JP2001060306A - Magnetic head and magnetic recording / reproducing device - Google Patents

Abstract

(57) [Summary] [Problem] A magnetic head immediately after being mounted on a rotating drum,
To obtain good contact with the magnetic tape without adjusting the shape of the sliding surface. SOLUTION: A magnetic core 6a and a magnetic core 6b abut each other to form a gap 2. The glass 4 is bonded to the upper butted portion. Each magnetic core is provided with a winding 5 to perform electromagnetic conversion. On the sliding surface of the magnetic head, two grooves 1a and 1b are formed at positions symmetrical with the gap 2 interposed therebetween in the drum rotation direction. The protective film 3 is formed on the surface of the sliding surface. According to the magnetic head of the present invention, it has been found that a groove formed on the sliding surface generates a negative pressure in the drum rotation direction, thereby improving the contact state between the tape and the magnetic head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a magnetic head used in a magnetic recording / reproducing apparatus having a rotating drum and a magnetic recording / reproducing apparatus having a magnetic head.

[0002]

2. Description of the Related Art In the prior art, a magnetic head mounted (mounted) on a rotating drum is used in a magnetic recording / reproducing apparatus on the premise that a certain amount of wear occurs when a magnetic tape runs. Normally, a magnetic head is polished on a sliding surface with a wrapping tape before being mounted on a rotating drum, and is polished in a longitudinal direction (a relative running direction of the head and the tape) and a width direction (a direction perpendicular to the longitudinal direction on the sliding surface). It is finished in a shape with each curvature. The magnetic head mounted on the rotating drum runs a lapping magnetic tape having a large abrasive force in order to obtain better contact with the magnetic tape. This running wears the magnetic head slightly,
Adjust the shape of the sliding surface to the running tape (fit)
I was Further, the magnetic head is worn by the tape running for a long time, and the protrusion amount is reduced (for example, when the tape runs for 1000 hours, the wear amount of the magnetic head gap is 10 μm).
m), the initial protrusion amount is determined in consideration of the wear amount so that sufficient head touch can be performed even if the magnetic head is worn. The size of the magnetic head sliding surface is VHS
For a system VTR, for example, the core width is 100 μm and the length in the longitudinal direction is 2 mm.

As another conventional example, a magnetic head using a reproducing principle different from that of an inductive magnetic head has been developed and put into practical use. This magnetic head is a magnetic head (hereinafter referred to as an MR head) using a magneto-resistive effect element for reproduction. M
In the R head, the reproduction output does not depend on the relative speed between the MR head and the magnetic recording medium, but is proportional to the applied sense current. Taking advantage of this feature, MR heads cannot provide sufficient output with magnetic recording devices such as digital audio, where the relative speed between the head and the magnetic recording medium is extremely slow, or with inductive magnetic heads due to the extremely high recording density. It has recently been used in magnetic recording devices such as hard disk devices.

[0004] For the following reasons, the MR head is designed to have a very small size in the direction perpendicular to the sliding surface with the magnetic tape (hereinafter referred to as head height). That is, it is known that the intensity of the magnetic field from the magnetic recording medium decreases exponentially in the head height direction. Therefore, when the MR head is arranged on the magnetic recording medium, the inflow magnetic flux is greatly attenuated at about several μm in the head height direction in the MR head. In the area where the magnetic flux flows,
The direction of magnetization of the MR head is rotated by the flowing magnetic flux, and M
The resistance value of the R head changes.

When a current is applied to the MR head, a voltage corresponding to a change in the resistance value is generated at both ends of the MR head, and the voltage is extracted as a reproduction signal voltage of information recorded on the medium. In order to extend the life of these magnetic heads, it has been proposed to form a protective film on the sliding surface of the magnetic head (for example, JP-A-6-119613). It is considered that a long life magnetic head can be realized if the wear is suppressed by the protective film.

[0006]

However, when a magnetic tape having a large abrasive force is run and the magnetic head is worn and the head shape is adjusted to a desired shape (fitted), the magnetic head becomes, for example, one to one. Wear by 2 μm. For this reason, in anticipation of the wear amount, the initial head protrusion amount,
The depth of the magnetic head must be determined. Also,
The life of a magnetic head having a small initial depth is shortened. There was a need to solve these problems.

As described above, efforts have recently been made to increase the recording density of a magnetic tape device using an MR head. However, when an MR head is used in a rotary drum type magnetic tape device such as a VTR,
There is a need to improve the low wear resistance of the R head. In the rotary drum type magnetic tape device, the sliding area between the magnetic head and the magnetic tape is small. Therefore, the pressure applied to the magnetic head per unit area is high. In addition, since the magnetic head and the magnetic tape slide at a high relative speed exceeding 10 m / sec, conditions for wear are severe.

Since the MR head has a small head height,
It wears out in a short time and the output stops. Further, since the cross-sectional area of the MR head itself decreases with the progress of wear and the resistance value of the MR head increases, the MR head is damaged by Joule heat generated by a sense current applied for detecting a signal. Further, since the relationship between the strength of the magnetic field of the MR head and the change in resistance is non-linear, signal distortion caused by this non-linearity is also complicatedly affected by wear. Thus, M
Since the R head is greatly affected by wear, it is desirable that the initial shape and the head touch be good.
Further, if a protective film is formed on the sliding surface of the magnetic head, the shape of the sliding surface cannot be adjusted after mounting on the rotating drum, so that good contact with the magnetic tape is hardly obtained. On the other hand, when the core width of the sliding surface is increased to reduce the wear of the protective film or the head protrusion amount is reduced,
There was a problem that the head touch deteriorated. SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetic head with low abrasion and good magnetic contact with a magnetic tape, and a magnetic recording / reproducing apparatus using the magnetic head.

[0009]

According to a first aspect of the present invention, there is provided a magnetic head mounted on a rotating drum and performing magnetic recording or reproduction by sliding in contact with a magnetic tape, wherein the magnetic head contacts the magnetic tape. Two grooves are formed in the sliding surface substantially in the direction of rotation of the drum at a predetermined interval, and a gap is formed in the sliding surface sandwiched between the two grooves.

[0010] The invention of claim 4 is the above invention, further comprising:
A rotating drum device having a rotating drum having a magnetic head and a fixed drum adjacent to the rotating drum; guiding a magnetic tape to the rotating drum device; and bringing the magnetic tape into contact with the outer peripheral surfaces of the fixed drum and the rotating drum And a capstan and a pinch roller for transferring the magnetic tape at a predetermined speed. According to a fifth aspect of the present invention, there is provided a magnetic head which is mounted on a rotating drum and performs magnetic recording or reproduction by sliding in contact with a magnetic tape. Two axial grooves are formed at predetermined intervals with a gap therebetween, and the position of the grooves is within a range of a sliding portion where the magnetic head and the tape come into contact.

[0011] The invention of claim 7 is the above invention, further comprising:
A rotating drum device having a rotating drum having a magnetic head and a fixed drum adjacent to the rotating drum; guiding a magnetic tape to the rotating drum device; and bringing the magnetic tape into contact with the outer peripheral surfaces of the fixed drum and the rotating drum And a capstan and a pinch roller for transferring the magnetic tape at a predetermined speed.

According to an eighth aspect of the present invention, there is provided a magnetic head having a magnetoresistive element, wherein a concave portion is formed on a sliding surface with a magnetic recording medium so as to surround the magnetoresistive element. I do.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below by describing preferred embodiments of the present invention with reference to the accompanying drawings.

Embodiment 1 A magnetic head according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG.
1A is an external view of a magnetic head according to the first embodiment, FIG. 1A is a front view, FIG. 2B is a side view, and FIG. 1C is an enlarged view of a sliding surface. As shown in FIG. 1B, in the magnetic head, a left magnetic core 6a made of, for example, ferrite and a right magnetic core 6b are abutted, and a gap 2 is formed therebetween. The bonding glass member 4 is bonded to the upper butted portion. The windings 5 are applied in series to the respective magnetic cores 6a and 6b to perform electromagnetic conversion. Let Dn be the distance from the top of the sliding surface to the notched portion 600 of the winding.

On the sliding surface 6s of the magnetic head, two grooves 1a and 1b are provided in the drum rotation direction (hereinafter referred to as longitudinal direction) with the gap 2 interposed therebetween in the longitudinal direction and the width direction perpendicular to the gap center point. Each is formed at a symmetrical position. As shown in FIG. 1C in an enlarged manner, the track width of the gap is Tw, the width of each groove is Wg, the width of the sliding surface including the gap portion sandwiched between the two grooves is W1, and the magnetic field from the groove is W1. The width of the sliding surface up to the end of the core is W2, and the depth of the groove measured from the sliding surface at the top of the head is Dg. For example, the width Wg of each groove
Is 20 μm each, Dg is 100 μm, W1 is 60 μm, W
2 is 100 μm. The core width Wt of the entire sliding surface is 30
0 μm.

Here, in order to examine the optimum range of W1, the core width of the entire sliding surface is 300 μm, Wg is 20 μm,
Tw is fixed at 10 μm, and the width of W1 is changed from 10 μm to 20 μm.
The change in output when it was changed to 0 μm was determined. Using the minimum and maximum values of the output obtained from the output envelope,
The value obtained by dividing the minimum value by the maximum value was obtained and defined as envelope flatness. The relationship between the width W1 of the sliding surface including the gap and the flatness of the envelope is shown in FIG. Assuming that the envelope flatness is allowed up to 0.9, the value of the width W1 of the sliding surface is preferably 100 μm or less. In an actual head, the track width Tw differs depending on the head,
The width W1 of the sliding surface is preferably in the range of Tw or more and 100 μm or less so as not to adversely affect recording and reproduction.

In this embodiment, the length of the sliding surface is, for example, 2 mm. A preferable example of the radius of curvature in the side view of the sliding surface of the magnetic head is, for example, 2 mm in the core width direction and 6 mm in the drum rotation direction. Since the groove is processed by a dicing saw, for example, it is generally formed in parallel with the bottom surface of the magnetic core. Therefore, in detail, the depth from the bottom of the groove to the sliding surface is not constant, but is deep at the top and shallow at both ends in the drum rotation direction. FIG. 3 shows the relationship between the groove depth and the groove length at the top of the head when the radius of curvature R of the sliding surface in the drum rotation direction is constant. Each curve is obtained when the value of the radius R is used as a parameter. The length of the sliding surface is usually 0.5 to 3 mm, and the radius of curvature of the sliding surface in the drum rotation direction is usually 1 to 10 mm.

Looking at the groove depth direction of the magnetic head, there is a portion where the length of the magnetic core is shortened due to notching of the winding portion or the like. If the value of Dg is too large, the strength of the magnetic head is reduced. It may fall and affect the electromagnetic conversion characteristics. In a normal magnetic head, the distance Dn from the top of the sliding surface to the upper end of the notched part (window) of the winding part is 100 to 2
00 μm. The value of Dg is determined in consideration of the radius of curvature of the magnetic head and the length of the groove.

In order to find the optimum range of the width Wg of the groove,
The core width Wt of the entire sliding surface is 300 μm, Tw is 10 μm,
A change in output when the width of W1 was fixed at 60 μm and the value of the groove width Wg was changed from 2 μm to 100 μm was determined. FIG. 4 shows a relationship diagram between the groove width Wg and the output envelope flatness (relative value). Assuming that the range of the envelope flatness exceeding 0.9 is acceptable, the value of Wg is 10 μm or more and 5 μm or more.
A range of 0 μm or less is an allowable range.

In the magnetic head of the present invention, when the magnetic head is mounted on the rotating drum, the grooves 1a, 1
As a result, a negative pressure is generated at the center of the sliding surface. This negative pressure improves the contact state between the tape and the magnetic head. By providing the grooves 1a and 1b, it is not necessary to adapt the tape at the beginning (to perform a fitting process).

Embodiment 2 A magnetic head according to Embodiment 2 of the present invention will be described with reference to the drawings. FIG.
7A and 7B are external views of a magnetic head according to the second embodiment, in which FIG. 7A is a front view, FIG. 8B is a side view, and FIG. 9C is an enlarged view of a sliding surface 18s. As shown in FIG. 5B, in the magnetic head, a left magnetic core 18a made of, for example, ferrite and a right magnetic core 18b abut against each other, and a gap 8 is provided therebetween.
Is formed. A glass member 10 for bonding is bonded to the upper butted portion. Each magnetic core 18
The windings 17 are applied in series to a and 18b to perform electromagnetic conversion.

On the sliding surface of the magnetic head, two grooves 7a and 7b are formed in the drum rotation direction at positions symmetrical in the longitudinal direction and the width direction perpendicular to the gap center point with the gap 8 interposed therebetween. You. On the surface of the head sliding surface, a protective film 9 made of diamond-like carbon is formed with a thickness of, for example, 50 nm by ECR (electron cyclotron resonance) plasma CVD.

In this embodiment, an example of the method of producing diamond-like carbon using the ECR plasma CVD method has been described, but RF plasma CVD may also be used. Further, other methods described below can also be used. That is, a reactive sputtering method, a sputtering method, an ion plating method, and a cathodic arc method can be used.

As shown in FIG. 5C, the track width of the gap is Tw, the width of each groove is Wg, the width of the sliding surface including the gap portion sandwiched between the two grooves is W1, and the width of the groove is W1. The width of the sliding surface from the groove to the end is W2, the length of the groove is L, and the depth of the groove measured from the sliding surface at the top of the head is Dg. Where W
1 must be larger than Tw in order not to adversely affect recording and reproduction. The width Wg of each groove is preferably from 10 to 50 μm. In the second embodiment, for example, Wg is 20 μm and L is 6
Let 30 μm and Dg be 10 μm. W1 is, for example, 70 μ
m and W2 are 80 μm. Therefore, the core width of the entire sliding surface is 270 μm.

In this embodiment, the length of the sliding surface is, for example, 1.5 mm. The radius of curvature in the side view of the sliding surface of the magnetic head is, for example, 1.8 mm in the core width direction and 5 mm in the drum rotation direction. Looking at the depth direction of the groove of the magnetic head, there is a portion where the length of the magnetic core is shortened due to notch processing of the winding portion or the like. Therefore, if the value of Dg is too large, the strength of the magnetic head may decrease, and the electromagnetic conversion characteristics may be affected. In a normal magnetic head,
The distance from the top of the sliding surface to the notch in the winding is 1
It is 00 to 200 μm. The value of Dg is determined in consideration of the radius of curvature of the magnetic head and the length of the groove. The value of Wg is preferably 10 μm to 50 μm as described in the first embodiment.

When the magnetic head of the second embodiment was mounted on a VTR and the tape was run, the length of the sliding surface 18s where the magnetic head and the tape contacted was 800 μm, and the groove 7
a and 7b are shorter than the length of the sliding surface and are located at the sliding portion. Grooves 7a, 7b of sliding surface 18s in this state
As a result, the contact between the head and the tape was improved because the tape was pulled under negative pressure. In the magnetic head of the present embodiment, a negative pressure is generated only in the contacting part. Therefore, the deformation is gradual on the sliding surface outside the groove without the influence of the groove, so that, for example, even when a thin tape having a total tape thickness of 10 μm or less runs, damage can be avoided.

The magnetic head of Example 2 and Comparative Examples 1 to 3 having the core width of the sliding surface shown in Table 1 below and having no groove were formed.
The magnetic head No. 3 was mounted on the same VHS VTR, and an experiment was conducted on the output and wear characteristics of the magnetic head. A known diamond-like carbon having a thickness of 30 nm was formed as a protective film on all the magnetic head sliding surfaces of the examples and comparative examples. The length and radius of curvature of the sliding surface were the same for all heads. The abrasion characteristics were judged as ○ (good) when the amount of abrasion after running the tape for 1000 hours was 3 μm or less, and as × (poor) when the amount exceeded 3 μm. The output was evaluated as ○ (good) when the envelope flatness was 0.9 or more, and × (poor) when the envelope flatness was less than 0.9.

Table 1 shows the evaluation results of the core width, the protrusion amount, the output and the wear characteristics of the sliding surface. In this example, both the output and the wear characteristics were good, whereas in Comparative Example 1, the output was good, but the amount of wear was large, and in Comparative Example 2, both the output and the wear characteristics were poor. Comparative Example 3 has good wear characteristics,
Output was bad. It is considered that the reason why the output was poor in Comparative Examples 2 and 3 was that the head touch (the contact state between the tape and the magnetic head) in the gap portion was poor due to the large core width, that is, spacing was achieved. The magnetic head of this example had a large core width due to the effect of the grooves, and had good head touch and good wear characteristics (less wear) even when the protrusion amount was small.

[0029]

[Table 1]

According to the magnetic head of the present invention, when the magnetic head is mounted on the rotary drum, the groove 7 formed on the sliding surface
Since a and 7b generate a negative pressure, the contact state between the tape and the magnetic head is improved. By providing the grooves 7a and 7b, it is not necessary to adapt the tape (to perform a fitting process) at the beginning of use of the head. On the other hand, in the magnetic head without the protective film, the length of the groove changes due to the abrasion caused by the running of the tape, and the effect of attracting the tape is weakened at an early stage. According to this, since the protective film suppresses abrasion, even if the tape runs for a considerable time (1000 hours in the example in the above table), a change in the length of the groove is small, and stable head touch can be realized.

Third Embodiment A magnetic head according to a third embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a perspective view showing the basic structure of the magnetic head of this embodiment.
FIG. 7 is an external view of a magnetic head according to the third embodiment.
(A) is a front view, (b) is a side view, and (c) is an enlarged view of a sliding surface. In this embodiment, a case where the magnetic head is a thin film magnetic head will be described. In FIG. 6, a thin-film magnetic head is made of a magnetic material having an anisotropic magnetoresistive effect, such as NiFe or FeCo, or a magnetic material having a giant magnetoresistive effect on a NiZn ferrite substrate 104 having excellent wear resistance. Accordingly, the MR element 101 having a predetermined pattern formed as described below is provided.

As a preferred example of the MR element of the shield, Japanese Patent Application No. Hei 7-93 of the same assignee is used.
723 and Japanese Patent Application Laid-Open No. 7-153035, and the technology of which the entirety of those disclosures is incorporated in the present application can be used by referring to those numbers here.
The MR element 101 has the structure of a shield type MR head, and two grooves 106a and 106b extending in the drum rotation direction in the longitudinal direction are provided on the magnetic head sliding surface 109 with the MR element 101 interposed therebetween. Are formed at substantially symmetric positions. On the surface of the head sliding surface, a protective film 107 made of diamond-like carbon is formed with a thickness of, for example, 50 nm by ECR plasma CVD.

In the present embodiment, an example using ECR plasma CVD as a method for producing diamond-like carbon has been described, but RF plasma CVD can also be used. Further, other methods described below can also be used. That is, a reactive sputtering method, a sputtering method, an ion plating method, and a cathodic arc method can be used.

