New Servo System for Large Capacity Floppy Disk

A low-cost, simplified continuous servo system employing a single servo signal detector is proposed. The servo record on the media consists of two frequency components, and the higher frequency component has a different phase on alternate tracks. The tracking error is detected from the phase difference of the two frequency components extracted from the single servo detector. The system was inspected using a test system with a 6 μm servo track pitch. The magnetic recording performance for floppy disks was evaluated using 7 μm and 9 μm track widths. Based on the results, a 3.5" floppy disk system with a 100 to 200 MB capacity could be developed for practical use.