JPH1032779A - Tracking controller and magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably perform tracking shift over a wide range. SOLUTION: Tracking error data from a head 1a provided by a tracking error detection part 52 of a microcomputer 5 are amplified with a gain set by a total control part 60 through an amplifier part 55 and inputted through a memory 58 to an adder part 59. The tracking error data from a head 1b provided by the tracking error detection part 52 are amplified with the gain set by the total control part 60 through amplifier parts 56 and 57, inputted to the adder part 59 and added but the total control part 60 turns that added value to '0' and sets the gain corresponding to tracking shift data K applied separately to the amplifier parts 55 and 57. Thus, the tracking error data can be turned to the value corresponding to the shift data K by the amplifier part 55 or 57 in the area where the tracking error data are saturated, and tracking shift can be performed even in this saturated area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus for performing tracking control using a pilot signal.
In particular, it relates to a tracking control device having a tracking shift function.

[0002]

2. Description of the Related Art Conventionally, a tracking control device (ATF) using a pilot signal includes an 8 mm VTR using a pilot signal of four frequencies, a 6 mm digital VTR using a pilot signal of two frequencies, and the like. It has been implemented. The tracking method using such a pilot signal is also a so-called auto tracking method.

The tracking shift by the tracking control device may occur when checking the shape of a reproduced signal at the time of adjusting a tape traveling system in a manufacturing process of a magnetic recording / reproducing device, or when reproducing a tape recorded by another device. It is used to recover data loss due to a certain track bend. Hereinafter, a tracking shift method using a conventional tracking control device will be described.

FIG. 12 is a block diagram showing a configuration example of a conventional tracking shift control device using two-frequency pilot signals. As the pilot signal, there is a signal having two kinds of frequencies of fl and f2. As shown in FIG. 13, on the magnetic tape 600, an f0 track not including a pilot signal and an f0 track including an f1 frequency pilot signal are included.
A track is formed by four-track circulation of one track, f0 track, and f2 track including a pilot signal of f2 frequency. Here, in the drawing, T1 to T7 are track numbers given for explanation.

The signal reproduced from the head 1 shown in FIG. 12 is amplified by a preamplifier 2 and a band-pass filter (B
The pilot signals fl and f2 are extracted by the PF) 3, and “f2−f1” is DC-detected by the difference detector 4 and output. This difference detector 4 outputs a DC level of Vcc / 2 when the output difference is "0". The microcomputer 5 converts the DC value into an A / D converter 5
A / D (Vcc (3V) / 256 bits) is converted into digital data by 1 and the tracking error extracting unit 52 calculates the difference between the digital data and the center value (128) which is Vcc / 2, thereby obtaining a tracking error value. .

At this time, when the head 1 is at the position of the T2 track in FIG. 13, the tracking error extraction unit 52 calculates "input data -128". Since the relationship of the tracks to be executed is opposite to that at the time of the T2 track, “128-input data” is calculated. The obtained tracking error value is A
The level is adjusted to a certain level by the GC 53 to become data a, which is added to the shift data b by the adder 59, and the data c becomes the final tracking error value. Tracking control is performed by adjusting the rotation phase of the capstan.

FIG. 14 shows the relationship between the shift position (horizontal axis), the tracking error value a, and the shift data b.
For example, if “b = 10”, the tracking shifts to a position where “a = −10” before the data c becomes 0. When not shifting, "b =
If “0” is set, “a = 0” is drawn, and there is no tracking shift.

Here, the conventional problems will be described.
As shown in FIG. 14, the tracking error value “a” for the tracking shift position is saturated before one track. The fact that the signal is saturated means that all the pilot signals of the fl or f2 tracks of the adjacent track are reproduced. In the case of this figure, the saturation occurs at a half track, but where the saturation occurs is determined by the amount of protrusion of the head width of the head 1 with respect to the track pitch and the amount of fringing reproduced from both ends of the head. For example, for a track pitch of 10 μm, a head width of 1
Assuming that the protrusion amount is 5 μm, the protruding amount is 2.5 μm on one side, and the reproducing fringing amount is 2.5 μm on one side, reproduction is performed at +5 μm on one side with respect to a track pitch of 10 μm. At the position, a pilot signal for the next track 10 μm has already been reproduced.

Here, if the tracking error value is saturated as described above, the tracking error value “a” corresponding to the shift data “b” cannot be obtained, so that the tracking is not locked. For example, when “b = 75”, it shifts to shift to the position “a = −75”, but the tracking always flows because “−75” cannot be obtained. Therefore, the shiftable range is a range in which the tracking error value is not saturated.
Up to two tracks. If the shift range is narrow, adjustment of the traveling system of the magnetic recording / reproducing apparatus becomes extremely difficult, and the range of data recovery for track bending is narrowed.

[0010]

In the conventional tracking control device, the range in which the tracking shift can be performed is a range of ± 1/2 track as long as the tracking error value is not saturated, and the shift range is very narrow. If the shift range is narrow, adjustment of the traveling system of the magnetic recording / reproducing apparatus becomes extremely difficult, and the range in which data can be recovered from a track bend becomes narrow.

The present invention has been made in order to solve the above-mentioned problems, and it is easy to adjust the traveling system of a magnetic recording / reproducing apparatus by stably performing a tracking shift in a wide range. It is another object of the present invention to provide a tracking control device and a magnetic recording / reproducing device using the tracking control device capable of expanding a data recovery range for a track bend.

[0012]

According to a first aspect of the present invention, there is provided a magnetic tape in which a plurality of pilot signals having different frequencies are cyclically recorded in units of two tracks with a unit track having no pilot signal interposed therebetween. Reproducing means for driving and reproducing the pilot signal recorded on the magnetic tape by first and second rotary magnetic heads for simultaneously scanning two tracks, and a first rotary magnetic means for scanning the track on the magnetic tape; First signal generating means for generating a first tracking error signal using a pilot signal included in a signal reproduced by the head; and second signal scanning means for scanning an adjacent track scanned by the first rotating magnetic head. A second signal generating means for generating a second tracking error signal using a pilot signal included in a signal reproduced by the rotating magnetic head; And a ratio between a first tracking error signal generated by the first signal generating means and a second tracking error signal generated by the second signal generating means, which corresponds to a designated tracking shift amount. A third signal generating means for generating a third tracking error signal by adding at a level, and running of the tape running system such that the third tracking error signal generated by the third signal generating means becomes zero. And a control circuit for controlling the phase.

According to a second aspect of the present invention, the third signal generating means includes a first variable gain amplifier for amplifying the first tracking error signal generated by the first signal generating means, and a second signal. A second gain variable amplifying unit for amplifying the second tracking error signal created by the creating unit; and a gain determined by the separately designated tracking shift amount and a gain of the first gain variable amplifying unit and the second gain variable amplifying unit. Gain control means for setting the gain of the variable gain amplifier.

According to a third aspect of the present invention, there is provided a measuring means for measuring a maximum value of the first tracking error signal and a maximum value of the second tracking error signal, and measuring the maximum values measured by the measuring means. Level correcting means for correcting to the same level, wherein the third signal generating means uses the first tracking error signal or the second tracking error signal corrected by the level correcting means to perform the third tracking A configuration for generating an error signal is provided.

According to a fourth aspect of the present invention, the level correction means takes a ratio between the two maximum values measured by the measurement means, and an amplifier having a gain determined in accordance with the ratio provides the level correction value. One or both of the first tracking error signal and the second tracking error signal are amplified to correct the level of the first tracking error signal and the level of the second tracking error signal to the same level. It has a configuration.

According to a fifth aspect of the present invention, a detecting means for detecting a shift amount of the first or second tracking error signal, and the gain control means determines a gain corresponding to the shift amount detected by the detecting means. A configuration is provided in which the first or second variable gain amplifier is set for each tracking shift amount.

