JP2655871B2 - Composite magnetic head - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head that records and reproduces information on a flexible disk, and more particularly to a composite magnetic head that can perform recording and reproduction with different track widths. .

[Related Art] In recent years, with the development of personal computers and the like, flexible disks have been frequently used as simple recording media. One method of improving the recording density of a flexible disk is to increase the track density. The number of tracks per inch, that is, TPI, is used as a unit to represent the recording density based on the track density. However, the improvement in the recording density due to the increase in the track density is rapid, and the track density is 48 TPI in the past. However, it has since increased dramatically to 96 TPI and more recently to 400 TPI or more. As a result, some flexible disk devices record and reproduce at 48 TPI and some record and reproduce at 96 TPI, and some record and reproduce at 400 TPI or more.

In this way, in the state where flexible disk devices that record and reproduce at multiple modes of track density coexist, the device for 48 TPI was conventionally dedicated to 48 TPI and the device for 96 TPI was dedicated to 96 TPI, but 96 TPI was also used for 48 TPI. A dual-use magnetic head has been developed which can also be used for
016). This is basically a narrow head for 96 TPI, with two types of erase heads at different positions on both sides, and only one of them according to the width of the part between tracks. The erase width is changed by exciting or exciting both. When recording with a wide width using this head and reproducing it with a wide 48 TPI head, the signal of an adjacent track is prevented from entering as noise, thereby functioning as a dual-purpose magnetic head. I have to.

[Problems to be Developed by the Invention] In the above-described conventional technique, when recording is performed by the dual-use apparatus, there is an advantage that recording can be performed by a method compatible with the method of the reproducing apparatus. On the other hand, when reproducing with this apparatus, it is possible to reproduce a narrow-width recording, but not to reproduce a wide-width recording. Further, even when performing wide-width recording as described above, only a portion having a narrow track width is used, so that there is a disadvantage that the output is reduced. The present invention has been made in view of the above circumstances, and one composite magnetic head can cope with two types of track widths.
It is possible to reduce the overall length and reduce the size, and to arrange the coil of the magnetic head for recording and reproduction and the coil of the magnetic head for erasure so as not to interfere with each other. It is an object of the present invention to provide a composite magnetic head having a configuration that can be performed.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a first magnetic head core having a gap and a second magnetic head core having a gap narrower than the gap. The width direction of each gap intersects the running direction of the flexible disk, and is arranged in series in the running direction of the flexible disk. A coil is mounted on each of the first magnetic head core and the second magnetic head core, and On both sides in the width direction of the gap of the magnetic head core,
Providing a pair of erasing heads facing the magnetic head core via an erasing gap on the side of the magnetic head core,
A back core connecting the pair of erasing heads is provided so as to bypass the coil of the magnetic head core, and a part of the back core is provided with a coil of the erasing head separated from the coil of the magnetic head core. .

Next, a tracking servo mechanism may be provided in the above configuration.

[Operation] In such a composite magnetic head, by selectively exciting one of the two types of magnetic heads, recording is performed in accordance with the track width of the magnetic head to be used for reproduction. Reproduction is performed by selectively using only signals picked up by a magnetic head corresponding to the track width adopted when recording on a recording medium.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of a composite magnetic head according to the present invention, in which a composite magnetic head core 3 is mounted in a mounting groove 2 of a slider 1. FIG. The composite magnetic head core 3 is configured such that a first magnetic head core 4 corresponding to the near side and a second magnetic head core 5 corresponding to the rear in the running direction (arrow) of the flexible disk are integrally joined via a bonding layer 6. ing. The width of the gap 7 of the first magnetic head core 4 is set to be equal to the width of the magnetic head core 4 itself, and a straddle-type erasing head 8 is provided on a side portion thereof. The second magnetic head core 5 has a gap 9
Are formed on both sides of the head core, and the gap 9 is narrower than the head core. These first
And the second magnetic head cores 4 and 5 respectively join the pair of half cores 11, 12, 13 and 14 on the gap forming surface,
The back core 15 is arranged in the back gap portion, and each of them independently constitutes a magnetic circuit.

Hereinafter, the manufacturing method will be described with reference to FIG.
First, the blocks of the first magnetic head core 4 and the second magnetic head core 5 are manufactured. The block of the first magnetic head core 4 is formed by abutting one of a half-core block 11a having a T-shaped cross section to form a T-shaped portion and a half-core block 12a having a L-shaped cross section to form an L-shaped portion. After a film such as SiO ₂ is formed on the surface by sputtering, the two are joined using a bonding glass or the like (FIG. 2A). The block of the second magnetic head core 5 is formed by cutting out the track width regulating grooves 10 in the abutting surfaces of the half core block 13a having a T-shaped cross section and the half core block 14a having an I-shaped cross section, respectively. Then, a film for a gap is formed on one of the abutting surfaces, and then bonding is performed (FIG. 2B). Next, these L-shaped half-core blocks
The back of the I-shaped half-core block 14a is bonded to the back of the I-shaped half-core block 14a using a bonding glass or the like.
Along the center line of 10, the sheet is cut into a thin plate as shown by line A in FIG.

The composite magnetic head core 3 is assembled to the slider in a process as shown in FIG. That is, the composite magnetic head core 3 is inserted into the mounting groove 2 formed in the slider, and fixed with an adhesive or the like. Next, after the coils 16a, 16b are fitted to the T-shaped half cores 11, 13 of the first and second magnetic heads 4, 5, the ends of the T-shaped half cores 11, 13 are connected to each other. The back core 15 is fixed using the holding member 17. This back core 15 has two square rod-shaped head cores 15.
a, 15b at a position corresponding to the junction between the first magnetic head core 4 and the second magnetic head core 5;
Are connected in series, and as described above, the first,
An independent magnetic closed circuit is formed for each of the second magnetic head cores 4 and 5.

As shown in FIG. 5, the erasing head 8 is formed by abutting a pair of core plates 8a and 8b and joining them by a bonding layer 8c.
By sandwiching the L-shaped half core 12 of the magnetic head core 4 of FIG.
18 is formed. This erasing head 8
It is fitted to an erasing head mounting member 19 provided on the slider 1 so as to be orthogonal to the mounting groove 2. Further, a U-shaped erasing back core 21 is attached to and fixed to the slider 1 so as to be sandwiched between both ends of the erasing head 8. The coil 22 is mounted on the erasing back core 21 not on the bottom 21a but on the side 21b of the U-shaped portion. In this manner, the coil 16a or the coil 16a mounted on the first magnetic head core 4 is mounted. The coil 16b mounted on the magnetic head core 5 does not interfere with each other, thereby preventing the erasing coil 22 from projecting to the side or upper part of the slider 1.

Although the erasing head 8 is provided only on the first magnetic head core 4 in the drawing, the erasing head 8 may be provided on the second magnetic head core 5 having a narrow track width. This is because, in a flexible disk drive device having a TPI of 400 or more, since the track width itself and the gap between the track widths are narrow, it is necessary to make the position to be scanned by the head accurate, so that a tracking servo mechanism is provided. This is because there is no need to eliminate noise on both sides after recording.

In the flexible disk drive of this embodiment, when a 3.5-inch diameter flexible disk is used, three recording / reproducing modes having a total storage capacity of 1 MB (megabit), 2 MB, and 6 MB can be switched and used. It is the first in 1MB and 2MB mode.
Is used. In this case, the number of tracks per inch is the same (135 TPI), and the recording capacity is changed by changing the recording frequency. In the 6 MB recording / reproducing mode, the second magnetic head core 5 is used, and the track density in this case is 406 TPI. When using a 5-inch flexible disk, the track density is 48 TPI, 2M in 1MB mode.
96TPI at B (6MB mode is not used for 5 inch flexible disk).

Note that the gap width of the second magnetic head core 5 can be set arbitrarily as needed, and the recording / reproducing mode is set to 4 MB or 8 MB by making this width wider or narrower than that of 6 MB. Can be.

When recording in the 1 MB mode using the composite magnetic head core 3, the recording is performed by exciting the first magnetic head core 4 and the erasing head 8, and then the noise signals on both sides of the track are straddled. Erasing is performed by the mold erasing head 8. When recording in the 2 MB mode, the recording density is improved by using the first magnetic head core 4 and increasing the operating frequency.

On the other hand, when recording is performed in the 6 MB mode, only the second magnetic head core 5 is excited to perform recording with a high track density. In this case, by operating the tracking servo mechanism to precisely determine the center of the track width, the gap of the first magnetic head core 4 accurately traces the track in the previous recording, so that there is no need to use an erasing head. .

In the above example, the second magnetic head core 5 is not provided with an erasing head. However, the second magnetic head core 5 may be provided with an erasing head. In this case, the erasing head may be provided symmetrically in FIG. 1, that is, the coil may be provided on the same side of the U-shaped back core as the first magnetic head core.

FIG. 6 shows another method of manufacturing the magnetic head of the above embodiment, in which the sliders 1a, 1a and the mounting members 19a, 19a are divided into two parts, and the magnetic head is moved between these sliders 1a, 1a. Then, after fixing the erasing head 8 and bonding them together using glass or an adhesive, the erasing head 8 is manufactured. In this method, the manufacturing process is simplified, the manufacturing cost can be reduced, and the accuracy can be improved.

[Effects of the Invention] As described in detail above, the present invention provides a composite magnetic head by arranging two magnetic head cores having different track widths in series in the running direction of a flexible disk, thereby forming one magnetic head. In this situation, recording or reproduction with two track widths can be performed in each mode, and recording and reproducing devices employing different track densities coexist. There is an advantage that a recording / reproducing apparatus with good cost performance can be manufactured. In this method of manufacturing the magnetic head core, since the blocks of the respective heads are attached to the sliders, the steps are not particularly complicated, and the manufacturing cost does not increase. Also, since the magnetic head cores are arranged in series, if the positions of the coils are opposite, each magnetic circuit becomes independent, and the magnetic field of one head core does not interfere with the other head,
Good recording and reproduction without noise is performed. Next, on both sides of the gap of at least one of the magnetic head cores, a pair of erasing heads is provided via an erasing gap to the side of the magnetic head core, so that all of the two magnetic head cores and the erasing head are flexible. The overall length can be reduced as compared with a configuration in which the disks are arranged in the running direction of the disks, and the size of the composite magnetic head can be reduced.

In addition, by providing the coil of the erasing head at a distance from the coil of the magnetic head core on the back core of the erasing head provided around the magnetic head core, interference between the erasing coil and the coil of the magnetic head core can be avoided. it can.

Further, in the above configuration, by adding a tracking servo mechanism for strictly defining the center of the track width, the gap of the magnetic head can accurately trace the track in the previous recording, so that the erasing head can be omitted. become.

[Brief description of the drawings]

FIG. 1 is a plan view of a slider incorporating the magnetic head core of the present invention, FIG. 2 is an enlarged view of a main part thereof, FIG. 3 is a front view of the same main part, and FIGS. FIG. 5 is a perspective view showing a method of manufacturing the magnetic head core, FIG. 5 is a perspective view showing a step of incorporating the magnetic head into the slider, and FIG. 6 is a perspective view showing another method of incorporating the magnetic head into the slider. 3 Composite magnetic head core 4 First magnetic head core 5 Second magnetic head core

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yuichi Hayakawa 5-33-1, Shiba, Minato-ku, Tokyo Within NEC Corporation (56) References JP-A-62-121903 (JP, A) JP-A-62 −52781 (JP, A)

Claims (2)

(57) [Claims] A first magnetic head core having a gap and a second magnetic head core having a gap narrower than the gap, the width direction of each gap intersects the running direction of the flexible disk, and A coil is mounted on each of the first magnetic head core and the second magnetic head core in series in the running direction, and a coil is mounted on both sides in the width direction of the gap of the at least one magnetic head core. A pair of erasing heads facing the magnetic head core via an erasing gap are provided, a back core connecting the pair of erasing heads is provided to bypass the coil of the magnetic head core, and a part of the back core is provided. A coil of an erasing head provided apart from the coil of the magnetic head core. Composite magnetic head. 2. The composite magnetic head according to claim 1, further comprising a tracking servo mechanism.