JPS6321248B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a pilot signal recording and reproducing method,
Pilot signals for obtaining track deviation information are transmitted at different frequencies for adjacent tracks.
By recording the repetition frequency as an integer multiple of the horizontal scanning frequency and reproducing it,
The present invention can be applied to a helical scan type magnetic recording/reproducing device which is configured to be able to obtain correct track information even for large track deviations compared to conventional devices, and to control the displacement of the head in particular by tracking bends in the track. It is an object of the present invention to provide a suitable pilot signal recording and reproducing method.

In recent years, household helical scan type rotating head magnetic recording and reproducing devices (hereinafter referred to as "Hall VTR") have been developed.
Along with the improvement of magnetic tape and the increased sensitivity of rotating heads, recording and reproducing densities have been further increased, and tape speeds, track pitches, etc. have been reduced to about the same level as the conventional two-hour recording and reproducing system. 1/
Home VTRs with long recording and playback times of 6 hours have now been commercialized.
However, in home VTRs, where the tape running system is simplified to reduce costs, the high density described above is
It becomes difficult to follow the bending of the video track and stably maintain the required tracking accuracy, especially when playing back a magnetic tape recorded on another home VTR on another home VTR (so-called compatible playback). It is difficult to maintain stable accuracy, and currently high image quality cannot be obtained.

Therefore, as a method to solve the above-mentioned tracking problem associated with high-density recording and playback, and also to eliminate noise bars during special playback (trick play) of slow-motion playback, stay playback, and fast-motion playback volumes, we developed a rotating head. In recent years, home VTRs have been actively developed that are equipped with a head moving mechanism that displaces the rotary head on a plane perpendicular to its rotating surface and displaces the rotary head in a direction perpendicular to the longitudinal direction of the track (that is, in the width direction of the track). ing.

A platform equipped with such a head moving mechanism
In VTR, it follows the curve of the track,
Alternatively, in order to make the track follow the head scanning locus during special playback, which is performed at a tape running speed different from that during recording, information on the relative shift between the track to be scanned and the rotating head currently scanning the magnetic tape (track shift It has a tracking servo circuit that detects the track deviation information) and generates a tracking error signal based on the tracking error signal to correct the tracking deviation of the rotary head.Accurately detecting the above tracking deviation information is the key to correcting the tracking deviation. It is extremely important for

Conventionally, as a method for detecting the track deviation information, a pilot signal whose frequency is switched for each track recording unit is continuously sent to each track so that adjacent tracks are recorded at different frequencies. There have been various methods in which the frequency of the reproduced pilot signal is discriminated during playback, and track deviation information is detected from the playback level, but all of these methods use information signals (e.g. video signals) to be recorded and played back on the track. This has the disadvantage that the band of the information signal is limited by the pilot signal, and the band of the information signal becomes narrower accordingly.

On the other hand, during playback, the rotating head is vibrated in the width direction of the track at approximately 480 Hz, and track deviation is detected from fluctuations in the playback FM level of information signals recorded in the form of frequency modulated wave signals (FM signals) on the track. There is also a conventional method, but this conventional method has the disadvantage that the influence of fluctuations in the reproduced FM level may appear in the reproduced image, and that track deviation information cannot be obtained accurately for track deviations of one track pitch or more. had.

The present invention eliminates the above-mentioned drawbacks,
One embodiment will be described below with reference to the drawings.

FIG. 1 shows a block system diagram of an embodiment of a recording system according to the present invention. The method of the present invention uses the repetition frequency of the pilot signal as track deviation information.Therefore, since it is necessary to create a waveform with many fundamental wave components of the repetition frequency, the pilot signal waveform is not the same for the same track. Must be. Furthermore, when the method of the present invention is applied to a home VTR in which signals are recorded and reproduced using, for example, two rotating heads with different azimuth angles, the recorded pilot signal of the track for which track deviation information is detected is used to reproduce the adjacent track. Rotating heads with different azimuth angles allow for reproduction of crosstalk.
It is necessary to select a low frequency with little azimuth loss. However, from the viewpoint of effective use of bandwidth, the method of the present invention records the pilot signal in a portion corresponding to the horizontal blanking period of the video signal to be recorded, but the pilot signal is recorded in a portion corresponding to the horizontal blanking period of the video signal to be recorded. The remaining period is 6.4μsec
Therefore, the pilot signal cannot be set to a very low frequency.

