JPS6069814A - Rotary head-type reproducing device - Google Patents

Abstract

PURPOSE:To attain an analog and good driving signal having no stepwise change to trace a recording track very faithfully by utilizing the second signal having a voltage, which corresponds to the frequency of the first signal related to the transporting operation of a recording medium, to generate a driving signal of a moving means of a rotary head. CONSTITUTION:A capacitor C2 is charged by the current obtained from a constant current source 46 when a head switching signal (a) is in a low level, and the change of the potential at a point (c) is in a form of triangular waves having a certain gradient. When the head switching signal is in the high level, the electric charge charged in the capacitor C2 is discharged through a resistance R4, and a waveform (c) is obtained. At this time, it is sufficient if the current of the constant current source 46 is set to such value that the potential difference between both ends of the capacitor C2 is a potential difference required for driving a bimorph for an extent corresponding to one track pitch in 1/60sec when the capacitor C2 is charged. The potential at the point (c) is subtracted from that at a point (b) by a subtractor 43 to obtain a bimorph driving pattern signal which has a gradient shown in a figure (d).

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a rotary head type reproducing device, and more particularly, to a rotary head type reproducing device, in which recording tracks formed at a predetermined array pitch on a recording medium transported by a transporting means are moved by a shifting means. The present invention relates to a rotary head type reproducing device that reproduces a recorded signal by tracing it with a rotary head that is displaced in a direction perpendicular to the rotating surface, and more specifically includes high-speed reproduction and low-speed reproduction.

This invention relates to control of the shifting means when performing reproduction at a speed different from the recording speed, such as in reverse reproduction.

<Description of Prior Art> Rotary head type playback devices such as VTRs are used for high-speed playback, low-speed playback (including static playback), reverse playback, etc.

Prevents noise bars from occurring when playing back at an arbitrary speed different from the recording speed (so-called special playback).

In order to enable stable and clear image reproduction, it is necessary to ensure that the reproduction head accurately traces one recording track in each scan field.

As one means to realize such a function.

Conventionally, a pattern signal generator is provided which generates a pattern signal corresponding to the distance from the scanning locus of the playback head to the recording track on the tape at a given tape running speed. A known method is to control a displacement means such as an electro-mechanical conversion element (for example, a bimorph element) for displacing the reproducing head in a direction perpendicular to its rotation plane.

FIG. 1 is a diagram showing a conventional VTR of this type,
In particular, it is a diagram showing a schematic configuration of essential parts related to the present invention. In FIG. 1, 1 is a magnetic tape as a recording medium, and 2A and 2B are magnetic heads for reproduction.

They are provided so as to have the same azimuth angle and face each other by 180 degrees, and are respectively attached to the free ends of electro-mechanical transducers 3A and 3B, such as bimorph elements, serving as displacement means. The converting elements 3A and 3B are attached to a rotating member 4 at their tail ends, and the rotating member 4 is rotated by a head rotating motor 5 as shown by the arrow in the figure. Sho 1
Although not shown in the figure, as is well known, two heads and two
B is rotated while protruding from a slit between a pair of tape guide drums, and the tape 1 is wound diagonally around the pair of drums over a range of 180 degrees or more. 6 is a rotational phase detector for detecting the rotational phase of the two heads and 2B.2 The signal from the detector 6 is a head switching signal (hereinafter referred to as H8W signal)
It is used as It is controlled through a head motor drive circuit 8. Reference numeral 9 indicates a control signal (hereinafter referred to as CT) recorded at intervals of one frame in the longitudinal direction at the bottom of the tape.
a fixed head (hereinafter referred to as a CTL head) for reproducing a control signal (L signal), a capstan 10 constituting a transport means for transporting the tape L in the longitudinal direction in cooperation with a pinch roller (not shown); 11 is a cabstan motor for rotating the capstan 10; 12 is a frequency signal corresponding to the rotation of the capstan 10 (hereinafter referred to as
a frequency signal generator that generates a capstan FG signal);
Reference numeral 13 drives the carburetor tongue motor 11 through the carburetor tongue motor drive circuit 14 so as to rotate the gear shifter A 10 in a predetermined phase and at a predetermined rotational speed based on the CTL signal from the CTL head 9 and the capstan FG signal from the frequency signal generator 12. This is the carburetor tongue motor control circuit. 1
5 is for reproduction at any speed (including stationary and reverse rotation) based on the H8W signal from the rotation phase detector 6, the CT L signal from the CT L head 9, and the capstan FG signal from the frequency signal generator 12. , a further electro-mechanical transducer 3 which allows the heads 2 and 2B to each trace one recording track on the tape 1 in each scanning field.
A pattern signal generation circuit 16 generates pattern signals for A and 3B, and a conversion element drive circuit 16 drives the conversion elements 3A and 3Bf based on the pattern signal from the pattern signal generation circuit 15.

