JPH07120316A - Infrared type human body detector - Google Patents

Abstract

PURPOSE:To make it passible to continue outputting of a human body detection signal properly when a human body exists within a detection area while the outputting of the human body detection signal is stopped in a short time when the human body leaves the detection area. CONSTITUTION:The frequency at which an infrared detection signal with an output level higher than a fixed reference value is outputted within a fixed time from an infrared detector is counted. A control means 6 is provided to perform a control as follows: When counts exceeds a specified reference frequency because a moving value of a human body within a detection area is large, off delay time is made shorter to output a human body detection signal continually and when the counts do not reach the reference frequency because the motion of the human body is limited, the off delay time for th continuous outputting of the human body detection signal is made larger.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared ray type suitable for detecting the presence of a human body by detecting infrared rays emitted from the human body and controlling ON / OFF of a desired device such as a lighting device in accordance with the presence of the human body. The present invention relates to improvement of a human body detection device.

[0002]

2. Description of the Related Art As an infrared type human body detecting apparatus of this type, various types using a pyroelectric element as an infrared detecting element have been proposed. However, this pyroelectric element outputs an output according to a change in temperature. The level signal is output. Therefore, when an infrared type human body detection device of this type is used for on / off control of lighting equipment, when the human body moves within the detection area and the detection beam is blocked, a high output above a certain reference value is output. Although the level infrared detection signal is output, when the human body stands still in the detection area, the infrared detection signal is not output and it is determined that the human body does not exist.

Therefore, conventionally, when it is determined that a human body has entered the detection area, the human body detection signal is continuously output for a predetermined time (off-delay time) thereafter, and that time is output. The output of the human body detection signal is stopped when the time is up.
Further, the off-delay time is restarted every time an infrared detection signal exceeding a certain reference value is output before the time is up. Therefore, as long as a human body exists in the detection area and the detection signal is output at appropriate time intervals, the human body detection signal can be almost certainly continuously output to maintain the lighting state of the lighting fixture.

[0004]

However, in the above-mentioned prior art, the off-delay time for continuously outputting the human body detection signal is set as one type of invariant time, and for example, this off-delay time is set to 5 minutes. When set, the human body detection signal was continuously output for at least 5 minutes in any situation. Therefore, conventionally, even if the human body that has entered the detection area immediately exits the detection area, the human body detection signal is continuously output for 5 minutes after the entry. For this reason, even though there is no human body in the detection area, the lighting fixture remains lit for a long time, which is a waste. still,
In order to eliminate this, the off-delay time may be set to a short time. Then, even if there is a human body in the detection area, the human body detection can be done by just resting the human body for a while. The problem that the output of a signal stopped and a lighting fixture was turned off occurred, and the said difficulty could not be eliminated appropriately.

The present invention has been proposed in view of the above points. When the human body exits the detection area, the output of the human body detection signal is stopped in a short time, while when the human body exists in the detection area. Its purpose is to appropriately continue the output of the human body detection signal.

[0006]

SUMMARY OF THE INVENTION The present invention has
Rather than adopting only off-delay time
Two types of long and short off-delay time are adopted, and these two types of off-delay time exist in the detection area when the human body moves out of the detection area with a large movement and when the human body moves with little movement. The present invention was invented under a completely new idea, which has never been seen in the past, in which a human body detection signal is output in a state as close as possible to the actual state of the presence or absence of a human body in the detection area.
That is, the present invention is directed to a condenser lens for forming a constant detection area in which a plurality of detection beams are present, and infrared detection of an output level according to a change amount of infrared rays condensed through the condenser lens. Equipped with an infrared detection element that outputs a signal,
When an infrared detection signal having an output level higher than a predetermined reference value is output from the infrared detection element and it is determined that the human body is detected, the human detection signal is output for a preset off delay time. An infrared human body detection device configured to output continuously,
Two types of long and short off-delay times are set as the off-delay time, and the number of times an infrared detection signal having an output level higher than the predetermined reference value is output is counted, and this count number is predetermined. The human body detection signal is continuously output within the time width of the off-delay time on the short time side when the number of times is equal to or greater than the predetermined reference number within the predetermined time, while the human body detection signal is set to be long when the count number is less than the reference number. The infrared-type human body detection device is provided with a control means for performing control so that continuous output is performed with a time width of an off delay time on the time side.

[0007]

In the infrared type human body detecting device according to the present invention having the above-mentioned structure, the movement of the human body existing in the detection area becomes large when the human body exits the detection area, and a plurality of detections are made in a short time. Since the beams are sequentially blocked, the infrared detection signal having a high output level exceeding a certain reference value is output many times within a predetermined certain time, and the count number exceeds a predetermined certain reference number. In this case, the short-side off delay time is applied. Therefore, the output of the human body detection signal is stopped in a short time after the human body exits the detection area, and the human body detection signal is not continuously output for a long time thereafter.

