JPH0520605A - Multiplex magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To record an audio signal without any difficulty even if a video signal is not inputted. CONSTITUTION:The device is constituted so that the audio signal is recorded in the deep layer part of a magnetic tape 11 by a rotary head 14 for audio signal and the video signal is recorded on the surface layer part by a rotary head 7 for video signal having an azimuth angle different from that of the rotary head for audio signal. In the case the recording of video signal is unrequired, the audio signal is recorded in the manner of generating a reference timing by a drum rotation timing generator 4 from a substituted video signal generated by a video signal generator 5. The audio signal only can be recorded since the rotation reference timing of drum is obtained even if the video signal is not inputted, and a deterioration of S/N of the audio signal can be reduced by means of restricting the recording current of the unrequired video signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiple magnetic recording / reproducing apparatus, and more particularly to a video tape recorder for recording audio signals as well as video signals.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a conventional multiple magnetic recording / reproducing apparatus. In the figure, 1 is a video signal input terminal, 2 is a video signal recording processing circuit, 3 is a modulation circuit, 4 is a drum rotation timing generator, 7 is a video signal rotary head, 8 is a demodulation circuit, and 9 is a video signal reproduction process. Reference numeral 10 is a video signal output terminal, 11 is a magnetic tape, 12 is an audio signal input terminal, 13 is an FM signal recording processing circuit, 14 is an audio signal rotary head, 15 is an FM signal reproduction processing circuit, and 16 is an audio signal output. It is a terminal.

Next, the operation will be described. First, an audio signal input to the audio signal input terminal 12 is converted to an FM modulation signal by the FM signal recording processing circuit 13, and then recorded by the audio signal rotary head 14 to a deep layer of the magnetic tape 11 to produce an audio signal. Form a track.

On the other hand, the video signal input to the video signal input terminal 1 is separated into a luminance signal and a chromaticity signal by the video signal recording processing circuit 2, and the luminance signal is FM-modulated by the modulation circuit 3.
The chromaticity signal is low-frequency converted and recorded by the video signal rotary head 7 on the surface layer of the magnetic tape 11 so as to be superimposed on the audio signal track at different azimuth angles.

At this time, since the rotary head for audio signals and the rotary head for video signals are mounted on the same drum, they rotate at the same rotational speed, and the rotation cycle is detected by the drum rotation timing generator 4 from the video signal. It is one TV frame cycle.

At the time of reproduction, the audio signal reproduced by the audio signal rotary head 14 is FM demodulated by the FM signal reproduction processing circuit 15 and output from the audio signal output terminal 16.

The video signal reproduced by the video signal rotary head 7 is FM-demodulated by the demodulation circuit 8 to obtain the luminance signal.
The chromaticity signals are converted into the original frequency band, then combined in the video signal reproduction processing circuit 9, and output from the video signal output terminal 10.

The drum rotation period during reproduction is one TV frame period detected by the drum rotation timing generator 4 from the reproduced video signal.

[0009]

Since the conventional multiplex magnetic recording / reproducing apparatus is constructed as described above, even if the audio signal is desired to be recorded but the video signal is not particularly required to be recorded, the video signal is inputted. If this is not done, the reference timing of the drum rotation cannot be obtained, so the audio signal could not be recorded either. Further, since an unnecessary signal is recorded on the surface layer of the audio signal on the magnetic tape, there is a problem that the S / N is deteriorated.

The present invention has been made to solve the above problems, and when it is necessary to record only the audio signal, the audio signal can be transmitted without any problem even if the video signal is not input. It is an object to obtain a multiplex magnetic recording / reproducing apparatus capable of recording.

[0011]

A multiplex magnetic recording / reproducing apparatus according to the present invention records an audio signal in a deep portion of a magnetic layer of a magnetic tape by a rotary head for an audio signal, and an audio signal track formed by the head. In the magnetic layer surface layer part, the video signal rotary head having a different azimuth angle from that of the audio signal rotary head is used to form a video signal track to record the video signal. In the case where there is no such a case, the timing for substituting the video signal is generated, and the voice signal is recorded by the rotary head for the voice signal at the above timing. When it is not necessary to record the video signal, the video signal having no chromaticity component is recorded. Further, when it is not necessary to record the video signal, the video signal recording current is limited.

[0012]

According to the present invention, when it is necessary to record only the audio signal, the rotation reference timing of the drum to which the rotary head is attached can be obtained even if the video signal is not input. Further, it is possible to limit the recording of unnecessary signals.

[0013]

【Example】

Example 1. FIG. 1 is a block diagram showing a multiplex magnetic recording / reproducing apparatus according to an embodiment of the present invention. In the figure, the same or corresponding parts as those in the conventional example of FIG. To do. Reference numeral 5 is a video signal generator.

Next, the operation will be described. When a normal video signal and an audio signal are simultaneously recorded, it is the same as the conventional example, and when it is necessary to record only the audio signal, the signal processing at the time of reproduction and the recording signal processing of the audio signal are conventionally performed. Since it is the same as the example, duplicate description is omitted.

When it becomes necessary to record only the audio signal,
If a video signal is not input to the video signal input terminal 1, a constant video signal generated by the video signal generator 5 is input, and through the same signal processing process as the conventional one, the rotary head 7 for the video signal is used to magnetic tape. On the surface layer 11 of the recording medium, different audio signals are recorded at different azimuth angles.

At this time, since both the audio signal rotary head and the video signal rotary head are mounted on the same drum, they rotate at the same rotation speed, and the rotation cycle thereof is based on the video signal generated by the video signal generator 5. Drum rotation timing generator 4
The period is one TV frame detected in.

Example 2. FIG. 2 is a block diagram showing a multiplex magnetic recording / reproducing apparatus according to another embodiment of the present invention.
The same or corresponding parts as those of the conventional example of FIG. Reference numeral 6 is a video signal recording current controller.

Next, the operation will be described. When a normal video signal and an audio signal are simultaneously recorded, it is the same as the conventional example, and when it is necessary to record only the audio signal, the signal processing at the time of reproduction and the recording signal processing of the audio signal are conventionally performed. Since it is the same as the example, duplicate description is omitted.

When it becomes necessary to record only the audio signal,
When the video signal is not input to the video signal input terminal 1, a constant video signal generated by the video signal generator 5 is input as in the embodiment of FIG. Generates and outputs cycle timing.
Further, the video signal recording current control unit 6 limits the video signal recording current.

At this time, since both the audio signal rotary head and the video signal rotary head are mounted on the same drum, they rotate at the same rotation speed and the rotation cycle thereof is 1 TV frame generated by the drum rotation timing generator 4. It is a cycle.

Example 3. 3 and 4 are block diagrams showing a multiplex magnetic recording / reproducing apparatus according to still another embodiment of the present invention. In the multiplex magnetic recording / reproducing apparatus capable of multiplexing and recording an FM audio signal and a PCM audio signal as an audio signal. This is an example of application. The same as the embodiment of the present invention shown in FIGS. 1 and 2,
Alternatively, the corresponding parts are denoted by the same reference numerals to avoid redundant description. Reference numeral 17 is an audio signal input terminal, 18 is a PCM signal recording processing circuit, 19 is a multiplexing circuit for FM audio signals and PCM audio signals, 20 is a separation circuit for FM audio signals and PCM audio signals,
Reference numeral 21 is a PCM signal reproduction processing circuit, and 22 is an audio signal output terminal.

Next, the operation will be described. Other than the audio signal recording / reproducing signal processing, the video signal recording / reproducing processing and the rotation cycle control of the drum equipped with the rotary head may or may not be necessary for the video signal recording, as compared with the embodiment of FIGS. 1 and 2. Since they are the same, duplicate description will be omitted.

The audio signal input to the audio signal input terminal 12 is converted to an FM modulation signal by the FM signal recording processing circuit 13, and the audio signal input to the audio signal input terminal 17 is P
The CM signal recording processing circuit 18 converts the signal into a PCM modulated signal, and the multiplexing circuit 19 frequency-multiplexes it to record it to the deep portion of the magnetic tape 11 by the audio signal rotary head 14 to form an audio signal track.

During reproduction, the rotary head 14 for audio signals is used.
The audio signal reproduced by is separated into the FM audio signal and the PCM audio signal by the separation circuit 20, and the FM audio signal is FM demodulated by the FM signal reproduction processing circuit 15 and the audio signal output terminal 1
6, the PCM audio signal is a PCM signal reproduction processing circuit 21.
Are demodulated by and output from the audio signal output terminal 22.

Example 4. In the above embodiment, when it is necessary to record only the audio signal, the video signal generator 5 generates a constant video signal instead of the input video signal. What kind of signal is this signal? Good, but
It is desirable that the signal has little influence on the audio signal, and it is better that there is no chromaticity signal component.

Example 5. When the recording current of the video signal is limited, a constant video signal may be generated and output during reproduction.

Example 6. Furthermore, the modulation method and multiplexing method of the video signal and the audio signal are not particularly limited, and the function selection method when recording only the audio signal may be different depending on whether or not the video signal is input to the video signal input terminal. It may be controlled by means.

[0028]

According to the present invention, since the rotation reference timing of the drum to which the rotary head is attached can be obtained even when the video signal is not input, only the audio signal can be recorded. Further, since the unnecessary recording current of the video signal can be limited, the S / N deterioration of the audio signal can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a multiplex magnetic recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a multiplex magnetic recording / reproducing apparatus which is another embodiment of the present invention.

FIG. 3 is a block diagram showing a multiplex magnetic recording / reproducing apparatus which is still another embodiment of the present invention.

FIG. 4 is a block diagram showing a multiplex magnetic recording / reproducing apparatus which is still another embodiment of the present invention.

FIG. 5 is a block diagram showing a conventional multiple magnetic recording / reproducing apparatus.

[Explanation of symbols]

1 Video signal input terminal 4 Drum rotation timing generator 5 Video signal generator 6 Video signal recording current controller 7 Video signal rotary head 11 magnetic tape

Claims (3)

[Claims] 1. An audio signal is recorded by a rotary head for an audio signal in a deep portion of a magnetic layer of a magnetic tape, and a surface portion of the magnetic layer above the audio signal track formed by the recording of the audio signal.
The audio signal rotary head is configured to record a video signal by forming a video signal track by a video signal rotary head whose azimuth angle is different. When the video signal is not required to be recorded, the video signal is recorded to the video signal. A multiplex magnetic recording / reproducing apparatus characterized in that an alternate timing is generated and an audio signal is recorded by the audio signal rotary head at the above timing. 2. When it is not necessary to record a video signal,
2. The multiplex magnetic recording / reproducing apparatus according to claim 1, wherein a video signal having no chromaticity component is recorded. 3. When it is not necessary to record a video signal,
The multiplex magnetic recording / reproducing apparatus according to claim 1, wherein the video signal recording current is limited.