JP2002197757A - Magnetic recording and reproducing device and rotary drum drive controlling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of electrostatic destruction of an MR head, in a magnetic recording and reproducing device provided with the MR head. SOLUTION: When a system controller 11 detects the time when a cassette case is inserted by the detection signal from a cassette sensor 15, the system controller 11 rotates a drum motor 33 via a motor driver 14 and detects the position of a reproducing magnetic head by the detection signal from an FG 31 and a PG 32 to control the drum motor 33 so that the reproducing magnetic head is stopped in the position that does not face toward the direction of the insertion port of the cassette case. When the system controller 11 detects the time when the cassette case is ejected by the cassette sensor 15, the system controller 11 also controls the rotary drive of the drum motor 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus for recording and reproducing a signal on and from a magnetic tape, and a method for controlling the driving of a rotary drum in the apparatus. The present invention relates to a magnetic recording / reproducing apparatus used and a method of controlling driving of a rotary drum in the apparatus.

[0002]

2. Description of the Related Art In recent years, in a magnetic recording / reproducing apparatus for recording and reproducing data using a magnetic tape, it is desired to further improve the recording density with an increase in the amount of information to be handled. As a magnetic head,
Instead of the conventional inductive head, MR (Magneto Re
It is essential to use a sistive (magnetoresistive effect) head. An MR head is a magnetic head that reads a signal recorded on a magnetic recording medium using a magnetoresistance effect of an MR element, and has a high signal detection sensitivity,
Since a large reproduction output can be obtained, the recording track width on the magnetic tape can be easily reduced, the recording density in the linear direction can be increased, and high-density recording and reproduction can be performed.

As a recording / reproducing apparatus using a magnetic tape, a helical scan system for recording and reproducing signals by helically winding a magnetic tape around a drum device which rotates together with a magnetic head provided on the outer periphery. It has been known. In this helical scan type recording / reproducing apparatus, the magnetic head slides on the running magnetic tape at a high speed to record and reproduce signals, so that the relative sliding speed between the magnetic tape and the magnetic head is high. An improvement in the data transfer rate has been realized.

FIG. 8 shows a schematic configuration example of a magnetic recording / reproducing apparatus using a helical scan system. A magnetic recording / reproducing apparatus 81 shown in FIG.
2 is used as, for example, a data storage device of a computer device or a recording device of a video signal or an audio signal. The magnetic recording / reproducing apparatus 81 includes a reproducing magnetic head R for reading a signal from a magnetic tape 82.
5 and R6 and a recording magnetic head W5 for writing
, A capstan 84 and a pinch roller 85 for running the magnetic tape 82 at a predetermined speed, and a plurality of tape guides (indicated as TG in the figure) 86a for guiding the running of the magnetic tape 82 , 86
b, 86c, 86d and 86e.
The cassette case 87 inserted in the magnetic recording / reproducing device 81 includes a supply reel 87a for the magnetic tape 82 and a take-up reel 87b.

The drum device 83 has a cylindrical shape having a smooth outer peripheral surface as a whole, and includes, for example, an upper rotating drum and a fixed drum fixed coaxially with the rotating shaft. Heads R5 and R6,
The recording magnetic heads W5 and W6 are mounted on the outer peripheral surface of the rotating drum so that a sliding portion with the magnetic tape 82 protrudes. The reproducing magnetic heads R5 and R6 are MR heads, and the recording magnetic heads W5 and W6
Is a so-called inductive type magnetic head in which a coil is wound around a magnetic core having a magnetic gap, for example.

In the magnetic recording / reproducing apparatus 81, when recording and reproducing of the magnetic tape 82 are performed, the cassette case 87 is moved from below in FIG.
And is held by a cassette mechanism (not shown), approaches the drum device 83, and is lowered to a position where the pinch roller 85 and the TGs 86a to 86e are installed. Thereafter, the rotating drum of the drum device 83 rotates and the loading operation of the magnetic tape 82 is started, and the pinch roller 85 and the TGs 86a to 86e move in the direction of arrow D in the drawing, so that the magnetic tape 82 is guided. Then, it is helically wound around the drum device 83. Then, the capstan 84 and the take-up reel 8
7b rotates, the magnetic tape 82 runs,
The rotation of the rotary drum causes the reproducing magnetic heads R5 and R6 or the recording magnetic heads W5 and W6 to scan the magnetic tape 82 obliquely, thereby starting to read or write signals.

In the example of the magnetic recording / reproducing apparatus 81, in the drum device 83, a rotating magnetic drum R5, a recording magnetic head W5, a reproducing magnetic head R6, and a recording magnetic head W6 are arranged in this order on the outer periphery. Are mounted in a state of being shifted from each other by 90 ° about the rotation axis.
In such a case, reading or writing to the magnetic tape 82 is performed twice, that is, for two tracks during one rotation of the rotating drum. As another mounting method of each magnetic head, an adjacent track or a track separated by several tracks is simultaneously slid.
In some cases, a plurality of reproducing magnetic heads and a plurality of recording magnetic heads are mounted at positions 180 ° opposite each other about a rotation axis. In this case, it is possible to simultaneously read or write signals on a plurality of tracks on the magnetic tape 82 by each combination of the reproducing or recording magnetic heads while the rotating drum makes one rotation.

[0008]

However, in general, MR
The head has a property that it is susceptible to static electricity and heat as compared with an inductive head. Here, FIG.
ESD (Electrostatic Discharge) in R head
4 shows the results of measuring the breakdown voltage. FIG. 9A shows an AMR (Anis
(otropic Magneto Resistive) head, (b) GMR
(Giant Magneto Resistive) The measurement result about a head is each shown.

In the measurement values shown in FIG. 9, the HBM (Human Body Model) is used in the measurement of the ESD breakdown voltage.
This shows the relationship between the voltage applied to the device and the resistance when discharging is performed with a resistance value of Ω. According to this, ES
D breakdown voltage is 230-240V for AMR head
And in the case of a GMR head, about 30 to 40 V. On the other hand, the charging voltage of an insulating object (plastic, nylon, vinyl, etc.) under a normal environment easily reaches several kV or more due to friction, contact, induction, etc. Exceed.

The conventional cassette case 87 is often formed of a high-resistance synthetic resin material. Such a cassette case 87 is rubbed with, for example, artificial fiber packing material or gloves in the process of handling by a user, or is inserted into the magnetic recording / reproducing device 81 or the magnetic tape drum device 83. Static electricity is easily charged due to friction with various parts during the loading operation and the unloading operation. The charging voltage of the synthetic resin material used for the cassette case 87 is, for example, about 1
1500 to 20 in the case of ABS resin of 0 ¹⁶ Ω / sq
At a voltage of 00 V or more, the half-life is 3 minutes or more. Since the value of this charging voltage is much higher than the withstand voltage of the MR head, and the half-life is long, the charging once generated does not readily attenuate. For this reason, when the cassette case 87 charged with static electricity is inserted into the magnetic recording / reproducing device 81 and the magnetic tape 82 comes into contact with the MR head, a large amount of current flows through the MR head via the magnetic tape 82, M
There is a risk that the R head may be damaged by electrostatic discharge.

FIG. 10 conceptually shows the flow of electric charges when the magnetic tape 82 and the MR head come into contact with each other. FIG. 10 shows an enlarged view of a contact portion between the drum device 83 and the magnetic tape 82 in the magnetic recording / reproducing device 81. In the conventional magnetic recording / reproducing apparatus 81, when the magnetic tape 82 is loaded, the stop position of each magnetic head is not particularly determined. Therefore, the cassette case 87 is inserted and the magnetic tape 82 is operated by the operation of the thread mechanism. When the loading of the drum device 83 is performed, as shown in FIG. 10, the magnetic tape 82 may first contact the reproducing magnetic head R5. Further, for example, even when the cassette case 87 is inserted and the magnetic tape 82 is unloaded, the winding of the magnetic tape 82 may be deflected due to insufficient winding, and may be outside the cassette case 87. May be in contact with the magnetic tape 82 depending on the stop position of the reproducing magnetic head R5.

In such a case, if the inserted cassette case 87 is charged with static electricity, as shown in FIG. 10, the cassette case 87 passes from the surface of the magnetic tape 82 through the reproducing magnetic head R5 in contact therewith. Charge 1 leading to device ground
01. Therefore, at the moment when the magnetic tape 82 comes into contact with the reproducing magnetic head R5, a large amount of current flows to the MR element, and the MR element is electrostatically damaged, so that it becomes impossible to read a signal.

FIG. 11 shows a state where a user's hand is inserted into the magnetic recording / reproducing apparatus 81. FIG.
As shown in FIG. 7, in the magnetic recording / reproducing apparatus 81, an insertion port 88 of a cassette case 87 provided on a front panel 88 is provided.
Through "a", the user's hand, finger, stick, or the like may be inserted due to unexpected behavior by the user. Such an object inserted from the outside may be charged with static electricity. At this time, the stop position of the reproducing magnetic head R5 is set to the insertion port 88 as shown in FIG.
In the state facing the a side, the inserted finger or stick may come into contact with the reproducing magnetic head R5. Also in this case, a large amount of current flows to the MR element at the moment when the magnetic head comes into contact with the reproducing magnetic head R5, and electrostatic breakdown occurs.

As described above, the conventional magnetic recording / reproducing apparatus 8
1, when the cassette case 87 is inserted, the magnetic tape 82 is subsequently loaded, and after the cassette case 87 is ejected, the reproducing magnetic head R5 having the MR element is provided.
And the stop position of R6 may cause electrostatic destruction of the MR element.
MR as a magnetic head of a magnetic recording / reproducing device 81 using
Using the head was difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and has as its object to prevent electrostatic breakdown of an MR head in a magnetic recording / reproducing apparatus having the MR head.

Another object of the present invention is to prevent occurrence of electrostatic breakdown of an MR head in a method for controlling the driving of a rotary drum in a magnetic recording / reproducing apparatus having an MR head.

[0017]

According to the present invention, there is provided a magnetic recording / reproducing apparatus for recording / reproducing a signal on / from a magnetic tape, the reproducing magnetic head using a magnetoresistive element. A rotating drum comprising:
Drum rotation driving means for driving the rotation drum,
At the time of insertion and ejection of the cassette case in which the magnetic tape is wound and stored, the rotating drum is rotated so as to stop at a position where the reproducing magnetic head does not face in the direction of the insertion opening of the cassette case. And a rotation control means for controlling the drum rotation drive means.

In such a magnetic recording / reproducing apparatus, the rotation drum is rotated at the time of insertion and ejection of the cassette case under the control of the rotation control means so that the reproducing magnetic head does not face the insertion opening of the cassette case. Therefore, when the inserted cassette case is charged with static electricity, it is possible to prevent the magnetic tape and the reproducing magnetic head from first contacting each other to cause discharge. Further, even if an unexpectedly charged substance is inserted inside the cassette case and comes into contact with the rotating drum after the cassette case is discharged, it is possible to prevent the discharge through the reproducing magnetic head. This makes it possible to prevent electrostatic damage of the magnetoresistive element.

Further, according to the present invention, there is provided a method for controlling driving of a rotary drum in a magnetic recording / reproducing apparatus for recording and reproducing a signal on / from a magnetic tape, comprising the steps of: Detecting the discharge time, rotating the rotating drum having the reproducing magnetic head using the magnetoresistive element, and stopping at a position where the reproducing magnetic head does not face in the direction of the insertion opening of the cassette case. A method for controlling driving of a rotating drum is provided.

In such a rotary drum drive control method,
When the cassette case is inserted and ejected, the rotating drum is rotated to stop the playback magnetic head so that it does not face the insertion slot of the cassette case. In addition, it is possible to prevent the magnetic tape and the reproducing magnetic head from coming into contact with each other for the first time and causing discharge. Further, even if an unexpectedly charged substance is inserted inside the cassette case and comes into contact with the rotating drum after the cassette case is discharged, it is possible to prevent the discharge through the reproducing magnetic head. This makes it possible to prevent electrostatic damage of the magnetoresistive element.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 2 shows a schematic configuration example around a magnetic tape traveling system in a magnetic recording / reproducing apparatus of the present invention.

A magnetic recording / reproducing apparatus 1 shown in FIG. 2 uses a magnetic tape 2 as a recording medium and is used as, for example, a data storage device of a computer device or a recording device of a video signal or an audio signal. The running system of the magnetic tape 2 in the magnetic recording and reproducing apparatus 1 includes a drum device 3 having a magnetic head for writing and reading signals to and from the magnetic tape 2, a capstan 4 for running the magnetic tape 2 at a predetermined speed, and It comprises a pinch roller 5 and a plurality of tape guides (indicated as TG in the figure) 6a, 6b, 6c, 6d and 6e for guiding the running of the magnetic tape 2. The cassette case 7 inserted into the magnetic recording / reproducing apparatus 1 has a supply reel 7a and a take-up reel 7b for the magnetic tape 2, and is held by a cassette mechanism 8 which is movable by driving a motor (not shown).

The drum device 3 has a cylindrical shape having a smooth outer peripheral surface as a whole, and includes, for example, an upper rotating drum (not shown) and a fixed drum (not shown) fixed coaxially with the rotating shaft. The rotating drum is driven to rotate by a drum motor (not shown) provided in the fixed drum. Further, the rotating drum is provided with a reproducing magnetic head (not shown) for detecting a recording signal of the magnetic tape 2 and a recording magnetic head (not shown) for writing a signal. The reproducing magnetic head is an MR head using a magnetoresistive effect (MR) element as a head element, and contacts a magnetic tape 2 to detect a change in the resistance value of the MR element according to a recording signal. Then, the recording signal of the magnetic tape 2 is read. The recording magnetic head is a so-called inductive type magnetic head in which a coil is wound around a magnetic core having a magnetic gap, for example. Usually, a plurality of the reproducing magnetic heads and the recording magnetic heads are mounted on a rotating drum as described later.

On the other hand, the capstan 4, the supply reel 7a and the take-up reel 7b are driven to rotate by a capstan motor (not shown). The capstan 4, the supply reel 7a and the take-up reel 7b
Each of them may be rotationally driven by an individual motor.
The pinch roller 5 and the TGs 6a to 6e are provided with a sled motor (not shown) and a driving force generated by the sled motor.
A plurality of gears (not shown) transmitted to 6e constitute a thread mechanism for pulling out the magnetic tape 2 from the inside of the cassette case 7 and winding it around the drum device 3.

In the magnetic recording / reproducing apparatus 1, when recording and reproducing of the magnetic tape 2 are performed, the cassette case 7 is inserted through the insertion port 9 a provided on the front panel 9.
It is inserted into the magnetic recording / reproducing apparatus 1 in the direction of arrow A and is held by the cassette mechanism 8. At this time, the cassette mechanism 8 is automatically moved by being pushed inside by the user, and the cassette case 7 approaches the drum device 3 and is lowered to the position where the pinch roller 5 and the TGs 6a to 6e are installed. You. Thereafter, the loading operation of the magnetic tape 2 is started, and the pinch roller 5 and the TGs 6a to 6e are moved in the direction of the arrow B in the drawing by the driving of the sled mechanism. Helically wound around. The rotation of the capstan 4 and the take-up reel 7b causes the magnetic tape 2 to travel and the rotating drum of the drum device 3 to rotate, so that the recording magnetic head or the reproducing magnetic head obliquely moves on the magnetic tape 2. , The writing or reading of the recording signal is started.

Incidentally, the cassette case 7 used in the magnetic recording / reproducing apparatus 1 is often formed of a high-resistance synthetic resin material. Static electricity is easily charged by being rubbed with materials, gloves, or the like, or being rubbed with various components at the time of insertion into the magnetic recording / reproducing apparatus 1 or at the time of loading operation and unloading operation. When such a cassette case 7 is inserted into the magnetic recording and reproducing apparatus 1 to perform a recording and reproducing operation, the cassette case 7 is inserted and the cassette mechanism 8 is inserted.
When the magnetic tape 2 is loaded onto the drum device 83 by the operation of the sled mechanism, the magnetic tape 2 comes into contact with the outer peripheral surface of the drum device 3. Also, when the cassette case 7 is inserted, the magnetic tape 2 may be bent out of the cassette case 7 due to insufficient winding of the magnetic tape 2 or the magnetic recording / reproducing apparatus 1 Similarly, when vibration is applied from the outside, the magnetic tape 2 may come into contact with the drum device 3.

At this time, if the reproducing magnetic head, which is the MR head of the drum device 3, is stopped in the direction of the insertion opening 9a of the cassette case 7,
When the magnetic tape 2 comes into contact with the drum device 3, the magnetic tape 2 first comes into contact with the reproducing magnetic head. At this time, the cassette case 7 charged with static electricity discharges to the reproducing magnetic head through the magnetic tape 2. Then, electrostatic breakdown of the MR element is caused. Further, after the cassette case 7 is ejected from the magnetic recording / reproducing apparatus 1, an unexpectedly charged substance such as a finger or a stick of a user is inserted into the inside from the insertion port 9a,
Even when this comes into contact with the reproducing magnetic head, the electrostatic breakdown of the MR element occurs similarly to the above.

In the present invention, M generated for such a reason is
To prevent electrostatic breakdown of the R element, the cassette case 7
When the cartridge is inserted and ejected, the rotating drum is rotated to control the stop position so that the reproducing magnetic head does not face the insertion opening 9a of the cassette case 7. This prevents the charged magnetic tape 2 from first contacting the reproducing magnetic head when the cassette case 7 is inserted or when the magnetic tape 2 is subsequently loaded. Since the outer peripheral surface of the drum device 3 is formed of a conductive material and is electrically connected to, for example, a chassis of the device at a ground potential,
The static electricity is discharged through the drum device 3. Further, when an unexpected charged substance is inserted after the cassette case 7 is discharged, the charged substance is prevented from first contacting the reproducing magnetic head.

For such rotational drive control of the rotary drum, a position detecting means for detecting the position of the reproducing magnetic head is required. In the magnetic recording / reproducing apparatus 1 of the present invention, as the position detecting means, for example, in order to control the rotation speed of the rotating drum, an FG (Frequency Generator) and a PG (Pulse Gen.
erator). Here, FIG. 3 shows a schematic configuration example of PG and FG functioning as position detecting means of the reproducing magnetic head.

The FG 31 shown in FIG.
a and the FG sensor 31b.
It is composed of a G magnet 32a and a PG sensor 32b. FG pattern 31a and PG magnet 32a
Is formed on a substrate provided in a fixed drum of the drum device 3, for example, and rotates together with the rotating drum. on the other hand,
The FG sensor 31b and the PG sensor 32b are fixed to a fixed drum. With such a configuration, the FG sensor 31b outputs a number of pulse signals per rotation of the rotating drum as an FG detection signal, and the PG sensor 32b outputs one pulse signal per rotation as a PG detection signal. With the FG detection signal and the PG detection signal, it is possible to know the rotational speed of the rotary drum and the absolute positional relationship between the rotary drum and the magnetic head, respectively, and it is possible to control the rotational speed of the rotary drum. When the position control of the magnetic head is performed, first, the rotating drum is rotated to detect the PG detection signal, and then the FG detection signal is counted up and stopped at a predetermined count number. It is possible to stop at a position facing an arbitrary direction.

Next, FIG. 1 shows a schematic configuration of a drive control system of the rotary drum in the magnetic recording / reproducing apparatus 1. The block diagram shown in FIG. 1 illustrates a case where the magnetic recording / reproducing device 1 is used as a data storage device of the computer device 20. In this case, the computer device 20 is connected to the magnetic recording / reproducing device 1, and when an operation input is performed by a user, a control signal corresponding to the operation input is transmitted to the magnetic recording / reproducing device 1, whereby 1 is controlled.

The control system shown in FIG.
0, a system controller 11 for controlling the system of the entire apparatus according to a control signal from the FG detection signal and P
FG31 and PG32 each outputting a G detection signal,
A drum motor 33 which is a rotation driving means of the rotating drum,
F that amplifies the FG detection signal and the PG detection signal respectively
The G amplifier 12 and the PG amplifier 13, a motor driver 14 for controlling the rotation drive of the drum motor 33 according to a control signal from the system controller 11, and whether or not the cassette case 7 has been inserted into the magnetic recording / reproducing apparatus 1. It is constituted by a cassette sensor 15 for detecting. FG3
1, the PG 32 and the drum motor 33 are provided inside the drum device 3, respectively.

In this control system, the system controller 11 transmits a control signal to the motor driver 14 in accordance with a control signal from the computer device 20, and thereby the drum motor 3 is transmitted through the motor driver 14.
3 to control the rotation and stop operation of the rotating drum. Further, the system controller 11 performs servo control using the FG detection signal and the PG detection signal from the FG 31 and the PG 32, so that the rotation speed of the drum motor 33 can be kept constant at a predetermined speed.

The system controller 11 also controls the driving of a motor for moving the cassette mechanism 8,
Rotational drive control of a capstan motor for driving the capstan 4 and the supply reel 7a and the take-up reel 7b for running the magnetic tape 2, and for moving the pinch roller 5 and the TGs 6a to 6e for guiding the movement of the magnetic tape 2. The rotation drive control of the thread motor is performed.

In this control system, when the position of the magnetic head in the drum device 3 is controlled, the system controller 11 rotates the drum motor 33 while
The G detection signal and the FG detection signal are counted, and the drum motor 33 is stopped at a predetermined count. In the present invention, as described above, in order to prevent the electrostatic breakdown of the MR element used in the reproducing magnetic head, the position of the reproducing magnetic head is controlled when the cassette case 7 is inserted and ejected. . As an example of a detecting means for detecting when the cassette case 7 is inserted and ejected, a cassette sensor 15 which detects insertion and ejection of the cassette case 7 into the magnetic recording / reproducing apparatus 1 by an optical sensor.
Is used.

The cassette sensor 15 includes, for example, a light emitting diode for emitting light for detection and a light receiving element (not shown) for receiving the light, and these guide the cassette case 7 while holding it. The cassette mechanism 8 is provided so as to be opposed to a part of the cassette mechanism 8. With this structure, when the cassette case 7 is inserted into the magnetic recording / reproducing device 1, the cassette mechanism 8 is pushed and moved by the user, and a part of the cassette mechanism 8 is moved from the light emitting diode to the light receiving element. Block light. The system controller 11 monitoring the light detection signal from the light receiving element detects the insertion of the cassette case 7 by blocking the light. When the cassette case 7 is ejected, the insertion slot 9a
The movement of the cassette mechanism 8 in the direction reopens the optical path from the light emitting diode to the light receiving element, so that the system controller 11 detects the ejection of the cassette case 7.

Next, FIG. 4 shows a flowchart of the processing by the system controller 11 from the insertion of the cassette case 7 to the recording or reproducing operation of the magnetic tape 2. In step S401, the cassette case 7 is inserted into the magnetic recording / reproducing apparatus 1, and the light detection signal from the cassette sensor 15 is cut off to detect that the cassette case 7 has been inserted. In step S402, the drum motor 33 is driven to control the position of the reproducing magnetic head, and at the same time, the motor for moving the cassette mechanism 8 is driven to move the cassette mechanism 8 holding the cassette case 7 inside the apparatus. Move to In the position control of the reproducing magnetic head, the FG 31 and the PG 31 are rotated while rotating the drum motor 33 via the motor driver 14.
32, the FG detection signal and the PG detection signal are counted, and the reproducing magnetic head is inserted into the insertion port 9a of the cassette case 7.
Stop the rotating drum so that it does not face the direction. Further, the movement of the cassette mechanism 8 sets the cassette case 7 at a position where recording and reproduction can be performed.

In step S403, the control signal from the computer device 20 is monitored, and if a command signal for starting the recording or reproducing operation of the magnetic tape 2 is received, the process proceeds to step S404. In step S404, the thread motor that moves the pinch roller 5 and the TGs 6a to 6e is driven to load the magnetic tape 2 onto the drum device 3. At this time, the rotating drum is stopped, and the magnetic tape 2 always comes into contact with a portion other than the reproducing magnetic head first on the outer peripheral surface of the drum device 3. Since the outer peripheral surface of the drum device 3 is made of a conductive material, when the magnetic tape 2 is charged with static electricity, the magnetic tape 2 is discharged to the drum device 3 to cause electrostatic breakdown of the MR element of the reproducing magnetic head. Is prevented from occurring. In step S404, before driving the sled motor,
The stop position control of the reproducing magnetic head may be performed again.

Subsequently, in step S405, the drum motor 33 and the capstan motor are driven to rotate, the rotating drum rotates, and the running of the magnetic tape 2 is started, so that recording or reproduction of the magnetic tape 2 is performed. At this time, the magnetic tape 2 comes into contact with the reproducing magnetic head, but since the static electricity has already been discharged, a large current does not flow through the MR element.

Next, FIG. 5 shows a flowchart of the processing by the system controller 11 from the stop of the recording or reproducing operation of the magnetic tape 2 to the ejection of the cassette case 7. At the start of the flowchart shown in FIG. 5, it is assumed that the recording or reproducing operation of the magnetic tape 2 is being performed in the magnetic recording and reproducing apparatus 1. In step S501, the control signal from the computer device 20 is monitored, and if an instruction signal for stopping the recording or reproducing operation of the magnetic tape 2 is received, the process proceeds to step S502. In step S502, the rotation of the drum motor 33 and the capstan motor is stopped, and the rotation of the rotating drum and the running of the magnetic tape 2 are stopped. Step S50
In step 3, the thread motor is driven, and the magnetic tape 2
Of the drum device 3 from the drum device 3 is performed.

In step S502, when the drum motor 33 is stopped, the reproducing magnetic head is inserted into the insertion port 9a.
The stop position may be controlled so as not to face the direction. Thus, when static electricity is generated during the unloading operation in step S503, discharge to the MR head can be prevented.

In step S504, if a command signal for ejecting the cassette case 7 is received from the computer device 20, the process proceeds to step S505. In step S505, the motor for moving the cassette mechanism 8 is driven to move the cassette mechanism 8 holding the cassette case 7 toward the insertion opening 9a of the cassette mechanism 8. In step S506, with the movement of the cassette mechanism 8, the light detection signal from the cassette sensor 15 is detected again to detect that the cassette case 7 has been ejected. In step S507, the position of the reproducing magnetic head is controlled by driving the drum motor 33. Thereby, the reproducing magnetic head is
The cassette case 7 is stopped at a position not facing the insertion opening 9a. At this time, the cassette case 7 is
a.

The detection when the cassette case 7 is discharged is as follows.
The computer device 20 is operated by an operation input or the like from the user.
Therefore, when a command signal for ejecting the cassette case 7 is transmitted, the system controller 11 may receive the command signal to perform the operation. In this case, the movement operation of the cassette mechanism 8 in step S505 is started simultaneously with the position control of the reproducing magnetic head.

Next, an example of position control of the reproducing magnetic head will be described. First, FIG. 6 conceptually shows an example of position control in the case where the magnetic heads are arranged at a 90 ° offset in the rotating drum.

In FIG. 6, a pair of recording magnetic heads W
1 and W2 are inductive magnetic heads,
The pair of reproducing magnetic heads R1 and R2 are MR heads. On the rotating drum 34a shown in FIG. 6, a reproducing magnetic head R1, a recording magnetic head W1, a reproducing magnetic head R2, and a recording magnetic head W2 are respectively 90 ° apart from the rotation axis of the rotating drum 34a. They are arranged in a shifted state. In such an arrangement, reading or writing to the magnetic tape 2 is performed twice, that is, for two tracks, while the rotating drum 34a makes one rotation.

In the rotating drum 34a, when the cassette case 7 is inserted and ejected, for example, as shown in FIG. 6, the recording magnetic head W1 or W2 is stopped so as to face the insertion opening 9a of the cassette case 7. Is done. Alternatively, the outer peripheral surface of the rotary drum 34a close to the recording magnetic head W1 or W2 may be directed toward the insertion port 9a. By such position control, the magnetic tape 2
Always contacts the recording magnetic head W1 or W2 or the outer peripheral surface of the rotating drum 34a electrically connected to the ground, and the static electricity charged on the magnetic tape 2 is discharged through these.

FIG. 7 shows that a combination of a plurality of reproducing or recording magnetic heads is 180
° Regarding an example of position control in the case of being shifted
Shown conceptually.

On the rotating drum 34b shown in FIG. 7, the recording magnetic heads W3 and W4 and the reproducing magnetic heads R3 and R4 are arranged 180 ° apart from each other about the rotation axis. In such an arrangement, the rotating drum 34b is
During the rotation, it is possible to simultaneously read or write signals on a plurality of tracks on the magnetic tape 2 by the respective combinations of the recording magnetic heads W3 and W4 or the reproducing magnetic heads R3 and R4.

In the rotating drum 34b, when the cassette case 7 is inserted and ejected, for example, as shown in FIG. 7, the recording magnetic heads W3 and W4 and the reproducing magnetic heads R3 and R4 are both cassettes. The case 7 is stopped so as not to face the insertion opening 9a. By such position control, the magnetic tape 2 always comes into contact with the outer peripheral surface of the rotary drum 34b first, and the static electricity charged on the magnetic tape 2 is discharged through these, and the static electricity of the reproducing magnetic heads R3 and R4 is discharged. Destruction is prevented.

[0050]

As described above, in the magnetic recording / reproducing apparatus of the present invention, the rotating drum is rotated at the time of insertion and ejection of the cassette case under the control of the rotation control means, so that the magnetic head for reproduction is moved to the cassette case. The cassette tape is stopped so that it does not face the direction of the insertion slot, so that when the inserted cassette case is charged with static electricity, it is possible to prevent the magnetic tape and the reproducing magnetic head from first contacting each other to cause discharge. . Also, after discharging the cassette case, unexpected static electricity charged substance is inserted inside,
Even in the case of contact with the rotating drum, it is possible to prevent discharge through the reproducing magnetic head. This makes it possible to prevent electrostatic damage of the magnetoresistive element.

Further, in the rotary drum drive control method of the present invention, when the cassette case is inserted and ejected, the rotary drum is rotated so that the reproducing magnetic head is stopped so as not to face the insertion opening of the cassette case. When the inserted cassette case is charged with static electricity, it is possible to prevent the magnetic tape and the reproducing magnetic head from first contacting each other to cause discharge. Further, even if an unexpectedly charged substance is inserted inside the cassette case and comes into contact with the rotating drum after the cassette case is discharged, it is possible to prevent the discharge through the reproducing magnetic head. This makes it possible to prevent electrostatic damage of the magnetoresistive element.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a control system for driving each unit in a magnetic recording / reproducing apparatus of the present invention.

FIG. 2 is a diagram showing a schematic configuration example of PG and FG functioning as position detecting means of a reproducing magnetic head.

FIG. 3 is a diagram showing an example of a schematic configuration around a magnetic tape traveling system in the magnetic recording / reproducing apparatus of the present invention.

FIG. 4 shows a flowchart of processing by a system controller from insertion of a cassette case to recording or reproduction of a magnetic tape.

FIG. 5 shows a flowchart of processing by the system controller from the stop of the recording or reproduction operation of the magnetic tape to the ejection of the cassette case.

FIG. 6 is a diagram conceptually illustrating an example of position control in a case where magnetic heads are arranged at a 90 ° offset in a rotating drum.

FIG. 7 is a diagram conceptually illustrating an example of position control in a case where a combination of a plurality of reproducing or recording magnetic heads is arranged 180 ° apart on a rotating drum.

FIG. 8 is a diagram showing a schematic configuration example of a conventional magnetic recording / reproducing device using a helical scan method.

9A and 9B are diagrams showing measurement results of an ESD breakdown voltage in an MR head, wherein FIG. 9A shows a measurement result for an AMR head, and FIG. 9B shows a measurement result for a GMR head.

FIG. 10 is a diagram conceptually showing a flow of charges when a magnetic tape and an MR head come into contact with each other.

FIG. 11 is a diagram illustrating a state where a user's hand is inserted into the magnetic recording / reproducing apparatus.

[Explanation of symbols]

1 magnetic recording / reproducing device, 2 magnetic tape, 3 drum device, 4 capstan, 5 pinch roller,
6a to 6e: tape guide, 7: cassette case,
7a ... supply reel, 7b ... take-up reel, 8 ...
Cassette mechanism, 9 front panel, 9a insertion slot, 11 system controller, 12 FG amplifier, 13 PG amplifier, 14 motor driver, 1
5 ... cassette sensor, 20 ... computer device, 3
1 ... FG, 32 ... PG, 33 ... Drum motor

Continuing on the front page (72) Inventor Katsuhiro Kasuga 30 No. Kagano Border, Takae Niida, Nakata-cho, Tome-gun, Miyagi Prefecture Inside Sony Miyagi Co., Ltd. (72) Inventor Shinichi Fukuda 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Stock In company

Claims (5)

[Claims] 1. A magnetic recording / reproducing apparatus for recording / reproducing a signal on / from a magnetic tape, comprising: a rotating drum having a reproducing magnetic head using a magnetoresistive element; and a drum for driving the rotating drum to rotate. Rotating drive means, when inserting and ejecting a cassette case in which the magnetic tape is wound and stored, by rotating the rotary drum so that the reproducing magnetic head is not directed toward the insertion opening of the cassette case; And a rotation control means for controlling the drum rotation driving means so as to stop the rotation. 2. The apparatus according to claim 1, further comprising: a position detecting unit for detecting a position of the reproducing magnetic head, wherein the rotation control unit controls the drum rotation driving unit based on a detection signal from the position detecting unit. The magnetic recording / reproducing apparatus according to claim 1. 3. A cassette detecting means for detecting insertion and ejection of the cassette case, wherein the rotation control means determines when to insert and eject the cassette case based on a detection signal from the cassette detecting means. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein: 4. The method according to claim 1, wherein the rotation control unit stops the magnetic tape at a position where the magnetic head for reproduction does not face in the direction of the insertion port when a loading operation and an unloading operation of the magnetic tape with respect to the rotating drum are started. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the magnetic recording / reproducing apparatus controls a drum rotation driving unit. 5. A method for controlling driving of a rotary drum in a magnetic recording and reproducing apparatus for recording and reproducing signals on and from a magnetic tape, comprising detecting when a cassette case in which the magnetic tape is wound and stored is inserted and ejected. Rotating a rotary drum including a reproducing magnetic head using a magnetoresistive element, and stopping the rotating drum at a position where the reproducing magnetic head does not face the insertion opening of the cassette case. Rotary drum drive control method.