Camera module
There is provided a camera module including a plurality of ball bearings to support the driving of a lens barrel at the time of compensating for unintended camera movement due to disturbance such as hand shake. The lens barrel may be driven in first and second directions, independently, by one driving force exerted in the first direction perpendicular to an optical axis and by another driving force exerted in the second direction perpendicular to both the optical axis and the first direction, thereby preventing driving displacement from being generated at the time of compensating for unwanted motion such as hand shake while securing reliability against external impact, and having reduced power consumption at the time of compensating for the disturbance.
1. A camera module, comprising:
a first frame, configured to accommodate a lens module;
a housing configured to accommodate the first frame;
a disturbance compensation part, configured to drive the lens module in a first direction perpendicular to an optical axis direction, and a second direction perpendicular to both the first direction and the optical axis direction; and
a plurality of yoke parts mounted in the first frame, and configured to face the disturbance compensation part in the optical axis direction,
wherein the first frame is configured to be movable in the optical axis direction together with the lens module,
wherein the disturbance compensation part comprises a first magnet and a second magnet attached to the lens module, a first coil opposing the first magnet in the first direction and a second coil opposing the second magnet in the second direction,
wherein a length between two ends of the first magnet in the second direction is shorter than a length between two ends of the first coil in the second direction, and a length between two ends of the second magnet in the first direction is shorter than a length between two ends of the second coil in the first direction, and
wherein a magnetic attraction acts between the plurality of yoke parts and the first and second magnets in the optical axis direction.
2. The camera module of claim 1 , wherein a length between two ends of the first magnet in the optical axis direction is shorter than a length between two ends of the first coil in the optical axis direction, and a length between two ends of the second magnet in the optical axis direction is shorter than a length between two ends of the second coil in the optical axis direction.
3. The camera module of claim 1 , wherein the first coil and the second coil have a loop shape in which a hole is respectively formed, a length between two ends of the first magnet in the optical axis direction is greater than a length of the hole of the first coil in the optical axis direction and is shorter than a length between two ends of the first coil in the optical axis direction, and a length between two ends of the second magnet in the optical axis direction is greater than a length of the hole of the second coil in the optical axis direction and is shorter than a length between two ends of the second coil in the optical axis direction.
4. The camera module of claim 1 , wherein a first driving force is generated in the first direction in which the first coil opposes the first magnet, and a second driving force is generated in the second direction in which the second coil opposes the second magnet.
5. The camera module of claim 1 , wherein the lens module comprises a lens barrel including a lens and a second frame and a third frame accommodating the lens barrel, and the first magnet and the second magnet are mounted in the third frame.
6. The camera module of claim 5 , wherein the second frame and the third frame are configured to be movable in the optical axis direction together with the first frame, the second frame and the third frame are configured to be movable in the first direction within the first frame, and the third frame is configured to be movable, relative to the second frame, in the second direction within the first frame.
7. The camera module of claim 6 , wherein the first frame and the second frame are provided with a first ball bearing part therebetween, the first ball bearing part being moved in the first direction in a rolling motion.
8. The camera module of claim 7 , wherein the first frame and the second frame respectively include a first accommodation groove configured to accommodate the first ball bearing part.
9. The camera module of claim 8 , wherein the first accommodation groove guides the first ball bearing part to be moved in the first direction in the rolling motion and restricts a movement of the first ball bearing part in a direction perpendicular to the first direction.
10. The camera module of claim 6 , wherein the second frame and the third frame are provided with a second ball bearing part therebetween, the second ball bearing part being moved in the second direction in a rolling motion.
11. The camera module of claim 10 , wherein the second frame and the third frame respectively include a second accommodation groove configured to accommodate the second ball bearing part.
12. The camera module of claim 11 , wherein the second accommodation groove guides the second ball bearing part to be moved in the second direction in the rolling motion and restricts a movement of the second ball bearing part in a direction perpendicular to the second direction.
13. The camera module of claim 1 , wherein the first frame and the housing are provided with a third ball bearing part therebetween, the third ball bearing part being moved in the optical axis direction in a rolling motion.
14. The camera module of claim 1 , further comprising an auto-focus driving part configured to generate driving force in the optical axis direction,
wherein the auto-focus driving part comprises a third magnet attached to the first frame and a third coil disposed to face the third magnet.