JP2810901B2 - Magnetic head slider - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat magnetic head slider used in a floppy disk drive (FDD).

[0002]

2. Description of the Related Art FIG. 10 shows, for example, Japanese Patent Publication No. 53-31763.
FIG. 1 is a perspective view showing a conventional magnetic head slider used at a low rotation speed, which is the same system as the magnetic head slider disclosed in Japanese Unexamined Patent Publication. FIG. 11 is a plan view of this conventional magnetic head slider. In the figure, 1 is a magnetic head core made of a magnetic material such as ferrite, 2 and 3 are plate-like slider components made of ceramic or the like, 5 is a recording / reproducing gap, 6 is formed in the center and rotates in the direction of rotation of the floppy disk. A linear slider groove 7 extends to a sliding surface of the magnetic head slider with a floppy disk (FD). A indicates the sliding direction between the FD and the magnetic head slider, and B indicates the length direction of the sliding surface 7.
The sliding surface 7 and the surface of the magnetic head core 1 are located on substantially the same plane.

As shown in FIGS. 10 and 11, in a conventional magnetic head slider, a magnetic head core 1 is made up of slider constituent members 2 and 3.
The magnetic head core 1 is provided with slider components 2 and 3 on both sides to prevent abrasion due to sliding with the FD. For this reason, the width Sw of the slider sliding surface 7 is determined by the width Cw of the magnetic head core 1 and the sliding portions S1, S of the slider components 2, 3.
2 and is several times wider than the track width Tw of the recording / reproducing gap 5.

Next, the operation will be described. The magnetic head slider configured as described above functions as an electro-magnetic converter for recording information on the FD or a magnetic-electric converter for reproducing the recorded information. During recording that operates as an electro-magnetic converter, the FD is rotated to pass a signal current through a coil (not shown) incorporated in the magnetic head core 1, and a magnetic field according to this value is generated near the recording / reproducing gap 5. To record information by magnetizing the magnetic surface on the FD. At the time of reproduction that operates as a magneto-electric converter, the FD is rotated to extract the voltage of a signal induced in the coil when the magnetic flux of the magnetized magnetic surface passes near the recording / reproduction gap 5. Reproduce information. In such an electromagnetic conversion operation in recording / reproducing, the efficiency of recording / reproducing of the spacing between the magnetic gap 1 and the magnetic surface of the FD largely depends. Assuming that the deterioration of the reproduction signal voltage due to the increase in spacing is L, the spacing is h, the recording wavelength of the recorded information is λ (see FIG. 12), and the constant is K, these relations are generally expressed by the following equations. You.

[0005]

(Equation 1)

As is apparent from the above equation, it is necessary to reduce the spacing h for efficient recording and reproduction. Therefore, the recording / reproducing operation of the information is performed by bringing the sliding surface 7 of the magnetic head slider into contact with the magnetic surface of the rotating FD almost entirely.

[0007]

On the other hand, recent FDDs are required to have the following high performance. (1) Large storage capacity (2) Downward compatibility that can handle conventional information (3) Shortening of time required for information recording and reproduction To achieve large capacity, track density (TPI) or linear recording density (BPI) needs to be increased. In order to increase the TPI, as shown in FIG. 12, the track width Tmw and the track interval Tp of the information 9 recorded on the FD 8 are reduced, and to increase the BPI, the wavelength λ of the information to be recorded is shortened. . The track width Tmw
Is determined, for example, by the track width Tw of the recording / reproducing gap 5 shown in FIG. 11, and the wavelength λ of the information to be recorded is determined by the magnetic gap length G1 set from the rotation speed of the FD and the recording frequency. Requires a new magnetic head slider having a recording / reproducing gap different from one or both of the conventional track width Tw and gap length G1.

Next, a backward compatible F which has both functions of the large capacity recording / reproducing and the conventional recording / reproducing recording / reproducing.
In the DD, for example, a plurality of head cores 1a and 1b having the same track width Tw1 and Tw2 as shown in FIG. , 4 are required to have a magnetic head slider having a structure integrated by being embedded or sandwiched between them. This magnetic head slider has a sliding surface width Sw1 (about 1.4 times the conventional width) that is inevitably wider than the sliding surface width Sw shown in FIGS. When the width of the sliding surface of the magnetic head slider increases, the dynamic pressure generated by the air flowing into the sliding surface increases even at the conventional low rotation speed, and the spacing between the magnetic head slider and the FD increases. As shown in FIG. 14 (literature, Toshiba Review Vol. 43, No. 11, p. 885: 63), there is a problem that the head output is reduced and accurate recording / reproduction becomes difficult.

In order to reduce the time required for recording and reproducing information, if the FD is rotated at a higher speed than before, the air flowing into the sliding surface increases due to an increase in the number of revolutions, and the generated dynamic pressure increases. And the spacing between the magnetic head slider and the FD increases, for example, as shown in FIG. 15, so that the head output decreases and the same problem occurs.

[0010] When the spacing between the FD of the magnetic head slider increases as described above, conventionally, the head load of the magnetic head slider is increased to bring the sliding surface into stable contact with the FD. That is, the head load is increased by the amount corresponding to the increase in the dynamic pressure due to the increase in the sliding surface width and the FD rotation speed, to suppress the increase in the spacing, and to make stable contact between almost the entire sliding surface and the FD. It is a method. However, in this method, the sliding distance (the contact length between the FD and the magnetic head slider × FD rotation speed) at which the FD slides with the magnetic head slider per unit time is increased as compared with the case of the conventional slow rotation speed. As can be seen from the graph shown in FIG. 16, the rate of increase in the coefficient of friction with the increase in the number of passes (FD 1 rotation = 1 pass) is larger than in the conventional case. The problem of increased power occurs. In addition, in parallel with the above-mentioned high speed rotation of the FD for high performance, in the backward compatibility with the conventional FD, that is, in the case of switching between high and low rotation speeds, the increase in the dynamic pressure effect due to the high speed rotation is reduced. All of the increase in the head load corresponding to (1) causes an overload on the FD, which causes a problem of deterioration of sliding durability in the conventional FD.

Here, the relationship of the occurrence of spacing due to the dynamic pressure effect will be described in more detail. Assuming that the force (load capacity) for floating the magnetic head slider due to the dynamic pressure effect is W, the speed of the FD is U, the sliding surface width is Sw i , and the average spacing is h, the relationship is expressed by the following equation. Is done.

[0012]

(Equation 2)

[0013] and the load capacitance W of the magnetic head slider as can be seen from this equation, the spacing h, the speed U of the FD, is dependent on a change of the sliding surface width Sw i, particularly the change of the sliding surface width spacing Has the greatest effect on changes in

The flying characteristics of the magnetic head slider having the sliding surface width Sw shown in FIG. 11 and the magnetic head slider having the sliding surface width Sw1 shown in FIG. In comparison, in the case of the conventional rotation, the sliding surface width Sw1 is about 1.4 times the sliding surface width Sw. Therefore, the magnetic head slider of FIG. 13 is about 2.6 times (1. 4 ³ ) The stable area that floats and can be regarded as contact or contact between the sliding surface and the FD is about 1/4 or less of the length in the medium sliding direction behind the sliding surface. Even if a recording / reproducing gap for high-speed rotation is arranged in this narrow area, it is very difficult to accurately configure the sliding surface shape, and stable information recording / reproducing cannot be performed, and the performance of the FDD deteriorates. In the case of high-speed rotation, the floating surface due to the increase in the number of rotations is added in addition to the increase in the width of the sliding surface.
The contact or the length of a stable area that can be regarded as contact is shortened, and furthermore, stable recording and reproduction of information cannot be performed, and the performance of the FDD decreases.

