JPH0197094A - Method for recording and reproducing video signal - Google Patents

Abstract

PURPOSE:To improve an S/N with respect to a red color and to improve visually the S/N of colors by setting the polarity of color difference signals which mainly include red components at the time of FM modulation in such a way that a carrier frequency in a red part comes to the side of a low frequency in a modulated frequency area and FM recording them at the time of recording and reproducing the component video signal by FM demodulating. CONSTITUTION:The polarity of the R-Y signals to be recorded is inversely converted compared to a conventional example, and are FM recorded and reproduced. Thus, the carrier frequency of the signals which mainly include red components can be reduced from f1 to f2, and f2 is equivalent to the side of the low frequency in the modulated frequency area. Namely, the C/N of the head output of the signals is improved, and the S/N with respect to the red color improves too. With improving the S/N with respect to the red color, a reproduced picture with the satisfactory S/N in visual colors is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to FM of component video signals in a VTR.
It is related to recording and playback.

BACKGROUND OF THE INVENTION The following is a method of recording using component video signals consisting of a luminance signal (Y) and color difference signals (R-Y, B-Y) in the recording and reproducing method of a conventional professional 1/2-inch VTR. There is a way to do it.

First, after emphasizing the luminance signal in the approximately 4 MHz band,
FM modulated and recorded on Y track. Next, about 1.5
The time axes of the two color difference signals in the MHz band are each halved.
After time-division multiplexing (approximately 3M1lz band) to compress the time axis, this signal is FM modulated and recorded on the C track. These conditions are shown in FIG.

Furthermore, FIG. 3 shows the relationship between the signal level and modulation frequency during FM modulation in this method. The horizontal axis is the signal level, and the vertical axis is the modulation frequency, showing the case of the RY signal in the color par signal. As can be seen from this figure, the carrier frequency of the red color is fl, and "I" corresponds to the high frequency side of this modulation frequency range. As described in ``Technology, Devices, and Apparatus'' (Sogo Gijutsu Publishing), recording and playback are performed using FM modulation according to the polarity shown in Figure 3, such as M format and Betacam.

FIG. 4 does not show a general head output level and the relationship between the noise level and carrier frequency at that time. The horizontal axis shows frequency, and the vertical axis shows signal level. The higher the carrier frequency, the lower the head output signal level and the higher the noise level. Therefore, it can be seen that the carrier-to-noise ratio (C/N ratio) of the head output signal deteriorates as the frequency increases, and the S/N ratio also deteriorates at the same time.

In other words, it can be said that in this method, the S/N ratio for red is particularly poor.

Problems to be Solved by the Invention In general, R-Y signals are visually more sensitive and more noticeable than B-Y signals, so when the S/N ratio deteriorates due to dubbing or track misalignment, red Partial noise is easily noticeable. In the conventional video signal recording and reproducing method described above, since the S/N ratio for red is poor, there is a problem in that the S/N ratio for the color visually becomes poor. The present invention aims to provide a new video signal recording and reproducing method that solves the above FWI 8 points.

Means for Solving the Problems The present invention provides that when a component video signal consisting of a luminance signal and two color difference signals is FM modulated and recorded and reproduced, the polarity during FM modulation of the color difference signal mainly containing a red component is set to red. This invention provides a video signal recording and reproducing method characterized in that FM recording is performed by setting the carrier frequency of a portion to be on the low frequency side in a modulation frequency region.

Effect of the Invention With the above-described configuration, the carrier frequency of the signal containing many red components is on the low frequency side of the modulation frequency region, so the S of the red reproduced signal is
/N ratio is better.

Embodiment FIG. 1 shows a relationship between signal level and modulation frequency during FM modulation in an embodiment of the present invention. The horizontal axis is the signal level, the vertical axis is the modulation frequency, and R-Y in the color bar signal.
The case of a signal is shown. As shown in FIG. 1, in this embodiment, the polarity of the R-Y signal to be recorded is reversely converted from that of the conventional example, and then FM recording and reproduction is performed. I can be lowered to 2, and this f2 is on the low frequency side of the modulation frequency region.In other words, from the relationship shown in Figure 4, the C of the head output of this signal
The /N ratio is improved, and the S/N ratio for red is also improved.

As mentioned above, when fishing from a boat, the R-Y signal is visually more sensitive and more conspicuous than the B-Y signal. That is, red noise is more noticeable than blue noise, so if the S/N ratio of a signal mainly containing a red component is improved, the color SIN ratio will visually improve. In this embodiment, the S/N ratio for red is improved by converting the polarity of the R-Y signal opposite to that of the conventional example and changing the carrier frequency of the signal containing mainly red components to a low frequency region. In this way, a reproduced image with a visually good color S/N ratio can be obtained.

As described in detail, according to the present invention, it is possible to visually improve the color S/N ratio by improving the S/N ratio for red, which is highly sensitive and conspicuous, and is useful for its practical use. The effect is significant.

[Brief explanation of the drawing]

FIG. 1 shows the R-Y signal in an embodiment of the present invention as FMf.
Figure 2 is an explanatory diagram of signal processing in the conventional video signal recording and reproducing method.
The figure shows the relationship between the signal level and modulation frequency when FM modulating the R-Y signal in the conventional video signal recording and reproducing method.
FIG. 4 is a diagram showing the relationship between signal frequency, head output signal level, and noise level in a typical head. Name of agent Patent attorney Toshio Nakao (1 person) Figure 1 □ Signal level Figure 2 1 Horizontal scanning period Figure 3 11 Chuf Miya level Figure 4

Claims (1)

[Claims] When recording and reproducing a component video signal consisting of a luminance signal and two color difference signals by FM modulation, the polarity during FM modulation of the color difference signal mainly containing a red component is set so that the carrier frequency of the red part is on the low frequency side in the modulation frequency region. A video signal recording and reproducing method characterized in that FM recording is performed by setting the video signal so that