JP2011203890A - Smoke detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a smoke detector reliably detecting a fire with a simple configuration while providing a smoke detection space outside a casing.SOLUTION: The smoke detector, which determines the fire by emitting light into the smoke detection space outside the casing and receiving the light obtained by scattering the emitted light by a scattering body, includes: a light emitting element 7; a first light receiving element 9; a second light receiving element 11; and a polarizing filter 13 which polarizes the light emitted from the light emitting element 7 and the light received by the first light receiving element 9. A fire determination part 15 for determining the fire inputs a light receiving signal of the first light receiving element 9 entered through the polarizing filter 13 and a light receiving signal of the second light receiving element 11 entered without the polarizing filter 13 and determines the fire based on an output ratio of the light receiving signal of the first light receiving element 9 and the light receiving signal of the second light receiving element 11.

Description

Translated fromJapanese

本発明は、煙による散乱光を検出して煙を感知する煙感知器に関する。  The present invention relates to a smoke detector that detects smoke by detecting scattered light from smoke.

散乱光式の煙感知器は、一般的に感知器本体内に形成した検煙空間に外部から煙を導入し、該検煙空間に発光素子による光を照射して、煙の散乱光を受光素子で受光することによって火災を検出する。
しかしながら、このような感知器本体内に検煙空間を形成するものでは、設置状態において煙感知器が天井面などから突出した状態になるため意匠上好ましくないという問題や、また検煙空間へ煙を導入するという構造から煙の検出に時間遅れが発生するという問題がある。Scattered light smoke detectors generally introduce smoke from outside into a smoke detection space formed in the sensor body, irradiate the smoke detection space with light from a light emitting element, and receive the scattered light of the smoke. A fire is detected by receiving light at the element.
However, in the case where the smoke detection space is formed in such a detector body, the smoke detector protrudes from the ceiling surface or the like in the installed state, which is not preferable in terms of design, and smoke is not allowed in the smoke detection space. There is a problem that a time delay occurs in the detection of smoke due to the structure that introduces the.

そこで、このような検煙空間を感知器本体内部に設けることに起因する問題を解決するために、感知器本体内に検煙空間を設けるのではなく、感知器本体の外部に検煙空間を設けるようにした散乱光式煙感知器が提案されている（特許文献１参照）。  Therefore, in order to solve the problem caused by providing such a smoke detection space inside the sensor body, instead of providing a smoke detection space inside the sensor body, a smoke detection space is provided outside the sensor body. There has been proposed a scattered light type smoke detector provided (see Patent Document 1).

特許文献１に記載された散乱式煙感知器は、「感知器本体と、前記感知器本体の本体外面に設けた発光開口及び受光開口と、前記感知器本体の前記本体外面に装着されて前記発光開口及び前記受光開口を覆う透明カバーと、前記感知器本体に内蔵された発光手段、受光手段、及び火災判断手段とを備え、前記発光手段は、前記透明カバーの外側に位置する開放状の検煙空間に設定された検煙点に対して、前記発光開口を介して光を発し、前記受光手段は、前記検煙点に対して発せられた光に対する散乱光を、前記受光開口を介して受光し、この受光した散乱光の受光量に応じた受光信号を出力し、前記火災判断手段は、前記受光手段から出力された受光信号によって特定される前記受光量に基づいて、火災発生の有無を判断することを特徴とする。」（特許文献１［００１１］参照）ものである。  The scattering smoke detector described in Patent Document 1 is “attached to the sensor body, the light emitting opening and the light receiving opening provided on the outer surface of the sensor body, and the outer surface of the sensor body. A transparent cover that covers the light emitting opening and the light receiving opening, and a light emitting means, a light receiving means, and a fire determining means built in the sensor body, wherein the light emitting means is an open-shaped member located outside the transparent cover. Light is emitted to the smoke detection point set in the smoke detection space through the light emitting opening, and the light receiving means transmits scattered light to the light emitted to the smoke detection point through the light receiving opening. And receiving a light reception signal corresponding to the received light amount of the received scattered light, and the fire determining means is configured to generate a fire based on the light reception amount specified by the light reception signal output from the light receiving means. It is characterized by judging the presence or absence That. "(Patent Document 1 [0011] Referring) is intended.

特許文献１に開示された散乱光式煙感知器は、散乱光の受光量に応じた受光信号を出力し、その受光信号に基づいて火災の有無を判断するというものである。そして、火災判断の具体的手段として、受光量とその微分値に基づいて判断するようにしている。  The scattered light type smoke detector disclosed in Patent Document 1 outputs a light reception signal corresponding to the amount of scattered light received, and determines the presence or absence of a fire based on the light reception signal. And as a concrete means of fire judgment, judgment is made based on the amount of received light and its differential value.

特許第４３４７２９６号公報Japanese Patent No. 4347296

筐体の外に検煙空間を設けた場合に最も留意すべき点は、筐体外の検煙空間には煙以外の塵埃などが存在しているため、散乱光が煙による散乱光なのか煙以外の粒子による散乱光なのかを精度よく判別することである。
この点、特許文献１においては、受光素子による受光信号とその微分値に基づいて、それぞれの信号と予め規定している閾値とを比較して火災の煙による散乱光であるかどうかを判別するようにしている。The most important point to note when a smoke detection space is provided outside the housing is that there is dust other than smoke in the smoke detection space outside the housing. It is to discriminate accurately whether the light is scattered light by other particles.
In this regard, in Patent Document 1, based on the light reception signal from the light receiving element and its differential value, each signal is compared with a predetermined threshold value to determine whether the light is scattered light due to fire smoke. I am doing so.

しかしながら、特許文献１の判別は、基本的には散乱体の粒子径に基づく判別であるため、煙の粒子に近い細かい塵埃と煙粒子との区別が難しいという問題がある。
また、検煙空間に存在し得る種々の粒子について、予め散乱光による受光強度を調査する必要があり、現実的には実現が困難であるという問題もある。However, since the discrimination of Patent Document 1 is basically discrimination based on the particle size of the scatterer, there is a problem that it is difficult to distinguish fine dust close to smoke particles from smoke particles.
In addition, it is necessary to investigate the received light intensity of scattered light in advance for various particles that may exist in the smoke detection space, and there is a problem that it is difficult to realize in practice.

