A driving device which makes it possible to reduce the moment of inertia
of a rotor and increase torque. A magnet is formed to have a hollow
cylindrical shape and has magnetized sections which are magnetized to
have alternately different poles in a circumferential direction thereof.
A coil is wound coaxially with the magnet and is disposed in axially
side-by-side relation to the magnet. A stator yoke is formed of a soft
magnetic material and fixes the magnet and the coil. A rotor yoke is
formed of a soft magnetic material, and has magnetic pole portions formed
in opposed relation to the magnetized sections, for being magnetized by
the coil. The rotor yoke is supported in a manner rotatable with respect
to the stator yoke. An rotation restricting part limits a range of
rotation of the rotor yoke within a predetermined angle.