JPH10198918A - Magnetic head and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic head and its manufacturing method that can record signals with the same frequency, the same phase, and the same recording level by means of multi-channel magnetic gap. SOLUTION: A front core 1 is built up by connecting a block material 4A and a block material 4B, and gap forming parts 4A1 and 4B1 are formed on each block material 4A and 4B, and junctions of the gap forming parts form magnetic gaps G. And other parts than the gap forming parts are fitted with non-magnetic material 6. Since all magnetic gaps G are formed with the junction of the block material 4A and 4B, each magnetic gap G can be positioned on a same line, and each gap depth can be matched to each other. Moreover, a magnetic field is induced to each magnetic gap from a same coil 8. Therefore, recording with the same frequency, the same phase, and the same recording level is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used in an apparatus for recording a servo signal on a magnetic tape used in a tape drive for serpentine data storage, and more particularly to a magnetic head having a plurality of magnetic gaps. And a method of manufacturing the same, which can be formed on the same line and at the same gap depth.

[0002]

2. Description of the Related Art A tape drive for data storage using a recording method called a serpentine method is used for a large-capacity data backup or the like, and a magnetic tape used in the tape drive controls a position of a magnetic head. Servo signals for the magnetic head are recorded in advance.
This servo signal is read and recorded on the magnetic tape while confirming the current position. Therefore, a magnetic head used in a data storage tape drive includes a data recording / reproducing unit that records a magnetic signal on a magnetic tape,
And a servo signal reproducing unit for reading a servo signal.

FIG. 7 shows an image of a recording pattern on a recording surface of a magnetic tape for a serpentine tape drive. Servo signals are recorded in advance on the servo tracks ST1, ST2, and ST3, and magnetic data is recorded in data areas T1, T2, T3, and T4 where no servo signals are recorded. In the data area T1, recording tracks R1 and R2 indicated by two dotted lines are shown, but a plurality of recording tracks are provided in the data area T1 having a predetermined width. This recording method is called a serpentine method. Hereinafter, the serpentine method will be described.

A magnetic head for a serpentine tape drive is provided with a servo signal reproducing section Hc for reading a servo signal and a data recording / reproducing section Hr as described above. When the magnetic tape T runs in the X1 direction when the servo signal reproducing unit Hc is at the position shown in (a), the data recording / reproducing unit Hr scans the recording track R1 of the data area T1 and follows the recording track R1. Magnetic data is recorded, or recorded data on the recording track R1 is reproduced. When the recording or reproduction of the recording track R1 is completed, the servo signal reproducing unit Hc shifts in the Y2 direction so as to be at the position (b), and together with the servo signal reproducing unit Hc, the data recording / reproducing unit Hr also moves in the Y2 direction. shift. Then, the running direction of the magnetic tape T is switched to the X2 direction,
The data recording / reproducing section Hr records or reproduces a signal along the recording track R2. By repeating this, a signal is recorded and reproduced in a data area T1 having a predetermined width in a state where the direction is alternately changed in the X direction on a plurality of tracks.

[0005] The servo signal reproducing section Hc and the data recording /
The reproducing section Hr includes all the servo tracks ST1, ST2,
ST3 and data areas T1, T2, T3, T4 are provided corresponding to all data areas T1, T2, T3, T4.
At 4, the recording or reproduction of magnetic signals along a plurality of tracks is performed simultaneously and similarly.

The servo tracks ST1, ST2, ST
3, servo signals having the same frequency and the same recording level (recording intensity) are recorded. When the servo signal reproducing unit Hc reads the servo signal, the X1 of the magnetic tape T is read.
The traveling speed in the direction and the X2 direction is controlled to be constant. Further, the size of the servo signal reproducing unit Hc overlapping the servo tracks ST1, ST2, and ST3 is different between when the servo signal reproducing unit Hc is at the position (a) and when the servo signal reproducing unit Hc is at the position (b). The reproduction output level from the servo signal reproduction unit Hc at the position (a) differs from the reproduction output level from the servo signal reproduction unit Hc at the position (b). The position of the servo signal reproducing unit Hc and the recording / reproducing unit Hr in the Y1-Y2 direction is controlled by the difference in the magnitude of the reproduction output level of the servo signal. That is, the running speed of the magnetic tape is controlled and the tracks R1, R2 in the data areas T1, T2, T3, T4 are controlled by the servo signals recorded on the servo tracks ST1, ST2, ST3.
The position of 2 ... can be controlled.

[0007]

As shown in FIG. 7, in a magnetic tape for a serpentine tape drive,
The servo tracks ST1, ST2, and ST3 must all be recorded with the same track width Tw and the same track pitch Tp. Also, each servo track ST
The servo signals recorded in ST1, ST2, and ST3 must all have the same frequency, the same phase, and the same recording level (same recording intensity). Therefore, when a magnetic tape for a serpentine tape drive is supplied to the market, it is necessary to record a servo signal that satisfies all of the above requirements, and a dedicated magnetic head for recording this servo signal is required. is there. The characteristics required of this magnetic head are as follows.

[0008] All the servo tracks ST1, ST2,
To make the servo signals recorded in ST3 have the same phase,
It is necessary to form a magnetic core such that a plurality of magnetic gaps G provided on a magnetic head are aligned. In order for the servo signals recorded on all the servo tracks ST1, ST2 and ST3 to have the same recording level, the magnetic gap depth (magnetic gap depth) Gd in all the magnetic gaps corresponding to the servo tracks must be the same. No. In order for the servo signals recorded on all the servo tracks ST1, ST2, ST3 to have the same frequency, it is necessary to apply the same recording magnetic field to a plurality of magnetic gaps with one coil.

Conventionally, as a multi-channel magnetic head capable of simultaneously recording on a plurality of tracks, a magnetic head used in a stereo cassette tape player or the like is generally used. In this type of magnetic head, a rectangular window is formed in a shield case that serves as a sliding surface for a magnetic tape, and a plurality of magnetic cores are individually provided in the window. Further, a shield plate is provided between the magnetic cores, so that crosstalk between the magnetic cores can be prevented. A bobbin is provided at the base of each magnetic core, and a coil in which a covered conductor is wound with a predetermined number of turns is formed on each bobbin.

As described above, in the conventional magnetic head, since a plurality of magnetic cores are individually provided, and the coils are individually wound around the respective magnetic cores, a multi-channel magnetic gap is formed on the same line. Forming into,
In addition, it is difficult to set the same magnetic gap depth for all magnetic cores in terms of manufacturing. It is also difficult to match recording signals applied to each magnetic core to the same frequency. Further, in a structure in which a plurality of magnetic cores are positioned and mounted in the shield case, the track pitch Tp of the magnetic gap of each channel depends on the assembly accuracy, and therefore, there is a limit to increasing the accuracy of the track pitch Tp. There is.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and provides a magnetic head capable of recording signals at the same frequency, the same phase and the same recording level by a multi-channel magnetic gap, and a method of manufacturing the same. It is intended to provide.

It is another object of the present invention to provide a magnetic head and a method of manufacturing the same, which can improve the accuracy of the track pitch of a multi-channel magnetic gap.

[0013]

According to the present invention, there is provided a magnetic head having a front core, a back core, and a coil portion, wherein the front core is formed by joining two block members made of a magnetic material, In each block material, a plurality of gap forming portions appearing on the sliding surface with the recording medium are integrally formed at intervals, and the gap forming portions of each block material are joined at the joining portion of the two block materials. Being
A plurality of magnetic gaps located on the same line are formed.

In the above, on the sliding surface with the recording medium,
It is preferable that the portion where the gap forming portion does not appear is filled with a non-magnetic material, and the gap forming portion and the surface of the non-magnetic material are processed to the same surface.

In this case, in the portion filled with the non-magnetic material, the two block members are formed in a concave shape in the front core from a sliding surface with the recording medium, and the depth of the concave shape is reduced. It is necessary that the gap forming portions be equal to or larger than the gap depth of the joined magnetic gap.

Further, the interval between the outermost gap forming portions of the plurality of gap forming portions is T2, and the width in the same direction as the interval T2 of the back core joined to the front core is T3. Then, it is preferable that T3> T2.

FIG. 2 is an exploded perspective view showing the structure of a front core, a coil portion, and a back core when the magnetic head of the present invention is disassembled. A recording magnetic field generated from the coil unit 2 shown in the drawing is applied to the back core 3, and subsequently, the recording magnetic field is applied from the back core 3 to the front core 1. At this time, if the width dimension T3 of the back core 3 is larger than the width dimension T2 between the magnetic gaps formed at both ends of the three magnetic gaps G provided in the front core 1, A recording magnetic field of the same strength is uniformly applied to the three magnetic gaps.

According to the present invention, in a method of manufacturing a magnetic head having a front core, a back core, and a coil portion, a groove is formed in at least one of the two magnetic material blocks constituting the front core. A step of processing, a step of facing the surfaces of the two block materials on which the grooves are formed, and joining the two block materials with a bonding material filled in the groove portions, and a surface where a joining portion of the two block materials appears Is a sliding surface side with the recording medium, a plurality of portions of both block material appearing on the sliding surface side is a gap forming portion, a step of partially shaving both block materials in a portion other than the gap forming portion, A step of filling the cut portion of the block material with a nonmagnetic material, and a process of forming the gap forming portion and the nonmagnetic material of both block materials on the same surface to form a sliding surface with a recording medium. If, joining the back core in the front core has been completed by the process, it is characterized in that and has a step of attaching the coil section.

In the above method of manufacturing a magnetic head, it is preferable that when the portions other than the gap forming portions of the two block members are cut, the cutting is performed to a depth where the grooves appear.

Further, it is possible to form a metal magnetic film at the joint between the two block members before joining the two block members.

The magnetic head according to the present invention is used for recording servo signals on a plurality of tracks on a magnetic tape for a serpentine tape drive.

According to the present invention, in a method of manufacturing a magnetic head, particularly, a method of manufacturing a front core, a groove is formed in at least one of two magnetic material block members, and these are joined to each other. In the magnetic gap, the magnetic gaps are located on the same line, the gap depth can be the same in all magnetic gaps, a plurality of magnetic gaps are formed by a common front core, and a common coil portion is used. This enables magnetic recording with the same phase, the same frequency, and the same recording level in each magnetic gap.

Further, since a magnetic gap in which a plurality of magnetic gap forming portions are combined is formed on the front core where the two block materials are joined, the track width Tw and the track pitch Tp of each magnetic gap are reduced. , And Tw and Tp can be set with high accuracy.

[0024]

FIG. 1 is a sectional view of a magnetic head according to the present invention, FIG. 2 is an exploded perspective view showing a main part of the magnetic head, and FIGS. 3 to 5 are perspective views showing a manufacturing process of a front core in order. FIG. 6 is a sectional view taken along line VI-VI in FIG.
In a serpentine tape drive, recording / reproduction is performed simultaneously while controlling the position of a magnetic head by a servo signal recorded on a magnetic tape. The magnetic head described below applies a servo signal at the same frequency, same phase, and same recording level to the positions of a plurality of servo tracks ST1, ST2, and ST3 on the magnetic tape T for a serpentine tape drive shown in FIG. Used to record.

Reference numeral 1 shown in FIGS. 1 and 2 is a front core, and the surface of the front core 1 is a sliding surface 1a for a magnetic tape. The sliding surface 1a of the front core 1 is polished (wrapped) and has a curved surface shape having a constant curvature. The front core 1 is constituted by joining single-crystal ferrite blocks 4A and 4B, and the blocks 4A and 4B have the same width dimension T1, the same length dimension L1, and the same thickness dimension h6.
It is.

As shown in FIG. 2, in the block members 4A and 4B constituting the front core 1, 3
A strip gap forming portion 4A1 and a gap forming portion 4B1 are formed. The gap forming portion 4A1 and the gap forming portion 4B1 are joined via a gap material to form three magnetic gaps G. Further, portions other than the gap forming portions 4A1 and 4B1 on the sliding surface 1a are cut off to form concave portions 4A2 and concave portions 4B2. The recesses 4A2 and 4B2 are filled with a nonmagnetic material 6 such as a glass material. Then, the surfaces of the gap forming portions 4A1 and 4B1 and the nonmagnetic material 6 are polished to the same surface to form the sliding surface 1a.

1 and 6, the gap forming portion 4A
1 and 4B1 are shown in cross section. Block material 4
A groove 4d is formed in the facing surface 4c of B, and an inner wall of the groove 4d on the sliding surface 1a side is an inclined surface 4a. In the gap forming portions 4A1 and 4B1, the block material 4
The opposing surface 4c of the block B in which the groove 4d is not formed and the opposing surface 4b of the block material 4A are joined with a width dimension h4 to form a magnetic gap G. The width dimension h4 is a gap depth (gap depth) Gd.

As shown in FIG. 6, the depth of the recess 4A2 of the block member 4A and the recess 4B2 of the block member 4B from the sliding surface 1a is greater than the width dimension h4, and the predetermined gap depth Gd The magnetic gap G is formed only in the three gap forming portions 4A1 and 4B1, and the magnetic gap G is not formed in the concave portions 4A2 and 4B2 by the block members 4A and 4B. As shown in FIG. 1, the groove 4 of the block material 4B
The inclined surface 4a of d is filled with a joining material 5 such as a joining glass, and the joining materials 5 join the block members 4A and 4B.

As shown in FIG. 1, a metal magnetic film 17 is formed on the opposing surface 4b of the block member 4A and the opposing surface 4c of the block member 4B. And 4c are joined via a non-magnetic gap material such as glass to form a magnetic gap G, which is a so-called MIG (Metal).
In Gap) structure magnetic head. The metal magnetic film 17 may be a conventionally used sendust or the like, but it is more preferable to use one of the following two types of soft magnetic materials.

(1) Consisting of a composition formula of Fe—Xa—Mb—Zc—Td, X is one or both of Si and Al, and M is selected from a metal group consisting of Zr, Hf, Nb and Ta. Z is one or both of C and N, and T is Cr, Ti, Re, Ru, R
h, at least one metal selected from Ni, Co, Pd, Pt, and Au, 0.5 ≦ a ≦ 25 (atomic%), 1 ≦ b ≦ 10 (atomic%), 0.5 ≦ c ≦ 15 (atomic%), 0 ≦ d ≦ 10 (atomic%), the balance being Fe atomic%
And includes a crystal of a carbide or a nitride of the metal group M.

(2) Fe-Sie-Alf-Mb-Zc-T
and M is Zr, Hf, Nb,
At least one metal selected from the group consisting of Ta; Z is one or both of C and N; T is Cr and T;
i, Re, Ru, Rh, Ni, Co, Pd, Pt, Au
Represents at least one metal selected from the group consisting of 8 ≦ e
≦ 15 (atomic%), 0.5 ≦ f ≦ 10 (atomic%), 1 ≦
b ≦ 10 (atomic%), 0.5 ≦ c ≦ 15 (atomic%), 0
.Ltoreq.d.ltoreq.10 (at.%), The balance being Fe at.%, And includes carbide or nitride crystals of metal group M.

In the above-mentioned soft magnetic material, Fe is a main component and is an element which bears magnetism. The particles made of the carbides or nitrides of the metal group M have an effect of suppressing the growth and coarsening of a crystal containing Fe as a main component, and improving the heat resistance of soft magnetic properties. Further, the addition amount is preferably 1 mol% or more, but if it exceeds 10 mol%, the saturation magnetic flux density Bs decreases, which is not preferable. C or N combines with the metal group M to generate carbide or nitride. The addition amount is preferably 0.5 mol% or more, but if it exceeds 15 mol%, the saturation magnetic flux density Bs decreases, which is not preferable.

The environmental resistance is improved by adding Al. Al forms a solid solution with the Fe crystal and increases the specific resistance. The growth of crystal grains is slowed down, and the magnetocrystalline anisotropic energy is reduced. Heat resistant temperature rises. The addition amount is preferably 0.5 mol% or more,
If it exceeds 1%, the magnetostriction .lambda.S becomes too large, and the saturation magnetic flux density Bs also decreases.

By adding Si, the magnetostriction λS, which is increased by the addition of Al, is reduced. The magnetic film tends to be made amorphous during sputtering. Therefore, in order to make the magnetic film easily amorphous, a large amount of carbide or nitride was conventionally contained.However, the content of carbide or nitride can be reduced, and the saturation magnetic flux density due to carbide or nitride can be reduced. Si that can suppress the decrease of Bs is Fe
Solid solution in the crystal and the specific resistance increases. The growth of crystal grains slows down, and the crystal magnetic anisotropy energy decreases.
The addition amount at which the heat resistance temperature increases is preferably 0.5 mol% or more, but if it is 25 mol% or more, the saturation magnetic flux density Bs decreases, which is not preferable.

Further, also improved environmental resistance while at the same time reduce the magnetostriction λS simultaneously added in combination of Si and Al in the 0 to 3.0 × 10 ^-6. However, in order to further reduce the magnetostriction .lambda.S, it is preferable that (Si / Al) be 3/2 or more. The soft magnetic material described above has magnetic characteristics such as low magnetostriction, high saturation magnetic flux density, high magnetic permeability, and high reliability due to corrosion resistance.

Although three gap forming portions 4A1 and 4B1 are provided on the sliding surface 1a of the front core 1 shown in FIG. 2, the gap forming portions 4A1 and 4B1 are further provided to cope with high density. 4B1 may be increased. The track pitches Tp of the gap forming portions 4A1 and 4B1 are constant, all the gap forming portions 4A1 and 4B1 have the same width, and the track width Tw of the three magnetic gaps G is the same. In the front core 1, the block members 4A and 4B are joined, and the magnetic gaps G are formed by the gap forming portions 4A1 and 4B1 formed in the block members 4A and 4B. The gaps G are located on the same line, and the gap depths Gd of the magnetic gaps G can be aligned to have the same dimensions.

Reference numeral 2 shown in FIGS. 1 and 2 is a coil unit. As shown in FIG. 2, the coil unit 2 has a coil 8 wound around a bobbin 7. The bobbin 7 has a hole 7a into which the foot 3a of the back core 3 is inserted. Metal members 9, 9 are embedded in the bobbin 7. The metal member 9,
One end of 9 is an external terminal 10a, 10b, and the other end is a winding portion 11a, 11b for winding and soldering the winding of the coil 8.

Reference numeral 3 shown in FIGS. 1 and 2 is a back core made of polycrystalline ferrite, and the back core 3 is provided with feet 3a and 3b. As shown in FIG. 1, the foot 3a is inserted into the hole 7a of the bobbin 7, and the front core 1
And the other foot 3b
Is joined to the back surface of the block 4B. The width dimension of the back core 3 is T3, and the distance between the gap forming sections 4A1 and 4B1 located at the both ends of the three gap forming sections 4A1 and 4B1 formed on the sliding surface 1a of the front core 1. Assuming that the dimension is T2, T3> T2, and the recording magnetic field induced from the coil 8 to the back core 3 is applied to each of the three gap forming portions 4A1 and 4B1.
It is provided with the same magnetic flux density.

Reference numeral 12 shown in FIG. 1 denotes a holder, and a window 12a is provided on a sliding surface with the magnetic tape. Surface on which window 12a is formed (sliding surface with magnetic tape)
Is a curved surface having the same curvature as the sliding surface 1a of the front core 1. The front core 1 is inserted into the holder 12,
Next, the coil part 2 and the back core 3 are inserted into the holder 12. The back core 3 has its feet 3a, 3b abutted against the back surfaces of the blocks 4A, 4B constituting the front core 1, and the feet 3a of the back core 3 are inserted into holes 7a of the bobbin 7. Finally, a leaf spring 13 for fixing the front core 1, the coil unit 2, and the back core 3 in the holder 12
Is inserted to complete the magnetic head.

Next, a method of manufacturing the front core 1 constituting the magnetic head of the present invention will be described with reference to FIGS. In the process of manufacturing the front core 1, single-crystal ferrite blocks 4A and 4B whose end faces are L1 × h1 and whose length is longer than T1 are used. The opposing surface 4b of the block 4A and the opposing surface 4c of the block 4B are polished (wrapped) so as to be flat.

As shown in FIG. 3A, a groove 4d is formed in the opposing surface 4c of one of the block members 4B. The width dimensions of the opposing surface 4c of the portion where the groove 4d is not machined are indicated by h2 and h3. An inclined surface 4a is formed on one inner wall of the groove 4d. Note that the remaining width dimension h2 of the facing surface 4c is a portion that affects the gap depth Gd of each magnetic gap G of the front core 1 when completed. Therefore, when machining the groove 4d and the inclined surface 4a, the width h2 can be set at any position in the longitudinal direction of the block 4B.
Is performed with a high degree of accuracy so that is constant.

As shown in FIG. 3B, two blocks 4A and 4B having the same dimensions are used. FIG.
In (C), the opposing surface 4b of the block member 4A and the opposing surface 4c of the block member 4B are arranged in the sputter apparatus so as to be on the same surface, and the surface of the opposing surfaces 4b and 4c is formed as a base layer of SiO. _Two films are formed by sputtering, and a metal magnetic film 17 is formed thereon. Then, a gap material is formed on the surface of the metal magnetic film 17, and a bonding material 5 is filled in a portion of the inclined surface 4a of the groove 4d, and as shown in FIG. 3D, the block material 4A and the block material 4B are formed. Are joined with the opposing surfaces 4b and 4c facing each other. The joined body 1 'in which the block members 4A and 4B are joined by the joining step of FIG.
A joining portion 14 in which the opposing surfaces 4b and 4c are joined via a gap material appears on the front surface 1a 'of the device so as to be linear in the longitudinal direction.

Next, as shown in FIG. 4A, recesses 4A2 and 4B2 are formed on the surface 1a 'of the joined body 1'. The recesses 4A2 and 4B2 are formed in the gap forming portion 4A.
The blocks 4A and 4B are formed by partially cutting the block members 4A and 4B while leaving the dummy gap forming portions 4A3 and 4B3 at both ends in the longitudinal direction while leaving 1 and 4B1.
At this time, the widths (track widths) Tw of the gap forming portions 4A1 and 4B1 are all processed to have the same size, and the pitch (track pitch) Tp between the gap forming portions 4A1 and 4B1 is also the same. Process. In this manufacturing method, the gap forming portions 4A1 and 4B1 are formed by cutting the joined body 1 'in which the block members 4A and 4B are joined. In this mechanical cutting, the track width Tw and the gap width are reduced. It is easy to set the track pitch Tp with high accuracy.

The depth d of the recesses 4A2 and 4B2 from the surface 1a 'is greater than the width dimension h2. That is, the joined body 1 'is scraped off until the groove 4d formed in the block material 4B or at least the depth d at which the inclined surface 1a appears to form the concave portions 4A2 and 4B2. As a result, a magnetic gap G having a depth of h2 is formed at the junction between the three gap forming portions 4A1 and 4B1, and a dummy gap G 'is also formed at the dummy gap forming portions 4A3 and 4B3. In FIG. 4B, the recess 4
A2 and 4B2 are filled with a non-magnetic material 6 such as molten glass. In FIG. 5A, the surface 1a 'of the joined body 1' is shown.
Is polished into a curved surface. As a result, the gap forming section 4A
The surfaces 1 and 4B1, the dummy gap forming portions 4A3 and 4B3, and the surface of the non-magnetic material 6 become the same surface, and the sliding surface 1a is formed.

Further, the dummy gap forming portions 4A3, 4A at both ends in the longitudinal direction are cut along the cutting lines CL shown in FIG.
B3 is removed and the width dimension becomes T1. Further, in FIG.
The portion indicated by is sliced and removed, and as shown in FIG. 5B, a front core 1 having a thickness h6 and a width T1 is completed. In each of the three magnetic gaps G, the width dimension h4 (gap depth Gd) where the opposing surfaces 4b and 4c are joined has the same dimension. This front core 1
Then, the coil part 2 and the back core 3 are assembled in the holder 12 to complete the magnetic head.

In the front core of this magnetic head, two block members 4A and 4B are joined,
A gap forming portions 4A1 and 4B1 are formed at A and 4B, and a magnetic gap is formed at a junction between the gap forming portions 4A1 and 4B1. Therefore, the three magnetic gaps G are located on the same line, and the gap depth Gd of each magnetic gap G can be matched with high accuracy. Further, it is easy to set the track width Tw and the track pitch Tp with high precision by mechanical cutting.

Therefore, if this magnetic head is used, it is possible to record servo signals on the magnetic tape T for a serpentine tape drive shown in FIG. 7 at the same track width Tw and at a constant track pitch Tp. is there. Each magnetic gap G is provided with a recording magnetic signal from the common coil unit 2 so that each servo track ST1,
Signals of the same frequency can be recorded in ST2 and ST3. Further, since the magnetic gap G is located on the same line, servo signals of the same phase can be recorded on each of the servo tracks ST1, ST2, ST3. Each magnetic gap G
In this example, the gap depth Gd matches with high precision, the track width Tw is uniform, and each magnetic gap G is formed by the integral block members 4A and 4B, so that each servo track has the same recording level. It is possible to record servo signals. It should be noted that the magnetic head of the present invention is not limited to recording servo signals on a tape for a serpentine tape drive, but can be used for any device that records the same signal on multiple channels. .

[0048]

According to the present invention described in detail above, the front core constituting the magnetic head has a structure in which two block members are joined and a plurality of gap forming portions are formed by the block members. The magnetic gaps formed by the plurality of gap forming portions can be located on the same line, and the gap depth can be made uniform. Therefore, signals of the same frequency, the same phase, and the same recording level can be recorded on a plurality of tracks.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the structure of a magnetic head according to the present invention;

FIG. 2 is a front core constituting the magnetic head of the present invention;
Perspective view showing the structure of the coil portion and the back core,

3 (A) to 3 (D) show a method of manufacturing a front core according to the present invention, and are perspective views showing a process until a joined body is formed by two block materials;

4 (A) and 4 (B) are views showing a method for manufacturing a front core of the present invention, and are perspective views showing a process of forming a gap forming portion in a joined body.

FIGS. 5A and 5B are perspective views showing a method for manufacturing a front core of the present invention, showing a step of processing a sliding surface with a recording medium and a final cutting step;

FIG. 6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is an image diagram showing a recording pattern on a magnetic tape by a serpentine method,

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front core 1 'Joined body 1a Sliding surface 2 Coil part 3 Back core 4A, 4B Block material 4A1, 4B1 Gap formation part 4A2, 4B2 Concave part 5 Joining material 6 Nonmagnetic material 7 Bobbin 8 Coil 12 Holder 13 Plate spring 17 Metal Magnetic film G Magnetic gap Gd Gap depth Tw Track width Tp Track pitch

Claims (7)

[Claims] 1. A magnetic head having a front core, a back core, and a coil portion, wherein the front core is formed by joining two block materials made of a magnetic material, and each block material has a recording medium. A plurality of gap forming portions appearing on the sliding surface are integrally formed with an interval therebetween, and the gap forming portions of the respective block materials are joined at the joining portion of the two block materials, and are located on the same line. A magnetic head, wherein a plurality of magnetic gaps are formed. 2. A non-magnetic material is filled in a portion where the gap forming portion does not appear on a sliding surface with a recording medium, and the gap forming portion and the surface of the non-magnetic material are machined into the same surface. The magnetic head according to claim 1, wherein: 3. In a portion filled with the non-magnetic material, both block members are formed in a concave shape in a front core from a sliding surface with a recording medium, and the depth of the concave shape is:
3. The magnetic head according to claim 1, wherein the gap forming portions have a gap depth equal to or greater than a gap depth of the joined magnetic gap. 4. The interval between the outermost gap forming portions of the plurality of gap forming portions is T2, and the width of the back core joined to the front core in the same direction as the interval T2 is T3. 2. The method according to claim 1, wherein T3> T2.
4. The magnetic head according to any one of items 3 to 3. 5. A method for manufacturing a magnetic head having a front core, a back core, and a coil portion, wherein a groove is formed in at least one of two magnetic material blocks constituting the front core. A step of facing the surfaces of the two block materials on which the grooves are formed, and joining the two block materials with a bonding material filled in the groove portions; And a step of partially shaving both block materials at a portion other than the gap formation portion, wherein a plurality of portions of both block materials appearing on the slide surface side are defined as gap forming portions. Filling the shaved portion with a non-magnetic material; processing the gap forming portions of the two block materials and the non-magnetic material into the same surface to form a sliding surface with a recording medium; Joining the back core to the front core completed by the process and attaching the coil portion. 6. The method of manufacturing a magnetic head according to claim 5, wherein, when shaving portions other than the gap forming portions of both block members, the portions are cut to a depth where the grooves appear. 7. A metal magnetic film is formed at a joint between the two block members before joining the two block members.
The manufacturing method of the magnetic head described.