JP2552445B2 - Magnetic disk drive device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive device, which records and reproduces magnetic signals on both front and back surfaces of a magnetic disk. The target is a type that is rotationally driven by a drive pin that engages outside the center of rotation.

[Conventional technology]

In a so-called double-sided type magnetic disk drive device of this type, two magnetic heads are provided facing each other corresponding to both the front and back surfaces of the magnetic disk, as shown in Japanese Patent Publication No. 58-15866. One of these magnetic heads is fixed on a head carriage that moves both heads along the radial direction of the magnetic disk, and the other is supported by the head carriage to facilitate loading of the disk cartridge. Swing arm (head support)
It is fixed to and swings toward and away from the magnetic disk. The swinging arm that supports the movable head on the swinging side is at a standby position which is out of the loading area when the disk cartridge is loaded, and the spring, its own weight,
Arai swings down and swings rapidly due to the urging force of a solenoid, etc., and the movable head presses against the magnetic disk. At this time, the movable head receives an urging force and impacts the magnetic disk so as to strike it.

[Problems to be Solved by the Invention] With respect to the structural form for rotationally driving a magnetic disk, there is a pin drive system mainly adopted in a magnetic disk cartridge having a small disk diameter. For example, as shown in Japanese Utility Model Laid-Open No. 57-102071, a hub for receiving a rotational torque is fixed to the center of a magnetic disk, and the center of the hub is supported by a spindle. The drive pin is engaged with the engaging hole provided in the drive pin so that the drive pin substantially applies the rotational torque to the magnetic disk via the hub. The drive pin rotates along with the spindle and is driven simultaneously by a single motor.

In such a pin drive type disk drive, the rotational torque is transmitted to the magnetic disk only after the drive pin is engaged with the engagement hole of the hub. For this reason, there is often a time delay between the starting force of the motor and the rotation start timing of the magnetic disk, and the movable head often makes a shocking external contact with the magnetic disk that is still stationary.

That is, in the conventional pin drive type drive device, the surface of the magnetic disk in a stationary state, which has not been wiped by the cleaning member in the disk cartridge, is often tapped by the movable head. At this time, if dust adhered to the disk surface, the dust was struck by the movable head and struck into the magnetic layer, or stuck to the surface, causing dropout during subsequent use.

[Object of the Invention]

The present invention prevents dust from being driven into or stuck to the inside of the magnetic disk when the magnetic head makes external contact with the magnetic disk so as to hit its surface.
It is intended to eliminate the dropout of magnetic signals during use.

[Means for solving problems]

According to the present invention, after the surface of the magnetic disk is wiped and dust is removed by the cleaning member originally provided in the disk cartridge, the magnetic head is circumscribed on the magnetic disk, and the magnetic recording surface or the magnetic signal is recorded. It is intended to prevent destruction.

Specifically, as shown in FIG. 1, a restraint means 25 for holding the head support 15 for supporting the movable magnetic head 13 at the standby position, and a control means for controlling the operation of the restraint means 25.
26, the movable head 13 contacts the magnetic disk 3 after the surface of the magnetic disk 3 is clean.

The restraint means 25 is composed of, for example, an electromagnetic solenoid 27, and the plunger 28 is pushed forward by a spring 29, and a lock pin 30 provided at the tip of the plunger 28 is used for the head support member.
By receiving and supporting the head 15, the head support 15 is prevented from moving against the biasing force of the biasing means 17. When a drive current is applied to the solenoid 27 from this state, the plunger 28 withdraws against the spring 29, the lock pin 30 withdraws from the swing locus of the head support 15, and the head support 15 descends. Allow rocking.

A control means 26 is provided to regulate the timing of the release operation of the restraint means 25. After determining that the magnetic disk 3 has rotated at least by a predetermined angle θ described later, the control means 26 issues a release command signal to switch the restraint means 25 from the restrained posture to the posture in which the restraint is released.

In a general disc cartridge applied to the apparatus of the present invention, for example, a protrusion 20 provided on the inner wall of the disc cartridge 1 sandwiches the liner 21 from both sides to forcefully and locally the surface of the magnetic disc 3 passing therethrough. The cleaning member 19 is provided so that the cleaning member 19 can be wiped by contacting with each other. The angle θ between the contact center of the magnetic head 13 on the magnetic disk 3 (usually the center of the head window 14) and the center of the cleaning member 19 on the rotation better side of this.
Is the predetermined angle θ.

As a specific means for the control means 26 to determine the amount of rotation of the magnetic disk 3, for example, the photo sensor 31 detects the rotation passage of the index hole 23 provided in the magnetic disk 3, and a predetermined angle θ from the first detection signal. Magnetic disk 3
It is configured to issue a release command signal to the restraining means 25 after waiting a time required for the rotation of the. The time required for the magnetic disk 3 to rotate at a predetermined angle θ can be calculated from the number of rotations of the magnetic disk 3 per unit time in a steady state, and the value is set in advance in the control means 26 under operating conditions. I will give it as one.

Generally, the magnetic disk 3 is rotationally driven at a high speed. Therefore, the control means 26 may issue a release command signal after several rotations with reference to the activation of the motor M for driving the magnetic disk 3. Strictly speaking, it is sufficient to determine that the motor M rotates one rotation from the start of the motor M and the motor M rotates by the predetermined angle θ. Compared to the case where the rotation amount of the magnetic disk 3 is directly determined, an extra waiting time of one rotation is required because the drive pin is engaged with the engagement step portion 7 of the hub 4 at a maximum of one rotation. This is because it is necessary to consider that there is a free rotation of.

In order to detect the rotation amount of the magnetic disk 3, as described above, in addition to the time and the rotation speed, the movement change of the optical or magnetic index fixed to the rotating body is measured by an optical sensor or a magnetic sensor. You can also do it. The object to be measured when determining the rotation speed may be any member as long as it is a rotating body between the magnetic disk 3 and the motor M that drives the magnetic disk 3.

〔The invention's effect〕

According to the present invention, when the magnetic disk 3 is rotationally driven by at least the predetermined angle θ, and the surface wiped cleanly by the cleaning member 19 is rotationally transferred to the contact position with the magnetic head 3, the magnetic head is moved to the magnetic disk 3. Since 13 is circumscribed, it is possible to eliminate dust attached to the surface of the magnetic disk 3 from being hit by the magnetic head 13 on the magnetic recording surface or sticking to the surface.
It is possible to prevent the magnetic recording surface from being physically destroyed or to make it impossible to read the recorded magnetic signal, and it is possible to eliminate dropout due to the fixation of dust on the magnetic recording surface. This not only prevents partial loss of data and programs recorded on the magnetic disk 3, but also prevents loss of file control blocks for managing data files and program files, and It is possible to prevent serious accidents such as unreadable data from occurring.

〔Example〕

 1 to 4 show an embodiment of the present invention.

In FIG. 2, the magnetic disk drive device holds the disk cartridge 1 carried by a loading mechanism (not shown) in a fixed position by positioning pins 2.2, and as shown in FIGS. By fixing the hub 4 fixed at the center of the disk 3 by a pair of upper and lower collets 5, a drive pin 6 provided near the peripheral edge of the lower collet 5 engages with an engagement step portion 7 of the hub 4. The magnetic disk 3 is rotationally driven via the hub 4.

In FIG. 3, a central hole 4a into which a centering cone 5a provided in a lower collet 5 is fitted is generally known as a vertically penetrating shape in the hub 4. A groove 4b is formed around the center hole 4a so as to allow the drive pin 6 to be fitted therein.
An engaging step portion 7 is formed at the cut portion (see FIG. 4).

A head carriage 9 is supported on the chassis on the inner side of the positioning pins 2.2 so as to be able to move forward and backward through two guard rails 8. The head carriage 9 is driven forward and backward by a step motor 10 provided on the side via a pinion rack mechanism 11, and a pair of upper and lower magnetic heads 12 and 13 arranged at the tip of the head carriage 9 are connected to the head window 14 of the disk cartridge 1. Move along.

Disk cartridge 1 of both magnetic heads 12 and 13
The magnetic head 12 located on the lower surface side of the head carriage 9
The other magnetic head 13 is fixed to the head carriage 9
It is fixed to a head support pair 15, which is supported so as to be vertically swingable. The head support 15 is urged downward by an urging means 17 composed of a torsion coil spring arranged around an oscillating shaft 16 thereof. The head support 15 is outside the loading area of the disk cartridge 1 when not in use and will be described later. The waiting state is maintained by the restraint means 25 that operates.

In FIGS. 3 and 4, a cleaning member 19 for forcibly wiping the surface of the magnetic disk 3 to remove dust is provided on the inner surface of the disk cartridge 1 opposite to the head window 14 sandwiching the hub 4. Have. The cleaning member 19 is a trapezoidal protrusion 20 that is bulged in an opposed manner from the upper and lower inner walls of the disk cartridge 1 in a plan view.
And the upper and lower non-woven liners 21 that are deformed by the protrusions 20 in a U-shape. In the figure, reference numeral 22 is an index window, 23 is an index hole provided in the magnetic disk 3, and M is a motor.

The present invention is characterized in that the timing of the downward swing of the head support 15 is set as follows in relation to the rotation state of the magnetic disk 3 in the magnetic disk drive device as described above.

That is, when the magnetic head (hereinafter referred to as the movable head) 13 fixed to the head support 15 contacts the magnetic disk 3, the surface of the magnetic disk 3 is reliably cleaned by the cleaning member 19 before this. Be present. Therefore, a control means 26 for controlling the operation of the restraining means 25 for restricting the downward swing of the head support 15 is provided.

The restraint means 25 comprises an electromagnetic solenoid 27, and a plunger 28 is urged forward by a spring 29 so that a lock pin 30 fixed to the tip of the plunger 28 receives and supports the lower surface of the head support 15 when not energized. Then, the downward swing is urged
Block against 17 bias. When a drive current is applied to the solenoid 27, the restrained posture described above is released. That is, the plunger 28 retreats against the spring 29, and the lock pin 30 retreats out of the swing locus of the head support 15 to assume the restraint releasing posture.

A control means 26 is provided to regulate the release operation timing of the restraint means 25. This control means 26 is provided.
The control means 26 receives the detection signal from the photo sensor 31 for detecting the rotation passage of the index hole 23, waits at least the time necessary for the magnetic disk 3 to rotate about half a turn from the first detection signal, and then restrains the magnetic disk 3. Means 25 Solenoid 27
A release command signal is issued so that the drive current is applied to the.

Specifically, the contact center of the movable head 13 with the magnetic disk 3, that is, the center position of the head window 14 in the longitudinal direction, and the center position of the cleaning member 19, an angle θ (180
)), And the time required for the magnetic disk 3 to rotate at this predetermined angle θ is calculated from the number of rotations of the magnetic disk 3 per unit time during steady operation.
After 31 first detects the passage of the index hole 23, it waits for the above-mentioned time to elapse, and is set to issue a cancellation command signal. Therefore, the control means 26 includes a clock and its counter, a memory for storing the waiting time, and the like. When the rotation start of the magnetic disk 3 is determined by the index hole 23 as described above, there is a difference in the time when the control means 26 issues the release command signal depending on the position of the index hole 23 before the rotation, and the magnetic disk 3
When converted to the amount of rotation, a width of 180 ° to 360 ° occurs.

As described above, if the timing at which the movable head 13 circumscribes the magnetic disk 3 is delayed by the restraining means 25 and the control means 26 after the surface of the magnetic disk 3 has been cleaned by the cleaning member 19, dust will move to the movable head 13. Thus, it can be prevented from being driven into the magnetic recording surface.

[Modification] The present invention can be implemented by modifying a part of the above embodiment as follows.

First, regarding the restraint means 25, the plunger 28 is always urged in the retracting direction by the spring 29, the plunger 28 is connected to the head support 15, and the drive current is applied to the solenoid 27. At this time, the plunger 28 moves downward against the spring 29, so that the head support 15 can swing downward. That is, in this case, the solenoid 27 also serves as the urging means for the head support 15.

Second, the head support 15 is supported so that it can be moved toward and away from (in parallel with) the magnetic disk 3 in the thickness direction thereof.

Thirdly, the control means 26 is based on the start of the motor M,
It is configured to issue a release command signal when the number of rotations reaches 1.5 or more.

Fourthly, the photo interrupter makes it possible to detect the amount of rotation of any of the rotating members from the motor M to the magnetic disk 3, and the control means 26 is configured to issue a release command signal based on the detection result.

Fifth, a magnetic disk drive device of the type in which the hub 4 is held by magnet attraction and the drive pin 6 is projected and retracted in the axial direction to engage with the hub 4 (Japanese Utility Model Publication No. 57-102071). Format).

Incidentally, in the case of holding the hub 4 by the above-mentioned magnet attraction, the position of the cleaning member 19 provided in the disk cartridge 1 is closer to the head window 14 than that described in the embodiment. The predetermined angle θ is about 60 degrees.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a perspective view conceptually showing a magnetic head and its peripheral structure, FIG. 2 is a schematic plan view of a magnetic disk drive device, and FIG. 3 is FIG. 4 is a sectional view taken along line AA in FIG. 4, and FIG. 4 is a plan view of the disk cartridge. 1 ... disk cartridge, 3 ... magnetic disk, 4 ... hub, 6 ... drive pin, 9 ... head carriage, 12/13 ... magnetic head, 15 ... head support, 17 ... biasing means , 19 ... Cleaning member, 23 ... Index hole, 25 ... Restraint means, 26 ... Control means, 27 ... Solenoid, 31 ... Photo sensor.

Claims (2)

(57) [Claims] 1. A magnetic disk 3 is provided with two magnetic heads 12 and 13 corresponding to both front and back surfaces, at least one of which is in contact with or separated from the magnetic disk 3 via a head support 15. A drive pin that is supported so as to be capable of reciprocating movement, urges the head support 15 toward the magnetic disk 3 by urging means 17, and engages a hub 4 fixed at the center of the magnetic disk 3 outside the center. In a magnetic disk drive device which is rotationally driven by 6, the head support 15 is held against the urging force of its urging means 17 in a standby state in which the magnetic head 13 is located away from the magnetic disk 3. Restraint means 25 and this restraint means 25
And a restraint means 26 for restraining the movement of the head restraint means 25. The restraint means 25 is configured to be switchable between a posture that restrains the head support 15 from moving toward the magnetic disk 3 and a posture that releases the restraint. The angle θ between the contact center of the magnetic head 13 on the magnetic disk 3 and the cleaning member 19 provided in the disk cartridge 1 on the rotation side of the magnetic disk 3 and locally contacting the magnetic disk 3 is defined as follows. The rotation of the index hole 23 provided in the magnetic disk 3 is detected, and the magnetic disk 3 is detected from this first detection signal.
The control means 26 temporally determines that the vehicle has rotated at least the predetermined angle θ, and the restraint means 25 switches from the restrained posture to the posture for releasing the restraint by the release command signal issued based on this determination result. A magnetic disk drive device characterized by being configured. 2. A magnetic disk 3 is provided with two magnetic heads 12 and 13 corresponding to both front and back surfaces, at least one of which is in contact with or separated from the magnetic disk 3 via a head support 15. A drive pin that is supported so as to be capable of reciprocating movement, urges the head support 15 toward the magnetic disk 3 by urging means 17, and engages a hub 4 fixed at the center of the magnetic disk 3 outside the center. In a magnetic disk drive device which is rotationally driven by 6, the head support 15 is held against the urging force of its urging means 17 in a standby state in which the magnetic head 13 is located away from the magnetic disk 3. Restraint means 25 and this restraint means 25
And a restraining means 25 for restraining the movement of the head supporting body 15 from approaching toward the magnetic disk 3 and a posture for releasing the restraint. The angle θ between the contact center of the magnetic head 13 on the magnetic disk 3 and the cleaning member 19 provided in the disk cartridge 1 on the rotation side of the magnetic disk 3 and locally contacting the magnetic disk 3 is defined as θ. The motor M that stipulates and drives the magnetic disk 3 to rotate is 1
The control means 262 determines that the rotation means has rotated at least the predetermined angle θ, and the restraining means 25 is configured to switch from the restrained posture to the posture to release the restraint by a release command signal issued based on the determination result. A magnetic disk drive device characterized by: