JPH0249277A - Recording or reproducing device - Google Patents

Abstract

PURPOSE:To improve positioning accuracy by simplifying and miniaturizing mechanism by arranging a head traveling cam coaxially with a spindle shaft to rotate a magnetic disk, and providing a head position adjusting means on a head carriage. CONSTITUTION:The spindle shaft 8 of a motor is arranged on a pedestal 6 perpendicularly, and the magnetic disk is rotated. A carriage 11 is fitted in the rails 9 and 10 of the pedestal 6 slidably freely, and is pressed to the shaft 8 side with springs 12 and 13. A magnetic head 14 is fixed at the carriage 11, and a roller 15 which performs tracking interlocking with a positioning mechanism is mounted on the front lower plane of the head. When a pulse is added on a pulse motor 16 on one side of the pedestal 6, the stepping of the pulse turns a gear 39 coaxial with the spindle shaft 8 and a specific cam 40 via gear train (17-19), and the carriage 11 is moved by prescribed tracks, and the roller 15 mounted on a screw shaft eccentrically is rotated, thereby, fine position adjustment can be performed. By employing such constitution, it is possible to realize the simplification of a disk driving system and a head traveling mechanism, and the miniaturization of the device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording or reproducing device such as a magnetic disk device, and more particularly to a small magnetic disk device using a small magnetic disk.

Floppy disk devices, which are widely used as storage devices using magnetic disks, are used in various electronic devices such as robot equipment, personal computers, word processors, electronic typewriters, and pocket computers, and are useful for increasing the added value of these devices. There is.

With the miniaturization of devices in this type of magnetic disk device, for example, magnetic recording media with a diameter of about 50 mm, that is, magnetic disks (floppy disks) are used, and small magnetic disk devices are used to enable high-density recording. Demand for discs is increasing.

However, in order to realize such a small magnetic disk device, a disk drive system that rotates the magnetic disk, a head movement mechanism that moves the head relative to the magnetic disk to change the recording or reproduction track position, etc. Regardless of the method, the structure tends to become more complex and the size of the device tends to increase.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and to provide a magnetic disk device that can be made smaller by greatly simplifying the configuration, and can achieve higher head positioning accuracy.

In order to achieve the above object, the present invention employs a structure in which a cam for moving the head is arranged coaxially with the spindle shaft that rotates the magnetic disk, thereby simplifying and downsizing the mechanism and A head position adjustment means is disposed on the carriage to improve head position accuracy.

The present invention will be described in detail below based on the drawings.

FIG. 1 and the following illustrate a magnetic disk device to which the present invention is applied, and FIG. 1 shows an exploded schematic configuration thereof.

The magnetic disk device according to the present invention includes a base portion l, a position detection mechanism 2, a holder portion 3, a disk holding mechanism 4, and an E.
The magnetic disk can be roughly divided into five parts: a magnetic disk cassette 5 (hereinafter, the magnetic disk will be referred to as a floppy disk).

The base l constitutes the main part of the floppy disk device, and is provided with a magnetic recording/reproducing head and a driving source.

The position detection mechanism 2 detects the track position and detects the track position.
A floppy disk cassette (hereinafter abbreviated as cassette) 5 is removably installed, and serves to correctly guide the floppy disk to a head provided on the base side.

Further, the disk holding mechanism 4 exerts a pressing force on the floppy disk, and serves to bring the head and the floppy disk into contact with an appropriate pressing force.

The details of each part will be sequentially explained below.

The base section 1 is assembled with a base 6 as a reference, and is provided with a motor 7 for rotating a floppy disk, the output shaft 8 of which is arranged vertically.

Two guide rails 9. are mounted on the base 6 so as to sandwich the motor 7 therebetween. The IOs are horizontally suspended in parallel, and these guide rails 9. A carriage 11 is slidably fitted into the IO. The guide rail 9.10 has a coil spring 12.
13 is attached to apply a pressing force to the carriage 11 in a direction toward the output shaft 8 of the motor 7.

A magnetic head 14 for recording and reproducing is fixed on the carriage 11, and a roller 15 that performs tracking in conjunction with a positioning mechanism to be described later is attached to the lower surface on the front side of the magnetic head 14.

A pulse motor 16 for driving the head is attached to one corner of the base 6, and a gear 17 fixed to its output shaft is a gear 1 rotatably supported near the pulse motor 16.
It meshes with 8. The pinion gear 1 is located on the underside of the gear 18.
9 is integrally provided.

A printed circuit board 20 is attached to the upper side of the motor 7 while avoiding the pinion gear I9 and the output shaft 8 of the motor 7. This printed circuit board 20 has a through hole 20a at one corner, and this through hole 20a is fitted into a pin 21 protruding from the base 6, and the top and bottom of the pin 21 are sandwiched between °E rings 22 and fixed. .

The corner facing the through hole 20a is fixed to the upper end of the side wall 24 of the base 6 with a screw 23, and the other end is also fixed to the base 6 via a screw.
fixed to the side wall or partition wall soil.

Photodetectors 25 and 26 each consisting of a light receiving element and a light emitting element are attached to the upper and lower parts of the printed circuit board 20.

By the way, the motor 7 has a structure as shown exploded in FIG. As shown in Figure 4, a permanent magnet 28.29
are fixed at equal angular intervals. These permanent magnets 28.2
No. 9 is molded from synthetic resin mixed with a magnetic phase, and is excellent in mass production. The output shaft 8 is fixed to the rotor 27, and the output shaft 8 has two bearings fixed to the yoke 30, upper and lower bearings 32a fixed to the holder 31,
It is rotatably supported on the shaft 32b. Reference numeral 33 designates a printed circuit board, which is arranged above the yaw 30, on which six coils of bearings are arranged surrounding the through hole 33a into which the holder 31 fits, and ~L6 is provided. When a current is passed through these coils 1 to L6, a magnetic flux is generated, and the rotor 27 is rotated in cooperation with the permanent magnets 28 and 29 of the rotor 27.

A disk 34 is fixed to the lower side of the rotor 27, as shown in FIGS. 3 and 4. A pattern 35 in which a total of six black and white zones are alternately arranged at equal angular intervals and a pattern 36 in which a total of 102 black and white zones are formed are concentrically formed on the lower surface of the disk 34.

The printed circuit board 33 corresponds to these patterns 35 and 36.
Photodetectors 37, 38 are fixed on top.

The photodetector 37 detects the pattern 36 and detects the rotor 27.
Detects the rotation speed. In addition, the photodetector 38 is connected to the coil L
+ ”= Detect the positional relationship between L- and the permanent magnets 28 and 29.

A detection circuit using these photodetectors and coils L and -L is shown in FIG. In FIG. 5, LEDs 2 and Tr6 constitute a photodetector 38, and LED2 and Tr6 constitute a photodetector 37.

In FIG. 5, the rotation start signal NOT (IN
is input to the servo circuit ICz, IC starts operating and the transistors Tr, , Trs, or Tr
z.

Turn on either one between Tra and coil L+, L3゜L
5 or Lx, L4. A current flows through L, and the magnetic field from the permanent magnets 28 and 29 forms a magnetic circuit passing through the yoke 30, so that repulsion and attraction alternately occur between the magnetic flux generated by the coil and the rotor. 27 begins to rotate.

This rotation is detected by said photodetector 37,38.

Now, when the black color of the pattern 35 is detected by the photodetector 38 consisting of LED and Trs, the output of Tr5 flows to IC,, IC, and is manually applied to the base of Tr.
r+ is conductive and current is supplied to coils L+, Ls, and Ls. Also, when white is detected, the output of Trs is
, is turned on, current flows through Tr, and coil L2. L4
．． A current flows through L. At this time, since IC2 is an inverter, the output is 0, Tr+ is turned off, and no current flows. As a result, coil L1. L3.
No current flows through Ls.

That is, by changing the information between LED and Tra,
+ and Tr2 are alternately switched to cause current to alternately flow through odd-numbered coils and even-numbered coils.

By the way, since the rotor 27 needs to maintain a certain rotation speed, Tr+ and Trx are turned on and off.
The Tri is used as a digital switch, and the Tri is used as an analog switch to control the current flowing through the coil and rotate the rotor 27, which has a built-in permanent magnet.

A servo IC is used to rotate the motor 7 at a constant speed,
A CR component such as a crystal oscillator is used as a part of the servo IC to oscillate a reference frequency with accurate pulse time intervals, and this is manually input to the servo IC 3 and an LED,
The rotational frequency, which is the detection result of the pattern 36 by the photodetector 37 consisting of the IC and Tra, is input to the IC, and the mutual frequencies are compared. If the rotational frequency generated by rotation of the pattern 36 is below the reference frequency, a high current is applied to the base of Trs to coil it, and a large current is supplied to ~L6 to increase the rotational speed. Further, if the rotational frequency is equal to or higher than the reference frequency, a low current is supplied to the base of Trs, and a small current is supplied to the coils L, -L, to lower the rotational speed.

In this way, the rotational speed of the rotor 27 is detected by the photodetector 37 and the pattern 36, and the servo C3 compares it with the reference frequency to fit the base current of the Trs to a constant speed. There is.

