JP2000251170A - Photoelectric separaton type sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the optical axis more accurately and securely by allowing a photodetection part to detect the quantity of light from a light transmission part to output a photodetection signal indicating the photodetection quantity to a synchronous line and allowing the light transmission part to receive the photodetection signal from the synchronous line to output the photodetection quantity. SOLUTION: A photodetection part control circuit 3 once judging a fire from the quantity of light received by a photodetecting element 12 in synchronism with synchronizing pulses and inputted through a photodetecting amplifier circuit 14 and a sample holding circuit 15 turns on a fire signal output switching element 4 to turn on a fire pilot lamp 5 and also inform of the fire a receiver connected to terminals T1 and T2 through fire signal lines. When the synchronizing pulses are sent from the photodetection part side, a voltage detection circuit detects them and a light transmission part control circuit tuns on the electrified pilot lamp switching element with a prescribed pattern and supplies the electric power to the electrified pilot lamp, which blinks, so that the light transmission part side emits light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoelectric separation type sensor in which a light transmitting unit and a light receiving unit are separately arranged and a fire is detected by detecting light attenuation caused by smoke between the light transmitting unit and the light receiving unit.

[0002]

2. Description of the Related Art Conventionally, in a conventional photoelectric separation type sensor which requires adjustment of an optical axis and adjustment of a received light amount at the time of installation, a collimation provided on a sensor optical table after the sensor is mounted. Look into the hole, point the optical bench so that the opposing housing is inside the collimation hole on both the light transmitting side and the light receiving side, and then adjust the amount of received light on the light receiving side by turning the volume of the light receiving main body It is done in.

When the optical axis adjustment and the light receiving adjustment are performed, even when the fire is monitored after the adjustment is completed, it is necessary to supply power to the sensor from the receiver side and make the light transmitting unit emit light. However, when power is supplied from the receiver, the sensor makes a fire judgment based on the amount of light received, and if it judges that there is a fire, it transmits a fire signal to the receiver, and the receiver makes a fire judgment. Will be lost. In particular, in the P-type fire alarm system, the fire signal short-circuits the power supplied to the detector at the sensor side, and the receiver detects the increase in current and issues a fire signal. The power supply is shut off while the fire signal is being transmitted, so that the function is stopped.

Therefore, when adjusting the optical axis and adjusting the amount of received light, only a routine of light emission of the light transmitting section → receiving light → display of the amount of received light is executed so as not to send out a fire signal even if the amount of received light greatly fluctuates. It is necessary to switch the adjustment mode in which the display is not performed to the monitoring mode in which the fire monitoring is actually performed. Therefore, a switch for switching the mode is usually provided only on the sensor / light receiving unit side, and not provided on the light transmitting unit side.

[0005] In addition, when adjusting the optical axis and adjusting the amount of received light, it is necessary to supply power to the sensor from the receiver side to emit light from the light transmitting section even when monitoring a fire after the adjustment is completed. For example, when the power cannot be supplied from the receiver, the optical axis of the sensor may need to be adjusted and the amount of received light may need to be adjusted. Therefore, in preparation for such a case, the light receiving unit is provided with a standby power supply terminal so that the optical axis adjustment and the light receiving amount adjustment can be performed without a receiver.

[0006] In general, the photoelectric separation type sensor has two modes of monitoring / adjustment as described above. The monitoring mode is a normal mode for detecting a fire. The adjustment mode is a mode used when adjusting the optical axis. When adjusting the optical axis and the amount of received light, a fire signal or a failure signal is not sent to the receiver by accidentally blocking the front of the light receiving unit by hand. .

[0007]

By the way, in the case of such a conventional photoelectric separation type sensor, the optical axis adjustment can be performed to some extent on the light receiving section side, but the directional characteristic is not easily adjusted on the light transmitting section side. It needs to be done carefully because it is sharp. 1 optical axis adjustment
If it must be done by a human operator, first set the adjustment mode on the light receiving unit side, then adjust the optical axis of the light receiving unit side, and then move to the light transmitting unit side up to 100 m away,
It is necessary to adjust the optical axis on the light transmitting unit side.

After the optical axis adjustment on the light transmitting unit side is completed, the mode must be returned to the monitoring mode. However, since the switch is only on the light receiving unit side, the worker moves again to the light receiving unit side up to 100 m away. Then, it is necessary to switch the switch. In addition, the photoelectric separation type sensor is often mounted at a high place, and the movement between light transmission and light reception is often not easy. In addition, a method of separately laying a monitoring / adjustment switching wire besides the synchronization line between light reception and light transmission is also conceivable. However, since it is used only at the time of adjustment and the wire laying cost is high, it is a very preferable method. Not really.

Further, since the auxiliary power supply terminal may be connected in parallel to the fire signal line which is also a power supply terminal with some protection components interposed therebetween, the auxiliary power supply terminal can be relatively easily installed on the light receiving section side. The light transmitting unit, which is configured to be supplied with power from the light receiving unit via the synchronization line, must receive a synchronization pulse, which is a light emission command from the light receiving unit, from the synchronization line,
It does not operate simply by applying a standby power supply (a constant DC voltage). Therefore, the standby power supply terminal is usually provided only on the light receiving unit side, and cannot be provided on the light transmitting unit side.

In addition, the directional characteristics of the light transmitting unit are more sharp than those of the light receiving unit, and there is a need for fine adjustment of the optical axis. Normally, the light receiving unit side can complete the adjustment only with the collimation hole when adjusting the optical axis, but the light transmission unit side often does not match the field of view of the collimation hole and the directional characteristics of the light emitting element. It is necessary to adjust the optical axis while measuring the amount of received light. At this time, in the conventional photoelectric separation type sensor in which the standby power supply terminal is located only on the light receiving unit side, when performing the operation by one worker, the standby power supply is attached to the light receiving unit side, and the optical axis is adjusted by the collimation hole of the light receiving unit. Move to the light unit side → Adjust the optical axis of the light sending unit side while checking the received light amount, move to the light receiving unit side again → remove the standby power supply, and after completing the light sending unit work, remove the standby power supply and receive light. It is necessary to move to the department side. Usually, the monitoring distance of the photoelectric separation type sensor is 100 m at the maximum and the scaffold is often in an unstable place, so that there is a problem that the movement between transmission and reception often takes time.

The adjustment mode of the photoelectric separation type sensor is a mode which is normally used only when the optical axis of the sensor is adjusted, and is switched to the monitoring mode after the optical axis adjustment. If the user forgets to switch to the monitoring mode later, there is a problem that the photoelectric separation type sensor does not detect a fire and may cause a false alarm.

The present invention has been made to solve such a conventional problem, and does not separately lay wires, but uses only a two-core wire (synchronous wire) between light transmission and light reception. , Monitoring and adjustment can be switched from both the light receiving unit and the light transmitting unit, and a standby power supply can be connected to both the light receiving unit and the light transmitting unit, making it easy for one worker to make adjustments. The aim is to obtain a type sensor.

Another object of the present invention is to provide a photoelectric separation type sensor which can automatically switch from the adjustment mode to the monitoring mode when the execution time of the adjustment mode exceeds a certain time, thereby preventing an unmonitored state. I do.

[0014]

According to another aspect of the present invention, there is provided a photoelectric separation type sensor having a light transmitting unit and a light receiving unit provided opposite to the light transmitting unit with a smoke detection space interposed therebetween. A synchronization line for synchronizing light emission of the light transmitting unit and light reception of the light receiving unit is connected, and fire information is generated based on the fact that the amount of light received by the light receiving unit with respect to light emission of the light transmitting unit changes due to the presence of smoke. In the photoelectric separation type sensor for outputting the light, the light receiving unit detects a light receiving amount of the light from the light transmitting unit and outputs a light receiving signal indicating the light receiving amount to the synchronization line; The unit receives the light reception signal from the synchronization line and outputs a light reception amount.

The light receiving signal is a coded pulse signal, the light receiving amount output at the light transmitting unit is a voltage output to an output terminal, and the light receiving amount output at the light transmitting unit is a level or a number. This is a display on the display unit.

