JPS63266605A - Magnetic head - Google Patents

Abstract

PURPOSE:To record and reproduce a signal in the condition to minimize sufficiently a load to a magnetic recording medium by contacting stably only the vicinity of a magnetic gap to the magnetic recording medium. CONSTITUTION:A magnetic gap 15 is arranged to a rear edge side from the magnetic recording medium 30 travelling direction length center of a plane part and the flow-out side of the area of the plane surface is made smaller than the flow-in side of the magnetic recording medium 30. For example, by providing a taper so that an air fluid can occur from a flow-in edge side of the magnetic recording medium 30 of a magnetic head, the front edge of a magnetic head 10 automatically floats at the time of the travelling of the magnetic recording medium 30. A condition in which only the vicinity where the magnetic gap 15 is located on the rear edge side is partially contacted with the magnetic recording 30, can be created. Thus, since recording and reproducing to the magnetic recording medium can be stably executed, while the friction of a magnetic head and a magnetic recording medium is made sufficiently smaller, the durability and reliability of the magnetic recording medium can be improved.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a magnetic head that records and reproduces signals by contacting a magnetic recording medium, and particularly relates to a magnetic head that records and reproduces signals by contacting a magnetic recording medium. This article relates to an improved magnetic head.

(Prior Art) Conventionally, as a magnetic recording and reproducing device for recording and reproducing signals,
Various floppy disk devices are used. 1st
FIG. 0 is a diagram showing a magnetic head used in a general floppy disk device, and the magnetic head 80 is composed of two sliders 81 and 82, one of which is
1 has a magnetic core 83 formed therein. Further, the magnetic recording medium facing surface 84 of the magnetic head 80 has a planar shape. The magnetic gap 85 is located approximately at the center of the length of the flat portion of the magnetic core 83 in the direction in which the magnetic recording medium runs.

There are two types of floppy disk drives: single-sided and double-sided. The double-sided type is more advantageous in terms of storage capacity. The double-sided floppy disk device has a magnetic head 80 having the above structure.
As shown in FIG. 11(a>(b)), the magnetic recording medium 90
is sandwiched from both the front and back sides, and signals are recorded and reproduced in this state. The upper and lower magnetic RAD slider flat parts face each other, and the magnetic core 83 is connected to the upper and lower magnetic heads 80.
They are located so that they do not face each other in order to prevent magnetic interference.

Also, the flat parts of the upper and lower magnetic heads 80 are connected to the magnetic recording medium 9.
12, both or either of the magnetic heads 80 are supported for easy contact with the magnetic head 80. That is, the magnetic head 80 is attached to a gimbal spring 91, and the gimbal spring 91 is fixed to a carriage 92. A pivot 93 is provided on the carriage 92, and this pivot 93 acts on the center of the length of the flat part of the magnetic head in the running direction of the magnetic recording medium.
The pressing force is applied to the magnetic head 80 via the magnetic head 80 . By supporting the magnetic head 80 in this manner, the magnetic head 80 has a degree of freedom in fixing and rotating around the point of action of the pivot 93, preventing uneven contact caused by mounting errors, and ensuring that the flat surface of the magnetic head 80 is fixed. easily magnetic recording medium 9
I try to make it touch 0.

The magnetic head and magnetic head support structure of a typical double-sided floppy disk drive have been briefly explained above.
In conventional double-sided floppy disk drives, in order to bring the magnetic gap into contact with the magnetic recording medium, the entire surface of the magnetic head facing the magnetic recording medium is brought into contact with the magnetic recording medium.

By the way, the points that must be taken into consideration when designing the magnetic head shape and magnetic head support structure are as follows: 1. Allow for errors in manufacturing and installation, and determine how large a margin the magnetic gap and magnetic recording medium can be brought into contact. Can you do it.

■ How can we reduce the load on magnetic recording media?

There are two points.

As mentioned above, in the case of a conventional double-sided floppy disk drive, in order to satisfy the first point, the surface of the magnetic head facing the magnetic recording medium is made flat, the magnetic head is gimbally supported, and the entire flat surface of the magnetic head is The idea is to bring the magnetic gap into contact with the magnetic recording medium by bringing the magnetic gap into contact with the magnetic recording medium. Further, in order to provide a larger margin, a method is adopted in which the pressing force of the magnetic head is increased or the area of the flat surface of the magnetic head is decreased, that is, the contact surface pressure of the entire surface of the flat surface of the magnetic head is increased. However, increasing the contact pressure on the entire flat surface of the magnetic head goes against the second consideration, which is to reduce the load on the magnetic recording medium. In other words, increasing the contact pressure on the entire flat surface of the magnetic head causes deterioration in the durability of the magnetic recording medium.

On the other hand, with the recent development of information processing technology, demands for higher capacity and reliability of magnetic recording and reproducing devices are increasing. In floppy disk drives, perpendicular magnetic recording media such as Co-Cr and B are used as media capable of high recording density.
Media such as a-Fe are being actively developed. Under these circumstances, in order to make full use of these media, establishing a technology to reduce the load on the magnetic recording medium and to obtain stable contact between the magnetic gap and the magnetic recording medium has become a major research topic.

(Problems to be Solved by the Invention) Conventionally, in order to easily bring the magnetic gap into contact with the magnetic recording medium, it is necessary to increase the contact pressure on the entire surface of the magnetic head facing the magnetic recording medium. However, there is a contradictory problem in that increasing the contact pressure deteriorates the durability of the magnetic recording medium.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to easily bring a magnetic gap and a magnetic recording medium into contact with each other while the load on the magnetic recording medium is sufficiently small. An object of the present invention is to provide a magnetic head that can contribute to improving the durability of a medium and improving the reliability of a magnetic recording/reproducing device.

C Structure of the Invention] (Means for Solving the Problems) The gist of the present invention is to bring only the vicinity of the magnetic gap into stable contact with the magnetic recording medium so that the signal can be transmitted while the load on the magnetic recording medium is sufficiently reduced. The objective is to record and play back information.

That is, the present invention has a flat portion facing the magnetic recording medium,
In a magnetic head that records and reproduces signals by bringing a magnetic gap formed in the flat part into contact with the medium, the magnetic gap is arranged on the rear end side of the flat part from the center of the length of the magnetic recording medium in the running direction, Further, the area of the flat portion is smaller on the outflow side of the magnetic recording medium than on the inflow side.

(Function) In the conventional magnetic head and magnetic head support structure, in order to make the contact surface pressure between the magnetic gap part and the magnetic recording medium Po, the entire surface of the magnetic head part is set to P as shown in FIG. 7(a).
The contact surface pressure will be o. Therefore, magnetic head 1
The planar area of S1 is the magnetic head 10 and the magnetic recording medium 3.
0, the magnetic recording medium 30 moves from the magnetic head 10 to Fl lPOS ″μ...
It will be subject to the frictional force of (1). This is shown in Figure 7 (
The same holds true even when there is a change in contact pressure as shown in b).

In contrast, in the present invention, for example, by providing a taper so that air fluid is generated from the magnetic recording medium inflow end side of the magnetic head, the front end of the magnetic head 10 automatically flies when the magnetic recording medium runs, and the rear end It is possible to create a state in which only the vicinity of the magnetic gap located on the side is in partial contact with the magnetic recording medium 30. FIG. 8 shows the state of contact between the magnetic head 10 and the magnetic recording medium 30 at this time.

Here, the boundary between the floating part and the contacting part of the magnetic head 10 is taken as the center position of the magnetic head flat part in the magnetic recording medium traveling direction, the magnetic gap is taken as the rearmost end of the magnetic head flat part, and the magnetic gap The contact pressure at the part is P
o. Assuming the above three points, the magnetic recording medium 30
from the magnetic head 10 at most F2 = (1/4) Pa −3・u”・(2
) will only be affected by friction. Note that although the magnetic recording medium 30 also receives a frictional force from the air fluid, this value is sufficiently small compared to the solid friction between the magnetic head 10 and the magnetic recording medium 30, so it can be ignored. In other words, the more the boundary between the floating part of the magnetic head and the contact part is at the rear end of the magnetic head, the smaller the frictional force can be.

Therefore, according to the present invention, the load on the magnetic recording medium can be sufficiently reduced, and the magnetic gap and the magnetic recording medium can easily come into contact.

By the way, under conditions of relative speed and load between the magnetic head and the magnetic recording medium, the state shown in FIG. 8 can be achieved, but if the relative speed is further increased, the entire flat part of the magnetic head will fly as shown in FIG. I will do it. this is,
This creates a spacing between the magnetic gap and the magnetic recording medium, leading to deterioration of electromagnetic conversion characteristics.

FIG. 9 shows the force acting on the magnetic head at this time.

Here, the pivot 13 which is the center of rotation of the magnetic head 10
Fa is the air-hydraulic force generated on the flat surface of the magnetic head at the front end from the point where it acts, Fb is the air-hydraulic force generated at the flat surface of the magnetic head on the rear end side from the pivot point, Let La be the distance to the center of air fluid pressure generated on the rear end side of the magnetic head, and Lb be the distance from the pivot point to the center of air fluid pressure generated on the flat surface of the magnetic head on the rear end side.Fa - La - Fb I Lb-0'' (3). In this case, the entire flat part of the magnetic head will float. Also, as shown in FIG. This is the case of 4). In the present invention, the width of the flat part of the magnetic head is made larger on the magnetic recording medium inflow side than on the outflow side, thereby reducing Fa-
La is increased and Fb and Lb are decreased. Therefore, the condition of equation (4) is easily satisfied, that is, the structure is such that the front end side of the flat part of the magnetic head floats and the rear end side easily comes into contact.

Thus, according to the present invention, the frictional force between the magnetic recording medium and the magnetic head can be sufficiently reduced, and contact between the magnetic gap and the magnetic recording medium can be easily obtained.

(Example) Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.

FIG. 1 is a schematic diagram showing a magnetic head according to an embodiment of the present invention. The magnetic head 10 has two sliders 11
．． 12, one slider 11 has a core 13
is formed. The surface 14 of the magnetic head 10 that comes into contact with the magnetic recording medium is processed into a flat surface, and this flat portion 14
The width is smaller on the outflow side of the magnetic recording medium than on the inflow side with respect to the magnetic recording medium running direction. In other words, 1. The area of the magnetic head flat portion 14 is smaller on the outflow side of the magnetic recording medium than on the inflow side with respect to the magnetic recording medium running direction. An edge 16 on the side surface of the magnetic recording medium inflow end of the magnetic head 10 is chamfered to generate air fluid pressure.

Further, the magnetic gap 15 is formed not at the center of the flat portion 14 but at the rear end side in the magnetic recording medium traveling direction (for example, at a position approximately 0.9 from the magnetic recording medium inflow end of the magnetic head flat portion). . Here, there are two magnetic gaps 15,
The front is the R/W gap, and the rear is the erase gap. Note that 17 in the figure indicates an excitation coil wound around the magnetic head 10.

As shown in FIG. 11, the magnetic heads 10 are arranged facing each other with a double-sided recording/reproducing type flexible magnetic recording medium in between. At this time, at least one of the magnetic heads 10 is arranged as shown in FIG. The magnetic recording medium is supported by the mechanism shown so as to have rotational freedom in the running direction of the magnetic recording medium and in the radial direction of the magnetic recording medium.

With such a configuration, the contact state between the magnetic head and the magnetic recording medium is as shown in FIG. 8, and the magnetic head 1
The contact area with the magnetic recording medium 30 of 0 is small. In this case, since the magnetic head 10 and the magnetic recording medium 30 are in sufficient contact in the portion where the magnetic gap 15 is formed, recording and reproduction of signals can be performed stably. Therefore, the load on the magnetic recording medium 30 can be reduced, and the durability of the magnetic recording medium 30 can be improved. Furthermore, since the contact pressure between the magnetic helad 10 and the magnetic recording medium 30 can be sufficiently increased at the magnetic gap position, recording and reproducing of signals can be performed stably, and the reliability of the device can be improved. is also possible.

In addition, since the area of the flat part of the magnetic head is smaller on the outflow side of the magnetic recording medium than on the inflow side with respect to the magnetic recording medium running direction, the front end side of the magnetic head 1o floats and the rear end side contacts. can be easily realized. Furthermore, since the load on the magnetic recording medium 3° is reduced, there is an advantage that the power consumption of the motor for running the magnetic recording medium 30 can be reduced.

The inventors conducted an experiment using the example head and the conventional head, focusing on the output during signal recording/reproduction and the frictional force between the magnetic head/magnetic recording medium, and using the load as a parameter. The experimental results are shown in Figure 2.

Here, the O mark is the maximum output ratio in the example, the Δ mark is the friction coefficient in the example, the * mark is the maximum output ratio in the conventional example, and the mu mark is the friction coefficient in the conventional example. Further, the maximum output ratio is the ratio of the output value under each load to the output value when the magnetic gap and the magnetic recording medium are in ideal contact.

The maximum output ratio increases as the load increases in both the embodiment and the conventional example, and becomes constant at 1.0 from a certain load onwards. In other words, the magnetic gap and the magnetic recording medium were in ideal contact under this load or more.

In the case of the conventional example, the friction coefficient does not depend on the load and is approximately constant at 0.2. On the other hand, in the example, 0 in the low load region
．． 05 or less, and as the load increases, the coefficient of friction approaches 0.2 in the case of the conventional example. The most noteworthy thing here is that in this example, as can be seen from the load of 20 gf, the friction coefficient is extremely low, 0.03, which is about 1/7 of the conventional example, and the maximum output ratio is 1. 0, which means that ideal contact between the magnetic gap and the magnetic recording medium was achieved.

FIGS. 3 to 6 are diagrams each showing a schematic configuration of other embodiments of the present invention. In the example shown in FIG. 3, the width of the magnetic head flat portion 14 is not continuously reduced in the direction of the magnetic recording medium, but is changed stepwise. In the example shown in FIG. 4, a region A is provided on the magnetic recording medium inflow side of the magnetic head flat section 14, the width of which is smaller than the width on the outflow side. In either example, when viewed from the entire plane, the width of the flat portion is smaller on the outflow side than on the inflow side, and the same effects as in the previous embodiments can be obtained.

Further, in the example shown in FIG. 5, on the outflow side of the magnetic head flat section 14,
By forming grooves 18 perpendicular to the recording medium running direction, the area on the outflow side is made smaller than that on the inflow side. Instead of this groove 18, a hole may be formed on the outflow side of the flat magnetic head portion 14. Further, in the example shown in FIG. 6, the magnetic head flat portion 14 is formed over substantially the entire area of the magnetic head in the direction in which the magnetic recording medium runs. Of course, even with such a configuration, the same effects as in the previous embodiment can be obtained.

Note that the present invention is not limited to the embodiments described above, and can be implemented with various modifications without departing from the gist thereof. For example, the position of the magnetic gap is
It may be located on the rear end side of the center of the length of the magnetic recording medium running direction of the flat portion of the magnetic head, and can be changed as appropriate depending on the specifications. Further, instead of supporting one of the magnetic heads by the support mechanism as shown in FIG. 12, the present invention can be applied to a structure in which both magnetic heads are supported by the support mechanism.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to stably perform recording and reproduction on a magnetic recording medium while the frictional force between the magnetic head and the magnetic recording medium is sufficiently reduced. Therefore, it is possible to contribute to improving the durability of the magnetic recording medium and also to improving the reliability of the magnetic recording/reproducing device.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a schematic configuration of a magnetic head section according to an embodiment of the present invention, and Fig. 2 is for explaining the effects of the above embodiment, and shows the relationship between the maximum output ratio and the coefficient of friction with respect to the load. Characteristic diagrams, FIGS. 3 to 6 are diagrams showing the schematic configuration of other embodiments, and FIGS. 7 to 9 are diagrams for explaining the present invention in detail, respectively, and FIGS. 10 to 12. are diagrams for explaining the conventional problems. 10...Magnetic head, 11.12...Slider, 1
3... Core, 14... Plane part, 15... Magnetic gap, 16...: ff-J part, 17... Excitation coil, 18... Groove, 23... Pivot, 30...Magnetic recording medium. Applicant's agent Patent attorney Takehiko Suzue Figure 3 Figure 7 Hand stop direction

Claims (6)

[Claims] (1) In a magnetic head that has a flat part facing a magnetic recording medium and records and reproduces signals by bringing a magnetic gap formed in the flat part into contact with the medium, the magnetic head has a flat part facing the magnetic recording medium. 1. A magnetic head, characterized in that the flat portion is located on the rear end side with respect to the center of the length in the running direction of the medium, and the area of the flat portion is smaller on the outflow side of the magnetic recording medium than on the inflow side. (2) The magnetic head according to claim 1, wherein the width of the flat portion is smaller on the outflow side of the magnetic recording medium than on the inflow side. (3) The magnetic head according to claim 1, wherein a groove or a hole is provided on the outflow side of the magnetic recording medium of the flat portion. (4) The magnetic recording medium is a flexible magnetic recording medium of double-sided recording/reproducing type, and this flexible magnetic recording medium is sandwiched from both the front and back sides, and signals are recorded and reproduced, and the magnetic recording medium is read from both sides. 2. The magnetic head according to claim 1, wherein at least one of the sandwiched magnetic heads is supported so as to have a degree of freedom of rotation around the radial axis of the magnetic recording medium. (5) The magnetic head according to claim 4, wherein the center of rotation that provides the degree of freedom of rotation is provided closer to the inflow side of the magnetic recording medium than the magnetic gap. (6) The magnetic head according to claim 1, wherein an edge portion of the flat portion in the running direction of the magnetic recording medium is chamfered.