An optical pickup device is provided with a plurality of object lens
corresponding to various kinds of optical discs having different
recording densities, in which the structure of the optical pickup device
is simplified and the size of the optical pickup device is minimized. The
optical pickup device comprises a bobbin including an upper surface, at
which first and second object lenses are mounted, an opened lower
surface, and a first and second side surfaces supported by a supporting
unit, the first and second side surfaces being opposite to each other, a
first focus coil and a first tracking coil mounted at a third side
surface of the bobbin, a second focus coil and a second tracking coil
mounted at a fourth side surface of the bobbin, which is opposite to the
third side surface, and magnets disposed opposite to the first and second
focus coils and the first and second tracking coils.