JP3771417B2 - Fine particle measurement method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a fine particle measurement suitable for detecting a minute amount of fine particles having a size of several microns (μm) to a submicron (μm) or a size of several tens of nanometers (nm) mixed in a large volume of fluid (medium). The present invention relates to a method and an apparatus thereof, and in particular, scans in parallel a normally emitted thin laser beam mixed with coherent multi-wavelength light, or a fine and strong light beam having a laser spot diameter of several hundred μm or less. A wide laser light irradiation area is created, and a wide measurement field of view is formed together with the light scattering detector by the particle, and this is used to identify multiple shapes and dimensions of fine particles, the particle size for each composition, and each The present invention relates to a fine particle measurement method and apparatus capable of instantaneously measuring the position of each shape / size particle at the same time.
[0002]
[Prior art]
Conventionally, microscopic observation is well known as a technique for observing the shape, size, and the like of fine particles. For example, in order to detect Cryptosporidium protozoa with a size of several μm in a few liters of tap water, conventionally, a large amount of tap water is filtered through a filter to catch foreign substances, and these foreign substances are colored and microscopes are used. The protozoa were detected while observing. However, the method of detecting the shape and size of particles with a human eye using a microscope is difficult to identify for a long time, and it is difficult to objectively identify depending on the level of proficiency of humans. Cost.
[0003]
When protozoa or biological cells are to be detected by a particle size measurement method such as light scattering, the M1E scattering particle count method is usually used (several hundred μm). ^Three Although the particle diameter is estimated from the scattered light intensity of cell particles or the like entering a minute measurement volume, particle shape cannot be identified by such a normal light scattering method.
[0004]
Furthermore, in the multiple matched filter method, which is a particle shape identification method developed by the present inventors, the measurement field of view is small, and in order to introduce fine particles to be measured that are three-dimensionally widely distributed in space to the measurement field of view. The measuring device itself must be moved or the particles must be sucked into a fine measuring field, which requires a lot of time for the measurement.
[0005]
In the two-beam photothermal deflection spectroscopy, which is a method for measuring the size of ultrafine particles by composition, the laser beam is focused by a lens to make a measurement field of view, so only particles in the fine measurement field can be measured. If the deflection position detection for this is performed on the Fourier transform plane, it is not known that the deflection position can be easily measured, and there is no appropriate method of light detection for probe light deflection position measurement, and a complicated photoelectric measurement system is not used. In other words, the particle size measurement is difficult.
[0006]
For this reason, in order to measure the size and shape of fine particles such as living cells by the conventional method, detection of weak light scattering intensity and particle image processing must be performed with a small field of view. In addition, enormous amounts of measurement time and labor are required to measure the shape, size, and composition of a minute amount of fine particles present in a large-capacity medium. Was almost impossible.
[0007]
On the other hand, in recent years, the development of measurement methods in the ultra-small field of view has been just started for the measurement of particle sizes by composition, such as biological cells in the order of nm and drug particles. In particular, technology to quickly detect from a large amount of water whether Cryptosporidium protozoa, etc. are present in the source of tap water, non-contact particles of cedar pollen suspended in the atmosphere from a large amount of air Such as technology for quick measurement with a vacuum, non-contact rapid automatic measurement technology for house mites as allergen particles in the air aspirated by a vacuum cleaner, particles by shape and size of several μm or more present in a large amount of medium The conventional non-contact rapid measurement cannot be solved by the conventional technique, and the development of the technique is urgently required socially. In addition, as advanced medical technology, technology development that enables measurement of liposomes ranging from several nanometers to several hundred nanometers that carry drugs and genes to cell receptors, and observation of interaction of antibodies and drugs with cell receptors is performed in medicine and pharmacy. There is an urgent need for both biology and other academic and social issues.
[0008]
[Problems to be solved by the invention]
The present invention has been made to solve the urgent medical and social problems as described above, and is characterized by a normally emitted thin laser beam mixed with coherent multi-wavelength light, or A laser beam with a small laser spot diameter of several hundred μm or less and a strong light intensity is scanned in parallel to create a wide laser light irradiation area, and together with a particle light scattering detector, a wide measurement field of view is formed. Identifying multiple shapes and dimensions of particles from light scattering and light diffraction patterns of fine particles, and measuring the particle size for each composition and the location of each shape and size from photothermal deflection spectroscopy at the same time. is there.
[0009]
The simultaneous identification of the particle shape and particle diameter can be identified from the shape and spread of the light diffraction pattern by the particles. Specifically, the shape and size of the particle group is identified by a multiple matched filter method using a multiple matched filter that is a single hologram. The multiple matched filter is a hologram in which light diffraction patterns from a plurality of reference particle groups having the shape and size of a particle group to be identified are mounted. In the conventional multiple matched filter method, particles entering the front focal plane of the convex lens in the parallel light beam of a normal or enlarged single laser are identified, but the measurement field of view is not necessarily wide. In the present invention, the particle shape and particle size can be measured as long as the particle to be measured is not in the front focal plane of the lens but in the irradiation laser beam of parallel scanning wherever the focal plane in the measurement container is off. The reason is that the light diffraction pattern from the particles has the same shape and the same spread on the back focal plane of the Fourier transform lens wherever there are particles of the same shape and size. If a filter is installed, it is sufficient to use the fact that identification autocorrelation light appears at a point-symmetrical position on the back focal plane of the image forming lens installed after the matched filter. If the particle to be measured is before or after the focal plane in the measurement container, the appearance position (focus position) of the autocorrelation light is before or after Fa3.
[0010]
In addition, measurement of the particle size for each particle composition and the location of each shape and size of the particle makes it possible to resonate with the probe light, which is strong with the probe light, which is weak in light intensity but does not change with time and has a constant intensity. When pump light that is easily aligned is irradiated with the optical axis aligned, the pump light is resonantly absorbed by the particles and the particles are heated, and the probe light that is irradiated coaxially to the particles is bent according to the particle size due to the refractive index change due to heat. It is done. By using this photothermal deflection spectroscopy, the photothermal deflection from the particle is automatically detected on the back focal plane of the convex lens, or the light intensity is converted, and the particle diameter size and location are automatically detected from the deflection angle. Enable measurement.
[0011]
The present invention provides means for performing the above two methods simultaneously in a three-dimensional manner with a large field of view. That is, a large-field measurement method in which coherent pump light and probe coherent multi-wavelength light (at least two-wavelength laser light) are mixed coaxially and scanned in parallel to intentionally create a large field of view and irradiate the identified particles. Do. The reason for parallel irradiation with laser light is that when fan scanning of the light beam is performed, the light beam scanning regions overlap or do not scan, and fan scanning differs in the temporal existence density of light beams in space and is the same type This is because the intensity per unit time of scattered light varies depending on the space even if it is a diameter particle, which makes accurate particle measurement difficult. The reason for further parallel scanning is to facilitate the configuration of the light receiving optical system.
[0012]
The irradiation laser light may be a strong expanded parallel light beam such as a sheet-like parallel light instead of the scanning light. Furthermore, in order to identify the particle group in the large field of view at the same time, the shape and size of the light scattering and light diffraction pattern by the particle in the wide field of measurement , The particle size by composition is collected at one point by a unique light receiving optical system with a wide field of view by combination of pump light, identified by one multiple matched filter or position gradient light intensity filter, and simultaneously by CCD array sensor Judge by real time.
[0013]
When focusing on the identification of the particle shape, a method may be adopted in which the identified particles flow through the shear flow path to control the posture. That is, a laser beam (or an expanded parallel laser beam) that is one-dimensionally scanned perpendicularly to the flow from the bottom by forming a horizontally wide channel by forming the transparent glass channel narrow in the vertical width and parallel in the top and bottom. The fine particles present in the irradiated and flowing medium must be sure to cross the scanning laser beam. The flow path is configured to apply a shearing force to the medium flowing in the parallel flat glass to control the posture of the flow path in the medium. When the particle whose posture is controlled passes through the scanning laser beam, an optical diffraction pattern appears in the pump light. If the light diffraction pattern of the pump light is received by a Fourier transform optical system composed of a convex lens having a large aperture with the center of the flow path as the front focal point, the light of the pump light from each flow path is formed on the rear focal plane of the convex lens. Diffraction patterns appear overlapping on the center of the optical axis of the convex lens. If this is identified by a single multiple matched filter, the size and shape of the particle group appear in point symmetry with the particle location in each particle shape identification region as a bright spot of autocorrelation light in real time. When these correlated light groups are captured by a high-speed CCD camera with an image intensifier and displayed on a display, the presence positions of particles for each shape and size are measured in-site. It is also possible to digitally process the signal from the high-speed CCD camera and display on the computer screen where the particles of each shape and size exist. A short focus lens array or a relay lens system in which a short focus convex lens and a relatively long convex lens are combined may be placed in front of the Fourier transform optical system.
[0014]
When the particle to be measured is very small on the order of nm, the light diffraction pattern cannot be used for identification. Therefore, multi-beam photothermal deflection spectroscopy is used for particle size classification. The particle measuring container may be made of relatively wide and deep transparent glass. Coherent multi-wavelength coaxial laser light is scanned in parallel in the container, and the scanned light is observed by the same optical system as the forward light scattering measurement optical system. When fine particles enter the scanning parallel light beam, the pump light is resonantly absorbed and the probe light is deflected by the photothermal effect. If the deflection of the probe light is collected by a Fourier transform optical system composed of a convex lens, and further condensed by a convex lens through a position-gradient light intensity filter installed on the rear focal plane of the convex lens, the particles on the rear focal plane of the last convex lens The light spot of the identification signal light appears at a point-symmetrical position with respect to the particle position at a light intensity proportional to the size of. For the particle size identification, the position gradient light intensity filter is set so that the probe light deflected outside the optical axis in accordance with the particle size is set so that the light transmittance increases toward the outside from the optical axis. Is installed on the Fourier transform plane of the signal light. This is because the deflected light from the same size particle always passes through the same position on the Fourier transform plane, regardless of where the particle is in the measurement field of view. The deflected light that has passed through the position-gradient light intensity filter is further condensed by a convex lens with the Fourier transform surface as the front focal point, and the particle image is sized symmetrically with the position where the particle to be measured was located on the rear focal plane of the lens. Appears with proportional light intensity. In this way, the present invention constructs an original system that can simultaneously identify the size and position of particles for each composition.
[0015]
[Means for Solving the Problems]
Therefore, the problem solving means adopted by the present invention is:
A laser beam mixed with coherent multi-wavelength light is scanned in parallel to create a wide laser light irradiation area, a fluid to be inspected is flowed in the laser light irradiation area, and light scattering of particles in the measurement field of the fluid is performed. Identification of multiple shapes and dimensions of particles from light diffraction patterns Also, This is a fine particle measurement method characterized by simultaneously measuring the size and location of particles by composition from photothermal deflection spectroscopy.
The laser beam is a fine particle measuring method characterized in that the laser beam is a fine laser beam having a laser spot diameter of several hundreds μm or less and a high light intensity.
The particle scattering method is characterized in that the light scattering and diffraction patterns of the particles are measured by a multiple matched filter.
Further, the photothermal deflection spectroscopy of the particles is measured by a position gradient intensity filter.
Also, a laser beam that is coaxially mixed with the coherent pump light and the probe light laser beam and emitted onto the optical rail, a scanning unit that scans the laser beam in parallel, and a target that is disposed behind the scanning unit. A measurement fluid, a light-shielding plate that absorbs a light beam transmitted through the fluid to be measured, and photothermal deflection spectroscopy of the particles of the fluid to be measured. Measurement of particle size and location by composition It is a fine particle measuring device characterized by comprising a position inclination intensity filter for performing.
Also, a laser beam that is coaxially mixed with the coherent pump light and the probe light laser beam and emitted onto the optical rail, a scanning unit that scans the laser beam in parallel, and a target that is disposed behind the scanning unit. A measurement fluid, a light-shielding plate that absorbs a light beam that has passed through the fluid to be measured, a half mirror that separates light scattering and light diffraction patterns from the particles of the fluid to be measured and photothermal deflection spectroscopy of the particles in the fluid to be measured; Multiple matched filters that identify multiple shapes and dimensions of particles from light scattering and light diffraction patterns of particles in the fluid under measurement, and particle size and location measurement from photothermal deflection spectroscopy of particles in the fluid under measurement A fine particle measuring apparatus comprising a position gradient intensity filter.
Also, a laser beam that is coaxially mixed with the coherent pump light and the probe light laser beam and emitted onto the optical rail, a scanning unit that scans the laser beam in parallel, and a target that is disposed behind the scanning unit. A measurement fluid, a light-shielding plate that absorbs a light beam that has passed through the fluid to be measured, a half mirror that separates light scattering and light diffraction patterns from the particles of the fluid to be measured and photothermal deflection spectroscopy of the particles in the fluid to be measured; Multiple matched filters that identify multiple shapes and dimensions of particles from light scattering and light diffraction patterns of particles in the fluid under measurement, and particle size and location measurement from photothermal deflection spectroscopy of particles in the fluid under measurement A position gradient intensity filter, a convex lens having a front focal point on the multiple matched filter, a convex lens having a front focal point on the inclined light intensity filter, and a front lens on the multiple matched filter. And a modified diffraction grating filter disposed on the front side adjacent to the convex lens having a point, and a modified diffraction grating filter disposed on the front side adjacent to the convex lens having the front focal point on the tilted light intensity filter. A fine particle measuring apparatus comprising an imaging device on a back focal plane.
The half mirror is a dichroic mirror that transmits or reflects only a specific wavelength.
The scanning means may be a galvanometer mirror, a silicon micro light scanner, or a polygon mirror.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an optical system configuration diagram of the fine particle measuring apparatus according to the first embodiment that measures the composition, shape, particle size, spatial distribution, behavior, etc. of particles. is there.
[0017]
In the figure, 1 is a single optical rail, 2 is a pump light source mounted on the optical bench, 3 is a probe light source 3 placed on the optical bench, and the pump light source 2 and the probe light source 3 have a strong single mode. Laser beam is emitted. An optical scanning mirror (for example, a galvanometer mirror) 5 and a convex lens 6 are disposed on the optical rail, and a flow path 7 through which the fluid to be measured flows and a light shielding plate 8 that absorbs a parallel light beam are disposed behind the convex lens 6. . A half mirror 9 for separating the probe light and the pump light is disposed behind the light shielding plate 8. Further, on the transmission optical axis of the half mirror 9, the front focal point F 1 is provided in the flow path 7, and the rear focal point is provided. A convex lens 10 having a value Fa2 is disposed. A multiple matched filter 12 for identifying the shape and size of the particles is disposed at the position of the rear focal point Fa2 of the convex lens 10. Further, the convex lens 11 on the reflection optical axis of the half mirror 9 has a deflection angle corresponding to the particle size. An inclined light intensity filter 13 and a convex lens 15 that extract a proportional light intensity are arranged. The multi-matched filter 12 is a reference-shaped particle placed at the measurement position of the identification light in the flow path with the photosensitive surface of the photoconductive plastic hologram (PPH) automatic developing device placed on the back focal plane of the convex lens 10. Holograms created by light scattering or light diffraction patterns emitted from the light source can be used. At this time, the reference light for creating the hologram is a half mirror 16, mirrors 24 and 25, a convex lens 17, a mirror 18, a convex lens 19, a mirror 20, and the like. It is made to irradiate as expansion parallel light created using. The identified signal light groups appearing around the back focal points Fa3 and Fb3 of the convex lenses 14 and 15 are captured by a CCD camera or the like, respectively, and the measurement result can be displayed on the data processing / display unit.
[0018]
The operation of the particle measuring apparatus having the above configuration will be described. Strong single mode pump light and probe light emitted from the lasers 2 and 3 mounted on the optical bench are half mirror 16 and mirrors 21, 22, and 23. Is used to make a single laser beam mixed with the optical axis aligned, and irradiates the galvanometer mirror 5 through the convex lens 4 having a relatively long focal length. The laser beam reflected by the galvanometer mirror 5 passes through the convex lens 6, does not spread in a fan shape, is parallel and larger than the object to be identified, and is a strong light beam having a diameter determined by the ratio of the focal lengths of the convex lens 4 and convex lens 6. It is scanned one dimensionally in parallel.
The rear focal plane of the convex lens 4 and the front focal point of the convex lens 6 are both on the optical scanning mirror 5.
[0019]
The scanning light beam is irradiated two-dimensionally in a cross section orthogonal to the flow from the side surface of the flow path 7 that flows vertically (flows in a direction perpendicular to the paper surface of the drawing). That is, the channel 7 is scanned perpendicular to the flow direction. The flow path 7 is formed of parallel plane glass, and the flow path 7 may be wide or may be a shear flow path with narrow left and right widths. The reason for narrowing the width on the left and right is that the particles suspended in the fluid are made to flow in the shear flow and the posture is controlled. The scanning light beam can also have a certain angle with the orthogonal direction to the flow. This angle is such that when an object to be identified that is long in the flow path direction passes through the flow path, the spread of the light diffraction pattern thereby extends in a direction perpendicular to the flow path, so that the light diffraction pattern is hindered by the light shielding plate 8 described later. Due to no consideration. The one-dimensional parallel light beam to be scanned passes through the glass side wall of the flow path 7, passes through the opposite side glass wall, and is absorbed by the light shielding plate 8.
[0020]
When particles flowing through a flow path formed of parallel flat glass enter the scanning parallel light flux, the particles generate an optical diffraction pattern or photothermal deflection light.
That is, an optical diffraction pattern is observed from particles having a size of submicron or larger, and probe light is subjected to photothermal deflection when pump light is resonance absorption light of particles of submicron or smaller. The light diffraction pattern or photothermal deflection light passes through the half mirror 9 and is collected by the convex lens 10 and / or the convex lens 11 installed with the center of the flow path of the scanning light crossing the flow path as the front focal point.
[0021]
Specifically, the half mirror 9 is configured as a dichroic mirror that reflects only a specific wavelength, thereby reflecting the probe light component of the scattered light from the particles or the photothermal deflection spectroscopic light, and transmitting the pump light component. The diffracted light of the pump light and the deflected light or diffracted light of the probe light are projected onto the rear focal planes Fa2 and Fb2 of the lens by the convex lens 10 or the convex lens 11, respectively. As shown in FIG. 2, particles having the same composition and shape and size are diffracted light on the focal planes Fa2 and Fb2 at the same position with the same shape and divergence angle, as shown in FIG. The light appears at the same position at the same deflection angle and centered on each optical axis. Therefore, if the multiple matched filter 12 is installed on the Fa2 surface and the inclined light intensity filter 13 is installed on the Fb2 surface, the diffracted light is identified by the multiple matched filter, and the correlated light as the identification signal is detected by the convex lens 14. And appear for each identification region of the shape and size of the particle. In FIG. 2, the appearance position (focal position) of the autocorrelation light by the measured particles entering before or after the focal plane F1 in the measurement container is before or after Fa3. In addition, the photothermal deflection spectroscopy passes through the gradient light intensity filter, and a light intensity proportional to the deflection angle corresponding to the particle size is obtained, which is condensed by the convex lens 15 and proportional to the particle size around the back focal plane. An intense light spot appears in point symmetry with the particle position. The front focal points of the convex lenses 14 and 15 are on Fa2 and Fb2, respectively. Therefore, the position of each particle shape and size can be determined by the appearance position of the autocorrelation bright spot, and the particle size by composition is divided by the intensity and position of the deflected light image.
[0022]
The multiple matched filter is formed from reference shaped particles placed at the measurement position of the identified particles in the flow path with the photosensitive surface of the photoconductive plastic hologram (PPH) automatic developing device placed on the back focal plane of the convex lens 10. It may be a hologram created by light scattering or light diffraction pattern. At this time, the reference light for creating the hologram may be irradiated with expanded parallel light created using the half mirror 16, the convex lens 17, the mirror 18, the convex lens 19, the mirror 20, and the like as shown in the figure. Further, the signal light groups to be identified that appear around the back focal points Fa3 and Fb3 of the lenses 14 and 15 are captured by a CCD camera or the like, and the measurement results are displayed on the data processing / display unit.
[0023]
If a small light-shielding film is placed in the center of the optical axis and the zero-order light is shielded, light scattering, light diffraction patterns, or photothermal deflection light from particles entering the measurement field of view formed by a scanning parallel light beam and a convex lens can be observed more clearly. Is done. If the information light from the particles hits each optical filter, the particle shape and particle size information and the information for each particle size with a specific composition are automatically identified in parallel in real time, and the specified shape, composition, and particle size Each identification number appears for each identification region as autocorrelation light and deflection signal light. By looking at these signal lights, it is possible to measure in real time when and what shape and particle size of particles, and where a particle with a specific composition has passed by size.
[0024]
Next, another embodiment of the present invention will be described. FIG. 3 is a second embodiment, FIG. 4 is a configuration diagram of an optical system of the third embodiment, and the second embodiment is the same as the first embodiment. A measurement method and apparatus for identifying a plurality of shapes and dimensions of particles from an optical diffraction pattern, and the third embodiment is a method and apparatus for measuring particle size and location from photothermal deflection spectroscopy in the first embodiment. This is an independent optical system, and the same reference numerals are used for the same members as in the first embodiment in the figure.
[0025]
In the second embodiment, the strong single-mode pump light and probe light emitted from the lasers 2 and 3 mounted on the optical bench become one laser beam as in the first embodiment, and the focal lengths are compared. An optical scanning mirror (galvanometer mirror) 5 is irradiated through a long convex lens 4. The laser beam reflected by the galvanometer mirror 5 passes through the convex lens 6 and is scanned in parallel one-dimensionally as a strong light beam having a diameter determined by the ratio of the focal lengths of the convex lens 4 and the convex lens 6. The scanning light beam is irradiated two-dimensionally from the side surface of the flow path 7 that flows perpendicularly in a cross section orthogonal to the flow, passes through the glass side wall of the flow path 7, passes through the opposite side glass wall, and is absorbed by the light shielding plate 8.
[0026]
Further, when particles flowing through a flow path formed of parallel flat glass enter the scanning parallel light flux, an optical diffraction pattern is generated by the particles. The light diffraction pattern is condensed by a convex lens 10 installed with the central portion of the flow path of the scanning light crossing the flow path as the front focal point, and projected onto the rear focal plane Fa2. If the multiple matched filter 12 is installed on the Fa2 surface, the correlated light generated by the diffracted light irradiated to the multiple matched filter appears in each particle shape / size identification region, thereby causing light scattering and light diffraction. A plurality of shapes and dimensions of particles can be identified from the pattern.
[0027]
In the third embodiment, the strong single mode pump light and the probe light emitted from the lasers 2 and 3 become one laser beam and are applied to the optical scanning mirror (galvano mirror) 5. The laser beam reflected by the galvanometer mirror 5 passes through the convex lens 6 and is scanned in parallel one-dimensionally as a strong light beam having a diameter determined by the ratio of the focal lengths of the convex lens 4 and the convex lens 6. The scanning light beam is irradiated two-dimensionally from the side surface of the flow path 7 that flows perpendicularly in a cross section orthogonal to the flow, passes through the glass side wall of the flow path 7, passes through the opposite side glass wall, and is absorbed by the light shielding plate 8.
[0028]
When particles flowing through a flow path formed of parallel flat glass enter the scanning parallel light flux, the particles generate an optical diffraction pattern or photothermal deflection light.
For ultrafine particles of submicron or less, the probe light is subjected to photothermal deflection when the pump light is the resonant absorption light of the particles. The photothermal deflection light is condensed by the convex lens 10 installed with the flow path center of the scanning light crossing the flow path as the front focal point, and is projected onto the rear focal plane Fb2. When the tilted light intensity filter 13 is installed on the Fb2 surface, the photothermal deflection spectroscopy passes through the tilted light intensity filter 13 and becomes a light intensity proportional to the deflection angle corresponding to the particle size, which is condensed by the convex lens 15, and the same lens. A light spot having an intensity proportional to the particle size around the back focal plane 15 appears on the back focal plane Fb3 or on the front and rear surfaces thereof in a point symmetry with the particle position. Each of the identified signal light groups is captured by a CCD camera or the like and processed, and the measurement result is displayed on the display.
[0029]
Further, the measurement of the three-dimensional position of the correlation signal light group for displaying the identification result is performed by a scanning mirror or a modified diffraction grating filter having a function of shifting the position before and after the light convergence in the horizontal direction. This example (fourth embodiment) is shown in FIG. In FIG. 5, reference numerals 34 and 35 denote modified diffraction grating filters arranged on the front side adjacent to the convex lenses 14 and 15, and other configurations are the same as those in the first embodiment.
In this optical system, the deviation in the depth of focus direction of the identification signal light is shifted in the direction perpendicular to the scanning light direction by the modified diffraction grating filter installed adjacent to the convex lens 14 or the convex lens 15. The focal point is set on the Fa3 and Fb3 surfaces. Therefore, when the same diameter particles are measured in the large visual field measurement region, the position of the particle detection signal light differs from the position of the irradiation light scanning direction in the irradiation light scanning direction with respect to the optical axis center of the Fa3 or Fb3 surface. The difference in the particle position in the focal depth direction, which is shifted symmetrically, appears as a position shift in the direction perpendicular to the light irradiation direction, and thus the three-dimensional position of the correlated signal light group displaying the identification result can be measured.
[0030]
As described above, in the embodiment according to the present invention, a method for identifying a plurality of shapes and dimensions of particles from light scattering and light diffraction patterns of fine particles in a measurement visual field, a particle size for each composition and each shape and dimension from multi-beam photothermal deflection spectroscopy. Although the form which measures simultaneously the identification method which measures the presence position for every particle | grains separately or separately was demonstrated, the position of the light scattering shown in FIG. 1, optical diffraction pattern optical system Fa2, multi-beam photothermal deflection | distribution identification optical system Fb2 Can also be replaced.
In each of the above-described embodiments, the laser light emitted toward the optical scanning mirror is described as having two wavelengths, but this laser light can also be coherent multi-wavelength light. By doing so, it is possible to widen the limit of the identified particles.
In addition, the present invention can be implemented in any other form without departing from the spirit or main features thereof. Therefore, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner.
[0031]
【The invention's effect】
As described above in detail, according to the present invention, the spatial distribution of microparticles and the behavior of the particle group can be quantitatively measured in a two-dimensional large field of view, and three-dimensional by scanning the two-dimensional field of view. Quantitative measurement of the spatial distribution and behavior of particles in a large field of view.
In addition, particle shape measurement, spatial distribution / number density for each shape / size, behavior for each particle shape / particle size, or particle size for each particle composition can be measured.
Furthermore, the particle shape and size can be accurately measured regardless of the refractive index of each particle.
Specifically, for example, the presence of Cryptosporidium protozoa in the source water of tap water can be quickly detected from a large amount of water, or particles such as cedar pollen suspended in the atmosphere can be detected in a large amount of air. It is possible to quickly measure without contact from the inside, and to quickly measure house mites as allergen particles in the air sucked by a vacuum cleaner without contact. As described above, the present invention is effective for solving urgent medical and social problems, has a large demand as industrial technology, can be widely used, and the ripple effect of the present invention is very great. There is an effect.
[Brief description of the drawings]
FIG. 1 is an optical system configuration diagram of a fine particle measuring apparatus that measures particle composition, shape, particle size, spatial distribution, behavior, and the like according to a first embodiment of the present invention.
FIG. 2 shows that the same shape and size of particles in the measurement field are the same on the focal planes Fa2 and Fb2, the diffracted light has the same shape and divergence angle, and the photothermal deflection light has the same deflection. It is a figure explaining appearing centering on each optical axis in the same position by a corner.
FIG. 3 is a configuration diagram of an optical system according to a second embodiment.
FIG. 4 is a configuration diagram of an optical system according to a third embodiment.
FIG. 5 is a configuration diagram of an optical system according to a fourth embodiment.
[Explanation of symbols]
1 Optical rail
2 Pump light source
3 Probe light source
4 Convex lens
5 Galvano mirror
6 Convex lens
7 Channel
8 Shading plate
9 Half mirror
10 Convex lens
11 Convex lens
12 Multiple matched filters
13 Inclined light intensity filter
14 Convex lens
15 Convex lens
16 half mirror
17 Convex lens
18 Mirror
19 Convex lens
20 mirror
34, 35 Modified diffraction grating filter

Claims (9)

A laser beam mixed with coherent multi-wavelength light is scanned in parallel to create a wide laser light irradiation area, a fluid to be inspected is flowed in the laser light irradiation area, and light scattering of particles in the measurement field of the fluid is performed. A method for measuring fine particles, wherein a plurality of particle shapes and dimensions are identified from an optical diffraction pattern, and the size and position of each particle by composition are simultaneously measured from photothermal deflection spectroscopy. 2. The fine particle measuring method according to claim 1, wherein the laser light beam is a fine laser beam having a laser spot diameter of several hundred μm or less and a high light intensity. Claim 1 or particle measurement method in claim 2 serial mounting, wherein the light scattering or diffraction pattern for measuring by multiple matched filter of the particles. 4. The fine particle measuring method according to claim 1, wherein the photothermal deflection spectroscopy of the particles is measured by a position gradient intensity filter. A laser beam that is coaxially mixed with coherent pump light and probe laser beam and emitted onto the optical rail, a scanning unit that scans the laser beam in parallel, and a fluid to be measured disposed behind the scanning unit And a light shielding plate that absorbs the light flux that has passed through the fluid to be measured, and a position gradient intensity filter that measures the size and location of the particles by composition from the photothermal deflection spectroscopy of the particles of the fluid to be measured. A fine particle measuring apparatus. A laser beam that is coaxially mixed with coherent pump light and probe laser beam and emitted onto the optical rail, a scanning unit that scans the laser beam in parallel, and a fluid to be measured disposed behind the scanning unit A light-shielding plate that absorbs the light flux that has passed through the fluid to be measured, a half mirror that separates light scattering and light diffraction patterns from the particles of the fluid to be measured and photothermal deflection spectroscopy of the particles in the fluid to be measured, Multiple matched filters that identify multiple shapes and dimensions of particles from light scattering and light diffraction patterns of particles in the measurement fluid, and positions where particle size and location are measured from photothermal deflection spectroscopy of particles in the fluid under measurement A fine particle measuring apparatus comprising a gradient intensity filter. A laser beam that is coaxially mixed with coherent pump light and probe laser beam and emitted onto the optical rail, a scanning unit that scans the laser beam in parallel, and a fluid to be measured disposed behind the scanning unit A light-shielding plate that absorbs the light flux that has passed through the fluid to be measured, a half mirror that separates light scattering and light diffraction patterns from the particles of the fluid to be measured and photothermal deflection spectroscopy of the particles in the fluid to be measured, Multiple matched filters that identify multiple shapes and dimensions of particles from light scattering and light diffraction patterns of particles in the measurement fluid, and positions where particle size and location are measured from photothermal deflection spectroscopy of particles in the fluid under measurement An inclined intensity filter, a convex lens 14 having a front focal point on the multiple matched filter, a convex lens 15 having a front focal point on the inclined light intensity filter, and the multiple matched filter A modified diffraction grating filter 34 disposed on the front side adjacent to the convex lens 14 having the focus, and a modified diffraction grating filter 35 disposed on the front side adjacent to the convex lens 15 having the front focus on the inclined light intensity filter 13 are provided. In addition, the fine particle measuring apparatus further includes an imaging device on the back focal plane of each of the convex lenses 14 and 15. 8. The particle measuring apparatus according to claim 6, wherein the half mirror is a dichroic mirror that transmits or reflects only a specific wavelength. 9. The particle measuring apparatus according to claim 6 , wherein the scanning unit is a galvanometer mirror, a silicon micro light scanner, or a polygon mirror.

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