Abstract:
A motor structure with a built-in lens includes a lens mount ( 10 ), a motor ( 30 ) received in the lens mount, and a lens unit ( 50 ) received in the lens mount. The lens unit is drove by the motor to telescopically move along an axial thereof when a rotor ( 34 ) of the motor is rotated. A guiding member ( 70 ) arranged on an end of the motor for preventing an axial movement of the motor. The guiding member includes at least a leg ( 78 ) extending along an axial direction therefrom for guiding the axial movement of the lens unit.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to drive source of camera lens, and more particularly to a drive source with built-in camera lens.  
       DESCRIPTION OF RELATED ART  
       [0002]     The traditional structure of camera lens affixes a drive motor on an outside of a camera lens mount and, through the connection of transmission parts, the drive motor drives the telescopic lens in telescopic motion. Since the drive motor is located at the outside of the camera lens mount, the drive motor requires extra transmission parts in the camera lens mount to drive the telescopic lens to move, which often encounters the following drawbacks.  
         [0003]     Since the drive motor is affixed to the outside of the camera lens mount, the structure of the camera lens is asymmetrical, which affects the spatial disposition of the camera lens module consisting of the camera lens mount and the telescopic lens. The telescopic lens may experience problem of run out in the telescopic motion. The extra transmission parts, which drive the telescopic lens to move inside the camera lens mount, add cost and complexity to the camera lens.  
       SUMMARY OF THE INVENTION  
       [0004]     According to a preferred embodiment of the present invention, a motor structure with a built-in lens comprises a lens mount, a motor received in the lens mount, and a lens unit received in the motor. The lens unit has an external thread engaging with an internal thread defined in a rotor of the motor. The lens unit is driven by the motor to telescopically move along an axial direction thereof. A guiding member is arranged on an end of the motor for guiding the telescopic movement of the lens unit. An annular protrusion extends outwardly from the guiding member. The protrusion is sandwiched between the motor and the lens mount for preventing an axial movement of the motor and swing of the rotor. A plurality of legs extend along an axial direction from the guiding member and fit in grooves of the lens unit for guiding the axial movement of the lens unit. By the legs, rotation of the lens unit is prevented. On the other hand, the legs guide the lens unit to move along the axial direction thereof, resulting in stable telescopic axial movement of the lens unit. Therefore the motor can drive the lens unit into stable and accurate movement.  
         [0005]     Other advantages and novel features of the present invention will be drawn from the following detailed description of a preferred embodiment of the present invention with attached drawings, in which: 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]     Many aspects of the present motor structure 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 motor structure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views:  
         [0007]      FIG. 1  is an isometric, exploded view of a motor structure with built-in lens in accordance with a preferred embodiment of the present invention;  
         [0008]      FIG. 2  is an assembled view of  FIG. 1 ;  
         [0009]      FIG. 3  shows a cross-sectional view of the motor structure of  FIG. 2 ; and  
         [0010]      FIG. 4  is similar to  FIG. 3 , but showing a lens unit of the motor structure in telescopic motion. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0011]     Referring to  FIGS. 1 through 3 , a motor structure with built-in lens according to a preferred embodiment includes a lens mount  10 , a motor  30  received in the lens mount  10 , a lens unit  50  being drivable by the motor  30 , a guiding member  70  and a supporting member  90  arranged at top and bottom end of the motor  30 , respectively.  
         [0012]     The lens mount  10  includes a bottom cover  12  and a top cover  14  located above and facing the bottom cover  12 . Each of the top and bottom covers  14 ,  12  includes a ring-shaped basewall  142 ,  122  and a sidewall  140 ,  120 . Each sidewall  140 ,  120  extends perpendicularly from an outer-periphery of a corresponding basewall  142 ,  122  towards the other basewall  122 ,  142 . The top and bottom covers  14 ,  12  cooperatively define a column-shaped space therein when the top and bottom covers  14 ,  12  are assembled together. The two sidewalls  140 ,  120  cooperatively form the sidewall of the lens mount  10 . An opening  148 ,  128  is defined in a free end of each of the sidewalls  140 ,  120 , respectively. Together the openings  148 ,  128  define a passage  18  in the sidewall of the lens mount  10  for extension of wires  324  therethrough to connect the motor  30  with a power source (not shown). Through holes  144 ,  124  are defined in central portions of the two basewalls  142 ,  122 , respectively. The through holes  144 ,  124  communicate with the space of the lens mount  10 . Flanges  146 ,  126  extend perpendicularly from inner circumferences of the basewalls  142 ,  122 , respectively. The flange  146  extends upwardly, while the flange  126  extends downwardly.  
         [0013]     The motor  30  is received in the space of the lens mount  10 . The motor  30  is cylindrical-shaped and hollow. The outer diameter of the motor  30  is approximately the same as the inner diameter of the sidewall of the lens mount  10 . The inner diameter of the motor  30  is smaller than the diameter of the through holes  144 ,  124  of the basewalls  142 ,  122 . The motor  30  includes a stator  32  and a rotor  34  being rotatably received in the stator  32 . The stator  32  includes a stator core  320  having a plurality of poles and windings  322  wound around the stator core  320 . The windings  322  electrically connect with the wires  324 . The rotor  34  includes a cylindrical-shaped shell  342  and a magnet  340  adhered to an outer surface of the shell  342 . An internal thread  344  is formed on an inner surface of the shell  342 .  
