JPS60182071A - Magnetic disc device - Google Patents

Abstract

PURPOSE:To attain accurate track positioning without using an expensive component such as a stepping motor by providing a detecting means to detect the vertical movement of stopper of a cam member for moving a carriage. CONSTITUTION:When gears 22a and 34 mesh with each other by a switching lever 16, a cam disc 17 is rotated in the direction L direction and the carriage 25 is moved in the arrow H direction. The stopper 35 being a spring member for positioning and counting is arranged under the cam disc 17 and a head 35a is in a groove 24, then the carriage 25 is supported at a prescribed position. The cam disc 17 is rotated and the stopper 35 is depressed down, then a lower end 35b shuts a slit part 36a of a photo sensor 36 for track counting under the circuit board 2a, and the photo sensor 36 is turned off. The carriage 25 is moved by one track to a signal from the host side, and the sensor 36 repeats on/off by the moving track's share so as to count the track number.

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 using a flexible magnetic disk.

[Prior Art] A conventional magnetic disk device of this type is roughly divided into a magnetic disk clamp mechanism 9, a concave rotation mechanism, a magnetic head seek mechanism, a magnetic head, and a control circuit. There is.

Among these, a spindle motor is mainly used in the magnetic disk rotation mechanism, and the magnetic disk clamped by the spindle and center cone is rotated by rotating the spindle directly or via a belt.

A stepping motor is connected to the seek mechanism of the magnetic head, and the movement, stopping, or positioning of the magnetic head is performed by the stepping motor via a steel belt, screw shaft, cam, or the like.

The magnetic head is moved by converting the rotation of the stepping motor into linear motion.

The rotation direction of the stepping motor is determined by a signal from the control circuit.1. Since the magnetic head is rotated by an amount corresponding to the number of pulse signals, the moving direction and moving distance of the magnetic head are determined by these signals.

In addition, magnetic stop 1 positioning is performed by energizing the stepping motor and electrically holding it. Therefore, positioning accuracy mainly depends on the accuracy of the rotation angle of the stepping motor.

By the way, using separate motors for the magnetic disk rotation mechanism and the magnetic head seek mechanism as described above not only increases costs, but also limits the ability to make the device more compact and cost-effective.

Furthermore, even when the magnetic head is in a stopped state, the stepping motor remains energized, resulting in wasteful power consumption and generation of heat.

[Objective] The present invention was made to eliminate the above-mentioned conventional drawbacks, and it is possible to perform accurate track positioning without using expensive parts such as stepping motors.
Furthermore, the object is to provide a magnetic disk device with low power consumption.

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

FIG. 1 and the following illustrate one embodiment of the present invention. A magnetic disk drive 1 according to the present invention is equipped with a spindle motor 2. As shown in FIG.

The spindle motor 2 has a circuit board 2a as shown in FIGS. 11 to 13, and a spindle 9 and a gear 34 integrated therewith are rotatably supported on the circuit board 2a.

As shown in FIG. 13, the circuit board 2a has a structure in which a silicon steel plate 2b is laminated with a rolled steel plate 2C.
A circuit pattern is formed on the side surface indicated by arrow A, and various electronic components are attached. This silicon steel plate 2b also serves as a shield plate.

A camshaft 15 and a positioning pin 40 are mounted on the rolled steel plate 2C.
are provided protrudingly, and phototransistors 37a and 38 for detecting write protect signals and index signals are provided.
A is provided.

Further, various mechanical parts are attached to the side surface of the rolled steel plate 2C shown by arrow B.

This circuit board 2a also serves as a board for the magnetic disk device 1.

A front panel 3 is attached to the tip of the circuit board 2a, and as shown in FIG. 2, this panel 3 has an opening 3a (not shown) for inserting a magnetic disk.

As shown in FIG. 1, side plates 4 and 5 are attached to the left and right sides of the circuit board 2a to serve as guides when inserting the magnetic disk.
Guide grooves 4a and 5a are formed respectively.

A board 6 constituting a magnetic disk clamping mechanism is attached to the upper portions of the side plates 4 and 5.

One end of an arm 8 is attached to the base plate 6 via a leaf spring 7 at a position closer to the side plate 4, and a center cone 10 is provided at the tip of the arm 8 at a position facing the spindle 9. There is.

Further, a light emitting diode 38 for index detection is provided on the arm 8 at a position facing the phototransistor 38a.

Further, a bearing 11- is provided on the substrate 6 at a position closer to the front panel 3 side and closer to the side plate 4 side, and a shaft 12 is rotatably supported on this bearing 11-. axis 12
A cam 13 is provided at the tip, and a lever 14 is fixed to the other end on the outside of the front panel 3.

The cam 13 and the arm 8 are always in contact, and the arm 8 follows the movement of the cam 13.

The cam 13 is operated by operating the lever 8-14.

Further, a light emitting diode 37 for detecting a write protect signal is attached to the substrate 6 at a position facing the phototransistor 37a.

On the other hand, the one indicated by the reference numeral 16 is a switching lever shown in Fig. 8 (a).
) to (C), it has a Y-shape, and its base ends are connected to a pair of solenoids 18 and 1 fixed on the circuit board 2a.
It is rotatably connected to a common plunger 19 of 8a by a pin 20.

Bifurcated arms 16a and 16b of the switching lever 16
(7) A gear 22 is rotatably supported at the tip of one arm 16a via @h21.

Further, a shaft 21a is provided at the tip of the other arm 16b.

Gears 22a and 22b are rotatably supported via 21b.

Gears 22a and 22b are always in mesh.

On the other hand, the circuit operator (board 2 a Jz has the switching lever 16
The cam disk 17 is on the upper side! I! 1I115.

A gear 17a is formed on the outer peripheral surface of the cam disk 17, and a spiral groove 23 having a V-shaped cross section is formed on the surface thereof, as shown in FIG. 5(a).

Now, in Fig. m5 (a), if the minimum radius of the spiral groove +3 is rov, and the angle from the position of a certain radius r to the starting end of the groove is α, then r=K・lX+ as shown in Fig. 5 (C).
The spiral groove 23 is formed so as to be ro.

Further, FIG. 5(b) shows the back surface of the cam disk 17, and a groove 24 is formed near the periphery at a constant angle θ (0=360°/n,
Grooves 24 having a V-shaped cross section are formed at equal intervals at angles (n is an integer).

Note that the constants in FIG. 5(C) are determined by the trunk density of the device and the pitch 0 of the grooves 24.

Gear 17aIi of cam disc 17: Fig. 8(a)-(
As shown in C), it meshes with the gears 22 and 22b, and! , 7J exchange/<-16, the bases of the arms 16a, 16b are rotatably supported on the shaft 15.

On the other hand, a carriage 25 is arranged above the cam disk 17 and is slidably guided by a guide bar 26.27. It is fixed at °29.

Although not shown, several magnetic heads are mounted on the carriage 25.

As shown in an enlarged view in FIG. 7, a through hole 25a is vertically formed in the lower surface of the gear ridge 25, and a steel ball 3o is rotatably fitted into the hole 25a.

This steel ball 30 is always held at P by a spring member 31 provided on the second side of the carriage 25.

It is pressed against the spiral groove 23 with no play due to the pressing force.

The gap 12 between the cam disk 17 and the carriage 25 is the distance f? between the cam disk 17 and the center of the steel ball 3o? +l
It is set to be smaller than l j2 + at any position.

Therefore, when the cam disk 17 rotates in the direction of arrow E, the carriage 25 moves in the direction of arrow F, and when it rotates in the direction of G, the carriage 25 moves in the direction of arrow H.

The plunger 19 of the solenoid is provided with a return spring 33.33a on the side of each solenoid 18.18a, and the plunger 19 is in an intermediate position when both solenoids 18.18a are not energized.

On the other hand, a gear 34 is fixed coaxially to the lower part of the spindle 9, and this gear 34 is located in the same plane as the cam disk 17, as shown in FIG.

Further, when power is supplied to the device and the spindle motor 2 rotates, the spindle 9 and the gear 34 are activated as shown in FIGS. 8(a) to (C).
It is rotated in the direction of the arrow ■ as shown in . When both the solenoids 18 and 18a are not energized, the gear 34 and the gear 22.degree. 22a are not engaged with each other as shown in FIG. 8(a), and the cam disk 17 is stopped.

In this state, the magnetic disk is attached and ready for recording and playback.

On the other hand, as shown in FIG. 8(b), one solenoid 1
8 is excited, the plunger 19 is attracted to the solenoid 18 side, the switching lever 16 is rotated counterclockwise in the figure, the gear 22 and the gear 34 are engaged, the cam disk 17 is rotated in the direction of arrow J, and the carriage 25 is rotated. Move in the direction of arrow F in FIG.

When the other solenoid 18a is energized, the state shown in FIG. 8 (
As shown in C), the gear 22a matches the gear 34, and the cam disk 17 rotates in the direction indicated by the arrow in the figure, causing the carrier cage 2 to rotate.
5 moves in the direction of arrow H in FIG.

The switching signal to each solenoid l'8.18a is sent from the control device side.

In the cases shown in FIGS. 8(b) and 8(c), the carrier is in motion and no recording or reproduction is performed on the magnetic disk.

On the other hand, as shown in FIGS. 10(a) and (b), the cam disc 1
A stopper 35, which is a spring member for positioning and counting, is arranged below the stopper 7, and its head 35a is fitted into the groove 24.

The stopper 35 is always pressed against the cam disk 17 by the force P2.

Further, below the circuit board 2a, a photosensor 36 for track counting is provided near the lower end 35b of the stopper 35.

Note that instead of the photosensor 36, a mechanical switching means such as a microswitch may be used.

The head 35a of the store bar 35 is constructed as shown below.
It is possible to hold the carriage 25 in place when it is in the groove 24.

At this time, the cam disk 17 is stopped at the state Fffl shown in FIG. 8(a), and the photosensor 36 is in an on state.

This state is shown in FIG. 10(a).

When a signal is input to the solenoid 18 or 18a in this state, the state shown in FIG. 8(b) occurs.

The state shown in (C) is reached, and the cam disk 17 is rotated to the 10th
As shown in Figure (b), the stopper 35 is pushed down.

As a result, the lower end 35b is connected to the slit g of the photosensor 36.
836a and the photosensor 36 is turned off.

In this way, the solenoids 1B, 1lii are operated according to the number of signals from the control circuit side, and the carrier and the gear 25 are moved accordingly.゛In addition, if the spiral groove 23 is configured so that the cam disk 17 rotates by the pitch θ of the groove 24 (1), and can move the distance equivalent to the rack, then the cam disk 17 rotates by the pitch θ of the groove 24. The carriage 25 moves by one track, and as a result, the photosensor 36 is turned on and off repeatedly for the number of tracks moved, making it possible to count the number of tracks.

Further, the relative position between the magnetic disk and the magnetic head can be adjusted by adjusting the position of the store bar 35.

Incidentally, as shown in FIG. 1, a photosensor 39 for detecting the reference track is provided on the circuit board 2a.

When the magnetic disk is inserted into the opening 3a of the front panel 3 from the direction shown by the arrow C in FIG. It is inserted to the insertion source using 5a as a guide.

In this state, when the lever 14 is rotated in the direction of the arrow in FIG. 2, the cam 13 is rotated and the arm 8 is moved to the spindle 9
Push down to the side.

When the lever 14 is turned 90 degrees and comes to the position shown by the chain line in FIG. 2, the center cone 10 and spindle 9 complete clamping of the magnetic disk via the magnetic disk.

The magnetic disk can be ejected by performing the reverse operation to that described above.

With the magnetic disk mounted in this manner, the carriage is moved as shown in FIGS. 8(b) and 8(c), and recording and reproduction are performed on the target track.

In the above-described embodiments, a gear mechanism which is a rotating body may be used as the power transmission means, or a transmission mechanism using rollers as a rotating body may of course be adopted.

[Effects] As is clear from the above explanation, according to the invention, the lubricant formed on the cam member is driven only when the carriage moves.
・The structure is equipped with a stopper that moves up and down by inserting into and releasing from the rack positioning groove, and has a detection means to detect the downward movement of this stopper, which eliminates the need for expensive parts such as stamping motors. It is possible to provide a low-cost magnetic disk device that can perform accurate track positioning without using the magnetic disk device and consumes less power.

[Brief explanation of drawings]

The figure is for explaining one embodiment of the present invention, and FIG. 1 is a plane [
Threshold, Figure 2 is a front view, Figure 3 is a side view, Figure 4 is a bottom view, Figure 5(a) is a top view of the cam disk, and Figure 5(b) is a bottom view of the cam disk. , Fig. 5(c) is a diagram showing the relationship between the radius and angle of the spiral groove, Fig. 6 is a plan view showing the relationship between the carriage and the cam disk, and Fig. 7 is a partially enlarged view of Fig. 6. 8(a) to 8(c) are explanatory diagrams showing the switching/toward operation, FIG. 9 is a side view of the switching mechanism, and FIG. 10 (
11 is a plan view of the circuit board, FIG. 12 is a side view of the circuit board, and FIG. 13 is a partially enlarged sectional view of the circuit board. DESCRIPTION OF SYMBOLS 1... Magnetic disk device 2... Spindle motor 6... Substrate 8... Arm 9... Spindle 10... Center cone 16.
...Switching lever 17...Cam disc 18.18a.
... Solenoid 19 ... Plunger 25 ... Carriage 30 ... Steel ball Fig. 3 Fig. 4 Fig. 8 (CI) Fig. 8 (C) 1/1σq Fig. 8 (b) 719 Fig. 9 22a 22b 2a

Claims (2)

[Claims] (1) A spindle connected to a drive motor to rotate a magnetic disk, a cam member for moving a carriage rotatably supported near the spindle, and a cam member located between the spindle and the cam member, a switching means for selectively transmitting rotation to the cam member and switching the direction of rotation of the cam member; a stopper that fits into a groove for determining one track position formed on the lower surface of the cam member and moves up and down by being disengaged from the groove; , and detection means for detecting vertical movement of the stopper. (2) The magnetic disk device according to claim 1, wherein the detection means is comprised of a photosensor.