JPS60251533A - Detecting device of optical information - Google Patents
Detecting device of optical informationInfo
- Publication number
- JPS60251533A JPS60251533A JP59106200A JP10620084A JPS60251533A JP S60251533 A JPS60251533 A JP S60251533A JP 59106200 A JP59106200 A JP 59106200A JP 10620084 A JP10620084 A JP 10620084A JP S60251533 A JPS60251533 A JP S60251533A
- Authority
- JP
- Japan
- Prior art keywords
- light
- optical information
- half mirror
- objective lens
- error rate
- 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
Classifications
-
- 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
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1381—Non-lens elements for altering the properties of the beam, e.g. knife edges, slits, filters or stops
-
- 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
-
- 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
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Head (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は光磁気ディスク装置における光情報検出装置に
関するものである。近年、書き換え可能な光ディスクと
して、注目を集めている光磁気ディスクは実用化にあと
一歩というところまで開発さｎてきている。しかし、用
途によってはまだまだ不十分な点も数多く解決しなけれ
ばならない問題点が山積している。特にコンピューター
用の外部メモリーとして利用できるようにするためには
ビット誤り率で１０−１０〜ｔｏ −１２と言わｎてい
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical information detection device in a magneto-optical disk drive. In recent years, magneto-optical disks, which have been attracting attention as rewritable optical disks, have been developed to the point where they are just one step away from being put into practical use. However, there are many problems that still need to be solved, including some insufficiencies depending on the application. In particular, in order to be able to use it as an external memory for a computer, the bit error rate is said to be 10-10 to -12.
現実にはｋｅｒｒ回転角がＯ０２°〜０．５°と非常に
小さいことから８ ／ Ｎで４０ ｄＢ程度、誤り率で
１０″′番程度と言われており、コンピューター用の外
部メモリーとしてはまだまだ実用的な性能に致っていな
い。そこで、本発明は簡単な方法によってＳ ／ Ｎ
ｔ−向上させ、ビット誤り率を大幅に改善することので
きる光情報検出装置を提供するものである。In reality, the Kerr rotation angle is extremely small at 002° to 0.5°, so it is said to have an 8/N of about 40 dB and an error rate of about 10'', so it is still far behind as an external memory for computers. However, the present invention has a simple method to improve S/N.
The present invention provides an optical information detection device that can significantly improve the bit error rate.
次に、本発明を実施例に基づいて詳しく説明する。第１
図は本発明の光情報検出装置の一実施例でちる。半導体
レーザー１から出゛射した光線はコリメーターレンズ２
に入射し平行光に変換さｎる。さらに、ハーフミラ−８
に入射し、５０チが通過する。さらに、対物レンズ４に
入射し、ディスク５上にスポットを形成する。ディスク
５によって反射さｎ九反射光は再び対物レンズ４を通過
し）ハーフミラ−８に入射し、さらに５０チが７１−フ
ミラー６の方向に反射される。ハーフミラ−６に入射し
た光線は制御系とメイン信号検出系に分けら２１．る。Next, the present invention will be explained in detail based on examples. 1st
The figure shows one embodiment of the optical information detection device of the present invention. The light beam emitted from the semiconductor laser 1 passes through the collimator lens 2.
is incident on n and is converted into parallel light. In addition, half mirror 8
It is incident on , and 50chi passes through. Further, the light enters the objective lens 4 and forms a spot on the disk 5. The n9 reflected beams reflected by the disk 5 pass through the objective lens 4 again) and enter the half mirror 8, and the 50 beams are further reflected in the direction of the 71-half mirror 6. The light beam incident on the half mirror 6 is divided into a control system and a main signal detection system.21. Ru.
メイン信号検出系へ導かｎた光線は絞り７ｔ″通過し、
検光子８によってビット情報を選択しフォトディテクタ
ー９で受光する。ここで、絞り７の役割を説明するため
に、第２図にビット情報である磁区と対物レンズ４が形
成するスポットとの関係を示す。書き込み、再生、消去
の対物レンズは同一のものであるから書き込まｎた磁区
１１の幅と再生する際のスポットの直径の大きさはほぼ
同程度になる。し九がって、トラック追従する際にトラ
ックが多少ずＩｆ”Ｌｆｃ場合でもＳ ／ Ｎが非常に
低下する恐しがある。すなわち、第２図（Ｇ）のＪｕｎ
ｔｏｎ状態から第２図（ｂ）の如くトラックが少しずｎ
７’ｃだけでも反対回りのｋｅ ｒｒ回転成分が現わｎ
ることになる。ディスクによる偏心成分だけの周波数域
のノイズ成分であわば大きな問題にはならないが、光磁
気ディスクでは偏波面を検出するため、干渉効果による
ノイズが非常に大きいと言える。このノイズ領域は広範
囲にわたって存在するためＲＦ信号にも影響を及はす。The light beam guided to the main signal detection system passes through the aperture 7t'',
Bit information is selected by the analyzer 8 and received by the photodetector 9. Here, in order to explain the role of the aperture 7, FIG. 2 shows the relationship between the magnetic domain, which is bit information, and the spot formed by the objective lens 4. Since the objective lenses for writing, reproducing, and erasing are the same, the width of the written magnetic domain 11 and the diameter of the spot during reproduction are approximately the same. Therefore, when following a track, even if the track is slightly If"Lfc, there is a risk that the S/N will be very low.
As shown in Figure 2 (b), the track is gradually changing from the ton state.
Even in 7'c alone, a counter-rotating ke rr rotational component appears n
That will happen. A noise component in the frequency range that is only an eccentric component due to the disk does not pose a major problem, but since a magneto-optical disk detects the plane of polarization, it can be said that noise due to interference effects is extremely large. Since this noise region exists over a wide range, it also affects the RF signal.
そこで、検光子８の直前に、矩形の絞り７ｔ−配置する
ことによって、反対回りのＫｅｒｒ回転成分全カットす
る。すなわち、第８図に示す如く、光線束の断面１２と
絞り７の位置関係は矢印の方向がトラック方向とすると
トラックずれＫよるノイズ成分となる反対回りのｋｅｒ
ｒ回転成分をカットするように、絞り７の開口の長い向
きにトラック方向が一致するように配置さｎる。以上の
ように本発明によって、Ｓ／Ｎを大幅に改善できる。実
際上位、絶対出力が多少減少するものの、Ｓ／Ｎの向上
というメリットは実質的に価値の高いものでらり、今後
の光磁気ディスク装量全体の進歩に極めて貢献できるも
のと言える。また、組立てにおいても絞り７の位置精度
は厳しいものではないので、非常に容易であり、特雛で
きる点である。Therefore, by arranging a rectangular aperture 7t immediately in front of the analyzer 8, all of the Kerr rotation components in the opposite direction are cut out. That is, as shown in FIG. 8, the positional relationship between the cross section 12 of the beam bundle and the aperture 7 is such that when the direction of the arrow is the track direction, the ker in the opposite direction becomes a noise component due to the track deviation K.
It is arranged so that the track direction coincides with the long direction of the aperture of the diaphragm 7 so as to cut the r rotational component. As described above, according to the present invention, the S/N ratio can be significantly improved. In fact, although the absolute output is somewhat reduced in the upper end, the advantage of improved S/N is substantially valuable, and it can be said that it will greatly contribute to the future progress in the overall storage capacity of magneto-optical disks. Furthermore, since the positional accuracy of the aperture 7 is not critical during assembly, it is very easy and can be easily replicated.
第１図は本発明の光情報検出装置の概略図である。
１０．半導体レーザー、２１．コリメーターレンズ、８
０．ハーフミラ−１４０，対物レンズ５゜。ディスク
６０．ノ１−フミラー７゜。絞り ８１．検光子
９゜。フォトディテクター
第２図は、スポットと磁区の関係を示す図である。
１０、。スポット １１０．磁区
第８図は絞りと光線束の位置関係を示す図である。
７１．絞り １２゜、光線束の断面
以上
出願人 セイコー電子工業株式会社
第１図
第２図（（１）第２図（ｂ） 第３図FIG. 1 is a schematic diagram of an optical information detection device of the present invention. 10. Semiconductor laser, 21. Collimator lens, 8
0. Half mirror 140, objective lens 5°. disk
60. No. 1 - Fumira 7°. Aperture 81. Analyzer 9°. Photodetector FIG. 2 is a diagram showing the relationship between spots and magnetic domains. 10. Spot 110. FIG. 8 is a diagram showing the positional relationship between the aperture and the beam of light. 71. Aperture: 12°, cross-section of ray bundle or more Applicant: Seiko Electronics Co., Ltd. Figure 1 Figure 2 ((1) Figure 2 (b) Figure 3
Claims (4)
る第１の手段と前記平行光を集束せしめ物体面上にスポ
ットを形成する第２の手段と前記物体面上の情報をもっ
た前記物体面からの反射光を解析する第８の手段とから
なる光情報検出において、前記第８の手段の直前あるい
は直後に絞りを配置したことを特徴とする光情報検出装
置。(1) A light source, a first means for converting the light beam emitted from the light source into parallel light, a second means for converging the parallel light to form a spot on the object surface, and information on the object surface. An optical information detection device comprising an eighth means for analyzing reflected light from the object surface, wherein an aperture is disposed immediately before or after the eighth means.
−を用いたことを特徴とする特許請求の範囲第１項記載
の光情報検出装置。(2) The optical information detection device according to claim 1, wherein a polarizing beam splitter is used as the eighth means.
ことを特徴とする特許請求の範囲第１項記載の光情報検
出装置。(3). 2. The optical information detection device according to claim 1, wherein a dichroic polarizer is used as the eighth means.
許請求の範囲第１項、第２項、又は第８項記載の光情報
検出装置。(4). 9. The optical information detection device according to claim 1, 2, or 8, wherein the aperture is a rectangular aperture.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59106200A JPS60251533A (en) | 1984-05-25 | 1984-05-25 | Detecting device of optical information |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59106200A JPS60251533A (en) | 1984-05-25 | 1984-05-25 | Detecting device of optical information |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS60251533A true JPS60251533A (en) | 1985-12-12 |
Family
ID=14427521
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59106200A Pending JPS60251533A (en) | 1984-05-25 | 1984-05-25 | Detecting device of optical information |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60251533A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0241007A2 (en) * | 1986-04-10 | 1987-10-14 | Sharp Kabushiki Kaisha | Optical head |
| JPS6374132A (en) * | 1986-09-18 | 1988-04-04 | Canon Inc | Information reproducing device |
| FR2651601A1 (en) * | 1989-08-01 | 1991-03-08 | Mitsubishi Electric Corp | METHOD AND APPARATUS FOR RECORDING INFORMATION FOR MAGNETO-OPTICAL RECORDING MEDIUM |
| EP0510283A2 (en) * | 1991-04-23 | 1992-10-28 | Pioneer Electronic Corporation | Optical pickup device |
| JPH0950644A (en) * | 1995-05-31 | 1997-02-18 | Nec Corp | Optical head device |
| EP0713212A3 (en) * | 1994-11-17 | 1997-03-05 | Canon Kk | Optical information recording and reproducing apparatus |
-
1984
- 1984-05-25 JP JP59106200A patent/JPS60251533A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0241007A2 (en) * | 1986-04-10 | 1987-10-14 | Sharp Kabushiki Kaisha | Optical head |
| JPS6374132A (en) * | 1986-09-18 | 1988-04-04 | Canon Inc | Information reproducing device |
| FR2651601A1 (en) * | 1989-08-01 | 1991-03-08 | Mitsubishi Electric Corp | METHOD AND APPARATUS FOR RECORDING INFORMATION FOR MAGNETO-OPTICAL RECORDING MEDIUM |
| US5309415A (en) * | 1989-08-01 | 1994-05-03 | Mitsubishi Denki Kabushiki Kaisha | Information recording method for overwriting a magneto-optic recording medium with two intensities of light beams |
| EP0510283A2 (en) * | 1991-04-23 | 1992-10-28 | Pioneer Electronic Corporation | Optical pickup device |
| EP0713212A3 (en) * | 1994-11-17 | 1997-03-05 | Canon Kk | Optical information recording and reproducing apparatus |
| JPH0950644A (en) * | 1995-05-31 | 1997-02-18 | Nec Corp | Optical head device |
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