JPH06131647A - Floating type magnetic head - Google Patents

Abstract

PURPOSE:To solve a problem that a signal in an adjacent track is detected by a trailing edge with a contagion effect, and the signal is superposed on the correct signal as a noise, in a floating type magnetic head in a magnetic disk device. CONSTITUTION:A groove 14 is provided on the base of the magnetic gap forming part 13 of the trailing adge 12a side of the rail 11a of the floating type magnetic head. Thus, the correct signal is detected and accurate positioning is executed since the sensitivity detecting the signal in the adjacent track becomes low and the detection is impossible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating magnetic head for a magnetic disk device used for recording / reproducing data in a computer or the like.

[0002]

2. Description of the Related Art In recent years, there have been floating type magnetic heads in which a slider is provided with two levitation rails and a magnetic gap is formed outside one of the rails.

A conventional floating magnetic head will be described below. FIG. 12 is a perspective view of a conventional floating magnetic head. In FIG. 12, reference numeral 1 is a slider made of a magnetic material such as ferrite, 2a and 2b are parallel flying rails provided on the slider 1, and 3a and 3b are trailing edges of the rails 2a and 2b, respectively. Reference numeral 4 denotes a magnetic gap forming portion provided along an outer portion of the rail 2a on the trailing edge 3a side. The width of the magnetic gap forming portion 4 is narrower than the width of the rail 2a, and the magnetic gap forming portion 4 has the rail 2a. The trailing edge 3a is protruded by a predetermined length in the longitudinal direction. Reference numeral 5 is a C-shaped core made of a magnetic material such as ferrite. The C-shaped core 5 is abutted against the magnetic gap forming portion 4 via the non-magnetic film 6 serving as a magnetic gap, and is joined with the fused glass 7.
The magnetic gap facing surface of the magnetic gap forming portion 4 is formed parallel to the trailing edge 3a. Reference numeral 8 is a magnetic gap portion composed of the magnetic gap forming portion 4, the C-type core 5 and the non-magnetic film 6, 9 is a winding wound around the C-type core 5, and the winding 9 is used for recording and reproduction.

The operation of the floating magnetic head having the above structure will be described below. First, by holding the magnetic gap portion 8 at a predetermined track position where a signal of a magnetic recording medium (not shown) should be detected, the magnetic gap portion 8 detects the signal and a magnetic flux corresponding to the signal is generated by the magnetic gap forming portion. 4 and the C-shaped core 5 and a corresponding current flows through the winding 9. The current flowing in the winding wire 9 is transmitted to an electric circuit section (not shown) by a lead wire of the winding wire 9. Winding 9
The information of the current flowing through is reproduced by the function of the electric circuit section and detected as a signal.

[0005]

However, in the above-mentioned conventional structure, when the magnetic gap portion 8 is held at a predetermined track position, the trailing edge 3a of the rail 2a is positioned on the adjacent track. Become. At this time, the wavelength of the signal is, for example, 50 to 50 such as a servo signal.
If it is about 600 μm, the trailing edge 3a detects the signal of the adjacent track due to the contour effect, so that the signal of the adjacent track appears as noise in the original signal, which causes a problem that the original signal cannot be detected correctly. Was there.

The present invention solves the above-mentioned conventional problems, and a floating type which can detect a correct signal without detecting a signal of an adjacent track detected by a trailing edge when a magnetic gap detects a signal. An object is to provide a magnetic head.

[0007]

To achieve this object, the floating magnetic head of the present invention has a groove formed along the longitudinal direction of the rail at the root of the joint of the C-shaped core of the flying rail. Have a configuration.

[0008]

With this structure, the magnetic path of the magnetic circuit constituted by the trailing edge for detecting the signal of the C-shaped core including the winding and the adjacent track becomes longer by the amount of bypassing the groove, resulting in noise. The detection sensitivity of the signal of the adjacent track becomes low, the signal of the adjacent track cannot be detected,
The original signal can be detected correctly.

