JPH0720258B2 - Dubbing system - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a dubbing system for reproducing a video signal recorded on a magnetic disk in an electronic camera system and recording it on another disk.

(Background of the Invention) In recent years, an electronic camera system has been proposed which records and reproduces a video signal of one field or one frame obtained from a captured image on one magnetic disk.

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

Referring to FIG. 3, first, the signal processing for recording will be described. In the case of video input, the decoder circuit 1 converts the signal into Y signals (luminance signals), RY signals, BY signals, and RGB signals.
In the case of input, the matrix circuit 4 converts the Y signal, the RY signal, and the BY signal. The Y signal from the decoder circuit 1 or the matrix circuit 4 is FM-modulated by the FM modulation circuit 3 after the high frequency component is emphasized by the emphasis circuit 2.
It is supplied to the adder circuit 10. Here, in the FM modulation of the Y signal, as shown in FIG. 4 (a), the level of the lower end of the synchronization signal is set to 6M.
It is performed by controlling the oscillation frequency that sets the Hz, 100% white level to 7.5 MHz.

On the other hand, R from the decoder circuit 1 or the matrix circuit 4
The -Y signal and the BY signal are applied to the line sequential circuit 5 and are alternately switched every horizontal scanning, and the C signal (color difference signal RY,
A high-frequency component is emphasized by the emphasis circuit 6 as a chrominance signal which is a line-sequential color-difference signal obtained by line-sequencing BY, and is then FM-modulated by the FM modulator 7 and supplied to the adder circuit 10.

Here, the FM modulation of the C signal has a frequency deviation of ± 0.35 MHz when the pedestal level is 1.2 MHz as shown in FIG. 4 (b) for the − signal, and FIG. 4 for the BY signal. As shown in (c), there is a frequency deviation of ± 0.25 MHz with the pedestal level being 1.3 MHz.

Further, date, track number, field / frame identification data, etc. can be recorded as video data by frequency multiplexing as data at the time of recording. In this data recording, data required by the data creating circuit 8 is first subjected to a predetermined procedure. According to the DPSK modulation circuit 9 and the DPSK method (Differential
The D-M signal (data DPSK modulation signal) is modulated by phase shift keying and is supplied to the adding circuit 10.

As shown in FIG. 5, the adder circuit 10 outputs the Y-FM signal 41, C-
The FM signal 42 and the D-M signal 43 are frequency-divided and added.
However, this signal addition is performed by the Y-FM signal 41 and the C-FM signal 42,
Further, since the occupied bands of the C-FM signal 42 and the D-M signal are overlapped with each other, addition is performed after band limitation using a normal filter or the like.

The V-FM signal thus added by frequency division in the adder circuit 10 is amplified by the recording amplifier 11, and is recorded on the magnetic disk 13 by the head 12 after receiving the setting of the specified recording current.

Next, the signal processing of the reproducing circuit will be described. The V-FM signal reproduced from the magnetic disk 13 by the head 12 is reproduced by the reproducing amplifier.
It is amplified in 21 and supplied to the separation circuit 22. The demultiplexing circuit 22 performs a process reverse to that of the adding circuit 10 to separate the frequency-multiplexed reproduced V-FM signal from the Y-FM signal, C-FM signal and D-M signal by band limitation using a filter or the like, Output to each signal processing circuit.

The Y-FM signal is demodulated by the FM demodulation circuit 13 and then attenuated in the high frequency component emphasized by the de-emphasis circuit 24, and is supplied to the encoder circuit 25 or the matrix circuit 29 as a Y signal. The C-FM signal is sequentially demodulated into an RY signal or a BY signal by the FM demodulation circuit 27 and the de-emphasis circuit 27 and supplied to the reverse line sequential circuit 28. Reverse line sequential circuit 28 is R
Since the −Y signal and the BY signal are alternately input for each horizontal scanning, the signal delayed by one horizontal scanning to restore the original signal and the signal as it is are switched and simultaneously the RY signal and the BY signal are input. Encoder circuit 25 or matrix circuit for Y signal
Supply to 29.

