JPH0652606A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a good reproduced picture even in a recorded tape having a curved track at the time of reproducing for a long time, in a VTR in which at least a pilot signal for controlling tracking is recorded. CONSTITUTION:This device is constituted with a curved track detecting block 40 which detects a curved track, a SP head/LP head control block 14 which controls so as to switch reproducing heads by its output, and a SP head/LP head selecting switch 15 which switches reproducing heads by its control, etc. Thereby, the reproduction of a long time mode using the optimum reproducing head in accordance with the curvature of a track is performed and a good reproduced picture can be obtained.

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 such as a VTR, and more particularly to a magnetic recording / reproducing apparatus for recording / reproducing a pilot signal for tracking control in addition to a video signal and an audio signal.

[0002]

2. Description of the Related Art Generally, in a VTR, the track width of a magnetic head for reproducing a signal recorded in a long time mode is wider than the width of a recording track recorded in a long time mode. Therefore, when reproducing in the long-time mode, the magnetic head of the VTR scans not only the recording track being reproduced but also the adjacent recording track. As a result, there is a problem in that a good reproduction screen cannot be obtained due to the influence of crosstalk from adjacent tracks.

As one of the methods for solving such a problem,
Magazine "HiVi" (published by Stereo Sound Co., Ltd.);
As described in the November 1991 issue, pages 116-121,
Conventionally, in addition to two heads for standard mode, two heads for long-time mode, and a total of four heads for video signals, a narrow head having a width almost the same as the recording track width recorded in the long-time mode was used. A technique is disclosed in which two magnetic heads are provided and the reproducing head can be selected by an external switch during long-time mode reproduction.

[0004]

In the above-mentioned prior art, during reproduction in the long time mode, a narrow magnetic head having a width almost the same as the recording track width recorded in the long time mode is selected. By reproducing, the influence of crosstalk from the adjacent tracks is eliminated, and a good reproduced image can be obtained.

However, in the above-mentioned conventional technique, a dedicated magnetic head must be newly added, and
When reproducing a tape with a track bend, if a narrow head is used, scanning of the recording track will be incomplete, and S /
There is also a problem that N deteriorates.

In order to prevent this problem, in the above-mentioned conventional technique, the magnetic head used for reproduction can be selected to be narrow or wide by an external switch. However, this is performed by the operation of the VTR user, and usability is not taken into consideration. Also, when playing back tapes with track bends for a long time,
It is quite conceivable that the R user does not operate the above external switch and uses the narrow head. In this case, the S / N deteriorates as described above. Not done.

An object of the present invention is to solve such a problem and to provide a VTR which gives a good reproduced image in a long time mode without newly providing a dedicated magnetic head.

Another object of the present invention is to provide a VTR which automatically reproduces by an optimum reproducing magnetic head without switching by an external switch during long-time mode reproduction.

It is another object of the present invention to provide a VTR which gives as good a reproduced image as possible even when scanning a recording track having a track bend using a narrow head during a long time mode reproduction. .

[0010]

In order to achieve the above object, the present invention has a magnetic head having a width substantially the same as the track width recorded in the long time mode and a track width substantially the same as the track width recorded in the normal mode. A magnetic head having a width is provided, and means for detecting track bending and means for switching the reproducing head according to the detection result are provided.

In order to achieve the above object, the present invention further comprises means for detecting a pilot signal component recorded on a reproduction track, and tracking control means for changing the tracking control according to the detected output.

[0012]

Using the fact that the ratio of the recording track widths of the long-time recording mode and the normal recording mode in the recording format of 8 mm VTR is 2: 1, the magnetic tape for reproducing the tape recorded in the long-time mode and having no track bending is used. The head is a head with a width almost the same as the track width recorded in the long-time mode, and the magnetic head that reproduces a tape with track bend recorded in the long-time mode is almost the same width as the track width recorded in the normal mode. The head of Therefore, the magnetic head for reproducing the tape recorded in the long-time mode and having track bending can be used as the magnetic head for normal mode reproduction, and a dedicated magnetic head is not particularly required.

In the means for detecting track bending,
The amount of track bending of the tape recorded in the long time mode is detected from the pilot signal component. The means for switching the read heads accordingly automatically selects the optimum read magnetic head according to the track bend.

The minimum value of the pilot signal component recorded on the reproduction track is detected by the means for detecting the pilot signal component recorded on the reproduction track, and the tracking control means detects the minimum value of the pilot signal component recorded on the reproduction track. The minimum amplitude value of the reproduced FM envelope is maximized by offsetting the tracking so that the minimum value is maximized.

[0015]

The present invention will be described below with reference to the illustrated embodiments. First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a block diagram of a reproduction system of an 8 mm VTR according to this embodiment.

In FIG. 1, 1 is a magnetic tape, 2 is a plus azimuth wide (SP) rotary magnetic head having a track width of, for example, 20 μm, and 3 is a minus azimuth wide (SP) having the same track width as 2. The rotary magnetic head 4, 4 is a plus azimuth narrow (for LP) rotary magnetic head having a track width of 10 μm, 5 is the minus azimuth narrow (for LP) rotary magnetic head having the same track width as 4, 6 to 9 is a reproduction amplifier, 10 and 11 are switches for selecting positive azimuth / minus azimuth, and 12 is S.
FM envelope detection circuit for P head, 13 is FM envelope detection circuit for LP head, and 14 is SP head / L
P head control block, 15 SP head / LP head selection switch, 16 audio signal filter, 17 audio signal processing circuit, 18 audio output terminal, 19 color signal filter, 20 color signal processing circuit, 21 Is a color signal output terminal, 22 is an AGC (Automatic Gain Control) circuit, 2
3 is a filter for luminance signal, 24 is a peaking circuit, 25
Is a luminance signal processing circuit, 26 is a luminance signal output terminal, 27 is an adding circuit, 28 is a video signal (luminance signal + color signal) output terminal, 29 is a pilot signal filter, 30 is a converter, 31 is a reference signal generating circuit, 32 is a selection circuit, 33 is a fH tuning amplifier, 34 is a 3fH tuning amplifier, 35 is a comparator, 36 is a changeover switch, 37 is an inverter,
38 is a tracking control circuit, 39 is a capstan motor, 40 is a track bending detection block, and 41 is a head switching pulse output circuit.