         [0014]     The lens unit  50  is linearly movably received in the hollow shell  342  of the rotor  34 . An external thread  54  is formed in an outer surface  52  of the lens unit  50  to threadedly engage with the internal thread  344  of the rotor  34 . Six grooves  56  are defined in the outer surface  52  of the lens unit  50 . The grooves  56  are equidistantly spaced from each other in the outer surface  52  of the lens unit  50 , and extend through the lens unit  50  along an axial direction thereof.  
         [0015]     The supporting member  90  and the guiding member  70  are ring shaped. A circular hole  94 ,  74  is defined in a central portion of the supporting (guiding) member  90  ( 70 ). The outer diameter of each of the two members  90 ,  70  is approximately the same as the diameter of each of the through holes  144 ,  124  of the basewalls  142 ,  122  of the lens mount  10 , and the inner diameter of each of the two members  90 ,  70  is approximately the same as the outer diameter of the lens unit  50 . An annular protrusion  92 ,  72  extends radially and outwardly from an outer periphery of a positioning end (not labeled) of the supporting (guiding) member  90  ( 70 ). An annular step  96 ,  76  is defined in an inner circumference of the positioning end of the supporting (guiding) member  90  ( 70 ). Three legs  78  extend downwardly from the guiding member  70  and equidistantly spaced from each other along a circumferential direction of the guiding member  70 . Each leg  78  is elongated. The two members  90 ,  70  are made of plastic, such as Polyacetal or Polyphylene Sulfide. Also the members  90 ,  70  can be made of other high abrasion resistant material, such as ceramic, metal etc. The rotor  34  has a bottom end rotatably engaging with the supporting member  90  and a top end rotatably engaging with the guiding member  70 . The supporting and guiding members  90 ,  70  have a low friction.  
         [0016]     When assembled, the top cover  14  mounted on the bottom cover  12  to define the space receiving the motor  30  therein. The lens unit  50  is movable received in the hollow motor  30  with the external thread  54  screwing on the internal thread  344  of the rotor  34 . The supporting member  90  is sandwiched between the bottom end of the motor  30  and the bottom cover  12 , and the guiding member  70  is sandwiched between the top end of the motor  30  and the top cover  14 . The supporting member  90  and the guiding member  70  extend into the through hole  144 ,  124  of the basewall  142 ,  122  and abut against the inner circumference of the bottom and top covers  14 , respectively, whereby the two members  90 ,  70  are prevented from rotation. The protrusion  92  of the supporting member  90  is sandwiched between the bottom cover  12  and the bottom end of the rotor  34  of the motor  30 , whilst the protrusion  72  of the guiding member  70  is sandwiched between the top cover  14  and the top end of the motor  30 , whereby an axial movement of the two members  90 ,  70  is prevented. The bottom and top ends of the rotor  34  are received in the steps  96 ,  76  of the supporting member  90  and guiding member  70 , respectively. Each leg of the guiding member  70  extends into a corresponding groove  56  of the lens unit  50  to guide the movement of the lens unit  50 .  
         [0017]     Referring to  FIG. 4 , during operation, a current is applied to the windings  322  of the motor  30  through the wires  324 . The rotor  34  is driven to rotate by the interaction of the alternating magnetic field established by the stator  32  and the magnetic field of the rotor  34 . The rotation of the rotor  34  then turns to the axial telescopic movement of the lens unit  50  through the action between the internal thread  344  of the rotor  34  and the external thread  54  of the lens unit  50 . Therefore the motor  30  acts as a stepper motor to drive the lens unit  50  into telescopic movement along the axial direction of the lens unit  50 . For the motor  30  is directly built inside the cylindrical-shaped lens mount  10 , a symmetrical ring shape structure is formed to improve the flexibility of the spatial disposition of the motor structure. The motor  30  delivers omnidirectional drive to eliminate run out occurring during the telescopic motion of the telescopic lens unit  50 . The guiding member  70  and the supporting member  90  abut the top and bottom ends of the rotor  34  to limit the axial movement of the rotor  34 . The steps  96 ,  76  of the two members  90 ,  70  abut the rotor  34  to avoid swing of the rotor  34 . Thus, a stable and precise rotation of the rotor  34  can be obtained. The legs  78  of the supporting member  90  are received in the grooves  56  of the lens unit  50 , thereby avoiding rotation of the lens unit  50  during the telescopic movement thereof. On the other hand, the legs  78  guide the lens unit  50  to move linearly along the axial direction thereof, resulting in stable telescopic axial movement of the lens unit  50 . Thus, the motor  30  can drive the lens unit  50  into stable and accurate movement.  
         [0018]     It is understood that the invention may be embodied in other forms without departing from the spirit thereof. Thus, the present example and embodiment is to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.