Abstract:
A beauty instrument capable of imparting a massaging effect to skin. A beauty instrument is configured such that a pair of balls is supported at the tip of a handle. The balls are positioned at a distance from each another, and are capable of rotating around respective axes thereof.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a beauty instrument that is capable of massaging the skin of the face, arms, other body parts, with massage balls installed on a handle, thereby promoting blood flow and achieving beautiful skin. 
       BACKGROUND OF THE INVENTION 
       [0002]    Conventionally, this type of beauty instrument has been proposed in various forms. For example, Patent Document 1 has disclosed a skin treatment roller device. That is, the skin treatment roller device is provided with a shaft and a pair of rollers installed on one end of the shaft, and the rollers are set so that each of the rotation axes thereof forms an acute angle with respect to the centerline of the shaft in the longitudinal direction. Further, the angle formed between the rotation axes of the rollers is an obtuse angle. When the shaft of the skin treatment roller device is gripped by hand and the rollers are pressed against the skin in one direction, the skin is pulled to open pores. When the rollers are pulled in the opposite direction with the rollers being pressed, the skin is pinched between the rollers to contract the pores. Therefore, the skin treatment roller device is able to remove dirt of pores efficiently. 
       PRIOR ART DOCUMENT 
     Patent Document 
       [0003]    Patent Document 1: Japanese Laid-Open Patent Publication No. 2009-142509 
       SUMMARY OF THE INVENTION 
     Problems that the Invention is to Solve 
       [0004]    However, in the skin treatment roller device with a conventional configuration disclosed in Patent Document 1, the centerline of the shaft lies in the same plane as the rotation axes of the rollers (refer to FIG. 2 in Patent Document 1). Thus, when the shaft of the skin treatment roller device is gripped by hand to press the rollers against the skin, it is necessary to raise the elbow and bend the wrist so that the hand will be oriented toward the skin, and the shaft must stand upright with respect to the skin. Therefore, the skin treatment roller device not only operates poorly but also undergoes a great change in the state of actions of the rollers on the skin depending on the angle of the wrist. 
         [0005]    Further, each roller of the skin treatment roller device is formed in the shape of an oval tube. Thus, when the roller device is pressed in one direction, the skin is pressed uniformly over a wide range, thus resulting in insufficient opening of pores. Still further, when the roller device is pulled in the opposite direction, the skin positioned between the rollers is pulled at a region equivalent to the length of the rollers and the skin is less likely to be strongly held between the rollers. As a result, pores are not sufficiently opened or contracted and dirt in the pores is not cleanly removed. In addition, since each roller is formed in the shape of an oval tube, the roller is in line contact with the skin to give a great resistance to the skin and does not move smoothly. Moreover, the roller device is likely to be restricted in the direction in which it moves. Therefore, the skin treatment roller device operates poorly. 
         [0006]    Accordingly, it is an objective of the present invention to provide a beauty instrument that is capable of giving an excellent massaging effect to the skin, also giving prominent pressing and squeezing effects to the skin continuously and operates well. 
       Means for Solving the Problems 
       [0007]    To achieve the foregoing objective and in accordance with the present invention, a beauty instrument is provided that includes a pair of balls, which are supported at a tip portion of a handle and located at a distance from each other, wherein each ball is rotational freely about an axis. The beauty instrument is characterized in that the axis of each ball is configured to tilt forward with respect to a centerline of the handle such that the axis of the ball is able to keep a certain angle with respect to the surface of the skin during reciprocating motion of the beauty instrument. 
       Effects of the Invention 
       [0008]    The beauty instrument of the present invention is able to provide the following effects. 
         [0009]    A pair of balls is supported at the tip portion of a handle to rotate freely about the axis thereof, with a distance there between, and the axis of each ball is configured to tilt forward with respect to the centerline of the handle. That is, the axis of each ball is able to keep a certain angle with respect to the surface of the skin during reciprocating motion of the beauty instrument. Therefore, when the handle is gripped and the balls are allowed to be in contact with the skin, it is not necessary to bend the wrist. The skin can be pressed when the beauty instrument is moved forward with the wrist kept straight. The skin can be squeezed when the beauty instrument is moved backward. 
         [0010]    Further, since the part in contact with the skin is not configured with a tubular roller but with a spherical-shaped ball, the balls are partially in contact with the skin. Therefore, the balls are able to exert a pressing force and a squeezing force to the skin locally in a concentrated manner. The instrument allows the balls to move smoothly with respect to the skin and also high in freedom of movement in any direction. 
         [0011]    Accordingly, the beauty instrument of the present invention is able to give an excellent massaging effect to the skin and to provide prominent pressing and squeezing effects on the skin continuously. The instrument also can be operated easily. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view showing a beauty instrument according to one embodiment of the present invention; 
           [0013]      FIG. 2  is a plan view showing the beauty instrument; 
           [0014]      FIG. 3  is a front view showing a use condition of the beauty instrument; 
           [0015]      FIG. 4  is a left side view showing the beauty instrument; 
           [0016]      FIG. 5  is a plan view showing a state in which a plane including axes of the balls of the beauty instrument is horizontal; 
           [0017]      FIG. 6  is a longitudinal cross-sectional view showing the beauty instrument; 
           [0018]      FIG. 7  is a cross-sectional view showing a rotation mechanism of the ball of the beauty instrument; 
           [0019]      FIG. 8  is a left side view showing a beauty instrument according to a modification; and 
           [0020]      FIG. 9  is a front view showing the ball of the beauty instrument of the modification. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    A beauty instrument according to one embodiment of the present invention will be described with reference to  FIGS. 1 to 7 . 
         [0022]    As shown in  FIG. 1 , a beauty instrument  10  of the present embodiment includes a handle  11 , which has bifurcated portions  11   a  at the tip. The bifurcated portions  11   a  extend in a Y-letter shape in a plan view. As shown in  FIG. 6 , the handle  11  is configured with an electric insulating base  12 , which is made of a plastic such as ABS plastic, and a handle cover  13 , which is composed of an upper handle cover  13   a  and a lower handle cover  13   b  covering the outer circumference of the base  12 . Each of the upper handle cover  13   a  and the lower handle cover  13   b  is made of a plastic and plated on an outer surface thereof to be electrically conductive. The handle covers  13  are coupled to the base  12  with screws  14 . 
         [0023]    As shown in  FIG. 7 , a pair of supporting tubes  16  is formed integrally with the base  12  at the bifurcated portions  11   a  of the handle  11 . A metal ball supporting shaft  15  is supported on each supporting tube  16 . A cylindrical cap  18  made of a plastic is fitted and attached to the tip outer circumference of each bifurcated portion  11   a  of the handle  11 . Due to the thus fitted and attached cap  18 , the tip of the bifurcated portion  11   a  is sealed, the ball supporting shaft  15  is prevented from loosening. Also, electric insulation is ensured between electrically conductive portions, that is, between the outer surface of the bifurcated portion  11   a  and the outer surface of a ball  17 , which will be described below. 
         [0024]    A cylindrical bearing member  19 , which is made of a plastic and metal-plated on the inner circumference and the outer circumference thereof, is fitted to a protruding end of the ball supporting shaft  15  and fixed by a stop ring  25  so as not to be removed. A pair of elastically deformable stoppers  19   a  protrudes on the outer circumference of the bearing member  19 . The spherical ball  17  is inserted and supported by the bearing member  19  on the ball supporting shaft  15  to rotate freely. The ball  17  is configured with a core material  26 , which is made of a plastic, a cap material  27 , which is made of a plastic and fitted and attached on a tip inner circumference of the core material  26 , and a shell material  28 , which is made of a plastic and formed to cover the outer circumference of the core material  26 . 
         [0025]    The outer surface of the shell material  28  is metal-plated to be electrically conductive as an electrically conductive portion and electrically connected to the metal-plated bearing member  19 . A step portion  26   a  is formed on an inner circumference of the core material  26 . The step portion  26   a  can be engaged with the stoppers  19   a  of the bearing member  19 . Then, the stoppers  19   a  are engaged with the step portion  26   a  in a state in which the ball  17  is fitted about the bearing member  19 , and the ball  17  is kept so as not to be removed from the bearing member  19 . Further, as shown in  FIGS. 3 and 4 , many faces  17   a , which stimulate tissues of the skin  20 , are formed on the outer circumferential surface of each of the balls  17 . 
         [0026]    A permanent magnet  22  for generating electric power in association with rotation of the ball  17  is located inside each of the balls  17   a . The permanent magnet  22  is made of magnetic steel in a cylindrical shape and configured to rotate in an integral manner with the ball  17 . As the ball  17  rotates, the permanent magnet  22  rotates relative to the ball supporting shaft  15  with a slight distance in between. Thereby, a micro electric power is generated due to very small irregularities on the surface of the ball supporting shaft  15  and slight deviation of roundness, and the micro electric power is transmitted to the electrically conductive portion of the outer circumferential surface of the ball  17 . 
         [0027]    As shown in  FIGS. 2 and 6 , a transparent plate  23  is installed on the tip of the handle  11 , in other words, at the root of the bifurcated portions  11   a . A solar cell panel  24  is installed inside the transparent plate  23 . An output terminal (not illustrated) of the solar cell panel  24  is connected to electrically conductive portions of the handle  11  and the balls  17 . Therefore, electricity generated at the solar cell panel  24  is supplied to the electrically conductive portions of the handle  11  and the balls  17 . As a result, when the beauty instrument  10  is used, electricity generated at the solar cell panel  24  between the handle  11  and the balls  17  runs through the human body, thereby making it possible to provide cosmetic effects. 
         [0028]    As described previously, the beauty instrument  10  of the present embodiment can be applied to the face and also can be applied to other parts of the body such as the neck, arms and legs. 
         [0029]    As shown in  FIG. 3 , the axis of the ball supporting shaft  15  is configured to tilt forward with respect to the centerline x of the handle  11  such that the axis of the ball supporting shaft  15  can keep a certain angle with respect to the surface of the skin  20  while the beauty instrument  10  is in reciprocating motion. More specifically, a lateral projection angle α of an axis y of the ball  17 , that is, an axis y of the ball supporting shaft  15  with respect to the centerline x (a line parallel with a line that divides an angle between outer circumferential tangent lines z of the thickest part of the handle  11 ) of the handle  11  is preferably from 90 degrees to 110 degrees in order that the ball  17  tilts forward with respect to the centerline x of the handle  11  to improve operability. It is more preferable that the lateral projection angle α is from 93 degrees to 100 degrees. It is most preferable that the angle is from 95 degrees to 99 degrees. If the lateral projection angle α is less than 90 degrees and if it is greater than 110 degrees, the ball supporting shaft  15  tilts forward to an excessively lesser or greater extent. Thus, when the balls  17  are in contact with the skin  20 , it is necessary to raise or lower the elbow or widely bend the wrist. As a result, the beauty instrument  10  is poor in operability and also it is difficult to adjust the angle of the ball supporting shaft  15  with respect to the surface of the skin  20 . 
