JPS6231011A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain sufficient erasure characteristics with a small erasing current by forming an erasure gap which is formed of a recording/reproducting core and an erasure core by using >=2 flanks of the erasure core. CONSTITUTION:The erasure gap is formed by using plural flanks of the erasure core. Namely, the width of one recording/reproducing core 4A is 2F, but the right end part is ground by G on each of both side parts to obtain width C. The length of the notch of the width G is J and erasure cores 7 and 7 are arranged in the notchs at distance H from the recording/reproducing gap 3. The width of those erasure cores 7 and 7 is smaller than the width G and the erasure gap whose width is large in the running direction of a magnetic recording medium is formed between the erasure cores 7 and 7 and one recording/reproducing core 4A. Consequently, the entire erasure track is erased by the erasure gap, so sufficient erasure characteristics are obtained with a small erasing current even when magnetic recording media for high recording density which have high holding power are not used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head, and particularly to a magnetic head used in a floppy disk drive or the like.

[Conventional technology]

FIG. 8 is a perspective view showing an example of a conventional magnetic head.

The magnetic head shown in the figure is used as a magnetic head in, for example, a floppy disk device, and performs an erasing operation in addition to a recording/reproducing operation, and includes a recording/reproducing head 1 that performs a recording/reproducing operation, and an erasing head that performs an erasing operation. It is composed of 2.

The recording/reproducing head 1 has a pair of recording/reproducing cores 4A and 4B with a recording/reproducing gap 3 formed on the joint surface, and a recording/reproducing coil 5 is wound around the other recording/reproducing core 4B. Core 4A.

A magnetic circuit is formed by connecting a recording/reproducing baffle core to the lower end side surface of 4B.

The erasing head 2 has a pair of erasing cores 7.7 connected by a glass member 10, and a U-shaped erasing hole 8 is connected to the erasing cores to form a magnetic circuit. An erasing coil 9 is wound around.

FIG. 9 is an enlarged plan view of essential parts showing the end faces of the pair of recording/reproducing cores 4A, 4B and the erasing core 7.7, and shows the recording/reproducing gap 3 formed between the image recording/reproducing cores 4A, 4B.
An erasing core 7.7 is disposed near the recording/reproducing core 4A so as to face the side surface of one recording/reproducing core 4A. Recording/playback core 4A
, 4B is the erase gear C1, the width of the tabs 7, 7 is E, and the width of the erase gap 1) is D, then the distance B from the center to the outermost edge of the erase core 7 is 'AC+D+B. Further, the distances between the right end surface and left end surface of the erasing core 7 and the recording/reproducing gap 3 are J and H, respectively.

FIG. 10 shows an erase gap 1) formed between one recording/reproducing core 4A and an erase core 7.7. 1) is an enlarged plan view of the main part. The erasing action is obtained at the edge portion of the erasing core 7 as shown by diagonal lines.

Figure 1) shows an erase gap 1) formed between one recording/reproducing core 4A and the erase core 7.7. 1) is an enlarged cross-sectional view of a main part. The erasing gear knob depth is a distance A from the upper end surface of the erasing core 7 to the edge of the neck portion 13.

[Problem that the invention seeks to solve]

In conventional magnetic heads, erasing is performed at the edge of the erase core 7 in contact with the magnetic recording medium. A large erasing current is required to generate a more sufficient erasing magnetic field, which poses a problem in that the magnetic head can only be used in a limited range of applications.

Additionally, there is a problem in that the applications of storage devices using such magnetic heads are limited.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide a magnetic head that can obtain sufficient erasing characteristics with a small erasing current.

[Means for solving problems]

A magnetic head according to the present invention is a magnetic head of a type in which erasing cores are arranged on both sides of a recording/reproducing core for recording and reproducing signals to realize an erasing action, and the magnetic head is formed by the recording/reproducing core and the erasing core. The erase gap is formed using two or more sides of the erase core.

[Effect]

In the magnetic head of the present invention, is the erasing gear knob part of the erasing core?
, 3! Since it is formed using a numerical aspect, sufficient erasing characteristics can be obtained to ensure erasing with a small erasing current.

〔Example〕

Hereinafter, the present invention will be explained in detail using the drawings.

