JPH0681293B2 - Playback device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a reproducing apparatus having excellent dubbing characteristics.

[Prior art]

A still image recording system (SV system) for recording a still image video signal on a magnetic disk or the like has been conventionally devised.

A magnetic disk, which is an information recording medium of such an SV system, has a frequency spectrum as shown in FIG.
Luminance signals are recorded on the high frequency side, and color signals are recorded on the low frequency side in a color difference line-sequential manner.

Therefore, in the regenerator, the color signal needs to be interpolated so as to convert the color difference line-sequential signal into the color difference simultaneous signal.

Further, in the case of field recording, it is necessary to convert it into a frame signal for interlaced display on the monitor.

As the above-mentioned conversion method, a method of averaging the signals of each horizontal line and interpolating is generally used, and the resolution is improved on the monitor, which is very effective.

However, when dubbing, the above-mentioned interpolating means conversely deteriorates the resolution. In the standardized SV system format, the phase of the color difference line sequential signals (BY, RY) of the color signal is assumed to be arbitrary in the odd and even fields, and in the case of field recording. This is because it is considered that the signal to be recorded in either the odd field or the even field is also acceptable in.

This drawback will be described with reference to FIGS. 2 (a) and 2 (b).

1,4 is a 0.5 (H is a horizontal period) delay circuit, SW1 to SW4 are switch circuits, and 2,5,6 are 1H delay circuits. These circuits are provided in the output circuit of the reproducing apparatus described later. .

FIG. 2A shows a luminance (Y) signal interpolation circuit, and SW1 and SW2 are switched for each field. Therefore, in the first field, the input Y signal is output with a 1H delay.
In the next field, the skew is compensated by the 0.5H delay circuit 1 and averaged by the input / output signals of the next 1H delay circuit 2, and as a result, an interpolation signal delayed by 1.5H is output.

FIG. 2B shows a color (c) signal interpolating circuit, and SW3
The 0.5H delay circuit 4 is for skew compensation. The 1H delay circuits 5 and 6 and SW4 are for simultaneously synchronizing the line-sequential color difference signals.

That is, since the input line-sequential signal has RY and BY for every 1H, the other color difference signal that does not exist is made a simultaneous signal by averaging (interpolating) the OH signal and the 2H signal.

Therefore, the simultaneous color difference signal is As described above, either one of the color difference signals always outputs the interpolation signal as the synchronization signal. Therefore, during dubbing, the luminance signal may dub the interpolation signal when reproducing the field-recorded information, and the color signal always dubs the interpolated color difference signal.

Therefore, if the dubbing is repeated, the vertical resolution becomes worse in proportion to the number of times of dubbing. Such a problem also occurs when the interpolation in the horizontal direction is performed, which also deteriorates the horizontal resolution.

Furthermore, when the information recorded on a magnetic disk is dubbed onto another magnetic disk, the following problem of time base fluctuation occurs.

That is, a small screen distortion occurs in the horizontal direction of the reproduction screen due to the time axis fluctuation caused by the motor and the time axis fluctuation caused by the load fluctuation of the disk and the magnetic head. Currently, it is corrected by the AFC characteristics of the display, but if dubbing is repeated, the time fluctuation becomes large and it becomes impossible to correct.

Further, in the magnetic conversion system, the S / N of the reproduced modulation signal is deteriorated due to AM noise, sliding noise, thermal noise of the magnetic head, modulation noise, etc. due to subtle touch differences between the magnetic disk and the magnetic head.

Another major problem is the deterioration of high frequency characteristics, especially in the recording / reproducing system of magnetic disks / magnetic heads.

(Object) The object of the present invention is to provide a reproducing apparatus capable of solving the above-mentioned drawbacks of the prior art.

Another object of the present invention is to provide a reproducing apparatus with less deterioration of resolution.

(Example) Hereinafter, the present invention will be described based on examples.

FIG. 3 is a block diagram of a first embodiment of an SV system including a reproducing apparatus of the present invention, in which 8 is an input processing system, 9 is a recording processing system, 10 is a first reproduction processing system, and 11 is a first processing system. 2, playback processing system, 12
Is an output processing system, 13 is a synchronous system, 14 is a magnetic device system, VIN is a video signal input terminal, and V _OUT is a video signal output terminal.

In the input processing system 8, reference numeral 15 is an input processing circuit for waveform-processing the NTSC signals or R, G, B signals and the like input from the input terminals and converting them into color difference signals.

That is, the input processing circuit 15 outputs the luminance signal (Y + S) including the synchronization signal (S) and the color difference signals (RY) and (BY). Both color difference signals are switched by the line switch LSW for each horizontal period and output.

The luminance signal (Y + S) including the synchronization signal and the color difference line sequential signal are modulated by the modulation circuits 16 and 17, respectively, and then the luminance signal (Y + S).
S) is mixed through the HPF 18, and the color difference line sequential signal is mixed in the mixer circuit 20 through the BPF 19 and input to the recording amplifier 22 through the switch 21. In the recording mode, the signal amplified by the recording amplifier 22 is recorded on the disk 24 as a recording medium by the head MH via the switch 23. The disk 24 is driven by a motor 25, and the servo control circuit 26 controls the rotation of the motor 25 at a predetermined speed.

In the recording mode, since the switch 27 is connected to the vertical synchronizing signal separation circuit 28 side, the servo control circuit 26 operates based on the synchronizing signal output from the input processing circuit 15 together with the luminance signal.

When recording a dubbing signal, switch 21 to RF _IN.
If it is connected to the side, the dubbing input signal is amplified and recorded via the recording amplifier 22 so as to have an optimum recording current.

Further, in the reproducing mode, the switch 23 is switched to the P side, and the signal on the disk 24 is guided to the preamplifier 31 via the head MH.

The output of this amplifier 31 is input to HPF32 and BPF33 respectively, and HPF
The luminance signal modulated via 32 is separated, and the color difference signal modulated via BPF 33 is separated.

After that, the output of the HPF 32 raises the high frequency component by the equalizer circuit 34 to compensate the deterioration of the high frequency characteristic in the magnetic device system.

Next, the output of the equalizer circuit 34 and the output of the BPF 33 are demodulated in the demodulation circuits 35 and 36, respectively, and a luminance signal and a color difference signal are obtained. The outputs of the circuits 35 and 36 undergo various waveform processing in the Y process circuit 37 and the C process circuit 38, respectively, and then are converted into NTSC signals or R, G, B signals in the output processing circuit 39. Further, the output processing circuit 39 includes a luminance signal interpolating circuit and a color signal interpolating circuit as shown in FIGS. 2A and 2B, and for the Y system, forms a frame signal from a field signal. Interpolation is performed. For the C system, interpolation for forming a color difference simultaneous signal is performed from the color difference line sequential signal.

Also, NTSC signals or RGB interpolated from this output processing circuit
Signals and the like are output via the output terminal V _OUT .

In this reproduction mode, the servo control circuit 26 is driven by the oscillator 29 in synchronization with the sync signal generated by the sync signal generator 30.

The output of the equalizer circuit 34 and the output of the BPF 33 are output as a dubbing signal through a limiter 41 for removing the noise of the AM component after being mixed by the mixer circuit 40.
Output from RF _OUT .

Here, this limiter circuit 41 is AM noise of the magnetic device system,
This is to remove sliding noise, thermal noise of the magnetic head, modulation noise, etc., thereby improving S / N. In this embodiment, the input terminal V _IN , the input processing system 8, the recording processing system 9, the dubbing signal input terminal RF _IN , the amplifier 2
2, a magnetic device system 14, a synchronization system 13 and the like constitute a recording device, and the magnetic device system 14, the synchronization system 13, the amplifier 31, the first reproduction processing system 10, the second reproduction processing system 11, and the output processing system 12 , A video signal output terminal V _{OUT, a} dubbing signal output terminal RF _OUT, etc. constitute a reproducing apparatus.

The magnetic device system 14 and the synchronizing system 13 are shared by the recording device and the reproducing device, and the circuits shown in FIG. 3 are all housed in the same housing.

