Patent Publication Number: US-2022236517-A1

Title: Lens driving apparatus, photographing module and electronic device

Description:
RELATED APPLICATIONS 
     The present application is a Continuation of U.S. application Ser. No. 16/515,128, filed on Jul. 18, 2019, which is a Continuation of U.S. application Ser. No. 15/895,134, filed on Feb. 13, 2018, now U.S. Pat. No. 10,401,591 issued on Sep. 3, 2019, which claims priority of Taiwan Application Serial Number 106135763, filed Oct. 18, 2017, which are herein incorporated by reference. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a lens driving apparatus and a photographing module. More particularly, the present disclosure relates to a lens driving apparatus and a photographing module applied to portable electronic devices. 
     Description of Related Art 
     For lens assemblies applied to electronic devices nowadays, a voice coil motor (VCM) is usually served as a lens driving apparatus for auto-focusing. However, the aforementioned lens driving apparatus is usually made up of several essential elements, so that there is a need for a compact size of the lens assembly under a premise without omitting the essential elements. 
     Furthermore, a position sensor is an essential element of the lens driving apparatus. However, the structure accuracy of the position sensor is easily damaged by the high temperature of the welding work during the assembling process thereof, thus the detection sensitivity and the accuracy of the position sensor will be affected. 
     Therefore, how to design a lens driving apparatus with a compact size and a high sensibility under a premise of having a fast focus function has become an important issue in the field of the modern lens driving apparatus. 
     SUMMARY 
     The present disclosure provides a lens driving apparatus including a holder, a metal cover, a carrier, a sensing magnet, a printed circuit board, a position sensor, a coil and at least one driving magnet. The holder is a rectangle and has a central opening and four lateral sides. The metal cover is coupled with the holder and has an opening corresponding to the central opening of the holder. The carrier is assembled to a lens assembly having an optical axis, wherein the carrier is disposed in the metal cover and is movable along a direction parallel to the optical axis. The sensing magnet is coupled with the carrier. The printed circuit board is disposed near to one of the four lateral sides of the holder in an upright form. The position sensor is disposed on the printed circuit board and corresponds to the sensing magnet for detecting a displacement parallel to the optical axis of the sensing magnet. The coil is disposed on an outer surface of the carrier. One of the driving magnets is disposed in the metal cover and corresponds to the coil. Wherein the holder further includes a plurality of first metal terminals and a plurality of second metal terminals, each of the first metal terminals is outwardly extended from the holder along the direction parallel to the optical axis, and each of the second metal terminals is fixedly connected with the printed circuit board. Wherein the first metal terminals are disposed only on one of the lateral sides of the holder, a number of the first metal terminals is at least three, the second metal terminals are disposed on at least one of the other three lateral sides of the holder, and a number of the second metal terminals is at least three. 
     According to another aspect of the present disclosure, a photographing module includes the lens driving apparatus according to the aforementioned aspect and an image sensor for receiving an imaging light from the lens assembly. 
     According to another aspect of the present disclosure, an electronic device includes the photographing module according to the aforementioned aspect. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows: 
         FIG. 1  is a three-dimensional schematic view of a photographing module according to the 1st embodiment of the present disclosure; 
         FIG. 2  is an exploded schematic view of the photographing module according to the 1st embodiment of  FIG. 1 ; 
         FIG. 3  is an exploded schematic view at another angle of a lens driving apparatus according to the 1st embodiment of  FIG. 1 ; 
         FIG. 4  is a schematic view of the first metal terminals of a holder according to the 1st embodiment of  FIG. 1 ; 
         FIG. 5  is a schematic view of the second metal terminals of the holder according to the 1st embodiment of  FIG. 1 ; 
         FIG. 6A  is a three-dimensional schematic view of a plurality of metal plates disposed with the first metal terminals and the second metal terminals; 
         FIG. 6B  is a front schematic view of one of the metal plates of  FIG. 6A ; 
         FIG. 6C  is a back schematic view of the metal plate of  FIG. 6B ; 
         FIG. 6D  is a schematic view of a lower leaf spring and the holder according to the 1st embodiment of  FIG. 1 ; 
         FIG. 7  is an exploded schematic view at another angle of the lens driving apparatus according to the 1st embodiment of  FIG. 1 ; 
         FIG. 8  is a schematic view of an electronic device according to the 2nd embodiment of the present disclosure; 
         FIG. 9  is another schematic view of the electronic device according to the 2nd embodiment of the present disclosure; 
         FIG. 10  is a block diagram of the electronic device according to the 2nd embodiment; 
         FIG. 11  is a schematic view of an electronic device according to the 3rd embodiment of the present disclosure; and 
         FIG. 12  is a schematic view of an electronic device according to the 4th embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     1st Embodiment 
       FIG. 1  is a three-dimensional schematic view of a photographing module  10  according to the 1st embodiment of the present disclosure.  FIG. 2  is an exploded schematic view of the photographing module  10  according to the 1st embodiment of  FIG. 1 .  FIG. 3  is an exploded schematic view at another angle of a lens driving apparatus  100  according to the 1st embodiment of  FIG. 1 . In  FIG. 1 ,  FIG. 2  and  FIG. 3 , the photographing module  10  includes a lens driving apparatus  100  and an image sensor  11 , wherein the image sensor  11  is for receiving an imaging light from a lens assembly  101  of the lens driving apparatus  100 . The lens driving apparatus  100  includes a holder  110 , a metal cover  120 , a carrier  130 , a sensing magnet  140 , a printed circuit board  150 , a position sensor  160 , a coil  170  and at least one driving magnet  180 . 
     The holder  110  is a rectangle and has a central opening  111  and four lateral sides  112 . The metal cover  120  is coupled with the holder  110  and has an opening  121  corresponding to the central opening  111  of the holder  110 . The carrier  130  is assembled to the lens assembly  101 , and the lens assembly  101  has an optical axis X, wherein the carrier  130  is disposed in the metal cover  120  and is movable, but not limited to, along a direction parallel to the optical axis X. The sensing magnet  140  is coupled with the carrier  130 . The printed circuit board  150  is disposed near to one of the four lateral sides  112  of the holder  110  in an upright form, that is, the printed circuit board  150  is disposed on the lateral side  112  of the holder  110  along the direction parallel to the optical axis X. The position sensor  160  is disposed on the printed circuit board  150  and corresponds to the sensing magnet  140  for detecting a displacement parallel to the optical axis X of the sensing magnet  140 , wherein the position sensor  160  can be a Hall sensor or a Hall element. The coil  170  is disposed on an outer surface of the carrier  130 . The driving magnet  180  is disposed in the metal cover  120  and corresponds to the coil  170 . 
     The sensing magnet  140  detected by the position sensor  160  generates the displacement related to the position sensor  160  along to a movement of the carrier  130  so as to change a magnetic field detected by the position sensor  160  accordingly. Accordingly, different voltage signals can be feedbacked so that the carrier  130  can drive the lens assembly  101  to move toward a predetermined position without moving the carrier  130  back to the initial position before moving to the predetermined position. Therefore, the effect of fast focusing can be obtained. The driving magnet  180  is disposed correspondingly and next to the coil  170 , so that the interaction between the driving magnet  180  and the coil  170  can be balanced so as to steadily move the carrier  130  by force as well as steadily drive the lens assembly  101  moving telescopically, simultaneously. 
       FIG. 4  is a schematic view of the first metal terminals  113  of the holder  110  according to the 1st embodiment of  FIG. 1 .  FIG. 5  is a schematic view of the second metal terminals  114  of the holder  110  according to the 1st embodiment of  FIG. 1 . The holder  110  further includes a plurality of first metal terminals  113  and a plurality of second metal terminals  114 , wherein each of the first metal terminals  113  is outwardly extended from the holder  110  along the direction parallel to the optical axis X, and each of the second metal terminals  114  is fixedly connected with the printed circuit board  150 . The first metal terminals  113  are disposed only on one of the lateral sides  112  of the holder  110 , and a number of the first metal terminals  113  is at least three. As shown in  FIG. 3  and  FIG. 4 , the number of the first metal terminals  113  of the 1st embodiment is four. The second metal terminals  114  are disposed on at least one of the others three lateral sides  112  of the holder  110 , and a number of the second metal terminals  114  is at least three. As shown in  FIG. 2  and  FIG. 5 , the number of the second metal terminals  114  of the 1st embodiment is six, and all of the second metal terminals  114  are disposed on the lateral side  112  corresponding to the printed circuit board  150 . Therefore, it is favorable for maintaining a compact size of the lens driving apparatus  100  with a fast focus function by the overall arrangement, and the structure accuracy of the position sensor  160  will not be damaged by the high temperature of the welding work during the assembling process thereof so as to maintain the detection sensitivity and the accuracy of the position sensor  160 . 
     As shown in  FIG. 3  and  FIG. 4 , the lens driving apparatus  100  according to the 1st embodiment of the present disclosure can further include an upper leaf spring  190  and a lower leaf spring  191 . The upper leaf spring  190  is connected to the carrier  130 , and the lower leaf spring  191  is grouped with the upper leaf spring  190  but separately connected to the carrier  130  along the optical axis X, wherein the aforementioned arrangement of the upper leaf spring  190  and the lower leaf spring  191  can provide degrees of freedom along a first direction (that is, the direction along the optical axis X). In detail, the lower leaf spring  191  is disposed on one side of the carrier  130  near to the holder  110 , the lower leaf spring  191  includes a terminal connecting section  192 , and the terminal connecting section  192  is electrically connected with two of the second metal terminals  114 . Therefore, the complexity of the assembling process can be simplified so as to enhance the production efficiency. 
     In the 1st embodiment of the present disclosure, each of the first metal terminals  113  and each of the second metal terminals  114  are inserted in the holder  110  by an insert molding process. Please refer to  FIG. 6A ,  FIG. 6B  and  FIG. 6C .  FIG. 6A  is a three-dimensional schematic view of a plurality of metal plates  12  disposed with the first metal terminals  113  and the second metal terminals  114 .  FIG. 6B  is a front schematic view of one of the metal plates  12  of  FIG. 6A .  FIG. 6C  is a back schematic view of the metal plate  12  of  FIG. 6B . As shown in  FIG. 6A , a plurality of the metal plates can be made of a metal material during the manufacturing process. Furthermore, as shown in  FIG. 6B  and  FIG. 6C , one of the metal plates  12  has a plurality of metal wires after cutting, and a plurality of desired metal terminals can be obtained by a properly cutting process along the cutting marks  12   c , wherein the desired metal terminals include the first metal terminals  113  and the second metal terminals  114 . In the actual manufacturing process, the cut metal plate  12  is buried into the holder  110  before the holder  110  is molded by a plastic injection molding process, and the first metal terminals  113  as well as the second metal terminals  114  are exposed after molding of the holder  110 , that is, the first metal terminals  113  and the second metal terminals  114  are inserted on the holder  110  so as to facilitate being electrically connected to other elements. Therefore, the size of the holder  110  can be effectively reduced and assembling tolerance between the metal terminals (including the first metal terminals  113  and the second metal terminals  114 ) and the holder  110  can be eliminated. The sequence of the aforementioned cutting process as well as the insert molding process can be but not limited to process the cutting process before the insert molding process, or to process the insert molding process and then process the cutting process, so that it is favorable for enhancing the production efficiency. The first metal terminals  113  can be outwardly extended from the holder  110  along the direction parallel to the optical axis X, and the extended pattern of the first metal terminal  113  can be a straight extension or include a turning or a hemispherical extension. The second metal terminals  114  can have an arc shape and extend around the central opening  111  of the holder  110 , so that over-intensive arrangement of the second metal terminals  114  can be prevented so as to reduce short circuits. Furthermore, in addition to the first metal terminals  113  and the second metal terminals  114 , the holder  110  can further include at least one spare metal terminal  115  disposed on one of the lateral sides  112  of the holder  110 , and the spare metal terminal  115  can be served as a spare welded position of the first metal terminals  113  or the second metal terminals  114  so as to corresponding arrange for the adjusted production process. 
