Write power calibration utilizing least squares fit of read-back signals for moving media memory
US5268893A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 1991 |
| Grant date | Dec 7, 1993 |
| Priority date | — |
| Expiry date | Oct 18, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/126
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Calibration of the write signal power level applied to a transducer for marking a moving media to optimize a later recovered read-back signal is provided. An optimized read-back signal is one where the peak-to-peak amplitude of the read-back signal is maximized. The method provides marking test patterns on the recording media at a plurality of discrete, selected write signal power levels of the marking source, developing a read-back signal from the test pattern marks, correlating portions of the read-back signal with the write signal power levels and solving a relationship of the form EQU W.sub.c =W.sub.o -KB.sub.2 /2B.sub.3 where W.sub.c is the calibrated write signal power level W.sub.o is an offset write signal power level. K is a minimum differential between write signal power levels B.sub.2 and B.sub.3 are parameters derived from a least squares fit of a second order polynomial equation to data provided by correlating read-back signals with write signal power levels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.