JP2581838B2 - Light scattering particle detection sensor - Google Patents
Light scattering particle detection sensorInfo
- Publication number
- JP2581838B2 JP2581838B2 JP2288647A JP28864790A JP2581838B2 JP 2581838 B2 JP2581838 B2 JP 2581838B2 JP 2288647 A JP2288647 A JP 2288647A JP 28864790 A JP28864790 A JP 28864790A JP 2581838 B2 JP2581838 B2 JP 2581838B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- light receiving
- area
- receiving element
- wall surface
- 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
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、空気清浄器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。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is intended to detect dust or smoke from tobacco in an air purifier or the like, or to detect smoke particles in a photoelectric smoke detector or the like. The present invention relates to a light scattering type particle detection sensor to be used.
［従来の技術］ この種の光散乱式粒子検知センサでは、夫々光軸を交
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などの
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、光学室を形成
するケースの壁構造を煙や粉塵等の粒子が流入しやすい
が外光は入りにくい２重構造としたり、あるいは複雑な
迷路（ラビリンス）構造としたりしていた。[Prior Art] This type of light scattering type particle detection sensor includes a light projecting element and a light receiving element which are disposed in an optical chamber so that their optical axes cross each other. An optical chamber is formed by detecting light-scattered light from the light-emitting element due to particles such as smoke and dust in the detection area where the light-receiving area overlaps with the light-receiving element, thereby forming an optical chamber. The wall structure of the case has a double structure in which particles such as smoke and dust easily flow in, but hardly allow outside light to enter, or a complicated maze (labyrinth) structure.
ところで、この種の光散乱式粒子検知センサにおいて
は、近年微弱濃度の煙なども検出できるように高感度化
し、且つ装置内に内蔵することができるように小形化す
ることが望まれるようになっている。In recent years, it has been desired to increase the sensitivity of this type of light scattering type particle detection sensor so that it can detect even a very low concentration of smoke and the like and to reduce the size so that it can be built into the apparatus. ing.
そこで、このような要望に答えるものとして、特開昭
61−53550号公報及び特開昭61−57835号公報による光電
式煙感知器が提案されている。In response to this demand, Japanese Patent Laid-Open
A photoelectric smoke detector according to Japanese Patent Application Laid-Open Nos. 61-53550 and 61-57835 has been proposed.
このように小形化し且つ高感度化を図った光散乱式粒
子検知センサにおいて問題になるのは、小形化により光
学室の内壁によって反射されて受光素子に入射される迷
光レベルが、検知領域における粒子により散乱された散
乱光が受光素子に入射されるレベルに比べて増加し、十
分な光学的なS/N比を確保することができなくなる点に
ある。The problem with the light-scattering type particle detection sensor that has been miniaturized and improved in sensitivity as described above is that the stray light level reflected by the inner wall of the optical chamber and incident on the light receiving element due to the miniaturization causes the particles in the detection area to have a small size. The point is that the scattered light scattered by the light increases compared to the level incident on the light receiving element, and a sufficient optical S / N ratio cannot be secured.
そこで、上記特開昭61−53550号公報の光電式煙感知
器においては、検知領域を通過した投光素子４から投光
された光を第８図（ｂ）に示すように光学室２を構成す
るケース１′の両側壁1a′,1b′間で数回にわたって反
射させることにより、たとえ上記迷光が受光素子５に入
射されてもそのレベルが微弱なものとなるようにして、
S/N比の向上させるようにしてある。Therefore, in the photoelectric smoke detector disclosed in Japanese Patent Application Laid-Open No. 61-53550, the light emitted from the light emitting element 4 passing through the detection area is transmitted to the optical chamber 2 as shown in FIG. By reflecting the light several times between the side walls 1a 'and 1b' of the case 1 'to be constituted, even if the stray light is incident on the light receiving element 5, its level becomes weak.
The S / N ratio is improved.
［発明が解決しようとする課題］ ところが、上述の光電式煙感知器においては、長期使
用あるいは設置環境によって光学室２の壁面に埃が付着
した場合に、埃によって光が散乱されて、受光素子で受
光される迷光分が増加し、S/N比の悪化の原因となる問
題があった。しかも、車載据置型の空気清浄器に内蔵さ
れる場合、光散乱式粒子検知センサを縦置きと横置きと
のいずれの状態でも内蔵できることが望まれる。ところ
が、上述の光電式煙感知器では横置きにした場合に埃が
壁面に付着しやすいという問題があった。[Problems to be Solved by the Invention] However, in the above-described photoelectric smoke detector, when dust adheres to the wall surface of the optical chamber 2 due to long-term use or installation environment, the light is scattered by the dust and the light receiving element However, there is a problem that the amount of stray light received by the light source increases and the S / N ratio deteriorates. Moreover, when the light scattering type particle detection sensor is incorporated in an in-vehicle stationary air purifier, it is desirable that the light scattering type particle detection sensor can be incorporated in either a vertical or horizontal state. However, the above-described photoelectric smoke detector has a problem that dust is easily attached to a wall surface when the photoelectric smoke detector is placed horizontally.
