Method and apparatus for PCM recording and reproducing an audio signal having an asynchronous relation between the sampling frequency for the audio signal and the rotation frequency of a rotary head scanner
US4937686A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1986 |
| Grant date | Jun 26, 1990 |
| Priority date | — |
| Expiry date | Nov 13, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2020/1087
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A PCM audio signal recording and reproducing apparatus samples an audio signal with a sampling frequency having an asynchronous relation to a field frequency of a video signal; converts it to a PCM signal, adds error detection/correction data to a predetermined number of PCM data, forms a data frame by those signals, modulates it in accordance with a predetermined modulation system, and records the audio signal together with the video signal or just the audio signal on a record medium by using a rotary head type scanner which is controlled so as to have a synchronous relation to the field frequency of the video signal. A digital signal processing circuit having a memory of a predetermined capacity is provided, and the number of digital data to be recorded in one data frame is varied in accordance with a difference between the number of input data of the digital audio signal to the digital signal processing circuit and the number of output data supplied to the record medium for recording. In the recording mode, the PCM audio signal is sectioned into blocks, a data block address signal is added to each block to indicate a relative order of a block to the other blocks and is completel…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.