JP2013044586A - Pyroelectric infrared detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pyroelectric infrared detection device that can perform fine adjustment of the light reception quantity of incident energy of infrared radiation from human bodies or the like.SOLUTION: A pyroelectric infrared detection device uses a plate 4 having at least one open hole. Arrangement of a plate having at least one open hole between a detection area and a pyroelectric infrared detector 2 allows adjustment of the light reception quantity of infrared radiation energy from human bodies or the like.

Description

  The present invention is a pyroelectric infrared detector using a plate having at least one through hole, and at least one through hole is provided between the infrared detection region and the pyroelectric infrared detector as shown in FIG. The present invention relates to a pyroelectric infrared detector capable of adjusting the amount of received infrared energy emitted from a human body or the like by arranging a plate having a hole.

  The conventional pyroelectric infrared detector is a resin molding that collects the infrared radiation from the infrared detection area so that it can be used in a wide range of locations without limiting the installation location and installation environment of the pyroelectric infrared detector. The optical lens is constructed so as to have an infrared detection region that is divided into designs by installing the optical lens so that the focal point is aligned with the pyroelectric infrared detector.

  The resin-molded optical lens generally uses a resin material made of an infrared transmitting material. For example, when dividing a detection target surface in a certain range into a plurality of infrared detection regions, a small lens having a convex shape or a Fresnel shape is used. It is configured as a multi-aggregate lens in which segments are densely arranged, and the outer shape of the resin-molded optical lens portion is often a thin spherical shape or an aspherical shape.

  The resin-molded optical lens 4 provided in the pyroelectric infrared detector is optically designed in consideration of the focal length relationship with the infrared light receiving element 1 as a condensing lens, and the infrared detection region is determined by the arrangement of the segments. Is done. An infrared light receiving element disposed inside the pyroelectric infrared detector senses infrared light that has entered the infrared detection area and is emitted from a human body or the like.

  When constructing an infrared detection area, it is configured as a multi-aggregate lens that is a collection of convex or Fresnel-shaped small lens segments. When finely adjusting the amount of incident infrared radiation emitted from the human body, etc. Had fine-tuned the amount of received infrared energy emitted from each infrared detection area by adjusting the segment area.

  The infrared detection area extends geometrically at infinity. Therefore, when performing distance detection, it is the mainstream to perform distance detection by providing a depression angle in the pyroelectric infrared detection device itself.

Japanese Patent Application No. 6-143875

  As described above, when finely adjusting the amount of infrared incident energy emitted from the human body, etc., the amount of received infrared energy emitted from each infrared detection area was finely adjusted by adjusting the segment area. Changing the area alone is difficult because there is a limit to the adjustment of the amount of light received.

  When adjusting the amount of received infrared energy emitted from each infrared detection area, in addition to adjusting each segment area, the shape of the infrared light receiving element arranged inside the pyroelectric infrared detector or the area of the infrared light receiving element is changed. By doing so, the infrared detection area shape or the infrared detection area size can be adjusted. However, when changing the shape of the infrared light receiving element arranged inside the pyroelectric infrared detector, the shape of the infrared detection area or the size of the infrared detection area is changed in all infrared detection areas. It was difficult to arbitrarily change the infrared detection area shape or the infrared detection area size.

  For reference, FIG. 9 shows the relationship between the signal output (magnification) and the noise output obtained from the pyroelectric infrared detector with one segment area ratio. In this case, the signal output (magnification) with respect to the noise output obtained from the pyroelectric infrared detector by reducing the segment area and reducing the amount of received infrared energy emitted from the infrared detection region is when the segment area is 100%. It can be seen that there is no difference in the signal output after the pyroelectric infrared detector when the segment area is 4.0 times and the segment area is 30%, and it is difficult to make fine adjustments by reducing the segment area. .

  In addition, when adjusting the signal output obtained from the pyroelectric infrared detector, it is also possible to adjust the amplifier gain constituted by the amplifier circuit section after the pyroelectric infrared detector. However, since the amount of received infrared energy emitted from all infrared detection areas is adjusted by the amplifier gain configured by the amplifier circuit section after the pyroelectric infrared detector, the signal output for each segment is adjusted. Things were difficult.

  Also, in conventional distance identification, a pyroelectric infrared detector is provided with a depression angle, an infrared detection area that extends to infinity is projected onto the floor, and the necessary infrared detection area is determined by the depression angle of the pyroelectric infrared detection apparatus. It is mainstream to do. However, when it is difficult to provide a depression angle in the pyroelectric infrared detection device due to restrictions on the housing or the like, distance detection is difficult because the infrared detection region can be detected geometrically at infinity.

  Further, the resin-molded optical lens is optically designed in consideration of the focal length relationship with the infrared light receiving element disposed inside the pyroelectric infrared detector 2 as a condensing lens, and formed on the infrared light receiving element. The positive polarity side area and the negative polarity side area are projected as an infrared detection region through the resin-molded optical lens. When there is no optical lens function, the plus (minus) polarity side area 6-a and the minus (plus) polarity side area 6-b formed in the infrared light receiving element are not condensed by the optical lens, but the infrared detection area. Therefore, there is also a problem that the signal output after the pyroelectric infrared detector is canceled because the plus (minus) polarity side area 6-a and the minus (plus) polarity side area 6-b overlap.

  As a countermeasure method, as shown in FIG. 11, a shielding plate 7 is used between the pyroelectric infrared detector and the resin-molded optical lens, and the plus (minus) polarity side area 6-a and the minus (plus) polarity side area 6- Although there is a method for preventing the overlap of b, it is not suitable for a mass production process and an increase in the number of parts and man-hours by inserting a shielding plate.

  In order to solve the above problems, the present invention is a pyroelectric infrared detection device using a plate having at least one or more through holes, and a through hole is provided between the infrared detection region and the pyroelectric infrared detector. By disposing the plate, it is possible to adjust the amount of received infrared energy emitted from a human body or the like by limiting the infrared detection region projected through the through hole.

  The pyroelectric infrared detection device according to the present invention can adjust the amount of received infrared energy emitted from a human body or the like by limiting the infrared detection area projected through the through-hole, It is possible to arbitrarily change the infrared detection region shape or the infrared detection region size for each infrared detection region depending on the number of through holes, the size of the through hole, and the shape of the through hole.

  In addition, the infrared detection area projected through the through hole can be arbitrarily changed by the arrangement of the through hole, and the installation location and installation environment of the pyroelectric infrared detection device are not limited, It can be used in a wide range of situations.

  Furthermore, when a resin-molded optical lens is not used, pyroelectric infrared detection is achieved by not providing a through hole near the line connecting the center of the pyroelectric infrared detector and the center of the plate having at least one through hole. The plus (minus) polarity side area 6-a and the minus (plus) polarity side area 6-b formed in the infrared light receiving element arranged inside the detector do not overlap, and the signal output after the pyroelectric infrared detector Can be detected without cancellation.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective structure figure which shows the pyroelectric infrared detection apparatus concerning Example 1 of this invention. It is a figure which shows the infrared detection area | region of the pyroelectric infrared detection apparatus concerning Example 1 of this invention. It is a figure which shows the infrared detection area | region at the time of using only the resin molding optical lens concerning Example 1 of this invention. It is a perspective structure figure which shows the pyroelectric infrared detection apparatus concerning Example 2 of this invention. It is a figure which shows the infrared detection area | region of the pyroelectric infrared detection apparatus concerning Example 2 of this invention. It is a figure which shows the infrared detection area | region of the pyroelectric infrared detection apparatus of another form concerning Example 2 of this invention. 1 is a structural diagram of a plate having at least one through hole according to the present invention. It is a structural diagram of the board which has at least 1 or more through-hole of another form concerning this invention. It is the graph which showed the relationship of the signal output (magnification) with respect to the noise output obtained from one segment area ratio and a pyroelectric infrared detector at the time of mounting the conventional resin molding optical lens. It is the graph which showed the relationship of the signal output (magnification) with respect to the noise output obtained when a through-hole size is changed. It is the figure which mounts the shielding board which prevents the overlap of the positive polarity side area and negative polarity side area which were formed in the infrared receiving element arrange | positioned inside the conventional pyroelectric infrared detector.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective structural view showing a pyroelectric infrared detector according to Embodiment 1 of the present invention. It is composed of a pyroelectric infrared detector 2 having an infrared light receiving element 1, a high-density polyethylene sheet 3-b capable of transmitting infrared light without an optical lens function, and a plate 4 having at least one through hole. Yes.

   FIG. 2 shows an infrared detection region 5-a through a through hole that is designed and divided according to the focal length relationship between the resin-molded optical lens 3-a and the infrared light receiving element disposed inside the pyroelectric infrared detector 2. An infrared detection region 5-b is formed through a resin-molded optical lens.

   Note that the infrared detection region 5-a through the through hole shown in FIG. 2 has at least one through hole, and can adjust the amount of received infrared energy emitted from the human body or the like. Infrared detection area 5-b through a resin-molded optical lens represents an infrared detection area created by the pyroelectric infrared detector 2 and the resin-molded optical lens 3-a. Represents. It is effective when forming a minimal infrared detection region. When the infrared detection region formed via the resin-molded optical lens 3-a is a, the infrared detection region size formed by using the plate 4 is 1 /2.5a and a minimum infrared detection region can be easily formed.

Further, as shown in FIG. 3, when an infrared detection area formed through the resin-molded optical lens 3-a is a, and a similar infrared detection area is formed by using the plate 4, a pyroelectric infrared is used. When the distance from the detector 2 to the resin-molded optical lens 3-a is a, by using the plate 4, the distance from the pyroelectric infrared detector 2 to the plate 4 is 1 / 1.15a. The infrared detector can be downsized.
FIG. 4 is a perspective structural view showing a pyroelectric infrared detector according to Embodiment 2 of the present invention. The plate 4 is provided with multiple through-holes, and further, through-holes of various sizes are provided. The through-hole size is preferably φ0.5 to φ3.0.

   As shown in FIG. 4, it is possible to easily adjust the amount of received infrared energy emitted from each infrared detection region by increasing the number of through holes and changing the size of the through holes. Therefore, the installation location and installation environment of the pyroelectric infrared detection device are not limited and can be used in a wide range of locations.

   Furthermore, as shown in FIG. 5, by arbitrarily setting the through-hole size as described above, it is possible to easily adjust the amount of received infrared energy radiated from each infrared detection region, for distance detection. The effect can be demonstrated against. The infrared detection area formed through the plate 4 can also be detected geometrically at infinity, but distance detection is possible by adjusting the amount of received infrared energy emitted from each infrared detection area by the through-hole size. Is possible.

   As a reference, a graph showing the relationship between the signal output (magnification) and the noise output obtained when the through-hole size is changed in FIG. It was confirmed that distance detection was possible because there was a difference in signal output from pyroelectric infrared detectors for each through-hole size.

   FIG. 6 is a diagram showing an infrared detection region of another form of pyroelectric infrared detection apparatus according to the second embodiment of the present invention. As shown in FIG. 5, the same effect can be obtained even by a method that does not use the resin-molded optical lens 3-a. Even when a high-density polyethylene sheet having no optical lens function and capable of transmitting infrared rays is used, a dead zone is formed by not providing a through hole on a line connecting the center of the pyroelectric infrared detector 2 and the center of the plate 4. I can do it. Due to this dead zone, the positive polarity area 6-a and the negative polarity area 6-b formed in the infrared light receiving element 1 disposed inside the pyroelectric infrared detector 2 do not overlap. Detection can be used without canceling the signal output after the pyroelectric infrared detector.

   FIG. 7 is a structural diagram of a plate having a through hole. Arbitrary infrared detection areas can be formed by having a large number of through-holes, and infrared rays radiated from each infrared detection area by arranging multi-size through-holes of φ0.5 to φ3.0 The distance can be detected by adjusting the amount of energy received. 7 is used when the resin-molded optical lens 3-a is not used, and the central portion has a gap between the through hole, which is equivalent to the shielding plate 7 shown in FIG. In order to obtain the effect, the infrared detection region shown in FIG. 6 can be created.

   FIG. 8 is a structural diagram of a plate having a through hole as in FIG. FIG. 8 is used when the resin-molded optical lens 3-a is used. Since it has an optical lens function, the plus (minus) polarity side area 6-a and the minus (plus) polarity side area 6-b do not overlap each other as in FIG. 6, and the central portion is provided with a through hole. .

   In addition, the use of the aforementioned plate 4 can prevent breakage due to external damage. For example, by using a metal material as the material of the plate 4, a metal material is used even when damage is caused by a sharp object from the outer surface, or even when thermal damage is applied, or through-holes are used. The size is φ3max. Therefore, the resin-molded optical lens 3-a or the pyroelectric infrared detector 2 can be prevented from external damage.

DESCRIPTION OF SYMBOLS 1 Infrared light receiving element 2 Pyroelectric infrared detector 3-a Resin molding optical lens 3-b High-density polyethylene sheet 4 Plate which has a through hole 5-a Infrared detection area | region through a through hole 5-b Resin molding optical lens 6-a Positive (minus) polarity side area 6-b Minus (plus) polarity side area 7 Shield plate

Claims (2)

  An infrared ray emitted from a human body or the like by arranging a plate having at least one through hole between the detection region and the pyroelectric infrared detector and limiting the detection region projected through the through hole Pyroelectric infrared detector that adjusts the amount of energy received.   The pyroelectric infrared detection device according to claim 1, wherein the amount of infrared energy radiated from a human body or the like is adjusted according to the number of the through holes and the size of the through holes in the through holes provided in the plate.

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