According to a sixth aspect of the present invention, the detecting means scans the tape running in the opposite direction to the normal running by the first or second head, and determines the first or second scanning direction based on the saturation characteristic of the obtained tracking error signal. 2 is provided for detecting a deviation amount of the tracking error signal.

According to a seventh aspect of the present invention, the gain control means includes:
It has in advance data that lists gains to be set in the first or second variable gain amplifying unit for each tracking shift amount corresponding to the deviation amount detected by the detection unit, and refers to this data. A configuration is provided in which a gain corresponding to the shift amount is set in the first or second variable gain amplifier for each tracking shift amount.

According to the present invention, there is provided a magnetic recording / reproducing apparatus for recording / reproducing information on / from a magnetic tape by a plurality of magnetic heads on a rotary cylinder.
A tracking control between the reproducing magnetic head and tracks on the magnetic tape is performed using the tracking control device described above.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the first embodiment of the tracking control device of the present invention. The magnetic head for recording / reproducing data can be applied to either two heads 180 degrees opposite to each other on the cylinder or four double azimuth heads. In this embodiment, the double azimuth head is used. A case will be described in which two tracks are simultaneously traced, and a double azimuth head for recording only and a double azimuth head 1a and 1b for reproduction are provided at a position 180 degrees opposite thereto.

Reference numerals 1a and 1b denote read-only double azimuth heads (heads) for simultaneously tracing two tracks.
Reference numerals a and 2b denote preamplifiers for independently amplifying the reproduced signals reproduced by the heads 1a and 1b, 3 a band-pass filter (BPF) for extracting pilot signals of frequencies f1 and f2 from the reproduced signals, and 4 a pilot of frequency f1. A difference detector 5 for subtracting the pilot signal of the frequency f2 from the signal to obtain a difference between the two pilot signals is a microcomputer that calculates a tracking control error and performs a track shift. An extracting unit 52, an automatic gain control unit (AGC) 53, a switching unit 54 for switching and outputting any one of the reproduced signal of the head 1a and the reproduced signal of the head 1b, and a variable gain for amplifying the reproduced signal of the head 1a. Amplifying section 55, an amplifying section 56 for correcting a difference in reproduction level between the head 1a and the head 1b, and a head b. A variable-gain amplifying section 57 for amplifying the reproduced signal b, a memory 58 for temporarily storing the signal output from the amplifying section 55, a readout signal from the memory 58 and a signal output from the amplifying section 57 are added. An adder 59 that outputs tracking error data, a general commander (gain control means) 60 that comprehensively controls the tracking error calculation process and the tracking shift operation, and the like are configured by software or the like. Reference numeral 6 denotes a switch for selecting and outputting one of the reproduction signal of the head 1a and the reproduction level of the head 1b.

Next, the operation of this embodiment will be described. The head 1a is a reproducing head for tracing the track f0 shown in FIG. 13 when there is no tracking shift, and the head 1b is a reproducing head for tracing the fl and f2 tracks when there is no tracking shift.
Reproduction signals are reproduced from the heads 1a and 1b at the same time, and are amplified by the preamplifiers 2a and 2b, respectively. The outputs of the preamplifiers 2a and 2b are selected by the switch 6 and input to the BPF 3. The BPF 3 extracts the signal band of the pilot signals f1 and f2, and outputs the pilot signal f1 or f2 or both pilot signals to the difference detector 4.
Is input to The switch 6 is switched to the L side or the H side by the control signal 30 output from the general command unit 60.

