JPS6174102A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain high density recording by specifying a coercive force of a magnetic recording medium, a residual magnetic flux density, a surface coarseness and a saturated magnetic flux density near the magnetic gap of a magnetic head and its gap length respectively to a specific range. CONSTITUTION:The coercive force of a magnetic layer 22 is specified to 1,200-2,000 oersted, the residual magnetic density is to >=1,200 gauss and the surface coarseness is to <=0.03mum respectively and the part near the magnetic gap 5 of the magnetic head is constituted with a magnetic substance having a high saturated magnetic flux density of >=7,000 gauss and the length of the magnetic gap is specified in the range of 0.15-0.4mum. Thus, high density recording is attained, a high output is obtained and high reliability is kept.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic recording medium such as a disk or a tape, and a recording or reproducing device that performs No. 3 recording or reproduction without contacting the magnetic layer with rP4. The present invention relates to a magnetic recording/reproducing device equipped with a magnetic head, and particularly to a magnetic recording/reproducing device that is capable of high-density recording, provides high output, and is highly reliable.

(Prior Art) Conventionally, magnetic disk recording and reproducing devices that are said to be capable of high-density recording use high-retention materials as magnetic materials for magnetic recording media.
C6-containing r Fe with a force of 600 to 800 oersteds
A ferrite head with a gap length of 1 to 2 μm was used as an fft head. However, with this recording/reproducing device, D5. (Note that the output is 50% of the long wavelength recording/reproduction output!1 density is expressed as . This is a guideline for the maximum recording density that can be achieved as a recording/reproduction device), but the recording/reproduction is at most about 20 KBPI wide. Can not.

In order to significantly increase the recording capacity of magnetic recording media such as magnetic disks, D. High-density recording of 40KBP1 or more is required.

[Problem to be solved]

The purpose of the present invention is to eliminate such drawbacks of the prior art,
It is an object of the present invention to provide a magnetic recording and reproducing device that is capable of high-density recording, provides high output, and is highly reliable.

[Means for solving problems]

In order to achieve the above-mentioned objective, the present inventors conducted various researches and found that the coercive force, residual magnetic flux density, and surface roughness of the magnetic layer in a magnetic recording medium, as well as the magnetic material near the magnetic gap in a magnetic head, have been investigated. Saturation magnetic flux density and gap length (
It has been found that there is an extremely important correlation between the characteristics (the length of the magnetic recording medium running direction) and that it is necessary to specify these factors.

That is, in addition to regulating the coercive force of the magnetic layer in the FFI magnetic recording medium to 1,200 to 2,000 Oe, the density of the magnetic layer to 1,200 Gauss or more, and the surface roughness to 0.037+m or less, The above objective was achieved by making the vicinity of the magnetic gap constituted of a magnetic material having a high saturation magnetic flux density of 7000 Gauss or more, and by regulating the magnetic gap length in the range of 0.15 to 0.4 μm. It is something.

〔Example〕

FIG. 1 is a longitudinal sectional view of a magnetic head according to the present invention.

The magnetic head includes a first core half 1, a second core half 2,
It mainly consists of an excitation coil 3 wound around one half of the core.

The first core half 1 is composed of a first core base body 4 and a first laminated magnetic film B6 attached to the magnetic gear 5 side thereof, and the first laminated magnetic film 6 is in the middle. The first non-magnetic thin film 7 and 15 [! It consists of a first fff-sensitive thin film 8 placed thereon. Similarly, the second core half 2 also has a second core base body and a second) fail-resistance rIIA1 attached to the magnetic gap 5 side thereof.
The second laminated transparent film 10 consists of a second non-magnetic vagina 11 placed in the middle and second magnetic thin films 12 placed on both sides of the second non-magnetic vagina 11.

The material of the core base 4.9 is, for example, manganese.
A magnetic material having high magnetic permeability such as zinc ferrite or Nichel-zinc ferrite, or a non-magnetic material such as ceramic or zinc ferrite is used.

As the material of the non-magnetic element 11, a non-fn material such as silicon dioxide or glass may be used.

As the material for the magnetic thin films 8 and 12, an amorphous alloy having a high saturation r flux density and a high 131-ft ratio is used. This amorphous alloy consists of elements of lf1 or higher from the ashes of the iron, nickel, and cobalt groups, and elements selected from the phosphorus, carbon, boron, and silicon groups.
An alloy consisting of 1'1 or more elements, or aluminum containing these as the main component.

Germanium, beryllium, tin, molybdenum 1 indium, tungsten, titanium, manganese.

There are alloys to which elements such as chromium, zirconium, hafnium, and niobium are added, and alloys containing cobalt and zirconium as main components and the above-mentioned additional elements.

FIG. 2 is an enlarged longitudinal cross-sectional view of the magnetic recording medium according to the present invention.

The magnetic recording medium is composed of a non-magnetic support 21 and a magnetic FFI 22 coated on one or both sides thereof.

The non-magnetic support 21 may be made of polyester, polyimide, aluminum, etc. The monolithic waste 22 may be made of, for example, gold 17! ferromagnetic metal powders such as iron-nickel alloy powders and iron-nickel alloy powders, and vinyl chloride-vinyl acetate-vinyl alcohol! 1 polymer.

A paint containing a binder such as polyurethane and, for example, ketone 1° toluene or alcohol is applied to the non-magnetic 1'1\1v.
It is formed by applying <2 cloth on the body 2I and calendering each time.

When the magnetic recording medium according to the present invention is used as a magnetic disk, the (ft11) grains need to be oriented irregularly in the plane or along the circumferential direction of the disk.

Using magnetic paint with a redistributive composition? The magnetic layer was coated on both sides of a polyester base film having a thickness of 5 prn, and then calendered to form a magnetic layer, which was then punched out into a circle of 51 mm to form a 1 yen disk.

(Composition of stone mineral material) Ferromagnetic metal iron powder 450 heavy weight vinyl chloride-vinyl acetate-vinyl alcohol co-combination
50-layer sliding part (Niriurethane resin
30 parts by weight, 20 parts by weight of trifunctional i1X low molecular weight isocyanate compound, 36 parts by weight of carbon black, Al
TOS powder 27 parts by weight・α-Fe 0. In a magnetic recording medium containing 18 parts by weight of powder, 14 parts of 2-ethylhexyl oleate (fatty acid ester), 650,311 parts of synchrohexanone, and 650 parts of toluene, the above-mentioned ferromagnetic metallic iron powder has a coercive force of 1.
100-17500. , saturation magnetization amount is 100-300
The surface roughness was changed by changing the surface treatment conditions of the magnetic layer (temperature and pressure of the calender roll in the calendering processing device) and used as magnetic disk samples. .

On the other hand, the magnetic head has the structure shown in FIG. ! R
A magnetic head with a single layer of iron-aluminum-silicon alloy (Sendust) is used instead of the 2N magnetic film 10,
Magnetic head samples were prepared by varying the gap length and the saturation magnetic flux density of a magnetic material with high saturation magnetic flux density placed near the magnetic head.

The coercive force () (c), residual magnetic flux density (Br), and surface roughness (Ra) of these magnetic disk samples were varied, and the gap length (gl) and saturation of the magnetic material near the magnetic gap of the magnetic head sample. The head output of a representative one is a combination of various magnetic flux rotations (Bs).

The S/N, Ds*, and peak shift are shown in Tables 1 and 2 below. Among the characteristics, if Dsa is 5QKBPI or more, it is evaluated as high-density recording. In addition, it is preferable that the head output is 0.3 mV or more in relation to amplifier noise, S/N is 65 dB, and peak shift is 15 dB.
Each is preferably ns or less.

The surface roughness Ra in the table was measured using a tactile surface roughness meter under the conditions of a stylus diameter of 2 μm, a tactile load of 25 mg, a force of 7 to 0.08 +uw, and a scanning speed of 0.03 w++/sec. In addition, Examples 1 to 3 and Comparative Examples 1 to 2
has the same structure as shown in FIG.
1. A magnetic head in which No. 12 was made of a cobalt-zirconium dioptic amorphous alloy was used.

Table 2 - On the other hand, only Example 4 has the structure shown in FIG. Instead of IO, a magnetic head made of iron-aluminum-silicon alloy (Sendas I.) was used.

〔Effect of the invention〕

As is clear from these Tables 1 and 2, Comparative Example 1
As in, the coercive force Hc of the magnetic disk and the residual! <13
$! Even if the density Br is high and the surface roughness Ra is small, if the gap length gl of the pillar head is too long or the saturation magnetic flux density B3 of the magnetic material placed near the magnetic gap is small, the aforementioned " The features of the 1-air disk are not fully exhibited, and as a result, magnetic properties such as head output, S/N, Ds, and peak shift are poor.

Also, as shown in comparison υ12, what! When using a magnetic head with a short gap length gl and a large saturation magnetic flux density B3 of the Yu 11 body placed near the magnetic gap, the magnetic disk retains force He and residual f; Tato 1rLX;
If the Br is low or the surface roughness Ra is large, the H of the magnetic head will not be sufficiently exhibited, and in this case as well, various magnetic properties will be poor.

On the other hand, as in Examples 1 to 4, the coercive force of the magnetic disk is 1200 or more, the residual wm flux density Br is 1200 Gauss or more, and the surface roughness Ra of the magnetic layer is 0.
．． If a magnetic head with a gap length of 0.15 to 0.4 μm is used, and the saturation magnetic flux density Bs of the magnetic material placed near the magnetic gap is 7000 Gauss or more, the magnetic The features of the disk and magnetic head are fully demonstrated.

As a result, the head output was 9.35 mV or more, and the S/N was 6.
Excellent electromagnetic conversion characteristics with +DS@ of 5 dB or more, 54 KBPI or more, and peak shift of 13 ns or less can be obtained.

Note that when the coercive force He of the magnetic layer exceeds 2000 Oe, the saturation magnetic flux density of the core material of the magnetic head is 700 Oe.
Even if it exceeds 0 Gauss, a sufficient recording magnetic field cannot be generated and recording will be insufficient, so the coercive force Hc should be 1200 to 200.
It is necessary to regulate it within the range of 0 oersteds. Also remaining W
If the stone bundle density Br falls below 1200 Gauss, sufficient head output cannot be obtained due to the relationship with amplifier noise, so the lower limit value of the residual ffi*density Br must be set to 1200 Gauss and set at 1. If the surface roughness Ra of the magnetic layer becomes larger than 0.03 μm, the S/N will particularly decrease.
a needs to be regulated to 0.03 μm or less. In this way, it is desirable that the surface roughness Ra is as small as possible, but considering the agglomeration of magnetic powder and the size of fillers, etc., the surface roughness Ra
In order to reduce the thickness to 0.007 μm or less, it costs ¥1.00 in mass production of magnetic recording media. There is a.

On the other hand, if the saturation magnetic flux density of the magnetic material near the magnetic gap of the magnetic head is not 7000 Gauss or more, the magnetic core will be saturated depending on the amount of i1m current to the magnetic head.
When the characteristics of the magnetic recording medium are not fully exhibited, and when the gap length is shorter than 0.15 μm, the head output becomes low, while when the gap length is longer than 0.4 μm. The value will drop and high-density recording will no longer be possible. Therefore, the gap length must be regulated within the range of 0.15 to 0.4 μm.

In the magnetic head according to the embodiment of the present invention, a magnetic gear,
A so-called multilayer structure in which the magnetic material placed near the disk is composed of two or more magnetic thin films, and a non-Kl thin film is interposed between the magnetic thin films (magnetic head used in Examples 1 to 3). The magnetic material is an iron-aluminum-silicon alloy (
Compared to the (■ air head) used in Example 4, it has less air loss due to the generation of eddy currents, so it is superior in characteristics such as D and value. It is especially prized as a magnetic head for high-density recording.

As mentioned above, the present invention relates to the coercive force of a magnetic recording medium, which has an important correlation in terms of characteristics such as electromagnetic conversion characteristics.

By regulating the residual magnetic flux density, the roughness of the end surface of the magnetic layer, the saturation magnetic flux density of the magnetic material near the magnetic gap in the magnetic head, and the gap length within specific ranges, high-density recording is possible and high output is achieved. It is possible to provide a portable and highly reliable magnetic recording/reproducing device.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a magnetic hesode used in an embodiment of the present invention, and FIG. 2 is an enlarged vertical cross-sectional view of a magnetic recording medium used in the same embodiment. 1...1st core half day off, 2...2nd core half day off, 4
...First core base, 5...Magnetic gap, 6.
...First laminated magnetic film, 7...First nonmagnetic thin film, 8
...First magnetic thin film, 9...Second core substrate, 10
... second laminated magnetic film, 11 ... second nonmagnetic thin film, 12 ... second magnetic thin film, 21 ... nonmagnetic support, 22 ... magnetic layer. t: "41 Koryotei Ine 2: Kaya 2] Ryohei 4 To 4; Kaya 1 Ko T group 4 杢 510,000 扼 3 Kaiya' de nfu 0 /Z: IJznIlyJ7 [ 2I: Non-magnetic Ise ax z2 : X*, IsJ

Claims (3)

[Claims] (1) A magnetic recording medium in which a magnetic layer in which ferromagnetic fine particles are dispersed in a non-magnetic binder is formed on a non-magnetic support, and a signal is recorded and reproduced by sliding contact with the magnetic layer of the magnetic recording medium. In a magnetic recording and reproducing apparatus equipped with a magnetic head for performing
The coercive force of the magnetic layer of the magnetic recording medium is 1200 to 200.
0 oersted, a residual magnetic flux density of 1200 Gauss or more, a surface roughness of 0.03 μm or less, and a magnetic head having a high saturation magnetic flux density near the magnetic gap of 7000 Gauss or more. 1. A magnetic recording/reproducing device characterized in that the length of the magnetic gap in the running direction of the magnetic recording medium is regulated to a range of 0.15 to 0.4 μm. (2) The magnetic recording and reproducing device according to claim (1), wherein the magnetic body disposed near the magnetic gap of the magnetic head is an amorphous alloy having high magnetic permeability. Device. (3) In claim (1) or (2), the magnetic body disposed near the magnetic gap of the magnetic head is composed of two or more layers of magnetic thin films, and an intermediate layer between the magnetic thin films is provided. A magnetic recording/reproducing device characterized in that a nonmagnetic thin film is interposed.