Patent Publication Number: US-2016227900-A1

Title: Nail molding device and nail molding method

Description:
TECHNICAL FIELD 
     The present invention relates to a nail forming device and a nail forming method for drawing on nails or artificial 
     BACKGROUND ART 
     With a nail art of drawing on the surface of a nail, a user generally has a desired design drawn by a nail technician at a nail salon. As the material of the nail, a gel nail made of a photo-curable resin is widely used. With the widespread of gel nails, consume the nail art are on the increase. 
     In recent years, due to the facility of the gel nails, more and more users are applying the nail art themselves. As a product for supporting application of the nail art by users themselves, a starter kit, which is a set of gels and a resin curing lamp, is being sold. 
     For example, Patent Literatures 1 and 2 disclose methods for having a resin-coated finger (nail) inserted into an opening portion of a resin curing lamp, and for radiating the entire finger inserted in the opening portion by the resin curing lamp. Patent Literature 3 discloses a configuration of a pen-type resin curing lamp with a small light radiation area, which takes into account the influence of UV light for resin curing on the human body. Patent Literature 4 discloses a configuration which includes a two-wavelength light source to be used according to the type of a photo-curable resin. 
     CITATION LIST 
     Patent Literature 
     PTL 1: Utility Model Registration No. 3151698 
     PTL 2: Utility Model Registration No. 3183499 
     PTL 3: Utility Model. Registration No. 3179777 
     PTL 4: Unexamined Japanese Patent Publication No. 2011-98073 
     SUMMARY OF THE INVENTION 
     A nail forming device according to a mode of the present invention is a nail forming device for forming a drawing pattern on a surface of a nail or an artificial nail by using a photo-curable resin, the device including a light source, an optical drawing unit for partially curing the photo-curable resin by using light emitted by the light source, and a controller for controlling the light source and the optical drawing unit. 
     Also, a nail forming method according to a mode of the present invention is a nail forming method for forming a drawing pattern on a surface of a nail or an artificial nail by using a photo-curable resin. There are included coating the surface of the nail or the artificial nail with the photo-curable resin, partially curing the photo-curable resin, and removing a non-cured part of the photo-curable resin. Also, in the curing, the photo-curable resin is partially cured by using a nail forming device including a light source, an optical drawing unit for partially curing the photo-curable resin by using light emitted by the light source, and a controller for controlling the light source and the optical drawing unit. 
     According to the configurations described above, a drawing pattern may be easily formed on the surface of a nail or an artificial nail. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic diagram showing a nail forming device according to an exemplary embodiment of the present invention. 
         FIG. 2  is a perspective diagram of a reflection mirror configuring the nail forming device according to the exemplary embodiment of the present invention. 
         FIG. 3  is a diagram showing drawing patterns. 
         FIG. 4  is a schematic diagram showing a light radiation state of the nail forming device according to the exemplary embodiment of the present invention. 
         FIG. 5  is a schematic diagram showing a nail forming method that uses the nail forming device according to the exemplary embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     Before describing an exemplary embodiment, a problem inherent in a conventional nail art will be described. 
     Conventionally, the drawing skill of a user greatly affects the drawing of a nail art by the user himself/herself. Also, even if the drawing skill is high, in the case of drawing on the nails of the user himself/herself, it is difficult to achieve the same drawing accuracy for the nails of the dominant hand and the nails of the hand which is not the dominant hand. 
     Moreover, even in the case where a nail technician in a nail salon is to perform drawing, there is a limit on the drawing skill. However, higher accuracy is demanded for drawing. 
     EXEMPLARY EMBODIMENT 
     In the following, an exemplary embodiment of the present invention will be described with reference to  FIGS. 1 to 5 . 
     &lt;Configuration of Nail Forming Device  2 &gt; 
       FIG. 1  is a schematic diagram showing nail forming device  2  for drawing a nail art (for forming a drawing pattern) on nail  1 . Nail forming device  2  is nail forming device  2  for forming a drawing pattern on the surface of nail  1  (or an artificial nail) by using photo-curable resin  3 , and includes light source  4 , optical drawing unit  5  for partially curing photo-curable resin  3  by using light that is emitted from light source  4 , and controller  6  for controlling light source  4  and optical drawing unit  5 . 
     In the present exemplary embodiment, photo-curable resin  3  that is cured with UV light is used. 
