JP2006146947A - Fire detector and method for compensating worn-out of fire detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fire detector of which the reliability of a worn-out compensation function can be enhanced by enhancing detection accuracy of a worn-out state of a translucent window arranged in front of a detection sensor and a method for compensating worn-out of the fire detector. <P>SOLUTION: The fire detector is constituted of: a sensor part SEN which is arranged in the translucent window 11, detects infrared energy and outputs the infrared energy by converting it into an electric signal; a filter part FLT which passes only a signal component Aa of a predetermined frequency band from a detection signal Sa of the sensor part SENS; a signal amplification part AMP which amplifies the signal component Aa; a signal processing part PRO which carries out fire judgment processing and worn-out compensation processing based on amplification output (light receiving output) of the signal amplification part AMP; an amplification control part 70 which changes and controls an amplification factor of the signal amplification part AMP according to a worn-out state of the translucent window 11; and a test light source control part 80 which performs emission drive of a test light source LGT with luminous energy set according to the worn-out state of the translucent window 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fire detector that detects the occurrence of a fire by detecting the radiant energy obtained by observing a flame, and in particular, a translucent light provided in front of a detection sensor that performs a fire determination. TECHNICAL FIELD The present invention relates to a fire detector having an automatic compensation function for dirty windows and a method for compensating for damage of fire detectors.

2. Description of the Related Art Conventionally, various facilities such as lighting lights, fire monitoring equipment, fire extinguishing equipment, and evacuation guidance equipment are installed in tunnels for vehicles, railways, and the like in order to ensure traffic safety.
In particular, fire detectors, which are the main equipment of fire monitoring equipment, detect the fire of a vehicle in the tunnel, and the prospects in the tunnel are effective for the purpose of promptly notifying the tunnel manager and the driver of the vehicle. They are arranged on the wall surface at a predetermined interval, for example, at an interval of 25 m.

Here, an example of a conventional fire detector installed in the tunnel will be described with reference to the drawings.
FIG. 16 is a schematic configuration diagram of a conventional fire detector for tunnels that is generally used. In addition, the structure of such a fire detector is described in Unexamined-Japanese-Patent No. 7-175986 (patent document 1), for example.

  As shown in FIGS. 16A and 16B, the fire detector 100 generally includes a main body case 101, an upper cover 102 attached to the main body case 101, and a tunnel at a substantially central portion of the upper cover 102. A dome-shaped light-transmitting light-receiving glass 103 assembled so as to protrude in the inner direction, and a light-receiving element (detection sensor) 104a that is housed in the light-receiving glass 103 and detects radiation emitted from a flame, 104b, a circuit board 105 on which an amplification circuit that amplifies signals detected by the light receiving elements 104a and 104b, a signal processing circuit that performs fire determination, and the like are mounted, and the light receiving glass 103 is contaminated. Domed globe 1 in which check lamps (test light sources) 106a and 106b for projecting test light CK for detecting a state and the like are housed 7a, and it is configured to have a 107 b, a.

In such a configuration, each of the light receiving elements 104a and 104b has a center line LC perpendicular to the tunnel inner wall surface TS as a boundary as shown in FIG. The detection area is set so as to individually monitor the area AR on the right side of the drawing.
Here, in the fire detector 100, the detection area set by the light receiving elements 104a and 104b housed in the light receiving glass 103 is set large with respect to the longitudinal direction of the tunnel (left and right in the drawing) and is adjacent. In order to monitor efficiently without generating a non-monitoring area up to the arrangement position of the similar fire detector 100 installed at the same time, the light receiving elements 104a and 104b have an angle of approximately 45 degrees with respect to the tunnel inner wall surface TS. It is installed to have. Therefore, the dome-shaped light receiving glass 101 has a structure that inevitably protrudes greatly into the tunnel.

  Normally, when the fire detector 100 is installed in a tunnel, it is housed in a detector box (not shown) and attached to a wall or the like with the light receiving glass 103 and the globes 107a and 107b exposed to the outside. It is done. Here, in the case of the embedded type, the detector box front surface is installed so as to substantially coincide with the tunnel inner wall surface TS, and in the case of the exposed type, the detector box rear surface substantially coincides with the tunnel inner wall surface TS. Installed.

Next, the adhesion of dirt to the fire detector having the above-described configuration will be described with reference to the drawings.
FIG. 17 is a schematic cross-sectional view showing the relationship between the air flow generated in the tunnel and the state of dirt adhering to the fire detector in the prior art.
Generally, in a tunnel for a vehicle (road tunnel), an airflow C or a vehicle that flows predominantly at about 2 m to 10 m / s in one direction in the longitudinal direction of the tunnel due to running of the vehicle, ventilation of a jet fan, or the like. It is known that there are irregular turbulent airflows and the like that occur during passage, and these generate airflows in various directions in the tunnel. Therefore, as shown in FIG. 17, the light receiving glass 103 provided so as to protrude into the tunnel is exposed to an airflow C generated in the tunnel.

  Here, various substances that cause dirt (hereinafter collectively referred to as “soil-causing substances”) such as smoke, dust, earth and sand, chemical substances such as antifreezing agents, etc. discharged from vehicles float in the tunnel. Therefore, these substances fly on the air current, and directly collide with the air current upstream side of the dome-shaped light receiving glass 103 and adhere as dirt DST. In addition, although dirt adheres other than the upstream side of the airflow of the light receiving glass 103, the degree of dirt is about a fraction of that of the upstream side where the airflow directly collides. Such dirt DST on the light receiving glass 103 reduces the light reception amount of the light receiving elements 104a and 104b housed therein, thereby lowering the detection sensitivity. Therefore, in order to maintain the performance of the fire detector 100 Has the problem of having to perform frequent cleaning operations.

  Here, as a method for knowing the timing of the cleaning work, for example, as shown in FIG. 16, test light CK for detecting the dirt state of the light receiving glass 103 is provided around the dome-shaped light receiving glass 103. Some of them have a function of diagnosing and notifying the timing of the cleaning work by arranging check lamps 106a and 106b to emit and periodically detecting the dirt state (degree of fouling) of the light receiving glass 103. In addition, it is also known that a reduction in detection sensitivity is automatically compensated by electrical processing etc. (fouling compensation processing) and has a fouling compensation function that reduces the frequency of cleaning work, and has been devised to extend the cleaning cycle. Yes. Note that methods for avoiding the influence of contamination by the contamination compensation processing are described in detail, for example, in JP-A-6-325274 (Patent Document 2) and JP-A-5-314376 (Patent Document 3).

  As a schematic configuration of a radiation (optical) fire detector to which the above-described fouling compensation processing is applied, for example, as shown in a functional block diagram of FIG. 18, the radiation radiated from a flame FR or the like is roughly classified. A detection sensor 110 (corresponding to the light receiving elements 104a and 104b in FIGS. 16 and 17) having a pyroelectric-type light receiving element for detecting energy (particularly infrared energy), and detected and output by the detection sensor 110 From the detection signal Sp, the filter unit 120 that passes only the signal component Ap in a specific frequency band used in the flame determination process (or fire determination process) described later, and the signal component Ap that has passed through the filter unit 120 are predetermined. A preamplifier 130 that amplifies the signal level to the first stage, and a main amplifier that amplifies the output from the preamplifier 130 to a signal level suitable for flame determination processing 40, an analog-digital converter (hereinafter referred to as “A / D converter”) 150 for converting the amplified output (analog signal) Bp output from the main amplifier 140 into a digital signal, and A / D converted Based on the amplified output Bp, a signal processing unit (or a fire determination processing unit) 160 that executes a flame determination process and a test light source 170 provided apart from the detection sensor 110 (a check lamp in FIGS. 16 and 17). 106a and 106b).

  Here, in front of the detection sensor 110 (detection area side) and in front of the test light source 170 (detection sensor side), a translucent window 111 for protecting the detection sensor made of sapphire glass or the like (FIG. 16, FIG. 17) and a transparent window 112 for protecting the test light source (corresponding to the globes 107a and 107b in FIGS. 16 and 17).

  In the fire monitoring process in the fire detector having such a configuration, when the flame FR is observed by the detection sensor 110, a detection signal Sp corresponding to the radiation energy of the flame FR is output, and the filter unit 120 makes a fire determination. Only the signal component Ap in the used frequency band passes and is amplified to a predetermined signal level by the preamplifier 130 and the main amplifier 140. Further, the amplified output Bp is converted into a digital signal by the A / D converter 150 and input to the signal processing unit 160 as a light reception output, and a predetermined fire determination process is executed. That is, a fire determination process is executed based on a flame-specific signal component included in a specific frequency band.

  On the other hand, in the stain compensation processing, a test light (pseudo flame light: pseudo-flame light: from the test light source 170 to the detection sensor 110 by outputting a predetermined light emission drive signal from the signal processing unit 160 during the test operation for detecting the stain state of the light receiving glass. When CK is projected through the translucent windows 112 and 111, a detection signal Sp corresponding to (or associated with) the contamination state of the translucent window 111 is output. As in the case of the fire monitoring process described above, only the signal component Ap having a predetermined frequency band is extracted, amplified with a predetermined amplification factor, digitally converted, and input to the signal processing unit 160 as a light reception output.

  In the signal processing unit 160, the signal level of the light reception output is determined, and when the light attenuation rate of the test light CK calculated from the level change with respect to the reference value is determined to be, for example, a predetermined threshold value or more (translucency) When the transmission of the test light CK decreases due to contamination of the window 111 and the signal level of the light reception output becomes weak), for example, the preamplifier 130 is set so that the light reception output becomes a signal level that does not hinder the fire determination processing. And / or the signal amplification factor by the main amplifier 140 is changed and controlled, and the signal processing unit 160 executes processing for changing the fire determination level. As a result, even if the contamination state of the translucent window 111 has progressed, the decrease in the signal level of the received light output is compensated by electrical processing or software processing, and the detection performance as a fire detector is ensured. Therefore, the frequency of cleaning work was reduced.

  In particular, in a radiation type fire detector installed in a road tunnel as described above, since the progress of contamination is significant compared to that installed in a general environment, the detection performance can be greatly improved. It has been demanded. For this reason, the contamination detection process is set so that the fire detection function operates normally even with a very high attenuation rate of 85%, for example.

Japanese Patent Laid-Open No. 7-175986 Japanese Patent Laid-Open No. 6-325274 Japanese Patent Laid-Open No. 5-314376

However, the conventional technology as described above has the following problems.
That is, as shown in FIG. 18, the outer surface side (outside air side) of each of the translucent windows 111 and 112 arranged in front of the detection sensor 110 and the test light source 170 is outside air in which dirt-causing substances float. Since it is in an exposed state, it is in an environment where the adhesion of dirt proceeds almost simultaneously according to the airflow generated in the tunnel.

On the other hand, in the fire monitoring process of the fire detector, the fire determination process is executed based on the radiant energy from the flame FR received only through the translucent window 111 arranged in front of the detection sensor 110. .
Therefore, since the test light CK is projected to the detection sensor 110 through both the translucent windows 111 and 112 arranged in front of the detection sensor 110 and the test light source 170, the test light CK is arranged in front of the detection sensor 110. When detecting only the dirty state of the transparent window 111, it is necessary to consider the dirty state of the transparent window 112 arranged in front of the test light source 170.

  For example, as described above, in the case where the fire detection function is compensated until the light reduction rate of the translucent window 111 disposed in front of the detection sensor 110 reaches 85%, in front of the detection sensor 110. When the temporal progress of the contamination state of the translucent window 111 disposed and the translucent window 112 disposed in front of the test light source 170 is equal, the translucency disposed in front of the test light source 170 Therefore, the attenuation rate of the test light CK transmitted through both the transparent windows 111 and 112 is approximately 98% [≈97.75% = 1- (transmittance of the light-transmitting window 111 is 15%) × (transmittance of the light-transmitting window 112 is 15%)]. In this case, in order to detect the compensation limit, it is necessary to satisfactorily detect the transmission test light CK that is only about 2% higher than the non-stained state of the translucent window 111.

That is, when the signal level of the light reception output of the test light CK detected when the translucent window 111 is in a non-fouling state is, for example, 4.5 Vp-p, the signal level detected at 98% dimming Is 0.09 Vp-p, which is only 1/50, but requires an accuracy capable of sufficiently discriminating this minute signal level.
However, there is a problem that it is extremely difficult to detect such a minute signal level by clearly distinguishing it from the noise level and convert it to an accurate light attenuation rate. This is because if the received light output becomes too small (weak), it is difficult not only to accurately detect the signal level, but also to distinguish it from a no-signal state or a failure state.

  Therefore, in view of such problems, the present invention can improve the reliability of the contamination compensation function by improving the detection accuracy of the contamination state of the translucent window arranged in front of the detection sensor. The purpose is to provide a fire detector that can be used and a method for compensating for contamination of the fire detector.

  A fire detector according to a first aspect of the present invention is provided in a translucent window, converts a light energy into an electrical signal, and a predetermined fire determination based on a detection signal from the detection sensor. Fire detection means for performing processing, a detection sensor for contamination detection disposed in the translucent window, and the detection of contamination through test light projected from a predetermined test light source via the translucent window In the fire detector comprising: a contamination compensation unit that detects a contamination state of the translucent window by causing the detection sensor to detect light, and executes a predetermined contamination compensation process. The light emission energy of the test light projected from the test light source is variably controlled in accordance with the contamination state of the light window.

  That is, in the fire detector having a fouling compensation function that automatically compensates for a decrease in the fire detection function (detection sensitivity) due to fouling of the translucent window in which the detection sensor for fire determination is housed, the translucent window The emission energy (emission level) of the test light emitted from the test light source is variably changed according to the contamination state (fouling stage) of the translucent window with respect to the detection sensor for contamination detection disposed inside Settings are controlled.

  Therefore, even if the detection output of the test light by the detection sensor for contamination detection is weak due to the contamination state of the translucent window, by changing the setting to increase the emission energy of the test light source Since the contamination state of the translucent window can be detected and determined appropriately, the contamination compensation process for appropriately setting the detection sensitivity according to the contamination state of the translucent window can be executed, The fire detection function can be maintained and guaranteed.

  A fire detector according to a second aspect of the present invention is the fire detector according to the first aspect, wherein the contamination compensation means is output from the contamination detection detection sensor when the translucent window is in a non-contamination state. The test light having a predetermined light emission energy is received using the signal level of the output signal as a reference value, and the relative value of the output signal output from the contamination detection detection sensor with respect to the reference value is the predetermined light emission. It is determined whether or not it is within a predetermined threshold range corresponding to energy, and the emission energy is variably controlled based on the determination result.

  That is, when a test light having a predetermined emission energy is received, the relative value (relative output) of the output signal from the contamination detection detection sensor is within a predetermined threshold range corresponding to the predetermined emission energy. If the relative output is outside the threshold range, execute a process to increase or decrease the emission energy to change to a new emission energy, and the relative output is within the threshold range. In this case, based on the relative output, the contamination state (fouling stage) of the translucent window is determined, and a predetermined contamination compensation process corresponding to the contamination state is executed.

  Therefore, even when the signal level of the output signal from the contamination detection sensor increases or decreases due to the contamination state of the translucent window, the output from the contamination detection sensor is not contaminated (translucent window). Is treated as a relative output with the reference value as the reference value, and by comparing with the threshold range corresponding to the emission energy of the test light, appropriate emission energy is set according to the contamination state of the translucent window Therefore, the contamination state of the translucent window can be appropriately determined, and an appropriate contamination compensation process (for example, detection sensitivity change setting) according to the contamination state can be performed.

  The fire detector according to a third aspect of the present invention is the fire detector according to the second aspect of the invention, in which the stain compensation means is at least from the stain detection detection sensor when the translucent window is in a non-dirt state. A storage unit is provided for storing information relating to the signal level of the output signal to be output and the variably controlled emission energy.

  Therefore, based on the reference value stored in the storage unit, the output signal from the contamination detection detection sensor can be converted into a relative output, and appropriate light emission energy can be set according to the contamination state of the translucent window. Therefore, the contamination stage of the translucent window can be appropriately determined, and in the next contamination compensation process, based on the emission energy corresponding to the previous contamination state of the translucent window stored in the storage unit. Since it is possible to start the process of changing and setting an appropriate light emission energy according to the contamination state of the next light-transmitting window, it is possible to simplify the control process and realize a prompt contamination compensation process.

A fire detector according to a fourth aspect of the present invention is the fire detector according to any one of the first to third aspects, wherein the detection sensor and the detection sensor for contamination detection are configured by a single sensor element. It is characterized by being.
That is, the contamination detection detection sensor used to determine the contamination state of the translucent window at the time of execution of the contamination compensation processing is also used by the same sensor element as the detection sensor used for the fire determination processing. .

  Therefore, the sensor unit can be configured easily and inexpensively, and the pseudo flame light corresponding to the flame is applied as the test light, so that detection from the sensor unit (detection sensor and detection sensor for contamination detection) is performed. By combining the circuit configuration of each signal processing system of the fire determination processing and the stain compensation processing for processing the output, the device configuration of the fire detector can be simplified.

A fire detector according to a fifth aspect of the present invention is the fire detector according to any one of the first to third aspects, wherein the detection sensor and the detection sensor for contamination detection are configured by independent and separate sensor elements. It is characterized by having.
That is, when performing the stain compensation process, the stain detection detection sensor used for determining the stain state of the translucent window is a dedicated sensor element that is independent from the detection sensor used for the fire determination process. It is configured.
Therefore, since it is not necessary to apply test light including an energy component peculiar to a flame, a test light source that emits an arbitrary energy component can be applied, and a circuit configuration that processes the detection output from the detection sensor for contamination detection The degree of freedom in design can be improved.

A fire detector according to a sixth aspect of the invention is characterized in that, in the fire detector according to any one of the first to fifth aspects, the test light source is driven to emit light at a flicker frequency peculiar to a flame.
In other words, the test light emitted from the test light source when performing the stain compensation process includes a flicker frequency component peculiar to flame.
Therefore, the contamination state of the translucent window is determined based on the detection output output from the detection sensor for contamination detection by receiving test light containing flicker frequency components equivalent to or similar to that in the fire determination processing. Therefore, an appropriate stain compensation process can be executed.

A fire detector according to a seventh aspect of the present invention is the fire detector according to any one of the first to fifth aspects, wherein the test light source is driven to emit light at a frequency different from a flicker frequency unique to a flame. It is said.
In other words, the test light emitted from the test light source when executing the stain compensation process does not include a flicker frequency component peculiar to flame. Alternatively, it includes a frequency component other than the flicker frequency component peculiar to the flame.

Therefore, it is possible to determine the contamination state of the translucent window based on the detection output output from the contamination detection sensor by receiving the test light including the frequency component peculiar to the contamination compensation processing. It is possible to improve the degree of design freedom of the circuit configuration that processes the detection output from the detection sensor.
In addition, since the frequency components used for the fire determination process and the pollution compensation process are different, the fire determination process and the pollution compensation process can be executed simultaneously, and the fire determination process is interrupted during the pollution compensation process. Can be prevented and the fire detection function can be maintained well.

The fire detector according to claim 8 is the fire detector according to claim 5 or 7, wherein the emission wavelength band of the test light source is different from the wavelength band detected by the detection sensor during the fire determination process. It is characterized by that.
In other words, the wavelength band of the test light emitted from the test light source does not include a flame-specific wavelength component when executing the stain compensation process. Alternatively, it includes a wavelength component other than the wavelength component specific to the flame.

Therefore, it is possible to determine the contamination state of the translucent window based on the detection output output from the contamination detection sensor by receiving the test light including the wavelength component peculiar to the contamination compensation processing. It is possible to improve the degree of design freedom of the circuit configuration that processes the detection output from the detection sensor.
In addition, since the wavelength components used in the fire determination process and the pollution compensation process are different, the fire determination process and the pollution compensation process can be executed simultaneously, and the fire determination process is interrupted during the pollution compensation process. Can be prevented and the fire detection function can be maintained well.

