JPS58100255A - Tape speed discriminating method of magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To discriminate a tape speed without using a control signal by providing a part which is not parallel to the widthwise direction of tracks, and recording pilot signals which are different in recording interval between adjacent tracks according to the tape speed. CONSTITUTION:As a tape speed decreases, widths TW3-TW5 narrow down successively; a video signal is recorded on tracks at position to be blank periods so that it is not aligned in the trackwidth direction, and low-frequency pilot signals P5-P3 are recorded lengthwise at different recording intervals of 1.5H, 1.0H, 0.5H, etc., according to the tape speed. Consequently, the tape speed of reproduction is discriminated without using any control signal. Further, those pilot signals are used for head height adjustment.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating magnetic recording/reproducing device (hereinafter referred to as VT).
This invention relates to a tape speed determination method for automatically switching magnetic tape running speeds (referred to as R), and specifically provides a new method for determining two or more tape speeds 1f' without using a control signal. .

In some VTRs, one deck has two or more tape running speeds If (for example, V) (such as a deck capable of recording for 2 hours and 6 hours, as seen in S-type VTRs). In such a VTR, the interval of the recording magnetic rhi trajectory according to the recording format in the 6-hour recording mode, that is, the track pitch width, is − compared to the track pitch width in the 2-hour mode.On the other hand, the F3 of the reproduced image
If the head and tape system are the same, /H is determined by sliding noise, equipment noise, track width, etc., and the wider the track width, the more advantageous it is in terms of S/H. Therefore, the reproduced image quality in the 6-hour mode is inferior to that in the 2-hour mode. Therefore, when high-quality playback images are required, recording and playback can be performed in 2-hour mode, and at other times, considering the tape cost, recording and playback can be performed in 6-hour mode. A VTR capable of recording and reproducing in 0T mode has been developed.

Switching between the 2-hour and 6-hour modes is performed by switching the tape running speed In as described above.

The tape speed is switched manually by the user during recording, depending on the recording purpose, and during playback, it is switched automatically using a control signal. The control signal is a 30H frequency-divided vertical synchronization signal included in the video signal.
This is the signal of z. When recording a signal of a certain number of waves ffr on a tape, the recording wavelength λ on the tape is the tape speed v,
Depends on. The relational expression at this time is 1), -fλ. Therefore, when a control signal of aoHz is recorded and reproduced at the same tape speed as at the time of recording, the frequency of the reproduced signal is 30 Hz. When recording at a tape speed of 2-hour mode and playing back at a time mode at a tape speed minus that tape speed, the frequency of the resulting playback signal is 10H.
There is 2'C. Conversely, when recording in 6-hour mode and playing back in 2-hour mode, the frequency of the playback signal obtained is 90 Hz.
It is. Therefore, by measuring the cycle of the reproduction control signal, C, which determines the tape speed during recording, can be used at 0T.

What has been described above is the principle of determining tape speed using control signals.

The original purpose of the control signal is to control the rotating video head and the tape drive system so that the rotating video head on-tracks and scans the recording track during playback. Tracking control methods using control signals are already well known. Taking a 2-head cedar helical scan type VTR as an example, I would like to explain this to you. During recording, a control signal synchronized with the rotation of the video head is recorded on the tape, and during playback, a signal (PG) that detects the rotational phase of the video head is recorded on the tape. By controlling the tape feeding speed using an error signal corresponding to the phase difference between the double signal and the reproduction control signal, the video head can perform reproduction scanning while on-tracking the recording track.

In a tracking control system using a control signal, although average position information of a recording track can be obtained, instantaneous position information, that is, position information corresponding to the curvature of the recording track cannot be obtained.

In recent years, high-density recording has been promoted in VTf'l, and the width of recording tracks tends to be narrower. Ideally, the recording track is recorded linearly on the magnetic tape, but in reality, it is recorded with a unique curvature for each deck. When performing compatible playback in which a magnetic tape recorded on one deck is played back on another deck, it is not possible to compensate for the inherent bending difference between the two decks using conventional control methods using control signals. The reproduced image quality deteriorates, and this problem becomes more serious as the track width becomes narrower.

To solve this problem, a method has been proposed in which the track curvature is corrected by obtaining a tracking error signal corresponding to the track curvature and displacing the rotary head in the rotation axis direction in accordance with the error signal.

Displacing the position of the rotating magnetic head in the height direction is
This is possible by mounting a magnetic head on an electromechanical transducer of a piezoelectric element and rotating it, and printing a control signal corresponding to the track bending onto the piezoelectric element. Already known tracking error detection methods include (1) a method using an auxiliary head; (2) A method in which the playback head is slightly moved in the width direction of the recording track during playback, and the direction of track deviation is detected from the output level fluctuation obtained at this time (search signal method); (3) Byron signal for detecting track deviation It can be broadly divided into methods for recording everything.

Using each of the methods (1) to (3) above, is a tracking error signal containing relatively high frequency components such as tracking and bending? Obtainable. Moreover, if the error signal is converted into an error signal composed of relatively low frequency components by passing it through a low-pass filter, the error signal obtained at this time will indicate average positional information of the recording track. Therefore, if the tape feeding speed is controlled using an error signal indicating average position information, a tracking control system that does not use a control signal can be constructed.

For example, to describe a tracking error detection method using a pilot signal, this method is
29727. Taking a two-head helical scan type VTft as an example, according to this method, a pilot signal is recorded every 2H, and the recording position of the pilot signal is recorded in the width direction of the tracks between each track within one frame. They are recorded so that they are lined up, but they are recorded so that they are not lined up one frame at a time. Further, the recording phase of the pyro throat signal is the same in the A track, and is inverted every 2H and recorded in the B track.

During playback, the pilot signal of the adjacent track recorded at the same position as the main scanning track in the track width direction is separated using a 2H delay circuit, and the pilot signal of the 1iJli track recorded at a different position from the main scanning track is separated. A tracking error signal can be obtained by separating the signals in time and comparing the levels of pilot signals reproduced from both adjacent tracks.

Conventional control does not use signals in this method of detecting a knocking error using a pilot signal. The same applies to the other two tracking error detection methods described above. Therefore, when a VTR that does not use a control signal has zero or more tape speeds during recording, the conventional tape speed determination method cannot be used.

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel tape speed determination method that does not use control signals.

Therefore, in the tape speed determination method according to the present invention, in addition to the signal for detecting track curvature, another signal is recorded, for example, within the vertical blanking period, and this signal is used to determine the tape speed. Also, when recording with a head on a piezoelectric element, the signal recorded during the vertical blanking period can also be used as a control signal used to adjust the relative height of the two heads. It is something.

Thereafter, a video head is mounted on the piezoelectric element, and a control signal used for adjusting the relative heights of the two heads is also used to determine the tape speed.

In order to perform control that can follow track bending, it is necessary to mount the head on a piezoelectric element. The piezoelectric element has a hysteresis characteristic that does not return to the original cedar shape even if the applied wake-up pressure is reduced to zero after being displaced by a voltage of 7111L. For this reason, V having two or more heads mounted on the piezoelectric element
In TR, it is necessary to adjust the height between each head during recording. Go to 2. Taking a Sodosugi helical scan type VTR as an example, we will explain how to adjust the head height during recording.

FIGS. 1 and 2 are diagrams for explaining the principle of head height adjustment during recording. In FIG. 1, 1 is a magnetic tape, which is transported in the direction of arrow 2. A1. A2.・
...and horse, B2. . . . indicates the recorded magnetic 1hi locus recorded at the throat to A and B, respectively. Each head scans in the direction shown by arrow 3.

The H@ position indicated by a solid line in the width direction of the recording track indicates the recording position of a horizontal synchronizing signal (H signal) included in the video signal. The magnetic "hibaturn" shown in Fig. 1 indicates a magnetic f#S locus in which H signals are arranged in a straight line in the width direction of the recording track, so-called H-alignment.
An example when the misalignment is 1.6H is shown (however, 1 and 4 indicate 1 horizontal scanning period) Q 1.6H section indicated by diagonal lines 'A1+RB1+... axis.../'i, This is the section in which a pilot signal used for adjusting the head height during aC recording and determining the tape speed is recorded, and is provided at a position where the blanking period of the video signal begins during playback.