FIG. 2 shows an example of the configuration of the pattern signal generation circuit 15. In the figure, the input terminals 17, 18 and 19 respectively receive the capstan FG signal from the frequency signal generator 12, the CTL signal from the C'J'L head 9, and the H8W signal from the rotational phase detector 6. is input. 20 is terminal 17
A binary counter 21 is configured to count the capstan FG signal inputted to the terminal 19 and reset by the CTL signal inputted to the terminal I8.
a timing signal generation circuit that generates a timing signal synchronized with the H8W signal based on the H8W signal input to the H8W signal;
22 is a presettable binary counter that receives the output of the counter 20 as preset data PD by the timing signal from the timing signal generation circuit 2 and counts the capstan FG signal input to the terminal 17; A D/A converter performs D/A conversion on the output of the presettable counter 22 and outputs a first pattern signal, and 25 is an adder.

26 is an output terminal for outputting a conversion element control pattern signal (drive signal) which is the output of the adder 25; 27 is an oscillator that generates a clock pulse of a predetermined frequency; 28;
29 is a counter that counts clock pulses generated by the oscillator 27 and is reset by a timing signal from the timing signal generation circuit 21; and 29 is a D/A converter that converts the output of the counter 28 into a D/A converter. That is, the output of the counter 22 is related to the transport speed of the recording medium.

The output of the counter 28 is independent of the transport speed of the recording medium, and the D/A converter 29 outputs a fixed pattern signal (second pattern signal) for still reproduction.

Next, regarding the operation of the VTR configured as described above during special playback,
In particular, the operation of the pattern signal generation circuit shown in FIG. 2 will be explained with reference to FIGS. 3 and 4.
Figures (α) to (g) are timing charts showing ideal waveforms of each part. In addition, the counter 22 (or D/A
The output of the converter 23) and the output of the adder 25 are respectively shown. However, the timing chart shown in FIG. 3 shows an ideal output assuming that the frequency of the capstan FG signal is extremely high. Figures 4 (A) and (B) show the relationship between the center locus of the scanning of the heads 2A and 2B with respect to the center locus of the recording track on the tape 1 during still playback and 15x speed playback, respectively. As the heads 2 and 2B rotate by the head motor 5, the rotational phase detector 6 outputs the H8W signal as shown in FIG. 3(a), and in response, the pattern signal shown in FIG. The timing signal generation circuit 21 in the circuit 15 outputs a timing signal synchronized with each rise and fall of the HSW signal, as shown in FIG. 3(b). Then, based on this timing signal, the D/A converter 24 sends signals from the heads 2A and 2B'eO to 11 track pitches (hereinafter referred to as TP) within one field of scanning as shown in FIG. 3(C)K. A stay pattern signal is output for continuous transition up to minutes.