本発明は、かかる課題を解決するためになされたものであり、検煙空間を筐体外に設けながらも、簡易な構成で確実に火災を検知することができる煙感知器を得ることを目的としている。  The present invention has been made to solve such a problem, and an object thereof is to obtain a smoke detector that can reliably detect a fire with a simple configuration while providing a smoke detection space outside the housing. Yes.

（１）本発明に係る煙感知器は、筐体と、前記筐体の内部に配置され、前記筐体の外部の検煙部に向けて照射光を発光する発光部と、前記筐体の内部に配置され、前記発光部からの照射光が前記検煙部に存在する散乱体によって生じる散乱光を受光し、散乱光の受光量に基づいて受光信号を出力する受光部と、該受光部によって出力された受光信号に基づいて火災の有無を判断する火災判断部とを備える煙感知器において、
前記発光部は発光素子によって構成され、前記受光部は第１受光素子と第２受光素子によって構成され、前記発光素子から照射される光を偏光する第１偏光フィルタと、前記第１受光素子によって受光される光を前記第１偏光フィルタと同一方向に偏光する第２偏光フィルタとを備え、
前記火災判断部は、前記第２偏光フィルタを透過して入射される前記第１受光素子の受光信号と、前記第２偏光フィルタを透過しないで入射される前記第２受光素子の受光信号とを入力し、前記第１受光素子の受光信号と前記第２受光素子の受光信号の出力比に基づいて火災の有無を判断することを特徴とするものである。(1) A smoke detector according to the present invention includes a housing, a light emitting unit that is disposed inside the housing and emits irradiation light toward a smoke detecting unit outside the housing, A light receiving unit that is disposed inside, receives light scattered by a scatterer present in the smoke detector, and outputs a light reception signal based on the amount of scattered light received, and the light receiving unit In a smoke detector comprising a fire determination unit that determines the presence or absence of a fire based on the received light signal output by
The light emitting unit is configured by a light emitting element, the light receiving unit is configured by a first light receiving element and a second light receiving element, and a first polarizing filter that polarizes light emitted from the light emitting element, and the first light receiving element A second polarizing filter that polarizes received light in the same direction as the first polarizing filter;
The fire determination unit receives a light reception signal of the first light receiving element that is transmitted through the second polarizing filter and a light reception signal of the second light receiving element that is incident without passing through the second polarizing filter. The presence of a fire is determined based on the output ratio of the light receiving signal of the first light receiving element and the light receiving signal of the second light receiving element.

（２）上記（１）に記載のものにおいて、前記第１偏光フィルタと前記第２偏光フィルタを単一の偏光フィルタで構成したことを特徴とするものである。
（３）また、上記（１）又は（２）に記載のものにおいて、前記第１受光素子の受光信号から、前記第２偏光フィルタに内部反射して入射される分を補正する補正手段を備えたことを特徴とするものである。(2) In the above (1), the first polarizing filter and the second polarizing filter are configured by a single polarizing filter.
(3) Further, in the above (1) or (2), there is provided correction means for correcting the amount of light that is internally reflected and incident on the second polarizing filter from the light reception signal of the first light receiving element. It is characterized by that.

（４）また、本発明に係る煙感知器は、筐体と、前記筐体の内部に配置され、前記筐体の外部の検煙部に向けて照射光を発光する発光部と、前記筐体の内部に配置され、前記発光部からの照射光が前記検煙部に存在する散乱体によって生じる散乱光を受光し、散乱光の受光量に基づいて受光信号を出力する受光部と、該受光部によって出力された受光信号に基づいて火災の有無を判断する火災判断部とを備える煙感知器において、
前記発光部は発光素子で構成され、前記受光部は受光素子で構成され、前記発光素子から照射される光を偏光する第１偏光フィルタと、前記受光素子によって受光される光を前記第１偏光フィルタと同一方向に偏光する第２偏光フィルタとを備え、前記発光部は、前記第１偏光フィルタにより偏光された光を前記検煙部に発して、前記受光部は、前記第２偏光フィルタにより偏光された散乱光または偏光されない散乱光のいずれか一方を受光するもので構成され、前記受光部が前記第２偏光フィルタにより偏光された散乱光を受光するかまたは偏光されない散乱光を受光するかを切替させる制御部を有し、前記火災判断部は、前記第２偏光フィルタを透過して入射される受光信号と、前記第２偏光フィルタを透過しないで入射される受光信号との出力比に基づいて火災の有無を判断することを特徴とするものである。(4) In addition, a smoke detector according to the present invention includes a housing, a light emitting unit that is disposed inside the housing and emits irradiation light toward a smoke detecting unit outside the housing, and the housing. A light receiving unit that is disposed inside the body, receives scattered light generated by a scatterer present in the smoke detecting unit, and outputs a light reception signal based on the amount of scattered light received; In a smoke detector comprising a fire determination unit that determines the presence or absence of a fire based on a light reception signal output by a light reception unit,
The light emitting unit is composed of a light emitting element, the light receiving unit is composed of a light receiving element, and a first polarizing filter that polarizes light emitted from the light emitting element, and light received by the light receiving element is the first polarized light. A second polarizing filter that polarizes in the same direction as the filter, the light emitting unit emits light polarized by the first polarizing filter to the smoke detecting unit, and the light receiving unit is formed by the second polarizing filter. Whether it is configured to receive either polarized scattered light or non-polarized scattered light, and whether the light receiving unit receives scattered light polarized by the second polarizing filter or unscattered scattered light. The fire determination unit includes a light receiving signal that is transmitted through the second polarizing filter and a light receiving signal that is incident without passing through the second polarizing filter. Is characterized in that the determining the presence or absence of fire based on the output ratio.

（５）また、本発明に係る煙感知器は、筐体と、前記筐体の内部に配置され、前記筐体の外部の検煙部に向けて照射光を発光する発光部と、前記筐体の内部に配置され、前記発光部からの照射光が前記検煙部に存在する散乱体によって生じる散乱光を受光し、散乱光の受光量に基づいて受光信号を出力する受光部と、該受光部によって出力された受光信号に基づいて火災の有無を判断する火災判断部とを備える煙感知器において、
前記発光部は単一方向に偏光された光を発するレーザ素子で構成され、前記受光部は第１受光素子と第２受光素子によって構成され、前記第１受光素子によって受光される光を前記レーザ素子の偏光された光と同一方向に偏光する偏光フィルタを備え、前記火災判断部は、前記偏光フィルタを透過して入射される前記第１受光素子の受光信号と、前記偏光フィルタを透過しないで入射される前記第２受光素子の受光信号との出力比に基づいて火災の有無を判断することを特徴とするものである。(5) In addition, a smoke detector according to the present invention includes a housing, a light emitting unit that is disposed inside the housing and emits irradiation light toward a smoke detecting unit outside the housing, and the housing. A light receiving unit that is disposed inside the body, receives scattered light generated by a scatterer present in the smoke detecting unit, and outputs a light reception signal based on the amount of scattered light received; In a smoke detector comprising a fire determination unit that determines the presence or absence of a fire based on a light reception signal output by a light reception unit,
The light emitting unit is configured by a laser element that emits light polarized in a single direction, the light receiving unit is configured by a first light receiving element and a second light receiving element, and the light received by the first light receiving element is the laser. The fire determining unit includes a light receiving signal of the first light receiving element that is transmitted through the polarizing filter and is not transmitted through the polarizing filter. The presence / absence of a fire is determined based on an output ratio with the received light signal of the second light receiving element.

本発明においては、火災判断部に、第２偏光フィルタを介して入射される第１受光素子の受光信号と、偏光フィルタを介さないで入射される前記第２受光素子の受光信号とを入力し、前記第１受光素子の受光信号と前記第２受光素子の受光信号の強度によって求まる偏光解消度に基づいて火災の有無を判断するようにしたので、簡易な手段で確実に火災の有無を判断することができる。  In the present invention, the light receiving signal of the first light receiving element that is incident through the second polarizing filter and the light receiving signal of the second light receiving element that is incident without passing through the polarizing filter are input to the fire determining unit. Since the presence or absence of fire is determined based on the degree of depolarization determined by the intensity of the light reception signal of the first light receiving element and the light reception signal of the second light receiving element, the presence or absence of fire is reliably determined by simple means can do.

本発明の一実施の形態に係る煙感知器の断面図であり、図３の矢視Ａ−Ａ線に沿う断面図である。It is sectional drawing of the smoke detector which concerns on one embodiment of this invention, and is sectional drawing which follows the arrow AA line of FIG.本発明の一実施の形態に係る煙感知器の側面図である。It is a side view of the smoke detector which concerns on one embodiment of this invention.本発明の一実施の形態に係る煙感知器の正面（設置状態で下面）図である。It is a front (lower surface in an installation state) figure of the smoke detector which concerns on one embodiment of this invention.本発明の一実施の形態に係る煙感知器の斜視図である。It is a perspective view of the smoke detector which concerns on one embodiment of this invention.本発明の一実施の形態に係る煙感知器の正面カバーを外した状態の図である。It is a figure of the state which removed the front cover of the smoke detector which concerns on one embodiment of this invention.本発明の一実施の形態に係る煙感知器の回路ブロック図である。It is a circuit block diagram of the smoke detector which concerns on one embodiment of this invention.本発明の一実施の形態に係る煙感知器の動作説明図であり、図７（ｂ）が正面図、図７（ａ）が図７（ｂ）の矢視Ａ−Ａ線に沿う断面図である。It is operation | movement explanatory drawing of the smoke detector which concerns on one embodiment of this invention, FIG.7 (b) is a front view, FIG.7 (a) is sectional drawing which follows the arrow AA line of FIG.7 (b). It is.本発明の一実施の形態に係る煙感知器の他の態様の説明図である。It is explanatory drawing of the other aspect of the smoke detector which concerns on one embodiment of this invention.本発明の一実施の形態に係る煙感知器の他の態様の説明図である。It is explanatory drawing of the other aspect of the smoke detector which concerns on one embodiment of this invention.

本発明の一実施の形態に係る煙感知器を図１〜図７に基づいて説明する。
本実施の形態の煙感知器１は、内部に光学台３を有し外形が扁平な円柱状の筐体５と、光学台３に設置されて筐体５の外部の検煙部５０（図７参照）に向けて照射光を発光する発光素子７と、光学台３に設置されて発光部からの照射光が検煙部５０に存在する粒子によって生じる散乱光を受光する第１受光素子９及び第２受光素子１１と、発光素子７から照射される光と第１受光素子９に入射する光を偏光する偏光フィルタ１３と、第１受光素子９及び第２受光素子１１によって受光した受光信号に基づいて火災の有無を判断する火災判断部１５等が実装されるＰＣ板１７とを備えている。
各構成をさらに詳細に説明する。A smoke detector according to an embodiment of the present invention will be described with reference to FIGS.
The smoke detector 1 of the present embodiment includes acylindrical casing 5 having anoptical bench 3 inside and a flat outer shape, and a smoke detector 50 (see FIG. 7), and a firstlight receiving element 9 which is installed on theoptical bench 3 and receives scattered light generated by particles existing in thesmoke detecting unit 50. And the secondlight receiving element 11, thepolarization filter 13 that polarizes the light emitted from thelight emitting element 7 and the light incident on the firstlight receiving element 9, and the light receiving signal received by the firstlight receiving element 9 and the secondlight receiving element 11. And aPC board 17 on which afire determination unit 15 and the like for determining the presence or absence of a fire are mounted.
Each configuration will be described in more detail.

＜筐体＞
筐体５は、外形が扁平な円柱状をしており、設置状態で下面となる部分には円形の正面カバー１９を備えている。正面カバー１９の中央部には、図３、図４に示されるように、円形の３つの開口部が形成されている。３つの開口部は、正面カバー１９の中央部に設けられた発光用開口部２１と、発光用開口部２１を挟んで対称位置に設けられた第１受光用開口部２３と、第２受光用開口部２５である。
筐体５の内部には光学台３が設けられており、光学台３には発光素子７、第１受光素子９及び第２受光素子１１等の光学系部品が設置されている。<Case>
Thecasing 5 has a cylindrical shape with a flat outer shape, and acircular front cover 19 is provided on a portion that becomes a lower surface in the installed state. As shown in FIGS. 3 and 4, three circular openings are formed in the center of thefront cover 19. The three openings are a light emitting opening 21 provided at the center of thefront cover 19, a first light receiving opening 23 provided at a symmetrical position across the light emitting opening 21, and a second light receiving opening.Opening 25.
Anoptical bench 3 is provided inside thehousing 5, and optical parts such as alight emitting element 7, a firstlight receiving element 9, and a secondlight receiving element 11 are installed on theoptical bench 3.

