JP3551456B2 - Floppy disk drive - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a floppy disk device which is most suitable for recording and reproducing a floppy disk having a diameter of, for example, 3.5 inches.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a floppy disk device for recording and reproducing a floppy disk having a diameter of 3.5 inches, as shown in FIG. 14, is usually referred to as a normal PCB substrate at a lower front end side (arrow b direction side) of a chassis 100. A metal substrate (a circuit pattern formed of copper foil or the like on a sheet metal via an insulating layer) 101 is screwed from below with a plurality of screws 102, and the lower end of the chassis 100 (in the direction of the arrow a) is screwed. There is a printed circuit board (a circuit pattern formed of copper foil or the like on the upper and lower surfaces of an insulating plate) 103 which is a normal double-sided board, which is screwed from below with a plurality of screws 104.
[0003]
In a conventional floppy disk drive of this type, the components (spindle, spindle bearing, disk table, stator coil, rotor, rotor magnet, PG Magnet, PG sensor, FG pattern, Hall element, etc.).
[0004]
On the metal substrate 101, a drive circuit for the spindle motor 105, various switches such as a floppy disk recording capacity detection switch 106, a cassette-in switch 107, an erroneous erasure prevention detection switch 108, and a light emitting diode 109 are mounted.
[0005]
The printed circuit board 103 is provided with a logic circuit, a drive circuit for a stepping motor for transferring a magnetic head, a control unit including a recording and reproducing circuit for the magnetic head, an external interface 110, and the like.
[0006]
The metal substrate 101 and the printed circuit board 103 are connected by a connect cable 111.
[0007]
As shown in FIG. 14, a conventional large-sized printed circuit board 113 is screwed from below with a plurality of screws 114 into a whole area of a lower portion of the chassis 100. In some cases, a bearing, a disk table, a rotor, a rotor magnet, a rotor yoke, a PG magnet, and the like are mounted on the chassis 100, and a stator coil, a PG sensor, an FG pattern, a Hall element, and the like are mounted on the printed circuit board 113. Reference numeral 115 denotes a circular hole formed in the printed circuit board 113 for inserting a spindle or a spindle bearing above and below the printed circuit board 113.
[0008]
In this case, the drive circuit of the spindle motor 105, the various switches 106 to 109, the control unit, the external interface 110, and the like are all configured on the printed circuit board 113.
[0009]
[Problems to be solved by the invention]
However, the conventional floppy disk device shown in FIG. 14 has a large number of components mounted on the metal substrate 101 such as the components of the spindle motor 105, the drive circuit of the spindle motor 105, and various switches 106 to 109. The size of the metal substrate 101 becomes large so that the area occupies almost half of the lower surface of the chassis 100, and the shape becomes complicated. Accordingly, the cost of the floppy disk drive is increased because the metal substrate 101, which is more expensive than a normal printed circuit board, is extremely expensive. Further, since the metal substrate 101 becomes extremely heavy, the weight of the floppy disk device is increased, which causes disadvantages in handling and transportation.
[0010]
Further, in the conventional floppy disk drive shown in FIG. 15, the components of the spindle motor 105 must be divided into two parts and mounted on the chassis 100 and the printed circuit board 113. There were problems such as being expensive.
[0011]
The present invention has been made in order to solve the above problems, and can achieve simplification of the structure, weight reduction, and cost reduction. In addition, maintenance such as assembly, inspection and repair is easy. It is intended to provide a floppy disk drive.
[0012]
[Means for Solving the Problems]
A floppy disk drive of the present invention for achieving the above object is detachably screwed to a lower portion of a chassis from below. Printed board And above Through the opening formed in the printed circuit board, from below the printed circuit board Lower part of the above chassis Prolapse Screwed so that it can be worn Metal substrate And only the components of the spindle motor are mounted on the metal substrate, and at least a drive circuit for the spindle motor and the stepping motor, a recording and reproducing circuit for the magnetic head, various switches, and an external interface are mounted on the printed circuit board. It is.
[0013]
[Action]
The floppy disk device of the present invention configured as described above is detachably screwed to the lower portion of the chassis from below. A drive circuit for a spindle motor and a stepping motor, a recording / reproducing circuit for a magnetic head, various switches and an external interface, etc. are mounted on the printed circuit board, and through an opening formed in the printed circuit board, from below the printed circuit board. Shah To Removably screwed Only the components of the spindle motor are mounted on the metal substrate, The drive circuit of the spindle motor, which should be mounted on a metal substrate, is mounted on a printed circuit board. Because The size of the metal substrate can be significantly reduced.
[0014]
【Example】
An embodiment in which the present invention is applied to a floppy disk device using a 3.5-inch floppy disk will be described below with reference to FIGS.
[0015]
[Overview of floppy disk drive]
First, the outline of the floppy disk device will be described with reference to FIGS.
[0016]
A floppy disk device 1 as an example of a disk device records and reproduces a floppy disk 2 composed of a magnetic disk having a diameter of 3.5 inches, which is an example of a disk-shaped recording medium. The floppy disk 2 is a flat disk. The cartridge 3 is rotatably stored in the cartridge 3 for use. The disk cartridge 3 has a pair of upper and lower head insertion openings 3a, and a shutter (not shown) for opening and closing the head insertion opening 3a is attached.
[0017]
The floppy disk drive 1 includes a chassis 5 formed of a sheet metal, a cover 6 formed of a sheet metal thinner than the chassis 5 and mounted on an upper portion of the chassis 5, and a chassis 5 and a cover 6 formed of a synthetic resin. It is formed in a flat box shape by three exterior members with a front panel 7 attached to the front end of the box.
[0018]
The front panel 7 has a cartridge insertion slot 7a, and a printed board 8 and a metal board 31, which will be described later, are screwed to the lower surface of the chassis 5.
[0019]
A cartridge holder 9 is horizontally disposed above the chassis 5 inside the floppy disk drive 1 and has a conventionally known holder elevating mechanism 10 having an upwardly-facing slide plate 10a having a substantially U-shaped cross section. The cartridge holder 9 is mounted on the chassis so as to be able to move up and down by parallel movement. A shutter opening / closing lever 9a is attached to the rear end of the cartridge holder 9, and an eject button 10b attached to the front end of the slide plate 10a protrudes forward of the front panel 7.
[0020]
The chassis center P inside the floppy disk drive 1 ₁ A spindle motor 11 horizontally mounted on a metal substrate 31 is arranged at a lower position of the cartridge holder 9 above, and is formed on an upper end of a vertical spindle 11a of the spindle motor 11 on an upper end of a rotor of the spindle motor 11. The disk table 12 is fixed horizontally.
[0021]
A head moving device 14 mounted on the chassis 5 is disposed inside the floppy disk device 1 behind the disk table 12.
[0022]
The head moving device 14 includes a head carriage 15, a head arm 17 mounted on the upper part thereof so as to be rotatable up and down via a leaf spring 16 and the like, and an upper and lower opposing surface of the head carriage 15 and the tip of the head arm 17. A pair of upper and lower magnetic heads 18 which are heads mounted to face each other up and down, a horizontal lead screw 20 directly connected to a motor shaft 19a of a stepping motor 19, a horizontal guide shaft 21 parallel to the lead screw 20, and the like. It is constituted by. Note that the pair of upper and lower magnetic heads 18 is ₁ Is placed on top.
[0023]
A needle 15a formed on one side of the head carriage 15 is engaged on the lead screw 20, and a thrust bearing 15b formed integrally on the other side of the head carriage 15 slides on the outer periphery of the guide shaft 21. It is freely inserted.
[0024]
The upper magnetic head 18 is inserted into a notch 22 formed in the center of the rear end of the cartridge holder 9, and a guided protrusion 17 a integrally formed on one side surface of the head arm 17 is provided in the cartridge holder 9. The holder 9 is slidably abutted on a guide rail 9 b formed on one side edge of the notch 22 of the holder 9.
[0025]
[Recording and playback operation of floppy disk]
The floppy disk device 1 is configured as described above. When the disk cartridge 3 is inserted horizontally into the cartridge holder 9 from the cartridge insertion opening 7a of the front panel 7 in the direction of the arrow a, the disk cartridge 3 is opened by the shutter opening / closing lever 23. The shutter 3 is opened, and at the same time, the slide plate 10a of the holder elevating mechanism 10 is slid in the direction of arrow b, and the cartridge holder 9 is lowered horizontally. Then, the disk cartridge 3 is lowered horizontally, the internal floppy disk 2 is chucked from above by the center core 2a on the spindle 11a and the disk table 12, and a pair of upper and lower magnetic heads 18 are formed on the disk cartridge 3. The disk cartridge 3 is inserted into the disk cartridge 3 from the pair of upper and lower head insertion holes 3a and comes into contact with the upper and lower surfaces of the floppy disk 2.
[0026]
Then, while the floppy disk 2 is driven to rotate by the spindle motor 11, and the head carriage 15 is guided by the guide shaft 21, the head carriage 15 and the head arm 17 are integrally moved by the lead screw 20 which is driven to rotate by the stepping motor 19. By moving the floppy disk 2 in the directions a and b, recording and reproduction are performed on the upper and lower surfaces of the floppy disk 2 by the pair of upper and lower magnetic heads 18.
[0027]
When the eject button 10b is pressed in the direction of arrow a after recording and reproduction, the slide plate 10a of the cartridge lifting mechanism 10 slides in the direction of arrow a, and the cartridge holder 9 is raised horizontally. Then, the disk cartridge 3 is raised horizontally, the internal floppy disk 2 is separated upward from the spindle 11a and the disk table 12, and the pair of upper and lower magnetic heads 18 is separated vertically from the disk cartridge 3. The disk cartridge 3 is ejected from the cartridge insertion opening 7a of the front panel 7 in the direction of arrow b by the shutter opening / closing lever 9a.
[0028]
[Description of assembly structure of chassis and cover]
Next, an assembly structure of the chassis 5 and the cover 6 will be described with reference to FIGS.
[0029]
First, the chassis 5 has a bottom plate 5a, a pair of left and right side plates 5b, and a rear plate 5c formed integrally by press working. Have been.
[0030]
The cover 6 has a top plate 6a, a pair of left and right side plates 6b, and a rear plate 6c formed integrally by press working. Have been.
[0031]
A pair of left and right dowels 24 as fixing means are formed outside the front ends (ends on the front panel 7 side) of the pair of left and right side plates 5b of the chassis 5 by drawing or the like. A pair of left and right cutouts 25 as fixing means are formed at the front end (end on the front panel 7 side) of the side plate 6b.
[0032]
Also, a pair of left and right screw insertion holes 26 is formed at the left and right ends on the rear end (the end opposite to the front panel 7 side) of the top plate 6a of the cover 6 by drawing or the like. A pair of left and right screwing projections 27 integrally formed by press working on the inside of the upper end edges on the rear ends (ends opposite to the front panel 7 side) of the pair of side plates 5b are tapped. A pair of left and right screw holes 28 are formed.
[0033]
Then, the cover 6 is fitted to the chassis 5 from above, and the pair of left and right side plates 6b and the rear plate 6c of the cover 6 are fitted to the outside of the pair of left and right side plates 5b and the rear plate 5c of the chassis 5.
[0034]
After the pair of left and right notches 25 of the cover 6 are fitted into the pair of left and right dowels 24 of the chassis 5, the pair of left and right stoppers as fixing means inserted from above into the pair of left and right screw insertion holes 26 of the cover 6. The screws 29 are screwed into the pair of left and right screw holes 28 of the chassis 5 and fastened, and the peripheral portions of the pair of left and right screw insertion holes 26 of the top plate 6 a of the cover 6 are fixed with the pair of left and right screws of the chassis 5. This is fixed on the projection 27.
[0035]
After that, if the front panel 7 is attached to the front ends of the chassis 5 and the cover 6 by a fitting method, a series of assembly of the floppy disk device 1 is completed.
[0036]
According to the assembly structure of the chassis 5 and the cover 6, the reinforcing member of the chassis 5 can also be used by the cover 6, and the torsional rigidity of the chassis 5 is greatly improved.
[0037]
Therefore, distortion and bending of the chassis 5 can be prevented as much as possible, and increase in off-track and displacement of 00 (zero-zero) track due to distortion and bending of the chassis 5 can be prevented.
[0038]
Further, since the cover 6 can be fixed to the chassis 5 without any backlash, there is no adverse effect such as vibration or impact due to backlash of the cover 6, and the recording and reproducing characteristics can be improved.
[0039]
In addition, of the four fixing points of the cover 6 with respect to the chassis 5, two of the fixing points are engaged with the dowels 24 and the notches 25, and only the remaining two are screwed with the set screws 29. The cover 6 can be easily attached and detached.
[0040]
Note that the number of fixing points of the cover 6 to the chassis 5 may be more or less than the above-mentioned four places. These fixing points can be fixed by various fixing means such as snap pins, caulking and welding.
[0041]
[Description of printed circuit board and metal board]
Next, the metal substrate 31 and the printed circuit board 8 attached to the lower surface of the bottom plate 5a of the chassis 5 will be described with reference to FIGS. 1 to 6, 10 and 12.
[0042]
[Description of printed circuit board]
First, a normal printed circuit board (a circuit pattern formed of copper foil or the like on the upper and lower surfaces of an insulating plate) 8 formed of a double-sided substrate is formed along the entire area of the bottom plate 5a of the chassis 5 and is provided at the front end. A switch mounting portion 8a formed in a small width A, a control portion 8b formed in a large width B in a region about half of the rear end side, and one side of the switch mounting portion 8a and the control portion 8b. The connecting portion 8c that connects the spaces with a small width C forms a substantially U-shape as a whole. Therefore, a substantially U-shaped notch 8d is formed between the switch mounting portion 8a and the control portion 8b beside the connecting portion 8c.
[0043]
Switches such as a recording capacity detection switch 106, a cassette-in switch 107, an erroneous erasure prevention detection switch 108, and a light emitting diode 109 are mounted (mounted) on the switches mounting portion 8a of the printed circuit board 8. I have.
[0044]
A logic circuit, drive circuits for the spindle motor 11 and the stepping motor 19, control circuits such as a magnetic head recording / reproducing circuit, an external interface 110, etc. are mounted on the upper and lower surfaces of the control section 8b of the printed circuit board 8. I have. The switch mount 8a and the control unit 8b are electrically connected by a connecting unit 8c.
[0045]
The printed circuit board 8 is screwed to the lower surface of the bottom plate 5 a of the chassis 5 from below by a plurality of setscrews 13.
[0046]
By the way, as described above, in the floppy disk device 1, switches such as a recording capacity detection switch 106, a cassette-in switch 107, an erroneous erasure prevention detection switch 108, and a light emitting diode 109 are arranged at the front end of the chassis 5 (in the direction of the arrow b). Since the external interface 110 is arranged behind the rear plate 5c of the chassis 5, it is very effective to form the printed circuit board 8 in a substantially U-shape.
[0047]
[Description of metal substrate]
Next, a metal substrate (having a circuit pattern formed of copper foil or the like on a sheet metal via an insulating layer) 31 is Is an opening The substrate is formed in a small, lightweight, and substantially square substrate having a simple shape that can be sufficiently accommodated in the notch 8d.
[0048]
Only the components of the spindle motor 11 are mounted on the metal substrate 31.
[0049]
That is, the spindle bearing 11b is screwed to the center of the metal substrate 31 from below by a plurality of small screws 11c, and the spindle 11a is rotatably supported by the spindle bearing 11b. The disk table 12 is integrally formed on the upper end of the rotor 11 fixed to the outer periphery of the spindle 11a by press-fitting or the like, and the rotor magnet 11e, the PG magnet 11f, etc. It is fixed.
[0050]
A plurality of stator coils 11g, an FG pattern 11h, a PG sensor 11i, a Hall element (not shown), and the like are mounted and formed on a metal substrate 31 on the outer periphery of the spindle 11a.
[0051]
The metal substrate 31 is electrically connected to the control section 8b of the printed circuit board 8 by a connect cable 111.
[0052]
[Mounting structure of metal substrate]
Then, the spindle motor 11 is inserted from below into a circular motor insertion hole 32 formed in the bottom plate 5 a of the chassis 5, and the metal substrate 31 is lowered to the lower surface of the bottom plate 5 a by three set screws 33. It is screwed from.
[0053]
At this time, three motor mounting bases 34 formed in a substantially trapezoidal shape by cutting and raising downward are formed at approximately three equally spaced positions around the circular motor insertion hole 32 of the bottom plate 5 a of the chassis 5. ing.
[0054]
At this time, the cuts 35 are formed in the bottom plate 5a on the side opposite to the inner peripheral edge 32a of the motor insertion hole of each of the three motor mounts 34, so that the three motor mounts 34 can be easily and precisely cut and raised. The lower surface 34a of each of the three motor mounts 34 can be made more horizontal.
[0055]
In the center of the lower surface 34a of each of the three motor mounts 34, a threaded screw hole 36 is formed.
[0056]
Then, three setscrews 33 are inserted from below into the three screw insertion holes 37 formed in the peripheral portion of the metal substrate 31, and screwed into the screw holes 36 of the three motor mounts 34 to fasten. The metal substrate 31 can be screwed extremely stably to the lower surface 34a of the three motor mounting bases 34 by the three-point support method, and the metal substrate 31 is hardly distorted at the time of screwing.
[0057]
At this time, by aligning the positioning reference portion 38 such as a notch formed on the outer periphery of the metal substrate 31 with the positioning reference 39 such as a pin formed on the lower surface of the bottom plate 5a, the metal substrate 31 can be accurately positioned on the bottom plate 5a from below. Can be screwed on.
[0058]
Since the horizontality of the lower surfaces 34a of the three motor mounts 34 is high, the verticality of the spindle 11a of the spindle motor 11 is highly accurate.
[0059]
According to the metal substrate 31 configured as described above, all of the components of the spindle motor 11 can be mounted on the metal substrate 31 that is one mounting member. Easy to assemble.
[0060]
Since only the components of the spindle motor 11 are mounted on the metal substrate 31, the expensive metal substrate 31 can be formed in a small, light, and simple shape.
[0061]
[How to remove printed circuit boards]
Next, as shown in FIG. 7, since the printed circuit board 8 is formed in a substantially U-shape, at the time of removing the printed circuit board 8, the two printed circuit boards 8 are inserted into these notches 8d. By assembling these control parts 8b in the opposite directions so as to be inserted into each other, it is possible to remove the wasteful two-piece assembly board 80 having a substantially square shape as a whole. Note that 80a is a discarded substrate, and 80b is a cut-off line.
[0062]
[Comparison of printed circuit board shapes]
The printed board 81 shown in FIG. 8A has a large board area and is wasteful.
[0063]
The printed circuit boards 82 and 83 divided into two shown in FIG. 8B must be connected by a connect cable 84, and the work of soldering the connect cable 84 is also necessary.
[0064]
The substantially U-shaped printed board 8 of the present invention shown in FIG. 8C has a small board area and does not require a connect cable.
[0065]
Then, the substantially U-shaped printed circuit boards 8 can be combined as shown in FIG.
[0066]
As described above, one embodiment of the present invention has been described, but the present invention is not limited to the above-described embodiment, and various modifications can be made based on the technical idea of the present invention.
[0067]
【The invention's effect】
The floppy disk drive of the present invention configured as described above has the following effects.
[0068]
According to the first aspect of the present invention, the lower part of the chassis is detachably screwed from below. A drive circuit for a spindle motor and a stepping motor, a recording / reproducing circuit for a magnetic head, various switches and an external interface, etc. are mounted on the printed circuit board, and through an opening formed in the printed circuit board, from below the printed circuit board. Shah To Removably screwed Only the components of the spindle motor are mounted on the metal substrate, The drive circuit of the spindle motor, which should be mounted on a metal substrate, is mounted on a printed circuit board. Because Since the size of the metal substrate can be significantly reduced, the structure of the spindle motor is simple, and the manufacture and assembly are easy. Further, the size, weight, and cost of the metal substrate can be reduced, which is advantageous for handling and transporting the floppy disk device.
[0069]
In addition, claim 1 is a metal substrate But Printed board Through the opening formed in the printed circuit board from below At the bottom of the chassis It is detachably screwed, and the work of attaching and detaching the metal substrate and the printed circuit board to and from the chassis can be performed separately without being restricted by each other. Therefore, at the time of assembly, these metal substrates When Printed board When At the bottom of the chassis Separately, Easy to assemble. Also, during maintenance, these metal substrates When And printed circuit boards When To the bottom of the chassis Separately, Inspection and repair of spindle motor components mounted on metal substrates, drive circuits mounted on printed circuit boards, recording and reproduction circuits of magnetic heads, various switches and external interfaces, etc. Maintenance can be easily performed.
[0070]
Claim 2 as well as 3 Since a plurality of motor mounting bases cut and raised on the lower surface of the chassis are provided, the metal substrate is screwed to the plurality of motor mounting bases from below, and the motor mounting base is formed in a substantially trapezoidal shape. In addition, the motor mounting base can be processed with high precision and easily, so that the horizontality of the metal substrate can be increased and the verticality of the spindle motor can be increased.
[0071]
Claim 4 Since the printed circuit board is formed in a substantially U-shape and the metal substrate is arranged in the substantially U-shaped notch, a recording capacity detection switch, a cassette-in switch, an erroneous erasure prevention detection switch, a light emitting diode It is very easy to arrange switches and external interfaces before and after the floppy disk device, and it is very easy to arrange a metal substrate in the substantially U-shaped notch of the substantially U-shaped printed circuit board. It is valid. Moreover, the substantially U-shaped printed circuit board is also effective for board cutting.
[Brief description of the drawings]
FIG. 1 is a bottom view of a floppy disk device according to an embodiment of the present invention.
FIG. 2 is a partially cutaway side view of FIG. 1;
FIG. 3 is a bottom view in a state where a metal substrate and a printed circuit board in FIG. 1 are removed.
FIG. 4 is a partially cutaway plan view of a spindle motor.
FIG. 5 is a partially cutaway plan view of the chassis.
FIG. 6 is an exploded perspective view of the metal substrate and the chassis as viewed from below.
FIG. 7 is a plan view showing the removal of a printed circuit board.
FIG. 8 is a drawing comparing the shapes of printed boards of various shapes.
FIG. 9 is a perspective view of the entire floppy disk device.
FIG. 10 is an exploded perspective view of a chassis and a cover of the floppy disk device.
FIG. 11 is a plan view of the floppy disk drive with a cover removed.
FIG. 12 is a plan view of the floppy disk drive with a cover and a cartridge holder removed.
FIG. 13 is a schematic sectional view taken along the line AA of FIG. 10;
FIG. 14 is a bottom view showing an example of a conventional floppy disk device.
FIG. 15 is a bottom view showing another example of the conventional floppy disk device.
[Explanation of symbols]
1 floppy disk drive
2 Floppy disk
3 disk cassette
5 Chassis
5a Bottom plate of chassis
8 Printed circuit board
8a Switch mounting part of printed circuit board
8b Control part of printed circuit board
8c Connection part of printed circuit board
8d Notch of printed circuit board
11 Spindle motor
11a Spindle motor spindle
11b Spindle bearing of spindle motor
11d Spindle motor rotor
11e Rotor magnet of spindle motor
11f PG magnet for spindle motor
11g Spindle motor stator coil
11h FG pattern of spindle motor
11i PG sensor of spindle motor
18 Magnetic head
31 metal substrate
32 Motor insertion hole
33 Set screw
34 Motor mount
35 cut
80 two-piece board
106 Recording capacity detection switch
107 Cassette-in switch
108 Erroneous erase prevention detection switch
109 light emitting diode
110 External interface
111 Connect Cable

Claims (4)

A printed circuit board screwed to the bottom of the chassis so that it can be detached from below,
Through openings formed in the printed circuit board, and a metal substrate that is desorption can screwed into the lower portion of the chassis from below the printed circuit board,
Only the components of the spindle motor are mounted on the above metal substrate,
A floppy disk drive wherein at least a drive circuit for a spindle motor and a stepping motor, a recording and reproducing circuit for a magnetic head, various switches, and an external interface are mounted on the printed circuit board. A plurality of motor mount that is processed and raised off the bottom surface of the chassis is provided, floppy disk drive according to claim 1, wherein the metal substrate is characterized in that tanning screwing from below to the plurality of motor mount. Floppy disk drive according to claim 1 Symbol mounting characterized by being formed into a substantially trapezoidal shape the motor mount. To form the printed circuit board in substantially U-shape, the substantially U-shaped, characterized in that a said metal substrate in a notch claim 1 Symbol placement of the floppy disk drive.

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