JPH08212619A - Magneto-optical storage device - Google Patents

Abstract

(57) Abstract: To improve the signal quality in a magneto-optical storage device using an amorphous magnetic thin film for storage made of an alloy of rare earth and a transition metal. An amorphous magnetic thin film for memory made of an alloy of rare earth and a transition metal is formed on a transparent substrate made of glass or resin, and an ultraviolet curable layer is formed on the amorphous magnetic thin film. A laser beam is incident on the amorphous magnetic thin film through the magneto-optical storage disk through the substrate, and a condensing lens is linked with a focus servo to record, reproduce, and erase information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical storage device capable of recording, reproducing and erasing information by using light.

[0002]

2. Description of the Related Art In recent years, a method of optically storing, reproducing, and erasing information on a magnetic thin film by using a HeNe laser, a semiconductor laser, etc., that is, a magneto-optical recording method has attracted attention, and it has been focused on in the industrial world. R & D has been promoted.

In this system, a gap of about 1 mm can be provided between the recording medium lens and the recording medium. Therefore, by providing a transparent protective plate between the recording medium and the lens. The advantage is that it is possible to reliably prevent dust from directly adhering to the recording medium, and to reduce the influence of dust as compared with the conventional recording method using a magnetic head.

Further, by appropriately changing the thickness of the transparent protective plate, the contact between the lens and the memory disk can be surely prevented, and the head crush which cannot be removed by the conventional method can be completely prevented. is there.

Further, according to this method, the recording bit diameter can be minimized to about the wavelength of light (about 1 μm or less), so that the density can be extremely increased as compared with the conventional magnetic head method. There are also advantages.

[0006]

Although various magnetic materials that can be used in the above-described magneto-optical recording system have been proposed, the present invention is particularly applicable to various magnetic materials such as gadolinium, terbium, dysprosium and holmium. The problem is not solved when an amorphous ferrimagnetic material formed by combining rare earths and transition metals such as iron, cobalt, and nickel in various composition ratios is used as a recording material.

That is, these rare earth-transition metal amorphous ferrimagnetic materials have a drawback that the reproduction signal level is low, and an element structure for enhancing the reproduction performance has been required.

[0008]

In order to solve the above problems, the present invention forms an amorphous magnetic thin film for storage made of an alloy of a rare earth and a transition metal on a transparent substrate made of glass or resin. A laser beam is made incident on the amorphous magnetic thin film through the substrate to a magneto-optical storage disk formed by forming an ultraviolet curing layer on the amorphous magnetic thin film, and a condenser lens is used as a focus servo. The configuration is such that information is recorded, reproduced, and erased in conjunction with each other. Further, in this structure, the thickness of the substrate is preferably about 0.1 mm to 1 mm.

The present invention is intended to improve the signal quality in a magneto-optical storage device using an amorphous magnetic thin film for storage made of an alloy of a rare earth and a transition metal with the above structure.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

FIG. 1 is a side view of a magneto-optical storage disk used in the magneto-optical storage device according to the present invention.

The magneto-optical storage disk shown in FIG. 1 is a glass disk such as a Corning Mycoro sheet or a resin disk 1 such as CR-39, acryl or polycarbonate. By the ion plating method or the like, GdTbFe, GdDyFe, TbDyFe,
The amorphous ferrimagnetic thin film 2 of TbFe, DyFe, GdTbFeNi or the like is formed, and the same material as above is formed on the lower surface of the amorphous ferrimagnetic thin film 2 via an ultraviolet curing adhesive layer 3 such as Fort Bond or Loctite X-853. The glass disk or the resin disk 4 is fixed to form a four-layer structure.

FIG. 2 is a schematic side view showing the relationship between the magneto-optical storage disk and the recording head.

In FIG. 1, a recording head 7 having a condenser lens 5 and a coil 6 for generating a recording / erasing magnetic field above the disk 1 of the magneto-optical storage disk shown in FIG. 1 is linked with a focus servo (not shown). The distance to the amorphous ferrimagnetic thin film 2 can be kept constant when recording, reproducing, and erasing. It should be noted that at the time of reproduction, the coil for generating the magnetic field for recording and reproduction is not used, but the focus servo of the condenser lens 5 is performed.

Since the gap between the recording head 7 and the amorphous ferrimagnetic thin film 2 can be changed by selecting the configuration of the condenser lens 5, the thickness of the transparent disc 1 is set to, for example, 0. It can be freely selected within the range of 1 mm to 1 mm.

The thickness and material of the discs 1 and 4 can be freely selected without departing from the scope of the present invention.

For example, the disc 1 is 0.3 to 0.5 mm.
In the case of using a Corning microsheet with a thickness of 1 to 3, the strength of the magneto-optical storage disk is maintained, so that the disk 4 is 1-3
mm acrylic plate may be used as a stool.

The disk not facing the recording head 7 may be a metal plate such as aluminum or a ceramic plate.

[0019]

As described above, according to the present invention, the laser light is incident on the amorphous magnetic thin film through the transparent substrate on which the film is formed, and the condensing lens is linked with the focus servo to record and reproduce information. Since it is configured to perform erasing, the laser light is irradiated on the amorphous magnetic thin film on the side in contact with the substrate so that it does not easily change over time and is a fresh surface forever, and is composed of an alloy of a rare earth and a transition metal. The reliability of the magneto-optical storage device can be maintained for many years even though a magnetic material, which is extremely susceptible to deterioration, is used.

Further, since the laser light is incident on the amorphous magnetic thin film through the transparent substrate on which the film has been formed, the transparent substrate has the effect of sensitizing the Kerr effect.
Good signal reproduction can be performed.

[Brief description of drawings]

FIG. 1 is a side view of a magneto-optical storage disk according to the present invention.

FIG. 2 is a schematic side view showing the relationship between the magneto-optical storage disk and the storage head of the present invention.

[Explanation of symbols]

 1, 4 disk 2 amorphous ferrimagnetic thin film 3 UV curing agent

Claims (2)

[Claims] 1. An amorphous magnetic thin film for storage made of an alloy of a rare earth and a transition metal is formed on a transparent substrate made of glass or resin, and an ultraviolet curable layer is formed on the amorphous magnetic thin film. A laser having a structure in which laser light is incident on the amorphous magnetic thin film through the magneto-optical storage disk through the substrate and a condensing lens is linked with a focus servo to record, reproduce, or erase information. Optical storage device. 2. The thickness of the substrate is 0.1 mm to 1 mm
The magneto-optical storage device according to claim 1, wherein the magneto-optical storage device is of a degree.