JPH02246027A - Semiconductor laser driving circuit - Google Patents
Semiconductor laser driving circuitInfo
- Publication number
- JPH02246027A JPH02246027A JP1067073A JP6707389A JPH02246027A JP H02246027 A JPH02246027 A JP H02246027A JP 1067073 A JP1067073 A JP 1067073A JP 6707389 A JP6707389 A JP 6707389A JP H02246027 A JPH02246027 A JP H02246027A
- Authority
- JP
- Japan
- Prior art keywords
- current
- voltage
- semiconductor laser
- monitor
- optical output
- 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
Links
- 239000004065 semiconductor Substances 0.000 title claims abstract description 41
- 230000003287 optical effect Effects 0.000 claims abstract description 45
- 238000006243 chemical reaction Methods 0.000 claims abstract description 13
- 230000035945 sensitivity Effects 0.000 abstract description 24
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 1
Landscapes
- Optical Head (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は光学的に記録・消去・再生できる光ディスクに
情報を記録あるいは消去し、この光ディスクから記録し
た情報を再生する記録・消去可能な光デイスク装置に用
いる半導体レーザ駆動回路に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a recordable/erasable optical disk device that records or erases information on an optical disk that can be optically recorded, erased, and reproduced, and that reproduces recorded information from this optical disk. The present invention relates to a semiconductor laser drive circuit used for.
従来の技術 第３図に従来の半導体レーザ駆動回路の構成図を示す。Conventional technology FIG. 3 shows a configuration diagram of a conventional semiconductor laser drive circuit.
構成は大きく分けると上半分の再生・消去系と下半分の
記録系になる。まず再生・消去系から説明する。半導体
レーザ１の光出力を光検出器２で受光し、光検出器２の
モニター電流１．を抵抗４と電流電圧変換器３がモニタ
ー電圧ｖＭに変換する。電流電圧変換効率は抵抗４の大
きさで決まる。以降電流電圧変換効率は、抵抗４の大き
さで表すものとする。モニター電圧■２と光出力の再生
を決める基準電圧ｖＰ Ｌ ＋ あるいは消去の基準電
圧ｖｍｓとの比較をサーボアンプ１の５が行い。The configuration can be roughly divided into the upper half of the playback/erasing system and the lower half of the recording system. First, we will explain the reproduction/erasing system. The optical output of the semiconductor laser 1 is received by the photodetector 2, and the monitor current of the photodetector 2 is 1. The resistor 4 and current-voltage converter 3 convert it into a monitor voltage vM. The current-voltage conversion efficiency is determined by the size of the resistor 4. Hereinafter, the current-voltage conversion efficiency will be expressed by the size of the resistor 4. The servo amplifier 5 of the servo amplifier 1 compares the monitor voltage 2 with the reference voltage vP L + for determining the reproduction of the optical output or the reference voltage vms for erasing.
その出力を１０のＳ／Ｉ（１がサンプルホールドする。The output is S/I of 10 (1 samples and holds it.
基準電圧Ｖｐｔ、Ｖｓｓは６，７１７）スイッチＳＷ１
゜ＳＷ２の制御で選択される。１０のＳ／Ｈ１は電流源
１の１１につながり、半導体レーザ１に流す電流を制御
する。Reference voltage Vpt, Vss is 6,717) Switch SW1
゜Selected by SW2 control. S/H 1 of 10 is connected to 11 of current source 1 and controls the current flowing through semiconductor laser 1 .
記録系は記録の光出力を決める基準電圧Ｖｒｄ５が記録
の時に１３のスイッチＳＷ３により選択される。記録以
外では１４のスイッチＳＷ４がオンでグランドの電圧ゼ
ロが選択される。１５の基準電圧ＶＦＩＩＦとモニター
電圧ｖＭとの比較をサーボアンプ２の１２が行い、その
出力を１６のＳ／Ｈ２がサンプルホルトする。１６のＳ
／Ｈ２は電流源２の１７につながり、半導体レーザ１に
流す電流を制御する。電流源」と２でホールドした電流
の間で記録データ１９を１８の変調段が変調を行なう。In the recording system, a reference voltage Vrd5 that determines the optical output for recording is selected by 13 switches SW3 during recording. At times other than recording, the 14 switches SW4 are turned on and the ground voltage of zero is selected. The servo amplifier 2 12 compares the 15 reference voltage VFIIF with the monitor voltage vM, and the 16 S/H 2 samples and holds the output. 16 S
/H2 is connected to 17 of the current source 2 and controls the current flowing through the semiconductor laser 1. Eighteen modulation stages modulate the recording data 19 between the current held by the current source and the current held by the current source 2.
以上のように構成された従来の半導体レーザ駆動回路の
光出力を第４図（ａ）に示す、再生サーボ区間で前記再
生・消去系がサーボ系として動作する。The optical output of the conventional semiconductor laser drive circuit configured as described above is shown in FIG. 4(a). In the reproduction servo section, the reproduction/erase system operates as a servo system.
消去サーボ区間では、再生・消去系の基準電圧が再生の
ＶＰＬから消去のＶ□になり、光出力が再生から消去に
立ち上がると、前記１０のＳ／Ｈ１がホールド動作にな
り電流源１の消去電流がホールドされる０次に記録サー
ボ区間で記録系の基準電圧がゼロから記録のＶＦＩＩに
なり光出力が記録パワーに立ち上がる。すると前記１６
のＳ／Ｈ２がホールド動作になり電流源２の記録電流が
ホールドされる。記録ホールド区間では、ホールドされ
た２つの電流の間で記録データの変調が行なわれる。In the erase servo period, the reference voltage of the reproduction/erase system changes from VPL for reproduction to V□ for erase, and when the optical output rises from reproduction to erase, the 10 S/H1 goes into hold operation and the current source 1 erases. In the 0th order recording servo period in which the current is held, the reference voltage of the recording system changes from zero to VFII for recording, and the optical output rises to the recording power. Then, the above 16
S/H2 enters a hold operation and the recording current of current source 2 is held. In the recording hold period, recording data is modulated between the two held currents.
具体的な例として、第４図（ａ）のように光出力を再生
１ ｍ Ｗ ＋消去１０ ｍ Ｗ ＋記録２０ｍＷに設
定する場合を考える。半導体レーザの光検出器のモニタ
ー電流１．は、第４図（ｂ）のように光出力１ｍＷ当り
１ｍＡ発生するとする。これを光検出器のモニター電流
の感度と呼び、以降１ｍＡ／ｍＷと表わす。As a specific example, consider a case where the optical output is set to 1 mW for reproduction + 10 mW for erasure + 20 mW for recording as shown in FIG. 4(a). Monitor current of semiconductor laser photodetector 1. Assume that 1 mA is generated per 1 mW of optical output as shown in FIG. 4(b). This is called the sensitivity of the monitor current of the photodetector, and is hereinafter expressed as 1 mA/mW.
この時前記電流電圧変換器３の抵抗４がＩＫΩとすると
、モニター電圧■２はモニター電流ｒ工に抵抗ＩＫΩを
かけて、第４図（Ｃ）のようになる。At this time, assuming that the resistance 4 of the current-voltage converter 3 is IKΩ, the monitor voltage 2 is obtained by multiplying the monitor current r by the resistance IKΩ as shown in FIG. 4(C).
つまり、再生で１ボルト、消去で１０ボルト、記録で２
０ボルトのモニター電圧Ｖ、が得られる。That is, 1 volt for playback, 10 volts for erase, and 2 volts for recording.
A monitor voltage V of 0 volts is obtained.
これが回路内での光出力を設定するための基準電圧Ｖ□
、Ｖ、、、Ｖ□としてそれぞれ設定される。This is the reference voltage V□ for setting the optical output in the circuit.
, V, , V□, respectively.
発明が解決しようとする課題
しかしながら上記のような構成では、光検出器のモニタ
ー電流の感度が異なる半導体レーザを接続した場合に、
設定される光出力が変化するため、３つの基準電圧を再
度設定しなければいけないという問題点を有していた。Problems to be Solved by the Invention However, in the above configuration, when semiconductor lasers with different sensitivities of the monitor current of the photodetector are connected,
Since the set optical output changes, there is a problem in that the three reference voltages have to be set again.
