JPH0816949A - Photoelectric separation type smoke sensor - Google Patents

Abstract

PURPOSE:To improve the operability of a photoelectric separation type smoke sensor in its adjustment mode by blinking a monitor pilot lamp by the open detection signal received from a cover open/close detection means an also turning off the pilot lamp by the close detection signal. CONSTITUTION:The front cover of a photodetector 1 is opened and closed for adjustment of an optical axis and also setting the sensitivity. A cover open/ close detection switch 36 contained in the photodetector 1 consists of a limit switch. Then the switch 36 outputs an open detection signal and a close detection signal to a control part 50 when it detects the cover open and close states respectively. A monitor display control part 82 blinks the LED 38A-38F serving as the monitor display means when the open detection signal received from the switch 36 is discriminated at true part so. Meanwhile true part 82 turns off the LED 38A-38F when the close detection signal is discriminated. Thus it is not required to operate a monitor display means in each adjustment mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoelectric type smoke detector in which a light transmitter and a light receiver for smoke detection are separated, and more particularly, a photoelectric type smoke sensor which displays a monitor indicator light when a cover is opened. Regarding vessels.

[0002]

2. Description of the Related Art As a conventional photoelectric separation type smoke detector,
For example, for the adjustment of the optical axis and the adjustment of the amount of received light, there is a device in which a measuring device such as a tester is connected to the light receiver and the amount of light is adjusted while observing the amount of received light. However, with this smoke detector, it is difficult to make adjustments because the measuring device is connected to the detector body that is usually mounted at a high place and adjustment is performed while looking at the measuring device, which is dangerous. In addition, there is a problem that the work cannot be performed at all if the measuring instrument is forgotten.

In order to solve such a problem, there is a sensor equipped with a display lamp for displaying the amount of received light.
In this photoelectric separation type smoke sensor, as shown in FIGS.
When adjusting the light receiver, first, the cover 83 is removed, and the changeover switch 85 provided on the side surface of the main body 89, which is provided with the optical axis, the light amount, and the monitoring position, is moved to the “optical axis” position. Then, the adjusting screw 88 is turned to adjust the optical axis. Next, set the distance setting switch 84 according to the monitoring distance,
After the changeover switch 85 is set to the “light amount” position, the light amount adjusting knob 87 is turned.

Three lamps 86 for indicating the amount of received light are provided to indicate whether the amount of received light is insufficient, proper or excessive. Turn the light intensity adjustment knob 87 and adjust so that the appropriate lamp blinks. When the insufficient lamp flashes, the light amount adjustment knob 87 is turned to the increase side, and when the excessive lamp flashes, the light amount adjustment knob 87 is turned to the decrease side. When the adjustment of the optical axis and the amount of received light is completed, the changeover switch 85 is set to the "monitoring" position, the battery is removed, and the cover is attached.

[0005]

However, in such a conventional photoelectric separation type smoke sensor, when the light receiving amount display lamp which is the monitor display light is turned on, the changeover switch is set to the "light amount" position. It is done by switching the optical axis,
When the receiver is adjusted, the light is turned off by switching the selector switch to the "monitor" position, so it cannot be turned on or off unless the selector switch is adjusted to the specified position. However, there is a problem that it is complicated and the operability is poor.

The present invention has been made in view of the above-mentioned conventional problems. The present invention blinks the monitor indicator light by an open detection signal from the cover opening / closing detection means, and at the same time, makes a monitor detection lamp by the close detection signal. The purpose of this is to improve the operability during adjustment by turning off.

[0007]

FIG. 1 is a diagram illustrating the principle of the present invention. The present invention relates to a light transmitter 42 having a light emitting element 53.
In order to adjust the optical axis and to set the sensitivity of the photodetector 1 in which the photodetector 1 having the light receiving element 54 and the light receiving element 54 are separately arranged and the attenuation of light between them is detected. Monitor display control means 82 for displaying the monitor display means 38A to 38F by the open detection signal from the cover open / close detection means 36 for detecting the opening / closing of the front cover to be opened / closed and for not displaying the monitor display means 38A-38F by the close detection signal. Is provided.

[0008]

According to the photoelectric separated smoke detector of the present invention having such a structure, the cover opening / closing detecting means for detecting the opening / closing of the front cover which is opened / closed for adjusting the optical axis and setting the sensitivity. Monitor display means 3 according to the open detection signal from 36
8A to 38F are displayed and the monitor display means 38A to 38F are not displayed due to the closing detection signal.
The operation of displaying ~ 38F becomes unnecessary.

That is, as in the prior art, the monitor display means 38A to 38F are turned on by switching the changeover switch to the "light amount" position, and when the adjustment is completed, the changeover switch is changed to the "monitoring" position. Since the light is turned off by switching, it is possible to improve the operability by eliminating the trouble that the light cannot be turned on and off unless the changeover switch is set to a predetermined position.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 2 to 6 are views showing an embodiment of the present invention.
FIG. 2 is an exploded perspective view of a photodetector of a photoelectric separation type smoke sensor according to an embodiment of the present invention. The light transmitter is a light emitting element,
It has the same configuration except some of its related circuits and components.

In FIG. 2, the photodetector 1 of the photoelectric type smoke detector is separated from the light transmitter and is disposed on the side wall near the ceiling so as to face the phototransmitter, and the casing is composed of a vertically long cover 2 and a main body 3. ing. The cover 2 is provided with a member that transmits near-infrared light but blocks visible light, for example, a window 2A made of polycarbonate. Further, the cover 2 is configured to be vertically openable and closable with respect to the main body 3 by the cover fixing wire 4, the fixing metal fitting 5, and the cover fixing metal 6, and inside the main body 3, the lens holder 7 of the lens holder 7 is shown as exploded. The optical axis and received light amount adjustment mechanism is stored. The mounting plate 8 is screwed to the side wall near the ceiling so that the main body 3 is locked to the locking piece 8A of the mounting plate 8.

Next, the mechanism housed in the main body 3 will be described in detail. First, the base 9 of the optical axis / light receiving amount adjusting mechanism is formed of a metal fitting having an L-shaped side cross section.
Fixed horizontally. Below the base 9, a shield case 10, a printed board 11 on which circuit components for receiving light are mounted, a power supply board 12, and an insulating sheet 1 for the light receiving board.
3 is housed in a transparent circuit cover 14.

The base 9 has a fitting hole 9A into which an adjusting screw 20A for adjusting the horizontal direction of the lens holder 7 is fitted in the optical axis direction, the lens holder 7 and its supporting member 15.
A shaft hole 9B for horizontally rotatably supporting the lens holder 7 and a locking hole 9C for locking one end of the coil spring 16 for preventing the rattling of the lens holder 7 in the horizontal direction are formed.

A separator 17 is provided in the shaft hole 9B of the base 9.
Is attached by a mounting screw 18, and the separator 1
The reference numeral 7 is configured to fit vertically into the flange portions 9D and 9E of the base 9 so as not to rotate in the horizontal direction. The separator 17 is formed with a hole 17A through which one end of the coil spring 16 penetrates, a recess 17B for accommodating the body of the coil spring 16 and a shaft hole 17C.

The lens holder 7 is supported rotatably in a vertical direction with respect to a support member 15 having a U-shaped front cross section.
The support member 15 has the above-described mounting screw 18 as an axis,
The shaft hole 9 of the base 9 is inserted through the shaft hole 17C of the separator 17.
It is attached so as to be horizontally rotatable with respect to B. First, the horizontal rotation mechanism will be described. The support member 15 has a receiving screw 1 at a position deviated from the shaft hole 15A.
A locking hole 15B for locking 9A in the vertical direction is formed, and a screw thread is formed in this receiving screw 19A so that the above-mentioned horizontal adjusting screw 20A can be screwed in the optical axis direction. There is. Therefore, when the adjusting screw 20A is rotated, the support member 15 is horizontally rotated about the mounting screw 18.

