Detection device

Abstract

[Problem] To provide a detection device that makes it possible to reduce the influence of disturbance light and improve the accuracy of measurement of infrared light of interest. [Solution] This detection device comprising a detection unit 10 that detects infrared light and a determination unit 30 that estimates the light quantity of infrared light of interest. The detection unit 10 comprises a first infrared light detection unit 11 and a second infrared light detection unit 20. The first infrared light detection unit 10 comprises a band-pass filter 14 that is disposed between a first detection unit 13 and a first entrance unit 12, and transmits first infrared light of interest. The second infrared light detection unit 20 comprises an incoming light adjustment unit 25 that is disposed between a second detection unit 23 and a second entrance unit 22. The incoming light adjustment unit 25 comprises a first reflection mirror 26, a second reflection mirror 27 that reflects second infrared light of interest, and a movement mechanism that moves the first reflection mirror 26 and the second reflection mirror 27 between a reflection position and a retraction position.

Description

Technical Field

[0001] The present invention relates to a detection device.

Background Art

[0002] Gases such as ammonia and methane gas emit infrared rays of a specific wavelength, and also absorb infrared rays emitted from other objects. Therefore, the presence of gas can be grasped by taking a picture of the infrared rays in the area where the gas exists. For this reason, an infrared camera may be used for detecting gas leakage or the like in a plant or the like.

[0003] By the way, the infrared rays (infrared light) received by the infrared camera include not only infrared rays (target infrared rays) having a wavelength related to the gas to be detected such as gas leakage but also infrared rays having different wavelengths. When taking a picture of light including a plurality of wavelengths, a filter (band-pass filter) that transmits light of the target wavelength is used (see Patent Document 1). By taking a picture using such a filter, the target infrared rays can be efficiently taken, so that gas leakage or the like can be effectively detected.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when there is disturbing light including infrared rays with a wide range of frequencies such as sunlight, even when taking pictures of the target infrared rays using a filter, it is affected by the disturbing light. That is, since the light including infrared rays having the same wavelength as the target infrared rays in the disturbing light is taken in a state of overlapping with the target infrared rays, there is a possibility that gas leakage or the like cannot be appropriately grasped.

[0006] In view of the above circumstances, the present invention aims to provide a detection device that can reduce the influence of ambient light and improve the measurement accuracy of the target infrared radiation. [Means for solving the problem]

[0007] The detection device of the present invention is a detection device for detecting a target infrared light of a predetermined wavelength, comprising: a detection unit for detecting infrared light; and a determination unit for estimating the amount of target infrared light based on the infrared light detected by the detection unit, wherein the detection unit comprises a first infrared detection unit and a second infrared detection unit, wherein the first infrared detection unit comprises: a first incident unit for receiving light containing infrared light; a first detection unit for detecting infrared light contained in the first incident light incident from the first incident unit; and a bandpass filter that transmits a first target infrared light, disposed between the first detection unit and the first incident unit, wherein the second infrared detection unit contains The device comprises a second incident unit for injecting light, a second detection unit for detecting infrared rays contained in the second incident light injected from the second incident unit, and an incident light adjustment unit positioned between the second detection unit and the second incident unit, wherein the incident light adjustment unit comprises a total light supply unit for supplying all of the second incident light to the second detection unit, a second target infrared supply unit for supplying the second target infrared rays contained in the second incident light to the second detection unit, and a movement mechanism for moving the total light supply unit and the second target infrared supply unit between a supply position located on the optical axis of the second incident light and a retracted position set back from the optical axis of the second incident light. [Effects of the Invention]

[0008] According to the present invention, since the first target infrared and the second target infrared can be detected simultaneously, two substances present in the object being measured can be detected at the same time. Furthermore, by directing all of the second incident infrared into the second detection unit, the influence of ambient light can be assessed, thereby improving the detection accuracy of substances present in the object being measured based on the first target infrared and the second target infrared. [Brief explanation of the drawing]

[0009] [Figure 1]This is a schematic diagram of the detection device 1 of this embodiment, where (A) is a front view and (B) is a schematic cross-sectional view taken along line BB in Figure 1(A). [Figure 2] (A) is a schematic cross-sectional view taken along the line IIA-IIA in Figure 1(B), and (B) is a schematic cross-sectional view taken along the line IIB-IIB in Figure 1(B). [Figure 3] This is a schematic diagram of an incident light adjustment unit 25 in which a movable member 29 moves in a straight line, where (A) is a schematic diagram of the incident light adjustment unit 25 viewed from above with the first reflective mirror 26 positioned at the reflection position, (B) is a view from arrow BB in (A), (C) is a schematic diagram of the incident light adjustment unit 25 viewed from above with the second reflective mirror 27 positioned at the reflection position, and (D) is a schematic diagram viewed from arrow DD in (C). [Figure 4] This is a schematic diagram of an incident light adjustment unit 25 in which a movable member 29 rotates, where (A) is a schematic diagram of the incident light adjustment unit 25 viewed from above with the first reflective mirror 26 positioned at the reflection position, (B) is a view of (A) as indicated by arrow BB, (C) is a schematic diagram of the incident light adjustment unit 25 viewed from above with the second reflective mirror 27 positioned at the reflection position, (D) is a view of (C) as indicated by arrow DD, and (E) is a view of (A) as indicated by arrow EE. [Figure 5] (A) is a schematic diagram illustrating the state in which the first infrared detection unit 11 is detecting synchrotron radiation from the object A being measured, and (B) is a schematic diagram illustrating the state in which the second infrared detection unit 20 is detecting synchrotron radiation from the object A being measured. [Figure 6] (A) is a cross-sectional view of the detection device 1 of this embodiment, equipped with a laser light source 35, as seen by the arrow along line BB in Figure 1(A), and (B) is a cross-sectional view of (A) as seen by the arrow along line BB. [Figure 7] (A) is a front view of the detection device 1 of this embodiment, which is equipped with a visible light imaging unit 60; (B) is a schematic front view of the incident light adjustment unit 25 when a transmissive window 28 is provided on a linearly moving member 29; and (C) is a schematic front view of the incident light adjustment unit 25 when a transmissive window 28 is provided on a rotationally moving member 29. [Figure 8]This is a schematic diagram illustrating the detection device 1 of another embodiment, where (A) is a front view and (B) is a schematic cross-sectional view of (A) along line BB. [Figure 9] (A) is a schematic cross-sectional view of the IXA-IXA line in Figure 9(B), and (B) is a schematic cross-sectional view of the IXB-IXB line in Figure 9(B). [Figure 10] (A) is a schematic diagram of the detection device 1 of another embodiment equipped with a laser light source 35, (B) is a view of (A) along the line BB, and (C) is a view of (B) along the line CC. [Figure 11] This is a schematic diagram illustrating the data obtained based on infrared radiation detected by the first detection unit 13 and the second detection unit 23. (A) is a schematic diagram illustrating the spectral characteristics obtained by point measurement, and (B) is a schematic diagram illustrating the two-dimensional image obtained by surface measurement. [Figure 12] This diagram illustrates a method for eliminating the effects of ambient light. (A) is a schematic diagram for point measurements, and (B) is a schematic diagram for surface measurements. [Figure 13] This diagram illustrates the changes in measurement data when laser light is irradiated. (A) is a schematic diagram of point measurement, and (B) is a schematic diagram of surface measurement. [Modes for carrying out the invention]

[0010] The detection device of this embodiment is a detection device that detects infrared radiation, and by detecting infrared radiation of a predetermined wavelength, it can identify substances present in the object to be detected. The substances present in the object to be detected by the detection device of this embodiment are not particularly limited, but it is suitable for detecting gases that cannot be seen. For example, ammonia, methane gas, propane gas, propylene and other hydrocarbon gases can be considered substances present in the object to be detected.

[0011] <Detection device 1 of this embodiment> The detection device 1 of this embodiment will be described based on the drawings. As shown in Fig. 1, the detection device 1 of the present embodiment includes a detection unit 10 that detects infrared rays, a determination unit 30 that estimates the light amount of target infrared rays based on the infrared rays detected by the detection unit 10, and a recognition unit 40 that determines a detection target based on the light amount of the target infrared rays estimated by the determination unit 30.

[0012] Note that the detection device 1 of the present embodiment may be configured such that the detection unit 10 is housed in the case 2, and the determination unit 30 and the recognition unit 40 are also provided in the case 2 (see Fig. 1(B)), or the detection unit 10 and the determination unit 30 may be housed in the case 2, and the recognition unit 40 may be provided outside the case 2. Further, only the detection unit 10 may be provided in the case 2, and the determination unit 30 and the recognition unit 40 may be provided outside the case 2. When the determination unit 30 or the recognition unit 40 is provided outside the case 2, the determination unit 30 or the recognition unit 40 may be electrically connected by wire, or data transmission may be performed by wireless communication.

[0013] <Detection unit 10> As shown in Fig. 1(B), the detection unit 10 includes a first infrared detection unit 11 and a second infrared detection unit 20.

[0014] <First infrared detection unit 11> As shown in Fig. 1(B) and Fig. 2(A), the first infrared detection unit 11 includes a first incident unit 12 that makes light incident on the first detection unit 13 from the outside (hereinafter simply referred to as "external light") (hereinafter simply referred to as "first incident light"). This first incident unit 12 has, for example, a lens that makes the first incident light parallel or condenses it. The first incident light includes light of various wavelengths included in the external light and is light including infrared rays of the wavelength to be detected by the first infrared detection unit 11. Further, the first incident unit 12 may not be provided with a lens or the like having the above-described function. When the first incident unit 12 is not provided with a lens or the like having the above-described function, a lens or the like having the above-described function may be separately provided between the band-pass filter 14 and the first incident unit 12.

[0015] A band-pass filter 14 is provided between the first incident part 12 and the first detection part 13. This band-pass filter 14 has a function of passing infrared light of a predetermined wavelength (hereinafter simply referred to as "first target infrared light").

[0016] The first detection part 13 has a function of detecting infrared light. As shown in FIG. 1(B), since the first target infrared light that has passed through the band-pass filter 14 is incident on the first detection part 13, the first detection part 13 can detect the first target infrared light included in the first incident light. That is, the first detection part 13 can detect the light amount of the first target infrared light included in the first incident light. The first detection part 13 is, for example, a general infrared camera or infrared sensor, etc., but is not particularly limited as long as it can detect the light amount of the first target infrared light. Also, the first detection part 13 may be provided with a lens or the like for condensing the first target infrared light that has passed through the band-pass filter 14. When a lens for condensing the first target infrared light is not provided in the first detection part 13, a lens for condensing the first target infrared light may be separately provided between the band-pass filter 14 and the first detection part 13.

[0017] Also, as shown in FIGS. 1(B) and 2(A), the first incident part 12, the band-pass filter 14, and the first detection part 13 are provided so as to be linearly arranged. That is, the first incident part 12, the band-pass filter 14, and the first detection part 13 are arranged so that the optical axis 12s of the first incident light incident from the first incident part 12, the optical axis 14s of the band-pass filter 14, and the light receiving axis 13s of the first detection part 13 are coaxial.

[0018] Therefore, as shown in FIG. 5(A), when external light including infrared light radiated by the measurement target A or infrared light passing through the position of the measurement target is incident from the first incident part 12, only the first target infrared light can be made incident on the first detection part 13 by passing through the band-pass filter 14.

[0019] <Second infrared detection part 20> As shown in Figures 1(B) and 2(B), the second infrared detection unit 20 includes a second incident unit 22 that directs external light towards the second detection unit 23 as incident light (hereinafter simply referred to as "second incident light"). This second incident unit 22 has, for example, a lens that makes the second incident light parallel or focuses it. The second incident light contains light of various wavelengths included in the external light and is light that contains infrared light of the wavelength to be detected by the second infrared detection unit 20. It is also not necessary to provide a lens with the above-described function in the second incident unit 22. If a lens with the above-described function is not provided in the second incident unit 22, a lens with the above-described function that makes the second incident light parallel may be separately provided between the incident light adjustment unit 25 and the second incident unit 22.

[0020] As shown in Figure 2(B), an incident light adjustment unit 25 is provided between the second incident unit 22 and the second detection unit 23. This incident light adjustment unit 25 has the function of reflecting the second incident light and supplying the reflected light to the second detection unit 23. This incident light adjustment unit 25 has a first reflection mirror 26, a second reflection mirror 27, a movable member 29 on which the first reflection mirror 26 and the second reflection mirror 27 are provided, and a moving mechanism for moving the movable member 29 (see Figure 3). The moving mechanism also has the function of a position adjustment mechanism as referred to in the claims.

[0021] The first reflective mirror 26 has a reflective surface 26a that reflects the second incident light incident from the second incident section 22 and supplies the reflected light to the second detection section 23. Specifically, the first reflective mirror 26 has a reflective surface 26a that reflects light of all wavelengths (or infrared light of all wavelengths) of the second incident light incident from the second incident section 22. Furthermore, the second reflective mirror 27 has a reflective surface 27a that supplies only the reflected light of a predetermined wavelength from the second incident light incident from the second incident section 22 to the second detection section 23. Specifically, the second reflective mirror 27 has a reflective surface 27a that supplies only the infrared light of a predetermined wavelength (hereinafter simply referred to as "second target infrared light") from the infrared light contained in the second incident light to the second detection section 23.

[0022] The first reflective mirror 26 and the second reflective mirror 27 are installed on the movable member 29, and when the movable member 29 moves by the moving mechanism, the first reflective mirror 26 and the second reflective mirror 27 move between the reflection position and the retracted position. Specifically, when the movable member 29 moves and the first reflective mirror 26 is positioned in the reflection position, the second reflective mirror 27 is positioned in the retracted position, and when the first reflective mirror 26 is positioned in the retracted position, the second reflective mirror 27 is positioned in the reflection position. The reflection position is the position where the first reflection mirror 26 and the second reflection mirror 27 are positioned on the optical axis 22s of the second incident light incident from the second incident section 22. When the first reflection mirror 26 and the second reflection mirror 27 are positioned at this position, the reflection position is the position where the angles θ1 and θ2 (see Figure 2(B)) made by the reflective surfaces 26a and 27a with respect to the optical axis 22s of the second incident light are 45°. The retracted position is the position where the first reflective mirror 26 and the second reflective mirror 27 are retracted from the optical axis 22s of the second incident light incident from the second incident section 22. In other words, the retracted position is the position where, when the first reflective mirror 26 and the second reflective mirror 27 are positioned, the second incident light does not incident on the reflective surfaces 26a and 27a.

[0023] For example, as shown in Figure 3, when the moving member 29 moves in a straight line, the moving member 29 is installed so that its direction of movement is perpendicular to the optical axis 22s of the second incident light. The first reflective mirror 26 and the second reflective mirror 27 are then arranged to be aligned along the direction of movement of the moving member 29 (left and right in Figures 3(B) and (D)). Furthermore, the first reflective mirror 26 and the second reflective mirror 27 are installed on the moving member 29 such that their respective reflective surfaces 26a and 27a are flush and the angles θ1 and θ2 with respect to the optical axis 22s of the second incident light are 45° (see Figure 2(B)). Note that in Figure 3, (A) and (B) show the state where the first reflective mirror 26 is in the reflection position and the second reflective mirror 27 is in the retracted position, while in Figure 3, (C) and (D) show the state where the second reflective mirror 27 is in the reflection position and the first reflective mirror 26 is in the retracted position.

[0024] Furthermore, as shown in Figure 4, when the movable member 29 rotates, the rotation axis 29s of the movable member 29 is set such that the angle θ3 that its central axis makes with respect to the optical axis 22s of the second incident light is 45° (see Figure 4(E)). The first reflective mirror 26 and the second reflective mirror 27 are arranged side by side along the rotation direction (i.e., the circumferential direction) of the movable member 29 (see Figures 3(A) to (D)). Moreover, the first reflective mirror 26 and the second reflective mirror 27 are set on the movable member 29 such that their respective reflective surfaces 26a and 27a are flush with each other and the normal directions of their reflective surfaces 26a and 27a are parallel to the rotation axis 29s of the movable member 29. Figures 4(A), (B), and (E) show the state where the first reflective mirror 26 is in the reflective position and the second reflective mirror 27 is in the retracted position, while Figures 4(C) and (D) show the state where the second reflective mirror 27 is in the reflective position and the first reflective mirror 26 is in the retracted position.

[0025] The second detection unit 23 has the function of detecting infrared light. As shown in Figure 2(B), the second detection unit 23 receives light reflected by the first reflection mirror 26 or the second reflection mirror 27 of the incident light adjustment unit 25, so the second detection unit 23 can detect infrared light contained in the second incident light. This second detection unit 23 is, for example, a general infrared camera or infrared sensor, but is not particularly limited as long as it can detect the amount of infrared light contained in the second incident light. Furthermore, the second detection unit 23 may be equipped with a lens that focuses the light incident from the incident light adjustment unit 25, or if the second detection unit 23 is not equipped with a lens that focuses the light incident from the incident light adjustment unit 25, a lens that focuses the light incident from the incident light adjustment unit 25 may be separately provided between the incident light adjustment unit 25 and the second detection unit 23.

[0026] Furthermore, as shown in Figure 2(B), the second incident unit 22, the incident light adjustment unit 25, and the second detection unit 23 are arranged in a roughly L-shape. In other words, the second incident unit 22, the incident light adjustment unit 25, and the second detection unit 23 are arranged such that the optical axis 22s of the second incident light incident from the second incident unit 22 and the light receiving axis 23s of the second detection unit 23 are perpendicular at the position of the incident light adjustment unit 25 (specifically, the reflective surface 26a of the first reflective mirror 26 and the reflective surface 27a of the second reflective mirror 27 when they are positioned at the reflection position). Furthermore, the second incident unit 22, the incident light adjustment unit 25, and the second detection unit 23 do not necessarily have to be in a roughly L-shape (i.e., the optical axis 22s of the second incident light and the light-receiving axis 23s of the second detection unit 23 are perpendicular to each other), as long as the light reflected by the first reflection mirror 26 or the second reflection mirror 27 of the incident light adjustment unit 25 is reflected so that the optical axis of the light reflected coincides with the light-receiving axis 23s of the second detection unit 23.

[0027] Furthermore, the second infrared detection unit 20 is configured to detect infrared radiation from the same object A (see Figure 5) as the first infrared detection unit 11. Specifically, if the first incident part 12 of the first infrared detection unit 11 and the second incident part 22 of the second infrared detection unit 20 are both condensing lenses, they are positioned so that their focal point F is at the same location. Moreover, the optical path length L1 from the focal point F to the first detection part 13 of the first infrared detection unit 11 and the optical path length L2 from the focal point F to the second detection part 13 of the second infrared detection unit 21 are configured to be the same length.

[0028] Therefore, as shown in Figure 5(B), when external light, including infrared radiation emitted by the object under measurement A and infrared radiation passing through the position of the object under measurement, is incident from the second incident unit 22, if the first reflective mirror 26 is positioned at the reflection position, all wavelengths of light (or infrared radiation of all wavelengths) contained in the second incident light can be incident on the second detection unit 23. On the other hand, if the second reflective mirror 27 is positioned at the reflection position, only the second target infrared radiation can be incident on the second detection unit 23.

[0029] The first infrared detection unit 11 and the second infrared detection unit 20 may be configured to detect infrared radiation from the focal point F, that is, from a single point in space, as described above, or they may be configured to detect infrared radiation from a range having a certain extent in space, that is, from a region having a predetermined area or volume. By detecting infrared radiation from a region having a predetermined area or volume, it is possible to detect the two-dimensional or three-dimensional extent of the object A being measured (see Figure 11(B), etc.).

[0030] <Judgment part 30> As shown in Figures 1 and 2, the determination unit 30 is electrically connected to the second detection unit 13 of the first infrared detection unit 11 and the second detection unit 23 of the second infrared detection unit 20 of the detection unit 10. The determination unit 30 estimates the signals from the second detection unit 13 and the second detection unit 23, that is, the amount of infrared light detected by the second detection unit 13 and the second detection unit 23. Specifically, the determination unit 30 has the function of estimating the amount of first target infrared light based on the signal from the second detection unit 13 of the first infrared detection unit 11 of the detection unit 10. Furthermore, when the first reflective mirror 26 is positioned at the reflection position, the determination unit 30 has the function of estimating the amount of incident infrared light, that is, the sum of the amounts of infrared light of all wavelengths, based on the signal from the second detection unit 23 of the second infrared detection unit 20 of the detection unit 10. Furthermore, when the second reflection mirror 27 is positioned at the reflection location, the determination unit 30 has the function of estimating the amount of second target infrared light based on the signal from the second detection unit 23 of the second infrared detection unit 20 of the detection unit 10.

[0031] The method by which the determination unit 30 recognizes whether the first reflective mirror 26 or the second reflective mirror 27 is positioned at the reflection point is not particularly limited. For example, it can be determined by detecting the amount of movement of the moving member 29 or the position of the reference part using sensors or the like.

[0032] <Recognition section 40> As shown in Figure 1(B), the recognition unit 40 is electrically connected to the determination unit 30. The recognition unit 40 has the function of determining the object to be detected based on the amount of infrared light estimated by the determination unit 30. For example, if the amount of first target infrared light estimated by the determination unit 30 is above a certain level, it has the function of determining that a predetermined substance (first substance) is present in the object to be measured. Furthermore, if the amount of second target infrared light estimated by the determination unit 30 is above a certain level, it has the function of determining that another substance (second substance) is present in the object to be measured.

[0033] Furthermore, by using the light intensity of the first target infrared and the light intensity of the second target infrared estimated by the determination unit 30, the recognition unit 40 can determine the wavelength dependence of the target infrared light intensity by comparing the light intensity of the first target infrared and the light intensity of the second target infrared.

[0034] Furthermore, by utilizing the total amount of incident infrared light, it becomes easier to obtain light intensity that is free from the influence of ambient light, such as sunlight. In other words, by utilizing the amount of first target infrared light, the amount of second target infrared light, and the total amount of infrared light supplied from the judgment unit 30, the recognition unit 40 can more easily obtain the amount of first target infrared light and the amount of second target infrared light that are free from the influence of ambient light.

[0035] For example, as shown in Figures 11(A), 12(A), and 13(A), the second detection unit 23 can detect infrared radiation from ambient light, including sunlight, from the lower limit wavelength IR1 to the upper limit wavelength IR2. Also, as shown in Figures 11(A), 12(A), and 13(A), the lower limit of the wavelength range transmitted by the bandpass filter 14 is A1, and the upper limit is A2. Furthermore, as shown in Figure 11(A), the lower limit of the wavelength range reflected by the second reflection mirror 27 is B1, and the upper limit is B2.

[0036] Let's assume that the infrared spectrum detected by the first detection unit 13 at a certain timing T1 is T1, and the infrared spectrum detected by the first detection unit 13 at another timing T2 is T2. Then, if D1 = D2, the difference in light intensity when comparing the light intensity of wavelength X (or the average value of the infrared light intensity transmitted by the bandpass filter 14 (for example, the value obtained by dividing the total light intensity transmitted by the bandpass filter 14 by the wavelength range of the bandpass filter 14), i.e., the light intensity of the first target infrared) at timing T1 and timing T2 is D1, but if D2 is the difference in light intensity when comparing the light intensity of other wavelengths Y (or the average value of the infrared light intensity from the lower limit wavelength IR1 to the upper limit wavelength IR2 (for example, the value obtained by dividing the total light intensity detected by the second detection unit 23 by the detection range of the second detection unit 23)) at timing T1 and timing T2, then if D1 = D2, it can be determined that the change in the light intensity of wavelength X is due to fluctuations in ambient light and not a change in the object being measured. On the other hand, if D1 ≠ D2, the change in the amount of light at wavelength X can be judged to be due to a change in the state of the object being measured in addition to fluctuations in ambient light. Then, by correcting the amount of light at wavelength X (the amount of first target infrared light) using D2, the actual fluctuation of the amount of light at wavelength X (the amount of first target infrared light) can be estimated. Note that if wavelength Y is the amount of second target infrared light reflected by the second reflection mirror 27 (see Figure 11(A)), and it is clear that there is no substance that can be detected by the second target infrared light at the measurement position, then, similarly to the above, the influence of the disturbance can be estimated by using the change in the amount of light at wavelength Y (or the average value of the amount of infrared light reflected by the second reflection mirror 27 (for example, the value obtained by dividing the total amount of light reflected by the second reflection mirror 27 by the wavelength range of the second reflection mirror 27), i.e., the amount of second target infrared light) to estimate the effect of the disturbance and estimate the actual fluctuation of the amount of light at a given wavelength X (the amount of first target infrared light).

[0037] Furthermore, as shown in Figure 12(B), when a certain area TDI is designated as the inspection area, even if reflected ambient light from an object surface N that is not the object being measured is incident, it can be determined that it is not the object being measured. In other words, if the fluctuation in the amount of light of wavelength X obtained by reflection from the object surface N always matches the fluctuation in the amount of light of wavelength Y, it can be determined that the region is reflecting ambient light and is not due to the object being measured.

[0038] As described above, the detection device 1 of this embodiment has a detection unit 10 that includes a first infrared detection unit 11 and a second infrared detection unit 20. The first infrared detection unit 11 and the second infrared detection unit 20 can grasp the light intensity of different target infrared rays (first target infrared ray and second target infrared ray) at the same position (position of focal point F in Figure 5), so it is possible to simultaneously detect two targets present in the object being measured (see Figure 11). Furthermore, by using the light intensity of the first target infrared ray and the light intensity of the second target infrared ray, it becomes possible to determine the wavelength dependence of the light intensity of the target infrared ray.

[0039] Furthermore, by positioning the first reflection mirror 26 of the incident light adjustment unit 25 of the second infrared detection unit 20 at the reflection position, it is possible to obtain the light intensity of all incident infrared light, making it easier to obtain the light intensity of the first target infrared and the second target infrared, which are free from the effects of ambient light. This improves the detection accuracy of the object to be detected present in the object A being measured based on the first target infrared and the second target infrared.

[0040] <Regarding spatial detection> In the example described above, we explained the case where the wavelengths of the first target infrared light detected by the first infrared detection unit 11 and the second target infrared light detected by the second infrared detection unit 20 are different. However, the wavelengths of the first target infrared light and the second target infrared light may be the same. In that case, if the system is configured to detect the first target infrared light and the second target infrared light within a certain range (region), it may be possible to detect or estimate the three-dimensional state of the object being measured within that region. Furthermore, if the time variation of the three-dimensional state of the object being measured can be obtained, it may be possible to understand the movement of the object being measured in the optical axis direction (i.e., the direction of the optical axis 12s of the first incident light and the optical axis 22s of the second incident light), where detecting the movement of the object being measured is difficult.

[0041] <About Bandpass Filter 14> The bandpass filter 14 may be installed with its surface tilted relative to the light-receiving axis 13s of the first detection unit 13. This suppresses the influence of infrared radiation caused by the heat of the first detection unit 13. In other words, the first detection unit 13 generates heat during its operation and therefore emits infrared radiation due to that heat. For example, if the surface of the bandpass filter 14 and the light-receiving axis 13s of the first detection unit 13 are arranged perpendicular to each other, infrared radiation caused by the heat of the first detection unit 13 may be reflected by the surface of the bandpass filter 14 and incident on the first detection unit 13. If this infrared radiation includes infrared radiation of the wavelength of the first target infrared radiation, the amount of light of the first target infrared radiation estimated by the judgment unit 30 will include the influence of the first target infrared radiation caused by the heat of the first detection unit 13, making it impossible to properly determine the presence of the object to be detected on the object being measured. However, by installing the bandpass filter 14 with its surface tilted relative to the light-receiving axis 13s of the first detection unit 13, the incidence of infrared radiation caused by the heat of the first detection unit 13 on the first detection unit 13 can be suppressed. This suppresses the inclusion of influences other than those caused by the object to be detected in the measurement area in the first target infrared light intensity estimated by the judgment unit 30, thereby enabling an appropriate determination of the presence of the object to be detected. Moreover, since the first detection unit 13 can use inexpensive infrared cameras, such as those without a cooling function or with a low cooling function, the detection device 1 of this embodiment can also be manufactured at a low cost.

[0042] <When a laser light source 35 is provided> To improve the detection accuracy of substances present in a target object from infrared radiation obtained from the target object, it is desirable to increase the amount of infrared light detected. One way to increase the amount of infrared light detected is to irradiate the target object with infrared light from a light source. In the detection device 1 of this embodiment, infrared light can be irradiated from a light source to the target object in the following manner.

[0043] As shown in Figure 6, a laser light source 35 that emits infrared laser light or visible laser light (hereinafter simply referred to as "infrared laser light, etc.") is provided with an incident light adjustment unit 25 sandwiched between the second infrared detection unit 20 and the second incident unit 22. Specifically, the laser light source 35 is provided so that the optical axis 35s of the infrared laser light, etc. emitted from the laser light source 35 is coaxial with the optical axis 22s of the second incident unit 22, that is, the optical axis of the second incident light.

[0044] Furthermore, the movable member 29 of the incident light adjustment unit 25 is provided with a transmissive window 28 that transmits infrared laser light or the like emitted from the laser light source 35. The transmissive window 28 is capable of transmitting infrared laser light or the like, and for example, a material such as glass that transmits infrared laser light or the like may be used as the transmissive window 28, or a through hole provided in the movable member 29 may be used as the transmissive window 28. The transmissive window 28 is provided on the movable member 29 so that it moves between a transmission position and a retracted position when the movable member 29 moves by the movement mechanism. Specifically, when the movable member 29 moves and the first reflective mirror 26 or the second reflective mirror 27 is positioned in the reflection position, the transmissive window 28 is positioned in the retracted position, and when both the first reflective mirror 26 and the second reflective mirror 27 are positioned in the retracted position, the transmissive window 28 is positioned in the transmission position. The movement mechanism has the function of a position adjustment mechanism as described in the claims.

[0045] The transmission position is the position where the transmission window 28 is positioned on the optical axis 35s of the infrared laser light emitted from the laser light source 35 (in other words, on the optical axis of the second incident light incident from the second incident section 22). When the transmission window 28 is positioned at this position, the infrared laser light emitted from the laser light source 35 passes through the transmission window 28 and the second incident section 22 and irradiates the object to be measured. Note that the transmission position of the transmission window 28 may be the same as the reflection positions of the first reflection mirror 26 and the second reflection mirror 27. The retracted position is the position where the transmission window 28 is retracted from the optical axis 35s of the infrared laser light emitted from the laser light source 35 (in other words, from the optical axis of the second incident light incident from the second incident section 22). In other words, the retracted position is the position where, when the transmission window 28 is positioned, the infrared laser light emitted from the laser light source 35 does not enter the second incident section 22.

[0046] For example, as shown in Figure 7(B), when the moving member 29 moves in a straight line, the transparent window 28 is positioned to be aligned with the first reflective mirror 26 and the second reflective mirror 27 along the direction of movement of the moving member 29 (left and right direction in Figure 7(B)). Furthermore, as shown in Figure 7(C), when the movable member 29 rotates, the transparent window 28 is positioned to align with the first reflective mirror 26 and the second reflective mirror 27 along the rotational direction (i.e., circumferential direction) of the movable member 29.

[0047] As described above, by providing a laser light source 35 and a transmission window 28, and by positioning the transmission window 28 at the transmission point and irradiating the object to be measured with infrared laser light from the laser light source 35, the amount of first target infrared light detected by the first detection unit 13 of the first infrared detection unit 11 can be increased. This improves the accuracy of detecting substances present in the object to be measured from the first target infrared light detected by the first detection unit 13.

[0048] Furthermore, if the substance present in the object being measured emits absorbed infrared radiation, by placing the transmission window 28 at the transmission position, irradiating the object with infrared laser light from the laser light source 35, and then placing the second reflection mirror 27 at the reflection position, it becomes possible to increase the amount of second target infrared light detected by the second detection unit 23 of the second infrared detection unit 20. This improves the accuracy of detecting the substance present in the object being measured from the second target infrared light detected by the second detection unit 23. For example, as shown in Figure 13(A), if there are increases and decreases (peaks and valleys) in the amount of infrared light depending on the wavelength in a predetermined wavelength range, irradiating with laser light may increase the range of increases and decreases, potentially improving the detection accuracy of the object being measured. In this case, it is necessary to obtain spectral characteristics by spectrally analyzing the measured infrared light.

[0049] Furthermore, if the area illuminated by the laser light emitted from the laser light source 35 has a certain degree of spread, it becomes possible to grasp a wide range of objects to be measured that exist over a certain area. For example, as shown in Figure 13(B), laser light is irradiated into a predetermined area (LA in Figure 13(B)) of the region where the object to be measured is assumed to exist. Then, the presence of the object to be measured can be confirmed even in areas with low concentration. In other words, the object to be measured can be detected in a wider area AT4 than in the area AT3 where the object to be measured is detected when the laser light is not irradiated, so the presence of the object to be measured can be confirmed over a wider area. In short, by irradiating with laser light, the detection accuracy of the object to be measured can be improved compared to when the laser light is not irradiated.

[0050] The laser light source 35 may be capable of emitting infrared light of a single wavelength, or it may be capable of emitting infrared light of multiple wavelengths. Furthermore, the laser light source 35 may be equipped with multiple laser light sources of different wavelengths capable of emitting infrared light of a single wavelength. This allows for the irradiation of laser light suitable for the object to be measured, and by irradiating with laser light of multiple wavelengths simultaneously, the detection accuracy of multiple objects to be measured can be improved.

[0051] <When a visible light imaging unit 60 is provided> The detection device 1 of this embodiment may also include a visible light imaging unit 60 that captures visible light (see Figure 7(A)). If a visible light imaging unit 60 is included, the conditions of the area where the object to be measured is located can be captured. By superimposing the image captured by the visible light imaging unit 60 with the infrared measurement results to form an image, the conditions of the object to be measured in the area where the object A is located can be visually grasped (see Figures 11(B), 12(B), and 13(B)). In particular, by superimposing the two-dimensional infrared measurement results and checking their changes over time, the movement of the object to be measured, that is, changes in the direction and density of the object as it moves, can be grasped.

[0052] Furthermore, if a visible light imaging unit 60 is provided, the location where the visible light laser is irradiated can be determined by irradiating the laser light source 35 with visible light laser light. The visible light laser light emitted from the laser light source 35 passes through the second incident unit 22 and is irradiated onto the object to be measured, so the position where the visible light laser light is irradiated indicates the position where infrared radiation detected by the second detection unit 23 is emitted through the second incident unit 22, that is, the position of the substance from which the target infrared radiation is to be detected. Therefore, if a visible light imaging unit 60 that captures visible light is provided, it becomes easy to determine the position from which the target infrared radiation is to be detected, that is, the position where the substance is located.

[0053] <Regarding the incident light adjustment unit 25> In the example described above, the incident light adjustment unit 25 was configured to reflect the second incident light or the second target infrared light with the first reflecting mirror 26 or the second reflecting mirror 27 and direct it into the second detection unit 23. The incident light adjustment unit 25 may also be configured to direct the second incident light or the second target infrared light into the second detection unit 23 without reflection.

[0054] As shown in Figures 8 and 9, the second infrared detection unit 20 is installed such that the optical axis 22s of the second incident light incident from the second incident unit 22 and the optical axis 23s of the second detection unit 23 are coaxial. In other words, a window member 26b that transmits all wavelengths (or infrared rays of all wavelengths) is installed on the movable member 29b in place of the first reflective mirror 26, and a bandpass filter 27b that transmits only the second target infrared rays is installed on the movable member 29b in place of the second reflective mirror 27. In this case, the movable member 29b holds the window member 26b and the bandpass filter 27b so that the optical axis 26s of the window member 26b and the optical axis 27s of the bandpass filter 27b are parallel to the optical axis 23s of the second detection unit 23 (in other words, the optical axis 22s of the second incident light). Then, by moving the movable member 29b so that the window member 26b is positioned between the second incident unit 22 and the second detection unit 23, the second detection unit 23 can detect all infrared rays of the second incident light. On the other hand, by moving the movable member 29b so that the bandpass filter 27b is positioned between the second incident unit 22 and the second detection unit 23, the second detection unit 23 can detect the amount of second target infrared light in a predetermined wavelength range.

[0055] Furthermore, the aforementioned window member 26b corresponds to the total light supply unit as defined in the claims, and the aforementioned bandpass filter 27b corresponds to the second-purpose infrared supply unit as defined in the claims. In addition, the position where the window member 26b and the bandpass filter 27b are positioned between the second incident unit 22 and the second detection unit 23 becomes the supply position as defined in the claims, and the position where one of the window member 26b and the bandpass filter 27b is positioned while the other is positioned becomes the retracted position as defined in the claims.

[0056] <When a laser light source 35 is provided> As shown in Figures 8 and 9, even if the second infrared detection unit 20 is configured such that the second incident unit 22, the incident light adjustment unit 25, and the second detection unit 23 are aligned in a straight line, the same effect as described above can be obtained by providing a laser light source 35. In this case, the laser light source 35 cannot be placed in the position shown in Figure 6, so as shown in Figure 10, the laser light source 35 can be placed to the side of the incident light adjustment unit 25 (either above or below). That is, a reflective mirror 28b that reflects laser light is provided on the movable member 29 of the incident light adjustment unit 25, and the laser light source 35 is positioned so that the optical axis 35s of the laser light reflected by the reflective mirror 28b is coaxial with the optical axis 22s of the second incident light. Then, even with the second infrared detection unit 20 configured as shown in Figures 8 and 9, laser light can be irradiated from the laser light source 35 onto the object to be measured.

[0057] The laser light source 35 may be detachably mounted on the case 2. If the laser light source 35 is not needed, it can be removed, making the detection device 1 of this embodiment more compact. Furthermore, since the installed laser light source 35 can be changed, it becomes possible to use an appropriate laser light source 35 depending on the object being measured.

[0058] <Method for detecting targets> In the detection device 1 of this embodiment, the method for determining the object to be detected based on the detected infrared radiation of a predetermined wavelength is not particularly limited. Various known methods can be employed.

[0059] Furthermore, if the infrared radiation to be detected is set to a wavelength range with a certain width, it is also possible to employ a method that measures and analyzes the infrared radiation contained in that wavelength range, for example, using Fourier spectroscopy, to identify and distinguish the object being measured or the substances contained in the object being measured.

[0060] When using Fourier spectroscopy, for example, an interference light formation mechanism is provided between the bandpass filter 14 of the detection unit 10 and the first detection unit 13, or between the incident light adjustment unit 25 and the second detection unit 23. Furthermore, the judgment unit 30 is provided with a function to identify and specify a substance by analyzing the optical path length difference of the interference light generated by the interference light formation mechanism and the signals related to the light intensity of the interference light detected by the first detection unit 13 and the second detection unit 23. In other words, an interferogram is formed based on the signals supplied from the first detection unit 13 and the second detection unit 23 regarding the light intensity of the interference light, and spectral characteristics (spectral characteristics shown in Figure 11(A), etc.) are obtained by performing a Fourier transform on this interferogram. Based on these spectral characteristics, the judgment unit 30 is provided with a function to identify and specify the object to be measured and the substances contained in the object to be measured. Thus, the object to be measured and the substances contained in the object to be measured can be identified and specified based on the infrared light detected by the first detection unit 13 and the second detection unit 23.

[0061] Furthermore, when using Fourier spectroscopy, the interference light generation mechanism provided in the detection unit 10 is not particularly limited, and various interference light generation mechanisms can be employed. It is also possible to replace the bandpass filter 14 and incident light adjustment unit 25 of the detection unit 10 with an interference light generation mechanism. In this case, spectroscopic analysis can be performed using all the light (all infrared) of the first and second incident light, thereby improving the accuracy of the spectroscopic analysis. In this case, if the bandpass filter 14 and incident light adjustment unit 25 are detachable and the interference light generation mechanism is freely interchangeable, measurements can be performed according to the purpose. In other words, by installing the bandpass filter 14 and incident light adjustment unit 25, the object to be measured and the substances contained in the object to be measured can be identified from the amount of infrared light in a predetermined wavelength range in the first and second incident light, and by installing the interference light generation mechanism, the object to be measured and the substances contained in the object to be measured can be identified by spectroscopic analysis of the first and second incident light. [Industrial applicability]

[0062] The detection device of the present invention is suitable for detecting gases leaking from piping in plants and other facilities, as well as gases leaking from piping in essential infrastructure during disasters or normal daily life. [Explanation of Symbols]

[0063] 1. Detection device 10 Detection unit 11 First infrared detection unit 12 First entrance part 13 First detection unit 14 Bandpass Filter 20 Second infrared detection unit 22 Second entrance part 23 Second detection unit 25 Incident light adjustment section 26 First Reflecting Mirror 27 Second Reflecting Mirror 28 Translucent window 29 Movable member 27b Transparent window 28b Bandpass filter 29b Movable member 30 Judgment Department 35 Laser light source

Claims

1. A detection device for detecting target infrared radiation of a predetermined wavelength, A detection unit that detects infrared rays, The system includes a determination unit that estimates the amount of target infrared light based on the infrared light detected by the detection unit, The detection unit, It is equipped with a first infrared detection unit and a second infrared detection unit. The first infrared detection unit is A first incident section into which light including infrared rays is incident, A first detection unit that detects infrared radiation contained in the first incident light incident from the first incident unit, It comprises a bandpass filter that transmits a first target infrared light, which is positioned between the first detection unit and the first incident unit. The second infrared detection unit is A second incident section into which light including infrared rays is incident, A second detection unit detects infrared radiation contained in the second incident light incident from the second incident unit, It comprises an incident light adjustment unit positioned between the second detection unit and the second incident unit, The incident light adjustment unit is, A total light supply unit that supplies all of the second incident light to the second detection unit, A second target infrared supply unit supplies the second target infrared light contained in the second incident light to the second detection unit, The system includes a moving mechanism for moving the total light supply unit and the second target infrared supply unit between a supply position located on the optical axis of the second incident light and a retracted position moved away from the optical axis of the second incident light. A detection device characterized by the following features.

2. The second detection unit is, The light-receiving axis of the second detection unit and the optical axis of the second incident light are arranged to intersect. The incident light adjustment unit is, The aforementioned total light supply unit is a first reflective mirror that reflects the second incident light, The aforementioned second target infrared supply unit is a second reflecting mirror that reflects the second target infrared light contained in the second incident light. The detection device according to claim 1, characterized in that it is a detection device.

3. It is equipped with a visible light imaging unit that captures visible light. The detection device according to claim 2, characterized in that it is as described above.

4. The system is equipped with a laser light source that emits laser light coaxial with the optical axis of the second incident light, The incident light adjustment unit is, It is equipped with a transmission window that transmits the laser light emitted from the laser light source, The aforementioned moving mechanism is The system has a function to move the transmission window between a transmission position located on the optical axis of the second incident light and a retracted position set back from the optical axis of the second incident light. The detection device according to claim 1, characterized in that it is a detection device.

5. It is equipped with a visible light imaging unit that captures visible light, The laser light source emits laser light, and with the transmission window positioned at the transmission position, the visible light imaging unit captures the position irradiated by the laser light. The detection device according to claim 4, characterized in that it is a detection device.

6. The supply position and the transmission position are the same position. The aforementioned moving mechanism is The aforementioned total light supply unit, the aforementioned second purpose infrared supply unit, and the movable member provided with the transmissive window, The system includes a position adjustment mechanism that moves the movable member to move the total light supply unit and the second target infrared supply unit between the supply position and the retracted position, and moves the transmissive window between the transmission position and the retracted position. The detection device according to claim 4 or 5, characterized in that it is a detection device according to claim 4 or 5.

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