JP2522979B2 - Optical recording medium - Google Patents
Optical recording mediumInfo
- Publication number
- JP2522979B2 JP2522979B2 JP63010412A JP1041288A JP2522979B2 JP 2522979 B2 JP2522979 B2 JP 2522979B2 JP 63010412 A JP63010412 A JP 63010412A JP 1041288 A JP1041288 A JP 1041288A JP 2522979 B2 JP2522979 B2 JP 2522979B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- optical recording
- recording medium
- dielectric multilayer
- multilayer 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.)
- Expired - Lifetime
Links
Landscapes
- Thermal Transfer Or Thermal Recording In General (AREA)
- Optical Record Carriers And Manufacture Thereof (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、基板上に積層された複数の光吸収剤層に記
録光を照射し、光学的信号を光吸収剤層に記録する光記
録媒体に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical recording in which a plurality of light absorbent layers laminated on a substrate are irradiated with recording light to record an optical signal in the light absorbent layer. It concerns media.
基板上に配された光吸収剤層に記録光を照射して該光
吸収剤層に光学的信号を記録するような記録方式は、経
年変化がなく記録保存性が良い、実時間で記録，再生が
可能である、記録密度が高密度である等の利点があり、
大容量記憶システム，画像ファイル等への応用が推し進
められている。また、記録密度を更に高めるように、記
録の多重化を図るべく、複数の光吸収剤層を積層した構
成を有する光記録媒体が提案されている（特開昭59−21
0543号公報）。The recording method of irradiating a recording light on the light absorbent layer arranged on the substrate to record an optical signal on the light absorbent layer is a record-keeping property which does not change with time and has a good record storability. It has the advantages of being reproducible and having a high recording density.
Applications to large-capacity storage systems and image files are being promoted. Further, an optical recording medium having a structure in which a plurality of light absorbent layers are laminated has been proposed in order to multiplex recording so as to further increase the recording density (JP-A-59-21).
0543).
第４図，第５図は特開昭59−210543号公報にて提案さ
れた光記録媒体の断面概略図であり、第４図に示す例
は、光（レーザビーム）の焦点位置を変化させることに
より、記録の多重化を可能にしたものであり、また第５
図に示す例は、光（レーザビーム）に対する特性吸収帯
が異なった複数の光吸収剤層を積層した構成として、記
録の多重化を可能にしたものである。4 and 5 are schematic cross-sectional views of an optical recording medium proposed in Japanese Patent Laid-Open No. 59-210543. In the example shown in FIG. 4, the focal position of light (laser beam) is changed. This makes it possible to multiplex the recording.
The example shown in the drawing is a structure in which a plurality of light absorbent layers having different characteristic absorption bands for light (laser beam) are laminated to enable multiplexing of recording.
第４図において41は基板であり、基板41上には、透明
な蒸着膜42,光吸収剤層43,透明な蒸着膜44,光吸収剤層4
5,透明な蒸着膜46がこの順に積層されている。なお、光
吸収剤層43及び光吸収剤層45は同材質である。かかる構
成において光吸収剤層43,光吸収剤層45に光記録を行う
場合、光吸収剤層43に記録するときには、光吸収剤層43
に焦点が合うレンズ47を使用し、また光吸収剤層45に記
録するときには、光吸収剤層45に焦点が合うレンズ48を
使用する。In FIG. 4, reference numeral 41 denotes a substrate, and on the substrate 41, a transparent vapor deposition film 42, a light absorbing agent layer 43, a transparent vapor deposition film 44, and a light absorbing agent layer 4 are provided.
5. The transparent vapor deposition film 46 is laminated in this order. The light absorber layer 43 and the light absorber layer 45 are made of the same material. In such a configuration, when optical recording is performed on the light absorbent layer 43 and the light absorbent layer 45, when recording on the light absorbent layer 43, the light absorbent layer 43
The lens 47 focused on the optical absorber layer 45 is used, and the lens 48 focused on the optical absorber layer 45 is used when recording on the optical absorber layer 45.
第５図において51は基板であって、基板51上には、５
層の透明な薄膜52,54,56,58,60及び４層の光吸収剤層5
3,55,57,59が、透明な薄膜，光吸収剤層を交互にして積
層されており、各光吸収剤層53,55,57,59は、光（レー
ザビーム）に対する特性吸収帯が夫々異なっている。従
って、各光吸収剤層にのみ吸収される波長を有する光源
を使用して、各光吸収剤層53,55,57,59夫々に光記録を
行う。In FIG. 5, 51 is a substrate, and 5 is on the substrate 51.
Layers of transparent thin films 52,54,56,58,60 and four layers of light absorber layer 5
3,55,57,59 are laminated by alternately laminating transparent thin films and light absorbent layers, and each light absorbent layer 53,55,57,59 has a characteristic absorption band for light (laser beam). They are different. Therefore, optical recording is performed on each of the light absorbent layers 53, 55, 57, 59 by using a light source having a wavelength that is absorbed only by each of the light absorbent layers.
ところが、第４図に示す例では、各光吸収剤層毎に対
応する開口率（NA）を有するレンズ（焦点距離が合った
レンズ）を用いる必要があり、装置構成が大嵩になると
いう難点があった。However, in the example shown in FIG. 4, it is necessary to use a lens (a lens having a matching focal length) having an aperture ratio (NA) corresponding to each light absorber layer, which makes the device configuration bulky. was there.
また第５図に示す例では、各光吸収剤層毎に焦点距離
が異なるレンズを用意する必要はないが、特殊な特性吸
収帯を有するような材料は少ないので、各光吸収剤層を
形成する実用的な材料を選択することが困難であるとい
う問題点があった。Further, in the example shown in FIG. 5, it is not necessary to prepare a lens having a different focal length for each light absorbent layer, but since there are few materials having a special characteristic absorption band, each light absorbent layer is formed. There is a problem that it is difficult to select a practical material to be used.
本発明はかかる事情に鑑みてなされたものであり、隣
合う光吸収剤層間に、所定の波長域の光のみを透過する
誘電体多層膜を設けることにより、簡単な装置構成にて
光記録を行うことができ、しかも光吸収剤層を形成する
材料を自由に選択できる光記録媒体を提供することを目
的とする。The present invention has been made in view of such circumstances, and by providing a dielectric multilayer film that transmits only light in a predetermined wavelength range between adjacent light absorber layers, optical recording can be performed with a simple device configuration. An object of the present invention is to provide an optical recording medium which can be used and which can freely select a material for forming a light absorber layer.
本発明に係る光記録媒体は、記録光を吸収して情報を
記録する光吸収剤層を複数層積層してある光記録媒体に
おいて、隣合う光吸収剤層間に、所定の波長域の記録光
を透過し、他の波長域の記録光を反射する誘電体多層膜
を設けてあることを特徴とする。The optical recording medium according to the present invention is an optical recording medium in which a plurality of optical absorbent layers that absorb recording light to record information are laminated, and recording light of a predetermined wavelength range is provided between adjacent optical absorbent layers. Is provided, and a dielectric multilayer film that transmits recording light in other wavelength ranges is reflected.
本発明の光記録媒体にあっては、隣合う光吸収剤層間
に、所定の波長域の光のみを透過する誘電体多層膜が設
けてあるので、該誘電体多層膜の下層にある光吸収剤層
に対して、この所定の波長域の光にて選択的に情報を記
録する。そうすると各光吸収剤層において異なる所定の
波長域の光にて情報を記録するので、各光吸収剤層にお
いて、他の光吸収剤層への光記録に影響されることな
く、独立的に情報を記録することができ、光記録の多重
化が可能である。In the optical recording medium of the present invention, since the dielectric multilayer film that transmits only the light in the predetermined wavelength range is provided between the adjacent light absorbent layers, the light absorption layer below the dielectric multilayer film is absorbed. Information is selectively recorded on the agent layer with light in this predetermined wavelength range. Then, since information is recorded with light of different predetermined wavelength ranges in each light absorbent layer, information is independently recorded in each light absorbent layer without being affected by optical recording in other light absorbent layers. Can be recorded, and optical recording can be multiplexed.
以下、本発明をその実施例を示す図面に基づき具体的
に説明する。Hereinafter, the present invention will be specifically described with reference to the drawings illustrating the embodiments.
第１図は本発明に係る光記録媒体の構造を示す断面概
略図であり、図中１は透明ガラスからなる基板を示す。
基板１上にレーザビームを反射するための薄層のA1膜２
が積層されており、該A1膜２上には、Gd2BiFe5O12（屈
折率:2.2）からなる第１の光吸収剤層３が積層されてい
る。また該第１の光吸収剤層３上には、SiO2膜,a−Si膜
を交互に積層形成してなる誘電体多層膜４が積層されて
いる。FIG. 1 is a schematic cross-sectional view showing the structure of an optical recording medium according to the present invention, in which 1 denotes a substrate made of transparent glass.
Thin A1 film 2 for reflecting laser beam on substrate 1
Is laminated, and a first light absorber layer 3 made of Gd 2 BiFe 5 O 12 (refractive index: 2.2) is laminated on the A1 film 2. Further, on the first light absorber layer 3, a dielectric multilayer film 4 formed by alternately laminating SiO 2 films and a-Si films is laminated.
誘電体多層膜４は、SiO2膜4a及びａ−Si膜4bを１層ず
つ交互に５対だけ成膜された構成をなす。なお、SiO2膜
4a,a−Si膜4bの各膜厚は夫々1577Å,773Åであり、ま
た、SiO2膜4a,a−Si膜4bの各屈折率は夫々1.46,3.0であ
る。なお、このような構成を有する誘電体多層膜４を作
製するための成膜技法としては、スパッタリング法を用
いる。The dielectric multilayer film 4 has a structure in which one pair of SiO 2 films 4a and a-Si films 4b are alternately formed to form five pairs. In addition, SiO 2 film
The film thicknesses of the 4a and a-Si films 4b are 1577Å and 773Å, respectively, and the refractive indexes of the SiO 2 film 4a and a-Si film 4b are 1.46 and 3.0, respectively. A sputtering method is used as a film forming technique for forming the dielectric multilayer film 4 having such a configuration.
第２図は、この誘電体多層膜４における反射率特性を
示すグラフであり、第２図において横軸は照射する光の
波長（nm）を示し、縦軸は反射率（％）を示す。第２図
のグラフから理解される如く、誘電体多層膜４は、波長
が680nm近傍である光を略100％透過し、波長が800nm以
上である光を略100％反射する。FIG. 2 is a graph showing the reflectance characteristic of the dielectric multilayer film 4. In FIG. 2, the horizontal axis shows the wavelength (nm) of the light to be irradiated, and the vertical axis shows the reflectance (%). As understood from the graph of FIG. 2, the dielectric multilayer film 4 transmits almost 100% of light having a wavelength of about 680 nm and reflects substantially 100% of light having a wavelength of 800 nm or more.
誘電体多層膜４上には、EuO（屈折率:1.5）からなる
第２の光吸収剤層５が積層されている。更に、第２の光
吸収剤層５上には、透明な保護膜６が積層形成されてい
る。A second light absorber layer 5 made of EuO (refractive index: 1.5) is laminated on the dielectric multilayer film 4. Further, a transparent protective film 6 is laminated on the second light absorber layer 5.
本発明の光記録媒体は以上のように構成されている。
次に、本発明の光記録媒体に記録光を照射して情報を記
録する動作について説明する。The optical recording medium of the present invention is configured as described above.
Next, an operation of irradiating the optical recording medium of the present invention with recording light to record information will be described.
第３図は本発明の光記録媒体に情報を記録する実施状
態を示す模式図であり、図中10は前述したような構造を
有する本発明の光記録媒体である。光記録媒体10の上方
には、光記録媒体10（保護膜６）から等距離に、光源で
ある２個の半導体レーザ21,31が、相互に適長離隔して
設けられている。半導体レーザ21はGaInP系の半導体レ
ーザであって、その発振波長は680nmであり、一方、半
導体レーザ31はGaAIAs系の半導体レーザであって、その
発振波長は830nmである。FIG. 3 is a schematic view showing an implementation state in which information is recorded on the optical recording medium of the present invention. In the figure, 10 is the optical recording medium of the present invention having the structure as described above. Two semiconductor lasers 21 and 31, which are light sources, are provided above the optical recording medium 10 at equal distances from the optical recording medium 10 (protective film 6) and spaced from each other by an appropriate length. The semiconductor laser 21 is a GaInP-based semiconductor laser with an oscillation wavelength of 680 nm, while the semiconductor laser 31 is a GaAIAs-based semiconductor laser with an oscillation wavelength of 830 nm.
光記録媒体10と２個の半導体レーザ21,31との間に
は、半導体レーザ21,31側から順に、半導体レーザ21,31
から出射されたレーザビームを透過し、光記録媒体10か
らの戻り光を90゜変向する偏光ビームスプリッタ13、偏
光ビームスプリッタ13を透過したレーザビームを光吸収
剤層に集光させる対物レンズ14が設けられている。ま
た、光記録媒体10から戻り、偏光ビームスプリッタ13に
て反射された光を受光する２個のフォトダイオード22,3
2が、各レーザビームの反射光進路方向に設けられてい
る。Between the optical recording medium 10 and the two semiconductor lasers 21 and 31, the semiconductor lasers 21 and 31 are arranged in order from the semiconductor lasers 21 and 31 side.
A polarization beam splitter 13 that transmits the laser beam emitted from the optical recording medium 10 and redirects the return light from the optical recording medium 10 by 90 °, and an objective lens 14 that condenses the laser beam transmitted through the polarization beam splitter 13 on a light absorbing layer. Is provided. Also, two photodiodes 22 and 3 that return from the optical recording medium 10 and receive the light reflected by the polarization beam splitter 13.
2 is provided in the reflected light traveling direction of each laser beam.
半導体レーザ21,31を出射したレーザビームは、偏光
ビームスプリッタ13,対物レンズ14を透過し、光記録媒
体10を照射する。光記録媒体10から戻るレーザビーム
は、偏光ビームスプリッタ13にて反射されてその進路方
向が90゜変向され、フォトダイオード22,32に受光され
る。そして、フォトダイオード22,32にて受光されるレ
ーザビームの強度に基づいて、対応する各半導体レーザ
21,31の出力を制御する。なお、第３図ではこの制御系
の図示は省略している。The laser beams emitted from the semiconductor lasers 21 and 31 pass through the polarization beam splitter 13 and the objective lens 14 and irradiate the optical recording medium 10. The laser beam returning from the optical recording medium 10 is reflected by the polarization beam splitter 13, its path direction is changed by 90 °, and is received by the photodiodes 22 and 32. Then, based on the intensity of the laser beam received by the photodiodes 22 and 32, the corresponding semiconductor laser
Controls the output of 21,31. The control system is not shown in FIG.
次に、光記録の具体的動作について説明する。 Next, a specific operation of optical recording will be described.
半導体レーザ21からは波長が680nmであるレーザビー
ム（記録光）を出射し（第３図実線矢符参照）、光記録
媒体10内を照射する。このレーザビームは、保護膜６及
び第２の光吸収剤層５を透過する。誘電体多層膜４は前
述したように、波長が680nm近傍である光を略100％透過
するので、このレーザビームは該誘電体多層膜４を透過
し、第１の光吸収剤層３にて集光され、第１の光吸収剤
層３に情報が記録される。A laser beam (recording light) having a wavelength of 680 nm is emitted from the semiconductor laser 21 (see solid line arrow in FIG. 3) to irradiate the inside of the optical recording medium 10. This laser beam passes through the protective film 6 and the second light absorber layer 5. As described above, the dielectric multilayer film 4 transmits almost 100% of the light having a wavelength in the vicinity of 680 nm. Therefore, this laser beam passes through the dielectric multilayer film 4, and the first light absorber layer 3 transmits the laser beam. The light is collected and information is recorded on the first light absorber layer 3.
一方、半導体レーザ31からは波長が830nmであるレー
ザビーム（記録光）を出射し（第３図破線矢符参照）、
光記録媒体10内を照射する。ところが、誘電体多層膜４
は前述したように波長が800nm以上である光を略100％反
射するので、このレーザビームは該誘電体多層膜４にて
上方に反射され、第２の光吸収剤層５にて集光され、第
２の光吸収剤層５に情報が記録される。On the other hand, a laser beam (recording light) having a wavelength of 830 nm is emitted from the semiconductor laser 31 (see the broken line arrow in FIG. 3),
The inside of the optical recording medium 10 is irradiated. However, the dielectric multilayer film 4
As described above, almost 100% of light having a wavelength of 800 nm or more is reflected, so that this laser beam is reflected upward by the dielectric multilayer film 4 and is condensed by the second light absorber layer 5. , Information is recorded on the second light absorber layer 5.
以上詳述した如く、本発明の光記録媒体は記録用のレ
ーザビームの波長を選択することにより、任意の光吸収
剤層に対して、情報を記録することができる。その結
果、光吸収剤層の材料として特殊な材料を選択すること
が不要となり、材料選択の自由度が増大する。As described above in detail, in the optical recording medium of the present invention, information can be recorded in any light absorbent layer by selecting the wavelength of the laser beam for recording. As a result, it becomes unnecessary to select a special material as the material of the light absorber layer, and the degree of freedom in material selection increases.
また、焦点距離が異なるレンズを多数用いる必要がな
いので、光記録を行う際の装置構成が小型化する等、本
発明は優れた効果を奏する。Further, since it is not necessary to use a large number of lenses having different focal lengths, the present invention has excellent effects such as downsizing of the device configuration for optical recording.
なお、本実施例では２層の光吸収剤層を設けることと
したが、これに限らず、隣合う光吸収剤層間に所定の波
長域の光のみを透過する誘電体多層膜を挟み込む構成と
する場合にあっては、３層以上の光吸収剤層を設ける構
成としても同様の効果が得られることは勿論である。In the present embodiment, two light absorbing agent layers are provided, but the present invention is not limited to this, and a structure in which a dielectric multilayer film that transmits only light in a predetermined wavelength range is sandwiched between adjacent light absorbing agent layers. In such a case, it goes without saying that the same effect can be obtained even if three or more light absorber layers are provided.
第１図は本発明の光記録媒体の断面概略図、第２図は誘
電体多層膜の反射率特性を示すグラフ、第３図は本発明
の光記録媒体における記録動作の実施を示す模式図、第
４図，第５図は従来の光記録媒体の断面概略図である。 １……基板、２……A1膜、３……第１の光吸収剤層、４
……誘電体多層膜、５……第２の光吸収剤層、10……光
記録媒体、21,31……半導体レーザFIG. 1 is a schematic cross-sectional view of an optical recording medium of the present invention, FIG. 2 is a graph showing the reflectance characteristics of a dielectric multilayer film, and FIG. 3 is a schematic diagram showing the recording operation of the optical recording medium of the present invention. FIGS. 4 and 5 are schematic cross-sectional views of a conventional optical recording medium. 1 ... Substrate, 2 ... A1 film, 3 ... First light absorber layer, 4
...... Dielectric multilayer film, 5 …… Second light absorber layer, 10 …… Optical recording medium, 21,31 …… Semiconductor laser
Claims (1)
層を複数層積層してある光記録媒体において、 隣合う光吸収剤層間に、所定の波長域の記録光を透過
し、他の波長域の記録光を反射する誘電体多層膜を設け
てあることを特徴とする光記録媒体。1. An optical recording medium in which a plurality of light absorbing layers for recording information by absorbing recording light are laminated, wherein recording light in a predetermined wavelength range is transmitted between adjacent light absorbing layers, An optical recording medium comprising a dielectric multilayer film that reflects recording light in other wavelength ranges.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63010412A JP2522979B2 (en) | 1988-01-19 | 1988-01-19 | Optical recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63010412A JP2522979B2 (en) | 1988-01-19 | 1988-01-19 | Optical recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01184738A JPH01184738A (en) | 1989-07-24 |
| JP2522979B2 true JP2522979B2 (en) | 1996-08-07 |
Family
ID=11749433
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63010412A Expired - Lifetime JP2522979B2 (en) | 1988-01-19 | 1988-01-19 | Optical recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2522979B2 (en) |
-
1988
- 1988-01-19 JP JP63010412A patent/JP2522979B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01184738A (en) | 1989-07-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4022412B2 (en) | Composite reflection prism and optical pickup device using the same | |
| KR100477259B1 (en) | Wavelength selective element for limiting opening, wavelength selective beam splitter, and optical pickup apparatus equipped therewith | |
| JP2644829B2 (en) | Optical information recording / reproducing device | |
| RU97116835A (en) | MULTI-LAYER OPTICAL DISC DRIVE SYSTEM WITH FIXED ABERRATION CORRECTION AND OPTIMAL INTERLAYER DISTANCE | |
| JPS63191327A (en) | Solid-state optical pickup | |
| US4545651A (en) | Optical system for synthesizing plural light beams | |
| JP4084660B2 (en) | Optical recording medium and optical recording / reproducing method | |
| JP2988732B2 (en) | Information recording / reproducing device | |
| JP3635516B2 (en) | Optical disk device | |
| JP2522979B2 (en) | Optical recording medium | |
| JP2710809B2 (en) | Crossed diffraction grating and polarization rotation detector using the same | |
| JPH01282756A (en) | Optical pickup | |
| JP3837902B2 (en) | Optical pickup device | |
| JPH09145922A (en) | Optical element for diffraction and optical pickup device using the same | |
| JPH04325936A (en) | Beam splitter for optical head | |
| JP3077426B2 (en) | Optical information recording / reproducing device | |
| JP2996856B2 (en) | Optical pickup device | |
| JP3393680B2 (en) | Optical pickup | |
| JPS61292235A (en) | Optical head | |
| JPS63142546A (en) | Wavelength multiplex optical recording medium | |
| JPH08271712A (en) | Optical element and optical integrated circuit | |
| JPS62271236A (en) | Optical disk device | |
| JP2001084625A (en) | Optical information recording/reproducing device | |
| JP2004013988A (en) | Focal control method and optical recording medium initialization device using the same | |
| JPH0464931A (en) | Optical pickup device using wavelength multiple recording system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080531 Year of fee payment: 12 |