The pilot signal to be recorded is, for example, a relatively low-frequency signal in the vicinity of 100 Hz, and is recorded superimposed on the FM-modulated luminance signal. 1, 4 shown in Fig. 1 is the recording position of the vertical synchronization signal. shows. Therefore, as is clear from the figure, by recording the pilot signal at a position delayed by a certain amount from the vertical synchronization signal, it is possible to obtain a magnetic trajectory in which the pilot signals are not lined up in the width direction of the recording track. be able to.

PBA4. after the recording period of 1,6H indicated by RA1+RBlr... The 1.6H section indicated by PBB1, . . . is a short-term playback section during recording. That is, when the head records on track A,'ff:, in the case of normal recording, pilot No. 1 for head height elongation and tape speed determination is recorded between RAl, and a signal is recorded during the period indicated by PBAl. Put the processing circuit into regeneration state. By doing so, it is possible to detect the height difference between the heads and the tape speed during recording, as will be described later.

FIG. 2 shows the trajectory of the recording magnetic field when the heights between the A and B heads are different. In head scanning, one head first records track A1, another head located at a position 180° different from it records track B1, and then A2. B2. ...... are recorded sequentially. While the head is recording and scanning track B1, the PBB1 section is put into the playback state, so at this time RA1 of track A1
Regenerate the pilot signal recorded in the section. The reproduced level of this much-anticipated pilot signal is higher than the level reproduced when the head heights of A and B are the same, that is, when the magnetic trajectory shown in FIG. 1 is formed. In FIG. 1, when the head nozzle scans track B1 on track, the head does not scan track A1.

However, since the recorded pilot signal is a relatively low-frequency signal, even if the head does not perform reproduction scanning on the recording track, the pilot signal recorded on the adjacent track can be reproduced due to leakage magnetic flux. It is possible to do so. In FIG. 2, after the head records and scans track B1, the head then scans track A.
However, in the short-term reproduction section PBA2 at this time, the pilot signal recorded in the RB1 section of the track B1 is reproduced. The reproduction level of the pilot signal reproduced at this time is A.

This is smaller than the level reproduced when the head height of B is the same. That is, in the recording pattern shown in FIG. 2, the pilot signal level reproduced by the short-term reproduction section of the B head is higher than that of the A head. If the head heights of A and H are opposite to those in Figure 2, that is, A track is B
When there is a difference in head height that overlaps the top of the head,
Conversely, the level of the pilot signal reproduced by the short-term reproduction section of the A head is higher than that of the B head. Therefore, the reproduction level of each pilot signal reproduced by the short-term reproduction section of each head A and B is compared, and if one of the heads changes the height of the other so that the reproduction levels are equal, then the height of the other head can be changed during recording. Head height adjustment is possible.

15 E! In a VTR that uses a device to move the front and back, it is essential to adjust the head height during recording, and when using the short-term playback method described above as a method for adjusting the head height, it is necessary to adjust the head height at the time of recording. As shown in FIG. 1, the magnetic locus must be such that the pyro-cito signals are not lined up between adjacent tracks.

To express it accurately, it is necessary to take a magnetic trajectory that has at least a portion where the signals do not line up between adjacent tracks. This is because if there is at least a portion where the pilot signals are not lined up, it is possible to separate and extract only the pilot signals recorded on the adjacent tracks in the portion. Although the period of 1.6H is equal to the amount of iH misalignment, for example, it is also possible to record the ironoto signal only in periods of o, 6H or less. This figure shows each magnetization trajectory when recording was performed at three different tape speeds when the number recording section was 05H.The pattern of the magnetization trajectory corresponds to the width of the tape on which the video signal is recorded.

It is known that the tape speed is determined by the diameter of the cylinder in which the head is built into one rotation, and if only the tape speed is changed as in this case, the recording track width Tw, H misalignment amount can be reduced as shown in Figures 3 to 5. As shown in the figure, this will change.For example, if the tape speed is slowed down, the track width will change to 1w3, 1w4,
The number becomes narrower as 1w5, and the number of H rows decreases. In the figure, HB is a video head, and the head width is HTW. Figure 3.