The encoder circuit 25 converts the Y signal, the RY signal, and the BY signal into a video signal, and the matrix circuit 29 converts the RG signal.
Convert to B signal.

On the other hand, the D-M signal is demodulated into a video signal by the DPSK demodulation circuit 30 into a video data signal, and is decoded into data such as a track number by the data decoding circuit 31 and displayed on the monitor 32 or the like.

The signal processing circuit of FIG. 3 is also provided with a delay amount correction circuit, a phase compensation circuit, a dropout compensation circuit, and a reference synchronization signal and pulse generation circuit for timing control. Omitted for simplicity.

When performing so-called dubbing in which a video signal recorded on a magnetic disk is recorded on another magnetic disk on the premise of such signal processing for recording and reproduction, as shown in FIG. 6 (a), for example. As described above, the video output or RGB output 52 of the reproduction signal processing circuit 51 on the reproduction side may be connected to the video input or RGB input 53 on the recording side to perform the reproduction / recording process shown in FIG. In this case, the reproduced video data is also transferred to the recording side as it is, and only the necessary data is rewritten and recorded on the recording side.

(Problems to be Solved by the Invention) However, a video signal reproduced in this way or
In a dubbing apparatus that sends RGB signals and further video data signals to the recording side and re-modulates them, the reproduction signal processing circuit 51 and the recording signal processing circuit 54 are required as shown in FIG. 6 (a). Since each circuit has the circuit configuration shown in FIG. 2, the circuit becomes complicated and the frequency characteristics and the S / N ratio are deteriorated.

Therefore, as shown in FIG. 6 (b), the reproduced V-FM
A device for sending a signal as it is to the recording side for dubbing is also considered.

That is, the V-FM output of the reproducing amplifier 55 on the reproducing side is connected to the recording side and recording is performed directly through the recording amplifier 57.

However, when it is desired to rewrite the data, after only the D-M signal is extracted by the data rewriting circuit 56 from the V-FM signals frequency-multiplexed as shown in FIG. A circuit for adding to the original V-FM signal after modulation is additionally required, and the circuit configuration becomes complicated accordingly.

Another problem is the setting of the recording current. The setting of this recording current is first determined as the optimum current value at the recording current value fy = 7.0 MHz of the Y-FM signal 61 as shown in FIG. 7 (a).

Next, the recording current of the C-FM signal 62 occurs in the electromagnetic exchange system when recording and reproducing the Y-FM signal and the C-FM signal as shown in FIG. 7 (b) when fc = 1.25 MHz. The current level of the C-FM signal 62 shown in FIG. 7 (a) is given so that the unnecessary component 64 of the frequency (fy−2fc) = 4.5 MHz caused by the distortion becomes −33 dB or less than the reproduction level of the fy signal. Determine the level difference AdB.

Further, regarding the D-M signal 63, when fd = 13 × fh (= 15.75 KHz × 13), the recording current value is -20 dB lower than the fc signal 62.

However, if the V-FM output of the reproducing amplifier 55 on the reproducing side is recorded as it is, as shown in FIG.
As is clear from the figure, the signal level of the reproduction output does not match the characteristics of the recording current required at the time of recording, and the level of the low frequency component usually becomes relatively high. Therefore, playback V-FM
For each of the Y-FM signal, C-FM signal and D-M signal included in the signal, a correction circuit for setting the relationship of the recording current as shown in FIG. Since the state varies depending on the characteristics of the head, the characteristics of the magnetic disk, and the characteristics of the recording / reproducing amplifier, it is necessary to adjust the correction circuit for each device, which causes a problem that signal processing for correction becomes difficult.

(Object of the Invention) The present invention has been made in view of such problems in the related art, and the frequency characteristics and the S / N ratio are deteriorated by minimizing the reproduction / recording circuit configuration for dubbing. It is an object of the present invention to provide a dubbing system that does not require a correction process for the recording current characteristic while holding down.

(Summary of the Invention) In order to achieve this object, according to the present invention, a magnetic disk reproducing apparatus for reproducing a signal recorded on a magnetic disk and a signal reproduced by the magnetic disk reproducing apparatus are recorded on another magnetic disk. And a magnetic disk recording device that is a
A reproducing means for reproducing as a signal, a separating means for separating a chrominance FM signal and a data DPSK signal obtained by FM-modulating the luminance FM signal and the line-sequential color difference signal included in the reproduced video FM signal, and each modulating signal. A demodulation means for demodulating, and an output means for outputting each demodulated signal,
The magnetic disk recording device includes a modulator that FM-modulates a chrominance signal that is a line-sequential color difference signal that is a line-sequential luminance signal and a color difference signal output from the output device on the reproducing device side, and data that enables rewriting of the data signal. Rewriting means, DPSK modulating means for DPSK modulating the data signal, adding means for adding the FM modulated luminance signal and chrominance signal, and the DPSK modulated data signal, and the signal added by the adding means A recording means for recording on a magnetic disk is provided.

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

First, the structure of the reproducing side 60 will be described. Reference numeral 61 is a magnetic disk on which a V-FM signal is recorded.
The V-FM signal reproduced by 62 and amplified by the reproducing amplifier 63 is given to the separation circuit 64. Since the separation circuit 64 includes the Y-FM signal, the C-FM signal, and the D-M signal having the frequency band shown in FIG. These three signals are separated and output. Each of the Y-FM signal and the C-FM signal from the separation circuit 64 is supplied to the FM demodulation circuits 65 and 66 and demodulated into a Y signal and a C signal (RY signal, BY signal). , De-emphasis to attenuate high frequency components is not performed,
It is supplied to the output terminals 68a and 68b of the reproducing side 60.

On the other hand, the DM signal from the separation circuit 64 is the DPSK demodulation circuit 67.
It is demodulated by and becomes a video data signal, and the playback side is 60 as it is.
Is supplied to the output terminal 68c of.

Next, the configuration of the recording side 70 will be described.

The recording side 70 is provided with input terminals 69a, 69b and 69c for dubbing, and when dubbing, the output terminal of the reproducing side 60.
68a is connected to the input terminal 69a, the output terminal 68b is connected to the input terminal 69b, and the output terminal 68c is connected to the input terminal 69c by signal lines. Playback side 60
The Y and C signals output from the
Are supplied to the FM modulation circuits 71 and 72 in and are subjected to FM modulation as they are. During this FM modulation, emphasis is usually applied to emphasize the high frequency components of the Y and C signals.
Since the Y signal and C signal input from are already subjected to emphasis, it is possible to omit the emphasis performed prior to FM modulation. The Y-FM signal and the C-FM signal FM-modulated by the FM modulation circuits 71 and 72 are supplied to the adding circuit 75.

Also, the video data signal supplied from the playback side 60 is
The data is given to the data rewriting circuit 73 of 70, the data such as the track number is rewritten if necessary, then modulated by the DPSK modulation circuit 74, and supplied to the adding circuit 75 as a DM signal.

Here, the data rewriting by the data rewriting circuit 73 is performed on the reproducing side.
Since the data signal demodulated by 60 is processed, it is realized by simple circuit processing.

As shown in FIG. 5, the adder circuit 75 outputs the Y-FM signal and the C-FM signal.
The signal and the DM signal are added, amplified by the recording amplifier 76, and then recorded on another magnetic disk 61a through the head 62a.

Next, the operation of the embodiment shown in FIG. 1 will be described. First, regarding the circuit configuration for dubbing, the reproducing amplifier 60 is
3, the separation circuit 64, the FM demodulation circuits 65, 66 and the DPSK demodulation circuit 67 are sufficient. The recording side 70 also has FM modulation circuits 71, 72, a data rewriting circuit 73, a DPSK modulation circuit 74, an adding circuit 75 and a recording amplifier 76. Therefore, as compared with the dubbing in which the conventional recording / reproducing signal processing shown in FIG. 3 is used as it is, the circuit configurations on the reproducing side and the recording side used for dubbing can be simplified,
Since the signal processing becomes simple, it is possible to minimize the deterioration of frequency characteristics and S / N ratio.

For setting the recording current when recording on another magnetic disk 61a, the demodulated Y signal, C signal and data signal are supplied from the reproducing side 60 to the recording side 72, and the Y signal and C signal are FM modulated. Since the data signal is multiplied by DPSK modulation and added, the recording current during dubbing is exactly the same as in the case of normal video input or RGB input, and the same signal processing is performed, as shown in FIG. 7 (a). Since the recording current shown in (2) can be set, it is not necessary to correct the recording current.

FIG. 2 is a block diagram showing a second embodiment of the present invention. In the embodiment of FIG. 1, the dubbing device is divided into a reproducing side and a recording side. As shown, in the case where a recording signal processing circuit and a reproduction signal processing circuit are provided in one device, the reproduction side 60 shown in FIG.
The signal processing after the separation circuit 64 in the above can be performed in one device, and when dubbing, V from the reproducing side to the recording side can be performed.
− Only the FM signal needs to be supplied.

Referring to FIG. 2, the reproducing side 60 reproduces the magnetic disk 61 with the magnetic head 62 and supplies the V-FM signal amplified by the reproducing amplifier 63 to the output terminal 79.

On the other hand, on the recording side 70, only the input terminal 80 for dubbing is provided, and the other circuit configuration uses part of the recording signal processing circuit and the reproduction signal processing circuit shown in FIG.

The number of each circuit block is
The same numbers as those in FIG. 3 are used, and changeover switches 81 to 87 are added to newly configure a signal processing system for dubbing.

That is, the V-FM signal supplied from the reproducing side 60 to the input terminal 80 is input to the separation circuit 22 by the changeover switch 81,
Separated into Y-FM signal, C-FM signal and D-M signal at 22,
The signals are supplied to the FM demodulation circuits 23 and 26 and the DPSK demodulation circuit 30. The outputs of these demodulation circuits are selected by the changeover switches 82 to 84 and given to the FM modulation circuits 3 and 7 and the DPSK modulation circuit 9 via the changeover switches 85 to 87 in the recording signal processing circuit, and after addition, the addition circuit 10 With the recording amplifier 11 to add the head 12
To the magnetic disk 13.

On the other hand, rewriting of the data signal obtained from the DPSK demodulation circuit 30 is necessary by switching the changeover switch 87 to the data creating circuit 8 side because the data creating circuit 8 is provided in advance on the recording signal processing circuit side. The data portion can be rewritten, and it is not necessary to newly provide a data rewriting circuit.

Even when the dubbing according to the present invention is performed by using the device provided with the recording signal processing circuit and the reproducing signal processing circuit in one device as described above, it is used for the dubbing as in the embodiment of FIG. Since the circuit system is suppressed to the minimum,
There is little deterioration in frequency characteristics and S / N ratio, and no correction is required to set the recording current to a specified value.

Of course, as shown in FIG. 2, as an application example of the present invention,
In addition to allowing a circuit system for dubbing processing to be formed in an apparatus provided with a recording signal processing circuit in one apparatus by actuating a changeover switch as shown in FIG. 2, a device dedicated to dubbing shown in FIG. The device configuration shown in the embodiment may be adopted as it is.

As described above, according to the present invention, a magnetic disk reproducing apparatus for reproducing a signal recorded on a magnetic disk,
And a magnetic disk recording device for recording the signal reproduced by the magnetic disk reproducing device on another magnetic disk,
The magnetic disk reproducing device reproduces a reproducing means for reproducing a magnetic disk as a video FM signal, a chrominance FM signal and a data DPSK signal obtained by FM-modulating a luminance FM signal and a line-sequential color difference signal included in the reproduced video FM signal, respectively. The magnetic disk recording apparatus includes a separating unit for separating, a demodulating unit for demodulating each modulated signal, and an outputting unit for outputting each demodulated signal. Modulation means for FM-modulating a chrominance signal, which is a line-sequential color difference signal in which the color difference signal is line-sequential,
A data rewriting means for rewriting the data signal,
DPSK modulating means for DPSK modulating the data signal, adding means for adding the FM modulated luminance signal and chrominance signal, and the DPSK modulated data signal, and the signal added by the adding means to another magnetic disk. Since the recording means for recording is provided, the circuit configuration is greatly simplified as compared with the case of dubbing using a normal recording signal processing circuit and a reproduction signal processing circuit, and as a result, the frequency characteristics and S The deterioration of the / N ratio can be suppressed to a minimum.

In addition, since the reproduced V-FM signal is directly recorded, it is not necessary to correct the recording current required for dubbing. Therefore, the circuit configuration is greatly simplified compared to the necessity of the correction circuit of the device for direct dubbing. Then, it is possible to perform proper recording on the magnetic disk by dubbing.

As an effect of the embodiment shown in FIG. 2, when a recording signal processing circuit and a reproduction signal processing circuit are provided in one device, only the V-FM signal is transferred from the reproduction side to the recording side.
On the recording side, it is sufficient to use a part of the reproduction signal processing circuit and a part of the recording signal processing circuit, and to perform circuit processing for dubbing for remodulating and adding after separating and demodulating the V-FM signal. Dubbing can be easily performed by forming a circuit loop for dubbing with a change-over switch or the like without changing the recording signal processing circuit that it has.

[Brief description of drawings]

FIG. 1 is a block diagram showing the first embodiment of the present invention, and FIG.
FIG. 4 is a block diagram showing a second embodiment of the present invention, FIG. 3 is a block diagram showing an example of a recording / reproducing circuit of a conventional electronic camera system, and FIG. 4 shows FM modulation characteristics of Y signals and C signals. FIG. 5 is a frequency characteristic diagram showing signal components included in the V-FM signal, FIG. 6 is a block diagram showing a conventional dubbing device, and FIG. 7 is a recording current and a reproducing current. It is a characteristic view which showed the relationship about frequency. 60: Playback side 61, 61sa: Magnetic disk 62, 62a: Head 63: Playback amplifier 64: Separation circuit 65, 66: FM demodulation circuit 67: DPSK demodulation circuit 68a to 68c: Output terminal 69a to 69c: Input terminal 70: Recording Side 71, 72: FM modulation circuit 73: Data rewriting circuit 74: DSPK modulation circuit 75: Adder circuit 76: Recording amplifier

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04N 5/91 7734-5C H04N 5/781 510 F 7734-5C 510 L 7734-5C 5/91 P

Claims (1)

[Claims] 1. A magnetic disk reproducing apparatus for reproducing a signal recorded on a magnetic disk, and a magnetic disk recording apparatus for recording the signal reproduced by the magnetic disk reproducing apparatus on a magnetic disk different from the magnetic disk. The above-mentioned magnetic disk reproducing device uses a magnetic disk for video FM.
A reproducing means for reproducing as a signal, a separating means for separating a chrominance FM signal and a data DPSK signal obtained by FM-modulating a luminance FM signal and a line-sequential color difference signal included in the reproduced video FM signal, and the respective modulating signals. The magnetic disk recording device includes a line-sequential color-difference signal obtained by line-sequencing the luminance signal and the color-difference signal output from the output device. Modulating means for FM-modulating the chrominance signal that is
A data rewriting means for rewriting the data signal,
DPSK modulating means for DPSK modulating the data signal, the FM
The modulated luminance and chrominance signals and the DP
A dubbing system comprising: an addition means for adding the SK-modulated data signal and a recording means for recording the signal added by the addition means on the another magnetic disk.