Data access device implemented with open and closed control loops to access data stored in discrete stepwise segments

摘要

This invention discloses a data access system for access data stored on a flat medium. The data access system includes a pickup head rotating over the flat medium. The data access system further includes at least one stepping motor for discretely moving the flat medium substantially along at least one lateral direction perpendicular to a rotational axis of the pickup head. The data access system further includes a closed loop control mechanism for controlling the stepping motor for allowing the pickup head to read data from a servo segment on the flat medium. The controller further includes an open loop control mechanism for rotating the pickup head for reading data from and writing data to a data segment disposed right next to the servo segment on the flat medium.