JP3050587B2 - Infrared sensor device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared sensor device that detects, for example, an approach of a human by detecting infrared rays generated by a human body or the like.

2. Description of the Related Art Conventionally, an infrared sensor for detecting that a human, various small animals, birds, and the like have approached a predetermined facility has been used. An example of the configuration of such an infrared sensor is shown in FIG.
Shown in the figure. The conventional infrared sensor device 1 includes an optical unit 2 such as a lens that collects light in a predetermined detection area A.
And a detection element 3 that receives the light condensed by the optical means 2 and outputs a detection signal having a level corresponding to the amount of change in infrared light in the incident light, and an amplifier that amplifies the relatively weak detection signal. Circuit 4, a filter circuit 5 for selectively filtering a signal in a predetermined frequency band with respect to the amplified detection signal from the amplifier circuit 4, and comparing the signal from the filter circuit 5 with a predetermined reference voltage, for example. A comparison circuit that derives a detection output that goes high when the voltage is equal to or higher than the reference voltage. The output level X of the detection element 3 is determined by the following equation.

X = A × B × C (1) A; temperature difference between normal temperature and intruding object in detection area A; area difference between detecting area and intruding object C; moving speed of intruding object [Hz] According to the experiment of the present inventor in which the conventional infrared sensor device 1 was installed outdoors and the optical means 2 was directed upward to detect the approach of a human body, the following results were obtained.

It operates when the cloud enters the detection area A in the sky.

It operates when the sun is in the detection area A and the cloud blocks the sunlight.

Even when there is no cloud or the sun in the detection area A, the sunlight irradiating the infrared sensor device 1 installed outdoors is blocked by the cloud, the radiation amount of the sunlight in the detection area A and the infrared rays. It operates when the temperature of the sensor device 1 changes.

Regarding the above term, clouds are above the sky at 40 km / h (11.1 kHz)
Although the cloud moves at a speed relatively higher than the walking speed of a human, the cloud usually moves at a position far from the infrared sensor device 1 installed on the ground. The speed is detected as about 0.5m / s (0.5Hz). This moving speed is almost the same as the human walking speed. For this reason, the temperature change when the cloud enters and exits the detection area A is mistaken for the approach of the human body.

Regarding the above term, there is naturally a large difference between the radiated light amount of sunlight and the radiated light amount of clouds, and therefore, there is also a difference in the amount of infrared rays.

Regarding the above term, sunlight contains a relatively large amount of infrared light, and the temperature of the light receiving object increases.
Therefore, when the irradiation of sunlight is interrupted, the object temperature rises and falls, and the detection element 3 malfunctions under the influence of the temperature change.

Problems to be Solved by the Invention As described above, when the infrared sensor device 1 is installed outdoors, malfunctions occur relatively frequently due to changes in the amount of sunlight and movement of clouds in the sky, and According to experiments, it was confirmed that such malfunctions could reach 359 times in one day. Therefore, in the related art, such an infrared sensor device 1 is installed indoors that are not affected by sunlight or used at night. In addition, when installed outdoors, the detection area A is configured to be as small as possible in order to suppress the influence of disturbance light such as sunlight and clouds.

Such a conventional example has a problem that the usability is low and the detection accuracy is low because the detection area A is narrow.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned technical problems, to provide an infrared sensor device whose usability is remarkably improved and which can set a relatively wide detection area.

Means for Solving the Problems The present invention is directed to an optical system that collects light in a specific detection area including a person, a small animal or a bird outdoors, and sunlight and clouds in the sky with a lens having a diameter of 5 cm or more. Means, an infrared detection means for outputting an alternation detection signal of a level corresponding to the amount of change in infrared light in the light condensed by the optical means, and an alternation detection signal from the infrared detection means for moving the detection target. A filtering means for selectively filtering so that a predetermined specific frequency band shifted from a frequency corresponding to the speed becomes a maximum level; an amplification means for amplifying an output from the filtering means to output a direct current; and Discriminating means for comparing and discriminating the output from the means with respect to a reference level; illuminance change detecting means for detecting a change in the amount of irradiation of sunlight other than the detection area; and responding to the output of the illuminance change detecting means. And, when the fluctuation of the irradiation amount of sunlight is not detected, the output from the discriminating unit is derived, and when the fluctuation of the irradiation amount of sunlight is detected, a signal control unit that cuts off the output from the discriminating unit. An infrared sensor device comprising:

According to the present invention, the light within the predetermined detection area is collected by the optical means. The condensed light is incident on the infrared detecting means, and an alternating detection signal having a level corresponding to the amount of change in the infrared light in the light is output. The alternation detection signal is selectively filtered by a filtering means so that a predetermined specific frequency band becomes a maximum level, and an output from the filtering means is amplified by an amplifying means to output a direct current.