By the way, specifically, the rotational speed of the rotor 27 during steady state is one rotation at 204 n5ec, and the number of passes of the pattern 35 to the photodetector 38 during one rotation of the rotor 27 is 6.
Therefore, the switching period of Tr+ and Tra is 204/6, which is 34 m5ec. Also, the standard pulse time interval for rotating the motor at a constant speed is 2III.
The base of the drive transistor 23 is controlled at intervals of sec. Therefore, pattern 36 is divided into 102 equal parts.
Since the load fluctuation is relatively small when the magnetic head is in contact with the floppy disk for recording and reproducing data, the standard pulse time interval can be expanded to 2 m5ec or more and the rotation is sufficiently satisfactory. can be obtained. Rather, what is difficult is the precision of dividing the pattern 36, the precision of the signal rise time of the photodetector 37, etc., and if these precisions can be improved, there is no problem even if the reference frequency is lowered.

By the way, the permanent magnets 28 and 29 housed in the rotor 27
If it is formed from an integrally molded ring-shaped permanent magnet, the boundary surface of the magnetic poles becomes unclear when magnetized. Therefore, in this example, a split type is used, thereby reducing the mass of the entire permanent magnet and reducing the distance between the magnetic poles. This creates a space between the parts and reduces the weight.

Also, if you adopt this kind of rotor structure.

In order to downsize motors in the future, it is highly conceivable that permanent magnet materials will be made of expensive rare earth materials, so the use of split permanent magnets will lead to resource savings and cost reductions.

Incidentally, a large-diameter gear 39 and a cam 40 are rotatably supported on the output shaft 8 of the motor 7 via a bearing 41, and the gear 39 meshes with the pinion gear 19, so that the rotation of the pulse motor 16 is controlled. communicated. When a single pulse is applied to the pulse motor 16, the gear 17 attached to its output shaft 8 rotates 18 degrees. This rotation is transmitted to gear 39 via gear 18 and pinion gear 19.

By the way, high precision is required for the dimensional accuracy of the relative positional relationship between the magnetic head 4 on the carriage IT and the output shaft 8 of the motor 7.

The reason for this is that if the dimensional accuracy varies, compatibility between cassettes will be lost, and recording and playback will become impossible if other cassettes are used.

Therefore, in order to reduce variations in dimensional accuracy between the magnetic head 14 and the output shaft 8, a cam 4 for driving the carriage is attached to the output shaft 8, which is the rotation center of the floppy disk.
It is optimal to attach 0.

In addition, by attaching the cam 40 to the output shaft 8 via a bearing 41 with excellent rotational efficiency, the cam can be connected to the motor 7.
This reduces the impact on the engine and reduces the rotational load.

By the way, as will be described later, since the cam 40 is engaged with the roller 15 provided on the carriage, the vibration of the output shaft 8 is transmitted to the cam 40, the carriage 11 vibrates, and the vibration is transmitted to the magnetic head 14. . However, since the floppy disk is also attached to the output shaft 8, the vibration of the magnetic head and the vibration of the floppy disk are synchronized, and the track position and dimensions do not go out of order.

Incidentally, in reality, when the pulse motor 16 is energized with three pulses, the angle of the cam 40 changes by 9 degrees, and the carriage 11 is set to move by one track.

However, as shown in Fig. 7, the characteristics of a pulse motor are that when one pulse of electricity is applied, the axis of the pulse motor 16 is displaced by 18 degrees, but when the second pulse is applied, it should be displaced by 36 degrees, but due to the inertia of the rotor. And due to magnetization accuracy, 61 rotations are exceeded. When the third pulse is applied, 5
The amount of δ2 displacement decreases even though it is scheduled to be displaced by 4 degrees. Furthermore, when the fourth energization is applied, the rotation stop position of the pulse motor generally varies slightly, such as rotating 72 degrees as planned.

Therefore, if the cam 40 rotated by the pulse motor 16 has a linear relationship between the rotation angle and the amount of displacement as shown in FIG. 8, then a pulse motor with the characteristics shown in FIG. 7 can be used. In this case, the stop position of the carriage 11 varies at a rate of ±δ2154°, making it impossible to accurately stop the magnetic head on a predetermined track.

On the other hand, if a cam in which the relationship between rotation angle and displacement changes stepwise as shown in Fig. 9 is used, even if the stop position of the pulse motor is off by 52 minutes, the cam will not be displaced to the same extent.
Variations in stopping positions can be drastically reduced. Also,
Even if backlash or eccentricity occurs between the power transmission gears, the errors caused by these can be absorbed, and the magnetic head can be accurately aligned with the desired position. As a result, backlash can be provided between the gears in the rotational torque of the pulse motor, so it is possible to reduce the rotational torque and power consumption.

For this reason, in the present invention, a plurality of stepped cam surfaces 40a are formed on the circumferential surface of the cam 40, as shown in FIG. The number of these stepped cam surfaces 40a is 40, which in this embodiment is the same as the number of tracks on a floppy disk. Further, the circumferential surface of the cam 40 is on a spiral curve, and gradually becomes smaller from the short diameter part to the long diameter part, and the connecting part between the short diameter part and the long diameter part is a straight part 40b, and the base of this straight part 40b is An arcuate recess 40c is formed.

By the way, if it is not always known which track position the magnetic head 14 currently corresponds to, recording and reproducing errors will occur. Therefore, when the magnetic head is located at a position corresponding to the maximum diameter track of the floppy disk, a reference signal is generated from the device side, and the correspondence state with other track positions is indicated by the number of pulses energized to the pulse motor 16. We devised a configuration in which the position of the magnetic head is determined by memorizing it using a control circuit that does not have a built-in control circuit. This is the disk 42 that constitutes the detection mechanism section 2.

As shown in FIGS. 1 and 23, the disc 42 is attached to the gear 39 in a state in which it is rotatably fitted to the boss 43. A detection piece 42a protrudes from a part of the disc 42. This is a structure that reflects light by pasting plating or aluminum foil. This detection piece 4
2a is detected by a photodetector 25 provided on the lower surface of the printed circuit board 20, and a pulse signal is transmitted once per rotation. Therefore, if this detection piece 42a is arranged so that it is detected by the photodetector 25 when the magnetic head 14 is at the maximum diameter track position, the position can be detected.

Of course, it is possible to provide a detection piece directly on the magnetic head 14 so that the position of the magnetic head can be known, but in this embodiment, the l-track movement distance is 0.125 mm, and the electrical output of the photodetector is Since the changes are minute, expensive circuitry is required and it is not practical.

However, in the present invention, the detection piece 42a rotates slowly together with the gear 39, and the amount of movement per track is approximately 2.
．． 5 mm, it became possible to detect the track position, that is, the head position using the inexpensive photodetector 25.

On the other hand, although it is mounted on the gear 39 together with the cam 40 and the disc 42, positional deviations may occur due to processing errors or mounting errors, and the above-mentioned detection function may not be fully exerted. For this reason, in the present invention, arc-shaped long holes 42b are provided in the disc 42 facing each other, and screws 44 that are screwed onto the gear 39 are fitted into these long holes 42b, so that the disc 40 can be rotated. In this way, the position of the detection piece 42a can be finely adjusted. To perform this fine adjustment, an eccentric bin gauge 101 as shown in FIG. 23 is used. This eccentric bin gauge 101 has an eccentric bin 101a at the lower end. If the diameter of this eccentric bottle gauge 101 is D, and the width of the radial elongated hole 42c formed in the disk 42 is W, then D=W, and the elongated hole 39 into which the eccentric bottle 101a fits.
A is formed on the gear 39 side facing the elongated hole 42c.

Therefore, eccentric bin gauge 1. OL is fitted into the elongated hole 4.2c, the eccentric bottle l01a is fitted into the small hole 39a, and the eccentric bottle gauge lot is rotated.

The disc 42 can be rotated left and right, and the detection piece 42a
This allows for fine adjustment of the position.

In the present invention, the tracks of the floppy disk are divided into 40 equal parts with a radius of 151IIIT+ to 201 to form one track O, 125++u++. Therefore, the magnetic head is 15m+ to 20m centered around the output shaft 8 of the motor 7.
If the distance between m is not driven accurately at a pitch of 0.125 mm,
You will no longer be able to use floppy disks recorded on other devices.

Further, if the maximum track diameter position 20m5+ and the minimum track diameter position 151tlII+ of the magnetic head are not accurate, the specifications will not be common to other devices. Therefore, the dimensional tolerance of each component between the output shaft 8 and the magnetic head 14 cannot be ignored.

This problem is solved by the mounting structure of the roller 15. The mounting structure of the roller 15 is shown in FIGS. 11 to 13. That is, the roller 15 is
It is mounted eccentrically via the shaft 15a. This amount of eccentricity is δ. The screw shaft 45 has a groove 45a at its upper end.
A screwdriver or the like is inserted into the carriage 11 and screwed into a screw hole 11a formed in the carriage 11.

Therefore, when the screw shaft 45 is rotated, the center of the roller 15 can be rotated with a radius δ, and the distance between the roller 15 and the cam 40 is determined by the distance between the output shaft 8 to which the cam 40 is fixed and the magnetic head 14.
You can reliably fine-tune the distance between. After finishing the fine adjustment, a lock nut 46 is screwed onto the upper end of the screw shaft 45 to fix it in that position. In this way, variations in processing accuracy and installation accuracy are absorbed and adjusted.

As shown in FIG. 1O, the cam 40 has a plurality of through holes 40e formed around a central hole 40d into which the output shaft 8 is fitted, and a shaft 43a protruding from the boss 43 in these through holes 40e. are mated together and fixed using a method such as kashinuru.

A disk 47 is attached to the upper end of the output shaft 8.

The disk 47 has a boss 48 on the top surface and a cylinder 49 on the bottom surface.
This cylinder 49 is fitted onto the upper end of the output shaft 8, and fixed by screwing the screw 50 from the side.

This cylinder 49 has a central hole 51 , which has a disk 51 between the disk 47 and the cam 40 . a, and is fixed by caulking the bottle 51c. The disc 51 has a detection piece 51b protruding from its circumferential surface, and the detection piece 51b is formed as a reflector so that it can be detected by another photodetector 26 provided on the top surface of the printed circuit board 20. ing.

An arcuate spring piece 52 is punched out in a part of this disk 51, and a bottle 53 is formed on the upper surface of the free end side.
is installed protrudingly. The bottle 53 is fitted into a through hole 47a formed in a part of the disk 47 and faces above the disk 47.

This bottle 53 is fitted into a through hole formed in the hub of a floppy disk housed in a cassette, which will be described later, and transmits the rotation of the output shaft 8. This disc 51 is connected to the cam 40.
It is also fixed to the boss 43.

A detection piece 51b protruding from the disc 51 is detected by the photodetector 26 every rotation of the output shaft 8 and generates a start position signal.

On the other hand, the holder portion 3 has a structure as shown exploded in FIG.

That is, the holder portion 3 is assembled based on the substrate 54.

The substrate 54 is press-molded from a metal plate, and side plates 55 are formed on both left and right sides thereof. These side plates 55
Through-holes 55a are formed at opposing positions on the distal end side, and a shaft 56 is fitted into these through-holes. Both ends of the shaft 56 are rotatably fitted into through holes 6a formed in the left and right side plates of the base 6.

Further, a projecting piece 57 is provided in the center of the side plate 55,
A spring 58 is stretched between the protruding piece 57 and a protruding piece 6b protruding from the base 6, and applies a force to draw the board 54 toward the base 6.

A through hole 54a into which the disk 47 can be inserted is formed in the center of the substrate 54, and an elongated hole 54b into which a magnetic head can be inserted is formed on the side of the hole 54a.

Bent pieces 54c, 54c bent upward are formed on the free end side edge of the substrate 54, and bent pieces 55b are formed on the edge of the side plate 55 in a state of expanding left and right. A bent piece 55c bent downward is formed on the lower side of the bent piece 55b.

These bent pieces 54c, 55b, and 55c serve as guides when the cassette 5 is installed.

Further, guide pieces 55d for guiding the cassette 5 are formed at the lower ends of the side plates 55, respectively.

Levers 59 and 60 are attached to the outside of the left and right side plates 55. These levers 59 and 60 have through holes 59a and 60a formed in their central portions along the longitudinal direction, and guide pins 6 fixed to the protruding piece 57 are provided in these through holes.
1 are fitted respectively. Each lever 59.60
A protruding piece 59b is provided at the tip of the protruding piece 59b to protrude downward.

A spring 62 is stretched between 60b and the protruding piece 57, and constantly pulls the respective levers 59 and 60 toward the front side.

Notches 59c and 60c are formed along the longitudinal direction on the front edge of each lever 59, 60, and a guide pin 63 fixed to the side plate 55 is fitted into these notches. .

Further, the levers 59 and 60 have L-shaped bent portions 59d and 60d bent at right angles toward the board 54 at their tip ends.
These bent portions 59d and 60d fit into a notch 55e formed on the upper surface of the tip of the side plate 55, so that the tip faces the inside of the side plate 55, and the cassette 5 is mounted. Both sides 5a and 5d of the tip of the cassette 5 when
engaged with.

Furthermore, a projecting piece 59e is provided on the front edge of each lever 59,60.
, 60e are provided protrudingly, and these protrusions 59e, 60e
is located at a position where it can engage with one guide rail lO provided on the base 6 side.

Also, between the protrusions 59b and 59e of each lever 59 and 60b
, 60e are guide portions 59f, 60f that contact guide rollers of an operating lever, which will be described later.

By the way, the tip of the board 54 has a protrusion 6 approximately in the center thereof.
4 is provided protrudingly, and a lever 66 is rotatably supported at the center portion of the lever 66 via a pin 65 at the distal end thereof.

This lever 66 is formed almost in the shape of a "<" character,
A bent portion 59 is formed at the tip of the lever 59 at one end.
A bottle 67 is slidably fitted into the elongated hole 59g formed at d and projects downward.

Further, a protrusion 68 protruding from the upper surface of the other end of the lever 66 engages with a pad arm to be described later.

On the other hand, the disc holding mechanism portion 4 is constructed as shown in FIG.

The disc holding mechanism 4 is composed of a leaf spring 69 and a pad arm 70. The leaf spring 69 is formed into a substantially quadrilateral shape, and a boss 71a of a rotating body 71 is fitted from the lower side of the leaf spring 69 into a through hole 69a formed in the center thereof. Presser ring 72 located at
An arcuate portion 71b is formed on the circumferential surface of a six-rotator 71 that is fitted into a through hole 72a, integrated with the presser ring 72 by a screw 73, and rotatably attached to the handling spring 69. This part fits into the through hole 54a of the substrate 54 of the holder, ensuring smooth insertion when the cassette 5 is mounted. This rotating body 71 comes into contact with the hub of a floppy disk housed in a cassette, which will be described later.
It plays the role of supporting the rotation of the floppy disk from above.

The leaf spring 69 has three through holes 69b formed therein.
A bottle 74 protruding from the upper surface of the substrate 54 is fitted into these through holes 69b and fixed by threading.

A spring piece 75 is protruded from the center of the tip of the leaf spring 69, and this spring piece 75 is fitted into the notch 54d formed in the base plate 54, and serves to hold down the cassette 5.

Further, spring pieces 76 are attached to both left and right ends of the other end of the leaf spring 69.
．． 76 is formed and serves to press down the cassette 5 from above.

The plurality of punched grooves formed across the through-hole 69a provide elasticity to the portion surrounding the through-hole 69a, and serve to elastically maintain contact between the rotating body 71 and the hub of the floppy disk. It is something.

The pad arm 70 has a pad 77 on the lower surface of its tip, and a leaf spring 78 is connected to its base end.
A pad arm 77 fixed to a protrusion 11a protruding from one end of the pad arm 7 corresponds to the magnetic head 14.
A recess 70a is formed on the lower surface of o at a position that can correspond to the protrusion 68 of the lever 66 provided on the board 54 side. The magnetic head 14 is inserted into the elongated hole 54b of the base plate 54, and is placed facing the magnetic head 14, and presses the floppy disk from above.

On the other hand, the cassette 5 has a structure as shown exploded in FIG. 14.

That is, the cassette 5 has cassette halves 81 and 82 molded from synthetic resin or the like, and a through hole 8 into which the disc 47 and the rotating body 71 are inserted is formed at opposing positions in the center of the cassette half.
1a and 82a are formed, and openings 81b and 82b into which the magnetic head and pads are inserted are formed in the vicinity thereof. Inside the upper cassette half 81, a disc-shaped liner 83 is fixed at a plurality of locations indicated by reference numeral 83a via an adhesive or the like. This liner 83
has a through hole 83b at a position opposite to the through hole 81a of the cassette half 81, and an opening 83c at a position opposite to the opening 81b.

Spring pieces 84 and 85 are arranged between the liner 83 and the cassette half 81 with an opening 83c in between. The base ends 84a, 85a of the spring pieces 84, 85 are fixed to the lower surface of the cassette half 81, and their free ends press the liner 83 downward on both sides of the opening 83c. The role of these spring pieces 84, 85 is to press the liner 83 against the floppy disk on both sides of the magnetic head and pads that sandwich the floppy disk from above and below, thereby maintaining reliable contact between the floppy disk and the magnetic head.

This state is shown in FIG.

A liner 86.86 is provided on the lower cassette half 82 side with a through hole 82a in between, and a small hole 82c is formed at a position that does not come into contact with the floppy disk. A bottle 21 protruding from the base 6 side is provided in this small hole 82c.
A floppy disk 87 is accommodated between the lower cassette half 82 and the 6 liner 83 whose upper end is fitted to form a positioning hole when the cassette is installed. The floppy disk 87 has a hub 88 in the center, and the center hole 88
The post 48 of the disk 47 is fitted into the hole 88b, and the pin 53 protruding from the spring piece 52 of the disk 51 is fitted into the through hole 88b formed in the vicinity of the post 48 of the disk 47.

Incidentally, the base 6 side is devised to constitute a mounting reference surface when a cassette is mounted. That is, as shown in FIG. 16, the bin 21 protruding from the base 6 not only serves to number the printed circuit board 20, but also has a protrusion 21b protruding from its upper edge 21a that serves as a small hole in the cassette half 82. The upper edges 89a, 90 of the support columns 89.90 are fitted into the support 82c for positioning, and are integral with or separate from the side wall of the base 6.
0a is set to be in the same plane as the upper edge 21a of the bottle 21, thereby forming a mounting reference plane. The bottle 21 and the supports 89, 90 are arranged to form the vertices of a triangle, and the outside (l!
Projecting pieces 89b and 90b are provided on the outer edge 5c of the cassette 5.

It plays the role of positioning 5d.

Therefore, when the cassette 5 is lowered together with the holder toward the base 6 by the operation described later, the cassette 5 is reliably supported on a certain reference plane by the bin 21 and the pillars 89 and 90, and is also supported by the protrusion 21b and the protrusion 21b. Accurate positioning is achieved by the pieces 89b and 90b.

By the way, an operating lever 9J is provided on the base 6 side. The operating lever 91 is formed into a substantially U-shaped frame and is rotatably supported on both sides of the front end of the base 6 via pins 92. A roller 93 is rotatably attached to the inner surface of the bin 92 at a position remote from the bin 92.

This roller 93 is the guide portion 59 of the lever 59,60.
f, located in contact with 60f.

This operating lever 91 is given the habit of rotating clockwise in FIG. 1 about the bottle 92 due to its own weight.

Next, the operating method and operation of the floppy disk device according to the present invention constructed as above will be explained.

Before the cassette 5 is installed inside the holder, the base plate 54 is in a state where the front end is lifted upward as shown in FIG.
It is in a state where it is pulled toward this side by the tensile force of 2. However, the lower ends of the protrusions 59e and 60e of the levers 59 and 60 are in contact with the guide rail JO, and do not fall down even when the tensile force of the spring 58 is applied, but maintain this state.

At this time, the operating lever 91 is rotated to the front side, and the roller 93
are in contact with the front corners of the guide portions 59f and 60f.

In this state, the lever 66 is rotated in the counterclockwise direction in FIG.
As shown in the figure, the bad arm 70 is in contact with the rear side of the recess 70a on the lower surface of the bad arm 70, and the bad arm 70 is connected to the handling spring 78.
The pad 77 is pushed up in a direction away from the substrate 54 against the pressing force.

In this state, when the cassette 5 is inserted into the guide section formed by the bent pieces 54c, 55b, and 55c at the front end of the board 54, the tip g5a of the cassette 5 is inserted.

5b is the bent piece 59d on the back side of the lever 59.60.

60d and when the cassette 5 is further pushed in, the levers 59 and 60 move inward against the tension of the spring 62. This limit of movement is regulated by long holes 59a and 60a. Eventually, as levers 59 and 60 move forward, the 18th
As shown in the figure, the projecting pieces 59e and 60e are attached to the guide rail lO
start to move away from

At the same time, as the lever 59 moves forward, the lever 66 is rotated clockwise in FIG. 2 via the pin 67, and as shown in FIG.
It starts to fit inside.

As a result, the tip of the bad arm 70 is lowered by the force of the leaf spring 78, passes through the elongated hole 54b of the board 54, fits into the opening 81b of the cassette 5, and the floppy disk 87 is inserted into the opening 81b of the cassette 5.
start contacting.

Eventually, when the levers 59 and 60 are pushed to the farthest position, the protrusions 59 of each lever are pushed in as shown in FIG.
e, 60e is separated from the guide rail lO, and the spring 5
The holder part 3 centered on the substrate 54 is pulled downward by the tensile force of 8.

At this time, the projection 21b of the bottle 21 is fitted into the small hole 82c formed on the back surface of the front end of the cassette 5, and the lower surface of the cassette 5 are in contact with each other, and the cassette 5 is set on the reference surface. At the same time, both ends 5c and 5d on the back side of the cassette 5 are positioned and mounted in the left-right direction by the projections 89b and 90b of the support 89.90.

In this state, as shown in FIG. 15, the floppy disk 87 is sandwiched between the pad 7γ and the magnetic head 14 from above and below, and both sides of the floppy disk 87 are pushed through the liner 83 which is pressed by the spring pieces 84 and 85. The floppy disk 87 is in a slightly curved state with the floppy disk 87 sandwiched therebetween, and is securely in contact with the magnetic head I4.

Magnetic recording and reproduction is performed in this state.

If you wish to remove the cassette 5, press the operating lever 91 downwards from the fully installed state shown in FIG. 60 is pushed upward and pulled back toward the user by the force of the spring 62. Eventually, the protrusions 59e and 60 of each lever
The lower end of e is separated from the guide rail 10, and the entire holder part is locked with the front side raised.

At the same time, by moving the levers 59, 60 toward the front, the bad arm 70 is also raised, and the cassette 5 is pushed back toward the front by a predetermined distance. When the cassette 5 is picked up and pulled out, the spring 75 of the leaf spring piece 69 restrains the cassette 5.
Since it is only 76, it can be easily drawn out.

As is clear from the above description, according to the present invention, by arranging the head feeding cam coaxially with the spindle shaft that rotates the magnetic disk, the mechanism is simplified and the head carriage is moved over the entire range of movement of the head. The head feeding cam, which is a relatively large component for moving the magnetic disk, can be placed near the center of rotation of the magnetic disk to improve space efficiency, which is extremely effective in downsizing the device.

In addition, by arranging the head feeding cam coaxially with the magnetic disk drive spindle, each fulcrum can be concentrated in one place, which reduces errors caused by positional deviation. The provided head position adjustment means also has the effect of increasing head position accuracy.

In addition, in the above embodiment, the peripheral surface of the head feeding cam that engages with the head carriage has a continuous surface with the same number of steps as the number of tracks on the magnetic disk, so the track position can be accurately determined. It can be detected as well as
This has an excellent effect in that accurate tracking can be performed without being influenced by the characteristics of the pulse motor.

[Brief explanation of the drawing]

The figures are for explaining one embodiment of the present invention; FIG. 1 is an exploded perspective view of the base portion, FIG. 2 is an exploded perspective view of the holder portion,
Figure 3 is an exploded perspective view of the motor, Figure 4 is a perspective view of the rotor seen from below, Figure 5 is a circuit diagram showing the connection between the photodetector and the coil, and Figure 6 is the base section. A side view, FIG. 7 is a diagram showing the relationship between the number of input pulses and the rotation angle of a pulse motor, and FIG. 8 is a diagram showing the relationship between the rotation angle and displacement amount of a general cam shown as a comparative example. FIG. 9 is a diagram showing the relationship between the rotation angle and displacement amount of the cam applied to the present invention.
The figure is a plan view of the cam, Figure 11 is an exploded perspective view showing the installation structure of the roller that the cam contacts, Figure 12 is a perspective view of the roller seen from below, and Figure 13 is the arrangement of the cam and roller. A side view showing the state, FIG. 14 is an exploded perspective view of the cassette, and FIG.
Figure 5 is a partially enlarged longitudinal sectional side view of the cassette, Figure 16 is a perspective view showing the reference plane setting structure for mounting the cassette, Figures 17 to 19 are side views explaining the operation, and Figure 20 is the cassette. 21 and 2 are partial longitudinal side views showing the installed state of the
FIG. 2 is a side view illustrating the operation of the bad arm, and FIG. 23 is a perspective view illustrating a fine adjustment method using an eccentric bin gauge. l-...Base part 2...Position detection mechanism part 3-
・-Holder part 4...-Disk holding mechanism 5...
-Cassette 6...-Base 7...-Motor
8...Output shaft 9.10-...Guide rail 11...Carriage 14...-Magnetic head 15-
...Roller 16...-Pulse motor 20...
Printed circuit board 25.26-Photodetector 21...-Bin
27...-rotor 28.29... permanent magnet
34...-Disc 40...-Cam 47...Disk 54...Base board 59.60.66...Lever 69...Handling spring 70...Pad arm 77...-Bud 81.82- -Cassette half 83.86...liner 87-floppy disk 88--hub 89.90...post 91-
・-Operation lever-5:- Fig. 20 Fig. 21 Fig. 22 Fig. 23

Claims (1)

[Scope of Claims] A rotary drive shaft that rotates a mounted recording medium, a head carriage on which a head for recording or reproducing data on a plurality of tracks on the recording medium is mounted, and the head carriage is rotated by the head carriage. A guide member that guides in a predetermined direction along the recording surface of the recording medium, and a guide member arranged to rotate coaxially with the rotational drive shaft, move the head carriage along the guide member, and move each head carriage on the recording medium in a predetermined direction. A cam for positioning the head onto a recording track; and a head position adjustment means disposed on the head carriage and adjusting the position of the head with respect to a recording track on the recording medium regulated by the cam. A recording or reproducing device characterized by: