Sony Corporation

Shoji Hagita

Shinji Kakuyama

Takanori Maruichi

Drop-outs are detected and compensated for in an apparatus for reproducing video and audio signals that have been recorded as first and second mixed signals in adjacent first and second parallel tracks, respectively, on a magnetic record medium such as a tape and in which each of the mixed signals is comprised of a video signal mixed with at least one frequency modulated audio signal, in the case of monaural, having a respective carrier frequency. The recorded mixed signals are reproduced by two magnetic heads that scan the adjacent first and second tracks to reproduce alternately the mixed signals recorded thereon, and drop-outs are detected in the reproduced signals. The audio signals are separated from the reproduced mixed signals, frequency demodulated and combined to form a substantially continuous or reconstituted demodulated audio signal. A compensator is provided in the demodulated audio line and is responsive to the detection of drop-outs by a detector therefor to produce a substantially continuous demodulated audio signal, in which drop-outs are compensated. A second dropout compensator is provided for compensating the video signal for dropouts and the second dropout compensator is located in the line carrying the luminance component of the video signal and is responsive to the original drop-out detector output derived from the reproduced signals. The drop-out detector may be responsive to the reproduced mixed signals either prior to combining into a signal or subsequent to such combining. Still further, the drop-out detection may be responsive to drop-outs in the frequency modulated audio signals after the latter have been separated from the reproduced mixed signals.

Apparatus for detecting and compensating drop-outs in an audio and video

For providing high-quality reproduction of audio in a video tape recorder (VTR), the video and audio signals are recorded as first and second mixed signals in successive alternately arranged adjacent first and second parallel record tracks, respectively, extending obliquely on a magnetic record tape, with the first and second mixed signals being comprised of respective carriers of different frequencies which are modulated by an audio signal to constitute respective FM audio signals mixed with a video signal. In a normal reproducing mode of the VTR, in which the tape is advanced at a normal speed corresponding to that used for recording, magnetic heads scan substantially along the adjacent first and second record tracks in succession for alternately reproducing the first and second mixed signals therefrom, the FM audio signals are separated from the reproduced mixed signals and then are demodulated for obtaining therefrom respective alternately reproduced portions of the audio signal, and the alternately reproduced portions are sequentially combined to reconstitute the audio signal therefrom. In another reproducing mode in which the tape is advanced at other than its normal speed, the heads scan imperfectly along the record tracks so that the mixed signals are reproduced therefrom with noise particularly when the heads are situated adjacent end portions of the tracks being imperfectly scanned, and a noise compensating circuit is operative, in that other reproducing mode, for removing the noise from the reconstituted audio signal.

Growing community of inventors

Kanagawa, Japan

Shoji Hagita