JPS5842389A - Recorder - Google Patents

Abstract

PURPOSE:To prevent skew distortion, by arranging a magnetic head for low band frequency signal recording at a position preceding to a magnetic head for high band frequency signal recording. CONSTITUTION:A composite color video signal SI applied to a terminal 1 is given to a low pass filter 2 and a high pass filter 3, and a low band frequency signal SL including signals representing luminance component is picked up from the low pass filter 2 and a high band frequency signal SH including chrominance signal component is picked up from the high pass filter 3. The signal SL is angular-modulated at a modulator 4 and recorded on a tape 6 with a rotary recording head HRL after amplification. After the signal SH is converted into a low band frequency at a frequency converter 7, then the signal is angular- modulated at a modulator 8 and recorded on a separate recording track from the track for the low band frequency signal with a recording head HRH after amplification. At reproduction, the time difference between the signals SL and SH can be adjusted at time axis adjusting circuits 18 and 19.

Description

Detailed Description of the Invention When a color video signal such as an NT8C1 signal is recorded on a VTRK, the characteristics of the signal distribution of the NT8C signal are utilized to record a color video signal such as the NT8C1 signal. Distributed on the regional side, annual 1. Taking advantage of the fact that signal C is distributed on the high frequency side centered on the 3.511 MHm nag carrier, the 5. The luminance signal Y is FM-modulated, one color value C is low-frequency converted, and then this luminance signal YK is superimposed and recorded (Y/C separation sickle recording by color heterodyne method is widely used).

And ζro, Jin's Y/C separation recording method is first! 1K and luminance signal Y11 signal C both have the drawback that they cannot record up to 1 in a wide band.

That is, the luminance signal Y passes through a low-pass filter and is rejected, but considering sufficient separation from the color signal C, the band of the luminance signal Y to be extracted is approximately 3.0 MHg at most. Also, if one attempts to perform wideband 11 low-frequency conversion on one color value C, the low-frequency conversion frequency must be increased, but when ζ is applied, the luminance signal YK! Since the M carrier frequency also increases, triangular noise increases accordingly and the 8/N of the luminance signal Y deteriorates.For these reasons, the color signal C is also limited in its ability to widen the band.

Thirdly, in this recording method using Y/C separation, the third! II
As shown in K, since the low frequency conversion color signal CC, part KFM, and part of the luminance signal Y-FM overlap, Y2O interference, that is, a distortion scalar occurs.

Third, image quality deterioration occurs due to changes in brightness level.

That is, since the FM carrier frequency is used as the AC bias frequency of the low frequency conversion color signal Cc, when the luminance level is magnetized and the FM carrier frequency changes, this AC bias frequency changes. However, in AC bias recording, as shown in Figure 3, the magnetization level and therefore the reproduction output level depend on the bias frequency, so when the luminance level changes, the signal level of the low-frequency converted color signal Cc changes, and the differential gain ( DG) becomes large and the image quality deteriorates.

These drawbacks can be solved by adopting the recording method shown in FIG. 4, for example. Subsequently, the recording method for printing will be explained with reference to FIG. 4 and subsequent figures. The example shown in FIG. 4 is a case where a composite color video signal of the NTaC system is used as the input video signal to be recorded, and aQ is the VTR notation II.
device, ■ indicates the playback device.

The composite color video signal 81 (its frequency characteristics are shown in FIG. 5A) supplied to the terminal (1) is supplied to the first 4- and the signal band is divided into two. As shown in FIG. 5B, the first partial bus filter (2) provides a composite color video signal 8! Among them, a low frequency signal 8L including a signal indicating a luminance component is extracted. The band of these 4 low frequency signals 8L does not need to be particularly selected to about 3MJ7 as in the conventional case, but is arbitrary.

In the example shown in FIG. 5, the frequency is the same as the conventional one (3!1 JHz is selected).

On the other hand, the Jll bypass filter (3) extracts a high-frequency signal 8H containing color signal components from the composite color video signal 8■, as shown in FIG. 5CK. Therefore, this high frequency signal 8H includes both a color signal component (carrier color signal) and a high frequency luminance signal component. and.

The cutoff frequency of the band of this high frequency signal 8H is selected so that it partially overlaps with the high frequency component of the low frequency signal 8L. Therefore, the bandwidth wH of the high-frequency signal sH divided by the I-I bus filter (3)K is wider than that of the conventional one.

The low frequency signal 8L is angularly modulated, for example, FM modulated, by a modulator (4), amplified by a recording amplifier (5), and then recorded by a rotary recording head HRLK on a chip (6). The high-frequency signal sH containing the color signal C is converted to a low frequency by a frequency converter.
The frequency (approximately 1.2 MHz) is selected as the low frequency conversion frequency, so in this case, the bandwidth of the high frequency signal 8H is 1.2 MHz. O
It can be expanded by MHgQ degree ★.

The frequency-converted high frequency signal 811C is angularly modulated, for example, FM modulated, by a modulator (8), and then amplified by a recording amplifier (9) and then by a recording head HRII.

It is recorded on a recording track different from the above-mentioned low frequency signal recording track.

Next, the playback device (to) will be explained.

FM low frequency signal SL-FM recorded on the first track
is reproduced by the reproduction head 1 (pt), amplified by the reproduction amplifier al) K, and then demodulated by the FM demodulator a. The demodulated low frequency signal 8L is supplied to a second 1-pass filter alK to limit the band as desired. The extraneous content that should be restricted will be discussed later.

FM high frequency signal sB-FM recorded on the second track
Similarly KF! While being reproduced by the raw head HPil, it is amplified by the reproduction amplifier (141) and then reconstructed by the FM demodulator.Then, this demodulated high frequency signal 8H
C is the subcarrier frequency 3.C in the frequency conversion aa.
After being reconverted to a signal centered at 58 MHz, it is band-limited in a second /1 pass filter αη as desired.

Well, the second low-pass filter α3 is #! Figure 5B
As shown by the break in the first loaf 5 filter (2
) has narrower band characteristics than the frequency band of

In this example, the cutoff frequency fC remains at 2.7 MHz. On the other hand, the band characteristic of the second /% pass filter αD is also selected to be narrower than that of the first pass filter (3), and is indicated by the broken line in C in the same figure. 5, its cutoff frequency is selected to be the same as the cutoff frequency fc of the third single-pass filter α.Therefore, the above-mentioned first bypass filter (3) has a cutoff frequency at least near the cutoff frequency fc. The bandwidth WR is determined in 5 so that the signals of

2nd f) Low pass filter α3
If the frequency characteristics of IHA x NILTER aη are selected as described above, the overall frequency characteristic of ``rS'' including both becomes flat as shown by the solid line in Figure 6. The time axes of the high frequency signal 8LO and the high frequency signal 810 outputted from the second bypass filter aη are corrected in the a field of the time axis adjusting circuit α, respectively.

That is, as mentioned above, the composite color video signal S! By band-dividing the luminance signal, the luminance signal is distributed across the low-frequency signal 8L and the high-frequency signal 8H, but since these signals 8L and 8M pass through the signal transmission system on each side, the delay times of the two are relative to each other. Different. For this purpose, the playback device (to) is provided with time axis adjustment circuits αS and aS, respectively, and different reference signals (for example, A burst signal is inserted into the low-frequency signal SL, and a horizontal synchronization signal is used with the high-frequency signal SHE), and the time axis is adjusted based on these reference signals during playback so that the delay times of both accurately match. It is done.

As the time axis adjustment circuit Q8 (II), a circuit using a CCD or the like as a variable delay element can be used.

After the time axis has been adjusted, both are combined in a combiner Qυ to reproduce a composite color video signal 80.

Note that the frequency characteristics of the first low-pass filter (2) and the first no-bus filter (3) are compared to the frequency characteristics of the second low-pass filter I and the second no-bus filter aη. If each is selected to have a sufficiently wide band characteristic, the low-frequency signal 8L that has passed through the second low-pass filter I
The high frequency signal 810 that has passed through the filter aη and the second filter aη is the composite color video signal 8! supplied to the terminal (1). Figure 7 is an example of the second filter (Q?), which has the same frequency characteristics as the signal obtained by directly feeding these filters to the fins. In order to match the cut-off frequency fC of the low-nox filter 0, a 60-no-5 filter (2) with the same characteristics as this filter I is used. Then, as shown in the figure, an inno(-ta) Q4J and a delay element (c) are provided, and the frequency-reconverted high-frequency signal sH is supplied to a low-pass filter 〇 and a delay element (c) K to be synthesized as shown in the figure. When synthesized by a filter, a second low-pass filter α whose cut-off frequency is equal to the cut-off frequency fC of the second low-pass filter αJ is obtained.
η can be constructed.

In the embodiment shown in FIG. 4, a composite color video signal is used as the video signal input to terminal (1).
When the luminance signal and color signal exist independently, tc4%
These signals can be used as human power input signals. Figure 8 i-L is an example of a circuit system used in that case. However, in this example, the configuration is such that both the luminance signal Y and the color signal C can be conveniently used even when they are separated or when they are frequency multiplexed like a composite color video signal.

In this example, the luminance signal Sy i)% is supplied to a terminal (30Y) provided between the first 4-Has filter (2) and the modulator (3). As the luminance signal 8Y, for example, a luminance signal before being combined with a color signal 80K formed by a television camera is used. Therefore, the 911th
As shown in , this luminance signal 8Y is a composite color video signal 8
This is a wider band signal than the luminance signal Y obtained by dividing X.

Further, a color signal 8C is supplied to a terminal (3QC) provided between the first pass filter (3) and the frequency converter (7). This color signal 8C also uses a signal before being frequency multiplexed with the brightness signal sy, and therefore this color signal 8C does not include the brightness signal SY at all.

゛The luminance signal 8 supplied to the terminal (soy) s (aoc)
The Y and color signals 8c are each subjected to the same signal processing as described above, and then sent to different tracks by the respective heads HRL e HRH.

The playback device (Ten) also has a configuration similar to that described above, but
Since this embodiment has a dual-purpose configuration, a pair of low-pass filters (IM, )* selected to have frequency characteristics as shown in FIG.
(13B) is provided as the input video signal [luminance signal 8
! When using color signal 8C, K)! .

Broadband low-pass filter of about 4.5MHz (13
A) is selected and composite color Eirin signal 8! When using the frequency characteristic used in the embodiment shown in FIG. 4, the frequency characteristic used in the embodiment of FIG. 4 is also selected as a low-pass filter (13B). (To) is the selection switch.

Note that when only the luminance signal sy and the color signal 8c are used, of course the filter selection system as described above becomes unnecessary, and the time axis adjustment circuit or al, and in some cases, the second bypass filter aη is also required. becomes unnecessary. Since the color signal SC does not include a luminance signal, the adjustment circuit α81 is
．． (This is because there is no need to provide 1'J to correct the time difference between the two signal transmission systems.

By configuring the recording and reproducing device (a) as described above, all of the conventional drawbacks can be completely eliminated.

In other words, in the ζθ recording system, a signal indicating the luminance component and a signal indicating the color component are extracted from the input video signal, processed and recorded, and after playback, these signals are reprocessed and then combined. In particular, even in the case of the first embodiment, since the blue signal band is simply divided into two by separating the luminance signal and chrominance signal as in the conventional method, it is possible to separate the luminance signal and chrominance signal band. You can record without any restrictions. Therefore, signal processing can be performed while maintaining a wide band, resulting in high quality l
j image can be reproduced.

Also, since this recording method does not use a Y/C separation method as shown in Figure 2, cross colors naturally do not occur.
Furthermore, since the signal indicating one composite component is processed and recorded separately from the signal indicating the luminance component, the alternating current bias signal of the signal indicating the color component will not fluctuate due to Bell's carbonization in luminance. , so there is no deterioration in image quality.

The present invention relates to a rotating magnetic head device in a brass device that employs such a special recording method, and FIG. 10 shows a variant example of the 0-rotating magnetic head 'drum or disk. A pair of magnetic heads HRLI' and Hiu for recording FM are installed with an angular spacing of approximately 180 degrees, and these pair of magnetic heads HRLI and HRIJK are placed close to each other to record high-frequency signals aH-FM. A pair of magnetic heads HRHI for recording
*HRH2 are also mounted with an angular spacing of approximately 18o0; these magnetic heads HRLte arranged close to each other
The mounting position of HRHI is selected so that the magnetic head HRLI for recording low-frequency signals is ahead of the magnetic head HRHI for recording high-frequency signals in the rotational direction. Therefore, the pair of magnetic heads HRIJ *H812 on the other side
Also, the magnetic head HRL2 is placed rotationally ahead. The reason why the head seal breaking position is specified in this way will be described later.

Note that a pair of magnetic heads HRLI are arranged close to each other.
-HHBl is K as shown in FIGS. 11 and 12.

Head base (42A) so that it is on the same rotation plane
e (42B) K can be installed. The other 6 magnetic heads "R"
The same applies to IJ tHRHI. However, illustration is omitted. (I3 is head base C-42A) * (42B)
mounting board, which is attached to the rotating trim or disc. The head mounting interval W is selected to be a distance equal to nH (H is one horizontal scanning period, n is a positive integer, and n is about 9).

In addition, the winding direction of the magnetic tape (6) on the rotating drum is Ω winding in this example as shown in FIG.
(4 da) * (45B) is a guide post.

FIG. 13 is a diagram showing the track pattern seen from the pace side of the magnetic tape (6) when the magnetic heads HIILI and HRL are placed before the magnetic heads HRH1 and HRiit, where TLI and TL are the magnetic heads HRI, 1
, HRL2K, and TH and T indicate tracks formed by the magnetic head H3lleHRIImK. A video signal for one file and one λ card is recorded on one track.

Since the low-frequency signal SL is a signal that includes components representing the luminance signal as described above, the low-frequency signal SL contains a composite synchronization signal (equalized pulse, equalization pulse,
sit direct synchronization signal, etc.). Similarly, since the high frequency signal 8HK does not have a special m peak that should be removed from the composite synchronization signal, it includes a composite synchronization signal whose part is used as a reference signal.

Therefore, the FM modulated low frequency signal 81 . containing such a composite synchronization signal is generated. - When recording FM and high frequency signals SR-FM, head switching is considered.

Therefore, the low frequency signal 81. -The FMK site is set so that the vertical planking period is placed on the head scanning start side, and the recording is performed with some overlap, so the contents recorded on the destination rack are as shown in Figure 13. . In the figure, the period of time indicated by a dot is: i1 [Blanking period (21
H period), the shaded area indicates the vertical synchronization signal.

When the low-frequency signal SL-PM is set so that its vertical blanking period is at the beginning of the track, the following magnetic heads HRHI and HRHIK record the low frequency signal SL-PM.
The vertical blanking period of the high frequency signal SR-FM is located at the rear end of the track TH1*THR,
The remainder is recorded in the first half of the next track.

Now, the signal is 81. - Since both PM and SR-FM are recorded with the vertical blanking period function number H overlapping, when the A magnetic head HPLI for reproduction starts scanning the track TLI, the HP output of the other magnetic head is still scanning the latter half of the track TIJ/), so the head switching timing between the magnetic heads HPLI and HPL2 is in the interval where the vertical synchronization signal can be obtained, in this example, the signal overlap interval ( Straight line'l
m '2).

With ζ5 and K2, the skinny error can be almost completely converged before moving to the effective plane. In other words, the convergence speed of the AFC circuit installed in TV receivers varies from several Hz to several 10 Hz, but if the head is switched as early as possible before the vertical synchronization signal, most of the This is because the skew can be completely converged by #l during the vertical blanking period.

Note that if the switching point between the magnetic heads HPLI and HPL2 is selected at the position '1 e G K shown in the figure, the magnetic head HPill for reproducing high-frequency signals is located on the track indicated by the broken line, so the magnetic head )lpnt is also magnetic head HPL
It is better to switch to switching position 1 of I. If the magnetic head HPHI at the switching position 11 is HP'HI, then the other magnetic head HPH2 is H'PH2.

This switching position is quite late in the vertical synchronization signal with respect to the track TH2, but since the signal indicating the color component, that is, the high frequency signal sH is recorded on the track TH2, there is no problem of skew.

Therefore, in this case, there is no problem even if the head switching timing is set in the latter half of the vertical synchronization signal.

By the way, in the present invention, when the magnetic head HRL for recording the low frequency signal SL-FM is placed in front of the magnetic head HRH for recording the high frequency signal 8M-FM, or the magnetic head HRH for recording the high frequency signal 8M-FM is selected, the following will be described. 5 problems arise.

That is, when the magnetic head HRH is placed in advance, the track pattern including the vertical blanking period is #11.
4 to 5, and if the head switching timing is selected in the same way as in the case of FIG. Imm I will not be able to completely converge my extrasexual skinny. Therefore, it is not preferable to put the magnetic head HRH ahead.

As explained above, the present invention adopts a special recording method, and when recording the low frequency signal SL-FM and the high frequency signal SH-PM on separate tracks, the magnetic head HPL for recording the low frequency signal is used. Magnetic head HPH for high frequency signal recording
Position '1 # shown in Figure 13.
Since the head is switched in step 2, the skew can be almost certainly converged outside the effective screen.Therefore, no skew distortion occurs.

[Brief explanation of the drawing]

1 to 3 are diagrams for explaining a conventional example, FIGS. 1 and 8 are system diagrams showing an example of a recording device according to the present invention, and FIGS. 5, 6, and 9 are My husband's theory of operation lid
7 is a system diagram of the bypass filter, FIG. 10 is an explanatory diagram of the rotating magnetic head device, FIGS. 11 and 12 are diagrams showing the state of the magnetic head, and FIGS. FIG. 14 is a diagram showing a track pattern used to explain the present invention. (2), 13 it low pass filter, (3),
αη is a Neubus filter, (4), (8) is a modulator, aa, α9 is a demodulator, (7). or a frequency converter, Sl is a composite color video signal. sy is a luminance signal, Sc is a color signal, HRL (HRLI
, HRL Ri. HRH (HRHI, HRH recording magnetic head, HPL (HPLI, HpLz), HPH (
HPHI, HPH2) is a magnetic head for reproduction, '1
*'2 is the head switching position. Figure 10, Figure 11 Figure 12 Htttt taLt

Claims (1)

[Claims] A signal indicating a luminance component and a signal indicating a color component are extracted from the input Eirin signal, the signal indicating the luminance component is angularly modulated, the signal indicating the color component is frequency-converted to a low frequency band, and then angularly modulated. A signal indicating a modulated luminance component and a signal indicating a color component are recorded on separate tracks, and
5. A recording device in which magnetic heads are scattered such that the magnetic head for recording the signal representing the luminance component precedes the magnetic head for recording the signal representing the color component.