＜発光素子＞
発光素子７は、赤外ＬＥＤによって構成され、光学台３の略中央に１つ配置され、検煙部５０に対して赤外線をパルス発光する。発光素子７の発光部は、正面カバー１９の中央に設けられた発光用開口部２１に対向配置されている。
発光素子７は、煙感知器１を天井面等に設置した状態においてその光軸が真下に向くように配置されている。<Light emitting element>
Thelight emitting element 7 is composed of an infrared LED, and onelight emitting element 7 is arranged at the approximate center of theoptical bench 3 and emits infrared light to thesmoke detector 50 in a pulsed manner. The light emitting part of thelight emitting element 7 is disposed opposite to thelight emitting opening 21 provided in the center of thefront cover 19.
Thelight emitting element 7 is arranged so that the optical axis thereof is directed directly downward when the smoke detector 1 is installed on a ceiling surface or the like.

＜受光素子＞
受光素子は、第１受光素子９と第２受光素子１１の２つの受光素子から構成されている。第１受光素子９と第２受光素子１１は、発光素子７を挟んで対称位置に配置されている。第１受光素子９と第２受光素子１１を対称位置に配置したのは、発光素子７によって照射された光が検煙空間を浮遊する散乱体３３（図７参照）で散乱した散乱光の光路が第１受光素子９と第２受光素子１１で等しくなるようにするためである。したがって、前記光路が等しくなる配置であれば、前記のようは対称配置でなくてもよい。<Light receiving element>
The light receiving element includes two light receiving elements, a firstlight receiving element 9 and a secondlight receiving element 11. The firstlight receiving element 9 and the secondlight receiving element 11 are arranged at symmetrical positions with thelight emitting element 7 interposed therebetween. The firstlight receiving element 9 and the secondlight receiving element 11 are arranged at symmetrical positions because the light irradiated by thelight emitting element 7 is an optical path of the scattered light scattered by the scatterer 33 (see FIG. 7) floating in the smoke detection space. This is because the firstlight receiving element 9 and the secondlight receiving element 11 are equal. Therefore, as long as the optical paths are the same, the above-described configuration may not be symmetrical.

第１受光素子９の受光部は、正面カバー１９に設けられた第１受光用開口部２３に対向配置され、第２受光素子１１の受光部は、正面カバー１９に設けられた第２受光用開口部２５に対向配置されている。
第１受光素子９及び第２受光素子１１は、煙感知器１を天井面等に設置した状態においてその光軸が真下に向くように配置されている。The light receiving part of the firstlight receiving element 9 is disposed opposite to the firstlight receiving opening 23 provided in thefront cover 19, and the light receiving part of the secondlight receiving element 11 is provided for the second light receiving provided in thefront cover 19. Opposed to theopening 25.
The 1stlight receiving element 9 and the 2ndlight receiving element 11 are arrange | positioned so that the optical axis may face right below in the state which installed the smoke detector 1 in the ceiling surface etc.

発光素子７と第１受光素子９及び第２受光素子１１を隣接させ、しかもこれらの光軸を前記設置した状態で真下を向くように配置しているので、これら発光素子７と第１受光素子９及び第２受光素子１１を中央部に集約することができ、煙感知器１を小型化できる。  Since thelight emitting element 7, the firstlight receiving element 9, and the secondlight receiving element 11 are adjacent to each other, and these optical axes are arranged so as to face right below in the installed state, thelight emitting element 7 and the first light receiving element are arranged. 9 and the secondlight receiving element 11 can be concentrated in the center, and the smoke detector 1 can be miniaturized.

＜偏光フィルタ＞
偏光フィルタ１３は、光の振動方向のうち一方向の成分だけを透過する性質を有するフィルタである。偏光フィルタ１３は、図１に示されるように、正面カバー１９の内側に設置されている。そして、図５に示すように、発光素子７から照射される光と、第１受光素子９に受光される光が透過するように配置されている。つまり、本実施の形態では、発光素子７から検煙部５０に照射される光と第１受光素子９に入射する光が１つの偏光フィルタ１３を通過するように構成されている。そのため、発光素子７と第１受光素子９に各々別の偏光フィルタ１３を設けた場合に比較して、偏光フィルタ１３の個体差がないので、その個体差に起因する誤差がなく、正確な検知が可能である。
なお、発光素子７と第１受光素子９に各々別の偏光フィルタ１３を設ける場合を排除するものではない。もっとも、発光素子７の前面に第１の偏光フィルタ１３を設け、第１受光素子９の前面に第２の偏光フィルタ（図示せず）を設ける場合には、それぞれの偏光方向を同一にする。<Polarizing filter>
Thepolarizing filter 13 is a filter having a property of transmitting only a component in one direction among the vibration directions of light. Thepolarizing filter 13 is installed inside thefront cover 19 as shown in FIG. Then, as shown in FIG. 5, the light emitted from thelight emitting element 7 and the light received by the firstlight receiving element 9 are transmitted. That is, in the present embodiment, the light emitted from thelight emitting element 7 to thesmoke detector 50 and the light incident on the firstlight receiving element 9 are configured to pass through onepolarizing filter 13. Therefore, there is no individual difference between the polarization filters 13 as compared with the case where thelight emitting element 7 and the firstlight receiving element 9 are provided with different polarization filters 13, respectively. Is possible.
Note that the case where separatepolarizing filters 13 are provided for thelight emitting element 7 and the firstlight receiving element 9 is not excluded. However, when the firstpolarizing filter 13 is provided on the front surface of thelight emitting element 7 and the second polarizing filter (not shown) is provided on the front surface of the firstlight receiving element 9, the polarization directions of the firstpolarizing filter 13 are the same.

＜ＰＣ板＞
ＰＣ板１７には、図６の回路ブロック図に示すように、発光素子７を駆動する発光制御部２７と、第１受光素子９及び第２受光素子１１の受光信号を増幅する増幅回路２９と、各種の制御を行う制御部３１とを備えている。制御部３１はＣＰＵが所定のプログラムを実行することで各種の機能、例えば火災判断部１５を実現している。
火災判断部１５は、第１受光素子９および第２受光素子１１のそれぞれの受光信号を増幅した検出信号を、Ａ／Ｄ変換して各検出レベルの比を求めることによって、偏光解消度を演算し、この偏光解消度が所定範囲内にあるかどうかによって火災の有無を判断する。
制御部３１は、火災判断部１５が火災と判断すると、火災信号を図示しない火災受信機に出力する。<PC board>
As shown in the circuit block diagram of FIG. 6, thePC board 17 includes a lightemission control unit 27 that drives thelight emitting element 7, and anamplification circuit 29 that amplifies the light reception signals of the firstlight receiving element 9 and the secondlight receiving element 11. And acontrol unit 31 that performs various controls. Thecontrol part 31 implement | achieves various functions, for example, thefire determination part 15, when CPU runs a predetermined program.
Thefire determination unit 15 calculates the degree of depolarization by A / D converting the detection signals obtained by amplifying the light reception signals of the firstlight receiving element 9 and the secondlight receiving element 11 to obtain the ratio of each detection level. Whether or not there is a fire is determined based on whether the degree of depolarization is within a predetermined range.
When thefire determination unit 15 determines that a fire has occurred, thecontrol unit 31 outputs a fire signal to a fire receiver (not shown).

ここで、偏光解消度について説明する。発光素子７から偏光フィルタ１３を透過して検煙部５０に照射された光が、検煙部５０に存在する粒子（散乱体３３）によって散乱されると、散乱体３３が球形の場合には偏光フィルタ１３を透過した発光素子７の照射光と散乱体３３により生じた散乱光との偏光方向が変わらないが、散乱体３３が非球形の場合にはその偏光方向が様々に変わる。この散乱体３３で偏光が変わる割合を偏光解消度いう。つまり、偏光解消度が小さい、あるいは無いということは散乱体３３が煙粒子のような球形であることを意味しており、偏光解消度が大きいということは、散乱体３３が塵埃などのような非球形であることを意味している。  Here, the degree of depolarization will be described. If the light transmitted from thelight emitting element 7 through thepolarizing filter 13 and applied to thesmoke detector 50 is scattered by particles (scatterer 33) existing in thesmoke detector 50, thescatterer 33 is spherical. Although the polarization direction of the irradiation light of thelight emitting element 7 that has passed through thepolarizing filter 13 and the scattered light generated by thescatterer 33 does not change, when thescatterer 33 is aspherical, the polarization direction changes variously. The rate at which the polarization changes by thescatterer 33 is called the degree of depolarization. That is, when the degree of depolarization is small or absent, it means that thescatterer 33 is spherical like smoke particles, and when the degree of depolarization is large, thescatterer 33 is like dust or the like. It means non-spherical.

例えば、煙の場合には偏光解消度は約１０％であり、杉花粉などの塵埃は約３０％である。この場合を具体例に挙げて、単純化して説明すると以下のようになる。仮に散乱体が煙粒子の場合、偏光解消度が１０％とすれば、第２受光素子１１に入射する光の強度を１００とすれば、第１受光素子９に入射する光の強度は９０になり、これらの第１受光素子９と第２受光素子１１との各受光信号の出力比は０．９になる。
他方、散乱体が塵埃の場合には、第２受光素子１１に入射する光の強度を１００とすれば、第１受光素子９に入射する光の強度は７０になり、これらの第１受光素子９と第２受光素子１１との各受光信号の出力比は０．７になる。したがって、例えば閾値を０．８〜０．８５程度に設定して、火災判断部１５は、この閾値を超えた場合には火災であると判断し、閾値未満であれば火災でないと判断するようにすれば、簡易でありながらも確実に火災であるかどうかを判断できる。For example, in the case of smoke, the degree of depolarization is about 10%, and dust such as cedar pollen is about 30%. Taking this case as a specific example, a simplified description is as follows. If the scatterer is smoke particles, if the degree of depolarization is 10%, the intensity of light incident on the secondlight receiving element 9 is 90 if the intensity of light incident on the secondlight receiving element 11 is 100. Thus, the output ratio of the respective light receiving signals of the firstlight receiving element 9 and the secondlight receiving element 11 is 0.9.
On the other hand, when the scatterer is dust, assuming that the intensity of light incident on the secondlight receiving element 11 is 100, the intensity of light incident on the firstlight receiving element 9 is 70, and these first light receiving elements The output ratio of each light reception signal between 9 and the secondlight receiving element 11 is 0.7. Therefore, for example, the threshold value is set to about 0.8 to 0.85, and thefire determination unit 15 determines that a fire occurs when the threshold value is exceeded, and determines that the fire does not occur when the threshold value is less than the threshold value. If it is, it can be judged whether it is a fire reliably although it is simple.

上記のように構成された本実施の形態の動作を、図７に基づいて、検煙部５０に存在する散乱体３３が煙の場合（火災の場合）と、塵埃の場合（火災でない場合）について説明する。
＜散乱体が煙の場合＞
発光制御部２７の制御信号に基づいて発光素子７がパルス発光する。発光素子７で発光した光は偏光フィルタ１３を透過し、透過の際に偏光される。偏光された透過光が煙によって散乱されるが、この場合には煙粒子が略球形であるので偏光の向きが変わらない。この偏光の向きが変わらない散乱光は偏光フィルタ１３を透過して第１受光素子９に入射すると共に偏光フィルタ１３を透過することなく第２受光素子１１に入射する。第１受光素子９に入射する際、偏光フィルタ１３を透過するが、散乱によって偏光の向きに変化がないので、偏光フィルタ１３を通過して第１受光素子９に入射する光の強度は、第２受光素子１１に入射する光の強度とほぼ同じである。したがって、この場合、火災判断部１５は各受光信号の検出レベルの比を演算し、それが閾値を超えているとして、火災であると判断する。The operation of the present embodiment configured as described above is based on FIG. 7 when thescatterer 33 present in thesmoke detector 50 is smoke (in the case of fire) and dust (in the case of no fire). Will be described.
<When the scatterer is smoke>
Based on the control signal of the lightemission control unit 27, thelight emitting element 7 emits pulses. The light emitted from thelight emitting element 7 is transmitted through thepolarizing filter 13 and is polarized upon transmission. Polarized transmitted light is scattered by smoke, but in this case, the direction of polarization does not change because the smoke particles are substantially spherical. The scattered light whose polarization direction does not change passes through thepolarizing filter 13 and enters the firstlight receiving element 9 and enters the secondlight receiving element 11 without passing through thepolarizing filter 13. When entering the firstlight receiving element 9, it passes through thepolarizing filter 13, but since the direction of polarization does not change due to scattering, the intensity of the light passing through thepolarizing filter 13 and entering the firstlight receiving element 9 is The intensity of light incident on the twolight receiving elements 11 is substantially the same. Therefore, in this case, thefire determination unit 15 calculates the ratio of the detection levels of the respective light reception signals, and determines that it is a fire because it exceeds the threshold value.

