Abstract:
An ear-hanging type speakerphone unit that allows users to listen to both sounds from the speaker and sounds from the outside environment, while suppressing leakage of the sounds emanating from the speaker to the outside environment, is provide for. A directional speaker is adjustably held with its speaker face being, for example, approximately 1 to 2 cm. away from the opening of an external auditory miatus, such that an open air space is formed between the speaker face and the opening of the miatus.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a body set type speaker unit that outputs sound reproduced from audio equipment, voice output from communication equipment, etc., and more particularly to a body set type speaker unit which allows users to listen to sound therefrom, while assuring continued hearing of the outside sound, concurrently.  
           [0003]    2. Description of the Related Art  
           [0004]    It is known that earphones and headphones are common devices used by many to listen to sound from a variety of electronic devices including but not limited to audio equipment, personal computers, communication equipment, cellular phones, etc. It is also generally recognized that the physical size of these devices often causes these devices to be readily visible. For instance, a person listening to the sound of a radio broadcast from a small radio with a built-in speaker, often places the radio receiving portion of the device in proximity to a convenient pocket of a user&#39;s article of clothing (e.g., a user&#39;s shirt pocket), resulting in both a casual observer and a user easily recognizing that a device is physically present in the user&#39;s clothing.  
           [0005]    When certain other of these devices are used by a user, particularly with reference to devices utilizing earphones or headphones, one or more of the user&#39;s auditory canals is often blocked or “closed-off” from the outside environment by the physical presence of the earphone or speakerphone portion of the device such that the user is unable to hear or listen to sounds of the outside environment. As a result, the user of these types of devices is often only able to listen to the sound being produced from the speaker component of the device.  
           [0006]    In contrast, where a user of a device having a built-in speaker is listening to sound from a speaker placed near to but not closing off his ear, such as near a breast pocket, hearing of the outside environmental sound is assured. However, in these types of devices having a built-in speaker, the quality and clarity of the sound produced from the speaker is often detrimentally affected due to the sound waves being scattered as a result of interference of sounds and noises present in the outside environment.  
           [0007]    In other situations, a user may listen to the outside sound via one ear and sounds from a device via a single earphone placed on the other ear (i.e., a mono system). However, in these situations where a user&#39;s respective ears receive different sounds from different sources (e.g., such as the speaker sound in one ear and the outside sound in the other ear) the user often experiences a sense of incompatibility that often causes the auditory nerve to fatigue. In the situation where a user listens to speaker sounds in stereo, such that each ear has an earphone placed thereon to allow a user&#39;s ears to hear similar sounds from a common source, it is known that it is fairly difficult to listen to the outside sounds concurrently with the stereo sounds produced via the conventional earphones or headphones.  
         SUMMARY OF THE INVENTION  
         [0008]    An object of the present invention is to provide a body set type speaker apparatus which allows a user to listen to both the outside sound and the sound emanating from the speaker, while limiting the leakage of the sound emanating from the speaker to the outside environment.  
           [0009]    A body set type speaker unit comprising a mounting member detachably mountable on a user, and a directional speaker having a speaker face which is positionable such that the face may be securely positioned at a predetermined distance away from a user&#39;s ear by a speaker hold member, wherein said speaker hold member securely positions said directional speaker at said predetermined distance away from a user&#39;s ear to form an air gap having a distance as between said ear and said face.  
           [0010]    Although the term body set type speaker unit is typically a head set type, the expression “body set type” as used herein is defined to include but not be limited to a head set type, a face set type, a shoulder set type, a trunk set type, an arm set type, etc., wherein the terms “unit” and “apparatus” are intended to be used interchangeably without augmentation of definition. Provided a body set type speaker unit comprises a directional speaker having sufficient directivity, the speaker can prevent the leakage of the sound emanated from a speaker to the outside environment, so as to sufficiently suppress the interference of external noise (i.e., noise not emanating from the speaker) with the sound emanating from the speaker, even when the unit is at a predetermined distance away from the user&#39;s ear or auditory canal. However, the leakage of the speaker sound to the outside can be prevented regardless of a slight reduction in directivity, if the directional speaker is disposed as near to the user&#39;s ear as is possible, while assuring a formation of the external open space between the directional speaker and the ear. As used herein, the terms “ear hole” and “ear canal” are used interchangeably without reservation wherein each is defined to include, for example, the opening of an external auditory miatus.  
           [0011]    The speaker sound (i.e., the sound emanating from a speaker) includes but is not limited to be: the sound reproduced by a record player from sound recorded on an optical disk (such as a CD, an MD, a DVD, etc.), IC memory, or other electronic or digital media; the broadcast sound output from a tuner for a radio, television, or other entertainment device; the sound output from a personal computer (PC) or other electronic device; the voice output from a portable telephone or communication equipment which occurs during conversion, and the like. The user includes PC operators, and respondents in support centers responding to inquiries about products or services received by telephone.  
           [0012]    The body set type speaker unit usually “receives” these sounds by a conductive or radiated means such as wire or radio, respectively. However, in the case where the speaker unit is equipped integrally with a small tuner, a telephone, and communication equipment so that the directional speaker can output sound, a device for receiving an external signal by radio or wire can be omitted.  
           [0013]    Since the external open space (a.k.a. an “air gap”) is formed between the ear and the directional speaker, the ear is not closed off from the outside and therefore the outside sound reaches the ear through the external open space. In other words, sound waves from the outside environment reach the miatus without being physically obstructed by the presence of a speaker or earphone device in direct contact with the ear. As a result, the user can listen to both the speaker sound and the outside sound, simultaneously. In addition, the directional speaker meets the directivity requirement (in which, when the speaker face is directed toward the ear hole of the user, a ratio, equivalent to that of the sound energy radiated from the speaker face to the ear hole in relation to the total sound energy radiated from the speaker face, is of a predetermined value or greater). This can effectively prevent the leakage of the speaker sound to the outside. Because hearing of the outside sound has been guaranteed, the user can set the body set type speaker unit to the user&#39;s body only when listening to a musical piece, or during telephone conversion, and the user can omit the operation of removing the body set speaker unit when not used, and listen to the speaker sound from the body set type speaker unit as necessary, while holding the speaker unit set to the user&#39;s body without interruption.  
           [0014]    According to the body set type speaker unit of another aspect, the speaker hold member in the first body set type speaker unit holds the directional speaker so that a distance from the directional speaker to the user&#39;s ear can be adjusted.  
           [0015]    As a distance from the directional speaker to the ear hole can be adjusted, the body set speaker unit can be used in conformity with the form or preference of the user. In addition, the user can make adjustments to a sound-volume ratio of the outside sound and the speaker sound by changing the air gap distance as measured between the directional speaker and the ear hole. Note that if the body set type speaker unit is equipped with volume adjustment means for adjusting the sound volume of the speaker sound, the user can adjust the sound-volume ratio of the speaker sound and the outside sound as appropriate, by operating the volume adjustment means.  
           [0016]    According to the body set type speaker unit of another aspect, the speaker hold member in adjustably holds the directional speaker so that direction of the directional speaker can be adjusted.  
           [0017]    Since the direction of the directional speaker can be adjusted, the body set speaker unit can be used in conformity with the form or preference of the user. In addition, the user can make adjustments to a sound-volume ratio of the outside sound and the speaker sound as appropriate, by changing the direction of the directional speaker.  
           [0018]    According to the body set type speaker unit of another aspect, an audio signal which is output by the directional speaker may be used to generate sound, wherein the audio signal may be a signal that is received by conductive or wave transmission means. As an example, a conductive means may include a wire or other physically conductive device, whereas a wave transmission means may include a radio transmission, satellite transmission and the like.  
           [0019]    According to the body set type speaker unit of another aspect, the unit may further comprise a bone-conduction type speaker for transmitting a sound having a frequency of a predetermined value or less to the user through a bone-conduction via contact with the user.  
           [0020]    The expression “sound having a frequency of a predetermined value or less” as used herein is used to include but not be limited to sounds which are typically low in pitch. The predetermined value is, for example, about 250 Hz or less, and is preferably approximately 150 Hz or less. Since the distance that the low-pitched sound can reach is short when compared with a high-pitched sound, if the distance from the directional speaker to the user&#39;s ear hole becomes slightly longer, it would conceivably be difficult for the user to sufficiently listen to the low-pitched sound. In the present invention, this body set type speaker unit provides that the user can reliably listen to the low-pitched sound as the low-pitched sound is transmitted to the user by the bone-conduction type speaker when in contact with the user.  
           [0021]    In the body set speaker unit of another aspect, the body set type speaker unit further comprises an urging member for generating an urging force of pressing the bone-conduction type speaker in contact with the user&#39;s body.  
           [0022]    Preferably, the urging member comprises a compression coil spring separate and apart from the speaker hold member. In the alternative, it is also envisioned that the speaker hold member may be made from a member, which has a predetermined spring force, such as a plate spring, etc. In this case the speaker hold member also functions as the urging member.  
           [0023]    In any of the aspects herein, the body set type speaker unit may further comprise a microphone for communication, recording of user&#39;s voice, etc.  
           [0024]    Further, it is envisioned by the inventors that the present invention is not limited to an apparatus having only a single directional speaker; the present invention is preferably comprised of at least one directional speaker such that a preferred embodiment comprises two directional speakers wherein there is a directional speaker available for each ear of a user. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]    [0025]FIG. 1 is a schematic diagram showing an ear-hanging type speakerphone unit in the set state;  
         [0026]    [0026]FIG. 2 is a rear view of the ear-hanging type speakerphone unit  10  shown together with a cross-section of an ear at a position of an external auditory miatus  18  along the anteroposterior axis;  
         [0027]    [0027]FIG. 3 is a perspective view showing a glasses-attaching type speakerphone unit attached to glasses;  
         [0028]    [0028]FIG. 4 is a schematic diagram showing a helmet type speakerphone unit;  
         [0029]    [0029]FIG. 5 is a schematic diagram showing a cap type speakerphone unit; and  
         [0030]    [0030]FIG. 6 is a perspective view showing a hair band type speakerphone unit.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0031]    [0031]FIG. 1 shows an ear-hanging type speakerphone unit  10  in the set state; FIG. 2 is a rear view of the ear-hanging type speakerphone unit  10  shown together with a cross-section of an ear at a position of an external auditory miatus  18  along the anteroposterior axis. An ear hanging portion  11  is formed into a curved shape conforming to the contour of the rear side of the proximal portion of the concha of an ear  12  so it can be hung on the rear side of the proximal portion of the concha. A rising portion  13  rises upward from the lower end of the ear  12  in a vertical direction, the upper end reaching approximately the height of the external auditory miatus  18 . A universal joint portion  16  is provided on the upper end portion of the rising portion  13 . A stay  23  is coupled at one end thereof with the universal joint portion  16  so that it is free to rotate in a three-dimensional direction, and fixes an ultra directional speaker  17  at the other end. The ultra directional speaker  17  has a flat speaker face  24  and a bulged portion extending to the opposite side of the speaker face  24 . The rotation of the stay  23  with respect to the universal joint portion  16  renders it possible to adjust the position of the ultra direction speaker  17  in the vertical, lateral, and fore-and-aft directions in a predetermined range and to adjust both a distance from the stay  23  to the external auditory miatus  18  and the direction of the stay  23 . An opening  19  forms an opening (ear hole) through which the external auditory miatus  18  is connected with the outside, and gradually increases its diameter toward the outside.  
         [0032]    The speaker face  24  is positioned, for example, 1 to 2 cm away from the circumferential edge of the opening  19  in the horizontal direction. For the directivity of the ultra directional speaker  17 , a directional speaker is adopted in which, when the speaker face  24  is a predetermined distance away from the opening  19  and directed toward the opening  19 , a ratio of the sound energy E a  radiated from the speaker face  24  to the opening  19  and the total energy E t  radiated from the speaker face  24  (E a /E t ) is a sufficiently great value E r  (near to 1) or greater than E a /E t  (E a /E t &gt;E r ). The ultra directional speaker  17  may be any one of a variety of commercially-available microspeakers. Such microspeakers are normally about 20 mm or so in opening diameter and a few grams in weight. These microspeakers can also be provided with a reflector as necessary to further enhance directivity. An external open space  26  is formed between the opening  19  and the speaker face  24  so that the outside sound can be transmitted from the external open space  26  through the opening  19  and to the external auditory miatus  18 .  
         [0033]    A bone-conduction type speaker  29  is attached to the upper end portion of the ear-hanging portion  11  so it can contact a side face  14  of the user at a forward and obliquely upward position with respect to the universal joint portion  16 . The bone-conduction type speaker  29  has a pressing portion  28 , which is pressed against the side face  14 , for outputting sound waves, and a housing portion  30  covering the opposite face of the pressing portion  28  from the side face  14  so it can freely rotate in the direction of arrow A with respect to the pressing portion  28 . The upper end portion of the ear-hanging portion  11  is curved into a predetermined shape so that when the ear-hanging portion  11  is hung on the ear  12 , a force of pressing the bone-conduction type speaker  29  against the side face  14  of the user will be developed by the restoring force of the curved shape. This causes the bone-conduction type speaker  29  to be pressed against the side face  14  with a predetermined pressing force and the sound waves from the bone-conduction type speaker  29  to be transmitted efficiently to a facial bone  36  directly under the side face  14 . A plastically deformable tube  31  is secured at its upper end portion to the housing portion  30 , and the user can plastically deform the tube  31  into an arbitrary shape with his fingers. A microphone  32  is secured at its lower end portion to the plastically deformable tube  31 . The user plastically deforms the plastically deformable tube  31  to change the position of the microphone  32  so that the microphone  32  is near his mouth when using it and away from his mouth when not using. Note that the interior of the plastically deformable tube  31  is wired to transfer a signal input through the microphone  32 .  
         [0034]    While the ear-hanging type speakerphone unit  10  is equipped with only a single ultra directional speaker  17  for one ear, it may be equipped with two ultra directional speakers  17  for both ears. Even in the case of two ultra directional speakers  17  in total, the speakerphone unit  10  is normally equipped with a single bone-conduction type speaker  29  and a single microphone  32 . Also, even in the case where the ear-hanging type speakerphone unit  10  is equipped with only a single bone-conduction type speaker  29 , the contact position of the housing portion  30  with the user&#39;s body is not limited to the lateral center position on the body, but may be a position offset laterally from the lateral center position. The ear-hanging type speakerphone unit  10  is supplied with sounds by a predetermined sound source, which is not equipped in the speaker unit  10  itself. The sound source supplies sounds to the speakerphone unit  10  through the ultra directional speaker  17  and the bone-conduction type speaker  29  by radio or wire. A sound source like this may be a reproducer for an optical disk (such as a CD, an MD, a DVD, etc.) or IC memory, a tuner for a radio or television, a personal computer, a portable telephone, a desk telephone, etc. Although not shown, an on-off switch for sound output from the ultra directional speaker  17  or bone-conduction type speaker  29 , and an adjustment portion for adjusting the volume of the sound output from the ultra directional speaker  17  or bone-conduction type speaker  29 , in addition to those provided in a personal computer or record player, may be equipped in the ear-hanging speakerphone unit  10 .  
         [0035]    Sounds other than a low-pitched sound, for example, a sound of frequency is of 150 Hz or greater is radiated from the speaker face  24  of the ultra directional speaker  17  toward the external auditory miatus  18 . Although the sound volume of the radiated sound is extremely small, the ultra directional speaker  17  has sufficient directivity, and in addition, the sound volume of the radiated sound arriving from the speaker face  24  at the external auditory miatus  18  is greater than a standard sound. As a result, the user can listen to the sound from the ultra directional speaker  17  without difficulty. On the other hand, since the external auditory miatus  18  is open to the outside through the opening  19  and the external open space  26  without being closed off, the outside sound reaches the external auditory miatus  18  via the external open space  26  and the opening  19  and is recognized by the user of the ear-hanging speakerphone unit  10 . In this manner, the user can listen to the outside sound, while listening to the speaker sound from the ultra directional speaker  17 . The user rotates the stay  23  on the center point of the universal joint portion  16  in the three-dimensional direction, thereby being able to adjust the direction of the speaker face  24 , a distance from the speaker face  24  to the opening  19 , and furthermore, the vertical, lateral, and fore-and-aft positions of the ultra directional speaker  17  in a predetermined range. This adjustment is beneficial in conforming the direction and position of the ultra directional speaker  17  to the form of the user and also makes a contribution to adjustments to the volume ratio between the outside sound and the speaker sound which the user hears. The sound of frequency of 150 Hz or less (hereinafter referred to as a “low-pitched sound”) is output from the bone-conduction type speaker  29  to the side face  14  by contact vibration. This low-pitched sound is transferred to a facial bone  36  directly under the side face  14  and recognized by the user. The bone-conduction type speaker  29  is pressed against the side face  14  with sufficient force by the spring force of the upper end portion of the ear-hanging portion  11 . When using the microphone  32 , the user plastically deforms the plastically deformable tube  31 , thereby moving the microphone  32  to a position proper from the user&#39;s mouth.  
         [0036]    [0036]FIG. 3 shows a perspective view of a glasses-attaching type speakerphone unit  45  attached to glasses  40 . In FIG. 3 and the figures thereafter, an ultra directional speaker  17 , a bone-conduction type speaker  29 , a plastically deformable tube  31 , and a microphone  32  are the same structure as those in the ear-hanging type speakerphone unit  10  (FIGS. 1 and 2), so the same reference numerals as those of the ear-hanging type speakerphone unit  10  are applied. While the glasses-attaching type speakerphone unit  45  is equipped with only a single ultra directional speaker  17 , it may be equipped with two ultra directional speakers  17  for both ears. Even in the case of two ultra directional speakers  17  in total, the speakerphone unit  45  is normally equipped with a single bone-conduction type speaker  29  and a single microphone  32 . The glasses-attaching type speakerphone unit  45  is detachably attached, as appropriate, to the glasses  40  and is detachably set to the user&#39;s face through the glasses  40 . The glasses  40  have right and left side frame portions  42 , and right and left side frame portions  42  extending rearward from the outer ends of the right and left side frame portions  42 . The glasses-attaching type speakerphone unit  45  has a mounting portion  47 , which is in turn equipped at the outer face with a hook  48  that is hung on the rear end portion of the side frame portion  42 . The position at which the hook  48  is hung on the side frame portion  42  may be any position on the side frame portion  42 . A plastically deformable arm  50  projects obliquely downward from the mounting portion  47 , the ultra directional speaker  17  being secured to the lower end portion of the plastically deformable arm  50 . The user plastically deforms the plastically deformable arm  50  as appropriate, thereby adjusting the direction of the ultra directional speaker  17 , a distance from the ultra directional speaker  17  to an external auditory miatus  18 , and the vertical, lateral, and fore-and-aft positions of the ultra directional speaker  17 . The lower end portion of the mounting portion  47  is curved toward the user_s face with respect to the upper end so that when the user puts the glasses  40  on his face, the bone-conduction type speaker  29  is pressed against a user&#39;s side face  14  with a predetermined pressing force. The plastically deformable tube  31  extends from the bone-conduction type speaker  29 , the microphone  32  being secured to the lower end portion. Plastic deformation of the plastically deformable tube  31  can adjust the position of the microphone  32 .  
         [0037]    [0037]FIG. 4 shows a schematic diagram of a helmet type speakerphone unit  55 . While this helmet type speakerphone unit  55  is used by a two-wheeled vehicle rider, the same structure is also applicable to helmets for factories, civil engineering works, and building sites. While the helmet type speakerphone unit  55  is equipped with only a single ultra directional speaker  17  for one ear, it may be equipped with two ultra directional speakers  17  for both ears. Even in the case of two ultra directional speakers  17  in total, the speakerphone unit  55  is normally equipped with a single bone-conduction type speaker  29  and a single microphone  32 . A compression coil spring  58  is secured at its upper end to the top of the inner surface of a helmet  56  and tangles to its lower end. The bone-conduction type speaker  29  is secured to the lower end of the compression coil spring  58 . In mounting the helmet  56  on the head portion of the user, bands (not shown) is tied under the chin. As a result, the helmet  56  is pressed against the head portion and the compression coil spring  58  is compressed, whereby bone-conduction type speaker  29  is pressed against the user_s head portion with a predetermined urging force. A stay  60  is secured at its upper end portion to the left lower end portion of the helmet  56  and protrudes downward by a predetermined length. Attached to the lower end portion of the stay  60  is the ultra directional speaker  17 . The direction of the ultra directional speaker  17  and the distance from the ultra directional speaker  17  to the external auditory miatus  18  are adjusted by plastic deformation of the stay  60 . A plastically deformable tube  31  is secured at its upper end portion to the ultra directional speaker  17  and extends downward from the ultra directional speaker  17 , a microphone  32  being attached to the lower end portion.  
         [0038]    [0038]FIG. 5 shows a perspective view of a cap type speakerphone unit  66 . While the cap type speakerphone unit  66  is equipped with only a single ultra directional speaker  17  for one ear, it may be equipped with two ultra directional speakers  17  for both ears. Even in the case of two ultra directional speakers  17  in total, the speakerphone unit  66  is normally equipped with a single bone-conduction type speaker  29  and a single microphone  32 . A cap  67  is woven from cloth and consists of a peak portion and a head covering portion. The bone-conduction type speaker  29  is secured to the inner surface of the head covering portion of the cap  67 , for example, the left inner surface. If the user wears the cap  67 , the bone-conduction type speaker  29  is pressed against his head portion with a predetermined force. A stay  60  in this example is present on the same side of the bone-conduction type speaker  29  at the head covering portion of the cap  67 . The stay  60  is secured at its upper end portion to the lower end portion of the head covering portion of the cap  67  and tangles from the cap  67  by a predetermined length. The ultra directional speaker  17  is attached to the lower end portion of the stay  60 . Plastic deformation of the stay  60  renders it possible to adjust the vertical, lateral, and fore-and-aft positions of the speaker face  24 , the direction of the speaker sound, and a distance from the speaker sound to the external auditory miatus  18 . A plastically deformable tube  31  with a predetermined length is secured at its upper end portion to the ultra directional speaker  17 , a microphone  32  being attached to the lower end portion.  
         [0039]    [0039]FIG. 6 shows a perspective view of a hair band type speakerphone unit  71 . While the hair band type speakerphone unit  71  is equipped with only a single ultra directional speaker  17  for one ear, it may be equipped with two ultra directional speakers  17  for both ears. Even in the case of two ultra directional speakers  17  in total, the speakerphone unit  71  is normally equipped with a single bone-conduction type speaker  29  and a single microphone  32 . A hair band  72  has an elastic force as a restoring force when expanded. The bone-conduction type speaker  29  is secured to a predetermined portion of the inner surface of the hair band  72 . When the user wears the hair band  72 , the bone-conduction type speaker  29  is pressed against the head portion of the user by the elastic force of the hair band  72 , and low-pitched sounds are transmitted to a predetermined bone of the user_s head portion. A stay  60  is secured at its one end portion to the left end portion of the hair band  72  and projects forward in an obliquely downward direction. The ultra directional speaker  17  is attached to the other end portion of a stay  60 . Plastic deformation of the stay  60  makes it possible to adjust the vertical, lateral, positions of the speaker face  24 , the direction of the speaker sound, and a distance from the speaker sound to the external auditory miatus  18 . A plastically deformable tube  31  with a predetermined length is secured at its upper end portion to the ultra directional speaker  17 , a microphone  32  being attached to the lower end portion.