JPH0722362B2 - Dubbing equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a dubbing apparatus for an electronic camera system that records and reproduces a video signal, an audio signal, and a data signal on a magnetic disk, and in particular, an audio signal recorded on a magnetic disk. The present invention relates to a dubbing device that reproduces and records on another magnetic disk.

(Background of the Invention) In recent years, a video signal (1 track for field recording and 2 tracks for frame recording is used by using 50 tracks of one magnetic disk.
An electronic camera system for recording and reproducing a voice signal and a data signal has been proposed.

FIG. 3 is a block diagram showing an audio signal recording / reproducing apparatus in such an electronic camera system.

First, in recording an audio signal, the audio signal input from a microphone or the like is level-compressed in the noise reduction circuit 1 and supplied to the time compression circuit 2. In the time compression circuit 2,
First, the voice signal is AD converted, and the digitized voice signal is once written in the memory. Then, when the digital audio signal is read from the memory, the audio compression signal temporally compressed is obtained by using the clock faster than that at the time of writing and performing DA conversion. This audio compression signal is supplied to the audio data adding circuit 3, and ID pulse (starting and ending) for each 1/4 field (however, the polarity is positive or negative) and audio data indicating correspondence with the video recording track are added. . Specifically, as shown in FIG. 4, the start ID 21, the audio data 22, the audio compressed signal 23, and the end ID 24 are arranged in this order.
A signal that repeats every 1/4 field is generated.

The audio compressed signal to which the ID pulse and audio data are added in this way is FM-modulated after being pre-emphasized by the FM modulation circuit 4, and recorded as an audio RF signal on the magnetic disk by the head 6 through the recording amplifier 5. It

On the other hand, in reproducing the audio signal recorded on the magnetic disk 7, the audio RF signal reproduced from the magnetic disk 7 through the head is amplified by the reproduction amplifier 8 and then FM demodulated by the FM demodulation circuit 9 to apply de-emphasis. The reproduced voice compression signal from the FM demodulation circuit 9 is expanded in the original time even if the time expansion circuit 10 performs a process reverse to that of the time compression circuit 2. The reproduced audio signal, which has been returned to the original state by the time extension, is subjected to the level extension having the opposite characteristic to that at the time of recording in the noise reduction circuit 11, and is output from the speaker 12 or the like.

Now, in the case of performing dubbing for reproducing an audio signal recorded on a magnetic disk and recording it on another magnetic disk on the premise of such an audio signal recording / reproducing apparatus, the reproducing side shown in FIG. If the audio signal output obtained from the noise reduction circuit 11 is connected to the audio signal input of another recording device, the audio signal can be dubbed.

(Problems to be Solved by the Invention) However, in a dubbing apparatus using such a conventional reproducing circuit and recording circuit as they are, an audio RF signal reproduced from a magnetic disk is once converted into an original audio signal. Since the audio signal is converted and recorded again after being converted, the RF signal is double converted, and the RF signal is converted to the original signal and further processed individually into the RF signal. However, there is a problem that the S / N ratio deteriorates due to the above.

(Object of the Invention) The present invention has been made in view of such conventional problems, and enables dubbing of an audio signal with a simple circuit configuration without degrading the S / N ratio or the like. It is an object of the present invention to provide such a dubbing device.

(Summary of the Invention) In order to achieve this object, in a dubbing apparatus of the present invention, a reproducing means for reading and reproducing the information from a recording medium on which modulated information is recorded, and information reproduced by the reproducing means. Information conversion means for demodulating and remodulating the demodulated information and then modulating again, and switching whether to convert the information reproduced by the reproducing means by the information converting means,
A switching means provided in a stage preceding the recording means, and the recording means records the information reproduced by the reproducing means through the information switching means or the information not passing through the information switching means on the recording medium according to the switching means. And

(Embodiment) FIG. 1 is a block diagram showing an embodiment of the present invention.

First, the reproducing side 20 will be described. A magnetic disk 7a on which an audio signal is recorded, a head 6a and a reproducing amplifier 8a are provided.
The audio RF signal recorded on the magnetic disk 7a is reproduced by 6a, amplified by the reproduction amplifier 8a, and then supplied to the output terminal 21 for dubbing.

