The optical pickup actuator includes a bobbin in which an objective lens
is mounted, and suspension wires each having one end fixed on a side of
the bobbin and the other end fixed to a holder disposed on a portion of a
base to allow the bobbin to move with respect to the base. A magnetic
circuit is installed in the bobbin and the base including a pair of
unipolar magnets positioned on the base to face two sides of the bobbin.
A focusing coil is wound around the bobbin. A plurality of tilting coils
are installed on an upper portion of the bobbin and/or on a lower portion
of the bobbin interact with the unipolar magnets to generate an
electromagnetic force to control a tilting movement when a central axis
of the objective lens is disposed in an upward and a downward direction.