JP2005164560A - Dark-field particle measurement device and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dark-field particle measurement method and a device for it, capable of visualizing the Brownian movement of submicron particles which are smaller than the wavelength of visible light for measuring the position and movement amount of each particle for measurement of the particle size and the coefficient of viscosity. <P>SOLUTION: Light flux from a light source 3 is converged by a collector lens 4 and formed into a cylindrical zone light by means of a zone optical system 5 to be collected to a sample liquid, including particles by means of a condenser lens 6. The scattered light from a sample body 7 is received by an object lens 8, having a focal distance larger than that of the condenser lens 6. The image from the object lens 8 is magnified by a projection optical system 9 to be received by a CCD sensor 10. An acquired dark field image is measured by an image processing flow meter 11 for finding the number, the position, and the moving amount of the particles. In a computing circuit 12, diffusion time using a means movement distance of the particles and the field time interval of the CCD sensor is substituted in the Einstein-Stokes relation related to the Brownian movement, and then the particle size is found and displayed by a display device 13. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention uses a dark field illumination method to image-analyze a visualized image of scattered light from fine particles in a liquid and measure the average moving distance due to Brownian motion of the fine particles, thereby obtaining an average particle diameter, The present invention relates to a dark field fine particle measuring apparatus and a dark field fine particle measuring method for measuring diameter distribution, number of particles, particle space distribution, particle velocity and viscosity coefficient of liquid.

  Conventionally, the fine particle measurement method, which analyzes the Brownian motion of fine particles dispersed in a solution to measure the particle behavior and particle size distribution, takes a fine particle image with a transmission optical microscope or a two-dimensional image sensor, and the area of the particle portion. There is an image processing method that measures particle behavior and particle size distribution by quantifying the particle size, and the particle size distribution of fine particles can be determined by measuring and analyzing scattered light and interference light generated by irradiating a sample with laser light. There are laser diffraction scattering method and dynamic light scattering method to measure.

  Among them, the dynamic light scattering method has been reported to measure the diffusion coefficient of Brownian motion of fine particles of sub-micron and obtain the particle size by measuring the fluctuation due to Brownian motion of particles using coherent laser light. (For example, see Patent Document 1, Patent Document 2, and Patent Document 3.)

  In addition, a particle size measurement method by moving image processing based on dynamic light scattering theory is disclosed (for example, see Non-Patent Document 1).

The inventor has disclosed the technical contents related to the present invention (see, for example, Non-Patent Document 2 and Non-Patent Document 3).
JP 2002-22642 (page 3-4, FIG. 1) JP 2001-76637 A (page 2-4, FIG. 1) JP-A-7-72066 (Pages 7-18, Fig. 1) Satoshi Kimura and 3 others, “Evaluation of submicron particle size by moving image processing based on dynamic light scattering theory”, 1993, IEICE Transactions Vol. J76-D-II, No. 9, p. 1987-1993 Junichiro Matsushita and 4 others, “Brownian motion and cluster formation of non-magnetic fine particles in magnetic fluid”, November 15, 2003, Japan Society of Mechanical Engineers Thermal Engineering Conference Proceedings, p. 431-432 Junichiro Matsushita and 4 others, “Brownian motion and particle size measurement of ferromagnetic nanoparticles”, May 28, 2003, Proceedings of the 40th Japan Heat Transfer Symposium, p. 815-816

  However, the conventional image processing method has a problem that the particle size that can be measured using transmitted light is about 300 nm, and it is difficult to image particles having a particle size of less than 300 nm.

  Further, the above-described conventional dynamic light scattering method has a problem that handling is difficult by using laser light, and the apparatus is complicated and expensive.

  In addition, it is difficult to measure the particle size of fine particles in an opaque fluid due to the attenuation of the scattered light and laser light scattering intensity, and noise due to multiple scattering cannot be avoided in high concentration fine particle measurement. There is a problem that it is difficult to measure.

The present invention has been made in view of such problems,
Visualize Brownian motion of fine particles in transparent and opaque fluids, measure the number and amount of particles, calculate particle size, and confirm temporal and spatial changes in particle size distribution, easy to handle and inexpensive An object of the present invention is to provide a dark field fine particle measuring apparatus and a dark field fine particle measuring method.

  Another object of the present invention is to provide a dark field fine particle measuring apparatus and a dark field fine particle measuring method capable of measuring high concentration fine particles and measuring the spatial distribution of particle size distribution and the viscosity coefficient of fluid. To do.

  The dark field fine particle measuring apparatus of the present invention includes a light source, a collector lens that collects a light beam from the light source, an annular optical system that forms the light beam from the collector lens into a cylindrical annular light, and an annular optical device. A condenser lens that collects the light flux from the system, a specimen placed at the focal point of the condenser lens, an objective lens having a focal length longer than the focal length of the condenser lens, and a projection optical system that enlarges an image from the objective lens, A CCD sensor that receives the image from the projection lens, an image processing velocimeter that analyzes the image from the CCD sensor to determine the number of particles and the amount of movement, and a signal from the image processing velocimeter to analyze the velocity and particle size of the particle An arithmetic circuit for obtaining a diameter, an image processing velocimeter, and an output device for outputting statistics regarding particle behavior from the arithmetic circuit.

  The dark field fine particle measuring apparatus and dark field fine particle measuring method of the present invention include a step of condensing a light beam from a light source by a collector lens, and a cylindrical light beam from the collector lens by an annular optical system. The step of forming the annular light, the step of condensing the light of the annular light beam on the specimen installed at the focal point of the condenser lens, and the objective lens having a focal length longer than the focal length of the condenser lens from the specimen body The process of receiving scattered light, the process of enlarging and projecting the image from the objective lens with the projection optical system, the process of receiving the image from the projection optical system with the CCD sensor, and the image processing of the image from the CCD sensor Image analysis with an anemometer to determine the number and amount of particles, Image processing to analyze the number and amount of particles with an arithmetic circuit to determine the particle velocity and particle size, and image processing From fast meter and arithmetic circuits and has a step of displaying statistics about the particle behavior in the display device.

  The dark field fine particle measuring apparatus and dark field fine particle measuring method of the present invention are the following Einstein-Stokes relational expressions relating to the Brownian motion in the first invention or the second invention.

で表される微粒子の平均移動距離に、画像処理流速計により画像解析された微粒子の移動量および拡散時間を用いて微粒子の直径ｄを算出することを特徴とするものである。

The diameter d of the fine particles is calculated using the movement amount and diffusion time of the fine particles image-analyzed by the image processing velocimeter for the average fine particle movement distance represented by

  Further, the dark field fine particle measuring apparatus and dark field fine particle measuring method of the present invention includes a step of performing image analysis by mixing fine particles with a known particle diameter in a fluid with an unknown viscosity coefficient, and analyzing the Brownian motion of the fine particles. And calculating the viscosity coefficient of the fluid.

The present invention has the following effects.
According to the dark field fine particle measuring apparatus and the dark field fine particle measuring method of the first aspect of the invention, since the dark field image processing is performed, the fine particle detection from the surrounding image can be easily performed even in a relatively dark image. it can. In addition, since an inexpensive light source such as a halogen lamp can be used and optical components can be reduced, it can be preferably used for a wide range of applications.

  According to the dark field fine particle measuring apparatus and dark field fine particle measuring method of the second aspect of the present invention, the adjustment state of the sample can be confirmed on the monitor screen before the start of the particle size measurement from the dark field image with high contrast. In addition, since the concentration of the fine particles can be monitored before the start of the particle size measurement, the concentration can be adjusted before the start of the particle size measurement, and measurement can be performed with an optimum dispersion state and concentration. In addition, since skill is not required for measurement, the present invention contributes to next-generation research that deals with microfluidic, nanofluidic, and microbial flow analysis.

  According to the dark field fine particle measuring apparatus and dark field fine particle measuring method of the third aspect of the present invention, the field time interval of the CCD camera can be changed in the image analysis. Can change.

  According to the dark field fine particle measuring apparatus and dark field fine particle measuring method of the fourth aspect of the present invention, the measurement is performed by mixing fine particles with a known particle diameter in a fluid with an unknown viscosity coefficient, Since the viscosity coefficient can be measured, it is possible to measure the viscosity coefficient of a fluid such as a colloidal fluid in which the viscosity coefficient is relatively difficult to determine.

The best mode for carrying out the present invention will be described below with reference to the drawings.
First, the best mode for carrying out the first invention according to the dark field fine particle measuring apparatus and the dark field fine particle measuring method will be described. FIG. 1 illustrates the apparatus of the present invention.

  The present invention provides a dark-field fine particle measuring apparatus and a dark-field fine particle measuring method capable of measuring the particle diameter using an inexpensive light source. This dark-field fine particle measuring apparatus is shown in FIG. As shown, the processing unit 1 and the measurement unit 2 are included.

  The light beam obtained from the light source 3 is collected by the collector lens 4.

  Parallel light in the annular optical system 5 is formed from the light flux from the collector lens.

  The annular light formed by the annular optical system 5 is condensed at the focal length A in the condenser lens 6. A specimen body 7 containing fine particles is fixed at the focal point of the condenser lens 6, and the annular light condensed by the condenser lens 5 passes through the specimen body 7 containing fine particles at the focal length of the condenser lens 6.

  An image of scattered light from fine particles in the specimen 7 at the focal point of the condenser lens 6 is obtained by the objective lens 8 having a focal length longer than that of the condenser lens 6.

  The image from the objective lens 8 is doubled by the projection optical system 9 and received by the CCD sensor 10.

  In the CCD sensor 10, the presence of the fine particles is confirmed by the image processing velocimeter 11 based on the scattered light from the fine particles in the specimen 6, and image analysis is performed to calculate the position and movement amount of the fine particles.

  From the position and movement amount of the fine particles from the image processing velocimeter 11, the number, speed and particle size of the fine particles are calculated in the arithmetic circuit 12.

  The position, amount of movement, speed and particle size of the fine particles calculated by the image processing velocimeter 11 and the arithmetic circuit 12 are displayed on the display device 11.

From the above, according to the best mode for carrying out the present invention,
Visualize the Brownian motion of fine particles in transparent and opaque fluids, measure the velocity and velocity distribution of individual particles, measure the particle size of the fine particles from the velocity and velocity distribution, and Since the change can be measured, a dark field fine particle measuring apparatus and a dark field fine particle measuring method that are easy to handle and inexpensive can be provided.

  The present invention is not limited to the best mode for carrying out the above-described invention, and various other configurations can be adopted without departing from the gist of the present invention.

  Next, the best mode for carrying out the second invention according to the dark field fine particle measuring apparatus and the dark field fine particle measuring method will be described. FIG. 2 illustrates the method of the present invention.

When measurement is started by 1, as shown in 2, a light beam is oscillated from the light source.
As shown in FIG.
As shown in FIG. 4, light from the light source is formed into cylindrical annular light.
As shown in FIG. 5, the annular light is condensed by a condenser lens.
As shown in FIG. 6, scattered light from the specimen is received by an objective lens having a focal length longer than the focal length of the condenser lens.
As shown in FIG. 8, the image from the objective lens is confirmed and adjusted with the eyepiece, and the focus is adjusted.
As shown in FIG. 9, the light from the objective lens is projected by the projection lens.
As shown in FIG. 10, the image from the projection lens is received by the CCD sensor, the image is confirmed, and if the particle concentration is not appropriate, the process returns to 7.
As shown in FIG. 11, the image from the CCD sensor is processed.
As shown in FIG. 12, the number of particles, position, and velocity are calculated from the image analysis result.
As shown in FIG. 13, the particle diameter is calculated by an arithmetic circuit.
As shown in FIG. 14, statistical data such as particle concentration, position, velocity, particle size, etc. are displayed as images.
End at 15.

From the above, according to the best mode for carrying out the present invention,
Visualize the Brownian motion of fine particles in transparent and opaque fluids, measure the velocity and velocity distribution of individual particles, measure the particle size of the fine particles from the velocity and velocity distribution, and Since the change can be measured, a dark field fine particle measuring apparatus and a dark field fine particle measuring method that are easy to handle and inexpensive can be provided. Also, since the concentration of fine particles can be monitored before the start of measurement, a dark field fine particle measuring device and a dark field fine particle measuring method capable of adjusting the concentration before the measurement is started and measuring at the optimum dispersion state and concentration are provided. can do.

  The present invention is not limited to the best mode for carrying out the above-described invention, and various other configurations can be adopted without departing from the gist of the present invention.

  Next, the best mode for carrying out the third invention according to the dark field fine particle measuring apparatus and the dark field fine particle measuring method will be described. FIG. 3 illustrates the method of the present invention.

When measurement is started by 1, light is oscillated from the light source as shown in 2.
As shown in FIG.
As shown in FIG. 4, light from the light source is formed into cylindrical annular light.
As shown in FIG. 5, the annular light is condensed by a condenser lens.
As shown in FIG. 6, scattered light from the specimen is received by an objective lens having a focal length longer than the focal length of the condenser lens.
As shown in FIG. 8, the image from the objective lens is confirmed and adjusted with the eyepiece, and the focus is adjusted.
As shown in FIG. 9, the light from the objective lens is projected by the projection lens.
As shown in FIG. 10, the image from the projection lens is received by the CCD sensor, the image is confirmed, and if the particle concentration is not appropriate, the process returns to 7.
As shown in FIG. 11, the image from the CCD sensor is processed.
As shown in FIG. 12, the number of particles, position, and velocity are calculated from the image analysis result.
As shown in FIG. 13, the particle diameter is calculated by substituting the average movement distance of the particles and the diffusion time using the field time interval of the CCD camera into the Einstein-Stokes relational expression relating to the Brownian motion by the arithmetic circuit.
As shown in FIG. 14, statistical data such as particle concentration, position, velocity, particle size, etc. are displayed as images.
End at 15.

From the above, according to the best mode for carrying out the invention,
Visualize the Brownian motion of submicron particles smaller than the wavelength of visible light, measure the position and amount of each individual particle, and the Einstein-Stokes relational equation for Brownian motion is the average particle movement distance and CCD camera field time interval. Since the particle diameter is calculated by substituting the diffusion time using, the particle diameter can be measured efficiently.

  Further, since the field time interval of the CCD camera can be changed in the image analysis, the dynamic range of the speed region that can be measured can be changed.

  The present invention is not limited to the best mode for carrying out the above-described invention, and various other configurations can be adopted without departing from the gist of the present invention.

  Next, the best mode for carrying out the fourth invention according to the dark field fine particle measuring apparatus and the dark field fine particle measuring method will be described.

When measurement is started by 1, light is oscillated from the light source as shown in 2.
As shown in FIG.
As shown in FIG. 4, light from the light source is formed into cylindrical annular light.
As shown in FIG. 5, the annular light is condensed by a condenser lens.
As shown in FIG. 6, scattered light from the specimen is received by an objective lens having a focal length longer than the focal length of the condenser lens. At this time, fine particles having a known particle diameter are mixed in the specimen.
As shown in FIG. 8, the image from the objective lens is confirmed and adjusted with the eyepiece, and the focus is adjusted.
As shown in FIG. 9, the light from the objective lens is projected by the projection lens.
As shown in FIG. 10, the image from the projection lens is received by the CCD sensor, the image is confirmed, and if the particle concentration is not appropriate, the process returns to 7.
As shown in FIG. 11, the image from the CCD sensor is processed.
As shown in FIG. 12, the number of particles, position, and velocity are calculated from the image analysis result.
As shown in FIG. 13, the viscosity coefficient is calculated by substituting the average moving distance of the particles and the diffusion time and the particle size using the CCD camera field time into the Einstein-Stokes relational expression relating to the Brownian motion by the arithmetic circuit.
As shown in FIG. 14, the viscosity coefficient is displayed as an image.
End at 15.

From the above, according to the best mode for carrying out the invention,
Viscosity of a fluid such as a colloidal fluid, whose viscosity coefficient is relatively difficult to determine, can be measured by mixing fine particles with a known particle diameter in a fluid with an unknown viscosity coefficient. The coefficient can be measured.

  The present invention is not limited to the best mode for carrying out the above-described invention, and various other configurations can be adopted without departing from the gist of the present invention.

  Next, specific examples of the present invention will be described. However, it goes without saying that the present invention is not limited to these examples.

  Here, an example of particle behavior and particle distribution of standard particles in water is shown.

  The measurement unit apparatus of FIG. 5 and the apparatus of FIG. 6 were used. A small amount of sample was added to the specimen on a slide glass. A halogen lamp was used as the light source, and a commercially available oil-immersed dark field condenser lens (OLYMPUS U-DCW) was used as the annular optical system and condenser lens. The optical microscope used was a biological microscope (OLYMPUS BX50) and the objective lens was a universal plan apochromat lens (OLYMPUS UPlanApo100 × / 1.35 Oil Iris). Only scattered light from the particles is imaged through the objective lens, and matching oil having the same refractive index as that of the glass is filled between the condenser lens and the slide glass to improve the optical accuracy. Microscopic images are taken from a high-speed monochrome CCD camera (FHOTRON FASTCAM-Net) installed in the tower, a bitmap image recorded in the primary memory is taken in via a personal computer, and a particle image is obtained using an image processing velocimeter. Analysis was performed, and the motion analysis of fine particles was performed. The particle size distribution was calculated from the position and speed of the obtained fine particles by a personal computer of an arithmetic unit. The obtained image analysis results are shown in FIG. Moreover, the particle size distribution obtained from the image analysis result is shown in FIG. As a result, an extremely high-contrast image was obtained, and it can be seen that the measurement of the particle size of the fine particles was performed with extremely high resolution.

