JPS61125098A - Light output stabilizer - Google Patents

Light output stabilizer

Info

Publication number
JPS61125098A
JPS61125098A JP59246902A JP24690284A JPS61125098A JP S61125098 A JPS61125098 A JP S61125098A JP 59246902 A JP59246902 A JP 59246902A JP 24690284 A JP24690284 A JP 24690284A JP S61125098 A JPS61125098 A JP S61125098A
Authority
JP
Japan
Prior art keywords
signal
output
pid
light source
circuit
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.)
Granted
Application number
JP59246902A
Other languages
Japanese (ja)
Other versions
JPH067612B2 (en
Inventor
Seiji Yoshikawa
省二 吉川
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.)
Olympus Corp
Original Assignee
Olympus Optical Co Ltd
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 Olympus Optical Co Ltd filed Critical Olympus Optical Co Ltd
Priority to JP59246902A priority Critical patent/JPH067612B2/en
Priority to DE3546645A priority patent/DE3546645C2/de
Priority to DE3546599A priority patent/DE3546599C2/de
Priority to DE19853541002 priority patent/DE3541002A1/en
Publication of JPS61125098A publication Critical patent/JPS61125098A/en
Priority to US07/169,106 priority patent/US4858219A/en
Publication of JPH067612B2 publication Critical patent/JPH067612B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording 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
    • G11B7/12Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/125Optical 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
    • G11B7/126Circuits, methods or arrangements for laser control or stabilisation
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B19/00Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
    • G11B19/02Control of operating function, e.g. switching from recording to reproducing
    • G11B19/04Arrangements for preventing, inhibiting, or warning against double recording on the same blank or against other recording or reproducing malfunctions
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording 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
    • G11B7/002Recording, reproducing or erasing systems characterised by the shape or form of the carrier
    • G11B7/0037Recording, reproducing or erasing systems characterised by the shape or form of the carrier with discs
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording 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
    • G11B7/08Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/085Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam into, or out of, its operative position or across tracks, otherwise than during the transducing operation, e.g. for adjustment or preliminary positioning or track change or selection
    • G11B7/08547Arrangements for positioning the light beam only without moving the head, e.g. using static electro-optical elements

Abstract

PURPOSE:To stabilize light output in real time, by performing the PID control of an error signal, which is obtained by comparing an electric signal corresponding to the amount of light emitted from a laser light source with a specified reference level. CONSTITUTION:The output signal from a comparator circuit 3 is inputted to a digital control circuit constituted by a window comparator and the like. The signal is also inputted to a differential amplifier constituting a PID control circuit through an analog switch 32. An analog switch 34 receives a W.GATE signal and a clock signal and controls an integrating controller as desired. The output signal of the PID control is superimposed on the output of a D-A converter 8, which receives the output signal of a digital control circuit. Thus a driver for a light source is controlled through a Zener diode 36. Therefore, the PID control of the error signal is performed together with the digital control, and the light output of the light source can be carried out in real time.

Description

【発明の詳細な説明】 発 の技術分 本発明は半導体レーザ等のレーザ光源の出力光部を、自
動的に所望のレベルに制御して安定した光出力を得るよ
うにした光出力安定化装置に関する。
[Detailed Description of the Invention] The present invention provides an optical output stabilizing device that automatically controls the output light section of a laser light source such as a semiconductor laser to a desired level to obtain stable optical output. Regarding.

″             と  。      へ
半導体レーザは、駆動電流(電圧)に対して非線形な光
出力特性を示す、このようなレーザ光源から安定した光
出力を得るためには、最適な駆動電流(電圧)の制御を
行うことが必要である。以下、半導体レーザを例にして
本発明および従来技術を説明するが、図面において同一
の構成要素には同一の符合を付して説明を省略する。
Semiconductor lasers exhibit nonlinear optical output characteristics with respect to driving current (voltage). In order to obtain stable optical output from such laser light sources, optimal control of driving current (voltage) is required. Hereinafter, the present invention and the prior art will be explained using a semiconductor laser as an example, and the same components in the drawings will be given the same reference numerals and the explanation will be omitted.

第4図は従来の光出力安定化装置(Arc)の−例の構
成図である。レーザダイオードLDから発生された光束
の一部(LDの裏面から出た光束)はフォトダイオード
PDによって検出され、比較回路3に与えられる。また
、比較回路3には図示しない基準電圧発生回路から基準
電圧Vrefが与えられており、比較結果の信号(誤差
信号)は制御回路に22に午えられる。
FIG. 4 is a configuration diagram of an example of a conventional optical output stabilizing device (Arc). A part of the luminous flux generated from the laser diode LD (the luminous flux emitted from the back surface of the LD) is detected by the photodiode PD and provided to the comparator circuit 3. Further, the comparison circuit 3 is supplied with a reference voltage Vref from a reference voltage generation circuit (not shown), and a comparison result signal (error signal) is sent to the control circuit 22.

制御回路22は誤差信号が所定の範囲内で安定するよう
にレーザダイオードLDを制御する制御信号を出力し、
ドライバ23はこの制御信号にもとづいてレーザダイオ
ードLDを駆動する。
The control circuit 22 outputs a control signal to control the laser diode LD so that the error signal is stabilized within a predetermined range,
The driver 23 drives the laser diode LD based on this control signal.

上記のように従来は、レーザダイオードLDからの光束
の一部をフォトダイオード(光センf)FDで受光し、
比較回路23から制御回路と、ドライバ23へと続く閉
ループ制御によってレーザダイオード(レーザ光源)L
Dの発光光量を制御している。従って1発光光量の制御
はこの閉ループを信号が一巡しないとなされないため、
リアルタイム性に欠けるという問題点があった。
As mentioned above, conventionally, a part of the luminous flux from the laser diode LD is received by the photodiode (light sensor f) FD,
The laser diode (laser light source) L is controlled by the closed loop control from the comparison circuit 23 to the control circuit and the driver 23.
Controls the amount of light emitted by D. Therefore, the amount of light emitted per flash cannot be controlled until the signal passes through this closed loop.
The problem was that it lacked real-time performance.

、     I      の     目     
が本発明は上記の如き従来技術の欠点を克服するために
なされたもので、リアルタイムで光出力安定化を図るこ
とのできる光出力安定化装置を提供することを目的とす
る。
, I's eyes
However, the present invention has been made to overcome the drawbacks of the prior art as described above, and an object of the present invention is to provide a light output stabilizing device capable of stabilizing light output in real time.

の 上記の目的を達成するため本発明は、レーザ光源の発光
光量に応じた電気信号を所定の基準レベルと比較するこ
とにより誤差信号を得て、この誤差信号が所定の範囲内
で安定するようにレーザ光源の発光光量を制御する光出
力安定化装置において、誤差信号をP I D (Pr
oportional Integraland De
rivative) MmするためPID制御手段を設
けたことを特徴とする光出力安定化装置を提供するもの
である。
To achieve the above object, the present invention obtains an error signal by comparing an electric signal corresponding to the amount of light emitted from a laser light source with a predetermined reference level, and stabilizes the error signal within a predetermined range. In the optical output stabilization device that controls the amount of light emitted from the laser light source, the error signal is converted to PID (Pr
Portional Integraland De
The present invention provides an optical output stabilizing device characterized in that it is provided with a PID control means for controlling (rivative) Mm.

第1図は本発明の一実施例の概略構成図である。第4図
に示す従来例と異なる点は、比較回路3の出力側には制
御回路22と並列にPID回路24が設けられ、かつ、
′1iIIJ1回路22から出力された制御信号からP
 I D 4:f号を減じる減算器25が設けられてい
る点である。上記のように構成されているため、ドライ
バ23は制W@号からPID信号を減じた信号にもとづ
いてレーザダイオードLDを駆動する。
FIG. 1 is a schematic diagram of an embodiment of the present invention. The difference from the conventional example shown in FIG. 4 is that a PID circuit 24 is provided on the output side of the comparator circuit 3 in parallel with the control circuit 22, and
'1iIIJ1 from the control signal output from the circuit 22
ID 4: A subtracter 25 for subtracting the f number is provided. With the above configuration, the driver 23 drives the laser diode LD based on a signal obtained by subtracting the PID signal from the control signal W@.

第2図は第1図に示す実施例を具体化した回路図である
。レーザダイオードLDの出力光の一部(特に裏面から
出た光束)はフォトダイオードPDにより検出され、光
検出信号は増幅器3で増幅されて制御回路22を構成す
るウィンドコンパレータ 4に午えられ、あらかじめ設
定されたトド限レベルと比較される。また、ANDゲー
ト回路5にはウィンドコンパレータ 4を構成する2つ
のコンパレータのそれぞれの出力信号と、クロック信号
発生器6からのクロック信号とが入力されており、その
論理演算出力はアップダウンカウンタ(U/Dカウンタ
)7のアップ端子およびダウン端子に入力される。そし
て、U/Dカウンタ 7のjfl 力はD−Aコンバー
タ8でアナログ信号に変換され、減算器25に人力され
る。一方、増幅器3の出力はPID回路24に与えられ
ており、PID回路24はこれにもとづいてPID信号
を出力する。
FIG. 2 is a circuit diagram embodying the embodiment shown in FIG. A part of the output light of the laser diode LD (particularly the light flux emitted from the back surface) is detected by the photodiode PD, and the photodetection signal is amplified by the amplifier 3 and sent to the window comparator 4 that constitutes the control circuit 22. It is compared with the set limit level. Further, the output signals of the two comparators constituting the window comparator 4 and the clock signal from the clock signal generator 6 are input to the AND gate circuit 5, and the logical operation output is output from the up/down counter (U /D counter) 7's up and down terminals. Then, the jfl force of the U/D counter 7 is converted into an analog signal by the DA converter 8 and input to the subtracter 25 . On the other hand, the output of the amplifier 3 is given to the PID circuit 24, and the PID circuit 24 outputs a PID signal based on this.

従って、帰還抵抗11を有する演算増幅器10には、A
−Dコンバータ 8から出力された制御信号からPID
信号を減した信号が与えられているので、レーザダイオ
ードLDをドライブするトランジスタ13は[(〃制御
信号)−(PID信号)]によって制御されることにな
る。なお、この演算増幅器10、抵抗12およびトラン
ジスタ13によって第1図のドライバ23が構成されて
いる。
Therefore, in the operational amplifier 10 having the feedback resistor 11, A
- PID from the control signal output from D converter 8
Since the reduced signal is given, the transistor 13 that drives the laser diode LD is controlled by [(control signal)-(PID signal)]. Note that the operational amplifier 10, the resistor 12, and the transistor 13 constitute the driver 23 in FIG.

第3図は本発明を光学的情報記録再生装置に用いた実施
例での第2図に示すPID回路の詳細な回路図である。
FIG. 3 is a detailed circuit diagram of the PID circuit shown in FIG. 2 in an embodiment in which the present invention is applied to an optical information recording/reproducing apparatus.

図示の如<、ANDゲート2Bには記録ゲート信号(W
−GATE)とクロック信号が与えられており、その出
力はANDゲート31に与えられる。また、ANDゲー
ト31の他方の入力端子にはインバータ30を介してJ
[命令(適時にレーザダイオードの光量調整を実行する
ための信号)が与えられている。従って、再生時には増
幅器3の出力はスイッチ32を介してPID回路に入力
され、記録時には記録ゲート信号がハイレベル(以下°
“H”という)であって調整命令(ADJ−IN)がロ
ーレベル(以下“L″という)ときにのみANDゲート
31からクロック信号が出力され、ADJ−INループ
のと、!r(ADJ−INがH°゛)はPIDは制御し
ない。さらに、ANDゲー)31の出力はアナログスイ
ッチ32に与えられると共にインバータ33を介してア
ナログスイッチ34に与えられる。抵抗r、、r2と微
分コンデンサC1は微分回路を構成しており、抵抗r3
とアすaグスイッチ34に並列接続された積分コンデン
サC0は積分回路を構成している。このように、1個の
演算増幅器35を中心にして負帰還回路を構成し、PI
D制御を得ている。
As shown in the figure, the AND gate 2B has a recording gate signal (W
-GATE) and a clock signal are applied, and the output thereof is applied to an AND gate 31. In addition, the other input terminal of the AND gate 31 is connected to J via the inverter 30.
[A command (a signal to timely adjust the light intensity of the laser diode) is given. Therefore, during playback, the output of the amplifier 3 is input to the PID circuit via the switch 32, and during recording, the recording gate signal is at a high level (hereinafter referred to as °
A clock signal is output from the AND gate 31 only when the adjustment command (ADJ-IN) is at a low level (hereinafter referred to as "L"), and the ADJ-IN loop and ! r (ADJ-IN is H°), PID is not controlled. Further, the output of the AND game 31 is applied to an analog switch 32 and an analog switch 34 via an inverter 33. Resistors r,, r2 and differential capacitor C1 constitute a differential circuit, and resistor r3
An integrating capacitor C0 connected in parallel to the A/A switch 34 constitutes an integrating circuit. In this way, a negative feedback circuit is constructed around one operational amplifier 35, and the PI
D control is obtained.

次に動作を説明する。比較回路3の出力信号は、ウィン
ドコンパレータ、アップダウンカウンタ等により構成さ
れるデジタル制御回路に入力するとともにアナログスイ
ッチ32を介してPID制御回路を構成する差動増幅器
35に入力する。アナログスイッチ34はW−GATE
信号、クロック信号を受けて、前記積分制御を所望に制
御する。PTD制御出力信号は、前記デジタル制御回路
の出力信号を受けるD−Aコンバータ 8と重畳されツ
ェナーダイオードa6を介して光源のドライバを制御す
る作用をなす。従って1本実施例によれば、デジタル制
御と併わせ、誤差信号をPID制御をしてリアルタイム
な光源の光出力安定化を行うことができるものである。
Next, the operation will be explained. The output signal of the comparison circuit 3 is input to a digital control circuit composed of a window comparator, an up/down counter, etc., and is also input via an analog switch 32 to a differential amplifier 35 constituting a PID control circuit. Analog switch 34 is W-GATE
The integral control is controlled as desired by receiving the signal and the clock signal. The PTD control output signal is superimposed on the DA converter 8 which receives the output signal of the digital control circuit, and functions to control the light source driver via the Zener diode a6. Therefore, according to this embodiment, the optical output of the light source can be stabilized in real time by performing PID control on the error signal in addition to digital control.

本発明によれば、特に、光学的情報記録再生装置におい
て情報を記録媒体に記録する際に、従来技術にはないリ
アルタイムでの光出力安定化制御を行う作用をなすもの
で、以下のごとく、再生時のみならず、記録時に極めて
大きな効果を発揮するものである。
According to the present invention, in particular, when recording information on a recording medium in an optical information recording/reproducing device, real-time optical output stabilization control, which is not available in the prior art, is performed, as described below. This is extremely effective not only during playback but also during recording.

]    の   ′    − 上記の如く本発明では、レーザ光源の発光光量に応じた
電気信号を所定の基準レベルと比較することにより誤差
信号を得て、この誤差信号が所定の範囲内で安定するよ
うにレーザ光源の発光光量を制御する光出力安定化装置
において、誤差信号をPID制御するためPID制御手
段を設けたので、リアルタイムで光出力の安定化を図る
ことのできる光出力安定化装置を得ることができる。特
にPID制御は、正常偏差を零にするのに有効な比例+
積分制御に微分制御が付加されたものなので、制御量の
変化にすばやく追従することができるようになる。更に
、この効果は、光学的に情報を記録・消去又は再生する
光学的情報記録再生装置において実際に書き込み動作が
行なわれる時に特に顕著である。
] - As described above, in the present invention, an error signal is obtained by comparing an electric signal corresponding to the amount of light emitted from a laser light source with a predetermined reference level, and this error signal is stabilized within a predetermined range. To obtain an optical output stabilizing device for controlling the amount of light emitted from a laser light source, which can stabilize the optical output in real time by providing a PID control means for PID controlling an error signal. I can do it. In particular, PID control is a proportional +
Since differential control is added to integral control, it is possible to quickly follow changes in the control amount. Furthermore, this effect is particularly noticeable when a write operation is actually performed in an optical information recording/reproducing device that optically records, erases, or reproduces information.

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

第1図は本発明の一実施例の概略構成図、第2図は同実
施例を具体化した回路図、第3図は第2図に示すPID
回路の詳細な回路図、第4図は従来の光出力安定化装置
の一例の構成図である。 LD・・・レーザダイオード、 PD・・・フォトダイ
オード、  4・・・ウィンドコンパレータ、  5・
・・ANDゲート回路、  3・・・比較回路、  6
・・・クロック信号発生器、  7・・・U/Dカウン
タ、  8・・・A/Dコンバータ、22・・・制御回
路、 23・・・ドライバ、24・・・PID回路。
Fig. 1 is a schematic configuration diagram of an embodiment of the present invention, Fig. 2 is a circuit diagram embodying the embodiment, and Fig. 3 is a PID shown in Fig. 2.
A detailed circuit diagram of the circuit, FIG. 4, is a configuration diagram of an example of a conventional optical output stabilizing device. LD...Laser diode, PD...Photodiode, 4...Window comparator, 5.
...AND gate circuit, 3...comparison circuit, 6
...Clock signal generator, 7.. U/D counter, 8.. A/D converter, 22.. Control circuit, 23.. Driver, 24.. PID circuit.

Claims (1)

【特許請求の範囲】[Claims] (1)レーザ光源と、このレーザ光源からの光束の一部
を受けて発光光量に応じた電気信号を出力する光検出器
と、この光検出器からの電気信号を所定の基準レベルと
比較して誤差信号を出力する比較手段と、この誤差信号
が所定の範囲内で安定するように前記レーザ光源を制御
するための制御信号を出力する制御手段と、前記誤差信
号をPID制御するためのPID信号を出力するPID
制御手段と、前記制御信号とPID信号にもとづいて前
記レーザ光源を駆動するドライバとを備える光出力安定
装置。
(1) A laser light source, a photodetector that receives part of the luminous flux from this laser light source and outputs an electrical signal according to the amount of emitted light, and compares the electrical signal from this photodetector with a predetermined reference level. a control means for outputting a control signal for controlling the laser light source so that the error signal is stabilized within a predetermined range; and a PID for performing PID control on the error signal. PID that outputs the signal
A light output stabilizing device comprising: a control means; and a driver that drives the laser light source based on the control signal and the PID signal.
JP59246902A 1984-11-20 1984-11-21 Light output stabilizer Expired - Fee Related JPH067612B2 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
JP59246902A JPH067612B2 (en) 1984-11-21 1984-11-21 Light output stabilizer
DE3546645A DE3546645C2 (en) 1984-11-20 1985-11-19
DE3546599A DE3546599C2 (en) 1984-11-20 1985-11-19
DE19853541002 DE3541002A1 (en) 1984-11-20 1985-11-19 OPTICAL INFORMATION RECORDING AND PLAYBACK STORAGE SYSTEM
US07/169,106 US4858219A (en) 1984-11-20 1988-03-09 Optical information recording reproducing memory system with both power control and optical irradiation inhibiting circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59246902A JPH067612B2 (en) 1984-11-21 1984-11-21 Light output stabilizer

Publications (2)

Publication Number Publication Date
JPS61125098A true JPS61125098A (en) 1986-06-12
JPH067612B2 JPH067612B2 (en) 1994-01-26

Family

ID=17155442

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59246902A Expired - Fee Related JPH067612B2 (en) 1984-11-20 1984-11-21 Light output stabilizer

Country Status (1)

Country Link
JP (1) JPH067612B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009038081A (en) * 2007-07-31 2009-02-19 Nippon Avionics Co Ltd Semiconductor laser drive circuit and laser welding power supply
JP2014154835A (en) * 2013-02-13 2014-08-25 Nippon Telegr & Teleph Corp <Ntt> Optical transmitter
JP2014165392A (en) * 2013-02-26 2014-09-08 Nippon Telegr & Teleph Corp <Ntt> Optical transmitter, and control method thereof

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009038081A (en) * 2007-07-31 2009-02-19 Nippon Avionics Co Ltd Semiconductor laser drive circuit and laser welding power supply
JP2014154835A (en) * 2013-02-13 2014-08-25 Nippon Telegr & Teleph Corp <Ntt> Optical transmitter
JP2014165392A (en) * 2013-02-26 2014-09-08 Nippon Telegr & Teleph Corp <Ntt> Optical transmitter, and control method thereof

Also Published As

Publication number Publication date
JPH067612B2 (en) 1994-01-26

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