JPH01158607A - Magnetic head - Google Patents

Abstract

PURPOSE:To improve an electromagnetic characteristic and prolong a service life by providing an electromagnetic converting gap position in a specific position and holding the change of a spacing in an electromagnetic converting gap part small even when a form change occur around the gap. CONSTITUTION:A magnetic head is formed with nearly cylindrical read block 2 and write block 3. Electromagnetic gaps 4 and 5 having plural built-in thin film elements for electromagnetic converting in the central parts of the blocks 4 and 5. Plural grooves 8 are provided in parallel on both the sides of the gap 4 and in front of the gap 5. A magnetic tape runs through on the medium facing surface of the magnetic head 1 and the recording and the reproducing of data are executed. At this time, the gap part spacing increases and cylindrical part spacing decreases, therefore, when the electromagnetic converting gap position is made in the cylindrical spacing, the change of the electromagnetic converting gap part can be held small even when the form change occur around the gap and the electromagnetic characteristic and the service life can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic head for magnetic recording/reproduction using a flexible recording medium such as a magnetic tape, and particularly relates to a magnetic head for magnetic recording/reproducing using a flexible recording medium such as a magnetic tape, and particularly to a magnetic head for magnetic recording/reproducing using a flexible recording medium such as a magnetic tape. The present invention relates to a magnetic head suitable for keeping the value within a certain range regardless of changes over time.

[Conventional technology]

In a magnetic head that uses a flexible recording medium such as magnetic tape, in order to improve the electromagnetic properties and extend the life of the magnetic head, the air flow generated between the recording medium and the magnetic head is controlled and the electromagnetic conversion gap is It is necessary to maintain the gap between the magnetic head and the recording medium at a certain position, that is, the spacing, to a predetermined value or less, and to keep the spacing to a constant value regardless of the passage of time. Various inventions have been made and disclosed as techniques for this purpose. for example,
JP-A-58-199427 discloses a device that sprays pressurized fluid between the magnetic tape and the magnetic head by providing a groove in order to prevent the magnetic tape and the magnetic head from coming into close contact with each other when stopped and making it impossible to obtain an appropriate gap. This is attached to a magnetic head that has a magnetic head. Furthermore, Japanese Patent Application Laid-Open No. 60-103510 discloses that the magnetic head is configured such that the facing area of the magnetic head with respect to the flexible magnetic recording medium is smaller at both end portions than at the center portion in the width direction of the flexible magnetic recording medium. A technique is disclosed for forming contact surfaces and maintaining proper spacing. Furthermore, the technique disclosed in Japanese Patent Application Laid-Open No. 54-107314 provides a groove that completely surrounds the magnetic transduction gap on the floating surface of a flexible magnetic recording medium to obtain uniform spacing. It is something. Furthermore, in Japanese Patent Application Laid-Open No. 57-200930, a groove is provided in order to aerodynamically control the temperature of the floating air between the flexible recording medium and the magnetic head, and the groove is placed inward from the edge of the floating surface. A magnetic head is disclosed that is formed to have a smooth end.

[Problem that the invention seeks to solve]

As described above, as a means for regulating the spacing between the flexible recording medium and the outer periphery of the magnetic head, techniques have been proposed in which grooves of various shapes are provided on the outer periphery of the magnetic head. However, the conventionally proposed grooved magnetic heads have the following problems.

Figures 10(a) and (b) are from Japanese Patent Application Laid-Open No. 58-19942.
This figure shows the shape of the head of the magnetic head 1 disclosed in Publication No. 7.

