JPH0836782A - optical disk - Google Patents

Abstract

(57) [Abstract] [Purpose] The amount of wear debris generated by the contact between the disc outer periphery and the disc holding part, or the lever part is greatly reduced, which makes it possible to withstand severe impacts during transportation. Provide a disc cartridge that can withstand enough. [Structure] 2P having track grooves on a glass substrate
A recording layer, a recording film layer, and silicon nitride sandwiching the recording film layer to protect it, and two substrates on which an acrylic resin layer is sequentially formed to protect the recording film layer and the silicon nitride layer. A double-sided disk is obtained by bonding the surface with the acrylic resin inside with an adhesive. The acrylic resin member covers the outer peripheral portion of the glass substrate so that the glass substrate and the disc holding member do not come into direct contact with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc used for recording at least information.

[0002]

2. Description of the Related Art Generally, an optical disk used for recording and reproducing information (hereinafter, simply referred to as a disk) is housed between two shells as shown in FIG. Has become. If the optical disc moves and contacts the shell in the disc cartridge, the optical disc may be scratched or dust scraped by the contact between the optical disc and the shell may adhere to the optical disc, resulting in inaccurate reading of information. In order to prevent this, means for holding the optical disk in the cartridge so as not to move is provided.

When recording and reproducing information on the disc, it is necessary to make the disc rotatable inside the cartridge. Therefore, the disc holding portion is separated from the disc when the disc rotates. But,
When the cartridge is taken out of the recording / reproducing apparatus, the disc is sandwiched by the disc holding means and the lever so as not to come into contact with the shell, and the disc is fixed in the cartridge.

FIG. 3 shows an example of a disk. In this disc, a photopolymer layer having track grooves (hereinafter referred to as a 2P layer) is formed on a glass substrate, and a silicon nitride layer for sandwiching and protecting the recording layer is provided on the photopolymer layer. . Further, an acrylic resin layer is provided to protect the recording layer and the silicon nitride layer. These two sheets are pasted together with an adhesive to form a disc on which recording and reproduction can be performed from both sides.

[0005]

By the way, the lever 5 in FIG. 4 is repeatedly moved as shown by the arrow every time the disc cartridge is taken in and out of the recording / reproducing apparatus, and accordingly, the disc holding portion and the disc are moved. When the glass substrate corresponding to the outer peripheral surface comes into contact with or separates from the glass substrate, the outer periphery of the disc holding portion and the disc slip.

The disc holder is made of a material having a high elasticity (for example, polyamide) in order to absorb the impact received from the disc. There is a problem in that it is scattered in the cartridge and becomes one of the causes of causing an error in reading or writing of information.

[0007]

The present inventors have found that the above problems can be solved by providing a member having excellent wear resistance on the outer peripheral portion of the disk in order to solve such problems. Came to make. Therefore, the present invention provides a disk (invention of claim 1) characterized in that a polymer material is provided on the outer peripheral portion.

[0008]

According to the present invention, by reducing the abrasion powder scraped off from the disk holding portion, information reading and writing errors can be prevented. According to the present invention, since the polymer material is provided on the outer peripheral portion of the disc, the difference in hardness from the disc holding portion is reduced and abrasion powder is less likely to be generated, so that errors in reading and writing information can be reduced.

Although it is easy to use an acrylic resin material or an epoxy resin material as the polymer material, even if silicon rubber, urethane resin or the like is used, the generation of abrasion powder can be greatly reduced. Further, polyamide and fluororesin are more desirable.

[0010]

1 is a vertical sectional view of a disk according to this embodiment. 2 with track groove on glass substrate
A P layer, a recording film layer, silicon nitride sandwiching the recording film layer to protect the same, and two substrates on which an acrylic resin layer is sequentially formed to protect the recording film layer and the silicon nitride layer. Are bonded to each other with an adhesive so that the side having the acrylic resin is the inside, thereby forming a double-sided disc. The acrylic resin member covers the outer peripheral portion of the glass substrate so that the glass substrate and the disc holding member do not come into direct contact with each other.

[0011]

As described above, according to the present invention,
In order to improve the wear resistance of the disc holding part, a protective member is provided on the outer peripheral part of the disc, so that the generation of abrasion powder caused by the contact between the outer peripheral part of the disc and the disc holding part or the lever part As a result, it has become possible to sufficiently withstand a severe impact during transportation.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a disk showing the present invention.

FIG. 2 is a block diagram of a conventional disk cartridge.

FIG. 3 is a vertical sectional view of a conventional disc.

[Explanation of symbols]

 1 ... Disc holding part 2 ... Shell 1 3 ... Shell 2 4 ... Disc 5 ... Lever 6 ... Lever spring 7 ... Shutter

Claims (1)

[Claims] 1. An optical disk, characterized in that a separate member made of a polymer material is provided on the outer peripheral portion.