JPH0264911A - Magnetic storage medium and its manufacturing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic storage medium and a method for manufacturing the same, and more specifically, a magnetic scale for a V11 gas sensor, a memory for detecting the expansion/contraction position of a pressure cylinder rond, etc. A magnetic storage medium using a precipitation hardening magnetic material, suitable for use as a storage medium dedicated to a measured object or a ROM for a computer, etc., and in which stored information is not easily erased, that is. The present invention relates to a magnetic storage medium in which existing stored data is not easily destroyed, and a method for manufacturing the same.

[Conventional technology]

Conventional magnetic storage media include ``magnetic powder binders on tape or disk-shaped bases for freely writing and reading using a magnetic head, and ``recording and reading'' using a laser. There are devices for optical recording to freely carry out operations, magnetic scales for magnetic sensors, and memories for detecting the expansion and contraction positions of pressure cylinder ronds. The structure of pit storage in these magnetic storage media will be explained with reference to an example of a magnetic storage medium made of a precipitation hardening type magnet material shown in FIG. 5 (FIG. 5).

FIG. 1 shows a magnetic storage medium made of precipitation hardening magnetic material, which includes a magnetic part IA and a magnetized part IC (that is, a magnetized part IC).

The magnetized part IC is a part of the magnetic part IA that is magnetized at a predetermined position), and the presence or absence of this magnetized part IC forms a pit memory. Therefore, the process of forming and using the PID memory will be explained next with reference to two drawings (FIG. 6). Figure (a) shows a state in which all parts of the magnetic storage medium 1 are still magnetic parts 1A, but as shown in Figure (b), this magnetic storage medium 1 is moved to a predetermined position by the magnetic head 3. A magnetized part IC is formed on the existing magnetized part IC.
is erased and written to the PID memory. On the other hand, for reading the pit memory, the magnetized part I at a predetermined position
The presence or absence of C is detected, and if it is "present", "1" is read out from the pit memory, and if "absent", "0" is read from the pit memory.

[Problem to be solved by the invention]

However, such conventional magnetic storage media.

If this magnetic storage medium is influenced by an external magnetic field that is larger than its inherent coercive force, the unmagnetized portion (i.e., the magnetic portion IA in Figure 5) will become magnetized, and the existing memory will be easily destroyed. The disadvantage is that it can be done.

The present invention focuses on the problems of conventional magnetic storage media, and aims to provide a magnetic storage medium in which once stored information is not easily erased, that is, existing stored data is not easily destroyed, and a method for manufacturing the same. .

[Means to accomplish the task]

To achieve the above object, the magnetic storage medium according to claim 1 of the present invention is described with reference to FIG.
This is a configuration including B and two magnetized part ICs. Either the non-magnetic part IB or the magnetized part IC may be used as the pit memory.

The manufacturing method according to claim 2 of this magnetic storage medium will be explained based on FIG.
A first step (FIG. 6(b)) of forming B and a second step of magnetizing another part IA of the non-magnetic part IB to form a magnetized part 1C.
The structure consisted of a step ((C) in the same figure). Furthermore, the manufacturing method according to claim 3 is explained based on FIG. 2, in which the two manufacturing steps of claim 2 are reversed, that is, first, the entire precipitation hardening magnet material 1 is magnetized, and then The first step is to form a hardening magnet IC (FIG. 2(b)), and the second step is to heat-treat a desired portion of the precipitation hardening magnet to form a non-magnetic portion IB (FIG. 2(B)). C)).

[Effect]

According to the configuration of such a magnetic storage medium, since a non-magnetic part is used, even if an external magnetic field is applied, this non-magnetic part cannot be magnetized.In other words, once stored information is easily erased. I don't get it.

In other words, it can be a magnetic storage medium in which existing stored data is not easily destroyed. In this sense, the magnetic storage medium of the present invention can be said to be an absolute storage medium, that is, a read-only magnetic storage medium. And what is used as a pit storage for such magnetic storage media?

Since the non-magnetic part IB and the magnetized part IC are in a relative relationship,
Either one can be used as a pit memory.

Next, the effects of the method of manufacturing a magnetic storage medium, particularly the method of manufacturing a non-magnetic portion, will be described below. The so-called alnico magnet (F
Al4.e mainly. The magnetic properties of precipitation-hardened magnets, such as magnets containing Ni and Co) and iron-chromium-cobalt lithite (Fe-Cr-Co magnets: magnets containing mainly Fe and Cr and Co), are determined by heat treatment in a magnetic field. Therefore, it is made by precipitating particles with -axis magnetic anisotropy by spinodal decomposition (two-layer separation) with anisotropy. Therefore, in the present invention. To make a desired part of a magnetic precipitation-hardened magnet non-magnetic, it is sufficient to heat-treat the desired part again without applying a magnetic field atmosphere. Similarly, to make a desired region non-magnetic, the desired region may be heat-treated without applying a magnetic field atmosphere. In other words, the purpose of this heat treatment is to destroy or eliminate the anisotropy in the desired region, and by performing a heat treatment such as rapid heating, rapid cooling, melting, or annealing, and then a cooling process such as annealing. Secondary precipitation can be suppressed and desired non-magnetic sites can be formed. In addition, "non-magnetic (or non-magnetic portion)" stated in the claims and other areas
” is not a realistic expression, strictly speaking, so this is “
It is described as "a region where the magnetic properties have significantly decreased or deteriorated."

(Example) The present invention will be described in detail below with reference to the drawings (Figs. 1 to 4). Fig. 1 is a diagram showing a magnetic storage medium according to claim 1, and Fig. 2 is a diagram showing a magnetic storage medium according to claim 2. FIG. 3 is a diagram illustrating a method for manufacturing a magnetic storage medium according to claim 3, and FIG. 4 is a diagram illustrating a method for manufacturing a magnetic storage medium according to claim 3. FIG. In Fig. 1, 1 is a precipitation-hardened magnet material for iron/chromium/cobalt magnets (width 5 mm x thickness 10 mm x length 80 m).
m), which shows a non-magnetic part IB and a magnetized part IC (this magnetized part 1C is a so-called iron-chromium-cobalt magnet). If either one is used, it becomes a complete magnetic storage medium in use. The embodiment of claim 2 shown in FIG.
x Thickness 10mm x Length 80mm) 1.
)), then using laser 2A (2 is the laser source),
The desired area is approximately 700 mm deep from the surface to a depth of 2 to 3 mm.
After heating at °C, the first step is to temper this part to form the non-magnetic part IB (Figure (b)).Then, the entire precipitation-hardened magnet material l is coated with a B-H tracer. The above-mentioned magnetic storage medium is manufactured by applying a magnetic field in the thickness direction to form a magnetized portion IC (FIG. 4(c)).

Incidentally, even though the entire precipitation hardening magnet material 1 is magnetized in the second step, it is natural that the non-magnetic portion IB produced in the first step is not magnetized, and this is the gist of the present invention. It is.

The embodiment of claim 3 in FIG.
1 (length 80 mm) is prepared (see figure (a)), the entire precipitation hardened magnet material 1 is magnetized by applying a magnetic field in the thickness direction using a B-H tracer to form an iron-chromium-cobalt magnet. The first step is performed ((b) in the same figure). Then, use laser 2A to move this magnet to a desired area 2 to 3 times from the surface.
After heating to a depth of up to 1.0 mm at about 700'C, a second step is carried out to temper this and make this part into a non-magnetic part IB (FIG. 4(c)) to produce an optical storage medium. Therefore, the effects of these embodiments will be explained with reference to FIG. 4, which shows the following:
The generated voltage, that is, the magnetic field strength of the magnetic storage medium manufactured according to claim 3 was evaluated using a Hall element,
As shown in the figure, a voltage is generated in the two magnetized parts IC, and no voltage is generated in the non-magnetic part IB, that is, it is clear that the non-magnetic part IB is not magnetized. A magnetic storage medium suitable for measuring objects such as a magnetic scale for a magnetic sensor or a memory for detecting the expansion/contraction position of a rod of a pressure cylinder, a storage medium dedicated to a ROM for a computer, or an absolute recording medium such as an encoder. It can be seen that a manufacturing method thereof can be provided.

〔Effect of the invention〕

As explained above, according to the magnetic storage medium according to the present invention, once stored information is not easily erased, that is, existing stored data is not easily destroyed. Furthermore, this magnetic storage medium can be processed using relatively easy-to-handle equipment such as lasers.

Moreover, it can be manufactured by an easy manufacturing method that requires only two steps.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a magnetic storage medium according to claim 1, and FIG.
The figure is a diagram illustrating a method for manufacturing a magnetic storage medium according to claim 2,
3 is a diagram for explaining the manufacturing method of the magnetic storage medium according to claim 3, FIG. 4 is a diagram for explaining the effect of the magnetic storage medium according to claim 1 manufactured by the manufacturing method according to claim 3, and FIG. FIG. 6 is a diagram illustrating a conventional magnetic storage medium manufacturing method. 1... Precipitation hardening magnet material IA... Magnetic part 1B... Non-magnetic part IC... Magnetized part 2... Laser source 2A... Laser 3... Magnetic head

Claims (3)

[Claims] (1) A magnetic storage medium made of a precipitation hardening magnetic material, characterized by a structure consisting of a non-magnetic part and a magnetized part. (2) (a) A first step in which a desired portion of the precipitation hardening magnet material is heat treated to form a non-magnetic portion. (b) A second step of magnetizing other parts of the non-magnetic portion. A method for manufacturing a magnetic storage medium, characterized in that the magnetic storage medium according to claim 1 is manufactured through the above steps. (3) (a) The first step to magnetize the entire precipitation hardening magnet material
Process. (b) A second step of heat-treating a desired portion of the precipitation hardening magnet to make this portion a non-magnetic portion. A method for manufacturing a magnetic storage medium, characterized in that the magnetic storage medium according to claim 1 is manufactured through the above steps.