本発明は上述の点に鑑みて為されたものであり、その
目的とするところは、壁面への埃の付着によりS/N比を
悪化させることがない、小形且つ高感度な光散乱式粒子
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 points, and an object of the present invention is to prevent the S / N ratio from deteriorating due to the adhesion of dust to a wall surface, a small and highly sensitive light scattering particle. It is to provide a detection sensor.
［課題を解決するための手段］ 上記目的を達成するために、本発明に係る光散乱式粒
子検知センサは、夫々光軸を交差させる形で光学室２内
に配置された投光素子４と受光素子５とを備え、投光素
子４の投光領域と受光素子５の受光領域とが重合する領
域である検知領域イにおける煙や粉塵など粒子による投
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ものであるが、光学室２が形成
された中空の直方状のケース１内の一端面壁1fの上方
に、光軸を前記一端壁面に1fに対向する他端壁面1eの下
方方向に向けて発光ダイオードなどの投光素子４を配置
すると共に、その他端壁面1eの上方に、光軸を前記一端
壁面1fの下方方向に向けてフォトダイオードなどの受光
素子５を配置して、ケース１の光学室２内に一体形成さ
れたアパーチャ６により投光素子４による投光領域を制
限すると共に、ケース１の光学室２内に一体形成された
フード９により受光素子５による受光領域を制限して両
領域が重合する検知領域イを形成し、その検知領域イに
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の両側壁面に設け、かつその検知領域イの近傍
の上方位置に、投光素子４からの直射光が受光素子５に
入射されないようにするための、断面形状が略台形状で
底部を三角形状に凹設した遮光部10を設けて成ることを
特徴とするもので、少なくとも、受光素子５の受光領域
の前方に望む光学室２の壁面が、横置き状態又は縦置き
状態に関係なく下方に向くように形成して、光学室２の
内壁面に、煙や粉塵などの粒子による埃が付着しないよ
うにしている。[Means for Solving the Problems] In order to achieve the above object, a light scattering type particle detection sensor according to the present invention includes a light projecting element 4 disposed in an optical chamber 2 so as to cross an optical axis. A light receiving element 5 is provided, and light scattered from the light emitting element 4 due to particles such as smoke and dust is detected in a detection area A, which 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. Although the particles are detected by receiving light with the light receiving element 5, the optical axis is set to 1f above the one end wall 1f in the hollow rectangular case 1 in which the optical chamber 2 is formed. A light-emitting element 4 such as a light-emitting diode is disposed in a downward direction of the opposite end wall surface 1e, and a photodiode or the like having an optical axis directed downward of the one end wall surface 1f above the other end wall surface 1e. The light receiving element 5 is arranged and integrated into the optical chamber 2 of the case 1. The aperture 6 formed limits the light projecting area of the light projecting element 4, and the hood 9 integrally formed in the optical chamber 2 of the case 1 limits the light receiving area of the light receiving element 5 so that both areas overlap. An inflow port 3 is formed on both side wall surfaces of the case 1 to form a region A and allow particles such as smoke and dust to flow in accordance with the detection region A, and a light projecting element is provided at an upper position near the detection region A. In order to prevent the direct light from 4 from being incident on the light-receiving element 5, a light-shielding portion 10 having a substantially trapezoidal cross section and a concave bottom portion formed in a triangular shape is provided, at least, The wall surface of the optical chamber 2 which is desired in front of the light receiving area of the light receiving element 5 is formed so as to face downward regardless of the horizontal or vertical state, and particles such as smoke and dust are formed on the inner wall surface of the optical chamber 2. To prevent dust from adhering
［作用］ 本発明に係る光散乱式粒子検知センサは前記のように
構成することにより、投光素子４と受光素子５とで構成
される光学系ユニットの配置が横置き状態又は縦置き状
態に関係なく、すなわち空気の流れが水平方向であって
もまた鉛直方向であっても、ケース１の光学室２内に一
体形成されたアパーチャ６によって投光素子４による投
光領域を制限すると共に、ケース１に一体形成されたフ
ード９により受光素子５による受光領域を制限して、煙
や粉塵などの粒子を流入させる流入口３に一致する正確
な位置に検知領域イを設定しており、特に、迷光の増加
をもたらす受光素子５の受光領域の前方に臨む光学室２
の壁面に、煙とか粉塵などの粒子による埃が付着しにく
いようにして、小型でかつ高感度であっても経済的なS/
N比の劣化を防止し、しかも、遮光部10の断面形状が略
台形状で、その底部を三角形状に凹設したことにより、
遮光部10の下部のエッジに結露が生じないようにしてい
る。[Operation] By configuring the light scattering type particle detection sensor according to the present invention as described above, the arrangement of the optical system unit including the light projecting element 4 and the light receiving element 5 can be set in the horizontal state or the vertical state. Irrespective of whether the flow of air is horizontal or vertical, the aperture 6 integrally formed in the optical chamber 2 of the case 1 limits the projection area of the projection element 4, The light receiving area of the light receiving element 5 is limited by the hood 9 integrally formed with the case 1, and the detection area A is set at an accurate position corresponding to the inlet 3 through which particles such as smoke and dust flow. Optical chamber 2 facing the light receiving area of light receiving element 5 which causes an increase in stray light
S / D is small and highly sensitive even if it is small and highly sensitive by preventing dust such as smoke and dust from adhering to the wall of
Prevents the N ratio from deteriorating, and furthermore, the light-shielding portion 10 has a substantially trapezoidal cross-sectional shape, and its bottom is recessed in a triangular shape,
The lower edge of the light shield 10 is prevented from dew condensation.
［実施例１］ 第１図及び第２図に本発明の一実施例を示す。本実施
例の光散乱式粒子検知センサでは、第１図に示すように
中空の直方状のケース１により光学室２を形成し、上記
ケース１内の一端面の上方に光軸を他端面の下方方向に
向けて発光ダイオードなどの投光素子４を配置すると共
に、他端面の上方に光軸を一端面の下方に向けてフォト
ダイオードなどの受光素子５を配置してある。ここで、
投光素子４はケース１に一体形成されたアパーチャ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。なお、フード９の内面には光トラップ８を設け
ると共に、受光レンズ７を設けてある。但し、上記受光
レンズ７は必ずしも用いなくてもよいのであるが、受光
効率を上げて受光素子５の出力を受けて信号処理を行う
処理回路の負担を軽くするために本実施例では設けてあ
る。また、受光素子５には電気ノイズの影響を少なくす
るためにシールド部材15で受光面を除く外面を覆ってあ
る。上記ケース１は、第２図に示すように、一側面が開
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16が装着されたベース1aと、こ
のベース1aの開口に披着されるカバー1bとで構成してあ
り、少なくとも投光素子５を装着するアパーチャ６はベ
ース1aとカバー1bとに分離形成し、ベース1aにカバー1b
を披着した状態でアパーチャ６が形成されるようにして
ある。Embodiment 1 FIGS. 1 and 2 show an embodiment of the present invention. In the light scattering type particle detection sensor of this embodiment, as shown in FIG. 1, an optical chamber 2 is formed by a hollow rectangular case 1, and an optical axis is provided above one end surface in the case 1. A light emitting element 4 such as a light emitting diode is arranged downward, and a light receiving element 5 such as a photodiode is arranged above the other end face with the optical axis directed below one end face. here,
The light emitting 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. The light trap 8 and the light receiving lens 7 are provided on the inner surface of the hood 9. However, the light receiving lens 7 is not necessarily used. However, the light receiving lens 7 is provided in the present embodiment in order to increase the light receiving efficiency and reduce the load on the processing circuit that receives the output of the light receiving element 5 and performs signal processing. . The light receiving element 5 is covered with a shield member 15 on the outer surface except for the light receiving surface in order to reduce the influence of electric noise. As shown in FIG. 2, the case 1 has a rectangular box shape with one side surface opened, and a processing circuit for appropriately performing signal processing in accordance with an output of the light receiving element 5 on an outer surface of a surface serving as one side wall of the optical chamber 2. And a cover 1b mounted on an opening of the base 1a. At least an aperture 6 for mounting the light emitting element 5 includes the base 1a and the cover 1b. Separately, cover 1b on base 1a
Is formed so that the aperture 6 is formed.
検知領域は投光素子４の投光領域と受光素子５の受光
領域とが重なる領域（第１図中斜線で示す領域イ）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
ける煙や粉塵など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。The detection area 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 A shown by oblique lines in FIG. 1), and particles such as smoke and dust are matched with this detection area A. Inflow ports 3 for inflow are 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 light scattered from the light projecting element 4 due to particles such as smoke and dust in the detection area A.
なお、本実施例においてはさらに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（第１図中の検知領
域イの上方）における投光領域及び受光領域に共に入ら
ない近傍に遮光部10を設け、この遮光部10により投光素
子４からの直射光が受光素子５に入射されないようにし
てある。この遮光部10はケース１に一体に形成してあ
る。ここで、本実施例の遮光部10は断面形状が略台形状
で底部を三角形状に凹設してあり、遮光部10の下部のエ
ッジに結露を生じにくくしてある。Note that, in this embodiment, the vicinity of the detection area A on the side where the light emitting element 4 and the light receiving element 5 are disposed (above the detection area A in FIG. A light shielding unit 10 is provided so that direct light from the light emitting element 4 is not incident on the light receiving element 5 by the light shielding unit 10. The light shielding part 10 is formed integrally with the case 1. Here, the light-shielding portion 10 of the present embodiment has a substantially trapezoidal cross-section and a triangular concave bottom portion, so that the lower edge of the light-shielding portion 10 is less likely to cause dew condensation.
ところで、この種の光散乱式粒子検知センサにおいて
は、光学室２の内壁面に埃などが付着すると迷光が増大
する。ここで、迷光を増大させる最大の要因となるの
は、受光素子５の受光領域の前方に臨む光学室２の一端
壁1fに埃が付着する場合であり、次に投光素子４の投光
領域の前方に望む他端壁1eに埃が付着する場合である。By the way, in this type of light scattering type particle detection sensor, stray light increases when dust or the like adheres to the inner wall surface of the optical chamber 2. Here, the largest factor for increasing the stray light is when dust adheres to one end wall 1f of the optical chamber 2 facing the light receiving area of the light receiving element 5, and then the light projection element 4 emits light. This is a case where dust adheres to the other end wall 1e desired in front of the area.
そこで、本実施例ではこれら端壁面1e,1fを夫々下方
に向く面に形成してある（いわゆるオーバーハングさせ
てある）。従って、端壁面1e,1fへの埃の付着を少なく
して、迷光の増大を防止できる。なお、本実施例の場合
には、さらに光散乱式粒子検知センサが横置きあるいは
縦置きのいずれでも使用されることを考慮し、上記端壁
面1e,1fが常に下方を向くように形成してある。従っ
て、例えば車載据置型の空気清浄器などに内蔵される場
合の配設方法の自由度が増す利点がある。なお、このよ
うに上記端壁面1e,1fを形成すると、投光素子４からの
光を反射させることができ、さらに投光素子４の迷光と
なる光の反射回数を増加させることが望め、S/N比を改
善することが期待できる。Therefore, in the present embodiment, these end wall surfaces 1e and 1f are formed on the surfaces facing downward (so-called overhang). Therefore, it is possible to prevent dust from adhering to the end wall surfaces 1e and 1f, thereby preventing stray light from increasing. In the case of the present embodiment, further considering that the light scattering type particle detection sensor is used either horizontally or vertically, the end wall surfaces 1e and 1f are formed so as to always face downward. is there. Therefore, there is an advantage that the degree of freedom of the arrangement method is increased, for example, when the air purifier is built in a vehicle-mounted stationary air purifier. By forming the end wall surfaces 1e and 1f as described above, light from the light projecting element 4 can be reflected, and it is expected that the number of times of reflection of stray light from the light projecting element 4 can be increased. It can be expected to improve the / N ratio.
なお、本実施例では投光素子４の投光領域の前方に望
む壁面1eもオーバーハングさせてあったが、少なくとも
受光素子５の受光領域の前方に望む壁面1fをオーバーハ
ングさせておけばよいことは言うまでもない。In the present embodiment, the wall surface 1e desired in front of the light emitting area of the light emitting element 4 is also overhanged. However, at least the wall surface 1f desired in front of the light receiving area of the light receiving element 5 may be overhanged. Needless to say.
［実施例２］ 第３図及び第４図は本発明の他の実施例を示す図であ
り、壁面1e,1fで投光素子４及び受光素子５に近い部分
に埃が付着すると迷光の増加が著しくなることは明白で
ある。そこで、壁面1e,1fにおける投光素子４及び受光
素子５に近い部分のオーバーハング角がきつくなるよう
に、壁面1e,1fを曲面に形成した場合を示す。このよう
にすれば、さらに良好な埃の付着の防止効果を得られ
る。Embodiment 2 FIGS. 3 and 4 are views showing another embodiment of the present invention. When dust adheres to portions near the light emitting element 4 and the light receiving element 5 on the wall surfaces 1e and 1f, stray light increases. It is evident that Therefore, a case is shown in which the wall surfaces 1e, 1f are formed into curved surfaces so that the overhang angles of the walls 1e, 1f near the light projecting element 4 and the light receiving element 5 become tight. By doing so, a more favorable effect of preventing dust from being attached can be obtained.
［実施例３］ 第５図乃至第７図に本発明のさらに他の実施例を示
す。本実施例の場合には、検知領域イの投光素子４及び
受光素子５が配置された側とは反対側（第５図中の検知
領域イの下方）で投光領域と受光領域とが重なり合う検
知領域イの境界部に先端が臨み光学室２の下部を投光素
子４及び受光素子５側に分離する遮光壁11を設けてある
点に特徴を有する。この遮光壁11はケース１に一体に形
成してある。ここで、遮光壁11の先端は尖らせ結露を生
じにくくしてある。Third Embodiment FIGS. 5 to 7 show still another embodiment of the present invention. In the case of the present embodiment, the light projecting area and the light receiving area are opposite to each other on the side opposite to the side where the light emitting element 4 and the light receiving element 5 are arranged (below the detecting area A in FIG. 5). It is characterized in that a light-shielding wall 11 is provided, the end of which faces the boundary between the overlapping detection areas A and separates the lower part of the optical chamber 2 into the light projecting element 4 and the light receiving element 5 side. This light shielding wall 11 is formed integrally with the case 1. Here, the tip of the light shielding wall 11 is sharpened so that dew condensation hardly occurs.
このように遮光部10と共に、遮光部11を形成すると、
本実施例では投光素子４から投光された光を光学室２の
壁面などで迷光を十分に減衰させるにたる回数反射させ
て受光素子５に入射させるようにして、十分なS/N比を
とることが可能となるようにし、これによりさらに一層
の高感度化を可能としたものである。When the light shielding portion 11 is formed together with the light shielding portion 10 in this manner,
In this embodiment, the light projected from the light projecting element 4 is reflected by the wall surface of the optical chamber 2 a number of times to sufficiently attenuate the stray light and is incident on the light receiving element 5, so that the S / N ratio is sufficient. Thus, it is possible to further increase the sensitivity.
［発明の効果］ 本発明に係る光散乱式粒子検知センサは、投光素子と
受光素子とで構成される光学系ユニットの配置が横置き
状態又は縦置き状態に関係なく、すなわち空気の流れが
水平方向であってもまた鉛直方向であっても、ケースの
光学室内に一体形成されたアパーチャによって投光素子
による投光領域を制限すると共に、ケースに一体形成さ
れたフードにより受光素子による受光領域を制限して、
煙や粉塵などの粒子を流入させる流入口に一致する正確
な位置に検知領域を設定でき、特に、迷光の増加をもた
らす受光素子の受光領域の前方に臨む光学室の内壁面
に、煙とか粉塵などの粒子による埃が付着しにくいよう
にして、小型でかつ高感度であっても経済的なS/N比の
劣化を防止でき、しかも、遮光部の断面形状が略台形状
で、その底部を三角形状に凹設したことにより、遮光部
の下部のエッジに結露を生じないという効果がある。[Effects of the Invention] In the light scattering type particle detection sensor according to the present invention, the arrangement of the optical system unit including the light projecting element and the light receiving element is independent of the horizontal state or the vertical state. In either the horizontal direction or the vertical direction, the aperture formed integrally in the optical chamber of the case limits the light projection area of the light emitting element, and the hood formed integrally with the case defines the light receiving area of the light receiving element. By limiting
The detection area can be set at a precise position that matches the inlet where particles such as smoke and dust flow, and in particular, the smoke or dust on the inner wall of the optical room facing the light receiving area of the light receiving element that causes an increase in stray light It prevents dust from adhering to particles and prevents the S / N ratio from deteriorating economically even if it is small and highly sensitive. Is formed in a triangular shape, there is an effect that dew condensation does not occur on the lower edge of the light shielding portion.
第１図は本発明の一実施例の縦断面図、第２図は同上を
分離した部分斜視図、第３図は他の実施例の縦断面図、
第４図は同上を分離した部分斜視図、第５図はさらに他
の実施例の縦断面図、第６図は同上の横断面図、第７図
は同上を分離した部分斜視図、第８図（ａ），（ｂ）は
従来例の縦断面図及び横断面図である。 １はケース、1e,1fは端壁面、２は光学室、３は煙や粉
塵などの粒子を流入させる流入口、４は投光素子、５は
受光素子、９はフード、10は遮光部、イは検知領域であ
る。FIG. 1 is a longitudinal sectional view of one embodiment of the present invention, FIG. 2 is a partial perspective view of the same separated, FIG. 3 is a longitudinal sectional view of another embodiment,
FIG. 4 is a partial perspective view of the same embodiment, FIG. 5 is a longitudinal sectional view of another embodiment, FIG. 6 is a transverse sectional view of the same embodiment, FIG. 7 is a partial perspective view of the same embodiment, FIG. 1A and 1B are a longitudinal sectional view and a transverse sectional view of a conventional example. 1 is a case, 1e and 1f are end walls, 2 is an optical chamber, 3 is an inflow port for inflow of particles such as smoke and dust, 4 is a light emitting element, 5 is a light receiving element, 9 is a hood, 10 is a light shielding section, A is a detection area.
Claims (1)
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など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
する光散乱式粒子検知センサにおいて、光学室が形成さ
れた中空の直方状のケース内の一端壁面の上方に、光軸
を前記一端壁面に対向する他端壁面の下方方向に向けて
発光ダイオードなどの投光素子を配置すると共に、その
地端壁面の上方に、光軸を前記一端壁面の下方方向に向
けてフォトダイオードなどの受光素子を配置して、ケー
スの光学室内に一体形成されたアパーチャにより投光素
子による投光領域を制限すると共に、ケースの光学室内
に一体形成されたフードにより受光素子による受光領域
を制限して両領域が重合する検知領域を形成し、その検
知領域に一致させて煙や粉塵などの粒子を流入させる流
入口をケースの両側壁面に設け、かつその検知領域の近
傍の上方位置に、投光素子からの直射光が受光素子に入
射されないようにするための、断面形状が略台形状で底
部を三角形状に凹設した遮光部を設けて成ることを特徴
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 light from the light emitting element due to particles such as smoke and dust in the area with the light receiving element, a hollow rectangular shape with an optical chamber formed A light emitting element such as a light emitting diode is disposed above the one end wall surface in the case with the optical axis directed downward from the other end wall surface facing the one end wall surface, and the optical axis is disposed above the ground end wall surface. A light receiving element such as a photodiode is arranged in a downward direction of the one end wall surface, and an aperture formed integrally in the optical chamber of the case limits a light projecting area of the light emitting element and is integrally formed in the optical chamber of the case. Was done Forming a detection area in which the light receiving area of the light receiving element is overlapped by the light receiving element, and inflow ports for inflow of particles such as smoke and dust in accordance with the detection area are provided on both side walls of the case; and A light shielding portion having a substantially trapezoidal cross section and a triangular bottom portion is provided at an upper position near the detection area to prevent direct light from the light emitting element from being incident on the light receiving element. A light scattering type particle detection sensor characterized by the above-mentioned.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2288647A JP2581838B2 (en) | 1990-10-25 | 1990-10-25 | Light scattering particle detection sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2288647A JP2581838B2 (en) | 1990-10-25 | 1990-10-25 | Light scattering particle detection sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04160698A JPH04160698A (en) | 1992-06-03 |
| JP2581838B2 true JP2581838B2 (en) | 1997-02-12 |
Family
ID=17732872
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2288647A Expired - Fee Related JP2581838B2 (en) | 1990-10-25 | 1990-10-25 | Light scattering particle detection sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2581838B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3015635B2 (en) * | 1993-09-07 | 2000-03-06 | ホーチキ株式会社 | Scattered light smoke detector |
| JP3015634B2 (en) * | 1993-09-07 | 2000-03-06 | ホーチキ株式会社 | Scattered light smoke detector |
| DE4406398A1 (en) * | 1994-02-26 | 1995-08-31 | Bosch Gmbh Robert | rain sensor |
| WO2006112085A1 (en) | 2005-03-31 | 2006-10-26 | Fenwal Controls Of Japan, Ltd. | Photoelectric smoke detector |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5833599B2 (en) * | 1976-08-31 | 1983-07-20 | 松下電工株式会社 | Scattered light smoke detector |
-
1990
- 1990-10-25 JP JP2288647A patent/JP2581838B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04160698A (en) | 1992-06-03 |
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