WO2023140235A1 - Particle size distribution measurement device, particle size distribution measurement method, and program for particle size distribution measurement - Google Patents

Particle size distribution measurement device, particle size distribution measurement method, and program for particle size distribution measurement Download PDF

Info

Publication number
WO2023140235A1
WO2023140235A1 PCT/JP2023/001117 JP2023001117W WO2023140235A1 WO 2023140235 A1 WO2023140235 A1 WO 2023140235A1 JP 2023001117 W JP2023001117 W JP 2023001117W WO 2023140235 A1 WO2023140235 A1 WO 2023140235A1
Authority
WO
WIPO (PCT)
Prior art keywords
focus position
particle size
size distribution
measurement
focus
Prior art date
Application number
PCT/JP2023/001117
Other languages
French (fr)
Japanese (ja)
Inventor
央昌 菅澤
浩行 越川
浩司 才原
Original Assignee
株式会社堀場製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社堀場製作所 filed Critical 株式会社堀場製作所
Publication of WO2023140235A1 publication Critical patent/WO2023140235A1/en

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N15/02—Investigating particle size or size distribution

Definitions

  • the present invention relates to a particle size distribution measuring device, a particle size distribution measuring method, and a particle size distribution measuring program.
  • PTA method particle trajectory analysis method
  • this measurement method measures the particle size distribution by calculating the diffusion speed due to the Brownian motion of the particles based on the imaging data obtained by imaging the particles in the cell.
  • the inventor tried to apply an existing autofocus function installed in a camera or the like in order to equip the device with a function of automatically adjusting the focus.
  • Some existing autofocus functions focus on the position where the contrast of the image is maximized.
  • the PTA method is characterized by the fact that the number of particles captured in the image is large, the boundaries of the particles are not clear due to scattering phenomena, and the particles are constantly moving due to Brownian motion, and the contrast can change in a short period of time.
  • the present invention solves the above-mentioned problems at once, and the main object thereof is to automatically adjust the focus position in a short time with a high probability of success in particle size distribution measurement by the PTA method.
  • the particle size distribution measuring device is a particle size distribution measuring device comprising: an imaging means for imaging particles in a cell; and an analysis unit for calculating the particle size distribution by calculating diffusion speed due to Brownian motion of particles based on the imaging data obtained by the imaging means.
  • An upper and lower limit focus position determination unit that determines an upper limit focus position that is a focus position where particles start to be imaged, a measurement focus position calculation unit that calculates a measurement focus position that is a focus position between the lower limit focus position and the upper limit focus position and is used during measurement, and an autofocus unit that adjusts the focus of the imaging means to the measurement focus position during measurement.
  • the particle size distribution measuring apparatus configured in this way, the lower limit focus position and the upper limit focus position are determined by moving the focus of the imaging means with respect to the cell, and the measurement focus position is calculated based on these positions. Therefore, the measurement focus position can be calculated in a short time and with a high probability of success compared to the existing autofocus function. Thereby, in the particle size distribution measurement by the PTA method, it becomes possible to automatically adjust the focus position in a short time, and the conventional manual focus adjustment can be saved.
  • a number-related value acquiring unit that acquires a number-related value related to the number of particles from the imaging data is further provided, and the upper and lower limit focus position determining unit determines the lower limit focus position and the upper limit focus position by comparing the number related value acquired by the number related value acquiring unit with a predetermined threshold. According to this configuration, since the lower limit focus position and the upper limit focus position are determined using the number-related value obtained from the imaging data, the operator's subjectivity, for example, does not affect the calculation of the measurement focus position, and reproducibility can be improved.
  • an image processing unit that performs image processing on the imaging data is further provided, and the number-related value acquisition unit acquires the number-related value from the imaging data binarized by the image processing unit.
  • the number-related value acquisition unit acquires the number-related value from the imaging data binarized by the image processing unit. According to this configuration, since the number-related value is acquired using the binarized imaging data, the amount of calculation in the process of acquiring the number-related value is small, and the processing speed can be improved. As a result, it is possible to automatically adjust the focus position in a shorter time.
  • the measurement focus position calculated by the measurement focus position calculation unit falls within a central region of a predetermined length that includes an intermediate point between the lower limit focus position and the upper limit focus position.
  • the measurement accuracy is improved by increasing the number of measurements (that is, by increasing the number of particles to be measured).
  • the focus is not greatly deviated after stirring, and the measurement is continued without changing the focus position before stirring.
  • it is preferable to readjust the focus position after stirring it takes a lot of time and effort to manually adjust the focus every time you stir.
  • the particle size distribution measuring device is configured to further include stirring means for stirring the particles in the cell, the effects of the present invention can be exhibited more remarkably, and the measurement accuracy can be further improved in a short time without much effort.
  • a control section that repeats stirring of the particles in the cell by the stirring means, alignment of the focus of the imaging means by the autofocus section, and measurement of the particle size distribution.
  • a particle size distribution measuring method is a particle size distribution measuring method using a particle size distribution measuring device comprising: an imaging means for imaging particles in a cell; and an analysis unit for calculating the particle size distribution by calculating diffusion speed due to Brownian motion of particles based on imaging data obtained by the imaging means.
  • a method comprising: an upper and lower focus position determining step for determining an upper and lower focus position, which is a focus position where particles start to be captured in the process of moving forward; a measurement focus position calculation step for calculating a focus position for measurement which is a focus position between the lower limit focus position and the upper limit focus position and used during measurement; and an autofocus step for adjusting the focus of the imaging means to the measurement focus position during measurement.
  • a particle size distribution measuring program is a particle size distribution measuring program used in a particle size distribution measuring apparatus comprising: an imaging means for imaging particles in a cell; and an analysis unit for calculating the particle size distribution by calculating diffusion speed due to Brownian motion of particles based on imaging data obtained by the imaging means.
  • a computer execute functions as an upper and lower limit focus position determination unit that determines an upper limit focus position that is a focus position where particles start to be captured in the process of moving from the back side to the front side, a measurement focus position calculation unit that calculates a measurement focus position that is a focus position between them and is used during measurement based on the lower limit focus position and the upper limit focus position, and an autofocus unit that adjusts the focus of the imaging means to the measurement focus position during measurement.
  • FIG. 2 is a functional block diagram showing functions of the information processing apparatus according to the embodiment;
  • FIG. 4 is a schematic diagram for explaining an autofocus function in the same embodiment;
  • 4 is a flow chart showing the operation of the particle size distribution measuring device of the same embodiment.
  • the schematic diagram which shows the particle-size-distribution measuring apparatus in other embodiment. 4 is a flowchart showing the operation of a particle size distribution measuring device according to another embodiment;
  • the particle size distribution measuring apparatus 100 of the present embodiment includes a light irradiation unit 2 that irradiates the particles in the cell 1 with light of an excitation wavelength, an imaging means 3 that images the particles by detecting scattered light from the particles in the cell 1, and an information processing device 4 that analyzes the imaging data obtained by the imaging means 3.
  • the light irradiation unit 2 has a plurality of light sources 21, 22, and 23 that irradiate light with different excitation wavelengths.
  • the light sources 21, 22, 23 are, for example, laser light sources.
  • three light sources 21, 22 and 23 are provided in order to deal with particles of various particle diameters. It should be noted that one light source may irradiate light containing three excitation wavelengths. Also, the number of light sources may be three or more, or may be one.
  • the first light source 21 emits light of a predetermined first excitation wave ⁇ 1
  • the second light source 22 emits light of a predetermined second excitation wavelength ⁇ 2
  • the third light source 23 emits light of a predetermined third excitation wavelength ⁇ 3.
  • Light emitted from these light sources 21 , 22 , 23 is guided to the cell 1 through an irradiation optical system 24 such as reflection mirrors 241 , 242 , half mirrors 243 , 244 , and a condenser lens 245 .
  • These light sources 21, 22, and 23 are controlled by a control unit (not shown) so as to emit light of excitation wavelengths ⁇ 1, ⁇ 2, and ⁇ 3 at the same time. Note that these light sources 21, 22, and 23 can also be controlled to irradiate light at the same time.
  • the imaging means 3 captures an image of the particles by detecting scattered light from the particles in the cell 1.
  • it is an imaging camera such as a CCD camera, and outputs moving image data, for example, as imaging data.
  • the light irradiation direction of the light irradiation unit 2 and the imaging direction of the imaging unit 3 are provided orthogonal to each other, but the invention is not limited to this.
  • the information processing device 4 is a computer equipped with a CPU, memory, display, various input/output devices, etc., and is connected to the imaging means 3 by wire or wirelessly.
  • the information processing device 4 By executing the particle size distribution measurement program stored in the memory, the information processing device 4 exhibits at least the function of the analysis unit 41, as shown in FIG.
  • the analysis unit 41 acquires the imaging data from the imaging means 3 and calculates the particle size distribution by the PTA method based on the imaging data. More specifically, the particle size distribution is calculated by calculating the diffusion speed due to the Brownian motion of the particles based on the imaging data.
  • the particle size distribution measuring apparatus 100 of this embodiment has an autofocus function for automatically focusing the imaging means 3 described above on the particles in the cell 1 .
  • the information processing device 4 described above is configured to exhibit the functions of an autofocus unit 42, an image processing unit 43, a number-related value acquisition unit 44, an upper/lower limit focus position determination unit 45, and a measurement focus position calculation unit 46.
  • the autofocus unit 42 moves the focus of the imaging means 3 according to a predetermined rule, and is specifically configured to move the focus of the imaging means 3 forward and backward with respect to the cell 1 .
  • the autofocus unit 42 moves the focus of the imaging means 3 from the front side to the back side of the cell 1 or from the back side to the front side of the cell 1, as shown in FIG. 3(a).
  • the autofocus unit 42 here moves the focus of the imaging means 3 from the front side end face A of the cell 1 or further from the front side to the back side of the end face A, or from the back side end face B of the cell 1 or further from the back side of the end face B to the front side.
  • the autofocus part 42 may be moved from the front side to the back side of the front side end face A of the cell 1, or moved from the front side to the front side of the back side end face B of the cell 1 to the front side.
  • the autofocus unit 42 of the present embodiment moves the focus of the imaging means 3 by a predetermined distance with respect to the cell 1, and is configured such that the imaging means 3 images the inside of the cell 1 at each focus position of the movement destination, and the imaging data is sent to the image processing unit 43.
  • the image processing unit 43 performs image processing on the imaging data transmitted by the imaging means 3. Specifically, it performs image processing on the imaging data so that particles appearing in the image indicated by the imaging data can be distinguished from particles other than particles appearing in the same image.
  • the image processing unit 43 of the present embodiment is configured to binarize each of the imaging data sequentially sent from the imaging means 3, so that in the image indicated by the imaging data, for example, particles appear white and other particles appear black.
  • the number-related value acquisition unit 44 acquires a number-related value related to the number of particles included in the image indicated by the imaging data.
  • the number-related value is a concept including not only a value related to the number of particles but also a value indicating the number of particles itself.
  • the number-related value acquisition unit 44 of the present embodiment acquires the number-related value from the image data processed by the image processing unit 43, and here acquires the number-related value from the binarized image data.
  • the number-related value acquiring unit 44 here is configured to acquire the number-related value using pixels (white pixels) representing particles among the large number of pixels that make up the binarized image data.
  • pixels (white pixels) representing particles are counted, and the counted number of pixels or a value obtained from the number of pixels (for example, the ratio of the number of pixels to the total number of pixels) is acquired as the number-related value.
  • the number-related value acquisition unit 44 when pixels representing particles (white pixels) are gathered in a predetermined number of pixels or more, the collection of those pixels may be counted as one particle, and the counted number of particles may be acquired as the number-related value.
  • the number-related value acquired in this manner is output from the number-related value acquisition unit 44 to the upper/lower limit focus position determination unit 45 .
  • the upper/lower limit focus position determination unit 45 determines the lower limit focus position, which is the focus position where particles start to be captured in the process in which the autofocus unit 42 moves the focus of the imaging means 3 from the front side to the back side of the cell 1, and the upper limit focus position, which is the focus position in which the particles start to be captured in the process in which the autofocus unit 42 moves the focus of the imaging means 3 from the back side to the front side of the cell 1. It should be noted that the focus position where the particle starts to appear here is the focus position where the particle disappears when the direction of movement of the focus is reversed.
  • the lower limit focus position and upper limit focus position determined by the upper and lower limit focus position determination unit 45 do not necessarily have to be the focus position at the moment when the particle starts to be photographed, and may be a focus position slightly displaced after the particle starts to be photographed.
  • lower limit focus position and upper limit focus position are positions used for calculation of the measurement focus position used in the measurement described later, and are positions that serve as a reference for the measurement focus position, so to speak.
  • the upper/lower limit focus position determination unit 45 of the present embodiment determines the lower limit focus position and the upper limit focus position by comparing the number-related value acquired by the number-related value acquisition unit 44 described above with a predetermined threshold value. Note that the threshold used to determine the lower limit focus position and the threshold used to determine the upper limit focus position may be the same value or different values.
  • the images shown by these imaging data do not show particles for a while after the focus is moved (X in Fig. 3), but at a certain timing (Y in Fig. 3), particles start to appear, and after that the number of particles should increase.
  • the number-related value does not change for a while after the focus is moved, and the number-related value should change at a certain timing. This is common to the case of moving the focus from the front side to the back side of the cell 1 and the case of moving the focus from the back side to the front side of the cell 1 .
  • the upper/lower limit focus position determination unit 45 sequentially compares the number-related value obtained from each piece of imaging data with a predetermined threshold, and when the number-related value exceeds the threshold, determines the focus position corresponding to the imaging data from which the number-related value was obtained as the lower limit focus position or the upper limit focus position.
  • the lower limit focus position and the upper limit focus position determined in this manner are output from the upper and lower limit focus position determination section 45 to the measurement focus position calculation section 46 .
  • the measurement focus position calculation unit 46 calculates, based on the lower limit focus position and the upper limit focus position, a measurement focus position that is a focus position between them and is used during measurement.
  • the measurement focus position calculator 46 is configured to calculate the measurement focus position using, for example, a predetermined calculation formula or the like, and is configured so that the calculated measurement focus position falls within an intermediate region of a predetermined length including the intermediate point between the lower limit focus position and the upper limit focus position.
  • the length occupied by the intermediate region is preferably half or less, more preferably 1 ⁇ 3 or less, of the length from the lower limit focus position to the upper limit focus position.
  • the measurement focus position calculator 46 of the present embodiment calculates the intermediate point between the lower limit focus position and the upper limit focus position as the measurement focus position.
  • the measurement focus position calculation unit 46 may, for example, weight the lower limit focus position or the upper limit focus position, and calculate a position shifted from the middle point of these positions as the measurement focus position.
  • the measurement focus position calculated by the measurement focus position calculation unit 46 is output to the autofocus unit 42 described above, and the autofocus unit 42 focuses the imaging means 3 to the measurement focus position before measuring the particle size distribution.
  • the autofocus unit 42 moves the focus of the imaging means 3 back and forth with respect to the cell 1 .
  • the autofocus unit 42 of the present embodiment first moves the focus of the imaging means 3 from the front side of the cell 1 to the back side, for example, by a predetermined distance (S1).
  • the imaging data obtained at the destination is sent from the imaging means 3 to the image processing section 43, and the image processing section 43 binarizes the imaging data (S2).
  • the number-related value acquisition unit 44 acquires the number-related value from the binarized imaging data, for example, by counting the number of pixels representing particles (S3).
  • the upper/lower limit focus position determining unit 45 compares each number-related value acquired by the number-related value acquiring unit 44 with a threshold value (S4).
  • the upper/lower limit focus position determination unit 45 determines the focus position corresponding to the imaging data from which the number-related value was acquired as the lower limit focus position (S5).
  • the autofocus unit 42 moves the focus of the imaging means 3 from the back side of the cell 1 to the front side, for example, by a predetermined distance (S6).
  • the imaging data obtained at the destination is sent from the imaging means 3 to the image processing section 43, and the image processing section 43 binarizes the imaging data (S7).
  • the number-related value acquisition unit 44 acquires the number-related value from the binarized imaging data, for example, by counting the number of pixels representing particles (S8). Note that processing such as object recognition may be performed in order to adjust the focus position with higher accuracy.
  • the upper/lower limit focus position determining unit 45 compares each number-related value acquired by the number-related value acquiring unit 44 with a threshold value (S9).
  • the upper/lower limit focus position determining unit 45 determines the focus position corresponding to the imaging data from which the number-related value was acquired as the upper limit focus position (S10).
  • the lower limit focus position and the upper limit focus position determined by the upper and lower limit focus position determination unit 45 are sent to the measurement focus position calculation unit 46, and the measurement focus position calculation unit 46 calculates the middle point between the lower limit focus position and the upper limit focus position as the measurement focus position (S11).
  • this measurement focus position is output to the autofocus section 42 again, and the autofocus section 42 moves the focus of the imaging means 3 to the measurement focus position (S12).
  • Accurate measurement can be performed by activating the above-described autofocus function to focus the imaging means 3 on the focus position for measurement and measuring the particle size distribution in this state (S13).
  • the lower limit focus position and the upper limit focus position are determined by moving the focus of the imaging means 3 with respect to the cell, and the measurement focus position is calculated based on these positions. Therefore, the measurement focus position can be calculated in a short time and with a high probability of success compared to the existing autofocus function. Thereby, in the particle size distribution measurement by the PTA method, it becomes possible to automatically adjust the focus position in a short time, and the conventional manual focus adjustment can be saved.
  • the number-related value acquiring unit 44 acquires the number-related value using the binarized imaging data, the amount of calculation for acquiring the number-related value can be reduced, the processing speed can be improved, and as a result, the focus position can be automatically adjusted in a short time.
  • the information processing apparatus 40 of the present embodiment automatically determines the upper limit focus position and the lower limit focus position, calculates the focus position for measurement, and adjusts the focus to the focus position for measurement.
  • the particle size distribution measuring apparatus 100 may further include stirring means 5 for stirring the particles in the cell 1, as shown in FIG.
  • the information processing device 4 may include a control unit that repeats the position adjustment (T1) of the focus of the imaging means 3 by the autofocus function, the calculation (T2) of the particle size distribution by the analysis unit 41, and the stirring (T3) of the particles in the cell 1 by the stirring means 7, respectively.
  • the number-related value acquisition unit 44 acquires the number-related value based on the binarized image data in this embodiment, it may acquire the number-related value based on the image data after image processing different from binarization.
  • the number-related value acquisition unit 44 may acquire the number-related value based on the imaging data that has not undergone image processing. In this case, the function of the image processing unit 43 can be omitted from the information processing device 4 .
  • the information processing device 4 does not necessarily need to include the upper/lower limit focus position determination unit 45 .
  • the measurement focus position calculation unit 46 calculates the measurement focus position using the input lower limit focus position and upper limit focus position.
  • the upper and lower limit focus position determination unit 45 determines the upper limit focus position after determining the lower limit focus position in the above embodiment, but may be configured to determine the lower limit focus position after determining the upper limit focus position.
  • the focus of the imaging means 3 is moved by a predetermined distance with respect to the cell 1 to determine the lower limit focus position and the upper limit focus position.
  • the focus of the imaging means 3 may be continuously moved with respect to the cell 1, and the lower limit focus position and the upper limit focus position may be determined based on the imaging data captured by the imaging means 3 in the process.
  • the particle size distribution measuring apparatus 100 may be provided with a display section for displaying the actual focus position of the imaging means 3 using, for example, numerical values.
  • this display unit may display the focus position in real time while the focus is being moved.
  • the display unit may be configured to display an image indicated by the imaging data obtained by the imaging means 3 on a display or the like while the focus is being moved and/or after the autofocus operation is completed.
  • the particle size distribution measuring device 100 may be configured so that the focus of the imaging means 3 can be manually changed so that the focus position can be finely adjusted, for example, after the autofocus operation is completed.
  • a focus position change button may be displayed on a display or the like, and by operating this button, the focus of the imaging means 3 can be manually changed.
  • the focus position can be automatically adjusted in a short time in the particle size distribution measurement by the PTA method.
  • Particle size distribution measuring device 1 Cell 2 Light irradiation unit 3 Imaging means 4 Information processing device 41 Analysis unit 42 Autofocus unit 43 Image processing unit 44 Number-related value acquisition unit 45 Upper and lower limit focus position determination unit 46 Focus position calculation unit for measurement

Landscapes

  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Length Measuring Devices By Optical Means (AREA)

Abstract

In order to make it possible to automatically adjust a focus position in a short time in particle size distribution measurement by a PTA method, there is provided a particle size distribution measurement device 100 comprising an imaging means 3 for capturing an image of particles in a cell 1, and an analysis unit 41 for calculating a particle size distribution by calculating the diffusion velocity due to Brownian motion of the particles on the basis of imaging data obtained by the imaging means, the particle size distribution measurement device 100 further comprising: an upper/lower-limit focus position determination unit 45 for determining a lower-limit focus position which is the focus position at which particles begin to appear as the focus of the imaging means 2 is moved from the front to the back side of the cell 1, and an upper-limit focus position which is the focus position at which particles begin to appear as the focus of the imaging means 3 is moved from the back to the front side of the cell 1; a measurement focus position calculation unit 46 for calculating a measurement focus position which is used during measurement and is between the lower-limit focus position and the upper-limit focus position, on the basis of the lower-limit focus position and the upper-limit focus position; and an autofocus unit 42 for adjusting the focus of the imaging means to the measurement focus position during measurement.

Description

粒子径分布測定装置、粒子径分布測定方法、及び粒子径分布測定用プログラムParticle size distribution measuring device, particle size distribution measuring method, and particle size distribution measuring program
　本発明は、粒子径分布測定装置、粒子径分布測定方法、及び粒子径分布測定用プログラムに関するものである。 The present invention relates to a particle size distribution measuring device, a particle size distribution measuring method, and a particle size distribution measuring program.
　従来の粒子径分布測定装置としては、粒子軌跡解析法（ＰＴＡ法）と称される測定法を用いたものがある。 As a conventional particle size distribution measurement device, there is one that uses a measurement method called particle trajectory analysis method (PTA method).
　具体的にこの測定法は、セル内の粒子を撮像して得られる撮像データに基づいて、粒子のブラウン運動による拡散速度を算出することで粒子径分布を測定するものである。 Specifically, this measurement method measures the particle size distribution by calculating the diffusion speed due to the Brownian motion of the particles based on the imaging data obtained by imaging the particles in the cell.
　かかる粒子径分布測定装置において、測定精度を担保するためには多くの粒子にフォーカスを合わせた状態で撮像データを得ることが望ましいものの、現状では、作業者が手動でフォーカス位置を調整しており、この作業には手間や時間がかかっている。 With such a particle size distribution measuring device, it is desirable to obtain imaging data with many particles in focus in order to ensure measurement accuracy. However, at present, operators manually adjust the focus position, which takes time and effort.
　そこで本発明者は、装置にフォーカスを自動で合わせる機能を備えさせるべく、カメラ等に搭載されている既存のオートフォーカス機能の適用を試みた。 Therefore, the inventor tried to apply an existing autofocus function installed in a camera or the like in order to equip the device with a function of automatically adjusting the focus.
　かかる既存のオートフォーカス機能としては、画像のコントラストが最大となる位置にフォーカスを合わせるものがある。 Some existing autofocus functions focus on the position where the contrast of the image is maximized.
　ところが、ＰＴＡ法は、画像に写る粒子数が多い、粒子の境界が散乱現象によって明確でない、粒子がブラウン運動により常に動いており短時間でコントラストが変化し得るといった特徴があることから、上述した既存のオートフォーカス機能を用いても、コントラストを最大化する動作が収束しない場合が多い。 However, the PTA method is characterized by the fact that the number of particles captured in the image is large, the boundaries of the particles are not clear due to scattering phenomena, and the particles are constantly moving due to Brownian motion, and the contrast can change in a short period of time.
　その結果、ＰＴＡ法に既存のフォーカス機能を適用してもフォーカス位置が定まらないことが多く、現実的には時間の短縮化につながらない。 As a result, even if the existing focus function is applied to the PTA method, the focus position is often not fixed, and in reality it does not lead to a reduction in time.
特開２０２０―２０４６０４JP 2020-204604
　そこで、本発明は上述した問題を一挙に解決するものであり、ＰＴＡ法による粒子径分布測定において、フォーカス位置を短時間で且つ高い成功確率で自動的に合わせることができるようにすることをその主たる課題とするものである。 Therefore, the present invention solves the above-mentioned problems at once, and the main object thereof is to automatically adjust the focus position in a short time with a high probability of success in particle size distribution measurement by the PTA method.
　すなわち本発明に係る粒子径分布測定装置は、セル内の粒子を撮像する撮像手段と、前記撮像手段により得られる撮像データに基づいて、粒子のブラウン運動による拡散速度を算出することにより粒子径分布を算出する分析部と、を備える粒子径分布測定装置であって、前記撮像手段のフォーカスを前記セルの手前側から奥側に移動させる過程で粒子が写り始めるフォーカス位置である下限フォーカス位置と、前記撮像手段のフォーカスを前記セルの奥側から手前側に移動させる過程で粒子が写り始めるフォーカス位置である上限フォーカス位置とを決定する上下限フォーカス位置決定部と、前記下限フォーカス位置及び前記上限フォーカス位置に基づいて、これらの間のフォーカス位置であって測定時に用いる測定用フォーカス位置を算出する測定用フォーカス位置算出部と、前記撮像手段のフォーカスを、測定時に前記測定用フォーカス位置に合わせるオートフォーカス部と、を備えることを特徴とするものである。 That is, the particle size distribution measuring device according to the present invention is a particle size distribution measuring device comprising: an imaging means for imaging particles in a cell; and an analysis unit for calculating the particle size distribution by calculating diffusion speed due to Brownian motion of particles based on the imaging data obtained by the imaging means. An upper and lower limit focus position determination unit that determines an upper limit focus position that is a focus position where particles start to be imaged, a measurement focus position calculation unit that calculates a measurement focus position that is a focus position between the lower limit focus position and the upper limit focus position and is used during measurement, and an autofocus unit that adjusts the focus of the imaging means to the measurement focus position during measurement.
　このように構成された粒子径分布測定装置によれば、撮像手段のフォーカスをセルに対して移動させることにより、下限フォーカス位置及び上限フォーカス位置が決定されて、これらの位置に基づいて測定用フォーカス位置が算出されるので、既存のオートフォーカス機能と比べて短時間で且つ高い成功確率で測定用フォーカス位置を算出することができる。
　これにより、ＰＴＡ法による粒子径分布測定において、フォーカス位置を短時間で自動的に合わせることが可能となり、従来の手動によるフォーカス調整の手間を省くことができる。 According to the particle size distribution measuring apparatus configured in this way, the lower limit focus position and the upper limit focus position are determined by moving the focus of the imaging means with respect to the cell, and the measurement focus position is calculated based on these positions. Therefore, the measurement focus position can be calculated in a short time and with a high probability of success compared to the existing autofocus function.
Thereby, in the particle size distribution measurement by the PTA method, it becomes possible to automatically adjust the focus position in a short time, and the conventional manual focus adjustment can be saved.
　前記撮像データから粒子の個数に関する個数関連値を取得する個数関連値取得部をさらに備え、前記上下限フォーカス位置決定部が、前記個数関連値取得部により取得された前記個数関連値と所定の閾値とを比較することで、前記下限フォーカス位置及び前記上限フォーカス位置を決定することが望ましい。
　この構成によれば、撮像データから取得される個数関連値を用いて下限フォーカス位置及び上限フォーカス位置が決定されるので、測定用フォーカス位置の算出に例えば作業者の主観が影響せず、再現性の向上等を図れる。 It is preferable that a number-related value acquiring unit that acquires a number-related value related to the number of particles from the imaging data is further provided, and the upper and lower limit focus position determining unit determines the lower limit focus position and the upper limit focus position by comparing the number related value acquired by the number related value acquiring unit with a predetermined threshold.
According to this configuration, since the lower limit focus position and the upper limit focus position are determined using the number-related value obtained from the imaging data, the operator's subjectivity, for example, does not affect the calculation of the measurement focus position, and reproducibility can be improved.
　前記撮像データを画像処理する画像処理部をさらに備え、前記個数関連値取得部が、前記画像処理部により二値化された前記撮像データから前記個数関連値を取得することが望ましい。
　この構成によれば、二値化された撮像データを用いて個数関連値を取得するので、個数関連値を取得する過程での計算量が少なく、処理速度の向上を図ることができ、その結果、より短時間でフォーカス位置を自動的に合わせることが可能となる。 It is preferable that an image processing unit that performs image processing on the imaging data is further provided, and the number-related value acquisition unit acquires the number-related value from the imaging data binarized by the image processing unit.
According to this configuration, since the number-related value is acquired using the binarized imaging data, the amount of calculation in the process of acquiring the number-related value is small, and the processing speed can be improved. As a result, it is possible to automatically adjust the focus position in a shorter time.
　測定精度を担保できる程度に多数の粒子を撮像できるようにするためには、前記測定用フォーカス位置算出部により算出された前記測定用フォーカス位置が、前記下限フォーカス位置と前記上限フォーカス位置との中間点を含む所定の長さの中央領域内に収まっていることが望ましい。 In order to be able to image a large number of particles to the extent that the measurement accuracy can be ensured, it is desirable that the measurement focus position calculated by the measurement focus position calculation unit falls within a central region of a predetermined length that includes an intermediate point between the lower limit focus position and the upper limit focus position.
　ところで、ＰＴＡ法による測定では、粒子径分布の測定後、セル内の粒子を攪拌したり、或いは、撮像する位置を変更したりして、再び粒子径分布を測定するといった作業を繰り返すことで、測定回数を増やして（すなわち、測定対象粒子数を増やして）、測定精度の向上を図る場合がある。
　この場合、現状では、撹拌後はフォーカスが大きく外れていないと考え、撹拌前のフォーカス位置を変えずに測定を続けているが、測定精度のさらなる向上を図るには、撹拌後もフォーカス位置を再調整することが好ましい。
　とはいえ、撹拌する度にフォーカスを手動で合わせるのでは、時間や手間が膨大にかかってしまう。 By the way, in the measurement by the PTA method, after the measurement of the particle size distribution, the particles in the cell are stirred, or the imaging position is changed, and the particle size distribution is measured again. In some cases, the measurement accuracy is improved by increasing the number of measurements (that is, by increasing the number of particles to be measured).
In this case, currently, it is considered that the focus is not greatly deviated after stirring, and the measurement is continued without changing the focus position before stirring. However, in order to further improve the measurement accuracy, it is preferable to readjust the focus position after stirring.
However, it takes a lot of time and effort to manually adjust the focus every time you stir.
　そこで、前記粒子径分布測定装置が、前記セル内の粒子を攪拌させる攪拌手段をさらに備える構成であれば、本発明の作用効果がより顕著に発揮され、短時間で手間をかけずに測定精度のさらなる向上を図れる。 Therefore, if the particle size distribution measuring device is configured to further include stirring means for stirring the particles in the cell, the effects of the present invention can be exhibited more remarkably, and the measurement accuracy can be further improved in a short time without much effort.
　上述した撹拌手段を備える構成において、測定の自動化を図るためには、前記撹拌手段による前記セル内の粒子の撹拌と、前記オートフォーカス部による前記撮像手段のフォーカスの位置合わせと、前記粒子径分布の測定とを繰り返す制御部を備えていることが好ましい。 In the configuration including the stirring means described above, in order to automate the measurement, it is preferable to include a control section that repeats stirring of the particles in the cell by the stirring means, alignment of the focus of the imaging means by the autofocus section, and measurement of the particle size distribution.
　本発明に係る粒子径分布測定方法は、セル内の粒子を撮像する撮像手段と、前記撮像手段により得られる撮像データに基づいて、粒子のブラウン運動による拡散速度を算出することにより粒子径分布を算出する分析部と、を備える粒子径分布測定装置を用いた粒子径分布測定方法であって、前記撮像手段のフォーカスを前記セルの手前側から奥側に移動させる過程で粒子が写り始めるフォーカス位置である下限フォーカス位置と、前記撮像手段のフォーカスを前記セルの奥側から手前側に移動させる過程で粒子が写り始めるフォーカス位置である上限フォーカス位置とを決定する上下限フォーカス位置決定ステップと、前記下限フォーカス位置及び前記上限フォーカス位置に基づいて、これらの間のフォーカス位置であって測定時に用いる測定用フォーカス位置を算出する測定用フォーカス位置算出ステップと、前記撮像手段のフォーカスを、測定時に前記測定用フォーカス位置に合わせるオートフォーカスステップと、を備えることを特徴とする方法である。 A particle size distribution measuring method according to the present invention is a particle size distribution measuring method using a particle size distribution measuring device comprising: an imaging means for imaging particles in a cell; and an analysis unit for calculating the particle size distribution by calculating diffusion speed due to Brownian motion of particles based on imaging data obtained by the imaging means. A method comprising: an upper and lower focus position determining step for determining an upper and lower focus position, which is a focus position where particles start to be captured in the process of moving forward; a measurement focus position calculation step for calculating a focus position for measurement which is a focus position between the lower limit focus position and the upper limit focus position and used during measurement; and an autofocus step for adjusting the focus of the imaging means to the measurement focus position during measurement.
　また、本発明に係る粒子径分布測定用プログラムは、セル内の粒子を撮像する撮像手段と、前記撮像手段により得られる撮像データに基づいて、粒子のブラウン運動による拡散速度を算出することにより粒子径分布を算出する分析部と、を備える粒子径分布測定装置に用いられる粒子径分布測定用プログラムであって、前記撮像手段のフォーカスを前記セルの手前側から奥側に移動させる過程で粒子が写り始めるフォーカス位置である下限フォーカス位置と、前記撮像手段のフォーカスを前記セルの奥側から手前側に移動させる過程で粒子が写り始めるフォーカス位置である上限フォーカス位置とを決定する上下限フォーカス位置決定部と、前記下限フォーカス位置及び前記上限フォーカス位置に基づいて、これらの間のフォーカス位置であって測定時に用いる測定用フォーカス位置を算出する測定用フォーカス位置算出部と、前記撮像手段のフォーカスを、測定時に前記測定用フォーカス位置に合わせるオートフォーカス部としての機能をコンピュータに実行させることを特徴とするものである。 Further, a particle size distribution measuring program according to the present invention is a particle size distribution measuring program used in a particle size distribution measuring apparatus comprising: an imaging means for imaging particles in a cell; and an analysis unit for calculating the particle size distribution by calculating diffusion speed due to Brownian motion of particles based on imaging data obtained by the imaging means. It is characterized by causing a computer to execute functions as an upper and lower limit focus position determination unit that determines an upper limit focus position that is a focus position where particles start to be captured in the process of moving from the back side to the front side, a measurement focus position calculation unit that calculates a measurement focus position that is a focus position between them and is used during measurement based on the lower limit focus position and the upper limit focus position, and an autofocus unit that adjusts the focus of the imaging means to the measurement focus position during measurement.
　このような粒子径分布測定方法及び粒子径分布測定用プログラムであれば、上述した粒子径分布測定装置と同様の作用効果が得られる。 With such a particle size distribution measuring method and particle size distribution measuring program, the same effects as those of the particle size distribution measuring apparatus described above can be obtained.
　以上に述べた本発明によれば、ＰＴＡ法による粒子径分布測定において、フォーカス位置を短時間で自動的に合わせることが可能となり、従来の手動によるフォーカス調整の手間を省くことができる。 According to the present invention described above, in the particle size distribution measurement by the PTA method, it is possible to automatically adjust the focus position in a short time, and the conventional manual focus adjustment can be saved.
本発明の一実施形態に係る粒子径分布測定装置を示す模式図。BRIEF DESCRIPTION OF THE DRAWINGS The schematic diagram which shows the particle size distribution measuring apparatus which concerns on one Embodiment of this invention. 同実施形態の情報処理装置の機能を示す機能ブロック図。FIG. 2 is a functional block diagram showing functions of the information processing apparatus according to the embodiment; 同実施形態におけるオートフォーカス機能を説明するための模式図。FIG. 4 is a schematic diagram for explaining an autofocus function in the same embodiment; 同実施形態の粒子径分布測定装置の動作を示すフローチャート。4 is a flow chart showing the operation of the particle size distribution measuring device of the same embodiment. その他の実施形態における粒子径分布測定装置を示す模式図。The schematic diagram which shows the particle-size-distribution measuring apparatus in other embodiment. その他の実施形態における粒子径分布測定装置の動作を示すフローチャート。4 is a flowchart showing the operation of a particle size distribution measuring device according to another embodiment;
　以下、本発明に係る粒子径分布測定装置の一実施形態について、図面を参照しながら説明する。 An embodiment of the particle size distribution measuring device according to the present invention will be described below with reference to the drawings.
＜装置構成＞
　本実施形態における粒子径分布測定装置１００は、図１に示すように、セル１内の粒子に励起波長の光を照射する光照射部２と、セル１内の粒子による散乱光を検出することで粒子を撮像する撮像手段３と、撮像手段３により得られた撮像データを解析する情報処理装置４とを備える。 <Device configuration>
As shown in FIG. 1, the particle size distribution measuring apparatus 100 of the present embodiment includes a light irradiation unit 2 that irradiates the particles in the cell 1 with light of an excitation wavelength, an imaging means 3 that images the particles by detecting scattered light from the particles in the cell 1, and an information processing device 4 that analyzes the imaging data obtained by the imaging means 3.
　光照射部２は、異なる励起波長の光を照射する複数の光源２１、２２、２３を有している。光源２１、２２、２３は、例えばレーザー光源である。ここで、粒子による散乱光を検出して粒子を撮像する場合、粒子径に応じて適した励起波長の光を照射する必要がある。本実施形態では、様々な粒子径の粒子対応するために、３つの光源２１、２２、２３を有している。なお、１つの光源において３つの励起波長を含む光を照射するものであっても良い。また、光源の数は３つ以上であっても良いし、１つであっても良い。 The light irradiation unit 2 has a plurality of light sources 21, 22, and 23 that irradiate light with different excitation wavelengths. The light sources 21, 22, 23 are, for example, laser light sources. Here, when capturing an image of a particle by detecting light scattered by the particle, it is necessary to irradiate light with an excitation wavelength suitable for the particle diameter. In this embodiment, three light sources 21, 22 and 23 are provided in order to deal with particles of various particle diameters. It should be noted that one light source may irradiate light containing three excitation wavelengths. Also, the number of light sources may be three or more, or may be one.
　第１の光源２１は、所定の第１の励起波λ１の光を照射するものであり、第２の光源２２は、所定の第２の励起波長λ２の光を照射するものであり、第３の光源２３は、所定の第３の励起波長λ３の光を照射するものである。また、これら各光源２１、２２、２３から射出された光は、反射ミラー２４１、２４２、ハーフミラー２４３、２４４、集光レンズ２４５等の照射光学系２４を介して、セル１に導光される。 The first light source 21 emits light of a predetermined first excitation wave λ1, the second light source 22 emits light of a predetermined second excitation wavelength λ2, and the third light source 23 emits light of a predetermined third excitation wavelength λ3. Light emitted from these light sources 21 , 22 , 23 is guided to the cell 1 through an irradiation optical system 24 such as reflection mirrors 241 , 242 , half mirrors 243 , 244 , and a condenser lens 245 .
　これらの光源２１、２２、２３は、図示しない制御部によって、各励起波長λ１、λ２、λ３の光を同時に照射するように制御されている。なお、これらの光源２１、２２、２３は、同時に光を照射するように制御することもできる。 These light sources 21, 22, and 23 are controlled by a control unit (not shown) so as to emit light of excitation wavelengths λ1, λ2, and λ3 at the same time. Note that these light sources 21, 22, and 23 can also be controlled to irradiate light at the same time.
　撮像手段３は、セル１内の粒子による散乱光を検出することで粒子を撮像するものであり、本実施形態では、例えばＣＣＤカメラ等の撮像カメラであり、撮像データとして例えば動画像データを出力する。なお、図１では、光照射部２の光照射方向と撮像手段３の撮像方向とが互いに直交して設けられているが、これに限られない。 The imaging means 3 captures an image of the particles by detecting scattered light from the particles in the cell 1. In this embodiment, it is an imaging camera such as a CCD camera, and outputs moving image data, for example, as imaging data. In addition, in FIG. 1, the light irradiation direction of the light irradiation unit 2 and the imaging direction of the imaging unit 3 are provided orthogonal to each other, but the invention is not limited to this.
　情報処理装置４は、ＣＰＵ、メモリ、ディスプレイ、各種入出力機器等を備えたコンピュータであり、撮像手段３と有線又は無線でつながれている。 The information processing device 4 is a computer equipped with a CPU, memory, display, various input/output devices, etc., and is connected to the imaging means 3 by wire or wirelessly.
　この情報処理装置４は、前記メモリに格納されている粒子径分布測定用プログラムが実行されることにより、図２に示すように、少なくとも分析部４１としての機能を発揮する。 By executing the particle size distribution measurement program stored in the memory, the information processing device 4 exhibits at least the function of the analysis unit 41, as shown in FIG.
　分析部４１は、撮像手段３から撮像データを取得するとともに、この撮像データに基づいてＰＴＡ法により粒子径分布を算出するものであり、より具体的には、撮像データに基づいて、粒子のブラウン運動による拡散速度を算出することにより粒子径分布を算出する。 The analysis unit 41 acquires the imaging data from the imaging means 3 and calculates the particle size distribution by the PTA method based on the imaging data. More specifically, the particle size distribution is calculated by calculating the diffusion speed due to the Brownian motion of the particles based on the imaging data.
　然して、本実施形態の粒子径分布測定装置１００は、上述した撮像手段３のフォーカスをセル１内の粒子に自動で合わせるオートフォーカス機能を備えてなる。 Therefore, the particle size distribution measuring apparatus 100 of this embodiment has an autofocus function for automatically focusing the imaging means 3 described above on the particles in the cell 1 .
　具体的には、上述した情報処理装置４が、図２に示すように、オートフォーカス部４２、画像処理部４３、個数関連値取得部４４、上下限フォーカス位置決定部４５、及び測定用フォーカス位置算出部４６としての機能を発揮するように構成されている。 Specifically, as shown in FIG. 2, the information processing device 4 described above is configured to exhibit the functions of an autofocus unit 42, an image processing unit 43, a number-related value acquisition unit 44, an upper/lower limit focus position determination unit 45, and a measurement focus position calculation unit 46.
　オートフォーカス部４２は、撮像手段３のフォーカスを所定の規則に従って移動させるものであり、具体的には撮像手段３のフォーカスをセル１に対して進退移動させるように構成されている。 The autofocus unit 42 moves the focus of the imaging means 3 according to a predetermined rule, and is specifically configured to move the focus of the imaging means 3 forward and backward with respect to the cell 1 .
　このオートフォーカス部４２は、図３（ａ）に示すように、撮像手段３のフォーカスをセル１の手前側から奥側に、又は、セル１の奥側から手前側に移動させるものである。 The autofocus unit 42 moves the focus of the imaging means 3 from the front side to the back side of the cell 1 or from the back side to the front side of the cell 1, as shown in FIG. 3(a).
　より具体的に説明すると、ここでのオートフォーカス部４２は、撮像手段３のフォーカスを、セル１の手前側端面Ａから或いは同端面Ａよりもさらに手前側から奥側に移動させる、又は、セル１の奥側端面Ｂから或いは同端面Ｂよりもさらに奥側から手前側に移動させる。
　ただし、オートフォーカス部４２としては、セル１の手前側端面Ａよりもやや奥側からさらに奥側に移動させる、又は、セル１の奥側端面Ｂよりもやや手前側からさらに手前側に移動させるものであっても良い。 More specifically, the autofocus unit 42 here moves the focus of the imaging means 3 from the front side end face A of the cell 1 or further from the front side to the back side of the end face A, or from the back side end face B of the cell 1 or further from the back side of the end face B to the front side.
However, the autofocus part 42 may be moved from the front side to the back side of the front side end face A of the cell 1, or moved from the front side to the front side of the back side end face B of the cell 1 to the front side.
　本実施形態のオートフォーカス部４２は、撮像手段３のフォーカスをセル１に対して所定距離ずつ移動させるものであり、その移動先のフォーカス位置それぞれにおいて撮像手段３がセル１内を撮像し、その撮像データが画像処理部４３に送られるように構成されている。 The autofocus unit 42 of the present embodiment moves the focus of the imaging means 3 by a predetermined distance with respect to the cell 1, and is configured such that the imaging means 3 images the inside of the cell 1 at each focus position of the movement destination, and the imaging data is sent to the image processing unit 43.
　画像処理部４３は、撮像手段３により送信された撮像データを画像処理するものであり、具体的には、撮像データの示す画像に写されている粒子と、同画像に写されている粒子以外とが識別可能となるように、撮像データを画像処理するものである。 The image processing unit 43 performs image processing on the imaging data transmitted by the imaging means 3. Specifically, it performs image processing on the imaging data so that particles appearing in the image indicated by the imaging data can be distinguished from particles other than particles appearing in the same image.
　本実施形態の画像処理部４３は、撮像手段３から逐次送られてくる撮像データそれぞれを二値化するように構成されており、これにより撮像データの示す画像には、例えば粒子が白色に写り、それ以外は黒色に写る。 The image processing unit 43 of the present embodiment is configured to binarize each of the imaging data sequentially sent from the imaging means 3, so that in the image indicated by the imaging data, for example, particles appear white and other particles appear black.
　個数関連値取得部４４は、撮像データの示す画像に含まれる粒子の個数に関連する個数関連値を取得するものである。なお、個数関連値とは、粒子の個数に関連する値のみならず、粒子の個数そのものを示す値をも含む概念である。 The number-related value acquisition unit 44 acquires a number-related value related to the number of particles included in the image indicated by the imaging data. The number-related value is a concept including not only a value related to the number of particles but also a value indicating the number of particles itself.
　本実施形態の個数関連値取得部４４は、画像処理部４３による処理後の画像データから個数関連値を取得するものであり、ここでは二値化された画像データから個数関連値を取得する。 The number-related value acquisition unit 44 of the present embodiment acquires the number-related value from the image data processed by the image processing unit 43, and here acquires the number-related value from the binarized image data.
　より詳細に説明すると、ここでの個数関連値取得部４４は、二値化された画像データを構成する多数の画素のうち、粒子を表す画素（白色の画素）を用いて個数関連値を取得するように構成されている。 More specifically, the number-related value acquiring unit 44 here is configured to acquire the number-related value using pixels (white pixels) representing particles among the large number of pixels that make up the binarized image data.
　個数関連値取得部４４の具体的な一実施態様としては、粒子を表す画素（白色の画素）をカウントして、そのカウントした画素数、又は、その画素数から得られる値（例えば、その画素数の全画素数に対する比率など）を個数関連値として取得する態様を挙げることができる。 As a specific embodiment of the number-related value acquisition unit 44, pixels (white pixels) representing particles are counted, and the counted number of pixels or a value obtained from the number of pixels (for example, the ratio of the number of pixels to the total number of pixels) is acquired as the number-related value.
　また、個数関連値取得部４４の別の実施態様としては、粒子を表す画素（白色の画素）が所定画素数以上に集まっている場合に、それらの画素の集まりを１つの粒子としてカウントして、そのカウントした粒子数を個数関連値として取得しても良い。 Also, as another embodiment of the number-related value acquisition unit 44, when pixels representing particles (white pixels) are gathered in a predetermined number of pixels or more, the collection of those pixels may be counted as one particle, and the counted number of particles may be acquired as the number-related value.
　このようにして取得された個数関連値は、個数関連値取得部４４から上下限フォーカス位置決定部４５に出力される。 The number-related value acquired in this manner is output from the number-related value acquisition unit 44 to the upper/lower limit focus position determination unit 45 .
　上下限フォーカス位置決定部４５は、オートフォーカス部４２が撮像手段３のフォーカスをセル１の手前側から奥側に移動させる過程で粒子が写り始めるフォーカス位置である下限フォーカス位置と、オートフォーカス部４２が撮像手段３のフォーカスをセル１の奥側から手前側に移動させる過程で粒子が写り始めるフォーカス位置である上限フォーカス位置とを決定するものである。なお、ここでいう粒子が写り始めるフォーカス位置とは、フォーカスの移動方向を逆にした場合においては、粒子が消え切るフォーカス位置である。 The upper/lower limit focus position determination unit 45 determines the lower limit focus position, which is the focus position where particles start to be captured in the process in which the autofocus unit 42 moves the focus of the imaging means 3 from the front side to the back side of the cell 1, and the upper limit focus position, which is the focus position in which the particles start to be captured in the process in which the autofocus unit 42 moves the focus of the imaging means 3 from the back side to the front side of the cell 1. It should be noted that the focus position where the particle starts to appear here is the focus position where the particle disappears when the direction of movement of the focus is reversed.
　なお、この上下限フォーカス位置決定部４５により決定される下限フォーカス位置及び上限フォーカス位置は、必ずしも粒子が写り始めた瞬間のフォーカス位置である必要はなく、写り始めてから僅かに変位したフォーカス位置であっても良い。 It should be noted that the lower limit focus position and upper limit focus position determined by the upper and lower limit focus position determination unit 45 do not necessarily have to be the focus position at the moment when the particle starts to be photographed, and may be a focus position slightly displaced after the particle starts to be photographed.
　そして、これらの下限フォーカス位置及び上限フォーカス位置は、後述の測定時に用いられる測定用フォーカス位置の算出に用いられる位置であり、いわば測定用フォーカス位置の基準となる位置である。 These lower limit focus position and upper limit focus position are positions used for calculation of the measurement focus position used in the measurement described later, and are positions that serve as a reference for the measurement focus position, so to speak.
　本実施形態の上下限フォーカス位置決定部４５は、上述した個数関連値取得部４４により取得された個数関連値と、所定の閾値とを比較することで下限フォーカス位置及び上限フォーカス位置を決定する。なお、下限フォーカス位置の決定に用いられる閾値と、上限フォーカス位置の決定に用いられる閾値とは、同じ値であっても良いし、異なる値であっても良い。 The upper/lower limit focus position determination unit 45 of the present embodiment determines the lower limit focus position and the upper limit focus position by comparing the number-related value acquired by the number-related value acquisition unit 44 described above with a predetermined threshold value. Note that the threshold used to determine the lower limit focus position and the threshold used to determine the upper limit focus position may be the same value or different values.
　ここで、撮像手段３のフォーカスをセル１の手前側から奥側に、又は、奥側から手前側に移動させた場合に、その移動の過程で得られる撮像データの示す画像について、図３（ｂ）を参照しながら考える。 Here, when the focus of the imaging means 3 is moved from the front side to the back side of the cell 1, or from the back side to the front side, the image shown by the imaging data obtained in the process of movement will be considered with reference to FIG. 3(b).
　これらの撮像データの示す画像には、図３（ｂ）に示すように、フォーカスを移動させ始めてからしばらくは粒子が写り込まず（図３のＸ）、とあるタイミングで粒子が写り始め（図３のＹ）、その後は写り込む粒子の数が増えていくはずである。 As shown in Fig. 3(b), the images shown by these imaging data do not show particles for a while after the focus is moved (X in Fig. 3), but at a certain timing (Y in Fig. 3), particles start to appear, and after that the number of particles should increase.
　つまり、フォーカスを移動させ始めてからしばらくは個数関連値に変動はなく、とあるタイミンで個数関連値に変動が生じるはずである。
　これは、フォーカスをセル１の手前側から奥側に移動させる場合と、フォーカスをセル１の奥側から手前側に移動させる場合とで共通していえることである。 In other words, the number-related value does not change for a while after the focus is moved, and the number-related value should change at a certain timing.
This is common to the case of moving the focus from the front side to the back side of the cell 1 and the case of moving the focus from the back side to the front side of the cell 1 .
　そこで、上下限フォーカス位置決定部４５は、撮像データそれぞれから取得された個数関連値と、所定の閾値とを順次比較していき、個数関連値が閾値を超えた場合に、その個数関連値が取得された撮像データに対応するフォーカス位置を下限フォーカス位置又は上限フォーカス位置として決定する。 Therefore, the upper/lower limit focus position determination unit 45 sequentially compares the number-related value obtained from each piece of imaging data with a predetermined threshold, and when the number-related value exceeds the threshold, determines the focus position corresponding to the imaging data from which the number-related value was obtained as the lower limit focus position or the upper limit focus position.
　このようにして決定された下限フォーカス位置及び上限フォーカス位置は、上下限フォーカス位置決定部４５から測定用フォーカス位置算出部４６に出力される。 The lower limit focus position and the upper limit focus position determined in this manner are output from the upper and lower limit focus position determination section 45 to the measurement focus position calculation section 46 .
　測定用フォーカス位置算出部４６は、下限フォーカス位置及び上限フォーカス位置に基づいて、これらの間のフォーカス位置であって測定時に用いられる測定用フォーカス位置を算出するものである。 The measurement focus position calculation unit 46 calculates, based on the lower limit focus position and the upper limit focus position, a measurement focus position that is a focus position between them and is used during measurement.
　この測定用フォーカス位置算出部４６は、例えば所定の算出式等を用いて測定用フォーカス位置を算出するように構成されており、算出された測定用フォーカス位置が、下限フォーカス位置と上限フォーカス位置との中間点を含む所定の長さの中間領域内に収まるように構成されている。
　なお、中間領域の占める長さは、下限フォーカス位置から上限フォーカス位置までの長さの半分以下であることが好ましく、１／３以下であることがより好ましい。 The measurement focus position calculator 46 is configured to calculate the measurement focus position using, for example, a predetermined calculation formula or the like, and is configured so that the calculated measurement focus position falls within an intermediate region of a predetermined length including the intermediate point between the lower limit focus position and the upper limit focus position.
The length occupied by the intermediate region is preferably half or less, more preferably ⅓ or less, of the length from the lower limit focus position to the upper limit focus position.
　本実施形態の測定用フォーカス位置算出部４６は、下限フォーカス位置と上限フォーカス位置との中間点を測定用フォーカス位置として算出する。
　ただし、測定用フォーカス位置算出部４６としては、例えば下限フォーカス位置又は上限フォーカス位置に重み付けをするなどして、これらの位置の中間点からずれた位置を測定用フォーカス位置として算出しても良い。 The measurement focus position calculator 46 of the present embodiment calculates the intermediate point between the lower limit focus position and the upper limit focus position as the measurement focus position.
However, the measurement focus position calculation unit 46 may, for example, weight the lower limit focus position or the upper limit focus position, and calculate a position shifted from the middle point of these positions as the measurement focus position.
　測定用フォーカス位置算出部４６により算出された測定用フォーカス位置は、上述したオートフォーカス部４２に出力されて、オートフォーカス部４２は、粒子径分布の測定前に、撮像手段３のフォーカスを測定用フォーカス位置に合わせる。 The measurement focus position calculated by the measurement focus position calculation unit 46 is output to the autofocus unit 42 described above, and the autofocus unit 42 focuses the imaging means 3 to the measurement focus position before measuring the particle size distribution.
　次に、粒子径分布測定装置１００による測定前の情報処理装置４０の動作について図４を参照しながら説明する。 Next, the operation of the information processing device 40 before measurement by the particle size distribution measuring device 100 will be described with reference to FIG.
　まず、例えばディスプレイ等に表示されているオートフォーカスボタンを操作すると、オートフォーカス部４２が、撮像手段３のフォーカスをセル１に対して進退移動させる。 First, for example, when an autofocus button displayed on a display or the like is operated, the autofocus unit 42 moves the focus of the imaging means 3 back and forth with respect to the cell 1 .
　本実施形態のオートフォーカス部４２は、撮像手段３のフォーカスをまずはセル１の手前側から奥側に例えば所定距離だけ移動させる（Ｓ１）。 The autofocus unit 42 of the present embodiment first moves the focus of the imaging means 3 from the front side of the cell 1 to the back side, for example, by a predetermined distance (S1).
　そして、その移動先で得られる撮像データが、撮像手段３から画像処理部４３に送られて、画像処理部４３が撮像データを二値化する（Ｓ２）。 Then, the imaging data obtained at the destination is sent from the imaging means 3 to the image processing section 43, and the image processing section 43 binarizes the imaging data (S2).
　次いで、個数関連値取得部４４が、二値化された撮像データから、例えば粒子を表す画素数をカウントするなどして個数関連値を取得する（Ｓ３）。 Next, the number-related value acquisition unit 44 acquires the number-related value from the binarized imaging data, for example, by counting the number of pixels representing particles (S3).
　続いて、上下限フォーカス位置決定部４５が、個数関連値取得部４４により取得されたそれぞれの個数関連値と閾値とを比較する（Ｓ４）。 Subsequently, the upper/lower limit focus position determining unit 45 compares each number-related value acquired by the number-related value acquiring unit 44 with a threshold value (S4).
　Ｓ４において、個数関連値が閾値に達していない場合、Ｓ１に戻り、再びフォーカスをセル１の手前側から奥側に所定距離だけ移動させる。 In S4, if the number-related value does not reach the threshold value, the process returns to S1, and the focus is again moved from the front side to the back side of cell 1 by a predetermined distance.
　一方、Ｓ４において、個数関連値が閾値を超えた場合、上下限フォーカス位置決定部４５は、その個数関連値が取得された撮像データに対応するフォーカス位置を下限フォーカス位置として決定する（Ｓ５）。 On the other hand, if the number-related value exceeds the threshold in S4, the upper/lower limit focus position determination unit 45 determines the focus position corresponding to the imaging data from which the number-related value was acquired as the lower limit focus position (S5).
　これにより、Ｓ１におけるフォーカスをセル１の手前側から奥側に移動させる動作が終了する。 Thus, the operation of moving the focus in S1 from the front side of cell 1 to the back side is completed.
　続いて、オートフォーカス部４２が、撮像手段３のフォーカスをセル１の奥側から手前側に例えば所定距離だけ移動させる（Ｓ６）。 Subsequently, the autofocus unit 42 moves the focus of the imaging means 3 from the back side of the cell 1 to the front side, for example, by a predetermined distance (S6).
　そして、その移動先で得られる撮像データが、撮像手段３から画像処理部４３に送られて、画像処理部４３が撮像データを二値化する（Ｓ７）。 Then, the imaging data obtained at the destination is sent from the imaging means 3 to the image processing section 43, and the image processing section 43 binarizes the imaging data (S7).
　次いで、個数関連値取得部４４が、二値化された撮像データから、例えば粒子を表す画素数をカウントするなどして個数関連値を取得する（Ｓ８）。なお、よりフォーカス位置をより高精度に合わせるべく、物体認識などの処理を行っても良い。 Next, the number-related value acquisition unit 44 acquires the number-related value from the binarized imaging data, for example, by counting the number of pixels representing particles (S8). Note that processing such as object recognition may be performed in order to adjust the focus position with higher accuracy.
　続いて、上下限フォーカス位置決定部４５が、個数関連値取得部４４により取得されたそれぞれの個数関連値と閾値とを比較する（Ｓ９）。 Subsequently, the upper/lower limit focus position determining unit 45 compares each number-related value acquired by the number-related value acquiring unit 44 with a threshold value (S9).
　Ｓ９において、個数関連値が閾値に達していない場合、Ｓ６に戻り、再びフォーカスをセル１の奥側から手前側に所定距離だけ移動させる。 In S9, if the number-related value has not reached the threshold value, the process returns to S6, and the focus is again moved from the back side of cell 1 to the front side by a predetermined distance.
　一方、Ｓ９において、個数関連値が閾値を超えた場合、上下限フォーカス位置決定部４５は、その個数関連値が取得された撮像データに対応するフォーカス位置を上限フォーカス位置として決定する（Ｓ１０）。 On the other hand, if the number-related value exceeds the threshold in S9, the upper/lower limit focus position determining unit 45 determines the focus position corresponding to the imaging data from which the number-related value was acquired as the upper limit focus position (S10).
　これにより、Ｓ６におけるフォーカスをセル１の奥側から手前側に移動させる動作が終了する。 This completes the operation of moving the focus from the back side of cell 1 to the front side in S6.
　その後、上下限フォーカス位置決定部４５により決定された下限フォーカス位置及び上限フォーカス位置が測定用フォーカス位置算出部４６に送られて、測定用フォーカス位置算出部４６が、ここでは下限フォーカス位置及び上限フォーカス位置の中間点を測定用フォーカス位置として算出する（Ｓ１１）。 After that, the lower limit focus position and the upper limit focus position determined by the upper and lower limit focus position determination unit 45 are sent to the measurement focus position calculation unit 46, and the measurement focus position calculation unit 46 calculates the middle point between the lower limit focus position and the upper limit focus position as the measurement focus position (S11).
　そして、この測定用フォーカス位置は、再びオートフォーカス部４２に出力されて、オートフォーカス部４２が、撮像手段３のフォーカスを測定用フォーカス位置に移動させる（Ｓ１２）。 Then, this measurement focus position is output to the autofocus section 42 again, and the autofocus section 42 moves the focus of the imaging means 3 to the measurement focus position (S12).
　上述したオートフォーカス機能を発揮させて撮像手段３のフォーカスが測定用フォーカス位置に合わせ、この状態において粒子径分布を測定することで（Ｓ１３）、精度の良い測定を行うことができる。 Accurate measurement can be performed by activating the above-described autofocus function to focus the imaging means 3 on the focus position for measurement and measuring the particle size distribution in this state (S13).
＜本実施形態の効果＞
　このように構成された本実施形態の粒子径分布測定装置１００によれば、撮像手段３のフォーカスをセルに対して移動させることにより、下限フォーカス位置及び上限フォーカス位置が決定し、これらの位置に基づいて測定用フォーカス位置が算出されるので、既存のオートフォーカス機能と比べて短時間で且つ高い成功確率で測定用フォーカス位置を算出することができる。
　これにより、ＰＴＡ法による粒子径分布測定において、フォーカス位置を短時間で自動的に合わせることが可能となり、従来の手動によるフォーカス調整の手間を省くことができる。 <Effects of this embodiment>
According to the particle size distribution measuring apparatus 100 of the present embodiment configured as described above, the lower limit focus position and the upper limit focus position are determined by moving the focus of the imaging means 3 with respect to the cell, and the measurement focus position is calculated based on these positions. Therefore, the measurement focus position can be calculated in a short time and with a high probability of success compared to the existing autofocus function.
Thereby, in the particle size distribution measurement by the PTA method, it becomes possible to automatically adjust the focus position in a short time, and the conventional manual focus adjustment can be saved.
　また、個数関連値取得部４４が、二値化された撮像データを用いて個数関連値を取得するので、個数関連値を取得するうえでの計算量が少なくて済み、処理速度の向上を図ることができ、その結果、短時間でフォーカス位置を自動的に合わせることが可能となる。 In addition, since the number-related value acquiring unit 44 acquires the number-related value using the binarized imaging data, the amount of calculation for acquiring the number-related value can be reduced, the processing speed can be improved, and as a result, the focus position can be automatically adjusted in a short time.
　さらに、本実施形態の情報処理装置４０は、上限フォーカス位置及び下限フォーカス位置の決定、測定用フォーカス位置の算出、及び、フォーカスの測定用フォーカス位置への位置調整の全てを自動で行うので、作業者の手間を一層減らすことができる。 Furthermore, the information processing apparatus 40 of the present embodiment automatically determines the upper limit focus position and the lower limit focus position, calculates the focus position for measurement, and adjusts the focus to the focus position for measurement.
＜その他の実施形態＞
　なお、本発明は前記実施形態に限られるものではない。 <Other embodiments>
It should be noted that the present invention is not limited to the above embodiments.
　例えば、粒子径分布測定装置１００としては、図５に示すように、セル１内の粒子を攪拌させる攪拌手段５をさらに備えていても良い。
　この場合、情報処理装置４としては、図６に示すように、オートフォーカス機能による撮像手段３のフォーカスの位置調整（Ｔ１）と、分析部４１による粒子径分布の算出（Ｔ２）と、撹拌手段７によるセル１内の粒子の撹拌（Ｔ３）とのそれぞれを複数回繰り返す制御部を備えていても良い。
　このような構成であれば、ＰＴＡ法による測定において、測定回数を増やすことができる（すなわち、測定対象粒子数を増やすことができる）うえ、撹拌の度に撮像手段３のフォーカスを自動で合わせることができ、短時間で手間をかけずに測定精度のさらなる向上を図れる。 For example, the particle size distribution measuring apparatus 100 may further include stirring means 5 for stirring the particles in the cell 1, as shown in FIG.
In this case, as shown in FIG. 6, the information processing device 4 may include a control unit that repeats the position adjustment (T1) of the focus of the imaging means 3 by the autofocus function, the calculation (T2) of the particle size distribution by the analysis unit 41, and the stirring (T3) of the particles in the cell 1 by the stirring means 7, respectively.
With such a configuration, in the measurement by the PTA method, the number of measurements can be increased (that is, the number of particles to be measured can be increased), and the imaging means 3 can be automatically focused each time the mixture is stirred, so that the measurement accuracy can be further improved in a short time without much effort.
　また、個数関連値取得部４４は、本実施形態では二値化された画像データに基づいて個数関連値を取得していたが、二値化とは異なる画像処理後の画像データに基づいて個数関連値を取得しても良い。 In addition, although the number-related value acquisition unit 44 acquires the number-related value based on the binarized image data in this embodiment, it may acquire the number-related value based on the image data after image processing different from binarization.
　さらに、個数関連値取得部４４としては、画像処理されていない撮像データに基づいて個数関連値を取得しても良い。この場合、情報処理装置４としては、画像処理部４３としての機能を省くことができる。 Furthermore, the number-related value acquisition unit 44 may acquire the number-related value based on the imaging data that has not undergone image processing. In this case, the function of the image processing unit 43 can be omitted from the information processing device 4 .
　そのうえ、情報処理装置４としては、上下限フォーカス位置決定部４５を必ずしも備えている必要はない。
　この場合の情報処理装置４の実施態様としては、例えば入力手段等を介して下限フォーカス位置及び上限フォーカス位置を入力できるようにしておき、測定用フォーカス位置算出部４６が、その入力された下限フォーカス位置及び上限フォーカス位置を用いて測定用フォーカス位置を算出する態様を挙げることができる。 In addition, the information processing device 4 does not necessarily need to include the upper/lower limit focus position determination unit 45 .
As an embodiment of the information processing device 4 in this case, for example, it is possible to input the lower limit focus position and the upper limit focus position via an input means or the like, and the measurement focus position calculation unit 46 calculates the measurement focus position using the input lower limit focus position and upper limit focus position.
　また、上下限フォーカス位置決定部４５は、前記実施形態では下限フォーカス位置を決定した後に上限フォーカス位置を決定していたが、上限フォーカス位置を決定した後に下限フォーカス位置を決定するように構成されていても良い。 In addition, the upper and lower limit focus position determination unit 45 determines the upper limit focus position after determining the lower limit focus position in the above embodiment, but may be configured to determine the lower limit focus position after determining the upper limit focus position.
　さらに、前記実施形態では、撮像手段３のフォーカスをセル１に対して所定距離ずつ移動させることで下限フォーカス位置及び上限フォーカス位置を決定していたが、撮像手段３のフォーカスをセル１に対して連続的に移動させていき、その過程で撮像手段３が撮像する撮像データに基づいて、下限フォーカス位置及び上限フォーカス位置を決定しても良い。 Furthermore, in the above-described embodiment, the focus of the imaging means 3 is moved by a predetermined distance with respect to the cell 1 to determine the lower limit focus position and the upper limit focus position. However, the focus of the imaging means 3 may be continuously moved with respect to the cell 1, and the lower limit focus position and the upper limit focus position may be determined based on the imaging data captured by the imaging means 3 in the process.
　さらに加えて、粒子径分布測定装置１００としては、撮像手段３の実際のフォーカス位置を例えば数値等を用いてディスプレイ等に表示する表示部を備えていても良い。
　具体的にこの表示部は、フォーカスを移動させている際に、そのフォーカス位置をリアルタムに表示する態様を挙げることができる。
　さらに、表示部としては、撮像手段３により得られる撮像データの示す画像を、フォーカスを移動させている際、及び／又は、オートフォーカス動作の完了後に、ディスプレイ等に表示するように構成されていても良い。 In addition, the particle size distribution measuring apparatus 100 may be provided with a display section for displaying the actual focus position of the imaging means 3 using, for example, numerical values.
Concretely, this display unit may display the focus position in real time while the focus is being moved.
Furthermore, the display unit may be configured to display an image indicated by the imaging data obtained by the imaging means 3 on a display or the like while the focus is being moved and/or after the autofocus operation is completed.
　また、粒子径分布測定装置１００としては、例えばオートフォーカス動作の完了後などにフォーカス位置を微調整できるようにするべく、撮像手段３のフォーカスを手動で変更できるように構成されていても良い。この場合の実施態様としては、例えばディスプレイ等にフォーカス位置変更ボタンを表示しておき、このボタンを操作することにより、撮像手段３のフォーカスを手動で変更できるようになる態様を挙げることができる。 In addition, the particle size distribution measuring device 100 may be configured so that the focus of the imaging means 3 can be manually changed so that the focus position can be finely adjusted, for example, after the autofocus operation is completed. As an embodiment in this case, for example, a focus position change button may be displayed on a display or the like, and by operating this button, the focus of the imaging means 3 can be manually changed.
　その他、本発明は前記実施形態に限られず、その趣旨を逸脱しない範囲で種々の変形が可能であるのは言うまでもない。 In addition, it goes without saying that the present invention is not limited to the above-described embodiments, and that various modifications are possible without departing from the spirit of the present invention.
　上記した本発明によれば、ＰＴＡ法による粒子径分布測定において、フォーカス位置を短時間で自動的に合わせることができる。 According to the present invention described above, the focus position can be automatically adjusted in a short time in the particle size distribution measurement by the PTA method.
１００・・・粒子径分布測定装置
１　　・・・セル
２　　・・・光照射部
３　　・・・撮像手段
４　　・・・情報処理装置
４１　・・・分析部
４２　・・・オートフォーカス部
４３　・・・画像処理部
４４　・・・個数関連値取得部
４５　・・・上下限フォーカス位置決定部
４６　・・・測定用フォーカス位置算出部
 
 

  100 Particle size distribution measuring device 1 Cell 2 Light irradiation unit 3 Imaging means 4 Information processing device 41 Analysis unit 42 Autofocus unit 43 Image processing unit 44 Number-related value acquisition unit 45 Upper and lower limit focus position determination unit 46 Focus position calculation unit for measurement

Claims (8)

  1. 　セル内の粒子を撮像する撮像手段と、
    　前記撮像手段により得られる撮像データに基づいて、粒子のブラウン運動による拡散速度を算出することにより粒子径分布を算出する分析部と、を備える粒子径分布測定装置であって、
    　前記撮像手段のフォーカスを前記セルの手前側から奥側に移動させる過程で粒子が写り始めるフォーカス位置である下限フォーカス位置と、前記撮像手段のフォーカスを前記セルの奥側から手前側に移動させる過程で粒子が写り始めるフォーカス位置である上限フォーカス位置とを決定する上下限フォーカス位置決定部と、
    　前記下限フォーカス位置及び前記上限フォーカス位置に基づいて、これらの間のフォーカス位置であって測定時に用いる測定用フォーカス位置を算出する測定用フォーカス位置算出部と、
    　前記撮像手段のフォーカスを、測定時に前記測定用フォーカス位置に合わせるオートフォーカス部と、を備えることを特徴とする粒子径分布測定装置。     imaging means for imaging particles in the cell;
    a particle size distribution measuring device comprising: an analysis unit that calculates a particle size distribution by calculating a diffusion speed due to Brownian motion of particles based on imaging data obtained by the imaging means,
    an upper and lower limit focus position determination unit that determines a lower limit focus position, which is a focus position where particles start to be captured in the process of moving the focus of the imaging means from the front side to the back side of the cell, and an upper limit focus position, which is the focus position where particles start to be captured in the process of moving the focus of the imaging means from the back side to the front side of the cell;
    a measurement focus position calculation unit that calculates, based on the lower limit focus position and the upper limit focus position, a measurement focus position that is a focus position between them and is used at the time of measurement;
    A particle size distribution measuring apparatus, comprising: an autofocus unit that adjusts the focus of the imaging means to the measurement focus position during measurement.
  2. 　前記撮像データから粒子の個数に関する個数関連値を取得する個数関連値取得部をさらに備え、
    　前記上下限フォーカス位置決定部が、前記個数関連値取得部により取得された前記個数関連値と所定の閾値とを比較することで、前記下限フォーカス位置及び前記上限フォーカス位置を決定することを特徴とする請求項１記載の粒子径分布測定装置。     further comprising a number-related value acquisition unit that acquires a number-related value related to the number of particles from the imaging data;
    2. The particle size distribution measuring apparatus according to claim 1, wherein the upper and lower limit focus position determination unit determines the lower limit focus position and the upper limit focus position by comparing the number-related value acquired by the number-related value acquisition unit with a predetermined threshold value.
  3. 　前記撮像データを画像処理する画像処理部をさらに備え、
    　前記個数関連値取得部が、前記画像処理部により二値化された前記撮像データから前記個数関連値を取得することを特徴とする請求項２記載の粒子径分布測定装置。     further comprising an image processing unit that performs image processing on the imaging data,
    3. The particle size distribution measuring apparatus according to claim 2, wherein the number-related value acquiring unit acquires the number-related value from the imaging data binarized by the image processing unit.
  4. 　前記測定用フォーカス位置算出部により算出された前記測定用フォーカス位置が、前記下限フォーカス位置と前記上限フォーカス位置との中間点を含む所定の長さの中央領域内に収まっていることを特徴とする請求項１記載の粒子径分布測定装置。 The particle size distribution measuring device according to claim 1, wherein the measurement focus position calculated by the measurement focus position calculation unit is within a central region of a predetermined length including an intermediate point between the lower limit focus position and the upper limit focus position.
  5. 　前記セル内の粒子を攪拌させる攪拌手段をさらに備えることを特徴とする請求項１記載の粒子径分布測定装置。 The particle size distribution measuring device according to claim 1, further comprising stirring means for stirring the particles in the cell.
  6. 　前記撹拌手段による前記セル内の粒子の撹拌と、前記オートフォーカス部による前記撮像手段のフォーカスの位置合わせと、前記粒子径分布の測定とを繰り返す制御部を備えている、請求項５記載の粒子径分布測定装置。 6. The particle size distribution measuring apparatus according to claim 5, comprising a control unit that repeats stirring of the particles in the cell by the stirring unit, alignment of the focus of the imaging unit by the autofocus unit, and measurement of the particle size distribution.
  7. 　セル内の粒子を撮像する撮像手段と、前記撮像手段により得られる撮像データに基づいて、粒子のブラウン運動による拡散速度を算出することにより粒子径分布を算出する分析部と、を備える粒子径分布測定装置を用いた粒子径分布測定方法であって、
    　前記撮像手段のフォーカスを前記セルの手前側から奥側に移動させる過程で粒子が写り始めるフォーカス位置である下限フォーカス位置と、前記撮像手段のフォーカスを前記セルの奥側から手前側に移動させる過程で粒子が写り始めるフォーカス位置である上限フォーカス位置とを決定する上下限フォーカス位置決定ステップと、
    　前記下限フォーカス位置及び前記上限フォーカス位置に基づいて、これらの間のフォーカス位置であって測定時に用いる測定用フォーカス位置を算出する測定用フォーカス位置算出ステップと、
    　前記撮像手段のフォーカスを、測定時に前記測定用フォーカス位置に合わせるオートフォーカスステップと、を備えることを特徴とする粒子径分布測定方法。     A particle size distribution measuring method using a particle size distribution measuring device comprising: an imaging means for imaging particles in a cell; and an analysis section for calculating a particle size distribution by calculating diffusion speed due to Brownian motion of particles based on imaging data obtained by the imaging means,
    an upper and lower limit focus position determining step of determining a lower limit focus position, which is a focus position at which particles start to be captured in the process of moving the focus of the imaging means from the front side to the back side of the cell, and an upper limit focus position, which is the focus position at which particles start to be captured in the process of moving the focus of the imaging means from the back side to the front side of the cell;
    a measurement focus position calculating step of calculating a measurement focus position that is a focus position between the lower limit focus position and the upper limit focus position and is used during measurement;
    and an autofocus step of adjusting the focus of the imaging means to the measurement focus position during measurement.
  8. 　セル内の粒子を撮像する撮像手段と、
    　前記撮像手段により得られる撮像データに基づいて、粒子のブラウン運動による拡散速度を算出することにより粒子径分布を算出する分析部と、を備える粒子径分布測定装置に用いられる粒子径分布測定用プログラムであって、
    　前記撮像手段のフォーカスを前記セルの手前側から奥側に移動させる過程で粒子が写り始めるフォーカス位置である下限フォーカス位置と、前記撮像手段のフォーカスを前記セルの奥側から手前側に移動させる過程で粒子が写り始めるフォーカス位置である上限フォーカス位置とを決定する上下限フォーカス位置決定部と、
    　前記下限フォーカス位置及び前記上限フォーカス位置に基づいて、これらの間のフォーカス位置であって測定時に用いる測定用フォーカス位置を算出する測定用フォーカス位置算出部と、
    　前記撮像手段のフォーカスを、測定時に前記測定用フォーカス位置に合わせるオートフォーカス部としての機能をコンピュータに実行させることを特徴とする粒子径分布測定用プログラム。

          imaging means for imaging particles in the cell;
    A particle size distribution measuring program used in a particle size distribution measuring apparatus comprising: an analysis unit that calculates a particle size distribution by calculating a diffusion speed due to Brownian motion of particles based on imaging data obtained by the imaging means,
    an upper and lower limit focus position determination unit that determines a lower limit focus position, which is a focus position where particles start to be captured in the process of moving the focus of the imaging means from the front side to the back side of the cell, and an upper limit focus position, which is the focus position where particles start to be captured in the process of moving the focus of the imaging means from the back side to the front side of the cell;
    a measurement focus position calculation unit that calculates, based on the lower limit focus position and the upper limit focus position, a measurement focus position that is a focus position between them and is used at the time of measurement;
    A program for particle size distribution measurement, characterized by causing a computer to execute a function as an auto-focus section for adjusting the focus of the imaging means to the measurement focus position during measurement.
PCT/JP2023/001117 2022-01-20 2023-01-17 Particle size distribution measurement device, particle size distribution measurement method, and program for particle size distribution measurement WO2023140235A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022-006935 2022-01-20
JP2022006935 2022-01-20

Publications (1)

Publication Number Publication Date
WO2023140235A1 true WO2023140235A1 (en) 2023-07-27

Family

ID=87348832

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/001117 WO2023140235A1 (en) 2022-01-20 2023-01-17 Particle size distribution measurement device, particle size distribution measurement method, and program for particle size distribution measurement

Country Status (1)

Country Link
WO (1) WO2023140235A1 (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008007743B3 (en) * 2008-02-05 2009-05-14 Particle Metrix Gmbh Optical detection device for particulate matter of e.g. cosmetic emulsion in pharmaceutical application, has optical radiation device, where approximation of position of focus of device and monitoring device or vice versa is monitored
CN105259081A (en) * 2015-10-22 2016-01-20 河海大学 Brownian motion measuring instrument and measuring method
JP2016519759A (en) * 2013-03-15 2016-07-07 アイリス インターナショナル， インコーポレイテッド Automatic focusing system and method for analysis of particles in blood samples
WO2017104662A1 (en) * 2015-12-18 2017-06-22 株式会社堀場製作所 Particle analysis device and particle analysis method
JP2020204604A (en) * 2019-06-12 2020-12-24 株式会社堀場製作所 Particle analyzer and particle analysis method
WO2021187122A1 (en) * 2020-03-17 2021-09-23 リオン株式会社 Particle measurement device and particle measurement method
CN113689456A (en) * 2021-08-18 2021-11-23 山东大学 Exosome particle size analysis device and method based on deep learning

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008007743B3 (en) * 2008-02-05 2009-05-14 Particle Metrix Gmbh Optical detection device for particulate matter of e.g. cosmetic emulsion in pharmaceutical application, has optical radiation device, where approximation of position of focus of device and monitoring device or vice versa is monitored
JP2016519759A (en) * 2013-03-15 2016-07-07 アイリス インターナショナル， インコーポレイテッド Automatic focusing system and method for analysis of particles in blood samples
CN105259081A (en) * 2015-10-22 2016-01-20 河海大学 Brownian motion measuring instrument and measuring method
WO2017104662A1 (en) * 2015-12-18 2017-06-22 株式会社堀場製作所 Particle analysis device and particle analysis method
JP2020204604A (en) * 2019-06-12 2020-12-24 株式会社堀場製作所 Particle analyzer and particle analysis method
WO2021187122A1 (en) * 2020-03-17 2021-09-23 リオン株式会社 Particle measurement device and particle measurement method
CN113689456A (en) * 2021-08-18 2021-11-23 山东大学 Exosome particle size analysis device and method based on deep learning

Similar Documents

Publication Publication Date Title
JP5254441B2 (en) Flow type particle image analysis method and apparatus
US20210215923A1 (en) Microscope system
JPH07120375A (en) Method and apparatus for flow-type particle image analysis
JP2007304044A (en) Particle image analyzer
JP2018039028A (en) Laser processing machine and laser processing method
JP6605716B2 (en) Automatic staining detection in pathological bright field images
KR20090053741A (en) Optical three-dimensional measuring apparatus and filter processing method
JP4043417B2 (en) Particle size measuring device
CN109596619B (en) Device for analyzing physical components in urine
US10527404B2 (en) Auto-focus method for a coordinate measuring device
JP2006171024A (en) Multi-point fluorescence spectrophotometry microscope and multi-point fluorescence spectrophotometry method
WO2023140235A1 (en) Particle size distribution measurement device, particle size distribution measurement method, and program for particle size distribution measurement
US20200158633A1 (en) Sample observation device and sample observation method
US10298833B2 (en) Image capturing apparatus and focusing method thereof
JP2007322259A (en) Edge detecting method, apparatus and program
JP5050282B2 (en) Focus detection device, focus detection method, and focus detection program
JP2002062251A (en) Flow type particle image analyzing method and device
JP6638526B2 (en) Particle size distribution measuring device and particle size distribution measuring method
CN114994895A (en) Method and device for the light-sheet microscopic examination of a sample
JP2010121955A (en) Height information acquisition device, height information acquisition method, and program
TWI395047B (en) Automatic focusing method and image capture apparatus using the same
JP2015210396A (en) Aligment device, microscope system, alignment method and alignment program
WO2019244275A1 (en) Observation device
JP2015102694A (en) Alignment device, microscopic system, alignment method, and alignment program
JPH06221986A (en) Flow-type method and apparatus for analyzing particle image

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23743229

Country of ref document: EP

Kind code of ref document: A1