Here, the so-called field stay is performed in which the field signals of one recording track recorded by the recording head having the same azimuth angle as the two reproduction heads and 2B are alternately reproduced by the two reproduction heads and 2B. When attempting to perform playback, the relationship between the center trajectory of the scanning of the two heads and 2B with respect to the recording track on tape 1 at this time is the fourth
The result is as shown in Figure (A). That is, in FIG. 4(A), the solid line indicates the center locus of the recording track of the field signal recorded by the recording head having the same azimuth angle as that of the heads 2 and 2B, and the broken line indicates the center locus of the recording track of the field signal recorded by the recording head having the same azimuth angle as that of the heads 2 and 2B. indicates the center trajectory of the recording track of the field signal recorded by the recording heads with different azimuth angles, the white arrow indicates the center trajectory of the scanning of the two heads and 2B, and CT
Lil-1: This shows the recording trajectory of the CTL signal (
Note that this also applies to FIG. 4(B).) As shown in Figure 2, the center locus of scanning of the two heads and 2B (hereinafter referred to as head trajectory) C is the center trajectory of the track to be reproduced (hereinafter referred to as head trajectory). , track trajectory) a, this is a line segment that diagonally connects the starting end of the track trajectory a and the terminal end of the track trajectory of the track adjacent to the left. Therefore.

To correct this and align the head locus C with the track locus a, the two heads and 2B are set so that the running direction of the tape I during recording is +2 and the opposite direction is -.

It can be seen that it is sufficient to continuously shift from 0 to -ITP within one field of scanning.

Therefore, in the D/A converter 29 shown in FIG. 2, if the output of the 2 counter 28 is converted into a stay pattern signal as shown in FIG. It can be seen that the required transition can be satisfied.

On the other hand, the capstan FG signal output from the AJ wave number signal generator 12 as the capstan 10 is rotated by the carburetor stan motor 11 is applied to the counters 20 and 22 in the pattern signal generation circuit 15 shown in FIG. These counters 2o and 22 are given by this capstan F
The G signal will be counted, but here,
Since the counter 2° is reset every frame by the C'TL signal from the CTL head 9, the count value of the counter output + 2) rack pitch is the upper limit, and the CTL signal is used during 1.5x playback. is shown in Figure 3 (
d), the result will be as shown in Figure 3(e).

25, the presettable counter 22 counts the capstan PG signal while being preset to the output of the counter 20 at that time by the timing signal (FIG. 3(b)) from the timing signal generation circuit 21. , its count output (or D/A converter 23
(output) becomes as shown in FIG. 3(f) during 1.5x speed playback. Therefore, the adder 25 adds the output of the D/A converter 23 and the output of the still pattern generator 24 at this time, and the result is as shown in FIG. 3(g) when playing at 1.5x speed.
A pattern signal as shown in is output.

Here, for 155x playback, the head trajectories of the two heads and 2B with respect to the track locus on tape 1 are as shown in Figure 4 (B
) as shown below. That is, in Figure 1.

A1. N, N,... is the head trajectory of head 2A.

B8. B2. B5. ...... is the head trajectory of head 2B.

Also, r aI+ 82+ aS+... is head 2
This shows the track locus of the field track recorded by the method with the same azimuth angle as A and 2B. It is necessary to continuously give a transition from 0 to +〇, 5 T i' division within the scan, and in order to match the head trajectory B to the track trajectory a in the second field, a second change is made to the head 2B. +1 within field scan
．． It is necessary to continuously apply a change from 5 TP to +2 TP, and in order to match the henodic trajectory A2 to the next track trajectory a2 in the 3rd field, the shift from +ITP to 2 TP must be applied to the 2 heads within the scanning of the 3rd field. +1.5
'I' It is necessary to continuously give a change up to P,
In the fourth field, in order to match the head trajectory B2 with the next track trajectory a, it is necessary to continuously give the head 2B a shift from +0.5 TP to +1 'L' P within the scan of the 4th field. In the following, the above steps will be repeated every 4 fields.
It can be seen that the pattern signal shown in ) satisfies this requirement.

The above has been explained using 1.5x playback as an example, but the pattern signal for controlling the two heads and 2B commensurate with the playback speed not only at 1.5x speed but also at any playback speed is the above pattern. It is obtained from the signal generation circuit 15.

The pattern signal obtained from the pattern signal generation circuit 15 in this manner is applied to the conversion element drive circuit 16, which drives the heads 2A and 2B based on the pattern signal.
The electro-mechanical transducers 3A and 3B are driven to bring the signal on track with respect to the track to be reproduced.

Based on the above-mentioned principle, in the conventional device.

A noise-free reproduced video signal was obtained at any reproduction speed by obtaining a pattern signal for driving a shifting means such as an electro-mechanical conversion element.

