JPH11213263A - Light scattering type particle detecting sensor - Google Patents
Light scattering type particle detecting sensorInfo
- Publication number
- JPH11213263A JPH11213263A JP10018520A JP1852098A JPH11213263A JP H11213263 A JPH11213263 A JP H11213263A JP 10018520 A JP10018520 A JP 10018520A JP 1852098 A JP1852098 A JP 1852098A JP H11213263 A JPH11213263 A JP H11213263A
- Authority
- JP
- Japan
- Prior art keywords
- light
- light receiving
- receiving element
- area
- type particle
- 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
- 239000002245 particle Substances 0.000 title claims abstract description 37
- 238000000149 argon plasma sintering Methods 0.000 title claims abstract description 19
- 230000003287 optical effect Effects 0.000 claims abstract description 49
- 238000001514 detection method Methods 0.000 claims abstract description 28
- 239000000779 smoke Substances 0.000 claims abstract description 11
- 239000000428 dust Substances 0.000 claims description 10
- 230000035945 sensitivity Effects 0.000 abstract description 3
- 239000000843 powder Substances 0.000 abstract 1
- 230000002238 attenuated effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 235000019504 cigarettes Nutrition 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
Landscapes
- Filtering Of Dispersed Particles In Gases (AREA)
- Fire-Detection Mechanisms (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、空気清浄機等にお
いて粉塵や煙草の煙を検知したり、あるいは光電式煙感
知器等において煙粒子を検知したりするために用いられ
る光散乱式粒子検知センサに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-scattering type particle detector used for detecting dust or smoke from a cigarette in an air purifier or the like, or for detecting smoke particles in a photoelectric smoke detector or the like. It concerns a sensor.
【０００２】[0002]
【従来の技術】従来の光散乱式粒子検知センサは、それ
ぞれの光軸を交差させる形で光学室内に配置された投光
素子と受光素子とを備えている。そして、投光素子の投
光領域と受光素子の受光領域とが重合する領域である検
知領域における煙や粉塵等の粒子による投光素子からの
光の散乱光を受光素子にて受光することにより粒子を検
出するものである。光学室を形成するケースは、煙や粉
塵等の粒子が流入しやすいが外光は入りにくいラビリン
ス形状を有している。2. Description of the Related Art A conventional light scattering type particle detection sensor has a light projecting element and a light receiving element arranged in an optical chamber so that respective optical axes cross each other. Then, the light receiving element receives the scattered light of light from the light emitting element due to particles such as smoke and dust in the detection area where the light emitting area of the light emitting element and the light receiving area of the light receiving element overlap. It detects particles. The case forming the optical chamber has a labyrinth shape in which particles such as smoke and dust easily flow in, but hardly allow external light to enter.
【０００３】[0003]
【発明が解決しようとする課題】この種の光散乱式粒子
検知センサでは、小型化を図ると、投光素子からの光が
光学室の内壁によって反射され、その光が迷光となって
受光素子に達し、光学的なＳ／Ｎ比が悪化するという問
題点を有している。そこで、小型化・高感度化という相
反する課題を解決するために様々な手法が提案されてい
る。In this type of light scattering type particle detection sensor, when the size is reduced, the light from the light projecting element is reflected by the inner wall of the optical chamber, and the light becomes stray light and becomes light receiving element. , And the optical S / N ratio deteriorates. Therefore, various methods have been proposed to solve the contradictory problems of miniaturization and high sensitivity.
【０００４】その一つである特開平４−１６０６９７号
公報で提案した光散乱式粒子検知センサでは、投光素子
からの光が光学室の内壁によって反射され、その光が迷
光となって受光素子に達し、光学的なＳ／Ｎ比が悪化す
るのを防止するために、光学室内に遮光壁を設けてい
る。この遮光壁により、投光素子からの迷光が受光素子
に入射されるまでに、遮光壁や光学室内の内壁等に複数
回反射させることが可能になるため、反射による光の減
衰を利用して投光パワーに対する迷光パワーを下げるこ
とが可能になるといったものである。[0004] In the light scattering type particle detection sensor proposed in Japanese Patent Application Laid-Open No. Hei 4-160697, light from a light projecting element is reflected by the inner wall of an optical chamber, and the light becomes stray light to form a light receiving element. To prevent the optical S / N ratio from deteriorating, a light shielding wall is provided in the optical chamber. The light-shielding wall allows the stray light from the light-emitting element to be reflected a plurality of times on the light-shielding wall or the inner wall of the optical room before being incident on the light-receiving element. It is possible to reduce the stray light power with respect to the projection power.
【０００５】本発明は、上記の問題点に鑑みて成された
ものであり、その目的とするところは、小型化しても更
に高感度化を図ることができる光散乱式粒子検知センサ
を提供することにある。The present invention has been made in view of the above problems, and an object of the present invention is to provide a light scattering type particle detection sensor which can achieve higher sensitivity even if it is downsized. It is in.
【０００６】[0006]
【課題を解決するための手段】請求項１記載の発明は、
それぞれ光軸を交差させる形で光学室内に配置された投
光素子と受光素子とを備え、投光素子の投光領域と受光
素子の受光領域とが重合する領域である検知領域におけ
る煙や粉塵等の粒子による投光素子からの散乱光を受光
素子にて受光することにより粒子を検知する光散乱式粒
子検知センサにおいて、受光素子の受光領域を捕捉する
開口を有し、奥に進むにつれて筒の径が徐々に小さくな
る構造を有した光トラップを受光素子と対向する位置に
設けたことを特徴とするものである。According to the first aspect of the present invention,
A light-emitting element and a light-receiving element arranged in an optical chamber so that the optical axes cross each other, and smoke and dust in a detection area where a light-emitting area of the light-emitting element and a light-receiving area of the light-receiving element overlap. In a light scattering type particle detection sensor that detects particles by receiving scattered light from a light emitting element due to particles such as a light receiving element with a light receiving element, it has an opening to capture the light receiving area of the light receiving element, and An optical trap having a structure in which the diameter of the light trap gradually decreases is provided at a position facing the light receiving element.
【０００７】[0007]
【発明の実施の形態】以下、本発明の一実施の形態につ
いて図１及び図２に基づき詳細に説明する。図１は光散
乱式粒子検知センサの縦断面図である。図２は光散乱式
粒子検知センサの分解斜視図である。DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a longitudinal sectional view of the light scattering type particle detection sensor. FIG. 2 is an exploded perspective view of the light scattering type particle detection sensor.
【０００８】本実施の形態の光散乱式粒子検知センサで
は、中空の直方状のケース１により光学室２を形成して
いる。ケース１には、光の反射率を下げるとともに、形
成を容易ならしめるために黒色のＡＢＳ樹脂などが用い
られている。なお、ケース１をアルミで構成するように
してもよい。In the light scattering type particle detection sensor according to the present embodiment, the optical chamber 2 is formed by the hollow rectangular case 1. In the case 1, a black ABS resin or the like is used to reduce the light reflectance and facilitate the formation. The case 1 may be made of aluminum.
【０００９】ケース１の左上角には投光素子４及び投光
レンズ８を設け、投光素子４からの光ビームの光軸が対
角位置にある右下角に向けて射出されるように配置して
いる。この投光ビームが通過する範囲を投光領域とす
る。投光素子４としては、ＬＥＤや半導体レーザ、固定
レーザ等が用いられる。また、投光レンズ８は、投光素
子４から照射された光を集光させ、後述する検知領域イ
に集中させるために用いられる。A light projecting element 4 and a light projecting lens 8 are provided at an upper left corner of the case 1, and are arranged so that an optical axis of a light beam from the light projecting element 4 is emitted toward a diagonally lower right corner. doing. The range through which the light beam passes is referred to as a light projecting area. As the light projecting element 4, an LED, a semiconductor laser, a fixed laser, or the like is used. Further, the light projecting lens 8 is used for condensing the light emitted from the light projecting element 4 and concentrating it on a detection area A described later.
【００１０】また、ケース１の右上角には受光素子５及
び受光レンズ７を設け、受光素子５から受光レンズ７を
介して見える領域（受光領域）の光軸が対角位置にある
左下角に向くように配置している。受光素子５として
は、フォトダイオードやフォトトランジスタなどが用い
られる。また、受光レンズ７は、受光効率を上げるため
に用いられており、これにより受光素子５の出力を受け
て信号処理を行う処理回路の負担を軽減している。な
お、受光素子５に対する電気ノイズの影響を少なくする
ために、シールド部材（図示せず）を用いて受光面を除
く受光素子５の外面を覆うようにしてもよい。A light receiving element 5 and a light receiving lens 7 are provided at the upper right corner of the case 1, and the optical axis of a region (light receiving area) viewed from the light receiving element 5 through the light receiving lens 7 is located at the lower left corner at a diagonal position. It is arranged to face. As the light receiving element 5, a photodiode or a phototransistor is used. The light receiving lens 7 is used to increase the light receiving efficiency, thereby reducing the load on a processing circuit that receives the output of the light receiving element 5 and performs signal processing. Note that, in order to reduce the influence of electric noise on the light receiving element 5, a shield member (not shown) may be used to cover the outer surface of the light receiving element 5 except for the light receiving surface.
【００１１】投光素子４はケース１に一体形成されたア
パーチャー６によって投光領域を制限してあり、また受
光素子５はケース１に一体形成されたフード９により受
光領域を制限してある。The light projecting area of the light emitting element 4 is limited by an aperture 6 formed integrally with the case 1, and the light receiving area of the light receiving element 5 is limited by a hood 9 formed integrally with the case 1.
【００１２】上述したケース１は、図２に示すように、
位置側面が開口された矩形箱状で光学室２の一側壁とな
る面の外面に受光素子５の出力に応じて適宜信号処理を
行う処理回路を構成するプリント基板（図示せず）が装
着されたベース１ａと、このベース１ａの開口に被着さ
れるカバー１ｂとで構成してある。アパーチャー６及び
フード９は、ベース１ａとカバー１ｂとに分離形成さ
れ、ベース１ａにカバー１ｂを被着した状態でアパーチ
ャー６及びフード９が形成されるようにしてある。ま
た、検知領域イの投光素子４及び受光素子５が配置され
た側（図１中の検知領域イの上方）及びその反対側（図
１中の検知領域イの下方）における投光領域及び受光領
域に入らない近傍に遮光壁１１ａ、１１ｂを設けてあ
る。The case 1 described above, as shown in FIG.
A printed circuit board (not shown) constituting a processing circuit for appropriately performing signal processing in accordance with the output of the light receiving element 5 is mounted on the outer surface of the rectangular box-shaped surface having the position side surface opened and serving as one side wall of the optical chamber 2. A base 1a and a cover 1b attached to the opening of the base 1a. The aperture 6 and the hood 9 are formed separately from the base 1a and the cover 1b, and the aperture 6 and the hood 9 are formed with the cover 1b attached to the base 1a. Further, the light emitting areas on the side of the detection area A where the light emitting element 4 and the light receiving element 5 are arranged (above the detection area A in FIG. 1) and the opposite side (below the detection area A in FIG. 1) and Light shielding walls 11a and 11b are provided near the light receiving area.
【００１３】検知領域イは、投光素子４の投光領域と受
光素子５の受光領域とが重なる領域（図１中の斜線で示
す領域）となり、この検知領域イに一致させて煙や粉塵
などの粒子を流入させる流入口３をケース１の両側壁に
形成してある。この光散乱式粒子検知センサでは、検知
領域イにおける煙や粉塵等の粒子による投光素子４から
の光の散乱光を受光素子５にて受光することにより粒子
を検出する。この流入口３から検知領域イに入る粒子の
数が多いほど散乱光量が増えるため、受光素子５の受光
量も増えることになり、受光量を計測することにより粒
子の数を計測することができる。The detection area A is an area where the light-emitting area of the light-emitting element 4 and the light-receiving area of the light-receiving element 5 overlap (area indicated by oblique lines in FIG. 1). An inlet 3 through which particles such as particles flow is formed on both side walls of the case 1. In this light scattering type particle detection sensor, particles are detected by the light receiving element 5 receiving scattered light of light from the light emitting element 4 due to particles such as smoke and dust in the detection area A. Since the scattered light amount increases as the number of particles entering the detection area A from the inflow port 3 increases, the amount of light received by the light receiving element 5 also increases, and the number of particles can be measured by measuring the amount of received light. .
【００１４】ところで、本実施の形態においては、受光
素子５へ入射する受光領域の光軸上で、感煙領域から見
て受光素子５と反対側に、受光領域をカバーするだけの
開口を有する光トラップ１５を設けている。光トラップ
１５は、筒上で筒の径が徐々に小さくなるような形状を
有しており、その先端は光軸をそれるように側方に向け
て穏やかに曲がっている。従って、光トラップ１５の開
口から光トラップ１５の先端部は見えないようになって
いる。By the way, in the present embodiment, on the optical axis of the light receiving area which enters the light receiving element 5, an opening which covers the light receiving area is provided on the opposite side to the light receiving element 5 when viewed from the smoke sensing area. An optical trap 15 is provided. The optical trap 15 has a shape such that the diameter of the tube gradually decreases on the tube, and the tip is gently bent laterally so as to deviate from the optical axis. Therefore, the tip of the optical trap 15 cannot be seen from the opening of the optical trap 15.
【００１５】一般に、受光素子５へ迷光が入射する経路
としては様々考えられるが、受光領域の光軸上にある壁
面から反射した迷光は、受光素子５に対向する位置から
反射されるため最も受光素子５に入射しやすい。しか
し、本実施の形態のように、受光素子５と対向する位置
に光トラップ１５を形成するようにすれば、受光素子５
に入射する迷光の多くが光トラップ１５に取り込まれる
ことになる。光トラップ１５に入射した迷光は、光トラ
ップ１５の内側面で反射を繰り返しながら減衰していく
ため、受光素子５に入射する迷光をほぼ完全に遮断する
ことができる。これにより、投光素子４の投光パワーに
対して受光素子５へ入射する迷光パワーの比率を非常に
小さくすることが可能になり、粒子濃度の高感度測定が
可能になる。In general, there are various possible paths through which stray light enters the light receiving element 5, but stray light reflected from a wall surface on the optical axis of the light receiving area is reflected from a position facing the light receiving element 5 and is most likely to be received. It is easy to enter the element 5. However, if the optical trap 15 is formed at a position facing the light receiving element 5 as in this embodiment, the light receiving element 5
Most of the stray light incident on the optical trap 15 is taken into the optical trap 15. The stray light that has entered the optical trap 15 attenuates while being repeatedly reflected on the inner surface of the optical trap 15, so that the stray light that enters the light receiving element 5 can be almost completely blocked. This makes it possible to make the ratio of the stray light power incident on the light receiving element 5 to the light projection power of the light emitting element 4 extremely small, thereby enabling highly sensitive measurement of the particle concentration.
【００１６】また、埃等が光トラップ１５の壁面等に付
着し、迷光が光トラップ１５の奥に向けて反射されない
状況が生じたとしても、光トラップ１５が設置されてい
ない場合に比べて迷光パワーが十分減衰されることにな
る。加えて、埃の溜まりやすい光トラップ１５の先端が
受光素子５の光軸からずれるように配置されているの
で、光トラップ１５の内壁で減衰されることなく直接強
い光が光トラップ１５の先端に入射することがないた
め、先端に溜まった埃によりパワーの強い迷光が生じる
ことを防止することができる。Further, even if dust or the like adheres to the wall surface of the optical trap 15 and stray light is not reflected toward the inside of the optical trap 15, the stray light may be larger than when the optical trap 15 is not installed. The power will be sufficiently attenuated. In addition, since the tip of the optical trap 15 where dust easily accumulates is arranged so as to be displaced from the optical axis of the light receiving element 5, strong light is directly applied to the tip of the optical trap 15 without being attenuated by the inner wall of the optical trap 15. Since there is no incidence, it is possible to prevent generation of stray light having a strong power due to dust accumulated at the tip.
【００１７】なお、上述の実施の形態において、ケース
１が中空の直方体とし、かつ光トラップ１５を軸が曲線
を描く略円錐形状としているが、要は光トラップ１５に
入射した迷光が光とラップ１５の内壁において十分反射
・低減され、受光素子５に迷光が入射されないようにさ
れる構造であれば、上述した形状に限定されるものでは
ない。In the above-described embodiment, the case 1 is a hollow rectangular parallelepiped, and the optical trap 15 has a substantially conical shape with a curved axis. The point is that the stray light incident on the optical trap 15 wraps with the light. The shape is not limited to the above-mentioned shape as long as it is a structure that is sufficiently reflected / reduced on the inner wall 15 so that stray light does not enter the light receiving element 5.
【００１８】[0018]
【発明の効果】以上のように、請求項１記載の発明にあ
っては、それぞれ光軸を交差させる形で光学室内に配置
された投光素子と受光素子とを備え、投光素子の投光領
域と受光素子の受光領域とが重合する領域である検知領
域における煙や粉塵等の粒子による投光素子からの散乱
光を受光素子にて受光することにより粒子を検知する光
散乱式粒子検知センサにおいて、受光素子の受光領域を
捕捉する開口を有し、奥に進むにつれて筒の径が徐々に
小さくなる構造を有した光トラップを受光素子と対向す
る位置に設けたので、投光素子から照射され迷光となる
光を光トラップで捉え、光トラップ内で減衰することが
でき、十分なＳ／Ｎ比をとることが可能になるため、従
来のものと比較して一層の高感度化を可能とする光散乱
式粒子検知センサを提供することができるという効果を
奏する。As described above, according to the first aspect of the present invention, there are provided a light projecting element and a light receiving element which are arranged in the optical chamber so that the optical axes cross each other. Light scattering type particle detection that detects particles by receiving light scattered from the light emitting element by particles such as smoke and dust from the light emitting element in the detection area where the light area and the light receiving area of the light receiving element overlap. The sensor has an opening for capturing the light-receiving area of the light-receiving element, and an optical trap having a structure in which the diameter of the cylinder gradually decreases as it goes deeper is provided at a position facing the light-receiving element. The light that is emitted and becomes stray light is captured by the optical trap, and can be attenuated in the optical trap, and a sufficient S / N ratio can be obtained. Light scattering particle detection sensor An effect that can be provided.
