JPS59161771U

JPS59161771U - Dropout marking device

Info

Publication number: JPS59161771U
Application number: JP5534383U
Authority: JP
Inventors: 政博由田; 伸次室
Original assignee: 帝人株式会社
Priority date: 1983-04-15
Filing date: 1983-04-15
Publication date: 1984-10-30

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 the drawing]

第１図はドロップアウトを含む映像再生信号の図形、第
２図はドロップアウト検出およびマーキング回路の従来
装置である。第３図はその動作説明のためぬ各部の波形
を示す。第４図は本考案の実施例を示すマーキング方式
を示す回路図である。また第５図は従来例き実施例のマーキング信号およびビ
ッタ−図形の比較である。図面において、１・・・記録再生ヘッド、２および３・
・・記録再生切替ヘッド、４・・・再生増幅回路、５・
・・記録増幅回路、６・・・ドロップアウト検出装置、
　−９・・・パルス発生回路、８・・・高周波ゲート発
振回路、Ａ・・・１トラック分のビッタ−図形の従来例
、またＢ・・・１トラック分のビッタ−図形の実施例で
ある。FIG. 1 shows a diagram of a video playback signal including dropouts, and FIG. 2 shows a conventional dropout detection and marking circuit. FIG. 3 shows waveforms of various parts for the purpose of explaining its operation. FIG. 4 is a circuit diagram showing a marking method according to an embodiment of the present invention. Further, FIG. 5 is a comparison of marking signals and bitter figures of the conventional example and the embodiment. In the drawings, 1... recording/reproducing head, 2 and 3...
...recording/reproduction switching head, 4...reproduction amplification circuit, 5.
... Recording amplification circuit, 6... Dropout detection device,
-9...Pulse generation circuit, 8...High frequency gate oscillation circuit, A...Conventional example of bitter figure for one track, and B...Example of bitter figure for one track. .

Claims

[Scope of utility model registration request]

, a video signal reproducing device equipped with a video recording head capable of reproducing information recorded on a magnetic tape as a frequency modulation signal or a phase modulation signal, and a dropout detection device capable of detecting a dropout of a set level or higher in the reproduced video signal. A device, a pulse generation circuit capable of shaping a dropout signal to input the waveform-shaped drop alert signal, means for operating a recording/reproduction switch using the output pulse of the pulse generation circuit as a marking signal, and a gate for the marking signal. A high-frequency gate oscillation circuit is input, and an output signal of the high-frequency gate oscillation circuit is fed back to the video recording head to demagnetize the recorded information on the magnetic tape near the position indicating the dropout with AC demagnetization according to the pulse width of the marking signal. A dropout marking device capable of identifying the position where a dropout exceeding a set level occurs on a magnetic tape.