JPS6157835A - Photoelectric smoke detector - Google Patents

Abstract

PURPOSE:To eliminate the need for an optical trap mechanism, and to narrow down a measurement space and to reduce the size by reflecting a radiant light beam from a projection several times by a right and a left wall through a front and a rear wall and preventing the reflected light from striking on a photodetector directly. CONSTITUTION:The radiant light from the projector 1 is reflected at the left side of the front wall 6, reflected by the left wall 4 and right and left walls 5 and 4, and further reflected by a ceiling wall 9, walls 5 and 4, and rear wall 7 to strike the external wall of the photodetector 2. Therefore, the radiant light from the projector 1 becomes weak light through optical trapping operation while reflected by the walls 4 and 5 several times. If smoke enters a darkroom owing to fire occurrence, on the other hand, its scattered light illuminates the photodetecting element of the photodetector 2 to generates an output of fire annunciation. The output of the photodetexting element when the smoke enters the room to specific thickness where fire occurrence is judged is denoted S and an output in a normal state is denoted as N; and when the angle theta between the front and rear walls 6 and 7 is <=140 deg. or >=210 deg., a sufficient S/N is obtained.

Description

【発明の詳細な説明】 〔産業−１−の利用分野〕 この発明は小型の光電式煙感知器に関するものである。[Detailed description of the invention] [Application field of industry-1-] This invention relates to a small photoelectric smoke detector.

〔従来の技術〕[Conventional technology]

従来の光電式煙感知器の暗室は、環境光が暗室に入らな
いようにまた煙が進入しやすい、Ｌうに複雑な迷路構造
がとられたり、カバーを２重構造などにしていた。The darkroom of conventional photoelectric smoke detectors has a complicated labyrinth structure or a double cover structure to prevent ambient light from entering the darkroom and allow smoke to easily enter.

〔従来技術の問題点〕[Problems with conventional technology]

しかし上記のような構造では、形が大きく、電子計算機
などの機器内蔵用あるいは航空機の化粧室などに設ける
感知器としては不ｉＪ￥１当であり、またこれらをｆｊ
ｉ　ｌこ縮小し小形にするとＳＮ比が悪くなる欠点があ
った。However, the structure described above is large in size, making it unsuitable for use as a sensor built into equipment such as a computer or installed in an aircraft lavatory.
If the device is reduced in size and made smaller, it has the disadvantage that the signal-to-noise ratio deteriorates.

〔問題点を解決するための手段〕[Means for solving problems]

この発明シ１ｒ、測定空間へ光を放射する投光器と測定
空間へ煙が進入したことにより生ずる）１（乱光を検出
する受光器とを備えた光電式煙感知器において、上記空
間を形成する暗室が、投光器の前方に設けられ投光器よ
りの光が光軸に対して所定角度で反射するような平面ま
たは曲面を備えた前壁と、上記投光器、１′、りの光軸
にほぼ平行した左右（！ｔｌｌ壁と、投光器の後方に設
けられ一１―記左右側壁よりの反射光が直接受光器を照
射しないような所′１１二川度で反射ずく、平面または
曲面を備えた後壁とで構成した光電式煙感知器とした。This invention 1r is a photoelectric smoke detector equipped with a light projector that emits light into a measurement space and a light receiver that detects scattered light (generated when smoke enters the measurement space), in which the space is formed. A dark room is provided in front of the projector, and has a front wall having a flat or curved surface such that the light from the projector is reflected at a predetermined angle with respect to the optical axis, and a front wall that is substantially parallel to the optical axis of the projector. Left and right (!tll) walls, and a rear wall with a flat or curved surface installed at the rear of the projector so that the reflected light from the left and right side walls does not directly illuminate the receiver. This is a photoelectric smoke detector composed of

〔作　　用〕[For production]

この発明の光電式煙感知器は、−上記構成にするごとに
より暗室自体に光トランプ機能を持たせ、ずなわら投光
器から放射される光線を前後壁を介、して左右側壁に何
回も反射させ直接の反射光が受光器の受光素ｒに入射さ
れないようにすることにより、あるいは入射されても極
めて微弱なものにすることにより、あらためて光トう・
ノブ機構を設ｉＪることのない測定空間の狭い小型の光
電式煙感知器としたものである。The photoelectric smoke detector of the present invention has the above-mentioned configuration, so that the dark room itself has a light playing function, and the light rays emitted from the floodlight are sent through the front and rear walls to the left and right side walls many times. By preventing the direct reflected light from entering the light-receiving element r of the light receiver, or by making it extremely weak even if it does enter, the light can be regenerated.
This is a small photoelectric smoke detector that does not require a knob mechanism and has a narrow measurement space.

〔実施例〕〔Example〕

以下この発明の光電式煙感知器の一実施例を第１図ない
し第３図により説明する。図において（ａｌばこの発明
の暗室の断面図、（ｂｌ　Ｌｊ’、その横断面図で、１
４；１発光ダイオードなどの光源とレンズなどを備えた
収斂光束を放射する投光器、２は太陽電池などの受光素
子とレンズなどからなる受光器、３は１凱受光器１．２
間に設けられた遮光板、４，５は投光器１よりＪｊシ射
される光線の光軸にほぼ平行して設けられた左右側壁、
６は投光器１の前方に設けられ投光器１よりの光が光軸
に対して所定角度で反射するような平面または曲面を備
えた前壁、７は投光器１の後方に設けられ左右側壁４．
５よりの反射光が受光器２の受光素子を直接照射しな゛
いように所定角度で反射さセる平面または曲面を備えた
後壁、８．１）は底壁および天井壁で、底壁８の中央お
よび天ノ１壁９の両端近くに煙流入孔（図示せず）が設
ｉＪられる。なお、壁面は黒色で鏡状に仕トげられてい
る。史に図においてＳε９１光ｌｉ１のスタート点を、
矢印Ｃ，Ｉ光＃ｊｌｉの到達箇所を、黒光にｌ側壁４と
の反！１・１ｆｆｉｉζ１所を、白丸Ｌｅｔ側壁５との
、−角は天井壁９との反射箇所を示ずものＣあイｊａｉ
ｌ’た第１図＋ｉ、光軸が受）１′、器２に対１．−ｉ
ｉ“１セ小左１Ｊ’　ｌｉｄ　ｔ、′そしてθ−１５（
ビの場合、第２図＋、１．．．　’ｌ’ｌ’、輔がヅ光
器２に対し）、−力向に５°イｊ７て０−１５　［１’
　（ハ場合、第３図は第１図の投光器１の用爪を１．、
−〕１ｔ：′セットした場合である。An embodiment of the photoelectric smoke detector of the present invention will be described below with reference to FIGS. 1 to 3. In the figure (al) a cross-sectional view of the darkroom of this invention, (bl Lj', in its cross-sectional view, 1
4; 1 is a light emitter that emits a convergent luminous flux that includes a light source such as a light emitting diode and a lens; 2 is a light receiver that includes a light-receiving element such as a solar cell and a lens; 3 is 1 and a light receiver 1.2
The light shielding plates 4 and 5 provided in between are left and right side walls provided substantially parallel to the optical axis of the light beam emitted from the projector 1;
6 is a front wall provided in front of the projector 1 and has a flat or curved surface such that the light from the projector 1 is reflected at a predetermined angle with respect to the optical axis; 7 is a front wall provided in the rear of the projector 1 and includes left and right side walls 4.
8.1) is a bottom wall and a ceiling wall; Smoke inlet holes (not shown) are provided near the center of the wall 8 and both ends of the top wall 9. The walls are painted black and mirror-like. In the diagram, the starting point of Sε91 light li1 is
Arrow C, point where I light #jli reaches to black light, opposite to l side wall 4! 1.1ffiiζ 1 place is a white circle Let side wall 5 - corner is a reflection point with ceiling wall 9
Figure 1 +i, the optical axis is 1', and the 1. -i
i "1st small left 1J' lid t,' and θ-15 (
In the case of B, Fig. 2+, 1. ．． ．． 'l'l', 5° in the force direction (relative to light device 2), 0-15 [1'
(In case C, Fig. 3 shows the use of the projector 1 in Fig. 1 as 1.
-]1t:' This is the case where it is set.

次に上記暗室の作用を説明する。例えば、第１図におい
て、投光器１より放射された光は、前壁６の左側で反射
し左側壁４にそして右、左側壁５゜４と反射し、更に天
井壁９、右側壁５、左側壁４、後壁７、の左側に反射し
、受光器２の外壁に衝突する。このよ・うに投光器１よ
り放射された光は、左右側壁４．５に数回反射される間
に光は減衰し光トラップとして作用し極めて微弱な光と
なる。Next, the function of the darkroom will be explained. For example, in FIG. 1, the light emitted from the floodlight 1 is reflected on the left side of the front wall 6, reflected on the left side wall 4, then reflected on the right side wall 5°4, and further reflected on the ceiling wall 9, the right side wall 5, and the left side wall 5. It is reflected to the left side of the wall 4 and the rear wall 7, and collides with the outer wall of the light receiver 2. The light thus emitted from the projector 1 is reflected several times by the left and right side walls 4.5, attenuating the light and acting as a light trap, resulting in extremely weak light.

また第２図においてさらに説明すると、投光器１より放
射された光は、前壁６の左側に反射し左側壁４にそして
右、左、右側壁、天井壁９、左側壁４、右側壁５、後壁
７の右側に反射し受光器２のり１璧に衝突する。また第
３図において、投光器１より放射された光は、前壁６の
左側に反射し左側壁４、天井壁９、右、左、右、左側壁
および後壁７の左側そして投光器１の外壁と衝突し微弱
な光にθ、璧衰される。To explain further in FIG. 2, the light emitted from the floodlight 1 is reflected to the left side of the front wall 6, and then to the left side wall 4, right, left, right side wall, ceiling wall 9, left side wall 4, right side wall 5, etc. It is reflected to the right side of the rear wall 7 and collides with the beam receiver 2. In addition, in FIG. 3, the light emitted from the floodlight 1 is reflected to the left side of the front wall 6, and is reflected to the left side wall 4, the ceiling wall 9, right, left, right, the left side wall, the left side of the rear wall 7, and the outer wall of the floodlight 1. It collides with the light and is attenuated by θ into a weak light.

