Patent Publication Number: US-10771885-B2

Title: Headphone device

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority under 35 U.S.C. § 119 from Japanese Patent Application No. 2018-134737 filed on Jul. 18, 2018, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     The present disclosure relates to a headphone device enabling a lateral pressure adjustment. 
     Japanese Patent Application Publication No. 2017-098869 (Patent Literature 1) discloses a headphone device enabling a lateral pressure to be adjusted when worn on the head. 
     The headphone device disclosed in Patent Literature 1 includes a plate spring to be put across the head of a user and corresponding to a typical head band having both ends to be located around the right and left ears, and further includes a lateral-pressure adjustable spring, an adjuster, and spacers arranged between the lateral-pressure adjustable spring and the adjuster, so as to adjust a lateral pressure together with the plate spring. 
     SUMMARY 
     The headphone device disclosed in Patent Literature 1 inevitably increases the number of components, which should be reduced, necessary for adjusting a lateral pressure. 
     The headphone device disclosed in Patent Literature 1 has the further disadvantage of hindering the user from visually recognizing a level of a lateral pressure to be adjusted. The headphone device impedes an easy and quick adjustment to a lateral pressure fit for each individual user when several users use the common headphone device, for example. Thus, a need exists for facilitating the adjustment to a lateral pressure to be fit for each user. 
     An aspect of one or more embodiments provides a headphone device including: a head pad having a curved shape with a first radius of curvature; a band extending from an edge of the head pad into a curved shape with a second radius of curvature different from the first radius of curvature, and supporting a housing, via a hanger, housing a speaker unit; and a sleeve having a curved shape with the first radius of curvature and slidable along the head pad to cover the band so as to change the radius of curvature at a part of the band covered with the sleeve to approximate to the first radius of curvature. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a rear view showing a headphone device in a first state according to one or more embodiments. 
         FIG. 2  is a front view showing a band included in the headphone device according to one or more embodiments. 
         FIG. 3  is a rear view showing the headphone device in a second state according to one or more embodiments. 
         FIG. 4  is a rear view showing the headphone device in a third state according to one or more embodiments. 
         FIG. 5  is a vertical cross-sectional view showing a head pad included in the headphone device according to one or more embodiments. 
         FIG. 6  is a cross-sectional view taken along line S 6 -S 6  in  FIG. 5 . 
         FIG. 7  is a partial perspective view showing the band of the headphone device in the first state according to one or more embodiments. 
         FIG. 8  is a partial perspective view showing the band of the headphone device in the second state according to one or more embodiments. 
         FIG. 9  is a partial front view showing a headphone device of a second modified example in a first state according to one or more embodiments. 
         FIG. 10  is a partial front view showing the headphone device of the modified example in a second state according to one or more embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     A headphone device  51  according to one or more embodiments is described below with reference to  FIG. 1  to  FIG. 4 . 
     As shown in  FIG. 1 , the headphone device  51  includes a head band  1 , a hanger  21  and a housing  31  for the left ear attached to the left end of the head band  1 , and a hanger  21  and a housing  31  for the right ear attached to the right end of the head band  1 . 
     The head band  1  includes a head pad  11  housing extendable and retractable sleeves  13 . The sleeves  13  are slidably moved by fingers of a user along a band  12  extending from the head pad  11  so as to be freely drawn out of the head pad  11 . 
       FIG. 1  illustrates the headphone device  51  in a first state in which the sleeves  13  are slid to be housed in the head pad  11  to the maximum. The upper, lower, left, and right directions are indicated by the arrows shown in  FIG. 1 . The front side on the paper of each of  FIG. 1  and  FIG. 2  is defined as a rear side. 
     The headphone device  51  yields a lateral pressure that varies depending on the drawn amount of the sleeves  13 . The lateral pressure is a pressure applied around the temples of the user of the headphone device  51  via ear pads  32 . The user of the headphone device  51  can adjust a level of the lateral pressure by regulating the drawn amount of the sleeves  13 . 
     Each of the hangers  21  includes a pivot support  211  at its bottom to pivotally support the housing  31 . The housing  31  houses a speaker unit SP to emit sounds toward the opposite housing  31  in the state shown in  FIG. 1 . The ear pad  32 , in contact with each ear when the headphone device  51  is worn on the head, is attached on the sound-emitting side of the housing  31 . 
     The hangers  21  having a known structure used in a conventional headphone device are each vertically adjustable with respect to the band  12 .  FIG. 1 ,  FIG. 3 , and  FIG. 4  each show a state in which the hangers  21  are located at the uppermost position with respect to the band  12 . 
     The head band  1  includes the head pad  11 , the band  12 , and the sleeves  13 . The head pad  11  is placed on the top of the head, for example, when the headphone device  51  is worn on the head. The head pad  11  is an arc-like sheath-shaped housing having an approximate radius R 1  in the front view. The head pad  11  includes a plurality of resin-based members combined together, for example. 
       FIG. 2  is a front view of the band  12 . The band  12  is a flat curved member made of metal or resin. The band  12  has flexibility in the increasing/decreasing direction of the radius of curvature. 
     The band  12  includes an arc-like middle portion  124  having a radius R 1  in the front view, a pair of arc-like extending portions  125  connected to both ends of the middle portion  124  and having a radius R 2  in the front view, and a pair of plate-like end portions  126  extending from the tips of the extending portions  125 . The radius R 1  is presumed to be a value approximate to an average radius of curvature of the head of an ordinary person. 
     The middle portion  124  have the same radius R 1  as the head pad  11 , and is inserted and fixed to the inside of the head pad  11 . The extending portions  125  extend out of the head pad  11  on both sides in the longitudinal direction to have an arc shape with the radius R 2  different from the radius R 1 . The end portions  126  having a plate-like shape are connected to be housed in the hangers  21 . The band  12  has a smaller flexural rigidity than the sleeves  13 . The following is a case in which the radius R 2  is smaller than the radius R 1 . 
     Next, the structure of the head pad  11  and the movement of the sleeves  13  are illustrated in detail below mainly with reference to  FIG. 5  and  FIG. 6 .  FIG. 5  is a vertical cross-sectional view of the head pad  11  along the middle portion in the front-rear direction, and  FIG. 6  is a cross-sectional view taken along line S 6 -S 6  in  FIG. 5 . 
     The sleeves  13  are each an arc-like sheath-shaped housing having a radius R 1  which is an average radius in the front view, as in the case of the head pad  11  and the middle portion  124  of the band  12 , and is made of resin or metal. As described above, the sleeves  13  have a greater flexural rigidity than the band  12 . 
     At least part of the sleeves  13  is extendably and retractably housed in the sheath-shaped head pad  11 . The sleeves  13  are slidably moved along the band  12  in the longitudinal direction against an elastic repulsive force applied from the band  12  while correcting the curvature of the band  12  to conform to the curvature of the sleeves  13 . The flexural rigidity of each of the band  12  and the sleeves  13  and the elastic repulsive force of the band  12  are regulated so that the sleeves  13  can be slid by the fingers of the user while correcting the curvature of the band  12 . 
     The head band  1  having such a configuration can be set in the following first to third states depending on the position of the sleeves  13 : The first state is a state in which the sleeves  13  are housed in the head pad  11  to the maximum ( FIG. 1 ). The second state is a state in which the sleeves  13  are drawn out of the head pad  11  to the maximum along the band  12  ( FIG. 3 ). The third state is a state between the first state and the second state in which the sleeves  13  are drawn out not to the maximum but by a freely-selected amount from the first state ( FIG. 4 ). 
     As shown in  FIG. 5 , the head pad  11  includes a concentric arc-shaped pad base portion  111  having a radius R 1  at a radial position at which the middle portion  124  of the band  12  penetrates in the front view. The pad base portion  111  is a sheath-shaped housing having a symmetric rectangular shape in lateral cross section. 
     The pad base portion  111  includes a fixed wall portion  113  in the middle in the right-left direction to serve as a partition wall, and a pair of housing portions  112  open at the left and right ends to define the right and left internal spaces partitioned by the fixed wall portion  113 . The paired housing portions  112  have a symmetric shape. The housing portion  112  on the left side is mainly described below. 
     As shown in  FIG. 6 , the housing portion  112  has a rectangular shape in lateral cross section. As shown in  FIG. 5 , an upper inner wall  112   b  of the housing portion  112  is provided with a stopper  112   a  projecting downward and located closer to the left end. A lower inner wall  112   c  of the housing portion  112  has an engagement arm portion  114  projecting upward at a position corresponding to the stopper  112   a.    
     The engagement arm portion  114  includes an arm piece  114   a  flexible in the vertical direction, and a semicolumnar engagement projection  114   b  elongated in the front-rear direction and protruding upward at the tip of the arm piece  114   a.    
     The fixed wall portion  113  has a penetration hole  113   a  through which the right and left housing portions  112  communicate with each other. The band  12  is inserted into the penetration hole  113   a  and fixed to the penetration hole  113   a  in the middle with an adhesive, for example, so as to be integrated with the head pad  11 . 
     The sleeves  13  are described in more detail below. The two sleeves  13  included in the head band  1  are symmetrically housed in the right and left housing portions  112 . The sleeve  13  housed in the housing portion  112  on the left side is mainly described below. 
     The sleeve  13  is a sheath-shaped member having an arc shape in the front view and having a rectangular shape in lateral cross section. The sleeve  13  has an arc-shaped penetration hole  138  open at both ends and having a radius R 1 . The band  12  is slidably inserted into the penetration hole  138 . 
     The sleeve  13  includes a base  132  and a sleeve head  131 . The base  132  can be entirely housed in the housing portion  112 . The sleeve head  131  projects outward on the circumference at the end on the opposite side of the base  132  (on the left side), and is in contact with an end surface  115  of the pad base portion  111 . 
     The sleeve  13  has an outer groove  135 . The outer groove  135  on the outer diameter side of the head band  1  is hollowed out toward the inner diameter of the head band  1  in the middle in the front-rear direction. The outer groove  135  extends from the bottom of the sleeve head  131  to a part adjacent to the right end of the base  132 , and has a contact portion  134  at the right end serving as a wall. 
     The contact portion  134  comes into contact with the stopper  112   a  at the predetermined maximum extending position so that a further slide is regulated when the sleeve  13  is slid to be drawn out of the head pad  11 . 
     As shown in  FIG. 6  or  FIG. 8 , the bottom of the outer groove  135  is provided with a plurality of marks  137   a  slightly recessed at regular intervals so as to collectively serve as a sleeve length indicating portion  137 . As shown in  FIG. 8 , the sleeve length indicating portion  137  is a group of the marks  137   a  formed into recesses aligned at regular intervals in the longitudinal direction of the sleeve  13 , and serves as an adjusted-amount recognition part TH so as to allow the user to visually recognize the adjusted amount of the hanger  21 . 
     The sleeve  13  has an inner groove  136 . The inner groove  136  on the inner diameter side of the head band  1  is hollowed out toward the outer diameter of the head band  1  in the middle in the front-rear direction. The inner groove  136  continuously extends to the end of the base  132 , namely, extends from the bottom of the sleeve head  131  to the right end of the base  132 . 
     The bottom of the inner groove  136  is provided with a plurality of engagement recesses  133  hollowed into a semicircle in cross section at regular intervals in the right-left direction and elongated in the front-rear direction. The engagement recesses  133  are collectively referred to as an engagement recess group  133 G. Each of the engagement recesses  133  can engage with the engagement projection  114   b  when the sleeve  13  is inserted to be slid in the housing portion  112  of the head pad  11 . 
       FIG. 7  and  FIG. 8  are partial perspective views showing the band  12  and the peripheral portions in the first state and the second state of the head band  1 . 
     As shown in  FIG. 7 , the outer surface  122  of the band  12  on the outer side is provided with hanger position indicators  121 . The hanger position indicators  121  are marks for positioning the hanger  21  in the vertical direction, which are a group of slightly recessed marks  121   a  and  121   b . The hanger position indicators  121  collectively serve as an adjusted-amount recognition part TH so as to allow the user to visually recognize the adjusted position of the hanger  21 . 
