JPS6089848A - Information recording method - Google Patents

Abstract

PURPOSE:To obtain an information recording system possible for simple recording and erasure by forming locally plural ditches on the surface layer of an alloy having a memory recording effect to record the information and heating the surface layer to erase the information. CONSTITUTION:The thin strip surface layer 7 made of an alloy having a memory recording effect is deformed by a rod-shape stylus 8 to form a circular ditch 9 and record the information. The thin strip surface layer 7 is heated (nearly 100 deg.C) and the ditch 9 is restored to erase the information. Thus, the information recording system having the capacity of simple recording and erasure is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an information recording method that makes it possible to write and erase information using an alloy having a shape memory effect.

(Conventional structure and its problems) Conventionally, typical recording media used for recording information are:
There are magnetic recording media. This is a layer of magnetic material such as r-Fe2O3 formed on a tape or disc-shaped polyethylene terephthalate base material. By applying a magnetic field from the outside and locally magnetizing this magnetic layer, a small magnet is created. This is to record various information as signals on a recording medium. These magnetic recording media are widely used in various fields as recording media for audio, video, and computers. However, this information recording method has the following problems. That is, since recording is performed by magnetization, when a magnetic field is applied to this medium from the outside, the stored recording changes or disappears. For this reason, magnetic recording media must be protected from being affected by other magnetic fields, but it is considered impossible to use them without being affected by these magnetic fields at all. Information distribution media and methods will need to be provided. In order to meet these requirements, there are recording methods that do not use magnetism and record through holes in the tape or card, and recording methods that make the surface layer of the recording medium locally amorphous or crystalline. Methods have also been developed to do this, but the former has the disadvantage that it is easy to record but cannot be erased, while the latter requires extremely complicated means such as using a laser beam for both recording and erasing.
There is a problem that the system itself is 4AtM and expensive.

(Objective of the Invention) In order to solve all of the above-mentioned problems, the present invention aims to provide a new information recording method that can easily record and erase the record easily. It is something to do.

(Structure of the Invention) The present invention records information by locally creating a plurality of depressions in the interface layer of an alloy having a shape memory effect, and by heating the surface layer. This method is characterized in that the recorded information is erased by restoring the soaked portion to its original shape.

An alloy having a shape memory effect is an alloy that has the property of forming the alloy into a diamond shape at a certain temperature and then immediately restoring the shape before the deformation by simply heating the diamond by a few 10'Ci degrees above that temperature.

Such an alloy is Ag-Cd.

Au-Cd, Cu-AL-Ni, Cu-
Au-Zn, Cu-8n, Cu-Zn,
Cu-Zn-X (X=Si, Sn, At
.

Ga), In-TL, Ni-AA, T
i-NI, Fe-Pt.

A large number of alloys such as Fe-Pd and Xvin-Cu are known, and the shape memory effect characteristics vary depending on the type, composition, and manufacturing method of these alloys.

(Explanation of Examples) The structure of the present invention will be explained in detail below with reference to Examples.

Example 1 FIG. 1 is an explanatory diagram of a method for producing an alloy having a shape memory effect used in the present invention by a liquid quenching method.

It has a diameter of 30 tyr and rotates at 1700 mutter/min.
"so T150 (numbers are atoms) and -
cent), the entire area of the molten metal 3 is approximated to the rotating roll 1 by i
It was maintained at 1430° C. in a quartz-faced, 14-sided diagonal 5 with a nozzle opening 4 of 5 +11 m x 0.3 vm on 1 and j. The surface of this molten metal is pressurized at 0.5 kg/an2,
The molten metal is spouted from the nozzle port 4 onto the rotating roll, and the width is 51.
1II++1 A continuous ribbon 6 of N15o T15[1 with a thickness of 50 μm was obtained. This was hot rolled to a thickness of 35 μm,
The surface was smoothed.

FIG. 2 is a trunk view, not showing the recording medium of Example 1 used in the present invention, and 7 is a temperate surface layer formed by the method shown in FIG. 1. This thin strip surface layer 7 is deformed by a rod 18, and information is recorded by a circular depression 9 with a diameter of 0.5 to 3 μm and a depth of 5 to 10 μm. This recorded ('
The N number can be read by the difference in intensity of light reflection.
Because of this busyness, he can easily transform into 11L Kii No. 0. In addition, in order to erase this record, if the band temperature is raised to 100° C., the depressions will disappear and the original plane will return. This record
Even after 105 erasing cycles, there was almost no change in the light reflectance or in the rear direction of the surface recording depressions.

Embodiment 2 FIG. 3 is a perspective view showing the recording medium of Embodiment 2 used in the present invention.
zn1. (Numbers are atoms) and 2 of the same composition.
A thin film 11 having a thickness of μm was formed. The surface of this thin film 11 was coated in an elliptical shape with a long side of 0.5 μm, a short side of 0.3 μm, and a floor height of 0.2 μm by the same method as in Example 1 shown in FIG. J
Several depressions 9 are formed to record information.

In addition, in order to erase this record, the stainless steel substrate 10
By passing an electric current through the substrate, the substrate is heated, and this heat causes the depressions 9 to disappear, resulting in a flat surface and no recording. After performing this recording/erasing cycle 104 times, there was almost no change in the reflectance of light or the direction of the surface recording depressions.

Embodiment 3 FIG. 4 is a diagram showing a recording medium according to Embodiment 3 used in the present invention.
(The numbers are atomic percent) were vaporized to form a 5 μm thick thin film 13 having the same composition. A circular shape with a diameter of 04 μm and a depth of 01 μm is formed on the narrow side of this thin J pattern 13 as in Example 2.
The entire depression 9 is formed, thereby recording ¥1 shi. In order to erase this information, the recess 9 is irradiated with laser light 4 to erase the recess 9 and return it to its original flat surface. Even after performing this iL2 recording/erasing cycle 10' times, there was almost no change in the light reflectance or the rear side of the surface recording blur.

As described above, if an alloy having a shape memory effect is produced by a so-called direct thin body forming method such as a liquid quenching method, a starburst method, or a steam bath method, fine crystal grains (grain size 1
0 μm or less) can be easily formed. Since the crystal grains of these thin bodies are fine (several 10X to 10 μm), even if they are repeatedly recorded by deformation and erased by heating, the thin bodies produced by the normal alloy processing method will still retain the same amount of data as shown in Figure 5. It becomes comparatively soft and grain boundary fracture occurs, making it possible to use it repeatedly. This direct thin body forming method includes chemical plating, chemical vapor deposition (CVD), and the like, and the same effects as n1 described above can be expected.

Fig. 5 shows a recording medium manufactured by the direct thin body forming method of Example 2 shown in Fig. 3, and a so-called normal recording medium made from an ingot but having the same composition but through processes such as hot rolling. This figure shows a comparison of the changes in tensile strength due to recording/erasing cycles with a recording medium produced by the conventional method. It is also shown that the product made by the direct thin body forming method according to Example 2 has better durability.

The above explanation has been about the Ni-Ti system, Cu-AA-Zn system, and Cu-Sn system, but there are also other systems such as In
A similar effect can be expected for alloy systems having shape memory effects such as -Tl series, N1-AA series, and Cu-Mn series. Furthermore, recording media made of these alloys by a so-called direct thin body forming method such as a liquid quenching method, a suction method, or a vapor deposition method have extremely excellent durability.

(Effects of the Invention) As explained above, the present invention locally deforms a recording medium and causes a plurality of bulges caused by the local deformation.
Since the 7'f information is recorded, even if a magnetic field is applied from the outside, the recording will not be erased, and the information 11y is magnetically stable and can be reliably recorded and erased. Cabinet,
Since these recordings and their erasing are performed by extremely simple means of plastic deformation and heating, it is possible to greatly simplify the recording and erasing processes and to reduce costs accordingly.

Furthermore, recording and erasing thereof can be done locally or globally instantaneously. That is, to remove records, it is possible to make inlets locally one after another using something like a copper bar, or it is possible to instantly record information across the entire surface using a mold. Regarding erasing, it is possible to erase locally with a laser beam, and it is also possible to erase all records by heating the entire surface. A recording medium having such unprecedented characteristics is expected to provide a system that does not interfere with recording and erasing information.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the case where the alloy having a shape memory effect used in the present invention is manufactured by the liquid quenching method, Figures 2 and 3
4 and 4 are perspective views showing recording media of Examples 1, 2, and 3 used in the present invention, and FIG. 5 shows recording media produced by the direct thin body forming method and those produced by the conventional method FIG. 3 is a characteristic diagram comparing tensile strength changes with a recording medium due to recording/erasing cycles. 1... Rotating roll, 2... High frequency heating coil, 3...
...Molten metal, 4...Nozzle opening, 5...Molten metal reservoir,
6... Continuous ribbon, 7... Thin strip surface layer, 8... Rod-shaped copper, 9... Keimi, 10... Stainless steel substrate, 11
, 13... m film, 12... flat glass substrate, 14...
...Laser light. Patent applicant: Matsushita Electric Industrial Co., Ltd. Agent: Hisashi Hoshino Figure 1 Figure 3

Claims (2)

[Claims] (1) Information is recorded by locally creating a plurality of depressions in the surface layer of an alloy having a shape memory effect, and
An information recording method characterized in that the recorded information is erased by heating the surface layer to restore the thigh portion to its original shape. (2) Alloys with shape memory effect are processed by liquid quenching method,
An information recording method according to claim (1), characterized in that the information recording method is produced by a direct thin body forming method such as a drip method or a vapor deposition method.