JPH02187691A - Human body detector - Google Patents

Abstract

PURPOSE:To make adjustment of the detection sensitivity corresponding to a background temp. and to decrease the causes for malfunctions by using a common optical system for both a detecting sensor for reference and a human body detecting sensor in order to detect the background temp. within an intrusion monitor region. CONSTITUTION:The detecting sensor 3 for reference and the human body detecting sensor 2 detect the IR rays entering from the intrusion monitor region A via the common optical system B. The detecting sensor 2 for reference outputs the signal based on the difference between the background temp. and the radiation temp. of a moving object intruding in the intrusion monitor region A to a processing system 4 of a processing means 6. A control section 5 controls the processing system in accordance with the output of the detecting sensor 3 for reference. The adequate adjustment of the sensitivity of the human body detecting sensor 2 is possible in this way when the background temp. changes with seasons or direct sunlight, etc. The causes for the malfunctions are decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a human body detection device that detects intrusion of a human body based on changes in radiant temperature within an intrusion monitoring area.

[Conventional technology]

Detects the radiant temperature within the intrusion monitoring area using infrared light,
A human body detection device is known that detects the intrusion of a human body into an intrusion monitoring area based on a change in radiant temperature.

When trying to detect a human body using changes in radiant temperature, there are various factors that can cause malfunctions, such as external disturbances such as direct sunlight, or changes in background temperature depending on the location of the sensor or the season. For this purpose, various measures must be taken.

FIG. 3 is a diagram showing an example of a conventional infrared sensor that prevents this type of malfunction. In the case of such an infrared sensor 1, since a moving object such as a human body intrudes into each intrusion area monitored by the detection elements 1a and Ib with a time lag, the infrared sensor 1 Output a signal as shown in a).

On the other hand, since disturbances such as sunlight are simultaneously irradiated onto the monitoring areas of the detection elements 1a and lb, signals with different polarities are emitted from the detection elements la and lb, as shown in Fig. 4(b) and (C). They are output simultaneously, and as a result, both of them cancel each other out, resulting in a nearly zero-level signal, as shown in FIG. 4(d). Therefore, malfunctions can be prevented at least against disturbances not caused by moving objects such as sunlight.

There is also an example in which a temperature detection element such as a thermistor is attached to the detection sensor itself, and the output signal of the detection sensor is controlled based on the attached temperature detection element.

[Problem to be solved by the invention]

Conventional differential infrared sensors can remove the effects of ambient light, etc., but cannot compensate for changes in the output level of the infrared sensor itself due to changes in background temperature, and may vary depending on the sensor installation location or season. It was not possible to adjust the detection sensitivity accordingly.

In addition, in the latter case, where a temperature detection element is attached to the detection sensor itself, there is a gap between the temperature of the detection sensor itself and the actual radiant temperature within the intrusion monitoring area, and the increase in background temperature due to direct sunlight, etc. There were some problems that could not be addressed.

This invention was made in order to solve the problem mentioned above, and it is possible to adjust the detection sensitivity according to changes in the background temperature of the intrusion monitoring area due to the season, the installation location, or disturbance factors such as direct sunlight. The purpose is to obtain a human body detection device that can perform the following functions.

[Means to solve the problem]

The human body detection device of the present invention includes a human body detection sensor that detects the intrusion of a human body into the intrusion monitoring area by detecting a change in radiation temperature within the intrusion monitoring area, and a reference sensor that detects the background temperature within the intrusion monitoring area. A sensor, an optical system shared by the human body detection sensor and the reference detection sensor, and processing means for processing a detection signal of the human body detection sensor based on a background temperature detected by the reference detection sensor. It is characterized by

Further, according to the present invention, the intrusion monitoring area may be divided into a plurality of small areas, and a human body detection sensor and a reference detection sensor may be provided for each small area.

[For production]

The reference detection sensor detects the background temperature of the intrusion monitoring area through a common optical system with the human body detection sensor. The processing means corrects the output signal of the human body detection sensor based on the signal from the reference detection sensor.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure is a schematic configuration diagram showing an embodiment of the present invention. In the figure, A is an intrusion monitoring area, 2 is a human body detection sensor that detects a human body intruding into the intrusion monitoring area A, and 3 is an intrusion monitoring area. A is a reference detection sensor that detects the background temperature, and B is an optical system that is shared by the reference detection sensor 3 and the human body detection sensor 2. Further, 6 is a processing means for processing the detection signals from both the sensors 2 and 3, and this processing means 6 is connected to the processing system 4 for processing the signal from the human body line sensor 2 and the output of the reference detection sensor 3. and a control section 5 that controls the processing system 4 based on the above-mentioned information.

In this embodiment, a reflective mirror is used as the optical system B common to both the sensors 2 and 3, but the optical system may also be a lens system. The human body detection sensor 2 used here is a differential infrared sensor, and is composed of a pair of detection elements 2a and 2b as shown in the figure in order to output the difference between the background temperature and the radiation temperature of the moving object. has been done.

Next, the operation will be explained.

The reference detection sensor 3 and the human body detection sensor 2 capture infrared rays incident from the intrusion monitoring area A via a common optical system B. The reference detection sensor 3 outputs a signal based on the background temperature of the intrusion monitoring area A to the control unit 5 of the processing means 6, and the human body detection sensor 2 detects the difference between the background temperature and the radiant temperature of the moving object intruding into the intrusion monitoring area A. A signal based on the difference is output to the processing system 4 of the processing means 6. The control section 5 controls the processing system 4 based on the output of the reference detection sensor 3.

To explain with a more specific example, the processing system 4 has an amplification circuit that amplifies the output of the human body detection sensor 2, and the control section 5 amplifies the output of the reference detection sensor 3. Controls the amplification factor of the circuit.

As a result, when the background temperature changes due to the season or direct light, the sensitivity of the human body detection sensor 2 can be adjusted as appropriate. That is, when the background temperature rises during summer or the like and approaches the temperature of the human body, it has conventionally been impossible to avoid a decrease in the sensitivity of human body detection. However, in this embodiment, the background temperature can be detected by the reference detection sensor 3 through a common optical system with the human body detection sensor 2, so the gain of human body detection is increased by the control means according to the background temperature. be able to.

The human body detection sensor 2 inevitably has characteristics that change depending on the background temperature, so if the detection sensitivity is adjusted according to the background temperature as in this embodiment, the causes of malfunction will be reduced. Needless to say.

Next, Fig. 2 shows an example in which the area for monitoring human body intrusion is set in a fan shape, and this fan-shaped area is further divided into a plurality of human body intrusion monitoring areas A to enable monitoring over a wide range. It shows. In this example, each human body intrusion monitoring area A is further divided into four small areas A, ~A4. Therefore, the human body detection sensor 2 will be provided for each of these small areas A1 to A4, but the reference detection sensor 3 may be provided for each small bowl area A1 to A4, but as shown in the figure. One unit may be placed in each human body monitoring area A, as shown in FIG. In that case, for example, a divided mirror may be used as the optical system, and each human body monitoring area A may correspond to each divided area of the divided mirror.

〔Effect of the invention〕

According to the present invention, in order to detect the background temperature in the intrusion monitoring area, the optical system of the reference detection sensor and the optical system of the human body detection sensor are made common, and the processing means The detection signal of the human body detection sensor is processed by Therefore, according to the present invention, the human body detection sensitivity can be adjusted according to the background temperature, and malfunctions can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, and FIG.
The figure shows an example of the arrangement pattern of the human body intrusion monitoring area, FIG. 3 is a configuration diagram of a conventional human body detection sensor, and FIG. 4 is a diagram showing the output state of the conventional human body detection sensor. 2...Human body detection sensor, 3...Reference detection sensor. 4...processing system, 5-=control unit. 6... Processing means, A-... Intrusion monitoring area. B...Optical system. Figure 1

Claims (2)

[Claims] (1) A human body detection sensor that detects changes in radiation temperature within an intrusion monitoring area to detect intrusion of a human body into the area, a reference detection sensor that detects background temperature within the intrusion monitoring area, and a human body detection sensor that detects a background temperature within the intrusion monitoring area; A human body characterized by comprising an optical system shared by a detection sensor and a reference detection sensor, and processing means for processing a detection signal of the human body detection sensor based on a background temperature detected by the reference detection sensor. Detection device. (2) The human body detection device according to claim 1, wherein the intrusion monitoring area is divided into a plurality of small areas, and a human body detection sensor and a reference detection sensor are provided for each small area.