The second figure is a perspective view of a cooling head according to an embodiment of the present invention. In the magnetic head of this embodiment, one of the recording/reproducing cores 4A has a larger width than the conventional magnetic head shown in FIG. 8, and the right end portion forming the recording/reproducing gap 3 is narrower. It is formed wide and protrudes. That is, as shown in FIG. 3, the width of one recording/reproducing core 4A is 2F, but the width of the right end is 6F on both sides.
It has been cut down to a width of C. The length of the notch with width G is J
Within this notch, an erasing core 7.7 is placed at a distance H from the recording/reproducing gap 3. The width of this erasing core 7.7 is smaller than the width G, and as shown in FIG. An elimination gap 1) is formed. Note that in the magnetic head of this embodiment, one of the recording/reproducing cores 4A is formed in a large size, so the recording/reproducing back core 6 is different from the recording/reproducing core 4.
It is joined to the lower end surfaces of A and 4B.

By the way, in the conventional magnetic head manufacturing method, priority is given to keeping the depth of the recording/reproducing gap 3 in the range of 20 to 50 μm, so the size of the erase gap depth A is determined by the size of the erase core 7 of the completed magnetic head. Although it is determined by
There was a large variation of ~250 μm.

For this reason, the variation in erase characteristics becomes large.
It was necessary to select and find one that satisfactorily withstands use.

In the magnetic head of this embodiment, since the size of the erase gap depth toward the recording/reproducing core 4 is determined, the variation in the erase gap depth is due to the variation in the recording/reproducing gap depth and the variation in the dimensions of the recording/reproducing core 4A. It is peace,
Since the latter is about 20 μm, the variation in erase gap depth is 50 to 100 μm. In this way, since the erasing gap depth can be formed with extremely high precision, there is no need for a sorting operation, and since the variation in erasing characteristics is small, a magnetic head with good performance and stable quality can be obtained.

In addition, in conventional magnetic heads, the erase gap depth is determined by the dimensions of the erase core 7 in the completed state, and the width of the neck 13 of the erase core 7 is limited due to restrictions on the erase track width based on the recording format of the recording device. 1) As shown in the figure, it had become thin. Therefore, when using a recording medium with high coercive force for high-density recording, a high erasing magnetic field is required, but because the neck 13 of the erasing core 7 is thin, magnetic saturation is likely to occur, and the It was not possible to supply sufficient magnetic flux to the area, and it was not possible to perform satisfactory erasure.

In the magnetic head of this embodiment, the neck 13 of the erasing core 7.7
In addition, the thickness of the recording/reproducing core 4A, which determines the erasing gap depth, is considerably larger than the erasing core 7 of a conventional magnetic head, so it can perform sufficient erasing even on magnetic recording media with high coercivity. performance can be obtained.

Furthermore, in the conventional magnetic head, the position of the outermost edge of the erase track with respect to the recording/reproducing track is as shown in FIG.
1 erase gap 1).
Therefore, due to variations in track position dimensions specific to recording devices, variations in trunk position dimensions due to expansion and contraction due to temperature and humidity of the magnetic recording medium, etc., the magnetic field recorded between recording devices When the recording medium is exchanged and used, there is a possibility that the erasing core 7 will be placed on the adjacent track, and more than half of the adjacent track will be erased during recording. When reproducing an adjacent track that has been erased more than half of the time, the output will be small and there is a high possibility that an error will occur.This phenomenon becomes more noticeable as the track density increases when the track density is 967P1 or higher. . Conventional magnetic heads require dimensional selection of the magnetic heads in order to eliminate such inconveniences, and it has been impossible to provide inexpensive magnetic heads due to the number of steps required for selection and the yield.

In the magnetic head of this embodiment, the outermost edge of the erase track is determined by the maximum width of the recording/reproducing core 4A, and the dimensions of this portion are determined by the maximum width 2F of the recording/reproducing core 4A, the recording/reproducing track width, and the center deviation. . The latter three dimensions can be machined with extremely high precision, so the outermost edge of the erase track can be formed with high precision, eliminating the need for sorting as in conventional magnetic heads, and making it possible to create a magnetic head that is inexpensive and has high reliability. Becomes the head.

Generally, in a magnetic recording device, a format for recording on a magnetic recording medium is determined as shown in FIG. 7 in order to record and reproduce data quickly and without errors. When transitioning from data recording to reproduction or from reproduction to recording, the recording/reproducing gap 3 and the erasing gap 1) are distanced apart, so as shown in FIG. requires a timing shift. In FIG. 6, TOFF indicates the time during which the erase current is turned off, and Ton indicates the time during which the erase current flows.

In order to accommodate variations in the timing difference between recording/reproducing and erasing and variations in the speed of the drive system of the magnetic recording medium, various regions called gaps are provided as shown in FIG. These areas called gaps are
This is an area that should be made as narrow as possible in order to increase data storage capacity. However, in order to narrow these gaps, the timing difference between recording/playback and erasing,
That is, it is necessary to reduce variations in the distance between the recording/reproducing gap and the erasing gap, variations in the time of the recording/reproducing and erasing circuits, or reduce variations in the speed of the drive system of the magnetic recording medium.

Among these, the magnetic head must reduce variations in the distance between the recording/reproducing gap 3 and the erasing gap 1).

In the conventional magnetic head, the distance between the recording/reproducing gap 3 and the erasing gap 1) is the recording/reproducing core 4A.

The combination accuracy of 4B and erase core 7.7 is ±100 μm, which is an extremely unsatisfactory value. This is the recording/reproduction gap 3
The recording/reproducing gap 3 and erasing are caused by variations in the distance from to the erasing core positioning part, the presence of clearance between the erasing core positioning part of the recording/reproducing cores 4A and 4B and the erasing core 7, and variations in the plate thickness of the erasing core 7. This is because the distance to the gap 1) varies.

In the magnetic head of this embodiment, the part that requires a small dimensional tolerance in the distance H between the recording/reproducing gap 3 and the erasing gap 1) is the outer shape of the recording/reproducing core 4A, so it is formed precisely by slicing. As a result, high-density recording can be realized.

FIG. 2 shows a magnetic nod according to another embodiment of the invention. In this magnetic head, one of the recording/reproducing cores 4A of the magnetic head of the embodiment shown in FIG. 1 was formed to have a large size as a whole, whereas only the upper end portion thereof was formed to have a large size. Therefore, as shown in FIG. 5, the erase gap depth is the thickness Ao of the upper end. Note that the recording/reproducing back core 6 is connected to the recording/reproducing core 4A as in the conventional magnetic head.
.

It is joined to the lower end side surface of 4B.

Even in the magnetic head of this embodiment configured in this way, the first
The same effects as the magnetic head of the embodiment shown in the figure can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, the entire erase track is erased by the erase gap, so even if a magnetic recording medium with high coercive force for high recording density is used, sufficient erase characteristics can be achieved with a small erase current. Obtainable.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a magnetic head showing one embodiment of the invention, FIG. 2 is a perspective view of a magnetic head showing another embodiment of the invention, and FIG. 3 is the same as shown in FIGS. 1 and 2. FIG. 4 is an enlarged plan view of the main part of the magnetic head shown in FIGS. 1 and 2, and FIG. 5 is an enlarged plan view of the main part showing the erase area in the magnetic head shown in FIGS. 6 is a diagram showing the relationship between the distance between the recording/reproducing gap and the erasing gap versus the erasing current timing; FIG. 7 is a diagram showing an example of the recording format on the magnetic recording medium; FIG. 9 is a perspective view showing an example of a conventional magnetic head, FIG. 9 is an enlarged plan view of the main part of the magnetic head shown in FIG. 8, and FIG. 10 is a main part showing the erase area in the magnetic head shown in FIG. Figure 1) is an enlarged sectional view of the main part of the magnetic head shown in Figure 8. In the figure, 1... Recording/playback head, 2... Erase head, 3... Recording/playback gap, 4... Recording/playback core, 5... Recording/playback. Coil, 7... Erasing core, 8... Erasing yoke, 9... Erasing coil, 10... Glass material, 1)... Erasing gap, 13...・It is the neck. Figure 1 Figure 2 Figure 3 Figure 4 A1) Figure 8 Figure 9 Figure 10 Figure 1) Figure

Claims (4)

[Claims] (1) In a magnetic head of a type in which erasing cores are placed on both sides of a recording/reproducing core that records and reproduces signals to achieve an erasing action, the erasing gap formed by the recording/reproducing core and the erasing core is A magnetic head characterized in that it is formed using two or more side surfaces of a core. (2) The magnetic head according to claim 1, wherein the depth of the erase gap is larger than the size of a portion of the recording/reproducing core that forms the erase core and the erase gap. . (3) The magnetic head according to claim 1, wherein the width of the portion of the recording/reproducing core forming the erasing core and the erasing gap is larger than the width of the erasing core. (4) The magnetic head according to claim 1, wherein a portion of the erasing gap is substantially parallel to the recording/reproducing gap.