Write synchronization in bit patterned media using auxiliary read head
View Patent ↗A method for recording data to a magnetic media while simultaneously reading sync and or servo data with reduced noise from the write head affecting the reading of the sync and or servo data. The invention records data using a write head of a first slider and reads the sync and or servo data from a read head located on a different slider that is facing a different disk surface than the first slider. In this way, magnetic or thermal noise from the write head does not affect the reading of the sync and or servo data.
1. A magnetic data recording system, comprising:
a magnetic disk having a first surface and a second surface opposite the first surface, each surface of the magnetic disk having sync and servo information thereon;
a first magnetic slider facing the first surface of the magnetic disk and having a magnetic write element formed thereon;
a second magnetic slider facing the second surface of the magnetic disk and having a read head formed thereon for reading sync information from the second surface of the magnetic disk; and
electronics connected with the write head of the first slider and the read head of the second slider, the electronics being functional to adjust a write clock for the write element of the first slider based on the sync data read from the read head of the second slider;
wherein the electronics is further functional to compensate sync data read by the read head of the second slider based on a known phase difference between the first slider and the second slider.
2. The data recording system as in claim 1 wherein the magnetic read head of the second slider reads servo information from the second surface of the magnetic disk, and wherein the electronics are functional to determine a projected cross track excursion based on the servo information.
3. The data recording system as in claim 2 wherein electronic are further functional to invoke a write inhibit if cross track excursion exceeds a predetermined value.
4. The magnetic data recording system as in claim 1 wherein the magnetic disk is a bit patterned magnetic media.
5. A magnetic data recording system, comprising:
a disk assembly that includes a plurality of magnetic disks each having first and second surfaces, each of the disk surfaces including data tracks and a servo sector that includes sync information and servo information;
a spindle assembly that includes a plurality of sliders arranged such that each slider faces a surface of a magnetic disk of the disk assembly, each slider having a read head and a write head; and
electronics functional to write data using a write head of a first slider, and to read sync data using a read head of a second slider that is different from the first slider;
wherein the electronics are further functional to compensate the sync data read from the read head of the second slider based on a known phase difference between the first slider and the second slider.
6. The magnetic data recording system as in claim 5 , wherein the electronics are further functional to adjust a write clock of the write head of the first slider based on the sync data read from the read head of the second slide.
7. The magnetic data recording system as in claim 5 wherein the electronics are further functional to read servo data using the read head of the second slider and to generate a projected cross track excursion of the write head of the first slider based on the servo data.
8. The magnetic data recording system as in claim 7 wherein the electronics are further functional to invoke a write inhibit if the projected cross track excursion exceeds a predetermined value.
9. A method for magnetic data recording, comprising:
writing data to a first magnetic disk surface using a read head of a first slider;
reading sync information from second magnetic disk surface using a magnetic read head of a second slider; and
adjusting a write clock of the writing by the write head of the first slider based on the sync data read by the read head of the second slider;
wherein the reading of sync data by the read head of the second slider is performed while the writing is being performed by the write head of the first slider.
10. The method as in claim 9 wherein the first magnetic disk surface and the second magnetic disk surface are surfaces of the same disk.
11. The method as in claim 9 wherein first magnetic disk surface and the second magnetic disk surface are surfaces of different magnetic disks.
12. The method as in claim 9 further comprising:
reading servo data using the read head of the second slider; and
determining a projected cross track excursion of the write head of the first slider based on the servo data read by the read head of the second slider.
13. The method as in claim 12 further comprising invoking a write inhibit if the projected cross track excursion exceeds a predetermined value.
14. The method as in claim 9 further comprising compensating the sync information based on a known phase difference between the first and second sliders.
15. The method as in claim 9 wherein the first and second disk magnetic disk surfaces are configured as bit patterned media.
16. The method as in claim 9 further comprising before writing data using the write head of the first slider, reading sync data using a read head of the first slider and adjusting the write clock for the writer based on the sync data read by the read head of the first slider.