JPH03266285A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To eliminate fault occurrence owing to static electricity at the working of a device in the atmosphere of low humidity by providing water absorbing resin in a volume variable container to contract according to the increase and decrease of air pressure within the device. CONSTITUTION:A volume variable container 3 which is expandable and contractible and is a sealed type at the outer side of a filter 2 provided at the basket body of a magnetic disk device 1 and water absorbing resin 4 is fixed in it. The high water absorbing resin without the degradation of properties used for a paper diaper and so on for instance is satisfied as the moisture absorbing resin 4 and is set in the volume variable container 3 in a condition in which the resin is water-absorbed to a certain extent in advance and humidity within the device is kept constant. Thus, a dust-proof countermeasure and a countermeasure for static electricity occurred owing to humidity lowering within the device can be obtained.

Description

[Detailed Description of the Invention] (Summary) The purpose of the present invention is to provide a magnetic disk device (1) equipped with a dust-proof filter (2) for the purpose of improving the dust-proofing function and eliminating electrostatic interference with respect to magnetic disk devices.
) is provided with a variable volume container (3) that expands and contracts according to changes in the atmospheric pressure inside the device on the outside of the filter (2), and a water-absorbing resin (4) is installed in the container (3). [Field of Industrial Application] The present invention relates to a magnetic disk drive which has enhanced dustproof function and eliminates electrostatic interference.

A magnetic disk is a recording medium made of a magnetic material such as iron sesquioxide (γ-FezOz) or barium ferrite (BaO-FezOz, commonly known as Ba ferrite) formed on a disk made of a non-magnetic metal such as an aluminum alloy. It is something.

In addition, magnetic disk drives hold a magnetic head with a small gap above a magnetic disk that is rotated at high speed by a motor, convert electrical signals into magnetic signals, and record information on a large number of concentric tracks. It is also a device that converts magnetic information recorded on a track into an electrical signal using a magnetic head and retrieves it.

This device has a structure in which a large number of magnetic disks equipped with magnetic heads are stacked on a rotating shaft, so it can have a large recording capacity and is used as a main model of peripheral recording devices for computers.

[Conventional technology]

In a magnetic disk drive, the magnetic head moves over the magnetic disk at a speed of 0.15-0.
Information is recorded and reproduced by floating in the air with a minute gap of 30 μm.

In this state, if dust enters the gap, the flying balance of the magnetic head will be lost and the head will fall, causing a head crash and causing the recorded information on the magnetic disk to disappear in an instant.

To prevent this, in magnetic disk drives, the magnetic head and magnetic disk are integrated and have a sealed structure to prevent dust from entering from the outside.

However, when the equipment is operated, the temperature inside the equipment rises and the air expands, so with a completely sealed structure, air leakage occurs due to the weak sealing of the equipment, and when the equipment stops, the temperature rises. There is a problem in that as the device descends, outside air is sucked in from the same location, causing dust to enter the device.

In order to avoid this, magnetic disk drives are provided with ventilation holes equipped with filters so that the air within the drive can expand and contract without intrusion of dust.

However, maintenance and replacement of filters is troublesome.

Next, errors may occur in magnetic disk drives due to static electricity during winter.

The reason for this is that the humidity tends to drop in the winter, and therefore the inside of the equipment is also in a low humidity state, but as the temperature rises due to operation, the humidity inside the equipment further decreases, so the relative humidity is 5%.
In some cases, static electricity is likely to occur.

Then, for example, discharge occurs between the magnetic disk and the magnetic head, which causes noise errors.

However, since such failures do not occur frequently, no proactive countermeasures have been taken so far.

[Problem to be solved by the invention]

As mentioned above, magnetic disk drives require dust-proofing measures and countermeasures against static electricity caused by a drop in humidity inside the device.
The former uses a filter to prevent dust from entering, but maintenance is troublesome, and no special measures have been taken for the latter.

Therefore, we took measures to prevent dust and reduce the humidity inside the equipment to 30%, which is easy to maintain.
There has been a demand for an apparatus configuration that can maintain R) at around I.

[Means to solve the problem]

The above problem can be solved by installing a variable volume container outside the filter of a magnetic disk device equipped with a dustproof filter, which expands and contracts according to changes in the atmospheric pressure inside the device, and placing a water-absorbing resin inside this container. This problem can be solved by configuring a magnetic disk device with this feature.

[Effect]

As shown in FIG. 1, the present invention provides a retractable and sealed variable volume container 3 outside a filter 2 provided in the casing of a magnetic disk drive II, and a water-absorbing resin 4 is fixed in the container. It is something.

In FIG. 1, an accordion-shaped container 3 is shown as the variable volume container 3, but a bag-shaped container may also be used.

Next, the hygroscopic resin 4 may be a highly water-absorbing resin that does not deteriorate its properties and is used, for example, in disposable diapers, and in the present invention, it is set in the variable volume container 3 in advance in a state where it absorbs water to a certain extent. and keep the humidity inside the device at about 30% RH.

Figure 3 shows an example of the moisture absorption and moisture release characteristics of a water-absorbing resin.
1, Mitsubishi Yuka ■) was used.

In other words, if this material is left at 40°C and 990% RH to absorb sufficient moisture, the moisture absorption rate will be 80% by weight, but if this material is left in an atmosphere of 40°C and 50% RH, it will absorb moisture as shown in the figure. The moisture absorption rate decreases to 2% after 24 hours.

Next, when this material is transferred to an atmosphere of 40'C and 90% R1, the moisture absorption rate increases as shown in the figure and returns to 80% by weight after about 24 hours.

The present invention uses such a water-absorbing resin.

Further, when the temperature inside the device rises during use, and the pressure inside the device rises as a result, the variable volume container 3 expands, and
By deflating when the device is stopped, the air pressure inside the device can be kept constant.

However, the device to which the present invention is applied has the first 5%.
The humidity will decrease for a while, but it will soon recover and maintain a value of about 30% R1.

Furthermore, since it has a sealed structure, dust will not be inhaled.

[Example] An accordion-shaped plastic bag was used as a variable volume container, and was attached closely to the filter of a magnetic disk device.

Then, 100 g of pure water was absorbed and fixed in Prawet (No. G260H, Mitsubishi Yuka ■) Ig as a water-absorbing resin.

Then, the magnetic disk drive was installed at a temperature of 20°C and a humidity of 40%.
The apparatus was placed in an RH atmosphere and operated.

FIG. 2 shows changes in temperature and humidity inside the device, and for reference, also shows the case where the device is applied to a conventional structure without a variable volume container.

In other words, the temperature inside the device gradually increases due to operation, and
When the temperature exceeds 0"C, the humidity inside the device is about 1 [Effect of the invention] By implementing the present invention, which includes a water-absorbing resin in a variable volume container that contracts as the atmospheric pressure inside the device increases or decreases, low humidity can be achieved. Even if the device is operated in an atmosphere of

[Brief explanation of drawings]

Fig. 1 is a partial cross-sectional view of a magnetic disk device equipped with a variable volume container according to the present invention, Fig. 2 is a diagram of changes in temperature and humidity within the device over time, and Fig. 3 is a diagram showing environmental dependence of moisture absorption rate of water-absorbing resin. This is a diagram showing the nature of In the figure, 1 is a magnetic disk device, and 3 is a variable volume container. 2 is a filter, 4 is a water-absorbing resin,

Claims (1)

[Claims] A magnetic disk device (1) equipped with a dustproof filter (2)
) is provided with a variable volume container (3) that expands and contracts according to changes in the atmospheric pressure inside the device on the outside of the filter (2), and a water-absorbing resin (4) is installed in the container (3). A magnetic disk device characterized by: