Method and system for servo stripe width detection and compensation

A system for positioning a magnetic tape head adjacent a moving magnetic tape having a servo band including a first servo pattern and a second servo pattern, the system comprising:

• a tape drive for moving the magnetic tape across the magnetic tape head in a first direction;
• a servo element operably connected to the magnetic tape head for detecting a leading edge and a trailing edge of the first servo pattern, and for further detecting a leading edge and a trailing edge of the second servo pattern, the servo element being located at a predetermined transverse point on the servo band;
• a counter operably connected to the servo element for determining a first time from the leading edge of the first servo pattern to the leading edge of the second servo pattern, and for further determining a second time from the trailing edge of the first servo pattern to the trailing edge of the second servo pattern;
• and
• a control unit operably connected to the counter for determining a correction value from a difference between the first time and the second time.

A method for servo pattern compensation comprising:

• moving a magnetic tape in a first direction across a magnetic tape head, the magnetic tape having a servo band including a first servo pattern having a leading edge and a trailing edge and a second servo pattern having a leading edge and a trailing edge, the magnetic tape head having a first servo element and a second servo element;
• detecting the leading edge of the first servo pattern with the first servo element at a predetermined transverse point on the servo band;
• detecting the leading edge of the second servo pattern with the first servo element at the predetermined transverse point;
• determining a first time between the detecting the leading edge of the first servo pattern with the first servo element and the detecting the leading edge of the second servo pattern with the first servo element;
• detecting the leading edge of the first servo pattern with the second servo element at the predetermined transverse point;
• detecting the leading edge of the second servo pattern with the second servo element at the predetermined transverse point;
• determining a second time between the detecting the leading edge of the first servo pattern with the second servo element and the detecting the leading edge of the second servo pattern with the second servo element;
• determining a first difference between the first time and the second time;
• detecting the trailing edge of the first servo pattern with the second servo element at the predetermined transverse point;
• detecting the trailing edge of the second servo pattern with the second servo element at the predetermined transverse point;
• determining a third time between the detecting the trailing edge of the first servo pattern with the second servo element and the detecting the trailing edge of the second servo pattern with the second servo element;
• determining a second difference between the first time and the third time;
• and
• determining a correction value from a third difference between the second difference and the first difference.

A system for positioning a magnetic tape head adjacent a moving magnetic tape having a servo band including a first servo pattern and a second servo pattern, the system comprising:

• a tape drive for moving the magnetic tape across the magnetic tape head in a first direction;
• a first servo element operably connected to the magnetic tape head for detecting a leading edge of the first servo pattern, and for further detecting a leading edge of the second servo pattern, the servo element being located at a predetermined transverse point on the servo band;
• a second servo element operably connected to the magnetic tape head for detecting the leading edge and a trailing edge of the first servo pattern, and for further detecting the leading edge and a trailing edge of the second servo pattern, the servo element being located at the predetermined transverse point;
• a counter responsive to the first servo element for determining a first time between the leading edge of the first servo pattern to the leading edge of the second servo pattern, and further responsive to the second servo element for determining a second time from the leading edge of the first servo pattern to the leading edge of the second servo pattern, and further responsive to the second servo element for determining a third time from the trailing edge of the first servo pattern to the trailing edge of the second servo pattern;
• and
• a control unit operably connected to the counter for determining a first difference between the first time and the second time, and for further determining a second difference between the first time and the third time, and for further determining a correction value from a third difference between the second difference and the first difference.