JP2949286B2 - Dimmable carbon dioxide concentration sensor - Google Patents
Dimmable carbon dioxide concentration sensorInfo
- Publication number
- JP2949286B2 JP2949286B2 JP62212455A JP21245587A JP2949286B2 JP 2949286 B2 JP2949286 B2 JP 2949286B2 JP 62212455 A JP62212455 A JP 62212455A JP 21245587 A JP21245587 A JP 21245587A JP 2949286 B2 JP2949286 B2 JP 2949286B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- carbon dioxide
- dioxide concentration
- infrared
- level
- 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
Links
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
- Fire-Detection Mechanisms (AREA)
Description
【発明の詳細な説明】
〔従来分野〕
本発明は、投光器に受光器を対向させて設置して構成
される減光式煙感知器を応用した減光式二酸化炭素濃度
感知器に関する。
〔技術背景〕
この種の減光式煙感知器は、投光器より900〜1000nm
の波長域の近赤外線を発光し、受光器が受ける光量の変
化を検知して監視エリアに煙が存在することを報知する
システムなどに使用されており、その使用目的は火災の
発見を目的としたものにしか使用されていないのが実情
であり、室内の空気の汚染度を検知するためには、別の
環境センサーを設けるなどしている。このため、室内の
空気の汚染度と火災の発生を知るためには、２つのセン
サーを設けなければならず、システムの構成を複雑にし
ている。
〔発明の目的〕
本発明は、上記の事情に鑑みてなされたもので、火災
の発見と、室内空気の汚染度の双方の監視が可能とされ
た減光式二酸化炭素濃度感知器を提供することを目的と
している。
〔発明の開示〕
上記目的を達成するために提案される本発明は、発光
素子を有し、二酸化炭素を吸収する波長域の赤外線を発
光する発光部と、この発光部より発光され焦電型赤外線
検知素子により受光される赤外線を変調する変調手段
と、上記発光部に対向して配置され、上記発光部より発
光される赤外線を上記赤外線のみを透過する光フィルタ
を介して受光する上記焦電型赤外線検知素子と、上記焦
電型赤外線検知素子からの検知信号を所定レベルに増幅
する信号増幅処理回路と、監視エリアとなる上記発光部
と上記焦電型赤外線検知素子との間の空間内の二酸化炭
素濃度に応じて上記信号増幅処理回路の出力が所定の基
準レベルまで低下したときに異常信号を出力するレベル
判別回路とを備え、上記基準レベルを火災感知レベルま
たは空気汚染感知レベルに選択的に設定するようにした
ことを特徴としている。
〔実施例〕
以下に、添付図を参照して本発明の実施例を説明す
る。
本発明の感知器は、図に見るように、発光部Ｉと受光
処理部IIの２つの部分より構成されており、発光部Ｉよ
り発光された赤外線が監視エリアを通過した後に受光処
理部IIに受光される光量の変化を検知することにより監
視エリア内における火災の発生と空気の汚染度を検知す
ることを基本の原理とする。発光部Ｉより発光される赤
外線には二酸化炭素を吸収する波長域のものが使用され
ており、また、受光処理部IIの検知素子として焦電型赤
外線検知素子を使用している。焦電型赤外線検知素子を
用いた場合、受光処理部IIによって受光される赤外線は
連続受光ではなく、間欠的に受光されるようにする必要
があり、このため変調手段を備えた構成とされている。
第１図は、本発明の第一の実施例の基本構成を示した
ものである。
発光部Ｉは、発光素子１と、二酸化炭素を吸収する作
用のある4.3〜4.4μｍの波長域の赤外線のみを透過する
光学フィルタ６及び発光素子１の発光を間欠的に行うた
めの発振駆動回路2Aを有して構成されている。
受光処理部IIは、発光部Ｉから発光された赤外線のみ
を透過する光学フィルタ６を設けた焦電型赤外線検知素
子３と、この赤外線検知素子３の検知出力を増幅し処理
する信号増幅処理回路４と、この信号増幅処理回路４に
よって処理された信号レベルを基準レベルと比較判別
し、信号レベルが基準レベルより低下したときに異常信
号を出力するレベル判別回路５を有した構成となってい
る。そして、この実施例では、発光部Ｉの発光が間欠駆
動にされているため、信号増幅処理回路４も発振駆動回
路2Aに同期して作動される構成とされている。
このような第一の実施例の特徴は、発光部Ｉの発光素
子１の駆動を間欠にして赤外線を変調している点にあ
り、したがって発光部Ｉの発振駆動回路2Aが変調手段を
構成しており、その発振間隔は焦電型赤外線検知素子３
の特性に応じて１〜10Hz程度に設定されている。
このような構成の本発明の動作を説明すると、受光処
理部IIによって受光される赤外線の受光量は監視エリア
７内の二酸化炭素濃度が増大するにつれて減少するの
で、焦電型赤外線検知素子３の検知信号レベルは、二酸
化炭素の濃度が増大すれば逆に減少することになる。ま
た、この信号は、焦電型赤外線検知素子３の特性から受
光赤外線の変化分しか検知できず、微分出力となるの
で、信号増幅処理回路４において所定レベルまで増幅さ
れた後、ピークホールドや積分などの方法で処理出力を
得る。かくして得られた処理出力は、監視エリア７内の
二酸化炭素濃度に応じて低下するので、レベル判別回路
５において基準レベルと比較判別され、基準レベルより
低下すれば異常信号を出力する。
なお、レベル判別回路５の基準レベルは、感知器の使
用目的、例えば火災感知、空気汚染感知などに応じて最
適値に設定されることはいうまでもない。
第３図（ａ）〜（ｄ）は、二酸化炭素濃度に応じて変
化する受光処理部IIの以上の動作を説明するものであ
る。
第２図は、本発明の第二の実施例を示している。
この実施例の特徴は、機械的な光学チョッパ2Bにより
赤外線の変調手段を構成した点にあり、焦電型赤外線検
知素子３の特性に合わせて１〜10Hzでチョッピングして
いる。発光部Ｉにおける発光素子１の発光は駆動回路1a
により連続駆動とされているが、その他の構成は第一の
実施例と同様なので対応する部分に同一符号を付して説
明を省略する。
〔発明の効果〕
本発明の減光式二酸化炭素濃度感知機によれば、基準
レベルを火災検知、空気汚染検知の目的に応じて予め設
定しておけば、監視エリア内の二酸化炭素濃度の変化を
検知することで、火災の発見や、人の存在による室内空
気汚染度を検知することができるので、使用目的に応じ
て、火災センサー、環境センサーとして使用できる。
また、受動型の焦電型赤外線検知素子を用いているの
で消費電力も低い焦電力タイプの減光式二酸化炭素濃度
感知器が得られる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimming type carbon dioxide concentration sensor to which a dimming type smoke detector configured by installing a light receiving device facing a light emitting device is applied. [Technical background] This type of dim smoke detector is 900-1000nm
