JPH0334243B2 - - Google Patents
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- Publication number
- JPH0334243B2 JPH0334243B2 JP56055996A JP5599681A JPH0334243B2 JP H0334243 B2 JPH0334243 B2 JP H0334243B2 JP 56055996 A JP56055996 A JP 56055996A JP 5599681 A JP5599681 A JP 5599681A JP H0334243 B2 JPH0334243 B2 JP H0334243B2
- Authority
- JP
- Japan
- Prior art keywords
- negative feedback
- signal
- detection
- output
- input terminal
- 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 - Lifetime
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Description
【発明の詳細な説明】
＜産業上の利用分野＞
本発明は、例えば、自動ドアの開閉や防犯警報
器の駆動に際し遠赤外線エネルギーの変化を検出
して人体等を検知する検知装置に関するものであ
る。[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a detection device that detects a human body, etc. by detecting changes in far-infrared energy when, for example, opening/closing an automatic door or driving a security alarm. be.
＜従来の技術＞
パツシブインフラレツド方式の人体検知装置
は、監視範囲内を人体が動くことによつて生じる
遠赤外線エネルギーの変化を検知して人体を検出
するものである。このような検知装置に用いられ
る信号増幅回路は、0.2〜６Hzの低域周波数を選
択増幅する周波数特性を有する。また、その増幅
率は、1000倍〜10000倍の低雑音で高増幅率を要
求される。<Prior Art> A passive infrared type human body detection device detects a human body by detecting changes in far-infrared energy caused by the movement of the human body within a monitoring range. A signal amplification circuit used in such a detection device has frequency characteristics that selectively amplify a low frequency range of 0.2 to 6 Hz. Further, the amplification factor is required to be 1000 times to 10000 times, with low noise and high amplification factor.
＜発明が解決しようとする課題＞
このような増幅回路は、前述のように0.2〜６
Hzの低域周波数のみを選択増幅するので、負帰還
増幅器に0.2Hz以下の低域を減衰させるためのコ
ンデンサを接続している。従つて、回路の時定数
が長いため、電源投入時に回路が安定するまでに
１分〜５分程度の時間を必要とし、電源投入後す
ぐに使用できない欠点がある。<Problem to be solved by the invention> As mentioned above, such an amplifier circuit has a
Since only the low frequency of Hz is selectively amplified, a capacitor is connected to the negative feedback amplifier to attenuate the low frequency of 0.2Hz or less. Therefore, since the time constant of the circuit is long, it takes about 1 to 5 minutes for the circuit to stabilize when the power is turned on, and there is a drawback that it cannot be used immediately after the power is turned on.
また、過大な入力があつた場合に、増幅回路
は、飽和や揺れ戻しによつて、遠赤外線エネルギ
ーの変化が無くなつた後においても恰も遠赤外線
エネルギーの変化が続いているが如く検知レベル
の信号を暫くの間出力し続ける。そのため、人数
計数や自動ドア開閉のための人体検知装置として
は不適当であつた。 In addition, when an excessive input is received, the amplifier circuit may change the detection level even after the change in far-infrared energy disappears due to saturation or swing back, as if the far-infrared energy continues to change. Continue outputting the signal for a while. Therefore, it was unsuitable as a human body detection device for counting people or opening/closing automatic doors.
本発明は、このような従来の問題点に鑑みてな
されたものであり、増幅回路における周波数特性
や増幅率等の本来の特性を損なうことなく、電源
投入時における安定状態に達するまでの時間の短
縮と過大入力時の誤動作の解消とを図つた検知装
置を提供することを技術的課題とするものであ
る。 The present invention has been made in view of these conventional problems, and it is possible to shorten the time required to reach a stable state when the power is turned on without impairing the original characteristics such as the frequency characteristics and amplification factor of the amplifier circuit. The technical problem is to provide a detection device that can be shortened and eliminate malfunctions caused by excessive input.
＜課題を解決するための手段＞
本発明は、上記した課題を達成するための技術
的課題として、検知装置を次のように構成した。<Means for Solving the Problems> In the present invention, as a technical problem for achieving the above-mentioned problems, a detection device is configured as follows.