As described above, when the magnetic head core having the recording / reproducing gaps corresponding to different recording densities is provided, and a high-speed disk is rotated to form a large-capacity, high-performance FDD, (1) sliding The head output is prevented from deteriorating due to an increase in the surface width or an increase in the spacing between the magnetic head slider and the FD in a high-speed rotation. It is an object of the present invention to provide an FDD which can secure the above-mentioned durability even when the number of sliding paths per unit time increases due to the development.

[0016]

Means for Solving the Problems According to claim 1 of the present invention.
The magnetic head slider is a magnetic disk
A first sliding surface having a first width facing the surface of the disc and the first sliding surface;
A second sliding surface having a second width equal to or less than 1
A magnetic head core is disposed on the first sliding surface for high-speed use.
A magnetic head core is arranged on the second sliding surface, and
The second sliding surface is provided near the edge.
You. The magnetic head slider according to claim 2 is rotated by a rotation source.
A first width of a first width facing the surface of the magnetic disk to be rotated;
And a second sliding surface having a second width equal to or less than the first width.
And a first magnetic head core having a first track width has
The first track is disposed on the first sliding surface and has a width corresponding to the first track width.
The second magnetic head core having the second narrower track width is
Being located on a second sliding surface, said second sliding surface being an edge
It is provided near. The magnet according to claim 3.
The head slider moves the magnetic disk rotated by the rotation source.
It has multiple sliding surfaces facing the surface and has different track widths.
Sliding surfaces having different first and second magnetic head cores
And the first and second magnetic head cores
Of at least one of the magnetic head cores.
Is provided near the rear end. Claim 4
Such a magnetic head slider according to claim 3,
The read / write gear of the first and second magnetic head cores
One of the magnetic head cores whose tips are provided near the rear end
Is used for high speed, and the other magnetic head core is used for low speed.
It is intended to be used.

[0017]

According to the first aspect, the low-speed magnetic head is provided on the first sliding surface.
Core is provided near the edge below the first sliding surface.
High-speed magnetic head core mounted on the second sliding surface
More backward compatibility / large capacity with two magnetic head cores
And equipped with only a low-speed magnetic head core
To the same head load as the conventional magnetic head slider
Can be In the second aspect, the first sliding surface has a first sliding surface.
A first magnetic head core having a track width is
The first sliding surface provided near the edge below the moving surface has the first
A second magnet having a second track width less than or equal to the track width
By mounting the head core, two magnetic head cores
A.
Conventional magnetic head slider equipped with only
It is possible to make the head load equivalent to Ida. Claim 3
Then, at least one of the first and second magnetic head cores
The recording / reproducing gap of the magnetic head core closer to the rear end
Provided, stable information can be obtained during high-speed rotation and conventional rotation.
Recording and playback are possible. Furthermore, in claim 4, claim 3
Recording / playback gap is provided near the rear end.
The magnetic head core used for high-speed
Since the head core is used for low speed,
More efficiently prevent spacing at high speeds
it can.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a magnetic head slider according to an embodiment of the present invention, FIG. 2 is a plan view showing a magnetic head slider according to an embodiment of the present invention, FIGS. 3, 4, 5, 6, and 9. 7 is a plan view showing a magnetic head slider according to another embodiment of the present invention. In the figure, 1c,
1d is a magnetic head core, 6a, 6b and 6c are slider grooves, 7a, 7b, 7c and 7d are sliding surfaces, Sw2 and Sw
3, Sw4, Sw5, Sw6, Sw7 and Sw8 are the widths of the sliding surface. In the drawings, the same reference numerals as those in the conventional example denote the same or corresponding parts, and a detailed description thereof will be omitted.

Embodiment 1 FIG. The magnetic head slider shown in FIGS. 1 and 2 has a structure in which, for example, magnetic head cores 1a and 1b made of a magnetic material such as ferrite are embedded or sandwiched in slider constituent members 2, 3 and 4 made of ceramic or the like. And a sliding surface 7b including the magnetic head core 1a (low-speed magnetic head core) and another sliding surface 7a.
A first slider groove 6a is provided therebetween, and a second slider groove 6b is provided between a sliding surface 7c including the magnetic head core 1b (high-speed magnetic head core) and the sliding surface 7b. A recording / reproducing gap 5b for high-speed rotation is disposed on the head core 1b on the outflow side in the sliding direction A of the FD with respect to the length direction B of the sliding surface. The sliding surface is disposed substantially at the center in the length direction B. The width Sw2 of each of the sliding surfaces 7a, 7b, 7c is about 1.2 to 1.3 times the width Sw of the conventional magnetic head slider, and the width Sw3 is about 0.4 to 0.55.
And Sw4 is about 0.4 to 0.45 times.

In the magnetic head slider configured as described above, when the FD rotates at a conventional low rotational speed, the low-speed magnetic head core 1a is selectively used. At this time, the load capacity of the dynamic pressure generated by the air flowing between the FD given by the equation 2 and the magnetic head slider is proportional to the sum of the cubes of the sliding surface widths, and the low FD shown in FIG. The value becomes almost equal (0.9 to 1.3) as compared with the rotation. In addition, since the head loads are equal, the true load (=
(Head load-dynamic pressure load capacity) becomes substantially equal. Therefore, the damage to the FD is not different from that of the conventional low-speed rotation type (see FIG. 11), and the spacing between the FD and the magnetic head slider is not changed. Therefore, as can be seen from the graph of FIG. 16, the sliding surfaces 7a, 7b, and 7c are almost in contact with the FD and slide on almost the entire surface with the same durability as the conventional one, and the recording and reproducing of information is performed by the recording and reproducing gap 5a for low speed. it can.

When the FD rotates at a higher speed than the conventional one, the magnetic head core 1b for high speed is selected and used. At this time, the load capacity is proportional to the speed according to Equation 2. For example, in the case of 600 to 900 rpm, which is two to three times the conventional low speed of 300 rpm, the load capacity of the dynamic pressure becomes two to three times. Since the head load is equal to the low speed rotation, F
The true load applied to D is close to zero. Therefore, the outflow side of the FD in which the recording / reproducing gap 5b is disposed in the sliding direction A (about 1/1 of the sliding surface length) with respect to the longitudinal direction B of the sliding surfaces 7a, 7b, 7c. (3 to 1/2), and slides in contact with the FD, and information is recorded and reproduced by the high-speed recording and reproducing gap 5b.

For this reason, the sliding distance of the FD sliding with the magnetic head slider per unit time is almost equal, the increase of the friction coefficient is less than the conventional one, and the change of the friction coefficient at the time of sliding due to the high speed rotation of the FD (FIG. 16) and the contact frictional force (see FIG. 17) can be reduced, and a magnetic head slider can be obtained which is free from overload at low speed rotation and can record and reproduce information stably at high speed rotation and conventional rotation. , FDD can be increased in capacity and performance.

Embodiment 2 FIG. As shown in FIG. 3, the magnetic head core 1a for low-speed rotation does not approach the magnetic head core 1b for high-speed rotation as shown in FIG. The widths Sw2, Sw3, Sw4 of the surfaces 7a, 7b, 7c do not change. Therefore, as in the first embodiment, a magnetic head slider that can reduce the contact frictional force during sliding due to the high speed rotation of the FD and can stably record and reproduce information during high speed rotation and conventional rotation can be obtained. Can be

Embodiment 3 FIG. In FIGS. 4 and 5, the width of the low-speed magnetic head core 1c is wider than 1a in FIG. 2, and the width of the high-speed magnetic head core 1d is wider than 1b in FIG.
The width S of the sliding surface of the conventional magnetic head slider shown in FIG.
For Sw, Sw2 in Examples 1 and 2 is approximately 1.
4 times or more, Sw3 about 0.6 times or more, Sw4 about 0.5 times
This is an embodiment corresponding to the case where the width is twice or more and the width of the second groove 6b is about 0.4 times or more of Sw. With such a width of the sliding surface, the load capacity given by Expression 2 becomes 1.6 times or more that of the above-described conventional magnetic head slider, and the load capacity cannot be equalized.

Here, as shown in FIG. 4, the sliding surface 7 shown in FIG.
A third groove 6c is provided in a portion corresponding to
a and 7d. The widths Sw5, Sw6, Sw7 and Sw8 of the sliding surfaces 7a, 7b, 7c and 7d are also the same as those of the conventional magnetic head slider having the low FD rotation speed shown in FIG.
When the magnetic head slider is used with the same rotational speed and the same head load, the magnetic head slider is configured by the above-described equation 2 so as to have the same load capacity as the conventional magnetic head slider. The load capacity of the magnetic head slider of this embodiment is about 0.8 to 1.
25 times, and the width of each sliding surface is about 0.8 of Sw5
0.9 times, Sw6 is about 0.8 to 0.9 times, Sw7
Is 0.55 to 0.7 times, Sw8 is about 0.7 to 0.8
It is twice. Therefore, in the first embodiment. Similarly, it is possible to reduce the contact friction force at the time of sliding due to the high speed rotation of the FD,
In addition, a magnetic head slider that can record and reproduce information stably during high-speed rotation and conventional rotation can be obtained.

Embodiment 4 FIG. In the above embodiment, the magnetic head cores 1a and 1b are sandwiched between the slider components 2, 3 and 4. However, as shown in FIG. 6, the magnetic head core 1a is attached to the slider component 3 and the magnetic head core 1b is attached to the slider component 3. A magnetic head slider embedded in the slider component 2 may be used, and the same effects as in the above embodiment can be obtained.

Embodiment 5 FIG. Further, in the above embodiment, an example is shown in which one recording / reproducing gap 5a is formed in one magnetic head core 1a or 1c, and the recording / reproducing gap 5b is formed in the magnetic head core 1b or 1d, but the tunnel shown in FIGS. For example, as in the erasing or preceding erasing, a magnetic head slider as in the above embodiment is formed by using a magnetic head core in which an erasing gap 10 or the like is provided with a plurality of gaps in one or both of one magnetic head cores 1a and 1b. The same effect can be obtained by the configuration.

Embodiment 6 FIG. In the above embodiment, the recording / reproducing gap 5b for high-speed rotation is disposed on the outflow side in the sliding direction A of the FD with respect to the length direction B of the sliding surface. Although the configuration in which the sliding surface is disposed substantially at the center in the length direction B is shown, this is an example for describing the present invention, and as shown in FIG.
The same effect as in the above embodiment can be obtained even if the recording / reproducing gap 5a of a is used at the same position as the gap 5b for high-speed rotation.

[0029]

As described above, according to the first aspect of the present invention,
In this case, the first sliding surface having the first width is not more than the first width and is closer to the edge.
A second sliding surface of a second width provided at
Magnetic head core is disposed on the first sliding surface for high speed operation.
Magnetic head core is arranged on the second sliding surface.
Therefore, in high-speed rotation, the magnetic head slider and the FD
To prevent output deterioration by suppressing the increase in spacing between
In this case , it is possible to prevent deterioration of the sliding durability of the disk due to an increase in the number of sliding passes per unit time, and to supply a high-speed disk rotation, a large capacity, and a high-performance FDD corresponding to different recording densities. According to the second aspect of the invention, the first width of the first width.
And a second width of not more than the first width and provided near the edge.
A second sliding surface having a width, and the first magnetic head core having an upper surface.
It is arranged on the first sliding surface and is narrower than the first track width.
A second magnetic head core having a track width is arranged on the second sliding surface.
Therefore, the same effects as those of claim 1 can be obtained.
You. According to the invention of claim 3, two magnetic heads are provided.
Recording of at least one of the magnetic cores
Since the reproduction gap is provided near the rear end,
Two rotation speeds at high speed rotation due to increased disk rotation speed
And stable information recording and reproduction can be performed. further,
According to a fourth aspect, in the third aspect, a recording / reproducing gear is provided.
The magnetic head core, which is provided near the rear end,
Use for speed, and use the other magnetic head core for low speed
Since it was used, the disc rotation speed was
Stable corresponding to two rotation speeds at high speed rotation due to increase
Recording and reproduction of information, especially when rotating at high speeds.
Lancing can be prevented more efficiently.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a magnetic head slider according to an embodiment of the present invention.

FIG. 2 is a plan view showing a magnetic head slider according to one embodiment of the present invention.

FIG. 3 is a plan view showing a magnetic head slider according to another embodiment of the present invention.

FIG. 4 is a plan view showing a magnetic head slider according to another embodiment of the present invention.

FIG. 5 is a plan view showing a magnetic head slider according to another embodiment of the present invention.

FIG. 6 is a plan view showing a magnetic head slider according to another embodiment of the present invention.

FIG. 7 is a plan view showing another embodiment of the magnetic head core used in the magnetic head slider according to the embodiment of the present invention.

FIG. 8 is a plan view showing another embodiment of the magnetic head core used in the magnetic head slider according to the embodiment of the present invention.

FIG. 9 is a plan view showing a magnetic head slider according to another embodiment of the present invention.

FIG. 10 is a perspective view showing a conventional magnetic head slider.

FIG. 11 is a plan view showing a conventional magnetic head slider.

FIG. 12 is a plan view showing a recording format of information on the FD.

FIG. 13 is a plan view showing a conventional magnetic head slider.

FIG. 14 is a graph showing a relationship between a sliding surface width of a magnetic head slider and a head output.

FIG. 15 is an FD in a length direction of a sliding surface of a magnetic head slider.
6 is a graph showing a spacing distribution between.

FIG. 16 is a graph showing the relationship between the number of FD passes and the friction coefficient between the FD and the magnetic head slider.

FIG. 17 is a graph showing the relationship between the number of passes of the FD and the contact friction force between the FD and the magnetic head slider.

[Explanation of symbols]

 1, 1a, 1b, 1c, 1d Magnetic head core 2, 3, 4 Slider constituting member 5, 5a, 5b Recording / reproducing gap 6, 6a, 6b, 6c Slider groove 7, 7a, 7b, 7c Sliding surface 8 Floppy disk 9 Track 10 Erase gap A Sliding direction of floppy disk B Length direction of sliding surface G1 Gap length Sw, Sw1 to Sw8 Sliding surface width Cw Width of magnetic head core Tmw Track width on FD Tw Tw recording and reproducing gap of magnetic head core Track width Tp Track spacing λ Recording wavelength

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 17/32

Claims (4)

(57) [Claims] 1. A first sliding surface having a first width facing a surface of a magnetic disk rotated by a rotation source, and a first sliding surface having a first width or less.
And a second sliding surface having a second width of
A high-speed magnetic head having a core disposed on the first sliding surface;
A core is disposed on the second sliding surface and the second sliding surface
A magnetic head slider, wherein a moving surface is provided near an edge . 2. A surface of a magnetic disk rotated by a rotation source.
A first sliding surface having a first width opposed to the first width and not more than the first width
And a second sliding surface having a second width, and a first track width.
Of the first magnetic head core is disposed on the first sliding surface.
And a second track width smaller than the first track width.
A second magnetic head core is disposed on the second sliding surface,
And magnetic head slider you wherein said second sliding surface is provided on the edge closer. 3. A surface of a magnetic disk rotated by a rotation source.
Having a plurality of sliding surfaces facing each other and having different track widths.
The first and second magnetic head cores are arranged on different sliding surfaces, respectively.
And a small number of the first and second magnetic head cores.
At least the gap for recording / reproducing of one magnetic head core
Magnetic head slider characterized in that provided in the rear end. 4. The first and second magnetic head cores.
One of the recording / reproducing gaps
Using the magnetic head core for high speed, the other magnetic head
The magnetic head slider according to claim 3 , wherein the core is used for low speed .