An apparatus to drive a blade on which an objective lens is mounted including
a first electromagnetic unit to generate a first electromagnetic force and a second
electromagnetic unit to generate a second electromagnetic force such that when
the first and second magnitudes are the same, the blade is driven in a focus direction,
and when the magnitudes are different, the blade is driven in a tilt direction.
Accordingly, a tilt error can be actively controlled so that a laser beam is incident
on a disk in a precise direction therefore improving the qualities of recording
and reproducing data. In addition, tilt control is performed by using a focus adjustment
mechanism so that an additional mechanism to control tilt is not required. As a
result, the size and weight of the apparatus to drive the objective lens of the
optical pickup are reduced.
