Patent Publication Number: US-10321216-B2

Title: Wearable device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. National Phase of International Patent Application No. PCT/JP2015/084123 filed on Dec. 4, 2015, which claims priority benefit of Japanese Patent Application No. JP 2015-059465 filed in the Japan Patent Office on Mar. 23, 2015. Each of the above-referenced applications is hereby incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The technology disclosed herein relates to a wearable device that is used directly in contact with the skin of a living body. 
     BACKGROUND ART 
     Devices (which will also be referred to as “wearable devices”) that are worn and used by human bodies or other living bodies have been gaining widespread use with smaller and lighter electronic parts. Many of the wearable devices are directly attached to living bodies or directly come into contact with the skin or body parts of the living bodies when used. 
     For example, headphones that have already been used widely are small audio reproduction devices that are attached to the area near the earholes of humans when used, and convert electrical signals output from reproduction devices and receivers into audio signals through speakers positioned near the ears or eardrums. Audio reproduction devices of this type each emit sounds to allow only the listener wearing the audio reproduction device to listen to the sounds, so that the audio reproduction devices are used in a variety of environments. 
     Many of the currently popular headphones are shaped to be plugged into the ears of listeners. For example, inner ear headphones belong to an “earplug type,” and the tips of the sound conduits including earpieces (or ear tips) made from a flexible material are plugged into ear canal entrances of listeners. Earpieces including shade-shaped films made from silicone rubber are in the mainstream (see, for example, Patent Literature 1). Moreover, there appear earpieces each of which includes a foamed material in the space between the shade-shaped outer sheath and the sound wave path (see, for example, Patent Literature 2), and earpieces the whole of which is formed from a foamed material, and which uses the cushioning characteristics to close ear canals. 
     Urethane-based foamed materials such as polyurethane are in the mainstream at the time when the present application is filed. However, urethane-based foamed materials easily hydrolyze. Accordingly, urethane-based foamed materials are insufficient for wearable devices from the perspective of durability. For example, in a case where an earpiece the whole exterior of which is formed from polyurethane is used directly in contact with the skin (such as the inner wall of the ear canal) of a living body, the surface of the earpiece hydrolyzes and deteriorates because of sweat. The comfortability is gradually lost. Further, in a case where an earpiece the whole of which is made from polyurethane is manufactured through in-mold foaming, the outer periphery of the earpiece that directly comes into contact with an earhole (inner wall of the ear canal) becomes hard or sticky because of the coating, resulting in the decreased comfortability. Further, in a case where an earpiece the whole of which is made from polyurethane is processed through slicing or cutting, all the shapes that the earpiece can have is a simple one such as a solid of revolution, resulting in the decreased comfortability. Alternatively, processing an earpiece having a complicated shape through slicing or cutting increases the cost. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: JP 2009-55249A 
     Patent Literature 1: JP 2014-87054A 
     DISCLOSURE OF INVENTION 
     Technical Problem 
     An object of the technology disclosed herein is to provide a wearable device that is used directly in contact with the skin of a living body and excellent in durability and comfortability. 
     Solution to Problem 
     The technology disclosed herein is devised in view of the above-described problem, and a first aspect thereof is a wearable device including: a contact section that has silicone foam disposed over a whole exterior thereof, and comes into contact with a skin of a living body; and a support section of the contact section. 
     According to a second aspect of the technology disclosed herein, the wearable device according to the first aspect is configured as an earpiece for a headphone that is plugged into an ear canal of a human or another living body. The support section is a hollow shaft that is attached to a sound conduit of the headphone, and the contact section is an ear canal attachment section that is attached to an outer side of the shaft and comes into contact with an ear canal inner wall. 
     According to a third aspect of the technology disclosed herein, the shaft of the wearable device according to the second aspect includes a more rigid material than a material of the ear canal attachment section. 
     According to a fourth aspect of the technology disclosed herein, the shaft of the wearable device according to the second aspect includes silicone rubber. 
     According to a fifth aspect of the technology disclosed herein, the earpiece of the wearable device according to the fourth aspect is manufactured by applying insert molding to the shaft and the ear canal attachment section. 
     According to a sixth aspect of the technology disclosed herein, the shaft of the wearable device according to any of the second to fifth aspects includes a deformation section that easily deforms in accordance with an external force applied via the ear canal attachment section. 
     According to a seventh aspect of the technology disclosed herein, the deformation section of the wearable device according to the sixth aspect is formed by making the shaft thinner toward a shaft tip. 
     According to an eighth aspect of the technology disclosed herein, the deformation section of the wearable device according to the sixth aspect is formed from a more elastic material than a material of another portion of the shaft. 
     According to a ninth aspect of the technology disclosed herein, the shaft of the wearable device according to any of the first to eighth aspects further includes a thick section that makes an opening at a tip of the shaft difficult to crush. 
     According to a tenth aspect of the technology disclosed herein, the thick section of the wearable device according to the ninth aspect is provided to the tip of the shaft. 
     According to an eleventh aspect of the technology disclosed herein, the wearable device according to any of the second to tenth aspects further includes: a shade section that includes a thin film and forms a space between the shade section and the shaft. The ear canal attachment section is attached to the shaft via the shade section. 
     Advantageous Effects of Invention 
     According to the technology disclosed herein, it is possible to provide a wearable device a part of which directly comes in contact with the skin of a living body includes silicone foam and which is excellent in durability and comfortability. 
     Note that the advantageous effects described in this specification are merely for the sake of example, and the advantageous effects of the present invention are not limited thereto. Furthermore, in some cases the present invention may also exhibit additional advantageous effects other than the advantageous effects given above. 
     Further objectives, features, and advantages of the technology disclosed in this specification will be clarified by a more detailed description based on the exemplary embodiments discussed hereinafter and the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram illustrating an exterior configuration of a headphone  100  to which a technology disclosed herein is applied. 
         FIG. 2  is a diagram illustrating the exterior configuration of the headphone  100  to which the technology disclosed herein is applied. 
         FIG. 3  is a diagram illustrating the exterior configuration of the headphone  100  to which the technology disclosed herein is applied. 
         FIG. 4  is a diagram illustrating the exterior configuration of the headphone  100  to which the technology disclosed herein is applied. 
         FIG. 5  is a diagram illustrating the exterior configuration of the headphone  100  to which the technology disclosed herein is applied. 
         FIG. 6  is a diagram illustrating the exterior configuration of the headphone  100  to which the technology disclosed herein is applied. 
         FIG. 7  is an exploded perspective view of the headphone  100  illustrated in  FIGS. 1 to 6 . 
         FIG. 8  is a cross-sectional view of the headphone  100  illustrated in  FIGS. 1 to 6 . 
         FIG. 9  is a diagram illustrating the headphone  100  worn in a left ear of a wearer. 
         FIG. 10  is a cross-sectional view of an earpiece  150  according to a first embodiment. 
         FIG. 11  is a diagram illustrating that an ear canal attachment section  156  deforms when a foreign object  1101  is pushed against the earpiece  150  according to the first embodiment. 
         FIG. 12  is a diagram illustrating that a shade-shaped ear canal attachment section  1202  formed from an elastic material deforms when a foreign object  1201  is pushed against the ear canal attachment section  1202 . 
         FIG. 13  is a diagram illustrating that the earpiece  150  deforms when the headphone  100  according to the first embodiment is plugged into an ear canal entrance. 
         FIG. 14  is a diagram illustrating that a shade-shaped earpiece formed from an elastic material deforms when a headphone including the earpiece is plugged into an ear canal entrance. 
         FIG. 15  is a cross-sectional view of the earpiece  150  according to a second embodiment. 
         FIG. 16  is a cross-sectional view of the earpiece  150  according to a third embodiment. 
         FIG. 17  is a cross-sectional view of the earpiece  150  according to a fourth embodiment. 
         FIG. 18  is a cross-sectional view of the earpiece  150  according to a fifth embodiment. 
         FIG. 19  is a cross-sectional view of the earpiece  150  according to a sixth embodiment. 
     
    
    
     MODE(S) FOR CARRYING OUT THE INVENTION 
     Embodiments of the present disclosure will be described below in detail with reference to the drawings. 
       FIGS. 1 to 6  illustrate the exterior configuration of a headphone  100  to which an earpiece  150  to which the technology disclosed herein is applied is attached. The headphone  100  according to the present embodiment, however, belongs to an “earplug type,” and has the earpiece  150  attached to the tip of a sound conduit  140  and plugged into an ear canal entrance of a human (which will be referred to as “wearer”). The earpiece  150  is made from a flexible material. 
       FIGS. 1 to 6  illustrate the configuration of the headphone  100  worn in the left ear of a wearer.  FIG. 1  illustrates the appearance of the headphone  100  worn in the left ear of a wearer.  FIG. 2  is a perspective view obliquely illustrating the back of the headphone  100 .  FIG. 3  is a front view illustrating the headphone  100  worn in the left ear of a wearer from the frontal direction of the wearer.  FIG. 4  is a back view illustrating the headphone  100  worn in the left ear of a wearer from the back direction of the wearer.  FIG. 5  is a frontal view of the headphone  100 .  FIG. 6  is a back view of the headphone  100  (corresponding to a view illustrating a wearer wearing the headphone  100  from the side). 
     As illustrated in  FIGS. 1 to 6 , the headphone  100  includes a housing  110  that is shaped substantially like a disk, a sound conduit  140  that protrudes from the housing  110  and is shaped substantially like a cylinder, and an earpiece  150  that is attached to the tip of the sound conduit  140 . Further, the headphone  100  includes a bushing  160  on the back side, and a cord  170  that is held by the bushing  160 . The bushing  160  protrudes from the housing  110 . The housing  110  is partially covered with a front cap  180  that is bent and shaped substantially like the letter L, and a back cap  185  that is shaped substantially like a half cylinder. 
     The housing  110  is formed from a light and solid material such as magnesium in order to make the case smaller and thinner. A driver unit (described below) including a diaphragm is housed in the housing  110 , and a space surrounding the front of the diaphragm is formed in the housing  110 . The driver unit drives the diaphragm in accordance with sound signals supplied via the cord  170 , thereby generating air vibration in the front space of the diaphragm. Additionally, the top of the housing  110  has an air vent  126  that allows the front space of the diaphragm to communicate with the outside of the housing  110 . 
     The sound conduit  140  is integrated with the housing  110  to protrude toward the frontal side of the earphone  100 , and plugged into an ear canal of a human via the earpiece  150 . The sound conduit  140  conducts the air vibration generated by the driver unit (described below) to the ear canal as the sound waves in the audible range corresponding to the sound signals. 
     The earpiece  150  deforms to follow the shape of the ear canal of the left ear of a human wearing the earpiece  150 , and comes into close contact with the ear canal, thereby having the ear canal hold the housing  110 . Earpieces including a shade-shaped silicone rubber film have gained widespread use. In contrast, soft silicone foam, which is a foamed material, is disposed over the whole exterior of the earpiece  150  according to the present embodiment. Further, the tip portion of the sound conduit  140  in the earpiece  150  is shaped to be easily wound without blocking the sound path, making it possible to keep the comfortable wearability while allowing the earpiece  150  to keep close contact with the ear canal. The earpiece  150  will be described below in detail. 
     The bushing  160  is formed from an elastic material such as elastomer. The bushing  160  fixes, to the housing  110 , the position at which the cord  170  connected to the driver unit (described below) is pulled out. The bushing  160  extends from the back side of the housing  110  in consideration of the interference with the pinna. When the headphone  100  is worn in the left ear of a human, the bushing  160  faces the substantially perpendicular direction and is disposed to be easy for the human to pinch between fingertips. 
     The front cap  180  is formed, for example, from stainless steel or the like. Further, back cap  185  is formed, for example, from plastics or the like. The front cap  180  and the back cap  185  protect the housing  110 , the cord  170 , an air vent described below, and the like. 
     Next, the internal configuration of the headphone  100  to which the earpiece  150  to which the technology disclosed herein is applied to is attached to will be described.  FIG. 7  illustrates the exploded headphone  100 . Further,  FIG. 8  illustrates a cross section of the headphone  100  (cross section vertical to an attachment face P of a diaphragm  198  and including a central axis C 1  of the sound conduit  140 ). 
     As illustrated in  FIGS. 7 and 8 , the housing  110  includes a front housing  120  and a back housing  130 . The front housing  120  and the back housing  130  are each shaped substantially like a bowl, and joined, for example, through ultrasonic welding or the like to form the housing  110 . The housing  110  houses a driver unit  190 . 
     The front housing  120  includes a front section  122  that is shaped substantially like a bowl, the sound conduit  140  that protrudes from a part of the side wall included in the front section  122 , and a bent section  124  that is included in another part of the side wall. When the headphone  100  is worn in the left ear of a wearer, the front section  122  is disposed substantially on the frontal side of the wearer, the sound conduit  140  is disposed to have substantially the same axis as the axis of the ear canal of the wearer, and the bent section  124  is disposed substantially on the side of the wearer. 
     A concave section  123  is formed at the portion corresponding to the bottom of the bowl of the front section  122 . An air vent  128  is formed near the border between the concave section  123  and the bent section  124 . The bent section  124  is a substantially U-shaped plane as viewed from the side of the wearer, and includes a side wall  125  that protrudes from the side wall included in the front section  122 . The bent section  124  has a space therein to house the bushing  160  and the cord  170 . The space is surrounded by the side wall  125 . The air vent  126  and a bushing attachment hole  127  are provided to the portion of the side wall  125  positioned on the border side of the front section  122 . Further, an annular engagement convex section  141  is formed near the tip of the sound conduit  140  for engaging with the inner wall of the earpiece  150 . 
     The back housing  130  includes a back section  132  that is shaped substantially like a bowl, and a curved section  134  that has the shape of a plane curved toward a part of the portion corresponding to the bottom of the bowl. A side wall  135  stands on the curved section  134 . The curved section  134  has a space therein to house the cord  170 . The space is surrounded by the side wall  135 . When the headphone  100  is worn in the left ear of a wearer, the back section  132  is disposed substantially on the back side of the wearer, and the curved section  134  is disposed in the upper space of the antitragus without interfering with the pinna of the wearer. Further, the back section  132  positioned under the curved section  134  is disposed in an intertragic notch d (see  FIG. 1 ) along with the front section  122  positioned under the bent section  124 . 
     The back section  132  has the shape substantially corresponding to the shape of the front section  122 . The space formed by the side wall  135  of the curved section  134  has substantially the same width as the width of the space formed by the side wall  125  of the bent section  124 . Both spaces are connected to form a single space. 
     The earpiece  150  includes a shaft  152  that is attached to the sound conduit  140 , and an ear canal attachment section  156  that is attached to the outer side of the shaft  152  and comes into contact with an ear canal inner wall (i.e., the skin of a human) of a wearer. An annular engagement concave section  153  is provided to the inner wall of the shaft  152  to engage with the engagement convex section  141  (described above) of the sound conduit  140 . The earpiece  150  includes the ear canal attachment section  156  over the whole exterior of which soft silicone foam, which is a foamed material, is disposed. Further, the tip portion of the sound conduit  140  in the earpiece  150  is shaped to be easily wound without blocking the sound path, thereby making it possible to maintain comfortable wearability while keeping the earpiece  150  in close contact with the ear canal. An annular engagement convex section  154  is provided to the outer wall of the shaft  152  for engaging with the inner wall of the ear canal attachment section  156 . Further, the ear canal attachment section  156  is hollow and allows the shaft  152  to be plugged through the ear canal attachment section  156 . An annular engagement concave section  157  is provided to the inner wall thereof for engaging with the engagement convex section  154  of the shaft  152 . The earpiece  150  is worn in an ear canal of a wearer to have substantially the same axis as the axis of the ear canal. The earpiece  150  will be described below in detail. 
     The bushing  160  includes an attachment section  162  and a cord fixation section  164  that extends from the attachment section  162 . The attachment section  162  is attached to the bushing attachment hole  127  provided to the bent section  124  of the front housing  120 , and can slightly pivot. The cord fixation section  164  fixes, to the housing  110 , the position at which the cord  170  connected to the driver unit  190  is pulled out. 
     The front cap  180  is formed to cover the space formed by the concave section  123  of the front housing  120  and the side wall  125  of the bent section  124 . The back cap  185  is connected to the bent section  124  of the front housing  120  to cover the space formed by the side wall  135  of the curved section  134  of the back housing  130 . There is an air vent  186  obtained by drilling an end of the back cap  185 . Further, the front cap  180  and the back cap  185  are formed to respectively cover the air vent  128  and an air vent  136  on the front housing  120  and the back housing  130 . 
     As illustrated in  FIG. 3 , the cord  170  is disposed on the back side of the front housing  120  via the attachment section  162  of the bushing  160  disposed in the space formed by the side wall  125  of the bent section  124  of the front housing  120 . The cord  170  is pulled into the space formed by the side wall  135  of the curved section  134  of the back housing  130  (cord  172 ), and is connected to a cord  176  on the driver unit  190  side via a knot  174 . The front cap  180  and the back cap  185  are then attached to the front housing  120  and the back housing  130 , respectively, thereby protecting the bushing  160  disposed on the back side of the housing  110  and the cord  170 . 
     The driver unit  190  includes a frame  192 , a magnet  194 , a pole piece  196 , and the diaphragm  198 . The diaphragm  198  including a voice coil  199  is disposed in the magnetic circuit including the magnet  194  in the driver unit  190 . The diaphragm  198  is then driven in accordance with sound signals supplied to the voice coil  199  via the cord  170 . The driver unit  190  is grasped between the front housing  120  and the back housing  130  via the frame  192 , and integrated with the housing  110 , thereby suppressing unnecessary vibration to improve the quality of sounds in the low range. Further, spaces (front cavity and back cavity) are formed at the front and back of the driver unit  190  with the driver unit  190  housed in the housing  110 . 
       FIG. 9  is a cross-sectional view of the head of a wearer wearing the headphone  100  in the left ear. As illustrated in  FIG. 9 , the headphone  100  has the housing  110  disposed in a cavity d of the concha (see  FIG. 1 ). The headphone  100  is attached to an ear canal a via the earpiece  150  attached to the sound conduit  140  with the sound conduit  140  plugged into the ear canal a through the area between a tragus b and an antitragus c. Here, the earpiece  150  can come into closer contact with the ear canal a by deforming to follow the shape of the ear canal a. 
     The earpiece  150  of the headphone  100  according to the present embodiment includes the shaft  152  that is attached to the sound conduit  140 , and the ear canal attachment section  156  that is attached to the outer side of the shaft  152  and comes into contact with an ear canal inner wall (i.e., the skin of a human) of a wearer. 
       FIG. 10  illustrates the cross-sectional configuration of the earpiece  150  according to the first embodiment. The earpiece  150  includes the shaft  152  that is attached to the sound conduit  140 , and the ear canal attachment section  156  that is attached to the outer side of the shaft  152  and comes into contact with an ear canal inner wall of the wearer. 
     Soft silicone foam, which is a foamed material, is disposed over the whole exterior of the ear canal attachment section  156  to maintain the comfortable wearability while keeping close contact with the ear canal. Further, the shaft  152  is formed from silicone rubber or the like. The shaft  152  is harder than the ear canal attachment section  156  made from silicone foam. Even if force is applied, the shaft  152  can retain the original shape to some extent. 
     Inserting the shaft  152  into the hollow ear canal attachment section  156  (i.e., attaching the ear canal attachment section  156  made from silicone foam to the tip of the sound conduit  140  via the shaft  152 ) thus makes it possible to have the tip portion of the sound conduit  140  shaped to be easily wound without blocking the sound path (if the tip portion of the sound conduit  140  should be blocked, there would be the problem that the quality of sounds more easily deteriorates), while keeping the earpiece  150  in close contact with the ear canal and allowing the earpiece  150  to be comfortably worn. 
     Additionally, urethane-based foamed materials such as polyurethane are in the mainstream at the time when the present application is filed. However, for example, earpieces the whole exterior of which is formed from polyurethane are easily hydrolyzed by sweat or the like, and are insufficient from the perspective of durability or comfortability (described above). In contrast, the technology disclosed herein can configure the earpiece  150  that does not deteriorate through hydrolysis, but is excellent in durability and comfortability, by disposing soft silicone foam over the whole exterior of the ear canal attachment section  156 . Further, attaching the ear canal attachment section  156  made from silicone foam to the tip of the sound conduit  140  via the shaft  152  makes it possible to have the tip portion of the sound conduit  140  shaped to be easily wound, which prevents the sound path from being blocked, while keeping the earpiece  150  in close contact with the ear canal and allowing the earpiece  150  to be comfortably worn. 
     Further, there is the problem that difficult processing is necessary to manufacture urethane-based earpieces (described above). In contrast, the ear canal attachment section  156  the whole exterior of which is made from silicone foam can be integrated with the shaft  152  made from silicone rubber, for example, through insert molding, which does not require any adhesion, in the earpiece  150  according to the technology disclosed herein. 
     A method for integrating the ear canal attachment section  156  made from silicone foam with the shaft  152  made from silicone rubber through insert molding requires easier processing or costs less than a method for manufacturing and then assembling the ear canal attachment section  156  made from silicone foam and the shaft  152  made from silicone rubber as different parts, and joining the ear canal attachment section  156  made from silicone foam and the shaft  152  made from silicone rubber with an adhesive or the like. Accordingly, mass production is possible. Further, insert molding scarcely makes a gap between the ear canal attachment section  156  and the shaft  152 . Further, silicone foam has excellent compatibility with silicone rubber. The ear canal attachment section  156  does not part from the shaft  152  after used. Accordingly, it is possible to eliminate a cause of sound leaking. 
     The structure of the earpiece  150  will be described in more detail. The annular engagement concave section  153  is provided to the inner wall of the shaft  152  formed from silicone rubber to engage with the engagement convex section  141  (not illustrated in  FIG. 10 ) of the sound conduit  140 . Further, the annular engagement convex section  154  is provided to the outer wall of the shaft  152  for engaging with the inner wall of the ear canal attachment section  156 . 
     Meanwhile, the ear canal attachment section  156  is hollow and allows the shaft  152  to be inserted thereinto. The annular engagement concave section  157  is provided to the inner wall thereof. As illustrated in the figure, the engagement concave section  157  engages with the engagement convex section  154  on the shaft  152  side. As described above, soft silicone foam, which is a foamed material, is disposed over the entire exterior of the ear canal attachment section  156 . The outer surface of the ear canal attachment section  156  comes into contact with the skin (inner wall of the ear canal) of a wearer, but there is no possibility of hydrolysis. The ear canal attachment section  156  is excellent in durability and comfortability. 
       FIG. 11  illustrates that the ear canal attachment section  156  deforms when a foreign object  1101  having a quadrangular cross section is pushed against the earpiece  150  (outer surface of the ear canal attachment section  156 ) according to the present embodiment. The foreign object  1101  is considered as the inner wall of an ear canal, which abuts the headphone  100  when the headphone  100  is worn in the ear of the wearer (i.e., when the earpiece  150  is plugged into the ear canal). If silicone foam disposed over the entire exterior of the ear canal attachment section  156  is softened to the appropriate extent, the ear canal attachment section  156  deforms along the contour of the foreign object  1101  as illustrated in  FIG. 11 . Accordingly, it is possible to keep very close contact with the foreign object  1101 , achieving excellent sound insulation (quality of sounds) and comfortability. 
     Further,  FIG. 12  illustrates as a comparison that a shade-shaped ear canal attachment section (see, for example, Patent Literature  1 )  1202  formed from an elastic material such as silicone rubber deforms when a foreign object  1201  having a quadrangular cross section is pushed against the ear canal attachment section  1202 . The shade-shaped ear canal attachment section  1202  has gaps denoted with the reference numbers  1203  and  1204  when the tip of the foreign object  1201  is pushed against the shade-shaped ear canal attachment section  1202  and the shade deforms. The gaps  1203  and  1204  cause loss of close contact or comfortability, and cause the headphone to leak sounds or easily detach from the ear canal. The shade-shaped earpiece  1202  cannot thus achieve the close contact, sound insulation, or comfortability as achieved by the earpiece  150  (see  FIG. 11 ) according to the present embodiment. 
       FIG. 10  will be referred to again. The shaft  152  includes a deformation section  155  that is thinner and more easily deforms toward the tip. The deformation section  155  is easy to wind, for example, when the earpiece  150  is plugged into an ear canal of a wearer. Further, the engagement convex section  154  is provided to the tip of the shaft  152 , for example, along the opening. The engagement convex section  154  also serves as a thick section that is thick, and makes the opening at the tip of the shaft  152  more difficult to crush and prevents the sound path from being blocked even when the shaft  152  is greatly bent near the deformation section  155 . 
       FIG. 13  illustrates that the earpiece  150  deforms when the headphone  100  according to the present embodiment is plugged into an ear canal entrance. As already described with reference to  FIG. 11 , the ear canal attachment section  156  made from silicone foam, which is appropriately soft, can keep close contact and achieve excellent sound insulation (quality of sounds) by deforming along the shape of an ear canal of a wearer. Further, the shaft  152  inserted into the hollow ear canal attachment section  156  is greatly bent and escapes chiefly near the deformation section  155  along with the deformation of the ear canal attachment section  156 , thereby making it easier for the earpiece  150  to move further inside the ear canal to improve the wearability and sound insulation. Further, even if the shaft  152  is wound at the deformation section  155 , the shaft  152  increases in thickness at the engagement convex section  154 . Accordingly, the opening at the tip of the shaft  152  is difficult to crush, and the sound path is not blocked. It is understood from  FIG. 13  that the earpiece  150  according to the present embodiment has the tip portion of the sound conduit  140  shaped to be easily wound, which prevents the sound path from being blocked, while maintaining close contact with the ear canal and comfortable wearability. Additionally, the ear canal attachment section  156  unevenly deforms on the left part of  FIG. 13  that abuts the inside corner of the first curve and on the right part of  FIG. 13  that abuts the outside corner of the first curve in the example illustrated in  FIG. 13  in which the earpiece  150  is worn in an ear canal. 
     Further,  FIG. 14  illustrates as a comparison that a shade-shaped earpiece (see, for example, Patent Literature 1)  1401  formed from an elastic material such as silicone rubber deforms when a headphone including the earpiece  1401  is plugged into an ear canal entrance. The shade-shaped earpiece  1401  abuts the inner wall of the ear canal and deforms. However, the silicone rubber, which is a material thereof, is not as flexible as silicone foam, which is a foamed material. As already described with reference to  FIG. 12 , it is not therefore possible to achieve the close contact, sound insulation, or comfortability as achieved in the present embodiment because gaps are made when the shade is warped. 
       FIG. 15  illustrates the cross-sectional configuration of the earpiece  150  according to the second embodiment. The earpiece  150  includes the shaft  152  that is attached to the sound conduit  140 , and the ear canal attachment section  156  that is attached to the outer side of the shaft  152  and comes into contact with an ear canal inner wall of the wearer. 
     The second embodiment is different from the first embodiment in that the annular engagement convex sections  154  are provided to the outer wall of the shaft  152  for engaging with the inner wall of the ear canal attachment section  156 , and the annular engagement convex sections  154  are pleated. Further, the corresponding parts of the inner wall of the ear canal attachment section  156  are provided with annular engagement concave sections. Similarly to the earpiece  150  according to the first embodiment, the ear canal attachment section  156  made from silicone foam, which is appropriately soft, can keep close contact and achieve excellent sound insulation (quality of sounds) by deforming along the shape of an ear canal of a wearer. Further, the portion near the tip of the shaft  152  increases in thickness at the engagement convex sections  154 . Accordingly, the shaft  152  has the tip portion of sound conduit  140  shaped to be easily wound, which prevents the sound path from being blocked. 
     Further,  FIG. 16  illustrates the cross-sectional configuration of the earpiece  150  according to the third embodiment. The earpiece  150  includes the shaft  152  that is attached to the sound conduit  140 , and the ear canal attachment section  156  that is attached to the outer side of the shaft  152  and comes into contact with an ear canal inner wall of a wearer. 
     The shaft  152  includes a deformation section  155  that is thinner and more easily deforms toward the tip. The deformation section  155  is easy to wind, for example, when the earpiece  150  is plugged into an ear canal of a wearer. The third embodiment is different from the first embodiment in that the shaft  152  includes two silicone rubber materials (or three or more types of material) having different mechanical characteristics such as elasticity for the portion from the deformation section  155  to the base, and the deformation section  155  and the portion from the deformation section  155  to the tip.  FIG. 16  illustrates the difference of the shaft  152  in materials with the light and dark shading. The portion (shaded in light color) near the tip of the shaft  152  corresponds to the deformation section  155 . It is possible to adjust the elasticity for the deformation section  155  to more easily deform than the base side (shaded in dark color) of the shaft  152 , and have the tip portion of the sound conduit  140  shaped to be more easily wound, which prevents the sound path from being blocked. It is possible to easily manufacture the shaft  152  made from two different silicone rubber materials as illustrated in  FIG. 16  using the molding technology such as insert molding or two-color molding. 
     Further, similarly to the first embodiment, the ear canal attachment section  156  made from silicone foam, which is appropriately soft, in the earpiece  150  according to the third embodiment can keep close contact and achieve excellent sound insulation (quality of sounds) by deforming along the shape of an ear canal of a wearer. 
     Further,  FIG. 17  illustrates the cross-sectional configuration of the earpiece  150  according to the fourth embodiment. The earpiece  150  includes the shaft  152  that is attached to the sound conduit  140 , and the ear canal attachment section  156  that is attached to the outer side of the shaft  152  and comes into contact with an ear canal inner wall of the wearer. 
     The fourth embodiment is different from the first to third embodiments in that the deformation section  155  formed at the tip of the shaft  152  is not cylindrical as in the first to third embodiments, but is configured to support the thick section (engagement convex section)  154  at the tip using columnar projections formed in the axial direction of the shaft  152 . Similarly to the earpiece  150  according to the first embodiment, the ear canal attachment section  156  made from silicone foam, which is appropriately soft, can keep close contact and achieve excellent sound insulation (quality of sounds) by deforming along the shape of an ear canal of a wearer. Further, the portion near the tip of the shaft  152  increases in thickness at the engagement convex sections  154 .Accordingly, the shaft  152  has the tip portion of sound conduit  140  shaped to be easily wound, which prevents the sound path from being blocked. 
     Further,  FIG. 18  illustrates the cross-sectional configuration of the earpiece  150  according to a fifth embodiment. The earpiece  150  includes the shaft  152  that is attached to the sound conduit  140 , and the ear canal attachment section  156  that is attached to the outer side of the shaft  152  and comes into contact with an ear canal inner wall of a wearer. 
     The deformation section  155  formed at the tip of the shaft  152  is more gently sloped than that of the first embodiment (see  FIG. 10 ). Similarly to the earpiece  150  according to the first embodiment, the ear canal attachment section  156  made from silicone foam, which is appropriately soft, can keep close contact and achieve excellent sound insulation (quality of sounds) by deforming along the shape of an ear canal of a wearer. Further, the portion near the tip of the shaft  152  increases in thickness at the engagement convex sections  154 .Accordingly, the shaft  152  has the tip portion of sound conduit  140  shaped to be easily wound, which prevents the sound path from being blocked. It should be noted that the shaft  152  or the deformation section  155  near the tip thereof is not limited to a specific shape in order that the earpiece  150  attains a desired effect. 
       FIG. 19  illustrates the cross-sectional configuration of the earpiece  150  according to a sixth embodiment. The earpiece  150  includes the shaft  152  that is attached to the sound conduit  140 , and the ear canal attachment section  156  that is attached to the outer side of the shaft  152  and comes into contact with an ear canal inner wall of a wearer. Further, different from the earpiece  150  according to the first to fifth embodiments, the earpiece  150  illustrated in  FIG. 19  has the ear canal attachment section  156  attached to the outer side of the shaft  152  via a shade section  158  including a thin film, and a space is formed between this shade section  158  and the shaft  152 . Soft silicone foam, which is a foamed material, is disposed over the entire exterior of the ear canal attachment section  156 . 
     Additionally, the ear canal attachment section  156  unevenly deforms on the left part of  FIG. 13  that abuts the inside corner of the first curve and on the right part of  FIG. 13  that abuts the outside corner of the first curve in the example illustrated in  FIG. 13  in which the earpiece  150  is worn in an ear canal (described above). The left and right of the ear canal attachment section  156  deform to different degrees when worn in an ear canal, which can be similarly applied to the second to fifth embodiments respectively illustrated in  FIGS. 15 to 18 . Greater deformation means that the resilience generated in silicone foam is greater in the left side of  FIG. 13 . Such partial pressure affects the stability of the main body of the headphone  100 , consequently arousing concern that the wearability of the earpiece  150  in an ear canal deteriorates. 
     The earpiece  150  is then configured in the sixth embodiment illustrated in  FIG. 19  in a manner that the ear canal attachment section  156  is attached via the shade section  158  that includes a thin film and forms a space between the shade section  158  and the shaft  152  as described above. Even if the shape of the ear canal attachment section  156  in the radial direction greatly deforms in part as illustrated in  FIG. 13 , it is thus possible to follow the deformation using the space formed by the shade section  158  to prevent the wearability from deteriorating. 
     The following summarizes the advantages of an earpiece including an ear canal attachment section over the entire exterior of which soft silicone foam, which is a foamed material, is disposed.
     (1) There is no possibility that a silicone foam material is hydrolyzed by moisture such as sweat or earwax, so that excellent durability is secured.   (2) It is possible to wash an earpiece using water or a detergent and keep the earpiece clean.   (3) Soft silicone foam causes less pressure on an ear of a wearer when a headphone is worn, so that the wearer feels comfortable.   (4) Soft silicone foam does not breathe, so that it is easy to close an ear canal when a headphone is worn, which achieves excellent noise isolation.   (5) A deformation section is formed near the tip of a shaft that supports an ear canal attachment section of silicone foam, so that the tip of the shaft is wound and escapes to move further inside an ear canal when an earpiece is plugged into the ear canal, which improves the wearability and noise isolation.   (6) Even if a portion near the tip of a shaft is wound, the tip increases in thickness and has a shape difficult to crush, which scarcely blocks a sound path or loses the quality of sounds.   

     INDUSTRIAL APPLICABILITY 
     The foregoing thus describes the technology disclosed in this specification in detail and with reference to specific embodiments. However, it is obvious that persons skilled in the art may make modifications and substitutions to these embodiments without departing from the spirit of the technology disclosed in this specification. 
     The technology disclosed herein is not limited to earpieces, but can be applied to various types of wearable device that is used directly in contact with the skin of a living body. For example, if the technology disclosed herein is applied to the ear pads of headphones, headbands (or headband-type information terminals), the temples of glasses (or glasses-type information terminals), the packing of swimming goggles, the inner sides of the wristbands of watches (or watch-type information terminals), the insoles of shoes (or shoe-type information terminal) or the like, the inner sides of helmets, pillows, cushions, or the like, it is possible to follow the three-dimensional shapes directly in contact with the skins or body parts of living bodies such as humans. Further, the technology disclosed herein can also be applied to various current products that use another foamed material such as urethane. 
     Essentially, the technology disclosed in this specification has been described by way of example, and the stated content of this specification should not be interpreted as being limiting. The spirit of the technology disclosed in this specification should be determined in consideration of the claims. 
     Additionally, the present technology may also be configured as below. 
     (1) 
     A wearable device including: 
     a contact section that has silicone foam disposed over a whole exterior thereof, and comes into contact with a skin of a living body; and 
     a support section of the contact section. 
     (2) 
     The wearable device according to (1), in which 
     the wearable device is configured as an earpiece for a headphone that is plugged into an ear canal of a human or another living body, 
     the support section is a hollow shaft that is attached to a sound conduit of the headphone, and 
     the contact section is an ear canal attachment section that is attached to an outer side of the shaft and comes into contact with an ear canal inner wall. 
     (3) 
     The wearable device according to (2), in which 
     the shaft is made from a more rigid material than a material of the ear canal attachment section. 
     (4) 
     The wearable device according to (2), in which 
     the shaft is made from silicone rubber. 
     (5) 
     The wearable device according to (4), in which 
     the earpiece is manufactured by applying insert molding to the shaft and the ear canal attachment section. 
     (6) 
     The wearable device according to any of (2) to (5), in which 
     the shaft includes a deformation section that easily deforms in accordance with an external force applied via the ear canal attachment section. 
     (7) 
     The wearable device according to (6), in which 
     the deformation section is formed by making the shaft thinner toward a shaft tip. 
     (8) 
     The wearable device according to (6), in which 
     the deformation section is formed from a more elastic material than a material of another portion of the shaft. 
     (9) 
     The wearable device according to any of (1) to (8), in which 
     the shaft further includes a thick section that makes an opening at a tip of the shaft difficult to crush. 
     (10) 
     The wearable device according to (9), in which 
     the thick section is provided to the tip of the shaft. 
     (11) 
     The wearable device according to any of (2) to (10), further including: 
     a shade section that includes a thin film and forms a space between the shade section and the shaft, in which 
     the ear canal attachment section is attached to the shaft via the shade section. 
     REFERENCE SIGNS LIST 
     
         
           100  headphone 
           110  housing 
           120  front housing 
           122  front section 
           123  concave section 
           124  bent section 
           125  side wall 
           126  air vent 
           127  bushing attachment hole 
           128  air vent 
           130  back housing 
           132  back section 
           134  curved section 
           135  side wall 
           136  air vent 
           140  sound conduit 
           141  engagement convex section 
           150  earpiece 
           152  shaft 
           153  engagement concave section 
           154  engagement convex section 
           155  deformation section 
           156  ear canal attachment section 
           157  engagement concave section 
           158  shade section 
           160  bushing 
           162  attachment section 
           164  cord fixation section 
           170 ,  172 ,  176  cord 
           174  knot 
           180  front cap 
           185  back cap 
           186  air vent 
           190  driver unit 
           192  frame 
           194  magnet 
           196  pole piece 
           198  diaphragm 
           199  voice coil