Tri-Axis Close Loop Feedback Controlling Module for Electromagnetic Lens Driving Device

Abstract

The tri-axis close-loop feedback controlling module for electromagnetic lens driving device comprises a 6-pin Hall element. Two pins of the Hall element are coupled to an auto-focus module for providing a current to drive the auto-focus module to conduct auto-focusing operations along the Z-axis; while other four pins of the Hall element are coupled to a control unit. The control unit detects the X-Y axial positions of the auto-focus module relative to an OIS module and generates a control signal which is then sent to the Hall element. Therefore, the Hall element not only can provide its own feedback controlling function according to the Z-axial position of lens, but also can drive the auto-focus module based on the control signal corresponding to the X-Y axial positions of the auto-focus module, so as to achieve the goal of tri-axis close-loop feedback controlling for the electromagnetic lens driving device.

What is claimed is: 
     
         1 . A tri-axis close-loop feedback controlling module for electromagnetic lens driving device, comprising:
 a lens holder for holding a lens;   a movable frame for receiving the lens holder in such a manner that the lens holder is movable relative to the movable frame along a Z-axis direction;   an electromagnetic driving module, furnished between the movable frame and the lens holder for driving the lens holder to move within the movable frame along the Z-axis direction;   an optical image stabilization (OIS) module for driving the movable frame together with the lens holder to perform bi-directional movements along a X-axis direction and a Y-axis direction; wherein the X-axis, Y-axis and Z-axis are perpendicular to each other;   a control unit, coupled to the OIS module; the control unit being able to detect and control operations of the OIS module so as to generate a control signal according to the operations of the OIS module; and   a Hall element having at least six pins; wherein, two of the at least six pins are coupled with the electromagnetic driving module for supplying a current to the electromagnetic driving module in order to control operations of the electromagnetic driving module; other four of the at least six pins are coupled with the control unit for receiving the control signal from the control unit in order to control the current supplied to the electromagnetic driving module based on the control signal, so as to achieve the function of tri-axis close-loop feedback controlling the electromagnetic driving module.   
     
     
         2 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 1 , further comprising:
 a first circuit board; the control unit being furnished on the first circuit board and coupled with the OIS module; and   an electric coupling structure; the Hall element being coupled with the electromagnetic driving module and the control unit be means of the electric coupling structure;   wherein, the electric coupling structure comprises a first spring plate located at one side of the lens holder along the Z-axis direction; the first spring plate comprises at least four independent and separated first spring members; each one of these first spring members comprises a first inner rim for flexibly retaining a top position of the lens holder along the Z-axis direction and a first contact which is connected with one suspension wire; each one of the suspension wires extends from the first spring members toward the first circuit board and couples to the control unit; the Hall element is coupled with the four first spring members and the electromagnetic driving module, and can receive a control signal from the control unit via the suspension wires in order to control and adjust a current provided by the Hall element to the electromagnetic driving module.   
     
     
         3 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 2 , wherein the first spring plate is in the form of hollowed out thin metal plate; in addition, each one of the first spring members of first spring plate comprises: a first outer rim connected to the movable frame, a first inner rim connected to the lens holder, at least one first inner string extending and connecting between the first outer rim and the first inner rim, and a first contact located at the first outer rim; each one of the suspension wires has its one end thereof being correspondingly connected to one of the first contacts. 
     
     
         4 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 3 , wherein the electromagnetic lens driving device further comprises a second circuit board; the Hall element is furnished on the second circuit hoard; a sensing magnet for Z-axis position is furnished on the lens holder at a location corresponding to the Hall element; in addition, the end of each suspension wire which is connected to the first contact is coupled with the second circuit board, and thus is further coupled to one of the pins of the Hall element via the second circuit board. 
     
     
         5 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 4 , wherein the electric coupling structure further comprises a second spring plate located at a lower side of the lens holder along the Z-axis direction opposite to the first spring plate; the second spring plate comprises at least two individual and separated second spring member; each one of the second spring members comprises: a second outer rim connected to the movable frame, a second inner rim fixed on the lens holder for flexibly retaining a bottom position of the lens holder along the Z-axis direction, at least one second inner string extending and connecting between the second outer rim and the second inner rim, and a second contact located at the second outer rim; wherein the electromagnetic driving module comprises at least a driving coil furnished on the lens holder and at least two driving magnets mounted on the movable frame and corresponding to the driving coil; wherein the second inner rim of each second spring member is electric coupled with the driving coil of the electromagnetic driving module; in addition, the second contact of each second spring member is coupled to the second circuit board and thus is further coupled with one of the pins of the Hall element. 
     
     
         6 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 5 , wherein the second contact of each one of the second spring members is coupled to the second circuit board by means of one of the following structures: bending a thin elongated extending part extended from the second contact toward the second circuit so as to let an end of the extending part connect to the second circuit board, and soldering a connecting wire at the second contact and let an end of the connecting wire connect to the second circuit board. 
     
     
         7 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 4 , wherein the first spring plate includes at least six independent and separated first spring members; wherein, among these six first spring members, there are four first spring members that each of these four first spring members includes the first contact which is coupled with the control unit by means of the suspension wire; while the other two first spring members do not connect to the suspension wires and are coupled to the electromagnetic driving module via the first inner rim;
 wherein the electromagnetic driving module comprises at least a driving coil furnished on the lens holder and at least two driving magnets mounted on the movable frame and corresponding to the driving coil;   wherein the first inner rim of each one of the other two first spring members is coupled with the coil of the electromagnetic driving module; in addition, the first outer rim of each one of the other two first spring members is coupled to the second circuit board and is further coupled to one of the pins of the Hall element in order to supply the current to the electromagnetic driving module in order to control operations of the electromagnetic driving module.   
     
     
         8 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 2 , wherein the OIS module comprises:
 at least a first stabilizing coil furnished on the first circuit board and coupled to the control unit;   at least a second stabilizing coil furnished on the first circuit board and are perpendicular to the first stabilizing coils; in addition, the second stabilizing coils being coupled to the control unit;   at least a first stabilizing magnet mounted on the movable frame and corresponding to the first stabilizing coil;   at least a second stabilizing magnet mounted on the movable frame and corresponding to the second stabilizing coil; and   at least two position sensors mounted on the first circuit board and coupled to the control unit; the at least two position sensors being used to detect the position of the movable frame relative to the first circuit board along the X-axis direction and the Y-axis direction;   
     
     
         9 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 8 , the first and second stabilizing magnets are the same with the driving magnets of the electromagnetic driving module. 
     
     
         10 . A tri-axis close-loop feedback controlling module for electromagnetic lens driving device, comprising:
 a lens holder for holding a lens;   a movable frame for receiving the lens holder in such a manner that the lens holder is movable relative to the movable frame along a Z-axis direction;   an electromagnetic driving module, furnished between the movable frame and the lens holder for driving the lens holder to move within the movable frame along the Z-axis direction;   a first circuit board;   an optical image stabilization (OIS) module furnished between the first circuit board and the movable frame for driving the movable frame together with the lens holder to perform bi-directional movements along a X-axis direction and a Y-axis direction; wherein the X-axis, Y-axis and Z-axis are perpendicular to each other;   a control unit, coupled to the OIS module; the control unit being able to detect and control operations of the OIS module so as to generate a control signal according to the operations of the OIS module;   a first spring plate located at one side of the lens holder along the Z-axis direction; the first spring plate comprising at least four independent and separated first spring members; each one of these first spring members comprising a first inner rim for flexibly retaining a top position of the lens holder along the Z-axis direction and a first contact which is connected with one suspension wire; each one of the suspension wires being extending from the first spring members toward the first circuit board and coupling to the control unit; and   a Hall element coupled with the four first spring members and the electromagnetic driving module, and being able to receive a control signal from the control unit via the suspension wires in order to control and adjust a current provided by the Hall element to the electromagnetic driving module.   
     
     
         11 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 10 , wherein the Hall element has at least six pins; wherein, two of the at least six pins are coupled with the electromagnetic driving module for supplying the current to the electromagnetic driving module in order to control operations of the electromagnetic driving module; other four of the at least six pins are coupled with the control unit for receiving the control signal from the control unit in order to control the current supplied to the electromagnetic driving module based on the control signal. 
     
     
         12 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 11 , wherein the first spring plate is in the form of hollowed out thin metal plate; in addition, each one of the first spring members of first spring plate comprises: a first outer rim connected to the movable frame, a first inner rim connected to the lens holder, at least one first inner string extending and connecting between the first outer rim and the first inner rim, and a first contact located at the first outer rim; each one of the suspension wires has its one end thereof being correspondingly connected to one of the first contacts. 
     
     
         13 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 12 , wherein the electromagnetic lens driving device further comprises a second circuit board; the Hall element is furnished on the second circuit board; a sensing magnet for Z-axis position is furnished on the lens holder at a location corresponding to the Hall element, in addition, the end of each suspension wire which is connected to the first contact is coupled with the second circuit board, and thus is further coupled to one of the pins of the Hall element via the second circuit board. 
     
     
         14 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 13 , wherein the electric coupling structure further comprises a second spring plate located at a lower side of the lens holder along the Z-axis direction opposite to the first spring plate; the second spring plate comprises at least two individual and separated second spring member; each one of the second spring members comprises: a second outer rim connected to the movable frame, a second inner rim fixed on the lens holder for flexibly retaining a bottom position of the lens holder along the Z-axis direction, at least one second inner string extending and connecting between the second outer rim and the second inner rim, and a second contact located at the second outer rim; wherein the electromagnetic driving module comprises at least a driving coil furnished on the lens holder and at least two driving magnets mounted on the movable frame and corresponding to the driving coil; wherein the second inner rim of each second spring member is electric coupled with the driving coil of the electromagnetic driving module; in addition, the second contact of each second spring member is coupled to the second circuit board and thus is further coupled with one of the pins of the Hall element. 
     
     
         15 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 14 , wherein the second contact of each one of the second spring members is coupled to the second circuit board by means of one of the following structures: bending a thin elongated extending part extended from the second contact toward the second circuit so as to let an end of the extending part connect to the second circuit board, and soldering a connecting wire at the second contact and let an end of the connecting wire connect to the second circuit board. 
     
     
         16 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 13 , wherein the first spring plate includes at least six independent and separated first spring members; wherein, among these six first spring members, there are four first spring members that each of these four first spring members includes the first contact which is coupled with the control unit by means of the suspension wire; while the other two first spring members do not connect to the suspension wires and are coupled to the electromagnetic driving module via the first inner rim;
 wherein the electromagnetic driving module comprises at least a driving coil furnished on the lens holder and at least two driving magnets mounted on the movable frame and corresponding to the driving coil;   wherein the first inner rim of each one of the other two first spring members is coupled with the coil of the electromagnetic driving module; in addition, the first outer rim of each one of the other two first spring members is coupled to the second circuit board and is further coupled to one of the pins of the Hall element in order to supply the current to the electromagnetic driving module in order to control operations of the electromagnetic driving module.   
     
     
         17 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 11 , wherein the OIS module comprises:
 at least a first stabilizing coil furnished on the first circuit board and coupled to the control unit;   at least a second stabilizing coil furnished on the first circuit board and are perpendicular to the first stabilizing coils; in addition, the second stabilizing coils being coupled to the control unit;   at least a first stabilizing magnet mounted on the movable frame and corresponding to the first stabilizing coil;   at least a second stabilizing magnet mounted on the movable frame and corresponding to the second stabilizing coil; and   at least two position sensors mounted on the first circuit board and coupled to the control unit; the at least two position sensors being used to detect the position of the movable frame relative to the first circuit board along X-axis direction and the Y-axis direction.   
     
     
         18 . The tri-axis close-loop feedback controlling module for electromagnetic lens driving device of  claim 17 , wherein, the first and second stabilizing magnets are the same with the driving magnets of the electromagnetic driving module.