JPS6396722A - Floating type magnetic head - Google Patents

Abstract

PURPOSE:To improve an electromagnetic transform characteristic, and to stabilize magnetic recording with high density, by constituting a floating slider plane with plural plane parts, and one ore more curved plane parts, and providing a magnetic flux gap part at a position making a minimum distance between the projecting part of the floating slider part and a magnetic recording medium. CONSTITUTION:The floating slider part 2 of a magnetic head 1 is formed with two planes intersecting mutually, and at the front of the part, an air flow terminal 4 is formed. And the magnetic flux gap part 3 of the magnetic head 1 is provided on the cross line of two floating slider planes 2 including a point P2, is provided. Thereby, it is possible to make only the magnetic flux gap part 3 approach to a magnetic disk 8 that is the magnetic recording medium, and to expand the distance between the floating slider plane 2 and the magnetic disk 8 comparatively, and an air layer passing the slider floating plane 2 is thickened, and it is possible to obtain a stable floating characteristic from the standpoint of aerodynamics. In this way, it is possible to obtain the magnetic head with few frequency of head crash due to contact with the magnetic disk, and to attain the magnetic recording with high reliability and high density.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic head used in a magnetic recording device,
In particular, it is easy to reduce the gap between the magnetic flux gap of the magnetic head and the magnetic recording medium, and has a flying slider surface that allows the magnetic head to fly stably. The present invention relates to a floating magnetic head suitable for recording.

[Conventional technology]

As a magnetic head used in a magnetic drum or magnetic disk recording device used as an external recording device of a conventional computer, for example, Japanese Patent Application Laid-Open No. 60-10178
There are some proposals in Japanese Patent Application Laid-Open No. 136004/1984 and Japanese Patent Application Laid-open No. 131684/1984. Although there are some differences in the structure of each,
This is a type in which the flying slider surface of the magnetic head and the magnetic flux gap are located on the same plane. In a magnetic head with this structure, the distance between the magnetic flux gap and the magnetic recording medium is reduced.

In order to improve the magnetic recording density, a difficult technical problem arises in that the flying height of the entire magnetic head must be reduced. That is, as shown in Figure 7,
A pair of slide rails 11 forming a flying slider surface 2 are provided on one side of the magnetic head 1 . This slide rail 11
An air inflow taper section 6 is provided in the section for introducing an air flow 10 from the direction of the arrow to produce a dynamic pressure effect. A surface formed by a pair of planes between the air inflow end 4 and the air outflow end 5 of the slide rail 11 is referred to as a floating slider surface 2. A magnetic core part 1 has a coil 13 wound around the central air outflow end 5 side of the magnetic head 1, through which a signal current for recording and reproduction flows.
2, and has a structure having a magnetic flux gap portion 3 via a magnetic flux gap glass 14. Figure 8(a) shows the above seventh
2 shows a floating state of the conventional magnetic head 1 shown in the figure with respect to a magnetic recording medium. FIG. 8(b) is a view of the magnetic head 1 shown in FIG. 8(a) in the direction of arrow A, and FIG.
) are shown respectively. A magnetic disk 8, which is a magnetic recording medium, is rotating at high speed in the direction of an arrow 9. magnetic head 1
is attached to a magnetic head moving mechanism (not shown) by a support spring and an arm. If the distance between the air inflow end 4 of the flying slider surface 2 formed by the pair of slide rails 11 of the magnetic head 1 and the magnetic disk 78 is ht+the distance between the air outflow end 5 and the magnetic disk 8 is h, then 9Usually h1 The magnetic head 1 flies so that the relationship ≧h holds.

Therefore, the minimum distance between the magnetic head 1 and the magnetic disk 8 is h. On the other hand, the magnetic flux gap portion 3 is connected to the floating slider surface 2.
Since it is provided near the air outflow end 5 in the same plane as
It is. In order to improve the magnetic recording density by reducing the distance between the magnetic flux gap portion 3 and the magnetic disk 8, the flying height of the entire magnetic head 1, which has a wide flying slider surface 2 in the same plane, can be extremely increased. Must be kept low.

This is an extremely difficult problem technically since the amount of air flowing into the floating slider 2 is small and the air layer is very thin. In addition, in this type of conventional magnetic head, the flying of the magnetic head tends to become unstable due to the interlocking of dust in the air passing through the gap between the magnetic head and the magnetic recording medium, and therefore the flying of the magnetic head tends to become unstable. The edge of the slider surface frequently comes into contact with the magnetic recording medium, resulting in a so-called head crash phenomenon, which demagnetizes or damages the magnetic recording medium, resulting in a reduction in the performance and reliability of high-density magnetic recording. .

On the other hand, JP-A-51-1442, which is the same applicant as the present invention.
In Publication No. 1.8, a part of the core with a magnetic flux gap portion is made to protrude from the flying slider surface of a floating magnetic head,
A high-performance and highly reliable floating magnetic head has been proposed that has a relatively low frequency of head crashes and can reduce the gap between the m-flux gap and the magnetic recording medium. It is extremely difficult to machine a pair of floating slider surfaces with a gap between them with good surface accuracy without damaging the magnetic flux gap.
Therefore, it has not been possible to mass produce heads that meet the purpose, and it has not been possible to fully satisfy highly reliable high-density magnetic recording.

[Problem that the invention seeks to solve]

As mentioned above, in the conventional floating magnetic head in which the magnetic flux gap and the slider air bearing surface are in the same plane,
If an attempt is made to increase the recording density by reducing the distance between the magnetic flux gap and the magnetic recording medium, a difficult technical problem arises in that the flying height of the entire magnetic head must be lowered. Namely.

The flying height of magnetic heads used in magnetic disk drives, etc., is currently about 0.3-1, but in the future it will increase from about 0.3 to 0.1 in order to improve electromagnetic conversion characteristics and achieve high-density recording.
It is said that it is necessary to keep it below 7M (Nikkei Electronics, September 23, 1985).

P183-P199) In principle, the mean free path of gas molecules (in the case of air, 0.067 J at 1 atmosphere) is possible. However, since the thickness of the air layer flowing into the flying slider surface is thin and very small, reducing the overall flying height of this magnetic head is extremely difficult in practice and requires tremendous technical effort. The problem arises that it must be done. In addition, in the above-mentioned floating magnetic head where the magnetic flux gap and the flying slider surface are in the same plane, the flying stability of the magnetic head is extremely poor, so the end of the flying slider surface of the magnetic head touches the magnetic recording medium. Frequent contact causes head crashes, severely damaging the magnetic recording medium, and reducing the performance and reliability of high-density magnetic recording.

On the other hand, in conventional floating magnetic heads, a part of the core with a magnetic flux gap protrudes beyond the coplanar flying slider surface to reduce the distance to the magnetic recording medium and achieve high-density recording. It is extremely difficult to process a set of flying slider surfaces, which require high surface accuracy, into a structure in which only the magnetic flux gap protrudes from the center while keeping them on the same plane.

An object of the present invention is to eliminate the drawbacks or problems of the prior art described above, to reduce the gap between the magnetic flux gap portion and the magnetic recording medium while keeping the flying height of the magnetic head at a high flying height, and to reduce the gap between the magnetic flux gap and the magnetic recording medium. Provides a floating magnetic head that has a flying slider surface that allows the head to fly stably, has an extremely low probability of head crashes, has excellent electromagnetic conversion characteristics, is suitable for high-density magnetic recording, and is easy to manufacture. It's about doing.

[Means for solving problems]

The present invention provides a floating magnetic head that includes a magnetic flux gap section that performs magnetic recording and reproduction by electromagnetic conversion, and has a flying slider surface that is floated by an air flow generated by movement or rotation of a magnetic recording medium. A protrusion that gently protrudes toward the magnetic recording medium is formed in a substantially vertical plane that includes a center line that extends in the flow direction of the air flow, centering on the magnetic flux gap.

The flying slider surface is configured by two or more plural flat parts or one or more curved parts so that the distance between the protrusion part of the flying slider surface and the magnetic recording medium is almost minimized when the magnetic head is flying. One of the objects of the present invention can be achieved by providing the magnetic flux gap portion at a suitable position.

[Effect]

In the floating magnetic head of the present invention, the magnetic flux gap portion is provided on the protrusion of the floating slider surface formed by a plurality of planes or curved surfaces, and the magnetic flux gap portion is provided at the position closest to the magnetic recording medium side. Since the slider surface is kept at a relatively large distance from the magnetic recording medium, a large amount of air flows in, and a stable flying blade of the appropriate size is obtained for the magnetic head. Since the distance between the magnetic flux gap and the magnetic recording medium can be controlled to be extremely small, electromagnetic conversion characteristics can be significantly improved and stable high-density magnetic recording can be achieved.

