Patent Publication Number: US-2022229348-A1

Title: Optical element driving mechanism

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     100011 This application is a continuation of application Ser. No. 17/484,572, filed on Sep. 24, 2021, which is a continuation of application Ser. No. 16/814,208, filed on Mar. 10, 2020, which is a continuation of application Ser. No. 16/381,273, filed on Apr. 11, 2019, which is a continuation of application Ser. No. 15/642,487, filed on Jul. 6, 2017, which claims the benefit of U.S. Provisional Application No. 62/361,223, filed Jul. 12, 2016, and claims priority of China Patent Application No. 201710343399.7, filed May 16, 2017, the entirety of which are incorporated by reference herein. 
    
    
     BACKGROUND 
     Technical Field 
     The disclosure relates to a lens driving module, and in particular to a lens driving module with a plurality of electromagnetic driving assemblies at different positions in height. 
     Description of the Related Art 
     As technology develops, many electronic devices nowadays (such as tablet computers or smart phones) are equipped with lens modules and have a camera or video function. When the user of an electronic device equipped with a lens module shakes the device, images captured by the camera via the lens module may turn out blurry. Since the requirements for image quality have increased, it has become more and more important to develop a vibration-proof lens module. 
     BRIEF SUMMARY 
     Some embodiments of the disclosure provide a lens driving module, including: a reflecting element, a base, a frame, a holder, an optical lens, a first electromagnetic driving assembly, and a second electromagnetic driving assembly. The frame is connected to the base. The holder holds the optical lens and is movably connected to the base. The reflecting element reflects light from the outside along a light incident direction to pass through the optical lens along a first direction, wherein the light incident direction is substantially perpendicular to the first direction. The first and second electromagnetic driving assemblies are configured to force the holder and the optical lens to move relative to the base, wherein the first and second electromagnetic driving assemblies are situated in different positions in the light incident direction. 
     In an embodiment, the first electromagnetic driving assembly forces the holder and the optical lens to move in the first direction, and the second electromagnetic driving assembly forces the holder and the optical lens to move in a second direction, wherein the first direction is substantially perpendicular to the second direction. 
     In an embodiment, a distance is formed between the first electromagnetic driving assembly and the second electromagnetic driving assembly in the light incident direction, and the distance is shorter than the diameter of the optical lens. 
     In an embodiment, the first electromagnetic driving assembly is disposed on the base and the holder, and the second electromagnetic driving assembly is disposed on the frame and the holder. 
     In an embodiment, the first electromagnetic driving assembly has a first drive coil, and the second electromagnetic driving assembly has a second drive coil, and wherein the first drive coil and the second drive coil have elongated structures extending in the second direction and the first direction respectively, and the first direction is substantially perpendicular to the second direction. 
     In an embodiment, the optical lens has a plane perpendicular to the light incident direction. 
     In an embodiment, the lens driving module further includes a rolling element movably connected to the holder and the base. 
     In an embodiment, the lens driving module further includes two recesses respectively formed on the base and the holder, and accommodated the rolling element. 
     In an embodiment, the recesses have elongated structures respectively extending along the first direction and second direction, wherein the first direction is substantially perpendicular to the second direction. 
     In an embodiment, the lens driving module further includes an elastic element movably connected to the holder and the base. 
     In an embodiment, the holder has a C-shaped structure, and two ends of the C-shaped structure respectively have an angle plane inclining corresponding to the light incident direction. 
     In an embodiment, three separated contact regions are formed between the holder and the optical lens. 
     In an embodiment, the lens driving module further includes a circuit board having an opening, wherein the base has a recessed structure received the opening. 
     In an embodiment, the lens driving module further includes a plurality of circuit boards connected to the base and separated from each other, wherein a portion of the holder is received a space between the plurality of circuit boards. 
     In an embodiment, the lens driving module further includes a conductor embedded in the base and electrically connected to the plurality of circuit boards. 
     Some embodiments of the disclosure provide a lens driving module, including: a reflecting element, a base, a frame, a holder, an optical lens, a first electromagnetic driving assembly, and a second electromagnetic driving assembly. The frame is connected to the base, and the holder holds the optical lens and movably connects to the base. The reflecting element reflects light from the outside along a light incident direction to an optical lens along a first direction, wherein the light incident direction is substantially perpendicular to the first direction. The first and second electromagnetic driving assemblies are configured to force the holder and the optical lens to move relative to the base, wherein the first electromagnetic driving assembly has a first drive coil, the second electromagnetic driving assembly has a second drive coil, the first drive coil and the second drive coil have elongated structures extending in a second direction and the first direction respectively, and the first direction is substantially perpendicular to the second direction. 
     In an embodiment, the first electromagnetic driving assembly and the second electromagnetic driving assembly are situated in different heights in the light incident direction. As viewed along the light incident direction, the first electromagnetic driving assembly and the second electromagnetic driving assembly partially overlap. 
     In an embodiment, the lens driving module further includes a first aligning element and a second aligning element. The first aligning element is disposed on a top surface of the base, and the second aligning element is disposed on a bottom surface of the holder. 
     In an embodiment, the first aligning element is a permanent magnet, and the second aligning element is a Hall effect sensor. In an embodiment, the first aligning element is a Hall effect sensor, and the second aligning element is a permanent magnet. 
     Some embodiments of the disclosure provide a lens driving module, including: a reflecting element, a base, a frame, a holder, an optical lens, a first electromagnetic driving assembly, a second electromagnetic driving assembly, and a rolling element. The frame is connected to the base. The holder holds the optical lens and is movably connected to the base. Two recesses respectively formed on the base and the holder, and the rolling element is received in the recess. The reflecting element reflects light from the outside along a light incident direction to pass through the optical lens along a first direction, wherein the light incident direction is substantially perpendicular to the first direction. The first and second electromagnetic driving assemblies are configured to force the holder and the optical lens to move relative to the base, wherein the first and second electromagnetic driving assemblies are situated in different positions in the light incident direction. The rolling element is movably connected to the holder and the base. 
     Some embodiments of the disclosure provide an optical member driving mechanism, including: a movable portion, a fixed portion, a driving assembly, and a guiding assembly. The movable portion is configured to connect an optical lens with an optical axis. The fixed portion includes a base, wherein the base has a base surface. The movable portion is movable relative to the fixed portion, and the base surface faces the movable portion and is parallel to the optical axis. The driving assembly is configured to force the movable portion to move relative to the fixed portion. The movable portion is movable relative to the fixed portion via the guiding assembly. When viewed in a first direction that is perpendicular to the base surface, the optical axis does not overlap the driving assembly, and the optical axis does not overlap the guiding assembly. 
     Some embodiments of the disclosure provide a lens driving module, including: a base, a frame fixedly connected to the base, and a holder configured to connect an optical lens. The holder is movable relative to the base. The lens driving module also includes a reflecting element configured to reflect light from a light incident direction to a first direction. The first direction is perpendicular to the light incident direction, and the first direction is parallel to an optical axis of the optical lens. The lens driving module further includes a first electromagnetic driving assembly configured to force the holder to move along the first direction relative to the base. The lens driving module has multiple recesses formed on the base and arranged along the first direction. The lens driving module includes multiple the rolling elements disposed on the recesses, and the holder is moved relative to the base via the rolling elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure 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 perspective view illustrating a lens driving module in an embodiment of the present disclosure. 
         FIG. 2  is an explosion diagram illustrating a lens unit of the lens driving module in  FIG. 1 . 
         FIG. 3  is a schematic perspective view illustrating the lens unit in  FIG. 2  after assembly. 
         FIG. 4  is a cross-sectional view of the lens unit along the line A-A in  FIG. 3 . 
         FIG. 5  is a schematic perspective view illustrating a first unit U 1 , a second unit U 2 , and a rolling element B. 
         FIG. 6  is a bottom view illustrating a base and a circuit board in  FIG. 5 . 
         FIG. 7  is a schematic diagram illustrating an optical lens and a holder in another embodiment of the disclosure. 
         FIG. 8  is an explosion diagram illustrating a lens unit in another embodiment of the disclosure. 
