Patent ID: 6134072
Filing Date: 2000-10-17
Classification: G11B

Abstract:
A tracking method for enabling a first read head and a second read head mounted on a drum of a helical scan tape drive to read non-native helical stripes recorded on a tape by another helical scan tape drive, the non-native helical stripes being wider than native stripes read by the first read head and the second read head, the method comprising:transporting the tape at a linear velocity whereby the first head traverses a first non-native stripe and the second head traverses a second non-native stripe;obtaining a first read signal from the first non-native stripe using the first read head and obtaining a second read signal from the second non-native stripe using the second read head;if the first read signal is not less than a first predetermined threshold and the second read signal is not less than a second predetermined threshold, determining a correction value by:(1) interpreting any signal loss from the first read head as meaning that the first read head and the second read head are positioned too far to a first direction;(2) interpreting any signal loss from the second read head as meaning that the first read head and the second read head are positioned too far to a second direction;if the first read signal is less than the first predetermined threshold, adding to the correction value any signal loss from the second read head with it's sign inverted; andif the second read signal is less than the second predetermined threshold, adding to the correction value any signal loss from the first read head with it's sign inverted; andusing the correction value to control a relative position of the first read head and the second read head over the non-native helical stripes.