JP3270797B2 - Negative pressure 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 magnetic recording / reproducing apparatus using a flexible magnetic disk, and more particularly to a material of a negative pressure slider for contacting a magnetic head with a magnetic disk.

[0002]

2. Description of the Related Art Conventionally, for example, in a magnetic recording / reproducing apparatus for an electronic still camera, a member for generating a negative pressure is arranged around the magnetic head in order to make good contact between the magnetic head and the magnetic disk. A so-called negative pressure slider contact system has been put to practical use.

The negative pressure slider system has various advantages as compared with the conventional opposed slider system, but also has a problem that it can be a disadvantage. In the negative pressure slider contact method, since the negative pressure slider is disposed on the recording / reproducing surface side, damage of the magnetic disk by the negative pressure slider is a fatal defect of damage to recorded information. Therefore, in order to stably contact the magnetic head and the magnetic disk, it is necessary to minimize the damage to the disk while attracting the magnetic disk to the negative pressure slider.

Basically, the magnetic disk and the negative pressure slider are in contact with each other via the air film. However, the air film is extremely thin, and various measures have been taken to prevent direct contact between the disk and the slider. is necessary. It requires quite delicate control of controlling the magnitude of the negative pressure, controlling the negative pressure distribution, and controlling the surface condition of the slider.

As a conventional negative pressure slider material, a metal is used as a material, and the processing method is such that the shape is processed by cutting, pressing, sintering, or the like to obtain a shape meeting the above requirements. It was to give performance.

[0006]

However, in these manufacturing methods, the shape is restricted, and in consideration of the accuracy of the disk-facing surface, surface treatment such as lapping is required as a finishing process, which is a factor of cost increase. It also becomes a factor of poor yield.

In addition, there is another problem that the contact state changes depending on the disk due to variations between the disks, and if the contact state is poor, the magnetic disk is damaged by the negative pressure slider.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems of the prior art by using a material mainly composed of a polymer substance and manufacturing the same by molding. The present invention provides a negative pressure slider that does not require post-processing, avoids damage to the magnetic disk, increases the yield at a low cost, and sucks the flexible magnetic disk by the negative pressure generated by the rotation. In the negative pressure slider of the magnetic recording / reproducing device to be brought into contact with
The negative pressure slider is characterized in that the material of the negative pressure slider is plastic, and the hardness of the convex portion is not less than Rockwell hardness M50.

[0009]

According to the structure of the present invention, even when magnetic disks having various characteristics are used, the contact characteristics between the magnetic head and the negative pressure slider are stabilized, and the magnetic disks are hardly damaged.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a contact state between a magnetic head and a negative pressure slider in a magnetic recording / reproducing apparatus using a negative pressure slider, and FIG. 2 shows an example of a shape of the negative pressure slider. In the drawings, the same parts are denoted by the same reference numerals.

In the figure, 1 is a negative pressure slider, 2 is a magnetic head, and 3 is a magnetic disk. The direction of the arrow is the disk rotation direction, and a negative pressure is generated by disposing the step portion 1A of the negative pressure slider 1 on the disk entry side. Therefore, the magnetic disk 3 is attracted to the negative pressure slider 1 side and approaches the convex surface portion 1B of the negative pressure slider 1 via an extremely thin air film. Therefore, depending on the surface condition of the convex portion 1B, partial contact may occur.

Further, the negative pressure is generated by the air flow due to the rotation of the disk, and it is necessary to keep the gap within a certain range. In particular, it is necessary to keep this gap at the start of disk rotation. However, since magnetic recording devices for flexible disks are generally disk-exchangeable, it is necessary to keep the gap before rotation of all disks within a certain range. For that purpose, the negative pressure slider must be arranged with respect to the disk having a high magnetic surface, and when the low disk is set, the slider will push up the disk. Will come into contact with.

FIG. 3 shows the result of evaluation of the relationship between the slider height and the disk rotation load when the disk height is set to 0. As the slider becomes higher, the disk rotation load increases. This implies contact between the disk and the slider.

Conventional negative pressure slider materials include:
When metal is used and the disk contacts the slider, physical destruction of the magnetic surface of the disk occurs. When the convex surface 1B of the negative pressure slider 1 has a convex surface, even if the size is extremely small, the disk is damaged. For example, it has been confirmed that a disc is scratched even with a protrusion of several tens nm. In addition, conventional metal sliders need to remove surface protrusions in the surface finishing process, and it is very difficult to manage them on the order of nanometers. There was a problem with quality and yield.

The present invention provides a negative pressure slider which does not cause a fatal damage to a magnetic disk by using a material of the negative pressure slider 1 as a polymer material. Also, by performing the molding process, the manufacturing process can be greatly reduced.

Comparing the surface condition of the convex portion 1B of the conventional metal negative pressure slider and the convex portion 1B of the polymer material of the present invention, the surface condition of the polymer material is much larger than that of the metal. It does not damage and does not cause fatal scratches on the magnetic disk.

However, in a negative pressure slider made of a polymer material, if a softer material is used by reducing its hardness, the disk will surely not be damaged.
This has an adverse effect on disk rotation fluctuation. To be precise,
Initially, there is almost no effect on the fluctuation of the disk rotation, but as the sliding with the disk is repeated, a worsening phenomenon occurs.

FIG. 4 shows a change state of the disk rotation fluctuation when the disk and the slider are slid when the disk and the slider are slid at the initial time and after the elapse of 30 hours. In addition, the rotation fluctuation indicates the ratio of the deviation from the normal rotation speed by%.
Expressed by In the early stage, the fluctuation was small and almost constant, but after 30 hours, the fluctuation was large.

Therefore, it is considered that the softer the material, the more the material is worn. In view of the mechanism, the sliding powder is generated by the sliding, and the worn powder enters between the disk and the slider, thereby deteriorating the coefficient of friction and further promoting the wear. Catastrophic phenomena occur. Therefore, it is necessary to select a material that does not damage the disk and has a wear performance that does not cause any problem.

After actually sliding the disk and the negative pressure slider of various hardnesses, the disk rotation fluctuation was measured, and the result is shown in FIG. The vertical axis is based on the fluctuation change of the softest slider. Here, the hardness was measured according to a general Rockwell hardness measurement method as a method for measuring a polymer substance. FIG. 9 shows that a hardness of at least Rockwell M50 is required. In a particularly favorable range, when the hardness is equal to or more than Rockwell M70, there is almost no disc rotation fluctuation.

It was also confirmed that if the upper limit was within the range of the polymer substance, there was no problem of disc scratch.

The material must have good moldability from the viewpoint of mass productivity. Specifically, PC (polycarbonate)
And PPS (polyphenylene sulfide) are preferable.

In addition, if carbon fiber-added plastic is used, the hardness is increased and the conductivity is effective in preventing static electricity.

[0024]

As described above, according to the structure of the present invention, it is possible to obtain stable and stable contact with a magnetic head even with a magnetic disk having variations. A negative pressure slider that does not cause damage can be provided.

Further, since plastic molding is possible, the production of the negative pressure slider with less variation in shape, inexpensive and mass-producible is possible.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a peripheral portion of a negative pressure slider of the present invention.

FIG. 2 is an external perspective view showing a shape example of a negative pressure slider.

FIG. 3 is a diagram showing a relationship between a slider height and a disk rotation load.

FIG. 4 is a view showing a measurement result of a disk rotation fluctuation of a low hardness negative pressure slider;

FIG. 5 is a diagram showing the relationship between the hardness of the negative pressure slider of the present invention and disk rotation fluctuation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Negative pressure slider 1A Step part 1B Convex part 2 Magnetic head 3 Magnetic disk

Claims (1)

(57) [Claims] 1. A negative pressure slider of a magnetic recording / reproducing apparatus for sucking a flexible magnetic disk by a negative pressure generated by rotation and making contact with a magnetic head, wherein the material of the negative pressure slider is plastic. A negative pressure slider, wherein the hardness of the convex portion is not less than Rockwell hardness M50.