Camera module

1. A camera module comprising:

a housing accommodating a lens module;

a driving unit comprising a magnet disposed on the lens module and a coil disposed to face the magnet;

a yoke configured to generate attractive force with the magnet;

a first ball member accommodated in a first receiving space disposed between the lens module and the housing, and pressed by the attractive force; and

a second ball member accommodated in a second receiving space disposed between the lens module and the housing, and pressed by the attractive force,

wherein a length of the first receiving space in an optical axis direction is different from a length of the second receiving space in the optical axis direction.

2. The camera module of claim 1 , wherein the first ball member comprises first balls disposed in the optical axis direction and the second ball member comprises second balls disposed in the optical axis direction, and at least two of the first balls have differing sizes.

3. The camera module of claim 2 , wherein a number of the first balls is different from a number of the second balls.

4. The camera module of claim 3 , wherein an uppermost ball and a lowermost ball in the optical axis direction, among the first balls, are greater in size than at least one ball located between the uppermost ball and the lowermost ball, and

the second balls have sizes corresponding to each other.

5. The camera module of claim 3 , wherein a first uppermost ball and a first lowermost ball in the optical axis direction, among the first balls, are greater in size than at least one ball located between the first uppermost ball and the first lowermost ball, and

a second uppermost ball and a second lowermost ball in the optical axis direction, among the second balls, are greater in size than at least one ball located between the second uppermost ball and the second lowermost ball.

6. The camera module of claim 1 , further comprising a case coupled to the housing to enclose at least a portion of an outer surface of the housing.

7. The camera module of claim 6 , wherein the housing comprises a first protrusion protruding toward the first ball member and a second protrusion protruding toward the second ball member.

8. The camera module of claim 7 , wherein a length of the first protrusion is different from a length of the second protrusion in the optical axis direction.

9. The camera module of claim 6 , wherein the case comprises a third protrusion protruding toward the first ball member and a fourth protrusion protruding toward the second ball member.

10. The camera module of claim 9 , wherein a length of the third protrusion is different from a length of the fourth protrusion in the optical axis direction.

11. A camera module comprising:

a housing accommodating a lens module;

a driving unit comprising a magnet disposed on the lens module and a coil disposed to face the magnet;

a yoke configured to generate attractive force with the magnet; and

a first ball member disposed between the lens module and the housing and pressed by the attractive force, and comprising first balls arranged in an optical axis direction; and

a second ball member disposed between the lens module and the housing and pressed by the attractive force, and comprising second balls arranged in the optical axis direction,

wherein a first distance between a center of a first uppermost ball and a center of a first lowermost ball in the optical axis direction, among the first balls, is different from a second distance between a center of a second uppermost ball and a center of a second lowermost ball in the optical axis direction, among the second balls.

12. The camera module of claim 11 , wherein a number of the first balls is different from a number of the second balls,

the first uppermost ball and the first lowermost ball are greater in size than at least one ball located between the first uppermost ball and the first lowermost ball, and

the second uppermost ball and the second lowermost ball are greater in size than at least one ball located between the second uppermost ball and the second lowermost ball.

13. The camera module of claim 11 , wherein a number of the first balls is different from a number of the second balls,

the first uppermost ball and the first lowermost ball are greater in size than at least one ball located between the first uppermost ball and the first lowermost ball, and

the second balls have sizes corresponding to each other.

14. The camera module of claim 11 , wherein the second lowermost ball is disposed higher than the first lowermost ball in the optical axis direction.

15. The camera module of claim 11 , wherein the second uppermost ball is disposed lower than the first uppermost ball in the optical axis direction.

16. A camera module comprising:

a housing comprising a first receiving groove and a second receiving groove;

a lens module accommodated in the housing and comprising a third receiving groove facing the first receiving groove and a fourth receiving groove facing the second receiving groove;

first ball bearings disposed is a first space defined by the first receiving groove and the third receiving groove; and

second ball bearings disposed is a second space defined by the second receiving groove and the fourth receiving groove,

wherein the housing comprises a first protrusion protruding into the first space and a second protrusion protruding into the second space, and a length of the first protrusion in an optical axis direction is different from a length of the second protrusion in the optical axis direction.

17. The camera module of claim 16 , wherein the lens module comprises a third protrusion protruding into the first space and a fourth protrusion protruding into the second space, and a length of the third protrusion in the optical axis direction is different from a length of the fourth protrusion in the optical axis direction.

18. The camera module of claim 16 , wherein a length of the first space in the optical axis direction is different from a length of the second space in the optical axis direction.