JPS59229734A - Video tape recorder - Google Patents

Abstract

PURPOSE:To produce a smooth and faithful mobile head driving pattern and to obtain a reproduction screen of high quality by synthesizing a still pattern, a tape shift speed and an error pattern to obtain a driving pattern of a head driving actuator in a slow reproduction mode. CONSTITUTION:A mobile head driving pattern generating circuit 17 is provided with a still pattern memory 40, an error counter 41 and an error correcting arithmetic device/memory 42. A control part 28 selects the memory 40 out of basic pattern memories corresponding to each mode by an action mode signal 16 of a VTR. Then the part 28 delivers still patterns 33 successively in the timing to divide a field synchronous with an H-SW signal 5 into eight parts, for example. It is decided by the signal 5 and a 2P shift command signal 2P-SFT given from the error correcting arithmetic device 42 to select a tracking pattern 44a, a forwarding pattern 44b, a -2P shift pattern 44c or a +2P shift pattern 44d out of the patterns 33.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video tape recorder (hereinafter referred to as "rVTR"), and particularly relates to an improvement in the auto-tracking pattern generation portion using a movable head of an auto-tracking VTR.

In a helical scanning VTRk, the video track on the magnetic tape on which the signal is recorded does not match the trajectory of the video head during static playback, slow playback, or high-speed playback. Therefore, the reproduced image quality deteriorates. Therefore, a conventional method has been used in which the video head is mounted on, for example, a piezoelectric element, the video head is displaced by the piezoelectric element, and the video track and the trajectory of the video head are made to coincide with each other to obtain good image quality. This is called auto-tracking using a movable head (hereinafter simply r
(referred to as ATJ).

As one of the AT methods, an absolute phase method using a control pulse and a capstan motor FG signal is known. Another method is a pilot signal method that uses pilot signals recorded at different frequencies for each video track (also called the 4c method because four types of pilot frequencies are sequentially switched and used).
It has been known. Here, the 4c method will be explained as an example.

Figure 1 shows the videotape recording pattern in the 4c system, Figure 2 shows the AT system block diagram, Figure 3 shows an example of the relationship between the fixed head and the video track during 1/4 slot playback, and Figure 3 shows the relationship between the fixed head and the video track during 1/4 slot playback. FIG. 4 shows an example of a movable head drive pattern during 4-slot playback, and a block diagram of the movable head drive pattern generator 17 of the conventional device is shown in FIG. FIG. 5 shows an example of a pattern memory for creating a movable head drive pattern using a conventional device, and FIG. 6 shows an example of a conventional movable head drive pattern.

In the figure, 1 is a videotape, 2.2a, 2b, 2c
is the video track (see Figure 1 above), 3a.

3b are video heads mounted on opposing peripheral surfaces of a rotary cylinder (not shown) separated by 180 degrees; 4a;
, 4b are video heads 3a, respectively.

3ill is attached to the piezoelectric element, '5 is the video head 3a
.

Head switching signal (H/
SW), 6a and 6b are reproduction signals obtained by the Bei'A heads 3a and 3b, respectively, 7a and 7b are amplifiers, 8 is a switch circuit for selecting one of the reproduction signals $68.6b, and 9 is a reproduction signal 10 is a regenerated pilot signal B;
), il is a carrier signal (fcll), 12 is a balanced mixer, 13a, 13b are band pass filters, 14a, 14
b is an amplitude detector, 15 is a comparator, 16 is a VTR operation mode signal (MD), 17 is a movable head drive pattern generator (P, T, G,), 18a, 18b are low-pass filters, 19a, 19b is a piezoelectric element 4a.

4b (see Figure 2 above), 20 is the head trajectory when the movable head is fixed (referred to as the "fixed head trajectory"), and 21 is the head on the video tape 1 during normal recording and playback. Trajectory (referred to as “normal head trajectory”), 2
2 is a speed vector (VS) for normal playback speed (referred to as r playback speed vector j), 23 is a speed vector (1/4 vs) for 1/4 slow playback speed (referred to as r1/4 slow speed vector), 24 is the head trajectory on the video chip 11 during 1/4 slot playback (referred to as the "rl/4 slot temporary head trajectory") (see Figure 3 above), 25 (25a
, 25b, 25c, 25d, 25e)
&t1/4 slow playback verse playback head drive pattern, 2
6 is a movable head drive pattern during static playback (referred to as "still pattern J"), a pattern corresponding to the movement of the 27u tape (referred to as "tape movement pattern") (mainly shown in Figures 14 and 7), and 28 is a movable head drive pattern (referred to as "still pattern J"). A control unit for the head drive pattern generator 17, 29 a still pattern memory, 3
0 is a tracking error pattern memory (hereinafter referred to as "error pattern memory"), 31 is a tracking error pattern correction calculation unit (hereinafter referred to as "error correction calculation unit"), and 32 is a drive pattern calculation v! #Vessel and memory, 33
is the still pattern (PN), and 34 is the error pattern (E
N>, 35 (35a, 35b) are driving patterns (ONl #ON2), 36a, 36b are digital/analog converters (mainly shown in Figs. 5 and 6).
Figure).

Returning to Figure 1, the pilot signal r++'2*' @ recorded by the 4c method of a helical scanning VTR
*f4 is generally 102KHz and 118K respectively
l-1z, 164KHz, 148Hz. In this way, Yf! J! , The frequency is sufficiently low compared to the C signal, and the difference between adjacent no\lot signals is 16KH.
2 and 46Kl-(Z, l, and N are set to predetermined values.Also, f, and f, and GO are azimuths (c)
-11 head) side, f2 and f4 are the other azimuth (C
H2 head) side video track.

In FIG. 2, the video heads 3a and 3b have different azimuths, and are mounted and mounted on the circumferential surface of a rotary ceiling (not shown) at a distance of 18Q6. The video heads 3a, 3b are mounted on piezoelectric elements 4a, 4b such as a roof.

Here, video heads 3a, 3b and piezoelectric element 4a.

4b is called a movable head, 32. The movable head is configured to be displaceable in a direction perpendicular to the direction of rotation of the rotary cylinder. It is assumed that the switching signal (1-1/5W) 5 for the video heaters 1ζ 3a and 3b is /

3b are respectively the CHI side and the Cl-12 side.

Next, the operation will be explained. Referring primarily to FIGS. 1 and 2, the operation in the normal playback mode will first be described.

Now, video track 2 on which pilot signal f is recorded
Suppose that the video head 3a is tracing a. At this time, pilot signals t2 and f4 recorded on adjacent tracks are mixed into the reproduced signal 6a as a crosstalk signal. The reproduction signal 6a is amplified by a reproduction amplifier 7a, passed through a switch circuit 8, and is converted into a reproduction pilot signal (fp) 10 by a filter 9 that selectively passes the pilot signal.
is obtained. rp 10 includes f, and fz and f* as crosstalk. The carrier signal (fcR) 11 is set to the same frequency as f, and fplo and fc*11 are input to the balanced mixer 12. As a result, the output of the balanced mixer 12 has If+f41-46KH2 and If
+ f t l-16KHz component is generated. With the bandpass filter 13a having a center frequency of 16KH2 and the bandpass filter 13b having a center frequency of 46Kl-IZ,
Each component is extracted and detected by the detection circuits 14a and 1.
4b converts it to a DC level, and each compares it to a comparator 15.
Compare with. If the output of the detection circuit 14a is
4b, it means that the video head 3a is biased toward the video track 2b where the pilot signal f2 is recorded.

The drive pattern generation circuit 17, which is generated by a microcomputer or the like, corrects this deviation based on the output of the comparator 15 and the tVTR operation mode signal 16, which indicates normal playback, static playback, and slow restart. Generates a movable head drive signal for modification. Then, the movable head drive signal is smoothed by a low-pass filter 188 that smooths the signal to such an extent that the piezoelectric element 4a does not generate abnormal vibrations, and is supplied to the piezoelectric element 4a via the movable head drive amplifier 19a. As a result, the balance of crosstalk between the pilot signals from the adjacent 1-rack reproduced by the video head 3a changes, and a servo loop is formed.

Further, almost the same operation is performed on the CH2 side.

Although the explanation is omitted here, the video head 3a
, 3b is also operated to reduce the signal tJ\ for correcting the offset of the capstan motor control system (not shown).

Next, the control operation of the movable head in the slow reproduction mode will be explained.

In FIG. 3, the normal head trajectory 21 can be expressed as a composite vector of the head trajectory 20 of the G, E video head 3a (or 3b) and the normal playback speed vector 22. Therefore, as long as the video tape 1 moves at the same speed VS as during recording, the normal head trajectory 21 maintains a flat 11 relationship with the video track 2.

However, when the moving speed of the video tape becomes, for example, 1/4 during slow playback, the playback speed vector becomes 1/4V8. Therefore, a 1/4 slot temporary head trajectory 24 is obtained as a composite vector of the 1/4 slot velocity vector 23 of this 1/4 VS and the trajectory 20 of the video head 3a.

Further, this 1/4 slot temporary head trajectory of 24% changes as 24a, 24b, 24C and 24d as the video tape 1 moves. At this time, in order to obtain a good signal, it is necessary to displace the piezoelectric element 4a to align the video head 3a with the head trajectory 21 during normal reproduction.

Displacing the video head 3a vertically upward (to the upper right in FIG. 3) with respect to the rotational direction of the rotary cylinder is defined as a negative direction, with respect to the 1/4 slot temporal head trajectory 24a to 24d in FIG. The video head drive patterns are shown in FIG. 4 as head drive patterns 25a to 25d during 1/4 slot playback. These 1/4 slot playback head drive patterns 25a to 25d are H-8W5
This is obtained by combining a Sannai-shaped still pattern 26, which is 1P in 1/2 cycle, and a tape movement pattern 27 corresponding to the movement of the video track 2a. conventional 4f
In this method, no external signals are used to create the tape movement pattern 27. Therefore, the tape movement pattern 27 must be obtained from a signal corresponding to the amount of mistracking.

FIG. 5 shows an example of the configuration of the drive pattern generation circuit 17 in the conventional device. In the figure, the control unit 28 controls V
Based on the TR operation mode signal (MD) 16, a predetermined one is selected from various patterns, and the contents of the memory are transferred to the drive pattern calculator/memory 32 at a predetermined timing synchronized with the H-8W5. Similarly, the control unit 28 controls an error correction calculator 31 that corrects the error pattern using an error pattern memory 30 and a signal corresponding to the amount of mistracking, for example, the output of the comparison calculator 15. The drive pattern calculation/memory 32 calculates and obtains a drive pattern 35 based on the output still pattern (PN) 33 of the still pattern memory 29 and the output error pattern (EN) 34 of the error pattern memory 3o. The above part is
It usually consists of a microcomputer. The driving patterns 35a and 35b are generally converted from digital signals to analog signals by digital/analog converters 36a and 36b, respectively. Below, the drive pattern 35a
, 35b will be explained.

In FIG. 6(a), one field is divided into eight blocks, and the still pattern memory 29, error pattern memory 30, and movable blocks corresponding to each block are divided into eight blocks.
A drive pattern memory 32a for driving the rad is provided, and the tape movement pattern 27 is made to correspond to the contents of the error pattern memory 30. For example, consider the fourth block. The fourth drive pattern memory 32a
The first content O9 is composed of the sum of the fourth contents of the still pattern memory 29 and the error pattern memory 30, and is expressed as 04-P4+E4 (1). This 0. As a result of driving the movable head, the output of the first amplitude detector 14a shown in FIG.
If it is larger than b, the video head 3a must be lowered. Therefore, it is necessary to increase the error E4 by a predetermined value.

If the current error is E4 (io), the error after correction is E* (j +), and the predetermined value is α, then E4 (t +
) −E4 (to )+α ・(2).

Conversely, if the output of the first amplitude detector 14a is small, E4 (t+)-E4 (to)-α-(
3). The contents of the error pattern memory 30 obtained in this way basically match the tape movement butter>27.

FIG. 6(b) is a representation of the Al-A2 pattern in FIG. 4 in the memory of FIG. 6(a). In FIG. 6(b), a still pattern 33, an error pattern 34, and a drive pattern 35 correspond to the still pattern memory 29, error pattern memory 301, and drive pattern memory 32a, respectively.

Now, the error EN (N-1, 2,..., 8) is
Although it is corrected by the above formula (2) or (3), the fourth
Al-A3 in the figure was corrected, and 81-8
It does not give a 3. Therefore, in order to obtain B1-83, the slope ΔA of A1-A3 is calculated, and ΔA
is added to the error pattern memory 30 corresponding to Al-A3. EN the contents of error pattern memory 30
(N-1, 2,...

