Optical element driving mechanism
An optical element driving mechanism is provided. The optical element driving mechanism includes a movable portion, a fixed portion, and a driving assembly. The movable portion is used to connect the optical element. The movable portion may move relative to the fixed portion. The driving assembly is used to drive the movable portion to move relative to the fixed portion.
1 . An optical element driving mechanism, comprising:
a movable portion used for connecting an optical element;
a fixed portion, wherein the movable portion is movable relative to the fixed portion;
a driving assembly used for driving the movable portion to move relative to the fixed portion;
a first guiding rod disposed on the fixed portion;
a second guiding rod disposed on the fixed portion;
a first positioning magnetic element disposed on the movable portion; and
a second positioning magnetic element disposed on the movable portion.
2 . The optical element driving mechanism as claimed in claim 1 , wherein:
the first guiding rod and the second guiding rod are disposed on opposite sides of the movable portion;
the movable portion comprises a first opening and a second opening;
the first positioning magnetic element is disposed on the first opening; and
the second positioning magnetic element is disposed on the second opening.
3 . The optical element driving mechanism as claimed in claim 2 , wherein:
the fixed portion comprises a case and a base arranged along a main axis, and the main axis extends in a first direction;
the driving assembly is used for driving the movable portion to move relative to the fixed portion in the first direction;
the first positioning magnetic element is exposed from the first opening; and
the second positioning magnetic element is exposed from the second opening.
4 . The optical element driving mechanism as claimed in claim 3 , wherein:
the first guiding rod comprises magnetic permeable material;
the second guiding rod comprises magnetic permeable material;
the first guiding rod is disposed on the base; and
the second guiding rod is disposed on the base.
5 . The optical element driving mechanism as claimed in claim 4 , wherein:
the base comprises a first connecting opening and a second connecting opening;
the first guiding rod connects to the first connecting opening by laser welding; and
the second guiding rod connects to the second connecting opening by laser welding.
6 . The optical element driving mechanism as claimed in claim 5 , further comprising:
a first adhesive element disposed on the first connecting opening to connect the base and the first guiding rod; and
a second adhesive element disposed on the second connecting opening to connect the base and the second guiding rod.
7 . The optical element driving mechanism as claimed in claim 6 , wherein:
the first adhesive element and the first guiding rod at least partially overlap each other in the first direction;
the second adhesive element and the second guiding rod at least partially overlap each other in the first direction;
the first guiding rod does not expose from the first connecting opening in the first direction; and
the second guiding rod does not expose from the second connecting opening in the first direction.
8 . The optical element driving mechanism as claimed in claim 7 , wherein:
a first lubricating coating is disposed on a surface of the first guiding rod;
a second lubricating coating is disposed on a surface of the second guiding rod;
materials of the first lubricating coating and the second lubricating coating comprise Teflon; and
the optical element driving mechanism further comprises a lubricating element disposed on the first guiding rod and the second guiding rod and in direct contact with the first lubricating coating and the second lubricating coating.
9 . The optical element driving mechanism as claimed in claim 8 , wherein:
the first guiding rod comprises a first guiding rod first end and a first guiding rod second end opposite from each other;
the first guiding rod first end is affixed on the base;
the first guiding rod second end is affixed on the case;
the way that the first guiding rod first end connected to the base is different from the way that the first guiding rod second end connected to the case; and
the second guiding rod comprises a second guiding rod first end and a second guiding rod second end opposite from each other.
10 . The optical element driving mechanism as claimed in claim 9 , wherein:
the second guiding rod first end is affixed on the base;
the second guiding rod second end is affixed on the case; and
the way that the second guiding rod first end connected to the base is different from the way that the second guiding rod second end connected to the case.
11 . The optical element driving mechanism as claimed in claim 10 , wherein:
the base comprises a first guiding rod disposing portion and a second guiding rod disposing portion;
the first guiding rod disposing portion comprises first guiding rod disposing recess and a first guiding rod disposing surface;
the first guiding rod disposing surface is disposed in the first guiding rod disposing recess; and
the first guiding rod is disposed in the first guiding rod disposing recess.
12 . The optical element driving mechanism as claimed in claim 11 , wherein:
the first guiding rod protrudes from the first guiding rod disposing recess;
the first guiding rod is in direct contact with the first guiding rod disposing surface;
the second guiding rod disposing portion comprises a second guiding rod disposing recess; and
the second guiding rod is disposed in the second guiding rod disposing recess.
13 . The optical element driving mechanism as claimed in claim 12 , further comprising a position sensing assembly, comprising:
a position sensing element disposed on the fixed portion;
a sensing magnetic element disposed on the movable portion; and
a reinforcement element disposed on the fixed portion.
14 . The optical element driving mechanism as claimed in claim 13 , wherein:
the fixed portion is polygonal;
the fixed portion comprises a first side, a second side, a third side, a fourth side, a fifth side, a sixth side, a seventh side, and an eighth side;
the first side is opposite to the third side;
the second side is opposite to the fourth side;
the fifth side is opposite to the sixth side;
the seventh side is opposite to the eighth side;
the fifth side is between the first side and the second side;
the sixth side is between the second side and the third side;
the seventh side is between the third side and the fourth side;
the eighth side is between the fourth side and the first side;
the first guiding rod is at the fifth side;
the position sensing assembly is at the sixth side; and
the second guiding rod is at the seventh side.
15 . The optical element driving mechanism as claimed in claim 14 , wherein:
the sensing magnetic element comprises a plurality of first sensing magnetic units and a plurality of second sensing magnetic units arranged alternatively in the first direction;
the first sensing magnetic units and the second sensing magnetic units have opposite pole directions; and
the sensing magnetic element and the reinforcement element are disposed on opposite sides of the position sensing element.
16 . The optical element driving mechanism as claimed in claim 15 , further comprising a storage unit and a processing unit disposed on the fixed portion, wherein the processing unit is configured to determine the position of the movable portion relative to the fixed portion according to calibration information stored in the storage unit.
17 . The optical element driving mechanism as claimed in claim 16 , wherein obtaining the calibration information comprises:
moving the movable portion from an initial position to a final position;
sensing a magnetic field of the sensing magnetic element by the position sensing element to obtain a first position information, and the first position information comprises magnetic field values at different positions; and
analyzing the first position information to obtain the calibration information.
18 . The optical element driving mechanism as claimed in claim 17 , wherein analyzing the first position information comprises:
differentiating the first position information to obtain a second position information;
determining a number of sensing magnetic elements passing through the first sensing magnetic units and the second sensing magnetic units based on a number of positive and negative changes in the second position information; and
obtaining a position interval information the number.
19 . The optical element driving mechanism as claimed in claim 18 , wherein analyzing the first position information further comprises:
determining a detailed position of the movable portion relative to the fixed portion based on the position interval information and the magnetic field of the sensing magnetic element sensed by the position sensing element; and
obtaining the calibration information through the detailed position of the movable portion relative to the fixed portion, the position interval information, and the magnetic field.