JPH11223630A - Chemical or biological species sensing device with opticl fiber utilized, and remote monitoring system using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To be safe, simple in configuration and easy to manufacture,
Provided is a highly reliable, inexpensive, and miniaturizable species detection device. A reflection-type species detection device for detecting the presence or concentration of a chemical or biological species includes a light source (2) and a reflection film (6) at one end, and receives light emitted from the light source (2). Between the light source 2 and the sensor 4, transmitting the light reflected by the reflective film 6 in the opposite direction, causing a measurable change in the light transmission characteristics in the presence of a chemical or biological species. And a light transmitting / extracting unit 8 that transmits light from the light source 2 to be incident on the sensor 4 and outputs reflected light from the reflective film 6. The presence or the like of a seed is detected using a signal corresponding to the reflected light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a species detection device for detecting the presence and / or concentration of a chemical or biological species, and a remote monitoring system using the same.

[0002]

2. Description of the Related Art There have been many proposals for a detecting device using an optical fiber. For example, a fuel vapor detector shown in FIG. 8 has been proposed to optically detect fuel vapor. In this fuel vapor detector, a light beam sent from a light source 200 via one optical fiber 202 is incident on a polymer thin film 206 formed on a substrate 204. The light beam reflected by the polymer thin film 206 is sent to the photodetector 210 via the other optical fiber 208 and detected. Polymer thin film 20
6 reacts with, or adsorbs or absorbs, the fuel vapor passing through the passageway 212, and as a result of such interaction, the thickness and / or refractive index of the polymer thin film 206 changes. Since the fuel vapor is optically detected by utilizing the inherent characteristics of the polymer thin film 206, it is possible to detect a fuel leak at an early stage, and to use the optical fibers 202 and 208 (electrically. Has the advantage of being inherently secure.

The fuel vapor detector shown in FIG. 8 is an interference-enhanced reflection method (Interference Enhanced R).
(hereinafter, referred to as IER method), and the light reflected on the surface of the polymer thin film 206 has a phase relationship with the light reflected on the surface of the substrate 204 supporting the polymer thin film 206, Interfere with each other. Therefore,
When the thickness and / or the refractive index of the polymer thin film 206 changes, the reflectance or the intensity of the reflected light of the polymer thin film 206 changes. It becomes possible to detect.

Further, US Pat. No. 4,846,548 discloses a chemical species detecting device using an optical fiber. As shown in FIGS. 9A and 9B, this type of detection device includes a light source 300 such as an LED, a chemical sensor 302 using an optical fiber, and a light emitted from the chemical sensor 302. A photodetector 304 such as a photodiode that converts the electric signal into an electric signal. 9A, light in the main axis direction of the chemical sensor 302 is emitted, and in FIG.
The light deviating from the principal axes of No. 2 is detected by the photodetector 304, respectively.

As shown in FIGS. 9A and 9B and FIG. 10A, a chemical sensor 302 surrounds a core 306 made of a material used in a normal optical fiber and surrounds the core. And a clad 308. Light emitted from the light source 300 is totally reflected at the interface between the core 306 and the clad 308, propagates in the core 306, and enters the light detector 304. The cladding 308 is made from materials that are sensitive to chemical or biological species, and when these species are present, the cladding 308 changes the light transmission properties of the chemical sensor 302. In addition, as shown in FIG.
The outer surface of the cladding 308 is covered with a cladding 310 made of a porous polymer, and the species to be detected is the outer cladding 31.
It may be possible to contact the inner cladding 308 through zero.

[0006] However, the fuel vapor detector shown in FIG. 8 has an optical fiber 202 between the light source 200 and the optical fiber 202.
It is necessary to dispose a collimator and a connector between the optical fiber 208 and the photodetector 210, respectively, between the optical fiber 208 and the photodetector 210, which is not only complicated in configuration but also expensive. Having. Also, the species detection device shown in FIGS. 9 and 10 has a photodetector 304 that is electrically operated at one end of the chemical sensor 302. Anxiety about using it in a sexual atmosphere cannot be wiped out.

A further consideration is that there is a need for a system that can remotely monitor the presence or concentration of a chemical or biological species.

[0008]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above problems, and a general object of the present invention is to provide an inexpensive and simple chemical or biological system using an optical fiber. It is to provide a species detection device for detecting the presence and / or concentration of a species. More specifically, the present invention
It is an object of the present invention to provide a species detection device that is inherently safe, has a simple configuration, is easy to manufacture, has high reliability, is inexpensive, and can be downsized. Still another object of the present invention is to provide a remote monitoring system that can remotely monitor the presence and / or concentration of a species using such a species detection device.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a reflective species detection device for detecting at least one of the presence and concentration of a chemical or biological species, and Provided is a transmission-type species detection device.

As shown in FIG. 1A, a reflection-type seed detecting device according to the present invention has a light source 2 and a light having a predetermined wavelength emitted from the light source 2 received at one end and transmitted. A sensor 4 having a reflecting means 6 at an end for transmitting light reflected by said reflecting means in a reverse direction, wherein said sensor 4 produces a measurable change in light transmission characteristics in the presence of a chemical or biological species. 4, disposed between the light source 2 and the one end of the sensor 4, transmitting light from the light source 2 to be incident on the one end of the sensor 4, and being reflected by the reflection means 6 and And a light transmitting / extracting unit 8 that outputs reflected light transmitted through the sensor 4 in the reverse direction.

[0011] In one embodiment of the present invention,
The reflection type species detection device includes a reference light detection unit 22 that generates a reference signal corresponding to the light emitted from the light source 2, the reflected light from the light transmission / extraction unit 8, and the reference light detection unit 22. And a reflected light processing unit 10 that processes the reference light from the optical disc and generates a signal corresponding to the reflected light.

On the other hand, as shown in FIG. 1B, a transmission type seed detecting apparatus according to the present invention comprises a light source 2 and the light source 2.
A sensor 4 receiving at one end light of a predetermined wavelength emitted from the sensor 4 and outputting from the other end, wherein the sensor 4 produces a measurable change in light transmission characteristics in the presence of a chemical or biological species; Is provided.

In another embodiment of the present invention, the transmission type seed detecting device includes a reference light detecting section 22 for generating a reference signal corresponding to the light emitted from the light source 2, and an output from the sensor 4. A transmitted light processing unit 12 that processes the transmitted light and the reference light to generate a signal corresponding to the transmitted light
And further comprising:

In these reflection-type and transmission-type species detecting devices, the sensor 4 is an optical fiber element having a core 14 for transmitting light of a predetermined wavelength from the light source 2 and a cladding 16 surrounding the core. Thus, at least a portion of the cladding 16 is made of a material that changes the optical properties of the portion in response to a chemical or biological species to be detected and changes the light transmission properties of the fiber optic element. For example,
The cladding 16 changes the refractive index in response to the chemical or biological species to be detected.

The cladding 16

Embedded image Is preferably a homopolymer or a copolymer having a repeating unit represented by the following formula: Here, X is -H,-
_{F, -Cl, -Br, -CH 3} , -CF 3, -CN , or -
CH ₂ —CH ₃ , R ¹ represents —R ² or —Z—R ² , and Z is —O—, —S—, —NH—, —NR ² ′-,
-(C = Y)-,-(C = Y) -Y-, -Y- (C =
_{Y) -, - (SO 2} ) -, - Y '- (SO 2) -, - (S
_{O 2) -Y '-, -} Y' - (SO 2) -Y '-, - NH-
(C = O)-,-(C = O) -NH-,-(C = O)-
NR ² '-, -Y'-(C = Y) -Y'- or -O-
(C = O) - (CH 2) n - (C = O) represents -O-, Y
Independently represents O or S; Y 'independently represents O or NH
And n represents an integer of 0 to 20, and R ² or R ² ′ is
Independently represents hydrogen, a straight chain alkyl group, a branched chain alkyl group, a cycloalkyl group, an unsaturated hydrocarbon group, an aryl group, a saturated or unsaturated heterocycle, or a derivative thereof. However, R ¹ is not hydrogen, a linear alkyl group, or a branched alkyl group.

Preferably, X in the repeating unit (I) represents H or CH ₃ , R ¹ represents a substituted or unsubstituted aryl group or —ZR ² , and Z represents —O—, (C =
O) represents —O— or —O— (C ＝ O) —, and R ² represents a linear alkyl group, a branched alkyl group, a cycloalkyl group, an unsaturated hydrocarbon group, an aryl group, a saturated or unsaturated heterocyclic ring Or a derivative thereof.

The polymer used as the cladding 16 may be a polymer composed of only the single repeating unit (I), or may be composed of another repeating unit (I).
And the above-mentioned repeating unit (I)
May be used. The arrangement of the repeating units in the copolymer may be any. For example, a random copolymer, an alternating copolymer, a block copolymer, or a kraft copolymer can be used. In particular, the cladding 16 is preferably prepared from polymethacrylates and polyacrylates. The side chain group of the ester is preferably a linear or branched alkyl group or a cycloalkyl group, and has 4 to 22 carbon atoms.