例えば、従来例で半導体レーザが変わって、光検出器の
モニター電流の感度が１ｍＡ／ｍＷから、０．５ｍＡ／
ｍＷと半分になったとする。基準電圧と電流電圧変換器
３の抵抗４が同じであるなら、再生時には基準電圧が１
ボルトのためモニター電流は１ｍＡになるようサーボが
かかる。光検出器のモニター電流１ｍＡでは、感度０．
５ｍＡ／ｍＷから換算すると光出力が２ｍＷ出ることに
なり、感度が１ｍＡ／ｍＷの半導体レーザの光出力の時
の１ｍＷに比べると２倍の光出力になる。こは再生以外
の消去、記録についても同じで従来の光出力の２倍、つ
まり消去が２０ｍＷ、記録が４０ｍＷになる。この様子
を第４図（ｄ）に示す。For example, when the semiconductor laser was changed from the conventional example, the sensitivity of the photodetector's monitor current changed from 1mA/mW to 0.5mA/mW.
Suppose it is halved to mW. If the reference voltage and the resistance 4 of the current-voltage converter 3 are the same, the reference voltage will be 1 during playback.
Since it is a volt, a servo is applied so that the monitor current is 1mA. At a photodetector monitor current of 1 mA, the sensitivity is 0.
When converted from 5 mA/mW, the optical output is 2 mW, which is twice the optical output of 1 mW when a semiconductor laser with a sensitivity of 1 mA/mW has an optical output. This also applies to erasing and recording other than reproduction, which is twice the conventional optical output, that is, 20 mW for erasing and 40 mW for recording. This situation is shown in FIG. 4(d).
つまり、基準電圧と電流電圧変換器の抵抗が一定で、光
検出器の光出力に対するモニター電流の感度が半分の半
導体レーザになると、設定される光出力が２倍になり、
光検出器の光出力に対するモニター電流の感度が２倍の
半導体レーザでは、設定される光出力が２分の１になる
。In other words, if the reference voltage and the resistance of the current-voltage converter are constant, and the sensitivity of the monitor current to the optical output of the photodetector is half that of a semiconductor laser, the set optical output will double,
In a semiconductor laser in which the monitor current has twice the sensitivity to the optical output of the photodetector, the set optical output will be halved.
このため半導体レーザ毎に異なる光検出器のモニター電
流の感度の違いによる光出力の変化を吸収して同じ光出
力にするため、再生、消去、記録の基準電圧を設定し直
す必要がある。これは半導体レーザを接続する毎に、３
つの基準電圧を調整するため、調整箇所が多く半導体レ
ーザ駆動回路の信頼性が低下するという問題点を有して
いた。Therefore, it is necessary to reset the reference voltages for reproduction, erasure, and recording in order to absorb changes in the optical output due to differences in the sensitivity of the monitor current of the photodetector for each semiconductor laser and maintain the same optical output. This means that each time a semiconductor laser is connected, 3
Since two reference voltages are adjusted, there is a problem in that there are many adjustment points and the reliability of the semiconductor laser drive circuit is reduced.
本発明はかかる点に鑑み、電流電圧変換器の電流電圧変
換効率を可変として光検出器のモニター電流の感度の違
いを吸収して、再生、消去、記録の３つの基準電圧の調
整をなくし信頼性の高い半導体レーザ駆動回路を提供す
ることを目的とする。In view of this, the present invention makes the current-voltage conversion efficiency of the current-voltage converter variable to absorb the difference in sensitivity of the monitor current of the photodetector, thereby eliminating the need for adjusting the three reference voltages for reproduction, erasing, and recording, thereby providing reliability. The purpose of the present invention is to provide a semiconductor laser drive circuit with high performance.
課題を解決するための手段
本発明は半導体レーザの光出力を受光し光出力に応じた
モニター電流を発生する光検出器と、モニター電流をモ
ニター電圧に変換する電流電圧変換器と、設定光出力を
決めるための基準電圧発生手段と、モニター電流の感度
が異なる光検出器を用いて基準電圧に対する設定光出力
が同じになるよう前記電流電圧変換器の電流電圧変換効
率を可変とする手段とを備えた半導体レーザ駆動回路で
ある。Means for Solving the Problems The present invention includes a photodetector that receives the optical output of a semiconductor laser and generates a monitor current according to the optical output, a current-voltage converter that converts the monitor current into a monitor voltage, and a set optical output. and means for varying the current-voltage conversion efficiency of the current-voltage converter so that the set optical output with respect to the reference voltage is the same using photodetectors with different sensitivities of monitor currents. This is a semiconductor laser drive circuit equipped with a semiconductor laser drive circuit.
作用
本発明は前記した構成により、光検出器のモニター電流
の感度が異なる半導体レーザに対して、電流電圧変換器
の変換効率を可変にすることで感度差を吸収して、設定
光出力を同一にし、再生。According to the above-described configuration, the present invention absorbs the difference in sensitivity by making the conversion efficiency of the current-voltage converter variable for semiconductor lasers with different sensitivities of the monitor current of the photodetector, so that the set optical output can be kept the same. and play.
消去、記録の３つの基準電圧の調整をなくし、半導体レ
ーザ駆動回路の信親性を向上した。The reliability of the semiconductor laser drive circuit is improved by eliminating the need to adjust the three reference voltages for erasing and recording.
実施例
第１図は本発明の一実施例における半導体レーザ駆動回
路の構成を示す。Embodiment FIG. 1 shows the configuration of a semiconductor laser drive circuit in an embodiment of the present invention.
第１図において先に説明した第３図の従来例に追加変更
した部分の説明を行なう、２０は電流電圧変換器３の抵
抗を可変にして電流電圧変換効率を変えるようにした。In FIG. 1, additional changes to the conventional example shown in FIG. 3 described above will be explained. Reference numeral 20 makes the resistance of the current-voltage converter 3 variable to change the current-voltage conversion efficiency.
基準電圧は調整する必要がないため、電圧の可変部をな
くした。Since there is no need to adjust the reference voltage, the variable voltage section has been eliminated.
以上のように構成された半導体レーザ駆動回路の動作を
第２図で説明する。先の従来例と同じように、光出力を
再生１ｍＷ、消去１０ｍＷ、記録２０ｍＷに設定する場
合を考える。半導体レーザの光検出器のモニターｉｉｒ
、の感度を先の従来例と同じ＜１ｍＡ／ｍＷと０．５ｍ
Ａ／ｍＷの２種とする。光出力を設定する基準電圧は、
再生１ボルト、消去１０ボルト、記録２０ポルトで一定
である。The operation of the semiconductor laser drive circuit configured as described above will be explained with reference to FIG. As in the previous conventional example, consider the case where the optical output is set to 1 mW for reproduction, 10 mW for erasing, and 20 mW for recording. Semiconductor laser photodetector monitor IIR
, the sensitivity of <1mA/mW and 0.5m is the same as the previous conventional example.
There are two types: A/mW. The reference voltage that sets the optical output is
It is constant at 1 volt for reproduction, 10 volts for erasure, and 20 volts for recording.
最初にモニター電流■２の感度が１ｍＡ／ｍＷの半導体
レーザの時には、電流電圧変換器３の可変抵抗２０の値
はＩＫΩに設定され、先の第４図（ハ）のモニター電流
１．と第４図（Ｃ）のモニター電圧■いが得られ、光出
力が再生１ｍｗ、消去１０ｍＷ。Initially, when the semiconductor laser has a sensitivity of the monitor current 2 of 1 mA/mW, the value of the variable resistor 20 of the current-voltage converter 3 is set to IKΩ, and the monitor current 1.2 shown in FIG. The monitor voltage shown in Figure 4 (C) was obtained, and the optical output was 1 mW for reproduction and 10 mW for erasure.
記録２０ｍＷに第４図（ａ）のように設定される。The recording power is set to 20 mW as shown in FIG. 4(a).
次に光検出器のモニター電流の感度が、０．５ｍ Ａ
／ ｍ Ｗの半導体レーザの場合を第２図に示す。Next, the sensitivity of the monitor current of the photodetector is 0.5mA
/mW semiconductor laser is shown in FIG.
モニター電流の感度差を吸収して、光出力を設定する基
準電圧と等しいモニター電圧■２になるように、電流電
圧変換器３の可変抵抗の値を２にΩに設定する。すると
再生時のモニター電圧ｌボルトを可変抵抗２にΩでわる
と、モニター電流１゜が第２回部）のように０．５ｍＡ
になる。光検出器のモニター電流が０．５ｍＡだと、モ
ニター電流の感度から光出力が１ｍＷ出ることになる。The value of the variable resistor of the current-voltage converter 3 is set to 2 Ω so that the sensitivity difference in the monitor current is absorbed and the monitor voltage becomes 2 which is equal to the reference voltage for setting the optical output. Then, when the monitor voltage 1 volt during playback is divided by the variable resistor 2 by Ω, the monitor current 1° is 0.5 mA as shown in Part 2).
become. If the monitor current of the photodetector is 0.5 mA, the optical output will be 1 mW due to the sensitivity of the monitor current.
再生と同様、消去、記録の光出力もそれぞれ１０ｍＷ。As well as playback, the optical output for erasing and recording is 10mW each.
２０ｍＷに設定される。It is set to 20mW.
以上のように本実施例によれば、電流電圧変換器の抵抗
を可変にすることにより、半導体レーザ毎に異なる光検
出器のモニター電流の感度差を吸収でき、光出力を設定
する基準電圧の再生、消去。As described above, according to this embodiment, by making the resistance of the current-voltage converter variable, it is possible to absorb the difference in sensitivity of the monitor current of the photodetector, which differs for each semiconductor laser, and to adjust the reference voltage for setting the optical output. Play, erase.
記録の調整をなくし、半導体レーザ駆動回路の信輔性を
向上させることができる。Recording adjustment can be eliminated and reliability of the semiconductor laser drive circuit can be improved.
なお、本実施例において電流電圧変換器のフィードバッ
ク抵抗を可変抵抗として光検出器の感度差を吸収したが
、これはフィードバック抵抗を固定にし電流電圧変換器
の出力を可変とする事で光検出器の感度差を吸収しても
よい。Note that in this example, the feedback resistance of the current-voltage converter was used as a variable resistor to absorb the difference in sensitivity of the photodetector. may absorb the difference in sensitivity.
また、電流電圧変換器の電流電圧変換効率を可変にする
手段は、抵抗を可変にしたが、電流電圧の変換効率が変
わるものであれば何でもよい。Further, although the resistance is used as a variable means for making the current-voltage conversion efficiency of the current-voltage converter variable, any means that changes the current-voltage conversion efficiency may be used.
また、本実施例では光出力を再生、消去、記録。In addition, in this embodiment, optical output can be reproduced, erased, and recorded.
の３つに設定したが、再生、記録の２つあるいは、再生
と３つ以上の光出力の設定についても、同様に適用でき
るのは言うまでもない。It goes without saying that the settings can be similarly applied to settings for two optical outputs, playback and recording, or for playback and three or more optical outputs.
発明の詳細
な説明したように、本発明によれば、電流電圧変換器の
電流電圧変換効率を可変にすることにより、半導体レー
ザ毎に異なる光検出器のモニター電流の感度差を吸収で
き、光出力を設定する基準電圧の再生、消去、記録の調
整をなくし、半導体レーザ駆動回路の信幀性を向上させ
ることができ、その実用的効果は大きい。As described in detail, according to the present invention, by making the current-voltage conversion efficiency of the current-voltage converter variable, it is possible to absorb the difference in sensitivity of the monitor current of the photodetector, which differs for each semiconductor laser, and to The reliability of the semiconductor laser drive circuit can be improved by eliminating the need to adjust the reference voltage for setting the output for reproducing, erasing, and recording, and the practical effect is great.
第１図は本発明の実施例の半導体レーザ駆動回路の構成
図、第２図は同実施例の動作波形図、第３図は従来の半
導体レーザ駆動回路の構成図、第４図は同従来例の動作
波形図である。
ｌ・・・・・・半導体レーザ、２・・・・−・光検出器
、３・・・・・・電流電圧変換器、５・・・・・・サー
ボアンプ１．１０・・・・・・サンプルホールド１．１
１・・・・・・電流源ｌ、１２・・・・・・サーボアン
プ２．１６・・・・・・サンプルホールド２．１７・・
・・・・電流源２．１８・・・・・・変調段、２０・・
・・・・可変抵抗。
代理人の氏名 弁理士 粟野重孝 はか１名第
図Fig. 1 is a block diagram of a semiconductor laser drive circuit according to an embodiment of the present invention, Fig. 2 is an operation waveform diagram of the same embodiment, Fig. 3 is a block diagram of a conventional semiconductor laser drive circuit, and Fig. 4 is a block diagram of the conventional semiconductor laser drive circuit. FIG. 3 is an example operational waveform diagram. l...Semiconductor laser, 2...--Photodetector, 3...Current-voltage converter, 5...Servo amplifier 1.10...・Sample hold 1.1
1...Current source l, 12...Servo amplifier 2.16...Sample hold 2.17...
...Current source 2.18 ...Modulation stage, 20...
...Variable resistance. Name of agent: Patent attorney Shigetaka Awano
Claims (1)
電流を発生する光検出器と、前記モニター電流をモニタ
ー電圧に変換する電流電圧変換器と、設定光出力を決め
るための基準電圧発生手段と、前記基準電圧と前記モニ
ター電圧とを比較して制御電圧を発生するサーボアンプ
と、前記制御電圧により半導体レーザに流す電流を制御
する電流源と、同一光出力に対する前記モニター電流の
大きさが異なる光検出器を用いて前記基準電圧に対する
設定光出力が同じになるよう、前記電流電圧変換器の電
流電圧変換効率を可変とする手段とを備えた半導体レー
ザ駆動回路。a photodetector that receives the optical output of a semiconductor laser and generates a monitor current according to the optical output; a current-voltage converter that converts the monitor current into a monitor voltage; and a reference voltage generator for determining a set optical output. , a servo amplifier that generates a control voltage by comparing the reference voltage and the monitor voltage, a current source that controls the current flowing through the semiconductor laser based on the control voltage, and a magnitude of the monitor current for the same optical output is different. A semiconductor laser drive circuit comprising means for varying the current-voltage conversion efficiency of the current-voltage converter using a photodetector so that the set optical output with respect to the reference voltage becomes the same.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1067073A JPH02246027A (en) | 1989-03-17 | 1989-03-17 | Semiconductor laser driving circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1067073A JPH02246027A (en) | 1989-03-17 | 1989-03-17 | Semiconductor laser driving circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02246027A true JPH02246027A (en) | 1990-10-01 |
Family
ID=13334325
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1067073A Pending JPH02246027A (en) | 1989-03-17 | 1989-03-17 | Semiconductor laser driving circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02246027A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03147534A (en) * | 1989-11-02 | 1991-06-24 | Sharp Corp | Optical pickup |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6220385A (en) * | 1985-07-18 | 1987-01-28 | Mita Ind Co Ltd | Optical output adjusting apparatus of semiconductor laser |
| JPH01144243A (en) * | 1987-11-30 | 1989-06-06 | Toshiba Corp | Information recorder |
| JPH0266884A (en) * | 1988-08-31 | 1990-03-06 | Olympus Optical Co Ltd | Control device for luminous energy of light emitting substance |
-
1989
- 1989-03-17 JP JP1067073A patent/JPH02246027A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6220385A (en) * | 1985-07-18 | 1987-01-28 | Mita Ind Co Ltd | Optical output adjusting apparatus of semiconductor laser |
| JPH01144243A (en) * | 1987-11-30 | 1989-06-06 | Toshiba Corp | Information recorder |
| JPH0266884A (en) * | 1988-08-31 | 1990-03-06 | Olympus Optical Co Ltd | Control device for luminous energy of light emitting substance |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03147534A (en) * | 1989-11-02 | 1991-06-24 | Sharp Corp | Optical pickup |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPS6346633A (en) | Recording and reproducing device for optical disk | |
| JPS63103447A (en) | Laser control circuit for optical information recording and reproducing device | |
| JP2706262B2 (en) | Semiconductor laser driver | |
| US6744031B1 (en) | High speed sampling circuit | |
| JP3368908B2 (en) | Magneto-optical disk recording / reproducing device | |
| JPH02246027A (en) | Semiconductor laser driving circuit | |
| JPH07111783B2 (en) | Semiconductor laser control circuit | |
| JPH0626275B2 (en) | Semiconductor laser drive circuit | |
| JPS6233341A (en) | Optical information recording and reproducing device | |
| JP2574303B2 (en) | Semiconductor laser drive circuit | |
| JP4010079B2 (en) | Optical disk device | |
| JP2745747B2 (en) | Optical disk drive | |
| KR0153902B1 (en) | Laser power modulation circuit for data recordable disc | |
| JPH02287930A (en) | Semiconductor laser driving circuit | |
| JP2507051B2 (en) | Optical data storage / reproduction device | |
| JPH04271025A (en) | Apc circuit for laser light source | |
| KR100289718B1 (en) | Optical recording controlling method using high frequency modulation and apparatus therefor | |
| JPH03245327A (en) | Light emission power control circuit for semiconductor laser | |
| JPH0827956B2 (en) | Semiconductor laser drive circuit | |
| JPS63146232A (en) | Servo device for optical disk information recording/ reproducing device | |
| JPH01107335A (en) | Semiconductor laser control circuit | |
| JPH087871B2 (en) | Optical data storage / playback device | |
| JPH0676403A (en) | Semiconductor laser driving circuit | |
| JPH0814893B2 (en) | Optical signal regenerator | |
| JPS63241733A (en) | Semiconductor laser control circuit |