JPH052865A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To prevent a head clash without replenishing a humidifying liquid to a humidifier over a long period of time by controlling the humidity in a hermetic container to the min. required degree to the extent of averting the abnormal contact of a head slider in a floating state with a magnetic disk in consequence of the generation of static electricity. CONSTITUTION:A means 21 for detecting the contact of the magnetic disk 13 and the head slider 14, a means 22 for detecting the relative humidity in the hermetic container 11 and the humidifier 23 are provided in the hermetic container 11 housing the magnetic disk 13 mounted to a rotating mechanism, the head slider 14 mounted with the magnetic head for recording and reproducing information in a floating state to and from the magnetic disk 13 and a head positioning mechanism 17. The inside of the hermetic container 11 is humidified by the humidifier 23 when the contact of the magnetic disk 13 and the head slider 14 is detected by the above-mentioned contact detecting means 21 simultaneously when the relative humidity of the prescribed value or below is detected by the humidity detecting means 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, and more particularly to a device structure capable of preventing head crush caused by environmental humidity in a magnetic disk device of a closed structure type.

In magnetic disk devices, head sliders having magnetic heads mounted on magnetic disks have been reduced in flying height as the size and capacity of magnetic disks have increased, and as a result, head crashes due to contact between the two tend to occur. There is. Moreover, in the magnetic disk device of the closed structure type in which the container is further closed, the temperature inside the container rises during operation, and the relative humidity becomes lower than the outside air. Head crashes are more likely to occur, and there is a need for a device structure that prevents such head crashes.

[0003]

2. Description of the Related Art As shown in FIG. 5, a conventional hermetically sealed magnetic disk device has a spindle 12 rotated by a drive motor (not shown) in a hermetically sealed container 11 equipped with a filter 11a for cleaning the internal atmosphere. A magnetic disk 13 mounted on the magnetic disk 13 and a head positioning actuator 17 that supports a head slider 14 on which a magnetic head is mounted via a support spring 15 and a head arm 16 are housed. The disk is floated on the surface of the magnetic disk by the rotation and is positioned at a predetermined access position by a head positioning actuator 17, and then the magnetic head records / reproduces information in a non-contact state.

By the way, in recent years, in such a magnetic disk device, as described above, the flying distance of the head slider 14 flying above the magnetic disk 13 is as low as 0.1 to 0.3 μm as the recording density is increased. Because it has been surfaced,
Even when the head is in a floating state during operation, the head and the disk easily come into contact with each other.

Moreover, since the relative humidity inside the closed container 11 becomes lower than the outside air due to the temperature rise inside the closed container 11 during operation, static electricity is generated and electrostatic charges are generated on the surfaces of the head slider 14 and the magnetic disk 13. Dust easily adheres, and there is a high probability of contact between the head and disk through it,
In any case, there is an increasing risk that the occurrence of head crash becomes more prominent.

Therefore, in order to prevent the occurrence of a head crash due to such a decrease in relative humidity, a humidifier 18 is provided in the closed container 11 so that the inside of the closed container 11 is always at a relative humidity equivalent to an appropriate outside air humidity. The method of controlling is proposed.

[0007]

However, as described above, in order to always control the relative humidity in the closed container 11 to a relative humidity corresponding to an appropriate outside air humidity, the humidifier 18 contains a large amount of humidifying liquid. Will be required. However, the closed container
Since there is no space in which a container for storing a large amount of humidifying liquid can be placed inside 11, there is a problem that it is difficult to control and maintain the inside of the closed container 11 at a suitable relative humidity for a long period of time. .

In view of the above-mentioned conventional problems, the present invention controls the humidity in the container to the minimum necessary extent to prevent the flying head slider from abnormally contacting the magnetic disk due to the generation of static electricity, and the It is an object of the present invention to provide a novel magnetic disk device capable of preventing a head crash without replenishing a humidifying liquid to a humidifier over a period of time.

[0009]

In order to achieve the above-mentioned object, the present invention is equipped with a magnetic disk mounted on a rotating mechanism and a magnetic head for recording and reproducing information in a non-contact state with respect to the magnetic disk. In a device configuration in which the head slider and the head positioning mechanism are housed in a closed container,
A means for detecting contact between the magnetic disk and the head slider and a humidifying means for humidifying the inside of the closed container when the contact detecting means detects contact between the magnetic disk and the head slider are provided.

Further, means for detecting the relative humidity in the closed container is provided, and the relative humidity is detected by the humidity detecting means to be below a predetermined value, and at the same time, the contact detecting means makes contact between the magnetic disk and the head slider. When the is detected, the inside of the closed container is humidified by the humidifying means.

[0011]

As a result of an experiment on the relationship between the relative humidity in the closed container and the contact between the magnetic disk and the head slider, the humidity detecting means detects about 10% relative humidity in the closed container as shown in FIG. If humidification is started when the contact detection means detects contact between the magnetic disk and the head slider, the relative humidity in the closed container will rise from 10% to 50% in an extremely short time.
At the same time, the output of the contact detection means was significantly reduced and the contact between the magnetic disk and the head slider was drastically reduced.

In short, if humidification is performed when abnormal contact between the magnetic disk and the head slider is detected, the contact is eliminated. Further, since this abnormal contact hardly occurs when the relative humidity exceeds 30%, if the contact detecting means detects the contact in the humidity state of 30% or more, it is possible to invalidate it. Unnecessary humidification of the humidifier can be suppressed.

That is, the necessary minimum humidification control is possible, and head crash can be prevented without increasing the size of the humidifier and without supplying the humidifier with the humidifying liquid for a long period of time.

[0014]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an embodiment of a magnetic disk device according to the present invention, and the same parts as those in FIG. 5 are designated by the same reference numerals.

In this embodiment, as a means for detecting the contact between the magnetic disk 13 mounted on the spindle 12 and the head slider 14 on which the magnetic head is mounted as shown in FIG.
For example, an AE (acoustic emission) sensor 21 is installed on a head arm 16 on the side of an actuator 17 for head positioning that supports the head slider 14 via a support spring 15.

A humidifier 23 is arranged in the closed container 11 as shown in the figure. The humidifier 23, as shown in FIG.
A heater 32 for heating a humidifying liquid 31 made of pure water or the like contained therein is built in, and a pressure opening / closing valve 34 for opening / closing due to an increase in internal pressure is attached to the humidifying opening 33.

Next, the humidifying operation of the magnetic disk device thus constructed will be described with reference to FIG. In the present embodiment, the pressure opening / closing valve 34 provided in the humidifying opening 33 of the humidifier 23 in the closed container 11 in the operating device is a magnetic disk 13 that rotates regardless of the relative humidity inside the closed container 11 regardless of the relative humidity. The head slider 14 is closed when the AE sensor 21 does not detect abnormal contact with the head slider 14 (which does not result in a crash).

Now, the magnetic disk 13 and the head slider 14 which rotate regardless of the relative humidity inside the closed container 11
Abnormal contact with the AE sensor 21 (without crash)
If the detection signal is detected, the humidification control circuit 25 (see FIG. 3) operates the heater power supply 24 for a predetermined time (several minutes) by the detection signal to cause the heater 32 built in the humidifier 23 to generate heat to generate the humidification liquid 31. To heat.

By this heating, the humidifying liquid 31 becomes vapor and the internal air pressure rises, and the pressure opening / closing valve 34 with a spring is pushed open. As a result, the vapor flows out to humidify the inside of the closed container 11. This humidification eliminates the contact between the head slider 14 and the magnetic disk 13 as described above. The pressure opening / closing valve 34 automatically closes when the heating of the heater 32 is stopped.

In another embodiment, a closed container is further provided.
A humidity sensor 22 is installed on the inner wall of 11, and the relative humidity in the closed container 11 of 30% or less is detected by the humidity sensor 22. Then, as shown in FIG. 3, the detection signal of the humidity sensor 22 is input to the humidification control circuit 25 together with the detection signal of the AE sensor 21, and the heater drive signal is output from the humidification control circuit 25 only when both detection signals are input. Let

In this way, A can be obtained only when the relative humidity in the closed container 11 is less than 30% and abnormal contact is likely to occur.
Humidification can be performed in response to the contact detection of the E sensor 21. In other words, the AE sensor that does not induce a head crash in a state where the relative humidity is 30% or more and abnormal contact is unlikely to occur 21
Humidification due to a single detection of can be suppressed.

Therefore, by controlling the humidification to the necessary minimum, it is possible to prevent the head crash without increasing the size of the humidifier and without supplying the humidifying liquid 31 to the humidifier 23 for a long period of time.

In the above embodiment, an example in which a pressure opening / closing valve is used for the humidifying opening of the humidifier has been described. However, the electromagnetic opening / closing valve is used and the humidifying liquid in the humidifier is kept slightly small at all times. Preliminary heating allows more precise humidification control.

[0024]

As is apparent from the above description, according to the magnetic disk device of the present invention, the magnetic disk device rotating due to the generation of static electricity and the flying head slider do not come into abnormal contact with the device. The environmental humidity inside the airtight container can be controlled intermittently and to the minimum necessary, preventing head crush without increasing the size of the humidifier and without replenishing the humidifier with humidifying liquid for a long period of time. It is possible to achieve such an advantage, and the reliability is improved, resulting in an excellent effect in practical use.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram for explaining an embodiment of a magnetic disk device according to the present invention.

FIG. 2 is a sectional view of an essential part showing an embodiment of a humidifier according to the present invention.

FIG. 3 is a block diagram for explaining a humidifying operation of the magnetic disk device according to the present invention.

FIG. 4 is a diagram for explaining the humidification principle operation of the magnetic disk device according to the present invention.

FIG. 5 is a schematic configuration diagram for explaining a conventional magnetic disk device.

[Explanation of symbols] 11 airtight container 12 spindles 13 magnetic disk 14 head slider 15 Support spring 16 head arm 17 Actuator 21 AE sensor 22 Humidity sensor 23 Humidifier 24 heater power supply 25 Humidification control circuit 31 Humidifying liquid 32 heater 33 Humidification opening 34 Pressure on-off valve

Claims (2)

[Claims] 1. A magnetic disk (13) mounted on a rotating mechanism.
And a head slider (14) equipped with a magnetic head for recording and reproducing information in a non-contact state with the magnetic disk (13)
In the device configuration in which the head positioning mechanism (17) is housed in the closed container (11), means (21) for detecting the contact between the magnetic disk (13) and the head slider (14), and the contact detection means ( 21) magnetic disk (13) and head slider (14)
A magnetic disk device comprising a humidifying means for humidifying the inside of the closed container (11) when detecting contact with the magnetic disk device. 2. A means (22) for detecting a relative humidity in the closed container (11) is provided, and the humidity detecting means (22) detects a relative humidity below a predetermined value, and at the same time, the contact detecting means. (21) When the contact between the magnetic disk (13) and the head slider (14) is detected by the humidifying means, the container is closed.
The magnetic disk drive according to claim 1, wherein the inside of (11) is humidified.