JPH0351782Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a magneto-optical recording disk that can prevent a reduction in recording area and damage to a recording medium due to adhesive extrusion.

Conventionally, magneto-optical recording media in which a magneto-optic thin film is formed on a substrate by vacuum evaporation or sputtering have been subject to problems such as missing information or increased noise due to the influence of dust, scratches, fingerprints, etc. Therefore, a transparent protective disk for protecting the magneto-optic thin film is practically required. This is because dirt, dust, and fingerprints generated on the transparent protective disk can be wiped away without damaging the magneto-optic thin film, and also because the diameter of the incident light beam on the transparent protective disk is smaller than that on the recording surface. On the other hand, it is much larger, but because it is rapidly narrowed down on the recording surface, it has the effect of preventing the SN ratio of the recording medium from decreasing due to holes, dust, fingerprints, etc. that are smaller than a certain size on the transparent protective disk.

However, in the conventional configuration described above, when the transparent protective disk is bonded to the substrate, if the amount of adhesive is large, the adhesive spreads and may reduce the recording area or damage the recording medium. It had the disadvantage that it occurs.

The present invention eliminates the above-mentioned conventional drawbacks, and aims to provide a magneto-optical recording disk that can prevent a reduction in the recording area and damage to the recording medium due to adhesive extrusion.

Means for Solving the Problems In order to achieve the above object, the present invention forms a magneto-optical thin film on a disk with a hole in the center, and attaches a transparent protective disk with a hole in the center to the disk. In a magneto-optical recording disk that is adhered to the magneto-optic thin film side with an adhesive, first and second annular grooves are formed near the inner peripheral edge and near the outer peripheral edge of the disk on which the magneto-optic thin film is formed, and The disc and the transparent protective disc are bonded together using an adhesive applied to the inner peripheral edge of the annular groove and the outer peripheral edge of the second annular groove.

Effect The present invention has the above-described structure, so that the magneto-optical thin film is not contaminated or damaged by the adhesive.
The area of the recording area will not decrease,
Further, the recording area can be clearly defined, adhesion can be ensured, and the total thickness of the two disks can be defined over the entire surface.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a top surface and a cross section of a magneto-optical recording disk according to an embodiment of the present invention.

In Figures 1 and 2, 11 is a hole 12 in the center.
It is a circular plate with annular grooves 13 and 13' provided near the outer circumferential edge and near the inner circumferential edge.
This annular groove is formed within several millimeters from the outer circumferential edge and the inner circumferential edge.

A magneto-optical thin film 14 is formed on the upper surface of the disk 11 by a thin film forming means such as vacuum deposition or sputtering. 15 is a transparent protective disc with a hole 16 formed in the center. 17, 17' are adhesives applied to the outer periphery of the annular groove 13 and the inner periphery of the annular groove 13';
7', the disk 11 and the transparent protection disk 15 are bonded together to form a magneto-optical recording disk 18.

In this way, according to this embodiment, since the annular grooves 13 and 13' are formed in the disc 11, when the disc 11 and the transparent protective disc 15 are bonded together, there is a gap between the disc 11 and the transparent protective disc 15. The adhesives 17, 17' that are about to spread enter the annular grooves 13, 13', and the adhesives 17, 17' do not flow out toward the center of the magneto-optic thin film 14 on the disk 11, and the annular grooves 13 and annular groove 1
The recording area part sandwiching 3' is adhesive 17,1
7' will not be soiled or damaged,
This also prevents the area of the recording area from decreasing.

In addition, especially in this embodiment, since the grooves are formed on the side of the disc on which the magneto-optic thin film is formed, the recording area can be clearly defined, and the recording area can be kept, and management information can be stored on the inner or outer periphery. Vertical information can be recorded. Furthermore, when forming the grooves on the disk side, guide grooves for tracking or blebbing for address information, etc. can be formed, which is advantageous in terms of the manufacturing process. Further, when bonding the disks together, strong pressure can be applied to ensure adhesion, and the total thickness of the two disks can be defined across the front surface.

Effects of the Invention The present invention has the above configuration, and according to the invention, the following excellent effects can be achieved.

(1) The magneto-optical thin film on the disc will not be stained or damaged by the adhesive, and the area of the recording region will not be reduced.

(2) The recording area can be clearly defined, and since especially important information such as management information is generally recorded on the inner or outer circumference, the recording area can be secured.

(3) a guide groove for tracking at the same time as forming an annular groove in the disc forming the magneto-optic thin film;
Alternatively, blebbing of address information etc. can be formed.

(4) When bonding two disks, there is no risk of the adhesive entering the recording area, so strong pressure can be applied to ensure bonding, and at the same time, the total thickness of the two disks can be completely covered. Can be specified across the board.

[Brief explanation of drawings]

FIG. 1 is a top view of a magneto-optical recording disk according to an embodiment of the present invention, and FIG. 2 is a sectional view thereof. 11... Disk, 12... Hole, 13, 13'...
Annular groove, 14... magneto-optical thin film, 15... transparent protective disk, 16... hole, 17, 17'... adhesive,
18...Magneto-optical recording disk.

Claims (1)

[Scope of utility model registration request] In a magneto-optical recording disk, a magneto-optical thin film is formed on a disk with a hole in the center, and a transparent protective disk with a hole in the center is bonded to the magneto-optic thin film side of the disk with an adhesive. , first and second annular grooves are formed near the inner circumferential edge and near the outer circumferential edge of the disc on which the magneto-optic thin film is formed, and the inner circumferential edge side of the first annular groove and the outer circumference of the second annular groove are formed. A magneto-optical recording disk formed by adhering the disk and the transparent protective disk using an adhesive applied to the edge.