JPS5841402A - Audio recording and playback device - Google Patents

Abstract

PURPOSE:To eliminate noise on a reproduced FM audio, by muting a reproduced audio output at head switching, in a device performing recording and reproduction of audio with a plurality of heads alternately. CONSTITUTION:Magnetism of a drum magnet 16 is detected with a drum PG head 17, a switching signal is generated 31 and a switch 20 is changed over at the time of reproduction using heads 12, 13 and a reproducing signal is given to filters 21, 24 and 27 and a dropout detection circuit 34. The switching signal 31 is given to a switching noise gate pulse generating circuit 32, a gate pulse is given to an OR circuit 33 at head switching and muting is provided for the reproduced audio of FM modulation 28 when dropout is produced to the reproduced video signal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in magnetic recording and reproducing devices for recording audio. When switching the video head or when the playback signal is affected by noise, a large amount of noise will be added to the playback audio signal, causing a very harsh sound. The object of the present invention is to eliminate the above-mentioned noise caused by a recording/reproducing device.Hereinafter, an example of the oswir according to the present invention will be explained with reference to the drawings.

Figure 1 is a block diagram showing an example of an audio recording and reproducing apparatus according to the present invention. In the figure, 1 is an input video signal, 2 is a low frequency filter, 3 is a frequency modulator, and 4 is an adder. , 5 is a bud range filter, 6 is a band converter, 7 is an input audio signal,
It is an 8-frequency modulator. 9 is a recording amplifier, 1o, 11
is an analog switch, 12 is the 10th head, 15 is wi
2 head, 14 is the head ``T^^, 15 is the video tape, 16 is a pulse generating ysopa magnet provided on the drum ^ to indicate the drum rotation speed, 17 is sensitive to the magnetism of the magnet, and the drum 2 is 18.19 is a playback amplifier, 20 is an analog converter, 2,1 is a high-pass eye #1, 22 is an FM demodulator, and 25 is an adder. 24 is a low-pass filter, 25 is a frequency lock*a.

26 is an output audio signal, 27 is a bandpass filter, 2nd is an FM converter, 29 is an electronic listening circuit according to the present invention, 60 is a reproduction amplifier, 31 is a head switching signal generation circuit, and 62 is a switcher noise gate. Pulse generation circuit, 55 is an OR circuit, 54 is a drop error 1 detector, 3
5 indicates an output audio signal.

Next, the operation of this embodiment will be explained.

At the time of recording, analog switches 10 and 11 are both set to record@(RHO). The input video signal 1 is transmitted to boots 2 and 5, and the luminance signal is extracted by the low-pass filter of 2, and the frequency lock 116+! 1 is added to the frequency modulated edge summation 1ii4. On the other hand, the color signal of the video signal is extracted by a bandpass filter 5, converted to a low frequency by a band conversion tlj6, and then added to an adder 4. Audio input signal 7 is frequency lock WaS
After being modulated by the signal, it is also added to the adder 4. addition 81
The output of 4 is amplified by the recording amplifier 9, and the output of 4 is amplified by the recording amplifier 9.
10.11, the signal passed through the analog switch 10 is recorded by the head 12 on the Qi 115, passed through the analog switch 11, and recorded on the tape 15 by the head 15. The frequency component of the signal during recording is approximately 2gIK.
As shown, ◎ In other words, 56 indicates the low-frequency replaced color signal component, 57 indicates the frequency-modulated audio signal component, and 58 indicates the frequency-modulated luminance signal component. 〇 During playback, the analog switch 10 .11 is on the AKPLAY side
It's on. First head 12 and vote 20 from tape 15
The signal reproduced by the analog switch 15 then passes through the analog switch 10, 11, is amplified by the reproduction amplifier 1B, 19, and is transmitted to the T-nerg suite 20.The signal that has passed through the analog switch 20 is filtered through the filters 21, 24, 27. and dropout detection 1154, respectively. The frequency-modulated luminance signal that has passed through the high-pass filter #21 is demodulated to FM@$1 in the demodulator 8122 and added to the adder 25.It also passes through the low-pass filter #-24 for low frequency conversion. The color signal thus obtained is converted to its original high frequency by an on-board converter 25, and added to an adder 23, so that 26 video signals are obtained as its output. The frequency-modulated audio signal that has passed through the bandpass filter 27 is WM@@@2B and transmitted to the electronic tuning circuit 29.
The 00tH force is transmitted to the dope γ) detection [5"4,
When a dropout is detected from 34, it outputs an output to OR @ road 5S.
The playback amplifier 50't'jlli generates a head switch tender signal in the head switching signal generation 111851, and when the signal is played back from the head 12, the analog switch 201CHi (II) is set to block the signal played back from the head 12. 21, 24.27.
54, and also generates a control signal to be transmitted to the head 15.
When playing the signal from the analog switch 20*0
H2flltC to generate a control signal so as to transmit the signal reproduced from the head 13 to the boot stock 21°24.27.54. In addition, the output of the head switching signal generation circuit O is transmitted to the sweet tender noise game F bus generation circuit 52, which generates a gate pulse only when switching heads.
Tell EIIF Road 55. The output of the OR circuit controls the 2qot engineer circuit so that it becomes tK-type 11 when the head is switched and when a dropout occurs in the reproduced video signal. 2? 5 from a output
5 (A D audio signal is obtained.) According to all of the above, according to the present invention, in the audio recording and reproducing device f, demodulation occurs at the time of head switching during regeneration or when r-tup 7?) occurs in the reproduced signal. audio signal KIR
This has the effect of eliminating the noise caused by the noise.

In addition, the head that can be invited to this event @ may be a magnetic head or an optical head. Also, the recording method is Pekarus Co., Ltd.
Of course, it is not limited to.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of an implementation circuit block of the present invention, and FIG. 2 is a diagram showing frequency components during recording of the present invention.
−・・・・Mates tend noise gate pulse emission j [road,
54@...Drop Ala) detection circuit, 5!1...
lOR game), 29...0@#lnitei/da circuit 0 Patent applicant Nakayano Y Co., Ltd.

Claims (1)

[Claims] (1) In a device that records and reproduces audio alternately using a plurality of heads, when the head O is switched, the reproduced audio output Ke
1. An audio recording and reproducing device characterized by having an lx-ning device that performs a nying. (2) The lx-tyl device is configured to apply a power reducer to the reproduced audio output even when a dropout of the reproduced output from the head is detected. 1) The audio recording and reproducing device described in item 1).