JP7515270B2 - Fire alarm system - Google Patents

Description

The present invention relates to a fire alarm system including a fire detector with an indicator light and a monitor device .

There are various types of fire detectors used in fire alarm systems installed inside buildings, such as heat detectors using thermistors, photoelectric smoke detectors, and flame detectors that have elements such as infrared sensors and detect flames by capturing light of wavelengths specific to flames. All types of fire detectors are equipped with an operation indicator light that shows that the detector has detected a fire and a status indicator light that shows a fault or other condition. Conventionally, the indicator light of a fire detector is often installed in one place on the surface of the detector using a point-type LED (light-emitting diode).
Such point-emitting type indicator lights have a directional visual appearance and cannot be seen depending on the direction you look at them. Therefore, unless the operation indicator light is installed facing the entrance in a position that can be seen when the entrance door is opened, it becomes difficult to check the operation of the detector when a fire is detected.

Therefore, in order to eliminate the visual directional nature of the indicator light, some detectors have multiple point-emitting type LEDs on the cover of the detector, or a point-emitting type LED is installed on the top of the detector, or, as in the invention of Patent Document 1, a circularly emitting indicator light is installed on the flat part of the detector cover. Such detectors are easy to install because there is no need to consider the relationship between the position of the indicator light and the position of the entrance/exit.
On the other hand, the fire detector's operation indicator light is designed to be turned off by a "recovery" switch provided on the receiver, so after operating the recovery switch, the detector that sent out the fire signal cannot be identified by its operation indicator light. However, there are some detectors that are able to memorize information that they have sent out a fire signal and turn the operation indicator light back on after the recovery switch is operated (see Patent Document 2).

JP 2007-188543 A JP 2017-134704 A

If a detector, like the one in Patent Document 1, were equipped with a function that stores information about the sending of a fire signal when it has sent it out and turns on the operation indicator light when necessary, there was a risk of confusion when a person other than the relevant parties found the operation indicator light turned on again, as they would assume that a fire had broken out or that the detector had been activated for a reason other than a fire. It was also revealed that some owners, fearing such confusion, did not want the detector's operation indicator light to be turned on except when there was a fire.
The present invention has been made against the background described above, and its object is to provide a fire alarm system including a fire detector and a monitor device which will prevent persons other than those involved from finding an indicator light that has been turned on again, causing confusion.
Another object of the present invention is to provide a fire alarm system including a fire detector and a monitor device , which can be constructed using parts common to fire detectors that do not have a fire detector that can store information about the past fire signal transmission and can re-illuminate the detector, thereby reducing costs.

In order to solve the above problems, the present invention relates to
A fire detector including a circuit board on which a fire detection circuit for detecting a fire is formed, a plurality of light sources connected to the circuit board, a housing for accommodating the circuit board and the plurality of light sources, and an indicator light that lights up by light from the light sources to provide an indication;
A monitor device for checking whether the indicator lamp is on or off;
A fire alarm system comprising:
At least one of the plurality of light sources of the fire detector is a first light source that emits visible light, and at least one of the light sources other than the first light source that emits visible light is a second light source that emits invisible light ,
The first light source is for detecting and indicating a fire,
The second light source is for displaying at least history information of fire detection,
The fire detector includes a storage means for storing, as a history, the fact that the fire detection circuit has detected a fire, a drive means for driving the plurality of light sources to light up or blink, and a control circuit for controlling the drive means, and the control circuit controls the drive means to light up or blink the second light source when fire detection history information is stored in the storage means upon receiving a recovery pulse,
The monitor device includes a detection means for detecting the invisible light emitted from the second light source, and a display means for displaying the detection result .

According to the above configuration, at least one of the multiple light sources is a light source that emits visible light, and at least one of the remaining light sources is a light source that emits invisible light, so that after the recovery switch is operated, the light source that emits invisible light is illuminated to relight the indicator light, i.e., to display the history, making it possible to easily find fire detectors that were activated before the recovery operation, and to prevent confusion caused by persons other than those involved finding the activated indicator light in a re-lit state. In addition, a fire detector that has the function of storing information that a fire signal has been sent in the past and relighting it to display the history can be constructed using parts that are common to fire detectors that do not have such a function, thereby reducing costs.

Here, the fire detector is equipped with a timer,
Upon receiving the restoration pulse, the control circuit controls the driving means to turn on or blink the second light source for a predetermined period of time measured by the timer .
Alternatively, the fire detector includes a timer,
The control circuit controls the driving means to turn on or blink the second light source only from the point when a first predetermined time measured by the timer has elapsed after receiving a recovery pulse until a second predetermined time measured by the timer has further elapsed.
According to the above-described configuration, after an alarm from the fire receiver, a supervisor or maintenance manager can patrol the area where each fire detector is installed within a specified period of time and check the operating status of the indicator light, thereby identifying the fire detector that detected the fire.
Furthermore, if any of the fire detectors makes an erroneous detection, even if a recovery operation is performed midway, the status indicator light will be lit, making it easy to identify the detector that made the detection due to a cause other than a fire.

Also, preferably, the light source that emits the invisible light is a light source that emits light of an infrared wavelength or an ultraviolet wavelength.
According to this configuration, the desired light source can be obtained relatively easily, so that a significant increase in the cost of the fire detector that would otherwise be required due to the addition of a history display function can be avoided.

Furthermore, the control circuit causes the second light source that emits the invisible light to light up or blink , based on a request to display a malfunction or a self-diagnosis result of the fire detector.
According to this configuration, the indicator light can indicate an activated state, which indicates that the detector has detected a fire, and can also indicate a state other than the activated state .

According to the present invention, it is possible to provide a fire detector that does not cause confusion when a person other than the relevant parties finds an indicator light in a relighted state to indicate the detector's status. In addition, there is no visual directional characteristic, meaning that it is possible to confirm from any direction whether the fire detector is activated or not. Furthermore, according to the present invention, a fire detector that stores information that a fire signal has been sent in the past and has the function of relighting the light can be constructed using parts that are common to fire detectors that do not have such a function, which has the effect of reducing costs.

1A and 1B show a first embodiment in which the present invention is applied to a smoke detection type fire detector, in which FIG. 2A is an exploded side view of the housing of the fire detector shown in FIG. 1 to show its constituent members, and FIG. 2B is a plan view of a main body case constituting the housing. FIG. 2 is a cross-sectional view showing an internal configuration of the fire detector of FIG. 1 . FIG. 2 is a perspective view showing a light guide member used in the fire detector of FIG. 1 . 5A, 5B and 5C show details of the light guide member of FIG. 4, in which FIG. 5A is a plan view, FIG. 5B is a cross-sectional view and FIG. 5C is a bottom view. FIG. 11 is a front cross-sectional explanatory view showing the configuration of a heat detector according to a second embodiment of the present invention. FIG. 11 is a perspective view showing a specific example of an element support member constituting the heat detector of the second embodiment. 2 is a block diagram showing a functional configuration of a circuit provided on a circuit board in the fire detector of FIG. 1 . 9 is a time chart showing an example of the operation of a fire alarm system using a fire detector having the circuit of FIG. 8 . 10 is a time chart showing a second operation example of the fire alarm system using the fire detector having the circuit of FIG. 8 . 10 is a time chart showing a third operation example of a fire alarm system using a fire detector having the circuit of FIG. 8 . 10 is a time chart showing a fourth operation example of the fire alarm system using the fire detector having the circuit of FIG. 8 . 1A and 1B are front and rear perspective views showing an example of the configuration of a monitor device for checking the lighting state of an invisible light operation indicator lamp constituting a fire detector of an embodiment. 14 is a perspective view showing a specific example of a lens portion constituting the monitor device of FIG. 13.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
Fig. 1 shows a first embodiment of the present invention when applied to a smoke detection type fire detector, where (a) is a plan view of the fire detector 10, (b) is a side view, Fig. 2(a) is a side view showing the state in which the housing of the fire detector 10 is disassembled, Fig. 2(b) is a plan view of the main body case 30, Fig. 3 is a cross-sectional view of the fire detector 10 taken along line A-A in Fig. 1, and Figs. 4 and 5 are diagrams showing specific examples of the light guide member constituting the fire detector 10 in Fig. 1. The fire detector 10 of this embodiment is designed to be installed on the ceiling surface of a building with the upper side (top side) of Fig. 1(b) facing downward. In the following description, the downward direction when installed on the ceiling surface of a building is described as upward.

1 and 2(a), the outer shell of the fire detector 10 of this embodiment is composed of a cover 11, a main case 30, a base 31, and a light guide member 20 sandwiched between the cover 11 and the upper end of the main case 30. The main case 30 is made of white resin, and as shown in Fig. 2(b), a circular opening 30b is formed in the center, and the cover 11 is attached to the top of the main case 30 so as to close this opening 30b.
As shown in Fig. 3, a smoke detector box 37 is housed inside the main body case 30 to form a smoke detector chamber 36. A circuit board 32 is attached to the base 31 with screws 38, and the circuit board 32 is housed in the internal space defined by the main body case 30 and the base 31. A light emitting element 33 and a light receiving element 34 are mounted on the circuit board 32 via lead wires, and an LED (light emitting diode) 35 (only one is shown in Fig. 3) serving as a light source for an indicator lamp is surface-mounted, and the circuit board 32 is housed in the main body case 30.

As shown in FIG. 1, the outer peripheral wall of the main body case 30 is provided with a plurality of ventilation holes 30d for allowing outside air to flow into the smoke detection chamber 36.
In the fire detector 10 of this embodiment, when smoke is generated by a fire or the like and flows into the smoke detection chamber 36 through the ventilation opening 30d, the light emitted from the light-emitting element 33 is scattered by the smoke that has flowed in, and the scattered light is received by the light-receiving element 34, thereby detecting the fire. In addition, the circuit board 32 is configured to light up the operation indicator lamp (light guide member 20, LED 35a) under predetermined conditions when a fire is detected based on the detection signal of the light-receiving element 34.

As shown in Figures 2(a) and 4, the light guide member 20 comprises an annular portion (light emission portion) 22 formed in a ring shape and rod-shaped light entrance portions 21, 21 extending downward from the annular portion 22, and both the annular portion 22 and the light entrance portions 21, 21 are made of a material that can transmit light.
A circular rib 40 is erected around the opening 30b of the main body case 30, and the outer circumferential surface of this rib 40 contacts the inner circumferential surface 22b of the annular portion 22 of the light guide member 20, and becomes a first reflection surface (light reflector) that reflects the light coming out from the inner circumferential surface 22b. Also, on the upper surface of the main body case 30, a ring-shaped flat surface is formed extending from the first reflection surface with a predetermined width in the radial direction, and this surface contacts the bottom surface 22d of the annular portion 22, and becomes a second reflection surface (light reflector) that reflects the light coming out from the bottom surface 22d. Furthermore, since a ring-shaped flat surface is formed on the peripheral portion on the back side of the lid portion 11, this surface contacts the upper surface 22c of the annular portion 22 described above, and becomes a third reflection surface that reflects the light coming out from the upper surface 22c.

Furthermore, as shown in Figures 2(b) and 3, the second reflecting surface forming portion that contacts the bottom surface 22d of the annular portion 22 of the main body case 30 has two fitting holes 30c formed therein to fit the two light incident portions 21 of the light guide member 20. Note that only one fitting hole 30c is shown in Figure 3.
4, the light from the LEDs 35a and 35b is incident on the lower end surfaces of the light incident portions 21 and 21. The lower end surfaces of the light incident portions are formed to be flat, convex, or concave as shown in FIG. 5(b), and the incident light travels toward the annular portion 22.

In this embodiment, of the LEDs 35a and 35b facing the light entrance portions 21 and 21, the LED 35a is of a type that emits visible light, and the LED 35b is of a type that emits invisible light. The on/off state of the invisible light side status indicator (LED 35b) can be confirmed using an infrared camera or an infrared sensor, for example, if the LED 35b emits light of an infrared wavelength. The method of controlling the lighting of the LEDs 35a and 35b will be described later. The invisible light side status indicator (LED 35b) is not limited to one that emits light of an infrared wavelength, and may be one that emits light of an ultraviolet wavelength. In addition, in a fire detector that does not have a history display function, the two LEDs 35a and 35b may be of a type that emits visible light, or the LED 35b may be omitted and only the LED 35a may be used. Furthermore, the blinking may be a fixed wavelength and a fixed duty ratio that does not have a transmission meaning.

4, the annular portion 22 of the light guide member 20 includes an emission surface 22a that emits light to the outside when the light guide member 20 is incorporated in a fire detector, i.e., serves as an indicator light, an inner peripheral surface 22b, a top surface 22c, and a bottom surface 22d. The emission surface 22a is formed as a slope between the top surface 22c and the bottom surface 22d.
In the annular portion 22, V-shaped notches 23, 23 are formed above the light incident portions 21, 21. Light from the light incident portions 21, 21 is reflected by the slopes of the notches 23, 23 and is sent to the annular portion 22.

In addition, the two surfaces forming each of the notches 23, 23 may be formed to have approximately the same predetermined angle with respect to a straight line parallel to the longitudinal direction of the light incident portions 21, 21, as shown in Figure 5 (b), or one surface 23a may be formed as a vertical surface and the other surface 23b may be formed as an inclined surface having a predetermined angle with respect to the vertical surface.
5C, a large number of fine grooves (microstructures) 24, 24, 24..., which are uniformly fine hairline grooves, are formed on the bottom surface 22d of the annular portion 22 of the light guide member 20. The light in the annular portion 22 is reflected in various directions by these fine grooves 24, 24....

The guide member 20 having the above-described structure is incorporated into the fire detector 10 by fitting the two light incident portions 21 into the corresponding fitting holes 30c of the main body case 30 and pressing them down with the lid portion 11, so that the guide member 20 is sandwiched between the lid portion 11 and the top surface of the main body case 30, as shown in Figure 3.
The ends of the two light incident portions 21 fitted into the two fitting holes 30c are respectively close to the two LEDs 35a (35b) on the circuit board 32, so that light emitted from each of the LEDs 35a (35b) is incident on the light incident portion 21. Specifically, as shown in Fig. 4, the LED 35a is disposed so as to face one end face of the two light incident portions 21, and the LED 35b is disposed so as to face the end face of the other light incident portion 21.

Furthermore, when the light guide member 20 is incorporated into the fire detector 10, the inner peripheral surface 22b of the annular portion 22 contacts the first reflective surface of the main body case 10, the bottom surface 22d contacts the second reflective surface, and the top surface 22c contacts the third reflective surface of the lid portion 11. Thus, light attempting to be emitted to the outside from the inner peripheral surface 22b, the bottom surface 22d, and the top surface 22c is reflected by the first reflective surface 40 and the second reflective surface 41 of the white main body case 10 and the third reflective surface 11d of the lid portion 11, respectively, and returns to the inside of the annular portion 22. This allows efficient light emission only from the emission surface 22a, resulting in a more easily visible indicator light.
The emission surface 22a of the annular portion 22 of the light guide member 20 is formed at an angle to the top surface 22c and the bottom surface 22d, so that, as shown in Fig. 3, when the light guide member 20 is set in the fire detector 10, the emission surface 22a forms an inclined surface that is formed at an angle to both the side and bottom surfaces of the detector 10. As a result, when the annular portion 22 emits light as an indicator light, it can be seen from various angles, eliminating any visual directionality.

Furthermore, since V-shaped notches 23, 23 are formed in the annular portion 22 of the light guide member 20, light from the light incident portions 21, 21 can be efficiently guided to the annular portion 22. Furthermore, since a large number of narrow grooves 24, 24... are formed in the bottom surface 22d of the annular portion 22, the light in the annular portion 22 is repeatedly reflected in a more complex manner and efficiently emitted from the emission surface 22a, resulting in an indicator lamp with sufficient brightness.
In the above embodiment, the light guide member 20 is made of a material that simply transmits light, but light scattering particles that scatter light may be mixed into the transparent material. The hairline grooves formed in the light guide member 20 are not limited to the bottom surface of the annular portion, and may be formed on the bottom surface, upper surface, inner peripheral surface, and emission surface as necessary.

Second Example
FIG. 6 shows the external appearance of a second embodiment of the fire detector 10, and FIG. 7 shows a specific example of an element support member 15 that functions as an indicator light constituting the fire detector 10 of FIG.
The fire detector 10 of this embodiment is a heat detector that uses a thermistor 18 as a heat-sensitive element and is capable of detecting a fire by detecting a change in electrical resistance that occurs when air heated by the heat generated by a fire comes into contact with the thermistor 18, and is configured to be installed and used on the ceiling surface of a building with the tip of the thermistor 18 facing downward. In the following explanation, the downward direction when installed on the ceiling surface of a building will be described as the upward direction.

As shown in Fig. 6, the heat detector 10 of this embodiment comprises a cylindrical main case 12 with a bottom that has a recess for accommodating heat-sensing components and can be inserted into an installation opening provided in the ceiling surface of a building, and a main case cover 13 that has a protector part 13A in the center that covers the tip of the thermistor 18 and is connected to the main case 12 so as to cover the upper opening of the main case 12, and the main case 12 and the main case cover 13 form a housing with an internal storage space. Although not shown, a terminal block is provided at the bottom of the main case 12 to electrically connect the wiring arranged on the underside of the ceiling to the internal circuit board.

The heat detector 10 also includes a circuit board 14 that is accommodated in the accommodation recess of the main body case 12 and fixed to a boss portion at the bottom of the main body case 12 by a screw (not shown), the thermistor 18 is mounted approximately in the center of the circuit board 14, and a cone-shaped element support member 15 is provided that has a cylindrical portion 15a through which the thermistor 18 can be inserted and is joined to the surface of the circuit board 14 with the base of the thermistor 18 inserted. The thermistor 18 is mounted on the circuit board 14, and resin 16 is filled and solidified in the lower cylindrical portion 15a of the element support member 15 through which the base of the thermistor 18 is inserted, thereby supporting the base of the thermistor 18.

The body cover 13 has a body portion which is generally in the shape of a flat disk, with an opening formed in the center of the body portion, and a protector portion 13A provided so as to cover the opening from above.
The circuit board 14 is composed of a printed wiring board on whose top and bottom surfaces electronic components such as resistors, capacitors, and ICs (semiconductor integrated circuits) that constitute an electronic circuit for fire detection are mounted, and approximately in the center of the circuit board 14, the tips of the two lead terminals of the thermistor 18 penetrate the circuit board 14 and protrude from the bottom surface and are connected to the circuit board 14 by soldering or the like.

7, the element support member 15 is provided with a cylindrical portion 15a for inserting the thermistor 18 therethrough, a tapered portion 15b extending obliquely upward from the cylindrical portion 15a, and a flange portion 15c extending horizontally outward from the lower end of the tapered portion 15b. Two cylindrical light entrance portions 15e are provided extending downward from the lower surface of the flange portion 15c.
In addition, the flange 15c of the element support member 15 is provided with a cylindrical light entrance portion 15e corresponding to the positions of the LEDs 35a, 35b mounted on the circuit board 14, and a light reflecting portion 15f is provided on the surface portion corresponding to the light entrance portion 15e. The end face of the light entrance portion 15e, i.e., the surface facing the LEDs 35a, 35b, is formed into a flat, convex, or concave shape suitable for the light emission characteristics of the LEDs 35a, 35b so that light from the LEDs 35a, 35b can be sufficiently introduced. The light reflecting portion 15f is omitted from the illustration in FIG. 7.

Two LEDs (light emitting diodes) 35a and 35b are surface-mounted on a predetermined portion of the circuit board 14 (a portion facing the end faces of the two light input portions 15e of the element support member 15). As in the first embodiment, one of the two LEDs 35a and 35b, LED 35a (or 35b), is an LED that emits red light (visible light), and the other LED 35b (or 35a) is an LED that emits infrared wavelength light (invisible light) that is invisible to the human eye. An LED that emits light of a wavelength equivalent to ultraviolet light instead of infrared wavelength light may be used. In a fire detector that does not have a history display function, the two LEDs 35a and 35b may be of a type that emits visible light, or LED 35b may be omitted and only LED 35a may be used.

Although not shown, the element support member 15 is provided with a plurality of (e.g., three) attachment locking pieces which stand downward from the outer circumferential surface of the tapered portion 15b and have outward claws at their tips, and engagement holes are formed in the corresponding portions of the circuit board 14 through which the claws of the locking pieces can be inserted, so that the element support member 15 can be attached to the circuit board 14 by the locking pieces.
Furthermore, a step (recess) 13b is provided on the underside of the opening edge of the disk-shaped main body part of the body cover 13, and the step 13b is configured to be joined to the underside of the flange 15c of the element support member 15. A film or layer with good light reflectance, such as aluminum, may be formed on the inner surface of the step 13b of the body cover 13 to which the flange 15c is joined.

The light reflecting portion 15f is a recess (groove) having an inclined surface perpendicular to the tapered portion 15b and a V-shaped cross section, and is formed so as to reflect the light guided from the light incident portion 15e in the inclined direction of the tapered portion 15b and in the circumferential direction of the flange portion 15c. As a result, when the LEDs 35a and 35b are turned on, the entire tapered portion 15b of the element support member 15 emits light and functions as a circular indicator lamp having a mortar shape.
In addition, the outer peripheral surface of the surface of the element support member 15 on the circuit board side (particularly the tapered portion 15b) may be microfabricated with a number of hairline-shaped fine grooves, so that the entire inner peripheral surface of the tapered portion 15b emits light more brightly as light hitting the grooves is reflected. In addition, microfabricating the element support member 15 has the effect of making it like frosted glass, making it impossible to see inside the sensor from the outside. In addition, fine particles that diffusely reflect light may be mixed into the material forming the element support member 15.

The protector part 13A formed integrally with the main body cover 13 includes a plurality of (e.g., six) straightening fins 13c that spread radially in a plan view, and a disk-shaped head cover 13d that connects the tips (upper ends in FIG. 6) of these straightening fins 13c. The tip of the thermistor 18 is located in the space surrounded by the plurality of straightening fins 13c and the head cover 13d, and airflow passes between each straightening fin 13c. The head cover 13d has a smaller diameter than the diameter of the base (lower part in the figure) of the protector part 13A, and is formed to form a trapezoid when the sensor is viewed from the side. Although the straightening fins 13c are arranged vertically in FIG. 6, they may be arranged horizontally (not shown).

In the heat detector of this embodiment having the above configuration, when the LEDs (light emitting diodes) 35a, 35b are turned on while the detector is installed on the ceiling surface of a building, the tapered portion 15b of the element support member 15 emits light, and the light is visible from any direction between the multiple rectifying fins 13c, i.e., 360°, eliminating the visual directionality. Therefore, there is no need to worry about the mounting angle when installing on the ceiling surface, and the installation work can be completed in a short time. Moreover, the light emitting area is larger than that of a detector equipped with a conventional point-emitting indicator light, and the light emitted from the tapered portion 15b also hits and is reflected by the surface of the rectifying fins 13c, increasing the apparent light emitting surface, improving visibility.

In addition, in the heat detector 10 of this embodiment, the element support member 15 also serves as an indicator light, making it possible to make the entire detector smaller in size compared to the smoke detection type fire detector of the first embodiment, in which a ring-shaped indicator light is formed from a separate member from the member (element support) that forms the storage space for the thermistor 18 and is attached to the main body cover.
Furthermore, the heat detector 10 of this embodiment is configured to have a mortar-shaped element support member 15 with a relatively large opening through which the thermistor 18 is inserted, thereby improving assembly workability, and since the gap between the inner wall of the cylindrical portion 15a of the element support member 15 and the base of the thermistor 18 is filled with resin, the thermistor 18 can be supported in a stably state and dust and moisture are less likely to enter the storage space of the circuit board, thereby preventing dust and moisture from adversely affecting the circuit board.

8 shows a functional block diagram of a detector circuit 50 formed on the circuit board 32 constituting the fire detector of the first embodiment. The detector circuit of the circuit board 14 constituting the fire detector of the second embodiment can also be configured to have the same configuration except for the fire detection section 52.
As shown in Fig. 8, the detector circuit 50 includes a power supply circuit 51, a fire detection section 52, a fire detection circuit 53, a control circuit 54, a fire signal generation circuit 55, a self-holding circuit 56, a fire history storage circuit 57, a storage time control circuit 58, indicator lamp drive circuits 59a and 59b that light up and blink LEDs (light emitting diodes) 35a and 35b to indicate operation, and a control signal detection circuit 60. The blinking caused by the indicator lamp drive circuits 59a and 59b may be a constant wavelength and a constant duty ratio that does not have a transmission meaning.

The power supply circuit 51 receives voltage from the district circuit line of the fire control receiver (not shown) and supplies power to each part. When the voltage of the district circuit line stops for a predetermined time due to a restoration pulse output by turning on a restoration switch provided in the fire control receiver, the power supply voltage supplied from the power supply circuit 51 to each part is reduced or stopped.
In the detector of the first embodiment, the fire detection unit 52 detects smoke using a light-emitting element 33 and a light-receiving element 34 arranged in a dark room into which the smoke flows, while in the detector of the second embodiment, the fire detection unit 52 detects heat using a thermistor 18.
The fire detection circuit 53 judges whether or not there is a fire based on the output of the fire detection section 52, and if it judges there is a fire, it notifies the control circuit 54 of the fire judgment.

The control circuit 54 has a memory for storing a control program and a CPU (Central Processing Unit) for executing the control program. The CPU executes the control program to comprehensively control the sensor circuit 50. The control circuit 54 may be hardware such as a sequencer.
The fire signal generating circuit 55 has the function of outputting a fire signal to the fire receiver 30 according to the control of the control circuit 54 when a fire is detected or the output of the self-holding circuit 56, and generates a fire signal, for example, by short-circuiting the district circuit line and causing a higher current than usual to flow.

The self-holding circuit 56 maintains the state when the fire detection circuit 53 determines that there is a fire and a fire signal is output from the fire signal generating circuit 55 so that the fire signal can continue to be output even if the fire determination is no longer made, and can be constituted, for example, by a latch circuit.
The fire history storage circuit 57 is a circuit that stores the processing operation in which the fire detection circuit 53 judges a fire and the control circuit 54 outputs a fire signal as a fire detection history, and is configured so that the stored data is not erased even if the power supply is temporarily stopped by the recovery pulse. The fire history storage circuit 57 can be configured with a non-volatile memory such as a flash memory or an EEPROM (Electrically Erasable Programmable Read-Only Memory). Since the fire history storage circuit 57 only needs to erase the stored data during the time width of the recovery pulse and the amount of data to be stored is small, a self-holding circuit that can hold the state for a certain period of time even if the power supply is stopped may be adopted.

The memory time control circuit 58 includes a timer, starts timing under the control of the control circuit 54, and outputs timing data to the control circuit 54. The memory time control circuit 58 may be configured so that the control circuit 54 sets a timing value, and when the set timing value is reached, the memory time control circuit 58 notifies the control circuit 54.
The control signal detection circuit 60 detects control signals (commands) input from the district circuit lines, and performs demodulation processing etc. on the signals input from the district circuit lines to decipher the commands. When a command is detected, it notifies the control circuit 14.

Next, the output of the fire detection signal by the detector circuit 50 and the drive control operation of the indicator light will be explained using the time charts in Figures 9 to 12. In Figures 9 to 12, the output of the fire signal is indicated as "alarm", and the state in which there is no fire signal output is indicated as "normal". Furthermore, "ON" and "OFF" in "timing" refer to the start and end of timing the specified time T1 for generating a history display restoration request. Furthermore, "fire display" refers to the display of an alarm in the fire receiver. Although not shown, the memory time control circuit 58 operates while the fire detection history is stored, from the start of the alarm (t1) until after the indicator lights (LEDs 35a, 35b) are turned off.

FIG. 9 shows a first control operation when the sensor circuit 50 detects the occurrence of a fire.
As shown in Figure 9, when the fire detector 10 activates an alarm (outputs a fire signal) at timing t1, the operation indicator light (LED 35a) on the visible light side of the fire detector 10 lights up (t2), and the fire receiver begins to display an alarm (t3).
When the monitor confirms that there is no fire and operates the recovery switch of the fire receiver at any timing t4, a recovery pulse is output from the fire receiver to each district circuit line. The recovery pulse stops the voltage of the district circuit line for a predetermined time, and the alarm (fire signal output) state held in the self-holding circuit 56 of the detector circuit 50 is released (t5), and the operation indicator light (LED 35a) is turned off (t6). On the other hand, even if a recovery pulse is input to the detector circuit 50, the fire detection history is stored in the fire history storage circuit 57.

During recovery control, a history display request is internally generated in the control circuit 54. Then, the non-visible light side status indicator light (LED 35b) starts to light or blink based on the history display request and the stored history (t7). In addition, in the storage time control circuit 58, a timer measures a predetermined period T1 (e.g., 3 to 7 days) from the time of recovery in order to generate a history display recovery request, and when the measurement is completed (t8), the status indicator light (LED 35b) for displaying history is turned off (t9).
Due to the operation of the detector circuit 50 as described above, a supervisor or maintenance manager can patrol the area where the fire detectors 10 are installed within a predetermined period T1 after the fire receiver alarm and check the operation state of the status indicator light (LED 35b), thereby identifying the fire detector 10 that detected the fire. Then, the cause of the fire detection can be investigated.

As described above, in a fire alarm system using the fire detectors of the above embodiments, if any of the fire detectors 10 makes an erroneous detection, even if a recovery operation is performed midway, the status indicator light will be lit, making it easy to identify the detector that made the detection due to a cause other than a fire and useful for investigating the cause of the detection due to a cause other than a fire.
In addition, according to a fire alarm system that performs the first control operation described above, it is possible to realize control of the status indicator light (LED 35b) based on the fire detection history by simply replacing or modifying the detector while keeping the existing fire receiver in use.

FIG. 10 shows a second control operation when the sensor circuit 50 detects the occurrence of a fire.
The second control operation is the control operation when the fire detector 10 emits a history display request and a history display restoration request, i.e., the control operation at timings t1 to t4, is almost the same as the first control operation in Figure 9, so duplicated explanations will be omitted.
In the second control operation, a history display request is issued inside the fire detector 10 by timing a first time length Ta from the restoration time (t5) of the detector 10. Also, a history display restoration request is issued inside the fire detector 10 by timing a second time length Tb from the issuance time (t7) of the history display request.

In the second control operation, in order to time the first time length Ta, a process is added in which the control circuit 54 sets the timer of the storage time control circuit 58 to time the first time length Ta when restoration control is performed. In order to time the second time length Tb, a process is added in which the control circuit 14 sets the timer of the storage time control circuit 58 to time the second time length Tb when a history display request is issued.
In the second control operation, as shown in the time chart of Fig. 10, when the monitor confirms that there is no fire and operates the recovery switch at any timing t4, a recovery pulse is output from the fire receiver to each district circuit line. This stops the fire detector 10 from issuing an alarm and the visible light side operation indicator light (LED 35a) from lighting up (t5, t6). On the other hand, even if a recovery pulse is input to the fire detector 10, the fire detection history is stored in the fire history storage circuit 57.

Furthermore, in the second control operation, when a recovery pulse is input, the timer of the memory time control circuit 58 starts timing the first time length Ta (t7). Then, when the first time length Ta has been timed (t8), the notification of the timer's timing becomes a request to display history, and if there is a history of fire detection, the status indicator light (LED 35b) on the non-visible light side starts to light or blink (t9). At the same time, the timer starts timing the second time length Tb, and when this timing is completed (t10), the status indicator light (LED 35b) for displaying history is turned off (t11).

By this operation, when a monitor or maintenance manager knows that a false alarm has occurred in the fire receiver, he or she can patrol the area where each fire detector 10 is installed within a specified period of time and check the status indicator lamp (LED 35b) on the non-visible light side to identify the fire detector 10 that has detected a fire due to a cause other than a fire. Then, the cause of the detection due to a cause other than a fire can be investigated.
According to the second control operation, in addition to the same action and effect as the first control operation, the effect of being able to arbitrarily set the display timing of the status indicator light (LED 35b) for displaying history based on the history of fire detection is obtained.

FIG. 11 shows a third control operation when the sensor circuit 50 detects the occurrence of a fire.
The third control operation is substantially the same as the first control operation, except that a history display restoration request is sent from the fire receiver to the fire detector 10 using the same pulse signal (restoration pulse Pe) as the restoration pulse Po.
In the third control operation, the control signal detection circuit 60 detects and counts the recovery pulses Po and Pe supplied from the fire control receiver via the district circuit line, and stores the count value so that it will not be erased even if the power is cut off by the recovery pulses Po and Pe. The count value can be stored in the non-volatile memory of the fire history storage circuit 57 so that it will not be erased even if the power is temporarily cut off.

The control circuit 54 also resets the count value of the recovery pulses Po and Pe by the control signal detection circuit 60 to, for example, "0" when a fire is detected and the fire detection history is stored in the fire history storage circuit 57, and when a predetermined period of time has passed and the history is erased. The control circuit 54 also reads the count value of the control signal detection circuit 60 immediately after the recovery pulses Po and Pe are input, and if it is the first time, recognizes this recovery pulse Po as a history display request. If it is the second time, recognizes this recovery pulse Pe as a history display recovery request.

In the third control operation, as shown in the time chart of FIG. 11, when the supervisor confirms that there is no fire and operates the recovery switch at any timing t4, a recovery pulse Po is output from the fire receiver to each district circuit line. The recovery pulse Po stops the output of voltage to the district circuit line that is the power source of the fire detector 10 for a predetermined time, and the fire detector 10 is restored and the alarm and the illumination of the visible light side operation indicator light (LED 35a) are stopped (t5, t6). On the other hand, even if the fire detector 10 is restored, the fire detection history is stored in the fire history storage circuit 57. Also, at the time of restoration, the count value "1" of the restoration pulses Po and Pe is stored in the control signal detection circuit 60, and the control circuit 54 recognizes this as a history display request. As a result, the control circuit 54 starts to light or flash the invisible light side status indicator light (LED 35b) (t7).
Furthermore, in the third control operation, after the monitor identifies the fire detector 10 that detected the fire, he or she operates the recovery switch again at any timing t8 to cause the fire receiver to output a recovery pulse Pe. Then, the second recovery pulse Pe is recognized as a history display recovery request by the fire detector 10 that detected the fire, and the history display status indicator light (LED 35b) is turned off (t9).

If the third or subsequent recovery pulses Po and Pe are input to the fire detector 10 before the history in the fire history storage circuit 57 is deleted, the control circuit 54 may be configured to regard the odd-numbered recovery pulses Po as a history display request and the even-numbered recovery pulses Pe as a history display recovery request. With this configuration, for example, by sending the third recovery pulse Po, the history display status indicator light (LED 35b) of the fire detector 10 that has detected a cause other than a fire can be turned on or blinked again, and by sending the fourth recovery pulse Pe, the history display status indicator light (LED 35b) can be turned off again.
As described above, according to the third control operation, the monitor can arbitrarily adjust the period during which the history display status indicator light (LED 35b) of the fire detector 10 that detected a fire is illuminated after recovery. Therefore, the monitor can control the history display status indicator light (LED 35b) to be lit or flashing only during the period during which the monitor goes on patrol.

FIG. 12 shows a fourth control operation when the sensor circuit 50 detects the occurrence of a fire.
The fourth control operation is similar to the third control operation except that a history display request and a history display restoration request are sent from the fire receiver to the fire detector by a pulse signal P1 having a longer pulse width than the restoration pulse P0.
In the fourth control operation, the control signal detection circuit 60 detects and counts a pulse signal P1 having a long pulse width, and stores the count value of the pulse signal P1 so that it is not erased even if the power supply is stopped by this pulse signal P1.

The control signal detection circuit 21 also has, for example, a capacitor that accumulates a predetermined amount of charge when power is input, a time constant circuit that discharges the charge of the capacitor with a predetermined time constant during the period when the power is stopped by the pulse signal P1, and a judgment circuit that judges whether the recovery pulse P0 or the pulse signal P1 is present based on the capacitor voltage after discharge. With this configuration, when the power is stopped by the recovery pulse P0 or the pulse signal P1 and then the power is turned on again, the judgment circuit can judge that the recovery pulse P0 is present if the capacitor voltage is within a predetermined range, and that the pulse signal P1 is present if the capacitor voltage is within a lower range.

On the other hand, the control circuit 54 resets the count value of the pulse signal P1 of the control signal detection circuit 60 to, for example, "0" when a fire is detected and the history is stored in the fire history storage circuit 57, and when a predetermined period of time has passed and the history is erased. After the recovery pulse P0 or pulse signal P1 is input, the control circuit 54 reads the count value of the control signal detection circuit 60. If the count value is zero, the control circuit 54 recognizes this as the input of a recovery pulse P0, and if the count value is "1", it recognizes this as the input of the first pulse signal P1, i.e., a request to restore history display. If the count value is "2", the control circuit 54 recognizes this as the input of the second pulse signal P1, i.e., a request to restore history display.

In addition, in the fourth control operation, in addition to the functions of the fire receiver in the first control operation, a function of outputting a pulse signal P1 with a longer pulse width than the recovery pulse P0 is added. For example, the recovery pulse P0 may be output to each district circuit line by a normal press of the recovery switch, and a pulse signal P1 with a longer pulse width may be output to each district circuit line by a long press of the recovery switch. Alternatively, the fire receiver may be configured to have a dedicated operation unit for outputting the pulse signal P1.

In the fourth control operation, as shown in the time chart of Fig. 12, when the monitor confirms that there is no fire and operates the recovery switch at any timing t4, a recovery pulse P0 is output from the fire receiver to each district circuit line. When the recovery pulse P0 is output, the fire detector 10 is restored due to a temporary power cut, and the alarm and the illumination of the visible light side operation indicator light (LED 35a) are stopped (t5, t6).
On the other hand, in the fourth control operation, after the recovery pulse P0 is input, the control circuit 54 reads the count value of the pulse signal from the control signal detection circuit 60. Since the count value of the pulse signal is "0" at the stages of timings t5 and t6, the control circuit 54 does not perform any special processing.
Thereafter, the monitor or maintenance person starts to investigate the cause of the false alarm. When starting the investigation, the monitor or maintenance person outputs the first long pulse signal P1 from the fire control panel (t7).

When the first long pulse signal P1 is output, the fire detector 10 is restored due to a temporary power outage, and the control circuit 54 reads the count value of the pulse signal from the control signal detection circuit 60. When the power supply voltage is input again after the output of the first long pulse signal P1, the count value of the pulse signal is "1", so the control circuit 54 recognizes this as a history display request. Furthermore, even if the fire detector 10 is restored, the fire detection history is stored in the fire history storage circuit 57. Based on this information, the control circuit 54 starts turning on or blinking the status indicator lamp (LED 35b) on the non-visible light side (t8).
This allows monitors to patrol the area where each fire detector 10 is installed and check the operating status of the non-visible light status indicator light (LED 35b), thereby identifying the detector that has mistakenly detected a fire and investigating the cause of the detection that is not a fire.

If the monitors are able to identify the detector that has detected a cause other than fire, they operate the fire receiver to output a second second long pulse signal P2 from each district circuit (t9). When the second long pulse signal P2 is output, the fire detector 10 is restored again due to a temporary power outage, and the control circuit 54 reads the count value of the second long pulse signal P2 from the control signal detection circuit 60. After the second output of the second long pulse signal P2, when the power supply voltage is input again, the count value of the pulse signal is "2", so the control circuit 54 recognizes this as a request to display the history. Based on this request, the control circuit 54 turns off the history display status indicator light (LED 35b) (t10).
As described above, according to the fourth control operation, the output of pulse signals P1, P2 from the fire receiver can cause the status indicator lamp (LED 35b) of each fire detector 10 to display a status based on the fire detection history information, or to stop this display, at any desired timing.

Next, an embodiment of a monitor device 70 for checking whether the operation indicator lamp (LED 35b) on the non-visible light side for displaying history is on or off will be described with reference to Fig. 13 and Fig. 14. Of these, Fig. 13(A) is an external perspective view of the monitor device 70 as seen from the front side, Fig. 13(B) is an external perspective view of the monitor device as seen from the rear side, and Fig. 14 is an exploded perspective view showing a specific example of the lens portion.
As shown in FIG. 13A, the monitor device 70 of this embodiment comprises a housing 71 that houses an image sensor such as a CCD or CMOS image sensor and a battery, a lens unit 72 provided on the front side of the housing 71 for converging light from a subject onto the internal image sensor, and a grip (handle portion) 73 provided so as to protrude downward from the bottom surface of the housing 71.

Here, as the imaging element built into the housing 71, if the non-visible light status indicator lamp for displaying history provided on the sensor to be checked uses an infrared LED as a light source, it is preferable to use an infrared imaging element capable of capturing light in the infrared wavelength band, and if the light source is an ultraviolet LED, it is preferable to use an ultraviolet imaging element capable of capturing light in the ultraviolet wavelength band.
As shown in FIG. 13B, the monitor device 70 of this embodiment is provided with an image monitor 74 consisting of a liquid crystal display panel or the like on the back surface of the housing 71, and an operation button 75 for switching the power on and off is provided on the side surface or the like of the housing 71.
14, the lens unit 72 includes a lens unit main body 72A and an image blurring filter 72B attached to a front end opening 72a of the lens unit main body 72A. The filter 72B may be made of a mesh, a plate-like glass such as frosted glass or uneven glass having an uneven surface, or a resin plate formed in a lattice shape from a transparent resin such as acrylic.

By providing the filter 72B, it is possible to prevent a person from being reflected in the image displayed on the image monitor 74, thereby preventing the person from violating privacy, and also to inform the person in front that the camera is not an ordinary camera by making the filter 72B visible, thereby giving the person in front a sense of security.
Furthermore, the monitor device 70 is equipped with an indicator light capable of emitting invisible light, and can be used when it is desired to check whether the history indicator light of a fire detector is on.

Although the present invention has been described above based on the embodiment, the present invention is not limited to the above embodiment. For example, in the above embodiment, the LEDs 35a and 35b are arranged facing the end faces of the two light entrance parts 21 (15e), but for example, the end of each light entrance part 21 (15e) may be cut into a mountain shape, and a pair of LEDs 35a and 35b may be arranged facing each cut surface. With this configuration, the amount of light incident on one light entrance part 21 (15e) is reduced, but since light from multiple light entrance parts 21 (15e) can be guided to the light emission part (22, 15b), the light emission part (22, 15b) can be made to shine more uniformly over its entire circumferential direction. The diameter of each light entrance portion 21 (15e) may be made larger, and the LEDs 35a and 35b may be mounted so that their optical axes are perpendicular to the cut surfaces. Also, the LEDs 35a and 35b are not limited to surface mounting types, and may be bullet-shaped.

In addition, in the above embodiment, the light guide member 20 (15) has two light entrance portions 21 (15e), but the light entrance portions 21 (15e) may be three or more.
Furthermore, in the above embodiment, the emission surface (indicator light) that emits light from the annular portion 22 (15b) to the outside is circular, but it does not have to be circular and may be elliptical or have a star-like or flower-like shape with multiple bends.
In addition, the emission surface of the light guide member is not limited to the above-mentioned ring shape, but may be a disk, a substantially polygonal plate, or the like. In short, it is sufficient if the shape allows the indicator light to be seen from any angle when the fire detector attached to the ceiling is viewed.
In addition, in the above embodiment, a history display has been used as an example of a cause for turning on the invisible light indicator light, but this is not limited to this. The invisible light indicator light may also be used, for example, to display a sensor fault or a self-diagnosis result.

10 Fire detector 11 Lid portion 20 Light guide member 21 Light incident portion 22 Annular portion (light emitting portion)
23 Notch (light guide part)
30 Main body case 30b Opening 31 Base 32 Circuit board 35a, 35b LED (light source)
12 Body case 13 Body cover 14 Circuit board 15 Element support member (light guide member)
15b Tapered portion (light emitting portion)
15e Light input section 50 Sensor circuit

Claims (5)

A fire detector including a circuit board on which a fire detection circuit for detecting a fire is formed, a plurality of light sources connected to the circuit board, a housing for accommodating the circuit board and the plurality of light sources, and an indicator light that lights up by light from the light sources to provide an indication;
A monitor device for checking whether the indicator lamp is on or off;
A fire alarm system comprising:
At least one of the plurality of light sources of the fire detector is a first light source that emits visible light, and at least one of the light sources other than the first light source that emits visible light is a second light source that emits invisible light ,
The first light source is for detecting and indicating a fire,
The second light source is for displaying at least history information of fire detection,
The fire detector includes a storage means for storing, as a history, the fact that the fire detection circuit has detected a fire, a drive means for driving the plurality of light sources to light up or blink, and a control circuit for controlling the drive means, and the control circuit controls the drive means to light up or blink the second light source when fire detection history information is stored in the storage means upon receiving a recovery pulse,
The fire alarm system according to the present invention is characterized in that the monitor device comprises a detection means for detecting the invisible light emitted from the second light source, and a display means for displaying a detection result. The fire detector includes a timer.
2. The fire alarm system according to claim 1 , wherein the control circuit, upon receiving a restoration pulse, causes the driving means to light or blink the second light source for a predetermined period of time measured by the timer. The fire detector includes a timer.
The fire alarm system according to claim 1, characterized in that the control circuit controls the driving means to turn on or blink the second light source only from the point when a first predetermined time measured by the timer has elapsed after receiving a recovery pulse until a second predetermined time measured by the timer has further elapsed. 4. The fire alarm system according to claim 1, wherein the light source that emits the invisible light is a light source that emits light with an infrared wavelength or an ultraviolet wavelength. The fire alarm system according to any one of claims 1 to 4, characterized in that the control circuit causes the driving means to turn on or blink the second light source that emits the invisible light based on a request to display a malfunction or self -diagnosis result of the fire detector .

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