JPH0823977B2 - Magnetic disk device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, and more particularly to a magnetic disk device for writing and reading information by bringing a magnetic head into contact with or facing a rotating magnetic disk. Is.

[Prior Art] A magnetic disk device is widely used in which a magnetic head contacts or faces a rotating magnetic disk to perform magnetic recording and reproduction.

A so-called floppy disk device has been widely adopted as such a magnetic disk device, but recently, a still video camera and the like have been put into practical use.

In such a magnetic disk device, the reliability of the recording and reproducing operations depends on whether or not the magnetic head having a gap of about 1 μm is constantly and accurately in contact with or facing the magnetic disk (the "spacing loss" is small). It depends on you.

However, there may be a case where the magnetic head cannot accurately contact the magnetic disk due to variations in the accuracy of parts of the device.

Therefore, there is known an apparatus provided with an adjusting mechanism capable of adjusting the magnetic head so as to accurately contact or face the magnetic disk.

Such an adjusting mechanism has no problem in the case of considering one specific magnetic disk device, but has a problem in consideration of compatibility between several different magnetic disk devices.

That is, the magnetic head is accurately moved in the vertical direction,
The center of the gap of the magnetic head moving in the diametrical direction of the magnetic disk and the center of the rotating magnetic disk with respect to the center axis of rotation of the rotating magnetic disk are aligned with each other in addition to the adjustment so as to accurately contact or face the magnetic disk. If you do not do this, compatibility cannot be obtained.

[Purpose] The present invention has been made in order to eliminate the above-mentioned conventional drawbacks. The position of the magnetic head with respect to the magnetic disk is determined by the diameter direction of the magnetic disk, the rotational axis direction of the magnetic disk, and the rotational tangential direction of the magnetic disk. It is an object of the present invention to provide a magnetic disk device that can be easily and accurately fine-tuned, improved in reliability for magnetic recording and reproduction, and provided with excellent compatibility.

[Examples] Hereinafter, details of the present invention will be described based on Examples shown in the drawings.

FIG. 1 and the following figures illustrate an embodiment of the present invention, and the illustrated embodiment is illustrated as a type in which two magnetic disk cassettes are mounted, but of course one may be provided.

This type of magnetic disk unit becomes a large-capacity storage device when used in combination with a computer, and when an important program is stored on one magnetic disk, it is immediately copied and stored on the other magnetic disk. This is extremely advantageous because it can.

The magnetic disk device according to the present embodiment is assembled based on the chassis 1. When roughly classified, two sets of head moving mechanisms 2 and 2 mounted on the chassis 1 and a motor provided on the lower surface of the chassis 1 are used. 3 and a cassette mounting mechanism 4, 4 provided on the chassis 1 so as to cover the head moving mechanism 2, 2.

 Hereinafter, details of each unit will be described in order.

As shown in FIGS. 7 and 8, the head moving mechanism 2 includes a guide 5 fixed on the chassis 1 and a slider mounted slidably in a state of covering the guide 5 from the upper side to the left and right sides. Have six.

Two guide bars 7 each having a circular cross section are fixed at opposite positions on both side surfaces of the guide 5 and an inner side surface of the U-shaped slider 6, and a total of four guide bars 7 are provided.
A plurality of steel balls 8 are arranged in contact with each other.

Therefore, the guide bar 7 and the steel balls 8 are in point contact with each other at four places, and the slider 6 can be moved extremely smoothly without being affected by the frictional force.

Further, if there is looseness between the guide bar 7 and the steel ball 8, the slider 6 cannot move linearly with high precision, so the guide bar 7 is screwed through the plate 9 by the screw 10.
Is pressed against the steel ball 8 to remove the play.

Although not shown, the slider 6 is pressed by a spring in a direction approaching the pulse motor 11 described later.

On the other hand, one end of a head arm 12 is fixed to the slider 6, the head arm 12 bends and extends along one side of the slider 6, and is guided along the upper surface of the chassis 1.
A magnetic head 14 is fixed to the upper surface of the tip via a head base 13.