It is used in systems that emit near-infrared light in the wavelength range of, and detects changes in the amount of light received by the light receiver to notify the presence of smoke in the monitoring area.The purpose of this system is to detect fires. In fact, it is used only for the ones that have been used, and other environmental sensors are installed to detect the degree of indoor air pollution. For this reason, two sensors must be provided in order to know the degree of pollution of the indoor air and the occurrence of a fire, which complicates the configuration of the system. [Object of the Invention] The present invention has been made in view of the above circumstances, and provides a dimmable carbon dioxide concentration sensor capable of detecting both a fire and monitoring the degree of indoor air pollution. It is intended to be. DISCLOSURE OF THE INVENTION The present invention proposed to achieve the above object has a light-emitting element that has a light-emitting element, emits infrared light in a wavelength range that absorbs carbon dioxide, and a pyroelectric light-emitting element that emits light from the light-emitting element. A modulating means for modulating the infrared light received by the infrared detecting element; and a pyroelectric element disposed opposite to the light emitting portion and receiving the infrared light emitted from the light emitting portion through an optical filter that transmits only the infrared light. Type infrared detecting element, a signal amplification processing circuit for amplifying a detection signal from the pyroelectric type infrared detecting element to a predetermined level, and a space between the light emitting portion and the pyroelectric type infrared detecting element serving as a monitoring area. A level discriminating circuit that outputs an abnormal signal when the output of the signal amplification processing circuit drops to a predetermined reference level in accordance with the carbon dioxide concentration of the fuel cell. It is characterized in that the air pollution detection level is selectively set. Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings. As shown in the figure, the sensor of the present invention is composed of two parts, a light emitting unit I and a light receiving processing unit II, and after the infrared light emitted from the light emitting unit I passes through the monitoring area, the light receiving processing unit II. The basic principle is to detect the occurrence of a fire in the monitoring area and the degree of air pollution by detecting a change in the amount of light received on the monitor. The infrared rays emitted from the light emitting section I are those in a wavelength range that absorbs carbon dioxide, and a pyroelectric infrared detecting element is used as a detecting element of the light receiving processing section II. In the case of using a pyroelectric infrared detecting element, it is necessary that the infrared light received by the light receiving processing unit II is not continuously received, but intermittently received. I have. FIG. 1 shows the basic configuration of the first embodiment of the present invention. The light emitting section I includes a light emitting element 1, an optical filter 6 having a function of absorbing carbon dioxide and transmitting only infrared rays in a wavelength range of 4.3 to 4.4 μm, and an oscillation driving circuit for intermittently emitting light from the light emitting element 1. It has 2A. The light receiving processing unit II includes a pyroelectric infrared detecting element 3 provided with an optical filter 6 that transmits only infrared light emitted from the light emitting unit I, and a signal amplification processing circuit that amplifies and processes a detection output of the infrared detecting element 3. 4 and a level discriminating circuit 5 for comparing and discriminating the signal level processed by the signal amplification processing circuit 4 with a reference level, and outputting an abnormal signal when the signal level falls below the reference level. . In this embodiment, since the light emission of the light emitting section I is intermittently driven, the signal amplification processing circuit 4 is also operated in synchronization with the oscillation drive circuit 2A. The feature of the first embodiment is that the driving of the light emitting element 1 of the light emitting unit I intermittently modulates the infrared light. Therefore, the oscillation driving circuit 2A of the light emitting unit I constitutes a modulation means. The oscillation interval of the pyroelectric infrared detecting element 3
Is set to about 1 to 10 Hz in accordance with the characteristics of The operation of the present invention having such a configuration will be described. The amount of infrared light received by the light receiving processing unit II decreases as the concentration of carbon dioxide in the monitoring area 7 increases. The detection signal level will conversely decrease as the concentration of carbon dioxide increases. Further, this signal can be detected only by the change of the received infrared ray from the characteristics of the pyroelectric infrared detecting element 3 and becomes a differential output. Therefore, after being amplified to a predetermined level in the signal amplification processing circuit 4, the signal is peak-held or integrated. The processing output is obtained by such a method. Since the processing output thus obtained decreases in accordance with the carbon dioxide concentration in the monitoring area 7, the processing output is compared and determined with the reference level in the level determination circuit 5, and if the processing output is lower than the reference level, an abnormal signal is output. It goes without saying that the reference level of the level discriminating circuit 5 is set to an optimum value according to the purpose of use of the sensor, for example, fire detection, air pollution detection, and the like. FIGS. 3A to 3D illustrate the above-described operation of the light receiving processing unit II that changes according to the carbon dioxide concentration. FIG. 2 shows a second embodiment of the present invention. This embodiment is characterized in that a mechanical optical chopper 2B constitutes an infrared modulator, and chopping is performed at 1 to 10 Hz in accordance with the characteristics of the pyroelectric infrared detecting element 3. The light emission of the light emitting element 1 in the light emitting unit I is performed by the driving circuit 1a.
, The other components are the same as those of the first embodiment, and the corresponding parts are denoted by the same reference numerals and description thereof is omitted. [Effects of the Invention] According to the dimming type carbon dioxide concentration sensor of the present invention, if the reference level is set in advance according to the purpose of fire detection and air pollution detection, the change of the carbon dioxide concentration in the monitoring area can be changed. By detecting a fire, it is possible to detect a fire or to detect the degree of indoor air pollution due to the presence of a person, so that it can be used as a fire sensor or an environmental sensor according to the purpose of use. In addition, since a passive pyroelectric infrared detecting element is used, a dimming type carbon dioxide concentration sensor of a pyroelectric power type having low power consumption can be obtained.
【図面の簡単な説明】
第１図は本発明の第一の実施例の基本構成を示す図、第
２図は第二の実施例の基本構成を示す図、第３図は本発
明の動作を説明するタイムチャートである。
（符号の説明）
Ｉ……発光部
１……発光素子
2A……発振駆動回路（変調手段）
1a……駆動回路
II……受光処理部
2B……光学チョッパ（変調手段）
３……焦電型赤外線検知素子
４……信号増幅処理回路
５……レベル判別回路
６……光学フィルタ
７……監視エリアBRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a basic configuration of a first embodiment of the present invention, FIG. 2 is a diagram showing a basic configuration of a second embodiment, and FIG. 5 is a time chart for explaining FIG. (Explanation of symbols) I ... Light-emitting section 1 ... Light-emitting element 2A ... Oscillation drive circuit (modulation means) 1a ... Drive circuit II ... Light-receiving processing section 2B ... Optical chopper (modulation means) 3 ... Pyroelectric Type infrared detecting element 4 signal amplification processing circuit 5 level discriminating circuit 6 optical filter 7 monitoring area
Claims (1)
外線を発光する発光部と、この発光部より発光され焦電
型赤外線検知素子により受光される赤外線を変調する変
調手段と、上記発光部に対向して配置され、上記発光部
より発光される赤外線を上記赤外線のみを透過する光フ
ィルタを介して受光する上記焦電型赤外線検知素子と、
上記焦電型赤外線検知素子からの検知信号を所定レベル
に増幅する信号増幅処理回路と、監視エリアとなる上記
発光部と上記焦電型赤外線検知素子との間の空間内の二
酸化炭素濃度に応じて上記信号増幅処理回路の出力が所
定の基準レベルまで低下したときに異常信号を出力する
レベル判別回路とを備え、 上記基準レベルを火災感知レベルまたは空気汚染感知レ
ベルに選択的に設定するようにした減光式二酸化炭素濃
度感知器。 ２．上記変調手段が、上記発光素子を間欠駆動する構成
とされた特許請求の範囲第（１）項記載の減光式二酸化
炭素濃度感知器。 ３．上記変調手段が、光学チョッパにより上記発光素子
より発光された赤外線が上記受光素子に間欠的に受光さ
れる構成とした特許請求の範囲第（１）項記載の減光式
二酸化炭素濃度感知器。(57) [Claims] A light-emitting element having a light-emitting element and emitting infrared light in a wavelength range that absorbs carbon dioxide, a modulating means for modulating infrared light emitted from the light-emitting part and received by a pyroelectric infrared detecting element, and The pyroelectric infrared detecting element that is disposed to face and receives infrared light emitted from the light emitting unit through an optical filter that transmits only the infrared light,
A signal amplification processing circuit for amplifying a detection signal from the pyroelectric infrared detection element to a predetermined level, and a carbon dioxide concentration in a space between the light emitting section and the pyroelectric infrared detection element that are to be monitored areas. A level discrimination circuit that outputs an abnormal signal when the output of the signal amplification processing circuit drops to a predetermined reference level, wherein the reference level is selectively set to a fire detection level or an air pollution detection level. Dimmable carbon dioxide concentration sensor. 2. 2. A dimming type carbon dioxide concentration sensor according to claim 1, wherein said modulating means drives the light emitting element intermittently. 3. 2. The dimming type carbon dioxide concentration sensor according to claim 1, wherein said modulation means is configured to intermittently receive infrared light emitted from said light emitting element by an optical chopper to said light receiving element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62212455A JP2949286B2 (en) | 1987-08-26 | 1987-08-26 | Dimmable carbon dioxide concentration sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62212455A JP2949286B2 (en) | 1987-08-26 | 1987-08-26 | Dimmable carbon dioxide concentration sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6455699A JPS6455699A (en) | 1989-03-02 |
| JP2949286B2 true JP2949286B2 (en) | 1999-09-13 |
Family
ID=16622908
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62212455A Expired - Lifetime JP2949286B2 (en) | 1987-08-26 | 1987-08-26 | Dimmable carbon dioxide concentration sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2949286B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102762965A (en) * | 2010-02-16 | 2012-10-31 | 日本电气株式会社 | Infrared ray sensor, infrared ray detection device, and electronic apparatus |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5053754A (en) * | 1990-04-02 | 1991-10-01 | Gaztech Corporation | Simple fire detector |
| DE102015003019A1 (en) * | 2015-03-06 | 2016-09-08 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Method and device for the optical detection of movement in a biological sample with spatial extent |
| CN112594786A (en) * | 2020-12-16 | 2021-04-02 | 青岛海尔空调器有限总公司 | Air conditioner and control method and system of air conditioner |
| CN113161253B (en) * | 2021-01-25 | 2022-11-22 | 青岛华芯晶电科技有限公司 | Wafer surface impurity pollution degree detection system |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4896098A (en) * | 1972-03-21 | 1973-12-08 | ||
| JPS5732842U (en) * | 1980-07-31 | 1982-02-20 | ||
| JPS58218639A (en) * | 1982-06-15 | 1983-12-19 | Tetsuji Matsui | Open light path system infrared-ray gas analyzer |
| JPS5934252A (en) * | 1982-08-23 | 1984-02-24 | 有限会社友信開発 | Low friction artificial joint |
-
1987
- 1987-08-26 JP JP62212455A patent/JP2949286B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102762965A (en) * | 2010-02-16 | 2012-10-31 | 日本电气株式会社 | Infrared ray sensor, infrared ray detection device, and electronic apparatus |
| US8921791B2 (en) | 2010-02-16 | 2014-12-30 | Nec Corporation | Infrared ray sensor, infrared ray detection device, and electronic apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6455699A (en) | 1989-03-02 |
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