JP7731336B2 - Fire detectors and systems equipped with fire detectors - Google Patents

Description

The present invention relates to a fire detector and a system equipped with a fire detector.

Conventionally, a system has been proposed that includes a wireless fire detector equipped with a wireless communication unit connected to an antenna and that intermittently transmits messages in accordance with the standard for specific low-power radio stations in the 400 MHz band, for example, and a repeater that communicates with this fire detector (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2022-19917

The fire detector disclosed in Patent Document 1 transmits radio waves that comply with the standard for specified low-power radio stations, such as the 400 MHz band, to communicate with a repeater. Recently, Wi-Fi environments have been increasingly installed in buildings where fire detectors are installed, and a wide variety of devices use radio waves. As a result, interference between these radio waves becomes a problem. Communication between fire detectors and other devices can occur when installing fire detectors in buildings or when inspecting fire detectors after installation. Both tasks require speed, and it is desirable to avoid delays in work due to communication delays caused by radio wave interference. It is also desirable to avoid interference with Wi-Fi communication and the use of radio waves by other devices due to radio wave interference. For this reason, there has been a demand for technology that allows fire detectors to communicate with other devices without using radio waves.

The present invention addresses the above-mentioned challenges and provides a fire detector and a system equipped with a fire detector that can communicate with other devices without using radio waves.

The fire detector of the present invention comprises a sensing unit that detects changes in physical phenomena due to a fire, and a confirmation light that turns on when the sensing unit detects a fire. The confirmation light outputs a Li-Fi (optical wireless communication) signal when the sensing unit does not detect a fire.

The system of the present invention comprises the above-mentioned fire detector and a terminal equipped with a light-receiving element that receives the Li-Fi signal and an output device that outputs information based on the received Li-Fi signal.

According to this invention, the confirmation light installed in the fire detector, which lights up when a fire is detected, outputs an Li-Fi signal, allowing the fire detector to output a signal to other devices without using radio waves.

1 is a diagram illustrating the configuration of a system including a fire detector according to a first embodiment. 1 is a functional block diagram of a fire detector according to a first embodiment. FIG. FIG. 2 is a functional block diagram of a terminal according to the first embodiment.

Embodiments of a fire detector and a system equipped with a fire detector according to the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments and the illustrated aspects, and various modifications are possible without departing from the spirit of the present invention. The present invention also includes all possible combinations of the configurations shown in the following embodiments. In addition, parts with the same reference numerals in each figure are the same or equivalent, and this applies throughout the entire specification. In the following description, terms indicating directions will be used as appropriate to facilitate understanding, but these are for explanatory purposes and do not limit the present invention. Examples of directional terms include "up," "down," "right," "left," "front," and "rear."

Embodiment 1.
(Configuration of system 100)
FIG. 1 is a diagram illustrating the configuration of a system 100 including a fire detector 10 according to a first embodiment. The system 100 detects a fire and outputs an alarm. The system 100 is installed in a building that is a fire prevention target, such as an apartment building or an underground facility such as an underground shopping mall. The system 100 includes a fire detector 10 having a confirmation light 11 and a terminal 20 that communicates with the fire detector 10. The system 100 of this embodiment further includes a fire receiver 30 connected to one or more fire detectors 10 via a signal line 31. While this embodiment illustrates the system 100 to which a P-type fire receiver 30 is connected, the present invention is also applicable to a system to which an R-type fire receiver is connected.

When fire detector 10 detects a fire, confirmation light 11 illuminates to visually notify the user in the location where fire detector 10 is installed, and outputs a fire signal via signal line 31. Fire receiver 30 supplies power to fire detector 10 via signal line 31 and receives the fire signal output from fire detector 10 via signal line 31. Signal line 31 consists of a pair of electrical wires. When fire receiver 30 receives a fire signal from fire detector 10, it activates one or more of various devices connected to fire receiver 30 via a signal line (not shown), such as an audio alarm device, a visual alarm device, and an optical alarm device, to issue a fire alarm and operate smoke control and evacuation devices such as fire doors and shutters.

In the example shown in Figure 1, a building in which the system 100 is installed is divided into multiple alert zones, and a signal line 31 is installed in each alert zone and a fire receiver 30 is connected to it. In Figure 1, the signal lines 31 for each alert zone are shown separately as sensor lines 32a, 32b, and 32c. Fires can be detected for each of the multiple sensor lines 32a to 32c.

Li-Fi (Light Fidelity) communication, a wireless communication method using visible light, is carried out between the fire detector 10 and the terminal 20. The check light 11 of the fire detector 10 outputs an optical signal for Li-Fi communication, and the terminal 20 receives the optical signal output from the check light 11.

(Fire detector 10)
2 is a functional block diagram of the fire detector 10 according to embodiment 1. The fire detector 10 includes a detector 12, a confirmation light 11, a controller 13, a memory 14, a lighting circuit 15, and a switching circuit 16.

The sensing unit 12 detects physical phenomena or changes in physical phenomena caused by a fire, such as smoke, infrared rays, ultraviolet rays, or combustion gases. Information on the physical phenomena or changes in physical phenomena caused by a fire detected by the sensing unit 12 is input as a signal to the control unit 13, which then determines whether a fire has occurred. If the fire detector 10 is a heat detector, the sensing unit 12 includes a temperature detection element, such as a thermistor, or a thermocouple, that detects temperature. If the fire detector 10 is a smoke detector, the sensing unit 12 is an ionization or photoelectric smoke detector that detects smoke concentration. If the fire detector 10 is a flame detector, the sensing unit 12 is an ultraviolet or infrared flame detector. If the fire detector 10 is a gas detector, the sensing unit 12 is a gas sensor. If the fire detector 10 is a combination detector, the sensing unit 12 includes multiple sensing units 12 as exemplified above. If the fire detector 10 and fire receiver 30 are analog, information about the physical phenomenon or change in the physical phenomenon detected by the fire detector 10 is input to the fire receiver 30, which then determines whether or not a fire has occurred.

The control unit 13 controls the overall operation of the fire detector 10. The control unit 13 determines whether or not a fire has occurred based on signals of physical phenomena caused by a fire input from the detection unit 12. If it determines that a fire has occurred, it controls the lighting circuit 15 to light the confirmation light 11 and outputs a control signal to the switching circuit 16. The control unit 13 is composed of a dedicated control circuit, a CPU (Central Processing Unit) that executes programs stored in memory, or a combination of these. If the control unit 13 is a CPU, the functions executed by the control unit 13 are realized by software, firmware, or a combination of software and firmware.

The memory unit 14 is a non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, or EEPROM. The memory unit 14 stores various information written when the fire detector 10 was manufactured, as well as various information written by the control unit 13 while the fire detector 10 was in operation. The memory unit 14 stores threshold data that the control unit 13 compares with the information detected by the detection unit 12 when determining whether a fire has occurred. The memory unit 14 also stores individual identification information that is uniquely assigned to each fire detector 10. The memory unit 14 also stores one or more of the following: information indicating whether the fire detector 10 is a terminal terminal, and status information for the fire detector 10. These pieces of information will be described later.

The confirmation light 11 visually indicates that the fire detector 10 has detected a fire. The confirmation light 11 is a light-emitting diode (LED) that emits visible light, such as red. The confirmation light 11 may be arranged in a circular ring shape on the outer surface of the housing of the fire detector 10, or two or more confirmation lights 11 may be arranged so that they can be seen from any direction around the fire detector 10, which is installed on a ceiling, wall, etc.

The lighting circuit 15 controls the lighting state of the confirmation light 11 based on a signal from the control unit 13. When a switch provided in the lighting circuit 15 is turned on, the confirmation light 11 lights up. When the lighting circuit 15 is to keep the confirmation light 11 lit continuously, it keeps this switch on. When outputting an Li-Fi signal from the confirmation light 11, the lighting circuit 15 turns the switch on and off at high speed, causing the confirmation light 11 to output a high-speed modulated optical signal.

The switching circuit 16 is a self-holding circuit that is turned on based on a signal from the control unit 13. The switching circuit 16 is connected to the signal line 31. When the switching circuit 16 remains on, the impedance between the pair of wires that make up the signal line 31 connected to the fire receiver 30 changes from high to low, and a fire signal is output to the fire receiver 30.

(Terminal 20)
3 is a functional block diagram of the terminal 20 according to embodiment 1. The terminal 20 includes a receiving unit 21, a control unit 22, a storage unit 23, and a display device 24.

The receiving unit 21 receives the Li-Fi signal output from the confirmation light 11 of the fire detector 10. The receiving unit 21 includes a photodiode that outputs the detected light as an electrical signal. The light receiving element of the photodiode is preferably provided with a lens to control the light receiving range of the light receiving element. The electrical signal output by the receiving unit 21 is input to the control unit 22. The receiving unit 21 is provided on the outer surface of the terminal 20 so that it can receive light from the confirmation light 11 of the fire detector 10.

The control unit 22 converts the electrical signal input from the receiving unit 21 into data such as numbers or letters. The control unit 22 stores the data such as numbers or letters in the memory unit 23, and also displays the data such as numbers or letters on the display unit 24 based on instructions from an input device of the terminal 20 (not shown).

The memory unit 23 is a non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, or EEPROM. The memory unit 23 stores various information written to the terminal 20 during its manufacture, as well as information based on the Li-Fi signal received from the fire detector 10 via the receiver 21.

The display device 24 is a device that displays information based on the Li-Fi signal from the fire detector 10. The display device 24 is, for example, a liquid crystal display, an organic EL display, or electronic paper. The display device 24 is an example of an output device that outputs information. Instead of or in addition to the display device 24, a speaker that outputs information as audio may be provided as an output device.

(operation)
The operation of the system 100 according to the first embodiment will be described. The fire detector 10 is in a monitoring state where it routinely monitors for the occurrence of a fire. When the fire detector 10 in the monitoring state detects a fire, the check light 11 lights up to alert the user of the fire, and a fire signal is output to the fire receiver 30.

Furthermore, when a fire detector 10 in monitoring mode does not detect a fire, it transmits information stored in the fire detector's 10 memory unit 14 to the terminal 20 by outputting a Li-Fi signal from the confirmation light 11. The terminal 20 receives the Li-Fi signal from the fire detector 10 and displays the received information on the display device 24. This allows workers using the terminal 20, such as maintenance personnel or inspectors, to check the information from the fire detector 10. It is also advisable to change the lighting pattern of the confirmation light 11 depending on whether a fire is being detected or not. For example, the confirmation light 11 lights continuously when a fire is being detected and flashes when a Li-Fi signal is being output. By changing the lighting pattern of the confirmation light 11 depending on the purpose of lighting in this way, it is less likely that the user will be confused about whether a fire has been detected or not.

The following describes the information output from the fire detector 10 using the Li-Fi signal. The fire detector 10 outputs one or more of the following: information stored in the memory unit 14 indicating whether the fire detector 10 is a terminal terminal, and status information about the fire detector 10.

This section explains information regarding whether a fire detector 10 is a terminal terminal. A terminal terminal is a fire detector 10 that includes a terminating resistor or terminator connected to the signal line 31. In the example of Figure 1, the fire detector 10 attached to the end of each signal line is a terminal terminal. The terminal terminal can be set, for example, using an address setting device after the fire detector 10 is installed, or by providing a DIP switch (not shown) on the fire detector 10 and turning on the DIP switch of the detector to be used as the terminal terminal. If the signal line 31 is divided into multiple sensor lines, a terminal terminal is provided for each sensor line. In the example of Figure 1, there are three sensor lines 32a-32c, and one of the fire detectors 10 connected to each of the sensor lines 32a-32c is a terminal terminal. In a system 100 that is installed in a building and used for an extended period of time, the location of the terminal terminals may become unclear after some time has passed since installation. In particular, when the contractor for system 100 and the contractor for system 100's maintenance are different, it is difficult to share information about the terminal terminal. To find the terminal terminal during maintenance, it is necessary to remove each of the multiple fire detectors 10 installed in the building and remove the covers of the fire detectors 10 to check them, and this workload increases as the scale of system 100 increases. Therefore, by transmitting information to terminal 20 regarding whether or not the fire detector 10 is a terminal terminal when an instruction signal is received from terminal 20 or fire receiver 30, the worker using terminal 20 can easily find the terminal terminal from among the multiple fire detectors 10.

Information indicating the status of the fire detector 10 includes information indicating whether it is a terminal terminal, as well as one or more of the following: sensitivity information of the sensing unit 12, information indicating the amount of dirt on the sensing unit 12, trend information, and manufacturing-related information. By transmitting such status information from the fire detector 10 to the terminal 20, the worker using the terminal 20 can grasp the information about the fire detector 10 without removing or disassembling the fire detector 10.

Sensitivity information indicates whether the sensitivity of the sensing unit 12 is normal and the degree of deviation from the reference sensitivity value. The sensitivity of the sensing unit 12, which detects smoke, infrared rays, ultraviolet rays, combustion gases, etc., changes over time. The sensitivity of the sensing unit 12 also changes depending on the degree of contamination around the sensing unit 12. For this reason, the fire detector 10 is provided with a determination unit (not shown) that periodically determines whether the analog value (also known as sensor output) of the sensing unit 12 stored in the memory unit 14 is appropriate and determines the degree of contamination (amount of contamination) of the sensing unit 12. The fire detector 10 stores sensitivity information detected based on the degree of contamination in the memory unit 14. By transmitting this sensitivity information from the fire detector 10 to the terminal 20, an operator using the terminal 20 can easily obtain information regarding the sensitivity of the sensing unit 12 of the fire detector 10. Therefore, if there is an abnormality in sensitivity, it becomes easier to take measures such as cleaning the sensing unit 12 and its surrounding area or replacing the fire detector 10, thereby maintaining good monitoring status of the fire detector 10.

Trend information is a history of analog values of physical phenomena detected by the sensing unit 12 over a certain period of time. The amount of smoke, infrared rays, ultraviolet rays, combustion gases, etc. detected by the sensing unit 12 may change rapidly or slowly depending on various conditions, such as the nature of the fire or the structure of the building. The fire detector 10 stores the analog values of physical phenomena detected by the sensing unit 12 as history in the memory unit 14. For example, if the fire detector 10 is a heat detector, temperature information is stored as trend information, and if the fire detector 10 is a smoke detector, smoke concentration is stored as trend information. The trend information is stored in the memory unit 14, for example, in a ring buffer format. By transmitting the trend information from the fire detector 10 to the terminal 20, an operator using the terminal 20 can check the history of information detected by the sensing unit 12 of the fire detector 10. Because the trend information also indicates changes in the sensing unit 12 over time, operators can understand changes in the sensing unit 12 by checking the trend information on the terminal 20.

The manufacturing-related information of the fire detector 10 is information such as the year of manufacture, serial number, or model of the fire detector 10. By transmitting the manufacturing-related information from the fire detector 10 to the terminal 20, the worker using the terminal 20 can easily replace the fire detector 10 or other equipment connected to the fire detector 10 when renewing the system 100.

Next, we will explain the timing at which the fire detector 10 outputs the above-mentioned information using an Li-Fi signal. The fire detector 10 is equipped with a transceiver (not shown) for communicating with the fire receiver 30. It receives signals from the fire receiver 30, and the control unit 13 performs the necessary processing depending on the content of the signal. Here, the control unit 13 determines whether the signal from the fire receiver 30 is a signal to output terminal information, sensitivity information, or trend information, and outputs the corresponding Li-Fi signal. The Li-Fi signal can be output based on a signal received from the fire receiver 30 via signal line 31. Specifically, the fire receiver 30 periodically, or when an operation to start a test is input to the fire receiver 30, transmits a test signal to the fire detector 10 via signal line 31, instructing the fire detector 10 to conduct a test. Upon receiving the test signal, the fire detector 10 outputs an Li-Fi signal from the confirmation light 11. When the fire detector 10 receives a test stop signal from the fire receiver 30 instructing the fire detector 10 to stop the test, it stops outputting the Li-Fi signal. Alternatively, the fire detector 10 may stop outputting the Li-Fi signal after a predetermined time has elapsed since it started outputting the Li-Fi signal.

Instead of, or in addition to, outputting an Li-Fi signal in response to a test signal from the fire receiver 30, the fire detector 10 may output an Li-Fi signal in response to a signal from the terminal 20. Specifically, the fire detector 10 has a receiver (not shown) for communicating with the terminal 20 and receiving signals from the terminal 20. Upon receiving the signal from the terminal 20, the control unit 13 performs the necessary processing depending on the content of the signal. Here, the control unit 13 determines whether the signal from the terminal 20 is a signal to output terminal terminal information, sensitivity information, or trend information, and outputs the corresponding Li-Fi signal (similar function to the transceiver unit described above). The terminal 20 outputs a test signal using Li-Fi communication, and the fire detector 10 outputs an Li-Fi signal upon receiving the test signal from the terminal 20. In this case, the terminal 20 has a lighting circuit and a light-emitting diode with functions equivalent to the lighting circuit 15 and confirmation light 11 of the fire detector 10. The fire detector 10 also has a receiver on the exterior of its housing that includes a light-receiving element with the same functionality as the receiver 21 of the terminal 20. In this way, two-way communication using Li-Fi signals between the terminal 20 and the fire detector 10 allows the worker using the terminal 20 to output an Li-Fi signal to the fire detector 10 at any time of their choosing.

Furthermore, the fire detector 10 may output a Li-Fi signal when a hardware operation unit, such as a button or switch, provided on the housing is operated. For example, if the fire detector 10 is provided with a hardware operation unit for conducting tests or stopping a fire, the fire detector 10 will output a Li-Fi signal when a special operation, such as a long press, is performed on the hardware operation unit. In this way, the operator can cause the fire detector 10 to output a Li-Fi signal at any timing desired. Furthermore, by utilizing the hardware operation unit provided on the fire detector 10, the timing of the Li-Fi signal output can be instructed without installing any additional structure on the fire detector 10.

As described above, the system 100 of this embodiment includes a fire detector 10 and a terminal 20. The fire detector 10 includes a sensing unit 12 that detects changes in physical phenomena due to a fire, and a confirmation light 11 that turns on when the sensing unit 12 detects a fire. The confirmation light 11 outputs an Li-Fi signal when the sensing unit 12 does not detect a fire. This allows signals to be output from the fire detector 10 to the terminal 20 without using radio waves. The confirmation light 11 notifies the user of a fire, and also functions as an optical communication device when no fire has occurred. Because the confirmation light 11 outputs an Li-Fi signal, the fire detector 10 does not need to be equipped with a dedicated communication circuit for outputting signals from the fire detector 10 to the terminal 20. This avoids increases in the manufacturing costs and size of the fire detector 10.

In the embodiment, a configuration has been described in which the Li-Fi signal is output using the confirmation light 11, but a dedicated indicator light for outputting the Li-Fi signal may be provided separately from the confirmation light 11. Furthermore, the terminal 20 that receives the Li-Fi signal from the fire detector 10 outputs information based on the Li-Fi signal using an output device such as the display device 24, allowing the worker using the terminal 20 to easily understand the information.

In addition, the confirmation light 11 of the fire detector 10 outputs, via a Li-Fi signal, either or both of information indicating whether the fire detector 10 is the terminal terminal of the detector lines 32a to 32c and information indicating the status of the fire detector 10. Therefore, an operator using a terminal 20 that receives an Li-Fi signal from the fire detector 10 can ascertain information about the fire detector 10 without removing or disassembling the fire detector 10.

10 Fire detector, 11 Confirmation light, 12 Detection unit, 13 Control unit, 14 Memory unit, 15 Lighting circuit, 16 Switching circuit, 20 Terminal, 21 Receiving unit, 22 Control unit, 23 Memory unit, 24 Display device, 30 Fire receiver, 31 Signal line, 32a Detector line, 32b Detector line, 32c Detector line, 100 System.

Claims (3)

a sensing unit that detects a change in a physical phenomenon due to a fire;
a confirmation light that is turned on when the detection unit detects a fire,
The confirmation light outputs a Li-Fi signal when the sensing unit does not detect the occurrence of a fire. The fire detector according to claim 1, wherein the confirmation light outputs, via the Li-Fi signal, either or both of information indicating whether the fire detector is a terminal terminal in a detector line and information indicating the status of the fire detector. The fire detector according to claim 1 or 2;
a terminal including a light receiving element that receives the Li-Fi signal and an output device that outputs information based on the received Li-Fi signal;
A system with.