A locking hole 15C for vertically locking the other end of the coil spring 16 in the support member 15 and an adjusting screw 20B for adjusting the vertical direction of the lens holder 7 are fitted in the optical axis direction. A fitting hole 15D is formed, and the lens holder 7 is supported by the support member 15 so as to be vertically rotatable about the screws 21 and 22. A coil spring 23 for preventing vertical play of the lens holder 7 is attached to the lens holder 7,
One end of this coil spring 23 is the locking hole 1 of the support member 15.
5E and the other end is locked to the locking piece 7A of the lens holder 7.

A receiving screw 19B is laterally attached to the side surface of the lens holder 7 at a position deviated from the rotation axis thereof, and the receiving screw 19B has a receiving screw 19A.
Similarly, the thread is formed so that the above-mentioned vertical adjusting screw 20B is screwed in the optical axis direction. Therefore, when the adjusting screw 20B rotates, the lens holder 7 rotates in the direction perpendicular to the support member 15.

The lens holder 7 is provided with an aiming hole 7B at the front upper right for looking diagonally from the front, and an aiming hole 7C is provided at the upper left front so as to be parallel to the optical axis direction. A reflection mirror 7D for obliquely reflecting the field of view seen through the hole 7C so that it can be seen through the sighting hole 7B is attached. 7E is a lens held by the lens holder 7.

A light receiving substrate 24 and a light receiving shield case 25 are fixed to the back side of the lens holder 7 with screws 26 and 27. On both sides of the lens holder 7, light-receiving amount adjustment knobs 2
8 and 29 are attached, and the light receiving amount adjusting knobs 28 and 29 are attached.
Adjusts the amount of received light by changing the photoelectric conversion voltage of the photoelectric conversion circuit. The received light amount adjustment knob 28 performs a rough adjustment, and the received light amount adjustment knob 29 performs a fine adjustment.

Next, FIG. 3 is a front view of the light receiver 1 with the cover 2 removed. In FIG. 3, 30 is the adjusting screw 20.
A is an optical axis adjusting knob, 31 is an optical axis adjusting knob of the adjusting screw 20B, and the optical axis adjusting knobs 30 and 31 have the adjusting screws 20A and 20B both attached in the optical axis direction. When the cover 2 is removed, it can be easily operated at a high place.

When the optical axis adjusting knob 30 of the horizontal adjusting screw 20A rotates counterclockwise, the lens holder 7 rotates leftward, and when the optical axis adjusting knob 30 rotates clockwise, the lens moves. The holder 7 rotates rightward. Also,
When the optical axis adjusting knob 31 of the vertical adjusting screw 20B rotates counterclockwise, the lens holder 7 rotates downward, and when the optical axis adjusting knob 31 rotates clockwise, the lens holder 7 rotates. Rotates upward.

The lens 7E is housed in the lens holder 7, and the lens holder 7 has the support member 1 as described above.
5 is rotatably supported in the vertical direction, and a support member 15
Is supported by the base 9 so as to be horizontally rotatable. A terminal nameplate 32 is attached to the front side of the circuit cover 14 below the separator 17 fixed to the base 9. The printed circuit board 11 is provided with an optical axis confirmation lamp 33 for confirming the optical axis. The optical axis confirmation lamp 33 is made of a red LED and blinks when the optical axis is adjusted to make it easy to see from the other side.

Further, the optical axis confirmation lamp 33 of the printed circuit board 11
Fire indicator light 3 consisting of LEDs on the left side of the
4 is provided, and on the right side of the optical axis confirmation lamp 33, there is provided a failure indicator lamp 35 including an LED that indicates a failure.
This optical axis confirmation lamp 33, fire indicator lamp 34, obstacle indicator lamp 35
Light emitted from the transparent circuit cover 14 and the terminal nameplate 32
It is output to the outside through the holes drilled in the corresponding places.