The operation in the long-time mode (hereinafter referred to as LP mode) reproduction in the above-mentioned structure will be described. The LP mode signal recorded on the magnetic tape 1 with a track width of about 10 μm is reproduced through the LP rotary magnetic heads 4 and 5 having a width of, for example, 10 μm, which is almost the same as the recording track width according to the recorded azimuth. A positive azimuth / minus azimuth selection switch 1 which performs a switching operation by the head switching pulse output from the head switching pulse output circuit 41 after being sufficiently amplified by the amplifiers 8 and 9.
It is input to the SP head / LP head selection switch 15 via 1.

SP head / LP head control block 14
Control signal selects the SP head / LP head selection switch 15 to the LP head side, and the output from the switch 15 is an audio signal filter 16, a color signal filter 19, an AGC circuit 22, a pilot signal filter 29.
Are input respectively. An audio signal component is extracted from the signal input in the audio signal filter 16, audio processing such as FM demodulation is performed by the audio signal processing circuit 17, and output from the audio output terminal 18. The color signal component extracted from the signal input in the color signal filter 19 is
The color signal processing circuit 20 performs color signal processing such as returning to a high frequency range by frequency conversion, and outputs the color signal output terminal 26.
Will be output. The amplitude of the signal input to the AGC circuit 22 is adjusted, the luminance signal is extracted by the luminance signal filter 23, the frequency characteristic is adjusted by the peaking circuit 24, and the luminance signal processing such as FM demodulation is performed by the luminance signal processing circuit 25. And is output from the luminance signal output terminal 18. The color signal and the luminance signal are added by the adding circuit 27 and output from the video signal (luminance signal + color signal) output terminal 28.

The pilot signal for tracking control is extracted from the reproduced signal by the pilot signal filter 29 and input to the converter 30. Here, the recording format of the pilot signal will be described with reference to FIG.

The pilot signal is recorded on the track of the magnetic tape 1 as shown in FIG. A1 to A4 are tracks recorded in the same azimuth, and B1 to B4
Is the track recorded in reverse azimuth. Note that, in FIG. 4, for convenience of description, only the area in which the video signal is recorded is shown on the track, excluding the PCM recording area, etc.
Unless otherwise specified). The pilot signals f1 to f4 recorded by switching for each track are
For example, f1 = 6.5fH, f2 = 7.5fH, f3 =
The difference between 10.5 fH and f4 = 9.5 fH (fH is the horizontal synchronizing signal frequency of the television signal) and the adjacent pilot signal is 1 fH and 3 fH. This difference component and the frequency of the pilot signal are about 100
Using 8 kHz and low azimuth loss, the 8 mm VTR performs tracking control during reproduction.

Returning to FIG. 1, the operation after the pilot signal is input to converter 30 will be described.
F1 to f4 having the same frequency as the recorded pilot signal are output from the reference signal generation circuit 31 to the selection circuit 32, and the selection circuit 32 is sequentially selected according to the head switching pulse.
Thus, one frequency that is the same as the pilot signal recorded on the reproduction track is selected and input to the converter 30. The converter 30 multiplies the input pilot signal by the reference signal from the selection circuit 32 to generate the difference frequency components fH and 3fH between the reproduction track and both adjacent tracks.

The generated fH and 3fH are respectively fH
After being extracted and amplified by the tuning amplifiers 33 and 3fH of the tuning amplifier 34, they are input to the comparator 35 for level comparison. The output change direction of the comparator 35 and the track shift direction have the opposite relationship when scanning the recorded track of f1 and the recorded track of f2 (f2 and f).
3, f3 and f4 and f4 and f1 are the same), the comparator 3
The output of No. 5 is inverted via the inverter 37, and the changeover switch 36 switches each field (track) by the head switching pulse. Changeover switch 36
Is output to the tracking control circuit 38 so that the tracking control circuit 38 can make the ratio of the fH component and the 3fH component in one track equal.
Control 9

As a result of the above operation, when there is relatively no track bending in the LP reproduction, a narrow head is used to completely scan the recording track for normal reproduction F.
An M envelope can be obtained. However, if there is a track bend, the recording track cannot be completely scanned, and it may not be possible to obtain a normal reproduction FM envelope. Therefore, the track bend detection block 40
Thus, the track bending is detected, and a signal indicating whether or not the SP head is used during LP reproduction is output. The signal is
Input to the SP head / LP head control block 14,
The head used for reproduction is determined by the SP head / LP head selection switch 15 using the output of the control block 14.

Now, the track bending will be described with reference to FIG. In the figure, C1 and C2 are tracks recorded in the same azimuth, and D1 and D2 are tracks recorded in the reverse azimuth. In the figure, when the recording track is bent (= track bending) as shown by the solid line, the narrow (LP) head 4 (or 5)
When the track is scanned as shown by the broken line, the recording track is not completely scanned by the narrow (LP) head 4 (or 5) at the upper part of the track in the drawing. In the present embodiment, when there is such a track bend, the read head is changed from the narrow width (LP) to the wide width (SP) according to the degree thereof, thereby improving the incomplete scanning of the recording track having the track bend. I am trying to do it.

FIG. 6 shows DA4 (Double Azimuth 4Heads
) Shows the head and tape on the cylinder of the system. In the figure, 1 is a magnetic tape, 84 and 85 are guide rollers, 88 is a rotation cylinder, 2 is a plus azimuth wide (SP) head, and 5 is a minus azimuth narrow (L).
P) head, 4 is a plus azimuth narrow (LP) head, and 3 is a minus azimuth wide (SP) head. FIG. 7 shows the scanning range on the magnetic tape when the track is bent by the wide (SP) heads 2 and 3 and the narrow (LP) heads 4 and 5.

As shown in FIG. 7, a narrow (LP) head 4 (or 5) having a track width of 10 μm is formed on the magnetic tape 1.
When a recording track 71 having a curved track recorded in the LP mode is reproduced by the same narrow (LP) head 4 (or 5), the LP head scanning range 72 surrounded by a broken line is scanned and the recording track is scanned. Becomes incomplete. On the other hand, this same recording track has a track width of 2
When reproducing with a wide (SP) head 2 (or 3) of 0 μm, the SP head scanning range 73 surrounded by the one-dot chain line is scanned, and the recording track is almost completely scanned.

FIG. 2 shows the internal structure of the track bend detection block 40 shown in FIG. In FIG. 2, the SP / LP detection circuit 51 determines whether SP recording or LP recording is performed based on the signal input from the output terminal of the comparator 35 of FIG. 1 to the input terminal 50. When it is determined that the SP recording is performed, the SP head is selected by the head selection circuit 64, and a signal indicating "SP head" is output via the output terminal 56 to the SP head / LP head control block 1 of FIG.
4 is input.

In addition, based on the signal input from the output terminal of the changeover switch 36 of FIG. 1 to the input terminal 52, the track bend detection circuit 53 performs S reproduction during LP reproduction.
It is determined whether or not the P head needs to be used. Then, if it is determined that the SP head is necessary, a signal indicating the "SP head" is input to the gate 55 from the track bend detection circuit 53 if the signal indicating the "LP head" is not necessary.

Further, the external input terminal 54 of FIG.
Is a terminal to which the output of the switch operated by the user of is input. That is, in this embodiment, the user of the VTR can select whether the reproducing head at the time of LP reproduction is "automatically controlled" or "forced to use the SP head" by a switch (not shown). Accordingly, the gate 55 causes the head selection circuit 64 only when the signal from the track bend detection circuit 53 is “LP head” and the input to the external input terminal 54 is “automatic control”.
A signal indicating "LP head" is output to. Other than that,
A signal indicating “SP head” is output from the gate 55 to the head selection circuit 64.

The head selection circuit 64 selects the LP head only when both the outputs of the SP / LP detection circuit 51 and the gate 55 indicate the "LP head", and the information is selected via the output terminal 56, as shown in FIG. Is input to the SP head / LP head control block 14 of FIG. Other than that, SP head /
The "SP head" information is input to the LP head control block 14.

FIG. 3 shows the internal structure of the SP head / LP head control block 14 shown in FIG. In FIG. 3, information indicating normal reproduction (SP, LP) or special reproduction (search, etc.) is input to the input terminal 42, and the switch 61 is controlled by this.

When the switch 61 indicates normal reproduction, the output of the track bend detection block 40 of FIG. 1 is input to the SP / LP head switching control circuit 62 via the input terminal 57 and the switch 61. In the SP / LP head switching control circuit 62, the input signal is "SP
SP head for "head", LP for "LP head"
A switch switching control signal is output from the output terminal 63 so as to switch the head to the head.
The switching state of the SP head / LP head selection switch 15 is controlled.

When the switch 61 indicates special reproduction, the SP head FM envelope detection circuit 12 and the LP head FM envelope detection circuit 13 shown in FIG.
Output from the comparator 6 via the input terminals 58 and 59, respectively.
Input to 0. The comparator 60 determines the head having the larger output amplitude, and the information is sent to the S through the switch 61.
It is input to the P / LP head switching control circuit 62. S
In the P / LP head switching control circuit 62, a switch switching control signal is output from the output terminal 63 so as to switch the head to the head having the larger output amplitude, and the SP head / LP head selection switch 15 of FIG.
Control the switching state of.

Next, the track bend detection circuit 53 shown in FIG.
Thus, a method for determining whether or not the track is bent enough to use the SP head during LP reproduction will be described with reference to FIGS. 8 and 9. 8 and 9 show head switching pulses with and without track bending,
3 shows the outputs of the tuning amplifiers 33 and 34 and the comparator 35 of FIG. 1, respectively.

In FIGS. 8 and 9, the frequency of the pilot signal recorded on the reproduction track is switched, for example, from f1 to f2 by the head switching pulse 90. Correspondingly, the fH components 91 and 96 from the adjacent tracks are f
2 → f1 is switched, and 3fH components 92 and 97 from the other adjacent track are switched to f4 → f3. Here, the reproduction amounts of the fH component and the 3fH component are shown by the area with the arrow direction of the figure being positive, and the tracking operation is controlled so that the areas of the fH component and the 3fH component are equal in each field.

The output of the comparator 35 (fH component-
The 3fH component) is indicated by 93 and 98 in FIGS. The state after tracking control when there is no track bend is shown in FIG. 8, and when there is no track bend, the fH component 91 and the 3fH component 92 are flat in the field as shown in the figure. In addition, since the fH component 91 and the 3fH component 92 have the same area in the field after the tracking control, (fH component-3fH component)
93 is zero.

On the other hand, FIG. 9 shows a state after tracking control when there is a track bend. When there is a track bend, the fH component 96 and the 3fH component 97 are not flat in the field as shown in FIG.
The H component-3fH component) shows a characteristic as shown by 98. Therefore, the threshold level 99,100 is set to a predetermined value, and the threshold level 99,100 is exceeded (fH
Component-3fH component) is present, SP is reproduced at the time of SP reproduction.
It is determined that the track is bent enough to use the head. Here, exceeding the threshold level means (fH component-3fH component) 98
Is above threshold level 99 and / or below threshold level 100. This is the principle of the method for detecting the amount of track bending according to this embodiment. The track bend detection described above is performed after the tracking control.

By the way, track bending may change during reproduction, such as recording on a single tape by a plurality of types of VTRs, and an appropriate reproduction head may change. On the other hand, on the other hand, track bending is detected (fH component -3, though the appropriate reproducing head remains unchanged).
It is possible that the fH component) changes unstablely across the threshold level due to various factors. Therefore, in the present embodiment, the head switching operation is actually provided with hysteresis so that the reproducing head is switched only when an appropriate reproducing head is changed such as the recorded VTR.

FIG. 10 shows the head switching pulse and (fH
Component-3fH component) characteristics, and the SP / LP head switching operation with hysteresis will be described with reference to this figure. In FIG. 10, 90 is a head switching pulse for switching between a positive azimuth head and a negative azimuth head, 159 and 162 are first threshold levels, 153 and 156 are second threshold levels, and 150, 151 and 152 are (fH components) respectively. −
The characteristics A, B, and C of the 3fH component) are shown.

As shown in the characteristic A of (fH component-3fH component), in the range where (fH component-3fH component) 150 exceeds the second threshold levels 153 and 156, the wide (SP) head is always used. In addition, (fH component-3fH
As shown in the characteristic C of (Component), in the range where (fH component-3fH component) 152 does not exceed the first threshold levels 159 and 162, the reproducing head always uses a narrow (LP) head (of course, this head switching). Needless to say, the automatic selection control of (1) is a control operation at the time of performing LP reproduction of the recording track in the LP mode in the mode in which the reproducing head is "automatically controlled".

The characteristic B of (fH component-3fH component)
As shown in, when the (fH component−3fH component) 151 is between the first threshold level 159, 162 and the second threshold level 153, 156, the wide (S
P) / narrow width (LP) head is not switched and reproduction is performed using the head currently used. That is, the reproducing head that exhibits the characteristic B of (fH component-3fH component) from the beginning or is changed from the characteristic C of (fH component-3fH component) to the characteristic B of (fH component-3fH component) is
Narrow width (LP) head (fH component-3fH component)
The reproducing head used when the characteristic A is changed to the characteristic B of (fH component−3fH component) is a wide (SP) head.

According to this embodiment having such a configuration / operation, the wide head for coping with the track bending at the time of LP reproduction can be used also as the SP head, and it is not necessary to provide a dedicated head. In addition, the narrow head and the wide head can automatically select the optimum reproducing head according to the track bending during LP reproduction.

Further, since track bending is detected by using the low-frequency pilot signal recorded for tracking control, it is not necessary to write a new control signal, and a track is recorded using a high-frequency FM envelope. False detection due to a head touch difference or the like is reduced as compared with the detection of bend.

Next, a second embodiment of the present invention will be described with reference to FIGS.
3 will be used for the explanation. FIG. 11 shows a block diagram of a reproduction system of an 8 mm VTR according to this embodiment. In this example,
A track bend detection block 105 is provided as an alternative to the track bend detection block 40 of FIG.
In addition to the function of the embodiment, the block 105 also controls the peaking circuit 24. Here, in FIG. 11, portions corresponding to those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted to avoid duplication (note that this is the same in the following, and the same portions as those in the previous drawings are referred to. Are also denoted by the same reference numerals in the subsequent drawings, and description thereof will be omitted).

The operation during the LP mode reproduction of this embodiment will be described. When a recording track having a curved track is reproduced by a narrow head, the amplitude of a reproduction FM envelope is partially reduced. The portion where the amplitude becomes small causes the S / N of the reproduced video signal to deteriorate. Therefore, the track bend detection block 105 that has detected the track bend from the output of the changeover switch 36 is (fH component −3).
The frequency characteristic of the peaking circuit 24 is varied according to the (fH component) to improve the S / N.
When (fH component-3fH component) becomes large and the variable control of the frequency characteristic of the peaking circuit 24 reaches a level at which a good reproduced image cannot be obtained, the track bend detection block 105 causes the SP head / LP A signal is output to the head control block 14 to switch to the wide (SP) head, whereby the SP head / LP head selection switch 15 is switched to the wide (SP) head side.

FIG. 12 shows the internal structure of the track bend detection block 105 shown in FIG. In FIG. 12, FIG.
Based on the signal input from the output terminal of the comparator 35 to the input terminal 50, the SP / LP detection circuit 51 determines whether SP recording or LP recording. When it is determined that the SP recording is performed, the head selecting circuit 64 selects the SP head, and the signal indicating the “SP head” is output to the output terminal 56.
Is input to the SP head / LP head control block 14 of FIG.

Further, based on the signal inputted from the output end of the changeover switch 36 of FIG. 11 to the input terminal 52, the track bend detection circuit 53 judges whether or not the SP head needs to be used during the LP reproduction. It And S
If it is determined that the P head is required, a signal indicating "SP head" is input to the gate 55 from the track bend detection circuit 53, if not required.

The signal from the track bend detection circuit 53 is the "LP head" and the external input terminal 54
The signal indicating "LP head" is output from the gate 55 to the head selection circuit 64 only when the signal from the above is "to be automatically controlled", and otherwise, the gate 55 indicates "SP head". The signal is output.

The peaking control circuit 110 uses SP / LP
It operates when both the signals from the detection circuit 51 and the gate 55 indicate "LP head", and the track bend detection circuit 5
Output terminal 11 according to the track bending amount information from 3
11, the frequency characteristic of the peaking circuit 24 of FIG. 11 is changed.

The head selection circuit 64 selects the LP head only when both outputs of the SP / LP detection circuit 51 and the gate 55 indicate the "LP head", and the information thereof is output via the output terminal 56 and shown in FIG. Is input to the SP head / LP head control block 14. Other than that, SP head / L
Information of “SP head” is input to the P head control block 14.

Next, referring to FIG. 13, (fH component-3f
H component), control of peaking circuit 24, SP head /
The relationship with switching of the LP head will be described. In the figure, 90 is a head switching pulse for switching between the positive azimuth head and the negative azimuth head, and 130
Is the (fH component-3fH component) characteristic and is indicated by a two-dot chain line 13
1, 132 is the first threshold level, and 133,134 indicated by the one-dot chain line are the first threshold levels 131, 13
This is the second threshold level set to be larger than 2.

In this embodiment, (fH component-3fH component)
Until it exceeds the first threshold level 131, 132, the narrowing (LP) head is used for reproduction, and the peaking circuit 24
It does not change the frequency characteristics of. In addition, (fH component-3f
Until the H component) exceeds the first threshold levels 131 and 132 and exceeds the second threshold levels 133 and 134, reproduction is performed by the narrow (LP) head, and the peaking circuit 2
The frequency characteristic of No. 4 is changed according to the amount of track bending. When (fH component-3fH component) exceeds the second threshold levels 133 and 134, the width is wide (SP).
Play with the head. In addition, as shown in FIG.
The fH component) characteristic 130 is the second threshold level 13
Since it exceeds 3,134, in this case it is wide (SP)
It will be played on the head.

As described above, according to the second embodiment, the first
In addition to the effects of the embodiment, it is possible to improve the S / N deterioration when reproducing a recording track having a track bend which is not so large as switching to a wide head.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 14 is an 8 mm VTR according to this embodiment.
2 is a block diagram of a reproducing system of FIG. 1, in which parts corresponding to those in FIG. 1 are designated by the same reference numerals. In this embodiment, in order to improve the accuracy of track bend detection,
The track bend is detected by comparing the pilot signal components of the reproduction track and the adjacent track.

In FIG. 14, 115 is a selection circuit and 11
Reference numeral 6 is an inverter, 117 is a converter, 118 is a fH tuning amplifier, 119 is a 3fH tuning amplifier, 120 is a reproduced pilot signal component detection circuit, 121 is an adjacent pilot signal component detection circuit, and 122 is a pilot signal component comparison circuit.

The operation during the LP mode reproduction will be described with reference to FIG. The signal recorded in the LP mode on the magnetic tape 1 is picked up by the LP rotary magnetic heads 4 and 5 and then sufficiently amplified by the reproduction amplifiers 8 and 9 and passed through the plus azimuth / minus azimuth selection switch 11. , SP head / LP head selection switch 15
Entered in. A pilot signal is extracted from a signal output from the SP head / LP head selection switch 15 by a pilot signal filter 29 and input to converters 30 and 117, respectively.

The reference signal generation circuit 31 outputs f1 to f4 having the same frequency as the recorded pilot signal, and the selection circuit 32 is sequentially selected according to the head switching pulse.
Thus, the same one frequency as the pilot signal recorded on the reproduction track is selected and input to the converter 30. By multiplying the pilot signal (output of the pilot signal filter 29) input to the converter 30 and the reference signal (output of the selection circuit 32), difference frequency components fH and 3fH between the reproduction track and both adjacent tracks are created. . The generated fH and 3fH are extracted and amplified by the tuning amplifier 33 of fH and the tuning amplifier 34 of 3fH, respectively, and then input to the comparator 35 and the adjacent pilot signal component detection circuit 121, respectively. The outputs of the tuning amplifiers 33 and 34 input to the comparator 35 are level-compared by the comparator 35, and are used for tracking control or the like as in the first embodiment. On the other hand, the adjacent pilot signal component detection circuit 121 receiving the outputs of the tuning amplifiers 33 and 34 detects the pilot signal components recorded on both tracks adjacent to the reproduction track.

Further, the reference signal generation circuit 31 outputs f1 to f4 having the same frequency as the recorded pilot signal, and the selection circuit 115 sequentially selects the selection circuit 32 according to the head switching pulse inverted by the inverter 116. Deviates from the output by 1 (for example, f1 is f2
One frequency (shifted to) is selected and input to converter 117. By multiplying the pilot signal (output of the pilot signal filter 29) input to the converter 117 and the reference signal (output of the selection circuit 115), the pilot signal component of the reproduction track becomes the difference frequency component fH.
Or it is made as 3fH.

FH and 3fH, which are alternately produced according to the head switching pulse, are extracted from the converter 117 by the tuning amplifier 118 of fH and the tuning amplifier 119 of 3fH, respectively, and amplified, and then input to the reproduction pilot signal component detection circuit 120. It As a result, the reproduced pilot signal component detection circuit 120 detects the pilot signal component recorded on the reproduced track.

In the pilot signal component comparison circuit 122,
The output of the reproduced pilot signal component detecting circuit 120 and the output of the adjacent pilot signal component detecting circuit 121 are compared. The comparison result is input to the track bend detection block 40, and if the ratio of the adjacent pilot signal component to the reproduced track pilot signal component is below a predetermined value, control is performed to select the "LP head",
When it exceeds the predetermined value, control is performed to select the "SP head".

As described above, in this embodiment, since the track bend is detected by detecting the ratio of the pilot signal components of the reproduction track and the adjacent track, there is little erroneous detection regardless of the recording state of the pilot signal. The track bend can be detected with high accuracy.

Next, a fourth embodiment of the present invention will be described with reference to FIGS.
This will be described using 6. In the present embodiment, the minimum output of the pilot signal of the reproduction track having the track bend is maximized by adding the offset to the tracking, thereby maximizing the minimum amplitude of the reproduction FM envelope. It was done.

FIGS. 15A and 15C show the magnetic tape 1.
FIG. 15 shows the relationship between the recording track having the track bend and the narrow (LP) head recorded in FIG. 15, and (b) and (d) of FIG. 15 respectively show the corresponding reproduction FM envelopes.

FIG. 15A shows a narrow (LP) head 4 (or 5) when a recording track 170 recorded on the magnetic tape 1 and having a curved track is tracked by the pilot signal. ) Indicates that a region 172 surrounded by a broken line is scanned, for example.
At this time, the reproduced FM envelope for one track has a portion where the output level is very small (right side in the figure), as shown in FIG. In such a reproduction FM envelope, there is a part of the reproduction screen where the S / N is very bad.

Therefore, in order to prevent the output level of the reproduction FM envelope from having a very small portion, that is, to increase the minimum output level of the reproduction FM envelope as much as possible, the tracking offset is set as shown in FIG. Attach. As a result, with respect to the recording track 171 having a curved track recorded on the magnetic tape 1,
By scanning the narrow (LP) head 4 (or 5) in a region 173 surrounded by, for example, a broken line, a reproduced FM envelope as shown in FIG. 15D can be obtained.

The size relationship of the reproduced FM envelope is as follows.
Since there is a correlation with the magnitude relationship of the pilot signal component of the reproduction track, by increasing the minimum value of the pilot signal component of the reproduction track as much as possible, the minimum value of the output level of the reproduction FM envelope is maximized and good reproduction is achieved. A picture is obtained. The present embodiment is designed to perform control based on such a principle. However, depending on the state of track bending, the minimum value of the output level of the reproduced FM envelope which is made as large as possible may be so small as to obtain an unacceptable low S / N reproduced image. Therefore, when the minimum value of the pilot signal component of the reproduction track which is made as large as possible is lower than a predetermined value, the narrow (LP) head is switched to the wide (SP) head.

FIG. 16 shows a block diagram of a reproducing system for performing these controls. 16 is provided with a selection circuit 180, a converter 181, a tuning amplifier 182 for fH, and a minimum value detection circuit 183 in addition to the configuration of FIG. 1 described above, and the tracking control circuit 3 is controlled by the output of the minimum value detection circuit 183.
The tracking control by 8 is provided with an offset.

The operation during the LP mode reproduction will be described with reference to FIG. The signal recorded in the LP mode on the magnetic tape 1 is picked up by the rotary magnetic heads 4 and 5 for LP and then sufficiently amplified by the reproduction amplifiers 8 and 9.
Switch 11 for selecting plus azimuth / minus azimuth
Via the SP head / LP head selection switch 15 and L
It is input to the FM envelope detection circuit 13 for the P head. A pilot signal is extracted from a signal input to the SP head / LP head selection switch 15 by a pilot signal filter 29, and this is converted into converters 30 and 18.
Enter in 1 respectively. Then, using the signal input to the converter 30, tracking control is performed as in the first embodiment.

The signal input to the converter 181 is multiplied by the reference signal that is switched by the head switching pulse output by the selection circuit 180, so that the pilot signal component of the reproduction track is the difference frequency component between the pilot signal and the reference signal. Made as. Here, the selection circuit 180 includes pilot signals f1, f2, which are input to the converter 181 from the pilot signal filter 29.
f2, f1, f4, and f3 are selected for f3 and f4, respectively. That is, it operates so that the difference frequency between the pilot signal and the reference signal becomes fH.

