Information storage disk transducer position control system using a prerecorded servo pattern requiring no alignment with the storage disk
US4558383A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 1983 |
| Grant date | Dec 10, 1985 |
| Priority date | — |
| Expiry date | Jun 30, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B23/42
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An information storage disk is provided with a dense array of detectable marks. This pattern does not interfere with or use any otherwise available recording capacity of the storage medium. The marks are detected by a sensor different from any transducer used to read or write information into the storage medium. Information storage tracks are defined by the pattern rather than by any recorded information in the storage medium. In the preferred embodiment the storage medium is a conventional magnetic recording layer and the pattern of detectable marks are optically reflective or non-reflective spots overlying or underlying the magnetic storage medium. The sensor is mounted over the pattern for common movement with the storage medium transducer. As the storage disk spins, the sensor produces a signal which varies as individual marks pass by. From the sensor signal is derived a signal directly related to the rate at which marks are passing under the sensor. This mark sensing rate at which marks are passing under the sensor is proportional to the product of the linear velocity of the disk under the sensor and the density of the marks in the detection region. Each discrete information s…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.