Particularly preferred polyacryls for the cladding 16 are listed below: poly (dodecyl methacrylate) poly (isododecyl methacrylate) poly (methacrylic acid-ethylhexyl) poly (2-ethylhexyl methacrylate-co-methyl methacrylate) poly (2-ethylhexyl methacrylate-co-styrene) poly (methyl methacrylate-co-2-ethylhexyl acrylate) poly (methyl methacrylate-co-2-ethylhexyl methacrylate) poly (isobutyl methacrylate-co-glycidyl methacrylate) poly (Cyclohexyl methacrylate) poly (octadecyl methacrylate) poly (octadecyl methacrylate-co-styrene) poly (vinyl propionate) poly (dodecyl methacrylate-co-styrene) Poly (butyl methacrylate-co-glycidyl methacrylate) Poly (butyl methacrylate) Poly (butyl methacrylate-co-methyl methacrylate) Poly (butyl methacrylate-co-glycidyl methacrylate) Poly (2-ethylhexyl methacrylate) co-glycidyl methacrylate poly (cyclohexyl methacrylate-co-glycidyl methacrylate) poly (cyclohexyl methacrylate-co-methyl methacrylate) poly (benzyl methacrylate-co-methacrylic acid 2-)
Ethylhexyl Poly (2-ethylhexyl methacrylate-co-diacetone acrylamide) Poly (2-ethylhexyl methacrylate-co-benzyl-methacrylate-co-glycidyl methacrylate) Poly (2-ethylhexyl methacrylate-co-methyl methacrylate) co-glycidyl methacrylate poly (vinyl cinnamate) poly (vinyl cinnamate-co-dodecyl methacrylate) poly (tetrahydrofurfuryl methacrylate) poly (hexadecyl methacrylate) poly (2-ethylbutyl methacrylate) poly (methacrylic acid) 2-hydroxyethyl) poly (cyclohexyl methacrylate-co-isobutyl methacrylate) poly (cyclohexyl methacrylate-co-2-ethylhexyl methacrylate) poly (butyl methacrylate-c) -2-ethylhexyl methacrylate) poly (butyl methacrylate-co-isobutyl methacrylate) poly (cyclohexyl methacrylate-co-butyl methacrylate) poly (cyclohexyl methacrylate-co-dodecyl methacrylate) poly (butyl methacrylate-co -Ethyl methacrylate) Poly (butyl methacrylate-co-octadecyl methacrylate) Poly (butyl methacrylate-co-styrene) Poly (4-methylstyrene) Poly (cyclohexyl methacrylate-co-benzyl methacrylate) Poly (methacrylic acid) Dodecyl-co-benzyl methacrylate poly (octadecyl methacrylate-co-benzyl methacrylate) poly (benzyl methacrylate-co-tetrahydrofurfuryl methacrylate) poly (methacrylic acid) Poly (benzyl methacrylate-co-methyl methacrylate) poly (dodecyl methacrylate-co-ethyl methacrylate) poly (2-ethylhexyl methacrylate-co-dodecyl methacrylate) poly (methacrylic acid) 2-ethylhexyl-co-octadecyl methacrylate) poly (2-ethylbutyl methacrylate-co-benzyl methacrylate) poly (tetrahydrofurfuryl methacrylate-co-glycidyl methacrylate) poly (styrene-co-octadecyl acrylate) poly ( Octadecyl methacrylate-co-glycidyl methacrylate poly (4-methoxysterene) poly (2-ethylbutyl methacrylate-co-glycidyl methacrylate) poly (styrene-co-methacrylic acid ester) Lahydrofurfuryl) poly (2-ethylhexyl methacrylate-co-propyl methacrylate) poly (octadecyl methacrylate-co-isopropyl methacrylate) poly (3-methyl-hydroxystyrene-co-4-hydroxystyrene) poly (styrene) -Co-2-ethylhexyl methacrylate-co-glycidyl methacrylate).

In the methacrylic ester polymer or copolymer, acrylic acid may be used instead of methacrylic acid. The above polymer can be crosslinked by itself, but can be crosslinked by introducing a compound having a reactive group for crosslinking into the polymer. As such a reactive group for crosslinking, for example, an amino group, a hydroxyl group, a carboxyl group,
Epoxy, carbonyl and urethane groups and their derivatives, and maleic, fumaric, sorbic, itaconic and cinnamic acids and their derivatives can be mentioned. Substances having a chemical structure capable of forming carbene or nitrene upon irradiation with visible light, ultraviolet light, or high-energy radiation can also be used as the crosslinking agent. Since the film formed from the crosslinked polymer is insoluble, the stability of the detector can be increased by crosslinking the polymer forming the cladding 16. The crosslinking method is not particularly limited, and a conventionally known crosslinking method, for example, a method by heating or a method by irradiation with light or radiation can be used.

Also,

Embedded image Is preferably a homopolymer or a copolymer having a repeating unit (II) represented by The polymer used as the polymer thin film is composed of a single repeating unit (I)
It may be a polymer consisting of only I) or a copolymer consisting of another repeating unit and the above repeating unit (II). The arrangement of the repeating units in the copolymer may be any. For example, a random copolymer, an alternating copolymer, a block copolymer or a graft copolymer can be used.

In the species detection device shown in FIGS. 1A and 1B, a light source such as a laser diode or a light emitting diode that emits visible light or infrared light is used alone or in combination with a collimator or the like as the light source 2. Can be. The collimator used here is preferably a commercially available connector with a collimator lens, a selfoc lens, or the like. In order to make the light from the light source 2 parallel, it is preferable to provide a collimator lens. As such a collimator lens, a glass spherical convex lens, a glass aspheric convex lens, a plastic spherical convex lens, a plastic aspheric convex lens, a quartz spherical convex lens, a quartz aspheric convex lens, a selfoc lens, a ball lens, and the like can be used.
Quartz aspheric convex lenses are preferred.

