JPH07324979A - Narrow area infrared detector - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an infrared detection device that can obtain a narrow detection area without using a Fresnel lens, and that can easily perform fine adjustment of the detection area and is inexpensive and easy to manufacture. . [Structure] The infrared detector is a pyroelectric infrared detector S.
And a necessary circuit component 43 for processing the detection signal output from the pyroelectric infrared detector, and a storage case 41 for storing these components. A predetermined distance d is provided between the pyroelectric infrared detector S and the infrared incident hole 41a of the storage case according to a desired detection area. The detection area can be changed by providing a moving mechanism for moving the pyroelectric infrared detector close to or away from the infrared entrance hole or by adjusting the size of the infrared entrance hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared detecting device used in a human body detecting system for detecting infrared rays emitted from a human body, and more particularly to an infrared detecting device having a simple structure and high practicality.

[0002]

2. Description of the Related Art A human body detection system using a pyroelectric infrared detector or the like detects infrared rays emitted from a human body or the like that has entered a detection area of the detection system. This detection area was determined by the design of the infrared detector or the design of the Fresnel lens provided in front of the infrared detector. An example of the infrared detector is a pyroelectric infrared detector as shown in FIG. In FIG. 12, the infrared detector has two infrared absorption films (blackening films) 11 and 11 electrically connected to each other on the front surface, and an electrode 12 for taking out generated charges on the back surface. An electric circuit board 1, a printed circuit board 2 on which the pyroelectric circuit board 1 is mounted via conductive supports 21 and 21, and a printed circuit board 2
Necessary circuit parts 22 and 23 attached to the back of the
Lead terminals 31a, 31a for supporting the printed circuit board 2,
It includes a base 31 in which 31a are planted so as to be insulated from each other, a cap 32 that is hermetically joined to the base 31 and has a window portion 32a on the upper surface, and an optical filter 33 attached to the window portion 32a. The pyroelectric infrared detector of the type in which two or more infrared absorbing films are provided in this way is known as a structure that prevents malfunction due to changes in the ambient temperature and changes in the ambient environment such as ambient light.
The detection area can be adjusted by the size, spacing, window size, etc. of the infrared absorption films 11, 11 of the infrared detector. However, conventionally, from the viewpoint of design and manufacturing, it has been a general design method that the detection area of the infrared detector is fixed and the desired detection area is determined by the Fresnel lens. That is, a Fresnel lens designed for a wide area is used to obtain a wide detection area, and a Fresnel lens designed for a narrow area is used to obtain a very narrow detection area.

[0003]

However, the structure of the Fresnel lens is complicated, and it is necessary to design for each detection area. Especially, when a plurality of narrow detection areas are to be obtained, the number of the detection areas is reduced. A Fresnel lens was required, and it was difficult to finely adjust the detection area.

The present invention has been made in order to solve the above problems, and it is possible to obtain a narrow detection area without using a Fresnel lens, and the fine adjustment of the detection area is easy and inexpensive. An object of the present invention is to provide an infrared detection device that is easy to manufacture.

[0005]

In order to solve the above problems, an infrared detecting device according to the present invention is an infrared detecting device in which an infrared detector for detecting movement of an infrared source is housed in a housing case. The storage case has an elongated infrared incident hole extending substantially at right angles to the detection direction, and the infrared detector is installed within the storage case at a predetermined distance from the infrared incident hole, thereby setting a narrow detection area. It is characterized by doing.

Further, in the narrow-range infrared detecting device according to claim 1, the infrared detector is provided with a moving mechanism for approaching and separating from the infrared incident hole in the housing case, and detection is performed by this movement. You may adjust the area.

Further, in the narrow-range infrared detecting device according to claim 1 or 2, wherein a transparent plate is provided in front of the infrared entrance hole, an elongated transparent portion is formed in a central portion of the transparent plate. As described above, the non-light-transmitting portion may be provided in the periphery, and the detection area may be adjusted by changing the size of the light-transmitting portion.

[0008]

Since the infrared detector is installed inside the housing case by a predetermined size from the elongated infrared entrance hole, the infrared entrance range is limited and the detection area can be set to a narrow area. The detection area can be adjusted by the shape and size of the infrared incident hole and the distance between the infrared detector and the infrared incident hole.

FIG. 10 is a diagram showing the relationship between the distance between the infrared detector and the infrared incident hole and the detection area, and FIG. 11 is a diagram showing the relationship between the size of the infrared incident hole and the detection area. As is apparent from FIG. 10, the infrared detector S1 arranged far from the infrared incident hole obtains a narrower detection area (shown by a solid line) than the infrared detector S2 arranged closer to the infrared incident hole. Further, as is apparent from FIG. 11, the infrared detection hole W1 having a wide opening size has a wider detection area than the infrared detection hole W2 having a narrow opening size. The detection area may be adjusted by each of these elements.

According to the second aspect, since the infrared detector in the storage case can be moved toward and away from the infrared incident hole, the detection area can be easily changed and finely adjusted. it can.

According to a third aspect of the present invention, in a narrow area type infrared detecting device having a transparent plate on the front surface of the infrared entrance hole, an elongated transparent portion is formed in the central portion of the front and back plate surfaces of the transparent plate. Since a non-translucent portion is provided in the periphery and the detection area is adjusted according to the size of the transparent portion, the detection area can be easily changed and finely adjusted.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings by taking an infrared detecting device using a pyroelectric infrared detector as an example. FIG. 1 is a partially cutaway perspective view showing a first embodiment,
2 is an internal plan view of FIG. 1, FIG. 3 is an internal side view of FIG. 1, and FIG. 4 is a front view seen from the infrared ray incident surface.
FIG. 5 is a plan view of the infrared detector, and FIG. 6 is a diagram showing a detection area.

The infrared detector is a pyroelectric infrared detector S.
And a necessary circuit component 43 for processing the detection signal output from the pyroelectric infrared detector, and a storage case 41 for storing these components.

The pyroelectric infrared detector S has the same construction as that described with reference to FIG. 12 in the conventional example. As shown in FIG. Infrared absorption films 11 and 11 are arranged in parallel and are electrically connected to each other. Such a pyroelectric infrared detector S is mounted on the printed wiring board 42 together with necessary circuit components 43 for processing the detection signal. Since the detection circuit is already known, the description thereof will be omitted.
The printed wiring board 42 is stored in the storage case 41. The storage case 41 has a long and narrow infrared ray incident hole 41a on its infrared ray incident surface, and the infrared ray incident surface of the pyroelectric infrared detector is arranged so as to be located at a substantially central portion of the infrared ray incident hole 41a. At this time, the infrared absorption film 11,
11 are arranged so that the direction in which they are lined up is orthogonal to the longitudinal direction of the infrared ray incident hole 41a. That is, the longitudinal direction of the infrared incident hole 41a is arranged in the direction orthogonal to the detection direction K. A transparent plate 44 made of a glass plate is attached to the infrared ray incident hole portion to prevent malfunction due to wind or the like. Further, the pyroelectric infrared detector S and the infrared incident hole 41a are provided with a predetermined distance d depending on a desired detection area. In addition to these, as a factor that determines the detection area, the longitudinal dimension w of the infrared entrance hole,
Similarly, there is a lateral dimension l, and the detection area is determined by adjusting each of these three dimensions.

In such an infrared detecting device, the shape of the infrared incident hole, the pyroelectric infrared detector S, and the infrared incident hole 41a are used.
By setting and adjusting the distance d between them to a predetermined value, an elongated strip-shaped detection area can be obtained in a direction orthogonal to the detection direction K as shown in FIG.

Next, a specific example of the detection area will be described. A pyroelectric infrared detector having a sensitivity of 1200 V / W is used, and the dimension d = 15 mm, dimension w = 3 mm, dimension l = 30.
If mm, height P = 2m, length Q = 3m, width R = 5
An elongated strip-shaped detection area of 0 cm could be obtained. A pyroelectric infrared detector having a sensitivity of 1200 V / W is used. When the dimension d = 15 mm, the dimension w = 2 mm, and the dimension l = 30 mm, the height P = 2 m and the length Q = 3. .7
It was possible to obtain an elongated strip-shaped detection area of m and width R = 37 cm. Furthermore, the pyroelectric infrared detector has a sensitivity of 12
00V / W, the dimension d = 20mm, dimension w
= 3 mm, and dimension l = 30 mm, it was possible to obtain an elongated strip-shaped detection area having a height P = 2 m, a length Q = 2.8 m, and a width R = 38 cm.

A second embodiment will be described with reference to the drawings. FIG. 7 is an internal plan view showing the second embodiment, and FIG.
FIG. The pyroelectric infrared detector S having the same configuration as that of the first embodiment is mounted on the printed wiring board 52 together with other necessary circuit components 53 for processing other detection signals. The printed wiring board 52 and the battery B are stored in the storage case 5.
1 and make the necessary electrical connections. In this embodiment, the pyroelectric infrared detector S is arranged such that its infrared ray incident surface is substantially orthogonal to the plate surface of the printed wiring board, and this printed wiring board is in a direction orthogonal to the infrared ray incident hole (that is, the printed surface). The wiring board is placed flat in the storage case). In addition, the entire printed wiring board is configured to be movable up and down inside the storage case. More specifically, a slide type lever L is provided outside the storage case, and the inside of the storage case of the lever is connected to a part of the printed wiring board.
By sliding this lever, the printed wiring board can be moved so as to be close to and away from the infrared ray incident hole. Further, as in the first embodiment, the bottom surface (infrared ray detection surface) of the storage case 51 has an elongated infrared ray incident hole 51a, and the infrared ray incident surface of the pyroelectric infrared detector is almost the same as the infrared ray incident hole 51a. It is arranged to be located in the central portion. At this time, the infrared absorbing films 11 and 11 are arranged so that the direction in which the infrared absorbing films 11 are aligned are orthogonal to the longitudinal direction of the infrared incident hole 51a. That is, the infrared entrance hole 5
The longitudinal direction of 1a is arranged in a direction orthogonal to the detection direction K. A transparent plate 5 made of a glass plate is provided in the infrared entrance hole portion.
4 is attached to prevent malfunction due to wind or the like.

According to this embodiment, since the printed wiring board is installed flat, the storage case can be made thin, which contributes to the thinning of the infrared detection device as a whole. Further, since a mechanism for moving the printed wiring board up and down is provided, the movement can freely change the detection area within a predetermined range, and to obtain an infrared detection device in which fine adjustment of the detection area is easy. You can

This moving mechanism can also be adopted in the configuration of the first embodiment, and similarly, the detection area can be freely changed within a predetermined range, and an infrared detection device with easy fine adjustment can be obtained. be able to. Further, this moving mechanism is not limited to the above-mentioned embodiment, and a plurality of convex portions on the storage case side of the slide lever and concave portions on the storage case side are provided in a row in the sliding direction at predetermined intervals.
It is possible to use a known technique such as operating the slide lever to fit the convex portion and the concave portion at a predetermined position to hold the position.

A third embodiment will be described with reference to FIG. FIG. 9 is a plan view seen from the infrared incident surface of the infrared detection device. Infrared incident hole 6 is formed on the infrared incident surface of storage case 61.
1a is provided, the outer dimensions of the infrared entrance hole have an opening area slightly larger than that of the above-described embodiment. The translucent plate 62 attached to this infrared incident surface is
A non-light-transmitting portion 62b, which has been subjected to a black color treatment or the like, is provided on the periphery so as to form an elongated light-transmitting portion 62a at the center of the plate surface. The detection area can be changed and adjusted by appropriately changing the size of the transparent portion 62a.

The adjustment of the infrared ray entrance hole by the transparent plate can also be adopted in the first and second embodiments.
It is also possible to prepare a plurality of types of light-transmitting plates with different settings of the light-transmitting part and the non-light-transmitting part, and attach the necessary light-transmitting plates according to the desired detection area.

[0022]

According to the present invention, the infrared detector can be installed in the storage case without using the Fresnel lens which is conventionally required to set the detection area of the infrared source.
Since it is installed inside the elongated infrared entrance hole by a predetermined size, the infrared entrance range is limited, and the detection area can be set to a narrow area. Therefore, it is possible to obtain an inexpensive infrared detection device that is easy to design and manufacture. As described above, the detection area can be easily adjusted by the shape of the infrared incident hole and the distance between the infrared detector and the infrared incident hole.

According to the second aspect of the present invention, the infrared detector in the storage case can be moved closer to and farther from the infrared entrance hole, so that the detection area can be changed and finely adjusted, which has been troublesome in the past. It can be done easily.

According to the third aspect of the invention, in the narrow-range infrared detecting device in which a transparent plate is provided in front of the infrared entrance hole,
Since a non-light-transmitting part is provided around the center of the front and back plate surfaces of this light-transmitting plate to form a thin light-transmitting part, and the detection area is adjusted according to the size of this light-transmitting part, it is difficult to detect conventionally. The area can be easily changed and finely adjusted.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing a first embodiment according to the present invention.

FIG. 2 is an internal plan view of FIG.

FIG. 3 is an internal side view of FIG.

FIG. 4 is a front view of an infrared detection device.

FIG. 5 is a plan view of an infrared detector.

FIG. 6 is a diagram showing a detection area of an infrared source.

FIG. 7 is an internal plan view showing a second embodiment according to the present invention.

FIG. 8 is a front view of FIG.

FIG. 9 is a front view showing a third embodiment.

FIG. 10 is a diagram showing changes in a detection area.

FIG. 11 is a diagram showing a change in a detection area.

FIG. 12 is an internal cross-sectional view of a general pyroelectric infrared detector.

[Explanation of symbols]

 1 Pyroelectric Substrate 2 Printed Circuit Board 31 Base 32 Cap 33 Optical Filter 41, 51 Storage Case 42, 52 Printed Wiring Board 44, 54 Translucent Body S Pyroelectric Infrared Detector

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G01V 8/12

Claims (3)

[Claims] 1. An infrared detection device in which an infrared detector for detecting movement of an infrared source is housed in a housing case, the housing case having an elongated infrared entrance hole extending substantially at right angles to the detection direction. The narrow-range infrared detecting device, wherein the container is installed inside the housing case by a predetermined distance from the infrared entrance hole. 2. The infrared detector is provided with a moving mechanism in the housing case that moves closer to or away from the infrared entrance hole, and the detection area is adjusted by this movement. Narrow-range infrared detector. 3. A narrow-range infrared detecting device having a light-transmitting plate provided in front of an infrared-ray entrance hole, wherein a non-light-transmitting part is provided around the light-transmitting plate so that an elongated light-transmitting part is formed in the central part of the light-transmitting plate. ,
The narrow area type infrared detecting device according to claim 1 or 2, wherein the detection area is adjusted by changing the size of the light transmitting portion.