JPS59189708U

JPS59189708U - Automatic discrimination method for audio FM modulation recording signal

Info

Publication number: JPS59189708U
Application number: JP8031883U
Authority: JP
Inventors: 栄治大原
Original assignee: 株式会社東芝
Priority date: 1983-05-30
Filing date: 1983-05-30
Publication date: 1984-12-15

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of drawings]

第１図は従来のヘリカルスキャン回転ヘッドを有するＶ
ＴＲの音声再生系の一例を示した構成図、第２図は第１
図のａ点における時間軸上の再生エンベロープを示した
図、第３図は４つのキャリアの帯域ノイズを示した特性
図、第４図は第１図の再生系にて特殊再生した場合のａ
点の時間軸上のエンベロープを示した図、第５図は第１
図のｂ（又はｃ、　　ｄ、　ｅ）点の再生エンベロープ
を示した図、第６図は本考案の音声ＦＭ変調記録信号の
自動判別方式を適用したヘリカルスキャン回転ヘッドを
有するＶＴＲの音声再生系の一実施例を示した構成図、
第７図は第６図のｆ点における時間軸上のエンベロープ
を示した図、第８図は第６図の再生系において特殊再生
した場合のｆ点における時間軸上のエンベロープを示し
た図である。１、　２．　３．　４．　５・・・帯域フィルタ、１０
・・・周波数変換回路、１１・・・スイッチング回路、
１２・・・復調器、１３・・・エンベロープ検波回路。Figure 1 shows a V with a conventional helical scan rotating head.
A configuration diagram showing an example of the TR audio reproduction system, Figure 2 is the same as Figure 1.
A diagram showing the reproduction envelope on the time axis at point a in the figure, Figure 3 is a characteristic diagram showing the band noise of four carriers, and Figure 4 is a when special reproduction is performed using the reproduction system in Figure 1.
Figure 5 is a diagram showing the envelope of points on the time axis.
A diagram showing the reproduction envelope at points b (or c, d, e) in the figure, and Figure 6 shows the audio reproduction system of a VTR having a helical scan rotary head to which the automatic discrimination method for audio FM modulated recording signals of the present invention is applied. A configuration diagram showing an example of
Figure 7 is a diagram showing the envelope on the time axis at point f in Figure 6, and Figure 8 is a diagram showing the envelope on the time axis at point f when special playback is performed in the playback system in Figure 6. be. 1, 2. 3. 4. 5...Band filter, 10
...Frequency conversion circuit, 11...Switching circuit,
12... Demodulator, 13... Envelope detection circuit.

Claims

[Scope of utility model registration request]

In a method for determining the presence or absence of an audio recording signal of a helical scan VTR in which audio FM modulation is recorded using a rotating head, a plurality of audio signals are obtained by passing the reproduced audio envelope separated from the reproduced envelope from the rotating head through each band filter. Using two carriers in the carriers, one carrier is frequency-converted to match the frequency of the other carrier, and then both carriers are extracted continuously by a switching circuit without interruption on the time axis.
An automatic discrimination method for an audio FM modulated recording signal, characterized in that the presence or absence of an audio FM modulated recording signal is determined by envelope detection of the audio FM modulated recording signal.