CN1032599A - 光学扫描器 - Google Patents

光学扫描器 Download PDF

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CN1032599A
CN1032599A CN88106783A CN88106783A CN1032599A CN 1032599 A CN1032599 A CN 1032599A CN 88106783 A CN88106783 A CN 88106783A CN 88106783 A CN88106783 A CN 88106783A CN 1032599 A CN1032599 A CN 1032599A
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photodetector
photovoltage
light beam
magneto
grade
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CN1012115B (zh
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亚萨基·莫里莫托
弗里德海姆·佐克
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Sommersen Brant GmbH
Deutsche Thomson Brandt GmbH
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    • 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
    • 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
    • G11B11/10502—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 characterised by the transducing operation to be executed
    • G11B11/10515—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
    • 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
    • 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
    • G11B11/1055—Disposition or mounting of transducers relative to record carriers
    • G11B11/10576—Disposition or mounting of transducers relative to record carriers with provision for moving the transducers for maintaining alignment or spacing relative to the carrier

Abstract

用于扫描-磁光记录载体的光学扫描器。为既 减小数据信号S中的噪音又不需精心调整第二光检 测器，将高于+1.级和低于-1.级的光束也从磁光记录 载体反射到第二光检测器。为产生数据信号，至少从 第二光检测器的光电压中除去由+1.级和-1.级光束 产生的光电压。由此，可选择较大的第二光检测器， 并且不需要精心调整。

Description

本发明涉及一个依据三束光方法扫描-磁光记录载体的光学扫描器，该装置具有一光学衍射部件，在此部件作用下，其偏振面向某一方向偏转的主光束从磁光记录载体被反射到第一光检测器，其偏振面向另一方向偏转的主光束从磁光记录载体被反射到第二光检测器，并借此部件由第一和第二光检测器的光电压之差而产生数据信号。
在“电子元件及应用”（Electronic    components    &    applications）的1984年第6卷第4期（Vol.6，No.4，1984）上第209-215页已描述了一种用于激光唱机的光学扫描器（所谓光拾音器）的构造和功能。
在1986年6月20日无线电杂志（Funkschau）第13期第37-41页上一篇叫做“磁光试验在继续进行”的文章中，描述了如何利用克耳效应将数据写入磁光盘并从其中读出。
图1示出一光扫描器，它根据三光束方法可读出磁光盘6。从一光源1（大部分是激光）发出的光束通过一透镜，一衍射光栅3、一分光棱镜4和另一个透镜5聚焦到磁光盘6上。由于衍射光栅3的作用，光束被分为光主束及+1.，-1.，+2.，-2.级等等光束。主光束用于读出数据，而+1.级和-1.级光束用来产生声迹误差信号TE＝ES-FS。被磁光盘6反射的光束，即主光束及+1.和-1.级光束，通过透镜5回到分光棱镜4，其中主光束及+1.和-1.级光束的偏振平面，按磁光盘6的磁化方向在焦点向右或向左偏转，分光棱镜使光线以合适的角度通过λ/2片7和透镜8而引到偏振光束分配器9。向某一方向（例如向右）偏转的主光束通过透镜10到达一个由四个扇形A、B、C、D组成的光检测器11，而向左偏转的主光束引向光检测器12。其偏振面向右偏转的+1.级光束，通过透镜11落到光检测器F上，而其偏振面同样向右偏转的-1.级光束通过透镜11落到光检测器E上。向另一方向（在所给出的例子中是向左）偏转的主光束及同样向左偏转的+1.和-1.级光束落在光检测器12上，该检测器的光电压GS送到差动放大器13的减法输入端。扇形A、B、C、D的输出电压AS、BS、CS、DS送到差动放大器13的加法输入端，在差动放大器的输出端得到数据信号S＝AS+BS+CS+DS-PS。光检测器E的光电压ES送到差动放大器14的加法输入端，而光检测器F的光电压FS送到差动放大器14的减法输入端。因此，在差动放大器14的输出端可得到声迹误差信号TE＝ES-FS。
由于只有主光束落在由扇形A、B、C、D组成的光检测器11上，而落在光检测器12上的，除主光束之外，还有高于或低于O.级的光束，因此增加了数据信号S的噪声。为消除这个由衍射产物（较高或较低级光束）引起的不希望有的噪声，要精心调整光检测器12，使得只有主光束击中它。这种范围大约为100μm的调整是很困难的，不仅要求非常感觉敏锐，还要花费大量时间。
因此，本发明的任务是，设计一种如权利要求1前序部分所述的光扫描器，它能避免由高于或低于O.级的衍射产物所引起的数据信号中噪声的增强，而不需对第二个光检测器进行精心调整。
本发明根据以下方法完成上述任务：高于+1.级和低于-1.级的光束也从磁光记录载体反射到第二光检测器上，为产生数据信号，至少要从第二光检测器的光电压PS中除去+1.级和-1.级光束产生的光电压。
现在根据图2所示的实施例来解释本发明。
如图1一样，发出的光束通过一透镜2、一衍射光栅3、一分光棱镜4和另一个透镜5聚焦到磁光盘6上。由于衍射光栅3的作用，光束被分为主光束及+1.，-1.，+2.，-2.级光束等。主光束用于读出数据，而+1.级和-1.级光束用来产生声迹误差信号TE＝ES-FS。被磁光盘6反射的光束，即主光束和+1.，-1.级光束，通过透镜5回到分光棱镜4，其中主光束及+1.和-1.级光束的偏振平面按磁光盘6的磁光方向在主光束的焦点向右或向左偏转，分光棱镜使光束以合适的角度通过λ/2片7和透镜8引到偏振光束分配器9。向某一方向（例如向右）偏转的主光束通过透镜10到达由四个扇形A、B、C、D组成的光检测器11，而向左偏转的主光束被引到光检测器12。其偏振面向右偏转的+1.级光束通过透镜11落到光检测器F上，而其偏振面也向右偏转的-1.级光束通过透镜11落到光检测器E上。向另一方向（在所给出的例子中是向左）偏转的主光束及同样向左偏转的+1.和-1.级光束落在光检测器12上。光检测器E的光电压ES送到差动放大器13的第一加法输入端和差动放大器14的加法输入端，在差动放大器13的输出端得到数据信号S。光检测器F的光电压FS送到差动放大器13的第二加法输入端和差动放大器14的减法输入端，在差动放大器14的输出端得到声迹误差信号TE＝ES-FS。光检测器11的每个扇形部分A、B、C、D的光电压AS、BS、CS、DS送到差动放大器13的各个减法输入端。在光检测器F的旁边放置一光检测器G，使高于+1.级的光束落在其上。在光检测器E的旁边放置一光检测器H，使低于-1.级的光束落在其上。光检测器G、H和12的光电压GS、HS、PS送到差动放大器13的一个加法输入端。于是，在差动放大器13形成数据信号S＝ES+FS+GS+HS+PS-（AS+BS+CS+DS），这个信号只是表示两个0.级光束（向右和向左偏转的主光束）的差分信号，因为由衍射产生的高于或低于0.级的光电压ES、FS、GS和HS都被从光电压PS所有光电压之和中除去。因为光电压ES、FS、GS和HS与光检测器12中由衍射产生的高于或低于0.级的光电压相位偏移180°，所以它们互相之间以加法形式连结。
由于在差动放大器13中，从光电压PS（其偏振面向某一方向偏转的衍射产物和主光束的光电压之和）中除去了衍射产物引起的光电压，所以可选择一个较大的光检测器用作光检测器12，它不用像本文开始时所描述的那样需要精心调整，而只需粗略调整就可以了。
为简化起见，在图2所示的实施例中可省略光检测器G和H。这样，虽然从光检测器12的光电压PS中只除去了+1.和-1.级衍射产物引起的光电压，但已相当大地减少了数据信号S中的噪声。

Claims (3)

1、依据三光束方法扫描-磁光记录载体的光学扫描器，具有一光学衍射部件，在此部件作用下，其偏振面向某一方向偏转的主光束从磁光记录载体(6)被反射到第一光检测器(11)，其偏振面向另一方向偏转的主光束从磁光记录载体(6)被反射到第二光检测器(12)，并借此部件由第一和第二光检测器(11，12)光电压之差而产生数据信号，其特征在于，高于+1.级和低于-1.级的光束也反射到第二光检测器(12)，为产生数据信号(S)，至少要从第二光检测器(12)的光电压PS中除去+1.级和-1.级光束产生的光电压。
2、如权利要求1所述的光学扫描器，其特征在于，设置第三光检测器（E），+1.级光束从磁光记录载体（6）反射到该检测器;设置第四光检测器（F），-1.级光束从磁光记录载体（6）反射到该检测器;由第三和第四光检测器（E，F）的光电压ES和FS之差产生声迹误差信号TE＝ES-FS;从第二光检测器（12）的光电压PS中除去光电压ES和FS。
3、如权利要求2所述的光学扫描器，其特征在于，设置第五光检测器（G），高于+1.级的光束从磁光记录载体（6）反射到该检测器;设置第六光检测器（H），低于-1.级的光束从磁光记录载体反射到该检测器;从第二光检测器（12）的光电压中除去第五和第六光检测器（G，H）的光电压GS和HS。
CN88106783A 1987-09-30 1988-09-21 光学扫描器 Expired CN1012115B (zh)

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DEP3732944.8 1987-09-30
DE19873732944 DE3732944A1 (de) 1987-09-30 1987-09-30 Optische abtastvorrichtung

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CN1012115B CN1012115B (zh) 1991-03-20

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JP (1) JP2907842B2 (zh)
KR (1) KR960016890B1 (zh)
CN (1) CN1012115B (zh)
AT (1) ATE86776T1 (zh)
DE (2) DE3732944A1 (zh)
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JPS5958637A (ja) * 1982-09-28 1984-04-04 Sony Corp 光学式再生装置
US4691308A (en) * 1984-04-19 1987-09-01 Nippon Kogaku K. K. Apparatus for reproducing information from magnetooptical recording medium

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1053514C (zh) * 1991-06-04 2000-06-14 国际商业机器公司 多数据表面数据存贮系统和方法

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HUT61120A (en) 1992-11-30
DE3732944A1 (de) 1989-04-13
DK547988A (da) 1989-03-31
JP2907842B2 (ja) 1999-06-21
EP0309675B1 (de) 1993-03-10
DK547988D0 (da) 1988-09-30
US4959821A (en) 1990-09-25
KR890005686A (ko) 1989-05-16
JPH01106348A (ja) 1989-04-24
DE3879064D1 (de) 1993-04-15
EP0309675A1 (de) 1989-04-05
KR960016890B1 (ko) 1996-12-26
ES2039517T3 (es) 1993-10-01
CN1012115B (zh) 1991-03-20
ATE86776T1 (de) 1993-03-15

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