JPH04281277A - Magnetic disk driving device - Google Patents

Abstract

PURPOSE:To improve reliability and to reduce generation of dust by loading stably without allowing a slider to contact a magnetic disk thereby eliminating the damage of the slider and the magnetic disk and the head-or-crash in the magnetic disk driving device of a loading/unloading system. CONSTITUTION:To a loading means making a flexure 1 with a slider 3 close to the magnetic disk 5, the loading means is controlled by current in a control part 9, the driving speed of the flexure 1 of the loading means is lowered and the loading is slowly carried out.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive device.

0002

2. Description of the Related Art In a magnetic disk drive device, information is read and written while a slider having a magnetic head is slightly raised above the surface of the magnetic disk. This slider flies above the surface of the magnetic disk by an airflow generated over the surface of the magnetic disk by rotation of the magnetic disk.

A contact start/stop method is used as a loading method for conventional magnetic disk drive devices. The contact start/stop method means that the magnetic disk begins to rotate at startup.
The rotational speed of the magnetic disk becomes smaller than the predetermined rotational speed until the rotational speed of the magnetic disk reaches a certain rotational speed and the slider floats due to the airflow above the magnetic disk and leaves the magnetic disk, and just before it stops. From the time the slider descends onto the magnetic disk until the rotation of the magnetic disk completely stops, the slider contacts and slides against the magnetic disk. Therefore, in this method, since the slider and the magnetic disk slide against each other when the magnetic disk is started or stopped, there is a high risk of scratches on the surface of the slider or the magnetic disk.

Furthermore, in the contact start/stop method, since the slider and the magnetic disk slide against each other when starting or stopping the magnetic disk, the contact start/stop area (hereinafter referred to as the shipping zone) is However, no data was recorded in the shipping zone for data protection. For this reason, the data recording capacity is reduced by the shipping zone, which is an obstacle to realizing a high recording capacity.

[0005] Therefore, from the time the magnetic disk starts rotating until it reaches a predetermined number of rotations, and until the number of rotations of the magnetic disk becomes smaller than the predetermined number of rotations and stops,
A loading/unloading method is being researched in which the slider is separated from the magnetic disk so that the slider and magnetic disk do not slide.

Next, a conventional magnetic disk drive device equipped with a load/unload method will be explained. Figure 6
1 is a perspective view showing a conventional magnetic disk drive device.

In FIG. 6, reference numeral 1 denotes a flexure composed of a leaf spring, and the flexure 1 is fixed to a carriage arm 4 that is movable in a direction transverse to data tracks recorded on a magnetic disk 5. 2 is a gimbal formed by a thin plate provided at the tip of the flexure 1. 3
is a slider having a magnetic head, and the slider 3 is fixed to the flexure 1 via a gimbal 2. The gimbal 2 is provided to cause the slider 3 to follow the undulations of the magnetic disk 5.

A load pin 6 is provided on the side of the flexure 1 opposite to the magnetic disk 5 so as not to come into contact with the flexure 1, and is spaced apart from the flexure 1, and is attached to the support arm 7. 8 is a solenoid that drives the support arm 7 toward the magnetic disk 5 side. The support arm 7 supports a load pin 6 attached to the support arm 7 when loading the slider 3 onto the magnetic disk 5.
This causes the flexure 1 to be displaced toward the magnetic disk 5. Further, the support arm 7 is driven by supplying a constant current to the solenoid 8 to change the iron core of the solenoid 8 from a protruding state to a retracted state.

In this way, the support arm 7 is attached to the magnetic disk 5.
By displacing the slider 3 to the side, the load pin 6 attached to the support arm 7 presses the flexure 1 and bends the flexure 1 toward the magnetic disk 5, bringing the slider 3 closer to the rotating magnetic disk 5. The slider 3 can be made to float above the magnetic disk 5.

0010

[Problems to be Solved by the Invention] Currently, there are very few magnetic disk drive devices equipped with a slider loading mechanism. The reason for this is that if the slider loading and unloading operations are repeated in the conventional configuration, a head crash may occur, and as a result, the reliability of the magnetic disk drive device cannot be ensured.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a magnetic disk drive device provided with a loading means for loading a slider onto a magnetic disk without causing a head crash. The object of the present invention is to provide a highly reliable magnetic disk drive device.

0012

[Means for Solving the Problem] In order to solve this problem, the present inventor repeatedly performed loading and unloading operations of the slider on the magnetic disk in the conventional configuration, and investigated the cause of the head crash. . As a result, it was found that the following two points caused head crashes.

The first cause is the loading attitude of the slider at the moment the slider is loaded onto the magnetic disk. When the slider is loaded onto the magnetic disk in the conventional configuration, the surface of the slider facing the magnetic disk is maintained in a state substantially parallel to the magnetic disk.
There were cases where the slider could not recover its posture. In other words, in conventional loading/unloading operations, the iron core of the solenoid is stable only in two states, the protruding state and the retracted state, so the loading speed of the slider is fast, so the surface of the slider facing the magnetic disk is In some cases, it was not possible to maintain the position almost parallel to the Therefore, the surface of the slider facing the magnetic disk is brought close to the magnetic disk in an inclined state with respect to the magnetic disk. For this reason, before the slider reaches the floating position, it contacts the magnetic disk with too much force without generating sufficient positive pressure, damaging the slider and the magnetic disk and causing a head crash.

The second cause is dust generated from the sliding portion of the loading mechanism that loads the slider onto the magnetic disk. When the slider is loaded onto the magnetic disk in the conventional configuration, the iron core of the solenoid has only two stable states, the protruding state and the retracted state, so the loading operation of the slider is performed quickly, and the iron core of the solenoid A large force is applied to the sliding parts. As a result, a large amount of dust is generated from the sliding portion of the iron core of the solenoid, and the generated dust enters the flying gap between the slider and the magnetic disk, causing a head crash.

The present invention is based on the above knowledge regarding the conventional problems, and in order to provide a highly reliable magnetic disk drive device that does not cause head crashes,
The flexure driving speed of the loading means for bringing the flexure closer to the magnetic disk is reduced by controlling the magnitude of the current supplied to the loading means by a control section.

[0016]

[Operation] According to the present invention, when the slider is brought close to the magnetic disk at the time of starting up the magnetic disk drive device, it is possible to bring the slider close to the magnetic disk at a very low speed, so that the surface of the slider facing the magnetic disk is The slider can recover its attitude by maintaining it in a state substantially parallel to the magnetic disk. Therefore, during loading, the slider can fly above the magnetic disk in a stable flying posture, the slider 3 and the magnetic disk 5 will not come into contact with each other, and scratches on the slider 3 and the magnetic disk 5 can be prevented. Further, by setting the speed at which the iron core of the solenoid 8 is displaced from the protruding state to the retracted state or from the retracted state to the protruding state to be low, no large force is applied to the sliding portion of the solenoid 8. As a result, dust generated from the sliding portion of the loading mechanism can be reduced, head crashes caused by dust generated from the sliding portion of the loading mechanism are eliminated, and a highly reliable magnetic disk drive device with a large recording capacity is provided. be able to.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings and FIG. FIG. 1 is a configuration diagram of an embodiment of the present invention. In FIG. 1, a flexure 1, a gimbal 2, a slider 3, a carriage arm 4, a magnetic disk 5
, the load pin 6, and the support arms 7 and 8 are solenoids that are the driving mechanism of the loading means, and these are the same as those in the conventional configuration shown in FIG. 9 is a control unit that controls the current value supplied to the solenoid 8.

Next, FIG. 2 shows the operation of the slider of this embodiment during loading. First, when the magnetic disk 5 is not rotating, no current is supplied to the solenoid 8, so as shown in FIG. 2(A), the iron core 8 of the solenoid 8
0 maintains the protruding state. Therefore, the support arm 7 is located away from the magnetic disk 5, and the magnetic disk 5 and the slider 3 are separated from each other. Further, the load pin 6 and the flexure 1 are also separated.

Next, after the magnetic disk 5 begins to rotate and reaches a predetermined rotational speed, when current is started to be supplied to the solenoid 8, the support arm 7 begins to move in the direction of the magnetic disk 5. Then, when the current supplied to the solenoid 8 is slowly increased, the support arm 7 moves at low speed in the direction of the magnetic disk 5, and the load pin 6 attached to the support arm 7 contacts the flexure 1, moving the flexure 1 toward the magnetic disk 5. Push to the side and bend. This state is shown in FIG. 2(B).

Furthermore, when the current supplied to the solenoid 8 is increased, the load pin 6 pushes the flexure 1 up to a predetermined position. As a result, dynamic pressure begins to be generated on the slider 3, and the slider 3 flies above the magnetic disk 5. At this time, if a negative pressure type slider is used as the slider 3, the resultant force of the positive pressure generated on the slider 3 trying to push it up from the magnetic disk 5 and the force of the flexure 1 trying to separate the slider 3 from the magnetic disk 5 is The slider 3 maintains a constant distance from the magnetic disk 5 at a position that balances the force acting to attract it toward the magnetic disk 5 due to the negative pressure of the slider 3, allowing stable floating without contact between the slider 3 and the magnetic disk 5. can maintain its condition.

After the slider 3 has finished loading the magnetic disk 5, the current supplied to the solenoid 8 is slowly reduced to move the support arm 7 at a low speed in the opposite direction to the magnetic disk 5. This state is shown in Figure 2.
Shown in (C).

The solenoid drive control section 9 has a structure including a low-pass filter 10 as shown in FIG.
This can be realized by the current amplifier 11. When the step signal of the solenoid drive command shown in FIG. 4(A) is given as an input signal to the low-pass filter 10 constituting the solenoid drive control section 9, the output of the low-pass filter 10 is as shown in FIG. 4(B). As described above, the waveform is processed into a signal that slowly rises or falls with a time constant determined by the values of the resistor and capacitor that constitute the low-pass filter 10. By inputting the waveform-processed signal to the current amplifier 11, the speed at which the iron core 80 of the solenoid 8 is displaced from the protruding state to the retracted state or from the retracted state to the protruding state can be controlled.

As described above, when the slider 3 is lowered onto the magnetic disk 5, the current value supplied to the solenoid 8 is controlled by the controller 9, and the driving speed of the flexure of the loading means is adjusted. 3 onto the magnetic disk 5 can be controlled.

Therefore, according to this embodiment, when the slider 3 is lowered onto the magnetic disk 5, by controlling the current value supplied to the solenoid 8, the speed at which the slider 3 is lowered onto the magnetic disk 5 is controlled. The slider can recover its posture under control such that the surface of the slider facing the magnetic disk is maintained in a state substantially parallel to the magnetic disk. Therefore, since the slider can fly above the magnetic disk in a stable flying posture, the slider can be loaded onto the magnetic disk without bringing the slider into contact with the magnetic disk. This prevents the slider 3 from coming into contact with the magnetic disk 5 and causing a head crash or destroying data, thereby ensuring high reliability of the magnetic disk drive device.

Furthermore, the current value supplied to the solenoid 8 is
By controlling the driving speed of the solenoid 8, the speed at which the iron core 80 of the solenoid 8 is displaced from the protruding state to the retracted state or from the retracted state to the protruding state is made low, and a large force is applied to the sliding part of the solenoid 8. Therefore, dust generated from the sliding portion of the solenoid 8 can be reduced. Therefore, dust generated from the sliding portion of the solenoid 8 does not cause a head crash and destroy data, and high reliability of the magnetic disk drive device can be ensured.

Next, in order to verify the effect of this example,
In the conventional example, current control is performed such that the current supplied to the solenoid 8 for driving the loading means for the magnetic disk of the slider is continuously increased at the start of the drive and continuously decreased before the end of the drive. The following describes test results comparing this embodiment with a magnetic disk drive device that is not equipped with a magnetic disk drive. In addition, when driving the solenoid using this embodiment, the current is continuously increased to 0.5 A 4 seconds after the start of driving the solenoid, and then the current is continuously decreased. The current supply was stopped after 7 seconds.

[0027] Test conditions were a temperature of 25°C and a relative humidity of 60%.
The slider was loaded onto and unloaded from the magnetic disk 50,000 times under the following environment. Then, during the test, dust generated from the sliding portion of the loading mechanism was measured using a dust counter. Furthermore, after the test was completed, scratches generated on the slider and the magnetic disk due to the loading/unloading operations of the slider onto the magnetic disk were observed using a microscope.

FIG. 5 shows the comparison results. FIG. 5 shows the measurement results of dust generated from the sliding portion of the loading mechanism using a dust counter when the slider was loaded and unloaded onto the magnetic disk 50,000 times. In Fig. 5, the horizontal axis is the number of loading operations, the vertical axis is the number of dust generated in one loading operation, and the plot with black circles indicates that the current supplied to the solenoid 8 to drive the loading means is continuous at the start of driving. In the case of a conventional magnetic disk drive device that does not have current control that increases the current continuously and decreases it continuously before the end of driving, the square mark plot shows the current flowing to solenoid 8 to drive the loading mechanism. This is the case of the magnetic disk drive device of this embodiment, which performs current control such that the supplied current is continuously increased at the start of driving and continuously decreased before the end of driving.

In the conventional example, current control is not performed such that the current supplied to the solenoid 8 for driving the loading mechanism is continuously increased at the start of driving and continuously decreased before the end of driving. Therefore, the speed at which the iron core 80 of the solenoid 8 is displaced from the protruding state to the retracted state or from the retracted state to the protruding state becomes faster. Therefore, the slider 3 comes into contact with the magnetic disk 5, albeit momentarily, before sufficient buoyancy is exerted on the slider 3 due to the momentum. Further, since the iron core 80 of the solenoid 8 is displaced from the protruding state to the retracted state or from the retracted state to the protruding state at a fast speed, a large force is applied to the sliding portion of the solenoid 8. Therefore, a large amount of dust is generated from the sliding portion of the solenoid 8.

In contrast, in this embodiment, the current supplied to the solenoid 8 for driving the loading mechanism is such that the current is continuously increased at the start of driving and continuously decreased before the end of driving. Because of the control, the speed at which the iron core 80 of the solenoid 8 is displaced from the protruding state to the retracted state or from the retracted state to the protruding state can be made very low. Therefore, when the slider 3 loads the magnetic disk 5, the slider 3 does not come into contact with the magnetic disk 5.

Furthermore, since the speed at which the iron core 80 of the solenoid 8 is displaced from the protruding state to the retracted state or from the retracted state to the protruding state can be made very low, no large force is applied to the sliding portion of the solenoid 8. Therefore, dust generated from the sliding portion of the solenoid 8 can be reduced. Note that if the number of dust generated from the sliding portion of the solenoid 8 is small, it can be removed by a circulation filter provided within the magnetic disk drive device.

Furthermore, after the test was completed, the slider and magnetic disk were observed under a microscope during the loading and unloading operations of the slider onto and from the magnetic disk, and as a result, no scratches were found on the slider or magnetic disk in this example. This was confirmed.

Therefore, it can be seen that this example is superior to the conventional example. As described above, by controlling the magnitude of the current supplied to the solenoid 8 and making the loading speed of the slider 3 onto the magnetic disk 5 very low, a large force is applied to the sliding part of the solenoid 8. Therefore, dust generated from the sliding portion of the solenoid 8 can be reduced, and the slider 3 can be loaded without coming into contact with the magnetic disk 5. Therefore, head crashes caused by dust and scratches on the slider 3 and magnetic disk 5 are eliminated, and the reliability of the magnetic disk drive device is improved.

Note that in this embodiment, the current control section of the slider loading mechanism is composed of a low-pass filter 10 and a current amplifier 11, but it may also be configured to use a digital-to-analog converter and be controlled by a microcomputer, for example. It would be good if it were possible to control the current so that the current supplied to drive the loading mechanism is continuously increased at the start of the drive and continuously decreased before the end of the drive. Not even. Furthermore, in this embodiment, a solenoid 8 is provided in the loading mechanism of the slider 3.
However, it goes without saying that other configurations may be used as long as the loading speed of the slider 3 onto the magnetic disk 5 can be controlled by current control.

[0035]

As described above, according to the present invention, by controlling the driving speed of the loading means to a low speed by the control section,
Dust generated from the loading means can be reduced without applying a large force to the loading means, and the attitude of the slider can be restored so that the surface of the slider facing the magnetic disk is maintained almost parallel to the magnetic disk. . Therefore, since the slider can fly above the magnetic disk in a stable flying posture, the slider can be loaded without coming into contact with the magnetic disk. Therefore, since head crashes caused by dust and scratches on the slider or magnetic disk are eliminated, the reliability of the magnetic disk drive device is improved.

[Brief explanation of the drawing]

[Fig. 1] A perspective view showing the main parts of an embodiment of the present invention.

[Figure 2] (
A) is an explanatory diagram showing the slider of the embodiment in the upper position. (B) is an explanatory diagram showing the slider of the embodiment in the intermediate position. (C) is an explanatory diagram showing the slider of the embodiment in the lower position. Explanatory diagram shown

[Figure 3] Block configuration diagram of the control unit of the embodiment

[Figure 4] (A
) is a voltage waveform diagram of the solenoid drive command input to the control unit (B) is a current waveform diagram of the current supplied to the solenoid output from the control unit

[Figure 5] Test result diagram of the number of dust generated in the conventional example and this example

[Fig. 6] A perspective view showing a conventional magnetic disk drive device.

[Explanation of symbols]

1 Flexure 2. Gimbal 3 Slider 4 Carriage arm 5 Magnetic disk 6 Load pin 7 Support arm 8 Solenoid 9 Control section 10 Low pass filter 11 Current amplifier

Claims (4)

[Claims] 1. A magnetic disk, a carriage arm that moves substantially parallel to the magnetic disk, a flexure attached to the carriage arm, a slider provided on the flexure, and a slider that moves the flexure to the magnetic disk. 1. A magnetic disk drive device comprising: a magnetic disk drive device having a loading means for bringing the slider closer to the magnetic disk, the magnetic disk drive having a control unit that lowers the flexure drive speed of the loading means by current control, thereby gently loading a slider onto the magnetic disk. drive device. 2. The magnetic disk drive device according to claim 1, wherein the control unit controls the current to be supplied to the loading means so as to continuously increase the current from the start of driving. 3. The magnetic disk drive apparatus according to claim 1, wherein the control section controls the current supplied to the loading means so as to continuously reduce the current supplied to the loading means before the end of driving. 4. The control unit controls the current so that the current supplied to the loading means is continuously increased at the start of driving and continuously decreased before the end of driving. The magnetic disk drive device described.