Furthermore, the flying slider surface of the floating magnetic head of the present invention is
Since the distance from the magnetic recording medium is large, this structure provides a large floating blade that is also aerodynamically stable. A conventional magnetic head in which the flying slider surface and the magnetic flux gap part are on the same plane can be modified to extend the core part with the magnetic flux gap part to the downstream side, or a magnetic head can be created in which only the magnetic flux gap part sharply protrudes. In comparison, the flying characteristics of the magnetic head are extremely stable, there is no concentration of stress due to contact with the magnetic recording medium, and damage to the magnetic flux gap portion of the head and head crashes can be significantly reduced. Since the magnetic flux gap is on the intersection line of the planes, the flying slider surface of the magnetic head, which is composed of multiple planes or curved surfaces, can be processed by simple WM polishing. is extremely easy.

Furthermore, the magnetic head having the flying slider surface of the present invention has the following characteristics:
It is easy to control the posture when landing on the magnetic recording medium, and since stress is not concentrated on the contact surface with the magnetic head, there is no damage to the magnetic recording medium or the magnetic head itself, making it highly reliable. High-density magnetic recording can be achieved with ease.

〔Example〕

An embodiment of the present invention will be described below in more detail based on the drawings. In addition, parts with the same reference numerals in FIG. 2 are the same parts or parts having the same function or performance.

(Embodiment 1) FIGS. 1(a), 1(b), and 1(c) are schematic diagrams showing the structure of a floating magnetic head which is an example of the present invention.

As shown in FIG. 1(a), the magnetic head 1 uses the dynamic pressure effect of the air flow in the X-axis direction parallel to the magnetic disk 8, which is a magnetic recording medium rotating at high speed in the direction of the arrow 9. It is floating in the Z-axis direction, which is the vertical direction of the disk 8.

Positioning within the xy plane parallel to the magnetic disk 8 is performed by a support spring and an arm portion (both not shown) of the magnetic head. The flying slider surface 2 of the magnetic head 1 is shown in FIG. 1(b) [viewed in the direction of arrow A in FIG. 1(a)] and FIG. 1(C) [viewed in the direction of arrow B in FIG. 1(a)]. This is achieved by two planes whose lines of intersection with the <+Zy plane are PiP, p, and p, as shown in the figure. In the case of this embodiment, the slider width W of the magnetic head 1 is 3.2 mm, a
The intersection angle θ of the two planes is 2h, /w=1.25 'rad
The flying slider surface 2 of the magnetic head 1 is formed by two planes that intersect with each other at =25.78 seconds, and the air inflow end 4 is formed in front of the flying slider surface 2. and 2 including point P2
A magnetic flux gap portion 3 of the magnetic head 1 is provided on the intersection line of the two flying slider surfaces 2. If the distance in the normal direction between the air outflow end 5 of the magnetic head 1 and the magnetic disk 8 is h, then the distance in the normal direction between the magnetic flux gap portion 3 and the magnetic disk 8 is Δh = (h − h,). . In the case of this embodiment, the distance h□ between the air inlet end 4 and the magnetic disk 8 is
is 0.8g, and the distance h between the air outlet end 5 and the magnetic disk 8 is
: o, 4I1m, distance in the normal direction between the air outflow end 5 and the tip of the magnetic flux gap portion 3 facing the magnetic disk 8. :
Since it is 0.27 an, it is possible to achieve the distance Δh=0.2 Iltm between the magnetic flux gap portion 3 and the magnetic disk 8.

(Example 2) In this example, as shown in FIGS. 2(a), (b), and (c), the magnetic flux gap portion 3 of the thin film type magnetic head 1
An example of a floating magnetic head of the present invention is shown in which a floating magnetic head is provided at the air outflow end 5 of the flying slider surface 2.

FIG. 2(a) is a perspective view showing the structure of the thin film type magnetic head 1, and FIG. 2(b) is the structure of the air outflow end 5 having the magnetic flux gap portion 3 in FIG. 2(a). FIG. 2(c) is a schematic diagram showing the floating state of the magnetic head shown in FIG. 2(a). ), the flying slider surface 2 has a cylindrical surface with a radius of curvature R, and the magnetic flux gap portion 3 is located at the top of the surface. The air inlet end 4 of the flying slider surface 2 is a single plane.

It intersects with the floating slider surface 2.

In this embodiment, the slider width is W, and the floating slider surface 2 is
When the radius of curvature of is R, and the distance in the vertical direction between the air outflow end 5 and the tip of the magnetic flux gap portion 3 facing the magnetic disk 8 is ho, the following relational expression holds true.

h, “-2R-hll+w”/4=0 where, w=3mm, R=5.625m, h,=
0.2-, and the distance h□ between the air inlet end 4 and the magnetic disk 8 is 0.8,1711. When the distance between the air outflow end 5 and the magnetic disk 8 is h = 0.4-, the distance between the magnetic flux gap portion 3 and the magnetic disk 8 is Δh = (h - h,) = 0,
You can get 2 prisoners. In the case of this embodiment, the flying slider surface 2 is one continuous cylindrical surface, but it is also possible to machine escape grooves for air flow or to make the cylindrical surface any curved surface. In either case.

The present invention is characterized in that the magnetic flux gap portion 3 is provided at the top of the curved surface, that is, at the position where the distance from the magnetic disk is the smallest when the magnetic head is flying.

(Example 3) The magnetic head (h
, =0.2am) and a conventional magnetic head in which the flying slider surface and the magnetic flux gap are in the same plane (h, =
o) on a magnetic disk with a diameter of 14 inches,
By varying the flying height of the magnetic head (spacing Δh (p)), which is the distance between the magnetic flux gap and the magnetic disk, the frequency at which the magnetic head contacts the magnetic disk (times/S) is
) was measured.

The results are shown in FIG. The above contact frequency measurement was performed by keeping the spacing Δh constant at a predetermined value, attaching a piezo element (shock detection sensor) for contact detection to the magnetic head, and seeking the magnetic head in the radial direction of the magnetic disk. The device was operated and the frequency with which the magnetic head contacted the magnetic disk was measured. As is clear from the figure,
When the spacing Δh=0.2-2, the magnetic head shown in Example 1 of the present invention has approximately 2.7 times/S.
The frequency of contact with the magnetic disk is extremely low, whereas in the case of a conventional magnetic head, the number of times of contact with the magnetic disk is about 27 times/s, which is about 10 times higher.2 The flying characteristics of the floating magnetic head of the present invention are even better. I understand that.

(Embodiment 4) Next, a hedra seek mechanism when the floating magnetic head shown in the above embodiments 1 and 2 is used in a magnetic disk device will be described.

Figure 4 shows Example 1 [Figure 1 (a), (b), (c)]
The magnetic head 1 shown in FIG. 1 is shown in a state where it is supported by a magnetic head support mechanism 15 and is grounded on a stopped magnetic disk 8.

Figure 5 shows Example 2 [Figure 2 (a), (b), (Q)]
The thin-film type magnetic head 1 shown in FIG. In both FIGS. 4 and 5, since the magnetic head 1 is given a predetermined amount of moment M by the support mechanism 15 in advance, it lands with one side of the flying slider surface 2 low and the other side high. ing. This prevents excessive contact stress from acting only on the magnetic flux gap portion 3 that protrudes in a narrow area. Also, Figure 6 (
As shown in a), the magnetic flux gap portion 3 is connected to the magnetic disk 8.
It is also possible to support the device in a non-contact manner.

As mentioned above, the moment M is constantly applied to the magnetic head 1 by the support mechanism 15.

When the magnetic disk 8 reaches a predetermined rotational speed, the state shown in FIG.
As shown in b), due to the difference in circumferential speed between the outer circumferential side and the inner circumferential side of the a-air disk 8, a buoyant force F0 on the outer circumferential side is applied to the magnetic head 1.
A buoyancy difference of F,>Fi occurs between the buoyancy force F on the inner peripheral side and the buoyancy force F, and the moment M caused by the support mechanism 15 is canceled out. As a result, as shown in FIG. 6(a), the distance Δh between the magnetic flux gap portion 3 and the magnetic disk 8 is stably maintained.

Note that in order to create a buoyancy difference such as Fo>Fi, it is necessary to
This is possible by performing aerodynamic design such as changing the width of the magnetic head 1, and it is also possible to arbitrarily control the attitude of the magnetic head 1 upon landing.2 By rolling in the X-axis direction upon landing, it is possible to It is also possible to remove dirt and sip while maintaining the symmetry of the shape.

As described in the above embodiments, in the floating magnetic head according to the present invention, only the magnetic flux gap portion can be brought close to the magnetic disk, which is a magnetic recording medium, and the distance between the flying slider surface and the magnetic disk can be made relatively large. As a result, the air layer passing through the slider flying surface becomes thicker, resulting in aerodynamically stable flying characteristics, resulting in a magnetic head with extremely low frequency of head crashes due to contact with the magnetic disk, making it highly reliable. This enables high-density magnetic recording with high performance. Furthermore, since the processing method is easy, highly reliable heads can be provided in large quantities at low cost.

〔Effect of the invention〕

As described above in detail, the floating magnetic head of the present invention maintains the flying slider surface as high as or higher than that of conventional magnetic heads.

Since the distance between the magnetic flux gap and the magnetic recording medium can be controlled to be extremely small, electromagnetic conversion characteristics are improved, a stable flying state is achieved, and head crash phenomena caused by contact with the magnetic recording medium can be significantly reduced. , it is possible to achieve highly reliable high-density magnetic recording. Furthermore, since the flying slider surface of the floating magnetic head of the present invention has a structure in which a magnetic flux gap portion is provided at the top portion formed by two or more plurality of plane portions or one or more curved surface portions, there is Contact stress is not concentrated in the magnetic flux gap portion, the posture when landing on the magnetic recording medium is extremely easy to control, manufacturing is simple, and a high-performance magnetic head can be obtained.

[Brief explanation of the drawing]

FIG. 1(a) is a schematic diagram showing the floating state of the magnetic head shown in Example 1 of the present invention, and FIG.
A view of the magnetic head in a) in the direction of arrow A. FIG. 1(Q) is a view of the magnetic head in FIG. 1(a) in the direction of arrow B;
FIG. 2(a) is a perspective view showing the structure of the magnetic head in Example 2, FIG. 2(b) is an enlarged view of the main part of the magnetic head in FIG. 2(a), and FIG. 2(c) is a perspective view showing the structure of the magnetic head in Example 2. Figure 2(a) is a schematic diagram showing the floating state of the magnetic head, and Figure 3 is a diagram showing the relationship between spacing and frequency of contact with the magnetic disk when using the magnetic head of Example 1 and the conventional type magnetic head. Graph showing. 4 is a schematic diagram showing the grounding state of the magnetic head shown in FIG. 1, FIG. 5 is a schematic diagram showing the grounding state of the magnetic head shown in FIG. 2, and FIG. 6(a) is a schematic diagram showing the grounding state of the magnetic head shown in FIG. FIG. 6(b) is an explanatory diagram showing the buoyancy difference caused by the difference in circumferential speed of the magnetic disk with respect to the magnetic head of FIG. 6(a), FIG. 7 is a perspective view showing an example of the structure of a conventional magnetic head, and FIG. 8(a) is a schematic diagram showing a floating state of the magnetic head shown in FIG. FIG. 8(b) is a view from arrow A of the magnetic head in FIG. 8(a),
FIG. 8(C) is a view of the magnetic head shown in FIG. 8(a) in the direction of arrow B. FIG. 1...Magnetic head 2...Flying slider surface 3
...Magnetic flux gap part 4...Air inflow end 5...
Air outflow end 6... Air inflow tapered part 8...
Magnetic disk 9...Rotation direction 10...Air flow 11...Slide rail 12...Magnetic core portion 13...Coil 14...Glass for magnetic flux gap 15...Support mechanism agent patent attorney Junnosuke Nakamura t2 diagram

Claims (1)

[Claims] 1. A magnetic flux gap section for performing magnetic recording and reproduction by electromagnetic conversion, and a floating slider surface on the side facing the magnetic recording medium that is made to float by airflow generated by the movement of the magnetic recording medium. In a floating magnetic head, the magnetic flux is centered around the magnetic flux gap provided on the floating slider surface.
Two or more plural flat parts or one or more curved parts so that a protrusion protruding toward the magnetic recording medium is formed in a substantially vertical plane including a center line extending in the flow direction of the air flow. The flying slider surface is configured by, and the magnetic flux gap portion is provided at a position where the distance between the protrusion of the flying slider surface and the magnetic recording medium is substantially minimum when the magnetic head is flying. floating magnetic head. 2. The main part of the flying slider surface is formed by two or more plane parts that intersect at a predetermined angle and form a mountain shape with respect to the magnetic recording medium side. Floating magnetic head. 3. The main part of the flying slider surface is formed by one or more cylindrical surface parts having a predetermined radius of curvature and forming an arc shape toward the magnetic recording medium side. floating magnetic head.