＜散乱体が塵埃の場合＞
発光素子７で発光した光は偏光フィルタ１３を透過し、偏光された透過光が塵埃によって散乱されると、偏光の向きが様々な向きに変わり偏光が解消される。この偏光が解消された散乱光は、偏光フィルタ１３を透過して第１受光素子９に入射するが、偏光フィルタ１３を透過できるのは偏光フィルタ１３の偏光の向きと同一の向きの振動をする光のみであるため、その強度が弱くなる。他方、第２受光素子１１に入射する光の強度は、偏光フィルタ１３を透過しないので、散乱光がそのまま入射する。したがって、この場合、第１受光素子９と第２受光素子１１の受光強度に差が生じる。そして、火災判断部１５は、各受光信号の検出レベルの比を演算し、それが閾値未満であるとして、火災でないと判断する。<When the scatterer is dust>
The light emitted from thelight emitting element 7 is transmitted through thepolarizing filter 13, and when the polarized transmitted light is scattered by dust, the direction of polarized light changes to various directions and the polarized light is eliminated. The scattered light whose polarization has been eliminated passes through thepolarizing filter 13 and enters the firstlight receiving element 9, but can pass through thepolarizing filter 13 and vibrates in the same direction as the polarization direction of thepolarizing filter 13. Since it is only light, its intensity is weakened. On the other hand, since the intensity of the light incident on the secondlight receiving element 11 does not pass through thepolarizing filter 13, the scattered light is incident as it is. Therefore, in this case, a difference occurs in the light receiving intensity between the firstlight receiving element 9 and the secondlight receiving element 11. And thefire judgment part 15 calculates ratio of the detection level of each received light signal, and judges that it is not a fire, if it is less than a threshold value.

以上のように、本実施の形態の煙感知器１によれば、最も区別したい対象である塵埃などと煙を確実にしかも簡易な構成で区別でき、火災の有無を正確に判別できる。
また、本実施の形態では、前述したように、発光素子７から照射される光と第１受光素子９に入射する光が共通の偏光フィルタ１３を透過するようにしたので、偏光フィルタ１３の個体差が生ぜず、より正確な検知ができる。As described above, according to the smoke detector 1 of the present embodiment, dust or the like, which is the object most desired to be distinguished, can be reliably distinguished with a simple configuration, and the presence or absence of a fire can be accurately determined.
In the present embodiment, as described above, the light irradiated from thelight emitting element 7 and the light incident on the firstlight receiving element 9 are transmitted through the commonpolarizing filter 13. There is no difference, and more accurate detection is possible.

もっとも、図７の破線矢印で示すように発光素子７が赤外ＬＥＤの場合、レーザ光ほど直進性がないため、発光素子７から照射された光が偏光フィルタ１３によって内部反射され、この内部反射した光が第１受光素子９に入射することが考えられる。つまり、第１受光素子９に入射する光は、散乱体３３によって散乱された散乱光と内部反射光との総和ということになる。そこで、内部反射光の分を補正するようにするのが好ましい。このためには、火災判断部１５において、第１受光素子９の受光量から内部反射による受光量を減算するようにすればよい。内部反射の受光量は、検煙部に散乱体３３が存在しない（無煙時の）第１受光素子９の受光信号から求められる。つまり、火災判断部１５に補正手段を設けるようにすればよい。  However, when thelight emitting element 7 is an infrared LED as indicated by the broken line arrow in FIG. 7, the light emitted from thelight emitting element 7 is internally reflected by thepolarizing filter 13 because it is not as straight as laser light. It is conceivable that the received light enters the firstlight receiving element 9. That is, the light incident on the firstlight receiving element 9 is the sum of the scattered light scattered by thescatterer 33 and the internally reflected light. Therefore, it is preferable to correct the amount of internally reflected light. For this purpose, thefire determination unit 15 may subtract the amount of light received by internal reflection from the amount of light received by the firstlight receiving element 9. The amount of light received by the internal reflection is obtained from the light reception signal of the firstlight receiving element 9 in which thescatterer 33 does not exist in the smoke detector (when no smoke is present). That is, the correction means may be provided in thefire determination unit 15.

＜発光素子と第１受光素子及び第２受光素子の配置＞
上記の実施の形態においては、発光素子７と第１受光素子９及び第２受光素子１１は、図１、図３に示されるように、発光素子７を中心にして、発光素子７の両側に第１受光素子９と第２受光素子１１を発光素子７に対して対称位置に配置した。
このような配置によって、上述したように、各素子を煙感知器１の中央部に集約することができ、煙感知器１の小型化が実現されている。
小型化を実現しているのは、発光素子７と第１受光素子９及び第２受光素子１１の光軸が平行になるように、つまり全ての素子を近接配置しているからであり、その場合の他の態様として、例えば図８に示すように、煙感知器１を天井面等に設置した状態で、各素子の光軸が真下を向かないような場合であってもよい。<Arrangement of light emitting element, first light receiving element, and second light receiving element>
In the above embodiment, thelight emitting element 7, the firstlight receiving element 9, and the secondlight receiving element 11 are arranged on both sides of thelight emitting element 7 with thelight emitting element 7 as the center, as shown in FIGS. The firstlight receiving element 9 and the secondlight receiving element 11 are arranged symmetrically with respect to thelight emitting element 7.
With such an arrangement, as described above, each element can be concentrated in the central portion of the smoke detector 1, and the smoke detector 1 can be downsized.
The downsizing is realized because the light axes of thelight emitting element 7, the firstlight receiving element 9, and the secondlight receiving element 11 are parallel, that is, all the elements are arranged close to each other. As another aspect of the case, for example, as shown in FIG. 8, the smoke detector 1 may be installed on the ceiling surface or the like, and the optical axis of each element may not be directed downward.

また、上記の例では、発光素子７と第１受光素子９及び第２受光素子１１の光軸が平行の場合であったが、図９に示すように、発光素子７の光軸を設置状態で真下に向け、その両隣に発光素子７に対して対称位置に第１受光素子９、第２受光素子１１を配置し、第１受光素子９と第２受光素子１１の光軸の向きを真下にするのではなく、互いに交差する方向にしてもよい。この場合は、発光素子７と第１の受光素子９との光軸が平行ではないので、発光素子７から照射される光を偏光する第１の偏光フィルタ１３と、第１受光素子９によって受光される光を第１の偏光フィルタ１３と同一方向に偏光する第２の偏光フィルタ１３とが別々に設けられる。
もっとも、煙感知器の小型化のため、第１受光素子９と第２受光素子１１の光軸の成す角度θが鋭角になるように配置する。鋭角になるように配置することで、第１受光素子９と第２受光素子１１の距離を近づけることが可能となり、煙感知器のコンパクト化が実現できるからである。図１や図８に示した例は、第１受光素子９と第２受光素子１１の光軸の成す角度θが０度の場合であると位置づけられる。In the above example, the optical axes of thelight emitting element 7 and the firstlight receiving element 9 and the secondlight receiving element 11 are parallel. However, as shown in FIG. The firstlight receiving element 9 and the secondlight receiving element 11 are arranged symmetrically with respect to thelight emitting element 7 on both sides thereof, and the directions of the optical axes of the firstlight receiving element 9 and the secondlight receiving element 11 are directly below. The directions may be crossed with each other. In this case, since the optical axes of thelight emitting element 7 and the firstlight receiving element 9 are not parallel, the light is received by the firstpolarizing filter 13 that polarizes the light emitted from thelight emitting element 7 and the firstlight receiving element 9. The secondpolarizing filter 13 that polarizes the light to be emitted in the same direction as the firstpolarizing filter 13 is provided separately.
However, in order to reduce the size of the smoke detector, the smoke detector is arranged such that the angle θ formed by the optical axes of the firstlight receiving element 9 and the secondlight receiving element 11 is an acute angle. This is because the firstlight receiving element 9 and the secondlight receiving element 11 can be arranged closer to each other by arranging them at an acute angle, and the smoke detector can be made compact. The example shown in FIGS. 1 and 8 is positioned as the case where the angle θ formed by the optical axes of the firstlight receiving element 9 and the secondlight receiving element 11 is 0 degree.

なお、上記の実施の形態では、受光素子として第１受光素子９と第２受光素子１１の２つの受光素子を用いるようにしたが、受光素子を単一にして、受光素子の受光部に入射する光が偏光フィルタを透過するときと透過しないときを制御部３１によって間欠的に切り替えるようにしてもよい。そして、火災判断部１５は、偏光フィルタを透過して入射される受光信号と、偏光フィルタを透過しないで入射される受光信号との出力比で火災の有無を判断する。このようにすれば、偏光フィルタのみならず受光素子も共通化されるので、個体差による誤差をより少なくすることができる。  In the above embodiment, the two light receiving elements of the firstlight receiving element 9 and the secondlight receiving element 11 are used as the light receiving elements. However, the light receiving elements are single and incident on the light receiving portion of the light receiving element. Thecontrol unit 31 may intermittently switch between when the light to be transmitted is transmitted through the polarizing filter and when it is not transmitted. And thefire judgment part 15 judges the presence or absence of a fire with the output ratio of the light reception signal which permeate | transmits and transmits through a polarizing filter, and the light-receiving signal which does not permeate | transmit a polarizing filter. In this way, since not only the polarizing filter but also the light receiving element is shared, errors due to individual differences can be further reduced.

さらに、上記の実施の形態では、発光素子７がＬＥＤである例を示したが、ＬＥＤの代わりに、レーザダイオードなどのレーザ光源を使用してもよい。このようにすれば、レーザ光源は、それ自体が単一方向に偏光された光を発するので、発光素子７に偏光フィルタ１３が不要とできる。  Furthermore, in the above embodiment, an example in which thelight emitting element 7 is an LED has been described. However, a laser light source such as a laser diode may be used instead of the LED. In this way, the laser light source itself emits light polarized in a single direction, so that the light-emittingelement 7 does not require thepolarizing filter 13.

１ 煙感知器
３ 光学台
５ 筐体
７ 発光素子
９ 第１受光素子
１１ 第２受光素子
１３ 偏光フィルタ
１５ 火災判断部
１７ ＰＣ板
１９ 正面カバー
２１ 発光用開口部
２３ 第１受光用開口部
２５ 第２受光用開口部
２７ 発光制御部
２９ 増幅回路
３１ 制御部
３３ 散乱体
５０ 検煙部DESCRIPTION OF SYMBOLS 1Smoke detector 3Optical stand 5Case 7Light emitting element 9 1stlight receiving element 11 2ndlight receiving element 13Polarizing filter 15Fire judgment part 17PC board 19Front cover 21Light emission opening 23 1stlight reception opening 25 1st 2 Opening forlight reception 27 Light emission controlpart 29Amplifying circuit 31Control part 33Scattering body 50 Smoke detection part

Claims (5)

Translated fromJapanese

筐体と、前記筐体の内部に配置され、前記筐体の外部の検煙部に向けて照射光を発光する発光部と、前記筐体の内部に配置され、前記発光部からの照射光が前記検煙部に存在する散乱体によって生じる散乱光を受光し、散乱光の受光量に基づいて受光信号を出力する受光部と、該受光部によって出力された受光信号に基づいて火災の有無を判断する火災判断部とを備える煙感知器において、
前記発光部は発光素子で構成され、前記受光部は第１受光素子と第２受光素子によって構成され、前記発光素子から照射される光を偏光する第１偏光フィルタと、前記受光素子によって受光される光を前記第１偏光フィルタと同一方向に偏光する第２偏光フィルタとを備え、前記火災判断部は、前記第２偏光フィルタを透過して入射される前記第１受光素子の受光信号と、前記第２偏光フィルタを透過しないで入射される前記第２受光素子の受光信号との出力比に基づいて火災の有無を判断することを特徴とする煙感知器。A housing, a light emitting unit disposed inside the housing and emitting irradiation light toward a smoke detection unit outside the housing, and a light emitting unit disposed inside the housing and emitted from the light emitting unit Receives a scattered light generated by a scatterer existing in the smoke detector, and outputs a light reception signal based on the amount of scattered light received, and whether there is a fire based on the light reception signal output by the light reception unit In a smoke detector comprising a fire determination unit for determining
The light emitting unit is composed of a light emitting element, the light receiving unit is composed of a first light receiving element and a second light receiving element, and is received by the light receiving element and a first polarizing filter that polarizes light emitted from the light emitting element. A second polarizing filter that polarizes light in the same direction as the first polarizing filter, and the fire determination unit transmits a light received by the first light receiving element through the second polarizing filter; A smoke detector, wherein the presence or absence of a fire is determined based on an output ratio to a light reception signal of the second light receiving element that is incident without passing through the second polarizing filter. 前記第１偏光フィルタと前記第２偏光フィルタを単一の偏光フィルタで構成したことを特徴とする請求項１記載の煙感知器。  The smoke detector according to claim 1, wherein the first polarizing filter and the second polarizing filter are configured by a single polarizing filter. 前記第１受光素子の受光信号から、前記第２偏光フィルタに内部反射して入射される分を補正する補正手段を備えたことを特徴とする請求項１又は２に記載の煙感知器。  3. The smoke detector according to claim 1, further comprising a correcting unit that corrects an amount of light that is internally reflected and incident on the second polarizing filter from a light reception signal of the first light receiving element. 4. 筐体と、前記筐体の内部に配置され、前記筐体の外部の検煙部に向けて照射光を発光する発光部と、前記筐体の内部に配置され、前記発光部からの照射光が前記検煙部に存在する散乱体によって生じる散乱光を受光し、散乱光の受光量に基づいて受光信号を出力する受光部と、該受光部によって出力された受光信号に基づいて火災の有無を判断する火災判断部とを備える煙感知器において、
前記発光部は発光素子で構成され、前記受光部は受光素子で構成され、前記発光素子から照射される光を偏光する第１偏光フィルタと、前記受光素子によって受光される光を前記第１偏光フィルタと同一方向に偏光する第２偏光フィルタとを備え、前記発光部は、前記第１偏光フィルタにより偏光された光を前記検煙部に発して、前記受光部は、前記第２偏光フィルタにより偏光された散乱光または偏光されない散乱光のいずれか一方を受光するもので構成され、前記受光部が前記第２偏光フィルタにより偏光された散乱光を受光するかまたは偏光されない散乱光を受光するかを切替させる制御部を有し、前記火災判断部は、前記第２偏光フィルタを透過して入射される受光信号と、前記第２偏光フィルタを透過しないで入射される受光信号との出力比に基づいて火災の有無を判断することを特徴とする煙感知器。A housing, a light emitting unit disposed inside the housing and emitting irradiation light toward a smoke detection unit outside the housing, and a light emitting unit disposed inside the housing and emitted from the light emitting unit Receives a scattered light generated by a scatterer existing in the smoke detector, and outputs a light reception signal based on the amount of scattered light received, and whether there is a fire based on the light reception signal output by the light reception unit In a smoke detector comprising a fire determination unit for determining
The light emitting unit is composed of a light emitting element, the light receiving unit is composed of a light receiving element, and a first polarizing filter that polarizes light emitted from the light emitting element, and light received by the light receiving element is the first polarized light. A second polarizing filter that polarizes in the same direction as the filter, the light emitting unit emits light polarized by the first polarizing filter to the smoke detecting unit, and the light receiving unit is formed by the second polarizing filter. Whether it is configured to receive either polarized scattered light or non-polarized scattered light, and whether the light receiving unit receives scattered light polarized by the second polarizing filter or unscattered scattered light. The fire determination unit includes a light receiving signal that is transmitted through the second polarizing filter and a light receiving signal that is incident without passing through the second polarizing filter. Smoke detector, characterized in that to determine the presence or absence of fire based on the output ratio. 筐体と、前記筐体の内部に配置され、前記筐体の外部の検煙部に向けて照射光を発光する発光部と、前記筐体の内部に配置され、前記発光部からの照射光が前記検煙部に存在する散乱体によって生じる散乱光を受光し、散乱光の受光量に基づいて受光信号を出力する受光部と、該受光部によって出力された受光信号に基づいて火災の有無を判断する火災判断部とを備える煙感知器において、
前記発光部は単一方向に偏光された光を発するレーザ素子で構成され、前記受光部は第１受光素子と第２受光素子によって構成され、前記第１受光素子によって受光される光を前記レーザ素子の偏光された光と同一方向に偏光する偏光フィルタを備え、
前記火災判断部は、前記偏光フィルタを透過して入射される前記第１受光素子の受光信号と、前記偏光フィルタを透過しないで入射される前記第２受光素子の受光信号との出力比に基づいて火災の有無を判断することを特徴とする煙感知器。A housing, a light emitting unit disposed inside the housing and emitting irradiation light toward a smoke detection unit outside the housing, and a light emitting unit disposed inside the housing and emitted from the light emitting unit Receives a scattered light generated by a scatterer existing in the smoke detector, and outputs a light reception signal based on the amount of scattered light received, and whether there is a fire based on the light reception signal output by the light reception unit In a smoke detector comprising a fire determination unit for determining
The light emitting unit is configured by a laser element that emits light polarized in a single direction, the light receiving unit is configured by a first light receiving element and a second light receiving element, and the light received by the first light receiving element is the laser. A polarizing filter that polarizes in the same direction as the polarized light of the element;
The fire determining unit is based on an output ratio between a light reception signal of the first light receiving element that is transmitted through the polarizing filter and a light reception signal of the second light receiving element that is incident without passing through the polarizing filter. A smoke detector characterized by the presence or absence of a fire.

Images