JPH02195558A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the deviation of a head from a track by storing the tracking state of a tracing head pair in a storage circuit and controlling a preceding head pair after adding the tracking state of the tracing head pair at the time of post recording. CONSTITUTION:The 1st head pair 2a and 2b traces in the center of a track, ordinarily, and the position of the 2nd head pair 3a and 3b on the track is stored in the storage circuit 16. In the post recording state, the output from the storage circuit 6 is added to the output from a tracking detection circuit 13 through an adder 14 and a control loop works so that the output from the adder 14 becomes zero. Therefore, the 1st head pair 2a and 2b is controlled to be forcibly deviated to travel in a direction opposite to the deviation of the 2nd head pair 3a and 3b from the center of the track, and the traveling of the 1st head pair 2a and 2b is controlled to be offset so that the 2nd head pair 3a and 3b may pass the almost center of the track. Thus, the deviation of the head from the track is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording and reproducing apparatus equipped with a magnetic head position correction function used in digital audio tape recorders, video tape recorders, and the like.

2. Description of the Related Art Conventionally, in a digital audio tape recorder that performs recording and reproduction using a rotating head, a signal (for detecting the positional relationship between the head and the recorded track) is placed at a predetermined location on a track formed on a magnetic tape. A method is used in which a tracking detection signal (referred to as a tracking detection signal) is recorded and the tracking detection signal is used during playback to control the head so that it travels correctly on the track. (For example, Japanese Patent Application No. Sho E32-9304) An example of the above-mentioned conventional magnetic recording/reproducing device will be described below with reference to the drawings.

Figure 2 shows an example of a magnetic tape on which signals for tracking detection are recorded, and Figure 8 shows tracking using the conventional magnetic tape shown in Figure 2 (the head runs correctly on the recorded track). A configuration diagram showing an example of a device (controlling such a device is called “tracking”), No. 9
This figure shows the relationship between the tracks on the magnetic tape shown in FIG. 2 and the head locus, and FIG. 10 is a block diagram of the tracking detection circuit shown in FIG. 8.

In FIG. 8, 1 is a magnetic tape, 2a and 2b are a pair of heads that sequentially record and reproduce tracks from each other, and 3a, 3b?
A pair of heads installed at a position for recording and reproducing temporally delayed from the pair of heads 2a and 2b; 4 is a rotating cylinder to which heads 2a+2b, 3a, and 3b are attached; 9a and 9b are windings of the magnetic tape 1; 8a and sb are posts forming a running path for the magnetic tape 1; 5a and 5b are capstan motors and capstan shafts for running the magnetic tape 1; 6 is a pinch roller; 7 is a capstan motor FGl 10 outputs a signal with a frequency proportional to the rotation speed of 5a.
13 is a tracking detection circuit for detecting a tracking detection signal, 11 is an adder, and 12 is a drive circuit for driving the capstan motor 5a based on the output of the adder 11.

In the figure, FG7. The F/V converter 10° drive circuit 12 rotates the capstan motor 5a at a substantially constant rotation. The pinch roller 6 and the capstan shaft 5b apply the rotational force of the capstan motor 5a, which rotates at a constant rotation, to the magnetic tape 1, causing it to run at a nearly constant speed. The tracking detection circuit 13 detects the relative position between the traveling position of the head 2 al 2 b and the recorded track, and determines the F/V.
It is added to the output of the converter 1o via the adder 11, and the capstan motor 5a is rotated so that the heads 2a and 2b run on the recorded track.

This situation will be explained in detail by showing an example of recording on a magnetic tape and a tracking detection circuit.

In FIG. 2, 21 is a track, 22a and 22b are recording positions of tracking signals, 23 is a vector indicating the traveling direction of the head, and 24 is a vector indicating the traveling direction of the magnetic tape 1. FIG. 9 shows 22a and 22 in FIG.
This is an enlarged view of one of the areas b. 31.
Reference numeral 32 denotes a pilot signal in which signals of the same frequency with less azimuth loss are recorded, and those with the same diagonal lines are recorded by heads with the same azimuth angle. (In the case of the same figure, recording is performed using heads with two azimuth angles.)3
3.34 is a synchronization signal for detecting a signal from a track adjacent to the pilot signal, and those with the same diagonal lines are recorded by heads with the same azimuth angle. 37 is the head gap of the preceding head pair, which moves in the direction of arrow 38. 35 is the helad gap of the trailing head pair, which moves in the direction of arrow 36. The head width of the head gap 37 of the preceding head pair 2a, 2b is set wider than the track width in order to reliably detect the pilot signal.

In the tracking detection circuit 13 of FIG. 10, the output signal of the head 2a+2b is received from the signal line 91, a pilot signal is selected by the low-pass filter 131,
Further, a synchronization signal detection circuit 136 detects a synchronization signal on the track. The pilot signal filtered by the low-pass filter 131 is rectified and detected by the rectifier circuit 132. The synchronizing signal detection circuit 136 can be configured with a bandpass filter and a comparator, or can be configured to digitally detect the reproduced signal frequency. For example, when the head gap passes through the position shown in FIG. 9, the synchronization signal 33a in that track is detected by the head gap 37. The timing circuit 137 generates a pulse twice, at the moment the head detects the synchronization signal and once a certain period of time later.

The first pulse is supplied to the sample hold 133 and the second
The second pulse is supplied to sample hold 134.

When the first pulse is generated, the head gap 37
is reproducing the pilot signal of the adjacent track on the right side in the direction of travel, and the second pulse is generated at the same time as the helad gap 37 is reproducing the pilot signal of the adjacent track on the left side in the direction of travel.

Since the crosstalk signal from the adjacent track is proportional to the amount of head protrusion into the corresponding track, sample hold 133. At 134, voltages proportional to the amount of protrusion of the head to the right and left tracks in the direction of travel are sampled and held, respectively. The subtracter 135 calculates the voltage difference, and as a result, a voltage proportional to the difference between the positions of the track center and the helad gap center is outputted to the output line 92. By controlling the signal on the output line θ2 to zero, the head can be brought onto the track.

Problems to be Solved by the Invention In such conventional technology, when a pair of heads is used, one of which is used as a pre-reading head and the other is used as an after-recording head that records later, severe requirements are placed on head mounting accuracy. become. For example, 3 in Figure 9
If the head is installed so as to have the head gap position as shown in 5, when this head is used as an after-recording head, many of the preceding tracks will be overwritten. For example, in the case where only part of a track is rewritten, the rewritten part becomes a pattern that is extremely shifted, causing a problem that the next time it is played back, it will not be played back correctly.

Therefore, in order to solve such problems, there has been a problem in that extremely high head mounting accuracy is required.

The present invention has been made in view of this problem, and when a pair of heads is used, one of which is used as a pre-reading head and the other as an after-recording head, even if the mounting accuracy of the heads is somewhat poor, the linearity of the track will be impaired. The purpose of this invention is to provide a magnetic recording/reproducing device that will never cause problems.

Means for Solving the Problems In order to solve the above-mentioned problems, the magnetic recording and reproducing apparatus of the present invention as claimed in claim 1 of the present application is characterized in that a tracking signal for detecting a tracking position is formed on a magnetic tape by crosstalk from adjacent tracks. a rotating cylinder to which at least two pairs of heads are attached, a first pair of heads for recording and reproducing in advance and a second pair of heads for recording and reproducing subsequently, using a magnetic tape to be recorded on the recorded tracks; a driving means for running the magnetic tape; and a running position relative to the track of the head pair that is playing back by detecting a tracking signal recorded on a trunk on the magnetic tape from a playback signal of one of the two head pairs. a first tracking detection circuit that outputs a
a travel control circuit that controls the travel of the drive means using the output of the tracking detection circuit; and a travel control circuit that controls the travel of the drive means using the output of the tracking detection circuit; a second tracking detection circuit that detects a tracking signal recorded on a track on a magnetic tape and outputs a running position of the head pair with respect to the track; a storage circuit that holds an output of the second tracking detection circuit; The recording head is configured to include an adder that applies the output of the storage circuit to the first tracking detection circuit when recording is performed with the second pair of heads.

Further, the magnetic recording/reproducing apparatus of the present invention according to claim 2 uses the same magnetic tape, and has a first pair of heads for recording and reproducing in advance and a second pair of heads for recording and reproducing subsequently. a rotating cylinder to which a pair of heads are attached; a drive means for running the magnetic tape; and a pair of heads that detects and reproduces a tracking signal recorded on a track on the magnetic tape from reproduction signals of the two head pairs. a tracking detection circuit that outputs a running position with respect to the track; a head pair discrimination circuit that outputs which of the two head pairs is currently playing; and a head pair discrimination circuit that outputs which of the two head pairs is currently playing, and one of the two head pairs determined by the output of the head pair discrimination circuit. a first storage circuit that recognizes that the other of the two head pairs is playing back and stores the output signal of the tracking detection circuit at that time; and an output of the head pair discrimination circuit that indicates that the other of the two head pairs is playing back. a second storage circuit that recognizes this and stores the output signal of the tracking detection circuit at that time; a travel control circuit that controls the travel of the drive means using the output of the first storage circuit; The present invention operates as a device equipped with an adder that applies the output of the second storage circuit to the tracking detection circuit when recording is performed using the second pair of heads. , the tape run is controlled by one of the two head pairs so that the head pair traces the track center, and the head and track information is determined from the playback signal of the head pair that is not used to detect the tracking signal. In addition to the control loop of the head pair that detects and stores the tracking voltage that indicates the position, and performs tracking to cancel that voltage during after-recording, the trace of the head pair that performs tracking is intentionally shifted, so that the recording head is at the desired track center position. Works to trace.

Embodiment Below, a magnetic recording and reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram of a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is an example of a magnetic tape on which tracking signals described in the conventional example are recorded, and FIG. A diagram showing a recording example and the running of the head, Figure 4 is the first
FIG. 2 is a diagram illustrating a configuration example of a memory circuit in the figure.

Note that the same numbers are used for components that operate in the same way as in the conventional example.

In FIG. 1, 1 is a magnetic tape, 2a and 2b are a first pair of heads that sequentially record and reproduce tracks from each other, 3a,
3b is a second head pair installed in a recording/reproducing position temporally delayed from the first head pair 2a, 2b;
4 is a rotary cylinder to which the heads 2a, 2b+3a+3b are attached; 9a+9b is a reel around which the magnetic tape 1 is wound; 8a, 8b are bosses forming the running path of the magnetic tape 1); 5a, 5b are A capstan motor and a capstan shaft are used to run the magnetic tape 1, 6 is a pinch roller, and 7 is an FGl that outputs a signal with a frequency proportional to the number of rotations of the capstan motor 5a.
10 is an F/v converter, 13 is a tracking detection circuit for detecting a tracking detection signal, 11 is an adder, and 12 is a drive circuit for driving the capstan motor 5a based on the output of the adder 11. Further, 17 is a second head pair 3a.

3b is a tracking detection circuit for detecting a tracking detection signal from the reproduction signal of the same pair when no recording operation is performed; 19 is a controller that instructs whether or not to perform after recording; and 16 is a controller 19 that does not instruct after recording. A memory circuit 18 stores the output signal of the tracking detection circuit 17; a switch 18 switches whether or not to transmit the output signal of the memory circuit 16 according to a command from the controller 19; Tracking circuit 13 for output
This is an adder for adding to the output of .

The operation of the magnetic recording/reproducing apparatus configured as described above will be described below with reference to the drawings.

First, in FIG. 1, FG7. F/V converter 10
．． The drive circuit 12 rotates the capstan motor 5a at a substantially constant rotation. Pinch roller 6 and capstan shaft 5b
The rotational force of the capstan motor 5a, which rotates at a constant rotation, is applied to the magnetic tape 1, causing it to run at a nearly constant speed. The tracking detection circuit 13 detects the first pair of heads 2a, 2.
The relative position between the running position of the head b and the recorded track is detected and added to the output of the F/V converter 10 via the adder 11, so that the first head pair 2a, 2b runs on the recorded track. The capstan motor 5a is rotated. The tracking detection circuit 13 is the first one shown in the conventional example.
The configuration is the same as that in Figure 0 and operates in the same way.

In the above, the capstan shaft 5b1, the capstan motor 5a1, and the pinch roller 6 operate as driving means for running the magnetic tape 1, and the FG7° F/V converter 10. Adder 11. The drive means 12 operates as a travel control circuit.

The controller 19 issues a command for normal playback mode or after-recording mode. When the controller 19 instructs the normal reproduction mode, the switch 18 is set to the OFF state, but the storage circuit 16 operates to always store the tracking detection output of the tracking detection circuit 17.

This storage operation may be performed in synchronization with the rotation of the rotary cylinder 4, in synchronization with the operation of the tracking detection circuit 17, or by a command from the controller 19. In normal playback mode, which is not after-recording, the first head pair 2a, 2b whose position is controlled via the tracking detection circuit 13 traces approximately the center of the track. Also, the second head pair 3a, 3
The position of b with respect to the track is determined by the trunking detection circuit 17.
and stored in the memory circuit 16.

Therefore, in normal playback mode, the first head pair 2a
, 2b trace the center of the track, and the position of the second head pair 3 al 3 b with respect to the track is stored in the storage circuit 16. Next, when the controller 19 changes from the normal playback mode to the after-recording state, the storage circuit 16 stops updating the data in response to the change to instruct after-recording, and the switch 18 switches the storage circuit 16 to the after-recording state. Adder −
14.

In the after-recording, the first pair of heads 2a and 2b that precedes are reproduced while the second head pair 3al3b that follows is recorded.

In the embodiment of FIG. 1, the output of the storage circuit 16 is
The signal is added to the output of the tracking detection circuit 13 via the following. The control loop operates such that the output of adder 14 is zero. Therefore, the first pair of heads 2a, 2b is controlled so that the second pair of heads 3a, 3b is forcibly displaced in the direction opposite to the displacement with respect to the track center in the normal reproduction mode.

As a result, the travel of the first head pair 2a, 2b is offset so that the second head pair 3 at 3 b passes approximately through the center of the track to be recorded.

This situation is shown using FIG. 37 represents the head gap of either of the first head pair 2a, 2b that precedes, and 35 represents the head gap of either of the second head pair 3a, 3b that follows.

Since the output of the storage circuit 16 is applied to the control loop of the first head pair 2 al 2 b via the adder 14, the gap of the preceding first head pair 2 al 2 b runs offset from the track center; The trajectories of the second pair of heads 3a and 3b that follow come to overlap two tracks. FIG. 3 shows an example in which the leading head pair 2a, 2b has a width wider than the track, and the head width of the trailing second head pair 3a, 3b is approximately equal to the track width. .

As described above, the deviation of the head from the track during after-recording, which was a problem in the conventional example, is resolved.

Next, a configuration example of the memory circuit 16 will be described.

FIG. 4 is a diagram showing a specific example of the structure of the memory circuit 16 used in the embodiment of FIG. 1. Components that perform the same operations as in FIG. 1 are given the same numbers. In the figure, 161 is an A/D converter that converts analog values to digital values, 162 is a memory circuit with the same number of bits as the A/D converter 161, and 163 is a D/A converter that converts digital values to analog values. . Next, the operation will be explained.

The output signal voltage of the tracking detection circuit 17 is converted into a digital value by an A/D converter 161. This digital value is transferred to the memory circuit 1 by the output of the controller 19.
62. D/A converter 163 converts the digital value output from memory circuit 162 into an analog voltage. That is, the storage circuit 16 is the tracking detection circuit 1
The output signal voltage of 7 is memorized and output.

When the controller 19 instructs after-recording, the memory circuit 162 is configured not to store the output signal from the A/D converter 161, and holds the voltage indicating the relative position of the head and track during normal playback. During this after-recording, switch 18
A voltage indicating the relative position of the second head pair 3a+3b and the track during normal playback is applied to the control loop of the leading first head pair 2 at 2 b, and the trailing second head pair 3 al 3 b The running of the magnetic tape is controlled so that it traces the center of the magnetic tape.

Therefore, the operation as described in the embodiment of FIG. 1 is ensured.

Note that although the above explanation has been given using an example of a digital memory, it can also be realized using an analog sample-and-hold circuit that can obtain sufficient hold characteristics.

Next, other embodiments of the present invention will be described.

FIG. 5 is a configuration diagram of a magnetic recording/reproducing apparatus showing a second embodiment of the present invention, FIG. 6 is a diagram showing an example of the configuration of the storage circuit in FIG. 5, and FIG. 7 is an operating waveform diagram thereof. be.

In FIG. 5, 1 is a magnetic tape, 2a and 2b are a first pair of heads that sequentially record and reproduce tracks from each other, and 3
a and 3b are a second pair of heads installed at positions for recording and reproducing temporally behind the first pair of heads 2a and 2b; 4 is a rotary cylinder to which heads 2a, 2b + 3a and 3b are attached; 9a and 9b are A reel on which the magnetic tape 1 is wound; 8a and 8b are bosses forming a running path for the magnetic tape 1; and 5a and 5b are a capstan motor and a capstan motor for running the magnetic tape 1, respectively. 4t% 6 is a pinch roller, 7 is an FG that outputs a signal with a frequency proportional to the rotation speed of the capstan motor 5a, 10 is an F/V converter, 13 is a tracking detection circuit for detecting a tracking detection signal, 11
12 is an adder, and 12 is a drive circuit that drives the capstan motor 5a based on the output of the adder 11. Further, 130 is a head pair discrimination circuit that outputs a signal indicating which head pair, the first head pair 2a, 2b or the second head pair 3al3b, is reproducing, and 15 is the preceding first head pair 2a, 2b. 16 is a second head pair 3a for tracking.

3b is a storage circuit that stores the output of the tracking detection circuit I3 during playback; 18 is a switch that switches whether or not to transmit the output of the storage circuit 16 by the +h command of the controller 19; This is an adder for adding the transmitted output of the storage circuit 16 to the output of the tracking circuit 13.

The head pair discrimination circuit 130 generates a discrimination signal based on a crystal oscillator (not shown) in a cylinder control circuit that controls the rotation of the rotary cylinder 4 or a PG generated in synchronization with the rotation of the rotary cylinder 4. It is configured like this.

The operation of the magnetic recording/reproducing apparatus configured as described above will be described below with reference to the drawings.

In FIG. 5, parts that perform the same functions as those in the embodiment of FIG. 1 are given the same numbers.

In FIG. 5, PG7. The F/V converter 10 and the drive circuit 12 rotate the capstan motor 5a at approximately constant rotation. The pinch roller 6 and the capstan shaft 5b apply the rotational force of the capstan motor 5a, which rotates at a constant rotation, to the magnetic tape 1, causing it to run at a nearly constant speed.

The controller 19 issues a command for normal playback mode or after-recording mode. When the controller 19 commands the normal playback mode, the switch 18 is set to the off state.

Further, the head pair discrimination circuit 130 outputs the signal shown in FIG. 7A. The signal shown in FIG. 7A is a signal synchronized with the rotation of the rotating cylinder 4 shown for reference, and one period of this signal corresponds to one rotation of the rotating cylinder 4. Therefore, the signal in FIG. 7A is a signal with a cycle of two revolutions of the rotary cylinder 4, and the high level period of the signal in FIG. 7A is for the first head pair 2a.

2b is in contact with the magnetic tape 1, and the low level period represents a period in which the second head pair 3a, 3b is in contact with the magnetic tape 1. That is, the signal in FIG. 7A shows the head pair in contact with the magnetic tape.

The signal shown in FIG. 7A is generated in a cylinder side control circuit for controlling the rotation of the rotary cylinder 4 based on a crystal oscillator (not shown) or a PG generated in synchronization with the rotation of the rotary cylinder.

The tracking detection circuit 13 detects the heads 2a, 2b, 3a.
, 3b is used to detect the tracking signal of each track. Since the tracking detection circuit 13 has the same configuration as the conventional example shown in FIG. 10 and operates in the same way, the sample pulse to the sample hold circuit 134 is generated twice for each trace of each head, and the sample pulse in FIG. 1 as shown in
It becomes a pulse of 8 rotations. The tracking detection circuit 13 outputs both the detected tracking signal and the pulses shown in FIG.

The storage circuit 15 gates the two signals shown in FIG. 7 during the high level period of the signal shown in FIG. do. Using this output, the relative position between the traveling position and the recorded track is detected and added to the output of the F/V converter 10 via the adder 11, so that the first head pair 2a, 2b can detect the relative position of the recorded track. The capstan motor 5a is rotated so as to run. When the controller 19 instructs normal playback, the switch circuit 18 is off and the first head pair 2a, 2b runs in the center of the track.

At the same time, when the controller 19 instructs normal playback, the storage circuit 16 gates the two signals shown in FIG. 7 during the low level period of the signal shown in FIG. The tracking signal output from the tracking circuit 13 is stored. That is, the storage circuit 16 stores the relative positions of the second head pair 3a, 3b and the track using the same tracking detection circuit 13 used for tracking the first head pair 2a, 2b. .

In normal playback mode (not after recording),
The first head pair 2 al 2 b whose position is controlled via the tracking detection circuit 13 traces approximately the center of the trunk. Also, the second head pair 3a, 3b
The position with respect to the track is detected by the tracking detection circuit 13 and stored in the storage circuit 16.

Therefore, in normal playback mode, the first to rad pair 2
a, 2b trace the center of the track, and the position of the second head pair 3 al 3 b with respect to the track is stored in the storage circuit 16.

Next, when the controller 19 changes from the normal playback mode to the after-recording state, the memory circuit 16
In response to entering the after-recording state, data updating is stopped, and the switch 18 is switched to transmit the output of the memory circuit 16 to the adder 14.

In after-recording, the first pair of heads 2a, 21) that precedes is reproduced while the second pair of heads 3a, 3b that follows are recorded.

In the embodiment of FIG. 5, the output of the storage circuit 16 is
The signal is added to the output of the tracking detection circuit 13 via the following. The control loop operates such that the output of adder 14 is zero. Therefore, the first pair of heads 2a+2b is controlled so as to be forcibly displaced in the opposite direction to the direction in which the second pair of heads 3a, 3b is displaced from the center of the track in the normal reproduction mode.

As a result, as in the embodiment of FIG.
The travel of the first head pair 2 al 2 b is offset so that a+3b passes approximately through the center of the track to be recorded.

Furthermore, a first head pair 2a, 2b for tracking
The second head pair 3 al
Since the storage circuit 16 stores the relative position of the head 3b and the track, accurate head position correction without variations between circuits is possible.

As described above, the deviation of the head from the track during after-recording, which was a problem in the conventional example, is resolved.

Next, a configuration example of the memory circuit 16 used in the embodiment shown in FIG. 5 will be described.

FIG. 6 is a diagram showing a second configuration example of the memory circuit 16.

Components that perform the same operations as in FIG. 5 are given the same numbers. In the figure, 161 is an A/D converter that converts an analog value to a digital value, 162 is a memory circuit with the same number of bits as the A/D converter 161, 163 is a D/A converter that converts a digital value to an analog value, 1
65. 166 is an inverter, 164 and 151 are AND
The circuit 152 is a sample and hold circuit.

Next, the operation will be explained.

The head pair discrimination circuit 130 converts the signal shown in FIG.
Output is performed in the same manner as in the embodiment shown in the figure. Tracking detection circuit 1
3 are heads 2a, 2b, 3a, similar to the embodiment shown in FIG.
, 3b, and since the tracking detection circuit 13 has the same configuration as the conventional example shown in FIG. 10 and operates in the same way, the sample pulse to the sample hold circuit 134 The pulses are generated twice for each trace of the head, resulting in eight pulses per revolution as shown in Figure 7. The tracking detection circuit 13 outputs both the detected tracking signal and the pulses shown in FIG. Since the AND circuit 151 performs the logical product of the two signals shown in FIG. 7A, the output of the AND circuit 151 is as shown in FIG.

The sample and hold circuit 152 samples and holds the tracking signal output from the tracking detection circuit 13 using the pulse shown in FIG.

Therefore, the sample and hold circuit 152 holds the tracking signal output of the first head pair 2a, 2b.

Similar to the embodiment shown in FIG. 5, this output can be used to control the first head pair 2a12b to trace the center of the track during normal playback.

Also, the output signal voltage of the tracking detection circuit 13 is
The converter 161 converts it into a digital value. During normal playback, the controller 19 outputs a low level voltage,
When the controller 19 is at low level, the ND circuit 164
The head pair discrimination circuit 130 distinguishes between the second head pairs 3a, 3
Inverter 185.16 when low level output indicating b
6t4, and the tracking detection pulse (Figure 7) under that condition is passed. That is, the AND circuit 164 outputs sample pulses during normal playback of the second head pair 3a, 3b shown in FIG. 7E.

Therefore, only during normal playback, the second head pair 3a, 3b
The tracking detection signals of the track and the track are digitized by the A/D converter 161 and stored in the memory circuit 182. D/A converter 163 is memory circuit 162
Converts the digital value output by the converter into an analog voltage. That is, the storage circuit 16 stores and outputs the output signal voltage of the tracking detection circuit 13 during reproduction of the second head pair 3a, 3b.

When the controller 19 sets the output to high level and instructs after-recording, the AND circuit 164 cuts off the sample pulse and the memory circuit 162 no longer stores the output signal from the A/D converter 161. A voltage indicating the relative position of the two head pairs 3a, 3b and the track is held. During this after-recording, the second
A voltage indicating the relative position of the head pair 3a, 3b and the track is applied to the control loop of the first head pair 2a, 2b, and the second head pair 3a, 3b follows the magnetic tape so that it traces the center of the track. The travel of the vehicle is controlled.

Therefore, the operation as described in the embodiment of FIG. 5 is ensured.

In the above description of the embodiments shown in FIGS. 1 and 5, an example will be described in which, during normal playback, the leading head pair controls the running of the magnetic tape, and the trailing head pair detects the positional error between the track and the head pair. However, it goes without saying that the same effect can be obtained by conversely using a method in which the trailing head pair controls the running of the magnetic tape and the preceding head pair detects the positional error between the track and the head pair.

Effects of the Invention As described above, according to this embodiment, when performing after-recording using a pair of two heads, the leading head performs tracking control during normal playback, and the tracking state of the trailing head and track at that time is stored in the storage circuit. By adding the tracking state of the trailing head and controlling the leading head during after-recording, the writing position of the trailing head can be controlled to a desired position.

Therefore, there is no need for extreme accuracy in the mounting positions of the leading head and the trailing head, and it is possible to obtain an extremely large effect of significantly improving productivity.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing one embodiment of the present invention, Fig. 2, Fig. 3
The figure shows an example of a recorded magnetic tape.
FIG. 5 is a configuration diagram showing another embodiment of the present invention; FIG. 6 is a configuration example of the storage circuit in the embodiment of FIG. 5; FIG. The figure is an operational waveform diagram in the embodiment shown in Figure 5, Figure 8 is a configuration diagram for explaining the conventional example, Figure 9 is a diagram of a recording example of the magnetic tape used in the conventional example, and Figure 10 is the conventional example. FIG. 3 is a diagram illustrating a configuration example of a tracking detection circuit in FIG. DESCRIPTION OF SYMBOLS 1... Magnetic tape, 2a, 2b... First head pair, 3a, 3b... Second head pair, 4.
...Rotating cylinder, 5a, 5b+ 6...Driving means, 13...First tracking detection circuit, 7.10°11.12...Travel control circuit, 17...Second tracking detection circuit , 16... memory circuit, 14
．． 18... Adder. Name of agent: Patent attorney Shigetaka Awano and one other person

Claims (2)

[Claims] (1) A device for recording and reproducing a magnetic tape in which a tracking signal for detecting a tracking position by crosstalk from an adjacent track is recorded on a track formed on the magnetic tape, and the device records and reproduces the magnetic tape in advance. First thing to do
a rotary cylinder to which at least two head pairs are attached, a second head pair for subsequent recording and reproduction; a driving means for running the magnetic tape; a first tracking detection circuit that detects a tracking signal recorded on a track on the magnetic tape from a playback signal and outputs a traveling position of a head pair that is playing back with respect to the track; and an output of the first tracking detection circuit. a travel control circuit that uses the drive means to control the travel of the drive means, and a reproduction signal of a head pair that is not used for tracking detection of the first tracking detection circuit of the two head pairs, and records on a track on the magnetic tape. a second tracking detection circuit that detects the tracked tracking signal and outputs the traveling position of the head pair with respect to the track; a storage circuit that holds the output of the second tracking detection circuit; and a storage circuit that records with the second head pair. 1. A magnetic recording and reproducing apparatus comprising: an adder that applies an output of the storage circuit to the first tracking detection circuit when performing tracking detection. (2) A device for recording and reproducing a magnetic tape in which a tracking signal for detecting a tracking position by crosstalk from an adjacent track is recorded on a track formed on the magnetic tape, and the device records and reproduces the magnetic tape in advance. First thing to do
a rotary cylinder to which at least two head pairs are attached, a second head pair for recording and reproducing, a driving means for running the magnetic tape; a tracking detection circuit that detects a tracking signal recorded on the upper track and outputs the traveling position of the head pair that is playing back with respect to the track; a head pair discrimination circuit that outputs which of the two head pairs is playing back; a first storage circuit that recognizes that one of the two head pairs is playing back based on the output of the head pair discrimination circuit and stores the output signal of the tracking detection circuit at that time; and the head pair discrimination circuit. a second memory circuit that recognizes that the other head pair of the two head pairs is reproducing based on the output of the head pair and stores the output signal of the tracking detection circuit at that time; and an output of the first memory circuit. and an adder that applies the output of the second storage circuit to the tracking detection circuit when recording with the second pair of heads. A magnetic recording/reproducing device characterized by: