JP2010101881A - Particle photographing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a particle photographing apparatus for solving the problem of the blur of a particle image in a direct photographing method without damaging the beneficial point of the direct photographing method and measuring the feature quantity of particles. <P>SOLUTION: The particle photographing apparatus (1) is equipped with the probe (1a) inserted into fluid containing a particle group (P), a photographing device (10) for imaging the particle group, and illumination means (5 and 6) for supplying background illumination. The axial part of the probe has a particle group passage traversing the axial part and a passage width regulating means (4) for regulating the passage width of the particle group passage so that the particle group may pass through the range of the depth of the projection field of the photographing device. The particles floating in the fluid certainly passes through the range of the depth of the projection field of the photographing device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a particle photographing apparatus used in a measurement technique of fine particle group behavior that densely disperses and flies in a gas or liquid. In particular, the present invention is a probe type that can be used in a particle imaging / measuring system for measuring particle feature quantities such as particle velocity, particle diameter, and particle shape of particles in a group of fine particles densely dispersed and flying in a gas or liquid. The present invention relates to a particle imaging apparatus.

  Known methods for measuring the particle velocity, particle diameter, etc. of particles contained in a group of fine particles dispersed and flying in gas or liquid include phase Doppler, shadow Doppler, direct imaging, and laser interference imaging. Yes.

  As described in Non-Patent Document 1, the direct imaging method illuminates from behind the particles flying in a dispersed manner and takes a shadow photograph of the particles with an imaging device such as a CCD camera arranged at a position facing the illumination device. Thus, this is a technique for measuring the speed and size of individual particles. In direct imaging, a measurement system can be configured using a relatively inexpensive device, and it can be easily measured without the need for complicated adjustments and calibrations. Has been used.

  In the direct imaging method, the particle diameter, the particle shape, and the like can be measured by image analysis of a shadow photograph of the captured particle. In addition, by double exposure shooting, high-speed camera shooting, frame laser shooting using a pulse laser and a digital CCD camera, etc., the flying particles are continuously shot at short time intervals to measure the flying distance of the particles. By dividing the measured value by the time interval, the flying speed of the particles can be measured.

  According to the direct imaging method, the measurement can be performed without being affected by the particle shape. Therefore, the direct imaging method has a wider application range than the phase Doppler method and the laser interference imaging method which assume that the particle shape is a true sphere. There is an advantage.

  In such a direct imaging method, when the fine particles are illuminated from the front, complicated light scattering characteristics depending on the particle shape and material appear. For this reason, the photographed particle image does not reflect the size or shape of the particle, and therefore cannot satisfy the requirements for particle measurement. Under such circumstances, in the direct imaging method, it is necessary to perform background illumination that illuminates particles from the back. Therefore, as shown in Patent Document 1, the illumination device and the imaging device sandwich the particle group to be measured. Are arranged at positions facing each other.

  However, in the direct imaging method, since all particles existing between the imaging device and the illumination device arranged opposite to each other are imaged, a position outside the depth of field at a position before or behind the measurement point The problem arises that the image of particles present in the image is blurred. When image blurring occurs, a small particle image cannot be detected, and the measurement value obtained from the result of capturing a large particle image increases its error. As a countermeasure, it has been necessary to devise a method for specifying the position in the depth direction of the photographed particle by some method and excluding the particle image outside the depth of field from the measurement target.

  The following methods have been proposed in the past as specific means for excluding particle images outside the depth of field from the measurement target.

  (1) The position of the particle in the depth direction is specified using the characteristics of the diffraction ring generated around the particle image photographed with background illumination (Non-patent Documents 2 and 3).

  (2) Determining the position of the particle in the depth direction based on the sharpness of the luminance change at the edge of the particle image taken with background illumination (Non-Patent Document 4, Non-Patent Document 5).

  (3) The depth direction position of the particle is determined based on the luminance gradient at the particle image edge photographed with background illumination (Non-Patent Document 6).

  (4) By devising the particle supply device, the particle group is guided so that the particle group exists only within the depth of field (Patent Document 1).

JP 2001-74638 A

Chigier, N., 1983, "Drop size and velocity instrumentation, Progress in Energy and Combustion Science", Vol. 9, pp. 155-177. De Corso, S. M., 1960, "Effect of ambient and fuel pressure on spray dropsize", Transactions of the ASME, Journal of Engineering for Power, Vol.82, pp. 10-18. Takeichiro Takeuchi, Hiromi Murayama, Jiro Senda and Koji Yamada, 1982, “Particle size distribution of diesel spray in a constant pressure vessel”, Transactions of the Japan Society of Mechanical Engineers (Part B), 48, 433, pp. 1801-1810 . Ow, CS and Crane, RI, 1980, "A simple off-line automatic image analysis system with application to drop sizing in two-phase flows", International Journalof Heat and Fluid Flow, Vol. 2, No. 1, pp. 47-53. Ow, C. S. and Crane, R. I., 1981, "Pattern recognition procedures for a television-minicomputer spraydroplet sizing system", Journal of the Institute of Energy, Vol. 9, pp.119-123. Weiss, B. A., Derov, P., DeBiase, D. and Simmons, H. C., 1984, "Fluidparticle sizing using a fully automated optical imaging system", OpticalEngineering, Vol. 23, No. 5, pp. 561-566.

  However, in the measurement methods described in Non-Patent Documents 2 to 6, it is necessary to calibrate the relationship between the information extracted from the luminance distribution of the particle image and the position in the depth direction of the particle in advance, and complicated adjustments are required. The advantage of direct imaging is that it can be measured easily without the need for calibration.

  Further, the measurement method described in Patent Document 1 is a method limited to the case where the particle supply device can be devised and the particle group can be guided within the depth of field. Like measurement of particle groups ejected from the bell into space, it is difficult to adapt to measurement of particle groups having properties or conditions in which the behavior and movement of the particle groups are difficult to control.

  The present invention has been made in view of such problems, and the object of the present invention is to directly shoot without losing the advantages of the direct photographing method that can be easily measured without requiring complicated adjustment and calibration. It is an object of the present invention to provide a particle imaging apparatus capable of solving the problem of particle image blur that may occur in the law.

In order to achieve the above object, the present invention provides a particle imaging apparatus for measuring a particle feature amount,
A probe unit inserted into a fluid containing suspended particles or flying particles; and
An imaging device that images the particles of the particle group via an optical path formed in an axial core portion of the probe unit;
Illuminating means for supplying background illumination from the distal end portion of the probe portion toward the proximal end portion of the probe portion;
The shaft portion of the probe portion is open to the outer surface of the probe portion, and the passage of the particle group penetrating the shaft portion in a direction transverse to the axis of the shaft portion; There is provided a particle imaging apparatus comprising passage width restricting means for restricting the passage width of a particle group passage to a size corresponding to the depth of field so as to pass through a range of depth of field.

  According to the particle imaging apparatus of the present invention, by inserting a probe part into a densely flying particle group or the like, particles suspended in the fluid are allowed to flow into the particle group passage of the probe part and the particle is imaged. The image data of the particles can be acquired by the background light for the purpose.

  Further, according to the present invention, the particle group approaching the opening of the particle group passage passes through the particle group passage. The imaging device images particles of a particle group in the presence of background illumination. The passage width restricting means restricts the passage width of the particle group passage to a size corresponding to the depth of field, and the particle group reliably passes through the range of the depth of field of the photographing apparatus. Therefore, according to the particle imaging apparatus of the present invention, the passage position of the particle group to be imaged is limited to the depth of field, so that the particle can be imaged without blurring the particle image. Further, according to the particle imaging apparatus of the present invention, it is possible to omit the trouble of determining or estimating the depth of field by predicting the passing area of the particle group at the time of imaging, so that the particle measurement can be efficiently performed. Can be implemented.

  Furthermore, according to the particle imaging apparatus of the present invention, a measurement probe (probe) in which two optical systems, an optical system for supplying background illumination and an optical system for imaging a particle group, are provided on the same shaft or cylinder. ) Type probe-like device configuration can be employed. Such a particle imaging apparatus in the form of a probe is extremely advantageous because the detection unit or the detection unit can be easily inserted into a desired position inside the particle group.

  From another viewpoint, the present invention provides a particle imaging / measurement system having a particle imaging apparatus having the above-described configuration and a measurement unit that stores the captured image and measures the particle feature amount using the particle image processing unit. To do.

  According to the particle imaging / measurement system of the present invention, a probe unit in which an imaging system and an illumination system are integrated in a compact manner is inserted into the dense particle group, thereby measuring the particle feature amount inside the dense particle group. be able to.

  In the present invention, the particle group is a concept including a large number of solid particles, a large number of semi-solid particles, a large number of liquid droplets, and a particle group in which these solid, semi-solid, and liquid particles are mixed. A fluid is a concept including a gas and a liquid.

  The particle imaging apparatus of the present invention eliminates the problem of blurring of the particle image that can occur in the direct imaging method without losing the advantages of the direct imaging method that can be easily measured without requiring complicated adjustments and calibrations. Can do.

1 is a schematic perspective view of a particle imaging / measurement system including a particle imaging apparatus according to a preferred embodiment of the present invention. It is the top view, side view, and front view which show the structure of the particle | grain imaging device shown in FIG. FIG. 3 is a plan view, a side view, a transverse sectional view (II-I sectional view) and a longitudinal sectional view (II-II sectional view) showing the structure of the probe portion. It is a perspective view of the particle | grain imaging device which shows the other Example of this invention. It is the top view of the probe part which shows the further another Example of this invention, a side view, a cross-sectional view, and a longitudinal cross-sectional view. It is the longitudinal cross-sectional view which shows the probe part which concerns on the further another Example of this invention in the measurement position of a particle | grain attracting apparatus, the III-III sectional view, and the IV-IV sectional view. It is the longitudinal cross-sectional view which shows the probe part shown in FIG. 6 in the retraction position of a particle | grain attracting apparatus, the VV sectional view, and the VI-VI sectional view. 8 (A) and 8 (B) are cross-sectional views showing the structure of a probe portion having an extendable cross-linking portion, and FIG. 8 (C) is a VII-VII line in FIG. 8 (B). FIG. FIG. 9A and FIG. 9B are vertical cross-sectional views showing the configuration of the probe portion provided with the sliding cylindrical shutter.

  According to a preferred embodiment of the present invention, the passage width restricting means comprises a slit extending in the circumferential direction of the shaft portion of the probe portion. The mechanism of the particle passage hole or passage opening formed by the slit acts so that the particle group passes through a region within the depth of field in the cylinder or tube of the probe portion. The slit forms an inflow side opening and an outflow side opening for allowing a fluid containing the particle group to flow into or out of the particle group channel on the outer surface of the probe unit, and is orthogonal to the axis of the shaft unit of the probe unit A fluid flow is formed in the passage. Preferably, the slit has a substantially uniform width, and the flow path formed by the slit extends in a direction orthogonal to the axis of the shaft portion of the probe portion. More preferably, the center line of the slit is located in a plane perpendicular to the axis of the shaft part and including the focal point of the particle imaging apparatus, and the axis of the shaft part of the probe part is located in the cylinder or in the tube region of the probe part. A flow of fluid perpendicular to is formed.

  According to the particle imaging apparatus configured as described above, the passage position of the fluid including the particle group can be limited to the depth of field by the slit-type passage hole mechanism or the passage opening mechanism, so that the time In addition, it is possible to omit the depth-of-field adjustment operation at the time of photographing that requires labor. In addition, since it is possible to easily measure the fluid without requiring skill, it is possible to greatly improve the workability of capturing the particle feature amount.

  Further, according to the particle imaging apparatus having the above-described configuration, by inserting only the portion of the probe portion having a slit into the densely flying particle group, the particles to be imaged are covered by the particle imaging apparatus. Since it is possible to pass only within the range of the depth of field, it is possible to avoid photographing particles out of the depth of field and to set only the particles passing within the depth of field to be measured. . For this reason, it is possible to solve the problem of blurring of the particle image that the conventional direct imaging method has, and to measure the particle feature amount inside the dense particle group that could not be measured by the conventional direct imaging method.

  If desired, the probe portion has a bridge connecting portion that interconnects the portions of the probe portion divided by the slit, and the slit is divided into an inflow side opening and an outflow side opening by the bridging connection portion.

  Preferably, the probe unit is formed of a hollow cylinder or tube, and a photographing lens system is disposed in the cylinder or tube of the probe unit. By providing the imaging lens system in the probe unit in this way, close-up imaging can be performed on particles inside the dense particle group, and measurement with high spatial resolution can be realized.

  Preferably, the optical lens system constituting the photographing lens system includes a telecentric lens. By using the telecentric lens in this way, it is possible to always photograph the particles existing in the depth of field as the same size, so that the measurement accuracy of the size and shape of the particles can be improved.

  In a preferred embodiment of the present invention, passage opening / closing means for selectively closing the inflow side opening and the outflow side opening of the passage so as to prevent the particle group from entering the particle group passage is disposed in the probe portion. Established.

  In another preferred embodiment of the present invention, an optical path for supplying background illumination light extending along the shaft portion of the probe portion is disposed in the probe portion, and the background illumination light is probed along the axis of the shaft portion. After being guided to the distal end portion of the probe portion, irradiation is performed from the distal end portion of the probe portion toward the proximal end portion of the probe portion. Preferably, the optical path is formed by an illumination optical fiber. In this way, by providing an optical fiber for illumination in the tube or tube of the probe unit, the background illumination required in the direct imaging method is supplied by the optical fiber, and an optical path for background illumination is incorporated in the probe unit. An integral and compact particle imaging apparatus can be provided. For example, the particle imaging device of the present invention can be designed in a compact device form that can be inserted into the fluid of the particle group with one hand, so that it can be installed very easily in the fluid to be measured, The convenience can be greatly improved.

  In still another preferred embodiment of the present invention, the particle imaging apparatus includes particle group attracting means for attracting the particle group into the particle group passage. Preferably, the particle photographing device is further provided with particle discharging means for discharging particles staying or remaining in the particle group passage from the passage under pressure.

  In still another preferred embodiment of the present invention, the particle imaging apparatus further includes a passage size adjusting means that allows the passage width to be variably set. For example, the passage size adjusting means is composed of an expansion / contraction type bridging connecting portion having a slide portion, or a slide type cylindrical shutter. If desired, the particle imaging apparatus includes a locking unit or a fixing unit that fixes or releases the position of the slide unit or the shutter. According to the particle imaging apparatus provided with such a passage size adjusting means, the passage width of the particle group passage can be variably set or finely adjusted, so that the passage width is set to an optimum size corresponding to the depth of field. Can be set. Further, according to the particle imaging apparatus provided with such a passage size adjusting means, the passage width of the particle group passage can be set to an arbitrary size, so that the number of particles passing through the particle group passage is appropriately reduced. It is possible to arbitrarily set the passage width so as to increase or increase the amount.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic perspective view showing the overall configuration of the particle imaging / measurement system, and FIG. 2 is a plan view, a side view, and a front view showing the configuration of the particle imaging device shown in FIG.

  FIG. 1 shows the overall system configuration of a particle imaging / measurement system including a particle imaging apparatus according to a preferred embodiment of the present invention. The particle imaging apparatus 1 has a structure in which a measurement probe unit 1a having a background illumination function for particle imaging is integrally connected to an imaging apparatus 10 such as a digital CCD camera. The probe section 1a has a circular probe probe shape that can be inserted into the flow of the flying particle group P. The probe unit 1a includes a telecentric lens portion 2 that is integrally connected to the imaging device 10 and an adapter portion 3 that is concentrically and integrally connected to the distal end portion of the telecentric lens portion 2. Such a particle imaging apparatus 1 in the form of a probe is extremely advantageous practically because the adapter part 3 constituting the detection unit can be easily inserted into a desired position inside the flying particle group.

  The particle imaging apparatus 1 further includes a slit 4 that restricts the fluid flow path within the depth of field in order to capture the flying particle group P within the depth of field. The slit 4 is formed in the peripheral wall of the cylindrical adapter portion 3 that constitutes the photographing optical device 1. The slit 4 extends in the circumferential direction of the probe portion 1a on a surface perpendicular to the axis XX of the probe portion 1a. A through hole mechanism or a through hole mechanism penetrating the shaft portion of the probe portion 1 a is formed by the slit 4.

  The slit 4 constitutes a passage width regulating means for limiting the passage of the flying particle group P to the passage width W (FIG. 2) having a dimension corresponding to the depth of field. Passes within the depth of field. That is, the object field of the particles imaged on the imaging device 10 is limited to the passage width W of the slit 4, and the particles passing through the slit 4 are measurement targets of the particle imaging / measurement system.

  The adapter part 3 also has a diffusion plate 6 arranged at the tip of the adapter part 3. The particle imaging apparatus 1 has a configuration in which background illumination is employed as an illumination method, and an optical fiber 5 for supplying background illumination is connected to the diffuser plate 6. The optical fiber 5 and the diffusing plate 6 constitute illumination means for supplying background illumination from the distal end portion of the probe portion 1a toward the proximal end portion of the probe portion 1a.

The dimensions and performance of the particle imaging apparatus 1 are set as follows, for example.
・ Outer diameter D of probe part: 30mm
・ Probe length L: 360mm
・ Focal length: 90mm
-Magnification: 0.7X to 4.5X
・ Field of view: Minimum 2mm (4.5X magnification), Maximum 15mm (0.7X magnification)
・ Depth of field (half-open): Minimum 1mm (4.5X magnification), Maximum 12mm (0.7X magnification)

For example, the following digital CCD camera can be suitably used as the imaging device 10.
・ Product name: “jAiCV-M2CL” manufactured by JAI
Effective pixel size: 1600 (h) x 1/200 (v)
・ CCD element size: 11.84mm (h) x 8.88mm (v)
・ Number of bits: 10bit
・ Shooting speed: 30fps / dual channel

  The particle imaging / measurement system including the particle imaging device 1 includes a laser device 11, a speckle killer 12, a PC (personal computer) 13, a delay generator 14, and a function generator 15, as shown in FIG. The devices 11 to 15 constituting the particle imaging / measurement system are connected to each other via a control signal line indicated by a virtual line (a chain line), and visualize flying particles passing through the slit 4 as described later. The photographed image is stored, the photographed image is stored, and the particle feature amount (particle velocity, particle diameter, particle shape, etc.) is measured using a particle image processing algorithm.

The laser device 11 supplies illumination light (background light) for photographing, and a double pulse Nd: YAG laser (neodymium / yag laser) or the like can be used as the laser device 11. For example, the following Nd: YAG laser can be suitably used as the laser device 11.
-Product name: “Solo PIV laser” manufactured by New Wave Research
・ Maximum emission frequency: 30KHz
・ Output: 50mJ / pulse @ 532nm
・ Pulse width: 3 to 5 ns

  The speckle killer 12 is for reducing speckle noise generated by illumination of the laser device 11. If it is not necessary to reduce speckle noise, the speckle killer 12 may be omitted. As the speckle killer 12, for example, SK-11-Mg5 manufactured by Nanophoton Co., Ltd. can be suitably used.

  The PC 13 reads and stores the image data of the image taken by the imaging device 10 and saves the image data, and adjusts the length of the minute time interval of the delay generator 14. The delay generator 14 controls the pulse interval of the laser device 11. As the delay generator 14, "VSD1000" manufactured by Flotech Research, the number of output channels: 7ch can be suitably used. The function generator 15 controls the output frequency of the laser device 11 to an arbitrary frequency. As the function generator 15, for example, FG3021B manufactured by Tektronix can be suitably used.

  In use, the pulse signal of the function generator 15 is input to the delay generator 14. The delay generator 14 outputs a signal delayed by a predetermined time interval (minute time) based on the pulse signal of the function generator 15 to the laser device 11 and the imaging device 10 as a trigger signal. The laser device 11 to which the trigger signal of the delay generator 14 is input emits a single pulse laser beam or a double pulse laser beam with a predetermined delay time set. The imaging device 10 to which the trigger signal of the delay generator 14 is input captures at least one image in the particle diameter imaging or the like, and in the particle velocity measurement or the like, at least one set (2) with a minute time interval. Image). In actual measurement, multiple images or multiple sets of images are taken. Image data of an image photographed by the imaging device 10 is input to the PC 13, stored in the PC 13, and stored.

  In this embodiment, the laser device 11 that has received the trigger signal of the delay generator 14 supplies a double pulse laser to the speckle killer 12 as illumination light. The illumination light passes through the speckle killer 12, is guided to the optical fiber 5, and is supplied as background illumination light into the probe unit 1 a of the particle imaging apparatus 1 from the diffusion plate 6 disposed at the tip of the adapter part 3.

  FIG. 3 is a plan view, a side view, a transverse sectional view (II-II sectional view) and a longitudinal sectional view (II-II sectional view) showing the structure of the probe portion 1a.

  The lens 8 constituting the telecentric lens part 2 is shown in FIG. Since the telecentric lens subsystem including the lens 8 has a structure in which the working distance of the lens does not depend on the zoom magnification, the imaging device 10 can clearly photograph particles passing through the gap of the slit 4 regardless of the zoom magnification. it can. Therefore, the zoom magnification can be freely set according to the particle size.

  As shown in FIG. 3, a screw groove (inner screw) 2 a and a screw thread (outer screw) 3 a that are screwed to each other are formed in a connecting portion between the telecentric lens portion 2 and the adapter portion 3. The telecentric lens portion 2 is detachably attached to the distal end portion. In use, the screw parts are screwed or released by relative rotation of the adapter part 3 and the telecentric lens part 2, whereby the adapter part 3 is attached to the tip part of the telecentric lens part 2, or the telecentric lens part 2 It can be removed from the tip.

  The adapter part 3 also has an optical window 7 arranged between the telecentric lens part 2 and the slit 4. The optical window 7 is formed of a lens disposed between the telecentric lens portion 2 and the slit 4 and protects the telecentric lens portion 2 and prevents particles from entering the telecentric lens portion 2 side. If desired, a C cloak lens holder that facilitates installation of the optical window 7 may be provided in the adapter portion 3 and the optical window 7 may be installed in the C mount lens holder.

  Thus, in this embodiment, the optical window 7 is arranged in the adapter portion 3 in order to prevent the fluid from adhering to the lens 8 of the telecentric lens portion 2 during fluid measurement and degrading the quality of the photographed image. However, the situation in which the optical window 7 itself is contaminated by the adhesion of the fluid and the quality of the captured image is deteriorated is unavoidable. For this reason, the adapter part 3 is detachably connected to the telecentric lens part 2 as described above, and when the adapter part 3 is contaminated by fluid adhering to the adapter part 3, the adapter part 3 is removed. It can be removed and separated, and only the adapter part 3 can be cleaned.

  The slit 4 is designed as a continuous opening groove having a uniform width W extending over the entire circumference of the adapter portion 4 in a plane perpendicular to the axis XX of the shaft portion of the probe portion 1a except for the bridge connecting portion 4a. . The portion 4b of the slit 4 positioned on the upper side of the bridging connecting portion 4a forms an inflow side opening in the adapter portion 3 through which the fluid containing the flying particle group P flows into the cylindrical region (intratube region 1b) of the adapter portion 3, The portion 4c of the slit 4 located on the lower side of the bridging connecting portion 4a has an outflow side opening through which the fluid containing the flying particle group P flows out from the in-cylinder region (inside tube region 1b) of the adapter portion 3 to the outside of the cylinder. 3 to form. Therefore, a fluid flow perpendicular to the axis XX of the shaft portion of the probe portion 1a is formed in the cylindrical portion of the adapter portion 3.

  The slit 4 is further designed so that the center of the object field coincides with the center Y of the particle passage region, and the width W of the slit 4 is set to a dimension corresponding to the depth of field and the passage width of the particle passage region. Designed to regulate. That is, the slit 4 constitutes passage width regulating means for limiting or regulating the path of the flying particle group P so that the flying particle group P suspended in the fluid passes through the range of the depth of field of the particle imaging apparatus 1. To do.

  Further, in the present embodiment, the bridging connecting portion 4a is designed to have a size capable of exhibiting the minimum necessary strength for maintaining the integrity of the base portion and the tip portion of the adapter portion 3, and therefore the slit 4 is It opens over substantially the entire circumference of the probe portion 1a. For this reason, when the probe part 1a is inserted into the fluid containing the flying particle group P, the slit 4 opens at the upper and lower or left and right facing positions, and the fluid containing the flying particle group P is not hindered in flow. Smoothly circulates in the slit 4.

  The laser light irradiated by the laser device 11 (FIG. 1) is supplied as background illumination to the diffuser plate 6 via the optical fiber 5, and the background illumination light passes through the telecentric lens portion 2 and serves as a bright background for the imaging device 10. The image is formed on the image plane of the imaging device 10.

  Part of the flying particle group P passes through the slit 4. Since the slit 4 penetrates the probe unit 1a in a direction crossing the optical path of the background illumination, particles passing through the slit 4 reflect the background illumination. For this reason, the particles in the image form an image on the image plane of the imaging device 10 as a black image. Accordingly, since the particle and its background can be clearly identified on the image, the PC 13 can measure the particle size, the particle velocity, and the like using the particle image processing algorithm. The particle photographing device 1 can photograph a particle image having a comparable size regardless of the position of the particle in the depth direction within the depth of field due to the characteristics of the telecentric lens portion 2. Further, the image photographed by the imaging device 10 is stored in the PC 13.

  Thus, according to the particle imaging device 1 of the present invention, since the fluid passage position can be limited to the depth of field, it is possible to image particles without blurring the particle image. Further, according to the particle imaging apparatus 1 of the present invention, it is possible to omit the time for determining or estimating the depth of field at the time of imaging, so that particle measurement can be performed efficiently.

  FIG. 4 is a perspective view of a particle photographing apparatus showing another embodiment of the present invention. The particle imaging apparatus shown in FIG. 4 has the same basic configuration as that of the particle imaging apparatus shown in the first embodiment (FIGS. 1 to 3) except that a slit opening / closing means for selectively opening and closing the slit 4 is provided. In FIG. 4, the same reference numerals are assigned to components or components that are substantially the same as or equivalent to the components or components of the first embodiment.

  The probe unit 1a of the particle imaging apparatus 1 shown in FIG. 4 has a slit 4 that forms a particle group passage, as in the above-described embodiment, and the passage has a shaft portion that crosses the axis of the shaft portion. To penetrate. The slit 4 forms an inflow side opening 4b and an outflow side opening 4c for allowing a fluid containing the flying particle group P to flow into or out of the cylinder of the probe portion 1a, and corresponds to the depth of field. The passage width restricting means for restricting the passage width of the particle group passage to the size to be configured. The flying particle group P suspended in the fluid passes through the range of the depth of field of the imaging device 10.

  In the particle imaging device 1 shown in FIG. 4, the telecentric lens portion 2 and the adapter portion 3 are attached to a screw thread and a screw groove that are screwed together, as in the previous embodiment. The telecentric lens portion 2 is detachably attached to the distal end portion.

  When the probe part 1a is inserted into the fluid containing the flying particle group P to be measured and the characteristics of the fluid are measured, the fluid flows into the apparatus 1 from the inflow side opening 4b of the slit 4.

  When the inflowing fluid adheres to the lens of the telecentric lens portion 2 and the lens is contaminated, it becomes difficult to capture an image, or the image quality of the captured image is deteriorated, resulting in a situation that is difficult to analyze. An optical window 7 is disposed between the slit 4 and the telecentric lens portion 2 in order to prevent such troubles due to adhesion of contaminants. The particle imaging apparatus 1 of the present embodiment has such an optical system. In order to minimize the frequency or chance of contamination of the window 7, a cylindrical slide opening / closing shutter 20 that can selectively open and close the slit 4 is further provided.

  The shutter 20 is attached to the outside of the probe unit 1a so as to be slidable in the axial direction of the particle imaging apparatus 1 as indicated by arrows in FIGS. 4 (A) and 4 (B). FIG. 4A shows a state in which the shutter 20 is displaced to the proximal end side of the probe portion 1a and the slit 4 is held in an open state. In this state, the particle imaging device 1 performs particle imaging and particle feature amount measurement. FIG. 4B shows a state in which the shutter 20 is displaced toward the distal end side of the probe portion 1a and the slit 4 is held in a closed state. The shutter 20 prevents the fluid containing the flying particle group P from flowing into the slit 4.

  According to the particle imaging apparatus 1 having such a passage opening opening / closing means (shutter 20), the following advantages are obtained.

(1) The shutter 20 is moved to the closed position as shown by an arrow in FIG. 4A at the time before the measurement is executed in the preparation process before the start of measurement, at the time of long-term measurement interruption or at the end of the measurement. Therefore, it is possible to reliably prevent the fluid from flowing into the slit 4, thereby preventing contamination in the probe 1 a and reducing or reducing time, labor, labor, etc. required for maintenance such as cleaning of the particle imaging apparatus 1. be able to.

(2) When the measurement is transiently interrupted for various adjustments of the particle imaging apparatus 1, if the slit 4 is left open during the adjustment time, the fluid flowing into the slit 4 causes the inside of the probe unit 1a. However, the slit 20 can be easily closed by the shutter 20 to reliably prevent contamination in the probe portion 1a.

(3) In the first embodiment, after the adapter part 3 is removed from the telecentric lens part 2 and cleaned or washed, it is necessary to attach the adapter part 3 to the telecentric lens part 2 again. Although there is a concern that the measurement setting position slightly changes, the contamination of the probe portion is prevented by the shutter 20, thereby greatly increasing the frequency of such attachment / detachment / cleaning / re-adjustment of the adapter portion 3. Can be reduced.

  In the present embodiment, the slide opening / closing shutter 20 is attached to the outside of the probe unit 1a as the passage opening opening / closing means. However, the slide opening / closing shutter is disposed inside the probe unit 1a, or In addition, an opening / closing means having another structure such as a rotary opening / closing door or a shutter may be disposed inside or outside the probe unit 1a.

  FIG. 5 is a plan view, a side view, a transverse sectional view, and a longitudinal sectional view showing the structure of a probe portion 1a according to still another embodiment of the present invention. The configuration of the particle imaging apparatus according to the present embodiment is the same as the configuration of the particle imaging apparatus of the first embodiment (FIGS. 1 to 3) except for the optical fiber path. Components or components that are substantially the same or equivalent to each other are denoted by the same reference numerals.

  As shown in FIG. 5, in the particle imaging apparatus 1 of the present embodiment, the optical fiber 5 for background illumination penetrates the inside of the imaging optical apparatus 1 and once out of the apparatus 1 from the tip of the adapter portion 3 ( It is folded after projecting to the other side, and connected to the central part of the diffuser plate 6 and, as in the previous embodiment, irradiates background illumination light from the distal end of the probe 1a toward the proximal end of the probe 1a. To do.

  According to such a configuration, it is possible to provide a compact and integral particle imaging apparatus 1 in which the optical path of background illumination light is incorporated in the probe unit 1a.

  6 (A) and 7 (A) are longitudinal sectional views showing the structure of a probe portion 1a according to another embodiment of the present invention. 6B and 6C are cross-sectional views taken along lines III-III and IV-IV in FIG. 7B and 7C are cross-sectional views taken along lines VV and VI-VI in FIG. The configuration of the particle imaging apparatus according to the present embodiment is the same as that of the first embodiment (FIGS. 1 to 3) except that the particle imaging apparatus includes particle group attracting means that reliably causes the flying particle group P to flow into the slit 4. Constituent elements or constituent parts that are substantially the same as or equivalent to the constituent elements or constituent parts of the first embodiment are denoted by the same reference numerals.

  The particle imaging apparatus 1 of the present embodiment includes a particle attracting device 30 having a substantially semicircular cross section that covers the lower half of the slit 4 positioned below the bridging connecting portion 4 a, that is, the outflow side opening 4 c of the slit 4. . The particle attracting device 30 includes a semicircular attracting jacket portion 31 having an outer diameter larger than the outer diameter of the probe portion 1a, an end plate portion 32 that closes the distal end portion of the outer cylinder portion 31, and the attracting jacket portion 31 and the end. It comprises a particle attraction channel 34 defined by the plate portion 32, a suction line 35 communicating with the particle attraction path 34, and a suction device 36 such as a suction pump and a blower connected to the suction line 35. The In this embodiment, a particle discharge hole 9 for discharging particles E staying or remaining in the probe portion 1a is formed in the outer peripheral wall of the probe portion 1a. Is further provided with a discharge hole opening / closing shutter 33 capable of selectively opening and closing.

  The particle attracting device 30 includes a measurement position where the attracting jacket portion 31 and the end plate portion 32 have moved forward as shown in FIG. 6A, and the attracting jacket portion 31 and the end plate portion as shown in FIG. 32 is attached to the probe unit 1a so as to slide in the direction of the axis XX of the probe unit 1a between the retracted position moved rearward.

  At the measurement position (FIG. 6), the particle attraction channel 34 completely surrounds the slit 4, and the particle attraction channel 34 communicates with the in-tube region 1b of the probe portion 1a through the outflow side opening 4c of the slit 4. . When the suction device 36 is operated, the pressure in the particle attracting flow path 34 is reduced by the suction action of the suction device 36. As a result, the probe portion 1a passes through the inflow side opening 4b of the slit 4 located above the bridging connecting portion 4a. A pressure gradient is generated that attracts the fluid in the upper region to the in-tube region 1b. The flying particle group P approaching the upper part of the probe unit 1a smoothly flows into the inflow side opening 4b of the slit 4 due to this pressure gradient, and flows out to the particle attraction channel 34 through the outflow side opening 4c of the slit 4. As described above, the imaging device 10 images particles passing through the slit 4, and the PC 13 measures the particle feature amount using a particle image processing algorithm.

  Thus, according to the particle imaging device 1 configured to actively attract the flying particle group P into the slit 4 by the particle attracting device 30, the particle attracting device 30 enters the slit 4 due to the flow path resistance of the slit 4. Even fine particles that are difficult to flow in or particles that are difficult to flow into the slit 4 due to various conditions such as temperature distribution, pressure distribution, air flow, etc. of the particle flight environment, pass through the slit 4 smoothly. Therefore, it is possible to reliably image such particles and measure the particle feature amount.

  Furthermore, according to the particle imaging apparatus 1 having such a particle attracting apparatus 30, it is possible to positively attract and image the particle group suspended in the stationary fluid into the slit 4 and measure the particle feature amount. It becomes possible.

  In addition, a part of the flying particle group P that has flowed into the slit 4 may stay in the in-pipe region 1b as residual particles E without flowing out into the particle attracting flow path 34. Then, the particle discharge hole 9 is closed by the discharge hole opening / closing shutter 33. For this reason, the residual particles E remain at the bottom of the in-tube region 1b as shown in FIGS. 6 (A) and 6 (C).

  When the particle attracting device 30 moves to the retracted position (FIG. 7), the particle attracting flow path 34 is separated from the slit 4, and the outflow side opening 4c of the slit 4 is opened downward. The hole 9 is opened, and the particle attraction channel 34 communicates with the in-tube region 1b through the particle discharge hole 9. When the suction device 36 is operated in this state, the pressure in the particle attraction channel 34 is reduced, and the residual particles E in the in-pipe region 1b flow out from the particle discharge hole 9 to the particle attraction channel 34 and are captured by the suction device 36. Captured by means (not shown).

  Therefore, according to the particle imaging device 1 provided with such a particle attracting device 30, the residual particles E in the in-tube region 1b can be positively discharged and the in-tube region 1b can be easily cleaned.

  FIG. 8 and FIG. 9 are cross-sectional views showing an embodiment of a particle imaging apparatus provided with passage size adjusting means. 8 (A) and 8 (B) are cross-sectional views showing the structure of the probe portion 1a having the stretchable bridging connecting portion 4a, and FIG. 8 (C) is a cross-sectional view taken along line VII- of FIG. 8 (B). It is sectional drawing in the VII line. FIG. 9 is a longitudinal sectional view showing a probe unit 1a having a sliding cylindrical shutter 50 similar to the shutter 20 shown in FIG. In the drawings, the same reference numerals are assigned to the components or components that are substantially the same as or equivalent to the components or components of the above-described embodiments.

  The width W of the slit 4 is set to a dimension corresponding to the depth of field. However, in actual particle measurement, it is desirable that the dimension be a numerical value that necessarily matches the dimension value of the depth of field. In many cases, it is desirable that the numerical value is slightly smaller than the dimension value of the depth of field. This is due to the fact that particles of various sizes are mixed in an actual particle group, and that the actual depth of field in actual particle photography has a relationship depending on the particle diameter.

  In addition, when the probe unit 1a is inserted into a gas or liquid in which fine particle groups are densely dispersed and flying, an excessive amount of fine particles may flow into the slit 4, and in such a case, it flows into the slit 4. It is desirable to limit the amount of fine particles and adjust it to an amount suitable for photographing. In consideration of such circumstances, the particle imaging apparatus 1 shown in FIGS. 8 and 9 includes a passage size adjusting unit that can variably set the flow rate of the fluid including the fine particle group through the slit.

  The passage size adjusting means shown in FIG. 8 has a rectangular cross-section slide portion 40 formed of an extension of the bridge connecting portion 4a, and a rectangular cross-section groove that receives the slide portion 40 and supports the slide portion 40 so as to be slidable or slidable. 41. The slide part 40 and the groove 41 extend in parallel with the axis XX. FIG. 8A shows a state in which the slide portion 40 is completely drawn into the groove 41. In this state, the length of the bridge connecting portion 4a is the shortest, and the width W of the slit 4 is set to the minimum dimension. FIG. 8B shows a state in which the slide portion 40 is appropriately protruded from the groove 41. In this state, the bridge connecting portion 4a is extended, and the width W of the slit 4 is set to an enlarged dimension. In addition, the probe part 1a has the latching means or fixing means (not shown) which selectively fixes or releases the position of the slide part 40.

  The passage size adjusting means shown in FIG. 9 includes a sliding cylindrical shutter 50 similar to the shutter 20 shown in FIG. The shutter 50 is supported on the outer periphery of the probe portion 1a so as to be slidable in parallel with the axis XX. FIG. 9A shows a state where the shutter 50 is completely retracted and the slit 4 is completely opened. The width W of the slit 4 has the maximum dimension in this state. FIG. 9B shows a state in which the shutter 50 is appropriately advanced and the slit 4 is partially closed. In this state, the width W of the slit 4 is set to a reduced size. The probe unit 1a includes a locking unit or a fixing unit (not shown) that selectively fixes or releases the position of the shutter 50.

  According to the particle photographing apparatus 1 provided with the passage size adjusting means as shown in FIGS. 8 and 9, the width W of the slit 4 can be variably set, so that the slit has an optimum dimension corresponding to the depth of field. The width W of 4 can be set as appropriate. Further, according to the particle photographing apparatus 1 provided with such a passage size adjusting means, when an excessive amount of particles flows into the slit 4, the width W of the slit 4 is reduced, and conversely, the slit 4 When the amount of particles flowing into the inside is too small, it is possible to set an arbitrary passage size such as expanding the width W of the slit 4, so that the application range or application range of particle photography is greatly expanded. Let's go.

  The preferred embodiments and examples of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments and examples, and is within the scope of the present invention described in the claims. Various modifications or changes are possible.

  For example, the mechanical configuration, cross-sectional structure, dimensions, shape, form, and the like of the probe portion can be changed in design according to the present invention.

  In addition, the configuration and the like of the particle imaging / measurement system to which the particle imaging apparatus is connected can be arbitrarily changed in design within the scope of the object of the present invention.

  Furthermore, in each of the above-described embodiments, the particle imaging apparatus has a configuration in which a diffusion plate for improving the energy distribution of the laser is disposed at the tip of the adapter portion, but the installation of the diffusion plate is omitted if desired. Is also possible.

  In each of the above-described embodiments, the adapter portion is screw-connected to the telecentric lens portion. However, the adapter portion is connected to the telecentric lens portion by other engaging or disengaging means that can be engaged and disengaged. You may do it.

  Further, each of the above-mentioned embodiments has a structure in which the cross-linking connection portions having a square cross section are arranged in pairs at symmetrical positions, but the position, form, number, etc. of the cross-linking connection portions are arbitrarily changed in design. It is possible.

  The present invention relates to a technique for measuring particle feature quantities such as particle number density, particle velocity, particle diameter, particle shape and the like in a group of fine particles dispersed and flying in a gas or liquid, and is provided with diesel exhaust, boiler exhaust, and pulverized coal. It can be applied to many fields as a basic measurement technique in a wide range of fields such as combustion, fuel spray, cleaning spray, spray coating, spray coating, powder transportation, and agricultural chemical application. The application of such basic measurement technology is expected to maintain and strengthen the technological capabilities in the existing industrial field, thereby supporting the creation of new industries.

  For example, in electrostatic coating in the automobile industry, the characteristics of fine particle groups are deeply related to product quality, but the quantification of the characteristics has not been achieved, and there is a situation that depends on the experience and intuition of skilled engineers. If the particle group behavior is measured by the practical application of the present invention, and the relationship between the coating appearance and the particle characteristics can be quantified, for example, the possibility of tailored coating according to the purchaser's preference, etc. It is expected that new industries and new businesses will be created. Therefore, the practical effect of the present invention is remarkable.

DESCRIPTION OF SYMBOLS 1 Particle imaging device 1a Probe part 1b In-pipe area | region 2 Telecentric lens part 3 Adapter part 4 Slit 4a Bridge | crosslinking connection part 4b Inflow side opening 4c Outflow side opening 5 Optical fiber 6 Diffusion plate 7 Optical window 8 Lens 9 Particle discharge hole 10 Imaging apparatus 11 Laser equipment 12 Speckle killer 13 PC (personal computer)
14 Delay Generator 15 Function Generator 20 Slide Open / Close Shutter 30 Particle Attracting Device 40 Slide Part 41 Groove 50 Slide Type Cylindrical Shutter

Claims (11)

In a particle imaging device for measuring particle feature quantities,
A probe unit inserted into a fluid containing suspended particles or flying particles; and
An imaging device that images the particles of the particle group via an optical path formed in an axial core portion of the probe unit;
Illuminating means for supplying background illumination from the distal end portion of the probe portion toward the proximal end portion of the probe portion;
The shaft portion of the probe portion is open to the outer surface of the probe portion, and the passage of the particle group penetrating the shaft portion in a direction transverse to the axis of the shaft portion; A particle photographing apparatus comprising: passage width restricting means for restricting the passage width of the particle group passage to a size corresponding to the depth of field so as to pass through the range of the depth of field.   The passage width restricting means includes a slit extending in the circumferential direction of the shaft portion, and the slit includes an inflow side opening and an outflow side for allowing the fluid to flow into or out of the particle group passage. The particle imaging apparatus according to claim 1, wherein an opening is formed.   The particle imaging apparatus according to claim 2, wherein the slit has a substantially uniform width, and a flow path formed by the slit extends in a direction perpendicular to the axis of the shaft portion.   4. The particle imaging apparatus according to claim 3, wherein a center line of the slit is positioned in a plane perpendicular to the axis of the shaft portion and including a focal point of the particle imaging apparatus.   The particle imaging apparatus according to any one of claims 1 to 4, further comprising passage size adjusting means for variably setting the passage width.   The particle imaging apparatus according to claim 1, wherein the probe unit is formed of a hollow cylinder or a tube.   The passage opening and closing means for opening and closing the inflow side opening and the outflow side opening of the passage so as to prevent the particle group from entering the passage. The particle imaging apparatus according to 1.   An optical path for supplying background illumination light extending along the shaft portion of the probe portion is provided in the probe portion, and after the background illumination light is guided to the distal end portion of the probe portion along the axis of the shaft portion, The particle imaging apparatus according to claim 1, wherein irradiation is performed from a distal end portion of the probe portion toward a proximal end portion of the probe portion.   The particle photographing apparatus according to claim 1, further comprising a particle group attracting unit that attracts the particle group into the passage.   The particle imaging apparatus according to any one of claims 1 to 9, further comprising particle discharging means for discharging particles staying or remaining in the passage from the passage under pressure.   A particle imaging / measurement system comprising: the particle imaging apparatus according to any one of claims 1 to 10; and a measuring unit that stores a captured image and that measures a particle feature amount using a particle image processing unit. .

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