JP7644797B2 - Fire alarm system - Google Patents

Description

The present invention relates to a fire alarm system that monitors fires by connecting a fire detector to a receiver.

Conventionally, in fire alarm systems known as R-type, a fire detector with a transmission function and a unique address is connected to a receiver, and in normal monitoring mode, the detection values of smoke concentration, temperature, etc. are collected and monitored by calling the fire detectors whose detector addresses are specified in sequence. In the event of a fire, a search command is issued from the receiver based on a fire interrupt signal from the fire detector to identify the address of the fire detector that triggered the alarm and collect the detection values. If the detection value exceeds a specified fire alarm threshold, it is determined that there is a fire and a fire alarm is output, and further, linked control is performed for the exhaust system, fire doors, automatic reporting to firefighting authorities, etc.

Furthermore, conventional fire alarm systems use photoelectric smoke detectors to detect smoke from fires, but conventional photoelectric smoke detectors can also give false fire alarms due to smoke from cooking or steam from the bathroom, not just smoke from fires.

In order to prevent false fire alarms caused by factors other than fire, a so-called two-wavelength photoelectric smoke detector has been proposed, which irradiates the smoke detection space with light of two different wavelengths and determines the ratio of the light intensities of the different wavelengths of the light scattered by the smoke to determine the type of smoke, thereby increasing the accuracy of smoke identification and ensuring the prevention of false fire alarms (Patent Document 2).

JP 2007-265353 A JP 2004-325211 A Japanese Patent Application Publication No. 6-314384

When such a conventional two-wavelength photoelectric smoke detector is connected to a receiver to monitor for fires, the receiver can distinguish between white smoke caused by a smoldering fire and black smoke caused by a combustion fire and output a fire alarm, making it possible to respond according to the level of fire danger.

However, if steam from a bathroom or other area flows into a photoelectric smoke detector, it may give an identification result similar to the white smoke caused by a smoldering fire, and there remains the possibility that a non-fire cause such as steam may be judged to be a white smoke fire and a non-fire alarm may be issued.

The present invention aims to provide a fire alarm system that improves the accuracy of fire detection and further prevents false fire alarms.

(Fire alarm system)
The present invention relates to a fire alarm system that monitors and issues an alarm for a fire in a warning area,
A fire detector that detects a fire in the alert area and transmits a fire signal;
A human detection means for detecting the presence or absence of a human in the alert area and transmitting a detection signal;
a fire alarm control unit that controls an alarm operation based on a fire signal from the fire detector and a detection signal from the human detection means;
Equipped with
The fire alarm control unit
When it is determined based on the fire signal and the detection signal that a fire with a low risk and the presence of a person in a warning area are present, a caution alarm is output without outputting a fire alarm;
When it is determined that a fire is of low danger and that no one is present in the warning area based on the fire signal and the detection signal, a fire alarm is output;
When a high-risk fire is determined based on the fire signal, a fire alarm is output regardless of whether or not there is a person in the alert area .

( Non-fire factors )
The fire alarm control unit further includes:
Distinguish non-fire factors based on fire signals,
When the presence of a person in the alert area is determined based on the detection signal after determining that a non-fire factor has occurred, the output of a caution alarm indicating the occurrence of a non-fire factor is suspended;
When it is determined that there is no person in the alert area based on the detection signal after determining that there is a non-fire cause, a warning is outputted to indicate the occurrence of a non-fire cause .

(Fire alarm output according to the level of fire danger)
The fire alarm control unit outputs a different fire alarm in accordance with the determined degree of fire danger.

(White smoke fires and black smoke fires)
A low-risk fire determined by the fire alarm control unit includes a white smoke fire, and a high-risk fire determined by the fire alarm control unit includes a black smoke fire.

(Basic Effects)
The present invention is a fire alarm system that monitors and issues an alarm for fires in a security zone, and is equipped with a fire sensor that detects a fire in the security zone and transmits a fire signal, a person detection means that detects the presence or absence of people in the security zone and transmits a detection signal, and a fire alarm control unit that outputs a caution alarm rather than a fire alarm when it determines that there is a low-risk fire and the presence of people in the security zone based on the fire signal from the fire sensor and the detection signal from the person detection means.Therefore, when there is a high possibility that non-fire factors such as steam from a bathroom, kitchen, etc. have been caused by occupants, the system only issues a caution alarm to alert the occupants rather than outputting a fire alarm, and by notifying the occupants of the caution alarm, it is possible to respond to the fire even if it is a fire and not a non-fire.

(Fire alarm effectiveness)
The fire alarm control unit outputs a fire alarm when it determines that there are no people in the alert area after determining that the fire is a low-risk fire, and when it determines that there is a high-risk fire, making it possible to respond to the fire immediately when there is no one in the room and there is a low possibility of non-fire factors such as steam from the bathroom or kitchen, or when the fire is a high-risk fire.

(Fire alarm output according to the level of fire danger)
The fire alarm control unit outputs different fire alarms according to the determined degree of fire danger, thereby enabling necessary measures to be taken according to the state of the fire.

FIG. 1 is an explanatory diagram showing an embodiment of a fire alarm system combined with an entrance/exit management system. FIG. 2 is an explanatory diagram showing an overview of the entrance/exit management system of FIG. 1. A block diagram showing the circuit configuration of a photoelectric smoke detector installed in the fire alarm system of FIG. FIG. 4 is an explanatory diagram showing an embodiment of the structure of the smoke detector in FIG. FIG. 4 is an explanatory diagram showing smoke detection values and their ratios detected by the smoke detector structure of FIG. 3 for smoke when a cotton wick and kerosene are burned. 2 is a flowchart showing the control operation in the receiver of FIG. 1. A flowchart showing the control operation in the photoelectric smoke detector of FIG. FIG. 1 is an explanatory diagram showing an embodiment of a fire alarm system combined with a human sensor. FIG. 1 is an explanatory diagram showing an embodiment of a fire alarm system combined with a security system.

[Fire alarm system]
(Outline of fire alarm system)
Fig. 1 is an explanatory diagram showing an embodiment of a fire alarm system combined with an entrance/exit management system. As shown in Fig. 1, a receiver 10 of, for example, an R type is installed in a monitoring center or a manager's room of a facility where a fire alarm system 1 is installed, and signal lines 12-1 to 12-3 are drawn from the receiver 10 for each system to the alert area.

Multiple photoelectric smoke detectors 14 with transmission capabilities and unique addresses are connected to the signal line 12-1. The photoelectric smoke detectors 14 are so-called two-wavelength photoelectric smoke detectors that have the function of detecting a first smoke detection value A1 by receiving light with a first wavelength λ1 and scattered light from smoke set at a first scattering angle θ1, and detecting a second smoke detection value A2 by receiving light with a second wavelength λ2 and scattered light from smoke set at a second scattering angle θ2.

Here, in the following explanation, the first smoke detection value A1 and the second smoke detection value A2 may simply be referred to as the smoke detection value A1 and the smoke detection value A2.

In addition to the so-called two-wavelength photoelectric smoke detector 14, ordinary photoelectric smoke detectors and heat detectors with transmission functions are also connected to the signal line 12-1, and on-off type fire detectors and transmitters are connected to the detector line drawn from the repeater with transmission functions, but are not shown in the figure.

Signal lines 12-2 and 12-3 are connected to control devices such as a local sound system 18, an exhaust system 20, and a fire door 22 via a repeater 16 with a transmission function and a unique address set.

The local acoustic device 18 outputs a specific local acoustic alarm to notify the alert area of the occurrence of a fire under the control of the receiver 10. In this embodiment, if the receiver 10 recognizes a white smoke fire, it outputs a local acoustic alarm including a message urging people to check the scene, and if the receiver 10 identifies a black smoke fire, it outputs a local acoustic alarm including a message urging people to evacuate.

The exhaust device 20 is activated by a control command from the receiver 10 to ventilate the alert area. The fire door 22 is latched open by a control command from the receiver 10 and is operated to the closed position, closing off the compartment where the fire has occurred and preventing the fire from spreading.

The maximum number of addresses per line set for terminal devices such as photoelectric smoke detectors 14 and repeaters 16 connected to signal lines 12-1 to 12-3 is, for example, 255, and a maximum of 255 terminal devices can be connected to each of signal lines 12-1 to 12-3.

(Receiver functional configuration)
The receiver 10 is provided with a main CPU 26 and sub-CPU boards 28-1 to 28-3, and each of the sub-CPU boards 28-1 to 28-3 is provided with a sub-CPU 30 and a transmission unit 32. The main CPU 26 and the sub-CPU 30 are connected by a serial transfer bus 34, and transmit and receive data between them.

Connected to the main CPU 26 are a display 36 with a touch panel using a liquid crystal display panel or the like, a display unit 38 equipped with representative lights for fire, gas leaks, and faults, LED indicator lights, etc., an operation unit 40 equipped with various switches necessary for fire monitoring such as a fire determination switch, a district sound stop switch, and a report transfer stop switch, an audio alarm unit 42 equipped with a speaker, and a report transfer unit 44.

Although not shown, emergency broadcast devices and automatic reporting devices are connected to the reporting unit 44 as reporting destinations. The emergency broadcast device operates in response to a reporting signal from the receiver 10, and outputs an emergency broadcast from a speaker installed in the alert area to notify of a fire outbreak and to guide evacuation. When the emergency broadcast device is activated, the local acoustic warning from the local acoustic device 18 is stopped. The automatic reporting device operates in response to a reporting signal from the receiver 10, and makes a 119 call connection via a public telephone line to report the occurrence of a fire.

Furthermore, a communication adapter 45 is connected to the main CPU 26, and the communication adapter 45 transmits and receives signals to and from the entrance/exit management system 100.

(Entrance/Exit Management System)
An entrance/exit management system 100 installed in a facility such as an office building or a factory is composed of a central device 102, a client 104, a local control panel 108, a card reader 110 for entering and exiting the room, and an electronic lock 112.

The central device 102 is installed in a monitoring center, a manager's office, etc., and the client 104 is installed in a general affairs department that handles entrance and exit management. The local control boards 108 are installed, for example, on each floor of a facility. The local control boards 108 are connected to the central device 102 and the client 104 via a LAN line 106.

The card reader 110 is placed on the outside of the door that serves as the entrance and exit for each room, and the door is equipped with an electric lock 112. The card reader 110 and the electric lock 112 are connected to a signal line from a local control panel 108 installed on the same floor.

The card reader 110 reads the specified user identification information recorded on a magnetic card or contactless IC card carried by the user, compares it with pre-registered user identification information, and if the comparison results in a match and authentication is successful, sends an authentication signal to the local control panel 108.

When the local control panel 108 receives an authentication signal from the card reader 110, it transmits the authentication signal to the center device 102 via the LAN line 106, and records the arrival time or departure time in the entry/exit information managed by the center device 102. In addition, when the local control panel 108 receives an authentication signal from the card reader 110, it outputs a control signal to the electric lock 112 installed at the corresponding entrance/exit to unlock it and allow entry/exit.

The center device 102 has the function of displaying management information such as a map of the facility in which the entrance/exit management system 100 is installed, as well as the function of serving as a database for storing and managing entrance/exit information indicating the status of occupants.

The client 104 is connected to the center device 102 and the local control panel 108 via the LAN line 106, and performs various settings and processing such as registering, deleting, and searching history of user identification information corresponding to magnetic cards and contactless IC cards between the client 104 and the card reader 110 via the local control panel 108.

In addition, in this embodiment, a communication adapter 114 is connected to the center device 102, and the communication adapter 114 is connected to a communication adapter 45 provided in the receiver 10 of the fire alarm system 1 shown in FIG. 1, and can transmit an entry/exit management signal indicating the status of people present in the room upon request from the receiver 10.

[Receiver control functions]
As shown in FIG. 1, the main CPU 26 of the receiver 10 is provided with a fire alarm control unit 48 as a function realized by executing a program.

The sub-CPU 30 provided on the sub-CPU boards 28-1 to 28-3 of the receiver 10 is provided with a transmission control unit 46 as a function realized by executing a program. The transmission control unit 46 provided on the sub-CPU 30 of the sub-CPU board 28-1 controls the collection of the first smoke detection value A1 and the second smoke detection value A2 detected by the two-wavelength photoelectric smoke detector 14 connected to the signal line 12-1.

The transmission control units 46 of the sub-CPU boards 28-2 and 38-3 also perform fire interlock control by sending control signals that specify the addresses of the repeaters 16 that connect the control devices, such as the local sound device 18, exhaust device 20, and fire doors 22, that are connected to the respective signal lines 12-2 and 12-3.

(Control of collection of detector detection data)
The transmission control unit 46 provided in the sub-CPU 30 of the sub-CPU board 28-1 controls the collection of detection data by instructing the transmission unit 32 to send and receive signals between the photoelectric smoke detector 14 connected to the signal line 12-1 in accordance with a predetermined communication protocol.

The downstream signal from the transmission unit 32 to the photoelectric smoke detector 14 is transmitted in voltage mode. This voltage mode signal is transmitted as a voltage pulse that changes the line voltage of the signal line 12-1 between, for example, 18 volts and 30 volts.

In contrast, the upstream signal from the photoelectric smoke detector 14 to the transmission unit 32 is transmitted in current mode. In this current mode, a signal current is passed through the signal line 12-1 at the timing of bit 1 of the transmission data, and the upstream signal is transmitted to the receiver 10 as a so-called current pulse train.

During normal monitoring, the data collection control by the transmission control unit 46 of the sub-CPU 30 periodically instructs the transmission unit 32 to transmit a broadcast batch AD conversion signal including a batch AD conversion command, and the photoelectric smoke detector 14 that receives this batch AD conversion signal converts the smoke detection value detection signals of the first smoke detection value A1 and the second smoke detection value A2 output from the smoke detector unit by AD conversion into digital smoke detection value signals and holds them.

Then, the transmission control unit 46 of the sub-CPU 30 transmits a call signal including a polling command that sequentially specifies the terminal addresses. When the photoelectric smoke detector 14 receives a call signal with an address that matches its own address, it transmits a call response signal including the first smoke detection value A1 and the second smoke detection value A2 that it is holding at that time to the receiver 10.

In addition, if the photoelectric smoke detector 14 is equivalent to a type 2 sensitivity smoke detector that alerts a fire at a smoke density of 10%/m, for example, a smoke density threshold equivalent to type 1 sensitivity, for example a smoke density threshold of 5.0%/m, is set as the warning indication threshold AP1th for the first smoke detection value A1 in the photoelectric smoke detector 14, and when the detected first smoke detection value A1 becomes equal to or exceeds the warning indication threshold AP1th, it is determined that a fire has been alerted, and a fire interrupt signal is sent to the receiver 10.

In addition, a smoke density threshold equivalent to Class 1 sensitivity, for example a smoke density threshold of 5.0%/m, may be set as the warning indication threshold AP2th for the second smoke detection value A2 in the photoelectric smoke detector 14, and when the detected second smoke detection value A2 becomes equal to or greater than the warning indication threshold AP2th, it may be determined that a fire has been alerted and a fire interrupt signal may be sent to the receiver 10.

When the transmission control unit 46 of the sub-CPU 30 receives a fire interrupt signal from the photoelectric smoke detector 14 via the transmission unit 32, it transmits a group search command signal to identify the group that includes the photoelectric smoke detector 14 that has triggered the fire, and then transmits an intra-group search command signal to identify the address of the photoelectric smoke detector 14 that has triggered the fire, and intensively collects the first and second smoke detection values A1, A2, and transmits them to the main CPU 26 via the serial transfer bus 34.

The transmission control unit 46 of the sub-CPU 30 collects the first and second smoke detection values A1 and A2 intensively by shortening the transmission period of the batch AD conversion signal, and by transmitting a call signal specifying the address of the photoelectric smoke detector 14 that has issued a fire alarm after transmitting the batch AD conversion signal, the first smoke detection value A1 and the second smoke detection value A1 of the photoelectric smoke detector 14 are continuously collected.

(Fire alarm control)
The fire alarm control unit 48 of the main CPU 26 calculates a ratio R=A1/A2 from the first smoke detection value A1 and the second smoke detection value A2 received from the sub CPU 30, and compares it with a predetermined ratio threshold value Rth to determine a white smoke fire if R≧Rth, and a black smoke fire if R<Rth. Details of how the fire alarm control unit 48 determines whether a white smoke fire or a black smoke fire is determined will be made clear later in the explanation of the photoelectric smoke detector 14.

Then, the fire alarm control unit 48 of the main CPU 26 instructs the communication adapter 45 to establish a communication connection via the communication adapter 114 to the center device 102 of the entry/exit management system 100 shown in FIG. 2, receive the entry/exit management information that indicates the status of occupants managed by the center device 102 at that time, and determine whether or not there are occupants.

Next, if the fire alarm control unit 48 of the main CPU 26 has determined that a white smoke fire has occurred, for example, and the first smoke detection value A1 is equal to or greater than the fire alarm threshold A1th = 10%/m corresponding to the two-level sensitivity setting of the photoelectric smoke detector 14, the fire alarm control unit 48 performs fire alarm control according to the presence or absence of occupants.

When the fire alarm control unit 48 detects a white smoke fire and detects the presence of people in the room, it determines that there is some non-fire factor and performs control to output a caution alarm without outputting a fire alarm.

In addition, when the fire alarm control unit 48 identifies a white smoke fire and determines that no one is present in the room, it determines that the fire is a white smoke fire in which white smoke is slowly increasing due to a smoldering fire, and performs control to output a fire alarm indicating a white smoke fire.

A fire alarm indicating a white smoke fire issued by the fire alarm control unit 48 turns on the fire representative light on the display unit 38, outputs a predetermined main sound alarm indicating a fire from the speaker of the sound alarm unit 42, displays fire alarm information on the display 36 including the location of the fire based on the address of the sensor where the fire was detected and type information indicating a white smoke fire, and further performs predetermined white smoke fire linkage control.

The white smoke fire linkage control by the fire alarm control unit 48 transmits a local acoustic control signal specifying the address of the local acoustic device 18 in the alert area (i.e., the address of the repeater 16 to which the local acoustic device 18 is connected) that corresponds to the address of the photoelectric smoke detector 14 that has triggered a fire, and by activating the local acoustic device 18 specified by the address, a local acoustic alarm including an audio message urging residents and others to check the scene is output, since white smoke fires are fires that generate white smoke due to smoldering fires in the early stages of a fire.

In addition, the white smoke fire linkage control by the fire alarm control unit 48 specifies the address of the exhaust device 20 installed in the alert area corresponding to the address of the photoelectric smoke detector 14 that triggered the fire (i.e., the address of the repeater 16 to which the exhaust device 20 is connected) and sends a control signal, and the exhaust device 20 is activated to exhaust the white smoke generated by the smoldering fire to the outside, thereby providing ventilation.

On the other hand, if the fire alarm control unit 48 of the main CPU 26 has identified, for example, a black smoke fire, it will determine that the rapidly expanding burning fire is generating black smoke and posing a high risk of danger, and will perform control to output a fire alarm indicating a black smoke fire, regardless of whether or not there are people in the room.

A fire alarm indicating a black smoke fire issued by the fire alarm control unit 48 turns on the fire representative light on the display unit 38, outputs a predetermined main sound alarm indicating a fire from the speaker of the sound alarm unit 42, displays fire alarm information on the display 36 including the location of the fire and type information indicating a black smoke fire based on the address of the sensor where the fire was detected, and further performs predetermined black smoke fire linkage control.

The black smoke fire interlocking control by the fire alarm control unit 48 activates the local sound device 18, exhaust device 20, and fire door 22 by sending a control signal specifying the address of the repeater 16 connected to each of the local sound device 18, exhaust device 20, and fire door 22 installed in the alert area corresponding to the address of the photoelectric smoke detector 14 that triggered the fire alarm.

The local sound device 18 activates based on the identification of a black smoke fire to issue a local sound warning that includes a voice message encouraging residents to evacuate, since black smoke fires are highly dangerous because black smoke fires generate black smoke due to combustion. In addition, the exhaust device 20 is activated based on the identification of a black smoke fire to ventilate the compartment where the fire started, and the closing activation of the fire door 22 closes the compartment where the fire started to prevent the fire from spreading.

Furthermore, as black smoke fire interlocking control by the fire alarm control unit 48, it instructs the notification transfer unit 44 to output a notification transfer signal to an emergency broadcast device or automatic reporting device (not shown) to perform interlocking control. The emergency broadcast device is activated by a notification transfer signal from the receiver 10, and issues an emergency broadcast from a speaker installed in the alert area notifying the occurrence of a fire and including an audio message encouraging evacuation. At this time, the fire alarm control unit 48 sends a stop signal to the local sound device 18 to stop outputting the local sound alarm, ensuring that the emergency broadcast can be heard.

The automatic reporting device is activated by a signal from the receiver 10, and automatically reports the occurrence of a fire to a firefighting agency by calling 119 over the public telephone line, requesting extinguishing of the fire.

[Photoelectric smoke detector]
(Circuit configuration)
Fig. 3 is a block diagram showing the circuit configuration of a photoelectric smoke detector provided in the fire alarm system of Fig. 1. As shown in Fig. 3, the photoelectric smoke detector 14 of this embodiment is composed of a detector control unit 50 composed of a computer circuit equipped with a CPU, memory, and various input/output ports, a transmission unit 52 that transmits and receives signals to and from the receiver 10 via a signal line 12 connected to an S terminal and an SC terminal, a power supply unit 54 that converts a power supply voltage supplied via the signal line 12 into a predetermined stabilized voltage and outputs it, a light emission drive unit 56, a smoke detection unit 60, and amplifier circuit units 68, 70.

The smoke detector 60 is provided with a light-emitting element 62 that simultaneously emits light including a first wavelength λ1 and a second wavelength λ2. The light of the first wavelength λ1 emitted from the light-emitting element 62 has a central wavelength set to 600 nm or more, and the light of the second wavelength λ2 has a central wavelength set to 500 nm or less. In this embodiment, the first wavelength λ1 is set to, for example, 700 nm, and the second wavelength λ2 is set to, for example, 450 nm.

In this embodiment, a white LED (white light emitting diode) is used as the light emitting element 62. The white LED is, for example, a combination of a blue LED and a phosphor, and the light of the blue LED passes through the phosphor to emit white light. This emitted light color includes light with a first wavelength λ1 = 700 nm and light with a second wavelength λ2 = 450 nm, and the light of the first wavelength λ1 and the light of the second wavelength λ2 can be simultaneously irradiated into the smoke detection unit 60.

In addition, a two-color LED (two-color light-emitting diode) can be used as the light-emitting element 62 in this embodiment. The two-color LED has a first light-emitting chip that emits light with a first wavelength λ1 = 700 nm and a second light-emitting chip that emits light with a second wavelength λ2 = 450 nm, and by driving both at the same time, light with the first wavelength λ1 and the second wavelength λ2 can be irradiated simultaneously into the smoke detection unit 60.

The first light receiving element 64 uses a photodiode (PD) sensitive to the first wavelength λ1, and the second light receiving element 66 uses a photodiode (PD) sensitive to the second wavelength λ2.

The first light receiving element 64 and the second light receiving element 66 may be a wideband photodiode sensitive to the visible light wavelength band, with a filter layer provided in the PD molding (transparent cover member) that receives only the wavelength bands of the first wavelength λ1 and the second wavelength λ2, or a filter that transmits the wavelength bands of the first wavelength λ1 and the second wavelength λ2 may be disposed in front of the wideband photodiode.

The amplifier circuit unit 68 amplifies the received light signal of the smoke scattered light of the first wavelength λ1 received by the first light receiving element 64, and outputs the received light signal to the sensor control unit 50 as the first smoke detection value A1. The amplifier circuit unit 70 amplifies the received light signal of the smoke scattered light received by the second light receiving element 66, and outputs the received light signal to the sensor control unit 50 as the second smoke detection value A2.

(Smoke Detection Department)
Fig. 4 is an explanatory diagram showing an embodiment of the structure of the smoke detector in Fig. 3. As shown in Fig. 4, a light emitting element 62, a first light receiving element 64 and a second light receiving element 66 are arranged in a smoke detector 60 into which smoke from the outside flows.

For example, the light-emitting element 62 using a white LED emits light including a first wavelength λ1 and a second wavelength λ2 in the direction of the optical axis 62a, and as described above, the light of the first wavelength λ1 is set to 700 nm, and the light of the second wavelength λ2 is set to 450 nm.

The first scattering angle θ1 formed by the intersection of the optical axis 62a of the light-emitting element 62 and the optical axis 64a of the first light-receiving element 64 is set in the range of 20° to 70°, and the optical axis 62a of the light-emitting element 62 and the optical axis 64a of the first light-receiving element 64 are arranged to intersect at a predetermined angle in the range of 110° to 160°.

The second scattering angle θ2 formed by the intersection of the optical axis 62a of the light-emitting element 62 and the optical axis 66a of the second light-receiving element 66 is set to a range of 110° to 150°, and the light-emitting element 62 and the optical axis 66a of the second light-receiving element 66 are arranged so that they intersect at a predetermined angle in the range of 30° to 70°.

In this embodiment, the first scattering angle θ1 is set to 30°, so the optical axis 62a of the light-emitting element 62 and the optical axis 64a of the first light-receiving element 64 are arranged to intersect at a crossing angle of, for example, 150°, and the second scattering angle θ2 is set to 120°, so the optical axis 62a of the light-emitting element 62 and the optical axis 66a of the second light-receiving element 66 are arranged to intersect at a crossing angle of, for example, 60°.

The first light receiving element 64 is sensitive to the light of the first wavelength λ1 = 700 nm emitted from the light emitting element 62. Therefore, when the light emitting element 62 emits light of the first wavelength λ1, the scattered light with a scattering angle θ1 = 30° caused by the smoke that has flowed into the smoke detector 60 is received by the first light receiving element 64, and a first smoke detection value A1 is obtained.

In addition, since the second light receiving element 66 is sensitive to the light of the second wavelength λ2 = 450 nm emitted from the light emitting element 62, when the light emitting element 62 emits light of the second wavelength λ2 simultaneously with the light of the first wavelength λ1, the scattered light at the second scattering angle θ2 = 120° caused by the smoke that has flowed into the smoke detection unit 60 is received by the second light receiving element 66, and a second smoke detection value A2 is obtained at the same time.

When the sensor control unit 50 shown in FIG. 3 receives a batch AD conversion signal from the receiver 10 via the transmission unit 52, it instructs the light emission drive unit 56 to drive the light emitting element 62 to emit white light including the first wavelength λ1 and the second wavelength λ2, and the forward scattered light with the first scattering angle θ1 = 30° due to the first wavelength λ1 is received by the first light receiving element 64. In response to this, the first smoke detection value A1 output from the amplifier circuit unit 68 is AD converted to digital data, read, and stored in memory.

At the same time, the backscattered light with the second wavelength λ2 and the second scattering angle θ2 = 120° is received by the second light receiving element 66, so the sensor control unit 50 converts the second smoke detection value A2 output from the amplifier circuit unit 70 in response to the light received by the second light receiving element 66 into digital data, reads it, and stores it in memory.

The detector control unit 50 then compares the first smoke detection value A1 stored in memory with a warning indication threshold AP1th that is predefined in accordance with the sensitivity setting of the photoelectric smoke detector 14, and if the first smoke detection value A1 is equal to or greater than the warning indication threshold AP1th, determines that a fire has been alerted, and instructs the transmission unit 52 to transmit a fire interrupt signal to the receiver 10.

As described above, when the photoelectric smoke detector 14 is equivalent to a type 2 sensitivity with a fire alarm threshold A1th of 10%/m, the warning indication threshold AP1th is set to, for example, AP1th = 5%/m, which is equivalent to a type 1 sensitivity. Also, when the photoelectric smoke detector 14 is equivalent to a type 3 sensitivity with a fire alarm threshold A1th of 15%/m, the warning indication threshold AP1th is set to, for example, APth = 10%/m, which is equivalent to a type 2 sensitivity.

(Distinguishing between white and black smoke fires)
FIG. 5 is an explanatory diagram showing smoke detection values and their ratios detected by the smoke detector structure of FIG. 4 for smoke when a cotton wick and kerosene are burned.

As shown in FIG. 5, the first smoke detection value A1 is the received output of scattered light with a first wavelength λ1 = 700 nm and a first scattering angle θ1 = 30°, and the second smoke detection value A2 is the received output of scattered light with a second wavelength λ2 = 450 nm and a second scattering angle θ2 = 120°.

If we take the ratio R = A1/A2 of the first and second smoke detection values A1, A2 measured when burning such a cotton wick and kerosene, then in the case of cotton wick, R = 8.0, and in the case of kerosene, R = 2.3. This shows a significant difference in the ratio R between cotton wick and kerosene, making it possible to identify the type of smoke based on the ratio R.

For this reason, the ratio threshold value Rth for identifying the type of smoke can be set to, for example, Rth = 5, and if R ≥ 5, it can be determined to be a white smoke fire where white smoke is generated by smoldering, and if R < 5, it can be determined to be a black smoke fire where black smoke is generated by combustion.

In this embodiment, the receiver 10 shown in FIG. 1 collects the first and second smoke detection values A1, A2 detected by the photoelectric smoke detector 14 that has triggered a fire alarm, and the fire alarm control unit 48 calculates the ratio R = A1/A2 of the first and second smoke detection values A1, A2, and if R ≥ 5, determines that the fire is a white smoke fire where white smoke is being generated by smoldering, and if R < 5, determines that the fire is a black smoke fire where black smoke is being generated by combustion.

In addition, when the fire alarm control unit 48 of the receiver 10 determines that a white smoke fire has occurred based on the first and second smoke detection values A1 and A2, if the first smoke detection value A1 is equal to or greater than the fire alarm threshold A1th corresponding to a smoke concentration of 10%/m for the second sensitivity level, it determines that a fire has occurred and performs control to output a fire alarm including information indicating a white smoke fire.

Similarly, when the fire alarm control unit 48 of the receiver 10 determines that a black smoke fire has occurred based on the first and second smoke detection values A1 and A2, if the second smoke detection value A2 is equal to or greater than the fire alarm threshold A2th corresponding to a smoke concentration of 10%/m for the second sensitivity level, it determines that a fire has occurred and performs control to output a fire alarm including information indicating a black smoke fire.

(Identification of non-fire factors)
When a non-fire cause, such as steam from a bathroom, flows into the smoke detection unit 60 of the photoelectric smoke detector 14 shown in FIG. 4, the ratio R of the first and second smoke detection values A1, A2 will be a large value, for example exceeding R=10.

For this reason, the non-fire cause threshold value RSth for identifying steam is set to, for example, RSth = 12, and if R ≥ 12, it is identified as a non-fire cause such as steam.

The fire alarm control unit 48 of the receiver 10 also judges whether a non-fire factor has occurred based on the ratio R of the first and second smoke detection values A1 and A2, and if R≧12, it judges that a non-fire factor such as steam has occurred, and performs alarm control based on the entry/exit detection signal obtained from the entry/exit management system 100.

That is, the fire alarm control unit 48 determines whether a non-fire factor exists based on the ratio R of the smoke detection values A1 and A2, and when it determines that someone is present based on the entry/exit detection signal, it refrains from outputting a warning alarm indicating a non-fire factor, whereas when it determines that a non-fire factor exists and that no one is present, it outputs a warning alarm indicating a non-fire factor.

For this reason, if there is someone in the room when a non-fire alarm is determined to be due to steam or cooking smoke from a bathroom, etc., then a warning alarm is deemed unnecessary and will be withheld, as the steam or cooking smoke is due to the person using the bathroom. On the other hand, if there is no one in the room when a non-fire cause is determined, then a warning alarm will be issued, allowing the necessary response to be taken, as the steam or cooking smoke from the bathroom, etc. has been left unattended.

Furthermore, in this embodiment, a sensor is provided as a human detection means for detecting the operation of switches on appliances such as home appliances, water heaters, and lighting in the security zone, and when this sensor detects the operation of a switch on an appliance, it transmits a presence detection signal to the receiver indicating the presence or absence of a human.

For this reason, the fire alarm control unit 48 uses a human presence sensor to detect the operation of the switches for the water heater and lights in the bathroom, cooking appliances such as a gas range, and home appliances such as the television and air conditioner. Since it is believed that people are present in the room when these are operating and there is a possibility of a non-fire event occurring, the fire alarm control unit 48 determines whether a non-fire event has occurred based on the ratio R of the smoke detection values A1 and A2, and holds off on issuing a warning alert indicating a non-fire event in the receiver, while simultaneously outputting a warning alert indicating a non-fire event on the information display device (not shown) for that room.

[Fire monitoring and control of fire alarm equipment]
Fig. 6 is a flow chart showing the control operation in the receiver of Fig. 1, which is the control operation by the transmission control section 46 and the fire alarm control section 48 shown in Fig. 1. Also, Fig. 7 is a flow chart showing the control operation in a photoelectric smoke detector, which is the control operation by the detector control section 50. Furthermore, the control in Fig. 6 and Fig. 7 is characterized in that the receiver 10 side distinguishes between a white smoke fire, a black smoke fire, and a non-fire cause.

(Receiver control)
As shown in FIG. 6, in step S1, the transmission control unit 46 of the receiver 10 transmits a broadcast batch AD conversion signal designating all photoelectric smoke detectors 14 to the signal line 12-1 at a predetermined period, AD converts the smoke detection values A1, A2, which are analog signals detected on the photoelectric smoke detector 14 side, into digital signals and stores them, then transmits a call signal designating the addresses of the photoelectric smoke detectors 14 in sequence, receives call response signals transmitted by the photoelectric smoke detectors 14 that received the call signal, and performs call response control to monitor the status of the photoelectric smoke detectors 14 to see if they are operating normally.

Next, when the transmission control unit 46 determines in step S2 that it has received a fire interrupt signal from the photoelectric smoke detector 14 that has triggered a fire, it proceeds to step S3, where it searches for the address of the photoelectric smoke detector 14 that has triggered a fire and sent the fire interrupt signal by transmitting a group search command signal and an intra-group search command signal.

Then, the transmission control unit 46 proceeds to step S4, shortens the period of the batch AD conversion signal, and by transmitting a call signal specifying the address of the photoelectric smoke detector 14 that transmitted the fire interrupt signal, repeatedly acquires the first and second smoke detection values A1, A2 from the photoelectric smoke detector 14 that has generated the fire alarm, and transmits them to the fire alarm control unit 48 of the main CPU 26.

In step S5, the fire alarm control unit 48 calculates the ratio R = A1/A2 of the first and second smoke detection values A1, A2, and in step S6 compares it with a ratio threshold value Rth = 5 preset based on FIG. 5. If R ≥ 5, the process proceeds to step S7 to determine that the fire is a white smoke fire, and if R < 5, the process proceeds to step S12 to determine that the fire is a black smoke fire. Note that if the ratio R is equal to or greater than the non-fire cause threshold value RSth = 12, the fire alarm control unit 48 determines that the fire is a non-fire cause due to steam, but this is not shown in the figure.

Next, if the fire alarm control unit 48 determines in step S6 that the ratio R is equal to or greater than the ratio threshold value Rth = 5, it proceeds to step S8, acquires occupancy information from the entry/exit management system 100, and if it determines in step S9 that someone is present, it determines that there is some non-fire factor due to the presence of a person, outputs a caution alarm without outputting a fire alarm, and repeats the monitoring process from step S1.

On the other hand, if the fire control unit 48 determines in step S9 that no one is present, it proceeds to step S10. If it determines that the first smoke detection value A1 is equal to or greater than the fire alarm threshold A1th, it determines that a fire has been confirmed and proceeds to step S11. Since a white smoke fire has been identified and it has been determined that no one is present, it outputs a fire alarm indicating a white smoke fire and performs linked control corresponding to a white smoke fire.

On the other hand, if the fire alarm control unit 48 determines in step S6 that the ratio R is less than the ratio threshold Rth = 5, it proceeds to step S12 to determine that it is a black smoke fire, and then proceeds to step S13. If it determines that the second smoke detection value A2 is equal to or greater than the fire alarm threshold A2th, it determines that a fire has been confirmed and proceeds to step S14. Since a black smoke fire has been determined, a fire alarm indicating a black smoke fire is output regardless of whether or not there is an occupant in the room, and linked control corresponding to a black smoke fire is performed.

Then, the fire alarm control unit 48 repeats the process from step S1 until it is determined in step S15 that the fire has been restored. If it is determined that the fire has been restored, it sends a fire restoration signal to the photoelectric smoke detector 14 in step S16 to restore the detector, and then returns to step S1, and repeats the control from step S1.

(Photoelectric smoke detector control)
As shown in Figure 7, when the detector control unit 50 of the photoelectric smoke detector 14 shown in Figure 2 determines in step S21 that it has received a batch AD converted signal from the receiver 10, it proceeds to step S22, and detects a smoke detection value A1 detected by receiving light of the first wavelength λ1 and scattered light at the first scattering angle θ1, and a smoke detection value A2 detected by receiving light of the second wavelength λ2 and scattered light at the second scattering angle θ2, by driving the light-emitting element 62 to emit light, and stores these in memory in step S23.

Next, when the detector control unit 50 determines in step S24 that it has received a call signal specifying its own address, it proceeds to step S25 and transmits a call response signal indicating the detector status, thereby informing the receiver 10 of its own status.

Then, the detector control unit 50 proceeds to step S26, and if it determines that the first smoke detection value A1 is equal to or greater than the warning indication threshold AP1th = 5%/m corresponding to the second sensitivity level, a fire is alerted, and proceeds to step S27 to send a fire interrupt signal to the receiver 10. If it determines in step S28 that a group search command and an intra-group search command have been received from the receiver 10, it proceeds to step S29 to send a search response signal indicating a fire alert, thereby causing the receiver 10 to obtain the address of the photoelectric smoke detector 14 that alerted the fire.

Then, since the receiver 10 transmits a batch AD conversion signal followed by a call signal specifying the fire alert address at short intervals, the detector control unit 50 determines in step S30 that the batch AD conversion signal and the call signal have been received and proceeds to step S31, where the light emitting element 62 is driven to emit light to detect the first and second smoke detection values A1, A2 and store them in memory, and in step S32 transmits a call response signal including the smoke detection values A1, A2 to the receiver 10, which determines the ratio R of the smoke detection values A1, A2, identifies whether the fire is a white smoke fire or a black smoke fire, and controls the fire alarm based on the presence or absence of occupants.

Then, the detector control unit 50 repeats the process from step S30 until it determines in step S33 that a fire recovery signal has been received from the receiver 10. When it determines that a fire recovery signal has been received, it returns to step S1 and repeats the same control operation.

In the control shown in Figs. 6 and 7, the receiver 10 distinguishes between white and black smoke fires, but the photoelectric smoke detector 14 may distinguish between white and black smoke fires and transmit a fire signal including identification information for white or black smoke fires to the receiver 10, and the entrance/exit management system 100 may perform fire judgment and fire alarm control in combination with the presence or absence of people in the room.

[Fire alarm system combined with motion sensor]
Fig. 8 is an explanatory diagram showing an embodiment of a fire alarm system combined with a human presence sensor. As shown in Fig. 8, in this embodiment, a human presence sensor 80 functioning as a human detection means is connected to a signal line 12-1 drawn from a receiver 10 via a repeater 16. The human presence sensor 80 receives infrared energy emitted from a human body by a pyroelectric element or the like, and outputs a human detection signal indicating the presence or absence of a person.

When the repeater 16 connected to the human sensor 80 receives a batch AD conversion signal transmitted from the receiver 10, it samples the human detection signal output by the human sensor 80 and stores the human detection information. When the repeater 16 subsequently receives a call signal transmitted from the receiver 10 specifying the address of the repeater 16 connected to the human sensor 80, it transmits a call response signal including the human detection information it is currently holding to the receiver 10.

The human presence sensor 80 is provided in a security area such as a room in which a photoelectric smoke detector 14 is installed. For example, the human presence sensor 80 is installed together with the photoelectric smoke detector 14 in security areas such as kitchens, smoking rooms, and bathrooms where non-fire factors are expected to occur.

The fire alarm control unit 48 provided in the main CPU 26 of the receiver 10 performs fire judgment and alarm control specific to this embodiment by combining the human detection information from the human presence sensor 80 and the discrimination results of white smoke fires and black smoke fires based on the photoelectric smoke detector 14.

In other words, the fire alarm control unit 48 determines that a white smoke fire exists when the ratio R of the smoke detection values A1, A2 detected by the photoelectric smoke detector 14 is equal to or greater than the ratio threshold value Rth = 5, and when it determines that a person is present as detected by the human presence sensor 80, it determines that there is some non-fire factor, and performs control to output a caution alarm without outputting a fire alarm.

The fire alarm control unit 48 also determines whether a fire is a white smoke fire based on the ratio R of the smoke detection values A1 and A2, and when the presence of people is detected by the human presence sensor 80, it determines that the fire is a white smoke fire in which white smoke is slowly increasing due to smoldering, and performs control to output a fire alarm indicating a white smoke fire.

On the other hand, when the ratio R of the smoke detection values A1, A2 falls below the ratio threshold Rth = 5 and thus determines that a black smoke fire has occurred, the fire alarm control unit 48 of the main CPU 26 performs control to output a fire alarm indicating a black smoke fire, regardless of the presence of people, since it can be determined that black smoke is being generated by a rapidly expanding burning fire and that the danger level is high.

In this embodiment, the human presence sensor 80 is installed together with the photoelectric smoke detector 14 in places where non-fire factors are likely to occur, such as smoking rooms and kitchens. For example, if white smoke and the presence of a person are detected in a smoking room, it is cigarette smoke, so a fire alarm is not issued and a caution alarm is output, and fire monitoring continues. Also, if white smoke is detected and no person is present, it is determined that a cigarette is still smoking and a fire alarm indicating a white smoke fire is output. Furthermore, if a black smoke fire is detected, a danger is imminent due to a burning fire, so a fire alarm indicating a black smoke fire is output regardless of whether or not a person is present, allowing for rapid evacuation.

Furthermore, when the fire alarm control unit 48 determines that a non-fire factor exists when the ratio R of the smoke detection values A1, A2 is equal to or greater than the non-fire factor threshold RSth = 12, and determines that a person is present as detected by the human presence sensor 80, it reserves the right to refrain from outputting a warning alarm indicating a non-fire factor. Note that if the non-fire factor is not resolved after a predetermined time has elapsed, the fire control unit 48 may cancel the reserve for output of the warning alarm and output a warning alarm indicating a non-fire factor.

On the other hand, the fire alarm control unit 48 determines whether a non-fire factor exists based on the ratio R of the smoke detection values A1 and A2, and when the human presence sensor 80 determines that no human is present, it performs control to output a warning alarm indicating a non-fire factor.

In this way, if people are present when a non-fire cause is identified, a warning alarm is deemed unnecessary and is withheld. On the other hand, if no people are present when a non-fire cause is identified, a warning alarm is issued, as this indicates that a non-fire cause such as steam from the bathroom or cooking smoke has been left unattended, allowing the necessary response to be taken.

Other than that, the configuration and functions of the fire alarm system 1 are the same as those of the embodiment shown in FIG. 1, so the same reference numerals are used and the description is omitted.

[Fire alarm equipment combined with security system]
Fig. 9 is an explanatory diagram showing an embodiment of a fire alarm system combined with a security system. As shown in Fig. 9, the fire alarm system 1 of this embodiment is basically the same as the embodiment of Fig. 1, and is characterized by the incorporation of a security system 200 that functions as a human detection means.

In the security system 200, a security sensor 206 is connected to a signal line 204 drawn from a security receiving panel 202. The security sensor 206 detects the intrusion of a suspicious person into the security zone, and transmits a security detection signal indicating the presence or absence of an intruder to the security receiving panel 202 via the signal line 204, causing a theft alarm to be output. As the security sensor 206, a sensor that detects infrared energy emitted by an intruder or a sensor that detects the opening of a window may be used.

The security receiving panel 202 is connected to a communication adapter 45 provided in the receiver 10 of the fire alarm system 1 via a communication adapter 208, and the fire alarm control unit 48 provided in the main CPU 26 of the receiver 10 is communicatively connected to the security system 200 via the communication adapters 45 and 208, thereby obtaining security monitoring information indicating the presence or absence of an intruder detected by the security sensor 206.

The fire alarm control unit 48 provided in the main CPU 26 of the receiver 10 performs fire judgment and alarm control specific to this embodiment by combining crime prevention monitoring information indicating the presence or absence of an intruder from the security system 200 and the results of discrimination between white smoke fires and black smoke fires based on the photoelectric smoke detector 14.

That is, the fire alarm control unit 48 determines that a white smoke fire has occurred when the ratio R of the smoke detection values A1, A2 detected by the photoelectric smoke detector 14 is equal to or greater than the ratio threshold value Rth = 5, and when it determines that an intruder has been detected by the security system 200, it determines that there is a high possibility that the white smoke has been caused by arson by an intruder, and therefore performs control to output a fire alarm indicating a white smoke fire.

On the other hand, when the fire alarm control unit 48 of the main CPU 26 determines that a black smoke fire has occurred because the ratio R of the smoke detection values A1 and A2 falls below the ratio threshold value Rth = 5, it determines that the black smoke caused by the rapidly expanding combustion fire is posing a high risk, and performs control to output a fire alarm indicating a black smoke fire, regardless of the presence of an intruder.

The fire alarm control unit 48 also determines that a non-fire factor has occurred when the ratio R of the smoke detection values A1 and A2 is equal to or greater than the non-fire factor threshold RSth = 12, and when it determines that there is no intruder detected by the security system 200, it performs control to withhold and not output a warning warning indicating a non-fire factor.

If the non-fire cause is not resolved after a predetermined time has elapsed, the fire control unit 48 may cancel the suspension of the warning alarm output and output a warning alarm indicating the non-fire cause.

Other than that, the configuration and functions of the fire alarm system 1 are the same as those of the embodiment shown in FIG. 1, so the same reference numerals are used and the description is omitted.

[Modifications of the present invention]
(Photoelectric smoke detector)
The above embodiment takes as an example a photoelectric smoke detector having a smoke detection section structure with one light-emitting element and two light-receiving elements, as shown in Figure 4, but is not limited to this and may be any photoelectric smoke detector with a smoke detection section structure that can obtain first and second smoke detection values A1, A2 by setting different wavelengths and scattering angles, for example, a photoelectric smoke detector with a smoke detection section structure with two light-emitting elements and one light-receiving element as shown in Patent Document 2.

In addition, in the above embodiment, when the photoelectric smoke detector receives a batch AD conversion signal from the receiver, it detects the first and second smoke detection values A1, A2 by driving the light-emitting element to emit light. However, the photoelectric smoke detector itself may detect the first and second smoke detection values A1, A2 by intermittently driving the light-emitting element to emit light at a predetermined cycle, regardless of instructions from the receiver.

(P-type fire alarm system)
The above embodiment takes as an example an R-type fire alarm system that monitors for fires by sending and receiving signals between a receiver and a photoelectric smoke detector with a set address, but the system may also be a P-type fire alarm system that, when the photoelectric smoke detector activates, sends a white smoke fire signal, a black smoke fire signal or a non-fire cause signal to the receiver without receiving instructions from the receiver, and outputs a white smoke fire alarm, a black smoke fire alarm, or a non-fire alarm caution alarm.

In such a P-type fire alarm system, a photoelectric smoke detector sends an alarm current to the signal line from the receiver, which transmits a white smoke fire signal, black smoke fire signal, or non-fire cause signal to the receiver. In order to distinguish between the white smoke fire signal, black smoke fire signal, and non-fire cause signal, a unique frequency signal or pulse code signal is superimposed on the alarm current, allowing the receiver to distinguish between the smoke fire signal, black smoke fire signal, and non-fire cause signal and output a white smoke fire alarm, black smoke fire alarm, or non-fire cause warning alarm.

In addition, the interlocking control of control devices such as local sound devices, exhaust devices, and fire extinguishing devices in a P-type fire alarm system is P-type interlocking control that is performed on a line-by-line basis.

(Determination of non-fire causes)
In the above embodiment, in addition to judging white smoke and black smoke, a judgment is also made regarding non-fire causes. However, it is also possible to make only a judgment regarding white smoke and black smoke without making a judgment regarding non-fire causes.

(Fire alarm system)
The above embodiment has been described as an example of a wired system in which a photoelectric smoke detector is connected to a signal line from a receiver, but it may also be a wireless system in which the receiver and the photoelectric smoke detector are connected by a wireless line.

(Comparative judgment)
In the above embodiment, for example, the comparison of the ratio R and the ratio threshold value Rth is performed in the cases of R≧Rth and R<Rth, but the present invention is not limited to this, and the comparison may be performed in the cases of R>Rth and R≦Rth. The same applies to comparisons of other values.

(others)
Furthermore, the present invention includes appropriate modifications that do not impair the objects and advantages of the present invention, and is not limited to the numerical values shown in the above embodiment.

1: Fire alarm system 10: Receiver 12, 12-1 to 12-3: Signal line 14: Photoelectric smoke detector 16: Repeater 18: Local sound device 20: Exhaust device 22: Fire door 26: Main CPU
28-1 to 28-3: Sub CPU board 30: Sub CPU
32: Transmission unit 34: Serial transfer bus 36: Display 38: Display unit 40: Operation unit 42: Acoustic alarm unit 44: Reporting unit 45, 114, 208: Communication adapter 46: Transmission control unit 48: Fire alarm control unit 50: Sensor control unit 52: Transmission unit 54: Power supply unit 56: Light emission driving unit 60: Smoke detection unit 62: Light emitting element 62a, 64a, 66a: Optical axis 64: First light receiving element 66: Second light receiving element 68, 70: Amplification circuit unit 80: Human presence sensor 100: Entrance/exit management system 102: Center device 104: Client 106: LAN line 108: Local control panel 110: Card reader 112: Electric lock 200: Security system 202: Security receiving panel 206: Security sensor

Claims (3)

In a fire alarm system that monitors and warns of fires in a warning area ,
a fire detector that detects a fire in the warning area and transmits a fire signal;
a human detection means for detecting the presence or absence of a human in the alert area and transmitting a detection signal;
a fire alarm control unit that controls an alarm operation based on the fire signal from the fire detector and the detection signal from the human detection means;
Equipped with
The fire alarm control unit is
When it is determined that a fire has a low level of danger and that a person is present in the warning area based on the fire signal and the detection signal, a caution alarm is output without outputting a fire alarm;
outputting a fire alarm when determining that a fire with a low level of danger and that no people are present in the warning area based on the fire signal and the detection signal;
When a fire with a high risk of danger is determined based on the fire signal, a fire alarm is output regardless of whether or not a person is present in the warning area;
Distinguishing non-fire causes based on the fire signal;
when it is determined that a person is present in the alert area based on the detection signal after determining that the non-fire factor has occurred, output of a warning indicating the occurrence of a non-fire factor is suspended;
A fire alarm system characterized in that when it determines that there is no person present in the alert area based on the detection signal after determining that the non-fire factor has occurred, it outputs a warning alarm indicating the occurrence of the non-fire factor.
The fire alarm system according to claim 1,
The fire alarm control unit outputs different fire alarms according to the determined degree of fire danger.
In the fire alarm system according to claim 1 or 2,
A fire alarm system characterized in that low-risk fires determined by the fire alarm control unit include white smoke fires, and high-risk fires determined by the fire alarm control unit include black smoke fires.

Images