JP2014010072A - Optical in-liquid particle detection device and in-liquid particle detection method - Google Patents

Abstract

An optical submerged particle detector capable of responding to a change in the refractive index of a liquid is provided.
[Solution]
Light source 1 that emits inspection light, conversion means 21 that converts inspection light into parallel light, light source side translucent member 10 through which inspection light converted into parallel light passes, and light source side translucent member 10 are transmitted The condensing reflecting mirror 31 that reflects the inspection light toward the focal point, the light source side translucent member 10 and the condensing reflecting mirror 31 and a region including the focal point of the condensing reflecting mirror 31 are filled with the liquid. The housing 2 configured as described above, the ejection mechanism 3 that ejects a fluid containing particles at the focal point of the condensing reflector 31, and the scattered light or fluorescence generated when the particles contained in the fluid are irradiated with the inspection light. An optical liquid particle detection device comprising: a light detection unit 4 for detection.
[Selection] Figure 1

Description

  The present invention relates to an environmental evaluation technique, and more particularly to an optical liquid particle detection device and a liquid particle detection method.

  In a clean room such as a bioclean room, scattered particles are detected and recorded using a particle detection device (see, for example, Non-Patent Document 1). From the particle detection result, it is possible to grasp the deterioration of the air conditioner in the clean room. In addition, a detection record of particles in the clean room may be attached to a product manufactured in the clean room as a reference material.

  The optical particle detection device, for example, sucks a gas in a clean room and irradiates the sucked gas with excitation light. When the gas contains particles, the particles irradiated with the excitation light emit fluorescence or autofluorescence (hereinafter referred to as “fluorescence” together with “fluorescence” and “autofluorescence”). The wavelength and intensity of the fluorescence emitted by the particle depend on the type of particle. Therefore, by observing the wavelength or intensity of the fluorescence emitted by the particles, it is possible to specify the type of particles scattered in the clean room. In addition, the optical particle detection device can also specify the concentration and size of particles by analyzing scattered light generated by irradiating the particles with light.

  Furthermore, in beverage manufacturers, pharmaceutical manufacturers, water purification plants, and the like, an optical particle detection device may be used to detect particles contained in a liquid (see, for example, Patent Documents 1 to 3). .

JP 2008-39405 A JP 2006-250686 A JP 2002-243620 A

Hasegawa, M. et al., “Real-time microorganism detection technology in the air and its application”, Yamatake Corporation, azbil Technical Review December 2009, p.2-7, 2009

  In a particle detector that detects fine particles in a liquid atmosphere, the refractive index of the liquid may change. Accordingly, an object of the present invention is to provide an optical submerged particle detection device and a submerged particle detection method that can cope with a change in the refractive index of the liquid.

  According to the aspect of the present invention, (a) a light source that emits inspection light, (b) a conversion unit that converts inspection light into parallel light, and (c) a light source side transmission through which inspection light converted into parallel light is transmitted. Surrounded by a light-transmitting member, (d) a condensing reflecting mirror that reflects the inspection light transmitted through the light source-side translucent member toward the focal point, and (e) a light-source-side translucent member and a condensing reflecting mirror. A region including the focal point of the light reflecting mirror is configured to be filled with a liquid, (f) an ejection mechanism for ejecting a fluid containing particles at the focal point of the condensing reflecting mirror, and (g) included in the fluid There is provided an optical in-liquid particle detection device comprising: a light detection unit that detects scattered light or fluorescence generated by irradiating particles to be irradiated with inspection light.

  Further, according to the aspect of the present invention, (a) emitting inspection light, (b) converting inspection light into parallel light by the conversion means, and (c) parallel light to the light source side translucent member. Allowing the inspection light to enter the region filled with the liquid surrounded by the light source side translucent member and the condensing reflecting mirror facing the light source side translucent member by transmitting the converted inspection light; (D) reflecting the inspection light toward the focal point in the region filled with the liquid by the condensing reflecting mirror; and (e) ejecting the fluid containing the particles at the focal point of the condensing reflecting mirror. And (f) detecting a scattered light or fluorescence generated by irradiating the particles contained in the fluid with the inspection light.

  According to the present invention, it is possible to provide an optical submerged particle detection device and a submerged particle detection method that can cope with a change in the refractive index of a liquid.

It is a 1st schematic diagram of the optical submerged particle detector which concerns on the 1st Embodiment of this invention. It is a 2nd schematic diagram of the optical submerged particle detection apparatus which concerns on the 1st Embodiment of this invention. It is a 1st schematic diagram which shows the fixing method of the light source side translucent member in the optical liquid particle detection apparatus which concerns on the 1st Embodiment of this invention. It is a 2nd schematic diagram which shows the fixing method of the light source side translucent member in the optical type particle | grain detection apparatus which concerns on the 1st Embodiment of this invention. It is a 3rd schematic diagram which shows the fixing method of the light source side translucent member in the optical liquid particle detection apparatus which concerns on the 1st Embodiment of this invention. It is a 4th schematic diagram which shows the fixing method of the light source side translucent member in the optical liquid particle detection apparatus which concerns on the 1st Embodiment of this invention. It is a 1st schematic diagram of the optical submerged particle detection apparatus which concerns on the 2nd Embodiment of this invention. It is a 2nd schematic diagram of the optical submerged particle detection apparatus which concerns on the 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic. Therefore, specific dimensions and the like should be determined in light of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(First embodiment)
As shown in FIG. 1, the optical particle detection device according to the first embodiment includes a light source 1 that emits excitation light as inspection light, conversion means 21 that converts excitation light into parallel light, and conversion into parallel light. The light source side translucent member 10 through which the excitation light transmitted, the condensing reflecting mirror 31 that reflects the excitation light transmitted through the light source side translucent member 10 toward the focus, the light source side translucent member 10, and The region surrounded by the condensing reflector 31 and including the focal point of the condensing reflector 31 is a casing 2 configured to be filled with liquid, and the jet that ejects fluid containing particles at the focal point of the condensing reflector 31 The mechanism 3 and the light detection part 4 which detects the fluorescence which generate | occur | produces when the particle | grains contained in the fluid are irradiated with excitation light are provided. Here, the particles include microorganisms, harmless or harmful chemical substances, dust, dust, dust and the like.

  For example, a light emitting diode (LED) can be used as the light source 1, but is not limited thereto. The excitation light emitted from the light source 1 may be visible light or ultraviolet light. When the excitation light is visible light, the wavelength of the excitation light is, for example, in the range of 400 to 410 nm, for example, 405 nm. When the excitation light is ultraviolet light, the wavelength of the excitation light is, for example, in the range of 310 to 380 nm, for example, 355 nm. A controller that sets the intensity and wavelength of excitation light emitted from the light source 1 and a power supply device that supplies a power supply current to the light source 1 are connected to the light source 1.

  The conversion means 21 is disposed relative to the light source 1, for example. The conversion means 21 is a parallel light lens capable of converting diffused light or radiated light into parallel light, for example. The light source side translucent member 10 is disposed to face the conversion means 21. The light source side translucent member 10 is a flat plate arranged perpendicular to the optical axis of the conversion means 21 which is a parallel light lens. The light source side translucent member 10 is made of the same material as the optical lens, for example.

  The condensing / reflecting mirror 31 is disposed on the optical axis of the conversion means 21 that is a parallel light lens, and is opposed to the light source side translucent member 10. As the condensing reflection mirror 31, a parabolic mirror or a spherical mirror having a single radius of curvature can be used. Further, as shown in FIG. 2, an off-axis parabolic mirror or off-axis spherical mirror may be used as the condensing / reflecting mirror 32. The condenser reflectors 31 and 32 are manufactured by coating polished glass with a metal such as aluminum (Al) or gold (Au). Or the condensing reflecting mirrors 31 and 32 are manufactured by machining a metal material such as aluminum and stainless steel with a diamond cutting needle or the like. The excitation light emitted from the light source 1 is converted into parallel light by the conversion means 21 and enters the condensing reflector 31. The excitation light is reflected by the condensing / reflecting mirror 31 and condensed at the focal point of the condensing / reflecting mirror 31.