In the reflection type seed detecting device shown in FIG. 1A, a glass plate, a beam splitter, a polarizing beam splitter, a non-polarizing beam splitter, or a half mirror may be used as the light transmitting / extracting unit 8. And preferably a beam splitter. The light detection unit 10 can be formed of any one of a photodiode, a phototransistor, and a photomultiplier, but it is preferable to use a photodiode. Further, it is preferable that the reflection means 6 is a reflection film provided on one end of the optical fiber element. Examples of the reflection film include a metal mirror and a dielectric laminated film mirror.

The light source 2 and the light transmitting / extracting portion 8 can be directly connected via the optical fiber 18 or without any optical device. As the light source 2 in this case, a laser diode or a light emitting diode is suitable. Similarly, the light transmission / extraction unit 8 and the sensor 4 can be coupled via the optical fiber 20 or without any optical device. It is preferable that the light beam emitted from the light transmission / extraction unit 8 is introduced into one end of the optical fiber 20 via a collimator. The collimator used here is preferably a commercially available connector with a collimator lens, a selfoc lens, or the like.

The optical fibers 18 and 20 shown in FIGS. 1A and 1B are a single mode optical fiber, an optical fiber optical waveguide composed of a multimode optical fiber and a single mode fiber, or a multimode optical fiber. Preferably, it is an optical fiber optical waveguide made of fiber.
Since the light emitted from the optical fibers 18 and 20 has a considerable spread angle, it is preferable that the light is condensed by a lens and made incident on the light transmission / output unit 8 and the sensor 4. The lens for this purpose is preferably a glass spherical convex lens, a glass aspheric convex lens, a plastic spherical convex lens, a plastic aspheric convex lens, a quartz spherical convex lens, a quartz aspheric convex lens, a selfoc lens, a ball lens, or the like.

Actually, the light source unit 2 and the light transmitting / extracting unit 8
It is desirable that the reflected light detecting unit 10 and the reflected light detecting unit 10 be integrated as a light emitting / receiving unit, housed in one case, and installed in an explosion-proof safe area. In this case, an integrated light-emitting / light-receiving laser to which a hologram is added (Japanese Patent Laid-Open No. 6-525)
No. 88) is advantageous.

As shown in FIG. 1A, the reflection type species detecting device further includes a reference light detecting unit 22 for extracting a reference light from the light source 2 and outputting a reference value corresponding to the reference light. Is preferred. In this case, the reflected light detecting unit 10 compares the generated electric signal with the reference value by using a light-to-electric conversion unit that generates an electric signal corresponding to the reflected light from the sensor 4, and as a result of the comparison, Processing means to indicate the presence and / or concentration of the target or biological species.

Next, also in the species detecting device shown in FIG. 1B, optical fibers 24 and 26 are provided between the light source 2 and the sensor 4 and between the sensor 4 and the transmitted light detecting unit 12, respectively.
Can be combined by These optical fibers 2
Preferably, the optical fibers 4 and 26 are an optical fiber optical waveguide composed of a single mode optical fiber, a multimode optical fiber and a single mode fiber, or an optical fiber optical waveguide composed of a multimode optical fiber. Since the light emitted from the optical fibers 24 and 26 has a considerable divergence angle, it is preferable that the light is condensed by a lens before being incident on the sensor 4 and the transmitted light detection unit 12. Lenses for this purpose are glass spherical convex lenses, glass aspheric convex lenses,
Plastic spherical convex lenses, plastic aspheric convex lenses, quartz spherical convex lenses, quartz aspheric convex lenses, Selfoc lenses, ball lenses, and the like are preferable.

Further, as shown in FIG. 1B, the transmission type seed detecting device further includes a reference light detecting unit 22 for extracting a reference light from the light source 2 and outputting a reference value corresponding to the reference light. Preferably, it is provided. In this case, the transmitted light detector 12
Comprises a light-to-electric conversion means for generating an electric signal corresponding to the transmitted light from the sensor 4, comparing the generated electric signal with the reference value, and as a result of the comparison, the presence of a chemical or biological species. And / or processing means for notifying the concentration.

Further, the present invention provides a remote monitoring system using the above-described reflection-type and transmission-type species detection devices and eliminating the need to dispose an electrical device at a monitored location. In this remote monitoring system, the sensors 4 of these species detection devices are arranged at monitored locations, while in the reflection type species detection device, the light source 2, the light transmission / output unit 8, the reference light detection unit 22, and the reflection When the light processing unit 10 is a transmission-type species detection device, the light source 2, the reference light detection unit 22, and the transmitted light processing unit 12 are installed in an alarm control unit that is located at a predetermined distance from the monitored location. .

[0030] The alarm control unit, based on the electric signal output from the reflected light processing unit 10 or the transmitted light processing unit 12,
A judgment circuit for judging whether or not an abnormal state including a trouble of the sensor 4 and the presence of a chemical or biological species at a place where the sensor 4 is installed, and accumulating data indicating a judgment result by the judgment circuit; A memory for performing the determination, and when the determination result does not indicate the occurrence of an abnormal state, the data stored in the memory is reported to a distant point at predetermined time intervals, and the determination result indicates that an abnormal state has occurred. And a reporting means for immediately reporting to the distant point.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically with reference to some embodiments, but the present invention is not limited to these embodiments. In the following description, the same reference numeral or reference symbol indicates the same or similar component.

FIG. 2A is a diagram schematically showing the configuration of an embodiment of the species detection apparatus according to the present invention.
(A) corresponds to the reflection type seed detection device. In the species detection device, the light source 2 is, for example, a laser diode 30.
It is. The light emitted from the laser diode 30 is
Optical fiber 1 through collimator lens and condenser lens
8, the light emitted from the laser diode 30 to the opposite side is referred to as a first photodiode (reference channel photodiode) 34 as reference light.
Is incident on. The light incident on the optical fiber 18 passes through the beam splitter 32 as the light transmitting / extracting unit 8, is collected by the collimator 36, and
After propagating in the chemical sensor 4 via the connector 38
0 is introduced.

The chemical sensor 40 is an optical fiber type sensor comprising a light-transmitting core and a clad surrounding the core, as described in the aforementioned US Pat. No. 4,846,548. The clad is made of a material that changes optical characteristics such as a refractive index by reacting with a substance to be detected such as a hydrocarbon. The light introduced into the chemical sensor 40 is reflected by the reflection film 42 provided at the end.

A first photoelectric conversion element, for example, a photodiode (a reference channel photodiode)
The laser beam received at 34 is converted into a current signal, and is converted into a voltage signal by a first current-voltage conversion circuit 44. On the other hand, the light reflected by the reflection film 42 propagates along the same path as the original path, enters the beam splitter 32, is bent at a right angle, and serves as a detection signal as a second photoelectric conversion element, for example, a photodiode (signal channel). The light is received by a photodiode 46 and converted into a current signal, and further converted by a second current-voltage conversion circuit 48 into a voltage signal.

The first photoelectric conversion element 34 and the first current-voltage conversion circuit 44 constitute a circuit corresponding to the reference light detection section 22, and the second photoelectric conversion element 46 and the second current −
The voltage conversion circuit 48 forms a circuit corresponding to the reflected light detection unit 10.

Next, the operation of the seed detecting device shown in FIG. 2A will be described. Light emitted from the laser diode 30 passes through the beam splitter 32, passes through the collimator 36, the optical fiber 20, and the connector 38. And enters the chemical sensor 40, propagates through the chemical sensor 40, and is reflected by the reflection film 42. Thereafter, the reflected light returns on the reverse path and enters the beam splitter 32, where it changes its course at right angles and enters the photodiode 46 where it is converted into a current signal, and further converted into a second current-voltage conversion. The signal is converted by the circuit 48 into a voltage signal.

On the other hand, the light emitted from the laser diode 30 to the opposite side is received by the photodiode 34 as reference light and converted into a current signal, and this current signal is converted into a reference current by the first current-voltage conversion circuit 44. It is converted to a voltage signal.

When the chemical sensor 40 is placed in an atmosphere in which a substance to be detected such as hydrocarbons is present, the clad interacts with the substance to be detected, so that the optical characteristics of the clad change. This changes the condition of total reflection of the chemical sensor 40 and therefore the light transmission characteristics,
The intensity of the light reflected by and emitted from the chemical sensor 40 changes. Therefore, a predetermined processing circuit (not shown) compares the reference voltage signal output from the first current-voltage conversion circuit 44 with the voltage signal output from the second current-voltage conversion circuit 48. This makes it possible to know the presence of the substance to be detected.

Note that, as shown in FIG.
May be constituted by a combination of a laser diode 30 and a collimator lens 50, the optical fiber 18 may be omitted, and a glass plate 52 may be used instead of the beam splitter 32.

FIG. 3 shows a second embodiment of the seed detecting apparatus according to the present invention.
FIG. 3 is a view schematically showing the configuration of the embodiment, in which the light source 2, the light transmitting / extracting section 8, and the reflected light detecting section 10 are integrated to form a light emitting / receiving unit. The light emitting / receiving unit 54 in this embodiment is a light emitting / receiving integrated laser 56 to which a hologram is added (Japanese Patent Laid-Open No. 6-52588).
And a fiber receptacle with a collimator lens having one end coupled to an optical fiber 18 for transmitting the laser light from the integrated light emitting / receiving laser 56 and the light reflected and returned from the chemical sensor 40. FC
It has a structure in which the connector 58 is integrated.

In FIG. 3, the integrated light emitting / receiving laser 56 includes a laser diode 60 having an oscillation wavelength of, for example, 780 nm, and a photodiode (not shown) for monitoring the laser light emitted from the laser diode 60. Light receiving photodiode 62 for detecting light reflected back from the chemical sensor 40
And a hologram 64 that transmits the laser beam emitted from the laser diode 60 and bends the traveling direction of the reflected light returned from the chemical sensor 40 to be incident on the light-receiving photodiode 62. Are supported on a suitable platform.

The integrated laser 56 for emitting and receiving light is fixed to one end of an aluminum cylinder 66, and a collimator lens 68 for collimating the light transmitted through the hologram 64 is provided at an appropriate position in the cylinder 66 by an appropriate means. The lower end of the fiber receptacle FC connector 58 is fixed to the upper end of the cylinder 66. The end of the optical fiber 18 is drawn into the fiber receptacle FC connector 58 to a position where the laser light collimated by the collimator lens 68 is collected by the collimator lens 70.

The light emitting / receiving unit 54 shown in FIG.
In comparison with the configuration shown in FIG. 7, the laser diode 56 corresponds to the light source 2, the hologram 64 corresponds to the light transmitting / extracting section 8, and the light receiving photodiode 62 corresponds to the reflected light detecting section 10, respectively.

Since the seed detecting device of the second embodiment is configured as described above, the laser light emitted from the laser diode 60 passes through the hologram 64,
After being made parallel by the collimator lens 68, the light is condensed on one end of the optical fiber 18 by the collimator lens 70, propagates through the optical fiber 18, reaches the chemical sensor 40, and is reflected by the reflection film 44. The reflected light propagates along the reverse path, passes through the collimator lens 68, and enters the hologram 64. The hologram 64 bends the traveling direction of the incident light and focuses the light on the light receiving photodiode 62. By detecting the output signal intensity of the light receiving photodiode 52 at this time and performing appropriate processing, it becomes possible to detect the presence or absence of the substance to be detected.

The reflection-type seed detecting device has been described so far. Next, referring to FIG. 4, the transmission-type seed detecting device shown in FIG. This will be described as a third embodiment.

In FIG. 4, the light emitted from the laser diode 30 passes through the optical fiber 24 and passes through the chemical sensor 4.
The light incident on one end of the optical fiber 26 passes through the chemical sensor 40, enters the optical fiber 26 from the other end, propagates through the optical fiber 26, and reaches the second photodiode 46.

FIG. 5 shows an example of a structure in which the light source 2 and the reference light detecting section 22 are integrated, which can be used for the reflection type and transmission type seed detecting devices described above. In this structure, the laser diode 30 is replaced by L
An ED 30 'is used, and a phototransistor 34' is used instead of the photodiode 34. LED
Light emitted from 30 'enters optical fiber 18 or 24 and first phototransistor 34'. LED3
0 ′ is a transparent cylindrical member 7 having a recess 72 formed therein.
4, a lens 76 is integrally formed on the bottom surface of the concave portion 72 of the cylindrical member 74 in advance to collect light emitted from the LED 30 '. On the opening side of the concave portion 72, a metal body 80 having a reflecting surface 78 formed at 45 degrees with respect to the traveling direction of the light passing through the lens 76 is fixed. The end of the optical fiber 18 or 24 is a metal body 80
, One end of the optical fiber 18 or 24 is located on the reflection surface 78, and the light collected by the lens 76 enters. The first phototransistor 34 'is fixed at an appropriate position on the outer surface of the cylindrical member 74 so as to receive the light that has exited the lens 76 and reflected by the reflection surface 78.

The tubular member 74 can be made of, for example, a transparent acrylic material, and is preferably integrally molded with the LED 30 ′ and the lens 76 by plastic molding.

One important application of the reflective and transmissive species detection devices described in detail above is a system for remotely monitoring the presence and / or concentration of a substance to be detected.
FIG. 6 shows an outline of such a remote monitoring system.
In FIG. 6, chemical sensors 4 ₁ , 4 ₂ , 4 ₃ , 4 ₄ having a reflection film 6 at one end in the configuration shown in FIG. And alarm controller 8
Optical fiber 20 ₁ between the 2, 20 _2, 20 _3, 20 ₄ connected respectively. The alarm control unit 82 is installed at an appropriate location separated from the monitored location by a predetermined distance, and is connected to a data processing device 86 provided at a distant monitoring center 84 and a telephone line, a dedicated line, a wireless line, a satellite line, and the like. It is connected via an arbitrary communication line 88. The data processing device 86 is an arithmetic processing device such as a personal computer. If necessary, a relay station 90 may be installed in the communication line 88. A plurality of alarm control units 82 may be connected to the monitoring center 84 so that a plurality of different locations can be simultaneously monitored centrally.

FIG. 7 shows three chemical sensors 4 ₁ , 4 ₂ , 4
₃ is a block diagram illustrating a specific configuration example of an alarm control unit 82 connected via optical fibers 20 ₁ , 20 ₂ , and 20 ₃ . 6, alarm control unit 82 includes an optical fiber 20 _1, 20 _2, 20 ₃ three alarm control unit whose one end is connected to 92 _1, 92 _2, 92 _3, the overall operation of the alarm control unit 82 A control microprocessor 94 for controlling;
A modem 96 connected to the communication line 88, a memory 98 for storing monitoring data, an external input terminal 100 for inputting external information, and an alarm unit 102 for issuing an alarm are provided.

[0051] The alarm control unit 92 _1, 92 _2, 92 ₃ have the same configuration, each light emitting and receiving unit, an analog determination circuit and a display unit. Each light emitting / receiving unit converts the laser light into optical fibers 20 ₁ , 20 ₂ , 2
0 ₃ , and propagates through the chemical sensors 4 ₁ , 4 ₂ , 4 ₃ , receives the light reflected back by the reflection film 6 at one end of these chemical sensors, and converts it into an electric signal. I do. This electric signal is compared with an alarm threshold value and a trouble alarm threshold value, respectively, in an analog judgment circuit in order to determine the presence or absence of a substance to be detected and whether a trouble has occurred in a chemical sensor, an optical fiber, a light source, or the like. The judgment result in the analog judgment circuit is "No error",
"The substance to be detected exists" and "Sensor, optical fiber,
The control microprocessor 94 displays the result of the determination on a display unit in the alarm control unit so that the site manager can grasp the situation of the monitored location. . If necessary,
The determination result may be printed out.

The control microprocessor 94 temporarily stores the determination result in the analog determination circuit in the memory 98. When the determination result indicates that the chemical sensors 4 ₁ , 4 ₂ , and 4 ₃ are operating normally and that the substance to be detected does not exist, the control microprocessor 94 indicates the determination result at each predetermined time. The data is read from the memory 92 and sent to the monitoring center 84 via the modem 96 together with the site identification code. At this time, the control microprocessor 94 outputs the external data input from the external input terminal 100 (for example, the time when the power failure occurred, the time when the power failure was restored, and the like).
The monitoring center 8 is connected via the modem 96 and the communication line 88.
4 data processing device 86. The contents of the report to the monitoring center 84 can be set by using appropriate input means at the site and by sending a command from the data processing device 86 to the control microprocessor 94. Similarly, when setting or changing the value of the alarm threshold or the trouble alarm threshold, a new value is input at the site or the data processing device 86
From the control microprocessor 9 via the communication line 88
4 by sending a command.

On the other hand, when the judgment result of the analog judgment circuit indicates the presence of a substance to be detected or the occurrence of a trouble in a chemical sensor, an optical fiber, a light source, or the like, the control microprocessor 94 immediately activates the alarm unit 102. A warning is issued to urge the site manager to take action, and the occurrence of an abnormality is notified to the data processing device 86 via the modem 96 and the communication line 88.
Report to. Thereby, the data processing device 86 displays an abnormal message or activates an alarm lamp or a buzzer to urge the administrator to take an appropriate action. Therefore, it is possible to detect the occurrence of an abnormality at a distant point early.

In the above description, the description has been made assuming that a chemical sensor for chemically detecting the presence of a substance to be detected is used. Biological sensors may be used. In addition, when a substance to be detected exists, a chemical or biological sensor capable of detecting the concentration of the substance can be used.

[0055]

As apparent from the above, the present invention has been described in detail with reference to some embodiments, the seed detecting device of the present invention has a simple structure and can be manufactured at low cost. In addition to high reliability, the presence and / or concentration of the substance to be detected can be detected essentially safely. In addition, it is sufficient to install a sensor at the monitored location, connect the sensor to the light emitting / receiving unit with an optical fiber, and use the output from the light emitting / receiving unit to determine the occurrence of an abnormal state. Can be safely and early detected.

Further, since the data obtained from the sensor can be reported to a distant point, the monitored location can be monitored at all times, even during nights when the vehicle is unmanned. It becomes possible to do.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams schematically showing the configurations of a reflection-type seed detection device and a transmission-type seed detection device according to the present invention, respectively.

FIG. 2A is a diagram schematically showing a configuration of a first embodiment of a species detection device according to the present invention, and FIG.
This is an example in which some components of the first embodiment are changed.

FIG. 3 is a diagram schematically showing a configuration of a second embodiment of the species detection device according to the present invention.

FIG. 4 is a diagram schematically showing a configuration of a third embodiment of the species detection device according to the present invention.

FIG. 5 is a diagram showing an example of an integrated structure of a light source and a reference light detection unit, which can be used in the species detection device shown in FIGS. 2 and 4.

FIG. 6 is a schematic diagram of a remote monitoring system using the species detection device according to the present invention.

FIG. 7 is a block diagram schematically showing a specific configuration of an alarm control unit in FIG. 6;

FIG. 8 is a diagram schematically showing a configuration of an example of a conventional fuel vapor detector.

FIG. 9 is a schematic diagram of a known species detection device using a chemical sensor.

FIG. 10 is a view for explaining a configuration of the chemical sensor of FIG. 9;

[Explanation of symbols]

4: sensor, 6: reflective film, 14: core, 16: clad, 30: laser diode, 32: beam splitter, 34: first photodiode, 36: collimator, 38: connector, 44: first current- Voltage conversion circuit, 40: chemical sensor, 42: reflective film, 4
6: second photodiode, 48: second current-voltage conversion circuit, 50: collimator lens, 52: glass plate, 54: light emitting / receiving unit, 56: integrated light emitting / receiving laser, 60: laser diode , 62:
Light receiving photodiode, 54: hologram, 74:
Cylindrical member, 78: reflective surface, 80: metal body

[Procedure amendment]

[Submission date] March 15, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006] However, the fuel vapor detector shown in FIG. 8 has an optical fiber 202 between the light source 200 and the optical fiber 202.
It is necessary to arrange a collimator and a connector between the optical fiber 208 and the photodetector 210, respectively, between the optical fiber 208 and the photodetector 210, which not only complicates the configuration but also has the disadvantage of high cost. . In the species detection device shown in FIGS. 9 and 10, the photodetector 304 that operates electrically is disposed at one end of the chemical sensor 302.
Even with the explosion-proof construction, the concern about using it in a potentially explosive atmosphere remains.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akihiro Takaya 1-3-2 Minamidai, Kawagoe-shi, Saitama Inside Hoechst Research and Technology Co., Ltd. (72) James B. Stamatoff 1-3, Minamidai, Kawagoe-shi, Saitama -72 Hoechst Research and Technology Co., Ltd. (72) Inventor Ronald P. Fedora 1-3-2, Minamidai, Kawagoe-shi, Saitama Hoechst Research and Technology Co., Ltd.

Claims (10)

[Claims] 1. A species detection device for detecting at least one of the presence and concentration of a chemical or biological species, comprising: a light source; and a reflecting means at one end, wherein a predetermined light emitted from the light source is provided. Is a sensor that transmits light having the wavelength of the other end to the other end and transmits the light reflected by the reflection means in the reverse direction, and can measure the light transmission characteristics in the presence of a chemical or biological species. A sensor that causes a significant change, and is disposed between the light source and the other end of the sensor, and transmits light from the light source to enter the other end of the sensor, and is reflected by the reflection unit. And a light transmitting / extracting unit for outputting reflected light transmitted in the opposite direction to the sensor. 2. A reference light detection unit 22 for generating a reference signal corresponding to light emitted from the light source 2; and the reflected light from the light transmission / extraction unit 8 and the reference light from the reference light detection unit 22. The apparatus according to claim 1, further comprising: a reflected light processing unit (10) configured to process the reference light and generate a signal corresponding to the reflected light. 3. The seed detecting device according to claim 1, wherein said reflection means is a reflection film provided on one end of said optical fiber element. 4. A light emitting / receiving unit in which the light source, the light transmitting / extracting unit, and the reflected light detecting unit are integrated, and an optical transmission path is provided between the light emitting / receiving unit and the sensor. The species detection device according to claim 1, wherein the species detection device is combined. 5. The light emitting / receiving unit includes: a laser diode; and an optical element for supplying light generated by the laser diode to the optical transmission path and transmitting the reflected light output from the optical transmission path. The seed detection according to claim 4, further comprising: a system; a photodiode for receiving the reflected light from the optical system; and a hologram for condensing the reflected light on the photodiode. apparatus. 6. A species detection device for detecting at least one of the presence and concentration of a chemical or biological species, comprising: a light source 2; and a light having a predetermined wavelength emitted from the light source 2. A sensor 4 receiving at one end and outputting at the other end, wherein the sensor 4 produces a measurable change in light transmission characteristics in the presence of a chemical or biological species. Seed detection device. 7. A reference light detection unit 22 for generating a reference signal corresponding to light emitted from the light source 2. processing a transmitted light output from the sensor 4 and the reference light to convert the transmitted light into a transmitted light; The apparatus according to claim 6, further comprising a transmitted light processing unit (12) for generating a corresponding signal. 8. The optical fiber element having a core and a cladding surrounding the core, wherein at least a portion of the cladding has an optical property at the portion in response to the chemical or biological species. The species detection device according to any one of claims 1 to 7, wherein the species detection device is made of a material that changes the optical transmission characteristics of the optical fiber element. 9. The seed detection device according to claim 2, wherein the sensor is disposed at a monitored location, and a predetermined number is determined from the sensor and the monitored location. A distant monitoring system in which an alarm control unit at a distance is coupled with an optical fiber, wherein in the alarm control unit, in the reflection type seed detection device, the light source, the light transmission / extraction unit, and the reference The light detection unit and the reflected light processing unit are provided, and in the transmission type seed detection device, the light source, the reference light detection unit, and the transmitted light processing unit are provided, and the alarm control unit is provided. Based on a signal output from the reflected light processing unit or the transmitted light processing unit, whether an abnormal state including the sensor trouble and the presence of the chemical or biological species at the monitored location has occurred. Has a judgment circuit for judging A remote monitoring system, wherein the alarm control unit is connected to a monitoring center via communication means, and monitors the occurrence of the abnormal condition from the monitoring center. 10. The alarm control unit further includes: a memory for storing data indicating a determination result by the determination circuit; and a data stored in the memory when the determination result does not indicate occurrence of an abnormal state. At a predetermined time interval, and reporting means for immediately reporting to the distant point when the determination result indicates that an abnormal state has occurred. 9. The remote monitoring system according to item 9.