JPS59186383A - Driving device for laser - Google Patents

Driving device for laser

Info

Publication number
JPS59186383A
JPS59186383A JP6145283A JP6145283A JPS59186383A JP S59186383 A JPS59186383 A JP S59186383A JP 6145283 A JP6145283 A JP 6145283A JP 6145283 A JP6145283 A JP 6145283A JP S59186383 A JPS59186383 A JP S59186383A
Authority
JP
Japan
Prior art keywords
circuit
laser
modulation
output
light
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
JP6145283A
Other languages
Japanese (ja)
Inventor
Tokuichi Tsunekawa
恒川 十九一
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 JP6145283A priority Critical patent/JPS59186383A/en
Priority to US06/525,174 priority patent/US4639924A/en
Publication of JPS59186383A publication Critical patent/JPS59186383A/en
Pending legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00Semiconductor lasers
    • H01S5/06Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
    • H01S5/068Stabilisation of laser output parameters
    • H01S5/06804Stabilisation of laser output parameters by monitoring an external parameter, e.g. temperature
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00Semiconductor lasers
    • H01S5/06Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
    • H01S5/068Stabilisation of laser output parameters
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00Semiconductor lasers
    • H01S5/06Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
    • H01S5/068Stabilisation of laser output parameters
    • H01S5/06808Stabilisation of laser output parameters by monitoring the electrical laser parameters, e.g. voltage or current
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00Semiconductor lasers
    • H01S5/06Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
    • H01S5/068Stabilisation of laser output parameters
    • H01S5/06825Protecting the laser, e.g. during switch-on/off, detection of malfunctioning or degradation

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optics & Photonics (AREA)
  • Semiconductor Lasers (AREA)

Abstract

PURPOSE:To prevent the continuous beam-projection of a laser at the time when the modulation driving circuit broke down and to ensure the safety of the driving device by a method wherein a circuit, which can detect the state of modulation of a circuit to modulate the output of the laser, and a circuit, which controls the driving power source of the laser on the basis of the detected signal, are provided. CONSTITUTION:The output of a laser diode LD is modulated by a modulation circuit 102 in the driving device of a laser and the modulated laser beam is applied to a modulation state detecting circuit 103 and a circuit 106 which confirms the operation of the circuit 103. The state of modulation of the laser is detected by this circuit 103 and the detected signal is applied to a power source driving circuit 104. The output of this circuit 104 is inputted in the circuit 106 and when the modulation circuit 102 is in abnormal operation, the supply of power source to the diode LD is broken. When the modulation circuit 102 and the circuit 103 broke down, a warning circuit 105 is actuated, thereby preventing the continuous beam-projection of the laser and ensuring the safety to the human body.

Description

【発明の詳細な説明】 本発明はレーザーの駆動装置に関するもので、特に駆動
装置が故障した場合に安全を確保するためのものである
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser driving device, and particularly to ensuring safety when the driving device breaks down.

従来、発光ダイオードの光を変調して断続光として被写
体に投光し、被写体からの反射光を検知して被写体まで
の距離を検出する距離検出装置が知られている。
2. Description of the Related Art Conventionally, a distance detection device is known that modulates light from a light emitting diode and projects it onto a subject as intermittent light, and detects reflected light from the subject to detect the distance to the subject.

例えは第1図に距離検出装置の原理構成の一例の概略が
示しである。
For example, FIG. 1 schematically shows an example of the basic configuration of a distance detection device.

EDは変調回路(本図に於て省略)により変調され断続
光を発生する発光ダイオード等の投光用光源で、該光源
は初期状態にあっては図の実線位置にあり、右方向(矢
示X方向)に移動する。LSlは光源EDからの投光を
被写体へ照射させる投光レンズである。−光源EDはX
方向へ移動するため、受光レンズL 3.2の光軸LC
2上に位置する被写体に対し光源EDからの投光は遠距
離から近距離まで走査する。FDは受光素子で受光レン
ズLS2を介して入射する上記投光による被写体からの
反射光を受光する。該受光素子FDの出力は不図示の公
知の処理回路によって検知され、上記光源EDの移動に
際し受光素子が最大の出力を発生した時点を検知する。
ED is a light source such as a light emitting diode that generates intermittent light modulated by a modulation circuit (omitted in this figure). In the initial state, the light source is located at the solid line position in the figure, and is directed toward the right (arrow). (X direction). LSl is a light projection lens that irradiates the object with light projected from the light source ED. -Light source ED is X
The optical axis LC of the light receiving lens L3.2
The light projected from the light source ED scans the object located above 2 from a long distance to a short distance. The FD is a light-receiving element that receives reflected light from a subject due to the above-mentioned light projection, which is incident through the light-receiving lens LS2. The output of the light receiving element FD is detected by a known processing circuit (not shown), which detects the point in time when the light receiving element generates the maximum output when the light source ED is moved.

LS3は撮影レンズで、光源EDの左右方向の移動即ち
投光が光軸LC2方向の走査する動作に連動して、光軸
LC3方向に移動する。SHはシャンクで受光素子出力
が最大のとき動作する。FLはフィルムである。
LS3 is a photographic lens, which moves in the direction of the optical axis LC3 in conjunction with the movement of the light source ED in the left-right direction, that is, the scanning operation of the projected light in the direction of the optical axis LC2. SH operates when the light receiving element output is maximum at the shank. FL is film.

合波写体かOH2の位置にあるとすると、光源EDが実
線の位置にあるときに光源EDからの投光が被写体OB
2に照射される。よって、この状態における受光素子F
Dの出力が最大値を示し、その信号により撮影レンズ駆
動源(不図示)を停止にさせ、撮影レンズLS3の位置
は被写体OB2の位置に応じたものに調定される。又、
被写体がOBIの位置にある場合は光源EDがX方向に
移動し鎖線の位置まできたとき光源EDからの投光が被
写体OB2に照射され、この時点における受光素子FD
の出力が最大値を示す。その信号により撮影レンズ駆動
源が停止し撮影レンズLS3のY方向への移動も停止し
、撮影レンズの位置が被写体OBIに応じた位置に調定
される。調定された位置でシャッタSHを動作させ、フ
ィルムF上に撮影が行われる。
Assuming that the combined object is at the position of OH2, when the light source ED is at the position of the solid line, the light emitted from the light source ED will be at the position of the object OB.
2. Therefore, the light receiving element F in this state
The output of D shows the maximum value, and the signal causes the photographic lens drive source (not shown) to stop, and the position of the photographic lens LS3 is adjusted according to the position of the subject OB2. or,
When the subject is at the OBI position, the light source ED moves in the X direction and when it reaches the position indicated by the chain line, the light source ED illuminates the subject OB2, and the light receiving element FD at this point
The output of indicates the maximum value. In response to this signal, the photographing lens drive source is stopped, the movement of the photographing lens LS3 in the Y direction is also stopped, and the position of the photographing lens is adjusted to a position corresponding to the object OBI. The shutter SH is operated at the adjusted position, and a photograph is taken on the film F.

ところが発光ダイオードなどの光源LEの投光の強度が
弱いため、検出限界距離が、せいぜい10メ一トル程度
と非常に短いものである。遠距離まで高精度に距離検出
を行うためには指向性の強い、強力な出力の光源が必要
で、レーザー光が用いられている。レーザーには気体レ
ーザーを始めとして各種のものがあるが、カメラ等の携
帯品に使用するには半導体レーザーのように小型軽量の
ものが好ましい。最近半導体レーザーの価格が低下し、
安価な機器にも使用が可能になってきている。被写体が
人間である場合に半導体レーザーの光は強いので、駆動
回路系が正常に作動しないと許容量以上の光が投射され
人体に害を及ぼす恐れがある。
However, since the intensity of the light emitted from the light source LE such as a light emitting diode is weak, the detection limit distance is very short, about 10 meters at most. In order to accurately detect distances over long distances, a highly directional and powerful light source is required, and laser light is used. There are various types of lasers including gas lasers, but small and lightweight ones such as semiconductor lasers are preferred for use in portable items such as cameras. Recently, the price of semiconductor lasers has decreased,
It has become possible to use it in inexpensive equipment. When the subject is a human being, the light from the semiconductor laser is strong, so if the drive circuit system does not operate properly, more light than the permissible amount will be projected, potentially causing harm to the human body.

そこで本発明は半導体レーザーの光を変調して断続光と
して被写体に投光し被写体からの反射光を検知して遠距
離まで高精度に距離検出を行う装置等で、変調駆動回路
が故障して例えば連続投光された場合には連続投光を検
知して、必要な処置を取り人体への安全を確保する装置
を提供することを目的とするものである。
Therefore, the present invention is a device that modulates the light of a semiconductor laser, emits it as intermittent light onto a subject, detects the reflected light from the subject, and detects distance with high precision over a long distance. For example, the object of the present invention is to provide a device that detects continuous light projection and takes necessary measures to ensure safety for the human body.

この目的を達成するため本発明は、レーザーの出力を変
調する変調回路102と、その変調状態を検知する回路
103と、検知した信号に基ついてレーザーの駆動電源
を制御する回路104とを持つことを特徴とするレーザ
ーの駆動装置である。
To achieve this object, the present invention includes a modulation circuit 102 that modulates the laser output, a circuit 103 that detects the modulation state, and a circuit 104 that controls the laser drive power source based on the detected signal. This is a laser driving device characterized by:

以下図面に記載された実施例を詳細に説明して本発明の
構成を明らかにする。
DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments shown in the drawings will be described in detail below to clarify the structure of the present invention.

第2図は本発明を適用する駆動装置の回路の実施例であ
る。図中102はレーザーの変調回路で、定電圧電源R
EG、発振回路03C1演算増幅器opi、トランジス
タT r’ 1・Tr2、抵抗R1−R2−R3、サー
ミスタ抵抗RT、レーザーダイオードLDからなる。1
03は変調状態を検出する回路でトランジスタTr5・
Tr6、抵抗R7・R8−R9・RIO−R11、コン
デンサーCI、コンパレータcpiからな。104は駆
動電源を制御する回路でトランジスタTr8・Tri 
1、抵抗R12−Rl7からなる。105は警告を発す
る回路でトランジスタTrQ・Trlo、抵抗R13・
R14・R15、発光ダイオ−トL Eからなる。10
6は変調状態を検出する回路103が正常に動作してい
るかどうかを確認する回路で、テストスイッチSW2、
トランジスタTr3・Tr4・Tr7、オアゲー1− 
OR、ワンショント回路OH3からなる。直流電源E・
メインスインチSW1φ直流−直流コンバータCDCは
上記各回路に電源を供給するものである。この他コンデ
ンサC2、抵抗R16、オアケート。
FIG. 2 shows an embodiment of a circuit of a driving device to which the present invention is applied. In the figure, 102 is a laser modulation circuit, and a constant voltage power supply R
It consists of EG, oscillation circuit 03C1 operational amplifier opi, transistors Tr' 1 and Tr2, resistors R1-R2-R3, thermistor resistor RT, and laser diode LD. 1
03 is a circuit for detecting the modulation state, and the transistor Tr5.
From Tr6, resistors R7, R8-R9, RIO-R11, capacitor CI, and comparator cpi. 104 is a circuit for controlling the drive power supply, and transistors Tr8 and Tri
1. Consists of resistors R12-Rl7. 105 is a circuit for issuing a warning, which includes transistors TrQ and Trlo, and resistors R13 and Trlo.
It consists of R14, R15, and a light emitting diode LE. 10
6 is a circuit for checking whether the circuit 103 for detecting the modulation state is operating normally; test switch SW2;
Transistors Tr3, Tr4, Tr7, or game 1-
Consists of OR and one-shot circuit OH3. DC power supply E・
The main switch SW1φ DC-DC converter CDC supplies power to each of the above circuits. In addition, capacitor C2, resistor R16, or.

R、トランジスタTr7から成る回路はメインスイッチ
SWlを入れたときにコンデンサCIをイニシャルクリ
アする回路である。
The circuit consisting of R and transistor Tr7 is a circuit that initializes the capacitor CI when the main switch SWl is turned on.

f33図は第2図の主要部のタイミングチャートである
Figure f33 is a timing chart of the main parts of Figure 2.

第3図を参照しながら第2図に示す回路の具体的動作を
説明する。
The specific operation of the circuit shown in FIG. 2 will be explained with reference to FIG.

変調回路102に於て、演算増幅器0PI−の非反転入
力には定電圧電源REGがらの定電圧が印加され、反転
入力と出力との間には抵抗R1とトランジスタTriと
レーザーダイオードLDとで帰還路が形成されるので入
力端子間の電位はほぼ同じになり抵抗R3と温度補償用
サーミスタRTとの合成抵抗によりレーザーダイオード
LDの電流が制御されする。発振回路O8c、抵抗R2
、トランジスタTr2によりトランジスタTriの導通
が制御されてレーザーダイオードL Dの出力が変調さ
れる。即ち、レーザーダイオードLDは発振回路O8C
の発振パルスに同期して断続発光する。トランジスタT
riを始めとして変調回路102が正常に作動している
間は、レーザーダイオ−1”LDと抵抗R3の接続点P
の電位が第3図 (A)の波形になる。 (A)の波形
が高レベル側の間では、レーザーダイオードLDが発光
し、変調状態検出回路103のトランジスタTr5がオ
ン、トランジスタTr6がオフするので秒時積分用コン
デンサC1は、抵抗R9を介して第3図(B)の如き波
形で充電される。(A)の波形が低レベル側の間ではレ
ーザーダイオードLDは発光しないで、トランジスタT
r5がオフ、トランジスタTr6がオンするのでコンデ
ンサC1は第3図 (B)の如き波形で放電されコンデ
ンサC,1の端子電圧は抵抗RLO・R11より快まる
しきい値電圧VTRには達しないのでコンパレータCP
Lの出力は高出力のままである。従って駆動電源制御回
路104のTr8*丁rllがオンになっておりレーザ
ータイオートLDを駆動するための給電が保持される。
In the modulation circuit 102, a constant voltage from a constant voltage power supply REG is applied to the non-inverting input of the operational amplifier 0PI-, and feedback is provided between the inverting input and the output by a resistor R1, a transistor Tri, and a laser diode LD. Since a path is formed, the potentials between the input terminals become almost the same, and the current of the laser diode LD is controlled by the combined resistance of the resistor R3 and the temperature compensation thermistor RT. Oscillation circuit O8c, resistor R2
, the conduction of the transistor Tri is controlled by the transistor Tr2, and the output of the laser diode LD is modulated. That is, the laser diode LD is connected to the oscillation circuit O8C.
Emit light intermittently in synchronization with the oscillation pulse. transistor T
While the modulation circuit 102 including ri is operating normally, the connection point P between the laser diode 1''LD and the resistor R3 is
The potential becomes the waveform shown in Figure 3 (A). While the waveform (A) is on the high level side, the laser diode LD emits light, the transistor Tr5 of the modulation state detection circuit 103 is turned on, and the transistor Tr6 is turned off. The battery is charged with a waveform as shown in FIG. 3(B). While the waveform (A) is on the low level side, the laser diode LD does not emit light and the transistor T
Since r5 is off and transistor Tr6 is on, capacitor C1 is discharged with the waveform shown in Figure 3 (B), and the terminal voltage of capacitor C1 does not reach the threshold voltage VTR, which is higher than resistors RLO and R11. Comparator CP
The output of L remains high. Therefore, Tr8*drll of the drive power supply control circuit 104 is turned on, and the power supply for driving the laser tie auto LD is maintained.

第3図(C)の波形は時刻t1に於て変調回路が故障し
レーザーダイオードLDか連続発光状態しこなった場合
のレーザーダイオードL Dと抵抗R3の接続点Pの波
形である。このときコンデンサC1は、第3図 (D)
の如き波形で充電され時刻t2に於て抵抗RIO−R1
1より決まるしきい値電圧VTRを越えるのでコン、(
レークCPIの出力が低出力側に反転しトラジスタTr
8・Tri 1がオフになる。従ってレーザーダイオー
ドLDへの給電が遮断され、不測の連続発光を防止でき
る。
The waveform in FIG. 3(C) is the waveform at the connection point P between the laser diode LD and the resistor R3 when the modulation circuit fails at time t1 and the laser diode LD enters the continuous light emitting state. At this time, the capacitor C1 is as shown in Fig. 3 (D).
At time t2, the resistor RIO-R1 is charged with a waveform such as
Since it exceeds the threshold voltage VTR determined by 1, con, (
The output of Rake CPI is reversed to the low output side and the transistor Tr
8.Tri 1 is turned off. Therefore, the power supply to the laser diode LD is cut off, and unexpected continuous light emission can be prevented.

警告回路105も同様にコンノくレータCPIの出力に
よって動作する。コンパレークCPIの入力電圧がしき
い値VTHより低レベルのときはコンパレータCP1の
出力は高出力でありトランジスタTr9がオンになって
おりトランジスタTr10がオフになっている。従って
発光ダイオ−(ZLEは発光しない。時間がt2になり
入力電圧がしきい値VTHを越えたときはコンパレーク
CP1の出力は低出力側に反転し、トランジスタTr9
がオフになりトランジスタTrioがオンになって発光
ダイオードLEが発光し警告を発する。
The warning circuit 105 is similarly operated by the output of the controller CPI. When the input voltage of the comparator CPI is lower than the threshold value VTH, the output of the comparator CP1 is high, the transistor Tr9 is on, and the transistor Tr10 is off. Therefore, the light emitting diode (ZLE) does not emit light. When time reaches t2 and the input voltage exceeds the threshold value VTH, the output of comparator CP1 is inverted to the low output side, and transistor Tr9
turns off, transistor Trio turns on, and light emitting diode LE emits light to issue a warning.

変調状態を検知する回路103が正常に作動しているか
どうかを検査する回路106で常開型テストスイ・ンチ
SW2を押すと、トランジスタ1丁3φTr4がオンに
なるのでトランジスタTriがオフになりレーザーダイ
オードL Dへの電流供給が遮断される。代りに)・ラ
ンジスタT r 4 ’Ir−介して同等の電流が接続
点Pから抵抗R3、サーミスタRTに供給される。P点
の信号により回路103のトランジスタTr5はオンに
なり、トランジスタTr6はオフになるのでコンデンサ
CLの端子電圧は上昇し、一定時間後多こしきい値電圧
VTHを越える。従って、コンパレータCPIの出力は
低出力側に反転する。その結果回路105の警告表示素
子である発光ダイオードLEが点灯し変調状態を検知す
る回路が正常に作動していることを確認出来る。もし発
光ダイオードLEか点灯しない場合には変調状態検知回
路103のどこかに異常がある。
When the normally open test switch SW2 is pressed in the circuit 106 that tests whether the circuit 103 that detects the modulation state is operating normally, the transistor 1 and 3φTr4 are turned on, so the transistor Tri is turned off and the laser diode L is turned on. The current supply to D is cut off. Instead) an equivalent current is supplied from the connection point P to the resistor R3 and the thermistor RT via the transistor T r 4 'Ir-. The signal at point P turns on the transistor Tr5 of the circuit 103 and turns off the transistor Tr6, so that the terminal voltage of the capacitor CL rises and exceeds the multi-threshold voltage VTH after a certain period of time. Therefore, the output of the comparator CPI is inverted to the low output side. As a result, the light emitting diode LE, which is a warning display element of the circuit 105, lights up, and it can be confirmed that the circuit for detecting the modulation state is operating normally. If the light emitting diode LE does not light up, there is an abnormality somewhere in the modulation state detection circuit 103.

テストスイッチSW2をオフすると立下り同期のワンシ
ョット回路OH3がワンショットパルスを発生するので
オアゲートORを介してトランジスタTr7がオンし、
コンデンサC1に蓄積されている電荷がクリアされ、レ
ーザーダイオードLD駆動回路への給電が再開される。
When the test switch SW2 is turned off, the falling synchronized one-shot circuit OH3 generates a one-shot pulse, so the transistor Tr7 is turned on via the OR gate OR.
The charge accumulated in the capacitor C1 is cleared, and power supply to the laser diode LD drive circuit is restarted.

以上の如く本発明を使用すると通常の動作時極めて安定
した変調発光を続け、一方においてレーザーの駆動状態
を常時監視しているので、変調状態に異常が生じた場合
には、瞬時にレーザーの駆動回路を遮断し被照射物と駆
動装置の安全性を確保出来るという効果がある。
As described above, when the present invention is used, extremely stable modulated light emission continues during normal operation, and at the same time, the laser drive status is constantly monitored, so if an abnormality occurs in the modulation status, the laser drive is instantaneously activated. This has the effect of interrupting the circuit and ensuring the safety of the irradiated object and the drive device.

上記実施例ではレーザーダイオードの変調周期の0.7
5サイクル分だけ連続発光したときに(第3IJ t 
2 ’Jj照)、駆動電源制御回路104・警告回路1
05が動作するようにしであるか、抵抗R10・R11
の値を変えれば回路104・105か動作するタイミン
グを適宜ずらすことができる。
In the above embodiment, 0.7 of the modulation period of the laser diode
When the light is emitted continuously for 5 cycles (3rd IJ t
2 'Jj Teru), drive power supply control circuit 104/warning circuit 1
05 to operate, or resistors R10 and R11.
By changing the value of , the timing at which the circuits 104 and 105 operate can be shifted as appropriate.

なお、警告は上記例のごと〈発光グイオードLEを用い
て光によって行うものだけでなく電子音等の音声によっ
て行うことも可能である。
Note that the warning can be given not only by light using the light emitting diode LE as in the above example, but also by sound such as an electronic sound.

発振回路O3Cは受光素子FD(第1図)の出力に基づ
いて下記の如きデユーティ制御しても良い。発振回路O
3Cの発振周波数を受光素子FDの出力が大きいときに
周波数を増大させ小さいときに減少させ、更に該発振回
路O3Cの出力パルスによってトリガーされるワンショ
ット回路を設け、該ワンショット回路の出力によってト
ランジスタTr2のオンオフ制御を行う。レーザーダイ
オ−1’ L Dからの出力が強くなたときには受光素
子FDの出力も大きくなり、発振回路O3Cの周波数が
増大するため、ワンショット回路で一制御されるトラン
ジスタTr2のデユーティ比が増加しこれに反し!・ラ
ンシスタTriのチューティ比が低下する。そのためレ
ーザーダイオードLDの単位時間あたりの駆動電流量が
小さくなってレーザーダイオ−1’ L Dの出力も弱
まる。又逆にレーザータイオードLDの出力が弱くなっ
たときには発振回路の周波数が減少するためトランジス
タTr2のデユーティ比が低下しこれに反しトランジス
タTriのデユーティ比が増加する。そのためレーザー
ダイオードLDの単位時間あたり駆動電流量が大きくな
ってレーザーダイオードLDの出力も強まる。このよう
に発振回路O3Cの出力を受光素子FDの出力によって
調定すれば、レーザーダイオードLDの出力に変動傾向
か現れてもその変動中を一定に抑え、そのIJ内で距離
検出することが出来る。
The oscillation circuit O3C may perform duty control as described below based on the output of the light receiving element FD (FIG. 1). Oscillation circuit O
The oscillation frequency of 3C is increased when the output of the light receiving element FD is large and decreased when it is small, and a one-shot circuit triggered by the output pulse of the oscillation circuit O3C is provided, and the output of the one-shot circuit is used to increase the frequency of the transistor. Performs on/off control of Tr2. When the output from the laser diode 1'LD becomes stronger, the output from the light receiving element FD also becomes larger, and the frequency of the oscillation circuit O3C increases, so the duty ratio of the transistor Tr2, which is controlled by the one-shot circuit, increases. Contrary to this! - The tutee ratio of the run sister Tri decreases. Therefore, the amount of driving current per unit time of the laser diode LD becomes smaller, and the output of the laser diode 1' LD also becomes weaker. Conversely, when the output of the laser diode LD becomes weak, the frequency of the oscillation circuit decreases, so the duty ratio of the transistor Tr2 decreases, and on the contrary, the duty ratio of the transistor Tri increases. Therefore, the amount of driving current per unit time of the laser diode LD increases, and the output of the laser diode LD also increases. If the output of the oscillation circuit O3C is adjusted by the output of the light receiving element FD in this way, even if the output of the laser diode LD shows a tendency to fluctuate, it is possible to suppress the fluctuation to a constant level and detect distance within that IJ. .

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

第1図は被写体までの距離検出する装置の概略図、第2
図は本発明を適用する駆動装置の回路図、第3図は同上
駆動装置の動作を説明するタイミングチャート図である
。 102は変調回路、103は変調状態検知回路、104
は駆動電源制御回路、105は警告回路、106は変調
状態検知回路の動作を確認する回路、LDはレーザーダ
イオードである。 第3図 ;  ; (: :  i ; 、t+    力2 昭和59年 3月16日 特許庁長官 若 杉 和 夫 殿 1、事件の表示 昭和58年 特  許 願第 61452号2、発明の
名称 レーザーの駆動装置 3、補正をする者 事件との関係  特許 出願人 名  称   (100)キャノン株式会社4、代理人 東京都渋谷区代々木二丁目11番12号木村ビルディン
グ 5、補正の対象  明細書「発明の詳細な説明」の欄、
図面。 6、補正の内容 −7つjじパ。りい5 。 ;1)明細書2頁15・16行「・・・シャンクで受光
素子出力が最大のとき動作する。FLは・・・」とある
のを「・・・シャッタ、FLは・・・」に訂正する。 〔2)同  3頁6行rOB2JをrOBljに訂正す
る。 (3)同  5頁10行「からな。」を「からなる。」
に訂正する。 (4)第2図を別紙に記載の第2図の通りに訂正する。
Figure 1 is a schematic diagram of the device that detects the distance to the subject, Figure 2
The figure is a circuit diagram of a drive device to which the present invention is applied, and FIG. 3 is a timing chart diagram illustrating the operation of the same drive device. 102 is a modulation circuit, 103 is a modulation state detection circuit, 104
105 is a drive power control circuit, 105 is a warning circuit, 106 is a circuit for checking the operation of the modulation state detection circuit, and LD is a laser diode. Figure 3; ; (: : i ; , t+ force 2 March 16, 1980 Kazuo Wakasugi, Commissioner of the Japan Patent Office 1, Indication of the case 1982 Patent Application No. 61452 2, Name of the invention Laser Drive device 3, relationship with the case of the person making the amendment Patent Applicant name (100) Canon Co., Ltd. 4, Agent Kimura Building 5, 2-11-12 Yoyogi, Shibuya-ku, Tokyo, Subject of amendment Specification “Details of the invention "Explanation" column,
drawing. 6. Contents of correction - 7 details. Rii 5. ;1) Changed the text, page 2, lines 15 and 16 of the specification, "...operates when the light-receiving element output is maximum at the shank. FL..." to "...shutter, FL..." correct. [2) Same page 3, line 6, rOB2J is corrected to rOBlj. (3) Same page 5, line 10, "Karana." is replaced with "Karanaru."
Correct. (4) Correct Figure 2 as shown in the attached sheet.

Claims (1)

【特許請求の範囲】[Claims] (1)レーザーの出力を変調する変調回路と、その変調
状態を検知する回路と、検知した信号に基づいてレーザ
ーの駆動電源を制御する回路とを持つことを特徴とする
レーザーの駆動装置。
(1) A laser drive device characterized by having a modulation circuit that modulates the output of the laser, a circuit that detects the modulation state, and a circuit that controls the laser drive power source based on the detected signal.
JP6145283A 1982-09-03 1983-04-07 Driving device for laser Pending JPS59186383A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP6145283A JPS59186383A (en) 1983-04-07 1983-04-07 Driving device for laser
US06/525,174 US4639924A (en) 1982-09-03 1983-08-22 Drive system for a semiconductor laser

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6145283A JPS59186383A (en) 1983-04-07 1983-04-07 Driving device for laser

Publications (1)

Publication Number Publication Date
JPS59186383A true JPS59186383A (en) 1984-10-23

Family

ID=13171446

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6145283A Pending JPS59186383A (en) 1982-09-03 1983-04-07 Driving device for laser

Country Status (1)

Country Link
JP (1) JPS59186383A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4813048A (en) * 1985-10-22 1989-03-14 Fujitsu Limited Semiconductor laser driving device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4813048A (en) * 1985-10-22 1989-03-14 Fujitsu Limited Semiconductor laser driving device

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