Fire prevention equipment and fire detection methods

Abstract

This allows for more reliable identification of fire smoke and non-fire smoke, thereby more effectively preventing false alarms. [Solution] In the detector 12, the signal detection unit 16 detects a first signal and a second signal obtained by receiving scattered light with different scattering angles and wavelengths. The identification unit 20 identifies whether the smoke is from a fire or not based on the detected values ​​and increasing / decreasing trends of the first and second signals, and identifies whether the non-fire smoke is mist, steam, cigarette smoke, or dust according to the increasing / decreasing trend and the specific particle size. The detection output unit 22 outputs to the outside that there is a fire if the identification unit 20 identifies it as fire smoke, and outputs to the outside that non-fire smoke satisfying the fire detection conditions has been detected if it is identified as non-fire smoke and the fire detection conditions are met. The receiver 10 receives the information that non-fire smoke satisfying the fire detection conditions has been detected and displays warning information or environmental information indicating that mist, steam, cigarette smoke, or dust has been detected.

Description

Technical Field

[0001] The present invention relates to a disaster prevention facility provided with a sensor such as a smoke detector that detects a fire from the light action associated with smoke, and a fire detection method.

Background Art

[0002] Automatic fire alarm equipment plays a very important role in early fire extinguishing and evacuation guidance by early detection of fires, and is an essential equipment for protecting lives and property from fires and ensuring a safe social life. However, in conventional automatic fire alarm equipment, various factors other than fires, such as tobacco smoke, steam and smoke associated with cooking, steam from the bathroom, dust associated with construction or cleaning, and aerosol substances sprayed from insect repellent sprays, may also be detected, resulting in so-called false alarms, and reliability has become a problem.

[0003] In order to reduce false alarms in such automatic fire alarm equipment, methods such as changing the sensitivity level of smoke detectors and signal accumulation methods have been introduced. However, even if the sensitivity of smoke detectors is dulled or a method of delaying a fire alarm for a certain period of time is introduced, there are difficulties in early detection of fires, and there are also limitations in reducing false alarms.

[0004] Also, as a fire detection device such as a smoke detector that reduces false alarms and detects fires, a fire detection device that receives scattered light of light with different scattering angles and different wavelengths to identify the type of smoke is known (Patent Document 1).

[0005] For example, by using two light emitting elements to make the scattering angles of the scattered light from the detection target to the light receiving element different, a difference in scattered light due to the type of smoke is created. At the same time, by making the wavelengths of the light emitted from the two light emitting elements different, a difference in scattering characteristics due to wavelength is created. By giving a significant difference in the scattered light due to the type of smoke by the synergistic effect of this difference in scattering angle and difference in wavelength, the identification accuracy of the type of smoke is increased to prevent false alarms due to steam associated with cooking, etc. Also, for smoke caused by fires, it is possible to identify the type of combustibles such as black smoke fires and white smoke fires. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2004-325211 [Patent Document 2] Japanese Patent Publication No. 2020-035029 [Patent Document 3] Japanese Patent Publication No. 2020-135263 [Patent Document 4] International Publication No. 2019 / 189125 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, while such conventional fire detection devices that identify types of smoke can distinguish between, for example, black smoke fires and white smoke fires, they cannot be said to have sufficient identification capabilities for other sources of false alarms, such as cigarette smoke, steam and smoke from cooking, steam from bathrooms, dust from construction and cleaning, and mist sprays from insect repellent sprays.

[0008] The present invention aims to provide fire prevention equipment and a fire detection method that can more reliably distinguish between fire smoke and non-fire smoke, thereby more reliably preventing false fire alarms. [Means for solving the problem]

[0009] (Fire detection device 1) The present invention is a fire detection device that detects a target object by light and detects a fire, The system is characterized by having an identification unit that, when a target is detected, identifies whether the detected target is fire smoke or non-fire smoke based on the detected value of the target and the trend of increase or decrease of the detected value.

[0010] Here, "fire smoke" includes white smoke generated by smoldering fires and black smoke generated by combustion fires, while "non-fire smoke" includes mist sprayed from sprayers, steam generated in cooking or bathrooms, cooking fumes, cigarette smoke, aerosols which are mixtures of fine liquid or solid particles with surrounding gases, and dust generated during construction or cleaning. Furthermore, "trend of increase or decrease in detected values" includes, for example, the rate of increase or decrease of detected values ​​per unit time, and "rate of increase or decrease" includes "increase rate" which indicates the rate of increase in detected values, and "decrease rate" which indicates the rate of decrease.

[0011] (External output based on the identification result of fire detection device 1) The fire detection device 1 is further equipped with a detection output unit that outputs a message indicating a fire to the outside if the detected object identified by the identification unit is fire smoke, and does not output a message indicating a fire to the outside if the detected object is not fire smoke.

[0012] (Fire detection device 2) The present invention is a fire detection device for detecting fires in a monitored area, A signal detection unit detects a first signal obtained by irradiating a target to be detected in a monitoring area involving optical activity with light to generate scattered light, receiving scattered light of a first wavelength at a first scattering angle, and a second signal obtained by receiving scattered light of a second wavelength different from the first wavelength at a second scattering angle different from the first scattering angle. An increase / decrease trend detection unit that detects the increase / decrease trend of at least one of the first signal and the second signal, An identification unit identifies whether the detected object is fire smoke or non-fire smoke based on the first and second signals detected by the signal detection unit and the increase / decrease trend detected by the increase / decrease trend detection unit. It is characterized by the provision of [a feature].

[0013] (Comparison results and trends of increase / decrease between the first and second signals) The identification unit identifies whether the detected object is fire smoke or non-fire smoke based on the comparison result and increase / decrease trend of the first signal and the second signal.

[0014] Here, the "comparison result" indicates the result of comparing the first signal and the second signal under predetermined conditions, such as the comparison result of values at a predetermined timing, the comparison result of integrated values over a predetermined period, etc. Also, identifying that the detection target is "fire smoke" means detecting the occurrence of a fire, and identifying that the detection target is "non-fire smoke" means detecting that it is not a fire.

[0015] (Identification of Fire Smoke) When the detection target is fire smoke, the identification unit further identifies whether the detection target is black smoke or white smoke.

[0016] Here, identifying that the detection target is "black smoke" means detecting the occurrence of a fire with black smoke, and identifying that the detection target is "white smoke" means detecting the occurrence of a fire with white smoke.

[0017] (Identification Conditions for Fire Smoke) When the comparison result and the increasing / decreasing trend of the first signal and the second signal satisfy the predetermined black smoke identification conditions, the identification unit identifies that the detection target is black smoke, and when the comparison result and the increasing / decreasing trend of the first signal and the second signal satisfy the predetermined white smoke identification conditions, the identification unit identifies that the detection target is white smoke.

[0018] (Identification of Non-Fire Smoke) When the detection target is non-fire smoke, the identification unit identifies at least one of aerosol substances, steam, oil fumes, tobacco smoke, aerosols, and dust, and the others.

[0019] (Identification Conditions for Non-Fire Smoke) When the comparison result and the increasing / decreasing trend of the first signal and the second signal satisfy any of the predetermined identification conditions for each of aerosol substances, steam, oil fumes, tobacco smoke, aerosols, and dust, the identification unit identifies that the detection target is the one identified by the satisfied identification condition.

[0020] (Optical Settings of the Signal Detection Unit for the Two-Scattering-Angle Two-Wavelength Method) The signal detection unit detects at least a first signal under a first optical setting and detects a second signal under a second optical setting, The first optical setting is a setting that irradiates the detection target with light of a first wavelength and enables reception of scattered light of the first wavelength at a first scattering angle generated in the detection target, The second optical setting is a setting that irradiates the detection target with light of a second wavelength and enables reception of scattered light of the second wavelength at a second scattering angle generated in the detection target.

[0021] (External output based on the identification result of the fire detection device 2) In the fire detection device 2, further, when at least one of the first signal and the second signal detected by the signal detection unit satisfies a predetermined fire detection condition in a state where the identification unit has identified that the detection target is fire smoke, a detection output unit is provided that outputs to the outside that there is a fire, and when the detection target is identified as non-fire smoke and at least one of the first signal and the second signal detected by the signal detection unit satisfies the fire detection condition, the detection output unit does not output to the outside that there is a fire.

[0022] (Disaster prevention equipment 1) A disaster prevention equipment using the above-mentioned fire detection device 2, Comprising a receiver and a sensor that detects a fire and transmits a fire signal to the receiver, Characterized in that the sensor is provided with a signal detection unit, an increase / decrease trend detection unit, an identification unit, and a detection output unit.

[0023] (Disaster prevention equipment 2) A disaster prevention equipment using the above-mentioned fire detection device 2, Comprising a receiver and a sensor that detects a fire and transmits a fire signal to the receiver, The sensor is provided with a signal detection unit, Characterized in that the receiver is provided with an increase / decrease trend detection unit, an identification unit, and a detection output unit.

[0024] (Fire detection method 1) The present invention is a fire detection method for detecting a detection target by optical action and detecting a fire, The system is characterized by identifying whether the detected target is fire smoke or non-fire smoke based on the detected value of the target and the trend of increase or decrease of that detected value when the target is detected.

[0025] (External output based on the identification result of fire detection method 1) In fire detection method 1, if the identified detection target is fire smoke, a message indicating that there is a fire is output to the outside; if the identified detection target is not fire smoke, no message indicating that there is a fire is output to the outside.

[0026] (Fire detection method 2) The present invention is a fire detection method for detecting a fire in a monitored area, The signal detection unit irradiates the target to be detected in the monitoring area, which involves optical activity, with light to generate scattered light. It then detects a first signal obtained by receiving scattered light of a first wavelength at a first scattering angle, and a second signal obtained by receiving scattered light of a second wavelength different from the first wavelength at a second scattering angle different from the first scattering angle. The increase / decrease trend detection unit detects the increase / decrease trend of at least one of the first signal and the second signal. The identification unit identifies whether the detected object is fire smoke or non-fire smoke based on the first and second signals detected by the signal detection unit and the increase / decrease trend detected by the increase / decrease trend detection unit.

[0027] (External output based on the identification result of fire detection method 2) In fire detection method 2, the detection output unit further outputs a message indicating a fire to the outside when the detection target is identified as fire smoke by the identification unit and a predetermined fire detection condition is met based on at least one of the first signal and the second signal detected by the signal detection unit, but does not output a message indicating a fire to the outside when the detection target is identified as non-fire smoke by the identification unit and a fire detection condition is met based on at least one of the first signal and the second signal detected by the signal detection unit. [Effects of the Invention]

[0028] (Effectiveness of fire detection device 1) In the fire detection device 1 of the present invention, when a target to be detected in a monitoring area accompanied by light is detected, not only the detected value of the target but also the trend of increase or decrease in the detected value is detected, and by identifying whether it is fire smoke or non-fire smoke, the accuracy of identification (identification performance) can be improved.

[0029] Furthermore, if the system identifies the smoke as fire smoke, it will output a message indicating a fire to the outside, enabling early detection of the fire. On the other hand, if the system identifies the smoke as non-fire smoke, such as mist, steam, oil fumes, cigarette smoke, aerosols, or dust, it will not output a message indicating a fire to the outside, thereby reliably preventing false alarms that would otherwise be triggered by non-fire smoke and improving reliability.

[0030] (Effectiveness of fire detection device 2) In the fire detection device 2 of the present invention, in addition to the effects of the fire detection device 1 described above, the signal detection unit irradiates the target to be detected in the monitoring area with optical action with light to generate scattered light, detects a first signal obtained by receiving scattered light of a first wavelength at a first scattering angle and a second signal obtained by receiving scattered light of a second wavelength different from the first wavelength at a second scattering angle different from the first scattering angle, detects the increase / decrease trend in the increase / decrease trend in the increase / decrease trend detection unit and enables the identification unit to identify with high accuracy whether the detected target is fire smoke or non-fire smoke based on the first signal, the second signal and the increase / decrease trend.

[0031] (Comparison results of the first and second signals and the effect of the increasing / decreasing trend) Furthermore, the identification unit is capable of reliably identifying whether the smoke is from a fire or not, based on the comparison result and increasing / decreasing trend of the first and second signals.

[0032] (Effects of identifying fire smoke) Furthermore, the identification unit can identify with high accuracy whether the smoke from a fire is black smoke or white smoke when the comparison result and increase / decrease trend of the first signal and the second signal satisfy the identification conditions specific to black smoke or white smoke.

[0033] (Effects of identifying non-fire smoke) Furthermore, the identification unit can identify with high accuracy the type of smoke that is not caused by a fire, when the comparison result and increase / decrease trend of the first and second signals satisfy the specific identification conditions for each of the following: mist, steam, oil fumes, cigarette smoke, aerosols, and dust.

[0034] (Effect of the optical settings of the signal detection unit using a two-scattering-angle, two-wavelength method) Furthermore, by making the scattering angles of the scattered light from the detection target different between the first and second scattering angles, differences in scattering characteristics due to the scattering angle are created. Simultaneously, by making the wavelength of the light irradiated onto the detection target different between the first and second wavelengths, differences in scattering characteristics due to the wavelength are created. Based on the synergistic effect of these differences in scattering angles and wavelengths, and, for example, the increasing or decreasing trend of the first signal, it becomes possible to identify the type of smoke, whether from a fire or not, with greater accuracy.

[0035] (Effects of the first disaster prevention equipment) The present invention relates to a fire prevention system using the aforementioned fire detection device 2, comprising a receiver and a detector that detects a fire and transmits a fire signal to the receiver. By providing the detector with a signal detection unit, an increase / decrease trend detection unit, an identification unit, and a detection output unit, the system can be modified simply by changing the detector itself. Even with existing equipment, the system can be easily modified by removing the detector mounted on the detector base and replacing it with a detector equipped with a signal detection unit, an increase / decrease trend detection unit, an identification unit, and a detection output unit.

[0036] (Effects of the second disaster prevention equipment) The present invention relates to a fire prevention system using the aforementioned fire detection device 2, comprising a receiver and a detector that detects a fire and transmits a fire signal to the receiver. The detector is provided with a signal detection unit, and the receiver is provided with an increase / decrease trend detection unit, an identification unit, and a detection output unit. This eliminates the need to modify the detector and allows for modifications only to the receiver.

[0037] (Effectiveness of fire detection methods) The present invention provides a fire detection method that achieves the same effects as the fire detection device described above. [Brief explanation of the drawing]

[0038] [Figure 1] This is an explanatory diagram illustrating the basic concepts of the fire detection device, fire prevention equipment, and fire detection method of the present invention. [Figure 2] This is an explanatory diagram of a disaster prevention equipment showing a specific embodiment of the present invention, which corresponds to the P-type disaster prevention equipment shown in Figure 1. [Figure 3] This is an explanatory diagram showing the structure of the smoke detection unit that constitutes the signal detection unit. [Figure 4] This graph shows the relationship between the type of smoke and its rate of increase. [Figure 5] This is an explanatory diagram that shows, in list format, the particle size corresponding to the type of fire smoke and non-fire smoke, the identification criteria based on the ratio of the first detected value to the second detected value, and the identification criteria based on the rate of increase. [Figure 6] This is an explanatory diagram that shows, in list format, identification patterns of fire smoke and non-fire smoke types based on ratios and growth rates. [Figure 7] This is a flowchart illustrating the control operation according to the sensor embodiment shown in Figure 2. [Figure 8] This is an explanatory diagram illustrating other basic concepts of the fire detection device, fire prevention equipment, and fire detection method of the present invention, which detects fires on the receiver side. [Figure 9] This is an explanatory diagram of a disaster prevention equipment showing a specific embodiment of the present invention, targeting the R-type disaster prevention equipment corresponding to Figure 8. [Figure 10] Figure 9 is a flowchart showing the control operation of the R-type disaster prevention equipment embodiment in a time chart format. [Modes for carrying out the invention]

[0039] Embodiments of the fire detection device, fire prevention equipment, and fire detection method according to the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited by these embodiments.

[0040] [Basic Concepts of the Embodiment] Figure 1 is an explanatory diagram illustrating the basic concept of an embodiment of the present invention corresponding to the first fire prevention equipment. As shown in Figure 1, this embodiment generally relates to a fire detection device, the first fire prevention equipment, and a fire detection method. An embodiment corresponding to the second fire prevention equipment will be described separately.

[0041] A "fire detection device" is a device that detects fires in a monitored area, and the concept includes, for example, smoke detectors, fire detectors, and fire alarms.

[0042] Here, "monitoring area" refers to the area that is monitored by the fire detection device, and is a concept that includes a certain area of ​​outdoor or indoor space, such as rooms, corridors, and stairwells in a building.

[0043] The fire detection device is, for example, a detector 12 of a fire prevention system, which consists of a receiver 10 and a detector 12 connected by a signal line 14, and includes a signal detection unit 16, an increase / decrease rate detection unit 18, an identification unit 20, and a detection output unit 22.

[0044] The "signal detection unit 16" detects a first signal obtained by irradiating the target to be detected in the monitoring area with optical effects with light to generate scattered light, and receiving scattered light of a first wavelength at a first scattering angle, and a second signal obtained by receiving scattered light of a second wavelength different from the first wavelength at a second scattering angle different from the first scattering angle.

[0045] Here, "detection targets in the monitoring area" refer to substances that generate scattered light when light is shone upon them, and are classified into, for example, fire smoke (smoke from a fire) and non-fire smoke (smoke from non-fire sources). "Fire smoke" includes black smoke generated by combustion fires and white smoke generated by smoldering fires, while "non-fire smoke" includes atomized substances sprayed from sprayers, steam generated in cooking or bathrooms, oil fumes generated in cooking, cigarette smoke, aerosols (mixtures of minute liquid or solid particles with surrounding gases), and dust generated during construction or cleaning.

[0046] Furthermore, the "signal detection unit 16" detects a first signal using at least a first optical setting and a second signal using a second optical setting. The first optical setting is a setting that irradiates the detection target with light of a predetermined first wavelength, making it possible to receive scattered light of the first wavelength at a first scattering angle generated at the detection target. The second optical setting is a setting that irradiates the detection target with light of a predetermined second wavelength different from the first wavelength, making it possible to receive scattered light of the second wavelength at a second scattering angle generated at the detection target. By using these first and second optical settings, the scattering angle of the scattered light generated from the detection target is made different, creating a difference in scattering characteristics due to the scattering angle. At the same time, the wavelength of the light irradiated onto the detection target is made different, creating a difference in scattering characteristics due to the wavelength. Through the synergistic effect of the difference in scattering angle and the difference in wavelength, a significant difference in the light intensity of the scattered light depending on the type of fire smoke and non-fire smoke is created, thereby detecting the first and second signals.

[0047] The "increase / decrease rate detection unit 18" detects the increase / decrease rate as the increase / decrease trend of at least one of the first signal and the second signal detected by the signal detection unit 16. Here, "increase / decrease rate" is the rate at which the smoke concentration increases or decreases per unit time, and includes "increase rate" which indicates the rate of increase, and "decrease rate" which indicates the rate of decrease. The increase / decrease rate of the first signal or the second signal detected by the signal detection unit 16 will be unique to each type of smoke depending on the combustion characteristics of black smoke and white smoke, which are fire smoke, and will also be unique to each type of smoke depending on the generation characteristics of non-fire smoke such as mist, steam, oil smoke, cigarette smoke, aerosols, and dust. In this embodiment, the unit is set to [(% / m) / s] and the increase / decrease trend is detected based on the increase rate, which is a percentage, but it is sufficient to detect the increase / decrease trend from the increase / decrease situation, and it is not necessarily required to detect it by an increase rate or a percentage.

[0048] The "identification unit 20" identifies whether smoke is from a fire or not based on the first signal and the second signal detected by the signal detection unit 16 and the increase / decrease rate detected by the increase / decrease rate detection unit 18, and more specifically, based on the comparison result of the first signal and the second signal, for example, the ratio of the first signal and the second signal at a predetermined timing and the increase / decrease rate of the first signal.

[0049] Here, the identification unit 20 identifies whether the fire smoke is, for example, black smoke or white smoke. For example, if the ratio and rate of increase / decrease of the first signal and the second signal satisfy predetermined black smoke identification conditions, the detection target is identified as black smoke. If the ratio and rate of increase / decrease of the first signal and the first signal satisfy predetermined white smoke identification conditions, the detection target is identified as white smoke.

[0050] Furthermore, the identification unit 20 identifies whether the non-fire smoke is a mist, steam, oil fumes, cigarette smoke, aerosols, or dust. For example, if the ratio of the first signal to the second signal and the rate of increase or decrease of the first signal satisfy predetermined mist identification conditions, the unit identifies the detected object as a mist. Similarly, it identifies the type of non-fire smoke when the specific identification conditions for each type are met.

[0051] The "detection output unit 22" outputs a message indicating a fire to the outside when the identification unit 20 has identified the smoke as fire smoke and the predetermined fire detection conditions are met based on at least one of the first signal and the second signal detected by the signal detection unit 16. On the other hand, when the identification unit 20 has identified the smoke as non-fire smoke and the fire detection conditions are met based on at least one of the first signal and the second signal detected by the signal detection unit 16, it does not output a message indicating a fire to the outside, thereby preventing false fire alarms.

[0052] Here, "fire detection conditions" refer to predetermined threshold conditions or predetermined accumulation conditions for detecting a fire in response to, for example, the first signal or the second signal. A threshold condition means, for example, that the detected value is equal to or exceeds a predetermined threshold, and an accumulation condition means, for example, that the state satisfying the predetermined threshold condition continues for a predetermined time or beyond a predetermined time.

[0053] The following explanation will describe the specific details assuming that the "monitoring area" is a "room in a building," the "increase / decrease rate detection unit 18" "detects the increase rate α of the first detected value A1 based on the first signal," the "identification unit 20" "identifies whether it is fire smoke or non-fire smoke based on the ratio R of the first detected value A1 and the second detected value A2 based on the second signal at a predetermined timing and the increase rate α of the first detected value A1," the types of "fire smoke" are "black smoke and white smoke," the types of "non-fire smoke" are "atomized matter, steam, cigarette smoke, and dust," and the "detection output unit 22" "determines whether the fire detection conditions are met based on the first detected value A1."

[0054] [Specific details of the embodiment] The specific details of the embodiments of the fire detection device, fire prevention equipment, and fire detection method will be explained in more detail. The details will be explained in the following sections. AP-type disaster prevention equipment b. receiver c.sensor d. Signal detection unit d1. Structure of the first smoke detection section d2.Second smoke detection section structure d3. Light emission drive and light detection e. Sensor control unit f. Increase / decrease rate detection unit g. Identification unit g1. Identification based on the ratio of the first detected value to the second detected value. g2. Identification by adding the growth rate to the ratio. h. Detection output section h1. Output indicating that there is a fire. h2. Suppression of output indicating a fire. h3. Fire Detection Conditions h4. Transmission of fire alarm signals containing identification information i. Control operation of the sensor j. Basic concepts of other embodiments kR-type disaster prevention equipment k1.sensor k2. Receiver k3. Transmission control Control operation of k4.R type disaster prevention equipment l. Modified versions of the present invention

[0055] [aP-type disaster prevention equipment] Figure 2 is an explanatory diagram showing a specific embodiment of the present invention, corresponding to a P-type (Proprietary-type) fire prevention system, as shown in Figure 1. Here, a "P-type fire prevention system" is a system in which the receiver 10 monitors for fires on a per-signal line basis, to which the detectors 12 are connected.

[0056] As shown in Figure 2, the P-type fire prevention system of this embodiment comprises a receiver 10 and multiple detectors 12. Note that Figure 2 shows one detector 12 as a representative example. The receiver 10 is installed in a manager's room or disaster prevention center, and the multiple detectors 12 are connected to a signal line 14 that runs from the receiver 10 to a monitoring area such as a room in the building. The signal line 14 that runs from the receiver 10 comprises a positive signal line 14a and a negative signal line (common signal line) 14b, supplying power from the receiver 10 to the detectors 12 and transmitting a fire alarm signal from the detectors 12 to the receiver 10.

[0057] [b. Receiver] The receiver 10 of the P-type fire prevention equipment will be described in more detail. The receiver 10 comprises a receiver control unit 40, a line receiving unit 42, a display unit 44, an operation unit 46, an alarm unit 48, and a transmission unit 50. The line receiving unit 42 is provided for each signal line 14 that is drawn out in a monitoring area, for example, by floor of the building, and receives fire alarm signals from the detectors 12 and outputs them to the receiver control unit 40.

[0058] The receiver control unit 40 is composed of a computer circuit equipped with a CPU, memory, and various input / output ports, and performs a fire alarm operation when it detects the reception of a fire alarm signal from any of the line receiving units 42. The fire alarm operation of the receiver control unit 40 activates the fire indicator light on the display unit 44 and the area indicator light that shows the area where the fire occurred, as well as the alarm unit 48 which outputs a main audible alarm including an alarm voice message and performs an area audible alarm by activating the area audible device installed in the monitoring area where the fire occurred, and also instructs the transmission unit 50 to perform interlocking control of smoke control equipment, etc.

[0059] [c.Sensor] The configuration of the detector 12, which functions as a fire detection device, will now be described in more detail. The detector 12 comprises a signal detection unit 16, a detector control unit 24, an alarm circuit unit 26, a power supply unit 28, a light emission drive unit 36, and a light receiving amplification unit 38. Each of these will be described in detail below.

[0060] [d. Signal detection unit] The signal detection unit 16 of the detector 12 will be described in more detail. The signal detection unit 16 detects a first signal obtained by irradiating the fire smoke or non-fire smoke to be detected in the monitoring area with light of a first wavelength λ1 using a first optical setting and receiving the scattered light at a first scattering angle θ1, and a second signal obtained by irradiating with light of a second wavelength λ2, which is different from the first wavelength λ1, using a second optical setting and receiving the scattered light at a second scattering angle θ2, which is different from the first scattering angle θ1. Its configuration and structure are arbitrary, but for example, a first light-emitting element 30, a second light-emitting element 32, and a light-receiving element 34 are arranged in a smoke detection section, which is a space inside the detector into which outside air flows but outside light is blocked.

[0061] Figure 3 is an explanatory diagram showing the smoke detection section structure of the signal detection unit 16, with Figure 3(A) showing the structure of the first smoke detection section and Figure 3(B) showing the structure of the second smoke detection section.

[0062] (d1. 1st smoke detection section structure) The structure of the first smoke detection unit, which constitutes the signal detection unit 16, will be described in more detail. As shown in Figure 3(A), the structure of the first smoke detection unit has a first light-emitting element 30, a second light-emitting element 32, and a light-receiving element 34 arranged in a smoke detection unit 31 into which smoke from the outside flows in but external light is blocked, and the optical axes 30a, 32a, and 34a of each are arranged in the same plane, forming a planar arrangement.

