JPH01248304A - Magnetic head - Google Patents

Abstract

PURPOSE:To prevent the partial abrasion of a tape contact plane from being generated and to prevent a recording and a reproducing characteristics from being lowered by providing a material object formed by a magnetic with an m.p. and hardness higher than that of a soft member in the soft material of the tape contact plane. CONSTITUTION:Sub cores 11a and 11b are butted so as to form a magnetic gap 13 between main cores 12a and 12b, and glass parts 14 to stick the sub cores 11a and 11b are formed at both sides of the magnetic gap 13. And an almost ball shape particle 14a of alumina having a diameter of around 5mum is mixed in the glass parts 14, and the alumina particle 14a mixed in a tape feed plane is exposed. Thus, since the alumina particle that is the material with the m.p. and the hardness higher than that of glass is mixed in the tape contact plane, it is possible to prevent the partial abrasion of the tape contact plane from being generated, and to prevent the recording and the reproducing characteristics from being lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a magnetic head for recording and reproducing data on a magnetic tape.

(Prior Art) As the density of magnetic recording increases, metal tapes are used as recording media, and magnetic heads compatible with these metal tapes have been developed and are becoming popular.

A magnetic head compatible with metal tape has a sub-core 1a%' made of ferrite, as shown in FIG.
1b, a main core 2a s2b is formed using a vacuum thin film technique using a metal magnetic material such as sendust, and the main core 2a is formed so that a magnetic gap 3 is formed.
A and 2b are butted and joined by glasses 4a and 4b, and a coil 6 is wound around a through hole 5 penetrating the subcore 1a%1b. A magnetic head configured in this manner is called a so-called metal-in-gap head.

Next, a method of manufacturing the above magnetic head will be explained.

FIG. 5 is a diagram for explaining the manufacturing process of the magnetic head.

As shown in the figure, a pair of sub-cores (ferrite) la and l are formed with a main core (not shown) of a metal magnetic film.
b are butted against each other and pressurized, and in this state, the adhesive glass 4 is installed and heated. This causes the glass 4 to melt and form the sub-core la.

1b is bonded, and then cut and polished to obtain the final head shape.

Note that glass is often used to bond the subcore 1a and the subcore 1b from the viewpoint of reliability, and the range of material selection is limited due to the physical and Japanese properties of ferrite and metal magnetic materials. The bonding temperature needs to be about 600°C, and glass with a relatively low melting point, such as lead-based glass, is used.

Incidentally, in recent years, with the increasing density of recording on recording media, attempts are being made to increase the running speed of the tape. In this case, uneven wear occurs in the above-mentioned crow portion. As a result, it becomes difficult to obtain the desired contact between the gap portion and the magnetic tape, and there is a possibility that the recording and reproducing characteristics may deteriorate.

(Problem to be solved by the invention) As mentioned above, in conventional magnetic heads, when the running speed of the magnetic tape is increased in order to increase the recording density, uneven wear occurs on the crow part that adheres a pair of sub-cores. As a result, there was a problem in that the recording and reproducing characteristics deteriorated.

This invention is intended to solve the above-mentioned problem, and when the running speed of the magnetic tape is increased to increase the recording density on the magnetic tape, it is possible to prevent uneven wear on the tape contact surface. An object of the present invention is to provide a magnetic head that can prevent deterioration of reproduction characteristics.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a magnetic head in which a member softer than the core portion is present on a surface in contact with a magnetic tape, in which a member having a higher melting point and a higher melting point than the core portion is present in the soft member. A tangible object made of a highly hard material exists.

The above-mentioned core portion is made of a hard material such as ferrite or sendust, and the above-mentioned soft member is made of a material such as glass. In addition, the tangible objects present in glass, which is a soft material, are spherical particles with a diameter of about 5 μm.
Alumina, quartz glass, etc. are used.

(Function) In this invention, a tangible object formed of a material having a higher melting point and higher hardness than the soft member is present in the soft member on the tape contact surface, so that when the running speed of the tape is increased. However, uneven wear on the tape contact surface can be prevented during recording and playback.

It is possible to prevent a decline in sexual performance.

(Example) Hereinafter, an example of the present invention will be described in detail using the drawings.

FIG. 1 is a perspective view for explaining one embodiment of the present invention;
FIG. 2 is an enlarged view of the main part of FIG. 1.

In these figures, lla and llb indicate a pair of subcores made of ferrite, for example. Main cores 12a, 12b are formed on the sub-cores lla, ], ], b using vacuum thin film technology using a metal magnetic material such as sendust. subcore lla,
Four of the main cores 1.2a, ]-2b are butted together to form a magnetic gap [3], and on both sides of the magnetic gap 13, there are sub-cores 1], a,
A glass part] 4 to which the llb is bonded is formed. Note that 15 is Zabucoa l]a, ]1. A through-hole passing through b,] 6 indicates a coil wound around the through-hole ] 5.

The glass portion 14 described above is made of, for example, lead-based glass (Pb
70%) mixed with substantially spherical alumina particles 14a having a diameter of about 5 μm.

In the method for manufacturing the material of the glass portion 14 described above, lead-based glass is finely crushed in a mortar and then mixed with alumina particles 14a. The volume ratio of these is about 3:1 to glass alumina. After melting these in a crucible, they were solidified and cut into a predetermined size. This cut material was placed at a predetermined position between the sub-cores 11a and llb, and bonded by a normal bonding process (held at 530° C. for 130 minutes). After this, the bonded sample was processed into a head shape.

FIG. 2 shows a portion of the head near the gap.

As shown in the figure, the glass portion on the tape running surface]
4 refers to the mixed alumina particles 14a. Its area is about 1/4 of the glass portion.

When this magnetic head was allowed to wait for 30 hours at a tape speed of 20 m/s and a tape contact pressure of 3 ounces, the average amount of wear was improved to 1 μm, which was about 1/3 that of the conventional head.

FIG. 3 shows the types and amounts of particles 14a mixed into the glass portion 14, and the average wear amount of the material.

Note that even when the particles mixed in the glass portion 14 are changed from alumina to quartz glass, the amount of wear is improved compared to the conventional case. Note that the amount of wear was determined by using a stylus step needle, and the unevenness of the glass portion was averaged to obtain the average amount of wear.

Therefore, in the magnetic head of this embodiment, alumina particles, which are a material with a higher melting point and higher hardness than the glass part 14, are mixed in the glass part 14 on the tape contact surface, so that when the tape running speed is increased, However, uneven wear on the tape contact surface can be prevented. Therefore, it is possible to prevent the recording and reproducing characteristics of the magnetic head from deteriorating.

[Structure of the Invention] As explained above, in the magnetic head of the present invention, a tangible object made of a material having a higher melting point and higher hardness than the soft member is present in the soft member on the tape contact surface. Even when the running speed of the tape is increased, it is possible to prevent uneven wear of the tape contact surface, thereby preventing deterioration of recording and reproducing characteristics.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a magnetic head according to an embodiment of the present invention, FIG. 2 is an enlarged view of the main part of FIG. 1, and FIG. 3 shows contaminants in the magnetic head of FIG. A diagram showing the relationship between tape running surface exposure rate and average wear amount, FIG. 4 is a perspective view showing a conventional magnetic head, and FIG. 5 is a diagram for explaining the manufacturing process of the magnetic head shown in FIG. . 11a, 1lb--sub core, 12a, ], 2b--main core, 13...magnetic gap, 14 - glass part, 14a - alumina particles. Applicant Toshiba Corporation Patent Attorney Sasa Suyama - Figure 4 Figure 3 Figure 5

Claims (1)

[Claims] (1) In a magnetic head in which a member softer than the core portion is present on the surface in contact with the magnetic tape, a tangible object made of a material having a higher melting point and higher hardness than the core member is present in the soft member. A magnetic head featuring: