JP2563815Y2 - Video tape recorder signal switching circuit - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to re-recording by a fixed head of a Hi-Fi video tape recorder (HiFi VTR), so-called after recording.

[0002]

2. Description of the Related Art HiFi VTR has an audio band of about 20 k.
By the two magnetic heads and the normal manner fixed magnetic head audio AM signal provided audio FM signal H _Z to the rotary cylinder, a method for recording a predetermined sound signal to a predetermined track of the magnetic tape (for example, (HiFi audio is recorded on an inclined track, and normal audio is recorded on a linear track). The monitor audio output of the audio recorded on the predetermined track at the time of recording and the reproduced audio output at the time of reproduction are stereo audio of audio multiplex broadcasting by audio FM signal, HiFi audio such as bilingual, or normal audio by audio AM signal. Therefore, the audio output is conventionally selected by a manually operated audio output switch, and the audio signal processed by the audio signal processing unit is switched and output based on the audio output control signal from the audio output switch. The method of monitoring output from the terminal has been awarded.

FIG. 3 shows a conventional audio output switching circuit using a HiFi VTR.

In the figure, (1) and (1) are rotary heads for reproducing HiFi audio, (2) are fixed heads for reproducing normal audio, and (3) are external audio such as microphones for inputting normal audio. The input terminal, (4) performs signal processing on the audio input from the external audio input terminal and the reproduced audio input from the respective heads according to the respective audio signals,
An audio signal processing unit for selecting the plurality of audio signals subjected to the signal processing based on an audio output control signal and outputting the selected audio signal, (5) and (6) output from the audio signal processing unit. Output terminal for monitoring and outputting audio signals.

In the audio signal processing section, as shown in a truth table of audio output control in audio multiplex broadcasting shown in FIG. 4, a manually operated audio output switch (not shown) is used in accordance with the state of HiFi audio. Output switching control signals, that is, an output switching A signal (7) and an output switching B signal (8).
The audio output is selectively controlled by a combination of the respective signal levels of the above, and the selected audio signal is output to the output terminal (5),
Output from (6).

When re-recording normal sound by a fixed head, so-called after-recording (hereinafter referred to as "after-recording"), the signal becomes high by an after-recording signal (9) created by a manually operated after-recording button switch (not shown). The level is input to the audio signal processing unit. And
As for each audio signal in the audio signal processing unit at the time of the after-recording, the HiFi audio by the rotary head is processed in the reproduction mode, and the normal audio by the fixed head is switched to the signal processing in the recording mode.

For example, when dubbing normal audio on a linear track of a magnetic tape on which HiFi audio and normal audio are recorded, the dubbing standby state in which the above-described dubbing button switch is operated is a state in which the mechanical system of the VTR is in a pause state of reproduction. The signal processing of the audio signal processing unit at this time is such that each audio signal processing output in the audio signal processing unit is automatically muted because the audio input from each of the heads has no signal, and The normal sound input from the external sound input terminal is monitored and output from the signal processing unit.

After that, when the post-recording button switch is operated again to enter the post-recording operation state, the mechanism of the VTR shifts to the reproduction state, muting of the respective audio signal processing outputs in the audio signal processing section is released, and the audio signal From the processing unit, the sound selected and controlled based on the output switching control signal is monitored and output.

[0009]

That is, in the conventional method, the output switching control of the monitor output sound is controlled so that the HiFi sound having a good sound characteristic is always output with priority. As for the monitor output, the monitor output of the normal sound for re-recording by the fixed head is initialized when the post-recording standby state is released and the post-recording operation state is entered, and the HiFi sound based on the output switching control signal is output from the sound signal processing unit. Monitor output.

Therefore, in order to monitor and output a normal audio input, for example, a microphone audio input, which has been monitored in the after-recording standby state, the normal audio is output based on the output switching control signal shown in FIG. As described above, there is a disadvantage that monitoring cannot be performed unless the manual operation voice output switch is switched, and the operation of changing the voice output switch at the time of post-recording is inconvenient.

[0011]

According to the present invention, a HiF capable of reproducing an audio multiplexed signal and an audio signal recorded at a predetermined recording position on a magnetic tape by a rotating head and a fixed head and enabling after-recording by the fixed head.
In the iVTR, a rotary head for reproducing HiFi audio, a fixed head for reproducing normal audio, an external audio input terminal for inputting normal audio such as a microphone, a normal audio input from the input terminal and the respective normal audio Performing signal processing on the reproduced sound input from the head and selecting the signal-processed sound signal based on the sound output control signal;
An audio signal processing unit for monitoring and outputting the selected audio signal, wherein at the time of after-recording, the same audio signal as the normal audio recorded by the fixed head is automatically monitored and output.

[0012]

According to the present invention, the signal switching for setting the output switching control signal input to the audio signal processing unit to the level for switching to the normal audio by the after-recording signal generated by the after-recording button switch in the above configuration. Since the circuit is provided, the monitor output at the time of post-recording is switched to the normal sound to be re-recorded by the fixed head.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to the audio output switching circuit of the present invention shown in FIG. In FIG. 1, the same parts as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, an output switching A signal (7) is input to an audio signal processing section (4) via a resistor (R1), and one end of the resistor (R1) is grounded via a switch (SW1). Connected. Similarly, the output switching B signal (8) is input to the audio signal processing unit (4) via the resistor (R2), and one end of the resistor (R2) is connected to the ground via the switch (SW2). .

The switches (SW1) and (SW2)
Are connected so as to simultaneously apply an after-recording signal via a resistor (R3).

As a result, the output switching control signal generated by the manually operated voice output switch is simultaneously grounded via the resistor (R3) by the post-recording signal generated by the post-recording button switch during the post-recording operation, and the post-recording standby state is established. The monitor output from the audio signal processing unit in the after-recording operation state is automatically switched to the normal sound to be re-recorded (after-recording recording) by the fixed head.

FIG. 2 shows another embodiment of the present invention.

In the figure, a mixed signal (10) generated by a manually operated voice input switch (not shown), together with the voice signal processor (4), is connected to one end of the resistor (R3) and the switch (SW1). It is connected to the connection point of the switch control input of (SW2) via the switch (SW3) so as to be grounded.

The HiFi VTR of this embodiment shows a case in which after-recorded audio is reproduced and monitored, in which mixing and reproduction of a HiFi audio signal recorded by a rotary head and a normal audio signal recorded by a fixed head are performed. The audio signal processing of the monitor, that is, the mixing of the HiFi audio and the normal audio is performed by the audio signal processing unit by a mixed signal generated by a manually operated mixing monitor switch (not shown). Then, the input of the after-recording signal for making the output switching control signals (the output switching A signal and the output switching B signal) of the audio output switch into the normal audio is invalidated by the audio signal processing unit by the mixed signal. A mixed sound of the HiFi sound and the normal sound based on the output switching control signal of the output switch is monitored and output.

[0020]

As described above, according to the present invention, the audio monitor output at the time of post-recording is automatically switched to the normal sound to be post-recorded by the post-recording signal based on the post-recording operation, from the sound signal output from the audio signal processing unit. ,
The trouble of manually changing the audio output switch each time can be eliminated. Moreover, the present invention can be implemented with a simple configuration, and the effect is great.

[Brief description of the drawings]

FIG. 1 is an audio output switching circuit showing an embodiment of the present invention.

FIG. 2 is an audio output switching circuit showing another embodiment of the present invention.

FIG. 3 shows a conventional audio output switching circuit.

FIG. 4 is a truth table of an output switching control signal created by an audio output switch according to a conventional example.

[Explanation of symbols]

 Reference Signs List 1 rotating head 2 fixed head 3 external audio input terminal 4 audio signal processing unit 7 output switching A signal 8 output switching B signal 9 post-recording signal

Claims (1)

(57) [Scope of request for utility model registration] 1. A HiFi VTR capable of reproducing an audio multiplexed signal and an audio signal recorded at a predetermined recording position on a magnetic tape by a rotating head and a fixed head and performing after-recording by the fixed head.
a rotating head for reproducing i-voice, a fixed head for reproducing normal voice, an external voice input terminal for inputting normal voice such as a microphone, and a normal voice input from the input terminal and input from the respective heads An audio signal processing unit that performs signal processing on the reproduced audio and selects the signal-processed audio signal based on the audio output control signal, and monitors and outputs the selected audio signal. A signal switching circuit for a video tape recorder, wherein the same audio signal as a normal audio to be recorded is automatically output to a monitor.