However, the outputs of the counters 29, 20, and 22 shown in FIGS. 3(C), (e), and (f) are not linear as shown. If the number of CAGstan FG signals generated per unit time is infinite and the oscillation frequency of the oscillator 27 is extremely large, a waveform approximately like that shown in Fig. 3 will be obtained. The number of pulses of the capsun FG signal generated during the transfer (during the transfer of
It ends up being just a few. Therefore, the outputs of the counters 20 and 22 include small stepwise changes. Especially in modes where the transport speed of the recording medium is low, such as during slow motion playback, capstan FG occurs per unit time.
The number of signals becomes extremely small.

Sometimes only 2-3 degrees are counted per rotation of the rotating head.

FIG. 5 is a timing chart showing actual waveforms of each part in FIGS. 2(a,) to (g). This figure is also a timing chart for 1.5x speed playback, and shows the entire CT of the magnetic tape.
4 capstans F when moved by the interval of L signal
The configuration is such that a G pulse can be obtained. That is, the frequency of the capstan FG signal supplied to the input terminal 17 is 180 Hz. Further, for simplicity, it is assumed that the oscillation frequency of the oscillator 27 is 180 Hz, and that the capstan FG signal and the output of the oscillator 27 are synchronized in phase.

As is clear from FIG. 5, the actual driving pattern signal is accompanied by step-like changes. Generally, the conversion element drive circuit 16
A low-pass filter (LPF) that passes the output signal of the adder 25 is included, and a certain degree of stepwise change is compensated for. However, as mentioned above, when the number of capstan PG signals generated per unit time becomes extremely small, a stepwise change remains in the driving pattern signal of the shifting means, and the change occurs on the recording track. It becomes impossible to trace accurately. A stepwise change in size causes a resonance (ringing) phenomenon in the transition means such as an electro-mechanical transducer, which hinders good tracing. In order to completely prevent this, it is possible to set the cutoff frequency of the LPF in the conversion element drive circuit 16 extremely low, but in this case, the shape of the drive pattern signal should be ideal as shown in Figure 3. This is undesirable because not only will the phase be distorted, but also a large phase delay will occur with respect to the original phase.

<Object of the Invention> The present invention has been made in view of the above-mentioned drawbacks, and it is possible to change the structure in an analog manner and achieve almost ideal output without increasing the precision of the structure of the transfer means such as a capstan. It is an object of the present invention to provide a rotary head type reproducing device which is capable of faithfully tracing the entire recorded track by supplying a close drive signal to a displacement means for displacing the head in a direction perpendicular to its rotating surface. The purpose is

<Description of Embodiments> Hereinafter, embodiments of the present invention based on the above-mentioned VTRKTR will be described in detail.

FIG. 6 is a diagram showing the main part configuration of a VTR as an embodiment of the present invention. The portion indicated by 30 in FIG. 6 is the pattern signal generating circuit 15 shown in FIG. and transition element drive circuit 16
fulfill the role of The configuration of other parts of the VTR is shown in Figure 1.
It is similar to In FIG. 6, 31 is a terminal to which the capstan FG signal from the capstan FG signal generator 12 shown in FIG. 1 is supplied, and 32 is a terminal to which the H8W signal from the rotational phase detector 6 shown in FIG. 1 is supplied. terminal, 33 is terminal 3
The capstan FG input to 1 is an FV converter that performs F■ conversion (frequency-voltage conversion), 34 is an inverter, and 35 and 36 are converted to bimorphs 3A and 3B according to the output of the FV converter 33, respectively. A pattern forming circuit forms a driving pattern signal to be supplied, 37 and 38 are amplifiers, and 39 and 40 are output terminals to the bimorphs 3A and 3B, respectively.

FIG. 7 is a circuit diagram showing a specific example of the pattern forming circuit 35 in FIG. 6. In FIG. 7, 41 is a terminal to which the output signal of the FV converter 33 is supplied.

