JPS6116042A - Optical information recorder - Google Patents

Optical information recorder

Info

Publication number
JPS6116042A
JPS6116042A JP59136492A JP13649284A JPS6116042A JP S6116042 A JPS6116042 A JP S6116042A JP 59136492 A JP59136492 A JP 59136492A JP 13649284 A JP13649284 A JP 13649284A JP S6116042 A JPS6116042 A JP S6116042A
Authority
JP
Japan
Prior art keywords
recording
light
bit
output
recording medium
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
Application number
JP59136492A
Other languages
Japanese (ja)
Inventor
Masaharu Tsukada
塚田　雅晴
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Priority to JP59136492A priority Critical patent/JPS6116042A/en
Publication of JPS6116042A publication Critical patent/JPS6116042A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
    • G02B1/14—Protective coatings, e.g. hard coatings
    • 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
    • G11B7/0045—Recording
    • 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
    • G11B7/125—Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for controlling the size or intensity of optical spots or optical traces
    • G11B7/126—Circuits, methods or arrangements for laser control or stabilisation

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • General Physics & Mathematics (AREA)
  • Optical Head (AREA)
  • Semiconductor Lasers (AREA)

Abstract

PURPOSE:To obtain the optimum form of a recording bit and to improve the S/N of a reproduction signal by controlling the light emitting output of a light source in response to the difference of light quantity between both secondary beams that are reflected by a recording medium or transmitted through the recording medium. CONSTITUTION:The laser light of a semiconductor laser 7 is divided by a grating 5 into a 0-order main beam and + or -1-order secondary beams. An information bit 25 is formed by the 0-order light 24, and the formation of the bit 25 is detected by a secondary beam 26. While a secondary beam 27 is irradiated to an unrecorded part. The outputs of sensors 14 and 15 of beams 27 and 26 undergo the voltage conversions 16 and 17 and then the difference of both outputs is obtained. Then only the detection signal of the bit 25 is obtained and supplied to an LPF19. When a recording bit has a smaller form than the optimum bit, the output VC of the LPF19 is reduced. A current source 20 compares the voltage VC with the set voltage V0 of an input part 21 and increases the output current according to an amount of reduction. Thus the light emitting output of the laser 7 is increased.

Description

【発明の詳細な説明】 〔技術分野〕 本発明は光学式情報記録装置の改良に係り、特に記憶媒
体に情報を記録する時、良好な形状を有する記録ビット
を得ることができる光学式情報記録装置に関する。Detailed Description of the Invention [Technical Field] The present invention relates to an improvement of an optical information recording device, and particularly an optical information recording device that can obtain recorded bits having a good shape when recording information on a storage medium. Regarding equipment.

〔従来技術〕[Prior art]

一般に、ガラス円板にＧｄ　、　Ｔｂ　、　Ｆｅ等の組
成から成る磁性膜をスパッタリング等によって蒸着した
記録媒体に半導体レーザ等によって情報を記録し、又こ
のように記録された情報を再生する光学式情報記録再生
装置に於て、再生信号の８７４１比を向上させることは
、エラーレートの改善等に関して重要なことである。こ
のため従来Ｓ／／Ｎ比を改善させるために、再生信号の
レベルに応じて記録レーザのレーザパワーを変えて、再
生信号のレベルが一定となる様な制御が存した。しかし
ながら、上記の様な制御方法では、再生信号のＳハ比が
媒体面上に形成された情報ビット形状に依存しているこ
とから、φ比の改善に於て限界があった。Generally, information is recorded on a recording medium in which a magnetic film made of a composition of Gd, Tb, Fe, etc. is deposited on a glass disk by sputtering or the like, using a semiconductor laser or the like, and optical information is used to reproduce the information recorded in this way. In a recording/reproducing device, improving the 8741 ratio of a reproduced signal is important in terms of improving error rate and the like. For this reason, conventionally, in order to improve the S//N ratio, there has been a control method in which the laser power of the recording laser is changed depending on the level of the reproduced signal so that the level of the reproduced signal is kept constant. However, with the above control method, there is a limit to the improvement of the φ ratio because the S/c ratio of the reproduced signal depends on the shape of the information bits formed on the medium surface.

なぜなら情報ビットの形状は、媒体面の感度ムラ、書き
込みレーデパワーの変動、バイアス磁界の変動、或いは
フォーカス精度等により変化し、この情報ビットの形状
の不均一が再生信号のＳ／Ｎ比の劣化の原因となるから
である。This is because the shape of the information bit changes due to unevenness in the sensitivity of the medium surface, fluctuations in write radar power, fluctuations in the bias magnetic field, focus accuracy, etc., and this non-uniformity in the shape of the information bit causes the deterioration of the S/N ratio of the reproduced signal. This is because it becomes a cause.

〔目的〕〔the purpose〕

そこで本発明の目的は前記欠点を除去すべく記録媒体上
に最適な形状を有する情報ビットを形成し、高いＳ／Ｎ
比を有する再生信号を再生しうる、光学式情報記録装置
を提供することにある。Therefore, an object of the present invention is to form information bits having an optimal shape on a recording medium in order to eliminate the above-mentioned drawbacks, and to achieve a high S/N ratio.
An object of the present invention is to provide an optical information recording device capable of reproducing a reproduction signal having a high ratio.

〔構成〕〔composition〕

前記目的を達成すべく本発明は光源から発した記録ビー
ムを記録媒体に照射し、情報の記録を行なう光学式情報
記録装置において、前記記録ビームの他に、一方が記録
媒体の未記録部、他方が前記記録ビームによる記録媒体
の記録部に照射されるように配された１組の副ビームを
設け、前記記録媒体で反射又は透過された夫々の副ビー
ムの光量差を検知して、この光量差に応じて前記光源の
発光出力を制御する事を特徴とする。In order to achieve the above object, the present invention provides an optical information recording apparatus that records information by irradiating a recording beam emitted from a light source onto a recording medium. A set of sub-beams is provided, the other of which is arranged so that the recording section of the recording medium is irradiated by the recording beam, and the difference in light intensity between the respective sub-beams reflected or transmitted by the recording medium is detected. It is characterized in that the light emission output of the light source is controlled according to the difference in light amount.

〔実施例〕〔Example〕

以下図面に基づいて本発明の実施例を具体的かつ詳細に
説明する。Embodiments of the present invention will be described in detail below based on the drawings.

第１図は、本発明に関する構成を示したものである。１
は、Ｇｄ　、　Ｔ’ｂ　、　Ｆｅ等で形成された記録媒
体であり、スピンドルモータ２によって図中Ａ方向に回
転するものである。本実施例に係る光学ヘッドは記録再
生兼用のものである。従って、光源である半導体レーザ
７から発せられたレーザ光はコリメータレンズ６によっ
て平行光にされた後。FIG. 1 shows a configuration related to the present invention. 1
is a recording medium made of Gd, T'b, Fe, etc., and is rotated in the direction A in the figure by a spindle motor 2. The optical head according to this embodiment is used for both recording and reproduction. Therefore, after the laser light emitted from the semiconductor laser 7 which is the light source is made into parallel light by the collimator lens 6.

グレーティング５によって０次と±１次の３ビームに分
割される。上記３ビームは偏向ビームスプリッタ４を透
過し、対物レンズ３によって記録媒体１面上に焦点を結
ぶ。記録時は、この３ビ一ム００次光が記録ビームとし
て使用され、記録媒体１に情報ビットを形成する。また
、±１次光は副ビームとして、記録時には光源の発光出
力の制御、再生時には記録ビームを正しく情報ビットに
導く為のトラッキングに用いられる。この内、後者のト
ラッキングに関しては、一般に３ビーム法として広く知
られており、ここでは詳述しない。前記３ビームは、記
録媒体１面から反射され、対物レンズ３を透過してビー
ムスプリッタ４によって反射され、偏向板１２へ向かう
。偏向板１２は、入射された光のある偏向面のみを透過
する。つまり偏向板１２を光が透過することにより信号
成分が光学的に検出される。さらに前記反射光は、シリ
ンドリカルレンズ８により非点収・差を受け、円レンズ
９によってセンサ１０上に３ビームのスポットが当る。The grating 5 divides the beam into three beams of 0th order and ±1st order. The three beams pass through a polarizing beam splitter 4 and are focused onto a recording medium 1 by an objective lens 3. During recording, this 3-beam 00th-order light is used as a recording beam to form information bits on the recording medium 1. Further, the ±1st-order light is used as a sub beam to control the light emission output of the light source during recording, and for tracking to correctly guide the recording beam to the information bit during reproduction. Of these, the latter tracking method is generally widely known as the three-beam method, and will not be described in detail here. The three beams are reflected from the surface of the recording medium 1, transmitted through the objective lens 3, reflected by the beam splitter 4, and directed toward the deflection plate 12. The polarizing plate 12 transmits only a certain polarizing surface of the incident light. That is, the signal component is optically detected by the light passing through the deflection plate 12. Further, the reflected light is subjected to astigmatism and difference by the cylindrical lens 8, and three beam spots are applied to the sensor 10 by the circular lens 9.

１１はセンサ１０を拡大表示したものであり、中央に再
生信号の検知及びオートフォーカスのための４分割セン
サ１３を有し、その両側にトラッキングのための副ビー
ム（±１次光）をセンスするための第１及び第２光セン
サ１４，１５が配置される。Reference numeral 11 shows an enlarged view of the sensor 10, which has a 4-split sensor 13 in the center for detecting reproduction signals and autofocusing, and senses sub-beams (±1st order light) for tracking on both sides. First and second optical sensors 14 and 15 are arranged for this purpose.

第１及び第２光センサによって検知された±１次光に対
応する電気信号は、第１及び第２Ｉ−Ｖ変換器１６．１
７によってそれぞれ電圧信号に変換される。この両信号
は次段の差動増巾器１８によってその差分がとられる。The electrical signals corresponding to the ±1st order light detected by the first and second optical sensors are transmitted to the first and second I-V converters 16.1.
7, each is converted into a voltage signal. The difference between these two signals is taken by a differential amplifier 18 at the next stage.

さらに、差動増巾器１８の出力はローパスフィルタ１９
によって情報ビット毎に発生する信号の平均値が得られ
る。このローパスフィルタ１９の出力電圧ｖ０を電流源
２０に入力する。Furthermore, the output of the differential amplifier 18 is filtered by a low pass filter 19.
The average value of the signal generated for each information bit can be obtained by The output voltage v0 of this low-pass filter 19 is input to the current source 20.

電流源２０は出力電圧Ｖ。と設定電圧入力部２１からの
設定電圧Ｖ。どの差に応じて電流源２０から出力される
電流値を変えることができる。電流源２０の出力はカレ
ントスイッチ回路２２に入力される。該カレントスイッ
チ回路２２は画像信号入力部２３から送られる１、０の
画像信号によってスイッチング動作を行ない半導体レー
デ７の発光のＯＮ　、　ＯＦＦをするものであり、電流
源２０からの出力電流値の大きさに応じて半導体レーザ
７を駆動する電流値が変えられる。Current source 20 has an output voltage V. and the set voltage V from the set voltage input section 21. The current value output from the current source 20 can be changed depending on the difference. The output of current source 20 is input to current switch circuit 22 . The current switch circuit 22 performs a switching operation in response to the 1 and 0 image signals sent from the image signal input section 23 to turn on and off the light emission of the semiconductor radar 7, and the current switch circuit 22 changes the output current value from the current source 20 to turn on and off the light emission of the semiconductor radar 7. The current value for driving the semiconductor laser 7 can be changed depending on the current value.

次に作用について説明する。第２図は３ビームによる光
スポットと媒体面に形成される情報ビットとの位置関係
を示すもので、媒体面は、３ビームに対して矢印Ｂ方向
に移動し、０次光２４により、図で示される様な情報ビ
ット２５が形成される。図中、実線で示される情報ビッ
ト形状が最適であり、点線で示される形状は情報ビット
の書き込み不足である。ビット形状の検知は、記録ビー
ムの後に続く副ビーム（−１次光）２６によってなされ
る。つまり、最適なビット形状を形成できた場合は情報
ビット２５が一１次光２６０半分の面積だけ重なる様な
配置となっている。もし、点線で示されるビット形状の
場合は、光スポットと情報ビット２５との重なる面積が
少なくなり、光センサ１０によって検知される一１次光
の電気信号は小さくなる。その様子を第３図に示す。−
１次光２６が情報ビット２５を通過する毎に図に示され
る様に、電気信号の山が得られる。実線で示される情報
ビット２５から得られる電気信号は、第３図の実線で示
され、点線で示される情報ビット２５から得られる電気
信号は点線で示している。Next, the effect will be explained. FIG. 2 shows the positional relationship between the light spot formed by the three beams and the information bit formed on the medium surface. Information bits 25 as shown are formed. In the figure, the information bit shape indicated by a solid line is optimal, and the shape indicated by a dotted line indicates insufficient writing of information bits. The bit shape is detected by a sub beam (-1st order light) 26 following the recording beam. In other words, if an optimal bit shape can be formed, the information bits 25 are arranged so that they overlap by an area that is half the area of the 1st order light 260. In the case of the bit shape shown by the dotted line, the overlapping area of the light spot and the information bit 25 becomes smaller, and the electric signal of the primary light detected by the optical sensor 10 becomes smaller. The situation is shown in Figure 3. −
Each time the primary light 26 passes through the information bit 25, a pile of electrical signals is obtained, as shown in the figure. Electrical signals obtained from information bits 25 shown in solid lines are shown in solid lines in FIG. 3, and electrical signals obtained from information bits 25 shown in dotted lines are shown in dotted lines.

従って該検知信号の平均値をとれば、それは情報ビット
２５の形状に対応したものとなる。Therefore, if the average value of the detection signals is taken, it will correspond to the shape of the information bit 25.

ここで＋１次光の中で、記録ビームに先行する方の副ビ
ーム（＋１次光）２７は、媒体１面の反射光のみを検知
し、記録ビームの後にくる他方の副ビーム（−１次光）
２６は媒体面の反射光と情報ビットを検知するものであ
り、第１及び第２光センサ１４，１５は夫々１次光２７
及び−１次光２６を検知し、該第１及び第２光センサ１
４，１５の出力を第１及び第２Ｉ−Ｖ変換器１６．１７
で夫々電圧に変換した後、差動増巾器１８でその信号電
圧の差をとれば媒体１面の反射ムラ等に起因する検知電
圧の変動が除去され、情報ビット２５の検知信号のみが
差動増巾器１８から出力される。Here, among the +1st-order lights, the sub-beam (+1st-order light) 27 that precedes the recording beam detects only the reflected light from the first surface of the medium, and the other sub-beam (-1st-order light) that comes after the recording beam light)
26 detects reflected light from the medium surface and information bits, and the first and second optical sensors 14 and 15 detect primary light 27, respectively.
and −1-order light 26, and the first and second optical sensors 1
4 and 15 to the first and second I-V converters 16.17
After converting the signal voltages into voltages, the differential amplifier 18 calculates the difference between the signal voltages. Fluctuations in the detection voltage caused by uneven reflection on the surface of the medium, etc. are removed, and only the detection signal of the information bit 25 differs. It is output from the dynamic amplifier 18.

この差動増巾器１８の出力はローパスフィルタ１９に入
力され検知信号の平均値がとられる。もし記録ビットの
形状が最適なビット形状より小さくなると、ローノやス
フィルタ１９より出力される電圧ｖｅは減少する。電流
源２０ではこの電圧ｖｃを設定電圧■。と比較し、電圧
Ｖ。の減少分に応じて電流源２０から出力される電流値
が増大する。その結果、半導体レーザ７の発光出力は増
大する。The output of the differential amplifier 18 is input to a low pass filter 19, and the average value of the detection signals is taken. If the shape of the recording bit becomes smaller than the optimum bit shape, the voltage ve output from the ronos filter 19 decreases. In the current source 20, this voltage VC is set as the set voltage ■. compared to the voltage V. The current value output from the current source 20 increases in accordance with the decrease in . As a result, the light emission output of the semiconductor laser 7 increases.

そしてローパスフィルタ１９からの出力電圧ｖｃと設定
電圧入力部２１からの設定電圧Ｖ。どの差がなくなるま
で半導体レーデ７の発光出力が増大し、出力電圧ｖｃと
設定電圧ｖ０とが等しくなると半導体レーザ７の発光出
力は一定となる。Then, the output voltage vc from the low-pass filter 19 and the set voltage V from the set voltage input section 21. The light emitting output of the semiconductor laser 7 increases until the difference disappears, and when the output voltage vc and the set voltage v0 become equal, the light emitting output of the semiconductor laser 7 becomes constant.

しかして第３図において点線で示される様な情報ビット
が検知された場合、半導体レーザの発光出力を増大させ
ること圧よって、実線で示されるビット形状となる様に
制御される。When an information bit as shown by the dotted line in FIG. 3 is detected, the light emitting output of the semiconductor laser is increased to control the bit shape to become the bit shape shown by the solid line.

〔効果〕〔effect〕

以上詳細かつ具体的に説明した如く本発明によれば記録
ビットを最適の形状にできるため再生信号のＳ／Ｎ比を
高めるために極めて有効である。さらに記録ビームの他
に、副ビームを使用して記録ビットをモニターするため
、はぼリアルタイムに近い状態で記録ビットの最適化が
計れ、記録ビットを最適化するための余分な動作シーケ
ンスを不用とできる。また、１組の副ビームの差をとる
形で記録ビットのモニターがなされるため、媒体面の反
射ムシに起因する記録ビットの検知信号の変動による影
響を除去し得る。As described above in detail and specifically, the present invention allows recording bits to have an optimal shape, which is extremely effective for increasing the S/N ratio of reproduced signals. Furthermore, in addition to the recording beam, the recording bits are monitored using a sub-beam, making it possible to optimize the recording bits in near real-time, eliminating the need for extra operation sequences for optimizing the recording bits. can. Furthermore, since the recording bits are monitored by taking the difference between a set of sub beams, it is possible to eliminate the influence of fluctuations in the detection signal of the recording bits caused by reflection bugs on the medium surface.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明の１実施例に係る光学式情報記録再生装
置の構成原理図、第２図は記録媒体上の情報ビット及び
光スポットの状態を示す説明図、第３図は検知信号のタ
イムチャートである。 図において １・・・記録媒体、７・・・半導体レーザ、１６・・・
第１１−Ｖ変換器、１７・・・第２Ｉ−Ｖ変換器、１８
・・・差動増巾器、１９・・・ローパスフィルタ、２０
・・・電流源、２２・・・カレントスイッチ回路、であ
る。 第１図 第２図FIG. 1 is a diagram showing the configuration principle of an optical information recording/reproducing device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the states of information bits and light spots on a recording medium, and FIG. 3 is a diagram of the detection signal. This is a time chart. In the figure, 1...recording medium, 7...semiconductor laser, 16...
11th-V converter, 17...2nd I-V converter, 18
... Differential amplifier, 19 ... Low pass filter, 20
. . . current source, 22 . . . current switch circuit. Figure 1 Figure 2

Claims (1)

【特許請求の範囲】[Claims] （１）光源から発した記録ビームを記録媒体に照射し、
情報の記録を行なう光学式情報記録装置において、前記
記録ビームの他に、一方が記録媒体の未記録部、他方が
前記記録ビームによる記録媒体の記録部に照射されるよ
うに配された１組の副ビームを設け、前記記録媒体で反
射又は透過された夫々の副ビームの光量差を検知して、
この光量差に応じて前記光源の発光出力を制御する事を
特徴とする光学式情報記録装置。(1) Irradiate the recording medium with a recording beam emitted from a light source,
In an optical information recording device for recording information, in addition to the recording beam, one set is arranged such that one side is irradiated with an unrecorded part of the recording medium and the other side is irradiated with the recorded part of the recording medium by the recording beam. providing sub-beams, and detecting the difference in light amount of each sub-beam reflected or transmitted by the recording medium,
An optical information recording device characterized in that the light emission output of the light source is controlled according to this difference in light amount.
JP59136492A 1984-07-03 1984-07-03 Optical information recorder Pending JPS6116042A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59136492A JPS6116042A (en) 1984-07-03 1984-07-03 Optical information recorder

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59136492A JPS6116042A (en) 1984-07-03 1984-07-03 Optical information recorder

Publications (1)

Publication Number Publication Date
JPS6116042A true JPS6116042A (en) 1986-01-24

Family

ID=15176418

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59136492A Pending JPS6116042A (en) 1984-07-03 1984-07-03 Optical information recorder

Country Status (1)

Country Link
JP (1) JPS6116042A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2613866A1 (en) * 1987-04-07 1988-10-14 Mitsubishi Electric Corp OPTICAL INFORMATION RECORDING AND REPRODUCING APPARATUS
JPH05282695A (en) * 1992-03-31 1993-10-29 Taiyo Yuden Co Ltd Optical information recording device
US5693366A (en) * 1989-06-20 1997-12-02 Nippon Sheet Glass Co., Ltd. Process for producing plastic lens comprising a primer layer, a hard coat layer and an antireflection coating

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2613866A1 (en) * 1987-04-07 1988-10-14 Mitsubishi Electric Corp OPTICAL INFORMATION RECORDING AND REPRODUCING APPARATUS
US5693366A (en) * 1989-06-20 1997-12-02 Nippon Sheet Glass Co., Ltd. Process for producing plastic lens comprising a primer layer, a hard coat layer and an antireflection coating
JPH05282695A (en) * 1992-03-31 1993-10-29 Taiyo Yuden Co Ltd Optical information recording device

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