Patent Publication Number: US-2016227327-A1

Title: Speaker Box

Description:
FIELD OF THE INVENTION 
     The utility model relates to the field of speakers converting the electric signal into the sound wave, and especially to a speaker box with balanced vibration. 
     DESCRIPTION OF RELATED ART 
     With the advent of the era of mobile Internet, the number of smart mobile devices continues to rise. Among a plurality of mobile devices, mobile phone is undoubtedly the most common and the most portable mobile terminal equipment. Currently, the mobile phone has especially lots of functions one of which is high-quality music function, whereas the speaker in the mobile phone is one of necessary conditions for realizing this high-quality music function. Most mobile phones in the current market generally use the micro electromagnetic speaker to realize the music playing function. 
     Generally, the speaker includes a basket forming a housing, a magnetic circuit system fixed in the basket, and a vibration system interacting with the magnetic circuit system and generating the vibration. The magnetic circuit system typically includes a magnetic bowl, a magnet fixed at the central position of the magnetic bowl, and a magnetic gap formed between the magnetic bowl and the magnetic steel; and the vibration system often includes a voice coil partially extended into the magnetic gap and a diaphragm connected with the voice coil. 
     When the electric signal containing audio signal is introduced into the voice coil, the voice coil will interact with the magnetic field of the magnetic circuit system to generate Ampere Force and stress the Ampere Force; and the voice coil realizes reciprocating vibration to drive the diaphragm to vibrate, thus generating the acoustic radiation. 
     As the development of intelligence degree of the mobile phone, there are more and more media content in the mobile phone, users also improve the requirements on media content and sound quality and hope the sound generator in the mobile phone can provide excellent low-frequency response, this requires the sound generator to have a large rear cavity and brings a structure where the cavity is used to enclose the sound generator body therein, and this structure is generally referred to as a speaker box. 
     The speaker box generally needs a sound output hole to output the sound radiated by the sound generator body to the outside, generally speaking, the position of the sound output hole in the speaker box is bias relative to the sound generator body, that is, the position of the sound output hole is deflected relative to the center of the sound generator body, which causes the vibration system of the sound generator body to be located at the near end close to the sound output hole and the far end away from the sound output hole; when the vibration system vibrates, the air close to the near end of the vibration system is easy to pass the sound output hole but the air at the far end is hard to pass the sound output hole, this situation can be simply understood as that the near end close to the sound output hole is easy to vibrate but the far end is relatively hard to vibrate, and this unbalances the vibration on the near end and the far end of the vibration system and further causes a series of problems such as the distortion. 
     Therefore, it is necessary to provide a new speaker box to solve the problems mentioned above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the embodiment can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an isometric view of a speaker box in accordance with an exemplary embodiment of the present disclosure. 
         FIG. 2  is an exploded view of the speaker box in  FIG. 1 . 
         FIG. 3  is a broken view of the speaker box in  FIG. 1 . 
         FIG. 4  is a cross-sectional view of the speaker box in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT 
     The present invention will hereinafter be described in detail with reference to an exemplary embodiment. It should be understood the specific embodiments described hereby is only to explain this disclosure, not intended to limit this disclosure. 
     Referring to  FIGS. 1-4 , a speaker box  10  in accordance with an exemplary embodiment of the present disclosure, includes a shell  1  having a receiving space  20  and a sound generator  13  received in the shell  1 . The shell  1  includes an upper shell  11 , and a lower shell  12  engaging with the upper shell  11  for forming the receiving space  20 . The upper shell  11  is provided with a sidewall  110 . The sidewall  110  is provided with a sound output hole  111  communicating with the receiving space  20  and used for outputting the sound generated by the sound generator  13  out of the speaker box  10 . The sound generator  13  is connected to an external circuit by a conductive element  14 . In this embodiment, the conductive element  14  is a flexible circuit board. In order to conveniently connect the conductive element  14  to the outside, the lower shell  12  is provided with a gap  121 , and the conductive element  14  is then connected to the outside through the gap  121 . 