In the difference detector 4, "the pilot signal f2
The "pilot signal fl" is detected and output at the DC level, and is input to the microcomputer 5. In the microcomputer 5, an analog signal is first converted into digital data by the A / D converter 51. Here, it is assumed that the conversion is from Vcc (3v) to 256 bits. The conversion timing is controlled by a control signal 40 output from the general command unit 60. The difference between the digitized data and the Vcc / 2 data of 128 is calculated by the tracking error extraction unit 52, the level is adjusted to a constant level by the AGC unit 53, and the data is input to the switching unit 54. In the switching section 54, data is selected with the same polarity as that of the switch 6 by the control signal 30 output from the general command section 60, and when the control signal 30 from the general command section 60 is at a low level, the data becomes L side and the head 1a , A first tracking error signal created from the pilot signal reproduced from
Is amplified at the level specified by the general command unit 60 and input to the adding unit 59.

On the other hand, when the control signal 30 from the general command section 60 is at a high level, the switch 6 switches to the H side and selects the second tracking error signal created from the pilot signal reproduced from the head 1b. Amplifying part 5
6, where the output is input to an amplifier 57. The amplification section 57 amplifies the signal at the level specified by the general command section 60 and inputs the amplified signal to the addition section 59. However, the general command unit 60 amplifies the gain determined based on the tracking shift data K input from the outside.
In order to set them to 5, 57, the amplifying units 55, 57 amplify the first and second tracking error data with the set gain. The adder 59 adds the input first and second tracking error data, and outputs the obtained value to a tracking control circuit (not shown) as third tracking error data.

FIG. 2 is a timing chart for explaining the operation of the tracking control device. FIG.
(A) shows a switching pulse (SWP) for switching between the recording head and the reproducing head, and when it is at the high level, it is the timing when switching to the reproducing head. The control signal 30 is a control signal for the switch 6 and is shown in FIG.
As shown in the figure, the head 1a is selected at the time of the low level, and the head 1b is selected at the time of the high level.
Here, the head 1b is selected near the center of the track, but this position does not need to be specified, and it is sufficient to switch at least once in one track.

The signal thus switched is BP
In F3, the frequency bands of fl and f2 are extracted and input to the difference detector 4. Here, the fl pilot signal and f
Since the two pilot signals are respectively extracted, the difference detector 4 compares “the level of the f2 pilot signal−the level of the fl pilot signal”, and outputs the difference as a DC level as shown in FIG. 2C. This output is (f2
Pilot signal level-fl pilot signal level) =
When it is 0, it becomes Vcc / 2.

Therefore, while the tracking servo is locked, while the switching unit 6 is selecting the head 1, the output of the difference detector 4 is Vcc / 2 of the center value.
In the section where the switching pulse is at the high level and the control signal 30 is at the high level (f0, fl), during the head 1b selection period, the switch 6 switches the head 1b.
Select At this time, since the head 1b traces the center position of the fl track, the switch 6
1 outputs the maximum value of the pilot signal.
Outputs the minimum value of the f1 pilot signal. The output of the difference detector 4 is input to the A / D converter 51 of the microcomputer 5.

The switching pulse is in a high level section, and the control signal 50 is in a high level (f0, f).
2) While the head 1b in the section is selected, the switch 6 selects the head 1b.
Traces the center position of the f2 track, the switch 6 outputs the maximum value of the f2 pilot signal, and the difference detector 4 outputs the maximum value of the f2 pilot signal. The output of the difference detector 4 is input to the A / D converter 51 of the microcomputer 5.

The A / D converter 51 converts the input difference signal into a digital value at a sampling timing as shown in FIG. This sampling timing may be sampled once while selecting one head, or may be sampled multiple times.
Here, sampling is performed once. A / D converter 5
In the digital data obtained in step 1, the tracking error extracting unit 52 detects the difference from the center value of 128, and this output becomes the first or second tracking error value. This output is adjusted to a constant level by the AGC unit 53, whereby the level variation due to the variation of the output of the magnetic tape, the head output, and the amplification factors of the preamplifiers 2a and 2b is adjusted.

FIG. 3 shows a tracking shift position (horizontal axis).
FIG. 4 is a diagram showing a relationship between a head tracking error P created from outputs of a head 1a and a head 1b and a head 2 tracking error Q. Here, the maximum value (saturation point) data of the tracking error P of the head 1a is 50,
The maximum value (saturation point) of the tracking error Q of b is 7
It is set to 0.

The reason why the maximum value of the tracking error of the head 1b is larger than the tracking error of the head 1a is that the azimuth angle of the head 1b is the same as that of the tracks f1 and f2. This is because the effect is expressed as a level difference because the angle is as large as 20 degrees. Therefore, the amplifier 56 shown in FIG. 1 corrects this difference. The tracking error of the head 1b is input to the amplifying unit 56, and the maximum level thereof is amplified (here, 50/70 times) so as to be the same level as the tracking error of the head 1b, and this is indicated by the broken line in FIG. This is a tracking error R obtained from the reproduction signal of the head 2. Of course, the level of the tracking error P of the head 1b may be amplified to match the level with the tracking error Q of the head 1b. The first, obtained from the reproduced signals of the heads 1a and 1b whose levels have been adjusted,
The second tracking error data is input to the amplifier 55 and the amplifier 57, respectively. The gains of the two amplifying units are set in accordance with the position where the tracking shift data K, which is separately input by the general command unit 60, indicates that a tracking shift is to be performed.

Here, assuming that one track is divided into 100 steps at the tracking shift position, the gain of the amplifying section 55 and the amplifying section 57 for the tracking shift data K is adjusted by the general command section 60 as shown in FIG. Is set. When normal tracking shift is not performed, “K =
4, the gain of the amplifier 55 is 1 and the gain of the amplifier 57 is 0, as shown in FIG.
9 is only the first tracking error data input from the amplifying unit 55 via the memory 58, so that the tape running system (not shown) performs tracking with this tracking error data, which is the same as the conventional method. It is.

Further, when shifting by +2/10 track, "K = 10 × 2/10 = 20", so the amplifying section 55 is 1 and the amplifying section 57 is "-20/50" from FIG.
Is set to Also, in the 1/2 track shift, "K =
4, the amplifying unit 55 is 1 × and the amplifying unit 57 is −1 ×, so that the subtraction is performed on a one-to-one basis, and the adding unit 59 is gain-adjusted by the amplifying units 55 and 57. The first and second tracking error data are added, and the third tracking error data is output to a tape running system (not shown).

FIG. 5 is a diagram showing outputs of the amplifiers 55 and 57 with respect to the tracking shift data K (horizontal axis). A, B, and C indicate the levels of the tracking error data output from the amplifier 57, D, E, and F indicate the levels of the tracking error data output from the amplifier 55. H and C indicate the levels of the tracking error data output from the amplifying unit 56.
E and R indicate the levels of the tracking error data output from the amplifier 56.

For example, in the case of a tracking shift of -1/2 to +1/2, the level of the tracking error data output from the amplifying section 55 is E, and the level of the tracking error data output from the amplifying section 57 is B. During this time, the two tracking error data become symmetrical with respect to the shift data K axis and become 0 when added by the adder 59. Therefore, when the tracking is locked, the tracking is shifted to the designated tracking shift point at that time. Will be. If the tracking shift is +1/2 to +1, the level of the tracking error data output from the amplifier 55 becomes F, and the level of the tracking error data output from the amplifier 57 becomes C. Since the data is symmetrical with respect to the shift data K axis and becomes 0 when added by the adder 59, when the tracking is locked, the tracking is shifted to the tracking shift point designated at that time.

According to the present embodiment, the first head tracking error data generated from the reproduction signal reproduced by the head 1a and the second head tracking error data generated from the reproduction signal reproduced by the head 1b are combined. Amplification is performed by the amplifying unit 55 and the amplifying unit 57 having a gain set corresponding to the tracking shift data K, so that the level of the region where the first and second head tracking error data are saturated is lowered. Moreover, the first and second head tracking error data with the gain adjusted are added to the adder 5.
By performing tracking control so that the third tracking error data obtained by adding in step 9 becomes 0,
The region where the first and second head tracking error signals are saturated can also be used, and the tracking shift from −1 to +1 can be performed stably, so that the tracking shift can be performed over a wide range. This makes it easy to adjust the traveling system of the magnetic recording / reproducing apparatus, and also expands the data recovery range with respect to track bending.

FIG. 6 is a block diagram showing an example of a configuration for determining the gain of the amplifying section 56 for correcting the difference in reproduction level between the head 1a and the head 1b. The output of the switching unit 54 of the microcomputer 5 is connected to the switching unit 61. The switching unit 61 is switched by the control signal 50 output from the general command unit 60 in a span sufficiently longer than the switching timing of the switching unit 54. When the switching unit 61 selects the H side (normal reproduction) and when the switching unit 54 selects the L side, the tracking error data generated from the reproduction signal from the head 1a is used for tape running (not shown). The signal is output to the system and tracking control is performed. When the switching unit 61 is on the H side and the switching unit 54 is selecting the H side, the switching unit 54
From the time when the tracking error data generated from the reproduction signal from the head 1a is being output, and this tracking error data indicates the maximum value of the tracking error data obtained from the head 1a. The calculation is taken into the calculation unit 62.

On the other hand, when the switching section 61 is on the L side, the general command section 60 switches so as to perform tracking control with a tracking error signal generated from the reproduced signal from the head 1b, so that the head 1b traces the f0 track. , The head 1a traces the fl and f2 tracks. Accordingly, the tracking error data generated by the reproduction signal from the head 1a indicates the maximum value obtained from the head, and this maximum value is calculated by the ratio calculation unit 62.
It is taken in. When the two types of data are taken in, the ratio calculation unit 62 calculates the ratio between the two maximum values. For example, as shown in FIG. 3, if the maximum value of the head 1b is 70 and the maximum value of the head 1a is 50, This ratio is 50/70. This ratio is stored in the memory 7 outside or inside the microcomputer 5, and when performing normal tracking control,
The gain of the amplification unit 56 shown in FIG. 1 is set by the general command unit 60 according to the ratio stored in the memory 7.

FIG. 7 is a block diagram showing a second embodiment of the tracking control device of the present invention. This example is shown in FIG.
Is an example of a device having a function for determining the gain of the amplifying unit for correcting the difference in the reproduction level of the head shown in FIG. 1, and has a configuration in which the device shown in FIG. Under the control of the general command unit 60, the switch SW is switched to a normal reproduction mode and a mode for correcting a reproduction level difference of the head.
1. It is configured to be switched by switching the switch SW2. That is, the general command section 60 switches the switches SW1 and SW2 to the terminal a during normal reproduction, and
SW1 and SW2 to correct the difference in head playback level
To the terminal b side. The operation in each mode is the same as the operation described in FIG. 1 or FIG. This allows
By setting the gain of the amplifier 56 in each device, it is possible to correct the difference in the reproduction level of the head optimal for the device.

FIG. 8 is a characteristic diagram showing the relationship between the tracking shift position and the tracking error data for explaining the third embodiment of the tracking control device of the present invention. As described above, the saturation points of the first tracking error data reproduced from the head 1a and the second tracking error data reproduced from the head 1b with respect to the tracking position change due to the head width and the reproducing fringing of the head. , There is a possibility that it varies from head to head.
The figure shows the relationship when the saturation point varies after 1/2 track, and the first tracking error data is +
It is slightly off to the side. In such a case, if the gain shown in FIG. 4 is set in the amplifying unit 55 and the amplifying unit 57 and the tracking shift is performed, the gain is drawn to a position slightly shifted from a desired position.

