JPH067612B2 - Light output stabilizer - Google Patents
Light output stabilizerInfo
- Publication number
- JPH067612B2 JPH067612B2 JP59246902A JP24690284A JPH067612B2 JP H067612 B2 JPH067612 B2 JP H067612B2 JP 59246902 A JP59246902 A JP 59246902A JP 24690284 A JP24690284 A JP 24690284A JP H067612 B2 JPH067612 B2 JP H067612B2
- Authority
- JP
- Japan
- Prior art keywords
- signal
- pid
- control
- output
- 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.)
- Expired - Fee Related
Links
- 239000003381 stabilizer Substances 0.000 title 1
- 230000000087 stabilizing effect Effects 0.000 description 11
- 230000003287 optical effect Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 8
- 230000004907 flux Effects 0.000 description 4
- 239000004065 semiconductor Substances 0.000 description 3
- 239000003990 capacitor Substances 0.000 description 2
- 230000010354 integration Effects 0.000 description 1
Classifications
-
- 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
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B19/00—Driving, 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
- G11B19/02—Control of operating function, e.g. switching from recording to reproducing
- G11B19/04—Arrangements for preventing, inhibiting, or warning against double recording on the same blank or against other recording or reproducing malfunctions
-
- 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
- G11B7/002—Recording, reproducing or erasing systems characterised by the shape or form of the carrier
- G11B7/0037—Recording, reproducing or erasing systems characterised by the shape or form of the carrier with discs
-
- 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
- G11B7/085—Disposition 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
- G11B7/08547—Arrangements for positioning the light beam only without moving the head, e.g. using static electro-optical elements
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Semiconductor Lasers (AREA)
Description
【発明の詳細な説明】 発明の技術分野 本発明は半導体レーザ等のレーザ光源の出力光量を、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。Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an optical output stabilizing device for automatically controlling the output light amount of a laser light source such as a semiconductor laser to a desired level to obtain a stable optical output. .
従来技術と問題点 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。2. Related Art and Problems Semiconductor lasers show a nonlinear optical output characteristic with respect to a driving current (voltage). In order to obtain stable light output from such a laser light source, it is necessary to control the drive current (voltage) optimally. Hereinafter, the present invention and the related art will be described by taking a semiconductor laser as an example, but the same components are denoted by the same reference numerals in the drawings and the description thereof will be omitted.
第４図は従来の光出力安定化装置（ＡＰＣ）の一例の構
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22に与えられる。FIG. 4 is a block diagram of an example of a conventional optical output stabilizing device (APC). A part of the light flux generated from the laser diode LD (light flux emitted from the back surface of the LD) is detected by the photodiode PD and given to the comparison circuit 3. Further, the reference voltage Vref is applied to the comparison circuit 3 from a reference voltage generation circuit (not shown), and the signal (error signal) of the comparison result is applied 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 for controlling the laser diode LD so that the error signal is stable within a predetermined range, and 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（光センサ）ＰＤ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）ＬＤの
発光光量を制御している。従って、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 described above, conventionally, a part of the light flux from the laser diode LD is received by the photodiode (optical sensor) PD,
The amount of light emitted from the laser diode (laser light source) LD is controlled by closed loop control from the comparison circuit 23 to the control circuit and the driver 23. Therefore, the amount of emitted light is controlled only once for the signal to go through the closed loop, and there is a problem that the real-time property is lacking.
発明の目的 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。SUMMARY OF THE INVENTION The present invention has been made to overcome the above-mentioned drawbacks of the prior art, and an object of the present invention is to provide a light output stabilizing device capable of stabilizing light output in real time.
発明の概要 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ＰＩＤ（Proportion
al Integral and Derivative）制御するため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。SUMMARY OF THE INVENTION 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 this error signal is stable within a predetermined range. In the optical output stabilizing device that controls the amount of light emitted from the laser light source, the error signal is transmitted to the PID (Proportion
The present invention provides a light output stabilizing device characterized by being provided with a PID control means for performing al Integral and Derivative) control.
実施例 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、制御
回路22から出力された制御信号からＰＩＤ信号を減じる
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は制御信号から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。Embodiment FIG. 1 is a schematic configuration 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 in parallel with the control circuit 22 on the output side of the comparison circuit 3 and subtraction is performed to subtract the PID signal from the control signal output from the control circuit 22. The point is that the container 25 is provided. With the above-described configuration, the driver 23 drives the laser diode LD based on the signal obtained by subtracting the PID signal from the control signal.
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に与えられ、あらかじめ設定
された上下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２２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の出力はＤ−Ａコンバータ８でアナロ
グ信号に変換され、減算器25に入力される。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。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信号を減じ
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）−（ＰＩ
Ｄ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。FIG. 2 is a circuit diagram embodying the embodiment shown in FIG. A part of the output light of the laser diode LD (especially the light flux emitted from the back surface) is detected by the photodiode PD,
The photodetection signal is amplified by the amplifier 3 and given to the window comparator 4 which constitutes the control circuit 22, and is compared with preset upper and lower limit levels. The AND gate circuit 5 is supplied with the respective output signals of the 22 comparators forming the window comparator 4 and the clock signal from the clock signal generator 6, and the logical operation output thereof is an up / down counter (U / D counter) 7
Input to the up and down terminals of. And
The output of the U / D counter 7 is converted into an analog signal by the DA converter 8 and input to the subtractor 25. On the other hand, the output of the amplifier 3 is given to the PID circuit 24, and the PID circuit 24 outputs the PID signal based on this. Therefore, a signal obtained by subtracting the PID signal from the control signal output from the AD converter 8 is applied to the operational amplifier 10 having the feedback resistor 11, so that the transistor 13 that drives the laser diode LD is [(control Signal)-(PI
D signal)]. The operational amplifier 10, the resistor 12 and the transistor 13 constitute the driver 23 shown 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。
図示の如く、ＡＮＤゲート26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を介して調整命令
（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。本実施例においては、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、再生時のみならず、記録時にきわめて
大きな効果を発揮する。再生時には記録ゲート信号（Ｗ
・ＧＡＴＥ）がローレベル（以下、“Ｌ”という）とな
るのでＡＮＤゲート31の出力はＬとなる。そのため、ス
イッチ32が閉じて増幅器３の出力はＰＩＤ回路に入力さ
れる、また、このときにスイッチ34は開き、ＰＩＤ制御
がなされる。FIG. 3 is a detailed circuit diagram of the PID circuit shown in FIG. 2 in an embodiment in which the present invention is used in an optical information recording / reproducing apparatus.
As shown, the AND gate 26 has a recording gate signal (W.
GATE) and a clock signal, and its output is given to the AND gate 31. Also, AND gate 31
An adjustment command (a signal for executing the adjustment of the light quantity of the laser diode at a proper time) is given to the other input terminal of the through the inverter 30. In this embodiment, the optical output stabilizing control is performed in real time, which is not available in the prior art, and is extremely effective not only during reproduction but also during recording. Recording gate signal (W
Since GATE becomes low level (hereinafter, referred to as "L"), the output of the AND gate 31 becomes L. Therefore, the switch 32 is closed and the output of the amplifier 3 is input to the PID circuit. At this time, the switch 34 is opened and PID control is performed.
一方、記録時には記録ゲート信号（Ｗ・ＧＡＴＥ）がハ
イレベル（以下、“Ｈ”という）となるので、ＡＤＪ・
ＩＮ信号がＬとなり調整命令が与えられていない場合に
クロック信号がＨとなると、ＡＮＤゲート31からはＨの
出力が出力して、スイッチ32を開きスイッチ34を閉じ
る。従って、このときスイッチ32を介して増幅器３の出
力はＰＩＤ回路に入り、ＰＩＤ制御がなされることにな
る。抵抗ｒ１、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とアナログスイッチ34に並列接
続された積分コンデンサｃ２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を中心に負帰還回
路を構成し、ＰＩＤ制御を得ている。On the other hand, at the time of recording, the recording gate signal (W.GATE) becomes a high level (hereinafter referred to as "H").
When the IN signal becomes L and the clock signal becomes H when the adjustment command is not given, the AND gate 31 outputs an H output to open the switch 32 and close the switch 34. Therefore, at this time, the output of the amplifier 3 enters the PID circuit via the switch 32 and PID control is performed. The resistors r 1 and r 2 and the differential capacitor c 1 form a differentiating circuit, and the resistor r 3 and the integrating capacitor c 2 connected in parallel to the analog switch 34 form an integrating circuit. In this way, a negative feedback circuit is constructed around one operational amplifier 35 to obtain PID control.
次に動作を説明する。比較回路３の出力信号は、ウイン
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。ＰＩＤ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の出力と重畳され
ツェナーダイオード36を介して光源のドライバを制御す
る作用をなす。従って、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 described. The output signal of the comparison circuit 3 is input to a digital control circuit including a window comparator, an up / down counter, etc., and a differential amplifier forming a PID control circuit via the analog switch 32.
Enter in 35. The analog switch 34 receives the W.GATE signal and the clock signal and controls the integration control as desired. The PID control output signal is superimposed on the output of the D / A converter 8 which receives the output signal of the digital control circuit, and serves to control the driver of the light source through the Zener diode 36. Therefore, according to this embodiment, it is possible to stabilize the optical output of the light source in real time by performing PID control of the error signal in combination with digital control.
発明の効果 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。As described above, in the present invention, an error signal is obtained by comparing an electric signal corresponding to the emitted light amount of the laser light source with a predetermined reference level, and the error signal is stabilized within a predetermined range. In the light output stabilizing device for controlling the amount of light emitted from the light source, since the PID control means is provided for PID controlling the error signal, it is possible to obtain the light output stabilizing device capable of stabilizing the light output in real time. it can. In particular, PID control is effective proportional to zero normal deviation +
Since the derivative control is added to the integral control, it is possible to quickly follow the change in the control amount.
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 same embodiment, and FIG. 3 is a PID shown in FIG.
FIG. 4 is a detailed circuit diagram of the circuit, and is a configuration diagram of an example of a conventional optical output stabilizing device. LD ... Laser diode, PD ... Photo diode, 4
… Window comparator, 5… AND gate circuit, 3…
Comparing circuit, 6 ... Clock signal generator, 7 ... U / D counter, 8 ... A / D converter, 22 ... Control circuit, 23 ... Driver, 24 ... PID circuit.
Claims (1)
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 a part of a light beam from the laser light source and outputs an electric signal according to the amount of emitted light, and an electric signal from the photodetector is set to a predetermined reference level. Comparing means for comparing and outputting an error signal, control means for outputting a control signal for controlling the laser light source so that the error signal is stable within a predetermined range, and PID control for the error signal A PID control means for outputting the PID signal of 1., and a driver for driving the laser light source based on the control signal and the PID signal.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59246902A JPH067612B2 (en) | 1984-11-21 | 1984-11-21 | Light output stabilizer |
| DE3546599A DE3546599C2 (en) | 1984-11-20 | 1985-11-19 | |
| DE3546645A DE3546645C2 (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 JPS61125098A (en) | 1986-06-12 |
| JPH067612B2 true 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) |
Families Citing this family (3)
| 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 source |
| 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 |
-
1984
- 1984-11-21 JP JP59246902A patent/JPH067612B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61125098A (en) | 1986-06-12 |
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