Patent ID: 6292318
Filing Date: 2001-09-18
Classification: G11B

Abstract:
A data recording and/or reproducing apparatus wherein a signal recording and/or reproducing head is scanned over a disc-shaped recording medium on which a positioning signal for moving said signal recording and/or reproducing head to a predetermined position is recorded along an arc of a concentric circle, comprising:means for detecting said positioning signal recorded along said arc;detecting means for detecting a circumferential position of said signal recording and/or reproducing head on said disc-shaped recording medium; andcalculating means for calculating an offset amount from a signal indicative of a detected circumferential position, whereina calculated offset amount is added to said positioning signal for controlling said signal recording and/or reproducing head for scanning along a spiral orbit over said disc-shaped recording medium, andsaid arc forming a part of said concentric circle, along which said positioning signal is recorded, has a variable radius relative to changes in said circumferential position.