Method and apparatus for reading a disk
US4618898A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1984 |
| Grant date | Oct 21, 1986 |
| Priority date | — |
| Expiry date | Dec 20, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2508
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for reading data from a disk having missing or unreadable field address marks. Expected address marks are searched for within a time window which is generated using a counter. When an expected address mark is generated at any time within the time window, the counter is set or reset to generate another time window within which the next address mark is expected to occur. By starting or restarting the counter each time an expected address mark is detected the effects of variations in spindle speed which occur prior to the detection of the address mark are eliminated, thus increasing the probability that readable address marks will be detected within a time window.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.