In FIGS. 4 and 6, the amount of H misalignment is 1. eiH.

Three types of recording patterns are shown: 1, o H, and ○, tsH. If the tape speeds iZ't3-vt4 and t5 are used during recording in FIGS. 3 to 6, the relationship between the tape speeds is Tw3=-1w4-3Tvv6 7 .

6, 6, and 7 in each figure indicate recording positions of vertical synchronization signals. P3 shown with diagonal lines. P4 and P6 are the above-mentioned pyro-cito signals, and both are recorded over a period of 0.5H at the same position apart from the vertical synchronization signal. When the tape speed has each of the above-mentioned tape speeds Ot3 to /'t5, the pilot signal is output during a period equal to or less than the H alignment amount (0.6H in this case) at the slowest tape speed /'t5. By recording, it is possible to obtain a magnetic trajectory in which the pilot signals are not aligned in the width direction of the track at any tape speed. In addition, as in this case, if the recording position of the pilot signal is recorded at the same position a certain distance away from the vertical synchronization signal by the same amount C recording length in each case, the pilot signal can be recorded. The circuit has the advantage that the same circuit can be used.

Next, the principle of determining the tape speed will be explained using FIGS. 3 to 6 and FIG.

The signal shown in FIG. 6(u) K is a vertical synchronizing signal during reproduction. The signal shown in (b) is a signal synchronized in position with the horizontal synchronization signal during reproduction, and is, for example, the output of an AFC circuit used in a video signal processing circuit. It is used here to indicate 1H length. (x), (y), and (z)
P3B1 is the reproduction output of the pilot signal obtained when the head reproduces and scans the track B1 on each line shown in FIGS. 3, 4, and 5 (P3B1).
．． P4B1. P6B1 is the pilot signal reproduced from track B1 on each line [hi trajectory.P3A1
~P6A1 and ``3A2~P6A2 are reproduction outputs of the pyro-cito signals recorded on track A1 and track A2.

The reproduction level of the pilot signals reproduced from the adjacent tracks A1 and A2 is influenced by the width of the recording trunk and the width of the reproduction scanning head. When actually forming a magnetic trajectory using the same head on a magnetic tape that is transported at two different tape speeds, the relationship between the recording track width and the head width is, for example, as shown in Figures 3 and 3. The result is as shown in Figure 4.

In the magnetic trajectory of the H misalignment dl and sH shown in FIG. In this case, the recording track width Tw4 is smaller than the head width HTW.The magnetic trajectory shown in FIG. 4 is recorded so that the left end of the head HB on the paper surface overlaps the immediately preceding recording track. According to the relationship between the recording trunk width and the head width shown in FIGS. 3 and 4, each adjacent track A1 and The level of the pilot signal reproduced from A2 is different between Fig. 3 and Fig. 4.However, since the relationship between the recording track and the head seat width is known in advance at the time of machining, as described later, If you adjust the level by amplifying or attenuating each pilot signal reproduced during the time period in which the pilot signal is reproduced, the signal will be reproduced from adjacent tracks regardless of the head width and recording track width. The level of the pilot signal can always be treated as constant (here, unless otherwise specified, it is reproduced from adjacent tracks) (The reproduction level of the pilot signal is independent of the recording track width and head width. It is indicated by a certain directness.

Note that when there are three types of tape speed during recording, for example, 4
By using two heads to obtain the magnetic r-hi trajectory shown in FIG. 3 and the other two heads to obtain the magnetic r-hi trajectory shown in FIGS. 4 and 6, ~@5
The magnetic r-hi locus shown in the figure can be obtained. Furthermore, at this time,
The relationship between each magnetic r/hi locus and the head width shown in FIG. 4 may be the same as described above when there are two types of tape speeds.

