JPH0827870B2 - Infrared type intruder detector - Google Patents

Description

The present invention relates to an infrared type intruder detector having a self-diagnosis function.

[Prior Art] FIG. 2 shows a conventional infrared type intruder detector, wherein 1 is a condenser mirror whose mirror surface is a parabolic surface, and 2 is a light receiving element for receiving infrared rays. As the light-receiving element 2, for example, a pyroelectric detector utilizing the pyroelectric effect is used. When infrared light is received, a slight temperature rise induces electric charges by spontaneous polarization action, and the electric charges are taken out as voltage or current. Is.

The operation of the above conventional device will be described with reference to FIG. Humans generally emit infrared rays, and the maximum emission wavelength is about 9.6 μm. Further, infrared rays having a wavelength of 8 to 14 μm pass through the atmosphere well. Therefore, when there is an intruder as shown in FIG. 3A, the infrared ray 3 emitted by the intruder is condensed by the condenser mirror 1 and received by the light receiving element 2. Therefore, a detection circuit (not shown) including the light receiving element 2
Outputs an output as shown in FIG. 9B, and when this output exceeds the alarm level, an intruder alarm is generated with a predetermined holding time as shown in FIG.

In the above infrared type intruder detector, an infrared ray emitting section that emits infrared rays at almost the same level as the infrared ray from the intruder is installed near the light receiving section in order to detect an abnormality in the detector element or circuit, and The diagnostic timing is turned on. At this time, if the level of the light receiving signal from the light receiving unit does not reach the alarm level, it is determined that an abnormality has occurred in the detector element or circuit, and the detector abnormality signal is output.

[Problems to be Solved by the Invention] However, since the above-mentioned conventional infrared type intruder detector does not have a self-diagnosis function, even if an abnormality occurs in an element or a circuit, it is not immediately understood and it is manually There was no choice but to find an abnormality by conducting an inspection.

Further, even if the intruder has a self-diagnosis function, if an intruder is present during the self-diagnosis, an intruder alarm cannot be output and an intruder cannot be detected even if an output exceeding the alarm level is obtained.

The present invention has been made to solve the above-mentioned conventional problems, has a self-diagnosis function, can detect an abnormality of self at an early stage without relying on human hands, and also at the time of self-diagnosis. An object of the present invention is to obtain an infrared intruder detector capable of detecting an intruder and outputting an alarm by an intruder and an alarm due to a failure of the detector separately.

[Means for Solving Problems] An infrared intruder detector according to the present invention includes a self-diagnosis timing signal generator that outputs a self-diagnosis timing signal indicating a timing for performing self-diagnosis, and an input of the self-diagnosis timing signal. The infrared light emitting section that generates infrared rays for self-diagnosis by, the light receiving section that receives the infrared light generated by the intruder and the infrared light emitting section and outputs the light receiving signal according to the light receiving level of the infrared ray, the self-diagnosis timing signal and the light receiving signal When the signal is input and the self-diagnosis timing signal is not input, the received light signal is compared with the alarm level for detecting the infrared rays of the intruder, and if the level of the received light signal exceeds the alarm level, an intruder alarm is generated. When the signal is output and the self-diagnosis timing signal is input, the received light signal is compared with the above alarm level and Is compared with a lower self-diagnosis level, an intruder alarm is output when the level of the received light signal exceeds the alarm level, and a detector abnormality signal is output when the received light signal is below the self-diagnosis level. It is characterized by being configured.

Further, the infrared type intruder detector according to the present invention is characterized in that the light receiving portion is provided with a shielding plate for intermittently receiving the infrared light generated from the infrared light emitting portion.

[Operation] An infrared intruder detector according to the present invention has two reference levels, an alarm level for detecting an infrared ray from an intruder in a light-receiving signal input during self-diagnosis and a self-diagnosis level lower than the alarm level. And a level determination unit for comparing with. This level determination unit determines the level of the received light signal and the above-mentioned 2
If the level of the received light signal does not reach the self-diagnosis level as a result of comparison with the two reference levels, a detector abnormality signal is output because the detector element or circuit is abnormal. further,
If an intruder exists during self-diagnosis and the level of the received light signal exceeds the alarm level, an intruder alarm is output.

