Atomic force microscopy data storage systems

摘要

A high density data storage system based on atomic force microscopy uses a tracking servo system based on timing or tracking lines (70,71,72) placed on the data storage medium. In a disk drive embodiment with a read-only disk (10), the timing or tracking lines are formed in sets of triplets with the sets being circumferentially spaced around the disk (10) and interspersed with the surface incongruences (12) that form the machine-readable data features. The data tracks (60,61,62) and circumferentially-spaced sets of tracking lines are grouped into radially-spaced bands on the disk. Each set of tracking lines includes at least two lines, one of which (70) is a nonradial line. A separate set of identification (ID) marks associated with each data band are used to initiate a timing gate during which the tracking lines are expected to be detected. A comparison of the time between the detection of at least two of the lines with a predetermined target time is used to generate a tracking error signal (TES) that is used to control the actuator (22) and move the stylus (19) back on track or to the desired track.