JP6030353B2 - Particle collection device and particle detection device having the same - Google Patents

Description

  The present invention relates to a particle detection apparatus for detecting biological particles.

  2. Description of the Related Art There is known a particle collecting apparatus that applies a high voltage between a needle electrode and a flat plate electrode arranged to face the needle electrode and collects particles in the air on the flat plate electrode.

  Also, negative ion generators that generate negative ions are known. For example, Patent Document 1 describes a negative ion generator that can prevent a negative ion from being filled near an electrode and generating no negative ion without providing a blower for removing the filled negative ion. Yes. The negative ion generator described in Patent Document 1 includes an insulating duct-like structure surrounding a high-voltage electrode that emits electrons, and includes means for grounding the duct-like structure. By grounding the insulating duct-like structure surrounding the high-voltage electrode, negative ions attached to the duct-like structure will be released to the ground. A stable discharge is performed.

JP 2002-324651 A (published on November 8, 2002)

  However, since the technique of Patent Document 1 is a negative ion generator and not a particle collecting apparatus having a counter electrode, it is not possible to directly apply a technique for preventing a decrease in discharge capacity. That is, in the particle collecting apparatus, the structure of the insulating casing that includes the counter electrode and surrounds the high-voltage electrode becomes complicated. Therefore, it is not possible to prevent the discharge capacity from being lowered simply by connecting the duct structure to a means for grounding, such as a duct-like structure in the negative ion generator. The position where the casing is connected to the grounding means is important, and it is important to connect the grounding means to the part that causes the discharge capacity to be lowered by electrification. Of course, by providing conductivity to the entire casing, it is possible to efficiently release the charge of the entire casing and suppress a decrease in discharge capability, but it cannot be denied that the cost is increased.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a particle collection device capable of stabilizing discharge capability by an inexpensive method and a particle detection device including the particle collection device. It is to be.

  In order to solve the above problems, the particle collecting apparatus of the present invention charges particles between a high-voltage electrode and a collecting electrode provided at a position facing the high-voltage electrode, and collects the particles. A particle collecting device for collecting particles on an electrode, the first insulating structure containing the high-voltage electrode and the collecting electrode, and the outer surface of the first insulating structure And a conductive member provided on a surface located in the vicinity of the high voltage electrode, and a grounding means for grounding the conductive member.

  When the particles are charged, the insulating first structure is also negatively charged, and the high voltage electrode is difficult to discharge. However, according to the above configuration, the conductive member is provided on the outer surface of the insulating first structure and located in the vicinity of the high voltage electrode. In FIG. 5, the charge in the vicinity of the high voltage electrode can be released to the grounding means. Thereby, it is possible to prevent the discharge capability of the high-voltage electrode from deteriorating without losing the charge of the entire insulating first structure. Therefore, it is possible to provide a particle detection device that can stabilize the discharge capacity by an inexpensive method.

  In the particle collecting apparatus of the present invention, the means for grounding the conductive first structure is an FPC cable.

  In the particle collecting apparatus of the present invention, the high voltage electrode has a needle shape.

  The particle collection device of the present invention further includes a suction member that forms an air flow in a direction opposite to the collection electrode, and the conductive member interferes with the air flow formed by the suction member. It is provided in a position that does not.

  According to said structure, it can prevent that particle | grains are collected besides a collection electrode.

  The particle collecting apparatus of the present invention further includes an insulating second structure enclosed in the insulating first structure, and the insulating second structure is a hollow having openings at both ends. One of the openings at both ends faces the collecting electrode, and the insulating second structure encloses at least a part of the high-voltage electrode. Specifically, the insulating second structure has a through-opening other than the openings at both ends, and the high voltage electrode is in a non-contact state with the insulating second structure, The through opening is penetrated from the outside to the inside.

  According to the above configuration, since the high voltage electrode penetrates without contacting the insulating second structure, electric charges are accumulated in the insulating second structure, and the surface potential is prevented from increasing. can do. Thereby, the discharge stability and discharge capability of the high voltage electrode can be improved.

  In the particle collecting apparatus of the present invention, the high voltage electrode is covered with a coating material having a dielectric constant higher than that of the insulating second structure except for the tip.

  According to said structure, since the electric charge which generate | occur | produced with the high voltage electrode is hold | maintained by the coating | coated member instead of an insulating 2nd structure, the discharge stability of a high voltage electrode can be improved further.

  The present invention has an effect that the discharge capacity can be stabilized by an inexpensive method.

It is a figure which shows the change of the fluorescence intensity of the particle | grains in the air before and behind a heating. It is a figure which shows an example of a collection process. It is a figure which shows an example of the fluorescence measurement process before a heating. It is a figure which shows an example of a heating / cooling process. It is a figure which shows an example of the fluorescence measurement process after a heating. It is a figure which shows an example of a refresh process. It is a graph which shows the relationship between increase amount (DELTA) F of the fluorescence intensity before and behind a heating, and the particle | grain density | concentration of biological origin. It is a figure which shows the principal part structure of the particle | grain detection apparatus in 1st Embodiment. It is the figure which showed simply the particle | grain detection apparatus in 1st Embodiment. It is a simple figure which shows the state which has arrange | positioned the electroconductive member on the housing | casing surface. It is a figure which shows the relationship between the position of an electroconductive member, and a discharge current. It is a figure which shows an example of the particle | grain detection apparatus in 2nd Embodiment. It is a figure for demonstrating the difference between the suction cylinder in 1st Embodiment, and the suction cylinder in 2nd Embodiment. It is a figure which shows the overlap of a needle electrode and a collection board | substrate in the state planarly viewed, and the distance of a needle electrode and a collection board | substrate. It is a figure which shows a measurement result. It is a figure which shows an example of the particle | grain detection apparatus in 3rd Embodiment.

  Embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  A particle detection device equipped with the particle collection device of the present embodiment is a device for detecting particles derived from organisms such as pollen, microorganisms, and molds. First, the principle of detecting biological particles using the particle detection apparatus according to the present embodiment will be described.

  FIG. 1 is a diagram showing changes in fluorescence intensity of particles in the air before and after heating. FIG. 1 (a) shows the measurement object as biological particles, and FIG. 1 (b) shows the measurement object as dust.

  When the biological particles floating in the air are irradiated with ultraviolet light or blue light, the biological particles emit fluorescence. However, particles of chemical fiber dust or the like (hereinafter also referred to as dust) are also floating in the air, and fluoresce in the same manner as biologically derived particles. For this reason, it cannot be distinguished whether it is from the particle | grains derived from a living organism | raw_food, or dust only by detecting fluorescence.

  1A and 1B show the results of measuring the change in fluorescence intensity (fluorescence amount) before and after heating by subjecting the biological particles and dust to heat treatment. The dotted line shown in FIG. 1 (a) shows the change in the fluorescence intensity (fluorescence amount) of the biological particle before heating, and the solid line shows the change in the fluorescent intensity of the biological particle after heating. The dotted line shown in FIG. 1B shows the change in the fluorescence intensity of the dust before heating, and the solid line shows the change in the fluorescence intensity of the dust after heating.

  As shown in FIGS. 1A and 1B, the fluorescence intensity emitted from the dust does not change by the heat treatment, whereas the fluorescence intensity emitted from the biological particles increases by the heat treatment. For this reason, in the particle detector in the present embodiment, the amount of biological particles is determined by measuring the fluorescence intensity before and after heating for particles in which biological particles and dust are mixed, and obtaining the difference therebetween. Is identified.

  FIG. 2 to FIG. 6 are diagrams showing a process for detecting biological particles. First, as shown in FIG. 2, a collection step of collecting the particles 40 on the collection substrate (collection electrode) 11 is executed. In the collection step, the high voltage generation circuit 13 applies a high voltage to the needle electrode (high voltage electrode) 12, thereby generating a potential difference between the collection substrate 11 connected to the ground and the needle electrode 12.

  At this time, when air is introduced toward the collection substrate 11 by the rotation of the fan (suction member) 17, the particles 40 floating in the air are charged around the needle electrode 12. The charged particles 40 are adsorbed on the surface of the collection substrate 11 by electrostatic force. The particles 40 adsorbed on the collection substrate 11 include biological-derived particles 40A and dust 40B such as chemical fiber dust.

  Next, as shown in FIG. 3, a fluorescence measurement step before heating for measuring the intensity of fluorescence emitted from the particles 40 before heating is executed. In the fluorescence measurement step before heating, first, the collection substrate 11 is moved to the detection position by a moving mechanism (not shown). Then, excitation light is irradiated from the light emitting element 21 toward the particles 40 collected on the collection substrate 11, and fluorescence emitted from the particles 40 by irradiation of the excitation light is received by the light receiving element 24 through the Fresnel lens 25. .

  Next, as shown in FIG. 4, a heating / cooling process for heating and cooling the particles 40 is performed. In the heating / cooling step, the position of the collection substrate 11 is returned to the position at the time of the collection step (hereinafter referred to as “collection / heating position”) by the moving mechanism, and the heater 19 is used to pass the collection substrate 11 through the collection substrate 11. The particles 40 are heated. After the heating, the particles 40 on the collection substrate 11 are cooled by the rotation of the fan 17.

  Next, as shown in FIG. 5, the post-heating fluorescence measurement step of measuring the intensity of the fluorescence emitted from the heated particles 40 is performed again by moving the collection substrate 11 to the detection position. The fluorescence measurement process after heating is the same as the fluorescence measurement process before heating. As described above, the fluorescence intensity of the fluorescence emitted from the dust 40B is not changed by the heat treatment, whereas the fluorescence intensity of the fluorescence emitted from the biological particle 40A is increased by the heat treatment. For this reason, in this step, the fluorescence intensity having a value larger than the fluorescence intensity measured in the fluorescence measurement step before heating (see FIG. 3) is measured for the biological particle 40A. Thereby, it is possible to specify the biological particle 40A.

  FIG. 7 is a graph showing the relationship between the fluorescence intensity increase ΔF before and after heating and the concentration of biological particles. With reference to FIG. 7, the increase amount ΔF1 of the fluorescence intensity is calculated from the difference between the fluorescence intensity before heating and the fluorescence intensity after heating. Based on the relationship between the fluorescence intensity increase amount ΔF prepared in advance and the biological particle concentration N, the biological particle concentration N1 corresponding to the calculated increase amount ΔF1 is specified. The correspondence relationship between the increase amount ΔF and the biological particle concentration N is experimentally determined in advance.

  Next, as shown in FIG. 6, the collection substrate 11 is moved again to the collection / heating position, and a refresh process is performed to remove the particles 40 that have finished the fluorescence measurement process after heating from the collection substrate 11. To do. In the refresh process, the collection substrate 11 is vibrated by the ultrasonic transducer 20 to be moved from the collection substrate 11. Note that the refreshing step may be performed at a third position different from the collection / heating position and the detection position instead of being performed at the collection / heating position.

[Configuration of particle detector]
Next, the structure of the particle | grain detection apparatus in this Embodiment is demonstrated based on FIG. FIG. 8 is a diagram illustrating a main configuration of the particle detection apparatus according to the first embodiment.

  As shown in FIG. 8, the particle detection device 1 includes a collection substrate 11, a collection unit 14, a fan 17, a cylindrical suction cylinder (insulating second structure) 18, a heater 19, and an ultrasonic transducer 20. Includes a housing (insulating first structure) 29 provided inside, a conductive member 30 attached to the outside of the housing 29, and a fluorescence detection unit 27. Here, the particle collecting apparatus includes the collection substrate 11, the collection unit 14, the fan 17, the cylindrical suction cylinder 18, the heater 19, the ultrasonic transducer 20, the housing 29, and the conductive member 30. . Moreover, although the particle | grain detection apparatus 1 may be provided with said moving mechanism, since it is not related to the feature point of invention, the said member is not illustrated.

  In addition, the particle | grain detection apparatus 1 in this Embodiment may be used as an apparatus single unit for detecting the particle 40A derived from living organisms, or an air cleaner, an air conditioner, a humidifier, a dehumidifier, a vacuum cleaner, You may incorporate in household appliances, such as a refrigerator and a television.

  The collection substrate 11 is provided as a collection member for collecting particles 40 in which biological particles 40A and dust 40B such as chemical fiber dust are mixed. The collection board | substrate 11 is comprised from the glass plate and the electroconductive transparent film formed in the surface of a glass plate, and is connected to earth | ground.

  The shape of the glass plate is not particularly limited, but may be any shape as long as it has an area enough to collect the particles 40. Moreover, the film formed on the surface of the glass substrate is not limited to the transparent film, and may be a metal film made of ceramic or the like, for example. Moreover, the collection board | substrate 11 may be comprised with the metal. In this case, it is not necessary to form a film.

  The collection substrate 11 is moved between the collection / heating position and the detection position by a moving mechanism (not shown).

  The collection part 14 performs a collection process (refer FIG. 2), and collects the particle | grains 40 contained in the air on the collection board | substrate 11. FIG. The collection unit 14 includes a high voltage generation circuit 13 as a power supply unit and a needle electrode 12 as a discharge electrode.

  The high voltage generation circuit 13 is disposed between the insulating casing 29 and the insulating suction cylinder 18 and is electrically connected to the needle electrode 12. The needle electrode 12 is a needle-shaped electrode and penetrates from the outside of the side surface of the suction cylinder 18 to reach the inside of the suction cylinder 18. The high voltage generation circuit 13 applies a high voltage to the needle electrode 12. Thereby, electrons are emitted from the needle electrode 12, and the emitted electrons collide with oxygen molecules and water molecules in the air, thereby generating negative ions. As a result, negative ions generated in the air adhere to the floating particles 40, and the particles are negatively charged. The charged particles 40 are attracted to the film of the collection substrate 11 connected to the ground, and adhere to the collection substrate 11.

  The fan 17 is provided in an opening formed in the lower portion of the housing 29 and can be rotationally driven in the forward direction and the reverse direction. The fan 17 forms an air flow between the inside and the outside of the apparatus by its rotation. The fan 17 is driven in the reverse direction during the collection process. When the fan 17 is driven in the reverse direction, air outside the particle detection device 1 is introduced into the particle detection device 1 through an opening formed in the upper portion of the housing 29. Thereby, the air containing the particles 40 is introduced into the suction cylinder 18.

  The fan 17 is driven in the normal rotation direction during the refresh process. When the fan 17 is driven in the forward rotation direction, the air inside the particle detection device 1 is discharged to the outside of the particle detection device 1 through the fan 17. Thereby, the particles 40 that have finished detecting the biologically derived particles 40 </ b> A are removed from the collection substrate 11.

  The suction cylinder 18 is provided in a position where the upper part of the cylinder is located in the opening of the upper part of the housing 29 and the lower part of the cylinder is opposed to the collection substrate 11. For this reason, the air introduced into the apparatus by the fan 17 being driven in the reverse direction during the collection step is guided toward the collection substrate 11. Therefore, the charged particles 40 can be easily adsorbed on the collection substrate 11.

  The heater 19 is provided on the back surface of the collection substrate 11 and heats the particles 40 collected on the collection substrate 11 during the heating / cooling step (see FIG. 4). The collection substrate 11 heated by the heater 19 is cooled by air introduced into the suction cylinder 18 by the fan 17.

  The heater 19 is moved between the collection / heating position and the detection position by a moving mechanism (not shown) together with the collection substrate 11.

  The ultrasonic transducer 20 is, for example, a small motor or the like, and is provided on the back surface of the collection substrate 11. The ultrasonic transducer 20 vibrates the collection substrate 11 by driving. By vibrating the collection substrate 11, the particles 40 collected on the collection substrate 11 are floated and the particles 40 are moved.

  Further, the ultrasonic transducer 20 can be switched to any one of a plurality of vibration modes having different vibration patterns. The ultrasonic transducer 20 changes at least one of the direction of transporting the particles 40 on the collection substrate 11 and the selection of the transported particles 40 by appropriately switching the vibration mode. Here, the particles 40 are sorted based on their weight and size (contact area). For example, pollen and dust are separated on the collection substrate 11 by vibration. Therefore, it is possible to collect predetermined particles in a predetermined region and to measure the particle amount of the predetermined particles. For example, by collecting particles having a weight and size of pollen in a predetermined region, it is possible to eliminate the influence of other particles and obtain an accurate amount of pollen.

  Further, the ultrasonic transducer 20 is moved between the collection / heating position and the detection position by a moving mechanism (not shown) together with the collection substrate 11.

  In addition, although the case where the ultrasonic transducer | vibrator 20 was provided in the back surface of the collection board | substrate 11 was demonstrated to the example here, it is not limited to the position. The ultrasonic transducer 20 may be disposed at any position as long as the collection substrate 11 can be vibrated to remove the particles 40 or to select the particles 40. For example, the ultrasonic transducer 20 may be disposed below the heater 19 shown in FIG. 8 (on the side opposite to the bonding surface with the collection substrate 11). A plurality of ultrasonic transducers 20 may be provided.

  The fluorescence detection unit 27 executes a fluorescence measurement process before and after heating, and includes an excitation light source unit 23 and a light receiving unit 26. The excitation light source unit 23 irradiates excitation light toward the particles 40 collected in a predetermined region of the collection substrate 11 by the ultrasonic transducer 20. The light receiving unit 26 receives fluorescence emitted from the particles 40 as the excitation light source unit 23 irradiates the excitation light.

  The excitation light source unit 23 includes a light emitting element 21 and a condenser lens 22 as light sources. As the light emitting element 21, a semiconductor laser, an LED (Light Emitting Diode) element, or the like is used. The light emitted from the light emitting element 21 may have a wavelength in either the ultraviolet or visible region as long as it excites the biological particles 40A to emit fluorescence.

  The light receiving unit 26 includes a light receiving element 24 and a Fresnel lens 25. As the light receiving element 24, a photodiode or an image sensor is used.

  It should be noted that the light intensity can be increased by narrowing the excitation light irradiated to the particles 40 collected in a predetermined region on the collection substrate 11 by the condensing lens 22 by the vibration of the ultrasonic vibrator 20. Good. Thereby, even if it is the same size of the collection board | substrate 11, a highly sensitive measurement is attained.

  The conductive member 30 is provided in the vicinity of the needle electrode 12 on the outside of the housing 29 and connected to the ground. As described above, when the high voltage generation circuit 13 applies a high voltage to the needle electrode 12, the needle electrode 12 is discharged and negative ions are generated. The negative ions adhere to the particles 40 in the air and are charged negatively, thereby collecting the particles 40 on the collection substrate 11, but also adhere to the housing 29 and make the housing 29 negative. It will be charged. When the housing 29 is negatively charged, the inside of the housing 29 is filled with negative ions, and the needle electrode 12 is difficult to discharge, but the conductive member 30 is provided in the housing 29 in the vicinity of the needle electrode 12. Therefore, the electric charge in the part near the needle electrode 12 in the housing 29 can be released to the ground. Thus, even if the electric charge of the entire housing 29 is not released, it is possible to effectively prevent the discharge capacity of the needle electrode 12 from being lowered by releasing the electric charge in the vicinity of the needle electrode 12 in the housing 29. it can. Further, the position where the conductive member 30 is provided is a position that does not interfere with the air flow formed by the fan 17. For this reason, the housing | casing 29 in which the electroconductive member 30 is provided functions like the collection board | substrate 11, and it can prevent that the particle | grains 40 are collected by the inner wall of the housing | casing 29. FIG. Note that an FPC cable (grounding means) can be used to connect the conductive member 30 to the ground.

  FIG. 9 is a diagram simply showing the particle detection apparatus according to the first embodiment. FIG. 9A is a perspective view of the particle detection device, and FIG. 9B is a top view of the particle detection device. Here, for convenience, symbols A to H are attached to the vertices of the casing 29 provided in the particle detection device 1.

  As shown in FIGS. 9A and 9B, the high voltage generation circuit 13 is located in the vicinity of the vertex A of the housing 29. Further, the needle electrode 12 extends from the high voltage generation circuit 13 to a position where the vicinity of the tip thereof faces the collection substrate 11 and the opening of the housing 29. The collection substrate 11 is provided on the surface EFGH of the housing 29 and in the vicinity of the side FG, and the upper opening of the housing 29 is formed on the surface ABCD and in the vicinity of the side BC. .

  FIG. 10 is a simple diagram showing a state where the conductive member is arranged on the surface of the casing. The position where the conductive member 30 is disposed on the surface of the housing 29 is different in each of FIGS. In addition, the arrangement | positioning position inside the particle | grain detection apparatus 1 shown by (1)-(8) of FIG. 10 is as having shown in FIG.

  FIG. 10 (1) shows a state in which the conductive member 30 is arranged on the side AD side of the casing 29 in the periphery of the opening at the top of the casing 29. FIG. 10B shows a state in which the conductive member 30 is arranged on the side BC side of the casing 29 in the periphery of the opening at the top of the casing 29. FIG. 10 (3) shows a state in which the conductive member 30 is arranged on the side AB side of the casing 29 in the periphery of the opening at the top of the casing 29. FIG. 10 (4) shows a state in which the conductive member 30 is arranged on the side CD side of the housing 29 in the periphery of the upper opening of the housing 29. FIG. 10 (5) shows a state in which the conductive member 30 is arranged along the side AE near the vertex A in the surface ABFE of the housing 29. FIG. 10 (6) shows a state where the conductive member 30 is arranged along the side BF in the vicinity of the vertex B of the surface ABFE of the housing 29. FIG. 10 (7) shows a state in which the conductive member 30 is arranged along the side AB in the vicinity of the vertex B in the surface ABFE of the housing 29. FIG. 10 (8) shows a state in which the conductive member 30 is arranged around the opening at the top of the housing 29 and straddling the side AB.

  10 (1) to 10 (8), the conductive member 30 is positioned in the vicinity of the needle electrode 12 in FIGS. 10 (3), (7), and (8). FIG. 11 is a diagram illustrating the relationship between the position of the conductive member and the discharge current. As shown in FIG. 11, in FIGS. 10 (3), (7), and (8) where the conductive member 30 is located in the vicinity of the needle electrode 12, the result is that the discharge current is larger than in other cases. It was.

  As described above, the particle collection device included in the particle detection device 1 of the present invention charges the particles 40 between the needle electrode 12 and the collection substrate 11 provided at a position facing the needle electrode 12. An apparatus for collecting particles 40 on the collection substrate 11, an insulating casing 29 containing the needle electrode 12 and the collection substrate 11, and an outer surface of the casing 29. The electroconductive member 30 provided in the surface located in the vicinity of the needle electrode 12 and the FPC cable which earth | grounds the electroconductive member 30 are provided.

  When the particles 40 are charged, the inside of the housing 29 is also negatively charged, and the needle electrode 12 is difficult to discharge. However, since the conductive member 30 is provided in the vicinity of the needle electrode 12 and on the outer surface of the housing 29, the electrical charge in the vicinity of the needle electrode 12 in the housing 29 can be released to the ground. Thereby, it is possible to prevent the discharge capability of the needle electrode 12 from being lowered without missing the charge of the entire housing 29. Therefore, the discharge capacity can be stabilized by an inexpensive method.

  Note that the fan 17 is used for both the collection process, the cooling during the heating process, and the refresh process, so that the particle detector 1 can be reduced in size and cost.

<Second Embodiment>
FIG. 12 is a diagram illustrating an example of a particle detection apparatus according to the second embodiment. Fig.12 (a) is a front view, FIG.12 (b) is an arrow line view of the AA line of Fig.12 (a). The particle detector 1A shown in FIG. 12 is different from the particle detector 1 shown in FIG. 2 in that the suction cylinder 18 is changed to the suction cylinder 18A (the phosphor detector 27 is not shown). The suction cylinder 18 </ b> A has an insulating property like the suction cylinder 18.

  The suction cylinder 18 </ b> A is provided at a position where the upper part of the cylinder is located in the opening of the upper part of the housing 29 and the lower part of the cylinder faces the collection substrate 11. Further, the suction cylinder 18A is provided with an opening (penetration opening) on a side surface, and the opening is a slit (penetration opening) 51, for example.

  As shown in FIG. 13, the lateral width W2 of the slit 51 is set larger than the slit of the suction cylinder 18 having the lateral width W1 equivalent to the thickness (diameter) of the needle electrode 12. That is, the lateral width W <b> 2 of the slit 51 is larger than the thickness of the needle electrode 12. For this reason, it is possible to penetrate the slit 51 in a state where the needle electrode 12 is not in contact with the suction cylinder 18A. Specifically, the shortest distance between the needle electrode 12 and the suction cylinder 18A is preferably 1 mm or more.

  Thus, since the needle electrode 12 penetrates without contacting the suction cylinder 18A, it is possible to suppress the accumulation of charges in the suction cylinder 18A and the increase of the surface potential. Thereby, the discharge stability and discharge capability of the needle electrode 12 can be improved. Here, the case where the opening is the slit 51 has been described as an example, but the shape is not limited to the slit 51.

  Here, for each of the particle detection device 1 in which the needle electrode 12 and the suction cylinder 18 are in contact and the particle detection device 1A in which the needle electrode 12 and the suction cylinder 18A are not in contact with each other, the collection substrate 11 and the ground when the needle electrode 12 is discharged A voltage measuring method and a measurement result will be described. For each of the particle detection devices 1 and 1A, the interval (mm) between the needle electrode 12 and the collection substrate 11 and the overlapping amount (mm) between the needle electrode 12 and the collection substrate 11 in plan view are set to a plurality of types of parameters. Then, a high voltage pulse of 4 kV (1.5 ms) was applied between the needle electrode 12 and the collection substrate 11, and the voltage between the collection substrate 11 and the ground was measured.

  In the particle detector 1, the thickness (diameter) of the needle electrode 12 and the lateral width W1 of the slit of the suction cylinder 18 were set to 0.8 mm. In the particle detector 1A, the thickness of the needle electrode 12 was 0.8 mm, the lateral width W2 of the slit 51 of the suction cylinder 18A was 2.5 mm, and the distance between the needle electrode 12 and the suction cylinder 18A was 5 mm.

  FIG. 14 is a diagram illustrating the amount of overlap between the needle electrode and the collection substrate and the distance between the needle electrode and the collection substrate in a state in plan view. As shown in FIG. 14, the height h indicates the distance between the needle electrode 12 and the collection substrate 11, and the width w indicates the amount of overlap between the needle electrode 12 and the collection substrate 11.

  FIG. 15 is a diagram illustrating measurement results. As shown in FIG. 15, even when the distance between the needle electrode 12 and the collection substrate 11 and the overlap amount between the needle electrode 12 and the collection substrate 11 are the same in the particle detection device 1 and the particle detection device 1A. As a result, the particle detector 1A was about 1.5 times or more, and the voltage between the collection substrate 11 and the ground was increased. Therefore, it was confirmed that the particle detection device 1A has improved discharge stability and discharge capacity than the particle detection device 1.

  In addition, when the discharge is performed for a long time under the condition of the interval 10 (mm) between the needle electrode 12 and the collection substrate 11 and the overlap amount 0 (mm) between the needle electrode 12 and the collection substrate 11, the first implementation is performed. When the configuration of the embodiment and the configuration of the second embodiment are compared, the result of the ON / OFF output fluctuation in the configuration of the second embodiment is smaller than that of the configuration of the first embodiment.

<Third Embodiment>
FIG. 16 is a diagram illustrating an example of a particle detection apparatus according to the third embodiment. The particle detection device 1B according to the third embodiment is different from the particle detection devices 1 and 1A according to the first and second embodiments in that the needle electrode 12 is covered with a covering member 53 except for the tip. The suction cylinder 18B of the particle detector 1B may be the same as the suction cylinder 18 or the suction cylinder 18A.

  The covering member 53 is a member that is easier to hold charges (having a higher dielectric constant) than the suction cylinders 18 and 18A, and is, for example, grease. The material of the suction cylinders 18 and 18A is, for example, polycarbonate here.

  Therefore, since the electric charge generated in the needle electrode 12 is held not in the suction cylinder 18B but in the covering member 53, the discharge stability can be further improved.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

1,1A, 1B Particle detector 11 Collection substrate (collection electrode)
12 Needle electrode (high voltage electrode)
13 High pressure generation circuit 14 Collection part 17 Fan (suction member)
18, 18A, 18B Suction cylinder (insulating second structure)
19 Heater 20 Ultrasonic vibrator 21 Light emitting element 22 Condensing lens 23 Excitation light source part 24 Light receiving element 25 Fresnel lens 26 Light receiving part 27 Fluorescence detection part 29 Case (insulating first structure)
30 Conductive member 40A Biological particle 40B Dust 51 Slit (opening for penetration)
53 Coating member

Claims (8)

A particle collecting device for charging particles between a high voltage electrode and a collecting electrode provided at a position facing the high voltage electrode, and collecting the particles on the collecting electrode,
An insulating first structure which is a hollow casing in which the high-voltage electrode and the collecting electrode are disposed ;
A conductive member;
Grounding means for grounding the conductive member;
The high voltage electrode is disposed near the first and second wall surfaces in the first structure,
The conductive member extends along the side in the vicinity of the outer surface of the housing outside the first or second wall surface and the side formed by the intersection of the first wall surface and the second wall surface. The particle collecting apparatus , wherein the conductive member is disposed across the side on the outer surface of the housing outside the first and second wall surfaces .   The particle collecting apparatus according to claim 1, wherein the grounding means is an FPC cable.   The particle collecting apparatus according to claim 1, wherein the high voltage electrode has a needle shape. A suction member that forms a flow of air in a direction facing the collecting electrode;
The conductive member may be provided in a position which does not interfere with the flow of air formed by the suction member, the particle collection device according to any one of claims 1 to 3. An insulating second structure enclosed in the insulating first structure;
The insulating second structure is a hollow member having openings at both ends,
One of the openings at both ends faces the collecting electrode,
The insulating second structure is characterized by enclosing at least a portion of the high voltage electrode, particle collection device according to any one of claims 1 to 4. The insulating second structure has a through-opening other than the openings at both ends,
The particle collector according to claim 5, wherein the high-voltage electrode penetrates the penetration opening from the outside to the inside in a state of non-contact with the insulating second structure. .   7. The particle trap according to claim 5, wherein the high-voltage electrode is covered with a covering member having a dielectric constant higher than that of the insulating second structure except for a front end portion thereof. Collector. Characterized in that it comprises a particle collection device according to any one of claims 1 to 7, the particle detector.

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