Abstract:
The present invention provides some configurations of flexible connections jointly or integrally formed with a movable part and/or a fixed part of a lens module. The flexible connections may move the movable part along an optical axis direction and/or directions perpendicular to the optical axis. The configuration and material of the flexible connections provide an enhanced strength bearing plastic deformation, and hence increasing the structure strength of the lens module. The formation of the flexible connections with the movable part and/or the fixed part with one mold-injection process can reduce parts of the lens module and simply its manufacturing process.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims benefit of U.S. Provisional Patent Application No. 62/078,526 filed Nov. 12, 2014, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a configuration of flexible connections between a movable part and a fixed part of a lens driving module with OIS means and, more particularly, to a configuration of plastic flexible connections jointly or integrally formed with the movable part and/or the fixed part. 
     Description of the Prior Art 
     It is an issue to be addressed for people skilled in a field of optical image capturing technology to reduce or eliminate a hand-shake impact of an image picture from a photographer during a photographing action. Optical image stabilization (OIS) technology is rapidly developed and now has become a primary hand-shake correction technique. The OIS technology can prevent image quality from getting worse caused by software correction and its lengthy process time. Recently, a common magnet scheme is proposed to be used in the OIS technology. The common magnet scheme employs a set of common magnets to drive two sets of coils to move a lens assembly along an optical axis direction and directions perpendicular to the optical axis so as to attain purposes of auto-focusing and hand-shake correction. 
       FIG. 1A  is a schematic side view of a prior-art lens module provided with OIS means utilizing the common magnet scheme.  FIG. 1B  is a schematic top view of the lens module. Several metal suspension wires  16  connect with an upper metal spring  18  to connect a movable part  12  and a fixed part  14  of the lens module. The movable part  12  includes a lens module, auto-focusing coil and a set of magnets except for the upper metal spring  18 . The fixed part  14  includes an OIS coil plate, a printed circuit board and a base. The metal spring  18  is used to restore an original position of the movable part  12  when a photographing action is completed. The metal suspension wires  16  are used to support the movable part  12  on the fixed part  14  and provide electrical connection between the auto-focusing coil and the printed circuit board. The prior art lens module has some drawbacks, for example, the metal spring  18  easily becomes plastic deformation and may generate resonance. The more separate parts of the lens module also make its manufacturing process become complicated. 
     It is desirable to address the above drawbacks for the lens module with OIS means. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide some kinds of configuration of flexible connections jointly or integrally formed with a movable part and/or a fixed part of a lens module to eliminate elements used in the lens module, and hence simplifying its manufacturing process. 
     It is one another object of the present invention to provide flexible connections between the movable part and the fixed part to enhance the structure strength of the lens module. 
     It is a further another object of the present invention to provide flexible connections between the movable part and the fixed part to eliminate resonance phenomenon of the lens module. 
     In one aspect, the present invention provides a lens module comprising a movable part, a fixed part and a plurality of wave-shaped flexible elements connected between the movable part and fixed part. The wave-shaped flexible elements may be jointly or integrally formed with the movable part, or may be jointly or integrally formed with the fixed part. The wave-shaped elements can move the movable part along an optical axis OO′ direction of the lens module and also can move the movable part along directions perpendicular to the optical axis OO′. 
     In one another aspect, the present invention provides a lens module comprising a plurality of first flexible elements jointly or integrally formed with a movable part and a plurality of second flexible elements jointly or integrally formed with a fixed part. The first flexible elements move the movable part along an optical axis of the lens module, and the second flexible elements move the movable part along directions perpendicular to the optical axis. 
     In one embodiment of the present invention, the first flexible elements are wave-shaped and the second flexible elements are composed of ball-shaped sub-elements connected in series. In one alternation, the first flexible elements may be serrated shape at their opposite longitudinal sides. In one alternation, the second flexible element may has a rectangular body each of its surfaces along a longitudinal direction provided with a plurality of concave surfaces and flat surfaces alternately distributed on the surface. In one alternation, the second flexible element may be a cylindrical body. 
     In still one another aspect, the present invention provides a lens module comprising a plurality of first flexible elements and a plurality of second flexible elements jointly or integrally formed with a movable part and a plurality of third flexible elements jointly or integrally with a fixed part. The first flexible elements and second flexible elements move the movable part along an optical axis of the lens module, and the third flexible elements move the movable part along directions perpendicular to the optical axis. In one embodiment of the present invention, the first and second flexible elements may be serrated shape at their opposite longitudinal sides. In one embodiment of the present invention, the third flexible elements are composed of ball-shaped sub-elements connected in series. In one alternation, the third flexible element may has a rectangular body each of its surfaces along a longitudinal direction provided with a plurality of concave surfaces and flat surfaces alternately distributed on the surface. In one alternation, the third flexible element may be a cylindrical body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic side view of a prior-art lens module. 
         FIG. 1B  is a schematic top view of the prior-art lens module. 
         FIG. 2A  is a schematic perspective view of a partial portion of a lens module according to a first embodiment of the present invention. 
         FIG. 2B  is a schematic top view of the partial portion of the lens module according to the first embodiment of the present invention. 
         FIG. 2C  is a schematic exploded view of a partial portion of the lens module of the first embodiment of the present invention. 
         FIG. 3  is a schematic exploded view of a partial portion of a lens module according to a second embodiment. 
         FIG. 4  is another schematic exploded view of the lens module of the second embodiment. 
         FIG. 5A  is a schematic cross-sectional view of a variation of a first flexible element of the lens module of the second embodiment. 
         FIG. 5B  is a schematic side view of the variation of the first flexible element shown in  FIG. 5A . 
         FIG. 6  is a schematic view of a partial portion of a variation of the second embodiment shown in  FIG. 3 . 
         FIG. 7A  is a schematic perspective view of a variation of a second flexible element of the lens module of the second embodiment. 
         FIG. 7B  is a schematic perspective view of another variation of the second flexible element of the lens module of the second embodiment. 
         FIG. 8  is a schematic exploded view of a partial portion of a lens module according to a third embodiment. 
         FIG. 9  is another schematic exploded view of the partial portion of the lens module according to the third embodiment. 
         FIG. 10  is a schematic side view of the lens module of the third embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the present invention are shown. 
       FIG. 2A  is a schematic perspective view of a partial portion of a lens module according to a first embodiment of the present invention, in which some parts and components are omitted in order to clearly show characteristic structures of the present lens module.  FIG. 2B  is a schematic top view of the partial portion of the lens module.  FIG. 2C  is a schematic exploded view of a partial portion of the lens module of the first embodiment, showing a more detailed structure. In the first embodiment, the lens module comprises a movable part  22 , a fixed part  24  and a plurality of wave-shaped plastic flexible elements  26  connecting between the movable part  22  and fixed part  24 . The wave-shaped plastic flexible elements  26  may be jointly or integrally formed with the movable part  22 , or may be jointly or integrally formed with the fixed part  24 . In other words, the wave-shaped plastic flexible elements  26  and the movable part  22  may be formed together with one mold-injection process. Optionally, the wave-shaped plastic flexible elements  26  and the fixed part  24  may be formed together with one mold-injection process. Preferably, the wave-shaped plastic flexible elements  26  may be connected unto outer planar surfaces of the movable part  22  in parallel to an optical axis OO′ of the lens module. Preferably, there are four wave-shaped plastic flexible elements  26  symmetrically connecting between the movable part  22  and the fixed part  24 . Specifically, see  FIG. 2C , the movable part  22  has four symmetric cutting corners respectively accommodating the four wave-shaped plastic flexible elements  26 . Each of the four cutting corners forms an outer planar surface of the movable part  22  in parallel to the optical axis OO′ of the lens module so that the wave-shaped plastic flexible element  26  may be integrally connected unto the outer planar surface of the movable part  22 . By the configuration of the cutting corner, the length of the wave-shaped plastic flexible elements  26  can be extended to enhance its strength bearing plastic deformation. Please note the wave-shaped flexible element  26  is not limited to be made of plastic material. Other material, such as metal material may be used to form the wave-shaped flexible element  26 . Also, the wave-shaped plastic flexible elements  26  may be un-symmetrically connected unto the movable part  22  and the fixed part  24 . As shown in  FIG. 2A  and  FIG. 2B , the wave-shaped plastic flexible elements  26  can move the movable part  22  along the optical axis OO′ direction and also can move the movable part  22  along directions perpendicular to the optical axis OO′. See  FIG. 2C , the lens module of the first embodiment further comprises an X-axis AF coil  242  positioned at an inner side wall of the fixed part  24  and an Y-axis AF (Auto-Focusing) coil  244  positioned at another inner side wall of the fixed part  24 . An OIS coil plate  23  is positioned below the movable part  22 , and an X-axis OIS (Optical Image Stabilization) coil  232  and an Y-axis OIS coil  234  respectively provided on the OIS coil plate  23 . An X-axis magnet  28  is positioned at one outer side wall of the movable part  22 , with a surface facing the X-axis AF coil  242  and another surface facing the X-axis OIS coil  232 . An Y-axis magnet  29  is positioned at another outer side wall of the movable part  22 , with a surface facing the Y-axis AF coil  244  and another surface facing the Y-axis OIS coil  234 . A flexible printed circuit board  25  is positioned under the OIS coil plate  23 . A base  27  is disposed below the flexible printed circuit board  25 . However, the lens module of the first embodiment is not limited by two magnets scheme and/or two coils scheme. Four magnets scheme and/or four coils scheme also may be applied instead of the configurations of the magnets and AF/OIS coils of the first embodiment. The fixed part  24 , the OIS coil plate  23 , the flexible printed circuit board  25  and the base  27  are unmoved when performing an auto-focusing action and a hand-shaking correction action. 
       FIG. 3  is a schematic exploded view of a lens module with OIS means according to a second embodiment of the present invention.  FIG. 4  is another schematic exploded view of the lens module of the second embodiment. In the second embodiment, the lens module comprises an upper cover  30 , a frame  31 , a lens barrel  32  in which lenses and some other elements are omitted, an auto-focusing coil  33 , a set of magnets  34 , an OIS coil plate  35 , a printed circuit board  36  and a base  37 . Preferably, the lens barrel  32  is provided with four L-shaped accommodation space  322  symmetrically around an upper portion of its outer surrounding. Four first plastic flexible elements  38  are individually received in one of the L-shaped accommodation space  322 , and being jointly or integrally formed with the lens barrel  32 . Specifically, an outer planar surface of the lens barrel  32  in parallel to an optical-axis direction (i.e. Z-axis direction) of the lens barrel  32 , and an outer planar surface of the lens barrel  32  perpendicular to the optical axis constitute the L-shaped accommodation space  322 . The first plastic flexible element  38  may be integrally connected unto the outer planar surface of the lens barrel  32  in parallel to the optical axis. It means the first plastic flexible elements  38  and the lens barrel  32  may be formed together with one mold-injection process. Alternatively, the first plastic flexible elements  38  may be jointly or integrally formed with the frame  31 . In other words, the first plastic flexible elements  38  and the frame  31  can be formed together with one mold-injection process. Please note this configuration is not shown in a drawing but one skilled person in the art would readily know how to accomplish this configuration in view of the configuration of the first plastic flexible elements  38  and the lens barrel  32 . The design of the L-shaped accommodation space  322  can advantageously lengthen the first plastic flexible element  38  to enhance its strength bearing plastic deformation without increasing the volume of the lens module. The lens barrel  32  is provided with an accommodation space at its lower portion for placing the auto-focusing coil  33 . The magnets  34  are symmetrically positioned to face the auto-focusing coil  33 . The frame  31  accommodates the lens barrel  32 , the auto-focusing coil  33 , the magnets  34  and the first plastic flexible element  38 . One end of each of the first plastic flexible elements  38  is jointed to one corner of the frame  31  such that the first plastic flexible elements  38  are symmetrically positioned between the frame  31  and the lens barrel  32 . Please note the first flexible element  38  is not limited to be made of plastic material. Other material, such as metal material may be used to form the first flexible element  38 . Also, the first plastic flexible elements  38  may be un-symmetrically connected unto the lens barrel  32  and thus may be un-symmetrically connected unto the frame  31 . Four second plastic flexible elements  39  are symmetrically and individually provided at four corners of the printed circuit board  36 . The second plastic flexible elements  39  are jointly or integrally formed with the printed circuit board  36 . It means the second plastic flexible elements  39  and the printed circuit board  36  may be formed together with one mold-injection process. Alternatively, the second plastic flexible elements  39  may be jointly or integrally formed with the frame  31 . It means the second plastic flexible elements  39  and the frame  31  may be formed together with one mold-injection process. Please note this configuration is not shown in a drawing but one skilled person in the art would readily know how to accomplish this configuration in view of the configuration of the second plastic flexible elements  39  and the printed circuit board  36 . One end of each of the second plastic flexible elements  39  opposite to the printed circuit board  36  is jointed to one corner of the frame  31  such that the second plastic flexible elements  39  are symmetrically positioned between the frame  31  and the printed circuit board  36 . Please note the second flexible element  39  is not limited to be made of plastic material. Other material, such as metal material may be used to form the second flexible element  39 . Also, the second plastic flexible elements  39  may be un-symmetrically connected unto the lens barrel  32  and thus may be un-symmetrically connected unto the frame  31 . The OIS coil plate  35  is positioned between the frame  31  and the printed circuit board  36 , and electrically communicated with the printed circuit board  36 . The OIS coil plate  35  comprises several coils face the magnets  34  and share the magnets  34  with the auto-focusing coil  33 . The printed circuit board  36  is positioned on the base  37 , and the upper cover  30  houses the frame  31 , the lens barrel  32 , the auto-focusing coil  33 , the magnets  34 , the OIS coil plate  35  and the printed circuit board  36 , the first plastic flexible elements  38  and the second plastic flexible elements  39 . The frame  31 , the lens barrel  32 , the auto-focusing coil  33 , the magnets  34  and the first plastic flexible elements  38  constitute a movable part of the present lens module. The OIS coil plate  35 , the printed circuit board  36 , the base  37  and the second plastic flexible elements  39  constitute a fixed part of the lens module. The first plastic flexible elements  38  move the movable part along the optical axis direction, i.e. Z-axis direction in the second embodiment, to perform auto-focusing function. The second plastic flexible elements  39  move the movable part along directions perpendicular to the optical axis, i.e. X and Y directions. 
     Preferably, the first plastic flexible elements  38  are wave-shaped.  FIG. 5A  shows a schematic cross-sectional view of a variation of the first plastic flexible elements  38 , and  FIG. 5B  shows a schematic side view of the variation. In the variation, the first plastic flexible elements  38   a  are serrated shape at its opposite longitudinal sides.  FIG. 6  is a schematic view of a partial portion of a variation of the second embodiment shown in  FIG. 3 . In the variation, the lens barrel  32  is provided with four cutting corners instead of the L-shaped accommodation spaces  322  such that the first plastic flexible element  38  still can keep its original length when positioned at the cutting corner. An outer planar surface of the lens barrel  32  in parallel to the optical axis forms the cutting corner. The cutting corner aligns with an outer surface of the auto-focusing coil  33 . Preferably, the second plastic flexible elements  39  are formed of a plurality of ball-shaped sub-elements connected in series.  FIG. 7A  shows a schematic perspective view of a variation of the second plastic flexible elements  39 . In the variation, the second plastic flexible element  39   a  has a rectangular body each of its surface along a longitudinal direction provided with a plurality of concave surfaces and flat surfaces alternately distributed on the surface.  FIG. 7B  shows a schematic perspective view of another variation of the second plastic flexible elements  39 . In the variation shown in  FIG. 7B , the second plastic flexible element  39   b  is formed of a cylindrical body. Please note the flexible elements of these variations may not be limited to plastic material and may be made of metal material. 
       FIG. 8  is a schematic exploded view of a lens module with OIS means according to a third embodiment of the present invention.  FIG. 9  is another schematic exploded view of the lens module of the third embodiment.  FIG. 10  is a schematic cross-sectional view of the lens module without an upper cover of the third embodiment. In the third embodiment, the lens module comprises an upper cover  80 , a base  81 , a frame  82 , a lens barrel  83  in which lenses and some other elements are omitted, an auto-focusing coil  84 , a set of magnets  85 , an OIS coil plate  86  and a printed circuit board  87 . Preferably, the lens barrel  83  is provided with four L-shaped accommodation space  832  symmetrically around an upper portion of its outer surrounding. Four first plastic flexible elements  88   a  are individually received in one of the L-shaped accommodation space  832 , and being jointly or integrally formed with the lens barrel  83 . It means the first plastic flexible elements  88   a  and the lens barrel  83  may be formed together with one mold-injection process. Alternatively, the four first plastic flexible elements  88   a  may be jointly or integrally formed with the frame  82 . It means the first plastic flexible elements  88   a  and the frame  82  may be formed together with one mold-injection process. Please note this configuration is not shown in a drawing but one skilled person in the art would readily know how to accomplish this configuration in view of the configuration of the first plastic flexible elements  88   a  and the lens barrel  83 . The design of the L-shaped accommodation space  832  can advantageously lengthen the first plastic flexible element  88   a  to enhance its strength bearing plastic deformation without increasing the volume of the lens module. Four second plastic flexible elements  88   b  are symmetrically positioned at a lower outer portion of the lens barrel  83 , and being jointly or integrally formed with the lens barrel  83 . Each of the four second plastic flexible elements  88   b  corresponds to one of the first plastic flexible elements  88   b . The second plastic flexible element  88   b  is shorter than the first plastic flexible element  88   a . In the third embodiment, the first plastic flexible elements  88   a , the second plastic flexible elements  88   b  and the lens barrel  83  may be formed together with one mold-injection process. Alternatively, the second plastic flexible elements  88   b  may be jointly or integrally formed with the frame  82 . It means the second plastic flexible elements  88   b  and the frame  82  may be formed together with one mold-injection process. Please note this configuration is not shown in a drawing but one skilled person in the art would readily know how to accomplish this configuration in view of the configuration of the second plastic flexible elements  88   b  and the lens barrel  83 . The lens barrel  83  is provided with an accommodation space at its lower portion for placing the auto-focusing coil  84 . The magnets  85  are symmetrically positioned to face the auto-focusing coil  84 . The frame  82  accommodates the lens barrel  83 , the auto-focusing coil  84 , the magnets  85 , the first plastic flexible elements  88   a  and the second plastic flexible elements  88   b . One end of each of the first plastic flexible elements  88   a  is jointed to one upper corner of the frame  82  such that the first plastic flexible elements  88   a  are symmetrically positioned between the frame  82  and the lens barrel  83 . One end of each of the second plastic flexible elements  88   b  is jointed to one lower corner of the frame  82  such that the second plastic flexible elements  88   b  are symmetrically positioned between the frame  82  and the lens barrel  83 . Four third plastic flexible elements  89  are symmetrically and individually provided at four corners of the printed circuit board  87 . The third plastic flexible elements  89  are jointly or integrally formed with the printed circuit board  87 . It means the third plastic flexible elements  89  and the printed circuit board  87  may be formed together with one mold-injection process. Alternatively, the third plastic flexible elements  89  may be jointly or integrally formed with the frame  82 . It means the third plastic flexible elements  89  and the frame  82  may be formed together with one mold-injection process. Please note this configuration is not shown in a drawing but one skilled person in the art would readily know how to accomplish this configuration in view of the configuration of the third plastic flexible elements  89  and the printed circuit board  87 . One end of each of the third plastic flexible elements  89  opposite to the printed circuit board  87  is jointed to one corner of the frame  82  such that the third plastic flexible elements  89  are symmetrically positioned between the frame  82  and the printed circuit board  87 . The OIS coil plate  86  is positioned between the frame  82  and the printed circuit board  87 , and electrically communicated with the printed circuit board  87 . The OIS coil plate  86  comprises several coils face the magnets  85  and share the magnets  85  with the auto-focusing coil  84 . The printed circuit board  87  is positioned on the base  81 , and the upper cover  80  houses the frame  82 , the lens barrel  83 , the magnets  85 , the OIS coil plate  86  and the printed circuit board  87 , the first plastic flexible elements  88   a , the second plastic flexible elements  88   b  and the third plastic flexible elements  89 . The frame  82 , the lens barrel  83 , the auto-focusing coil  84 , the magnets  85 , the first plastic flexible elements  88   a  and the second plastic flexible elements  88   b  constitute a movable part of the present lens module. The OIS coil plate  86 , the printed circuit board  87 , the base  81  and the third plastic flexible elements  89  constitute a fixed part of the lens module. The first and second plastic flexible elements  88   a  and  88   b  move the movable part along an optical axis direction, i.e. Z-axis direction in the third embodiment, to perform auto-focusing function. The third plastic flexible elements  89  move the movable part along directions perpendicular to the optical axis, i.e. X and Y directions. 
     Preferably, the first and second plastic flexible elements  88   a  and  88   b  have a rectangular body provided with two opposite serrated surfaces along its longitudinal direction. Preferably, the third plastic flexible elements  89  are formed of a plurality of ball-shaped sub-elements connected in series. Optionally, the variation shown in  FIG. 7A  and  FIG. 7B  can be used instead of the third plastic flexible elements  89 . 
     While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention.