| 摘要 |
<p>A quadrature based embedded servo control system is provided to realize a high track density, high-performance hard disk drive system (10). Each data sector includes a gray code field spanning the entire width of the data track and a quad-servo burst pattern having first, second, third, and fourth servo burst fields distributed along the length of a portion of the data sector. The center point of the first, second, third, and fourth servo bursts are sequentially offset from the adjacent burst by a radial distance equivalent to one-half of the data track width. The quad-servo burst pattern is used with a track-following algorithm based on the quadrature value of (A + B) - (C + D) to obtain a substantially increased servo lock range. A second gray code field extending substantially the width of the data track and second quad-servo burst pattern substantially identical to the first is provided near a mid-point in the data portion of the data sector to increase the servoing information sample rate and accuracy, thereby permitting substantially increased data track densities to be utilized.</p> |
