JPH0542037B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is such that a light emitting part and a light receiving part are arranged facing each other with a detection area interposed therebetween, and the light receiving part detects changes in light from the light emitting part due to smoke, etc. The present invention relates to a light beam detection device.

(Prior art) Conventionally, in the case of a light beam detection device, such as a separate type smoke detection device, in which a light emitting part and a light receiving part are placed facing each other with a predetermined detection area apart, the light emitting part and the light receiving part are separated by a detection area of, for example, 20 m. The light receiving section detects changes in the attenuation of light from the light emitting section due to smoke flowing into the detection area, and sends a fire detection signal to the receiver when the received light signal falls below a predetermined threshold level. I am trying to output it.

By the way, in such a separate type smoke detection device, when the light emitting part and the light receiving part are installed on a surface such as a ceiling, the detection area is Adjustments are made to bring the received light signal level to a predetermined level in a state where no smoke is flowing in.

However, in conventional devices, the light receiving section and the light emitting section are activated by power supply from the receiver to perform adjustment work. For example, during adjustment work, the front side of the light receiving element provided in the light receiving section is If it is accidentally shielded, a fire detection signal will be sent to the receiver even during adjustment when the received light signal falls below the threshold level. in this case,
Multiple other detection devices are connected to the same line from the receiver, and the fire signal is sent by short-circuiting the signal line from the receiver to a low impedance. When a fire is detected, the fire detection signal output during adjustment makes it impossible to receive the fire detection signal from the normal detection device, and in order to prevent the receiver from malfunctioning due to the fire detection signal generated during adjustment. The problem was that normal monitoring functions could not be obtained during the adjustment process.

(Object of the Invention) The present invention has been made in view of the above-mentioned problems, and allows inspection and adjustment to be performed without interfering with the fire monitoring operation of other detection devices such as light beam detection devices connected to the same line. It is an object of the present invention to provide a light beam detection device that can be easily switched to a monitoring state after adjustment.

(Structure of the Invention) To achieve this object, the present invention makes a light emitting part and a light receiving part face each other in a predetermined detection area, and detects a change in the detection area of light from the light emitting part by the light receiving part to generate a fire detection signal. In a light beam detection device outputting to a receiver, a selection means is provided in the light receiving section for selecting and setting detection sensitivity in the optical axis adjustment state and monitoring state of the light emitting section and the light receiving section, and monitoring whether the adjustment state is done based on selection information of this selection means. When it determines that it is in the adjusted state, it prohibits sending the fire detection signal to the receiver, and updates and registers the received light output as a reference value every time the received light output is obtained, and in the monitoring state. When it is determined that there is a fire, a threshold value is calculated by multiplying the detection sensitivity selected and set by the selection means by the updated and registered final reference value, and a fire judgment is made by comparing the threshold value and the detected amount of received light. A control means for instructing the receiver to send out a fire detection signal when a fire is determined is provided.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention. First, to explain the configuration, 1 is a receiver, and from the receiver 1, a fire signal line L1 that also serves as a power source and a common line L3 are drawn out, and each of a plurality of light receiving sections 2 and a plurality of fire detectors 5 are connected. It supplies power to the light receiving section 2 and the fire detector 5 that form a light beam type detection device to be described later, and when the light beam type detection device or the fire detector 5 detects a fire, a fire signal line L1 that also serves as a power source is supplied. and the common line L3 to send out a fire signal. Also, receiver 1
An inspection signal line L2 is drawn out from and connected to a plurality of light receiving sections 2. Here, the light receiving section 2 and the light emitting section 3 form a light beam detection device, and the light receiving section 2 and the light emitting section 3 are installed facing each other with a detection area 4 of a predetermined distance, for example, 15 m. A pair of signal lines L4 and L5 are drawn out from the light receiving section 2 and connected to the light emitting section 3.
It is controlled from the light receiving section 2 via 5. 3a is a light emitting element, which emits light in response to a command from the light receiving section 2, and makes the emitted light enter the light receiving element 2a. The light receiving unit 2 is provided with a prohibition means for prohibiting the sending of a fire signal during inspection and adjustment. When the inspection and adjustment are completed, the prohibition means is released and a reference value is set and registered based on the initial amount of received light, and this reference value is set and registered. A threshold value is calculated based on the value, and each time the emitted light from the light emitting unit 3 is received, a change in the amount of received light is compared with the threshold value to determine a fire. When the change in the amount of light received increases due to smoke entering the detection area, it is determined that there is a fire and a fire signal is sent out. The light receiving unit 2 also determines whether the registered reference value is normal or not, and if the reference value is abnormal, it sends out a check signal via the check signal line L2.

FIG. 2 is a block diagram showing the circuit configuration of the light receiving section 2 in FIG. 1. 6 is a constant voltage power supply, which receives the power supply from the receiver 1 and outputs, for example, 15V.
Outputs the power supply voltage Vh. Reference numeral 7 denotes a light emission control section, which controls the light emission operation of the light emission section 3 based on commands from the control section 8 . A constant voltage power supply 9 receives the power supply Vh from the constant voltage power supply 6, adjusts it to a voltage Vl lower than the power supply voltage Vh, for example, 5V, and continuously supplies it to the control unit 8. It maintains the memory operation of the built-in memory circuit. Reference numeral 10 denotes a clock circuit that generates clock pulses of a predetermined pulse width at a predetermined cycle, and when the first clock pulse from the clock circuit 10 is input, the control section 8 starts a series of control operations based on preset program control. do. A constant voltage power supply 11 receives power from the constant voltage power supply 6, adjusts it to a constant voltage Vm of, for example, 10V, and supplies power to the light receiving circuit 13 based on a control signal from the reception control section 12. The light receiving circuit 13 includes a light receiving element 2a, an amplifier circuit, and a hold circuit, and the light receiving element 2a is connected to the light emitting section 3.
The output of the received light is amplified by an amplifier circuit and held by a hold circuit. This held detection signal is sent to the A/D conversion circuit 16 based on a control signal from the control section 8.
15 is a power supply voltage monitoring circuit;
In addition to monitoring the drop in power supply voltage Vh by inputting the output voltage of is sent to the control section 8 via the A/D conversion circuit 16. Reference numeral 17 denotes a reference voltage generation circuit, which receives power supply from the reception control unit 12 and adjusts it to a predetermined voltage Vr, for example, 2.5V.
A reference voltage Vr is applied to the A/D conversion circuit 16. 1
Reference numeral 8 denotes a selection circuit for selecting and setting the adjustment state of the light beam detection device and the detection sensitivity during monitoring, which inputs the reference voltage Vr from the reference voltage generation circuit 17 via the resistor _R0 , and connects it to the resistor _R0 . Resistors R1, R2,...Rn with different resistance values are connected to the wire by switching using a rotary switch 18a, and the reference voltage Vr is connected to the resistors R1, R2,...Rn determined by switching the rotary switch 18a. Partial pressure at R ₀ ,
The divided voltage is sent to the A/D conversion circuit 16 to designate detection sensitivity during monitoring. Further, a shorting line is connected to the adjustment position on the right side of the rotary switch 18a, and the adjustment state is selected and set by drawing the connection line connected to the resistor R ₀ to the ground.
When the A/D conversion circuit 16 receives the detection information from the light receiving circuit 13 and the selection information from the selection circuit 18, it generates a digital code of multiple bits, for example, 4 bits, based on the reference voltage Vr from the reference voltage generation circuit 17. The A/D converted information is sent to the control unit 8. The control unit 8 inputs the selection information from the selection circuit 18 and determines whether it is in the adjustment state or the monitoring state, and when it determines that it is in the adjustment state, it prohibits the fire signal output unit 21 from sending out a fire signal, A monitor signal is output to the monitor signal output section 19. In addition, in the adjustment state, the light receiving circuit 13
The reference value is updated and registered every time the received light output is obtained, and when it is determined by switching the selection circuit 18 that it is in the monitoring state, the last reference value updated and registered is within the predetermined value range. If the value is outside the predetermined range, the inspection signal output unit 20 is instructed to send an inspection signal. During monitoring, a threshold value is calculated by multiplying the detection sensitivity selected and set by the selection circuit 18 by the registered reference value, and a fire judgment is made by comparing the threshold value and the magnitude of the detected amount of light received. When a fire is determined, the fire signal output section 21 is activated to issue a command to send out a fire signal.

FIG. 3 is a program flow diagram showing the control operation of the control section 8 shown in FIG.

To explain the operation with reference to the program flow diagram in FIG. 3, first, when installing the light beam detection device, it is necessary to adjust the optical axis of the light receiving section 2 and the light emitting section 3, and adjust the light receiving level, etc. block a
Then, the selection information from the selection circuit 18 is inputted to determine whether it is in the monitoring state or the adjustment state, and when it is determined in block b that it is in the adjustment state, the process advances to block c, where the fire judgment is stopped and a signal is sent to the fire signal sending section 21. Prohibit the sending of fire signals. In block d, light receiving circuit 1
Each time the received light output from 3 is obtained, it is updated and registered as a reference value, and at the same time, in block e, the monitor signal output section 19 is activated to output a monitor signal. Therefore, the adjustment worker can adjust the optical axis of the light emitting section 3 and the light receiving section 2 and the level of the light reception signal while checking the monitor signal without worrying about sending out a fire signal due to the adjustment. . Upon completion of the adjustment work, operate the rotary switch 18a built in the selection circuit 18 to set the desired detection sensitivity.
For example, when the detection sensitivity is switched to 50%, the selection information from the selection circuit 18 is decoded to determine that the monitoring state is at 50% detection sensitivity, and the process proceeds to block f. The power supply voltage monitoring circuit 15 monitors the power supply voltage, and when it is determined that the power supply voltage is normal based on the monitoring information from the power supply voltage monitoring circuit 15,
Proceed from block f to block g. In block g, a threshold value is calculated by multiplying the reference value registered in block d by the detection sensitivity value of 50%. In block h, a fire judgment is made by comparing the calculated threshold value and the detection signal from the light receiving circuit 13. If the amount of light reduction is small, that is, if the detection signal is larger than the threshold value, it is determined to be normal and the block is restarted. Return to step a and continue the monitoring operation. When the amount of light attenuation increases due to the intrusion of smoke, etc. into the detection area and the detection signal becomes smaller than the threshold, it is determined that there is a fire and block i is detected.
Then, the fire signal output unit 21 is activated to issue a command to send out a fire signal.

FIG. 4 is a circuit diagram showing another embodiment of the present invention. In this embodiment, when the rotary switch 18a built in the selection circuit 18 shown in FIG. It is characterized by stopping the operation and prohibiting the sending of fire signals, and when monitoring a fire, the rotary switch 18a
Switch to any detection sensitivity and set the thyristor.
When the SCR detection operation is started and the control unit 8 determines that there is a fire, a command signal of a predetermined voltage is given to the charging circuit consisting of the capacitor C and the resistor Rg via the resistor Rs.
The thyristor SCR is activated to light up the alarm indicator LED, and the line current determined by the resistor Rf is sent back to the receiver 1 to send out a fire signal.

In the above embodiment, the light emitting part that emits the emitted light and the light receiving part that receives the emitted light from the light emitting part are arranged to face each other with a predetermined detection area in between, and the light reception output due to smoke that has entered the detection area is determined. We have described a light beam detection device that sends a fire signal based on a change in the fire signal, but the detection signal is generated based on a change in the received light output when the emitted light from the light emitting part is blocked by a human body or object to be detected in the detection area. It can also be applied to burglar alarms, photoelectric switches, etc. that output .

(Effects of the Invention) As explained above, according to the present invention, the light emitting part and the light receiving part are made to face each other with a predetermined detection area in between,
In a light beam detection device that detects changes in the detection area of light from a light emitting part with a light receiving part and outputs a fire detection signal to the receiver, the light receiving part has information on the optical axis adjustment state and monitoring state of the light emitting part and the light receiving part. A selection means for selecting and setting the detection sensitivity, and determining whether it is an adjustment state or a monitoring state from the selection information of this selection means, and when it is determined that it is in an adjustment state, prohibiting the transmission of the fire detection signal to the receiver, and Each time a received light output is obtained, this received light output is updated and registered as a reference value, and when it is determined that the monitoring state is in progress, the detection sensitivity selected and set by the selection means is multiplied by the updated and registered final reference value. By providing a control means that calculates a threshold value, compares the threshold value with the detected amount of received light to determine a fire, and instructs the receiver to send out a fire detection signal when a fire is determined. When inspecting or adjusting the optical beam detection device, even if a fire detection state occurs due to the optical axis adjustment of the light receiving part and the light emitting part, it is prohibited to send a fire detection signal to the receiver, and if it is connected to the same line. Inspections and adjustments can be made without interfering with other fire monitoring operations.

Further, after this inspection and adjustment, the threshold value is automatically calculated and the monitoring state can be set by simply selecting and setting the detection sensitivity using the selection means.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
FIG. 2 is a block diagram showing the circuit configuration of the light receiving section in FIG. 1, FIG. 3 is a program flow diagram showing the control operation of the control section in FIG. 2, and FIG. 4 shows another embodiment of the present invention. It is a circuit diagram. 1: receiver, 2: light receiving section, 2a: light receiving element,
3: light emitting part, 3a: light emitting element, 4: detection area,
5: Fire detector, 6, 9, 11: Constant voltage power supply.

Claims (1)

[Claims of Claims] 1. A light beam in which a light emitting part and a light receiving part face each other with a predetermined detection area in between, and the light receiving part detects a change in the detection area of light from the light emitting part and outputs a fire detection signal to the receiver. In the type detection device, the light receiving section includes a selection means for selecting and setting the detection sensitivity of the light emitting section and the light receiving section in an optical axis adjustment state and a monitoring state by a switching operation, and a selection means for selecting and setting detection sensitivities in the optical axis adjustment state and monitoring state of the light emitting section and the light receiving section, and determining whether the adjustment state or the monitoring state is selected from the selection information of the selection means. and when it is determined that it is in the adjusted state, it prohibits the sending of the fire detection signal to the receiver, and updates and registers the received light output as a reference value every time the received light output is obtained, and is in the monitoring state. When it is determined, a threshold value is calculated by multiplying the detection sensitivity selected and set by the selection means by the updated and registered final reference value, and a fire judgment is made by comparing the threshold value and the detected amount of received light. 1. A light beam detection device comprising: control means for instructing a receiver to send out a fire detection signal when a fire is determined.