Lens drive device

A lens drive device for use with at least one lens comprising:

• a movable body which holds the lens and is movable in an optical axis direction of the lens;
• a fixed body which movably holds the movable body in the optical axis direction;
• and
• a drive mechanism for driving the movable body in the optical axis direction;
• wherein the drive mechanism comprises:
• a drive coil which is fixed to the movable body;
• and
• a plurality of drive magnets which are formed in a substantially columnar shape or a substantially plate shape and fixed to the fixed body, the drive magnets being magnetized so that a magnetic pole of one end face is different from a magnetic pole of the other end face in the optical axis direction;
• wherein the fixed body comprises:
• an outer peripheral side magnetic member which is formed of magnetic material and formed in a substantially tube-like shape and structures an outer peripheral face of the fixed body;
• and
• an end face side magnetic member which is formed of magnetic material and to which the one end face of the drive magnet is fixed;
• wherein an inner peripheral face of the outer peripheral side magnetic member and a side face of the drive magnet are faced each other through a predetermined space;
• wherein the outer peripheral side magnetic member, the end face side magnetic member and the drive magnet are disposed so that a magnetic field is formed so as to pass through the drive magnet, the end face side magnetic member and the outer peripheral side magnetic member and returned to the other end face of the drive magnet from the inner peripheral face of the outer peripheral side magnetic member, or returned to the inner peripheral face of the outer peripheral side magnetic member from the other end face of the drive magnet;
• and
• wherein the drive coil is disposed between the other end face side of the drive magnet and the inner peripheral face of the outer peripheral side magnetic member.