Optical system

1. An optical system, comprising:

a fixed module;

a movable module, movable relative to the fixed module, the movable module comprising a lens unit, and the lens unit comprising:

a first lens, having a transparent material;

a second lens, having a transparent material, wherein the first lens and the second lens are arranged along an optical axis;

a first side wall, comprising a first surface, wherein the first surface is in direct contact with the second lens, wherein when view along the optical axis, the first side wall is located on a first side of the optical system, and the first side is extended along a first direction; and

a second side wall, being in direct contact with the first lens, wherein when view along the optical axis, the second side wall is located on a second side of the optical system, and the second side is extended along a second direction; and

a driving assembly, a portion of the driving assembly being directly disposed on the lens unit, configured to drive the lens unit to move along the optical axis of the first lens;

wherein the first side wall further comprises a second surface opposite to the first surface, the second surface is in direct contact with the portion of the driving assembly, wherein the maximum dimension of the first side wall in the second direction is greater than the maximum dimension of the second side wall in the first direction.

2. The optical system as claimed in claim 1 , wherein the thickness of the first side wall is greater than the thickness of the second side wall.

3. The optical system as claimed in claim 1 , wherein the second lens is partially exposed from the second side wall.

4. The optical system as claimed in claim 1 , wherein the lens unit further comprises an electrical connecting portion and a surface, the electrical connecting portion is disposed on the surface, and the surface faces a light incident end of the optical axis.

5. The optical system as claimed in claim 4 , wherein the electrical connecting portion is disposed on the first side wall.

6. The optical system as claimed in claim 4 , wherein the optical system further comprises an elastic member, and the elastic member includes an electrical contact, wherein the electrical connecting portion is electrically connected to the electrical contact, and a gap is formed between the electrical contact and the lens unit along the optical axis.

7. The optical system as claimed in claim 6 , wherein the electrical connecting portion includes a protruding portion extending along the optical axis, and a height of the protruding portion along the optical axis is greater than the gap.

8. The optical system as claimed in claim 6 , wherein the elastic member further includes a narrow portion, and the narrow portion is adjacent to the electrical contact.

9. The optical system as claimed in claim 1 , wherein the optical system further comprises an elastic member disposed on the lens unit, and when viewed along the optical axis, the elastic member partially overlaps the second lens.

10. The optical system as claimed in claim 1 , wherein the optical system further comprises a position-sensing assembly, the position-sensing assembly includes a magnetic sensing unit and a magnetic element, and the magnetic element is disposed on the second side wall.

11. The optical system as claimed in claim 10 , wherein the optical system further comprises a circuit unit, the magnetic sensing unit is disposed on the circuit unit, and the circuit unit includes a first side surface and a second side surface respectively corresponding to the first side wall and the second side wall.

12. The optical system as claimed in claim 11 , wherein the magnetic sensing unit is disposed on the second side surface, and the circuit unit further includes an electrical pin disposed on the first side surface.

13. The optical system as claimed in claim 12 , wherein the optical system further comprises a frame, and the frame includes a recessed portion configured to receive a portion of the circuit unit.

14. The optical system as claimed in claim 13 , wherein the frame further includes a lateral stop portion, and the lateral stop portion extends along a direction of the optical axis and corresponds to the second side wall.

15. The optical system as claimed in claim 1 , wherein the fixed module includes a base, the optical system further comprises a plurality of metal members disposed in the base, and at least one metal member is electrically connected to the driving assembly.

16. The optical system as claimed in claim 15 , wherein the base further includes a plurality of protruding columns that extends along a direction of the optical axis, at least one of the metal members is buried in the corresponding protruding column, and the metal member buried in the protruding column is partially exposed from the protruding column.

17. The optical system as claimed in claim 16 , wherein the fixed module further comprises a casing, and some of the metal members are securely connected to the casing.

18. The optical system as claimed in claim 1 , wherein the optical system further comprises a frame and a circuit unit, and the circuit unit is disposed in the frame and electrically connected to the driving assembly.

19. The optical system as claimed in claim 1 , wherein the fixed module further comprises a casing, the casing includes a first side and a second side, the first side is opposite to the second side, the first side and the second side are parallel to the optical axis, and a distance between the optical axis and the first side is not equal to a distance between the optical axis and the second side.

20. The optical system as claimed in claim 19 , wherein the driving assembly is disposed between the first side and the first side wall, and the distance between the optical axis and the first side is greater than the distance between the optical axis and the second side.

21. The optical system as claimed in claim 1 , wherein the optical system further comprises a guiding assembly for guiding the lens unit to move along a first direction relative to the fixed module, wherein when viewed along a direction of the optical axis, the guiding assembly partially overlaps the second lens.