OPTICAL MEMORY SYSTEM HAVING IMPROVED TRACK FOLLOWING AND SEEKING CAPABILITIES

摘要

Optical Memory System Having Improved Track Following and Seeking Capabilities A high density optical data storage system employing a laser beam for reading data in a track on a rotating optical disk containing a large number of closely spaced concentric tracks. The system provides for track following as well as long and short seek track moving operations. Track following and short seeking operations share the use of a galvanometer-controlled mirror in the path of the beam, while long seek operations are performed using a positioning motor which is also used during track following to reduce the deflection required to be provided by the galvanometer mirror. The short seek operation uses a specially shaped doublet waveform comprised of opposite polarity pulses chosen based on the number of tracks to be moved and the mechanical characteristics of the system.