JP2005283152A - Pollen sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pollen sensor that can count the number of pollen particles in real time at a location to be measured without requiring any special experience, and can precisely identify pollen particles and dust. <P>SOLUTION: The pollen sensor comprises an emission means for applying irradiation light in a prescribed polarization direction into air containing floating particles; a first light reception means for measuring intensity I in scattered light, by detecting scattered light by the floating particles; a second light reception means for measuring intensity Is in orthogonal scattered light, by detecting scattered light in the polarization direction orthogonally crossing the polarization direction of irradiation light in scattered light by the floating particles; and an identification means for identifying pollen particles and dust, on the basis of the intensity I in the scattered light and the intensity Is in the orthogonal scattered light. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pollen sensor, and more particularly to a pollen sensor used for detecting pollen particles floating in the air that causes hay fever.

  Conventionally, pollen particles floating in the atmosphere are counted by leaving the slide glass coated with an adhesive such as petrolatum in the atmosphere for 24 hours, collecting the pollen particles that fall naturally with the adhesive, and dyeing it. After that, it has been performed by a microscopic method in which a skilled person visually counts using a microscope.

  However, the above-described microscopy requires a lot of time for the time-consuming pretreatment of staining, and a high level of skill is required for those who perform visual counting. Moreover, since the slide glass must be left in the atmosphere for a certain period of time, there is a problem that pollen particles cannot be detected in real time. Furthermore, there is a problem that a measurement result cannot be obtained at a place to be measured.

Therefore, a pollen detector using polarized light is disclosed (for example, see Patent Document 1). If this pollen detector is used, the measurement result can be obtained at a place to be measured in real time without the labor and skill of microscopy. However, there is a problem that pollen particles and dust (which occupies most of the floating particles in the outdoor air) are insufficiently distinguished, and there is an erroneous count that determines that the dust is pollen particles.
Japanese Patent No. 3113720

  The present invention solves such problems, and the object of the present invention is to perform pollen particle counting in real time at a place to be measured without requiring any special skill. It is an object of the present invention to provide a pollen sensor capable of discriminating between dust and dust with high accuracy.

The present invention has been completed based on the fact that pollen particles and dust differ in particle size and particle anisotropy.

  Here, when irradiation particles (electromagnetic waves) are irradiated with floating particles, the floating particles are polarized in the direction of vibration of the electric field, and an electric dipole is formed. This polarization direction is greatly influenced by the anisotropy of the particles. Since the polarization direction of the isotropic particle is equal to the polarization direction of the irradiated irradiation light (hereinafter referred to as the irradiation deflection direction), the polarization direction of the scattered scattered light is equal to the irradiation polarization direction.

  On the other hand, in the case of particles having anisotropy or particles having a particle diameter larger than the wavelength of irradiation light, the polarization direction is determined by a polarization tensor peculiar to the particles. Since the dust has a larger anisotropy than the pollen particles, when the irradiation light in the irradiation polarization direction is scattered by the dust, the scattered light in the polarization direction orthogonal to the irradiation polarization direction is strongly included.

  That is, since the anisotropy of the pollen particles is different from the anisotropy of the dust, the relationship between the intensity I of the scattered light by the pollen particles and the intensity Is of the orthogonal scattered light is as follows. It is different from the relationship with the light intensity Is.

  However, generally, when the particle size changes, the relationship between the intensity I of scattered light and the intensity Is of orthogonal scattered light also changes.

  Therefore, since the intensity I of the scattered light increases as the particle diameter increases, the size of the particle diameter can be determined by measuring the intensity I of the scattered light.

  Therefore, it is possible to distinguish pollen particles from dust by measuring the size of the particle diameter based on the scattered light intensity I and the anisotropy of the particle based on the relationship between the scattered light intensity I and the orthogonal scattered light intensity Is. Can be done.

  Here, the intensity I of scattered light and the intensity Is of orthogonal scattered light according to the present invention will be described. In FIG. 4, solid arrows indicate the polarization direction of light, and broken arrows indicate the direction of the polarization axis of the polarizing element.

