JP3240457B2 - Human body detection lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens for detecting a human body, and more particularly, to detecting an infrared ray emitted from a human body by an infrared detecting element, detecting movement and slight movement of a human, and controlling equipment such as lighting. The present invention relates to an improvement of an infrared condensing lens of an infrared human body detecting device.

[0002]

2. Description of the Related Art As elements used in a human body detecting device and detecting the amount of change in infrared rays emitted from a human body, those generally called pyroelectric elements occupy most. A human body detection device using this pyroelectric element is rapidly spreading for automatic control of lighting equipment and the like in addition to an intrusion detection device for crime prevention.

In such an infrared type human body detecting device, infrared rays collected by a light collecting section are detected by an infrared detecting element, the detection signal is amplified by an amplifier section, and unnecessary frequency components are removed by a bandpass filter. After that, the detection signal amplified by the comparison circuit is compared with a predetermined threshold value, and when the detection signal is larger than the threshold value, the detection signal is output from the output circuit.

[0004] A lens or a mirror is used for the light collecting section,
Such a condensing optical system forms a detection field of view having the same shape as the light receiving surface of the infrared detection element, that is, a detection beam, and when the human body moves this detection beam, infrared rays incident on the infrared detection element suddenly change. Since it changes and a large output is obtained, a human body can be detected. In addition, in order to make the human body detection device capable of detecting a human body, that is, a wide detection area, a plurality of detection beams may be arranged in the detection area. For this reason, a multi-segment lens composed of a plurality of lenses or a multi-segment mirror composed of a plurality of mirrors is used for the light collecting unit.

FIG. 11 shows an example of a multi-segment lens used in a conventional human body detecting device. The multi-segment lens r0 is a simple multi-segment lens having a flat first surface, and can be used when the detection area is relatively small. The incident angle of the beam BM becomes large. Therefore, in the peripheral portion, there is a problem that the influence of aberration is increased and the detection sensitivity is reduced, that is, the influence of so-called “blur” cannot be ignored.

Next, another example of a multi-segment lens used in a conventional human body detecting device is shown in FIG. This multi-segment lens is a so-called dome-shaped multi-segment lens in which each lens is arranged so as to be substantially perpendicular to the optical axis of the detection beam BM, and is similar to the multi-segment lens shown in FIG. "Blur" is reduced and light collection efficiency is improved. However, when this multi-segment lens is used, the image magnification of the detection beam BM at the periphery of the detection area becomes larger than that at the center of the detection area, and the detection beam BM becomes larger on the object surface. The size of the detection beam BM in the inside cannot be made uniform. That is, in the peripheral portion, there is a problem that the detection sensitivity per unit area is reduced, and the detection sensitivity is not uniform depending on the location even in the same detection area.

FIG. 13 shows another example of the multi-segment lens used in the conventional human body detecting device. In this multi-segment lens, each lens is arranged such that each lens is substantially perpendicular to the optical axis of the detection beam BM and the height of the principal point of each lens from the infrared detecting element is substantially constant. It is. With this multi-segment lens,
Even in the peripheral area of the detection area, there is no “blur” as described above, and the detection beam BM does not increase. Therefore, the size of the detection beam BMM in the detection area can be made uniform.

However, since the multi-segment lens has a large number of lenses and a large number of irregularities and a complicated shape, there are technical difficulties in the steps of manufacturing and molding the mold of the multi-segment lens. Further, it is not practical because of the cost.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a detection beam having a uniform size over a wide detection area is provided by a multi-splitting lens having a relatively simple shape. An object of the present invention is to provide an infrared human body detector that can be arranged to detect the movement or slight movement of a human body, and to provide a human body detection lens for this purpose at low cost.

[0010]

According to the first aspect of the present invention, there is provided a human body detecting lens according to the present invention, which is used in a human body detecting device provided with an infrared detecting element, and receives infrared rays emitted from a human body on a light receiving surface of the infrared detecting element. A first multi-segment lens, and a second multi-segment lens disposed on the side surface thereof, the first multi-segment lens is a first surface on the light source side And a second surface on the infrared detection element side, comprising a plurality of lens surfaces, the second multi-segment lens, the first surface on the light source side, comprises a plurality of lens surfaces, the infrared detection element With the second side and the first
The position of the principal point of all the multiple lens surfaces that make up the split lens
The first multi-segment lens is arranged at substantially the same height from the infrared detection element, and the shape of the first surface on the light source side of the first multi-segment lens is flat, and the first multi-segment lens and the second multi-segment lens Are integrated by being connected by a surface that coincides with the side surface of the polygonal pyramid formed with the light receiving surface of the infrared detection element as the vertex, and each lens constituting the second multi-segment lens is Are arranged so as to be perpendicular to the optical axis of each detection beam, and constitute a second multi-segment lens.
Position of the principal point of the closed surface is almost the same height as the infrared detector.
That constitute the first multi-segment lens
At the same height as the principal points of all lens surfaces
It is characterized by having been done.

According to a second aspect of the present invention, there is provided a human body detecting lens according to the present invention, which is used in a human body detecting device having an infrared detecting element, and which collects infrared rays emitted from a human body on a light receiving surface of the infrared detecting element. A first multi-segment lens, and a second multi-segment lens disposed on a side surface of the first multi-segment lens. The first multi-segment lens has a first surface on a light source side and a plurality of lens surfaces. And a second surface on the infrared detection element side, the second multi-segment lens is composed of a first surface on the light source side and a plurality of lens surfaces, a second surface on the infrared detection element side Wherein the shape of the first surface on the light source side of the first multi-segment lens is flat, and the first multi-segment lens is
The positions of the principal points of all the lens surfaces constituting the lens are infrared
The second multi-segment lens is disposed at approximately the same height from the line detection element , and the second surface on the light source side of the second multi-segment lens has a curved lens surface shape. The contact surface with the split lens is integrated by being connected at a surface corresponding to the side surface of the cone formed with the light receiving surface of the infrared detection element as the vertex, thereby forming the second multi-split lens. The lenses are arranged so as to be perpendicular to the optical axis of each detection beam, and constitute a second multi-segment lens.
Position of the principal point of the lens surface
Constructs the first multi-segment lens located at the same height
The height is almost the same as the position of the principal point of all the lens surfaces
Characterized by being arranged in The human body detecting lens according to the present invention described in claim 3 is a human body detecting lens according to claim 1 or 2, in which the shape of the first surface on the light source side of the first multi-segment lens is a flat surface. Instead, it is characterized by a curved surface of the lens surface shape.

Here, the first surface means a surface on the light source side of the lens, and the contact surface of the polygonal pyramid surface or the conical surface means a surface in contact with these surfaces.

[0013]

FIG. 2 is a block diagram showing an example of an infrared type human body detecting apparatus using the human body detecting lens according to the present invention. The infrared type human body detection device 1 is for detecting a slight movement of a human body and automatically controlling a lighting apparatus, and includes a light collecting unit 10 having a multi-segment lens, an infrared detection element 11, Amplifier 1
2, a band-pass filter 13, a comparing means 14, a delay circuit 15, and an output circuit 16.

The infrared rays emitted from the human body are
Is focused on the infrared detecting element 11 by the multi-segment lens of
It is converted into an electric signal by the infrared detecting element 11. The detection signal detected by the infrared detecting element 11
2, the frequency components unnecessary for the detection of the human body are removed by the bandpass filter 13. Thereafter, the comparing means 14 makes a detection judgment by comparing the detection signal with a predetermined detection level. The delay circuit 15 holds the determination result for a short time, and the output circuit 16 outputs a signal for turning on and off the lighting and the like.

In general, when the discrimination signal is output from the comparison circuit 14, the illumination or the like is turned on. When the discrimination signal is no longer output from the comparison circuit 14, the delay circuit 15 causes the preset off-delay time to elapse. Measure, and then turn off the lighting. However, if a new determination signal is output from the comparison circuit 14 before the elapse of the off-delay time, the measurement of the off-delay time is updated. For this reason, while detecting the human body, the lighting and the like are not turned off.

Next, the principle of the infrared type human body detection device will be described. In the infrared type human body detection device, when the human body passes through the detection beam, the change in the amount of infrared light incident on the optical system changes based on the temperature difference between the background in the detection beam and the human body. This change is detected by the infrared detecting element to determine the presence or absence of a human body. FIG. 3 shows an example of the output signal of the infrared detection element when the human body passes through one detection beam.
FIG. 3A is a view of the relationship between the human body M and the detection beam BM viewed from above, and FIGS. 3B to 3D show cases where the human body M passes at a low speed, a medium speed, and a high speed, respectively. FIG. 3 is a diagram showing output signals of the first embodiment. FIG. 4 shows an example of an output signal of the infrared detecting element when the human body passes through two detection beams. Like FIG. 3, FIG. 4A shows the relationship between the human body M and the detection beam BM viewed from above, and FIGS. 4B to 4D show low speed, medium speed, and high speed, respectively. FIG. 6 is a diagram illustrating an output signal when the vehicle passes at a speed.

FIG. 5 shows a state in which such an infrared human body detecting device 1 is installed on the ceiling of an office. The mounting height of the infrared human body detection device 1 on the ceiling T is 2 to 2.
It is generally about 7 m, and the distance from the ceiling T to the desk D is about 1.3 to 2 m. Normally, as the distance from the infrared human body detection device 1 to the target to be detected increases, the size of the detection beam BM and the distance between the detection beams BM increase, and the detection performance deteriorates. The distance may be considered as a maximum of 2 m, which is the distance to the desk.

FIG. 6 shows an example of the infrared detecting element 11a. This infrared detecting element is a four-element type infrared detecting element arranged so that the electrical characteristics of adjacent light receiving surfaces are opposite to positive or negative, and the detection signal is one output obtained by combining the outputs from the respective elements. Has become. The shape of one light receiving surface is a 1.1 mm square, and the gap between the light receiving surfaces is 1.5 mm.

FIG. 7 shows an example of the arrangement of the detection beam BM on the object surface 2 m ahead of the infrared detecting element 11a. As described above, the desk surface D is 2 m in front of the infrared detecting element 11a.
FIG. 7 shows a detection area SA formed on the desk upper surface D. This detection area SA is
148 detection beams are arranged in a grid at a center interval of about 20 cm, and the size of one detection beam BM is:
It is about 16 cm. Further, using the infrared detecting element 11a shown in FIG. 6, the electrical characteristics of all the adjacent detection beams are opposite to the positive and negative characteristics.

FIG. 1 shows an example of the configuration of a human body detecting lens according to the present invention. This human body detection lens RZ1 is a condenser lens 10 used in the above-described human body detection device 1, and FIG. 1A is a front view thereof, and FIG. 1B is a cross-sectional view thereof. is there. This human body detection lens RZ1 is a 37-divided wide-angle lens having a focal length of 13.5 mm, and the detection beam BM formed by each lens is in a lattice shape as shown in FIG.
The principal points of each lens are arranged at 5.5 mm intervals so that the distance between the centers is about 20 cm.

This human body detecting lens RZ1 is composed of a first multi-segment lens R1 having a plurality of condensing lenses arranged in the same plane and a second multi-segment lens disposed outside thereof. And the multi-segment lens R2. The first multi-segment lens R1 is a 21-segment lens composed of five types of lenses A, B, C, E, and F arranged in parallel with the infrared light receiving element 11, and the second multi-segment lens R2 Is a 16-divided lens composed of three types of lenses D, G, and H arranged so as to surround the first multi-segment lens R1.

Each of these eight types of lenses A to H is a lens having a flat first surface, and the height from the light receiving surface of the infrared detecting element 11 to the principal point of the lens is almost the same. Has become. Also, the second multi-segment lens R2
, Each of which has a detection beam BM
Is almost perpendicular to the optical axis of For these lenses, a spherical lens or an aspherical lens is usually used, but when it is necessary to increase the incident amount of infrared rays,
Fresnel lenses can be used. For example, an aspheric lens may be used for each lens constituting the first multi-segment lens R1, and a Fresnel lens may be used for each lens constituting the second multi-segment lens R2.

In this human body detecting lens, the first multi-segment lens R1 and the second multi-segment lens R2 are connected at a contact surface of a polygonal pyramid whose apex is the light receiving surface of the infrared detecting element 11, and are integrally formed. Has been Here, the first multi-segment lens R1 has a detection beam BM at the center of the detection area SA.
Is formed, the incident angle of the detection beam BM is small, and “blur” is small. Further, the first multi-segment lens R
In each lens of No. 1, since the height of the principal point is substantially constant, the size of the detection beam BM on the object surface having a predetermined height can be made constant.

In the second multi-segment lens R2, the 16 lenses are arranged so as to be substantially perpendicular to the optical axis of the detection beam BM.
Has a small incident angle, and "blur" hardly occurs. Further, the second multi-segment lens R2 is arranged such that the height of the principal point of each lens is substantially the same as the height of the principal point of the first multi-segment lens R1, so that the predetermined height The size of the detection beam BM on the object surface is substantially the same as the size of the detection beam BM formed by the first multi-segment lens R1.