Therefore, when a signal of a frequency band separately determined is output from the infrared detecting means when the predetermined detection target enters the detection area, a disturbance factor which is relatively separated from the detection target enters the detection area. In this case, when an error signal in the same frequency band as the separately determined frequency is output from the infrared detecting means, the specific frequency band is set to a value different from the separately determined frequency band.

Thus, in the above-described separately determined frequency band of the alternation detection signal, even if the signal due to the detection target and the disturbance factor has a relatively small deviation, the signal due to the detection target and the disturbance factor is not included in the specific frequency band. There is a level difference, and this level difference is enlarged by the amplification means. Therefore, the discriminating means can clearly discriminate the signal due to the detection object from the signal due to the disturbance factor when comparing and discriminating the output from the amplifying means with respect to the reference level.

Further, a change in the amount of infrared radiation in an external region outside the detection region is detected by the signal control means, and when a change in the amount of radiation is detected, the output from the discrimination means is shut off.
On the other hand, during a period in which a change in the amount of infrared radiation is not detected, the output of the discriminating means is derived. Therefore, it is possible to prevent a situation in which an erroneous signal is output from the infrared detecting means when the amount of infrared radiation in the external region outside the detection region changes due to a disturbance factor outside the detection region, and the detection accuracy is significantly improved. Can be improved.

In this way, the infrared sensor device of the present invention can realize a highly accurate detection operation at an outdoor installation location,
Usability is significantly improved. Further, the necessity of narrowing the detection area in order to prevent a malfunction is eliminated. Therefore, a detection area having a desired size can be set, and the detection accuracy is significantly improved.

By increasing the diameter of the lens of the optical means to a large diameter of 5 cm or more, the difference in infrared rays based on the difference in distance between the detection target and sunlight and clouds above the sky, which is a cause of disturbance, is enlarged, and the discrimination between them is made larger. It is furthermore advantageously carried out.

Embodiment FIG. 1 is a system diagram showing a configuration of an infrared sensor device 11 according to an embodiment of the present invention. The infrared sensor device 11 is
A detection area A1 at least equivalent to the detection area A defined by the optical means 2 in the conventional example shown in the figure is set. In order to increase the amount of light obtained from this detection area A1 as compared with the conventional example, an optical system according to the prior art is used. The optical means 12 employs a lens having a larger diameter (for example, a diameter of 5 cm or more) than the diameter of the lens used for the means 2 (about 1 to 2 cm).

The lens having a diameter of 5 cm or more is defined so that the human body can be detected at a distance of 12 m using the infrared sensor device 11 of the present embodiment, and the surrounding temperature environment and the object (human body) can be detected. Other apertures are appropriately determined by changing the average temperature and the measurement distance.

The light condensed by the optical unit 12 is incident on the infrared detecting element 13, and a detection signal S1 of an AC level corresponding to a change amount of the infrared light in the incident light is output. Here, when the infrared sensor device 11 is installed outdoors to detect the approach of a human body, the walking speed of a human is usually about 0.5 m / s, that is, about 0.5 Hz. On the other hand, the detection signal S1 is, for example,
With 1.5 Hz as the center frequency of the filtering, the signal is filtered by a filter circuit 14 having, for example, a characteristic of a normal curve, and the filtered output S2 is amplified by an amplifier circuit 15 over the entire frequency band, and a direct current is output.

The amplified output S3 from the amplifying circuit 15 is input to the comparing circuit 16, and two kinds of separately input reference voltages V1 and V2 (V1> V2)
Is compared with the reference voltage V1 or the reference voltage
When at least one of the cases where V2 is smaller than V2 is satisfied, a discrimination signal S4 indicating that the human body has entered the detection area A1 is output.

On the other hand, the infrared sensor device 11 is provided with an illuminance change detection circuit 18 for detecting a change in the amount of irradiation of sunlight in an external region outside the detection region A1, that is, a change in sunshine on the infrared sensor device 11. The illuminance change detection circuit 18 outputs an illuminance change signal S5 to the gate circuit 17 when the sunshine changes as described above, and the gate circuit 17 outputs the discrimination signal S4 while the illuminance change signal S5 is being input. Cut off. on the other hand,
During a period when the illuminance change signal S5 is not input, the discrimination signal S4 is generated and input to the sound generation circuit 19, for example.

In the sound generation circuit 19, during the period in which the discrimination signal S4 is input, for example, an audio signal is read from an integrated circuit element storing the audio signal and is generated from the speaker 20. The infrared sensor device 11 is provided with a power supply circuit 22 connected to the solar cell 21. The power supply circuit 22 charges the internal battery 23 and generates electric power for driving the infrared sensor device 11.

FIG. 2 is a perspective view showing the appearance of the infrared sensor device 11. As shown in FIG. The infrared sensor device 11 includes a solar cell 21 covered with a transparent cover 34 on the upper surface of a substantially long cylindrical housing 33. On the front surface of the housing 33, a lens 35 and the speaker 20 constituting the optical means 12 are arranged, and on the side, a power switch 36, a volume adjustment knob 37, and a sensor sensitivity adjustment knob
38 is placed.

FIG. 3 is a circuit diagram showing an electrical configuration of the infrared sensor device 11. The detection element 13 is realized as a photoelectric conversion element 24, and its gate is connected to a power supply line l1 of a power supply voltage V0 through a parallel circuit of capacitors C1 and C2 and an electrolytic capacitor C3, and is directly connected to a ground line l2. Connected to. The drain D of the photoelectric conversion element 24 is connected to the power supply line l1 via the resistor R1, the source S is connected to the non-inverting input terminal of the operational amplifier 25 via the resistor R2, and the capacitor C4 and the resistor R3 are connected in parallel. Ground line through the circuit
Connected to l2.

One end of the inverting input terminal of the operational amplifier 25 is connected to the other end of the capacitor C5 whose one end is connected to the non-inverting input terminal, and is connected to the ground line l2 via a series circuit of a resistor R4 and an electrolytic capacitor C6. . The negative feedback circuit of the operational amplifier 25 is provided with a parallel circuit including a diode D1, a resistor R5, and a capacitor C7.

The output terminal of the operational amplifier 25 is connected to a connection point between the resistors R6 and R7 connected in series between the power supply line l1 and the ground line l2, and is operated via an electrolytic capacitor C8, a resistor R8, and a variable resistor VR. Connected to inverting input terminal of amplifier 26.

Between the connection point between the resistors R6 and R7 and the ground line l2, an electrolytic capacitor C9 was connected in parallel with the resistor R7, and the resistor R9 and one end were connected to the inverting input terminal of the operational amplifier 26. The other end of the capacitor C10 is connected to the non-inverting input terminal of the operational amplifier 26. Operational amplifier 26
In the negative feedback circuit, a parallel circuit of a resistor R10 and a capacitor C11 is used, and a variable resistor tap is connected to the variable resistor VR from a connection point of the resistor R10 on the inverting input terminal side.
Here, the amplifier circuit 15 includes the operational amplifiers 25 and 26, and the filter circuit 14 includes the electrolytic capacitor C9 and the resistor R7.

The output terminal of the operational amplifier 26 is connected to the inverting input terminal and the non-inverting input terminal of the operational amplifiers 27 and 28 that constitute the comparison circuit 16 as a so-called window comparator.

Between the power line l1 and the ground line l2, a resistor R11,
A voltage dividing circuit including R12 and R13 is provided, and a connection point between the resistors R11 and R12 is connected to a non-inverting input terminal of the operational amplifier 27, and is connected to a ground line l2 via an electrolytic capacitor C12. . On the other hand, the connection point between the resistors R12 and R13 is connected to the inverting input terminal of the operational amplifier 28 and to the ground line l2 via the capacitor C13.

A resistor R1 is provided between the power line l1 and the ground line l2.
4, a series circuit of R15 and a capacitor C14 are connected, and the output terminals of the operational amplifiers 27 and 28 are individually connected to the diodes D2 and D3 in a reverse bias state, respectively, and are commonly connected to a connection point of the resistors R14 and R15. Connected. From the connection point between the resistor R15 and the capacitor C16, the discrimination signal S4 is output via the resistor R16.

On the other hand, between the power supply line l1 and the ground lines l2 and D3, a photodiode constituting the illuminance change detection circuit 18 is provided.
A series circuit of the PD and the resistor R17 is connected. Between the connection point between the photodiode PD and the resistor R17 and the power supply line l1,
A series circuit of electrolytic capacitor C15 and resistor R18 is connected,
A series circuit of an electrolytic capacitor C16 and a resistor R19 is connected between the connection point and the ground line l2.

Each connection point between the capacitors C15 and C16 and the resistors R18 and R19 is connected to each base of the transistors Q1 and Q2, and the emitters of the transistors Q1 and Q2 are connected to the power supply line l1 and the ground line l2, respectively. A series circuit of resistors R20 and R21 is provided between the collector of the transistor Q1 and the ground line l2, and the connection point is connected to the base of the transistor Q3. The collector of transistor Q3 is a resistor
The power supply line l1 is connected via R22, and the emitter is connected to the ground line l2.

On the other hand, the collector of the transistor Q2 is connected to the collector of the transistor Q3, and is input to one input terminal of the NAND circuit 29, and the output is connected to the capacitor C17 and the resistor R23.
And is connected to one input terminal of the NAND circuit 30 through the series circuit. The connection point between the capacitor C17 and the resistor R23 is connected to the ground line l2 via the resistor. The other input terminal of the NAND circuit 30 is connected to the power supply line l1, and the output terminal is
Connected to the other input terminal of the circuit 29 and a NAND circuit 31
Connected to one input terminal.

The discrimination signal S4 output from the resistor R16 has one input terminal connected to the other input terminal of the NAND circuit 32 connected to the power supply line l1, and the output terminal connected to the other input terminal of the NAND circuit 31. . The output terminal of the NAND circuit 31 is a resistor
The base of transistor Q4 is connected via R25. The transistor Q4 is connected to the ground line l2, and the collector is connected to the power supply line l1 via the resistor R26.
It outputs a discrimination signal S4 output from the gate circuit 17 shown in the figure.

Hereinafter, the operation of the infrared sensor device 11 of the present embodiment will be described. The infrared sensor device 11 of this embodiment is installed outdoors and detects the approach of a detection target such as a human body, a small animal or a bird to the detection area A1 shown in FIG. In the present embodiment, in this detection operation, the infrared sensor device 11 is used.
Is installed outdoors to remove a disturbance factor based on a change in sunshine due to movement of sun rays and clouds, thereby realizing a highly accurate detection operation.

4 to 9 are graphs for explaining the operation of the circuit of this embodiment. Reference is also made to these drawings. As described in the section of the related art, the speed at which the human body enters and exits the detection area A1 is about 0.5 m / s (0.5 Hz). It is almost the same as the moving speed at the time of detection. On the other hand, the amount of infrared radiation differs between a human body approaching the infrared sensor device 11 and a cloud moving in the sky.

Therefore, the amount of infrared radiation obtained from the human body and clouds is
Although there are differences indicated by lines L1 and L2 in FIG. 4, the levels are close to each other at the frequency of about 0.5 Hz. In the present embodiment, in order to enlarge the difference in the amount of radiation, the lens 35 included in the optical means 12 has a relatively large diameter (a diameter of 5 cm or more).
And Thereby, the output S1 from the detection element 13 becomes the lines L3 and L4 shown in FIG. 5 in the case of the human body and the cloud, respectively.

As described above, both the human body entering and exiting the detection area A1 and the movement of clouds in the sky are detected by the detection element 13 as a frequency band of 0.5 Hz, and the characteristics thereof are substantially close to a normal curve. Therefore, as shown in FIG. 5, at 0.5 Hz between the lines L3 and L4 representing the output from the human body and the cloud, the deviation ΔV1
Is set. However, in the present embodiment, the output level of the cloud is lower than that of the human body, and the deviation between the two output levels increases as the frequency deviates from 0.5 Hz. For example, in the vicinity of the frequency of 1.5 Hz in the lines L3 and L4, the deviation is considerably larger than in the case of 0.5 Hz, and the deviation becomes ΔV2.

Therefore, the output signal S1 is band-filtered by the filter circuit 14 in order to extract the deviation ΔV2 in the frequency band of 1.5 Hz.
As a result, lines L5 and L6 shown in FIG. 6 are obtained, and a relatively large deviation ΔV3 is obtained at a center frequency of 1.5 Hz.
Further, by amplifying the filtered output S2 from the filter circuit 14 shown in FIG. 1 by the amplifier circuit 15, the lines L7 and L8 shown in FIG. 7 are obtained. In the center frequency band of 1.5 Hz, the deviation ΔV3 A significantly larger deviation ΔV4 is obtained.

The amplifier circuit 15 is connected between the power line l1 and the ground line l2, and the voltage V0 is applied to the power line l1 as shown in FIG. The amplified output S3 from the detector 15 has a positive polarity as shown in FIGS. 7 and 8 described later, that is, is a DC signal, and its level is a detection signal S1 which is an output of the infrared detecting element 13. Fluctuates in response to Such a level variation in one polarity of the signal may also be referred to herein as an alternating current. Therefore, since the output S3 of the amplifier circuit is an AC signal having a positive polarity and the level thereof fluctuates, the comparison circuit 16 outputs the operational amplifier 2 as described above.
It is configured as a so-called window comparator using 7,28. That is, the power supply voltage V0 is divided by the resistors R11, R12, and R13 shown in FIG.
Set the reference voltage V2. When the amplified output S3 is higher than the first reference voltage V1 or lower than the second reference voltage V2, the output of each operational amplifier 27, 28 becomes low level, and the capacitor C14 responds accordingly. In order to charge the discharge amount, a current flows from the power supply line l1 through the resistor R16, and the terminal voltage of the resistor R16 is output as the discrimination signal S4 shown in FIG.

(A) When the Photodiode PD Detects Constant Illumination In such a case, a constant current I flows through the photodiode PD, and the anode of the photodiode PD is kept at a constant potential. Therefore, resistors R18 and R19 are connected to capacitors C15 and C16.
And no current flows, and the bases of the transistors Q1 and Q2 are held at the high level or the low level, respectively.
All of them are in the cutoff state.

Therefore, the state in which the power supply potential V0 via the resistor R22 is input as the logic “1” continues to the NAND circuit 29. Therefore, the output level of the NAND circuit 29 does not change, and accordingly,
One input terminal of the NAND circuit 30 is connected to the power supply line l1 and has a logic “1”, while the other input terminal has resistors R24 and R2
Connected to the ground level via 3 and a logic "0" is input. As a result, the output of the NAND circuit 30 is fixed to logic “1”, and the NAND circuit 31 inverts the signal from the NAND circuit 32 and outputs the inverted signal.

The discrimination signal S4 has one input terminal connected to the power supply line l1 and is input to the NAND circuit 32 which is always logic “1”, and thus the inverted output ▲ ▼ is obtained.
The signal inverted at the circuit 31 is applied to the base of the transistor Q4.
S4 is input. Therefore, the output signal S4 is output from the output terminal 39. This output signal S4 is a sound generation circuit
A predetermined sound or the like is input from the speaker 19 and is generated from the speaker 20.

(B) When the Output of the Photodiode PD Decreases This case shows a state in which the irradiation of the photodiode PD with sunlight is blocked by, for example, the movement of clouds. The change in the potential of the anode of the photodiode PD is taken out via the capacitors C15 and C16, and the transistor Q1 is turned on and the transistor Q3 is turned on. Transistor Q2 is in a shielded state. As a result, one input terminal of the NAND circuit 29 is forced to a low level, and a high-level signal is derived.

This signal is delayed in the capacitor C17 by a time constant determined in advance by the capacitance of the capacitor C17 and the resistance value of the resistor R24, and a high-level signal is input to the NAND circuit 30. Accordingly, the NAND circuit 30 outputs a low-level signal, forcing the output of the NAND circuit 31 to a high level, turning on the transistor Q4, and forcing the output terminal 39 to a low level.
At this time, even if the photoelectric conversion element 24 detects a change in the amount of infrared rays, the discrimination signal S4, which is the output, is blocked.

That is, such a state may be an output generated due to a change in the temperature of the photoelectric conversion element 24 due to sunlight being blocked by the movement of clouds above the infrared sensor device 11 set outdoors. Because there is.

(C) When the output of the photodiode PD increases The change in the potential of the anode of the photodiode PD is taken out via the capacitors C15 and C16, the transistor Q1 is in a shielded state, and the transistor Q2 is turned on. This allows NA
The one input terminal of the ND circuit 29 is forced to a low level. Thereafter, the NAND circuits 29, 30, 32, and 31 perform the same operation as described in the above section (B), forcing the output terminal 39 to a low level.

In such a case, from the state where the sunlight to the infrared sensor device 11 set outdoors is blocked by, for example, clouds in the sky, the clouds move and the sunlight directly irradiates the photoelectric conversion element 24, This is because there is a high possibility that the discrimination signal S4 has been generated due to a change in temperature.

As described above, the infrared sensor device 11 of this embodiment is
The movement of a cloud above the sky having the same frequency band as the movement of the human body and the movement of the human body can be eliminated by making the lens of the optical means 12 larger than before and using the filter circuit 14 and the amplification circuit 15 described above. Like that. Further, in this embodiment, an illuminance change detecting circuit 18 is further provided so that the disturbance caused by the movement of the cloud and the change in the radiation amount due to the movement of the cloud can be almost completely removed.

The present inventor has proposed an infrared sensor device 1 having a configuration of the related art.
Using the configuration excluding the illuminance change detection circuit 18 of the present embodiment and the infrared sensor device 11 of the present embodiment, the detection operation was observed with the optical unit 12 facing the sky in cloudy weather. The results are shown in Table 1 below.

That is, in the conventional example, a malfunction occurred due to a disturbance factor of 359 times, whereas the illuminance change detection circuit 18
In the configuration excluding, the number of malfunctions due to disturbance factors is reduced to 31 times, and in the infrared sensor device 11 of the present embodiment, the number of operations is reduced to one due to disturbance factors.

In this manner, the present embodiment can detect only the movement of the human body with high accuracy even when the apparatus is installed outdoors. Therefore, the use environment is not limited to indoors or at night, and usability is remarkably improved. Also, the need to set the detection area A1 to be relatively small in order to prevent malfunction due to disturbance factors is eliminated, and a desired relatively wide detection area A1 can be set, thereby significantly improving the detection accuracy. it can.

Advantageous Effects of the Invention As described above, according to the present invention, when a predetermined detection target, which is a person, a small animal, or a bird, enters the detection region outdoors, a signal output from the infrared detection unit is a signal of the detection target. A frequency corresponding to the moving speed, as described above, is a signal having a maximum level of, for example, 0.5 Hz.
The signal includes a predetermined specific frequency band, for example, a signal component of 1.5 Hz. When sunlight and a cloud above the sky, which are disturbance factors separated by a relatively large distance from the detection target, enter the detection region, the signal output from the infrared detection means corresponds to the moving speed of the detection target described above. The same as the frequency,
As described above, the signal has a maximum level of 0.5 Hz, for example, and includes the signal component of the predetermined specific frequency band. In the above-described embodiment, the frequency band corresponding to the moving speed of the detection target is referred to as a separately determined frequency band.

In the present invention, the optical means collects light using a lens having a diameter of 5 cm or more, thereby detecting the output level L3 (see FIG. 5 described above) when detecting the detection target and detecting sunlight and clouds in the sky. Differences ΔV1 and ΔV2 from output level L4 at the time can be increased. It was found that the difference ΔV2 in the predetermined specific frequency band shifted from the frequency band was larger than the difference ΔV1 in the frequency band corresponding to the moving speed of the detection target. Therefore, in the present invention, the output signal S1 from the infrared detecting means is provided to the filtering means to filter the component of the predetermined specific frequency band, and the predetermined specific frequency band where such a large difference ΔV2 exists is provided. Are amplified by the amplifying means and compared and discriminated by the discriminating means. Therefore, the identification of the detection target by the discriminating means is facilitated.

In other words, the predetermined specific frequency band of the filtering means deviates from the above-described separately determined frequency band corresponding to the moving speed of the detection target, for example, the above-mentioned 0.5 Hz, and is, for example, 1.5 Hz. As a result, the difference ΔV1, ΔV2 between the output levels L3, L4 is set to a value larger than the separately determined frequency band in the specific frequency band (that is, ΔV1 <Δ
V2), thus making it possible to reliably perform comparison discrimination by the discrimination means.

Accordingly, in the above-described separately determined frequency band of the alternating detection signal, even if the signal has a relatively small deviation due to the detection target and the disturbance factor, the signal due to the detection target and the disturbance factor does not have a level in the specific frequency band. There is a difference, and this level difference is magnified by the amplification means. Therefore, the discriminating means can clearly discriminate the signal of the detection target from the signal of the disturbance factor when comparing and discriminating the output from the amplifying means with respect to the reference level. In addition, a change in the amount of infrared radiation, which is the amount of sunlight irradiated in the external region outside the detection region, is detected by the illuminance change detection unit, and when a change in the amount of radiation is detected, the output from the discrimination unit is shut off. . On the other hand, during a period in which a change in the amount of infrared radiation is not detected, the output of the discriminating means is derived. Therefore, it is possible to prevent a situation in which an erroneous signal is output from the discriminating means when the amount of infrared radiation in the external region outside the detection region is unevenly distributed due to a disturbance factor outside the detection region, and detection accuracy is significantly improved. Can be improved.

In this way, the infrared sensor device of the present invention can realize a highly accurate detection operation regardless of the indoor or outdoor installation location, and the usability is remarkably improved. In addition, the necessity of narrowing the detection area in order to prevent a malfunction is eliminated, so that a detection area having a desired size can be set, and the detection accuracy is significantly improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an infrared sensor device 11 according to one embodiment of the present invention, FIG. 2 is a perspective view of the infrared sensor device 11, and FIG. 3 is an electric circuit diagram showing a configuration example of the infrared sensor device 11. FIG. 4 is a graph showing the output of a conventional detection element;
FIG. 5 is a graph showing the output of the detection element of this embodiment, and FIG.
The figure shows a graph showing the filter output S2, and FIG. 7 shows the amplified output S3.
FIG. 8 is a graph showing the operation of the comparison circuit,
FIG. 9 is a time chart showing a discrimination signal S4, and FIG. 10 is a block diagram showing a configuration of a conventional example. 11 infrared sensor device, 12 optical means, 13 detection element, 14 filter circuit, 15 amplifier circuit, 17 gate circuit, 18 illuminance change detection circuit

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinichiro Watari 1166, Haseno, Jabizo-cho, Yokaichi City, Shiga Prefecture 6 Inside the Shiga Yokaichi Plant of Kyocera Corporation (56) References JP-A-62-162929 (JP, A) JP-A-61-219887 (JP, A) JP-A-63-273020 (JP, A) JP-A-2-187691 (JP, A) JP-A-62-124488 (JP, A) JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01J 1/00-1/46 G01J 5/00-5/56 G01V 8/12

Claims (1)

(57) [Claims] 1. An optical means for condensing light in a specific detection area including a detection target, which is a person, a small animal or a bird, and sunlight and clouds in the sky, with a lens having a diameter of 5 cm or more, outdoors. Infrared detection means for outputting an alternation detection signal at a level corresponding to the amount of change in infrared light in the light condensed by the means; and an alternation detection signal from the infrared detection means, the frequency corresponding to the moving speed of the detection target. A filtering means for selectively filtering the predetermined specific frequency band shifted from the maximum level, an amplifying means for amplifying an output from the filtering means and outputting a direct current, and an output from the amplifying means. Discriminating means for comparing and discriminating with respect to a reference level; illuminance change detecting means for detecting a change in irradiation light amount of sunlight other than the detection area; and irradiating light amount of sunlight in response to an output of the illuminance change detection means. If the variation is not detected to derive an output from said discrimination means, if the fluctuation of the irradiation light amount of sunlight is detected,
An infrared sensor device comprising: a signal control unit that cuts off an output from the discrimination unit.