JPH0423344B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic disk device that can smoothly rotate a magnetic disk when power is turned on.

As is well known, a magnetic disk device writes information to or reads information from a magnetic disk by moving a magnetic head in the radial direction of a magnetic disk that is rotating at high speed. .

By the way, lubricant is applied to the surface of the magnetic disk to protect the disk surface.
Due to this lubricant, the magnetic head sticks to the magnetic disk while the magnetic disk device is stopped, causing the problem that the magnetic disk does not rotate normally when the power is turned on.

Conventionally, the above problem has been solved by first moving the magnetic head several tracks in the radial direction of the magnetic disk and then rotating the magnetic disk when the power is turned on. However, if the magnetic head is moved when the power is turned on and then the magnetic disk is rotated, the magnetic head will be moved even if the magnetic head is not attached to the magnetic disk. The disadvantage is that it takes a long time to become usable.

The present invention was made in view of the above circumstances, and
The magnetic disk can be rotated smoothly and quickly when the device is started, such as when the power is turned on, and even if the magnetic head sticks to the magnetic disk and the magnetic disk does not rotate, the magnetic disk can be rotated reliably. The object of the present invention is to provide a magnetic disk device capable of rotating a magnetic disk, which comprises: a magnetic disk rotation means for rotating a magnetic disk; a rotation detection means for detecting rotation of the magnetic disk; and a rotation detecting means for detecting rotation of the magnetic disk. A magnetic head moving means for moving a magnetic head for writing or reading in the radial direction of the magnetic disk, and a control circuit for controlling the magnetic head moving means and the magnetic disk rotating means, the control circuit being configured by a magnetic head. a rotation starting section for starting a disk rotating means; a magnetic head adhesion detecting section for detecting whether or not there is adhesion between the magnetic head and the magnetic disk based on a signal from the rotation starting section and a signal from the rotation detecting means; When this magnetic head adhesion detection section outputs a signal indicating the presence of adhesion, it outputs a signal to the magnetic disk rotating means to stop the rotation of the magnetic disk, and also outputs a signal to the magnetic head moving means to stop the rotation of the magnetic disk. A magnetic head adhesion release unit that outputs a signal to move the magnetic head by multiple tracks, and a count of the number of signals that drive this magnetic head adhesion release unit, and when the number of times matches a preset number, the control is stopped. and a control abort determination section.

Hereinafter, the present invention will be specifically explained based on the drawings.

1 to 5 show an embodiment of the present invention, and 1 in the figures is a step motor (magnetic head moving means) having rotating shafts 1a and 1b protruding from both ends. Rotating shaft 1a of this step motor 1
In this case, the head is sent through the transmission mechanism 2, and the mechanism 3
A lock mechanism 4 for locking the rotation of the step motor 1 is also connected to the rotating shaft 1b.

The head feeding mechanism 3 includes a pair of sliding shafts 5 and 6.
A head arm 9 for supporting a magnetic head 8 is fixed by screws 10 to a carriage 7 which is slidably provided on the head. The transmission mechanism 2 includes a cylindrical pulley 11 mounted on the rotating shaft 1a of the step motor 1, and a cylindrical pulley 11 mounted on the rotation shaft 1a of the step motor 1.
and a steel belt 12 wound around and fixed to the carriage 7.
When rotates, the pulley 11 and the steel belt 12
The carriage 7 of the head feeding mechanism 3 moves through the magnetic disk 13, whereby the magnetic head 8 attached to the tip of the head arm 9 maintains a mutually spaced relationship with the magnetic disk 13.
It is designed to move in the radial direction of 3.

The magnetic disk 13 is fixed to a rotating shaft 16 of a spindle motor (magnetic disk rotating means) 15 having an outer rotor 14, and by rotating the spindle motor 15, the magnetic disk 13 rotates at high speed in a horizontal plane. It's summery. Further, a detection plate 18 is provided at the lower part of the hub 17 that is fixed to the upper end of the rotating shaft 16 and supports the magnetic disk 13. A detector 21 is attached to a base 20 to which the stator 19 of the spindle motor 15 is fixed, at a position facing the plate 18 to be detected, and this detector 21 detects the position of the plate 18 to be detected. By this detection, the positions of a plurality of sectors of the magnetic disk 13 (storage areas obtained by dividing a plurality of concentric tracks formed on the magnetic disk 13 at equal intervals in the radial direction at equal intervals in the circumferential direction) are detected. I'm starting to do that.

The lock mechanism 4 includes a toothed pulley 22 mounted on the rotating shaft 1b of the step motor 1, and a toothed portion 2 that meshes with a gear portion 22a of the toothed pulley 22.
3a formed at one end; a solenoid 24 pin-coupled to the other end of this arm 23;
The solenoid 24 is fixed with a screw 25a, and the solenoid 24 is constructed of a backing plate 25 which pivotally supports the center of the arm 23. And the patch plate 2
5 is fixed to the casing C by a screw 25b, and by energizing the solenoid 24,
The arm 23 rotates around its center as a fulcrum,
The toothed pulley 22 meshing with the toothed portion 23a of the arm 23 is released. Further, the step motor 1 of the gear portion 22a of the toothed pulley 22
A detected portion 22b and a stopped portion 22c protruding in the radial direction of the toothed pulley 22 are formed on the sides. The detected portion 22b is the screw 26C.
When inserted into the groove 26a of the O-track detection sensor 26 attached to the casing C,
The sensor 26 detects that the magnetic head 8 has come to the O-track position of the magnetic disk 13, and the stopper 26b provided between the sensor 26 and the casing C detects the stopped portion. By contacting the magnetic head 22c, the distance that the magnetic head 8 moves over the magnetic disk 13 is regulated.

Above step motor 1, spindle motor 1
5. The solenoid 24 is connected to a control circuit 27, which controls the step motor 1, spindle motor 15,
A command is output to the solenoid 24. This rotation detection means 28 detects the rotation of the magnetic disk 13 by detecting a mark provided at a position where a photoreflector attached to the fixed side of the spindle motor 15 faces a photoreflector on the rotating side. It is. The control circuit 27 is connected to an alarm 29 such as a warning light or a buzzer. In addition, signals from the detection 21, sensor 26, etc. are also input, and the control circuit 27 performs processing for writing information to and reading information from the magnetic disk 13, in addition to processing when the power is turned on according to the present invention. etc. are also being controlled.
Incidentally, the rotation detecting means 28 detects the magnetic disk 1.
It is sufficient that the rotation of the magnetic disk 13 or the spindle motor 15 can be detected by using the signal from the detector 21, or as described above, a detector for detecting the rotation of the magnetic disk 13 or the spindle motor 15 may be separately provided. The current or the like may be detected.

Next, the operation of the magnetic disk device configured as described above will be explained based on FIGS. 6 to 8.

FIG. 6 is a flowchart illustrating the process performed in the control circuit 27 when the power is turned on. First, when the power is turned on, the control circuit 27
7 sets the count value N to 1 in order to count the number of times, as shown in step S1. Then,
Give a command to the spindle motor 15 (step S
2), after an appropriate amount of time (for example, 5 seconds),
It is determined whether a signal from the rotation detection means 28 is input (see step S3).

At this time, if the signal from the rotation detecting means 28 is input (if the magnetic disk 13 is rotating), the control circuit 27 completes the process when the power is turned on, and sends a plurality of ( In Fig. 7d, three pulses are output. At this time, a certain constant voltage (for example, about 5V) is automatically applied to the solenoid 24 when the power is turned on, and the lock mechanism 4 is released, but just in case, a pulse voltage higher than the above-mentioned constant voltage (for example, 12V) is applied to the solenoid 24. ) is applied. This pulse voltage causes the lock mechanism 4 to
is reliably released, the control circuit 27 outputs a command to the step motor 1, moves the magnetic head 8 in the radial direction of the magnetic disk 13, and performs information writing and reading processing.

On the other hand, in step S3, the rotation detection means 2
If the signal from 8 is not input (if the magnetic head 8 is stuck and the magnetic disk 13 is not rotating), the control circuit 27 determines whether the count value N is 3 (see step S4). ).
If the count value N is smaller than 3, the count value N is incremented by 1 as shown in step S5, and then a command to stop the spindle motor 15 is output (see step S6). Next, as shown in FIG. 8d, a pulse voltage is applied to the solenoid 24 to securely release the lock mechanism 4, and then,
A command is output to the step motor 1 to move the magnetic head 8 several tracks (for example, 7 to 8 tracks) in the radial direction of the magnetic disk 13 (see step S7). Then, returning to step S2, a rotation command is again given to the spindle motor 15, and after an appropriate period of time, it is determined whether or not the magnetic disk 13 is rotating (see step S3). At this time,
If the adhesion of the magnetic head 8 can be released by moving the magnetic head 8, the magnetic disk 13 will rotate, and the control circuit 27 will carry out the above-mentioned normal processing of writing and reading information to the magnetic disk 13. .

Further, the process shown in step S7 (starting the step motor 1 and moving the magnetic head 8 to the magnetic disk 1)
If the magnetic disk 13 does not rotate even after repeating the process of moving the magnetic disk several tracks in the radial direction of step 3 twice, the count value N becomes 3, so the process proceeds to step S8 based on the determination in step S4. The control circuit 27 performs processing in the event of an abnormality, such as outputting an output in response to an alarm 29 and notifying an operator or the like.

Note that step S in the flowchart shown in FIG. 6 has the following relationship with the functional block diagram shown in FIG.

That is, the control circuit 27 shown in FIG.
The rotation starting section 100 performs the process shown in step S2, and the magnetic head adhesion detecting section 101 performs the process shown in step S3. After performing the process shown in FIG.
02 performs the processing shown in steps S6 and S7, and the control abort determination section 103 performs the processing shown in step S1 and steps S4, S5, and S8.

Specifically, the rotation starting section 100 outputs a signal for rotating the magnetic disk 13 to the spindle motor 15 of the magnetic disk rotating means 4 (see step S2).

In the magnetic head adhesion detection section 101, when the rotation starting section 100 outputs a signal for rotating the magnetic disk 13 to the magnetic disk rotation means (spindle motor 15), the rotation detection means 28 detects whether the magnetic disk 13 is rotated. When it is detected that the magnetic head 8 is not attached to the magnetic disk 13, it is determined that the magnetic head 8 is attached to the magnetic disk 13 (see step S3).

When the magnetic head adhesion detecting section 101 outputs a signal indicating the presence of adhesion between the magnetic head 8 and the magnetic disk 13, the magnetic head adhesion releasing section 102 controls the magnetic disk rotating means (spindle motor 15). outputs a signal to stop the rotation of the magnetic disk 13 (see step S6), and outputs a signal to move the magnetic head 8 by a plurality of tracks to the magnetic head moving means (step motor 1) (see step S7). .

On the other hand, the control stop determination unit 103 counts the number of times the signal is output from the magnetic head adhesion release unit 102 to the magnetic head moving means (step motor 1), and the number of times is determined by a preset number (N= 3), an alarm is issued and the control is stopped.

The signal output from the magnetic head adhesion release unit 102 to the magnetic head moving means (step motor 1), which is counted by the control stop judgment unit 103, is a signal from the magnetic head adhesion detection unit 101 indicating the presence of adhesion. Therefore, this signal indicating the presence of adhesion is defined as a "signal for driving the magnetic head adhesion release unit 102."

In the magnetic disk device according to the present invention as described above, even though the magnetic disk 13 is driven (by the rotation starter 100),
When the magnetic disk 13 does not rotate, it is determined that the magnetic disk 13 and the magnetic head 8 are stuck (based on the magnetic head adhesion detection section 101),
By moving the magnetic head 8 by a plurality of tracks, the adhesion between the magnetic head 8 and the magnetic disk 13 can be released (the magnetic head adhesion releasing section 1
02).Furthermore, if the adhesion between the magnetic head 8 and the magnetic disk 13 cannot be released even after the magnetic head 8 has been moved a preset number of times, it is determined that this is abnormal. (control abort determination unit 10
3), such a series of operations provides the effect of starting up the magnetic disk device extremely smoothly and efficiently.

[Brief explanation of drawings]

1 to 5 show one embodiment of the present invention, in which FIG. 1 is a partially cutaway plan view, FIG. 2 is a sectional view of the spindle motor section, and FIG. 3 is a side view of the lock mechanism section. , FIG. 4 is an exploded perspective view of the lock mechanism.
FIG. 5 is a block diagram of the electrical part, FIGS. 6 to 8 explain the operation of the magnetic disk device according to the present invention, FIG. 6 is a flowchart showing the processing contents of the control circuit, and FIG. is a timing chart showing normal operation, where a is the power supply, b is the spindle, c is the adhesive check (rotation detection means check), d is the solenoid drive, e is the stepper excitation, f is the solenoid current, and Figure 8 is a timing chart showing the operation when adhesion occurs, and a
is the power supply, b is the spindle, c is the adhesive check,
(Rotation detection means check), d is solenoid drive,
e indicates stepper excitation, and f indicates solenoid current. 1...Step motor (magnetic head moving means),
8...Magnetic head, 13...Magnetic disk, 15...Spindle motor (magnetic disk rotation means), 27
...Control circuit (rotation starting section 100, magnetic head adhesion detection section 101, magnetic head adhesion release section 102, control stop judgment section 103), 28...Rotation detection means.

Claims (1)

[Scope of Claims] 1. A magnetic disk rotating means for rotating a magnetic disk, a rotation detecting means for detecting rotation of the magnetic disk, and a magnetic head for writing or reading information on the magnetic disk at a radius of the magnetic disk. a control circuit for controlling the magnetic head moving means and the magnetic disk rotating means, the control circuit comprising: a rotation starter for starting the magnetic disk rotating means; a magnetic head adhesion detector for detecting the presence or absence of adhesion between the magnetic head and the magnetic disk based on a signal from the starter and a signal from the rotation detection means; and a signal indicating the presence of adhesion from the magnetic head adhesion detector. A magnetic head adhesion release device that outputs a signal to the magnetic disk rotating means to stop the rotation of the magnetic disk and a signal to the magnetic head moving means to move the head by a plurality of tracks when the magnetic disk is output. and a control abort determining unit that counts the number of times the signal is applied to drive the magnetic head adhesion releasing unit and stops the control when the number of times matches a preset number. magnetic disk device.