Accordingly, while the first multi-segment lens R1 covers the area from the center of the detection area SA to the intermediate portion between the center and the periphery, the second multi-segment lens R2
By covering the peripheral portion from the intermediate portion, a uniform detection beam BM can be formed over the entire detection area SA and "blur" can be prevented, so that detection of each portion of the detection area can be performed. Sensitivity can be made almost constant.

Further, since the second multi-segment lens R2 forms an angle with the first multi-segment lens R1, the first and second multi-segment lenses R1 and R2 are formed in the same plane. As compared with the case, a larger lens area of the second multi-segment lens R2 can be secured. For this reason, the light collection efficiency of infrared rays can be improved, and the detection sensitivity can be improved.

As shown in FIG. 8, for the lenses C and F at the peripheral portion of the first multi-segment lens R1, the incident angle of the detection beam BM is about 40 degrees, so that the detection beam Although it is considered that there is “blur”, the detection beam BM formed by the lenses C and F is located in the middle of the detection area SA, and the human body that is affected by this detection beam is the second multi-segment lens R2. Also affects the detection beam BM formed by the lenses D, G, H. If a large number of detection beams BM are on the human body in this way,
The detection sensitivity does not decrease even for a slight movement of the human body.

FIG. 9 shows an example of the configuration of a human body detecting lens according to the second aspect of the present invention. This human body detecting lens RZ2 is a condensing lens 10 used in the human body detecting device 1 as in the case of the human body detecting lens shown in FIG. 1, and FIG. 9A is a front view thereof. FIG. 9B is a cross-sectional view thereof. The human body detection lens RZ2 has a curved first lens surface shape of the second multi-segment lens R2 of the human body detection lens RZ1 shown in FIG. 1, and a first surface of the first multi-segment lens R1. Is a plane. Further, the outer shape of the first multi-segment lens R1 is circular, and the first and second multi-segment lenses R1 and R2 are connected at a contact surface of a conical surface whose vertex is the light receiving surface of the infrared detecting element 11, and are integrally formed. Has been

Here, the number of mold blocks for molding the human body detecting lens is required by the number of the planes. For this reason, by making the first surface of the second multi-segment lens RZ2 a curved surface, the number of mold parts of the lens can be reduced as compared with the case where the first surface of each lens is formed into a flat surface. In addition, the appearance can be improved. FIG. 10 shows a configuration example of the human body detecting lens according to the third aspect of the present invention. FIG. 10A shows a case where the present invention is applied to the human body detection lens RZ1 shown in FIG.
(B) is applied to the human body detection lens RZ2 shown in FIG.

That is, FIGS. 9A and 9B both show that the first surface of the first multi-segment lens R1 is formed into a curved surface, and in the case of FIG. In the case of (b), the first surface of the lens R2 is formed into a flat surface, and the first surface of the second multi-segment lens R2 is formed into a curved surface. In this manner, by forming the first surface of the first multi-segment lens R1 into a curved surface, a position of each lens of the first multi-segment lens R1 far from the center of the detection area SA, that is,
“Blur” of the lenses C and F, which are lenses that form the detection beam BM in the intermediate portion, can be reduced, and the detection sensitivity of each part of the detection area SA can be constant.

[0031]

According to the first aspect of the present invention, there is provided a human body detecting lens according to the present invention, comprising a first lens and a second lens, wherein the first multi-segment lens is located between the center and the middle of the detection area. , The incident angle does not become so large. On the other hand, since the second multi-segment lens covering the intermediate portion to the peripheral portion is arranged so as to be perpendicular to the detection beam, the incident angle does not increase.

Since the principal points of all the lenses are at the same height from the infrared detecting element, the size of the detection beam can be made the same. In other words, a uniform detection beam can be formed over the entire detection area and "blur" can be prevented from occurring, so that the detection sensitivity of each part of the detection area can be made substantially constant.

Further, since the second multi-segment lens forms a fixed angle with the first multi-segment lens, a larger lens area of the second multi-segment lens is ensured, and the infrared light focusing efficiency is improved. Can be improved, and the detection sensitivity can be improved. The human body detection lens according to the present invention described in claim 2 has a first surface of the second multi-segment lens having a curved surface, so that the first surface of each lens is formed as a flat surface. The number of mold parts can be reduced. In addition, the appearance can be improved.

A third aspect of the present invention is a lens for forming a detection beam at a position far from the center of a detection area by forming a first surface of a first multi-segment lens as a curved surface. Can be reduced, and the detection sensitivity of each part of the detection area can be kept constant.

[Brief description of the drawings]

FIG. 1 is a diagram showing one configuration example of a human body detecting lens according to the present invention described in claim 1;

FIG. 2 is a block diagram illustrating a configuration example of an infrared human body detection device.

FIG. 3 is a diagram illustrating an example of an output signal of an infrared detection element.

FIG. 4 is a diagram illustrating an example of an output signal of an infrared detection element.

FIG. 5 is a diagram showing an example of installation of an infrared human body detection device.

FIG. 6 is a diagram illustrating an example of an infrared detection element.

FIG. 7 is a diagram illustrating an example of a detection area.

FIG. 8 is a diagram illustrating an example of an incident angle of a detection beam.

FIG. 9 is a view showing a configuration example of a human body detecting lens according to the present invention described in claim 2;

FIG. 10 is a view showing a configuration example of a human body detecting lens according to the present invention described in claim 3;

FIG. 11 is a view showing a configuration of a conventional human body detection lens.

FIG. 12 is a diagram showing a configuration of a conventional human body detection lens.

FIG. 13 is a diagram showing a configuration of a conventional human body detection lens.

[Explanation of symbols]

RZ1, RZ2, RZ1 ', RZ2': human body detecting lens R1: first multi-segment lens R2: second multi-segment lens 10: condensing lens 11: infrared detecting element 11a: infrared detector BM: detection beam

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Yamaguchi 1048 Oaza Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Works, Ltd. (56) References JP-A-3-46590 (JP, A) JP-A-5-256695 (JP, A) JP-A-6-300620 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01J 1/02-1/04 G01J 5/02-5/08 G01V 9 / 04 G02B 3/08

Claims (3)

(57) [Claims] 1. A condensing lens for use in a human body detecting device having an infrared detecting element and condensing infrared light emitted from a human body on a light receiving surface of the infrared detecting element, comprising: a first multi-segment lens; The first multi-segment lens is constituted by a first surface on the light source side and a plurality of lens surfaces, and the second multi-segment lens on the infrared detection element side. and a surface, the second multi-segment lens, a first side of the light source side is composed of a plurality of lens surfaces, and a second surface of said infrared detecting element side, the first multi All multiple lenses that make up a split lens
The position of the principal point on the surface is almost at the same height from the infrared detector.
Is location, the first shape of the first surface of the light source side of the multi-segment lens are planar, and the first multi-segment lens contacting surface of said second multi-segment lens, infrared detection Each lens constituting the second multi-segment lens is integrated by being connected by a surface corresponding to the side surface of the polygonal pyramid formed with the light receiving surface of the element as a vertex, and the light of each detection beam is The lens is disposed so as to be perpendicular to the axis, and the position of the principal point of the lens surface constituting the second multi-segment lens
Are arranged at substantially the same height from the infrared detecting element.
The plurality of lenses constituting the first multi-segment lens
Are located at almost the same height as the principal point of the lens surface.
Characterized in that that the human body detection lens. 2. A condensing lens for use in a human body detecting device having an infrared detecting element and condensing infrared light emitted from a human body on a light receiving surface of the infrared detecting element, comprising: a first multi-segment lens; The first multi-segment lens is constituted by a first surface on the light source side and a plurality of lens surfaces, and the second multi-segment lens on the infrared detection element side. The second multi-segment lens comprises: a first surface on the light source side; and a second surface on the infrared detection element side, comprising a plurality of lens surfaces; The shape of the first surface on the light source side of the split lens is a flat surface, and all the plurality of lenses constituting the first multi-split lens
The position of the principal point on the surface is almost at the same height from the infrared detector.
A second surface on the light source side of the second multi-segment lens is a curved surface of a lens surface shape, and a contact surface between the first multi-segment lens and the second multi-segment lens. Are integrated by being connected at a surface corresponding to the side surface of the cone formed with the light receiving surface of the infrared detecting element as the apex, and each of the lenses constituting the second multi-segment lens is connected to each of the detection surfaces. The second multi-split lens is disposed so as to be perpendicular to the optical axis of the beam, and the position of the principal point of the lens surface constituting the second multi-segment lens
Are arranged at substantially the same height from the infrared detecting element.
The plurality of lenses constituting the first multi-segment lens
Are located at almost the same height as the principal point of the lens surface.
Characterized in that that the human body detection lens. 3. The first multi-segment lens according to claim 1, wherein the first surface on the light source side of the first multi-segment lens is a curved surface of a lens surface instead of a flat surface. For human body detection.