         FIG. 9  is a schematic perspective view illustrating the lens unit in  FIG. 8  after assembly. 
         FIG. 10  is a bottom view illustrating a base  10 ′, circuit boards F 1  and F 2 , and a rolling element B in  FIG. 8  after assembly. 
         FIG. 11  is an explosion diagram illustrating a lens unit in another embodiment of the disclosure. 
         FIG. 12  is a cross-sectional view illustrating the lens unit in  FIG. 11  after assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The lens driving modules of some embodiments of the present disclosure are described in the following description. However, it should be appreciated that in the following detailed description of some embodiments of the disclosure provides various invention concepts which may be performed in widely various specific background. The specific embodiments disclosed are provided merely to clearly describe the invention in some specific methods without limiting the scope of the invention. 
     Unless defined otherwise, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It should be appreciated that, in each case, the term, which is defined in a commonly used dictionary, should be interpreted as having a meaning that conforms to the relative skills of the present disclosure and the background or the context of the present disclosure, and should not be interpreted in an idealized or overly formal manner unless so defined in the present disclosure. 
       FIG. 1  is a schematic perspective view illustrating a lens driving module  1  in an embodiment of the present disclosure. The lens driving module  1  may be disposed inside an electronic device (for example, a camera, a tablet computer, or a cell phone). The lens driving module  1  includes a lens unit UL and a reflecting element P. When a light from outside along a light incident direction Q (Z-axis) enter the lens driving module  1 , the light is reflected from the light incident direction Q to pass through an optical lens L of the lens unit UL along a first direction D 1  (X-axis) by the reflecting element P (for example, a prism or a reflecting minor) of the lens driving module  1 . Therefore, the light may pass through the optical lens L to a photosensitive element (not shown) in the electronic device in order to capture images. 
     It should be noted that an optical axis (substantially parallel to X-axis) of the optical lens L is substantially perpendicular to the light incident direction Q. Therefore, each element of the lens unit UL may be disposed along a direction parallel to X-axis, and the thickness of the electronic device in Z-axis direction may be significantly reduced to achieve miniaturization. 
     The optical lens L of the lens unit UL may move corresponding to the photosensitive element of the electronic device. Therefore, a focal distance of the optical lens L may be properly adjusted to achieve efficacy of auto-focusing (AF). Thus, image quality may be increased. The structure of the lens driving unit UL is described in detail as follows. 
     Referring to  FIGS. 2 and 3 ,  FIG. 2  is an explosion diagram illustrating the lens unit UL in  FIG. 1 , and  FIG. 3  is a schematic perspective view illustrating the lens unit UL in  FIG. 2  after assembly. The lens unit UL includes a first unit U 1 , a second unit U 2 , and a plurality of rolling elements B (connecting pieces), wherein the rolling elements B are connected to the first and second units U 1  and U 2 . The first and second units U 1  and U 2  mainly include: a base  10 , a circuit board F, a frame  20 , a holder  30 , a first electromagnetic driving assembly MC 1 , a second electromagnetic driving assembly MC 2 , and an optical lens L. The frame  20  is disposed over the base  10  and fixed with each other. The holder  30  is also disposed over the base  10  and connected to each other by the rolling elements B in order to hold the optical lens L. As shown in  FIGS. 2-3 , the first electromagnetic driving assembly MCI includes a plurality of first drive coils Cl and a plurality of first magnetic elements M 1  (for example, magnets) respectively disposed on the base  10  and the holder  30 , wherein a driving signal (for example, a current) may be applied to the first drive coil C 1  by an external power source in order to force the holder  30  and the optical lens L to move relative to the frame  20  and the base  10 . In addition, the second electromagnetic driving assembly MC 2  includes a plurality of second drive coil C 2  and a plurality of second magnetic elements M 2  (for example, magnets) respectively disposed on the frame  20  and the holder  30 , wherein a driving signal may be applied to the second drive coil C 2  by an external power source in order to force the holder  30  and the optical lens L to move relative to the frame  20  and the base  10 . By forcing the optical lens L to move relative to the frame  20  and the base  10  through the first and second electromagnetic driving assemblies MC 1  and MC 2 , the efficacy of optical image stabilization (OIS) may be achieved. 
     Referring to  FIGS. 3-4 , the structures of the first and second electromagnetic driving assemblies MC 1  and MC 2  are shown in detail, wherein  FIG. 4  is a cross-sectional view along the line A-A in  FIG. 3 . The first and second electromagnetic driving assemblies MC 1  and MC 2  are respectively disposed (or embedded) on the bottom and top surfaces of the holder  30 . The first and second drive coils C 1  and C 2  are respectively disposed on the base  10  and the frame  20 . The first and second magnetic elements M 1  and M 2  are correspondingly placed facing the first and second drive coils C 1  and C 2  in order to form the first and second electromagnetic driving assemblies MC 1  and MC 2  capable of forcing the holder  30  and the optical lens L to move. In the embodiments, at least each one of the first and second electromagnetic driving assemblies MC 1  and MC 2  are disposed on the left and right sides of the optical lens L (shown in  FIG. 4 ), so that the holder  30  and the optical lens L can stably move relative to the base  10  and the frame  20 . 
     It should be appreciated that the configurations and positions of the first drive coil C 1 , the first magnetic element Ml, the second drive coil C 2 , and the second magnetic element M 2  are not limited to the aforementioned embodiments. For example, in some other embodiments, the first and second magnetic elements M 1  and M 2  may respectively be disposed on the base  10  and the frame  20 , and the first and second drive coils C 1  and C 2  may be disposed on the holder  30 . 
     In addition, as shown in  FIG. 4 , the holder  30  has a C-shaped structure, and the two ends of the C-shaped structure respectively has an angled plane  31  (inclining relative to Z-axis). The angled planes  31  may be conducive to assembling, connecting or attaching the holder  30  and other elements. 
     The moving mode of the optical lens L is described in detail as follows. When an appropriate driving signal is applied to the first electromagnetic driving assembly MC 1 , the first electromagnetic driving assembly MC 1  can force the holder  30  and the optical lens L to move along the first direction D 1  (substantially parallel to X-axis) relative to the base  10  and the frame  20 . Similarly, when an appropriate driving signal is applied to the second electromagnetic driving assembly MC 2 , the second electromagnetic driving assembly MC 2  can force the holder  30  and the optical lens L to move in the second direction D 2  (substantially parallel to Y-axis) relative to the base  10  and the frame  20 . Accordingly, the holder  30  and the optical lens L may move towards two different directions, the first and second directions D 1  and D 2 , on the xy-plane. Therefore, the lens driving module  1  can have the better efficacy of vibration compensation. Furthermore, in the Z-axis direction (the light incident direction Q), by placing the first and second electromagnetic driving assemblies MC 1  and MC 2  at different heights, the problem of electromagnetic interference due to being on the same plane may be reduced or avoided. Moreover, the magnetic driving forces generated by the first and second electromagnetic driving assemblies MC 1  and MC 2  in the lens unit UL for driving the optical lens L can be effectively increased. In addition, because a distance N between the first and second electromagnetic driving assemblies MC 1  and MC 2  in Z-axis direction is shorter than a diameter of the optical lens L, the height of the lens unit UL in Z-axis direction may be reduced. Thus, the overall volume of the lens driving module may be reduced. 
     As shown in  FIG. 5 , it should be noted that a plurality of recesses RI are formed on the top surface of the base  10 , and a plurality of recesses RII are formed on the bottom surface  301  of the holder  30 . The plurality of recesses RI and RII correspondingly accommodate a portion of the plurality of the rolling elements B and may be used to lead the rolling elements B to roll. In the embodiment, the recesses RI and RII have elongated structures. Macro-axes of the recesses RI extend in the first direction D 1  (substantially parallel to X-axis), and macro-axes of the recesses RII extend in the second direction D 2  (substantially parallel to Y-axis), wherein the first direction D 1  is substantially perpendicular to the second direction D 2 . Accordingly, the rolling elements B can successfully roll along the first and second directions D 1  and D 2  on the xy-plane to lead the optical lens L and the holder  30  to move in the first and second directions D 1  and D 2  relative to the base  10  and the frame  20 . Therefore, the lens unit UL may have the efficacy of vibration compensation in at least two dimensions. In addition, the first drive coil C 1  and the second drive coil C 2  also have elongated structures extending towards the second and first directions D 2  and D 1 , respectively. 
     Referring to  FIGS. 4 and 5 , the lens unit UL further includes two pairs of first and second aligning elements H 1  and H 2 . The first and second aligning elements H 1  and H 2  are respectively disposed on the top surface of the base  10  and the bottom surface  301  of the holder  30 . In some embodiments, the first aligning element H 1  may be one of a permanent magnet and a Hall effect sensor, and the second aligning element H 2  is another one of the two aforementioned. The Hall effect sensor can determine the position of the permanent magnet by detecting the change of the magnetic field of the permanent magnet. In this way, the position deviation of the holder  30  and the optical lens L caused by vibration may be detected and compensated for. 
     Referring to  FIGS. 5 and 6 ,  FIG. 6  is a bottom view illustrating the base  10  and the circuit board F. The circuit board F is connected to the base  10 , and an opening F 101  is formed in the circuit board F. A recessed structure  101  (shown in  FIG. 5 ) is formed on the top surface of the base  10 . The recessed structure  101  is embedded in the opening F 101 . Accordingly, when assembling the first and second units U 1  and U 2 , the thickness of the circuit board F in Z-axis (the light incident direction Q) may be reduced to effectively save space. 
       FIG. 7  is a schematic diagram illustrating an optical lens L′ and a holder  30 ′ in another embodiment of the disclosure. As shown in the figure, the difference between the optical lens L′ and the optical lens L in  FIG. 2  is that the optical lens L′ has two planes L′ 101  and L′ 102  that are substantially perpendicular to Z-axis (the light incident direction Q). In comparison with the optical lens L, the optical lens L′ has a thinner thickness in Z-axis direction. Thus, the volume of the lens unit can be reduced. Furthermore, the holder  30 ′ and the optical lens L′ only have three contact regions CA 1 , CA 2 , and CA 3  separated from each other. In this way, the contact area between the optical lens L′ and the holder  30 ′ can be reduced in order to increase the precision and convenience of assembly. 
       FIGS. 8 to 10  are schematic diagrams of a lens unit UL 2  in another embodiment of the present disclosure. The lens unit UL 2  includes a first unit U 3 , a second unit U 4 , and a plurality of rolling elements B. The second unit U 4  is disposed over the first unit U 3  and connected to the first unit U 3  through the rolling elements B. The second unit U 4  includes four first magnetic elements M 1 , and the other elements of the second unit U 4  are the same or corresponding to those of the aforementioned second unit U 2  (shown in  FIG. 2 ). There is just a slight difference in appearance. Therefore, the other elements of the second unit U 4  are not described in detail here again. 
     As shown in  FIGS. 8 and 9 , the main difference between the first unit U 3  in this embodiment and the aforementioned first unit U 1  (shown in  FIG. 2 ) is that the first unit U 3  includes four first drive coils Cl and two separated circuit boards F 1  and F 2 , wherein the first drive coils Cl and the circuit boards F 1  and F 2  are disposed over the base  10 ′ in the manner of substantially symmetrical to a central axis (Z-axis direction) of the lens unit UL 2 . The circuit boards F 1  and F 2  are respectively connected to two of the first drive coils Cl. The four first magnetic elements M 1  are correspondingly placed facing the first drive coils Cl in order to form the first electromagnetic driving assembly MC 1 . Thus, the holder  30  and the optical lens L may be forced to move relative to the base  10 ′ and the frame  20 . 
       FIG. 10  is a bottom view of the base  10 ′, the circuit boards F 1  and F 2 , and the rolling elements B in  FIG. 8  after assembly, wherein the base  10 ′ is illustrated by dotted lines in order to show that it is a perspective element. A plurality of conductors (such as metal sheets) E 1 -E 4  are embedded in the base  10 ′ by the methods, for example, insert molding or a 3D molded interconnect device technique. The conductors E 1 -E 4  are electrically connected to the circuit boards F 1  and F 2 . An external power source applies driving signals to the circuit boards F 1  and F 2  and the first drive coil C 1  through the conductor E 1 -E 4  in order to force the optical lens L to move by the electromagnetic driving assembly MC 1 . As shown in  FIG. 8 , it should be noted that the two separated circuit boards F 1  and F 2  are respectively disposed on the left and right sides of the optical lens L and are separated by a distance. Therefore, after assembling the first and second units U 3  and U 4 , a portion of the bottom of the holder  30 ″ is accommodated between a space between the circuit boards F 1  and F 2 . Thus, the overall thickness of the lens unit UL 2  in Z-axis direction can be reduced in order to save space. 
       FIG. 11  is an exploded diagram illustrating a lens unit UL 3  in another embodiment of the present disclosure.  FIG. 12  is a cross-sectional view of the lens unit UL 3 . As shown in  FIGS. 11 and 12 , the main difference between the lens unit UL 3  in the embodiment and the aforementioned lens unit UL 2  (shown in  FIG. 8 ) is that the shape of a holder  30 ″ in a first unit U 6  of the lens unit UL 3  is different from that of the aforementioned holder  30 . The lens unit UL 3  includes a plurality of leaf springs SF and a plurality of elastic elements S (connection pieces), wherein the leaf springs SF are disposed on the top surface of the holder  30 ″, and the two ends of each of the elastic elements S are respectively connected to the leaf springs SF and the base  10 ′. Thus, the holder  30 ″ and the optical lens L are movably connected to the base  10 ′. Moreover, the second magnetic elements M 2  are disposed over the frame  20 , and the second drive coils C 2  are disposed on the top surface of the holder  30 ″ and connected to the leaf springs SF (shown in  FIG. 12 ). 
     The holder  30 ″ has a substantially circular hollow structure which can be used to stably hold the optical lens L. Four elastic elements S (for example, flexible metal wires) are respectively disposed at the corners of the leaf spring SF (for example, a metal-containing sheet spring) to connect the holder  30 ″ and the base  10 ′. The holder  30 ″ and the optical lens L may move relative to the base  10 ′ through the electromagnetic driving assemblies MCI (including the magnetic elements M 1  and the drive coils C 1 ) and MC 2  (including the magnetic elements M 2  and the drive coils C 2 ) in order to achieve the functions of auto-focusing (AF) and optical image stabilization (OIS). 
     In summary, the embodiments provide a lens driving module which may be disposed in an electronic device. The lens driving module includes a lens unit, a reflecting element, and at least one connecting piece, wherein the lens unit includes an optical lens, a holder, a frame, a base, a first electromagnetic driving assembly, and a second electromagnetic driving assembly. The reflecting element is used for reflecting light from the outside to pass through the lens unit to a photosensitive element in the electronic device in order to capture images. The frame is fixed on the base. The connecting piece may be a rolling element or a flexible elastic element which is connected to the holder and the base. The first electromagnetic driving assembly is disposed on the base and the holder. The second electromagnetic driving assembly is disposed on the frame and the holder. The first and second electromagnetic driving assemblies force the holder and the optical lens to move relative to the base and the frame. The first and second electromagnetic driving assemblies are situated at different positions in a light incident direction such that the interference between two electromagnetic driving assemblies in the lens unit may be reduced. The magnetic driving force can be thereby effectively increased. Moreover, the holder and the optical lens may be led to move relative to the base and the frame along a plurality of directions that are perpendicular to the light incident direction in order to achieve good optical focusing or compensation. Furthermore, by not overlapping the optical lens with the circuit boards in the base, the overall volume of the lens driving module can be reduced. 
     It should be understood that there is no relationship in a sequence between the ordinal numbers in the present specification and claims, such as “first”, “second” etc. These terms are only used to distinguish two different elements with the same name. 
     The aforementioned embodiments are adequately described in detail for those skilled in the art to perform the device of the present disclosure. It should be understood that those skilled in the art may make various changes and modifications to the invention without departing from the spirit and scope of the present disclosure. Therefore, the scope of the present disclosure is defined according to the following claims.