[0009]

【Example】

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

FIG. 1 is a perspective view of a floating magnetic head according to a first embodiment of the present invention. In FIG. 1, 10 is a slider made of a magnetic material such as ferrite, and 11a, 1a.
1b is a rail for flying provided parallel to each other on both ends of the slider 10, and 12a and 12b are rails 11 respectively.
It is the trailing edge of a and 11b. Reference numeral 13 denotes a magnetic gap forming portion provided integrally with the slider 10 along the outermost portion of the rail 11a on the trailing edge 12a side. The magnetic gap forming portion 13 is narrower than the width of the rail 11a and has a predetermined length. It projects from the trailing edge 12a along the longitudinal direction of 11a, and the magnetic gap facing surface is parallel to the trailing edge 12a. 14
Is a groove provided along the longitudinal direction of the rail 11a at the root of the magnetic gap forming portion 13 on the rail 11a surface side.
The outer width of the trailing edge 12a side end of the rail 11a divided by 4 is equal to the width of the magnetic gap facing surface of the gap forming portion 13 on the rail 11a surface side. 1
Reference numeral 5 denotes a C-shaped core made of a magnetic material such as ferrite. The C-shaped core 15 is butted against the magnetic gap forming portion 13 via a non-magnetic film 16 which serves as a magnetic gap.
Are joined together. 18 is a magnetic gap forming portion 13 and C
It is a magnetic gap portion composed of the mold core 15 and the non-magnetic film 16.

2 to 9 are process diagrams showing a method of manufacturing a floating magnetic head according to the first embodiment of the present invention. As shown in FIG. 2, 1 mm × 2 mm × 30 mm made of a magnetic material such as manganese (Mn) -zinc (Zn) ferrite
A core block 19a serving as a C-shaped core of about 4 mm ×
Core block 1 that becomes a slider of about 2 mm x 30 mm
Prepare 9b. Next, as shown in FIG. 3, winding grooves 20 and 21 each having a predetermined shape are formed in the core blocks 19a and 19b on the longitudinal side surfaces of the core blocks 19a and 19b, which face the magnetic gaps, by grinding or the like, and The magnetic gap facing surfaces 22 and 23 are mirror-finished by a lapping method. Next, as shown in FIG. 4, the core block 19a
Of the iron (Fe) -aluminum (A
l) -A metal magnetic film 24 of silicon (Si) or the like is formed by sputtering or the like. In the first embodiment of the present invention, the metal magnetic film 24 is formed in order to improve the magnetic characteristics, but the metal magnetic film 24 may not be formed. Also, core block 1
Silicon dioxide (Si
A nonmagnetic film 25 such as O ₂ ) is formed by sputtering or the like so as to have a predetermined thickness. Next, the magnetic gap facing surfaces 22 and 23 of the core block 19a and the core block 19b are butted against each other via the metal magnetic film 24 and the non-magnetic film 25 and bonded with a fused glass to manufacture the magnetic core block 26 shown in FIG. To do. Next, as shown in FIG. 6, the magnetic core block 26 is slightly larger than the width of the floating magnetic head of the final finished product 7 to 7
A single magnetic core 27 is produced by cutting into about 10 pieces.
Next, as shown in FIG. 7, a ski groove 28 having a predetermined size is formed on the magnetic gap forming surface side of the magnetic core 27 by processing such as grinding. Next, as shown in FIG. 8, the end of the magnetic core 27 on the joint side is processed by grinding or the like to form a core 29 that becomes a winding part.
Are formed on the magnetic core 27, and the magnetic core 27 is ground and chamfered to form the levitation rails 11a and 11b having a predetermined dimension on the magnetic gap forming surface side of the magnetic core 27. Next, as shown in FIG. 9, grinding is performed from the inner end surface of the core 29 to the depth A of the winding window so that the track portion 30 has a predetermined width on the magnetic gap forming surface side of the core 29. The groove 14 is formed at the same time when the track portion 30 is formed. The floating magnetic head of the first embodiment of the present invention is completed by the manufacturing method described above.

The operation of the floating magnetic head having the above structure will be described with reference to FIG. First, by holding the magnetic gap portion 18 at a predetermined track position where the signal of the magnetic recording medium should be detected, the magnetic gap portion 18 detects the signal. At that time, since the trailing edges 12a of the rails 11a are located on the plurality of adjacent tracks, the signals of the plurality of adjacent tracks are detected by the contour effect of the trailing edges 12a. Since the magnetic path of the magnetic circuit composed of the die core 15 and the trailing edge 12a has the groove 14, the groove 1
Since it becomes longer by detouring 4, the detection sensitivity of the signals of a plurality of adjacent tracks which become noise is lowered and cannot be detected, so that the original signal can be correctly detected.

The characteristics of the floating magnetic head according to the first embodiment of the present invention and the characteristics of the conventional floating magnetic head are shown in FIG.
It is shown in comparison with (a) and (b). Figure 10 (a)
Is a reproduced waveform of a solitary wave by the floating magnetic head according to the first embodiment of the present invention, and FIG. 10B shows a reproduced waveform of a solitary wave by the conventional floating magnetic head. FIG. 10 (a),
The recording pattern of the solitary wave in (b) has a wavelength of 500 μm.
m, the recording width is 300 μm, the recording pattern has a magnetic gap width of 10 μm, and a flying rail width of 300 μm.
The data is reproduced by the floating magnetic head according to the present embodiment and the conventional floating magnetic head. In FIG. 10B, a pseudo peak is detected before the main peak. The distance from the main peak to the pseudo peak corresponds to the distance L from the magnetic gap to the trailing edge 3a in FIG. In the case of the first embodiment of the present invention shown in FIG. 10 (a), no pseudo peak is observed.

As is apparent from FIGS. 10 (a) and 10 (b), the floating magnetic head according to the first embodiment of the present invention detects the signal of the adjacent track at the trailing edge and detects it as a pseudo peak. And an excellent effect is obtained in that the recorded pattern is reproduced faithfully.

As described above, according to the first embodiment of the present invention, the rail 1 is provided at the root of the junction of the C-shaped core 15 of the trailing edge 12a of the rail 11a of the floating magnetic head.
By providing a groove 14 along the longitudinal direction of 1a and joining the C-shaped core 15 to the magnetic gap forming portion 13 via the non-magnetic film 16, the C-shaped core 15 including the winding 9 and the adjacent track can be formed. Since the magnetic path of the magnetic circuit composed of the trailing edge 12a for detecting a signal becomes longer by bypassing the groove 14, the detection sensitivity of the signal of the adjacent track which becomes noise becomes low and cannot be detected. Can be correctly detected.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings. FIG. 11 is a perspective view of a floating magnetic head showing a second embodiment of the present invention. In FIG. 11, 31 is a slider made of a magnetic material such as ferrite, 32a and 32b are levitation rails provided at both ends of the slider 31 in parallel with each other, and 33a and 33b.
Are trailing edges of the rails 32a and 32b, respectively. 34 is the trailing edge 33 of the rail 32a
The magnetic gap forming portion is provided integrally with the slider 31 at the outermost portion on the a side.
It is narrower than the width of 2a and protrudes from the trailing edge 33b along the longitudinal direction of the rail 32a by a predetermined length. Reference numeral 35 is a rail 32a of the magnetic gap forming portion 34.
A groove having a triangular shape on the surface of the rail 32a provided at the root of the surface side is cut along the longitudinal direction of the rail 32a, and one end of the groove 35 forms a magnetic gap. It is in contact with the base of the portion 34. The inclination angles θ1 and θ2 of the apex of the triangle, which is the shape of the groove 35 on the surface of the rail 32a, with respect to the trailing edge 33b are inclined 5 degrees or more with respect to the trailing edge 33b.
36 is a C-shaped core made of a magnetic material such as ferrite.
The mold core 36 is butted against the magnetic gap forming portion 35 via the non-magnetic film 37 serving as a magnetic gap, and the fused glass 3
It is joined at 8. Reference numeral 39 denotes a magnetic gap portion including the magnetic gap forming portion 35, the C-shaped core 36, and the nonmagnetic film 37. The magnetic gap facing surface of the magnetic gap portion 39 is parallel to the trailing edge 33b. The windings are omitted and not shown.

The operation of the floating magnetic head having the above structure will be described below with reference to FIG.
First, the magnetic gap portion 39 is held at a predetermined track position where the signal of the magnetic recording medium is to be detected, so that the magnetic gap portion 39 detects the signal. At that time, the rail 32a
Since the trailing edges 33a of the trailing edges 33a are located on the plurality of adjacent tracks, the signals of the plurality of adjacent tracks are detected by the contour effect of the trailing edges 33a. Since the portion has the groove 35, the magnetic path of the magnetic circuit formed by the C-shaped core 36 and the trailing edge 33a is the groove 35.
Since it becomes longer by the amount detouring around, the detection sensitivity of the signal of the adjacent track which becomes noise becomes low and detection becomes impossible.
Further, since the portion of the trailing edge 33a that is inclined by the angle θ with respect to the gap facing surface is inclined by the angle θ with respect to the signal recording pattern, an azimuth loss represented by (Equation 1) occurs, and noise of an adjacent track becomes noise. Since the signal detection sensitivity is lowered and the groove 35 is further cut into the rail 32a, the magnetic path of the magnetic circuit is lengthened.
Since the signal detection sensitivity of the adjacent track which becomes noise becomes low and cannot be detected, the original signal can be correctly detected.

[0018]

[Equation 1]

La is azimuth loss, W is noise detection width,
λ is a recording wavelength, and θ is an azimuth angle.

As described above, by making the groove 35 triangular, the trailing edge is inclined with respect to the recording pattern of the signal, so that an azimuth loss occurs, and the detection sensitivity of the signal of the adjacent track which becomes noise is increased. Since it becomes too low to be detected, the original signal can be detected correctly.

In the first embodiment of the present invention, the end face of the groove 14 in the longitudinal direction of the rail 11a in the longitudinal direction is in the same position as the end face of the winding window, and the groove 14 in the thickness direction of the slider 10 is in the same position. The depth is formed from the surface of the rail 11a to the winding window. The length of the groove 14 in the longitudinal direction of the rail 11a is 0.5 mm or more, and the depth of the groove 14 in the thickness direction of the slider 10 is: If it is 0.3 mm or more, the effect does not change. Also,
Even if a non-magnetic material such as glass is buried in the groove 14 of the floating magnetic head, the effect does not change. Further, the magnetic gap forming portion 13 is provided integrally with the rail 11a so as to project from the trailing edge 12a. However, since the problem of fringing is eliminated by providing the groove 14, the magnetic gap forming portion 13 is not necessarily provided from the trailing edge 12a. It may not be projected.

Although the number of the grooves 35 is one in the second embodiment of the present invention, it may be two or more. Needless to say, the shape of the groove 35 may be an arc shape as long as it is not parallel to the magnetic gap on the surface of the levitation rail.

[0023]

As described above, according to the present invention, by providing a groove along the longitudinal direction of the rail at the root of the joint portion of the C-shaped core of the rail forming the magnetic gap of the floating magnetic head, the C-shaped groove is formed. Since the magnetic circuit of the magnetic circuit including the trailing edge of the levitation rail that detects the signal of the track adjacent to the core becomes longer as it bypasses the groove, the detection sensitivity of the signal of the adjacent track that becomes noise decreases Since it becomes impossible, it is possible to realize an excellent floating magnetic head that can correctly detect the original signal.

[Brief description of drawings]

FIG. 1 is a perspective view of a floating magnetic head according to a first embodiment of the invention.

FIG. 2 is a process diagram showing a method of manufacturing a floating magnetic head according to a first embodiment of the invention.

FIG. 3 is a process chart showing the method of manufacturing the floating magnetic head according to the first embodiment of the invention.

FIG. 4 is a process chart showing the method of manufacturing the floating magnetic head according to the first embodiment of the invention.

FIG. 5 is a process chart showing the method of manufacturing the floating magnetic head in the first embodiment of the invention.

FIG. 6 is a process drawing showing the method of manufacturing the floating magnetic head in the first embodiment of the invention.

FIG. 7 is a process chart showing the method of manufacturing the floating magnetic head according to the first embodiment of the invention.

FIG. 8 is a process chart showing the method of manufacturing the floating magnetic head according to the first embodiment of the invention.

FIG. 9 is a process chart showing the method of manufacturing the floating magnetic head according to the first embodiment of the invention.

10A is a reproduction waveform of a solitary wave by the floating magnetic head according to the first embodiment of the present invention, and FIG. 10B is a reproduction waveform of a solitary wave by a conventional floating magnetic head.

FIG. 11 is a perspective view of a floating magnetic head showing a second embodiment of the present invention.

FIG. 12 is a perspective view of a conventional floating magnetic head.

[Explanation of symbols]

 9 Winding 10 Slider 11a Rail 11b Rail 12a Trailing edge 12b Trailing edge 13 Magnetic gap forming part 14 Groove 15 C type core 16 Nonmagnetic film 17 Fused glass 18 Magnetic gap part 31 Slider 32a Rail 32b Rail 33a Trailing edge 33b Trailing edge 34 Magnetic gap forming part 35 Groove 36 C type core 37 Non-magnetic film 38 Fused glass 39 Magnetic gap part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshinobu Homoto 1006 Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. A floating type in which a slider is provided with a plurality of levitation rails, and a core is joined to an outer portion of an end surface of the slider perpendicular to the longitudinal direction of the rail via a nonmagnetic material serving as a magnetic gap. A magnetic head, wherein a groove is provided along the longitudinal direction of the rail at the base of the joint portion of the core. 2. A floating magnetic head according to claim 1, wherein a non-magnetic material is embedded in the groove. 3. The length of the groove rail in the longitudinal direction is 0.5 mm.
2. The floating magnetic head according to claim 1, wherein the length of the groove in the thickness direction of the slider is 0.3 mm or more.