・方、火災発生によりこの暗室内に煙が進入ずろとその
１１（乱光が受光器２の受光素子を照射し、火：ユ）発
生を報知する出力が律じる。上記火災発生と判断される
所定潤度の煙が暗室内へ進入したときの受光素子の出力
をＳまた平常時の出力をＮとし前後壁６，７の角度をθ
とすると、第４図の特性を示した。この図によれば、θ
が１４０°以下および２１０°以」二のところで実用に
供するに充分なＳＮ比が得られた。- On the other hand, when smoke enters the dark room due to a fire outbreak, the output that notifies the occurrence of fire (scattered light illuminates the light receiving element of the light receiver 2) is controlled. Suppose that the output of the light receiving element is S when the smoke with the predetermined moisture level that is determined to be the occurrence of a fire enters the dark room, and the output during normal times is N, and the angle of the front and rear walls 6 and 7 is θ.
Then, the characteristics shown in FIG. 4 are shown. According to this figure, θ
An S/N ratio sufficient for practical use was obtained when the angle was below 140° and above 210°.

〔効　　果〕〔effect〕

この発明の光電式煙感知器は、暗室を上記構成にし暗室
自体に光トラツプ機能を持たせるようにしたので、すな
わち投光器から放射される光線は前後壁を介して左右側
壁に何回も反射され直接の反射光が受光器の受光素子に
入射されないようになるので、あるいは入射されても極
めて微弱なものとなるので、あらためて光トラツプ機構
を設けることのない測定空間の狭い小型の光電式煙感知
器が得られる効果がある。In the photoelectric smoke detector of this invention, the darkroom has the above-described configuration and the darkroom itself has a light trapping function, meaning that the light rays emitted from the floodlight are reflected many times on the left and right side walls via the front and rear walls. This is a small photoelectric smoke detector with a narrow measurement space and no additional optical trapping mechanism, since the direct reflected light will not be incident on the light receiving element of the receiver, or even if it is incident, it will be extremely weak. There is an effect that the vessel can be obtained.

【図面の簡単な説明】[Brief explanation of drawings]

第１図ないし第３図はそれぞれこの発明の光電式煙感知
器の４１１１略図で、（・］）は断面図、（ｂｌはイー
の横断面図、第４図８１４．Ｙ性器線図であイ）。 １・・・投光器、２・・・受光２：ｉ、３・・・遮光板
、４・・・左側壁、５・・・右側壁、６・・・前壁、７
・・・後壁、８・・・底壁、９・・・天ノ１壁。 特許出願人能美防災工業株式会社 τ 第１図 （Ｇ） ９天ＦＪｆ増 （ｂ） 第２図 （ａ） （ｂ） １　　　　　　　　　　、＜） 第３図 （Ｑ＞ （ｂ） −９給相 艷Ｉ駅Ｅ＃頗Figures 1 to 3 are 4111 schematic diagrams of the photoelectric smoke detector of the present invention, (•] is a cross-sectional view, (bl is a cross-sectional view of E, and Figure 4 is a 814.Y genital line diagram. stomach). DESCRIPTION OF SYMBOLS 1... Emitter, 2... Light receiver 2:i, 3... Light shielding plate, 4... Left side wall, 5... Right side wall, 6... Front wall, 7
...Back wall, 8...Bottom wall, 9...Top 1 wall. Patent applicant Jinnomi Disaster Prevention Industry Co., Ltd. τ Figure 1 (G) 9 days FJf increase (b) Figure 2 (a) (b) 1, <) Figure 3 (Q> (b) -9 supply phase I Station E # Chestnut

Claims (1)

【特許請求の範囲】[Claims] 測定空間へ光を放射する投光器と測定空間へ煙が進入し
たことにより生ずる散乱光を検出する受光器とを備えた
光電式煙感知器において、上記空間を形成する暗室が、
投光器の前方に設けられ投光器よりの光が光軸に対し所
定角度で反射するような平面または曲面を備えた前壁と
、上記投光器よりの光軸にほぼ平行した左右側壁と、投
光器の後方に設けられ上記左右側壁よりの反射光が直接
受光器を照射しないような所定角度で反射する平面また
は曲面を備えた後壁とで構成されたことを特徴とする光
電式感知器。In a photoelectric smoke detector equipped with a light projector that emits light into a measurement space and a light receiver that detects scattered light caused by smoke entering the measurement space, the dark room forming the space is
A front wall provided in front of the projector and provided with a flat or curved surface that reflects the light from the projector at a predetermined angle with respect to the optical axis, left and right side walls approximately parallel to the optical axis from the projector, and a front wall provided at the rear of the projector. and a rear wall having a flat or curved surface that reflects light at a predetermined angle such that the light reflected from the left and right side walls does not directly illuminate the light receiver.