JPH05189809A - Optical recording medium - Google Patents

Abstract

PURPOSE:To prevent that a cartridge and a disk are rubbed and to prevent that heat is conducted from a spindle part. CONSTITUTION:A disk 1 has a structure wherein substrates 2, 3 on which recording layers 4, 5 have been formed are pasted by using an adhesive layer 6. Hubs 7, 8 are installed on the disk; they are chucked to a spindle part at a drive. The disk is incorporated inside a cartridge 9; rib parts 10, 11 are formed near the center hole of the cartridge. In order to prevent that the rib parts 10, 11 and the disk substrate 1 are rubbed due to their contact, sheetlike members 12, 13 which are lubricative and whose heat conductivity is good are pasted on the surface of the substrate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an optical recording medium.

[0002]

2. Description of the Related Art Optical recording media (write-once type, magneto-optical, phase change, R
OM) is generally used by being included in a cartridge case to prevent scratches and dust. However, since there is a portion where the cartridge case and the disk come into contact with each other, rubbing occurs at this portion and shavings are generated, which causes troubles such as defocusing when attached to the surface of the substrate. So, for example, actual Kaihei 1-901
No. 62, No. 1-90173, No. 1-90173.
Japanese Laid-Open Patent Publication No. 93670 proposes that a sheet material having good lubricity is inserted between the cartridge case and the disk to prevent rubbing.

On the other hand, a polycarbonate (hereinafter PC) resin is generally used as the optical disk substrate. PC
Has a large photoelastic constant, so that when locally heated, there is a problem that birefringence increases due to thermal deformation.
In particular, a drive for recording / reproducing a disk has a problem that the temperature rises during use, heat is transferred from the spindle to the disk, the heat reaches the recording area, and the signal quality deteriorates. The above-mentioned publications do not consider this heat conduction and cannot prevent signal deterioration due to heat transfer from the spindle.

[0004]

[Object] The present invention has been made in view of the above-mentioned circumstances, and prevents the friction between the cartridge and the disk, and also prevents the heat conduction from the spindle part to improve the signal characteristics. It was made for the purpose of providing a medium.

[0005]

In order to achieve the above object, the present invention provides (1)
In an optical disc having an optical recording layer provided on a plastic substrate, the cartridge containing the optical disc and the cartridge side of the portion in contact with the optical disc substrate and / or a part or the whole of the optical disc side have lubricity and thermal conductivity. Is provided, and further, (2) the member having lubricity and good thermal conductivity is made of metal or a composite of metal and resin, and (3) the lubricity is good. It is characterized in that a member having a good thermal conductivity is attached to both sides of the inside of the recording area outside the clamp zone on the surface of the substrate. Hereinafter, description will be given based on examples of the present invention.

FIG. 1 is a block diagram for explaining an embodiment of an optical recording medium according to the present invention, in which 1 is a disk,
2, 3 are substrates, 4, 5 are recording layers, 6 is an adhesive layer, 7 and 8 are hubs, 9 is a cartridge, 10 and 11 are ribs, 12,
Reference numeral 13 is a lubricative heat conductive member. The disc 1 has a structure in which substrates 2 and 3 provided with recording layers 4 and 5 are bonded together by an adhesive layer 6. Further, the disk is provided with hubs 7 and 8 so that it is chucked by a spindle portion (not shown) of the drive. This disk is contained in the cartridge 9, and rib portions 10 and 11 are provided near the center hole of the cartridge 9. A sheet-like member 1 having good lubricity and thermal conductivity in order to prevent rubbing due to contact between the rib portions 10 and 11 and the disk substrate.
2, 13 are attached to the surface of the substrate.

As a material for the sheet-like member, a metal such as Al (aluminum), Cu, Au, Fe, stainless steel, or a resin containing metal powder is used. Also, a composite material in which a resin coat is provided on a metal sheet can be used. The thickness of the sheet is preferably 0.05 mm to 0.2 mm, and the shape is
Such as a ring or polygon that is connected to one,
It is also possible to attach a plurality of members having arbitrary shapes. The metal surface is preferably mirror-finished. Also, the cartridge 9
It is also possible to provide a lubricating member on the rib portions 10 and 11 of the above, and in this case, the material can be selected without considering heat conduction. In addition, although this embodiment is a pasting type,
It can also be applied to a so-called air sandwich type in which two substrates are bonded together via a spacer. The optical recording medium is not limited to the write-once type, the magneto-optical type, the phase change type, the ROM and the like.

FIG. 2 is a diagram showing a single plate type, in which 1
Reference numeral 4 is a rib, 15 is a brim portion, 16 and 17 are lubricious and thermally conductive members, 18 is a cartridge, 19 and 20 are rib portions, 21
Is a substrate and 22 is a recording layer. The recording layer 2 is formed on the substrate 21.
2 are provided, the rib 14 is provided on the inner peripheral portion, and the brim portion 1 is provided.
It is joined to the substrate at 5. The single plate type media is
It can also be used as a magnetic field modulation type medium, and in order to do so, not only the light-incident side lubrication member 16 that has been conventionally considered to prevent dust buildup, but also the recording layer side lubrication member 17 is provided. is necessary. As a result, it is possible to prevent dust from being generated due to friction with the rib portions 19 and 20 of the cartridge 18, and it is possible to provide a medium that is free from troubles due to magnetic field modulation.

The area in which the member of the present invention is provided needs to be provided outside the clamp area and inside the recording area that does not affect recording and reproduction in order to avoid affecting tilt. In the present invention, by providing a member having good heat conduction between the clamp area and the recording area, the heat dissipation effect of releasing the heat transmitted through the substrate from the spindle in the middle when the medium is mounted in the drive is enhanced, and the recording area It is possible to prevent a rapid temperature rise. Therefore, it is possible to prevent the deterioration of the recording / reproducing signal.

An evaluation example will be shown below. ISO with a diameter of 86 mm
SiNx900 as a dielectric layer on a formatted substrate
Å, TbDyFeCo200Å as a magnetic layer, SiNx300Å as a dielectric layer, and Al400 as a reflective layer
Å was provided and covered with UV curable resin. Further, a hard coat was provided on the surface of the substrate on the light incident side. A hub was bonded to the center of the substrate with a UV adhesive. A ring-shaped Al / PET sheet having an inner diameter of 23 mm, an outer diameter of 32 mm and a thickness of 0.15 mm was attached to both sides of this disc and housed in a cartridge. After oscillating this cartridge for 1 hour at 20 Hz and an amplitude of 5 mm, the disk surface was observed, but no dust due to rubbing could be detected.

The internal temperature of this cartridge is 50
C for 30 minutes immediately after inserting into the drive that reached ℃
The / N change was measured but there was no change. A as a comparative example
When a test similar to the above was performed except that the l / PET sheet was not provided, several tens of dust due to rubbing were detected after the vibration test. Also, 5 minutes after inserting the drive, C /
N decreased by 2 dB. It recovered after 15 minutes.

[0012]

As is apparent from the above description, according to the present invention, by providing a member having lubricity and good thermal conductivity, it is possible to prevent dust from being generated due to friction between the disk and the cartridge, and further, to prevent dust from coming from the spindle. It is possible to prevent heat conduction and prevent signal quality deterioration. Also, in the single plate type,
It is also possible to prevent dust on the recording layer side.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of an optical recording medium according to the present invention.

FIG. 2 is a diagram showing a single plate type.

[Explanation of symbols]

1 ... Disk, 2, 3 ... Substrate, 4, 5 ... Recording layer, 6 ... Adhesive layer, 7, 8 ... Hub, 9 ... Cartridge, 10, 11 ...
Ribs, 12, 13 ... Lubricating heat conductive member.

Claims (3)

[Claims] 1. An optical disc having an optical recording layer provided on a plastic substrate, wherein a cartridge containing the optical disc and a portion of the cartridge side of the portion where the optical disc substrate comes into contact and / or the optical disc side have lubricity. An optical recording medium is provided with a member having good thermal conductivity. 2. The optical recording medium according to claim 1, wherein the member having lubricity and good thermal conductivity is made of metal or a composite of metal and resin. 3. A member having lubricity and good thermal conductivity is attached to both surfaces of a portion outside the clamp zone on the surface of the substrate and inside the recording area. 1. The optical recording medium according to 1.