The recording start position of each pilot signal in Figures 3 to 6 is set 1H away from the vertical synchronization signal due to space limitations (although it is drawn at Figure 6 shows the reproduction output of the pilot signal recorded from a position 3H away from the falling edge of the vertical synchronization signal. At this time, the reproduction output of the pilot signal recorded on trunk B1 is always reproduced at a position delayed by a certain period of time from the reproduction output of the vertical synchronization signal.In contrast, each of the pilot signals recorded on tracks A1 and A2 As is clear from Figures 3 to 6, the reproduction output of the pilot signal is reproduced at a different time position from the vertical synchronization signal depending on the amount of H alignment deviation at the time of recording. The reproduced output of the pilot signal is separated in time, and the relative level of the pilot signal reproduced in each time period is compared to determine whether the pilot signal is reproduced in a predetermined vertical position. For example, the tape speed at the time of recording can be determined.For example, if the tape speed at the time of recording is the third
Taking as an example the two speeds υ, 3 and t4 explained in Fig. 6 and Fig. 4, the output form of the pilot signal reproduced at this time is as shown in Fig. 6 (X) and (y). If the pilot signal is reproduced at time t1 shown in the figure, the tape speed e at the time of recording is Z't3, and if it is not reproduced, the tape speed e is 0 or tl, which can be determined to be vt4. Compare the levels of the reproduced pilot signal at time t1 and t2, and if the reproduction level of the pilot signal reproduced at time tl is greater than that reproduced at time t2, the tape speed at the time of recording is Ot3. If there is a reverse relationship between the playback 2 levels, it can be determined that the tape speed at the time of recording is Z't4.This determination can be made regardless of the tape speed at the time of playback.
The rotation speed of the rotating head is sufficiently fast compared to the tape travel speed.
This is because the angular change of the track with respect to the tape running direction hardly changes even if the tape speed changes.

Even when the tape speed has the three speeds shown in Figures 3 to 5, by sequentially comparing the playback levels of the pyro/cito signals at times t1 to t3, the tape speed at the time of recording can be determined. can be determined. The details of this method will be described later.

Next, a specific circuit example implementing the tape speed determination method according to the present invention will be described.

FIG. 7 shows an example of a pilot signal recording circuit, and FIG. 8 shows waveforms at various parts in FIG. In FIG. 7, one vertical synchronization word (a) extracted from the video signal to be recorded is inputted from the terminal 8. Tun stable transmitter (MM) 9 a
A gate pulse generation circuit 1oi'j consisting of , and 9b
As shown in FIGS. 8(b) and (C), a gate pulse (C) having one pulse of MM9b is created at position M after a certain time delay determined by the pulse width of MM9a from the vertical signal. do. In this example, a 0.6H width gate pulse is generated after 3H of the vertical synchronization signal regardless of the tape speed. The circuit 11 is an oscillation circuit, and has a frequency of approximately 126KH2 (-8,·fH, fH:
Horizontal frequency) A continuous sine wave pilot signal is output. The switch 71 is an electronic switch that becomes conductive during the period when the gate pulse (C) is at the level, and changes from a continuous pilot signal to an intermittent pilot signal (d) f.
! :create. The pilot signal (d) is superimposed on a video signal including an FM-modulated luminance signal and a low-frequency-converted color signal input from the terminal 12 in an adder circuit 70, and is amplified in a recording amplification circuit 13. These mixed signals are supplied to the video RAD 14 via a recording/reproducing switch 72 connected to the recording side, and are recorded as a magnetization locus on the magnetic tape. By using the simple circuit configuration shown in FIG. 7 for the recording circuit, it is possible to obtain each recording magnetic locus shown in FIGS. 3 to 5 depending on the tape speed.

Next, an example of a reproducing circuit will be explained.

For convenience of explanation, a method for determining the tape speed when there are two types of tape speeds during recording will be first described. FIG. 9 shows an example of a specific circuit for determining the tape speeds Ot3 and υ, 4 explained in FIGS. 3 and 4 when there are two types of tape speeds during recording. Figure 10 shows that the tape speed during recording is θt3,
That is, they are the waveforms of each part in FIG. 9 obtained when reproducing the recorded magnetic rhi trajectory shown in FIG. These are the waveforms of each part in the figure. In FIG. 9, head 16 is a playback video head. The signal reproduced by the head 15 is input to the head amplifier 16 via the reproduction side terminal of the recording/reproduction changeover switch 72, and is amplified. The amplified signal is input to a normal reproduction signal processing circuit from the terminal 17,
While being restored as a reproduced image signal, only the pilot signal of the 1 degree frequency is extracted by passing it through the low-pass filter 18. The reproduction pilot word No. 5 obtained at this time differs depending on the recorded magnetic rhi trajectory as explained above, and when the tape speed during recording is υt3, the reproduction pilot word No. 5 shown in Fig. 1 (q
) When θ is 4, the signal shown in FIG. 11(q)' is obtained.

A vertical synchronization signal (q) extracted from the reproduced signal in the reproduced signal processing circuit is inputted from the terminal 19. Circuits 2o and 21 are gate pulse generation circuits that generate gate pulses (h) and (1), and each has a circuit configuration as shown in FIG. 7 1o, for example. Here, the MM pulse It]'fr corresponding to 98 is different, Fig. 6 t1
The configuration is such that the gate pulses are generated at different times such as 1 and 12. Sinchers 3 and 74 are electronic switches in which gate pulses (h) and (i) are brought into conduction between the ribs of the level. 22 is a detection circuit that detects the envelope of the positive polarity signal of the regenerated pilot signal ((1) or (q)'; resistor R9 electronic switch 73, 74
, capacitor C11C2 constitute a low pass filter and a sample hold circuit. When the switch 73 is in a conductive state, the detected pilot signal is divided by the resistor R and the capacitor C1, and the capacitor C1 is charged or discharged with an electric charge depending on the reproduction level. When switch 73 is non-conductive, the charge stored in capacitor C1 is held.

The same can be said of switch 74 and capacitor C2. The voltages held by the capacitors C1 and C2 are input to amplifier circuits 23 and 24. Amplification circuit 23
and 24 are H held in each capacitor C1, C2.
In addition to amplifying E, the level of each hold [ is also adjusted. In other words, when reproducing each line trajectory recorded at different tape speeds, the playback level of the pilot signal obtained from the adjacent track when the head ontrunks the main track and scans for playback is related to the tape speed at the time of recording. The levels are adjusted so that they are equal.

The outputs (J), (k) or (
i)', (k)' are each gate pulse (h), (l
This is a voltage that corresponds to the reproduction level of the pilot signal that is reproduced during the period when is at a high level. Therefore, the tape speed is /'
When reproducing the magnetic trajectory recorded at t3, the 10th
As shown in the figure, at 27, the voltage of the signal (]) becomes larger than the voltage of the signal (kl), and when the magnetic rhi trajectory is reproduced when the tape speed during recording is Z't4, @Figure 11 (i) The relationship is reversed as shown in ', (k)'.The circuit 25 is a voltage comparison circuit, and its output is a high level when the tape speed during recording is VT3, and a low level when the tape speed is Ot4. 26.The voltage obtained at the terminal 26 is supplied to a capstan control system (not shown) that controls the tape feed speed.When there are two types of tape speeds during recording, the tape speed at the start of playback is If the tape is played back at one of the tape speeds at which it was recorded, and the tape feed speed is switched according to the high or low level output obtained from the terminal 26, playback can be performed at the same tape speed as at the time of recording. That is, automatic switching of the tape speed during playback can be realized.

Next, a method for determining the tape speed when there are three types of tape speeds during recording will be described. Figure 12 shows the LFT failure of the tape speed discrimination circuit that implemented this, and Figure 13 shows the failure of the tape speed discrimination circuit that implemented it.
The waveforms of each part in Figure 2 are shown. A reproduced video signal amplified by the head amplifier circuit is inputted from the terminal 27. Although the configuration before the head amplifier circuit is not shown in Figure 12,
The same configuration as that explained in FIG. 9 is adopted. Circuit 28 is a low pass filter that extracts only the pilot signal.

The regenerated pilot signals are as shown in Fig. 13 (e), (n),
One of the signals shown in (0) is output. The signal varies depending on the tape speed at the time of recording, and here @Figure 3,
According to the magnetic trajectory shown in Figs. 4 and 6, (rrN
, (n) (0) corresponds to the numbers. circuit 29
is a detection circuit, which extracts only the positive signal of the regenerated pilot signal by envelope detection. Circuits 30, 31, and 32 are sample and hold circuits, and the resistors R and 32 shown in FIG.
Switch 73. The configuration is similar to that shown for capacitor C1. The sample pulse (gate pulse) is a pulse having the timing shown in FIG. Similarly, it is created by two MMs. 33, 34, and 35 are the level adjustment amplifier circuits already explained in FIG. The circuit 936 is a voltage comparison circuit, which compares the respective output voltages of the amplifier circuits 33 and 34. Therefore, the output of the circuit 36 is as shown in FIG. The output of the circuit 36 is
- When the level is high, the output of the amplifier 33 is passed, and when the level is low, the output of the amplifier 34 is passed. A voltage comparison circuit 37 compares the signal passed through the switch 76 with the level of the amplifier circuit 360. The output of the voltage comparison circuit 37 becomes a low level when the reproduced pilot signal is in the form shown in FIG. 13 (0), and becomes a high level when the pilot signals shown in (e) and (n) are reproduced.

This is because when the regenerated pilot signal is (0), the amplification width is 4.
The output of the 36 has a voltage according to the reproduction level of the pilot signal, but the signal obtained from the Swiss 6 at this time has a noise level voltage value that is equal to zero voltage, regardless of which signal passes through it. And, if the pilot signal to be reproduced is (e) or cedar), the output of the amplifier 35 is at the noise level of 1, 1, 0, This is to output the higher level signal of the selected one.

Table 1 shows the relationship between the tape speed during recording and the voltage values of the outputs of voltage comparison circuits 36 and 37 appearing at terminals 38 and 39. In Table 1, the output of the voltage comparison circuit 37 is at a low level (
This shows that the output of the amplifier 36 can be high level H or low level when the amplifier 33 is
．． This is because when the Ryokawa force of 34 is a noise level signal, it is not known which one the output of the voltage comparator circuit 36 will be.

According to Table 1, it is possible to determine the tape speed from the output modes of the two voltage comparison circuits 36 and 37 even when there are three types of tape speeds during recording.

Generally, even when there are n types of tape speeds during recording, the 12th
By adding the sample-hold circuit and voltage comparison circuit shown in the figure, it is possible to determine the speed using the same concept.

In this detailed explanation, we described a method for determining the tape speed during recording by relatively comparing the playback level of the pilot signal between each gate rib. The tape speed at the time of recording can also be determined by comparing the level of the reproduction pilot signal obtained in one of the gate periods with the reference voltage.

In the detailed description of the present invention, an example was used in which the pilot signals are not aligned between adjacent tracks in the recording patterns shown in FIGS. 3 to 6 described above. However, even if a part of the pilot signal is lined up between adjacent tracks, if there is a part where they are not lined up, it is possible to separate and reproduce only the pilot signal on the adjacent track in that part. As already mentioned in the section explaining adjustment.

Also, in the explanations so far, we have mainly explained VTRs in which the head is movable by a piezoelectric element, but what about the head? The present invention is also applicable to VTRs that are not movable. A VTR that does not have a movable head does not require a pilot signal for head height adjustment. However, even in this case, if you want to create a tracking control system that does not use control signals, you should record a pilot signal for tape speed determination along with a pilot signal that is converted into a control signal (track bending can also be detected). , it is possible to determine the tape speed.

Furthermore, the recording position of the pilot signal for determining the tape speed recorded in a VTR that does not have a movable head can be changed from the head to the recording position. If the recording position is made equal to the recording position of the pilot signal for adjusting the head height during recording, which is defined by the movable VTf method, compatibility on the tape pattern can be maintained.For tracking control. In the case of the above methods (1) and (2) in which the pilot signal is not recorded in the step 3, similar speed discrimination becomes possible by recording the pilot signal as described above exclusively for detecting the speed.

As is clear from the above description, according to the present invention, it is possible to determine the entire tape speed during recording by using pilot signals recorded so as not to be lined up with each other in the width direction of the recording track. Automatic determination of the tape speed is possible even when the tape speed is not recorded.

Furthermore, the pyro-y) signal for determining the tape speed has the advantage that it can also be used as a pilot signal for adjusting the head height during recording in a VTR whose head can be displaced in the height direction.