Therefore, in order to measure the variation of the saturation point as shown in FIG.
The tracking control is performed at double speed, and the head 1a is caused to scan over the track as shown in FIG.
A head switching pulse (SW) as shown in FIG.
For P), a tracking error data characteristic as shown in FIG. 10B is obtained, and a relationship as shown in FIG. 8 is estimated from the tracking error data characteristic to detect a deviation of the saturation point. The general command unit 60 selects the optimum one from the gain data as shown in FIG. 4 for each preset deviation of the saturation point from the detected deviation of the saturation point, and uses this data to amplify the amplification unit 55, By setting the gain of the amplifying section 57, even if the above-mentioned saturation point is deviated, tracking error data which becomes 0 when added by the adding section 59 is obtained. Incidentally, the gain data for the deviation of the saturation point can be calculated from the deviation of the saturation point.

FIG. 11 is a block diagram showing an embodiment of the magnetic recording / reproducing apparatus of the present invention. Magnetic tape 600
Is run by the tape running system 70. The tape running system 70 includes a motor speed controller 71, a motor drive amplifier 72, a motor driver 73, a motor 74 for driving a capstan or a reel, a frequency generator 75, and an FG amplifying / shaping circuit 76.

The reproduced signals reproduced by the heads 1a and 1b are input to a reproduced video signal processing section 81 and subjected to various processes, thereby being output as reproduced video signals, and
Tracking control device 80 as shown in FIG. 1 or FIG.
Is input to Since the tracking control device 80 outputs a tracking error signal to the motor speed control device 71 of the tape running system 70, the motor speed control device 71 controls the rotation phase of the motor 74 so that the tracking error signal becomes zero. By performing tracking control, a tracking shift corresponding to the tracking shift data K is performed.

The tracking control device 80 of the present embodiment can shift the tracking shift data K by ± 1 track, so that the data recovery performance against the track bending at the time of other recording reproduction is improved, and the tape running system is improved. 70 can be easily adjusted, and the operability can be improved.

[0045]

As described above, according to the first and second aspects of the present invention, by using the region where the tracking error signal is saturated at different levels, the tracking shift can be stably performed in a wide range. As a result, the traveling system of the magnetic recording / reproducing apparatus can be easily adjusted, and the data recovery range for track bending can be widened.

According to the third and fourth aspects of the present invention, the first and second
Even if there is a difference in the reproduction level between the heads, the tracking shift having the above effect can be performed.

According to the fifth, sixth and seventh aspects of the present invention, even if the saturation point of the first or second tracking error data is shifted, the tracking shift having the above effect can be performed smoothly.

According to the eighth aspect of the present invention, it is possible to improve the data recovery ability for the track bending, to easily adjust the tape running system, and to improve the operability.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a tracking control device according to a first embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation of the device shown in FIG.

FIG. 3 is a diagram showing a reproduction level difference between two tracking error signals.

FIG. 4 is a table showing a relationship between a gain and a tracking shift range set by the general command unit shown in FIG. 1 in the amplification unit.

FIG. 5 is a characteristic diagram showing a level change with respect to tracking shift data of a tracking error signal added by the adding unit shown in FIG. 1;

FIG. 6 is a block diagram showing a configuration example for determining a gain of an amplifying unit for correcting a reproduction level difference between two heads.

FIG. 7 is a block diagram showing a configuration of a second embodiment of the tracking control device of the present invention.

FIG. 8 is a characteristic diagram showing a relationship between a tracking shift position and tracking error data for explaining a third embodiment of the tracking control device of the present invention.

FIG. 9 is an explanatory diagram showing a method of head tracing for obtaining the characteristic diagram shown in FIG. 8;

10 is a level change waveform chart of head tracking error data obtained by the head tracing method shown in FIG. 9;

FIG. 11 is a block diagram showing an embodiment of the magnetic recording / reproducing apparatus of the present invention.

FIG. 12 is a block diagram showing a configuration example of a conventional tracking control device.

FIG. 13 is a diagram showing an example of an arrangement of tracks formed on a magnetic tape.