     Furthermore, a surface of each of the first metal terminals  113  includes a gilding layer. As shown in  FIG. 4 , in the enlarged schematic view of the first metal terminals  113 , the sprinkle dots on the first metal terminals  113  are presented the gilding layers and the reference numerals of the gilding layers are omitted. Therefore, the quality of signal transmission can be enhanced, and the signal noise of electronic control, such as high frequency noise, can be avoided. 
     At least two of the first metal terminals  113  are electrically connected with at least two of the second metal terminals  114 . Therefore, the manufacturing process of the welding points can be reduced, and the effects of the high temperature during the welding work to the elements can be reduced. 
     In detail,  FIG. 6D  is a schematic view of a lower leaf spring  191  and the holder  110  according to the 1st embodiment of  FIG. 1 . As shown in  FIG. 6B  and  FIG. 6D , in the 1st embodiment, six of the second metal terminals  114  are disposed side by side on the metal plate  12 , and each of the two second metal terminals  114  is electrically connected with the terminal connecting section  192  of the lower leaf spring  191  includes a connecting portion  114   a . As shown in  FIG. 6B , the two second metal terminals  114  including the connecting portions  114   a  are the two of the six second metal terminals  114  being the closest to two sides  12   a ,  12   b  of the metal plate  12 , and the connecting portions  114   a  of the two second metal terminals  114  are for electrically connecting with the terminal connecting section  192 . Therefore, corresponding structural features of the second metal terminals  114  and the lower leaf spring  191  can be obtained (that is, the connecting portion  114   a  and the terminal connecting section  192 ), so that the stability after assembling can be enhanced and the conduction defects are not easy to occur. 
     Moreover, at least two other of the second metal terminals  114  are without the connecting portions  114   a  and integrated with at least two of the first metal terminals  113 , respectively. Therefore, the usage of conductive lines can be reduced so as to simply the welding work process. In detail, in the 1st embodiment, four of the second metal terminals  114  without the connecting portions  114   a  are integrated with four of the first metal terminals  113 , respectively. 
     As shown in  FIG. 2 , the metal cover  120  includes an upper plate  122  and four sidewalls  123 . The opening  121  of the metal cover  120  is disposed on the upper plate  122 . Four sidewalls  123  surround the upper plate  122  and extend along a direction from the upper plate  122  toward the holder  110 , and each of the four sidewalls  123  corresponds to each of the four lateral sides  112  of the holder  110 , wherein at least one of the four sidewalls  123  includes an opening portion  124  being opened for the printed circuit board  150 . Therefore, the position sensor  160  can be assembled last during the assembling process of the lens driving apparatus  100 , so that the accuracy of the assembling process can be enhanced and the dimensional tolerances of the elements can be reduced so as to enhance the detected efficiency of the position sensor  160 . In particular, in the 1st embodiment, only one of the four sidewalls  123  includes the opening portion  124 . Therefore, the appearance of the metal cover  120  can be recognized easily so as to reduce the manufacturing difficulties. Furthermore, the opening portion  124  extends along a direction from the sidewall  123  near to the holder  110  toward the upper plate  122 . Furthermore, an auxiliary frame  129  can be disposed in the metal cover  120 , so that it is favorable for disposing the driving magnet  180  in the metal cover  120 . 
     As shown in  FIG. 3 , the opening portion  124  is disposed opposite to the first metal terminals  113  when the metal cover  120  is coupled with the holder  110 . Therefore, a position for disposing the printed circuit board  150  can be provided, and the first metal terminals  113  can be dodged during the assembling process, so that effects of the welding work related to the first metal terminals  113  to the printed circuit board  150  can be prevented. 