As described above, according to the present embodiment, since the reproduced signal is output as a dubbing signal before being interpolated, the signal can be dubbed without degrading the resolution and the like.

Also, since the input terminal RF _IN and the switch 21 are provided on the recording device side so that the modulated signal can be directly recorded on the magnetic head, the modulated signal sent from the reproducing device side can be recorded without further modulation. You can do it.

FIG. 4 shows a second embodiment of the present invention, in which the same reference numerals as those in FIG. 3 indicate the same elements.

In this embodiment, the limiter circuit 41 is provided on the input (RF _IN ) side of the recording device.

In the first and second embodiments, RF _OUT is the preamplifier 31
The limiter circuit may be omitted if the influence of AM noise can be ignored.

Next, in the third embodiment shown in FIG. 5, the RF signal read by the magnetic device system is once demodulated, after which the signal deterioration in the magnetic device system is corrected and then modulated again and output as an RF dubbing signal. . The output RF dubbing signal of other recording devices
Dubbed (recorded) to a magnetic disk via the RF input terminal and preamplifier.

In the figure, the same reference numerals as in FIGS. 1 to 4 indicate the same elements. Switches 42 to 44, 50 are connected to the R side in the recording mode and the P side in the reproducing mode.

45 is a horizontal sync signal separation circuit, 46 is a phase comparison circuit, 47 is VC
An O (voltage controlled oscillation) circuit, 48 is a PLL (phase lock control) circuit, and 49 is a time axis correction circuit.

The signal deterioration correction includes AM noise removal, modulation frequency characteristic correction, time-axis fluctuation correction, and the like. The correction of the time base fluctuation described here is performed by an analog delay line such as a CCD. That is, the demodulated Y + S signal (or color-difference line-sequential signal) is sent to the magnetic device system 14 in the time axis fluctuation correction circuit 49.
Pulse TP that is modulated so that the time base fluctuation caused by
Transferred in. CCD drive pulse TP is synchronized signal generation circuit 30
In the circuit 46, the reference horizontal synchronizing signal made in (1) and the horizontal period signal separated by the circuit 45 from the demodulated signal via the time axis correction circuit 49 are compared and detected, and the (time axis fluctuation) error signal is obtained,
It is obtained by controlling the VCO circuit 47 so that this error signal becomes zero.

In the present embodiment, the second reproduction processing system is used in the reproduction mode.
The signal signal once demodulated is compensated for signal deterioration by means of 11, and is then re-modulated by the recording processing system 9 including the modulation circuit on the recording device side and output as a dubbing signal from the output terminal RF _OUT .

By performing the signal output as described above, it is possible to output the optimum RF signal for dubbing in which signal deterioration is compensated.

In this embodiment, the signal processing for compensating the above-mentioned signal deterioration is performed by RF
I did it on the signal output (RF _OUT ) side, but the RF signal input (RF _IN )
You may do it on your side.

(Effect) As described above, according to the present invention, it is possible to prevent deterioration of resolution during dubbing, and it is possible to record a high-quality dubbing signal.

[Brief description of drawings]

FIG. 1 is a frequency spectrum diagram of a recording signal in a still image recording system, FIG. 2 (a) is a configuration example diagram of a luminance signal interpolation circuit, and FIG. 2 (b) is a configuration example diagram of a color signal interpolation circuit. FIG. 3 is a first embodiment diagram of the present invention, FIG. 4 is a second embodiment diagram thereof, and FIG. 5 is a third embodiment diagram thereof. 24 …… Disk as recording medium, MH …… head, 39 …… Output processing circuit V _OUT …… Video signal output terminal. RF _OUT: Dubbing signal output terminal.

Claims (1)

[Claims] 1. A reproducing means for reproducing the video signal from the recording medium in which the video signal is recorded every one field, and a reproducing means for reproducing the video signal from the recording medium in every one field. An interpolating means for forming a video signal for one frame by inputting the video signal to be output and performing an interpolating process on the video signal input for every one field; and one field for the interpolating means. A reproducing apparatus having a dubbing signal output means for forming and outputting a dubbing signal using a video signal input every minute.