JP3044380B2 - Optical analyzer - Google Patents
Optical analyzerInfo
- Publication number
- JP3044380B2 JP3044380B2 JP2042261A JP4226190A JP3044380B2 JP 3044380 B2 JP3044380 B2 JP 3044380B2 JP 2042261 A JP2042261 A JP 2042261A JP 4226190 A JP4226190 A JP 4226190A JP 3044380 B2 JP3044380 B2 JP 3044380B2
- Authority
- JP
- Japan
- Prior art keywords
- channel
- voltage value
- high voltage
- negative high
- optical analyzer
- 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 - Fee Related
Links
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Description
【発明の詳細な説明】 （イ）産業上の利用分野 この発明は、光分析装置、特に複数チャンネルの光源
と一個の光電子増倍管を備える光分析装置に関する。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical analyzer, and more particularly to an optical analyzer having a plurality of light sources and a single photomultiplier tube.
（ロ）従来の技術 複数チャンネルの光源と一個の光電子増倍管を備えた
従来の光分析装置の一例を第３図に示している。この光
分析装置は３チャンネルの光源を持つもので、CPU1から
の光源選択信号LSにより、光源ドライバ２が光源3-1、3
-2、3-3を時間順次に駆動し、光源3-1、3-2、3-3から発
せられた光が、測定対象４を経て、一個の光電子増倍管
５に入光される。光電子増倍管５の出力電流はプリアン
プ６で電圧信号に変換され、スイッチ７でチャンネル毎
に時分割で切りかえられてゲインアンプ8-18-2、8-3に
入力され、各チャンネル毎に設定されたゲインで増幅さ
れ、それぞれA/D変換器9-1、9-2、9-3でデジタル信号に
変換され、CPU1に取り込まれ、信号処理されるようにな
っている。なお、光電子増倍管５には、CPU1からの指令
により負高圧電源10より固定の負高圧値が与えられてい
る。(B) Conventional technology FIG. 3 shows an example of a conventional photoanalytical device having a plurality of light sources and one photomultiplier tube. This optical analyzer has a three-channel light source, and the light source driver 2 operates the light sources 3 -1 , 3 -3 based on a light source selection signal LS from the CPU 1 .
-2, 3 -3 time sequentially driven, the light source 3 -1, 3 -2, light emitted from the 3 -3, through the measurement object 4, is incident on one of the photomultipliers 5 . The output current of the photomultiplier tube 5 is converted into a voltage signal by the preamplifier 6, the gain amplifier 28-1 8-2 are switched by time division for each channel in the switch 7, is input to the 8 -3, for each channel The signals are amplified by the set gain, converted into digital signals by A / D converters 9 -1 , 9 -2 , and 9 -3 , respectively, taken into the CPU 1, and subjected to signal processing. The photomultiplier tube 5 is given a fixed negative high voltage value from a negative high voltage power supply 10 according to a command from the CPU 1.
（ハ）発明が解決しようとする課題 上記した従来の光分析装置では、測定対象の特性や各
チャンネルの光源の出力によて、光電子増倍管の出力が
チャンネル毎に著しく相違する。しかし、CPUで各チャ
ンネルの出力を総合して演算処理を行うのに、同じ強度
レベルの信号が必要なので、各チャンネルのゲインアン
プのゲインを個別に設定し、CPUに取り込まれる信号レ
ベルがほぼ同レベルとなるようにしている。具体的に
は、例えばゲインアンプ8-1のゲインを２倍に、ゲイン
アンプ8-2のゲインを30倍に、ゲインアンプ8-3のゲイン
を500倍にという如くである。しかしながらゲインアン
プのゲインをチャンネル毎に個々に変えて設定すると、
そのゲインに応じてノイズも増幅されるので、各チャン
ネルの信号間でS/N比が大きく相違することとなるとい
う問題があった。(C) Problems to be Solved by the Invention In the above-described conventional photoanalyzer, the output of the photomultiplier tube differs significantly for each channel depending on the characteristics of the measurement object and the output of the light source of each channel. However, since the CPU requires signals of the same intensity level to perform arithmetic processing by integrating the output of each channel, the gain of the gain amplifier for each channel is set individually and the signal level taken into the CPU is almost the same. I try to be a level. Specifically, the gain of the gain amplifier 8 -1 doubled, the gain of the gain amplifier 8 -2 30 times, as that the gain of the gain amplifier 8 -3 500 times. However, if the gain of the gain amplifier is changed and set individually for each channel,
Since the noise is also amplified according to the gain, there is a problem that the S / N ratio is largely different between the signals of the respective channels.
この発明は、上記問題点に着目してなされたものであ
って、測定対象物の吸収スペクトラムや、光源の特性な
どに起因する各チャンネルの特性相違にかかわらず等し
いS/N比で測定し得る光分析装置を提供することを目的
としている。The present invention has been made in view of the above problems, and can be measured at the same S / N ratio regardless of the difference between the characteristics of each channel due to the absorption spectrum of the measurement object and the characteristics of the light source. It is intended to provide an optical analyzer.
（ニ）課題を解決するための手段及び作用 この発明の光分析装置は、複数チャンネルの光を時分
割で点灯して、これらの光が測定対象を経て入光するの
を検出する一個の光電子増倍管を有し、この検出された
信号を処理する光分析装置において、 前記光電子増倍管に印加する電圧値を切り替え、各チャ
ンネルの特性相違にかかわらず出力信号をほぼ同レベル
にする負高圧値選択手段と、この負高圧値選択手段を前
記複数チャンネルの選択に同期して時分割で動作させる
手段とを備えたことを特徴とする。(D) Means and Action for Solving the Problems The optical analyzer according to the present invention is a single photoelectron that illuminates a plurality of channels of light in a time-division manner and detects that these lights enter through an object to be measured. An optical analyzer having a multiplier and processing the detected signal, wherein a voltage value applied to the photomultiplier is switched so that an output signal is substantially at the same level irrespective of a difference in characteristics of each channel. A high voltage value selecting means, and means for operating the negative high voltage value selecting means in a time division manner in synchronization with the selection of the plurality of channels are provided.
この光分析装置では、各チャンネルが時分割で選択さ
れるのに応じて、これに同期して負高圧値選択手段も時
分割で切替動作を行う。そのため光電子増倍管には、チ
ャンネルの選択に応じて予め設定された異なる印加電圧
値（負高圧）が時分割で与えられる。したがって設定電
圧値を予め適正に設定しておけば測定対象や光源の特徴
が相違しても、光電子増倍管の出力電流はチャンネル間
でほぼ同レベルのものが得られる。In this optical analyzer, in response to each channel being selected in a time division manner, the negative high voltage value selecting means also performs a switching operation in a time division manner in synchronization with the selection. Therefore, a different applied voltage value (negative high voltage) preset in accordance with the selection of the channel is given to the photomultiplier tube in a time-division manner. Therefore, if the set voltage value is appropriately set in advance, the output current of the photomultiplier can be substantially the same level between the channels even if the characteristics of the measurement object and the light source are different.
（ホ）実施例 以下、実施例によりこの発明をさらに詳細に説明す
る。(E) Examples Hereinafter, the present invention will be described in more detail with reference to examples.
第１図は、この発明の一実施例を示す光分析装置の回
路ブロック図である。この光分析装置は、信号処理を行
うCPU1と、CPU1から出力されるチャンネル選択信号LSに
応じて光源を時間順次に駆動する光源ドライバ２と、こ
の光源ドライバ２によって時間順次に駆動される光源3
-1、3-2、3-3と、これら光源3-1、3-2、3-3より時間順
次に出力される光が測定対象４を経て入光するのを検出
する光電子増倍管５と、この光電子増倍管５の出力電流
を電圧信号に変換するプリアンプ６と、プリアンプ６の
出力を所定値まで増幅するためのゲインアンプ８と、こ
のゲインアンプ８の出力をデジタル信号に変換してCPU1
に与えるA/D変換器９と、さらに光電子増倍管５に電圧
を印加する負高圧電源10と、この負高圧電源10の電圧値
をCPU1からのチャンネル選択信号LSに同期して選択する
負高圧値選択回路11とから構成されている。FIG. 1 is a circuit block diagram of an optical analyzer showing one embodiment of the present invention. The optical analyzer includes a CPU 1 that performs signal processing, a light source driver 2 that drives a light source in time sequence according to a channel selection signal LS output from the CPU 1, and a light source 3 that is driven in time sequence by the light source driver 2.
-1 , 3 -2 , 3 -3 and a photomultiplier tube for detecting that light sequentially output from these light sources 3-1 , 3 -2 , 3 -3 enters through the measuring object 4. 5, a preamplifier 6 for converting the output current of the photomultiplier 5 into a voltage signal, a gain amplifier 8 for amplifying the output of the preamplifier 6 to a predetermined value, and converting the output of the gain amplifier 8 into a digital signal. And CPU1
, A negative high-voltage power supply 10 for applying a voltage to the photomultiplier 5, and a negative voltage for selecting the voltage value of the negative high-voltage power supply 10 in synchronization with a channel selection signal LS from the CPU 1. And a high voltage value selection circuit 11.
負高圧電源10は、光電子増倍管５に供給する負高圧値
を切り替える機能を有しており、例えばその負高圧値は
CPU1に入力される信号レベルが各チャンネルで略同レベ
ルであるとともに、S/N比も同程度になるように予め適
正に設定された負高圧値をチャンネル毎に与えることに
なる。例えばチャンネル１については800V、チャンネル
２については500V、チャンネル３については1300Vの如
くであり、これら各負高圧値の選択はチャンネル１の選
択信号が負高圧値選択回路11に入力されると、負高圧値
選択回路11が負高圧電源10の800Vを、チャンネル２につ
いては500V、チャンネル３については1300Vをそれぞれ
選択するように構成されている。The negative high voltage power supply 10 has a function of switching a negative high voltage value to be supplied to the photomultiplier tube 5. For example, the negative high voltage value is
A negative high voltage value appropriately set in advance is given to each channel so that the signal level input to the CPU 1 is substantially the same in each channel and the S / N ratio is also substantially the same. For example, 800 V for channel 1, 500 V for channel 2, 1300 V for channel 3, and these negative high voltage values are selected when a selection signal of channel 1 is input to negative high voltage value selection circuit 11. The high voltage value selection circuit 11 is configured to select 800V of the negative high voltage power supply 10, 500V for channel 2, and 1300V for channel 3.
以上のように構成される光分析装置において、CPU1よ
り光源ドライバ２にチャンネル選択信号LSを与え、光源
ドライバ２はこのチャンネル選択信号LSに応じ、各光源
3-1、3-2、3-3に時間順次に第２図に示すドライブ信号L
S1、LS2、LS3を与える。これらドライブ信号LS1、LS2、
LS3はそれぞれ時間順次にONするように構成されてお
り、したがってドライブ信号LS1がONの時には、光源3-1
がONし、順次ドライブ信号LS2、LS3が入力されるタイミ
ングに光源3-2、3-3がそれぞれ点灯する。点灯した光は
測定対象４を経て、光電子増倍管５で受光される。この
光電子増倍管５の負高圧値は１チャンネルが選択されて
いる場合には、第２図に示すように、チャンネル選択信
号LSによって負高圧電源10の800Vが選択され、光電子増
倍管はこの負高圧値による電流増倍率で信号を出力し、
その出力電流をプリアンプ６で電圧信号に変換し、ゲイ
ンアンプ８で信号を増幅し、A/D変換器９でデジタル信
号に変換しCPU1に入力する。次に、光源3-2が選択され
ている場合には、光電子増倍管５に与えられる負高圧値
は、第２図の例では500Vであり、やはり同様に負高圧値
に応じた信号を出力し、チャンネル３の、つまり光源3
-3の点灯時には、同様に光電子増倍管５には負高圧値は
1300Vが印加される。その結果、それぞれ測定対象の光
学的特性や各光源の出力特性が相違しても結果的に光電
子増倍管５から出力される信号はほぼ同レベルとなり、
S/N比も略同一レベルで出力される。In the optical analyzer configured as described above, the CPU 1 supplies a channel selection signal LS to the light source driver 2, and the light source driver 2 responds to this channel selection signal LS
3 -1, 3 -2, 3 -3 time sequentially in the drive shown in FIG. 2 signal L
Give S 1 , LS 2 , LS 3 . These drive signals LS 1 , LS 2 ,
Each of the LSs 3 is configured to be turned on in time sequence, so that when the drive signal LS 1 is turned on, the light source 3 -1 is turned on.
Are turned on, and the light sources 3-2 and 3-3 are turned on at the timing when the drive signals LS 2 and LS 3 are sequentially input. The illuminated light passes through the measuring object 4 and is received by the photomultiplier tube 5. When one channel is selected as the negative high voltage value of the photomultiplier tube 5, 800 V of the negative high voltage power supply 10 is selected by the channel selection signal LS as shown in FIG. A signal is output at the current multiplication factor by this negative high voltage value,
The output current is converted into a voltage signal by a preamplifier 6, the signal is amplified by a gain amplifier 8, converted to a digital signal by an A / D converter 9, and input to the CPU 1. Next, when the light source 3-2 is selected, the negative high voltage value given to the photomultiplier tube 5 is 500 V in the example of FIG. Output, for channel 3, ie light source 3
When -3 is lit, similarly, the negative high voltage value is applied to the photomultiplier tube 5.
1300V is applied. As a result, the signal output from the photomultiplier tube 5 is substantially at the same level even if the optical characteristics of the object to be measured and the output characteristics of each light source are different.
The S / N ratio is also output at substantially the same level.
なお、上記実施例では、光源を３個、つまり３チャン
ネルとしているが、光源の数については、特に３個に限
られるものではなく、２個あるいは４個以上であっても
よい。また光源そのものは１個であってもフィルタ等で
分光して複数チャンネルとし、この複数チャンネルの信
号を測定対象に入光する場合にも、この発明が適用でき
る。In the above embodiment, the number of light sources is three, that is, three channels. However, the number of light sources is not particularly limited to three, and may be two or four or more. The present invention is also applicable to a case where a single light source itself is split into a plurality of channels by using a filter or the like and signals of the plurality of channels enter a measurement target.
（ヘ）発明の効果 この発明によれば、測定対象や、光源による各チャン
ネルの相違を考慮し、CPU1への入力レベルを一定とする
ために光電子増倍管に印加される負高圧値を各チャンネ
ル選択に同期して時分割で選択するようにしているの
で、各チャンネル毎の特性が相違しても、常に略一定レ
ベルの信号と同程度のS/N比が得られ、精度のよい分析
処理を行うことができる。その上、ゲインアンプ及びA/
D変換器等は１回路系統でよいので、その分回路調整等
が容易であるばかりでなく、回路部品の節約となり、低
価格な光分析装置を得ることができる。(F) Effects of the Invention According to the present invention, the negative high voltage value applied to the photomultiplier tube in order to keep the input level to the CPU 1 constant is considered in consideration of the difference of each channel depending on the measurement object and the light source. Since the selection is made in a time-sharing manner in synchronization with the channel selection, even if the characteristics of each channel are different, an S / N ratio that is almost the same as that of a signal with a substantially constant level is always obtained, enabling accurate analysis. Processing can be performed. In addition, gain amplifier and A /
Since the D converter and the like need only be a single circuit system, not only the circuit adjustment and the like can be made easier, but also circuit components can be saved and a low-cost optical analyzer can be obtained.
【図面の簡単な説明】 第１図は、この発明の一実施例を示す光分析装置の回路
ブロック図、第２図は、同光分析装置の動作を説明する
ための光源のドライブ信号と光電子増倍管に時分割で印
加する電圧の変化例を示す図、第３図は、従来の光分析
装置の構成を示すブロック図である。 1:CPU、2:光源ドライバ、 3-1・3-2・3-3:光源、4:測定対象、 5:光電子増倍管、6:プリアンプ、 8:ゲインアンプ、9:A/D変換器、 10:負高圧電源 11:負高圧値選択回路。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit block diagram of an optical analyzer showing one embodiment of the present invention, and FIG. 2 is a drive signal of a light source and an optoelectronic device for explaining the operation of the optical analyzer. FIG. 3 is a diagram showing an example of a change in voltage applied to a multiplier in a time-division manner, and FIG. 3 is a block diagram showing a configuration of a conventional optical analyzer. 1: CPU, 2: light source driver, 3 -1 3 -2 3 -3: a light source, 4: measurement target 5: photomultiplier tube, 6: preamplifier, 8: gain amplifier, 9: A / D converter 10: Negative high voltage power supply 11: Negative high voltage value selection circuit.
Claims (1)
これらの光が測定対象を経て入光するのを検出する一個
の光電子増倍管を有し、この検出された信号を処理する
光分析装置において、 前記光電子増倍管に印加する電圧値を切り替え、各チャ
ンネルの特性相違にかかわらず出力信号をほぼ同レベル
にする負高圧値選択手段と、この負高圧値選択手段を前
記複数チャンネルの選択に同期して時分割で動作させる
手段とを備えたことを特徴とする光分析装置。1. Lights of a plurality of channels are lighted in a time division manner,
It has one photomultiplier tube for detecting that these lights enter through the object to be measured, and in an optical analyzer that processes the detected signal, a voltage value applied to the photomultiplier tube is switched. A negative high voltage value selecting means for making the output signals substantially the same level irrespective of the characteristic difference of each channel, and a means for operating the negative high voltage value selecting means in a time division manner in synchronization with the selection of the plurality of channels. An optical analyzer characterized by the above-mentioned.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2042261A JP3044380B2 (en) | 1990-02-22 | 1990-02-22 | Optical analyzer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2042261A JP3044380B2 (en) | 1990-02-22 | 1990-02-22 | Optical analyzer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03245040A JPH03245040A (en) | 1991-10-31 |
| JP3044380B2 true JP3044380B2 (en) | 2000-05-22 |
Family
ID=12631094
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2042261A Expired - Fee Related JP3044380B2 (en) | 1990-02-22 | 1990-02-22 | Optical analyzer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3044380B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6210212B2 (en) * | 2012-12-06 | 2017-10-11 | パナソニックＩｐマネジメント株式会社 | Light quantity measuring device and projection display device having the same |
-
1990
- 1990-02-22 JP JP2042261A patent/JP3044380B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03245040A (en) | 1991-10-31 |
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