FIG. 14 is a characteristic diagram showing a relationship between a tracking shift position and a tracking error signal.

[Explanation of symbols]

 1a, 1b head 2a, 2b preamplifier 3 bandpass filter 4 difference detector 5 microcomputer 6 switcher 7, 58 memory 51 A / D converter 52 tracking error extractor 53 automatic gain Control units 54, 61 Switching units 55, 56, 57 Amplifying units 59 Addition units 60 General command units 62 Ratio calculating units SW1, SW2 Switches

Claims (8)

[Claims] 1. A magnetic tape on which a plurality of pilot signals having different frequencies are cyclically recorded in a unit of two tracks with a unit track having no pilot signal interposed therebetween, and the pilot signals are recorded on the magnetic tape. First and second scanning of the pilot signal simultaneously on two tracks each
A reproducing means for reproducing with a rotating magnetic head; and a first means for generating a first tracking error signal using a pilot signal included in a signal reproduced by a first rotating magnetic head for scanning a track on the magnetic tape. And a second tracking error signal is created using a pilot signal included in a signal reproduced by a second rotating magnetic head that scans an adjacent track scanned by the first rotating magnetic head. A second signal creating means, and a designated tracking shift between the first tracking error signal created by the first signal creating means and the second tracking error signal created by the second signal creating means. Add at the level of the ratio corresponding to the quantity
A third signal creating means for creating a tracking error signal of the following; a control circuit for controlling the running phase of the tape running system so that the third tracking error signal created by the third signal creating means becomes 0; A tracking control device comprising: 2. The signal processing device according to claim 1, wherein the third signal generation unit is a first variable gain amplifier that amplifies the first tracking error signal generated by the first signal generation unit, and is generated by the second signal generation unit. A second variable gain amplifier for amplifying the second tracking error signal, and a gain of the first variable gain amplifier and a gain of the second variable gain amplifier determined by a separately determined tracking shift amount. 2. The tracking control device according to claim 1, further comprising gain control means for setting a gain. 3. A measuring means for measuring a maximum value of the first tracking error signal and a maximum value of the second tracking error signal; and correcting the two maximum values measured by the measuring means to the same level. Level correcting means, wherein the third signal generating means generates the third tracking error signal using the first tracking error signal or the second tracking error signal corrected by the level correcting means. The tracking control device according to claim 1 or 2, wherein: 4. The level correction means calculates a ratio between the two maximum values measured by the measurement means, and an amplifying unit having a gain determined in accordance with the ratio calculates the first tracking error signal. Alternatively, one or both of the second tracking error signals are amplified, and the level of the first tracking error signal and the level of the second tracking error signal are corrected to the same level. The tracking control device according to claim 3. 5. A detecting means for detecting a shift amount of the first or second tracking error signal, and the gain control means sets a gain corresponding to the shift amount detected by the detecting means for each of the tracking shift amounts. 3. The tracking control device according to claim 2, wherein the first and second variable gain amplifiers are set. 6. The detecting means scans a tape running in a direction opposite to the normal running with a first or second head, and obtains a first or second tracking error signal from a saturation characteristic of the obtained tracking error signal. 6. The tracking control device according to claim 5, wherein the amount of deviation is detected. 7. The gain control means includes a list of gains set in the first or second variable gain amplification unit for each tracking shift amount corresponding to the shift amount detected by the detection means. 6. The tracking device according to claim 5, wherein the gain is previously provided, and a gain corresponding to the shift amount is set in the first or second variable gain amplifying unit for each of the tracking shift amounts with reference to the data. Control device. 8. A magnetic recording / reproducing apparatus for recording / reproducing information on / from a magnetic tape by a plurality of magnetic heads on a rotating cylinder, wherein the reproducing magnetic head and the reproducing magnetic head are provided by using the tracking control device according to claim 1. A magnetic recording / reproducing apparatus for performing tracking control between tracks on a magnetic tape.