JPS62149013A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To attain miniaturization of a magnetic disc recording/reproducing device and to reduce the cost by decreasing sequentially the gap of an inner circumferential track side element more than the outer circumferential track side element in a multi-track thin film magnetic head. CONSTITUTION:As to the gap (d) of an element E, the head is shaped by the machining such as lapping so as to obtain the relation of d1>d2...>dn-1>dn. The electromagnetic conversion efficiency of the inner circumferential track is improved in comparison with the outer circumferential track by the shaping, the signal output decrease by the medium sliding linear speed is compensated, resulting that it is possible to obtain a signal whose characteristic is uniform from the outer circumference to the inner circumference. Further, the quantity of wear due to disk slide is larger for the element of the element toward the outer circumference because of the difference in the sliding speed and since the gap of the element larger toward the outer circumference, resulting that the service life of each element is made uniform. Thus, the miniaturization of the head is attained and the cost is reduced in this way.

Description

[Detailed description of the invention] (The following is a blank space) 3. Detailed description of the invention [Field of industrial application] The undeveloped IJj relates to a thin film magnetic head, and more specifically, it is used in a magnetic disk recording and reproducing device. This invention relates to a multi-track type thin 11!2 magnetic helad having a large number of electromagnetic transducers.

[Prior art] Thin-film magnetic heads manufactured by the thin +12 deposition method or photolithography technology, which is similar to the manufacturing process of la conductor ICs, can be modified to minute shapes, making it possible to improve signal conversion. The =j-method of magnetic circuits and electric circuits for this purpose can be made small, and therefore, it is easy to integrate a large number of electromagnetic transducers f into multi-tracks.

In fact, digital audio tape (abbreviated as DAT) converts audio signals into digital signals and performs magnetic recording (if raw).
), it is expected that a multi-track fD film head will be put to practical use in which 20 or more electromagnetic transducers f- are integrated at a pitch of 80 pm.

In this conventional example, magnetic tape is used as the recording medium, and all of the elements integrated in the magnetic head are in contact with the tape at the same time.
Also, as a matter of course, it slides at the same speed across all trunks to convert and transmit signals. For this reason, it is not necessary that the electromagnetic conversion characteristics of the plurality of elements integrated in the housing and the mechanical characteristics of the wear shade be uniform.

On the other hand, it is also conceivable to apply the multi-track head to a device that uses a magnetic disk as a recording medium. In particular, a multi-track head can be used relatively easily in the case of a flexible disk or a magnetic sheet that does not require a mechanism for floating the head. These devices include floppy disk drives for computers and electronic still cameras that are expected to be put into practical use in recent years.

Among these, the use of a multi-track head is advantageous for electronic still cameras, which are required to be smaller and lower in cost than other devices.

In other words, a precise head feeding mechanism with a track pitch of 101) 7 layers requires a high degree of I' and viscosity, which not only causes high costs but also has a limit to its miniaturization. A multi-track head using a thin single block and a photolithography process has the advantage that the cost increase due to multi-tracking is small, the size of the head itself is small, and a head feeding mechanism is not required.

Although the use of thin film multi-track heads is expected for disk-shaped media as described above, there are the following problems.

Since the rotational speed of the disk is constant, the linear velocity differs between the inner and outer circumferences. For example, in the case of a video floppy, the innermost circumference is 5.65 disks/sec, and the outermost circumference is 7.54 disks/sec. In the case of an inductive magnetic head, the voltage generated by Ilf is proportional to the relative speed between the medium and the head.

Even if the characteristics of the element on the inner circumferential side and the element f on the outer circumferential side are constant,
This will cause a difference in the ILF raw characteristics. Furthermore, in terms of mechanical properties, due to the difference in sliding speed between the head and the medium,
Since the head wears at different rates and "unilateral burrs" occur between the inner track and the outer track, there are problems such as a decrease in output voltage and a shortened head life due to an increase in the distance between the head and the medium.

[Problems to be Solved by the Invention] An object of the present invention is to solve the above-mentioned technical problems, and to provide a magnetic disk recording/reproducing device in which electromagnetic conversion characteristics are uniform between the inner track and the outer track, and the medium runs more smoothly. The object of the present invention is to provide a thin film multi-track head with a long service life.

[F stage for solving the problem] In order to achieve the above object, in the thin film magnetic head of the present invention, in a multi-track thin film magnetic head in which a large number of electromagnetic transducers are integrated, the outer track side The element is characterized in that the gap depth of the element on the inner track side is sequentially smaller than that of the element.

