JPH0673203B2 - Light pickup - Google Patents
Light pickupInfo
- Publication number
- JPH0673203B2 JPH0673203B2 JP61220720A JP22072086A JPH0673203B2 JP H0673203 B2 JPH0673203 B2 JP H0673203B2 JP 61220720 A JP61220720 A JP 61220720A JP 22072086 A JP22072086 A JP 22072086A JP H0673203 B2 JPH0673203 B2 JP H0673203B2
- Authority
- JP
- Japan
- Prior art keywords
- hologram
- magneto
- optical disk
- optical
- light
- 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
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10532—Heads
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10532—Heads
- G11B11/10541—Heads for reproducing
- G11B11/10543—Heads for reproducing using optical beam of radiation
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B33/00—Constructional parts, details or accessories not provided for in the other groups of this subclass
- G11B33/14—Reducing influence of physical parameters, e.g. temperature change, moisture, dust
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/123—Integrated head arrangements, e.g. with source and detectors mounted on the same substrate
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Mechanical Optical Scanning Systems (AREA)
Description
【発明の詳細な説明】 〔概要〕 光源から発生した光を光磁気ディスク側に集束するホロ
グラム、光磁気ディスクからの反射信号光を光検知器側
に回折するホログラム、該ホログラムで回折された光を
２つの光検知器に分配するホログラムとで、光ピックア
ップの光学系を構成し、光ピックアップの小型、軽量化
を実現する。DETAILED DESCRIPTION [Outline] A hologram that focuses light generated from a light source on the magneto-optical disk side, a hologram that diffracts reflected signal light from the magneto-optical disk to the photodetector side, and light diffracted by the hologram And a hologram that distributes the light to two photodetectors, form an optical system of the optical pickup, and realize the downsizing and weight reduction of the optical pickup.
情報処理システムにおける大容量記憶装置として、書換
え可能な光磁気ディスク及び光磁気ディスク用のヘッド
の研究開発が盛んに進められている。本発明は、後者の
光磁気ディスク用ヘッドに使用される光ピックアップに
関する。As a large-capacity storage device in an information processing system, research and development of a rewritable magneto-optical disk and a head for the magneto-optical disk have been actively pursued. The present invention relates to an optical pickup used in the latter magneto-optical disk head.
第５図は従来の情報を書替え可能な光磁気ディスク用の
光ピックアップを示す側面図である。レーザ光源LDから
発した直線偏光は、群レンズから成るコリメートレンズ
１で平行光に変換されてビームスプリッタ２を透過し、
対物レンズ３で光磁気ディスク４に集束される。光磁気
ディスク４からの反射光は、光磁気ディスク４における
光束の照射部の磁化の方向に応じて偏光面が回転し、対
物レンズ３で平行光３に変換された後、ビームスプリッ
タ２で1/2波長板７側に反射される。そして1/2波長板７
で偏光面が回転された後、レンズ５で絞られ、偏光ビー
ムスプリッタ６を介して一部は光検知器D1に集束され、
他の一部は別の光検知器D2に反射集束される。このよう
に２つの光検知器D1、D2で検知し、両光検知器D1、D2の
出力の差によって、光磁気ディスク４における情報が読
み取られる。FIG. 5 is a side view showing a conventional optical pickup for a magneto-optical disk capable of rewriting information. The linearly polarized light emitted from the laser light source LD is converted into parallel light by the collimator lens 1 composed of a group lens and transmitted through the beam splitter 2,
It is focused on the magneto-optical disk 4 by the objective lens 3. The reflected light from the magneto-optical disk 4 has its plane of polarization rotated according to the direction of magnetization of the irradiation portion of the light flux on the magneto-optical disk 4, is converted into parallel light 3 by the objective lens 3, and is then converted by the beam splitter 2 into 1 / 2 Reflected on the wave plate 7 side. And 1/2 wave plate 7
After the plane of polarization is rotated by, the light is focused by the lens 5, and a part is focused on the photodetector D1 via the polarization beam splitter 6.
The other part is reflected and focused on another photodetector D2. In this way, the two photodetectors D1 and D2 detect, and the information on the magneto-optical disk 4 is read by the difference between the outputs of the photodetectors D1 and D2.
このように従来の光磁気ディスク用光ピックアップは、
多数の光学素子で構成されており、アクチュエータを含
めたヘッド全体の重量が数十グラムと重い。光磁気ディ
スク装置を従来の磁気ディスクに代えて、コードデータ
の記憶装置として用いるためには、高速アクセスを可能
とする必要があるが、前記のような従来の光ピックアッ
プは、大型でかつ重量が大きく、高速アクセスに適しな
い。In this way, the conventional optical pickup for magneto-optical disk is
It is composed of many optical elements, and the weight of the entire head including the actuator is as heavy as several tens of grams. In order to use the magneto-optical disk device as a storage device for code data in place of the conventional magnetic disk, it is necessary to enable high-speed access. However, the conventional optical pickup as described above is large and heavy. Large and not suitable for high speed access.
本発明の技術的課題は、光磁気ディスク用の光ピックア
ップにおけるこのような問題を解消し、小型、軽量化を
実現し、アクセス時間を短縮可能とすることにある。A technical object of the present invention is to solve such a problem in an optical pickup for a magneto-optical disk, realize a small size and a light weight, and shorten an access time.
第１図は本発明による光ピックアップの基本原理を説明
する側面図である。LDはレーザ光源、４は光磁気ディス
クであり、レーザ光源LDと光磁気ディスク４と間に、第
１のホログラムH1と第２のホログラムH2から成る２枚の
ホログラムが配設されている。この２枚のホログラムH
1、H2のうち、片方のホログラムは、前記光源LDから光
磁気ディスク４へ向かう光波を光磁気ディスクの１点に
集束するものであり、もう１枚のホログラムは、光磁気
ディスク４からの反射信号光を光検知器側に回折するも
のであり、両ホログラムは、重ねて配置されている。FIG. 1 is a side view for explaining the basic principle of the optical pickup according to the present invention. LD is a laser light source, and 4 is a magneto-optical disk, and two holograms composed of a first hologram H1 and a second hologram H2 are arranged between the laser light source LD and the magneto-optical disk 4. These two holograms H
One of the holograms H and H2 focuses the light wave traveling from the light source LD to the magneto-optical disk 4 at one point on the magneto-optical disk, and the other hologram reflects from the magneto-optical disk 4. The signal light is diffracted to the photodetector side, and both holograms are arranged in an overlapping manner.
また両ホログラムH1、H2と２つの光検知器D1、D2との間
に、信号光を両光検知器D1、D2へ導くための偏光分離機
能を有する第３のホログラムH3が、配設されている。Further, a third hologram H3 having a polarization separation function for guiding the signal light to both photodetectors D1 and D2 is provided between both holograms H1 and H2 and two photodetectors D1 and D2. There is.
第１図において、レーザ光源LDから出照したコヒーレン
ト光に対し、第１のホログラムH1は、ブラッグ角から外
れた角度で配置されているため、該コヒーレント光は、
第１のホログラムH1を透過し、第２のホログラムH2で、
光磁気ディスク４に集束される。このとき、レーザ光の
偏光方向を紙面内にとり、第２のホログラムH2に対して
Ｐ偏光入射とすることにより、ビーム径整形が行なわれ
る。光磁気ディスク４においてカー効果を受けた反射信
号光のうち、第２のホログラムH2を透過したものは、第
１のホログラムH1により回折を受けて分離され、検知器
D2に向けて集束しながら、第３のホログラムH3に入射す
る。第３のホログラムH3は、偏光分離機能を有するの
で、カー効果が無い場合は、Ｐ成分とＳ成分が等量に分
離され、回折した光が検知器D1に向けて集束するように
設定される。Ｐ成分、Ｓ成分のいずれを回折させるか
は、第３のホログラムH3の作成法により変えることがで
きる。また第３のホログラムH3の作成法を工夫すること
によって、検知器D1でフォーカス方向およびトラック方
向のずれを検知することもできる。In FIG. 1, since the first hologram H1 is arranged at an angle deviating from the Bragg angle with respect to the coherent light emitted from the laser light source LD, the coherent light is
Through the first hologram H1 and the second hologram H2,
It is focused on the magneto-optical disk 4. At this time, the beam diameter is shaped by setting the polarization direction of the laser light in the plane of the paper and making the P-polarized light incident on the second hologram H2. Of the reflected signal light that has undergone the Kerr effect in the magneto-optical disk 4, that that has passed through the second hologram H2 is diffracted by the first hologram H1 and separated, and
While focusing toward D2, it is incident on the third hologram H3. Since the third hologram H3 has a polarization separation function, when there is no Kerr effect, the P component and the S component are separated into equal amounts, and the diffracted light is set to be focused toward the detector D1. . Which of the P component and the S component is diffracted can be changed by the method of forming the third hologram H3. Further, by devising the method of forming the third hologram H3, the detector D1 can detect the deviation in the focus direction and the track direction.
次に本発明による光ピックアップが実際上どのように具
体化されるかを実施例で説明する。第２図は本発明によ
る光ピックアップの分解斜視図である。第１のホログラ
ムH1と第２のホログラムH2は、実際には重なっており、
接近しているが、理解を容易にするために、離して描か
れている。光磁気ディスク４で反射された光は、カー効
果で回転を受けＳ成分を含むが、このＳ成分を有効に検
出できるように、第２のホログラムH2は、Ｓ偏光が透過
し易いように作成される。またレーザ光源LDから入射し
たＰ偏光は、効果的に光磁気ディスク４側に回折するよ
うに作成される。Next, practical examples of how the optical pickup according to the present invention is embodied will be described. FIG. 2 is an exploded perspective view of the optical pickup according to the present invention. The first hologram H1 and the second hologram H2 actually overlap,
They are close together but are drawn apart for ease of understanding. The light reflected by the magneto-optical disk 4 is rotated by the Kerr effect and contains an S component, but the second hologram H2 is made so that S polarized light is easily transmitted so that this S component can be effectively detected. To be done. Further, the P-polarized light incident from the laser light source LD is created so as to be effectively diffracted toward the magneto-optical disk 4 side.
３つのホログラムH1、H2、H3には、格子縞が示されてい
るが、第３のホログラムH3は、その格子縞８が、ｘ、ｙ
軸に対し45度傾けて配置されている。光磁気ディスク４
においてカー効果を受けた反射光は、偏光面が回転する
ので、格子縞８を通過する際に、格子縞８における透過
量と反射量がアンバランスし、２つの検知器D1、D2によ
って、情報を読み取ることができる。Lattice stripes are shown on the three holograms H1, H2, and H3, but in the third hologram H3, the lattice stripes 8 are x and y.
It is placed at an angle of 45 degrees to the axis. Magneto-optical disk 4
Since the plane of polarization of the reflected light that has received the Kerr effect in (1) rotates, when passing through the lattice fringe 8, the amount of transmission and the amount of reflection in the lattice fringe 8 are unbalanced, and the information is read by the two detectors D1 and D2. be able to.
第３図は各ホログラムH1、H2、H3の機能および作成法を
示す図である。（ａ）は第１のホログラムH1に関する図
であり、このホログラムH1は、光磁気ディスク４上の点
Ｐからの発散波を検知器D2へ向けて集束する機能を有す
る。破線で示したレーザ光はブラッグ角が大きく外れて
いることによって、容易に透過させることができる。FIG. 3 is a diagram showing the functions of the holograms H1, H2, and H3 and the method of making them. (A) is a diagram relating to the first hologram H1, hologram H 1 has a function of converging towards a diverging wave from a point P on the magneto-optical disk 4 to the detector D 2. The laser light shown by the broken line can be easily transmitted because the Bragg angle is largely deviated.
このホログラムH1を作製するには、１点Ｐから発散する
球面波と１点D2に集束する球面波９を照射し、干渉露
光、現像する。To produce this hologram H1, a spherical wave diverging from one point P and a spherical wave 9 focusing on one point D2 are irradiated, and interference exposure and development are performed.
（ｂ）に示す第２のホログラムH2は、レーザ光源LDから
の発散波を所定の効率（例えば60％）で、光磁気ディス
ク４上の点Ｐに向けて集束させる機能を有する。また点
Ｐからの反射信号光（破線）に、第２のホログラムH2を
通過する成分をもたせる。このホログラムH2を作製する
には、１点Ｐから発散する球面波と１点LDに集束する球
面波10を照射し、干渉露光、現像する。The second hologram H 2 shown in (b) has a function of focusing the divergent wave from the laser light source LD toward the point P on the magneto-optical disk 4 with a predetermined efficiency (for example, 60%). In addition, the reflected signal light (broken line) from the point P has a component that passes through the second hologram H 2 . To produce this hologram H2, a spherical wave diverging from one point P and a spherical wave 10 focused on one point LD are irradiated, and interference exposure and development are performed.
（ｃ）に示す第３のホログラムH3は、第１のホログラム
H1で回折を受けて検知器D2に集束する光のＰ成分または
Ｓ成分を、別の検知器D1に集束させる偏光分離ホログラ
ムである。このホログラムH3は、１点D2に集束する球面
波11と１点D1に集束する球面波12を照射し、干渉露光、
現像する。The third hologram H3 shown in (c) is the first hologram H3.
It is a polarization separation hologram that focuses the P component or S component of the light that is diffracted by H1 and is focused on the detector D 2 to another detector D 1 . This hologram H3 irradiates a spherical wave 11 focused on one point D2 and a spherical wave 12 focused on one point D1 to perform interference exposure,
develop.
これらの光学系は、第４図に示すようにして一体化され
る。13は金属のケーシングであり、光磁気ディスク４に
対向する正面に形成された開口14に、前記の第２のホロ
グラムH2と第１のホログラムH1が重ねて挿入されてい
る。そして両ホログラムH1、H2に向けてコヒーレント光
を照射する半導体レーザLDが、ケーシング13の底部内面
に取りつけられている。この半導体レーザLDの取りつけ
位置の背面には、放熱用のフィン15を有するペルチエ素
子16が取りつけられ、半導体レーザLDの温度を一定に保
って、発振波長を安定化している。また金属ケーシング
13全体がレーザ光源LDのヒートシンクも兼ねている。光
検知器D2とD1は、ケーシング底部内面に取りつけられ、
該光検知器D2と前記２枚のホログラムH1、H2との間に、
ガラス板17に支持された第３のホログラムH3が配置され
ている。These optical systems are integrated as shown in FIG. Reference numeral 13 is a metal casing, and the second hologram H2 and the first hologram H1 described above are inserted in an opening 14 formed on the front surface facing the magneto-optical disk 4 in an overlapping manner. A semiconductor laser LD that irradiates the holograms H1 and H2 with coherent light is attached to the inner surface of the bottom of the casing 13. A Peltier element 16 having fins 15 for heat radiation is attached to the back surface of the mounting position of the semiconductor laser LD, and the temperature of the semiconductor laser LD is kept constant to stabilize the oscillation wavelength. Also metal casing
The entire 13 also serves as a heat sink for the laser light source LD. The photo detectors D2 and D1 are mounted on the inner surface of the bottom of the casing,
Between the photodetector D2 and the two holograms H1 and H2,
A third hologram H3 supported by the glass plate 17 is arranged.
このように、光学系が中空の金属ケーシング13中に密封
されているので、取扱いも簡便である。また、光学素子
はすべてホログラムから成り、極めて軽量なので、金属
ケーシング13の壁厚も薄くすることができ、小型、軽量
化に適している。In this way, the optical system is sealed in the hollow metal casing 13, so that it is easy to handle. Further, since all the optical elements are holograms and are extremely lightweight, the wall thickness of the metal casing 13 can be made thin, which is suitable for reduction in size and weight.
なお３つのホログラムH1、H2、H3は、表面レリーフ型、
位相型のいずれでもよい。The three holograms H1, H2 and H3 are surface relief type,
Either phase type may be used.
以上のように本発明によれば、光ピックアップの総ての
光学系が３枚のホログラムH1、H2、H3で構成されている
ため、光ヘッドの小型、軽量化を容易に実現でき、光磁
気ディスクにおける情報の記録／再生を高速に行なうこ
とが可能となる。As described above, according to the present invention, since all the optical systems of the optical pickup are composed of three holograms H1, H2, and H3, the optical head can be easily made small and lightweight, and It is possible to record / reproduce information on the disc at high speed.
第１図は本発明による光ピックアップの基本原理を説明
する側面図、第２図は本発明の実施例を示す分解斜視
図、第３図は各ホログラムの機能と作製法を示す図、第
４図は光ピックアップを一体化した例を示す断面図、第
５図は従来の光ピックアップを示す側面図である。 図において、LDはレーザ光源、H1は第１のホログラム、
H2は第２のホログラム、H3は第３のホログラム、D1、D2
は光検知器、４は光磁気ディスク、13は金属ケーシング
をそれぞれ示す。FIG. 1 is a side view for explaining the basic principle of the optical pickup according to the present invention, FIG. 2 is an exploded perspective view showing an embodiment of the present invention, FIG. 3 is a view showing the function and manufacturing method of each hologram, and FIG. FIG. 5 is a sectional view showing an example in which an optical pickup is integrated, and FIG. 5 is a side view showing a conventional optical pickup. In the figure, LD is a laser light source, H1 is the first hologram,
H2 is the second hologram, H3 is the third hologram, D1, D2
Is a photodetector, 4 is a magneto-optical disk, and 13 is a metal casing.
フロントページの続き (72)発明者 稲垣 雄史 神奈川県川崎市中原区上小田中1015番地 富士通株式会社内 (56)参考文献 特開 昭60−28044（ＪＰ，Ａ)Front page continuation (72) Inventor Yufumi Inagaki 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (56) Reference JP-A-60-28044 (JP, A)
Claims (2)
グラムにより光学系を構成してなる光磁気ディスク用の
光ピックアップであって、 前記光源（LD）から光磁気ディスク（４）へ向かう光波
を光磁気ディスク（４）に集束するホログラムと、光磁
気ディスク（４）からの反射信号光を光検知器側に回折
するホログラムとを重ねて配置し、 さらに信号光を２つの光検知器へ導くための偏光分離機
能を有する第３のホログラム（H3）を、前記２枚のホロ
グラムと２つの検知器（D1）（D2）との間に設けたこと
を特徴とする光ピックアップ。1. An optical pickup for a magneto-optical disk comprising an optical system including a coherent light source, a photodetector, and three holograms, the optical wave traveling from the light source (LD) to the magneto-optical disk (4). Is placed on the magneto-optical disk (4) and a hologram for diffracting the reflected signal light from the magneto-optical disk (4) to the photodetector side is arranged so as to overlap the signal light to two photodetectors. An optical pickup characterized in that a third hologram (H3) having a polarization separation function for guiding is provided between the two holograms and two detectors (D1) (D2).
ら成り、一体保持されると共に、金属ケーシングが光源
の温度調節手段を兼ねていることを特徴とする特許請求
の範囲第（１）項記載の光ピックアップ。2. The optical system holding means is composed of a metal casing and is integrally held, and the metal casing also serves as a temperature adjusting means of the light source. Optical pickup.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61220720A JPH0673203B2 (en) | 1986-09-18 | 1986-09-18 | Light pickup |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61220720A JPH0673203B2 (en) | 1986-09-18 | 1986-09-18 | Light pickup |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6374149A JPS6374149A (en) | 1988-04-04 |
| JPH0673203B2 true JPH0673203B2 (en) | 1994-09-14 |
Family
ID=16755459
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61220720A Expired - Lifetime JPH0673203B2 (en) | 1986-09-18 | 1986-09-18 | Light pickup |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0673203B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02120091A (en) * | 1988-10-28 | 1990-05-08 | Unitika Ltd | Printing screen |
| JP2687606B2 (en) * | 1989-07-19 | 1997-12-08 | 松下電器産業株式会社 | Optical pickup |
| FR2669744B1 (en) * | 1990-11-23 | 1994-03-25 | Thomson Csf | LIGHTING DEVICE AND APPLICATION TO A VISUALIZATION DEVICE. |
| US5581523A (en) * | 1992-11-17 | 1996-12-03 | Seiko Epson Corporation | Laser emission unit, optical head and optical memory device |
| JPH07176095A (en) * | 1993-06-25 | 1995-07-14 | Nec Corp | Magneto-optical head device |
-
1986
- 1986-09-18 JP JP61220720A patent/JPH0673203B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6374149A (en) | 1988-04-04 |
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