Controlling the trace of a rotary head
US4443823A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 3, 1981 |
| Grant date | Apr 17, 1984 |
| Priority date | — |
| Expiry date | Nov 3, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B27/024
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The position of a rotary head mounted on a deflection device is controlled as the head scans successive tracks on a record medium. Tracking drive signals are generated as a function of the deviation of the head relative to a track scanned thereby. The tracking drive signal is sampled at successive locations along the trace. Previously stored samples are compared to the successively produced samples, and any difference is used to correct the stored sample by a predetermined amount irrespective of the actual difference. Hence, the stored samples gradually are corrected to represent the configuration of the tracks scanned by the rotary head. When the head reproduces signals from the record medium, the generated tracking drive signals are used to control the deflection device so as to make the head coincident with the track being scanned thereby. When the head is used to record signals, the stored samples are used to control the deflection device before such samples are corrected. For recording the stored samples may be compared to reference samples, and gradually are corrected to conform to the reference samples, and used to control the deflection device so that the traces gradually c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.