Patent ID: 7899317

Claim:
A driving device for driving an object to be driven, the driving device comprising: a hollow column-shaped magnet extending in a direction along a predetermined axis, the magnet having a plurality of magnetized parts spirally extending along an outer peripheral surface thereof; a first stator unit having a first yoke, a second yoke, and a first coil, each of the first yoke and the second yoke being formed of a soft magnetic material and having a plurality of magnetic pole teeth extending in the spiral direction, each of the magnetic pole teeth of the first and second yokes being disposed in opposed relation to a corresponding one of the magnetized parts of the magnet, the first coil magnetizing the first yoke and the second yoke, the first coil being interposed between the first yoke and the second yoke in the direction along the predetermined axis; a second stator unit having a third yoke, a fourth yoke, and a second coil, each of the third yoke and the fourth yoke being formed of a soft magnetic material and having a plurality of magnetic pole teeth extending in the spiral direction, each of the magnetic pole teeth of the third and fourth yokes being disposed in opposed relation to a corresponding one of the magnetized parts of the magnet, the second coil magnetizing the third yoke and the fourth yoke, the second coil being interposed between the third yoke and the fourth yoke in the direction along the predetermined axis; a base plate to which the first stator unit and the second stator unit are fixed in the direction along the predetermined axis; a holding member that holds the object to be driven and supports the magnet such that the magnet is movable in the direction along the predetermined axis with respect to the base plate; and a guide bar slidably fitted to a hollow part of the magnet, the guide bar guiding the magnet in the direction along the predetermined axis, wherein the first coil and the second coil are energized to move the holding member in the direction along the predetermined axis to thereby drive the object to be driven.