From the above, according to the present embodiment, an image having a higher contrast than that of the conventional apparatus can be obtained. Therefore, even in a relatively dark image, particle detection from the surrounding image can be easily performed, and the particles can be efficiently collected. The diameter can be measured.
Also, from the dark field image with high contrast, the adjustment state of the sample can be confirmed on the monitor screen before the start of measurement.
Further, the dynamic range of the speed region that can be measured can be changed by changing the field time interval of the CCD camera in image analysis.
Moreover, the viscosity coefficient of a fluid can be measured by mixing and measuring fine particles with a known particle diameter in a fluid with an unknown viscosity coefficient.
Further, since an inexpensive light source such as a halogen lamp can be used and the number of optical components can be reduced, the apparatus can be simplified and economical.

In the above description, the dark field fine particle measuring apparatus and the dark field fine particle measuring method are described using one CCD sensor for measuring the particle behavior, but the present invention is not limited to this. For example, by using two CCD sensors, it is possible to efficiently measure as a three-dimensional vector by image processing.
Further, since the measurement unit and the processing unit are separated, the measurement unit can be remotely operated.

  The subject to be measured is the thermal behavior, particle size measurement, and viscosity measurement of fine particles, but it is not limited to these fine particle measurements, it is not limited to the measurement of water quality in circulating water and water supply of reactors, impurities such as sewage facilities and sewage facilities. It is applicable not only to measurement of concentration, fine particle flow field of polymer material / industrial material process and colloid flow field measurement of food processing process, but also applicable to gas-liquid two-phase flow, micro flow and nano flow fine particle measurement. .

  In addition, the target specimen can be applied not only to fine particles but also to analysis of the behavior of microorganisms such as living bacteria and algae.

  It is explanatory drawing of schematic structure which shows one Example of the dark field type fine particle measuring apparatus of this invention.   It is explanatory drawing which shows one Example of the dark field type fine particle measuring method of this invention.   It is explanatory drawing of one Example of the dark field type fine particle measuring apparatus and dark field type fine particle measuring method of this invention.   It is explanatory drawing of one Example of the dark field type fine particle measuring apparatus and dark field type fine particle measuring method of this invention.   It is a result figure of one Example of the dark field type fine particle measuring apparatus and dark field type fine particle measuring method of this invention.   It is a result figure of one Example of the dark field type fine particle measuring apparatus and dark field type fine particle measuring method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing part 2 Measuring part 3 Light source 4 Collector lens 5 Ring zone optical system 6 Condenser lens 7 Sample body 8 Objective lens 9 Projection optical system 10 CCD sensor 11 Image processing velocimeter 12 Arithmetic circuit 13 Display device

Claims (4)

A light source;
A collector lens that collects the luminous flux from the light source;
An annular optical system that forms a luminous flux from the collector lens into a cylindrical annular light;
A condenser lens that collects the luminous flux from the annular optical system;
A specimen placed at the focal point of the condenser lens;
An objective lens having a focal length longer than the focal length of the condenser lens;
A projection optical system for enlarging an image from the objective lens;
A CCD sensor for receiving an image from the projection lens;
An image processing velocimeter for analyzing the image from the CCD sensor to determine the number of particles and the amount of movement;
An arithmetic circuit for analyzing the signal from the image processing anemometer to obtain the velocity and particle size of the particles;
A dark field fine particle measuring apparatus having an output device for outputting a statistic relating to particle behavior from the image processing velocimeter and the arithmetic circuit. Condensing the luminous flux from the light source with a collector lens;
Forming a luminous flux from the collector lens into a cylindrical annular light by an annular optical system;
A step of condensing the light beam of the annular light on the specimen placed at the focal point of the condenser lens;
Receiving scattered light from the specimen with an objective lens having a focal length longer than the focal length of the condenser lens;
A process of enlarging and projecting an image from the objective lens with a projection optical system;
Receiving an image from the projection optical system with a CCD sensor;
Analyzing the image from the CCD sensor with an image processing velocimeter to determine the number of particles and the amount of movement;
Analyzing the number of particles and the amount of movement from the image processing velocimeter with an arithmetic circuit to determine the velocity and particle size of the particles;
A dark field fine particle measurement method comprising a step of displaying a statistic related to particle behavior on a display device from an image processing velocimeter and an arithmetic circuit. The following Einstein-Stokes relational expression concerning Brownian motion in claim 1 or claim 2, ^**

A dark field fine particle measuring apparatus and a dark field fine particle measuring method, wherein the diameter d of the fine particles is calculated by substituting the amount of movement of the fine particles measured by the image processing velocimeter and the diffusion time. In claim 3,
A process of image analysis by mixing fine particles with a known particle diameter in a fluid with an unknown viscosity coefficient;
A dark field fine particle measuring apparatus and a dark field fine particle measuring method, each of which includes a step of analyzing the Brownian motion of the fine particles and calculating a fluid viscosity coefficient.

Images