JPS6359468B2 - - Google Patents
Info
- Publication number
- JPS6359468B2 JPS6359468B2 JP57033260A JP3326082A JPS6359468B2 JP S6359468 B2 JPS6359468 B2 JP S6359468B2 JP 57033260 A JP57033260 A JP 57033260A JP 3326082 A JP3326082 A JP 3326082A JP S6359468 B2 JPS6359468 B2 JP S6359468B2
- Authority
- JP
- Japan
- Prior art keywords
- avalanche photodiode
- voltage
- charging
- temperature
- bias
- 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
Links
- 239000003990 capacitor Substances 0.000 claims description 15
- 230000001678 irradiating effect Effects 0.000 claims 1
- 230000035945 sensitivity Effects 0.000 description 10
- 230000015556 catabolic process Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 8
- 230000007423 decrease Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/06—Systems determining position data of a target
- G01S17/08—Systems determining position data of a target for measuring distance only
- G01S17/10—Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Description
【発明の詳細な説明】
この発明は、パルスレーザ光を目標にむけて送
出し、目標からの反射光を受信して、パルス光伝
ばん遅延時間から目標までの距離を測定する測距
装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a distance measuring device that transmits pulsed laser light toward a target, receives reflected light from the target, and measures the distance to the target from the pulsed light propagation delay time. It is something.
この種測距装置に用いられるアバランシエホト
ダイオードの感度は、第１図ａに示すように、一
定温度Ｔのもとでは、バイアス電圧増大とともに
上昇し、ブレータダウン電圧VBK以上では、アバ
ランシエホトダイオードは著しい雑音を発してブ
レークダウンをおこす。このブレークダウン電圧
は、同図に示すように温度Ｔが高いほど大きな値
であり、等感度が得られるバイアス電圧VB（Ｔ）
は、第１図ｂの等感度バイアス曲線に示すよう
に、温度上昇とともに大きな値が必要なので、ア
バランシエホトダイオードを一定感度で使用する
ためには、環境温度変化とともにバイアス電圧を
変化させる必要がある。従つて、従来のこの種装
置においては、バイアス電圧を変化させるため
に、次のような手段を用いていた。 As shown in Figure 1a, the sensitivity of the avalanche photodiode used in this type of rangefinder increases as the bias voltage increases at a constant temperature T, and the sensitivity of the avalanche photodiode increases as the bias voltage increases at a constant temperature T. produces a significant noise and causes a breakdown. As shown in the figure, the higher the temperature T, the larger the breakdown voltage, and the bias voltage V B (T) that provides equal sensitivity.
As shown in the equal-sensitivity bias curve in Figure 1b, a larger value is required as the temperature rises, so in order to use an avalanche photodiode with constant sensitivity, it is necessary to change the bias voltage as the environmental temperature changes. . Therefore, in conventional devices of this type, the following means have been used to change the bias voltage.
第２図は従来の装置におけるアバランシエホト
ダイオードバイアス印加回路の構成の１例を示す
図で、１はアバランシエホトダイオード、２は温
度検出器、３はバイアス電圧発生回路である。第
２図において、アバランシエホトダイオード１の
ケース温度が温度検出器２で検出され、温度Ｔに
おいて、第１図ｂに示される電圧VB（Ｔ）を近似
する電圧VB′（Ｔ）を発生するバイアス電圧発生
回路３を用いて、アバランシエホトダイオードに
バイアス電圧が印加されていた。 FIG. 2 is a diagram showing an example of the configuration of an avalanche photodiode bias application circuit in a conventional device, in which 1 is an avalanche photodiode, 2 is a temperature detector, and 3 is a bias voltage generation circuit. In FIG. 2, the case temperature of the avalanche photodiode 1 is detected by a temperature detector 2, which at temperature T produces a voltage V B '(T) which approximates the voltage V B (T) shown in FIG. 1b. A bias voltage is applied to the avalanche photodiode using a bias voltage generating circuit 3.
しかし一般に、VB（Ｔ）を広い温度範囲におい
て精度よく近似する回路は製作が困難であるばか
りでなく、アバランシエホトダイオードの等感度
バイアス曲線は製品ごとに異なるので、１つのア
バランシエホトダイオードに対してVB（Ｔ）を精
度よく近似しても、別の製品に対しては近似精度
が悪くなり、従つて、安定した等感度が広い温度
範囲において得られない欠点があつた。 However, in general, it is not only difficult to manufacture a circuit that accurately approximates V B (T) over a wide temperature range, but also because the equal-sensitivity bias curve of avalanche photodiodes differs from product to product. Even if V B (T) is approximated with high accuracy, the approximation accuracy becomes poor for other products, and therefore, there is a drawback that stable equal sensitivity cannot be obtained over a wide temperature range.
この発明は、バイアス電圧がブレークダウン電
圧に達したときにアバランシエホトダイオードが
発生する雑音を検出し、バイアス電圧をブレーク
ダウンが生じる直前の値に設定しなおすことによ
り、常にアバランシエホトダイオードを、適切な
感度で安定に使用する手段を提供するものであ
る。以下、この発明を、図を用いて詳細に説明す
る。 This invention detects the noise generated by the avalanche photodiode when the bias voltage reaches the breakdown voltage, and resets the bias voltage to the value immediately before breakdown, thereby ensuring that the avalanche photodiode is always properly operated. This provides a means for stable use with high sensitivity. Hereinafter, this invention will be explained in detail using the drawings.
第３図はこの発明の１実施例を示す図で、レー
ザ用充電コンデンサ４は定電流源５で充電され
る。充電コンデンサ４の端子間電圧VCは、第４
図に示すように、充電開始時から時間とともに増
大し、設定された電圧VSに達してのち、レーザ
が発射されてOVに放電低下する。 FIG. 3 is a diagram showing one embodiment of the present invention, in which a laser charging capacitor 4 is charged by a constant current source 5. In FIG. The voltage V C between the terminals of the charging capacitor 4 is
As shown in the figure, the voltage increases with time from the start of charging, and after reaching the set voltage VS , the laser is emitted and the discharge decreases to OV.
上述の定電流源５はまた、抵抗６、ダイオード
７を介して、直列に接続された、容量C1および
C2のバイアス用充電コンデンサ８および９各々
をも充電し、この直列コンデンサ端子間電圧VCC
がアバランシエホトダイオード１に印加される。 The constant current source 5 described above also includes a capacitor C 1 and a capacitor C 1 connected in series via a resistor 6 and a diode 7.
The bias charging capacitors 8 and 9 of C 2 are also charged, and the voltage between the terminals of this series capacitor is V CC
is applied to the avalanche photodiode 1.
VCCが、ある温度におけるブレークダウン電圧
に達すると、アバランシエホトダイオードの出力
を増巾する増巾器１０の出力１１には、ブレーク
ダウンによる雑音が十分な振幅で現われ、レーザ
用充電コンデンサ充電開始時に定められた状態に
設定したフリツプフロツプ１２の状態を反転させ
る。この状態反転により、開閉器１３および１４
は開閉器駆動回路１５により閉じられる。開閉器
１３が閉じることにより、コンデンサ８，９を充
電する電圧はOVに低下するので、それ以降、レ
ーザが発射されるまで、コンデンサ８，９の充電
は停止される。また、開閉器１４が閉じることに
より、VCCは、ブレークダウンが生じたときのバ
イアス電圧VBKのC2／（C1＋C2）倍に低下する。
従つてC1およびC2の値を適切に選ぶことにより、
任意のアバランシエホトダイオードを、常にブレ
ークダウン直前の、感度が等しく十分高い状態で
使用することができるので、アバランシエホトダ
イオードの性能を、広い温度範囲にわたつて、安
定に発揮することができる。 When V CC reaches the breakdown voltage at a certain temperature, breakdown noise appears with sufficient amplitude at the output 11 of the amplifier 10 that amplifies the output of the avalanche photodiode, and charging of the laser charging capacitor starts. The state of the flip-flop 12, which has been set to a predetermined state, is reversed. Due to this state reversal, switches 13 and 14
is closed by the switch drive circuit 15. When the switch 13 closes, the voltage that charges the capacitors 8 and 9 drops to OV, so that charging of the capacitors 8 and 9 is stopped from then on until the laser is emitted. Further, by closing the switch 14, V CC decreases to C 2 /(C 1 +C 2 ) times the bias voltage V BK at the time of breakdown.
Therefore, by choosing the values of C 1 and C 2 appropriately,
Since any avalanche photodiode can be used in a state where the sensitivities are equally high and sufficiently high, just before breakdown, the performance of the avalanche photodiode can be stably exhibited over a wide temperature range.
このように、この発明によれば、アバランシエ
ホトダイオードの製品ごとの特性むら、および環
境温度変化にかかわらず、常にアバランシエホト
ダイオードを等しく高感度の状態で使用すること
ができるので、測距装置の測距能力を安定にする
ことが可能となる。 As described above, according to the present invention, it is possible to always use the avalanche photodiode in an equally highly sensitive state regardless of the uneven characteristics of each avalanche photodiode product and changes in the environmental temperature. It becomes possible to stabilize the ranging ability.
第１図ａはアバランシエホトダイオードの温
度、バイアス電圧に対する感度依存を示す図、第
１図ｂは、等感度が得られる温度とバイアス電圧
の関係を示す図、第２図は従来の装置におけるア
バランシエホトダイオードバイアス印加回路の構
成を示す図、第３図はこの発明の１実施例を示す
図、第４図はレーザ用充電コンデンサ端子間電圧
を示す図であつて、１はアバランシエホトダイオ
ード、２は温度検出器、３はバイアス電圧発生回
路、４はレーザ用充電コンデンサ、５は定電流
源、６は抵抗、７はダイオード８，９はバイアス
用充電コンデンサ、１０は増巾器、１１は増巾器
出力、１２はフリツプフロツプ、１３，１４は開
閉器、１５は開閉器駆動回路である。なお、図
中、同一あるいは相当部分には同一符号を付して
示してある。
Figure 1a is a diagram showing the sensitivity dependence of the avalanche photodiode on temperature and bias voltage, Figure 1b is a diagram showing the relationship between temperature and bias voltage that provides equal sensitivity, and Figure 2 is a diagram showing the dependence of sensitivity on the temperature and bias voltage of an avalanche photodiode. FIG. 3 is a diagram showing the configuration of a photodiode bias application circuit, FIG. 3 is a diagram showing an embodiment of the present invention, and FIG. 4 is a diagram showing the voltage between the terminals of a laser charging capacitor, in which 1 is an avalanche photodiode, 2 is a temperature detector, 3 is a bias voltage generation circuit, 4 is a charging capacitor for laser, 5 is a constant current source, 6 is a resistor, 7 is a diode 8, 9 is a bias charging capacitor, 10 is an amplifier, 11 is an amplifier. 12 is a flip-flop, 13 and 14 are switches, and 15 is a switch drive circuit. In the drawings, the same or corresponding parts are denoted by the same reference numerals.
Claims (1)
射パルス光をアバランシエホトダイオードを用い
て光電変換し、反射光の伝ぱん時間から、目標ま
での距離を求める測距装置において、レーザ用充
電コンデンサの時間とともに増大する端子間電圧
で、アバランシエホトダイオードバイアス充電用
コンデンサを充電する手段と、前記アバランシエ
ホトダイオードがブレークダウン時に発生する雑
音を検出する手段と、前記アバランシエホトダイ
オードブレークダウン時に、前記アバランシエホ
トダイオードバイアス用充電コンデンサの充電を
停止し、端子間電圧を一定割合減ずる手段とを備
えたことを特徴とする測距装置。1. In a distance measuring device that photoelectrically converts the reflected pulsed light obtained by irradiating a target with pulsed laser light using an avalanche photodiode and calculates the distance to the target from the propagation time of the reflected light, the laser charging capacitor is means for charging an avalanche photodiode bias charging capacitor with a voltage across terminals that increases with time; means for detecting noise generated when the avalanche photodiode breaks down; A distance measuring device comprising means for stopping charging of a photodiode bias charging capacitor and reducing a voltage between terminals by a certain percentage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57033260A JPS58150879A (en) | 1982-03-03 | 1982-03-03 | Distance measuring apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57033260A JPS58150879A (en) | 1982-03-03 | 1982-03-03 | Distance measuring apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58150879A JPS58150879A (en) | 1983-09-07 |
| JPS6359468B2 true JPS6359468B2 (en) | 1988-11-18 |
Family
ID=12381541
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57033260A Granted JPS58150879A (en) | 1982-03-03 | 1982-03-03 | Distance measuring apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58150879A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63290077A (en) * | 1987-05-21 | 1988-11-28 | Seiko Epson Corp | Field discrimination circuit |
-
1982
- 1982-03-03 JP JP57033260A patent/JPS58150879A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63290077A (en) * | 1987-05-21 | 1988-11-28 | Seiko Epson Corp | Field discrimination circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58150879A (en) | 1983-09-07 |
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