In addition, when there are several tape speeds, if the recording length is equal to or within the amount of H of the magnetic locus recorded at the slowest tape speed, , the same circuit can be used for recording the pyro-node signal at various tape speeds.

[Brief explanation of drawings]

4 FIGS. 1, 3, 4, and 5 are diagrams showing examples of recording patterns when using the tape speed determination method of the magnetic recording/reproducing apparatus according to the present invention, and FIG. 2 is a diagram showing examples of recording patterns according to the present invention. FIG. 6 is a recording pattern diagram for explaining the principle of head positioning during recording in this embodiment, FIG. 6 is a reproduction waveform diagram for explaining the principle of tape speed determination in the same embodiment, and FIG. 7 is a pilot diagram in the same embodiment. A block diagram showing a signal recording circuit,
Fig. 8 is a waveform diagram of the main part of Fig. 7, and Fig. 9 is a block diagram showing a reproducing circuit in the same embodiment for determining the tape speed.
Figures 10i and 11 are main part waveform diagrams of Figure 9,
The figure is a block diagram showing a reproducing circuit according to an embodiment of the present invention, and FIG. 13 is a waveform diagram of the main part in FIG. 12. 1 fist...-magnetic tape, A1. B, ,A2. B2
...Nakazori 1hi locus, RAl, RBl, RA2, fLB2°
@@@116・B3・B4・B6・・・Pilot signal recording section, 1o・・・■・Gate pulse generation circuit,
11...Oscillation circuit, 14.15...■Video head, 18...L-low pass filter, 20.2
1-... Gate pulse generation circuit, 2236... Detection circuit, 25... Voltage comparison circuit, 7°・Salary... Addition circuit, 71, 73, 74...・・・
・Nemiko switch. Name of agent Patent attorney Toshi Nakao 1 person Special opening H58-100255 (10) Fig. 1 1be 360-@4 Fig. 5 Fig. 5 Fig. 10---Ov Fig. 12 Fig. 11 (2) □----□ o v

Claims (6)

[Claims] (1) A magnetic tape transported at two or more different running speeds is wound around a cylinder equipped with a rotating head for recording and reproducing information signals, and information signals are recorded as discontinuous recording tracks on the magnetic tape. At the same time, the rotating head causes the recording track to have at least a portion that is not aligned in the IJ force direction at any of the two or more tape running speeds, and the recording track in the longitudinal direction at each of the two or more tape running speeds. In this method, pilot signals are recorded so that the recording intervals are different between adjacent tracks, and the tape running speed at the time of recording is determined by determining the playback level at a predetermined position of the reproduced pilot signal during playback. A method for determining the tape speed of a magnetic recording/reproducing device. (2) The tape running speed variation during recording is determined by relatively comparing the playback levels at different times corresponding to two or more tape running speeds of the reproduced pilot signal. A tape speed determination method for a magnetic recording/reproducing device according to scope 1. (3) The magnetic recording and reproducing apparatus according to claim 1, wherein the tape running speed at the time of recording is determined by comparing the reproduction level of the reproduced pilot signal at a predetermined position with a reference value. How to determine tape speed. (4) The information signal is a video signal including a synchronization signal, a gate signal is formed at a predetermined interval from a vertical synchronization signal separated from the reproduction signal, the pilot signal reproduced by the gate signal is held, and the pilot signal reproduced by the gate signal is held. A tape speed determination method for a magnetic recording and reproducing apparatus according to claim 1, 2, or 3, characterized in that the tape running speed during recording is determined by determining the held signal level. . (5) Is the recording length of the pilot signal at the valleys of two or more different tape running speeds equal to the H alignment deviation amount of the magnetization locus formed when recording at the slowest tape running speed among these running speeds? 5. A method for determining a tape speed of a magnetic recording/reproducing apparatus according to claim 4, wherein the tape speed is set to a value equal to or lower than that. (6) It is characterized by comprising two rotary heads that can be displaced in the width direction of the recording track, and using a signal for detecting a height deviation to adjust the relative heights of the two heads as a pilot signal. A tape speed 1+1 method of a magnetic recording/reproducing apparatus according to claims 1 to 5.