JPH0536042A - Tracking controller for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To execute a stable tracking control in a short time in a tracking controller using electromechanical conversion elements. CONSTITUTION:This controller is provided with a tracking reference value preparing circuit 109 which prepares the reference value of a tracking control, diving data comparing circuit 110 which drives the electric/mechanical conversion elements, direct current component integration circuit 112 which integrates direct current voltage components included in driving data, and detection signal preparing circuit 113 which prepares a detection signal 114 for resetting the tracking reference value from the output value of the direct current component integration circuit 112. When the integrated result being the output of the direct current component integration circuit 112 is beyond a prescribed range, the resetting of the tracking reference value is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tracking control device for a magnetic recording / reproducing device.

[0002]

2. Description of the Related Art In a magnetic recording / reproducing apparatus, when reproducing an information signal recorded on a recording track, it is necessary to perform tracking control for a reproducing head to perform on-track reproduction scanning on the recording track.

A tracking control method practically used has a dedicated control track in the longitudinal direction of the tape, and a control signal is recorded at a frame cycle or a cycle of an integral multiple thereof, and this control signal is reproduced at the time of reproduction. There is a method of performing tracking control by utilizing it. However, this method has drawbacks such as the need for a dedicated control track and the inability to obtain a tracking error signal over the entire recording track.

As another method which has been put into practical use, at least two parallel recording tracks recorded on a magnetic recording medium by a magnetic head having different azimuth angles are simultaneously reproduced and scanned, and at least two different azimuth angles are used. There is a method of using a reproducing head (hereinafter referred to as a reproducing pair head) to detect a track shift of the reproducing pair head based on a time difference between horizontal synchronizing signals reproduced from the heads of the reproducing pair head. In this method, it is not necessary to superimpose a tracking control signal (pilot signal) on the video signal, and time difference data indicating the track deviation of the reproduction pair head can be obtained from the time difference of the reproduced horizontal synchronizing signal. When mounted on an electro-mechanical conversion element composed of a piezoelectric element or the like and the mechanical position of the head is changed using the time difference data, a control system capable of following the track bending can be constructed. Hereinafter, a tracking control device using the azimuth time difference detection method will be described. FIG. 5 shows changes in the reproduction time difference of the horizontal synchronizing signal depending on the positions of the recording track recorded on the magnetic tape and the reproducing pair head. 5, (a) is a plan view showing the positional relationship between the reproducing pair head 502 and the recording track 501 having different azimuth angles, and (b) is a reproducing pair head when the reproducing pair head 502 scans the on-track position. The horizontal sync signal reproduced from 502 is shown. FIG. 11C shows a horizontal synchronizing signal reproduced when the scanning position of the reproducing pair head 502 is shifted to the left from the on-track position. FIG. 11D shows a horizontal synchronizing signal reproduced when the scanning position of the reproducing pair head 502 is displaced to the right of the on-track position. The same figure (b), (c), (d)
, H-sync (A) is a horizontal synchronizing signal H-sync reproduced by the magnetic head A of the reproducing pair head 502.
c (B) is the magnetic head B of the reproducing pair head 502.
Shows the horizontal sync signal reproduced by.

In the figure, reference numeral 503 denotes a horizontal synchronizing signal recorded on a recording track, and arrow 504 indicates the direction in which the reproducing pair head 502 scans the recording track.
The horizontal synchronizing signal reproduced when the reproducing pair head 502 scans the on-track position is reproduced from each head with a time difference T (= 0) as shown in FIG. When the scanning position of the reproducing pair head 502 deviates to the left from the on-track position on the paper surface, the reproducing timing of the horizontal synchronizing signal reproduced by the magnetic head A becomes faster, and the reproducing horizontal synchronizing signal is as shown in FIG. Is reproduced with a time difference T1 corresponding to the track deviation amount of the scanning position, and when the scanning position of the reproducing pair head 502 is displaced to the right on the paper surface from the on-track position, the reproduction timing of the horizontal synchronizing signal reproduced by the magnetic head B is The speed is increased, and the horizontal synchronizing signal is reproduced with a time difference T2 corresponding to the track shift amount of the scanning position as shown in FIG. By obtaining the time difference between the reproduced horizontal synchronizing signals, the track deviation of the reproducing pair head 502 can be detected.

The reproducing pair head is mounted on the electromechanical conversion element, and the reproducing time difference of the horizontal synchronizing signals output from the reproducing pair head becomes the time difference data T obtained when the reproducing pair head reproduces and scans the on-track position. By changing the electro-mechanical conversion element, it is possible to configure a control system in which the reproducing pair head scans the on-track position even if there is a track bend.

However, in the pair head, the mechanical mounting step difference in the head scanning direction of the recording head differs depending on each VTR. Therefore, when reproducing tapes recorded by different VTRs, this mounting step difference is taken into consideration. It is necessary to detect the track deviation of the playhead,
It is necessary to follow the track bending after obtaining the relative positional relationship between the recording position of the horizontal synchronizing signal on the recording tracks recorded by different recording heads and the head mounting position of the reproducing pair head. FIG. 6 shows the relationship between the time difference between the recording tracks recorded by the recording heads having different mounting steps and the reproduced horizontal synchronizing signal. FIGS. 9A and 9B show horizontal synchronizing signals 603 recorded on recording tracks by different recording heads. 6C and 6D show the output timing of the horizontal synchronizing signal reproduced from each head when the recording tracks shown in FIGS. 9A and 9B are reproduced and scanned by the same reproducing pair head 602.

The recording tracks shown in FIGS. 6A and 6B are recorded by recording pair heads having head steps H1 and H2, respectively, and are recorded on recording tracks A1, B1 and A2, B2. The recording position of the horizontal synchronizing signal 603 has steps H1 and H2. When the reproducing pair head 602 performs on-track reproduction scanning on such a recording track, each head A of the reproducing pair head 602,
The output timing of the horizontal synchronizing signal output from B is as shown in FIGS. 6C and 6D, respectively, and the reproduction time difference when the recording tracks A1 and B1 are scanned on-track is T1, while the recording The reproduction time difference when the tracks A2 and B2 are scanned on-track is T2. That is, even if the reproducing pair head scans the same on-track position, the time difference between the reproduced horizontal synchronizing signal and the reproducing horizontal head is different depending on the relationship between the recorded horizontal synchronizing signal and the mounting step of the reproducing pair head. In order to scan the position, the recording heads are different, and it is necessary to set the tracking reference values corresponding to the differences in the horizontal synchronizing signals recorded on the recording tracks.

In order to perform the track bending follow-up operation, piezo drive data for driving the electro-mechanical conversion element is calculated so that the time difference between the horizontal synchronizing signals output from the respective reproducing heads approaches the above tracking reference value. When there are tracks recorded by different VTRs on the same tape, the reproduction time difference of the horizontal sync signal at the on-track position changes before and after the editing point, as described above.
When the follow-up operation is performed without resetting the tracking reference value, the time difference of the horizontal sync signal reproduced when a track with a different recording position of the horizontal sync signal is first scanned is unidirectional with respect to the tracking reference value. The state is shifted to.
Therefore, the piezo drive data for driving the electro-mechanical conversion element is entirely processed in the same direction. This is equivalent to a state in which a DC voltage component is applied to the electro-mechanical conversion element, and when scanning tracks recorded with different VTRs on the same tape, it is possible to monitor the DC voltage component applied to the electro-mechanical conversion element. Can be detected.

FIG. 4 is a block diagram showing a schematic configuration of a tracking control device using the azimuth time difference detection method. In FIG. 4, 401 and 402 are reproduction pair heads having different azimuth angles, and 403 is a reproduction pair head 40.
Electro-mechanical conversion element mounting 1,402, 404,4
Reference numeral 05 is a reproduction amplifier that amplifies a reproduction signal reproduced from the reproduction pair heads 401 and 402, and 406 is a reproduction signal processing circuit that processes the reproduction signals output from the reproduction amplifiers 404 and 405 and outputs a reproduction video signal from a terminal 407. And the horizontal synchronizing signals H-sync (A) and H-sync reproduced by the heads 401 and 402 of the pair head.
(B) is output. 408 is each head 40 of the pair head
Horizontal sync signal H-sync reproduced from 1, 402
(A), a time difference detection circuit for detecting the time difference between H-sync (B), 409 is a tracking reference value creation circuit using the time difference data when the reproduction output of the magnetic head 402 is maximum as a reference value for tracking, and 410 is a tracking reference value. A drive data calculation circuit 411 for calculating and creating piezo drive data for driving the electro-mechanical conversion element based on the tracking reference value output from the creation circuit 409 and the time difference data output from the time difference detection circuit 408 is driven. An electro-mechanical conversion element drive circuit for driving the electro-mechanical conversion element 403 with a voltage corresponding to the output of the data arithmetic circuit 410, 4
Reference numeral 12 is a DC component integration circuit for obtaining an integrated value of a DC voltage component included in the piezo drive data output from the drive data operation circuit 410, and 413 is a capstan phase control reference so that the output value of the DC component integration circuit approaches 0. A phase reference control circuit that sets a delay amount for delaying a signal and delays a capstan phase control reference signal according to the delay amount, 41.
Reference numeral 4 denotes a phase control circuit 415 that performs phase control so that the phase relationship between the capstan phase control reference signal delayed by the phase reference control circuit 413 and the reproduction control signal becomes a predetermined value, and outputs a phase control error signal. Is a speed control circuit for controlling the rotation speed of the capstan motor 417 to a predetermined value, and 416 mixes the phase control error signal output from the phase control circuit 414 with the speed control error signal output from the speed control circuit 415. , A capstan motor drive circuit for driving the capstan motor 417.

The operation of the conventional tracking control device using the azimuth time difference detection system configured as described above will be described below.

Reproduction signals reproduced by the reproduction pair heads 401 and 402 are input to reproduction amplifiers 404 and 405, amplified, and input to a reproduction signal processing circuit 406. The reproduction signal processing circuit 406 performs processing for extracting a horizontal synchronization signal from the reproduction signals reproduced by the heads of the reproduction pair heads 401 and 402, and outputs the horizontal synchronization signal H-sync (A),
The H-sync (B) is input to the time difference detection circuit 408. The time difference detection circuit 408 detects the reproduction time difference between the input horizontal synchronization signals H-sync (A) and H-sync (B) and outputs the reproduction time difference data. In the tracking reference value creation circuit 409, the reproduction time difference data when the reproduction output of the reproduction head 402 becomes maximum is used as the reference value for the track bending follow-up control. The drive data calculation circuit 410 is input with the tracking reference value output from the tracking reference value creation circuit 409 and the time difference data output from the time difference detection circuit 408.
Piezo drive data for driving the mechanical conversion element 403 is calculated and created. The electro-mechanical conversion element drive circuit 411 drives the electro-mechanical conversion element 403 with a voltage corresponding to the piezo drive data. The piezo drive data created by the drive data calculation circuit 410 is input to the DC component integration circuit 412. The DC component integration circuit 412 finds the difference between the input piezo drive data and the piezo drive data when the DC voltage component applied to the electro-mechanical conversion element corresponds to 0 [v], and the difference value is predetermined. Perform integral calculation over a period. The phase reference control circuit 413 sets a delay amount for delaying the reference signal of the capstan phase control so that the integrated value which is the output of the DC component integration circuit 412 approaches 0, and is input from the terminal 418 according to the delay amount. Delays the reference signal for capstan phase control. The phase control circuit 414 performs phase control such that the delayed capstan phase control reference signal output from the phase reference control circuit 413 and the reproduction control signal input from the terminal 419 have a predetermined value. Outputs a control error signal. The speed control circuit 415 performs speed control so that the rotation speed of the capstan motor becomes a predetermined value, and outputs a speed control error signal. The capstan motor drive circuit 416 mixes the phase control error signal output from the phase control circuit 414 and the speed control error signal output from the speed control circuit 415 to drive the capstan motor 417.

[0013]

However, in the above-mentioned conventional structure, the horizontal synchronizing signals H-sync (A) and H-sync reproduced from each reproducing head of the pair head.
Piezo drive data is created based on the reproduction time difference data of (B), and the voltage corresponding to the piezo drive data is electrically
The reproducing head is displaced to the on-track scanning position by applying it to the mechanical conversion element, and at the same time, the DC voltage component applied to the electro-mechanical conversion element is obtained based on the piezo drive data, and the average applied voltage is 0 [v By changing the phase difference between the phase control reference signal of the capstan motor and the playback control signal in order to approach the above, interference of two loops that control the scanning position of the playback head occurs, and the scanning position of the playback head is constantly delicate. The deviation from the on-track position may occur, and this deviation cannot be ignored during narrow track recording. As a result, the DC voltage component applied to the electro-mechanical conversion element is near 0 [v], and the reproducing head is There is a problem that the off-track state continues for a long time before scanning the on-track position.

Further, when a single tape is continuously reproduced, the recording VTR is changed from the middle of the tape, and the tracking reference value is not changed when the positional relationship of the horizontal synchronizing signals recorded on the recording tracks is changed. If the tracking control is continued in this state, there is a problem that the electromechanical conversion element is controlled with the scanning position deviated from the on-track position as the reference scanning position, and the change in the recording head is automatically detected Then, it is necessary to re-obtain the tracking reference value.

The present invention solves the above-mentioned problems. When the DC voltage component included in the drive data created for driving the electro-mechanical conversion element is outside the predetermined range, the drive data is created. Provided is a tracking control device for a magnetic recording / reproducing device, which judges that the reference value of the tracking control used for the above is not an optimum value and resets the reference value, thereby significantly shortening the time of the off-track state. The purpose is to

[0016]

In order to achieve this object, a tracking controller of a magnetic recording / reproducing apparatus of the present invention has at least two parallel recordings simultaneously recorded on a magnetic recording medium by magnetic heads having different azimuth angles. In an apparatus for reproducing a recording track, at least two reproducing heads having different azimuth angles mounted on an electro-mechanical conversion element simultaneously scan the magnetic tape and reproduce, and a reproduction time difference of a specific signal included in each reproduction signal. To obtain a time difference detection means, a tracking reference value creation means for creating a reference value for tracking control, and at least to drive the electro-mechanical conversion element so that the difference between the reproduction time difference and the reference value is minimized. Drive data calculation means for outputting drive data, and drive the electromechanical conversion element according to the drive data Pneumatic-mechanical conversion element driving means, DC component integrating means for integrating a DC voltage component included in the drive data, and a detection signal for resetting the reference value from the output value of the DC component integrating means. The detection signal generating means has a phase reference control means for delaying the phase reference signal of the capstan motor so that the output value of the DC component integrating means approaches 0, and the detection signal generating means has the DC component integrating means. It comprises comparison means for comparing the output value of the means with a predetermined value, and addition operation means for creating the detection signal according to the output value of the comparison means.

[0017]

According to the present invention, with the above configuration, it is determined whether the integrated value of the DC voltage component included in the drive data created based on the reference value is within the predetermined range. By resetting the reference value for creating the data, the drive data can be created under the optimum reference value. When it is within the predetermined range, the integrated value of the DC voltage component included in the drive data By changing the phase difference between the phase reference signal of the capstan motor and the reproduction control signal so as to approach 0, it is possible to greatly reduce the time during which the reproducing head is in the off-track state when performing on-track scanning. The tracking control operation can be performed in a short time.

[0018]

1 is a block diagram of a tracking controller for a magnetic recording / reproducing apparatus according to a first embodiment of the present invention. In FIG. 1, magnetic heads 101, 102
Have different azimuth angles, and the electromechanical conversion element 1
It will be installed on the 03. 104 and 105 are magnetic heads 10.
A reproduction amplifier 106 that amplifies a reproduction signal output from each of the reproduction signals 101 and 102 is a reproduction signal processing circuit that processes the reproduction signal. The reproduction amplifier 106 outputs a reproduction video signal from a terminal 107 and outputs horizontal signals reproduced by the heads of the reproduction heads 101 and 102. The synchronization signals H-sync (A) and H-sync (B) are output. The output horizontal synchronizing signals H-sync (A), H-
The sync (B) is input to the time difference detection circuit 108, and in the time difference detection circuit 108, the horizontal synchronization signal H-sync.
The time difference between (A) and H-sync (B) is detected. The time difference data output from the time difference detection circuit 108 is input to the drive data calculation circuit 110 and the tracking reference value creation circuit 109. Tracking reference value creation circuit 10
In No. 9, the time difference data of the time difference detection circuit 108 when the reproduction output of the reproduction head 102 becomes maximum is used as the reference value of the tracking control and is input to the drive data calculation circuit 110. In the drive data arithmetic circuit 110, the reproducing pair head 10
Piezoelectric drive data for driving the electro-mechanical conversion element 103 is calculated based on the time difference data and the tracking reference value so that 1 and 102 scan the on-track position. The piezoelectric drive data calculated by the drive data calculation circuit 110 is the electro-mechanical conversion element drive circuit 1
11 is input. Electro-mechanical conversion element drive circuit 111
Then, a voltage corresponding to the piezo drive data is applied to the electromechanical conversion element 103 to drive it. Further, the piezo drive data calculated by the drive data calculation circuit 110 is input to the DC component integration circuit 112, and the piezo drive data and the electric
The difference from the piezoelectric drive data when the voltage applied to the mechanical conversion element is 0 [v] is integrated for a predetermined period, and the integration result is detected signal creation circuit 113 and phase reference control circuit 1
Enter in 15. The detection signal generation circuit 113 determines whether or not the integration result output from the DC component integration circuit 112 is within a predetermined range. It is input to the reference value creation circuit 109. The tracking reference value generation circuit 109 resets the tracking reference value to an optimum value when the detection signal 114 is input. In the phase reference control circuit 115, the DC component integration circuit 11
The delay amount for delaying the reference signal of the capstan phase control is set so that the integration result which is the output of 2 approaches 0, and the reference signal is delayed according to the delay amount. The phase control circuit 116 performs phase control so that the phase difference between the delayed reference signal output from the phase reference control circuit 115 and the reproduction control signal becomes a predetermined value, and outputs a phase control error signal. The speed control circuit 117 performs speed control so that the rotation speed of the capstan motor 119 becomes a predetermined value, and outputs a speed control error signal. The capstan motor drive circuit 118 mixes the phase control error signal output from the phase control circuit 116 and the speed control error signal output from the speed control circuit 117 to drive the capstan motor 119.

FIG. 2 shows a block diagram of the DC component integrating circuit 112, the detection signal generating circuit 113, and the phase reference control circuit 115. The direct-current component integration circuit 112 includes the difference calculation circuit 20.
3 and an integration circuit 204 that integrates the output data of the difference calculation circuit 203 for a predetermined period. Difference calculation circuit 20
3, the piezoelectric drive data input from the terminal 201 and the piezoelectric drive data (x ′) corresponding to the voltage applied to the electro-mechanical conversion element input from the terminal 202 are 0 [v].
80 ') is calculated and integrated by the integrating circuit 204 for a predetermined period. The integration result is input to the detection signal creation circuit 113 and the phase reference control circuit 115. Detection signal generation circuit 11
3 is a comparison circuit 207, 208 and OR gate circuit 20
It is composed of 9. The integration result which is the output of the DC component integration circuit 112 is input to the comparison circuits 207 and 208 and is input to the terminal 20.
Predetermined set values (C, D; C <
D). The comparison result is input to the OR gate circuit 209, and the detection signal 114 indicating whether to reset the tracking reference value is output from the terminal 209 to the tracking reference value creation circuit 109. That is, when the integration result E which is the output of the DC component integration circuit 112 is C ≦ E ≦ D, the detection signal 114 outputs a low level, and E <C or D <
When it is E, the high-level detection signal 114 is output. The tracking reference value creation circuit 109 resets the tracking reference value when the high-level detection signal 114 is input. The phase reference control circuit 115 changes the delay amount of the phase reference signal of the capstan motor so that the integration result, which is the output of the DC component integration circuit 112, is close to zero.

FIG. 3 shows an operation waveform diagram in the first embodiment of the present invention. In FIG. 3, (a) is an H-SW signal indicating the head scanning position. (B) shows piezo drive data for driving the electro-mechanical conversion element 103,
(C) shows the integrated data output from the DC component integrating circuit 112, (d) shows the detection signal 114 output from the detection signal creating circuit 113, and (e) shows the delay amount of the phase reference signal of the capstan motor. Indicates the delay data to be set. Sections 2 and 7 are the operation when the track bending follow-up operation is stopped, and the other sections show the operation when the track bend follow-up operation is being performed.

First, in section 1, the integration result E ((c) in the figure) output from the DC component integration circuit 112 is D <
Since E (D is a predetermined value), the detection signal creation circuit 113 detection signal 114 is output at a high level in the section 2,
It is input to the tracking reference value creation circuit 109. The tracking reference value creation circuit 109 creates the piezo drive data shown in FIG. 9B to reset the tracking reference value, and outputs it from the drive data calculation circuit 110. At this time, the integration result ((c) in the figure) which is the output of the DC component integration circuit 112 is set to zero. In section 3, the detection signal creation circuit 113 outputs a low-level detection signal 114 ((d) in the figure) to start the track bending follow-up operation. Since the integration result E that is the output of the DC component integration circuit 112 is E <D (D is a predetermined value), the integration result E that is the output of the DC component integration circuit 112 should be close to 0 in sections 4 and 5. The delay data ((e) in the figure) for setting the delay amount of the phase reference signal of the capstan motor is slightly changed. Therefore, the piezo drive data is controlled to be in the vicinity of x'80 'as shown in FIG. Section 6
When the piezo drive data largely changes with respect to x′80 ′ as shown in FIG. 7B due to the influence of disturbance or the edit point at the time of recording, the integration result E which is the output of the DC component integrating circuit 112 is Since D <E (D is a predetermined value),
In the section 7, the detection signal generation circuit 113 outputs the high level detection signal 114. Drive data arithmetic circuit 110
Outputs the piezo drive data shown in FIG. 9B and resets the tracking reference value. In section 8, the track bending follow operation is started again, and the piezo drive data is x'8.
Tracking control is performed by changing the delay amount of the phase reference signal of the capstan motor so that it changes in the vicinity of 0 '.

As described above, according to this embodiment, in the tracking control using the azimuth time difference, the detection signal creating circuit 113 determines that the integrated value of the DC voltage component included in the piezo drive data is out of the predetermined range. If so, the tracking reference value is reset, and if it is determined that the integrated value is within the predetermined range, the integrated value of the DC voltage component applied to the electromechanical conversion element is set to 0 [v]. By changing the phase difference between the phase reference signal of the capstan motor and the reproduction control signal, stable tracking control can be performed in a short time. Although H-sync is used as the specific signal, the control operation can be performed using other synchronization signals (for example, ID data in the D-VTR and a signal for detecting switching of blocks).

[0023]

As described above, according to the present invention, a predetermined range is set in the detection signal generating circuit 113, and the integrated value of the DC voltage component applied to the electromechanical conversion element is out of the predetermined range. In this case, the tracking reference value serving as the reference for tracking control is reset, and if it is within the predetermined range, the integral value of the DC voltage component applied to the electromechanical conversion element is 0.
By changing the phase difference between the phase reference signal of the capstan motor and the reproduction control signal so as to be close to [v], even if the tracking reference value indicating the on-track position due to the pattern change of the recording track such as the editing point changes. By detecting this and resetting the tracking reference value, the time to enter the off-track state can be greatly shortened and stable tracking control can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram of a tracking controller of a magnetic recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a DC component integrating circuit, a detection signal generating circuit, and a phase reference control circuit of the same embodiment.

FIG. 3 is an operation waveform diagram for explaining the operation of the embodiment.

FIG. 4 is a block diagram of a tracking control device using a conventional azimuth time difference detection method.

FIG. 5 is a schematic diagram and a waveform diagram for explaining a conventional azimuth time difference detection method.

FIG. 6 is a schematic diagram and a waveform diagram for explaining a conventional azimuth time difference detection method.

[Explanation of symbols]

 108 time difference detection circuit 109 tracking reference value creation circuit 110 drive data calculation circuit 112 DC component integration circuit 113 detection signal creation circuit 114 detection signal 115 phase reference control circuit 205 predetermined value input terminal 206 predetermined value input terminal 207 comparison circuit 208 comparison circuit 209 OR gate circuit

Claims (1)

Claim: What is claimed is: 1. An apparatus for reproducing at least two parallel recording tracks simultaneously recorded on a magnetic recording medium with magnetic heads having different azimuth angles, which is mounted on an electro-mechanical conversion element. At least 2 with different azimuth angles
A time difference detecting means for obtaining a reproduction time difference of a specific signal included in each reproduction signal reproduced by the reproducing heads simultaneously scanning the magnetic tape; a tracking reference value generating means for generating a reference value for tracking control; A drive data calculating means for outputting drive data for driving the electro-mechanical conversion element so that the difference between the reproduction time difference and the reference value is minimized; and the electro-mechanical conversion element according to the drive data. An electro-mechanical conversion element driving unit for driving, a DC component integrating unit for integrating a DC voltage component included in the driving data, and a detection signal for resetting the reference value from the output value of the DC component integrating unit. Phase reference control for delaying the phase reference signal of the capstan motor so that the output value of the detection signal creation means to be created and the direct current component integration means approaches 0. The detection signal creating means includes a comparing means for comparing the output value of the DC component integrating means with a predetermined value, and an addition operation for creating the detection signal according to the output value of the comparing means. Means for resetting the reference value when the output value of the DC component integrating means is out of a predetermined range.