Light extinction type / reflection type smoke sensor, and failure determination method therefor

Abstract

To enable further reliable determination of a failure of disabling a function of normally detecting the presence of smoke and sensing fire due to influence of a reflective obstacle, ambient light or the like causing non-signal light during an operation.SOLUTION: A light extinction type / reflection type smoke sensor 1 in which a transmitting / receiving device 10 comprising a light transmitting part 14 and a light receiving part 16 is installed in a monitoring space 11 so as to be opposed to a reflector 12 comprises: a correlation determination unit 46 for determining correlation between the light transmission amount of transmission light signal light transmitted from the light transmitting part 14, and a receiving light amount of light received by the light receiving part 16; and a failure determination unit 48 for, if the correlation between the light transmission amount and the light receiving amount that are determined by the correlation determination unit 46 satisfies a predetermined failure determination condition, determining a failure.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a dimming reflective smoke detector and a fault determination method thereof, which detects a fire by installing a light-transmitting unit and a light-receiving unit on one side of a monitored space and installing a reflector opposite them on the other side of the monitored space, transmitting light from the light-transmitting unit to the reflector, reflecting it off the reflector, and receiving it at the light-receiving unit to detect the attenuation of light propagating back and forth through the monitored space, and detecting the presence of a predetermined concentration of smoke in the monitored space due to a fire or the like. [Background technology]

[0002] Conventionally, dimming type separated smoke detectors include opposed dimming type separated smoke detectors in which the transmitter and receiver are arranged opposite each other, and reflective dimming type separated smoke detectors in which the transmitter and receiver are integrated and a reflector are arranged opposite each other (hereinafter referred to as "dimming type reflective smoke detectors"), in which a retroreflector, which has the property of reflecting incident light generally in the direction of incidence, is used for the reflector.

[0003] In addition, when a dimming reflective smoke detector is installed in a monitored space and operation begins, the optical axis is adjusted in advance by manual adjustment using a viewfinder based on building drawings or visual inspection, or automatically by controlling an actuator, etc., while checking the light receiving level (amount of light received) with an indicator mounted on the transmitter / receiver, and initial settings are made to obtain an appropriate initial amount of light received in order to properly detect the presence of smoke in the monitored space (Patent Documents 1 and 2).

[0004] In addition, if a reflective obstacle other than a reflector, such as a beam or duct, is present within or near the irradiation area of ​​the light transmitted from the light transmitting unit of the light transmitting / receiving device, the amount of light received by the light receiving unit of the light transmitting / receiving device will be affected by the light reflected from the reflective obstacle, and depending on the location of the smoke, it may not be possible to properly detect the presence of smoke or the smoke concentration. For this reason, the irradiation area of ​​the light transmitted from the light transmitting unit of the light transmitting / receiving device or the area near it is set as an obstacle installation restriction area, and a dimming reflective smoke detector is installed so that reflective obstacles such as beams or ducts do not exist within the installation restriction area. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-059784 A [Patent Document 2] JP 2019-096270 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, even if initial settings are made to avoid or mitigate the effects of reflective obstacles and operation is then started, reflective obstacles may come into existence within the installation restriction area during operation due to building expansion or renovation, etc., and the system may become affected by the reflective obstacle. Although it is possible to detect a change in the amount of light received by the light receiving unit, it is not possible to determine whether this change is due to the effect of a reflective obstacle, and it is difficult to determine that the effect of a reflective obstacle is an obstacle.

[0007] In addition, even if the building is expanded or renovated and becomes subject to disturbance light such as sunlight or lighting depending on the season or time of day, it is possible to detect a change in the amount of light received by the light receiving unit, but it is not possible to determine whether this change is due to disturbance light or not, making it difficult to determine that the disturbance light is causing a problem.

[0008] The present invention aims to provide a dimming reflective smoke detector and a method for determining a fault therein that can more reliably determine a fault that prevents the detector from normally detecting the presence of smoke and therefore fire during operation due to the influence of reflective obstacles that cause non-signal light or external light disturbances, etc. [Means for solving the problem]

[0009] (Dimmable reflective smoke detector) The present invention provides a dimming reflective smoke detector that detects the presence of smoke in the monitored space by installing a light transmitter / receiver having an integrated light transmitter and receiver in one side of a monitored space and installing a reflector in the other side of the monitored space opposite the light transmitter / receiver, transmitting a light transmission signal from the light transmitter to the reflector, detecting attenuation of a light reception signal received by the light receiver after the light transmission signal is reflected by the reflector, and detecting the presence of smoke in the monitored space and detecting a fire, a correlation determination unit that determines a correlation between an amount of transmitted signal light and an amount of received light received by a light receiving unit; a fault determination unit that determines that a fault has occurred when the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit satisfies a predetermined fault determination condition; The present invention is characterized in that:

[0010] (Fault determination by comparison with standard correlation) the correlation determination unit registers in advance as a reference correlation a correlation between the amount of transmitted light and the amount of received light determined in a state in which the amount of received light is not affected by received non-signal light other than the received signal light received by the light receiving unit; The fault determining section compares the correlation between the amount of transmitted light and the amount of received light determined by the correlation determining section with a reference correlation, and determines that a fault has occurred if a predetermined fault determination condition is satisfied.

[0011] (Fault determination by comparison with standard light reception level) The correlation determination unit further registers in advance an amount of received light detected in a state where the amount of received light is not affected by the received non-signal light as a reference amount of received light, The fault determination unit compares the correlation between the amount of light sent and the amount of light received determined by the correlation determination unit with a reference correlation, and also compares the detected amount of received light with a reference amount of received light, and determines that a fault has occurred if specified fault determination conditions are met.

[0012] (How to determine disability) The fault determination unit When the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit deviates from the reference correlation by more than a predetermined range, it is determined that a fault has occurred due to the influence of non-signal light; When the correlation between the amount of light sent and the amount of light received determined by the correlation determination unit matches the reference correlation and the detected amount of received light is a predetermined value that exceeds the reference amount of received light, it is determined that a fault has occurred due to the influence of ambient light.

[0013] (Timing of fault determination) The fault determining unit performs processing to determine a fault when a change in the amount of received light exceeds a predetermined value during operation and / or at predetermined intervals.

[0014] (Fault determination based on proportionality factor) the correlation determination unit applies a proportional relationship between the amount of light transmitted by the transmission signal light and the amount of light received by the light receiving unit as the correlation, and performs a determination based on a proportional coefficient of the proportional relationship; The fault determining section determines that a fault has occurred when the proportionality coefficient determined by the correlation determining section satisfies a predetermined fault determination condition.

[0015] (Determination method based on proportionality coefficient) the correlation determination unit registers in advance a proportionality coefficient determined in a state not influenced by received non-signal light other than the received signal light received by the light receiving unit as a reference proportionality coefficient and also registers in advance the amount of received light as a reference amount of received light; The fault determination unit After the correlation determination unit determines that the amount of light transmitted and the amount of light received are in a proportional relationship, when the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit deviates from the reference correlation by more than a predetermined range and the amount of received light detected when the amount of transmitted light is set to zero is equal to or less than a predetermined value, it is determined that an obstacle is being caused by the influence of a reflective obstacle; if the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit deviates from the reference correlation beyond a predetermined range and the amount of received light detected when the amount of transmitted light is set to zero exceeds a predetermined value, it is determined that an obstacle is present, that is, that the obstacle is influenced by a reflective obstacle and that the obstacle is influenced by disturbance light; When the correlation between the amount of light sent and the amount of light received determined by the correlation determination unit matches the reference correlation and the detected amount of received light is a predetermined value that exceeds the reference amount of received light, it is determined that a fault has occurred due to the influence of ambient light.

[0016] (Fire watch operations resumed) The fault determination unit After the correlation determination unit determines that the amount of light transmitted and the amount of light received are not proportional, If the amount of received light detected when the amount of transmitted light is set to zero exceeds a predetermined value, it is determined that a fault is occurring due to the influence of non-signal light; If the amount of received light detected when the amount of transmitted light is set to zero is equal to or less than a predetermined value, the fault determination operation is cancelled and the operation is changed so that the dimming reflective smoke detector performs a fire monitoring operation.

[0017] (Method of determining faults in dimming reflective smoke detectors) The present invention provides a method for determining a fault in a dimming reflective smoke detector, which comprises installing a light transmitter / receiver having an integrated light transmitter and receiver in one side of a monitored space and installing a reflector in the other side of the monitored space opposite the light transmitter / receiver, transmitting a light transmission signal from the light transmitter to the reflector, detecting attenuation of a light reception signal received by the light receiver after the light transmission signal is reflected by the reflector, and detecting the presence of smoke in the monitored space to detect a fire, comprising: A correlation determination unit determines a correlation between the amount of light transmitted from the transmission signal light and the amount of light received by the light receiving unit; The fault determining section determines that a fault has occurred when the correlation between the amount of transmitted light and the amount of received light determined by the correlation determining section satisfies a predetermined fault determination condition.

[0018] Other features of the invention relating to the method for determining a fault in a dimming reflective smoke detector are similar to those of the invention relating to the dimming reflective smoke detector described above, and therefore will not be described here. Effect of the Invention

[0019] (Effects of dimming reflective smoke detectors) The present invention is a dimming type reflective smoke detector that detects the presence of smoke in the monitored space by installing a light transmitter / receiver having an integrated light transmitter / receiver in one side of the monitored space and installing a reflector on the other side of the monitored space opposite the light transmitter / receiver, transmitting light transmission signal light from the light transmitter to the reflector, and detecting the attenuation of light reception signal light received by the light receiver after the light transmission signal light is reflected by the reflector.The present invention is a dimming type reflective smoke detector that detects a fire by detecting the presence of smoke in the monitored space and detecting a fire.The present invention is provided with a correlation determination unit that determines the correlation between the amount of light transmitted and the amount of light received by the light receiver, and a fault determination unit that determines that a fault has occurred if the correlation between the amount of light transmitted and the amount of light received by the correlation determination unit satisfies specified fault determination conditions.This makes it possible to more reliably determine faults that prevent the presence of smoke from being detected normally and a fire from being detected due to the influence of reflective obstacles or external light during operation, thereby improving reliability.

[0020] (Effect of fault determination by comparison with standard correlation) In addition, the correlation determination unit pre-registers as a reference correlation the correlation between the amount of light sent and the amount of received light determined in a state where the amount of received light is not influenced by received non-signal light other than the received signal light received by the light receiving unit, and the fault determination unit compares the correlation between the amount of light sent and the amount of received light determined by the correlation determination unit with the reference correlation and determines that a fault has occurred if a specified fault determination condition is satisfied.Therefore, by comparing the correlation between the amount of light sent and the amount of received light determined by the correlation determination unit with the pre-registered reference correlation determined in a state where it is not influenced by reflective obstacles or external light that cause received non-signal light, it is possible to more reliably determine a fault.

[0021] (Effect of fault determination based on comparison with standard light reception level) The correlation determination unit further pre-registers the amount of received light detected when the amount of received light is not affected by the received non-signal light as a reference amount of received light, and the fault determination unit compares the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit with the reference correlation and also compares the detected amount of received light with the reference amount of received light, and determines that a fault has occurred if a specified fault determination condition is satisfied.Therefore, by determining a fault through multiple comparisons, such as comparing the determined correlation between the amount of transmitted light and the amount of received light with the reference correlation and comparing the detected amount of received light with the reference amount of received light, it is possible to more reliably determine a fault.

[0022] (Effect of the method of determining disability) In addition, the fault determination unit determines that a fault has occurred due to the influence of non-signal light when the correlation between the amount of light sent and the amount of light received determined by the correlation determination unit deviates from the reference correlation by more than a specified range, and determines that a fault has occurred due to the influence of disturbance light when the correlation between the amount of light sent and the amount of light received determined by the correlation determination unit matches the reference correlation and the detected amount of received light is a specified value that exceeds the reference amount of received light.This makes it possible to more reliably determine a fault, and by knowing the type of fault determined in more detail, it enables appropriate action to be taken according to the type of fault.

[0023] (Effect of timing of fault determination) The fault determination unit is configured to perform processing to determine a fault when there is a change in the amount of received light that exceeds a predetermined value during operation and / or at a predetermined period, making it possible to determine a fault at appropriate timing during operation.

[0024] (Effect of proportionality factor on fault determination) In addition, the correlation determination unit applies a proportional relationship between the amount of light transmitted and the amount of light received by the light receiving unit as a correlation, and determines the proportional coefficient of the proportional relationship.The fault determination unit determines that a fault has occurred if the proportional coefficient determined by the correlation determination unit satisfies a specified fault determination condition.By applying a proportional relationship as the correlation between the amount of light transmitted and the amount of light received, and making a determination based on the proportional coefficient of the proportional relationship, it is possible to more appropriately and reliably determine that a fault has occurred due to the influence of a reflective obstacle or external disturbance light.

[0025] The reason why a proportional relationship is applied as the correlation between the amount of transmitted light and the amount of received light in this manner and a determination is made based on the proportionality coefficient of the proportional relationship will be explained as follows.

[0026] In the case of a dimming reflective smoke detector, when the light transmitter / receiver and reflector are fixed in an installed state, the amount of light transmitted from the light transmitter section and the amount of light received from the light receiver section, which is reflected by the reflector and received by the light receiver section, are in a proportional relationship. The proportionality coefficient is a constant determined by the light transmission spread angle of the light transmission signal light, the effective area of ​​the reflecting surface of the reflector, the reflection efficiency, the reflected light spread angle of the reflected signal light, the effective area of ​​the light receiving lens of the light receiver section, etc.

[0027] Here, as an example, in the case of using a reflex reflector 60 in which a number of retroreflective elements (corner cubes) 62 are integrated in a two-dimensional array as shown in FIG. 7 as a reflector, it is known that the amount of received signal light received by the light receiving unit in a given installation distance range, specifically, for example, an installation distance range of several tens of meters to 100 meters, is generally inversely proportional to the fourth power of the installation distance, and this is also a factor constituting the proportionality coefficient. In other words, the proportionality coefficient is determined by the type of reflecting object and the distance between the light transmitting / receiving device and the reflector (called the installation distance) in addition to the above. The reflex reflector 60 shown in FIG. 7 is, for example, made of transparent acrylic resin. FIG. 7 (A) shows a reflex reflector, and (B) shows a retroreflective element (corner cube) used in the reflex reflector.

[0028] When a reflective obstacle is located at a predetermined position between the light transmitter / receiver and the reflector, and the reflected non-signal light, which is the transmitted light signal light reflected by the reflective obstacle, affects the amount of light received by the light receiver, there is a proportional relationship between the amount of received non-signal light, which is the transmitted light signal light reflected by the reflective obstacle and received by the light receiver, and the amount of transmitted light signal light transmitted from the light transmitter, but the proportionality coefficient in this case differs from the proportionality coefficient when there is no influence of the reflective obstacle. That is, the factors that determine the proportionality coefficient when there is an influence of the reflective obstacle include at least the distance between the light transmitter / receiver and the reflective obstacle, the area influenced by the reflective obstacle, the reflection efficiency of the reflective obstacle, the reflected light spread angle of the non-signal light reflected from the reflective obstacle, etc., and the proportionality coefficient differs from the proportionality coefficient when there is no influence of the reflective obstacle.

[0029] Furthermore, since the reflection characteristics of the reflective obstacle are different from those of the reflector, generally, the relationship between the amount of received non-signal light received by the light-receiving unit and the distance between the transceiver and the reflective obstacle is different from the relationship with the distance (installation distance) between the transceiver and the reflector. For example, at this time, the amount of received non-signal light received from the reflective obstacle does not have an inverse proportional relationship with the fourth power of the distance between the transceiver and the reflective obstacle. As an example, if the reflective obstacle is a specular reflector having a reflective surface facing the transceiver (perpendicular to the light-emitting optical axis and the light-receiving optical axis), the amount of received non-signal light received from the reflective obstacle is inversely proportional to the square of "twice the distance" between the transceiver and the reflective obstacle. That is, in this case, the amount of received light does not become inversely proportional to the fourth power of the distance.

[0030] Since both the distance between the transceiver and the reflector and the distance between the transceiver and the reflective obstacle affect the proportional coefficient related to the correlation between the light-emitting amount and the light-receiving amount, and moreover, many of the other elements constituting the proportional coefficient are different between the reflector and the reflective obstacle, when the light received by the light-receiving unit is a combination of the received signal light from the reflector and the received non-signal light from the reflective obstacle, or when it is only the received non-signal light from the reflective obstacle, the proportional coefficient related to the correlation (proportional relationship) between the light-emitting amount and the light-receiving amount will be different from the case where the light-receiving unit is receiving only the reflected signal light from the reflector. In addition, in many cases where disturbance light accompanied by temporal fluctuations, specifically, sunlight with fluctuations or blinking illumination light, etc., enters and is received by the light-receiving unit, the light-emitting amount and the light-receiving amount do not have a proportional relationship.

[0031] Therefore, during operation, when evaluating the proportional coefficient as an indication of the correlation between the light-emitting amount of the transmitted signal light and the light-receiving amount of the light received by the light-receiving unit, the proportional coefficient when there is no influence from the reflective obstacle or disturbance light coincides with the reference proportional coefficient, and the proportional coefficient when there is an influence from the reflective obstacle or disturbance light becomes a different proportional coefficient, for example, larger than the reference proportional coefficient. Therefore, by making a determination based on the proportional coefficient, it is possible to determine whether there is an influence from the reflective obstacle or disturbance light, whether there is no influence or a small influence from the reflective obstacle or disturbance light, and it is possible to determine whether there is an influence from the reflective obstacle or disturbance light.

[0032] (Effect of the proportionality-based judgment method) The correlation determination unit pre-registers a proportionality coefficient determined in a state not influenced by received non-signal light other than received signal light received by the light receiving unit as a reference proportionality coefficient and pre-registers the amount of received light as a reference amount of received light, and the fault determination unit determines that there is a fault due to influence of a reflective obstacle when the correlation determination unit determines that the amount of transmitted light and the amount of received light are proportional to each other and, after the correlation determination unit determines that the amount of transmitted light and the amount of received light determined by the correlation determination unit deviates from the reference correlation by more than a predetermined range and the amount of received light detected when the amount of transmitted light is set to zero is equal to or less than a predetermined value, and If the correlation with the amount of received light deviates from the reference correlation by more than a specified range, and if the amount of received light detected when the amount of transmitted light is set to zero exceeds a specified value, it is determined that there is a fault due to the influence of a reflective obstacle and due to the influence of external disturbance light.If the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit matches the reference correlation and the detected amount of received light is a specified value that exceeds the reference amount of received light, it is determined that there is a fault due to the influence of external disturbance light.This allows for more detailed information about the type of fault that has been determined, and makes it possible to take appropriate action according to the type of fault.

[0033] (Effects of resuming fire monitoring operations) The fault determination unit determines that there is a fault due to influence of non-signal light when the amount of received light detected when the amount of transmitted light is set to zero exceeds a predetermined value after the correlation determination unit has determined that the amount of transmitted light and the amount of received light are not proportional, and when the amount of received light detected when the amount of transmitted light is set to zero is equal to or less than a predetermined value, the fault determination operation is canceled and the operation is changed so that the dimming reflective smoke detector performs fire monitoring operation.Therefore, when the factor that causes the amount of transmitted light and the amount of received light to not be proportional is likely to be due to the influence of smoke from a fire rather than external light, it is possible to switch from the fault determination operation to fire monitoring operation, and maintain the reliability of fire monitoring.

[0034] (Effect of fault detection method for dimming reflective smoke detectors) The effects of the invention relating to the method for determining a fault in a dimming reflective type smoke detector are similar to those of the invention relating to the dimming reflective type smoke detector described above, and therefore a description thereof will be omitted. [Brief description of the drawings]

[0035] [Figure 1] FIG. 1 is a conceptual explanatory diagram showing a fire monitoring state in which a light transmitter / receiver and a reflector are installed in a monitored space. [Diagram 2] FIG. 1 is a conceptual diagram illustrating a fire monitoring situation affected by reflective obstacles. [Diagram 3] FIG. 1 is an explanatory diagram showing an embodiment of a dimming reflective smoke detector. [Figure 4] 1 is an explanatory diagram showing a schematic diagram of an optical axis adjustment section of an optical bench having a light transmitting section and a light receiving section integrally formed therewith; [Diagram 5] FIG. 11 is an explanatory diagram showing the relationship between the proportionality coefficient and the reference proportionality coefficient in a normal state and a fault state. [Figure 6] 4 is a flowchart showing a fault determination operation. [Figure 7] This is an explanatory diagram showing a reflex reflector in which retroreflective elements (corner cubes) are integrated in a two-dimensional array. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a light-reducing reflective smoke detector and a method for determining a fault in the same according to the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following preferred embodiments.

[0037] [Basic Concept of the Embodiment] First, a basic concept of the embodiment will be described. The embodiment generally relates to a dimming reflective smoke detector and a fault determination method thereof.

[0038] Here, a "dimming reflective smoke detector" is a detector in which a light transmitter / receiver with an integrated light transmitter and receiver is installed on one side of a monitored space, and a reflector is installed on the other side of the monitored space facing the light transmitter / receiver, a light transmission signal light from the light transmitter is transmitted to the reflector, and the light reception signal light reflected by the reflector is received by the light reception unit, and the attenuation of the received signal light is detected to detect the presence of smoke in the monitored space and detect a fire. In other words, a dimming reflective smoke detector detects a fire by utilizing the attenuation of the light transmission signal light and reflected signal light propagating through the monitored space by smoke generated by a fire and floating in the monitored space. Note that a "dimming reflective smoke detector" is sometimes called a "photoelectric separated smoke detector (reflective type)."

[0039] The "light transmitting unit" transmits the light signal to the reflector, and is a concept including those called "light projecting unit" and "light emitting unit." For example, the light transmitting unit is provided with a light emitting diode that generates the light signal, and the amount of light emitted increases or decreases according to the forward current flowing through the light emitting diode, that is, the amount of light emitted corresponds to the current that drives the light emitting diode to emit light. Note that the light emission drive may be performed intermittently.

[0040] The "light receiving unit" receives reflected signal light reflected by the reflector as received signal light, and in some cases receives non-signal light such as non-signal light reflected from a reflective obstacle other than the reflector as received non-signal light. For example, the light receiving unit includes a photodiode, and the light received by the photodiode (received signal light or received non-signal light) is photoelectrically converted to a received light current, which is amplified by the amplifier and then A / D converted to become received light data. At this time, the "received light amount" is an index of the amount of received light, and corresponds to the "received light signal," the "received light signal level," the "received light data (processing results such as the A / D converted value of the received light signal and its time integral value)," etc. The light receiving process in the light receiving unit may be performed intermittently. If the light emission drive is intermittent, the light receiving process may be performed in synchronization with the intermittent light emission drive.

[0041] In addition, "signal light" refers to light that is transmitted from the light-transmitting unit toward the reflector, reflected by the reflector, received by the light-receiving unit, and attenuated by smoke. The signal light transmitted from the light-transmitting unit is called "transmitted signal light," the signal light reflected by the reflector is called "reflected signal light," and the signal light received by the light-receiving unit is called "received signal light."

[0042] In contrast to "signal light," "non-signal light" refers to light other than signal light; for example, transmitted signal light from a light-transmitting unit that is reflected by a reflective obstacle is called "reflected non-signal light," and reflected non-signal light received by a light-receiving unit is included in "received non-signal light." Additionally, "non-signal light" also includes "disturbance light" received by the light-receiving unit, either directly or by reflection, such as sunlight or illumination light, and "reflected non-signal light" includes disturbance light reflected by reflectors or reflective obstacles, while "received non-signal light" is a concept that includes light received by the light-receiving unit.

[0043] Furthermore, the "amount of light" in the terms "amount of transmitted light," "amount of received light," and "amount of reflected light" refers to the intensity of light and the magnitude of light energy, and includes concepts such as "light intensity" and "light density." Furthermore, a "reflective obstacle" is a reflective object other than the reflector that affects the amount of light received by the light receiving unit, in other words, a reflective object that is not included in a dimming reflective smoke detector, and includes reflective objects such as beams and ducts that exist in the monitored space between the light transmitting / receiving device and the reflector or around the monitored space. Furthermore, when a "reflector" is generally plate-shaped, it is also called a "reflecting plate."

[0044] The dimming reflective smoke detector of this embodiment is equipped with a correlation determination unit and a fault determination unit to more reliably determine faults that prevent the detector from normally detecting the presence of smoke and therefore fire due to the influence of reflective obstacles, external light, etc.

[0045] The "correlation determination unit" determines the correlation between the amount of transmitted signal light and the amount of received light received by the light receiving unit, and the light received by the light receiving unit may include received non-signal light in addition to received signal light. The "fault determination unit" determines that a fault has occurred when the correlation determined by the correlation determination unit satisfies a predetermined fault determination condition.

[0046] The "correlation determination unit" preregisters as a reference correlation the correlation between the amount of transmitted light and the amount of received light determined in a state where the amount of received light is not affected by received non-signal light, i.e., in a state where there is no influence from reflective obstacles or ambient light, and the "fault determination unit" compares the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit with the reference correlation, and determines that a fault has occurred if a predetermined fault determination condition is satisfied. The "state where there is no influence" as used here is a concept that also includes a state where the influence is sufficiently small.

[0047] Furthermore, the "correlation determination unit" pre-registers the amount of received light detected when the amount of received light is not affected by the received non-signal light as a reference amount of received light, and the "fault determination unit" compares the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit with the reference correlation, and also compares the detected amount of received light with the reference amount of received light, and determines that a fault has occurred if specified fault determination conditions are met.

[0048] In addition, as a method of determining a fault, the "fault determination unit" determines that a fault is caused by the influence of non-signal light when the correlation between the amount of light transmitted and the amount of light received determined by the correlation determination unit deviates from the reference correlation by more than a predetermined range, and determines that a fault is caused by the influence of disturbance light when the correlation between the amount of light transmitted and the amount of light received determined by the correlation determination unit matches the reference correlation and the detected amount of light received is a predetermined value exceeding the reference amount of light received. The "match" referred to here includes a case where the correlations roughly match (approximately match) including a predetermined error or the like. In addition, the "fault caused by the influence of non-signal light" refers to a fault when it is possible to identify some influence such as a reflective obstacle or disturbance light that causes the non-signal light, but it is not possible to identify a specific factor such as a reflective obstacle or disturbance light as the cause of the influence, and is a concept that also includes a case where the specific factor causing the influence is either a reflective obstacle or disturbance light, or both a reflective obstacle and disturbance light.

[0049] In addition, the "correlation" between the amount of transmitted signal light determined by the correlation determination unit and the amount of received light received by the light receiving unit is arbitrary, but in the embodiment, for example, a proportional relationship is applied as the correlation, and the determination is made based on the "proportionality coefficient." This utilizes the fact that when the influence of received non-signal light is sufficiently small, that is, when the influence of reflective obstacles, disturbance light, etc. is sufficiently small, the amount of transmitted signal light and the amount of received light received by the light receiving unit exhibit a predetermined proportional relationship.

[0050] In addition, even when the non-signal light reflected from a reflective obstacle affects the amount of light received, the amount of light transmitted and the amount of light received are in a proportional relationship, but the proportionality coefficient in this case is different from the proportionality coefficient when there is no influence of the non-signal light reflected from a reflective obstacle. Note that, for example, in most cases when disturbance light that varies over time is received by the light receiving section, the amount of light transmitted and the amount of light received are not in a proportional relationship.

[0051] Here, "proportional relationship" means a relationship in which the amount of received light increases or decreases (changes) at a constant rate when the amount of transmitted light is increased or decreased (changed). More specifically, it means a direct proportional relationship in which the amount of received light increases at a constant rate when the amount of transmitted light is increased, and when the amount of transmitted light is plotted on the horizontal axis and the amount of received light is plotted on the vertical axis, the relationship between the amount of transmitted light and the amount of received light is a straight line graph with a positive slope, and "proportional coefficient" means the rate at which the amount of received light increases when the amount of transmitted light is increased, and means the slope of the straight line in a graph with the amount of transmitted light on the horizontal axis and the amount of received light on the vertical axis, and is a concept that includes "proportional constant" and "ratio", etc.

[0052] In this way, when "correlation" is defined as a "proportional relationship" and its index (subject to analysis, subject to judgment) is defined as a "proportional coefficient," the "correlation judgment unit" makes a judgment based on the proportional coefficient between the amount of transmitted signal light and the amount of received light received by the light receiving unit as the correlation, and also pre-registers a reference proportional coefficient as a reference correlation and pre-registers the amount of received light as a reference amount of received light.

[0053] In addition, the "fault determination unit" determines that a fault has occurred due to the influence of a reflective obstacle when the correlation between the amount of light transmitted and the amount of received light determined by the correlation determination unit deviates from the reference correlation by more than a predetermined range and the amount of received light detected when the amount of light transmitted is set to zero is equal to or less than a predetermined value, determines that a fault has occurred due to the influence of a reflective obstacle and due to the influence of disturbance light when the correlation between the amount of light transmitted and the amount of received light determined by the correlation determination unit deviates from the reference correlation by more than a predetermined range and the amount of received light detected when the amount of light transmitted is set to zero exceeds a predetermined value, and determines that a fault has occurred due to the influence of disturbance light when the correlation between the amount of light transmitted and the amount of received light determined by the correlation determination unit matches the reference correlation and the detected amount of received light is a predetermined value that exceeds the reference amount of received light.

[0054] In addition, when the correlation determination unit determines that the amount of light transmitted and the amount of light received are not proportional, if the amount of light received detected when the amount of light transmitted is set to zero exceeds a predetermined value, the "fault determination unit" determines that a fault has occurred indicating that the detector is affected by non-signal light if the amount of light received detected when the amount of light transmitted is set to zero is equal to or less than a predetermined value, and cancels the fault determination operation and changes the operation of the dimming reflective smoke detector to perform a fire monitoring operation.

[0055] The fault determination unit performs a process of determining a fault, for example, when the amount of received light changes exceeding a predetermined value during operation and / or at a predetermined cycle. The "cycle" for determining a fault is arbitrary, but may be, for example, once a day.

[0056] A specific embodiment will be described below. In the embodiment, the "light transmitting element of the light transmitting section" is a "light emitting diode (LED)", the "light receiving element of the light receiving section" is a "photodiode (PD)", the "correlation between the amount of transmitted light and the amount of received light" is a "proportional relationship between the amount of transmitted light and the amount of received light", and with regard to the "obstacle", a fault when it is affected by a reflective obstacle is called a "reflective obstacle fault", a fault when it is affected by disturbance light such as sunlight or illumination light is called a "disturbance light fault", and a fault when it is affected by some kind of reflective obstacle or disturbance light that causes non-signal light is called a "non-signal light fault".

[0057] [Specific details of the embodiment] The configuration of the dimming reflective smoke detector of this embodiment will be described in detail below. a. Basic mechanism of dimming reflective smoke detector b. Effect of reflective obstacles c. Configuration of dimming reflective smoke detector d. Disability determination d1. Correlation determination section d2. Judgment based on proportionality coefficient d3. Fault determination section e. Fault detection operation of dimming reflective smoke detector f. Modifications of the present invention

[0058] [a. Basic mechanism of dimming reflective smoke detector] First, the basic mechanism of a dimming reflective smoke detector will be explained with reference to Figure 1, which shows the concept of a fire monitoring state in which a transmitter / receiver and a reflector are installed facing each other across a monitored space.

[0059] As shown in FIG. 1, the dimming reflective smoke detector 1 is composed of a light transmitter / receiver 10 and a reflector 12, and is installed so that the light transmitter / receiver 10 and the reflector 12 face each other across a monitored space 11, which is the area to be monitored for the occurrence of a fire.

[0060] Here, the XYZ directions in FIG. 1 are mutually orthogonal directions, and when the light transmitter / receiver 10 is viewed from the monitored space 11 side, the X direction is the left-right direction, the Y direction is the up-down direction, and the Z direction is the front-back direction. The +X side in the X direction is the right side, the -X side is the left side, the +Y side in the Y direction is the top side, the -Y side is the bottom side, and the +Z side in the Z direction is the front side, and the -Z side is the rear side. As for the direction of rotation of the optical axis centered on the light transmitter / receiver 10, the up-down rotation (vertical rotation) in which the Z axis is superimposed on the Y axis or the Y axis is rotated (rotated) around the Z axis is defined as "vertical rotation" (first rotation direction), and the left-right rotation (horizontal rotation) in which the X axis is superimposed on the Z axis or the Z axis is superimposed on the X axis is defined as "horizontal rotation" (second rotation direction). The vertical rotation axis (first rotation axis) is the X axis, and the horizontal rotation axis (second rotation axis) is the Y axis. Here, the optical axis is considered to pass through the origin of the XYZ coordinates. This also applies to Figs. 2 and 4 which show the embodiment of the present invention.

[0061] The light transmitter / receiver 10 is integrally equipped with a light transmitting section 14 and a light receiving section 16, and transmits light signal light 15a from the light transmitting section 14 toward the reflector 12, at least a part of the light transmitting signal light 15a is reflected by the reflector 12 toward the light receiving section 16 of the light transmitter / receiver 10 as reflected signal light 15b, and at least a part of the reflected signal light 15b is received by the light receiving section 14 of the light transmitter / receiver 10 as received signal light.

[0062] In order to reduce the influence of attenuation due to the spread of the reflected signal light 15b and ensure ease of optical axis alignment, the reflector 12 uses a reflector known as a reflex reflector 60 having retroreflection as shown in FIG. 7 as described above. Here, "retroreflection" refers to the property of reflecting incident light generally in the direction of incidence. In addition, in this embodiment, the reflector 12 having retroreflection has a performance that maintains retroreflection if the angle of incidence of light to the reflector 12 is within a range of, for example, about 10°. However, the extent to which the retroreflection can be exhibited is determined by the assumed installation distance (the installation distance between the light transmitter / receiver 10 and the reflector 12), the extent to which the influence of attenuation due to the spread of the reflected signal light 15b needs to be reduced, and the ease of optical axis alignment needs to be ensured, and the like. In addition, it also depends on whether an installation angle adjustment (variable) mechanism is provided on the reflector 12 side, but in this embodiment, the installation angle adjustment mechanism of the reflector 12 is omitted.

[0063] The light transmitter / receiver 10 is connected to a receiver, which is a control device (not shown), by a signal cable 13, operates by receiving power from the receiver, and detects attenuation in the amount of light received from the light-transmitting unit 14 receiving light-transmitting signal light 15a at a predetermined light-transmitting timing, for example, at a two-second cycle, to detect the presence of smoke in the monitored space 11 and determine whether or not there is a fire. If it is determined that there is a fire, it senses a fire (fire outbreak).

[0064] In the event that a fire occurs and fire smoke 18 is generated in the monitored space 11, the transmitted signal light 15a and the reflected signal light 15b will be attenuated by the smoke, and the amount of received signal light received by the light receiving unit 14 will also decrease (attenuate) compared to before the fire occurred. If the attenuation situation, for example, a change in the amount of received light, more specifically, for example, the amount of decrease (amount of light attenuation) or the rate of decrease (rate of light attenuation), or changes therein over time, meets specified fire determination conditions, it is determined that there is a fire. In this case, for example, a display indicating the occurrence of a fire is displayed on the display unit of the light transmitter / receiver 10, and a fire alert signal is output from the light transmitter / receiver 10 to the receiver to issue a fire alarm.

[0065] [b. Effect of reflective obstacles] Next, the effect of reflective obstacles on a dimming type reflective smoke detector will be explained with reference to Figure 2, which shows the concept of a fire monitoring state affected by reflective obstacles.

[0066] As shown in Figure 2, if a reflective obstacle 20, such as a beam, is present in the monitored space 11 in which the light transmitter / receiver 10 and reflector 12 are arranged opposite each other, part of the transmitted signal light 15a transmitted from the light transmitter 14 will be reflected by the reflective obstacle 20, and in addition to the reflected signal light 15b from the reflector 12, the reflected non-signal light 15c from the reflective obstacle 20 will also be received by the light receiver 16, and the amount of light received by the light receiver 16 will be affected by the reflected non-signal light 15c from the reflective obstacle 20.

[0067] For this reason, if smoke from a fire occurs in the monitored space 11 between the reflective obstacle 20 and the reflector 12, the reflected signal light 15b from the reflector 12 will be attenuated by the smoke from the fire, but the reflected non-signal light 15c from the reflective obstacle 20 will be received by the light-receiving unit 16 without being attenuated by the smoke. As a result, it will be impossible to accurately detect the fire based on the attenuation of the amount of received light due to the smoke from the fire, and this may result in, for example, a late alarm due to a delay in fire detection or a failure to detect the fire, making it impossible to issue an appropriate fire alarm (notification).

[0068] For this reason, when installing the transmitter / receiver 10 and reflector 12 of the dimming reflective smoke detector 1, every effort is made to avoid the presence of reflective obstacles 20 such as beams or ducts inside a building in the monitored space 11, particularly in the irradiation range of the transmitted signal light 15a between the transmitter / receiver 10 and the reflector 12, in order to avoid the influence of the reflective obstacles 20, and the optical axes of each signal light are adjusted and initially set so that a predetermined initial received light amount is obtained that can properly detect the attenuation of the reflected signal light 15b due to fire smoke.

[0069] However, it is anticipated that during operation, changes to the building structure may occur due to renovations or expansions, resulting in the system becoming affected by reflective obstacles, or that the system may become affected by external light such as sunlight or lighting depending on the season or time of day.If the system becomes affected by reflective obstacles or external light during operation, it may no longer be able to properly detect the presence of smoke and sense a fire. Therefore, a system is required that determines if a state in which a fire cannot be detected properly due to the influence of reflective obstacles or external light is a fault and issues an alert.

[0070] Therefore, the dimming reflective smoke detector 1 of the embodiment has a function of determining a state in which a fire cannot be detected normally due to the influence of a reflective obstacle 20 or disturbance light as a fault and notifying the detector.

[0071] [c. Configuration of dimming reflective smoke detector] Next, the configuration of an embodiment of a dimming reflective smoke detector according to the present invention that has a function of determining and reporting a state in which a fire cannot be detected normally due to the influence of a reflective obstacle or disturbance light as an obstacle will be described. In this description, reference will be made to Fig. 3, which shows an embodiment of a dimming reflective smoke detector, and Fig. 4, which shows a schematic diagram of an optical axis adjustment unit of an optical stand that has an integrated light transmitting unit and light receiving unit.

[0072] First, we will explain the configuration of the light transmitter / receiver 10 of the dimming reflective smoke detector 1. As shown in Figure 3, the light transmitter / receiver 10 of the dimming reflective smoke detector 1 has various control functions, which will be described later, as well as an optical unit 22, a control unit 24, a storage unit 26, and an operation display unit 28.

[0073] The optical unit 22 is an integrated unit that integrates the components of the optical system used for smoke detection in the light transmitter / receiver 10, and includes the light transmitter 14, the light receiver 16, an optical stand 30, and an optical axis adjustment unit 32.

[0074] The light sending unit 14 sends a light sending signal light of, for example, 840 to 970 nm, and is composed of a light sending drive unit 34 and a light sending element 36. The specific configuration of the light sending element 36 and the wavelength of the light to be sent are arbitrary, but for example, a light emitting diode (LED) that emits near infrared light is used, and the light emitted by the light emitting diode is collected by a light sending lens (not shown) to send the light sending signal light with a predetermined light sending optical axis. The light sending drive unit 34 is a circuit unit that drives the light sending element 36 to emit light intermittently, for example, at a predetermined light sending timing, and when a light emitting diode is used as the light sending element 36, a forward current is passed through the light emitting diode to drive it to emit light.

[0075] Here, the amount of light transmission Pe of the light transmission signal light transmitted by the light emitted by the light emitting diode is proportional to the forward current flowing through the light emitting diode. In order to determine the presence of a fire and detect a fire (occurrence of a fire) from the attenuation of the amount of light reception signal light received by the light receiving unit 14 due to fire smoke at various assumed installation distances (i.e., the installation distance between the light transmitting / receiving unit 10 and the reflector 12) in the event of a fire, it is necessary to obtain a sufficient and appropriate amount of light reception as the initial amount of light reception signal light by the light receiving unit 16 in a normal state where no fire is occurring, and this initial amount of light reception is set as the reference amount of light reception. During initial setting after installation, the light transmission control unit 42 of the control unit 24 controls the light transmission drive unit 34 to automatically control the forward current flowing through the light emitting diode as the light transmitting element 36, and the amount of light transmission is adjusted so that the light receiving unit 16 obtains this reference amount of light reception.

[0076] The light transmission driver 34 drives the light transmitting element 36 to emit light for a predetermined time at a predetermined cycle, for example, to emit pulses of light to transmit intermittent light, as a predetermined light transmission timing, in response to a control signal from the light transmission control unit 42 of the control unit 24. The cycle of the intermittent light transmission and the light transmission time in one cycle are arbitrary, but for example, the intermittent light transmission is performed by repeating a light transmission time (light transmission pulse) of the order of 100 microseconds in a cycle of 2 seconds.

[0077] The light receiving section 16 receives the signal light reflected by the reflector 12 as a received signal light, and includes a light receiving element 38 and an amplifier section 40 .

[0078] The light receiving element 38 collects the reflected signal light through a light receiving lens (not shown), photoelectrically converts the received signal light, and outputs a light receiving current corresponding to the amount of received signal light Pr as a light receiving signal. The specific type and configuration of the light receiving element 38 are arbitrary, but for example, a photodiode (PD: Photo Diode) that receives light of a wavelength corresponding to the wavelength of the light transmitted by the light transmitting element 36 can be used. The amplifier 40 amplifies the light receiving signal from the light receiving element 38 and outputs it to a light receiving control unit 44 of the control unit 24. Here, the light receiving signal output from the amplifier 40 is proportional to the amount of received signal light Pr received by the light receiving element 38.

[0079] The light transmitting unit 14 and the light receiving unit 16 are fixed on an optical stand 30 of the optical unit 22. The light transmitting unit 14 and the light receiving unit 16 are arranged so that the light transmitting optical axis, which is the direction of light transmission from the light transmitting unit 14, and the light receiving optical axis, which is the direction of light reception to the light receiving unit 16, are parallel to each other.

[0080] The optical base 30 is also provided with an optical axis adjustment unit 32. The structure and function of the optical axis adjustment unit 32 are arbitrary, but for example, as shown in Fig. 4, it is provided with a vertical optical axis adjustment unit 3210 and a horizontal optical axis adjustment unit 3212. The vertical optical axis adjustment unit 3210 rotates the optical base 30 up and down around a vertical rotation axis 3214 in the left-right direction (X-axis direction), thereby rotating the direction of the optical axis vertically (up and down) while maintaining the parallel relationship between the light-transmitting optical axis of the light-transmitting unit 14 and the light-receiving optical axis of the light-receiving unit 16, thereby adjusting the optical axis angle θ.

[0081] The horizontal optical axis adjustment unit 3212 rotates the optical table 30 left and right around a horizontal rotation axis 3216 in the up and down direction (Y-axis direction) to rotate the direction of the optical axis left and right while maintaining the parallel relationship between the light-sending optical axis of the light-sending unit 14 and the light-receiving optical axis of the light-receiving unit 16. The adjustment angle range of the vertical optical axis adjustment unit 3210 and the horizontal adjustment unit 3212 is arbitrary, but is set to an angle range of ±5°, for example, so as not to exceed the incident angle of ±10° at which the reflectivity of the reflector 12 is sufficiently maintained.

[0082] The configurations and functions of the angle adjustment mechanisms of the vertical optical axis adjustment unit 3210 and the horizontal optical axis adjustment unit 3212 are arbitrary, but may be, for example, a manual optical axis adjustment unit that adjusts the angle by manual operation while visually checking the reflector 12 side using a sight and also checking the received light amount indication by a light receiving signal indicator or the like, or an automatic optical axis adjustment unit that automatically recognizes the received light signal and adjusts it based on a control signal from the control unit 24.

[0083] In the case of a manual optical axis adjustment unit, for example, an angle adjustment dial is provided on the light transmitter / receiver 10, and the optical axis angle is adjusted by rotating the angle adjustment dial. When adjusting the optical axis angle with the angle adjustment dial, a gear mechanism is used that reduces the speed of the rotation of the angle adjustment dial and transmits it to the vertical rotation shaft 3214 or the horizontal rotation shaft 3216 to enable angle adjustment of, for example, 0.1°. If the reduction ratio in this case is, for example, 1 / 50, the optical axis can be rotated by 0.1° when the dial is rotated by 5°, and the optical axis angle can be adjusted in 0.1° increments by rotating the angle adjustment dial.

[0084] In the case of the automatic optical axis adjustment unit, for example, a piezoelectric element is provided as an actuator, and the optical axis angle can be adjusted by changing the drive voltage applied to the piezoelectric element according to a control signal from the control unit 24. The structure and function of the automatic optical axis adjustment unit using a piezoelectric element are arbitrary, but for example, the optical table 30 is supported on the housing side of the light transmitter / receiver 10 so as to be able to swing freely, and a piezoelectric element corresponding to the vertical optical axis adjustment unit 3210 is arranged at a predetermined position on the Y axis passing through the swing center of the optical table 30, and a piezoelectric element corresponding to the horizontal optical axis adjustment unit 3212 is arranged at a predetermined position on the X axis passing through the swing center of the optical table 30. The angular resolution in this case is, for example, about 0.05°. Note that an actuator driven by a motor may be used instead of the piezoelectric element.

[0085] The control unit 24 mainly performs predetermined processing for fire monitoring and fault monitoring in the light transmitter / receiver 10, and is composed of a computer circuit equipped with a CPU, memory, various input / output ports, etc., and the functions realized by the execution of a program by the CPU are arbitrary, and includes, for example, a light transmitting control unit 42 and a light receiving control unit 44.

[0086] The light-transmitting control unit 42 controls the light-transmitting unit 14, and outputs a control signal to the light-transmitting drive unit 34 of the light-transmitting unit 14 at a predetermined light-transmitting timing, for example, at a cycle of 2 seconds, to cause the light-transmitting unit 14 to intermittently pass a forward current through the light-transmitting element 36 using a light-emitting diode, thereby controlling the light-transmitting signal light to be transmitted.

[0087] The light-receiving control section 44 samples and A / D-converts the light-receiving signal received by the light-receiving element 38 using a photodiode in the light-receiving section 16, which has been photoelectrically converted and amplified by the amplifier section 40, in synchronization with the output of a control signal from the light-transmitting control section 42 to the light-transmitting section 14, reads it as light-receiving data corresponding to the amount of received signal light, and performs various processes based on the light-receiving data. Note that in the following explanation, the light-receiving data may be explained as the amount of received light.

[0088] The light receiving control unit 44 includes a correlation determination unit 46 and a fault determination unit 48 for determining a fault when a fire cannot be detected normally due to the influence of a reflective obstacle or disturbance light, and also includes a fire determination unit 50 for fire monitoring during operation. The correlation determination unit 46 and the fault determination unit 48 will be described separately below.

[0089] The fire determination unit 50 determines whether or not there is a fire based on light reception data corresponding to the amount of light received by the light receiving unit 16. The function of the fire determination unit 50 is arbitrary, but the presence or absence of a fire is determined based on the attenuation state, for example, the attenuation rate D [%] of the amount of received light that increases due to smoke.

[0090] The fire determination unit 50 determines whether or not a fire has occurred based on the smoke attenuation rate D [%] by initially setting the initial amount of light received by the light receiving unit 16 during optical axis adjustment as a reference amount of light received Pro and storing it in the memory unit 26 so as to obtain an appropriate initial amount of light received. Each time the amount of light received by the light receiving unit 16 during fire monitoring is read as light reception data, the attenuation rate D is calculated using the initially set reference amount of light received Pro. D = {(Pro-Pr) / Pro} x 100 [%] When the light reduction rate D satisfies a predetermined fire determination condition, it is determined that a fire has occurred as fire smoke, and the occurrence of a fire is displayed on the operation display unit 28 via the control unit 24, and a fire alert signal is output from the output unit 52 to the receiver to issue a fire alarm. Here, the fire determination condition based on the light reduction rate D is arbitrary, but may be, for example, when the light reduction rate D is equal to or exceeds a predetermined threshold value Dth, or when the state in which the light reduction rate D is equal to or exceeds a predetermined threshold value Dth continues for a predetermined period of time.

[0091] In addition, the dimming reflective smoke detector as in the embodiment must pass the operation test and the non-operation test defined as standards in Japan. For example, in the case of conforming to the two-sensitivity standard for dimming separate smoke detectors, when the nominal minimum and maximum installation distances between the transmitter / receiver 10 and the reflector 12 are 10 m and 100 m, respectively, in the operation test, a dimming filter with a dimming rate of 50% is placed in the optical path between the transmitter / receiver 10 and the reflector 12 (corresponding to a 75% attenuation of the received light signal in the case of a dimming reflective smoke detector, since both the transmitted light signal light and the reflected light signal light are dimmed by the dimming filter), the transmitter / receiver 10 outputs a fire alarm signal within 30 seconds, and in the non-operation test, a dimming filter with a dimming rate of 30% is placed in front of the reflector 12 (similarly, corresponding to a 51% attenuation of the received light signal in the case of a dimming reflective smoke detector), and the transmitter / receiver 10 passes the test if it does not output a fire alarm signal within 2 minutes.

[0092] The fire determination unit 50 may determine the presence or absence of a fire based on the light receiving rate S [%] of the amount of light attenuated by smoke as the attenuation state. The light receiving rate S [%] can be said to be the smoke transmittance in the optical path combining the outgoing path (transmitted signal light) and the return path (reflected signal light) of the signal light, that is, the smoke transmittance of the transmitted signal light multiplied by the smoke transmittance of the reflected signal light reflected by the reflector 12, and is calculated based on the received light amount Pr and the preregistered reference light receiving amount Pro. S = (Pr / Pro) x 100 [%] The value is calculated as follows, and is between the light extinction rate D [%] S=100-D [%] When the light-receiving rate S satisfies a predetermined fire judgment condition, it is judged that a fire exists as fire smoke has been generated, and the occurrence of a fire is displayed on the operation display unit 28 via the control unit 24, and a fire alert signal is output from the output unit 52 to the receiver to issue a fire alarm. Here, the fire judgment condition based on the light-receiving rate S is arbitrary, but may be, for example, when the light-receiving rate S is equal to or lower than a predetermined threshold value Sth, or when the state in which the light-receiving rate S is equal to or lower than the predetermined threshold value Sth continues for a predetermined period of time.

[0093] The storage unit 26 is for storing information used for processing in the light transmitter / receiver 10. Information stored in the storage unit 26 includes, for example, fault determination conditions for the fault determination unit 48 to determine a fault, the reference light receiving amount Pro, a reference proportional coefficient (reference correlation) and drive current information used in fault determination by the fault determination unit 48 described later, and other necessary information such as fire determination conditions for the fire determination unit 50 to determine a fire, the installation distance and initial optical axis angle set at the time of initial setup, etc.

[0094] The operation display unit 28 performs the initial setting of the dimming reflective smoke detector 1, fire monitoring, restoration of the fire detection status, and other operations required, and displays the fire monitoring status, fault status, fire occurrence status, etc., and outputs an operation signal to the control unit 24, and the display is controlled by a display signal from the control unit 24.

[0095] The specific configuration of the operation and display unit 28 is arbitrary, but the operation unit may be provided with a registration switch which is operated when storing (registering) information in the memory unit 26, and various switches necessary for fire monitoring, etc., and the display unit may be provided with LED indicator lights such as a monitoring indicator light which indicates, for example, by lighting green when fire monitoring is in progress, a fault indicator light which indicates, for example, by lighting yellow when a fault has occurred, and an alarm indicator light which indicates, for example, by lighting red when a fire has occurred, and a liquid crystal display device may be used to display characters, images, etc., of information necessary for initial setup, fire monitoring, and fault monitoring, and an indicator which displays the amount of received light, etc. may also be provided.

[0096] [d. Disability determination] Next, a fault determination in the dimming reflective smoke detector of the embodiment will be described.

[0097] In order to determine a condition in which a fire cannot be detected normally due to the influence of a reflective obstacle or external light disturbance, a correlation determination unit 46 and a failure determination unit 48 are provided in the light receiving control unit 44 in the control unit 24 of the light transmitter / receiver 10, as shown in Figure 3.

[0098] (d1. Correlation determination section) First, the correlation determination unit 46 will be described. As shown in Fig. 1 and Fig. 2, during operation in which the light transmitter / receiver 10 and the reflector 12 are installed facing each other in the monitored space 11, the correlation determination unit 46 applies, for example, a proportional relationship between the amount of light transmitted Pe and the amount of light received Pr, as a correlation between the amount of light transmitted Pe and the amount of light received Pr, at a predetermined fault determination timing, and determines a proportionality coefficient K as an index (object of analysis, object of determination) of the proportional relationship between the amount of light transmitted Pe and the amount of light received Pr.

[0099] Here, the fault determination timing is arbitrary, but for example, the fault determination is performed at a predetermined cycle, and the cycle is arbitrary, but for example, it is a fixed cycle such as once a day or once per predetermined time unit. Furthermore, in addition to the fixed cycle, the fault determination timing also includes a case where the amount of light received by the light receiving unit 16 has changed beyond a predetermined value with respect to a preregistered reference amount of received light Pro, and the amount of change in the amount of received light with respect to the reference amount of received light Pro at which the fault determination is performed is arbitrary, but in order to exclude gradual changes, it is set to, for example, a case where the amount has changed beyond about several percent.

[0100] (d2. Judgment based on proportionality coefficient) Next, a description will be given of the determination based on the proportionality coefficient by the correlation determination unit 46. In order to perform the determination based on the proportionality coefficient, the correlation determination unit 46 changes the amount of light Pe of the transmitted signal light within a predetermined range, and detects the amount of light Pr received by the light receiving unit 16 in response to the change.

[0101] In making a judgment based on the proportionality coefficient in the correlation judgment unit 46, a plurality of current values ​​obtained by dividing the light-emitting current of the light-emitting element 36 in stages within a predetermined range from a minimum value to a maximum value, for example, a reference light-emitting current Ieo adjusted so that the maximum value of the light-emitting current is a light-transmitting amount at which the light-receiving unit 16 obtains a reference received light amount Pro, are set, and drive current information including a plurality of drive current values ​​divided in stages within a predetermined range from a minimum value to the reference light-emitting current Ieo and a drive time is stored in advance in the storage unit 26. Then, the correlation judgment unit 46 temporarily suspends the fire judgment process of the fire judgment unit 50 at the fault judgment timing, reads out the drive current information from the storage unit 26 and transmits it to the light-transmitting control unit 42, and the light-transmitting control unit 42 outputs a control signal to the light-transmitting drive unit 34, and an emission current that increases in stages, for example, from a current value that is a minimum value to a current value that is a maximum value, is intermittently passed from the light-transmitting drive unit 34 to the light-transmitting element 36, thereby gradually increasing the light-transmitting amount Pe of the transmitted light signal light.

[0102] At this time, the correlation determination unit 46 reads (samples) the light reception signal received by the light receiving element 38 of the light receiving unit 40 and amplified by the amplifier 40 in synchronization with the control signal (intermittent drive signal) output from the light transmission control unit 42, and detects the amount of received light Pr. The intermittent drive period and the light reception sampling period synchronized therewith may be shorter than those during normal monitoring operation. In this way, the time required for fault determination can be shortened.

[0103] Next, the correlation determination unit 46 uses the stepwise increased amounts of light transmission Pe(1), Pe(2), ... Pe(n) and the amounts of received light Pr(1), Pr(2), ... Pr(n) to make a determination based on the proportionality coefficient K. The determination based on the proportionality coefficient K first determines whether or not the stepwise increased amount of light emission Pe and the amount of received light Pr are proportional to each other, and calculates the proportionality coefficient K if it is determined that they are proportional. Here, n is any positive integer.

[0104] The determination of the proportional relationship is arbitrary, but for example, when the light transmission amounts Pe(1), Pe(2), ... Pe(n) are increased stepwise by a certain predetermined value, if the light reception amounts Pr(1), Pr(2), ... Pr(n) also increase stepwise by a certain predetermined value, it is determined that the two are proportional. On the other hand, if the light reception amounts Pr(1), Pr(2), ... Pr(n) do not increase stepwise by a certain predetermined value, it is determined that the two are not proportional. Then, if it is determined that the light emission amount and the light reception amount that change stepwise are proportional to each other, the proportionality coefficient K is calculated. The proportionality coefficient K can be calculated by any method, but for example, the proportionality coefficient K is calculated by dividing the difference between the light reception amounts Pr(x) and Pr(x-1) by the difference between the light transmission amounts Pe(x) and Pe(x-1) and taking the average. Note that x = 2, 3 ... n.

[0105] In addition, the proportionality determination and the proportionality coefficient K may be performed simultaneously. For example, when the amount of received light Pr(2) is detected, the proportionality coefficient is calculated by dividing the difference between the amounts of received light Pr(2) and Pr(1) by the difference between the amounts of transmitted light Pe(2) and Pe(1), and then the proportionality coefficient at each stage is calculated each time the amounts of received light Pr(3), Pr(4), Pr(n) are detected. If all the proportionality coefficients match, it is determined that there is a proportional relationship and the calculated proportionality coefficient K is the determination result, and if they do not match, it is determined that there is no proportional relationship. Note that "match" here is not limited to perfect match, but has a range within which it is recognized as a match based on a predetermined determination criterion.

[0106] In addition, as shown in FIG. 1, when the initial setting is completed by arranging the light transmitter / receiver 10 and the reflector 12 facing each other in the monitored space 11 and adjusting the optical axis to avoid or reduce the effects of reflective obstacles and ambient light, the correlation determination unit 46 changes the amount of light transmitted Pe of the light signal light within a predetermined range by operating a registration switch on the operation display unit 28, etc., detects the amount of light received Pr received by the light receiving unit 16 in response to this, and pre-registers the reference proportionality coefficient Kref by storing the proportionality coefficient K determined using the amount of light transmitted Pe and the amount of light received Pr in the memory unit 26 as the reference proportionality coefficient Kref.

[0107] (d3. Fault determination section) Next, the fault determination unit 48 will be described. In this description, reference will be made to Fig. 5, which shows the relationship between the proportionality coefficient between the amount of transmitted light and the amount of received light determined by the correlation determination unit and the reference proportionality coefficient. Fig. 5(A) shows an example of the relationship in a normal state not affected by a reflective obstacle or disturbance light, Fig. 5(B) shows an example of the relationship in a fault state affected by a reflective obstacle, Fig. 5(C) shows an example of the relationship in a fault state affected by disturbance light, and Fig. 5(D) shows an example of the relationship in a fault state affected by both a reflective obstacle and disturbance light.

[0108] The relationship between the amount of light transmission Pe and the amount of light reception Pr in a normal state without the influence of reflective obstacles and ambient light is a proportional relationship that can be expressed by a straight line 102 having a slope of a proportionality coefficient K1, for example, as shown in FIG. 5(A). The straight line 100 having a slope of the reference proportionality coefficient Kref and the straight line 102 having a slope of the proportionality coefficient K1 determined at the fault determination timing have almost the same slope, so that the two straight lines are in a matched state. In this way, when the straight line 102 having a slope of the proportionality coefficient K1 matches the straight line 100 having a slope of the reference proportionality coefficient Kref, the fault determination unit 48 does not determine that there is a fault. Note that the "match" mentioned here is not limited to a perfect match, but has a range that is recognized as a match based on a predetermined determination criterion.

[0109] In addition, the relationship between the amount of light transmitted Pe and the amount of light received Pr in an obstructed state influenced by a reflective obstacle is a proportional relationship that can be expressed by a straight line 104 having a slope of a proportionality coefficient K2, for example, as shown in Figure 5 (B), where the slope of the straight line 104 is increased compared to the straight line 100 having the slope of the reference proportionality coefficient Kref, and the proportionality coefficient K2 increases more than the reference proportionality coefficient Kref.

[0110] In addition, the relationship between the amount of light sent Pe and the amount of light received Pr in a fault state affected by disturbance light such as sunlight or illumination light is often not proportional, so the correlation determination unit 46 determines that there is no proportional relationship and does not calculate a proportionality coefficient. In addition, the relationship between the amount of light sent Pe and the amount of light received Pr in a fault state affected by disturbance light such as sunlight or illumination light may be proportional, for example, as shown in Fig. 5(C), and the line 106 is a line that has been moved parallel to the line 100 with approximately the same slope as the line 100 in the direction in which the amount of light received Pr has increased by an amount indicated by a dashed line 108 due to the influence of disturbance light, and the proportionality coefficient K3 is approximately the same as the reference proportionality coefficient Kref.

[0111] Furthermore, in a fault state affected by both a reflective obstacle and disturbance light, the relationship between the amount of transmitted light Pe and the amount of received light Pr is often not proportional due to the influence of disturbance light, so the correlation determination unit 46 determines that there is no proportional relationship and does not calculate a proportionality coefficient. Also, the relationship between the amount of transmitted light Pe and the amount of received light Pr in a fault state affected by both a reflective obstacle and disturbance light may be proportional, for example, as shown in Fig. 5(D) by a straight line 110 having a slope of a proportionality coefficient K4, and the straight line 110 is a straight line in which the amount of received light Pr is increased by the amount shown by the broken line 108 due to the influence of disturbance light compared to the straight line 100 having a slope of a reference proportionality coefficient Kref, and the slope of the straight line is further increased due to the influence of a reflective obstacle, and the proportionality coefficient K4 increases more than the proportionality coefficient Kref.

[0112] For this reason, when the fault determination condition that "the relationship between the amount of light transmitted Pe and the amount of light received Pr is not proportional, and the proportionality coefficient K has not been calculated" is satisfied, the fault determination unit 48 determines that "the fault is at least due to the influence of ambient light."

[0113] Here, when "the relationship between the amount of light transmitted Pe and the amount of light received Pr is not proportional and the proportionality coefficient K has not been calculated," this includes cases where the light is affected by external disturbance light, as well as cases where the light is affected by a reflective obstacle in addition to external disturbance light. Although the fault itself can be determined, since there are multiple possible patterns that may be the cause of the fault, it is not possible to completely identify the specific factor that causes the fault. Therefore, a "fault that is at least affected by external disturbance light" is included in the concept of a "non-signal light fault" that is affected by some kind of factor, including external disturbance light.

[0114] Furthermore, when the fault determination condition is satisfied that "the relationship between the amount of light transmitted Pe and the amount of light received Pr is proportional, and the proportionality coefficient K deviates from the reference proportionality coefficient Kref by more than a predetermined value (for example, a value that is +10% of the reference proportionality coefficient Kref)," the fault determination unit 48 determines that "the fault is at least due to the influence of a reflective obstacle."

[0115] Here, "when the relationship between the amount of light transmitted Pe and the amount of light received Pr is proportional and the proportionality coefficient K deviates from the reference proportionality coefficient Kref by more than a predetermined value" includes cases where there is influence from a reflective obstacle as in Figure 5(B), as well as cases where there is influence from external light in addition to a reflective obstacle as in Figure 5(D). Although the obstacle itself can be determined, since there are multiple possible patterns that may be the cause of the obstacle, it is not possible to completely identify the specific factor that causes the obstacle. Therefore, "an obstacle that is at least influenced by a reflective obstacle" is included in the concept of "non-signal light obstacle" that is influenced by some kind of factor including a reflective obstacle.

[0116] In addition, both of the cases where "the relationship between the amount of light sent Pe and the amount of light received Pr is not proportional and the proportionality coefficient K has not been calculated" and "the relationship between the amount of light sent Pe and the amount of light received Pr is proportional and the proportionality coefficient K deviates from the reference proportionality coefficient Kref by more than a specified value" are included in the concept of "the correlation between the amount of light sent and the amount of light received determined by the correlation determination unit deviates from the reference correlation by more than a specified range."

[0117] Furthermore, when the fault determination unit 48 satisfies the fault determination condition that "the relationship between the amount of transmitted light Pe and the amount of received light Pr is proportional, and the proportionality coefficient K matches the reference proportionality coefficient Kref, but the detected amount of received light Pr is a predetermined value that exceeds the reference amount of received light Pro (for example, a value that is +10% of the reference amount of received light Pro)", this means that there is an effect of disturbance light without being affected by a reflective obstacle as shown in Figure 5 (C), and therefore the fault determination unit 48 determines that there is a "fault indicating that there is an effect of disturbance light (disturbance light fault)".

[0118] Then, the fault determination unit 48, having made the determination, turns on the fault indicator light on the operation display unit 28, for example yellow, and outputs a fault determination signal indicating the determined "non-signal light fault" or "disturbance light fault" to the receiver via the output unit 52. In the case of a "non-signal light fault," a fault alarm is issued to the effect that there is some influence from a reflective obstacle or disturbance light that is causing the non-signal light, and in the case of a "disturbance light fault," a fault alarm is issued to the effect that there is influence from disturbance light.

[0119] Furthermore, the fault determination unit 48 may further add a fault determination condition. For example, when the fault determination condition "the relationship between the amount of light transmitted Pe and the amount of light received Pr is proportional, and the proportionality coefficient K deviates from the reference proportionality coefficient Kref by more than a predetermined value" is satisfied, the fault determination unit 48 further determines whether or not the fault determination condition "the amount of light received detected when the amount of light transmitted is set to zero is equal to or less than a predetermined value (the amount of increase in the amount of light received due to the effect of expected disturbance light)" is satisfied, and when the fault determination condition "the amount of light received detected when the amount of light transmitted is set to zero is equal to or less than the predetermined value" is satisfied, it determines that there is no effect of disturbance light, and determines that there is an "effect of a reflective obstacle (reflective obstacle fault)", and turns on the fault indicator lamp of the operation display unit 28, for example, in yellow, and outputs a fault determination signal indicating the determined "reflective obstacle fault" to the receiver via the output unit 52, thereby issuing a fault alarm indicating that there is an effect of a reflective obstacle.

[0120] On the other hand, if the fault judgment condition "the amount of received light detected when the amount of transmitted light is set to zero is equal to or less than a predetermined value" is not satisfied, it is determined that there is also interference from external light, and a "reflective obstacle failure" and "external light failure" are judged, and the fault indicator light on the operation display unit 28 is turned on, for example, yellow, and a fault judgment signal indicating the determined "reflective obstacle failure" and "external light failure" is output to the receiver via the output unit 52, and a fault alarm is issued to the effect that there is interference from a reflective obstacle and external light.

[0121] This makes it possible to reduce the number of cases where a fault is detected but the specific cause of the fault is not fully identified and the fault is instead determined to be a "non-signal light fault," making it possible to identify the type of fault in more detail and determine the fault.

[0122] [e. Fault determination operation of dimming reflective smoke detector] Next, a fault determination operation of the dimming reflective smoke detector will be described with reference to the flow chart of FIG.

[0123] As shown in FIG. 6, after the optical transmitter / receiver 10 and the reflector 12 are installed and the optical axis is adjusted to avoid or reduce the effects of reflective obstacles and ambient light, the initial settings are completed. Then, the drive current information and the proportionality coefficient determined by the correlation determination unit 46 are stored in the memory unit 26 as the reference proportionality coefficient Kref and pre-registered (step S1).

[0124] Next, when the correlation determination unit 46 determines that the fault determination timing is, for example, a fault determination period in which determination is made at a predetermined period (step S2), or a change in the amount of received light that exceeds a predetermined value with respect to the reference amount of received light (step S3), the light transmitting unit 14 transmits the light signal light by gradually changing the amount of light transmitted based on the drive current information stored in the memory unit 26, and the light is received by the light receiving unit 16 to detect the amount of received light for the light signal light having mutually different amounts of light transmitted, and a proportionality coefficient K between the amount of light transmitted and the amount of received light is determined as an index of the proportional relationship between the amount of light transmitted and the amount of light received (step S4).

[0125] Next, the fault determination unit 48 compares the proportionality coefficient K determined by the correlation determination unit 46 with a pre-registered reference proportionality coefficient Kref, and if the determined proportionality coefficient deviates from the reference proportionality coefficient by more than a predetermined value (including cases where the relationship between the amount of light sent and the amount of light received is not proportional and the proportionality coefficient K is not calculated), it determines that a fault (non-signal light fault) has occurred due to some influence from a reflective obstacle or external light that causes non-signal light, and turns on the fault indicator light on the operation display unit 28 and outputs a fault determination signal indicating a ``non-signal light fault'' to the receiver to issue a fault alarm to the effect that the non-signal light is being influenced by some influence from a reflective obstacle or external light that causes non-signal light (steps S6, 7, 8).

[0126] Furthermore, if the proportionality coefficient K determined by the correlation determination unit 46 matches the pre-registered reference proportionality coefficient Kref and the detected amount of received light Pr is a predetermined value exceeding the reference amount of received light Pro, the fault determination unit 48 determines that a fault has occurred due to the influence of disturbance light (disturbance light fault), turns on the fault indicator light of the operation display unit 28, and outputs a fault determination signal indicating a "disturbance light fault" to the receiver to issue a fault alarm indicating the influence of disturbance light (steps S6, 9, 10, 8).

[0127] Furthermore, after step S4, a step for determining whether or not a fault determination condition of "determining whether or not there is a proportional relationship" is provided, and if it is determined that there is a proportional relationship, proceed to step S5, and if it is determined that there is no proportional relationship, a "non-signal light fault" is determined. Furthermore, after step S6, a step for determining whether or not a fault determination condition of "the amount of received light detected when the amount of transmitted light is set to zero is equal to or less than a predetermined value" is provided, and if the fault determination condition is satisfied instead of step S7, a "reflective obstacle fault" is determined, and if the fault determination condition is not satisfied, a "reflective obstacle fault" and an "external light fault" are determined.

[0128] [f. Modifications of the present invention] Modifications of the dimming reflective smoke detector according to the present invention will now be described. In addition to the above-described embodiment, the dimming reflective smoke detector according to the present invention includes the following modifications.

[0129] (Layout of light transmitting and receiving parts) In the above embodiment, the light transmitting section and the light receiving section of the light transmitter / receiver are arranged horizontally (left-right), but the arrangement of the light transmitting section and the light receiving section in the light transmitter / receiver is arbitrary and may be arranged vertically (up-down).

[0130] (Disability determination) In the above embodiment, the types of faults judged by the fault judgment unit 48 include “reflective obstacle fault,” “external light fault,” and “non-signal light fault,” and the fault indicator light of the operation display unit 28 may be lit in different display modes depending on the type of fault.

[0131] (Canceling fault detection operation) In the above embodiment, the fire monitoring operation is temporarily suspended during the fault judgment operation, but if the correlation judgment unit 46 determines that there is no correlation between the amount of light transmitted and the amount of light received during the fault judgment operation, for example, if it determines that a proportional relationship is not obtained between the amount of light transmitted and the amount of light received, it is possible that a fire has broken out and smoke has flowed into the monitored space.For example, if the amount of light received detected when the amount of light transmitted is set to zero is equal to or less than a predetermined value that is below the increase in the amount of light received due to the expected influence of external light, it is more likely that the lack of proportional relationship is due to the influence of smoke from a fire rather than the influence of external light, so the fault judgment operation is canceled and the temporarily suspended fire monitoring operation is resumed.

[0132] (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. [Explanation of symbols]

[0133] 1: Dimmable reflective smoke detector 10: Transmitter / receiver 11: Surveillance space 12:Reflector 13: Signal cable 14: Light transmitting unit 15: Irradiation image 16: Light receiving part 18: Fire smoke 20: Reflective obstacles 22: Optical unit 24: Control unit 26: Storage section 28: Operation display section 30:Optical bench 32: Optical axis adjustment section 3210: Vertical beam adjustment unit 3212: Horizontal beam adjustment unit 3214: Vertical swivel shaft 3216: Lateral rotation axis 34: Light transmission drive unit 36: Light transmitting element 38: Photodetector 40: Amplification section 42: Light transmission control unit 44: Light receiving control unit 46: Correlation determination unit 48: Fault determination unit 50:Fire judgment department 52: Output section 60: Reflex Reflector 62: Retroreflective elements

Claims

1. A light-receiving device having an integrated light-transmitting section and a light-receiving section is installed on one side of a monitored space, and a reflector is installed on the other side of the monitored space opposite the light-transmitting section, a light-transmitting signal light from the light-transmitting section is transmitted to the reflector, and the light-receiving section receives the reflected signal light from the light-transmitting section, thereby detecting attenuation of the received signal light, thereby detecting the presence of smoke in the monitored space and detecting a fire, a correlation determination unit that determines a correlation between an amount of the transmitted signal light and an amount of the light received by the light receiving unit; a fault determination unit that determines that a fault has occurred when the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit satisfies a predetermined fault determination condition; A dimming reflective type smoke detector comprising:

2. 2. The light-reducing reflective smoke detector according to claim 1, the correlation determination unit registers in advance, as a reference correlation, a correlation between the amount of transmitted light and the amount of received light determined in a state in which the amount of received light is not affected by received non-signal light other than the received signal light received by the light receiving unit; The fault determination unit compares the correlation between the amount of light transmitted and the amount of light received determined by the correlation determination unit with the reference correlation, and determines that a fault has occurred if a specified fault determination condition is satisfied.

3. 3. The light-reducing reflective smoke detector according to claim 2, The correlation determination unit further registers in advance the amount of received light detected in a state in which the amount of received light is not affected by the received non-signal light as a reference amount of received light, The fault determination unit compares the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit with the reference correlation, and compares the detected amount of received light with the reference amount of received light, and determines that a fault has occurred if specified fault determination conditions are met.

4. 4. The light-reducing reflective smoke detector according to claim 3, The fault determination unit is determining that a fault has occurred due to an influence of non-signal light when the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit deviates from the reference correlation by more than a predetermined range; A dimming reflective type smoke detector characterized in that when the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit matches the standard correlation and the detected amount of received light is a predetermined value that exceeds the standard amount of received light, the detector determines that a fault has occurred due to the influence of external light.

5. 2. The light-reducing reflective smoke detector according to claim 1, A dimming reflective type smoke detector characterized in that the fault determination unit performs a process to determine a fault when there is a change in the amount of received light that exceeds a predetermined value during operation and / or at a predetermined interval.

6. 2. The light-reducing reflective smoke detector according to claim 1, the correlation determination unit applies a proportional relationship between an amount of the transmitted signal light and an amount of the light received by the light receiving unit as the correlation, and performs a determination based on a proportional coefficient of the proportional relationship; A dimming reflective type smoke detector, characterized in that the fault determination unit determines that a fault has occurred when the proportionality coefficient determined by the correlation determination unit satisfies the specified fault determination condition.

7. 7. The light-reducing reflective smoke detector according to claim 6, the correlation determination unit registers in advance a proportionality coefficient determined in a state not influenced by received non-signal light other than the received signal light received by the light receiving unit as a reference proportionality coefficient, and also registers in advance an amount of received light as a reference amount of received light, The fault determination unit is After the correlation determination unit determines that the amount of transmitted light and the amount of received light are in a proportional relationship, when the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit deviates from the reference correlation by more than a predetermined range and the amount of received light detected when the amount of transmitted light is set to zero is equal to or less than a predetermined value, a determination is made that an obstacle is being affected by a reflective obstacle; when the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit deviates from the reference correlation by exceeding a predetermined range and the amount of received light detected when the amount of transmitted light is set to zero exceeds a predetermined value, a determination is made that an obstacle is present, indicating that the obstacle is influenced by a reflective obstacle and that the obstacle is influenced by disturbance light; A dimming reflective type smoke detector characterized in that when the correlation between the amount of transmitted light and the amount of received light determined by the correlation determination unit matches the standard correlation and the detected amount of received light is a predetermined value that exceeds the standard amount of received light, the detector determines that a fault has occurred due to the influence of external light.

8. 8. The light-reducing reflective smoke detector according to claim 7, The fault determination unit is After the correlation determination unit determines that the amount of light transmitted and the amount of light received are not proportional to each other, if the amount of received light detected when the amount of transmitted light is set to zero exceeds a predetermined value, it is determined that a fault is occurring due to the influence of non-signal light; A dimming type reflective smoke detector characterized in that, when the amount of received light detected when the amount of transmitted light is set to zero is below a predetermined value, the fault determination operation is cancelled and the operation of the dimming type reflective smoke detector is changed to perform a fire monitoring operation.

9. A method for determining a fault in a dimming reflective smoke detector, the method comprising: installing a light transmitter / receiver having an integrated light transmitter and receiver in one side of a monitored space, and installing a reflector in the other side of the monitored space opposite the light transmitter / receiver; transmitting a light transmission signal from the light transmitter to the reflector; detecting attenuation of a light reception signal received by a light receiver, the light transmission signal reflected by the reflector, and detecting the presence of smoke in the monitored space, thereby detecting a fire, comprising: A correlation determination unit determines a correlation between an amount of the transmitted signal light and an amount of the received light received by the light receiving unit; A method for determining a fault in a dimming reflective type smoke detector, characterized in that a fault determination unit determines that a fault has occurred if the correlation between the amount of light transmitted and the amount of light received determined by the correlation determination unit satisfies a specified fault determination condition.

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