The magnetic head 1 consists of a read block 2 for reproduction and a write block 3 for recording, each of which has a substantially cylindrical surface facing the magnetic tape, and an electromagnetic conversion gap 4.5 is formed in the center of each block. The electromagnetic conversion gap 4.5 forms a magnetic flux by a thin film element for electromagnetic conversion and corresponds to a track on the magnetic tape 6. Hereinafter, for convenience of explanation, the direction of the arrow 7 indicating the running direction of the magnetic tape 6 will be referred to as the rear, and the opposite direction will be referred to as the front. As shown in the figure, the lead block 2 includes
A plurality of grooves 8 are arranged in parallel at appropriate intervals on both sides of the electromagnetic conversion gap 40 (in a direction perpendicular to the arrow 7).

Furthermore, a groove 8 similar to that described above is also provided near the front edge of the outer periphery of the light block 3. This groove 8 is formed between the magnetic tape 6 and the magnetic head 1 when the magnetic tape 6 runs.
This is to control the amount of air flowing between the magnetic tape facing surface and to optimize the flying spacing of the magnetic tape 6 at the positions of the electromagnetic conversion gaps 4 and 5. As mentioned above, the write block 3 is provided with the groove 8 only on one side, but this is because the recording operation is performed only when the magnetic tape 6 runs in the direction of the arrow 7 (backward), and in the opposite direction (forward). ) This is because no recording operation is performed when the vehicle is running, so there is no need to optimize the spacing. Recording and reproduction are performed by engaging the magnetic tape 6 with the magnetic head 1 having the structure described above and running it in the direction of the arrow 7.

As mentioned above, the provision of 48 on the magnetic tape facing surfaces of the read block 2 and write block 3 controls the amount and flow of air caught between the magnetic tape 6 and the magnetic tape facing surface when the magnetic tape 6 runs. This is to narrow the above-mentioned spacing.

However, the edges of the grooves 8 on the surface facing the magnetic tape wear out over long periods of use, making it impossible to control the airflow, increasing the spacing, deteriorating the electromagnetic properties, and shortening the life of the magnetic head. The problem was that it was too short.

The present invention provides a magnetic head in which a plurality of grooves for controlling airflow are provided on the surface facing a recording medium, and the spacing can be maintained within a predetermined range even if the magnetic head wears out over time. The object of the present invention is to provide a magnetic head that maintains good electromagnetic characteristics and has a long life.

[Means for solving problems]

The magnetic head of the present invention is provided with a plurality of electromagnetic transducer gaps on the recording medium facing surface, and has a spacing between the flexible recording medium running along the recording medium facing surface and the recording medium facing surface. A plurality of grooves for adjustment are provided on the medium facing surface in parallel in the running direction of the medium, and is particularly characterized in that the grooves are provided in opposing positions between the respective electromagnetic conversion gap portions. .

[For production]

According to the present invention, since the grooves for spacing control are provided in opposing positions between the electromagnetic transducer gap parts, even if the magnetic head is worn out, the spacing can be kept narrow and the magnetic head can have a long life. It is possible to provide

Next, the principle of the present invention will be explained in comparison with the prior art.

FIG. 6(a) shows a part of the medium facing surface of the read block 2 of the magnetic head 1 described above, with arrows 9', 14
' indicates the air flow in the cylindrical portion and the groove 8 when the magnetic tape 6 runs. In the figure, symbol W indicates groove 8.
10 indicates the running direction of the magnetic tape 6. 6(b) is a side view of FIG. 7(a), and FIG. 6(e) is a line AA in FIG. 7(a) showing the state of air entrainment at the position of the groove 8. Cross-sectional view, FIG. 6 (dl is a cross-sectional view taken along the line B-B in FIG. 7(a) to show the state of air entrainment at the position of the cylindrical portion.

FIG. 6(a), (dl, the part where the magnetic tape 6 begins to face the medium facing surface of the magnetic head (part D in the figure)
Then, the distance between the magnetic tape 6 and the medium facing surface gradually decreases and becomes wedge-shaped. Therefore, as shown by the air flow 9, the air is strongly (involved), and as a result, a spacing he is formed in the electromagnetic conversion gap 4. On the other hand, as shown in FIGS. At part 8, the magnetic tape 6 and the medium facing surface begin to face each other (part 0 in the figure).
In this case, as shown by the air flow 14, there is little air entrainment, and the wedge-shaped effect described above is eliminated (as a result, a spacing hm smaller than the spacing he is formed at the position of the electromagnetic conversion gap 4.

In FIG. 7, the horizontal axis represents the groove width w (m+m) of the groove 8, and the vertical width represents the spacing he (μn+) of the cylindrical portion and the groove portion 8.
FIG. 2 is a diagram showing the spacing hm (μm) of FIG.

Note that this figure shows the pitch of the groove 8 being 0.63 mm, and the magnetic tape 6
tape speed 2m/s, tape tension 2.2N
, bending rigidity of magnetic tape E I =0.16N/mm2
These are the measurement results under the following conditions. In the figure, lines A and B indicated by white circles indicate the initial state when the medium facing surface (mainly the periphery of the groove 8) of the magnetic heald 1 does not rub, and lines C and D indicated by black circles indicate the progress of wear. Each state is shown below.

As shown by line A, the spacing he of the cylindrical portion decreases as the groove width W increases. On the other hand, as shown by line B, the spacing hm of the groove 8 gradually increases as the groove width W increases. Further, as the running time of the magnetic tape 6 progresses and the wear of the medium facing surface progresses due to changes over time, the spacing h as shown by line C.
e becomes smaller as a whole and slowly decreases as the groove width W increases. Moreover, as shown by the line, the spacing hm increases as a whole, and shows a gradual decrease with respect to the groove width W, which is almost the same as he in the line C.

In FIG. 8, the horizontal axis shows the tape running time t (hours) of the magnetic tape 6, and the vertical axis shows the spacings hm, he (μm).
The changes shown in FIG. 7 are displayed in relation to the tape running time t.

Here, the groove width W is larger than the groove width w2. As is clear from the figure, the spacing he exhibits a large value in the initial state, but rapidly decreases as time passes, and then settles to a substantially constant value. On the other hand, the spacing h11 is smaller than the spacing he in the initial state, but increases rapidly over time and continues to increase thereafter.

This tendency remains the same even when the groove width W changes (indicated by solid line W and dotted line Wg).

FIGS. 9(a) to 9(C) are diagrams for explaining that the value of the spacing her bl in the initial state has the relationship as described above (he>hm).

The edge portions 11 on both sides of the groove tip 129 at the periphery of the groove 8 are each square in the initial state. Therefore, only a small portion of the air flow 9 flows into the groove 8 as indicated by the arrow 9'. Therefore, as shown in the spacing distribution 13 in the width direction of the magnetic tape 6 in FIG. 9(C), low spacing hm and higher spacing he are alternately formed, resulting in a wave-shaped spacing distribution. . On the other hand, Fig. 9 (
d) to FIG. 9(g) show the state when the medium facing surface is worn to some extent. Not only the edge portion 11 is sagging, but also the groove tip 12 is sagging with a dimension δ.

Therefore, due to the droop of the edge portion, a large amount of air flows into the groove 8 from the air flow 9 in the cylindrical portion, as shown by the arrow 9'. At the same time, the wedge effect increases due to the droop of the groove tip 12, and an air flow as shown by the arrow 14' is generated in the groove 8. Therefore, as shown in FIG. 9 (phantom), the spacing he of the cylindrical portion becomes smaller, the spacing h+a of the groove 8 becomes larger, and the spacing distribution 13 becomes a waveform distribution with an opposite phase to that of FIG. 9(a). Become.

As is clear from the above description, the groove spacing hlII increases and the cylindrical spacing he decreases as the tape running time progresses. This tendency remains the same even if the groove width W changes.

The upper limit of the spacing is determined by the recording and reproducing system such as the circuit of the device that attaches the magnetic head, so if the electromagnetic conversion gap is located in a portion corresponding to the groove spacing hm, the life of the head will be short; In addition, it can be seen that the life is extremely long when the cylindrical portion is located at a portion corresponding to the spacing he. Therefore, if the magnetic head is configured such that the electromagnetic conversion gap position is opposed to the cylindrical part spacing he, its life will be very long.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1(a) and 1(b), the magnetic head 1 is composed of a substantially cylindrical read block 2 and a write block 3.
An electromagnetic transducer gap 4.5 containing a plurality of electromagnetic transducer thin film elements 7 (shown in FIG. 1(b)) is formed in the center of the transducer. A magnetic tape 6 runs on the medium facing surface of the magnetic head 1, and records and reproduces data. magnetic tape 6
A groove 8 of an appropriate width is provided near the edge of both sides of the magnetic transducer gap 4 of the read block 2 that engages, and a groove 8 is also provided on the front side of the magnetic transducer gap 5 of the write block 3. ing.

A plurality of grooves 8 are arranged in parallel at appropriate intervals in a direction perpendicular to the running direction of the magnetic tape 6. Note that the groove 8 is deep near the edges and becomes shallower as it approaches the electromagnetic conversion gaps 4 and 5.
It is formed from an inclined surface that eventually coincides with the surface. In addition, as shown in Figure 1 (bl), the electromagnetic conversion gap 4 (5
The magnetic flux is formed by an electromagnetic conversion gear part 4a, which is a unit of (the same applies to), and a thin film element 7 for electromagnetic conversion, and tracks are formed on the recording medium corresponding to the electromagnetic conversion gap part 4a.

The magnetic helad 1 as described above is manufactured by a known technique.

That is, a plurality of electromagnetic conversion elements are formed on a substrate of N, Z, Puerite, etc. using normal thin film formation technology,
An element block is cut and processed, and a block for forming an electromagnetic conversion gap 4 (5) is adhered thereto. Thereafter, the medium facing surface (the outer peripheral surface of the magnetic head 1) is ground and lapped to give it a cylindrical shape. At this time, as shown in FIG. 1 fb), the medium facing surface is finished so as to have an appropriate cassocket size gd by controlling the amount of machining. Next, grooves 8 having the shape described above are bored on the medium facing surface.

Next, the positional relationship between the groove 8 and the electromagnetic conversion gear part 4a will be explained.

As shown in FIG. 1(b), the electromagnetic conversion gap portion 4a is a part of the thin film element 7, and as shown in FIG. 2, electromagnetic conversion gear portions 4a having a wide width are arranged at a pitch P. A groove 8 having a width W is formed on an extension line of the central position of the adjacent electromagnetic conversion gap portions 4a.

Now, assuming that the grooves 8 are arranged at pitch P, all the grooves 8 are arranged to face each other between the electromagnetic conversion gear parts 4a, and are placed on the extension line in the tape running direction of the central position between the electromagnetic conversion gear parts 4a. It will come. From the opposite perspective, all the electromagnetic transducer gap parts 4a are arranged at positions facing the cylindrical part of the magnetic head.

FIG. 3 shows changes in the spacing above the electromagnetic conversion gear part 4a of the magnetic head 1 in the embodiments shown in FIGS. 1+a), (b) and FIG.

In this example, the width dimension L of the electromagnetic conversion gap portion 4a is 0.4.
/nun, pitch P of electromagnetic conversion gap portion 4a = 0,
63 mm, and the groove width w of groove 8 is 0.25 mm. In FIG. 3, the horizontal axis represents the running time t(
hr), and the vertical axis indicates spacing h (μm).

Since the spacing on the electromagnetic conversion gear part 4a has a distribution, the spacing on each electromagnetic conversion gear part 4a is integrated over the entire gear width, and this is divided by the width of the electromagnetic conversion gap part 4a. Figure 3 is displayed with an average spacing h. In this case, the spacing h is as shown in equation 11.

hmIoLh dL/L -・-・---
−−−−−−−−−−−−(1) As mentioned above, if the spacing of the cylindrical portion is he and the spacing of the groove 8 is hm, the spacing h is approximately calculated by the formulas (2) and (3). It will be like this.

(1) When the groove 8 is on the extension line of the center position between the electromagnetic conversion gear parts 4a (in the case of this embodiment) h = (he(
P-w)+11m (L, -(P-w)) /L・--
---1...-1-------(2) (2) When the groove 8 is on the extended line of the center of the electromagnetic conversion gap portion 4a (in the case of the prior art) h = (hm-w+he( L-w)) /L ---
--(3) In FIG. 3, the line E shows the spacing h in the case of the above equation (2), and the dotted line F shows the spacing h in the case of the above equation (3). That is, in the latter case, the spacing h increases as the running time t of the magnetic tape 6 increases, whereas in the former case, which corresponds to this embodiment, after a certain running time, the spacing h increases. A constant value. From this, in the case of this embodiment in which the groove 8 is arranged at the center between the electromagnetic conversion gear parts 48, the spacing h is constant, and it is possible to obtain a magnetic head 1 with a long life and without deterioration of electromagnetic characteristics. can.

FIG. 4 shows another embodiment of the invention.

This embodiment is a case where the width dimension of the electromagnetic conversion gap portion 4a is made smaller than that of the previous embodiment.

In this case, the groove 8 is not placed on the extension line of the center position between the electromagnetic conversion gear parts 4a, but on the extension line of the center position between one pair of electromagnetic conversion gap parts 4a and the adjacent pair of electromagnetic conversion gap parts 4a. The structure is such that a groove 8 is provided in the groove. Even in the case of this embodiment, the electromagnetic conversion gear part 4
The spacing h above a is kept approximately constant, and the same effect as in the previous embodiment can be achieved. FIG. 5 shows yet another embodiment. In the case of FIG. 4, as described above, the width dimension of the electromagnetic conversion gap portions 4a is made small (and the electromagnetic conversion gap portions 4a are arranged at equal intervals), but in this embodiment, a pair of electromagnetic conversion gap portions 4a are arranged at equal intervals. Conversion gap section 4b
, 4c are arranged at regular intervals, and adjacent electromagnetic conversion gap parts 4b and 4c arranged in the same manner are arranged at equal intervals different from the above-mentioned intervals. In this case as well, the electromagnetic conversion gap 4
By providing the groove 8 on the extension line of the central position between the combinations b and 4c, the same effect as in the previous embodiment can be achieved.

Furthermore, in this embodiment, the groove width w, the track width,
) It is possible to set various rack pinches P, etc., and to make the relationship between the groove and the track so that the spacing of the electromagnetic conversion gap part of the thin film element for electromagnetic conversion approaches the spacing he in the cylindrical part. Those that do are included in the present invention. Further, the present invention can be applied to both read blocks and write blocks, and can also be applied to other than thin film magnetic heads.

〔Effect of the invention〕

According to the present invention, even if wear occurs on the medium facing surface of the magnetic head and changes in shape occur around the groove, changes in spacing in the electromagnetic transducer gap can be kept small, resulting in the effect of improving electromagnetic characteristics and lifespan. It can be raised.

[Brief explanation of the drawing]

FIG. 1(a) is a perspective view showing an embodiment of the present invention, FIG. 1(b) is a perspective sectional view showing the relationship between tracks and grooves of the thin film element of the embodiment, and FIG. 2 is a perspective view showing an embodiment of the present invention. A top view for explaining the relative position between the electromagnetic conversion gap portion and the groove in one embodiment, FIG. 3 is a diagram showing the relationship between the average spacing h and the magnetic tape running time, and FIGS. 4 and 5 6(a) is a plan view showing the relationship between the electromagnetic conversion gap portion and the groove in another embodiment of the present invention; FIG. 6(a) is a plan view showing the role of the groove provided in the magnetic head; FIG. ) is ■- in Figure 6 fa)
■ Cross-sectional view, Figure 6 (C) is an enlarged cross-sectional view taken along the line A-A of Figure 6 (a), Figure 6 (dl is an enlarged cross-sectional view taken along the line B-B, Figure 7 is the conventional magnetic waiting time t) Diagram showing the relationship between
Figures 9(d) to 9(fc) are explanatory diagrams showing the air flow and spacing distribution in the tape width direction in the initial state of a conventional magnetic head, and Figures 9(d) to 9(gl are diagrams showing the distribution of air flow and spacing in the tape width direction in the initial state of a conventional magnetic head. 10(a) is a plan view showing the main structure of a conventional magnetic head, and FIG. 10(b) is a diagram showing the distribution of air flow and spacing.
It is a sectional view taken along the l line. 1...Magnetic head, 2...Read block, 3...
・Light block, 4, 5...Magnetic conversion gap, 4
a. 4b, 4c... Electromagnetic conversion gap part (1 unit), 6.
... Magnetic tape, 7... Thin film element for electromagnetic conversion, 8.
... Groove, 9.11... Edge portion, 12... Groove tip, 13... Spacing distribution in the width direction of the magnetic tape. Agent Patent Attorney Tadashi Akimoto (Fig. 1 + 6) Fig. 1 (b) 3: Light film O. riff 6: IILR tape 4.5; Denkushi 6, Knob 7: Zero film element Fig. 2 Fig. 3 4: Electric equipment cheap knob 7: Thin 1 odor element 462 tm
,・Puko 1 photo ezo i nonobu*shi a:>*Figure 4
Figure 5 4: e 2 p [return to] Noah 4a, 4b, 4c: electric a * exchange ya"t7' sound p8:
A Fig. 6 (a) Fig. 6 (C) Fig. 6 (CI) 4: Electrical l conversion frame/Nof 0 8: Feces Fig. 7 Fig. 8 Chi 2° Ashitake Ginkan t (hr) No. Fig. 9 (CI+ Fig. 9 (1)) Fig. 9 (C) 9.97% included sacrificial claw 12:★Pre-baked part Fig. 9 (d)
Fig. 9 (e) Fig. 9 (1) Fig. 9 (g) 4: Denmaku [Katagitonopu] 10:7 value 51 ka material h4
To 13: Tape 1 (1 to own tape 31
) 8: * 11: Pickled vegetables,
shi"ki15 14,14':"Tamiji\ri trap 9.9
': Air 1 good IIL 12: Mu tip Iku Figure 10 (a
) Figure 10(b)

Claims (1)

[Claims] 1. Spacing between a flexible recording medium that has a plurality of electromagnetic transducer gap portions on the recording medium facing surface and runs along the recording medium facing surface and the recording medium facing surface. A magnetic head having a plurality of grooves arranged in parallel in the running direction of the medium on the medium facing surface for adjusting the magnetic head, characterized in that the grooves are arranged to face each other between the respective electromagnetic conversion gap parts. magnetic head. 2. The magnetic head according to claim 1, wherein the groove is provided in such a manner that an end of the groove in the width direction faces an end of the electromagnetic conversion gap. 3. The magnetic head according to claim 1, wherein a plurality of said grooves are provided in parallel in opposing positions between respective electromagnetic conversion gap portions. 4. Claims characterized in that an end in the width direction of the groove located at at least one end of the plurality of grooves provided in parallel faces an end of the electromagnetic conversion gap portion. The magnetic head according to item 3. 5. The magnetic head according to claim 1, 2, or 3, wherein the plurality of grooves are provided in front and behind the plurality of electromagnetic conversion gap portions, respectively, in front of and behind the recording medium. 6. The magnetic head according to claim 3, wherein the plurality of grooves are provided in front and rear of the plurality of electromagnetic conversion gap portions in the recording medium running direction, respectively.