Patent Publication Number: US-9906868-B2

Title: Miniature speaker

Description:
FIELD OF THE INVENTION 
     The invention is related to electro-acoustic transducers, more particularly to a miniature speaker used in a portable consumer device. 
     DESCRIPTION OF RELATED ART 
     With the coming of mobile internet times, the quantity of intelligent mobile device is rising continuously. Among many mobile equipment, mobile phone is the most common and portable mobile terminal equipment. At present, the function of mobile phone is diversified. One of important functions is that of high quality music, and the miniature speaker in mobile phone is one of the essential conditions of realizing the function of high quality music. 
     The existing miniature speaker generally includes a housing, a vibration system and a magnetic circuit system. The housing fixes the vibration system and the magnetic circuit systems. The vibration system includes a diaphragm and a voice coil driving the diaphragm to sound. The magnetic circuit system includes two main magnets with the same magnetic poles thereof facing to each other. Two main magnets are welded and connected through glue or laser spot welding. However, the two main magnets are easy to be detached from each other due to the repulsion force between the two magnets, which badly affects the reliability of the miniature speaker. 
     Therefore, it is necessary to provide an improved miniature speaker to overcome above disadvantage. 
    
    
     
       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 and exploded view of a miniature speaker in accordance with an exemplary embodiment of the present disclosure. 
         FIG. 2  is an assembled view of the miniature speaker in  FIG. 1 . 
         FIG. 3  is a cross-sectional view of the miniature speaker taken along line A-A in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT 
     The present invention will hereinafter be described in detail with reference to an exemplary embodiment. To make the technical problems to be solved, technical solutions and beneficial effects of the present disclosure more apparent, the present disclosure is described in further detail together with the figures and the embodiment. It should be understood the specific embodiment described hereby is only to explain this disclosure, not intended to limit this disclosure. 
     Referring to  FIGS. 1-3 , a miniature speaker  100  in accordance with an exemplary embodiment of the present disclosure includes a frame  1 , a vibration system  3  and a magnetic circuit system  5  fixed and connected on the frame  1 , a cover plate  6  arranged on the vibration system  3  and covering the vibration system, a gasket  7  located between the vibration system  3  and the cover plate  6 , and a sound hole  9  formed in the cover plate  6 . 
     The frame  1  includes a hollow rectangular case  11  and a step part  13  extending from four corners of the rectangular case  11  toward the magnetic circuit system  5 . The step part  13  is located on the lower side of the rectangular case  11  and abuts against the magnetic circuit system  5 . 
     The vibration system  3  includes a diaphragm  31  and a voice coil  33  driving the vibration of the diaphragm  31 . The diaphragm  31  includes a first fixation part  311  located on the middle position of the diaphragm  31 , a second fixation part  313  located on the edge position of the diaphragm  31  and a vibration part  315  connected between the first fixation part  311  and the second fixation part  313 . The first fixation part  311  is connected with the magnetic circuit system  5 . The second fixation part  313  is connected with the rectangular case  11  fixedly and is clamped and set between the rectangular case  11  and the cover plate  6 . 
     The vibration part  315  includes a main vibration body  3151 , the a suspension  3153  extending from the inner edge of the main vibration body  3151  and is connected with the first fixation part  311 , a second suspension  3155  extending from the outer edge of the main vibration body  3151  and is connected with the second fixation part  313 . The main vibration body  3151  is connected with the voice coil  33 . The first suspension  3153  is raised on the direction away from the magnetic circuit system  5 . The second suspension  3155  is raised on the direction closed to the magnetic circuit system  5 , namely the two raised directions are opposite. 
     Optionally, the diaphragm  31  further includes a dome  317 . The dome  317  is attached on an upper surface or lower surface of the main vibration body  3151 . In this embodiment, the dome  317  is circular hollow structure which is located on the lower surface of the main vibration body  3151  closed to the magnetic circuit system  5 . The voice coil  33  is connected with the dome  317  fixedly. 
     The magnetic circuit system  5  includes a lower plate  51 , a magnet part  53  set on the lower plate  51  to drive the voice coil  33 , auxiliary magnets  55  set around the magnet part  53  and auxiliary pole plates  57  attached on the auxiliary magnets  55 . 
     The magnet part  53  includes a first magnet  531 , and a second magnet  533  set on the first magnet  531  and a pole plate  535  sandwiched between the first magnet  531  and the second magnet  533 . The first magnet  531  and the second magnet  533  are such configured that a magnetic pole of the first magnet faces the same magnetic pole of the second magnet. It can be set in N-S-S-N way and S-N-N S way as well. The magnet part  53  is disposed on the lower part of the first fixation part  311  and the first fixation part  311  is connected with the magnet part  53  fixedly. Specifically, the first fixation part  311  is attached on the surface of the second magnet  533 . 
     The auxiliary magnets  55  surrounds the magnet part  53  and forms a magnetic gap  56 A with the magnet part  53 . The voice coil  33  is suspended on the magnetic gap  56 A. In this embodiment, the quantity of the magnetic gap  55  is four. The quantity of the auxiliary pole plate  57  is four which are attached on the surface of the magnetic gap  55  facing to the diaphragm  31 . Specifically, four said magnetic gap  55  is located on the lower part of the rectangular case  11  set and clamped on the adjacent the step part  13  separately. Specifically, two magnetic gaps  55  are set symmetrically along the direction of the length of the rectangular case  11 . Two magnetic gaps  55  are set symmetrically along the width direction of the rectangular case  11 . 
     The cover plate  6  is covered and connected on the upper side of the diaphragm  31 . The cover includes a bottom wall  1  set oppositely to the lower plate  51  and a side wall  63  extending from the bottom wall  61  to the direction of the diaphragm  31 . The side wall  63  is covered and connected on the second fixation part  313 . 
     The gasket  7  is clamped and set between the bottom wall  61  and the first fixation part  313 . The gasket  7  is magnet. Preferably, the direction of magnetizing is the magnet is the same as the second magnet  533 . The space between the first fixation part  313  and said bottom wall is utilized effectively, and then the magnetic performance of the miniature speaker  100  is improved. 
     The bottom wall  61 , the gasket  7 , the first fixation part  311 , the second magnet  533 , the pole plate  535 , the first magnet  531  and the lower plate  51  are stacked layer by layer. The bottom wall  61  and the lower plate  51  press tightly the gasket  7 , the first fixation part  311  and the magnet part  53  between the bottom wall  61  and the lower plate  51 . 
     The miniature speaker  100  is the sounding speaker of the side wall. The sound hole  9  is set on the side wall  63  of the cover plate  6 . 
     The miniature speaker  100  provided by the present disclosure utilizes reasonably the space between the cover plate  6  and diaphragm  31 , and by adding gasket  7  between the bottom wall  61  of the cover plate  6  and the first fixation part  311  of the diaphragm  31 . The bottom wall  61  and the lower plate  51  press tightly the gasket  7 , the first fixation part  311  and the magnet part  53  between the bottom wall  61  and the lower plate  51  to fix the magnet part  53  firmly, therefore the reliability of assembling is improved. In addition, the gasket  7  can be a magnet which improves the magnetic performance further. 
     It is to be understood, however, that even though numerous characteristics and advantages of the present exemplary 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 where the appended claims are expressed.