JP3129052U - Infrared detector - Google Patents

Abstract

In an infrared detector that combines a plurality of pyroelectric infrared detection elements and an optical system having a plurality of optical elements, each pyroelectric infrared detection element can have an independent detection region.
A plurality of pyroelectric infrared detection elements are used together with a pyroelectric infrared detection element stored in the same package, an optical system having a plurality of optical elements is combined, and the pyroelectric infrared detection element and the optical system are combined. By installing an infrared shielding plate in between, a plurality of pyroelectric infrared detection elements are combined with different optical elements to realize independent detection regions.
[Selection] Figure 1

Description

  The present invention relates to an infrared detector capable of identifying an area where a human body emitting infrared rays exists.

  Conventionally, as a means for detecting a human body, a pyroelectric infrared detection element that detects infrared radiation emitted from an object and outputs a change in the infrared energy as a change in an electrical signal is used. As shown in FIG. 6, the infrared detector for detecting the human body includes a pyroelectric infrared detector having a dual or quad infrared receiver and an optical system 1 such as a Fresnel lens having a plurality of optical elements. A method of combining the two is used. The detection area in the infrared detector having this configuration is determined by the size and shape of the light receiving electrode of the pyroelectric infrared detection element and the focal length with the optical system.

  Infrared rays radiated from the human body existing in the infrared detection region are condensed on a light receiving electrode inside the pyroelectric infrared detection element through the optical system, and the infrared detection element outputs an electrical signal in accordance with a change in infrared energy. As is well known, the pyroelectric infrared detecting element detects a temperature change. For this reason, when there is no movement of the human body in the detection region, or when the operation is very small or slow, no signal output can be obtained. Therefore, in order to subdivide the detection region and detect a minute operation, a method of combining optical systems having a plurality of optical elements is used. By this method, the change of the infrared energy emitted from the human body is output as an electric signal, and the change of the electric signal is caused by the human body using the electric signal amplifying means such as an operational amplifier and the electric signal comparing means such as a comparator. Whether or not the human body exists is output as a detection signal.

  As shown in FIG. 7, if a detection area as shown in FIG. 8 is realized by combining an optical system having one pyroelectric infrared detection element and a plurality of optical elements, the presence of a human body in the detection area can be detected. is there.

  However, in the detection area where it is impossible to identify the existence area of the human body, when identifying the area where the human body exists, pyroelectric infrared detection using a plurality of pyroelectric infrared detection elements and outputting detection signals It is necessary to identify the element and the detection area in the pyroelectric infrared detection element.

  On the other hand, it is possible to identify the region where the human body exists by combining a plurality of pyroelectric infrared detection elements and combining independent optical systems with each other. However, an independent optical system is provided for each pyroelectric infrared detection element. When the systems are combined, the mounting area increases depending on the focal length and size of each optical system, and it becomes an uneconomic solution means such as an increase in the number of components.

Therefore, due to the entanglement with cost, mounting area, and focal length of the optical system, a plurality of pyroelectric infrared detection elements as shown in FIG. A method of combining with one optical system having an element is common.
However, in this case, since the light receiving electrodes of the respective pyroelectric infrared detecting elements are arranged in the same package, they must be arranged very adjacent to each other.
Therefore, each pyroelectric infrared detection element shares all of the plurality of optical elements of the optical system, resulting in a detection area as shown in FIG. 9, and each pyroelectric infrared detection element in the entire detection area. Since the detection areas due to the above are mixed, there is a problem that the purpose of identifying the human body existence area cannot be satisfied.
No. 11-8996

  The problem to be solved is that when a plurality of pyroelectric infrared detection elements and an optical system having a plurality of optical elements are combined, each pyroelectric infrared detection element can be combined with an independent optical element, and independent detection is performed. It is a point that cannot have realm.

  The present invention combines a pyroelectric infrared detection element in which a plurality of pyroelectric infrared detection elements as shown in FIG. 4 are housed in one package and an optical system having a plurality of optical elements, to thereby provide a pyroelectric infrared detection element. And an optical shielding system, and a plurality of pyroelectric infrared detection elements are combined with different optical elements, each having an independent detection region.

  The infrared detector of the present invention is a compact and inexpensive because it combines a pyroelectric infrared detection element having a plurality of pyroelectric infrared detection elements stored in the same package, an optical system having a plurality of optical elements, and an infrared shielding plate. There is an effect that an infrared detector can be provided.

  The present invention combines a pyroelectric infrared detection element having a plurality of pyroelectric infrared detection elements contained in one package and an optical system having a plurality of optical elements, and an infrared ray between the pyroelectric infrared detection element and the optical system. By installing a shielding plate, each pyroelectric infrared detection element has a different detection area, and the pyroelectric infrared detection element that emits the detection signal enables identification of the existence area of the human body. .

  FIG. 3 shows an outline of the detection region in the infrared detector of the present invention. FIG. 4 shows an external shape of a pyroelectric infrared detecting element used in the present invention, and FIG. 5 shows an internal circuit diagram. FIG. 1 and FIG. 2 are detailed views of the infrared detection unit in the infrared detector of the present invention. Hereinafter, the present invention will be specifically described with reference to these drawings.

Paste solder is applied by screen printing on the back and back side of the wiring board such as glass epoxy in the pyroelectric infrared detecting element of the TO-5 type package, and an automatic chip mounting machine is applied to the solder application part. The parts such as FET and resistor are mounted and soldered in a reflow furnace, and these parts are mechanically fixed and electrically connected. In addition, since a plurality of pyroelectric infrared detecting elements and circuits are housed in the same package on the wiring board, a plurality of circuit wirings are required.
The component-mounted wiring board that has undergone such a process is soldered, mechanically fixed, and electrically connected to a metal stem having terminals such as a power supply terminal, an output terminal, and a ground terminal.
In addition, pyroelectric ceramic, which is a light receiving portion of the pyroelectric infrared detecting element, is bonded and fixed to the surface of the wiring board with a conductive adhesive. The pyroelectric ceramic is formed with a light receiving electrode on the ceramic surface and a wiring electrode for electrically connecting the pyroelectric ceramic and the wiring board on the back side by a technique such as vacuum deposition. In this case, the pyroelectric infrared detection element has two 1 mm × 1 mm light receiving electrodes arranged at intervals of 1 mm, and has two sets of dual light receiving electrode arrangements in which they are connected in series in the same package. A specification with two circuits having a quad-type electrode arrangement arranged at intervals of 1 mm and outputting each independently is given as an example.
The semi-finished product assembled in this way is welded to a metal cap that is bonded to a window with a filter made of silicon or the like that transmits infrared rays emitted from an object.

A pyroelectric infrared detection element including two dual-type circuits in a TO-5 type package is mounted on a wiring board of the infrared detector. Further, an optical cap having an optical system having a plurality of optical elements is fitted and fixed to the wiring board of the infrared detector with a hook or the like so as to enclose the pyroelectric infrared detection element. In this case, the light receiving electrode 1 of the circuit 1 and the light receiving electrode 2 of the circuit 2 in the pyroelectric infrared detection element receive infrared rays from the detection region 1 and the detection region 2 through the optical system 1 and the optical system 2, respectively. receive. In this embodiment, an optical cap having 10 optical elements with a focal length of 7.5 mm ± 0.3 mm is taken as an example.
Inside the optical cap, an infrared shielding plate is provided between the optical systems 1 and 2 to block the optical path of the infrared light, passes through the optical system 1 and passes through the optical system 2 to the light receiving electrode 2. A stray light prevention measure is provided so as not to enter the light receiving electrode 1.
The detection region obtained by the combination of the pyroelectric infrared detection element, the optical systems 1 and 2 and the optical cap provided with the infrared shielding plate is such that the light receiving electrode 1 is the detection region 1 and the light receiving electrode 2 is the detection region 2. Each has an independent detection area.
The light receiving electrodes 1 and 2 are connected to independent pyroelectric infrared detection circuits, and output independently of each other, so that the region where the human body exists is identified by the signal output obtained from each circuit. Is possible.

  The infrared detector manufactured by such a method is integrated by making the optical systems 1 and 2 cap-shaped, and the pyroelectric infrared detecting element in which two pyroelectric infrared detecting element circuits are stored in the same package. In order to realize a plurality of independent detection regions as in the present invention, two pyroelectric infrared detection elements each having one dual type light receiving electrode in a TO-5 type package are provided. It is more compact than the case where it is used, and the work time for assembling the infrared detection unit composed of the pyroelectric element and the optical system is also halved, enabling the existence area identification of the human body by having an independent detection area, and increasing the cost. It was possible to produce a suppressed infrared detector.

  In the embodiment, the case of two independent detection areas using a pyroelectric infrared detection element with two circuits is given as an example, but the present invention can also be applied to applications for further subdividing the detection areas. For example, as an example of detecting four independent detection areas using a pyroelectric infrared detector with four circuits, FIG. 10 shows an external shape diagram of the pyroelectric infrared detector with four circuits, FIG. Reference numeral 12 denotes an infrared detector and a cross-sectional view of the infrared detector, and FIG. 13 shows a detection region.

It is the figure which showed the outline | summary of the infrared detection part of the infrared detector in this invention. It is the figure which showed the infrared detection part cross section of the infrared detector in this invention. It is the figure which showed the detection area | region in an Example. It is the figure which showed the external appearance and internal structure of the pyroelectric infrared detection element which stored the several pyroelectric infrared detection element in the same package. It is the figure which showed the internal circuit of the pyroelectric infrared detection element of FIG. It is the figure which showed the external appearance and light receiving electrode arrangement | positioning of a general pyroelectric element. It is the figure which showed the outline | summary of the infrared detection part of the infrared detector using a general pyroelectric element. It is the figure which showed the detection area | region of the general infrared detector. It is the figure which showed the detection area | region of the infrared detector using the pyroelectric infrared detector of FIG. It is the figure which showed the external appearance and internal structure of the pyroelectric infrared detection element containing 4 circuits. It is the figure which showed the outline of the infrared detection part of the infrared detector at the time of using the pyroelectric infrared detection element containing 4 circuits in this invention. It is the figure which showed the infrared detection part cross section of the infrared detector at the time of using the pyroelectric infrared detection element containing 4 circuits in this invention. It is a figure which shows the detection area | region at the time of using the pyroelectric infrared detection element containing 4 circuits.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pyroelectric infrared detection element 2 Optical element 3 Optical cap 4 Photosensitive electrode 4-A Photosensitive electrode A
4-B Photosensitive electrode B
4-C Photosensitive electrode C
4-D Photosensitive electrode D
DESCRIPTION OF SYMBOLS 5 Wiring board 6 Stem 7 Metal cap 8 Infrared transmission filter 9 Detection area 9-A Detection area in light receiving electrode A 9-B Detection area in light receiving electrode B 9-C Detection area in light receiving electrode C 9-D In light receiving electrode D Detection area 10 Infrared shielding plate 11 FET
12 Load resistance 13 Pyroelectric ceramic

Claims (1)

  A plurality of pyroelectric infrared detection elements and a plurality of optical elements in an infrared detector combined with a pyroelectric infrared detection element that receives infrared rays emitted from the human body via an optical system and generates a signal output according to the change. An infrared detector characterized by combining an optical system having a plurality of pyroelectric infrared detection elements, each having an independent detection region, and identifying a region where a human body emitting infrared rays exists from the signal output.

Images