Pp1and Pp2on the finger shape curve Lc indicate widthwise changes in height of the surface of the finger's other part than the nail T.

In the embodiment, how the height of the nail T changes between the two feature points Pp1and Pp2, which is detected by the inclination detection unit812b, is detected assuming to indicate the curved shape (the nail curvature) of the nail T.

The inclination detection unit812bof the embodiment calculates the finger shape curve Lc illustrated inFIGS. 6B and 7Bthat illustrate changes along the width direction in height of the surface of the nail T and then calculates an evaluation value indicating the degree of the inclination of the nail T caused by rotation about the lengthwise axis (rotation axis) of the finger.

Methods for evaluating the degree of the inclination of the nail T is described below.

As a first method, firstly, the calculated finger shape curve Lc indicating changes along the width direction in height of the nail T is assumed to be a graph Gx where the vertical axis (height) direction is G and the horizontal axis (width) direction is x, as illustrated inFIGS. 8 and 10. The left end of the finger shape curve Lc is aligned with a position of an origin (x=0) of the horizontal axis.

When a maximum value of the finger shape curve Lc in the horizontal axis direction is W, the width of the finger shape curve Lc in the horizontal axis direction is W. A center point (W/2) of the width (W) in the horizontal axis direction on the finger shape curve Lc is obtained.

One of the right and left sides of the finger shape curve Lc across the center point (W/2) is reversed horizontally to overlay the other. Consequently, the symmetry of the right and left sides of the finger shape curve Lc across the widthwise center point are determined.

For example, the graph illustrated inFIG. 8corresponds toFIG. 6Bof when the finger is hardly rotated about the lengthwise axis (rotation axis) of the finger with respect to the reference state and accordingly the nail T is hardly inclined.

In this case, the shape of the left side of the finger shape curve Lc across the center point (W/2) is a shape indicated by a solid line inFIG. 9A.

The right side of the finger shape curve Lc across the center point (W/2) is set as one side. The one side is reversed horizontally. Its shape is a shape indicated by a dot-and-dash line inFIG. 9B.

As illustrated inFIG. 9C, if the finger is hardly rotated and the nail is hardly inclined, one of the right and left shapes of the finger shape curve Lc across the center point (W/2) is reversed horizontally, and overlays the other. They are substantially superposed. In other words, in this case, it can be seen that the finger shape curve Lc has a shape having substantially left-right symmetry.

In terms of such a left-right symmetry, the degree of the left-right symmetry of the finger shape curve Lc can be evaluated by an evaluation value (first specific value) calculated by an evaluation equation where the value is zero at the time of having left-right symmetry, such as illustrated in the following equation 1.

It is considered to be difficult in practice to obtain the widthwise midpoint of the nail T. Hence, the evaluation value may also be calculated for cases where the center point is (W/2)−1 and (W/2)+1 to set a minimum value among them as the evaluation value.

Many of human fingers (fingers having the nail T) are substantially left-right symmetric in terms of the height-wise shape. Hence, the evaluation value is small in the reference state where the finger is hardly rotated about the lengthwise rotation axis of the finger.

In contrast, if the finger is rotated about the lengthwise rotation axis of the finger with respect to the reference state, and the nail T is inclined, the larger the inclination, the larger the evaluation value.

For example, the graph illustrated inFIG. 10corresponds toFIG. 7Bof when the finger is rotated relatively largely about the lengthwise rotation axis of the finger.

In this case, the shape of the left side of the finger shape curve Lc across the center point (W/2) is a shape indicated by a solid line inFIG. 11A.

The right side of the finger shape curve Lc across the center point (W/2) is set as the other side. When the other side is reversed horizontally, its shape is a shape indicated by a dot-and-dash line inFIG. 11B.

As illustrated inFIG. 11C, if the finger is rotated relatively largely with respect to the reference state, when the right and left sides of the finger shape curve Lc across the center point (W/2) are superimposed, it can be seen that they are displaced largely from each other and are not left-right symmetric.

In such a case, the evaluation value calculated by the above evaluation equation is increased.

In the embodiment, it is configured to notify the user, if it is the case, that the calculated evaluation value is larger than a predetermined threshold value (first threshold value).

A specific notification method is not especially limited. However, for example, an alert such as “The nail is inclined. Place the finger straight again.” is displayed on the display unit26to prompt the user to insert the print finger U1(the nail T) again or adjust the position of the inserted finger in the rotation direction.

When the evaluation value is equal to or less than the threshold value (the first threshold value), a drawing data correction unit813acorrects the drawing data in accordance with the degree of the inclination of the nail T, as appropriate. The drawing operation is then performed.

In the first method, the feature regions Pa1and Pa2may not exist on the finger shape curve Lc. Hence, when the first method is applied, the position where the nail T is exposed to the line light may be a position where the finger skin portion touching the ends of the nail T in the width direction are not exposed to the line light.

As a second method, firstly, the two feature regions Pa1and Pa2including the feature points Pp1and Pp2where the curvature changes greatly at the boundaries between the nail T part and the finger part are extracted as illustrated inFIGS. 6B and 7B.

The difference in height between the two feature points Pp1and Pp2respectively in the two feature regions Pa1and Pa2is calculated to set the calculation result as an evaluation value (a second specific value).

For example, when the finger is hardly rotated with respect to the reference state, and the nail T is not inclined, the heights of the two feature points Pp1and Pp2are substantially the same, as illustrated inFIG. 6B. Hence, the evaluation value is small.

In contrast, when the finger is rotated relatively largely with respect to the reference state and the nail T is inclined relatively largely, the heights of the two feature points Pp1and Pp2are very different from each other. Hence, the evaluation value is large. Alternatively, as illustrated inFIG. 7B, only the feature point Pp1is detected to result in a large evaluation value.

When the evaluation value is larger than a predetermined threshold value (a second threshold value), it is notified to the user as in the first method.

On the other hand, when the evaluation value is equal to or less than the threshold value (the second threshold value), the drawing data correction unit813acorrects the drawing data in accordance with the degree of the inclination of the nail T, as appropriate. The drawing operation is then performed.

In the second method, at least one of the feature regions Pa1and Pa2needs to exist on the finger shape curve Lc. Hence, when the second method is applied, a position where the nail T is exposed to the line light needs to be a position where the finger skin portion touching the end of the nail T in the width direction is also exposed to the line light.

In terms of the above two methods for obtaining an evaluation value corresponding to the degree of the inclination of the nail T (that is, the first method in which left-right symmetry of the widthwise shape of the nail T, which can be detected from the finger shape curve Lc, is evaluated, and the second method in which the difference in height position between the two feature points Pp1and Pp2on the finger shape curve Lc is evaluated), one of the methods may be applied, or both methods are used in combination.

When both methods are used in combination, a determination may be made depending on, for example, whether or not the value of a total of the evaluation values obtained by the methods exceeds a predetermined threshold value.

The inclination detection unit812b's method for detecting the degree of the inclination of the nail T, and the method for evaluating the degree of the inclination of the nail T are not limited to those illustrated here.

The threshold values of the evaluation values in the above methods are set as appropriate, from the viewpoint of whether or not the correction of drawing data to be made by the drawing data correction unit813awill do. In other words, the threshold value of the evaluation value is set to a value that enters a state where drawing data can be corrected by the drawing data correction unit813aif the evaluation value does not exceed the threshold value, and to a value that enters a state where drawing data cannot be corrected by the drawing data correction unit813aif the evaluation value exceeds the threshold value.

The level of correctable inclination also depends on the curved shape (the nail curvature) of the nail T. Therefore, it is preferable to set the threshold value of the evaluation value in accordance with the nail curvature of the nail T.

For example, an arc pattern1corresponding to a range where the nail curvature is relatively small, an arc pattern3corresponding to a range where the nail curvature is relatively large, and an arc pattern2corresponding to a range where the nail curvature is between them are preset. A threshold value of the evaluation value corresponding to each arc pattern is stored in advance in the storage unit82or the like.

The curved shape of the nail T is classified into any of the three arc patterns according to the value of the nail curvature.

A threshold value of the evaluation value applied to the nail T may be decided depending on the classified arc pattern.

