JPS62295262A - Driving method for magnetic disk unit - Google Patents

Abstract

PURPOSE:To make it possible to separate a magnetic disk and a magnetic head in adhered state by rotating the magnetic disk, and at same time, moving a head carriage when the magnetic head and magnetic disk are stuck together. CONSTITUTION:After starting a magnetic disk unit, if an index detector 4 does not detect an index of the magnetic disk and an index signal is not generated for more than a specified time, for instance one second or over, a CPU3 judges this state as adhesion of the magnetic disk, and rotates a stepping motor 7 that drives a carriage, in addition to a motor 8 for rotating the magnetic disk already rotated through a driver 6. That is, the motor 8 for rotating the magnetic disk and the stepping motor 87 that moves the carriage are driven simultaneously. Consequently, composite force of driving force of the two motors surpasses adhesive force, and adhesion of the magnetic disk can be released.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for driving a magnetic disk device, and more specifically, when a magnetic head and a magnetic disk are stuck together, the seek The present invention relates to a method for driving a magnetic disk device that has a function of releasing this by operation.

[Prior Art] Conventional magnetic disk drives include those in which head loading is performed after a magnetic disk is completely inserted, and those without a head loading mechanism, in which the magnetic head is constantly loaded from the time a magnetic disk is inserted until the time it is removed. and one in which the magnetic disk is in contact.

[Problems to be Solved by the Invention] By the way, in the case of a magnetic disk device without a head loading mechanism, the process from the time a magnetic disk is inserted into the magnetic disk device to the time when the magnetic disk is ejected.

Because the head and the surface of the magnetic disk are always in contact,
If you forget to take out the magnetic disk or need to leave the magnetic disk in for a long time,
The problem is that the head and magnetic disk stick together due to lubricant seeping out of the magnetic disk, and even if an attempt is made to start the drive motor, the sticking cannot be overcome and the motor locks.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a method of rotating the magnetic disk and moving the head carriage when the magnetic head and the magnetic disk stick together. Adopted.

[Operation] When the method described above is adopted, the combined force of the driving force of the motor that rotates the magnetic disk and the driving force of the motor that moves the carriage exceeds the adhesion force between the magnetic disk and the magnetic head, so that the adhesion is prevented. With the magnetic disk attached? The air head can be separated from the air head.

[Example] The details of the method of the present invention will be explained below with reference to one drawing.

For example, in the case of a 3.5-inch magnetic disk, it has been experimentally revealed that the sticking force between the magnetic disk and the magnetic head is 300 g*cta near track "00."

On the other hand, the starting torque of the motor that rotates the magnetic disk is about 1003 acra, and in order to simply release this sticking, the starting torque for rotating the magnetic disk must be tripled.

If the sticking force is converted to duram, it is 300g5 cm/
3.875cffl=7? G There is te.

Note that 3.875 cm is the average distance from the center of the magnetic disk to track r00J on the "0" side and the "1" side.

On the other hand, the radius of the pulley of the stepping motor for moving the carriage is, for example, 0.595 cm in the case of a 3.5-inch magnetic disk drive.

Based on the above premise, a method for releasing the sticking force between the magnetic disk and the magnetic head is as shown in FIG. 1.

In FIG. 1, the reference numeral 1 indicates a magnetic disk, and the reference numeral 2 indicates the center of the magnetic disk. Also, in Fig. 1, what is indicated by the symbol F1 is the sticking force of the magnetic disk, which is 77 g (300 g-cm), and which is indicated by the symbol F2.
What is shown is the driving force of the carriage (head) by the stepping motor.

teog at 400PPS. Also, code F3
What is shown is the starting force of the drive motor for the magnetic disk, which is 26
g (100 g IIC layer).

Now, if F2+F3>F, the sticking of the magnetic disk can be released.

If we apply the specific numbers mentioned above, F1 = 77g
, F 2 = 180g, F 3 = 28g, so r (28g)”・(tsog)2>F, (
77gl).

In the case of this embodiment, the above-mentioned equation holds if the stepping motor is driven at 400 PPS or less, and the magnetic disk device may be driven at 333 PPS WAX.

By the way, to implement the above-mentioned unsticking method,
For example, a method as shown in FIG. 2 is adopted.

In FIG. 2, the reference numeral 3 indicates a CPU (central processing unit), which constantly monitors the signal from the index detector 4, and drives the stepping motor 7 and magnetic disk drive motor via drivers 5 and 6, respectively. Rotation control of 8.

Now, suppose that the magnetic disk device is started, the index detector 4 does not detect the index of the magnetic disk, and the index signal remains unchanged for a predetermined period of time.

For example, if this does not occur for more than one second, the CPU 3 determines that the magnetic disk is stuck, and drives the carriage in addition to the motor 8 for rotating the magnetic disk, which is already being rotated via the driver 6. The stepping motor 7 is rotated.

That is, the motor 8 for rotating the magnetic disk and the stepping motor 7 for moving the carriage are simultaneously driven.

As a result, the combined force of the driving forces of both motors overcomes the sticking force, making it possible to release the sticking of the magnetic disk.

[Effects] As is clear from the above description, according to the present invention, when the magnetic head and the magnetic disk stick together, the motor that rotates the magnetic disk and the motor that moves the carriage on which the magnetic disk is mounted are activated. Since a method of simultaneously rotating the two motors is adopted, the combined force of the driving forces of the two motors can overcome the sticking force of the magnetic disk and release the sticking.

Further, by employing the above-described method, there is no need to use a large torque motor for rotating the magnetic disk, and power consumption can be significantly reduced.

[Brief explanation of the drawing]

The drawings are for explaining one embodiment of the present invention, and FIG. 1 is an explanatory diagram of force relationships, and FIG. 2 is a block diagram of a control circuit. 1...Magnetic disk 2...Center of the magnetic disk 3...CPU 4...Index detector 5.6...Driver 7...Stepping motor 8...Motor for rotating the magnetic disk Figure 2

Claims (1)

[Claims] If the magnetic head and magnetic disk stick together, this sticking condition is detected and the motor for rotating the magnetic disk is activated.
A method for driving a magnetic disk device, characterized in that a motor for moving a carriage on which a magnetic head is mounted is simultaneously driven.