[0063] The first light-emitting element 30 uses a near-infrared LED and emits light with a central wavelength of 600 nm or more as the first wavelength λ1, for example, light with λ1 = 900 nm. Furthermore, the first scattering angle θ1 of the first light-emitting element 30 with respect to the intersection point P of the optical axis 30a of the first light-emitting element 30 and the optical axis 34a of the photodetector element 34 is set to a predetermined angle in the range of 20° to 70°, for example, θ1 = 30°. In the following explanation, "first scattering angle θ1" may be referred to as "forward scattering angle θ1".

[0064] The second light-emitting element 32 uses a visible light LED and emits light with a second wavelength λ2, specifically light with a central wavelength of 500 nm or less, for example, light with λ2 = 500 nm. Furthermore, the second scattering angle θ2 of the second light-emitting element 32 with respect to the intersection point P of its optical axis 32a and the optical axis 34a of the photodetector 34 is set to a predetermined angle in the range of 110° to 160°, which is greater than the first scattering angle θ1 of the first light-emitting element 30 and the photodetector 34, for example, θ2 = 120°. In the following explanation, "second scattering angle θ2" may be referred to as "backscattering angle θ2".

[0065] The photodetector 34 uses a photodiode that is sensitive from the infrared region to the visible light region. The light emission drive of the first light-emitting element 30 and the second light-emitting element 32 is arbitrary, but for example, they are driven to emit light alternately at predetermined intervals. When the light emitted by the first light-emitting element 30 irradiates the smoke flowing into point P with light of the first wavelength λ1, the forward scattered light from the smoke corresponding to the first scattering angle θ1 is incident on the photodetector 34 and received, and the first signal is detected as a received signal.

[0066] Furthermore, when the light emitted by the second light-emitting element 32 irradiates the smoke flowing into point P with light of the second wavelength λ2, the backscattered light from the smoke corresponding to the second scattering angle θ2 is incident on the photodetector 34 and received, and the second signal is detected as a received signal.

[0067] (d2.Second smoke detection section structure) The second smoke detection unit structure, which constitutes the signal detection unit 16, will now be described in more detail. As shown in Figure 3(B), the second smoke detection unit structure has a light-emitting element 35, a first light-receiving element 34 (34-1), and a second light-receiving element 34 (34-2) arranged within the smoke detection unit 31. In this embodiment, the optical axes 35a, 34-1a, and 34-2a are arranged in a planar configuration within the same plane.

[0068] The light-emitting element 35 emits light from the infrared region to the visible light region, and its structure and type are arbitrary, but for example, a white LED (white light-emitting diode) is used. A white LED, for example, combines a blue LED and a phosphor, and the light from the blue LED is passed through the phosphor to emit white light. This emitted color includes light of a first wavelength λ1 = 900 nm and light of a second wavelength λ2 = 500 nm, and the smoke detection unit 31 can be simultaneously irradiated with light of the first wavelength λ1 and the second wavelength λ2.

[0069] Furthermore, a two-color LED (two-color light-emitting diode) can also be used as the light-emitting element 35 in this embodiment. The two-color LED comprises a first light-emitting chip that emits light at a first wavelength λ1 = 900 nm and a second light-emitting chip that emits light at a second wavelength λ2 = 500 nm. By driving both simultaneously, the light at the first wavelength λ1 and the second wavelength λ2 can be simultaneously irradiated into the smoke detection unit 31.

[0070] The first photodetector 34 (34-1) uses a photodiode sensitive to a first wavelength λ1, and the second photodetector 34 (34-2) uses a photodiode sensitive to a second wavelength λ2.

[0071] Furthermore, the first photodetector 34(34-1) and the second photodetector 34(34-2) may be broadband photodiodes sensitive to the infrared wavelength band to the visible light wavelength band, with filter layers that receive only the wavelength bands of the first wavelength λ1 and the second wavelength λ2 provided on the PD molding (transparent cover member), or filters that transmit the wavelengths of the first wavelength λ1 and the second wavelength λ2 may be placed in front of the broadband photodiode.

[0072] The first photodetector 34(34-1) has its first scattering angle θ1 set to a predetermined angle in the range of 20° to 70°, for example, θ1 = 30°, with respect to the intersection point P of its optical axis 34-1a and the optical axis 35a of the light-emitting element 35. When light containing the first wavelength λ1 from the light-emitting element 35 is irradiated onto smoke flowing into point P, the forward scattered light from the smoke corresponding to the first scattering angle θ1 is incident on the first photodetector 34(34-1) and received, and the first signal is detected as a received signal.

[0073] Furthermore, the second light-receiving element 34(34-2) sets its second scattering angle θ2 with respect to the intersection point P of its optical axis 34-2a and the optical axis 35a of the light-emitting element 35 to a predetermined angle in the range of 110° to 160°, which is greater than the first scattering angle θ1 of the first light-receiving element 34(34-1) and the light-emitting element 35, for example, θ2 = 120°. When light containing the second wavelength λ2 from the light-emitting element 35 is irradiated onto the smoke flowing into point P, the backscattered light from the smoke corresponding to the second scattering angle θ2 is incident on the second light-receiving element 34(34-2) and received, and the second signal is detected as a received signal.

[0074] (d3. Light emission drive and light detection) The signal detection unit 16 in Figure 2 is equipped with the first smoke detection unit structure shown in Figure 3(A), and therefore has a first light-emitting element 30, a second light-emitting element 32, and a light-receiving element 34. The first light-emitting element 30 and the second light-emitting element 32 are driven to emit light alternately at predetermined intervals by the light-emitting drive unit 36, and the first signal and the second signal, which are received signals output sequentially from the light-receiving element 34, are amplified by the light-receiving amplification unit 38 and read into the sensor control unit 24, and based on the first signal and the second signal, a first detection value A1 and a second detection value A2 corresponding to the smoke concentration are obtained.

[0075] [e. Sensor Control Unit] The detector control unit 24 of the detector 12 will now be described in more detail. The detector control unit 24 is composed of a computer circuit equipped with a CPU, memory, and various input / output ports, and as functions realized by the execution of a program, it has the functions of the increase / decrease rate detection unit 18, the identification unit 20, and the detection output unit 22, which are components of the fire detection device according to this embodiment.

[0076] The sensor control unit 24 reads the first and second signals from the light receiving amplifier 38 by A / D conversion synchronized with the timing of the light emission drive of the first light-emitting element 30 and the second light-emitting element 32 to acquire the first detected value A1 and the second detected value A2. The increase / decrease rate detection unit 18 detects the increase rate α based on the first detected value A1, and then the identification unit 20 determines whether it is fire smoke (black smoke or white smoke) or non-fire smoke based on the first detected value A1, the second detected value A2, and the increase rate α of the first detected value A1. The system identifies whether the substance is a mist, steam, cigarette smoke, or dust, and then, when the detection output unit 22 determines that the first detection value A1 satisfies the predetermined fire detection conditions while the substance is identified as fire smoke, it activates the alarm circuit unit 26 to output a message indicating that there is a fire (either a black smoke fire or a white smoke fire). This involves short-circuiting the positive signal line 14a and the negative signal line 14b to a low impedance, allowing a fire alarm current to flow and sending a fire alarm signal to the receiver 10. On the other hand, even if the detection output unit 22 determines that the first detection value A1 satisfies the predetermined fire detection conditions while the substance is identified as non-fire smoke, it does not activate the alarm circuit unit 26, thus preventing false alarms.

[0077] [f. Increase / Decrease Rate Detection Unit] The increase / decrease rate detection unit 18 of the sensor 12 will be explained in more detail. The increase / decrease rate detection unit 18 detects the increase rate α of, for example, the first detected value A1 acquired by the sensor control unit 24. The increase rate α is arbitrary, but for example, the rate at which the first detected value A1 corresponding to the smoke concentration increases per predetermined unit time, for example, 1 second, is detected as the increase rate α [(% / m) / s].

[0078] The increase rate α of the first detected value A1 corresponding to fire smoke depends on the smoke diffusion rate (rise rate) according to the characteristics of the fire that occurred. For example, in a combustion fire accompanied by black smoke, a large amount of smoke is generated due to the rapid combustion, and the increase rate α is large because the diffusion rate is fast. On the other hand, in a smoldering fire accompanied by white smoke, the amount of smoke generated is small due to the slow combustion, and the diffusion rate is slow, so the increase rate α is smaller compared to black smoke.

[0079] On the other hand, for non-fire smoke detection targets, the increase rate α is lower than that of white smoke caused by smoldering fires. For example, among these, a mist sprayed by insect repellent sprays, etc., is sprayed by gas pressure, so the increase rate α is relatively large. Also, steam from cooking and steam from opening and closing bathroom doors have a smaller increase rate α compared to spray sprays. Tobacco smoke is smoke that drifts in smoking areas, so the increase rate α is considerably smaller than that of white smoke from smoldering fires. Furthermore, dust is stirred up during construction and cleaning, so the increase rate α is even smaller.

[0080] Figure 4 is a time chart showing the time evolution of the rate of increase when black smoke, white smoke, sprayed mist, steam, cigarette smoke, and dust are generated from the detected object at a constant diffusion rate unique to each. As shown in Figure 4, the rate of increase of black smoke, which has characteristic a and is the smoke of explosively burning oil fires, is the largest, followed by the rate of increase of white smoke, which has characteristic b and is the smoke of smoldering fires that cause bedding to freeze. For non-fire smoke, the rate of increase decreases in the order of sprayed mist (characteristic c), steam (characteristic d), cigarette smoke (characteristic e), and dust (characteristic f), based on the magnitude of the diffusion rate.

[0081] Furthermore, since the actual diffusion rate of each detected object is not constant but changes randomly, the actual rate of increase in smoke concentration does not follow a linear (constant) pattern, but rather changes randomly over time. In addition, the relationship between the rate of increase of each detected object's actual characteristics a-f may be reversed with respect to adjacent characteristics, and a simple comparison of the rate of increase α may not allow for highly accurate identification of the type of object.

[0082] [g. Identification section] The identification unit 20 of the detector 12 will now be explained in more detail. The identification unit 12 identifies the type of smoke, such as whether it is fire smoke or non-fire smoke, based on the first detection value A1 and the second detection value A2 acquired by the detector control unit 24, and the increase rate α detected by the increase / decrease rate detection unit 18. The type of smoke is arbitrary, but as an example, it identifies whether fire smoke is black smoke or white smoke, and whether non-fire smoke is mist, steam, cigarette smoke, or dust.

[0083] (g1. Identification based on the ratio of the first detected value to the second detected value) When light is shone on smoke that has entered the smoke detection unit 31, which constitutes the signal detection unit 16 in Figure 3(A), the scattered light will be Mie scattering if the size (particle diameter) of the smoke particles is greater than or equal to the wavelength of light, and Rayleigh scattering if the size (particle diameter) of the smoke particles is smaller than the wavelength of light. In Mie scattering, as is well known, the forward scattered light is greater than the back scattered light, and the forward scattering increases as the particle diameter increases. In Rayleigh scattering, the forward and back scattered light are distributed evenly and are minimized at a scattering angle of 90°. Generally, smoke particles are distributed around the wavelength of the irradiated light, so the scattering of light is a composite scattering of Mie scattering and Rayleigh scattering, and at the very least, the characteristic of Mie scattering, in which the forward scattered light is greater than the back scattered light, is observed.

[0084] Therefore, based on the difference in scattering efficiency, there is a difference between the first detected value A1 of forward scattered light received at the first scattering angle θ1 = 30° after irradiation with light of the first wavelength λ1 = 900 nm, and the second detected value A2 of backscattered light received at the second scattering angle θ2 = 120° after irradiation with light of the second wavelength λ2 = 500 nm. A1>A2 There is a relationship in which forward-scattered light is greater than back-scattered light.

[0085] Furthermore, since the white smoke and black smoke, which are fire smoke that flows into the smoke detection unit 31, have different particle sizes, the first detection value A1 and the second detection value A2 will be different values, and by comparing the two, the type of smoke can be identified. Identifying the type of smoke by comparing the first detection value A1 and the second detection value A2 is arbitrary, but for example, the sensor control unit 24 reads the first and second signals from the light receiving amplifier unit 38 by A / D conversion synchronized with the timing of the light emission drive of the first light-emitting element 30 and the second light-emitting element 32, and from the first detection value acquired at a predetermined timing and the second detection value A2 acquired at the next timing, R = A1 / A2 By calculating the ratio R, the type of smoke can be identified.

[0086] White smoke is the whitish smoke produced when, for example, a cotton wick is burned, and is also called smoldering smoke. Its particle size is concentrated at, for example, 2-3 μm. Black smoke, on the other hand, is the dark smoke produced when, for example, kerosene is burned, and is also called combustion smoke. Its particle size is smaller than that of white smoke, concentrated at, for example, 1-2 μm. For this reason, the ratio R of the first detection value A1 to the second detection value A2 for white smoke with larger particle sizes is, for example, R=8.0. In contrast, the ratio R of the first detection value A1 to the second detection value A2 for black smoke with smaller particle sizes is, for example, R=2.3.

[0087] Therefore, there is a sufficient difference in the ratio R between the first detection value A1 and the second detection value A2 between white smoke (smoking smoke) and black smoke (combustion smoke). By setting the first identification threshold Rth1 for distinguishing between white smoke and black smoke to a value in the range of 5 to 6, for example Rth1=5, it is possible to identify white smoke if the ratio R is Rth1 or greater, and black smoke if it is less than Rth1.

[0088] Non-fire smoke, such as mist, steam, cigarette smoke, and dust, is known to have its own unique particle size. For example, the particle size of sprayed mist and steam is larger than that of fire smoke; for instance, sprayed mist is concentrated at 6-8 μm, and steam at 4-6 μm. Cigarette smoke is similar in size to the white smoke of a fire, concentrated at 2-3 μm. Furthermore, dust particles are distributed over a wide range of sizes, for example, from 1 to several tens of μm.

[0089] Therefore, in the case of sprayed mist or steam, the particle size is sufficiently larger than that of fire smoke particles, so the ratio R of the first detection value A1 to the second detection value A2 will be a large value, for example, 10 or more. For this reason, a second identification threshold Rth2 is set to a value in the range of 10 to 12, for example Rth2=12, to distinguish whether it is white smoke or mist or steam, and if it is higher than this value, it can be identified as mist or steam.

[0090] However, since the particle size of cigarette smoke is similar to that of white smoke, it may not be possible to distinguish with high accuracy whether it is white smoke or cigarette smoke based on the ratio R of the first detection value A1 to the second detection value A2. Similarly, in the case of dust, the particle size is widely distributed and includes the particle sizes of both white and black smoke, so it may not be possible to distinguish with high accuracy whether it is dust or fire smoke based on the ratio R of the first detection value A1 to the second detection value A2.

[0091] Furthermore, there may be overlaps in particle size between white smoke and mist or steam, making it difficult to distinguish with high accuracy whether it is white smoke, steam, or mist based on the ratio R of the first detection value A1 to the second detection value A2.

[0092] (g2. Classification by adding the growth rate α to the ratio R) The identification unit 20 performs identification by adding an increase rate α to the ratio R of the first detected value A1 and the second detected value A2, as identification based on this ratio has a low accuracy in distinguishing between fire smoke and non-fire smoke.

[0093] Figure 5 shows a list of identification conditions for particle size, ratio R=A1 / A2, and increase rate α for each type of target being detected. Figure 5(A) shows the identification conditions in a generalized manner, while Figure 5(B) shows numerical examples of the identification conditions.

[0094] In Figure 5, the particle sizes of black smoke and white smoke (fire smoke), and non-fire smoke such as mist, steam, cigarette smoke, and dust, are distributed within the range shown in the section "g1. Identification based on the ratio of the first and second detected values" mentioned above. The identification conditions for the ratio R are set based on the threshold range shown in the figure, using a first identification threshold Rth1 to distinguish between white smoke and black smoke, and a second identification threshold Rth2 to distinguish between white smoke and mist or steam.

[0095] Furthermore, the identification conditions for the increase rate α are set as follows: αth5 is the increase rate threshold for distinguishing between black smoke and white smoke; αth4 is the increase rate threshold for distinguishing between white smoke and mist; αth3 is the increase rate threshold for distinguishing between mist and steam; αth2 is the increase rate threshold for distinguishing between steam and cigarette smoke; and αth1 is the increase rate threshold for distinguishing between cigarette smoke and dust (where αth1 < αth2 < αth3 < αth4 < αth5), and threshold conditions are set according to the threshold range shown in the figure. Specifically, the identification conditions for the increase rate α are set according to the characteristics a to f in Figure 4 shown in the "f. Increase / Decrease Rate Detection Unit" section above.

[0096] The identification process by the identification unit 20 is based on the ratio R = A1 / A2 obtained from the first detected value A1 and the second detected value A2, and the increase rate α of the first detected value A1. For example, by referring to the list in Figure 5(B), if the detected object identified by the identification condition of ratio R matches the detected object identified by the identification condition of increase rate α, it is identified as a matching object.

[0097] Although the procedures and processes for the identification unit 20 to identify the detection target are arbitrary, for example, the identification table shown in FIG. 6 generated based on FIG. 5 is used. The identification table in FIG. 6 divides the identification conditions into three categories: when the ratio R is 5 or less (R ≦ 5), when it is between 5 and 12 (5 < R ≦ 12), and when it is 12 or more (12 ≦ R). The increase rate α is divided into identification conditions: when it is 0.1 or less (α ≦ 0.1), when it is between 0.1 and 0.2 (0.1 < α ≦ 0.2), when it is between 0.2 and 0.3 (0.2 < α ≦ 0.3), when it is between 0.3 and 0.4 (0.3 < α ≦ 0.4), and when it is 0.5 or more (0.5 ≦ α). For the types of objects such as black smoke, white smoke, aerosol, steam, tobacco smoke, and dust, the satisfaction of the identification conditions is indicated by a filled circle.

[0098] Here, when the identification conditions indicated by the filled circle are satisfied, it is set as bit "1", and when not satisfied, it is set as bit "0". By allocating them to 9 bits of bits b0 to b8, it can be represented by an identification bit code.

[0099] That is, the identification unit 20 sets the corresponding bits bi (b6 to b8) of the identification conditions (threshold range) that the ratio R satisfies and the corresponding bits bj (b0 to b7) of the identification conditions (threshold range) that the increase rate α satisfies to bit "1" respectively, and sets the other bits to bit "0" to generate an identification bit code. Then, it refers to the memory table that has previously stored the correspondence between the detection target in FIG. 6 and the identification bit code, and identifies that it is the detection target corresponding to the matching identification bit code. For example, if the generated bit sequence by the ratio R and the increase rate α is, for example, "100000001", it is identified as "black smoke" corresponding to the matching identification bit code by referring to the memory table.

[0100] Here, for "dust", as shown in FIG. 5, the particle size is distributed in a wide range including other detection targets, and for the ratio R, all identification conditions are satisfied. Therefore, the identification bit code has three types: "10010····0", "01010····0", "00110····0", and if it matches any of them, it is identified as "dust".

[0101] [h. Detection Output Unit] (h1. Output indicating that it is a fire) The detection output unit 22 of the detector 12 will now be explained in more detail. The detection output unit 22 outputs a message indicating a fire to the outside when the identification unit 20 has identified the smoke as fire smoke and the predetermined fire detection conditions are met based on the first detection value A1 detected by the signal detection unit 16. Here, we will explain using the fire detection conditions based on the first detection value A1 as an example, but the same applies to cases based on the second detection value A2 and both.

[0102] Specifically, when the detection output unit 22 identifies the smoke as either black smoke or white smoke, and the predetermined fire detection conditions are met based on the first detection value A1 detected by the signal detection unit 16, it outputs to the outside that it is a black smoke fire or a white smoke fire, and transmits a fire alarm signal to the receiver 10.

[0103] (h2. Suppression of output indicating a fire) Furthermore, when the detection output unit 22 identifies the smoke as not being from a fire and the fire detection condition is met based on the first detection value A1 detected by the signal detection unit 16, it does not output a message indicating a fire to the outside and does not transmit a fire alarm signal to the receiver 10, thereby reliably preventing false fire alarms.

[0104] Specifically, when the detection output unit 22 identifies the substance as mist, steam, cigarette smoke, or dust, and the predetermined fire detection conditions are met based on the first detection value A1 detected by the signal detection unit 16, it will not output a message indicating a fire to the outside and will not transmit a fire alarm signal to the receiver 10.

[0105] Here, if the detection output unit 22 identifies the smoke as non-fire smoke and the fire detection conditions are met, it does not output a message indicating that there is a fire. Instead, it sends a signal to the receiver 10 indicating that non-fire smoke satisfying the fire detection conditions has been detected. The receiver 10's display may then display warning information or environmental information indicating that a level of mist, steam, cigarette smoke, or dust satisfying the fire detection conditions has been detected in the monitoring area.

[0106] (h3. Fire detection conditions) The fire detection conditions for the detection output unit 22 will be explained in more detail. The fire detection conditions for the detection output unit 22 are arbitrary, but as an example, the threshold condition is that the first detection value A1 is equal to or greater than the predetermined smoke concentration threshold Dth or exceeds the threshold Dth. For example, if the detector 12 is a detector of type 2 sensitivity, the threshold condition is that the first detection value A1 is equal to or greater than the smoke concentration threshold Dth = 10 (% / m) corresponding to type 2 sensitivity.

[0107] A "Type 2 sensitivity detector" refers to a detector with a nominal operating concentration K of 10 (% / m) as defined by law. In an operational test, when immersed in an airflow at a wind speed of 20 cm to 40 cm / sec containing smoke with a concentration of (nominal operating concentration K) × 1.5 = 10 (% / m) × 1.5 = 15 (% / m), the detector must activate within 30 seconds. In a non-operation test, when immersed in an airflow at a wind speed of 20 cm to 40 cm / sec containing smoke with a concentration of (nominal operating concentration K) × 0.5 = 10 (% / m) × 0.5 = 5 (% / m), the detector must not activate within 5 minutes, for example, in the case of a non-accumulative type. In addition to such Type 2 sensitivity detectors with K=10 (% / m), a "Type 1 sensitivity detector" with a nominal operating concentration K=5 (% / m) or a "Type 3 sensitivity detector" with a nominal operating sensitivity K=15 (% / m) may also be used.

[0108] Alternatively, another fire detection condition may be an accumulation condition in which the smoke concentration remains above a predetermined threshold Dth for a predetermined time or longer. For example, if the detector 12 is a detector with two levels of sensitivity, the accumulation condition is that the state in which the first detected value A1 is above the smoke concentration threshold Dth = 10 (% / m) corresponding to the two levels of sensitivity continues for a predetermined accumulation time T, for example, T = 20 seconds or more.

[0109] (h4. Transmission of fire alarm signals containing identification information) When the detection output unit 22 outputs to the outside that it is a black smoke fire or a white smoke fire, the sensor control unit 24 instructs the alarm circuit unit 26 to transmit a fire alarm signal containing identification information indicating the type of fire to the receiver 10.

[0110] The transmission of a fire alarm signal by the alarm circuit unit 26 is optional, but for example, the fire alarm signal may be transmitted by short-circuiting the positive signal line 14a and the negative signal line 14b to a predetermined low impedance and flowing a predetermined alarm current for a predetermined time, and then by disconnecting the positive signal line 14a and the negative signal line 14b to a low impedance and flowing a pulse current corresponding to a predetermined code indicating a black smoke fire or a white smoke fire, and this may be repeated periodically. Alternatively, a different alarm current may be set for each black smoke fire or a white smoke fire to transmit the fire alarm signal.

[0111] Furthermore, the detection output unit 22 does not output to the outside that there is a fire when it has been identified as non-fire smoke and the fire detection conditions have been met. However, it may also transmit a signal to the receiver 10 in the same manner as a fire alarm signal that includes identification information indicating that the non-fire smoke satisfies the fire detection conditions, specifically that it is mist, steam, cigarette smoke, or dust.

[0112] [i. Control operation of the sensor] Figure 7 is a flowchart showing the control operation according to the embodiment of the sensor in Figure 2, and represents the control operation of the sensor control unit 24.

[0113] As shown in Figure 7, in step S1, the sensor control unit 24 obtains a first detection value A1 and a second detection value A2 corresponding to the smoke concentration from the first signal and second signal detected and transmitted by the signal detection unit 16. For example, taking the smoke detection unit 31 in Figure 3(A) as an example, the light emission drive unit 36 ​​sequentially drives the first light-emitting element 30 and the second light-emitting element 32 to emit light at predetermined intervals, and scattered light with different wavelengths and scattering angles, such as fire smoke and non-fire smoke, is received by the light-receiving element 34. The first signal and the second signal, amplified by the light-receiving amplification unit 38, are read by A / D conversion in synchronization with each light emission to obtain a first detection value A1 and a second detection value A2 corresponding to the smoke concentration.

[0114] Next, in step S2, the ratio R = A1 / A2 of the first detected value A1 and the second detected value A2 is calculated, and in step S3, for example, the increase rate α of the first detected value A1 is detected. Subsequently, in step S4, if it is determined that the ratio R and the increase rate α satisfy the predetermined black smoke identification conditions, in step S5 the detected object is identified as black smoke. If the black smoke identification conditions are not satisfied in step S4, the process proceeds to step S6, and if the predetermined white smoke identification conditions are satisfied, the process proceeds to step S7 and the object is identified as white smoke.

[0115] If black smoke is identified in step S5, or white smoke is identified in step S7, the process proceeds to step S8. For example, if the first detected value A1 is greater than or equal to the threshold Dth = 10 (% / m) and the fire detection condition is met, the process proceeds to step S9. As an output to the outside indicating that there is a fire, the alarm circuit unit 26 is instructed to send a fire alarm signal containing identification information of black smoke fire or white smoke fire to the receiver 10. Subsequently, in step S10, the receiver 10 determines whether the system has been restored based on the interruption of the power supply to the signal line 14 due to the restoration operation, and the process returns to the initial sensor control in step S1.

[0116] On the other hand, if the ratio R and the increase rate α in step S6 do not satisfy the white smoke identification conditions, the process proceeds to step S11. If the predetermined mist-like substance identification conditions are satisfied, the process proceeds to step S12, where it is determined to be a mist-like substance. Also, if the mist-like substance identification conditions are not satisfied in step S11, the process proceeds to step S13. If the predetermined steam identification conditions are satisfied, the process proceeds to step S14, where it is determined to be steam. Also, if the steam identification conditions are not satisfied in step S13, the process proceeds to step S15. If the predetermined cigarette smoke identification conditions are satisfied, the process proceeds to step S16, where it is determined to be cigarette smoke. Furthermore, if the cigarette smoke identification conditions are not satisfied in step S15, the process proceeds to step S17. If the predetermined dust identification conditions are satisfied, the process proceeds to step S18, where it is determined to be dust.

[0117] If the substance is identified as mist, steam, cigarette smoke, or dust in step S12, S14, S16, or S18, the system proceeds to step S19. For example, if the first detected value A1 is greater than or equal to the threshold Dth = 10 (% / m) and the fire detection condition is met, the system proceeds to step S20. In this step, no output indicating a fire is sent to the outside is given, and the system does not instruct the alarm circuit unit 26 to send a fire alarm signal, returning to the initial sensor control in step S1. In step S20, a signal containing identification information for mist, steam, cigarette smoke, or dust may be sent to the receiver 10 in the same manner as the fire alarm signal.

[0118] [j. Other basic concepts of implementation] Figure 8 is an explanatory diagram showing another basic concept of an embodiment corresponding to the second fire prevention equipment, in which the second fire prevention equipment is equipped with a receiver 10 and a detector 12 connected by a transmission line 114, the detector 12 is provided with a signal detection unit 16 for the fire detection device, and the receiver 10 is provided with a fire detection device increase / decrease rate detection unit 18, an identification unit 20, and a detection output unit 22.

[0119] The signal detection unit 16 provided in the detector 12 and the increase / decrease rate detection unit 18, identification unit 20, and detection output unit 22 provided in the receiver 10 are basically the same as the signal detection unit 16, increase / decrease rate detection unit 18, identification unit 20, and detection output unit 22 provided in the detector 12 in Figure 1. The difference is that the first detection value A1 and the second detection value A2 obtained from the first signal and second signal output from the signal detection unit 16 of the detector 12 are transmitted to the receiver 10 via the transmission line 114, and the receiver 10 does not output to the outside, for example, the increase rate α of the first detection value A1, the identification of whether it is fire smoke or non-fire smoke based on the ratio R of the first detection value A1 and the second detection value A2 and the increase rate α of the first detection value A1, the output indicating that it is a fire when the fire detection conditions are met while it is identified as fire smoke, and the output indicating that it is a fire when the fire detection conditions are met while it is identified as non-fire smoke.

[0120] Next, we will explain in more detail the specific contents of the embodiment corresponding to Figure 8.

[0121] [kR-type disaster prevention equipment] Figure 9 is an explanatory diagram of an R-type (Record-type) fire prevention system, showing the specific details of an embodiment corresponding to Figure 8. Here, an "R-type fire prevention system" is a system that monitors fires for each detector 12 (detector unit) by transmitting data between the receiver 10 and the detectors 12.

[0122] As shown in Figure 9, the R-type disaster prevention equipment of this embodiment includes a receiver 10 and sensors 12, with multiple sensors 12 connected to a transmission line 114 that extends from the receiver 10 to a monitoring area such as a room in a building. The transmission line 114 extending from the receiver 10 includes a positive transmission line 114a and a negative transmission line (common transmission line) 114b, supplying power from the receiver 10 to the sensors 12 and transmitting and receiving signals between the receiver 10 and the sensors 12 using a predetermined transmission method. A dedicated power supply line may also be provided.

[0123] (k1.sensor) Similar to the embodiment in Figure 2, the detector 12 includes a signal detection unit 16 having the first smoke detection structure shown in Figure 3(A), a detector control unit 24, a power supply unit 28, a light emission drive unit 36, and a light receiving amplifier unit 38. However, it differs in that it includes a transmission unit 60 for transmitting and receiving signals to and from the receiver 10 using a predetermined transmission method. Furthermore, the detector control unit 24 does not have the functions of the increase / decrease rate detection unit 18, identification unit 20, and detection output unit 22, which are components of the fire detection device of the present invention shown in Figure 2; these are provided on the receiver 10 side.

[0124] (k2. Receiver) The receiver 10, like the embodiment in Figure 2, includes a receiver control unit 40, a display unit 44, an operation unit 46, an alarm unit 48, and a transmission unit 50. However, it differs in that it includes a transmission unit 62 for sending and receiving signals to and from the detector 12 using a predetermined transmission method. Furthermore, the receiver control unit 40 is equipped with functions that are realized by program execution, namely the increase / decrease rate detection unit 18, the identification unit 20, and the detection output unit 22, which are components of the fire detection device of the present invention. The increase / decrease rate detection unit 18, the identification unit 20, and the detection output unit 22 provided in the receiver 10 are basically the same as those provided in the detector 12 in the embodiment in Figure 2.

[0125] (k3. Transmission control) In the R-type disaster prevention system, each detector 12 is assigned a unique address, and the receiver 10 transmits a batch A / D conversion command signal at a predetermined interval, for example, every minute. All detectors 12 that receive the batch A / D conversion command signal receive scattered light at different wavelengths and scattering angles in the signal detection unit 16 and convert the first detection value A1 and the second detection value A2 based on the detected first and second signals using A / D conversion, and then store (store) them. Subsequently, the receiver 10 performs polling by transmitting call signals that sequentially specify the detector addresses, causing each detector 12 to transmit a response signal containing the first detection value A1 and the second detection value A2.

[0126] When the detector 12 detects a fire precursor (preliminary fire detection level) when the first detection value A1 or second detection value A2 corresponding to the smoke concentration reaches a predetermined fire precursor level, it transmits a fire interruption signal to the receiver 10. Here, the fire precursor level is arbitrary as long as it is smaller than the smoke concentration threshold for identifying a fire, for example, the concentration threshold 5 (% / m) corresponding to a certain sensitivity, for example, a predetermined value in the range of 1 to 3 (% / m), for example, 1 (% / m) is set as the fire precursor level.

[0127] Upon receiving a fire interrupt signal from detector 12, receiver 10 sends a group search command signal specifying a group address, performs a group search to identify the group address to which detector 12 that responded with a fire interrupt signal belongs, and then sends group search command signals sequentially specifying the addresses of detectors within the searched group address, thereby identifying the addresses of detectors 12 that responded with a fire interrupt signal, i.e., the addresses of detectors 12 that detected a fire precursor.

[0128] Next, the receiver 10 transmits an A / D conversion command signal and a call signal specifying the address of the detector 12 that has detected a fire precursor at a predetermined period shorter than normal. The receiver 10 centrally acquires the first detection value A1 and the second detection value A2 from the detector 12 that has detected a fire precursor, and the receiver control unit 40 performs fire detection control using the increase / decrease rate detection unit 18, identification unit 20, and detection output unit 22. Note that the transmission control between the receiver 10 and the detector 12 is just one example, and any known transmission control can be applied.

[0129] (Control operation of k4.R-type disaster prevention equipment) Figure 10 is a flowchart showing the control operation of the R-type disaster prevention equipment embodiment in Figure 9 in a time chart format.

[0130] As shown in Figure 10, in step S21, the receiver 10 performs fire monitoring transmission processing by sending a batch A / D conversion command signal at a predetermined interval, for example, a 1-minute interval, followed by a call signal specifying the detector address, and receives a response signal from the detector 12. Meanwhile, in step S22, the detector 12 performs fire monitoring response processing by receiving the batch A / D conversion command signal from the receiver 10 and storing (memorizing) the first detection value A1 and the second detection value A2 obtained at that time, and then, upon receiving a call signal specifying its own address, transmits a response signal including the first detection value A1 and the second detection value A2.

[0131] Next, when the detector 12 determines in step S23 that the smoke concentration corresponding to the acquired first detection value A1 has reached a predetermined fire warning level, for example, 1 (% / m) or higher, it proceeds to step S24 and transmits a fire interrupt signal to the receiver 10 as a fire warning transmission process. In step S25, the receiver 10 performs a fire warning reception process, and based on the reception of the fire interrupt signal from the detector 12, searches for and identifies the address of the detector that transmitted the fire interrupt signal.

[0132] In step S26, the receiver 10 determines whether a fire interrupt signal has been received from the detector 12. If no fire interrupt signal has been received, it returns to step S21. If a fire interrupt signal has been received, it proceeds to step S27. On the other hand, if a fire interrupt signal has been transmitted, it proceeds to step S27.

[0133] In step S27, the receiver 10 repeatedly sends a batch A / D conversion command signal and a call signal specifying the address of the detector 12 that sent the fire interrupt signal as part of the detection value A1,A2 reception process, causing the detector 12 to send the first detection value A1 and the second detection value A2 in step S28 as part of the detection value A1,A2 transmission process, and the receiver 10 centrally receives the first detection value A1 and the second detection value A2 from the detector 12 that has detected a fire precursor.

[0134] Next, the receiver 10 proceeds to step S29, where it calculates a ratio R = A1 / A2 based on the acquired first detection value A1 and second detection value A2, and detects, for example, the increase rate α of the first detection value A1 using the increase / decrease rate detection unit 18. Subsequently, in step S30, the identification unit 20 identifies whether the smoke is black smoke or white smoke, which are fire smoke, and whether it is non-fire smoke, such as mist, steam, cigarette smoke, or dust, based on the ratio R and the increase rate α. This identification of fire or non-fire smoke is the same as the process using the identification table shown in Figure 6.

[0135] Next, the receiver 10 proceeds to step S31, and if the first detected value A1 satisfies the predetermined fire detection conditions, it proceeds to step S32, and if it identifies the smoke as black smoke or white smoke indicating a fire, it proceeds to step S33 and performs fire alarm processing. This fire alarm processing includes sounding of the main sound alarm and area sound alarm, displaying the location of the fire based on the address of the detector that detected the fire, and interlocking control of smoke control equipment, in addition to displaying on the display that it is an identified black smoke fire or white smoke fire, enabling countermeasures such as evacuation and firefighting in accordance with the characteristics of the fire.

[0136] Next, in step S34, when the receiver 10 determines that the system has been restored due to the recovery operation following the extinguishing of the fire, it sends a recovery signal to the detector 12 in step S35 and returns to the fire monitoring transmission process in step S21. Also, when the detector 12 determines that it has received the recovery signal in step S36, it returns to the fire monitoring response process in step S22.

[0137] On the other hand, if the substance is not identified as fire smoke in step S32, that is, if it is identified as a misty substance, steam, cigarette smoke, or dust that is not fire smoke, the process returns to the fire monitoring transmission process in step S21 without performing the fire alarm processing in step S33, thereby reliably preventing false fire alarms. If the substance is not identified as fire smoke in step S32, the system may output a message indicating that a misty substance, steam, cigarette smoke, or dust that is not fire smoke has been detected at a level that satisfies the fire detection conditions, and display this as cautionary information or environmental information for the monitoring area on the display.

[0138] [l. Modifications of the present invention] A modified embodiment of the present invention will be described in more detail.

[0139] (non-fire smoke) The above embodiments take examples of non-fire smoke such as sprayed mist, steam, cigarette smoke, and dust, but are not limited to these, and include any detection target other than fire that involves light activity occurring in the monitoring area.

[0140] (fire alarm) The above embodiment uses as an example a fire detection device configuration for fire prevention equipment equipped with a receiver and a detector, but a fire alarm for residential use, for example, which is equipped with means for detecting a fire from smoke density and means for sounding out a fire, may also be configured as a fire detection device. In the case of a fire alarm, similar to the detector 12 of the fire prevention equipment shown in Figures 1 and 2, the fire alarm will be equipped with the functions of a signal detection unit 16, an increase / decrease rate detection unit 18, an identification unit 20, and a detection output unit 22 that constitute a fire detection device.

[0141] (others) Furthermore, the present invention includes appropriate modifications that do not impair its purpose and advantages, and is not limited by the numerical values ​​shown in the above embodiments. [Explanation of symbols]

[0142] 10: Receiver 12: Sensor 14: Signal line 16: Signal detection unit 18: Increase / decrease rate detection unit 20: Identification section 22: Detection output unit 24: Sensor Control Unit 26: Alarm circuit section 28: Power supply section 30: First light-emitting element 31: Smoke Detection Department 32: Second light-emitting element 34: Photodetector 34(34-1): First photodetector 34(34-2): Second photodetector 35: Light-emitting element 36: Light-emitting drive unit 38: Light receiving and amplification section 40: Receiver Control Unit 42: Line receiving unit 44: Display section 46:Operation unit 48:Alarm section 50:Transfer Department 60, 62: Transmission section 114: Transmission line

Claims

1. A fire prevention system comprising a receiver and a detector that detects a target object by light and detects a fire, The aforementioned detector is, A signal detection unit detects a first signal obtained by irradiating the target to be detected with light to generate scattered light, receiving scattered light of a first wavelength at a first scattering angle, and a second signal obtained by receiving scattered light of a second wavelength different from the first wavelength at a second scattering angle different from the first scattering angle. An identification unit identifies whether the detected object is fire smoke or non-fire smoke based on the detected values ​​of the first and second signals detected by the signal detection unit and the increasing / decreasing trend of the detected value of at least one of the signals, and identifies whether the non-fire smoke is a mist, steam, cigarette smoke, or dust according to the respective increasing / decreasing trend and inherent particle size, A detection output unit outputs to the outside that if the detected object identified by the identification unit is fire smoke, it is a fire, and if the detected object is identified as non-fire smoke and predetermined fire detection conditions are met based on the detected value of the detected object, it outputs to the outside that non-fire smoke satisfying the fire detection conditions has been detected. Equipped with, The fire prevention equipment is characterized in that the receiver receives a notification that non-fire smoke satisfying the fire detection conditions has been detected and displays warning information or environmental information indicating that mist, steam, cigarette smoke, or dust has been detected.

2. A fire prevention system equipped with a receiver and a detector for detecting fires in a monitored area, The aforementioned detector is, A signal detection unit detects a first signal obtained by irradiating the target to be detected in the monitoring area, which is subject to optical action, with light to generate scattered light, receiving scattered light of a first wavelength at a first scattering angle, and a second signal obtained by receiving scattered light of a second wavelength different from the first wavelength at a second scattering angle different from the first scattering angle. An increase / decrease trend detection unit for detecting the increase / decrease trend of at least one of the first signal and the second signal, An identification unit identifies whether the detected object is fire smoke or non-fire smoke based on the first and second signals detected by the signal detection unit and the increase / decrease trend detected by the increase / decrease trend detection unit, and identifies whether the non-fire smoke is a mist, steam, cigarette smoke, or dust according to the respective increase / decrease trend and inherent particle size. When the detection target is identified as fire smoke by the identification unit, and a predetermined fire detection condition is met based on at least one of the first signal and the second signal detected by the signal detection unit, the detection output unit outputs to the outside that a fire has occurred, and when the detection target is identified as non-fire smoke and the fire detection condition is met based on at least one of the first signal and the second signal, the detection output unit outputs to the outside that non-fire smoke satisfying the fire detection condition has been detected. Equipped with, The fire prevention equipment is characterized in that the receiver receives a notification that non-fire smoke satisfying the fire detection conditions has been detected and displays warning information or environmental information indicating that mist, steam, cigarette smoke, or dust has been detected.

3. A fire detection method using fire prevention equipment equipped with a receiver and a detector that detects an object by light action, The aforementioned detector, Light is shone onto the object to be detected to generate scattered light, and a first signal obtained by receiving scattered light of a first wavelength at a first scattering angle and a second signal obtained by receiving scattered light of a second wavelength different from the first wavelength at a second scattering angle different from the first scattering angle are detected. Based on the detected values ​​of the first signal and the second signal and the increasing / decreasing trend of the detected value of at least one of the signals, it is determined whether the detected object is fire smoke or non-fire smoke, and according to the increasing / decreasing trend and the specific particle size of each, it is determined whether the non-fire smoke is a mist, steam, cigarette smoke, or dust. If the identified detection target is fire smoke, a message indicating that it is a fire is output to the outside; if the detection target is identified as non-fire smoke and the predetermined fire detection conditions are met based on the detection value of the detection target, a message indicating that non-fire smoke satisfying the fire detection conditions has been detected is output to the outside. A fire detection method characterized in that the receiver receives a notification that non-fire smoke satisfying the fire detection conditions has been detected, and displays warning information or environmental information indicating that mist, steam, cigarette smoke, or dust has been detected.

4. A fire detection method using fire prevention equipment equipped with a receiver and a detector for detecting fires in a monitored area, The signal detection unit of the sensor irradiates the object to be detected in the monitoring area, which is subject to optical action, with light to generate scattered light, and detects a first signal obtained by receiving scattered light of a first wavelength at a first scattering angle and a second signal obtained by receiving scattered light of a second wavelength different from the first wavelength at a second scattering angle different from the first scattering angle. The sensor's increase / decrease trend detection unit detects the increase / decrease trend of at least one of the first signal and the second signal. The identification unit of the detector identifies whether the detected object is fire smoke or non-fire smoke based on the first and second signals detected by the signal detection unit and the increase / decrease trend detected by the increase / decrease trend detection unit, and identifies whether the non-fire smoke is a mist, steam, cigarette smoke, or dust according to the respective increase / decrease trend and unique particle size. The detection output unit of the detector outputs to the outside that there is a fire when the detection target is identified as fire smoke by the identification unit and a predetermined fire detection condition is met based on at least one of the first signal and the second signal detected by the signal detection unit, and outputs to the outside that non-fire smoke satisfying the fire detection condition has been detected when the detection target is identified as non-fire smoke and the fire detection condition is met based on at least one of the first signal and the second signal. A fire detection method characterized in that the receiver receives a notification that non-fire smoke satisfying the fire detection conditions has been detected, and displays warning information or environmental information indicating that mist, steam, cigarette smoke, or dust has been detected.

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