JPH057760B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a photoelectric smoke detector.

[Background technology]

Conventional light beam type smoke detectors of this type have their sensing function significantly degraded due to dirt on the optical system and aging of the light emitting element and light receiving element, reducing safety when used as a fire detector. It was a contributing factor.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a smoke detector that can detect dirt in the optical system before it occurs and prevent deterioration of the sensing function. The second invention also provides a smoke detector that can compensate for changes in the light-receiving gain of the light-receiving element, prevent the effects of aging, and improve reliability. Further, in the third aspect of the present invention, the light receiving element is controlled by external control to provide the light receiving element with light equivalent to that at the time of smoke detection, thereby setting the light receiving element in a pseudo state similar to that at the time of smoke detection. It is an object of the present invention to provide a smoke detector that can determine the function of a smoke detector and further improve its reliability.

[Disclosure of the invention]

The present invention will be explained below with reference to Examples. FIG. 1 shows a basic schematic configuration diagram of a fire alarm system using one embodiment, in which a signal line L derived from a receiver 1 includes a smoke detector 2, a general type smoke detector 3a, and a heat sensor. 3b are connected together. The receiver 1 cyclically superimposes a transmission signal V _S consisting of a pulse code signal including an address signal individually assigned to each smoke detector 2 on the line voltage or current of the signal line l as shown in FIG. A general smoke detector It is possible to perform various control operations such as receiving the level signal V _L from the heat sensor 3a or the general type heat sensor 3b.

Each smoke detector 2 can have its own address set, and when the address signal included in the transmission signal V _S sent from the receiver 1 matches its own set address, it reads the control data in the transmission signal V _S. Various information is superimposed and sent back to the receiver 1 as a pulse code signal during a return period provided between the first transmission signal _VS and the next transmission signal _VS.
When the general type smoke detector 3a or heat sensor 3b detects a predetermined smoke concentration or temperature, it turns on and short-circuits the signal line l through an appropriate resistor to change the level of the line current or line voltage, etc. The fire detection signal is transmitted to the receiver 1 as a signal _VL .

Therefore, at normal times, the receiver 1 sequentially calls each smoke detector 2, receives information from each smoke detector 2, and makes judgments, and also detects the voltage or current level of the signal line l. , monitor the operation of the general smoke detector 3a or heat sensor 3b,
Furthermore, the stationary line voltage or line current caused by the terminator 4, such as the resistance of the signal line 1, is detected to monitor short circuits and disconnections of the signal line 1.

Next, the specific configurations of the receiver 1 and the smoke detector 2 will be explained.

As shown in FIG. 3, the receiver 1 is composed of a basic unit (|A) and an extension unit (|B), and the extension units (|B) can be combined as necessary.

The basic unit (|A) includes a coupling circuit section 5 for interfacing with the signal line l, and a coupling circuit section 5.
A level detection circuit section 6 that discriminates between the level signal V _L of the general type smoke detector 3a or the heat sensor 3b, short circuit, and disconnection voltage levels from the line voltage extracted by the line voltage, and a coupling circuit section. ₅ ; Level detection information discriminated by level detection circuit unit 6 and transmission signal modulation/demodulation circuit unit 7
The information demodulated from the smoke detector 2 is read in to determine the occurrence of a fire, or to identify the location of a fire, and also to determine the occurrence of a disconnection or short circuit in the signal line l. It also has the function of determining abnormalities in the equipment 2, and based on these determination results, fire area display, fire alarm, warning, area alarm, and detection corresponding to the signal line through the I/O interface 11. It generates control outputs such as abnormality display of equipment, signal line abnormality display, control of smoke prevention equipment and fire extinguishing equipment, etc., and sends and receives information to and from the expansion unit (|B) through interface 9. The transmission signal modulation/demodulation circuit section 7 generates a pulse code signal for calling the device 2.
an arithmetic signal processing circuit section 8 consisting of a CPU, etc., which performs control signal processing such as sending signals to the computer; and a storage section 1 that stores and holds settings for control operations of the arithmetic signal processing circuit section 8.
0, a keyboard 12, etc. On the other hand, the expansion unit (|B) is the basic unit (|A)
It is capable of transmitting and receiving data via an interface 1313' to the sensor, and is equipped with a combination table and relay means for connecting a specified sensor with external equipment such as a corresponding fire extinguisher or smoke prevention device. A storage section 14 stores combination data for setting the combination of the relay means and the number of the signal line l to which it belongs, data from the basic unit (|A), and the setting contents of the storage section 14. Selection control of smoke prevention equipment, etc. that should be used, display of the operating status of each sensor, display of the operating status of the relay means by displaying the number of the signal line l corresponding to the relay means, and furthermore, fire extinguishing equipment and smoke prevention equipment A series of controls such as control operations such as interlocking displays that display the operating status of the smoke exhaust equipment, etc., control of the smoke exhaust equipment, etc. by manual commands from the keyboard 15, and input of monitoring data of the operating status of the smoke exhaust equipment, etc. , an arithmetic signal processing circuit unit 16 that performs signal processing, and an I/O that interfaces the keyboard 15 and display unit 17 with the arithmetic signal processing circuit unit 16.
It is provided with an interface 18, and provides selection control data for smoke prevention devices, etc. to the basic unit (|A), and causes the basic unit (|A) to generate control outputs for the smoke prevention devices, etc. Of course, the smoke prevention device and the like may be controlled by the extension unit (|B). Note that 13' is an interface for expansion. In the figure, 17' is an external display section.

As shown in FIG. 4, the smoke detector 2 has a body composed of a base 2a and a head 2b, and has an internal circuit as shown in FIG. In other words, the head 2b includes a light beam type smoke detection section 19 for detecting smoke, a light reception gain adjustment circuit section 20 for adjusting the light reception gain of the smoke detection section 19, and a smoke detection section 1.
an output circuit section 21 that outputs an analog signal according to the detected smoke concentration of 9; and a first light emission control section 23 that controls light emission of the first light emitting element 22a of the smoke detection section 19.
a, and a second light emission control section 23b that controls light emission of the second light emitting element 22b. As shown in FIG. 6, in the smoke detection section 19, the light emitting element 22a is arranged so that the light emitting direction of the light emitting element 22a is opposite to the light receiving surface of the light receiving element 25, and the light emitting direction of the light emitting element 22b is opposite to the light receiving surface of the light receiving element 25. The light emitting element 22b is arranged in a direction perpendicular to the light receiving surface.

On the other hand, the base 2a removably mounts the head 2b, supplies power to the circuit inside the head 2b, and outputs the output from the output circuit section 21 and each light emission control section 23.
a, 23b and the light reception gain adjustment circuit section 20, and includes a signal conversion circuit section 24 that A/D converts the analog signal from the output circuit section 21 and outputs digital smoke density data; The output data from the signal conversion circuit section 24 is taken in and sent back to the receiver 1, and a return signal consisting of a pulse code signal based on this information is created, and the address set in the address setting section 29 is and the transmission signal transmitted from the receiver 1 via the signal line l.
When the address signal included in V _S matches, the control data from the receiver 1 included in the transmission signal V _S is taken in, and each light emission control section 23a, 23b and light reception gain adjustment circuit section 20 are controlled. At the same time, an arithmetic signal processing circuit section 26 that performs signal processing such as sending out the return signal during the return period following the transmission signal V _S is coupled to the signal circuit 1 to output the transmission signal.
It includes at least a coupling circuit section 27 for extracting V _S or superimposing a return signal on the signal line l, and a power supply section 28 for obtaining power through the coupling circuit section 27. Now, in the receiver 1, the following operating conditions can be set in the storage section 10 using the keyboard 12. First, in this system, fire occurrence determination is made based on a combination of the smoke density from the smoke detector 2 and a time function, in addition to the level signal V _L from the general smoke detector 3a and heat sensor 3b. On the receiver 1 side, the detected smoke concentration, which is a condition for determining the occurrence of a fire, and the duration of the detected smoke concentration can be selected and set for each smoke sensor 2 from the keyboard 12. In other words, smoke detector 2
The detected smoke concentration data returned from
There are several types, and one of these detected smoke concentrations can be combined with one of the times, and the sensitivity setting for fire occurrence can be made using two functions: smoke concentration and time. This setting condition is determined by the installation location of each smoke detector 2.

In the receiver 1, the transmission signal V _S is superimposed on the line voltage of the signal line l as shown in FIG. The state of each smoke sensor 2 is checked by calling up the smoke sensor 2 and sending out information on the detected smoke concentration from each smoke sensor 2.

Now, when the receiver 1 receives a return signal from the smoke detector 2 at the predetermined address, the arithmetic signal processing circuit section 8 detects the smoke sensor 2 stored in the storage section 10.
The detected smoke concentration for determining the occurrence of a fire is compared with the detected smoke concentration data in the return signal, and if the detected smoke concentration data is smaller than the set detected smoke concentration, the arithmetic signal processing circuit section 8 determines that no fire has occurred. It is to judge. Conversely, if the detected smoke concentration is higher than the detected smoke concentration, the set time is counted by the fire determination timer. The built-in timer continues counting as long as the above-mentioned cyclic calls are repeated and the returned detected smoke concentration data does not fall below the set detected smoke concentration. If it is determined that the set time has elapsed, it is determined that a fire has occurred, and the fire is reported by the bell 31 or the like.

By the way, when checking the smoke detecting section 19 of the smoke sensor 2 for dirt or deterioration over time in the above-mentioned normal warning state, the check can be performed by a command from the receiver 1. In other words, when a check command is given to each smoke detector 2 by the transmission signal _VL from the receiver 1, or when a self-check program is started, the program according to the flowchart shown in FIG. It will be executed by the processing circuit section 26.

In other words, after initializing, the light emission control section 23a
is driven to cause the light emitting element 22a to emit light at a predetermined level. This light is directly received by the light-receiving element 25, and this light-receiving signal is passed through the output circuit section 21 and the signal conversion circuit section 24 to the arithmetic signal processing circuit section 25.
6. The arithmetic signal processing circuit section 26 compares the accepted light reception level data with predetermined and stored allowable lower limit light reception level data in a normal state through a clean optical system section, and calculates the received light reception level data. If the level is low, light receiving element 2
It is assumed that there is dirt in the optical system on the 5 side, and the dirt detection data is sent back to the receiver 1 as a return signal.
If the received light level taken in this judgment is a normal value, then the mode moves to the check mode of the light emitting element 22b.
First, while turning off the light emitting element 22a,
The light emitting element 22b is caused to emit light at a normal light emission level under the control of the light emission control section 23b, and this light emission causes
The light receiving level of the light receiving element 25 is checked. In other words, if there is no smoke in the smoke detection section 19, a small amount of scattered light will be received by the light receiving element 25,
A light reception signal having a light reception level as noise is generated from the light receiving element 25, but the light reception signal having a light reception level as noise is generated from the light receiving element 25.
If there is dirt on the optical system of the light receiving element 25 and the light emitting element 22b, the light receiving level will be lowered. Therefore, the arithmetic signal processing circuit section 26 sets the above noise light receiving level in advance with no dirt on the optical system of the light receiving element 25 and the light emitting element 22b. This noise light reception level data is compared with the light reception level at the time of check, and if the light reception level at the time of check is low, it is determined that there is dirt in the optical system of the light emitting element 22b, and the dirt detection data is sent as a return signal to the receiver 1.
It will be sent back to. Receiver 1, which has received the dirt detection data, issues an alarm to notify that there is an abnormality in smoke detector 2. Of course, the smoke detector 2 may be provided with a light emitting display element or the like to display an alarm on the smoke detector 2 side.

Now, if the noise light reception level check is also normal, then the light reception gain is adjusted. First, the light emitting element 22a emits light at a predetermined level, this light is received by the light receiving element 25, and the arithmetic signal processing circuit unit 26 controls the light receiving gain adjustment circuit unit 20 so that the light receiving level becomes a predetermined level that provides maximum sensitivity, for example. The light reception gain is adjusted by controlling the
When this adjustment is completed, the routine shifts to a normal alert state processing routine in which the light emitting element 22b emits light and the level of light received by the light receiving element 25 is monitored.

Further, as shown in FIG. 8, a remote check can be performed in which the light receiving element 25 is checked by creating a pseudo smoke detection state. In this case, when a command is given from the receiver 1 to the contact smoke detector 2 using the transmission signal V _S as in the above check, in the sensor 2, the light receiving element is A control signal is given to control the light emission level of the light emitting element 22a so that the light reception level corresponds to a predetermined smoke density when the light emitting element 25 performs smoke detection. Therefore, the light receiving element 25 enters a pseudo smoke detection state. The received light level data at this time is sent back to the receiver 1 as smoke density data from the arithmetic signal processing circuit section 26, and the receiver 1 determines whether the smoke density data is less than or equal to the predetermined smoke density data. Light receiving element 25
It determines that there is an abnormality on the side and issues an alarm.
The above series of signal processing by the arithmetic signal processing circuit section 26 corresponds to the remote check means in the invention set forth in claim 3. Of course, the arithmetic signal processing circuit section 26 of the smoke detector 2 may determine the abnormality and issue an alarm.

Thus, the arithmetic signal processing circuit section 26 includes smoke concentration detection means for detecting the light reception level of the light receiving element, light receiving element checking means, and light emitting element checking means.
It overlaps a part of the light receiving gain control means, and is composed of, for example, a CPU.

〔Effect of the invention〕

The present invention includes first and second light emitting elements arranged so that the emitted light is perpendicular to each other, and a light receiving surface facing the first light emitting element to directly receive light from the light emitting element. smoke concentration detection means, which includes a light-receiving element that receives light from the second light-emitting element as smoke reflected and scattered light; and a light receiving device that causes the first light emitting element to emit light at the time of checking, compares the light receiving level of the light receiving element at the time of the light emission with a preset normal light receiving level, and generates a dirt detection signal if it is less than the normal light receiving level. element checking means, and when the light reception level at the time of the check is equal to or higher than the normal light reception level, the second light emitting element is made to emit light and a preset steady noise light reception level of the light reception element is compared with the light reception level of the light reception element. However, since it is equipped with a light emitting element check means that generates a dirt detection signal if the received light level is less than the noise light reception level, it is possible to detect dirt on the optical system of the light receiving element.
It is possible to detect dirt on the optical system of the second light emitting element, and since it can detect these dirt beforehand, there is no risk of false alarms due to deterioration of the sensing function, and reliability is improved. It has the effect of being able to achieve this goal. Further, in the second invention, if the check of the light emitting element check means is normal, the first light emitting element is made to emit light, the light receiving level of the light receiving element is detected, and the light receiving gain is adjusted so that the light receiving level becomes a predetermined value. Since the sensor is equipped with a light receiving gain control means, it is possible to compensate within an acceptable range for a decrease in the light receiving level due to dirt in the optical system or aging of the element, thereby preventing false alarms due to aging or dirt. This has the effect of further improving reliability.

Furthermore, in the third invention, means for controlling the light emission level of the first light emitting element to correspond to a predetermined smoke detection level by external control;
a remote for the light receiving element that receives light from the first light emitting element whose light emission level is controlled by the means, and checks the function of the light receiving element by determining whether the light receiving level of the light receiving element is at a predetermined smoke detection level; Since it is equipped with a check means, it is possible to determine whether the light receiving element is good by creating a pseudo smoke detection state and determining the light receiving condition of the light receiving element at that time. This has the effect of making it possible to check the functions, etc. of the system, thereby ensuring further reliability.

[Brief explanation of drawings]

Fig. 1 is a schematic overall configuration diagram of the present invention, Fig. 2 is a signal waveform diagram used in the above, Fig. 3 is a circuit block diagram of the receiver in the above, and Fig. 4 is the body of the smoke detector in the same. 5 is a circuit block diagram of the same smoke detector, FIG. 6 is a schematic diagram of the smoke detection section of the same smoke detector, and FIGS. 7 and 8 are explanations of the operation of the above smoke detector, respectively. Flow chart, 2 is smoke detector, 20
22a is a first light emitting element, 22b is a second light emitting element, 25 is a light receiving element,
23a and 23b are light emission control units, and 26 is an arithmetic signal processing circuit.

Claims (1)

[Claims] 1. First and second light emitting elements arranged so that the emitted light is orthogonal to each other, and a light receiving surface facing the first light emitting element to directly receive the light from the light emitting element. The smoke detection unit includes a light receiving element that receives light and receives light from the second light emitting element as reflected and scattered light of smoke, and the second light emitting element emits light during normal operation to detect the light reception level of the light receiving element. The smoke concentration detection means causes the first light emitting element to emit light at the time of the check, and compares the light reception level of the light receiving element at the time of the light emission with a preset normal light reception level, and if the light reception level is lower than the normal light reception level, a dirt detection signal is generated. a light-receiving element check means that generates noise, and when the light-receiving level at the time of the check is equal to or higher than the normal light-receiving level, a second light-emitting element is made to emit light, and a preset noise light-receiving level of the light-receiving element during normal operation and a light-receiving element of the light-receiving element are detected. 1. A smoke detector comprising: a light emitting element check means for comparing the light receiving level with the noise light receiving level and generating a dirt detection signal if the received light level is less than the noise light receiving level. 2. A first and a second light emitting element arranged so that the emitted light is orthogonal to each other, and a light receiving surface facing the first light emitting element to directly receive the light from the light emitting element, and a second light emitting element. smoke concentration detection means, which includes a light-receiving element that receives light from the light-emitting element as smoke reflected and scattered light in the smoke detection section, and detects the light reception level of the light-receiving element by causing the second light-emitting element to emit light during normal operation; A light-receiving element check that causes a first light-emitting element to emit light at the time of checking, compares the light reception level of the light-receiving element at the time of the light emission with a preset normal light reception level, and generates a dirt detection signal if the light reception level is lower than the normal light reception level. means, and when the light reception level at the time of the check is equal to or higher than the normal light reception level, the second light emitting element is made to emit light, and a preset noise reception level of the light reception element during normal operation is compared with a light reception level of the light reception element. If the received light level is less than the noise received light level, the light emitting element check means generates a dirt detection signal, and if the light emitting element check means checks normally, the first
1. A smoke detector comprising a light receiving gain control means for causing a light emitting element to emit light, detecting a light receiving level of a light receiving element, and adjusting a light receiving gain so that the light receiving level becomes a predetermined value. 3. A first and a second light emitting element arranged so that the emitted light is orthogonal to each other, and a light receiving surface facing the first light emitting element to directly receive light from the light emitting element, and a second light emitting element. smoke concentration detection means, which includes a light-receiving element that receives light from the light-emitting element as smoke reflected and scattered light in the smoke detection section, and detects the light reception level of the light-receiving element by causing the second light-emitting element to emit light during normal operation; A light-receiving element check that causes a first light-emitting element to emit light at the time of checking, compares the light reception level of the light-receiving element at the time of the light emission with a preset normal light reception level, and generates a dirt detection signal if the light reception level is lower than the normal light reception level. means, and when the light reception level at the time of the check is equal to or higher than the normal light reception level, the second light emitting element is made to emit light, and a preset noise reception level of the light reception element during normal operation is compared with a light reception level of the light reception element. If the received light level is less than the noise received light level, the light emitting element check means generates a dirt detection signal, and if the light emitting element check means checks normally, the first
a light receiving gain control means for causing the first light emitting element to emit light, detecting the light receiving level of the light receiving element, and adjusting the light receiving gain so that the light receiving level becomes a predetermined value; level,
means for controlling to correspond to a predetermined smoke detection level; and whether or not a light reception level of a light receiving element that receives light from a first light emitting element whose emission level is controlled by the means is at a predetermined smoke detection level. 1. A smoke detector comprising remote check means for a light receiving element for checking the function of the light receiving element by determining whether the light receiving element is functioning properly.