Further, a cover opening / closing detection switch 36 as a cover opening / closing detecting means for detecting opening / closing of the cover 2 is provided on the lower surface of the circuit cover 14, and the cover opening / closing detection switch 36 is as shown in FIG. Consists of limit switches. When the cover 2 is opened, the cover opening / closing detection switch 36 is turned off, and when the cover 2 is closed, the cover opening / closing detection switch 36 is turned on.

A distance selection switch 37 is provided on the lower surface of the circuit cover 14, and the sensitivity can be set to the specified sensitivity by setting it according to the monitoring distance. The distance selection switch 37 is a dip switch, and can be set to, for example, 5 m or more and less than 45 m, 45 m or more and less than 100 m, etc. by setting the switch. The position where nothing is set is the position for adjustment.

On the lower surface of the printed circuit board 11, six chip LEDs 38A to 38F as monitor display means are provided.
Are arranged along the left-right direction. Ie LED
38A to 38F are mounted on the printed circuit board 11 so as to face diagonally when viewed from the front. When looking into the other party through the collimation hole when adjusting the optical axis, LE from the viewing direction
D38A to 38F are mounted diagonally to make it easier to see the light emission.

These LEDs 38A to 38F are, in order from the left, two yellow LEDs 38A and 38B, two green LEDs 38C and 38D, and two red LEDs 38.
The LEDs 38A to 38F, which are composed of E and 38F and are located at positions corresponding to the light receiving level, are controlled to blink.
Therefore, the LEDs 38A to 38F constitute a light receiving level meter, and the photoelectric conversion voltage of the photoelectric conversion circuit is adjusted so that the green LEDs 38C and 38D display appropriate values when blinking.

That is, while checking the LEDs 38A to 38F, the light receiving amount adjusting knobs 28 and 29 are turned so that one of the two green LEDs 38C and 38D blinks. Thus, the vicinity of the center of the appropriate value of the amount of received light is obtained and the range of the amount of received light is known. In addition, 39 is an insertion terminal part. Next, FIG. 5 is a block diagram of a light receiver and a light transmitter.

In FIG. 5, reference numeral 1 denotes the light receiver, and the light receiver 1 is connected to a light transmitter 42 via light transmitter control lines 40 and 41. In addition, the light receiver 1 includes a fire signal line 43,
It is connected to the receiver 46 via the common line 44 and the fault signal line 45. Reference numeral 47 denotes a constant voltage / current limiting circuit provided in the light receiver 1. The constant voltage / current limiting circuit 47 is supplied with power from the receiver 46, generates a constant voltage, and limits the power source to generate a constant voltage. Is supplied to each part.

Reference numeral 48 denotes a light emission control circuit for controlling the light emission operation of the light transmitter 42. The light emission control circuit 48 receives a constant voltage from the constant voltage / current limiting circuit 47 via the diode 49, and the control section 50 controls. In response to the instruction, a light emission control signal is sent to the light transmitter 42 via the light transmitter control line 41. 5
Reference numeral 1 denotes a light emission control detection circuit provided in the light transmitter 42, and the light emission control detection circuit 51 detects a light emission control signal from the light receiver 1 to operate the light emission drive circuit 52. That is,
The light-emission control detection circuit 51 detects power-off at a constant interval which becomes a light-emission control signal from the light-emission control circuit 48, and operates the light-emission drive circuit 52 with negative logic.

Therefore, the light emitting element 53 composed of an LED
Is driven by the light emission drive circuit 52 and emits near-infrared light in a pulsed manner to the light receiving element 54 of the light receiver 1 through the lens. Reference numeral 55 denotes an optical axis confirmation lamp drive circuit provided in the light transmitter 42. The optical axis confirmation lamp drive circuit 55 detects a light emission control signal from the light emission control detection circuit 51 and the opening / closing of the cover of the light transmitter 42. It operates in response to an open detection signal (OFF signal) from the cover opening / closing detection switch 70 to drive the optical axis confirmation lamp 56 composed of an LED to blink it.

Reference numeral 37 denotes the distance selection switch provided in the light receiver 1. The distance selection switch 37 sends a signal indicating a specified sensitivity set according to the monitoring distance to the sensitivity input circuit 57.
To the control unit 50 via. The control unit 50 calculates a threshold value (fire determination level) based on an initial value which is a light receiving output after closing the cover 2 and the sensitivity setting after closing the cover 2, and stores it in the RAM 81 as a reference signal. To do.
The control unit 50 compares this reference signal with the received light signal, and when the received light signal is smaller than the reference signal, it judges that there is a fire and outputs a fire signal to the fire signal output circuit 71.

Reference numeral 36 denotes the cover open / close detection switch provided in the light receiver 1, and the cover open / close detection switch 36
Detects an opening of the cover 2, an open detection signal (OFF signal)
When the closing of the cover 2 is detected, a closing detection signal (ON signal) is output to the control unit 50 via the cover opening / closing input circuit 58 and also to the oscillation circuit 59. The oscillating circuit 59 receives the open signal from the cover open / close detection switch 36 and the constant voltage from the constant voltage / current limiting circuit 47 to generate a voltage of 5V.
The oscillation operation is performed based on the voltage of V, and the oscillation output is given to the optical axis confirmation lamp control circuit 61. The optical axis confirmation lamp control circuit 61 includes an oscillation output from the oscillation circuit 59 and a cover opening / closing input circuit 58.
The optical axis confirmation lamp 33 blinks on the basis of the open signal from.

At the time of monitoring, if the control unit 50 detects a fire (for example, a dimming rate of 70% or more continues for a predetermined time),
The fire signal is sent to the receiver 46 by outputting to the fire signal output circuit 71. In this state, even if a failure due to interruption is detected (for example, a dimming rate of 90% or more continues for a predetermined time or longer), the control unit 50 detects a fire and does not output a failure signal. .

The fault signal output cutoff circuit 62 cuts the fault signal from the control unit 50 by the output from the fire signal output circuit 71. Basically, the control unit 50
It is not necessary because the obstacle signal is not output, but it is provided in order to prevent the obstacle signal from being output to the receiver 46 even if it is erroneously output. The control unit 50 detects a failure due to interruption (for example, dimming rate 90
% Continues for a predetermined time or longer), the fault signal output circuit 63 outputs the fault signal to the receiver 46.

When a failure due to interruption is detected, or when it is detected that normal monitoring cannot be performed, a failure signal is output from the control unit 50, and the failure indicator lamp 35 blinks the occurrence of failure by this failure signal. Then, the fault signal output circuit 63 sends a fault signal to the receiver 46 via the fault signal line 45. On the other hand, when the fire signal output circuit 71 detects a fire signal from the control unit 50, the fire signal output circuit 71 turns on the fire indicating lamp 34 via the diode 64 and sends a fire signal to the receiver 46 via the fire signal line 43. .

Reference numeral 54 denotes the light receiving element formed of a photodiode provided in the light receiving device 1, and the light receiving element 54 receives near infrared light pulsed from the light emitting element 53 of the light transmitter 42. The light receiving element 54 and the variable resistor 72 form a photoelectric conversion circuit 65. The received light signal is the photoelectric conversion circuit 6
The signal is converted into an electric signal by 5 and is amplified by the amplifier circuit 66. By rotating the light receiving amount adjusting knobs 28 and 29, the resistance value of the variable resistor 72 is changed to change the photoelectric conversion voltage and increase or decrease the light receiving amount.

The analog electric signal amplified by the amplifier circuit 66 is held by the peak hold circuit 73 and then enters the control section 50 through the light receiving amount input circuit 74. The control unit 50 is I
It is composed of C and has an A / D converter 68 built therein.
The analog electric signal is converted into a digital value by the A / D converter 68. The control unit 50 is provided with a drive table 69 for driving the LEDs 38A to 38F as the monitor display means, and the control unit 50 refers to the contents of the drive table 69 to drive the LEDs 38A to 38F, respectively.

