Digital signal magnetic recording/reproducing apparatus using amplitude phase shift keying and frequency-multiplexing
US5402272A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 1994 |
| Grant date | Mar 28, 1995 |
| Priority date | — |
| Expiry date | Jan 7, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital signal magnetic recording/reproducing apparatus subjects a digital signal to a digital amplitude phase shift keying and records and reproduces the modulated signal thus obtained on a magnetic recording medium. Use of the digital amplitude phase shift keying technique makes it possible to remove the direct-current component in the recording signals, and to improve the utilization efficiency of the recording frequency band, thus making high density recording possible. In addition, since a plurality of modulated signals are frequency-multiplexed and recorded, almost the entire frequency band recordable on a magnetic recording medium can be utilized, resulting in an increase in recording density. Further in addition, a pilot signal produced by frequency-converting a carrier is frequency-multiplexed with a modulated signal and recorded and reproduced and the carrier is reproduced from the reproduced pilot signal, so that a redundant part for reproducing the carrier is not necessary.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.