HEAD RANGE CONTROLLED JUMPING

摘要

A record carrier has pattern of substantially parallel tracks constituting a data area, and a first and second boundary mark on predefined transverse positions bordering the data area. An optical disc drive scans the record carrier via a beam of radiation (24) from a head (22). The device has a control unit for determining a position of a selected track, and a tracking system for positioning the head on the selected track via a jump by a motor (40) that moves the head transverse to the tracks. The device has a head range unit (32) for detecting the boundary marks via the beam and controlling the motor for limiting said transverse movement of the head to a head range corresponding to the data area bordered by the boundary marks. Hence the motor is stopped (48) to prevent the head from exceeding head range corresponding to the data area without position sensors or mechanical elements. ® KIPO & WIPO 2007