JPS58200418A - Magnetic head - Google Patents

Abstract

PURPOSE:To eliminate the head gap loss and to reproduce the ultra-high density recording with high quality, by shifting the magnetic pole parts of a ring head so that they are not opposite to each other, and forming the magnetic pole end faces opposite to a magnetic recording medium at the same level. CONSTITUTION:The counter faces of magnetic pole parts 12 and 13 of a ring head 13 are shifted so that they are not opposite to each other on a plane X-Z and that both counter faces are on the plane X-Z. In other words, the gap length of a conventional head is set at O. Furthermore the parts 12 and 13 opposite to the face of a magnetic recording medium are set on the same plane X-Y. This enables the reproduction with no gap loss and without setting the head width W (in the track direction) of the magnetic pole larger than the conventional ring head width. Thus the reproduction is made possible at a minute recording wavelength (<=0.3-0.2mu) smaller than the detecting limit of a conventional head.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a magnetic head that is capable of reproducing minute recorded bits in reproducing information in magnetic recording.

[Technical background of the invention and its problems]

Magnetic recording is currently widely used in various fields as a means of storing audio, images, and digital information for computers.

Magnetic recording device is day! Alternatively, it consists of a disk-shaped recording medium and a magnetic head for recording and reproducing information on the medium. Figures 1(a) and 1(b) show the principle of a conventionally used magnetic head.
Fig. 1(b) is a front view, and Fig. 1(b) is a side view of Fi, where 1 is the head core, JVi coil, and 3 is the head! , 4 is the magnetic flux, 5 is the recording medium, 6 is the recording magnetization in the medium, and λ is the recording wavelength. Head 1. It is called a ring head because of its shape. In FIG. 1(&)(b), the reproduction method is as follows. Leakage magnetic flux 4 leaked out of the medium from the medium magnetization 6
is spread by the herad core 1, and the change in magnetic flux that intersects with the coil 2 causes an electromagnetic induction force to be generated in the coil 2. In the case of a magnetic head, when the gap length 9 of the head becomes an integral multiple of the recording wavelength λ, the magnetic flux does not pass through the herad core and closes within the head gear lug, so the output becomes zero. This is called headgear lag gain/loss, and cannot be avoided with conventional structures, which is the ratio of the gap length to the recording wavelength! Figure 2 shows what happened. It can be seen that when 9/λ is an integer, the output becomes zero. Although it is currently possible to avoid this point of zero output in terms of the current method, if high recording quality is required, the output part #i where g/λ is 1 or more is not used, as Hiro said in recent years due to the increase in information density. As technology improves, the recording wavelength A decreases, and it has become possible to record at λ]0.3 to 0.2 μm.

Therefore, Head Zeya! It has become necessary to reduce the long I value to below the recording wavelength. However, if the head gap length I is made smaller, a problem arises in that the reproduction efficiency decreases. FIG. 3 shows this in principle. @3
In the figure, 1 is the magnetic flux passing through the core, and the magnetic flux passing through the MFi ~ gap, and the efficiency is the total magnetic flux (7
+8) to the magnetic flux 7 passing through the head core 1. However, it is assumed that there is no other leakage magnetic flux.

and ζroga ~ Rad gap length 9': The smaller the value, the smaller the magnetic resistance of the magnetic path passing through the ear lug (the magnetic permeability of the head core and the head lug varies depending on the signal frequency, but it is 200 to 100,000). Efficiency will become smaller due to 1000 times more spatula and fl Sakae 7.To put it in an extreme, if it becomes zero, the efficiency will also become zero and no reproduction output will be obtained.

[Purpose of the invention]

In order to solve the above problems, the present invention is designed to shift the magnetic pole parts of the ring head so that they do not face each other, and the corresponding surfaces are on one surface. do.

[Embodiments of the invention]

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

Fig. 4 is a perspective view of an embodiment of the Honsha's head, showing the two magnetic poles 11° and 12 of the conventional ring head. The shape is shifted in the direction of the house.

13 is a head core. FIG. 5 is a diagram showing the $4 diagram in the X-Y plane, where W is the width of the head. FIG. 6 is a diagram showing FIG. 4 in the x-2 plane. Also, Fig. 7 shows Fig. 4 as Z-Y.
This figure shows a magnetic flux source as a recording medium 14 below the head.

The two magnetic poles 11.1n are connected at one end and form a ring shape when viewed from the ZYfiili. The overall shape is one ring with a portion cut out and twisted. In the continuous magnetic poles 11.1211C, the surfaces facing each other are Y=0. There are 12 planes on the same plane, and they are offset from each other by a distance of W/2. Moreover, ge
In the plane of =Q, both magnetic pole end faces are on the same plane, and the recording medium 14 is placed below this. 115Fi magnetic flux, 1i
Indicates Fi magnetization.

The qualitative principle of this head is as follows.

In FIG. 7, the magnetic flux 11Fi entering from the magnetic pole 11 of one head core is very close to the magnetic flux 11Fi as in the conventional head shown in FIG.
Since the magnetic pole of the other rad core with high magnetic permeability is dangerous, there is no magnetic flux leaking through it, so if there is no other leakage magnetic flux, 100% will pass through the rad core to the other magnetic pole 1.
2, it will flow to the medium again. However, as shown in Figure 5, the width W of the head is the overall width, but the width into which the magnetic flux enters is W/2. Although the efficiency is obviously improved, if we compare the width of the conventional head as W, we will show the 0th order which requires a more detailed case classification.

FIG. 8 is a schematic diagram of a conventional head, in which b#i recording medium 5
and the distance between the head, Is, and Is-Im are the arm length meters (indicating the flat magnetic path length of the herad core), and 1. By the way, from the edge of the magnetic pole of core 1! The length to the point where it splits into five directions and one direction, 1m, is from the splitting point to the end face of the head ear lug, from the flat length of the herad core! If we apply Ampere's circulation theorem to the model in Figure 8, which shows the length after subtracting , then the part that passes through the head core will have a head gap! The one passing through is . However, μ and voice are both radcore.

Magnetic permeability of air (head gap also has the same magnetic permeability as air) "m -"a -B b -BittSotLSotL.

1m, ts part, between the medium and the spatula P, shows the cross-sectional area of the magnetic flux density bslFi head pole end face 9, vs, 12 shows the magnetomotive force from the medium, and from the conditions of the magnetic circuit, Bs 8. ”Bm 8s +Bt stB b =
B*, B y = B.

81.8□8. Fi, that's it! ,,l*-1m-1m
is the cross-sectional area of the head of the part. The magnetic flux density B1 of the 71st part is calculated from the equation of Limp. Similar calculations are performed using the model shown in Figure 117.

If the noodles of each part are the same as the #'iSS diagram, but the cross-sectional area of the head magnetic pole tip is 8*/', then (nFi positive number) the model in the s8 diagram will work! This is because the magnetic flux that passes through disappears. (If B in equation (4) becomes larger than B1 in the three-part system, it is equivalent to the efficiency of this head becoming greater than that of the conventional one.Moreover, if this head is used,
In principle, the loss of W4 becomes zero, making it possible to reproduce up to an infinitely small pit size.

B of the conventional head is changed to B l:l and B of the present head.

If ni:l is M, -8, then the argument <2.69
...... ()) If the width of the magnetic pole of the conventional head is W, then the width of one magnetic pole of this head is W.
7 m, and the width of the two magnetic wires is 2 W/n. mm"
When using 169, the overall width of this head is 0.74W.If the width is made under the above conditions, the width of the conventional head is 74W.
It is possible to manufacture a head having a width of 100 mm and no Gats f loss. Furthermore, +31, +4) From the formula, B,)B
By adding the condition j''l, each head/parameter can be determined, but by the way, by setting the condition of equation (6) and 1 = 2, find the relationship between the head length y and the head-medium distance. Figure 9 shows s j'
l>n! Relationship between b and l to obtain m'fI:
In the case of klJchib -0,2μ, which indicates that the area shown with diagonal lines satisfies this condition, the current head's length is higher than that of the conventional head with a length of JF -0,27μ and F. In this case, the magnetic flux circulating around the head core is larger (rh=2), so the overall spatula V width is the same as the conventional one.

Another embodiment of this head V is shown in Figure (a) (-).

21 is a magnetic pole, an xzFi head core, and a zsFi coil. Figure 1 θ (a) (This is a thin film head made of thin film such as dust, soft ferrite, etc.), and the magnetic pole 11 of the ring head is similar to that shown in Figure 4. are shifted from each other, and the corresponding directions are the same - but E.

In the figure, the surface in contact with the rolling medium is thickened to prevent some wear and tear.
Although the thin film coil 23 is wound as a turn, the number of turns may be increased or decreased.Also, it is possible to use a detection method other than the type in which magnetic flux changes in the head core 22 are detected using a coil, such as the one shown in FIG. To K (31 is a wire through which current flows, iFi current), make the rad core 12 part with a magnetoresistive element and connect current terminals to any two points of the two magnetic poles. Alternatively, as shown in Figure 1112, (41 is a polarized light source, 42 is an analyzer, and 43# is a photodetector) A Radcore 44O body is made of magneto-optical material, a part of the tli is irradiated with t-light, and the transmitted light from the magnetic pole of the polarized light is (or reflected light) may be received by a photodetector through an analyzer and detected as a change in magnetoresistance, Faraday, or Kerr effect, respectively.The present invention relates to the shape of a herad core and defines a detection method. It's not something you do.

Father Hetsu? The material is commonly used soft ferrite, Sendust! - In addition to Malloy, any material with high magnetic permeability may be used. The present invention does not specify the head material. Also, Figures 4 and 10 are early examples and are compatible with the idea of the present invention. Not all head configurations are within the scope of the present invention.

〔Effect of the invention〕

As described above, by using the magnetic head according to the present invention, the head width (width in the track direction) of the conventional ring head can be increased. Therefore, the current recording wavelength of 0.3 is considered to be the detection limit for ~rad.
Reproduction is also possible at even smaller wavelengths of up to 0.2 μm or F.

Therefore, in fields where magnetic recording is used in audio, image, computer digital recording, etc., the head of the present invention can be used to achieve ultra-high density reproduction, resulting in improved quality and lower cost of magnetic recording.

It is believed that this technology can make a significant contribution to improving reliability.

[Brief explanation of the drawing]

Figure 1141 (&) (b) is a diagram of the principle of a conventional head, (a) is a front view, (b) is a side view thereof, and Figure 2 is the output versus the ratio of gap length and recording wave force in the conventional head. Figure 3 is a diagram showing the characteristics, Figure 3 is a diagram for explaining the gear horn loss of the conventional head, Figure 4 is a perspective view of the head of the present invention,
Figures 1 to 7 show heads of the present invention t-ttL, tLX-Y.
fii, the diagram shown in the X-Z plane, the Y-2 plane, the SS diagram is a diagram showing a model for calculating the magnetic flux density in a conventional head,
Fig. 9 is a diagram showing the region where the amount of magnetic flux passing through the head core, which is a measure of output, is mostly (( a) (b) Fi A plan view and a side view showing another embodiment of the present invention; FIG. 11 is a diagram showing another embodiment of reading out a reproduced signal using the spatula y of the present invention; FIG. 12 is a diagram showing another embodiment of the present invention. This is another embodiment in which a reproduced signal is read using a head. 11.12...Magnetic pole, 11...Head core, 14.
... Recording medium, 15... Magnetic flux, 16... Magnetization. Applicant's agent Patent attorney Takehiko Suzue Figure 1 (a) (b) Figure 2 Figure 8 Figure 9 bψm) Figure 10 Figure 11 Figure 31 9° Month □ (° + r゛ day) Director of the Japan Patent Office 11 Kazuo Sugi 1, Case Indication Special - No. 1983-83850 2 Q Ming's Name Magnetic Head: (, Among those who make a wl correction (4) Relationship with Patent Applicant (422) ) Nippon Kame Shinden Ayu Public Corporation 1, Agent 5 Date of amendment order August 31, 1980 b χ′T diagram of amendment Plane 7, Contents of amendment

Claims (1)

[Claims] Magnetic poles made of two opposing magnetic materials are connected at one end, and at the other end, the mutually facing surfaces are on the same plane, and spatially the two magnetic pole surfaces are shifted to the point where they are not in the same place. A magnetic head further comprising a rad core having a shape in which one of each of the magnetic pole end faces intersecting with the shifted surface is in the same plane.