JPH0869608A - Magnetic head and magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE: To improve the recording and reproducing characteristics of a diagonally anisotropic magnetic recording medium. CONSTITUTION: This ring type magnetic head of a metal-in-gap type constitutes a magnetic circuit having a gap by disposing a first magnetic core half body formed to deposit a soft magnetic metallic film on a ferromagnetic ferrite surface and a second magnetic core half body opposite to each other. The average film thickness of the soft magnetic metallic film 3a deposited on the gap forming surface of the first magnetic core half body is >=1.5μm and the average film thickness of the soft magnetic metallic film 3b deposited on the gap forming surface of the second magnetic core half body is made larger than twice the average film thickness of the soft magnetic metallic film deposited on the gap forming surface of the first magnetic core half body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-capacity magnetic recording / reproducing apparatus excellent in high-density recording / reproducing characteristics and a ring type magnetic head mounted therein.

[0002]

2. Description of the Related Art At present, a magnetic recording / reproducing apparatus tends to have a high recording density in order to realize a small size and a large capacity.
In order to deal with this, in the fields of magnetic recording media and magnetic heads, much research and development has been advanced in order to improve the recording / reproducing characteristics in the high recording density region.

In order to improve the recording / reproducing resolution in a high recording density region of a magnetic recording medium, it is necessary to increase the remanent magnetization, increase the coercive force corresponding to the magnitude of the remanent magnetization, and thin the magnetic layer. is there. In particular, from the above viewpoint, a thin film magnetic recording medium manufactured by a vacuum deposition method, a sputtering method, an ion plating method, or the like is drawing attention as a material that exceeds the limit of the conventional coating type magnetic recording medium.

On the other hand, in the magnetic head, in order to improve the recording ability in response to the high coercive force of the magnetic recording medium,
Development of a soft magnetic material having a high saturation magnetic flux density has been advanced, and a ring type magnetic head using a soft magnetic material having a saturation magnetic flux density of more than 1.5 T has already been put into practical use.

As a typical example of the thin film type magnetic recording medium, Hi is used.
There is a vapor deposition tape that has been put to practical use for 8 type VTRs.
The characteristic of this magnetic recording medium is that, unlike the conventional longitudinal recording medium, the easy magnetization axis is inclined with respect to the film normal of the magnetic layer. That is, the axis of easy magnetization is not in the film surface or in the film normal direction, but is in a direction oblique to the film normal in the normal surface including the longitudinal direction of the tape. For example, in the commercially available vapor-deposited tape for Hi8 type VTR, the easy axis of magnetization is inclined by about 70 ° from the normal to the film in the normal plane including the longitudinal direction of the tape. The magnetization recorded by the ring-type magnetic head remains in the direction of the easy axis of magnetization that is obliquely inclined, and forms a magnetization mode different from that of conventional longitudinal recording. By forming such a diagonal magnetization mode,
The high recording density characteristics are remarkably improved as compared with the longitudinal recording medium.

As the superiority of the oblique magnetization mode to the longitudinal magnetization mode has become clear, in recent years, even in the conventional coating type medium, attempts have been made to realize the oblique magnetization mode and improve the high recording density characteristics. .

In order to produce the vapor deposition tape having the so-called oblique anisotropy with high productivity, a continuous vacuum vapor deposition apparatus using a cylindrical roller system is used while moving a long polymer substrate. The magnetic layer may be continuously vapor-deposited thereon. An example of the manufacturing method will be described below with reference to FIG. FIG. 13 shows an example of the internal structure of a vacuum vapor deposition device for producing a vapor deposition tape. While the substrate 21 made of a long polymer material unwound from the supply roll 29 travels along the cylindrical can 27 in the direction of the arrow 28, evaporated atoms 34 evaporated from the evaporation source 33 adhere to the substrate 21. Then, the magnetic layer is formed. For the evaporation source 33, for example, Co and Ni
When manufacturing a vapor deposition tape for a high band 8 mm VTR containing, as a main component, and O, an alloy of Co and Ni is filled. Although there are methods such as resistance heating and induction heating as vapor deposition methods, electron beam vapor deposition is particularly suitable for vaporizing refractory metals such as Co at a high vaporization rate. 31
A and 31B are shielding plates provided to prevent unnecessary evaporated atoms from adhering to the substrate. With this shielding plate, the incident angle of the vaporized atoms to the substrate is set in a region between the value φ _{i at the} film formation start portion and the value φ _{f at} the film formation end portion with respect to the substrate normal. The inclination direction of the easy axis of magnetization of the deposited magnetic layer is mainly controlled by the above settings of φ _i and φ _f . Conventionally, when manufacturing a vapor deposition tape or the like for a Hi8 system VTR, it is considered desirable that the incident angle of vaporized atoms to the substrate at the film formation start portion is 90 ° with respect to the substrate normal. The shield plate 31A is not used. Reference numeral 32 is an oxygen inlet for introducing oxygen into the vacuum chamber during vapor deposition. Further, 30 is a winding roll for winding the substrate 21 on which the magnetic layer is formed.

[0008]

[Problems to be Solved by the Invention] In the future, the magnetic recording / reproducing apparatus will become smaller and larger in capacity. Therefore, in a magnetic recording / reproducing system using a combination of a magnetic head and a magnetic recording medium, it is required to achieve higher S / N than ever before, especially in a high linear recording density region.

[0009]

In order to solve the above problems, the present invention has improved the structure of a ring type magnetic head and a magnetic recording / reproducing apparatus to improve the magnetic recording / reproducing performance in an oblique anisotropic magnetic recording medium. It is realized by the following configuration.

As the first structure of the ring type magnetic head, the first magnetic core half body and the second magnetic core half body formed by coating the surface of the ferromagnetic ferrite with the metal soft magnetic film are opposed to each other. In a metal-in-gap type ring type magnetic head that forms a magnetic circuit having a gap, the average thickness of the metal soft magnetic film deposited on the gap forming surface of the first magnetic core half is 1.5 μm or more, And the average film thickness of the metal soft magnetic film deposited on the gap forming surface of the second magnetic core half is equal to the average film thickness of the metal soft magnetic film deposited on the gap forming surface of the first magnetic core half. It is more than twice, and more preferably, the metal having the saturation magnetic flux density of the metal soft magnetic film adhered to the gap forming surface of the first magnetic core half is adhered to the gap forming surface of the second magnetic core half. Being smaller than the saturation magnetic flux density of the soft magnetic film And butterflies.

A second configuration is a ring-type magnetic head that constitutes a magnetic circuit having a gap by making the first magnetic core half body and the second magnetic core half body made of a ferromagnetic material face each other. Of the magnetic material forming the gap forming surface of the magnetic core half body and its vicinity is smaller than the saturation magnetic flux density of the magnetic material forming the gap forming surface of the second magnetic core half and its vicinity, and The magnetic path cross-sectional area of the gap forming surface of the first magnetic core half is smaller than the magnetic path cross-sectional area of the gap forming surface of the second magnetic core half.

Further, as a third structure, a ring-type magnetic head for forming a magnetic circuit having a gap by facing the first magnetic core half body and the second magnetic core half body made of a ferromagnetic material, The magnetic material forming the gap forming surface of the magnetic core half body and its vicinity and the magnetic material forming the gap forming surface of the second magnetic core half body and its vicinity are composed mainly of a plurality of the same elements. Alternatively, the magnetic material forming the gap forming surface of the first magnetic core half and the vicinity thereof is added to the elements constituting the magnetic material forming the gap forming surface of the second magnetic core half and the vicinity of B and C. , N, and O, and the saturation magnetic flux density of the magnetic material of the magnetic material forming the gap forming surface of the first magnetic core half body and the vicinity thereof is the second magnetic material. Wherein the gap forming surface of core half and smaller than the saturation magnetic flux density of the magnetic material constituting the neighborhood.

As for the structure of the magnetic recording / reproducing apparatus, a magnetic recording medium having an easy axis of magnetization inclined with respect to the film normal of the magnetic layer is used for the ring type magnetic head having the above-mentioned first to third structures. A magnetic recording / reproducing apparatus for recording a signal using at least one selected magnetic head, the magnetic head being in a normal plane of a magnetic layer of a magnetic recording medium including a relative moving direction of the magnetic head and the magnetic recording medium in a recording process. The magnetic field near the leading edge of the magnetic recording medium and the easy axis of magnetization of the magnetic recording medium are inclined to the same side with respect to the film normal of the magnetic layer of the magnetic recording medium, and the relative movement of the magnetic head and the magnetic recording medium during the recording process. In the direction, the first magnetic core half body of the magnetic head is on the leading side, and the second magnetic core half body is on the trailing side.

[0014]

In general, in the process of recording a magnetic recording medium having a high coercive force by using a ring type magnetic head, the head is required to have a sufficient recording magnetic field for sufficiently reversing the magnetization of the high coercive force medium. That is, the higher the saturation magnetic flux density of the soft magnetic material forming the head, the higher the magnetic reversal ability, and thus the higher the reproduction output can be obtained, but at the time when the sufficient magnetic reversal ability with respect to the coercive force of the medium is realized. It is considered that even if the saturation magnetic flux density of the head material is further increased, the remarkable improvement of the reproduction output can no longer be expected.

On the other hand, the inventors of the present invention used a ring-type magnetic head having a recording magnetic field asymmetric with respect to the center line of the head gap and having a steeper gradient on the trailing edge side in recording / reproducing of an oblique anisotropic magnetic recording medium. The recording magnetic field near the leading edge of the ring type magnetic head and the easy axis of magnetization of the medium in the normal plane of the medium magnetic layer used and including the relative moving direction of the ring type magnetic head and the oblique anisotropic magnetic recording medium during recording. It has been found that by recording with the configuration shown in FIG. 12 in which and are inclined on the same side with respect to the film normal of the medium magnetic layer, the reproduction output is remarkably improved as compared with the conventional case. In FIG. 12, the ring type magnetic head shows only the vicinity of the leading edge 15 and the trailing edge 16 with the gap 6 interposed therebetween.

When the head has a saturation magnetic flux density sufficient for reversing the magnetization of the magnetic recording medium, the amount of magnetization remaining in the inter-transition region 26 can be sufficiently saturated by the conventional head. . On the other hand, the magnetic transition region 2
5, the behavior of the configuration of FIG. 12 is different from the conventional one. In the configuration of FIG. 12, the rate of decrease of the medium magnetization easy axis direction component of the recording magnetic field 18 from the vicinity of the gap center line 17 to the trailing edge side is steep. With such a recording magnetic field 18, the recording magnetization by the recording magnetic field on the leading side is promptly demagnetized or magnetized by the recording magnetic field on the trailing side, which is steeper than the conventional head. Therefore, the magnetic layer 20
It is considered that a narrower magnetic transition region 25 is realized and the reproduction output is increased particularly in the high linear recording density region as compared with the conventional configuration.

In order to obtain the above-described recording mechanism, the ring-type magnetic head is provided in the normal plane of the medium magnetic layer including the relative movement direction of the ring-type magnetic head and the oblique anisotropic magnetic recording medium during recording. It is necessary that the recording magnetic field near the leading edge and the easy axis of magnetization of the medium are inclined on the same side with respect to the film normal of the medium magnetic layer. In other words, the direction of the recording magnetic field near the leading edge is close to the easy axis of magnetization of the medium, and conversely, the direction of the recording magnetic field near the trailing edge is close to the hard axis direction of the medium. It is not necessary to exactly match the inclination direction of the recording magnetic field with the inclination direction of the easy magnetization axis of the oblique anisotropic medium. In the current VTR, the rotary head scans a little obliquely with respect to the length direction of the magnetic tape. For example, in the Hi8 system VTR, an angle of about 5 ° is formed with respect to the length direction of the magnetic tape. The head is scanned in the direction. However, even in the configuration like the VTR, the inclination direction of the recording magnetic field near the leading edge is close to the inclination direction of the easy axis of magnetization of the medium, and conversely, the inclination direction of the recording magnetic field near the trailing edge is difficult for the medium. With the configuration close to the axial direction, the recording mechanism of the present invention can be sufficiently realized and the recording / reproducing characteristics can be improved.

On the other hand, contrary to the structure of the present invention, the trailing of the ring-type magnetic head is within the normal plane of the medium magnetic layer including the relative movement direction of the ring-type magnetic head and the oblique anisotropic magnetic recording medium during recording. When the recording magnetic field near the edge and the easy axis of magnetization of the medium are inclined on the same side with respect to the film normal of the medium magnetic layer, the recording mechanism of the present invention as described above is realized. It is not possible. In this case, since the inclination direction of the recording magnetic field on the trailing side is close to the easy axis direction of the medium, as the recording wavelength becomes shorter, the recording demagnetization is more likely to occur as in the case of the conventional longitudinal recording. Linear recording density characteristics cannot be obtained.

According to the present invention, a ring type magnetic head having a recording magnetic field asymmetric with respect to the center line of the head gap and having a steeper gradient on the trailing edge side is formed by any of the following three components. Will be realized.

The first element is a magnetic material having a gap in which a first magnetic core half body and a second magnetic core half body formed by coating a metal soft magnetic film on the surface of a ferromagnetic ferrite are opposed to each other to have a gap. In a ring-type magnetic head of metal-in-gap type (hereinafter referred to as MIG type) forming a circuit, the average thickness of the metal soft magnetic film deposited on the gap forming surface of the first magnetic core half is the first. In a head having a structure smaller than the average film thickness of the metal soft magnetic film deposited on the gap forming surface of the second magnetic core half body, it is realized by setting the first magnetic core half body on the leading side.

In this structure, the thickness difference between the metal soft magnetic films of both magnetic core halves is made sufficiently large so that the portion near the gap in the first magnetic core half on the leading side is more magnetic than the trailing side. Saturation is easily reached, and a sharper asymmetric magnetic field is obtained on the trailing side with respect to the gap centerline.

The second element is a ring-type magnetic head which constitutes a magnetic circuit having a gap by making the first magnetic core half body and the second magnetic core half body made of a ferromagnetic material face each other. Of the magnetic material forming the gap forming surface of the magnetic core half body and its vicinity is smaller than the saturation magnetic flux density of the magnetic material forming the gap forming surface of the second magnetic core half body and its vicinity. In the head having the same, it is also realized by setting the first magnetic core half body on the leading side.

Also in this structure, by sufficiently increasing the saturation magnetic flux density difference between the metal soft magnetic films of the two magnetic core halves,
The portion near the gap in the first magnetic core half on the leading side is more likely to reach magnetic saturation than on the trailing side, and a sharper asymmetric magnetic field is obtained on the trailing side with respect to the gap centerline.

The third element is a ring-type magnetic head which constitutes a magnetic circuit having a gap by making the first magnetic core half body and the second magnetic core half body made of a ferromagnetic material face each other. The magnetic path cross-sectional area of the gap forming surface of the magnetic core half body is smaller than the magnetic path cross-sectional area of the gap forming surface of the second magnetic core half body. It is also realized by

Also in this structure, the portion near the gap in the first magnetic core half on the leading side is more likely to reach magnetic saturation than on the trailing side, and a sharper asymmetric magnetic field is generated on the trailing side with respect to the gap centerline. The effect obtained is recognized.

However, among the above three elements, the effect of obtaining a steeper asymmetric magnetic field on the trailing side with respect to the gap center line is the smallest in the third constituent element, and the effect of the present invention is sufficiently obtained by itself. It's difficult. For this reason, it is usually preferable to realize the third element at the same time as the second element. Alternatively, a MIG type head may be realized simultaneously with the first element.

For the MIG type head, 1
If the first element and the second element are realized at the same time, generally, the effect of the present invention is more remarkable than in the case where each of them is realized alone, which is more preferable. Further, if the third element is also incorporated and the three elements are realized at the same time, the effect of the present invention can be obtained more remarkably.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, a ring type magnetic head having the first to third structures described in the section of means for solving the problems and a commercially available VTR are remodeled and these ring type magnetic heads are modified. A magnetic recording / reproducing apparatus equipped with a head will be described below. As the magnetic recording medium, an oblique anisotropic vapor deposition tape produced by a continuous vapor deposition device was used.

(Structural Example of Magnetic Recording Medium) First, magnetic properties suitable for the manufacturing method of the magnetic recording medium and the structure of the present invention will be described with reference to FIG. In this embodiment, FIG.
An example in which a vapor deposition tape having a magnetic layer containing Co and O as main components in which the easy axis of magnetization is inclined with respect to the film normal line was produced by using the continuous vapor deposition apparatus shown in 3 and studied was described.

When forming the magnetic layer, a substrate 21 made of a polymer material is provided along the surface of a cylindrical can 27 with an arrow 2
Run in the 8 direction. As the substrate 21, a polyethylene terephthalate film, a polyethylene naphthalate film, a polyimide film, a polyamide film,
Any of those generally used for magnetic tapes such as polyetherimide film and polycarbonate film can be used. In the study in this example, a polyethylene terephthalate film having a thickness of 7 μm was used.

The evaporation source 33 is filled with a metal or alloy material forming the magnetic layer. Usually, Co-Ni, Co-Cr, and Co- which are suitable as magnetic layers for thin-film magnetic recording media
Co-based alloys such as Ni-Cr and Co-Pt are filled. In this example, a magnetic tape having a magnetic layer containing Co and O as the main components was examined, so the evaporation source 33 was filled with Co. At this time, a magnetic layer containing Co and O as main components is formed by performing reactive vapor deposition while introducing oxygen into the vacuum chamber from the oxygen inlet 32 during film formation.

Shielding plates 31A and 31B are arranged between the evaporation source 33 and the cylindrical can 27. Evaporated atoms 34 are deposited on the substrate 21 through the opening of the shield plate.

Φ _i and φ _f are incident angles of vaporized atoms to the substrate 21 at the film formation start portion and the film formation end portion of the magnetic layer, respectively. Controlling the values of φ _i and φ _f is very important in controlling the inclination direction and orientation of the easy axis of magnetization of the magnetic layer described below.

As shown in FIG. 12, in the magnetic recording medium having oblique anisotropy used in the structure of the present invention, the angle formed by the easy axis 22 of the magnetization and the film normal 23 is β. Here, β is a value obtained without correcting the influence of the demagnetizing field in a sample having a sufficiently large area compared to the thickness of the magnetic layer and having a demagnetizing field coefficient in the film normal direction of almost 1 due to the shape. To do. In order to sufficiently obtain the effect of the structure of the present invention, β of the magnetic recording medium used is preferably not less than 50 ° and not more than 85 °, not limited to the vapor deposition tape produced by the above-mentioned manufacturing method. If β is 85 ° or more, the easy axis of magnetization 22
Is too close to the film surface, it is difficult to form the oblique magnetization mode during recording. That is, like the conventional longitudinal recording, as the recording wavelength becomes shorter, the recording magnetic field on the trailing side is more likely to cause the recording demagnetization, and the excellent high linear recording density characteristic cannot be obtained. On the other hand, when β is 50 ° or less, the easy axis 22 is too close to the film normal, so that the recording magnetic field on the trailing side easily causes demagnetization, which makes it difficult to realize an ideal oblique magnetization mode.

Further, in order to sufficiently obtain the effect of the constitution of the present invention, the magnetic recording medium used must have a high orientation and excellent magnetic characteristics. In order to obtain the effect of realizing a narrow magnetic transition width by the recording mechanism of the present invention, the resolution of the magnetic recording medium itself that determines the limit of the magnetic transition width must be high. When a magnetic recording medium having insufficient orientation and large anisotropic dispersion is used, the width of the magnetic transition is limited by the resolution of the medium itself before the effect of the constitution of the present invention is obtained. On the other hand, the effect of the present invention is more remarkably obtained when a medium having high orientation and small anisotropic dispersion is used. From the above viewpoint, according to the studies by the present inventors, the magnetic characteristics of the magnetic recording medium include a coercive force of 80 kA / m or more in the easy axis direction and a uniaxial anisotropy constant of 10 ⁵ J / m ³
The above is preferable. In the vapor deposition tape produced by the manufacturing apparatus shown in FIG. 13, φ _i and φ _f are set from the viewpoint of obtaining an appropriate magnetization easy axis direction β and producing a highly oriented vapor deposition tape with little anisotropic dispersion. Proper setting is important. In the present embodiment, in the vapor deposition tape containing Co and O as the main components, which is manufactured by using the manufacturing apparatus shown in FIG. 13, β is about 75 °, coercive force in the easy axis direction is about 145 kA / m, and uniaxial. Anisotropy constant is about 2.8 × 10 ⁵ J / m
A value of ³ has been realized. The saturation magnetization of this vapor deposition tape is about 650 kA / m, and the film thickness of the magnetic layer is about 100 nm.

The vapor-deposited tape produced by the above method was provided with a carbon protective film of about 10 nm thickness and a lubricant layer of several nm thickness on the magnetic film side for use in the magnetic recording / reproducing apparatus in this embodiment. A back coat layer having a thickness of 0.5 μm was formed on the back surface. After that, it was cut into an appropriate width and length, and inserted into a commercially available cassette for use.

(First Structural Example of Ring Type Magnetic Head) Next, a structural example of the ring type magnetic head of the present invention will be described. First, as a first configuration, a magnetic circuit having a gap is formed by facing a first magnetic core half body and a second magnetic core half body formed by coating a metal soft magnetic film on a ferromagnetic ferrite surface. In the MIG type ring magnetic head, the average film thickness of the metal soft magnetic film deposited on the gap forming surface of the second magnetic core half was deposited on the gap forming surface of the first magnetic core half. A ring type magnetic head having a thickness larger than the average thickness of the metal soft magnetic film will be described in detail.

FIG. 1 shows an example of the MIG type ring type magnetic head having the first structure. Figure 1 (a)
FIG. 1B is a diagram showing a configuration example of the core cross section in the gap length direction 7 in the medium sliding surface of the ring type magnetic head. According to the configuration of the present invention, in the recording process, the first magnetic core half body is used as the leading side and the second magnetic core half body is used as the trailing side. Where the first
The thickness of the metal soft magnetic films 3a and 3b deposited on the gap forming surfaces of the magnetic core half body 1 and the second magnetic core half body 2 of
It shall be measured in the gap length direction 7 of the head, are respectively represented by d _a, d _b in FIG. 1 (b). The average thickness of the metal soft magnetic film deposited on the gap forming face is represented by an average value in the gap width direction 8 of d _a or d _b. As shown in the figure, the average thickness of the metal soft magnetic film deposited on the gap forming surface of the second magnetic core half is equal to the average thickness of the metal soft magnetic film deposited on the gap forming surface of the first magnetic core half. With the configuration larger than the average film thickness of the film, the ring magnetic head of the present invention can be obtained in which the recording magnetic field is asymmetric with respect to the center line of the head gap and has a steeper gradient on the trailing edge side.

In the structure of FIG. 1, the metal soft magnetic film 3a (saturation magnetic flux density is B _sa ) deposited on the first magnetic core half body and the metal soft magnetic film 3a deposited on the second magnetic core half body. If each of the soft magnetic films 3b (the saturation magnetic flux density is B _sb ) is made of a different kind of magnetic material and the relationship B _sb > B _sa is satisfied, the recording magnetic field becomes more asymmetric and the magnetic field gradient on the trailing edge side increases. Is more preferable because it increases.

Here, in order to realize sufficient recording ability for a highly oriented obliquely anisotropic medium having a high coercive force and to exert the effects of the present invention, the recording magnetic field on the leading edge side is It is necessary to have sufficient magnetization reversal ability. Therefore, when recording on an oblique anisotropic medium with a high coercive force of 80 kA / m or more in the direction of the easy axis as described above, the first magnetic core half body on the leading side is coated with the recording medium. The saturation magnetic flux density B _sa of the metal soft magnetic film 3a is preferably at least 0.8T or more. When B _sa is smaller than 0.8 T, the recording magnetic field on the leading side cannot sufficiently reverse the magnetization of the medium, so that the effect of the present invention is difficult to obtain. Alternatively, it requires a very large exciting current, which is not preferable in terms of power consumption of the device. Further, even when B _sa is larger than 0.8 T, the magnetization reversal ability is reduced and the effect of the present invention is obtained as the average film thickness of the metal soft magnetic film 3a deposited on the first magnetic core half is smaller. It will be difficult. According to the study by the present inventors, in order to obtain a sufficient magnetization reversal ability, the average thickness of the metal soft magnetic film 3a deposited on the first magnetic core half body should be at least 1.5 μm or more. is necessary.

From the above viewpoints, examples of the configuration that is not preferable include the following configuration examples. Ie MI
In the configuration of the G type head, the metal soft magnetic film having a high saturation magnetic flux density is formed only on the gap forming surface of the second magnetic core half body, and the gap forming surface of the second magnetic core half body is made of ferrite. With this structure, the ring magnetic head having the recording magnetic field asymmetric with respect to the center line of the head gap and having a steeper gradient on the trailing edge side can be realized most simply. However, in this case, since the saturation magnetic flux density of the ferrite forming the leading edge is as small as about 0.5 T, the magnetization reversal ability due to the magnetic field on the leading side is lacking, and the effect of the present invention is hardly obtained from the above viewpoint.

In order to realize the recording mechanism of the present invention, the recording magnetic field becomes asymmetric with respect to the gap center line,
It is necessary to have a steeper slope on the trailing side. From this point of view, the saturation magnetic flux density B _sb of the metal soft magnetic film 3b deposited on the second magnetic core half is about the same as the saturation magnetic flux density B _sa of the metal soft magnetic film 3a of the first magnetic core half. In this case, in order to realize the above-mentioned asymmetric recording magnetic field and obtain the effect of the present invention sufficiently, the metal soft magnetic film 3b deposited on the gap forming surface of the second magnetic core half on the trailing side. It is necessary to make the average film thickness of 2 above twice the average film thickness of the metal soft magnetic film 3a deposited on the gap forming surface of the first magnetic core half. When the average film thickness of the metal soft magnetic film 3b is not more than twice the average film thickness of the metal soft magnetic film 3a, the asymmetry of the recording magnetic field becomes insufficient, and the effect of the present invention is difficult to obtain. As described above, since the average film thickness of the metal soft magnetic film 3a needs to be 1.5 μm or more, the metal soft magnetic film 3b
The average film thickness of is at least 3 μm or more. On the other hand, if the average film thickness of the metal soft magnetic film 3b is too large, high-frequency loss due to eddy current occurs. It is important to get the thickness.

Further, in the above structure, the saturation magnetic flux density B _sb of the metal soft magnetic film 3b deposited on the second magnetic core half is equal to the saturation magnetic flux density B _sa of the metal soft magnetic film 3a of the first magnetic core half. If it is made larger than this, in order to increase the asymmetry of the recording magnetic field and obtain the effect of the recording mechanism of the present invention more significantly, it is preferable to make B _sb 1.2 times or more larger than B _sa . When B _sb is smaller than 1.2 times B _sa , it is difficult to obtain the effect of increasing the asymmetry of the recording magnetic field, and it is difficult to recognize the improvement of the recording / reproducing characteristics.

The gap length of the head can also be a factor for increasing the asymmetry of the recording magnetic field to obtain the effect of the recording mechanism of the present invention more remarkably. The smaller the gap length, the greater the asymmetry of the recording magnetic field obtained by the configuration of the present invention.
More preferable recording / reproducing characteristics can be obtained. According to the study by the present inventors, it has been confirmed that the output difference with respect to the head having the conventional configuration remarkably increases particularly in the region where the gap length is 0.22 μm or less. In the future, it is expected that the magnetic recording / reproducing apparatus will have a higher recording density and that the one having the shortest recording wavelength of 0.5 μm or less will become the mainstream. Therefore, from the viewpoint of reproducing gap loss, the gap length is small, preferably 0.22μ.
It is preferably configured to be m or less.

The above contents can be confirmed experimentally from, for example, measurement results of recording / reproducing characteristics using a magnetic recording / reproducing apparatus or a drum tester of the present invention described later.

As the metal soft magnetic film having a saturation magnetic flux density of 0.8 T or more, for example, a Co type amorphous alloy film or a sendust film is suitable. Further, a metallic soft magnetic film having a higher saturation magnetic flux density, such as a Co type superstructure nitride alloy film having a saturation magnetic flux density of more than 1.3 T or an Fe type microcrystalline film having a saturation magnetic flux density of more than 1.5 T, may be used.

The saturation magnetic flux density B _sb of the metal soft magnetic film 3b deposited on the second magnetic core half is set to be higher than the saturation magnetic flux density B _sa of the metal soft magnetic film 3a of the first magnetic core half. In the case of simultaneously realizing the above, for example, a Co-based amorphous alloy film or a sendust film having a saturation magnetic flux density of about 1 T is used for the metal soft magnetic film 3a of the first magnetic core half and the second magnetic core half is used. If a Co-based superstructure nitride film having a higher saturation magnetic flux density or a Fe-based microcrystalline film is used for the metal soft magnetic film 3b deposited on B, a structure in which B _sb is 1.2 times or more larger than B _sa can be realized. it can.

When the head shown in FIG. 1 is used especially in a magnetic recording / reproducing apparatus such as a VTR, an azimuth angle of 10 is used to reduce the influence of crosstalk between adjacent tracks.
May be provided. By forming the azimuth angle 10, the gap 6 is formed in a direction inclined with respect to the direction of relative movement between the head and the medium. Therefore, the azimuth angle is the same as the scanning angle of the rotary head in the VTR with respect to the lengthwise direction of the magnetic tape, and the inclination direction of the recording magnetic field near the leading edge of the ring type magnetic head and the inclination direction of the easy axis of magnetization of the oblique anisotropic medium. It becomes a factor that does not exactly match with. However, even if the azimuth angle is set within a practical range, the inclination direction of the recording magnetic field near the leading edge is close to the inclination direction of the easy axis of magnetization of the medium, and conversely, the inclination direction of the recording magnetic field near the trailing edge. With a structure close to the hard axis direction of the medium, the recording mechanism of the present invention can be sufficiently realized and the recording / reproducing characteristics can be improved.

2 and 3 are similar to FIG. 1 in that the first is formed by depositing a metal soft magnetic film on the surface of the ferromagnetic ferrite.
A magnetic core half body and a second magnetic core half body are opposed to each other to form a magnetic circuit having a gap. A MIG-type ring magnetic head, wherein a metal deposited on a gap forming surface of the second magnetic core half body. A configuration example different from that of FIG. 1 is shown for a ring type magnetic head in which the average thickness of the soft magnetic film is larger than the average thickness of the metal soft magnetic film deposited on the gap forming surface of the first magnetic core half body. It is a thing. Each of (a) shows a medium sliding surface of the ring type magnetic head, and (b) shows an example of a core cross section in the gap length direction 7. The interface between the metal soft magnetic films 3a and 3b and the ferrite 4 is shown in FIG.
It is known that by forming the gap 6 in a non-parallel manner as described above, it is possible to reduce noise due to a reproduction signal from the pseudo gap formed by the nonmagnetic portion existing at the same interface. Also in the configurations shown in FIGS. 2 and 3, the average film thickness of the metal soft magnetic film 3a deposited on the first magnetic core half body is 1.5.
.mu.m or more and the average film thickness of the metal soft magnetic film 3b deposited on the second magnetic core half is twice the average film thickness of the metal soft magnetic film 3a deposited on the first magnetic core half. The effect of the present invention can be obtained similarly to the configuration of FIG. Also, the effect of increasing the asymmetry of the recording magnetic field by increasing B _sb to 1.2 times or more of B _sa can be obtained as in the configuration of FIG.

(Second Configuration Example of Ring-Type Magnetic Head) Next, as a second configuration, a first magnetic core half body and a second magnetic core half body made of a ferromagnetic material are made to face each other to have a gap. A ring-type magnetic head that constitutes a magnetic circuit.
Of the magnetic material forming the gap forming surface of the magnetic core half body and its vicinity is smaller than the saturation magnetic flux density of the magnetic material forming the gap forming surface of the second magnetic core half and its vicinity, and A ring type magnetic head in which the magnetic path cross-sectional area of the gap forming surface of the first magnetic core half body is smaller than the magnetic path cross-sectional area of the gap forming surface of the second magnetic core half body will be described in detail.

An example of the laminated type ring type magnetic head having the above-mentioned second structure is shown in FIGS. FIGS. 4 and 5 are views showing a configuration example of a cross section of the core of the ring type magnetic head in FIG. 4A and a cross section of the core in the relative moving direction 14 of the head and the medium, respectively. According to the configuration of the present invention, in the recording process, the first magnetic core half body is used as the leading side and the second magnetic core half body is used as the trailing side. Here, the gap depth d _g is shown in FIGS. 2 and 3B. Generally, in the ring type magnetic head, the length of the gap forming surface of the first magnetic core half body in the gap width direction 8 is substantially equal to the length of the gap forming surface of the second magnetic core half body in the gap width direction 8. Is made. In such a case, the fact that the magnetic path cross-sectional area of the gap forming surface of the first magnetic core half is smaller than the magnetic path cross-sectional area of the gap forming surface of the second magnetic core half means that the gap depth d _g Can be understood to be determined by the magnetic path cross-sectional shape at the gap forming surface of the first magnetic core half body 1.

As shown in FIG. 4, such a structure has a first structure.
If the winding window 11 is provided only on the half of the magnetic core, the simplest implementation is possible. Also in the configuration in which the winding windows 11 are provided in both magnetic core halves, as shown in FIG.
It is possible to realize a configuration in which the magnetic path cross-sectional area of the gap forming surface of the magnetic core half body is smaller than the magnetic path cross-sectional area of the gap forming surface of the second magnetic core half body.

As already described in the section of the action, the magnetic path cross-sectional area of the gap forming surface of the first magnetic core half is smaller than the magnetic path cross-sectional area of the gap forming surface of the second magnetic core half. The characteristics alone are not sufficient to obtain a sharper asymmetric magnetic field on the trailing side with respect to the gap center line. In the ring type magnetic head having the second structure according to the present invention, the saturation magnetic flux density B _sb of the magnetic material forming the gap forming surface of the second magnetic core half body and its vicinity is determined by the gap forming surface of the first magnetic core half body. The magnetic flux cross-sectional area of the gap forming surface of the first magnetic core half is larger than the saturation magnetic flux density B _sa of the magnetic material forming the surface and its vicinity. By simultaneously realizing a structure smaller than the magnetic path cross-sectional area of, the effect of improving the recording / reproducing characteristics by the recording mechanism of the present invention is enhanced.

As a result, in comparison with the head having a structure in which B _sb is simply larger than B _sa , the reproduction output particularly in the high linear recording density region is increased and the effect of reducing the optimum recording current is obtained. This can contribute to low power consumption of the recording / reproducing device. For example, according to the result of recording and reproducing on the above-described oblique anisotropic vapor deposition tape, the optimum magnetomotive force for obtaining the maximum output at the recording wavelength of 0.5 μm is the MIG having a configuration in which B _sb is made larger than B _sa. About 0.4 AT _pp with type head
On the other hand, in the head that simultaneously realized the second head configuration, a small value of about 0.3 to 0.35 AT _pp or less was obtained by the magnetic core configuration shown in FIGS. 6 and 7.

In the second head structure as well as the first head structure, B _sa needs to be 0.8 T or more in order to sufficiently obtain the magnetization reversal ability by the head magnetic field on the leading side. Further, even when the difference between B _sb and B _sa is provided, in order to sufficiently obtain the asymmetry of the recording magnetic field, B _sb should be 1.2 times or more of B _sa as in the case of applying the first head configuration. It is preferable to increase the gap length to 0.22 μm or less.

Regarding the magnetic material forming the gap forming surfaces of the first magnetic core half body and the second magnetic core half body and the vicinity thereof, the Co type amorphous film and the sendust film are the same as in the first head structure. A metal soft magnetic film such as a Co-based superstructure nitride alloy film or a Fe-based microcrystalline film may be used.

The second head structure can be realized not only in the laminated type ring type magnetic head but also in the MIG type ring type magnetic head as shown in FIGS. 6 and 7, for example. In this case, in the first head structure, the average film thickness of the metal soft magnetic film deposited on the gap forming surface of the second magnetic core half body is deposited on the gap forming surface of the first magnetic core half body. By simultaneously realizing a structure larger than the average film thickness of the metal soft magnetic film, the recording magnetic field becomes more asymmetric and the magnetic field gradient on the trailing edge side becomes larger, so that more preferable recording / reproducing characteristics can be obtained.

(Third Configuration Example of Ring Type Magnetic Head) Next, as a third configuration, a first magnetic core half body and a second magnetic core half body made of a ferromagnetic material are made to face each other to have a gap. A ring-type magnetic head that constitutes a magnetic circuit.
The magnetic material forming the gap forming surface of the magnetic core half body and its vicinity and the magnetic material forming the gap forming surface of the second magnetic core half body and its vicinity are composed mainly of a plurality of the same elements. Alternatively, the magnetic material forming the gap forming surface of the first magnetic core half and the vicinity thereof is added to the elements constituting the magnetic material forming the gap forming surface of the second magnetic core half and the vicinity of B and C. , N, and O, and the saturation magnetic flux density of the magnetic material of the magnetic material forming the gap forming surface of the first magnetic core half body and its vicinity has the second magnetic core half A ring type magnetic head having a saturation magnetic flux density smaller than that of the magnetic material forming the gap forming surface of the body and its vicinity will be described in detail.

In the present invention, as a method for realizing a magnetic head that has a large magnetic field gradient on the trailing edge side and generates a recording magnetic field asymmetric with respect to the gap center line, the gap forming surface of the second magnetic core half body is used. And a saturation magnetic flux density B _sb of the magnetic material forming the vicinity thereof and a saturation magnetic flux density B _sa of the magnetic material forming the gap forming surface of the first magnetic core half body and its vicinity are proposed. However, in order to realize the above configuration, the first
When the magnetic material forming the gap forming surface of the magnetic core half body and its vicinity and the magnetic material forming the gap forming surface of the second magnetic core half body and its vicinity are composed of different kinds of soft metal magnetic films. Are often disadvantageous in terms of productivity. For example, when the metal soft magnetic film 3a in the first magnetic core half body and the metal soft magnetic film 3b in the second magnetic core half body are mainly composed of different elements, a completely different manufacturing apparatus or manufacturing May require conditions. Furthermore, if different metal soft magnetic films are manufactured using the same equipment, the constituent elements of each other will mix as impurities,
It can also cause deterioration of magnetic properties.

The third head structure is a structure for preventing the above-mentioned decrease in productivity, and the second soft magnetic film on the first magnetic core side and the second head structure are used.
It is proposed that the soft magnetic magnetic film on the core side is composed mainly of elements of the same kind and the composition ratio of the two is made different so that the saturation magnetic flux densities of both are made different.

Examples of the metal soft magnetic film suitable for such a structure include Fe-based and Co-based nitride films or oxide films produced by the reactive sputtering method. As a typical example, for a Fe-based nitride microcrystalline film, the saturation magnetic flux density of about 1 T to 1.6 T can be obtained by a simple operation such as changing the nitrogen thickness during sputtering in a region where good soft magnetic characteristics can be obtained. It is possible to change the range. From this range, a film having a high saturation magnetic flux density may be arranged on the second magnetic core side, and a film having a low saturation magnetic flux density may be arranged on the first magnetic core side. In this case, the main elements are the same, but only the composition ratio is different. Therefore, even when the first magnetic core half body and the second magnetic core half body are manufactured by the same apparatus, adverse effects on the magnetic characteristics due to mixing of impurities and the like are small. For example, it is possible to provide a manufacturing process which is very simple and has excellent reproducibility and productivity as compared with a structure in which different kinds of films such as sendust and Fe-based nitride microcrystalline film are arranged on the first and second magnetic cores, respectively. .

Further, the magnetic material forming the gap forming surface of the first magnetic core half body and its vicinity is changed to the element constituting the magnetic material forming the gap forming surface of the second magnetic core half body and its vicinity. When the magnetic material has a composition in which at least one element selected from B, C, N, and O is added, and the saturation magnetic flux density of the magnetic material forming the gap forming surface of the first magnetic core half body and the vicinity thereof is the second It may be smaller than the saturation magnetic flux density of the magnetic material forming the gap forming surface of the magnetic core half body and its vicinity.

These elements are the first in the sputtering method.
Can be easily added to the metal soft magnetic film on the magnetic core side, and the saturation magnetic flux density is smaller than that of the metal soft magnetic film on the second magnetic core side while maintaining good soft magnetic characteristics. can do. Further, since the addition amounts of these elements may be small, it is not necessary to make the main components of the metal soft magnetic film on the first magnetic core side and the metal soft magnetic film on the second core side largely different from each other. Therefore, even when the first magnetic core half body and the second magnetic core half body are manufactured by the same apparatus, the inclusion of impurities and the like is relatively small, and the manufacturing process is simple and excellent in reproducibility and productivity. Can be provided.

The above structure can be widely applied to various Fe-based and Co-based metal soft magnetic films having soft magnetic characteristics suitable for magnetic head materials. For example, already B,
It may be based on a metal soft magnetic film containing at least one element selected from C, N and O. In such a case, this metal soft magnetic film constitutes the vicinity of the gap on the second magnetic core side. Further, the metal soft magnetic film having a composition in which an element not contained in the metal soft magnetic film is selected from B, C, N and O may be formed near the gap on the first magnetic core side.

In order to realize the third head structure, both the metal soft magnetic film on the first magnetic core side and the metal soft magnetic film on the second magnetic core side are composed of plural kinds of films having different saturation magnetic flux densities. There is also a method of providing a difference in saturation magnetic flux densities of the metal soft magnetic films in both magnetic cores by forming a multilayer film and making the composition ratios in both magnetic cores different. An example of the structure of such a head is shown in FIGS. 8 and 9 are diagrams showing a configuration example of the medium sliding surface of the ring type magnetic head. As in FIGS. 1 to 7, the right side of the gap 6 is the first magnetic core half body and the left side is the second magnetic core half body. Shown as a magnetic core half. FIG. 8 shows an example of the structure of a laminated type head.
FIG. 9 shows a configuration example of the MIG type head.

For example, in the examples shown in FIGS. 8 and 9, the gap forming surface and its vicinity of the first magnetic core half body and the second magnetic core half body are composed of three layers of the metal soft magnetic film 3b and two layers. The metal soft magnetic film 3a is composed of a laminated film including a total of five layers. Here, it is assumed that the saturation magnetic flux density B _sb of the metal soft magnetic film 3b is higher than the saturation magnetic flux density B _sa of the metal soft magnetic film 3a. In this case, by making the layer thickness ratio of the metal soft magnetic film 3b on the second magnetic core side to the metal soft magnetic film 3a larger than the layer thickness ratio on the first magnetic core side, the second magnetic core side It is possible to make the saturation magnetic flux density of the metal soft magnetic film on the first magnetic core side higher than the saturation magnetic flux density of the metal soft magnetic film on the first magnetic core side.

For the metal soft magnetic film in the structure of FIGS. 8 and 9, for example, Fe-based and Co-based nitride films or oxide films produced by the reactive sputtering method are also suitable. With these films, the laminated film of the metal soft magnetic films 3a and 3b having different saturation magnetic flux densities can be easily manufactured by changing the nitrogen or oxygen thickness during film formation in a constant cycle.

The metal soft magnetic films 3a and 3b may have completely different compositions, but from the viewpoint of productivity, it is preferable to use the same element as the main component as described above.

Further, particularly when the metal soft magnetic films 3a and 3b have completely different compositions, the metal soft magnetic film 3 is used.
There may be a case where a battery effect due to a difference in work function between a and 3b occurs, and sufficient corrosion resistance cannot be ensured. In such a case, a method of making the interface between the metal soft magnetic films 3a and 3b unclear or making the composition ratio between the metal soft magnetic films 3a and 3b uniform by heat treatment after film formation. Can also be taken.

FIGS. 8 and 9 show the case where the metal soft magnetic film has a structure in which two kinds of films are laminated. However, even if the metal soft magnetic film has a structure in which three or more kinds of films are laminated. Good. Further, the number of stacked layers is not limited to the five layers shown in FIGS. 8 and 9. For example, even in a configuration in which the first core side and the second core side have different numbers of laminated layers, the effects of the present invention can be similarly obtained.

In the third head structure, both the metal soft magnetic film on the first magnetic core side and the metal soft magnetic film on the second magnetic core side have a laminated structure of a metal soft magnetic film and a non-magnetic insulating film. However, by making the composition ratios of the metal soft magnetic film and the nonmagnetic insulating film in both magnetic cores different from each other, it is also possible to realize a configuration in which the saturation magnetic flux densities of the metal soft magnetic films in both magnetic cores are made different. An example of the structure of such a head is shown in FIGS. 10 and 11 are diagrams showing a configuration example of the medium sliding surface of the ring-type magnetic head. Similar to FIGS. 1 to 7, the right side of the gap 6 is the first magnetic core half body and the left side is the second magnetic core half body. Shown as a magnetic core half.
FIG. 10 shows a configuration example of a laminated type head, and FIG. 11 shows MIG.
It shows an example of the configuration of the type head.

For example, in the example shown in FIG. 10, the nonmagnetic insulating film 13 has five layers on the side of the first magnetic core, whereas only two layers exist on the side of the second magnetic core. Similarly, in the example shown in FIG. 11, the nonmagnetic insulating film 13 has four layers on the first magnetic core side, whereas only two layers exist on the second magnetic core side. That is, by making the composition ratio of the metal soft magnetic film 3 on the second magnetic core side to the non-magnetic insulating film 13 larger than the composition ratio on the first magnetic core side,
The saturation magnetic flux density on the gap forming surface on the magnetic core side and in the vicinity thereof can be made higher than the saturation magnetic flux density on the first magnetic core side.

In the above structure, it is not possible to use a simple manufacturing method such as changing the gas partial pressure during sputtering in a constant cycle. However, for example, if a method of preparing two types of targets of a metal soft magnetic film and a nonmagnetic insulating film in a vacuum container and alternately sputtering them is used,
Compared with the structure in which the metal soft magnetic films 3a and 3b have completely different compositions, the metal soft magnetic films 3a and 3b are much simpler and excellent in reproducibility and productivity.

The presence of the nonmagnetic insulating film 15 is also effective for reducing the eddy current loss in the metal soft magnetic film 3. For example, in the above-described first head configuration, the average film thickness of the metal soft magnetic film 3b on the second magnetic core side is larger than twice the average film thickness of the metal soft magnetic film 3a on the first magnetic core side. However, if the average film thickness of the metal soft magnetic film 3b is too large, high frequency loss due to eddy current will occur. However, if the configuration of FIG. 11 is simultaneously realized in the first head configuration as shown in FIG. 1, the high frequency loss due to the eddy current can be reduced even if the average film thickness of the metal soft magnetic film 3b is sufficiently increased. Therefore, there is a lot of room to obtain an asymmetric recording magnetic field. Furthermore, in the configuration of FIG. 11, the effect of increasing the asymmetry of the recording magnetic field by making the saturation magnetic flux density on the gap forming surface on the second magnetic core side and in the vicinity thereof larger than the saturation magnetic flux density on the first magnetic core side. Is more preferable because it can also be obtained.

On the other hand, as the composition ratio of the non-magnetic insulating film 13 is increased, the saturation magnetic flux density on the gap forming surface and its vicinity decreases. In particular, it is necessary to pay attention so that the saturation magnetic flux density on the gap forming surface on the first magnetic core side and in the vicinity thereof does not become smaller than 0.8T. See also FIG.
In the laminated type head shown in FIG.
If the film thickness is large, signal recording may be lost at the position where the nonmagnetic insulating film 13 exists in the track width direction. In order to prevent this, the film thickness of the non-magnetic insulating film 13 needs to be sufficiently small in a range where a difference in saturation magnetic flux density can occur between the first magnetic core side and the second magnetic core side. . It is preferable that the thickness is several hundred nm or less. Alternatively, a technique of making the interface between the metal soft magnetic film 3 and the non-magnetic insulating film 13 unclear and further homogenizing the composition may be adopted by heat treatment after film formation. However, in this case, the effect of reducing the eddy current is likely to be lost, so it is important to obtain the optimum configuration in consideration of the frequency band used in the magnetic recording / reproducing apparatus in which the head is mounted.

(Structural Example of Magnetic Recording / Reproducing Device) In the magnetic recording / reproducing device of this embodiment, a ring-type magnetic head having at least one of the above-mentioned three structures is used, with the first magnetic core half body as the leading side. It is configured by being mounted on a rotary cylinder of a commercially available VTR, and its basic configuration is as shown in FIG.

Originally, in order to obtain the effect of the present invention, it is clear that it is necessary to set the first magnetic core half body to the leading side in the recording process, and the second magnetic core in the reproducing process. The half body may be the leading side. However, in the magnetic recording / reproducing apparatus of the present embodiment, the first magnetic core half body is used as the leading side in both the recording process and the reproducing process due to the original structure of the modified commercially available VTR.

Further, in order to carry out a recording / reproducing experiment in a high linear recording density region which exceeds the standard of a commercial VTR, some modifications are added to the recording amplifier, the reproducing amplifier and the like.

The direction of relative movement between the ring type magnetic head and the magnetic recording medium in this magnetic recording / reproducing apparatus can be set by the direction of the tape when the above-described vapor deposition tape is inserted into a commercially available cassette. The vapor deposition tape has a recording magnetic field near the leading edge of the ring magnetic head and an easy axis of magnetization of the vapor deposition tape in the normal plane of the vapor deposition tape magnetic layer including the relative movement direction of the ring magnetic head and the vapor deposition tape during recording. The vapor deposition tape was inserted into the cassette so as to have the structure of the present invention inclined to the same side with respect to the film normal of the magnetic layer.

The magnetic recording / reproducing apparatus described above was used to measure the recording / reproducing characteristics of the oblique anisotropic vapor deposition tape described in this example, and using the ring-type magnetic head having the above-mentioned constitution of the present invention. It was confirmed that excellent characteristics were obtained.

For example, when compared with an MIG type head using Sendust mounted on a commercially available VTR as a metal soft magnetic film, it has the first to third structures of the present invention having a gap length of 0.2 μm equivalent to this. When equipped with a magnetic head, the recording wavelength is 0.5 μm, 1.5 dB to 3 dB,
At a recording wavelength of 0.25 μm, a standardized reproduction output as high as 2.5 dB to 6 dB was obtained. On the other hand, regarding noise, a value equal to or less than that of the head having the conventional configuration was obtained. The constitution of the present invention is the characteristic improvement in the recording process due to the decrease of the magnetic transition width. Therefore, it is basically unlikely to increase the medium noise even if the reproduction output is increased. Rather, when the medium noise is caused by the nonuniformity of the domain wall shape in the magnetic transition region, it is considered that the noise is reduced by reducing the magnetic transition width. Therefore, the effect of increasing the reproduction output in the present invention is directly reflected in the S / N improvement in the magnetic recording / reproducing apparatus.

Although the vapor deposition tape having the magnetic layer containing Co and O as the main components is used as the magnetic recording medium in the above-mentioned embodiment, the effect of the present invention is limited by the composition of the magnetic layer. Instead, magnetic recording media composed of various compositions can be used as long as a highly oriented obliquely anisotropic media is realized.

In the present embodiment, an example of a VTR type magnetic recording / reproducing apparatus is shown, but the present invention is not limited to this, and various types of magnetic recording media such as magnetic cards and magnetic disks are used. It is useful for magnetic recording / reproducing devices.

Further, the constituent material of the mounted head is not limited to the material shown in this embodiment, and various kinds of materials are applied as long as the structure of the ring type magnetic head of the present invention is realized. be able to.

[0085]

According to the present invention, it is possible to provide a ring type magnetic head having a recording magnetic field distribution suitable for recording on an oblique anisotropic magnetic recording medium. As a result, the recording / reproducing characteristics can be remarkably improved particularly in the high linear recording density region, and a magnetic recording / reproducing apparatus capable of high-density recording as compared with the related art can be realized. That is, with the configuration of the present invention, it is possible to provide a magnetic recording / reproducing apparatus having a smaller size and a larger capacity than ever before.

Further, according to the present invention, it is possible to reduce the power consumption of the magnetic recording / reproducing apparatus by reducing the optimum recording current.

Furthermore, according to the present invention, in a ring type magnetic head manufactured by a very simple manufacturing process excellent in reproducibility and productivity, a recording magnetic field distribution suitable for recording on the above oblique anisotropic magnetic recording medium. Can be realized. That is, the ring-type magnetic head of the present invention does not sacrifice productivity to obtain the effect,
It can be provided at a low cost, similar to the conventional ring type magnetic head.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a magnetic head of the present invention. FIG. 1 (a) is a diagram showing a medium sliding surface of a magnetic head. FIG. 1 (b) is a diagram showing a core cross section in a gap length direction.

FIG. 2 is a diagram showing a configuration example of a magnetic head of the present invention. FIG. 2A is a diagram showing a medium sliding surface of the magnetic head. FIG. 2B is a diagram showing a core cross section in a gap length direction.

FIG. 3 is a diagram showing a configuration example of a magnetic head of the present invention. FIG. 3A is a diagram showing a medium sliding surface of the magnetic head. FIG. 3B is a diagram showing a core cross section in a gap length direction.

FIG. 4 is a diagram showing a configuration example of a magnetic head of the present invention. FIG. 4 (a) is a diagram showing a medium sliding surface of the magnetic head. FIG. 4 (b) is a diagram showing a core cross section in a relative movement direction with respect to the medium.

FIG. 5 is a diagram showing a configuration example of a magnetic head of the present invention. FIG. 5A is a diagram showing a medium sliding surface of the magnetic head. FIG. 5B is a diagram showing a core cross section in a relative movement direction with respect to the medium.

FIG. 6 is a diagram showing a configuration example of a magnetic head of the present invention. (A) is a diagram showing a medium sliding surface of the magnetic head. (B) is a diagram showing a core cross section in a relative movement direction with respect to the medium.

FIG. 7 is a diagram showing a configuration example of a magnetic head of the present invention. FIG. 7 (a) is a diagram showing a medium sliding surface of the magnetic head. FIG. 7 (b) is a diagram showing a core cross section in a relative movement direction with respect to the medium.

FIG. 8 is a diagram showing a configuration example of a medium sliding surface of the magnetic head of the present invention.

FIG. 9 is a diagram showing a configuration example of a medium sliding surface of the magnetic head of the present invention.

FIG. 10 is a diagram showing a configuration example of a medium sliding surface of the magnetic head of the present invention.

FIG. 11 is a diagram showing a configuration example of a medium sliding surface of the magnetic head of the present invention.

FIG. 12 is a diagram showing a configuration example of a magnetic recording / reproducing apparatus of the present invention.

FIG. 13 is a diagram showing an example of a configuration inside a vacuum vapor deposition apparatus for producing a vapor deposition tape having oblique anisotropy.

[Explanation of symbols]

 1 1st magnetic core half body 2 2nd magnetic core half body 3 3a 3b metal soft magnetic film 4 ferrite 5 glass material 6 gap 7 gap length direction 8 gap width direction 9 track width direction 10 azimuth angle 11 winding Line window 12 Non-magnetic substrate 13 Non-magnetic insulating film 14 Relative movement direction of head and medium 15 Leading edge 16 Trailing edge 17 Gap center line 18 Recording magnetic field 19 Direction of relative movement of head to medium 20 Magnetic layer 21 Substrate 22 Easy magnetization Axis 23 Film normal 24 Recording magnetization 25 Magnetic transition region 26 Inter-transition region 27 Cylindrical can 28 Substrate traveling direction 29 Supply roll 30 Winding roll 31A, 31B Shielding plate 32 Oxygen inlet 33 Evaporation source 34 Evaporated atom

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Noriyasu Echigo 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (11)

[Claims] 1. A metal forming a magnetic circuit having a gap by facing a first magnetic core half body and a second magnetic core half body formed by coating a metal soft magnetic film on the surface of a ferromagnetic ferrite. With an in-gap type ring type magnetic head,
The average thickness of the metal soft magnetic film deposited on the gap forming surface of the first magnetic core half is 1.5 μm or more, and the metal soft magnetic film deposited on the gap forming surface of the second magnetic core half. The magnetic head is characterized in that the average thickness thereof is larger than twice the average thickness of the metal soft magnetic film deposited on the gap forming surface of the first magnetic core half body. 2. The saturation magnetic flux density of the metal soft magnetic film deposited on the gap forming surface of the first magnetic core half is saturated with that of the metal soft magnetic film deposited on the gap forming surface of the second magnetic core half. The magnetic head according to claim 1, wherein the magnetic head has a magnetic flux density smaller than the magnetic flux density. 3. A ring type magnetic head comprising a first magnetic core half body and a second magnetic core half body made of a ferromagnetic material, which face each other to form a magnetic circuit having a gap, the first magnetic core half body. Of the magnetic material forming the gap forming surface and its vicinity is smaller than the saturation magnetic flux density of the magnetic material forming the gap forming surface of the second magnetic core half and its vicinity, and the first magnetic core A magnetic head, wherein the magnetic path cross-sectional area of the gap forming surface of the half body is smaller than the magnetic path cross-sectional area of the gap forming surface of the second magnetic core half body. 4. A ring-type magnetic head comprising a first magnetic core half body and a second magnetic core half body made of a ferromagnetic material, which face each other to form a magnetic circuit having a gap, the first magnetic core half body. Of the second magnetic core half and the magnetic material constituting the gap forming surface of the second magnetic core half and the magnetic material constituting the vicinity thereof are composed mainly of a plurality of the same elements, and the first magnetic The saturation magnetic flux density of the magnetic material forming the gap forming surface of the core half body and its vicinity is smaller than the saturation magnetic flux density of the magnetic material forming the gap forming surface of the second magnetic core half body and its vicinity. Magnetic head. 5. A ring-type magnetic head comprising a first magnetic core half body and a second magnetic core half body made of a ferromagnetic material which face each other to form a magnetic circuit having a gap, the first magnetic core half body. And the magnetic material forming the gap forming surface of the second magnetic core half and the vicinity thereof has a structure in which two or more kinds of soft magnetic films having different saturation magnetic flux densities are laminated, and the magnetic material of the first magnetic core half is The saturation magnetic flux density of the magnetic material forming the gap forming surface and its vicinity is smaller than the saturation magnetic flux density of the magnetic material forming the gap forming surface and its vicinity of the second magnetic core half body. The magnetic head described. 6. A ring type magnetic head comprising a first magnetic core half body and a second magnetic core half body made of a ferromagnetic material which are opposed to each other to form a magnetic circuit having a gap, the first magnetic core half body. And a magnetic material forming the gap forming surface of the second magnetic core half body and its vicinity has a structure in which a soft magnetic film and a non-magnetic insulating film are laminated, and the gap forming surface of the first magnetic core half body And the ratio of the total laminated thickness of the non-magnetic insulating film to the total laminated thickness of the soft magnetic film in the magnetic material forming the vicinity thereof is the soft magnetic property in the magnetic material forming the gap forming surface of the second magnetic core half body and its vicinity. 5. The magnetic head according to claim 4, wherein the ratio is smaller than the ratio of the total laminated thickness of the nonmagnetic insulating film to the total laminated thickness of the film. 7. A ring-type magnetic head comprising a first magnetic core half body and a second magnetic core half body made of a ferromagnetic material facing each other to form a magnetic circuit having a gap, the first magnetic core half body. Of the magnetic material forming the gap forming surface of the second magnetic core half and the magnetic material forming the vicinity thereof to B, C, N,
The saturation magnetic flux density of the magnetic material, which has a composition to which at least one element selected from O is added, and which forms the gap forming surface of the first magnetic core half body and its vicinity has the second
The magnetic head is characterized in that it is smaller than the saturation magnetic flux density of the magnetic material forming the gap forming surface of the magnetic core half body and its vicinity. 8. The saturation magnetic flux density of the magnetic material forming the gap surface of the first magnetic core half body and its vicinity is 0.8 T or more, and the gap surface of the second magnetic core half body and its vicinity are formed. 8. The saturation magnetic flux density of the magnetic material is 1.2 times or more the saturation magnetic flux density of the magnetic material forming the gap surface of the first magnetic core half body and its vicinity. 2. The magnetic head according to item 1. 9. The magnetic head according to claim 1, wherein the gap length is 0.22 μm or less. 10. A magnetic recording medium for recording a signal on a magnetic recording medium in which an easy axis of magnetization is inclined with respect to a film normal of a magnetic layer by using the magnetic head according to any one of claims 1 to 9. In a recording / reproducing apparatus, a recording magnetic field in the vicinity of a leading edge of a magnetic head and a magnetic field of the magnetic recording medium in a normal surface of a magnetic layer of the magnetic recording medium including a relative movement direction of the magnetic head and the magnetic recording medium in a recording process. The easy axis of magnetization is inclined to the same side with respect to the film normal of the magnetic layer of the magnetic recording medium, and in the relative movement direction of the magnetic head and the magnetic recording medium in the recording process, the first axis of the magnetic head A magnetic recording / reproducing apparatus having a configuration in which the magnetic core half body is on the leading side and the second magnetic core half body is on the trailing side. 11. An angle formed between the easy-axis direction of the magnetic recording medium and the film normal of the magnetic layer is 50 ° or more and 85 ° or less, and the coercive force in the easy-axis direction is 80 kA / m or more. The magnetic recording / reproducing apparatus according to claim 10, wherein the uniaxial anisotropy constant is 10 ⁵ J / m ³ or more.