Patent Publication Number: US-2022221686-A1

Title: Lens driving apparatus

Description:
RELATED APPLICATIONS 
     The present application is a continuation of the application Ser. No. 16/720,086, filed Dec. 19, 2019, which is a continuation of the application Ser. No. 16/194,424, filed Nov. 19, 2018, now U.S. Pat. No. 10,545,310 issued on Jan. 28, 2020, which is a continuation of the application Ser. No. 15/686,347, filed Aug. 25, 2017, now U.S. Pat. No. 10,162,150 issued on Dec. 25, 2018, which is a continuation of the application Ser. No. 14/476,929, filed Sep. 4, 2014, now U.S. Pat. No. 9,778,436 issued on Oct. 3, 2017, which claims priority to Taiwan Application Serial Number 103213501, filed Jul. 30, 2014, which are herein incorporated by reference. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a lens driving apparatus. More particularly, the present disclosure relates to a lens driving apparatus applicable to mobile terminals. 
     Description of Related Art 
     In general, the voice-coil motor (VCM) cooperated to an open-loop controlling method is applied to the lens for providing an auto-focusing. However, the conventional VCM cannot provide feedback signal to the actuator during moving the lens, so that the present position of the lens cannot be notified immediately. Hence, the lens should be moved to the original position before focusing every time, that is, the focusing time would be lengthened and the operation would not be fluency. 
     SUMMARY 
     According to one aspect of the present disclosure, a lens driving apparatus includes a holder, a cover, a carrier, at least one first magnet, a coil, a spring, a spacer, at least two second magnets and a hall sensor. The holder includes an opening hole. The cover is made of metal material and coupled to one side of the holder. The carrier is movably disposed in the cover, and for coupling to a lens. The first magnet is connected to an inner side of the cover. The coil is wound around an outer side of the carrier, and adjacent to the first magnet. The spring is coupled to the carrier. The spacer is located between the cover and the first magnet. The second magnets are disposed on one end of the carrier which is toward the holder. The hall sensor is for detecting a magnetic field of any one of the second magnets, wherein the magnetic field is varied according to a relative displacement between the hall sensor and the second magnet which is detected. 
     According to another aspect of the present disclosure, a lens driving apparatus includes a holder, a cover, a carrier, at least one first magnet, a coil, a spring, at least two second magnets, a hall sensor and a circuit board. The holder includes an opening hole. The cover is made of metal material and coupled to one side of the holder. The carrier is movably disposed in the cover, and for coupling to a lens. The first magnet is connected to an inner side of the cover. The coil is wound around an outer side of the carrier, and adjacent to the first magnet. The spring is coupled to the carrier. The second magnets are disposed on one end of the carrier which is toward the holder. The hall sensor is for detecting a magnetic field of any one of the second magnets. The hall sensor and an imaging element are connected to the circuit board, and the imaging element is for receiving an imaging light of the lens. When a component parallel to an optical axis of the lens of a distance between the hall sensor and the second magnet which is detected is d1, and a component orthogonal to the optical axis of the lens of the distance between the hall sensor and the second magnet which is detected is d2, the following condition is satisfied: 
     d1&gt;d2. 
    
    
     
       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  shows an external schematic view of a lens driving apparatus according to the 1st embodiment of the present disclosure; 
         FIG. 2  shows an explode view of the lens driving apparatus according to the 1st embodiment of the present disclosure; 
         FIG. 3A  shows a schematic view of the cover, the first magnets, the second magnets and the hall sensor of the lens driving apparatus according to the 1st embodiment; 
         FIG. 3B  shows a bottom view of the cover, the first magnets, the second magnets and the hall sensor of the lens driving apparatus according to the 1st embodiment; 
         FIG. 4A  shows an enlarged view of the first spring member of the lens driving apparatus of the 1st embodiment; 
         FIG. 4B  shows an enlarged view of the second spring member of the lens driving apparatus according to the 1st embodiment; 
         FIG. 5A  shows a schematic view of the second magnets and the hall sensor of the lens driving apparatus according to the 2nd embodiment; 
         FIG. 5B  shows a bottom view of the second magnets and the hall sensor of the lens driving apparatus according to the 2nd embodiment; 
         FIG. 6A  shows a schematic view of the second magnets and the hall sensor of the lens driving apparatus according to the 3rd embodiment; 
         FIG. 6B  shows a bottom view of the second magnets and the hall sensor of the lens driving apparatus according to the 3rd embodiment; 
         FIG. 7A  shows a schematic view of the second magnets and the hall sensor of the lens driving apparatus according to the 4th embodiment; 
         FIG. 7B  shows a bottom view of the second magnets and the hall sensor of the lens driving apparatus according to the 4th embodiment; and 
         FIG. 7C  shows the carrier and the second magnets of the lens driving apparatus according to the 4th embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an external schematic view of a lens driving apparatus according to the 1st embodiment of the present disclosure.  FIG. 2  shows an explode view of the lens driving apparatus according to the 1st embodiment of the present disclosure. The lens driving apparatus includes a holder  100 , a cover  200 , a carrier  300 , at least one first magnet  410 , a coil  500 , a spring  600 , at least two second magnets  420 , a spacer  220  and a hall sensor  700 . In  FIG. 1 , the components of the lens driving apparatus can be covered by the cover  200 , and the cover  200  is coupled to the holder  100 , so that the lens driving apparatus can be applied to the electronic product, and the components can be separated from the external environment. 
     In detail, the holder  100  includes an opening hole  101 , the cover  200  is made of metal material and coupled to one side of the holder  100 . In  FIG. 2 , the cover  200  is cube-shaped, and a side wall of the cover  200  is composed from four wall members into closed-shape. One end of the cover  200  is an opening end, the other end of the cover  200  is an end wall  210  which is connected to the side wall and has an opening hole  211  corresponding to the opening hole  101  of the holder  100 . Therefore, the lens  800  can be movable through the opening hole  101  of the holder  100  and the opening hole  211  of the cover  200 . 
     The carrier  300  is movably disposed in the cover  200 , and for coupling to a lens  800 . Therefore, the lens  800  can be movable with the carrier  300 . 
     The first magnet  410  is connected to an inner side of the cover  200 . According to the 1st embodiment of  FIG. 2 , the number of the first magnet  410  is 4.  FIG. 3A  shows a schematic view of the cover  200 , the first magnets  410 , the second magnets  420  and the hall sensor  700  of the lens driving apparatus according to the 1st embodiment.  FIG. 3B  shows a bottom view of the cover  200 , the first magnets  410 , the second magnets  420  and the hall sensor  700  of the lens driving apparatus according to the 1st embodiment. In  FIGS. 3A and 3B , each of the first magnets  410  is a trapezoid-shaped cylinder, precisely, is an isosceles trapezoid-shaped cylinder. That is, each of the first magnets  410  has an upper surface  411 , a bottom surface  412  and two side surfaces  413 , wherein the upper surface  411  and the bottom surface  412  are unequal length but parallel to each other, and the two side surfaces  413  are equal length, and connected to the upper surface  411  and the bottom surface  412 , respectively. In  FIG. 3B , the side surfaces  413  of each of the first magnets  410  are connected to two inner surfaces which are adjacent to each other of the inner side of the cover  200 , so that the first magnets  410  are stably and equally disposed in the cover  200 . 
     The cover  200  is for surrounding the components of the lens driving apparatus, and each component has different shape and size. However, each of the components should be securely fixed and positioned relative to the cover  200  or the other components. Therefore, the lens driving apparatus includes the spacer  220  located between the cover  200  and the first magnets  410 . The spacer  220  can be connected to the inner side of the cover  200  for coupling or connecting to other components. It is favorable for the arrangement of the component which is covered and surrounded by the cover  200 . 
     The coil  500  is wound around an outer side of the carrier  300 , and adjacent to the first magnets  410 . In the 1st embodiment, the coil  500  is octagon which corresponds to the outer side of the carrier  300 , so that the coil  500  is stably connected around the carrier  300 , and four surfaces of the coil  500  are adjacent to the bottom surface  412  of the first magnets  410 , respectively. It is favorable for contributing efficiency and evenness to the interaction between the first magnets  410  and the coil  500 , so that the carrier  300  can be moved stably, and the lens  800  can also be linked up stably. 
     The spring  600  is coupled to the carrier  300  for providing an elastic supporting force. According to the 1st embodiment of the present disclosure, the spring  600  includes a first spring member  610  and a second spring member  620 , which are coupled to two ends of the carrier  300 , respectively.  FIG. 4A  shows an enlarged view of the first spring member  610  of the lens driving apparatus of the 1st embodiment. In  FIG. 4A , the first spring member  610  includes two first fastening portions  611 , two second fastening portions  612  and four elastic portions  613 , wherein each of the first fastening portions  611  includes at least two holes  611   a  for coupling to the spacer  220 , each of the second fastening portions  612  includes at least two holes  612   a  for coupling to the carrier  300 , each of the elastic portions  613  is connected to one of the first fastening portions  611  and one of the second fastening portions  612  for providing the elastic supporting force. In detail, the first spring member  610  is about quadrangular, the two first fastening portions  611  and the two second fastening portions  612  can be regarded as four sides of the first spring member  610 , wherein each of the first fastening portions  611  is facing each other, and each of the second fastening portions  612  is facing each other. Each of the elastic portions  613  is connected to one end of one of the first fastening portions  611  and one end of one of the second fastening portions  612 . The first fastening portions  611  are connected to the spacer  220  and the second fastening portions  612  are connected to the carrier  300 , so that the first spring member  610  is positioned in the cover  200 . Moreover, in order to couple with different-shaped components, such as the carrier  300  and the spacer  220 , etc., the first spring member  610  can include a first fastening portion  611 , a second fastening portion  612  and two elastic portions  613 , and each of the elastic portions  613  is connected to one end of the first fastening portion  611  and one end of the second fastening portion  612 , and will not draw and describe herein. 
       FIG. 4B  shows an enlarged view of the second spring member  620  of the lens driving apparatus according to the 1st embodiment. The second spring member  620  includes a first portion  621  and a second portion  622 , wherein the first portion  621  and the second portion  622  are separated from each other, coupled to the end of the carrier  300  which is toward the holder  100  and located on a same horizontal plane. 
     The second magnets  420  are disposed on the end of the carrier  300  which is toward the holder  100 , and are movable simultaneously with the carrier  300 , wherein a magnetic polarization direction of each of the second magnets  420  is parallel to an optical axis of the lens  800 , and is orthogonal to a magnetic polarization direction of the first magnet  410 . The magnetic field of the first magnets  410  and the magnetic field of the second magnets  420  are not interacting with each other. The hall sensor  700  is for detecting a magnetic field of any one of the second magnets  420 , wherein the magnetic field is varied according to a relative displacement between the hall sensor  700  and the second magnet  420  which is detected. Therefore, the voltage signal as a feedback can be provided, and the lens  800  can be linked up with the carrier  300  to a predetermined position. The carrier  300  has no need to move back to the original position, and then moves to the predetermined position. In the 1st embodiment, the number of the second magnets  420  is two, and the two second magnets  420  are symmetrically disposed on the end of the carrier  300  about the optical axis of the lens  800 , but are not limited thereto. 
     In  FIG. 3A , when a thickness parallel to an optical axis of the lens  800  of the hall sensor  700  is h, the following condition is satisfied: h&lt;1.0 mm. Therefore, the mechanical complexity can be reduced, and the assembling convenience can be increased. Preferably, the following condition is satisfied: h&lt;0.6 mm. 
     In the 1st embodiment of the present disclosure, the lens driving apparatus can further include a circuit board  900 , which is embedded into the other side of the holder  100 . The hall sensor  700  and an imaging element  810  are connected to the circuit board  900 , and the imaging element  810  is for receiving an imaging light of the lens  800 , the imaging element  810  has 8 million pixels or above. In detail, the different voltage signal represented as the present position on the optical axis of the lens can be output due to the relative displacement between the hall sensor  700  and the second magnet  420 , and the distance between the present position and the predetermined position for focusing can be provided after the circuit board  900  receives the voltage signal, then the outputting current can be provided to the coil  500  for moving the carrier  300  and the lens  800  to the predetermined position for focusing. 
     In  FIG. 3A , when a vertical distance between an outermost side of the end wall  210  of the cover  200  and a side wall  710  of the hall sensor  700  which is connected to the circuit board  900  is H, and the following condition is satisfied: 3.4 mm&lt;H&lt;5.8 mm. Therefore, the sensitivity for detecting the magnetic field can be maintained, and the focusing time can be shortened. 
     The movement of the lens  800  which is linked up with the carrier  300  is adjusted corresponding to the current due to the variation of the magnetic field according to a relative displacement between the hall sensor  700  and the second magnet  420  which is detected. Therefore, the detection of the magnetic field depends on the relative position between the hall sensor  700  and the second magnets  420 . In  FIG. 3A , when a component parallel to an optical axis of the lens  800  of a distance between the center of the hall sensor  700  and the second magnet  420  which is detected is d1, and a component orthogonal to the optical axis of the lens  800  of the distance between the hall sensor  700  and the second magnet  420  which is detected is d2, the following condition is satisfied: d1&gt;d2. Therefore, the compact size of the lens driving apparatus can be maintained. 
     Furthermore, when the component parallel to an optical axis of the lens  800  of a distance between the center of the hall sensor  700  and the second magnet  420  which is detected is d1, the following condition is satisfied: d1&lt;1.4 mm. Preferably, the following condition is satisfied: d1&lt;1.15 mm. 
     In the 1st embodiment of the present disclosure, the number of the second magnets  420 , the vertical distance between an outermost side of the end wall  210  of the cover  200  and a side wall  710  of the hall sensor  700  which is connected to the circuit board  900  (H), the thickness parallel to an optical axis of the lens  800  of the hall sensor  700  ( h ), the component parallel to an optical axis of the lens  800  of a distance between the center of the hall sensor  700  and the second magnet  420  which is detected (d1), and the pixel of the imaging element  810  are listed in the following Table 1. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 1st Embodiment 
               
            
           
           
               
               
               
               
               
            
               
                 the number of the 
                   
                   
                   
                 the pixel of the 
               
               
                 second magnets 
                 H(mm) 
                 h(mm) 
                 d1(mm) 
                 imaging element 
               
               
                   
               
               
                 2 
                 4.885 
                 0.55 
                 1.08 
                 8 million 
               
               
                   
               
            
           
         
       
     
       FIG. 5A  shows a schematic view of the second magnets  420  and the hall sensor  700  of the lens driving apparatus according to the 2nd embodiment.  FIG. 5B  shows a bottom view of the second magnets  420  and the hall sensor  700  of the lens driving apparatus according to the 2nd embodiment. In  FIGS. 5A and 5B , when a component parallel to an optical axis of the lens  800  of a distance between the center of the hall sensor  700  and the second magnet  420  which is detected is d1, and a component orthogonal to the optical axis of the lens  800  of the distance between the hall sensor  700  and the second magnet  420  which is detected is d2, wherein the component orthogonal to the optical axis of the lens  800  of the distance between the hall sensor  700  and the second magnet  420  which is detected (d2) is increased, however, the following condition is also satisfied: d1&gt;d2. 
     In the 2nd embodiment of the present disclosure, the number of the second magnets  420 , the vertical distance between an outermost side of the end wall  210  of the cover  200  and a side wall  710  of the hall sensor  700  which is connected to the circuit board  900  (H), the thickness parallel to an optical axis of the lens  800  of the hall sensor  700  ( h ), the component parallel to an optical axis of the lens  800  of a distance between the center of the hall sensor  700  and the second magnet  420  which is detected (d1), and the pixel of the imaging element  810  are listed in the following Table 2. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 2nd Embodiment 
               
            
           
           
               
               
               
               
               
            
               
                 the number of the 
                   
                   
                   
                 the pixel of the 
               
               
                 second magnets 
                 H(mm) 
                 h(mm) 
                 d1(mm) 
                 imaging element 
               
               
                   
               
               
                 2 
                 4.300 
                 0.32 
                 0.82 
                 16 million 
               
               
                   
               
            
