JPS5885933A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To keep the output of reproduction at a certain level, by decreasing the thickness of a magnetic film toward its outer circumference. CONSTITUTION:A magnetic material or gamma-Fe2O3 is coated along with a binder on a single side or both sides of a substrate 2 made of an aluminum alloy, etc. and having an attachment hole at the center part toward the radius direction of the substrate and with the thickness decreasing toward the outer circumference of the magnetic material. Otherwise a magnetic film 3A is formed on the substrate 2 by a sputtering or vapor depositing process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording medium such as a magnetic disk used in a magnetic disk storage device among magnetic storage devices.

Figures 1 and 2 are a plan view and a cross-sectional view of a conventional magnetic disk, where (1) shows a magnetic recording medium such as a magnetic disk;
(2) is made of aluminum alloy or the like into a disk shape, with a mounting hole (4) formed in the center for insertion into the spindle of the storage device.
2) is a magnetic film formed to a uniform thickness on both sides of the magnetic film (3), for example, rFe! A magnetic material such as O1 is coated on both sides of the substrate (2) together with a binder, and recently, in order to improve the recording density, a magnetic material rFence is formed by sputtering or vapor deposition, and CO (cobalt) is coated on both sides of the substrate (2). It has also been practiced to form magnetic materials of this type by plating. (5) is the center of rotation of the magnetic recording medium (1), rrtJ and "r2" are the minimum radius dimension and maximum diameter dimension of the range used for recording information on the magnetic film (3).

The conventional magnetic recording medium (1) configured as described above is
For recording or reproducing, a magnetic head (not shown) of the magnetic storage device is arranged to face K=and,
In the case of recording, the magnetic film (3) is magnetized by the leakage magnetic field in the gap part of the core of the magnetic head, and in the case of reproduction, the magnetic film (3) of the magnetic recording medium (1) rotating at high speed is performed. This is done by detecting the signal magnetic field from 3) as an induced voltage due to changes in magnetic flux entering the core of the magnetic field head. As mentioned above, the magnitude of the reproduction output detected as an induced voltage is determined by the magnetic head, the magnetic recording medium (l), that is, the magnetic disk, and their mutual relationship. Among these factors, the magnetic The relative speed between the recording medium (1) and the magnetic head is one of the factors that affects the magnitude of the reproduction output, and as mentioned above, the principle of reproduction by the magnetic head is a response to changes in magnetic flux. It goes without saying that the magnitude of the reproduction output is proportional to the amount of change in magnetic flux per unit time, that is, the moving speed of the magnetic recording medium (1).

Therefore, the conventional magnetic disk in this type of magnetic disk storage device, that is, the disk-shaped magnetic recording medium (1)
As shown in Figure 2, this magnetic recording medium rotates around the center of rotation, and the magnetic films (3) (3) on both sides are formed to have a uniform thickness. The moving speed of (1) and the reproduction output are proportional to the radial dimension from the rotation center (5), and the larger the radius, the greater the reproduction output. However, there is a drawback that a difference occurs in the reproduction output, and a correction function for the reproduction output is required.6 This invention was made with attention to this point, and the present invention has been made by focusing on this point. The thickness of the film is gradually changed in the radial direction of the substrate toward the outer circumference, so that the reproduction output can always be kept constant even if the radial position of the magnetic head corresponding to this magnetic film changes. The purpose of the present invention is to provide a magnetic recording medium that has the following characteristics.

That is, FIGS. 3 to 5 show one embodiment of the invention of the above-mentioned invention, and the same reference numerals as those of the above-mentioned conventional ones (Fig. 1 and 2) refer to the same constituent members and their explanations. omitted.

First, in Fang 3 and Fang 4, (I A )Fi
A magnetic recording medium such as a magnetic disk related to this S, a disc-shaped substrate (2
) are formed with conical magnetic films (3) (3) whose thickness decreases in the radial direction toward the outer circumference. This conical magnetic film (3) has a K? - It is formed by co-coating a magnetic material such as FemOs with a binder, or by sputtering, sputtering, or vapor deposition.

Furthermore, the shape of the conical magnetic film (3) is as shown in FIG.
The film thickness of the conical magnetic film (3) at rts
It is constructed so that the relationship of Q, 7 (goose/l!) ≠ r17r snow is maintained, assuming J and "t!". In addition, the above film thickness rtI
J, rt, and J are approximately 0.1 to 0.6μ grooves.

As described above, the conical magnetic film (3) according to the present invention
The reason for setting the form (3) as above is that, in general, the thickness of the magnetic film in this type of magnetic recording medium is 2rt'', and the reproduction output rEJ is E;'kt.
The relationship tα7 is known, and the reproduction output rEJ is related to the moving speed of the magnetic film (3), and the output at the radial dimension frJVC from the center of rotation is In summary, the playback output rEJ
teeth.

It can appear as Ezk-r-tα7. Therefore, in one embodiment of the present invention, α7 (h/lx): r1/r atmosphere, te, rt(1
7 (Since it is kept constant, the reproduction output can always be kept constant regardless of the radius dimension "r".

As described above, the present invention is characterized in that the thickness of the magnetic film formed on the disk-shaped substrate (2) is thinly magnetized in the radial direction of the substrate (2) toward the outer circumference, and the conical magnetic film ( 3A), this conical magnetic film (3A) [shows that the output can always be kept constant even if the radial position of the corresponding magnetic head changes.

However, it has an excellent effect that does not require a regenerative output regeneration function circuit as in the conventional case.

In addition to the above-mentioned embodiment, conical magnetic 3A)i,
Although we have described the case in which the film is formed by reducing the film thickness tP, it is unlikely that the same effect can be obtained even if the film is tilted in the shape of a magnetic cone with a uniform thickness.

[Brief explanation of drawings]

1 and 2 both show a conventional magnetic recording medium, with FIG. 1 being a plan view and FIG. 2 being a sectional view taken along the line 1(1)-(1). Figures 3 to 3 all show one embodiment of the present invention, so the figure is a plan view, Figure 4 is a sectional view at (PI')-(*) in Figure 3, and Figure 5 is a conical shape. FIG. 2 is a configuration diagram of a magnetic film. In the figure, (1) is a magnetic storage medium, (2) is a substrate, 1) is a conical magnetic film, (4) is a mounting hole, (5) is a rotating hole, and the same symbols in the figure are the same. −I Acted as an agent for the equivalent portion of nine companies.
Nobuo Nobu - Figure 1 Figure 3

Claims (2)

[Claims] (1) A magnetic recording medium characterized in that the thickness of the magnetic film formed on the surface of a disc-shaped substrate is tapered in the radial direction of the substrate toward the outer circumference to form a conical magnetic film. (2) R Fe spirit Os on 10,000 faces or both sides of the board
A conical (3) substrate with a diagonal hole in the center is made of aluminum by coating a magnetic material with a binder, or by sputtering or vapor deposition.