JPH0963220A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a head floating amt. from being changed when the pressure of air between a head slider of a floating magnetic head and a magnetic disk is changed. SOLUTION: The head floating amt. is controlled to a prescribed floating amt. in accordance with air pressure detected by a pressure sensor 15. Consequently, even when the air pressure surrounding the magnetic disk 13 in use is changed high or low, floating of the magnetic head 12 can be maintained to be the prescribed floating amt., and hence the stable write or read is performed by the magnetic head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the stability of a magnetic disk device, and more particularly to a magnetic disk device for stabilizing the flying height of a magnetic head.

[0002]

2. Description of the Related Art In recent years, the storage density of magnetic disk devices has become higher and higher, and the flying height of the magnetic head has been decreasing year by year. The support mechanism of the magnetic head is shown in FIG. The magnetic head 1 is composed of a suspension 2 having elasticity and a floating head slider 3 attached to one end of the suspension 2, and the other end of the suspension 2 is attached to a carriage arm 4 of a magnetic disk device. Head 1 is carriage arm 4
Supported by.

The head slider 3 is disposed so as to face the magnetic disk 5 moving in the X direction, has a taper portion 3a on the gas inflow end side, and has a flat portion 3b following the taper portion 3a.

On the rear end side of the flat portion 3b, that is, on the gas outflow end side, a magnetic core (not shown) of various types used for writing data to the magnetic disk 5 or reading data from the magnetic disk 5. ) Is attached.

The flying height h of the magnetic head 1 having the above-described structure is determined by the flying force acting on the head slider 3 due to the air flow generated by the magnetic disk 5 rotating relative to the head slider 3, and the suspension. It is determined by the pressing force in the direction of the magnetic disk 5 generated by the elastic force of 2.

[0006]

However, atmospheric pressure is one of the factors that determine the magnitude of the force in the levitation direction generated by the magnetic disk 5 rotating relative to the magnetic head 1. That is, when the atmospheric pressure is high, the magnetic head 1
The flying height h of the head increases, and conversely, when the atmospheric pressure decreases, the flying height h of the head decreases. There is a problem that this change in atmospheric pressure is most affected by the altitude at which the magnetic disk device is used.

Further, a mechanism portion (head disk assembly) in which the magnetic head 1 and the magnetic disk 5 are incorporated.
In a magnetic disk device having a sealed structure in which the air is completely shielded from the outside air, the magnetic head 1 and the magnetic disk 5 are mounted, although they are not directly affected by the change in atmospheric pressure due to the altitude as described above. There is a problem that the atmospheric pressure inside the sealed portion changes due to the temperature change of the gas inside the sealed portion, and as a result, the head flying height h changes as described above.

As a specific problem, when the head flying height h is less than a specified value, the head slider 3 and the magnetic disk 5 may crash, and the head flying height h is increased more than the specified value. In that case, the normal write / read operation cannot be performed, and there is a possibility that a data error may occur.

Therefore, the present invention has been made in consideration of the above circumstances, and when the pressure of the gas between the head slider and the magnetic disk of the floating type magnetic head changes, the change of the head flying height is suppressed. It is an object of the present invention to provide a magnetic disk device which is intended to prevent the occurrence.

[0010]

In order to achieve the above object, the present invention has a floating magnetic head and a magnetic disk, and writes data to or reads data from the magnetic disk by the magnetic head. In the magnetic disk device for carrying out the above, a head disk assembly on which the magnetic head, the magnetic disk, etc. are mounted, a flying height control mechanism mounted on the head disk assembly for controlling the flying height of the magnetic head, and the head disk. A magnetic disk comprising: an atmospheric pressure detecting means for detecting the atmospheric pressure in the assembly; and a control means for maintaining the flying height of the magnetic head at a predetermined flying height based on the detection output of the atmospheric pressure detecting means. On the device.

In order to achieve the above object, the present invention has a floating magnetic head and a magnetic disk, and the magnetic head writes data to the magnetic disk or reads data from the magnetic disk. In the apparatus, a head disk assembly in which the magnetic head, the magnetic disk, and the like are mounted in a sealed state in which the magnetic head and the magnetic disk are shielded from the outside air, and a flying height control mechanism mounted in the head disk assembly to control the flying height of the magnetic head A temperature detecting means disposed in the head disk assembly for detecting the temperature inside the head disk assembly; and a magnetic head for the magnetic disk for controlling the flying height control mechanism based on a detection output of the temperature detecting means. And a control means for maintaining the flying height of the vehicle at a predetermined flying height. In a magnetic disk apparatus according to symptoms.

Further, in order to achieve the above object, the present invention has a floating magnetic head and a magnetic disk, and a magnetic disk device for writing data to or reading data from the magnetic disk by the magnetic head. In the above, a head disk assembly on which the magnetic head or the magnetic disk is mounted, a flying height control mechanism mounted on the head disk assembly to control the flying height of the magnetic head, and the head disk assembly from the outside Holding means for holding with a closed closed structure, and strain detecting means for detecting the strain on the surface of the holding means, which is arranged at least at one position on the surface of the holding means,
A magnetic disk device comprising: a control means for controlling the flying height control mechanism based on the detection output of the distortion detecting means to maintain the flying height of the magnetic head above the magnetic disk at a predetermined flying height. It is in.

Further, in order to achieve the above object, the present invention is, in the magnetic disk device, arranged in either the head disk assembly or the holding means to detect the atmospheric pressure in the head disk assembly. Means for maintaining the levitation amount of the magnetic head with respect to the magnetic disk at a predetermined levitation amount based on the detection outputs of the atmospheric pressure detecting means and the strain detecting means.

According to the above construction, when the head flying height is controlled to a predetermined floating amount in accordance with the atmospheric pressure detected by the atmospheric pressure detecting means, when the atmospheric pressure around the magnetic disk changes to high or low. Even in this case, the flying height of the magnetic head can be maintained at a predetermined flying height, and stable writing or reading can be performed by the magnetic head.

Further, by controlling the flying height of the head to a predetermined floating amount in accordance with the temperature detected by the temperature detecting means, even when the temperature around the magnetic disk is changed to be high or low. The magnetic head can be levitated with a predetermined levitating amount, and stable writing or reading can be performed by the magnetic head.

Further, by controlling the flying height of the head to a predetermined floating amount in accordance with the amount of strain detected by the strain detecting means, the ambient temperature of the magnetic disk is changed to high or low, and the head disk is changed. Even when the atmospheric pressure in the assembly changes, the magnetic head can be levitated with a predetermined flying height, and stable writing or reading can be performed by the magnetic head.

Further, by controlling the flying height of the head to a predetermined floating amount in accordance with the strain amount detected by the strain detecting means and the atmospheric pressure detected by the atmospheric pressure detecting means, the environment in which the magnetic disk device is installed is considerably reduced. Even if the internal pressure of the head disk assembly mechanism does not change so much even if the external atmospheric pressure changes, the magnetic head can be levitated at a predetermined flying height. Stable writing or reading can be performed by the head.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a diagram showing a system configuration of a magnetic disk device according to a first embodiment of the present invention, and FIG. 2 is a diagram showing an example of a flying height control mechanism in the above embodiment.

FIG. 3 is a diagram showing the system configuration of the magnetic disk device according to the second embodiment of the present invention, FIG. 4 is a diagram showing the system configuration of the magnetic disk device according to the third embodiment of the present invention, and FIG. FIG. 13 is a diagram showing a system configuration of a magnetic disk device according to a fourth embodiment of the present invention.

First, a first embodiment of the present invention will be described with reference to FIG. In FIG. 1, reference numeral 10 denotes a head disk assembly (hereinafter, simply referred to as a mechanical section) in which a floating magnetic head 12 having a levitation control mechanism 11 described later, a magnetic disk 13 and the like are mounted.

The outer wall 14 which covers the magnetic head 12 and the magnetic disk 13 mounted on the mechanical unit 10 is composed of, for example, a silicon pressure sensor or the like.
An atmospheric pressure sensor 15 for detecting an atmospheric pressure of 0 is attached.

Reference numeral 20 is a magnetic head 12 or a magnetic disk 13.
Drive a personal computer (P
C) is a control unit that communicates data with an external device 30 such as a wort processor (WP).

The control unit 20 is mounted on a printed circuit board (not shown) and a sensor amplifier 21 for amplifying a detection signal output from the atmospheric pressure sensor 15, and control based on the detection signal input from the sensor amplifier 21. A microprocessor 22 that outputs a signal, and a drive circuit 23 that supplies a drive voltage based on a control signal input from the microprocessor 22 to drive the levitation control mechanism 11 to levitate the magnetic head 12 by a predetermined levitation amount. It is configured with.

The microprocessor 22 is a program for driving and controlling the arithmetic unit and the mechanical unit 10, a program showing the relationship between atmospheric pressure and the head flying height of the magnetic head 12, or a control signal and flying height output to the drive circuit 23. It has a ROM that stores a program or the like indicating the relationship of changes, and a RAM that temporarily stores data that is being calculated, etc., and is based on a detection signal input from the sensor amplifier 21 according to the program stored in the ROM. A control signal is output to the drive circuit 23 to control the mechanical section 10 and to update data by being connected to the external device 30 via an interface (not shown).

The flying control mechanism 11 of the magnetic head 12
As shown in FIG. 2, a head arm (suspension) 16 that supports the magnetic head 12 and a head arm 16
And a carriage 17 for moving the magnetic head 12 in the radial direction of the magnetic disk 13 via the.

The head arm 16 is attached to the carriage 17 via a piezoelectric element 18, and moves the magnetic head 12 in the direction of the magnetic disk 13 so as to secure a predetermined flying height between the magnetic head 12 and the magnetic disk 13. Apply a predetermined load to. Then, the atmospheric pressure changes and the head arm 1
When the mounting height H of 6 is about to change in the vertical direction, the piezoelectric element 18 is driven by the drive signal output from the drive circuit 23 of the control unit 20 to expand and contract in the vertical direction (direction of arrow A). As a result, the head flying height, which is the distance between the magnetic head 12 and the magnetic disk 13, is configured to be a predetermined flying height.

That is, the piezoelectric element 18 expands and contracts in the vertical direction (the direction of arrow A) according to the voltage supplied from the drive circuit 23, and the mounting height H of the head arm 16 corresponds to the expansion and contraction of the piezoelectric element 18. Changes in the vertical direction to offset the change in the mounting height H of the head arm 16 when the atmospheric pressure changes, and maintain the head flying height at a predetermined constant floating amount.

Further, the printed circuit board on which the mechanical section 10 in which the magnetic head 12 and the magnetic disk 13 are mounted and the control section 20 including the sensor amplifier 21, the microprocessor 22 and the drive circuit 23 is mounted is , Are held in a housing (not shown).

Next, the operation of the magnetic disk device according to the first embodiment of the present invention having the above-mentioned structure will be described. Atmospheric pressure sensor 1 arranged on the outer wall 14 of the mechanical unit 10.
The atmospheric pressure signal detected by the mechanical section 10 detected by 5 is amplified by the sensor amplifier 21 and output to the microprocessor 22.

The relationship between the atmospheric pressure and the flying height of the head and the relationship between the input to the drive circuit 23 and the change in the flying height are previously input (stored) in the ROM of the microprocessor 22, and the microprocessor 22 stores in the ROM. A control signal corresponding to the detected atmospheric pressure is output to the drive circuit 23 according to a program indicating the relationship between the atmospheric pressure and the head flying height of the magnetic head 12. The drive circuit 23 outputs a drive signal having a voltage based on the input control signal.

A drive signal having a voltage based on the input control signal is supplied from the drive circuit 23 to the piezoelectric element 18 of the levitation control mechanism 11, and the piezoelectric element 18 is deformed according to the voltage of the supplied drive signal, The mounting height H of the head arm 16 is changed.

By changing the mounting height H of the head arm 16, the head flying height of the magnetic head 12 is controlled and maintained at a predetermined flying height. For example, when the atmospheric pressure increases, the flying height of the head increases, but the atmospheric pressure sensor 1
By increasing the voltage of the drive signal supplied from the drive circuit 23 to the piezoelectric element 18 in accordance with the atmospheric pressure detected by 5, the deformation amount of the piezoelectric element 18 is increased and the magnetic head 12 is directed toward the magnetic disk 13. Direction,
The head flying height is maintained substantially at a predetermined flying height.

When the atmospheric pressure becomes low, on the contrary, the voltage of the drive signal supplied from the drive circuit 23 to the piezoelectric element 18 is reduced to displace the magnetic head 12 in the direction away from the magnetic disk 13. Thus, the head flying height is maintained substantially at a predetermined flying height.

According to the above-described first embodiment of the present invention,
By controlling the flying height of the head to a predetermined floating amount in accordance with the atmospheric pressure detected by the atmospheric pressure sensor 15, even if the atmospheric pressure around the magnetic disk 13 changes to high or low, the magnetic head 12 Can be levitated with a predetermined levitating amount, and stable writing or reading can be performed by the magnetic head 12.

Although the atmospheric pressure sensor 15 is attached to the outer wall of the mechanical section 10 in the first embodiment, the printed circuit board on which the control section 20 is mounted or the mechanical section 10 printed circuit board is held. The magnetic disk device may be attached to the housing, and the point is that it may be at a position where the atmospheric pressure of the mechanical unit 10 in the usage environment of the magnetic disk device can be detected.

Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. Second of the present invention
In the embodiment, as shown in FIG. 3, a temperature sensor 40 is installed inside a head disk assembly (hereinafter simply referred to as a mechanical section) 41 instead of the atmospheric pressure sensor 15 in the first embodiment. Unlike the mechanical unit 10 in the first embodiment, the mechanical unit 41 has a sealed structure in which the outer wall 42 of the mechanical unit 41 completely separates the internal atmosphere of the mechanical unit 41 from the outside. 41 has a structure in which no gas flows in or out.

As described above, the sealed structure in which the relatively dry gas is sealed inside the mechanical section 41 allows the humidity of the outside air to enter the mechanical section 41 and to cause dew condensation due to the temperature fixed value, so that the magnetic head 12 and the magnetic head 12 are magnetically condensed. The disk 13 does not adsorb and come into contact.

Further, in the ROM of the microprocessor 22, instead of the program showing the relationship between atmospheric pressure and the head flying height of the magnetic head 12, a program showing the relationship between temperature and the head flying height of the magnetic head 12, that is, The relationship between the temperature and the flying height of the head and the relationship between the input to the drive circuit 23 and the change in the flying height are stored in advance.

By the way, inside the mechanical section 41, a voice coil motor for driving the magnetic head 12 and a magnetic disk 13 are provided.
The air pressure may rise from that at the time of encapsulation due to heat generation due to the operation of the spindle motor that drives the motor and the temperature increase inside the mechanical unit 41 due to the temperature increase around the outside of the mechanical unit 41. On the contrary, when the temperature inside the mechanical portion 41 is lowered, the atmospheric pressure may be lower than that at the time of enclosing.

Due to the influence of the increase or decrease of the atmospheric pressure due to the increase or decrease of the temperature inside the mechanical section 41,
The flying height of the magnetic head 12 changes. In order to prevent changes in the flying height due to these effects, a temperature sensor 40 that measures the temperature inside the mechanical unit 41 is installed in the mechanical unit 41.

That is, the temperature signal detected by the temperature sensor 40 is input to the sensor amplifier 21a, amplified, and output to the microprocessor 22. In the ROM of the microprocessor 22, the relationship between the temperature and the flying height of the head and the relationship between the input to the drive circuit 23 and the change in the flying height are input (stored) in advance.

The microprocessor 22 outputs a control signal corresponding to the detected temperature to the drive circuit 23 according to the program stored in the ROM and showing the relationship between the temperature and the head flying height of the magnetic head 12. The drive circuit 23 outputs a drive signal having a voltage based on the input control signal.

A drive signal having a voltage based on the input control signal is supplied from the drive circuit 23 to the piezoelectric element 18 of the levitation control mechanism 11. The piezoelectric element 18 is deformed according to the voltage of the supplied drive signal, and changes the mounting height H of the head arm 16.

As described above, by changing the mounting height H of the head arm 16 in the same manner as in the first embodiment, the head flying height of the magnetic head 12 is controlled and maintained at a predetermined floating amount.

According to the second embodiment of the present invention described above,
By controlling the head flying height to a predetermined flying height in accordance with the temperature detected by the temperature sensor 40, even if the ambient temperature of the magnetic disk 13 changes to high or low, the magnetic head 12 Can be levitated with a predetermined levitating amount, and stable writing or reading can be performed by the magnetic head 12.

Next, a third embodiment of the present invention will be described with reference to FIG. The same parts as those in FIG. 1 or 3 are designated by the same reference numerals, and detailed description thereof will be omitted. In the third embodiment of the present invention, as shown in FIG. 4, instead of the temperature sensor 40 in the second embodiment, a strain sensor 43 is used.
Is installed on the outer wall 42 of the completely sealed mechanical unit 41.

Further, in the ROM of the microprocessor 22, instead of the program showing the relationship between the temperature and the head flying height of the magnetic head 12, a program showing the relationship between the distortion amount and the head flying height of the magnetic head 12, that is, The relationship between the distortion amount and the flying height of the head and the relationship between the input to the drive circuit 23 and the change in the flying height are stored in advance.

Reference numeral 44 is a spindle motor for rotating the magnetic disk 13, 45 is a disk retainer for pressing the magnetic disk 13 mounted on the spindle motor 44, and 46 is a base for supporting the mechanical portion 41. The flying height control mechanism 11 and the magnetic head 12 are not shown.

By the way, the completely sealed mechanical section 41 causes a pressure change when the internal gas changes in temperature,
Due to this change in atmospheric pressure, the outer wall 42 receives the force of expansion or contraction.

At this time, a large strain is generated in the relatively thin portion of the outer wall 42. By installing the strain sensor 43 on the outer wall 42 and measuring the strain generated in the outer wall 42, the change in atmospheric pressure due to the change in temperature of the mechanical portion 41 is indirectly measured.

That is, the detected strain signal of the strain sensor 43 is input to the sensor amplifier 21b, amplified, and output to the microprocessor 22. The relationship between the distortion amount and the flying height of the head and the relationship between the input to the drive circuit 23 and the change in the flying height are previously input (stored) in the ROM of the microprocessor 22, and the microprocessor 22 is stored in the ROM. A control signal corresponding to the detected strain amount is output to the drive circuit 23 according to a program showing the relationship between the strain amount and the head flying height of the magnetic head 12. The drive circuit 23 outputs a drive signal having a voltage based on the input control signal.

A drive signal having a voltage based on the input control signal is supplied from the drive circuit 23 to the piezoelectric element 18 of the levitation control mechanism 11. The piezoelectric element 18 deforms in response to the voltage of the supplied drive signal, and changes the mounting height H of the head arm 16.

As described above, by changing the mounting height H of the head arm 16 as in the first and second embodiments, the head flying height of the magnetic head 12 is controlled and maintained at a predetermined flying height. To be done.

According to the third embodiment of the present invention, the magnetic disk 1 is controlled by controlling the head flying height to a predetermined floating amount in accordance with the strain amount detected by the strain sensor 43.
Even when the ambient temperature in which 3 is used changes to high or low to change the atmospheric pressure in the mechanical portion 41, the magnetic head 12 can be levitated at a predetermined flying height. Stable writing or reading can be performed.

Next, a fourth embodiment of the present invention will be described with reference to FIG. Here, the same parts as those in FIG. 1, FIG. 3, or FIG. 4 are denoted by the same reference numerals and detailed description thereof will be omitted, and the flying height control mechanism 11, the magnetic head 12, and the magnetic disk 13 are illustrated. Is also omitted.

In the fourth embodiment of the present invention, as shown in FIG. 5, when the atmospheric pressure outside the mechanical section 41 changes significantly in the third embodiment, for example, the environment in which the magnetic disk device is installed. However, if it changes to a high altitude or low altitude,
Even if the internal temperature of the mechanical portion 41 does not change so much, the external pressure is prevented from changing and the outer wall 42 receives the force of contraction or expansion.
The same barometric sensor 15 as in the first embodiment is added to the second embodiment. Further, in the ROM of the microprocessor 22, a program showing the relationship between the atmospheric pressure and the head flying height of the magnetic head 12 is added.

That is, the strain sensor 43 and the atmospheric pressure sensor 1
The detection signals of 5 are input to and amplified by the sensor amplifier 21b and the sensor amplifier 21, respectively, and the microprocessor 2
2 is output.

At this time, the output of the strain sensor 43 input to the microprocessor 22 takes into consideration the strain due to the atmospheric pressure change corresponding to the change of the internal temperature of the mechanical unit 41 and the strain due to the external atmospheric pressure change of the mechanical unit 41. The microprocessor 22 corrects the information output from the strain sensor 43 by the atmospheric pressure signal input from the atmospheric pressure sensor 15.

The relationship between the distortion amount and the atmospheric pressure and the head flying height and the relationship between the input to the drive circuit 23 and the change in the flying height are previously input to the ROM of the microprocessor 22, and the microprocessor 22 is stored in the ROM. The control signal corresponding to the detected strain amount and atmospheric pressure is output to the drive circuit 23 according to the program showing the relationship between the strain amount and atmospheric pressure and the head flying height of the magnetic head 12. Drive circuit 23
Outputs a drive signal having a voltage based on the input control signal.

A drive signal having a voltage based on the input control signal is supplied from the drive circuit 23 to the piezoelectric element 18 of the levitation control mechanism 11. The piezoelectric element 18 deforms in response to the voltage of the supplied drive signal, and changes the mounting height H of the head arm 16.

Thus, as in the first, second, and third embodiments, by changing the mounting height H of the head arm 16, the head flying height of the magnetic head 12 is controlled to a predetermined flying height. , Maintained.

According to the above-described fourth embodiment of the present invention, the head flying height is controlled to a predetermined floating amount in accordance with the strain amount detected by the strain sensor 43 and the atmospheric pressure detected by the atmospheric pressure sensor 15. As a result, the environment in which the magnetic disk device is installed changes to a considerably high altitude or low altitude, and even if the external atmospheric pressure changes even if the internal temperature of the mechanical unit 41 does not change significantly, the magnetic head 12 floats. Can be performed with a predetermined flying height, and stable writing or reading can be performed by the magnetic head 12. It should be noted that the present invention is not limited to each of the above-described embodiments and can be variously modified without departing from the scope of the present invention.

[0063]

As described in detail above, according to the magnetic disk apparatus of the present invention, the head flying height is controlled to a predetermined floating quantity in accordance with the atmospheric pressure detected by the atmospheric pressure detecting means, so that the magnetic disk is controlled. Even if the atmospheric pressure in the surrounding area where is used changes to high or low, the flying height of the magnetic head can be maintained at a predetermined flying height, and stable writing or reading can be performed by the magnetic head.

According to the magnetic disk device of the present invention,
By controlling the flying height of the head in accordance with the temperature detected by the temperature detecting means, the flying height of the magnetic head is increased even when the ambient temperature of the magnetic disk changes to high or low. Can be performed with a predetermined flying height, and stable writing or reading can be performed by the magnetic head.

Further, according to the magnetic disk device of the present invention, the head flying height is controlled to a predetermined floating amount in accordance with the strain amount detected by the strain detecting means, whereby the ambient temperature around the magnetic disk is used. Even when the air pressure in the head disk assembly changes and the air pressure in the head disk assembly changes, the magnetic head can be levitated with a predetermined flying height, and stable writing or reading can be performed by the magnetic head. it can.

Furthermore, according to the magnetic disk device of the present invention, the head flying height is controlled to a predetermined floating amount in accordance with the strain amount detected by the strain detecting means and the atmospheric pressure detected by the atmospheric pressure detecting means. , The environment in which the magnetic disk device is installed changes to a high altitude or low altitude,
Even if the internal temperature of the head disk assembly mechanism does not change so much, even if the external atmospheric pressure changes, the magnetic head can be levitated at a predetermined flying height, and stable writing or reading by the magnetic head can be performed. It can be carried out.

[Brief description of drawings]

FIG. 1 is a diagram showing a system configuration of a magnetic disk device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a flying height control mechanism in the same embodiment.

FIG. 3 is a diagram showing a system configuration of a magnetic disk device according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a system configuration of a magnetic disk device according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a system configuration of a magnetic disk device according to a fourth embodiment of the present invention.

FIG. 6 is a diagram showing a schematic configuration of a conventional magnetic disk device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Head disk assembly, 11 ... Flying height control mechanism, 12 ... Magnetic head, 13 ... Magnetic disk, 15 ... Atmospheric pressure sensor (atmospheric pressure detection means), 20 ... Control part (control means), 41 ... Head disk assembly, 40 ... Temperature sensor (temperature detecting means), 42 ... Outer wall (holding means), 4
3 ... Strain sensor (strain detection means).

Claims (4)

[Claims] 1. A magnetic disk device comprising a floating magnetic head and a magnetic disk, wherein the magnetic head writes data to the magnetic disk or reads data from the magnetic disk, wherein at least the magnetic head and the magnetic disk are A head disk assembly to be mounted, a flying height control mechanism mounted on the head disk assembly for controlling the flying height of the magnetic head, an atmospheric pressure detecting means for detecting an atmospheric pressure in the head disk assembly, and an atmospheric pressure detecting means. And a control means for maintaining the flying height of the magnetic head at a predetermined flying height based on the detection output of the magnetic disk device. 2. A magnetic disk device comprising a floating magnetic head and a magnetic disk, wherein the magnetic head writes data to the magnetic disk or reads data from the magnetic disk, wherein at least the magnetic head and the magnetic disk are A head disk assembly mounted in an airtight state, which is shielded from the outside air, a flying height control mechanism mounted on the head disk assembly to control the flying height of the magnetic head, and the head disk assembly disposed on the head disk assembly. Temperature detecting means for detecting the internal temperature, and control means for controlling the flying height control mechanism based on the detection output of the temperature detecting means to maintain the flying height of the magnetic head above the magnetic disk at a predetermined flying height. A magnetic disk device comprising: 3. A magnetic disk device comprising a floating magnetic head and a magnetic disk, wherein the magnetic head writes data to the magnetic disk or reads data from the magnetic disk, at least the magnetic head and the magnetic disk. A head disk assembly mounted on the head disk assembly, a flying height control mechanism mounted on the head disk assembly for controlling the flying height of the magnetic head, and a holding means for holding the head disk assembly in a closed structure that is shielded from the outside air. Distortion detecting means arranged at least at one position on the surface of the holding means for detecting the distortion of the surface of the holding means, and the flying height control mechanism for controlling the flying height control mechanism based on the detection output of the distortion detecting means. Control means for maintaining the flying height of the magnetic head at a predetermined flying height. A magnetic disk device, characterized in that. 4. An atmospheric pressure detecting means for detecting the atmospheric pressure in the head disk assembly, which is provided on either the head disk assembly or the holding means, is provided, and the atmospheric pressure detecting means and the strain detecting means are used to detect the atmospheric pressure. 4. The magnetic disk drive according to claim 3, wherein the flying height of the magnetic head with respect to the magnetic disk is maintained at a predetermined flying height.