  Furthermore, the optical particle detector shown in FIG. 1 includes a detection-side translucent member 11 whose optical axis passes through the focal point of the condensing reflector 31. For example, the optical axis of the detection-side translucent member 11 is substantially orthogonal to the optical axis of the conversion means 21 at the focal point of the condenser reflector 31. The detection side translucent member 11 is, for example, a concave lens. The detection side translucent member 11 is made of the same material as that of the optical lens, for example.

  The housing 2 is configured to be surrounded by the light source side translucent member 10, the condensing reflection mirror 31, and the detection side translucent member 11 so that the region including the focal point of the condensing reflection mirror 31 is filled with liquid. ing. The light source side translucent member 10, the condensing reflecting mirror 31, and the detection side translucent member 11 seal the area surrounded by them, and prevent the filled liquid from leaking outside. Specifically, the light source side translucent member 10 prevents liquid from leaking to the conversion means 21 side. Moreover, the detection side translucent member 11 prevents the liquid from leaking to the light detection unit 4 side.

  The ejection mechanism 3 sucks fluid from the outside of the housing 2 by a pump or the like, and ejects the sucked fluid toward the focal point of the condensing reflector 31 through a nozzle or the like. The fluid may be a liquid or a gas. For example, the traveling direction of the fluid ejected from the ejection mechanism 3 is set substantially perpendicular to the optical axis of the condensing / reflecting mirror 31. Here, if the fluid contains particles, the particles irradiated with the excitation light emit fluorescence. For example, when the particles are microorganisms including bacteria, tryptophan, nicotinamide adenine dinucleotide, riboflavin, and the like included in the microorganisms emit fluorescence when irradiated with excitation light.

  Examples of bacteria include gram negative bacteria, gram positive bacteria, and fungi including mold spores. Examples of gram-negative bacteria include E. coli. Examples of gram positive bacteria include Staphylococcus epidermidis, Bacillus subtilis spores, Micrococcus, and Corynebacterium. Examples of fungi containing mold spores include Aspergillus. The airflow crossing the excitation light collected by the condensing reflector 31 is exhausted to the outside of the housing 2 by the exhaust mechanism.

  The fluorescence emitted by the particles passes through the detection-side translucent member 11. Further, in the housing 2, the fluorescence emitted by the particles between the focal point of the condensing reflector 31 and the light detection unit 4, and the fluorescence transmitted through the detection-side translucent member 11 is converted into parallel light. A detection system parallel light lens 41 and a detection system condensing lens 43 that condenses the fluorescence converted into parallel light by the detection system parallel light lens 41 toward the light detection unit 4 are arranged. For example, the detection system parallel light lens 41 is arranged so that the optical axis passes through the focal point of the condenser reflector 31. Between the detection system parallel light lens 41 and the detection system condenser lens 43, a wavelength selection element 42 that transmits only specific fluorescence may be arranged. As the wavelength selection element 42, a band pass filter such as a long pass filter can be used. As the light detection unit 4, a photodiode, a photomultiplier tube, or the like can be used. For example, a computer that statistically processes the detected fluorescence intensity is connected to the light detection unit 4.

  In the optical particle detection device according to the first embodiment described above, the excitation light incident on the condensing / reflecting mirror 31 is condensed at the focal point of the condensing / reflecting mirror 31 without chromatic aberration. Therefore, even if the wavelength of the excitation light is changed according to the particle to be detected, there is no need to change the optical system other than the light source 1 of the excitation light or the flow path of the air flow in which particles can be contained. . Therefore, it is possible to detect and identify many types of particles at a low cost.

  Further, at least one of the conversion means 21, which is a parallel light lens, the detection system parallel light lens 41, and the detection system condenser lens 43 may be an achromatic lens. An achromatic lens is configured by combining two or more lenses having different refractive indexes and light dispersions (Abbe numbers). For example, an achromatic lens is configured by combining a convex lens made of crown glass with a concave lens made of flint glass. By using at least one of the conversion means 21, which is a parallel light lens, the detection system parallel light lens 41, and the detection system condensing lens 43 as an achromatic lens, it is possible to further correct chromatic aberration.

  Furthermore, in the optical particle detection device according to the first embodiment, an area surrounded by the housing 2, the light source side translucent member 10, the condenser reflector 31, and the detection side translucent member 11 is defined. It is possible to fill with a liquid. Therefore, it is possible to detect fine particles present in the liquid. In addition, in the optical particle detection device according to the first embodiment, the excitation light converted into parallel light enters the light source side translucent member 10 which is a flat plate. Therefore, even if the refractive index of the liquid changes due to a change in the composition of the liquid filled therein or a change in the wavelength of the excitation light, the condensing point of the excitation light collected by the condensing reflecting mirror 31 changes. do not do. Therefore, according to the optical particle detector according to the first embodiment, it is not necessary to adjust the optical system even if the composition of the liquid filled therein is changed or the wavelength of the excitation light is changed. It becomes.

  For example, as shown in FIG. 3, the light source side translucent member 10 has an O-ring (O-ring) or the like at a division position of the housing 2 that can be divided in a direction perpendicular to the optical axis of the conversion means 21. It is sandwiched via the elastic gasket 30. The elastic gasket 30 to which a force is applied in the axial direction is in close contact with the divided side surface of the housing 2 and the side surface of the light source side translucent member 10. Thereby, the area | region with which a liquid is filled is sealed. In addition, as shown in FIG. 4, elastic gaskets 30 may be disposed on both sides of the light source side translucent member 10. Alternatively, as shown in FIG. 5, the light source side translucent member 10 is press-fitted into a recess provided at a division position of the housing 2 and having an outer diameter substantially the same as the outer diameter of the light source side translucent member 10. May have been. Furthermore, as shown in FIG. 6, the light source side translucent member 10 press-fitted into one side of the divided casing 2 is placed on the other side of the divided casing 2 through an elastic gasket 30. It may be inset. The method of fixing the detection side translucent member 11 to the housing 2 is also the same.

(Second Embodiment)
As shown in FIG. 7, the optical particle detection apparatus according to the second embodiment uses a concave mirror such as an off-axis paraboloidal mirror or an off-axis spherical mirror as the conversion means 22. When the excitation light is ultraviolet light, there is a problem that the transmittance is low when a lens is used as the conversion means 22. In addition, the lens may emit fluorescence. On the other hand, when an off-axis parabolic mirror or off-axis spherical mirror is used as the conversion means 22, there is no problem of a decrease in the transmittance of ultraviolet rays or generation of fluorescence from the lens that may occur when using the lens.

  Also in the second embodiment, a parabolic mirror or a spherical mirror having a single curvature radius can be used as the condensing reflecting mirror 31. Alternatively, as shown in FIG. 8, an off-axis parabolic mirror or off-axis spherical mirror may be used as the condensing reflector 32. Other components of the optical particle detection device according to the second embodiment are the same as those in the first embodiment.

(Other embodiments)
As mentioned above, although this invention was described by embodiment, it should not be understood that the description and drawing which form a part of this indication limit this invention. From this disclosure, various alternative embodiments, embodiments, and operation techniques should be apparent to those skilled in the art. For example, in the first and second embodiments, an example in which fluorescence is detected by irradiating particles with excitation light as inspection light has been described. On the other hand, the scattered light generated by irradiating the particles with the inspection light is converted into parallel light by the detection system parallel light lens 41, and the parallel light derived from the scattered light is collected by the detection system condenser lens 43 toward the light detection unit 4. May shine. The intensity of light scattered by the particles correlates with the particle size of the particles. Therefore, by detecting the intensity of the light derived from the scattered light by the light detection unit 4, it is possible to obtain the particle size of the particles to be detected. Thus, it should be understood that the present invention includes various embodiments and the like not described herein.

DESCRIPTION OF SYMBOLS 1 Light source 2 Housing | casing 3 Injection mechanism 4 Light detection part 10 Light source side translucent member 11 Detection side translucent member 21, 22 Conversion means 30 Elastic gasket 31, 32 Condensing reflecting mirror 41 Detection system parallel light lens 42 Wavelength selection Element 43 Condensing lens for detection system

Claims (20)

A light source that emits inspection light;
Conversion means for converting the inspection light into parallel light;
A light source side translucent member that transmits the inspection light converted into the parallel light; and
A condensing reflector that reflects the inspection light transmitted through the light source side translucent member toward the focal point;
A housing that is surrounded by the light source side translucent member and the condenser reflector and includes a focal point of the condenser reflector, and is configured to be filled with liquid;
An ejection mechanism for ejecting a fluid containing particles at the focal point of the condenser reflector;
A light detection unit for detecting scattered light or fluorescence generated by irradiating particles contained in the fluid with the inspection light; and
An optical submerged particle detector. A detection-side translucent member disposed between the light detection unit and the focal point of the condenser reflector;
The casing is configured so that the liquid is filled between the light source side translucent member, the condensing reflector, and the detection side translucent member.
The optical liquid particle detecting device according to claim 1.   The optical in-liquid particle detection device according to claim 1, wherein the light source side translucent member is a flat plate.   The optical liquid particle detection device according to claim 1, wherein the detection-side translucent member is a concave lens.   The optical liquid particle detection device according to any one of claims 1 to 4, wherein the condensing reflection mirror is a parabolic mirror.   The optical submerged particle detection device according to claim 1, further comprising an achromatic lens disposed between the detection-side translucent member and the light detection unit.   The optical liquid particle detection device according to claim 1, wherein the conversion unit is a parallel light lens.   The optical liquid particle detection device according to any one of claims 1 to 6, wherein the conversion means is a concave mirror.   The optical submerged particle detection device according to claim 8, wherein the concave mirror is an off-axis parabolic mirror.   The optical liquid particle detection device according to claim 8, wherein the concave mirror is an off-axis spherical mirror. Emitting inspection light,
Converting the inspection light into parallel light by a conversion means;
Fills the light source side translucent member with the liquid surrounded by the light source side translucent member and the condensing reflecting mirror facing the light source side translucent member so that the inspection light converted into the parallel light is transmitted. Making the inspection light incident on a region where
Reflecting the inspection light toward the focal point in the region filled with the liquid by the condenser reflector;
Injecting a fluid containing particles at the focal point of the condenser reflector;
Detecting scattered light or fluorescence generated by irradiating the particles contained in the fluid with the inspection light;
A method for detecting particles in a liquid, comprising: Further comprising transmitting the scattered light or fluorescence to a detection-side translucent member,
The liquid is filled between the light source side translucent member, the condensing reflector, and the detection side translucent member.
The method for detecting particles in a liquid according to claim 11.   The method for detecting particles in liquid according to claim 11 or 12, wherein the light source side translucent member is a flat plate.   The method for detecting particles in liquid according to any one of claims 11 to 13, wherein the detection-side translucent member is a concave lens.   The method for detecting particles in liquid according to any one of claims 11 to 14, wherein the condensing reflector is a parabolic mirror.   The method for detecting particles in liquid according to claim 11, wherein detecting the scattered light or fluorescence includes causing the scattered light or fluorescence to enter an achromatic lens.   The method for detecting particles in liquid according to any one of claims 11 to 16, wherein the conversion means is a parallel light lens.   The method for detecting particles in liquid according to any one of claims 11 to 16, wherein the conversion means is a concave mirror.   The method for detecting particles in liquid according to claim 18, wherein the concave mirror is an off-axis parabolic mirror.   The method for detecting particles in liquid according to claim 18, wherein the concave mirror is an off-axis spherical mirror.

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