METHOD AND DEVICE FOR DISPLACING OPTICAL HEAD IN SEARCHING FOR TRACK ON DATA MEDIUM (ALTERNATIVES) Russian patent published in 2003 - IPC

FIELD: optical systems; using optical heads for searching tracks in optical system. SUBSTANCE: method designed for displacing optical head from initial track to desired one on data medium involves determination of integer number of tracks to be crossed and optical head displacement to desired track. Light reflection factor is measured and tracking error signal is generated on its basis. Tracking signal error has indicators of both true and false crosstrackings. Data display signal generated in response to reflection factor obtained has display points corresponding to false crosstracking indicators. Number of counted tracks increases for each true crosstracking indicator and optical head stops when number of counted tracks equals full number of tracks to be crossed. As an alternative tracks counting signal is generated from tracking error signal and data indicator signal. Tracks counting signal indicates crosstrackings corresponding to true crosstracking indicator in tracking error signal. Device implementing proposed method has transducer for measuring data medium light reflection factor, tracking error signal generator for producing data signal, crosstracking signal generator responding to tracking error signal, and track/disable status selector responding to data signal and making crosstracking signal generator produce crosstracking signal without false crosstracking indicator basing on tracking error signal. EFFECT: enhanced effectiveness of searching for desired track. 12 cl, 7 dwg