JPH01119901A - Reading and writing method for magnetic storage medium - Google Patents

Abstract

PURPOSE:To attain the storage of high speed and high density by generating a superconductive film on the surface of a magnetic substance, projecting laser beams on a magnetic storage body in which an influence from an external magnetic field is removed, raising the irradiated part of the superconductive film more than a critical temperature, and permitting a magnetic head to read and write magnetic information into the magnetic substance in the irradiated part. CONSTITUTION:When the superconductive film 2 is spot-irradiated by the laser beams 4 and the superconductive film 2 is raised to more than the critical temperature Tc, the minor effect of the irradiated part 5 is removed, whereby magnetic information can be read from and written into the magnetic substance 1 in the irradiated part 5 by the magnetic head 6. At that time, the laser beams 4 can easily stop a spot in a lens. Thus, the density of energy in the spot can be enlarged and the recording of high speed and high density is attained.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for reading and writing magnetic information on a magnetic storage medium such as a floppy disk or a hard disk. By creating a film, the Meissner effect blocks external magnetic fields and protects the magnetic information written on the magnetic storage medium.

(Prior Art) Currently, storage media using magnetic materials, such as floppy disks and hard disks, are used as auxiliary storage media for commonly used computers and their application products. In order to increase the storage density of this storage medium, efforts have been made to make the magnetic material finer and more uniform. Efforts have also been made to miniaturize the magnetic storage head and achieve accurate track tracing.

However, on the other hand, magnetic storage media have the disadvantage that the stored contents are destroyed by external magnetic fields, and conventional floppy disks are completely defenseless against external magnetic fields (for example, by bringing a magnet close to them). Hard disks also have problems such as destruction due to strong external magnetic fields and residual magnetism in the head when the power is turned off.

No technology has yet been developed that can completely solve these problems, and although conventional check mechanisms have already been put into practical use to detect when memory contents have been destroyed, no technology has been developed to properly restore the contents. Not yet.

Therefore, the present applicant has previously developed a magnetic storage medium in which the surface of the magnetic disk is covered with a superconductor, thereby making it possible to protect the FB memory contents through the Meissner effect.

(Problems with the Prior Art) However, the previously developed magnetic storage medium had a drawback in that it was inconvenient to read and write after being coated with an a-conductor. Also high speed, high 'I1. There were also problems with memory.

(Objective of the Invention) The object of the present invention is to solve the problem described in item E, to cancel the Meissner effect only in the part necessary for reading and writing, so that only that part can be read by a magnetic head, and to make it possible to read only the part necessary for reading and writing. remains protected from external magnetic fields, and at high speeds,
Takayen: The purpose is to realize a reading method that can be memorized at once.

(Means for Solving the Problems) The present invention is based on J41v4, as shown in FIG. As shown in the figure, the irradiated portion 5 of the superconductor film 2 is heated to a critical temperature or higher by spot irradiation with a laser beam 4, and magnetic information can be read and written to the magnetic material l using the magnetic head 6 in the irradiated portion 5. This is a method for reading and writing magnetic storage media.

(Effect) 2nd V! J is an explanatory diagram of the reading and writing method of the present invention. Usually, there is a superconductor film 2 on the surface of the magnetic storage medium 3.
Although it is not possible to read or write to a magnetic material l using an external magnetic field, in the present invention, this superconductor WJ2
When the superconductor film 2 is heated to a temperature higher than the critical temperature Tc by spot irradiation with a laser beam 4, the Meissner effect in the irradiated portion 5 is canceled, so that magnetic information is transferred to the magnetic body 1 in the irradiated portion 5 by the magnetic head 6. You can read and write S.

(Example) FIG. 1 shows a magnetic storage medium 3 in which the magnetic material 1 is coated only on one side of the base film 7, and FIG. 3 shows the base film 7.
This is a magnetic storage medium 3 in which a magnetic material 1 is coated on both sides. The magnetic storage medium 3 shown in FIG.

In the first to FIG. 3, reference numeral 1 is a magnetic material such as a metal or gold m oxide, 2 is a superconductor made of an oxide superconductor, and 7 is a base film made of a molecular film such as polyester.

The a conductor M2 has an external magnetic field W of 11 due to the Meissner effect! It is desirable that the thickness be such that it can protect the magnetic information stored in the magnetic storage medium 3 from external magnetic fields, and that the temperature can rise in a short time when irradiated with a laser beam.

The spot of the laser beam 4 in the present invention can be easily narrowed down using a plastic lens, and the energy density within the spot can also be increased. Reducing the spot diameter enables high-density recording 6 The wavelength of the laser used in the present invention is preferably set in a range that is easily absorbed by the superconductor.

For the optical system, conventional technology used in laser discs, compact discs, etc. can be applied.

Note that the substrate is sufficiently thick compared to the superconductor film 2, so that the laser beam can be transmitted through the ji! If it is cut off, heat will diffuse in a short time and the superconductor film 2 will become low temperature.

(Effect of the invention) The read/write method of the present invention has the following various effects.

A. Even a magnetic disk in which the surface of the magnetic material 1 is coated with the superconductor film 2 can be easily read and written from the outside.

B. Since the spot irradiation with laser makes only the reading and writing parts normal conductive, the other parts remain protected from the external magnetic field by the Meissner effect of the superconductor film 2, and when reading and writing, data is not written to other parts. The magnetic information contained therein will not be destroyed.

C. Narrow down the laser beam to make the spot diameter smaller (this will increase the energy density within the spot, making high-speed, high-density recording possible.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a magnetic disk, FIG. 2 is a cross-sectional explanatory view of the reading/writing method of the present invention, and FIG. 3 is a cross-sectional view of a magnetic disk that can be read and written on both sides. l is the magnetic material 2 is the superconducting film 3 is the magnetic notation tl! The medium 4 is the laser beam 5 and the irradiated part 6 is the magnetic head.

Claims (1)

[Claims] A laser beam 4 is spot irradiated onto the magnetic memory 3, which is freed from the influence of external magnetic fields by forming a superconductor film 2 on the surface of the magnetic material 1, and the irradiated portion 5 of the superconductor film 2 is heated to a temperature higher than the critical temperature. A method for reading and writing a magnetic storage medium, characterized in that magnetic information can be read and written to a magnetic body 1 using a magnetic head 6 in the irradiated portion 5.