That is, the level determination unit generates a detector abnormality signal when it detects that the light-receiving unit output does not reach the self-diagnosis level during self-diagnosis, and gives an intruder alarm when the light-receiving unit output reaches the alarm level. Output. Thereby, even if there is an intruder at the time of self-diagnosis, the intruder can be detected.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 5 is an infrared light emitting source provided adjacent to the infrared light receiving element 2, and 4 is a condenser mirror provided with deformed portions 4a and 4b (either one may be good). Infrared rays from the intruder are collected by the collecting mirror 4 and received by the light receiving element 2. Further, infrared rays from the infrared light emitting source 5 are reflected by the deformed portions 4a and 4b of the condenser mirror 4 and received by the light receiving element 2.

FIG. 4 shows a detection circuit including the light receiving element 2 and the infrared light emitting source 5, 6 is an amplifier circuit for amplifying the output of the light receiving element 2, 7 is a comparison of the output of the amplifier circuit 6 with an alarm level and a self-diagnosis level, A level determination circuit that outputs an alarm when the level is higher than the alarm level and lower than the self-diagnosis level, 8 is a self-diagnosis timing signal generation circuit, and 9 is a light emission source drive circuit. The level determination circuit 7 is composed of an A / D conversion circuit 7a and a CPU 7b as shown in FIG.

Next, the operation of the above configuration will be described with reference to FIG.
FIG. 6A shows a self-diagnosis timing signal generated from the self-diagnosis timing signal generation circuit 8 at regular intervals,
In response to this signal, infrared light is emitted from the infrared light emission source 5 via the light emission source drive circuit 9, and the light receiving element 2 receives this,
As shown in FIG. 6 (b), an output between the self-diagnosis level and an alarm level higher than this is output via the amplifier circuit 6.
Of course, when there is a signal from the intruder shown in FIG. 6 (c), the amplifier circuit 6 outputs an output above the alarm level.
The level judgment circuit 7 receives the self-diagnosis timing signal and judges the level of the output of the amplifier circuit 6, and when the output of the amplifier circuit 6 is equal to or higher than the alarm level during the period other than the self-diagnosis timing, FIG. The intruder alarm is output as shown in. On the other hand, during the self-diagnosis timing, the level determination circuit 7 issues an intruder alarm for inputs above the alarm level, and does not issue any alarm for inputs above the self-diagnosis level and below the alarm level. (Normal detector), as shown in FIG. 6 (f), when the input is below the self-diagnosis level due to a failure of the light receiving element 2 or the like, a detector abnormal signal is output as shown in FIG. 6 (e). .

FIG. 7 is a flow chart of the above operation. The signal from the self-diagnosis timing generation circuit 8 is a logic level HIGH,
It is binarized like LOW, and the processing is divided into a warning time and a self-diagnosis time (step S1). Also, the input to the level judgment circuit 7 is converted into a digital value by the A / D conversion circuit 7a, and the CPU 7b
It is designed to be read into (steps S2 and S5).

First, at the time of caution, the A / D value previously read in step S3 is compared with the alarm level, and an alarm is generated when the former is greater than or equal to the latter as the light receiving level shown in "Intruder light reception" in Fig. 8. Yes (step S4).

Next, regarding the processing at the time of self-diagnosis, when the former is larger than or equal to the latter by comparing the read A / D value and the alarm level as before, the alarm is output as described above (step S6), When the former is smaller than the latter, it is compared with the diagnostic level (step S7). If the A / D value is greater than or equal to the diagnostic level, as shown in "Self-diagnosis light reception" in Fig. 8, and if it is within the diagnostic time, read the A / D value again and compare again. When has passed, the process returns to step S1 (step S8). On the other hand, if the A / D value is smaller than the diagnosis level and is within the diagnosis time, the A / D value is read again (step S9), but after the above time has elapsed, a detector error signal is output and the processing ends. Yes (step 10).

FIG. 9 shows a second embodiment of the present invention and shows another example of the level judgment circuit 7. The signal from the amplifier circuit 6 is peak-held by the peak-hold circuit 10 and used as one input of the analog comparator 11,
An alarm level and a self-diagnosis level are switchably input to the other inputs of the switches via analog switches 12 and 13, respectively, and compared. This switching is performed by a signal from the self-diagnosis timing signal generating circuit 8 and at least once during the self-diagnosis, the warning level is switched to the self-diagnosis level side. If this switching is not performed, it means that a check is made as to whether or not it is in the alarm level band shown in FIG. In this way, at the time of self-diagnosis, the level is switched at least once to judge which level band in FIG. 8 the output is from the comparator 11, and when an alarm is issued, it is performed via the alarm output unit 14. . In addition, the self-diagnosis level is input to one input of the comparator 15, and the alarm level is input to the other input via the analog switch 12 so that the alarm level can be turned on and off. You can check whether or not. Since the input signal is peak-held when the level is switched, the peak-hold circuit 10 is cleared at the trailing edge of the self-diagnosis timing signal without causing any trouble in comparison with the input signal.

FIG. 10 shows a third embodiment of the present invention. In this example, a condenser mirror 1 similar to the conventional one is used.
Supports an infrared ray 3 from an intruder by a pillar 6 having a structure that does not block the infrared ray 3. Further, FIG. 11 shows a fourth embodiment of the present invention in which an infrared light emitting source 5 is embedded in a condenser mirror 1.

In the above-described first to fourth embodiments, an intruder can be detected when the output of the detection circuit reaches the alarm level except during the self-diagnosis, and the detector can be detected by the output level of the detection circuit during the self-diagnosis. Normal, abnormal and intruder can be detected.

In each of the above-described embodiments, an example is shown in which the infrared light emitting source 5 is directly switched (the switching response is good).

By the way, when an infrared ray emitting source 5 having a poor switching response such as a heating wire is used, the infrared ray emitting source 5
Since the temperature change is slow, the output may not exceed the self-diagnosis level even if the light receiving element 2 is normal.
Therefore, as a countermeasure against this, the infrared light from the infrared light emitting source 5 is intermittently received by the light receiving element 2 so that the temperature of the light receiving element 2 changes intermittently. An example will be described below. 12 (a) and 12 (b) show a fifth embodiment of the present invention. In this example, a shield plate 16 is provided in front of the light receiving element 2 and the infrared light emitting source 5, and the shield plate 16 is used as a motor. A linear drive shaft 17 is used to drive the linear drive shaft 18 so that it can move back and forth. FIG. 13 shows the circuit configuration in this case. The difference from FIG. 4 is that the motor 18 is driven via the motor drive circuit 19 by the self-diagnosis timing signal.

The operation of the embodiment shown in FIG. 5 will be described with reference to the timing chart of FIG. (A) shows the self-diagnosis timing signal, (b) shows the output of the infrared light emitting source 5 driven in synchronization with this signal, and (c) shows the driving of the motor 18 as well. (D) shows the movement of the shielding plate 16, whereby the infrared light from the infrared light emitting source 5 is intermittently received by the light receiving element 2, and the output of the amplifier circuit 6 shown in (e) is a self-diagnostic level output. Is obtained. Further, when there is an intruder as shown in (f), the light receiving element 2 is not shielded by the shielding plate 16 except during the self-diagnosis.
Gives an intruder alarm. When the detector has an abnormality, no output is obtained from the amplifier circuit 6 during the self-diagnosis, and the detector abnormality signal is issued as shown in (h) by the level determination circuit 7. Further, when an intruder is detected during the self-diagnosis, the intruder alarm is issued because the output of the amplifier circuit 6 reaches the alarm level.

FIGS. 15 (a) and 15 (b) show a sixth embodiment of the present invention. In this example, the shielding plate 16 is an arc plate in which a part of a circular plate is cut away. 16 through the rotary shaft 20 motor
The light receiving element 2 and the infrared light emitting source 5 are intermittently shielded by being rotated by 18. Other configurations and operations are the same as those in the above embodiment. FIG. 16 shows a seventh embodiment of the present invention. Even when the infrared light emitting source 5 and the light receiving element 2 are provided below the light collecting mirror 4, the infrared light emitting source 5, the light receiving element 2 and the light collecting mirror 4 are provided. A shielding plate 11 can be provided between the deformed portion (reflection portion) 4a.

In the fifth to seventh embodiments, not only self-diagnosis is possible, but also good switching characteristics can be obtained even when the switching characteristics of the infrared light emitting source 5 are bad, and clear circuit output can be obtained. .

FIG. 17 shows an eighth embodiment of the present invention. The difference between this embodiment and the other embodiments is that the level judging circuit 7 judges the output of the amplifier circuit 6 only as an alarm level. That is. That is, as shown in FIG. 18 (c), the amplification circuit 6 outputs an output above the alarm level by the infrared rays from the infrared light emitting source 5 during self-diagnosis, and the level judgment circuit 7 judges that the detector is normal. Therefore, even if an intruder cannot detect the self-diagnosis, it is not necessary to provide a level difference between the infrared ray from the infrared light emitting source 5 and the infrared ray from the intruder. Of course, except at the time of self-diagnosis, Fig. 18 (d)
If there is an intruder as shown in (e), an intruder alarm is issued as shown in (e), and if the output of the amplifier circuit 6 does not reach the alarm level during self-diagnosis, a detector as shown in (f) is displayed. Generates an abnormal signal.

[Effects of the Invention] As described above, according to the infrared intruder detector of the present invention, the detector output signal is output when the light-receiving unit output does not reach the self-diagnosis level during self-diagnosis, and the light-receiving unit output is When the alarm level is reached, an intruder alarm is output, and the presence of an intruder can be detected at the same time as detecting the abnormality of the self.

[Brief description of drawings]

FIG. 1 is a block diagram of a light receiving portion of an intruder detector according to the first embodiment of the present invention, and FIGS. 2 and 3 are light receiving portion configuration diagrams and timing charts of a conventional intruder detector, respectively.
FIG. 5 and FIG. 5 respectively show a block diagram of an intruder detector according to the first embodiment of the present invention and a block diagram of its level judging circuit, and FIGS. 6 to 8 show the first embodiment of the present invention. Timing chart, flow chart and operation waveform diagram of the intruder detector, FIG. 9 is a block diagram of a level judging circuit according to a second embodiment of the present invention, and FIGS. 10 and 11 are the third and the third aspects of the present invention, respectively. 12 is a front view and a side view of a light receiving portion of an intruder detector according to the fifth embodiment of the present invention. FIGS. 13 and 14 are block diagrams and timing charts of the intruder detector according to the fifth embodiment of the present invention, and FIGS. 15 (a) and 15 (b) are the sixth embodiment of the present invention, respectively. Fig. 16 shows the front view and the plan view of the light receiving part of the intruder detector. Seventh receiving unit diagram of intruder detectors according to the embodiment of the 17th view and FIG. 18 is a eighth configuration diagram and timing Chiya over preparative intruder detector according to an embodiment of each the present invention. 2 ... Light receiving element, 5 ... Infrared emission source, 7 ... Level judgment circuit, 16 ... Blocking plate, 18 ... Motor.

Claims (2)

[Claims] 1. A self-diagnosis timing signal generating section for outputting a self-diagnosis timing signal indicating a timing for performing self-diagnosis, an infrared emitting section for generating infrared rays for self-diagnosis by inputting the self-diagnosis timing signal, an intruder and an infrared ray. When the self-diagnosis timing signal and the light-receiving signal are input and the self-diagnosis timing signal is not input, the light-receiving portion that receives the infrared light generated by the light-emitting portion and outputs the light-receiving signal according to the infrared light reception level Is compared with the alarm level for detecting the infrared rays of the intruder, an intruder alarm is output when the level of the received light signal exceeds the alarm level, and when the self-diagnosis timing signal is input,
The received light signal is compared with the above alarm level, and compared with the self-diagnosis level lower than the above alarm level.If the level of the received light signal exceeds the alarm level, an intruder alarm is output and the received light signal is the self-diagnosis level. An infrared type intruder detector, comprising a level determination unit that outputs a detector abnormality signal in the following cases. 2. The infrared type according to claim 1, wherein the light receiving part is provided with a shielding plate for intermittently receiving the infrared light generated from the infrared light emitting part. Intruder detector.