Method and apparatus for recording and replay of digital audio data
US4620238A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1984 |
| Grant date | Oct 28, 1986 |
| Priority date | — |
| Expiry date | Aug 24, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/913
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
For both recording and replay, a digital audio tape (14) is accelerated very rapidly by a motor servo (9), motor (8) and capstan (7) so that the tape speed overshoots nominal speed range before settling back to this range in an oscillatory manner. The digital samples are recorded and replayed via a head (15), a random access memory (16) and input/output electronics (19). During recording, the store (17) is precharged by starting to write in as soon as acceleration is initiated. Read-out to the tape is initiated as soon as the tape first reaches the nominal speed range. Uniformity of samples as recorded on the tape is preserved by clocking a read address generator (21) at a rate proportional to tape speed, signaled by a tachometer (7). The write address generator is clocked at the constant sampling rate. For replay the write address generator is clocked at the tape speed rate while the read address generator (21) is clocked at the constant sample rate. Write in and read out are both initiated when the tape speed first reaches the nominal range. The addresses provided by the generators (20 and 21) are compared by a comparator (22) which provides a reference signal to the servo (9) in…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.