JPS63121141A - Laser driving circuit for optical disk reproducing device - Google Patents
Laser driving circuit for optical disk reproducing deviceInfo
- Publication number
- JPS63121141A JPS63121141A JP61265767A JP26576786A JPS63121141A JP S63121141 A JPS63121141 A JP S63121141A JP 61265767 A JP61265767 A JP 61265767A JP 26576786 A JP26576786 A JP 26576786A JP S63121141 A JPS63121141 A JP S63121141A
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- Prior art keywords
- driving
- laser diode
- drive
- voltage
- laser
- 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.)
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- 238000006243 chemical reaction Methods 0.000 claims description 7
- 238000003079 width control Methods 0.000 abstract description 7
- 238000005457 optimization Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 4
- 238000009499 grossing Methods 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
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- 230000006866 deterioration Effects 0.000 description 1
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- 238000005516 engineering process Methods 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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- Semiconductor Lasers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は、光ディスク再生装置のレーザー駆動回路に
係り、特に、無効電力の削減などに関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a laser drive circuit for an optical disc reproducing device, and particularly relates to reducing reactive power.
光ディスク再生装置は、コンパクトディスク（ＣＤ）な
どの光ディスクに記録された映像や音楽などの各種の信
号を、光ディスクにレーザー光の照射およびその反射を
利用して再生するものであり、レーザーダイオードを駆
動してレーザー光を発生させるためのレーザー駆動回路
が設置されている。An optical disc playback device plays back various signals such as video and music recorded on an optical disc such as a compact disc (CD) by irradiating the optical disc with laser light and its reflection, and drives a laser diode. A laser drive circuit is installed to generate laser light.
このレーザー駆動回路は、第４図に示すように、レーザ
ーダイオード２に対して駆動トランジスタ４を通して駆
動電流を流し、レーザーダイオード２が発生したレーザ
ー光６を図示していない光ディスクに向けて照射すると
ともに、受光ダイオード８で受け、その受光出力を増幅
器１０を通して駆動トランジスタ４のベースに帰還し、
レーザーダイオード２の駆動電流を制御する。As shown in FIG. 4, this laser drive circuit supplies a drive current to a laser diode 2 through a drive transistor 4, and irradiates a laser beam 6 generated by the laser diode 2 toward an optical disk (not shown). , is received by the light receiving diode 8, and the light receiving output is fed back to the base of the driving transistor 4 through the amplifier 10,
Controls the drive current of the laser diode 2.
すなわち、このレーザー駆動回路では、レーザー光６を
一定に保持するため、駆動トランジスタ４のリニアな駆
動状態が得られるように制御している。That is, in this laser drive circuit, in order to maintain the laser light 6 constant, control is performed so that a linear drive state of the drive transistor 4 is obtained.
ところで、光ディスク再生装置では、光ディスクを回転
させるモータなどの機械的な駆動部に５〜１２Ｖの駆動
電圧を必要としているので、このようなレーザー駆動回
路における電源電圧ＶＣＣも５〜１２Ｖの駆動電圧と共
通化した場合、通常、レーザーダイオードの順方向降下
電圧ＶＦは１．８Ｖ程度であるので、■、８ｖを越える
電圧は無効電圧となるとともに、駆動トランジスタ４に
よる消費電力が大きいという欠点がある。By the way, in an optical disc playback device, a mechanical drive unit such as a motor that rotates an optical disc requires a drive voltage of 5 to 12V, so the power supply voltage VCC in such a laser drive circuit also has a drive voltage of 5 to 12V. When the laser diode is shared, the forward voltage drop VF of the laser diode is usually about 1.8V, so a voltage exceeding 8V becomes an invalid voltage, and the power consumption by the drive transistor 4 is large.
そこで、この発明は、電源電圧ＶＣＣの値の変更を伴う
ことなく、無効電圧の削減とともに、駆動トランジスタ
による電力消費の削減により、駆動効率の向上を図った
光ディスク再生装置のレーザー駆動回路の捷供を目的と
する。Therefore, the present invention provides a laser drive circuit for an optical disc playback device that improves drive efficiency by reducing reactive voltage and power consumption by drive transistors without changing the value of power supply voltage VCC. With the goal.
この発明の光ディスク再生装置のレーザー駆動回路は、
第１図に示すように、レーザーダイオード２が発生した
レーザー光６を受光素子（受光ダイオード８）で受け、
その受光出力に応じた駆動制御信号ｖｄｅを出力する駆
動制御手段（パルス幅制御回路１４）と、この駆動制御
手段（パルス幅制御回路１４）が発生した駆動制御信号
■。に応じた駆動電圧■。をレーザーダイオード２に加
えて駆動電流■。を流す直流−直流変換手段（ＤＣ−Ｄ
Ｃコンバータ１２）とを備えたものである。The laser drive circuit of the optical disc playback device of this invention includes:
As shown in FIG. 1, the laser beam 6 generated by the laser diode 2 is received by a light receiving element (light receiving diode 8),
A drive control means (pulse width control circuit 14) that outputs a drive control signal vde according to the received light output, and a drive control signal (2) generated by this drive control means (pulse width control circuit 14). Drive voltage according to ■. In addition to laser diode 2, drive current ■. DC-DC conversion means (DC-D
C converter 12).
この発明の光ディスク再生装置のレーザー駆動回路では
、レーザーダイオード２が発生したレーザー光６を受光
素子（受光ダイオード８）で受光し、その受光出力を駆
動制御手段（パルス幅制御回路１４）によって駆動制御
信号ｖｄｃに変換して直流−直流変換手段（ＤＣ−ＤＣ
コンバータ１２）に加え、駆動制御信号Ｖｄｃに応じて
電源電圧ＶＣＣを直流−直流変換手段（ＤＣ−ＤＣコン
バータ１２）によって得られた駆動電圧■。をレーザー
ダイオード２に加えることにより、駆動電流Ｉ０をレー
ザーダイオード２に流し、レーザーダイオード２の駆動
電圧■、の適正化（無効電圧の削減）とともに、第４図
に示すような駆動トランジスタ４を用いた場合の電力消
費の低減化を図る。In the laser drive circuit of the optical disc playback device of the present invention, the laser beam 6 generated by the laser diode 2 is received by the light receiving element (light receiving diode 8), and the received light output is drive controlled by the drive control means (pulse width control circuit 14). The signal is converted into a DC-DC converter (DC-DC).
In addition to the converter 12), the drive voltage (2) is obtained by converting the power supply voltage VCC into a DC-DC converter (DC-DC converter 12) according to the drive control signal Vdc. By adding 0 to the laser diode 2, a drive current I0 is caused to flow through the laser diode 2, and the drive voltage 2 of the laser diode 2 is optimized (reducing the reactive voltage), and a drive transistor 4 as shown in FIG. 4 is used. The aim is to reduce power consumption when
第１図は、この発明の光ディスク再生装置のレーザー駆
動回路の実施例を示す。FIG. 1 shows an embodiment of a laser drive circuit for an optical disc reproducing apparatus according to the present invention.
ＤＣ−ＤＣコンバータ（ＤＣ／ＤＣ）１２は、電源電圧
ｖｃｅをレーザーダイオード２を駆動するに適正な駆動
電圧Ｖ、に変換する直流−直流変換手段として設置され
、このＤＣ／ＤＣ１２によって得られた駆動電圧Ｖ、を
レーザーダイオード２のアノードに加えてレーザーダイ
オード２に駆動電流■。を流す、ＤＣ／ＤＣ１２は、パ
ルス幅制御回路（ＰＷＭ）１４からの駆動制御信号ｖ４
ｃを以てスイッチング素子を動作させ、そのスイッチン
グによって電源電圧Ｖｃｃを断続して電圧変換の後、整
流して適正な電圧ｖＩｌを得る。A DC-DC converter (DC/DC) 12 is installed as a DC-DC conversion means for converting the power supply voltage Vce into a drive voltage V suitable for driving the laser diode 2, and the drive obtained by this DC/DC 12 is A voltage V is applied to the anode of the laser diode 2, and a driving current ■ is applied to the laser diode 2. The DC/DC 12 is the drive control signal v4 from the pulse width control circuit (PWM) 14.
The switching element is operated by the switching element c, and the power supply voltage Vcc is turned on and off by the switching, and after voltage conversion, rectification is performed to obtain an appropriate voltage vIl.
ＰＷＭ１４は、ＤＣ／ＤＣ１２の駆動制御手段として設
置されたものであり、レーザーダイオード２がＤＣ／Ｄ
Ｃ１２から供給される駆動電流１ｏによって発生したレ
ーザー光６を、発光光量の検出素子として設置された受
光素子としての受光ダイオード８で受け、その受光出力
（受光電流または電圧）のクロック信号によるパルス幅
制御によって駆動制御信号Ｖ４ｃを発生する。この駆動
制ｍ信号Ｖｄｃは、受光ダイオード８の受光出力に応じ
たパルス幅を持つパルスで与えられる。The PWM 14 is installed as a drive control means for the DC/DC 12, and the laser diode 2 is
The laser beam 6 generated by the driving current 1o supplied from C12 is received by the light receiving diode 8 as a light receiving element installed as a detecting element for the amount of emitted light, and the pulse width of the light receiving output (light receiving current or voltage) is determined by the clock signal. A drive control signal V4c is generated by control. This driving control m signal Vdc is given as a pulse having a pulse width corresponding to the light receiving output of the light receiving diode 8.
ところで、ＰＷＭ１４は、受光出力にパルス幅制御を施
すために、クロック信号ＣＬＫを必要とするが、このク
ロック信号ＣＬＫは、光ディスク再生装置に設置された
サーボ系回路１６にクロック信号ＣＬＫを与える発振器
（ＯＳＣ）１Ｂが発生したクロック信号ＣＬＫを利用し
ている。発振器１８は、水晶発振子２０などの発振素子
を用いてクロック信号ＣＬＫを発生する。By the way, the PWM 14 requires a clock signal CLK in order to perform pulse width control on the received light output, and this clock signal CLK is generated by an oscillator ( The clock signal CLK generated by OSC) 1B is used. The oscillator 18 generates a clock signal CLK using an oscillation element such as a crystal oscillator 20.
そして、ＤＣ／ＤＣ１２は、駆動制御信号■。And DC/DC12 is a drive control signal ■.
に基づき、電源電圧ＶＣＣを、レーザーダイオード２の
発光光量を一定にするに必要かつ適正な駆動電圧Ｖ。に
変換し、その駆動電圧ＶＤをレーザーダイオード２のア
ノードに加える。たとえば、駆動電圧ｖ３の値は、レー
ザーダイオード２を効率的に駆動する電圧範囲内で制御
され、受光ダイオード８の受光光量が少ない場合には高
く、また、受光ダイオード８の受光光量が多い場合には
低くなる。Based on this, the power supply voltage VCC is set to a necessary and appropriate driving voltage V to keep the amount of light emitted from the laser diode 2 constant. , and the driving voltage VD is applied to the anode of the laser diode 2. For example, the value of the driving voltage v3 is controlled within a voltage range that efficiently drives the laser diode 2, and is high when the amount of light received by the light receiving diode 8 is small, and is high when the amount of light received by the light receiving diode 8 is large. becomes lower.
したがって、このようなレーザー駆動回路では、電源電
圧ＶＣＣをサーボ系回路１６や他の駆動回路と共通化し
ながら、受光ダイオード８の受光光量に基づきＰＷＭ１
４から得られた駆動制御信号Ｖｄｃに応じてＤＣ／ＤＣ
１２から適正な駆動電圧Ｖ、をレーザーダイオード２に
加えて、駆動電流Ｉゎを流す。それゆえ、レーザーダイ
オード２は、常に適正かつ発光光量を一定にするための
駆動電圧ＶＤで駆動され、無効電力の削減とともに、駆
動トランジスタを用いた場合による電力消費を削減でき
る。Therefore, in such a laser drive circuit, the power supply voltage VCC is shared with the servo system circuit 16 and other drive circuits, and the PWM1 is controlled based on the amount of light received by the light receiving diode 8.
DC/DC according to the drive control signal Vdc obtained from 4.
A suitable driving voltage V from 12 is applied to the laser diode 2, and a driving current I2 is caused to flow. Therefore, the laser diode 2 is always driven with a drive voltage VD to keep the amount of emitted light constant and appropriate, and it is possible to reduce reactive power and power consumption when using a drive transistor.
第２図は、第１図に示した光ディスク再生装置のレーザ
ー駆動回路におけるＤＣ／ＤＣ１２およびＰＷＭ１４の
具体的な構成例を示す。FIG. 2 shows a specific example of the configuration of the DC/DC 12 and PWM 14 in the laser drive circuit of the optical disc reproducing apparatus shown in FIG.
ＤＣ／ＤＣ１２は、ＰＷＭ１４の出力によって駆動トラ
ンジスタ２２を動作させ、この駆動トランジスタ２２を
通じて流れるパルス電流を平滑回路２４に加えて平滑し
、レーザーダイオード２の駆動電流ＩＤを得る。The DC/DC 12 operates the drive transistor 22 by the output of the PWM 14, applies the pulse current flowing through the drive transistor 22 to the smoothing circuit 24, and smoothes it to obtain the drive current ID of the laser diode 2.
ＰＷＭ１４は、クロック信号ＣＬＫとして第３図のＡに
示すクロックパルスＣＬＫを基準波形発生回路２６に加
えて、第３図のＢのＢ１に示すように、三角波または鋸
歯状波を基準波形として発生させるとともに、受光光量
に比例して受光ダイオード８に流れる電流を電流・電圧
変換回路（Ｉ／Ｖ）２８に加えて、第３図のＢの８２に
示す電圧に変換した後、基準波形電圧とＩ／Ｖ２８の出
力電圧をコンパレータ３０に加えて、第３図のＣに示す
パルス幅変調（ＰＷＭ）出力を得る。駆動トランジスタ
２２は、ＰＷＭ出力によって導通、遮断を繰り返し、そ
の導通区間は、第３図のＢおよびＣから明らかなように
、受光ダイオード８の受光電流に対応する電圧の増減に
応じたものとなる。そして、このようなスイッチング動
作によって、トランジスタ２２を通して断続電流は、第
３図のＤに示すように、平滑回路２４を通して平滑化さ
れてレーザーダイオード２に流れる。The PWM 14 adds a clock pulse CLK shown in A of FIG. 3 to the reference waveform generation circuit 26 as a clock signal CLK, and generates a triangular wave or a sawtooth wave as a reference waveform as shown in B1 of B in FIG. At the same time, the current flowing through the light receiving diode 8 in proportion to the amount of received light is applied to the current/voltage conversion circuit (I/V) 28, and after converting it into the voltage shown at 82 in B of FIG. 3, the reference waveform voltage and I The output voltage of /V28 is applied to comparator 30 to obtain a pulse width modulated (PWM) output shown at C in FIG. The drive transistor 22 repeatedly turns on and off in response to the PWM output, and the period of conduction corresponds to the increase or decrease in the voltage corresponding to the light-receiving current of the light-receiving diode 8, as is clear from B and C in FIG. . By such a switching operation, the intermittent current flowing through the transistor 22 is smoothed through the smoothing circuit 24 and flows to the laser diode 2, as shown in FIG. 3D.
したがって、受光ダイオード８の受光電流が多いとき、
ＰＷＭ出力のパルス幅が小さくなって、レーザーダイオ
ード２に流れる駆動電流■。が城少し、また、受光電流
が少ないとき、ＰＷＭ出力のパルス幅が大きくなってレ
ーザーダイオード２に流れる駆動電流Ｉゎが増加するの
で、受光ダイオード８の受光光量に応じてレーザーダイ
オード２の駆動電流■。が制御され、レーザーダイオー
ド２から一定の発光光量が得られる。Therefore, when the light receiving current of the light receiving diode 8 is large,
The pulse width of the PWM output becomes smaller, and the drive current flowing through the laser diode 2 becomes ■. Also, when the light receiving current is small, the pulse width of the PWM output increases and the drive current I flowing through the laser diode 2 increases, so the drive current of the laser diode 2 changes depending on the amount of light received by the light receiving diode 8. ■. is controlled, and a constant amount of emitted light is obtained from the laser diode 2.
なお、この発明には、次のような変形例が考えられる。In addition, the following modifications can be considered to this invention.
（ａ） ＰＷＭ１４に対するクロック信号ＣＬＫに再
生音声信号のサンプリング信号を用いる。このようにし
た場合、サンプリング信号によるビート妨害がなく、音
質低下が防止できる。(a) A sampling signal of the reproduced audio signal is used as the clock signal CLK for the PWM 14. In this case, there is no beat interference caused by the sampling signal, and deterioration in sound quality can be prevented.
（ｂｌ また、クロック信号ＣＬＫに、光ディスクの
再生ピットから得られたクロック信号またはその分周信
号を用いる。このようにすれば、ビントクロツクを再生
する位相同期ループの同期状態を乱すことがない。(bl) Furthermore, the clock signal obtained from the reproduction pit of the optical disc or its frequency-divided signal is used as the clock signal CLK. By doing so, the synchronization state of the phase-locked loop for reproducing the bin clock is not disturbed.
以上説明したように、この発明によれば、電源電圧を他
の回路と共通化できるとともに、その電源電圧を直流−
直流変換手段で適正な駆動電圧に変換して、レーザーダ
イオードを駆動し、受光ダイオードで得られた受光出力
に応じて駆動制御手段から得られた駆動制御信号で駆動
電圧を制御するので、無効電圧の削減とともに、駆動ト
ランジスタを用いた場合の電力消費の削減によって駆動
効率の向上が図られ、常に効率的な動作によって一定の
光量を持つレーザー光を得ることができる。As explained above, according to the present invention, the power supply voltage can be shared with other circuits, and the power supply voltage can be changed from DC to
The DC conversion means converts the driving voltage to an appropriate driving voltage to drive the laser diode, and the driving voltage is controlled by the driving control signal obtained from the driving control means in accordance with the light receiving output obtained by the light receiving diode, so the reactive voltage is reduced. In addition to the reduction in power consumption when using a drive transistor, drive efficiency is improved by reducing power consumption, and laser light with a constant amount of light can be obtained through efficient operation at all times.
第１図はこの発明の光ディスク再生装置のレーザー駆動
回路の実施例を示す回路図、第２図は第１図に示した光
ディスク再生装置のレーザー駆動回路の具体的な構成例
を示す回路図、第３図は第２図に示した回路の動作を示
す図、第４図は従来の光ディスク再生装置のレーザー駆
動回路を示す回路図である。
２・・・レーザーダイオード
６・・・レーザー光
８・・・受光ダイオード（受光素子）
１２・・・ＤＣ−ＤＣコンバータ（直流−直流変換手段
）
１４・・・パルス幅制御回路（駆動制御手段）第１図
第２図FIG. 1 is a circuit diagram showing an embodiment of the laser drive circuit of the optical disc playback device of the present invention, and FIG. 2 is a circuit diagram showing a specific example of the configuration of the laser drive circuit of the optical disc playback device shown in FIG. FIG. 3 is a diagram showing the operation of the circuit shown in FIG. 2, and FIG. 4 is a circuit diagram showing a laser drive circuit of a conventional optical disk reproducing apparatus. 2... Laser diode 6... Laser light 8... Light receiving diode (light receiving element) 12... DC-DC converter (DC-DC conversion means) 14... Pulse width control circuit (drive control means) Figure 1 Figure 2
Claims (1)
受け、その受光出力に応じた駆動制御信号を出力する駆
動制御手段と、 この駆動制御手段が発生した駆動制御信号に応じた駆動
電圧をレーザーダイオードに加えて駆動電流を流す直流
−直流変換手段とを備えた光ディスク再生装置のレーザ
ー駆動回路。[Scope of Claims] A drive control means for receiving laser light generated by a laser diode with a light receiving element and outputting a drive control signal according to the received light output; and a drive control means for outputting a drive control signal according to the received light output; A laser drive circuit for an optical disc playback device, comprising a DC-DC conversion means for applying a voltage to a laser diode and passing a drive current.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61265767A JP2515760B2 (en) | 1986-11-07 | 1986-11-07 | Laser drive circuit of optical disk reproducing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61265767A JP2515760B2 (en) | 1986-11-07 | 1986-11-07 | Laser drive circuit of optical disk reproducing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63121141A true JPS63121141A (en) | 1988-05-25 |
| JP2515760B2 JP2515760B2 (en) | 1996-07-10 |
Family
ID=17421740
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61265767A Expired - Lifetime JP2515760B2 (en) | 1986-11-07 | 1986-11-07 | Laser drive circuit of optical disk reproducing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2515760B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100432256B1 (en) * | 2000-06-05 | 2004-05-22 | 닛폰 프레시죤 써키츠(주) | Method of controlling laser diode in optical disk player and circuit therefor |
| JP2007042795A (en) * | 2005-08-02 | 2007-02-15 | Brother Ind Ltd | Semiconductor laser driving device and image forming apparatus |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6374723U (en) * | 1986-11-04 | 1988-05-18 |
-
1986
- 1986-11-07 JP JP61265767A patent/JP2515760B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6374723U (en) * | 1986-11-04 | 1988-05-18 |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100432256B1 (en) * | 2000-06-05 | 2004-05-22 | 닛폰 프레시죤 써키츠(주) | Method of controlling laser diode in optical disk player and circuit therefor |
| JP2007042795A (en) * | 2005-08-02 | 2007-02-15 | Brother Ind Ltd | Semiconductor laser driving device and image forming apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2515760B2 (en) | 1996-07-10 |
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