JPH0488794A - Video recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve the S/N of a color signal component considerably by synthesizing a reproduced luminance signal reproduced by a 1st magnetic head and a reproduced color signal reproduced by a 2nd magnetic head having a wider gap so as to obtain the reproduced video signal. CONSTITUTION:A reproduced luminance signal component VDY reproduced by using a 1st magnetic head 3 suitable for recording and reproduction of a luminance signal component of a video signal and a reproduced luminance signal component VDC1 reproduced by using a 2nd magnetic head 11 having a wider gap than that of the 1st magnetic head 3 are synthesized to obtain a reproduced video signal VDPB1 then the S/N of the chrominance signal component VDC1 is considerably improved without deteriorating the characteristic of the luminance signal component VDY in the reproduced video signal VDPB1.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a video recording and reproducing device, and in particular to a video tape recorder that performs frequency modulation on the luminance signal component of a video signal and performs low frequency conversion on the color signal component for recording and reproducing. can be applied to

B. Summary of the Invention The present invention provides a video recording and reproducing device that reproduces a reproduced luminance signal component reproduced using a first magnetic head suitable for recording and/or reproducing a luminance signal component of a video signal, and By synthesizing the reproduced color signal component reproduced using a second magnetic head having a wider gap width to obtain the reproduced video signal, the S/ of the color signal component in the reproduced video signal is N can be significantly improved.

C. Prior Art Conventionally, in a video tape recorder (VTR) that records and plays back a video signal, the luminance signal component of the video signal is frequency modulated and the color signal component is low frequency converted before being recorded and played back. There is.

That is, as shown in FIG. 3, in this VTR 1, the luminance signal component of the video signal is frequency (FM) modulated and the color signal component is low frequency converted, resulting in a recording signal S□. is amplified by the recording amplification circuit 2 and input to the magnetic head 3 for recording and reproduction.

The magnetic head 3 has a rotary head configuration mounted on a drum (not shown), whereby the magnetic head 3 helically scans the magnetic tape 4 wound obliquely around the drum, and as a result, the magnetic tape 3 is A video signal is recorded on a helical recording track formed on the helical recording track.

In addition, in this way, the video signal recorded on the magnetic tape 3 is read out by the magnetic head 3 and amplified by the reproduction amplification circuit 5, and the resulting reproduction signal S□ bypasses the luminance signal component reproduction system 6. The signal is input to a filter (HPF) 6A and a low-pass filter (LPF) 7A of the color signal reproduction system 7.

The HPF 6A filters the reproduced signal SPI, extracts the luminance signal component of the video signal included in the reproduced signal 5PII, and inputs this to the demodulation port 16B.

As a result, the luminance signal component of the FM-modulated video signal is demodulated in the demodulation circuit 6B, and the reproduced luminance signal component VD obtained as a result is input to the addition circuit 8.

Also, LPF7A filters the reproduced signal S□,
The color signal component of the video signal included in the reproduced signal SFI is extracted, and this is input to the frequency conversion circuit 7B.

As a result, the color signal component of the video signal subjected to low frequency conversion is frequency-converted using the conversion reference signal S, and the resulting reproduced color signal component VD is input to the addition circuit 8.

This adder circuit 8 adds and synthesizes the reproduced luminance signal component VDy and the reproduced color signal component V D c that are input, reproduces the video signal recorded on the magnetic tape 3 in this way, and produces a reproduced video signal VD. It is designed to obtain □.

D Problems to be Solved by the Invention In the VTR 1 having such a configuration, recording and reproducing of shorter wavelengths has become commonplace due to the recent trend toward higher resolution and wider bandwidth.

In particular, as shown in Fig. 4, when trying to improve the resolution of the second-degree signal component sY, when performing FM modulation, the frequency between the zinc level frequency f□NC and the white level frequency f, □ is widened. The frequency band is not limited to just 00-10 (7), but it also extends to the side band frequency band, so that recording and reproduction can be performed in a wide frequency band of 00-10 (7).

In order to record and reproduce signals with such a wide frequency band,
The magnetic head 3 has a narrow gap width, so that the high-frequency transient portion of the FM-modulated luminance signal component Sv can be reliably reproduced, and the inversion phenomenon of the reproduced video signal can be prevented. is being done.

On the other hand, with respect to the luminance signal component S1, the chrominance signal component S is directly recorded by low-pass conversion using frequency 688 (amplitude CAM of k7) modulation, and in practice, the recording wavelength is compared to the luminance signal component Sy. The magnetic tape 4 is deep-recorded for a long time, and is recorded and reproduced in a frequency band of 0 to 1.5 (M7).

However, narrowing the gap width of the magnetic head 3 is effective for reproducing the luminance signal component S having a short wavelength, but when reproducing the low frequency converted color signal component Sc, the magnetic head 3 is There was a problem in that the reproduction efficiency of No. 3 decreased and the S/N of the reproduced color signal component actually deteriorated.

Therefore, in the above-mentioned VTR1, if an attempt is made to improve the characteristics of the luminance signal component reproduction system 6, the characteristics of the chrominance signal component reproduction system 7 will deteriorate, and in the end, both the luminance signal component and the chrominance signal component cannot be reproduced with high accuracy. It was difficult to play.

The present invention has been made in consideration of the above points, and is a video recording and reproducing apparatus that can significantly improve the S/N of the color signal component reproduction system without deteriorating the characteristics of the luminance signal component reproduction system. This is what we are trying to propose.

El! Means for Solving Il In order to solve this problem, in the present invention, the luminance signal component of the video signal is frequency-modulated and recorded on the same recording track, and the color signal component of the video signal is low-frequency converted and directly recorded. A video recording/reproducing apparatus l configured to record a video signal includes a first magnetic head 3 suitable for recording and reproducing a luminance signal component of a video signal, and a first magnetic head 3 disposed close to the first magnetic head 3. A second magnetic head 11 having a wider gap width than the magnetic head 3 is provided.

A reproduced luminance signal component ■DV reproduced using the first magnetic head 3 suitable for recording and reproducing the luminance signal component of the F-action video signal;
Reproduced color signal component V reproduced using the second magnetic head 11 having a wider gap width than the first magnetic head 3
D, , , are synthesized to obtain the reproduced video signal VDPII, the characteristics of the luminance signal component VD in the reproduced video signal VDPII are not deteriorated (the S/N of the color signal component VDCI is significantly reduced). can be improved.

G example An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, in which parts corresponding to those in FIG. 3 are denoted by the same reference numerals, 10 indicates the VTR according to the present invention as a whole, and in this case, a second read-only drive is installed at a position preceding the magnetic head 3 by, for example, 2H. A magnetic head 11 is arranged.

This second magnetic head 11 also has a rotating head configuration mounted on a drum (not shown) like the magnetic head 3,
While the magnetic head 3 is selected to have a gap width suitable for recording and reproducing the luminance signal component S of the video signal, the second magnetic head 11 is selected to have a gap width approximately twice that. has been selected.

By selecting the gap width of the second magnetic head 11 to be approximately twice the gap width of the magnetic head 3, as shown in FIG. 2, it is suitable for recording and reproducing the luminance signal component Sy. In contrast to the frequency characteristic TMG of the magnetic head 3 which obtains the maximum output in the (low) frequency domain, the second magnetic head 11 has a frequency characteristic Tw such that the maximum output is obtained in the low (low) frequency domain.

It is designed to have the following.

In the case of this embodiment, such a frequency characteristic T. G and TNG
Based on this difference, during reproduction, the magnetic head 3 is used to reproduce the luminance signal component Sv, and the second magnetic head 11 is used to reproduce the color signal component St.

This second magnetic helad 11 reads the video signal recorded on the magnetic tape 3, and the resulting second reproduction signal SpH is amplified by the reproduction amplification circuit 12, and the color signal reproduction system 13 The signal is input to the filter filter (LPF) 13A.

This LPF 13A filters the second reproduced signal S1.1, extracts the color signal component of the video signal included in the second reproduced signal 5PII, and frequency-converts this through a delay circuit 13B having a delay time of 2H. It is input to circuit 13C.

As a result, the color signal component of the low frequency converted video signal is frequency-converted using the conversion reference signal Sf, and the resulting second reproduced color signal component Dcl is input to the adder circuit 8.

This adder circuit 8 adds and synthesizes the input reproduced luminance signal component ■Dv and the second reproduced color signal component ■Dc1, and thus reproduces and reproduces the video signal recorded on the magnetic tape 3. A video signal VD, □ is obtained.

In this embodiment, the reproduced signal S sent out from the regenerative amplifier circuit 5 is input to the LPF 14A of the phase matching system 14 in addition to the HPF 6A of the luminance signal component reproduction system 6.

This LPF 14A filters the reproduced signal S0, extracts the color signal component of the video signal included in the reproduced signal SPI, and converts it into the second reproduced signal S□1 sent from the LPF 13A of the color signal reproduction system 13. It is input to the phase comparator circuit 14B together with the color signal component of the included video signal.

This phase comparison circuit 14B compares the phases of the color signal component of the video signal included in the reproduced signal S0 and the color signal component of the video signal included in the second reproduced signal S□1, and corrects the phase difference. The phase difference control signal CD is sent to the delay circuit 13B of the color signal reproduction system 13.

As a result, the delay time of the delay circuit 13B is controlled according to the phase difference control signal CD, and thus the reproduced luminance signal component VD, which is transmitted from the luminance signal component reproduction system 6, is transmitted from the chrominance signal reproduction system 13. The phases of the reproduced color signal components V D c are made to match.

This adder circuit 8 receives the reproduced luminance signal component V D
y and the second reproduced color signal component VDc+ are added and synthesized, and thus the video signal recorded on the magnetic tape 3 is reproduced to obtain the second reproduced video signal DpH1. .

As described above, in the case of this embodiment, the reproduced luminance signal component VD reproduced using the magnetic head 3 and the reproduced luminance signal component VD reproduced using the second magnetic head 11 having a wider gap width than the magnetic head 3. By combining the color signal component VDc and the reproduced video signal VD, □, the S/N of the color signal component VDc, can be reduced without deteriorating the characteristics of the luminance signal component VDv of the reproduced video signal. can be significantly improved.

Incidentally, according to experiments, when the gap width of the magnetic head 3 is selected to be, for example, 0.39 (μl), the second magnetic head 11
If the gap width is selected to be, for example, 0.76 Cμm, the S/N of the AM-modulated color signal component will be approximately 2.5.
(dB).

According to the above configuration, the reproduced luminance signal component VD reproduced using the magnetic head 3 suitable for recording and/or reproducing the luminance signal component S of the video signal, and the gap width wider than that of the magnetic head 3. By combining the reproduced color signal component VD reproduced using the second magnetic helad 11 with the reproduced video signal VD, , to obtain the reproduced video signal VD, . It is possible to realize a VTR 1 that can significantly improve the S/N of color signal components without deteriorating the characteristics.

In the above embodiment, the phases of the color signal component in the reproduced signal input to the luminance signal reproduction system and the color signal component of the color signal reproduction system are compared, and the phases of the reproduced luminance signal component and the reproduced color signal component are determined. Although the case where they are combined is described above, the phase is not limited to this, and the phases of the luminance signal component of the luminance signal reproduction system and the color signal component of the chrominance signal reproduction system may be compared.

Furthermore, in the above-described embodiment, the case where the phase alignment of the reproduced luminance signal component and the reproduced color signal component is always executed is described, but this is not limited to this. If the accuracy is improved, it is not necessary to constantly match the phases of the reproduced luminance signal component and the reproduced color signal component, and the delay amount of the delay circuit may be made variable for adjustment.

Further, in the above-described embodiments, the present invention is applied to a playback system of a video tape recorder, but the present invention is not limited to this. For example, if a magnetic head dedicated to playback of color signals is used for recording, It can also be applied to other recording systems.

H Effects of the Invention As described above, according to the present invention, the reproduced luminance signal component reproduced using the first magnetic head through which the luminance signal component of the video signal was recorded and reproduced is By combining the reproduced color signal component reproduced using the second magnetic head having a wide gap width to obtain the reproduced video signal, the luminance signal component in the reproduced video signal is deteriorated. S of the color signal component in the reproduced video signal.
It is possible to realize a video recording and reproducing device that can significantly improve /N.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a video tape recorder according to the present invention, FIG. 2 is a characteristic curve diagram showing frequency characteristics of a magnetic head, FIG. 3 is a block diagram showing a conventional video tape recorder, and FIG. The figure is a signal waveform diagram showing frequency allocation of a video recording signal. 1.10...VTR12...recording amplifier circuit, 3.11...magnetic head, 6...
- Luminance signal component reproduction system, 7.12... Color signal reproduction system. Agent Keiki Tanabe

Claims (1)

[Scope of Claims] A video recording and reproducing apparatus configured to frequency-modulate and record the luminance signal component of a video signal on the same recording track, and to low-pass convert the color signal component of the video signal and directly record the same. , a first magnetic head suitable for recording and/or reproducing the luminance signal component of the video signal; and a first magnetic head disposed close to the first magnetic head and having a gap width compared to the first magnetic head. a wide second magnetic head, and a reproduced luminance signal component reproduced using the first magnetic head and a reproduced color signal component reproduced using the second magnetic head are synthesized to obtain a reproduced video signal. A video recording and reproducing device characterized by: