JPS6162289A - Video signal recording device - Google Patents

Abstract

PURPOSE:To record effectively a wide frequency band video signal by dividing a luminance signal into signals of plural channels for dot-interlacing, recording said signals in each multi-track channel formed sequentially on a recording medium and recording a chrominance information signal on at least one channel of each track. CONSTITUTION:Luminance signals separated by a separator circuit 13 is divided into signals of two channels which dot-interlace by means of a multiplexer 17, and supplied to filters 18a and 18b. The filters 18a and 18b include a comb- shaped filter for removing and LPF and folded noise. The luminance signals of each channel have unnecessary signals removed by the filters 18a and 18b, are FM modulated with the aid of FM modulator circuits 19a and 19b, added to a low frequency conversion macro signal by mixers 16a and 16b, and then recorded in heads 21a and 21b through amplifiers 20a and 20b. The head 21a corresponds to heads 1a and 2a, and the head 21b corresponds to heads 1b and 2b, respectively.

Description

[Detailed description of the invention] Technical fields> The present invention relates to a video signal recording Q device.

<Description of Prior Art> Conventionally, commonly used home video tape recorders (VTRs) transmit luminance signals to FM in a high frequency band.
It is recorded by frequency multiplexing with a chroma signal that has been modulated and frequency-converted to a low frequency band. Generally, VTRs perform this type of recording.

For example, a well-known VH5 format or β format VTR
In this case, the exclusive band of the brightness signal is only about 3MHz, whereas the band of the brightness signal of the television signal is N.
The TSC system is thought to be around 4 or 5 MHz, and in recent years home color television receivers have also increased to 6 MHz.
There are commercially available devices that can reproduce the z band. Therefore, according to the conventional VTR, the resolution has been reduced by the VTR.

Therefore, it is possible to increase the exclusive band of the luminance signal by the VTR, but increasing the relative speed between the head and the medium any further would put a heavy burden on the head and the medium, which is undesirable. Compatibility with VTRs would be completely lost.

On the other hand, the luminance signal band of high-definition television signals, which have been attracting attention in recent years, is thought to be about 20 MHz, and it is impossible to record and reproduce this on a VTR using the current recording method.

<Object of the Invention> The present invention has been made in view of the above-mentioned background, and an object of the present invention is to provide a video signal recording device that can efficiently record a wideband video signal.

(Explanation based on Examples) Hereinafter, as an extremely preferred embodiment of the present invention, the current V
The present invention will be explained by presenting a VTR as an example in consideration of compatibility with the TR.

51 is a diagram showing a head configuration in a VTR as an embodiment of the present invention, and FIG. 2 is a diagram showing a recording formant on a magnetic tape by each head shown in FIG. 1. In FIG. 1, numerals 1 and 2 are multi-heads, each of which sequentially and repeatedly forms multi-tracks 3 and 4 on the magnetic tape 10, respectively. Each multi-tran j3.4 has a first channel 3a, 4a and a second channel 3b, 4b, respectively, with a first channel 3'a.

4a are formed by the first channel heads la, 2a of the multi-head 1.2, respectively, and the second channels 3b, 4b
are formed by second channel heads lb and 2b, respectively. Here, the magnetization direction of channel 3a and the magnetization direction of channel 4a are tilted in opposite directions by the same angle (±θa). Also, the magnetization direction of channel 3b and channel 4
The magnetization direction of a is also tilted by the same angle (±θb) in the opposite direction. However, it is desirable to set θb>θa, and θb=about 30a.

In addition, in Fig. 2, 5a and 5b are the R channel and L channel, respectively.
The audio rack for the audio signal of the channel, 6, is the well-known (,3+
This is a transformer for control signals (CTL).

Next, the recording format of the video signal will be explained. The luminance signal is divided into two dot-interlaced channels. FIG. 3 is a diagram showing how luminance signals are divided into channels, where Y indicates luminance 4g, O indicates sampling points for the first channel, and Δ indicates sampling points for the second channel. A) and (B) are diagrams showing the frequency distribution of the original video signal and the recorded video signal, respectively. In the figures, Y indicates the luminance signal, and C indicates the band of the chroma signal.

Here, the sampling frequency C2f5) by multiplexing, which will be described later, is set to be more than twice the highest frequency (/'C) of the luminance signal, so that all information of the luminance signal is extracted. Also, when considering each channel, it is desirable that the sampling frequency is fSC>fC.This is because, as is well known, in the sampled signal, the lower side wave component of fs overlaps with the original signal and becomes aliasing noise. , sub-Nyquist sampling is performed for each channel.

In this way, the two-channel luminance signal (Y a ,
As shown in FIG. 4, Yb) is frequency-multiplexed with a chroma signal that has been FM modulated in the high frequency range and converted in the low frequency range, and recorded on the first channels 3a, 4a and the second channels 3b, 4b, respectively.

Next, the configuration of the VTR according to this embodiment will be briefly described. FIG. 5 is a diagram showing the configuration of the recording system of this embodiment, and FIG. 6 is a diagram showing the configuration of the reproduction system.

The video signal input from terminal 11 is synchronously mixed, AGC
The signal is supplied to the Y-C separation circuit 13 via a pre-processing circuit 12 including the following. The Y-C separation circuit 13 is usually formed of an LPF (low-pass filter) and a BPF (band-pass filter), but in this case, it also records information on the high frequency components of the luminance signal and performs sub-Nyquist sampling for each channel. It is desirable to separate the luminance and chroma signals using a comb filter.

The chroma signal separated by the separation circuit 13 is supplied to a frequency conversion circuit 14.The frequency conversion circuit 14 performs frequency conversion on the chroma signal according to the well-known PI or PS method, and converts the carrier color signal of the chroma signal into a Converted to low frequency band. Reference numeral 15 denotes a conversion signal forming circuit which forms this conversion signal based on the synchronization signal etc. obtained from the preprocessing circuit 12.

The low frequency converted chroma signal obtained in this way is sent to the mixer 16a.
, 16b.

On the other hand, the luminance signal separated by the 1-segmenting circuit 13 is divided by the multiplexer 17 into two dot-interlaced signals as described above, and filters 18a, .
b. The filters 18a and 18b include an LPF and a comb filter for removing the above-mentioned aliasing noise.The luminance signals of each channel from which unnecessary signals have been removed by the filters L8a and L8b are FM-modulated by FM modulation circuits 19a and 19b. Mixer 16a.

1.6b is added to the low frequency converted chroma signal, and the amplifier 20
It is recorded by heads 21a and 21b via heads 21a and 20b. Note that the head 21a is the head la, 2a, and the head 21b.
correspond to heads lb and 2b, respectively.

Next, the reproduction system will be explained. Head 21a.

The recording signal of each channel reproduced by
0 separation circuits 3La and 31b supplied to FM
It consists of an HPF (bypass filter) for separating modulated luminance signals and a BPF for separating low-frequency converted chroma signals.
The separated low frequency converted chroma signals are respectively sent to the chroma forming circuit 3.
2, is mixed after correcting the alignment error of both channels, and a low frequency converted chroma signal of one channel is obtained.It is returned to the original band by the zero-order frequency converter 33 and is included in the conversion signal forming circuit. Time base correction is performed by the well-known A20 circuit. Also, the aforementioned PI.

The chroma signal returned to the zero band, which also undergoes processing corresponding to the PS system, is supplied to the i1 combination 36 via the BPF 35.
1',,i Meanwhile, each channel's playback FM change ai11
The frequency signal is demodulated by the FM demodulation circuits 37a' and 37b, and then resampled and aligned by the demultiplexer 38, and returned to the original signal containing the Takaoka information. Of course alignment error, time! Correction of the I+ error is to be performed. From the signal obtained from the demultiplexer 38,
The reproduction moderation signal is extracted by the LPF 39 and sent to the post-processing circuit 4.
After processing such as noise reduction is performed in the mixer 36
The reproduced color television signal is output from the terminal 41.

According to the V T'H configured as described above, the recording band of the luminance signal can be substantially doubled, and the wide band quality a
I was able to get a VTR.

In addition, when considering compatibility with current VTRs, the width of multi-track 3.4 should match the track width of current VTRs, and the azimuth angle (±θ&) of the first channel should be adjusted to match the width of multi-track 3.4.
Compatibility is also satisfied if the azimuth angle of R is made to match.

In the above embodiment, the number of multi-track channels is set to 2, but the number of channels may be set to 3 or more. For example, the band of a high-definition television signal is 20 MHz.
Therefore, approximately 6 channels would be necessary.

Further, in the above embodiment, the chroma signal is recorded in all channels, but at least the first channel 3a,
4a, compatibility with current VTRs will be achieved. Also, for chroma signals, dot interlace,
The data may be recorded by dividing it into #i channels by band division or the like.

Furthermore, various embodiments can be considered regarding the azimuth angle. Also, audio signals are recorded on longitudinal tracks 5a and 5b of the tape, but FM change 2I! is recorded on each channel or any channel. It is also possible to record using lf-.

Explanation of Effects> As described above, according to the present invention, a video signal recording device is provided which can widen the recording band of luminance signals and efficiently record wideband video signals.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a head configuration in a VTR as an embodiment of the present invention, FIG. 2 is a diagram showing a recording format on a magnetic tape by each head shown in FIG. 1, and FIG. 3 is a diagram showing a luminance signal. 4(A) and CB) are diagrams showing the frequency distribution of the original video signal and the recorded video signal, respectively. FIG. 5 is a diagram showing the recording system of a VTR as an embodiment of the present invention. FIG. 6 is a diagram showing the configuration of a reproduction system of a VTR as an embodiment of the present invention. 1.2 is a multi-head 3. 4 is a multi-track 3a, 4a is a first channel 17, and a multiplexer 38 is a demultiplexer.

Claims (2)

[Claims] (1) A large number of multi-tracks consisting of a plurality of channels with different magnetization directions are sequentially formed on a recording medium using a multi-head, and a luminance signal is divided into dot-interlaced multi-channel signals for each channel of the track. A video signal recording device for recording a color information signal in at least one channel of each track. (2) A color information signal is recorded in the first channel of each multi-track, and the magnetization direction of the first channel in adjacent multi-tracks is inclined in the opposite direction. A video signal recording device according to scope (1).