Patent Publication Number: US-10334342-B2

Title: Neckband wireless sound transducer

Description:
PRIORITY CLAIM 
     The present application claims priority to Korean Patent Application No, 10-2016-0101468 filed on 9 Aug. 2016, the content of said application incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present invention relates to a neckband-type wireless sound transducer, and more particularly, to a neckband-type wireless sound transducer that prevents sound from being transferred to the surroundings of the wearer. 
     BACKGROUND 
     As a multimedia such as a broadcasting phone or a PMP phone has been built in a smartphone as a main function, the user can enjoy various contents through their smartphone. The demand for a wireless headset has also been increasing with these trends. 
     Among the wireless communication techniques, Bluetooth, which is a standard for wireless communication between wireless communication devices at a short distance with low power, serves to process data transmission between devices such as a computer, a smartphone, a headset, a personal digital assistant (PDA), a personal computer (PC), and a printer. Bluetooth is a communication technology that can transmit and receive data wirelessly, usually between 10 meters and maximally several hundred meters. A neckband-type speaker for reproducing sound, with being worn around the wearer&#39;s neck, without a separate communication cable, has been developed using such a technology and sold on the market. 
     In addition, the sound generated by the conventional neckband-type speaker is transmitted not only to the wearer but also to the surroundings of the wearer, which disturbs the wearer listening to the sound and unwantedly transfers the sound to the people around the wearer. 
     SUMMARY 
     An object of the present invention is to provide a neckband-type wireless sound transducer that prevents sound from being transferred to the surroundings of the wearer or in an outward direction from the sound transducer. 
     According to an aspect of the present invention, there is provided a neckband-type wireless sound transducer, including: a main body part which is seated on a human body; a main speaker part which is mounted on the main body part and emits sound to the inside of the main body part; an auxiliary speaker part which is mounted on the main body part and emits sound for leakage reduction to offset the sound emitted by the main speaker part and leaked to the outside of the main body part; and a controller which applies an electric signal for sound emission to the main speaker part and an electric signal for leakage reduction to the auxiliary speaker part. 
     In some embodiments, at least one speaker included in the main speaker part and at least one speaker for reduction included in the auxiliary speaker part are preferably symmetrical with respect to the center of the main body part. 
     In some embodiments, the speaker for reduction preferably emits sound for leakage reduction toward the outside of the main body part. 
     In some embodiments, the controller preferably applies the electric signal for leakage reduction to the speaker for reduction after a delay time proportional to an interval between the speaker of the main speaker part and the speaker for reduction. 
     In some embodiments, the delay time is preferably calculated as (the interval)/(sound speed). 
     In some embodiments, the electric signal applied to the speaker of the main speaker part and the electric signal for leakage reduction are preferably opposite in phase to each other. 
     In some embodiments, at least one speaker included in the main speaker part is preferably provided in a groove formed in the main body part. 
     In some embodiments, the groove formed in the main body part is preferably inclined in a direction toward the center of the main body part. 
     According to the present invention, there are the effects of improving the directivity to the wearer&#39;s auditory organ and preventing sound from being transferred to the surroundings of the wearer or in an outward direction from the sound transducer, thus ensuring only the wearer to appreciate the sound and preventing the sound from being unwantedly transferred to the people around the wearer. 
     Those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a neckband-type wireless sound transducer according to the present invention. 
         FIGS. 2 a  and 2 b    are a top view and a perspective view of the neckband-type wireless sound transducer of  FIG. 1 . 
         FIG. 3  is an explanatory view of a leakage reduction principle of the neckband-type wireless sound transducer of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a preferred embodiment of a neckband-type wireless sound transducer according to the present invention will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a block diagram of a neckband-type wireless sound transducer according to the present invention, and  FIGS. 2 a  and 2 b    are a top view and a perspective view, respectively, of the neckband-type wireless sound transducer of  FIG. 1 . 
     The neckband-type wireless sound transducer includes a power supply part  1  which supplies power, a display part  3  which displays information (operation state, charging state, volume level, played music information, etc.) to the user, an input part  5  which acquires an input (operation control/stop control, volume level adjustment control, played music selection, etc.) from the user, a main speaker part  7  which is mounted on a main body part  100 , disposed toward the wearer&#39;s auditory organ, and composed of first to sixth speakers  7   a  to  7   f , an auxiliary speaker part  9  which is mounted on the main body part  100  and composed of first to sixth speakers  9   a  to  9   f  for reduction that serve to reduce the sound generated by the main speaker part  7  and leaked(or emitted) to the outside of the main body part, a wireless communication part  11  which performs wireless communication (e.g., Bluetooth communication, Wi-Fi communication, etc.) with an external electric communication device, a connection part  13  which is connected to the external electric communication device by wire, and a controller  20  that receives power from the power supply part  1 , receives sound data through the wireless communication part  11  according to the input from the input part  5 , and plays and emits sound through the main speaker part  7 , or receives sound data from the connection part  13  and plays and emits sound through the main speaker part  7 , the controller  20  generating and emitting sound for leakage reduction through the auxiliary speaker part  9  so as to reduce sound leakage to the outside of the main body part (i.e., to the surroundings of the wearer) and displaying information such as operation state through the display part  3 , when emitting the sound through the main speaker part  7 . Here, it is noted that the power supply part  1 , the display part  3 , the input part  5 , the wireless communication part  11  and the connection part  13  are easily recognized by those skilled in the art, so the detailed description thereof is omitted. 
     In addition, the neckband-type wireless sound transducer according to the present invention includes an annular main body part  100  having a first end  101   a  and a second end  101   b , an opening being formed between the first end  101   a  and the second end  101   b  of the main body part  100 . The main body part  100  is provided with first to sixth sound-emitting grooves  110   a  to  110   f  (collectively referred to as ‘ 110 ’), each having a plurality of sound-emitting holes  111 , the sound-emitting grooves  110  being formed in the main body part  100  in a stepped or concave manner with respect to the surface of the main body part  100 , groove ends  112   a  and  112   b  facing each other being formed on both sides of the sound-emitting grooves  110  to allow the sound generated by the first to sixth speakers  7   a  to  7   f  to be emitted in a straightforward manner to the wearer&#39;s auditory organ. Alternatively, it is also possible to provide a dish-shaped structure that surrounds the entire peripheries of the sound-emitting grooves  110  and is opened toward the upper space of the center O (or toward the wearer&#39;s auditory organ) to improve the straightforward emission of the sound. 
     The first to sixth speakers  7   a  to  7   f  are mounted in the sound-emitting grooves  110   a  to  110   f  (in the main body part  100 ), respectively, and the sound (or audio) from the first to sixth speakers  7   a  to  7   f  is transferred to the outside or the wearer&#39;s auditory organ through the sound-emitting holes  111 . The first and sixth sound-emitting grooves  110   a  and  110   f  are symmetrically arranged with respect to the center O of the main body part  100 , and also the second and fifth sound-emitting grooves  110   b  and  110   e , and the third and fourth sound-emitting grooves  110   c  and  110   d , are symmetrical with respect to the center O of the main body part  100 , respectively. As shown in  FIG. 2 b   , the sound-emitting grooves  110  are inclined in a direction toward the center of the main body part  100  at a certain angle to the horizontal direction, and the inclined sound-emitting grooves  110  allow the sound-emitting holes  111  to be directed toward a higher part than the center O of the main body part  100 , for example, toward the wearer&#39;s auditory organ. 
     The lower portion of the main body part  100  is seated on the user&#39;s back, shoulders, neck, etc., such that the sound-emitting holes  111  are structurally directed toward the user&#39;s auditory organ. 
     Moreover, the main body part  100  includes first to sixth sound-emitting grooves  120   a  to  120   f  for reduction, each having a plurality of sound-emitting holes  111 , through which the sound for leakage reduction from the first to sixth speakers  9   a  to  9   f  for reduction is emitted. The first to sixth sound-emitting grooves  120   a  to  120   f  for reduction are disposed toward the outside of the main body part  100  to emit the sound to the outside of the main body part  100 . The first and sixth sound-emitting grooves  120   a  and  120   f  for reduction are symmetrically arranged with respect to the center O of the main body part  100 , and also the second and fifth sound-emitting grooves  120   b  and  120   e  for reduction, and the third and fourth sound-emitting grooves  120   c  and  120   d  for reduction, are symmetrical with respect to the center O of the main body part  100 , respectively. 
     Further, the first sound-emitting groove  110   a  and the sixth sound-emitting groove  120   f  for reduction are symmetrical with respect to the center O, and also the second sound-emitting groove  110   b  and the fifth sound-emitting groove  120   e  for reduction, the third sound-emitting groove  110   c  and the fourth sound-emitting groove  120   d  for reduction, the fourth sound-emitting groove  110   d  and the third sound-emitting groove  120   c  for reduction, the fifth sound-emitting groove  110   e  and the second sound-emitting groove  120   b  for reduction, and the sixth sound-emitting groove  110   f  and the first sound-emitting groove  120   a  for reduction are symmetrical with respect to the center O, respectively. 
     The center (middle) of the opening corresponds to the middle between the first end  101   a  and the second end  101   b , and the main body part  100  is formed symmetrically with respect to a first extension line connecting the center of the opening and the center O of the main body part  100 . The opening is disposed in a frontal face direction of the wearer, as indicated by an arrow of  FIG. 2   a.    
     The first to sixth speakers  7   a  to  7   f  are mounted in the main body part  100 , corresponding to the first to sixth sound-emitting grooves  110   a  to  110   f , respectively, and controlled separately or together by the controller  20 . The first to sixth speakers  7   a  to  7   f  emit sound in an inward direction of the main body part  100  (toward the center O) so that the sound can reach the wearer&#39;s auditory organ positioned on the inside of the main body part  100 . Furthermore, for example, for 2.1 channel, the first and second speakers  7   a  and  7   b , and the fifth and sixth speakers  7   e  and  7   f , may be woofer speakers, while the third speaker  7   c  and the fourth speaker  7   d  may be right and left speakers, respectively. 