42 is a terminal to which the above-mentioned HSW signal is supplied; 43
44 is a terminal to which a power supply voltage (Vcc) is supplied, 45 is an output terminal to the amplifier 37, and 46 is a constant current source. Also, ch, C4 and q are PNP) transistors,
Q2. Qa is each N P N transistor, ■ circle ~ T
(, are resistors, respectively, and C, , C2 are capacitors, respectively.) Figure 8 is a timing chart showing the waveforms of each part in Figures 7 (α) to (d), and the operation will be explained below. The output of the FV converter 33 is connected to the base of the transistor q, and a current approximately equal to I=V group flows through the resistor.(However, the output voltage of the FV converter 33 is assumed to be ■in.) The current mirror circuit consisting of transistors Q and Q2 causes an equal current I to flow from the collector of transistor q, thereby charging capacitor C1.If the HSW signal (a) is now at a low level, the capacitor/ The potential difference between both ends of the capstan C3 increases due to charging.Let the frequency of the capstan FG signal be f.

If the output voltage of the FV converter 33 is Vin = kf.

I = Vin/1%, and V at point (b) at about 41L
out (l-1: VOLI t.In other words, the slope of the part indicated by P in Fig. 8 is -5f, and the capstan FG
A triangular wave having a slope proportional to the frequency of the signal will be obtained. Therefore, during normal playback, t=π(see
)9 o'clock.

The cI, i, and tcO values are determined so that Vout becomes a voltage that drives the bimorph 3A by ITP.

Next, when the H8W signal becomes No Irepel.

Transistor q is turned on, and the charge stored in capacitor C1 is discharged through the resistor, resulting in a waveform shown by Q in FIG. 8.

As described above, the waveform of the potential Vout at point (b) in FIG. 7 has a slope proportional to the frequency of the capstan FG signal, that is, the tape speed T (the tape speed during recording is assumed to be 1). However, as is clear from the description of the conventional example described above, the deviation in the inclination of the head scan with respect to the recording track is proportional to (T-1), so this correction is necessary.

In other words, the above-mentioned stay pattern signal can be subtracted from the potential at point (b), but the operation of creating this stay pattern will be explained below. When the level is low, capacitor C2 is charged.

The change in potential at point (C) shown in FIG. 8 becomes a triangular wave with a constant slope. Also, when the H8W signal is at high level, transistor q is turned on.

The charge stored in the capacitor C2 is discharged through the resistor R4, and a waveform as shown in FIG. 8 (C) is obtained.The current of the time constant current source 46 is:

The capacitor C7 may be set to a value such that the potential difference across the capacitor C7 becomes the potential difference necessary to fully drive the bimorph by ITP in 1/6 o seconds when the capacitor C7 is charged.

Then, the potential at point (C) is subtracted by the subtracter 43 from the potential at point (b) mentioned above.

A bimorph driving pattern signal having a slope proportional to ('T-1) as shown in FIG. 8(d) is obtained.

This signal is amplified by an amplifier 37 and drives a bimorph 38.

Further, since the pattern signal forming circuit 36 is supplied with a signal obtained by inverting the H8W signal by the inverter 34, a driving pattern signal having a phase difference of 180° from the driving pattern signal obtained from the circuit 35 described above can be obtained. This signal drives bimorph 3B. Therefore, when the heads 2A and 2B trace the magnetic tape, the bimorph 3
A.

3B will be driven.

According to the VTR configured as described above, even if the frequency of the capstan FG signal is low, by changing the capstan FG signal to a fully continuous voltage, a good analog bimorph drive pattern signal without two-step change can be obtained. can get. Therefore, the recording track can be traced more faithfully than in the case of using a driving pattern signal including step-like voltage changes as in the prior art. Also, since LPFy is not used on the output side, there is no step-like voltage change, so the transition means (
The mechanical resonance phenomenon of bimorphs can also be prevented.

In addition, by using a charging/discharging circuit, each head 2A
, Bimorph 3 just before 2B traces the magnetic tape
Since changes in the voltages applied to A and 3B are extremely gradual, it is possible to prevent mechanical resonance of the bimorph even during head switching.

Furthermore, since the above-described embodiment does not use a CTL signal to form the driving fixed pattern signal, it can also be applied to VTRs of the type that do not record CTL signals, which have been increasing in recent years with the trend toward higher density recording. O FIG. 9 is a diagram showing the main part configuration of a VTR as another embodiment of the present invention. The VTR of this embodiment is also capable of obtaining a pattern signal for driving a transition means such as a bimorph without using a CTL signal. In Figure 9, the second
Components similar to those in the figure are given the same numbers. This figure shows an example of the structure of a pattern signal generation circuit that replaces the pattern signal generation circuit 15 of FIG. 1. In FIG. 56 is a terminal to which a power-up clear pulse (PUC), which will be described later, is input; 57 is an RS configured to be reset by the PUC and to be selected by the rise or fall of a timing signal from the timing signal generation circuit 21;
Free knob flop.

58 is a lower binary counter that counts the capstan FG signal from the input terminal 17;
The output of the VCO 62 related to the signal for one frame, that is, 2
At the point when TP is received, the O (- flow signal (hereinafter referred to as O
It is configured to self-reset or return to zero while outputting an F-fold signal.
The output is applied to the reset input of the lower counter 58,
The counter 58 remains in the reset state as long as its reset input is NO, and when it goes low.

59 is an upper binary counter for counting the overflow signal from the lower counter 58; 60 is an upper binary counter for counting the count output of the lower counter 58 as lower binary data; This is a D/A converter similar to the D/A converter 23 in FIG. 2, which inputs the count output of the counter 59 as upper binary data and converts the combined count value from D/A. 61 is the capstan FG input to terminal 17
This is an FV converter that performs F-V conversion (frequency-voltage conversion). 62 is a VCO whose oscillation frequency changes according to the output voltage of the FV converter 61, and its oscillation frequency is set much higher than the frequency of the capstan PG signal. The second one is a high frequency oscillator.

Next, the operation of the pattern signal generation circuit having the above configuration will be explained with reference to FIG. 10 and FIGS. 11(A) and 11(B). 1 ((d-1) to (g-1) in Figure 1)
is for 1.5x playback, (d-2) to (g-2) is for 3x playback, and (d-3) to (g-3) is for lower counter 58 for 0.6x playback. The count output, the count output of the upper counter 59, the composite count output of the counters 58 and 59 (or the output of the D/A converter 60), and the output of the adder 2 are all shown. A
) and (B) show the relationship between the scanning Ω center locus of the heads 2 and 2B with respect to the center locus of the recording track on the tape l during 3x speed playback and 0.6x playback, respectively. When the power is turned on or the flip-flop 57 is set to playback mode, the flip-flop 57 is reset and its Q output goes high, which causes the lower counter 5 to
8 will be maintained in the reset state. Next, the head motor 5 starts rotating the heads 2A and 2B.

Accordingly, when the HSW signal as shown in FIG. 10(a) is output from the rotational phase detector 6, the timing signal generation circuit 2J outputs the HSW signal as shown in FIG. As shown in FIG. 10(b), a timing signal synchronized with each rise and fall of the H8W signal is output.

Since the timing signal knob flop 57 is set by the timing signal generation circuit 21 and its Q output becomes low, the lower counter 58 is released from the reset state, and from then on, the V
The output signal of CO62 will be counted. Also,
The upper counter 59 is reset every time a timing signal is generated.

Here, the output signal of the VCO 62 is the one obtained by multiplying the capstan PG signal, so the capstan PG signal
If the number of signals generated in 2TP is known, the number of pulse signals generated by the VCO 62 can also be known. Therefore, as described above, the lower counter 58 outputs the OF multiplied signal when it receives 2 TP of pulses generated by the VCO 62 and also resets itself or returns to zero, so its count output is 1.
When playing at 5x speed, it is as shown in Figure 10 (d-1), when playing at 3x speed, it is as shown in Figure 10 (d-2), and when playing at 0.6x speed, it is as shown in Figure 10 (d-3). become.

At this time, the count output of the upper counter 59 that counts the OF multiplied signal from the lower counter 58 is as shown in FIG. 10 (e-) during 1.5 times speed playback, and as shown in FIG. Like c-2).

Further, when playing back at 0.6 times speed, the result becomes as shown in FIG. 10 (e-3). Therefore, the combined count output of these counters 58 and 59 (or the output of the D/A converter 60) is as shown in FIG. 10 (f-1) during 1.5 times speed playback, and as shown in FIG. Like f-2).

Also, for 066 times speed playback, the result is as shown in FIG. 10 (f-3).

In this way, instead of directly counting the CABSUKUN FG signal, the 10th
An ideal counter output as shown in the figure can be obtained.

On the other hand, the oscillator 27' oscillates a predetermined high frequency pulse.

By counting this with the counter 28 and resetting it with a timing signal, a stay pattern signal having the same phase as the fixed pattern signal obtained by the D/A converter 60 can be obtained. This stay pattern signal is 8) ¥10 figure (C)
As shown in (1), heads 2A and 2B are
A signal for continuously changing the value from 0 to -ITP is used. The oscillator 2 also uses this stay pattern signal.
Since the output pulse 7' has a high frequency, a pattern close to an ideal one showing smooth changes can be obtained.

As a result, from the adder 25, the D/A converter 6 at this time
As a result of adding the output of 0 and the output of the stay pattern generator 24, a pattern signal as shown in FIG.
A pattern signal as shown in g-2) is output, and a pattern signal as shown in Fig. 10 (g-3) is output during 0.6x playback. The pattern signal during playback at 15 times the speed is equivalent to the pattern signal shown in FIG.
It is clear that the required displacement of the heads 2A and 2B during 5x speed playback can be satisfied.

On the other hand, when playing at 3x speed and when playing at 0.6x speed, the first
If you consider it with reference to Figure 1 (A) and (B) ffi,
First, during triple speed playback, the head trajectories of heads 2A and 2B with respect to the track trajectories on tape l are as shown in FIG. 11(A).
It will look like this. That is, in Figure 2.

Same as in Figure 4(B) + A+ + A2 +
A, , . . . Head locus of head 2A -q
, B, , B2.13. ,... is head 2
The head trajectory of B is 1 ”II B2. B3°...
. . . indicates the track locus of a finild track recorded by a recording head having the same azimuth angle as heads 2A and 2B (this is explained in the 11th
The same applies to Figure (B)).

In the first field, the head trajectory A1 is the track trajectory a,
In order to match this, it is necessary to continuously give the two heads a shift from O to +2TP within the scan of the first field, and in the second field, match the head trajectory B+' to the next track trajectory a2. Therefore, it is necessary to continuously give head 2B a transition from +112 minutes to +3 TP division within the scanning of the second field.Hereinafter, this will be repeated every two fields. Figure 10 (
I understand that it is something.

Also, during playback at 0.6x speed, the head trajectories of heads 2A and 2B with respect to the trunk trajectory on tape 1 are shown in Figure 11 (B
) as shown below. That is, in the first field, in order to match the head trajectory A+'ff:) rack trajectory a1, the two heads are changed from 0 to -0, within the scanning of the first field.
It is necessary to continuously apply a shift of up to 4'rp, and in order to match the head trajectory B+ with the track trajectory a in the second field, the head 2B is shifted from +0.6TP to +0. It is necessary to apply the displacement up to 2TP continuously, and in order to match the head trajectory A2 with the track trajectory a in the third field, +1.2 is applied to the head 2A within the scanning of the third field.
It is necessary to continuously apply the displacement from TP minute to +0.8 TP minute, and in the fourth field, +1.8 T is applied to head 2B within the scanning of the fourth field in order to match the head trajectory B2 with the track trajectory a. +1 from p
．． It is necessary to continuously apply a shift of up to 4 T P, and in the fifth field, the head trajectory A3 is +0.4' within the scan of the fifth field to match the next track trajectory a2 of the k order. It is necessary to provide a continuous transition from I'P to O.

In the 6th field, in order to match the head trajectory B and the track trajectory a, it is necessary to continuously give the head 2B a shift of +0.6 T P from +112 within the scan of the 6th field. In the 7th field, head trajectory A4 'fc Similarly, in order to match the track trajectory a2, +1 within the scanning of the 7th field for 2 heads.
．． It is necessary to provide a continuous transition from 6 TP minutes to +1.2 TP minutes, and in the 8th field, the head trajectory 8
4, it is necessary to continuously give the head 2B a shift from +0.2 TP to -0.2 TP within the scanning of the 8th field, and in the 9th field, the head 2B Similarly, in order to match the trajectory A with the track trajectory recommendation, it is necessary to continuously give the head 2A a shift from +0.8 TP to +0.4'rp within the scan of the 9th field, and in the 10th field, the head Trajectory B5 is also track trajectory a.

+1.4' within the scan of the 10th field for head 2B to match the ! It is necessary to continuously give a transition from 'P minute to →-]'l''P minute, and the above will be repeated every 10 fields.
It can be seen that the pattern signal shown in FIG. 10 (g-3) can satisfy the necessary changes of the two heads and 2B.

Even in the VTI% of the above configuration, the cabtan FG
By once converting the frequency of the signal into a voltage, the number of pulses to be counted can be freely set to a large number, so that a good analog bimorph driving pattern signal without two-step change can be obtained. Therefore, during variable speed playback, the recording track can be faithfully traced, and the drive back/
The phase delay of the signal is also very small, and the mechanical resonance phenomenon of the shifting means due to one-step change can be prevented. Furthermore, although the explanation of the above embodiment does not mention reverse playback,
For reverse reproduction, it is sufficient to take measures such as inverting the output of the subtraction circuit 43 or the output of the D/A converter 60.

Furthermore, as is well known, an auto-tracking signal is formed based on the pilot signals being reproduced from the heads 2A and 213, and this signal is added to the output of the subtracter 33 and the adder 2, thereby achieving even more fine-grained tracking. Tracking becomes possible.

As explained above, according to the present invention, the moving means of the rotary head is driven by using the second signal having a voltage corresponding to the frequency of the first signal related to the transport operation of the recording medium. Therefore, even if the frequency of the first signal is low, an analog-like and good driving signal without a single step change can be obtained. Therefore, it is possible to obtain a rotary head type reproducing device that can trace the recording track extremely faithfully, does not cause a phase delay in the driving signal, and is also less likely to cause mechanical resonance of the shifting means.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a schematic configuration of the main parts of a conventional VTR. FIG. 2 is a diagram showing an example of the pattern signal generation circuit of the V'TR shown in FIG. 1. FIG. 3 is a diagram showing ideal waveforms of each part of the second part. Figures 4 (A) and (B) are respectively during still playback and 1
．． FIG. 7 is a diagram showing the relationship between recording tracks on a tape and head scanning during 5x speed playback. FIG. 5 is a diagram showing actual waveforms of each part of the second part. FIG. 6 is a block diagram showing the main part configuration of a VTR as an embodiment of the present invention. FIG. 7 is a circuit diagram showing a specific example of the pattern forming circuit shown in FIG. 6. FIG. 8 is a diagram showing the waveform of the seventh joint portion. FIG. 9 is a diagram showing the main part configuration of a VTR as another embodiment of the present invention.゛Figure 10 is a diagram showing the waveform of the numbered part in Figure 9. Figures 11 (A) and (B) are for 3x speed playback and Q, 6
FIG. 3 is a diagram showing the relationship between recording tracks on a tape and head scanning during double-speed playback. 1 is a magnetic tape as a recording medium; 2A and 2B are rotary heads; 3A and 3B are bimorphs as displacement means; 10 is a capstan; 11 is a capstan motor;
12 is a capstan FG signal generator as a signal for l'81, and 33 is an FV converter. 35 and 36 are pattern forming circuits, 58 and 59 are counters, 60 is a D/A converter, 61 is an FV converter, and 62
is a VCO. Tan Ko 6 Figure 7 Figure 8 (d).

Claims (1)

[Claims] 1) A recording signal is generated by tracing recording tracks formed at a predetermined arrangement pitch on a recording medium transported by a transporting means with a rotary head that is displaced by a displacement means in a direction perpendicular to the rotation surface of the recording medium. The apparatus includes means for obtaining a first signal having a frequency related to the recording medium transporting operation of the transporting means, and a second signal having a voltage corresponding to the frequency of the first signal. and means for forming a control signal for said displacement means based on said second signal.