JPS60121558A - Optical magnetic reproducing device - Google Patents
Optical magnetic reproducing deviceInfo
- Publication number
- JPS60121558A JPS60121558A JP22866883A JP22866883A JPS60121558A JP S60121558 A JPS60121558 A JP S60121558A JP 22866883 A JP22866883 A JP 22866883A JP 22866883 A JP22866883 A JP 22866883A JP S60121558 A JPS60121558 A JP S60121558A
- Authority
- JP
- Japan
- Prior art keywords
- beam splitter
- light
- polarization
- recording medium
- face
- 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
- 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
Abstract
Description
【発明の詳細な説明】
<fL業上の利用分野)
この発明は、ビームスプリッタ自体に偏光特性をf]与
覆ることにより、再生感度を向上させた光磁気再生装置
にr!Aする。[Detailed Description of the Invention] <Field of Application in the fL Industry) This invention provides a magneto-optical reproducing device with improved reproduction sensitivity by imparting polarization characteristics to the beam splitter itself. A.
(従来技術とその問題点) 第1図に従来の光磁気再生装置の構成を示す。(Prior art and its problems) FIG. 1 shows the configuration of a conventional magneto-optical reproducing device.
同図に示す如く、従来の光磁気再生装置にあって(よ、
レーザダイオード1から発せられた光をコリメータレン
ズ2を介して偏光子3へ導き、ここで直線偏光の精度を
上昇させた後、更に偏光子3の透過光を透過1反射がほ
ぼ等しいハーフミラ−で構成されたビームスプリッタべ
によって、記録媒体5側へど90°屈折させた後、これ
を収束レンズ6を介して記録媒体5の記録面5aへと導
(。As shown in the figure, in the conventional magneto-optical reproducing device (
The light emitted from the laser diode 1 is guided through the collimator lens 2 to the polarizer 3, where the accuracy of linear polarization is increased, and then the light transmitted through the polarizer 3 is guided through a half mirror with approximately equal transmission and reflection. After being refracted by 90° toward the recording medium 5 by the constructed beam splitter, it is guided to the recording surface 5a of the recording medium 5 via the converging lens 6.
次いで、記録面で反射された反射光は、再び収束レンズ
6で収束された後、ビームスプリッタ4を透過して取り
出される。Next, the reflected light reflected by the recording surface is again converged by the converging lens 6, and then transmitted through the beam splitter 4 and extracted.
ここで、周知の如く光磁気再生方式にあっては、この透
過光の偏光成分に基づいて記録情報を再生ずることがで
きる。具体的には、前記と同様な構成のビームスプリッ
タ7によって、透過光線を2系統に分岐させた後、その
一方は検光子8を経由して受光素子9へと導かれ、他方
は検光子10を経由して受光素子11へと導かれる。Here, as is well known, in the magneto-optical reproducing system, recorded information can be reproduced based on the polarization component of this transmitted light. Specifically, after the transmitted light beam is split into two systems by the beam splitter 7 having the same configuration as described above, one of the beams is guided to the light receiving element 9 via the analyzer 8, and the other is guided to the light receiving element 9 via the analyzer 10. The light is guided to the light receiving element 11 via the.
そして、受光素子9と11との出力を差動増幅器12で
演算づ−ることによって、光源の起動変化等にかかわら
ず安定したレベルの出力情報を得ることができるのであ
る。By calculating the outputs of the light receiving elements 9 and 11 using the differential amplifier 12, it is possible to obtain output information at a stable level regardless of changes in the start-up of the light source.
しかしながら、このような従来の光磁気再生装置にあっ
ては、一般にレーザダイオード1の偏光度が不充分であ
るため、K err回転の検出感度を充分高めるために
はビームスプリッタ4の手前に偏光子3を介在させ、こ
れにより直線偏光の精度を上昇さμ゛る必要がある。However, in such a conventional magneto-optical reproducing device, the degree of polarization of the laser diode 1 is generally insufficient, so in order to sufficiently increase the detection sensitivity of Kerr rotation, a polarizer is installed before the beam splitter 4. 3 to increase the accuracy of linearly polarized light.
また、ビームスプリッタ4としては透過1反射がほぼ等
しいハーフミラ−が使用されているため、記録媒体1で
反射された反射光はビームスプリッタ4を透過りる間に
大きく減衰されてしまい、殊にKerr効果による偏光
面の回転は、入射光のそれに対して0.3〜1°程度し
かないため、情報11■生感度が低い等の問題点をイi
していた。In addition, since a half mirror is used as the beam splitter 4, in which transmission and reflection are approximately equal, the reflected light reflected by the recording medium 1 is greatly attenuated while passing through the beam splitter 4. Since the rotation of the polarization plane due to the effect is only about 0.3 to 1° relative to that of the incident light, information 11
Was.
(発明の目的)
この発明の目的は、この種の光磁気再生装置にJ5いて
、ビームスプリッタの手前に直線偏光の精度を14させ
るための偏光子を介在することを不要とづるどともに、
ビームスプリッタを透過する間に再生情報に相当する偏
光成分が大きく減衰することを防止し、これにより再生
感麿を向上させることにある。(Object of the Invention) The object of the present invention is to eliminate the need for a polarizer in front of the beam splitter to increase the accuracy of linear polarization by J5 in this type of magneto-optical reproducing device, and to
The objective is to prevent polarized light components corresponding to reproduced information from being greatly attenuated while passing through a beam splitter, thereby improving reproduction sensitivity.
(発明の構成)
この発明は、上記の目的を達成するために、レーザ光源
からの光をビームスプリッタで反射させた後光磁気記録
媒体上に照射し、該記録媒体で反射された光を前記ビー
ムスプリッタに透過させ、該透過光の偏光成分に基づい
て記録情報を再生ずる光磁気再生装置において、前記ビ
ームスプリッタ自体に偏光特性を付与したことを特徴と
づるものである。(Structure of the Invention) In order to achieve the above object, the present invention reflects light from a laser light source by a beam splitter and then irradiates it onto a magneto-optical recording medium, and the light reflected by the recording medium is directed to the magneto-optical recording medium. A magneto-optical reproducing device that transmits light through a beam splitter and reproduces recorded information based on the polarization component of the transmitted light is characterized in that the beam splitter itself has polarization characteristics.
(実施例の説明)
第2図は、この発明に係わる光磁気再生装置の構成を示
す模式図である。なお同図において、前記第1図と同一
構成部分については同符号をイリシて説明は省略する。(Description of Embodiments) FIG. 2 is a schematic diagram showing the configuration of a magneto-optical reproducing apparatus according to the present invention. In this figure, the same reference numerals are used for the same components as in FIG. 1, and the explanation thereof will be omitted.
この実施例の特徴は、レーザダイオード1から発せられ
、コリメータレンズ2を経由した光を、ただちにビーム
スプリッタ13へと導いたことにある。The feature of this embodiment is that the light emitted from the laser diode 1 and passed through the collimator lens 2 is immediately guided to the beam splitter 13.
すなわち、このビームスプリッタ13は次のような特性
を有する。That is, this beam splitter 13 has the following characteristics.
例えば、紙面垂直方向に振動面を持つ光(以下、これを
ビームスプリッタに対してS波と呼ぶ)と、紙面内に振
動面を持つ光(以下、これをP波と呼ぶ)に対して、そ
れぞれ
反射率: R8を0.3〜0.8
RpをRsより小
透過率; ]−8を0.2〜0.7
Tpを0.5〜1.0 (Tp>Ts )ただし、Rs
→−Ts≦1゜
FLp+Tll≦1とする。For example, for light with a vibration plane perpendicular to the plane of the paper (hereinafter referred to as an S wave for a beam splitter) and light with a vibration plane within the plane of the paper (hereinafter referred to as a P wave), Reflectance: R8: 0.3-0.8 Rp: transmittance smaller than Rs; ]-8: 0.2-0.7 Tp: 0.5-1.0 (Tp>Ts) However, Rs
→−Ts≦1°FLp+Tll≦1.
そして、レーザダイオード1からのレーザ光線の偏光面
は、S波に合致させられている。The plane of polarization of the laser beam from the laser diode 1 is made to match the S wave.
このような構成によれば、ビームスプリッタ13に入射
した後、該ビームスプリッタで反射されて記録媒体5側
へと出射されるレーザ光の偏光度は、R8/R11lイ
Bに上昇する。According to such a configuration, the degree of polarization of the laser beam that enters the beam splitter 13, is reflected by the beam splitter, and is emitted toward the recording medium 5 side increases to R8/R11lB.
また、記録媒体5で反射された後、ビームスプリッタ1
3を透過して受光器側へ至る透過光線については、K
err回転角をTIE/Ts倍に上昇さ仕ることができ
、従って僅かなK err回転角を持った反射光を弱め
ることなく受光器側へと送り出すことができるのである
。Also, after being reflected by the recording medium 5, the beam splitter 1
Regarding the transmitted light ray that passes through 3 and reaches the receiver side, K
The err rotation angle can be increased by a factor of TIE/Ts, and therefore the reflected light having a small kerr rotation angle can be sent to the light receiver without weakening.
なお、°[pはできるだけ大きく、かっRpはできるだ
【プ小さいことが好ましく、更にRsまたは丁Sは0.
5前後が好ましい。In addition, °[p is as large as possible, Rp is preferably as small as possible, and Rs or S is preferably 0.
Around 5 is preferable.
更に、S波、P波の関係は上記と全く逆にしても良いこ
とは勿論である。Furthermore, it goes without saying that the relationship between S waves and P waves may be completely reversed.
次に、本発明者らが行なった具体的な実験例を示す。Next, specific experimental examples conducted by the present inventors will be shown.
TS=41%、T9=90%
R8=53%、Rp =3%
のビームスプリッタ13を用いて、みhl 4プの1(
err回転角を約2倍に上昇させることができ、S/N
の良好な信号を得ることができた。Using the beam splitter 13 with TS = 41%, T9 = 90%, R8 = 53%, Rp = 3%,
It is possible to increase the err rotation angle by approximately twice, and the S/N
I was able to get a good signal.
また、レーザ光源の偏光度はP波とS波の反射率の相違
で光磁気記録材料へ入IJJする際に高められるので、
従来のように事前に偏光子を設ける必要がなくなり、す
なわちビームスプリッタ自体に偏光子の役目をも兼ねさ
せることが可vしとなるのCある。In addition, the degree of polarization of the laser light source is increased when it enters the magneto-optical recording material due to the difference in the reflectance of P waves and S waves.
There is no need to provide a polarizer in advance as in the prior art, and in other words, it becomes possible for the beam splitter itself to also serve as a polarizer.
(発明の効果)
以上の実施例の説明でも明らかなように、この発明に係
わる光磁気再生装置は、レーザ光源からの光をビームス
プリッタで反射させた後、光磁気記録媒体上に照射し、
該記録媒体で反射された光を前記ビームスプリッタに透
過させ、該透過光の偏光成分に基づいて記録情報を再生
する光磁気再生装置において、前記ビームスプリッタ自
体に偏光特性を付与したものであるから、レーデ光源か
らの光をビームスプリッタで反射さ迂て記録媒体上に導
くに際して、ビームスブリット作用に加え、シー11光
の偏光度を上昇させることができ、このため従来装置で
必要だった偏光子を不要とすることができる。(Effects of the Invention) As is clear from the description of the embodiments above, the magneto-optical reproducing apparatus according to the present invention reflects light from a laser light source by a beam splitter, and then irradiates the light onto a magneto-optical recording medium.
In a magneto-optical reproducing device that transmits light reflected by the recording medium to the beam splitter and reproduces recorded information based on the polarization component of the transmitted light, the beam splitter itself is provided with polarization characteristics. When the light from the Rede light source is reflected by the beam splitter and guided onto the recording medium, in addition to the beam splitting effect, it is possible to increase the degree of polarization of the SEA light, which eliminates the need for a polarizer, which was required in conventional devices. can be made unnecessary.
更に、記録媒体で反射されビームスプリッタを透過して
受光器側へ至る構成についても、ビームスプリッタを透
過する間に反射光のK err回転角を増幅、!けるこ
とができ、このため再生感度を向」さUることができる
。Furthermore, regarding the configuration in which the reflected light is reflected by the recording medium and transmitted through the beam splitter to reach the receiver, the Kerr rotation angle of the reflected light is amplified while passing through the beam splitter. Therefore, the reproduction sensitivity can be improved.
第1図は従来装置の構成を示す模式図、第2図は本発明
装置の構成を示す模式図である。
1・・・レーザダイオード
5・・・記録媒体
13・・・ビームスプリッタ
特許出願人
日本楽器製造株式会社
第1図
第2図FIG. 1 is a schematic diagram showing the configuration of a conventional device, and FIG. 2 is a schematic diagram showing the configuration of the device of the present invention. 1... Laser diode 5... Recording medium 13... Beam splitter Patent applicant Nippon Musical Instruments Manufacturing Co., Ltd. Figure 1 Figure 2
Claims (1)
後、光磁気記録媒体上に照射し、該記録媒体で反射され
た光を前記ビームスプリッタに透過させ、該透過光の偏
光成分に基づいて記録情報を再生ずる光磁気再生装置に
おいて; 前記ビームスプリッタ自体に、偏光特性を(=l与して
なることを特徴とする光磁気再生装置。[Claims] After light from a laser beam source is reflected by a beam splitter, it is irradiated onto a magneto-optical recording medium, the light reflected by the recording medium is transmitted to the beam splitter, and the transmitted light is In a magneto-optical reproducing device for reproducing recorded information based on polarization components: A magneto-optical reproducing device characterized in that the beam splitter itself is given a polarization characteristic (=l).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22866883A JPS60121558A (en) | 1983-12-03 | 1983-12-03 | Optical magnetic reproducing device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22866883A JPS60121558A (en) | 1983-12-03 | 1983-12-03 | Optical magnetic reproducing device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS60121558A true JPS60121558A (en) | 1985-06-29 |
Family
ID=16879936
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP22866883A Pending JPS60121558A (en) | 1983-12-03 | 1983-12-03 | Optical magnetic reproducing device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS60121558A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6370950A (en) * | 1986-09-12 | 1988-03-31 | Canon Inc | Magneto-optical signal reproducer |
-
1983
- 1983-12-03 JP JP22866883A patent/JPS60121558A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6370950A (en) * | 1986-09-12 | 1988-03-31 | Canon Inc | Magneto-optical signal reproducer |
JPH07101523B2 (en) * | 1986-09-12 | 1995-11-01 | キヤノン株式会社 | Magneto-optical signal reproducing device |
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