Further, the control section 50 is provided with a sensitivity setting state judging section 75 as a sensitivity setting state judging means, and the sensitivity setting state judging section 75 is provided with the distance selection switch 37 for setting the sensitivity according to the monitoring distance. The setting status of the DIP switch is determined. Further, the control unit 50 is provided with a cover open / closed state determination unit 76 as a cover open / closed state determination unit for determining the cover open / closed state depending on whether the cover open / close detection switch 36 for detecting the open / close state of the cover 2 is turned on or off. The discriminator 76 is configured to detect the cover opening / closing detection switch 36.
Is off, it is determined that the cover 2 is in the open state, and when the cover open / close detection switch 36 is on, it is determined that the cover 2 is in the closed state.

Reference numeral 77 is a fault signal output unit provided as a fault signal output means provided in the control unit 50. The fault signal output unit 77 outputs a fault signal when any of the following states is detected. (1) When it is detected that the cover 2 is closed without setting the sensitivity setting (when the sensitivity setting is forgotten). (2) When it is detected that the cover 2 has been opened for a predetermined time T1 (for example, 5 minutes) with the sensitivity setting set (if the sensitivity setting is made but the cover is forgotten to be closed, something will happen later). If the cover comes off due to a shock, such as when the ball hits). (3) When it is detected that the cover 2 has been opened for a predetermined time T2 (for example, 2 hours) or more in a state where the sensitivity is not set (the optical axis is adjusted but the sensitivity is set and the cover 2 is closed). If you just connect the power supply and did nothing later).

The fault signal is output to the fault signal output circuit 63 through the fault signal output cutoff circuit 62, transmitted from the fault signal output circuit 63 to the receiver 46, and the fault indicator lamp 35 blinks. An initial value registration unit 78 as an initial value registration unit is provided in the control unit 50, and the initial value registration unit 78 indicates that the sensitivity is set by the distance selection switch 37 by the sensitivity setting state determination unit 75. When it is determined that the cover open / closed state determination unit 76 determines the open / closed state of the cover 2 by the cover open / closed detection switch 36, if the initial value is not registered, the light reception output at that time is registered as the initial value.

That is, the initial value registration unit 78 registers the light reception output at that time as the initial value when the initial value is not registered in the RAM 81 at the time of installation, power recovery after a power failure, etc. The registration of this initial value is performed by storing the received light output a plurality of times, for example, five times (light emission and light reception are performed once every three seconds),
This is performed by calculating the average value and setting the average value as the initial value. This is because if one light reception output is set as the initial value, an incorrect light reception output (effect of noise or the like) is registered as the initial value.

When the averaged initial value is out of a certain set range, a fault signal is output and the initial value is registered again.
Further, the control unit 50 is provided with a fire judgment level calculation unit 79 as a fire judgment level calculation unit, and the fire judgment level calculation unit 79 is provided with the registered initial value and distance selection switch 37.
The threshold (fire judgment level) is calculated from the sensitivity set in.

Further, the control unit 50 is provided with a fire monitoring unit 80 as a fire monitoring means, and when the initial value has already been registered, the fire monitoring unit 80 monitors the fire at the already calculated fire judgment level. I do. Here, the control unit 5
0 is provided with a monitor display control unit 82 as a monitor display control unit, and the monitor display control unit 82 causes the cover open / closed state determination unit 76 to output an open detection signal from a cover open / closed detection switch 36 as a cover open / closed detection unit. When the determination is made, the LEDs 38A to 38F as the monitor display means blink, and when the cover open / closed state determination unit 76 determines the close detection signal from the cover open / closed detection switch 36, the LED 3
Turn off 8A to 38F.

The monitor display control unit 82 does not require the operation of displaying the LEDs 38A to 38F during adjustment. Next, the operation will be described. FIG. 6 is a flowchart explaining the operation. In FIG. 6, first, step S1
To import the data. That is, the received light amount is received by the light receiving element 54 and is received through the photoelectric conversion circuit 65, the amplification circuit 66, the peak hold circuit 73, and the received light amount input circuit 74, and is detected by the cover opening / closing detection switch 36. The off signal (open detection signal) and the on signal (close detection signal) input via the cover opening / closing input circuit 58 are taken in, and the distance selection switch 37 detects the signal and the dip switch input via the sensitivity input circuit 57. Takes in setting signals (sensitivity setting signal, sensitivity non-setting signal).

Next, in step S2, the distance selection switch 3
It is determined whether or not 7 is in the sensitivity setting state. That is,
The sensitivity setting state determination unit 75 determines whether or not the sensitivity is set. If the sensitivity has not been set, the operation proceeds to step S3, and if the sensitivity has been set, the operation proceeds to step S8.
Go to. In step S3, the cover open / close detection switch 36
Determine if is on. That is, the cover 2
If the cover 2 is closed, the cover open / closed state determiner 76 determines whether the cover 2 is open.
Go to 4.

That is, when it is detected that the cover 2 is closed with the sensitivity setting not set,
Immediately after determining that the sensitivity setting has been forgotten, a fault signal is output in step S4. The failure signal output by the failure signal output unit 77 is transmitted to the receiver 46 and causes the failure indicator lamp 35 to blink. This informs the person in charge of the adjustment that the sensitivity setting has been forgotten.

When the cover 2 is opened in step S3, it is determined in step S5 whether or not a predetermined time T2, for example, 2 hours has elapsed. If so, step S6
To output a fault signal. That is, when it is detected that the cover 2 is open for 2 hours or more without the sensitivity being set, the optical axis is adjusted but the sensitivity setting and the cover 2 are forgotten to be closed, or only the power supply is connected. After that, it is determined that nothing has been done, the fault signal output unit 77 outputs a fault signal to the receiver 46, and causes the fault indicator lamp 35 to blink. This fault signal notifies the person in charge of the occurrence of the above fault.

Next, in the state where the sensitivity is set, it is determined in step S8 whether or not the cover open / close detection switch 36 is off. If the cover 2 is open, step S9 is performed.
Then, it is determined whether or not a predetermined time T1, for example, 5 minutes has elapsed, and when 5 minutes have elapsed, a fault signal is output in step S10. That is, when it is detected that the cover 2 has been opened for 5 minutes or more with the sensitivity setting set, the sensitivity setting is performed but the cover 2 is forgotten to be closed, or some shock such as a ball hits later. When the cover 2 is removed due to a problem, the fault signal output unit 77
Outputs a trouble signal to the receiver 46 and causes the trouble indicator lamp 15 to blink. As a result, the person in charge is informed that the above-mentioned failure has occurred. The predetermined time T1 sets the time taken from the sensitivity setting to the closing of the cover 2.

Here, the sensitivity is not set by the distance selection switch 37 in step S2, the cover open / close detection switch 36 is turned off in step S3, and the adjustment mode of step S7 is entered when two hours have not elapsed in step S5. Time,
Alternatively, when the distance selection switch 37 is in the sensitivity setting state in step S2, the cover open / close detection switch 36 is off in step S8, and 5 minutes have not elapsed in step S9, that is, when the open detection signal from the cover open / close detection switch 36 is determined. Causes the monitor display control unit 82 to blink the LEDs 38A to 38F which are monitor display means.

When the cover opening / closing detection switch 36 is turned on in step S8, that is, when the closing detection signal from the cover opening / closing detection switch 36 is determined, the LEDs 38A to 38F are turned off in step S17. In this way, the operation of displaying the LEDs 38A to 38F one by one at the time of adjustment becomes unnecessary. As a result, operability can be improved.

When the sensitivity setting is set and the cover 2 is closed, it is determined that the adjustment of the optical axis and the received light amount is completed, and the flag indicating the registration of the initial value is 0 (initial value) in step S11. If the initial value is not registered, the received light output at that time is registered as an initial value in step S12, and the initial value registered in step S13 and the distance selection switch 37 are determined. A threshold value (fire determination level) is calculated from the set sensitivity, and the flag is set to 1 in step S14 to register the threshold value. Step S1
If the initial value has already been registered at 1, fire monitoring will continue with the threshold value already calculated.

[0053]

As described above, according to the present invention, the monitor display means is displayed by the open detection signal from the cover opening / closing detection means, and the monitor display means is not displayed by the close detection signal. The operation of displaying the monitor display means one by one at the time of adjustment becomes unnecessary, and the operability can be improved.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an exploded perspective view of a light receiver showing an embodiment of the present invention.

FIG. 3 is a front view of the light receiver.

FIG. 4 is a side view of the light receiver.

FIG. 5 is a block diagram of a light receiver and a light transmitter.

FIG. 6 is a flowchart illustrating the operation.

FIG. 7 is a side view showing a conventional example.

FIG. 8 is a front view showing a conventional example.

[Explanation of symbols]

1: Light receiver 2: Cover 2A: Window 3: Main body 4: Cover fixing wire 5: Fixing metal 6: Cover fixing metal 7: Lens holder 7A: Locking piece 7B, 7C: Aiming hole 7D: Reflecting mirror 7E: Lens 8 : Mounting plate 8A: Locking piece 9: Base 9A: Fitting hole 9B: Shaft hole 9C: Locking hole 9D, 9E: Flange portion 10: Shield case 11: Printed circuit board 12: Power supply board 13: Insulation sheet for light receiving board 14: Circuit cover 15: Support member 15A: Shaft hole 15B, 15C, 15E: Locking hole 15D: Fitting hole 16, 23: Coil spring 17: Separator 17A: Hole 17B: Recess 17C: Shaft hole 18: Mounting screw 19A , 19B: Receiving screw 20A, 20B: Adjusting screw 21, 22, 26, 27: Screw 24: Light receiving substrate 25: Light receiving shield case 28, 29: Light receiving amount Adjusting knobs 30, 31: Optical axis adjusting knob 32: Terminal name plate 33, 56: Optical axis confirmation light 34: Fire indicator light 35: Fault indicator light 36, 70: Cover open / close detection switch (cover open / close detection means) 37: Distance selection Switches 38A to 38F: LEDs (monitor display means) 39: Plug-in terminals 40, 41: Transmitter control line 42: Transmitter 43: Fire signal line 44: Common line 45: Fault signal line 46: Receiver 47: Constant voltage current limiting circuit 48: Generation control circuit 49, 64: Diode 50: Control unit 51: Light emission control detection circuit 52: Light emission drive circuit 53: Light emission element 54: Light reception element 55: Optical axis confirmation lamp drive circuit 57: Sensitivity input Circuit 58: Cover open / close input circuit 59: Oscillation circuit 60: 5V constant voltage circuit 61: Optical axis confirmation lamp control circuit 62: Fault signal output cutoff circuit 63: Fault signal output Line 65: Photoelectric conversion circuit 66: Amplification circuit 68: A / D converter 69: Driving table 71: Fire signal output circuit 72: Variable resistance 73: Peak hold circuit 74: Light reception amount input circuit 75: Sensitivity setting state determination unit 76 : Cover open / closed state determination unit 77: Fault signal output unit 78: Initial value registration unit 79: Fire determination level calculation unit 80: Fire monitoring unit 81: RAM 82: Monitor display control unit (monitor display control means)

Claims (1)

[Claims] 1. A photoelectric-separated smoke sensor, wherein a light-transmitting device having a light-emitting element and a light-receiving device having a light-receiving element are separately arranged and light attenuation between them is detected, wherein the light-receiving device has an optical axis or the like. Monitor display control for displaying the monitor display means by the open detection signal from the cover open / close detection means for detecting the opening / closing of the front cover that is opened / closed for adjustment and sensitivity setting, and not displaying the monitor display means by the close detection signal A photoelectric separated smoke detector, characterized in that means are provided.