JPS62219213A - Composite magnetic head - Google Patents

Abstract

PURPOSE:To shorten a gap space and to correspondingly improve the recording density by using a thin magnetic film to form at least either the core half body on the recording/reproducing head side of an erasing head or core half body of erasing head side of the recording/reproducing head. CONSTITUTION:The 1st core half bodies 5, 11 are formed of a magnetic material such as, for example, ferrite and the 2nd core half bodies 6, 12 are formed of a crystalline alloy or amorphous alloy having a high satd. magnetic flux density and high magnetic permeability. The crystalline alloy to be applied to the 2nd core half bodies 6, 12 includes an iron-aluminum-silicon alloy, etc. The thickness (t) of the 2nd core half bodies 6, 12 is more preferable as said thickness is smaller within the range where the magnetic flux is not satd. Said core half bodies are formed approximately to the thickness equal to the gap depths d1, d2 (about 10-30mum) of the erasing head 1 and the recording and reproducing head 2.

Description

[Detailed Description of the Invention] [Industrial Application] The present invention relates to a composite magnetic head in which an erasing head and a recording/reproducing head are integrally connected. Placed. The present invention relates to an erase head-advanced composite magnetic head.

[Conventional technology]

In recent years, in magnetic recording media drive devices such as video tape recorders and magnetic disk drives.

Increasing the recording density has become one of the most important technical issues, and in order to meet this demand, there is a trend toward the use of magnetic recording media with high coercive force or with perpendicularly magnetized films. be. However, magnetic recording media with high coercive force or magnetic recording media made of perpendicularly magnetized films have poor override characteristics, so for example, tunnel-type composite magnetic heads do not allow new signals to be overwritten (overwritten) on top of previously recorded tracks. ) type of magnetic head cannot perform erasing and rewriting with excellent reliability.

In order to erase N interlayer points between the magnetic heads of the above method, as shown in FIGS. 3 and 4, the erasing head 21 is placed on the upstream side X in the running direction of the magnetic recording medium, and the erasing head 21 is placed on the downstream side Y in the running direction of the magnetic recording medium. An erase head-first composite magnetic head in which a recording/reproducing head 22 is arranged has been proposed.

The erasing head 21 includes a first core half 24 made of, for example, ferrite, which is formed by machining, such as cutting, a coil groove 23, and a first core half made of, for example, ferrite, arranged to face the first core half 24. A gap spacer 26 made of silicon dioxide, for example, interposed between the second core half 25 and both core halves 24 and 25,
A reinforcing portion 27 made of glass or the like is provided near the joint between the 4° 25 and the gap spacer 26, and an excitation coil 28 is wound on the coil groove 23 of the first core half 24.
It is formed from.

On the other hand, the recording/reproducing head 22 includes a first core half 30 made of, for example, ferrite, in which the coil groove 29 is formed by machining such as cutting, and a first core half 30 made of, for example, ferrite, which is arranged to oppose the first core half 30. a second core half 31, a gap spacer 32 made of silicon dioxide, for example, interposed between the two core halves 30.31, and a gap spacer 32 provided near the joint between the two core halves 30.31 and the gap spacer 32. A reinforcing portion 33 made of, for example, glass.

and an excitation coil 34 wound on the coil groove 29 of the first core half 30.The erasing head 21
And what is the recording/reproducing head 22?

In order to avoid each other's magnetic shadows 9#, the erase head 21 is connected integrally through a non-magnetic plate 35, and the erase head 21 is directed toward the upstream side in the running direction of the magnetic recording medium in a head holding section of a magnetic recording medium drive device. will be placed.

The above-mentioned erase head-advanced composite magnetic head erases the previously recorded track with the erase head 21 and then rewrites the signal, so it can perform highly reliable erasing and rewriting even on magnetic recording media with poor override characteristics. Records can be made.

[Problems that the invention attempts to solve]

By the way, in the above-mentioned erasing head-first type composite magnetic head, a recording loss occurs by the distance (gap interval) L between the gap spacer 26 of the erasing head 21 and the gap spacer 32 of the recording/reproducing head 22. That is, as shown in FIG. 5, when using this composite magnetic head to write a signal to a magnetic recording medium 37 on which a sector signal 36 such as address information is recorded in advance at the beginning of each sector, the recording/reproducing head 22 When you have finished reading sector signal 3G,
The gap spacer 26 of the erase/1 field 21 is in advance on the magnetic recording medium 37 by the above-mentioned gap distance, and even if the erase head 21 is activated when the recording/reproducing head 22 has finished reading the sector signal 36, the corresponding Erase start section 37
No signal can be recorded until a reaches the gap spacer 32 of the recording/reproducing head 22, and a recording loss corresponding to the gap interval occurs.

Therefore, in order to realize high-density recording, the gap interval 1. It is necessary to make it as small as possible.

However, in the conventionally proposed erase head type composite magnetic head, the first core half 24+3o
In order to enable the required machining to be carried out after joining the second core half 25.31, the erasing head 2
The thickness of the second core half 25 disposed on the one recording/reproducing head 22 side and the second core half 31 disposed on the erasing head 21 side of the recording/reproducing head 22 is set to at least 0.5 mm.
The thickness of the non-magnetic plate 35 for connecting the erasing head 21 and the recording/reproducing head 22 must be 2 mm or more, and it is difficult to reduce the thickness to 0.1 nm or less due to processing reasons. Therefore, in this composite magnetic I\rad, at least 0
．． If a gap interval of 5 mm or more is formed and the wavelength of the recording signal is 2 μm, a recording loss of approximately 30 bytes will occur.

[Means for solving problems]

Does the present invention reduce the magnetic gap distance? 2nd record high dividend @
In order to achieve higher density, at least one of the core half on the recording/reproducing head side of the erasing head and the core half on the erasing node/recording/reproducing head is made of a magnetic material having a high saturation magnetic flux density. It is characterized by being constructed from a magnetic thin film consisting of.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 and 2.

Figure 1 is a plan view of the composite magnetic head, and Figure 2 is A of Figure 1.
-A sectional view, 1 is an erasing head, 2 is a recording/reproducing head, and 3 is a connecting member for connecting the erasing head 1 and the recording/reproducing head 2.

The erasing head 1 includes a first core half 5 made of ferrite, for example, with a coil groove 4 formed by machining such as cutting.
A second core half 6 made of a magnetic thin film is arranged to face the first core half 5, and a gap spacer made of silicon dioxide, for example, is interposed between the two core halves 5 and 6. 7 and 5 A non-magnetic reinforcing portion 8 made of, for example, glass is provided near the joint between the first core half 5 and the gap spacer 7, and a reinforcing portion 8 is wound on the coil groove 4 of the first core half 5. It is composed of an excitation coil 9 and an excitation coil 9.

On the other hand, the recording/reproducing head 2 includes a first core half 11 formed of a coil groove 10 by machining such as cutting, and a magnetic Second core half 12 consisting of y4M
A gap spacer 13 made of, for example, silicon dioxide is interposed between the first core half 11 and the gap spacer 13, and a non-gap spacer made of, for example, glass is provided near the joint between the first core half 11 and the gap spacer 13. It consists of a magnetic reinforcing part 14 and an excitation coil 15 wound on the coil groove lO of the first core half 1.

The first core half 5.11 is made of a magnetic material such as ferrite, and the second core half 6.11 is made of a magnetic material such as ferrite.
2 is formed of a crystalline alloy or an amorphous alloy having high saturation magnetic flux density and high magnetic permeability. Crystalline alloys applicable to the second core half 6.12 include iron-aluminum-silicon alloys, iron-silicon alloys, and iron-nickel alloys. On the other hand, as an amorphous alloy, an alloy consisting of one or more elements selected from the group of iron, nickel, and cobalt and one or more elements selected from the group of phosphorus, carbon, boron, and silicon;
Or aluminum, germanium, beryllium, tin with this as the main component.

Indium, molybdenum, tungsten, titanium.

There are alloys to which elements such as manganese, chromium, zirconium, hafnium, and niobium are added, and alloys containing cobalt and zirconium as main components and the above-mentioned additional elements. The thickness t of the second core half 6.12 is preferably as thin as possible as long as the magnetic flux is not saturated.
The thickness is approximately the same as the gap depths dl and dz of the recording/reproducing head 2 (approximately 10 μm to 30 μm).

The connecting member 3 has a length of at least 0.1 m to avoid magnetic influence between the erasing head 1 and the recording/reproducing head 2.
It is formed from a non-magnetic thin plate such as ceramic having a thickness of m or more.

Note that the track width a of the erasing head 1 (the width of the gap spacer 7) is formed wider than the track width b of the recording/reproducing head 2 (the width of the gap spacer 13), thereby reducing the off-track margin. It is now possible to obtain

Hereinafter, the manufacturing procedure of the above-mentioned composite magnetic head will be explained.

First, a second core half 6 made of magnetic RfBI is formed on one surface of the connecting member 3 using a thin film forming technique such as vapor deposition, sputtering, or ring fly, and a magnetic thin film is formed on the other surface of the connecting member 3. The second core half 12 is formed using the same thin film forming technique as described above.

Next, 1N thin film gap spacers 7 and 13 are formed on the surfaces of the second core halves 6 and 12 formed on both sides of the connecting member 3 by vapor deposition or sputtering.

The connecting member 3. is then connected as described above. Second core half 6
,12. and gap spacers 7113 are attached to the first core half 5 from both sides of a thin plate-shaped member.
, 11 are joined together, and finally, excitation coils 9 and 15 are wound around each coil groove 4 and 10, thereby constructing a composite magnetic head.

The composite magnetic head described above is a head of a magnetic recording medium drive device such that the erasing head L is disposed on the upstream side X in the running direction of the magnetic recording medium 1, for example, a magnetic disk, and the recording/reproducing head 2 is disposed on the downstream side Y thereof. It is incorporated into a holding member (not shown).

The composite magnetic head of the above embodiment has second core halves 6,1
2 are each formed to have a thickness of 10 μm to 30 μm, and the connecting member 3 is formed to have a thickness of approximately 0.1 mm.
The gap distance can be formed to be approximately 0.12 mm to 0.16 mm. Therefore.

When the wavelength of the recording signal is 2 μm, the recording loss can be suppressed to about 8 bytes to 10 bytes, which is about 1/4 to 1/4 of the recording loss compared to conventionally proposed composite magnetic heads.
/3.

It should be noted that the materials, numerical values, and shapes shown in the above examples indicate one example of the present invention, and it goes without saying that the gist of the present invention is not limited to these shapes, materials, and numerical values. It is.

〔Effect of the invention〕

As explained above, in the composite magnetic head of the present invention, at least one of the recording/reproducing head-side core half of the erasing head and the erasing head-side core half of the recording/reproducing head is magnetic. Since it is formed using W[, the gap distance can be shortened and the distribution zero density can be improved.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a plan view showing an embodiment of the magnetic head according to the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a conventional composite magnetic head. A plan view showing an example of the head, FIG. 4, a sectional view taken along line 13-B in FIG. 3, and FIG. 5 are explanatory diagrams illustrating problems with the conventional composite magnetic head. ! ... Recording/reproducing head, 2... Erasing head, 3... Connection member, 4... Coil groove,
5...First core half, 6...Second core half, 7...Gap spacer, 8...Reinforcement part, 9...・Exciting coil, 10... Coil groove, 11... First core half, 12...
...Second core half, 13...Gap spacer, 14...Reinforcement part, 15...Excitation core.
r, X...Upstream side in the running direction of the magnetic recording medium, Y...Downstream side in the running direction of the magnetic recording medium, L
・・・・・・Gap interval l° Toward extinction/de
5. Bubu: Total 1st core 5 i J 2, Enshun 1st main he) - (y, lri: Ma 2 - core ratio 3,
Phi, ♂t6J7X 7. t3:
Yamaku 7 Suhe 2 guns? 2nd X===shiY 7p Same 4th

Claims (1)

[Claims] In a composite magnetic head in which an erasing head disposed on the upstream side in the running direction of a magnetic recording medium and a recording/reproducing head disposed on the downstream side in the running direction are integrally connected, a core half on the recording/reproducing head side of the erasing head. and a composite magnetic head, wherein at least one of the core halves on the erasing head side of the recording/reproducing head is composed of a magnetic thin film made of a magnetic material having a high saturation magnetic flux density. .