JP2551995B2 - Optical memory device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an optical memory element, and more particularly to an optical memory element having a protective substrate attached by an adhesive.

[Prior Art] Conventionally, as an optical memory device, a read-only memory,
Additional recordable memory and rewritable memory are known. FIG. 10 shows an example of the rewritable optical memory element.

That is, in this rewritable optical memory device, the magnetic recording film 2 is formed on the front surface of the substrate 1 having a light transmitting property, and the protective substrate 4 is adhered to the back surface side of the magnetic recording film 2 via the adhesive layer 3. Is configured.

[Problems to be Solved by the Invention]

However, in the above-mentioned optical memory device, when the substrate 1 and the protective substrate 4 are bonded by the adhesive layer 3, there is a problem that bubbles 5, 5, ... Are generated in the adhesive layer 3. In particular, when the bubbles 5, 5 generated in this manner are in contact with the magnetic recording film 2, when the magnetic recording film 2 is irradiated with a laser beam to be heated and magnetically recorded, the bubbles 5. Since the thermal conductivity of the portion 5 is worse than that of the adhesive layer 3, the magnetic recording film 2
In the area facing the bubbles 5, 5, and the area facing the adhesive layer 3, the recording bit size varies, and the signal characteristics deteriorate.

Also, if the bubbles 5.5 are in contact with the outside air, the bubbles 5.5
There is also a problem that the magnetic recording film 2 is deteriorated from the portion of.

Although the single-sided recording type optical memory element has been described above, as shown in FIG. 11, two substrates 6 and 6 on which the magnetic recording films 7 and 7 are formed respectively are bonded via the adhesive layer 8. Also in the double-sided recording type optical memory element, the same problem as in the single-sided recording type optical memory element occurs due to the generation of the bubbles 9 in the adhesive layer 8.

Although it is conceivable to remove the air bubbles 5.5, ..., 9 ... in the adhesive layer 3/8 by means such as vacuuming,
In that case, there is a problem that the work becomes extremely complicated.

[Means for solving the problem]

In order to solve the above problems, an optical memory element according to the present invention is an optical memory element in which a magnetic recording film is formed on a substrate and a protective substrate is bonded onto the magnetic recording film via an adhesive layer. , The protective substrate, a plurality of holes extending in the thickness direction of the protective substrate to communicate the adhesive layer and the outside air,
It is characterized in that a plurality of grooves are formed on the adhesive layer side and extend radially from the center of the protective substrate, and the outer peripheral edge thereof communicates with the outside air.

[Work]

According to the above configuration, since a plurality of holes extending in the thickness direction of the protective substrate and a plurality of radially extending grooves are formed in the protective substrate as a passage that connects the adhesive layer and the outside air, the protective substrate is formed. Bubbles generated in the adhesive layer when the substrates are bonded are released to the outside through the plurality of holes and grooves, and the possibility that the bubbles remain in the adhesive layer is reduced.

[Embodiment 1] The following will describe one embodiment of the present invention with reference to FIGS. 1 to 3.

As shown in FIGS. 1 and 2, the optical memory device 10 is
Translucent substrate 11 and magnetic recording film 12 formed on substrate 11.
It has and. The magnetic recording film 12 has an easy axis of magnetization in a direction perpendicular to the film surface.

A protective substrate 14 is provided on the magnetic recording film 12 via an adhesive layer 13.
Are glued together. The protective substrate 14 extends in the thickness direction thereof and has a plurality of holes 15, 15 ... As passages for communicating the adhesive layer 13 with the outside air, and the protective substrate 14 flows out from the adhesive layer 13 into the holes 15, 15. The adhesives 13a, 13a ... Are filled.

In this optical memory device 10, as is well known, the substrate
Recording and erasing are performed by irradiating the magnetic recording film 12 with a laser beam through 11 and applying a magnetic field while raising the temperature. By irradiating the magnetic recording film 12 with laser light through the substrate 11, information can be reproduced by utilizing the magneto-optical effect.

 Hereinafter, a manufacturing procedure of the above optical memory device 10 will be described.

First, as shown in FIG. 3 (a), a magnetic recording film 12 having a predetermined thickness is formed on a substrate 11 made of glass or translucent resin by vapor deposition, sputtering or the like, and then the magnetic recording film 12 is continuously formed. Then, for example, an adhesive made of an ultraviolet curable resin, a thermosetting resin or the like is applied to form the adhesive layer 13.

Next, as shown in FIG. 3B, a protective substrate 14 is placed on the adhesive layer 13 and pressed downward. Then, the adhesive layer
If there are air bubbles 16 ・ 16 in 13 ...
16 ... As shown in FIG. 3 (c), the holes 15 of the protective substrate 14
・ It is released to the outside through 15…. Further, some of the adhesives 13a, 13a, ... Of the adhesive layer 13 flow into the holes 15,15 ,.
・ 15 ... is blocked.

Then, depending on the type of the adhesive layer 13, ultraviolet irradiation or heating is performed to cure the adhesive 13 including the adhesives 13a, 13a ... Inside the holes 15, 15.

[Second Embodiment] Next, a second embodiment will be described with reference to FIGS. 4 to 6.

As shown in FIGS. 4 (a), (b) and FIG. 5, the optical memory device 17 has basically the same configuration as the optical memory device 10 of the first embodiment. However, in the optical memory element 17, instead of the holes 15, 15, ... In the protective substrate 14, a plurality of 18, 18, ... Are formed on the adhesive layer 13 side as passages to the outside air. That is, the protective substrate 14 is formed with a plurality of grooves 18, 18 ... Radiating from the center of the protective substrate 14 while being in contact with the adhesive layer 13 and having outer peripheral ends communicating with the outside air.
It should be noted that the same reference numerals are given to the parts having the same configuration as the first embodiment.

 The manufacturing procedure of the optical memory device 17 will be described below.

Similar to the first embodiment, first, as shown in FIG. 6A, the magnetic recording film 12 is formed on the substrate 11, and then an adhesive is applied on the magnetic recording film 12 to form an adhesive. Form layer 13.

Next, as shown in FIG. 6 (b), when the protective substrate 14 is placed on the adhesive layer 13 and pressure is applied downward, when bubbles 16 are present in the adhesive layer 13, these 6 are discharged to the outside through the grooves 18, 18 ... As shown in FIG. 6 (c). Further, some of the adhesives 13a, 13a ... Of the adhesive layer 13 flow into the grooves 18,18, and the grooves 18,18 ...
Blocked by 3a. After that, the adhesive layer 13 is cured by a method according to the type of the adhesive layer 13.

Third Embodiment Next, a third embodiment will be described based on FIGS. 7 and 8.

As shown in FIGS. 7 (a), (b) and FIG. 8, the optical memory element 20 in the third embodiment is a combination of the first and second embodiments and extends in the thickness direction on the protective substrate 14. A plurality of holes 15 and 15 ... and a plurality of grooves 18 and 18 extending radially
, And are provided as passages for discharging bubbles. The manufacturing procedure of the optical memory element 20 will not be described in detail, but when the protective substrate 14 is attached, the bubbles 16 in the adhesive layer 13
16 are discharged to the outside through the holes 15 and 15 and the grooves 18 and 18, so that the bubbles 16 and 16 are less likely to remain in the adhesive layer 13.

Fourth Embodiment Next, a fourth embodiment will be described based on FIG.

The fourth embodiment relates to a double-sided recording type optical memory device.

That is, the optical memory device 21 is a transparent or opaque substrate made of resin such as polycarbonate or metal such as Al.
22 and a pair of magnetic recording films 23, 23 formed on both surfaces of the substrate 22, respectively.

Protective substrates 25, 25 are attached on the magnetic recording films 23, 23 via adhesive layers 24, 24, respectively. Each protective substrate 25 is made of a transparent member such as a light-transmissive resin, and a plurality of holes 26 extending in the thickness direction are provided as passages for discharging bubbles. The adhesive layer 24
As the adhesive forming the material, an adhesive having a light-transmitting property and having a refractive index substantially equal to that of the protective substrate 25 is used.

In manufacturing the optical memory device 21, first, the magnetic recording films 23, 23 are formed on the substrate 22 by vapor deposition, sputtering, etc., and then, on the magnetic recording films 23, 23, an adhesive made of, for example, an ultraviolet curable resin is used. Adhesive layer 24
Is formed.

Next, the protective substrates 25, 25 are placed on the adhesive layers 24, 24, and pressure is applied to the substrate 22 side. As a result, the adhesive layer 24
If there are bubbles inside 24, those bubbles will be
It is discharged to the outside through the holes 26, 26 of 25. Further, some of the adhesives 24a, 24a ... Of the adhesive layers 24, 24 flow into the holes 26, 26 ... And the holes 26, 26 ... Are closed. Then the adhesive layer 24
-The adhesive layers 24, 24 are cured by a method according to the type of 24.

In the above optical memory device 21, the protective substrate 25
Information is recorded or erased on the magnetic recording films 23, 23 by applying a magnetic field while irradiating the magnetic recording films 23, 23 with a laser beam via the magnetic field. Further, by irradiating the magnetic recording films 23, 23 with laser light through the protective substrates 25, 25, information is reproduced by utilizing the magneto-optical effect. In that case, the protective substrates 25, 25 are formed of a translucent material, and the adhesive layers 24, 24 are formed of a translucent adhesive having a refractive index substantially equal to that of the protective substrates 25, 25. For,
Information can be recorded / reproduced / erased smoothly, and the signal reproduction quality can be maintained at a high level.

〔The invention's effect〕

As described above, the method for manufacturing an optical memory element according to the present invention is an optical memory element in which a magnetic recording film is formed on a substrate and a protective substrate is bonded onto the magnetic recording film via an adhesive layer, The protective substrate has a plurality of holes extending in the thickness direction of the protective substrate to communicate the adhesive layer with the outside air, and the outer peripheral edge of the protective layer formed on the adhesive layer side and extending radially from the center of the protective substrate. This is a configuration in which a plurality of grooves communicating with the outside air are formed.

Thereby, the bubbles generated in the adhesive layer when the protective substrate is bonded are discharged to the outside through the plurality of holes and the grooves provided in the protective substrate, and the bubbles may remain in the adhesive layer. Less.

Therefore, deterioration of signal characteristics such as variation in size of recording bits due to contact of bubbles with the magnetic recording film is suppressed, and deterioration of the magnetic recording film due to contact of the magnetic recording film with outside air through the bubbles is also suppressed. Less likely to occur.

Moreover, the bubbles in the adhesive layer can be easily discharged without performing a special work such as vacuuming.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is an enlarged vertical partial sectional view of the optical memory device taken along the line AA of FIG. FIG. 2 is a plan view of the optical memory device. 3 (a) to 3 (c) are enlarged vertical sectional partial views showing the manufacturing procedure of the optical memory element. 4 to 6 show another embodiment of the present invention. FIG. 4 (a) is an enlarged vertical sectional partial view of the optical memory element taken along the line BB in FIG. FIG. 4 (b) is an enlarged vertical sectional partial view of the optical memory element taken along the line CC of FIG. FIG. 5 is a plan view of the optical memory device. 6 (a) to 6 (c) are enlarged vertical sectional partial views showing the manufacturing procedure of the optical memory element. 7 and 8 show still another embodiment of the present invention. FIG. 7 (a) is an enlarged vertical sectional partial view of the optical memory device taken along the line D-D in FIG. FIG. 7 (b) is an enlarged vertical sectional partial view of the optical memory element taken along the line EE in FIG. FIG. 8 is a plan view of the optical memory device. FIG. 9 is an enlarged vertical sectional partial view of an optical memory device according to another embodiment of the present invention. FIG. 10 and FIG. 11 are enlarged vertical sectional partial views showing a conventional optical memory device. 10 ・ 17 ・ 20 ・ 21 is optical memory device, 11 ・ 22 is substrate, 12 ・ 23
Is a magnetic recording film, 13 and 24 are adhesive layers, 14 and 25 are protective substrates, 15 and 26 are holes, 16 is a bubble, and 18 is a groove.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenji Ota 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Prefecture Sharp Corporation (72) Toshio Ishikawa 22-22 Nagaike-cho, Abeno-ku, Osaka Prefecture, Osaka Sharp Corporation Within

Claims (1)

(57) [Claims] 1. An optical memory device comprising a magnetic recording film formed on a substrate and a protective substrate adhered to the magnetic recording film via an adhesive layer, wherein the protective substrate is a protective substrate. A plurality of holes extending in the thickness direction for communicating the adhesive layer with the outside air and a plurality of grooves extending radially from the center of the protective substrate formed on the adhesive layer side and having outer peripheral ends communicating with the outside air are formed. An optical memory device characterized by being provided.