JPH0455740A - Corpuscle detecting apparatus - Google Patents

Abstract

PURPOSE:To make it possible to detect the state of corpuscle in a measuring fluid highly accurately by obtaining the extinction state of beam light only when the optical axis of the beam light is directed toward the region in the specified direction where the abnormal light which is generated by the emission of the light beam enters into a light receiving mechanism. CONSTITUTION:At least a part of a normal region 17b of light intensity in a beam-light applied region 17 is located in a part in the region of the field of view of a light receiving mechanism 14 in a flow path 1a through which measuring fluid 2 passes. When beam light 8 is deflected so as to scan the region 17, the light becomes the extinction state under the deflected state wherein the light 8 is cast on flow-path wall surfaces 1b and 1b in approximately parallel with the respective wall surfaces. Thus, only corpuscular-emitted light 11a which is emitted from the region 17b enters into the photoelectric converter 12. The abnormally emitted light from a flow cell does not enter into the converter. In this way, a detected signal 12a having the accurate corpuscular information is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention irradiates light onto a flowing measurement fluid containing a dilute amount of fine particles, and detects the scattering of this light by the fine particles and the light emitted from the fine particles based on the irradiation of the light. Measures the number and size of particles by receiving light emitted from particles such as fluorescence.

Information regarding the state of particulates in the measurement fluid, such as properties (hereinafter referred to as
This information is sometimes called particulate information. This invention relates to a particle detection device that can obtain accurate particle information within 1% of the time.

[Conventional technology]

FIG. 4 is a block diagram of a conventional particulate detection device filed by the present applicant (%Kokai No. 61 No. 288139 Publication No. 5).
(see Figure and Figure 7). In the figure, l indicates a channel 11 in which the measuring fluid 2 flows in a direction perpendicular to the paper surface of the figure, and the cross section of this channel 1 m is formed into a rectangle with a side length of approximately several hundred μm to several square meters. 70-cell, 3 is a light source such as a semiconductor laser device that emits a beam of light 4 as a parallel light flux with its optical axis 4a being within the plane of the drawing.

5 is provided with a photoacoustic deflector 28, and this deflector 28
The beam light 4 is incident on the optical axis 4 of the polarizer 28, and the structure and operation described below direct the incident beam light 4 to the polarizer 28.
A beam light deflecting section configured to emit a polarized light beam 6 having an optical axis 6m deflected with respect to a, and this deflecting section 5 further includes:

The beam is configured so that the optical axis 6 of the beam is repeatedly deflected back and forth in a fan-like manner within the plane of the paper of this figure.Thus, the beam 7 has an optical axis 7a within the plane of the paper of this figure and is incident. This is a focusing lens that focuses the beam light 6 in the vicinity of the center point O of the rectangular cross section of the channel 1a, and in FIG. The lens is made of, for example, non-fluorescent synthetic quartz, which is transparent and does not emit fluorescence even when irradiated with the beam light 8, and the lens optical axis 7 has a fi
ii! A pair of opposing channel wall surfaces 1b, 1 forming Im
%70 so that the virtual @B, -B, VC which is parallel to bec and also passes through the point O in the paper plane of this figure corresponds to
- Cell l and lens 7 are arranged.

Reference numeral 9 denotes a beam light irradiation mechanism consisting of a light source 3, a deflection section 5, and a lens 7.

In FIG. 4, since the cell 70 and the irradiation mechanism 9 are constructed as described above, the beam optical axis 6a is deflected by the deflector 28, so that the measurement fluid 2 is directed to the optical axis 8.
It is repeatedly irradiated in a straight line with the focused beam light 8 having the angle a. Reference numeral 10 denotes a condenser that collects particulate emitted light 11a such as scattered light and fluorescence emitted from particulates 11 in the fluid 2 by irradiating the fluid 2 with the beam light 8 outside the cell 70-1. The lens 12 receives the light 11a condensed by the lens 10, converts it into a current signal according to the amount of light received, and outputs a detection signal 121 in degrees Celsius.The photoelectric converter 8, 13 of the photodiode converts into a lens lO. an aperture disposed between the transducer 12 and the transducer 12 to limit the angle of incidence of light incident on the transducer 12, thereby suppressing stray light incident on the transducer 12;
is a light receiving mechanism consisting of a lens 10, an aperture 13, and a converter 12. 15 is a beam block that absorbs the beam 8 that has passed through the cell 70 to prevent stray light from entering the converter 12 due to this transmitted beam, and 16 is the beam block described above. This is a particle detection device consisting of various parts.

The detection device 16 is configured as described above, and a particle 11 is transported by the measuring fluid 2 to the irradiation area 17 shown in FIG. 5, when the fine particles II pass through the area 17, the fine particles 11 are irradiated many times with the beam light 8 which is oscillatorily deflected by the deflection unit 5, thereby detecting the detection in this case. Each part of the detection device 16 is configured so that the temporal waveform of the signal 12a becomes a pulse train waveform as shown in diagram M6, for example. FIG. 5 is an explanatory diagram illustrating the irradiation mode of the beam light 8 that passes through the 0 point in FIG. 4 and irradiates the virtual plane 18 perpendicular to the axes Bl-B, VC.

In this figure, A, -A are virtual axes passing through point O and perpendicular to the paper surface of FIG. 4, and P arrow is axis ^, =A.

4 shows the flow direction of the flat particles 11, and straight lines C and -C show the intersection lines of the virtual plane 18 and the paper surface of FIG. In the detection device 16&C, the beam polarizer 5 is configured as described above.

In addition, since the main part is configured so that the spot of the beam light 8 formed in the virtual plane 18 is approximately circular, the beam light 8 is eventually formed into the above-mentioned band-like shape with semicircular ends on the plane 18. The irradiation area 17 is irradiated repeatedly in the left and right direction, and in this case, the area 17 is irradiated with the axis fi! The main parts of the detection device 16 are configured to have a circular shape line-symmetrical with respect to AlAt. A substantially circular figure 19 shown in FIG. 5 is a beam spot formed by the #f:11 beam 8 on the plane 18 when the beam 8 is deflected to the farthest left 111c in FIG. The center point of the beam spot 19, which is the intersection of the optical axis 8a of the beam 8 and the plane 18, is the roughly circular figure 2 shown in FIG.
1 is a beam spot formed on the plane 18 by the beam 18 when the beam 8 is deflected to the rightmost side in FIG. The intersection point is the center point of the beam spot 21 at .degree.

It goes without saying that the semicircular portions at both ends of the irradiation area 17 are formed by beam spots 19.21.In the fist detection device 16, the beam light 8 is flat. 18 (Light intensity distribution at the beam spot to be formed.

The root strength up to the center point of the spot becomes stronger.

The light beam 8 is formed so as to exhibit a bell-shaped distribution characteristic that is point symmetrical with respect to the center point, and this bell-shaped q? For example, the light intensity distribution characteristic line 23 shown in FIG.
The pulse train waveform shown in FIG. 6 that appears in the envelope fifi!
24 indicates a shape corresponding to the characteristic line 23 shown in FIG.

In addition, in the detection device fa16, the number of particles 110 that crossed the irradiation area 17 can be determined from the number of pulse trains having the envelope 24 appearing in the detection number 128, and the maximum value of the envelope 24 can be determined. From this, it is possible to know the size, properties, etc. of the fine particles 11.

[Problem to be solved by the invention]

As described above, in the IC and the detection device fil 16 vc, information on particles in the fluid 2 is obtained by the detection signal 121.
As shown in FIG. 4, the voltage generator 25 generates a sawtooth wave voltage 25m, and when a voltage 25a is applied, outputs a high frequency voltage 26m having a frequency corresponding to the voltage value of the voltage 25a. It is composed of a voltage controlled oscillator 26, an amplifier circuit 27 that performs power amplification with respect to a high frequency voltage 26aK, and the aforementioned photoacoustic deflector 28, and the photoacoustic deflector 28 is also shown in FIG. , the output voltage 271 of the amplifier circuit 27 is applied, and a pressure is applied to emit an ultrasonic wave 29a having a frequency equal to the frequency of the voltage 27a as shown in the figure. Optical crystal such as tellurium dioxide as a medium 3
0, and an ultrasonic absorber 3 brought into contact with the crystal body 30 so as to absorb the ultrasonic wave 29a propagated through the crystal body 30.
It consists of engineering and engineering. Then, the crystal body 30 mentioned above.

Among them, FIf3 has a coarse V like ultrasonic 29H! When a parallel light beam such as the light beam 4 enters the crystal body 30 from a direction that is not perpendicular to the direction of propagation of the compressional waves in the presence of waves, the compressional waves act as a diffraction grating and the incident parallel light is It inherently has the property of emitting a light beam as a parallel light beam deflected in a direction according to the wavelength of the compression wave, and in FIG. 4, the beam optical axis 48 is perpendicular to the traveling direction of the ultrasonic wave 29H. When the light beam 4 is incident on the crystal body 30 so as to intersect at an angle other than that of the crystal body 30, and when this light beam 4 is incident on the crystal body 30Vc, it has an optical axis 6m having a direction according to the wavelength of compression waves existing in the crystal body. The light source 3 and the polarizing section 5 are configured such that the polarized beam 6 is emitted from the crystal body 30.

That is, in the detection device [161C], since the light source 3° deflection section 5 and the lens 7 are each configured as described above, the frequency of the high frequency voltage 27a changes periodically, and therefore the deflection of the beam light 6 changes. As a result of periodic changes in direction,
As mentioned above, the focused light beam 8 will repeatedly irradiate the irradiation area 17 in FIG. Crystal body 3 in the time period of
It is clear that a state occurs in which the wavelength of the ultrasonic compression wave changes rapidly and significantly within 0.

Then, when such a sudden and large wavelength change of compression waves appears in the crystal body 30, wave interference occurs, resulting in a phenomenon in which the diameter of the beam spot of the beam light 8 at the temporary convergence plane 18rc changes. As a result, the light intensity at the beam spots 19, 21 and the irradiation area 170 near these spots shown in FIG. . Such changes in the diameter of the beam spot and changes in light intensity become more pronounced as the deflection speed of the light beam 8 increases, and therefore, the light intensity in the irradiation area 17 becomes abnormal compared to near the zero point. The abnormal light intensity region 17B increases as the deflection speed of the light beam 8 increases, and as a result, the region 171
The light intensity normal region 17b excluding the above-mentioned light intensity abnormal region 17a in r-.

The light intensity normal region range H, which is represented by the length on straight lines C and -C in FIG. 5, decreases as the deflection speed of the two-beam light 8 becomes faster. In FIG. 4, it is clear that if the deflection speed of the beam light 8 is increased, the particle 11 can be detected by the detection signal 12m even if the flow speed in the 70-cell IK of the measurement fluid 2 is increased. When inspecting the existence state of particles 11 in the fluid 2 by using
It will be set according to the volume of.

Now, in the detection device 16, as is clear from the above, there are more or less abnormal light intensity regions 17a within the beam light irradiation region 17.

Therefore, if the detection device 16 is configured such that all of the irradiation area 17 exists within one cell flow path 70 and all of this area 17 also exists within the field of view of the light receiving mechanism 14, the photoelectric converter The particulate emitted light 11m incident on 12rc includes light emitted from the abnormal light intensity region 17M and light emitted from the normal light intensity region 17b. It is clear from the above that the signal 121 cannot correctly represent at least the size of the particle 11, so in this case, the detection signal 12arc will contain incorrect particle information, and therefore the above configuration will not work. The particle detection device 16 has a problem in that the particle information obtained from the detection signal 121 is inaccurate.

Therefore, in the particle detection device 16, only the light intensity normal region 17b exists in the 70-cell flow path Ia, and at least all the light intensity abnormal regions 171 exist outside the 70-cell flow path la. In addition to setting the beam light irradiation area 17 to
If the mechanism 14 is formed so that the mechanism 14 exists within the field of view of If the button is closed so that only the light 11a enters the photoelectric converter 12, the detection signal 12arr
, does not contain erroneous particle information, but in reality, in this case, the irradiation area I7 is directly #Ct in FIG.
When the beam light 8 scanning left and right along Ct is deflected to irradiate the IIt channel wall surfaces 1b and lb almost parallel to each wall surface, 70-the constituent materials of the cell 1 and the channel 1a
Based on the difference in refractive index between the inner fluid 2 and the fluid 2 (intense scattered light, etc. occurs), these lights (hereinafter these lights may be referred to as 70-cell abnormal emitted light) are considered to be stray light. Therefore, while the beam light 8 scans the irradiation area 17 from one end to the other end, the detection signal 121Vc
is a signal pulse based on the particle emitted light 11jliC, and there appears one signal pulse that constitutes the pulse train in FIG. In this case, since the 8N ratio in the signal 12m deteriorates, the particle detection device 16 having such a configuration also has the problem that it is impossible to obtain accurate particle information from the signal 1211.

The object of the present invention is to include a portion of the flow path 1a through which the measurement fluid 2 flows, which exists within the visual field of the light receiving mechanism 14.
When the light beam 8 is deflected to scan the irradiation area 17, the light beam 8 at least flows In the deflection state in which the road wall surfaces 1b and lb are irradiated almost parallel to each wall surface.

By causing this light 8 to be in an extinguished state, only the particulate emitted light 11a emitted from the normal light intensity region 17b enters the photoelectric converter 12, and the abnormal emitted light from the cell 70 does not enter the photoelectric converter 12. The object is to make it possible to obtain a detection signal 12a having accurate particle information.

[Means to solve the problem]

In order to achieve the above objects, the present invention provides a beam that emits a light beam and deflects the optical axis so that the optical axis of the light beam repeatedly reciprocates on the same virtual plane across a flowing measuring fluid. A light-emitting mechanism, and a light-receiving mechanism that receives particulate emitted light and outputs a detection signal according to the amount of received light based on the irradiation of the # beam light, and detects particulates in the measurement fluid by the detection signal. The beam emitting mechanism is a particulate detection device for detecting particles, and the beam emitting mechanism detects the beam only when the optical axis of the beam is directed to a predetermined direction area where abnormal light generated by the irradiation of the beam light is likely to enter the light receiving mechanism. The particle detection device is configured to put the beam light in an extinguished state.

[Effect]

With the above configuration, at least a part of the part of the measurement fluid irradiated by the beam light whose optical axis is directed outside the predetermined direction area is within the normal light intensity area 17b in the beam light irradiation area 17, and this area The light-receiving mechanism can receive the particulate emission light emitted from at least a part of the part of the measurement fluid in 17b, and furthermore, the irradiation with the two-beam light can cause the particulate emission light to be emitted from at least a part of the part of the measurement fluid in 17b. When abnormal light is generated, the optical axis of the beam can be set to be directed within a predetermined direction area. Since only the particle emitted light is incident and no abnormal light is incident, a detection signal having accurate particle information can be obtained.

c′#i line example] FIG. 1 shows a particulate detection device 34 as an example of the present invention.
What is the difference between this diagram and the one shown in Figure 4?

A beam light emitting mechanism 32 is provided in place of the beam light emitting mechanism 9 in FIG. 4, and a beam light control signal 35 is provided as a binary signal having binary values of H level and L level.
g is input and signal 35 is at H level, the fourth
The light source 33 emits the light beam 4 in exactly the same manner as in the figure toward the photoacoustic deflector 28, and turns the light beam 4 into an extinction state when the signal 3511 is at the L level. In this case, the first
As shown in FIG. 2, which is an enlarged explanatory view of the main part of the figure, the position and size of the light intensity normal region range H in the beam light irradiation area 17 in the virtual plane 18 shown in FIG. It is set to include the distance W between the channel wall surfaces 1b and Ib (hereinafter, this distance may be referred to as the width of the channel 1a).

Furthermore, the related parts are configured such that all of the normal light intensity region 17b within this range H exists within the visual field of the light receiving mechanism 14. In FIG. 2, the same parts as in FIG. 5 are given the same reference numerals as in FIG. 5, and in FIG. Beam spot 19 shown in .
Deflection that generates 21 respectively! 1 shows the beam light 8, and 83 shows the beam light 8 in a predetermined deflection state as close as possible to the left channel wall surface 1b without producing the above-mentioned 70-cell abnormal output light. ,
Further, the arrow 84 indicates the beam light 8 in a predetermined deflection state as close as possible to the right channel wall surface 1b without producing the above-mentioned 70-cell abnormally emitted light.

2 In FIG.
and the light source 3 described above.
3. In this case, it is composed of a beam polarizer 5 and a condenser lens 7.

The sawtooth wave voltage 25a is the lowest voltage V. ■ and maximum voltage Voh
As shown in FIG. 3, the beam light controller 35 changes over time as shown in FIG. 3, and as shown in FIG. L
The output voltage 251 of the level signal 3511 is set to a predetermined level.
The L level of the signal 35a is maintained until the limit voltage v1trc rises, but when the It pressure 25a rises from vot and reaches the 1 limit voltage V, t[, it outputs the H level signal 35a and then the tit pressure 25a The signal 35a is held at the H level until the voltage 25a rises to a predetermined upper limit voltage Vxh, and when the voltage 25a further rises from vlt and reaches Vth, it becomes low again.
After outputting the level signal 35m, the IT pressure 25a becomes the voltage V
. h.

The voltage V1. The signal 351 is kept at the L level until it reaches . Then, in the particle detector g134 shown in Figure 1, the voltage 25a is V. When the voltage 25a is Voh, the light beam 8 becomes the light beam 82 shown in FIG. 2. When the voltage 25a is Vlt, the light beam 8 becomes the light beam 81 shown in FIG. The main parts are configured so that when the voltage 251 is Vlh, the light beam 8 becomes the state of the light beam 84 shown in FIG. 2.

In the detection device 34, each part is configured as described above, so that the light beam 8 is divided into the light beams 83 and 83 in FIG.
While the light beam 8 is deflected from the state to the state of the beam light 84, the light beam 8 is in a lighting state in which the light beam 8 irradiates the fluid 2 to be measured.
The beam 8 is in an extinguished state during the period from the 1st dip to the OK deflection of the beam 83 and from the state of the beam 84 to the 11rc deflection of the beam 82. Therefore, in the case of the detection device 34, it is clear that the above-mentioned 70-cell abnormal emitted light does not occur when the beam light 8 is in a deflected state that can irradiate the entire surface of the channel wall surfaces 1b, 1b substantially parallel to each other. Gade.

In this case, the photoelectric converter 12 also has a normal light intensity region 1.
Particle emitted light 1 emitted from the measurement fluid 2 in 7b
It is clear that only 11 is incident. Therefore, according to the detection device 34, accurate particulate information can be obtained from the detection signal 121.

〔Effect of the invention〕

As described above, in the present invention, the VC emits a light beam and deflects the optical axis so that the optical axis of the light beam repeatedly reciprocates on the same plane across a flowing measuring fluid. and a light receiving mechanism that receives particulate emitted light based on the irradiation of the # beam light and outputs a detection signal according to the amount of received light, and detects particulates in the measurement fluid based on the detection signal. The light beam emitting mechanism extinguishes the light beam only when the optical axis of the light beam is directed to a predetermined direction region where abnormal light generated by irradiation with the light beam may enter the light receiving mechanism. The particulate detection device was configured so as to

Therefore, with the above configuration, at least a part of the part of the measurement fluid irradiated by the beam light whose optical axis is directed outside the predetermined direction area is within the light intensity normal area 17b in the beam light irradiation area 17. In addition, the light receiving mechanism can receive the particle emitted light emitted from at least a part of the portion of the measurement fluid in this region 17b, and in addition, the above-mentioned 70-cell abnormality can be detected by irradiation with the beam light. When abnormal light such as emitted light is generated, the optical axis of the beam light can be directed within a predetermined direction region, so in such a particle detection device, the light receiving mechanism has a light intensity normal region 17b. Since only the particulate emitted light emitted from the particle enters and no abnormal light enters, a detection signal having accurate particulate information is obtained, and in the end, this detection signal is used in the present invention. This has the effect that the state of particulates in the measurement fluid can be detected with high precision.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a refreshing embodiment of the present invention. FIG. 2 is an enlarged explanatory diagram of the main parts in FIG. 1. FIG. 3 is an explanatory diagram of the temporal waveforms of the main parts of the signals in FIG. 1. FIG. 4 is a configuration diagram of a conventional particle detection device. FIG. 5 is an explanatory diagram of the operation of the particle detection device shown in FIG. 4. FIG. 6 is an explanatory diagram of the temporal waveforms of the main parts of the signals in FIG. 4. 2...Measurement fluid, 8...Focused beam light (beam light). 8...optical axis, 11...fine particles, lla...
...Particle emission light, 12a...Detection signal, 14...Light receiving mechanism, 32...Beam light emission mechanism, 34...Particle detection Attire! , 811
Shiki-gun - 3 moxibustion deogi I. 51 Notebook Closed Notebook Bacteria

Claims (1)

[Claims] 1) A beam light emitting mechanism that emits a beam light and deflects the optical axis so that the optical axis of the beam light repeatedly reciprocates on the same virtual plane across a flowing measuring fluid; and a light receiving mechanism that receives the original particulate emission light and outputs a detection signal according to the amount of received light, and detects particulates in the measurement fluid based on the detection signal, the particulate detection device detecting particulates in the measurement fluid, The mechanism is characterized in that the light beam is extinguished only when the optical axis of the light beam is directed to a predetermined direction area where abnormal light generated by irradiation of the light beam may enter the light receiving mechanism. A particulate detection device.