     As shown in  FIG. 2  and  FIG. 3 , a number of the driving magnets  180  can be two, two of the driving magnets  180  are disposed on the two of the sidewalls  123  of the metal cover  120  respectively, and the two lateral sides  112  of the holder  110  corresponding to the two sidewalls  123  are without the first metal terminals  113 . Therefore, the inner space of the lens driving apparatus  100  can be used effectively so as to maintain an overall compact size of the lens driving apparatus  100 . 
     As shown in  FIG. 2 , the opening portion  124  is a notch facing to the holder  110 . The opening portion  124  is a notch instead of a hole can prevent the deformation of the metal cover  120 , so that the demand for size accuracy can be maintained. 
     As shown in  FIG. 5 , the printed circuit board  150  can further include a plurality of conductive joints  151 , and each of the conductive joints is welded to connect with one of the second metal terminals  114 , respectively. Therefore, the welding fixing section can be arranged away from the first metal terminals  113 , so that the arrangements of the printed circuit board  150  and the first metal terminals  113  will not affect each other. 
     As shown in  FIG. 4 , an edge of at least one of the second metal terminals  114  includes a groove structure  114   b . In detail, as the back schematic view of the metal plate  12  of  FIG. 6C , the edge of the second metal terminal  114  including the groove structure  114   b  will have a groove shape after cutting along the cutting marks  12   c  during the production process. Therefore, flows of tin solder materials can be maintained in a controllable range under high temperature. In the 1st embodiment, the edge of each of the six second metal terminals  114  includes the groove structure  114   b . Furthermore, as shown in  FIG. 2  and  FIG. 3 , the second metal terminals  114  including the groove structures  114   b  are disposed on the other lateral side  112  of the holder  110  opposing to the lateral side  112  which the first metal terminals  113  are disposed on. Therefore, it is favorable for processing the welding work so as to reduce the damages of the holder  110  caused by the weld head. 
       FIG. 7  is another exploded schematic view of the lens driving apparatus  100  according to the 1st embodiment of  FIG. 1 . As shown in  FIG. 7 , the lens driving apparatus  100  can further include a compensation element  141 , and the compensation element  141  is coupled with the carrier  130  and disposed opposite to the sensing magnet  140 . In particular, the compensation element  141  can be but not be limited to a non-magnetic metal block for balancing weight. Therefore, the collimation level of the carrier  130  can be maintained so as to reduce the slant. 
     As shown in  FIG. 7 , the carrier  130  includes at least one inserting portion  131  for inserting the sensing magnet  140 , and a hole of the inserting portion  131  can be facing to the holder  110 , which is different from conventional arrangements that the sensing magnet  140  has to be disposed between the coil  170  and the carrier  130 . Therefore, the sensing magnet  140  can be coupled with the carrier  130  more stably and reduce the effects to the winding of the coil  170 . In particular, in the 1st embodiment, the carrier  130  includes two of the inserting portions  131  for inserting the sensing magnet  140  and the compensation element  141 , respectively. Moreover, under an allowable case of the production method, the inserting portions  131  can be facing to the upper plate  122  of the metal cover  120 , but not be limited thereto. 
     As shown in  FIG. 5 , when a central thickness of the position sensor  160  is h, the following condition is satisfied: h&lt;1.0 mm. Therefore, the size of the lens driving apparatus  100  can be reduced and it is favorable for precisely detecting the displacement of the carrier  130  parallel to the optical axis X. 
     2nd Embodiment 
       FIG. 8  is a schematic view of an electronic device  20  according to the 2nd embodiment of the present disclosure.  FIG. 9  is another schematic view of the electronic device  20  according to the 2nd embodiment of the present disclosure. In particular,  FIG. 8  and  FIG. 9  are schematic views of a camera of the electronic device  20 . As shown in  FIG. 8  and  FIG. 9 , the electronic device  20  of the 2nd embodiment is a smart phone. The electronic device  20  includes a photographing module  21  according to the present disclosure, the photographing module  21  includes a lens driving apparatus  24 , a lens assembly  22  and an image sensor  23 , wherein the image sensor  23  is disposed on an image surface (not show) of the lens assembly  22 . Therefore, better image quality is obtained so that the demands for high quality of the image can be achieved. 