     The first to sixth speakers  9   a  to  9   f  for reduction are mounted in the main body part  100 , corresponding to the first to sixth sound-emitting grooves  120   a  to  120   f  for reduction, respectively, and controlled separately or together by the controller  20 . The first speaker  9   a  for reduction prevents the sound from the sixth speaker  7   f , which is symmetrically positioned thereto with respect to the center O, from being leaked to the outside of the main body part  100 , the second speaker  9   b  for reduction prevents the sound from the fifth speaker  7   e , which is symmetrically positioned thereto with respect to the center O, from being leaked to the outside of the main body part  100 , the third speaker  9   c  for reduction prevents the sound from the fourth speaker  7   d , which is symmetrically positioned thereto with respect to the center O, from being leaked to the outside of the main body part  100 , the fourth speaker  9   d  for reduction prevents the sound from the third speaker  7   c , which is symmetrically positioned thereto with respect to the center O, from being leaked to the outside of the main body part  100 , the fifth speaker  9   e  for reduction prevents the sound from the second speaker  7   b , which is symmetrically positioned thereto with respect to the center O, from being leaked to the outside of the main body part  100 , and the sixth speaker  9   f  for reduction prevents the sound from the first speaker  7   a , which is symmetrically positioned thereto with respect to the center O, from being leaked to the outside of the main body part  100 . 
     The power supply part  1 , the wireless communication part  11  and the controller  20  are mounted on the inside of the main body part  100 , while the display part  3 , the input part  5  and the connection part  13  are provided on the side surfaces of the main body part  100  to be externally shown. 
     The controller  20  receives sound data (e.g., MP3, MP4, audio data, etc.) from an electric communication device (e.g., smartphone, MP3 player, etc.) through the wireless communication part  11  and converts it into an electric signal playable by the speaker part  7 , using a built-in playing program such as Codec. Upon the conversion into the electric signal, the controller  20  may convert the sound data into an electric signal which is a stereo signal or into an electric signal which is a multi-channel channel signal for multi-channel play (e.g., 2.1 channel, 3.1 channel, 4.1 channel, 5.1 channel, etc.). For the purpose of converting the sound data into the electric signal, the controller  20  receives an input for selection of a sound type (e.g., stereo, multi-channel, etc.) from the input part  5  and controls the built-in playing program according to the input for selection. 
     The controller  20  generates an electric signal for sound playing and applies the electric signal to the speaker part  7  so that it can play sound. Particularly, in the case of stereo playing or multi-channel playing, the controller  20  applies the same or different electric signals to the first to sixth speakers  7   a  to  7   f  or selectively applies the electric signals to the first to sixth speakers  7   a  to  7   f , so that they can play sound. 
     In addition, in order to prevent the sound emitted by the speaker part  7  from being leaked to the outside of the main body part  100  so that people other than the wearer could hear the sound, the controller  20  controls the sixth to the first speakers  9   f  to  9   a  for playing to emit, to the outside of the main body part  100 , the sound having the opposite phase to the sound emitted by the first to sixth speakers  7   a  to  7   f . Hereinafter, this process will be described in detail. 
       FIG. 3  is an explanatory view of a leakage reduction principle of the neckband-type wireless sound transducer of  FIG. 1 . 
     The third and fourth speakers  7   c  and  7   d  are arranged symmetrically with respect to the center O of the main body part  100 , the third speaker  9   c  for reduction being disposed on the extension line between the fourth speaker  7   d  and the center O, the fourth speaker  9   d  for reduction being disposed on the extension line between the third speaker  7   c  and the center O. The interval between the third speaker  7   c  and the fourth speaker  9   d  for reduction is a distance dc, while the interval between the fourth speaker  7   d  and the third speaker  9   c  for reduction is a distance dd. 
     The sound emitted by the third speaker  7   c  reaches the fourth speaker  9   d  for reduction after a delay time (dc/c: c is a sound speed). The controller  20  stores the delay time proportional to the distance dc, starts to apply an electric signal to the third speaker  7   c , then generates an electric signal for leakage reduction, which is opposite in phase to the electric signal applied to the third speaker  7   c , applies the electric signal for leakage reduction to the fourth speaker  9   d  for reduction after the delay time, and allows the fourth speaker  9   d  for reduction to emit the sound for leakage reduction to the outside of the main body part  100 , such that the sound emitted by the third speaker  7   c  is offset by the sound for leakage reduction that is emitted by the fourth speaker  9   d  for reduction, on the outside of the main body part  100 , that is, in an outward direction from the fourth speaker  9   d  for reduction. This sound offsetting operation considerably reduces the volume level of the sound from the third speaker  7   c  on the outside of the main body part  100 . 
     With the same principle, the sound emitted by the fourth speaker  7   d  is offset on the outside of the main body part  100  by the sound for leakage reduction that is emitted by the third speaker  9   c  for reduction. This principle equally applies to the sound of the first and second speakers  7   a  and  7   b  and to the sound of the fifth and sixth speakers  7   e  and  7   f.    
     While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood by those skilled in the art that the invention is not limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.