Servo positioning control system for a data storage apparatus
AssigneeMemorex Corporation
InventorAndrew M. Rose
Life of this patent
Estimating the term…
Abstract
A servo system in a disc drive for accessing and maintaining selected data tracks on a stack of discs has a first continuous position signal derived from a pre-recorded surface and a second position signal derived from servo information in sectors of the other discs. The first and second position signals are combined to form a hybrid signal to control the actuators. The hybrid signal is the second signal when the second signal is generated. When the second signal is not generated, the hybrid signal is a modified first signal plus the last known second signal. The modified first signal is the difference between the first signal presently generated and the first signal generated when the second signal was last generated.
Claims4
A servo system in a disc drive for accessing a selected data track on a disc surface and for following said selected data track as the disc surface is rotated, wherein the disc surface having data information thereon also has servo information in sectors of said surface, said servo system having accessing means including a movable magnetic head coupled to an actuator that is responsive to a servo signal, comprising:
- means for generating a first continuous position signal;
- means for generating a second position signal, derived from servo information in sectors of said surface;
- means for forming an output signal based upon said first signal and said second signal;
- said output signal being said second signal when said second position signal is generated;
- said output signal being the sum of a modified first position signal and a stored second position signal when said second position signal is not generated;
- said modified first position signal being the difference between the first signal generated and the first signal generated when the second position signal was also generated;
- said stored second position signal being said second position signal when the second position signal was generated;
- and
- servo control circuit means for controlling the movement of said accessing means in response to said output signal.
In a servo system in a disc drive for accessing selected data tracks on disc surfaces and for following selected data tracks as the disc surfaces are rotated, one of such disc surfaces being dedicated to servo information, and each of the other disc surfaces having data information and servo information in sectors, said servo system having accessing means including movable magnetic heads coupled to an actuator that is responsive to servo signals, first generating means for generating a first continuous position signal derived from said dedicated servo disc surface, second generating means for generating a second position signal derived from servo information in sectors of each of said other disc surfaces, and servo control circuit means for controlling the movement of said accessing means in response to an output signal;
- wherein the improvement to said servo system comprises:
- means for forming said output signal based upon said first and second signals;
- said output signal being said second signal when said second position signal is generated;
- said output signal being the sum of a modified first position signal and a stored second position signal when said second position signal is not generated;
- said modified first position signal being the difference between the first signal generated and the first signal generated when the second position signal was also generated;
- said stored second position signal being said second position signal when the second position signal was generated.
Dependencies are inferred from the claim text.