[Function] With this configuration of the present invention, (1) the signal characteristics generated by +IT become uniform over all tracks, making signal processing easier; (2) the lifetime of each track element f becomes uniform; as a result, This has the effect of extending the life of the head, making it possible to reduce the size and cost of magnetic disk recording and reproducing devices.

[Example] The present invention will now be described with reference to the drawings.

FIG. 2 is a partially cutaway view for explaining a configuration in which a multi-track thin film head is used in a magnetic disk recording/reproducing apparatus, where ▪ is a multi-track thin film head and 2 is a magnetic disk. The disk 2 is provided with n recording tracks as indicated by Trl...Trn in the figure. On the other hand, Herad 1 has n electromagnetic transducers f(
(indicated by E 1 , E2-En + , and En in the figure).

In the figure, the head protection plate is omitted to make it easier to see the electromagnetic transducer element f, and the head support mechanism or disk holding pad cap is omitted for convenience.

FIG. 1 is an enlarged perspective view of an embodiment of the thin film magnetic head of the present invention. 3 is M. -20 ferrite or N1-Z,
Ferai)? With a magnetic substrate, n from E1 to E0 is placed on this hill.
The trunk element f is formed by a dollar film deposition technique or a photolithography technique, and these elements are integrated.

In the figure, elements from the third element to the (n-2)th element are omitted. 4
1 is the Dobe magnetic core composed of a metal magnetic thin film, 4+ is a conductive wire that winds the core, and 1 is the conductor between the magnetic substrate 3 and the conductor 5 that inputs and outputs the air signal, and the conductor 5 and the upper magnetic core 4. An insulating film is formed between them. 6 is a magnetic gap for generating and supplementing a magnetic field.

In the figure, the protective plate attached to the edge of the element and the insulating film forming the element are omitted. The boundary line between the stepped portion where the upper core 4 crosses the conductive wire 5 and the portion forming the magnetic gap 6 is indicated by 7. The distance from this boundary line 7 to the sliding surface of the disk is called the gap depth.The gap depth of the element El is 6
1. Let the gap depth of element fE2 be d2. Here, M child E n
−+ dnl, element E; Here, dn represents the gap depth.

In conventional multi-track heads, this gap depth is constant in order to make the electromagnetic conversion characteristics of the element uniform, that is,
d+=d2=-=dnt=d. According to the present invention, as shown in FIG. 2, d 1 >
d2 >>> dn l :) The head is shaped by lapping or other mechanical oil so that It is possible to compensate for the low signal output due to a decrease in sliding linear velocity, and as a result, to obtain a signal with uniform characteristics from the outer circumference to the inner circumference.Furthermore, wear due to disk sliding is reduced by sliding. Due to the difference in dynamic speed, the elements on the outer circumferential side are larger, but according to the present invention, the gap depth is larger on the outer circumferential side, so it is possible to make the life of each element uniform as a result. becomes.

In the above embodiments, a magnetic substrate was used as the substrate, but a non-magnetic substrate such as a ceramic substrate may be used, and an f-section core such as a gold kI5 magnetic thin film may be formed on the hill by a thin film forming technique.
In Figure 2, an example is shown in which the conductor has one turn, but the number of turns and structure of the coil, the shape of the upper core, etc.
It does not specify the scope of J.

Further, in the previous explanation, an example was shown in which the gap depth was changed by machining, but an element may be formed by arranging a pattern of six elements f so that the gap depths differ by f.

[Effects of Lyj from C] As explained above, by configuring the gap depth of the elements on the inner track to be sequentially smaller than the elements on the outer track, (1) the characteristics of the reproduced signal are spread over all the tracks; It becomes uniform and signal processing becomes easy.

(2) The lifespan of each track element becomes uniform, and as a result, the lifespan of the head is extended.

This brings about the effect of reducing the size and cost of the magnetic disk recording/reproducing device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an embodiment of a multi-track thin film head of the present invention, and FIG. 2 is a block diagram of a magnetic disk using a multi-track head. l...Multi-track lIl! 2 heads 1.2...
・Magnetic disk. 3...Magnetic substrate. 4... Upper magnetic core, 5... Conductor. 6...Magnetic gap, 7...Gap depth boundary line. dηgi★tour 5゛￥sa

Claims (1)

[Claims] 1. A multi-track thin film magnetic head in which a large number of electromagnetic transducers are integrally constructed, wherein the gap depth of the elements on the inner track side is sequentially smaller than that of the elements on the outer track side.