  According to the present invention, in the fire detector having a fouling compensation function that automatically compensates for the deterioration of the fire detection function due to the fouling of the translucent window in which the detection sensor for fire determination is housed, the translucent window The emission energy of the test light emitted from the test light source is variably set and controlled according to the contamination state of the translucent window with respect to the detection sensor for contamination detection disposed inside. Even if the detection output of the test light by the detection sensor for contamination detection is weak due to the contamination state of the light-sensitive window, it is possible to change the translucency by changing the setting so that the light emission energy of the test light source is increased. It is possible to properly detect the dirty state of the window, and to maintain and guarantee a good fire detection function by executing a stain compensation process that appropriately sets the detection sensitivity according to the dirty state of the translucent window. it can.

First, the overall configuration of the fire detector according to the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a schematic block diagram showing a first embodiment of a fire detector according to the present invention, and FIG. 2 is a function showing a schematic configuration of a signal processing unit applied to the fire detector according to this embodiment. It is a block diagram. In FIG. 2, the configuration related to the stain compensation process that is a feature of the present invention will be described in detail, and the description of the configuration related to the fire determination process will be simplified.

  As shown in FIG. 1, the fire detector according to the present embodiment is roughly divided into a sensor unit (detection sensor, detection for fouling detection) that converts infrared energy (light energy) in a predetermined wavelength band into an electrical signal and outputs it. (Sensor combined) SEN, a translucent window 11 for protecting the detection sensor disposed on the detection surface side of the sensor unit SEN, and a detection signal Sa output from the sensor unit SEN, a fire in the signal processing unit PRO described later The filter unit FLT that passes only the signal component Aa in a predetermined frequency band used for the determination process (or flame determination process) and the pollution compensation process, and the signal component Aa that has passed through the filter part FLT is used for the fire judgment process and the pollution compensation process. A signal amplifier AMP that amplifies the signal to an appropriate signal level and an analog output Ba (analog signal) Ba that is output from the signal amplifier AMP is converted into a digital signal. G-digital conversion unit (hereinafter referred to as “A / D conversion unit”) 50 and a signal processing unit (fire determination) that executes fire determination processing and contamination compensation processing based on the A / D converted received light output level Means, stain compensation means) PRO, an amplification control unit 70 for changing and controlling the amplification factor for amplifying the detection signal Sa output from the sensor unit SEN according to the stain state of the transparent window 11, and the transparent window 11 in a test operation for detecting the fouling state, a test light source LGT that emits light at a predetermined light emission frequency and light emission energy, and a test light source protecting translucent window (hereinafter referred to as a test light source LGT). And a test light source control unit 80 that controls the light emission state of the test light source LGT.

Hereinafter, each configuration will be described in detail.
(A) Sensor unit SEN / Filter unit FLT
The sensor unit SEN includes a pyroelectric light receiving element 10 that detects infrared energy emitted from a heat source such as a flame FR, converts the infrared energy into an electric signal, and outputs the electric signal. The filter unit FLT includes the light receiving element 10. Is provided with a frequency filter (pre-filter) 20 that passes only the signal component Aa in a specific frequency band used for the fire determination process from the detection signal Sa output from.

(B) Translucent window 11
The translucent window 11 is, for example, disposed on the one surface side (detection area side) of the main body cover (housing) in which the sensor unit SEN is accommodated, and is disposed on the light receiving surface side of the light receiving element 10. It is formed by the infrared transparent member. Here, the outer surface side of the translucent window 11 shall be in the state exposed to the external air (airflow) in a tunnel.

(C) Filter part FLT
The filter unit FLT includes a frequency filter (pre-filter) 20 and allows only the signal component Aa included in the flame-specific frequency band used for the fire determination process to pass from the detection signal Sa output from the light receiving element 10. Then, the signal amplification unit (preamplifier 30, main amplifier 40) in the subsequent stage is transmitted to the AMP.

(D) Signal amplifier (preamplifier 30 / main amplifier 40) AMP
The signal amplifying unit AMP includes a preamplifier 30 that amplifies the signal component Aa that has passed through the filter unit FLT in the first stage, and a main amplifier 40 that amplifies the output from the preamplifier 30 to a signal level suitable for fire determination processing. The output detection signal Sa is amplified with a predetermined amplification factor. Here, the signal amplification factor in the signal amplification unit AMP is configured to be arbitrarily changeable. Details will be described later.

(E) A / D converter 50
The A / D conversion unit 50 converts the analog signal output from the main amplifier 40 into a digital signal suitable for fire determination processing and contamination compensation processing. The A / D conversion unit 50 is necessary only when the signal processing unit PRO at the subsequent stage performs digital signal processing, and is omitted when it is configured by a processing circuit that directly handles analog signals. Can do.

(F) Amplification control unit 70
The amplification control unit 70 controls the sensor unit SEN by changing and controlling the signal amplification factor of at least one of the preamplifier 30 and the main amplifier 40 constituting the signal amplification unit AMP based on a control command from the signal processing unit PRO. The signal amplification factor is set so that the detection signal Sa output from the signal signal Sa is amplified to a predetermined signal level suitable for fire determination processing and contamination compensation processing in the subsequent signal processing unit PRO.

(G) Test light source controller 80 / Test light source LGT
The test light source control unit 80 controls a predetermined test light (light emission level or light emission energy) by controlling the blinking state (light emission frequency) and light emission intensity (light emission level or light emission energy) of the test light source LGT based on a control command from the signal processing unit PRO. For example, a simulated flame light that blinks in a specific frequency band and emission intensity) is projected onto the sensor unit SEN.

Here, since the test light transmissive window 12 is disposed in front of the test light source LGT, the test light projected from the test light source LGT passes through the test light transmissive window 12 once. The light is emitted to the outside of the fire detector, and then enters the light receiving element 10 through the translucent window 11 disposed in front of the sensor unit SEN.
In addition, as the test light source LGT, a light source that emits light including a wavelength component peculiar to a flame, for example, an incandescent lamp or the like that is controlled to blink at a frequency corresponding to a flicker frequency peculiar to a flame (several Hz). Can be applied.

(H) Signal processor PRO
The signal processing unit PRO determines at least the fire determination unit 60A that executes the fire determination process and the contamination state (or degree of contamination) of the translucent window 11, and performs a predetermined contamination compensation process corresponding to the contamination state. A contamination determination unit 60B for execution is provided.
In the fire monitoring mode, the fire determination unit 60A detects the presence or absence of a flame based on the light reception output level output from the signal amplification unit AMP via the A / D conversion unit 50, and determines the occurrence of a fire. Execute the judgment process.

  In addition, in the functional test mode of the fire detector, the contamination determination unit 60B sends a control command to the test light source control unit 80 to control blinking of the test light source LGT with a predetermined light emission frequency and light emission energy. Based on the detection signal Sa output from the part SEN, the fouling state of the translucent window 11 arranged in front of the sensor part SEN is detected. Then, based on the fouling state or the like, a control command is sent to the test light source control unit 80, and the light emission energy of the test light projected from the test light source LGT is variably set and controlled, thereby translucent window 11 is adjusted so that test light having an appropriate light emission level corresponding to the fouling state is emitted from the test light source LGT, and a control command is sent to the amplification control unit 70 based on the fouling state, so that the signal amplifying unit By variably setting and controlling the signal amplification factor in the AMP, the detection sensitivity as a fire detector (that is, the detection sensitivity for the flame) is adjusted, and the fouling compensation processing for appropriately executing the fire determination processing is performed. Execute.

  Furthermore, the fire determination unit 60A and the contamination determination unit 60B are the disaster prevention whose illustration is omitted for the result of the fire determination processing and the contamination state of the translucent window 11 (for example, the contamination abnormality signal when the contamination compensation limit is reached). Notify the disaster prevention monitoring panel installed at the center. Note that the transition from the fire monitoring mode to the functional test mode may be executed periodically, or in response to a test command from a fire monitoring panel installed outside the fire detector, for example, a disaster prevention center. Based on this, it may be executed at an arbitrary timing.

Here, a specific configuration of the signal processing unit PRO will be described.
Specifically, as shown in FIG. 2, the signal processing unit PRO is roughly divided into a fire determination unit 60 </ b> A that performs a fire determination process, a contamination determination unit 60 </ b> B that executes a contamination compensation process, and light emission of the test light source LGT. Correlation table 61 that defines the correlation between the level (luminescence energy), the stage of contamination of the light-transmitting window 11 (fouling state), and the threshold range of the relative light-receiving power, and the state where the light-transmitting window is not soiled Stores and holds initial information such as the light emission level of the test light source LGT and the light receiving output level obtained from the detection sensor SEN in the non-fouling state, and information on the light emission level of the test light source LGT that is set and controlled in the function test mode. Based on the test light emitted from the storage unit 62 and the test light source LGT, the contamination determination unit 60b appropriately determines the contamination state (or contamination degree) of the translucent window 11. And a light emission level control unit 63 that appropriately sets and controls the light emission level (or light emission energy) of the test light according to the contamination state of the translucent window 11. ing. Details of the correlation table 61 will be described later.

  When the fire determination unit 60A performs a predetermined fire determination process based on the amplified output (light reception output level) from the A / D conversion unit 50 (or the main amplifier 40) and determines the occurrence of a fire The fire determination information is transmitted to the disaster prevention monitoring panel installed in the disaster prevention center through an interface circuit (not shown). As a specific method for the fire determination process, for example, a method of comparing the integrated level of the amplified output with a predetermined fire determination level can be applied. As other fire determination methods, various methods such as a method for determining whether or not a flicker frequency peculiar to a flame can be obtained and a combination with the above-described level comparison can be applied.

  The contamination determination unit 60B controls the test light source control unit 80 periodically or based on a test command from the outside of the fire detector, such as a disaster prevention monitoring panel installed in the disaster prevention center, and a predetermined emission frequency, and The test light of the predetermined light emission level set by the light emission level control unit 63 is emitted from the test light source LGT, and the detection signal output from the detection sensor SEN is amplified and output (light reception output level) by projecting the test light. Receive as. At this time, a relative value (light reception relative output) of the light reception output level with respect to a predetermined initial value (reference value) is calculated, and the light reception relative output is within a predetermined threshold range set in advance according to the light emission level. It is determined whether or not the light emission level of the test light with respect to the contamination state of the translucent window 11 is appropriate.

  Further, the contamination determination unit 60B determines the contamination stage (contamination state) of the translucent window 11 based on the received light relative output obtained when the light emission level of the test light is appropriate, and according to the contamination stage. Then, by controlling the amplification control unit 70 and switching the setting state of the signal amplification factor (detection sensitivity) in the signal amplification unit AMP, a stain compensation process for appropriately correcting and controlling the light reception output level in the fire determination process is executed.

  The light emission level control unit 63 determines whether or not the light emission level of the test light is the fouling state of the translucent window 11 based on the determination result of whether or not the light reception relative output is within a predetermined threshold range by the fouling determination unit 60B. Is variably set and controlled so as to obtain an appropriate level in determining Thereby, the test light source control unit 80 performs control to switch the light emission drive current value of the test light source LGT to a predetermined value, for example, corresponding to the light emission level set by the light emission level control unit 63.

  Here, in the stain determination unit 60B, it is determined whether or not the received light relative output is within a predetermined threshold range, and the light emission level control unit 63 performs setting control so that the light emission level becomes an appropriate level. As shown in this embodiment, it is possible to satisfactorily apply a method of referring to the correlation table 61 in which a predetermined correlation is defined in advance, a method of calculating using a specific calculation formula, and the like. A method of referring to the correlation table 61 will be described later.

  In the contamination compensation process for determining whether or not the light reception relative output is within a predetermined threshold range and setting and controlling the light emission level of the test light to an appropriate level, the light reception relative output falls within a predetermined contamination compensation limit. If it is reached (that is, if the state of fouling of the translucent window 11 is significant and the control that increases the signal amplification factor in the signal amplifying unit AMP reaches a state where the flame cannot be detected well), the interface The contamination information is transmitted to the disaster prevention monitoring panel of the disaster prevention center through the circuit I / F.

Next, a correlation table applied to the present embodiment will be described with reference to the drawings.
FIG. 3 is a correlation table showing an example of the correlation between the light emission level of the test light source LGT, the light reception relative output, and the contamination stage of the translucent window 11, which is applied to the contamination compensation process of the fire detector according to the present embodiment. It is.

  In the present embodiment, as shown in the correlation table of FIG. 3, the relative light levels FL1 to FL3 of the test light source LGT relative to the predetermined initial state are associated with the relative relative to the predetermined initial state. A threshold range of a typical light receiving output level (light receiving relative output) is set. Specifically, in the non-fouling state of the translucent window 11 or the fouling state in which the fouling is lightest, the light emission level of the test light source LGT that transmits the test light through the translucent window 11, and When the received light output level for the test light is associated as a reference (initial value “1”) and the contamination state of the translucent window 11 is determined, an appropriate received light output level is not affected by the noise level or the like. As obtained, each light emission level (relative light emission energy) and a corresponding light receiving relative output threshold range are set.

For example, the arbitrary light emission energy of the test light source LGT when the translucent window 11 is not contaminated is used as a reference (initial value “1”; light emission level FL1). .25, and the threshold range of the received light relative output at the light emission level FL2 in which the light emission energy of the test light source LGT is twice the initial value is defined as 0.5 to 0.125. The threshold range of the received light relative output at the light emission level FL3 where the light emission energy of LGT is four times the initial value is defined as 0.25 to 0.09 and 0.09 or less.
Then, based on the correlation between the light emission level (relative light emission energy) of the test light source LGT and the light reception relative output, the light emission level of the test light source LGT The light emission level of the test light source LGT is variably set stepwise so that the received light relative output becomes an appropriate level.

  Further, based on the light reception relative output at the set (determined) light emission level, the contamination state of the translucent window 11 through which the test light is transmitted (that is, the degree of contamination or reduction converted based on the light emission level and the light reception relative output). A contamination stage in which the light rate is divided in stages) is determined. Specifically, when the test light source LGT is at the light emission level FL1 (relative light emission energy “1”) and the received light relative output is within the threshold range of 1 to 0.25, the contamination stage SL1 (reduction level). When the light emission relative output is within the threshold range of 0.5 to 0.125 in the state of the light emission level FL2 (relative light emission energy “2”). Is determined to be a contamination stage SL2 (corresponding to a light attenuation rate of 50 to 75%), and the light receiving relative output is 0.25 to 0.09 in the state of the light emission level FL3 (relative light emission energy “4”). If it is within the threshold range, it is determined that the contamination stage SL3 (corresponding to a dimming rate of 75 to 85%), and in the state of the light emission level FL3 (relative light emission energy “4”), the light reception relative output is 0. In the case of 09 or less, the contamination stage It determines that the L4 (corresponding to 85% or more light rate decrease).

The effectiveness of the correspondence relationship between the light emission level of the test light source LGT, the light receiving relative output, and the fouling state (fouling stage) of the translucent window 11 will be described in detail in comparison with the prior art.
FIG. 4 is a table for the sake of convenience in order to compare the correlation between the light emission level applied to the stain compensation processing in the prior art, the light receiving relative output, and the stain state of the translucent window with the correlation table shown in FIG. It is shown in the form. FIG. 5 is a correlation diagram showing the relationship between the fouling state (fouling stage and light attenuation rate) and the received light relative output when the correlation table shown in FIG. 4 is applied, and FIG. 6 is shown in FIG. It is a correlation diagram which shows the relationship between the stain | pollution | contamination state (fouling step and light attenuation rate) at the time of applying the correlation table which received and a light reception relative output.

  As shown in FIG. 4, in the prior art, as in this embodiment, when the threshold range of the four-step received light relative output is set, means for variably setting and controlling the light emission level of the test light source 11 is provided. Since the light emission energy at each light emission level is constant and variable control is impossible, the contamination stage of the translucent window 11 has any threshold of the light reception relative output based on the light reception output level. It is determined only by the correspondence relationship whether it falls within the value range. That is, the received light relative output of the test light emitted from the test light source at a constant light emission level (relative light emission energy) is included in any of the preset threshold ranges (upper threshold value to lower threshold value). Depending on whether or not, the fouling state of the translucent window (fouling stages SL1 to SL4 and the light reduction rate) is determined.

  Here, the dimming rate converted based on the light receiving relative output of the test light depends on the contamination state of the translucent window and the test light translucent window, as in the case of the present embodiment. In this example, it is assumed that the degree of progress of contamination of the translucent window and that of the test light-transmitting window are the same. When the difference is known in advance, for example, a process equivalent to the above can be realized by setting a predetermined coefficient corresponding to the difference and converting the light attenuation rate.

  Therefore, for example, the light receiving relative output of the test light is a threshold range of 1 to 0.25 [= (= Light-transmitting window light reduction rate 50%) × (test light-transmitting window light attenuation rate 50%)]], the light attenuation rate is related to the fouling stage SL1 defined by 0 to 50%. It is done. Further, the light receiving relative output of the test light is within a threshold range of 0.25 to 0.0625 [= (light extinction rate of translucent window 25%) × (light extinction rate of test light transmissible window 25%)] , The relative light output of the test light is within the threshold range 0.0625 to 0.0225 [= (translucent window). ) ((Test light transmissible window dimming rate 15%))], the dimming rate is associated with the fouling stage SL3 defined by 75-85%. Further, when the light receiving relative output of the test light is within the threshold range 0.0225 or less, it is associated with the fouling stage SL4 defined by the light attenuation rate of 85% or more. Here, when the contamination stage SL4 (light reception relative output is 0.0225 or less), that is, when the light attenuation rate is 85% or more, it is determined that the contamination compensation limit has been reached.

  Then, considering the threshold accuracy range of the light receiving relative output and the accuracy of discrimination between the contamination stage and the light attenuation rate, as shown in FIG. 5, the light receiving relative output is 1/1 / between the contamination stages SL1 and SL2. Since it has a relatively large level difference of 10 orders and its absolute value also has an effective size, the contamination stage and the light attenuation rate can be satisfactorily determined based on the received light relative output. Between the contamination stages SL2 and SL3, or between the contamination stages SL3 and SL4, the received light relative output becomes a slight level difference of 1/100 order corresponding to the noise level, and particularly near the lower limit threshold value of the contamination stage SL4. However, since the absolute value is also very small, it is difficult to accurately determine the fouling stage and the light attenuation rate based on the light receiving relative output.

  On the other hand, in the present embodiment, as shown in FIG. 3, the light emission level of the test light source LGT and the light reception output level for the test light of the light emission level when the translucent window 11 is in a non-fouling state are used as a reference. The light emission level (relative light emission energy) of the test light source LGT and the threshold range of the light receiving relative output corresponding to the light emission level of the test light source LGT are set and controlled in a stepwise manner according to the contamination state of the translucent window 11. To do.

  That is, relative to the test light of the light emission level FL1 with reference to the light emission energy of the test light source LGT and the light reception output level when the light transmission window and the test light translucent window are in a non-fouling state (“1”). Output is within a threshold range of 1 to 0.25 [= (relative light emission energy “1”) × (light transmission window light reduction rate 50%) × (test light transmission window light reduction rate 50%)] In this case, the dimming rate is associated with the fouling stage SL1 defined by 0 to 50%. In addition, the light receiving relative output of the test light of the light emission level FL2 is a threshold range 0.5 [= (relative light emission energy “2”) × (light extinction rate of translucent window 50%) × (test light translucency]. (Light attenuation rate of window 50%)] to 0.125 [= (relative light emission energy “2”) × (light attenuation rate of translucent window 25%) × (light attenuation rate of test light transmissible window 25%) )]], The light emission relative output of the test light of the light emission level FL3 is related to the fouling stage SL2 defined by the light attenuation rate of 50 to 75%, and the threshold range 0.25 [= (relative light emission). Energy “4”) × (light-transmitting window light attenuation rate 25%) × (test light-transmitting window light attenuation rate 25%)] to 0.09 [= (relative emission energy “4”) × ( Light-transmitting window light reduction rate of 15%) × (test light-transmitting window light attenuation rate of 15%)]], the contamination level SL3 is set at 75 to 85%. Associated. Furthermore, when the light receiving relative output of the test light of the light emission level FL3 is in the threshold range 0.09 or less, it is associated with the contamination stage SL4 in which the light attenuation rate is defined as 85% or more. Here, when the contamination stage SL4 (light reception relative output is 0.09 or less), that is, when the light attenuation rate is 85% or more, it is determined that the contamination compensation limit has been reached.

