Optical system

1. An optical system, comprising:

a first movable portion connected to a first optical element;

a fixed portion, wherein the movable portion is movable relative to the fixed portion;

a first driving assembly driving the first movable portion to move relative to the fixed portion;

a circuit assembly, wherein the first movable portion is movably connected to the fixed portion via the circuit assembly;

a second movable portion connected to a second optical element, wherein the second movable portion is movable relative to the fixed portion and the first movable portion, wherein the first movable portion and the second movable portion are arranged in a first direction; and

a second driving assembly driving the second movable portion to move relative to the fixed portion,

wherein the circuit assembly comprises:

a first circuit element connecting the first movable portion and the fixed portion, comprising:

a movable end, fixedly connected to the first movable portion;

a fixed end, fixedly connected to the fixed portion; and

a flexible portion, wherein the movable end is movably connected to the fixed end via the flexible portion.

2. The optical system as claimed in claim 1 ,

wherein the first movable portion is movable within a first range of motion relative to the fixed portion;

wherein the second movable portion is movable within a second range of motion relative to the fixed portion, wherein the second range of motion is different from the first range of motion; and

wherein the second movable portion is movable within a third range of motion relative to the first movable portion.

3. The optical system as claimed in claim 2 , further comprising:

a first sensing assembly sensing the movement of the first movable portion relative to the fixed portion, comprising:

a first reference magnetic element, including a plurality of first magnetic pole pairs that have N poles and S poles, wherein the first magnetic pole pairs are arranged in the first direction, and in each of the first magnetic pole pairs, an N pole and an S pole are arranged in a first magnetic pole direction, wherein the first magnetic pole direction is perpendicular to the first direction; and

a first sensor corresponding to the first reference magnetic element; and

a second sensing assembly sensing the movement of the second movable portion relative to the first movable portion, comprising:

a second reference magnetic element, including a second magnetic pole pair that has an N pole and an S pole, wherein in the second magnetic pole pair, the N pole and the S pole are arranged in a second magnetic pole direction, wherein the second magnetic pole direction is parallel to the first direction; and

a second sensor, corresponding to the second reference magnetic element, and disposed on the circuit assembly.

4. The optical system as claimed in claim 3 , wherein in the first direction, the largest size of the second reference magnetic element is smaller than the largest size of the first reference magnetic element.

5. The optical system as claimed in claim 3 , wherein the first magnetic pole direction is perpendicular to the second magnetic pole direction.

6. The optical system as claimed in claim 3 , wherein when viewed in a second direction that is perpendicular to the first direction, the first reference magnetic element at least partially overlaps the second reference magnetic element, and the first sensor does not overlap the second sensor.

7. The optical system as claimed in claim 3 , further comprising a control unit, wherein the control unit has first predetermined information and second predetermined information;

wherein the first predetermined information includes the status of a first magnetic field of the first reference magnetic element for each possible location of the first movable portion relative to the fixed portion; and

wherein the second predetermined information includes the status of a second magnetic field of the second reference magnetic element for each possible location of the second movable portion relative to the first movable portion; and

wherein the control unit is electrically connected to the first sensor and the second sensor via the circuit assembly, wherein the first sensor outputs a first sensing signal to the control unit, and the second sensor outputs a second sensing signal to the control unit.

8. The optical system as claimed in claim 7 , wherein the control unit calculates the position of the first movable portion relative to the fixed portion based on the first sensing signal and the first predetermined information, and calculates the position of the second movable portion relative to the first movable portion based on the second sensing signal and the second predetermined information.

9. The optical system as claimed in claim 7 , further comprising a third optical element, fixedly disposed at the fixed portion, and forming an optical unit with the first optical element and the second optical element;

wherein the control unit outputs a first driving signal to the first driving assembly based on a first instruction, and the first driving assembly drives the first movable portion to move, and changes the focal length of the optical unit, thereby performing the function of zooming; and

wherein the control unit outputs a second driving signal to the second driving assembly based on a second instruction, and the second driving assembly drives the second movable portion to move, and changes the image plane of the optical unit, thereby performing the function of focusing.

10. The optical system as claimed in claim 9 , wherein the control unit outputs the first driving signal to the first driving assembly that drives the first movable portion to move before the control unit outputs the second driving signal to the second driving assembly that drives the second movable portion to move, so that the optical system performs the function of zooming before performing the function of focusing.

11. The optical system as claimed in claim 1 , wherein the flexible portion has a plate structure.

12. The optical system as claimed in claim 11 , wherein the flexible portion comprises:

a first section extending in a fourth direction;

a second section extending in a fifth direction; and

a third section extending in a sixth direction;

wherein:

the fourth direction is not parallel to the fifth direction;

the fifth direction is not parallel to the sixth direction; and

the sixth direction is not parallel to the fourth direction.

13. The optical system as claimed in claim 12 , wherein when the first movable portion is in an initial position relative to the fixed portion, and viewed in a second direction that is perpendicular to the first direction,

the first section does not overlap the movable end; and

the first section at least partially overlaps the fixed end.

14. The optical system as claimed in claim 13 , wherein:

the second section does not overlap the movable end; and

the second section at least partially overlaps the fixed end.

15. The optical system as claimed in claim 12 , wherein when the first movable portion is in a first terminal position relative to the fixed portion, and viewed in a second direction that is perpendicular to the first direction,

the first section does not overlap the movable end; and

the first section does not overlap the fixed end.

16. The optical system as claimed in claim 15 , wherein

the second section does not overlap the movable end; and

the second section does not overlap the fixed end.

17. The optical system as claimed in claim 12 , wherein when the first movable portion is in a second terminal position relative to the fixed portion, and viewed in a second direction that is perpendicular to the first direction,

the first section at least partially overlaps the movable end; and

the first section at least partially overlaps the fixed end.

18. The optical system as claimed in claim 17 , wherein

the second section does not overlap the movable end; and

the second section does not overlap the fixed end.