Radial self-propagation pattern generation for disk file servowriting

In a servowriting system for implementation in a storage device including a storage medium and a transducer positionable relative to the storage medium under the control of a servo system for writing position information to the medium, the storage device subsystem having a set of operating parameters, a method for reducing input noise introduced into written position information in a servowriting process, caused by at least one of said operating parameters, comprising the steps of:

• writing first servo position information comprising at least one track, each track having a sector including position information, as part of the servowriting process;
• measuring an indicium of said input noise introduced into the first written position information;
• using the measured indicium to optimize at least one operating parameter of the servowriting system, whereby introduction of said input noise into subsequently written position information in the servowriting process is reduced;
• repeating the writing and measuring steps for a plurality of combinations of write frequency and write current values;
• and
• selecting as the at least one optimized parameter the combination for which the predetermined indicium has the lowest value, so as to reduce said input noise in the servowriting process.

In a servowriting system for implementation in a storage device including a storage medium and a transducer positionable relative to the storage medium under the control of a servo system for writing position information to the medium, the storage device subsystem having a set of operating parameters, a method for reducing input noise introduced into written position information in a servowriting process, caused by at least one of said operating parameters, comprising the steps of:

• writing first servo position information comprising at least one track, each track having a sector including position information, as part of the servowriting process;
• measuring an indicium of said input noise introduced into the first written position information, wherein measuring the indicium further comprises the steps of:
• sensing the first servo position information and producing therefrom a position error signal having a magnitude;
• and
• determining a difference between the position error signal magnitude and a nominal magnitude;
• and
• using the measured indicium to optimize at least one operating parameter of the servowriting system, so as to reduce said input noise in the servowriting process, wherein the servowriting system has a measurable closed loop response, and wherein measuring the indicium further comprises the steps of:
• measuring the closed loop response, CL, of the servo system;
• and
• dividing the magnitude difference by (1−CL).

In a self-servowriting system for implementation in a storage device including a storage medium and a transducer positionable relative to the storage medium under the control of a servo system for writing position information to the medium, the self-servowriting system having a set of operating parameters, a method for reducing sources of error introduced into written position information, comprising the steps of:

• writing first servo position information;
• measuring an indicium of error introduced into the first written position information;
• using the measured indicium to optimize at least one operating parameter of the self-servowriting system, whereby introduction of error into subsequently written position information is reduced;
• writing second position information;
• servowriting while sensing the second position information and producing therefrom a position error signal having a magnitude;
• if the magnitude of the position error signal exceeds a threshold magnitude, temporarily halting servowriting while continuing to sense the second position information until the position error signal produced is determined to be below the threshold magnitude.

In a servowriting system for implementation in a storage device including a storage medium and a transducer positionable relative to the storage medium under the control of a servo system for writing position information to the medium, the storage device subsystem having a set of operating parameters, a method for reducing input noise introduced into written position information in a servowriting process, caused by at least one of said operating parameters, comprising the steps of:

• writing first servo position information comprising at least one track, each track having a sector including position information, as part of the servowriting process;
• measuring an indicium of said input noise introduced into the first written position information;
• using the measured indicium to optimize at least one operating parameter of the servowriting system, whereby introduction of said input noise into subsequently written position information is reduced in the servowriting process;
• repeating the writing and measuring steps for a plurality of different RPM's;
• and
• selecting as the optimized parameter the one of the plurality of RPM's for which the predetermined indicium has the lowest value, so as to reduce said input noise in the servowriting process.

In a servowriting system for implementation in a storage device including a storage medium and a transducer positionable relative to the storage medium under the control of a servo system for writing position information to the medium, the servowriting system having a set of operating parameters, a method for reducing sources of error introduced into written position information, comprising the steps of:

• writing first servo position information;
• measuring an indicium of error introduced into the first written position information;
• using the measured indicium to optimize at least one operating parameter of the servowriting system, whereby introduction of error into subsequently written position information is reduced;
• writing second position information;
• servowriting while sensing the second position information and producing therefrom a position error signal having a magnitude;
• if the magnitude of the position error signal exceeds a threshold magnitude, temporarily halting servowriting while continuing to sense the second position information until the position error signal produced is determined to be below the threshold magnitude.