  Here, as with the above-described prior art, when examining the determination accuracy of the light emission level of the test light and the threshold range of the received light relative output, the contamination stage, and the light attenuation rate, as shown in FIG. A fouling stage SL2 (L1a in the figure) based on the received light relative output for the test light of the light emission level FL1 and a fouling stage SL2 based on the received light relative output for the test light of the light emission level FL2 having twice the light emission energy of the light emission level FL1 L2a), and a light receiving relative output for the test light of light emission level FL3 having a light emission energy four times that of the contamination level SL2 (L2a in the figure) and the light emission level FL1 based on the light reception relative output for the light of the light emission level FL2. The contamination stage SL3 (L3a in the figure) or the contamination stage S based on the received light relative output to the test light of the light emission level FL3 3 (L3a in the figure) and a relatively large level of the light receiving relative output of about 1/10 order in any of the relations of the contamination stage SL4 (L3b in the figure) based on the light receiving relative output with respect to the test light of the light emission level FL3. In addition to having a difference, the absolute value is set large in the vicinity of the lower threshold value of the fouling stage SL4, so that the fouling state of the translucent window 11 and the test light translucent window 12 proceeds. In addition, the contamination stage and the light attenuation rate can be determined with high accuracy, and an appropriate contamination compensation process can be performed to execute a good fire determination process.

  In the present embodiment, in the correlation table shown in FIG. 3, the contamination state of the translucent window 11 and the threshold range of the light receiving relative output are defined in four stages, and the contamination state of each stage is defined. The case has been described in which the light emission level of the test light source is variably set and controlled to be twice or four times the initial value so that it can be accurately determined, but the present invention is limited to this form. Instead, the light emission level may be set and controlled steplessly and continuously.

Next, operation processing in the fire detector according to the present embodiment described above will be specifically described with reference to the drawings.
FIG. 7 is a functional block diagram showing a functional test mode (initial registration processing state and contamination compensation processing state) of the fire detector according to the present embodiment, and FIG. 8 is a fire monitoring of the fire detector according to the present embodiment. It is a functional block diagram which shows a mode (fire determination process). FIG. 9 is a flowchart showing a procedure for shifting from the fire monitoring mode to the functional test mode applied to the fire detector according to the present embodiment. Here, description will be made with reference to the configuration of the signal processing unit shown in FIG. 2 and the correlation table shown in FIG. 3 as appropriate.
The operation process in the fire detector according to the present embodiment includes an initial value registration process, a fire determination process, and a stain compensation process.

<Initial value registration process>
First, in the initial value registration process, as shown in FIG. 2 and FIG. 7, the light-transmitting window 11 and the test light-transmitting window 12 are not fouled (no fouling state: at the time of manufacture, at the time of factory shipment, etc. ), Or a state in which the contamination is lightest, the light emission level (relative light emission energy “1”) of the test light source LGT set by the light emission level control unit 63 and the light emission by the test light source control unit 80. The detection signal (light reception output level) obtained from the detection sensor SEN is stored in the storage unit 62 as an initial value (or reference value) for the test light CK projected by controlling the blinking of the test light source LGT at a level. Remember.
Further, the contamination state of the translucent window 11 in this initial state is determined as the contamination stage SL1 because the light attenuation rate calculated based on the light emission level FL1 of the test light source LGT and the light reception relative output is approximately 0%. The

<Fire judgment processing>
In the fire determination process, as shown in FIG. 8, when the flame FR is observed by the detection sensor SEN, a detection signal Sa corresponding to the radiant energy of the flame FR is output, and a fire is caused by the filter unit FLT and the signal amplification unit AMP. Only the signal component Aa in the frequency band used for the determination process is extracted, and is amplified with the signal amplification factor set by the initial value registration process (at the time of no stain) or the stain compensation process described later. The amplified output Ba is converted into a digital signal by the A / D conversion unit 50 and input to the signal processing unit PRO (fire determination unit 60A) as a light reception output, and a predetermined fire determination process is executed.

  And when the dirt which adheres to translucent window 11 arranged ahead of a detection sensor increases with progress of time, according to the pollution stage (or pollution degree) judged by pollution compensation processing mentioned below Thus, the signal amplification factor of the signal amplification unit AMP is changed, and the detection sensitivity inside the fire detector is increased to, for example, 2 times, 4 times, or the like with respect to the initial value. In this way, by compensating the light reception output level according to the contamination state, the detection sensitivity of the fire detector is ensured within a predetermined level range that guarantees an appropriate fire detection function, and good fire determination processing is performed. continue. Note that when the contamination decreases with time, processing for lowering the detection sensitivity to an appropriate level is performed so that the detection sensitivity to other non-fire sources does not become too sensitive.

Here, the transition from the fire monitoring mode in which the fire determination process is executed to the functional test mode in which the stain compensation process is executed is as shown in FIG. 9 in a state in which the fire determination process is always executed (S101). For example, when a test command is received from the outside of a fire detector, such as a disaster prevention monitoring panel of a disaster prevention center, or a test command is received by a timer output at a predetermined cycle from a built-in timer provided inside the fire detector. In the case (S102), the signal processing unit (fire determination unit) PRO is executed by temporarily stopping the fire determination process in the fire determination unit 60A and starting the contamination compensation process by the contamination determination unit 60B ( S103). Here, the test command output from the disaster prevention monitoring board of the disaster prevention center may be, for example, a timer output that is built in the disaster prevention monitoring board or is output at predetermined intervals from a timer that is attached to the disaster prevention monitoring board. It may be output at an arbitrary timing based on an artificial function test execution operation by a person. In addition, as a period which performs a stain | pollution | contamination compensation process, it sets to a 24-hour period etc., for example.
When the stain compensation process is completed, the function test mode (S103) is shifted to the fire monitoring mode (S101).

<Fouling compensation processing>
Next, a specific processing procedure of the stain compensation process will be described.
FIG. 10 is a flowchart showing the procedure of the fouling compensation process applied to the fire detector according to the present embodiment.
(Steps S201 and S202)
As shown in FIG. 10, first, the signal processing unit PRO switches from the fire monitoring mode to the functional test mode upon receiving a test command, and starts a test process including a stain compensation process. Thereby, various settings of the contamination determination unit 60B related to the previous contamination compensation process and the signal amplification factor of the signal amplification unit AMP are reset to the initial state.

(Steps S203 and S204)
Next, the contamination determination unit 60B reads information (for example, FL2) related to the emission level (relative emission energy) of the test light source LGT used in the previous contamination compensation process, which is stored in the storage unit 62, and controls the emission level. And the upper limit value data (in the case of FL2, “0.5”) defining the threshold range of the received light relative output corresponding to the light emission level, and the correlation table (FIG. 3). Lower limit data ("0.125" for FL2) is read.

(Steps S205 and S206)
Next, the light emission level control unit 63 drives and controls the test light source control unit 80 based on the light emission level (relative light emission energy “2”) read from the storage unit 62, so that the test light source LGT emits predetermined light. It is lit and driven for a predetermined time with a flashing cycle that is strong and approximates the flicker frequency of the flame.

Thereby, the test light (pseudo flame light) CK projected from the test light source LGT is received by the light receiving element 10 via the test light translucent window 12 and the translucent window 11 as shown in FIG. Received light.
The light receiving element 10 outputs a detection signal corresponding to the light emission level of the test light (relative light emission energy “2”) and the contamination state of the translucent window 11, and has a predetermined frequency band in the filter unit FLT and the signal amplification unit AMP. It is amplified to a light receiving output having a signal component and a signal level, and is taken into the signal processing unit PRO for a predetermined period at predetermined time intervals.

  That is, the test light CK incident on the light receiving element 10 has the original test light (the light intensity in a state where the light transmitting window 11 is not fouled) according to the state of contamination of the light transmitting window 11 in front of the light receiving element 10. ), The received light output level taken into the signal processing unit PRO has a magnitude reflecting the contamination state of the translucent window 11 in front of the light receiving element 10. Then, when the light reception output level is taken into the signal processing unit PRO for a predetermined period, the test light source control unit 80 controls the test light source LGT to be turned off.

(Step S207)
Next, the ratio of the received light output level captured this time to the initial value of the received light output level stored in the storage unit 62 by the initial value registration process described above, that is, the received light relative output is calculated.
(Steps S208 and S209)
Next, the light reception relative output calculated this time is the upper threshold value (“0.5” in the case of FL2) at the previous light emission level read with reference to the correlation table (FIG. 3) in step S204 described above. It is compared and it is determined whether it is larger than the upper limit threshold value.

(Steps S210 and S211)
In the above-described step S209, when the light reception relative output calculated this time is smaller than the upper threshold value at the previous light emission level, the lower threshold value at the previous light emission level (in the case of FL2, “0. 125 ") and whether it is smaller than the lower threshold or not is determined.

(Step S212)
When the light reception relative output calculated this time is larger than the lower limit threshold value in the previous light emission level (FL2) in step S211, the light reception relative output threshold value corresponding to the light emission level equivalent to the previous light emission level is obtained. It is determined that it is within the range (“0.5 to 0.125” in the case of FL2), and the dimming rate of the test light CK is calculated based on the light emission level and the received light relative output of the test light source LGT this time. At the same time, by referring to the correlation table (FIG. 3), the contamination stage of the translucent window 11 is determined (in this case, SL2), and a predetermined contamination compensation process corresponding to the contamination stage SL2 is executed. Here, in the stain compensation process, as described above, the radiation energy from the flame FR can be detected well through the translucent window 11 in the stain stage, and the fire determination process can be appropriately executed. The signal amplification factor of the signal amplifier AMP is set and controlled so that the light reception output level is obtained.

(Step S213)
Next, after executing the stain compensation process, the information on the light emission level (FL2) of the test light source LGT determined this time is stored and updated in the storage unit 62, and as shown in FIG. Return to monitoring mode.
(Step S214)
If the light reception relative output calculated this time is larger than the upper threshold (“0.5”) in the previous light emission level (FL2) in step S209 described above, the light emission level of the test light source LGT is set. It is determined whether or not it can be set downward. That is, whether or not the lower setting is possible is determined based on whether or not there is a light emission level lower than the previous light emission level (FL2).

(Steps S215 and S216)
If it is determined in step S214 described above that the light emission level can be set lower, the light emission level (FL2) is set one step lower, and the light emission level (FL1; relative light emission) obtained by halving the light emission energy of the test light source LGT. The energy “1”) is stored and updated in the storage unit 62, and the processes in and after step S202 are repeated again.

(Steps S217 and S218)
On the other hand, if the previous light emission level is at the lowest level (that is, FL1) and it is determined in step S214 that lower setting of the light emission level is impossible, the previous light emission level is in the initial state (FL1). That is, it is determined that the translucent window 11 is in an unstained state. In this case, since it is not necessary to execute the stain compensation process, the stain compensation control is canceled, and the information regarding the light emission level (FL1) of the test light source LGT determined this time is stored and updated in the storage unit 62, as shown in FIG. As described above, the function test mode is terminated and the fire monitoring mode is restored.

(Step S219)
In step S211, when the light reception relative output calculated this time is smaller than the lower threshold (“0.125”) in the previous light emission level (FL2), the light emission level of the test light source LGT is set. It is determined whether or not the upper setting is possible. That is, whether or not the upper setting is possible is determined based on whether or not a light emission level higher than the previous light emission level (FL2) exists.

(Steps S220 and S221)
If it is determined in step S211 described above that the light emission level can be set upward, the light emission level (FL2) is set one step higher, and the light emission level (FL3; relative light emission) obtained by doubling the light emission energy of the test light source LGT. The energy “4”) is stored and updated in the storage unit 62, and the processes in and after step S202 are repeated.

(Steps S222, S223, S224)
On the other hand, if the previous light emission level is the highest level (that is, FL3) and it is determined in step S219 described above that the light emission level cannot be set upward, the light-transmitting window 11 is in a dirty state. It is determined that the compensation limit has been reached. In this case, outside the fire detector, for example, to the disaster prevention monitoring panel of the disaster prevention center, a contamination limit signal is output to notify the manager etc. of the abnormality, and the translucent window 11 is cleaned early. Etc., and prompts for appropriate measures, and waits for recovery due to improvement of the contamination state of the translucent window 11. Further, the information regarding the light emission level (FL3) of the test light source LGT determined this time is stored and updated in the storage unit 62.

  By repeating the above-described series of processing steps, the light emission level of the test light source LGT is set either upward or downward as needed according to the contamination state of the translucent window 11, and the received light relative output has a relatively large level difference. As described above, the absolute value of the light receiving output level at the time of the function test is controlled to have an appropriate order even in a state in which the contamination has progressed. Therefore, since the contamination stage or the light reduction rate of the translucent window 11 can be determined with high accuracy, it is possible to realize an appropriate detection sensitivity setting by the contamination compensation process, and to prevent false or missing information in the fire determination process. Occurrence can be greatly suppressed.

  Further, according to the fire detector and the fire detector fouling compensation method according to the present embodiment, as the test light projected from the test light source LGT, a pseudo flame light having a flame-specific wavelength component and flicker frequency is applied. Therefore, the light reception output processing circuit (detection sensor SEN, filter unit FLT, signal amplification unit AMP, A / D conversion unit 50) used for the fire determination process and the fouling compensation process can be shared by a single configuration. Thus, it is possible to execute good fire determination processing and contamination compensation processing while simplifying the circuit configuration.

<Second Embodiment>
Next, a second embodiment of the fire detector according to the present invention will be described with reference to the drawings.
FIG. 11: is a schematic block diagram which shows 2nd Embodiment of the fire detector which concerns on this invention. Here, about the structure equivalent to embodiment mentioned above, the same code | symbol is attached | subjected and the description is simplified.

  In the first embodiment described above, a light reception output processing circuit (detection sensor) applied to the fire determination process and the fouling compensation process by applying the pseudo flame light as the test light CK projected from the test light source LGT. Although the configuration in which the SEN, the filter unit FLT, the signal amplification unit AMP, and the A / D conversion unit 50) are combined has been described, in the present embodiment, the filter unit FLT and the signal amplification unit AMP are also combined using only the sensor unit SEN. In addition, the light reception output processing circuit including the A / D conversion unit 50 is uniquely provided for each of the fire determination processing and the fouling compensation processing, and has a dedicated configuration. Further, the test light CK projected from the test light source LGT is also set to have an arbitrary emission frequency other than the flicker frequency peculiar to the flame and detectable by the sensor unit SEN.

  As shown in FIG. 11, the fire detector according to the present embodiment includes a sensor unit (detection sensor, fouling) including a single light receiving element 10 that outputs a detection signal Sa by observing the flame FR or the test light CK. Detection sensor for detection) SEN, a light reception output processing circuit CIRA for fire monitoring that generates a light reception output (amplification output Ba) suitable for fire determination processing from the detection signal Sa and sends it to the signal processing unit PRO, and detection A light reception output (amplification output Bb) suitable for contamination compensation processing is generated from the signal Sa, and is transmitted to the signal processing unit PRO. The light reception output processing circuit CIRB for contamination compensation, and the light reception outputs from the light reception output processing circuits CIRA and CIRB Based on (amplified output Ba, Bb), based on a control command from the signal processing unit PRO that performs the above-described fire determination processing and stain compensation processing, and the signal processing unit PRO, The amplification control unit 70 that variably sets and controls the signal amplification factor (detection sensitivity) in the signal amplification unit AMPA, and the test light source LGT at a predetermined light emission level (relative light emission energy) according to the contamination state of the translucent window 11 And a test light source control unit 80 that performs light emission driving (flashing control).

  The fire monitoring light receiving output processing circuit CIRA amplifies the signal component Aa with a filter unit FLTA including a frequency filter 20A that allows only a signal component Aa in a predetermined frequency band to pass from the detection signal Sa, and a predetermined amplification factor. It has a signal amplifier AMPA including a preamplifier 30A and a main amplifier 40A, and an A / D converter 50A that converts the amplified output Ba into a digital signal.

  The light reception output processing circuit CIRB for stain compensation includes a filter unit FLTB including a frequency filter 20B that passes only a signal component Ab of a predetermined frequency band applied to the stain compensation processing from the detection signal Sa, and the signal component Ab. A signal amplifier AMPB including a preamplifier 30B and a main amplifier 40B that amplifies at a predetermined amplification factor, and an A / D converter 50B that converts the amplified output Bb into a digital signal are provided.

Similarly to the above-described embodiment (FIG. 2), the signal processing unit PRO includes a fire determination unit 60A that executes a fire determination process and a stain determination unit 60B that executes a stain compensation process.
The test light source LGT is driven to emit light at a predetermined light emission frequency and light emission energy under the control of the test light source control unit 80, but the test light CK to be projected is set so as not to include a flicker frequency peculiar to flame. Yes.

  In the fire detector having such a configuration, in the fire monitoring mode, when the flame FR is observed by the sensor unit SEN, only the signal component Aa having the frequency used for the fire determination process by the filter unit FLTA passes. Then, the amplified output (light reception output) Ba signal amplified by the signal amplification unit AMPA is input to the fire determination unit 60A. At this time, only the frequency component peculiar to the flame passes through the filter unit FLTA, and the frequency component peculiar to the test light CK projected from the test light source LGT is blocked.

  On the other hand, in the functional test mode, when the test light CK from the test light source LGT is observed by the sensor unit SEN, only the signal component Ab having a frequency used for the contamination compensation process is passed by the filter unit FLTB, and the signal amplification unit An amplification output (light reception output) Bb that has been amplified by the AMPB is input to the contamination determination unit 60B. At this time, only the frequency component peculiar to the test light CK projected from the test light source LGT passes through the filter unit FLTB, and the frequency component peculiar to the flame is blocked.

  Therefore, according to the fire detector according to the present embodiment, the test light CK projected from the test light source LGT does not include the flicker frequency peculiar to the flame, but the specific light emission captured as the light reception output by the contamination determination unit 60B. Since it is set so as to have a frequency, the sensor unit SEN is shared by a single configuration, and the light receiving unit includes a filter unit, a signal amplification unit, and an A / D conversion unit that are applied to the fire determination process and the contamination compensation process. The output processing circuit can be configured separately and independently.

As a result, the light reception output processing circuit can be configured to have desired circuit characteristics suitable for the fire determination process or the fouling compensation process, so that the design freedom of the fire detector can be greatly improved. In particular, since the fouling state of the translucent window 11 can be detected well without using a pseudo flame light including a flicker frequency peculiar to a flame, for example, a low power consumption light emitting diode capable of controlling blinking at high speed. (LED) or the like can be applied to the test light source, and in this case, the time required for the function test can be shortened.
In addition, since the frequency components (frequency of light incident on the sensor unit) used for the fire judgment process and the pollution compensation process are different, the fire judgment process and the pollution compensation process can be executed simultaneously, and the pollution compensation The fire detection process can be prevented from being interrupted during the process, and the fire detection function can be maintained well.

<Third Embodiment>
Next, a third embodiment of the fire detector according to the present invention will be described with reference to the drawings.
FIG. 12 is a schematic configuration diagram showing a third embodiment of the fire detector according to the present invention. Here, about the structure equivalent to embodiment mentioned above, the same code | symbol is attached | subjected and the description is simplified.

  In the second embodiment described above, only the sensor unit SEN is used, and the light receiving output processing circuits CIRA and CIRB including the filter units FLTA and FLTB, the signal amplification units AMPA and AMPB, and the A / D conversion units 50A and 50B are provided. However, in the present embodiment, the sensor unit SEN is also used for the fire determination process and the pollution compensation process. In addition to having a dedicated and dedicated configuration, the wavelength band detected by each sensor unit is different. The configuration other than the sensor unit SEN will be described as being the same as in the second embodiment.

  As shown in FIG. 12, the fire detector according to the present embodiment includes a sensor unit SENA, a filter unit FLTA, a signal amplification unit AMPA, A, which are applied to a fire determination process, inside a single translucent window 11. A light receiving output processing circuit CIRA for fire monitoring composed of an A / D converter 50A, a sensor unit SENB, a filter unit FLTB, a signal amplifying unit AMPB, and an A / D converter 50B applied for contamination compensation processing. The light reception output processing circuit CIRB has a configuration provided separately and independently.

  Here, the detection signal Sa output from the sensor unit SENA provided in the light reception output processing circuit CIRA for fire monitoring is an optical wavelength filter (not shown; sensor shown in FIG. 14A) mounted on the sensor unit Sena. Only the signal component Aa in the predetermined wavelength band and the predetermined frequency band passes through the wavelength pass characteristic of the section SEN) and the frequency pass characteristic of the frequency filter 20A.

  On the other hand, the detection signal Sb output from the sensor unit SENB provided in the light receiving output processing circuit CIRB for stain compensation is an optical wavelength filter (not shown; sensor unit shown in FIG. 14A) mounted on the sensor unit SENB. Only the signal component Ab in the predetermined wavelength band and the predetermined frequency band passes due to the wavelength pass characteristic of the SEN configuration) and the frequency pass characteristic of the frequency filter 20B.

In this embodiment, the optical wavelength filter mounted on the sensor unit SENA is an optical type filter that passes light in the wavelength band (wavelength band near 4.4 to 4.5 μm) due to the resonance radiation of CO ₂ . A band-pass filter is used, and a band-pass filter that passes light in a wavelength band different from the wavelength band due to the resonance emission of CO ₂ is used as the optical wavelength filter mounted in the sensor unit SENB.
Further, the test light source LGT is driven to emit light at a predetermined light emission frequency and light emission energy under the control of the test light source controller 80, but the test light CK to be projected includes at least components other than the wavelength band specific to the flame. And an arbitrary wavelength band that can be detected by the sensor unit SENB.

In the fire detector having such a configuration, in the fire monitoring mode, when the flame FR is observed by the sensor unit SENA, the amplified output including the wavelength component and the frequency component used for the fire determination processing by the light reception output processing circuit CIRA. (Light reception output) Ba is input to the fire determination unit 60A, and in the functional test mode, when the test light CK from the test light source LGT is observed by the sensor unit SENB, the light reception output processing circuit CIRB is used for contamination compensation processing. An amplification output (light reception output) Bb including a wavelength component and a frequency component is input to the contamination determination unit 60B.
That is, in the functional test mode, only the components other than the wavelength band due to the resonance radiation of CO ₂ specific to the flame pass through the optical wavelength filter mounted on the sensor unit SENB among the test light CK emitted from the test light source LGT. Then, it is taken in as a light reception output by the contamination determination processing unit 60B.

  Therefore, according to the fire detector according to the present embodiment, dedicated light receiving output processing circuits CIRA and CIRB including the sensor units SENA and SENB are individually provided corresponding to the fire determination process and the contamination compensation process, and the test is performed. The test light CK projected from the light source LGT and detected by the sensor unit SENB substantially does not include a flame-specific wavelength band (in other words, the received light output taken in by the fouling determination unit 60B has a flame-specific wavelength). Since it is set to be other than the band and includes the wavelength band peculiar to the pollution compensation process, the light reception output processing circuit is configured to have desired circuit characteristics suitable for the fire determination process or the pollution compensation process. Therefore, the design freedom of the fire detector can be greatly improved, and the stain compensation process can be performed appropriately.

Further, since the contamination compensation sensor unit SENB has a configuration independent of the fire monitoring sensor unit SENA, the contamination compensation sensor unit SENB is connected to the test light source LGT via the translucent window 11. It can be placed at any position that sees through.
In addition, since the wavelength band (wavelength incident on the sensor unit) used for the fire determination process and the stain compensation process is different, the fire determination process and the stain compensation process can be executed simultaneously, and the stain compensation process is in progress. The fire detection process can be prevented from being interrupted and the fire detection function can be maintained well.

  In the present embodiment, the case where the wavelength band of the test light source is set so as not to include a wavelength component peculiar to the flame has been described. However, the present invention is not limited to this, and In addition to setting the appropriate wavelength band, it may be set so as not to include the flicker frequency peculiar to the flame as shown in the second embodiment.

<Fourth Embodiment>
Next, a fourth embodiment of the fire detector according to the present invention will be described with reference to the drawings.
FIG. 13: is a schematic block diagram which shows 4th Embodiment of the fire detector which concerns on this invention. FIG. 14 is a diagram illustrating a configuration example of a sensor unit applied to the fire detector according to the present embodiment and an arrangement example of light receiving elements. Here, about the structure equivalent to embodiment mentioned above, the same code | symbol is attached | subjected and the description is simplified.

  In each of the embodiments described above, the configuration has been described in which each sensor unit includes a single light receiving element, and a light reception output based on a single detection signal output from the light receiving element is output to the signal processing unit. In the embodiment, the sensor unit includes a plurality of light receiving elements, outputs detection signals individually for each light receiving element, and arbitrarily adds and synthesizes (integrates) the detection signals with each other to perform signal processing corresponding to amplification processing. A signal amplifying unit is provided.

  As shown in FIG. 13, the fire detector according to the present embodiment includes a sensor unit SEN including a plurality of light receiving elements 10a to 10h inside a single light-transmissive window, and each light receiving element 10a to 10h. And a filter unit FLT having a plurality of frequency filters 20a to 20h that pass only the signal components Aa to Ah in a predetermined frequency band from the detection signals Sa to Sh, and a predetermined combination of the signal components Aa to Ah. The signal amplifying unit AMP that performs addition and synthesis at a predetermined amplification factor, and a fire determination unit 60A that performs a fire determination process based on the amplified output output from the signal amplifying unit AMP via the A / D conversion unit 50 And a signal processing unit PRO provided with a contamination determination unit 60B for performing contamination compensation processing, and a switch control unit (increase control) for setting and controlling the addition / combination state of the signal components Aa to Ah in the signal amplification unit AMP. A control unit) 71, and the test light source control unit 80 for lighting control test light source LGT at a predetermined emission energy is configured to have a.

Hereinafter, only the characteristic configuration in the present embodiment will be specifically described.
(Li) Sensor part SEN / Filter part FLT
The sensor unit SEN has substantially the same detection area and is configured to include a plurality of light receiving elements 10a to 10h that detect infrared energy from a heat source such as a flame FR substantially simultaneously, and the filter unit FLT From the detection signals Sa to Sh output from each of the light receiving elements 10a to 10h, there are frequency filters (pre-filters) 20a to 20h that pass only signal components Aa to Ah in a specific frequency band used for the fire determination process. Configured.

  Here, the sensor unit SEN specifically includes, for example, as shown in FIG. 14A, a substrate 13 on which a plurality of light receiving elements 10a to 10h are formed, and a substrate mounting for supporting the substrate 13. Portion 14, terminal 16 extending from the back side of substrate mounting portion 14, and terminal 16 penetrating from one surface side (upper surface side of drawing) to the other surface side (lower surface side of drawing). And a cover member 18 that protects the light receiving elements 10a to 10h and the substrate 13 by providing a base 15 to which the portion 14 is fixed, and a protective translucent window 17 that is an optical wavelength filter in front of the light receiving elements 10a to 10h. Thus, the sensor module has a packaged configuration.

As an arrangement example of the light receiving elements 10a to 10h applied to such a sensor unit SEN, for example, as shown in FIG. 14B, the same element dimensions (size), that is, on a single substrate 13, that is, A plurality of light receiving elements 10a to 10h having the same detection sensitivity (eight in the present embodiment) arranged in a matrix can be applied. Note that the arrangement example of the light receiving elements 10a to 10h is not limited to the matrix shape, but may be an array shape having an arbitrary arrangement such as a linear shape or a staggered shape. Here, the array shape means a group of light receiving elements formed by the same manufacturing process on the same substrate.
Each of the light receiving elements 10a to 10h is set to monitor substantially the same detection area substantially simultaneously, and is configured to output the detection signals Sa to Sh individually to the frequency filters 20a to 20h. .

  As described above, the light receiving elements 10a to 10h are formed in an array and packaged as a sensor module, whereby the configuration of the sensor unit SEN can be reduced in size and the detection sensitivity characteristics of the light receiving elements 10a to 10h. And the output detection signals Sa to Sh can be made substantially equivalent (Sa≈Sb≈Sc≈Sd≈Se≈Sf≈Sg≈Sh), and the later-described addition amplification process is performed satisfactorily. be able to.

13 and 14 show the sensor unit SEN including the eight light receiving elements 10a to 10h for convenience of explanation. However, for the number of light receiving elements, the arrangement method, the element dimensions, etc. It is not limited.
As another configuration example of the sensor unit SEN, a plurality of the same type of sensor modules 10A packaged with only a single light receiving element is prepared, and these are arranged in a predetermined arrangement in proximity to each other. Configurations can also be applied.
In this way, a relatively inexpensive general-purpose sensor module can be applied to the sensor unit by arranging a plurality of sensor modules 10A of the same type that are individually packaged in close proximity to each other. The device can be constructed inexpensively and simply.

(Nu) Signal amplifier AMP
The signal amplifying unit AMP includes preamplifiers 30a to 30h for amplifying the signal components Aa to Ah of the detection signals Sa to Sh individually input through the frequency filters 20a to 20h at a predetermined amplification factor, respectively, and a preamplifier 30c. The switches SW1 and SW2 that set the output lines La to Lh of ˜30h to the contact NA or the cutoff state and the output lines La to Lh of the preamplifiers 30a to 30h are coupled and connected in a predetermined state ( And a main amplifier 40 that amplifies the added output obtained by the addition to a signal level suitable for the fire determination process.

  Specifically, the output line LAa in which the output lines La and Lb from the preamplifiers 30a and 30b are connected at the contact na is always connected to the main amplifier 40 through the contact NA, and the outputs from the preamplifiers 30c and 30d. The output line LAb in which the lines Lc and Ld are connected at the contact nb is connected to the contact NA via the switch SW1, and the output line LAc from the preamplifiers 30e to 30h is connected to the contact nc in the switch nc. It is connected to the contact NA via SW2.

  Accordingly, the amplified outputs from the preamplifiers 30a and 30b are added and synthesized at the contact na, the amplified outputs of the preamplifiers 30c and 30d are added and synthesized at the contact nb, and the amplified outputs of the preamplifiers 30e to 30h are added at the contact nc. Additive synthesis. Further, the respective addition outputs are output via the output lines LAa to LAc, and are added and synthesized at the contact point NA in accordance with the ON / OFF states of the switches SW1 and SW2, and input to the main amplifier 40 at the subsequent stage.

  Here, each amplification output output from the preamplifiers 30a to 30h via the output lines La to Lh is a signal based on a detection signal obtained under substantially the same conditions (monitoring substantially the same detection area substantially simultaneously). Therefore, by connecting these output lines La to Lh at the contacts na to nc and NA, the amplified outputs are integrated and the signal-to-noise ratio (SN ratio; hereinafter referred to as “S / N”). ) Can provide improved output.

(Le) Switch control unit 71
For example, based on a command from the signal processing unit PRO, the switch control unit 71 controls the ON / OFF states of the switches SW1 and SW2 in the signal amplification unit AMP, and outputs the output lines La to Lh from the preamplifiers 30a to 30h. Are switched and controlled (hereinafter referred to as “addition amplification processing setting state”).

  As described above, in the fire detector according to the present embodiment, the amplified output from the preamplifiers 30a to 30h is added, and the above-described fire determination process is executed using the added amplified output amplified by the main amplifier 40. . In addition, the contamination state of the transparent window 11 disposed in front of the detection sensor is detected periodically or based on a test command from the outside, and the emission energy of the test light source is set and controlled according to the contamination state. At the same time, the setting state of the addition amplification processing in the signal amplifier AMP is switched and the detection sensitivity as the fire detector is appropriately set.

Here, the amplification effect in the fire detector according to the present embodiment will be described in detail with reference to the drawings.
FIG. 15 is a state diagram illustrating a setting state in the addition amplification unit applied to the fire detector according to the present embodiment. Here, it demonstrates, referring suitably the structure of the fire detector shown in FIG.

  In the fire detector according to the present embodiment, each of the light receiving elements 10a to 10h provided in the sensor unit SEN has a substantially uniform detection sensitivity characteristic, and monitors substantially the same detection area substantially simultaneously. The detection signals Sa to Sh output from the light receiving elements 10a to 10h are obtained as substantially equivalent signals (Sa≈Sb≈Sc≈Sd≈Se≈Sf≈Sg≈Sh). When the signal components Aa to Ah in a predetermined frequency band are extracted from the detection signals Sa to Sh and amplified by the preamplifiers 30a to 30h and the main amplifier 40, the signal components Aa to Ah are converted into the preamplifiers 30a to 30h. The signal is amplified with an amplification factor set to. In the present embodiment, the amplification factors of the preamplifiers 30a to 30h are all assumed to be the same.

  Here, as shown in FIG. 15A, when the switches SW1 and SW2 are in the OFF state, the output lines La and Lb of the preamplifiers 30a and 30b are coupled and connected at the contact NA through the contact na. Therefore, the amplified outputs from the preamplifiers 30a and 30b are added and combined (that is, integrated), and the signal level of the original fire detection component appearing in substantially the same band is increased approximately twice, so that the main amplifier 40 Is output.

  On the other hand, the noise components included in the amplified outputs from the preamplifiers 30a and 30b are added and synthesized (integrated) by the configuration in which the output lines La and Lb are coupled and connected at the contact na, so that the signal of the original fire detection component is obtained. Compared with the level, the increase rate is relatively suppressed and output. Therefore, the influence of the noise component on the original fire detection component in the fire determination process can be greatly suppressed.

  As described above, the signal amplifying unit AMP shown in the present embodiment can increase only the original fire detection component and relatively suppress the noise component in the light receiving elements 10a to 10h. The fire detection components of the two are based on the fact that the noise components have a relatively low correlation while the fire detection components have a close correlation by detecting the same object (flame) at the same time It is.

  When the state of contamination of the translucent window 11 arranged in front of the sensor unit SEN progresses and the light reception output level sent to the signal processing unit PRO becomes a predetermined value or less, the switch control unit 71. By switching the switch SW1 to the ON state, the output lines La to Ld of the preamplifiers 30a to 30d are coupled to each other at the contact NA via the contacts na and nb (additional synthesis) as shown in FIG. Thus, the output level of the original fire detection component is approximately doubled and output to the main amplifier 40.

  Similarly, as shown in FIG. 15C, by switching the switches SW1 and SW2 to the ON state, the output lines La to Lh of the preamplifiers 30a to 30h are coupled and connected (added and synthesized) at the contact NA. As a result, the output level of the original fire detection component is increased by a factor of approximately four and output to the main amplifier 40.

Therefore, by switching the switches SW1 and SW2 according to the contamination state of the translucent window 11, a desired signal level can be obtained without changing (increasing) the amplification factors of the preamplifiers 30a to 30h and the main amplifier 40. It is possible to obtain a light receiving output level amplified by the above.
In addition, the S / N in the case where such signal components Aa to Ah are added and amplified generally improves to √8 times by adding and synthesizing (integrating) the outputs from m = 8 light receiving elements. Can do.

  Therefore, by adding and amplifying the detection outputs from the plurality of light receiving elements, the amplification factor required for the main amplifier 40 to realize the signal amplification factor equivalent to the conventional one can be reduced and the original fire can be reduced. It is possible to amplify only the detection component well, to make the original fire detection component more obvious, to greatly improve the S / N of the added amplification output input to the signal processing unit PRO, and to make the fire more accurate Judgment processing can be performed.

In the present embodiment, an example is described in which the sensor unit SEN and the filter unit FLT made of multiple elements are applied to the fire detector (FIG. 1) according to the first embodiment having a single light receiving output processing circuit. However, the present invention is not limited to this configuration, and may be applied to the second and third embodiments.
In addition, the fire detector according to each of the above-described embodiments can be installed in any space as long as it determines fire occurrence by detecting radiant energy obtained by observing a flame. However, the present invention is not limited to the fire detector installed on the inner wall surface of the tunnel described above.

It is a schematic block diagram which shows 1st Embodiment of the fire detector which concerns on this invention. It is a functional block diagram which shows schematic structure of the signal processing part applied to the fire detector which concerns on this embodiment. It is a correlation table which shows an example of the correlation with the light emission level of the test light source LGT, the light reception relative output, and the contamination stage of the translucent window 11, which is applied to the contamination compensation process of the fire detector according to the present embodiment. It is a correlation table which shows the correlation with a light emission level, a light reception relative output, and the pollution state of a translucent window in the pollution compensation process in a prior art. FIG. 5 is a correlation diagram showing a relationship between a fouling stage and a received light relative output when the correlation table shown in FIG. 4 is applied. FIG. 4 is a correlation diagram showing a relationship between a fouling stage and a received light relative output when the correlation table shown in FIG. 3 is applied. It is a functional block diagram which shows the function test mode (initial registration process state and pollution compensation process state) of the fire detector which concerns on this embodiment. It is a functional block diagram which shows the fire monitoring mode (fire determination process) of the fire detector which concerns on this embodiment. It is a flowchart which shows the procedure of transfer to the functional test mode from the fire monitoring mode applied to the fire detector which concerns on this embodiment. It is a flowchart which shows the procedure of the pollution compensation process applied to the fire detector which concerns on this embodiment. It is a schematic block diagram which shows 2nd Embodiment of the fire detector which concerns on this invention. It is a schematic block diagram which shows 3rd Embodiment of the fire detector which concerns on this invention. It is a schematic block diagram which shows 4th Embodiment of the fire detector which concerns on this invention. It is a figure which shows the structural example of the sensor part applied to the fire detector which concerns on this embodiment, and the example of arrangement | positioning of a light receiving element. It is a state diagram which shows the setting state in the addition amplification part applied to the fire detector which concerns on this embodiment. It is a schematic block diagram of the fire detector for tunnels generally used conventionally. It is a schematic sectional drawing which shows the relationship between the airflow which arises in a tunnel, and the adhesion state of the dirt to the fire detector in a prior art. It is a functional block diagram which shows schematic structure of the radiation type | mold (optical type) fire detector to which pollution compensation processing is applied.

Explanation of symbols

11 Translucent window 12 Test light translucent window 10, 10A, 10B, 10a to 10h Light receiving element 20, 20A, 20B, 20a to 20h Frequency filter 30, 30A, 30B, 30a to 30h Preamplifier 40, 40A, 40B, Main amplifier 50, 50A, 50B A / D conversion unit 60A Fire determination unit 60B Fouling determination unit 61 Correlation table 62 Storage unit 63 Light emission level control unit 70 Amplification control unit 71 Switch control unit 80 Test light source control unit LGT Test light source SEN, SENA , SENB Sensor unit FLT, FLTA, FLTB Filter unit AMP, AMPA, AMPB Signal amplification unit CIRA, CIRB Light reception output processing circuit PRO Signal processing unit SW1, SW2 switch

Claims (8)

A detection sensor disposed in the translucent window, which converts light energy into an electrical signal; a fire determination means for executing a predetermined fire determination process based on a detection signal from the detection sensor; and the translucency The contamination detection sensor disposed in the window and the test light projected from a predetermined test light source are received by the contamination detection sensor through the light transmission window, thereby transmitting the light transmission property. In a fire detector comprising a pollution compensation means for detecting a pollution condition of a window and executing a predetermined pollution compensation process,
The fire detector according to claim 1, wherein the stain compensation means variably controls the emission energy of the test light emitted from the test light source in accordance with a stain state of the translucent window. The contamination compensation means receives the test light having a predetermined light emission energy with a signal level of an output signal output from the contamination detection detection sensor as a reference value when the translucent window is in an uncontaminated state. Determining whether a relative value of the output signal output from the contamination detection sensor with respect to the reference value is within a predetermined threshold range corresponding to the predetermined emission energy, and the determination result The fire detector according to claim 1, wherein the emission energy is variably controlled based on the above. The fouling compensation means stores at least information on the signal level of the output signal output from the fouling detection sensor when the translucent window is not fouled and the variably controlled emission energy. The fire detector according to claim 2, further comprising a storage unit. The fire detector according to any one of claims 1 to 3, wherein the detection sensor and the detection sensor for contamination detection are constituted by a single sensor element. The fire detector according to any one of claims 1 to 3, wherein the detection sensor and the detection sensor for contamination detection are configured by independent and separate sensor elements. The fire detector according to claim 1, wherein the test light source is driven to emit light at a flicker frequency unique to a flame. The fire detector according to claim 1, wherein the test light source is driven to emit light at a frequency different from a flicker frequency unique to a flame. The fire detector according to claim 5 or 7, wherein an emission wavelength band of the test light source is different from a wavelength band detected by the detection sensor during a fire determination process.

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