JPS6118276A - Reproducing device - Google Patents

Abstract

PURPOSE:To record a dubbing signal with high quality by providing a dubbing signal output means outputting a video signal not via an interpolation means as a dubbing signal so as to prevent deterioration of resolution. CONSTITUTION:A switch 23 is thrown to the position P in the reproducing mode, a signal is led to a preamplifier 31 via a head MH on a disc 24 and an output of the amplifier 31 is inputted to the 1st reproducing processing system 10. After an output of an equalizer circuit 34 and an output of a BPF33 are mixed by a mixer circuit 40, the result is outputted from an output terminal RF.OUT as a dubbing signal output means as the dubbing signal via a limiter 41 eliminating the noise of AM component. The circuit 41 eliminates the noise such as AM noise of a magnetic device system, slide noise, thermal noise of a magnetic head and modulation noise so as to improve the S/N.

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 magnetic disk or the like has been devised in the past.

The magnetic disk, which is the information recording medium of such an S■ system, has a frequency spectrum as shown in FIG. 1, for example, and a luminance signal on the high frequency side.

On the low frequency side, color signals are recorded in the following format in the order of color difference lines: field recording of only one field or frame recording consisting of two fields.

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

In addition, in the case of field recording, it is necessary to convert the data into a frame signal in order to display an increment display on a 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 of a monitor.

However, when dubbing, the above-mentioned interpolation means conversely deteriorates the resolution, because the standardized Sv
In the system format, the phase of the color difference line sequential signal (B'-Y, R-Y) is arbitrary in odd and even fields. This is because the signal used can be either an odd field or an even field.

This drawback will be explained using FIGS. 2(a) and 2(b).

1.4 is a 0.5 (H is horizontal period) delay circuit.

5WI-3W4 is a switch circuit, 2 and 5.6 are lH delay circuits, and these circuits are provided in the output circuit of the playback device, which will be described later.

Figure 2(a) shows a luminance (Y) signal interpolation circuit, with SWI,
SW2 is switched every l field. Therefore, in the first field, the input Y signal is output in IH delayed form. In addition, in the next two yields, the skew is compensated by the 0.5H delay circuit 1, averaged by the input/output signal of the next IH delay circuit 2, and as a result, an interpolated signal delayed by 1.5H is output. Ru.

FIG. 2(b) shows a color (c) signal interpolation circuit, and SW
3 and 0.5 H delay circuits 4 are for skew compensation. The IH delay circuits 5, 6 and SW4 are for synchronizing line-sequential color difference signals.

That is, since the input line sequential signal has R-Y and B-Y for each IH, the other color difference signal that 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 R-Y: IH, +(OH+IH), IH...-
-...B-Y: ±(OH+IH), IH' (OH
+IH)...2 .tau., and one of the color difference signals is always an interpolated signal that is output as a synchronized signal.

Therefore, during dubbing, there is a possibility that the luminance signal will be dubbed with the interpolated signal when reproducing field-recorded information, and the color signal will always be dubbed with the interpolated color difference signal.

This problem, which worsens in proportion to the number of dubbings, also occurs when interpolation is performed in the horizontal direction, resulting in a deterioration of the horizontal resolution.

Furthermore, when information recorded on a magnetic disk is dubbed to another PM disk, the following time axis fluctuation problem occurs.

That is, small screen distortions occur in the horizontal direction of the reproduced screen due to time axis fluctuations caused by time axis fluctuation waves caused by the motor and load fluctuations on the disk and magnetic head. Currently, this is corrected using the AFC characteristics of the display, but if dubbing is repeated, the time fluctuation becomes large and correction becomes impossible.

In addition, in the magnetic conversion system, the S/S of the reproduced modulated signal is affected by AM noise, sliding noise, thermal noise of the magnetic head, modulation noise, etc. due to subtle differences in touch between the magnetic disk and the magnetic head.
N deteriorates.

