JP2944169B2 - Hot wire type human body detector - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-wire type human body detector which detects a hot-wire emitted from a human body and issues an alarm.

[Related Art] Conventionally, in a hot-wire type human body detector, in order to prevent false reports due to popcorn noise or the like, sensor outputs are counted, and an alarm is output when a predetermined count is reached.
That is, after amplifying the output from the sensor unit, a pulse indicating a signal portion exceeding a threshold is generated by a comparison circuit, and the output pulse of the comparison circuit is counted by, for example, a counter. Alternatively, an alarm output is generated when three counts are reached. After reaching a predetermined count value and generating an alarm output, the counter is reset and returned to the initial state, thereby creating a countable state for the sensor output obtained next.

[Problems to be Solved by the Invention] However, in the case of such a conventional counter type, for example, a three-count type hot-wire type human body detector, in a check after the detector is installed, a person actually walks in a warning area to be alert. When checking the zone, a warning is issued every three counts that cross the three warning zones, so it is not possible to check the actually set warning zone, and the walking distance before the warning is issued becomes longer, so check There is a problem that it is difficult for a person to confirm whether or not the security area is actually set. This problem is exacerbated as the guard distance increases. In other words, when the guard distance is long, the beam interval is inevitably widened, the walking distance is long before the warning is obtained, and it is extremely confirmed whether the beam warning zone is set at the scheduled position. It becomes difficult.

The present invention has been made in view of such a conventional problem, and even if a counting method that does not warn unless the vehicle crosses a plurality of zones is adopted, a warning area can be checked at the time of inspection, particularly, a warning of a long distance. It is an object of the present invention to provide a hot-wire type human body detector capable of easily confirming a warning zone set in an area.

[Means for Solving the Problems] To achieve this object, a hot-wire type human body detector according to the present invention is configured as follows. The reference numerals in the drawings of the embodiments are also shown.

First, the present invention provides a sensor unit 10 for detecting heat rays emitted from a human body when the human body passes through a plurality of alert zones.
And a comparison circuit 16 that generates an output when the output of the sensor unit 10 exceeds a threshold value that is set to two or more predetermined values, and outputs the output from the comparison circuit 16 every time a human body passes through a plurality of alert zones. A counting circuit 18 that counts and generates a count output when the count value reaches a predetermined value within a predetermined time;
Alarm output circuit that sends an alarm signal based on the count output of
22 for a hot-wire type human body detector having a steady monitoring mode.

In the present invention, such a hot-wire type human body detector is provided with a changeover switch circuit 26 as an inspection means for switching the count value of the counting circuit 18 to an inspection mode including one or more counts.

[Action] According to the hot-wire type human body detector of the present invention having such a configuration, in the steady monitoring mode, an alarm output is generated when a set count value of the sensor output reaches 2 or 3 counts, and the alarm output is caused by popcorn noise or the like. Although false alarms are prevented, in the inspection mode, when the switch of the changeover switch circuit is switched, the set count value is switched to a set value smaller than the set count value. For example, an alarm output can be obtained for each count, and at the time of inspection, An alarm output is obtained every time the vehicle passes through the security zone set in the security area, and it is possible to easily check the security zone setting, particularly the security zone set in the security area at a long distance.

[Embodiment] Fig. 1 is an embodiment configuration diagram showing one embodiment of a hot-wire type human body detector of the present invention.

In FIG. 1, a sensor unit 10 includes an infrared detecting element known as a pyroelectric element for detecting a heat ray emitted from the human body. In this embodiment, a twin element using two detecting elements is used. To detect heat rays emitted from the human body. As shown in the plan view of FIG. 6 (a) and the side view of FIG. 6 (b), the alert zone for the alert area is set by the sensor unit 10 into a plurality of zones. These multiple alert zones are Fresnel lenses provided on the cover of the sensor unit 10,
Alternatively, it is set optically by a condenser mirror.

When the vehicle crosses one alert zone shown in FIG. 6, a detection signal shown in FIG. 2 is obtained from the sensor unit 10. FIG. 2 (a) shows a signal waveform when the vehicle crosses a short distance of the security zone, and FIG. 2 (b) shows a signal waveform when the vehicle crosses a long distance of the security zone. That is, from the sensor unit 10 using the twin element, an amplitude change of the opposite polarity occurs after the rise of the first signal waveform, and then an amplitude change of the same polarity as the first occurs. The amplitude of the detection signal of the sensor unit 10 is large at a short distance, but relatively decreases at a long distance.

After the detection signal from the sensor unit 10 is amplified by the amplifier circuit 12, it is supplied to the absolute value conversion circuit 14. Absolute value conversion circuit 14
Converts the signal waveform of the detection signal from the sensor unit 10 shown in FIG. 2 so as to have the same polarity. For example, as shown in FIG. 2, a converted signal converted so that all amplitudes have a positive polarity is output.

The converted signal from the absolute value conversion circuit 14 is applied to a comparison circuit 16 and compared with a preset threshold value Vref to generate a comparison output, that is, a pulse output, which becomes H level for a signal portion exceeding the threshold value Vref. The comparison output of the comparison circuit 16 continuously produces two pulse outputs when the distance is short as shown in FIG. 2A, but one pulse output when the distance is long as shown in FIG. 2B. Will occur.

The comparison output of the comparison circuit 16 is applied to the counting circuit 18 and counted, and the count value is set to a predetermined value, for example, 2
A count output is generated when the count or three counts is reached. The set count value set in the counting circuit 18 can be switched and set to 2 counts or 3 counts by the setting circuit 20.

The counting output when the comparison output reaches the set count value in the counting circuit 18 is given to the alarm output circuit 22, the normally closed relay contact 24 is opened by the recovery operation of the built-in relay, and the signal line 28 from the receiver is connected. Release to send an alarm signal to the receiver. Note that power is supplied to each circuit section through power lines 30, 30 'from the receiver.

According to the present invention, such a hot-wire type human body detector is further provided with a changeover switch circuit 26 for switching the set count value of the counting circuit 18 to a smaller value at the time of inspection or the like. That is, when the inspection switch provided in the changeover switch circuit 26 is switched to the inspection side at the time of inspection, the counting circuit 18
Is switched to a smaller count value, for example, one count value.

FIG. 3 is a circuit block diagram showing one embodiment of the counting circuit 18 in the embodiment of FIG. In FIG. 3, the comparison output from the comparison circuit 16 is supplied to the set time timer 32 and also to the counter 34 at the same time. Set time timer
The counter 32 outputs a set signal to the counter 34 for a certain period of time after receiving the comparison output, and the counter 34 can count the comparison output while receiving the setting signal from the set time timer 32. A predetermined count value, for example, 2 counts or 3 counts, is set in advance for the counter 34, and during the period from when the comparison output is first received to when the set output during the set time of the set time timer 32 is obtained. When the count value of the comparison output reaches the set value, a count output is generated. The count output of the counter 34 is given to the one-shot timer 36, and the one-shot timer 36 is triggered by the counter output to give a one-shot pulse having a predetermined pulse width to the alarm output circuit 22 of the next stage. One-shot timer
When 36 ends the pulse output, a reset signal is output to the set time timer 32 to return to the initial state.

FIG. 4 is a circuit diagram showing a more specific embodiment of the counting circuit of FIG.

In FIG. 4, the counter 34 is composed of JK-FFs 34-1 and 34-2, performs a count operation of the set count 2 with the JK-FF 34-1, and is set by two of the JK-FFs 34-1 and 34-2. The counting operation of count 3 is performed. The switching between the set counts 2 and 3 is performed by the set count value switch 38. The set count 2 is set when the set count value switch 38 is turned on as shown in the figure, and the set count 3 is set when the set count value switch 38 is turned off. .

The set time timer 32 is connected to the capacitor C6 for the terminals T1 and T2.
A predetermined setting time is determined by a time constant due to the connection of the resistor R2 and the resistor R2, and is triggered by an output from the comparison circuit 16 to the terminal A, and Q is set to L level. The output of the set time timer 32 is connected to the capacitor C5 via the resistor R7.
C5 is charged by the = H level output via the resistor R7. Therefore, the output becomes L by the trigger of the set time timer 32.
When inverted to the level, the charging voltage of the capacitor C5 is discharged via the resistor R7, and the CL terminal and the P terminal of the JK-FFs 34-1, 34-2 are gradually pulled down to the L level, and set by the comparison output with respect to the clock terminal CP. It becomes possible.

The one-shot timer 36 has a one-shot operation time determined by a time constant obtained by connecting the capacitor C8 and the resistor R5 to the terminals T1 and T2, and constitutes a counter for the terminal A by JK.
-A one-shot pulse which is triggered by the Q output (H level output) of the FF 34-1 or 34-2 and becomes H level from the Q output is sent to the alarm output circuit 22. At the same time, L
The reset signal which becomes the level is supplied by the capacitor C7 and the resistors R3 and R4.
Is applied to the CD terminal of the set time timer 32 via a differentiating circuit, whereby the set time timer 32 is forcibly reset to return to the initial state. Furthermore, the Q of JK-FF34-1 and 34-2
Diodes D1 and D2 provided on the line from the output are provided to guarantee the detection operation by the set count 3 without failing even if a contact failure occurs in the set count value changeover switch 38.

In the present invention, a check switch 40 is connected to such a counting circuit so as to bypass the counter 34 shown in FIG. That is, in the circuit diagram of FIG. 4, the comparison output is directly supplied to the A terminal of the one-shot timer 36 via the check switch 26. When the check switch 26 is turned on as shown in FIG. , Namely JK-FF34
The one-shot timer 36 is directly triggered by the comparison output by canceling the counting function by -1, 34-2, and a one-shot pulse can be output to the alarm output circuit 22 for each comparison output.

Next, the operation of the counting circuit of FIG. 4 will be described with reference to the operation timing chart of FIG.

In the initial state, the setting count value changeover switch 38 is turned on as shown to set the setting count 2 and
The inspection switch 26 is in an off state.

In this state, when the first comparison output, that is, the pulse output of H level is obtained from the comparison circuit 16 based on the detection output of the sensor unit 10, the comparison output is input to the terminal A of the set time timer 32 to trigger. The output is set to L level. When the output is inverted to the L level, the electric charge charged in the capacitor C5 is discharged through the resistor R7, and JK-FF34-1, 34-
2 CL terminal and P terminal are gradually pulled from H level to L level. Therefore, during the first comparison output, JK-FF
Since the CL terminal and the P terminal of 34-1 are at the H level, the set operation, that is, the count operation is not performed even if the comparison output to the CP terminal is received. Thus, no count output is issued for the first comparison output.

Subsequently, when the second comparison output is input while the output of the set time timer 32 is at the L level, the CL terminal and the P terminal of the JK-FF34-1 have already finished discharging the capacitor C5. Since the level is at the L level, the JK-FF34-1 operates and performs a two-count operation in which the Q output is inverted from the L level to the H level. JK-FF based on this 2 count operation
The Q output of 34-1 is applied to the A terminal of the one-shot timer 36 via the diode D1 and the set count value changeover switch 38, and the one-shot is synchronized with the rise of the Q output of the JK-FF 34-1 to the H level. The timer 36 is triggered to generate a Q output that goes to the H level, and sends an alarm output to the alarm output circuit 22 at two counts. At the same time, the output of the one-shot timer 36 is inverted from H level to L level, and the CD terminal of the set time timer 32 is pulled down to L level by a differential pulse and reset to return to the initial state.

Of course, if the second comparison output is not obtained within the set time of the set time timer 32, the control is restored to the set time timer 32, the output is set to the H level, and the JK-FFs 34-1, 34-2 are reset.

On the other hand, when the set count value changeover switch 38 is turned off and the set count 3 is set, the second count JK-FF
When the third comparison output is obtained while the Q output of 34 is inverted to the H level, the JK-FF 34-2 is inverted to the H level of the Q output, and the one-shot timer 36 is similarly triggered to trigger the one-shot timer 36. The shot pulse is sent to the alarm output circuit 22.

Next, at the time of inspection, when the inspection switch 26 is turned on as shown in the figure, the comparison output from the comparison circuit 16 is directly applied to the A terminal of the one-shot timer 36 via the inspection switch 26. The timer 36 triggers each time a comparison output is obtained, sends a one-shot pulse to the alarm output circuit 22, and opens the relay contact 24 by the operation of the relay provided in the alarm output circuit (restoring operation) to release the relay contact 24. To send an alarm signal to the user.

In the above embodiment, the case where the setting count 2 or 3 can be set by switching is taken as an example. However, the setting count value may be fixedly set, or the setting count value of 4 or more may be set. It may be a value. In any case, by switching the inspection switch 26 to the inspection side, an alarm may be output with a count value smaller than the set count value.
In the above embodiment, the set count value is switched to 1 count by turning on the check switch 40.
If the count value is smaller than the set count value, the count value may be switched to an appropriate count value.

When the inspection switch 40 switches to a smaller value of the set count value during inspection and, for example, crosses a monitoring zone shown in FIGS. An alarm output is obtained, and it is possible to easily confirm that a preset alert zone is set in the alert area.

More specifically, in the conventional counting method, when a warning area is actually walked by a person to check the warning zone at the time of inspection, the checking becomes more difficult as the warning distance increases. That is, in the guard area of a short distance, which is relatively short, such as the guard distance of 5 m or less in FIGS. If an alarm output is obtained, it is relatively easy to check the alert zone for each beam set in the alert area. However, in the middle-range guard area where the guard distance is 5 to 10 m, the beam interval is widened, and the walking distance becomes longer by that time until the warning output is obtained, so check the guard zone for each beam set in the guard area Is difficult to do.

In addition, in a long-distance guard area where the guard distance exceeds 12 m, for example, in a long-distance guard area such as 20 to 30 m, the beam interval is considerably widened, the walking distance becomes longer before a guard output is obtained, and the warning zone for each beam in the guard area is confirmed. Is extremely difficult to perform.

On the other hand, in the present invention, the monitoring zone for each beam shown in FIGS. 6A and 6B is confirmed by switching to a value smaller than the counter value set by the inspection switch 40, for example, to one count. When a person actually walks in the security area, an alarm output is obtained every time the vehicle crosses the security zone corresponding to each beam.Especially, even in the long-distance security area where the security zone was extremely difficult to confirm, It can be easily confirmed that the zone is set.

[Effects of the Invention] As described above, according to the present invention, in order to prevent false alarm due to popcorn noise or the like, an alarm output is output when a sensor output reaches a predetermined set count value such as 2 counts or 3 counts. Even if it is performed, by performing a switching operation for switching the set count value to a smaller set value at the time of inspection, for example, an alarm output can be obtained at each count, and the vehicle passes through the alert zone set in the alert area at the time of inspection. Each time an alarm output is obtained, check the alert zone,
In particular, it is possible to easily confirm the alert zone set in the alert area at a long distance.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention; FIG. 2 is an explanatory diagram showing a sensor section detection signal, an absolute value conversion signal, and a comparison output of the present invention separately for a short distance and a long distance; FIG. 4 is a specific circuit diagram of the counting circuit of FIG. 3; FIG. 5 is an operation timing chart of FIG. 4; FIG. 6 is a warning area by the detector of the present invention. FIG. 4 is an explanatory diagram showing a setting state of a warning zone with respect to FIG. In the figure, 10: sensor unit 12: amplification circuit 14: absolute value conversion circuit 16: comparison circuit 18: counting circuit 20: setting circuit 22: alarm output circuit 24: relay contact (normally closed) 26: changeover switch circuit (inspection switch) 28: Signal line 30, 30 ': Power supply line 32: Set time timer 34: Counter 34-1, 34-2: JK-FF 36: One shot timer 38: Set count value changeover switch 40: Inspection switch

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tomoo Kido 2-10-43 Kami-Osaki, Shinagawa-ku, Tokyo Inside Hochiki Co., Ltd. (56) References JP-A-61-129536 (JP, A) JP-A-62 JP-A-197722 (JP, A) JP-A-60-45897 (JP, A) JP-A-62-293400 (JP, A)

Claims (1)

(57) [Claims] When a human body passes through a plurality of alert zones, a sensor unit for detecting a heat ray radiated from the human body every time the human body passes through any of the alert zones, and an output of the sensor unit A comparison circuit that generates an output when the count value exceeds a preset threshold value, a counting circuit that counts an output from the comparison circuit and generates a count output when the count value reaches a predetermined value within a predetermined time, And a warning output circuit for transmitting a warning signal based on the count output of the circuit, wherein the count value of the counter is changed from a steady monitoring mode consisting of two or more predetermined values to a count value of one. A hot-wire type human body detector provided with an inspection means for switching to an inspection mode comprising: