Smoke detector

Abstract

To provide a smoke sensor having little risk that a user erroneously resets the clocking of the use time of a filter.SOLUTION: The smoke detector 11 includes a light emitting unit 111 and a light receiving unit 112 that are disposed in the sensing area S1, determines whether or not smoke is contained in the air by receiving, with the light receiving unit 112, scattered light that is light emitted by the light emitting unit 111 and scattered by particles contained in the air flowing into the sensing area S1 from the external space, and detects generation of smoke in the external space based on the determination result. The smoke detector 11 includes a filter 114 for capturing and removing dust contained in air flowing from an external space into a detection area S1, a switch 116 for detecting attachment / detachment of the filter 114, and a switch 115 arranged at a position covered with the filter 114. When the switch 115 is pressed for a long time in a state in which the filter 114 is detached, the control unit 117 resets the measurement of the use time of the filter.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to smoke sensing technology. [Background technology]

[0002] 2. Description of the Related Art There are smoke detectors that detect the generation of smoke in an external space by detecting particles contained in the air that flows into a detection area from the external space.

[0003] For example, a smoke detector known as a photoelectric smoke detector emits light from a light-emitting element into a sensing area, and the scattered light that is scattered by particles in the air within the sensing area is received by a light-receiving element.Based on the intensity of the light received and measured by the light-receiving element, the detector detects particles contained in the air flowing into the sensing area from the external space, thereby detecting the generation of smoke in the external space.

[0004] Patent Document 1 is an example of a patent document disclosing technology related to photoelectric smoke detectors. The photoelectric smoke detector described in Patent Document 1 focuses on the fact that the way the output signal from the light receiving element changes over time differs between when particles other than smoke, such as steam, flow into the smoke detection space (detection area) and when smoke flows into the smoke detection space, and proposes an invention that delays the output signal output from the light receiving element by a predetermined delay time, thereby avoiding the inconvenience of falsely detecting smoke due to the generation of steam, etc. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-61423 Summary of the Invention [Problem to be solved by the invention]

[0006] When dust-containing air flows into the sensing area of ​​a smoke detector, there is a risk that the detector will mistake the dust for smoke particles. For this reason, many smoke detectors are equipped with a filter in the airflow path from the outside space to the sensing area, which has a mesh size that allows smoke to pass through but not dust particles with particle sizes larger than smoke, to capture dust contained in the air.

[0007] As smoke detectors are used, their filters become clogged with trapped dust. If the degree of clogging exceeds a certain limit, there is a risk that the smoke detector will not be able to detect smoke promptly even if it is generated in the external space, as a result of the insufficient air flow from the external space to the detection area.

[0008] Therefore, the filter in a smoke detector is often set to have a usable time that is significantly shorter than the time it takes for the filter to become clogged under normal operating conditions. In such cases, maintenance personnel must replace the filter after starting use and before the usable time expires.

[0009] Some smoke detectors have a function to continuously measure the time that has elapsed since the filter began to be used (hereinafter referred to as "usage time") so that maintenance personnel can always check when the filter should be replaced. Many such smoke detectors have an operator that allows maintenance personnel to reset the usage time that is being measured. When a maintenance personnel performs a specified operation on the operator, the smoke detector resets the usage time that it had been measuring to zero, and then continues to measure the time that has elapsed since the specified operation was performed.

[0010] Hereinafter, the operator with which the maintenance person resets the time count of the filter's usage time will be referred to as a "reset button" for convenience, but the type of operator is not necessarily limited to a button.

[0011] For example, a maintenance worker may accidentally touch the reset button while inspecting or replacing a part other than the filter. As a result, the filter usage time counted by the smoke detector is reset, and the maintenance worker will not know the correct time to replace the filter.

[0012] In view of the above circumstances, the present invention provides a smoke detector that reduces the risk that a user will accidentally reset the timer for the filter's usage time. [Means for solving the problem]

[0013] In order to solve the above problems, the present invention proposes a smoke detector that detects the generation of smoke in an external space by detecting particles contained in air flowing from the external space into a sensing area, the smoke detector comprising: a removable filter that is arranged in the flow path of the air flowing into the sensing area and captures dust contained in the air; an operator that accepts operation by the user, the operator being arranged in a position where the user cannot actually operate it when the filter is attached; and a timing means that measures the elapsed time after the operator accepts a specified operation. [Effects of the Invention]

[0014] According to the present invention, unless the filter is removed for replacement or the like, the operator will not be operated by mistake by the user, and therefore there is little risk that the count of the filter usage time will be reset by mistake. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram showing the configuration of a smoke detection system according to an embodiment; [Figure 2] 1 is a diagram illustrating a configuration of a smoke detector according to an embodiment; [Figure 3] FIG. 2 is a diagram showing the configuration of a computer employed as hardware of a control unit according to an embodiment. [Figure 4]FIG. 2 is a diagram showing the functional configuration of a control unit according to an embodiment. [Figure 5] FIG. 4 is a diagram illustrating a flow of processing performed by a timing unit according to an embodiment. [Figure 6] FIG. 10 is a diagram schematically illustrating the configuration of an example of a smoke detector according to a modified example. [Figure 7] FIG. 10 is a diagram schematically illustrating the configuration of an example of a smoke detector according to a modified example. [Figure 8] FIG. 10 is a diagram schematically illustrating the configuration of an example of a smoke detector according to a modified example. [Figure 9] FIG. 10 is a diagram schematically illustrating the configuration of an example of a smoke detector according to a modified example. [Figure 10] FIG. 10 is a diagram showing the functional configuration of a control unit according to a modified example. [Figure 11] FIG. 10 is a diagram illustrating a flow of processing performed by a timing unit according to a modified example.

[0016] [Embodiment] A smoke detection system 1 according to one embodiment of the present invention will be described below. Fig. 1 is a diagram showing the configuration of the smoke detection system 1. The smoke detection system 1 includes a smoke detector 11 and a host system 12.

[0017] The smoke detector 11 is a device that is placed in a space to be monitored for smoke generation (hereinafter referred to as the "monitored space"), takes in the air in the monitored space, detects smoke if it is contained in the air that has been taken in, and if it detects smoke, sends an alarm of smoke generation to the upper system 12.

[0018] In FIG. 1, the smoke detection system 1 includes one smoke detector 11, but the number of smoke detectors 11 included in the smoke detection system 1 varies depending on the number and size of monitored spaces.

[0019] The host system 12 may be a maintenance terminal device, a monitoring terminal device, a smoke alarm panel, a central monitoring system, etc. The host system 12 and the smoke detector 11 can communicate data with each other via a wired, wireless, or mixed communication medium.

[0020] For example, if the upper system 12 is a maintenance terminal device, a user such as a maintenance worker can temporarily connect the upper system 12 (maintenance terminal device) to the smoke detector 11 wirelessly or via a communication cable when performing maintenance work on the smoke detector 11, and can check the data stored in the smoke detector 11 and the data generated by the smoke detector 11 on the display of the upper system 12 (maintenance terminal device).

[0021] The host system 12 is similar to a host system according to the prior art, and therefore a description thereof will be omitted.

[0022] Fig. 2 is a diagram (viewed from above) that schematically illustrates the configuration of smoke detector 11. Note that Fig. 2 illustrates a state in which the wall covering the top surface of the housing of smoke detector 11 has been removed for convenience in order to show the components arranged within the housing of smoke detector 11 (the same applies to Figs. 6 to 8). Fig. 2(a) schematically illustrates smoke detector 11 in a state in which filter 114 is attached (hereinafter referred to as the "attached state") and cover 1102 is closed (hereinafter referred to as the "closed state"), and Fig. 2(b) schematically illustrates smoke detector 11 in a state in which filter 114 is detached (hereinafter referred to as the "detached state") and cover 1102 is open (hereinafter referred to as the "open state").

[0023] The smoke detector 11 includes a housing 110 , a light emitting unit 111 , a light receiving unit 112 , a fan 113 , a filter 114 , a switch 115 , a switch 116 , and a control unit 117 .

[0024] 2, the housing 110 has a partition plate 1101 that divides the internal space into a sensing area S1 for sensing smoke and a storage area S2 for storing the control unit 117.

[0025] In addition, the wall portion of the housing 110 that forms the sensing area S1 is provided with an intake port P, which is an opening that functions as an entrance for air to flow from the external space to the internal space, and an exhaust port Q, which is an opening that functions as an exit for air to flow from the internal space to the external space.

[0026] Furthermore, a part of the wall of the housing 110 is an openable / closable cover 1102. An operator opens the cover 1102 to inspect or replace the internal components of the smoke detector 11. In the example of Fig. 2, the air intake P is provided in the cover 1102, but the air intake P may also be provided in a part of the wall of the housing 110 other than the cover 1102.

[0027] The light-emitting unit 111 has, for example, an LED, and emits light from the LED under the control of the control unit 117. The light emitted by the light-emitting unit 111 is light for detecting smoke within the sensing area S1. The light-emitting unit 111 emits light toward the air flow path from the intake port P toward the exhaust port Q. The light-emitting unit 111 is also disposed at a position not facing the light-receiving unit 112 so that the emitted light does not directly enter the light-receiving unit 112.

[0028] The light receiving unit 112 has, for example, a photodiode, and receives a portion of the scattered light that is generated when the light emitted from the light emitting unit 111 is scattered by particles in the sensing area S1, and outputs a light intensity signal indicating the intensity of the received light to the control unit 117.

[0029] The fan 113 operates under the control of the control unit 117, and its rotating blades generate a flow of air that flows from the external space through the intake port P into the sensing area S1 and then out through the exhaust port Q into the external space.

[0030] Filter 114 includes a cylindrical casing and a filter body disposed within the casing. Filter 114 is disposed on the air flow path from intake port P to exhaust port Q, and the filter body captures dust contained in the air flowing from the external space toward sensing area S1, preventing the dust from entering sensing area S1. Cover 1102 is an openable cover that separates the accommodation space (in this case, the space between fan 113 and cover 1102) that accommodates filter 114 from the outside, and plays a role in allowing filter 114 to perform its function by maintaining filter 114 in an attached state when in the closed state.

[0031] Switch 115 (an example of an operator) is an operator that accepts a predetermined operation by the user to reset the measurement of the filter usage time. Switch 115 is disposed in the accommodation space that accommodates filter 114 (in this case, the space between fan 113 and cover 1102). Switch 115 is also disposed in a position that is covered by filter 114 (filter body).

[0032] Switch 115 has button 1151 biased outward (to the right in the example of FIG. 2). Switch 115 outputs an ON signal to control unit 117 while button 1151 is pressed by the user, and outputs an OFF signal to control unit 117 while button 1151 is not pressed by the user. Hereinafter, the ON signal and the OFF signal are collectively referred to as operation signals.

[0033] Switch 116 (an example of an attachment / detachment detection means) is a component that serves to detect attachment / detachment of filter 114, i.e., the attached and detached states. Switch 116 has button 1161 that is biased toward filter 114 (downward in the example of FIG. 2). Switch 116 outputs an attachment signal to control unit 117 while filter 114 is in an attached state and button 1161 is pressed, and outputs a detachment signal to control unit 117 while filter 114 is in a detached state and button 1161 is not pressed. Hereinafter, the attachment signal and detachment signal will be collectively referred to as attachment / detachment signals.

[0034] The control unit 117 is a device that controls the operation of the smoke detector 11. The hardware of the control unit 117 is, for example, a computer, and the control unit 117 is realized by the computer performing processing in accordance with a program for the control unit 117.

[0035] 3 is a diagram showing the configuration of a computer 10 employed as hardware for the control unit 117. The computer 10 includes a processor 101 that performs various data processing, a memory 102 that stores various data, an input / output interface 103 that exchanges signals with components such as the light-emitting unit 111 of the smoke detector 11, and a communication interface 104 that exchanges data with an external device (in this case, the host system 12).

[0036] Fig. 4 is a diagram showing the functional configuration of control unit 117. That is, control unit 117 including the components shown in Fig. 4 is realized by computer 10 performing processing in accordance with a program for control unit 117. The functional components included in control unit 117 will be described below.

[0037] The light emission instruction means 1171 instructs the light emitting unit 111 to emit light. The light emission instruction means 1171 instructs the light emitting unit 111 to emit light, for example, every time a predetermined time elapses while the smoke detector 11 is in operation.

[0038] The light intensity signal acquiring means 1172 acquires the light intensity signal output from the light receiving unit 112 .

[0039] The smoke determination means 1173 determines whether or not smoke is present in the air around the smoke detector 11 by determining whether or not the light intensity indicated by the light intensity signal acquired by the light intensity signal acquisition means 1172 satisfies a predetermined condition for smoke detection. The predetermined condition for smoke detection is, for example, a condition in which the light intensity signal remains within a reference range indicating the presence of smoke for a predetermined period of time or more.

[0040] When the smoke determination means 1173 determines that smoke is present, it generates smoke generation notification data that notifies the occurrence of smoke. The smoke generation notification data generated by the smoke determination means 1173 is transmitted to the upper system 12 by the communication means 1177.

[0041] The light emitting instruction means 1171, the light emitting unit 111, the light receiving unit 112, the light intensity signal acquiring means 1172, and the smoke determining means 1173 constitute a sensing means that senses particles in the air within the sensing area S1 and detects smoke based on the sensing results.

[0042] The operation signal acquiring means 1174 acquires an operation signal from the switch 115. The attachment / detachment signal acquiring means 1175 acquires an attachment / detachment signal from the switch .

[0043] The timing means 1176 continuously measures the elapsed time since the time when a predetermined operation for resetting the switch 115 is performed based on a clock signal generated by a clock provided in the processor 101, as the usage time of the filter, and generates usage time data indicating the measured usage time.

[0044] The communication means 1177 transmits and receives various data to and from the host system 12. For example, as described above, the communication means 1177 transmits smoke generation notification data generated by the smoke determination means 1173 to the host system 12. In addition, the communication means 1177 transmits the latest usage time data generated by the timing means 1176 to the host system 12 in response to a request from the host system 12, for example.

[0045] For example, if the upper system 12 is a central monitoring system, a user (e.g., an administrator of the smoke detection system 1) can check the smoke occurrence notification data sent from the smoke detector 11 to the central monitoring system on a display or the like of the central monitoring system, and thereby know that there is a high possibility that a fire has occurred in the monitored space where the smoke detector 11 is located.

[0046] Furthermore, if the upper system 12 is a maintenance terminal device, a user (for example, a maintenance person for the smoke detection system 1) can easily know when to replace the filter 114 by checking the filter usage time data received from the smoke detector 11 by the maintenance terminal device temporarily connected to the smoke detector 11 during maintenance work on the display of the maintenance terminal device, etc.

[0047] As described above, the timer 1176 continuously measures, as the usage time of the filter, the time that has elapsed since the time when a predetermined operation for resetting was performed on the switch 115. The predetermined operation for resetting may be any operation that is unlikely to be performed unintentionally by the user, such as, for example, an operation of continuously pressing the button 1151 for a predetermined time (e.g., 3 seconds) or more (long press), or an operation of pressing the button 1151 twice within a predetermined time (e.g., 1 second) (double press).

[0048] In this embodiment, in order to further reduce the risk of the user unintentionally resetting the counting of the filter usage time, when a predetermined reset operation is performed on switch 115 while switch 116 (an example of an attachment / detachment detection means) detects that filter 114 has been removed, timing means 1176 resets the counting of the filter usage time and counts the elapsed time thereafter as a new filter usage time.

[0049] 5 is a diagram illustrating a flow of processing performed by the timing means 1176 when the user operates the switch 115 and the operation signal acquiring means 1174 starts acquiring an ON signal from the switch 115. However, the flow in FIG. 5 illustrates a case where the predetermined operation for resetting is a long press.

[0050] When the timing means 1176 detects that the operation signal continuously received from the switch 115 via the operation signal acquisition means 1174 has changed from an OFF signal to an ON signal, it first determines whether the detachment signal continuously received from the switch 116 via the detachment signal acquisition means 1175 is a detachment signal (step S101).

[0051] If the filter 114 is not removed, the switch 116 outputs an arrival signal. In this case, the timer 1176 determines in step S101 that it has not received a removal signal (step S101; No), and ends the series of processes shown in FIG.

[0052] On the other hand, when the filter 114 is removed, the switch 116 outputs a disconnection signal. In this case, the timing means 1176 determines in step S101 that it has received the disconnection signal (step S101; Yes). In this case, the timing means 1176 determines whether the operation signal received from the switch 115 via the operation signal acquisition means 1174 is an ON signal (step S102).

[0053] If the user has released his / her finger from button 1151 of switch 115 at that time, timing means 1176 determines in step S102 that an ON signal has not been received (step S102; No), and ends the series of processes shown in FIG.

[0054] On the other hand, if the user continues to press the button 1151 of the switch 115 at that time, the switch 115 outputs an ON signal. In this case, the timer 1176 determines in step S102 that it has received an ON signal (step S102; Yes). In this case, the timer 1176 determines whether or not a predetermined time has elapsed from the start of the process according to the flow of FIG. 5, that is, from the timing when the operation signal changed from an OFF signal to an ON signal (step S103). Here, the predetermined time is the time (for example, 2 seconds) during which the button 1151 is continuously pressed for resetting.

[0055] If it is determined in step S103 that the predetermined time has not elapsed (step S103; No), the timer 1176 repeats the determination in step S103 at sufficiently short time intervals. On the other hand, if it is determined in step S103 that the predetermined time has elapsed (step S103; Yes), the timer 1176 resets the filter usage time, which it has been continuously counting, to zero (step S104), and ends the series of processes shown in FIG.

[0056] According to the above-described smoke detection system 1, the inconvenience of the user accidentally touching the switch 115 and unintentionally resetting the filter usage time that the smoke detector 11 continuously measures is unlikely to occur.

[0057] [Variations] The above-described embodiment is a specific example of the present invention, and various modifications are possible within the scope of the technical concept of the present invention. Examples of such modifications are shown below. Note that two or more of the following modifications may be combined as appropriate.

[0058] (1) In the above-described embodiment, the switch 115 is disposed in a position where it is covered by the filter 114 (filter body). Alternatively, the switch 115 may be disposed in a position where it is not covered by the filter 114.

[0059] 7 is a diagram schematically illustrating an example configuration of smoke detector 11 in which switch 115 is not covered by filter 114 but is arranged within the accommodation space that accommodates filter 114. Since the accommodation space in which filter 114 is accommodated is usually small, if switch 115 is arranged within the accommodation space, the user cannot actually operate switch 115 while filter 114 is attached. Therefore, it is unlikely that the user will accidentally touch switch 115 and reset the filter usage time.

[0060] In the smoke detector 11 shown in Figures 2 and 7, the switch 115 is disposed within the accommodation space that accommodates the filter 114. The switch 115 may be disposed outside the accommodation space that accommodates the filter 114, as long as the switch 115 is disposed in a position that prevents the user from substantially operating the switch 115 when the filter 114 is attached. Figure 8 is a diagram schematically illustrating an example configuration of a smoke detector 11 in which the switch 115 is disposed outside the accommodation space that accommodates the filter 114. In the smoke detector 11 of Figure 8, the switch 115 is disposed in a position that allows the user to operate the switch 115 when the cover 1102 is open, the filter 114 is removed, and the fan 113 is also removed. Even in the smoke detector 11 configured as in Figure 8, the user is less likely to unintentionally reset the usage time of the filter.

[0061] (2) In the above-described embodiment, smoke detector 11 does not reset the filter usage time even if a predetermined operation is performed on switch 115 unless switch 116 outputs a detachment signal. Alternatively, smoke detector 11 may reset the filter usage time in response to only the operation signal output by switch 115, without taking into account the detachment signal output by switch 116. Even in this case, as long as the user cannot substantially operate switch 115 unless filter 114 is detached, the inconvenience of the user unintentionally touching switch 115 and resetting the filter usage time is unlikely to occur.

[0062] (3) In the above-described embodiment, the attachment or detachment of the filter 114 is directly detected by the switch 116. Alternatively, a configuration may be adopted in which the attachment or detachment of the filter 114 is indirectly detected.

[0063] Fig. 6 is a diagram schematically illustrating the configuration of an example of a smoke detector 11 according to such a modified example. Smoke detector 11 shown in Fig. 6 differs from smoke detector 11 according to the above-described embodiment in that switch 116 does not directly detect attachment or detachment of filter 114, but rather indirectly detects attachment or detachment of filter 114 by detecting opening or closing of cover 1102 that covers filter 114.

[0064] That is, in this modified example, button 1161 of switch 116 is biased in a direction toward cover 1102. Then, while cover 1102 is in a closed state and button 1161 is pressed, switch 116 outputs an on signal to control unit 117 indicating that filter 114 is being securely held in a predetermined position by cover 1102. On the other hand, while cover 1102 is in an open state and button 1161 is not pressed, switch 116 outputs an off signal to control unit 117 indicating that filter 114 is not being held in a predetermined position by cover 1102 and that filter 114 may have come out of its predetermined position.

[0065] In other words, in this modified example, switch 116 (an example of an attachment / detachment detection means) detects the open state of cover 1102 as the state in which filter 114 is removed, and detects the closed state of cover 1102 as the state in which filter 114 is attached.

[0066] (4) In the above-described embodiment, the switch 116 is used as the attachment / detachment detection means for detecting the attachment / detachment of the filter 114. The type of attachment / detachment detection means for detecting the attachment / detachment of the filter 114 is not limited to a switch. For example, an object detection sensor using light may be adopted as the attachment / detachment detection means for detecting the attachment / detachment of the filter 114.

[0067] (5) In the above-described embodiment, the operator (switch 115) that accepts a predetermined operation for resetting by the user is a physical operator (an operator having a physically moving part), but it may also be a virtual operator, such as a button displayed on a display.

[0068] (6) In the above-described embodiment, the filter usage time is reset when the user performs a predetermined operation on switch 115. Alternatively, smoke detector 11 may be configured to reset the filter usage time when switch 116 detects that filter 114 has changed from a detached state to an attached state.

[0069] FIG. 9 is a diagram schematically illustrating an example configuration of a smoke detector 11 according to this modification. FIG. 9(a) is a diagram of the smoke detector 11 as viewed from the side. As shown in FIG. 9(a), the smoke detector 11 according to this modification has an openable cover 1102 arranged to cover the top surface of the housing 110. FIGS. 9(b) and 9(c) are top views of the smoke detector 11 with the cover 1102 open. For convenience, the cover 1102 is omitted from FIGS. 9(b) and 9(c). FIG. 9(b) shows a state in which the filter 114 is attached, and FIG. 9(c) shows a state in which the filter 114 is removed. Furthermore, the host system 12 illustrated in FIG. 2 and the like is omitted from FIG. 9.

[0070] In this modification, the user can inspect the components inside the housing 110 with the cover 1102 open, without removing the filter 114. Therefore, the filter 114 is attached to and detached from the smoke detector 11 only when the filter needs to be replaced.

[0071] With the cover 1102 open, the user can remove the old filter 114 from the smoke detector 11 by pulling out the filter 114 upward (the direction of arrow X in FIG. 9(a) or toward the user in FIG. 9(b)). Then, the user can attach a new filter 114 to the smoke detector 11 by inserting the filter 114 in the opposite direction.

[0072] As shown in Figures 9(b) and 9(c), the smoke sensor 11 according to this modification does not include the switch 115. Figure 10 is a diagram showing the functional configuration of the control unit 117 included in the smoke sensor 11 according to this modification. In this modification, the control unit 117 does not include the operation signal acquisition means 1174.

[0073] 11 is a diagram illustrating an example of a processing flow performed by the timing means 1176 included in the control unit 117 according to this modification. The timing means 1176 performs processing according to the flow shown in FIG. 11 when the attachment / detachment signal output from the switch 116 and acquired by the attachment / detachment signal acquisition means 1175 changes.

[0074] When the timing means 1176 detects a change in the detachment signal, it determines whether the detachment signal has changed from an attached signal to a detached signal, or whether the detached signal has changed to an attached signal (step S201).

[0075] When the user removes the old filter 114 from the smoke detector 11, the detachment signal changes from the attached signal to the detached signal. In this case, the timing means 1176 determines that the detachment signal has changed from the attached signal to the detached signal (step S201; "1") and stops timing the filter usage time (step S202). Thereafter, the timing means 1176 ends the series of processes shown in FIG. 11.

[0076] When the user attaches a new filter 114 to the smoke detector 11, the detachment signal changes from a detached signal to an attached signal. In this case, the timing means 1176 determines that the detachment signal has changed from a detached signal to an attached signal (step S201; "2"), resets the filter usage time to zero (step S203), and resumes timing the filter usage time (step S204). That is, the timing means 1176 measures the elapsed time after the switch 116 (an example of an attachment / detachment detection means) detects that the filter 114 has changed from a detached state to an attached state. Thereafter, the timing means 1176 ends the series of processes shown in FIG. 11.

[0077] In smoke detector 11 according to this modification, the filter usage time is not reset unless the user attaches filter 114 to smoke detector 11 from which filter 114 has been removed. Therefore, the inconvenience of the user unintentionally resetting the filter usage time is unlikely to occur.

[0078] (7) In the above-described embodiment, the hardware of the control unit 117 is a computer. However, the control unit 117 may be configured as a dedicated device having an integrated circuit such as an ASIC or FPGA. [Explanation of symbols]

[0079] 1...smoke detection system, 10...computer, 11...smoke detector, 12...host system, 101...processor, 102...memory, 103...input / output interface, 104...communication interface, 110...housing, 111...light-emitting unit, 112...light-receiving unit, 113...fan, 114...filter, 115...switch, 116...switch, 117...control unit, 1101...partition plate, 1102...cover, 1151...button, 1161...button, 1171...light-emitting instruction means, 1172...light intensity signal acquisition means, 1173...smoke detection means, 1174...operation signal acquisition means, 1175...attachment / detachment signal acquisition means, 1176...timekeeping means, 1177...communication means.

Claims

[Claim 1] A smoke detector that detects the generation of smoke in an external space by detecting particles contained in air flowing into a sensing area from an external space, a removable filter disposed in a flow path of air flowing into the sensing area and configured to capture dust contained in the air; a detachment detection means for detecting the attachment or detachment of the filter; a timer that stops timing when the filter removal detection means detects removal of the filter; A smoke detector equipped with:

Images