In view of the above points, in the recording system of the present invention, the pilot signal is recorded in the following manner. In Fig. 1, the part surrounded by the dashed line A shows the repetition frequency of the pilot signal for each track, 1/2, 1/3, 1/5 times the horizontal scanning frequency _fH ,
The circuit section that switches and outputs 1/7 times, 1/2 times, 1/3 times, etc. is shown, and the part surrounded by one-dot chain line B is the circuit section that generates the frequency and waveform of the pilot signal. show. The color video signal input to the input terminal 1 is supplied to the recording signal processing circuit 2, where it is separated into, for example, a luminance signal and a carrier color signal.The luminance signal is frequency modulated, and the carrier color signal is converted into a frequency modulated luminance signal. After converting the frequency to a lower band than the band of , signal processing is performed to multiplex both signals. On the other hand, the input color video signal is processed by the horizontal period signal separation circuit 3 into a horizontal synchronizing signal a as shown in FIG. 2A or 3A.
is taken out and applied to a monostable multivibrator (hereinafter referred to as monomulti) 4.

Since the monomulti 4 outputs a trigger pulse at the start of the horizontal blanking period, it is triggered by the horizontal synchronization signal a, and as shown in FIG. 2B or FIG. A high level pulse b is output until However, the monomulti 4 can be omitted if the delay time of the processing circuit of the recording system is longer than the delay time of the pilot signal generation circuit B and the delay time difference is appropriate. mono multi 4
The output pulse b of 1/2 frequency divider 5, 1/3 frequency divider 6, 1/
The signals are supplied to a 5 frequency divider 7 and a 1/7 frequency divider 8, respectively, and are frequency-divided. As a result, the repetition frequencies are f _H /2, f _H / ₃ , f H /5, and f _H /5 from frequency dividers 5, 6, 7, and 8, respectively.
7, the second high level period is equal to one period of pulse b.
Pulses c, d, e and f shown in Figures C, D, E and F are taken out and applied to fixed terminals 9a, 9b, 9c and 9d, respectively, of changeover switch 9 in Figure 1.

The changeover switch 9 continues to be connected to a certain fixed terminal during one track formation period, and changes the fixed terminals 9a, 9b, 9c, 9d,
9a, 9b, . . . , so that the changeover switch 9
Only one of the frequency-divided pulses c, d, e, and f is selectively outputted from the common terminal 9e of the circuit, and is sequentially switched and outputted every track formation period, and is supplied to the gate circuit 10. .

On the other hand, the output pulse b of the monomulti 4 is passed through the phase comparator 11, the 1/16 frequency divider 12 and the flip-flop 1.
3 set terminals, respectively. Phase comparator 1
1 is a loop filter 14, a voltage controlled oscillator (VCO) 15, a 1/16 frequency divider 16, and a 1/5 frequency divider 1
7 and the well-known phase locked loop (PLL)
The pulse b and the 1/5 frequency divider 17
A phase comparison is made with the output pulse of the VCO 15, and an error voltage corresponding to the phase difference is applied to the VCO 15 through the loop filter 14 to variably control its output oscillation frequency. The VCO 15 has a free-running oscillation frequency that is 80 times the horizontal scanning frequency _fH , and outputs signals having the waveform shown in FIG. 3C to the 1/16 frequency dividers 12 and 16, respectively.

The 1/16 frequency divider 12 generates a pulse b with a repetition frequency f _H
A counter whose count value is reset to 0 at the falling edge of the horizontal synchronization signal a, and which always starts counting from the beginning of the horizontal blanking period.
As shown in FIG. 3D, a pulse k with a repetition frequency of _5fH is output to the reset terminal of the flip-flop 13 and the low-pass filter 18, respectively. Here, the frequency division ratio of the frequency divider 12 is the period that can be used for recording and reproducing the pilot signal in the horizontal blanking period (that is, as mentioned above, this is the horizontal blanking period excluding the color burst signal existence period). ,about
0.1 horizontal scanning period. ), the frequency of 5f _H was set to 1/16 of the value obtained, but it does not have to be this value. However, this excludes high frequencies where azimuth loss is large, and frequency divider ratios where it is difficult to create a pilot signal with the same waveform every time.

