o,k,m,/m recording code
US6587977B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 1999 |
| Grant date | Jul 1, 2003 |
| Priority date | — |
| Expiry date | Dec 6, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/1426
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for encoding data to meet a maximum run length limitation is disclosed. In one embodiment, the method comprises the steps of: (1) providing user data that includes a plurality of bits, wherein said bits have a value of 1 or 0; (2) performing an ECC computation on said plurality of user data bits to add ECC symbols in the form of a plurality of ECC bits; (3) randomizing the plurality of user data bits and said plurality of ECC bits; (4) analyzing said randomized user data bits and ECC bits to determine whether a number of consecutive bits have a common value; and, (5) inverting the value of a bit, when the number of consecutive bits having a common value exceeds the maximum run length limitation. Subsequently, representations of each of the randomized user bits and ECC bits, including any inverted bits, are stored onto a disk surface as magnetic-polarity transitions. Later, the stored magnetic-polarity transitions are read from the disk surface and the randomized user bits and ECC bits, including any inverted bits, are recovered. The randomized user bits and ECC bits are derandomized, and the value of the inverted bit is inverted to its original value using the ECC computat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.