Patent Publication Number: US-11656531-B2

Title: Camera module

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation Application of U.S. patent application Ser. No. 15/481,897, filed Apr. 7, 2017, which claims the benefit of U.S. Provisional Application No. 62/320,096, filed Apr. 8, 2016, U.S. Provisional Application No. 62/356,874, filed Jun. 30, 2016, and Taiwan Patent Application No. 106108890, filed Mar. 17, 2017, the entirety of which are incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The application relates in general to a camera module, and in particular, to a camera module having an elastic member, wherein the elastic member has at least one metal wire. 
     Description of the Related Art 
     As technology has advanced, a lot of electronic devices (for example, cameras and smartphones) have the functionality of taking photographs or recording video. These electronic devices have become more commonplace, and have been developed to be more convenient and thin. More and more choices are provided for users to choose from. 
     Generally, an electronic device having the functionality of taking photographs or recording video includes a driving module to drive one or more optical lens units to move along an optical axis, so as to facilitate auto-focus and auto-zoom controls. The light can pass through the optical lens units and form an image on an image sensor. 
     However, since electronic devices have become light and thin, it is hard to dispose a circuit board or lines therein. Therefore, how to address the aforementioned problem has become an important issue. 
     BRIEF SUMMARY OF INVENTION 
     To address the deficiencies of conventional products, an embodiment of the invention provides a camera module, including a lens driving mechanism, a lens unit, a housing, and an elastic member. The lens unit is disposed on the lens driving mechanism, and the housing surrounds the lens driving mechanism. The elastic member is connected to the lens driving mechanism, and includes a metal base, a first insulation layer, and a first metal wire. The first insulation layer is disposed between the metal base and the first metal wire, and the first metal wire is electrically connected to the lens driving mechanism. 
     In some embodiments, the thickness of the metal base exceeds the total thickness of the first insulation layer and the first metal wire. 
     In some embodiments, the thickness of the metal base is 0.02 mm-0.35 mm. 
     In some embodiments, the first metal wire is formed on the first insulation layer by using a molded interconnect device. 
     In some embodiments, the first metal wire is formed on the first insulation layer by coating. 
     In some embodiments, the metal base and the first metal wire have the same coefficient of thermal expansion. 
     In some embodiments, the elastic member further comprises a plurality of first metal wires formed on the first insulation layer, wherein the first metal wires are electrically independent. 
     In some embodiments, the lens driving mechanism comprises a lens holder, and the elastic member further comprises a first fixed portion, a second fixed portion connected to the lens holder, and a string portion connected to the first fixed portion and the second fixed portion. The lens unit is disposed in the lens holder, and a plurality of electrically independent first metal wires are disposed on the string portion. 
     In some embodiments, the elastic member further comprises a second insulation layer and at least one second metal wire, wherein the second insulation layer is disposed between the second metal wire and the metal base, and the metal base is disposed between the first insulation layer and the second insulation layer. 
     In some embodiments, the thickness of the metal base exceeds the total thickness of the second insulation layer and the second metal wire. 
     In some embodiments, the first metal wire is formed on the second insulation layer by using a molded interconnect device. 
     In some embodiments, the first metal wire is formed on the second insulation layer by coating. 
     In some embodiments, the metal base and the second metal wire have the same coefficient of thermal expansion. 
     In some embodiments, the elastic member further comprises a plurality of second metal wires formed on the second insulation layer, wherein the second metal wires are electrically independent. 
     In some embodiments, the lens driving mechanism comprises a lens holder, and the elastic member further comprises a first fixed portion, a second fixed portion connected to the lens holder, and a string portion connected to the first fixed portion and the second fixed portion. The lens unit is disposed in the lens holder, and a plurality of electrically independent second metal wires are disposed on the string portion. 
     Another embodiment of the invention provides a camera module, including a lens driving mechanism, a lens unit, and a housing. The lens unit is disposed on the lens driving mechanism, and the housing surrounds the lens driving mechanism. The housing includes a metal member, an insulation layer, and a metal wire. The insulation layer is disposed between the metal member and the metal wire, and the metal wire is electrically connected to the lens driving mechanism. 
     In some embodiments, the thickness of the metal member exceeds the total thickness of the insulation layer and the metal wire. 
     In some embodiments, the thickness of the metal member is 0.10 mm-0.35 mm. 
     In some embodiments, the metal member comprises an inner surface and an outer surface opposite to the inner surface, and the insulation layer and the metal wire are extended from the inner surface to the outer surface. 
     In some embodiments, the camera module further comprises an elastic member, and the metal wire is electrically connected to the elastic member. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG.  1    is a schematic diagram of an electronic device according to an embodiment of the invention; 
         FIG.  2    is an exploded-view diagram of a camera module according to an embodiment of the invention; 
         FIG.  3 A  is a schematic diagram of an elastic member according to an embodiment of the invention; 
         FIG.  3 B  is a cross-sectional view along line A-A in  FIG.  3 A ; 
         FIG.  4 A  is a schematic diagram of an elastic member according to another embodiment of the invention; 
         FIG.  4 B  is a schematic diagram of an elastic member according to another embodiment of the invention; 
         FIG.  4 C  is a schematic diagram of an elastic member according to another embodiment of the invention; 
         FIG.  5    is an schematic diagram of a camera module according to another embodiment of the invention; 
         FIG.  6    is an schematic diagram of the camera module in  FIG.  5   , wherein a portion of the housing is omitted; and 
         FIG.  7    is a cross-sectional view along line B-B in  FIG.  5   . 
     
    
    
     DETAILED DESCRIPTION OF INVENTION 
     The making and using of the embodiments of the camera module are discussed in detail below. It should be appreciated, however, that the embodiments provide many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the embodiments, and do not limit the scope of the disclosure. 
     Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It should be appreciated that each term, which is defined in a commonly used dictionary, should be interpreted as having a meaning conforming to the relative skills and the background or the context of the present disclosure, and should not be interpreted in an idealized or overly formal manner unless defined otherwise. 
     Referring to  FIG.  1   , in an embodiment of the invention, the camera module  10  can be disposed in an electronic device  20  and used to take photographs or record video. The electronic device  20  can be a smartphone or a digital camera, for example. When taking photographs or recording video, the camera module  10  can receive the light and form an image, wherein the image can be transmitted to a processor (not shown) in the electronic device  20 , where post-processing of the image can be performed. 
     As shown in  FIG.  2   , the camera module  10  primarily comprises a housing  100 , a lens driving mechanism  200 , a lens unit  300 , at least one elastic member  400 , an image sensor  500 , and a circuit board  600 . The lens driving mechanism  200  comprises a lens holder  210 , a frame  220 , at least one first electromagnetic driving assembly  230 , at least one second electromagnetic driving assembly  240 , a base  250 , a coil board  260 , a plurality of suspension wires  270 , and a plurality of position detectors  280 . 
     The housing  100  and the base  250  can form a hollow box, and the housing  100  surrounds the lens driving mechanism  200 . Therefore, the lens driving mechanism  200 , the lens unit  300 , and the elastic member  400  can be accommodated in the aforementioned box. The image sensor  500  and the circuit board  600  are disposed on a side of the box, and the housing  100  and the base  250  respectively have an opening O 1  and an opening O 2 . The light can reach the image sensor  500  through the opening O 1 , the lens unit  300 , and the opening O 2  in sequence, so as to form an image on the image sensor  500 . 
     The lens holder  210  has an accommodating space  211  and a concave structure  212 , wherein the accommodating space  211  is formed at the center of the lens holder  210 , and the concave structure  212  is formed on the outer wall of the lens holder  210  and surrounds the accommodating space  211 . The lens unit  300  can be affixed to the lens holder  210  and accommodated in the accommodating space  211 . The first electromagnetic driving assembly  230  can be disposed in the concave structure  212 . 
     The frame  220  has a receiving portion  221  and a plurality of recesses  222 . The lens holder  210  is received in the receiving portion  221 , and the second electromagnetic driving assembly  240  is affixed in the recess  222  and adjacent to the first electromagnetic driving assembly  230 . 
     The lens holder  210  and the lens unit  300  disposed thereon can be driven by the electromagnetic induction between the first electromagnetic driving assembly  230  and the second electromagnetic driving assembly  240  to move relative to the frame  220  along the direction of the Z-axis. For example, in this embodiment, the first electromagnetic driving assembly  230  can be a driving coil surrounding the accommodating space  211  of the lens holder  210 , and the second electromagnetic driving assembly  240  can comprise at least one magnet. 