The pulse k is filtered by a low-pass filter 18 to remove second and higher harmonics (actually even harmonics are extremely rare, so third and higher odd harmonics) and becomes a sine wave m as shown in FIG. 3F. and is supplied to the gate circuit 19. This gate circuit 19 is configured to receive the output pulse of the flip-flop 13 as a gate pulse and to allow the sine wave m to pass only during the high level period of the gate pulse. here,
The flip-flop 13 is set at the falling edge of the pulse b (or a) and reset at the rising edge of the pulse k, so that the pulse l shown in FIG. 3E is at a high level for a period corresponding to the horizontal blanking period. Output. Therefore, the gate circuit 19
From this, a signal n having a waveform as shown in FIG. 3G is extracted, and this signal n is supplied to the gate circuit 10 and output from the gate as follows.

As described above, the gate circuit 10 selects and outputs repetition frequencies f _H /2, f _H /3, f _H /5, f _H /7 sequentially from the common terminal 9e of the changeover switch 9 for each track formation period. Since pulses c, d, e, and f of
A signal g with a repetition frequency f _H /2 shown in Figure G is output, and during the next one track formation period when the pulse d is applied, a signal h with a repetition frequency f _H /3 shown in Figure H is output, and During the next one-track formation period when the pulse e is being applied, a signal i with a repetition frequency f _H /5 shown in FIG. A signal j with a repetition frequency f _H /7 shown in J in the figure is output. Below, the above signals g, h,
The operation of cyclically switching and outputting i and j every one track formation period is repeated. Note that the signal g,
h, i, and j are not actual waveforms but schematically indicate the period of existence of the signal.

Signals g, h, taken out from the gate circuit 10
i or j is output for a period corresponding to the horizontal blanking period of the color video signal to be recorded,
The output signal of this gate circuit 10 is supplied as a pilot signal to a mixer 20, where it is multiplexed onto a portion of the frequency division multiplexed signal from the recording signal processing circuit 2 corresponding to the horizontal blanking period excluding the color burst signal existence period. Rotary head 21 (Actually, there are two rotary heads with different azimuth angles, and they are switched alternately to record or reproduce signals, but the rotary head that is currently recording or reproducing signals is always (Since there is only one, only one is shown in the figure.) Records are recorded by sequentially forming tracks that are inclined upward in the longitudinal direction on the magnetic tape 22.

FIG. 4A is an enlarged plan view of a part of the track pattern recorded by the recording system shown in _FIG .
~ _t6 shows six tracks recorded closely together without a guard band, a pilot signal g with a repetition frequency f _H /2 is recorded in track _t1 , and the track formed after _t1 t ₂ is the repetition frequency
A pilot signal h of f _H /3 is recorded, and a track t ₃ formed after t ₂ has a repetition frequency.
A pilot signal i of f _H /5 is recorded, and a track t ₄ formed after t ₃ has a repetition frequency.
A pilot signal j of f _H /7 is recorded, and similarly pilot signals g and h are recorded in each track of t ₅ and t ₆ . Also, among the two rotating heads having different azimuth angles, tracks t ₁ , t ₃ , and t 5 are recorded and formed by one rotating head, and tracks t ₂ , t ₄ , and _{t 6 are} recorded and formed by the other rotating head. This is illustrated by the slope of thin diagonal lines in FIG. 4A. Furthermore, in the track pattern shown in FIG. 4A, the horizontal synchronizing signals are recorded so as to line up adjacent tracks (so-called H-line recording).

Note that in the above recording system, the pilot signal frequency can be freely selected by the division ratio of the counter 17, but it is necessary to change the way the flip-flop 13 is reset or replace it with a mono-multiple that is triggered by pulse b. Must be.

Next, the operation of the reproduction system according to the present invention will be explained. FIG. 5 shows a block system diagram of an embodiment of the regeneration system according to the present invention. In the figure, magnetic tape 2
2 has a track pattern as shown in FIG. 4A, as described above, and the rotary head 21 reproduces the recorded signal. The reproduced signal is sent to preamplifier 2.
After being sufficiently amplified by 3, the reproduced signal processing circuit 24
Here, the signal is returned to the original color video signal and then output from the output terminal 25, while only the horizontal synchronization signal is extracted by the horizontal synchronization signal separation circuit 26. This reproduced horizontal synchronizing signal passes through monomultis 27 and 28, is converted into a gate pulse, and is applied to a gate circuit 29. The monomulti 27 determines the location of the gate, and the monomulti 28 determines the width of the gate. The gate circuit 29 gate-outputs only the portion corresponding to the horizontal blanking period of the output reproduction signal of the preamplifier 23 in response to the gate pulse from the monomulti 28. This is the fourth
When reproducing a magnetic tape 22 having a track pattern recorded in a so-called H arrangement as shown in FIG.
A gate circuit 29 is provided in front of variable band filters 31 and 32 for selecting the pilot signal frequency. but,
When it is desired to construct a circuit at a lower cost than to improve the S/N, or when reproducing a magnetic tape with a track pattern that is not recorded in a so-called H arrangement, the monomultis 27 and 28 and the gate circuit 29 can be omitted. .

The reproduction signal of the portion corresponding to the horizontal blanking period taken out from the gate circuit 29 is passed through the low-pass filter 30.
is supplied to the subsequent variable band filter 3.
1 and 32 are switched capacitor bandpass filters, and if this is configured to sample the input signal at half the clock frequency, unnecessary high-frequency components will be generated, so it is necessary to remove them in advance. After selecting and extracting only the frequency components from which the frequency of the pilot signal can be obtained, the frequency of the pilot signal having a predetermined repetition frequency is selected and supplied to variable band filters 31 and 32, respectively, and reproduced as crosstalk.

In order to select the frequency of the pilot signal, the center frequency of the passband must be f _H /2, f _H /3, f _H /5, f _H /7.
It is also possible to prepare filters for each band and use them by switching between them depending on the playback track, but in this embodiment, a variable band filter whose passband center frequency can be freely varied by an external control signal is used. There is. Such variable band filters include switched capacitor band pass filters, filters using charge coupled devices (CCD), etc. Here, as an example, the center frequency of the pass band is 1/108 of the clock frequency. The following example uses a switched capacitor bandpass filter in which the center frequency of its passband is varied by the clock frequency generated as follows.

The horizontal synchronizing signal separated by the horizontal synchronizing signal separation circuit 26 described above is supplied to the phase comparator 35, where the phase is compared with the horizontal scanning frequency signal from the 1/108 frequency divider 38. The phase comparator 35 includes a loop filter 36, a VCO 37, and a 1/108 frequency divider 38.
This constitutes a PLL, and a 108f _H signal synchronized with the reproduction horizontal synchronization signal is oscillated and output from the VCO 37. The output signal of this VCO37 is 1/2 frequency divider 3
9, supplied to the 1/3 frequency divider 40, 1/5 frequency divider 41 and 1/7 frequency divider 42, respectively, 54f _H , 36f _H , 108/5f _H , 10
The frequency is 8/7f _H. The outputs of the 1/2 frequency divider 39, 1/3 frequency divider 40, 1/5 frequency divider 41, and 1/7 frequency divider 42 are configured to be selectively switched and outputted by changeover switches 43 and 44. has been done. Here, the changeover switches 43 and 44 are both interlocked,
Further, switching control is performed based on a drum pulse that is synchronized with the rotation of the rotary head and reversed for each field, which is obtained by a well-known means in the home VTR.

Immediately after the tracking servo operation starts, the playback track and changeover switches 43 and 44, which will be explained below, are activated.
Although it is not always possible to obtain the following relationship between the switching connection position and the connection position, the tracking servo operation allows a steady state of the following relationship between the playback track and the connection position to be established in a short time.

Now, when playing track t ₅ (or t ₁ ) in the track pattern shown in FIG. 4A,
Of the terrains t ₄ and t ₆ on both sides adjacent to track t ₅ , a pilot signal with a repetition frequency of f _H /7 from track t ₄ and f _H /3 from track t ₆ is reproduced as crosstalk. Playback period switch 4
3 and 44 are connected to fixed terminals 43a and 44a,
The clock frequency of 108/7f _H of the 1/7 frequency divider 42 is supplied to the variable band filter 31, and the 1/3 frequency divider 4
The clock frequency of 36f _H of 0 is changed to variable band filter 3.
2, variable band filters 31, 32
The center frequencies of the passbands are controlled to f _H /7 and f _H /3. Therefore, the variable band filter 31 extracts the pilot signal to be reproduced as crosstalk from the track _t4 , which is one track before the track _t5 to be reproduced, and the variable band filter 32 extracts the pilot signal from the track one track after the track _t5 . A pilot signal reproduced as crosstalk is extracted from _t6 .

Further, when reproducing track _t2 shown in FIG. 4A, the changeover switches 43 and 44 are
b, 44b, and supplies the output clock frequency 54f _H of the 1/2 frequency divider 39 to the variable band filter 31 and the output clock frequency 108/5f _H of the 1/5 frequency divider 41 to the variable band filter 32. Therefore, the center frequency of the passband of the variable band filters 31 and 32 is
f _H /2 and f _H /5, and only the pilot signals reproduced as crosstalk from tracks t ₁ and t ₃ are frequency-selected and extracted.

Similarly, when reproducing track _t3 , changeover switches 43 and 44 are connected to fixed terminals 43c and 44c to set the center frequencies of the passbands of variable band filters 31 and 32 to f _H /3 and f _H /7, respectively. When reproducing _t4 , changeover switches 43 and 44 are connected to fixed terminals 43d and 44d to vary the center frequencies of the passbands of variable band filters 31 and 32 to f _H /5 and f _H /2. Thereafter, the same operation as above is repeated.

In this way, the changeover switches 43 and 44 operate in conjunction with each other in one field period when the rotary head 21 scans one track.
3b, 44b, 43c, 44c, 43d, 44
d, 43a, 44a, 43b, 44b, etc., the pilot signal is reproduced as crosstalk from an adjacent track formed one track before the track to be reproduced by the variable band filter 31. The variable band filter 32 also extracts a pilot signal reproduced as crosstalk from an adjacent track formed one track after the track to be reproduced.

The pilot signals extracted from the variable band filters 31 and 32 are supplied to attenuators 45 and 46 via detection circuits 33 and 34, respectively. In this embodiment, the waveform of the pilot signal is the third one for any track.
Since the signal n shown in Figure G has the same gate output waveform, if the recording level is constant and the track deviation is the same, there will be a pilot signal with a repetition frequency of f _H /2 and a pilot signal with a repetition frequency different from that, for example, with a repetition frequency of f _H /3. The magnitude of the reproduction energy differs from that of the repetition frequency pilot signal. Therefore, the attenuators 45 and 46 are provided so that when the rotary head scans the center of the track, the crosstalk from the adjacent tracks is the same.
The amount of attenuation is switched in conjunction with changeover switches 43 and 44 every track scanning period.

The crosstalk components of the pilot signals from the adjacent tracks extracted in this way are supplied to the differential amplifier 47, where they are converted into voltages corresponding to the respective level differences. The output voltage of the differential amplifier 47 is such that when the rotary head 21 is scanning the center of the track _t5 shown in FIG. 4A, the input signals of the variable band filters 31 and 32 are as shown in FIG. The pilot signal reproduced as crosstalk from track _t4 (all of 49, part of 52) and the pilot signal reproduced as crosstalk from track _t6 (part of 50, all of 51, part of 52) 51') are respectively reproduced at the same level and supplied to the differential amplifier 47, so the error component becomes zero.

On the other hand, when the rotary head 21 is simultaneously scanning the intermediate position between the track _t4 and the track _t5 to be reproduced shown in FIG. 4A, the input signals of the variable band filters 31 and 32 are As shown in C, the pilot signal is no longer reproduced as crosstalk from one of the tracks _t6 adjacent to the track _t5 to be reproduced, and is reproduced as crosstalk from the other adjacent track _t4 . Since only the pilot signal (all of 49a, part of 52a) is regenerated at a higher level than B in the figure and is supplied from the attenuator 45 to only one input terminal of the differential amplifier 47, the output of the differential amplifier 47 The voltage has a predetermined polarity and a level corresponding to the track deviation.

Contrary to the above, when the rotary head 21 is simultaneously scanning the intermediate position between the track _t6 shown in FIG. 4A and the track _t5 to be reproduced,
The input signals of the variable band filters 31 and ₃₂ become as _shown in FIG.
Part of 0b, All of 51b, Part of 52b, 51
b') is regenerated at a higher level than in the case of B in the same figure, and is transferred from the attenuator 46 to the differential amplifier 47.
While the pilot signal is supplied to the other input terminal of the differential amplifier 47, the pilot signal reproduced as crosstalk from the other adjacent track _t4 disappears, and the output of the attenuator 45 disappears, so the output voltage of the differential amplifier 47 becomes as shown in C of the figure. The polarity is opposite to that shown, and the level corresponds to the track deviation.

Therefore, the output voltage of the differential amplifier 47 is a track deviation detection signal whose polarity corresponds to the track deviation direction and which represents track deviation information corresponding to the amount of track deviation. By displacing the rotary head 21 in the width direction of the track in a direction and with an amount of displacement that makes the track deviation zero, track deviation caused by track bending or the like can be corrected. According to this embodiment, as is clear from the above description, even if there is a track deviation nearly twice the track pitch, it is possible to return to the correct track.

Note that the pilot signal is a relatively low frequency pilot signal that does not have a large azimuth loss, and is placed in the portion of the signal to be recorded that corresponds to the horizontal blanking period.
Multiple recording is performed at a repetition frequency that is an integer multiple of the horizontal scanning frequency _fH (in other words, at a period that is an integer multiple of the horizontal scanning period), and is not limited to the above embodiment. However, the repetition frequencies of the pilot signals on adjacent tracks are different, and the harmonics of the repetition frequency of the pilot signal reproduced from the track to be reproduced and the repetition frequency of the pilot signal from the adjacent track reproduced as crosstalk are different. In order to clearly distinguish between the two, the repetition frequencies of the pilot signals in adjacent tracks should not have a frequency relationship that is a natural number multiple of each other.

Furthermore, since the present invention obtains track deviation information by discriminating the repetition frequency of the pilot signal, the present invention can also be applied to home VTRs in which so-called H alignment is not recorded.
Furthermore, although the above embodiment describes the case where a magnetic tape is used as the recording medium, it can also be applied to a disc-shaped recording medium such as a magnetic sheet or a disk, in which case one of the spiral tracks is one part of the disc-shaped recording medium. Refers to something that is formed by rotation. Further, the signals to be recorded include not only color and black and white video signals, but also audio signals converted into PCM signals and converted into signals compliant with video signals.

