JPS63269619A - Sensor for heated object - Google Patents
Sensor for heated objectInfo
- Publication number
- JPS63269619A JPS63269619A JP10372087A JP10372087A JPS63269619A JP S63269619 A JPS63269619 A JP S63269619A JP 10372087 A JP10372087 A JP 10372087A JP 10372087 A JP10372087 A JP 10372087A JP S63269619 A JPS63269619 A JP S63269619A
- Authority
- JP
- Japan
- Prior art keywords
- output
- circuit
- negative feedback
- operational amplifier
- feedback circuit
- 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
Links
- 230000007423 decrease Effects 0.000 abstract description 5
- 230000003321 amplification Effects 0.000 abstract description 2
- 238000003199 nucleic acid amplification method Methods 0.000 abstract description 2
- 230000003247 decreasing effect Effects 0.000 abstract 2
- 238000010586 diagram Methods 0.000 description 5
- 210000000988 bone and bone Anatomy 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 241001465754 Metazoa Species 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000036760 body temperature Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 229920006254 polymer film Polymers 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
Abstract
Description
【発明の詳細な説明】
（イ）産業上の利用分野
この発明は、サーモパイル素子（熱電素子）を使用し、
例えば人体の体温等を検知し、人体等熱体の到来を検出
する熱体検知器に関する。[Detailed description of the invention] (a) Industrial application field This invention uses a thermopile element (thermoelectric element),
For example, the present invention relates to a thermal body detector that detects the body temperature of a human body and detects the arrival of a thermal body such as a human body.
（ロ）従来の技術
従来より、人体検知器として、第３図に示すように、ケ
ース１内にサーモパイル素子２を収納したものが知られ
ている。サーモパイル素子２は、高分子フィルム３上に
、温接点りと冷接点Ｃからなる熱電対４を複数個直列接
続して（第４図参照）構成されるものであり、高分子フ
ィルム３は、ベース５．５によって支持され、直列接続
の両端は、電極６．６によりケース１外部に導出されて
いる。(B) Prior Art Conventionally, a human body detector in which a thermopile element 2 is housed in a case 1, as shown in FIG. 3, has been known. The thermopile element 2 is constructed by connecting a plurality of thermocouples 4 consisting of a hot junction and a cold junction C in series on a polymer film 3 (see FIG. 4). It is supported by a base 5.5, and both ends of the series connection are led out of the case 1 by electrodes 6.6.
温接点り部分は、温度の吸収を良くするために、白金黒
コーティング７が施され、冷接点Ｃ部分は、温度上昇を
防ぐために、ケース温度に固定されている。この人体検
知器では、人体が接近すると、人体より発する赤外光線
が、カットオンフィルタ（あるいはレンズ）８をを介し
て、サーモパイル素子２に集光され、各熱電対４に、熱
起電力を発生し、両電極６．６より導出される。そして
導出された電圧が所定のスレッショルドレベル以上とな
ると、人体検知信号を出力する。The hot junction portion is coated with a platinum black coating 7 to improve temperature absorption, and the cold junction C portion is fixed at the case temperature to prevent temperature rise. In this human body detector, when a human body approaches, infrared rays emitted from the human body are focused on the thermopile element 2 via a cut-on filter (or lens) 8, and a thermoelectromotive force is generated in each thermocouple 4. generated and led out from both electrodes 6.6. When the derived voltage exceeds a predetermined threshold level, a human body detection signal is output.
また、サーモパイル素子２で得られる熱電圧Ｖ、は、さ
らに感度を上げるために、第５図に示すように、演算増
幅器Ａ、及び抵抗Ｒｉ、 Ｒ，からなる増幅回路で増幅
している。Further, in order to further increase the sensitivity, the thermal voltage V obtained by the thermopile element 2 is amplified by an amplifier circuit consisting of an operational amplifier A and resistors Ri and R, as shown in FIG.
（ハ）発明の解決しようとする問題点
上記従来の人体検知器において、サーモパイル素子２は
、温接点りと冷接点Ｃの温度差による電圧発生素子であ
るため、例えば周囲温度が変化すれば発生電圧も変化す
る。また、レンズ性能により、焦点がわずかにずれたり
、焦点ボケが生じると、入光時の赤外光線は冷接点Ｃに
も影響が及ぶ。(C) Problems to be Solved by the Invention In the conventional human body detector described above, the thermopile element 2 is a voltage generating element that generates voltage due to the temperature difference between the hot junction C and the cold junction C. The voltage also changes. Furthermore, if the lens performance causes a slight shift in focus or out-of-focus, the infrared rays that enter the lens will also affect the cold junction C.
さらに、第５図の増幅回路を用いてゲインを上げると、
次の不具合が生じる。Furthermore, if the gain is increased using the amplifier circuit shown in Figure 5,
The following problem occurs.
■比較的長時間の入光が続いたとき、本来白金黒や温接
点りの温度上昇のみが望ましいのであるが、その温度が
冷接点Ｃにまで伝播したり、緩やかに冷接点Ｃの温度上
昇を生起したりするので、発生電圧が変化する。■When light continues to enter for a relatively long period of time, it is originally desirable for the temperature to rise only at the platinum black or hot junction, but the temperature may propagate to the cold junction C, or the temperature at the cold junction C may gradually rise. This causes the generated voltage to change.
■入光が取除かれると、温接点り部分は、熱慣性が小さ
くなるように構成されているので、即時に入光前の温度
に戻るが、上記■により、冷接点Ｃ部分の温度が高くな
っていると、この部分は、熱慣性が大きいので、すぐに
は温度が低下せず、結果として負電圧が発生し、出力Ｖ
。が安定しない。■When the incident light is removed, the hot junction part is configured to have a small thermal inertia, so it immediately returns to the temperature before the light entered, but due to the above ■, the temperature of the cold junction C part is If the temperature is high, this part has large thermal inertia, so the temperature does not drop immediately, and as a result, a negative voltage is generated and the output V
. is not stable.
■入力がなくても、周囲温度の変化に影響され、温接点
ｈ、冷接点Ｃとも、必ずしも同一温度で同時に変化しな
い。それゆえ、これを増幅した出力■ｏは、安定しない
。■Even if there is no input, it is affected by changes in ambient temperature, and the hot junction h and cold junction C do not necessarily change at the same temperature at the same time. Therefore, the amplified output ■o is not stable.
この発明は、上記の不具合を解消し、安定した増幅出力
を得ることのできる熱体検知器を提供することを目的と
している。An object of the present invention is to provide a thermal body detector that can eliminate the above-mentioned problems and obtain a stable amplified output.
（ニ）問題点を解決するための手段及び作用この発明の
熱体検知器は、赤外光線を受けて、電気信号を出力する
熱電素子と、この熱電素子の出力を増幅する増幅回路と
、前記熱電素子の入光時の出力ドリフトをキャンセルす
るため、前記増幅回路の出力の一部を増幅して、前記増
幅回路の入力に負帰還する負帰還回路とから構成されて
いる。(d) Means and operation for solving the problems The thermal body detector of the present invention includes a thermoelectric element that receives infrared rays and outputs an electric signal, an amplifier circuit that amplifies the output of the thermoelectric element, In order to cancel the output drift when light enters the thermoelectric element, it is comprised of a negative feedback circuit that amplifies a part of the output of the amplifier circuit and feeds it back negatively to the input of the amplifier circuit.
この熱体検知器では、例えば熱電素子の出力が上昇する
と、応じて増幅回路の出力も上昇し、その上昇分が負帰
還回路を経て、増幅回路入力に、その出力を下げるよう
に帰還する。逆に熱電素子の出力が下降すると、応じて
増幅回路の出力も下降し、その下降骨が負帰還増幅回路
を経て、増幅回路の入力にその出力を上げるように帰還
する。In this thermal body detector, for example, when the output of the thermoelectric element increases, the output of the amplifier circuit also increases accordingly, and the increased amount is fed back to the input of the amplifier circuit via the negative feedback circuit so as to lower the output. Conversely, when the output of the thermoelectric element decreases, the output of the amplifier circuit also decreases accordingly, and the descending bone passes through the negative feedback amplifier circuit and returns to the input of the amplifier circuit to increase its output.
そのため熱電素子のドリフト分は抑えられ、増幅回路の
出力は安定する。Therefore, the drift of the thermoelectric element is suppressed, and the output of the amplifier circuit is stabilized.
（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 The present invention will be explained in more detail with reference to Examples below.
第１図は、この発明の一実施例を示す人体検知器の回路
図である。同図において、サーモパイル素子２の出力Ｖ
、は、演算増幅器Ａ、の十入力端に加えられている。演
算増幅器Ａ１の一入力端と基準電位Ｇ間に抵抗Ｒ１が、
また−入力端と出力端間に抵抗Ｒ１が接続されて増幅回
路１０が構成されている。サーモパイル素子２の出力■
、は、増幅回路１０で増幅され、出力信号■。として導
出される。なお、サーモパイル素子２は、実際には、第
４図に示すように、複数の熱電対４．４が直列接続され
るものであるが、第１図では、簡略的に図示している。FIG. 1 is a circuit diagram of a human body detector showing an embodiment of the present invention. In the figure, the output V of the thermopile element 2
, are applied to the ten input terminals of operational amplifier A. A resistor R1 is connected between one input terminal of the operational amplifier A1 and the reference potential G,
Further, a resistor R1 is connected between the -input terminal and the output terminal to form an amplifier circuit 10. Output of thermopile element 2■
, is amplified by the amplifier circuit 10, and output signal ■. It is derived as Note that the thermopile element 2 is actually a plurality of thermocouples 4.4 connected in series, as shown in FIG. 4, but is shown in a simplified manner in FIG.
以上の回路構成は、第５図に示す従来回路と同じである
が、この実施例では、さらに一点鎖線で示す負帰還回路
１１を設けている。この負帰還回路１１は、演算増幅器
Ａ２を含み、この演算増幅器Ａ２の十入力端には、抵抗
Ｒ，を介して演算増幅器Ａ１の出力端が接続され、演算
増幅器Ａ２の一入力端と基準電位Ｇ間に抵抗Ｒ２が、ま
たこの演算増幅器Ａ２の一入力端と出力端間に抵抗Ｒ３
が接続され、さらにその出力端は、抵抗Ｒ４を介して演
算増幅器Ａ１の一入力端に接続されて構成されている。The above circuit configuration is the same as the conventional circuit shown in FIG. 5, but in this embodiment, a negative feedback circuit 11 shown by a dashed line is further provided. This negative feedback circuit 11 includes an operational amplifier A2, and an output end of the operational amplifier A1 is connected to an input end of the operational amplifier A2 via a resistor R, and one input end of the operational amplifier A2 is connected to a reference potential. A resistor R2 is connected between G and a resistor R3 is connected between one input terminal and the output terminal of this operational amplifier A2.
is connected, and its output terminal is further connected to one input terminal of the operational amplifier A1 via a resistor R4.
今、実施例人体検知器において、負帰還回路１１を設け
ない場合、つまり第５図の従来回路を想定すると、第６
図で示すように、サーモパイル素子２の出力Ｖ、がａｌ
で示すように、周囲温度の変化で変動すると、回路のゲ
インが大きいと、出力■。は、電源電圧まで振り切り（
第６図のＶ。のａ１参照）、また、入力光が長く続くと
温接点りと冷接点Ｃの温度差が小さくなり、サーモパイ
ル素子２の出力■、が徐々に減少する（第６図の■、の
ａ２参照）。そして入光がなくなると、温接点りより冷
接点Ｃの方が温度が高くなるため、■８は負となり（第
６図のｖｌのａ３参照）、出力Ｖｏも大きく、負となる
（第６図のｖｏのａ３参照）不具合が発生する。Now, assuming that the negative feedback circuit 11 is not provided in the human body detector of the embodiment, that is, assuming the conventional circuit shown in FIG.
As shown in the figure, the output V of the thermopile element 2 is al
As shown in , when the gain of the circuit is large, the output ■ changes due to changes in ambient temperature. is swung all the way to the power supply voltage (
V in Figure 6. Also, as the input light continues for a long time, the temperature difference between the hot junction C and the cold junction C becomes smaller, and the output ■ of the thermopile element 2 gradually decreases (see a2 of ■, in Figure 6). . When no light enters, the temperature of the cold junction C becomes higher than that of the hot junction, so ■8 becomes negative (see a3 of vl in Fig. 6), and the output Vo also becomes large and negative (the temperature of the cold junction C becomes higher than that of the hot junction). (See a3 of vo in the figure) A problem occurs.
これに対し負帰還回路１１を増設した状態で、作動させ
ると、例えばサーモパイル素子２の出力Ｖ、が上昇する
と、応じて出力Ｖ。が上昇するが出力■。の一部が演算
増幅器Ａ２で増幅され、演算増幅器Ａ２の増幅した出力
Ｖ。Ａが演算増幅器Ａ１の一入力端に加えられ、負帰還
回路の作用により、出力Ｖ。の上昇を抑える方向に作用
する。逆に、サーモパイル素子２の出力Ｖ、が下降する
と、応じて出力ｖ０が下降するが、この下降骨が負帰還
回路１１を経て、演算増幅器Ａ１の一入力端に帰還され
、出力ｖ０の下降を抑える方向に作用する。On the other hand, when the negative feedback circuit 11 is added and activated, for example, when the output V of the thermopile element 2 increases, the output V increases accordingly. ■ The output increases. A part of is amplified by the operational amplifier A2, and the amplified output V of the operational amplifier A2. A is applied to one input terminal of the operational amplifier A1, and due to the action of the negative feedback circuit, the output V. acts in the direction of suppressing the rise in Conversely, when the output V of the thermopile element 2 falls, the output v0 falls accordingly, but this falling bone is fed back to one input terminal of the operational amplifier A1 via the negative feedback circuit 11, causing the fall of the output v0. It acts in the direction of suppressing it.
そのため第２図に示すように、温接点ｈ、冷接点Ｃの変
化によりサーモパイル素子２の出力■、が変動しても（
第２図のｖ８のａ１参照）出力Ｖ。Therefore, as shown in Fig. 2, even if the output ■ of the thermopile element 2 changes due to changes in the hot junction h and cold junction C, (
(See a1 of v8 in FIG. 2) Output V.
は、常にある一定の値で安定となる（第２図のＶ。のａ
、参照）。また、入光が長く続いた後、入光が除去され
た場合、出力ｖ０は、やはり負となるが、負帰還作用の
為、出力Ｖ０は、早くＯｖに復帰する（第２図のＶ。の
ａ３参照）。is always stable at a certain value (a of V in Figure 2)
,reference). Furthermore, if the incident light is removed after the incident light has continued for a long time, the output v0 will still become negative, but due to the negative feedback effect, the output V0 will quickly return to Ov (V in FIG. 2). (See a3).
ところで、入光が有ったとき、温接点りの温度変化によ
り、演算増幅器Ａ１の入力Ｖ、が象、激に変化する。こ
の場合出力Ｖ。は、所定の電圧変化分が必要であると共
に、入光中は、その出力を維持しなければならない。こ
の場合は、抵抗Ｒ３に並列にコンデンサＣを接続して積
分回路を構成しておく。この積分回路の遅延時間分だけ
、出力■。に対して負帰還電圧■。えは、遅延されて、
演算増幅器Ａ、の一入力端に帰還される。そのため、こ
の遅延時間分だけ、出力■。の変化分は待たされること
になる。この遅延時間は、上記した環境温度の変化やサ
ーモパイル素子２の冷接点温度の変化に対応する時間に
とれば良い。By the way, when light is incident, the input V of the operational amplifier A1 changes drastically due to a temperature change at the hot junction. In this case the output V. requires a predetermined voltage change, and the output must be maintained during light input. In this case, a capacitor C is connected in parallel to the resistor R3 to form an integrating circuit. The output ■ corresponds to the delay time of this integration circuit. Negative feedback voltage for ■. Yes, it has been delayed,
It is fed back to one input terminal of operational amplifier A. Therefore, the output ■ corresponds to this delay time. You will have to wait for the change in . This delay time may be set to a time corresponding to the change in the environmental temperature or the cold junction temperature of the thermopile element 2 described above.
なお、上記実施例では、人体検知器を例に上げたが、こ
の発明はこれに限ることなく人体以外の動物、その他の
熱体の存在の有無を検知する場合にも広く適用できる。In the above embodiments, a human body detector is used as an example, but the present invention is not limited to this, and can be widely applied to detecting the presence or absence of animals other than human bodies and other heat bodies.
（へ）発明の効果
この発明によれば、熱電素子の出力を増幅回路で増幅し
て、出力を導出すると共に、この出力の一部を負帰還回
路を通して、増幅回路の入力側に帰還しているので、熱
電素子の出力が周囲温度、その他の変化によりドリフト
しても、これを打消し、安定な出力を導出するので、誤
検出の少ない熱体検知器を得ることができる。(f) Effects of the Invention According to this invention, the output of the thermoelectric element is amplified by the amplifier circuit to derive the output, and a part of this output is fed back to the input side of the amplifier circuit through the negative feedback circuit. Therefore, even if the output of the thermoelectric element drifts due to ambient temperature or other changes, this is canceled out and a stable output is derived, making it possible to obtain a hot body detector with fewer false detections.
第１図は、この発明の一実施例を示す人体検知器の回路
図、第２図は、同人体検知器の動作を説明するための波
形図、第３図は、人体検知器の概略断面図、第４図は、
同人体検知器のサーモパイル素子を説明するための平面
図、第５図は、従来の人体検知器の増幅回路を示す図で
ある、第６図は、同増幅回路の動作を説明するための波
形図。
２：サーモパイル素子。
１０；増幅回路。
１１：負帰還回路。Fig. 1 is a circuit diagram of a human body detector showing an embodiment of the present invention, Fig. 2 is a waveform diagram for explaining the operation of the human body detector, and Fig. 3 is a schematic cross section of the human body detector. Figure 4 is
FIG. 5 is a plan view for explaining the thermopile element of the human body detector. FIG. 5 is a diagram showing the amplifier circuit of the conventional human body detector. FIG. 6 is a waveform diagram for explaining the operation of the amplifier circuit. figure. 2: Thermopile element. 10; Amplification circuit. 11: Negative feedback circuit.
Claims (2)
と、この熱電素子の出力を増幅する増幅回路と、前記熱
電素子の入光時の出力ドリフトをキャンセルするため、
前記増幅回路の出力の一部を増幅して、前記増幅回路の
入力に負帰還する負帰還回路とを備えたことを特徴とす
る熱体検知器。(1) A thermoelectric element that receives infrared rays and outputs an electric signal, an amplifier circuit that amplifies the output of this thermoelectric element, and in order to cancel the output drift of the thermoelectric element when light enters,
A thermal body detector comprising: a negative feedback circuit that amplifies a part of the output of the amplifier circuit and provides negative feedback to the input of the amplifier circuit.
の積分回路を含むものである特許請求の範囲第１項記載
の熱体検知器。(2) The thermal body detector according to claim 1, wherein the negative feedback circuit includes an integrating circuit for obtaining a sufficient time delay.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10372087A JPS63269619A (en) | 1987-04-27 | 1987-04-27 | Sensor for heated object |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10372087A JPS63269619A (en) | 1987-04-27 | 1987-04-27 | Sensor for heated object |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63269619A true JPS63269619A (en) | 1988-11-07 |
Family
ID=14361522
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10372087A Pending JPS63269619A (en) | 1987-04-27 | 1987-04-27 | Sensor for heated object |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63269619A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009003424A (en) * | 2007-05-24 | 2009-01-08 | Ricoh Co Ltd | Image forming apparatus and electric appliance |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58131819A (en) * | 1982-02-01 | 1983-08-05 | Tsuuden:Kk | Automatic restoring type direct current amplifier |
-
1987
- 1987-04-27 JP JP10372087A patent/JPS63269619A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58131819A (en) * | 1982-02-01 | 1983-08-05 | Tsuuden:Kk | Automatic restoring type direct current amplifier |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009003424A (en) * | 2007-05-24 | 2009-01-08 | Ricoh Co Ltd | Image forming apparatus and electric appliance |
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