Abstract:
A vibrator of the present invention comprises a coreless coil ( 2 ), a driver ( 4 ) including a magnet ( 4   a ) inserted in the coreless coil ( 2 ), a yoke ( 4   b ) for pinching the coreless coil ( 2 ) and facing the magnet ( 4   a ), and a top plate ( 4   c ), suspensions ( 6  and  8 ) for carrying resiliently the driver ( 4 ). The driver ( 4 ) is reciprocated in an axial direction of the coreless coil ( 2 ) by applying an alternate current to the coreless coil ( 2 ) to generate vibrations. The vibrator can be miniaturized without increasing a cost and has a good rising of vibrations.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a vibrator used for a notification of arrival in a mobile phone or the like and a method for manufacturing the same.  
         DESCRIPTION OF THE PRIOR ART  
         [0002]    Conventionally, many vibrators for a notification of arrival used in a mobile phone have been configured to generate vibrations by a motor rotating a weight (for example, see Japanese Patent Laid-Open Nos. H7-107699 and H 6-205565).  
           [0003]    Generally, a light and compact vibrator is required to use in a mobile device such as the mobile phone. A competition in miniaturization of the motor has been carried out in the conventional vibrator. However, there is a problem that a commutator, a brush and so on are required for the motor and a special processing and any material are required to miniaturize the entire vibrator and therefore it costs much. Consequently, it is intended that the vibrator is miniaturized without increasing the cost.  
           [0004]    Moreover, in the conventional vibrator in which the weight is rotated by the motor, sufficient vibrations cannot be obtained until the rotation of the motor is raised sufficiently. In this way, if it takes a long time for the raising of vibrations, in case of generating vibrations in response to a music for informing a user of arrival, there is generated a time lug without the vibrations being synchronized with the music.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention has been made to resolve the aforementioned problems in the prior art and it is therefore an object of the present invention to provide a vibrator, which can be miniaturized without an increment of cost and has a good rising of vibrations and a method for manufacturing the same.  
           [0006]    To attain the above object, the vibrator comprises: a coreless coil; a driver including a magnet inserted in the coreless coil, a yoke for sandwiching the coreless coil and opposing the magnet and a top plate; a suspension for carrying resiliently the driver.  
           [0007]    An alternate current is supplied to the coreless coil to generate vibrations by reciprocation of the driver in an axial direction of the coreless coil.  
           [0008]    In addition, a method for manufacturing a vibrator, according to the present invention comprises: a process for mounting coreless coils on a collective base plate capable of taking out a plurality of bases; a process for overlapping and mounting a first collective spacer plate on the collective base plate; a process for overlapping and mounting a first collective suspension plate on the first collective spacer plate; a process for overlapping and mounting a collective frame plate on the first collective suspension plate; a process for containing drivers in the collective frame plate and for supporting them by the first collective suspension plate; a process for overlapping and mounting a second collective suspension plate on the collective frame plate; a process for overlapping and mounting a second collective spacer plate on the second collective suspension plate; a process for overlapping and mounting a collective protector plate on the second collective suspension plate; and a process for cutting the collective base, first collective spacer, first collective suspension, collective frame, second collective suspension, second collective spacer and collective protector plates, which are overlapped and separating into an individual vibrator. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is an exploded perspective view showing a structure of a vibrator according to the present invention.  
         [0010]    [0010]FIG. 2 is a perspective view showing the vibrator shown in FIG. 1 in an assembled state.  
         [0011]    [0011]FIG. 3 is an exploded perspective view showing a structure of a driver in the vibrator.  
         [0012]    [0012]FIG. 4 is a perspective view showing a state of manufacturing the vibrator shown in FIG. 1. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0013]    An embodiment of the present invention will be explained with reference to the accompanying drawings below.  
         [0014]    A vibrator according to the present invention comprises a coreless coil  2 , a driver  4  and suspensions  6  and  8 .  
         [0015]    The coreless coil  2  is composed of a cylindrical bobbin  2   a  and a coil wound peripherally of the bobbin  2   a  and is disposed in a central portion of the vibrator.  
         [0016]    The driver  4  in the embodiment is composed of a columnar magnet  4   a , a yoke  4   b  attached on one end surface of the magnet  4   a , a top plate  4   c  attached on the other end surface of the magnet  4   a , and weights  4   d  attached to the yoke  4   b , as shown in FIG. 3.  
         [0017]    The yoke  4   b  has a plate-like portion  4   e  attached on the one end surface of the magnet  4   a , opposite side wall portions  4   f  projecting from the plate-like portion  4   e  and disposed with a predetermined distance from both side surfaces of the magnet  4   a , and weight mounting portions  4   g  comprising protrusions provided on outer surfaces of the side wall portions  4   f  and configured to support the weights  4   d  from directions of reciprocating (upward and downward directions in FIGS. 1 and 3).  
         [0018]    The driver  4  is disposed in such a manner that the magnet  4   a  is inserted in the coreless coil  2  and the side surfaces of the magnet  4   a  and the side wall portions  4   f  of the yoke  4   b  are disposed so as to face with respect to each other while sandwiching the coreless coil therebetween.  
         [0019]    The suspensions  6  and  8  are composed of a pair of suspension members or plate springs  6 A,  6 B,  8 A and  8 B, respectively. The plate springs  6 A,  6 B,  8 A and  8 B each has at outer ends thereof opposite fixed ends  6   a  and  8   a  fixed to a case which will be explained and at inner ends thereof opposite opened ends  6   b  and  8   b  engaged with or mounted on the yoke  4   b  of the driver  4 . The suspensions  6  and  8  are configured in such a manner that the plate springs  6 A,  6 B,  8 A and  8 B are disposed in axisymmetrical positions of a movement direction of the driver  4  or an axis  2   c  of the coreless coil  2 , and support resiliently the driver  4 .  
         [0020]    In the embodiment, the coreless coil  2 , driver  4  and suspensions  6  and  8  are contained in the case  10  in order to unitize the vibrator and be easy to handle it. The case  10  is composed of a base  12 , a frame  14 , spacers  16  and  18 , and a protector  20 , as shown in FIG. 2.  
         [0021]    As shown in FIG. 1, the coreless coil  2  is attached on a central portion of the base  12  in such a manner that the axis  2   c  of the coreless coil  2  becomes perpendicular to a surface of the base  12 . The frame  14  is made of a synthetic resin and is adapted to contain therein the driver  4 . The frame  14  has opposite openings  14   a  and  14   b  at forward and backward sides in a direction of movement (upward and downward directions in the drawing) of the driver  4 , and fixed ends  8   a  and  6   a  of the suspensions  8  and  6  are fixed on edges of the openings  14   a  and  14   b . In the embodiment, when the spacers  18  and  16  are attached on the edges of the openings  14   a  and  14   b  of the frame  14 , respectively, the fixed ends  8   a  and  6   a  of the suspensions  8  and  6  are sandwiched and fixed between the frame  14  and spacers  18  and  16 . The spacers  16  and  18  in the embodiment comprise ringlike bodies of a similar rectangular shape to the planar shape of the frame  14 .  
         [0022]    The lower opening  14   b  of the frame  14 , in FIG. 1, is closed by means of the base  12  being mounted through the spacer  16  on the frame  14 , and the upper opening  14   a  of the frame  14 , in FIG. 1, is closed by means of the plate-like protector  20  being mounted through the spacer  18  on the frame  14 .  
         [0023]    In the vibrator having the above structure, the synchronous frequency of the driver  4  supported by the suspensions  6  and  8  is set to be 150 Hz and an alternate current is applied to the coreless coil  2 .  
         [0024]    In the vibrator, a magnetic flux is concentrated into gaps formed between the magnet  4   a  and the side wall portions  4   f  of the yoke  4   b , and the driver  4  is reciprocated along the axis  2   c  by a magnetic field and a direction thereof generated by electrifying to the coreless coil  2  inserted between the side wall portions  4   f . At this time, vibrations are generated in the vibrator to cause a mobile phone or the like, in which the vibrator is mounted, to vibrate.  
         [0025]    In this way, because the vibrator structured as described generates the vibrations by reciprocating the driver  4  supported resiliently by means of the suspensions  6  and  8 , by application of the alternate current to the coreless coil  2 , the rising of the vibration is superior, differing from converting the rotation of the motor to the vibrations in the prior art.  
         [0026]    In addition, in the embodiment, each of the components of the case  10  are formed into an approximately plate-like shape and the plate springs are used in the suspensions  6  and  8  in order to be easy to manufacture the vibrator by a method for manufacturing, which will be described hereinafter. The suspensions  6  and  8 , base  12  and protector  20  may be also mounted on the frame  14  by omitting the spacers  16  and  18  and each of the suspensions  6  and  8  may be formed of a coil spring, a rubber and a resin having an elasticity, and so on.  
         [0027]    Although the case  10  is also set in a planar rectangular shape extending in a direction crossing to the axis  2   c  in order to secure a stroke of the suspensions  6  and  8 , otherwise it is possible to set a square, circle and so on so as to comply with the planar shape of the case and so on.  
         [0028]    The method for manufacturing the vibrator as shown in FIG. 1 will be explained in connection with FIG. 4. The manufacturing method is configured to be capable of manufacturing correctively a plurality of vibrators.  
         [0029]    More specifically, there are used a collective base plate  22 , a collective spacer plate or first collective spacer plate  24 , a collective suspension plate or first collective suspension plate  26 , a collective frame plate  28 , a collective suspension plate or second collective suspension plate  30 , a collective spacer plate or second collective spacer plate  32  and a collective protector plate  34 , which are capable of taking out a plurality of bases  12 , spacers  16 , suspensions  6 , frames  14 , suspensions  8 , spacers  18  and protectors  20 , respectively, as sown in FIG. 1.  
         [0030]    Each of the coreless coils  2  is, first, mounted on the corresponding portion to each of the bases  12  in the collective base plate  22 . In addition, the collective base plate  22  is pre-formed with through-holes, a conductive pattern and so on, as needed, and coil terminals of each of the coreless coils  2  are connected with the conductive pattern by soldering or the like.  
         [0031]    The collective spacer plate  24 , first collective suspension plate  26  and collective frame plate  28  are overlapped in turn on the collective base plate  22 . These plates are adhered through adhesive layers formed on both or one of mutual contacting surfaces by printing or the like, or adhesive sheets disposed therebetween. When the plates are overlapped, the corresponding portions of the spacer  16 , suspension  6  and frame  14  in each vibrator are overlapped to match, respectively.  
         [0032]    Here, each of the drivers  4  is contained in each of the frames  14  in the collective frame plate  28  and each driver  4  is supported on each of the suspensions  6  in the first collective suspension plate  26 . In addition, thereafter, by the second collective suspension plate  30  being mounted, the driver  4  is sandwiched by and supported on the suspensions  6  and  8  in the first and second collective suspension plates  26  and  30 .  
         [0033]    Thereafter, the second collective suspension, collective spacer and collective protector plates  30 ,  32  and  34  are overlapped in turn on the collective frame plate  28 . At this time, similarly, these plates are adhered through adhering layers formed on both or one of mutual contacting surfaces by printing or the like, or adhering sheets disposed therebetween. Also, the corresponding portions of the suspension  8 , spacer  18  and protector  20  in each vibrator are overlapped to match, respectively.  
         [0034]    As described above, after the collective plates are overlapped in turn and adhered, the plates are cut a dicer and separated into individual vibrators.  
         [0035]    Thereby, a great number of vibrators can be manufactured at a time.  
         [0036]    According to the present invention, a good rising of vibrations can be expected, because the vibrations are generated by reciprocation of the driver without converting the rotation of the motor or the like to the vibrations.  
         [0037]    Therefore, it is possible to generate or stop the vibrations in response to a melody and so on, informing a user of arrival in a mobile phone or the like.  
         [0038]    The present invention makes also it possible to provide a simple structure, a compact and thinned vibrator, because the plate-like suspensions, the driver having a simple structure and the coreless coil are contained in the case comprising a combination of the plate-like base, protector and frame, and therefore they are unitized.  
         [0039]    Moreover, the present invention makes it possible to carry out a mass-production of the vibrator, a superior workability due to simple processes in the manufacture of vibrator and to promote the reduction of cost, because the many parts of the vibrator are configured to be capable of taking out and then the collected parts can be manufactured by overlapping them in turn.