JPH0724149B2 - Magnetic disk unit - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device or the like used as an external memory or the like of a computer.

2. Description of the Related Art In recent years, demands for large capacity, high density, and high speed of magnetic disk devices are remarkable.

The magnetic disk device uses a fluid lubrication technique to position a magnetic head on a magnetic medium through a minute gap and perform magnetic recording / reproduction in a non-contact manner. Since it can be rotated at high speed and accessed at high speed, it is widely used as an external memory of computers. However, since it does not come into contact with the magnetic head, it depends largely on the gap between the magnetic medium and the magnetic head, that is, the flying gap, and it is indispensable to miniaturize the flying gap in order to realize the high density. . Therefore, various technical innovations have been made in the past by making full use of fluid lubrication technology.

A conventional magnetic disk device will be described below with reference to the drawings.

FIG. 9 is a side view of a taper flat head slider of a conventional magnetic disk device.

In FIG. 9, 5 is a magnetic medium, and 10 is a head slider. A taper portion is formed at the front end of the slider surface 11 of the head slider 10 facing the magnetic medium 5, and a dynamic pressure is generated by the wedge effect of the air film accompanying the rotation A of the magnetic medium 5. In addition, the above head slider 10
A load spring 4 is in contact with the back of the head slider 10, and at the point where the load force Fw and the levitation force Fa are balanced by the dynamic pressure, the head slider 10 balances and a constant gap d is obtained.

Currently, a taper flat head slider of this type has been put to practical use with a flying clearance of 0.2 [μm] or less. Further, there has been proposed a negative pressure slider that uses a negative pressure as a load force in order to realize a smaller floating gap.

Problems to be Solved by the Invention However, the above-described configuration has the following problems.

As described above, in the conventional magnetic disk device, the flying gap of the magnetic head is naturally controlled to a fixed amount by the rigidity of the air film, but the factors that determine the characteristics of this air film are the magnetic medium and the head. The relative speed with respect to the slider, the shape of the slider surface, and the posture thereof can be mentioned. 10th
The figure shows the relationship between the levitation gap and the levitation force. 10th
In the figure, the horizontal axis is the levitation gap d, and the vertical axis is the levitation force Fa. Curve A is the flying characteristic of a slider having a certain shape. The levitation force Fa increases rapidly as the levitation gap d decreases, and the levitation gap d1 is obtained at the point where the levitation force Fa balances the load force Fw. However, if a difference in the shape of the slider surface occurs due to a processing error or the like, a difference in the flying characteristics also occurs, which causes a difference in the flying clearance. For example, considering the case where the levitation characteristic varies between the curve A and the curve B due to a processing error, even if the same load force Fw is applied, the levitation characteristic varies between the levitation gaps d1 and d2. Therefore, high-precision processing technology is currently required for forming a slider. Especially, the dependence of the flying characteristics on the slider shape is remarkable in the negative pressure type slider described above, and the poor yield is a major obstacle to practical use. In addition, the floating clearance may change. The yaw angle is an angle formed by the traveling direction of the magnetic medium and the longitudinal direction of the slider, and the flying gap tends to decrease as the yaw angle increases. When a rotary head positioner is used, the yaw angle is different between the inner circumference side and the outer circumference side of the magnetic medium, so that the flying clearance changes. Further, the relative speed between the magnetic medium and the slider on the inner peripheral side is smaller than that on the outer peripheral side, so that this angle is further increased. This places great restrictions on the structure of the head positioner and the shape of the slider surface.

Further, when mounted on an actual machine, the slider is subjected to various disturbances such as seek operation by an actuator, waviness of a magnetic medium, or vibration from the outside. Therefore, in order to suppress the fluctuation of the floating clearance, the rigidity of the air film must be increased.

Moreover, not only the air film, but also the entire system including the magnetic medium, the support mechanism, and the actuator must have high rigidity and high reliability.

As described above, in the conventional magnetic disk device, the flying characteristics greatly depend on the relative velocity between the magnetic medium and the head / slider, the shape of the slider surface and its posture, and in order to realize a desired flying clearance, High-precision processing technology and assembly technology are required, and in order to suppress fluctuations in the gap amount, high rigidity as a whole system including not only the air film but also the magnetic medium, the support mechanism and the actuator
There was a problem that high reliability was required. Due to this, there is a problem that the structure of the head positioner and the shape of the slider surface are greatly restricted, and also the miniaturization of the flying gap is restricted.

In view of the above problems, the present invention provides a magnetic disk that always realizes a desired gap amount and stably holds it regardless of the shape and posture of the slider surface, the relative speed between the magnetic medium and the head slider, and the like. Another object is to provide a magnetic disk device having a large capacity and a high density, in which the flying gap is made smaller than the conventional one.

Means for Solving the Problems In order to achieve the above object, a magnetic disk device of the present invention has a magnetic head arranged on a magnetic medium through a gap having a wavelength of visible light or less, and the magnetic medium and the magnetic head. A magnetic disk device for performing magnetic recording and reproduction by relatively moving the light source, and a light source for generating radiated light,
An evanescent wave generator that is provided in the same plane as the end surface of the magnetic head facing the magnetic medium and that converts the emitted light into an evanescent wave, and the emitted light that results from the interaction between the evanescent wave and the magnetic medium. A gap amount detection device that has a photodetector that converts a change in light amount into an electric signal, and optically quantitatively detects a gap between the magnetic head and the magnetic medium, and the magnetic head in a direction in which the gap increases or decreases. A gap direction head positioning device for positioning, and a control unit for performing position control of the gap direction head positioning device based on an output signal of the gap amount detection device.

The magnetic disk device of the present invention configured as described above is
The gap amount detecting device detects the gap amount between the magnetic medium and the magnetic head, and the controller controls the position of the gap direction head positioning device on the basis of the output signal thereof, whereby the shape of the slider surface and its posture, or Regardless of the relative speed between the magnetic medium and the head slider, etc., a desired gap amount is always realized and it is stably maintained. In addition, a smaller gap amount than before can be realized.

Embodiments The present invention provides a magnetic disk device that always realizes a desired gap amount and stably holds it regardless of the shape of the slider surface and its posture, or the relative speed between the magnetic medium and the head slider. It is an object of the present invention to provide a large-capacity, high-density magnetic disk device that realizes a smaller flying gap than the conventional one.

Further, in order to achieve the above object, it is possible to provide a small and lightweight gap amount detection device that easily detects a gap amount between a magnetic head and a magnetic medium, which has been difficult to detect in the past, with high accuracy and high resolution. It is an object.

Further, it is possible to provide a gap direction head positioning device that dynamically positions the magnetic head in order to maintain a desired amount of the gap between the magnetic head and the magnetic medium, which has been naturally determined by fluid lubrication. Has an aim.

A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a main part of a magnetic disk device according to a first embodiment of the present invention, FIG. 2 is a detailed view of part A of FIG. 1, and FIGS. 3 (a) and 3 (b) are FIG. FIG. 4 is a detailed view of a portion B of FIG. 4, and FIG.
1 to 4, 1 is a magnetic head, 5 is a magnetic medium, and 10 is a head for holding the magnetic head 1.
It is a slider. On the surface of the head slider 10 facing the magnetic medium 5, there is a dynamic pressure generating portion composed of two rails.
12 is provided, and a taper portion 12a is formed at the front end thereof. A gimbal spring 32 is attached to the back surface of the head slider 10 by means such as bonding, and is fixed to the head arm 34 by a screw 60 via a steel plate 33 having an elastic spring portion 33a. A pressing member 36 is in contact with the steel plate 33 from behind from the tip side of the elastic spring portion 33a. The pressure member 36 is fixed to the head arm 34 with a screw 60 by a suction plate 37 made of a magnetic material and having elasticity. The suction plate 37 has a solenoid 38 provided on the head arm 34.
Are facing each other with a slight gap. Solenoid 38 above
The attraction force is controlled by the applied current. The gimbal spring 32, the steel plate 33, and the head arm 34
Is referred to as a head support mechanism 31. The pressure member 36, the suction plate 37, and the solenoid 38 are referred to as a load force applying mechanism 35.
The head slider 10, the head support mechanism 31, and the load force applying mechanism 35 are collectively referred to as a gap direction head positioning device. Reference numeral 21 is a prism formed of a light-transmitting material and having a bottom surface as a gap amount detecting surface 21a, which is embedded in the head slider 10. The prism 21 has a clearance detecting surface 21
The light beam is incident at an angle that causes total reflection at the boundary between a and air. 22 LE fixed to the body
Reference numeral 23 is a light source unit composed of D and a lens, and 23 is a first light receiving element composed of a photodiode and a lens which are also fixed to the housing. Reference numeral 25a is an optical fiber for guiding the light flux from the light source unit 22 to the prism 21, and 25b is an optical fiber for guiding the light reflected by the gap amount detecting surface 21a to the first light receiving element 23. In addition, the above light source unit
The luminous flux emitted from 22 is divided into light quantities by the beam splitter, and one of them is received by the second light receiving element 24. Light receiving element from the light source unit 22 through the prism 21
A series of optical systems up to 23 and 24 is referred to as a gap amount detecting device 20. 26 is the circuit part. Reference numeral 50 is a control unit that controls the current supplied to the solenoid 38 of the load force applying mechanism 35 based on the output signal of the circuit unit 26 of the gap amount detecting device.

Regarding the first embodiment of the present invention configured as described above,
The operation will be described. As the magnetic medium 5 rotates, air flows into the dynamic pressure generating section 12 to generate dynamic pressure. The flying force Fa is applied to the head slider 10 as the sum of the dynamic pressures. Further, as described above, the load force Fw is applied from the back of the head slider 10 by the load force applying mechanism 35. At the point where the load force Fw and the flying force Fa balance each other, the head slider 10 equilibrates and the flying gap d is obtained.

Here, the principle of detecting the flying gap by the gap amount detection device 20 will be described. Now, the refractive index of the prism 21 is n1,
If the refractive index of air is n2, n1 · sin θ1 = n2 · sin θ2 known as Snell's law (1)
Is determined. However, for incident angles exceeding the critical angle sin θc = n2 / n1 formula (2), the refraction angle θ that satisfies formula (1)
The energy of light that does not exist in 2 and is incident is all reflected, and a state of so-called total reflection occurs. However, even in this case, an electromagnetic field exists in the air, and an evanescent wave that propagates along the boundary surface at a depth of about the wavelength of light is generated. Therefore, when a substance having a light absorbing property exists in the immediate vicinity of the boundary surface, total reflection no longer occurs and the reflected light is attenuated. Also in this embodiment, if the gap between the gap amount detection surface 21a and the magnetic medium 5 is about the wavelength or less, the reflected light is attenuated. FIG. 5 is a diagram showing the relationship between the floating gap d and the reflectance R of the gap amount detection surface. The parameter is the incident angle θ1. As shown in FIG. 5, the reflectance R sharply and monotonically decreases as the flying gap d decreases. This tendency becomes more remarkable as the incident angle becomes larger. Therefore, the levitation gap d can be uniquely determined by measuring the reflectance R of the gap amount detection surface at an arbitrary incident angle. The gap amount detecting device of the present embodiment measures the reflectance R of the gap amount detecting surface by the following operation. That is, the reflectance is measured by entering the light flux Io into the gap amount detection surface 21a, receiving the reflected light amount Ir, and converting the reflected light amount Ir into the electric amount Er. However, if the incident light flux Io fluctuates only by this operation, an error will occur in the measurement. Therefore, as described above, the light quantity of the luminous flux emitted from the light source unit 22 is divided into two, and Is is set to the second light receiving element 24.
The light is received by and converted into an electric quantity Es. Er for this Es
The reflectance R in an arbitrary flying gap is measured by calculating the relative amount Er / Es of. However, when the light amount division ratio is not 1: 1, the ratio between Er and Es when the flying gap d is sufficiently large and total reflection occurs is given in advance, and then the above Er / Es is divided. Let the thing be reflectance R. By performing the above operation, the reflectance in an arbitrary flying gap is measured regardless of the change in the light amount of the light source.

Next, the operation of keeping the floating gap constant will be described.
It is assumed that the floating clearance d measured by the clearance detection device 20 is larger than the desired floating clearance d0. In that case, the load force Fw generated by the load applying mechanism 35 is increased. Then, until the levitation force Fa becomes equal to the load force Fw,
The slider 10 moves in the direction in which the gap becomes smaller. On the contrary, when the measured flying gap d is smaller than the desired flying gap d0, the head slider 10 has a large gap until the flying force Fa becomes equal to the loading force Fw by decreasing the loading force Fw. Move in the direction. Therefore, by constantly repeating the above operation, the floating clearance becomes the desired amount d0 and is further maintained. That is, the floating clearance is controlled by controlling the load force with respect to the unknown and changing floating force.

Further, in this embodiment, a highly rigid air film is realized and the magnetic head is stably positioned by the following operations. As described above, in this embodiment, the load force can be increased or decreased. Therefore, an air film having higher rigidity than the conventional one is realized by holding down the head slider 10 that generates a flying force sufficiently larger than the conventional one with a large load force commensurate with it. Further, at the time of starting / stopping, the voltage applied to the solenoid 38 is cut off to eliminate the load force, thereby significantly reducing wear.

The effects of the first embodiment of the present invention will be described below.

As described above, in this embodiment, the gap amount between the magnetic medium and the magnetic head is detected by the gap amount detection device, and the control unit controls the gap direction head positioning device based on the output signal, thereby The desired gap amount can be always realized and held regardless of the relative speed between the head slider and the head slider, the shape of the slider surface, and the posture thereof. This widens the margin for processing and assembling each component, and gives the degree of freedom to the shape of the slider surface or the configuration of the head positioner. Further, since a highly rigid air film can be formed, the followability is good and the stability against disturbance is also high.

Further, according to the gap amount detecting device having the above-described configuration, the gap amount between the magnetic head and the magnetic medium can be easily detected with high accuracy and high resolution. That is, since the floating gap can be uniquely determined with respect to the reflectance, the operation of counting the fringe orders unlike the conventional optical interferometry is not necessary. Further, compared with the optical interferometry, the amount of change in reflectance is large, the sensitivity is high, and the range of measurement error is small. Therefore, it is possible to realize high-precision and high-resolution measurement with a simple configuration. Moreover, by setting the incident angle appropriately,
It is possible to cope with extremely small gaps to gaps of a relatively large wavelength, and it is possible to employ it in magnetic disk devices of all specifications.

Also, by using an optical fiber as a means for guiding the light flux from the light source to the gap amount detection surface and a means for guiding the reflected light to the light receiving element, it is possible to fix the light source, the light receiving element, the circuit part, etc. to the housing and move it. The part weight can be reduced. Since the setting of the incident angle / reflection point is determined only by the attachment of the optical fiber, even if there is surface wobbling or vibration, the error due to the fluctuation of the incident angle / reflection point does not occur, and the accuracy is always high. Measurement can be realized.

Further, by taking the relative output of the first light receiving element and the second light receiving element, regardless of the change in the light amount of the light source,
It is possible to measure the gap amount in an arbitrary floating gap with high accuracy at all times.

Further, according to the gap direction head positioning device having the above-described configuration, the gap amount between the magnetic head and the magnetic medium, which has been conventionally determined by the fluid lubrication action, can be easily changed only by adjusting the applied voltage. It is possible. In addition, the ability to increase or decrease the load force also has the following effects. That is, as described above, the high load force is applied during rotation to form a highly rigid air film, and the load force is interrupted during start / stop, whereby wear can be significantly reduced. Further, the contact start / stop can be avoided by setting the position of the head slider away from the magnetic medium in the neutral state where no load is applied to the head support mechanism.

In this example, an LED was used as the light source,
Other light emitting elements such as a semiconductor laser may be used. Although the photodiode is used as a means for receiving the reflected light and converting it into an electric quantity, other photoelectric elements such as a photo transistor may be used.

A second embodiment of the present invention will be described below with reference to the drawings. FIG. 6 is a side view showing a gap amount detecting device and a gap direction head positioning device of a magnetic disk device according to a second embodiment of the present invention. In the sixth,
1 is a magnetic head. Reference numeral 20 is a gap amount detecting device including the magnetic head 1. 7 (a) and 7 (b) are the sixth
FIG. 3 is a detailed view of a gap amount detection device 20 in the figure. In FIG. 7, reference numeral 21a is a clearance amount detecting surface, and 25a and 25b are optical fibers for guiding the light flux from the outside to the clearance amount detecting surface 21a and guiding the reflected light to the outside. The components before the optical fiber 25a and the components after the optical fiber 25b are the same as those in the first embodiment described above, and are omitted here. Next, a method for manufacturing this gap amount detecting device will be described below.

(1) First step: the magnetic head 1 and the optical fiber 25
A and 25b are insert-molded with thermoplastic transparent resin to form a rough shape of the gap amount detection surface.

(2) Second step: Polishing is performed so that the head gap of the magnetic head 1 in the molded product is exposed to finish the gap amount detecting surface 21a.

The magnetic head 1 and the optical fibers 25a and 25b are always kept in a fixed positional relationship by the precision of the mold. The gap amount detecting device 20 manufactured through the above steps is bonded to one end of the electrostrictive element 40 via the L-shaped holding member 29. The other end of the electrostrictive element 40 is bonded to the head slider 10. The electrostrictive element 40 is composed of zircon / lead titanate and positive and negative electrodes provided at both ends thereof, and the direction of the electric field is set parallel to the gap amount detection surface 21a. The head slider 10 has two rails sandwiching the magnetic head or the like, and a dynamic pressure generating portion is formed on the slider surface 11 facing the magnetic medium 5, respectively.
The head slider 10 is supported by a head support mechanism (not shown) including a gimbal spring and a leaf spring, as in the first embodiment. The flying force of the slider surface 11 is balanced with the load force of the head support mechanism to obtain a flying gap of about 1 [μm] during steady rotation.
In the above configuration, the portion excluding the gap amount detection device 20 is generically referred to as a gap direction head positioning device.

The operation of the second embodiment of the present invention configured as above will be described.

The operation of the gap amount detecting device 20 in this embodiment is exactly the same as that of the gap amount detecting device in the first embodiment described above, and therefore its explanation is omitted. Next, the operation of the gap direction head positioning device will be described. The head slider 10 substantially follows the magnetic medium 5 while flying with a gap of about 1 [μm] due to the fluid lubrication effect. In this state, a voltage is applied to the electrodes of the electrostrictive element 40. Then, the electrostrictive element 40 expands and contracts in the direction in which the gap increases and decreases due to the piezoelectric lateral effect. Therefore, the gap amount detecting device 20 including the magnetic head 1 attached to one end of the electrostrictive element 40 is displaced in the gap direction. Since the amount of expansion / contraction of the electrostrictive element 40 is determined by the electric field, the gap between the magnetic head 1 and the magnetic medium 5 can be adjusted by adjusting the voltage applied to the electrodes. Further, when the power is not supplied, the gap amount detecting surface 21a and the slider surface 11 are on the same plane, or the former is set to be separated from the magnetic medium 5, so that the start / stop is performed. At this time, the gap amount detecting surface 21a is prevented from coming into contact with the magnetic medium 5.

The gap amount detecting device 20 and the gap direction head positioning device of this embodiment configured as described above have the same effects as those of the first embodiment. Further, as in the first embodiment, a control unit is provided, and the electrostrictive element 40 is generated based on the output signal of the gap amount detecting device 20.
By controlling the voltage applied to the magnetic disk device, it is possible to configure a magnetic disk device that always realizes a desired gap amount and stably holds it.

Particularly, according to the present embodiment, it is possible to realize a magnetic disk device in which the gap amount is made smaller than in the conventional case. Conventionally, with respect to the reduction of the gap amount, the processing / assembly accuracy or the risk of head crash has been a major obstacle, but according to the present embodiment, these restrictions should be greatly relaxed for the following reasons. You can First, the head slider has a role of approximately following large displacements such as waviness of the magnetic medium, and the slider surface is levitated with a sufficiently large clearance so as not to cause a crash. One is that the area very close to the magnetic medium is a small area of the head gap and the gap detection surface, and the gap in that portion is always detected. Further, the response of the electrostrictive element 40 is as long as several hundreds of kHz, and the followability is very high as compared with the head slider. Therefore, even if there is a peculiar point on the magnetic medium, it is possible to follow with high precision while maintaining a very small gap without causing a crash. It is also clear that, as in the first embodiment, the margin for processing / assembling precision is wide. Thus, in this embodiment,
There is an effect that it is possible to realize a high-density and large-capacity magnetic disk device in which the gap amount is made smaller than in the conventional case.

Further, in this embodiment, the conventional winding type magnetic head is used, but a thin film head may be used. In this case, the thin film head can be formed on the transparent member of the gap amount detecting device as a substrate. Further, when the thin film head is used, the mass of the movable portion is reduced, so that the effect of the present invention is further enhanced.

Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a perspective view showing a gap amount detecting device and a gap direction head positioning device of a magnetic disk device according to a third embodiment of the present invention. In FIG. 8, 1
Is a magnetic head, and 20 is a gap amount detecting device, both of which are embedded in the head slider 10. Gap amount detection device
The configuration and operation of 20 are exactly the same as those of the first embodiment described above, and therefore description thereof is omitted here. Above head slider
The slider surface 10 has a U-shaped positive pressure generating portion 13 composed of two rails 13a and 13b on the left and right and a connecting surface 13c that connects them on the inflow side, and a negative pressure having a step of only a few μm. It is composed of part 18. The negative pressure generating portion 18 is formed of zircon lead titanate which is an electrostrictive material,
Positive and negative electrodes are provided on both ends thereof. The slider surface is formed by the following method. First, the electrode is bonded to the rough-processed zircon / lead titanate, and the bottom surface only is bonded to the slider body. Next, a voltage is applied to the electrodes to cause a piezoelectric transverse effect in zircon / lead titanate. In that state, surface finishing is performed so that the slider surface becomes one flat surface. If the applied voltage is turned off after that, the positive pressure generator 13
A negative pressure generating portion 18 having a slight step is formed. In the above configuration, the portion excluding the gap amount detecting device 20 is generically called a gap direction head positioning device.

The operation of the gap direction head positioning device of the third embodiment of the present invention configured as described above will be described. Along with the rotation of the magnetic medium, a positive dynamic pressure is generated in the positive pressure generating section 13 and a flying force is applied to the slider 10. Further, since the negative pressure generating section 18 has a step between the negative pressure generating section 18 and the positive pressure generating section 13, a negative dynamic pressure is generated and a suction force is applied to the slider 10.

The slider is positioned with a constant gap amount in which the floating force and the suction force are balanced. Further, the magnitude of the negative dynamic pressure is changed by adjusting the voltage applied to the zircon / lead titanate of the negative pressure generating section 18 to change the step amount. . Therefore, the gap amount that balances the levitation force changes, and the magnetic head 1 is positioned with respect to the magnetic medium.

As described above, according to the gap direction head positioning device of the present embodiment, the gap amount between the magnetic head and the magnetic medium, which was conventionally determined by the fluid lubrication action, can be easily changed by adjusting the applied voltage. Can be made.

Further, similarly to the first embodiment, the gap amount detecting device of the present embodiment
20 and gap direction head positioning device and control unit combined,
By controlling the voltage applied to the negative pressure generating unit 18 based on the output signal of the gap amount detection device 20, a magnetic disk device that always realizes a desired gap amount and stably holds it. You can In particular, according to the present embodiment, the precision with respect to processing can be greatly relaxed, so that the negative pressure type slider can be put to practical use.

Further, in this embodiment, the negative pressure generating portion is formed of the electrostrictive material, but it may be provided in the positive pressure generating portion, and in that case, the levitation force itself can be controlled. Also, by providing electrostrictive material on the slider surface at multiple locations,
The attitude of the head slider can also be controlled.

In the first to third embodiments described above, a so-called hard disk device using a rigid magnetic medium was used, but the present invention is a magnetic disk device using a flexible magnetic medium. It is also applicable to.

EFFECTS OF THE INVENTION As described above, the present invention provides a magnetic disk device for magnetic recording / reproducing by arranging a magnetic head with respect to a magnetic medium through a minute gap and by relatively moving the magnetic medium and the magnetic head. And a gap amount detecting device for quantitatively detecting a gap between the magnetic head and the magnetic medium, a gap direction head positioning device for positioning the magnetic head in a direction in which the gap increases or decreases, and the gap amount detecting device. By providing with a control unit that controls the position of the gap direction head positioning device based on the output signal of the device,
It is possible to realize a magnetic disk device that always realizes a desired gap amount and stably holds it regardless of the shape and posture of the slider surface, the relative speed between the magnetic medium and the head slider. Therefore, the accuracy of processing / assembling each component can be significantly eased. Further, it is possible to give flexibility to the structure of the head positioner and the shape of the slider surface. Further, there is an effect that it is possible to realize a large-capacity / high-density magnetic disk device in which the flying gap is made smaller than in the past.

[Brief description of drawings]

1 is a perspective view of a main part of a magnetic disk device according to a first embodiment of the present invention, FIG. 2 is a detailed view of part A of FIG. 1, and FIG.
FIG. 4 is a detailed view of part B in FIG. 1, FIG. 4 is a conceptual view of the operation of the magnetic disk device in the first embodiment, and FIG.
And FIG. 6 is a side view showing a gap amount detection device and a gap direction head positioning device of a magnetic disk device according to a second embodiment of the present invention. FIG. 7 is a detailed view of the gap amount detecting device in FIG. 6, and FIG. 8 is a perspective view showing a gap amount detecting device and a gap direction head positioning device of a magnetic disk device according to a third embodiment of the present invention. FIG. 9 is a side view of a taper flat head slider of a conventional magnetic disk device, and FIG. 10 is a diagram showing the relationship between the flying gap and the flying force. 1 ... Magnetic head, 5 ... Magnetic medium, 10 ... Head slider, 20 ... Gap amount detecting device, 35 ... Load force applying mechanism, 50 ... Control unit.

Claims (5)

[Claims] 1. A magnetic disk device for performing magnetic recording and reproduction by arranging a magnetic head with respect to a magnetic medium through a gap having a wavelength of visible light or less and moving the magnetic medium and the magnetic head relative to each other. A light source that emits radiated light, an evanescent wave generator that is provided in the same plane as an end surface of the magnetic head that faces the magnetic medium, and that converts the radiated light into an evanescent wave, the evanescent wave and the magnetic medium, A gap detector for optically quantitatively detecting a gap between the magnetic head and the magnetic medium, and a photodetector for converting a change in the amount of emitted light resulting from the interaction of The gap direction head positioning device for positioning the head in the direction in which the gap increases and decreases, and the gap direction head position based on the output signal of the gap amount detection device. Magnetic disk apparatus characterized by comprising a control unit for controlling the position of the fit device. 2. An evanescent wave generator is provided with a reflection surface made of a light-transmissive material provided in the same plane as an end surface of a magnetic head facing a magnetic medium, and a reflection surface from a light source for causing internal reflection on the reflection surface. It is provided with a means for injecting radiated light and a means for injecting the reflected light from the reflecting surface into a photodetector, and the incident angle to the reflecting surface is set to be a critical angle or more. The magnetic disk device according to claim 1. 3. A gap-direction head positioning device includes a magnetic member provided on a movable body having a magnetic head, and a solenoid fixed to the outside of the movable body and magnetically coupled to the magnetic member via a gap. Claim 1 characterized by the above.
The magnetic disk device described. 4. A gap-direction head positioning device includes a head slider positioned at a predetermined gap with respect to a magnetic medium by fluid lubrication, and a magnetic head displacement mechanism for displacing the magnetic head with respect to the head slider in the gap direction. The magnetic disk drive according to claim 1, further comprising: 5. A gap-direction head positioning device includes a head slider for supporting a magnetic head, and a whole or a part of a surface of the head slider facing the magnetic medium is made of a material which is deformed in response to an external signal. The magnetic disk drive according to claim 1, wherein the magnetic disk drive is formed.