     Light source  4  emits light of a wavelength by which photo-curable resin  3  is cured. Most of the gel nails (photo-curable resin  3 ) that are currently commercially available need wavelengths ranging from about 365 nm to 410 nm to be cured. Accordingly, in the present exemplary embodiment, a semiconductor laser having a wavelength peak at around 405 nm is used as light source  4 . Also, scanning reflection mirror  7  whose angle of reflection is controlled by controller  6  is used as optical drawing unit  5 . 
     As scanning reflection mirror  7 , a known mirror such as a polygon mirror or a galvanometer mirror is used. 
     &lt;Configuration of Reflection Mirror  7 &gt; 
     Next, the configuration of reflection mirror  7  be described in detail with reference to  FIG. 2 . 
     Reflection mirror  7  is configured from actuator  8  and mirror unit  12 . Actuator  8  is driven in two axes, and is a MEMS (Micro Electro Mechanical Systems) device that uses an Si substrate and a piezoelectric film. By configuring optical drawing unit  5  by actuator  8 , nail forming device  2  may be miniaturized. 
     Actuator  8  includes rectangular support frame  9 , rectangular movable frame  10  disposed on the inside of support frame  9 , rectangular movable unit  11  disposed on the inside of movable frame  10 , first vibration units  14 , and second vibration units  16 . Movable frame  10  is connected to support frame  9  by first vibration units  14 . A pair of first vibration units  14  is to twist around first rotation axis  13 . Movable unit  11  is connected to movable frame  10  by second vibration units  16 . Second vibration units  16  are to twist around second rotation axis  15  that is orthogonal to first rotation axis  13 . Additionally, first vibration units  14  are provided with first drive units  17 . First drive units  17  are connected to controller  6 . Twisting of first drive unit  17  is controlled by a control signal from controller  6 . Although not shown, first drive unit  17  has a laminate structure where a piezoelectric layer of PZT or the like is interposed between upper and lower electrodes made of Ti, Au or the like. By applying a potential difference between the upper and lower electrodes of first drive unit  17 , twisting of first vibration unit  14  around first rotation axis  13  is excited. 
     Like first vibration unit  14 , second vibration units  16  are provided with second drive units  18 . Second drive units  18  are connected to controller  6 . Twisting of second vibration unit  16  around second rotation axis  15  is excited by second drive unit  18 . 
     Mirror unit  12  is disposed on the surface of movable unit  11  of actuator  8  configured in the above manner, and reflection mirror  7  may scan light emitted by light source  4  in the directions of two axes. 
     &lt;Operation of Nail Forming Device  2 &gt; 
     Next, an operation of nail forming device  2  will be described with reference to  FIG. 1 . 
     Controller  6  controls light source  4  and optical drawing unit  5 . Controller  6  controls the amount of radiation and radiation time of light that is emitted by light source  4 , the angle of reflection of mirror unit  12  provided to actuator  8 , and the like. The surface of photo-curable resin  3  coating the surface of nail  1  is scanned by the light, and photo-curable resin  3  is partially cured. A drawing pattern is thus formed. 
     Additionally, as shown in  FIG. 3 , when forming a drawing pattern, if there is a density difference in the drawing pattern, pattern collapse is more likely to occur in an area where the drawing pattern is dense, compared to an area where the drawing pattern is rough. The cause of this pattern collapse is assumed to be blurring caused by diffusion of radiated light inside photo-curable resin  3 . Accordingly, if same control is performed for when a dense drawing pattern is to be formed and when a rough drawing pattern is to be formed, the following problem will occur. If a drawing condition suitable for a dense drawing pattern is set, and a rough drawing pattern is formed, the rough drawing pattern is not desirably formed due to lack of exposure. 
     However, with nail forming device  2 , which uses scanning reflection mirror  7  as described, above, light source  4  and optical drawing unit  5  are controlled by controller  6 , and photo-curable resin  3  may be partially cured. Unlike exposure with photomask, nail forming device  2  of the present exemplary embodiment may set a control condition for each section obtained by dividing a drawing area. Accordingly, even if there is a density difference in a drawing pattern, the control condition may be made different between a drawing area where a dense drawing pattern is to be formed and a drawing area where a rough drawing pattern is to be formed. That is, controller  6  may form an optimal drawing pattern by controlling light source  4  and optical drawing unit  5  according to the density of a drawing pattern. Formation of an optimal drawing pattern according to the density of a drawing pattern may be realized in the following manner. 
     The radiation time of light that is emitted by light source  4  on a drawing area on which a drawing pattern is to be formed is controlled by controller  6 . The radiation tune is determined for each section of the divided drawing area. 
     Also, the level of output of light that is emitted by light source  4  on the drawing area on which a drawing pattern is to be formed is controlled by controller  6 . The level of output of light is determined for each section of the drawing area. 
     Optimal control may be realized for each section obtained by division, by a combination of control conditions for the radiation tune of light and the level of output of light. 
     Also, in the case of performing control on a per section basis as described above, controller  6  has to perceive a drawing pattern. Thus, nail forming device  2  is desirably provided with communication unit  19  for obtaining a drawing pattern from outside. As communication unit  19 , a wired communication unit such as an USB, or a wireless communication unit such as a wireless LAN or Bluetooth (registered trademark) may be used. Additionally, in the present exemplary embodiment, a wireless LAN is used as communication unit  19 . 
     Moreover, with respect to a drawing pattern, a drawing pattern that is selected in advance by using a smartphone, a personal computer or the like is transferred to controller  6  by using a wireless LAN as communication unit  19 . If a drawing pattern is input to nail forming device  2  from outside, the latest designs may be easily introduced even if designs are frequently updated. Accordingly, a drawing pattern may be selected from a large number of designs. Depending on the situation, users may link together and form a community. 
     &lt;Details of Configuration of Nail Forming Device  2 &gt; 
     Nail forming device  2  desirably includes positioning unit  20  for determining the position of nail  1  on which drawing is to be performed. The present exemplary embodiment describes a guide for restricting the amount of insertion of a finger by causing the tip of nail  1  to come into contact with the guide, and for fixing the position of nail  1 . The method described above is not restrictive as long as the position of nail  1  may be fixed. Providing positioning unit  20  allows the position of nail I to be fixed, and therefore allows application of a detailed drawing. 
     As shown in  FIG. 4 , the surface of nail  1  has a convex curved shape. Accordingly, the radiation distance from reflection mirror  7  is different for edge part  1   a  and center part  1   b  of nail  1 . However, nail forming device  2  has a configuration where a semiconductor laser whose radiation light has high linearity is used as light source  4 , and where light with high linearity is radiated on nail  1  via reflection mirror  7 , and thus a variation in a beam spot diameter caused by a difference in the distance from light source is small, and deterioration of drawing accuracy on a curved surface is suppressed. Accordingly, highly detailed drawing is enabled. 
     Furthermore, angle of incidence θ 1  of light on tangent plane  1   c  of edge part  1   a  of curved nail  1  is smaller than angle of incidence θ 2  on tangent plane  1   d  of center part  1   b  of the nail, and thus the radiation area of light is greater at edge part  1   a  than at center part  1   b . Accordingly, the amount of received light per unit area is smaller at edge part la than at center part  1   b . Therefore, light output to edge part  1   a  of nail  1  is desirably made greater than light output to center part  1   b  of nail  1 . Besides using the method for performing adjustment based on the level of intensity of output light, adjustment may be performed by making the radiation time of light on edge part  1   a  longer than the radiation time of light on center part  1   b  of nail  1 . 
     Additionally, adjustment of the radiation time may be controlled by adjusting the displacement rate of the angle of reflection of reflection mirror  7 . However, it is difficult to finely adjust the angle of reflection. As a method for controlling the radiation time without controlling the angle of reflection, there is light emission control for the light source. The light control is control of the number of times the light source is switched on during a period of scanning of a unit area by light. If a semiconductor laser is used, the number of times of switching on may be controlled by controlling a clock signal for performing light emission control of the semiconductor laser. If the semiconductor laser is used as the light source, the radiation time may be easily adjusted. 
     Moreover, a case where a semiconductor laser with high light linearity is used as light source  4  has been described above with respect to nail forming device  2 , but a semiconductor light emitting element or a UV lamp whose radiation light is greatly diffused may alternatively be used as light source  4 . in the case where the semiconductor light emitting element or the UV lamp is used, light linearity of radiation light may be obtained by interposing a collimator lens (not shown) between light source  4  and reflection mirror  7 . If light linearity of radiation light may be obtained, the same effect as when a semiconductor laser is used may be achieved. 
     Furthermore, instead of using scanning reflection mirror  7  as described above as drawing means, a projection device such as a digital mirror device or a liquid crystal device may be used as scanning means. 
     Also, by providing storage unit  21  to controller  6 , and storing typical drawing patterns in advance in storage unit  21 , drawing may be performed based on stored drawing patterns. If controller  6  is provided with storage unit  21 , a drawing pattern may be selected without using communication unit  19 , and time may be reduced by the length of the transfer time for the drawing pattern. 
     Furthermore, to determine a control condition with respect to the curved shape of nail  1 , nail forming device  2  further includes nail detector  22  for detecting the three-dimensional shape of nail  1 , and controller  6  controls at least one of light source  4  and reflection mirror  7  according to first information detected by nail detector  22 . 
     Feedback control is enabled by inputting information (first information) detected by nail detector  22  to controller  6  as appropriate. Accordingly, correction control for the angle of reflection of reflection mirror  7  and a radiation tinning of light source  4  is enabled at nail forming device  2 . Additionally, nail detector  22  may be a camera that uses images or may use various methods including an optical method that uses light reflection, for example. By performing feedback control by using nail detector  22 , detailed drawing may be performed even if nail  1 , which is a drawing target, moves. 
     Furthermore, nail forming device  2  further includes light source output measurement unit  23  for measuring the level of output of light that is emitted by light source  4 , and controller  6  controls at least one of light source  4  and reflection mirror  7  according to second information that is measured by light source output measurement unit  23 . 
     By performing feedback control by information (second information) measured by light source output measurement unit  23 , nail forming device  2  may perform drawing with even higher accuracy. 
     Additionally, light source output measurement unit  23  may be configured from beam splitter  23   a  provided on an optical path and photodetector  23   b,  for example. 
     &lt;Nail Forming Method&gt; 
     A nail forming method that uses nail forming device  2  described above will be described with reference to  FIG. 5 . 
     First, a user coats the surface of his/her nail  1  on which the nail art is to be applied with photo-curable resin  3 , which is a nail material (resin-coating step S 1 ). In the resin-coating step, the entire nail is simply coated, and there is no need to form a drawing pattern by photo-curable resin  3 . 
     Next, a drawing pattern is selected, and control of the radiation position and the radiation time of light is performed by controller  6  according to the drawing pattern and feedback information such as the three-dimensional shape nail  1  and the level of output, and the photo-curable resin is partially cured at drawing area  3   a  (curing step S 2 ). Additionally, in the curing step, nail forming device  2  described with reference to  FIG. 1  is used, and controller  6  controls at least one of light source  4  and reflection mirror  7  according to the density of the drawing pattern. Control of the radiation time, the level of output of light and the like for nail forming device  2  is as described above, and description here is omitted. 
     Next, photo-curable resin  3  in non-cured area  3   b,  which is not ted with light and which is not cured, is removed (removal step S 3 ). A desired drawing pattern may be formed by the series of processes of resin-coating step S 1 , curing step S 2 , and removal step S 3 . 
     Also, if resin-coating step S 1 , curing step S 2 , and removal step  53  described above are repeatedly performed, a three-dimensional drawing pattern having a laminate structure may be formed. Also, by using a gel nail with differently colored layers, a colorful drawing pattern may be formed. 
     Moreover, since the curing wavelength is different depending on the type of photo-curable resin  3 , a plurality of light sources  4  with different wavelengths are desirably provided as light source  4 . At the time of control of light sources  4  by controller  6 , the control condition is desirably different for each of different waveforms. 
     Furthermore, in the exemplary embodiment described above, an example is described according to the case in which the nail art is applied on the surface of nail  1 , but the same effects may be obtained also when the nail art is applied on an artificial nail by nail forming device  2  of the present exemplary embodiment. 
     Still further, in the present exemplary embodiment, an example is described according to the case in which a user applies the nail art on his/her own nail  1  by nail forming device  2 , but nail forming device  2  may be installed at a nail salon, and a nail technician may use nail forming device  2  of the present exemplary embodiment. If nail forming device  2  of the present exemplary embodiment is used by nail technicians, the drawing accuracy may be prevented from being varied depending on the skill of each nail technician, or the application time may be reduced. 
     INDUSTRIAL APPLICABILITY 
     The nail forming device of the present invention may easily form a drawing pattern on nails or artificial nails. It is particularly advantageous in the case of a user forming a drawing pattern on his/her own nails. 
     REFERENCE MARKS IN THE DRAWINGS 
       1  Nail 
       2  Nail forming device 
       3  Photo-curable resin 
       3   a  Drawing area 
       3   b  Non-cured area 
       4  Light source 
       5  Optical drawing unit 
       6  Controller 
       7  Reflection mirror 
       8  Actuator 
       9  Support frame 
       10  Movable frame 
       11  Movable unit 
       12  Mirror unit 
       13  First rotation axis 
       14  First vibration unit 
       15  Second rotation axis 
       16  Second vibration unit 
       19  Communication unit 
       20  Positioning unit 
       21  Storage unit 
       22  Nail detector 
       23  Light source output measurement unit 
       23   a  Beam splitter 
       23   b  Photodetector