Abstract:
Disclosed herein is a linear vibration device including: a stator assembly including a plate and a case; and a vibrator assembly including a yoke and a spring, wherein the case of the stator

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2011-0077882, filed on Aug. 4, 2011, entitled “Linear Vibration Device”, which is hereby incorporated by reference in its entirety into this application. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to a linear vibration device. 
         [0004]    2. Description of the Related Art 
         [0005]    Various types of vibration generation devices have been mounted in portable electronic devices such as a portable phone, a game machine, a portable information terminal, and the like, in order to prevent inconvenience to other people due to an external sound. 
         [0006]    In these vibration generation devices, a low cost automation design needs to be performed from a design step in order to implement low cost automation and reduce the number of workers in a manufacturing method. 
         [0007]    A process of welding a case (or a bracket) and a spring to each other, which is one of core processes in a manufacturing method, is an obstacle in the LCA design. In the case in which this problem will be solved, it is possible to reduce the number of workers needed to manufacture the vibration generation device. In the case in which the number of workers is reduced, a product may be manufactured at the lowest cost. 
         [0008]    The linear vibration device according to the prior art is configured to include a spring member, a weight body, a bracket, and the like, and uses a scheme of welding a spring assembly inwardly of a case in a case assembly and then bonding-assembling a vibrator and a coil raw material thereto. Since this scheme is a scheme of manufacturing a moving assembly by directly assembling a raw material to an assembly, it has a difficulty in implementing low cost automation and reducing the number of workers. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention has been made in an effort to provide a linear vibration device capable of automating a manufacturing process thereof and reducing the number of workers in the manufacturing process. 
         [0010]    According to a preferred embodiment of the present invention, there is provided a linear vibration device including: a stator assembly including a plate and a case; and a vibrator assembly including a yoke and a spring, wherein the case of the stator assembly and the spring of the vibrator assembly are coupled to each other. 
         [0011]    The case may be provided with a protrusion, the spring may be provided with a groove, and the protrusion and the groove may be coupled to each other. 
         [0012]    After the protrusion of the case and the groove of the spring are coupled to each other, they may be welded to each other. 
         [0013]    After the protrusion and the groove are fitted into each other, the spring may rotate, such that a position to be welded is positioned at a central portion of the protrusion. 
         [0014]    After the case and the spring are assembled to each other, the welding may be performed from an outer side portion of the case while a position of the spring is confirmed through the groove. 
         [0015]    The welding may be laser welding. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a partial cross-sectional view of a linear vibration device according to a preferred embodiment of the present invention; 
           [0017]      FIG. 2  is an exploded perspective view of a linear vibration device according to a preferred embodiment of the present invention; 
           [0018]      FIG. 3  is an assembly perspective view of a linear vibration device according to a preferred embodiment of the present invention; and 
           [0019]      FIG. 4  is an assembly perspective view of a linear vibration device according to a preferred embodiment of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    Various objects, advantages and features of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings. 
         [0021]    The terms and words used in the present specification and claims should not be interpreted as being limited to typical meanings or dictionary definitions, but should be interpreted as having meanings and concepts relevant to the technical scope of the present invention based on the rule according to which an inventor can appropriately define the concept of the term to describe most appropriately the best method he or she knows for carrying out the invention. 
         [0022]    The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings. In the specification, in adding reference numerals to components throughout the drawings, it is to be noted that like reference numerals designate like components even though components are shown in different drawings. Further, when it is determined that the detailed description of the known art related to the present invention may obscure the gist of the present invention, the detailed description thereof will be omitted. 
         [0023]    Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
         [0024]      FIG. 1  is a partial cross-sectional view of a linear vibration device according to a preferred embodiment of the present invention.  FIG. 2  is an exploded perspective view of a linear vibration device according to a preferred embodiment of the present invention.  FIG. 3  is an assembly perspective view of a linear vibration device according to a preferred embodiment of the present invention.  FIG. 4  is an assembly perspective view of a linear vibration device according to a preferred embodiment of the present invention. 
         [0025]      FIG. 1  shows a partial cross-sectional view of a linear vibration device  100 . The linear vibration device  100  is configured to include a bracket  111 , a first damping Poron  112 , a first magnet  113 , a plate  121 , a second magnet  122 , a second damping Poron  123 , a case  124 , a yoke  131 , a spring  132 , a flexible printed circuit (FPC)  133 , a vibrator  134 , and a coil  135 . 
         [0026]    The bracket  111  serves to enclose and protect the linear vibration device  100  from the outside and is generally made of an iron based material. 
         [0027]    The first damping Poron  112  is attached to an upper inner surface of the bracket  111  to thereby prevent friction or abrasion of a vibration part with the bracket  111 . 
         [0028]    The first magnet  113  is attached to the upper inner surface of the bracket  111  and generates magnetic force. 
         [0029]    The plate  121  is formed to be spaced apart from the first magnet  113  by a predetermined interval, and the first magnet  113  and the plate  121  include a magnetic fluid applied therebetween. 
         [0030]    The second magnet  122  is attached to a lower portion of the plate  121  and generates magnetic force. 
         [0031]    The second damping Poron  123  is attached to a lower surface of the case  124  to thereby prevent friction or abrasion of the case  124  with other components. 
         [0032]    The case  124  generally supports the linear vibration device  100  at a lower portion thereof and is connected to the bracket  111  provided at an upper portion thereof to thereby form an inner space of the linear vibration device  100 . 
         [0033]    The plate  121 , the second magnet  122 , the second damping Poron  123 , and the case  124  configures one assembly, which is called a stator assembly  120 . The stator assembly  120  is entirely assembled and then assembled to another assembly. 
         [0034]    The yoke  131  is provided between the vibrator  134  and the coil  135 , which are a vibration part, to thereby support vibration of a vibration member. 
         [0035]    The spring  132  supports the yoke  131  and the coil  135 , is provided at the lower portion, and is generally a leaf spring. The spring  132  has a lower distal end fixed to a lower edge of the case  124 . 
         [0036]    The FPC  133  is provided at an upper portion of the vibrator  134  and includes an electrical circuit and an element mounted thereon to thereby apply an electrical signal. 
         [0037]    The vibrator  134  is mounted in the linear vibration device  100  and is connected to the yoke  131  and the coil  135  to thereby vibrate vertically. 
         [0038]    The coil  135  is attached to the yoke  131  and is formed to face the first and second magnets  113  and  122 , such that the vibration part vibrates by magnetic force generated by the coil  135  and the first and second magnets  113  and  122 . 
         [0039]    The yoke  131 , the spring  132 , the FPC  133 , the vibrator  134 , and the coil  135  configures one assembly, which is called a vibrator assembly  130  The vibrator assembly  130  is assembled to the stator assembly  120 . 
         [0040]    The stator assembly  120  and the vibrator assembly  130  are formed in order to implement low cost automation and reduce the number of workers in an assembling process. The case  124  of the stator assembly  120  and the spring  132  of the vibrator assembly  130  are simply assembled and coupled to each other, such that the entire linear vibration device  100  may be easily manufactured. 
         [0041]    A scheme of directly assembling the stator assembly  120  and the vibrator assembly  130  to each other as described above may further approach the low cost automation without performing a process of placing a raw material on an assembly. 
         [0042]      FIG. 2  is a view simply showing a form in which the stator assembly  120  and the vibrator assembly  130  are assembled to each other. When the stator assembly  120  and the vibrator assembly  130  are assembled to each other, a groove  136  of the vibrator assembly  130  is assembled to a protrusion  125  of the stator assembly  120 . 
         [0043]      FIG. 3 , which is a view showing a form after the stator assembly  120  and the vibrator assembly  130  are assembled to each other, shows that after the stator assembly  120  and the vibrator assembly  130  are assembled to each other and the protrusion  125  and the groove  136  are fitted into each other, and the spring rotates, such that a position to be welded is positioned to a central portion of the protrusion. The welding may be laser welding. 
         [0044]      FIG. 4 , which is a view showing a form after the stator assembly  120  and the vibrator assembly  130  are assembled to each other from an outer side, shows that after the stator assembly  120  and the vibrator assembly  130  are assembled to each other, the stator assembly  120  and the vibrator assembly  130  are welded to each other from an outer side portion of the stator assembly  120  while a position of the vibrator assembly  130  is confirmed through the groove  136 . 
         [0045]    Since the welding is performed from the outer side portion while the position of the vibrator assembly  130  is confirmed, it is possible to implement the low cost automation and reduce the number of workers in a process of assembling the stator assembly  120  and the vibrator assembly  130  to each other. 
         [0046]    Therefore, a manufacturing time may be reduced, and labor costs may be reduced. As set forth above, with the linear vibration device according to the preferred embodiment of the present invention, after the stator assembly and the vibrator assembly are assembled to each other, the stator assembly and the vibrator assembly are welded to each other from the outer side portion of the stator assembly while the position of the vibrator assembly is confirmed through the groove. 
         [0047]    Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, they are for specifically explaining the present invention and thus a linear vibration device according to the present invention are not limited thereto, but those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 
         [0048]    Accordingly, such modifications, additions and substitutions should also be understood to fall within the scope of the present invention.