As described above, the pilot signal recording and reproducing method according to the present invention applies a comparatively low frequency pilot signal to the portion of the signal to be recorded corresponding to the horizontal blanking period so that adjacent tracks all have different repetition frequencies. The multiplexed signal is multiplexed at a repetition frequency that is an integer fraction of the horizontal scanning frequency that is switched every track formation period, and this multiplexed signal is recorded to form a track, and during playback, the frequency selection means should be used to reproduce the signal in the playback signal. The above-mentioned pilot signals reproduced as crosstalk from the tracks on both sides adjacent to the track are extracted by selecting their repetition frequencies, and the track deviation information is expressed based on the relative level difference between the extracted reproduced pilot signals. Since it is configured to output a deviation detection signal, it can provide more accurate track deviation information even for large track deviations compared to the conventional method, which detects track deviations from fluctuations in the reproduced FM level while vibrating the rotary head in the width direction of the track. In addition, since the pilot signal is multiplexed during the horizontal blanking period, the band can be used effectively and the reproduced image quality is not degraded. The frequencies were selected to avoid a frequency relationship that is a natural number multiple of each other, so that the high frequency of the repetition frequency of the pilot signal reproduced from the track to be reproduced and the repetition frequency of the pilot signal from the adjacent track reproduced as crosstalk are different. Furthermore, by selecting a relatively low frequency component of the pilot signal from the reproduced signal in the frequency selection means, unnecessary high-frequency components can be removed. Since only the signal corresponding to the horizontal blanking period of the reproduced signal is gate-outputted, the S/N of the track deviation signal can be improved, and from the above, during reproduction, the rotating head is directed to the control signal in the direction perpendicular to its rotation plane. The present invention has many features such as being particularly suitable for track deviation correction in an azimuth recording type helical scan type magnetic recording/reproducing apparatus equipped with a head moving mechanism driven by displacement.

[Brief explanation of the drawing]

FIG. 1 is a block system diagram showing an embodiment of the recording system of the present invention, FIGS. 2A to 3J and 3A to G.
1 is a timing chart for explaining the operation of each part in FIG. 1, and FIGS. 4A and 4D are partially enlarged plan views showing an example of a track pattern formed by the recording system shown in FIG. 1, and reproduction at the time of each track deviation. FIG. 5 is a block system diagram showing an embodiment of the reproducing system according to the present invention. 1...Color video signal input terminal, 5, 39...
1/2 frequency divider, 6, 40...1/3 frequency divider, 7, 17,
41...1/5 frequency divider, 8,42...1/7 frequency divider,
9,43,44...changeover switch, 10,19,
29...Gate circuit, 12...1/16 frequency divider, 1
8, 30...Low pass filter, 31, 32...Variable band filter, 38...1/108 frequency divider, 47...
Differential amplifier, 48...Track deviation detection signal output terminal.

Claims (1)

[Scope of Claims] 1. A relatively low frequency pilot signal is applied to a portion of the signal to be recorded corresponding to the horizontal blanking period, and is switched every one track formation period so that adjacent tracks all have different repetition frequencies. The signals are multiplexed at a repetition frequency that is an integer fraction of the horizontal scanning frequency, and this multiplexed signal is recorded to form a track. During playback, the frequency selection means selects tracks from both sides of the playback signal adjacent to the track to be played back. The pilot signal reproduced as crosstalk is extracted by selecting the repetition frequency thereof, and a track deviation detection signal representing track deviation information is output based on the relative level difference between the extracted reproduced pilot signals. A pilot signal recording and reproducing method characterized by: 2. The pilot signal recording and reproducing method according to claim 1, wherein the repetition frequencies of the pilot signals, which are different for the adjacent tracks, are selected so as to avoid a frequency relationship that is a natural number multiple of each other. 3. The frequency selection means is configured to frequency-select relatively low frequency components of the pilot signal from the reproduced signal, and then extract the pilot signal reproduced as crosstalk by selecting their repetition frequency. A pilot signal recording and reproducing method according to claim 1 or 2. 4. The frequency selection means gate-outputs only the signal of the portion corresponding to the horizontal blanking period of the reproduced signal reproduced from the recording medium in which the horizontal synchronization signal recording positions of adjacent tracks are recorded in parallel with each other, and then outputs the signal as a crosstalk. 4. A pilot signal recording and reproducing method according to any one of claims 1 to 3, characterized in that the pilot signals to be reproduced are extracted by selecting their repetition frequencies. 5. The pilot signal is recorded on a magnetic tape by an azimuth recording type helical scan type magnetic recording/reproducing device equipped with a head moving mechanism in which a rotating head is displaced and driven by a control signal in a direction perpendicular to its rotating surface during reproduction. Claims 1 to 4 are characterized in that the track deviation is corrected by applying a control signal generated based on the track deviation detection signal to the head moving mechanism during reproduction.
The pilot signal recording and reproducing method described in any of the paragraphs.