JPH0440638A - Optical recording medium - Google Patents
Optical recording mediumInfo
- Publication number
- JPH0440638A JPH0440638A JP2146241A JP14624190A JPH0440638A JP H0440638 A JPH0440638 A JP H0440638A JP 2146241 A JP2146241 A JP 2146241A JP 14624190 A JP14624190 A JP 14624190A JP H0440638 A JPH0440638 A JP H0440638A
- Authority
- JP
- Japan
- Prior art keywords
- film
- recording
- thermal conductivity
- temp
- recording film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003287 optical effect Effects 0.000 title claims description 23
- 239000010410 layer Substances 0.000 claims abstract description 21
- 239000011241 protective layer Substances 0.000 claims abstract description 9
- 239000000463 material Substances 0.000 claims abstract description 7
- 239000000543 intermediate Substances 0.000 claims abstract 2
- 239000000758 substrate Substances 0.000 claims description 6
- 229910000838 Al alloy Inorganic materials 0.000 claims description 5
- 230000001678 irradiating effect Effects 0.000 claims 1
- 239000010408 film Substances 0.000 abstract description 56
- 230000035945 sensitivity Effects 0.000 abstract description 14
- 230000007423 decrease Effects 0.000 abstract description 3
- 239000010409 thin film Substances 0.000 abstract description 2
- 239000000203 mixture Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229920000515 polycarbonate Polymers 0.000 description 3
- 239000004417 polycarbonate Substances 0.000 description 3
- 229910017061 Fe Co Inorganic materials 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 229910018575 Al—Ti Inorganic materials 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001755 magnetron sputter deposition Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- -1 polytetrafluoroethylene Polymers 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
Landscapes
- Optical Record Carriers And Manufacture Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、光ビーム照射によって情報の記録あるいは消
去を行う光記録媒体に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical recording medium on which information is recorded or erased by irradiation with a light beam.
従来の光記録媒体、特に光ディスクへ記録を行う場合に
は、ディスクを一定の回転数で回転させるのが一般的で
ある。このため、記録するディスク半径方向の位置によ
って線速度が変わり、記録感度が異なる。すなわち、デ
ィスクの外周に行くほど線速度が速くなるため、記録感
度が悪くなる。When recording on a conventional optical recording medium, especially an optical disk, it is common to rotate the disk at a constant rotational speed. Therefore, the linear velocity changes depending on the position in the radial direction of the disk to be recorded, and the recording sensitivity differs. That is, the linear velocity increases toward the outer periphery of the disk, resulting in poor recording sensitivity.
そこで、特開昭63−102052号公報に記載のよう
に、ディスク半径方向で記録膜の膜厚を変える、あるい
は組成を変えるなどして、ディスク全面で一定の記録感
度が得られるような措置がとられていた。Therefore, as described in Japanese Patent Application Laid-Open No. 63-102052, measures have been taken to obtain a constant recording sensitivity over the entire surface of the disk by changing the thickness or composition of the recording film in the radial direction of the disk. It had been taken.
しかし、このような光ディスクは、作製するのが難しく
、コスト面でも非常に値段の高いものとなる。However, such optical discs are difficult to manufacture and are extremely expensive.
本発明の目的は、記録膜の組成や膜厚を半径方向で変え
ることなしに、ディスク全面で一定の記録感度が得られ
る光ディスクを提供することにある。An object of the present invention is to provide an optical disc that can provide constant recording sensitivity over the entire surface of the disc without changing the composition or thickness of the recording film in the radial direction.
上記目的は、記録膜の下地層あるいは保護層あるいは中
間層として、室温では熱伝導率が小さく、高温になるほ
ど熱伝導率が大きくなる材料を用いることによって達成
できる。The above object can be achieved by using a material that has low thermal conductivity at room temperature and increases in thermal conductivity as the temperature increases, as the underlayer, protective layer, or intermediate layer of the recording film.
ここで、以下の説明では、基板上に記録膜以外に数種類
の膜を積層する場合、基板上の膜を下地層、記録膜の上
に積層する膜を保護層、さらに下地層と記録層との間の
膜を中間層とする。In the following explanation, when several types of films are laminated on a substrate in addition to the recording film, the film on the substrate will be referred to as a base layer, the film laminated on top of the recording film will be referred to as a protective layer, and the base layer and recording layer will be referred to as a protective layer. The film in between is an intermediate layer.
一定の角速度で回転するディスクに一定強度の光を照射
すると、ディスクの外周に行くほど記録膜の温度上昇が
小さくなる。この結果、ディスクの径方向で記録感度の
違いが生じる。ここで、同じ大きさの記録点を記録する
のに要するレーザパワーの大きさを記録感度と呼ぶこと
にする。そこで、下地層あるいは保護層あるいは中間層
として、上述した熱伝導率の温度特性をもつ材料を用い
れば、ディスクの径方向に渡って記録膜の温度上昇が一
定となるため、常に一定の記録感度が得られる。この効
果は、特にSUS膜やAl合金膜を用いた場合に顕著で
ある。When a disk rotating at a constant angular velocity is irradiated with light of a constant intensity, the temperature rise in the recording film decreases as it goes toward the outer periphery of the disk. As a result, differences in recording sensitivity occur in the radial direction of the disk. Here, the amount of laser power required to record recording points of the same size will be referred to as recording sensitivity. Therefore, if a material with the above-mentioned thermal conductivity temperature characteristics is used as the underlayer, protective layer, or intermediate layer, the temperature rise of the recording film will be constant in the radial direction of the disk, so that the recording sensitivity will always be constant. is obtained. This effect is particularly remarkable when a SUS film or an Al alloy film is used.
記録膜の温度上昇は、記録膜の種類や回転数によって異
なるため、下地層あるいは保護層あるいは中間層の熱伝
導率の値や温度変化が適当になるように材料を選定する
必要がある。これは、SUS膜やAl合金膜では、その
組成比を変えることによって調整することができる。ま
た、各々の膜厚を適当に選ぶことによっても、記録膜の
温度上昇が一定となるように調整することができる。Since the temperature rise of the recording film varies depending on the type of recording film and the rotation speed, it is necessary to select materials so that the thermal conductivity value and temperature change of the underlayer, protective layer, or intermediate layer are appropriate. This can be adjusted by changing the composition ratio of the SUS film or Al alloy film. Furthermore, by appropriately selecting the thickness of each film, it is possible to adjust the temperature rise of the recording film to be constant.
一定の角速度で回転するディスクに一定強度の光を照射
すると、ディスクの外周に行くほど、単位時間に単位面
積あたり照射される光のエネルギーが小さくなる。この
ため、外周部に行くほど記録膜の温度上昇が小さくなり
記録感度が悪くなる。When a disk rotating at a constant angular velocity is irradiated with light of a constant intensity, the energy of the light irradiated per unit area per unit time decreases as it goes toward the outer periphery of the disk. For this reason, the temperature rise of the recording film becomes smaller toward the outer periphery, and the recording sensitivity becomes worse.
ここで、記録膜に接して、室温では熱伝導率が小さく、
高温になるほど熱伝導率が大きくなるような材料の薄膜
(ここでは−例として下地膜とする)を設けると、温度
上昇の大きくなる内周では下地膜の熱伝導率が大きいた
め、記録膜に発生した熱は速やかに下地層に伝わり、記
録膜自身の温度上昇は小さくなる。一方、温度上昇の小
さくなる外周では、下地膜の熱伝導率が小さくなるため
、記録膜に発生した熱は下地膜に伝わりにくくなる。Here, in contact with the recording film, the thermal conductivity is low at room temperature,
If a thin film of a material (here used as the base film as an example) whose thermal conductivity increases as the temperature rises is provided, the heat conductivity of the base film is high at the inner periphery where the temperature rises, so the recording film The generated heat is quickly transmitted to the underlayer, and the temperature rise of the recording film itself is reduced. On the other hand, at the outer periphery where the temperature rise is smaller, the thermal conductivity of the base film is lower, so that the heat generated in the recording film is less likely to be transmitted to the base film.
この結果、下地膜の熱伝導率の値や温度変化及び膜厚を
適当に調整することによって、外周での記録膜の温度上
昇を内周での温度上昇とほぼ同じにすることができる。As a result, by appropriately adjusting the thermal conductivity value, temperature change, and film thickness of the base film, the temperature rise of the recording film at the outer periphery can be made almost the same as the temperature rise at the inner periphery.
