JPH0439546Y2 - - Google Patents
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- Publication number
- JPH0439546Y2 JPH0439546Y2 JP4700786U JP4700786U JPH0439546Y2 JP H0439546 Y2 JPH0439546 Y2 JP H0439546Y2 JP 4700786 U JP4700786 U JP 4700786U JP 4700786 U JP4700786 U JP 4700786U JP H0439546 Y2 JPH0439546 Y2 JP H0439546Y2
- Authority
- JP
- Japan
- Prior art keywords
- component
- detected light
- light
- chopper
- detected
- 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
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- 238000001514 detection method Methods 0.000 claims description 36
- 238000006243 chemical reaction Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
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- Optical Transform (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Description
【考案の詳細な説明】
産業上の利用分野
本考案は、光検出装置に関するものであり、更
に詳述するならば、被検出光中の直流成分と交流
成分とを簡単な構成で検出する光検出装置にかん
するものである。[Detailed Description of the Invention] Industrial Application Field The present invention relates to a photodetection device, and more specifically, to a light detection device that detects a direct current component and an alternating current component in detected light with a simple configuration. This relates to a detection device.
従来の技術
いわゆる光検出において、被検出光から検出す
べきものには、被検出光の変動成分（以後これを
交流成分と記す）と、変動しない成分（以下これ
を直流成分と記す）とに大別される。Prior Art In so-called photodetection, there are two types of light to be detected: a fluctuating component (hereinafter referred to as AC component) and a non-fluctuation component (hereinafter referred to as DC component) of the detected light. Separated.
例えば、パイロデイテクタの如く、変動しない
被検出光に応答しない検出素子を用いて、上記の
ような被検出光の直流成分を検出するには、チヨ
ツパーと呼ばれる、例えばスリツト付きの円板に
より被検出光を周期的に断続することにより、疑
似的に交流的な信号として検出していた。 For example, in order to detect the DC component of the detected light as described above using a detection element such as a pyrodetector that does not respond to the unchanging detected light, the detected light is By periodically intermittent, it was detected as a pseudo alternating current signal.
このとき、同時に被検出光の交流成分を検出す
る必要がある場合には、第２図にその概略を示す
ように、チヨツパー１に進入する以前に、被検出
光を適当なビームスプリツタ７によつて２つに分
け、その一方の分岐光を前述のようにチヨツパー
１を通過した後検出器３により検出し、もう一方
の分岐光から交流成分を、別の検出器４により検
出することにより、被検出光の直流成分と交流成
分とを検出していた。 At this time, if it is necessary to detect the alternating current component of the detected light at the same time, the detected light is sent to an appropriate beam splitter 7 before entering the chopper 1, as shown schematically in FIG. Therefore, by dividing the light into two, one of the branched lights is detected by the detector 3 after passing through the chopper 1 as described above, and the alternating current component from the other branched light is detected by another detector 4. , the DC component and AC component of the detected light were detected.
これは、チヨツパー１による被検出光の断続に
より、被検出光の交流成分が影響を受け、検出の
精度が低下することを避けるためである。 This is to prevent the alternating current component of the detected light from being affected by the interruption of the detected light by the chopper 1, thereby preventing the detection accuracy from decreasing.
考案が解決しようとする問題点
しかしながら、上述のような構成の光検出装置
は、ひとつの被検出光に対して光−電気の変換系
たる光検出素子が２つ必要であり、両者の感度や
変換効率を厳密に一致させなければならず、装置
の調整が大変であるにもかかわらず、精度の一致
の点では信頼性に欠けるものであつた。Problems to be Solved by the Invention However, the photodetection device configured as described above requires two photodetection elements, which are optical-to-electrical conversion systems, for one detected light, and the sensitivity and Although the conversion efficiency must be precisely matched and the adjustment of the device is difficult, the accuracy of the match is unreliable.
また、このような構成の検出装置は、実質的に
完全に２つの検出装置からなつており且つビーム
スプリツタも必要であるため、装置の構成が大型
化せざるを得なかつた。 Further, since the detection device having such a configuration is substantially completely composed of two detection devices and also requires a beam splitter, the configuration of the device has to be increased in size.
問題点を解決するための手段
本考案者らは、上述の問題を解決するために
は、光電気変換系の数を減じることが必要であ
り、またそのためには、チヨツパーによる被検出
光の交流成分への影響の排除が不可欠であると考
え、検討・研究を重ねた結果、本考案に至つたも
のである。Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors believe that it is necessary to reduce the number of photoelectric conversion systems, and that in order to do so, it is necessary to We believe that it is essential to eliminate the effects on the ingredients, and as a result of repeated consideration and research, we have come up with this invention.
即ち、本考案に従い、被検出光の交流成分より
も断続周波数の高いチヨツパーと、該チヨツパー
を経過した光を検出する光検出素子と、該検出素
子よりの検出信号から前記被検出光の交流成分を
検出する交流成分検出器と、前記検出素子からの
検出信号から、被検出光の直流成分を検出する直
流成分検出器とを備えることを特徴とする光検出
装置が提供される。 That is, according to the present invention, a chopper having a higher intermittent frequency than the alternating current component of the detected light, a photodetecting element that detects the light that has passed through the chopper, and a detection signal from the detecting element detecting the alternating current component of the detected light. There is provided a photodetection device characterized by comprising: an AC component detector that detects the DC component of the detected light from the detection signal from the detection element; and a DC component detector that detects the DC component of the detected light from the detection signal from the detection element.
作 用
本考案に従う光検出装置では、被検出光を、ま
ず被検出光の交流成分よりも充分に高い周波数で
チヨツパーにより断続し、これを光検出素子によ
り電気信号に変換した後に、その電気的な処理に
より、その直流成分と交流成分を検出することを
特徴としている。Function In the photodetection device according to the present invention, the light to be detected is first interrupted by a chopper at a frequency sufficiently higher than the alternating current component of the light to be detected, and after this is converted into an electrical signal by the photodetection element, the electrical signal is It is characterized by detecting the DC component and AC component through processing.
即ち、チヨツパーにより、被検出光は周期的に
断続され、これによつて光を疑似的に交流化し、
直流成分に応答しない検出素子による被検出光の
検出を可能にする。一方、本考案に従う装置で
は、チヨツパーにより被検出光に付与される疑似
交流的変動が、被検出光に本来含まれる交流成分
の周波数よりも充分に高いので、被検出光の断続
による被検出光の交流成分への影響を排除するこ
とができる。 That is, the detected light is periodically interrupted by the chopper, thereby making the light pseudo-alternating current,
It is possible to detect light to be detected by a detection element that does not respond to a DC component. On the other hand, in the device according to the present invention, the pseudo alternating current fluctuation imparted to the detected light by the chopper is sufficiently higher than the frequency of the alternating current component originally included in the detected light. The influence on the AC component can be eliminated.
例えば、光検出装置を、レーザ装置の周波数安
定化のためのレーザ周波数の変動の検出に用いた
場合には、光検出素子により検出される変調周波
数は、制御帯域や変調素子動作帯域によつて変化
するが、概ね数百Hzのオーダであり、従つて、チ
ヨツパによる被検出光の断続の周期を数ｋHz以上
に設定すれば、検出信号がチヨツパによる影響を
受けることはない。そして、このようなチヨツピ
ング周波数は極めて簡単に実現できる。 For example, when a photodetector is used to detect fluctuations in laser frequency for frequency stabilization of a laser device, the modulation frequency detected by the photodetector will depend on the control band and modulation element operating band. Although it varies, it is generally on the order of several hundred Hz. Therefore, if the cycle of intermittent light to be detected by the chopper is set to several kHz or more, the detection signal will not be affected by the chopper. Such a chopping frequency can be realized extremely easily.
このように、本考案に従う光検出装置は、被検
出光の直流成分と交流成分とを共に１基の光検出
素子により電気信号に変換する、両者の間で光検
出素子の感度あるいは変換効率のバラツキによる
誤差が生じることはあり得ない。 As described above, the photodetection device according to the present invention converts both the DC component and the AC component of the detected light into electrical signals using one photodetection element, and changes the sensitivity or conversion efficiency of the photodetection element between the two. It is impossible for errors to occur due to variations.
また、上述のようにして、電気信号に変換され
た被検出光は、被検出光に元々含まれていた交流
成分の周波数と、チヨツパによつて付加された疑
似交流成分とが、１桁のオーダで、明確に相違す
るので、電気的な処理だけで被検出光の２つの成
分を検出する構成とすることができ、検出装置全
体を簡単且つ小型のものに作製できる。 In addition, in the detected light converted into an electric signal as described above, the frequency of the AC component originally contained in the detected light and the pseudo AC component added by the chopper are one digit. Since there is a clear difference in order, the two components of the detected light can be detected by only electrical processing, and the entire detection device can be manufactured easily and compactly.
実施例
以下、本考案について実施例を参照してより具
体的に説明するが、以下に述べられるものは、本
考案の一実施例にすぎず、本考案の技術的範囲を
何等限定するものではない。EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples. However, what is described below is only one example of the present invention, and is not intended to limit the technical scope of the present invention in any way. do not have.
第１図は、本考案に従う光検出装置の構成を、
概略的に示すものである。 FIG. 1 shows the configuration of a photodetector according to the present invention.
It is shown schematically.
第１図に示される如く、本考案に従う光検出装
置は、主に、被検出光を断続するチヨツパ１と光
検出素子３と、更にその後方に並列に接続された
直流成分検出回路５および交流成分検出回路６と
から構成されている。 As shown in FIG. 1, the photodetection device according to the present invention mainly includes a chopper 1 and a photodetection element 3, which intermittent the detected light, and a DC component detection circuit 5 and an AC component detection circuit 5 connected in parallel behind the chopper 1 and the photodetection element 3. It is composed of a component detection circuit 6.
チヨツパ１は、直径方向に切られたスリツトを
有する円板を、被検出光の光路に挿入して回転す
ることによつて被検出光を断続するように構成さ
れている。そして、その回転周波数cは、被検出
光の交流成分の周波数よりも高く設定している。
実際には、被検出光の交流成分の周波数は、通常
概ね数百Hzのオーダであり、従つて、チヨツパに
よる被検出光の断続の周期は数ｋHz以上に設定す
る必要がある。 The chopper 1 is configured to interrupt the detected light by inserting a disk having a diametrically cut slit into the optical path of the detected light and rotating the disk. The rotation frequency c is set higher than the frequency of the alternating current component of the detected light.
In reality, the frequency of the alternating current component of the detected light is usually on the order of several hundred Hz, and therefore the cycle of intermittent detection of the detected light by the chopper needs to be set to several kHz or more.
次いで、上記光検出素子３の出力を受ける直流
成分検出回路５は、中心周波数cのバンドパスフ
イルタと交流／直流変換器を備えている。そし
て、このバンドパスフイルタにより、入力検出信
号から、本来の交流成分などの雑音成分を取り除
くと共に、被検出光にチヨツパ１により付加され
た周波数cの疑似交流成分すなわち直流成分を抽
出し、交流変換器により被検出光の直流成分に相
当する電圧に変換して出力する。 Next, the DC component detection circuit 5 that receives the output of the photodetection element 3 includes a bandpass filter with a center frequency c and an AC/DC converter. Then, using this bandpass filter, noise components such as the original AC component are removed from the input detection signal, and a pseudo AC component of frequency c, that is, a DC component, added to the detected light by the chopper 1 is extracted, and AC conversion is performed. The device converts the detected light into a voltage corresponding to the DC component and outputs it.
交流成分検出回路６は、チヨツパ１のチヨツプ
周波数cの整数倍の周波数（ｎ×c、ただしｎ＝
１、２……ｎ）の成分を減衰するフイルタを備え
ており、チヨツパ１によつて被検出信号に付与さ
れた交流成分を排除した後、被検出光が元来含ん
でいた交流成分を出力する。好ましくは、交流成
分の周波数が予めわかつている場合、その中心周
波数mのバンドパスフイルタを、nfcの減衰特性
のフイルタの代わりに使用する。このような、中
心周波数mのバンドパスフイルタを使用すれば、
交流成分のみを抽出することができる。 The AC component detection circuit 6 has a frequency that is an integral multiple of the chopper frequency c of the chopper 1 (n×c, where n=
It is equipped with a filter that attenuates the components of 1, 2...n), and after eliminating the AC component added to the detected signal by the chopper 1, outputs the AC component originally contained in the detected light. do. Preferably, when the frequency of the AC component is known in advance, a bandpass filter with a center frequency m is used instead of a filter with NFC attenuation characteristics. If you use a bandpass filter like this with a center frequency of m,
Only AC components can be extracted.
本考案に従う光検出装置に入力された被検出光
は、まず、チヨツパ１によつてその交流成分より
も高い周波数で断続され、光検出素子３には断続
光が入射する。従つて、光検出素子３は、恰も交
流の如く周期的に変動する被検出光を検出して電
気信号に変換する。 The detected light input to the photodetection device according to the present invention is first interrupted by the chopper 1 at a higher frequency than its AC component, and the intermittent light is incident on the photodetection element 3. Therefore, the photodetecting element 3 detects the detected light which changes periodically like an alternating current and converts it into an electrical signal.
光検出素子３から出力された検出信号は、直流
成分検出回路５と交流成分検出回路６とにそれぞ
れ送られる。それぞれの検出回路に入力された検
出信号は、前述の如き、各検出回路の処理に付さ
れて、各々被検出光の直流成分と交流成分の検出
値を出力する。 The detection signal output from the photodetection element 3 is sent to a DC component detection circuit 5 and an AC component detection circuit 6, respectively. The detection signal input to each detection circuit is subjected to processing by each detection circuit as described above, and outputs detection values of the DC component and AC component of the detected light, respectively.
考案の効果
以上詳述の如く、本考案に従う光検出装置は、
光−電気変換系たる光検出素子を１基のみとし、
この検出素子からの電気信号を処理して被検出光
の２種の成分を検出する構成としているので、検
出装置の調整等が極めて簡単であることに加え
て、検出された２種の成分の精度等が良く揃う。Effects of the invention As detailed above, the photodetection device according to the invention has the following features:
Only one photodetection element is used as a photo-electrical conversion system,
Since the electrical signal from this detection element is processed to detect two types of components of the detected light, in addition to extremely simple adjustment of the detection device, the two detected components Accuracy etc. are well matched.
また、光−電気変換素子として、光の直流成分
に応答しないものを用いても、本考案に従う光検
出装置では全く問題がない。 Further, even if a photo-electric conversion element that does not respond to the DC component of light is used, there is no problem with the photodetector according to the present invention.
更に、光検出素子を１基のみとすると共に、ビ
ームスプリツタなどを全く使用せず、光学系を原
理的にはチヨツパのみとし、他を電気回路により
構成したことにより、構成を簡単にし、且つ光検
出装置の製造コストを低減することも、本考案の
効果のひとつといえる。 Furthermore, the structure is simplified by using only one photodetecting element, without using any beam splitters, and by using only a splitter as the optical system in principle, and configuring the rest using electrical circuits. Reducing the manufacturing cost of the photodetector can also be said to be one of the effects of the present invention.
第１図は、本考案に従う光検出装置の概略的な
構成を示すものであり、第２図は、従来の光検出
装置の構成を概略的に示すものである。
主な参照番号、１……チヨツパー、３，４……
光検出素子、５……直流検出回路、６……交流検
出回路、７……ビームスプリツタ。
FIG. 1 schematically shows the structure of a photodetector according to the present invention, and FIG. 2 schematically shows the structure of a conventional photodetector. Main reference numbers, 1...Chiyotsupa, 3, 4...
Photodetection element, 5... DC detection circuit, 6... AC detection circuit, 7... Beam splitter.
Claims (1)
ヨツパーと、該チヨツパーを経過した光を検出す
る光検出素子と、該検出素子よりの検出信号から
前記被検出光の交流成分を検出する交流成分検出
器と、前記検出素子からの検出信号から、被検出
光の直流成分を検出する直流成分検出器とを備え
ることを特徴とする光検出装置。 A chopper with a higher intermittent frequency than the alternating current component of the detected light, a photodetecting element that detects the light that has passed through the chopper, and an alternating current component detection that detects the alternating current component of the detected light from the detection signal from the detecting element. What is claimed is: 1. A photodetection device comprising a DC component detector that detects a DC component of detected light from a detection signal from the detection element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4700786U JPH0439546Y2 (en) | 1986-03-28 | 1986-03-28 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4700786U JPH0439546Y2 (en) | 1986-03-28 | 1986-03-28 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62158325U JPS62158325U (en) | 1987-10-07 |
| JPH0439546Y2 true JPH0439546Y2 (en) | 1992-09-16 |
Family
ID=30867198
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4700786U Expired JPH0439546Y2 (en) | 1986-03-28 | 1986-03-28 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0439546Y2 (en) |
-
1986
- 1986-03-28 JP JP4700786U patent/JPH0439546Y2/ja not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62158325U (en) | 1987-10-07 |
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