The pilot signal component of the reproduction track created by the converter 181 is fed to the tuning amplifier 18 of fH.
After being taken out by 2 and amplified, it is inputted to the minimum value detection circuit 183. The minimum value detection circuit 183 detects the minimum value of the input pilot signal component of the reproduction track within one track, and the tracking control circuit 38 is provided to offset the tracking control so as to increase the minimum value.
To control.

However, as described above, when the amount of track bending is large, there is a case in which even if the minimum value of the pilot signal component of the reproduction track is made as large as possible, it is not large enough to obtain a good reproduced image. Therefore, a signal indicating the minimum value of the pilot signal component of the reproduction track, which is maximized by adding an offset to the tracking control, is input to the track bend detection block 40,
When the minimum value of the pilot signal component of the reproduction track maximized by the track bend detection block 40 is smaller than a predetermined value, the SP head is switched from the narrow (LP) head to the wide (SP) head. /
The LP head selection switch 15 is controlled.

As described above, in this embodiment, the minimum value of the reproduced FM envelope when there is a track bend can be maximized, and a good reproduced image can be obtained.

In this embodiment, the minimum value is detected by using the pilot signal component of the reproduction track.
The high frequency may cause erroneous detection due to a head touch difference or the like, but in some cases, the same control can be performed using the reproduction FM envelope.

Next, a fifth embodiment of the present invention will be described with reference to FIGS.
This will be described using 8. In this embodiment, the track bend is detected by comparing the maximum value and the minimum value of the pilot signal component of the reproduction track.

FIG. 17 shows a block diagram of a reproducing system of an 8 mm VTR according to this embodiment. In this embodiment,
The output of the pilot signal filter 29 of FIG. 1 has two systems, and a selection circuit 300, a converter 301, an FH tuning amplifier 302, and a Max / Min detection circuit 303 are added, and parts corresponding to FIG. Similarly, the same reference numerals are given.

In FIG. 17, during LP mode reproduction,
The reproduced signal picked up by the LP rotary magnetic heads 4 and 5 is input to the pilot signal filter 29, and the pilot signals extracted by the pilot signal filter 29 are input to the converters 30 and 301, respectively. Then, by the signal input to the converter 30, tracking control and the like are performed as in the first embodiment.

The signal input to the converter 301 is multiplied by the reference signal switched by the head switching pulse output by the selection circuit 300, so that the pilot signal component of the reproduction track is the difference frequency component between the pilot signal and the reference signal. Made as. Here, the selection circuit 300 includes pilot signals f1, f2, which are input to the converter 301 from the pilot signal filter 29.
f2, f1, f4, and f3 are selected for f3 and f4, respectively. That is, it operates so that the difference frequency between the pilot signal and the reference signal becomes fH.

The pilot signal component of the reproduction track produced by the converter 301 is fed to the fH tuning amplifier 30.
After being taken out by 2 and amplified, it is inputted to the Max / Min detection circuit 303. In the Max / Min detection circuit 303, 1 of the pilot signal component of the input reproduction track is input.
The maximum and minimum values in the track are detected and compared. Then, as will be described later, since the difference between the maximum value and the minimum value corresponds to the track bending amount, a signal corresponding to the track bending amount is sent to the track bending detection block 40.

In the track bend detection block 40, the subsequent operations such as determining whether to switch the head used for reproduction according to the track bend amount,
This is similar to the first embodiment.

The above-described operation for detecting track bending is
This is effective even before tracking is started, and switching between the SP head and the LP head can be started before the tracking operation is completed.

Next, it will be described with reference to FIG. 18 that the difference between the maximum value and the minimum value of the pilot signal component of the reproduced track in one track corresponds to the track bending amount. 18A shows the relationship between recording tracks recorded on the magnetic tape 1 without track bending and a narrow (LP) head, and FIG. 18C shows recording on the magnetic tape 1. Recording track with curved track and narrow width (L
P) shows the relationship with the head.
(D) shows the reproduction levels of the pilot signal components from the corresponding tracks.

As shown in FIG. 18A, the narrow head (LP) head 4 (or 5) before tracking is applied.
Is located at a position shown in the figure, for example, with respect to the recording track 251 having no track bend, and scans so as to follow a locus surrounded by a broken line. At this time, in the example in the figure, it is narrow (LP)
Since the head is tracing the track on which the pilot signal of f1 is recorded, the reference signal f2 is selected so that the pilot signal component of the track on which the pilot signal of f1 is recorded is created as the fH component. .

In this embodiment, the pilot signal component of the reproduction track is detected as, for example, the detection points 252, 25.
Detection is made at 4 points of 3,254,255. The detection point drawn perpendicularly to the scanning track is larger than the range surrounded by the broken line in consideration of the leakage from the adjacent track in addition to the scanning range of the narrow (LP) head.

Recording track 251 with no track bend
From the above, when the pilot signal component of the reproduction track is detected, the result of FIG. 18 (b) is obtained. As is clear from the figure, when there is no track bending, the difference between the maximum value and the minimum value of the pilot signal component of the reproduced track within one track is zero.

Next, the case of a recording track having a curved track will be described with reference to FIGS. 18 (c) and 18 (d). As shown in (c) of FIG. 18, before the tracking is applied, the narrow (LP) head 4 (or 5) is located, for example, at a position shown in the figure with respect to the recording track 256 having a track bend, and is surrounded by a broken line. It scans so that it takes a traced path. At this time, in the example of the figure, f2 is selected as the reference signal, as in the case where there is no track bending.
Detection point 2 of the pilot signal component of the reproduction track
It is detected at 4 points of 52, 253, 254 and 255.

Recording track 256 with curved track
Therefore, when the pilot signal component of the reproduction track is detected, the result of (d) of FIG. 18 is obtained. As is clear from the figure, when there is a track bend, the difference between the maximum value and the minimum value of the pilot signal component of the reproduction track within one track appears with a certain value corresponding to the track bend.

In this way, the difference between the maximum value and the minimum value of the pilot signal component of the reproduction track within one track corresponds to the amount of track bending.

As described above, in the present embodiment, since the track bending can be detected before the tracking control, the optimum reproducing head can be selected earlier.

By the way, the present embodiment is effective in detecting a track bend during reproduction by a narrow (LP) head, but there is a problem in the accuracy of track bend detection during reproduction by a wide (SP) head. is there. Therefore, as a method of implementing the present embodiment, whether only the control of switching from the narrow (LP) head to the wide (SP) head is performed, or whether the track bend detection is always performed by the narrow (LP) head, Alternatively, it is effective to use this embodiment at the beginning of reproduction and then control according to the first embodiment.

For convenience of explanation, the difference between the maximum value and the minimum value is taken here, but it is also effective to take the ratio of the maximum value and the minimum value so as not to be influenced by the recording state of the pilot signal. Further, although the number of detection points is four in the present embodiment, the present invention is not limited to this, and a plurality of points of two points or more, or one track in general may be used. Furthermore, in the present embodiment, the output of the pilot signal filter 29 has two systems, but it is not always necessary to provide one system and the control may be performed by time division processing.

Next, a sixth embodiment of the present invention will be described with reference to FIG. The difference between this embodiment (FIG. 19) and the first embodiment (FIG. 1) is that the pilot signal filter 29 is
In FIG. 1, the output signal of the SP head / LP head selection switch 15 is input, whereas in FIG. 19, the plus head / minus azimuth selection switch 1 of the SP head is input.
The output signal of 0 is input, and the pilot signal component of the track adjacent to the reproduction track is always detected by the wide (SP) head so that the S / N can be detected well.

The operation during the LP mode reproduction will be described with reference to FIG. Heads used for playback are SP and L
Regardless of P, the reproduction signal picked up by the wide SP rotary magnetic heads 2 and 3 from the magnetic tape 1 for the extraction of the pilot signal and sufficiently amplified by the reproduction amplifiers 6 and 7 is positive azimuth / minus. The pilot signal is supplied to the pilot signal filter 29 through the azimuth selection switch 10, and the pilot signal is extracted by the pilot signal filter 29 and input to the converter 30. In this embodiment, operations other than the above are performed in the same manner as in the first embodiment.

As described above, in this embodiment, the pilot signal is always detected by the wide (SP) head, so that the pilot signal components of both tracks adjacent to the reproduction track can be efficiently detected, and the tracking control is performed. It is possible to improve the accuracy of track bend detection.

Next, a seventh embodiment of the present invention will be described with reference to FIGS.
2 is used for the explanation. In this embodiment, VSC (video subcode) is used to detect the self-recording (the recording VTR and the reproducing VTR are the same) and determine the priority reproducing head.

FIG. 20 shows a block diagram of a reproducing system of an 8 mm VTR according to this embodiment, which is the same as that shown in FIG.
In addition to the above configuration, switches 210 and 211 for selecting plus azimuth / minus azimuth for VSC (video subcode),
SP head / LP head selection switch 212 for VSC,
A VSC reading circuit 213 is added and an SP head / LP head control block 214 is provided instead of the SP head / LP head control block 14.

FIG. 21 shows the recording format of the magnetic tape in the 8 mm VTR. As shown in the figure, on the recording track recorded on the magnetic tape 1,
A VSC recording area 222 exists so as to be sandwiched between the video signal recording area 220 and the PCM audio recording area 221. In this embodiment, at the time of recording, a company name, a code representing the VTR model, a recorded VTR-specific code, etc. are recorded in the VSC recording area 222.

The operation during the LP mode reproduction will be described with reference to FIG. During this reproduction, the SP rotary magnetic heads 2 and 3 or the LP rotary magnetic heads 4 and 5 are recorded with the company name recorded in the VSC recording area 222, the VTR model code, the recorded VTR specific code, and the like. Is read, and is sufficiently amplified by the reproduction amplifiers 6, 7 or 8, 9 and input to the VSC SP head / LP head selection switch 212 via the VSC plus azimuth / minus azimuth selection switches 210 and 211. VSC
SP head / LP head selection switch 212 for SP
By the output of the head / LP head control block 214,
The reproducing head is selected, and the above data is input to the VSC reading circuit 213.

The VSC reading circuit 213 reads, from the above-mentioned recorded data, whether it is a self-recording in which there is no track bending or a self-recording in which there is a possibility that there is a track bending. When the self-recording is detected, the VSC reading circuit 213 inputs a signal indicating the self-recording to the SP head / LP head control block 214.

SP head / LP head control block 21
4 is a VSC reading circuit 21 for normal reproduction in the LP mode.
When the input from 3 indicates self-recording, the operation of the first embodiment is controlled to start from the LP head, and when the input from 3 does not indicate self-recording, the operation of the first embodiment is controlled to start from the SP head. The operation other than the above is the same as that of the first embodiment.

FIG. 22 shows the structure of the SP head / LP head control block 214 shown in FIG. 22 shows an arrangement in which an input terminal 223 and an output terminal 224 are added to the structure of FIG. 3 of the first embodiment described above, and the portions corresponding to those of FIG. 3 are designated by the same reference numerals.

A signal indicating normal reproduction or special reproduction is input from the input terminal 42 to control the switch 61. The switch 61 indicates normal reproduction, and the output of the track bend detection control block 40 of FIG. 20 input via the input terminal 57 (only SP recording or LP recording is shown before tracking is applied), When showing LP recording, the SP / LP head switching control circuit 62 determines the head to be used according to the output signal of the VSC reading circuit 213 of FIG. 20 which is input through the input terminal 223, and the output terminal 63 is used. , And controls the SP head / LP head selection switch 15 of FIG.

Further, the SP / LP head switching control circuit 62 outputs the SP for VSC of FIG. 20 via the output terminal 224.
The head / LP head selection switch 212 is controlled to pass the output of the currently used head.

As described above, in this embodiment, since the VSC (video subcode) is used to detect the self-recording and determine the reproducing head to be prioritized, a good reproducing image can be obtained.

The above-described first to seventh embodiments have been described by taking the configuration using four heads as an example, but the present invention is also effective for a VTR having a dedicated wide head corresponding to track bending and the like. is there. Further, although SP / LP detection is performed from the output of the changeover switch 36, the present invention is not limited to this, and any other place may be used as long as the error frequency of the pilot signal can be detected. Further, the pilot signal filter output may be followed by the pilot signal AGC. Furthermore, although the first and second embodiments use four types of reference signals f1 to f4, the present invention is not limited to this. For example, two types of f1 and f2 or 1 of f1 are used. Kind is good.

[0105]

As described above in detail, according to the present invention, when there is no track bending during the long-time mode reproduction, a width almost equal to the track width recorded in the long-time mode is provided without providing a dedicated head. With a narrow head having a, it is possible to obtain a good reproduced image without crosstalk.

Further, when there is a track bend, the track bend detection block detects the track bend amount from the pilot signal recorded for tracking control, and the optimum value is automatically detected by the SP head / LP head control block. Since the reproducing head is selected, S / N deterioration can be suppressed.

When the reproducing head is wide and there is track bending, the frequency characteristic of the peaking circuit is changed or the tracking control circuit adds an offset to the tracking to suppress the S / N deterioration.
A good reproduced image can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of a reproduction system of an 8 mm VTR according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration example of a track bend detection block of FIG.

FIG. 3 is an explanatory diagram showing a configuration example of an SP head / LP head control block in FIG.

FIG. 4 is an explanatory diagram showing an example of a recording format on a magnetic tape in which a pilot signal is recorded.

FIG. 5 is an explanatory diagram showing a recording track pattern having a track bend.

FIG. 6 is an explanatory diagram showing an example of the arrangement of magnetic heads mounted on the rotary cylinder according to the first embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a relationship between a recording track pattern having a track bend and a head scanning range.

FIG. 8 is an explanatory diagram showing pilot signal components when there is no track bending.

FIG. 9 is an explanatory diagram showing pilot signal components when there is a track bend.

FIG. 10 is an explanatory diagram for helping understanding of a hysteresis or the like of a head switching operation according to the first embodiment of the present invention.

FIG. 11 is a block diagram of a reproduction system of an 8 mm VTR according to a second embodiment of the present invention.

12 is an explanatory diagram showing a configuration example of a track bend detection block in FIG.

FIG. 13 is an explanatory diagram for helping understanding of control of a peaking circuit, head switching, and the like according to a second embodiment of the present invention.

FIG. 14 is a block diagram of a reproduction system of an 8 mm VTR according to a third embodiment of the present invention.

FIG. 15 is an explanatory diagram showing a relationship between tracking control and a reproduction FM envelope.

FIG. 16 is a block diagram of a reproduction system of an 8 mm VTR according to a fourth embodiment of the present invention.

FIG. 17 is a block diagram of a reproduction system of an 8 mm VTR according to a fifth embodiment of the present invention.

FIG. 18 is an explanatory diagram showing the relationship between the difference between the maximum value and the minimum value of the reproduced pilot signal component depending on the presence or absence of track bending.

FIG. 19 is a block diagram of a playback system of an 8 mm VTR according to a sixth embodiment of the present invention.

FIG. 20 is a block diagram of an 8 mm VTR reproduction system according to a seventh embodiment of the present invention.

FIG. 21 is an explanatory diagram showing a recording format example on a magnetic tape having a video subcode (VSC) recording area.

22 is an explanatory diagram showing a configuration example of an SP head / LP head control block in FIG. 20. FIG.

[Explanation of symbols]

 14,214 SP head / LP head control block 30,117,181,301 Converter 31 Reference signal generation circuit 32,115,180,300 Selection circuit 33,118,182,302 fH tuning amplifier 34,119 3fH tuning amplifier 35 comparator 40,105 track bending detection block

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Okada 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture

Claims (9)

[Claims] 1. A recording / reproducing function for at least two modes of a normal recording mode and a long-time recording mode, at least two rotary magnetic heads for a normal recording / reproducing mode paired with each other, and two paired long time recording heads. In a device having a rotary magnetic head for recording / reproducing mode and reproducing a recording signal on a magnetic tape by the rotary magnetic head, a detecting means for detecting track bending from the reproducing signal, and a reproducing magnetic head by the output of the detecting means. A magnetic recording / reproducing apparatus comprising: a selecting unit for selecting. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein a frequency variable peaking circuit is provided, and the frequency characteristic of the peaking circuit is changed by the output of the detecting means. 3. A recording / reproducing function of at least two modes of a normal recording mode and a long-time recording mode, and at least two paired rotary magnetic heads for normal recording / reproducing mode and two paired long-time recording heads. A rotary magnetic head for reproducing a recording signal on a magnetic tape having a recording / reproducing mode rotary magnetic head and a pilot signal for tracking control recorded in addition to a video signal and an audio signal. A magnetic recording / reproducing apparatus comprising: a detecting unit for detecting a track bend from the recording medium; and a selecting unit for selecting a reproducing magnetic head according to the output of the detecting unit. 4. The magnetic recording / reproducing apparatus according to claim 3, wherein a frequency variable peaking circuit is provided, and the frequency characteristic of the peaking circuit is changed by the output of the detecting means. 5. The extracting means for extracting the component of the pilot signal recorded on the reproducing track according to claim 3, and the component of the pilot signal recorded on the track adjacent to the reproducing track, and the extracting means. A magnetic recording / reproducing apparatus comprising: a comparing means for comparing the extracted pilot signal component of the reproducing track; and a detecting means for detecting a track bend by the output of the comparing means. 6. The extraction means for extracting the component of the pilot signal recorded on the reproduction track according to claim 3, and the minimum value detection for detecting the minimum value of the component of the pilot signal from the output of the extraction means. A magnetic recording / reproducing apparatus comprising: means and tracking control means for offsetting tracking so as to increase the minimum value detected by the minimum value detecting means. 7. The method according to claim 3, wherein the pilot signal component recorded on the reproduction track is extracted, and the maximum value and the minimum value of the pilot signal component are detected from the output of the extraction unit. A magnetic recording / reproducing apparatus comprising: maximum value / minimum value detecting means; and detecting means for detecting track bending based on the output of the maximum value / minimum value detecting means. 8. The magnetic recording / reproducing apparatus according to claim 3, wherein the pilot signal is always read from the output of the rotary magnetic head for normal reproduction mode. 9. A recording / reproducing function of at least two modes of a normal recording mode and a long-time recording mode, and at least two rotary magnetic heads for a normal recording / reproducing mode paired with each other and two long time pairs paired with each other. Having a rotary magnetic head for recording / reproducing mode, a rotary magnetic head reproduces a recording signal on a magnetic tape on which a pilot signal for tracking control and subcode information are recorded in addition to a video signal and an audio signal. The apparatus is provided with a detecting means for detecting a track bend from the pilot signal, and a selecting means for selecting a reproducing magnetic head by the output of the detecting means, and the sub-code information contains information indicating the recorded magnetic recording / reproducing apparatus. Is recorded, and the information indicating the recorded magnetic recording / reproducing apparatus is used to prioritize the selection by the selecting means. Magnetic recording / reproducing device as a characteristic.