Another major problem is that particularly in the recording/reproducing system of magnetic disks and magnetic heads, high frequency characteristics deteriorate.

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

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

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

FIG. 3 is a block diagram of the first embodiment of the Sv system including the playback device of the present invention. In the figure, 8 is an input processing system, 9 is a recording processing system, IO is a first playback processing system, and 11 is a first embodiment of the Sv system. 2 is a reproduction processing system, 12 is an output processing system, 13 is a synchronization system, 14 is a magnetic device system, VIN is a video signal input terminal, and 2 is a video signal output terminal as an interpolation signal output means.

In the input processing system 8, 15 is an input processing circuit which performs waveform processing on the NTSC signal or R, G, B signals, etc. input from the input terminal 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) and color difference signals (RY), (B-Y).The two color difference signals are outputted every horizontal period by a line switch LSW. It is switched and output.

The luminance signal (Y+S) including the synchronization signal and the color difference line sequential signal are modulated by modulation circuits 16 and 17, respectively, and then converted into the luminance signal (Y+S).
-+-S) through the HPF 18, and the color difference line sequential signal through the BPF 19, mixed in a mixer circuit 20, and input into the recording amplifier 22 through a switch 21. In the recording mode, the signal amplified by the recording amplifier is sent to the disk 24 as a recording medium by the head MH via the switch 23.
recorded in 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 vertical synchronization signal separation circuit 2.
The servo control circuit 2 is connected to the servo control circuit 2 based on the synchronization signal output from the input processing circuit 15 along with the luminance signal.
6 works.

Also, when recording a dubbing signal, switch 21 is set to R.
If connected to the F1N side, the dubbing input signal will be sent to the recording amplifier 2.
2, the recording current is amplified to the optimum recording current and recorded.

Also, in the playback mode, the switch 23 is switched to the P side, and the signal on the disk 24 is sent to the preamplifier 3 via the head MH.
I am guided by 1.

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

Thereafter, the high frequency component of the output of the HPF 32 is raised by the equalizer circuit 34 to compensate for the deterioration of the high frequency characteristics in the magnetic device system.

Next, the output of this equalizer circuit 34 and the BPF3
The outputs of 3 are demodulated in demodulation circuits 35 and 36, respectively,
A luminance signal and a color difference signal can be obtained. The outputs of the circuits 35 and 36 undergo various waveform processing in a Y process circuit 37 and a C process circuit 38, respectively, and then are converted into NTSC signals or R, G, and B signals in an output processing circuit 39 serving as interpolation means. Also, in this output processing circuit 39, there is a
) and (b), which perform interpolation to form a frame signal from the field signal for the Y system, and perform interpolation from the color difference line sequential signal for the C system. Interpolation is performed to form color difference simultaneous signals.

Further, the interpolated NTSC signal or RGB signal from this output processing circuit is outputted via the output terminal V UT .

Also, in this playback mode, the servo control circuit 26
9 and is driven in synchronization with a synchronization signal generated by a synchronization signal generator 30.

Note that the output of the equalizer circuit 34 and the output of the BPF 33 are mixed by a mixer circuit 40 and then passed through a limiter 41 for removing AM acid component noise as a dubbing signal to the output terminal RF as a dubbing signal output means.
It is output from UT.

Here, the limiter circuit 41 is for removing AM noise of the magnetic device system, sliding noise, thermal noise of the magnetic head, modulation noise, etc., thereby improving the S/N. In this embodiment, input terminal V, input processing IN', science system 8, recording processing system 9, dubbing signal input terminal RF
Amplifier 22, magnetic device system 14. A recording device is constituted by a synchronous IN system 13, etc., and a magnetic device system 14,
Synchronization system 13, amplifier 31, first reproduction processing system lO1 second
A reproduction apparatus is constituted by a reproduction processing system 11, an output processing system 12, a video signal output terminal V, a dubbing signal output terminal RF, 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 the circuits shown in FIG. 3 are housed in the same housing.

As described above, according to this embodiment, since the dubbing signal output means for outputting the reproduced signal as a dubbing signal before interpolation is provided, it is possible to dub the signal without deteriorating the resolution etc. .

In addition, an input terminal RFIN and a switch 21 are also provided on the recording device side so that the modulated signal can be recorded directly on the magnetic bed.
, it is possible to record the modulated signal sent from the playback device without further modulating it.

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

In this embodiment, the limiter circuit 41 is connected to the input (RF) of the recording device.
r N) side.

In the first and second embodiments, the RFoUT may be installed after the preamplifier 31, or the limiter circuit may be omitted as long as the influence of AM noise can be ignored.

Next, the third embodiment shown in FIG.
The doubled signal is demodulated once, and then, after correcting signal deterioration in the magnetic device system, it is modulated again and output as an RF dubbing signal. The output RF dubbing signal is dubbed (recorded) onto a magnetic disk via an RF input terminal of another recording device and a preamplifier.

In the drawings, the same reference numerals as in FIGS. 1 to 4 indicate the same elements. 42 to 44.50 are switches connected to the P side in recording mode and R1 playback mode.

45 is a horizontal synchronizing signal separation circuit, 46 is a phase comparison circuit, 4
7 is a VCO (voltage controlled oscillation) circuit, 48 is a PLL (phase lock control) circuit, and 49 is a time axis correction circuit.

Corrections for signal deterioration include AM noise removal, modulation frequency characteristic correction, time axis fluctuation correction, and the like. The correction of the time axis fluctuations described here is performed using an analog delay line such as a CCD. That is, the demodulated Y+S signal (or color difference line sequential signal) is transferred in the time axis drive correction circuit 49 with a pulse TP modulated so as to eliminate the time axis fluctuation caused in the magnetic device system 1.4. The CCD drive pulse TP is a reference horizontal synchronization signal generated by the synchronization signal generation circuit 30,
A circuit 46 compares and detects the demodulated signal passed through the time axis correction circuit 49 with the horizontal periodic signal separated by the circuit 45.
(time axis fluctuation) is obtained by obtaining an error signal and controlling the vCO circuit 47 so that this error signal becomes O.

In this embodiment, in the playback mode, the demodulated video signal is once compensated for signal degradation by the second playback processing system 11, and then modulated again by the recording processing system 9 including the modulation circuit on the recording device side to generate the dubbing signal. as output terminal RF
It is output from UT.

By performing the signal processing as described above, it is possible to output an RF multiplied signal that is optimal for dubbing and compensates for signal deterioration.

In this embodiment, the signal processing for compensating for signal deterioration is performed using R.
Although this is performed on the F signal output (RFOUT) side, it may be performed on the RF signal input (RFIN) side.

(Effects) As explained above, according to the present invention, deterioration of resolution can be prevented during dubbing, and high quality dubbing signals can be recorded.

[Brief explanation of drawings]

Fig. 1 is a frequency spectrum diagram of a recording signal in a still image recording system, Fig. 3 is a diagram of a first embodiment of the present invention, Fig. 4 is a diagram of a second embodiment of the invention, and Fig. 5 is a diagram of a third embodiment of the invention. It is. 24 ・・・・・・ Disk as a recording medium. MH...Head. 39 ... Output processing circuit v as interpolation means
OUT... Video signal output terminal as interpolation signal output means. RF...O as a dubbing signal output means
UT dubbing signal output terminal. Patent applicant Canon Co., Ltd. Figure 7 R-Y B-Y

Claims (1)

[Claims] A head that reads video signals from a recording medium. Interpolation means for interpolating the video signal read by the head. Interpolation signal output means for outputting the signal via the interpolation means. A playback device comprising dubbing signal output means for outputting a video signal read by the head and not passed through interpolation means as a dubbing signal.