Apparatus, system, and method for limiting frame spacing error during timing-based servo pattern fabrication
View Patent ↗An apparatus, system and method to limit frame spacing error during timing-based servo pattern fabrication. An apparatus in accordance with the invention may include a first servo write head to simultaneously write servo stripes onto a first servo frame of a magnetic tape, and a second servo write head to simultaneously write servo stripes onto a successive servo frame of the magnetic tape. The first and second servo write heads may write the stripes substantially concurrently to minimize spacing error between the frames.
1. An apparatus to limit frame spacing error during timing-based servo pattern fabrication, the apparatus comprising:
a first servo write head configured to write a first plurality of servo stripes onto a first servo frame of a magnetic tape, a servo frame comprising a portion of the magnetic tape onto which is written a pattern of servo stripes, the pattern of servo stripes repeating on each servo frame; and
a second servo write head configured to simultaneously write, substantially concurrently with the first servo write head, a second plurality of servo stripes onto a second servo frame of the magnetic tape, wherein the second servo frame sequentially follows the first servo frame and wherein the second servo write head is maintained at a predetermined distance relative to the first servo write head such that servo stripes simultaneously written onto the first and second servo frames are spaced according to the predetermined distance between the first and second servo write heads.
2. The apparatus of claim 1 , wherein each of the first and second pluralities of servo stripes comprises a pair of servo marks.
3. The apparatus of claim 2 , wherein the pair of servo stripes corresponds to consecutive servo bursts.
4. The apparatus of claim 1 , wherein each of the first and second pluralities of servo stripes comprises a quadrature burst servo pattern.
5. The apparatus of claim 1 , wherein each of the first and second servo write heads pulses a predetermined number of times to simultaneously write consecutive servo bursts onto each of the first and second servo frames.
6. The apparatus of claim 5 , wherein each of the first and second servo write heads pulses five times to simultaneously write consecutive servo bursts onto each of the first and second servo frames.
7. The apparatus of claim 5 , wherein each of the first and second servo write heads pulses four times to simultaneously write consecutive servo bursts onto each of the first and second servo frames.
8. The apparatus of claim 5 , wherein each of the first and second servo write heads incorporates longitudinal position (“LPOS”) data into at least one of the consecutive servo bursts.
9. A system to limit frame spacing error during timing-based servo pattern fabrication, the system comprising:
a tape drive configured to transport a magnetic tape from a first reel to a second reel; and
a servo pattern write module positioned intermediate the first reel and the second reel and configured to write a timing-based servo pattern onto the magnetic tape as it is transported from the first reel to the second reel, the servo pattern write module comprising:
a first servo write head configured to write a first plurality of servo stripes onto a first servo frame of the magnetic tape, a servo frame comprising a portion of the magnetic tape onto which is written a pattern of servo stripes, the pattern of servo stripes repeating on each servo frame; and
a second servo write head configured to simultaneously write, substantially concurrently with the first servo write head, a second plurality of servo stripes onto a second servo frame of the magnetic tape, wherein the second servo frame sequentially follows the first servo frame and wherein the second servo write head is maintained at a predetermined distance relative to the first servo write head such that servo stripes simultaneously written onto the first and second servo frames are spaced according to the predetermined distance between the first and second servo write heads.
10. The system of claim 9 , wherein the servo pattern write module comprises more than one first and second servo write head, each of the first and second servo write heads corresponding to a unique servo track on the magnetic tape.
11. The system of claim 10 , further comprising a tape path disposed between the first reel and the second reel to support the magnetic tape during transport.
12. The system of claim 9 , wherein the servo pattern write module pulses a predetermined number of times to simultaneously write consecutive servo bursts onto each of the first and second servo frames.
13. The system of claim 9 , further comprising a servo pattern read module comprising at least one servo read head configured to read the first and second pluralities of servo stripes on the magnetic tape.
14. The system of claim 13 , wherein the servo pattern read module is further configured to differentiate between servo stripes on the first servo frame and servo stripes on the second servo frame.
15. The system of claim 9 , further comprising a servo pattern verification module to verify the accuracy of the timing-based servo pattern generated by the servo pattern write module.
16. A system limit frame spacing error during timing-based servo pattern fabrication, the system comprising:
a tape drive configured to transport a magnetic tape from a first reel to a second reel;
a first servo write head configured to write a first plurality of servo stripes onto a first servo frame of a magnetic tape, a servo frame comprising a portion of the magnetic tape onto which is written a pattern of servo stripes, the pattern of servo stripes repeating on each servo frame; and
a second servo write head configured to simultaneously write, substantially concurrently with the first servo write head, a second plurality of servo stripes onto a second servo frame of the magnetic tape, wherein the second servo frame sequentially follows the first servo frame and wherein the second servo write head is maintained at a predetermined distance relative to the first servo write head such that servo stripes simultaneously written onto the first and second servo frames are spaced according to the predetermined distance between the first and second servo write heads;
a controller that provides a control signal to the first and second servo write heads such that each of the first and second servo write heads concurrently pulses five times to simultaneously write five consecutive servo stripes forming a five-stripe servo burst onto a first portion of each of the first and second servo frames, and such that each of the first and second servo write heads pulses four times to simultaneously write four consecutive servo stripes forming a four-stripe servo burst onto a second portion of each of the first and second servo frames.
17. The system of claim 16 , further comprising:
a servo read head that reads each of the servo stripes of the five-stripe servo burst and each of the servo stripes of the four-stripe servo burst; and
a verification module that verifies that the servo stripes of the five-stripe servo burst and the servo stripes of the four-stripe servo burst are accurately written and spaced.
18. A method to limit frame spacing error during timing-based servo pattern fabrication, the method comprising:
transporting a magnetic tape from a first reel to a second reel, the magnetic tape having at least one servo track;
writing with a first servo write head, while the magnetic tape is transported from the first reel to the second reel, a first plurality of servo stripes onto a first servo frame of the at least one servo track, a servo frame comprising a portion of the magnetic tape onto which is written a pattern of servo stripes, the pattern of servo stripes repeating on each servo frame; and
writing with a second servo write head, substantially simultaneously while writing the first plurality of servo stripes onto the first servo frame, a second plurality of servo stripes onto a second frame of the at least one servo track, wherein the second servo frame sequentially follows the first servo frame and wherein the second servo write head is maintained at a predetermined distance relative to the first servo write head such that servo stripes simultaneously written onto the first and second servo frames are spaced according to the predetermined distance between the first and second servo write heads.
19. The method of claim 18 , further comprising:
reading each of the first and second pluralities of servo stripes; and
verifying that each of the first and second pluralities of servo stripes are accurately written and spaced.
20. The method of claim 18 , wherein each of writing the first plurality of servo stripes and writing the second plurality of servo stripes comprises iteratively writing the first and second pluralities of servo stripes to create consecutive servo bursts in each of the first and second servo frames.