Extinction and reflection type smoke detector, optical axis adjustment method thereof, and extinction and reflection type smoke detection system

Abstract

To efficiently and reliably set the optimum optical axis angle for avoiding or mitigating influence of a reflective obstacle at an initial optical axis angle.SOLUTION: In an extinction and reflection type smoke detector 1, a light transmitter / receiver 10 including a light transmitter 14 and a light receiver 16 comprises: an optical axis adjustment section 32 arranged in a monitoring space 11 to face a reflector 12, so as to vary an optical axis angle of a light transmission optical axis of a light transmission signal light from the light transmitter 14 with respect to the reflector 12; a correlation determination section 48 for determining correlation between a light transmission amount of the light transmission signal light and a light reception amount of a light to be received by the light receiver 16 for each one of the plurality of mutually different optical axis angles; and an optical axis angle extraction section 50 for extracting the optimum initial optical axis angle for avoiding or mitigating influence of a reflective obstacle inside a monitoring space 11, for example, as a light reception non-signal light other than a light reception signal light to be received by the light receiver 16 among the mutually different optical axis angles based on a plurality of determination results determined by the correlation determination section 48 for each optical axis angle.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a dimming type reflective smoke detector, an optical axis adjustment method, and a dimming type reflective smoke detection system 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, thereby detecting 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 into one unit 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 as 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). [Prior art documents] [Patent documents]

[0004] [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]

[0005] Here, even if the initial setting is performed to obtain an initial amount of light reception that is deemed appropriate by adjusting the optical axis, if there is a reflective obstacle other than the reflector, such as a beam or duct, in or near the irradiation area of ​​the light transmitted from the light transmitting unit of the light transmitting / receiving unit, and the reflected light from the reflective obstacle is received by the light receiving unit of the light transmitting / receiving unit, the presence of smoke and the smoke concentration may not be properly detected depending on the location of smoke generation. However, when a dimming type reflective smoke detector is installed in a monitored space and the optical axis is adjusted as the initial setting, it is not possible to check whether there is a reflective obstacle in the range of light from the light transmitting unit based on the drawing, for example, unless the reflective obstacle is shown on the installation building drawing. In such cases, the detector is checked visually or the like. Thus, in the past, there was no method of efficiently and reliably checking the influence of a reflective obstacle.

[0006] The present invention aims to provide a dimming type reflective smoke detector, an optical axis adjustment method thereof, and a dimming type reflective smoke detection system that enable the optimal optical axis angle that avoids or mitigates the effects of reflective obstacles to be set as the initial optical axis angle efficiently and reliably. [Means for solving the problem]

[0007] (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, an optical axis adjustment unit that changes an optical axis angle of an optical axis of a transmitted signal light relative to a reflector; 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 for each of a plurality of mutually different optical axis angles; an optical axis angle extraction unit that extracts an optimal initial optical axis angle that avoids or reduces the influence of received non-signal light other than the received signal light received by the light receiving unit from a plurality of mutually different optical axis angles based on a plurality of judgment results judged for each optical axis angle by the correlation judgment unit; The present invention is characterized in that:

[0008] (Extraction of optimal initial optical axis angle based on reference 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 for each optical axis angle in a state not affected by the received non-signal light; The optical axis angle extraction unit extracts, from the correlations between the amount of transmitted light and the amount of received light determined by the correlation determination unit for each optical axis angle, an optical axis angle that matches a corresponding reference correlation or has a minimum deviation from the reference correlation within a predetermined allowable angle range, as an optimal initial optical axis angle.

[0009] (Extraction of optimal initial optical axis angle based on vertical and / or horizontal optical axis angle adjustment) The optical axis of the signal light transmitted to the reflector of the light transmitting section and the optical axis of the signal light received from the reflector at the light receiving section are in a parallel relationship. the optical axis adjustment unit rotates the direction of the light transmitting optical axis vertically and / or horizontally while maintaining a parallel relationship between the light transmitting optical axis and the light receiving optical axis, thereby varying the optical axis angle of the light transmitting optical axis; the correlation determination unit determines the correlation between the amount of transmitted light and the amount of received light at each optical axis angle by varying the optical axis angle of the transmitting optical axis vertically and / or horizontally using the optical axis adjustment unit, and preregisters as a reference correlation the correlation between the amount of transmitted light and the amount of received light determined for each optical axis angle in a state not affected by the received non-signal light; The optical axis angle extraction unit extracts, from the correlations between the amount of transmitted light and the amount of received light determined by the correlation determination unit for each optical axis angle, an optical axis angle that matches a corresponding reference correlation or has a minimum deviation from the reference correlation within a predetermined allowable angle range, as an optimal initial optical axis angle.

[0010] (Pre-registration of baseline correlations for different installation distances) The correlation determining section registers in advance reference correlations determined for each of the installation distances between a plurality of mutually different light transmitters / receivers and reflectors and for each of the optical axis angles.

[0011] (Extraction of initial optical axis angle when multiple correlations are judged to match or have minimal deviation from the reference correlation) When multiple optical axis angles are determined within a predetermined allowable angle range to be the same as or have a minimum deviation from the reference correlation, the optical axis angle extraction unit extracts the minimum optical axis angle or the optical axis angle at which the amount of light received by the light receiving unit is maximum as the optimal initial optical axis angle.

[0012] (Determination process based on proportionality coefficient) the correlation determination unit applies a proportional relationship between the amount of transmitted light of the transmitted signal light and the amount of received light of the light received by the light receiving unit as the correlation, and makes a determination based on a proportional coefficient of the proportional relationship, or applies a proportional relationship between the amount of transmitted light of the transmitted signal light and the amount of received light of the light received by the light receiving unit as the correlation, and makes a determination based on the proportional coefficient of the proportional relationship, and also applies a proportional relationship between the amount of transmitted light and the amount of received light in a state not affected by the received non-signal light as a reference correlation, and pre-registers a reference proportional coefficient which is the proportional coefficient of the proportional relationship; The optical axis angle extraction unit extracts an optimal initial optical axis angle that avoids or mitigates the influence of the received non-signal light from a plurality of mutually different optical axis angles based on a plurality of proportionality coefficients determined for each optical axis angle by the correlation determination unit, or extracts, from among the proportionality coefficients determined for each optical axis angle by the correlation determination unit, an optical axis angle having a proportionality coefficient that matches a corresponding reference proportionality coefficient or has a minimum deviation from the reference proportionality coefficient within a predetermined allowable angle range, as an optimal initial optical axis angle.

[0013] (Method of adjusting the optical axis of a dimming reflective smoke detector) The present invention provides a method for adjusting an optical axis of 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: The optical axis adjustment unit varies an optical axis angle of the optical axis of the transmitted signal light relative to the reflector; a correlation determination unit determines a correlation between an amount of transmitted signal light and an amount of received light received by a light receiving unit for each of a plurality of mutually different optical axis angles; The optical axis angle extraction unit extracts an optimal initial optical axis angle from a plurality of mutually different optical axis angles based on a plurality of judgment results judged for each optical axis angle by the preliminary judgment unit, which avoids or mitigates the influence of received non-signal light other than the received signal light received by the light receiving unit.

[0014] (Dimmable reflective smoke detection system) The present invention provides a light-receiving device having an integrated light-transmitting section and a light-receiving section, which 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, and which transmits a light-transmitting signal light from the light-transmitting section to the reflector, and detects the presence of smoke in the monitored space by detecting attenuation of a light-receiving signal light received by the light-receiving section after the light-transmitting signal light is reflected by the reflector, thereby detecting a fire, comprising: an optical axis adjustment unit that changes an optical axis angle of the optical axis of the transmitted signal light relative to a reflector; 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 for each of a plurality of mutually different optical axis angles; an optical axis angle extraction unit that extracts an optimal initial optical axis angle that avoids or reduces the influence of received non-signal light other than the received signal light received by the light receiving unit from a plurality of mutually different optical axis angles based on a plurality of judgment results judged for each optical axis angle by the correlation judgment unit; The present invention is characterized in that The correlation determination section and the optical axis angle extraction section are provided in an external device connected to the dimming reflective smoke detector. Effect of the Invention

[0015] (Effects of dimming reflective smoke detectors) The present invention is a dimming type reflective smoke detector that detects a fire by detecting the presence of smoke in the monitored space by detecting attenuation of a received signal light received by the light receiving unit after the reflected signal light from the light transmitting unit is received by the light receiving unit and a light transmitting unit is installed on one side of a monitored space opposite to the light transmitting unit, and the light transmitting unit transmits a light signal light to the reflector, and detects a fire by detecting attenuation of a received signal light reflected by the reflector from the light transmitting unit. The smoke detector has an optical axis adjustment unit that varies the optical axis angle of the light transmitting optical axis of the light transmitting signal light with respect to the reflector, a correlation determination unit that determines the correlation between the amount of light transmitted by the light transmitting signal light and the amount of light received by the light receiving unit for each of a plurality of optical axis angles different from each other, and a correlation determination unit that determines the correlation between the amount of light transmitted by the light transmitting unit and the amount of light received by the light receiving unit for each of a plurality of optical axis angles different from each other based on a plurality of determination results determined by the correlation determination unit for each optical axis angle. An optical axis angle extraction unit is provided that extracts an optimal initial optical axis angle from multiple optical axis angles that avoids or mitigates the effects of received non-signal light other than received signal light received by the light receiving unit.Therefore, when the light transmitter / receiver and the reflector are installed opposite each other with a monitored space in between, 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 (which may include received non-signal light in addition to received signal light) for each of multiple mutually different optical axis angles, and the optical axis angle extraction unit extracts the optimal initial optical axis angle from the determination result.By setting this optimal initial optical axis angle, it is possible to avoid or mitigate the effects of reflective obstacles, external light disturbances, etc. that cause received non-signal light to be affected during fire monitoring.

[0016] (Effect of extracting optimal initial optical axis angle based on reference correlation) Further, the correlation determination unit registers in advance the correlation between the amount of transmitted light and the amount of received light determined for each optical axis angle in a state not influenced by the received non-signal light as a reference correlation, and the optical axis angle extraction unit extracts, from the correlations between the amount of transmitted light and the amount of received light determined by the correlation determination unit for each optical axis angle, an optical axis angle of a correlation that matches the corresponding reference correlation or has the smallest deviation from the reference correlation within a predetermined allowable angle range, as an optimal initial optical axis angle.Therefore, by extracting and setting, from the correlations determined for each of a plurality of mutually different optical axis angles, an optical axis angle at which it is determined that the correlation matches the reference correlation, which is a correlation in a state not influenced by the received non-signal light, or has the smallest deviation from the reference correlation, it is possible to avoid or mitigate the effects of reflective obstacles, external light, and the like that cause received non-signal light to be affected during fire monitoring.

[0017] (Effect of extracting the optimal initial optical axis angle based on vertical and / or horizontal optical axis angle adjustment) In addition, the transmitting optical axis of the transmitted signal light to the reflector of the light transmitting section and the receiving optical axis of the received signal light received from the reflector by the light receiving section are in a parallel relationship, and the optical axis adjustment section varies the optical axis angle of the transmitted light axis by rotating the direction of the transmitted light axis vertically and / or horizontally while maintaining the parallel relationship between the transmitted light axis and the received light axis, and the correlation determination section determines the correlation between the amount of transmitted light and the amount of received light at each optical axis angle by varying the optical axis angle of the transmitted light axis vertically and / or horizontally with the optical axis adjustment section, and determines the correlation between the amount of transmitted light and the amount of received light determined for each optical axis angle in a state not affected by the received non-signal light as a reference correlation. and registered in advance, and the optical axis angle extraction unit extracts, from the correlations between the amount of transmitted light and the amount of received light determined by the correlation determination unit for each optical axis angle, an optical axis angle of a correlation that matches a corresponding reference correlation or has a minimum deviation from the reference correlation within a predetermined allowable angle range, as an optimal initial optical axis angle.Therefore, when adjusting the optical axis angle vertically and horizontally, it is possible to extract and set an optimal initial optical axis angle that avoids or reduces the effects of reflective obstacles, external light disturbances, etc. that cause received non-signal light, for the range of the monitored space in all vertical and horizontal directions between the light transmitting and receiving unit and the reflector.

[0018] In addition, when beams, pipes, etc. that act as reflective obstacles to the monitored space are concentrated at a specific position relative to the monitored space, for example, above the monitored space, the optical axis angle adjustment is simplified by adjusting the optical axis angle only in the vertical direction, that is, up and down, and it is possible to extract and set an optimal initial optical axis angle that avoids or mitigates the effects of the reflective obstacles present above the monitored space.

[0019] (Effect of pre-registration of baseline correlations for different installation distances) In addition, the correlation determination unit is configured to pre-register reference correlations determined for each installation distance and each optical axis angle between a plurality of mutually different light transmitters / receivers and the reflector, making it possible to extract an optimal initial optical axis angle corresponding to the installation distance that differs depending on the building in which the devices are installed, etc.

[0020] (Effect of extracting the initial optical axis angle when multiple correlations are judged to match or have minimal deviation from the reference correlation) Furthermore, when a plurality of optical axis angles are determined within a predetermined allowable angle range as being in agreement with the reference correlation or having a correlation with a minimum deviation from the reference correlation, the optical axis angle extraction unit extracts the minimum optical axis angle or the optical axis angle with the maximum amount of light received by the light receiving unit as the optimal initial optical axis angle. Therefore, even when a plurality of optical axis angles are determined as being able to avoid or mitigate the influences of reflective obstacles, external light, and the like that cause received non-signal light, it is possible to extract and set the optimal initial optical axis angle from among them.

[0021] (Effect of the judgment process based on the proportionality coefficient) The correlation determination unit applies a proportional relationship between the amount of transmitted light of the transmitted signal light and the amount of received light of the light received by the light receiving unit as the correlation, and makes a determination based on a proportional coefficient of the proportional relationship, or applies a proportional relationship between the amount of transmitted light of the transmitted signal light and the amount of received light of the light received by the light receiving unit as the correlation, and makes a determination based on a proportional coefficient of the proportional relationship, and also applies a proportional relationship between the amount of transmitted light and the amount of received light in a state not affected by the received non-signal light as a reference correlation, and registers the proportional coefficient of the proportional relationship as a reference proportional coefficient in advance, and the optical axis angle extraction unit extracts a proportional relationship from a plurality of mutually different optical axis angles based on the plurality of proportional coefficients determined for each optical axis angle by the correlation determination unit, An optimal initial optical axis angle that avoids or mitigates the effects of received non-signal light is extracted, or, from among the proportional coefficients determined by the correlation determination unit for each optical axis angle, an optical axis angle having a proportional coefficient that matches a corresponding reference proportional coefficient or has a minimum deviation from the reference proportional coefficient within a predetermined allowable angle range is extracted as the optimal initial optical axis angle. Therefore, by applying a proportional relationship as the correlation between the amount of transmitted light and the amount of received light and making a determination based on the proportional coefficient of the proportional relationship, it is possible to appropriately and reliably extract and set an optimal initial optical axis angle that avoids or mitigates the effects of reflective obstacles, ambient light, and the like that cause received non-signal light.

[0022] The reason why a proportional relationship is applied as the correlation between the amount of light transmitted and the amount of light received in this manner, and a judgment is made based on the proportionality coefficient of this proportional relationship to set the optimal initial optical axis angle that avoids or mitigates the effects of reflective obstacles can be explained as follows.

[0023] 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.

[0024] 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. 11 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. 11 is, for example, made of transparent acrylic resin. FIG. 11 (A) shows a reflex reflector, and (B) shows a retroreflective element (corner cube) used in the reflex reflector.

[0025] 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.

[0026] In addition, since a reflective obstacle has different reflection characteristics from a reflector, the relationship between the amount of received non-signal light received by the light receiving unit and the distance between the light transmitter / receiver and the reflective obstacle generally differs from the relationship between the distance (installation distance) between the light transmitter / receiver and the reflector, and for example, the amount of received non-signal light received from the reflected non-signal light from the reflective obstacle is not inversely proportional to the fourth power of the distance between the light transmitter / receiver and the reflective obstacle. As an example, if the reflective obstacle is a mirror reflector having a reflective surface directly facing the light transmitter / receiver (perpendicular to the light transmitting optical axis and the light receiving optical axis), the amount of received non-signal light received from the reflected non-signal light from the reflective obstacle is inversely proportional to the square of "twice the distance" between the light transmitter / receiver and the reflective obstacle. In other words, in this case, the amount of received light is not inversely proportional to the fourth power of the distance.

[0027] Since the distance between the light transmitter / receiver and the reflector and the distance between the light transmitter / receiver and the reflective obstacle both affect the proportionality coefficient related to the correlation between the amount of light transmitted and the amount of light received, and many of the other elements that make up the proportionality coefficient also differ between the reflector and the reflective obstacle, when the light received by the light receiver is a combination of the received signal light from the reflector and the received non-signal light from the reflective obstacle, or when the light received by the light receiver is only the received non-signal light from the reflective obstacle, the proportionality coefficient related to the correlation (proportional relationship) between the amount of light transmitted and the amount of light received will be different from that when the light receiver receives only the reflected signal light from the reflector. Note that in many cases where disturbance light with time fluctuations, specifically, sunlight with fluctuating light or flickering illumination light, etc., is incident on the light receiver and received, the amount of light transmitted and the amount of light received are not proportional.

[0028] For this reason, when the proportionality coefficient is evaluated as indicating the correlation between the amount of transmitted signal light and the amount of light received by the light receiving unit for each of a number of mutually different optical axis angles of the transmitted signal light, the proportionality coefficient at the optical axis angle that is not influenced by a reflective obstacle will match the reference proportionality coefficient, and the proportionality coefficient at the optical axis angle that is influenced by a reflective obstacle will be a different proportionality coefficient that is greater than the reference proportionality coefficient, for example. Therefore, by comparing the proportionality coefficient with the reference proportionality coefficient, it can be determined whether the optical axis angle is influenced by a reflective obstacle or whether it is an optical axis angle that is not influenced by a reflective obstacle or is only influenced by a reflective obstacle. By extracting, determining, and setting this as the optimal initial optical axis angle, it is possible to avoid or mitigate the influence of reflected non-signal light from reflective obstacles during fire monitoring.

[0029] (Effect of adjusting the optical axis of a dimming reflective smoke detector) The effects of the invention relating to the optical axis adjustment method for 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.

[0030] (Effect of dimming reflective smoke detection system) A dimming reflective smoke detection system equipped with a dimming reflective smoke detector has a correlation determination unit and an optical axis angle extraction unit that can be provided in, for example, an external device connected to the dimming reflective smoke detector, thereby distributing the processing required for optical axis adjustment and reducing the processing burden on the dimming reflective smoke detector. [Brief description of the drawings]

[0031] [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 showing a fire monitoring state affected by a reflective obstacle other than a reflector. [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. 13 is a conceptual explanatory diagram showing adjustment of the optical axis angle in the vertical and horizontal directions of the light transmitter / receiver. [Figure 6] 4 is an explanatory diagram showing a state in which a transmission signal light from a light transmitting unit is irradiated onto a reflector. FIG. [Figure 7] FIG. 11 is an explanatory diagram showing the installation distance and optical axis angle for determining the proportionality coefficient. [Figure 8] 11 is an explanatory diagram showing, in a table format, reference proportional coefficient information registered in correspondence with installation distances and optical axis angles; FIG. [Figure 9] 13 is an explanatory diagram showing extraction of an optimal initial optical axis angle by comparing a determined proportionality coefficient with a reference proportionality coefficient. FIG. [Figure 10] 11 is a flowchart showing an optical axis angle adjustment operation. [Figure 11] 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

[0032] Hereinafter, embodiments of a light-reducing reflective smoke detector, a light axis adjustment method thereof, and a light-reducing reflective smoke detection system according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the following embodiments.

[0033] [Basic Concept of the Embodiment] First, the basic concept of the embodiment will be described. The embodiment generally relates to a dimming reflective smoke detector and an optical axis adjustment method for the initial setting thereof. Note that the "initial setting" is not limited to when the dimming reflective smoke detector is installed, but may be performed as necessary after the start of operation. In the embodiment, as part of the optical axis adjustment for the initial setting, an "optical axis angle adjustment" is performed that extracts and sets an optimal initial optical axis angle that avoids or reduces the influence of received non-signal light.

[0034] 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)."

[0035] 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.

[0036] 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.

[0037] 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."

[0038] 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." "Non-signal light" also includes disturbance light caused by direct or reflected sunlight or illumination light that is received by the light-receiving unit, "reflected non-signal light" includes disturbance light that is reflected by reflectors or reflective obstacles, and "received non-signal light" is a concept that includes the disturbance light received by the light-receiving unit.

[0039] 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."

[0040] The dimming type reflective smoke detector of the embodiment is equipped with an optical axis adjustment unit, a correlation determination unit, and an optical axis angle extraction unit so that the optical axis can be adjusted (set) to an angle that reduces or mitigates the influence of received non-signal light due to non-signal light such as reflected non-signal light from a reflective obstacle or disturbance light.

[0041] The "optical axis adjustment unit" varies the optical axis angle of the transmitting optical axis of the transmitting signal light relative to the reflector, and the "correlation determination unit" determines the correlation between the amount of transmitting signal light from the light transmitting unit and the amount of light received by the light receiving unit for each of a plurality of mutually different optical axis angles, and the light received by the light receiving unit may include received non-signal light in addition to received signal light. The "optical axis angle extraction unit" extracts an optimal initial optical axis angle that avoids or reduces the influence of received non-signal light, i.e., the influence of reflected non-signal light from a reflective obstacle or the influence of disturbance light, from a plurality of mutually different optical axis angles based on a plurality of determination results determined for each optical axis angle by the correlation determination unit.

[0042] Here, the "light transmission optical axis" refers to the optical axis of the light transmission signal light transmitted from the light transmitting unit to the reflector. In addition to the "light transmission optical axis", there is also the "reflected light axis" of the reflected signal light that is reflected by the reflector from the light transmission signal light, and the "received light optical axis" of the received signal light that is received by the light receiving unit. It is possible to adjust the angles of the "transmitting optical axis," "reflected optical axis," and "receiving optical axis" individually, but in an embodiment serving as an example of the present invention, the transmitting unit and the receiving unit are integrally arranged (fixed) on an optical table so that the transmitting optical axis and the receiving optical axis are macroscopically close to each other while being parallel, and the angle of the transmitting optical axis can be adjusted while maintaining the parallel relationship between the transmitting optical axis and the receiving optical axis, and when the reflector reflects the transmitting signal light, the main component of the reflected signal light has the property (reflexivity) of being reflected in the incident direction, i.e., along the transmitting optical axis (reflected signal light mainly composed of such reflected light also has a slight spread angle, so that a portion of the reflected signal light can be received by the receiving unit adjacent to the transmitting unit).

[0043] The reflector exhibits sufficient reflectivity for the incidence of the transmitted signal light in an angle range equal to or wider than the optical axis angle range (adjustment range) that can be changed by the optical axis adjustment unit provided on the light transmitter / receiver side, and for this reason, the angle adjustment mechanism is omitted on the reflector side in this embodiment. However, this invention does not exclude the provision of a configuration in which the angle of the reflector can be adjusted, for example, by using a reflector mounting base provided with an angle adjustment mechanism.

[0044] From the above, in the embodiment, the "reflected light axis" and the "received light axis" are determined by the "transmitting light axis", and the three light axes can be considered to be the same. That is, in the embodiment, "varying the light axis angle" means "varying the light axis angle of the transmitting light axis" and also means "varying the light axis angles of the transmitting light axis, the reflected light axis, and the receiving light axis together". In other words, "varying the light axis angle of the transmitting light axis" in the claims is a concept that includes "varying the light axis angle of the transmitting light axis" and "varying the light axis angles of the reflected light axis and the receiving light axis together with the light axis angle of the transmitting light axis".

[0045] The "correlation determination unit" preregisters as a reference correlation a correlation between the amount of transmitted light and the amount of received light determined for each optical axis angle in a state not affected by received non-signal light, i.e., in a state not affected by reflective obstacles, disturbance light, etc., and the concept of "not affected" here includes a state in which the influence is sufficiently small. More specifically, the registration of the reference correlation by the correlation determination unit preregisters as reference correlations a correlation between a plurality of amounts of transmitted light and a plurality of amounts of received light determined for each installation distance between a plurality of mutually different light transmitter / receivers and reflectors and for each optical axis angle in a state not affected by received non-signal light, and makes it possible to identify a corresponding reference correlation from the registered reference correlations based on the installation distance in the installed monitored space and the optical axis angle adjusted by the optical axis adjustment unit.

[0046] The correlation between the amount of light transmitted and the amount of light received when the amount of light received at the light receiving unit is not affected by the received non-signal light matches the corresponding reference correlation registered in advance, but the correlation when the effect of the received non-signal light becomes large becomes more deviant from the reference correlation. Therefore, the "optical axis angle extraction unit" extracts, as the optimal initial optical axis angle, an optical axis angle that matches the corresponding reference correlation or has the smallest deviation from the reference correlation from within a predetermined allowable angle range, for example, an angle range in which there is no problem with fire detection and there is still tolerance (room to ensure fire detection performance even if such optical axis changes occur) for optical axis deviation (natural change in optical axis) from the start of operation until a failure occurs, from among the correlations determined by the correlation determination unit for each optical axis angle. The "match" referred to here includes, for example, a case where the correlation roughly matches (approximately matches) including a predetermined error, etc.

[0047] Furthermore, when multiple optical axis angles are determined within a predetermined allowable angle range to match the reference correlation or to have a correlation that has a minimum deviation from the reference correlation, the "optical axis angle extraction unit" extracts the minimum optical axis angle or the optical axis angle at which the amount of light received by the light receiving unit is maximum as the optimal initial optical axis angle.

[0048] Also, 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 a determination is made based on the "proportionality coefficient." This utilizes the fact that, in a state where the installation distance between the light transmitting / receiving device and the reflector is fixed and the optical axis angle is set to an arbitrary angle (temporarily or permanently fixed), when the influence of the received non-signal light 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.

[0049] Similarly, when the amount of light received by the light-receiving unit is affected by non-signal light reflected from a reflective obstacle with the installation distance fixed and the optical axis angle set to an arbitrary value, the amount of light transmitted and the amount of light received are proportional to each other, but the proportionality coefficient in this case is different from the proportionality coefficient when there is no influence of non-signal light reflected from a reflective obstacle. Note that, for example, in most cases when the light-receiving unit receives disturbance light that varies over time, the amount of light transmitted and the amount of light received are not proportional to each other.

[0050] Here, the "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 plotted as a straight line with a positive slope.

[0051] Furthermore, when "correlation" is taken to be a "proportional relationship" and its index (subject to be analyzed, subject to judgment) is taken to be a "proportional coefficient," the correlation judgment unit makes a judgment based on the proportional coefficient and pre-registers the proportional coefficient of the proportional relationship between the amount of transmitted light and the amount of received light in a state not influenced by received non-signal light as a reference proportional coefficient as (an index indicating) the reference correlation, and the optical axis angle extraction unit extracts, from the proportional coefficients judged by the correlation judgment unit for each optical axis angle, the optical axis angle having a proportional coefficient that matches the corresponding reference proportional coefficient or has a minimum deviation from the reference proportional coefficient within a predetermined allowable angle range, as an optimal initial optical axis angle.

[0052] Moreover, the optical axis adjustment unit varies the optical axis angle of the transmitting light axis by rotating the direction of the transmitting light axis vertically and / or horizontally while maintaining the parallel relationship between the transmitting light axis and the receiving light axis, and the correlation determination unit varies the optical axis angle while temporarily fixing it vertically and / or horizontally at predetermined angle steps by the optical axis adjustment unit, and determines the correlation between the amount of transmitted light and the amount of received light at each optical axis angle, and the optical axis angle extraction unit extracts, from the correlation between the amount of transmitted light and the amount of received light determined for each optical axis angle by the correlation determination unit, an optical axis angle that matches a corresponding reference correlation or has a minimum deviation from the reference correlation within a predetermined allowable angle range, as an optimal initial optical axis angle.

[0053] Here, which directions are "vertical" and "horizontal" can be determined arbitrarily, but for example, the "vertical direction" and the "horizontal direction" are orthogonal to each other, and "horizontal" refers to varying the optical axis angle so as to rotate around an axis (conveniently called the "vertical axis") perpendicular to the ground (surveyed space floor), and "vertical" refers to varying the optical axis angle so as to rotate around an axis (conveniently called the "horizontal axis") perpendicular to the vertical axis with respect to the ground. The optical axis angle range (adjustment range) and angle step for "vertical" and "horizontal" can be arbitrary, and for example, when reflective obstacles are not present at the bottom of the monitored space but are concentrated at the top, the optical axis angle may be varied in the vertical direction on the upper side of the monitored space and the lower side may be omitted in order to simplify the optical axis adjustment. Alternatively, for example, the angle step may be made finer (the angle per step is made smaller) in the vertical direction on the upper side and coarse in the vertical direction on the lower side. Furthermore, the variation of the optical axis angle by the optical axis adjustment unit does not prevent the omission of either the "vertical rotation" or the "horizontal rotation."

[0054] The scope of the present invention also extends to a dimming reflective smoke detection system equipped with a dimming reflective smoke detector. The dimming reflective smoke detection system includes certain components other than the dimming reflective smoke detector as components of the system, and the optical axis adjustment unit, correlation determination unit, and optical axis angle extraction unit are provided in any of the components of the system. For example, the correlation determination unit and optical axis angle extraction unit may be provided in an external device such as a PC that can be connected to the dimming reflective smoke detector via a certain communication cable, so that the correlation determination and initial optical axis angle extraction processes may be performed by the external device.

[0055] In the following, a specific embodiment will be described. In the embodiment, the case will be described where 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", the "light transmitting element of the light transmitting unit" is a "light emitting diode (LED)", the "light receiving element of the light receiving unit" is a "photodiode (PD)", and the "optical axis adjustment unit" is an "optical axis angle adjustment mechanism that adjusts the light transmitting optical axis, the reflected optical axis, and the light receiving optical axis together".

[0056] [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. Adjusting the angle of the optical axis to avoid or mitigate the effects of reflective obstacles d1. Correlation determination section d2. Determination of proportionality coefficient d3. Pre-registration of standard proportionality coefficient d4. Extraction of optimal initial optical axis angle e. Optical axis adjustment operation of dimming reflective type smoke detector e1: Installation of the transmitter / receiver and reflector and preliminary adjustment of the optical axis angle e2. Optical axis angle adjustment operation f. Modifications of the present invention

[0057] [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.

[0058] 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.

[0059] 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 direction of rotation (rotation) of the Z axis on the Y axis or the Y axis on the Z axis is the up-down rotation (vertical rotation) is called "vertical rotation" (first rotation direction), and the direction of rotation (rotation) of the X axis on the Z axis or the Z axis on the X axis is called "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, 4 to 7 which show the embodiments of the present invention.

[0060] 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.

[0061] 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. 11 as described above. Here, "retroreflection" refers to the property of reflecting incident light generally in the direction of incidence. In addition, in the embodiment, the reflector 12 having retroreflection has a performance of maintaining 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 the embodiment, the installation angle adjustment mechanism of the reflector 12 is omitted.

[0062] 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 transmits light transmission signal light 15a intermittently from the light transmitting unit 14 at a predetermined light transmission timing, for example, at a cycle of 2 seconds, and detects attenuation in the amount of light received by the light receiving unit 16 receiving reflected signal light 15b reflected by the reflector 12 in synchronization with this light transmission timing 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).

[0063] 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.

[0064] [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.

[0065] 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.

[0066] 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).

[0067] For this reason, when installing the light transmitter / receiver 10 and reflector 12 of the dimming reflective smoke detector 1, it is necessary to avoid as much as possible the presence of reflective obstacles 20 such as beams and ducts inside a building in the monitored space 11, particularly in the irradiation range of the transmitted signal light 15a between the light transmitter / receiver 10 and reflector 12, so as to avoid the influence of the reflective obstacles 20, and the optical axes of each signal light are adjusted and initially set so as to obtain a predetermined initial light receiving amount that allows appropriate detection of attenuation of the reflected signal light 15b due to fire smoke. However, in the past, even after adjusting the optical axes, confirmation that there is no influence of the reflective obstacles 20 in the monitored space 11 where no fire smoke is generated was limited to visually checking the positional relationship between the light transmitter / receiver 10, the reflector 12, and the reflective obstacles 20, which was not sufficiently reliable.

[0068] Therefore, in the optical axis adjustment of the dimming reflective smoke detector 1 of this embodiment, an optical axis angle adjustment function is provided that makes it possible to set the optimal initial optical axis angle that avoids or mitigates the effects of the reflective obstacle 20.

[0069] [c. Configuration of dimming reflective smoke detector] Next, the configuration of an embodiment of a dimming reflective smoke detector according to the present invention having an optical axis angle adjustment function that allows the optimum initial optical axis angle to be set to avoid or mitigate the influence of reflective obstacles will be described. In this description, reference will be made to Fig. 3 showing an embodiment of the dimming reflective smoke detector.

[0070] As shown in FIG. 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 memory unit 26, and an operation display unit .

[0071] 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.

[0072] 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.

[0073] 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 the time of a fire at various assumed installation distances (i.e., the installation distance between the light transmitting / receiving unit 10 and the reflector 12), 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.

[0074] The light transmission driver 34 drives the light transmitting element 36 to emit light for a predetermined period of time at a predetermined light transmission timing, for example, to emit pulsed light to perform intermittent light transmission, in response to a control signal from the light transmission control unit 42 of the control unit 24. The period of the intermittent light transmission and the light transmission time in one period are arbitrary, but for example, the intermittent light transmission is set to repeat a light transmission time (light transmission pulse) of 100 microseconds in a 2 second period.

[0075] 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 .

[0076] 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.

[0077] 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 optical axis of light transmitted from the light transmitting unit 14 and the optical axis of light received by the light receiving unit 16 are parallel to each other.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] The control unit 24 mainly performs predetermined processing for fire 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.

[0084] 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.

[0085] 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.

[0086] In addition, the light receiving control unit 44 is provided with a correlation determination unit 48 and an optical axis angle extraction unit 50 for adjusting the optical axis angle of the dimming reflective smoke detector 1 and setting it to an optimal initial optical axis angle, and is also provided with a fire determination unit 52 for fire monitoring during operation after the adjustment (setting) of the initial optical axis angle is completed.

[0087] The fire determination unit 52 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 52 is arbitrary, but it determines whether or not there is a fire based on the attenuation state, for example, the attenuation rate D [%] of the amount of received light that increases due to smoke.

[0088] The determination based on the light attenuation rate D of the fire determination unit 52 is initialized so that an appropriate initial light reception amount can be obtained by storing the initial light reception amount Pr received by the light receiving unit 16 during the optical axis adjustment as a reference light reception amount Pro in the memory unit 26, and the light attenuation rate D is calculated using the initially set reference light reception amount Pro each time the light reception amount Pr received by the light receiving unit 16 during fire monitoring is read as light reception data. 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 54 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.

[0089] 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.

[0090] The fire determination unit 52 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 amount of received light Pr and the initially set reference amount of received light Pro. S = (Pr / Pro) x 100 [%] The value is calculated as follows, and is between the light extinction rate D [%] and 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 54 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.

[0091] The storage unit 26 stores information used for processing in the light transmitter / receiver 10. The information stored in the storage unit 26 includes the installation distance, the reference amount of received light Pro, reference proportional coefficient information (reference correlation information showing the correlation between the amount of transmitted light and the amount of received light) used to extract the optimum initial optical axis angle described below, and drive current information for controlling the light transmitter 14 when extracting the optimum initial optical axis angle, and other necessary information such as fire determination conditions for the fire determination unit 52 to determine a fire is also appropriately stored.

[0092] The operation display unit 28 performs operations necessary for adjusting the optical axis angle of the dimming reflective smoke detector 1, fire monitoring, restoring the fire detection status, and other operations, and displays the fire monitoring status, fault status, fire occurrence status, etc., and outputs operation signals to the control unit 24 and the display is controlled by a display signal from the control unit 24.

[0093] The specific configuration of the operation and display unit 28 is arbitrary, but the operation unit may include a light transmission start switch or the like used when adjusting (setting) the initial optical axis angle, and the display unit may include LED indicator lights such as an indicator light showing the operation corresponding to the operation of the light transmission start switch, a monitoring indicator light that indicates, for example, by lighting up green when fire monitoring is in progress, a fault indicator light that indicates, for example, by lighting up yellow when a fault has occurred, and an alarm indicator light that indicates, for example, by lighting up red when a fire has occurred, a liquid crystal display device or the like for displaying the angle when adjusting the optical axis angle of the initial optical axis angle, and an indicator that displays the amount of received light may also be provided.

[0094] [d. Adjusting the optical axis angle to avoid or mitigate the effects of reflective obstacles] Next, an optimal adjustment of the initial optical axis angle (optical axis angle adjustment) for avoiding or mitigating the influence of reflective obstacles in adjusting the optical axis of a dimming reflective smoke detector will be described.

[0095] In order to adjust the optical axis angle of the dimming reflective smoke detector 1 and set it to an optimal initial optical axis angle that avoids or reduces the effects of reflective obstacles, a correlation determination unit 48 and an optical axis angle extraction unit 50 are provided in the light receiving control unit 44 in the control unit 24 of the light transmitter / receiver 10, as shown in FIG. 3.

[0096] (d1. Correlation determination section) First, the correlation determination unit 48 will be described. As shown in Fig. 1 and Fig. 2, when the light transmitting / receiving device 10 and the reflector 12 are installed opposite each other in the monitored space 11 and the optical axis angles of the signal lights are adjusted to an optimal initial optical axis angle, the correlation determination unit 48 rotates the direction of the optical axis by the optical axis adjustment unit 32 to adjust to a plurality of mutually different optical axis angles, and applies, for example, a proportional relationship between the amount of light transmitted Pe and the amount of received light Pr of the transmitted light as a correlation between the amount of light transmitted Pe and the amount of received light Pr of the transmitted light as a correlation between the amount of light transmitted Pe and the amount of received light Pr of the transmitted light for each optical axis angle (subject to be analyzed, subject to be determined), and determines a proportionality coefficient K as an index (subject to be analyzed, subject to be determined) of the proportional relationship between the amount of light transmitted Pe and the amount of received light Pr.

[0097] In addition, the adjustment of a plurality of mutually different optical axis angles by the optical axis adjustment unit 32 is performed by the vertical optical axis adjustment unit 3210 and the horizontal optical axis adjustment unit 3212 shown in FIG. 4, and the vertical optical axis angle shown in FIG. 5(A) and the horizontal optical axis angle shown in FIG. 5(B) are adjusted independently and judged based on the proportionality coefficient K.

[0098] Here, the light transmitting optical axis of the light transmitting signal light transmitted from the light transmitting unit 14 and the light receiving optical axis of the light receiving signal light received by the light receiving unit 16 are parallel to each other, and the distance between the light transmitting unit 14 and the light receiving unit 16, which are fixed integrally to the optical stand 30 of the light transmitting / receiving unit 10, is negligible compared to the installation distance between the light transmitting / receiving unit 10 and the reflector 12. Therefore, the light transmitting optical axis and the light receiving optical axis can be regarded as the same optical axis, and the center of vertical rotation of the light transmitting optical axis and the light receiving optical axis can be regarded as the vertical rotation axis 3214 of the vertical optical axis adjustment unit 3210, and the center of horizontal rotation can be regarded as the horizontal rotation axis 3216 of the horizontal optical axis adjustment unit 3212.

[0099] For this reason, Figures 5(A) and (B) show a virtual optical axis starting from the light transmitter / receiver 10 side and ending at the opposing wall surface on which the reflector 12 is installed, and the vertical rotation of the virtual optical axis shown in Figure 5(A) rotates around the vertical rotation axis 3214 and rotates two steps upward and two steps downward about the central axis 3218-0, while the horizontal rotation of the virtual optical axis shown in Figure 5(B) is shown in a conceptual diagram as rotating around the horizontal rotation axis 3214 and rotates two steps to the right and two steps to the left about the central axis 3218-0.

[0100] 5A shows a case where the optical base 30, to which the light transmitting unit 14 and the light receiving unit 16 of the light transmitting / receiving device 10 are integrally fixed, is rotated vertically in steps around the vertical rotation axis 3214 by manual or automatic adjustment of the optical axis adjustment unit 32, and the direction of the virtual optical axis rotates upward and downward (vertical) in steps of a predetermined angle unit around the vertical rotation axis 3214. Here, in the virtual optical axis, the optical axis angle θ at the position of the central axis 3218-0 is set to 0°, the optical axis angle (upward angle) at the central axes 3218-1 and 3218-2 when rotated vertically upward is a positive angle, and the optical axis angle (downward angle) at the central axes 3218-3 and 3218-4 when rotated vertically downward is a negative angle, and the optical axis angles of the light transmitting optical axis and the light receiving optical axis are adjusted in multiple steps within the upward angle range and downward angle range that can be adjusted by the optical axis adjustment unit 32.

[0101] 5(B) shows a case where the optical base 30, to which the light transmitting unit 14 and the light receiving unit 16 of the light transmitter / receiver 10 are integrally fixed, is rotated in steps horizontally around the horizontal rotation axis 3216 by manual or automatic adjustment of the optical axis adjustment unit 32, and the direction of the virtual optical axis is rotated in steps in predetermined angle units to the right and left (horizontal) around the horizontal rotation axis 3216. Here, the optical axis angle φ at the position of the central optical axis 3218 is set to 0° (center), the optical axis angles (rightward angles) at the central axes 3218-5 and 3218-6 when rotated horizontally to the right are set to positive angles, and the optical axis angles (leftward angles) at the central axes 3218-7 and 3218-8 when rotated horizontally to the left are set to negative angles, and the optical axis angles of the light transmitting optical axis and the light receiving optical axis are adjusted in multiple steps within the rightward angle range and the leftward angle range that can be adjusted by the optical axis adjustment unit 32.

[0102] (d2. Judgment based on proportionality coefficient) Next, the determination based on the proportionality coefficient by the correlation determination unit 48 will be described. In order to perform the determination based on the proportionality coefficient, the amount of light transmission Pe of the transmitted signal light is changed within a predetermined range with the optical axis angle set to a predetermined angle among the multiple adjustable stages of optical axis angles, and the amount of light reception Pr received by the light receiving unit 16 is detected accordingly. The optical axis angle set here may be set within an angle range that does not interfere with fire detection and also leaves a tolerance (room to ensure fire detection performance even if such an optical axis change occurs) for optical axis deviation (natural change in the optical axis) until a failure occurs after the start of operation.

[0103] In making a judgment based on the proportionality coefficient in the correlation judgment unit 48, 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 an amount of light transmission at which a reference amount of received light Pro is obtained at the light-receiving unit 16, are stored in the storage unit 26 as 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. Then, upon receiving an operation signal from the light-transmission start switch of the operation and display unit 28, the correlation judgment unit 48 reads out the drive current information from the storage unit 26 and transmits it to the light-transmission control unit 42, and the light-transmission control unit 42 outputs a control signal to the light-transmission drive unit 34 to intermittently flow a light-emitting current that increases in stages from a current value that is, for example, a minimum value, from the light-transmission drive unit 34 to the light-transmitting element 36, thereby increasing the amount of light transmission Pe of the transmitted signal light in stages.

[0104] At this time, the correlation determination unit 48 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 optical axis adjustment can be shortened.

[0105] Next, correlation determination unit 48 uses the stepwise increased amounts of transmitted light 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 amounts of emitted light and received light are proportional to each other, and calculates the proportionality coefficient K if it is determined that they are proportional.

[0106] 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.

[0107] 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, each time the amounts of received light Pr(3), Pr(4), Pr(n) are detected, the proportionality coefficient at each stage is calculated. 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.

[0108] (d3. Pre-registration of standard proportionality coefficient) Next, the pre-registration of the reference proportionality coefficient used to extract the optimal initial optical axis angle will be described. In this description, reference will be made to Fig. 6, which shows the light transmission state from the light transmitting unit to the reflector, Fig. 7, which shows the installation distance and optical axis angle for making a judgment based on the proportionality coefficient, and Fig. 8, which shows the reference proportionality coefficient information registered in a table format corresponding to the installation distance and optical axis angle.

[0109] The correlation determination unit 48 preregisters the correlation between the amount of light transmission Pe and the amount of light reception Pr determined for each optical axis angle in a state where there is no influence of a reflective obstacle as a reference correlation, and the optical axis angle extraction unit 50 extracts, as an optimal initial optical axis angle, an optical axis angle of a correlation that matches the corresponding reference correlation or has a minimum deviation from the reference correlation among the correlations between the amount of light transmission Pe and the amount of light reception Pr determined by the correlation determination unit 48 for each optical axis angle. For this reason, in an embodiment in which a proportional relationship is applied as a correlation, the correlation determination unit 48 determines in advance a proportional coefficient that is an index (analysis target, determination target) of the proportional relationship that is a reference necessary for the optical axis angle extraction unit 50 to extract the optimal initial optical axis angle as a reference proportional coefficient, and preregisters it by storing it in the storage unit 26 as reference proportional coefficient information.

[0110] Here, the amount of light received at the light receiving unit due to differences in the light transmission state from the light transmitting unit to the reflector will be explained. As shown in Fig. 6, the light transmission signal light from the light transmitting unit 14 of the light transmitting / receiving unit is transmitted toward the reflector 12 (12-1) installed at a distance L from the light transmitting / receiving unit while spreading in a cone shape with a predetermined half-value angle α, for example α = 1°, and is reflected by the reflector 12 (12-1) and the reflected signal light is received as a received signal light by the light receiving unit of the light transmitting / receiving unit. The light intensity distribution 1510 in the vertical direction of the irradiation image 15 of the light transmission signal light transmitted to the reflector 12 (12-1) peaks at the center of the irradiation image 15 and gradually attenuates as it moves away from the center, forming a quadratic curve. For this reason, when the optical axis of light transmitted from the light transmitting unit 14 is located at the center of the reflector as in the reflector 12 (12-1), the amount of light received by the light receiving unit 16 is maximum, and the more the optical axis of light transmitted is shifted from the center of the reflector, the lower the amount of light received by the light receiving unit 16. Also, while the transmitted signal light can be reflected by the reflector and received as received signal light by the light receiving unit 16 as long as it is within the range of the irradiation image 15 of the transmitted signal light, as shown in the reflectors 12 (12-1) and 12 (12-3), the amount of light received by the light receiving unit 16 also decreases when it is shifted from the center of the irradiation image 15.

[0111] The pre-registration of the reference proportionality coefficient by the correlation determination unit 48 is carried out, for example, at the stage of designing and manufacturing a dimming reflective smoke detector, by installing the transmitter / receiver 10 and the reflector opposite each other in a space that is not affected by reflective obstacles, as shown in FIG. 7, and installing the reflector at different installation distances from the transmitter / receiver as shown, for example, in reflectors 12 (12-11), 12 (12-12), and 12 (12-13), as L1, L2, and L3, and varying the optical axis angle of the transmitting optical axis of the transmitted signal light in five stages, for example, vertically from θ1 to θ5, and calculating the proportionality coefficient for each installation distance and for each optical axis angle by the correlation determination unit 48. Reference proportionality coefficient information is then generated and stored in the memory unit 26, as shown in FIG. 8.

[0112] Here, the optical axis angles θ1 to θ5 are arbitrary, but for example, θ1 is set to 0° as a reference, θ2 is set to +0.5°, θ3 is set to +1.0°, θ4 is set to -0.5°, and θ5 is set to -1.0°, with the upward angle around the vertical being set to + and the downward angle being -, and the optical axis of the transmitted signal light with the optical axis angle θ1 (=0°) is perpendicular to the center of the reflecting surface of the reflectors 12 (12-11), 12 (12-12), and 12 (12-13). In addition, the installation distance that is set as a condition when generating the reference proportional coefficient information is arbitrary, and may be set to a plurality of installation distances that are changed within the range of the installation distance that can be monitored by the dimming reflective smoke detector, for example, from the minimum installation distance to the maximum installation distance in increments of 5 m or 10 m.

[0113] Although the reference proportional coefficient information is generated by varying the optical axis angle vertically in the description of FIGS. 7 and 8, the reference proportional coefficient information is generated by varying the optical axis angle horizontally in the same manner.

[0114] Also, the reference proportional coefficient information may be generated for only one of the vertical and horizontal directions. Also, instead of generating the reference proportional coefficient information by varying the optical axis angle in either the vertical or horizontal direction, the reference proportional coefficient information may be generated by simultaneously varying both the vertical and horizontal directions to determine the optical axis angle. In other words, in this case, the reference proportional coefficient information is generated by assuming that the item of the optical axis angle in FIG. 8 includes two parameters, the optical axis angle θ1 in the vertical direction and the optical axis angle φ1 in the horizontal direction, for example, θ1, φ1.

[0115] (d4. Extraction of optimal initial optical axis angle) Next, extraction of the optimal initial optical axis angle by the optical axis angle extraction unit 50 will be described. In this description, reference will be made to FIG. 9, which shows extraction of the optimal initial optical axis angle by comparing the proportionality coefficient determined by installing the light transmitting / receiving device and the reflector opposite each other across the monitoring space with the reference proportionality coefficient. Note that FIG. 9 shows an example of extraction of the optimal initial optical axis angle based on the reference proportionality coefficient information when the optical axis angles are θ1 to θ3 at the installation distance L1 in FIG. 7, and FIG. 9(A) shows a graph of a straight line with a slope of the reference proportionality coefficients K11 to K13 corresponding to the optical axis angles θ1 to θ3, FIG. 9(B) shows a graph in which the proportionality coefficients determined at all optical axis angles and the reference proportionality coefficients match, and FIG. 9(C) and (D) show graphs in which the determined proportionality coefficients and the reference proportionality coefficients match at some optical axis angles and deviate at other optical axis angles.

[0116] 9(A) is a linear graph with the slope of the reference proportional coefficients K11, K12, and K13 when the optical axis angles are θ1 to θ3 at the installation distance L1, and since the light-sending optical axis is perpendicular to the center of the reflecting surface of the reflector 12 (12-11) at the optical axis angle θ1, the amount of light received by the light-receiving unit is maximum and the proportional coefficient K11 is also maximum. On the other hand, since the upward angle increases sequentially as the optical axis angles become θ2 and θ3, the light-sending optical axis hits the reflecting surface of the reflector 12 (12-11) at an angle and the center of the reflecting surface deviates from the light-sending optical axis, so the amount of light received by the light-receiving unit decreases as the optical axis angles become θ2 and θ3, and the proportional coefficients K12 and K13 become successively smaller values.

[0117] 9(B) shows a case where a light transmitter / receiver and a reflector are installed facing each other in a monitored space and are not affected by reflected non-signal light from a reflective obstacle, and for each of the optical axis angles θ1, θ2, and θ3, the proportionality coefficient K determined by the correlation determination unit 48 when installed in the monitored space matches the corresponding reference proportionality coefficients K11, K12, and K13, respectively. Note that "matching" here is not limited to perfect matching, but has a range that is recognized as matching based on a predetermined judgment criterion.

[0118] In this way, when all the proportional coefficients determined for the optical axis angles θ1, θ2, and θ3 match the corresponding reference proportional coefficients, the optical axis angle extraction unit 50 extracts the optical axis angle θ1 that is the smallest among the optical axis angles θ1, θ2, and θ3, or the optical axis angle that maximizes the amount of light received by the light receiving unit when installed in the monitored space, as the optimal initial optical axis angle, and displays the extraction result on the operation display unit of the light transmitter / receiver. Therefore, when the initial optical axis angle is set manually, the operator adjusts and sets it to the extracted optimal initial optical axis angle, and when the initial optical axis angle is set automatically, the optical axis angle extraction unit 50 sets it based on the extraction result. The extraction result by the optical axis angle extraction unit 50 may be stored in the storage unit as a history.

[0119] 9(C) shows a case where the proportional coefficient determined at the optical axis angle θ1 installed in the monitored space matches the reference proportional coefficient, but deviates from it at the optical axis angles θ2 and θ3. At the optical axis angle θ1, the determined proportional coefficient K matches the reference proportional coefficient K11, so there is no influence of the non-signal light reflected from the reflective obstacle. On the other hand, at the optical axis angles θ2 and θ3, the determined proportional coefficient K deviates from the reference proportional coefficients K12 and K13. Therefore, the optical axis angle extraction unit 50 extracts the optical axis angle θ1 at which the determined proportional coefficient K matches the reference proportional coefficient K11 as the optimal initial optical axis angle, displays the extraction result on the operation display unit of the light transmitting / receiving device, and adjusts and sets the extracted optimal initial optical axis angle manually or automatically.

[0120] FIG. 9(D) shows a case where the proportional coefficient determined at the optical axis angles θ1 and θ2 after installation in the monitored space matches the reference proportional coefficient, but deviates from it at the optical axis angle θ3. At the optical axis angles θ1 and θ2, the determined proportional coefficients K match the reference proportional coefficients K11 and K12, so there is no influence of the non-signal light reflected from the reflective obstacle. On the other hand, at the optical axis angle θ3, the determined proportional coefficient K deviates from the reference proportional coefficient K13. Therefore, the optical axis angle extraction unit 50 extracts the optical axis angle θ1 at which the determined proportional coefficient matches the reference proportional coefficient, which is the smallest among the optical axis angles θ1 and θ2 at which the determined proportional coefficient matches the reference proportional coefficient, or the optical axis angle at which the amount of light received by the light receiving unit is maximized when the light transmitting / receiving unit is installed in the monitored space, as the optimal initial optical axis angle, displays the extraction result on the operation display unit of the light transmitting / receiving unit, and adjusts and sets the extracted optimal initial optical axis angle manually or automatically.

[0121] 9 shows an example of extraction of an optimal initial optical axis angle in an upward angle range in the vertical rotation of the light transmitting optical axis, but the optimal initial optical axis angle is extracted for optical axis angles θ1 to θ5 including a downward angle range as shown in the reference proportional coefficient information in Fig. 8. When extraction of the optimal initial optical axis angle in the vertical rotation is completed, the optimal initial optical axis angle in the horizontal rotation is extracted and set in a similar manner based on the reference proportional coefficient information preregistered for the optical axis angle in the horizontal rotation, with the initial optical axis angle in the vertical rotation set.

[0122] Here, since reflective obstacles such as beams and ducts that affect the amount of light received by the light receiving unit are often present above the monitored space 11, an optimal initial optical axis angle that avoids or reduces the influence of reflective obstacles may be extracted and set for the vertical upward angle range as shown in FIG. 9, which simplifies the extraction of the initial optical axis angle.

[0123] In addition, when adjusting the optical axis angle in the vertical and horizontal directions, the optimal initial optical axis angle in the vertical direction is extracted and set first, and then the optimal initial optical axis angle in the horizontal direction is extracted and set. However, when the optimal initial optical axis angle in the vertical direction is extracted and set, since the optical axis angle in the horizontal direction is not adjusted, the optical axis angle in the horizontal direction is adjusted to 0° or to a predetermined horizontal optical axis angle at which the peak value of the amount of received light is obtained at the horizontal optical axis angle, and then the optimal initial optical axis angle in the vertical direction is extracted and set.

[0124] Also, when adjusting the optical axis angles in the vertical and horizontal directions, the optimal initial optical axis angle in the horizontal direction may be extracted and set first, and then the optimal initial optical axis angle in the vertical direction may be extracted and set. In this case, when the optimal initial optical axis angle in the horizontal direction is extracted and set, since the optical axis angle in the vertical direction is not adjusted, the optical axis angle in the vertical direction is adjusted to 0°, or adjusted to a predetermined optical axis angle in the vertical direction at which the peak value of the amount of received light is obtained at the optical axis angle in the vertical direction, and then the optimal initial optical axis angle in the horizontal direction is extracted and set.

[0125] In addition, the optical axis angle adjustment may be performed by extracting and setting optimal initial optical axis angles in both the vertical and horizontal directions using reference proportionality coefficient information including two parameters, the optical axis angle in the vertical direction and the optical axis angle in the horizontal direction.

[0126] [e. Optical axis adjustment operation of dimming reflective smoke detector] Next, the optical axis adjustment operation of the dimming reflective smoke detector will be explained. In this explanation, the flow chart of Fig. 10 showing the optical axis angle adjustment operation will be referred to. Note that the "optical axis adjustment" includes the "pre-adjustment" performed before the "optical axis angle adjustment", and the "optical axis angle adjustment" is a part of the "optical axis adjustment".

[0127] (e1: Installation of the transmitter / receiver and reflector and preliminary adjustment of the optical axis angle) 1 and 2, prior to the optical axis angle adjustment operation in the flowchart of Fig. 10, the light transmitter / receiver 10 is installed on one wall or the like of the monitored space 11 in the building to be monitored, and the reflector 12 is installed on the wall or the like on the opposite side facing the light transmitter / receiver 10, based on a building plan or the like. After installation, the installation distance between the light transmitter / receiver 10 and the reflector 12 is measured by a predetermined distance measuring device, and the installation distance is input by operating the operation display unit 28 and stored in the memory unit 26. Note that the light transmitter / receiver 10 may be provided with a function as a distance measuring device, and may automatically measure by operating the operation display unit, and the measurement results may be stored in the memory unit 26.

[0128] Next, the optical axis angle is pre-adjusted by manual optical axis adjustment or automatic optical axis adjustment. Any method can be used for pre-adjusting the optical axis angle, but for example, a sight is used to adjust the optical axis so that the optical axis of the transmitted signal light transmitted from the light transmitting unit 14 of the light transmitting / receiving device 10 hits the center or its vicinity of the reflecting surface of the reflector 12. Next, a level meter or the like that displays the amount of received light is used to adjust the optical axis angle to the angle at which the peak value of the amount of received light is obtained at the light receiving unit 16 of the light transmitting / receiving device 10, thereby completing the pre-adjustment.

[0129] When the advance adjustment of the optical axis angle is completed, the light transmitter / receiver 10 is operated, the light transmitter 14 transmits a light transmission signal light at a predetermined light transmission timing, the light receiver 16 receives the reflected light signal light (light reception signal light) reflected by the reflector 12, and the amount of received light is stored in the memory 26 as the reference amount of received light (initial amount of received light) used for fire judgment. This makes the dimming reflective smoke detector 1 ready for fire monitoring, and then the optical axis angle adjustment operation of the flowchart in Fig. 10 is performed. At this time, the reference proportional coefficient information corresponding to the distance closest to the installation distance stored in the memory 26 is selected, and if drive current information is generated based on the reference amount of received light, the drive current information is generated and stored in the memory 26.

[0130] If an appropriate amount of light is not obtained as the reference amount of light, the installation angles of the light transmitter / receiver 10 and reflector 12 will be reviewed and adjusted again in advance.

[0131] (e2. Optical axis angle adjustment operation) As shown in FIG. 10, when the light transmitter / receiver 10 and the reflector 12 are installed and the preliminary adjustment of the light transmitting optical axis is completed, for example, in the case of manual adjustment, the vertical optical axis angles θ1 to θ5 in the reference proportional coefficient information shown in FIG. 8 stored in the memory unit 26 are read out and displayed on the liquid crystal display device of the operation display unit 28 (step S1).

[0132] Next, an arbitrary one of the displayed optical axis angles θ1 to θ5 is selected, and the optical axis angle of the selected vertically rotating light transmitting optical axis is set by manual operation (step S2). At this time, the horizontally rotating optical axis angle is fixed to the optical axis angle adjusted in advance. The order in which the optical axis angles θ1 to θ5 are selected is arbitrary, and for example, the optical axis angles are selected and set in ascending order of the optical axis angle or the descending order of the optical axis angle.

[0133] Next, by operating the light transmission start switch on the operation display unit 28, the light transmitting unit 14 transmits light with the amount of light transmission signal light changed stepwise based on the drive current information, the light receiving unit 16 receives the received light signal light, detects the amount of received light for the light transmission signal light with different amounts of light transmission, and determines the proportionality coefficient between the amount of light transmission and the amount of received light as an index of the proportional relationship between the amount of light transmission and the amount of received light (step S3). Next, the process of determining the proportionality coefficient while changing the vertical optical axis angle is repeated until the determination of the proportionality coefficient for all of the vertical optical axis angles θ1 to θ5 is completed (steps S4, S5, S3).

[0134] After the proportionality coefficients are determined for all the vertical optical axis angles, the proportionality coefficients determined for each optical axis angle are compared with the corresponding reference proportionality coefficients (step S6).

[0135] Then, when the proportionality coefficients for all vertical optical axis angles match and are the same as the reference proportionality coefficient, the optical axis angle at which the optical axis angle is smallest or the optical axis angle at which the maximum amount of light is received is extracted as the optimal initial optical axis angle and set as the extracted initial optical axis angle (steps S7, 11, 10).

[0136] Furthermore, when there is an optical axis angle whose proportionality coefficient does not match the reference proportionality coefficient but there is an optical axis angle whose proportionality coefficient matches the reference proportionality coefficient, the optical axis angle which is the smallest or the optical axis angle at which the maximum amount of received light is obtained is similarly extracted as the optimal initial optical axis angle and set to the extracted initial optical axis angle (steps S7, 8, 11, 10).

[0137] Furthermore, if the proportional coefficient does not match the reference proportional coefficient for all optical axis angles and there is no optical axis angle at which the proportional coefficient matches the reference proportional coefficient, i.e., if the proportional coefficient does not match the reference proportional coefficient for all optical axis angles and deviates from it, the optical axis angle at which the proportional coefficient deviates least from the reference proportional coefficient is extracted and set as the extracted initial optical axis angle (steps S7, 8, 9, 10).

[0138] When the optical axis angle adjustment for the vertical rotation is completed, the optical axis angle adjustment for the horizontal rotation is performed in the same manner as the vertical rotation (step S12), and a series of adjustment operations for the optical axis angle is completed. At this time, the optical axis angle for the vertical rotation is fixed to the initial optical axis angle set in the optical axis angle adjustment for the vertical rotation. Note that the optical axis adjustment operation in this flowchart may be performed by first setting the initial optical axis angle for the horizontal rotation, and then setting the initial optical axis angle for the vertical rotation.

[0139] In addition, when the proportional coefficient does not match the reference proportional coefficient at all optical axis angles and the degree of deviation exceeds a predetermined level at all optical axis angles, and when an optical axis angle matching the reference proportional coefficient cannot be found at the time of completing the optical axis angle adjustment operation in the vertical and horizontal directions, the fact is notified. Based on this notification, the optical axis angle adjustment operation is performed again by changing the installation positions of one or both of the light transmitting and receiving unit and the reflector.

[0140] In addition, the proportionality coefficients may be evaluated for all optical axis angles, both vertical and horizontal (the deviation between the calculated result and the reference proportionality coefficient is determined), and the smallest optical axis angle may be set as the initial optical axis angle. However, when an optical axis angle is found for which the deviation of the proportionality coefficient is determined to be sufficiently small, that optical axis angle may be set as the initial optical axis angle and the optical axis angle adjustment operation may be terminated.

[0141] [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.

[0142] 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).

[0143] In the above embodiment, one reflector is used, but a reflector having a predetermined size may be prepared, and when the installation distance is long, the number of reflectors arranged vertically and horizontally may be increased to increase the area of ​​the reflector. In this case, the proportionality coefficient takes into account the reflecting surface area of ​​the reflector. In consideration of such a case, the reference proportionality coefficient may be obtained not only for a plurality of installation distances but also for a plurality of reflecting surface areas.

[0144] In the above embodiment, the correlation determination unit of the dimming reflective smoke detector performs a determination based on a proportionality coefficient, and the optical axis angle extraction unit extracts an optimal initial optical axis angle that avoids or mitigates the effects of reflective obstacles. However, an external device such as a PC may be connected to the dimming reflective smoke detector via a specified communications cable, and the determination based on the proportionality coefficient and the extraction process of the optimal initial optical axis angle may be performed by the external device.

[0145] In the above embodiment, the optimal initial optical axis angle that avoids or reduces the influence of reflective obstacles is extracted and set, but the optimal initial optical axis angle that further avoids or reduces the influence of disturbance light, for example, other than reflective obstacles, may be extracted and set. Disturbance light fluctuates over time, so by adjusting the optical axis according to the time period when the influence of disturbance light is large, it is possible to avoid or reduce the influence of disturbance light as well.

[0146] (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]

[0147] 1: Dimmable reflective smoke detector 10: Transmitter / receiver 11: Surveillance space 12:Reflector 13: Signal cable 14: Light transmitting unit 15: Irradiation image 15a: Transmission signal light 15b: Reflected signal light 15c: Reflected non-signal light 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 3218-0~3218-8: Central 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 48: Correlation determination unit 50: Optical axis angle extraction part 52:Fire judgment department 54: Output section

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, an optical axis adjustment unit that changes an optical axis angle of the optical axis of the transmitted signal light relative to the reflector; a correlation determination unit that determines a correlation between an amount of the signal light transmitted and an amount of the light received by the light receiving unit for each of a plurality of mutually different optical axis angles; an optical axis angle extraction unit that extracts an optimal initial optical axis angle that avoids or reduces an influence of received non-signal light other than the received signal light received by the light receiving unit from the plurality of mutually different optical axis angles based on a plurality of determination results determined for each optical axis angle by the correlation determination unit; 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 an amount of transmitted light and an amount of received light determined for each optical axis angle in a state not affected by the received non-signal light; the optical axis angle extraction unit extracts, from the correlations between the amount of transmitted light and the amount of received light determined by the correlation determination unit for each optical axis angle, an optical axis angle that matches the corresponding reference correlation or has a minimum deviation from the reference correlation within a predetermined allowable angle range, as the optimal initial optical axis angle.

3. 2. The light-reducing reflective smoke detector according to claim 1, a light transmitting optical axis of the light transmitting signal light to the reflector of the light transmitting section and a light receiving optical axis of the light receiving signal light received from the reflector at the light receiving section are in a parallel relationship; the optical axis adjustment unit rotates a direction of the light transmitting optical axis vertically and / or horizontally while maintaining a parallel relationship between the light transmitting optical axis and the light receiving optical axis, thereby varying an optical axis angle of the light transmitting optical axis, the correlation determination unit determines a correlation between an amount of transmitted light and an amount of received light at each optical axis angle by varying an optical axis angle of the light transmitting optical axis in the vertical direction and / or the horizontal direction using the optical axis adjustment unit, and preregisters, as a reference correlation, the correlation between the amount of transmitted light and the amount of received light determined for each optical axis angle in a state not influenced by the received non-signal light, the optical axis angle extraction unit extracts, from the correlations between the amount of transmitted light and the amount of received light determined by the correlation determination unit for each optical axis angle, an optical axis angle that matches the corresponding reference correlation or has a minimum deviation from the reference correlation within a predetermined allowable angle range, as the optimal initial optical axis angle.

4. The light-reducing reflective smoke detector according to claim 2 or 3, A dimming reflective type smoke detector characterized in that the correlation determination unit pre-registers standard correlations determined for each installation distance between a plurality of different transmitters / receivers and the reflector and for each optical axis angle.

5. The light-reducing reflective smoke detector according to claim 2 or 3, a light receiving unit that receives a maximum amount of light from the light receiving section and detects a correlation between the light receiving section and the reference correlation and an optical axis angle extraction unit that detects a minimum amount of light from the light receiving section and detects a minimum optical axis angle when a plurality of optical axis angles are determined to match the reference correlation or have a minimum deviation from the reference correlation within the specified allowable angle range,

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; The optical axis angle extraction unit extracts an optimal initial optical axis angle that avoids or mitigates the received non-signal light from the multiple mutually different optical axis angles based on a multiple proportionality coefficient determined for each optical axis angle by the correlation determination unit.

7. The light-reducing reflective smoke detector according to claim 2 or 3, the correlation determination unit applies a proportional relationship between the amount of light transmitted by the signal light and the amount of light received by the light receiving unit as the correlation, and performs a determination based on a proportionality coefficient of the proportionality relationship, and applies a proportional relationship between the amount of light transmitted and the amount of light received in a state not affected by the received non-signal light as the reference correlation, and pre-registers a reference proportionality coefficient which is the proportionality coefficient of the proportionality relationship; the optical axis angle extraction unit extracts, from among the proportionality coefficients determined by the correlation determination unit for each optical axis angle, an optical axis angle having a proportionality coefficient that matches the corresponding reference proportionality coefficient or has a minimum deviation from the reference proportionality coefficient within the specified allowable angle range, as the optimal initial optical axis angle.

8. A method for adjusting an optical axis of 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 light from the light transmitter to the reflector, detecting attenuation of a light reception signal light received by a light receiver after the light transmission signal light is reflected by the reflector, and detecting the presence of smoke in the monitored space to detect a fire, comprising: an optical axis adjustment unit adjusts an optical axis angle of the optical axis of the transmitted signal light relative to the reflector; a correlation determination unit determines a correlation between an amount of the transmitted signal light and an amount of the light received by the light receiving unit for each of a plurality of mutually different optical axis angles; an optical axis angle extraction unit extracts an optimal initial optical axis angle that avoids or mitigates the influence of received non-signal light other than the received signal light received by the light receiving unit, from the multiple mutually different optical axis angles based on multiple judgment results determined for each optical axis angle by the correlation judgment unit,

9. A light-transmitting / receiving device having an integrated light-transmitting unit and a light-receiving unit 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 / receiving device, and the light-transmitting / receiving device is equipped with a light-receiving reflective smoke detector that transmits a light-transmitting signal light from the light-transmitting unit to the reflector, detects attenuation of a light-receiving signal light reflected by the reflector and received by the light-receiving unit to detect the presence of smoke in the monitored space and detect a fire, an optical axis adjustment unit that changes an optical axis angle of the optical axis of the transmitted signal light relative to the reflector; a correlation determination unit that determines a correlation between an amount of the signal light transmitted and an amount of the light received by the light receiving unit for each of a plurality of mutually different optical axis angles; an optical axis angle extraction unit that extracts an optimal initial optical axis angle that avoids or reduces an influence of received non-signal light other than the received signal light received by the light receiving unit from the plurality of mutually different optical axis angles based on a plurality of determination results determined for each optical axis angle by the correlation determination unit; A dimming reflective smoke detection system comprising:

10. 10. The light-reducing reflective smoke detection system according to claim 9, A dimming type reflective smoke detection system, characterized in that the correlation determination unit and the optical axis angle extraction unit are provided in an external device connected to the dimming type reflective smoke detector.

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