Burst Data for Head Positioning
Original Publication Date: 1988-Aug-01
Included in the Prior Art Database: 2005-Feb-15
This article describes a method to improve the linear range of burst pattern used in a hard disk drive. In a standard hard disk utilizing index gap as servo data area, the typical servo pattern is shown in Fig. 1. Fig. 1(a) shows the relation between the servo data and the center of a track. The difference between magnitudes of burst A and B is used to generate position error signal. The magnitude of the burst signal can be obtained by peak detectors or integrators. In Fig. 1(b), the linear range of the position error signal is shown as 'D0'. Then, from the Fig. 1(b), D0 is D0 = (gap length) - (track width) / 2 The relation between the gap length and the track length is (gap length) = (track width) * b where b = 0.7 in the case of a normal file. Thus, D0 is D0 = (b - 0.