JPH01251376A - Optical disk medium with hub - Google Patents

Abstract

PURPOSE:To attain an interchange with a two-side type medium with a simple structure by making the thickness of a hub equal to a thickness that two disks are pasted. CONSTITUTION:An information recording layer 1 is formed on a transparent substrate 2 and by projecting a laser beam 3 from one side, information can be recorded and reproduced. A hub 6 joined to the central part of the substrate 2 with adhesive agent has the thickness equal to the thickness that two optical disks are pasted. Consequently, it is clamped by the same clamp mechanisms 7 and 7' as those by which the two-side type optical disk medium is fitted. The hub 6 has a center hole and by fitting a center pin 8 of a device, the center of the disk is set and the center pin 8 is prevented from damaging the inner circumference part of the substrate 2. Thus, the interchangeability with the two-side type disk medium can be held with the simple structure.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to optical disc media such as compact discs, video discs, write-once type information recording discs, and erasable information recording discs, and particularly relates to optical disc media such as compact discs, video discs, write-once type information recording discs, erasable information recording discs, etc. and/or relates to a hub-attached optical disk medium in which a hub forming a center hole is joined to one reproducible optical disk.

[Conventional technology]

Optical disk media include single-sided disk media that allow information to be read and written from only one side, and double-sided disk media that allow information to be read and written from both sides.

FIG. 4 is a schematic cross-sectional view of such a conventional double-sided optical disc medium mounted on a rotating mechanism of a recording/reproducing apparatus. In Fig. 4, 1.1' is the information recording layer, which may be a single-layer recording layer or a composite layer with various auxiliary layers (reflection layer, protective layer, interference layer, etc.). It is about 1 μm from 100A. Although not shown, a protective layer of 0.5 to 50 μm and 8 degrees may be further provided on the recording layers 1 and 1'. 2, 2' are transparent substrates, generally 1.2
The thickness may be about 0.2 to 4 mm, and an optical disk is constructed by bonding these two substrates together with an adhesive layer 14. 3, 3'u Indicates the direction of incidence of laser light for writing and reading information. 16
．． Reference numeral 16' is a bar provided so that the circle formed by the tracking guide (guide groove) rotates without eccentricity, and to prevent the edge of the inner diameter portion of the substrate from being damaged by the center pin of the reading device. These hubs 16, 16' are typically joined to the disc by adhesive 4.4'. Numerals 7 and 7' are clamp mechanisms for holding and rotating the disk of the optical disk device, and 8 is a center pin for centering the tracking guide. It is important for such an optical disk read/write device to be compatible with both double-sided and single-sided disk media. However, providing a device with such a mechanism for compatibility will lead to a significant increase in cost. Therefore, conventionally, a disk medium has been constructed as shown in FIG. FIG. 3 shows a schematic cross-sectional view of a single-sided disk medium. 1.2.3 in the figure are the second
As in the figure, the information recording layer, substrate, and direction of incidence of laser light are shown. Reference numeral 5 designates a ring-shaped spacer member, which is provided so that the portion corresponding to the clamping mechanism of the optical disk device has the same thickness as the substrate 2' shown in FIG. Reference numeral 4 denotes an adhesive layer that adheres the spacer members 5 together. The single-sided disk medium shown in FIG. 3 may be compatible with double-sided disks, but it does not have the nozzles 16 and 16' as shown in FIG. 4, so the transparent substrate 2 and center pin 8 are in contact with each other. However, the optical disc was prone to chips and cracks, and it was difficult to locate the center of rotation.

[Summary of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide an optical disc medium with a knob that has a simple structure and is compatible with double-sided disc media.

The above-mentioned object of the present invention is to reduce the thickness of the hub in an optical disc medium with a knob, which is formed by joining a knob constituting a center hole to one optical disc capable of recording and/or reproducing information on only one side. This is achieved by having a thickness equal to that of two disks bonded together.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing a state in which an optical disk medium according to the present invention is mounted on a rotation mechanism of a recording/reproducing apparatus.

In FIG. 1, the same members as in FIG. 4 are given the same reference numerals.

An information recording layer 1 is formed on a transparent substrate 2, and information can be recorded and reproduced by irradiating a laser beam 3 from one side with an adhesive 4 in the center of the substrate 2. Professionally bonded.

This hub 6 has a thickness corresponding to the thickness of two optical disks bonded together as shown in FIG. Therefore, the same clamping mechanism 7, 7' is used to mount the double-sided optical disc medium.
clamped by. That is, the single-sided optical disc medium of this embodiment is compatible with the double-sided optical disc medium.

In addition, this professional has a center hole, and when the center pin 8 of the device hits it, the center of the disk is centered, and this center pin 8 allows the substrate to be
This prevents the inner circumference from being damaged.

The thickness of the hub 6 is determined by taking into consideration not only the thickness of the two substrates but also the thickness of the information recording layer 1.1' and the adhesive layer 14 as shown in FIG. In some cases, a resin layer for forming guide grooves (groups) and signal bits of preformat signals, so-called 2P (photo polymer
) The thickness also takes into account the molding layer.

The present invention can also be applied to discs containing cartridges. An example of this is shown in FIG.

FIG. 2 is a schematic sectional view showing another embodiment of the hub-attached optical disk medium of the present invention. In the figure, the same members as in FIG. 1 are given the same reference numerals, and detailed explanations will be omitted.

In FIG. 2, the optical disc medium is housed in a cartridge 9 for protection.

In conventional optical disk media, when the same cartridge is used for double-sided and single-sided media, there is a problem in that the single-sided media shakes inside the cartridge due to the difference in thickness. In this embodiment, since the hub 6 has the same thickness as the double-sided media, it can fill the gap between the cartridge 9 and the disk and suppress this rattling. Therefore, a common cartridge can be used for single-sided and double-sided types without considering the above problems.

〔Effect of the invention〕

As explained above, in the present invention, in a conventional single-sided optical disk medium with a hub, the thickness of the hub is the same as that of two disks bonded together, making it possible to make it compatible with double-sided media with a simple configuration. Ta.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an optical disc medium according to the present invention attached to a rotating mechanism of a recording/reproducing device, FIG. 2 is a schematic sectional view showing another embodiment of the present invention, and FIG. 3 is a conventional sectional view. FIG. 4 is a schematic cross-sectional view showing the configuration of a conventional single-sided optical disc medium, and FIG. 4 is a schematic cross-sectional view showing a state in which a conventional double-sided optical disc medium is mounted on a rotation mechanism of a recording/reproducing apparatus. 1...Information recording layer 2...Transparent substrate 3...Laser beam 4...Adhesive 6...Hub 7.7'...Flang mechanism 8...Center pin Fig. 4

Claims (1)

[Claims] (1) In a hub-equipped optical disk medium in which a hub forming a center hole is attached to one optical disk capable of recording and/or reproducing information on only one side, the hub has two disks bonded together. An optical disk medium with a hub, characterized in that it has a thickness corresponding to the thickness of the optical disc medium.