JPH051674B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a playback device with excellent dubbing characteristics.

(Prior Art) A still image recording system (SV system) for recording still image video signals on a porcelain disk or the like has been devised in the past.

The magnetic disk, which is the information recording medium of such an SV system, has a frequency spectrum as shown in Figure 1, for example, with a luminance signal on the high frequency side and a color signal on the low frequency side in the form of a color difference line sequential format. Field recording of only one field or frame recording consisting of two fields is performed.

Therefore, in the regenerator, the color signals must be interpolated to convert a color difference sequential signal into a color difference simultaneous signal.

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

As the above-mentioned conversion method, a method in which the signals of each horizontal line are averaged and interpolated is generally used, and this method is very effective in improving the resolution on the monitor side.

However, when dubbing, the above-mentioned interpolation means conversely deteriorates the resolution. This is because in the standardized SV system format, color signal sequential color difference signals (B-Y, R-
This is because the phase of Y) is said to be arbitrary for odd and even fields, and even in the case of field recording, the recorded signal can be either odd or even fields.

This drawback will be explained using FIGS. 2a and 2b.
1 and 4 are O, SH (H is horizontal period) delay circuit,
SW1 to SW4 are switch circuits, 2, 5, and 6 are 1H
These circuits are delay circuits, and these circuits are provided in the output processing circuit of the playback device, which will be described later.

Figure 2a shows the luminance Y signal interpolation circuit SW1, SW
2 is switched for each field. Therefore, in the first field, the input Y signal is delayed by 1H and output. Also, in the next field,
The skew is compensated by 0.5H delay circuit 1, and the following
The input and output signals of 1H delay circuit 2 are averaged,
As a result, an interpolated signal delayed by 1.5H is output.

Figure 2b shows the color c signal interpolation circuit, SW
3 and 0.5H delay circuit 4 are for skew compensation. The 1H delay circuits 5, 6 and SW4 are for synchronizing line-sequential color difference signals.
In other words, the input line sequential signal is R-Y, B-Y every 1H.
exists, so the other color difference signal, which does not exist, is made into a simultaneous signal by averaging (interpolating) the OH signal and the 2H signal. Therefore, the simultaneous color difference signals are as follows: R-Y: 1H, 1/2 (OH+2H), 1H...B-Y: 1/2 (OH+2H), 1H, 1/2 (OH+2H)... In either case, the interpolated signal is always output as the synchronized signal. Therefore, during dubbing, there is a possibility that the luminance signal will be dubbed with the interpolated signal when reproducing information recorded in the field, and the color signal will continue to be dubbed with the interpolated color difference signal.

Therefore, if dubbing is repeated, the vertical resolution will deteriorate in proportion to the number of dubbing. Such a problem also occurs when interpolation is performed in the horizontal direction, resulting in a deterioration of the horizontal resolution.

(Objective) An object of the present invention is to provide a reproducing device that can eliminate the drawbacks of the prior art described above.

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

(Example) The present invention will be explained below based on examples.

FIG. 3 is a block diagram of a first embodiment of an SV system including a playback device of the present invention, in which 8 is an input processing system, 9 is a recording processing system, 10 is a first playback processing system,
11 is a second reproduction processing system, 12 is an output processing system, 1
3 is a synchronization system, 14 is a magnetic device system, V _IN is a video signal input terminal, and V _OUT is a video signal output terminal as interpolation signal output means.

In the input processing system 8, 15 is an input processing circuit which processes the NTSC signal or the signal input from the input terminal.
It processes RGB signals and other signals into waveforms and converts them into color difference signals.

That is, the input processing circuit 15 outputs a luminance signal (Y+S) including a synchronization signal S, color difference signals (RY), and (B
-Y) are output from the line switch.
The LSW switches the signal every horizontal period and outputs line sequentially.

The luminance signal (Y+S) including the synchronization signal and the color difference line sequential signal are FM-modulated by the modulation circuits 16 and 17 via switches 42 and 43, respectively, and then converted into the luminance signal (Y+S).
+S) is mixed with the mixer circuit 20 via the HPF 18 and the color difference line sequential signal via the BPF 19, and is input to the recording amplifier 22. Incidentally, at this time, the (RY) signal and the (B-Y) signal are FM modulated with different carrier frequencies. The signal amplified by the recording amplifier is sent to the switch 23 in recording mode.
The data is recorded on the disk 24 as a recording medium by the head MH via the head MH. The disk 24 is driven by a motor 25, and the rotation of the motor 25 is controlled by a servo control circuit 26 at a predetermined speed. In the recording mode, the switch 27 is connected to the R side, so the synchronization signal generation circuit 30 is genlocked via the vertical synchronization signal separation circuit 28 based on the synchronization signal output from the input processing circuit 15 together with the luminance signal. The servo control circuit 26 is operated by a synchronization signal from the servo control circuit 26. Note that the synchronizing signal generating circuit 30 is supplied with a signal from the oscillator 29.

Further, the synchronization signal generation circuit 30 outputs the switch
Pulse LSP1 is output to constantly change the LSW every 1H.

In the reproduction 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 HPF32, BPF33
A luminance signal input to each of the two and modulated via the HPF 32 is separated, and a color difference signal modulated via the BPF 33 is separated.

After that, the output of HPF32 is equalizer circuit 3
4, the high frequency components are lifted and the deterioration of the high frequency characteristics in the magnetic device system is compensated for.

Next, the output of this equalizer circuit 34 and
The output of the BOF 33 is demodulated in demodulation circuits 35 and 36, respectively, to obtain a luminance signal and a color difference signal.
The outputs of circuits 35 and 36 are respectively output to Y process circuit 3.
7. After being subjected to various waveform processing in the C process circuit 38, it is converted into an NtSC signal or R, G, B signals, etc. in an output processing circuit 39 serving as an interpolation means. Also, in this output processing circuit 39, there is a fourth circuit which will be described later.
It includes a luminance signal interpolation circuit and a color signal interpolation circuit as shown in the figure, and when dubbing is not performed, interpolation is performed to form a frame signal from the field signal for the Y system, and color difference line sequential signal is performed for the C system. Interpolation is performed to form a simultaneous color difference signal. Also, the interpolated NTSC signal or RGB signal from this output processing circuit is sent to the output terminal V _OUT.
Output via . Further, in this reproduction mode, the servo control circuit 26 is driven based on the oscillator 29 in synchronization with a synchronization signal generated by the synchronization signal generation circuit 30.

Further, this synchronization signal generation circuit 30 is connected to the switch 27.
Since the signal is switched to the P side, the genlock is applied so as to synchronize with the vertical synchronizing signal included in the reproduced signal.

In addition, in this playback mode, the (R-Y) signal and (B
-Y) Perform signal discrimination.

That is, since the carrier frequencies of the (RY) signal and the (B-Y) signal are different from each other, they are distinguished by detecting the frequency component at each frequency.

This detection output is, for example, a high level during the H period when the (RY) signal is superimposed, and a DV bell is output during the H period when the (B-Y) signal is superimposed.
Pulse signal as a discrimination signal that inverts every 1H
When the dubbing switch 40 is switched to the dubbing side, the interpolation process in the output processing circuit 39 is stopped, and the non-interpolated luminance signal and color difference line sequential signal are converted to the dubbing signal through the output processing circuit. Output end D _OUT as part of dubbing signal output means
It is output from Note that the circuits 35 to 39, D _OUT , etc. constitute dubbing signal output means.

FIG. 4 is a block diagram of an example of such an output processing circuit, and in the figure, the same reference numerals as in FIGS. 2a and 2b indicate the same elements.

In this embodiment, a pulse V as a discrimination signal inverted for each field is supplied from the synchronization signal generation circuit 30 to the switches SW1, SW3 and the AND gate 41 in synchronization with the vertical synchronization signal as shown in FIG. .

Also, the signal from the dubbing switch circuit 40
It is input to AND gate 41.

In addition, the detection circuit 41 outputs 1H as shown in FIG. 5b.
A pulse LSP2 that is inverted every (horizontal period) is supplied to the switch circuit SW4, and this pulse LSP2 is outputted from the discrimination signal output terminal LSP2OUT in the output terminal _DOUT together with the dubbing signal. Therefore, when the dubbing switch circuit 40 is not on the dubbing side, a high level signal is output from the dubbing switch circuit 40, and the gate 41 is open.

In this case, the switch circuits SW1, SW2, SW3 are switched for each field.

For example, in the first field, the switch circuit SW
1 to SW3 are connected to the A side, and the luminance signal is delayed by 1H and output. Further, in this field, the color difference signal is obtained alternately as an original signal and an interpolated signal every 1H.

Also, in the second field, the switch circuit SW1
~SW3 is connected to the B side, and the luminance signal is delayed by 0.5H and skew compensated, and the original signal and 1H
Vertical interpolation is performed using the delayed signal.

Also, skew compensation is performed on the color difference signals.

When the dubbing switch circuit 40 is connected to the dubbing side, a low level signal is output and the AND gate 41 is closed.

Therefore, the switch SW2 is opened, so that the same field signals for both the first and second fields are output from the dubbing signal output terminal D _OUT .

In addition, color difference line sequential signals are always processed before interpolation processing.
Since the output of the 1H delay circuit 5 is led to the terminal D _OUT , the delayed original signal is output.

In addition, in this embodiment, the pulse LSP2 is output from the output terminal D _OUT
Since the color difference line sequential signal is output more easily, it is possible to easily distinguish between (RY) and (B-Y) of the color difference line sequential signal on the dubbing device side.

Further, this dubbing signal can be input from the dubbing signal input terminal D _IN on the recording device side.

The switches 42 to 44 are switched to the D side during dubbing recording, and the dubbing luminance signal Y _and the dubbing color line sequential signal C _D are input to the circuits 16 and 17, respectively.

Further, the pulse LSP2 switches the carrier frequency in the modulation circuit 17 according to (RY) and (B-Y).

In addition, in this embodiment, a special dubbing signal output terminal is used.
Although D _OUT is provided, it may also be used as the video signal output terminal V _OUT .

In this embodiment, the input terminal V _IN input processing system 8, the recording processing system 9, the dubbing signal input terminal D _IN , and the amplifier 2
2. A recording device is composed of a magnetic device system 14, a synchronization system 13, etc., and includes a magnetic device system 14, a synchronization system 13, an amplifier 31, a first reproduction processing system 10, a second reproduction processing system 11, and an output processing system 12. , video signal output end
A reproduction device is constituted by the V _OUT dubbing signal output terminal D _OUT and the like.

Further, the magnetic device system 14 and the synchronization system 13 are shared by the recording device and the reproducing device, and all of the circuits shown in FIG. 3 are housed in the same housing.
Of course, the recording device and the reproducing device may be separate bodies.

As described above, according to this embodiment, the dubbing signal output means demodulates the reproduced color difference line sequential signal and outputs it as a dubbing signal, and the discrimination signal output means forms and outputs the discrimination signal corresponding to each color difference signal. Therefore, when dubbing demodulated color difference line sequential signals, each line sequential color difference signal can be distinguished and recorded, and the color difference signals can be replaced by dubbing, and the color difference signals after interpolation can be dubbed and recorded. There is nothing to do.

Next, FIG. 6 is a diagram showing a second embodiment of the present invention, and this embodiment is an example of a playback device that can perform high-quality dubbing even when using signals after interpolation for luminance signals, etc. It is.

In other words, since the discrimination signal ID for discriminating between a field that is vertically interpolated and a _field that outputs the original signal as is is output together with the dubbing video signal, vertically interpolated video signals are output from the playback device. It becomes possible to dub and record only the signals that are not recorded.

In FIG. 6, the same reference numerals as in FIGS. 1 to 5 indicate the same elements.

The discrimination signal _ID of FIG. 5c is formed by ANDing the signal V of FIG. 5a and the signal LSP2 of FIG. 5b. This _ID is output from the terminal IDOUT which serves _as a discrimination signal output means within _DOUT .

Further, during dubbing, this discrimination signal I _D is input to the modulation circuit 16 via the switch 44, so that modulation is performed only while the envelope of _ID is at a high level.

Therefore, the vertically interpolated signal is not recorded.

In addition, the _ID signal is connected to V and LSP in order to reduce the number of terminals.
Although we used an AND signal with 2, if the number of terminals can be increased, each may be output from separate terminals.

(Effects) As explained above, according to the present invention, in a playback device that can perform vertical interpolation processing on a reproduced video signal, it is configured to output a discrimination signal corresponding to the interpolation operation, so that no interpolation processing is performed during dubbing. It becomes possible to record video signals.

Therefore, dubbing can be performed with less deterioration in image quality.

[Brief explanation of drawings]

1 is a diagram showing the recording state of signals on a recording medium, FIGS. 2a and 2b are a Y signal correction circuit diagram and a c signal correction circuit diagram, respectively. FIG. 3 is a diagram of a first embodiment of the present invention.
FIG. 4 is a diagram showing an example of the main part configuration of the output processing circuit, FIG. 5 is a waveform diagram of various discrimination signals, and FIG. 6 is a diagram showing a second embodiment of the present invention. 24...Disc as a recording medium, D _OUT dubbing signal output terminal, 35, 36...Double modulation circuit, 3
7, 38...Process circuit, 39...Output processing circuit as interpolation means, 35 to 39 and D _OUT etc. constitute dubbing signal output means, LSP2,
V, I _D ...Discrimination signal, LSP2OUT, I _DOUT ...Output terminal as discrimination signal output means.

Claims (1)

[Claims] 1. Demodulation means for demodulating a modulated video signal read from a recording medium; interpolation means for periodically forming a vertical interpolation signal using the video signal; periodic interpolation by the interpolation means A playback device comprising a discrimination signal output means for outputting a discrimination signal corresponding to an operation.