     When a current flows through the driving coil (the first electromagnetic driving assembly  230 ), electromagnetic induction is generated between the driving coil and the magnet. Thus, the lens holder  210  and the lens unit  300  disposed thereon can be driven to move relative to the frame  220  along the direction of the Z-axis, and the purpose of focus adjustment can be achieved. 
     In some embodiments, the first electromagnetic driving assembly  230  can be a magnet, and the second electromagnetic driving assembly  240  can be a driving coil. 
     Referring to  FIG.  2   , in this embodiment, the camera module  10  comprises two elastic members  400  respectively disposed on opposite sides of the lens holder  210  and the frame  220 , and the lens holder  210  and the frame  220  can be disposed therebetween. The elastic members  400  can connect the lens holder  210  to the housing  100  or the frame  220 . The lens holder  210  can be hung in the receiving portion  221  of the frame  220  by the elastic members  400 , and the range of motion of the lens holder  210  in the direction of the Z-axis can be restricted by the elastic members  400 . 
     As shown in  FIG.  3 A , the elastic member  400  can comprise at least one first fixed portion  401 , at least one second fixed portion  402 , and at least one string portion  403 . The first fixed portion  401  is affixed to the housing  100  or frame  220 , the second fixed portion  402  is affixed to the lens holder  210 , and the string portion  403  is connected to the first fixed portion  401  and the second fixed portion  402 . 
       FIG.  3 B  is a cross-sectional view along line A-A in  FIG.  3 A . Referring to  FIGS.  3 A and  3 B , the elastic member  400  can comprise a metal base  410 , a first insulation layer  420 , and at least one first metal wire  430 , wherein the first insulation layer  420  is disposed between the metal base  410  and the first metal wire  430 . 
     The thickness of the metal base  410  in the direction of the Z-axis exceeds the total thickness of the first insulation layer  420  and the first metal wire  430  in the direction of the Z-axis. For example, the thickness of the metal base  410  can be 0.02 mm-0.35 mm. The metal base  410  and the first metal wire  430  can have the same coefficient of thermal expansion, such that when the elastic member  400  is heated, relative displacement is not generated between the metal base  410  and the first metal wire  430 . 
     It should be noted that, as shown in  FIGS.  3 A and  3 B , the elastic member  400  can comprise a plurality of first metal wires  430 . These first metal wires  430  are separated from each other and electrically independent. These first metal wires  430  can be extended from the first fixed portion  401  to the second fixed portion  402  through the string portion  403 . The ends of each of the first metal wires  430  disposed on the first fixed portion  401  and the second fixed portion  402  are used to electrically connect the other members (such as the suspension wires  270 ). 
     Referring to  FIG.  4 A , in another embodiment, the elastic member  400  can comprise more than two first metal wires  430 . For example, in this embodiment, the elastic member  400  comprises four first metal wires  430 . Referring to  FIG.  4 B , in another embodiment, the electrically independent first metal wires  430  separated from each other can extend through the same string portion  403 . That is, a plurality of electrically independent first metal wires  430  are disposed on each string portion  403 . 
     Referring to  FIG.  4 C , in another embodiment, the elastic member  400  further comprises a second insulation layer  440  and at least one second metal wire  450 . The metal base  410  is disposed between the first insulation layer  420  and the second insulation layer  440 , and the second insulation layer  440  is disposed between the metal base  410  and the second metal wire  450 . 
     Similarly, the thickness of the metal base  410  in the direction of the Z-axis exceeds the total thickness of the second insulation layer  440  and the second metal wire  450  in the direction of the Z-axis. The metal base  410  and the second metal wire  450  can have the same coefficient of thermal expansion, such that when the elastic member  400  is heated, relative displacement is not generated between the metal base  410  and the second metal wire  450 . When a plurality of second metal wires  450  are disposed on the second insulation layer  440 , these second metal wires  450  can be separated from each other and electrically independent, and the arrangement of the second metal wires  450  can be similar to that of the first metal wires  430  in  FIG.  3 A,  3 B , or  4 B. 
     Since the electrically independent first metal wires  430  and the electrically independent second metal wires  450  can be arranged on the elastic member  400 , the elastic member  400  does not need to be divided even when two or more conductive paths are needed. Thus, the integration of the elastic member  400  can be achieved, and the assembly of the elastic member  400  is facilitated. Furthermore, since the integrated elastic member  400  can be achieved, the elastic force applied on the lens holder  210  can be uniform, and the displacement of the lens unit  300  driven by the lens driving mechanism  200  is more accurate. Moreover, the integrated elastic member  400  has a larger fixed area relative to the divided elastic member. Therefore, the separation of the elastic member  400  from the housing  100 , the frame  220  or the lens holder  210  due to collision of the camera module  10  can be avoided. 
     The first metal wires  430  and the second metal wires  450  can be respectively formed on the first insulation layer  420  and the second insulation layer  440  by using a molded interconnect device (MID), for example, by laser direct structuring (LDS), microscopic integrated processing technology (MIPTEC), laser induced metallization (LIM), laser restructuring print (LRP), an aerosol jet process, or a two-shot molding method. In some embodiments, the first metal wires  430  and the second metal wires  450  can be respectively formed on the first insulation layer  420  and the second insulation layer  440  by coating. 
     Referring to  FIG.  2   , the coil board  260  is disposed on the base  250 . When a current flows through the coil board  260 , electromagnetic induction is generated between the coil board  260  and the second electromagnetic driving assembly  240  (or the first electromagnetic driving assembly  230 ). Thus, the lens holder  210  and the frame  220  can be driven to move relative to coil board  260  along the direction of the X-axis and/or the direction of the Y-axis, and the lens unit  300  can be driven to move relative to image sensor  500  along the direction of the X-axis and/or the direction of the Y-axis. The purpose of image stabilization can be achieved. 
     In this embodiment, the camera module  10  comprises four suspension wires  270 . Four suspension wires  270  are respectively disposed on the four corners of the coil board  260  and connect the base  250 , the coil board  260 , and the elastic member  400 . When the lens holder  210  and the lens unit  300  moves along the direction of the X-axis and/or the direction of the Y-axis, the suspension wires  270  can restrict their range of motion. Moreover, since the suspension wires  270  comprise metal (for example, copper or an alloy thereof), the suspension wires  270  can be used as a conductor, for example, the current can flow into the first electromagnetic driving assembly  230  through the base  250 , the suspension wires  270 , and the first metal wires  430  of the metal member  400 . 
     The position detectors  280  are disposed on the base  250 , wherein the position detectors  280  can detect the movement of the second electromagnetic driving assembly  240  to confirm the position of the lens holder  210  and the lens unit  300  in the direction of the X-axis and the direction of the Y-axis. 
     For example, the position detector  280  can be a Hall sensor, a magnetoresistance effect sensor (MR sensor), a giant magnetoresistance effect sensor (GMR sensor), a tunneling magnetoresistance effect sensor (TMR sensor), or a fluxgate sensor. 
     Referring to  FIGS.  5 - 7   , in another embodiment of the invention, the housing  100  comprises a metal member  110 , an insulation layer  120 , and at least one metal wire  130 , wherein the insulation layer  120  is disposed between the metal member  110  and the metal wire  130 . One end of the metal wire  130  is connected to the elastic member  400 , and the metal wire  130  and the insulation layer  120  are extended from the inner surface  101  of the housing  100  to the outer surface  102 . Therefore, the other end of the metal wire  130  can be exposed, and the other electronic members in the electronic device  20  can be electrically connected to the metal wire  130  via the exposed end. 
     The thickness of the metal member  110  exceeds the total thickness of the insulation layer  120  and the metal wire  130 . For example, the thickness of the metal member  110  can be 0.10 mm-0.35 mm. The metal member  110  and the metal wire  130  can have the same coefficient of thermal expansion. 
     Since further circuit boards are not needed for connecting the lens driving mechanism  200  in the camera module  10  and the electronic members in the electronic device  20 , the volume of the camera module  10  can be reduced, and the camera module  10  can be disposed in a miniaturized electronic device  20 . Moreover, the manufacturing process can be simplified, and the heat dissipation efficiency of the camera module  10  can be improved. 
     In summary, a camera module is provided, wherein a plurality of electrically independent metal wires can be arranged on the elastic member of camera module, and the integrated elastic member can be achieved. Furthermore, the housing of the camera module can comprise metal wires for connecting the lens driving mechanism to the external electronic members. 
     Although some embodiments of the present disclosure and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims. For example, it will be readily understood by those skilled in the art that many of the features, functions, processes, and materials described herein may be varied while remaining within the scope of the present disclosure. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, compositions of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. Moreover, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. 
     While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation to encompass all such modifications and similar arrangements.