  The light emitting means has a semiconductor laser 51 and a lens 52. The light emitted from the semiconductor laser 51 is polarized in a predetermined polarization direction, and this light is condensed at a predetermined position by the lens 52 and irradiated to the suspended particles 60 passing through the predetermined position.

  The first light receiving means has a lens 53 and a photodiode 54, and the scattered light from the suspended particles 60 reaches the photodiode 54 via the lens 53. Therefore, the intensity I of scattered light can be obtained from the photodiode 54.

  On the other hand, the second light receiving means includes a lens 55, a polarizing filter 56, and a photodiode 57, and scattered light from the suspended particles 60 reaches the photodiode 57 through the lens 55 and the polarizing filter 56. The polarization axis of the polarizing filter 56 is set to a polarization direction orthogonal to a predetermined polarization direction. Therefore, the intensity Is of orthogonal scattered light can be obtained from the photodiode 57.

  That is, pollen particles are obtained by knowing the size of the particle diameter by measuring the intensity I of the scattered light and knowing the anisotropy of the particles by measuring the relationship between the intensity I of the scattered light and the intensity Is of the orthogonal scattered light. And dust can be identified.

  Furthermore, the degree of polarization D can be obtained from the intensity I of the obtained scattered light and the intensity Is of the orthogonal scattered light. Comparing the degree of polarization D between the pollen particles and the dust, the degree of polarization D of the pollen particles is significantly different from the degree of polarization D of the dust. Therefore, it is possible to identify the pollen particles and the dust with higher accuracy. Become.

  In addition, when a matrix composed of the degree of polarization D and the intensity I of scattered light is used to identify those in a predetermined region as pollen particles, it is possible to identify pollen particles and dust with particularly high accuracy. It becomes possible.

  That is, the pollen sensor of the present invention includes a light emitting means for irradiating the air containing floating particles with irradiation light in a predetermined deflection direction, and detecting scattered light from the floating particles and measuring the intensity I of the scattered light. A first light receiving means, a second light receiving means for detecting the scattered light in the polarization direction orthogonal to the polarization direction of the irradiation light of the scattered light by the suspended particles, and measuring the intensity Is of the orthogonal scattered light; and An identification means for identifying pollen particles and dust based on the intensity I and the intensity Is of the orthogonal scattered light is provided.

  In the pollen sensor of the present invention, the identification means uses any one of the following degrees of polarization D1, D2, and D3 in which the intensity I of the scattered light and the intensity Is of the orthogonal scattered light are used, and the intensity of the scattered light. Identification is preferably performed based on I.

Polarization degree D1 = (I−Is) / (I + Is)
Degree of polarization D2 = (I−Is) / I
Polarization degree D3 = Is / I
Furthermore, in the pollen sensor according to the present invention, the identification means includes any one of the polarization degrees D1, D2, and D3 and the intensity I of the scattered light, which is determined in advance. It is preferable to identify as a pollen particle what is in the matrix composed of the one and the intensity I of the scattered light.

  If the pollen sensor of the present invention is used, pretreatment such as dyeing is not required as in the prior art, so it does not take much time, and it is not necessary to observe with a microscope. However, pollen particles can be easily measured. Further, pollen particles and dust can be discriminated in real time at a place to be measured, and pollen particles can be counted, so that pollen information can be obtained quickly. In particular, since identification is performed based on the intensity I of scattered light and the intensity Is of orthogonal scattered light, it becomes possible to identify pollen particles and dust with high accuracy.

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

  FIG. 1: has shown the side view (a part is made into sectional drawing) of the pollen sensor of one Embodiment of this invention. The pollen sensor 20 of the embodiment includes the light emitting means 1, the first light receiving means 2, and the second light receiving means 3 in the light shielding housing 19, and further includes an identification means (not shown).

  The light emitting means 1, the first light receiving means 2, and the second light receiving means 3 are arranged on the same vertical plane. Further, the light emitting means 1 irradiates the irradiation light horizontally toward the detection area F. The first light receiving means 2 is arranged at an angle of 60 ° upward from the center of the detection area F, while the second light receiving means 3 is 60 ° downward from the center of the detection area F. Are arranged at an angle of

  The light shielding housing 19 includes the air suction port 4 below the detection area F and the suction fan 5 above the detection area F. Accordingly, the sample air enters the light shielding housing 19 from the air suction port 4 at a constant flow rate, passes through the detection area F, and is discharged from the suction fan 5 to the outside of the light shielding housing 19.

The light emitting means 1 is composed of a semiconductor laser 6 and a lens 7. The semiconductor laser 6 emits light having a predetermined polarization direction, and the lens 7 irradiates the light emitted from the semiconductor laser 6 toward the detection area F as parallel light.
The first light receiving means 2 includes a lens 8 and a photodiode 9. The lens 8 collects the scattered light caused by the suspended particles, and the photodiode 9 outputs a first current. Thereby, the intensity I of scattered light from the photodiode 9 is measured.

  The second light receiving means 3 includes a lens 10, a polarizing filter 11, and a photodiode 12. The lens 10 collects the scattered light caused by the suspended particles, the polarizing filter 11 transmits only the scattered light in the polarization direction orthogonal to the irradiation polarization direction of the collected scattered light, and the photodiode 12 2 currents are output. As a result, the intensity Is of the orthogonal scattered light from the photodiode 12 is measured.

The size of the detection area is preferably about 1 cm ³ .

  Therefore, in the pollen sensor 20 of the embodiment, the light emitted from the semiconductor laser 6 is irradiated to the detection area F as parallel light by the lens 7. Sample air is supplied to the detection area F from the air suction port 4.

  If the sample air contains no suspended particles, the irradiation light from the lens 7 goes straight and does not reach the first light receiving means 2 and the second light receiving means 3. On the other hand, when the suspended air is contained in the sample air, when the suspended particle passes through the detection area F, the irradiation light is scattered and the scattered light reaches the first light receiving means 2 and the second light receiving means 3. At this time, the intensity Is of the orthogonal scattered light is higher than that of pollen particles. Thereafter, the first light receiving means 2 and the second light receiving means 3 that have reached the scattered light output the first current and the second current as described above.

  FIG. 2 is a block diagram illustrating an example of a method for processing the first current and the second current.

  The first current output from the photodiode 9 and the second current output from the photodiode 12 are input to the current-voltage conversion circuit 13 and the current-voltage conversion circuit 14, respectively, and are converted into the first voltage and the second voltage. Converted.

  The first voltage and the second voltage are input to the amplifier circuit 15 and the amplifier circuit 16, respectively, and output the intensity I of scattered light and the intensity Is of orthogonal scattered light.

  Further, the intensity I of the scattered light and the intensity Is of the orthogonal scattered light are input to the identification unit 17.

  In the identification means 17, a ROM and a RAM (Random Access Memory) are connected to a central processing unit (hereinafter referred to as CPU) of the control unit.

  The ROM is a matrix composed of data on the degree of polarization D ′, a program for calculating the degree of polarization D using the intensity I of scattered light and the intensity Is of orthogonal scattered light, and a degree of polarization D ′ and intensity I ′ of scattered light. The data etc. are memorized. Furthermore, based on the obtained degree of polarization D and scattered light intensity I, a program for discriminating between pollen particles and dust while using a matrix is stored.

  The matrix data described above is data composed of the polarization degree D ′ and the scattered light intensity I ′. For example, the polarization degree D ′ is “−1.0 or more and less than −0.9” or “−0. It is classified into 20 stages of “9 or more and less than −0.8”, “0.9 or more and 1.0 or less”, and the scattered light intensity I ′ is “0.0 V or more and less than 0.5 V” or “0.5 V” It is data of a matrix that is classified into 16 levels of “less than 1.0 V” and “7.5 V or more and 8.0 V or less”. Therefore, 320 types of cells in the matrix and 321 types are classified as those outside the matrix.

  Further, in the matrix data, predetermined squares among the 320 kinds of squares are “a square having a probability of being pollen particles of 90% or more” and “a square having a probability of being pollen particles of 70% or more”. And “mass that is not pollen particles” (see FIG. 3). The predetermined mass is determined by measuring pollen particles and dust in advance with the pollen sensor 20 and performing statistical processing.

  The data of the degree of polarization D ′ is, for example, data indicating the degree of polarization D = (I−Is) / (I + Is).

  The RAM also stores variable values used in the above-described program. For example, the result of arithmetic processing by the CPU is stored.

  Then, the CPU performs arithmetic processing by calling and executing a predetermined program, and transmits as electronic data based on the result of the arithmetic processing.

  Therefore, when the CPU receives the scattered light intensity I and the orthogonal scattered light intensity Is, the CPU calculates the scattered light intensity I and the orthogonal scattered light intensity Is based on the program stored in the ROM. The degree of polarization D is obtained by calculation. It is assumed that the pollen sensor 20 is activated, and the variables used in the CPU described above are initialized to a predetermined value (for example, 0) and are in steady operation.

  Next, based on the obtained degree of polarization D and the intensity I of scattered light, the matrix is used to determine which mass of the matrix corresponds.

  For example, when it is determined that the polarization degree D is “0.4 or more and less than 0.5” and the scattered light intensity I is “2.5 V or more and less than 3.0 V”, the polarization degree D is “0.4”. The data is stored in the RAM as +1 for the square in which the scattered light intensity I is “2.5 V or more and less than 3.0 V”. At this time, it is assumed that the probability of being pollen particles is 90% or more.

  On the other hand, when it is determined that the polarization degree D is “0.0 or more and less than 0.1” and the intensity I of the scattered light is “1.0 V or more and less than 1.5 V”, the polarization degree D is “0.0”. In the RAM, data is set to +1 in a square in which the scattered light intensity I is “1.0 V or more and less than 1.5 V”. At this time, it is assumed that the particles are not pollen particles.

  Further, when it is determined that the degree of polarization D is “0.0 or more and less than 0.1” and the intensity I of scattered light is “9.0 V”, data is not stored in the RAM.

  The degree of polarization D ′ data, a program for calculating the degree of polarization D by using the intensity I of scattered light and the intensity Is of orthogonal scattered light in the ROM, and the degree of polarization D ′ and the intensity I ′ of scattered light. Based on the matrix data, the degree of polarization D obtained and the intensity I of scattered light, a program for discriminating between pollen particles and dirt while using the matrix is stored in plural types as necessary. It may be set to a different one. If it does in this way, it can be changed in arbitrary places and time.

  Furthermore, the pollen sensor of the present invention may be provided with a rewritable nonvolatile memory such as a flash memory that does not require a backup power supply, and data may be stored in the memory. For example, data is stored in one pollen sensor on a certain measurement day, and the data is stored even when the measurement day ends and the supply of power to the one pollen sensor is stopped. Therefore, pollen information based on the stored data can be acquired on the day after the measurement date.

  In this specification, it is described that the number of CPUs included in the control unit is one. However, in the pollen sensor of the present invention, the number of CPUs included in the control unit is not necessarily one. The number of ROMs and RAMs included in the control unit is not necessarily one.

  Next, Tables 1 and 2 show the results of measuring cedar pollen and Kanto loam (1.7 kinds of powder for JIS test) using the pollen sensor of this embodiment, respectively.

  From Table 1, there is 61% of the total number of suspended particles in the area of “mass where the probability of being pollen particles is 90% or more”, and in the area of “mass where the probability of being pollen particles is 70% or more”. There are 88% of the total suspended particles, and it has been demonstrated that cedar pollen is identified as pollen.

  Also, from Table 2, there is 1% of the total number of suspended particles in the region of “mass where the probability of being pollen particles is 90% or more”, and the region of “mass where the probability of being pollen particles is 70% or more” It is 3.3% of the total number of airborne particles, and it is proved that Kanto Loam is not identified as pollen.

  In addition, as a result of measuring similarly about cypress pollen as pollen other than cedar pollen, it was a measurement result equivalent to cedar pollen. Further, Arizona test dust (ISO 12103-1, A3) was measured in the same manner as the dust other than Kanto Loam. As a result, it was the same measurement result as Kanto Loam.

  On the other hand, cedar pollen and Kanto loam were measured using a pollen detector as in Patent Document 1. As a result, what determined cedar pollen as "pollen particles" was 61% of the total number of suspended particles, and what determined Kanto loam as "pollen particles" was 35% of the total number of particles, The distinction between pollen and dust was insufficient.

  In the pollen sensor 20, the first light receiving means 2 is disposed at an angle of 60 ° upward from the center of the detection area F, while the second light receiving means 3 is downward from the center of the detection area F. However, it may be arranged at any other angle, may be arranged upside down, and is preferably 45 to 45 from the center of the detection area F. Arranged at an angle of 90 °.

  Further, in the pollen sensor 20, the light emitting means 1, the first light receiving means 2, and the second light receiving means 3 are set to be arranged on the same vertical plane, but may be arranged on the same horizontal plane.

  Further, although the semiconductor laser 6 is used as the light source of the light emitting means 1, the semiconductor laser 6 is not necessarily used, and an LED, a tungsten lamp, or the like may be used. However, semiconductor lasers emit light with a predetermined polarization direction, but LEDs, tungsten lamps, etc. emit light with a random polarization direction, so when using them, they are transmitted through a polarizing filter and have a predetermined polarization direction. It is necessary to change to light.

  Further, the matrix data described above indicate that the degree of polarization D ′ is “−1.0 or more and less than −0.9”, “−0.9 or more and less than −0.8”,. The intensity I ′ of the scattered light is “0.0 V or more and less than 0.5 V”, “0.5 V or more and less than 1.0 V”, and “7.5 V or more and 8.0 V or less”. However, matrix data other than those classified in this way may be used.

It is a side view of the pollen sensor which concerns on one Embodiment of this invention. It is a block diagram which shows an example of the processing method used for the pollen sensor of FIG. It is a figure which shows an example of the matrix used for the pollen sensor of FIG. It is a figure which shows the principle of the pollen sensor of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-emitting means 2 1st light-receiving means 3 2nd light-receiving means 4 Air suction port 5 Suction fan 6, 51 Semiconductor laser 7, 8, 10, 52, 53, 55 Lens 9, 12, 54, 57 Photodiode 11, 56 Polarization Filters 13 and 14 Current / voltage conversion circuits 15 and 16 Amplifying circuit 17 Identification means 19 Shading housing 20 Pollen sensor 60 Airborne particles

Claims (3)

A light emitting means for irradiating the air containing airborne particles with irradiation light in a predetermined polarization direction;
First light receiving means for detecting scattered light from the suspended particles and measuring the intensity I of the scattered light;
Second light receiving means for detecting scattered light in the polarization direction orthogonal to the polarization direction of the irradiation light among the scattered light caused by the suspended particles, and measuring the intensity Is of the orthogonal scattered light;
A pollen sensor comprising: an identification means for identifying pollen particles and dust based on the intensity I of the scattered light and the intensity Is of the orthogonal scattered light. The discriminating means performs discrimination based on one of the following degrees of polarization D1, D2, and D3 in which the intensity I of the scattered light and the intensity Is of the orthogonal scattered light are used, and the intensity I of the scattered light. The pollen sensor according to claim 1.
Polarization degree D1 = (I−Is) / (I + Is)
Degree of polarization D2 = (I−Is) / I
Polarization degree D3 = Is / I The discriminating means includes any one of the degree of polarization D1, D2, D3 and the intensity I of the scattered light, and one of the predetermined degrees of polarization D1, D2, D3, and the intensity of the scattered light. The pollen sensor according to claim 1 or 2, wherein a substance in a matrix composed of I is identified as pollen particles.

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