Abstract:
An exemplary lens module includes a holder, a lens barrel, a cover having a through hole, a restricting member having a slit, a handle extending from the lens barrel and a resilient. The lens barrel is accommodated in the holder capable of moving along a central axis of the holder. The cover covers the lens barrel and is detachably fixed on the holder. The restricting member is over the cover. The handle penetrates the through hole and the slit. The resilient member is sandwiched between the cover and the lens barrel, capable of changing the length thereof under an external force and recovering the original length with the external force withdrawn, such that a focal length of the lens module is adjustable by moving the handle in and along the slit.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to a lens module, and more particularly, a lens module having intercoupling slit and handle. 
         [0003]    2. Description of Related Art 
         [0004]    A conventional zoom lens module generally includes at least one lens, an image sensor and an actuator, such as a step motor for driving the lenses to move relative to the image sensor for obtaining a desired focal length. However, the zoom lens module is expensive. Furthermore, the step motor is relatively large in volume, thus a significant amount of space is needed for movement of the lenses, which makes it very difficult to reduce a volume of the lens module. 
         [0005]    Therefore, a lens module to overcome the problems described above is needed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Many aspects of the present disclosure 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 embodiments of the lens module. Moreover, in the drawings, all the views are schematic, and like reference numerals designate corresponding parts throughout the different views. 
           [0007]      FIG. 1  is a schematic, exploded view of a lens module in accordance with a first embodiment. 
           [0008]      FIG. 2  shows another isometric, exploded view of the lens module of  FIG. 1 . 
           [0009]      FIG. 3  shows a schematic, and perspective view of the lens module of  FIG. 1 . 
           [0010]      FIG. 4  is a sectional view of the lens module of  FIG. 1 , corresponding to line IV-IV. 
           [0011]      FIG. 5  shows the lens module of  FIG. 1  in a focus state. 
           [0012]      FIG. 6  is an isometric, exploded view of a lens module in accordance with a second embodiment. 
           [0013]      FIG. 7  is an isometric, exploded view of a lens module in accordance with a third embodiment. 
           [0014]      FIG. 8  is an isometric, exploded view of a lens module in accordance with a fourth embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Referring to  FIGS. 1-4 , a lens module  10  provided in a first embodiment includes a holder  11 , a lens barrel  12 , a resilient member  14 , a cover  13  and a restricting member  15 . 
         [0016]    Referring to  FIG. 1 , the holder  11  includes a first hollow cylinder  111  for accommodating an image sensor (not shown) and a second hollow cylinder  110  for accommodating the lens barrel  12 . The second cylinder  110  has an inner surface  112 , an outer surface  113  opposite to the inner surface  112 , and outer threads  115  formed on the outer surface  113 . An inner diameter of the first cylinder  111  is greater than that of the second cylinder  110 , and an outer diameter of the first cylinder  111  is less than that of the second cylinder  111 . That is, the second cylinder  110  is thicker than the first cylinder  111 , and an annular portion of an end surface (not labeled) of the first cylinder  111 , here defined as a supporting surface  116 , is accessible from the second cylinder  110 . Three arc-shaped steps  117  arrange equidistantly on the supporting surface  116 . Each step  117  has a carrying surface  119  parallel to the supporting surface  116  and a sloping end surface  118  interconnecting the carrying surface  119  and the supporting surface  116 . The sloping end surface  118  also intersects with the inner surface  112  of the second cylinder  110  on a curve. In this manner, three sloping end surfaces  118  arrange uniformly, and the step  117  has a gradually increase in height in the sloping end surface  118  along a direction from the supporting surface  116  upward. 
         [0017]    Referring to  FIG. 1 , the lens barrel  12  includes an inner barrel  120  for accommodating optical elements, such as optical lenses, spacers, filters etc. In addition, the lens barrel  12  further includes an outer barrel  121  for threadedly engaging the inner barrel  12 . 
         [0018]    Referring to  FIGS. 1 and 2 , the outer barrel  121  includes a hollow coupling cylinder  1211 . The coupling cylinder  1211  has a first end surface  1217 , a second end surface  1216 , a side surface  1215  interconnecting the first end surface  1217  and the second end surface  1216 . Three arc-shaped coupling members  1218  are equidistantly formed on the second end surface  1216 . The coupling cylinder  1211  is detachably accommodated in the second cylinder  110  with the side surface  1215  contacting the inner surface  112 , capable of rotating around and moving along a central axis of the second cylinder  110 . Referring to  FIG. 2 , each coupling member  1218  includes an arc-shaped plate  1219  and a hemispherical protrusion  1220  protruding from an end portion of the arc-shaped plate  1219 . A length of the plate  1219  is substantially equal to the distance between every two neighboring steps  117 , and a distance between every two neighboring coupling members  1218  is substantially equal to that between every two neighboring steps  117 . As such, the coupling member  1218  can be restricted between two neighboring steps  117 . 
         [0019]    Additionally, referring to  FIG. 1 , the outer barrel  121  further includes a hollow accommodating cylinder  1210  perpendicularly and coaxially extending from the first end surface  1217  of the coupling member  1211 . Narrower than the coupling member  1211 , the accommodating cylinder  1210  configures for threadedly engaging with the inner barrel  120 . The accommodating cylinder  1210  has a third end surface  1213  parallel to the first end surface  1217  of the coupling cylinder  1211 . A handle  1214  perpendicularly extends from the third end surface  1213  of the accommodating cylinder  1210 . 
         [0020]    Referring to  FIGS. 2 and 4 , the cover  13  has inner threads  132  formed in an inner surface thereof, which corresponds to the outer threads  115  of the second cylinder  110 . The cover  13  can be detachably mounted on the second cylinder  110  with the inner threads  132  being mated with the outer threads  115 . Referring to  FIG. 1 , the cover  13  also has a through hole  133  in the central portion thereof. A diameter of the through hole  133  is greater than that of the accommodating cylinder  1210  but less than that of the coupling member  1211 . 
         [0021]    Referring to  FIGS. 1 and 4 , the resilient member  14  is detachably sandwiched between the cover  13  and the coupling cylinder  1211 . The resilient member  14  has a ring-shaped plate  140 . The ring-shaped plate  140  has an opening  1401  in the center thereof, and three grooves  1402  equidistantly around and communicating with the opening  1401 . Therefore, a wider connection section  1403  between every two neighboring grooves  1402  is obtained. The opening  1401  is wider than the accommodating cylinder  1210  and narrower than the coupling cylinder  1211 . That is, the resilient member  14  is assembled on the first end surface  1217  of the coupling cylinder  1211 , and the accommodating cylinder  1210  and the handle  1214  pass through the plate  140 . Three elongated tabs  143  are uniformly stamped out from the plate  140 . When not under stressed condition, the tabs  143  are substantially parallel with the plate  140 . When under completely compression, the tabs  143  fill the grooves  1402  and are coplanar with the plate  140 . 
         [0022]    The restricting member  15  has an arc-shaped slit  150  for fittingly accommodating the handle  1214 . The slit  150  has a first end  151  and a second end  152 . In actual use, the restricting member  15  is transparent and fixed on a body of an electronic device, such as a mobile phone, a portable computer, etc. The restricting member  15  is also configured for preventing contaminants entering the lens module  10 . 
         [0023]    Referring to  FIGS. 1 ,  2 ,  3  and  4 , in assembly of the lens module  10 , the inner barrel  120  is first screwed into the outer barrel  121  to form the lens barrel  12 . The lens barrel  12  is then put into the second cylinder  110  of the holder  11  with the protrusions  1216  contacting the supporting surface  116  of the first cylinder  111 . The resilient member  14  is subsequently mounted on the first end surface  1217  of the coupling cylinder  1211  with the surrounding accommodating cylinder  1210 . The cover  13  screws onto the second cylinder  110  of the holder  11  with the tabs  143  not under stressed condition. The restricting member  15  is fixed over the cover  13  with the handle  1214  passing through the resilient member  14  and blocked at the first end  151  of the restricting slit  150 . In this situation, a first desired focal length of the lens module  10  is obtained. 
