JPS6180669A - Reproducing device - Google Patents

Abstract

PURPOSE:To eliminate the occurrence of a group delay having a frequency characteristic and to avoid the repeatability of PCM data from being deteriorated by bypassing a reproduction signal instead of passing through a high frequency emphasis circuit so as to obtain a reproduction output when the waveform reproduction of the reproduction signal is especially regarded as important. CONSTITUTION:The output of a high frequency emphasis circuit 27 is taken out through a Y-shaped/comb/shaped filter and a processing circuit 28 for including a drop-out compensation circuit to an output terminal 20 P, and supplied to, for instance, a monitor receiver, thereby projecting a reproduction picture. Next, when a PCM processor 10 is connected to a VTR 20, a PCM switch 3 provided at the VTR 20 is turned on. Then switches 1 and 2 are switched to a side B, and in a recording system PCM audio data in the mode of black/ white video signal from the PCM processor 10 is supplied to a pre-emphasis circuit 22 without passing through a Y-shaped/comb-shaped filter 21. On the other hand, the high frequency emphasis circuit 27 and processing circuit 28 are bypassed, and the output of a deemphasis circuit 26 can be obtained at the output terminal 20 P through the switch 2.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a video playback device, particularly for a PC.
The present invention relates to a technique when emphasis is placed on waveform reproduction of a reproduced signal rather than image sharpness, such as when an M audio processor is connected or when editing work is performed.

[Conventional technology]

1el of ゛ζPCM audio processor code for VTR
R, and this PCM processor converts the input analog signal into a PC.
In addition to converting the PCM audio signal into a video signal, the PCM audio signal is recorded and played back on a VTR, and the captured signal is converted back to the original analog audio signal using a PCM processor, so that high quality audio signals can be recorded and played back. It's a monkey. There is a way to use a VTR to do this.

When using such a VTR, when connecting the PCM processor, the switch is turned off and the Y-shaped comb filter for luminance signal separation and the compensating circuit for the trombus 7 are bypassed. There is. This is because the human signal is a PCM audio signal that has the form of a white M4-center image signal but has no horizontal or vertical correlation.

[Problem that the invention seeks to solve]

In this way, when recording and reproducing PCM audio data on a VTR, waveform reproduction of PCM data is particularly important in the reproduction system. This is to ensure that the PCM data is correctly reproduced in the PCM processor.

In general, a VTR reconstruction system is equipped with an area emphasis circuit, and this is equipped with a soyapness volume that emphasizes the contours of the reproduced image, increasing the volume to 11+!
By adjusting the edges, the blurred reproduced image can be made to have distinct outlines that suit the viewer's taste.

However, in a high-frequency emphasis circuit having this sharpness volume, the recurrent signal is subject to group delay. The larger the emphasis P is, the larger the delay amount is, and the group delay amount varies by 1, 7 depending on the frequency of the re-going signal. Therefore, when the reproduced signal through this high-frequency emphasis circuit is supplied to a PCM processor, the error rate increases because the amount of delay applied to the clock signal and the amount of delay for data of various frequencies are different. There was a risk that the transcription would become impossible.

Furthermore, when &uffl or dubbing is performed, it is more important to be able to record the original signal waveform as it is than to playback image quality, and therefore, in this case too, emphasis is placed on waveform playback in the playback yarn. In addition, especially if a signal with 114i@ emphasis in the reproduction system is recorded as described above, when it is played back, it will pass through the high-frequency emphasis U path again, and the reproduction 1I11@! The outline of the image is too conspicuous, making it difficult to see! This results in poor quality.

The present invention improves the above-mentioned drawbacks.

[Means for solving problem JS]

In this invention, especially when the waveform reproduction of the reproduced signal is viewed from the front, the reciprocal output is obtained by high-bass filtering the noise without passing through the high-frequency emphasizing circuit.

[Effect]

When the PCM adapter is connected, the repeating signal does not go through the area emphasis circuit, so the group delay does not increase the frequency characteristic 1j to 4). Therefore, the error rate does not become large and the PCM data is not distorted. Sexuality does not deteriorate. Furthermore, when editing or dubbing, the high frequencies of the reproduced signal after editing and dubbing will not be overemphasized.

〔Example〕

FIG. 1 shows an embodiment of the present invention, in which PCM is used for VTR.
This is an example where a processor is connected.

Note that since the output signal from the PCM processor is in the form of a black and white video signal, only the luminance signal processing system is shown for the sake of explanation, and the color signal system is omitted.

In the figure, OQ is the PCM processor number, and (20) is V
It is TR.

When recording and reproducing normal video signals in the VTR (20), switches (1) and (2) are switched to the A side, and the video signal through the input terminal (20R) is in a Y-shaped comb shape. A luminance signal is obtained by being fed to a filter (21), which is then fed to an FM modulation circuit (23) via a high compensation pre-emphasis circuit (22) for FM modulation, and its modulated output. The signal is the rotating head (24
R) is recorded on the tape as a diagonal track.

The video signal recorded in this way is transferred to a rotating head (24P).
The head output is demodulated by the FM demodulation circuit (25), and the demodulated signal is supplied to the de-emphasis circuit (26) to restore the raised high frequency range to its original state. It will be done.

The output of this de-emphasis circuit (26) is supplied to a high-frequency emphasizing circuit (27), and the rising edges of the IK waveform corresponding to the edge portions of the image are emphasized. The amount of strength is the sharpness volume (27V)
Adjusted by And this time of emphasis on the area v & (21
The output of 1 is a Y-shaped comb filter.

It is taken out to the output terminal (20P) through a processing circuit (28) including a dropout compensation circuit, and is supplied to, for example, a monitor receiver to display a reproduced image. When connecting the processor aω, a PCM switch (3) provided in the VTR (20) is turned on. Then, switches 11) and (2) are switched to the B side as shown in the figure, and the recording thread is set to P.
PC in the form of black and white video signal from CM processor 001
M audio data is supplied to the pre-emphasis circuit (22) without passing through the Y-comb filter (2I).

On the other hand, in the reproduction system, the high frequency emphasis circuit Ia (27) and the processing circuit (28) are bypassed and the de-emphasis circuit Ia (27) and the processing circuit (28) are bypassed.
The output of the ill path (26) is available at the output terminal (20P) via the switch (2).

Accordingly, when the PCM processor O1 is used, the processing circuit (28) including the high-frequency strong tliltrjl path (27) and the comb-shaped filter etc. is bypassed in the reproduction system of the VTR. The 4G is not affected by group delay. Therefore, since the waveform of the reproduced signal is well reproduced, the error rate of the PCM data is lowered, and the III reproducibility of the data is improved.

FIG. 2 shows another example of the present invention, in which the de-emphasis P in the portrait system is suppressed to obtain the effect of emphasizing high frequencies.

1, that is, in this example, FM return 1/8 (25)
The output of is the first de-emphasis times vJI(29+)
(34k combined. This first de-emphasis same l
The amount of de-emphasis in Homura (29+) is smaller than the amount of pre-emphasis during recording, and by leaving a certain amount of the raised high range rather than completely returning it, the i-range strong flJ is be made effective. The amount of de-emphasis is determined by the adjustment volume (29
+V).

When reproducing the video signal, the reproduced signal is obtained through the emphasis circuit (29x), the processing circuit (28), and the A side of the switch (2) to the output terminal (20P). .

Then, when the PCM processor 0ω is connected and the PCM sonar (3) is turned on, the switches (1) and (2) are turned on.
) is connected to the B side, but with the restraining thread, at this time FMfU
The output of a1 times v8 (25) passes through the second emphasis circuit (292), and is supplied to the output E (20F) through iJO on the B side of the switch (2). This second de-emphasis circuit (29?), like the de-emphasis circuit (26) in the example of FIG. 1, has a de-emphasis amount that restores the I1II region lifted by pre-emphasis. Did you?

When the PCM processor 001 is used, it is exactly the same as the example in FIG.

FIG. 3 shows still another example of this invention, during normal playback and P
The use of the CM processor call is exactly the same as the example shown in FIG. 2, but in this example, the editing mode is also taken into consideration.

That is, (4) is &l! When the collection switch (4) is turned on, the recording thread switch (1) remains on the A side, but the reproducing thread switch (2) is switched to the B side. Therefore, it is not possible to record a reproduced signal with high-frequency emphasis (when recirculating after editing,
This prevents the reproduced image from becoming glaring at the outline.

〔Effect of the invention〕

In this invention, the F! ll@! When emphasizing the waveform reproduction of the outgoing signal rather than emphasizing the outline and correcting the blur, use the III region +1! Since the re-outgoing signal does not pass through the control circuit,
The intended purpose can be successfully achieved.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an example of the inventive device together with a recording device, Fig. 2 is a small block diagram of another example of the inventive device together with the recording device, and Fig. 3 is still another example of the inventive device. FIG. 2 is a block diagram showing a recording device and a recording device. (31LA', PCA4 switch, (4) is 15
Festival switch, 001 is PCM processor, (2o) is V
In the TR, (27) is a commercial IM circuit, (28) is a processing circuit including a Y-shaped comb filter, and 1, a loss-out compensation circuit.

Claims (1)

[Claims] When the reproduced signal of the video signal is obtained through a circuit that emphasizes the high frequency range, and when emphasis is placed on reproducing the waveform of the reproduced signal, the reproduced signal can be obtained without passing through the circuit that emphasizes the high frequency range. playback device.