JPS60109090A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To facilitate maintenance and inspection by classifying control circuits of a magnetic disk device into three groups, arranging each group on one printed board, and arranging each printed board outside of the chassis of a device. CONSTITUTION:An index, a track position detecting, and a motor driving circuit, etc., are mounted on a printed board 65. Then, the read/write changeover switch, read amplifier, and write amplifier of a magnetic head are mounted on a substrate 113, and circuits which relate to interfaces and process signals from the substrates 65 and 113 are mounted on a substrate 114. Further, a connector 115 is provided to the substrates 65 and 113 and a connector 116 coupled with it is provided to the substrate 114 to make a connection among the substrates easily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a magnetic disk device, and more particularly to a magnetic disk device with an improved mounting structure for a printed circuit board on which electronic components are mounted.

[Prior Art] In general, control circuits for magnetic disk drives can be roughly classified into the following three groups.

(]) A group of digital circuits that handle digital signals with high voltages of 5V or more.

(2) Linear circuit group that handles weak signals below IV.

(3) Motor drive circuit group that handles high tonne currents.

In the past, several printed circuit boards were installed in the back of the device, using an appropriate space, to accommodate the electronic components that make up such a circuit group. In some cases, they were connected via a parallel wire or the like.

As a result, during maintenance or repair, many parts must be disassembled and removed before reaching the printed circuit board, which is extremely troublesome.

Another disadvantage is that lead wires and the like that connect the printed circuit boards require soldering work, which increases the number of assembly steps.

[1-1] The present invention has been made in order to eliminate the drawbacks of the conventional technology as described below. The present invention aims to provide a magnetic tisf device.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

The magnetic disk device according to the present invention is assembled with a chassis 1 as follows: 1. It is constructed as a U-shaped frame having right side plates 2, 2, and kite lines 3, 3 are formed at opposing positions of each side plate 2, 2 from the upper edge toward the center. Rollers projecting from the cassette i/guide side, which will be described later, are fitted into these kite grooves 3.3.

In addition, a kite hole 4 is formed in a horizontal state at the opposite position of the side plate 2.2 between the kite grooves 3.3, and the same A force/ite groove 5 is formed. These kite holes4. A kite roller of a slide frame, which will be described later, is fitted into the kite groove 5.

On the other hand, on the bottom plate 6 of the chassis 1, 16 dowel pins 7 are protruded from three positions at a predetermined arrangement δ.

These pins 7 position the cassette in a downward direction.

A pulse motor 8, which serves as a driving source for moving the magnetic head, is fixed to one end of the bottom plate 61 of the palm via stands 8a, 8a, and a protrusion 9 cut and raised from the bottom plate 6 is protrudingly provided near it. ing. A through hole 10 is formed in the protrusion 9, and the side plate 2 of
A through hole 11 is formed in. These through holes 10,
A guide shaft 12, on which a head holder (to be described later) is guided, is horizontally mounted using the il.

Further, on the near side of the chassis 1, another guide bar 13 is horizontally suspended between the side plates 2 and 2 in parallel with the guide shaft 12.

On the other hand, on the lower side of the pulse motor 8, an i.
A live gear 14 is fixed, and this drive gear 1
4 meshes with a gear 15 rotatably supported on the bottom plate 6''2.

A through hole 16 is formed approximately in the center of the bottom plate 6, and a rotational drive mechanism for the magnetic disk is connected to the through hole 16 at +til.
+ A supporting host 17 is installed.

As shown in FIG. 3, the boss 17 has a flange 17a on the outer periphery of its central part.This flange 17 is stacked on the "-" surface of the bottom plate 6, and the lower part of the boss 17 is fitted into the through hole 16, and the It is fixed via the flange 17a by the screw 18.

Inside this host 17 is the lower set of bearings 19.19
The rotary shaft 20 is rotatably supported through the shaft. -1, a collar 21 is arranged between the lower hair rings 19; The outer ring of the bearing 19.19 is press-fitted into the housing 17.

A coupler 22 is fixed to one -1 end of the rotating shaft 20. The coupler 22 is fitted into the center hub of the magnetic disk cassette, and a positioning pin 23 is fitted into the flange 22a of the coupler so as to be freely lowerable.

The lower end of the pin 23 is fixed to the free end side of the leaf spring 24 below the flange 22a, and is given the habit of always moving in the protruding direction.

A spring 25 is elastically loaded between the lower surface of the coupler 22 and the inner ring of the hair ring 19 on the negative side, and by pressing the inner ring downward, a relative positional shift is caused between the outer ring and the lower surface of the coupler 22. This creates uniform contact between the inner and outer rings and the pole, eliminates looseness between the inner and outer rings, and improves rotation.
This is to prevent vibrations from occurring.

The housing 1-11 is fitted to the housing 17 via a gear 27 or a housing 28 with the cam 26 facing upward. 7 Transmit to the upper side. A onesie 29 for tension & I is fitted on the outside of the post 28, and a stopper is provided to prevent the cam 26 and the like from being removed.

On the other hand, what is indicated by the reference numeral 30 is a head stand p formed in the shape of an elongated plate. One end of the head stand 30 is slidably fitted to the guide shaft 12 via a linear bearing 31.

The other end of the head stand 30 is slidably guided by another guide shaft 13.

That is, as shown in FIG. 5(C), a shaft 33 is provided on the free end side of the head stand 30 to project downward and rotatably support a circular roller 32 thereon. This shaft 33 and roller 3
A spring 34 is loaded between the roller 32 and the roller 32, giving the roller 32 the tendency to move in one direction.

Further, the shaft 33 is connected to the head stand 30a++i by a screw 35.
Although it is fixed to the head stand 30 by this screw 35,
One end of a plate spring 36 is fixed to the upper side of the plate.

The head base 30 whose sides are covered by this leaf spring 36
A roller 37 is rotatably fitted into the opening 30a formed in the opening 11 in a state perpendicular to the kite shaft 13.

Therefore, the guide shaft 13 is elastically held between the body surface of the circular roller 32 and the roller 30, and is slidably attached to the guide shaft 13.

The devices 12 and 13 that guide the movement of the head stand 30 in this way are devices that utilize rotational friction caused by linear bearings and rollers.
Since the 111 receiver uses a member, the friction is extremely small.
Compared to bearings that use sliding friction, the spatula/table can be moved much more smoothly.

Therefore, a small, low-power, inexpensive motor can be used as the pulse motor 8.

However, as shown in FIG. 5(B), the guide shaft 12 is guided by a member 38 that utilizes sliding friction, and the material of the bearing 38 is expensive but has extremely high wear resistance. For example, if a ruby or the like is used, an inexpensive pulse motor can be used.

Further, a spring 3 is provided between the head stand 30 and the protruding piece 9.
9 is stretched, giving the head stand 30 the habit of moving toward the rotating shaft 20 side.

The head 30 is disposed above the cam 26, and one end of the lever 40 is attached to the screw 4 on the back surface of the head 30.
It is rotatably supported by 1.

A spring 42 is stretched between the other end of the lever 40 and the head stand 30, and the first
In the figure, a counterclockwise rotational habit is given.

A roller 4 is connected to the bottom surface of this /<-41 via a pin 43.
4 is rotatably supported on a shaft, and this roller 44 is in contact with the cam surface of the cam 26.

By the way, as shown in FIG. 6, the cam 26 has a spiral shape as a whole and has a large number of serrated cam surfaces.The serrated cam portion has, for example, 40 tracks on a magnetic disk. In some cases, there are 40 corresponding cam parts.

In Fig. 6, each cam section is set so that the radius indicated by symbol RO is the maximum radius and the radius indicated by R39 is the minimum radius, and is arranged from the outermost track to the innermost radius of the magnetic disk. The magnetic head can be moved to the circumference of the track.

A pulse motor 8 rotates this cam, and its rotation is transmitted via gears 14, 15, and 27.

In reality, when one driving pulse is input to the pulse motor 8, the pulse motor 8 is set to rotate 18 degrees, and when a pulse with a positive phase is applied, the motor rotates clockwise, and when a pulse with an opposite phase is applied, the motor rotates clockwise. If you add , it will rotate to the left.

Also, when the pulse smoke 8 rotates 18 degrees, the gear 27 changes to 6.
The gear ratio of each gear 14, 15.27 is set to make 6 rotations, and within this 6° range, the radius is RO-R'
Forty 39 cam portions are formed.

Therefore, when the cam rotates 6 degrees, the magnetic head moves by one track, and the actual amount of movement is 0.1.
2mm, and the total width of all 40 tracks is approximately 5mm.
It is mm.

- As shown in FIG. 24, an adjusting screw 45 is screwed into the bent portion 30a which is provided midway in the longitudinal direction of the head stand 30.

The tip of this adjustment screw 45 is in contact with the bent portion 40a formed on the free end side edge of the lever 40, as shown in FIGS. You can ask questions.

Further, a rectangular opening 30b is formed in the middle of the head stand 30 in the longitudinal direction, and a support member 46 is provided in the opening 30b.
A magnetic head 47 is arranged via the magnetic head 47 .

An arc-shaped plate spring 49 is resiliently mounted between one end of the support member 46 and a protrusion 48 recessed into one end of the opening 30b. Projecting piece 50
The tip of the adjustment screw 51 that is axially aligned with the spring 49 is in contact with the side edge of the support member 46 on the side opposite to the spring 49 .

Therefore, by turning the adjustment screw 51, the position of the support member 46 and the position of the magnetic head 47 can be adjusted.

This adjustment screw 51 allows the center of the magnetic head to be adjusted correctly with respect to the center of the magnetic disk.

5. After adjusting its position correctly with the adjustment screw 51, the support member 46 is moved through the screw 52. It is only necessary to completely fix it to the board 30.

By the way, brackets 1-53, 53 are protruded from the end of the head stand 30 on the side of the guide 12, and by using these brackets 53, one end of the node 1\54 is connected via a pin 55. It is rotatably supported on the shaft. The pin 55 is wrapped with a torsion coil spring of 56 g.
The rotation behavior of the putt arm 54 in the direction 111r in FIG. 4 is made uniform.

The tip of the pad arm 54 extends to the upper part of the magnetic field 47, and the adjustment screw 57 is connected to the magnetic field 47 at its lower end. A knob 58 is provided for holding down the disc.

Therefore, by rotating the screw 57, the parallelism and butt pressure between the screw 58 and the magnetic head 47 can be adjusted six times.

A control plate 59 is integrally provided on the lower side of the gear 27, and a protrusion 59a is protruded from a part of the control plate 59, and a notch 59b is formed at the base of the protrusion 59a. ing.

A pin 6 is provided on the bottom plate 6 on the side of the control plate 59.
A lever 61 is rotatably supported on the shaft via the lever 61. One end of this lever 61 has a projection 61a with a predetermined interval rJl.
, 61b are formed, and these protrusions 61a, 61b
is always in contact with the outer circumference 1 m of the control plate 59.

The other end of the lever 61 is formed into an elongated shape, and faces a position that closes the 1- side of the notch 6a formed at the front edge of the bottom plate 6. and.

! A sensor 62 is placed facing the uJ cutout 6a. This sensor 62 is made up of a light emitting element and a light receiving element, and monitors the presence or absence of the lever 61 by receiving reflected light from the lower surface of -*11A of the lever 61 when angry.

and 0rode・shi/ゝ-61■matai・I' (rZ j
The following relationship exists between the end 1, the protrusion 59a, and the cam portion of the cam 26 having the maximum radius R○.

That is, when the roller 44 reaches the cam portion with the maximum radius RO, the projection 59a is set in a positional relationship that allows it to engage with the projection 6'lb of the lever 61.

Therefore, as shown in FIG. 6, when the roller 44 is at the cam portion with radius RI, the projection 61b of the lever 61 is replaced by the projection 59a.
It is not in contact with the sensor 62, and one end of the lever 61 is in contact with the sensor 62.
It is closed on three sides.

This situation! In this case, the protrusions 61a and 61b are in contact with the peripheral surface of the control plate 59, and the lever 61 does not rotate.

However, when the cam 26 is rotated an extra step by the pulse motor 8-, the roller 44 rides on the cam portion with the maximum radius RO, and the magnetic head 47, together with the head stand 30, corresponds to the outermost track position. It turns out.

At this time, as shown in FIG.
The lever 61 is rotated counterclockwise in the figure, and the projection 61b is fitted into the notch 59b. At this time, one end of the lever 61 is stiffened from the L side of the sensor 62 as shown in FIG. 7, the sensor 62 is turned off, and it is detected whether the magnetic head has reached the outermost track.

Therefore, the outermost track is the O track, and this position is 6
can be reliably detected by the above-mentioned mechanism, and the magnetic head is set to reach this position whenever the power is turned on.The head position at the start will be Ol-rank and -fi, If pulses are applied to the pulse motor 8 from this position, the trunk position can be freely selected, such as 5 pulses will move the head to 5 tracks, 10 pulses will move the head to the 10th track, and so on.

The current position of the magnetic head with respect to these pulse inputs may be stored in the memory of the digital processing system.

By the way, the specific specifications between the control plate 59 and the lever 61 are as follows.

That is, as shown in FIG. 6, the radius R of the control plate 59 is 15.
+nn+, rotation angle α of 1 step = 6°, moving hole N [δ = tan8°X15mff
= 1.6 mm.

Also, the distance pl [E
= 5mm, distance from pin 60 to rear end A-13m
m, the moving distance of the rear end of the lever 61 is 619, and the rotation angle is α
', then α' = 1515 X6 = 18°, δ1', tan 18°
becomes.

Therefore, when the peripheral edge of the ilMI' control plate 59 rotates by 1.6 degrees, the lever ratio of the 1/bar 61 is 3, so the lever 6e rotates by 18 degrees.

As a result, the outer end of the lever 61 is rotated by 4.2 mm,
If the size of the sensor 62 is 3 mm, the sensor surface can be opened and closed sufficiently.

Of course, if the sensitivity of the sensor 62 itself is increased, the protrusion 59a
A movement of about 1.6+n+n can be sufficiently detected, but by using the lever described above, f! i1”l
I can detect the movement of the control board at low cost.

If such a lever is used, the control plate 61 and therefore the cam 2
Since it is possible to detect 1'7 and Fi of 6 on the outside where other parts are not present, it is possible to obtain a detection mechanism that is less subject to locational restrictions.

By the way, a magnetic disk cassette is attached to the coupler 22 provided at one end of the rotating To 1120.

This magnetic disk cassette is made of synthetic resin, except for the center hub.

On the other hand, since the drive mechanism side of the magnetic disk is mostly made of metal, it is affected by thermal expansion.

The details are as follows.

That is, in FIG. 24(A), the distance from the center of the rotating shaft 20 to the center of the magnetic head 47, that is, a certain track, is 11, and the distance between the periphery of the center hub 63 and the rotating shaft 2 is 11.
If the distance between the centers of 0 is (<2, and the hole distance 1 from the periphery of the center hub 63 to the trunk is 13, then the part 12 is metal, and the part 3 is synthetic resin, specifically II 1
= 20m+n.

If fi 2 = 8 mm, recognition 3 will be 12 mm.

On the other hand, on the drive side, if the distance from the center of the rotating shaft 20 to the track is Ll, the contents are the distance NIL2 from the center of the rotating shaft 20 to the periphery of the post 28, the distance L3 from the honu 28 to the periphery of the cam 26, and the cam There is a distance L4 from the periphery of 26 to the track, and the bath part is made of metal.

Therefore, if L2 = 8mm and L4 = 1.5mm, L+ = 20mm, so L3 = 20-8-1
．． 5 = 10.5 mm.

Now, the temperature is 25°C, , ff1. If the error between the cents is zero, then the temperature is 20°C, I: '
When the temperature reaches 45°C, the following results are obtained.

In other words, the coefficient of linear expansion of metal is 18X IQ@3mm/
'The coefficient of linear expansion of C1 synthetic resin film is 17X 10'
-mm/°C, then ff1l,L is jJ+(1
+αt)=6, we get the following.

So, = f12 + j23 = (e + a X20X16XI
O'U)+ (12+ 12X 20X 17X 10
) = 20.043 mm T-1 = L 1 + L2 + L3 = (8 + 8
X20X 16X 10 hairs)+ (1,5+1.5
X20x16xlO″3)+ (10,5+ 10.5
X 20X 18X 10 condolences) = 20.0OB+n+
In other words, if the temperature rises by 20°C, the difference between Ll and ff1l will be deviated by 20.043-20.006 = 37 km, making it impossible to read the information on the air disk accurately.

Therefore, in the present invention, the material of the cam 26 is
Assuming that it is made of a synthetic resin with a coefficient of linear expansion that is approximately the same as 4, it is as follows.

L, = (8'+ 8 X 20X 16X 10
″3)+ (1,5+ 1.5X20X16XIO”)
+ (10,5+ 10.5X 20X 17X 10
”' ) = 20.038mm In other words, by changing the material of the cam, Ll and 721
cy) difference is 20.043-20.038'-=5 p
-m and naru.

Therefore, the influence of thermal expansion can be sufficiently reduced.

In the present invention, the center position of the magnetic head 47 and roller 44 can be determined by an adjusting screw 45.

Therefore, by observing the position of the magnetic head 47 using a microscope or the like, it is possible to accurately set the magnetic head 47 to 20 mm.

FIG. 24(B) shows that the positions of the centers of the magnetic head and roller 44 have shifted by an amount of δ.

Also, since the cam 26 is rotatable, the second
As shown in FIG. 4(A), there is a gap spanning δ between the boss 17 and the boss 28.

Therefore, when the cam 26 rotates, the gaps δ1 and δ2 between the bosses 17 and 28 constantly change, and the changes directly affect Ll.

In order to eliminate this influence, in the present invention, a spring 39 is stretched between the head stand 3o and the protruding piece to keep the gap δ1 between the bosses 17 and 28 on the magnetic head side to zero. It is always pulled toward the boss 28 side and pressed against one side by a spring 42, so that the magnetic hend position 1 is set so as not to deviate from the track.

On the other hand, the rotating shaft 20 extends below the chassis 1, and several members constituting the motor are connected to the printed circuit board 65 fixed to the lower side of the chassis 1.

That is, a coil 65a is fixed to the lower surface of the printed circuit board 1 by soldering.

On the other hand, a boss 66 is fixed to the lower end of the 1m rotating shaft 20, and a dish-shaped yoke 68 is attached to the boss 66 by a screw 67.
and gear 69 are fixed.

A ring-shaped permanent magnet 70 is fixed to the upper surface of the yoke 68, facing the coil 65a.

Further, a non-reflection plate 71 is fixed to the outer circumference of the yoke 68 and generates one pulse when the yoke rotates once, and a sensor 72 for detecting this is fixed to the printed circuit board 65 side.

Since the yoke 68 is plated with nickel, the sensor 72 consisting of a light emitting element and a light receiving element has a non-reflective plate 71.
can be reliably detected, and this signal can be used as an inte x signal.

On the other hand, what is indicated by the reference numeral 73 is a sensor which is connected to the printed circuit board 65.
It is fixed to the side and has a permanent magnet 74 and a yoke 75 continuous thereto, and the yoke 75 faces near the gear 69 as shown in FIG.

In FIGS. 1 and 3, the reference numeral 76 indicates an electronic component such as an LSI, and the reference numeral 77 indicates a screw for fixing the printed circuit board 65 to the chassis 1.

By the way, the gear 69 is made of iron-based material and has a large diameter, and when the tips of the teeth approach the yoke 75, a change in magnetic flux occurs and a current flows through the coil on the sensor 73 side, which can be taken out as a signal. I can do it.

The above-mentioned coil 65a and the permanent magnet 70 side constitute a motor for rotating the magnetic disk.

By the way, this motor is set to rotate at 200 m5 per revolution.

Then, in order to be able to rotate at a constant speed without wobbling during one rotation of this 200 m5, the 200 m5 is divided into small parts so that accurate rotation control can be performed.

In other words, the diameter of the gear 69 is 50 mm, the module is 0.25, and the number of teeth is 200, so 2
00m5-4-200 = sensor 73 at an interval of 1ms
The rotation changes are monitored.

Further, the printed circuit board 65 is a thin insulating board and is fixed to the iron chassis 1, and the magnetic flux generated by energizing the integrally provided coil 65a is formed between the shear'yl and the yoke 68. permanent magnet 70 and hence yoke 68 . Gear 69 is rotated.

By fixing the printed circuit board 65 to the iron chassis 1 in this manner, it becomes possible to narrow the distance between the magnet and the chassis for a long time, and the efficiency of the magnetic circuit decreases.

Furthermore, if the chassis 1 is made of an iron-based printed board, the thickness of the motor portion can be reduced by the thickness of the printed circuit board 65 constituting the motor, and the number of parts can also be reduced.

By the way, since the permanent magnet 70 is given a force to be attracted to the chassis 1 side, it is pressed in one direction by the inner ring of the lower bearing 19 or the post 66, so the bearing 1
It absorbs the backlash of 9 and rotates the rotating shaft 2 together with the bearing 19 on the L side.
0 swing can be prevented by 11-.

On the other hand, since the inner and outer diameters of the boss 17 fixed to the chassis 1 are machined at the same time based on the fixed part to the chassis 1, the inner and outer diameters can be machined to a length of about 1 to 2 meters.

Due to this precision and the absorption of the backlash of the bearing 19, the runout of the rotating shaft 20 including the host 17 can be maintained within 5 gm.

This concludes the explanation of the drive mechanism section, and the cassette loading mechanism section will be explained next.

The cassette loading mechanism employs the drawings shown in FIGS. 8 to 16.

That is, what is indicated by the reference numeral 78 in the figure is a sliding frame that is open at the bottom and front and back.

1 ljb of rollers 79 are rotatably supported on both sides of the slide frame 78, and these rollers 79 are slidable and inserted into the horizontal long holes 4 formed in the side plates 2.2 of the chassis l. They are rotatably fitted.

There are openings at the corners of the left and right ends of this slide frame 78.
+71! 78a is formed, and this opening 7
A projecting piece 78b is integrally provided on the ``-'' side of the slide frame 78, passing through the ``-'' side of the slide frame 78. A spring 80 is stretched between this protrusion 178b and a protrusion 2a protruding from the side wall of the chassis 1.

Therefore, a force is applied to the slide frame 78i in the direction of protruding it from the running chassis 1 toward the front side.

The protrusions protruding from the lower ends of both side plates of the slide frame 78 include
A roller 81 is rotatably supported on a shaft.
It can be slidably moved on the chassis 1 via.

A push button 82 is firmly fixed to a protrusion 78c protruding from one end of the slide frame 78.

Furthermore, there are oblique long holes 8 in the left and right side plates of the slide frame 78.
3 are formed in two parallel places.

A slide plate 8 is provided on the left and right inner surfaces of this slide frame 78.
4 are arranged so that they can slide freely.

The slide plate 84 is formed in a rectangular shape, and the end of the slide plate 84 is in contact with the bottom plate 6'' of the chassis 1.
Small diameter Tsukuda 1 part 81. It is in contact with a.

A protrusion 84a is provided at one end of the slide plate 84, and this protrusion 84 is fitted into the open I-shaped portion 78a of the slide frame 78 to serve as a guide.

Furthermore, a bent portion 84b that bends inward is formed at the tip of the slide plate 84.

Furthermore, on the slide plate 84, the slide) and the frame 78
An L-shaped opening 85 is formed at a position approximately corresponding to the elongated hole 83.

A projecting piece 84c is provided inside the tip of the slide plate 84, and a spring 8b is stretched between the projecting piece 84c and the slide frame 78.

By the way, below the slide frame 78 is a skein.

l.Kite 87 is placed.

The cassette guide 87 is formed as a flat frame body, and rail portions 87a that guide the cassette are provided on the left and right sides of the cassette guide 87.
is formed.

Further, projecting pieces 88 are provided on the left and right sides of the cassette guide 87, and pins 89 are provided on each of the projecting pieces 88, and a roller 90 is rotatably supported on these pins 89. .

Each roller 90 is connected to the slide plate 84. Slide frame 78
opening 85. It is rotatably fitted into the elongated hole 83.

Further, an opening 87b is formed in the center of the upper surface of the cassette guide 87, and a frame 91 is integrally provided across this opening 87b.
1, a hub presser 92 is removed.

Further, an opening 87c into which a magnetic head is fitted is formed on the side of the opening 87b.

The slide frame 78 described above. A cassette mounting mechanism is composed of three members: a slide plate 84 and a cassette guide 87.

Next, the operation of this cassette mounting mechanism will be explained.

Before the magnetic disk cassette 93 is installed, the slide frame 78 is moved to the right in FIGS. 8 and 13 by the longitudinal force of the spring 80.

In this state, the roller 90 is within the guide groove 3, located at the two-wheeled portion of the elongated hole 83 as shown in FIG. It is located in

That is, the roller 90 is connected to the kite groove 3. Long hole 83, opening 1
It is in a state where it is regulated by the part 85.

Further, the slide plate 84 is also moved by the spring 86 to the first position.
The cassette guide 87 is pulled to the right in Figure 3.
is in a position to receive a cassette at the upper position regulated by the stepped portion 85a.

In this state, when the cassette 93 is fitted into the rail portion 87a of the cassette guide 87, the cassette 93 is guided by the rail portion 87a and guided to the back.

Eventually, the tip of the cassette I/93 comes into contact with the bent portion 84b at the tip of the slide plate 84, and moves the slide plate 84 in the 111 direction against the tensile force of the spring 86.

Then, as the slide plate 84 moves, the opening '85 also moves, as shown in FIGS. ;It 8
The roller 90, which was located at point 5a, falls toward the vertical part of the opening 85, and as shown in FIGS. be guided below.

That is, the cassette 93 moves downward together with the cassette guide 87.

By the way, due to this cassette insertion operation, the roller 9
0 moves from the state located at the upper end of the long hole 83 as shown in FIG. 12(E) to the lower part of the long hole 83 shown in FIG. 12(F).

During this movement, the roller 90 pushes the right side edge of the elongated hole 83, so the slide frame 78 is moved a predetermined distance to the right as shown in FIG.

In this way, the cassette kite 87 together with the cassette 93
When the positioning pin 7 is lowered, the protrusion 7a of the pin with the protrusion 7a is fitted into the positioning hole 93a of the cassette I 93, and the - end of the pin 7 without the protrusion 7a is in contact with the bottom surface of the cassette, and the cassette support and position. This state is shown in FIG.

At this time, as shown in FIG. 11, the four-piece coupler 22 is fitted into the hub 95 in the center of the magnetic disk 94,
3 is fitted into a positioning hole 96 formed in the hub 95. Further, the upper surface of the hub 95 is held down by a hub presser 92.

This loading operation is performed with the rotation Ih1I2o being rotated.

When the cassette 93 is set in this manner, magnetic recording and reproduction are performed.

On the other hand, when it is desired to take out the cassette 93, the push button 82 is pressed and the slide frame 78 moves forward. Then, the peripheral edge of the inclined elongated hole 83 pushes the roller 90, so the roller 9o is pushed up, and the cassette guide 87 is also pushed up, returning to its original position.

When the cassette guide 87 reaches its second stop and the roller 9o also rises, it is located above the opening 85, so the slide plate 84
is moved to the right by the tensile force of the spring 86 as shown in FIG. 13, and the roller 9o moves to the horizontal part of the opening 85 and rides on the stepped part 85a. This slide plate 8
4, the bending portion 84b pushes the cassette 93, so the cassette 93 is pushed forward from the end of the cassette guide 87 and can be taken out.

By the way, the slide frame 78. The slide plate 84° cassette guide 87 is disposed inside the side plates 2, 2 of the chassis 1 in an assembled state as shown in FIG.
9,79a is a long hole 4. It can be easily assembled by simply fixing it to the side surface of the slide frame 87 with the screws 79b while it is fitted into the J cutout 5. Pat arm 5
Finally, a few pieces 4 may be placed on the head stand 30 side.

By the way, FIG. 19(A) shows a block diagram of the control circuit.

The magnetic disk device according to the present invention is controlled by a computer 100. This computer 100 and the magnetic disk drive side are connected by electric wires, and the input and output lines are connected by approximately 34 electric wires.

All of these 34 input/output lines are processed using digital signals.

On the other hand, the control circuit on the magnetic disk device side is shown in Figure 19 (A).
Broadly speaking, as shown in , there are pulse motor drive circuits for coupling with the computer 100, for amplifying and digitizing the outputs of the magnetic disk drive and various sensors, or for positioning the magnetic head on a predetermined track. It is mainly composed of the decile processing circuit +01.

This circuit +01 includes a read amplifier 102 which amplifies the signal read out from the magnetic head. light amplifier +03
, read/write switch 104. Indenrus amplifier 105. generates one pulse No. 148 when the magnetic disk rotates once. A track position detection amplifier 10G for detecting the track position of the magnetic head, a motor drive circuit 107 for rotating the magnetic disk once, and the like are connected.

Further, a speed control circuit indicated by the reference numeral 108 is a speed control circuit for controlling the rotation speed of the motor, and is connected to the motor drive circuit 107, and is connected to the signal lines 109 and 110 from the digital processing circuit 101, as will be described later. speed control is performed.

Further, the reference numeral 111 indicates an amplifier for monitoring the motor rotation speed.

What is indicated by the reference numeral 112 is a television.

By the way, in the present invention, based on the above-mentioned circuit configuration, in addition to performing general recording and playback at the same disk rotation speed, it is possible to perform high-speed recording and improve reliability. A structure is adopted that changes the motor rotation speed during recording and playback.

That is, first, when information to be recorded is input from the computer 100 as a command to the digital processing circuit 101, the circuit 101 inputs a signal to the changeover switch 104 to switch the magnetic head from the playback mode to the record mode, and at the same time starts writing. Let the amplifier 103 be in the operating state.

Further, after instructing the speed control circuit 108 to perform a low speed rotation operation via the signal line 110, confirming that the signal interval from the amplifier 111 and the speed control interval time match, and confirming that it is in a low speed rotation state, A recording signal from the computer 100 is input to record information on the magnetic disk.

Conversely, when a play command is issued from the computer side, the read/write switch 104 is switched to the read side, the read amplifier 102 is operated, the speed control circuit 108 is set to high speed mode via the signal line 109, and the amplifier After confirming that the motor is in a high speed rotation state via +11, reading of the record is started and the computer +00 is manually operated.

In addition, if you want to make the rotation speed the same during recording and playback, there is a step for setting the reference high speed rotation of the speed control circuit 108.
This can be processed by setting the U quasi-frequency to the same frequency as the low rotational speed.

Figure 19 (B) shows the rotation speed of the magnetic disk as 3ciorP.
The output characteristics are shown when the output of the magnetic head is measured when information is read by changing the speed from n+ to 60 Orpm.

Recording frequency f = 125kHz, disk rotation speed 3
11 with 0Orpm? ? Magnetic head output 0.8v
Adjust the rotation speed to 600 rpm using this point P as the origin.
When it was set to m, the magnetic field output was almost twice as high as the Q point.

Also, when the recording frequency f was doubled to 250kHz, the magnetic recording sound intensity increased, so the origin was about 25% of the P point.
Decreased outputs were obtained at three points, and when the number of revolutions was doubled in this state, point R, which had an output approximately twice that of the three points, was obtained.

Based on this output characteristic, if a magnetic disk is rotated at 30 Orpm and magnetic recording is performed at a frequency of 250 kHz, playback at that rotation speed will result in three points of 0.6v or 11j, but as stated in 111. When playing back 1, 1 te 1
:l: Set the rotary plate to 60Orpm at R point 1.
An output of 2■ was obtained.

In other words, a positive output voltage of 0.6V can be obtained, so even if there is a decrease in output due to variations in the characteristics of the magnetic disk or a decrease in output due to loss in the magnetic circuit of the magnetic head (such as fluctuation), digital processing is no longer possible. Sufficient output voltage has been achieved and reliability has been improved.

By the way, when recording the image signal of the television 112 on a magnetic disk, if the magnetic disk is set to 380 Orpm when recording one picture [m] of a cathode ray tube, it is possible to record one picture mi because it is synchronized with one field per track. can.

Note that one screen means one field, and is 1 second divided by 60 screens = 16.7 ms.

By the way, since the frequency at which television images are recorded on a magnetic disk is 6.1 MHz, the rotational speed of the rotor as explained in FIG. 19 (B) is 313 GO rpm -4-30 Or
When pm = 12 times, the output should increase, but the recording frequency becomes G, IMHz = 250kHz = 24 times, and the recording frequency increases and the amplifier output is approximately 0.4 to 0.
．． 5V, recording and reproducing television images on a magnetic disk can be reliably carried out by rotating the disk at high speed.

By the way, the control circuit shown in FIG. 19(A) is
The electronics i'Xl (the product is mounted on three substrates as shown in FIGS. 17 and 18).

That is, the aforementioned printed circuit board 65 and 113°114
It is.

The print board 65 is equipped with an index, track device detection, morph drive circuit, etc.

The board 113 also has a magnetic head read/write module J.
Equipped with 11 switches, lead, and write amplifiers,
], (The board 114 is equipped with an interface-related circuit for processing signals from each board 65, -113.

In addition, connectors 115 are provided on each of the boards 65 and 113.
A connector]/)G to be connected to these is provided on the board 114 side to allow easy connection between each store (My).

As shown in Figure 18, each board is mounted on the bottom and side surfaces of the chassis, so electrical signal adjustments and adjustments can be made simply from outside the chassis. In the event of a breakdown, the cylinder can be repaired by replacing the board.

By the way, a magnetic disk drive is used as a storage device for a computer, and in this case there are components around the device that generate strong magnetic fields, such as cathode ray tubes, single-source transformers, and motors, so it is necessary to protect the device from these magnetic fields. Is it necessary?

Therefore, in the present invention, the chassis 1 is formed into a U-shape, and its upper and side surfaces are made of iron slides I, a frame 78, a slide plate 84. It is covered with a cassette Kai-i-87 to block external magnetic fields and has a structure with a large magnetic shielding effect.

FIGS. 20(A) to 20(D) illustrate the trunk of a magnetic disk. Although FIG. 1 shows 8 tracks, in reality, 40 tracks can be recorded.

FIG. 20(B) shows an enlarged view of tracks [0 to 2], and the track width a is 50 gm.

]・Rack spacing is 70gm, l・, rack pitch is a
+b=120 g m.

In this way, when the track interval is larger than the track width, if it is possible to record between the tracks, the number of 40 tracks can be increased to 80, and the recording platform 1- can be doubled.

Figure 20 (C
, ).

In FIG. 20(C), a=5Q)hm.

b=lOpLm, ) Rack pitch is a+b=60
It is p-m.

By the way, when the track spacing is reduced in this way, magnetic recording interference occurs between adjacent tracks.

Therefore, in the present invention, as shown in FIG. 20(D), a method is adopted in which magnetic recording is performed by using two azimuth hands with different recording directions at an intersection lj.

For the magnetic disk shown in FIG. 20(D), the magnetic head 47 was shifted from the outer circumference toward the inner circumference at an interval of ]OpLm, and the reproduction output was measured, and the result was as shown in FIG. 21(A).

This reproduced output voltage is obtained by measuring the output of the read amplifier 102.Finally, this reproduced output voltage is input to a digital processing circuit, shaped into a 5V peak-to-peak pulse at TTL level, and connected to a computer or the like.

Therefore, when inputting the output of Fig. 21 (A) to a digital processing circuit, the input level is set to 0.4V so that the input is 0.
．． If the setting is such that a voltage of 4 V or higher generates a pulse, and a voltage lower than that does not generate a pulse, the amount of deviation between the center of the track and the magnetic head will be ±2 as shown in Figure 21 (A).
Even if there is a deviation of 5gm, a normal decile signal is generated.

Therefore, the vibration of the motor, the error in the radius of the cam 26, and the
The total amount of dimensional deviation due to expansion and contraction of the magnetic disk due to -4 degrees Celsius and humidity is allowed to be up to ±25 gm.

FIG. 21(B) shows the output when a track with the overtone degree shown in FIG. 20(C) is reproduced.

In FIG. 21(B), curve A represents the output characteristic of I rank [0] when no magnetic recording is performed on track [1], and curve B represents the output characteristic of track [0] when no magnetic recording is performed on track [0]. 1] shows the measured characteristics of the output.

When information is recorded in ranks [0], , [1] and measured by moving the magnetic head] from the track [0] direction to the track [1] direction, a curve C appears between curves A and H. The output shown in will be played.

In other words, information interference occurs.

When we measure the voltage in the diagonally shaded area surrounded by curves A, B, and C, we find that curves A and B are not completely summed to form curve C, but that other noise components have increased by 4. Ru.

Therefore, the portion of curve C does not provide accurate information.

In such a case, as shown in FIG. 21(B), the amount of deviation between the track and the magnetic head is 1/1 of that in FIG. 21(A).
The limit is approximately ±12 pm of 2, which means that the input level to the digital circuit must be set to 0.65 V.

That is, if an attempt is made to double the information sensitivity using the recording method shown in FIG. 20(C), the dimensional accuracy must be more than doubled, which requires high-precision and expensive parts.

Therefore, in the present invention, a recording method as shown in FIG. 20(D) described above was adopted.

In other words, the head caps are adjacent]・o for each rack
Recording was carried out using devices facing alternately in different directions, such as 1=o2.

Note that o,=o2=10 degrees.

The structure of such a magnetic lead is shown in Figure 22.

In FIG. 22, code 11? ' , +18 is a half core that constitutes one magnetic herad core, and a gap G1 having an angle of 01 is formed at the abutting portion of the two.

Further, those indicated by numerals 119 and 120 are half cores constituting the other magnetic core, and a gap G2 having an angle of 02 is formed at the abutting portion of the two cores.

These cores are supported by a core support 121, and a coil 122 is wound around the core halves 117 and 119.

b A support 1-121 is a glass material 12 that adheres between the cores.
It is made of a resin containing a large amount of glass material, which has an expansion coefficient almost equal to that of Sendust, which is the material of the core, and has a structure that can sufficiently withstand environmental changes such as vibration and temperature.

Now, after magnetically recording the same information on tracks 0 to 2, moving the head consisting of cores 117 and 118 shown in FIG. An output characteristic of curve A shown in FIG. 21(C) was obtained.

In the characteristic shown by curve A, the output voltage is small in the track [1] portion because the track [1] is recorded by a magnetic head having a slope gap of 02.

In other words, the gap where track [1] was recorded and the gap between the head passing through now are 20 degrees, so the output I
The noise component increases slightly.

On the other hand, if we move the head side consisting of half-core cores 119 and 120 from the outer circumferential direction to the inner circumferential direction of the track and determine the reproduction output voltage, we will obtain the song shown by the broken line in FIG. 21(C)! Get output like QB.

At this time, the optimum reproduction output voltage can be obtained in the track [1] portion.

In this way, the even-numbered digits of the track including 0 have gaps tilted by θ1, and the odd-numbered digits have camps tilted by 02.
Magnetic recording by the azimuth head ') i, , i'T
By performing this process, interference between magnetically recorded information between adjacent tracks is extremely reduced.

Therefore, if the input level is set to 0.4V, the deviation between the I-rack and the magnetic head described above will be allowed up to 25gm.

In this way, high-density recording using magnetic heads with the gap angle 0 facing in the opposite direction makes it easier to achieve mechanical accuracy, and the simple mechanism makes it easier to design and improve the performance of magnetic recording media. J diconversion will also increase.

23(A) and CB) are for explaining another example of the structure of the magnetic head. In this embodiment, the magnetic head 124 includes a set of semi-dead cores 125 separated by a predetermined distance.
, 126 are arranged, and the cores 125 and 128 have a thickness a of 50 pLm, a spacing of 2°5 II 1 m, and a gear pump G made up of the center studs is 0.1 gm. Crow welded coil 1 with
28 is advantageous by using the winding window 128.

When a magnetic head with such a structure is used, the magnetic head shown in Fig. 2.0 (
When recording as shown in B), the core half 125
Track [0 to 19 on the side, half off on the other core 126
can be used to record and reproduce tracks [20 to 39].

Therefore, when such a magnetic head FI 24 is used, in order to record and reproduce 40 tracks, the head stand 12 must be moved 20 steps by the pulse motor 8 to cover all of the recording and reproduction steps.

In this case, the number of stages of the cam 26 may be 20 stages.

For example, in the case of a magnetic head that has only - cores, when calculating the distance between tracks when you want to change it from track [0 to 20], the speed characteristic of a pulse motor is 3ms equals one track, so 20X 3ms = 60ms. Become.

Further, even when the magnetic head arrives at the 20th trunk, the pulse smoke 8 does not suddenly stop and vibrates slightly, so it is necessary to wait until it stops before recording or reproducing. Therefore, recording and playback cannot be started until after approximately 10 m5.

- When the head shown in No. 23M is adopted, after recording and playing back track "0", the head can be started immediately without any waiting time.
20] can be recorded and played back.

In addition, with a head with one core, the recording and playback time for the trunk [O~39] is 3ms
! i' III ) = 127 ms, whereas in the case of the head shown in FIG. 23, 3 ms X +! 3+
Since 10 (waiting time) = 67 ms, there is a difference of 60 m5, which indicates that higher speed can be achieved.

Next, the magnetic disk drive assembly applied to the magnetic disk drive according to the present invention will be explained.

As shown in FIG. 25, the cassette 93 consists of upper and lower cassette halves 130 and 131, and accommodates a magnetic disk 94 having a center hub 95 between them. Each cassette half has a through hole 132 into which the center hub 95 is fitted, and a head window 133 is formed therein.

Further, the reference numeral 34 indicates the cassette loading method with an arrow, and the reference numeral 135 indicates four parts on which labels 13B for writing the program name and the like are pasted.

Reference numerals 137 and 138 indicate positioning holes into which the projections 7a at the upper ends of the pins 7 are fitted.

By the way, what is indicated by the reference numeral 138 is a shack that is fitted to the outside of the cassette halves 130 and 131 that are placed together below 1.The shack has a cross section shaped like an opening, and is fitted so that it can swing freely by sandwiching it from the outside of the cassette. be done.

A projecting piece 141 is formed at one end of the shack 139 and is slidably fitted into a groove 140 formed on the upper surface of the shack 130 side.

Further, a bent portion 142 is formed facing inward at a position f-i facing the protruding piece 14+.

This bent portion 142 is fitted into grooves 143 and 144 formed in the upper and lower cassette halves, and guides the shutter 139.

Further, a 6-inch pin 145 is protruded from the innermost end of the groove 144 of the lower cassette half 131.
There is a spring 14 between the bent portion 142 and +iii.
6, which provides a force to draw the shaft 139 toward the center of the center half.

In addition, cassette) half 130, 131 I+? )14
3 and 144 are formed with lower step portions 147 for guiding the bent portions 142, respectively.

A quadrilateral four part 148 with which the shack 133 is in contact is formed on the outer surface of each of the center halves 130 and 131.

Further, the reference numeral 148 is a stop for removing the shank.

Further, a bent portion 8 designated by the reference numeral 150 is used to open a shutter protruding from the entrance end of the cassette guide 7 when the cassette is inserted into the cassette kite 87.
7d is a groove through which it passes.

As shown in FIG. 28, this bent portion 87d comes into contact with the edge 139a of the shutter 138 when the cartridge is attached.
Shutter 13 with head window 133 closed
Open 9.

FIG. 26(A) shows the state in which the shack is closed.

(B), and the opened state is shown in FIG. 26 (C).

Shown in (D).

The magnetic disk cassette used in the magnetic disk device of the present invention has the following two configurations, so that just by inserting it into the cassette guide on the device side, the shack, which is normally closed, can be opened automatically. Magnetic recording and reproduction can be performed reliably.

[Effects] As is clear from the following explanation, according to the present invention, the control circuit groups of the magnetic disk device are classified into 31'1 groups, each group is arranged on one printed X board, and The structure is simple and easy to assemble because each printed circuit board is placed outside the chassis of the device, and each printed circuit board is connected by a plug-in method via a connector.
It has the advantage of being extremely easy to maintain and inspect.

[Brief explanation of drawings]

The figures explain one embodiment of the present invention. Figure 1 is an exploded perspective view of the disk and head drive mechanism, fiTJ2 is a perspective view of the chassis with the head drive mechanism installed,
Figure 3 is a sectional view taken along the line A-A in Figure 2, and Figure 4 is a cross-sectional view taken along line B in Figure 2.
-E line sectional view, FIG. 5(A) is a sectional view showing one bearing structure of the head stand, FIG. 5(B) is a sectional view showing another example of the bearing structure, and FIG. 5(C) is a sectional view showing another example of the bearing structure. A cross-sectional view showing the structure of the other bearing of the head stand; FIG. 5 CD) is a cross-sectional view taken along the line C-C in FIG. Fig. 8 is an exploded perspective view of the cassette mounting mechanism, Fig. 9 is a perspective view of the assembled cassette mounting mechanism, and Fig. 10 is a cross section of the cassette mounting mechanism immediately after inserting the cassette. Figures 11 and 11 are cross-sectional views of the cassette loading mechanism in a fully loaded state, and Figure 12 (
A) to (A) are explanatory diagrams showing the operation of the rollers during the cassette mounting operation, FIG. 13 is a sectional view of the cassette mounting mechanism before the cassette is lowered, and FIG. 14 is a sectional view of the cassette mounting mechanism after the cassette is lowered. Figure 15 is a perspective view showing the relationship between the cassette loading mechanism and the chassis, Figure 16 is a perspective view of the chassis with the cassette loading mechanism removed, and Figure 17 is the layout of the board on which the control circuit is mounted. Fig. 18 is a side view of the chassis with the board exposed, Fig. 19 (l is a block diagram of the control circuit, and Fig. 19 (B) shows the relationship between the rotation speed of the media and the playback output. 20(A) is an explanatory diagram of tracks on a magnetic disk, FIG. 20(B) is an explanatory diagram of roughly recorded tracks, and FIG. 20(C) is an explanatory diagram of tracks recorded on cloth. , 20th
1Δ(D) is an explanatory diagram of the recording method adopted by the present invention, the second
1 (A) to (C) are diagrams showing reproduction output characteristics corresponding to the recording states shown in FIGS. 20 (B) to (D), respectively. FIG. 22 (A) is a plan view of the magnetic head; 22(B) is a sectional view taken along the line DD in FIG.
) is a cross-sectional view taken along the line E-E in Fig. 23 (A), and Fig. 24 (A)
, (B) are cross-sectional views and explanatory views explaining the details of the track positioning mechanism, and FIG.
26 (A) and CB) are the top and side views of the Jffi cassette with the shutter closed.
Figure 6 (C). (D) is a plan view and side view with the shutter open;
Figure 27 is an enlarged sectional view taken along line F-F of Figure 26 (A),
FIG. 8 is a perspective view illustrating the opening operation of the shutter. 65, 113.11.4... Printed circuit board 101.
...Digital processing circuit 102...Read amplifier 103...Write amplifier 104...Read/write switching switch 107...
・Motor drive circuit 108...Speed control circuit 115.116...Connector Figure 11 Figure 12 Figure 14/! :lQ 161 Rukyo, Omeumei7mk&- Figure 19 (A) Figure 20 (A) Figure 20 (B) Figure 21 (A) 1--- + 5. ．． I FJI fA 4 upper soμ
Stl- Fig. 21 (B) Ll ＋One, F simple edge- Do, Rikata, -Yan work station Fig. 21 (C) ±E and hill 1 Fig. 22 (A) Figure 22 (B) Figure 23 (A) Figure 23 (B) Figure 26 (A) η Figure 26 (B) +4't 139 Figure 26 (C) Figure 26 (D) +4Z IJ9

Claims (1)

[Claims] In a magnetic disk device that controls a magnetic disk device by computer, there is a printed circuit board equipped with an interface that connects to the computer side, a circuit group that digitally processes the amplified magnetic head (No. 13), and a morph that rotates the magnetic disk. A printed circuit board equipped with a drive circuit and a printed circuit board equipped with a circuit group for amplifying recording and playback signals are provided, each board is placed outside the chassis of the device, and each board is connected via a connector. A magnetic disk device (1Y1
゜