即ち、入射する遠赤外線等の変化を電気信号に
変換して出力する赤外線検知素子からなる信号源
と、この信号源が非反転入力端子に接続された負
帰還増幅器と、この増幅器の出力端子と反転入力
端子との間に接続された負帰還抵抗と、前記反転
入力端子とアース間に直列接続された抵抗および
コンデンサと、前記負帰還増幅器の出力信号の信
号レベルが予め設定された闘値以上になつた時に
所定時間だけ検知信号を出力する信号処理回路と
を備え、前記負帰還抵抗、抵抗およびコンデンサ
により、前記負帰還増幅器の増幅率と低域周波数
のみを選択増幅する周波数特性とが設定されてな
る検知装置において、前記負帰還抵抗に並列接続
されるとともに前記検知信号の出力時のみ該検知
信号によりオン状態となつて前記負帰還抵抗を短
絡するスイツチング手段を備えたことを特徴とし
て構成されている。 That is, a signal source consisting of an infrared detection element that converts changes in incident far infrared rays etc. into electrical signals and outputs them, a negative feedback amplifier to which this signal source is connected to a non-inverting input terminal, and an output terminal of this amplifier. a negative feedback resistor connected between the inverting input terminal, a resistor and a capacitor connected in series between the inverting input terminal and the ground, and a signal level of the output signal of the negative feedback amplifier equal to or higher than a preset threshold value. a signal processing circuit that outputs a detection signal for a predetermined period of time when The detection device is characterized by comprising switching means connected in parallel to the negative feedback resistor and turned on by the detection signal to short-circuit the negative feedback resistor only when the detection signal is output. has been done.
＜作用＞
電源投入時、負帰還増幅器の非反転入力端子お
よび反転入力端子の各入力電圧は不平衡であるた
め、信号処理回路に闘値以上の信号レベルの信号
が入力され、この信号処理回路から所定時間だけ
出力される検知信号によりスイツチング手段がオ
ン状態となつて負帰還抵抗を短絡する。この時、
コンデンサは抵抗のみを通じて充電されるので、
その充電時間が大幅に短縮される。<Function> When the power is turned on, the input voltages of the non-inverting input terminal and the inverting input terminal of the negative feedback amplifier are unbalanced, so a signal with a signal level higher than the threshold value is input to the signal processing circuit, and this signal processing circuit The switching means is turned on by a detection signal outputted for a predetermined period of time, thereby short-circuiting the negative feedback resistor. At this time,
Since the capacitor is charged only through the resistor,
Its charging time is significantly reduced.
そして、所定時間が経過して信号処理回路から
検知信号が出力されなくなり、スイツチング手段
がオフされた時に負帰還増幅器の非反転入力端子
および反転入力端子の各入力電圧が平衡していな
ければ、上述と同様の動作を繰り返す。従つて電
源投入時から安定状態に達するまでの時間が大幅
に短縮される。 Then, if the input voltages of the non-inverting input terminal and the inverting input terminal of the negative feedback amplifier are not balanced when the detection signal is no longer output from the signal processing circuit after a predetermined period of time has elapsed and the switching means is turned off, the above-mentioned Repeat the same action. Therefore, the time from when the power is turned on until reaching a stable state is significantly shortened.
そして、安定状態に達した後は、スイツチング
手段が信号処理回路から検知信号が出力された時
以外はオフ状態を保持するので、増幅回路の周波
数特性および増幅率等の本来の特性を損なうこと
がない。 After reaching a stable state, the switching means remains off except when a detection signal is output from the signal processing circuit, so that the original characteristics such as the frequency characteristics and amplification factor of the amplifier circuit are not impaired. do not have.
また、過大入力時、信号処理回路への入力信号
が闘値の信号レベルを越えると同時に、信号処理
回路が所定時間の間検知信号を出力してスイツチ
ング手段をオンさせ、負帰還増幅器の増幅率を１
または略１とする。従つて、過大入力が無くなつ
た後の飽和や揺れ戻しに起因する負帰還増幅器か
ら信号処理回路への連続的な過大入力を防止でき
る。 Additionally, when the input signal to the signal processing circuit exceeds the threshold signal level when the input signal is excessive, the signal processing circuit outputs a detection signal for a predetermined period of time to turn on the switching means and adjust the amplification factor of the negative feedback amplifier. 1
Or approximately 1. Therefore, continuous excessive input from the negative feedback amplifier to the signal processing circuit due to saturation or swing back after the excessive input is eliminated can be prevented.
＜実施例＞
以下、本発明の一実施例を図を参照しながら詳
述する。<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings.
図において、信号源１は、赤外線検知素子また
は該検知素子と前置増幅器とからなる。差動入力
の負帰還増幅器２は、負帰還抵抗抵抗５、抵抗６
およびコンデンサ７により、増幅率と低域周波数
のみを選択増幅する周波数特性とを決定される。
尚、高域特性は本発明と係わりないので省略す
る。 In the figure, a signal source 1 consists of an infrared sensing element or an infrared sensing element and a preamplifier. A differential input negative feedback amplifier 2 includes a negative feedback resistor 5 and a resistor 6.
And the capacitor 7 determines the amplification factor and frequency characteristics for selectively amplifying only low frequencies.
Note that the high frequency characteristics are not related to the present invention and will therefore be omitted.
信号処理回路３は、正、負にかかわらず予め設
定された闘値以上の信号レベルの信号が負帰還増
幅器２から入力された場合に、例えば人体の検知
信号を約２秒間出力する。 The signal processing circuit 3 outputs, for example, a human body detection signal for about 2 seconds when a signal having a signal level equal to or higher than a preset threshold is input from the negative feedback amplifier 2, regardless of whether it is positive or negative.
スイツチング手段４は、信号処理回路３から出
力される検知信号によりオン状態となつて負帰還
抵抗５を短絡するもので、図示の電界効果トラン
ジスタの他に、トランジスタやアナログスイツチ
等が用いられる。 The switching means 4 is turned on by a detection signal output from the signal processing circuit 3 to short-circuit the negative feedback resistor 5, and uses a transistor, an analog switch, etc. in addition to the illustrated field effect transistor.
抵抗６およびコンデンサ７は、0.2Hz以下の低
域周波数を減衰させる低域特性を定めるためのも
のである。 The resistor 6 and capacitor 7 are used to define low-frequency characteristics that attenuate low-frequency frequencies of 0.2 Hz or less.
次に、前記実施例の作用について説明する。電
源投入時、負帰還増幅器２の非反転入力端子＋お
よび反転入力端子−の各入力電圧は不平衡である
ため、信号処理回路３に闘値以上の信号レベルの
信号が入力され、この信号処理回路３から２秒間
出力される検知信号によりスイツチング手段４が
オン状態となり、このオン状態のスイツチング手
段４により負帰還抵抗５が短絡される。この時、
コンデンサ７には抵抗６のみを通じて充電される
ので、その充電時間は大幅に短縮される。 Next, the operation of the above embodiment will be explained. When the power is turned on, the input voltages of the non-inverting input terminal + and the inverting input terminal - of the negative feedback amplifier 2 are unbalanced, so a signal with a signal level higher than the threshold value is input to the signal processing circuit 3, and this signal processing The switching means 4 is turned on by the detection signal output from the circuit 3 for two seconds, and the negative feedback resistor 5 is short-circuited by the switching means 4 in the on state. At this time,
Since the capacitor 7 is charged only through the resistor 6, the charging time is significantly shortened.
そして、約２秒経過後に信号処理回路３から検
知信号が出力されなくなつてスイツチング手段４
がオフされるが、そのオフ時に負帰還増幅器２の
非反転入力端子＋および反転入力端子−の各入力
電圧が平衡していなければ、上述と同様の動作を
繰り返す。いま、負帰還抵抗５に2.2MΩ、抵抗
６に10KΩの各抵抗値のものをそれぞれ用いた時
のコンデンサ７の充電抵抗は、従来装置では約
2.2MΩであるのに対し10KΩとなり、コンデンサ
７の充電時間、従つて電源投入時から安定状態に
達するまでの時間が大幅に短縮される。 Then, after approximately 2 seconds have elapsed, the signal processing circuit 3 no longer outputs the detection signal, and the switching means 4
is turned off, but if the input voltages at the non-inverting input terminal + and the inverting input terminal - of the negative feedback amplifier 2 are not balanced at the time of turning off, the same operation as described above is repeated. Now, when using negative feedback resistor 5 with a resistance value of 2.2MΩ and resistor 6 with a resistance value of 10KΩ, the charging resistance of capacitor 7 in the conventional device is approximately
It is 10KΩ compared to 2.2MΩ, and the charging time of the capacitor 7, and therefore the time from turning on the power until reaching a stable state, is significantly shortened.
そして、安定状態に達した後は、スイツチング
手段４が信号処理回路３から検知信号が出力され
た時以外はオフ状態を保持するので、負帰還増幅
器２、負帰還抵抗５、抵抗６およびコンデンサ７
からなる増幅回路の周波数特性および増幅率等の
本来の特性を損なうことがない。即ち、この種の
検知装置では、２秒の間出力する検知信号により
自動ドアを開放したり、或いは警報器を駆動して
いる期間は検知動作を行う必要がないので、その
期間においてスイツチング手段４により負帰還抵
抗５を短絡することによる周波数特性や増幅率の
変化は、当該検知装置にとつて何ら悪影響とはな
らず、検知信号の出力が無くなると同時にスイツ
チング手段４がオフ状態となるので、周波数特性
や増幅率等の本来の特性を損なうことがない。 After reaching a stable state, the switching means 4 remains off except when a detection signal is output from the signal processing circuit 3, so that the negative feedback amplifier 2, the negative feedback resistor 5, the resistor 6, and the capacitor 7
The original characteristics such as the frequency characteristics and amplification factor of the amplifier circuit made of the above are not impaired. That is, in this type of detection device, there is no need to perform a detection operation during a period when an automatic door is opened or an alarm is driven by a detection signal output for 2 seconds, so the switching means 4 does not operate during that period. Changes in the frequency characteristics and amplification factor caused by short-circuiting the negative feedback resistor 5 do not have any adverse effect on the detection device, and the switching means 4 turns off as soon as the detection signal is no longer output. Original characteristics such as frequency characteristics and amplification factors are not impaired.
また、過大入力時、信号処理回路３の入力信号
が闘値の信号レベルを越えると同時に、信号処理
回路３が約２秒の間検知信号を出力してスイツチ
ング手段４をオンさせ、負帰還増幅器２の増幅率
を１または略１とする。従つて、増幅回路の飽和
や揺れ戻しに起因する信号処理回路３への連続的
な過大入力を防止でき、負帰還増幅器２からの検
知レベルの信号の誤出力を短時間で解消できる。 In addition, at the time of excessive input, when the input signal of the signal processing circuit 3 exceeds the threshold signal level, the signal processing circuit 3 outputs a detection signal for about 2 seconds, turns on the switching means 4, and turns on the negative feedback amplifier. Let the amplification factor of 2 be 1 or approximately 1. Therefore, continuous excessive input to the signal processing circuit 3 due to saturation or swing back of the amplifier circuit can be prevented, and erroneous output of the detection level signal from the negative feedback amplifier 2 can be eliminated in a short time.
因みに、前記実施例の実測によると、電源投入
時から安定状態に達するまでの時間を従来装置の
約60秒から約６秒に、過大入力時の検知信号の誤
出力を従来装置の約６秒から約２秒にそれぞれ短
縮することができた。 Incidentally, according to actual measurements in the above example, the time from power-on to reaching a stable state was reduced from about 60 seconds in the conventional device to about 6 seconds, and the time required for false output of a detection signal at the time of excessive input was reduced to about 6 seconds in the conventional device. We were able to shorten each time from 1 to 2 seconds.
尚、本発明は前記実施例に限定されるものでは
なく、例えば、信号処理回路３の検知信号タイマ
ー時間とスイツチング手段４の制御信号タイマー
時間とが異なつたり、２段以上の増幅器のうちの
１段のみ或いは全段にスイツチング手段を接続し
ても、前記実施例と同様の効果を得ることができ
る。 Note that the present invention is not limited to the above-mentioned embodiments, and for example, the detection signal timer time of the signal processing circuit 3 and the control signal timer time of the switching means 4 may be different, or Even if switching means is connected to only one stage or all stages, the same effects as in the above embodiment can be obtained.
＜発明の効果＞
以上のように本発明の検知装置によると、負帰
還増幅器の負帰還抵抗を、信号処理回路から出力
する検知信号でオン状態となるスイツチング手段
により短絡するようにしたので、電源投入時にお
ける安定状態に達するまでの時間の短縮と、過大
入力時の悪影響の除去とを達成することができ
る。<Effects of the Invention> As described above, according to the detection device of the present invention, the negative feedback resistor of the negative feedback amplifier is short-circuited by the switching means that is turned on by the detection signal output from the signal processing circuit. It is possible to shorten the time it takes to reach a stable state at the time of input, and to eliminate the negative effects of excessive input.
図は本発明の一実施例の要部のブロツク構成図
である。
１……信号源、２……負帰還増幅器、３……信
号処理回路、４……スイツチング手段、５……負
帰還抵抗、６……抵抗、７……コンデンサ、＋…
…非反転入力端子、−……反転入力端子。
The figure is a block diagram of essential parts of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Signal source, 2... Negative feedback amplifier, 3... Signal processing circuit, 4... Switching means, 5... Negative feedback resistor, 6... Resistor, 7... Capacitor, +...
...Non-inverting input terminal, -...Inverting input terminal.
Claims (1)
して出力する赤外線検知素子からなる信号源と、
この信号源が非反転入力端子に接続された負帰還
増幅器と、この増幅器の出力端子と反転入力端子
との間に接続された負帰還抵抗と、前記反転入力
端子とアース間に直列接続された抵抗およびコン
デンサと、前記負帰還増幅器の出力信号の信号レ
ベルが予め設定された闘値以上になつた時に所定
時間だけ検知信号を出力する信号処理回路とを備
え、前記負帰還抵抗、抵抗およびコンデンサによ
り、前記負帰還増幅器の増幅率と低域周波数のみ
を選択増幅する周波数特性とが設定されてなる検
知装置において、前記負帰還抵抗に並列接続され
るとともに前記検知信号の出力時のみ該検知信号
によりオン状態となつて前記負帰還抵抗を短絡す
るスイツチング手段を備えてなることを特徴とす
る検知装置。1. A signal source consisting of an infrared detection element that converts changes in incident far-infrared rays etc. into electrical signals and outputs them;
The signal source includes a negative feedback amplifier connected to a non-inverting input terminal, a negative feedback resistor connected between the output terminal of the amplifier and the inverting input terminal, and a negative feedback resistor connected in series between the inverting input terminal and ground. A signal processing circuit that outputs a detection signal for a predetermined period of time when the signal level of the output signal of the negative feedback amplifier exceeds a preset threshold; In the detection device in which the amplification factor of the negative feedback amplifier and frequency characteristics for selectively amplifying only low frequencies are set, the detection device is connected in parallel to the negative feedback resistor and the detection signal is output only when the detection signal is output. 1. A detection device comprising switching means that is brought into an on state and short-circuits the negative feedback resistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5599681A JPS57170607A (en) | 1981-04-13 | 1981-04-13 | Amplifying circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5599681A JPS57170607A (en) | 1981-04-13 | 1981-04-13 | Amplifying circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57170607A JPS57170607A (en) | 1982-10-20 |
| JPH0334243B2 true JPH0334243B2 (en) | 1991-05-22 |
Family
ID=13014685
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5599681A Granted JPS57170607A (en) | 1981-04-13 | 1981-04-13 | Amplifying circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57170607A (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60119121A (en) * | 1983-11-30 | 1985-06-26 | Mitsubishi Electric Corp | Amplifier circuit for waveform shaping |
| JPS60137392U (en) * | 1984-02-23 | 1985-09-11 | 松下電工株式会社 | Amplification circuit for hot wire detector |
| JPS60189870U (en) * | 1984-05-25 | 1985-12-16 | 松下電工株式会社 | Power-on delay circuit for reflective infrared detector |
| US5291151A (en) * | 1991-01-19 | 1994-03-01 | Canon Kabushiki Kaisha | Sensor amplifier |
| US5703529A (en) * | 1995-10-13 | 1997-12-30 | National Semiconductor Corporation | Amplifier circuit with reduced DC power related transients |
| US5642074A (en) * | 1995-10-13 | 1997-06-24 | National Semiconductor Corporation | Amplifier circuit with reduced turn-on and turn-off transients |
| US5939938A (en) * | 1995-10-13 | 1999-08-17 | National Semiconductor Corporation | Amplifier circuit with reduced DC power related turn-on and turn-off transients |
| JP4661253B2 (en) * | 2005-02-10 | 2011-03-30 | 富士ゼロックス株式会社 | Image forming apparatus |
| JP2016057254A (en) * | 2014-09-12 | 2016-04-21 | パナソニックＩｐマネジメント株式会社 | Infrared detector |
| US12117346B2 (en) * | 2021-05-28 | 2024-10-15 | Lutron Technology Company Llc | Startup procedure for a passive infrared sensing circuit |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5483743A (en) * | 1977-12-16 | 1979-07-04 | Nec Corp | Alternating current amplifier |
-
1981
- 1981-04-13 JP JP5599681A patent/JPS57170607A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57170607A (en) | 1982-10-20 |
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