           
         
       
     
       FIG. 6A  shows a schematic view of the second magnets  420  and the hall sensor  700  of the lens driving apparatus according to the 3rd embodiment.  FIG. 6B  shows a bottom view of the second magnets  420  and the hall sensor  700  of the lens driving apparatus according to the 3rd embodiment. In  FIGS. 6A and 6B , when a component parallel to an optical axis of the lens  800  of a distance between the center of the hall sensor  700  and the second magnet  420  which is detected is d1, and a component orthogonal to the optical axis of the lens  800  of the distance between the hall sensor  700  and the second magnet  420  which is detected is d2, wherein the component orthogonal to the optical axis of the lens  800  of the distance between the hall sensor  700  and the second magnet  420  which is detected (d2) is further increased, however, the following condition is also satisfied: d1&gt;d2. 
     In the 3rd embodiment of the present disclosure, the number of the second magnets  420 , the vertical distance between an outermost side of the end wall  210  of the cover  200  and a side wall  710  of the hall sensor  700  which is connected to the circuit board  900  (H), the thickness parallel to an optical axis of the lens  800  of the hall sensor  700  ( h ), the component parallel to an optical axis of the lens  800  of a distance between the center of the hall sensor  700  and the second magnet  420  which is detected (d1), and the pixel of the imaging element  810  are listed in the following Table 3. 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 3rd Embodiment 
               
            
           
           
               
               
               
               
               
            
               
                 the number of the 
                   
                   
                   
                 the pixel of the 
               
               
                 second magnets 
                 H(mm) 
                 h(mm) 
                 d1(mm) 
                 imaging element 
               
               
                   
               
               
                 2 
                 4.370 
                 0.65 
                 0.64 
                 13 million 
               
               
                   
               
            
           
         
       
     
       FIG. 7A  shows a schematic view of the second magnets  420  and the hall sensor  700  of the lens driving apparatus according to the 4th embodiment.  FIG. 7B  shows a bottom view of the second magnets  420  and the hall sensor  700  of the lens driving apparatus according to the 4th embodiment. In  FIGS. 7A and 7B , when a component parallel to an optical axis of the lens  800  of a distance between the center of the hall sensor  700  and the second magnet  420  which is detected is d1, and a component orthogonal to the optical axis of the lens  800  of the distance between the hall sensor  700  and the second magnet  420  which is detected is d2, the following condition is satisfied: d1&gt;d2. 
       FIG. 7C  shows the carrier  300  and the second magnets  420  of the lens driving apparatus according to the 4th embodiment. In  FIG. 7C , the number of the second magnets  420  is four, and every two second magnets  420  which are adjacent to each other are equidistantly disposed on the end of the carrier  300  in a circumferential direction. Furthermore, the number of the second magnets  420  can be two to six, and even number is better, but is not limited thereto. Therefore, the balance of the lens driving apparatus can be enhanced. 
     In the 4th embodiment of the present disclosure, the number of the second magnets  420 , the vertical distance between an outermost side of the end wall  210  of the cover  200  and a side wall  710  of the hall sensor  700  which is connected to the circuit board  900  (H), the thickness parallel to an optical axis of the lens  800  of the hall sensor  700  ( h ), the component parallel to an optical axis of the lens  800  of a distance between the center of the hall sensor  700  and the second magnet  420  which is detected (d1), and the pixel of the imaging element  810  are listed in the following Table 4. 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 4th Embodiment 
               
            
           
           
               
               
               
               
               
            
               
                 the number of the 
                   
                   
                   
                 the pixel of the 
               
               
                 second magnets 
                 H(mm) 
                 h(mm) 
                 d1(mm) 
                 imaging element 
               
               
                   
               
               
                 4 
                 5.230 
                 0.45 
                 0.98 
                 20 million 
               
               
                   
               
            
           
         
       
     
     Therefore, the movement of the lens  800  which is linked up with the carrier  300  is adjusted corresponding to the current due to the variation of the magnetic field according to a relative displacement between the hall sensor  700  and the second magnet  420  which is detected. Hence, the focusing time can be saved. 
     Although the present disclosure has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the present disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims.