Fire sensor

Abstract

To provide a fire sensor that can perform inactivation and sterilization of viruses even in a large space without having a harmful effect on a human body.SOLUTION: A photoelectric separation type fire sensor having a light-transmitting unit and a light-receiving unit, includes an ultraviolet light emission unit for emitting ultraviolet light for sterilization in a direction along an optical axis of infrared light for smoke detection.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a fire detector that uses disinfecting ultraviolet light to inactivate viruses and sterilize. [Background technology]

[0002] Infectious diseases caused by viruses and other pathogens have become a problem in recent years. Infectious diseases transmitted by droplets containing viruses or bacteria, or droplet nuclei formed when water from droplets evaporates, are more easily transmitted than by contact. While droplets containing viruses and other pathogens tend to fall, droplet nuclei formed when water evaporates from droplets are small and light, and therefore remain suspended in the air for long periods of time, becoming the cause of airborne infection. Ultraviolet irradiation using ultraviolet LEDs is effective in inactivating and sterilizing viruses and bacteria suspended in the air in the form of droplet nuclei. However, because ultraviolet light also has adverse effects on the human body, Patent Document 1 irradiates ultraviolet light inside a smoke detector. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-36380 Summary of the Invention [Problem to be solved by the invention]

[0004] The ultraviolet irradiation inside a smoke detector, as in Patent Document 1, is not suitable for inactivating or sterilizing viruses in large spaces because the amount of air irradiated is small. An object of the present invention is to provide a fire detector that can inactivate or sterilize viruses even in large spaces without adversely affecting the human body. [Means for solving the problem]

[0005] One embodiment of the present invention is a photoelectric separated fire detector having a light transmitting unit and a light receiving unit, characterized in that it is equipped with an ultraviolet light emitting unit that emits ultraviolet light for sterilization in a direction along the optical axis of infrared light for smoke detection. [Effects of the Invention]

[0006] According to the present invention, it is possible to inactivate and sterilize viruses even in large spaces without adversely affecting the human body in the area where the fire detector is used. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing a P-type fire detection system equipped with a fire detector according to a first embodiment of the present invention. [Figure 2] FIG. 1 is a diagram showing an installation state of fire detectors according to a first embodiment of the present invention. [Figure 3] 1 is a diagram showing a fire detector in a fire detection system according to a first embodiment of the present invention; [Figure 4] FIG. 2 is a diagram showing timing pulses of the fire detector according to the first embodiment of the present invention. [Figure 5] FIG. 10 is a diagram showing a fire detector in a fire detection system according to a second embodiment of the present invention. [Figure 6] FIG. 10 is a diagram showing timing pulses of a fire detector according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a diagram showing a fire detector in a fire detection system according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [Example]

[0008] FIG. 1 shows a P-type fire detection system including a fire detector 1 according to a first embodiment of the present invention. The fire detector 1 is a photoelectric separation type, and transmits infrared light for smoke detection from a light-transmitting unit 11 to an opposing light-receiving unit 12. When a fire breaks out, smoke enters between the light-transmitting unit 11 and the light-receiving unit 12, reducing the amount of received infrared light for smoke detection, causing the fire detector 1 to detect the smoke. A plurality of photoelectric separation type fire detectors 1 are provided, and a terminal provided on the light-receiving unit 12 is connected to a P-type receiver 2 via a fire signal line 3 via a crossover wiring. The light-transmitting unit 11 is connected to the light-receiving unit 12 via a synchronization line 13.

[0009] 2 shows the installation state of the fire detector 1 in Example 1. In Example 1, an ultraviolet light emitting unit 112 is provided in the light transmitting unit 11, and sterilizing ultraviolet light UV is emitted from the light transmitting unit 11 toward the light receiving unit 12. In the photoelectric separated fire detector 1, the light transmitting unit 11 and the light receiving unit 12 are both installed facing each other at a high position such as near the ceiling. Particularly in a large space, the light transmitting unit 11 and the light receiving unit 12 are usually installed facing each other at a position that a person H cannot reach unless high scaffolding or the like is used.

[0010] In the photoelectric separate fire detector 1, a synchronization signal is transmitted from the light receiving unit 12 to the light transmitting unit 11 via the synchronization line 13. Upon receiving the synchronization signal, the light transmitting unit 11 causes the infrared emitting unit 111 to emit infrared light IR for smoke detection toward the infrared receiving unit 121 in the light receiving unit 12. The synchronization signal is transmitted periodically, and the infrared light IR for smoke detection is emitted periodically. The light receiving unit 12 detects smoke based on a change in the amount of received light of the infrared light IR for smoke detection at the timing when the synchronization signal is transmitted.

[0011] The light-transmitting unit 11 is provided with an ultraviolet light-emitting unit 112 above the infrared light-emitting unit 111 when the fire detector 1 is installed. The ultraviolet light-emitting unit 112 emits sterilization ultraviolet light UV in a direction along the optical axis of the smoke detection infrared light IR.

[0012] The sterilizing ultraviolet light UV is emitted from the light-transmitting unit 11 of the fire detector 1 in a direction along the smoke detection infrared light IR. To prevent false detection of smoke, the fire detector 1 is installed at a high place where the smoke detection infrared light IR is not blocked by people H, etc., so that the emitted sterilizing ultraviolet light UV is unlikely to be directly irradiated onto people H. Furthermore, in Example 1, when the fire detector 1 is installed, the ultraviolet light emitter 112 is provided above the infrared light emitter 111, and the sterilizing ultraviolet light UV is emitted in a direction along the optical axis of the smoke detection infrared light IR. Therefore, the irradiation position of the sterilizing ultraviolet light UV is above the smoke detection infrared light IR, further reducing the possibility of it being directly irradiated onto people H.

[0013] The sterilization ultraviolet light UV is attenuated in space and hardly reaches the light receiving unit 12. Therefore, it does not deteriorate the infrared light receiving unit 121 provided in the light receiving unit 12. However, when the light receiving unit 12 is installed near the light sending unit 11, there is a possibility that the sterilization ultraviolet light UV and its scattered light will reach the infrared light receiving unit 121, so an ultraviolet cut filter may be installed in front of the infrared light receiving unit 121.

[0014] FIG. 3 shows a fire detector 1 in a P-type fire detection system in Example 1 of the present invention. The fire detector 1 transmits infrared light IR for smoke detection from the infrared light emitting unit 111 of the light transmitting unit 11 to the infrared light receiving unit 121 of the light receiving unit 12. A terminal provided on the light receiving unit 12 is connected to the P-type receiver 2 by a fire signal line 3. When the fire detector 1 detects smoke, it lowers the resistance between the fire signal line 3 and notifies the P-type receiver 2 of the smoke detection. The light transmitting unit 11 is connected to the light receiving unit 12 by a synchronization line 13. Furthermore, power is supplied to the infrared light emitting unit 111 and the ultraviolet light emitting unit 112 provided in the light transmitting unit 11 from a light emitting power source 113.

[0015] Next, the operation of the fire detector 1 will be explained with reference to Figure 4. Figure 4 shows, from top to bottom, the timing of the voltage of the synchronization line 13, the input voltage of the infrared light emitting unit 111 in the light transmitting unit 11, the output voltage of the infrared light receiving unit 121 in the light receiving unit 12, the input voltage of the ultraviolet light emitting unit 112 in the light transmitting unit 11, and the voltage of the fire signal line 3 connected to the light receiving unit 12. Time flows to the right. Figure 4 shows the same peak value, but Figure 4 shows the timing of the voltages, and the values ​​of each voltage will generally be different.

[0016] The light receiving unit 12 periodically raises the voltage on the synchronization line 13. In the light transmitting unit 11, (a) the rising edge of the voltage on the synchronization line 13 triggers a one-shot circuit (not shown) to operate, applying a voltage to the infrared emitting unit 111 for a predetermined period. (b) The infrared emitting unit 111, to which voltage is applied, emits smoke detection infrared light IR, which is received by the infrared receiving unit 121 of the light receiving unit 12, causing the output voltage of the infrared receiving unit 121 to rise. (c) When the predetermined period ends, the input voltage to the infrared emitting unit 111 of the light transmitting unit 11 drops, causing the smoke detection infrared light IR to disappear. The infrared receiving unit 121 of the light receiving unit 12 no longer receives the smoke detection infrared light IR, causing the output voltage of the infrared receiving unit 121 to fall. (d) The light receiving unit 12 lowers the voltage on the synchronization line 13, triggered by the falling edge of the output voltage of the infrared receiving unit 121. (e) In the light-transmitting unit 11, the falling edge of the voltage on the synchronization line 13 is used as a trigger to activate a one-shot circuit (not shown) and apply a voltage to the ultraviolet light emitter 112 for a predetermined period of time. This causes the ultraviolet light emitter 112 to emit sterilization ultraviolet light UV for the predetermined period of time.

[0017] If the smoke detection infrared light IR between the light transmitting unit 11 and the light receiving unit 12 is blocked by a person H, smoke, etc., the following occurs as shown in the latter half of Figure 4: (a1) The rising edge of the voltage on the synchronization line 13 triggers the activation of a one-shot circuit (not shown), which applies voltage to the infrared light emitting unit 111 for a predetermined period of time. (f1) (g1) After the rising edge of the voltage on the synchronization line 13, the smoke detection infrared light IR does not reach the infrared light receiving unit 121, so smoke is detected and the fire signal line 3 is short-circuited. This causes the detection of smoke by the fire detector 1 to be communicated to the P-type receiver 2.

[0018] 4, (d1) the output voltage does not rise in the infrared receiving unit 121, so there is no voltage drop in the synchronization line 13 triggered by the falling edge of the output voltage. Therefore, the voltage of the synchronization line 13 remains high. As a result, (e1) voltage is not applied to the ultraviolet light emitter 112 triggered by the falling edge of the voltage of the synchronization line 13, and the sterilization ultraviolet light UV is not emitted and stops emitting.

[0019] If a person H blocks the smoke detection infrared light IR between the light-transmitting unit 11 and the light-receiving unit 12 due to inspection work or the like, voltage is not applied to the ultraviolet light-emitting unit 112 as described above, and the sterilization ultraviolet light UV is not emitted. Therefore, the sterilization ultraviolet light UV is not irradiated onto the person H.

[0020] In the first embodiment, the sterilization ultraviolet light UV is emitted when the light receiving voltage of the smoke detection infrared light IR drops. In this way, in the first embodiment, the light emission timing of the infrared light emitting unit 111 and the ultraviolet light emitting unit 112, which consume a large amount of power, is shifted to suppress peak power consumption. In addition, the light emission power source only needs to be connected to the light transmitting unit 11, and does not need to be connected to the light receiving unit 12. This allows the fire detector 1 to be realized with less wiring and transformer devices.

[0021] <Modification> In the first embodiment, the peak power consumption is reduced by staggering the emission timing of the smoke detection infrared light IR and the sterilization ultraviolet light UV, but the emission timings may overlap without staggering. Furthermore, the sterilization ultraviolet light UV may be continuously emitted until the smoke detection infrared light IR is blocked and turned off. In the first embodiment, information is transmitted from the light-receiving unit 12 to the light-transmitting unit 11 via the synchronization line 13 using a simple voltage. However, other transmission methods, such as digital communication, may also be used. When transmitting information via digital communication, in addition to emitting the smoke detection infrared light IR and the sterilization ultraviolet light UV via digital communication from the light-receiving unit 12, time information, such as emitting the smoke detection infrared light IR at 100 m / s or emitting the sterilization ultraviolet light UV for 1 second, may also be transmitted to the light-transmitting unit 11 via digital communication. In the first embodiment, a P-type fire detection system using a P-type receiver 2 is used. However, an R-type fire detection system using an R-type receiver may also be used. [Example]

[0022] Fig. 5 shows a fire detector 4 in a P-type fire detection system according to a second embodiment of the present invention. The P-type fire detection system including the fire detector 1 shown in Figs. 1 and 2 and the installation status of the fire detector 1 are the same in the second embodiment. However, unlike the first embodiment, the second embodiment has an ultraviolet light emitting unit 422 provided in the light receiving unit 42.

[0023] The fire detector 4 transmits infrared light IR for smoke detection from the infrared light emitting unit 411 of the light transmitting unit 41 to the infrared light receiving unit 421 of the light receiving unit 42. A terminal provided on the light receiving unit 42 is connected to the P-type receiver 2 by a fire signal line 3. The light transmitting unit 41 is connected to the light receiving unit 42 by a synchronization line 43. Furthermore, the infrared light emitting unit 411 of the light transmitting unit 41 is supplied with power from a light emission power supply 412, and the ultraviolet light emitting unit 422 of the light receiving unit 42 is supplied with power from a light emission power supply 423.

[0024] In the second embodiment, the light receiving unit 42 is provided with an infrared light receiving unit 421 and an ultraviolet light emitting unit 422. Therefore, the control for blocking the smoke detection infrared light IR, preventing the infrared light receiving unit 421 from receiving light, and preventing the ultraviolet light emitting unit 422 from emitting light can be processed inside the light receiving unit 42.

[0025] Next, the operation of the fire detector 4 will be explained using Figure 6. Figure 6 shows, from top to bottom, the timing of the voltage of the synchronization line 43, the input voltage of the infrared light emitting unit 411 in the light transmitting unit 41, the output voltage of the infrared light receiving unit 421 in the light receiving unit 42, the input voltage of the ultraviolet light emitting unit 422 in the light receiving unit 42, and the voltage of the fire signal line 3 connected to the light receiving unit 42. Time flows to the right. As in Figure 4, the crest values ​​are shown to be the same in Figure 6, but Figure 6 also shows the timing of the voltages, and the values ​​of each voltage will generally be different.

[0026] The light-receiving unit 42 periodically raises the voltage on the synchronization line 43. In the light-transmitting unit 41, (a) the rising of the voltage on the synchronization line 43 triggers a one-shot circuit (not shown) to operate, applying a voltage to the infrared light-emitting unit 411 for a predetermined period. (b) The infrared light-emitting unit 411, to which voltage has been applied, emits smoke detection infrared light IR, which is received by the infrared light-receiving unit 421 of the light-receiving unit 42, causing the output voltage of the infrared light-receiving unit 421 to increase. (c) In the light-receiving unit 42, the voltage applied to the ultraviolet light-emitting unit 422 increases as the output voltage of the infrared light-receiving unit 421 rises above a threshold. (d) When the predetermined period ends and the voltage applied to the infrared light-emitting unit 411 in the light-transmitting unit 41 drops, the smoke detection infrared light IR goes out, and the output voltage of the infrared light-receiving unit 421 in the light-receiving unit 42 drops. (e) When the output voltage of the infrared light receiving unit 421 drops, the light receiving unit 42 reduces the voltage applied to the ultraviolet light emitting unit 422. As a result, when the infrared light IR for smoke detection between the light transmitting unit 41 and the light receiving unit 42 is not blocked, the ultraviolet light emitting unit 422 emits sterilization ultraviolet light UV in synchronization with the light emission period of the infrared light emitting unit 411.

[0027] If the path between the light-transmitting unit 41 and the light-receiving unit 42 is blocked by smoke or the like, the following occurs: (a1) The rising edge of the voltage applied to the synchronization line 43 by the light-receiving unit 42 triggers the activation of a one-shot circuit (not shown) in the light-transmitting unit 41, which applies a voltage to the infrared light-emitting unit 411 for a predetermined period of time. (f1) (g1) In the light-receiving unit 42, after the rising edge of the voltage on the synchronization line 43, the smoke detection infrared light IR does not reach the infrared light-receiving unit 421, so smoke is detected and the fire signal line 3 is short-circuited. This notifies the P-type receiver 2 that the fire detector 4 has detected smoke. Furthermore, because the infrared light-receiving unit 421 does not generate an output voltage exceeding the threshold, no voltage is applied to the ultraviolet light-emitting unit 422.

[0028] If a person H blocks the smoke detection infrared light IR between the light-transmitting unit 41 and the light-receiving unit 42 due to an inspection operation or the like, the infrared receiving unit 421 does not generate an output voltage exceeding the threshold, as described above, and voltage is not applied to the ultraviolet light-emitting unit 422, so the sterilization ultraviolet light UV is not emitted. Therefore, the sterilization ultraviolet light UV is not irradiated onto the person H. In the second embodiment, as in the first embodiment, the sterilization ultraviolet light UV is emitted in a direction along the optical axis of the smoke detection infrared light IR, albeit in the opposite direction. Therefore, although the emission positions of the smoke detection infrared light IR and the sterilization ultraviolet light UV are separated, the sterilization ultraviolet light UV is irradiated near the smoke detection infrared light IR. Furthermore, since the ultraviolet light-emitting unit 422 is located above the infrared receiving unit 421 when the fire detector 4 is installed, the sterilization ultraviolet light UV is located above the smoke detection infrared light IR, further reducing the possibility of it being directly irradiated onto the person H.

[0029] In the second embodiment, since the light receiving unit 42 has the ultraviolet light emitting unit 422, it is not necessary to send information about the blocking of the smoke detection infrared light IR to the light transmitting unit 41. Therefore, the fire detector 4 can be obtained by simply changing the design of a conventional photoelectric separation type fire detector slightly. Also, in the second embodiment, the light receiving unit 42 emits the sterilization ultraviolet light UV in response to receiving the smoke detection infrared light IR. Therefore, when the smoke detection infrared light IR is blocked by a person H or the like, the sterilization ultraviolet light UV is quickly turned off.

[0030] <Modification> In the second embodiment, the light receiving unit 42 emits the sterilization ultraviolet light UV when the received light exceeds the threshold value of the smoke detection infrared light IR. However, the sterilization ultraviolet light UV may be emitted for a longer period than the reception of the smoke detection infrared light IR. Furthermore, the sterilization ultraviolet light UV may be continuously emitted, and the sterilization ultraviolet light UV may be turned off when the infrared light receiving unit stops receiving the smoke detection infrared light IR. Alternatively, the sterilization ultraviolet light UV may be emitted for a predetermined period triggered by the time when the infrared light receiving unit stops receiving the smoke detection infrared light IR, and the emission timing may be staggered as in the first embodiment to prevent simultaneous emission, thereby suppressing peak power consumption. [Example]

[0031] FIG. 7 shows a fire detector 5 in an R-type fire detection system according to a third embodiment of the present invention. The fire detection system including the fire detector 1 of the first embodiment shown in FIGS. 1 and 2 and the installation state of the fire detector 1 are the same in the third embodiment. The ultraviolet light-emitting unit 512 of the third embodiment is provided in the light-transmitting unit 51, as in the first embodiment. On the other hand, the third embodiment differs from the first embodiment in that it is an R-type fire detection system. The fire detector 5 emits infrared light IR for smoke detection from the infrared light-emitting unit 511 of the light-transmitting unit 51 toward the infrared light-receiving unit 521 of the light-receiving unit 52. A terminal provided in the light-receiving unit 52 is connected to the R-type receiver 6 via a power supply / signal line 7. The light-transmitting unit 51 is connected to the light-receiving unit 52 via a power supply / signal line 53. Power is supplied from the R-type receiver 6 to the infrared light-emitting unit 511 and ultraviolet light-emitting unit 512 provided in the light-transmitting unit 51 via the power supply / signal line 7, the light-receiving unit 52, and the power supply / signal line 53.

[0032] In the third embodiment, the R-type fire detection system operates as follows with respect to the emission control of the sterilization ultraviolet light UV. (a) In a normal state, the light-transmitting unit 51 applies a voltage to the ultraviolet light-emitting unit 512 to activate the emission of the sterilization ultraviolet light UV. (b) The addresses assigned to the multiple light-receiving units 52 are identified, and communication is performed sequentially from the R-type receiver 6 to confirm the current status. The light-receiving unit 52 performs a detection operation when a confirmation communication for the assigned address is received. (c) In order to detect smoke, the light-receiving unit 52 transmits an emission command for the smoke detection infrared light IR to the power supply signal line 53 at regular time intervals. The light-transmitting unit 51 receives the emission command, applies a voltage to the infrared light-emitting unit 511, causing it to emit light and transmit the smoke detection infrared light IR. (d) In the light-receiving unit 52, the infrared light-receiving unit 521 detects the smoke detection infrared light IR. The light receiving unit 52 then transmits information about the detected output voltage of the infrared light receiving unit 521 to the R-type receiver 6 via the power supply combined signal line 7. The R-type receiver 6 analyzes the received information and determines whether or not to issue a fire alarm. (e) If the output of the smoke detection infrared light IR does not exceed the threshold at the emission timing of the infrared light emitting unit 511, it transmits a command to turn off the sterilization ultraviolet light UV to the power supply combined signal line 53. The light transmitting unit 51 receives the turn-off command and reduces the voltage applied to the ultraviolet light emitting unit 512, turning off the ultraviolet light emitting unit 512. In the third embodiment, communication via the power supply combined signal lines 53 and 7 is performed by digital communication.

[0033] <Modification> The R-type fire detection system may also be configured as a fire detector in which an ultraviolet light emitter is provided in the light receiver, as in Example 2. In this fire detector, as in Example 2, it is not necessary to send information on the blocking of the smoke detection infrared light IR to the light transmitter. Therefore, a fire detector can be obtained by simply slightly modifying the design of a conventional photoelectric separation type fire detector. Furthermore, the R-type fire detection system may also be configured to suppress peak power consumption by shifting the light emission timing of the infrared light emitter and the ultraviolet light emitter.

[0034] In each embodiment, the fire detector is configured so that, when installed, the emission of the sterilizing ultraviolet light UV is above the emission of the luminescent smoke detection infrared light IR. However, as long as the sterilizing ultraviolet light is aligned with the luminescent smoke detection infrared light, it has the effect of preventing irradiation of the human body, regardless of whether or not there is a function to stop the sterilizing ultraviolet light when the smoke detection infrared light is no longer received. Of course, having a function to stop the sterilizing ultraviolet light is more effective in preventing irradiation of the human body, and having the sterilizing ultraviolet light above the luminescent smoke detection infrared light is more effective in preventing irradiation of the human body.

[0035] Furthermore, in order to prevent false alarms, a fire alarm is issued after it is confirmed that the smoke detection infrared light IR has been blocked by the light receiving unit multiple times, and the sterilization ultraviolet light UV is turned off if the smoke detection infrared light IR is blocked even once to prevent adverse effects on the human body, so the determination of a fire and the determination of turning off the sterilization ultraviolet light UV do not necessarily have to be made simultaneously or at the same level. Also, in the above embodiment, an ultraviolet light emitting unit is provided in either the light transmitting unit or the light receiving unit, but an ultraviolet light emitting unit may be provided in both the light transmitting unit and the light receiving unit.

[0036] Furthermore, the specific configuration is not limited to the embodiments, and the present invention includes design changes within the scope of the present invention. Furthermore, the above-described embodiments can be combined by utilizing each other's technology as long as there are no particular contradictions or problems in the purpose, configuration, etc. [Explanation of symbols]

[0037] 1 fire detector, 11 light transmitting unit, 111 infrared light emitting unit, 112 ultraviolet light emitting unit, 113 light emitting power supply, 12 light receiving unit, 121 infrared light receiving unit, 13 synchronization line, 2 P-type receiver, 3 fire signal line, 4 Fire detector, 41 Light transmitting unit, 411 Infrared light emitting unit, 412 Light emitting power supply, 42 Light receiving unit, 421 Infrared light receiving unit, 422 Ultraviolet light emitting unit, 423 Light emitting power supply, 43 Synchronization line, 5 Fire detector, 51 Light transmitting unit, 511 Infrared emitting unit, 512 Ultraviolet emitting unit, 52 Light receiving unit, 521 Infrared receiving unit, 53 Power supply combined signal line, 6 R-type receiver, 7 power and signal line, IR Infrared light for smoke detection, UV Ultraviolet light for sterilization, H Human

Claims

1. A photoelectric separated type fire detector having a light transmitting unit and a light receiving unit, A fire detector characterized by comprising an ultraviolet light emitting unit that emits ultraviolet light for sterilization in a direction along the optical axis of infrared light for smoke detection.

2. A fire detector as described in claim 1, characterized in that, when installed, the ultraviolet light emitting unit is located above an infrared light emitting unit that emits the infrared light for smoke detection or an infrared light receiving unit that receives the infrared light for smoke detection, and the sterilization ultraviolet light is emitted above the infrared light for smoke detection.

3. 3. The fire detector according to claim 1, wherein the light receiving unit stops emitting the sterilization ultraviolet light when the light receiving unit stops receiving the smoke detection infrared light emitted from the light transmitting unit.

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