Two-dimensional magnetic recording (TDMR) disk drive with varying servo track pitch
US9286926B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 2015 |
| Grant date | Mar 15, 2016 |
| Priority date | — |
| Expiry date | Aug 25, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59688
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A two-dimensional magnetic recording (TDMR) disk drive has a disk with servo tracks with a track pitch that varies across the radius of the disk. The servo track pitch (STP) is related to the cross-track spacing (CTS) of the multiple read sensors in the TDMR head structure. The CTS is given by the equation: CTS=(CTO)cos θ+(ATO)sin θ, where θ is the skew angle, and CTO is the cross-track spacing and ATO the along-the-track spacing of the read sensors at zero skew angle. The optimal variable STP profile results in track misregistration reduction because it allows each read sensor to read a different servo half-track and thus noise sources not correlated to noise sources read by the other read sensors. The servo tracks may be arranged into a plurality of annular bands, with the STP in each band being fixed and different from the STP in the other bands.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.