JPH0244543A - Optical information recording disk - Google Patents

Abstract

PURPOSE:To improve recording/reproducing characteristics at the time of high speed revolution by opening a center hole to the central part of disk-shaped members and providing a means for positioning an inner peripheral spacer to this center hole. CONSTITUTION:A folded back part 3b is integrally formed to the inner peripheral part of the inner peripheral spacer 3 and the positioning of the inner peripheral spacer 3 is executed by inserting this folded back part 3b into the center hole 7a of optical recording veneers 1, 2. The inner peripheral spacer 3 can, therefore, be mounted to the central part of the optical recording veneers 1, 2 with high accuracy. Generation of incorrect oscillation is obviated even if the disk is rotationally driven at a high speed and the recording/reproducing characteristics are improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a disc-shaped member in which two disc-shaped members each including at least one optical recording single plate are bonded together concentrically via an inner circumferential spacer and an outer circumferential spacer. The present invention relates to an optical information recording disk, and particularly to a means for positioning an inner spacer.

(Prior Art) Conventionally, as shown in FIG.
An optical information recording disk with a so-called air sand inch structure is known, in which two optical recording single plates 25°26 are bonded together via a 4-layer disc ([Easy to Understand Optical Disc], Optronics Co., Ltd., December 10, 1985). (Published on 19th, p. 52)
.

A center hole 27. is provided in the center of the optical recording single plate 25.26.
A spiral or concentric guide track 29 having the same center as the center hole 27, 28 is formed on the forming surface of the recording layer 21, 22.

The inner circumferential spacer 23 allows the disk drive shaft to be inserted into the center hole 27 and 28 regardless of variations in allowable dimensional accuracy.
．． It is formed into a ring shape having an inner diameter slightly larger than the diameter of 28. On the other hand, the outer circumferential spacer 24 is formed in a ring shape having an outer diameter equal to the outer diameter of the optical recording single plate 25, 26 so that there is no problem as described above even if the dimensional accuracy varies within an allowable range. .

When assembling the optical information recording disk, the outer circumferential spacer 24 is positioned by matching its outer circumferential edge with the outer circumferential edge of one of the optical recording single plates, and is adhered to the one optical recording single plate. On the other hand, since there is no positioning method for the inner circumferential spacer 23, it can be bonded only by roughly positioning it with the center hole formed in the one optical recording single plate. Thereafter, the other optical recording single plate is adhered from the other side of the inner circumferential spacer 23 and the outer circumferential spacer 24 to form a desired optical information recording disk.

The optical information recording disk has the center hole 27 or 2.
8, by inserting a disk drive shaft provided in a disk drive device (not shown) into the guide track 29.
The driving force of the disk drive shaft is transmitted to the optical recording single disk, and information is recorded/reproduced.

[Problem to be solved by the invention]

In recent years, increasing the recording capacity and increasing the data transfer speed have become one of the most important technical issues for this type of optical information recording disk. There is a trend toward increasingly faster rotational drive speeds.

However, the conventional optical information recording disk described above.

Since the inner circumferential spacer 23 is not provided with any positioning means and cannot be accurately set at the center of the optical information recording disk, the dynamic balance tends to become unbalanced, and the surface may be distorted during one rotation. There is a problem that irregular vibrations such as runout are likely to occur. If the optical information recording disk vibrates abnormally, the trajectory of the guide track relative to the recording/reproduction beam spot becomes elliptical, making it difficult to follow the beam spot, and in the worst case, the laser beam may go off track, causing the laser beam to go off track. This may cause a situation where recording/playback becomes impossible. The dynamic imbalance becomes more pronounced as the rotational speed of the optical information recording disk increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical information recording disk with good positioning accuracy of an inner spacer and excellent recording/reproducing characteristics during high-speed rotation.

[Means to solve the problem]

In order to achieve the above object, the present invention provides positioning of an inner circumferential spacer with respect to a center hole formed in the inner circumferential spacer itself or separately from the inner circumferential spacer in a disk-shaped member constituting an optical information recording disk. It is characterized by providing means.

[Effect]

By doing the above, simply attaching the inner circumferential spacer to the center hole of the disk-shaped member along the positioning means,
It is possible to position the inner circumferential spacer, that is, to accurately center the inner circumferential spacer with respect to the optical information recording disk.

On the other hand, as described above, the outer circumferential spacer can be accurately centered with respect to the optical information recording disk by aligning its outer circumferential edge with the outer circumferential edge of the disk-shaped member.

Therefore, the dynamic balance becomes balanced, and irregular vibrations during rotational driving are prevented, and the recording/reproducing characteristics during high-speed rotation can be improved.

〔Example〕

First, a first embodiment of the present invention will be described based on FIGS. 1 to 4. Here, FIG. 1 is a sectional view of the optical information recording disk according to the first embodiment, FIG. 2 is a plan view of the optical information recording disk of FIG. 1, FIG. 3 is a perspective view of the inner spacer, and FIG. The figure is a perspective view of the outer circumferential spacer.

In the optical information recording disk of the first embodiment, as shown in FIG. A hub 5 is attached to the outer peripheral surface of the central part of each optical recording single plate 1゜2.
is fixed.

The optical recording single plates 1 and 2 are each formed by forming a recording layer 8 on the surface of a substrate 7 having a signal pattern 6 formed thereon.

The substrate 7 is made of, for example, transparent ceramics such as glass,
It is made of a transparent resin material such as polycarbonate, polymethyl methacrylate, polymethyl pentene, or epoxy, and is formed into a disk shape with a center hole 7a in the center. The signal pattern 6 is as shown in FIG.
The substrate 7 is formed spirally or concentrically around the central axis P. Further, the center hole 7a is formed on the substrate l.
It is established around the central axis P of.

The recording layer 8 is formed of an appropriate heat mode recording material depending on the type of the optical information recording disk.

As shown in FIG. 3, the inner peripheral spacer 3 is composed of a ring-shaped main part 3a and a cylindrical folded part 3b formed by folding the inner peripheral edge thereof substantially vertically. The diameter D1 of the outer circumferential surface of the folded portion 3b is formed to a size that allows the folded portion 3b to be inserted into the center hole 7a formed in the substrate 7 somewhat tightly. This makes it possible to automatically center the main portion 3a.

The inner circumferential spacer 3 is formed of a molded product of a metal material such as aluminum or a synthetic resin material, for example.

The outer spacer 4 is formed into a ring shape having an outer diameter equal to the outer diameter Dz of the substrate 7, as shown in FIG.

The thickness Sz of the outer circumferential spacer is formed to be equal to the thickness Sl of the main portion 3a of the inner circumferential spacer 3. This outer spacer 4 is also formed of the same material as the inner spacer 3.

The hub 5 is provided to protect the center hole 7a formed in the substrate 7, or to protect the center hole 7a and magnetically clamp the optical information recording disk to a disk drive shaft provided in the disk drive device. . The hub 5 provided to protect the center hole 7a is
It is formed of a material 1 that is harder than the substrate 7, such as metal. Further, the hub 5, which is provided to protect the center hole 7a and to magnetically clamp the optical information recording disk to the disk drive shaft, is made of a hard and corrosion-resistant magnetic material such as magnetic stainless steel.

The hub 5 is formed into a ring shape as shown in FIG. 2, and a synthetic resin holder 9 having an expansion coefficient similar to that of the substrate 7 is integrally molded on its outer periphery. These hub 5 and holder 9 are fixed to the outer surface of the central part of the substrate 7, with the central axis of the hub 5 aligned with the central axis P of the substrate 7. The inner diameter of the hub 5 is smaller than the inner diameter of the inner spacer 3.

Hereinafter, a method of manufacturing the optical information recording disk of the first embodiment will be explained.

First, the folded portion 3b of the inner circumferential spacer 3 is inserted into the center hole 7a of the first optical recording single plate 1 of the two optical recording single plates, and the inner circumferential spacer 3 is centered with respect to the center hole 7a. Then, the back surface of the main portion 3a is adhered to the surface of the first optical recording single plate l on which the recording layer 8 is formed using an adhesive 10. These members 1
．． The adhesive 10 for bonding 3 can be selected from any known adhesives, but a photocurable resin is particularly preferred because of its good workability.

Next, the outer circumferential edge of the first optical recording single plate 1 and the outer circumferential edge of the outer circumferential spacer 4 are aligned, and the outer circumferential spacer 4 is attached to the recording layer 8 forming surface of the first optical recording spout plate 1 using an adhesive 10. Glue. As an adhesive 10 for bonding these members 1 and 4,
Photocurable resins are particularly suitable.

Next, the outer circumferential edge of the first optical recording single plate 1 and the outer circumferential edge of the second optical recording single plate 2 are aligned, and a second optical recording unit is placed on the other surfaces of the inner circumferential spacer 3 and outer circumferential spacer 4. Board 2 record W
Adhere the J8 forming surface with adhesive IO. These parts 2
,3. A photocurable resin is particularly suitable as the adhesive for bonding the '4.

Finally, align the center axis of the hub 5 with the center axis of the board 7 (center hole 7
The holder 9 is fixed to the outer surface of the central part of each optical recording single plate 1.2 so as to coincide with the central axis (a) P of the optical recording single plate 1.2.

As means for fixing the holder 9 and the optical recording single plates 1 and 2, means such as adhesion, fusing, and screwing can be used.
Adhesion is particularly suitable because of its good workability.

A photocurable resin is particularly suitable as the adhesive for bonding these members 1, 2.9 together.

The optical information recording disk of the above embodiment has a folded part 3b integrally formed on the inner peripheral part of the inner circumferential spacer 3, and this folded part 3b is inserted into the center hole 7a of the optical recording single plate 2. Since the inner spacer 3 is positioned, the inner spacer 3 can be attached to the center of the optical recording single plate 1.2 with high precision. Therefore, the dynamic balance of the optical information recording disk becomes balanced, and even if it is rotated at high speed, no undesirable vibration occurs, and the recording/reproducing characteristics are improved.

In addition, positioning means for the inner circumferential spacer 3 (folded portion 3a
) is formed integrally with the inner peripheral spacer 3, so the number of parts does not increase and it can be implemented at low cost.

Furthermore, since the hub 5 for inserting the disk drive shaft is attached to the center of the outer surface of the optical recording single plates 1 and 2, the inconvenience of wear of the center hole 7a can be avoided. Furthermore, since the synthetic resin holder 9 is formed around the hub 5, stress caused by the difference in expansion coefficients between the hub 5 and the substrate 7 is alleviated, and problems such as birefringence in the substrate 7 are not caused. .

Next, a second embodiment of the present invention will be described based on FIGS. 5 and 6.

FIG. 5 is a sectional view of an optical information recording disk according to the second embodiment, and FIG. 6 is a perspective view of an inner peripheral spacer installed in this optical information recording disk, and each of FIGS. The same reference numerals are shown for corresponding members. The other members except for the inner circumferential spacer 3 are the same as those of the first embodiment, and their explanation will be omitted to avoid duplication.

As shown in FIGS. 5 and 6, the inner circumferential spacer 3 is
A ring-shaped main part 3 extending outward is provided at the center of the outer surface of the cylindrical part 3c, which has a diameter that allows it to be inserted into the sensor hole 7a somewhat tightly.
a is integrally formed.

The length Ll of the cylindrical portion 3C protruding from the upper and lower surfaces of the main portion 3a is formed to be shorter than the thickness T1 of the substrate 7.

When assembling the optical information recording disk of the second embodiment,
One of the cylindrical portions 3c formed integrally with the inner circumferential spacer 3 is inserted into the center hole 7a of the first optical recording single plate 1 of the two optical recording single plates, and the inner circumferential spacer 3 is inserted into the center hole 7a. Perform centering. Then, the back surface of the inner spacer 3 is adhered to the surface of the first optical recording single plate 1 on which the recording layer 8 is formed. The subsequent adhesion of the first optical recording jet plate l and the outer circumferential spacer 4;
The adhesion of the second optical recording single plate 2 to the inner circumference spacer 3 and the outer circumference spacer 4, and the adhesion of the optical recording single plates 1 and 2 to the holder 9 are the same as in the first embodiment.

The optical information recording disk of the second embodiment has the same effects as those of the first embodiment, and also has a cylindrical portion 3c on the inner peripheral portion of the main portion 3a that extends in both directions of the front and back surfaces of the main portion 3a. This has the effect of facilitating centering of the first optical recording single plate 1 and the second optical recording single plate 2 when assembling the optical information recording disk.

Next, a third embodiment of the present invention will be described based on FIGS. 7 and 8.

FIG. 7 is a sectional view of an optical information recording disk according to a third embodiment, and FIG. 8 is an exploded perspective view of an inner spacer and a positioning cylinder installed in this optical information recording disk,
Reference numeral 11 indicates a positioning cylinder, and other members corresponding to those shown in FIGS. 1 to 4 are designated by the same reference numerals. The other members except for the inner circumferential spacer 3 and the positioning cylinder 11 are the same as those of the first embodiment, and their explanation will be omitted to avoid duplication.

The positioning cylindrical body 11 has an outer diameter that allows it to be fitted into the sensor hole a somewhat tightly, and its entire length is shorter than the total thickness T2 of the optical information recording disk. The positioning cylindrical body 11 can be made of any material having a fixed shape, but in order to prevent stress caused by the difference in expansion coefficient from acting on the optical recording single plates 1 and 2, the substrate 7 is made of It is preferable to use a material having a coefficient of expansion similar to that of the material.

The inner circumferential spacer 3 is formed into a ring shape having an inner diameter that allows it to be inserted into the outer circumferential surface of the positioning cylindrical body 11 rather closely.

When assembling the optical information recording disk of the third embodiment,
First, the positioning cylindrical body 11 is inserted into the center hole 7a of the first optical recording single plate 1 of the two optical recording single plates, and the positioning cylindrical body 11 is centered with respect to the center hole 7a.

In this case, the insertion depth of the positioning cylinder 11 is adjusted so that the tip end of the positioning cylinder 11 does not protrude beyond the adhesive surface of the hub 5 of the first optical recording plate 1.

Next, the inner circumferential spacer 3 is fitted from the tip of the positioning cylinder 11 protruding from the recording layer 8 forming surface of the first optical recording single plate l, and the inner circumferential spacer 3 is attached to the positioning cylinder 11.
Perform centering. Thereby, the inner circumferential spacer 3 is centered with respect to the center hole 7a.

Next, the back surface of the inner spacer 3 is adhered to the recording layer 8 forming surface of the first optical recording single plate l.

After that, the first optical recording single plate 1 and the outer circumferential spacer 4
The adhesion of the second optical recording single plate 2 to the inner peripheral spacer 3 and the outer peripheral spacer 4, and the adhesion of the optical recording single plates 1 and 2 to the holder 9 are the same as in the first embodiment. It is.

The optical information recording disk of the third embodiment also has the same effects as those of the first embodiment.

Next, a fourth embodiment of the present invention will be described based on FIGS. 9 and 10.

FIG. 9 shows optical information according to the fourth embodiment? ! 10 is an exploded perspective view of the positioning cylindrical body and inner circumferential spacer installed in this optical information recording disk, and corresponds to each member shown in FIGS. 7 and 8. Components are labeled with the same reference numerals. The other members except for the inner circumferential spacer 3 and the positioning cylinder 11 are the same as those of the first embodiment, and their explanation will be omitted to avoid duplication.

As shown in FIGS. 9 and 10, the positioning cylindrical body 11 has an outer diameter that allows it to be fitted into the 5-center hole 7a somewhat tightly;
It has a cylindrical shape with a length shorter than the total thickness Tl of the optical information recording disk, and a protrusion 12 having a thickness equal to the thickness Sl of the inner spacer is provided around the center of the outer peripheral surface. .

As shown in FIG. 9, the inner circumference spacer 3 has the protrusion I2.
It is formed into a ring shape having an inner diameter slightly larger than an outer diameter D3.

When assembling the optical information recording disk of the third embodiment,
First, the positioning cylindrical body 11 is inserted into the center hole 7a of the first optical recording single plate 1 of the two optical recording single plates, and the positioning cylindrical body 11 is centered with respect to the center hole 7a.

Next, the back surface of the protrusion 12 is adhered to the recording layer 8 forming surface of the first optical recording single plate 1 via the adhesive 10, and the positioning cylinder 11 is fixed.

Next, the inner circumferential spacer 3 is fitted onto the outer circumferential portion of the protrusion 12 via the adhesive 10, and the back surface of the inner circumferential spacer 3 is adhered to the surface of the first optical recording single plate 1 on which the recording layer 8 is formed. The inner diameter of the inner circumferential spacer 3 is formed to be slightly larger than the outer diameter of the protruding strip 12, but the inner circumference of the inner circumferential spacer 3 and the outer circumference of the protruding strip 12 are bonded together via an adhesive 10. Therefore, the inner spacer 3 is centered with respect to the positioning cylinder 11 with high precision due to the surface tension of the adhesive 10.

After that, the first optical recording single plate 1 and the outer circumferential spacer 4
, the adhesion of the second optical recording single plate 2 to the inner circumferential spacer 3 and the outer circumferential spacer 4, and the adhesion of the optical recording single plates 1 and 2 to the holder 9.

This is the same as in the first embodiment.

The optical information recording disk of the fourth embodiment has the same effect as that of the third embodiment, and also has a protrusion 12 formed at the center of the outer peripheral surface of the positioning cylinder 11. During assembly, there is an effect that positioning of the positioning cylinder 11 with respect to the optical recording single plates 1 and 2 is facilitated.

Next, a fifth embodiment of the present invention will be described based on FIGS. 11 and 12.

FIG. 11 is a cross-sectional view of an optical information recording disk according to a fifth embodiment, and FIG. 12 is an exploded perspective view of a hub, a holder, and an inner circumferential spacer mounted on this optical information recording disk.
The same reference numerals are indicated on the members corresponding to those shown in the figures to FIG. Inner spacer 3 and holder 9
The other members except for are the same as those of the first embodiment, and their explanation will be omitted to avoid duplication.

The holder 9 is integrally molded on the outer periphery of the hub 5 using a synthetic resin material, and has an outer diameter on the bottom surface that allows it to be fitted into the sensor hole a somewhat tightly, and is thicker than the thickness Tz of the substrate 7. A positioning cylindrical portion 13 is integrally formed, which is slightly longer and has a length slightly shorter than 1/2 of the total thickness T1 of the optical information recording disk.

The inner circumferential spacer 3 is formed into a ring shape having an inner diameter that allows it to be inserted into the outer circumferential surface of the positioning cylindrical portion 13 rather closely.

When assembling the optical information recording disk of the fifth embodiment,
First, the positioning cylindrical part 13 of the holder 9 is inserted into the center hole 7a of the first optical recording single plate 1 and the second optical recording single plate 2, and the back side of the holder 9 is inserted into the center hole 7a of the first optical recording single plate 1 and the second optical recording single plate 2. Glue to the outside surface. As a result, the hub 5 and the positioning cylindrical portion 13 are centered with respect to the center hole 7a.

Next, the inner spacer 3 is inserted into the outer circumference of the positioning cylindrical part 13 inserted into the first optical recording single plate 1, and the inner spacer 3 is centered with respect to the positioning cylindrical part 13. The back surface of the inner spacer 3 is adhered to the surface of the optical recording single plate 1 on which the recording layer 8 is formed. Thereby, the inner circumferential spacer 3 is centered with respect to the center hole 7a with high precision.

Thereafter, the optical recording single plate 1 of the cylinder 1 and the second optical recording single plate 2 to which the holder 9 has been bonded are bonded together with the recording layer 8 facing inward and via the outer circumferential spacer 4 to produce a desired light beam. It is an information recording disc.

The optical information recording disk of the fifth embodiment has the same effects as those of the second embodiment.

The gist of the present invention is that a center hole formed in a disk-shaped member constituting an optical information recording disk is provided with some kind of inner spacer positioning means, and the shape and structure of the positioning means are The present invention is not limited to the above embodiments. That is, the first to fifth embodiments are representative embodiments of the present invention, and the positioning means may have other shapes and configurations.

Furthermore, the gist of the present invention lies in the means for positioning the inner circumferential spacer, and the shape, structure, and material of other members such as the outer circumferential spacer, substrate, hub, holder, etc. can be arbitrarily designed as necessary. Of course it is.

In addition, in each of the above embodiments, a double-sided recording type optical information recording disk was explained as an example, but instead of one of the optical recording single disks, a signal pattern and a recording layer can be formed using substantially the same shape and the same size. A single-sided recording type optical information recording disc can also be obtained by using a protection plate on which no .

〔Effect of the invention〕

As explained above, the optical information recording disk of the present invention has
Since the inner spacer positioning means is provided, the inner spacer can be attached to the center of the optical information recording disk with high precision. Therefore, the dynamic balance of the optical information recording disk becomes balanced, and even when it is rotated at high speed, no undesired vibration occurs, and the recording/reproducing characteristics during high speed rotation can be improved.

[Brief explanation of the drawing]

1 to 4 are diagrams for explaining a first embodiment of the present invention, in which FIG. 1 is a sectional view of an optical information recording disk, FIG. 2 is a plan view of the optical information recording disk, and FIG. 3 is a perspective view of the inner spacer, and FIG. 4 is a perspective view of the outer spacer. 5 to 12 are diagrams for explaining other embodiments, in which FIG. 5 is a sectional view of an optical information recording disk according to the second embodiment, and FIG. 6 is a cross-sectional view of the optical information recording disk according to the second embodiment. FIG. 7 is a sectional view of the optical information recording disk according to the third embodiment; FIG. 8 is an exploded perspective view of the inner spacer and the positioning cylinder according to the third embodiment; FIG. 9 is a perspective view of the inner spacer; The figure is a sectional view of an optical information recording disk according to a fourth embodiment, and FIG. 10 is an exploded perspective view of an inner spacer and a positioning cylinder according to a fourth embodiment.
FIG. 11 is a sectional view of an optical information recording disk according to a fifth embodiment, and FIG. 12 is an exploded perspective view of an inner spacer and a holder according to the fifth embodiment. FIG. 13 is a sectional view showing an example of a conventionally known optical information recording disk. l: first optical recording single plate, 2: second optical recording single plate, 3: inner spacer, 4: outer spacer, 5: hub, 6: signal pattern, 7: substrate, 7a: center hole, 8 :Recording layer, 9:
Holder, 10: Adhesive, 11: Positioning cylinder, 12
: Projection, 13: Cylindrical part for positioning. Figure 4 jl! Figure 5 Figure 2 Figure 7 Figure 8 Figure 9 Figure 10 Figure 1 Figure 12

Claims (6)

[Claims] (1) In an optical information recording disk formed by concentrically bonding two disk-shaped members including at least one optical recording single plate through an inner circumferential spacer and an outer circumferential spacer, a center portion of the disk-shaped member 1. An optical information recording disk characterized in that a center hole is formed and means for positioning the inner peripheral spacer with respect to the center hole is provided. (2) The optical information recording disk according to claim 1, wherein the positioning means is formed integrally with the inner spacer. (3) The optical information recording disk according to claim 1, wherein the positioning means is formed separately from the inner spacer. (4) The optical information recording disk according to claim 1, wherein a hub for holding a disk drive shaft provided in a disk drive device is attached to the outer peripheral surface of the central portion of the disk-shaped member. Information recording disc. (5) The optical information recording disk according to claim 4, wherein the inner diameter of the hub is smaller than the inner diameter of the inner spacer. (6) The optical information recording disk according to claim 4, wherein means for positioning the inner spacer is formed on the hub.