Sensor actuator with length-adjustable wires and camera module including the same
A sensor actuator is provided. The sensor actuator includes a movable body on which an image sensor having an imaging plane is disposed; a fixed body configured to accommodate the movable body; and a driver configured to provide a driving force to move the image sensor, wherein the driver includes a wire portion having a plurality of wires of which lengths change when power is applied to the plurality of wires, wherein each of the plurality of wires is configured to have a first end coupled to the fixed body and a second end coupled to the movable body, and wherein one of the first end and the second end of each of the plurality of wires is connected to the fixed body or the movable body through an elastic portion.
1. A sensor actuator, comprising:
a movable body on which an image sensor having an imaging plane is disposed;
a fixed body, configured to accommodate the movable body; and
a driver, configured to provide a driving force to move the image sensor,
wherein the driver comprises a plurality of wires which have lengths that vary to provide the driving force when power is applied to each of the plurality of wires,
wherein each of the plurality of wires is configured to have a first end coupled to the fixed body and a second end coupled to the movable body,
wherein one of the first end and the second end of each of the plurality of wires is connected to the fixed body or the movable body through an elastic portion,
wherein the plurality of wires comprise a first wire portion, a second wire portion, a third wire portion, and a fourth wire portion,
wherein each of the first wire portion to the fourth wire portion comprise two wires, and
wherein each of the first wire portion to the fourth wire portion is configured to have the first end fixed to the fixed body and the second end fixed to the movable body.
2. The sensor actuator of claim 1 ,
wherein the fixed body comprises a first support plate, and the movable body comprises a second support plate, and
wherein the elastic portion is disposed on one of the first support plate and the second support plate.
3. The sensor actuator of claim 1 ,
wherein each of the first wire portion and the second wire portion is configured to provide a driving force to move the movable body in a first direction parallel to the imaging plane, and
wherein a moving direction of the movable body based on an operation of the first wire portion and a moving direction of the movable body based on an operation of the second wire portion are opposite to each other.
4. The sensor actuator of claim 3 ,
wherein a length of one of the first wire portion and the second wire portion is reduced when power is applied to the one of the first wire portion and the second wire portion, and
wherein the elastic portion connected to wire portions other than the one of the first wire portion and the second wire portion is elastically deformed.
5. The sensor actuator of claim 3 ,
wherein each of the third wire portion and the fourth wire portion is configured to provide a driving force to move the movable body in a second direction parallel to the imaging plane, and
wherein a moving direction of the movable body based on an operation of the third wire portion and a moving direction of the movable body based on an operation of the fourth wire portion are opposite to each other.
6. The sensor actuator of claim 5 ,
wherein a length of one of the third wire portion and the fourth wire portion is reduced when power is applied to the one of the third wire portion and the fourth wire portion, and
wherein the elastic portion connected to wire portions other than the one of the third wire portion and the fourth wire portion is elastically deformed.
7. The sensor actuator of claim 5 , wherein the movable body is configured to rotate by at least two wires which are configured to generate driving forces in opposite directions.
8. The sensor actuator of claim 1 ,
wherein each of the first wire portion and the second wire portion is configured to provide a driving force to move the movable body in a first direction parallel to the imaging plane,
wherein the two wires of the first wire portion and the two wires of the second wire portion are spaced apart from each other in a second direction parallel to the imaging plane, and
wherein the first direction and the second direction are perpendicular to each other.
9. The sensor actuator of claim 8 ,
wherein each of the third wire portion and the fourth wire portion are configured to provide a driving force to move the movable body in the second direction, respectively, and
wherein the two wires of the third wire portion and the two wires of the fourth wire portion are spaced apart from each other in the first direction.
10. The sensor actuator of claim 1 , wherein a ball member, configured
to support movement of the movable body, is disposed between the movable body and
the fixed body.
11. The sensor actuator of claim 1 , further comprising:
a support substrate configured to support the movable body such that the movable body moves,
wherein the support substrate comprises a deformable portion that is elastically deformed as the movable body moves.
12. The sensor actuator of claim 11 ,
wherein the support substrate further comprises a movable portion on which the movable body is disposed, and a fixed portion coupled to the fixed body, and
wherein the elastic portion elastically connects the movable portion to the fixed portion.
13. The sensor actuator of claim 1 , further comprising:
a position sensing portion configured to sense a position of the image sensor, and comprising a sensing coil disposed on one of the movable body and the fixed body, and a sensing yoke portion disposed on the other of the movable body and the fixed body,
wherein the sensing yoke portion comprises a plurality of sensing yokes spaced apart from each other in a direction parallel to the imaging plane, and
wherein each sensing yoke is configured to have a width that changes in a moving direction of the image sensor.
14. The sensor actuator of claim 13 ,
wherein the plurality of sensing yokes comprise a first sensing yoke and a second sensing yoke,
wherein each of the first sensing yoke and the second sensing yoke opposes the sensing coil in a direction perpendicular to the imaging plane, and
wherein each of the first sensing yoke and the second sensing yoke has a width that increases and decreases in a moving direction of the image sensor, and positions of the first sensing yoke and the second sensing yoke in which widths increase or decrease have different shapes.
15. A camera module, comprising:
a lens module comprising at least one lens;
a housing configured to accommodate the lens module;
a first driver configured to move the lens module in an optical axis direction;
a fixed body coupled to the housing;
a movable body accommodated in the fixed body and comprising an image sensor disposed therein;
a second driver configured to provide a driving force to move the image sensor in a first direction and a second direction perpendicular to the optical axis direction,
wherein the second driver comprises a plurality of wires which have lengths that vary to provide the driving force when power is applied to each of the plurality of wires,
wherein each of the plurality of wires is configured to have a first end coupled to the fixed body and a second end coupled to the movable body,
wherein one of the first end and the second end of each wire of the plurality of wires is connected to the fixed body or the movable body through an elastic portion,
wherein the plurality of wires comprise a first wire portion, a second wire portion, a third wire portion, and a fourth wire portion,
wherein each of the first wire portion to the fourth wire portion comprise two wires, and
wherein each of the first wire portion to the fourth wire portion is configured to have the first end fixed to the fixed body and the second end fixed to the movable body.
16. An apparatus, comprising:
a camera module, comprising:
a movable body on which an image sensor is disposed;
a fixed body configured to accommodate the movable body;
a driver, configured to provide a driving force to move the image sensor, the driver comprising:
wire portions comprising first ends coupled to the fixed body and second ends coupled to the movable body, and configured to provide a driving force to move the moveable body in first and second directions parallel to an imaging plane of the image sensor, and configured to rotate the movable body about an optical axis;
wherein each of the wire portions has a length that varies to provide the driving force when power is applied to each of the wire portions,
wherein the wire portions comprise a first wire portion, a second wire portion, a third wire portion, and a fourth wire portion,
wherein each of the first wire portion to the fourth wire portion comprise two wires, and
wherein each of the first wire portion to the fourth wire portion is configured to have the first end fixed to the fixed body and the second end fixed to the movable body.
17. The apparatus of claim 16 , wherein each of the wire portions is a shape memory alloy.
18. The apparatus of claim 16 , wherein the first direction comprises directions that are opposite to each other,
the second direction comprises directions that are opposite to each other, and
the first direction is perpendicular to the second direction.