The light receiving section outputs a synchronization signal to a synchronization line at a predetermined cycle, and the light transmission section receives the synchronization signal from the synchronization line and emits light. The signal is output at a timing based on the synchronization signal.

Further, a photoelectric separation type sensor according to the present invention has a light transmitting unit and a light receiving unit provided opposite to the light transmitting unit with a smoke detection space interposed therebetween. A synchronization line for synchronizing light emission and light reception of the light receiving unit is connected,
In a photoelectric separation type sensor that outputs fire information based on a change in the amount of light received by the light receiving unit with respect to light emission of the light transmitting unit due to the presence of smoke, the light receiving unit is in a state of a monitoring mode and an adjustment mode. And the light transmitting unit has a mode changeover switch for switching between a monitoring mode and an adjustment mode, and the light transmitting unit detects an operation of the mode changeover switch. Outputting a mode switching signal to the synchronization line, and receiving the mode switching signal from the synchronization line to switch the monitoring mode or the adjustment mode of the mode setting means to the other mode. .

Further, the mode switching signal is a pulse signal, and the light receiving section has a mode selection switch for selecting a state between the monitoring mode and the adjustment mode, and sets the state to the mode setting means based on the switch. Things.

Further, the light receiving section has an indicator light for indicating that the mode setting means is in the adjustment mode,
Further, the light receiving section outputs a synchronization signal to the synchronization line at a predetermined cycle, and the light transmission section outputs a mode switching signal at a predetermined timing based on the synchronization signal.

Further, the photoelectric separation type sensor according to the present invention has a light transmitting section and a light receiving section provided opposite to the light transmitting section with a smoke detection space interposed therebetween. A synchronization line for synchronizing light emission and light reception of the light receiving unit is connected,
In a photoelectric separation type sensor that outputs fire information based on a change in the amount of light received by the light receiving unit with respect to light emission of the light transmitting unit due to the presence of smoke, the light receiving unit includes a power line and a signal from a receiving unit. A line is connected, and power is supplied to the light transmitting unit via the synchronization line, and the light transmission unit has a standby power supply terminal connected to the synchronization line, and the light receiving unit is connected to the synchronization line. And a path connected to the power supply line for supplying the power.

Further, a backflow preventing means is provided on the path.

The light receiving section includes a power supply terminal, a constant voltage circuit for adjusting the power from the power supply terminal to a predetermined voltage and outputting the adjusted voltage, and an output of the constant voltage circuit via a first backflow prevention element. An output terminal for outputting to a synchronous line, wherein a path is provided between the first backflow prevention element and the output terminal via a second backflow prevention element, the power supply terminal and the constant voltage circuit, It leads to between.

Further, the photoelectric separation type sensor according to the present invention has a light transmitting section and a light receiving section provided opposite to the light transmitting section with a smoke detection space interposed therebetween. A synchronization line for synchronizing light emission and light reception of the light receiving unit is connected,
A mode setting for setting a monitoring mode and an adjustment mode in a photoelectric separation type sensor that outputs fire information based on a change in the amount of light received by the light receiving unit with respect to light emission of the light transmitting unit due to the presence of smoke. Means, and timer means for starting when the adjustment mode is set and resetting when returning to the monitoring mode and performing timer output when a predetermined time has elapsed, and providing timer output from the timer means. The mode setting means is switched to the monitoring mode based on the information.

Further, the light receiving section has mode setting means, and the light transmitting section has a mode changeover switch for outputting a mode changeover signal via a synchronous line. Upon receiving the mode switching signal, the mode setting means switches the monitoring mode or the adjustment mode to the other mode.

Further, the light receiving section has a mode selection switch for selecting a state between the monitoring mode and the adjustment mode, and sets the state in the mode setting means based on the switch. It is a pulse signal.

Further, the photoelectric separation type sensor according to the present invention has a light transmitting section, and a light receiving section provided opposite to the light transmitting section with a smoke detection space interposed therebetween. A synchronization line for synchronizing light emission and light reception of the light receiving unit is connected,
In a photoelectric separation type sensor that outputs fire information based on a change in the amount of light received by the light receiving unit with respect to light emission of the light transmitting unit due to the presence of smoke, the light transmitting unit has a microprocessor, A microprocessor detects a synchronization signal from the light receiving unit via the synchronization line and performs light emission control of the light transmission unit, and the microprocessor completes necessary processing including the light emission control. Then, the stop mode is set at the timing after the start, and the run mode is started before detecting the synchronization signal via the synchronization line.

Further, the light receiving section outputs a start signal before outputting the synchronization signal via the synchronization line, and the microprocessor of the light transmitting section detects and activates the start signal via the synchronization line. In addition, the light receiving section has a timing sufficient for the microprocessor of the light transmitting section to be activated in the interval between the synchronization signal and the activation signal.

The microprocessor of the light receiving section enters a stop mode when necessary processing including light emission control is completed, and a processing time for performing all necessary processing including light emission control is determined by a synchronization signal reception time. The stop mode is measured based on
After a certain period of time after the transmission of the received light amount information to the light transmitting unit, the power supply to the light transmitting unit via the synchronization line is temporarily interrupted.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a light receiving unit side of a photoelectric separation type sensor according to an embodiment of the present invention. In the figure, 1 substantially eliminates the polarity of the power supply,
A non-polarizing circuit for eliminating the inconvenience of wiring due to polarization, comprising a plurality of diodes 1a to 1d connected in a bridge, the anode of the diode 1a and the diode 1
The connection point of the cathode of c, the anode of the diode 1b, and the connection point of the cathode of the diode 1d are connected to the power supply / fire signal output terminals T1 and T2, respectively. The power terminal / fire signal output terminals T1 and T2 are connected to a fire receiver or a repeater (hereinafter simply referred to as a receiver) (not shown) by a fire signal line (power line / signal line).

The connection point between the cathode of the diode 1a and the cathode of the diode 1b is connected to the input side of the recovery pulse detection circuit 2 and the constant voltage circuit 6, and the connection point between the anode of the diode 1c and the anode of the diode 1d is It is connected to one of the terminals (negative side) T6.
The constant voltage circuit 6 is a circuit for converting the power supply voltage from the receiver side into a voltage suitable for the operation of the internal circuit on the light transmitting unit side.
The standby power supply terminal T5 (+ side) is a diode 22 for backflow prevention.
And a resistor 23 connected to the output side of the depolarizing circuit 1. Reference numeral 3 denotes a light receiving unit control circuit composed of a microcomputer. The output side of the constant voltage circuit 6 is connected to the power supply + input terminal, and the output side of the recovery pulse detection circuit 2 is connected to the recovery signal detection input terminal. Connected.

Also, the output side of the depolarizing circuit 1, ie, the connection point between the cathode of the diode 1a and the cathode of the diode 1b, the anode of the diode 1c and the diode 1c
A fire indicator light 5 using, for example, a red LED and a fire signal output switching element 4 are connected between the connection points of the anodes of d, and the switching element 4 is opened and closed by a fire signal output from the light receiving section control circuit 3. Controlled.

Between the output side of the constant voltage circuit 6 and the light transmitting section power / sync signal output terminal T7 (+ side), a light transmitting section power switching element 7 and a backflow preventing diode 8 as a first backflow preventing element are provided. Also, a wiring PL for standby power supply is connected between the light transmitting unit power / sync signal output terminal T7 and the output side of the depolarizing circuit 1 by a backflow prevention diode 9 as a second backflow prevention element. Connected via.

The monitoring / adjustment switching pulse receiving circuit 10 is provided between the light transmitting section power supply / synchronous signal output terminals T7 and T8 (-side).
And the synchronous line short-circuit switching element 11 are connected in parallel, the output of the monitoring / adjustment switching pulse receiving circuit 10 is supplied to the monitoring / adjustment mode switching input terminal of the light receiving section control circuit 3, and the synchronous line short-circuit switching element 11 controls the light receiving section. The opening and closing of the circuit is controlled by a synchronous line short-circuit switching operation signal from the circuit 3. The light receiving section control circuit 3 and the monitoring / adjustment switching pulse receiving circuit 10 substantially constitute mode setting means. Further, an indicator lamp for indicating that the mode is the adjustment mode may be provided on the light receiving unit side.

Reference numeral 12 denotes a light receiving element using, for example, a photodiode PD. Reference numeral 13 denotes a light receiving element load resistance connected in parallel to the light receiving element 12.
Are connected to the light receiving amplifier circuit input terminal of the light receiving section control circuit 3 via the light receiving amplifier circuit 14 and the sample / hold (S / H) circuit 15. The light receiving amplifier circuit 14 and the sample / hold circuit 15 receive power from the constant voltage circuit 6.

A bidirectional switch 16 and a unidirectional switch as a mode selection switch are provided between the monitoring distance changeover switch terminal, the monitor / adjustment changeover switch terminal, the light emission period changeover switch terminal and the power supply-side terminal input terminal of the light receiving section control circuit 3. A switch 17 and a unidirectional switch 18 as a cycle selection switch are provided, and a trouble indicator light 19 as an abnormality display means using, for example, a yellow LED is provided between the trouble indicator light terminal and the power-side terminal input terminal. Can be

Reference numeral 20 denotes a trouble signal output switching element, and reference numeral 21 denotes a depolarizing circuit, which comprises a plurality of bridge-connected diodes 21a to 21d. The connection point between the anode of the diode 21a and the cathode of the diode 21c is connected to the diode 21b. The connection points of the anode and the cathode of the diode 21d are connected to the trouble signal output terminals T3 and T4, respectively.

The connection point between the cathode of the diode 21a and the cathode of the diode 21b is connected to the diode 21a.
A trouble signal output switching element 20 is connected to a connection point between the anode of the diode c and the anode of the diode 21 d, and its opening and closing are controlled by the trouble signal output from the light receiving unit control circuit 3.

FIG. 2 is a configuration diagram showing a light transmitting unit side of a photoelectric separation type sensor according to an embodiment of the present invention. In the figure, reference numeral 31 denotes a non-polarizing circuit, which is composed of a plurality of bridge-connected diodes 31a to 31d. The points are connected to the power supply terminal / sync signal input terminals T11 and T12, respectively.

The power supply terminal / synchronization signal input terminals T11 and T12 are connected to a light transmission / reception power supply / synchronization signal output on the light receiving unit side via a light transmission / reception synchronization line (hereinafter referred to as a synchronization line) as a power supply / signal line. It is connected to terminals T7 and T8.
The cathode of the diode 31a and the diode 3
The connection point of the cathode 1b is connected to the input side of the pulse detection circuit 32 for start-up / synchronization / light-receiving voltage and the constant voltage circuit 37.

Reference numeral 33 denotes a light transmitting unit control circuit comprising a microcomputer, the output side of the constant voltage circuit 37 is connected to its power supply + input terminal, and the output side of the pulse detection circuit 32 is connected to its pulse signal detection input terminal. Is done. Also,
For example, a switching element 34 for outputting a monitoring / adjustment mode switching request pulse between an output side of the depolarization circuit 31, that is, a connection point between the cathode of the diode 31a and the cathode of the diode 31b and a connection point of the anode of the diode 31c and the anode of the diode 31d. Is connected, and its opening / closing is controlled by a monitoring / adjustment mode switching output from the light transmission unit control circuit 33.

Reference numeral 35 denotes a non-polarizing circuit, 36 denotes a fire test signal input circuit, and the non-polarizing circuit 35 includes a plurality of bridge-connected diodes 35a to 35d, and includes an anode of the diode 35a and a cathode of the diode 35c. The connection point and the connection point between the anode of the diode 35b and the cathode of the diode 35d are connected to the fire test signal input terminals T13 and T14, respectively.

The connection point between the cathode of the diode 35a and the cathode of the diode 35b and the diode 35
A fire test signal input circuit 36 is provided between the connection point of the anode of the diode c and the anode of the diode 35d, and the output thereof is supplied to the fire test signal input terminal of the light transmission unit control circuit 33.

A light-emitting element current switch 38, a light-emitting element switching element 39 and a near-infrared LED, for example, are connected between the output side of the constant voltage circuit 37, that is, between the power supply + input terminal and the power supply-input terminal of the light transmitting section control circuit 33. Light emitting element 4 used
0 is connected in series. The light emitting element current switch 38 comprises a plurality of switchable light emitting current setting resistors provided in parallel, and the light emitting element switching element 39 controls the opening and closing of the light emitting element switching output from the light transmitting section control circuit 33. Is done.

A current-limiting resistor 41, a conduction indicator light switching element 42, and a green LED, for example, are provided between the power supply + input terminal and the power supply-input terminal of the light transmission unit control circuit 33.
Are connected in series. Similarly, a current-limiting resistor 44, a test indicator switching element 45, and a test indicator 46 using, for example, a red LED are connected in series. A charging electrolytic capacitor 47 is connected in parallel.

It should be noted that the energizing indicator light switching element 42 and the energizing indicator 43 are substantially turned on when a period signal indicating the period selected on the light transmitting unit side is output from the light receiving unit side via the synchronization line. The light emitting side display means for receiving the periodic signal and discriminating the light emitting cycle. A display means for distinguishing the selected cycle may be provided on the light receiving unit side.

Then, the power indicator lamp switching element 42
The opening and closing of the test indicator light switching element 45 are controlled by the output of the energizing indicator light switching element and the output of the test indicator light switching element from the light transmitting unit control circuit 33, respectively. Reference numeral 48 denotes a mode change switch, that is, a monitor / adjustment mode changeover switch. When the switch is off, for example, the mode is not changed, and when it is on, the mode is changed (monitoring → adjustment mode or vice versa). is there.

Reference numeral 49 denotes an output side of the constant voltage circuit 37, that is, between the power supply + input terminal and the power supply-side input terminal of the light transmission section control circuit 33, and receives a light receiving level output from the light transmission section control circuit 33. A light receiving level output circuit 50 is a light receiving amount display voltmeter which is detachably connected to the output side of the light receiving level output circuit 49 via terminals T17 and T18. The standby power terminal T15 (+ side) is connected to the power terminal / synchronous signal input terminal T11 via the backflow prevention diode 51 and the resistor 52, and the standby power terminal T16 (-side) is directly connected to the power terminal / sync signal input terminal. Connected to T12.

Next, the operation will be described. First, the overall operation of the photoelectric separation type sensor will be described. At the time of normal monitoring, the power supply voltage is supplied from the receiver to the light receiving section via the fire signal line while the fire signal output switching element 4 is off, and the light receiving section switches the non-polarizing circuit 1 to the power supply voltage. The constant voltage circuit 6 converts the power supply voltage into a voltage suitable for the operation of the light transmitting unit side internal circuit, and supplies the voltage to the light transmitting unit via a synchronous line as power. At this time,
The light transmitting unit power supply switching element 7 is on, and the synchronous line short circuit switching element 11 is off.

When the light receiving section control circuit 3 receives the command from the output of the monitoring period timer as an internal timer means (not shown), it inverts the states of the switching elements 7 and 11 for a predetermined time, for example, 5 ms. , The power supply is cut off and the line is short-circuited, so that the voltage of the synchronous line becomes 0,
A synchronization pulse having a width of 5 ms can be reliably transmitted to the light transmitting unit.

Thereafter, the light receiving section repeats the above operation for each output of the monitoring cycle timer. Then, the light receiving section control circuit 3 receives the light by the light receiving element 12 in synchronization with the above-mentioned synchronization pulse,
If it is determined that a fire has occurred based on the amount of light received through the light receiving amplifier circuit 14 and the sample / hold circuit 15, the fire signal output switching element 4 is turned on, the fire indicator light 5 is turned on, and the terminals T1 and T2 are connected. A fire is reported to a receiver (not shown) connected via a fire signal line (not shown).

Further, the voltage supplied from the light receiving unit side of the light transmitting unit side is stabilized by the constant voltage circuit 37. However, the energization indicator lamp switching element 42 is normally off, that is, in a cutoff state, and the energization indicator lamp 43 is in an extinguished state. When the synchronization pulse is sent from the light receiving section, the voltage detection circuit 37
Then, the light transmitting unit control circuit 33 turns on the energizing indicator light switching element 42 in a predetermined pattern and supplies power to the energizing indicator 43, so that the energizing indicator 43 blinks, The side will emit light.

Here, the light emission time of the light transmitting unit after receiving the synchronization pulse is about 100 μsec, and the difference between the transmission periods of the plurality of different synchronization signals prepared differs from the light emission of the light transmitting unit to the light receiving unit. Is required at least about 20 milliseconds until the light is received, and the accuracy of each transmission cycle is ± 1%. And
Each transmission period is about 3 seconds. For example, when the nominal value of the light emission period is 2.9 seconds and 3.0 seconds, the accuracy of the synchronous pulse transmission time is 1% on soil, so 2.9 seconds is between 2.87 and 2.93 seconds, nominally 3.0 seconds is 2.9
A synchronization pulse is sent to the light-sending unit between 7 and 3.03 seconds, and the light-sending unit starts emitting light with a required time of 100 μs. In addition, the opposing light receiving unit side receives light emitted from the light transmitting unit for 20 msec from the start of transmitting the synchronization pulse to the light transmitting unit, which is the time required to make a fire determination. In other words, since the light receiving unit side is the time required from the reception of the light from the opposing light transmitting unit to the judgment of fire, 20 ms after the issuance of the synchronization pulse, the time during which the light from the other light transmitting unit must not be received. It is.
The remaining time of one cycle excluding the 20 ms is a standby time, in which no light is received, so that there is no problem even if light other than that of the opposing light transmitting unit is received.

In addition, the light receiving section is used for reliable fire judgment.
A fire determination is not made only by a single received light amount, but an average of several received light amounts before and after that is used for the fire determination. It is not possible to prevent two adjacent detectors from overlapping light emission even once, but overlapping light emission only once does not significantly affect the average value of received light for fire judgment. If it does not overlap several times or more from the cycle of, the normal fire judgment is continued and monitoring is continued.

The sensor whose nominal value is set to the 2.9 second side has an error, so that even if the processing moves backward, the sensor moves from 2.93 seconds to 2.93 seconds.
The light receiving time is 20 ms up to 95 seconds, while the side set to the nominal value of 3.0 seconds is 2.97 seconds even if the synchronization pulse transmission due to the error moves forward. Thus, even if there is a cycle in which light emission overlaps, in the next cycle, the sensor with the nominal setting of 2.9 seconds always stops receiving light by 2.95 seconds, and the sensor with the nominal setting of 3.0 seconds has at least two. .9
The light-emitting unit does not emit light until 7 seconds later, so that the light-emissions of the adjacent sensors overlap twice or more consecutively, and it is possible to prevent the light-receiving unit on the other side from receiving light and erroneously determining the fire. The light emission that overlaps once overlaps theoretically after the least common multiple of 2.9 seconds and 3.0 seconds, that is, 87 seconds, that is, 1.5 minutes later, which is the number for fire monitoring. There is no problem at all because it is sufficiently longer than the time of about several tens of seconds required to obtain the average of the period.

If the reference is 2 seconds, the difference between the nominal values of the light emission periods does not overlap even if the difference is 50 ms. In this case, the accuracy is ± 1%, between 1.93 and 1.97 seconds, and 1.9.
Light is emitted in a width of 100 μs between 8 and 2.02 seconds. Thus, when checking that the light emission cycle and light emission timing are different from those of the adjacent sensor after installing the sensor, check whether the lighting method of the indicator light differs between the adjacent sensors. By doing so, you can understand.
In other words, in order to be able to install the light-sending and light-receiving parts of adjacent photoelectric separation type sensors in the same direction, set the light emission cycle and light emission timing in several ways, and display the setting contents by blinking the indicator lamp. It can be displayed in the way of making.

In the present embodiment, the indicator light indicating the set contents is also used as the energization indicator lamp 43. However, even if a dedicated indicator for setting display is used, other indicator lamps such as other energization indicator lamps may be used. You may also be used. The light emitted from the light transmitting unit is received by the opposing light receiving unit through the monitoring space (smoke detection space). On the light receiving unit side, the light from the light transmitting unit side is received via the light receiving element 12, the output is amplified by the light receiving amplifier circuit 14, and only the pulse of the light emission time is sampled / held by the sample / hold circuit 15 and the light receiving unit Input to the control circuit 3.

The light receiving section control circuit 3 takes in the output of the sample / hold circuit 15 through the input terminal of the light receiving and amplifying circuit, performs A / D conversion, converts it into a 6-bit binary code, and, based on the code, transmits the power to the light transmitting section power supply. Switching element 7 off,
The synchronous line short-circuit switching element 11 is turned on to form a pulse, and the received light amount information is transmitted to the light transmitting unit. At this time, the pulse representing the received light amount information is, for example, 1 ms so as to be distinguishable from the pulse representing the synchronization signal (synchronization pulse) by the pulse width as shown in FIG.

When the light transmitting section receives the coded pulse, the pulse detection circuit 32 captures the pulse and transmits the pulse to the light transmitting section control circuit 33. The light transmitting section control circuit 33 is based on the information amount. D / A conversion is performed so that a voltage can be output, and the voltage is output to the voltmeter connection terminals T17 and T18 via the light receiving level output circuit 49. Therefore, if the light reception amount indicating voltmeter 50 is connected to the connection terminals T17 and T18, the light reception amount can be confirmed on the light transmitting unit side. The amount of received light is a physical quantity other than voltage (for example, current, frequency,
Pulse width, phase, etc.)
Alternatively, an LED may be incorporated in the light transmitting unit itself to indicate the lighting state.

With this function, the worker on the light transmitting unit side can know the received light amount at hand without asking the worker on the light receiving unit side or re-laying the electric wire. Thus, the optical axis can be surely adjusted.

Normally, the light receiving section sends a negative synchronization pulse as shown in FIG. 5 to the light transmitting section based on the output of the monitoring cycle timer in the light receiving section control circuit 3. The light transmitting unit captures the falling of the synchronization pulse by the pulse detection circuit 32 and notifies the light transmitting unit control circuit 33 that a light emission command has been received from the light receiving unit. The light transmitting unit control circuit 33 receives this, turns on the light emitting element switching element 39, and supplies the voltage of the constant voltage circuit 37 to the light emitting element 40 via the light emitting element current switch 38, thereby sandwiching the sensing space. Light is emitted toward the light receiving section.

Upon receiving this light emission, the light receiving section side receives the light receiving element 12.
Converts this light emission into an electric signal. Then, the electric signal is amplified by the light receiving amplifier circuit 14, sampled / held by the sample / hold circuit 15, and A
The received light amount is converted into a digital amount by the / D conversion and stored in an internal memory (not shown). Further, this digital amount is transmitted to the light transmitting unit as received light amount information including a plurality of pulses P1 to P6, for example, as shown in FIG. Here, as an example, the pulses P1 to P5 represent the light receiving voltage, and P6 represents the period and mode, respectively.

The light transmitting unit starts these pulses, synchronizes them,
Detected by the received light voltage pulse detection circuit 32, D / A conversion is performed via the light transmission unit control circuit 33, and the voltmeter connection terminal T 17
The received light amount is displayed in the form of a voltage on the received light amount display voltmeter 50 connected to T18 and T18, and the worker on the light transmitting unit side is notified.
At this time, if the monitoring / adjustment switch 48 of the normally closed type is not switched, the operation waits until the next light emission cycle time.

The operator on the light transmitting section operates the monitor adjustment switch 48.
Is switched from off to on, the voltage change due to the operation of the switch 48 is detected by the monitor / adjustment switch terminal of the light transmitting unit side control circuit 33, and it is recognized that the switch has been switched. After receiving the received light amount pulse on the synchronous line, the light transmitting unit control circuit 33 turns on the monitoring / adjustment mode switching request pulse output switching element 34 to short-circuit the synchronous lines with low impedance, as shown in FIG. The monitoring adjustment mode switching request pulse of such negative polarity is transmitted.

After the light receiving unit sends the received light amount information to the light transmitting unit, the monitor / adjustment switching pulse receiving circuit 10 detects that the current flowing between the synchronization lines has increased, and the mode of the light receiving unit control circuit 3 is changed. It is possible to recognize that a mode switching request has been input from the light transmitting unit side by being input to the switching input terminal, and the mode can be switched from the next monitoring.

With this function, the worker on the light transmitting unit side can
After the work of adjusting the optical axis of the light transmitting unit and adjusting the amount of received light, it is possible to switch from the adjustment mode to the monitoring mode without going to the light receiving unit, thereby shortening the working time.

If the operator forgets to switch to the monitoring mode after erroneously adjusting the optical axis, the photoelectric separation type sensor does not detect a fire, so that the monitoring area of the sensor is unwatched. Therefore, when a certain period of time (for example, one hour) has elapsed since the adjustment mode was selected, such a disadvantage can be solved by automatically switching to the monitoring mode.
Therefore, the monitor / adjustment changeover switch 48 is a mode change switch for localization / mode change. When adjusting the optical axis of the sensor, if the sensor is in the monitoring mode, the operator operates the mode change switch to the mode change side to set the mode to the adjustment mode.

When the sensor enters the adjustment mode, the counting is performed by software in this embodiment, but the time during which the adjustment mode is executed is measured by the timer of the microcomputer with the built-in sensor. . After the optical axis adjustment is completed, the operator returns to the monitoring mode by the mode change switch to complete the optical axis adjustment, but if the operator forgets to return to the monitoring mode by mistake, the adjustment mode execution time e.g., one hour elapses. Then, by automatically switching to the monitoring mode, forgetting to switch the mode can be prevented. In addition, when the monitoring mode is entered while the optical axis adjustment is incomplete, a failure signal (trouble signal) is sent from the detector to the receiver, indicating that the monitoring is not performed. .

Therefore, even if the switching from the adjustment mode to the monitoring mode is mistakenly forgotten, the fire can be reliably detected. Further, when the optical axis adjustment is incomplete, the failure signal may be transmitted to indicate a poor optical axis adjustment.

As described above, the light transmitting section detects a pulse as information on the amount of light received from the light receiving section, and the light transmitting section control circuit 33 detects the pulse.
Is converted to D / A, and is displayed on the voltmeter 50 as a received light amount in the form of a voltage. This voltage passes through the constant voltage circuit 6 on the light receiving unit side and the power supply switching element 7 on the light transmitting unit, and is normally 6 V to 8
V or so. On the other hand, the voltage of the standby power supply is usually 24 V, and there is a voltage difference close to 18 V. Therefore, at least one of the standby power supply terminals T15 and T16 provided on the light transmitting unit side as described above is connected to the backflow prevention diode 5 in this case.
1 and a synchronous line via a current limiting resistor 52.

Further, a diode 9 for preventing a backflow from the synchronous line to the constant voltage circuit 6 is inserted on the light receiving unit side and a diode 8 for preventing a backflow from flowing from the power supply switching element 7 for the light transmitting unit to the constant voltage circuit 6. Is inserted. Accordingly, when the standby power supply is connected to the standby power supply terminals T15 and T16 on the light transmission unit side, power is also supplied to the light reception unit side through the synchronization line, and the synchronization line short-circuit switching element 11 and the light transmission unit on the light reception unit side are connected. Even when the switching element 34 for monitoring / adjustment mode switching request pulse output on the unit side short-circuits the synchronous lines with low impedance, the line voltage remains at the standby power supply terminal T1.
5, a similar pulse waveform is formed in which only the normal voltage (the portion other than the negative pulse) is high as shown by the broken line in FIG.

Also, the pulse detection circuit 32 on the light transmitting section side
Since the case where the voltage drops to about V or less is detected, the operation is the same as when power is supplied from the receiver. Therefore, it becomes possible to perform all the functions of the photoelectric separation type sensor other than the fire signal output by the standby power supply connected to the light transmitting unit side.

With this function, the worker on the light transmitting unit side can
After the work of adjusting the optical axis of the light transmitting unit and adjusting the amount of received light, the standby power supply can be immediately removed, so that it is not necessary to go to the light receiving unit side, and the working time can be reduced.

Further, in the present embodiment, the pulse P shown in FIG. 5 is used in order to surely grasp the monitoring / adjustment mode switching request from the light transmitting unit and reduce the current consumption.
7 is used. The pulse P7 is generated by turning off the normally-closed light-transmitting-part power supply switching element 7 for a predetermined time while keeping the synchronous line short-circuit switching element 11 on the light-receiving part off. That is, in FIG. 5, the power supply switching element 7 is turned off at time t1 and turned on at time t3, and power is not supplied during the time period of the pulse P7. Only the charges that have been charged to the charges of the line capacitance of the cable (power supply line and signal line) connecting the light transmitting unit side and the light receiving unit side remain. That is, during the pulse width period of the pulse P7, the electric charge of the line capacitance of the cable is changed from the output terminal 17 to the monitoring / adjustment switching pulse receiving circuit 1.
Since the sensing current of the monitoring / adjustment switching pulse receiving circuit 10 flows through the path from 0 to the output terminal 18 and consumes electric charge, the waveform substantially becomes as shown in FIG.

At this time, if the monitor / adjustment changeover switch 48 is operated on the light transmitting unit side and the monitoring / adjustment mode changeover request pulse output switching element 34 is turned on, the synchronous line is short-circuited, and only for the time of the short-circuiting The line voltage becomes 0 V, and the pulse P7 is output from time t2 to time t2 as indicated by the broken line in FIG.
The waveform has a voltage of 0 V during 3.

On the light receiving section side, the monitoring / adjustment switching pulse receiving circuit 10 detects a voltage drop near 0 V, thereby detecting
It is possible to know that there has been a mode switching request from the light transmitting unit side. Further, since the light transmitting unit power switching element 7 is off, the current supplied from the receiver side does not need to be consumed.

When the light transmitting unit power supply switching element 7 is turned on and the light transmitting unit sends a similar pulse P7, the constant voltage circuit 6 on the light receiving unit also transmits the same pulse P7 during the transmission of the pulse. Since the current flows through the monitoring / adjustment mode switching request pulse output switching element 34, the power supplied from the receiver side is consumed more. Further, since the voltage is continuously supplied from the constant voltage circuit 6, this switching is performed. It is difficult to reduce the voltage to 0 V only with the element 34.

Therefore, after a certain period of time after the light-receiving unit has finished sending the light-receiving amount information, only the light-transmitting-unit power switching element 7 is temporarily turned off on the light-receiving unit, so that the light-receiving unit is closer to the light-transmitting unit The transmitted monitoring / adjustment mode switching request pulse can be more reliably received, and the current consumption can be suppressed by short-circuiting the synchronous lines while supplying power to the light transmitting unit. .

Next, the operation of the light receiving section control circuit 3 on the light receiving section side will be described in detail with reference to FIG. The microcomputer initializes and reads the cycle setting related to the light emission cycle stored in the internal memory in advance (step S1), and sends out the light emission control, that is, a synchronization pulse as shown in FIG. 5 to the light transmitting unit side (step S2). .

Then, the light emitting element 40 emits light on the light transmitting section side,
The emitted light is received by the light receiving element 12 and the light receiving amplifier circuit 14
The signal is input to the light receiving section control circuit 3 via the sample / hold circuit 15, where the light receiving voltage is measured (step S3), and the light receiving voltage and period / mode information as shown in FIG. 5 are transmitted (step S4). ). These pieces of information are output at a timing based on the synchronization signal.

Next, the mode change switch, that is, the monitor / adjustment mode changeover switch 17 is checked (step S).
5) If it is a change, change the mode (step S6)
The process proceeds to step S7, and if it is in the localization state, the process directly proceeds to step S7. In step S7, the mode is checked.
If it is in the adjustment mode, the trouble indicator light 19 is turned on (step S8), the elapsed time from the setting of the adjustment mode is measured (step S9), and it is determined whether a prescribed time, for example, one hour has elapsed. (Step S10) If the specified time has elapsed, the trouble light may continue to be lit because the switching after the adjustment is mistakenly forgotten or the optical axis adjustment is incomplete, etc. Mode is forcibly changed (step S11), and the process proceeds to step S31.
If the prescribed time has not elapsed, step S31 is performed as it is.
Proceed to. On the other hand, if the mode is the monitoring mode in step S7, the calculation of the dimming rate is performed according to the following equation (step S12).

Dimming rate = (reference value−light receiving voltage) / reference value (1)

The reference value in the equation (1) is updated at a predetermined update time, for example, every hour after the power is turned on, and is the value of the amount of received light (light receiving voltage) received first after the power is turned on or after the update. , The light reception voltage is the value of the current light reception amount.

Next, a fire judgment is made from the fire sensitivity preset in the internal memory by operating the monitoring distance changeover switch 16 and the extinction ratio calculated in step S12.
If the extinction ratio is equal to or higher than the predetermined fire sensitivity, it is determined that a fire has occurred, and if the extinction ratio is lower than the fire sensitivity, it is determined that a fire has not occurred (steps S13 and S1).
4). If a fire occurs, a fire signal output is generated, the fire signal output switching element 4 is turned on, and a fire indicator light 5 is output.
Is turned on, and the fact is notified to the receiver (step S15), and the process proceeds to step S16. If it is not a fire, the process directly proceeds to step S16.

In step S16, it is determined whether or not the reference value update time has elapsed. If not, the process proceeds to step S20 to wait, and if it has elapsed, a new reference value is calculated (step S17). It is determined whether or not the new reference value is normal (step S18). If the new reference value is normal, the reference value is updated and the value is stored in the memory (step S18).
19) If not normal, the process proceeds to step S20 without updating the reference value.

Then, an abnormality is determined (step S2).
0), it is determined whether the reference value or the amount of received light is abnormal (step S21). If it is not abnormal, the process waits until the next light emission time (step S31), and if abnormal, an abnormal signal is output (step S22). It is determined whether the amount of received light is excessive as a type of abnormality (step S23). If it is excessive, that is, if the amount of received light exceeds a reference value (received light amount is saturated), the trouble lamp 19 is turned on (step S24). After waiting for a predetermined time, for example, 200 ms (step S25), the trouble lamp 19 is turned on again (step S26), and similarly, the trouble lamp 19 is turned on (steps S28, S30) and 2
00ms standby (steps S27, S29) is repeated,
It waits until the next light emission time (step S31). That is, the trouble lamp 19 blinks four times when the amount of received light is saturated.

If the amount of received light is not excessive in step S23, it is determined from the magnitude of the amount of received light or the like whether or not the type of abnormality is contamination (step S32). Step S26), waiting for 200 ms (step S27), and thereafter similarly turning on the trouble lamp 19 (steps S28 and S30) and waiting for 200 ms (step S29), and waiting until the next light emission time (step S31). That is, in the case of soiling, the trouble light 19 blinks three times.

On the other hand, if it is determined in step S32 that the light is not contaminated, that is, it is determined that the light is in a light-shielded state, the trouble lamp 19 is turned on (step S28), and a wait of 200 ms (step S2).
8) Then, the trouble lamp 19 is turned on again (step S3).
0), and waits until the next light emission time (step S3)
1). That is, in the case of shading, the trouble lamp 19 blinks twice. Then, after step S31, the operation enters the monitoring mode, returns to step S2, and repeats the above operation.

In these operations, the type of abnormality is represented by the number of trouble lamps, and the correspondence between the number of times and the type is not limited to that of the present embodiment. Then, the type of the abnormality may be added.

The above description is for the case where an abnormality is determined on the light receiving unit side and the trouble lamp is turned on on the light receiving side. Even trouble lights can be provided. In addition, since the light-sending unit receives light-receiving information from the light-receiving unit via the synchronization line, abnormality determination can be performed by the light-sending unit. The trouble lamp on the light receiving unit side may be controlled via a line.

Next, the operation of the light transmitting section control circuit 33 on the light transmitting section will be described in detail with reference to FIG. The microcomputer is initialized (step S41), and it is determined whether or not a stop release signal, that is, a negative start pulse as shown in FIG. 5 has been received from the light receiving section (step S42). When the start pulse is received, the stop of the clock pulse of the light transmitting unit control circuit 33, that is, the microcomputer, which has stopped the generation of the clock pulse is released, and the clock pulse is generated.

Next, in step S2 (FIG. 3), it is determined whether or not the synchronization pulse transmitted from the light receiving section has been received (step S43). From the receiver side, depolarizing circuit 3
5 and whether or not a fire test signal has been received via the fire test signal input circuit 36 (step S44).
The test indicator light switching element 45 is turned on to emit the light emitting element 40 and the test indicator light 46, respectively (step S45), and the energizing indicator light switching element 42 is turned on to emit the energizing indicator lamp 43 (step S45).
47).

On the other hand, if the reception in step S44 is not a fire test signal, it is said that the light emission is in the normal mode, so that the light emitting element switching element 39 is turned on to emit light from the light emitting element 40 (step S46), and furthermore, the energization indicator lamp The switching element 42 is turned on to emit the power indicator lamp 43 (step S47).

Next, in step S4 (FIG. 3), it is determined whether or not the received light voltage data transmitted from the light receiving section has been received (step S48). Then, the received light voltage data is output to the connection terminals T17 and T18 via the sensor output terminal, that is, the received light level output circuit 49 (step S49).
If the voltmeter 50 for displaying the amount of received light is connected to these terminals, the amount of received light can be confirmed on the light transmitting unit side. This voltmeter 5
The display of the received light amount at 0 may be either a level or a number.

Similarly, in step S4 (FIG. 3), it is determined whether or not the cycle / mode information transmitted from the light receiving unit has been received (step S50). , Upon reception, these cycle / mode information are stored as data in an internal memory (step S51).

Next, the mode change switch, that is, the monitor / adjustment switch 48 is checked (step S52).
If the monitoring / adjustment mode changeover switch 48 is off, the mode is not changed and the camera is in the localization state (monitoring mode).
When the monitoring / adjustment mode changeover switch 48 is turned on, the mode is changed (adjustment mode). Therefore, a mode change request signal, that is, a monitoring / adjustment mode change request pulse as shown in FIG. (Step S53), and waits for a predetermined time, for example, 200 msec.

Next, the mode is confirmed (step S5).
5) If the mode is the monitoring mode, the light emission cycle of the monitoring mode is checked (step S56), and if the cycle is the first set cycle, for example, 3.0 seconds, or if the mode is the adjustment mode in step S55, Both switching indicators 4
2 is turned on, and the energization indicator lamp 43 emits light (step S5).
7) Then, the apparatus enters a waiting state for an elapsed time of 200 ms (step S58). If the cycle is the second set cycle, for example, 2.9 seconds in step S56, the apparatus waits for the elapsed time of 200 ms in step S58. Enter the state.

Similarly, the mode is confirmed again (step S59). If the mode is the adjustment mode, the energizing indicator light switching element 42 is turned on to emit the energizing indicator 43 (step S60), and then the process proceeds to step S61. If the mode is the monitoring mode, the process directly proceeds to step S61.

That is, the number of times of light emission of the energization indicator lamp 43 is one in each light emission cycle when the light emission cycle is 2.9 seconds in the monitoring mode, and twice in each light emission cycle when the light emission cycle is 3.0 seconds. It emits light, and in the adjustment mode, it emits light three times every light emission cycle. When the necessary processing including the light emission control is completed, the stop mode is executed in step S61,
Stop generating clock pulses. That is, the processing mode is set to the stop mode by measuring the processing time in which all necessary processing including the light emission control can be performed with reference to the reception of the synchronization signal. This allows
The current consumed when a clock pulse is constantly generated can be saved. The stop mode may be provided in the light receiving unit control circuit 3 on the light receiving unit side.

FIG. 8 is a circuit diagram showing a specific example in the case of performing a remote operation test of a photoelectric separation type sensor. In the figure,
T19 is an input terminal to which a normal light emitting element switching output is applied from the light transmitting unit control circuit 33, T20 is an input terminal to which a test light emitting element switching output is applied from the light transmitting unit control circuit 33, 60 is an OR circuit, 61 Is an AND circuit. One input terminal of the OR circuit is an input terminal T19.
The other input terminal is connected to the output terminal of the AND circuit 61, and its output is connected to the light emitting element switching element 3.
9 is applied as a switching signal.

Further, one input terminal of the AND circuit 61 is connected to the input terminal T20, and the other input terminal is grounded via the overvoltage protection resistor 62 and the capacitor 63. The input terminal T20 is connected to a connection point between the resistor 62 and the capacitor 63 via the inverter 64 and the resistor 65. Note that the resistor 65 and the capacitor 63 constitute a time constant circuit. Component 6
1 to 65 substantially constitute a pulse shortening circuit.

Next, the operation of this circuit will be described with reference to FIG. During normal operation, a pulse signal of a predetermined width is applied to the input terminal T19 as a normal light emitting element switching output from the light transmitting unit control circuit 33, and this pulse signal is switched to the light emitting element switching element 39 via the OR circuit 60. Supplied as a signal.

On the other hand, during the test operation, the light transmitting unit control circuit 33
For example, a test pulse signal P11 having substantially the same pulse width as a normal pulse signal as shown in FIG. 9A is applied to an input terminal T20 as a test light emitting element switching output from the input terminal T20. The pulse signal P12 is directly applied to one input terminal and inverted by the inverter 64. The pulse signal P12 having a falling slope determined by the time constant of the resistor 65 and the capacitor 63 as shown in FIG. Circuit 61
Is applied to the other input terminal.

As a result, on the output side of the AND circuit 61, the pulse width of the pulse signal P11 determined substantially by its threshold is reduced to about 70% of the pulse width of FIG. 9C.
The pulse signal P13 having the reduced pulse width is output as a test pulse signal via the OR circuit 60 through the light emitting element switching element 3 as shown in FIG.
9.

In this case, the pulse width of the pulse signal P13 as the test pulse signal can be arbitrarily set by changing the values of the resistor 65 and the capacitor 63 constituting the time constant circuit. Further, this pulse width can be changed only by creating software by using a microcomputer.

In the test operation, the light emitting element switching element 39 shown in FIG. 2 is turned on by the test pulse signal having a reduced pulse width, and the light emitting element 40 emits light. The light is received at 46, amplified by the light receiving amplifier circuit 14, sampled by the sample / hold circuit 15, and supplied to the light receiving unit control circuit 3. The normal light receiving unit amplifier circuit 14 eliminates the influence of noise such as external light. Therefore, the pulse width of the optical signal from the light transmitting unit side (for example, 100
μs) is a filter amplifier that amplifies mainly in the frequency band.

Therefore, if the pulse width of the test pulse signal is changed (for example, 10 μs or 1 ms) during the test operation as described above, the output of the light receiving and amplifying circuit 14 has the effect of the filter even if the emission current is constant. It is reduced by Thus, by changing the pulse width of the optical signal from the light transmitting unit, that is, the pulse width of the test pulse signal, even if the emission current is constant, the output of the light-receiving amplifier circuit is reduced by the effect of the filter, and a simulated fire is caused. The remote operation test of the photoelectric separation type sensor can be easily performed. In the above embodiment, the fire signal is transmitted by turning on the fire signal output switching element 4 of the light receiving unit to the fire receiver or the like. The switching element 4 may be replaced with a transmission circuit. In the case of an analog system, a signal representing an analog value may be transmitted.

[0107]

As described above, according to the present invention, the light receiving unit detects the amount of light received from the light transmitting unit and outputs a light receiving signal indicating the received light amount to the synchronization line. Since the unit receives the received light signal from the synchronization line and outputs the received light amount, the worker on the light sending unit side does not ask the light receiving unit worker about the received light amount or lay the wire again, Since the amount of received light can be known at hand, more accurate and reliable optical axis adjustment can be performed, and there is an effect that work efficiency can be improved.

Further, according to the present invention, the light receiving section has mode setting means for setting a state between the monitoring mode and the adjustment mode, and the light transmitting section has a mode for switching between the monitoring mode and the adjustment mode. A light transmission unit,
When detecting the operation of the mode changeover switch, a mode changeover signal is output to the synchronization line, and the light receiving section receives the mode changeover signal from the synchronization line to set the monitoring mode or the adjustment mode of the mode setting means to the other. Since the switching is performed, the worker on the light transmitting section can switch from the adjustment mode to the monitoring mode without having to go to the light receiving section after completing the light axis adjustment and the light receiving amount adjustment work of the light transmitting section, thereby shortening the working time. There is an effect that it can be achieved.

Further, according to the present invention, the light receiving unit is connected to the power line and the signal line from the receiving unit, and supplies power to the light transmitting unit via the synchronous line. It has a standby power supply terminal that connects to the power line, and the light receiving unit has a path that connects to the power supply line by preventing backflow from the synchronization line. After the adjustment work is completed, the standby power supply can be immediately removed, so that there is no need to go to the light receiving unit side, and the working time can be shortened.

Further, according to the present invention, the mode setting means for setting the state of the monitoring mode and the adjusting mode, the mode setting means is activated when the adjusting mode is set, reset when returning to the monitoring mode, and is reset for a predetermined time. Timer means for outputting a timer when the time elapses. Since the mode setting means is switched to the monitoring mode based on the timer output from the timer means, even if the switching from the adjustment mode to the monitoring mode is mistakenly forgotten, a fire detection is performed. And the unmonitored state can be prevented.

Further, according to the present invention, the light transmitting section has a microprocessor, and the microprocessor detects a synchronization signal from the light receiving section via a synchronous line and controls light emission of the light transmitting section. Wherein the microprocessor is
The stop mode is set at the timing after the necessary processing including the light emission control is completed, and the system can be started in the run mode before detecting the synchronization signal via the synchronization line, so that there is no need to constantly generate a clock pulse. Therefore, there is an effect that the current consumption can be saved correspondingly.

Further, according to the present invention, the light receiving unit temporarily suspends the power supply via the synchronization line to the light transmitting unit after a fixed time after transmitting the received light amount information to the light transmitting unit. As a result, the monitoring / adjustment mode switching request pulse sent from the light transmitting unit side can be more reliably received as a voltage drop at the light receiving unit side, and the synchronization line can be received while power is supplied to the light transmitting unit side. Since a short circuit is prevented, unnecessary current consumption can be suppressed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an example of a light receiving unit side according to an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating an example of a light transmitting unit side according to an embodiment of the present invention;

FIG. 3 is a flowchart for explaining the operation of the light receiving section according to the embodiment of the present invention;

FIG. 4 is a flowchart for explaining the operation of the light transmitting unit according to the embodiment of the present invention.

FIG. 5 is a diagram showing a signal waveform in one embodiment of the present invention.

FIG. 6 is a diagram showing a signal waveform in one embodiment of the present invention.

FIG. 7 is a diagram showing a signal waveform in one embodiment of the present invention.

FIG. 8 is a circuit configuration diagram showing an example of a main part according to an embodiment of the present invention.

FIG. 9 is a diagram provided for explanation of the operation in FIG. 8;

[Explanation of symbols]

1, 21, 31, 35 Non-polarity circuit, 3 Light receiving section control circuit, 4 Fire signal output switching element, 5 Fire indicator light, 6, 37 Constant voltage circuit, 7 Light transmission section power switching element, 8, 9, 22 Backflow Prevention diode, 10 monitoring / adjustment switching pulse receiving circuit, 11
Synchronous line short-circuit switching element, 12 light receiving elements, 14
Light receiving amplifier circuit, 15 sample / hold circuit,
17 monitoring / adjustment changeover switch, 18 emission cycle changeover switch, 19 trouble light, 32 pulse detection circuit, 33 light transmission unit control circuit, 34 switching element for monitoring / adjustment mode switching request pulse output, 39 light emitting element switching element, 40 light emission Element, 42
Normal indicator light switching element, 43 current indicator light,
45 test indicator light switching element, 46 test indicator light, 50 voltmeter for received light amount display.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G059 AA05 BB01 CC19 CC20 EE01 FF06 GG02 HH01 KK01 MM03 MM05 MM06 MM09 MM10 MM11 PP04 2G065 AA04 AB02 AB14 AB23 AB28 BA09 BB44 BC04 BC08 BC17 BC20 BC22 BC28 BC33 BC35 AB03 AC03 AC07 BA32 CA07 CA13 CA15 CA17 CA18 CA22 CA30 DA07 DA08 DA11 DA13 DA16 DA17 EA11 EA24 EA30 EA31 EA38 EA39 EA43 EA46 EA53 EA54

Claims (24)

[Claims] 1. A light transmitting unit and a light receiving unit provided opposite to the light transmitting unit with a smoke detection space interposed therebetween, for synchronizing light emission of the light transmitting unit and light reception of the light receiving unit. Synchronous line is connected, in a photoelectric separation type sensor that outputs fire information based on the amount of light received by the light receiving unit with respect to light emission of the light transmitting unit changes due to the presence of smoke, the light receiving unit includes: Detecting the amount of light received from the light transmitting unit and outputting a light reception signal indicating the amount of received light to the synchronization line;
The light transmitting unit receives the light receiving signal from the synchronization line and outputs a light receiving amount. 2. The photoelectric separation type sensor according to claim 1, wherein the light receiving signal is a coded pulse signal. 3. The photoelectric separation type sensor according to claim 1, wherein the output of the amount of received light in the light transmitting unit is a voltage output to an output terminal. 4. The photoelectric separation type sensor according to claim 1, wherein the output of the amount of received light in the light transmitting unit is displayed on a display unit by a level or a numeral. 5. The light-receiving section outputs a synchronization signal to a synchronization line at a predetermined cycle, and the light transmission section receives the synchronization signal from the synchronization line and emits light. The photoelectric separation type sensor according to any one of claims 1 to 3. 6. The photoelectric separation type sensor according to claim 5, wherein the light receiving signal is output at a timing based on the synchronization signal. 7. A light transmitting unit, and a light receiving unit provided opposite to the light transmitting unit with a smoke detection space interposed therebetween, for synchronizing light emission of the light transmitting unit and light reception of the light receiving unit. Synchronous line is connected, in a photoelectric separation type sensor that outputs fire information based on the amount of light received by the light receiving unit with respect to light emission of the light transmitting unit changes due to the presence of smoke, the light receiving unit includes: A mode setting unit that sets a state between a monitoring mode and an adjustment mode; and the light transmitting unit includes a mode switch that switches between a monitoring mode and an adjustment mode. When detecting an operation of a changeover switch, a mode switching signal is output to the synchronization line, and the light receiving unit receives the mode switching signal from the synchronization line to monitor or adjust the monitoring mode of the mode setting means. Mode to the other Photoelectric separated sensor, characterized in that changing Ri. 8. The photoelectric separation type sensor according to claim 7, wherein the mode switching signal is a pulse signal. 9. The photoelectric separation device according to claim 7, wherein the light receiving section has a mode selection switch for selecting a state between the monitoring mode and the adjustment mode, and sets the state in the mode setting means based on the switch. Type detector. 10. The photoelectric separation type sensor according to claim 7, wherein the light receiving section has an indicator light for indicating that the mode setting means is in the adjustment mode. 11. The light receiving section outputs a synchronization signal to a synchronization line at a predetermined cycle, and the light transmission section outputs a mode switching signal at a predetermined timing based on the synchronization signal. 11. The photoelectric separation type sensor according to any one of items 10. 12. A light transmitting unit and a light receiving unit provided opposite to the light transmitting unit with a smoke detection space interposed therebetween, for synchronizing light emission of the light transmitting unit and light reception of the light receiving unit. Synchronous line is connected, in a photoelectric separation type sensor that outputs fire information based on the amount of light received by the light receiving unit with respect to light emission of the light transmitting unit changes due to the presence of smoke, the light receiving unit includes: A power line and a signal line from a receiving unit are connected, and power is supplied to the light transmitting unit via the synchronization line.
The light transmitting unit has a standby power supply terminal connected to the synchronization line, and the light receiving unit has a path connected to a power supply line for supplying power from the synchronization line. Separate type sensor. 13. The method according to claim 1, wherein a backflow preventing means is provided on the path.
3. The photoelectric separation type sensor according to 2. 14. A light receiving section comprising: a power supply terminal; a constant voltage circuit for adjusting power from the power supply terminal to a predetermined voltage and outputting the adjusted voltage; and an output of the constant voltage circuit via a first backflow prevention element. An output terminal for outputting to a synchronous line, wherein a path is provided between the first backflow prevention element and the output terminal via a second backflow prevention element, the power supply terminal and the constant voltage circuit, 13. The photoelectric separation type sensor according to claim 12, which is connected between the sensors. 15. A light transmitting unit, and a light receiving unit provided opposite to the light transmitting unit with a smoke detection space interposed therebetween, for synchronizing light emission of the light transmitting unit and light reception of the light receiving unit. A synchronous line connected to the photoelectric separation type sensor that outputs fire information based on a change in the amount of light received by the light receiving unit with respect to the light emitted by the light transmitting unit due to the presence of smoke. Mode setting means for setting the state of, and timer means for starting when the adjustment mode is set and resetting when returning to the monitoring mode and outputting a timer when a predetermined time has elapsed, The photoelectric separation type sensor, wherein the mode setting means is switched to the monitoring mode based on a timer output from the timer means. 16. The light-receiving section has mode setting means, and the light-transmitting section has a mode changeover switch for outputting a mode changeover signal via a synchronizing line. 16. The photoelectric separation type sensor according to claim 15, wherein the mode switching signal is received to switch the monitoring mode or the adjustment mode of the mode setting means to the other mode. 17. The light receiving unit has a mode selection switch for selecting a state between a monitoring mode and an adjustment mode, and sets the state in the mode setting means based on the switch.
7. The photoelectric separation type sensor according to 6. 18. The sensor according to claim 16, wherein the mode switching signal is a pulse signal. 19. A light transmitting unit, and a light receiving unit provided opposite to the light transmitting unit with a smoke detection space interposed therebetween, for synchronizing light emission of the light transmitting unit and light reception of the light receiving unit. The synchronous line is connected, the photoelectric separation type sensor that outputs fire information based on the amount of light received by the light receiving unit with respect to light emission of the light transmitting unit changes due to the presence of smoke, wherein the light transmitting unit is A microprocessor that detects a synchronization signal from the light receiving unit via the synchronization line and performs light emission control of the light transmitting unit. A photoelectric separation type sensor wherein a stop mode is set at a timing after necessary processing including control is completed, and a start is made to a run mode before detecting the synchronization signal via the synchronization line. 20. A light receiving unit outputs a start signal before outputting a synchronization signal via a synchronization line, and a microprocessor of the light transmitting unit detects and activates the start signal via the synchronization line. The photoelectric separation type sensor according to claim 19. 21. The photoelectric separation type sensor according to claim 20, wherein the light receiving section has a timing sufficient for the microprocessor of the light transmitting section to be activated in an interval between the synchronization signal and the activation signal. 22. The photoelectric separation type sensor according to claim 19, wherein the microprocessor of the light receiving section enters a stop mode when necessary processing including light emission control ends. 23. The microprocessor of the light receiving section measures a processing time in which all necessary processing including light emission control can be performed with reference to a synchronization signal reception, and enters a stop mode.
22. The photoelectric separation type sensor according to any one of 9 to 21. 24. The light-receiving unit according to claim 19, wherein the light-receiving unit temporarily suspends power supply via a synchronous line to the light-transmitting unit after a lapse of a predetermined time after transmission of the received light amount information to the light-transmitting unit. The photoelectric separation type sensor according to any one of the above.