Magnetic recording disk drive with patterned media and circuit for generating timing pulses from the pattern
US7324294B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 29, 2004 |
| Grant date | Jan 29, 2008 |
| Priority date | — |
| Expiry date | Nov 3, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/252
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording disk drive has a patterned magnetic recording disk with data blocks of magnetizable material separated by nonmagnetic regions, a read head for reading the magnetized data blocks and generating a readback signal, and a timing circuitry that generates from the readback signal a series of timing pulses. When the read head is over a nonmagnetic region the readback signal is significantly reduced, and this signal reduction is detectable to determine the position of the nonmagnetic regions. The timing circuitry includes a rectifier that rectifies the readback signal, a highpass filter that filters the rectified signal at the frequency of the data blocks, and a peak detector that detects the peaks of the filtered signal and generates a series of timing pulses, each pulse representing a nonmagnetic region. The timing pulses can be used for marking the bit boundaries in the digital data sequence that is output from the read channel or as the write clock signal to the write head for magnetizing the data blocks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.