Lens driving device

1. An lens driving device, comprising:

a base;

a lens holder mounted on the base and defining a core member, a connecting portion extending from one end of the core member, and at least a pair of supporting elements extending upwardly from the connecting portion and setting in space with respect to core member;

a movable cover opposite to the supporting elements;

a elastic supporting portion received in the lens holder and engaged with the movable cover;

a coil attached on the lens holder; and

a permanent magnet attached on the lens holder and interacted with the coil for generating a magnetic force to drive the lens holder to move along a central axis of the core member;

Wherein, the elastic supporting portion defines an elastic force which is more than a weight of the movable cover but not more than the resultant of the weight of the movable cover and the magnetic force;

the lens driving device further defines a movable distance between an upper surface of the supporting elements and a first surface of the movable cover.

2. The lens driving device as described in claim 1 , wherein each supporting element defines a receiving hole for receiving the elastic supporting portion.

3. The lens driving device as described in claim 2 , wherein each elastic supporting portion is configured to be a cylinder.

4. The lens driving device as described in claim 3 , wherein the supporting elements are symmetrical with respect to the central axis of the core member.

5. The lens driving device as described in claim 1 , wherein the lens driving device defines more than two supporting elements and the distances of two adjacent supporting elements are same with one another.

6. The lens driving device as described in claim 1 , wherein the movable cover defines a plurality of first guiding post received into the receiving holes and a length of the first guiding posts is more than the movable distance.

7. The lens driving device as described in claim 1 , wherein the lens driving device further defines a case attached to the base and selected from permeability material.

8. The lens driving device as described in claim 7 , wherein the coil is warped on the core member and the permanent magnet mounted to the adjacent supporting elements.

9. The lens driving device as described in claim 8 , wherein the base defines a plurality of second guiding posts and the lens holder further defines a plurality of engaging holes for receiving the second guiding posts.

10. The lens driving device as described in claim 9 , wherein a part of the receiving holes are communicated with the engaging holes, respectively.

11. A lens driving device, comprising:

a base;

a lens holder mounted on the base and defining a core member, a connecting portion extending from one end of the core member, and at least a pair of supporting elements extending upwardly from the connecting portion and setting in space with respect to core member;

a movable cover opposite to the supporting elements;

a coil wrapped around the core member;

a permanent magnet attached on the lens holder and interacted with the coil for generating a magnetic force to drive the lens holder to move along a central axis of the core member; and

a elastic supporting portion received in the lens holder and engaged with the movable cover;

Wherein, the elastic supporting portion defines an elastic force;

a weight of the movable cover is more than the elastic force of the elastic supporting portion but not more than the resultant of the elastic force and the magnetic force.

12. The lens driving device as described in claim 11 , wherein the lens driving device further defines a case mounted on the base and defining a top sheet and a plurality of sidewalls extending downwardly from the top sheet and a movable distance between a second surface of the movable cover and an inner surface of the top sheet.

13. The lens driving device as described in claim 12 , wherein each elastic supporting portion is configured to be a cylinder.