JPH0495323A - Human body detecting sensor - Google Patents

Abstract

PURPOSE:To prevent the failure of the operation of a human body detecting sensor by infrared radiation by using an air velocity sensor of high sensitivity. CONSTITUTION:An air velocity sensor 14 of high sensitivity hot wire type is used which is capable of detecting the flow and fluctuation of air. The output end of the air velocity sensor 14 is connected to the input end of an amplifier 16. The output end of the amplifier 16 is connected to one input end of a comparator 18. Also the output end of a reference voltage generating circuit 20 for generating reference voltage is connected to the other input end of the comparator 18. Further the output end of the comparator 18 is connected via a switching circuit 22 to an illuminating device 24 which includes illumination of e.g. a fluorescent lamp. Therefore the illuminating device 24 is turned on when a human body detecting sensor 12 detects the presence of a person near it, while when the human body detecting sensor 12 detects the absence of any person near it the illuminating device 24 is turned off, thereby discriminating between the presence and absence of human bodies.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a human body detection sensor, and in particular, it detects the presence or absence of a human body, for example, detects that a person has entered a room or toilet, and based on the detection. This invention relates to human body detection sensors used in lighting systems that switch lighting devices.

(Prior Art) Conventionally, this type of human body detection sensor has used a hot wire type infrared sensor. With this human body detection sensor,
A human body is detected by detecting infrared rays emitted from the human body using an infrared sensor.

(Problem to be solved by the invention) However, in this conventional human body detection sensor, since the infrared sensor is originally a sensor for detecting heat, it is necessary to use a filter to change the wavelength of incident light or to use dual Although some improvements can be made by changing the structure, malfunctions caused by infrared rays from outside light such as sunlight cannot be avoided.

Therefore, the main object of the present invention is to provide a human body detection sensor that is less likely to malfunction due to infrared rays.

(Means for Solving the Problems) The present invention is a human body detection sensor including a highly sensitive wind speed sensor.

(Function) A highly sensitive wind speed sensor detects, for example, air flow due to the opening and closing of a door, and air fluctuations due to human movement and breathing. Through this detection, a human body is detected. Therefore, this human body detection sensor almost never malfunctions due to infrared rays.

(Effects of the Invention) According to the present invention, a human body detection sensor that is less likely to malfunction due to infrared rays can be obtained.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

(Example) This invention relates to a human body detection sensor, and in the following examples, a lighting system using a human body detection sensor will be described.

FIG. 1 is a block diagram showing one embodiment of the present invention.

The lighting system 10 of this embodiment includes a human body detection sensor 12
including.

The human body detection sensor 12 includes a wind speed sensor 14.

As the wind speed sensor 14, a highly sensitive hot wire type sensor is used, which can detect, for example, air flow accompanying opening/closing of a door or fluctuations in air due to movement/breathing of a person.

The output end of this wind speed sensor 14 is connected to the input end of an amplifier 16 for amplifying the output signal of the wind speed sensor 14.

Furthermore, the output terminal of amplifier 16 is connected to one input terminal of comparator 18. Further, the other input terminal of the comparator 18 is connected to the output terminal of a reference voltage generation circuit 20 that generates a reference voltage.

The reference voltage of the reference voltage generation circuit 20 is approximately equal to the output signal from the amplifier 16 when the wind speed sensor 14 is not detecting air flow or air fluctuation, that is, when it is detecting that there is no person nearby. The voltages are set to the same magnitude. Therefore, a large voltage signal is obtained from the output end of the comparator 18 when the wind speed sensor 14 detects that there is a person nearby, and when the wind speed sensor 14 detects that there is no person nearby. A signal of approximately OV can be obtained when the

Further, the output terminal of the comparator 18 is connected to the switching circuit 22
A lighting device 2 including lighting, such as a fluorescent lamp, for example.
Connected to 4. In this case, the switching circuit 22 is
The lighting device 24 is turned on when a large voltage signal is input to its input terminal, and the input terminal has approximately OV voltage.
The lighting device 24 is configured to be turned off when the signal is input.

In this lighting system 10, in particular, a human body detection sensor 12 and a lighting device 24 are respectively attached to a wall and a ceiling of a room, for example.

In this lighting system 10, when a person opens the door to enter the room where the lighting system 10 is installed, the wind speed sensor 14 of the human body detection sensor 12 activates, as shown in FIG.
It detects the air flow occurring in the room, i.e. the presence of a person nearby, which turns on the lighting device 24.

Furthermore, when a person enters the room, the wind speed sensor 14
Detects changes in the air caused by people's movement and breathing,
In other words, it detects that there is a person nearby, and the lighting device 24
remains on.

Then, when the person leaves the room and closes the door, the wind speed sensor 14 detects no air flow or fluctuation in the room, i.e., the person is no longer nearby, and the lighting device 24 turns off. Become.

In this way, in this lighting system 10, the lighting device 24 is turned on when the human body detection sensor 12 detects that there is a person nearby, and when the human body detection sensor 12 detects that there is no person nearby. The lighting device 24 is turned off when the user is in the room.

This lighting system 10 does not detect heat or infrared rays to detect a human body, so there are fewer malfunctions caused by infrared rays. Therefore, this lighting system 10 is highly effective if used in a place where hot-ray type infrared sensors are likely to malfunction, such as a room that is easily affected by strong light rays such as sunlight.

Also, wind speed sensors are cheaper than infrared sensors, so
This lighting system 10 or human body detection sensor 12 can be manufactured at a lower cost than one using an infrared sensor.

FIG. 3 is a block diagram showing another embodiment of the invention. In the illumination system 10 of this embodiment, a wind speed sensor 14 and an infrared sensor 26 are particularly used as the human body detection sensor 12.

In this embodiment, the output end of the wind speed sensor 14 is connected to one input end of an AND circuit 30 via the wind speed sensor signal processing circuit 28. This wind speed sensor signal processing circuit 28
is for processing the output signal of the wind speed sensor 14 into a substantially OV signal when the wind speed sensor 14 is not detecting air flow or air fluctuation. This wind speed sensor signal processing circuit 28 is, for example, the amplifier 16 in the embodiment shown in FIG. A comparator 18 and a reference voltage generation circuit 20 may be used.

Further, the infrared sensor 26 is connected to the other input terminal of the AND circuit 30 via the infrared sensor signal processing circuit 32. This infrared sensor signal processing circuit 32 converts the output signal of the infrared sensor 26 into an approximately OV signal when the infrared sensor 26 is not detecting the heat of the human body, that is, when it is detecting that there is no person nearby. It is for processing. As this infrared sensor signal processing circuit 32, for example, a circuit having a circuit configuration similar to that of the wind speed sensor signal processing circuit 28 described above may be used.

Therefore, in this embodiment, when the wind speed sensor 14 and the infrared sensor 26 detect that there is a person nearby, a large voltage output is obtained from the output terminal of the AND circuit 30, and the wind speed sensor 14 and the infrared sensor 26 detects that there is no person nearby, an output of approximately OV is obtained from the output terminal of the AND circuit 30.

Further, the output terminal of the AND circuit 30 is connected to the switching circuit 2
2, it is connected to a lighting device 24.

Therefore, in this embodiment, when the wind speed sensor 14 and the infrared sensor 26 detect that there is a person nearby, the lighting device 24 is turned on, and at least one of the wind speed sensor 14 and the infrared sensor 26 detects that there is a person nearby. The lighting device 24 is turned off when detecting the absence of a person.

Therefore, in this embodiment, the wind speed sensor can be used even when the wind speed sensor alone would malfunction due to the introduction of outside air into the room or the use of a ventilation fan, or when the infrared sensor alone would malfunction due to infrared rays from outside light such as sunlight. 1
4. As shown in FIG. 4 as a timing diagram showing an example of the operation of the infrared sensor 26 and the lighting device 24, they operate normally.

In addition, although the above-mentioned each Example demonstrated the lighting system using a human body detection sensor, the human body detection sensor concerning this invention can be used for systems other than a lighting system.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a timing chart showing an example of the operation of the wind speed sensor and lighting device in the embodiment shown in FIG. FIG. 3 is a block diagram showing another embodiment of the invention. FIG. 4 is a timing chart showing an example of the operation of the wind speed sensor, infrared sensor, and lighting device in the embodiment shown in FIG. 3. 10 is a lighting system, 12 is a human body detection sensor, 14 is a wind speed sensor, 16 is an amplifier, 18 is a comparator, 20 is a reference voltage generation circuit, 22 is a switching circuit, 24 is a lighting device,
26 is an infrared sensor, 28 is a wind speed sensor signal processing circuit,
30 is an AJJD circuit, and 32 is an infrared sensor signal processing circuit. Patent applicant Murata Manufacturing Co., Ltd. Representative Patent attorney Oka 1) Kei Zen Figure 1 Figure 1

Claims (1)

[Claims] Human body detection sensors, including highly sensitive wind speed sensors.