JPH0973604A - Magnetic head - Google Patents

Abstract

(57) [Abstract] [Purpose] A magnetic head capable of achieving uniform wear of a tape sliding surface by changing the tape contact width of the tape sliding surface in proportion to the degree of wear of the core half. provide. A pair of core halves 1 and 2 coupled via a gap spacer film 4 and tip portions 13 of the core halves 1 and 2,
The gap G is formed between the gaps 23, and the arc-shaped tape sliding surface 3 is formed on the tip surfaces 30, 31 of the tip portions 13, 23 across the gap G. The tape contact width L of the tape sliding surface 3 is proportional to the degree of wear of the core halves 1 and 2, and gradually increases from the left end to the right end of the tape sliding surface 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head applied to a magnetic recording / reproducing apparatus such as a VTR, and more particularly to a magnetic head having a pair of core halves having different degrees of wear.

[0002]

2. Description of the Related Art Conventionally, as this type of magnetic head, for example, there is one shown in FIG. In FIG. 8, reference numerals 110 and 120 are core halves of the same shape formed of a single crystal material, and these core halves 110 and 120 are bonded so as to face each other. And the core half 11
A gap G in which a space film is inserted is provided between the tip portions 111 and 121 of 0 and 120, and an arc-shaped tape sliding surface 130 is formed so as to sandwich the gap G. Specifically, the sliding portion 112 that curves upward toward the gap G is formed on the tip portion 111 of the core half body 110, and the sliding portion 122 that curves downward from the gap G forms the tip portion of the core half body 120. 121 is formed. The sliding portions 112 and 122 form a tape sliding surface 130 having a constant tape contact width L. With this configuration, the tape sliding surface 130
Tape 100 running in the direction of the arrow while touching the magnetic tape
Information is recorded / reproduced in the gap G with respect to the (two-dot chain line).

[0003]

However, the above-mentioned conventional magnetic head has the following problems. Since the core halves 110 and 120 are formed of a single crystal member, when the core halves 110 and 120 have different crystal axis directions, the wear characteristics of the sliding portion 112 and the wear characteristics of the sliding portion 122 are different. Will be different. That is, the sliding portion 1
When the wear degree of 22 is larger than the wear degree of the sliding portion 112, the tape contact width L is constant.
Due to long-term use, the sliding portion 122 side wears more than the sliding portion 112 side, and uniform wear cannot be achieved. As a result, the shape of the tape sliding surface 130 is deformed, and a gap is generated between the magnetic tape 100 and the gap G, which causes a problem in recording and reproducing on the magnetic tape 100.

The present invention has been made in order to solve the above-mentioned problems, and the width of the tape contact surface of the tape sliding surface is changed in proportion to the degree of wear of the core half to make the tape sliding surface uniform. An object is to provide a magnetic head that can achieve wear.

[0005]

In order to solve the above-mentioned problems, a magnetic head of the present invention comprises a first core half and a second core attached so as to face the first core half. A half body, a gap formed between the tip portions of the first and second core halves, and the first and second gaps sandwiching the gap.
In a magnetic head having a substantially arcuate tape sliding surface formed on the front end surface of the core half, the tape contact width of the tape sliding surface is determined by the wear of the first and second core halves. The configuration is set so that it changes in proportion to the degree.

According to the present invention, the tape contact width of the tape sliding surface is set so as to change in proportion to the degree of wear of the first and second core halves. The surface pressure of the tape applied to the sliding surface portion is smaller than the surface pressure of the tape applied to the tape sliding surface portion having the smaller degree of wear. Therefore, the amount of wear of the tape sliding surface portion having the higher degree of wear and the amount of wear of the tape sliding surface portion having the lower degree of wear become substantially equal, and the tape sliding surface is evenly worn.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a magnetic head according to an embodiment of the present invention. As shown in FIG. 1, the magnetic head according to the present embodiment includes a core half body 1 (first core half body) on the left side and a core half body 2 (opposed to the right side of the core half body 1). Second core half). And, between the tip ends of these core halves 1 and 2,
A gap G is provided, and a substantially arcuate tape sliding surface 3 is formed so as to sandwich the gap G.

Specifically, the core half 1 has a U-shaped guide groove 10 on the upper left side, and a winding groove 11 and a glass groove 12 on the upper and lower sides on the right side. Further, an arc-shaped tip portion 13 that protrudes from the left end toward the gap G side is provided on the upper portion of the core half body 1. On the other hand, the core half 2 has a symmetrical shape with the core half 1. That is, there is a guide groove 20 having the same shape as the guide groove 10 on the upper right side, and a winding groove 11 and a glass groove 12 on the upper and lower sides on the left side.
It has a winding groove 21 and a glass groove 22 of the same shape as the above, and an arcuate tip portion 23 protruding upward from the right end toward the gap G side is provided on the upper part of the core half body 2. In these core halves 1 and 2, the winding grooves 11 and 21 have a surface direction (11
1) and the surface direction of the tips 13, 23 is (211)
Are formed of single crystal Mn-Zn ferrite, and are bonded in a state of facing each other. That is, SiO2, Ta2 O5 are formed between the facing surfaces forming the gap G.
, ZrO2, Au, Pt, a gap spacer film 4 of glass or the like is interposed, and the core halves 1 and 2 are joined by the glass 5 for sealing in the track width regulating groove 6.

The tape sliding surface 3 is composed of the tip surface 30 of the tip portion 13 of the core half body 1 and the tip surface 31 of the tip portion 23 of the core half body 2, and the magnetic tape 100 is indicated by an arrow. Thus, the tape sliding surface 3 is run from the left to the right. The tape contact width L of the tape sliding surface 3 is set to change in proportion to the degree of wear of the core halves 1 and 2. That is, as shown in FIG. 7, the directions of the crystal axes V1 and V2 of the core halves 1 and 2 are [110] (VH
S direction) faces the gap surface M side at a predetermined angle,
The degree of wear due to the contact running of the magnetic tape 100 is
3 is larger than the tip portion 13. Therefore, as shown in FIG. 1, the tape contact width L of the tape sliding surface 3 is set to be the minimum width at the left end and gradually increase toward the right side. Therefore, the surface pressure applied to the tip surface 31 when the magnetic tape 100 is running is smaller than the surface pressure applied to the tip surface 30. Although not shown, a coil for generating a magnetic field in the gap G is wound around this magnetic head through a winding hole constituted by winding grooves 11 and 21.

Now, a method of manufacturing the magnetic head shown in FIG. 1 will be described. 2 to 6 show this manufacturing process. First, as shown in FIG. 2, a substrate 1 ′ and a core half 2 for a core half 1 made of a single crystal member of Mn—Zn ferrite.
The winding grooves 11 and 21 and the glass grooves 12 and 22 are engraved on each side of the substrate 2'for use. At this time, the winding grooves 11 and 21
The surface direction of the tape is (111), and the surface 3 for the tape sliding surface 3
The surface directions of -1 'and 3-2' are (211). Then, as shown in FIG. 3, track width regulating grooves orthogonal to the winding grooves 11 and 21 and the glass grooves 12 and 22 are formed in the substrate 1'and the substrate 2 ', and the substrate 1'and the substrate 2'are formed. Mirror surface is applied to the butt surface with. Then, on this processed surface, S
A gap spacer film 4 of iO2, Ta2 O5, ZrO2, Au, Pt, glass or the like is formed by a vacuum thin film forming method such as sputtering.

Then, as shown in FIG. 4, the substrate 1'so that the gap spacer films 4 face each other and contact each other.
And the substrate 2 '. In this state, the winding groove 11,
The glass 5 for sealing is inserted into the winding hole formed by 21 and the glass hole formed by the glass grooves 12 and 22, and heat-treated. As a result, the substrate 1 ′ and the substrate 2 ′ are integrally combined and the core block having the gap G is formed. Then, the surfaces 3-1 'and 3-2' of the core block are cut into an arc shape to form a curved surface 3'for the tape sliding surface 3 as shown in FIG. , 2
Mark 0.

Finally, after the tape sliding surface 3 is formed on the core block having such a surface 3 ', the core block is cut in the width direction to form a plurality of magnetic heads. Specifically, first, a plurality of grooves A having an angle θ are formed in the curved surface 3 ′ at equal intervals, as shown by the diagonally downward-sloping portion in FIG. Next, as shown by the hatched portion in the lower left of FIG. 6B, a plurality of grooves B are formed in the curved surface 3 ′ at equal intervals by cutting from one end of the groove A in the direction of the angle −θ. . As a result, the tape sliding surface 3 having a trapezoidal plan view curved in an arc shape.
Are formed in plural. Then, as shown in (c) of FIG. 6, a plurality of magnetic heads shown in FIG. 1 are formed by cutting the central portions of the grooves A and B in the width direction of the core block.

Next, the operation of the magnetic head of this embodiment will be described. As shown in FIG. 7, the magnetic tape 10
When 0 travels in the direction of the arrow while contacting the tape sliding surface 3, the magnetic field in the gap G causes information to be transferred to the magnetic tape 10.
It is recorded and played back at 0. Then, when the tape sliding surface 3 is not worn, or as shown by the broken line in FIG.
When 1 and V2 are parallel or perpendicular to the gap surface M, the apex of the curvature of the magnetic tape 100 running while contacting the tape sliding surface 3 is at the position P1 of the gap G.
Therefore, the magnetic tape 100 comes into complete contact with the gap G, and normal recording and reproduction are performed by the magnetic head.

However, the directions of crystal axes V1 and V2 [11
0] faces the gap surface M side at a predetermined angle,
The degree of wear of the tip surface 31 is larger than the degree of wear of the tip surface 30. Therefore, when used for a long period of time, as shown by the chain double-dashed line, the tip surface 31 side is greatly worn, and the apex of the curvature of the magnetic tape 100 moves to the position P2 on the tip surface 30 side. Therefore, a gap may be generated between the magnetic tape 100 and the gap G, which may hinder the recording and reproduction on the magnetic tape 100. However, in the magnetic head of this embodiment, the tape contact width L of the tape sliding surface 3 is L
Is the minimum width at the left end, and is set to gradually increase toward the right side. Therefore, the magnetic tape 10
The surface pressure applied to the front end surface 31 during zero travel becomes smaller than the surface pressure applied to the front end surface 30, and the wear amount on the front end surface 30 side and the wear amount on the front end surface 31 side become substantially uniform. As a result, the apex of the curvature of the magnetic tape 100 always exists at the position P1,
Normal recording and reproduction are performed by the magnetic head.

As described above, according to the magnetic head of this embodiment, the tip surface 30 and the tip surface 31 are evenly worn, and the apex of the curvature of the magnetic tape 100 always exists at the position P1. Normal recording / playback is performed by the head. As a result, the operational reliability of the magnetic head is improved and the life of the magnetic head is extended.

The present invention is not limited to the above embodiment, but various modifications and changes can be made within the scope of the invention. For example, in the present embodiment, the core halves 1 and 2 are made of Mn-Zn ferrite which is a single crystal member, but the present invention is not limited to such a single crystal member. Further, in the present embodiment, as shown in FIG. 1, the tape contact width L of the tape sliding surface 3 is set to be the minimum width at the left end and gradually increase toward the right side. The degree of wear of the tip portion 23 is the degree of wear of the tip portion 13
It is because it is larger than the wear degree of. Therefore, when the degree of wear of the tip portion 23 is smaller than that of the tip portion 13, the tape contact width L of the tape sliding surface 3 is the minimum width at the right end and gradually increases toward the left side. You can set it like this. Furthermore, in this embodiment, the core halves 1,
Although 2 is formed in a symmetrical shape, even if it is formed in an asymmetrical shape, the tape contact width L of the tape sliding surface 3 is set to the core half body 1,
If it is set to change in proportion to the degree of wear of 2,
As a matter of course, the same operational effect as in the symmetrical case can be obtained.

[0017]

As described above in detail, according to the present invention, the tape contact width of the tape sliding surface can be set to the first and second widths.
Since it is set to change in proportion to the degree of wear of the core half, it is possible to achieve uniform wear of the tape sliding surface, and as a result, improve the operation reliability of the magnetic head and extend its life. There is an excellent effect that can be achieved.

[Brief description of drawings]

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

FIG. 2 is a perspective view showing a pair of substrates for core halves in which winding grooves and glass grooves are engraved.

3 is a perspective view showing a state in which a gap spacer film is formed on the substrate of FIG.

FIG. 4 is a perspective view showing a core block in which the substrates of FIG. 3 are joined together.

5 is a perspective view showing a state in which a curved surface for a tape sliding surface and a guide groove are formed on the core block of FIG.

6 is a plan view showing a method of forming a tape sliding surface on the curved surface of FIG. 5, and FIG. 6 (a) shows a state in which grooves of an angle θ are formed at equal intervals. (B) is an angle −
6 shows a state in which grooves of θ are formed at equal intervals to form a tape sliding surface, and FIG. 6 (c) shows a state in which the core block of FIG. 6 (b) is cut.

FIG. 7 is an explanatory diagram showing the operation of the magnetic head of FIG.

FIG. 8 is a perspective view showing a magnetic head according to a conventional example.

[Explanation of symbols]

 1, 2 core halves 3 Tape sliding surface 4 Gap spacer film 13, 23 Tip part 30, 31 Tip surface G Gap L Width per tape

Claims (1)

[Claims] 1. A first core half body, a second core half body attached to face the first core half body, and between tip portions of the first and second core half bodies. A magnetic head comprising: a gap formed; and a substantially arcuate tape sliding surface formed on the tip surfaces of the first and second core halves with the gap interposed therebetween. The tape contact width of the magnetic head is set to change in proportion to the degree of wear of the first and second core halves.