JPS59202036A - Infrared ray detector - Google Patents

Abstract

PURPOSE:To improve the accuracy in the temperature measurement by arranging first and second vibrators for vibrating first and second opposed bodies each having an infrared rays transmitting section and non-transmitting section so that respective surfaces thereof vertical to the directions of vibration are positioned on the same plane. CONSTITUTION:First and second opposed bodies 16 and 17 are arranged in an infrared rays incident area and each have an infrared rays transmitting section and non-transmitting section. The first and second opposed bodies are vibrated cyclically with first and second vibrators 34 and 35 in such a manner as to repeat the state of the infrared rays transmitting section and the non- transmitting section of the first opposed body overlapping the non-transmitting section and the transmitting section of the second opposed body respectively and the state of the transmitting sections and non-transmitting sections thereof overlapping each other alternately. The first and second vibrators 34 and 35 are arranged on a fixed based 36 so that surfaces A and B of the first and second vibrators 34 and 35 vertical to the directions (a) and (b) of vibration respectively are positioned on the same plane to prevent possible deviation between the first and second opposed bodies 16 and 17.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an infrared detector for detecting, for example, the temperature of a detected part using infrared rays.

(Example) Prior Art Recently, an infrared detector as shown in FIG. 1 has been proposed.

(1) is a pyroelectric infrared detector made of lithium tantalate (LiTa05J single crystal), which has front and back electrodes (2) and (3) and generates a charge according to the amount of change in incident infrared rays;
(4) is a metal support made of phosphor bronze, etc., (5) is a conductive adhesive, and (6) is a shield body that shields the infrared detector (1) from external noise C2, the front surface of which is Detection body (m: Opposed openings (7) are formed.

(8) is a storage body consisting of a metal cap (9) and a header (10), and the support stand (4) is fixed on the header (<10) inside the storage body. (11) is directly planted on the header (10)≦2, and the support base (4)
and a ground terminal that is electrically connected to the back electrode (3) via an adhesive (5), (12 is installed on the ladder 00 above) via an insulating material, and is electrically connected to the front electrode (2). g, a signal terminal for extracting the electric charge generated on the detection body (11) to the outside;
9) is an infrared transmission filter that closes the two openings on the front surface and the openings.

(15) is the container C located inside the storage body (8), and the opening α
This is an intermittent means for intermittent infrared rays from a detected part outside the storage body (8) passing through J. The intermittent means (2, (L6) and (17) are arranged parallel to each other in the incident area of the infrared rays to the detecting body (1), that is, between the detecting body (1) and the open housing powder. The first and second opposing bodies are arranged in a planar shape.

The first and second opposing bodies (L6) and (I7) are made of an infrared non-transparent material such as aluminum, as shown in FIGS. 2a and 2b, respectively. Second, a plurality of first infrared non-transmissive portions αa, discharge, etc. and second infrared non-transmissive portions (11, C1l, etc.) extending in a fan-shaped linear shape are formed, and the first infrared non-transmissive portions (11, C1l, . Transparent part shout, αa...
・ between each and the second infrared non-transmissive part old e, C19-
The first infrared transmitting portion (20), (
201... and the second infrared transmitting part (211% (211
... is formed. The non-transparent part αg, (181
... and (19, C9... and the above-mentioned transparent part (20),
t2G... and (21), (211... both have the same dimensions and shape, and the widths Wl and W2 are respectively 100/Im,
120. It is am.

(22) is a first vibrating body for vibrating the first opposing body (L61), and behind the vibrating body (FIG. 1) is a vibrating body for vibrating the second opposing body α as shown in FIG. A second vibrating body (c) is arranged to vibrate the vibration. The structure of the first and second vibrating bodies (c) is as follows. The conductor becomes the central electrode C2, and on both sides of the electrode (24) are polarized piezoelectric materials (e) made of barium titanate, lead zirconate titanate, etc. The piezoelectric body (the uppermost surface of the piezoelectric body) is
Second, a surface electrode (c) made of silver or the like is formed.

The first and second opposing bodies 06) and αη are respectively attached to the right ends of the first and second vibrating bodies (22+, (23+) through insulating first and second bases 0η, (2). ing.

(29) and (7) are respectively arranged on the header (10) via two insulating layers c1υ, and the first and second vibrating bodies (2
4. (c) is fixedly supported, and electrically connected to the surface electrodes (2e, (2E9) of each vibrating body (22,
The second fixed base, □□□, and field are first and second vibration terminals respectively implanted in the header aα via an insulating material, and the first vibration terminal is connected to the center of the first vibrator (221). Electrode t2 (a)
and the second fixed base are connected, and the second vibration terminal 1
33 is connected to the first fixing base C29) and the center electrode (C) of the second vibrating body.

A constant voltage of -20V is applied to the first vibration terminal, and a voltage of +10V is alternately and periodically applied to the second vibration terminal.

When a voltage of +10V is applied, C is applied to the first vibrating body (2).
In 21, the outer piezoelectric body (2) contracts and the inner piezoelectric body (24) expands, so the first vibrating body (2 snores, direction of arrow a≦2 deflections. Also, the above $2 vibrating body (Zii) In the second case, the inner piezoelectric body (c) extends and the outer piezoelectric body 12
5) is contracted, and therefore the second vibrating body (C) is bent in the direction of the arrow C.

On the other hand, when a voltage of -1 ov is applied to the second vibrating terminal, the first and second vibrating bodies bend in the direction a, where (c) is the opposite of the above.

As a result, the first and second vibrating bodies (2, (c) vibrate periodically in opposite directions to each other, and based on such vibrations, the first infrared transmitting part (2o) of the first opposing body ae , Kanji... and the first infrared non-transmissive part (181, (1s...) and the second infrared non-transmissive part (L) of the second opposing body (17), Kanji... and the second infrared transmissive part ( 21), (7!D... are superimposed on each other, and the infrared transmitting part (2U), (2■...,
En, (21)... and infrared non-transparent part (2),
The state in which αa..., α■, 0... are superimposed is repeated alternately C, that is, the infrared rays from the external detected part that have passed through the aperture (13) are intermittently incident on the detection object (111 = Therefore, the amount of incident infrared rays on the detecting body (1) changes, and an electric charge is generated depending on the temperature of the detected part.

By the way, the first and second vibrating bodies (221, Q: 4t-
x central electrode (2. It is most preferable to have a completely symmetrical structure with respect to 2. In other words, in such a structure, the central electrode 04
) The average coefficient of thermal expansion of the respective structures on both sides is the same, so that even if the ambient temperature changes, the first
, of the second vibrating body (2 (to)) similarly expands and contracts, so it does not bend undesirably.In a state where there is no such deflection, the first and second vibrating bodies (22+, When the vibration occurs, the above-mentioned two superpositions are reliably repeated twice, and infrared rays are reliably interrupted, thereby generating a desired charge from the detection object (1) according to the temperature of the detected part, with high accuracy. Temperature measurements can be performed.

However, it is actually extremely difficult to obtain a completely symmetrical structure as described above. For example, it is extremely difficult to obtain a completely symmetrical structure as described above.
It is difficult to match the thicknesses of 251 and the surface electrode (26) well, and the average coefficient of thermal expansion of the structures on both sides of the center electrode (2) will be different.
The second vibrating body (c) undesirably bends due to changes in ambient temperature.

Therefore, even if the first and second vibrating bodies (22), (23) of the infrared detector (2) are bent due to changes in the ambient temperature, the first and second opposing bodies (16), The first and second vibrating bodies (2L (23+) are to the same extent in the same direction a or b due to the ambient temperature change However, due to the change in ambient temperature l2, the first and second vibrating bodies (22+, (23) are deflected at 52, and the first and second opposing bodies u6) , 0η actually shifts as shown in detail in FIG.

That is, since the first and second vibrating bodies are spaced apart on the first and second fixed bases I29), which serve as their fulcrums, respectively, and the header α0), the first and second vibrations are When the body az, @ bends due to a change in ambient temperature (for example, from the position of the solid line C2 in the a direction to the position of the broken line), the first and second opposing bodies (1ta, an are the dimensions l when referring to their center lines a, d) It's just off.

Here, in a state where such a shift occurs, the first, m
2. When the vibration of the vibrating body (27J, (c) ≦ 2, the two superpositions described above are not performed reliably, the intermittent infrared rays cannot be reliably performed, and due to this 22, the detection object (1) The desired charge according to the temperature of the detection part is not generated,
Accurate temperature measurement cannot be performed.

1. OBJECTS OF THE INVENTION It is an object of the present invention to ensure that infrared rays are intermittent ≦2 times, so that, for example, when measuring temperature, such temperature measurement can be performed with high precision.

B) Structure of the Invention In order to achieve the above object, the infrared detector of the present invention includes an infrared detecting body that generates an electric charge according to the amount of change in incident infrared light, an infrared transmitting part disposed in the infrared incident area to the detecting body, and an infrared transmitting part disposed in the infrared incident area to the detecting body. first and second opposing bodies both having non-transparent parts; a state in which the infrared transparent part and the infrared non-transparent part of the first opposing body overlap with the infrared non-transmissive part and the infrared transparent part of the second opposing body, respectively; First and second vibrations that vibrate the first and second opposing bodies, respectively, in order to alternately repeat a state in which the infrared transmitting parts and the non-infrared transmitting parts of the first and second opposing bodies overlap each other. The first and second vibrating bodies are arranged such that the two surfaces perpendicular to the respective vibration directions of the first and second vibrating bodies are on the same plane (two positions). .

(E) Embodiment 1 An infrared detector according to an embodiment of the present invention will be explained based on FIGS. 5 and 6. Incidentally, the same parts as in the conventional example are denoted by the same reference numerals, and the explanation thereof will be omitted.

(to) and (to) are first and second vibrating bodies for causing periodic vibration of the first and second opposing bodies attached to the lower end and upper end of the right side, respectively; , the second vibrating body is the same as the conventional one except that its pressure's core body curve ω is polarized in the p and p' directions, respectively. In the above first and second vibrating body examples, the respective vibration directions a and bl in (to) and two perpendicular planes, A and B, are located on the same plane g; The body is a metal fixing base for fixedly supporting the body, and the first and second vibrating bodies (b) and the central electrode (goods) of c's are connected to the first vibrating terminal. the above?
The fixed base (7) is connected to the J&2 swing terminal □□□.

Thus, a constant voltage of 20 V is applied to the $1 moving terminal diagram [2], and a voltage of ±10 V is alternately applied to the second moving terminal C.

When a voltage of +IOV is applied, the first and second vibrating bodies (2) are bent in the a and b directions, respectively, and when a voltage of -10V is applied, the first and second vibrating bodies (2) are bent in the a and b directions, respectively. ) are deflected in directions b and a, respectively, and as a result, the first and second vibrator diagrams (to) vibrate periodically as in the conventional case, and infrared rays are intermittent.

Here, the fulcrums of C2, the first and second vibrating bodies, and C, respectively, are on the same straight line with a fixed union and overlap vertically, so the first and second moving bodies G are rotated □□□ Even if it decreases due to the change in the surrounding fA degree, the first and second opposing bodies α6, ul)
There will be no discrepancy between the two.

Therefore, in a state where such deflection occurs, when the first and second vibrating bodies vibrate, the infrared rays are reliably intermittent, and the desired signal is transmitted from the detecting body (1) to the detected part according to the temperature. A charge is generated.

(f) Effects of the Invention As is clear from the above explanation, according to the present invention (=), infrared rays can be reliably interrupted even when ambient temperature changes, so for example, in temperature measurement, it can be done with high precision. be able to.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a recently proposed infrared detector, Figures a and b are plan views of the first and second opposing bodies of the detector, respectively, and Figure 3 shows the same detector as in Figure 1. FIG. 4 is a plan view of the main part of the detector as seen from the direction of the arrow (■), and FIG. 6 is a plan view of the main part of the detector as seen from the direction of the arrow (■). (11...pyroelectric infrared detector, (Le, αD...
・First and second opposing bodies, (b), (to)...first and second vibrating bodies. 0θ473 Light operation control eye y8. −

Claims (1)

[Claims] (1) An infrared detector that generates a charge according to the amount of change in incident infrared rays, first and second opposing bodies that are arranged in an infrared incident region to the detector and have both an infrared transmitting part and an infrared non-transmissive part, and the second opposing body. The state in which the infrared transmitting part and the infrared non-transmitting part of the first opposing body overlap with the infrared non-transmitting part and the infrared transmitting part of the second opposing body, and the infrared transmitting part and the infrared non-transmitting part of the first and second opposing bodies overlap, respectively. In order to alternately repeat the state in which the transparent parts overlap each other, first and second vibrating bodies are provided which respectively vibrate the first and second facing bodies, and each of the first and second vibrating bodies vibrates. 2. An infrared detector characterized in that the first and second vibrating bodies are arranged so that surfaces perpendicular to the vibration direction g are located on the same plane.