On the other hand, when a human body is present in the detection area but the movement of the human body is small, unlike the above case, a large number of detection beams are not interrupted sequentially in a short time. The number of times that an infrared detection signal having a high output level exceeding a certain reference value is output within a certain time is small. Since the count number does not reach the predetermined reference number of times, the long-side off delay time is applied in this case. Therefore, even if the movement of the human body is stopped, the output of the human body detection signal is not immediately stopped by this.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example of a hardware configuration of an infrared human body detection device K according to the present invention. The human body detection device K includes a condenser lens 1, an optical filter 2 that transmits only infrared rays in a wavelength band of about 7 to 14 μm,
An infrared detection element 3 that outputs an infrared detection signal having an output level corresponding to a change in the amount of received infrared light; a signal amplifier 4 that amplifies the detection signal output from the infrared detection element 3;
A band filter circuit 5 for removing unnecessary frequency components from the amplified infrared detection signal, a signal processing unit 6 including a CPU corresponding to the control means according to the present invention, and a desired device such as a lighting fixture are turned on. An output control unit 7 for outputting a relay signal for performing off control is provided.

Of the above, the condenser lens 1 is shown in FIG.
A dome-shaped lens as shown in (a) and (b),
The spherical surface is divided into, for example, 16 to form a so-called Fresnel lens array in which a total of 16 Fresnel lenses 10 for collecting infrared rays are connected in series. The material of each Fresnel lens 10 is, for example, polyethylene resin, and the thickness thereof is fixed to, for example, 0.8 [mm] to suppress the attenuation of infrared rays transmitted through each lens. The focal length of each of these Fresnel lenses 10 is set to, for example, 14.5 [mm].

As the infrared detecting element 3, for example, a pyroelectric element is applied. As an example of the infrared detection element 3, as shown in FIGS. 3A and 3B, an infrared ray connected to a plurality of terminals 33 in a shield case 32 in which the optical filter 2 is arranged in the opening window 31. The one provided with the pyroelectric chip 34 for detection is applied. This pyroelectric chip 34
Is provided on the surface portion of the four detection element surfaces 30 (30a to 30d) functioning as an infrared light receiving portion in a state of being connected in series, and the amount of infrared rays received by these four detection element surfaces 30 is When a change occurs, the infrared detection signal of the output level (voltage level) corresponding to the change is output. However, a negative voltage infrared detection signal is detected on the detection element surfaces 30a and 30c, and a negative voltage infrared detection signal is detected on the detection element surfaces 30b and 30d.
Is set so that positive voltage infrared detection signals are output. Each of the sensing element surfaces 30 is, for example, 1
The side dimension S is 1.1 [mm], and the mutual dimension Sa is 1.5.
It is set to [mm].

By using the condenser lens 1 provided with the infrared detecting element 3 and the plurality of Fresnel lenses 10, the human body detecting device K according to the present embodiment has a plurality of members as shown in FIGS. 4 (a) and 4 (b). It is possible to obtain the detection area A in which the detection beams b of 1 are arranged at regular intervals. As a specific example, when the human body detection device K is attached to the ceiling surface having a height H from the floor surface of 2 [m], the width Sb of each detection beam b formed on the floor surface.
Is about 20 cm, and the distance between the detection beams b can be set to be substantially equal to that. It should be noted that, of the plurality of detection beams b, adjacent detection beams have positive and negative electrical characteristics that are opposite to each other.

With respect to the movement of the human body in the detection area A formed as described above, the infrared detecting element 3 is to detect a change in the amount of infrared light received, and the infrared detecting element 3
The low-frequency and high-frequency frequencies, which are unnecessary signal components of the infrared detection signal output from, are cut by the signal amplification unit 4 and the band-pass filter circuit 5 to obtain an infrared detection signal having a bandpass characteristic. Specifically, the infrared detection signal is as follows. 5 and 6 show the case where the human body M blocks one detection beam b. Of these, FIG. 5 shows the case where the moving speed v of the human body M is slow. In this case, the incident infrared ray changes as shown in FIG. 5A and the infrared detection signal as shown in FIG. Exceeds the predetermined reference value VTH (which is set to both positive and negative) twice. That is, two output pulses are obtained. FIG. 6 shows a case where the moving speed v of the human body M is fast. In this case, as shown in FIG. 6B, the infrared detection signal exceeds the predetermined reference value VTH only once and outputs one shot. A pulse is obtained. This is because when the human body M blocks the detection beam b quickly,
This is because the response of the infrared detecting element 3 cannot follow the change of the incident infrared rays.

7 and 8 show the case where the human body M intercepts the two detection beams b, b, and FIG. 7 shows the moving speed v of the human body M.
Is slow, and FIG. 8 shows a case where the moving speed v is fast. When the moving speed v of the human body M is slow, as shown in FIG. 7B, the infrared detection signal exceeds the constant reference value VTH four times, and four output pulses are obtained. On the other hand, when the moving speed v is high, the response of the infrared detection element 3 is delayed, so that the infrared detection signal exceeds the constant reference value VTH three times and three times as shown in FIG. 8B. Output pulses are obtained.

As described above, in the human body detection device K according to this embodiment, when the movement amount of the human body M is large and the two detection beams b, b are blocked, the infrared detection signal has a predetermined reference value VTH. In the short time, the number of times exceeds 3 times or more, whereas when the amount of movement of the human body M is small and only one detection beam b is blocked, the number of times the infrared detection signal exceeds the reference value VTH is once. Or it will stop twice.

The signal processing unit 6 shown in FIG. 1 counts the number of output pulses of the above-mentioned infrared detection signal, that is, the number of times the infrared detection signal exceeds the reference value VTH within a fixed time, and determines the count number in advance. It is compared with the specified reference number. As the reference number of times, for example, a value of 3 times is adopted, and when the count number is 3 or more, the movement amount of the human body M is large, and when the number of times is less than the reference number of 3, the human body M It is determined that the operation amount is small, and two types of long and short off delay times TL and TS are switched and controlled according to this determination. That is, the signal processing unit 6 detects the detection area A
A human body detection signal is output to the output control unit 7 when it is determined that a human body has entered the inside, and this signal output is continued for a predetermined off delay time TL or TS. The off-delay time is, for example, one minute as the short off-delay time TS when the count number of the output pulse is three or more, and the long off-delay time when the count number is less than three times. T
For example, 5 minutes is applied as L. It is preferable that the off-delay times TL and TS are configured so that they can be arbitrarily increased / decreased by a switch operation according to the usage conditions of the human body detection device K and the like.

If there is an infrared detection signal output exceeding the reference value VTH before the off-delay times TL and TS elapse, the signal processing section 6 newly restarts counting the off-delay time from the beginning. . Further, when the infrared detection signal having the output level exceeding the reference value VTH is not output during the measurement of the off-delay time thereafter, the output of the human body detection signal is stopped when the off-delay time is up. As a result, the relay signal output from the output control unit 7 is also turned off, and the lighting fixture is turned off.

The count time T for counting the number of output pulses of the infrared detection signal exceeding the reference value VTH may be determined as follows. That is, when the distance between the two detection beams b and b is L and the normal moving speed of the human body M is v, the time required to interrupt the two detection beams b and b is L / v. Therefore, T = L / v may be set. In the present embodiment, the mutual distance L between the central positions of the adjacent detection beams b and b is about 40 [cm], and the moving speed of the human body is assumed to be 0.1 [m / s] with a margin. Then, the count time T may be about 4 seconds.

Whenever a series of infrared detection signals exceeding the reference value VTH are output, the signal processing unit 6 outputs the infrared detection signals within the range of the count time T from the time when the reference value VTH is first exceeded. Count the number of pulses. Also,
Since it is necessary to continue outputting the human body detection signal while counting the number of output pulses within the count time T, in this embodiment, the human body detection signal is output until the count time T elapses. Is continued unconditionally, and the timing of the off-delay times TL and TS is configured to start from the time when the count time T has timed up.

Next, the infrared type human body detecting device K having the above structure
The action of will be described. In this embodiment, for convenience, as shown in FIG. 9, the human body M existing at the external position P1 of the detection area A enters the position P2 in the detection area A and stands still for a while, and then the detection area A is detected. The case of exiting to the position P3 outside the vehicle will be described as an example. First, when the human body M moves from the position P1 to the position P2 and enters the detection area A, 2
The two detection beams b, b are blocked. Therefore, in this case, as shown by the arrow a in FIG. 10A, the output level of the infrared detection signal exceeds the reference value VTH three times or more within the count time T set to 4 seconds (human body M If the moving speed v is fast, it will be 3 times, and if it is slow, it will be 4 times). The number of output pulses of the pulse exceeding the reference value VTH is counted by the signal processing unit 6, and the number of counts is a predetermined reference number (3 times) or more. As a result, the signal processing unit 6 selects the short off-delay time TS set to 1 minute, and starts counting the off-delay time TS after the count time T has elapsed (FIG. 10C). , (D)). During that time, the output state of the human body detection signal is maintained, and the lighting fixture is maintained in the lit state.

Next, when the movement amount of the human body M that has moved to the position P2 in the detection area A is small and only one detection beam b is blocked, as shown by an arrow b in FIG. The output level of the detection signal exceeds the reference value VTH only once or twice. In this case, since the number of output pulses within the count time T of 4 seconds does not reach 3 times as the reference number, the signal processing unit 6 selects 5 of the two types of long and short off-delay times TL and TS. A long off delay time TL set to minutes is selected (see FIGS. 10E and 10F). As a result, for the next 5 minutes, even if the human body M remains stationary, the output of the human body detection signal is continued, and the lighting fixture maintains the lighting state. Despite the presence of the human body M in the detection area A, the malfunction of the lighting fixture being unduly turned off does not occur.

Further, when the human body M exits from the detection area from the position P2 to the position P3, since the two detection beams b, b are also blocked, as shown by the arrow c in FIG. 10 (a), The infrared detection signal exceeds the reference value VTH three times or more within the count time T of 4 seconds. Then, in this case, the short delay time (1 minute) of the off-delay time TS is applied (FIGS. 10 (g) and 10 (h)), and after that, 1 minute is counted and the time is up. Then, the output of the human body detection signal is stopped. Further, this turns off the lighting equipment. As a result, it is possible to prevent the lighting fixture from being unnecessarily turned on for a long time after the human body M exits the detection area A.

In the above embodiment, the two detection beams b, b
Although it is determined that the human body M has moved when the object is blocked, the present invention is not limited to this. For example, it may be possible to determine that the human body M has moved when three or more detection beams b are blocked. In this case, the number of times the infrared detection signal exceeds the reference value VTH is larger than the above. It is also necessary to increase the reference number of times for distinguishing the long and short off-delay times TL and TS. The present invention also provides a time T for counting the number of times an infrared detection signal having an output level higher than a certain reference value VTH is output,
Specific time values such as the off-delay times TL and TS may be determined in consideration of the conditions of the detection area A, the moving speed v of the human body M, and various other conditions, and the above-described embodiment is not always necessary. It is not limited to a numerical value such as.

[0024]

As can be understood from the above description, according to the infrared type human body detection apparatus of the present invention, a short off-delay time is applied when the human body moves largely and leaves the detection area. Therefore, the human body detection signal is not output continuously for a long time after the exit,
While it is possible to prevent unnecessary equipment such as lighting equipment from being turned on unnecessarily, a long off-delay time is applied when there is little movement of the human body in the detection area, and the human body detection signal The output is prevented from being stopped in a short time, and it is possible to eliminate the problem that a desired device such as a lighting device is unjustly turned off despite the presence of a human body, which is very convenient. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a hardware configuration of an infrared human body detection device according to the present invention.

2A and 2B show an example of a condenser lens applied to an infrared human body detection device according to the present invention, FIG. 2A is a plan view, and FIG.

FIG. 3 shows an example of an infrared detection element applied to an infrared human body detection device according to the present invention, (a) is a plan view,
(B) is a sectional view.

FIG. 4 shows an example of a detection region formed by an infrared human body detection device according to the present invention, (a) is a plan view,
(B) is a side sectional view.

5 is an explanatory diagram showing an output waveform of an infrared detection signal when one detection beam in the detection area shown in FIG. 4 is blocked at a low speed.

6 is an explanatory diagram showing an output waveform of an infrared detection signal when one detection beam in the detection area shown in FIG. 4 is blocked at high speed.

7 is an explanatory diagram showing an output waveform of an infrared detection signal when two detection beams in the detection area shown in FIG. 4 are blocked at a low speed.

8 is an explanatory diagram showing an output waveform of an infrared detection signal when two detection beams in the detection area shown in FIG. 4 are blocked at high speed.

FIG. 9 is an explanatory diagram showing an example of a movement operation of a human body.

10 is a time chart showing a signal processing state during a moving operation of the human body M shown in FIG.

[Explanation of symbols]

 1 Condensing Lens 2 Optical Filter 3 Infrared Detector 4 Signal Amplifier 5 Bandpass Filter 6 Signal Processor 7 Output Controller 30 Detector Surface A Detection Area b Detection Beam M Human Body K Infrared Human Body Detector

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // G01V 8/12 G08B 13/191 7323-5G

Claims (1)

[Claims] 1. A condenser lens for forming a constant detection area in which a plurality of detection beams are present, and an infrared detection signal having an output level corresponding to a change in infrared rays condensed through the condenser lens. And an infrared detection element for outputting, the infrared detection signal of an output level higher than a predetermined constant reference value is output from the infrared detection element, and when the human body detection is determined, the human body detection signal is An infrared human body detection device configured to continuously output for a preset off-delay time, wherein two kinds of long and short off-delay times are set as the off-delay time. , Counting the number of times the infrared detection signal having an output level higher than the predetermined reference value is output, and the counted number is a predetermined reference time within a predetermined constant time. When the number is equal to or more than the number, the human body detection signal is continuously output within the time width of the off delay time on the short time side, while when the count number is less than the reference number, the human body detection signal is output on the time width of the off delay time on the long time side. Infrared human body detection device, characterized in that it is provided with control means for controlling so as to output continuously.