〔実施例1〕
第1図に本発明による光記録媒体の一実施例を示す、案
内溝を有する5、25 インチのポリカーボネート基板
1上に下地層2としてSUs膜を100人、中間層3と
してフッ素樹脂(ポリ四フッ化エチレン)膜を100人
、記録層4としてTe膜300人をそれぞれスパッタ法
により形成し、追記型(穴あけ型)光ディスクを作製し
た。[Example 1] FIG. 1 shows an example of an optical recording medium according to the present invention. On a 5.25-inch polycarbonate substrate 1 having a guide groove, 100 SUs films were deposited as an underlayer 2 and as an intermediate layer 3. A fluororesin (polytetrafluoroethylene) film was formed on 100 sheets and a Te film was formed on 300 sheets as the recording layer 4 by sputtering, respectively, to produce a write-once (perforated) optical disk.
ここで、SUSU2O5伝導率は第2図に示すように、
高温になるほど小さくなる。Here, the SUSU2O5 conductivity is as shown in Figure 2.
The higher the temperature, the smaller it becomes.
これに対して、従来構造の追記型光ディスクでは第3図
に示すように下地層(フッ素樹脂膜)5と記録層4(T
e膜)の2層である。On the other hand, in a write-once optical disc having a conventional structure, as shown in FIG.
There are two layers of e-membrane.
上述した2種類の光ディスクを180Orpmで回転さ
せ、波長830nmの半導体レーザを搭載した光ヘッド
を用いてビットを記録した。このとき従来の光ディスク
では、第4図のように、ディスク最内周(半径30m+
)及び最外周(半径60■)に直径0.8μmの円径ビ
ットを記録するために必要なレーザパワーは、最内周で
は7mW、最外周では10mWであった。ここで、パル
ス幅は6Qnsecとした。すなわち、従来の光ディス
クではディスクの外周に行くほど大きなレーザパワーが
必要となる。これに対して、本発明による光ディスクを
用いると、直径0.8μmのビットを記録するためのレ
ーザパワーは、最内周、最外周共にほぼ等しく約11m
Vv’であった。従って、本発明による光ディスクを用
いれば、常にほぼ一定のレーザパワーで同じ大きさのビ
ットを記録することができる。また、記録膜の種類や回
転数が異なる場合でも、SUS膜の組成や膜厚を適当に
調整することによって、ディスク全面に渡ってほぼ一定
の記録感度を得ることができる。The two types of optical disks described above were rotated at 180 rpm, and bits were recorded using an optical head equipped with a semiconductor laser with a wavelength of 830 nm. At this time, in conventional optical discs, as shown in Figure 4, the innermost circumference of the disc (radius 30 m +
) and the outermost periphery (radius 60 .mu.m), the laser power required to record a circular bit with a diameter of 0.8 μm was 7 mW at the innermost periphery and 10 mW at the outermost periphery. Here, the pulse width was set to 6Qnsec. In other words, in conventional optical discs, a larger laser power is required toward the outer periphery of the disc. On the other hand, when using the optical disc according to the present invention, the laser power for recording bits with a diameter of 0.8 μm is approximately equal for both the innermost and outermost peripheries.
It was Vv'. Therefore, by using the optical disc according to the present invention, bits of the same size can always be recorded with a substantially constant laser power. Further, even when the type of recording film and the rotation speed are different, by appropriately adjusting the composition and film thickness of the SUS film, it is possible to obtain almost constant recording sensitivity over the entire surface of the disk.
〔実施例2〕
第5図は、本発明の一実施例である光磁気ディスフであ
る。5.25 インチのポリカーボネート基板1上に、
下地層6としてSiN膜を800人。[Embodiment 2] FIG. 5 shows a magneto-optical disk which is an embodiment of the present invention. On a 5.25 inch polycarbonate substrate 1,
800 SiN films as base layer 6.
記録膜7としてT b F e Co膜を300人、保
護膜8としてAl−Ti膜を200人、それぞれマグネ
トロンスパッタ法により形成した。このディスクを18
0Orpmで回転させ、記録を行ったところ、第4図と
同様に、ディスク内周から外周に渡って、はぼ一定の記
録感度を得た。また、第5図のディスク構造において、
T b F e Co膜とAl2−Ti膜との間にSi
N膜等の誘電体を挿入しても同様の結果が得られた。さ
らに、相変化型の光ディスクでも、下地層や保護層及び
中間層として、SUS膜あるいはAl合金膜を用いれば
、ディスク全面に渡ってほぼ一定の記録感度を得ること
ができる。A T b Fe Co film was formed as the recording film 7 by 300 people, and an Al-Ti film was formed by 200 people as the protective film 8 by magnetron sputtering. This disc is 18
When the disk was rotated at 0 rpm and recording was performed, almost constant recording sensitivity was obtained from the inner circumference to the outer circumference of the disk, as shown in FIG. Furthermore, in the disk structure shown in Fig. 5,
Si between the T b Fe Co film and the Al2-Ti film
Similar results were obtained even when a dielectric material such as an N film was inserted. Furthermore, even in a phase change type optical disc, by using a SUS film or an Al alloy film as the underlayer, protective layer, and intermediate layer, almost constant recording sensitivity can be obtained over the entire surface of the disc.
本発明による光記録媒体を用いれば、一定角速度で回転
するディスクの径方向に渡るすべての記録点において、
一定の記録感度を得ることができる。By using the optical recording medium according to the present invention, at all recording points in the radial direction of a disk rotating at a constant angular velocity,
A certain recording sensitivity can be obtained.
第1図、第5図は本発明の実施例である光記録媒体の断
面図、第2図はSUS膜及びAl合金膜における熱伝導
率の温度変化を示す特性図、第3図は従来の光記録媒体
の断面図、第4図は本発明の実施例および従来例の0.
8μm径のピット(記録点)を記録するのに要するレー
ザパワーの線速度依存性を示す特性図である。
1・・・ポリカーボネート基板、2・・・SUS膜、3
゜5・・・フッ素樹脂膜、4・・・Te膜、6・・・S
iN膜、′vJ l □□□
第 3 区
′fJ2の
韓X!a (声/、5et)
妬5 図
シミL贋(K)Figures 1 and 5 are cross-sectional views of optical recording media according to embodiments of the present invention, Figure 2 is a characteristic diagram showing temperature changes in thermal conductivity in SUS films and Al alloy films, and Figure 3 is a diagram of conventional optical recording media. FIG. 4 is a cross-sectional view of the optical recording medium, showing the embodiment of the present invention and the conventional example.
FIG. 2 is a characteristic diagram showing the linear velocity dependence of the laser power required to record a pit (recording point) with a diameter of 8 μm. 1... Polycarbonate substrate, 2... SUS film, 3
゜5...Fluororesin film, 4...Te film, 6...S
iN membrane,'vJ l □□□ 3rd ward'fJ2's Han X! a (voice/, 5et) Envy 5 Figure stain L fake (K)
Claims (1)
射して情報を記録あるいは消去する光記録媒体において
、記録膜の下地層あるいは保護層あるいは中間層として
、室温では熱伝導率が小さく高温で熱伝導率が大きくな
る材料を用いることを特徴とする光記録媒体。 2、上記下地層あるいは保護層あるいは中間層として、
SUS膜あるいはAl合金膜を用いることを特徴とする
光記録媒体。[Claims] 1. In an optical recording medium in which a recording film is provided on a predetermined substrate and information is recorded or erased by irradiating the recording film with light, as an underlayer, a protective layer, or an intermediate layer of the recording film. , an optical recording medium characterized by using a material that has a low thermal conductivity at room temperature and a high thermal conductivity at high temperatures. 2. As the base layer, protective layer or intermediate layer,
An optical recording medium characterized by using a SUS film or an Al alloy film.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2146241A JPH0440638A (en) | 1990-06-06 | 1990-06-06 | Optical recording medium |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2146241A JPH0440638A (en) | 1990-06-06 | 1990-06-06 | Optical recording medium |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0440638A true JPH0440638A (en) | 1992-02-12 |
Family
ID=15403295
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2146241A Pending JPH0440638A (en) | 1990-06-06 | 1990-06-06 | Optical recording medium |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0440638A (en) |
-
1990
- 1990-06-06 JP JP2146241A patent/JPH0440638A/en active Pending
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