JPH05322649A - Human body detector - Google Patents

Abstract

PURPOSE:To obtain a human body detector which can be simplified in structure and downsized and yet can decide movement and moving direction of human body easily and accurately. CONSTITUTION:An infrared ray detecting element 1 comprises a plurality of detecting element faces 17a-17d and a detected signal output means whereas a condenser comprises a Fresnel lens array 2 formed into a dome and a field of view limiting means 3. The field of view limiting means 3 limits the field of view of each of the detecting element faces 17a-17d so that an infrared ray detecting region formed through the Fresnel lens array 2 is divided into a plurality of regions A-D and different infrared ray detecting regions are constituted for the plurality of detecting element faces 17a-17d of the infrared ray detecting element 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a human body detecting device for detecting infrared rays emitted from a human body, and more specifically, it is installed on a ceiling surface of a room or the like, and various equipments such as indoor lighting and air conditioning depending on the presence or absence of human body detection. The present invention relates to a human body detection device applied to applications such as turning on and off.

[0002]

2. Description of the Related Art The basic principle of this type of human body detecting device is to detect infrared rays emitted from the human body, particularly far infrared rays, by an infrared ray detecting element, and use this as a change in the temperature difference from the background of the detection visual field. It grasps and judges that the human body exists. Even if the infrared ray detecting element is made to detect infrared rays, the amount of information is insufficient and the presence of the human body cannot be surely detected. For example, when the movement of the human body stops within the detection area, it is no longer recognized that the human body is still present, and when the human body detection device is used as an automatic lighting control switch,
Even if the human body is present in the room, there is a problem that the lighting is turned off.

In order to reliably detect the presence of a human body, it is desirable to increase the amount of information for infrared detection so that the presence or absence of movement of the human body within the detection area and its direction can be detected at the same time. Therefore, conventionally, as a means for increasing the information amount of infrared detection, by using a plurality of independent infrared detection elements, each of the infrared detection elements to detect the infrared rays emitted from the human body, each infrared detection There has also been proposed a device in which it is determined whether or not an object that has entered the detection area is a human body by determining the timing of infrared detection and the output state of the element.

[0004]

However, in the conventional means using a plurality of infrared detecting elements which are independent of each other, it is necessary to provide various control circuits and a condenser for each infrared detecting element. However, there is a problem in that the construction becomes complicated and large, and the manufacturing cost becomes high.
Further, conventionally, even when the movement of the human body and the moving direction thereof are arithmetically processed based on the infrared detection signal, those infrared detection signals are output from infrared detection elements independent of each other. , Its signal processing is troublesome,
It was easy to make an error judgment.

The present invention has been proposed in view of the above points, and has a simplified structure and a reduced size, and can detect a human body in which the movement of the human body and its moving direction can be easily and accurately determined. The purpose is to provide a device.

[0006]

SUMMARY OF THE INVENTION A human body detecting apparatus according to the present invention as set forth in claim 1 proposed for achieving the above object is an infrared ray detecting element by collecting infrared rays emitted from a human body by a condenser. In the human body detection device for detecting a predetermined detection signal and outputting the predetermined detection signal, the infrared detection element has a plurality of detection element surfaces and detection signal output means, and the condenser is a dome-shaped Fresnel. A lens array,
The dome-shaped Fresnel lens array is provided inside the field-of-view limiting means, and the field-of-view limiting means is
The infrared detection area formed via the Fresnel lens array is divided into a plurality of areas, and the infrared detection areas are formed so as to form different infrared detection areas for each of the plurality of detection element surfaces of the infrared detection element. ing.

According to a second aspect of the present invention, there is provided the human body detection device according to the first aspect, wherein the visual field limiting means is a mirror that reflects infrared rays transmitted through the Fresnel lens of the Fresnel lens array. It was done.

According to a third aspect of the present invention, in the human body detection device according to the second aspect, the mirror of the field-of-view limiting means is provided between the front space portions of the plurality of detection element surfaces of the infrared detection element. It is provided so as to partition.

[0009]

In the human body detecting apparatus according to the present invention having the above-mentioned structure, the field of view of the infrared detecting element is limited by the visual field limiting means so that each detecting element surface of the infrared detecting element is different. Since infrared rays are detected in different areas, it is possible to increase the amount of information by causing infrared rays to be detected in a plurality of detection areas despite the use of one infrared detection element. That is, when a human body exists in the detection area corresponding to any one of the plurality of detection element surfaces, for example, when the human body moves to another detection area, the human body on the previous detection element surface At the same time as the detection is stopped, the human body detection will be performed on the surface of another detection element.
It becomes possible to determine the movement of the human body and the movement direction thereof. According to the dome-shaped Fresnel lens array provided with a plurality of Fresnel lenses, infrared rays are condensed by any of the corresponding Fresnel lenses on any of the detection element surfaces to perform human body detection with high sensitivity. It is not necessary to provide a condenser lens for each of the plurality of sensing element surfaces one by one.

In the human body detecting apparatus according to the present invention as set forth in claim 2, since the field-of-view limiting means is composed of a mirror that reflects infrared rays, the infrared rays passing through the Fresnel lens are the detecting elements of the infrared ray detecting elements. Even when the light is incident at an angle different from the angle at which the light is directly condensed on the surface, it is possible to receive the light on the detection element surface by the reflection of the mirror. Therefore, the number of detection beams that can be focused on the detection element surface by one Fresnel lens can be doubled.

In the human body detecting apparatus according to the present invention as defined in claim 3, since the space portions on the front sides of the plurality of detection element surfaces are partitioned by the mirror, the detection beams are generated between different detection areas. It is possible to reliably prevent the intersection, and it is possible to accurately detect the movement of the human body between the different detection areas.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a human body detection device according to the present invention, FIG. 2 is an exploded perspective view of its essential parts, FIG. 3 is a bottom view of its essential parts,
FIG. 4 is a half-cut sectional view of an essential part, FIG. 5 is a sectional view showing the structure of the infrared detecting element, FIG. 6 is a plan view of the essential part, and FIG. 7 is a circuit diagram of the infrared detecting element.

The human body detection apparatus shown in FIG. 1 detects an infrared ray emitted from a human body and outputs a detection signal, an infrared detecting element 1, a dome-shaped Fresnel lens array 2 as a condenser, and a limited field of view. Mirror 3, as a means
In addition, a circuit block 4 for amplifying and processing the detection signal output from the infrared detection element 1 is provided. Each of these parts is properly accommodated in a housing case 5 formed by a base 5a and a main body cover 5b which are attached to the ceiling surface T in the room, and the Fresnel lens array 2 is provided on the lower surface side of the housing case 5. Open window 5
It projects downward from c. In the figure, 6 is a screw for mounting on the ceiling surface T, 7 is a wire used for supplying electric power to the human body detection device and for transmitting a signal to a lighting fixture or the like which is an ON / OFF control target. is there.

Of the above-mentioned respective parts, as the infrared detecting element 1, for example, a pyroelectric type is applied. However, when the infrared ray emitted from the human body receives light rays in the wavelength band of the infrared ray, the voltage or Any type can be applied as long as the resistance value and the like can be changed and can be detected. As a specific structure of the infrared detection element 1, for example, as shown in FIG. 5, in a shield case 12 formed by a case cover 12a having an opening window 10 formed in the upper part and provided with an infrared transmission filter 11 and a base 12b. In addition, a semiconductor chip 14 for infrared detection connected to the plurality of terminals 13 is provided. As shown in FIG.
As shown in FIG. 4, the four sensing element surfaces 17 (17a to 17d) functioning as infrared ray receiving sections, and the temperature compensating section 15
a to 15d are provided. This temperature compensation unit 15a-
Reference numeral 15d is for preventing the generation of an output due to a rapid change in ambient temperature, and is provided corresponding to each of the sensing element surfaces 17a to 17d, but is not visible from the outside through the opening window 10. Set to the position.

The above-mentioned four sensing element surfaces 17a to 17d
Are connected to each other via the narrow connecting portions 16 ... And have a circuit configuration as shown in FIG. That is, as shown in the figure, the infrared detection element 1 has four detection element surfaces 17
When infrared rays are detected by each of a to 17d, the detection signal is amplified by the amplifying FET and output from each terminal of S1 to S4. FET drain D
And the terminal G for ground are shared.

FIG. 8 shows a hardware configuration of the circuit section 4 for processing the infrared detection signal output from the infrared detection element 1. As shown in the figure, the infrared detection element 1
The four types of detection signals output by the detection of infrared rays on the four detection element surfaces 17a to 17d are amplified by the FETs, respectively, and then the individual bandpass filters 4
It is input to the arithmetic circuit 42 via 0 and the level detection circuit 41. The arithmetic circuit 42 is configured to count the order of occurrence of each input, the interval, and the lapse of time, drive the output control circuit 43 based on a predetermined algorithm, and control the relay output circuit 44. There is. In addition to the movement of the human body and its direction, as a countermeasure against the popcorn noise phenomenon due to a sudden change in ambient temperature, which is a problem peculiar to the pyroelectric element, a careless operation is provided by providing a pulse counter function in the arithmetic circuit 42. It is also possible to configure so as to prevent.

The dome-shaped Fresnel lens array 2 shown in FIG. 1 is made of polyethylene resin or the like that transmits infrared rays, and has a large number of Fresnel lenses 20 for condensing infrared rays formed on its peripheral surface. Fresnel lens 2
As a specific mode of 0 ..., For example, as shown in FIGS. 2 and 3, the Fresnel lens array 2 is divided into an outer peripheral portion 2A and an inner peripheral portion 2B, and one of the outer peripheral portions 2A is Has 12 Fresnel lenses 20 (20A) formed at equal intervals in total, and the Fresnel lens 20 (20A) is formed on the other inner peripheral portion 2B.
(20B) are formed at eight places at equal intervals. The part indicated by "+" in the figure is the center of each Fresnel lens 20.

The focus of each of these Fresnel lenses 20 is set at the center of curvature of the dome-shaped Fresnel lens array 2, but strictly speaking, it is set at the positions of the four detection element surfaces 17a to 17d of the infrared detection element 1. It That is, in this embodiment, as will be described later, the detection area is divided into four areas A to D (see FIG. 3), and, for example, the respective focal points of the Fresnel lens 20 ... In each case, the focal points of the Fresnel lens 20 ... At the position corresponding to the area B on the detection element surface 17a are the focal points of the Fresnel lens 20 ... At the position corresponding to the areas C and D. The positions are set to the positions of the sensing element surfaces 17c and 17d.

The focal length of each Fresnel lens 20 ... Is 17 mm, the light receiving area on the detection element surfaces 17a to 17d is 1 mm square, and the height from the floor surface to the ceiling surface is 2700 m.
When m, the projection pattern of the detection beam in the direction of 40 degrees on the floor surface is calculated as 2700 / cos 40 ° ≈3525 3525/17 = 207, and the diameter of the dome-shaped Fresnel lens array 2 is about 200 mm. Therefore, the size can be made suitable for indoor installation.

The mirror 3 as the field limiting means is provided inside the Fresnel lens array 2 and in a state of being close to the opening window 10 of the infrared detecting element 1, and the respective visual fields of the four detecting element surfaces 17a to 17d. By limiting
The infrared detection area on the detection element surfaces 17a to 17d is set to A
It has a function of being divided into four areas of ~ D. In this mirror 3, for example, the light rays transmitted through the Fresnel lens 20 corresponding to the area A in FIG. 3 and condensed are received by the detection element surfaces 17b to 17d corresponding to the other areas B to D. It is provided so as to partition the space portions on the front side of the four detection element surfaces 17a to 17d of the infrared detection element 1 so that the detection element surface 17a corresponding to the area A can be properly received. There is.

Next, a usage example of the human body detecting device having the above-mentioned structure,
And the operation will be described. First, when the human body detecting device is attached to the ceiling surface T in the room as shown in FIG. 1, when a human body is present below the human body detecting device, far infrared rays emitted from the human body are collected through the Fresnel lens 20 and detected. It will be detected on any of the element surfaces 17a to 17d. At that time, for example, as shown in FIG. 4, except for the optical axis K that is condensed by the Fresnel lens 20 and directly received by the detection element surface 17, it is incident at a different angle and reflected by the mirror 3. There is also an optical axis K1 that is received by the sensing element surface 17. Therefore, the total number of human body detection beams can be increased to a number larger than the total number of Fresnel lenses 20. In the case of this embodiment, for example, as shown in FIG. 9, the total number of points P (detection beams) capable of detecting a human body can be set to 36. As a result, due to the increase in the number of points at which the human body can be detected, the interval between the detection beams can be narrowed, and precise human body detection can be performed.

FIG. 9 shows an example applied to a room of 8 tatami mats. For example, when it is applied to a room of 12 tatami mats wider than that, as shown in FIG. The angle may be rotated by 45 degrees with respect to the case shown in FIG. 9 so that the entire room can be detected.

Next, when detecting infrared rays, the mirror 3 is used.
Since the field of view of each of the detection element surfaces 17a to 17d is limited by the detection element surface 17a to 17d, for example, when a human body exists in the detection area A, the human body detection is performed on the detection element surface 17a, and similarly, the detection area B to When a human body exists in each of D, the human body is detected on each of the detection element surfaces 17b to 17d. Eventually, these four detection element surfaces 17a to 17d output their own detection signals by performing human body detection in their own detection areas. Therefore, in the arithmetic circuit 42 shown in FIG. 8, for example, when a human body detection signal in the detection area A is received from the detection element surface 17a and then a human body detection signal in the detection area B is received from another detection element surface 17b. In this case, it can be determined that the human body has moved from the area A to the area B, and the accuracy of the human body detection determination can be increased by the amount of the information amount of the human body presence determination increased.

FIG. 11 shows an example of the case where the human body detection processing judgment is performed. As shown in FIG.
In the case where the detection signal is output in any one of the areas D to D, those signals are continuously output within a predetermined fixed time, and the time interval between the signals (T1 in the same figure.
As long as T4) is equal to or less than a predetermined fixed time, it can be determined that a human body exists in the room. Therefore, in such a case, at the initial stage, the relay output circuit 44 may output a signal for operating a predetermined control device such as a lighting fixture in the room.

FIG. 12 shows an example of processing determination different from the above, in which the detection signal is not continuously output in any of the areas A to D, and moreover, it is constant from the time of the signal S finally output. If there is no continuous output of the detection signal until the time T elapses, it can be determined that the person has left the room. Therefore, the relay output circuit 44 may output a signal for turning off the lighting fixture or the like at that time. Although the simplest control example is described in FIGS. 11 and 12 for convenience of description, it is possible to perform high-precision human body detection in consideration of movement between the detection areas A to D in the signal processing.

[0026]

As can be understood from the above description, according to the human body detecting apparatus of the present invention as set forth in claims 1 to 3,
Being able to detect the human body in consideration of the detection area, it is possible to properly determine the state of movement and presence other than the passage of the human body, and to perform proper use as a control switch for lighting equipment etc. to prevent malfunction. Needless to say, since the human body can be detected in a plurality of independent detection areas by using one infrared detection element, the concentrator has a plurality of infrared detection elements as compared with the conventional means using a plurality of infrared detection elements. It is not necessary to provide them individually, and it is possible to simplify the overall structure of the device, downsize it, and finish it in a good appearance, and at the same time, it is possible to reduce the manufacturing cost. can get. Further, since the detection signal for each of the plurality of detection areas is output from one infrared detection element, it is convenient because the integration processing of the plurality of detection signals can be easily performed. Further, in the present invention, since the detection area is divided into a plurality of areas by using the Fresnel lens array and the field-of-view limiting means, there is no waste such that the detection areas overlap each other, and the efficiency can be improved in a wide area. There is also an advantage that good human body detection can be performed.

In particular, according to the human body detecting apparatus of the present invention as set forth in claim 2, when the infrared rays transmitted through the Fresnel lens are incident at an angle different from the angle at which the infrared rays are directly condensed on the detecting element surface. Even if there is, it is possible to receive the light on the detection element surface by the reflection of the mirror, so even if a Fresnel lens array with a small number of lenses is used, it is possible to configure the detection area with a more precise detection beam. The detection sensitivity of can be improved.

According to the human body detecting apparatus of the third aspect of the present invention, it is possible to reliably prevent the detection beams from crossing between different detection areas by the mirror, and to move the human body between the different detection areas. Can be accurately detected.

[Brief description of drawings]

FIG. 1 is an overall sectional view showing an embodiment of a human body detecting device according to the present invention.

FIG. 2 is an exploded perspective view showing an example of a member constituting a main part for performing infrared detection.

FIG. 3 is a plan view showing a structure of a main part for performing infrared detection.

FIG. 4 is a half-cut sectional view showing a structure of a main part for performing infrared detection.

FIG. 5 is a sectional view showing an example of an infrared detection element.

FIG. 6 is a plan view showing an example of a pattern state of a semiconductor chip of an infrared detection element.

FIG. 7 is an explanatory diagram showing an example of a circuit configuration of an infrared detection element.

FIG. 8 is a block diagram showing an example of a processing circuit of a signal output from an infrared detection element.

FIG. 9A is a plan view showing an example of a human body detection area,
(B) is the side view.

FIG. 10 is a plan view showing another example of a human body detection area.

FIG. 11 is a time chart showing an example of an output state of an infrared detection signal.

FIG. 12 is a time chart showing another example of the output state of the infrared detection signal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Infrared detection element 2 Fresnel lens array 3 Mirror (field-of-view limiting means) 10 Opening window 11 Infrared transmission filter 14 Semiconductor chip 15a-15d Temperature compensation part 17a-17d Detection element surface 20 Fresnel lens A-D infrared detection area

Claims (3)

[Claims] 1. A human body detection device which collects infrared rays emitted from a human body by a condenser and detects the infrared rays with an infrared detection element and outputs a predetermined detection signal, wherein the infrared detection element has a plurality of detection element surfaces and a detection element. The concentrator includes a dome-shaped Fresnel lens array and a field-of-view limiting unit provided inside the dome-shaped Fresnel lens array. Limits the field of view of each sensing element surface so that the infrared sensing area formed via the Fresnel lens array is divided into a plurality of infrared sensing areas to form different infrared sensing areas for each sensing element surface. A human body detection device, which is provided. 2. The field-of-view limiting means according to claim 1,
A human body detection device that is configured by a mirror that reflects infrared rays that have passed through the Fresnel lens array. 3. The human body detection device according to claim 2, wherein the mirror of the visual field limiting means is provided so as to partition the front space portions of the plurality of detection element surfaces of the infrared detection element.