As shown in FIG. 7C, the width of the groove is Wg,
The width of the sliding surface including the gap portion between the two grooves is represented by W
1. The width of the sliding surface from the groove to the end is W2, the length of the groove is L,
The depth of the groove at the head apex is Dg (not shown). Here, the width W1 of the sliding surface must be larger than the length of the MR element 101 on the sliding surface so as not to adversely affect the electromagnetic conversion. Wg is preferably from 10 to 50 μm. Here, for example, the width Wg of the groove is 20 μm and L is 560.
μm and the width Dg of the groove is 10 μm.

In a preferred embodiment, W1 is, for example, 70 μm.
m and W2 are 80 μm, and the core width of the entire sliding surface is 2 μm.
70 μm. At this time, the length of the sliding surface is set to, for example, 1.
5 mm, the radius of curvature of the magnetic head is, for example, 2 m in the core width direction.
m, 4 mm in the drum rotation direction.

The head of the MR element 101 is, for example, disclosed in Japanese Patent Application Laid-Open Nos. 7-153035 and 7-93 filed by the same applicant.
723 can be used. The contents of these techniques are individually incorporated herein by reference. As the form of the MR head, in addition to the above-mentioned shield type MR head, various forms such as an unshielded type MR head, a dual stripe type MR head, a vertical type MR head, and a flux guide type MR head can be used. it can. The MR head forms a thin film having a magnetoresistive effect by a sputtering method such as a high frequency sputtering method and a vapor deposition method, and is formed by photolithography.
And a predetermined pattern is formed by ion milling and chemical etching.

This MR head has an MR head on at least one side.
The element 101 is sandwiched between a pair of substrates 104 and 105 via a support protection layer 102 for supporting and protecting the element 101.
As a material that can be used for the protective layer 102,
Low melting point glass such as borosilicate glass and lead glass, or oxide such as Al2O3 and SiO2, or Si3N
4. A nitride such as TaN is preferable.

As the material of the substrates 104 and 105, in addition to the above-mentioned NiZn ferrite, a magnetic ferrite such as MnZn ferrite, a non-magnetic ferrite such as Zn ferrite, or Al2O3-TiC, which has excellent wear resistance. Alpha Hematite, NiO-T
Ceramics such as iO2-MgO, TiO2-CaO and NiO-MnO can be used.

Also, as shown in FIG. 6, the height of the substrate 105 is lower than the height of the other substrate 104, and the terminal 103 under the MR element 101 is exposed.
The terminal 103 is connected to an external circuit (not shown).

When the magnetic head of the third embodiment was mounted on a VTR and the tape was run, the sliding length of the tape in contact with the magnetic head was 700 μm, and the groove was shorter than this sliding length. It is located in. In the operation in this state, the groove portion of the sliding surface becomes negative pressure and draws the tape, so that the contact state between the head and the tape is improved. Further, the core width of the sliding surface is wider than that of the conventional magnetic head. Therefore, the contact surface pressure is reduced and wear is reduced. In the magnetic head of this embodiment, since the negative pressure is generated only in the contacting portion, the tape is gently deformed without the influence of the groove on the sliding surface outside the groove. Therefore, for example, even when a thin tape having a total thickness of 10 μm or less runs, damage can be avoided.

For comparison with the third embodiment, a magnetic head having the same shape as that of the present embodiment and having no protective film was used for the same VTR.
And the tape was run. In the comparative example, the running time of the tape increased and exceeded 500 hours, and at the same time, the magnetic head was worn and the height of the MR element was changed, and the output waveform was distorted. It was found that in the magnetic head of this embodiment, there was almost no wear even after a running time of 1000 hours or more, and the output waveform was not distorted. According to the magnetic head of the third embodiment, the negative pressure is generated by the groove formed on the sliding surface, and the tape is drawn by the negative pressure. In this way, a stable head touch is realized, and the protective film suppresses abrasion, so that stable electromagnetic conversion can be performed for a long time.

Embodiment 4 A magnetic head according to Embodiment 4 of the present invention will be described with reference to the drawings. FIG.
7A and 7B are external views of the magnetic head according to the fourth embodiment, in which FIG. 7A is a front view and FIG. As shown in FIG. 8B, in the magnetic head, a left magnetic core 16a made of, for example, ferrite and a right magnetic core 16b are abutted.
A gap 12 is formed. A glass member 14 for bonding is bonded to the upper butted portion. The windings 15 are applied in series to the left and right magnetic cores 16a, 16b, respectively, to perform electromagnetic conversion.

In the magnetic head sliding surface, two grooves 11 are formed across the core width in a direction substantially perpendicular to the rotation of the rotating drum (for example, in a direction substantially parallel to the gap 12).
a, 11b are formed at substantially symmetric positions with the gap 2 interposed therebetween. For example, a groove is formed at a position 250 μm away from the gap 2. These grooves 11a and 11b have a width of 10 to 100 μm and a depth of 10 to 100 μm. In this embodiment, for example, the width of the groove is 30 μm and the depth is 70 μm. Here, the length of the sliding surface was 1.5 mm, and the core width was 200 μm. The radius of curvature of the magnetic head is
For example, 2 mm in the core width direction and 5 mm in the drum rotation direction
It is.

The groove generates a negative pressure for drawing the magnetic tape. Since the magnitude of the negative pressure is determined depending on the width, depth and position of the groove, it must be determined according to the system in which the magnetic head is mounted. Groove width is 100
If it exceeds μm, the tape will be greatly deformed in the groove and may be damaged by contact.
１００100 μm is preferred. The depth of the groove will be described.

Since there is a portion where the length of the magnetic core is shortened due to notch processing of the winding portion or the like, if the depth of the groove is too large, the strength of the magnetic head decreases and the electromagnetic conversion characteristics may be affected. There is. In a normal magnetic head, the distance from the top of the sliding surface to the notch in the winding is 100 to 100 mm.
200 μm is preferred. Regarding the position of the groove in the drum rotation direction, it is desirable that the groove be located within the range of the sliding portion where the tape and the magnetic head come into contact (in the drum rotation direction). This is because, when a groove is formed outside the sliding portion, the effect of drawing the tape by the action of the groove is reduced because the distance from the tape is large. In the example of this embodiment, the sliding length between the tape and the magnetic head when mounted on a VTR was 700 μm, and the position of the groove in the drum rotation direction was located at the sliding portion.

According to the magnetic head of the present invention, the grooves 11a and 11b formed on the sliding surface generate a negative pressure in the drum rotation direction, and the state of contact with the tape is improved. Furthermore, since pressure is generated in the direction of the drum rotation axis from the magnetic head groove,
Tape deformation near the magnetic head in the direction of the drum rotation axis becomes gentle. Thereby, in a system where the tape deformation near the magnetic head becomes large, the contact between the head and the tape can be improved. Further, in the device provided with the groove, it is not necessary to adapt the tape (to perform a fitting process) at the beginning of use.

In order to confirm the effect of the groove of the magnetic head, the magnetic head of this embodiment and the magnetic head of Comparative Example 4 having the same shape except that no groove was provided on the sliding surface were mounted on the same rotating drum. . The magnetic tape was run in an apparatus using the rotating drum, and the tape deformation shape was measured with an optical micrometer. FIG. 9 is a cross-sectional view of the deformed tape shape near the head in the direction of the rotation axis of the rotary drum. In FIG. 9, the horizontal axis indicates the position (+ direction indicates the direction of the rotating drum, and − direction indicates the direction of the fixed drum), and the vertical axis indicates the displacement of the tape. The solid line shows the displacement of the magnetic head of the present embodiment, and the broken line shows the displacement of the magnetic head without a groove of Comparative Example 4. The position of the magnetic head is indicated by a vertical dashed line. It can be seen from the figure that the magnetic head of the present embodiment has a gentler manner of contact with the magnetic head (the tape is not deformed so strongly at the head position) as compared with the magnetic head having no groove.

Embodiment 5 A magnetic head according to Embodiment 5 of the present invention will be described with reference to FIG. FIG. 10 is an external view of a magnetic head according to the fifth embodiment.
(A) shows a front view and (b) shows a side view. FIG. 10 (b)
In the magnetic head, a left magnetic core 37a made of, for example, ferrite and a right magnetic core 37b are abutted to form a gap 20. A glass member 29 for bonding is bonded to the upper butted portion. Each magnetic core is provided with a winding 30 in series to perform electromagnetic conversion.

On the magnetic head sliding surface, two grooves 19 are formed across the core width in a direction substantially perpendicular to the rotation of the rotary drum (for example, a direction substantially parallel to the gap 12).
a, 19b are formed at substantially symmetric positions with the gap 2 interposed therebetween. For example, each groove is formed at a position 150 μm away from the gap 20. These grooves 19a, 19b
Has a width of 30 μm and a depth of 70 μm, for example. Here, the length of the sliding surface was 1.5 mm, and the core width was 200 μm. The radius of curvature of the magnetic head is, for example, 2 in the core width direction.
mm in the drum rotation direction. On the surface of the sliding surface, a protective film 13 made of, for example, cubic boron nitride is formed with a thickness of, for example, 30 nm by an ion plating method.

The grooves generate a negative pressure for drawing the magnetic tape. Since the magnitude of the negative pressure is determined depending on the width, depth and position of the groove, it must be determined according to the system in which the magnetic head is mounted. Groove width is 100
If it exceeds μm, the tape will be greatly deformed in the groove and may be damaged by contact.
１００100 μm is preferred. The depth of the groove will be described.

Since there is a portion where the length of the magnetic core is shortened due to the notch processing of the winding portion or the like, if the depth of the groove is too large, the strength of the magnetic head is reduced and the electromagnetic conversion characteristics may be affected. There is. In a normal magnetic head, the distance from the top of the sliding surface to the notch in the winding is 100 to 100 mm.
200 μm is preferred. Regarding the position of the groove, it is desirable that the groove be located in the range of the sliding portion where the tape and the magnetic head come into contact. This is because, when a groove is formed outside the sliding portion, the effect of drawing the tape by the action of the groove is reduced because the distance from the tape is large. In the example of this embodiment, the sliding length between the tape and the magnetic head when mounted on a VTR was 650 μm, and the groove was located at the sliding portion.

According to the magnetic head of the present invention, when mounted on a VTR, the wear can be suppressed by the protective film 13. Further, the grooves 19a and 19b formed on the sliding surface generate a negative pressure in the drum rotating direction, and the contact state with the tape is improved. Further, since pressure is generated from the groove of the magnetic head in the direction of the rotation axis of the drum, tape deformation near the magnetic head in the direction of the rotation axis of the drum becomes gentle. As a result, the flying height of the tape is reduced, so that the contact between the head and the tape can be improved in a system where the deformation of the tape near the magnetic head increases. Further, in the device provided with the groove, it is not necessary to adapt the tape (to perform a fitting process) at the beginning of use.

Embodiment 6 A magnetic head according to Embodiment 6 of the present invention will be described with reference to the drawings. FIG.
1 is an external view of a multi-magnetic head according to Embodiment 6.
(A) is a front view, (b) is a side view. The first magnetic head 26 and the second magnetic head 27 are adhered to a brass head base 28 preferably by an ultraviolet curing resin. The first magnetic head 26 has a gap 22 formed by abutting a left magnetic core 26a made of, for example, ferrite and a right magnetic core 26b, similarly to the magnetic head of the fourth embodiment described above. The bonding glass member 24 is bonded to the upper butted portion. Each of the magnetic cores is provided with a winding 25 to perform electromagnetic conversion.

The sliding surface of the magnetic head has two grooves 2 in a direction intersecting at right angles to the running direction of the head, preferably in a direction parallel to the gap 22 (axial direction of the rotating drum).
1a and 21b are located symmetrically in the running direction of the head with the gap 22 interposed therebetween.
It is formed at the position of μm. In a preferred embodiment, for example, the grooves are 30 μm wide, 210 μm long and 70 μm deep.

On the other hand, the second magnetic head 27 is the same as the magnetic head of the first embodiment, and a left magnetic core 36a made of, for example, ferrite and a right magnetic core 36b are abutted to form a gap 32. The bonding glass member 34 is bonded to the upper butted portion. Each magnetic core is provided with a winding 35 to perform electromagnetic conversion.
On the sliding surface of the magnetic head, two grooves 31a and 31b parallel to the drum rotation direction are formed at symmetrical positions with a gap 32 interposed therebetween. For example, the groove is 30 μm wide and 1000 μm long
m, depth 70 μm. When the multi-magnetic head is mounted on a rotating drum, the magnetic head A26 is mounted so as to come in contact with the tape first.

According to the magnetic head of the present invention, a negative pressure is generated by the groove on the sliding surface of the magnetic head, and the magnetic head 26 comes into contact with the tape first, the magnetic head 27 comes into contact with the tape later, The contact state of the tape is stably improved.
Therefore, there is no need to initially adjust the magnetic head. In addition, the protrusion amount of the magnetic head can be set lower than before,
Also, since the contact property of the tape is improved, the core width W of the sliding surface is increased.
Since t can be increased, the surface pressure received by the magnetic head can be reduced to reduce the amount of wear.

In this embodiment, two types of the first magnetic head 26 and the second magnetic head 27 are used. However, one type of the same type of magnetic head is attached to the head base 28 adjacently. It may be. Further, a multi-magnetic head in which three or more magnetic heads are attached to the head base 28 can be configured.

In this embodiment, examples using the magnetic heads of the first and fourth embodiments have been described. However, changing the combination of a plurality of magnetic heads may also have good technical effects. Next, such a case will be described.

When the relative speed between the magnetic head and the magnetic tape is 10
In a magnetic recording / reproducing device exceeding m / s, the deformation shape when the multi-magnetic head comes into contact with the magnetic tape was measured.
It has been found that the deformation is more gradual than the deformation on the magnetic head that comes into contact with the tape in advance, so that the magnetic head that comes into contact with the tape later may easily cause spacing.

In such a case, for example, an ordinary magnetic head having no groove is arranged for the magnetic head that comes into contact with the tape first, and the magnetic head of this embodiment is used for the magnetic head that comes into contact with the tape later. It is preferable to use a head. According to this configuration, the deformation of the tape on the magnetic head that comes in contact with the tape later by the effect of the groove on the sliding surface can be made closer to that of the magnetic head that comes in contact with the tape earlier, and A multi-magnetic head with less pacing can be provided.

Further, in this embodiment, the example using the magnetic head having no protective film on the sliding surface of the first and fourth embodiments has been described. They may be used in combination. In this case, the wear resistance is further improved by the protective film.

Embodiment 7 FIG. 12 shows a VHS system VT.
It is a top view of the running system of R. The VTR includes a rotary drum device 41, a supply reel 40, and a take-up reel 4 on which the magnetic head according to the second embodiment of the present invention is mounted as the magnetic head 46.
2, rotating posts 43, 44, 48, 49, 52, 54,
It includes inclined posts 45 and 47, a capstan 50, a pinch roller 51, and a tension arm 53.
55 is a magnetic tape.

The magnetic tape 55 wound on the supply reel 40
Travels by a retraction operation of the pinch roller 51 and the capstan 50, is pressed against the head 46 mounted on the rotary drum device 41 under the guidance of the inclined posts 45 and 47, and passes between the pinch roller 51 and the capstan 50. It is wound on a take-up reel 42. The rotating drum device is of an upper rotating drum type, and two magnetic heads 46 are mounted so as to protrude from the side surface of the rotating drum by 25 μm.

In the magnetic recording / reproducing apparatus according to the structure of this embodiment, since the wear can be suppressed by the protective film of the magnetic head 46, a high head output can be obtained by reducing the gap depth. Also, since the amount of protrusion of the magnetic head at the beginning of use of the apparatus can be made smaller than before, damage to the tape can be reduced, and the tape is drawn by the effect of the groove on the sliding surface of the magnetic head, and the contact state between the magnetic head and the magnetic tape. Can be kept good.

In this embodiment, the configuration in which the magnetic head 46 according to the second embodiment is attached to the rotary drum device 41 has been described.
Needless to say, it can be attached to the first.

Embodiment 8 FIG. 13 is a plan view of a traveling system of a DDS (Digital Data Storage) device. The magnetic reproducing apparatus of the DDS system includes a rotating drum device 61 on which the magnetic head according to the fifth embodiment of the present invention is mounted as a magnetic head 66, a supply reel 60, a take-up reel 62, rotating posts 63, 64, 68, 69, 72; Inclined post 6
5, 67, a capstan 70, and a pinch roller 71. 73 is a magnetic tape.

The magnetic tape 73 wound on the supply reel 60
Travels by a retraction operation of the pinch roller 71 and the capstan 70, is pressed against the magnetic head 66 mounted on the rotary drum device 61 by the guides of the inclined posts 65 and 67, and passes between the pinch roller 71 and the capstan 70. To be taken up by the take-up reel 62. The rotating drum device is of a medium rotating drum type, and has a magnetic head 66.
Are mounted so as to protrude 10 μm from the side surface of the rotating drum.

In the magnetic recording / reproducing apparatus according to the structure of this embodiment, the wear can be suppressed by the protective film of the magnetic head 66, so that a high head output can be obtained by reducing the gap depth. Also, since the initial magnetic head protrusion amount can be made smaller than before, tape damage can be reduced, and the tape is drawn by the effect of the groove on the magnetic head sliding surface, so that the contact state between the magnetic head and the magnetic tape can be improved. Can be kept.

Since the floating amount of the magnetic tape in the drum device of the middle rotating drum type is smaller than that of the upper rotating drum device in the seventh embodiment, the amount of deformation of the tape near the magnetic head increases, and Problems such as a strong hit and a reduction in output due to spacing occurring near the gap may occur. According to the magnetic recording / reproducing apparatus having the configuration of the present embodiment, the effect of the groove in the rotating shaft direction on the sliding surface of the magnetic head reduces the tape deformation in the width direction of the magnetic head and improves the contact state between the magnetic head and the magnetic tape. There is.

In this embodiment, the magnetic head 66 of the fifth embodiment is used as a magnetic head. However, it goes without saying that the magnetic head of the first to fourth embodiments can be used.

Embodiment 9 FIG. 14 is a schematic diagram of a traveling system of a DV (Digital Video) system VTR. The DV-type magnetic recording / reproducing apparatus includes, as a multi-magnetic head 76, a rotary drum device 86 equipped with the multi-magnetic head according to the sixth embodiment of the present invention, a supply reel 87, a take-up reel 89, rotating posts 88, 84, 74, 78, 79, 82, inclined posts 75, 77, capstan 80, pinch roller 8
1 is included. 85 is a magnetic tape.

Magnetic tape 85 wound on supply reel 87
The multi-magnetic head 76 mounted on the rotary drum device 86 is driven by a retracting operation by a pinch roller 81 and a capstan 80 and guided by inclined posts 75 and 77.
To the pinch roller 81 and the capstan 8
The tape is wound on the take-up reel 89 through the interval 0. The rotary drum device of this embodiment is of an upper rotary drum type, and the multi-magnetic head 76 is 15 μm from the side of the rotary drum.
m are protruded and two are attached.

In the magnetic recording / reproducing apparatus according to the configuration of this embodiment, since the wear can be suppressed by the protective film of the magnetic head 76, a high head output can be obtained by reducing the gap depth. Also, since the initial magnetic head protrusion amount can be made smaller than before, the tape damage can be reduced, and the tape is attracted by the effect of the groove on the magnetic head sliding surface, and the contact state between the magnetic head and the magnetic tape is improved. Can be kept.

When a drum device equipped with a multi-magnetic head as in this embodiment is rotated, for example, at twice the speed of the conventional one by changing the number of revolutions, the two magnetic heads are equally distributed at the conventional rotational speed. When the rotational speed is twice as much as that of the magnetic head, the magnetic head that comes into contact with the tape in advance has a greater wear amount than the magnetic head that comes in behind. This is probably because the contact state between the tape and the magnetic head changed due to the increase in the rotation speed of the drum.

The wear of the leading head due to this phenomenon is prevented by the magnetic recording / reproducing apparatus having the configuration of the present embodiment. That is, since the magnetic tape is attracted to the magnetic head by the negative pressure due to the effect of the groove formed on the sliding surface of the magnetic head, uneven wear is eliminated.

<< Embodiment 10 >> A method of manufacturing a magnetic head according to the present invention will be described with reference to FIGS. First, a ferromagnetic oxide substrate 90 of, for example, a Mn-Zn ferrite block whose surface is processed with good parallelism and good smoothness by lapping or the like as shown in FIG.
Prepare Then, a winding groove portion 91 as shown in FIG. 15B and a chamfered slope portion 92 at the end face are formed, and further a track defining track groove 9 as shown in FIG.
Form 3 The width of the ridge portion left uncut between the adjacent track grooves 93 substantially defines the track width. FIG. 15D is a side view of the magnetic head core block half 105 thus configured as viewed from the right side to the left side in FIG. 15C.

Next, a pair of substantially identical core blocks (half halves) which were processed in the same manner were prepared, and the upper surface 99 serving as a magnetic gap forming surface (either right or left in FIG. 15D) was prepared. Either or both, a predetermined thickness, preferably SiO2
16 (a) through a gap member composed of As shown in FIG. 16A, a pair of superposed core blocks is fixed with a jig (not shown) so that the mutual relationship does not shift.

A pair of core blocks 105, 105, which are overlapped and fixed by a jig as described above, are formed with V-shaped cross-sectional grooves 9 formed by facing the chamfered slope portions 92, 92 of each other.
Place it in the shape shown in FIG. 16 (b) ′ so that 2 ′ faces upward.
Thereafter, as shown in FIG.
A cylindrical adhesive glass 94 is placed in 2 ′ and on the V-shaped portion 91 ′ at the lower end of the winding groove 91 formed in the center of the pair of core blocks 105, 105, respectively. Add and heat at 700 ° C.

As a result of the heating, the adhesive glass 94 is melted as shown in FIG.
And a V-shaped portion 91 ′ at the lower portion of the winding groove 91, and
The pair of head cores 105, 105 are fixed.

Next, the core block composed of a pair of cores assembled and bonded in this manner is placed upside down as shown in FIG. 17 and sliced by a dicing saw at a cut surface shown by a dotted line to form a head chip one by one. Is obtained. The slice is cut in consideration of a predetermined azimuth angle.

Further, as shown in FIG. 18, the head chip 96 thus formed is bonded to a head base 95 preferably made of brass with an ultraviolet curable resin. The use of the ultraviolet curable resin is for curing the adhesive in a short time after a desired time. Next, the head is polished with a wrapping tape so that the radius of curvature of the sliding surface becomes an optimum value for the drum device to be mounted.

On the sliding surface of the magnetic head having the adjusted surface shape,
A groove in a desired direction is formed at a desired position, which is a feature of the present invention, using a dicing saw. For example, as shown in FIG. 19, a gap provided in a direction close to the rotation axis of the rotating drum is 300 μm on each side in the longitudinal direction.
Is formed, a total of two grooves 97a and 97b having a width of about 30 μm, a depth of about 60 μm, and a length of about 200 μm over the entire thickness of the head of preferably about 200 μm. Next, as shown in FIG. 20, a protective film 98 made of diamond-like carbon is formed to a thickness of 30 nm on the magnetic head sliding surface 96s by, for example, a plasma CVD method. Thereafter, winding (not shown) is performed on the magnetic core to complete the head.

In this embodiment, the method of manufacturing the magnetic head of the fifth embodiment has been described. However, the magnetic heads of the second and third embodiments can be manufactured by the same method. However, the direction, width, and depth of the groove are, of course, changed according to each embodiment. By attaching a plurality of these heads to the head base, a multi-magnetic head according to the sixth embodiment can be obtained.

Further, in this embodiment, the description has been made of the example in which SiO2 is used as the gap material. However, ZrO2, Ta2 O5,
Glass, Cr, or a composite thereof can be used. In this embodiment, an example was described in which a groove was formed after the head chip was bonded to the head base and the head sliding surface was polished, but before slicing in FIG. 17, a desired groove was formed. One head chip may be manufactured.

In this embodiment, an example in which a dicing saw is used as a groove processing method has been described. However, electric discharge machining, laser processing, photolithography, ion milling, and chemical etching are used to form grooves. A different forming method may be used. Since the depth of the groove can be changed by electric discharge machining or laser machining, magnetic heads of various shapes can be produced.

In each of the embodiments described above, the ferrite head and the MR head have been described as examples of the magnetic head, but according to the present invention, a laminated magnetic head composed of a laminated body of a non-magnetic layer and a magnetic layer. The same effect is obtained for a thin film magnetic head and a thin film magnetic head having a magnetoresistive element. Furthermore, in Examples 2, 3, 5 to 9, examples of forming a diamond-like carbon and a cubic boron nitride film as a protective film formed on a sliding surface have been described. In addition, SiC, CrN, diamond ,
Carbon, TiN, TiC, Si3 N4, Al2 O3, Ta
A thin film of C, ZrC or the like may be formed as a protective film by combining one or two or more thin films.

The thickness of the protective film is desirably 50 nm or less in consideration of spacing loss. The hardness of the protective film should be determined by the combination with the magnetic tape that comes in contact.
instruments, Inc.) Nano Indenter Xp (Nano Indent
er XP) is preferably 20 GPa or more. This device measures hardness while changing the indentation depth, and uses a Berkovich indenter made of diamond. The hardness obtained by this device is different from the Vickers hardness, and is converted to 1 / 94.59 of the Vickers hardness.

[0088]

As described above, according to the configuration of the magnetic head according to the first to sixth aspects of the present invention, it is possible to provide a magnetic head having excellent wear resistance and good contact with a magnetic tape. . Further, according to the configuration of the magnetic recording / reproducing apparatus according to the seventh to ninth aspects of the present invention, it is possible to provide a magnetic recording / reproducing apparatus which has excellent wear resistance and good contact with a magnetic tape by using the magnetic head.

[Brief description of the drawings]

FIG. 1 is an external view of a magnetic head according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating the relationship between the width of a sliding surface and the flatness of an envelope according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a relationship between a groove length and a groove depth according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating the relationship between the width of a groove and the flatness of an envelope according to the first embodiment of the present invention.

FIG. 5 is an external view of a magnetic head according to a second embodiment of the present invention.

FIG. 6 is a perspective view of a magnetic head according to a third embodiment of the present invention.

FIG. 7 is an external view of a magnetic head according to a third embodiment of the present invention.

FIG. 8 is an external view of a magnetic head according to a fourth embodiment of the present invention.

FIG. 9 is a diagram illustrating a relationship between a magnetic head according to a fourth embodiment of the present invention and a tape deformed shape according to a comparative example.

FIG. 10 is an external view of a magnetic head according to a fifth embodiment of the present invention.

FIG. 11 is an external view of a magnetic head according to a sixth embodiment of the present invention.

FIG. 12 is a schematic diagram of a traveling system of a magnetic recording and reproducing apparatus according to a seventh embodiment of the present invention.

FIG. 13 is a schematic diagram of a traveling system of a magnetic recording and reproducing apparatus according to an eighth embodiment of the present invention.

FIG. 14 is a schematic diagram of a traveling system of a magnetic recording and reproducing apparatus according to a ninth embodiment of the present invention.

FIG. 15 is a view showing a process of manufacturing a core half block in Example 10 of the present invention.

FIG. 16 is a view showing a step of abutting a pair of core halves before a step of welding with an adhesive glass in Example 10 of the present invention.

FIG. 17 is a diagram showing a position where the assembly in which a pair of core halves are butted in Example 10 of the present invention is sliced by a dicing saw.

FIG. 18 is an external view in which a head chip according to a tenth embodiment of the present invention is attached to a head base.

FIG. 19 is a diagram after a groove is formed on a head sliding surface according to a tenth embodiment of the present invention.

FIG. 20 is a view after a protective film is formed on a head sliding surface according to Embodiment 10 of the present invention.

[Explanation of symbols]

1a, 1b, 7a, 7b, 11a, 11b, 19a, 1
9b, 21a, 21b, 31a, 31b, 97a, 97
b, 106a, 106b Groove 2, 8, 12, 20, 22, 32 Gap 101 MR element 102 Protective layer 103 Terminal part 3, 9, 13, 98, 107 Protective film 4, 14, 17, 24, 29, 34 Glass 5, 15, 17, 25, 30, 35 windings 6a, 6b, 16a, 16b, 18a, 18b, 26
a, 26b, 36a, 36b, 37a, 37b Magnetic core 104, 105 Substrate 26 Magnetic head A 27 Magnetic head B 28, 95 Head base 40, 60, 87 Supply reel 41, 61, 86 Rotary drum device 42, 62, 89 Take-up reel 43, 44, 48, 49, 54, 52, 63, 64, 6
8, 69, 72, 74, 78, 79, 82, 88, 84
Rotating post 46, 66, 76 Magnetic head 45, 47, 65, 67, 75, 77 Inclined post 50, 70, 80 Capstan 51, 71, 81 Pinch roller 53, 83 Tension arm 55, 73, 85 Magnetic tape 90 Substrate 91 groove for winding 92 chamfered portion 93 track regulating groove 94 glass 96 head chip

Continuing on the front page (72) Inventor Eisai Sawai 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Ken Takahashi 1006 Odaka Kadoma Kadoma City, Osaka Matsushita Electric Industrial Co. (72) Inventor Hiromi Takeda 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. 5D111 AA01 AA13 AA19 AA23 BB28 DD03 DD06 GG09 JJ03 KK07 KK09

Claims (7)

[Claims] 1. A magnetic head mounted on a rotating drum and performing magnetic recording or reproduction by sliding in contact with a magnetic tape, wherein a sliding surface of the magnetic head in contact with the magnetic tape substantially extends in a rotating direction of the drum. Two grooves are formed at a predetermined interval, and a gap is formed in a sliding surface between the two grooves, and a width of a portion of the sliding surface of the magnetic head sandwiched between the two grooves is reduced. A magnetic head having a width of not less than a track width and not more than 100 μm, and a width of each groove is not less than 5 μm and not more than 50 μm. 2. The magnetic head according to claim 1, wherein a length of the groove formed on the sliding surface is equal to or less than a sliding length at which the magnetic head and the magnetic tape contact. 3. The magnetic head according to claim 1, wherein a protective film is formed on the sliding surface. 4. A rotary drum device having a rotary drum having any one of the magnetic heads according to claim 1, a rotary drum device having a fixed drum adjacent to the rotary drum, and a magnetic tape guided to the rotary drum device to fix the rotary drum. A magnetic recording / reproducing apparatus comprising: a rotating post and an inclined post for bringing the magnetic tape into contact with an outer peripheral surface of the drum and the rotating drum; and a capstan and a pinch roller for transferring the magnetic tape at a predetermined speed. . 5. A magnetic head mounted on a rotating drum and performing magnetic recording or reproduction by sliding in contact with a magnetic tape, wherein a sliding surface of the magnetic head in contact with the magnetic tape has a substantially rotating direction of the drum. Are formed at predetermined intervals with a gap interposed therebetween at a predetermined angle with a gap therebetween. The position of the groove in the drum rotation direction is within the range of the sliding portion where the magnetic head and the tape contact. (In the direction of rotation of the drum). 6. The magnetic head according to claim 5, wherein a protective film is formed on the sliding surface. 7. A rotating drum having the magnetic head according to claim 5, a rotating drum device having a fixed drum adjacent to the rotating drum, and a magnetic tape guided to the rotating drum device. A magnetic post comprising: a rotary post and an inclined post for bringing the magnetic tape into contact with the outer peripheral surfaces of the fixed drum and the rotary drum; and a capstan and a pinch roller for transferring the magnetic tape at a predetermined speed. Playback device.