A threshold value of the evaluation value may be stored in advance in the storage unit82or the like, associated with a user name, the type of finger, and the like after the threshold value is set once for the nail T. The threshold value may be read from the storage unit82to be applied when the nail T of the same finger of the same user is targeted for drawing.

The drawing data generation unit813generates data for drawing to be drawn on the nail T of the print finger U1by the drawing unit40based on the nail information detected by the nail information detection unit812.

Specifically, the drawing data generation unit813performs an adjustment process (a fitting process) by reducing or enlarging the image data of a design image based on the nail information on the shape and the like of the nail T detected by the nail information detection unit812. Accordingly, the drawing data generation unit813generates drawing data for drawing the design image on the nail T.

The drawing data generation unit813of the embodiment includes the drawing data correction unit813athat corrects drawing data.

The nail T is inclined due to rotation about the rotation axis in the finger extending direction. However, when it is determined to be within a range where the correction of the drawing data by the drawing data correction unit813awill do (that is, when the evaluation value is equal to or less than a predetermined threshold value), the drawing data correction unit813acorrects the drawing data for drawing on the nail T based on the detection result of the inclination detection unit812b.

Furthermore, in the embodiment, the curvature of the nail T is detected by the inclination detection unit812b. The drawing data correction unit813acorrects the drawing data (curved surface correction) in accordance with the nail curvature.

When the curved shape of the nail T is classified into any of a plurality of arc patterns (for example, the arc patterns1to3), and a correction value for the curved surface correction is prepared for each arc pattern, the drawing data correction unit813acorrects the drawing data (the curved surface correction) in accordance with the correction value corresponding to the classified arc pattern of the nail T.

The display control unit814is for controlling the display unit26to display various display screens on the display unit26.

In the embodiment, the display control unit814is configured to display, on the display unit26, for example, a design image selection screen, a thumbnail image for a design check, a finger image obtained by imaging the print finger U1, and a nail image included in the finger image (an image of the nail T), and various instruction screens.

In the embodiment, when it has been determined that the degree of the inclination of the nail T exceeds a predetermined threshold value, the display control unit814causes the display unit26to display an alert to prompt the resetting of the finger to notify the user of the excess.

The drawing control unit815outputs, to the drawing unit40, the drawing data of the design image generated by the drawing data generation unit813after the curved surface correction has been made as appropriate. The drawing control unit815controls the operation of the X-direction movement motor46and the Y-direction movement motor48of the carriage moving unit49of the drawing unit40, the ink ejection unit411of the drawing head41, and the solenoid742that raises or lowers the drawing tool71to draw on the nail T in accordance with the drawing data.

The light source control unit816is for controlling the operation of the light application unit55.

In the embodiment, the light source control unit816is configured to apply the line light from the light application unit55to a position of the longest portion (that is, a broad portion) of the nail T in the width direction, or its vicinity, within the nail area detected by the nail area detection unit812a, further preferably a position where a finger skin portion touching an end of the nail T in the width direction is also exposed to the line light.

The control unit81controls the stage movement purpose motor58as appropriate to move the moving stage56along the guide rail57in the Y direction (that is, the front-and-back direction of the drawing apparatus1). The control unit81adjusts the position of the light application unit55in such a manner as to apply the line light from the light application unit55to a position of the longest portion of the nail T in the width direction, or its vicinity, further preferably a position where a finger skin portion touching an end of the nail T in the width direction is also exposed to the line light.

Specifically, the line light application position is grasped on the apparatus side based on the image of the camera51. In accordance with this, the position of the light application unit55is automatically adjusted.

The adjustment of the position of the light application unit55is not limited to the case of automatic adjustment. For example, an image imaged by the camera51may be displayed on the display unit26as appropriate. The user may adjust the position of the light application unit55manually while looking at the display.

Next, the operation of the drawing apparatus1and a method for calculating the evaluation value using the drawing apparatus1in the embodiment are described.

FIG. 12is a flowchart illustrating the flow of the method for calculating the evaluation value of a nail of the embodiment.

As illustrated inFIG. 12, if the drawing apparatus1is used to detect the degree of the inclination of the nail T, the user turns on a power switch first to start the control apparatus80.

Next, the user inserts the print finger U1into the finger receiving section31, inserts the non-print fingers U2into the finger withdrawal section32, and fixes the print finger U1. The user then operates a switch to start a detection operation.

