Technique for signal and transducer alignment in a tape drive
View Patent ↗In an embodiment, a method is provided for improving signal and transducer alignment in a magnetic tape drive. The method includes writing a first track and a second track to a tape. Each track has an associated track characteristic, which may include fundamental frequency and test binary pattern, among other characteristics. The tracks are adjacent and substantially parallel to one another, and each track has a differing track characteristic value. Each track is read at multiple tracking positions to collect values corresponding to each position. An optimal offset is determined based on the collected values and the corresponding tracking positions. In another embodiment, a magnetic tape drive includes a data reader, a data writer, a processor, and a computer readable medium. The medium has stored instructions, executable by the processor, for carrying out the described method.
1. A method for improving signal and transducer alignment in a magnetic tape drive, the method comprising:
writing a first track and a second track to a tape, each track having a track characteristic, wherein the tracks are adjacent and substantially parallel to one another and each track has a differing track characteristic value;
reading each track at multiple tracking positions to collect values corresponding to each tracking position; and
determining an optimal offset position based on the collected values and the corresponding tracking positions for the first and second tracks, the optimal offset position being determined so as to make both the first track and the second track readable.
2. The method of claim 1 comprising offsetting the tape during a subsequent write or read operation according to the optimal offset position.
3. The method of claim 1 wherein the track characteristic is selected from the group consisting of fundamental frequency and binary pattern.
4. The method of claim 3 wherein each track is characterized by a binary pattern.
5. The method of claim 3 wherein two tracks having differing fundamental frequency track characteristics differ by at least 1 MHz.
6. The method of claim 1 wherein a servo track is written to the tape, a servo reader is aligned with the servo track, and the step of writing is performed by writing each track to one of a plurality of offset locations from the servo track.
7. The method of claim 1 wherein reading each track comprises:
determining the amplitude of the first track at each tracking position, thereby defining a first set of amplitude values; and
determining the amplitude of the second track at each tracking position, thereby defining a second set of amplitude values.
8. The method of claim 7 comprising comparing first set amplitude values to second set amplitude values for corresponding tracking positions, and selecting as the optimal offset position the tracking position that satisfies a prescribed relationship between the amplitude value sets.
9. The method of claim 8 wherein, for a given tracking position, the prescribed relationship between the amplitude value sets is satisfied by maximizing or minimizing the ratio between the corresponding first track amplitude value and the corresponding second track amplitude value relative to other pairs of first and second track amplitude values.
10. The method of claim 1 wherein the steps of writing, reading, and determining are performed during manufacture of the tape drive.
11. The method of claim 1 wherein the steps of writing, reading, and determining are performed during tape drive operations.
12. A magnetic tape drive comprising:
a data reader;
a data writer;
a processor; and
a computer readable medium including stored processor-executable instructions for:
writing a first track and a second track to a tape, each track having a track characteristic, wherein the tracks are adjacent and substantially parallel to one another and each track has a differing track characteristic value;
reading each track at multiple tracking positions to collect values corresponding to each tracking position;
determining an optimal offset position based on the collected values and the corresponding tracking positions for the first and second tracks, the optimal offset position being determined so as to make both the first track and the second track readable; and
storing the optimal offset position to the medium.
13. The tape drive of claim 12 wherein the medium includes a stored processor-executable instruction for offsetting the tape during a subsequent write or read operation according to the optimal offset position.
14. The tape drive of claim 13 wherein the instructions for writing, reading, determining, storing, and offsetting are performed during tape drive operations.
15. The tape drive of claim 12 wherein the track characteristic is selected from the group consisting of fundamental frequency and test binary pattern.
16. The tape drive of claim 12 wherein the instruction for reading comprises instructions for:
determining the amplitude of the first track at each tracking position, thereby defining a first set of amplitude values; and
determining the amplitude of the second track at each tracking position, thereby defining a second set of amplitude values.
17. The tape drive of claim 16 wherein the medium includes a stored processor-executable instruction for comparing the first amplitude value set to the second amplitude value set for corresponding tracking positions and selecting as the optimal offset position the tracking position that satisfies a prescribed relationship between the amplitude value sets.