KR101132406B1 - Optical Scattering Type Paticle Measurement Apparatus - Google Patents

Abstract

The present invention relates to a light scattering particle measuring apparatus, and equipped with a reflection mirror in the measurement chamber to increase the amount of scattered light received by the light detection unit and at the same time configured so that the reflected scattered light by the reflection mirror does not pass through the focus region of the incident light Thereby increasing the measured value of the intensity against the scattered light and thus reducing the measurement error due to noise, thereby allowing the measurement of particles of a relatively smaller size, which is generated by the particles in the focal region where the particle flow is concentrated. The present invention provides a light scattering particle measuring device that prevents interference to reflected scattered light and provides more accurate and improved measurement results.

Light Scattering, Particle Measuring Equipment, Intensity, Noise, Reflection Mirror

Description

Optical Scattering Type Paticle Measurement Apparatus

The present invention relates to a light scattering particle measuring device. More specifically, by mounting a reflecting mirror in the measurement chamber to increase the amount of scattered light received by the light detector and to configure the reflected scattered light by the reflecting mirror not to pass through the focal region of the incident light, thereby measuring the intensity of the scattered light. By increasing the value and thus reducing the measurement error caused by noise, it is possible to measure particles of a relatively smaller size and to prevent interference with the reflected scattered light generated by the particles in the focal region where the particle flow is concentrated. A light scattering particle measuring device for providing accurate and reliable measurement results.

In general, nano-level high precision processes such as semiconductor processes and LCD processes can lead to fatal product defects if contaminants are generated in the work facility. Therefore, in a clean facility such as a clean room, a high level of cleanliness can be maintained. The process is underway and real-time monitoring of contaminated particles is also very strict at these facilities.

Therefore, in such a facility, a separate particle measuring device for measuring polluted particles in the facility is used, and the particle distribution state of a specific chamber in the facility is measured in real time through the particle measuring device.

Such a particle measuring device measures the distribution state of particles in an arbitrary measurement chamber, that is, the size and number of particles, and the like to measure the distribution state of air pollutant particles in addition to the clean room equipment or to measure the distribution state of specific particles in a laboratory or the like. It is widely used in a variety of fields, such as used for.

The type of particle measuring device is classified into various types according to the size of the particle or the measuring method. The particle measuring device for measuring nano-level particles is generally classified into light scattering and light absorption by light. do.

The light scattering method detects scattered light generated by collision with particles flowing in the space inside the measuring chamber after incident light into the measuring chamber and determines the size and number of particles. It is a method of determining the size and number of particles by detecting the amount of light absorbed by the particles flowing in the measurement chamber after entering the light, the two types of particle measuring device is selectively used widely according to the needs of the user.

Looking more closely at the principle of the light scattering particle measuring apparatus, the incident light is generated to form a focal point in the measurement chamber, and the scattered light generated by the collision of the incident light with particles passing through the focal region of the incident light By detecting the size and number of particles is measured. At this time, when the particle size is 0.05μm to 4μm, the particle size can be theoretically calculated by applying the Mie theory to determine the relationship between the particle size and the light intensity, the general light scattering particle measuring device is Likewise, the intensity and the number of particles are measured by comparing the intensity of the scattered light theoretically calculated with the intensity value of the scattered light actually measured.

However, such a conventional light scattering particle measuring apparatus according to the prior art generates a lot of noise in the process of measuring the intensity value of the actual scattered light, this noise value may be generated larger than the intensity of the actual scattered light. Therefore, it is not possible to distinguish whether the measured intensity is noise or the intensity of the scattered light, which causes a problem that an error occurs in the measurement result. In particular, in the Mie region to which the Mie theory can be applied (the region where the particle size is 0.05 μm to 4 μm), the smaller the particle size, the smaller the intensity of the scattered light is generated, and only a part of the scattered light in the structure of the particle measuring device. Since the intensity of the scattered light is measured to be smaller due to light reception and detection, the disturbance of the intensity value due to noise is further increased, and there is a problem that the reliability of the measurement result is greatly degraded even by relatively small noise. In addition, the light scattering particle measuring apparatus according to the prior art can not be used to measure small particles due to the above reasons can only be used limitedly when measuring large particles that generate a relatively large intensity value There was.

The present invention has been invented to solve the problems of the prior art, an object of the present invention is to increase the measured value of the intensity of the scattered light by mounting a reflection mirror in the measurement chamber to increase the amount of scattered light received by the light detector; The present invention provides a light scattering particle measuring apparatus capable of measuring particles having a relatively smaller size by reducing measurement errors caused by noise, thereby improving reliability of the measurement results.

Another object of the present invention is configured so that the reflected scattered light reflected by the reflecting mirror and received by the light detector does not pass through the focal region of the incident light, thereby interfering with the reflected scattered light generated by the particles in the focal region where the flow of particles is concentrated. This prevents the reflected scattered light in the intact state without changing the characteristic is received by the light detection unit, thereby providing a light scattering type particle measuring device that provides a more accurate measurement results.

Another object of the present invention is to vary the focal position of the incident light generated by the light generating unit in the measurement chamber, thereby scanning the area where the particle flow is concentrated, thereby adjusting the distribution of particles in the measurement chamber. It is to provide a light scattering particle measuring apparatus that can be measured more accurately.

Another object of the present invention is configured to adjust the relative position of the light detector relative to the light generating unit, the space required for installation is reduced, so that the spatial constraints are relatively relaxed, the installation is easier and the installation application range is more It is an object of the present invention to provide an extended light scattering particle measuring apparatus.

The present invention provides a light scattering particle measuring apparatus for measuring a distribution state of particles flowing in a measurement chamber using scattered light, comprising: a light generator for generating incident light to form a focal point in the measurement chamber; A light detector configured to receive and detect scattered light generated by collision between the incident light and particles passing through a focal region of the incident light; And a reflection mirror reflecting the scattered light to the light detector so that the amount of scattered light received by the light detector may increase, wherein the reflected mirror reflects the focal region of the incident light. Provided is a light scattering particle measuring device, characterized in that arranged so as not to pass.

In this case, the light generator and the light detector are disposed on the same plane in the direction perpendicular to the flow direction of the particles, the reflection mirror and the light detector is on different planes in the direction perpendicular to the flow direction of the particles. It may be arranged to be located.

In addition, the reflection mirror may be disposed so that the reflected scattered light by the reflection mirror does not pass through a straight region extending the focal region of the incident light in the particle flow direction.

In addition, the particle measuring device further comprises a hollow case having a length along the flow direction of the particles in communication with the measuring chamber to form the measuring chamber, the light detector is a plane perpendicular to the flow direction of the particles It may be mounted on the case to be movable along the outer circumference of the case on.

In addition, it may be configured to further include a reflection mirror actuator that can adjust the reflection angle of the reflection mirror.

In addition, the light generation unit, a laser diode for generating laser light; A focusing lens for focusing the laser light generated by the laser diode; A focusing mirror that reflects incident light passing through the focusing lens to be focused on one focal region; And a focusing mirror actuator capable of adjusting a reflection angle of the focusing mirror so as to change a focus position of the incident light.

According to the present invention, by mounting a reflecting mirror in the measuring chamber to increase the amount of scattered light received by the light detector, the measured value of the intensity for the scattered light is increased, thereby reducing the measurement error due to noise, which is relatively smaller. Particles of size can be measured and there is an effect of improving the reliability of the measurement results.

In addition, the reflection scattered light reflected by the reflection mirror and received by the light detector is configured not to pass through the focal region of the incident light, thereby preventing interference with the reflected scattered light generated by the particles in the focal region where the flow of the particles is concentrated. Reflected scattered light in an intact state is received by the light detector without change, thereby providing a more accurate measurement result.

In addition, by varying the focal position of the incident light generated by the light generating unit in the measurement chamber, it is possible to scan the area where the particle flow is concentrated, thereby measuring the distribution state of the particles in the measurement chamber more accurately. It has an effect.

In addition, by configuring the relative position of the light detector relative to the light generating unit, the space required for installation is reduced, so that the spatial constraints are relatively relaxed, the installation is easy, and the installation application range is further extended.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 is a perspective view showing a schematic shape of a light scattering particle measuring apparatus according to an embodiment of the present invention, Figure 2 conceptually illustrates the internal structure of the light scattering particle measuring apparatus according to an embodiment of the present invention 1 is a cross-sectional view taken along the line “AA” of FIG. 1, and FIG. 3 is a line “BB” of FIG. 1 conceptually showing the internal structure of a light scattering particle measuring apparatus according to an exemplary embodiment. It is a cross section taken along.

Light scattering particle measuring apparatus according to an embodiment of the present invention detects the scattered light (R1) generated by the collision of the particles flowing in the interior of the measurement chamber (C) and the incident light (I) measuring chamber (C) A device for measuring the distribution state of particles existing in the particles, that is, the size and number of particles, the light generating unit 200 and the light detecting unit 300 and scattered light (R1) mounted in communication with the measurement chamber (C) is reflected It is configured to include a reflective mirror 400. At this time, the measurement chamber (C) may be applied to a wide variety of devices, such as a clean room equipment that is a facility of the semiconductor process or LCD process or a separate case for measuring the air pollution degree or various experimental devices used in the laboratory.

The light generating unit 200 is an apparatus for generating incident light I to form a focal point F in the inner space of the measuring chamber C. The light generating unit 200 is mounted in communication with the measuring chamber C. It comprises a laser diode 210 and a focusing lens 220 for focusing the laser light generated from the laser diode 210 so that light can be applied. The laser light generated from the laser diode 210 has an emission angle of a certain magnitude, which is focused through the focusing lens 220 and forms a focal point F at a specific point in the space inside the measurement chamber C. . In this case, a plurality of focusing lenses 220 may be mounted, and the number of focusing lenses 220 may be variously changed according to measurement conditions such as the type of the measurement chamber C and the focusing distance. In addition, the focal point F position of the incident light I is preferably formed at the center of the measurement chamber C as shown in FIG. 1, but may be formed at the edge of the measurement chamber C. have. In addition, according to an embodiment of the present invention may be configured to change the position of the focus (F), a detailed description thereof will be described later.

The light detector 300 receives and detects the scattered light R1 generated by the collision between the incident light I generated by the light generator 200 and particles passing through the focal point F region of the incident light I. do. Since the scattered light R1 is generated from the particles in all directions, the light detector 300 collects the scattered light R1 so as to focus and detect a part of the scattered light R1, and the condenser lens. The optical fiber 320 which transmits the scattered light R1 collected by 310 is included, and the detection sensor 330 which detects the scattered light R1 transmitted by the optical fiber 320 is comprised.

Therefore, when the incident light I collides with the particles and scattered light R1 is generated, some of the scattered light R1 is collected by the condenser lens 310 and transmitted to the detection sensor 330 through the optical fiber 320. The intensity of the scattered light R1 is measured by the detection sensor 330. The intensity of the scattered light R1 measured as described above is calculated by comparing the theoretical value to which the Mie theory is applied through a separate calculation unit (not shown). Also, in the case where particles flow in a constant direction in the measurement chamber C according to the flow of a fluid, for example, in a clean room facility, each time the particles pass the focal point F of the incident light I, the scattered light ( Since R1) is generated, the calculator calculates the number of particles through the number of scattered light R1.

Meanwhile, a separate vacuum window 500 is provided at a portion of the light generator 200 and the light detector 300 connected to the measurement chamber C to protect the focusing lens 220 and the condenser lens 310. Preferably, the light generating unit 200 and the light detecting unit 300 are separated from the measurement chamber C.

The reflection mirror 400 is mounted inside the measurement chamber C to reflect a part of the scattered light R1 to the light detector 300. That is, the scattered light (R1) is generated in all directions as described above, some of which are directly received by the light detector 300, some of the remaining scattered light (R1) is reflected by the reflective mirror 400, the light detector 300 is received. In this case, the reflective mirror 400 is preferably formed to form a curved surface as shown in Figure 2 to reflect the scattered light (R1) in a parallel light state, but may be formed to form a plane otherwise .

According to such a structure, since the scattering light R1 is additionally received by the light detector 300 by the reflection mirror 400, the particle measuring device according to the exemplary embodiment of the present invention may be applied to the light detector 300 as compared with the prior art. Since the amount of scattered light R1 received increases, the intensity value of the scattered light R1 increases, so that a relatively large scattered light R1 intensity value can be measured even for a small particle size. The error of the measurement result is reduced.

Looking at the configuration of the particle measuring device according to an embodiment of the present invention in more detail, the particle measuring device is not shown, but is installed directly on the outer wall of the clean room 10 clean room 10 which is the measurement chamber (C) Although it may be installed in a manner to measure the particle size and the number of the interior space, as shown in Figure 1 of the particles flowing in the pipe 11 is mounted in communication with the pipe 11 of the clean room 10 It is preferable to install in the manner of measuring the size and number. In this case, the particle measuring apparatus further includes a separate case 100 in communication with the pipe 11 according to the exemplary embodiment of the present invention, and the light generating unit 200 and the light detecting unit 300 are connected to the case 100. And the reflective mirror 400 may be mounted. The case 100 is formed in a hollow shape so as to communicate with the measuring chamber C to form the measuring chamber C. The light generating unit 200 and the light detecting unit 300 are mounted on the outer surface of the case 100, respectively. The reflective mirror 400 may be mounted on the inner surface of the case 100. At this time, in the clean room 10, the flow of the fluid occurs in a certain direction according to the characteristics of the equipment so that the particles in the measurement chamber (C) flows in a constant direction according to the fluid flow, the case 100 is the flow of such particles It is preferably formed in a hollow shape having a predetermined length along the direction. In addition, the case 100 has a light trap (or light trap) so that the incident light I generated from the light generator 200 at the position opposite to the light generator 200 may continue to disappear after the focal point F is formed. 600) is mounted.

According to this structure, the incident light I forms the focal point F by the light generator 200, is incident into the measurement chamber C, and the incident light I is caused by particles passing through the focal point F region. This scattering causes scattered light R1 in all directions. Some of the scattered light R1 is directly received by the light detector 300, and some of the others are reflected by the reflection mirror 400 and received by the light detector 300. As such, since the scattered light R1 that is directly received by the light detector 300 as well as the reflected scattered light R2 that is received through the reflection mirror 400 is further received, the amount of scattered light R1 as described above. As a result, the intensity of the scattered light R1 detected by the detection sensor 330 increases. Therefore, the intensity of the scattered light R1 increases with respect to particles that are relatively small compared to the prior art, so that measurement errors due to noise are relatively reduced, so that the size and number of the smaller particles can be measured. have. On the other hand, the reflective mirror 400 may be mounted in a large number or a large size so that the amount of the reflected scattered light (R2) received by the light detector 300 can be increased, which can be changed in various ways depending on the installation conditions There will be.

In addition, in the particle measuring apparatus according to the exemplary embodiment, the reflected scattered light R2 reflected by the reflective mirror 400 and received by the light detector 300 passes through the focal point F of the incident light I. The reflection mirror 400 is disposed so as not to. That is, as shown in FIG. 2, when the reflective mirror 400 is located on the same plane in the direction perpendicular to the light detector 300 and the particle flow direction, the reflective mirror 400 faces the light detector 300. It is mounted at a position spaced a certain distance along the inner surface of the case 100 from the point to the reflection scattered light (R2) is configured to receive the light detector 300 without passing through the focal point (F) region of the incident light (I). .

According to this structure, the particle measuring apparatus according to the embodiment of the present invention minimizes the interference between the reflected scattered light R2 by the reflection mirror 400 and the scattered light R1 received directly by the light detector 300, and in particular, The reflected scattered light R2 is completely received by the light detector 300 without interference by particles passing through the focal point F region of the incident light I, thereby obtaining more accurate measurement results.

In more detail, in general, when the flow of the fluid occurs in the measurement chamber (C), the particles in the measurement chamber (C) shows the aspect of the flow through the central portion in the measurement chamber (C) along the flow of the fluid, According to this characteristic, the position where the focal point F of the incident light I is formed is preferably formed at the center of the measurement chamber C where the flow of particles is concentrated, and the reflected scattered light by the reflective mirror 400 is also provided. (R2) is preferably formed so as not to pass through this focal region F in order to avoid interference by particles. Therefore, the particle measuring device according to the embodiment of the present invention is configured so that the reflected scattered light R2 does not pass through the focal point F region of the incident light I to which the particle flow is concentrated, so that the reflection generated by the particles Interference with the scattered light R2 is relatively reduced, resulting in more accurate measurement results.

Meanwhile, as illustrated in FIGS. 1 and 2, the light generator 200 and the light detector 300 may be disposed on the same plane in a direction perpendicular to the flow direction of the particles and disposed at right angles to each other. Accordingly, since the incident light I and the scattered light R1 that have passed through the particles do not interfere with each other, the scattered light R1 is completely received by the light detector 300 without a change due to interference, thereby obtaining more accurate measurement results. . In addition, the light detector 300 may be mounted to the case 100 to be movable along a plane in a direction perpendicular to the flow direction of the particle according to an embodiment of the present invention, which will be described later.

In addition, the reflection mirror 400 and the light detector 300 according to the exemplary embodiment of the present invention may be disposed on different planes in a direction perpendicular to the flow direction of the particles. That is, as shown in FIG. 3, the position of the reflection mirror 400 may be disposed to be located downstream along the particle flow direction compared to the position of the light detector 300, and through such arrangement, the reflection mirror 400 may be disposed. ), While the reflected scattered light R2 does not pass through the focal point F region of the incident light I, the mutual interference between the scattered light R1 and the reflected scattered light R2 received directly by the light detector 300 may be minimized. Could be.

In this case, the reflective mirror 400 is arranged so that the reflected scattered light R2 by the reflective mirror 400 does not pass through the straight line F1 region extending from the focal point F region of the incident light I in the particle flow direction. desirable. That is, as in the case where the reflection mirror 400 and the light detector 300 are located on the same plane in the direction perpendicular to the particle flow direction, the reflected scattered light R2 by the reflection mirror 400 is the focal point of the incident light I. It is preferable to arrange | position so that it may not pass through the center part of the measurement chamber C which is area | region (F). Accordingly, the reflected scattered light R2 does not pass through the central portion of the measurement chamber C where the flow of incident light I is concentrated, so that interference caused by particles is relatively reduced, resulting in more accurate measurement of the scattered light R1. You can get it.

FIG. 4 is a cross-sectional view taken along line “AA” of FIG. 1 to conceptually show an internal structure of a light scattering particle measuring apparatus according to another exemplary embodiment of the present invention, and FIG. 5 is yet another embodiment of the present invention. FIG. 1 is a cross-sectional view taken along the line “AA” of FIG. 1 to conceptually show an internal structure and an operating state of a light scattering particle measuring apparatus according to an embodiment.

As illustrated in FIG. 4, the light generator 200 according to another exemplary embodiment of the present invention is configured to change the position of the focus F of the incident light I. Referring to FIG. That is, the light generator 200 includes the laser diode 210 for generating the laser light and the focusing lens 220 for focusing the laser light as described above. F) It further comprises a focusing mirror 230 and a focusing mirror actuator 240 to change the position.

In more detail, the laser light generated by the laser diode 210 may be incident through the focusing lens 220 so that the focal point F is formed at the center of the inside of the measurement chamber C. According to another embodiment of the present invention, the laser light passing through the focusing lens 220 is reflected by a separate focusing mirror 230 and may be configured such that a focal point F is formed in the measurement chamber C. . The focusing mirror 230 may be formed in a sphere or a plane according to the shape of the laser light passing through the focusing lens 220, and the incident light I reflected through the focusing mirror 230 is an internal space of the measurement chamber C. It is configured to form a focus F on.

At this time, the focusing mirror 230 is configured to adjust the mounting angle by the focusing mirror actuator 240 and is configured to adjust the reflection angle of the incident light (I). Therefore, the incident light I reflected through the focusing mirror 230 is focused on the focal spot F formed in the measurement chamber C internal space by adjusting the reflection angle of the focusing mirror 230 through the focusing mirror actuator 240. The position will change. According to this structure, the position of the focal point F of the incident light I may be changed to the center portion or the edge portion of the measurement chamber C. FIG.

Therefore, the light scattering particle measuring apparatus according to an embodiment of the present invention can change the focal point F of the incident light I to various positions in the measurement chamber C, so that the flow of particles is concentrated. The area can be scanned to find the optimum measurement conditions, thus providing more reliable measurement results.

On the other hand, in this case, when the position of the focus F of the incident light I changes, the reflected scattered light R2 by the reflective mirror 400 may pass through the focus F region of the incident light I in some cases. In order to prevent this, it is preferable to mount a separate reflection mirror actuator 410 to adjust the reflection angle of the reflection mirror 400, which is also useful when the position of the light detector 300 is moved as will be described later. Can be applied.

The focusing mirror actuator 240 and the reflection mirror actuator 410 change the mounting angle of the focusing mirror 230 or the reflection mirror 400, and a driving motor (not shown) and a link device (not shown). It can be configured in a variety of ways through its mechanical elements.

FIG. 5 illustrates a structure and an operating state in which the light detector 300 is movably mounted, and the light detector 300 according to another embodiment of the present invention has a flow direction of particles as shown in FIG. 5. It may be mounted to the case 100 to be movable along the outer circumference of the case 100 on a plane in a direction perpendicular to the.

The structure in which the light detector 300 is movably mounted along the outer circumference of the case 100 may be formed by separating the case 100 into the inner case 120 and the outer case 110, as shown in FIG. 5. The inner case 120 may be rotatably coupled to the fixed outer case 110 in a rail structure. In this case, the light detector 300 is mounted on the rotating inner case 120, and the light generator 200 is mounted on the fixed outer case 110.

Through this structure, as shown in FIG. 5A, the light generating unit 200 and the light detecting unit 300 may be disposed to be perpendicular to each other on the same plane, as shown in FIG. 5B. As described above, the light detector 300 may be rotated to form an obtuse angle with the light generator 200. Since the scattered light R1 is generated in all directions as described above, even if the position of the light detector 300 is changed, the amount of scattered light R1 received by the light detector 300 remains constant without change. Since the path of the reflected scattered light R2 by the mirror 400 should be changed according to the positional movement of the light detector 300, the reflective mirror actuator 410 to adjust the reflection angle of the reflective mirror 400 as described above. It is preferable that the reflection mirror actuator 410 is controlled to be controlled so that the reflection angle is automatically adjusted through a separate control unit (not shown) according to the position change of the light detector 300. .

As the particle measuring apparatus according to another embodiment of the present invention is changed as described above, the space required for installation may be relatively small, and thus the particle measuring apparatus may be applied to more various environments. That is, when the positions of the light generating unit 200 and the light detecting unit 300 are fixed, it is difficult to install the particle measuring device due to the interference with the surrounding equipment depending on the shape of the measuring chamber C or even the particle measuring device. Although it may not be installed, if the position of the light detector 300 is changed according to an embodiment of the present invention, such spatial constraints may be relatively relaxed, so that the installation may be easier and the installation application range may be further extended. .

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a perspective view showing a schematic shape of a light scattering particle measuring apparatus according to an embodiment of the present invention,

FIG. 2 is a cross-sectional view taken along line “A-A” of FIG. 1 to conceptually show an internal structure of a light scattering particle measuring apparatus according to an embodiment of the present invention;

3 is a cross-sectional view taken along line “B-B” of FIG. 1 to conceptually show an internal structure of a light scattering particle measuring apparatus according to an embodiment of the present invention;

4 is a cross-sectional view taken along line “A-A” of FIG. 1 to conceptually show an internal structure of a light scattering particle measuring apparatus according to another embodiment of the present invention;

FIG. 5 is a cross-sectional view taken along line “A-A” of FIG. 1 to conceptually show an internal structure and an operating state of a light scattering particle measuring apparatus according to another exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: case 200: light generating unit

230: focusing mirror 300: light detector

400: reflection mirror 410: reflection mirror actuator

I: incident light R1: scattered light

R2: reflected scattered light

Claims (6)

In the light scattering type particle measuring device for measuring the distribution state of the particles flowing in the interior of the measurement chamber using the scattered light, A light generator for generating incident light to form a focal point in the measurement chamber; A light detector configured to receive and detect scattered light generated by collision between the incident light and particles passing through a focal region of the incident light; A reflection mirror reflecting the scattered light to the light detector so that the amount of scattered light received by the light detector increases; And A hollow case communicating with the measuring chamber to form the measuring chamber and having a length along the flow direction of the particles. And the reflection mirror is arranged such that the reflected scattered light reflected by the reflective mirror does not pass through the focal region of the incident light. The method of claim 1, The light generating unit and the light detecting unit are disposed to be located on the same plane in a direction perpendicular to the flow direction of the particles, and the reflection mirror and the light detection unit are located on different planes in a direction perpendicular to the flow direction of the particles. Light scattering type particle measurement device, characterized in that arranged. The method of claim 2, And the reflection mirror is disposed so that the reflected scattered light by the reflection mirror does not pass through a linear region extending from the focal region of the incident light in the particle flow direction. 4. The method according to any one of claims 1 to 3, And the light detector is mounted to the case to be movable along the outer circumference of the case on a plane perpendicular to the flow direction of the particle. The method of claim 4, wherein Light scattering particle measurement device further comprises a reflection mirror actuator capable of adjusting the reflection angle of the reflection mirror. 4. The method according to any one of claims 1 to 3, The light generating unit A laser diode for generating laser light; A focusing lens for focusing the laser light generated by the laser diode; A focusing mirror that reflects incident light passing through the focusing lens to be focused on one focal region; And Focusing mirror actuator for adjusting the reflection angle of the focusing mirror to change the focus position of the incident light Light scattering type particle measuring device comprising a.

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