【図１】光散乱式粒子検知センサの縦断面図である。FIG. 1 is a longitudinal sectional view of a light scattering type particle detection sensor.
【図２】光散乱式粒子検知センサの分解斜視図である。FIG. 2 is an exploded perspective view of the light scattering type particle detection sensor.
２ 光学室 ４ 投光素子 ５ 受光素子 １５ 光トラップ イ 検知領域 2 Optical room 4 Light emitting element 5 Light receiving element 15 Optical trap a Detection area
Claims (1)
に配置された投光素子と受光素子とを備え、投光素子の
投光領域と受光素子の受光領域とが重合する領域である
検知領域における煙や粉塵等の粒子による投光素子から
の散乱光を受光素子にて受光することにより粒子を検知
する光散乱式粒子検知センサにおいて、受光素子の受光
領域を捕捉する開口を有し、奥に進むにつれて筒の径が
徐々に小さくなる構造を有した光トラップを受光素子と
対向する位置に設けたことを特徴とする光散乱式粒子検
知センサ。1. A detection device comprising: a light projecting element and a light receiving element arranged in an optical chamber so as to intersect an optical axis, wherein a light projecting area of the light projecting element and a light receiving area of the light receiving element overlap. In a light scattering type particle detection sensor that detects particles by receiving light scattered from a light emitting element due to particles such as smoke and dust in a region with a light receiving element, the opening has an opening for capturing a light receiving area of the light receiving element, A light-scattering type particle detection sensor, wherein an optical trap having a structure in which the diameter of a cylinder becomes gradually smaller toward the back is provided at a position facing a light receiving element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10018520A JPH11213263A (en) | 1998-01-30 | 1998-01-30 | Light scattering type particle detecting sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10018520A JPH11213263A (en) | 1998-01-30 | 1998-01-30 | Light scattering type particle detecting sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11213263A true JPH11213263A (en) | 1999-08-06 |
Family
ID=11973914
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10018520A Pending JPH11213263A (en) | 1998-01-30 | 1998-01-30 | Light scattering type particle detecting sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11213263A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010238095A (en) * | 2009-03-31 | 2010-10-21 | Nohmi Bosai Ltd | Photoelectric smoke sensor |
| KR101475086B1 (en) * | 2008-03-26 | 2014-12-23 | 노미 보사이 가부시키가이샤 | Photoelectric Smoke Detector |
| DE102005018559B4 (en) * | 2004-04-21 | 2017-07-27 | Nittan Company Ltd. | smoke detector |
| CN110084999A (en) * | 2019-04-29 | 2019-08-02 | 苏州工艺美术职业技术学院 | A kind of intelligence smoking-banning device |
| JP2019211800A (en) * | 2018-05-30 | 2019-12-12 | エア・ウォーター防災株式会社 | Smoke sensor |
-
1998
- 1998-01-30 JP JP10018520A patent/JPH11213263A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005018559B4 (en) * | 2004-04-21 | 2017-07-27 | Nittan Company Ltd. | smoke detector |
| KR101475086B1 (en) * | 2008-03-26 | 2014-12-23 | 노미 보사이 가부시키가이샤 | Photoelectric Smoke Detector |
| JP2010238095A (en) * | 2009-03-31 | 2010-10-21 | Nohmi Bosai Ltd | Photoelectric smoke sensor |
| JP2019211800A (en) * | 2018-05-30 | 2019-12-12 | エア・ウォーター防災株式会社 | Smoke sensor |
| CN110084999A (en) * | 2019-04-29 | 2019-08-02 | 苏州工艺美术职业技术学院 | A kind of intelligence smoking-banning device |
| CN110084999B (en) * | 2019-04-29 | 2020-09-11 | 苏州工艺美术职业技术学院 | Intelligent smoking ban |
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