Abstract:
A voice coil motor type focusing actuator, which includes a fixed unit, the fixed unit comprises a receiving chamber, a slide fitting channel, a first coil, and a magnet. A movable unit, the movable unit is received inside the receiving chamber of the fixed unit, having a first magnetic conducting flange being affected by the first coil and magnet of the fixed unit, a lens receiving means, a slide fitting rail, the movable unit is movable relative to the fixed unit to define an axial line.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to voice coil motor and more particularly, to a voice coil motor type focusing actuator. 
         [0003]    2. Description of the Related Art 
         [0004]    A conventional voice coil motor type focusing actuator essentially comprises a fixed unit and a movable unit movably mounted in the fixed unit. A coil and a magnet are mounted on the fixed unit and the movable unit respectively. 
         [0005]    Conventional voice coil motor type focusing actuators have the common drawback of complicated structure, resulting in a complicated installation procedure. Further, improper connection among parts causes instability of the structure. Further, these conventional voice coil motor type focusing actuators cannot provide a good magnetic effect. 
         [0006]    Therefore, it is desirable to provide a voice coil motor type focusing actuator that eliminates the aforesaid drawbacks. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide an actuator, which has the coil and magnet being mounted on the fixed unit or movable unit at the same time, for simplify the structure and evaluate the magnetic conducting effect. 
         [0008]    It is another object of the present invention to provide an actuator, which provides a magnetic conducting flange of the fixed unit and the movable unit, the magnetic conducting flange prompting the magnetic force and preventing intake of the article or dust. 
         [0009]    It is still another object of the present invention to provide an actuator, which the coil can be mounted on a bobbin, then simplified the assembly and lowering the cost. 
         [0010]    To achieve these and other objects of the present invention, the voice coil motor type focusing actuator comprises a fixed unit, the fixed unit comprises a receiving chamber, a slide fitting channel, a first coil, and a magnet. A movable unit, the movable unit is received inside the receiving chamber of the fixed unit, having a first magnetic conducting flange being affected by the first coil and magnet of the fixed unit, a lens receiving means, a slide fitting rail, the movable unit is movable relative to the fixed unit to define an axial line. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective view of an actuator according to the present invention. 
           [0012]      FIG. 2  is another perspective view of an actuator according to the present invention. 
           [0013]      FIG. 3  is a partial exploded view of the actuator of  FIG. 2 . 
           [0014]      FIG. 4  is another direction exploded view of the actuator of  FIG. 3 . 
           [0015]      FIG. 5  is a partial exploded view of the actuator of  FIG. 3 . 
           [0016]      FIG. 6  is another partial exploded view of the actuator of  FIG. 3 . 
           [0017]      FIG. 7  is a sectional view taken along line  7 - 7  of  FIG. 1 . 
           [0018]      FIG. 8  is a sectional view taken along line  8 - 8  of  FIG. 1 , showing the movable unit positioned to a first position. 
           [0019]      FIG. 9  is similar to  FIG. 8 , but showing the movable unit positioned to a second position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    Referring to  FIGS. 1-7 , a voice coil motor type focusing actuator in accordance with a preferred embodiment of the present invention is shown comprising a first cover  10 , a first bracket  20 , a second bracket  30 , four magnets M 1 , a bobbin  40 , a first coil C 1 , a second coil C 2 , a holder conductor  50 , a lens holder  60  and a second cover  70 . 
         [0021]    The first cover  10  comprises a bottom panel  11 , an escape hole  12  cut through the center of the bottom panel  11 , two coupling legs  13 , two locating sockets  131  each formed on the coupling legs  13  respectively, two opposite first conjunction legs  14  and  15  perpendicularly extend from two opposite peripheral corners of the bottom panel  11 , each of the first conjunction legs  14  and  15  forms a wire receiving slot  141  and  151 , and two electric conducting pins  17 . 
         [0022]    The first bracket  20  and the second bracket  30  each comprises a frame body  21  and  31 , an accommodation receiving chamber  22  and  32  defined in the frame body  21  and  31 , a first magnetic conducting flange  23  and a second magnetic conducting flange  33  formed of a slop surface opposite outwardly, a first stop edge  26  and a second stop edge  36  defined at an end of the first and second magnetic conducting flanges  23  and  33  respectively. 
         [0023]    Wherein the first bracket  20  and the second bracket  30  can construct a bracket unit, and the bracket unit formed a receiving chamber inside. 
         [0024]    The bobbin  40  has a bobbin barrel  41  mounted between the first bracket  20  and the second bracket  30 , a receiving room  42 , two coil winding grooves  43  and  44 , four magnet mounting slots  45 , and two slide fitting channels  47 . 
         [0025]    The first coil C 1  and the second coil C 2  is wound on the coil winding groove  43  and  44  of the bobbin  40  at the sides corresponding to the magnets M 1 , the first coil C 1  and the second coil C 2  is conducted to the two electric conducting pins  17  respectively; The two coils C 1  and C 2  can construct a coil conduction unit. 
         [0026]    The magnets M 1  are respectively mounted in the magnet mounting slots  45  of the bobbin  40 . And let the N port of all magnets M 1  facing inwards and the S port facing outwards. On the other hand, still can let the N port of all magnets M 1  facing outwards and the S port facing inwards. 
         [0027]    Moreover, the bracket unit, the coil conduction unit and the magnets can construct a fixed unit. 
         [0028]    The holder conductor  50  is magnetic conductive and hollow inserted to the receiving room  42  of the bobbin  40 , the holder conductor  50  has a barrel body  51 , a first magnetic conducting flange  52  and a second magnetic conducting flange  53  outwardly expended at two distal ends and approximately paralleled to the first magnetic conducting flange  23  and the second magnetic conducting flange  33  respectively, two lockable slots  55 . 
         [0029]    The lens holder  60  comprises a holder shell  61  formed by plastic injection molding to wrap inside the holder conductor  50 , a first stop edge  62  and a second stop edge  63 , a lens receiving means, for example, a screw hole  65  formed in the holder shell  61  for receiving a lens (not shown), and two slide fitting rails  67  of rectilinear shape disposed on the outside wall thereof at two opposite sides and respectively coupled to the slide fitting channels  47  of the bobbin  40 . 
         [0030]    Wherein the holder conductor  50  and the lens holder  60  can construct a movable unit. 
         [0031]    The second cover  70  comprises a body  71  covered on the top side of the bracket  20 , an escape hole  72  corresponding to the screw hole  65  of the lens holder  60 , two locating holes  73  respectively fastened to the coupling legs  13  of the first cover  10 , two locating blocks  731  insertion with corresponding locating sockets  131 , two second conjunction legs  74  and  75  perpendicularly extend from the two opposite peripheral corners of the body  71  and supported by each of the first conjunction legs  14  and  15  of the first cover  10 . 
         [0032]    Further, the first cover  10  and the second cover  70  can constitute a carrier unit. 
         [0033]    As shown in  FIG. 8 , when electric current is connected to the first coil C 1  and the second coil C 2 , the first coil C 1  and the second coil C 2  are excited to act upon the magnets M 1 , thereby producing a magnetic force to move down the lens holder  60  with the slide fitting rails  67  along the two slide fitting channels  47  of the bobbin  40 , until the first stop edge  62  of the lens holder  60  stop against the first stop edge  26  of the first bracket  20 , the lens holder  60  then positioned at a first locating position. Wherein the magnetic force of the first coil C 1  and the second coil C 2  is larger than the magnets M 1 . 
         [0034]    On the contrary, as shown in  FIG. 9 , when the first coil C 1  and the second coil C 2  are conducted in a converse electric current, the first coil C 1  and the second coil C 2  are excited to act upon the magnets M 1 , thereby producing a magnetic force to move upon the lens holder  60  with the slide fitting rails  67  along the two slide fitting channels  47  of the bobbin  40 , until the second stop edge  63  of the lens holder  60  stop against the second stop edge  36  of the second bracket  30 , the lens holder  60  then positioned at a second locating position. 
         [0035]    When lens holder  60  positioned on the first locating position or the second locating position, the first coil C 1  and the second coil C 2  did not need to conduct current further; because the magnets M 1  is at the middle, the gap between the first magnetic conducting flange  23  of the first bracket  20  and the first magnetic conducting flange  52  of the holder conductor  50  is different from the gap between the second magnetic conducting flange  33  of the second bracket  30  and the second magnetic conducting flange  53  of the holder conductor  50  at the same time, the bigger the gap, where there the magnetic force from the magnets M 1  is smaller, the smaller the gap, where there the magnetic force from the magnets M 1  is larger, then achieve the magnets M 1  to control the lens holder  60  holding on the first locating position or second locating position. 
         [0036]    Moreover, the first magnetic conducting flange  23  of the first bracket  20  and the second magnetic conducting flange  33  of the second bracket  30  both formed of a hook section, the first and second magnetic conducting flanges  52  and  53  of the holder conductor  50  formed of a predetermine slope surface, then preventing intake of the article or dust. 
         [0037]    The actuator can imply hereafter. 
         [0038]    First, the actuator comprised only the first coil, but no the second coil. 
         [0039]    Second, the magnets, the first coil and the second coil can mount on the movable unit but not the fixed unit for different design. 
         [0040]    Further, there is no need of the bobbin, but the magnets, the first coil and the second coil are mounted on the bracket unit, that is the first bracket and the second bracket; and both of the magnets and the coils are mounted inside or outside the bracket unit, or one of the magnets and the coils inside and the other outside the bracket unit. 
         [0041]    And, there is no need of the first cover  10  and the second cover  70 , and the actuator can directly mounted to the camera or phone. 
         [0042]    Still further, the first and second magnetic conducting flanges of the fixed unit and the movable unit are formed of an arch flange relatively, and the first and second magnetic conducting flanges can be another shape which achieves the function of enhancing the magnetic conducting effect. 
         [0043]    As indicated above, the invention provides a voice coil motor type focusing actuator, which has the following benefits: 
         [0044]    1. The coil and the magnet are mounted on the fixed unit or movable unit at the same time, for simplify the structure and evaluate the magnetic conducting effect. 
         [0045]    2. The a magnetic conducting flange of the fixed unit and the movable unit, the magnetic conducting flange prompting the magnetic force and preventing intake of the article or dust. 
         [0046]    3. The coil can be mounted on a bobbin, and then simplified the assembly and lowering the cost.