         [0030]    As shown in  FIG. 5 , the opening angle between the balls  17 , that is, an opening angle β between the ball supporting shafts  15  is set preferably from 50 degrees to 110 degrees, more preferably from 50 degrees to 90 degrees, and particularly preferably from 65 degrees to 80 degrees in order that reciprocating motion of the balls  17  gives a favorable pressing effect and a squeezing effect to the skin  20 . If the opening angle β is less than 50 degrees, there is a tendency that the squeezing effect given to the skin  20  is excessively strong and this is not favorable. On the other hand, if the opening angle β is in excess of 110 degrees, the skin  20  positioned between the balls  17  is squeezed with difficulty, and this is not favorable either. 
         [0031]    Further, a diameter L of each of the balls  17  is preferably set from 15 mm to 60 mm, more preferably from 32 mm to 55 mm, and particularly preferably from 38 mm to 45 mm in order that the beauty instrument  10  is applied mainly to the face and arms. If the diameter L of the ball  17  is smaller than 15 mm, the pressing effect and the squeezing effect are provided at a smaller range of the skin  20 , and this is not favorable. On the other hand, if the diameter L of the ball  17  is greater than 60 mm, the ball  17  is dimensionally large in relation to the face and arms. Thus, it is difficult for the instrument to press or squeeze a narrow part and is poor in usability. 
         [0032]    Still further, a distance D between the outer circumferential surfaces of the balls  17  is preferably from 8 mm to 25 mm, more preferably from 9 mm to 15 mm, and particularly preferably from 10 mm to 13 mm in order that the skin  20  is squeezed in an appropriate manner in particular. If the distance D between the outer circumferential surfaces of the balls  17  is less than 8 mm, the squeezing effect is given too strongly to the skin  20  positioned between the balls  17  and this is not favorable. On the other hand, if the distance D between the outer circumferential surfaces of the balls  17  is in excess of 25 mm, it is difficult to squeeze the skin  20  positioned between the balls  17 , and this is not favorable either. 
         [0033]    Next, operation of the beauty instrument  10  of the embodiment which is configured as described above will be described. 
         [0034]    When the beauty instrument  10  is used, as shown in  FIG. 3 , a user presses the outer circumferential surfaces of the balls  17 , while gripping the handle  11 , and causes the balls  17  to contact the skin  20  such as the face and arms as shown in an alternate long and two short dashed line shown in  FIG. 3 , and moves the instrument forward in a direction moving from the base end of the handle  11  to the tip thereof (the leftward direction in  FIG. 3 ). Then, the balls  17  are rotated about the ball supporting shafts  15 . At this time, as shown in the alternate long and two short dashed line in  FIG. 3 , a pressing force is applied to the skin  20  from the balls  17 . When the instrument is moved backward so that the balls  17  are returned to original positions after forward movement of the balls  17 , the skin  20  positioned between the balls  17  is squeezed in association with rotation of the balls  17  as shown in the alternate long and two short dashed line in  FIG. 4 . 
         [0035]    That is, as shown in  FIG. 5 , when the balls  17  are moved forward in a direction of arrows P1, each of the balls  17  is rotated in a direction of arrows P2. Therefore, the skin  20  is pressed and stretched. On the other hand, when the balls  17  are moved backward in a direction of arrows Q1, each of the balls  17  is rotated in a direction of arrows Q2. Therefore, the skin  20  positioned between the balls  17  is squeezed to be wound up. The balls  17  press the skin  20  during forward movement, by which the skin  20  between the balls  17  is squeezed as a reaction of the pressing force thereof. 
         [0036]    In this case, the ball supporting shafts  15  tilt forward with respect to the centerline x of the handle  11 . More specifically, the lateral projection angle α of the ball supporting shafts  15  with respect to the centerline x of the handle  11  is set from 90 degrees to 110 degrees. Thus, it is possible to reciprocate the beauty instrument  10  without raising the elbow or bending the wrist too much. Further, the beauty instrument can be operated continuously such that the axes y of the ball supporting shafts  15  are kept substantially at a right angle with respect to the surface of the skin  20 . As a result, the balls  17  are efficiently pressed against the skin  20 , thus making it possible to provide an efficient massage effect. 
         [0037]    Still further, a part in contact with the skin  20  is configured not with conventional tubular rollers but with the spherical balls  17 . The balls  17  are in contact with the skin  20  at an area smaller than that of the rollers. Therefore, the balls  17  are able to exert a pressing force and a squeezing force to the skin  20  locally in a concentrated manner. Further, the balls  17  are able to move smoothly with respect to the skin  20  and also to change a moving direction easily. 
         [0038]    Therefore, due to a pressing force in association with rotation of the balls  17 , the skin  20  such as the face and arms is massaged to promote blood flow at the massaged part and also promote circulation of lymphatic fluid. Further, the opening angle β between the balls  17  is set from 50 degrees to 110 degrees and the distance D between the outer circumferential surfaces of the balls  17  is set from 8 mm to 25 mm. It is, therefore, possible to apply an appropriate pressing force to a desired site of the skin  20  and also to squeeze the skin  20  not excessively strong or not excessively weak, in a comfortable manner. Still further, the diameter L of the ball  17  is set from 15 mm to 60 mm. Thus, the beauty instrument  10  is able to massage the face and arms in an appropriate manner and also operated quickly. Therefore, a lift massage can be given, for example, to a loosened part of the skin  20 , as desired. 
         [0039]    In addition, when the skin  20  is pulled by a pressing force of the balls  17 , pores are opened, and when the skin  20  is squeezed between the balls  17 , the pores are contracted to remove dirt inside the pores. Further, the skin  20  of the user is in contact with the outer circumferential surfaces of the balls  17  and the hand of the user is also in contact with an electrically conductive portion on the surface of the handle  11 . Therefore, due to electricity generated by the solar cell panel  24 , as shown in  FIG. 3 , weak electric current flows from the balls  17  to the skin  20  via the hand of the user, thereby stimulating the skin  20  to promote blood flow and circulation of lymphatic fluid. Thus, the massaging actions, pressing/squeezing actions, lift-up actions, actions of removal of dirt inside pores, electrically stimulating actions are applied to the skin  20  in a synergistic and comprehensive manner, thereby giving desirable skin treatment effects to the skin. 
         [0040]    Therefore, according to the present embodiment, the following advantages are obtained. 
         [0041]    (1) In the beauty instrument  10  of the present embodiment, the balls  17  are arranged at a distance and supported to rotate about the axis y. The lateral projection angle α of the axis y of each ball  17  with respect to the centerline x of the handle  11  is set from 90 degrees to 110 degrees such that the ball supporting shaft  15  tilts forward with respect to the centerline x of the handle  11 . That is, since the axis y of the ball  17  tilts forward with respect to the centerline x of the handle  11 , it is not necessary to raise the elbow or bend the wrist greatly, when bringing the balls  17  into contact with the skin  20  while gripping the handle  11 . As a result, the user is able to press and squeeze the skin  20  by easily reciprocating the beauty instrument  10 . 
         [0042]    Further, the part in contact with the skin  20  is configured with the spherical-shaped balls  17 . It is, thus, possible to apply the pressing force and the squeezing force to a desired part of the skin  20  in a concentrated manner. The balls  17  are also allowed to move smoothly with respect to the skin  20  and also high in freedom of movement in any direction. 
         [0043]    Therefore, according to the beauty instrument  10  of the present embodiment, that not only is an excellent massaging effect given to the skin  20  but also prominent pressing and squeezing effects are given to the skin  20  continuously and the instrument is excellent in operability. 
         [0044]    (2) The lateral projection angle α of the axis y of the ball  17  is preferably from 93 degrees to 100 degrees and more preferably from 95 degrees to 99 degrees. Therefore, it is possible to improve operability of the beauty instrument  10  and cosmetic effects such as massaging effect to a greater extent. 
         [0045]    (3) The opening angle β between the balls  17  is preferably from 50 degrees to 110 degrees, more preferably from 50 degrees to 90 degrees, and particularly preferably from 65 degrees to 80 degrees. Therefore, it is possible to improve a pressing effect and a squeezing effect of the beauty instrument  10  drastically. 
         [0046]    (4) The diameter L of the ball  17  is preferably from 15 mm to 60 mm, more preferably from 32 mm to 55 mm, and particularly preferably from 38 mm to 45 mm. Therefore, the beauty instrument  10  can be applied favorably to the face and arms. It is possible to improve the massaging effect and operability of the instrument. 
         [0047]    (5) The distance D between the outer circumferential surfaces of the balls  17  is preferably from 8 mm to 25 mm, more preferably from 9 mm to 15 mm, and particularly preferably from 10 mm to 13 mm. Therefore, it is possible to apply an appropriate pressing effect to a desired site of the skin  20 . Also the skin  20  can be squeezed comfortably with an appropriate strength. 
         [0048]    (6) In the beauty instrument  10 , the power source is composed of the solar cell panel  24  installed on the handle  11 . Therefore, it is not necessary to install a power source such as a dry cell. Weak electric current is allowed to flow from the balls  17  to the skin  20  by using electricity generated at the solar cell panel  24 . 
         [0049]    (7) The permanent magnet  22  for generating electricity in association with rotation of the balls  17  is provided in the beauty instrument  10  of the present embodiment. Thus, micro electric power can be obtained by rotation of the balls  17  and the micro electric power thereof is able to impart weak electric current from the balls  17  to the skin  20 . 
       EXAMPLES 
       [0050]    Hereinafter, a more specific description will be given of the previously described embodiment with reference to examples. 
       Examples 1 to 6 
     Evaluation of Lateral Projection Angle α 
       [0051]    In the beauty instrument  10  of the previously described embodiment, which is applicable to both the face and the body, the lateral projection angle α was evaluated while changing the angle α from 90 degrees to 110 degrees under the condition where the opening angle β between the balls  17  was set to be 70 degrees, the diameter L of the ball  17  was set to be 40 mm, and the distance D between the outer circumferential surfaces of the balls  17  was set to be 11 mm. That is, the beauty instrument  10  was applied to body parts such as the face, arms and neck, thereby carrying out a sensory evaluation for feeling during use. 
         [0052]    The sensory evaluation was conducted using the following procedures. That is, ten persons evaluated the feeling during use of the beauty instrument  10 . When eight or more of them evaluated the feeling during use to be good, “A” was given, when five to seven of them evaluated the feeling during use to be good, “B” was given, when three or four of them evaluated the feeling during use to be good, “C” was given, and when two or less of them evaluated the feeling during use to be good, “D” was given. 
         [0053]    Table 1 shows the results. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                 Lateral projection angle: 
                   
               
               
                   
                   
                 α 
                   
               
               
                   
                   
                 (degrees) 
                 Evaluation 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Example 1 
                 90 
                 C 
               
               
                   
                 Example 2 
                 93 
                 B 
               
               
                   
                 Example 3 
                 97 
                 A 
               
               
                   
                 Example 4 
                 99 
                 A 
               
               
                   
                 Example 5 
                 100 
                 B 
               
               
                   
                 Example 6 
                 110 
                 C 
               
               
                   
                   
               
             
          
         
       
     
         [0054]    As shown in Table 1, the best results were obtained in Example 3, where the lateral projection angle α was 97 degrees, and in Example 4, where it was 99 degrees. Then, better results were obtained in Example 2, where the lateral projection angle α was 93 degrees, and in Example 5, where it was 100 degrees. Further, results of Example 1, where the lateral projection angle α was 90 degrees, and those of Example 6, where it was 110 degrees, were also judged to be acceptable. 
         [0055]    Therefore, the lateral projection angle α of the beauty instrument  10  was preferably in a range from 90 degrees to 110 degrees and more preferably in a range from 93 degrees to 100 degrees. 
       Examples 7 to 15 
     Evaluation of Opening Angle β 
       [0056]    Evaluation was conducted for the opening angle β of a beauty instrument  10  that was suitable for both the face and the body. That is, the opening angle β was evaluated while changing the opening angle β from 40 degrees to 120 degrees under the condition where the lateral projection angle α of the beauty instrument  10  was set to be 97 degrees, the diameter L of the ball  17  was set to be 40 mm, and the distance D between the outer circumferential surfaces of the balls  17  was set to be 11 mm. The evaluation was conducted in the same way as that of the previously described Example 1. Table 2 shows the thus obtained results. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                   
                 Opening angle: β 
                   
               
               
                   
                   
                 (degrees) 
                 Evaluation 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Example 7 
                 40 
                 C 
               
               
                   
                 Example 8 
                 50 
                 B 
               
               
                   
                 Example 9 
                 55 
                 B 
               
               
                   
                 Example 10 
                 60 
                 B 
               
               
                   
                 Example 11 
                 70 
                 A 
               
               
                   
                 Example 12 
                 90 
                 B 
               
               
                   
                 Example 13 
                 100 
                 B 
               
               
                   
                 Example 14 
                 110 
                 B 
               
               
                   
                 Example 15 
                 120 
                 C 
               
               
                   
                   
               
             
          
         
       
     
         [0057]    As shown in Table 2, the best result was obtained in Example 11, where the opening angle β was 70 degrees. Then, better results were obtained in Example 8 to Example 10, where the opening angle β was 50 degrees to 60 degrees and in Example 12 to Example 14, where it was 90 degrees to 110 degrees. Further, results of Example 7, where the opening angle β was 40 degrees and those of Example 15, where it was 120 degrees were also judged to be acceptable. 
         [0058]    Therefore, the opening angle β of the beauty instrument  10  was judged to be preferable in a range from 50 degrees to 110 degrees and most preferable in a range from 65 degrees to 80 degrees. 
       Example 16 to Example 23 
     Evaluation of Diameter L of Ball  17   
       [0059]    Evaluation was conducted for the diameter L of the ball  17  of a beauty instrument  10  that was suitable for both the face and the body. That is, the diameter L of the ball  17  was evaluated while changing the diameter L from 20 mm to 40 mm under conditions where the lateral projection angle α of the beauty instrument  10  was set to be 97 degrees, the opening angle θ between the balls  17  was set to be 70 degrees, and the distance D between the outer circumferential surfaces of the balls  17  was set to be 11 mm. The evaluation was conducted in the same way as that of the previously described Example 1. Table 3 shows the thus obtained results. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                 TABLE 3 
               
               
                   
                   
               
               
                   
                   
                 Diameter of ball: L 
                   
               
               
                   
                   
                 (mm) 
                 Evaluation 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Example 16 
                 20 
                 C 
               
               
                   
                 Example 17 
                 25 
                 C 
               
               
                   
                 Example 18 
                 27.5 
                 C 
               
               
                   
                 Example 19 
                 30 
                 C 
               
               
                   
                 Example 20 
                 32.5 
                 C 
               
               
                   
                 Example 21 
                 35 
                 B 
               
               
                   
                 Example 22 
                 38.3 
                 A 
               
               
                   
                 Example 23 
                 40 
                 A 
               
               
                   
                   
               
             
          
         
       
     
         [0060]    As shown in Table 3, the best results were obtained in Example 22, where the diameter L of the ball  17  was 38.3 mm, and in Example 23, where it was 40 mm. Then, better results were obtained in Example 21, where the diameter L of the ball  17  was 35 mm. Further, results of Examples 16 to 20, where the diameter L of the ball  17  was from 20 mm to 32.5 mm were also judged to be acceptable. 
         [0061]    Therefore, the diameter L of the ball  17  of the beauty instrument  10  was judged to be preferable in a range from 20 mm to 40 mm, more preferable in a range from 35 mm to 40 mm, and most preferable in a range from 38.3 mm to 40 mm. 
       Examples 24 to 28 
     Evaluation of the Distance D Between the Outer Circumferential Surfaces of the Balls  17   
       [0062]    Evaluation was conducted for the distance D between the outer circumferential surfaces of the balls  17  in a beauty instrument  10  that was suitable for both the face and the body. That is, the distance D between the outer circumferential surfaces of the balls  17  was evaluated while changing the distance D from 8 mm to 15 mm under the condition where the lateral projection angle α of the beauty instrument  10  was set to be 97 degrees, the opening angle β between the balls  17  was set to be 70 degrees, and the diameter L of the ball  17  was set to be 40 mm. The evaluation was conducted in the same way as that of the previously described Example 1. Table 4 shows the thus obtained results. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                 TABLE 4 
               
               
                   
                   
               
               
                   
                   
                 Distance between balls: 
                   
               
               
                   
                   
                 D  
                   
               
               
                   
                   
                 (mm) 
                 Evaluation 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Example 24 
                 8 
                 C 
               
               
                   
                 Example 25 
                 10 
                 B 
               
               
                   
                 Example 26 
                 11 
                 A 
               
               
                   
                 Example 27 
                 12 
                 B 
               
               
                   
                 Example 28 
                 15 
                 C 
               
               
                   
                   
               
             
          
         
       
     
         [0063]    As shown in Table 4, the best result was obtained in Example 26, where the distance D between the outer circumferential surfaces of the balls  17  was 11 mm. Then, better results were obtained in Example 25, where the distance D between the outer circumferential surfaces of the balls  17  was 10 mm and in Example 27, where the distance D was 12 mm. Further, results of Example 24, where the distance D between the outer circumferential surfaces of the balls  17  was 8 mm and those of Example 28, where it was 15 mm were also judged to be acceptable. 
         [0064]    Therefore, the distance D between the outer circumferential surfaces of the balls  17  of the beauty instrument  10  was judged to be preferable in a range from 8 mm to 15 mm, and more preferable in a range from 10 mm to 12 mm. 
       Examples 29 to 38 
     Evaluation of Diameter L of the Ball  17   
       [0065]    Evaluation was conducted for the diameter L of the ball  17  in a beauty instrument  10  that was mainly suitable for the face. That is, the diameter L of the ball  17  was evaluated while changing the diameter L from 15 mm to 40 mm under the condition where the lateral projection angle α of the beauty instrument  10  was set to be 97 degrees, the opening angle β between the balls  17  was set to be 70 degrees, and the distance D between the outer circumferential surfaces of the balls  17  was set to be 11 mm. The evaluation was conducted in the same way as that of Example 1. Table 5 shows the thus obtained results. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                 TABLE 5 
               
               
                   
                   
               
               
                   
                   
                 Diameter of the ball: L 
                   
               
               
                   
                   
                 (mm) 
                 Evaluation 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Example 29 
                 15 
                 B 
               
               
                   
                 Example 30 
                 17 
                 B 
               
               
                   
                 Example 31 
                 20 
                 B 
               
               
                   
                 Example 32 
                 25 
                 A 
               
               
                   
                 Example 33 
                 27.5 
                 A 
               
               
                   
                 Example 34 
                 30 
                 B 
               
               
                   
                 Example 35 
                 32.5 
                 C 
               
               
                   
                 Example 36 
                 35 
                 C 
               
               
                   
                 Example 37 
                 38.3 
                 C 
               
               
                   
                 Example 38 
                 40 
                 C 
               
               
                   
                   
               
             
          
         
       
     
         [0066]    As shown in Table 5, in the case of the beauty instrument  10  for the face, the best results were obtained in Example 32, where the diameter L of the ball  17  was 25 mm, and in Example 33, where it was 27.5 mm. Then, better results were obtained in Examples 29 to 31, where the diameter L of the ball  17  was from 15 mm to 20 mm and in Example 34, where the diameter L of the ball  17  was 30 mm. Further, results of Examples 35 to 38, where the diameter L of the ball  17  was from 32.5 mm to 40 mm were also judged to be acceptable. 
         [0067]    Therefore, when the beauty instrument  10  was suitable for the face, the diameter L of the ball  17  was judged to be preferable in a range from 15 mm to 40 mm and more preferable in a range from 15 mm to 30 mm. 
       Examples 39 to 44 
     Evaluation of the Distance D Between the Outer Circumferential Surfaces of Balls  17   
       [0068]    Evaluation was conducted for the distance D between the outer circumferential surfaces of the balls  17  in a beauty instrument  10  that was mainly suitable for the face. That is, the distance D between the outer circumferential surfaces of the balls  17  was evaluated while changing the distance D from 6 mm to 15 mm under the condition where the lateral projection angle α of the beauty instrument  10  was set to be 97 degrees, the opening angle β between the balls  17  was set to be 70 degrees, and the diameter L of the ball  17  was set to be 40 mm. The evaluation was conducted in the same way as that of the previously described Example 1. Table 6 shows the thus obtained results. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                 TABLE 6 
               
               
                   
                   
               
               
                   
                   
                 Distance between balls: 
                   
               
               
                   
                   
                 D 
                   
               
               
                   
                   
                 (mm) 
                 Evaluation 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Example 39 
                 6 
                 C 
               
               
                   
                 Example 40 
                 8 
                 B 
               
               
                   
                 Example 41 
                 10 
                 B 
               
               
                   
                 Example 42 
                 11 
                 A 
               
               
                   
                 Example 43 
                 12 
                 B 
               
               
                   
                 Example 44 
                 15 
                 C 
               
               
                   
                   
               
             
          
         
       
     
         [0069]    As shown in Table 6, when the beauty instrument  10  was for the face, the best result was obtained in Example 42, where the distance D between the outer circumferential surfaces of the balls  17  was 11 mm. Then, better results were obtained in Example 40, where the distance D between the outer circumferential surfaces of the balls  17  was 8 mm, in Example 41, where the distance D was 10 mm and in Example 43, where it was 12 mm. Further, results of Example 39, where the distance D between the outer circumferential surfaces of the balls  17  was 6 mm and those of Example 44, where it was 15 mm were also judged to be acceptable. 
         [0070]    Therefore, when the beauty instrument  10  was for the face, the distance D of the outer circumferential surfaces of the balls  17  was judged to be preferable in a range from 6 mm to 15 mm and more preferable in a range from 8 mm to 12 mm. 
       Examples 45 to 51 
     Evaluation of the Diameter L of the Ball  17   
       [0071]    Evaluation was conducted for the diameter L of the ball  17  in a beauty instrument  10  that was mainly suitable for the body. That is, the diameter L of the ball  17  was evaluated while changing the diameter L from 30 mm to 60 mm under the conditions where the lateral projection angle α of the beauty instrument  10  was set to be 97 degrees, the opening angle β between the balls  17  was set to be 70 degrees, and the distance D between the outer circumferential surfaces of the balls  17  was set to be 11 mm. The evaluation was conducted in the same way as that of the previously described Example 1. Table 7 shows the thus obtained results. 
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                 TABLE 7 
               
               
                   
                   
               
               
                   
                   
                 Diameter of ball: L 
                   
               
               
                   
                   
                 (mm) 
                 Evaluation 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Example 45 
                 30 
                 C 
               
               
                   
                 Example 46 
                 32.5 
                 C 
               
               
                   
                 Example 47 
                 35 
                 C 
               
               
                   
                 Example 48 
                 38.3 
                 B 
               
               
                   
                 Example 49 
                 40 
                 B 
               
               
                   
                 Example 50 
                 50 
                 A 
               
               
                   
                 Example 51 
                 60 
                 A 
               
               
                   
                   
               
             
          
         
       
     
         [0072]    As shown in Table 7, the best results were obtained in Example 50, where the diameter L of the ball  17  was 50 mm, and in Example 51, where it was 60 mm. Then, better results were obtained in Example 48, where the diameter L of the ball  17  was 38.3 mm, and in Example 49, where the diameter L of the ball  17  was 40 mm. Further, results of Examples 45 to 47, where the diameter L of the ball  17  was from 30 mm to 35 mm were also judged to be acceptable. 
         [0073]    Therefore, when the beauty instrument  10  was for the body, the diameter L of the ball  17  was judged to be preferable in a range from 30 mm to 60 mm and more preferable in a range from 38.3 mm to 60 mm. 
       Examples 52 to 58 
     Evaluation of the Distance D Between the Outer Circumferential Surfaces of the Balls  17   
       [0074]    Evaluation was conducted for the distance D of the outer circumferential surfaces of the balls  17  in a beauty instrument  10  that was mainly suitable for the body. That is, the distance D between the outer circumferential surfaces of the balls  17  was evaluated while changing the distance D from 8 mm to 25 mm under the condition where the lateral projection angle α of the beauty instrument  10  was set to be 97 degrees, the opening angle β between the balls  17  was set to be 70 degrees, and the diameter L of the ball  17  was set to be 40 mm. The evaluation was conducted in the same way as that of the previously described Example 1. Table 8 shows the thus obtained results. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                 TABLE 8 
               
               
                   
                   
               
               
                   
                   
                 Distance between balls: 
                   
               
               
                   
                   
                 D 
                   
               
               
                   
                   
                 (mm) 
                 Evaluation 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Example 52 
                 8 
                 C 
               
               
                   
                 Example 53 
                 10 
                 B 
               
               
                   
                 Example 54 
                 11 
                 B 
               
               
                   
                 Example 55 
                 12 
                 A 
               
               
                   
                 Example 56 
                 15 
                 A 
               
               
                   
                 Example 57 
                 20 
                 B 
               
               
                   
                 Example 58 
                 25 
                 B 
               
               
                   
                   
               
             
          
         
       
     
         [0075]    As shown in Table 8, the best results were obtained in Example 55, where the distance D between the outer circumferential surfaces of the balls  17  was 12 mm, and in Example 56, where it was 15 mm. Then, better results were obtained in Example 53 and Example 54, where the distance D between the outer circumferential surfaces of the balls  17  was from 10 mm to 11 mm, and in Example 57 and Example 58, where it was 20 mm to 25 mm. Further, the result of Example 52, where the distance D of the outer circumferential surfaces of the balls  17  was 8 mm, was also judged to be acceptable. 
         [0076]    Therefore, when the beauty instrument  10  was for the body, the distance D between the outer circumferential surfaces of the balls  17  was judged to be preferable in a range from 8 mm to 25 mm and more preferable in a range from 10 mm to 25 mm. 
         [0077]    With the comprehensive evaluation given to the results of Examples 1 to 58 so far shown, the lateral projection angle α of the beauty instrument  10  was required to be in a range from 90 degrees to 110 degrees. The lateral projection angle α was judged to be preferable in a range from 93 degrees to 100 degrees and in particular preferable in a range from 95 degrees to 99 degrees. The opening angle β between the balls  17  was judged to be preferable in a range from 50 degrees to 110 degrees, more preferable in a range from 50 degrees to 90 degrees, and in particular preferable in a range from 65 degrees to 80 degrees. The diameter L of the ball  17  was judged to be preferable in a range from 15 mm to 60 mm, more preferable in a range from 32 mm to 55 mm and in particular preferable in a range from 38 mm to 45 mm. The distance D between the outer circumferential surfaces of the balls  17  was judged to be preferable in a range from 8 mm to 25 mm, more preferable in a range from 9 mm to 15 mm and in particular preferable in a range from 10 mm to 13 mm. 
         [0078]    The above embodiment may be modified as follows. 
         [0079]    As shown in  FIGS. 8 and 9 , the shape of the ball  17  may also be formed in a balloon shape such that the curvature of the outer circumferential surface of the ball  17  on the side closer to the handle  11  is greater than the curvature thereof at the tip side of the ball supporting shaft  15 . In the above configuration, the skin can be squeezed at the part of the smaller curvature and the skin can be kept squeezed at the part of the greater curvature. Therefore, the skin  20  can be squeezed more effectively when the balls  17  are moved backward. 
         [0080]    In order to make changeable the lateral projection angle α of the axis y of the ball  17  with respect to the centerline x of the handle  11 , the handle  11  and the bifurcated portions  11   a  may be configured to be pivoted relative to each other. In this case, the angle of the axis y of each ball  17  can be easily changed with respect to the skin  20 , resulting in an improvement in usability of the beauty instrument. 
         [0081]    The ball  17  may be changed into a shape the cross section of which is an oval or an ellipse, whenever necessary. 
         [0082]    A magnet may be buried into the outer circumferential part of the ball  17  to promote blood flow of the skin  20  by the magnetic force thereof. 
         [0083]    A photocatalyst such as titanium oxide may be buried into the outer circumferential part of the ball  17  to suppress adhesion of dirt on the surface of the skin or to oxidize dirt. 
         [0084]    Alumina-based ceramic or zirconium-based ceramic, which emit far infrared rays, may be contained in the ball  17 , thereby irradiating far infrared rays to the skin  20 . 
         [0085]    It is also possible to use a dry cell in place of the solar cell panel  24 . 
         [0086]    It is possible that the upper handle cover  13   a  or the lower handle cover  13   b  is not subjected to electrically conductive plating, but the upper handle cover  13   a  and the lower handle cover  13   b  are directly made of an electrically conductive plastic in which electrically conductive powder such as carbon black or metal is dispersed into a plastic. 
         [0087]    The electrically insulating material that forms the base  12  of the handle  11  and the handle cover  13  may include plastics such as acrylic plastic and polypropylene plastic, in addition to nylon plastic and ABS plastic. 
         [0088]    It is also possible to form the faces  17   a  of the ball  17  in the shape of a polygon or a circle other than a triangle. The faces  17   a  may also be formed into various patterns such as a vertical stripe pattern, a horizontal strip pattern, a swirling stripe pattern, a matt finish, and a pattern-free. 
         [0089]    It is also possible to omit the permanent magnet  22  or the solar cell panel  24 . 
         [0090]    It is also possible to change the shape of the handle  11 . It can be formed in the shape of a cylinder, a circular column, or a rectangular column. In this case, the lateral projection angle α is an angle with respect to the axis of the handle  11 . The handle  11  can be formed in a concave-convex shape and in a gourd shape. 
         [0091]    It is also possible to form the bearing member  19  with an electrically conductive plastic. 
       DESCRIPTION OF THE REFERENCE NUMERALS 
       [0092]      10  . . . beauty instrument,  11  . . . handle,  17  . . . ball,  20  . . . skin, x . . . centerline, y . . . axis, α . . . lateral projection angle, β . . . opening angle between balls, L . . . diameter of ball, D . . . distance between outer circumferential surfaces of balls.