JP2543049Y2 - Infrared moving object detection device - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to the amount of infrared energy radiated from an object such as a moving human body and the amount of infrared energy radiated from a background such as a floor of a building. The present invention relates to an infrared moving object detection device that detects a difference and controls opening and closing of an automatic door and operation of a security alarm device.

<Conventional technology> Every object above the absolute temperature (-273 ° C) emits infrared rays according to its temperature, and human bodies and buildings at room temperature emit far-infrared rays having a peak wavelength around 10 µm. ing. An infrared moving object detection device utilizing such a phenomenon sets a predetermined detection area on a floor surface of a building or the like,
Infrared light emitted from this detection area is condensed by an optical device such as a condenser lens in an infrared detector and made incident on an infrared detection element, and infrared energy generated by a moving object such as a human body entering the detection area. The change in the amount is detected by an electric signal output from the infrared detection element,
When the amplified signal of the electric signal exceeds a predetermined level, a trigger signal is output, a detection signal of a visitor is issued, or an oscillating signal of a security alarm device is issued, and an automatic door is opened and closed. It is widely used as a start switch for operating a security alarm device.

<Problems to be Solved by the Invention> By the way, in the related art, a device that detects invasion of a human body in a relatively large space such as a room by using only one infrared moving object detection device is used for crime prevention or the like. However, when an object having a temperature difference with respect to the background such as the floor surface of the detection area, for example, a small animal such as a dog or a cat other than the human body enters the detection area, the detection sensitivity is almost the same for all. And the detection level line is constant, a trigger signal is also output to a small animal, and a malfunction occurs. In such a case, in the automatic opening / closing door, the door is opened and a small animal enters.On the other hand, in the security alarm device, an alarm is issued each time a small animal that does not participate in a crime even if it intrudes. It is emitted, which is extremely inconvenient.

<Purpose of the Invention> The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an infrared-type moving object detection device capable of reliably preventing erroneous detection of small animals other than a human body. Aim.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides an infrared ray that outputs an electric signal corresponding to the amount of fluctuation of infrared ray incident from a predetermined detection area and incident through an optical system. Having three or more sensing elements, and each of these infrared sensing elements,
The three or more infrared detection elements are arranged in a vertical direction on the floor so that one human body walking on the floor of the detection area can be simultaneously detected. Is characterized by having a human body discriminating circuit composed of digital logic operation means for discriminating that the above-mentioned fluctuation amount exceeds a predetermined level.

In the present invention, the “majority” is, of course, an integer value that does not include the half and exceeds the half. For example, when the number of elements is 3, it is 2 or 3, and when the number of elements is 4, 3
Or 4, when the number of elements is 5, it is 3, 4 or 5. The reason for requiring a `` majority '' is that even if a part of the human body to be detected is hidden by an obstacle or a part of the human body is covered with a poorly-heated conductor such as a bulletproof vest, a false alarm will be issued. This is to determine that the subject is a human body. The reason why it is not determined that the object is a human body in the case of “half or less” is that a moving object such as a small animal is not erroneously detected.

<Operation> Each of the three or more infrared detection elements sets a corresponding detection area. In other words, the predetermined detection area is divided by the number of infrared detection elements. When a human body enters the detection area, at least a majority of all the infrared detection elements simultaneously sense and respond, and an electric signal is output at the same time. The electric signal output at the same time is input to the human body discriminating circuit, and the human body discriminating circuit uses the electric signal from the majority of the infrared detecting elements,
Outputs a human body detection signal.

On the other hand, when a small animal that is significantly shorter than the human body enters the detection area, it only crosses a single detection area in each detection area of each infrared detection element, or at most less than a majority of the detection area. Therefore, only less than the majority of all the infrared detecting elements sense and respond, and no human body detection signal is output from the human body determination circuit. Thereby, an erroneous detection operation by a small animal can be reliably prevented. In addition, in general, the provision of means to prevent malfunctions caused by small animals necessarily increases the risk of false alarms due to omissions in the detection of the human body. Is a majority, a human body detection signal is output, so that a false alarm can be reliably prevented.

<Embodiment> Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a schematic electric circuit of one embodiment of the present invention,
In order to simplify the description, the case where three infrared detecting elements are used is illustrated.

As shown in FIG. 2, each of the infrared detecting elements S1 to S3 has a different detection area E1 to E3 according to the respective detection visual field, and walks on the floor of the three types of detection areas E1 to E3.
In order to be able to detect individual human bodies at the same time, they are arranged corresponding to the vertical direction on the floor surface, and each infrared detecting element S1 to S3 has an optical system such as a Fresnel lens or a concave reflecting mirror. (Not shown). These infrared detecting elements S1 to S3 are configured to output an electric signal corresponding to the amount of fluctuation of the infrared incident light emitted from the detection area and incident through the optical system, and the amount of the fluctuation is a predetermined threshold level. Is exceeded, for example, "1" is output; otherwise, "0" is output. Amplifying circuits A1 to A3 for amplifying the output electric signals of the infrared detecting elements S1 to S3 are provided.
An electric signal is input via .about.A3, and a human body discriminating circuit HS is provided for discriminating that a variation amount of a majority of these infrared detecting elements has exceeded a predetermined level. In the human body discriminating circuit HS, three OR gates OR1 to OR3, each having two input terminals connected to outputs of different amplifying circuits A1 to A3, and outputs of the OR gates OR1 to OR3, respectively, are input. And a digital logic circuit group of three-input AND gate AND. The output circuit is 3
The output of the input and gate AND is a resistor R for base bias.
NPN transistor Q input to the base electrode via
The detection signal is output from the output terminal O of the collector of the transistor Q.

 Next, the operation of the above embodiment will be described.

When the human body H enters the detection areas E1 to E3 and moves from the solid line position in FIG. 2 to the two-dot chain line position, two or more infrared detection elements S1 to S3 always respond at the same time. In addition,
The term “simultaneous” here includes a range of about 1 second due to an operation delay of the infrared detecting elements S1 to S3 and the like. Human body identification circuit HS
Has a circuit configuration in which any two OR gates OR1 to OR3 are driven by the sensing outputs of the single infrared detecting elements S1 to S3 to output a high level signal, and at least two infrared detecting elements S1 ~ S3, that is, the sensing signals are simultaneously output from a majority of the three infrared detecting elements S1 to S3, so that all three OR gates OR1 to OR3 are driven to output high level signals, and The logical product of the three-input AND gate AND is taken and the transistor Q of the output circuit is obtained.
Is turned on, and a detection signal is output from the output terminal O. Accordingly, the majority of the infrared detecting elements S1 to S3 simultaneously sense and respond to the human body H that has entered the detection areas E1 to E3, so that the human body H can be reliably detected.

On the other hand, when the small animal A enters the detection areas E1 to E3, as is apparent from FIG. 2, only one of the single infrared detection elements S1 to S3 senses and responds to the movement. Therefore, any two OR gates OR1 to OR3 in the human body discriminating circuit HS only drive and output a high-level signal, and the logical product of the three-input AND gate AND is not obtained.
No detection signal is output.

As described above, the human body discriminating circuit HS is constituted by a digital logic circuit, and the signal input to this human body discriminating circuit HS is a digital signal of ON or OFF detected in three or more independent detection areas. is there. This is a configuration in which the detection state from each of these independent detection areas is only digitally logically operated, and in this logical operation, complicated arithmetic calculation is unnecessary, and it is also necessary to add conditions based on the positional relationship of the infrared detection elements. Absent. The miniaturization can be realized by the processing circuit having such a simple configuration. Further, even when a microcomputer is used, an A / D converter can be dispensed with, and a low-cost microcomputer can be used sufficiently. In this embodiment, the configuration of three infrared detecting elements is applied. However, the number of infrared detecting elements is not limited to three, and when the number is further increased, signal processing can be easily performed by digital logic operation as described above. However, there is no difficulty in such measures, and the reliability against false reports and unreported reports can be improved.

<Effects of the Invention> As described above, according to the infrared moving object detection device of the present invention, the infrared detection element that outputs an electric signal according to the amount of fluctuation of the infrared incident light incident from the predetermined detection area is provided. It has three or more, and each of these infrared detecting elements is arranged corresponding to the up and down direction on the floor surface so as to be able to simultaneously detect one human body walking on the floor surface of the detection area. Since a human body discriminating circuit including digital logic operation means for discriminating that the variation amount of a majority of the three or more infrared detecting elements has exceeded a predetermined level is provided, A majority of the infrared detectors simultaneously sense and respond only when entering the detection area, whereas a majority of the infrared detectors simultaneously detect and respond when a small animal that is significantly shorter than the human body enters the detection area. Since no answer is given, erroneous detection of small animals can be reliably prevented, and no false alarm occurs.

Furthermore, in the digital logic operation in the human body discriminating circuit, there is no need to add a condition based on the positional relationship of the infrared detecting element, and the configuration is extremely simple, and complicated arithmetic calculation is not required. Can be realized. Furthermore, when the number of infrared detecting elements to be installed is increased, the reliability against false alarms and false alarms can be further improved. In this case, signal processing can be easily performed by the above-described digital logic operation. Can be easily handled.

[Brief description of the drawings]

FIG. 1 is an electrical connection diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing an arrangement of a detection area by the infrared detecting element of FIG. S1 ~ S3 …… Infrared detector HS …… Human body identification circuit

Claims (1)

(57) [Scope of request for utility model registration] 1. An infrared detecting device comprising: three or more infrared detecting elements for outputting an electric signal corresponding to a variation of incident infrared light emitted from a predetermined detecting area and incident through an optical system; Are arranged corresponding to the vertical direction on the floor surface so that one human body walking on the floor surface of the detection area can be simultaneously detected, and a majority of the three or more infrared detection elements An infrared moving object detection device comprising a human body discriminating circuit comprising digital logic operation means for discriminating that the variation of the element has exceeded a predetermined level.