JPS60258711A - Vertical magnetic recording and reproducing head - Google Patents

Abstract

PURPOSE:To improve both reproducing sensitivity and high density recording performance by forming a ring core from a bulk magnetic substance having a permeability smaller than that of the magnetic thin film or from the bulk magnetic substance having a saturated magnetic flux density smaller than that of the magnetic thin film. CONSTITUTION:The ring core 10 is formed by the bulk magnetic substance, which is made of a magnetic material having a permeability smaller than that of the magnetic thin film 12 or a magnetic material having a staturated magnetic flux density smaller than that of the magnetic thin film 12. Thus, the magnetic thin film acts like a single magnetic pole heat at recording under single head structure and high density recording is applied, and since the entire ring core acts like a ring form magnetic path at reproduction, the magnetic resistance of the ring form magnetic path is reduced and the reproduction sensitivity is improved.

Description

[Detailed description of the invention] Technical field of invention The present invention relates to a direct magnetic recording/reproducing head.

Technical background of the invention and its problems: In general, head designs of this type include a magnetic pole head and a link type head9.The characteristics of both in perpendicular magnetic recording and reproduction are that the ring type head has The other is superior in playback performance, but inferior in high-density recording performance.
The head is the opposite. In other words, in a ring-shaped head that structurally has a large horizontal component in the recording magnetic field, the magnetization is vectorial, making it difficult to achieve ideal vertical magnetization.However, since it has a closed magnetic circuit configuration, the sensitivity during playback is In this respect, it has higher sensitivity than a single magnetic pole head.

For this reason, conventionally, as shown in FIG. 11, recording is performed on a recording medium 2 using a single magnetic pole head, for example, a main magnetic pole excitation type recording sheet 1, and a ring-shaped eight ( -3.However, such a head method is not suitable for both heads 1 and 3.
Practical implementation is difficult due to problems such as azimuth and other alignment accuracy.

Therefore, a single head structure capable of recording using a single magnetic pole head method and reproducing using a single ring type head has been proposed in Japanese Patent Application No. 33862/1982. The principle of such a device will be explained based on FIG. 12. A ring-shaped ring core 10 is provided, and two magnetic thin films 12 are provided on this link core 10 with a gap 11 between the ring core 10 interposed therebetween. The ring core 10 consists of a slider 13 made of a non-magnetic material that holds the tip of the magnetic thin film 12, and a core part 14 made of a magnetic material connected to the stripe 1', and together with the magnetic thin film 12 forms a ring-shaped magnetic path. 15 is formed. A reproduction winding 17 is wound around the two leg portions 16a and 16b of the ring core 10, and a recording winding 18 is wound around the outer periphery of the ring core 10. Note that the magnetic thin film 1
Recording media 19 are arranged facing each other at the two leading ends.

With such a structure, when a recording signal is applied to the recording winding 18, a magnetic flux is generated in the vertical direction from the magnetic recording film 12, and recording can be performed in the same manner as in a normal magnetic pole head system. On the other hand, during reproduction, the gap 11 acts as a gap portion of a normal ring-shaped head, making it possible to perform reproduction using a link-type head. In this way, with a single head structure, it is possible to perform single-pole/rad type recording and link type/one-way type reproduction. However, the J width of the magnetic thin film 12 must be thin for perpendicular recording, but in this case, the magnetic resistance of the magnetic thin film 12, which acts as part of the link magnetic path 15 during reproduction, becomes large. Put it away. This has the disadvantage that reproduction sensitivity deteriorates.

Purpose of the Invention The present invention has been made in view of the above points, and an object thereof is to obtain a perpendicular magnetic recording/reproducing head having a single head structure that is excellent in both reproduction sensitivity and high-density recording performance. Summary of the Invention The present invention provides a ring core having two opposing magnetic thin films in a gap formed from a bulk magnetic material having a smaller magnetic permeability than the magnetic thin films or a bulk magnetic material having a saturation magnetic flux density smaller than the magnetic thin films. , the high-density recording characteristics due to perpendicular magnetization enable excellent recording, and the entire ring core acts as a ring-shaped magnetic path during playback, so the magnetic resistance in the ring-shaped magnetic path is reduced and playback sensitivity is improved. ; It is configured to do so.

Embodiment of the Invention A first embodiment of the invention will be described with reference to FIGS. 1 to 7. Note that the same or corresponding parts as in FIG. 12 are indicated by the same reference numerals, and explanations thereof will be omitted.

First, Figure 1 shows the basic configuration, and shows the ring core lO
is made of bulk magnetic material.

This magnetic body is made of a magnetic material having a lower magnetic permeability than the magnetic thin films 12 or a magnetic material having a lower saturation magnetic flux density than the magnetic thin films 12.

Next, a more specific structure will be explained based on FIGS. 2 to 5. The link core 1o is a ring core loa, fob (-divided) made of ferrite.
The facing surface 2o facing the vocabulary recording medium 19 is a smooth surface having a predetermined area. The 1i1&+'l thin film 12 is the ring core 1.
It was formed between o・a T I 013. W film with magnetic permeability and saturation magnetic flux density of Co - Z r - N b
The thickness is about 0.5 to 5 μrn. Moreover, the cap 11 between these magnetic thin films 12
7. r It is a thin film made of non-magnetic material such as O2 or SiO2, and the thickness is about 0.1 to 0.5 μm. and the link core], Oa.

A glass plate 21 that defines the track width of the magnetic thin film 12 to a width T is fitted on both sides between lOb. Furthermore,
Said ring core] There is a hole 2 in the middle part between Oa and the fob.
2 is provided, and the leg portion 1 is divided into two parts by this hole 22.
6a and 16b are formed. In addition, these legs 1
The reproducing winding 17 wound around the legs 6a and 16b is equally wound around both the legs 16a and 16b.In such a configuration, when a recording signal is applied to the recording winding 18, , a magnetic flux is generated in the perpendicular direction from the magnetic thin film 12, and perpendicular magnetic recording is performed on the recording medium 19. The magnetic flux distribution at this time is shown in FIG. According to this, the advancing recording medium 19
Recording is performed by the magnetic flux at point A, which is the position of the magnetic thin film 12 where the recording medium 19 last passes (the traveling direction of the recording medium 19 is indicated by an arrow in FIG. 6). Also, when recording, ring core 10
Magnetic flux is also generated from the magnetic thin film 12, but this magnetic flux is
1: It is weaker than the magnetic flux generated by the magnetic flux, and does not affect the recording medium 19. These reasons will be explained based on graph 1 in FIG. Assuming that recording is performed on the recording medium 19 with a coercive force He = 4000e and a saturation magnetic flux density Bs = 6KG, the recording point P (t-1 =
The equivalent relative permeability 11s at 680 0 c, B = 6 K G ) is.

It is. As a result, the effective magnetic permeability μe of the recording medium 19 becomes μe2μs+μo′=10 (μ0 is the magnetic permeability of vacuum). For example, if recording is to be performed using a magnetic field that produces a magnetic flux of 2 r < cr, the magnetic field Hf between the ring core 10 made of ferrite with μ=800 and the recording medium 19 will be μe. Also, the magnetic flux from the magnetic thin film 12 with μ=4000 is 2KGX5] OK c, but because it is diffused, it becomes about 2/3 at the recording position entry point of the magnetic thin film 12,
It is 6.7KG. As a result, the magnetic field Hw with respect to the recording medium 19 becomes 6.7 KQ 4~v = = 670 0e μe. In this way, the magnetic thin film 12 generates a magnetic field of 6700 (!) compared to the ring core IO which generates a magnetic field of only 2000 e against the recording medium 19. Therefore, considering that the coercive force is 4000 e 2,
Recording is performed only by the magnetic flux from the magnetic thin film 12. Note that although the ring core 10 with a small magnetic permeability has been described below, the same effect can be obtained even if a ring core 10 with a small saturation magnetic flux density is used.

On the other hand, during playback, the gap 11 is changed to the normal link type hex 1.
1, that is, the magnetic flux excited from the recording medium 19 to the gap 11 passes through the ring-shaped magnetic path 15 to the reproducing winding 17 for detection and reproduction. playback. At this time, the entire ring core 10 made of bulk magnetic material acts as the ring-shaped magnetic path 15, so the link-shaped magnetic 1
15 magnetic field 11 (resistance is reduced and reproduction sensitivity is improved. Also, since the reproduction winding 17 is evenly wound around both legs 16a and 16b, there is little induction by external magnetic fields. The induced voltage for the magnetic flux at both legs 16a,
This regeneration winding 1 is offset by the regeneration winding 17 of 16b.
It also has the effect of preventing generation of a large voltage in the output of the entire 7. Furthermore, as a result of this improvement in reproduction sensitivity, it is no longer necessary to use a two-layer medium with a high magnetic permeability layer such as permalloy added to the recording medium 19, and an inexpensive single-layer recording medium 19 can be used. Become. By the way, conventionally, when performing high-density recording (short wavelength recording) with a magnetic pole head, it is necessary to make the main magnetic pole thickness sufficiently thin, for example, about 0.2μI11. The overlapping characteristic of the recording medium, that is, the ability to erase the previously recorded signal and rewrite it with a new one, deteriorates, and the reproduction output also decreases. In this regard, according to the method of this embodiment, by reducing the gap 11 to 4 minutes, for example, 0.2 μI11 or less, it is possible to sufficiently reproduce short wavelength recording, and at the same time, during recording, the main magnetic pole thickness ( As a result, good overwriting characteristics can be obtained as a result of recording with the thickness of the magnetic thin film 12 (which is 1 to 10 μm for two sheets).

Furthermore, in manufacturing the head, the magnetic thin film 12 can be formed on the ring core 10, which is a bulk magnetic +1 body, by thin film technology, so manufacturing is simple and highly accurate.

A second embodiment of the present invention will be described based on FIGS. 8 to 10. In this embodiment, the outer circumferential core 23 that forms the return magnetic path is fixed to the ring core 10, the recording winding 18 and the reproducing winding 17 are eliminated, and the windings 24a and 24b are equally distributed on both legs IGa and 16b. It is rolled. These windings 24a and 24b are connected in series, and the polarity of one of the windings 24b can be freely reversed by a changeover switch 25, and is connected in series with the other winding 24a. In addition, in the figure, 26 is a base made of a non-magnetic material.

In such a configuration, the outer core 23 acts as a return magnetic path, improving sensitivity during recording. Further, during recording, the changeover switch 25 is switched to the W side. As a result, the recording current flowing through both windings 24a and 24b creates a magnetic thin film.]
In No. 2, a magnetic field is generated in the same direction toward the recording medium 19, and recording is performed using a single magnetic pole head method.

On the other hand, during reproduction, the selector switch 25 is switched to the 1< side, and the polarity of the winding 24b is reversed. As a result, the induced voltage due to the reproduction magnetic flux generated in the link type magnetic path 15 based on the gap 11 is applied to the winding 24a.

24b, a ring head type regeneration is performed.

That is, in this embodiment, the windings 24a and 24b serve both as a recording winding and a reproducing winding.

As described above, according to these embodiments (b), during recording, it operates as a main pole excitation type spatula 1 with a large perpendicular magnetic field component, so that ideal high-density perpendicular magnetic recording is possible. On the other hand, during playback, the sensitivity is several times higher than link type/RAD playback, and it is resistant to induced noise, amplifier noise, etc.
Playback with good S/N is the most important factor. Further, in this case, since the entire link core 10 acts as the link type magnet M15, the magnetic resistance of the ring type magnetic path 15 is reduced, and the reproduction sensitivity is significantly improved.

Effects of the Invention Since the present invention is configured as described above, it is possible to perform high-density recording under a single rad structure by causing the magnetic thin film to act as a single magnetic pole head during recording, and
During playback, the link-shaped magnetic path including the gap acts as a ring-shaped head for high-sensitivity playback.In this case, the entire link core acts as the ring-shaped magnetic path, so the magnetic resistance of the link-shaped magnetic path is reduced. In addition, if the reproducing winding is wound almost equally on both legs of the link type magnetic path, the induction by external magnetic field can be reduced, and the reproducing winding A large voltage will not be generated in the output of the wire, and the polarity of one of the windings wound almost equally around both legs of the link type magnetic path can be reversed and connected in series with the other winding. This provides effects such as the ability to simplify the recording winding by also using it as the reproducing winding. 3

[Brief explanation of the drawing]

Figure 1 is a principle diagram of the first embodiment of the present invention, and the second
The figure is a plan view showing the specific structure, Figure 3 is a side view partially taken along the line xx' in Figure 2, and Figure 4 is the Y in Figure 2.
5 is a vertical side view showing an enlarged cross-sectional area of FIG. 3, FIG. 6 is a vertical side view showing the recording operation, and FIG. 7 is a diagram showing magnetic characteristics. Fig. 8 is a plan view showing a second embodiment of the present invention, Fig. 9 is a side view thereof, Fig. 10 is a front view [21, Fig. 11 is a side view showing a conventional example, and Fig. 12 is a separate It is a side view showing an example. . 10・Link core, 11・Gap, 12 Magnetic thin film, 16・Legs, 17・II! -Cow winding, 18...
Recording winding, 19...Recording medium, 24.Winding Applicant: Tokyo Electric Co., Ltd. 11 Ko0 Meeting

Claims (1)

[Claims] 1. Two magnetic thin films facing each other with a gap are provided at the tip facing the recording medium, and a ring core holding these magnetic thin films is made of a bulk material having a lower magnetic permeability than the magnetic thin films. A recording winding formed of a magnetic material or a bulk magnetic material having a saturation magnetic flux density smaller than that of the magnetic Av film, and generating a magnetic field in the same direction from the tip of the magnetic thin film toward the recording medium; A perpendicular magnetic recording/reproducing head, characterized in that the ring core is provided with a reproducing winding for detecting magnetic flux excited from a medium to the cap. 2. The perpendicular magnetic recording/reproducing head according to claim 1, wherein the recording winding is wound around the entire outer periphery of the ring core, and the reproducing winding is wound around the leg portion through the hole portion of the ring core. . 3. Pass the winding through the hole in the ring core and wind it approximately evenly around both legs.The polarity of one of the windings can be reversed and connected in series with the other winding, and both of these windings are used for recording. 1. A perpendicular magnetic recording/reproducing head according to claim 1, characterized in that the head is used both as a winding and as a reproducing winding. 4.11 Perpendicular magnetic recording/reproducing spatula 1-1° according to claim 2, characterized in that raw windings are wound almost equally around both legs.