Tilt which is inclination of a normal of optical disk relative to optical axis
of optical head is corrected with a liquid crystal element. In a driver for the
liquid crystal element, a periodic waveform generator generates periodic waveform
and an inverting element inverts the periodic waveform. The periodic waveform and
the inverted waveform are connected to two ends of a potential divider which provides
partial voltages. The periodic waveform is connected to a common electrode of the
liquid crystal element, and the partial voltages of the potential divider are connected
to electrodes opposing the common electrode. A structure of a driver circuit for
each direction is simple. Tilt in a plurality of directions can be performed independently
of each other. Spherical aberration is also corrected. When the liquid crystal
element is mounted to a fixed component, deterioration due to jitters is reduced.