When an instruction is input from the switch, the imaging control unit811controls the imaging unit50to cause the camera51to image the print finger U1while illuminating the print finger U1with the illumination lamps52.

Consequently, the imaging control unit811acquires a finger image of the print finger U1inserted in the finger receiving section31(Step S1).

Next, the nail area detection unit812adetects (calculates) the outline (nail area) of the nail T based on the finger image (Step S2).

The light source control unit816obtains a specific location where the length of the nail T in the width direction (x direction) is maximum, or its vicinity, further preferably where the skin portion of the print finger U1touching an end of the nail T in the width direction is also exposed to the line light, within the detected nail area of the print finger U1(Step S3).

The line light is applied to the specific location of the print finger U1by the light application unit55to draw the inclination detection purpose line La (seeFIGS. 6A and 7A) in the width direction of the nail T (Step S4).

When the line La has been formed on the nail T, the imaging control unit811controls the imaging unit50again to cause the camera51to image the print finger U1while illuminating the print finger U1with the illumination lamps52. Consequently, the imaging control unit811acquires a finger image including the line image Lb corresponding to the line La drawn on the nail T (Step S5).

When the finger image has been acquired, the inclination detection unit812bdetects the line image Lb from the finger image based on the difference in color from the nail T, and the like (Step S6).

The inclination detection unit812bthen calculates the finger shape curve Lc indicating changes, along the width direction, in heights of the surfaces of the nail T and the print finger U1based on the line image Lb (Step S7).

The degree of the inclination of the nail T is then evaluated based on the calculated finger shape curve Lc to determine whether or not the degree of the inclination is within a range where the drawing data correction unit813acan correct the drawing data (Step S8).

Specifically, for example, an evaluation value for evaluating the left-right symmetry of a curve representing the height-wise position of the nail T is calculated. Alternatively, height-wise positions of a plurality of feature points appearing on a curve representing the height-wise position of the nail T are compared to calculate an evaluation value. It is then determined whether or not the evaluation value exceeds a predetermined threshold value corresponding to the drawing data correctable range.

If it has been determined that the degree of the inclination of the nail T is within the correctable range (that is, if the evaluation value is equal to or less than the threshold value, Step S8; YES), the drawing data correction unit813aobtains a correction value in accordance with the degree of the inclination of the nail T to correct the drawing data (Step S9). The drawing data correction unit813adraws the design image with the corrected drawing data (Step S10).

In contrast, if it has not been determined that the degree of the inclination of the nail T is within the correctable range (that is, if the evaluation value exceeds the threshold value, Step S8; NO), it is notified the user by, for example, causing the display unit26to display a prompt to reset the print finger U1(Step S11). The drawing operation is finished.

As described above, according to the embodiment, the line light is applied to the nail T. Accordingly, the line La is formed in the width direction of the nail area. The inclination detection unit812bdetects the degree of the inclination of the nail T based on the line image Lb obtained by imaging the line La from obliquely above.

Consequently, if the nail T is inclined due to the rotation of the finger about the axis in the extending direction, the degree of the inclination of the nail T can be detected relatively easily and reliably.

If the inclination detection unit812bcompares the height-wise positions of the two feature points Pp1and Pp2on the finger shape curve Lc to detect the degree of the inclination of the nail T, the degree of the inclination of the nail T can be detected reliably with a simple process.

If the inclination detection unit812bevaluates the symmetry of the finger shape curve Lc in the width direction of the nail T to detect the degree of the inclination of the nail T, it is not always necessary to form the line La including the feature point Pp and acquire the line image Lb including the feature point Pp. In other words, as long as the finger shape curve Lc with some width including the center point (W/2) in the width direction of the nail T can be calculated, left-right symmetry can be determined. In this case, even if, for example, the feature point Pp is difficult to obtain due to reasons such as a special shape of the nail T, the degree of the inclination of the nail T can be detected appropriately.

The method in which the height-wise positions of the feature points Pp are compared, and the method in which symmetry in the width direction of the nail T is evaluated may be used in combination to determine the degree of the inclination of the nail T. In that case, the degree of the inclination of the nail T can be detected more reliably.

In the embodiment, it is configured such that a message is displayed on the display unit26or the like to notify the user, if it is the case, that the degree of the inclination of the nail T detected by the inclination detection unit812bexceeds the range where the drawing data correction unit813acan correct drawing data. Hence, it is possible to prevent the occurrence of a failure in nail printing by drawing without being aware of the state where the nail T is inclined.

An embodiment to which the present invention can be applied is not limited to the above-mentioned embodiment, and can be changed within a scope that does not depart from the spirit of the present invention as appropriate.

For example, in the above embodiment, the case has been illustrated by example in which the drawing control unit815forms only one (single) line La at one location having a maximum width in the width direction of the nail T, or its vicinity, within the nail area, and the inclination detection unit812bdetects the degree of the inclination of the nail T based on the line image Lb obtained by imaging the line La. However, the detection of the degree of the inclination of the nail T by the inclination detection unit812bis not limited to this.

For example, a plurality of lines La is formed along the width direction of the nail T. The imaging unit50is caused to image the plurality of lines La to acquire a plurality of line images Lb. The degree of the inclination of the nail T may be detected based on the plurality of line images Lb.

If the number of line images Lb targeted for detection is increased, it becomes possible to acquire a more detailed three-dimensional shape of the nail T. The drawing data is corrected based on the acquired shape. Accordingly, it becomes possible to draw very finely on the nail T.

In the embodiment, the cases have been illustrated by example of taking an image for detecting the outline and the like of the nail T with one camera51and of taking an image for obtaining the line image Lb. However, it is not limited to the configuration in which an image is taken by only one camera. For example, a first camera for obtaining the line image Lb may be placed in the back of the apparatus, and a second camera that acquires an image for detecting the outline and the like of the nail T may be placed, for example, directly above the nail T separately from the first camera.

In the embodiment, the case has been illustrated by example in which the line light is applied by the light application unit55to draw and form the inclination detection purpose line La. However, the means for forming the line La is not limited to the light application unit55. For example, the line La may be formed by drawing a straight line in the width direction on the surface of the nail T with drawing tools such as the drawing head41and the drawing tool71.

In this case, for example, the line La may be drawn using an ink of a color (for example, white) that acts as a background (base coat) of a nail design to be drawn on the nail T.

In such a case, there is no need to remove the line La before drawing the nail design on the nail T. The nail design can be drawn subsequent to the process of detecting the degree of the inclination of the nail T.

Furthermore, a straight line may be drawn on the surface of the nail T with an ink that emits light and becomes visible when predetermined light is applied, such as an ultraviolet light-emitting clear coat, to form the inclination detection purpose line La.

In this case, a light source that can apply light with a predetermined intensity for causing the coat to emit light (for example, a black light that applies ultraviolet light) is included in the apparatus. When the line La is imaged to obtain the line image Lb, the predetermined light is applied to the surface of the nail T by the light source to take an image while the line La is emitting light.

In such a case, the line La is invisible under a normal state (that is, a state where the light is not applied by the predetermined light source), there is no need to remove the line La before drawing a nail design on the nail T. The nail design can be drawn subsequent to the process of detecting the degree of the inclination of the nail T.

In the embodiment, the case has been illustrated by example in which the camera51and the light application unit55are attached to the moving stage56and are configured to be movable in the Y direction (that is, the front-and-back direction of the drawing apparatus1). However, that the camera51and the light application unit55are configured to be movable is not an essential element of the present invention. For example, the light application unit55may be placed in a fixed manner at a position where the line light can be applied to the nail T, and the camera51may be placed in a fixed manner at a position where a line formed by the line light can be imaged from obliquely above.

In the embodiment, the case has been illustrated by example in which the drawing apparatus1is a hybrid nail printing apparatus including, as drawing tools, the inkjet drawing head41and the drawing tools71. However, the drawing apparatus is not limited to this. For example, it may be a plotter nail printing apparatus including only the drawing tools71or a nail printing apparatus including only the inkjet drawing head.

Up to this point some embodiments of the present invention have been described. However, the scope of the present invention is not limited to the above-mentioned embodiments, and includes the scope of the invention described in the claims and its equivalent.