JPH03201235A - Magnetic head - Google Patents

Abstract

PURPOSE:To prevent generation of crosstalk without incorporating an independent C-electrode by using a metal magnetic material having large saturation magnetic flux density as the magnetic material and drawing the top end of a magnetic pole. CONSTITUTION:A conducting magnetic member 3 having a lead wire 2 is inserted between a pair of nonmagnetic insulating substrates 1 and a magnetic gap 5 is formed on the medium-sliding part 4 of these conducting magnetic member and the substrates. The length of the conducting magnetic member 3 in the sliding part 4 which formed the magnetic gap 5 is made about <=20 mum by covering with a nonmagnetic insulating material 6. The conducting magnetic member 3 is used both for a magnetic pole and an electrode, consisting of such a metal magnetic material having large saturation magnetic flux density and the top end of which is drawn. Thereby, generation of crosstalk can be prevented without incorporating an independent C-electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a magnetic head incorporated in a magnetic disk device for recording and reproducing a recording medium having capacitive tracking bits.

(Prior Art) Generally, the highest track density in a magnetic disk device is approximately 1700 TPI (track pitch 1
5 μm), and this value is approximately
CD) and grooveless capacitive recording systems (VHD)
(registered trademark)) etc., it is only about 1710. The reason for this is due to the difference in tracking servo methods.

In order to solve this problem, a system has been proposed in which a tracking signal track consisting of a grooveless capacitive bit string is provided separately from the information signal recording/reproducing track.

A magnetic head (vertical head type) incorporated in this type of magnetic disk device that has already been proposed is configured as shown in FIG.
issue).

That is, in FIG. 8, a pair of canute levers b are provided horizontally on the stylus actuator a.
A perpendicular magnetic head A is attached to the tips of both cantilevers b. This magnetic head A is a so-called main pole excitation type head, and includes a magnetic yoke C made of a ferrite material or the like and formed in a substantially U-shape that opens downward and is attached to the tip of a cantilever b, and this magnetic yoke. A thin magnetic film d made of so-called permalloy (F e-N e alloy) is attached to the front end surface of the yoke C, and the magnetic film d is attached to the front surface of the yoke C so as to sandwich the magnetic film d in a sandwich-like manner. The slider 5 is made of a non-magnetic material and slides along the track surface of the disk B attached to the lower open end of the magnetic yoke C.

At the front end of the magnetic yoke 31, a winding (coil) g is wound around the bonded portion of the yoke C, the magnetic film d, and the hard plate material e. The coil g is connected to an information signal recording circuit (not shown) and a reproduction circuit (not shown).

A main magnetic pole is formed by the magnetic material Jlid.

This main magnetic pole film d also serves as a pickup electrode for capacitance detection using the pit row of the tracking signal track and h, and is connected to a capacitance change detection circuit (not shown) via a fly lead i.

On the other hand, a ring-shaped magnetic head to which a C electrode is added has already been proposed, as shown in FIG.

That is, in FIG. 9, a magnetic material q is interposed between a pair of non-magnetic substrates ○ and p, and a pair of non-magnetic substrates ○ and p with a winding window rl are interposed between the three non-magnetic substrates ○ and p. non-magnetic substrate r, s
A magnetic body t interposed between the two is provided facing each other. Further, a C electrode U and a low melting point glass V are interposed between the non-magnetic substrates o, p, magnetic material q and each non-magnetic substrate rSs, magnetic material t, and this magnetic head has a ring. It makes up the head type.

(Problem to be Solved by the Invention) However, although the above-mentioned former magnetic head (vertical head type) is theoretically effective, in practice it has poor recording and reproducing efficiency, and in practice it is difficult to obtain a reproducing output. is not enough.

On the other hand, the latter magnetic head (ring head type) described above requires a ctIi pole to be added in addition to the magnetic pole, which makes the configuration complicated and the assembly and adjustment troublesome, making it difficult to provide at a low price. Have difficulty.

The present invention was made in view of the above-mentioned circumstances, and by using a metal magnetic material with a high saturation magnetic flux density as the magnetic material and narrowing down the tip of the magnetic pole, crosstalk can be avoided without incorporating an independent C electrode. An object of the present invention is to provide a magnetic head that does not generate.

[Structure of the invention]

(Means for Solving the Problems and Their Effects) The present invention provides a bulk ring-type magnetic head in which a conductive magnetic member having a lead wire is interposed between a pair of non-magnetic insulating substrates,
A magnetic gap is formed in the medium sliding contact area between the two, and the electrode length of the conductive magnetic member in the medium sliding contact area where the magnetic gap is located is coated with a non-magnetic insulator to a length of about 20 μm or less, and the magnetic pole By using metal magnetic material with high saturation magnetic flux density and narrowing the magnetic pole tip, crosstalk is generated without incorporating an independent C electrode. I tried not to do that.

(Example) Hereinafter, the present invention will be described with reference to an illustrated embodiment.

1 to 3, reference numeral 1 denotes a pair of wear-resistant non-magnetic insulating substrates each having a winding window 1a in a bulk ring-type magnetic head; A conductive magnetic member 3 made of permalloy, Sendust, etc., having a lead wire 2 is interposed between the two valves, and the medium sliding contact portion of both the valve magnetic insulating substrate 1 and the conductive magnetic member 3 is interposed therebetween. 4, a magnetic gap 5 is formed. The electrode length of the conductive magnetic member 3 of the medium sliding contact portion 4 where the magnetic gap 5 is located is approximately 20 μm or less, and is coated with wear-resistant non-magnetic insulators 6.

In particular, the reason why the electrode length of the conductive magnetic member 3 according to the present invention is limited to about 20 μm or less is because detection sensitivity decreases when the electrode length becomes 172 mm or more compared to the wavelength of the signal to be detected. This electrode length is set to be 1/2 or less of the wavelength.

That is, the system example according to the present invention is more constrained by the frequency of the address signal than the tracking signal.

In other words, the frequency of the tracking signal is 200 to 3
On the other hand, in order to make the pit length as short as possible, the frequency of the address signal is selected around IMHz so as not to be an integral multiple of the frequency of the tracking signal. For example, if the diameter of the magnetic disk is 120 mm% and the rotation speed is 360 Orpm, then λ/22-1 at IMHz.
1p, but the frequency of the address signal is 500 KH
Assuming that approximately z is selected, the above magnetic pole length is 20 μm.
It becomes below.

Note that in terms of the magnetic recording/reproducing performance and manufacturing of the magnetic head, it is desirable that the magnetic pole length be long.

Therefore, the bulk ring-type magnetic head according to the present invention is
Since the conductive magnetic member 3 is formed in a ring shape, by connecting the lead wire 2 to a part of the conductive magnetic member 3, this can be connected to the magnetic pole of the medium sliding surface that acts as an electrode. Electrical continuity is obtained.

That is, the conductive magnetic member 3 according to the present invention serves as both a magnetic pole and an electrode, and by using a metal magnetic material with a high saturation magnetic flux density and narrowing the magnetic pole tip, crosstalk can be eliminated without incorporating a C electrode. We are trying to prevent this from occurring.

Next, in another embodiment of the present invention shown in FIGS. 4 to 6, a lead wire is connected to the junction of a pair of insulating magnetic materials 7 made of, for example, Ni-Zn ferrite, forming a window 7a. 8
A conductive magnetic member 9 is attached. The thickness of the conductive magnetic member 9 determines the electrode length, so the thickness of the conductive magnetic member 9 is
It should be less than μm. A gap material is formed on the abutting surfaces to form a magnetic gap 5, and a non-magnetic insulator 6 is embedded in a groove for regulating the track width of the medium sliding contact portion 4 where the magnetic gap 5 is located. It is.

On the other hand, in another embodiment of the present invention shown in FIG. The medium sliding contact portion 4 is formed with a slight taper.

〔Effect of the invention〕

As described above, according to the present invention, in a bulk ring-type magnetic head, a conductive magnetic member having a lead wire is interposed between a pair of non-magnetic insulating substrates, and a magnetic material is attached to the medium sliding contact area between the two. A gap is formed, and the electrode length of the conductive magnetic member of the medium sliding contact portion where the magnetic gap is located is approximately 20 mm.
The magnetic pole is coated with a non-magnetic insulator to serve as both the magnetic pole and the C electrode, which not only improves recording and reproducing efficiency, but also allows the magnetic pole itself to function as the C electrode. Therefore, when the C electrode is provided separately, the tracking signal does not jump from the sitting magnetic pole to the C electrode, and moreover, it is possible to use a metal magnetic material with a high saturation magnetic flux density as the magnetic pole. It has excellent effects such as being able to be incorporated as a high-performance magnetic head equipped with C electrodes into a magnetic disk device configured with a magnetic recording medium having a capacitive tracking bit string.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the main parts of the magnetic head of the present invention, FIG. 2 is an enlarged plan view of the same, FIG. 3 is a sectional view of the same, and FIG.
7 to 7 show other embodiments of the present invention, and FIG.
9 and 9 are perspective views of conventional magnetic heads. 1... Non-magnetic insulating substrate, 2... Lead wire, 3...
Conductive magnetic member, 4... Medium sliding contact portion, 5... Magnetic gap, 6... Nonmagnetic insulator.

Claims (1)

[Claims] In a bulk ring-type magnetic head, a conductive magnetic member having a lead wire is interposed between a pair of non-magnetic insulating substrates, a magnetic gap is formed at the area where the medium slides between the two, and the position of this magnetic gap is A magnetic head characterized in that the conductive magnetic member of the medium sliding contact portion is coated with a non-magnetic insulator to have an electrode length of about 20 μm or less, so as to serve both as a magnetic pole and an electrode.