JPS5888826A - Signal recorder - Google Patents

Abstract

PURPOSE:To realize easy and accurate tracking in a reproduction mode, by recording discriminating signals which are different from each other between a pair of tracks and are equal to each other between the tracks contiguous with each other for a recording medium which is driven by a pair of rotating heads provided closely to each other. CONSTITUTION:The discriminating signal f1 or f2 is applied to a pair of rotating heads 5a and 6a as well as a pair of rotating heads 5b and 6a which have different azimuth angles and set closely to each other and via a superposing circuit, respectively. Then the signals f1 and f2 which are different from each other between a pair of tracks f5a1 and f6a1, f5b1 and f6b1, and f5a2 and f6a2- respectively are recorded on a magnetic tape 17. While the signal f1 or f2 which are equal to each other between the contiguous tracks of contiguous pairs of tracks is recorded on the tape 17. In such a recording system, tracking is performed in a reproduction mode in accordance with the difference of crosstalks between the signals f1 and f2. Thus the same tracking system is used regardless of the presence or absence of a guard band to ensure the easy and accurate tracking.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal recording device, and when an information signal is recorded by a rotary head, a pair of closely disposed rotary heads having a gap are used to record information signals from each other. By recording a second identification signal together with an information signal in a pair of adjacent tracks, it is possible to record a pair of recording track patterns regardless of the presence or absence of a guard band between the immediately previous recording track pattern recorded in a pair and the pair of recording track patterns to be recorded next. First, it is an object of the present invention to provide a signal recording device that can cause a rotary head to perform follow-up scanning on a recording track with a gap during reproduction by a similar control operation.

In helical scan type VTRs, due to variations in the tape running mechanism, the recording/tracks are curved, which is unique to that VTR. During special playback, in which the tape is played back at a different speed from the tape running speed, the rotary head cannot accurately scan the recording track, and noise may occur on the playback screen.

For this reason, conventionally, a rotary head is displaced by a head moving mechanism in a direction perpendicular to the longitudinal direction of the recording track (track width direction) to correct the track deviation and accurately scan the recording track with a one-rotation head. Various so-called auto-tracking methods have been proposed, but these methods employ different methods depending on the presence or absence of a guard band.

In other words, as shown in FIG.
A track pattern as shown in FIG. 3(m) is recorded on the magnetic tape 3. In Figure 2 (mu), %tl e
t2 e ti # ti e... are recording tracks which are recorded obliquely with respect to the longitudinal direction of the magnetic chip 3, and a guard band is formed between adjacent recording tracks. Strictly speaking, in FIG. 1(m), another auxiliary head is provided, and the track tl.

A method of recording another track for synchronizing signals between t2, 1ffisiI, etc. has been implemented, but since it has no direct relation to the present invention, its explanation will be omitted.

When reproducing a magnetic tape having the track pattern shown in FIG. The wobbling method is used to detect deviations. This wobbling method uses a short period sine wave synchronized with the rotation of a rotating drum to mechanically move the rotating head in the track width direction during playback.

A rotating head draws a sinusoidal scanning locus for one recording track, and detects the amplitude difference of the PM reproduction signal at K between adjacent positive peak points and negative peak points in this scanning locus. This is a method of detecting track deviation.

On the other hand, as shown in FIG. 1(B), two rotating heads are arranged 180 degrees adjacent to each other (opposed to each other) around the rotation axis of the rotating drum 2, and have gaps with different azimuth angles. In VTRs with la and lb, the rotating head l
A track pattern without a guard band as shown in FIG. 2(B) is recorded on the magnetic tape 3 using a and lb. In FIG. 2(B), tl.

il a t6 is a track recorded by the rotary head 1a, and s i2 e ti t ti is a track recorded by the rotary head 1bK. This figure 2 (B
In a device that plays back a magnetic tape having a track pattern indicated by IK, when the above-mentioned wobbling method is used to detect track deviation, crosstalk from FM playback signals of adjacent tracks causes FM playback from the track to be played back.
The wobbling method is not used because it affects the playback signal and degrades the image quality of the playback screen, and the vibration of the rotating head causes time axis fluctuations in the playback signal, which appear as curves and color unevenness on the playback screen. In this case, an identification signal was recorded on each track, and track deviation was detected by the level of the identification signal reproduced as KII contact track crosstalk during reproduction.

In this case, the above identification signal is recorded on the tracks on both sides of the track to be reproduced because it is necessary to identify which side of the tracks on both sides of the track to be reproduced and to displace the rotary head in the direction of the track to be reproduced. The identification signals to be used must be different, and in order to maintain this relationship at all times, K needs four types of identification signals, and for this reason, four different frequencies ft I fi # fM # f4 are sequentially cycled through. There was something to record.

However, both the wobbling method and the identification signal recording method described above can only be used to detect the track deviation of one of the track patterns shown in FIG. This method has the disadvantage that it cannot be applied to a recording/reproducing apparatus that selectively forms the track patterns (A) and (B).

The present invention eliminates the above-mentioned drawbacks, and an embodiment thereof will be described below with reference to the drawings of FIGS. 3 to 8.

FIG. 3 is a plan view of an embodiment of the rotary head of the uninvented device attached to the rotary drum, in which the heads Sa and Sb face each other at 180 degrees and have a gap with the same azimuth angle, and the heads Sa and Sb face each other at 180 degrees. The heads 6a each have a gap having an equal azimuth angle.

@b is the bimorph T and support part 17 shown in FIG. 4, respectively.
It is attached to the rotating drum 4 via.

Historically, the heads 5a and lia, and the heads Sb and 6b are respectively mounted close to each other and constitute rotary heads each having a pair of gaps. The heads 5a and 6a each have a gap with a different azimuth angle (Sb, 6
The same goes for b). Furthermore, as shown in FIG. 4, the rotary head composed of the heads Sa and 1IaK is attached to the tip of the bimorph 1, which is displaced upwardly and downwardly (i.e., in the track width direction) using the support section 8 as a fulcrum by a tracking voltage. In addition, the support portion 8 is fixed to the rotating drum 4. Therefore, the rotary head composed of the heads 5a and SbK and the rotary head composed of the heads @a and 6b rotate integrally with the rotary drum 4, and the heads Sa and @a and Sb and @b respectively track the tracks. Historically, the displacement of the rotary head composed of heads 5a and 6a in the track width direction is performed independently of that of the rotary head composed of heads 5b and 6b. It will be done.

The above-mentioned heads Sa and 6a are installed with a slight difference in height so that a guard band is not formed between the tracks recorded by these heads (head 5b
and 6b).

Figures 3 and 4: Heads arranged in a pressure water configuration! ! a
, Sb, 6a, and 8b, the signal recording device of this embodiment is applied to, for example, a VTR that takes into consideration compatible playback between the NT80 system and the PAL system or the 8E○muM system, and is used for recording televisions. Depending on the field frequency of the system, a recording track pattern is formed as shown in FIG.
The Eirin signal for the cl field is transmitted to the same rotating drum 4 and head 5m, 5b, regardless of the difference in television system.
If 6a and 6b are used in common, the field frequency is 110 H2 (or 51Li14 H,)
- When recording a video signal with 525 scanning lines, the rotary drum 4 is rotated at 30 rps, while when recording a video signal with a field frequency of 50 Hz and 625 scanning lines, etc.
(When recording a 3AM video signal, the rotating drum 4 is
rl) rotated by 8. Therefore, when the tape running speed is constant, when recording is performed by rotating the rotating drum 4 at 25 rps, the recording track pattern shown in Fig. When recording, a recording track pattern shown in FIG. 5 (I) K is obtained.

Next, the operation of the recording system of the apparatus of the present invention will be explained.
The figure shows a block system diagram of the main parts of an embodiment of the device of the present invention. In this figure, the same parts as in FIGS. 3 and 4 are given the same reference numerals, and their explanations will be omitted. In FIG. 6, the color image information to be recorded is a luminance signal and two color difference signals. Here, regarding the color difference signal, either a composite color difference signal obtained by inverting the phase of one of the first and second color difference signals every horizontal scanning period and then adding it to the other color difference signal, or A composite color difference signal is obtained by amplitude modulating the color difference signal and then frequency division multiplexing it with the other color difference signal. After the luminance signal and the above-mentioned composite color difference signal are frequency-modulated from side to side, the frequency-modulated luminance signal is supplied to the superimposition circuit 13 and the SSK through the input terminal 9, while the frequency-modulated color difference signal is supplied to the superimposition circuit 13 and the SSK through the input terminal 10. The signals are supplied to superimposing circuits 14 and 16, respectively. On the other hand, an oscillator (not shown) generates first and second signals having different frequencies within an empty frequency band lower than the respective frequency bands of the frequency modulated luminance signal and the frequency modulated color difference signal. Identification signals f1 and f2 are oscillated and output, of which the first identification signal f1 is supplied from the input terminal 11 to the superimposition circuit 13 and tSVC, respectively, while the second identification signal f2 is supplied from the input terminal 12 to the superposition circuits 14 and 15. supplied respectively. The reason why the first and second identification signals f1 and f2 were selected to be low frequencies is because the azimuth loss effect is generally smaller at low frequencies (cross).
This is because it is easy to be reproduced as an image.

As a result, a multiplexed signal with a frequency spectrum as shown in FIG. 1(m), which is obtained by frequency division multiplexing the frequency modulated luminance signal and the first identification signal f1, is taken out from the 1 multiplexing circuit 13, and 1iNi? It is supplied to the head Sa.

In addition, Fig. 1 (A) to (D) and Fig. 1 (M) to below
In (D), FM-Y indicates the frequency spectrum of the frequency modulated luminance signal, and FM-0 indicates the frequency spectrum of the frequency modulated color difference signal. A multiplexed signal of the frequency spectrum shown in FIG. 1(B) consisting of the frequency modulated color difference signal and the second identification signal f2 is taken out from the superimposing circuit 14 and supplied to the head 6a. Also, from the superimposition circuit 15, the frequency position I
ll! A seventh signal consisting of 1 for the IN degree signal and the second identification signal.
A signal is extracted from the frequency spectrum as shown in the figure (01K) and supplied to the head 5t+.Additional Kl cost circuit 1
From the head 6, a multiplex of the frequency spectrum as shown in FIG. 1 (Dl) consisting of the frequency modulated color difference signal and the first identification signal f1 is extracted and supplied to the head 6b.

As mentioned above, the heads 5a, 6a, 5b, and 6b form a continuous turn as shown in FIG. Tracks t6a 1 and f on tape 11
:4al are simultaneously recorded by the heads Sa and 6aK, respectively, then tracks t6b1 and t6b1 are simultaneously recorded by the rotating heads Sb and 1lbK, respectively, and then tracks tsaz and tml are simultaneously recorded by the rotating heads Sa and @, respectively. A record is formed from aK. Thereafter, a pair of tracks are sequentially formed in the same manner as above.

In addition, in FIG. 5(mu)*(Bl, f1sf2 indicates the track where the first identification signal f1 is recorded and the track where the second identification signal f2 is recorded.

Therefore, as can be seen from FIG. 5(m), IBI, and FIG. 1, the frequency modulated pJ luminance signal and the frequency modulated color difference signal are each recorded for one field on adjacent tracks, and are each recorded on one track. recorded every other time, while the first
The second identification signal fl*f2 is recorded separately on each of the two simultaneously recorded tracks, and is repeatedly recorded on two tracks at a time. This results in
As will be described later, even if the recording track pattern has a guard band as shown in FIG.
Even if a guard band is not formed as shown in Figure (Bl), track deviation can be detected using the same method and auto-tracking can be performed.

Next, the operation of the reproducing system for the magnetic tape 11 recorded as described above will be described. [FIG. 11 shows a block system diagram of an example of the main parts of the magnetic reproducing apparatus. In this figure, the same parts as in FIGS. 3 and 4 are designated by the same reference numerals, and their explanations will be omitted. Furthermore, the reproduction system for the luminance signal and color difference signal is not shown.

In FIG. 8, 7' is an immorph whose head sb and -b are each integrally displaced in the track width direction, and has the same structure as the bimorph 7. Head.

5a and ia simultaneously reproduce tracks 1;

Next, heads sb and 6b are on track t51) 1 v t
4b1 respectively at the same time, and then head 5a.
and 6a simultaneously reproduce tracks tk2 #tk2, respectively.

Here, heads 5a and ia are tracks t51)1 #
1;! 'l) Play 1, head sb, ・b plays track tIllat * t'al and tkg, t4a2
can also be played. Heads 5a and 6b accurately scan and reproduce the above tracks, respectively.
When this happens, the crosstalk component from the adjacent track mixed into the reproduction signal of the head can be considered to be substantially a pole.

Here, a track i is reproduced by a pair of heads sa and a, or sb and @brc, which play back simultaneously.The track i is reproduced by a pair of rotating heads having gaps of different azimuth angles as described above. As for the crosstalk components from adjacent tracks mixed into the signal, generally high frequency frequency modulated luminance signals and frequency modulated color difference signals are not reproduced from adjacent tracks due to the azimuth loss effect, but are reproduced by low frequency first or second signals. Identification signals f1 and f2
is included as a crosstalk component.

In FIG. W, 8, the reproduced signal reproduced by the head Sa is supplied to the f2 detection circuit 11, where the second identification signal f2 is frequency-selected, subjected to envelope detection, and extracted. Applied to the inverting input terminal. Further, the reproduced signal reproduced by the head 6a which performs reproduction simultaneously with the head 5a is supplied to the first detection circuit tSVc, where the first identification signal f1 is frequency-selected, envelope-detected and extracted, and then sent to the differential amplifier. The output signal of the differential amplifier 22 is applied to the bimorph T as a driving voltage of the bimorph 7. On the other hand, during the current period of the heads 5b and 6bK, the first signal is applied to the reproduction signal of the head 5b. The identification signal f1 is frequency-selected by the f1 detection circuit 20, envelope-detected, and applied to the non-inverting input terminal of the differential amplifier 23, and the acupuncture-specific signal f2 of 8g2 is detected from the control signal of head b as f2. After selecting the frequency, the detection circuit 21 performs envelope detection and applies it to the inverting input terminal of the differential amplifier 230.The output signal of the differential amplifier 23 is applied with a bimorph fVC, and is sent in a direction according to its polarity and at its level. Displace it by the amount of displacement according to.

Now, the head 5b is reproducing the track t5b1 shown in FIG. 5(A) or (B) K, and at the same time, the head 6b is reproducing the track t5b1 shown in FIG. When reproducing BL, heads sb and 6b are respectively shown in FIG.
Assuming that the reproduction is performed with a track deviation in the direction of the neutral force, the head sb scans a part of the track tibt, so the frequency spectrum of the reproduction signal of the rotary head 5b is different from the track t5bl as shown in FIG. 9 (C1IC). The reproduced signal (FIG. 1 (shown at 01K)) 1 identification signal f1 from the VC track t6b1 is mixed in as a crosstalk component, and this crosstalk component element 1 is envelope-detected by the f1 detection circuit 20.

At the same time, if the track pattern is as shown in Figure 5 (m), the head ib approaches the track taazllll, and in the case of the track pattern S (Bl), a part of the track tk1 is also scanned at the same time. The frequency spectrum of the signal is shown in % as shown in FIG.
is mixed in as a crosstalk component.

This crosstalk component element 1 is the playback track t4bI K
Since it has the same frequency as the recorded identification signal f1, it is not possible to identify only the crosstalk component (note that
When reproducing the track pattern shown in FIG. Therefore, at this time, a voltage proportional to the amount of track deviation is applied only from the f1 detection circuit 20 to the input terminal of the differential amplifier 23.
The output signal drives the bimorph 7' to displace the heads Sb and 6b to the left in FIG. 5 (M) or (B), respectively.

On the other hand, heads 5b and 6b are respectively shown in FIG.
During playback, the head 5b approaches the track tmz side and the head 6b moves toward the track tmz.
K means that a part of the track tsbt is being reproduced.

Therefore, the reproduction signal of the head @b has the frequency spectrum shown in FIG. 9(D) A frequency spectrum as shown in K, of which the crosstalk component 2 is applied to the inverting input terminal of the differential amplifier 2s via the f2 detection circuit 21. On the other hand, the reproduction signal of the head sb is t5m) Figure 1 from 1 (
The sum of the reproduced signals of the frequency spectrum indicated by C1K is the one in which the identification signal f2 of the irises 2 recorded in the track thaw K is reproduced and mixed as a crosstalk component, but the crosstalk component element 2 is recorded in the reproduced track tlsb11c. Since it has the same frequency as the identification signal f2, only the crosstalk component cannot be detected, and since the f1 detection circuit 2G is connected to the output end of the head sb, the differential amplifier 2
3 is not supplied. Therefore, at this time, only a voltage at a level proportional to the amount of track deviation is applied from the f2 detection circuit 21 to the differential amplifier 21, and at a level corresponding to this level and corresponding to the input 11 of the input terminal. The polarity signal is taken out from the differential amplifier 23 and output to the bimorph rVc.
In this way, the heads 5b and 6b are displaced to the right in FIG.
As a result of controlling so that no signal is taken out from the track t5bz and t41)1, accurate tracking control is performed without track deviation on the tracks t5bz and t41)1.

This is exactly the same for the heads 5a and 1iaK.

In addition, FIG. 9 (Al indicates the frequency spectrum of the reproduced signal of the head Sa when the heads Sa and lla are shifted to the left in FIG. 5 (M) or (B), and the second identification as a crosstalk component This shows that the signal f2 is mixed in, and Fig. 9 (B) shows head Sa, and @a shows Fig. S (m).
Or (B) shows the frequency spectrum of the reproduced signal of the head @a when shifted to the center left direction, and shows that the first identification signal f1fJ"14 is present as a crosstalk component.

If you organize the above, it will be as shown in the table below.

Magnetic tape I recorded by the one-track investigation device in this way
The track pattern on T is as shown in Figure 5 (B) K.
If there is no guard band, auto-tracking can be performed by effectively utilizing crosstalk components reproduced from tracks on both sides of each track to be reproduced by a rotary head having a pair of gaps that reproduce simultaneously. 5
As shown in Figure (M) K, even if there is a guard band, one of the two rotary heads with a gap that performs playback at the same time is scanning with a deviation toward the guard band due to track misalignment. Although the crosstalk component is extremely small, from now on there is no need to obtain track deviation information, and since the other rotating head is simultaneously scanning two recording tracks, the crosstalk component from that rotating head is Since tracking control is performed using the guard band, auto-tracking can be performed without any problem using the same means as auto-tracking for a track pattern without a guard band.

In the above embodiment, the first and second identification signals f1 and f2 are continuous sine waves, but they may be recorded intermittently, for example, to be superimposed on the internal pressure during the horizontal blanking period or at other cycles. It may also be a signal other than a sine wave, such as a rectangular wave or a coded signal.Furthermore, when identifying based on a difference in frequency, it is not necessary to use IIC@, in short, it is clear from a video signal or other identification signal. Any signal form that can be distinguished is sufficient. Also, the first or second identification signal fl s f
2 as a crosstalk, from fWJ
Although it was designed to prevent the formation of guard bands between the tracks recorded and formed by the pair of rotary heads for recording the #IffK signal, it is desirable to have some guard bands in playback of the video signal. Therefore, if a slight guard band is provided between the tracks recorded by a pair of rotary heads having a gap that record signals simultaneously, the frequency of the first and second identification signals f1 and f2 will not have much of an azimuth loss effect. By selecting a sufficiently low frequency, even if there is a narrow guard band, the first or second identification signal f1 or f2 can be ignored as crosstalk.
can be reproduced well. In the above embodiment, the carrier wave center frequency of the frequency modulated luminance signal is approximately S MHL.

The carrier wave center frequency of the frequency modulated color difference signal is approximately 414HM.
The first identification signal f1 is approximately 500 kHz, and the second identification signal f2 is approximately 100 kHz.

Further, the head moving mechanism for displacing the rotating head in the track width direction is not limited to the one shown in FIG.
Alternatively, the rotary head may be dedicated to recording and reproduction, the head moving mechanism may be provided only to the reproduction rotary head, and the recording rotary head may be directly fixed to the rotating drum. Further, in the above embodiment, an example was explained in which two heads are arranged close to each other as a pair of rotary heads having a pair of gaps for simultaneous recording and reproduction. Of course, it may also be used as a head.

Furthermore, in the above embodiment, the information signals simultaneously recorded by a pair of rotary heads having a gap are a frequency modulated luminance signal and the other is a frequency modulated color difference signal, but the types of information signals and modulation methods are limited to these. Alternatively, multiplexed signals may be recorded on one recording track; for example, one recording track may record a multiplexed signal of a frequency modulated luminance signal and a low frequency conversion carrier chrominance signal, and the other may record one other information signal. may record an audio signal, and various other modifications are possible.

As described above, the signal recording apparatus according to the present invention records and forms a pair of tracks simultaneously at an angle with respect to the longitudinal direction of a tape-shaped recording medium using a pair of rotary heads having a gap arranged close to each other.

The first and second information signals are separately recorded on each of the pair of tracks, and the first and second identification signals in a signal form that can be identified as the first and second information signals are recorded on the pair of tracks. separately for each of the first and second
Since the identification signal is switched so that the same identification signal is recorded on each adjacent track of the pair of tracks recorded immediately before and the pair of tracks recorded next, the Gartband Whether you are recording a track pattern with a certain track pattern or a rack pattern (without guard bands), you can record using exactly the same auto-tracking method without having to use a dedicated auto-tracking method for each on the playback side. In particular, when applied to a recording/playback device compatible with each television system that selectively records and plays track patterns with guard bands and track patterns without guard bands, It is something that you have.

[Brief explanation of drawings]

Figure 1 (M) # (B) schematically shows each side of the rotary head of the conventional device attached to the rotating drum (rotating cylinder), and Figure 2 (Al # (B)) Figures 1 (M) and (B) K show each side of the track pattern recorded by the rotary head, respectively, and Figure 3 shows the state in which the rotary head of the device of the present invention is attached to the rotary drum (rotary cylinder). FIG. 4 is a plan view schematically showing an embodiment, FIG. 4 is a perspective view showing an embodiment of the main part of the device of the present invention, and FIG.
, (B) are diagrams showing each side of the track pattern recorded and formed by the apparatus of the present invention, Figure @6 is a block system diagram showing an embodiment of the main part of the apparatus of the present invention, and Figures 1 (M) to
(D) is a diagram showing each side of the signal frequency spectrum recorded by the device of the present invention, and FIG. 8 is a block diagram showing an example of the essential parts of a reproducing device for reproducing the magnetic tape recorded by the device of the present invention. , FIG. 9 (Al-(D) is a diagram showing the signal frequency spectrum for explaining the operation of FIG. 8, respectively. Sa, Sb, -a, @b...Head%7.Te...Bimorph, 9... Frequency modulation luminance signal input terminal, 10
...Frequency modulation color difference signal input terminal %11...First identification signal input terminal, 12...Second identification signal input terminal, 1N, 14, 111+, 16-...Superimposition circuit, 17- fi magnetic tape 1a, 21・f2
Detection circuit, 111.20...f1 detection circuit, 22
．． 23...Differential amplifier. Electricity 1 rA+Al (B1u 2nd i'JJ+A+ th', (Fig. Fit wave soft one order number one cycle number

Claims (1)

[Claims] A pair of tracks are tilted with respect to the longitudinal direction of a tape-shaped recording medium at the same time by a pair of rotary heads having a gap disposed close to each other to form recording, and first and second information signals are recorded on each of the pair of tracks. and separately record first and second identification signals in a signal form that can be distinguished from the first and second information signals on each of the pair of tracks, and and recording the second identification signal by switching so that the same identification signal is recorded on each adjacent track of the pair of tracks recorded immediately before and the pair of tracks recorded next. signal recording device.