Driving mechanism

1. A driving mechanism for moving a first optical unit and a second optical unit, comprising:

a movable part, connected to the first optical unit;

a connecting part, connected to the movable part and forming a longitudinal guiding structure;

a first driving unit, comprising an SMA element to impel the movable part and the first optical unit relative to the connecting part;

a slider, movably disposed on the movable part and connected to the SMA element;

a holder, connected to the second optical unit and the connecting part;

a base, connected to the holder; and

a second driving unit, configured to impel the holder and the second optical unit relative to the base;

wherein the SMA element has a first length when the movable part is in a first position relative to the connecting part, and when a current signal is applied to the SMA element, the SMA element shrinks from a first length to a second length and impels the movable part from the first position to a second position relative to the connecting part;

wherein the slider contacts a first end of the guiding structure when the movable part is in the first position relative to the connecting part, and when the slider is impelled by the SMA element along the guiding structure from the first end to a second end of the guiding structure, the movable part is pushed by the slider from the first position to the second position.

2. The driving mechanism as claimed in claim 1 , further comprising a housing connected to the base, wherein the connecting part, the movable part, the first driving unit, the holder, the base, and the second driving unit are received in the housing.

3. The driving mechanism as claimed in claim 2 , wherein the holder has a connection surface affixed to the connecting part, and the connection surface is covered by the housing when viewed along an optical axis of the second optical unit.

4. The driving mechanism as claimed in claim 2 , wherein the housing forms a hole, and the width of the hole is less than the width of the second optical unit.

5. The driving mechanism as claimed in claim 2 , wherein the holder forms a protrusion extending toward and connecting to the connecting part.

6. The driving mechanism as claimed in claim 5 , wherein the connecting part includes a frame and a bottom plate, and the protrusion is connected to the bottom plate.

7. The driving mechanism as claimed in claim 2 , wherein the connecting part forms a protruding portion extending toward and connecting to the holder.

8. The driving mechanism as claimed in claim 7 , wherein the connecting part includes a frame and a bottom plate, and the protruding portion is formed on the bottom plate.

9. The driving mechanism as claimed in claim 2 , wherein the second optical unit extends into the connecting part.

10. The driving mechanism as claimed in claim 2 , wherein the first optical unit, the movable part, the connecting part, the holder, and the base are sequentially arranged along an optical axis of the second optical unit.

11. The driving mechanism as claimed in claim 1 , wherein the guiding structure comprises a longitudinal slot.

12. The driving mechanism as claimed in claim 11 , wherein the connecting part has a polygonal shape, and a tilt angle is formed between the guiding structure and a side of the connecting part.

13. The driving mechanism as claimed in claim 12 , wherein the tilt angle is 45 degree.

14. The driving mechanism as claimed in claim 1 , wherein the movable part has an annular structure with a longitudinal rail formed on it, and the slider extends through the rail to the guiding structure.

15. The driving mechanism as claimed in claim 14 , wherein the rail extends in a first direction, and the guiding structure extends in a second direction that is neither parallel nor perpendicular to the first direction.

16. The driving mechanism as claimed in claim 15 , wherein an included angle is formed between the first and second directions, and the included angle ranges from 20 degree to 70 degree.