A method and device for measuring the tilt in an optical disc drive (1) is
disclosed. The optical disc drive (1) comprises two lasers (31, 41)
generating two laser beams (32, 42) having mutually different optical
characteristics. One of these laser beams (32) is continuously ON, and is
used for writing or reading data to or form the disc. The other laser
beam (42) is repeatedly switched ON and OFF. Tilt is measured by
comparing a normalized error signal (RES(ON)) during the ON-phase (TON)
with a normalized error signal (RES(OFF)) during the OFF-phase.