     Specifically, the user activates the capturing mode by the user interface  29  of the electronic device  20 , wherein the user interface  29  of the 2nd embodiment can be a touch screen  29   a , a button  29   b , etc. At this moment, the lens assembly  22  collects imaging light on the image sensor  23  and outputs electronic signals associated with images to an image signal processor (ISP)  28 . 
       FIG. 10  is a block diagram of the electronic device  20  according to the 2nd embodiment, in particular, the block diagram of the camera of the electronic device  20 . As shown in  FIGS. 8 to 10 , the electronic device  20  can further include at least one auxiliary optical component  27  and at least one first sensing element  26  in response to the camera specification of the electronic device  20 . The auxiliary optical component  27  can be a flash module for compensating color temperature, an infrared distance measurement component, a laser focus module, etc. The first sensing element  26  can have functions for sensing physical momentum and kinetic energies, such as an accelerator, a gyroscope, and a hall effect element, so as to sense shaking or jitters applied by hands of the user or external environments, thus the lens driving apparatus  24  disposed on the photographing module  21  can function to obtain great image quality and facilitate the electronic device  20  according to the present disclosure to have a capturing function with multiple modes, such as taking optimized selfies, high dynamic range (HDR) with a low light source, 4K resolution recording, etc. Furthermore, the user can visually see the captured image of the camera through the touch screen  29   a  and manually operate the view finding range on the touch screen  29   a  to achieve the auto focus function of what you see is what you get. 
     Furthermore, as shown in  FIG. 9 , the photographing module  21 , the first sensing element  26  and the auxiliary optical component  27  can be disposed on a flexible printed circuit board (FPC)  77  and electrically connected with an image signal processor  28  by a connector  78  so as to perform a capturing process. Because the current electronic devices have a tendency of being light and thin, the way of disposing the photographing module  21  and related elements on the flexible printed circuit board and then integrating the circuit into the main board of the electronic device via the connector can satisfy the mechanical design of the limited space inside the electronic device and the layout requirements and obtain more margins, so that the auto focus function of the photographing module  21  can be controlled more flexibly via the touch screen of the electronic device. In the 2nd embodiment, the electronic device  20  includes a plurality of first sensing elements  26  and a plurality of auxiliary optical components  27 , the first sensing elements  26  and the auxiliary optical components  27  are disposed on the flexible printed circuit board  77  and at least one other flexible printed circuit board (reference number is not shown) and electrically connected with the associated elements, such as the image signal processor  28 , by corresponding connectors so as to perform a capturing process. In other embodiments (not shown), the sensing component and the auxiliary optical component can also be disposed on the main board of the electronic device in other forms according to requirements of the mechanical design and the circuit layout. 
     Moreover, the electronic device  20  can further include, but not be limited to, a wireless communication unit, a control unit, a storage unit, a random-access memory (RAM), a read-only memory, or the combination thereof. 
     3rd Embodiment 
       FIG. 11  is a schematic view of an electronic device  30  according to the 3rd embodiment of the present disclosure. The electronic device  30  of the 3rd embodiment is a tablet, and the electronic device  30  includes a photographing module  31  according the present disclosure. 
     4th Embodiment 
       FIG. 12  is a schematic view of an electronic device  40  according to the 4th embodiment of the present disclosure. The electronic device  40  of the 4th embodiment is a wearable device, and the electronic device  40  includes a photographing module  41  according to the present disclosure. 
     The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. It is to be noted that Tables show different data of the different embodiments; however, the data of the different embodiments are obtained from experiments. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical applications, to thereby enable others skilled in the art to best utilize the disclosure and various embodiments with various modifications as are suited to the particular use contemplated. The embodiments depicted above and the appended drawings are exemplary and are not intended to be exhaustive or to limit the scope of the present disclosure to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings.