JPH0552574B2 - - Google Patents
Info
- Publication number
- JPH0552574B2 JPH0552574B2 JP24200683A JP24200683A JPH0552574B2 JP H0552574 B2 JPH0552574 B2 JP H0552574B2 JP 24200683 A JP24200683 A JP 24200683A JP 24200683 A JP24200683 A JP 24200683A JP H0552574 B2 JPH0552574 B2 JP H0552574B2
- Authority
- JP
- Japan
- Prior art keywords
- recording medium
- light
- detection system
- optical
- storage device
- 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
- 230000003287 optical effect Effects 0.000 claims description 33
- 238000001514 detection method Methods 0.000 claims description 17
- 230000000694 effects Effects 0.000 claims description 11
- 230000010287 polarization Effects 0.000 claims description 8
- 230000003321 amplification Effects 0.000 claims description 2
- 238000006243 chemical reaction Methods 0.000 claims description 2
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 2
- 238000000034 method Methods 0.000 description 13
- 238000010586 diagram Methods 0.000 description 4
- 230000005415 magnetization Effects 0.000 description 4
- 230000010365 information processing Effects 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 2
- 230000005374 Kerr effect Effects 0.000 description 1
- 239000000020 Nitrocellulose Substances 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 235000009754 Vitis X bourquina Nutrition 0.000 description 1
- 235000012333 Vitis X labruscana Nutrition 0.000 description 1
- 240000006365 Vitis vinifera Species 0.000 description 1
- 235000014787 Vitis vinifera Nutrition 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000005291 magnetic effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229920001220 nitrocellulos Polymers 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 230000010076 replication Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
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
-
- 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
- G11B11/10582—Record carriers characterised by the selection of the material or by the structure or form
-
- 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
- G11B11/10582—Record carriers characterised by the selection of the material or by the structure or form
- G11B11/10584—Record carriers characterised by the selection of the material or by the structure or form characterised by the form, e.g. comprising mechanical protection elements
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B13/00—Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for
- G11B13/04—Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for magnetically or by magnetisation and optically or by radiation, for changing or sensing optical properties
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B13/00—Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for
- G11B13/04—Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for magnetically or by magnetisation and optically or by radiation, for changing or sensing optical properties
- G11B13/045—Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for magnetically or by magnetisation and optically or by radiation, for changing or sensing optical properties combined recording by magnetic and optic means
-
- 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
- G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
-
- 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
- G11B7/007—Arrangement of the information on the record carrier, e.g. form of tracks, actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track
-
- 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
- G11B7/007—Arrangement of the information on the record carrier, e.g. form of tracks, actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track
- G11B7/00745—Sectoring or header formats within a track
-
- 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
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/0938—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following servo format, e.g. guide tracks, pilot signals
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は、光磁気デイスク装置に係り、特に、
デイスクのトラツク、セクター単位に情報の処理
を行なうことの出来る光磁気情報処理方式に関す
る。DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magneto-optical disk device, and in particular,
This invention relates to a magneto-optical information processing system that can process information on a disk track or sector basis.
書き換え可能な光デイスクとして、光磁気デイ
スクの実用化研究が盛んに行なわれている。光磁
気デイスクには、情報トラツクの溝を凹凸の形で
予め作り付けておく方法が多く用いられている。
しかしトラツク、あるいは1トラツク中のある特
定のセクターをアクセスして、トラツクあるいは
セクター単位で情報の記録、再生および消去を行
なうためには、トラツク、セクター番号を含む、
情報の円滑な処理に最低限必要なヘツダー情報を
デイスクに記録しておき、それを光ヘツドで再生
する必要がある。
Research into the practical use of magneto-optical disks as rewritable optical disks has been actively conducted. For magneto-optical disks, a method is often used in which the grooves of the information track are formed in advance in the form of unevenness.
However, in order to access a track or a specific sector within one track and record, reproduce, and erase information on a track or sector basis, it is necessary to
It is necessary to record the minimum header information necessary for smooth information processing on a disk, and to reproduce it using an optical head.
書き換えの出来ない光デイスクにおいては、予
めグルーブ(溝)が記録トラツクに対応して、情
報の記録再生に使用するレーザ光の1/8波長の深
さでデイスクに作り付けられている。この溝をト
ラツク追従の指標としながらトラツキング動作及
びオートフオーカス動作を行ない情報の記録再生
を実行している。 In non-rewritable optical discs, grooves are formed in advance on the disc to correspond to recording tracks and have a depth of 1/8 wavelength of the laser beam used for recording and reproducing information. Tracking operations and autofocus operations are performed using this groove as an index for tracking, thereby recording and reproducing information.
又ヘツダー情報は、1/4波長の深さでピツトを
形成することにより予め記録される。ユーザーが
記録したいデータは、グループ上に孔をあけるこ
とにより、記録されることになる。 Further, header information is recorded in advance by forming pits at a depth of 1/4 wavelength. The data that the user wants to record will be recorded by punching a hole on the group.
しかし、カー効果、フアラデー効果に代表され
る光磁気効果を利用して情報の再生を行ない、光
熱磁気効果による情報の記録、消去を行なう光磁
気デイスク及び光磁気デイスク装置に関しては上
記の様なセクター単位に情報の管理を行なうため
の方法が確立されていない。 However, regarding magneto-optical disks and magneto-optical disk devices that reproduce information using the magneto-optical effect represented by the Kerr effect and the Faraday effect, and record and erase information using the photothermal magnetic effect, the sectors described above are There is no established method for managing information on a per-unit basis.
例えば、ヘツダー情報を磁化の向きで予め記録
することが考えられる。しかし、その方法では、
デイスク一枚一枚に、いちいちレーザ光照射して
記録しなければならないので大量生産向きではな
い。しかも、誤つてヘツダー情報を消してしまう
恐れもある。さらには従来型の書き換えの出来な
い光デイスクやデイジタルオーデイオデイスク
(DAD)、ヒデオデイスク(VD)等の再生専用光
デイスクと光磁気デイスクとを同一装置では処理
出来ない。 For example, it is possible to record header information in advance in the direction of magnetization. However, with that method,
Since each disc must be irradiated with laser light and recorded, it is not suitable for mass production. Furthermore, there is a risk of accidentally erasing the header information. Furthermore, it is not possible to process read-only optical disks such as conventional non-rewritable optical disks, digital audio disks (DAD), video disks (VD), and magneto-optical disks using the same device.
この様に、従来提案されている光磁気デイスク
及び装置に関してはセクター単位での情報管理が
できない、さらには従来型の書き換えの出来ない
光デイスクとの兼用使用が出来ない等といつた欠
点があつた。 As described above, conventionally proposed magneto-optical disks and devices have drawbacks such as not being able to manage information on a sector-by-sector basis, and furthermore, not being able to be used in combination with conventional non-rewritable optical disks. Ta.
本発明の目的は、光磁気デイスクにおいて、セ
クター単位で情報の取扱いが出来る方式を提供す
ることにある。本発明の他の目的は、従来型の書
き換えの出来ない光デイスクや、再生等用のデジ
タルオーデイオデイスク、ビデオデイスクをも取
扱い可能な、光磁気デイスク情報処理方式を提供
することにある。
SUMMARY OF THE INVENTION An object of the present invention is to provide a method for handling information on a sector-by-sector basis in a magneto-optical disk. Another object of the present invention is to provide a magneto-optical disk information processing system that can handle conventional non-rewritable optical disks, digital audio disks for reproduction, etc., and video disks.
本発明では、光磁気デイスクのヘツダー部は、
凹凸型とする。ヘツダー部の再生は、反射光量の
変化を検出することによる。データ部は磁化の向
きを光磁気効果を利用して再生するものとする。
一方装置側は、ヘツダー部分の読み取り専用の光
検出器とデータ部分の読み取り専用の光検出器と
2つの光検出器を別々に設けることにより上記目
的を達成しようとするものである。
In the present invention, the header portion of the magneto-optical disk is
It has an uneven shape. Reproduction of the header section is performed by detecting changes in the amount of reflected light. The data section shall reproduce the direction of magnetization using the magneto-optical effect.
On the other hand, the apparatus side attempts to achieve the above object by separately providing two photodetectors: a photodetector for reading only the header portion and a photodetector only for reading the data portion.
以下実施例とともに本発明を説明する。 The present invention will be explained below with reference to Examples.
第1図は本発明による光磁気デイスクのデイス
ク形態を示す図である。図において1は光磁気デ
イスクであり、11は該デイスク上に設けられた
トラツクを示す。111は該トラツクの一部分す
なわち、セクターを示したものである。第2図に
その半径方向の断面構造を示す。 FIG. 1 is a diagram showing the disk form of a magneto-optical disk according to the present invention. In the figure, 1 is a magneto-optical disk, and 11 is a track provided on the disk. Reference numeral 111 indicates a portion of the track, that is, a sector. FIG. 2 shows its radial cross-sectional structure.
第2図において2は予め設けられた案内溝(グ
レープ)であり、該案内溝の深さは記録再生に用
いるレーザ光波長の1/8に設定されている。この
案内溝を光学的に検知することによりトラツキン
グを行なう方法は公知である。トラツク番号、セ
クタ番号を含むヘツダー情報は、第3図に示す様
に、該案内溝2に対してさらに1/8波長分深くし、
全体で1/4波長の深さを持つたピツト3として設
けられる。このようにトラツク溝とヘツダー情報
をもつた凹凸ピツトとは一度、デイスク原盤に光
記録しておけば、公知のレプリケーシヨン法によ
り、大量にレプリカデイスクを生産することがで
きる。 In FIG. 2, reference numeral 2 denotes a guide groove (grape) provided in advance, and the depth of the guide groove is set to 1/8 of the wavelength of the laser beam used for recording and reproduction. A method of tracking by optically detecting this guide groove is known. The header information including the track number and sector number is further deepened by 1/8 wavelength with respect to the guide groove 2, as shown in FIG.
It is provided as a pit 3 with a total depth of 1/4 wavelength. Once the track grooves and the uneven pits with header information are optically recorded on the disk master, replica disks can be produced in large quantities by the known replication method.
第4図に、具体的な光磁気デイスク構造のより
詳細な断面図を示す。41は光磁気効果を有する
Tb−Feを主組成として持つ膜厚約1000Åの材質
であり、その上下をそれぞれ約1400Åの厚さの
SiO242で、はさみ込んでいる。基板45は約
1mm厚のガラスを用い、その上に紫外線硬化樹脂
(UV)44,ニトロセルロース(CN)43を介
し、前述の光磁気効果膜41,42が設けられた
構造になつている。 FIG. 4 shows a more detailed sectional view of a specific magneto-optical disk structure. 41 has magneto-optical effect
It is a material with a thickness of about 1000 Å with Tb-Fe as the main composition, and the upper and lower layers are each about 1400 Å thick.
It is sandwiched with SiO 2 42. The substrate 45 is made of glass with a thickness of about 1 mm, and the above-mentioned magneto-optical effect films 41 and 42 are provided thereon with an ultraviolet curing resin (UV) 44 and a nitrocellulose (CN) 43 interposed therebetween.
第5図は該光磁気デイスクに対してデータの記
録再生消去を行なうための光ヘツドに関する基本
構成を示すブロツク図である。半導体レーザ4か
ら射出されたレーザ光はレンズ5により平行光に
された後偏光プリズム6、ガルバノミラー7、オ
ートフオーカス(AF)用ボイスコイル8内のオ
ブジエクトレンズを通過しデイスク1の案内溝2
の設けられた面に照射される。デイスク1からの
反射光はオブジエクトレンズ、ガルバノミラー7
を通り偏光プリズム6で反射された後、さらにプ
リズム9により分離され一方はヘツダー部読み取
り用光検出器10に導かれ、他方は検光子12に
より偏光角の変化を光強度の変化に変換された後
データ部読み取り用光検出器13に導かれる。 FIG. 5 is a block diagram showing the basic structure of an optical head for recording, reproducing, and erasing data on the magneto-optical disk. The laser beam emitted from the semiconductor laser 4 is made into parallel light by the lens 5, and then passes through the polarizing prism 6, the galvanometer mirror 7, and the object lens in the voice coil 8 for autofocus (AF), and then passes through the guide groove 2 of the disk 1.
is irradiated onto the surface provided with. The reflected light from disk 1 is passed through object lens and galvano mirror 7.
After passing through and being reflected by a polarizing prism 6, the light is further separated by a prism 9, and one part is guided to a photodetector 10 for reading the header part, and the other part is converted by an analyzer 12 into a change in polarization angle into a change in light intensity. The latter is guided to a photodetector 13 for reading the data section.
次にトラツキング(TR)動作について説明す
る。ヘツダー用光検出器10は、ヘツダー部読み
取りを兼ねる。この検出器は2分割されており2
分割検出器の出力は、TRサーボ回路14に入力
される。デイスク1のトラツク方向の変動に対し
てサーボ回路14の出力に応じてガルバノミラー
7を駆動させてトラツキングさせる。デイスク半
径方向の大きな移動に対してはリニアモータ15
を駆動させ光ヘツド16全体を移動させる。 Next, tracking (TR) operation will be explained. The header photodetector 10 also serves to read the header portion. This detector is divided into two parts.
The output of the divided detector is input to the TR servo circuit 14. The galvanometer mirror 7 is driven in accordance with the output of the servo circuit 14 to perform tracking as the disk 1 changes in the tracking direction. A linear motor 15 is used for large movements in the disk radial direction.
is driven to move the entire optical head 16.
同様にAF動作はヘツダー用光検出器10で検
知された信号がAFサーボ回路17に入力され、
AF用ボイスコイル8内のオブジエクトレンズを
制御することにより行なわれる。 Similarly, for AF operation, a signal detected by the header photodetector 10 is input to the AF servo circuit 17,
This is done by controlling the object lens in the AF voice coil 8.
次にヘツダー用光検出器10及びデータ用光検
出器13で検知される信号形態について説明す
る。光磁気効果は磁化反転された部分へ照射され
たレーザ光が反射あるいは透過した場合、磁化の
向きによつて反射、透過光の偏光方向が互いに逆
向きに回転する効果である。既に第5図で記述し
た様に検光子12を用いることで、偏光面の回転
を、光強度の大小に変換して磁化の向きを検出す
る。ヘツダー信号は、凹凸型ピツトとして記録さ
れているため反射光量の直接的な変化量として検
知される。該ヘツダー信号の変調度は、光磁気効
果を利用して再生されたデータ信号にくらべ40〜
60dB以上大きいのが普通である。したがつて、
SN比良くヘツダー情報を読み取ることができる。 Next, the signal forms detected by the header photodetector 10 and the data photodetector 13 will be explained. The magneto-optical effect is an effect in which when laser light irradiated to a magnetized portion is reflected or transmitted, the polarization directions of the reflected and transmitted light rotate in opposite directions depending on the direction of magnetization. As already described in FIG. 5, by using the analyzer 12, the direction of magnetization is detected by converting the rotation of the plane of polarization into the magnitude of the light intensity. Since the header signal is recorded as uneven pits, it is detected as a direct change in the amount of reflected light. The modulation degree of the header signal is 40 to
It is normal for it to be louder than 60dB. Therefore,
Header information can be read with a good signal-to-noise ratio.
一方、データ信号をS/N良く再生する方法と
して、差動検出の方法が公知である。しかし、こ
の方法では、ヘツダー信号は、キヤンセルしてし
まつて全く読めなくなる。さらに光磁気信号を差
動で読み出し、ヘツダー信号を同相で読み出す方
式は、回路方式が、複雑化する。 On the other hand, a differential detection method is known as a method for reproducing data signals with good S/N ratio. However, with this method, the header signal is canceled and becomes completely unreadable. Furthermore, the circuit system becomes complicated in a system in which the magneto-optical signals are read out differentially and the header signals are read out in phase.
この様にヘツダ信号とデータ信号は、検出方
法、信号レベルが異なるため、本実施例に示した
様に個別の検出手段を設けるのが有利である。 Since the header signal and the data signal have different detection methods and signal levels, it is advantageous to provide separate detection means as shown in this embodiment.
ここで問題となるのは、ヘツダー信号とデータ
信号のレベル合わせの方式である。第6図にレベ
ル合わせの問題を対処するための具体的な実施例
を示す。 The problem here is the method of level matching between the header signal and the data signal. FIG. 6 shows a concrete example for dealing with the problem of level matching.
第6図aについて説明する。10,13はそれ
ぞれ第5図に示したヘツダー用光検出器とデータ
用光検出器である。61,62は光検出器で検知
された光電流情報を電流電圧変換する前段増幅器
(プリアンプ)である。前述のようにヘツダー信
号はデータ信号に比較しレベルが大きいので、増
幅器62の後に利得調整の可能な増幅段63を設
け、信号レベルのアジヤストを行なう。もし増幅
器61,62でのSN比が十分確保されているの
であれば、この逆に増幅器61の後に可変アツテ
ネータを挿入し信号レベルのアジヤストを行なつ
てもよい。64は、このように処理されたそれぞ
れの信号を加算する回路である。簡単な方法とし
ては演算増幅器を用いた加算器が利用できる。6
5は、アナログコンパレータを用いたロジツクレ
ベル信号への変換回路である。 FIG. 6a will be explained. Reference numerals 10 and 13 are a header photodetector and a data photodetector shown in FIG. 5, respectively. Reference numerals 61 and 62 denote front-stage amplifiers (preamplifiers) that convert photocurrent information detected by a photodetector into current and voltage. As mentioned above, since the header signal has a higher level than the data signal, an amplification stage 63 whose gain can be adjusted is provided after the amplifier 62 to adjust the signal level. If the SN ratio of the amplifiers 61 and 62 is sufficiently secured, a variable attenuator may be inserted after the amplifier 61 to adjust the signal level. 64 is a circuit that adds the respective signals processed in this way. As a simple method, an adder using an operational amplifier can be used. 6
5 is a logic level signal conversion circuit using an analog comparator.
次に第6図bについて説明する。光検出器1
0,13及び前段増幅器61,62までの構成は
第6図aと同様である。本実施例ではアナログ信
号の段階での信号レベルのアジヤストは行なわ
ず、それぞれアナログコンパレータ66,67を
用いてロジツクレベル信号に変換した後に、OR
ゲート68によつて信号を合成する点が第6図a
との相異点である。信号自身のSN比が十分確保
されていれば、一般にアナログ信号よりはロジツ
ク信号の方が取り扱いの点で便利であることが多
いので第6図bの方式が優位である。 Next, FIG. 6b will be explained. Photodetector 1
The configuration up to 0, 13 and pre-stage amplifiers 61, 62 is the same as that shown in FIG. 6a. In this embodiment, the signal level is not adjusted at the analog signal stage, but after converting to logic level signals using analog comparators 66 and 67, the OR
The point where the signals are combined by the gate 68 is shown in FIG. 6a.
This is the difference between As long as the signal-to-noise ratio of the signal itself is sufficiently secured, the method shown in FIG. 6b is superior because logic signals are generally more convenient to handle than analog signals.
さらに再生専用光デイスクや従来型のピツト記
録された書き換え不可の光デイスクに対してはヘ
ツダー用光検出器10で検知された信号をヘツダ
ー部はもちろんデータ部の情報として用いること
により対応させることが出来る。従つて、本発明
の光デイスク装置では、光磁気デイスク、書き換
え不可の光デイスク、再生専用光デイスクの3種
の光デイスクを扱うことができる。 Furthermore, for read-only optical discs and conventional pit-recorded non-rewritable optical discs, the signal detected by the header photodetector 10 can be used as information for the data part as well as the header part. I can do it. Therefore, the optical disc device of the present invention can handle three types of optical discs: magneto-optical discs, non-rewritable optical discs, and read-only optical discs.
本発明によれば、光磁気デイスクに予め記録ト
ラツクに対応して案内溝を設け、ヘツダー情報は
ピツトとして予め設けておき、再生手段としては
デイスク面からの光量変化を検知する検出器と、
光磁気効果を利用した偏光面回転を検知する検出
器を個別に有することにより、光磁気デイスクに
対しても従来型光デイスクと同様にセクター単位
での取扱いを可能にする。更には、同一のハード
構成を用いて、従来型光デイスクと光磁気デイス
クとの兼用が可能になる。
According to the present invention, guide grooves are provided in advance on the magneto-optical disk corresponding to the recording tracks, header information is provided in advance as pits, and the reproducing means includes a detector that detects changes in the amount of light from the disk surface;
By individually having a detector that detects the rotation of the polarization plane using the magneto-optical effect, it is possible to handle magneto-optical disks in units of sectors in the same way as conventional optical disks. Furthermore, the same hardware configuration can be used for both conventional optical disks and magneto-optical disks.
第1図は本発明による光磁気デイスクを示す
図、第2図は未記録トラツク形態を示す断面図、
第3図はヘツダー情報記録部分のトラツク形態を
示す断面図、第4図は具体的な光磁気デイスク構
造例を示す断面図、第5図は光ヘツド部の実施例
を示す構成図、第6図はa,bはヘツダー信号と
データ信号のレベル調整を行なうための回路構成
例を示す図である。
1……光磁気デイスク、2……案内溝、3……
ピツト(ヘツダー情報)、4……半導体レーザ光
源、8……オートフオーカス用ボイスコイル、9
……プリズム、10……ヘツダー信号用光検出
器、13……データ信号用光検出器、16……光
ヘツド。
FIG. 1 is a diagram showing a magneto-optical disk according to the present invention, FIG. 2 is a sectional view showing an unrecorded track form,
3 is a sectional view showing the track form of the header information recording portion, FIG. 4 is a sectional view showing a specific example of the magneto-optical disk structure, FIG. 5 is a configuration diagram showing an example of the optical head portion, Figures a and b show examples of circuit configurations for adjusting the levels of header signals and data signals. 1... magneto-optical disk, 2... guide groove, 3...
pit (header information), 4... semiconductor laser light source, 8... voice coil for autofocus, 9
... Prism, 10... Photodetector for header signal, 13... Photodetector for data signal, 16... Optical head.
Claims (1)
媒体に光スポツトとして収束する光学系と、上記
記録媒体から戻る光の光量の変化を検出する第1
の検出系と、上記記録媒体から戻る光の偏光角の
変化を検出する第2の検出系と、上記第1の検出
系の出力と第2の検出系の出力のレベルをアジヤ
ストする利得調整手段と、アジヤストされた第1
及び第2の検出系の出力が入力される共通の信号
処理系とを有することを特徴とする光学的情報記
憶装置。 2 前記記録媒体は円盤形状であり、光磁気効果
を有する記録膜と、径方向に間隔をおいて周方向
に延在する案内溝を有し、該案内溝が周方向に複
数のセクターに分割されており、各々のセクター
の一部に凹凸ピツトの状態でヘツダー信号が記録
されていることを特徴とする特許請求の範囲第1
項記載の光学的情報記憶装置。 3 前記第1の検出系は、2分割の光検出器を有
し、該2分割の光検出器の出力に基づいて前記記
録媒体の径方向における光スポツト照射位置を制
御するトラツキングサーボ回路を有することを特
徴とする特許請求の範囲第2項または第3項記載
の光学的情報記憶装置。 4 前記第1の検出系は、2分割の光検出器を有
し、該2分割の光検出器の出力に基づいて前記記
録媒体上の光スポツトのAF動作を制御するAFサ
ーボ回路を有することを特徴とする特許請求の範
囲第2項記載の光学的情報記憶装置。 5 前記第2の検出系は、前記記録媒体からの光
の偏光面の回転を光量変化に変換する検光子と、
該光量変化を光電変換により検出する光検出器を
有することを特徴とする特許請求の範囲第1項乃
至第4項のうちいずれかに記載の光学的情報記憶
装置。 6 前記利得調整手段は、利得調整可能な増幅段
または可変アツテネータで構成されることを特徴
とする特許請求の範囲第1項乃至第5項のうちい
ずれかに記載の光学的情報記憶装置。 7 レーザ光源と、該レーザ光源からの光を記録
媒体に光スポツトとして収束する光学系と、上記
記録媒体から戻る光の光量の変化を検出する第1
の検出系と、上記記録媒体から戻る光の偏光角の
変化を検出する第2の検出系と、上記第1の検出
系の出力をロジツクレベル信号に変換する手段
と、上記第2の検出系の出力をロジツクレベル信
号に変換する手段と、ロジクレベル信号に変換さ
れた第1及び第2の検出系の出力が入力される共
通の信号処理系とを有することを特徴とする光学
的情報記憶装置。 8 前記記録媒体は円盤形状であり、光磁気効果
を有する記録膜と、径方向に間隔をおいて周方向
に延在する案内溝を有し、該案内溝が周方向に複
数のセクターに分割されており、各々のセクター
の一部に凹凸ピツトの状態でヘツダー信号が記録
されていることを特徴とする特許請求の範囲第7
項記載の光学的情報記憶装置。 9 前記第1の検出系は、2分割の光検出器を有
し、該2分割の光検出器の出力に基づいて前記記
録媒体の径方向における光スポツト照射位置を制
御するトラツキングサーボ回路を有することを特
徴とする特許請求の範囲第8項記載の光学的情報
記憶装置。 10 前記第1の検出系は、2分割の光検出器を
有し、該2分割の光検出器の出力に基づいて前記
記録媒体上の光スポツトのAF動作を制御するAF
サーボ回路を有することを特徴とする特許請求の
範囲第8項または第9項記載の光学的情報記憶装
置。 11 前記第2の検出系は、前記記録媒体からの
光の偏光面の回転を光量変化に変換する検光子
と、該光量変化を光量変換により検出する光検出
器を有することを特徴とする特許請求の範囲第7
項乃至第10項のうちいずれかに記載の光学的情
報記憶装置。[Claims] 1. A laser light source, an optical system that converges light from the laser light source as a light spot on a recording medium, and a first system that detects changes in the amount of light returning from the recording medium.
a detection system, a second detection system for detecting a change in the polarization angle of the light returning from the recording medium, and a gain adjustment means for adjusting the levels of the output of the first detection system and the output of the second detection system. And the first one that was adjusted
and a common signal processing system into which the output of the second detection system is input. 2. The recording medium is disk-shaped and has a recording film having a magneto-optical effect and a guide groove extending in the circumferential direction at intervals in the radial direction, and the guide groove is divided into a plurality of sectors in the circumferential direction. Claim 1 characterized in that the header signal is recorded in a state of uneven pits in a part of each sector.
Optical information storage device as described in Section 1. 3. The first detection system has a two-divided photodetector, and a tracking servo circuit that controls the irradiation position of the light spot in the radial direction of the recording medium based on the output of the two-divided photodetector. An optical information storage device according to claim 2 or 3, characterized in that: 4. The first detection system has a two-divided photodetector, and an AF servo circuit that controls the AF operation of the optical spot on the recording medium based on the output of the two-divided photodetector. An optical information storage device according to claim 2, characterized in that: 5. The second detection system includes an analyzer that converts rotation of the polarization plane of the light from the recording medium into a change in light amount;
5. The optical information storage device according to claim 4, further comprising a photodetector that detects the change in the amount of light by photoelectric conversion. 6. The optical information storage device according to any one of claims 1 to 5, wherein the gain adjustment means is comprised of an amplification stage whose gain is adjustable or a variable attenuator. 7 a laser light source, an optical system that converges the light from the laser light source as a light spot on a recording medium, and a first system that detects changes in the amount of light returning from the recording medium.
a second detection system for detecting a change in the polarization angle of the light returning from the recording medium; a means for converting the output of the first detection system into a logic level signal; An optical information storage device comprising means for converting an output into a logic level signal, and a common signal processing system into which the outputs of the first and second detection systems converted into logic level signals are input. 8. The recording medium is disk-shaped and has a recording film having a magneto-optical effect and a guide groove extending in the circumferential direction at intervals in the radial direction, and the guide groove is divided into a plurality of sectors in the circumferential direction. Claim 7, characterized in that the header signal is recorded in a state of uneven pits in a part of each sector.
Optical information storage device as described in Section 1. 9 The first detection system has a two-divided photodetector, and a tracking servo circuit that controls the irradiation position of the light spot in the radial direction of the recording medium based on the output of the two-divided photodetector. An optical information storage device according to claim 8, characterized in that it has: 10 The first detection system has a two-divided photodetector, and an AF that controls the AF operation of the optical spot on the recording medium based on the output of the two-divided photodetector.
10. The optical information storage device according to claim 8, further comprising a servo circuit. 11 A patent characterized in that the second detection system includes an analyzer that converts the rotation of the polarization plane of the light from the recording medium into a change in light amount, and a photodetector that detects the change in light amount by converting the light amount. Claim No. 7
The optical information storage device according to any one of items 1 to 10.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP24200683A JPS60136047A (en) | 1983-12-23 | 1983-12-23 | Photomagnetic processing system |
US07/053,564 US4985881A (en) | 1983-12-23 | 1987-05-21 | Record carrier for a magneto-optical disc memory having guide grooves of a plurality of tracks disposed with a predetermined relation to light spot diameter |
US07/617,006 US5161135A (en) | 1983-12-23 | 1990-11-21 | Magneto-optical disc memory apparatus including a header signal and magneto-optical signal level adjusting circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP24200683A JPS60136047A (en) | 1983-12-23 | 1983-12-23 | Photomagnetic processing system |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS60136047A JPS60136047A (en) | 1985-07-19 |
JPH0552574B2 true JPH0552574B2 (en) | 1993-08-05 |
Family
ID=17082853
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP24200683A Granted JPS60136047A (en) | 1983-12-23 | 1983-12-23 | Photomagnetic processing system |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS60136047A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07105081B2 (en) * | 1985-01-23 | 1995-11-13 | 株式会社日立製作所 | Magneto-optical disk device and information processing method thereof |
-
1983
- 1983-12-23 JP JP24200683A patent/JPS60136047A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS60136047A (en) | 1985-07-19 |
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