The head base 13 is fixed via the screw 15, but the hole into which the screw 15 fits is a long hole 13a along the longitudinal direction of the head base 13, and between the screw 15 and the head base 13. The disc spring 16 is elastically mounted to remove the play in the vertical direction of the head base 13.

A torsion coil spring 17 is attached to the upper surface of the head arm 12 near the head base 13, one end of which is in contact with a pin 18 on the head arm 12 and the other end is the head base.
The head base 13 is pressed against the side surface of the head arm 13 toward the tip of the head arm 12.

A bent portion 12a is formed at the tip of the head arm 12, and a screw 19 is screwed therein. The tip of the screw 19 is in contact with the side surface of the head base 13 opposite to the torsion coil spring 17.

Therefore, by rotating the screw 19 back and forth, the position of the magnetic head 14 is adjusted in cooperation with the force of the torsion coil spring 17, and the deviation 1 between the straight line passing through the motor shaft and the center of the magnetic head, which will be described later, is set to 0. can do.

On the other hand, one end of the adjusting plate 20 is fixed to the upper surface of the slider 6 above the head arm 12. The other end of the adjusting plate 20 is bent along the bent shape of the head arm 12, and the tip end thereof extends partway into the head arm 12.

A screw 21 is screwed into the tip of the adjusting plate 20, and the lower end of the screw 21 is in contact with the upper surface of the head arm 12.
Therefore, by rotating the screw 21, the screw 21 can be moved up and down, and the vertical position of the magnetic head 14 can be adjusted via the head arm 12.

As shown in FIG. 8, side plates are provided on both ends of the slider 6.
22,23 are fixed.

On the other hand, at a position away from the slider 6, a support plate 24 is fixed on the chassis 1 in parallel with the side plates 22 and 23, and the pulse motor 11 is fixed to the support plate 24. A pinion gear 25 is fixed to the output shaft 24a of the pulse motor 24.

In addition, as shown in FIG.
A screw cylinder 26 is fixed alongside 11, and a screw shaft 27 is screwed into the screw cylinder 26.

Two gears 29, 3 are attached to the outer end of the screw shaft 27 via a boss 28.
0 is installed. These gears 29 and 30 mesh with the pinion gear 25, one gear 29 is fixed to the boss 28, and the other gear 30 is rotatable.

An opening 30a is formed in the rotatable gear 30, and a pin 31 protruding from the side surface of the gear 29 is fitted in the opening 30a. A spring 33 is stretched between the pin 31 and a pin 32 protruding from the outer surface of the gear 30, and gives a force to rotate the gear 30 in the clockwise direction in FIG.

Therefore, the teeth of the gears 29 and 30 tend to shift from each other, but when the gears 29 and 30 mesh with the pinion gear 25,
The teeth are forced into alignment and the forces of shifting act to prevent backlash.

A pin 34 is provided on the end surface of the boss 28 on the support plate 24 side.

The inner end of the screw shaft 27 is in contact with the outer surface of the adjusting screw 35 screwed onto the outer surface of the side plate 22.

Therefore, when the pulse motor 11 is rotated, the gears 29, 30
The screw shaft 27 moves back and forth through the slider 6, head arm 12
The magnetic head 14 is moved in the diametrical direction of the magnetic disk through the head to move the head.

On the other hand, on the outer surface of the support plate 24, a shaft 36 is provided so as to project in the vicinity of the screw shaft 27, and a shutter plate 37 is rotatably supported at its one end via a boss 37a on the shaft 36. There is.

On the upper side of the end of the shutter plate 37 on the boss 37a side, the spring piece 3
8 is provided, the tip of which is the outer surface of the support plate 24,
Further, it is in contact with the lower side of a pin 39 protruding above the screw shaft 27, and gives the shutter plate 37 a tendency to rotate in the clockwise direction in FIG.

However, the clockwise rotation limit of the shutter plate 37 is restricted by the lower portion 37b at the tip of the shutter plate 37 coming into contact with the pin 40 protruding from the support plate 24.

Further, openings 41 and 42 are formed at positions where the shutter plate 37 and the support plate 24 can coincide with each other. Support plate 24 opening 4
A photo sensor 43 including a light emitting element and a light receiving element is provided on the back side of 2.

The shutter plate 37 constitutes pulse generation means (TR "OO" detection mechanism) for detecting that the magnetic head has reached the outermost track position of the magnetic disk and generating a pulse.

On the other hand, the chassis 1 has head moving mechanisms 2, 2
Ejector lever 44 is provided corresponding to.

The eject lever 44 is formed in an elongated plate shape,
Long holes 44a are formed in the front and rear along the axial direction.

Pins 45 and 46 projecting from the chassis 1 are slidably fitted in the elongated holes 44a.

An eject button 47 is fixed on the front side of the eject lever 44.

A spring 48 is provided between the pin 46 near the eject button 47 and the bent portion 44b at the tip of the eject lever 44.
Is provided to give the eject lever 44 a habit of moving to the right in FIG. 2, and pins 45 and 46 are normally in contact with the left ends of the long holes 44a and 44a.

The eject lever 44 is provided with an upright cam 49 located between the pins 45 and 46.

A slope 49a is formed on the cam 49 on the eject button 47 side.

This eject lever 44 is a cassette mounting mechanism described later.
The cassette ejection operation is performed in conjunction with 4, 4.

In addition, each head moving mechanism 2, 2 is attached to the chassis 1.
Corresponding to, the motor shaft 50 is provided in a protruding state.

The motor shaft 50 has a cup-shaped member 51 with an open upper end.
Have integrally.

The height of the cup-shaped member 51 is lower than the height of the motor shaft 50 and is made of a non-magnetic material.

A ring-shaped magnet 52 is fixed to the bottom surface of the cup-shaped member 51.

The reason for providing such a magnet 52 is as follows.

That is, as shown in FIG. 6, the magnetic disk 53 has a boss (made of synthetic resin) 54 fitted to the motor shaft 50 at the center thereof.
The magnetic disk 53 is fixed in a state of being sandwiched between the boss 54 and the washer 55 made of a magnetic material.

Therefore, when the magnetic disk cassette is mounted and the motor shaft 50 is fitted into the boss 54 as described later, the magnetic flux of the magnet 52 is guided through the vicinity of the cup-shaped member 51 and is made of a magnetic material. The washer 55 can be attracted by magnetic force.

Therefore, the rotational force of the motor can be reliably transmitted to the magnetic disk side without slipping between the motor shaft 50 and the boss 54.

The motor shaft 50 is rotatably attached to the chassis 1 via a disk-shaped bearing 56.

A disc 57 is fixed to the lower end of the motor shaft 50 on the lower side of the chassis 1.

The disk 57 is fixed to the rotor 58. The rotor 58 has a ring-shaped magnet 59 and a signal generating gear 60 for controlling rotation.

One end of a belt 61 is wound around the rotor 58, and the other end is wound around the rotor 62 of the other motor shaft 50.

The belt 61 is in contact with the tension roller 63 so as to prevent the unstable rotation due to the bending.

On the other hand, a printed circuit board 64 is fixed to the lower surface of the chassis 1 so as to surround the motor shaft 50.
A coil 65 formed in a ring shape is fixed to 64,
It faces the magnet 59 of the rotor 58.

Therefore, when the coil 65 is energized, a magnetomotive force is generated to rotate the rotor 58 via the magnet 59.

When the rotor 58 rotates, the rotor 62 rotates via the belt 61 and the other motor shaft can also rotate.

The rotor 58 and the coil 65 described above constitute the motor 3.

On the other hand, the cassette mounting mechanism 4 is configured as shown in FIGS.

That is, the cassette mounting mechanism 4 has a rotating frame 66, and the bending portions 66a formed at both ends on the inner side of the rotating frame 66 are provided in the chassis 1 in the vicinity of the head moving mechanism 2. Department
1a and 1a are rotatably supported respectively.

A cassette guide 67 formed as a flat frame is slidably attached to the rotating frame 66.

A magnetic disk cassette 68 is slidably fitted in the cassette guide 67.

A large opening is provided below the cassette guide 67 so that the magnetic head, the motor shaft and the like can be freely accessed.

On the other hand, a lever 69 having an L-shaped cross section is slidably in contact with a side edge of the cassette guide 67.

An elongated opening is provided at a corner of the lever 69 over a predetermined length.
69a is formed, and a protrusion 67a cut and raised from the cassette guide 67 is fitted into the opening 69a.

2 along the longitudinal direction of the lever 69 on the vertical part of the lever 69.
Individual long holes 69b are formed, and pins 70 protruding from the cassette guide 67 are slidably fitted in the long holes 69b.

Further, a pin 71 that engages with a projecting piece 1b projecting on the chassis 1 side is provided at the vertical portion of the lever 69 at a position near the insertion port side of the cassette.

A spring 72 is stretched between a bent portion 69c protruding from the end of the lever 69 opposite to the pin 71 and a protrusion 67a of the cassette guide 67. Is given the force to be pulled toward the insertion opening side.

In addition, a spring 73 is provided between the protruding piece 67a and the chassis 1.
The frame is stretched, and the rotating frame including the cassette guide 67
The entire 66 is pulled toward the chassis 1.

A bent portion 69d is formed at the tip of the lever 69, and the bent portion 69d engages with the tip of the magnetic disk cassette 68 as described later.

By the way, one end of a leaf spring 74 is fixed to the upper surface of the cassette guide 67, and the tip of this leaf spring 74 extends to between two elongated holes 67b, 67b formed in the central portion of the cassette guide 67. There is.

These elongated holes 67b are formed in the same direction as the attaching / detaching direction of the magnetic disk cassette 68.

A roller 75 fitted in the long hole 67b is provided at the tip of the leaf spring 74.

As shown in FIG. 5, the roller 75 is in contact with the upper surface of the boss 54 of the magnetic disk located below the long hole 67b, and the leaf spring 74
The cup-shaped member that integrates the boss 54 with the motor shaft 50 by the force of
It is pressed against 51.

Therefore, in cooperation with the attraction force of the magnet 52, slip is prevented from occurring when the magnetic disk rotates.

An opening 76 is formed near the long hole 67b.

A PG pin (index pin) 77 embedded in the boss 54 faces the opening 76, and a sensor 78 faces from the upper side.

The sensor 78 is connected to a printed circuit board 79 fixed on the cassette guide 67, and is a magnetoresistive effect element (MR element).
Etc.

The magnetic flux of the magnet 52 is applied to the PG pin 77 by the cassette member 51.
And a weak magnetic field is induced.

This magnetic field is extremely weak, but the sensor 78 of the MR element detects this, the internal resistance value changes, and a pulse is created by using the resistance change amount by using a comparator or the like.
One pulse is generated by rotation and used as an index signal.

Since the MR element is sensitive to an extremely weak magnetic field, if the device of this embodiment is attached to a personal computer or the like, malfunction may occur due to changes in magnetic flux generated around the CRT, around the transformer, and around the motor.

Therefore, in this embodiment, the cassette guide 67 is made of an iron-based material having a large magnetic shield effect to prevent malfunction.

Further, considering the magnetic shield effect, it is preferable that the size of the opening 76 is small, but in this embodiment, since the index detection mechanism using the MR element is adopted, the diameter is 10 as shown in FIG. The size of the boss 54 was about 15 mm, and could fit within the size of the boss 54.

Further, since the MR element can detect a magnetic field change regardless of the magnetic flux change speed, it is optimal as a compact and high speed index detection device.

It should be noted that one end of a pad lever 80 is rotatably attached to the back side of the cassette guide 67, and a pad 81 provided on the lower surface of the free end thereof passes through an opening 82 of the cassette guide 67 and serves as a magnetic head. Magnetic disk at the corresponding position
By pressing 53 from above, the magnetic disk and the magnetic head can be reliably brought into contact with each other.

The pad 81 is fixed to the screw 83 attached to the tip of the pad lever 80.
The contact pressure of 81 with respect to the magnetic disk 53 can be adjusted.

On the other hand, the magnetic disk cassette 68 is shown in FIG.
It is configured as shown in (C).

The magnetic disk cassette 68 is a flat case formed by combining two upper and lower cassette halves 84 made of hard synthetic resin or the like, in which the magnetic disk 53 is rotatably accommodated via a boss 54. There is.

Further, each of the cassette halves 84 is formed with an opening 68a into which a magnetic head or a pad is fitted at a position facing each other.

Further, the shutter 85 for preventing dust and the like from entering through the opening 68a has a recess 8 including the opening 68a.
6 is slidably fitted inside.

The shutter 85 can freely move to a position where it comes into contact with one end 86a and the other end 86b of the recess 86, and opens and closes the opening 68a.

The shutter 85 is automatically opened / closed by using the operation of attaching / detaching the cassette in / from the cassette guide 67, and its opening / closing mechanism is shown in FIGS. 16 (A) and 16 (B).

That is, at the position opposite to the side edge of the cassette guide 67 where the lever 69 is provided, one end of the opening / closing lever 87 is rotatably supported by the projecting piece 89 on the cassette guide 67 side via the pin 88. .

A torsion coil spring 90 is wound around the pin 88 to give the opening / closing lever 87 a turning tendency in the clockwise direction in FIG.

On the free end side of the opening / closing lever 87, first projections and second projections 87a and 87b serving as stoppers are provided to project toward the cassette guide 67 side.

The first projection 87a has a slanted surface 87c formed at the tip thereof so that the insertion opening side of the cassette is lowered, and the rear end side thereof is provided with the upright wall 8c.
It is 7d.

On the other hand, a protrusion 91 is provided on the inside of the cassette guide 67, and the opening 9 into which the protrusion 87a of the opening / closing lever 87 is fitted at a position closer to the insertion opening side of the cassette than the protrusion 91.
2 is formed.

Next, the cassette shutter 85 configured as described above
The operation of the opening / closing mechanism will be described.

FIGS. 17A to 17D are for explaining the operation of opening the shutter. As shown in FIG. 17A, when the cassette 68 is inserted into the cassette guide 67 with the shutter 85 closed. , The tip of the first protrusion 87a of the opening / closing lever 87 is the shutter 8
The tip of the first protrusion 87a rides on the side surface of the shutter 85 as shown in FIG.

When the cassette 68 is further pushed in this state, the edge of the shutter 85 contacts the protrusion 91, and at the same time the first protrusion 87a of the opening / closing lever 87 is formed on the side surface of the shutter 85 as shown in FIG. The portion 85a is fitted into the shutter 85.

When the cassette 68 is further pushed, only the shutter 85 remains because the shutter 85 is blocked at that position by the projection 91, and the shutter 85 is opened as shown in FIG.

On the other hand, the operation of closing the shutter 85 is shown in FIGS.
It is performed as shown in.

FIG. 18 (A) shows a state in which the cassette is mounted. When the cassette starts to be ejected from this state by the operation described later, the shutter 85 is released as shown in FIG. 18 (B).
Since the edge of the opening 85a of the shutter hits the upright wall 87d of the first protrusion 87a of the opening / closing lever 87, the shutter 85 stays at that position and is moved in the direction in which only the cassette 68 is discharged.

Then, the cassette is temporarily stopped in the state shown in FIG. 18 (B).

At this time, the tip of the cassette 68 protrudes from the cassette guide 67 by a predetermined distance. Therefore, if the operator pulls it out with his finger, the opening / closing lever 87 cannot withstand a strong force, and as shown in FIG. The cassette 68 can be taken out with the shutter closed while being forcibly rotated counterclockwise in FIG.

Now, the overall operation of the apparatus of the present embodiment configured as described above will be described.

When the power is turned on, a current flows through the coil 65, the rotor 58 rotates, and the motor shaft 50 rotates.

In this state, no cassette guide 67
68 can be installed. Before the cassette 68 is mounted, the eject lever 44 is pushed against the tensile force of the spring 48 to move it forward so that the slope 49a of the protrusion 49 is pushed under the pin 70 of the lever 69 on the cassette guide 67 side. Is located above the protrusion 49.

Then, the cassette guide 67 is lifted together with the rotating frame 66 in an inclined state.

At this time, as shown in FIG. 4 (A), the pin 71 is on the protrusion 1b on the chassis 1 side, the lever 69 is pulled to the front side by the pulling force of the spring 72, and the tension of the spring 73 is pulled. The pin 71 is pressed against the protrusion 1b by the force.

Therefore, even if the eject lever 44 is released, the cassette guide
67 never descends.

That is, the front side of the cassette guide 67 is lifted and the cassette insertion port is set in the standby state.

If the cassette 68 is inserted into the cassette guide 67 in this state, the cassette is inserted while the shutter 85 is automatically opened as described above.

On the other hand, when the cassette 68 is inserted, the tip of the cassette contacts the bent portion 69d at the tip of the lever 69, and the lever 69 is pushed together with the cassette 68.

As a result, the spring 72 is moved until the extension pin 70 comes into contact with the right end of the elongated hole 69b, and the pin 71 comes off the protrusion 1b and comes into contact with the inner side edge of the protrusion 1b as shown in FIG. 3 (A). It becomes a state.

That is, the cassette guide 67 moves down together with the cassette 68, and the boss 54 is fitted to the motor shaft 50.

At the same time, the tip of the pad lever 80 descends and the magnetic head 14
The pad 81 is pressed against the magnetic disk 53.

In this state, the rotation of the magnetic head starts and the sensor 78 and PG
Index detection is performed by the pin 77, and the head moving mechanism 2 is operated by the rotation of the pulse motor 11 to move the head.

Output phase when + phase pulse is applied to pulse motor 11
24a is rotated clockwise in FIG. 9, and is rotated counterclockwise when a -phase pulse is applied.

Here, when the gears 29, 30 are rotated in the clockwise direction in FIG. 9 via the pinion gear 25, the screw shaft 27 is also rotated in the same direction, and the gears 29, 30 move toward the shutter plate 37.

When the gears 29 and 30 are rotated counterclockwise, the gears 29 and 30 are separated from the shutter plate 37.

Now, when the gears 29, 30 rotate clockwise in FIG. 9 and move toward the shutter plate 37, the pin 34 protruding from the boss 28 moves to the 11th position.
As shown in the figure, the shutter plate 37 begins to contact the lower edge.

Then, the shutter plate 37 is rotated counterclockwise in FIG. 11 about the shaft 36.

The opening 41 of the shutter plate 37 is normally the opening 42 of the support plate 24.
Since the light from the light emitting element of the sensor 43 hits the shutter plate 37 and is reflected by the light receiving element, the sensor 43 is in the ON state.

However, the gears 29, 30 move from the state shown in FIG. 10A to the state shown in FIG.
34 contacts the lower edge of the shutter plate 37, and
When rotated counterclockwise in the figure, as shown in FIG. 12, the openings 41 and 42 are aligned and the light from the light emitting element of the sensor 43 passes through and does not return to the light receiving element side. Therefore, the sensor 43 is turned off.

At this time, the magnetic head 14 has reached the outermost track.

Distance L from the center of the magnetic disk to the outermost track
Is 20 mm, the magnetic head is located at the outermost track of the track 20 mm away from the center.

However, even if the opening 41 of the shutter plate 37 and the opening 42 of the support plate 24 coincide with each other due to variations in component precision, the magnetic head is not always positioned in the state of L = 20 mm.

Therefore, turn the screw 35 with which the tip of the screw shaft 27 is in contact to turn L =
Adjust to be 20mm.

The adjustment method is to first set the openings 41 and 42 so that they coincide with each other, as shown in FIG. 12, and turn off the sensor 43.
In FIG. 8, the screw 35 may be rotated by a microscope or the like so that the distance from the center of the motor shaft 50 to the magnetic head 14 is 20 mm.

Then, when L = 20 mm, the screw 35 is locked with an adhesive or the like.

According to an experiment conducted by the present inventor, by adjusting the pitch of the screws 35 to 0.3 mm, it was possible to sufficiently adjust about ± 2 μm for L = 20 mm.

Since the pitch of the screw of the screw shaft 27 is set to 0.5 mm, the pin 34 is attached to the shutter plate as shown in FIG. 10 (B).
When the screw shaft 27 makes one rotation counterclockwise in FIG. 9 from the state of being in contact with the lower edge of 37, the pin 34 separates from the shutter plate 37 as shown in FIG. 10 (C).

That is, between the state of FIG. 10A and the state of FIG. 10B, the pin 34 hits the shutter plate 37 and the sensor 43 is turned off only when the pin 34 hits the shutter plate 37. Yes, the sensor 43 is not turned off otherwise.

By the way, while rotating the shutter plate 37 from the state shown in FIG. 11 to the state shown in FIG. 12, the screw 27 rotates β = 9 ° and the sensor 43 is turned off.

When the screw shaft 27 rotates 9 °, the pin 34 becomes an arc shape of about 0.4 mm.
Moving.

 The width of the openings 41, 42 is set to 1.2 mm.

Therefore, in the present embodiment, the distance from the center of the shaft 36 to the position where the pin 34 is in contact is determined from the center of the pin 36 to the openings 41, 42.
The distance to the pin is set to 1/3 of the
The rotation of 37 is utilized to expand to 1.2 mm, and the openings 41 and 42 through which the light of the sensor 43 passes are enlarged to improve efficiency.

Generally, when using an optical sensor, it is preferable to guide the amount of light from the light emitting element to the light receiving element as efficiently as possible, and the larger the opening through which the light from the sensor 43 passes, the better.

Also, in order to prevent the light quantity from the light emitting element from returning to the light receiving element in order to turn off the sensor 43, it is preferable that the opening be large.

For such a purpose, the slight rotation angle of the screw shaft 27 of 9 ° is enlarged by utilizing the lever ratio of the shutter plate 37 to improve the efficiency of the sensor.

On the other hand, FIG. 13 shows a further 9 ° screw shaft 27 from the state of FIG.
Shows a rotated state.

In this state, α = 18 °, the sensor 43 is turned on, it can be detected that the magnetic head 14 has jumped out beyond L = 20 mm, and a signal for reversing the pulse motor 11 to return it to the normal position can be obtained. .

In this way, magnetic recording / reproduction can be performed while accurately determining the outermost track position.

On the other hand, if you want to remove the cassette after magnetic recording / reproduction is complete, use the eject button 47 to
When is pressed, the cassette guide 67 is lifted via the pin 70 by the protrusion 49 of the eject lever as described above. This state is the state shown in FIG. 4 (A) described above.

At this time, the lever 69 returns due to the force of the spring 72, so that the cassette 68 is pulled out by the bent portion 69d of the lever 69.

This pull-out distance is small, but the cassette 68
Projects from the cassette guide 67, the cassette can be easily pulled out by pinching the projected part with a finger.

Then, when this is pulled out, the shutter 85 is automatically closed as described above.

In addition, in the above-mentioned example, the head moving mechanism 2 is illustrated as being separately provided, but the present invention is not limited to this, and as shown in FIG. You can use only individual pieces.

In order to adopt such a modified example, the head arm is 12,1
The two heads 2a may be integrally formed, and the magnetic heads 14 may be attached to each of them.

[Effect] As is apparent from the above description, according to the present invention, the head arm carrying the magnetic head is fixed to the slider,
In a magnetic disk drive equipped with a head moving mechanism that moves the magnetic head in the radial direction of rotation of the magnetic disk by moving the slider, the position of the magnetic head relative to the magnetic disk can be adjusted in three different directions. It has first, second and third adjusting means, and these first
The first, second, and third adjusting means independently perform adjustment with respect to the other adjusting means, and the first adjusting means has the head moving mechanism with the slider positioned at a predetermined position. The feed screw which it has can be finely adjusted in the screw axis direction, the second adjusting means can finely adjust the head arm in the rotation axis direction of the magnetic disk on the slider, and the third adjusting means is the magnetic head. Since the head is moved parallel to the recording surface of the magnetic disk on the head arm and fine adjustment is possible in the rotational tangential direction of the magnetic disk, the position of the magnetic head with respect to the magnetic disk can be easily and accurately adjusted. It can be anything.

That is, as a method for finely adjusting the position of the magnetic head with respect to the magnetic disk, in the diametrical direction of the magnetic disk, the feed screw of the head moving mechanism is finely adjusted in the screw axis direction by the first adjusting means, so that 2), the head arm is finely adjusted on the slider in the rotational axis direction of the magnetic disk by the second adjusting means. Regarding the rotational tangential direction, the magnetic head itself is moved on the head arm by the third adjusting means. By making parallel movement to the recording surface and finely adjusting in the rotational tangential direction, fine adjustment of the position in each direction can be independently and accurately performed without interfering with each other.

Further, since the fine adjustment of the position of the magnetic head can be accurately performed in this manner, the compatibility of the magnetic head can be improved and the reliability in recording and reproducing of the magnetic head can be improved.

[Brief description of drawings]

FIG. 1 illustrates an embodiment of the present invention. FIG. 1 is an overall perspective view, FIG. 2 is an exploded perspective view, and FIGS. 3A and 3B are cassette guides and eject levers in a cassette mounted state. 4A is a partial vertical side view, FIGS. 4A and 4B are partial vertical side views of the cassette guide and the eject lever when the cassette is ejected, and FIGS. 5A and 5B are magnetic disk pressing mechanisms. FIG. 6 is a plan view and a vertical side view of the magnetic disk drive unit, FIG. 6 is a vertical side view of a main part of the magnetic disk drive mechanism, FIG. 7 is a vertical side view of the head moving mechanism, and FIG. 8 is a plan view of the head moving mechanism. FIG. 9 is an exploded perspective view of the track outermost circumference detection mechanism, 10 (A) to (C) are plan views for explaining the operation of the track outermost circumference detection mechanism, and FIGS. 11 to 13 are operations of the shutter plate. FIG. 14 is a front view for explaining a modification of the head moving mechanism. Plan view bright, FIG. 15 (A) ~
(C) is a plan view, front view and vertical side view of the magnetic disk cassette, FIGS. 16 (A) and (B) are exploded perspective views and plan views for explaining the shutter opening / closing mechanism, and FIGS. 17 (A) to (A). D)
Is a plan view for explaining the shutter opening operation, FIG.
FIG. 6C is a plan view illustrating the operation of closing the shutter. 1 …… Chassis, 2 …… Head moving mechanism 3 …… Motor, 4 …… Cassette mounting mechanism 6 …… Slider, 11 …… Pulse motor 14 …… Magnetic head, 19,21,35 …… Screw 27 …… Screw Axis, 43 …… Sensor 44 …… Eject lever 50 …… Motor shaft, 58 …… Rotor 65 …… Coil, 66 …… Rotating frame 67 …… Cassette guide 68 …… Magnetic disk cassette 69 …… Lever, 70, 71 …… pin 74 …… leaf spring, 78 …… sensor

Claims (1)

[Claims] 1. A magnetic disk device comprising a head moving mechanism, wherein a head arm having a magnetic head mounted thereon is fixed to a slider, and the slider is moved to move the magnetic head in the radial direction of rotation of the magnetic disk. The position of the magnetic head with respect to the magnetic disk can be adjusted in three different directions.
The first, second, and third adjusting means independently adjust the other adjusting means, and the first adjusting means positions the slider at a predetermined position. The feed screw of the head moving mechanism can be finely adjusted in the screw axis direction in a state in which the head arm is positioned on the slider, and the second adjusting means moves the head arm on the slider in the rotation axis direction of the magnetic disk. The third adjusting means can move the magnetic head parallel to the recording surface of the magnetic disk on the head arm, and finely adjust in the rotational tangential direction of the magnetic disk. A magnetic disk device characterized by being present.