8), and if the slope (difference between A1 and A2) is Δ, then Es
(t + >-EN (to) Sat α+2Δ-(4)
It can be expressed as Also, whether the transition to El-E3 or AI--A3- during Dl-D3 is determined by the obtained EN
Judging by ([,), if it moves to AI--A3-, EX (t+)-EN (to)±α+2Δ-
2P-(5) Modify the contents of the error pattern memory 30 as shown below.

FIG. 7 shows an example of a 1/4 slot temporary driving pattern using the above method. A1→A2→A4→81→・・・→C
4 → D1 is a pattern according to the above equation (4),
D2→D4−→A1− is a pattern according to the above equation (5). Note that in FIG. 7, the number of divisions N of one frame is set to infinity for simplicity.

A conventional head drive pattern during slow playback is generated in the manner described above. Therefore, the drive pattern had acute angle portions, such as points A2, A4, 82, and 84 in FIG. If a piezoelectric element such as a bimorph is driven with a pattern having such an acute angle, abnormal vibrations may occur at the acute angle portion, so it is necessary to use a filter that makes the acute angle portion clear. Furthermore, since the driving pattern must be predicted and determined based on the error pattern, this predictive calculation takes time and there is a drawback that the number of divisions of one field cannot be increased.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional VTR. SUMMARY OF THE INVENTION An object of the present invention is to provide a VTR that improves the method of generating a head drive pattern during slow playback, improves the followability of a movable head, and obtains good reproduced images.

Simply put, this invention shortens the prediction time by introducing a counter that predicts an error signal using a frequency signal corresponding to the tape movement speed, and still patterns can be used for tracking, forwarding, etc. The movable head drive pattern can be smoothed and prediction calculations can be simplified by dividing the two-track pitch shift pattern, storing each pattern in advance in memory, and reading and using each pattern from the memory as needed. This VTR is equipped with a pattern generating means that can generate a good drive pattern even when the tape speed changes as in variable speed slow playback.

The above-mentioned objects and features of the present invention will become clearer from the following description of embodiments with reference to the drawings.

FIG. 8 is a configuration diagram of a movable head drive pattern generation circuit 17 according to an embodiment of the present invention. In the figure, 40 is a still pattern memory, 41 is an error counter, and 42 is an error correction calculator/memory. Note that the configuration of other parts is the same as that shown in FIG. 5, and the same or corresponding parts are given the same numbers and the description thereof will be omitted here. Further, the configuration of the AT system circuit including this movable head drive pattern generation circuit 17 is similar to the configuration shown in FIG. 2 described in the conventional example, and its description will be omitted here.

FIG. 9 shows a timing diagram of the main signals in the operation of this embodiment. Furthermore, FIGS. 10 and 11 are examples of drive patterns of this embodiment for forward direction 1/4 slow playback and reverse direction 1/4 slow playback, respectively. 10 and 11, 27 is a tape movement pattern, 43 is an error pattern, 44a is a still pattern tracking pattern, 44b is a forwarding pattern, 44
C is an example of a 12P shift pattern, 44d is a +2P shift pattern, and 45 and 46 are examples of forward and reverse 1/4 slot one playback head drive patterns.

Next, the operation of this embodiment will be explained.

In FIG. 8, the control section 28 selects, for example, a still pattern memory 40 from basic pattern memories (not shown) corresponding to each mode in response to the operation mode signal 16 of the VTR. Furthermore, the control unit 28 sequentially outputs still patterns (PM) 33 at the timing of dividing the 17 keeled into 8, for example, in synchronization with the H-8W signal @5, which is a signal as shown in 0LGK in FIG. Of the still patterns 33, tracking patterns 44a9 forwarding patterns 44b, -2P shift patterns 440 and +2
Which of the P shift patterns 44d is selected is determined by the H-8W signal and the 2P shift command signal 2P-8FT from the error correction calculator 42, as shown in FIG. 10, for example.

In FIG. 10, 81-82. B5-84゜85-8
6, 87-88. The tracking pattern 44a is selected for B9=-810, the forwarding pattern 44b is selected for B2-83.84-85.86-87, and the 12P shift pattern 440 is selected for B8-89.

The error counter 41 uses the error output E of the error correction calculator/memory 42 as an initial value in response to an error initial value setting command signal LOAD similar to CLCK in FIG. Pulse V
pls (For example, count the FG multiplication signal of the capstan motor and obtain the error signal E. Also, as a result,
Tape movement pattern 27 like A1-A3 in FIG.
get.

Note that the control unit 28 outputs a signal F/R indicating whether or not the tape is moving in the forward direction. This F/R (!
The error counter 41 counts up or down depending on the signal.

The error correction calculator/memory 42 samples the output (error signal) E of the error counter 41 using a read signal RD-ER similar to 0LGK in FIG. to communicate.

On the other hand, the error correction calculator/memory 42 corrects the error pattern (EN) based on the output of the comparator 15 that detects tracking errors. Now, if it is necessary to increase EN by a predetermined value, the correction value E is Es = Es + α...(6), and conversely, if it is necessary to decrease it, EN-EN-α...( 7). This situation is shown in FIG. Of course,
If there is no need to increase or decrease, the error pattern EN will not be corrected.

If the amount of EN or EN exceeds a predetermined value, that is, if the drive patterns 35a and 35b are too far in one direction, it is necessary to make a correction by two track pitches. In this case, the error correction calculator/memory 42 transmits this correction command to the control unit 28 as a 2P shift command signal 2PSFT.

Note that the operations of the drive pattern calculator/memory 32 and the like are similar to those of the conventional example explained in FIG. 5 above.

Next, generation of a drive pattern will be explained with reference to FIG.

The error pattern (E) 43 is successively corrected while tracking errors are detected. Therefore, in general, the ninth
The shape will look like the one shown in the figure.

On the other hand, when the error EN is within a predetermined value, the still pattern 44 becomes a repetition of the tracking pattern 448 and the forwarding pattern 44b. At this time, the forward direction 1/4 slow playback drive pattern 45 is A1→A2→A3→・
...→ Obtained as shown in A8. Now, between 6 and 88,
-2P shift becomes necessary, 2PSF1-
The signal is transmitted to the control unit 28. As a result, 88→A
9', the -2P shift pattern 44c is selected. Then, drive pattern 4 during forward 1/4 slow playback
When 5 reaches A9', error pattern (E) 43
has reached A9. Here, the error pattern (E
)43 by -2 track pitches, A9-→
The forward direction 1/4 slow playback drive pattern 45, which is AIO→A11 .

By this -2 track pitch shift, if video track 2a is being played back, video track 2c will be played next.

Reverse 1/4 slow playback shown in FIG. 11 is performed in the same manner.

In the above description and configuration, the tape movement pattern 27 and the error pattern 43 are made to match for the sake of simplicity. However, these do not necessarily match, nor will any inconvenience occur if they do not match.

As shown above, the drive pattern during slow playback is calculated by counting the still pattern consisting of the tracking pattern 44a9 forwarding pattern 44b, the -2P shift pattern 44C, and the +2P shift pattern 44r+, and the speed pulse VpS corresponding to the tape movement speed. The error pattern obtained by
E) 43, basically a smooth driving pattern can be obtained.

Further, there is no need to perform predictive calculations of error patterns, so there is no problem of calculation errors, and there is an advantage that even when the tape moving speed changes, it can be followed sufficiently.

Yet again, 111! Error pattern (E) 4 on the instep
3 and the still pattern 44, so
The calculation time can be reduced compared to conventional devices. Therefore, the number of divisions per field can be relatively large, and a smooth drive pattern can be obtained.

Furthermore, since the drive pattern becomes smooth, the smoothing filters 18a, 18b can be replaced with a very simple R-
There is a possibility that a C-type integral filter can be used.

In addition, in the above embodiment, only the CH1 side was explained, but CH211! The same applies to l.

Further, although the description has been made on the case where CH1 and CH2 have different azimuth angles, the same effect can be obtained even when they have the same azimuth angle. Furthermore, although the explanation has been given using forward/reverse 1/4 slow playback as an example, it should be pointed out that it is also effective for playback at other speeds including very low speed and stationary speed.

Further, although a piezoelectric element has been described as an example of the head drive actuator, other devices such as a moving coil may also be used.

Further, although the case where one field is divided into eight parts has been described, the number of divisions may be larger or smaller than eight.

Further, although the VTR system has been described as a 4f system, it should be added that the present invention can also be applied to a system in which an error pattern is obtained by increasing or decreasing the level of a reproduced video signal.

In this embodiment, the pattern generation circuit 17 is composed of a microcomputer, a counter, and a digital/analog converter. However, it is also possible to use a microcomputer, including the counter, for example. Conversely, it may be configured with discrete circuits without using a microcomputer.

As described above, according to the present invention, the head drive actuator drive pattern during slow playback is composed of a still pattern consisting of a tracking pattern, a forwarding pattern, a -2P shift pattern, and a +2P shift pattern, a tape movement speed, and a tracking error signal. Since it is obtained by combining the error pattern with the error pattern obtained based on can.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram showing the recording pattern of a videotape in the 4F system. FIG. 2 is a conventional AT system block diagram. FIG. 13 is a principle diagram showing the relationship between the fixed head and the video track during 1/4 slot playback. FIG. 4 is a waveform diagram of the movable head drive pattern during 1/4 slot reproduction. FIG. 5 is a configuration diagram of a conventional movable head drive pattern generation circuit in the stomach. FIG. 6 is a diagram showing an example of a conventional pattern memory for creating a movable head drive pattern in @[fl. FIG. 7 is a waveform relationship diagram of a movable head drive pattern during 1/4 slot reproduction in a conventional apparatus. FIG. 8 is a block diagram of a movable head drive pattern generation circuit according to an embodiment of the present invention. FIG. 9 is a timing diagram of the main signals in FIG. FIG. 10 is a diagram showing an example of a drive pattern for forward 1/4 slow playback according to an embodiment of the present invention. FIG. 11 is a diagram showing an example of a drive pattern for reverse direction 1/4 slow playback according to an embodiment of the present invention. In the figure, 1 is a video tape (magnetic tape), 2 is a video track, 3a, 3b are video heads, 4a, 4
b is pressure N element (head drive actuator), 6a, 6
b is the regenerated signal q110 is the regenerated pilot signal, 15
is a comparator, 161; IV-R operation mode signal, 17
19t is a movable head drive pattern generation circuit, 19t is a movable head drive amplifier, 20 is a fixed head trajectory, 21 is a normal head trajectory, 22μ is a normal playback speed vector, and 23 is 1/'4
Slow vibration vector 1-1, 24 is 1/', 4 slot temporary head trajectory, 25 is 17/4 slow/movable head drive pattern during playback, 26 is still pattern, 27 is tape movement pattern, 28 is control section, 29 is a still pattern memory, 30 is an error pattern memory, 31 is an error correction calculator, 32 is a drive pattern calculation IT/memory, 33 is a still pattern, 34 is an error pattern, 35 is a drive pattern, 36 is a digital/analog converter , 37 is a drive pattern generation circuit output, 40 is a still pattern memory,
41' is a nilla counter, 42 is an error correction calculator/memory, 43 is an error pattern, 44 is a still pattern, 44a is a tracking pattern, 44b is a forwarding pattern, 440 is a -2P shift pattern, 44d is a +2P shift pattern, 45 and 46 indicate drive patterns for forward and reverse 1/4 slot playback. Agent Masuo Oiwa Figure 1 Figure 30 iiN ゝ ・ Q 7 yo θ (p & (Tokenba Yudeki Suga-A Gai procedural amendment (spontaneous) 1. Indication of the case Patent Application No. 103057-1982 2,
Title of the invention: Video tape recorder 3, Person making the amendment 5, Detailed description of the invention in the specification subject to amendment 6, Contents of the amendment (1) Page 4, line 17 of the specification and page 7, line 17 Correct r(H/5W)J to r(H-8W)J. (2) "H-8W signal as shown" on page 18, line 19 to line 20 of the specification is replaced with "H-8W signal as shown"
Correct to 8W signal. that's all

Claims (1)

[Scope of Claims] A magnetic tape recording medium on which a video signal is recorded, comprising at least one pair of movable heads consisting of a head drive actuator that is displaced in accordance with an applied electric signal and a video head coupled to the actuator. A video tape recorder including a device for obtaining a playback signal by tracing a video track with its movable head, comprising: tracking error detection means for detecting a tracking error of the movable head based on the playback signal; A pattern generating means for generating a driving pattern, the pattern generating means having a basic format in which one field is divided into integers, including the video track tracing pattern, the video head forwarding pattern, and the video head two-track pitch shifting pattern. means for storing patterns; means for selecting the forwarding pattern and the pattern for two-track pitch shifting of the basic pattern based on the error pattern; means for generating the drive pattern by sequentially combining the error pattern with the basic pattern, the drive pattern being generated from the signal and the moving speed of the magnetic tape, and further comprising: the drive pattern output from the pattern generation means; A videotape recorder comprising means for displacing a head drive actuator of the movable head to correct tracking errors of the movable head.