Shake correction apparatus
A shake correction apparatus includes: a stationary portion ( 21 ) having coils ( 22 S, 22 L, 23 S, 23 L, 24 S, 24 L) arranged; a movable portion including magnets ( 52 a, 52 b, 52 c, 52 d, 53 a, 53 b, 53 c, 53 d, 54 a, 54 b, 54 c, 54 d ) opposed to the coils and an imaging element; a supporting member for movably supporting the movable portion to the stationary portion along a plane orthogonal to an optical axis of light entering into the imaging element; means for detecting a position of the movable portion; and means for controlling current flowed into the coils based on output of the detection means, the coils including at least three coil pairs when two coils opposed to each other along the plane orthogonal to the optical axis are paired, driving forces of two coils forming each coil pair being different.
1. A shake correction apparatus comprising:
a stationary portion on which a plurality of coils are arranged;
a movable portion that includes a plurality of magnets arranged to be opposed to the coils, and an optical element or an imaging element;
a supporting member for movably supporting the movable portion with respect to the stationary portion along a plane orthogonal to an optical axis of light entering into the optical element or the imaging element;
detection means for detecting a position of the movable portion; and
control means for controlling a current to be flowed into the coils based on an output of the detection means,
wherein the coils include at least three coil pairs when two coils that are arranged to be opposed to each other along the plane orthogonal to the optical axis are paired as one coil pair, and
wherein in each of the coil pairs, driving forces of two coils forming each of the coil pairs are different from each other.
2. The shake correction apparatus according to claim 1 , wherein the detection means is arranged on an inside of one coil that is smaller in driving force than another coil of the two coils forming each of the at least three coil pairs.
3. The shake correction apparatus according to claim 1 ,
wherein a predetermined position of the stationary portion is located between the two coils forming each of the coil pairs, and
wherein the coils are arranged in a manner to radiate from the predetermined position as a center.
4. The shake correction apparatus according to claim 3 ,
wherein in the at least three coil pairs, ends of coils on a side of the predetermined position of the stationary portion are bent in an arc shape, and
wherein the ends in the arc shape face each other.
5. The shake correction apparatus according to claim 1 ,
wherein each of the coils is assigned with two opposed magnets, and
wherein the two magnets are arranged to face each other along the plane orthogonal to the optical axis.
6. The shake correction apparatus according to claim 1 , further comprising a lid member that is attached to the stationary portion and is arranged in such a position that the movable portion is pinched between the lid member and the stationary portion,
wherein the stationary portion is formed from a magnetic member, and
wherein the movable portion is attached to the stationary portion by magnetic forces of the magnets through the supporting member.
7. The shake correction apparatus according to claim 6 , further comprising a plurality of pillars that attach the lid member to the stationary portion outside a moving region of the movable portion,
wherein each of the pillars includes an abutting surface that defines the moving region of the movable portion by bring the movable portion in abutment.
8. The shake correction apparatus according to claim 1 ,
wherein the movable portion is provided with the imaging element, and
wherein the imaging element is attached to the movable portion in a manner wherein at least a part of the magnets overlaps the imaging element in a direction of an optical axis of light entering into the imaging element.