     The marks illustrated in  FIG. 7  include linear marks  121   a  and numerical marks  121   b , for example. 
     The user, when moving each hanger  21  upward in the direction indicated by the arrow DR 3  to adjust the vertical position as shown in  FIG. 7 , can easily recognize the position of the moved hanger  21  supporting the housing  31  due to the marks not hidden but still remaining visible on the hanger  21 . 
     As shown in  FIG. 7 , the housing  31  pivots on the pivot support  211  at a predetermined angle in the vertical direction and the front-rear direction indicated by the arrows DR 4 . 
     The head pad  11 , having the structure as described above, can allow the user of the headphone device  51  to slide the sleeve  13  with the fingers so that the sleeve  13  is drawn out of/retracted into the pad base portion  111  in the direction indicated by the arrow DR 5  in  FIG. 8 . 
     When the sleeve  13  is moved to be drawn out of/retracted into the pad base portion  111 , the engagement projection  114   b  of the pad base portion  111  elastically engages with one of the engagement recesses  133  in the engagement recess group  133 G of the sleeve  13  located at a position corresponding to the drawn/retracted amount of the sleeve  13 . The engagement between the engagement projection  114   b  and each engagement recess  133  can be released when the sleeve  13  is slid with power applied to a certain extent. 
     The user thus can feel the sense of clicking at predetermined moving intervals while moving the sleeve  13  to be drawn out of/retracted into the pad base portion  111 . The sleeve  13  is held at any position while being releasable with the fingers. 
     The sleeve length indicating portion  137 , serving as the adjusted-amount recognition part TH, is the group of the marks  137   a  aligned at regular intervals, so as to allow the user to easily recognize the drawn position of the sleeve  13 , namely, the drawn amount of the sleeve  13  by a visual check, thus allowing a highly-repeatable adjustment. 
     Aligning the predetermined pitch of the engagement recesses  133  provided on the bottom of the inner groove  136  with the predetermined interval between the respective marks  137   a  in the sleeve  13 , enhances the correlation between the drawn position and the drawn amount of the sleeve  13 , further facilitating the adjusting operation. 
     The headphone device  51  provided with both the hanger position indicators  121  and the sleeve length indicating portion  137  can allow the user to recognize both the vertical adjustment position of the hanger  21  with respect to the band  12  and the drawn position of each sleeve  13  with respect to the band  12 . 
     The headphone device  51  including the above head band  1  enables the lateral pressure adjustment in association with the change in the drawn amount of the sleeves  13  drawn out of the head pad  11 , as described above. The lateral pressure adjustment is described in detail below. 
       FIG. 1 ,  FIG. 3 , and  FIG. 4  each show a natural state of the headphone device  51  in the first, second, and third states with no power applied. The user, when putting the headphone device  51  on the head, widens the distance between the pair of the housings  31  in the right-left direction to wear the housings  31  over the ears. The head band  1  is thus elastically deformed to be widened outward in the direction in which the curvature decreases. The elastic repulsive force of the head band  1  in response to the deformation pushes the ears or temples of the user via the ear pads  32 , and the user senses the elastic repulsive force as a lateral pressure. 
     The supported position of each housing  31  on the hanger  21  shown in  FIG. 1  is referred to below as a reference point P 21  to estimate expansion/contraction deformation of the head band  1 . The distance between the reference points P 21  on the right and left sides of the pair of the housings  31  shown in  FIG. 1  is defined as distance L 0 . 
     When the headphone device  51  in the first state shown in  FIG. 1  is put on the head, the head band  1  is widened to shift the reference points P 21  to in-use reference points P 21 α outside the original reference points P 21  in the directions indicated by the arrows DR 1 . The shifted distance L 1  from each reference point P 21  to each in-use reference point P 21 α substantially corresponds to the deformed amount at the tip part of the head band  1 . The in-use reference points P 21 α are set to the outside of the reference points P 21  when the extending portions  125  of the band  12  are presumed to be formed to have a radius R 1 . 
     Since the flexural rigidity is sufficiently greater for the head pad  11 , the hanger  21 , and the sleeves  13  than for the band  12 , only the extending portions  125  of the band  12  in the head band  1  are substantially deformed. The base of the band  12  toward the sleeve head  131  in this state serves as a deformation fulcrum P 1 . 
     Since the extending portions  125  of the band  12  are deformed so as to vary in radius from the radius R 2  smaller than the radius R 1  to an in-use radius greater than the radius R 1 , the elastic repulsive force of the extending portions  125  in use is at least greater than that when the radius varies between the radius R 1  and the in-use radius upon the deformation. 
     In the natural state of the headphone device  51  in the second state as shown in  FIG. 3 , most of the extending portions  125  of the band  12  is covered with the sleeves  13 , so that the radius of curvature of the covered part is corrected to the radius R 1 . The distance L 2  between the respective reference points P 22  in this state is greater than the distance L 0  between the reference points in the first state. The reference points P 22  are thus located closer to the in-use reference points P 21 α by the distance L 22  than the reference points P 21  in the first state. 
     When the headphone device  51  in the second state is put on the head, the extending portions  125  are deformed with the radius varying from the radius R 1  to the in-use radius, resulting in a smaller degree of deformation than in the first state. The elastic repulsive force of the extending portions  125  when the headphone device  51  in the second state is in use is thus smaller than that in the first state under the similar conditions, so that the user senses a smaller lateral pressure. 
     In the natural state of the headphone device  51  in the third state as shown in  FIG. 4 , a smaller part of the extending portions  125  than in the second state is covered with the sleeves  13 , and the radius of curvature of the covered part is corrected to the radius R 1 . The corrected degree in the entire extending portions  125  in the third state is smaller than that in the second state. The distance L 3  between the respective reference points P 23  in the third state is thus greater than the distance L 0  in the first state and smaller than the distance L 2  in the second state. 
     The lateral pressure that the user senses when the headphone device  51  in the third state is in use is at a level between the first state and the second state. The user can adjust the lateral pressure to any level between the maximum and the minimum depending on the slid amount of the sleeves  13 . 
     The headphone device  51  described above enables the adjustment of the radius of curvature of the extending portions  125  of the band  12  in association with the slide of the sleeves  13 . The radius of curvature of the extending portions  125  is greater in the second state than in the first state. The degree of deformation of the extending portions  125  when the headphone device  51  is put on the head is thus smaller in the second state than in the first state, leading to a smaller elastic repulsive force. The lateral pressure that the user senses is smaller in the second state accordingly. 
     The headphone device  51  enables the lateral pressure adjustment independently of the vertical adjustment of the hangers  21 . The user thus can adjust the lateral pressure easily and precisely so as to be fitted for the shape of the head or a desirable feeling when wearing the headphone device  51 . 
     The headphone device  51  includes the hanger position indicators  121  and the sleeve length indicating portion  137 . The user thus can visually recognize the vertical adjustment position of the respective hangers  21  and the drawn amount of the respective sleeves  13  drawn out of the head pad  11 , further facilitating the lateral pressure adjustment. 
     The headphone device  51  enables the lateral pressure adjustment with the smaller number of components. 
     The headphone device  51  can also allow the user to adjust the lateral pressure only by the extension/retraction of the sleeves  13  with respect to the head pad  11 , while eliminating rotating operations such as screw rotation. The headphone device  51  thus reduces the time to adjust the lateral pressure and facilitates the adjusting operation. 
     The headphone device  51  further allows the user to separately adjust the lateral pressure of the respective right and left housings. The user thus can differently set the lateral pressure on each of the right and left sides to a desired level when the user wants to intentionally change the balance of the lateral pressure on the right and left sides or when the user wants to wear the headphone device  51  with an asymmetric hairstyle, so as to wear the headphone device  51  with a more comfortable feeling. 
     The present invention is not intended to be limited to the above-described one or more embodiments, and various modifications can be made without departing from the scope of the present invention. 
     The headphone device  51  may be modified into a headphone device  52  according to a first modified example (refer to  FIG. 3 ) in which the radius R 2  set for the extending portions  125  of the band  12  is changed to a radius greater than the radius R 1  set for the sleeves  13  and the head pad  11 . 
     The headphone device  52  of the first modified example allows the pair of the housings  31  to be most distant from each other in the state in which the sleeves  13  are slid toward the head pad  11  to the maximum, and to be closest to each other in the state in which the sleeves  13  are slid away from the head pad  11  to the maximum. 
     The headphone device  52 , when the sleeves  13  are slid toward the head pad  11  to the maximum, is in the second state for the headphone device  51  in which the deformation of the extending portions  125  in use is at the minimum. The headphone device  52 , when the sleeves  13  are slid away from the head pad  11  to the maximum, is in the first state for the headphone device  51  in which the deformation of the extending portions  125  in use is at the maximum. 
     The headphone device  52  has the same configuration as the headphone device  51  in that the radius of curvature of the extending portions  125  is corrected to the radius R 1  when the extending portions  125  are covered with the sleeves  13 .  FIG. 3  thus illustrates the headphone device  52  in the state in which the sleeves  13  are drawn out to the maximum. 
     The headphone devices  51  and  52  enable the lateral pressure adjustment in association with the slide of the sleeves  13 . Drawing the sleeves  13  out of the head pad  11  decreases the lateral pressure in the headphone device  51 , and increases the lateral pressure in the headphone device  52 . 
     The headphone devices  51  and  52  differ from each other only in the setting of the radius of curvature of the extending portions  125  of the band  12 , and have substantially the same structure. The headphone device  52  thus can facilitate the lateral pressure adjustment with a smaller number of components, as in the case of the headphone device  51 . 
     The hanger position indicators  121  and the sleeve length indicating portion  137  each serving as the adjusted-amount recognition part TH, may be configured to allow the user to recognize the respective positions either visually or tactually. 
     The headphone devices  51  and  52  are not limited to the stereo system including the paired housings  31  as described above, and may be a single ear headphone including a head band placed on the top of the head, a housing  31  corresponding to the ear on one side of the head, and a contact pad in contact with the head on the opposite side on which the other ear is exposed. 
     The headphone device  51  has been illustrated with the case in which the head band  1  is put across the top of the head, but the head band  1  may be positioned across the back of the head or across the back of the neck. The same is also applied to the case of the headphone device  52 . 
     The headphone device  51  has been illustrated with the case of including the single band  12  inserted through the head pad  11  and extending out of the head pad  11  at both ends, but is not limited to this case. For example, the headphone device  51  may include a pair of bands for each ear without penetrating the fixed wall portion  113  of the head pad  11 , each band having one end fixed to the inside and the other end connected with the hanger  21  and the housing  31 . The same is also applied to the case of the headphone device  52 . 
     The sleeves  13  in the respective headphone devices  51  and  52  are not limited to the case of completely covering the band  12  without exposing outward. For example, the sleeves  13  may each have an opening at the base  132  on which the band  12  is exposed in order to reduce the weight and improve the design and quality. The opening may be a hole such as a circular hole, a rectangular hole, and an elongated hole, or a slit cut at the edge and extending in the longitudinal direction of the base  132 . 
     The sleeves  13  in the respective headphone devices  51  and  52  are not limited to the case of being housed in the housing portions  112  in the head pad  11  and drawn out along the band  12 . For example, the sleeves  13  may be fitted to the outside of the pad base portion  111  of the head pad  11  and slidable along the band  12 . 
     A modified headphone device  52 A of a second modified example, which is either a headphone device  51 A obtained such that the headphone device  51  is subjected to the above modifications or a headphone device  52 A obtained such that the headphone device  52  is subjected to the above modifications, is described below with reference to  FIG. 9  and  FIG. 10 . 
       FIG. 9  is a front view showing the headphone device  52 A in a first state in which sleeves  13 A are slid away from hangers  21  to the maximum.  FIG. 10  is a front view showing the headphone device  52 A in a second state in which the sleeves  13 A are slid toward the hangers  21  to the maximum, as compared with the headphone device  52 A in the first state shown in  FIG. 9 . 
     The headphone device  52 A includes a head band  1 A, the hangers  21 , and housings  31 . The head band  1 A includes a head pad  11 A, a band  12 A, and the sleeves  13 A. 
