JPS6125298B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a pyroelectric infrared detector,
This allows a highly accurate detector to be easily manufactured.

Conventionally, this type of detector has a pyroelectric element 1 having vapor-deposited electrodes 2 and 3 on the upper and lower sides, as shown in Fig. 1, mounted on pillars 5 and 7 which also serve as lead terminals, and a FET 4 for impedance conversion including the element 1. case 100
It consists of something covered with Here 101 is the base,
8 is a window material for infrared incidence, and 6 is a lead terminal formed by the pillars 5 and 7.

FIG. 2 shows another conventional detector in which the pyroelectric element 1 is provided on a support 9 and the FET 4 is provided on another support 91.

Moreover, FIGS. 3a and 3b show these electrical connection diagrams.

In order to provide temperature compensation in such a configuration, it can be done outside the case 100 or
A new means will be established within the country. However, when looking at the manufacturing process, these structures are not suitable for mass production and have the disadvantage of increasing manufacturing costs.

The present invention eliminates these drawbacks and will be described below with reference to an embodiment of FIGS. 4 to 7.

In the figure, 10 and 11 are pyroelectric elements and window materials corresponding to 1 and 8 in FIG. 12 (121,1
22) has a step 13, and the step 13 side is the adhesive surface for the pyroelectric element 10, and 900 and 902 have support stands 121 and 122 that integrate the pyroelectric element 10. This is a pyroelectric unit. Note that unit 902 is an inverted version of unit 900, and is composed of substantially the same components. 90
1 is a reflector plate, 13 is a substrate with terminals 5 to 7 attached to the impedance converter 4, 14 is a metal plate, 15 is a support for the substrate 13, 16 is a cushion material, 17 is a cover plate, and 18 is a cylinder made of insulating material. , 19 is a cylindrical case made of metal having a bent portion 191 at one end and an engagement hole 192 at the other end. Reference numeral 20 represents a retaining spring, a portion of which enters the engagement hole 192 and holds the cover plate 17, as shown in FIG. 8, and 21 represents a retainer for the window material 11.

In the embodiment configured in this way, the window material 11
is fixed to the holding base 21 and inserted from one side of the cylindrical case 19 as shown in FIG. 4, then the cylinder 18 is inserted, and the pyroelectric unit 900,
Reflector plate 901, pyroelectric unit 902, metal plate 14
Insert in this order.

Further, the terminals 5 to 7 of the impedance converter 4 attached to the substrate 13 are connected to the support base 15 and the cushion material 1.
6. Protrude outward through the cover plate 17, and in this state, house it in the cylindrical case 19 as shown in FIG. By combining them, the present detector is formed.

Here, the feature based on this configuration is that the support base 12 is provided with a stepped portion 13, and the pyroelectric element 10 is adhered to the surface having the stepped portion 13, so that the diameter of the pyroelectric element 10 is reduced. Even if it is large, it is easy to cut the unnecessary portion of the element 10 along the outer edge of the support base 12 as long as it is within the diameter of the side of the support base 12 that does not have the stepped portion 13. This will not affect others.

Furthermore, the pyroelectric element 10 has two support stands 12 (12
1, 122), and the two pyroelectric units 900, 90 formed in this way
2 are installed on both sides of the reflector plate 901 with the front and back sides reversed, so that the unit 900 functions as an original infrared detector.
Note that the pyroelectric units 900 and 902 are the sixth units, respectively.
When the pyroelectric units 900 and 902 are stacked on top of each other, the support body 122 shown in the figure is not required.
Reflection plates 901 may be provided at regular intervals between 0 and 902. Also, the pyroelectric unit 90
2 changes with respect to temperature under the same conditions as 900, and has the opposite polarity, so it cancels out the change in 900 and is used for temperature compensation. In addition, the rear unit including the impedance converter 4 (supporting base 1
5. The cushion material 16 and the cover plate 17) can be formed in a stacked manner, and manufacturing is easy because it is only necessary to engage the retaining spring 20 in this state or to bend the cover plate 17 side of the cylindrical case 19 inward. be.

In addition, the original infrared detection and temperature compensation unit 9
00 and 902 can be the same, so all you need to do is be careful about how to insert them into the cylinder 18.

Since the front side support stand 121 of the pyroelectric unit 900 for infrared detection can be connected to the cylindrical case 19 through the holding stand 21, the cylindrical case 1 can be connected to the cylindrical case 19 by the cover plate 17.
9 can be completely shielded.

In addition, by stacking them with opposite polarity, it is possible not only to compensate for temperature, but also to cancel out noise voltages such as vibrations, noise, and impact caused by the piezoelectric characteristics of these elements.

In addition, due to the stacking method, many closed rooms are created, and abnormal voltage is generated due to the expansion and contraction of the air inside due to environmental temperature changes. It is necessary to provide ventilation holes in the components.

9 and 10 show an example in which the metal plate 14 and the reflective plate 901 are provided with ventilation portions a, and FIG. 11 shows the electrical configuration of this detector.

As is clear from the above embodiments, the present invention involves inserting two pyroelectric elements sandwiching a reflective plate having a vent inside a cylindrical case, and inserting a cushioning material between each of the reflective plate and the pyroelectric element. Since it is attached by inserting it, it is less affected by vibration, the pyroelectric element on the back side prevents the effect of infrared rays, and the ventilation part prevents expansion and contraction due to temperature changes.

[Brief explanation of the drawing]

Figures 1a and 2 are cross-sectional views of conventional infrared detectors, Figure 1b is a front view of Figure 1a, and Figures 3a and b.
is an electrical wiring diagram, FIG. 4 is a sectional view of an infrared detector in an embodiment of the present invention, FIGS. 5 to 7 are assembly process diagrams of component parts, and FIG. 8 is a perspective view of component parts.
9 and 10 are plan views of the component parts, and FIG. 11 is an electrical wiring diagram. 10...Pyroelectric element, 12...Support stand.

Claims (1)

[Claims] 1. A hollow cylindrical case having a window material through which infrared rays can pass, and a first pyroelectric element installed within the cylindrical case, which senses the infrared rays from the window material and generates an electric signal corresponding to the temperature of the infrared rays. a reflector plate attached to the first pyroelectric element to reflect the infrared rays and having a vent, and a reflector plate attached to the reflector plate to compensate for the infrared temperature portion in the cylindrical case. a second pyroelectric element that generates an electric signal, and these cylindrical cases,
An infrared detector comprising a first pyroelectric element, a reflector, and a vibration-preventing buffer provided on each of the second pyroelectric elements.