On the other hand, the recording side 30 is provided with the input terminal 22 for dubbing, and the reproduced sound RF from the reproduction side 20 obtained from the input terminal 22
The signal was connected to one of the changeover terminals a of the changeover switch 24, passed through the recording amplifier 5b with the changeover switch 24 being changed over to the changeover terminal a side, and obtained from the reproducing side 20 to the other magnetic disk 7b by the head 6b. The audio RF signal is recorded as it is.

Also, the recording side 30 is played back from the input terminal 22 for dubbing.
An FM demodulation circuit 9b for inputting an RF signal is provided, and the reproduced RF signal is FM demodulated and subjected to de-emphasis and then supplied to the data rewriting circuit 23. The data rewriting circuit 23 is used for rewriting audio data during dubbing. The voice signal whose voice data has been changed by the data rewriting circuit 23, that is, the voice signal having the arrangement shown in the signal waveform of FIG. 4 including the time-compressed voice compressed signal, is FM-modulated again by the FM modulator circuit 4b. , And is supplied to the other changeover terminal b of the changeover switch 24.

Therefore, the changeover switch 24 selects the sound FM signal including the changed sound data in the data rewriting circuit 23 by changing over to the changeover terminal 24 side when changing the sound data, and the magnetic data is generated by the head 6b through the recording amplifier 5b. It comes to record on the disk 7b. Further, when it is not necessary to change the audio data, the changeover switch 24 is switched to the changeover terminal a side so that the audio RF signal obtained from the reproducing side 20 is directly recorded on the magnetic disk 7b. .

Next, the operation of the embodiment shown in FIG. 1 will be described.
20 is the sound from the magnetic disk 7a reproduced by the head 6a
Only the reproduction amplifier 8a that amplifies the RF signal is required, and the recording side
If the audio data of 30 is not required to be changed, only the recording amplifier 5b is used, and the circuit configuration of the reproducing side 20 and the recording side 30 for dubbing is the same as that of the audio recording circuit shown in FIG. Compared to the case where the audio playback circuit is used as it is, it is greatly simplified, and individual signal processing of converting the playback audio RF signal to the original audio signal and further converting the original audio signal to the audio RF signal again is unnecessary. Therefore, the deterioration of the S / N ratio of the audio signal due to dubbing can be minimized.

Further, when it is necessary to change the audio data at the time of dubbing, by selecting the signal processing system of the FM demodulation circuit 9b, the data rewriting circuit 23 and the FM modulation circuit 4b by the changeover switch 24 provided on the storage side 30, You can easily change the audio data.

Even when changing this audio data, the reproduced audio RF signal
Since the data is rewritten in the demodulated state,
As shown in Fig. 3, the process of signal processing is simplified and the S / N ratio is improved as compared with the case where audio data is rewritten after signal processing of time extension and noise reduction after FM demodulation. Deterioration is suppressed to a minimum.

FIG. 2 is a block diagram showing another embodiment of the present invention. In the embodiment shown in FIG. 1, the circuit configuration is exclusively for the dubbing device on the reproducing side and the recording side, but in this embodiment, as shown in FIG. 3, audio recording is performed in one device. For devices equipped with circuits and audio playback circuits,
The dubbing device of the present invention is realized by utilizing a part of a voice recording and reproducing circuit.

That is, the reproducing side 20 is provided with a magnetic disk 7a, a head 6a, and a reproducing amplifier 8a as in the embodiment of FIG. 1, and reproduces a reproduced RF signal from a dubbing output terminal 21 to a recording side dubbing input terminal 22. We are supplying.

The recording side 30 is provided with the audio recording circuit and the audio reproducing circuit shown in FIG. 3 as they are, and the same parts are denoted by the same numbers as in FIG.

In order to realize the function of the dubbing device of the present invention on the recording side 30, the changeover switch 32 for switching the connection between the output of the reproduction amplifier 8 and the dubbing input terminal 22.
And a changeover switch 36 for supplying the reproduction RF signal to the FM demodulation circuit 9 or the recording amplifier 5 following the changeover switch 32.
Is provided. On the input side of the recording amplifier 5, a changeover switch 34 for changing over the signal from the changeover switch 36 and the signal from the FM modulation circuit 4 is provided.

Further, a changeover switch 38 for supplying the output of the FM demodulation circuit 9 to the voice data addition circuit 3 via the time expansion circuit 10 or the changeover switch 40 is provided in order to enable rewriting of the voice data.

The operation of the embodiment shown in FIG. 2 will be described. The dubbing switch 32 of the recording side 30 is switched to the switching terminal b side during the dubbing which does not require the change of the audio data. Further, the changeover switch 36 is changed over to the changeover terminal a side. Furthermore, the changeover switch
By switching 34 to the switching terminal b side, a signal processing loop for dubbing which directly supplies the reproduced voice RF signal obtained from the reproducing side 20 to the head 6 via the recording amplifier 5 is formed.

On the other hand, when the voice data needs to be changed, the changeover switch 32 is changed over to the changeover terminal b side.
Similarly, 36 is switched to the switching terminal b side. In addition, changeover switch
38 is switched to the side a, and the changeover switch 40 is switched to the side of the switching terminal b. In addition, the changeover switch 34 is set to the changeover terminal a.
By switching to the side, a signal processing loop for changing the audio data supplied from the reproduction side 20 to the head 6 through the FM demodulation circuit 9, the audio data addition circuit 3, the FM modulation circuit 4 and the recording amplifier 5 is provided. The audio data to be dubbed is changed by the audio data adding circuit 3.

In the embodiment shown in FIG. 2 as well, if it is not necessary to change the audio data, the reproduced audio RF signal from the reproducing side 20 is sent to the recording side as it is for recording. This is performed by using the FM demodulation circuit 9 and the audio data adding circuit 3 which are provided in advance on the recording side 30, compared to the case of dubbing using the conventional recording / reproducing circuit shown in FIG. 3 as it is. Since the signal processing becomes simple, it is possible to minimize the deterioration of the S / N ratio,
Also, the circuit configuration of the dubbing device itself can be simplified.

(Effect of the Invention) As described above, according to the present invention, when it is necessary to change audio data during dubbing, for example, the data is rewritten in the state where the reproduced audio RF signal is FM demodulated, and the data is rewritten. If it is done, the information is converted to FM because it is FM-modulated again and recorded on another magnetic disk.
Only two stages of demodulation and FM modulation are required. Compared with multi-stage conversion such as FM demodulation, time extension, rewriting, time compression, and FM modulation when the conventional recording and reproducing circuit is used as it is, the conversion stage of signal processing. Can be reduced to suppress the deterioration of the S / N ratio to the necessary minimum.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a second embodiment of the present invention, and FIG. 3 is a block diagram showing an example of a conventional recording and reproducing circuit. , 4th
The drawing is a signal waveform diagram showing an array of signals obtained from the data adding circuit of FIG. 1: Noise reduction circuit (level compression) 2: Time compression circuit 3: Audio data addition circuit 4,4b: FM modulation circuit 5,5b: Recording amplifier 6,6a, 6b: Head 7,7a, 7b: Magnetic disk 8 , 8a: Playback amplifier 9,9b: FM demodulation circuit 10: Time expansion circuit 11: Noise reduction circuit (level expansion) 12: Speaker 20: Playback side 30: Recording side 21: Dubbing output terminal 22: Dubbing input Terminals 32, 34, 34, 36, 40: Changeover switch

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location H04N 5/781 Z 7734-5C 5/7826 7734-5C H04N 5/91 P

Claims (2)

[Claims] 1. A reproducing means for reading and reproducing the information from a recording medium on which modulated information is recorded, and information for demodulating the information reproduced by the reproducing means, rewriting the demodulated information and then modulating again. Conversion means, recording means for recording the information reproduced by the reproduction means on a recording medium different from the recording medium, and whether or not the information reproduced by the reproduction means is converted by the information conversion means A switching means provided in the preceding stage of the recording means, wherein the recording means is information reproduced by the reproducing means according to the switching means, through the information switching means,
Alternatively, a dubbing device that records information that does not pass through the recording medium. 2. The information converting means according to claim 1, wherein the information reproduced by the reproducing means is FM demodulated, and the demodulated information is rewritten and then FM modulated again. Dubbing equipment.