     The sleeves  13 A are fitted to the outside of a pad base portion  111 A of the head pad  11 A, so as to cover the head pad  11 A in the first state shown in  FIG. 9 . The sleeves  13 A are slid in the direction indicated by the arrows DR 6  shown in  FIG. 10  so as to expose the head pad  11 A to the outside. The sleeves  13 A are slidable in the longitudinal direction while serving as the head pad  11 A. 
     The band  12 A has an arc shape having a radius R 1  at a portion housed in the head pad  11 A, and includes extending portions  125 A extending from both ends of the head pad  11 A and having an arc shape with a radius R 2  greater than the radius R 1 , as shown in  FIG. 9 . 
     As shown in  FIG. 10 , the sleeves  13 A in the first state are slid in the direction indicated by the arrows DR 6 , so as to correct the radius of curvature of the extending portions  125 A, which have a smaller flexural rigidity than the sleeves  13 A, to the radius R 1  similar to that of the sleeves  13 A. 
     The distance between the paired housings  31  in the natural state can be adjusted to be smaller, and the lateral pressure can be adjusted only by the sliding operation of the sleeves  13 A, as in the case of the headphone device  51 . 
     Next, the headphone device  51 A, in which the radius R 2  set for the extending portions  125 A of the band  12 A in the headphone device  52 A is set to be smaller than the radius R 1  set for the sleeves  13 A and the head pad  11 A, is described below as a third modified example. 
     The headphone device  51 A of the third modified example in the natural state leads the distance between the pair of the housings  31  to be minimized when the sleeves  13 A are slid to cover the head pad  11 A to the maximum, and leads the distance between the pair of the housings  31  to be maximized when the sleeves  13 A are slid away from the head pad  11 A to the maximum. 
     The headphone device  51 A corresponds to the first state for the headphone device  51  when the sleeves  13 A are slid to cover the head pad  11 A to the maximum so that the deformation of the extending portions  125 A in use is maximized. The headphone device  51 A corresponds to the second state for the headphone device  51  when the sleeves  13 A are slid away from the head pad  11 A to the maximum so that the curvature of the extending portions  125 A in use is minimized. 
     The headphone device  51 A has the same configuration as the headphone device  52 A in that the radius of curvature of the extending portions  125 A is corrected to the radius R 1  of the sleeves  13 A when the extending portions  125 A are covered with the sleeves  13 A.  FIG. 10  thus illustrates the headphone device  51 A in the state in which the sleeves  13 A are slid away from the head pad  11 A to the maximum. 
     The headphone devices  51 A and  52 A described above enable the lateral pressure adjustment in association with the slide of the sleeves  13 A. Sliding the sleeves  13 A away from the head pad  11 A decreases the lateral pressure in the headphone device  51 A, and increases the lateral pressure in the headphone device  52 A. 
     The headphone devices  51 A and  52 A differ from each other only in the setting of the radius of curvature of the extending portions  125 A of the band  12 A, and have substantially the same structure. The headphone device  51 A thus can facilitate the lateral pressure adjustment with a smaller number of components, as in the case of the headphone device  52 A. 
     While the head pad  11  and the sleeves  13  slid along the head pad  11  have the arc shape so as to allow a smooth slide, the head pad  11  and the sleeves  13  do not necessarily have exactly the arc shape and may have any shape that allows a slide between the head pad  11  and the sleeves  13 . The extending portions  125  of the band  12 , which are corrected by the sleeves  13 , are only required to have a curved shape, instead of the completely arc shape. 
     Although the head pad  11 , the sleeves  13 , and the band  12  have been illustrated above with the shapes with a radius R 1  or R 2 , each radius can be replaced with a radius of curvature when each element does not have a completely arc shape but have a curved shape. The radius of curvature of each element, when greatly varying depending on the portion (from the end portion to the middle portion, for example), may be replaced with an average radius of curvature. 
     The headphone devices  51  and  52  in which the sleeves  13  are fitted to the inside of the head pad  11 , and the headphone devices  51 A and  52 A in which the sleeves  13 A are fitted to the outside of the head pad  11 A, can facilitate the lateral pressure adjustment in association with the slide of the sleeves  13  or  13 A made by fingers.