     The sound generator  13  further includes a magnetic circuit system and a vibration system interacting with the magnetic circuit system. The magnetic circuit system includes a lower plate  131 , a primary magnet  132  fixed at a central position of the lower plate  131 , a secondary magnet  133  fixed on the lower plate  131  and interlaced with the primary magnet  132 , and a magnetic gap accordingly formed between the primary magnet  132  and the secondary magnet  133 . The vibration system includes a voice coil  134  located in the magnetic gap and a diaphragm  130  for vibration and sound generation; and the diaphragm  130  further includes a dome part  135  located at the central position and a suspension  136  surrounding and supporting the dome part  135 . 
     On the basis of the sound output hole  111 , the magnetic circuit system is divided into a near end close to the sound output hole  111  and a far end away from the sound output hole  111 . In this embodiment, the secondary magnet  133  includes a first secondary magnet  133   a  and a second secondary magnet  133   b  located on two ends of the primary magnet  132 ; the first secondary magnet  133   a  is located on the near end of the magnetic circuit system; and the second secondary magnet  133   b  is located on the far end of the magnetic circuit system. 
     In the vibration process of the diaphragm  130 , the resistance to the part of the diaphragm  130  corresponding to the far end of the magnetic circuit system is greater than the resistance of the diaphragm  130  corresponding to the near end of the magnetic circuit system, which unbalances the vibration. The magnetic field strength of the far end of the magnetic circuit system is configured be greater than the magnetic field strength of the near end of the magnetic circuit system, therefore, the part of the diaphragm  130  corresponding to the far end of the magnetic circuit system is stressed with less driving power than the part of the diaphragm  130  corresponding to the near end of the magnetic circuit system and is easily to vibrate, thus reducing the sound resistance of the part of the diaphragm  130  corresponding to the far end, and balancing the vibration of the diaphragm, and reducing the distortion. 
     In order to realize the situation where the magnetic field strength of the far end is greater than the magnetic field strength of the near end, the volume of the second secondary magnet  133   b  can be configured be greater than the volume of the first secondary magnet  133   a;  the materials of the first secondary magnet  133   a  and the second secondary magnet  133   b  can be different, wherein the magnetic power of the material of the second secondary magnet  133   b  is greater than the magnetic power of the material of the first secondary magnet  133   a;  besides, the volume of the part of the primary magnet  132  close to the first secondary magnet  133   s  may be set to be less than the volume of the part of the primary magnet  132  close to the second secondary magnet  133   b,  of course, the magnetic power of the material of part of the primary magnet  132  close to the first secondary magnet  133   a  can be set to be less than the magnetic power of the material of the part of the primary magnet  132  close to the second secondary magnet  133   b,  that is, the primary magnet  132  can be made of two different materials, the magnetic power of the material of part of the primary magnet  132  close to the first secondary magnet  133   a  can be less than the magnetic power of the material of the part of the primary magnet  132  close to the second secondary magnet  133   b.    
     Further, in this embodiment, the secondary magnet is divided into two split ones, actually, the secondary magnet can also be a single body, in this condition, the part of the secondary magnet located on one end of the primary magnet is the first secondary magnet, and the part of the secondary magnet located on the other end of the primary magnet is the second secondary magnet. Furthermore, the magnetic circuit system in this embodiment includes the primary magnet and the secondary magnet, actually, in the condition only having the primary magnet, the technical solution provided in the utility model is still applicable, that is, the circumference of the primary magnet can be provided with a magnetic conductor that is at least partially surrounding the primary magnet, and different effect of magnetic field strength can also be realized by setting the magnetic power of the parts of the primary magnet close to or away from the sound output hole (different materials or different volumes as described above). 
     It is to be understood, however, that even though numerous characteristics and advantages of the present embodiment have been set forth in the foregoing description, together with details of the structures and functions of the embodiment, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.