         [0024]    Referring to  FIGS. 1 ,  3  and  5 , when moving the handle  1214  in the slit  150 , the coupling member  1218  of the coupling cylinder  1211  is simultaneously movable in a direction from the supporting surface  116  to the carrying surface  119  via the sloping end surface  118  of the step  117 , and the tabs  143  are stressed. When restricting the handle  1214  at the second end  152  of the slit  150 , the protrusions  1220  holds to the carrying surface  119 , the tabs  143  fill the grooves  1402  and become coplanar with the plate  140 . Therefore, a distance between the inner barrel  120  and the first cylinder  111 , i.e., a distance between optical lenses and imaging sensor, shortens. In such way, a second desired focal length of the lens module  10  is obtained. 
         [0025]    Referring to  FIG. 6 , a lens module  20  provided in a second embodiment has similar configuration with the lens module  10 , differing in that the outer barrel  121  is used for accommodating optical members. In addition, the holder  21  includes the first cylinder  211  and the second cylinder  210  substantially wider than the first cylinder  211 . The first cylinder  211  has an annular supporting element  2111  coaxially fixed therein. The steps  217  are equidistantly formed on the supporting surface  216  of the supporting member  2111 . 
         [0026]    Referring to  FIG. 7 , a lens module  30  provided in a third embodiment has similar configuration with the lens module  10 . In detail, the lens module  30  includes a holder  31 , a lens barrel  32 , a resilient member  34 , a cover  33  and a restricting member  35 . The holder  31  includes a first hollow cylinder  311  and a second hollow cylinder  310  coaxially connecting the first cylinder  311 . The first hollow cylinder  311  is wider and thicker than the second hollow cylinder  310 , and has an annular supporting surface  316  exposed from the second hollow cylinder  310 . The lens barrel  32  includes an accommodating cylinder  3210  and a coupling cylinder  3211 . The resilient member  34  includes an annular plate  340  and three tabs  343 . The restricting member  35  has an arc-shaped slit  350 . 
         [0027]    The lens module  30  differs from the lens module  10  in that the inner barrel  320  and the coupling cylinder  3211  are respectively threadedly engaged in the accommodating cylinder  3210  of the outer barrel  321  and the second cylinder  310 . When moving the handle  3214  in and along the slit  350 , the outer barrel  121  rotates around and moves toward the cover  33  along the central axis of the second cylinder  310 . Simultaneously, the juncture element  342  and the valve element  343  stress the resilient member  34  until entering into the grooves  3402  of the plate  340 . Therefore, the focal length of the lens module  30  is changed. 
         [0028]    Referring to  FIG. 8 , a lens module  40  provided in a fourth embodiment has similar configuration with the lens module  30 . In detail, the lens module  40  includes a cylinder holder  41 , a lens barrel  421 , a resilient member  44 , a cover  43  and a restricting member  45 . The lens barrel  421  includes an accommodating cylinder  4210  and a coupling cylinder  4211 . The restricting member  45  has an arc-shaped slit  450 . 
         [0029]    The lens module  40  differs from the lens module  30  in that the accommodating cylinder  4210  is for accommodating optical members. The holder  41  includes an annular supporting element  415  fixed on an intermediate portion of an inner surface thereof. The supporting element  415  has a supporting surface  4151 . The holder  41  includes a first portion  411  and a second portion  410  substantially wider than the first portion  411 . The second portion  410  has inner screws  4101  mated with the screws (not labeled) of the coupling cylinder  4211  and outer screws  4102  mated with the screw (not shown) of the cover  43 . 
         [0030]    While certain embodiments have been described and exemplified above, various other embodiments will be apparent from the foregoing disclosure to those skilled in the art. The present disclosure is not limited to the particular embodiments described and exemplified but is memberable of considerable variation and modification without departure from the scope and spirit of the appended claims.