Lens driving apparatus

1. A lens driving apparatus comprising:

a movable body holding lenses;

a fixed body in which said movable body is mounted being movable along the lens optical axis; and

a drive mechanism that moves said movable body in the lens optical axis direction;

wherein said drive mechanism is equipped with a coil that is held by either said movable body or said fixed body, a magnet that is held by said other body, and a regulatory means that regulates the movement of said movable body which is induced by an electromagnetic force generated when current is passed through said coil,

said fixed body has a cover portion that surrounds said movable body and said magnet,

said coil is wound annularly,

an inner peripheral shape of said cover portion is polygonal, and

said magnet is arranged at a position that includes at least one corner portion of multiple corners in the inner peripheral shape of said cover portion.

2. The lens driving apparatus as set forth in claim 1 , wherein

the inner peripheral shape of said cover portion is square or polygonal in which the corners of the inner peripheral shape of said cover portion are chamfered, and said magnet is arranged at each of said corner portions of the inner peripheral shape of said cover portion.

3. The lens driving apparatus as set forth in claim 1 , wherein said magnet is positioned with said corner portion of said cover portion.

4. A lens driving apparatus comprising:

a movable body holding lenses;

a fixed body in which said movable body is mounted moveably along a lens optical axis direction; and

a drive mechanism that moves said movable body in the lens optical axis direction;

wherein said drive mechanism is equipped with a coil that is held by said movable body or said fixed body, a magnet that is held by the other body of the movable body and the fixed body, and a regulatory means that regulates the movement of said movable body which is induced by an electromagnetic force generated when current is passed through said coil;

wherein said coil is held on an outer circumference of said movable body;

wherein said fixed body has a cover portion that surrounds said movable body and said magnet, and said magnet is arranged along an inner peripheral surface of said cover portion; and

wherein said cover portion is a tube-like body portion of a back yoke, and said magnet is adhered to an inner peripheral surface of said tube-like body portion of said back yoke.

5. The lens driving apparatus as set forth in claim 4 , wherein said fixed body is equipped with a base which is placed on said tube-like body portion of said back yoke, on a side of an image pickup device in the optical axis direction, and a case which is placed on said tube-like body portion of said back yoke, on a photographic subject side; and said back yoke, said base, and said case are in an identical outer peripheral shape when viewed from the optical axis direction.

6. The lens driving apparatus as set forth in claim 4 , wherein said back yoke has an inner yoke which is extended from said tube-like body portion to an inner side of said coil.

7. The lens driving apparatus as set forth in claim 4 , wherein a coil yoke is arranged on an other side of said coil from the side where said magnet is arranged.

8. A lens driving apparatus comprising:

a movable body holding lenses;

a fixed body in which said movable body is mounted moveably along a lens optical axis direction; and

a drive mechanism that moves said movable body in the lens optical axis direction;

wherein said drive mechanism is equipped with a coil that is held by said movable body or said fixed body, a magnet that is held by the other body of the movable body and the fixed body, and a regulatory means that regulates the movement of said movable body which is induced by an electromagnetic force generated when current is passed through said coil;

wherein said coil is held on an outer circumference of said movable body; and

wherein said magnet is magnetized to unlike poles in an inside-outside direction.

9. A lens driving apparatus comprising:

a movable body holding lenses;

a fixed body in which said movable body is mounted moveably along a lens optical axis direction; and

a drive mechanism that moves said movable body in the lens optical axis direction;

wherein said drive mechanism is equipped with a coil that is held by said movable body or said fixed body, a magnet that is held by the other body of the movable body and the fixed body, and a regulatory means that regulates the movement of said movable body which is induced by an electromagnetic force generated when current is passed through said coil;

wherein said coil is held on an outer circumference of said movable body; and

wherein said magnet is composed of multiple magnetic pieces which are layered in the optical axis direction; and said coil is arranged in multiple in the optical axis direction to be opposed to each of said multiple magnetic pieces; and each of said multiple magnetic pieces are magnetized to unlike poles in an inside-outside direction and the magnetizing directions in the inside-outside direction in the magnetic pieces which are adjacent to each other in the optical axis direction are opposite from one another.

10. A lens driving apparatus comprising:

a movable body holding lenses;

a fixed body in which said movable body is mounted moveably along a lens optical axis direction; and

a drive mechanism that moves said movable body in the lens optical axis direction;

wherein said drive mechanism is equipped with a coil that is held by said movable body or said fixed body, a magnet that is held by the other body of the movable body and the fixed body, and a regulatory means that regulates the movement of said movable body which is induced by an electromagnetic force generated when current is passed through said coil;

wherein said coil is held on an outer circumference of said movable body; and

wherein said magnet has a plurality of divided magnetized areas along the optical axis direction, and said coil is arranged in multiple in the optical axis direction to be opposed to each of said plurality of divided magnetized areas; each of said plurality of divided magnetized areas is magnetized to unlike poles in an inside-outside direction, and the magnetizing directions in the inside-outside direction in the magnetized areas which are adjacent to each other in the optical axis direction are opposite from one another.