JPS62141612A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain a magnetic head which has good wear resistance and is strong to thermal change by constituting a shielding material of ceramics, ferrite, and ceramics in this order into a sandwich state and uniting the laminate into one body by glass welding. CONSTITUTION:Ferrite cores 10, 10' adhered by glass 11 are provided with shielding grooves 14, 15, 16. A nonmagnetic sheet 17, ferrite sheet 18 and nonmagnetic sheet 17' are formed in such a manner that the total laminated thickness is smaller by about 0.02-0.2mm than the width (m) of the working grooves. The nonmagnetic sheets 17, 17' for shielding to contact the traveling surface of a magnetic tape and the ferrite sheet 18 are formed wider by at least 1mm or above than the ferrite cores 10, 10' forming the track. The respective parts are fixed by jigs and bonding glass is placed thereon, then the parts are subjected to a heat treatment in an electric furnace in which a reduced atmosphere is maintained in the case of a core 1 consisting of Mn-Zn ferrite. The bonding glass is thereby melted and the laminate is fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a multi-track magnetic recording/reproducing head.

Conventional Technology In magnetic recording technology for audio, a stereo magnetic recording and playback method has traditionally been used to create a sense of presence and impact. In addition, recording and reproduction may be performed not only with two tracks, but also with a multi-element magnetic head having two or more tracks.

In such magnetic recording technology, if there is magnetic flux leakage from adjacent tracks, analog signals will interfere with each other when reproduced, making the separation between the two tracks unclear, and digital signals may cause reading errors. It will be connected.

In order to remove magnetic flux leakage from adjacent tracks, magnetic heads that generally use metallic magnetic materials,
Cores 2, 2 surrounded by case l as shown in Figure 6
A magnetic shield plate 3 wider than the width of ) is inserted between the tracks, and the r-space 11. ! : A filling material 4 made of synthetic resin is inserted between the holes to reduce and eliminate leakage magnetic flux. Therefore, conventionally, as shown in Fig. 7, the shielding material for the ferrite magnetic herad core 6.6゛ was
The non-magnetic plate 7.7' and the magnetic plate 8 are respectively replaced by the non-magnetic plate 7,
A magnetic plate 8 and a non-magnetic plate 7' were laminated in the order of Sand German f-shape and were inserted between cores 6.6' to be integrated. Furthermore, in order to improve shielding efficiency and absorb leakage magnetic flux, a metal magnetic material such as permalloy has been used as the magnetic plate 8. At this time, the shield material used was a non-magnetic material such as a metal material such as a copper plate or a German silver plate, or ceramics.

Problems to be Solved by the Invention However, in order to integrate the shield material and the core, it is necessary to use ferrite, which is an oxide ceramic, and a metal material, which have completely different physical and mechanical properties. There was no way to glue it with resin. As a result, changes in environmental conditions caused the resin to protrude from the core due to heat generated during tape running, and magnetic powder from the tape mixed into the resin, resulting in damage to the tape.

Means for Solving the Problems Therefore, the present invention uses ceramics and ferrite as the shielding material for the ferrite magnetic head.Therefore, it is an object of the present invention to obtain a magnetic head that has good wear resistance and is resistant to thermal changes. was completed.

Example The present invention will be specifically described below.

FIG. 1 shows an embodiment of the magnetic head of the present invention.
This is a stereo magnetic head using a metal magnetic material such as permalloy, which is commonly used in tape recorders.

Reference numeral 10.10' denotes a core formed by molding a ferrite material, and magnetic gap portions 12.12'' and 12'' are made of glass 11 to predetermined dimensions. Further, reference numerals 13 and 13' denote pressing members made of ceramic, and are formed in a comb-teeth shape so as to face each other. The ferrite core 10.10' bonded by the glass 11 is connected to the shield groove 14.1.
5.16 is provided. Furthermore, the pressing member 13.
13' also has grooves 14°, 14'', 15', 15'', respectively.
, 16', 1G- are provided, and each groove is 1
This is the positional relationship corresponding to 4.15.16. Further, the width m of the machined groove at each time is determined by the track dimensions e and n and the track pitch e0m or m + nl. Reference numerals 17 and 17' are non-magnetic plates made of ceramic, and 18 is a processed or heat-treated ferrite plate, which is made of the same material as the ferrite cores 10 and 10'.

These non-magnetic plates 17. Ferrite plate 18. Non-magnetic plate 17
The total thickness of laminated ゛ is 0.02~ than the width m of the processed groove.
It is formed to be about 0.2 mm thinner. FIG. 2 is a top view of a magnetic head according to an embodiment of the present invention, and FIG. 5 is a front view of the same. In FIG. 3, the cut surface, that is, surface A in FIG. 4, is processed into a mirror surface, and after machining the ferrite 21 glass-bonded to the ceramic plate 2o, eight surfaces are mirror-finished. Insert the coil 22 there. FIG. 5 shows a closed magnetic circuit including the back shield plate 19.

Non-magnetic plate 17 for shielding that contacts the magnetic tape running surface
．． 17° and the ferrite plate 18 is at least IM relative to the ferrite core 10.10' forming the track.
In addition, the holding member 13.13' has grooves 14' and 15' at positions corresponding to the shield plate insertion portions 14° and 15.16 of the core 10.10'.
.

16" and grooves 14", 15", and 16" with diamond
It is provided by machining with a saw. The depth P of the groove at this time is determined by the following formula.

P=(N-M)/2+α N≧M+1 Also, α is +
A value of about 0.05 to +0.2 is appropriate, and a larger value may be used, but if the value is too large, bubbles may be generated when bonding is finally performed with glass.

Next, each part is fixed with a jig, bonding glass is placed on top of it, and if the core 1 is Mn-Zn ferrite, it is heat-treated in an electric furnace in a reduced atmosphere with the required temperature gradient. By doing so, the bonding glass is melted and fixed.

Here, we must be especially careful that the bonding glass at this time has a magnetic gap of 12°12', 12''.
, 12''', the difference in thermal expansion coefficient from that of the glass 11 must be within 5%, and the working temperature difference in the electric furnace must be at least 50°C. When there is not much difference in temperature, the magnetic gap 12.12', 12'' is the most important for the characteristics of the magnetic head.
.

This is because there is a possibility of changing the width of the core 10.
The difference in expansion coefficient between the three must be within ±5%.
When taken out of the electric furnace, cracks appear and the product becomes unusable.

FIG. 2 shows a state in which glass is bonded, and the non-magnetic plate 17
．． The width N of the shield block 7 made up of the shield block 17' and the ferrite plate 18 is increased, and moreover, it is fixed by glass.

Figure 3 shows this as seen from the side, and since each part is fixed to the glass, it can be fixed to a cutting jig and cut with a diamond saw. The processed surface, that is, surface A, is processed into a mirror surface using abrasive grains such as diamond, and a non-magnetic plate 20 made of ceramic is glass-bonded to a core block 21 made of the same material as the core 10.10'. Using a diamond saw, cut a groove in the direction of arrow C to a predetermined size to form a closed magnetic path with the cores 10 and 10°.Next, cut a groove in the direction of the arrow. Cut to the desired position and separate each track.

Then, the coil 22 is inserted after mirror-finishing the eight surfaces between the A surfaces using abrasive grains such as diamond.

Next, the back shield plate 19 is fixed with resin or the like in a manner corresponding to the ferrite plate 18 of the shield block consisting of the non-magnetic plates 17, 17'' and the ferrite plate 18, and then the coil part is further glued in a predetermined position. The width R of the back shield plate 19 at this time is also the same as that of the non-magnetic plate 1.
7.17' and the width N of the shield block made of the ferrite plate 18, and also needs to be wider than the width of the coil 22. Also, the materials of one back shield plate are non-magnetic plate 17, 17' and ferrite plate 18.
Although it may be made of the same material as the magnetic material 18 of the shield block 7 made of Further, as described above, the present invention provides a shield block in which a ferrite plate is sandwiched between two ceramic plates between each multi-track head core. Because it is inserted, it is possible to effectively provide magnetic shielding between each head core, and because it has high heat resistance, it can be bonded with glass, which prevents inconveniences caused by heat generated by friction with recording media such as tape. Never.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing one embodiment of the magnetic head of the present invention, FIG. 2 is a top view of the same, FIG. 3 is a side view of the same manufacturing process, and FIG. 4 is an exploded perspective view of the same manufacturing process. FIG. 5 is a side view of the same, and FIGS. 6 and 7 are top views of a conventional magnetic head.

Claims (1)

[Claims] It consists of a plurality of cores each having a magnetic gap corresponding to a plurality of tracks, two plates made of non-magnetic material inserted between each of the cores, and a plate of magnetic material sandwiched between them. a shield member that is longer than the width thereof, and the two plates made of non-magnetic material and the magnetic plate are adhered to each other with glass, and the space between the two plates made of non-magnetic material and each of the cores is made of glass. A magnetic head characterized by adhesive.