JPH11211650A - Particle passage position detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the scattering light intensity of a particle from differing even if the particle diameter or the like of the particle is the same depending on the passage position of the particle at a measurement region where laser beams are applied. SOLUTION: A detection device is provided with a flow cell 1 that is formed by a transparent member so that it is flexed, a laser light source 2 for forming a measurement region M by applying laser beams La to a straight line channel 1a of the flow cell 1, a condensation optical system 3 that has a light axis being matched to the center axis of the straight line channel 1a and condenses scattered light Ls of a particle being generated by the measurement region M, a light detection means 4 consisting of three optoelectric conversion elements 4a, 4b, and 4c for receiving the scattered light Ls being condensed by the condensation optical system 3, peak value detection means 6a, 6b, and 6c for detecting peak values Ea, Eb, and Ec of the output voltage of the three optoelectric conversion elements 4a, 4b, and 4c, and a position detection means 7 for comparing the output voltages Ea, Eb, and Ec of the peak value detection means and outputting the passage position information of the measurement region M where the particle passed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting a passing position of particles, for example, a particle passing position detecting apparatus applied to a particle counting device for counting the number of particles passing through a channel by discriminating the particle size. Related to the device.

[0002]

2. Description of the Related Art As a conventional particle counting apparatus, as shown in FIG. 18, a laser beam La is applied to an internal flow path of a flow cell 100, and the particles are emitted when the particles pass through the internal flow path. The scattered light Ls is condensed on the photoelectric conversion element 102 by the condensing optical system 101, and based on the output signal of the photoelectric conversion element 102, the comparison circuit 103 and the pulse counting circuit 10
No. 4, there is known a light scattering type particle counting device which counts the number of particles passing through an internal flow path by discriminating the particle diameter.

[0003] When particles pass through the internal flow path, the photoelectric conversion element 102 outputs a pulse-like voltage corresponding to the scattered light Ls emitted by the particles. The peak value of this pulsed voltage is
It depends on the particle size. The comparison circuit 103 compares the output voltage of the photoelectric conversion element 102 with a predetermined value, and when the output voltage of the photoelectric conversion element 102 is larger than the predetermined value, outputs a pulse signal that the output voltage is larger than a predetermined particle size. The pulse signal is counted by the pulse counting circuit 104 to detect the number of particles.

[0004]

However, in the light scattering type particle counting apparatus shown in FIG. 18, when the laser light intensity of the internal flow path irradiated with the laser light La is not constant, the discrimination of the particle diameter is erroneously counted. There is a problem of doing. The laser beam intensity of the internal flow path is generally highest in the center of the laser beam,
In many cases, the distribution becomes lower (approximately Gaussian distribution) as the distance from the center to the end is lower.

Therefore, even if the particles have the same particle size and optical properties, the intensity of the scattered light Ls of the particles differs between passing through the end of the laser beam and passing through the center thereof. The output voltage of the photoelectric conversion element 102 is different. Therefore, the output signal of the comparison circuit 103 is different, and the pulse counting circuit 104 may or may not count particles.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to solve the conventional problems if the passing position of the particles is known. The present invention aims to provide a particle passage position detecting device capable of detecting the position of a flow path through which particles pass by paying attention to.

[0007]

According to a first aspect of the present invention, there is provided a flow cell having a bent shape formed of a transparent member, and a flow path of the flow cell is irradiated with laser light to form a measurement area. A laser light source, a condensing unit having an optical axis coinciding with the center axis of the flow path, and condensing scattered light of particles generated in the measurement region, and a scattered light collected by the condensing unit. A light detecting means comprising a plurality of photoelectric conversion elements for receiving light; a voltage detecting means for detecting output signals of the plurality of photoelectric conversion elements; an output signal of the voltage detecting means; Is provided with position detecting means for outputting the passing position information.

According to a second aspect of the present invention, in the particle passing position detecting device according to the first aspect, the light detecting means comprising the plurality of photoelectric conversion elements is arranged such that each light receiving surface is perpendicular to the center axis of the flow path, and This is a photoelectric conversion element array including N (N is an integer of 2 or more) photoelectric conversion elements provided adjacent to a center axis of the flow path and a direction substantially perpendicular to the laser optical axis.

According to a third aspect of the present invention, in the particle passing position detecting apparatus according to the first aspect, the light detecting means comprising the plurality of photoelectric conversion elements has V × H (vertical and horizontal) (both V and H). (An integer of 2 or more) photoelectric conversion elements, and each light receiving surface is perpendicular to the center axis of the flow path.

According to a fourth aspect of the present invention, there is provided a flow cell formed of a transparent member, a laser light source for irradiating a flow path of the flow cell with laser light to form a measurement region, and a light coincident with the central axis of the laser light. A condensing means having an axis for condensing the scattered light of the particles generated in the measurement region, a trap positioned on the optical axis of the condensing means, and receiving the scattered light condensed by the condensing means Light detection means comprising a plurality of photoelectric conversion elements, and voltage detection means for detecting the output signals of the plurality of photoelectric conversion elements, and comparing the output signals of the voltage detection means with each other to detect the measurement area of the measurement area where the particles have passed. It is provided with position detecting means for outputting passage position information.

According to a fifth aspect of the present invention, in the particle passing position detecting device according to the fourth aspect, the light detecting means comprising the plurality of photoelectric conversion elements is arranged such that each light receiving surface is perpendicular to the laser optical axis, and Is a photoelectric conversion element array composed of N (N is an integer of 2 or more) photoelectric conversion elements provided adjacent to each other in a direction substantially perpendicular to the central axis of the laser beam.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 shows a first embodiment of the present invention.
FIG. 2 is a plan view of a measurement area irradiated with laser light in FIG. 1, and FIG. 3 is a longitudinal sectional view of a measurement area irradiated with laser light in FIG. 4 to 8 show the light receiving state (a) of the photoelectric conversion element array and the output waveform (b) at that time in FIG. 1, FIG. 9 shows a particle information reference table, and FIG. 10 shows the present invention. FIG. 11 is a configuration diagram of a particle passage position detection device according to a second embodiment, FIG. 11 is a configuration diagram of a particle passage position detection device according to a third embodiment of the present invention, and FIG. FIG. 13 to FIG. 17 are diagrams showing the light receiving state (a) of the photoelectric conversion element array and the output waveform (b) at that time in FIG.

As shown in FIG. 1, a particle passing position detecting apparatus according to a first embodiment of the present invention comprises a flow cell 1, a laser light source 2, a condensing optical system 3, a photoelectric conversion element array 4, and a processing device 5. Consists of

The flow cell 1 is made of a transparent member, has a straight flow path 1a of a predetermined length, and is bent as a whole.
The flow cell 1 has a rectangular cross section and is formed as an L-shaped cylinder as a whole. The center axis of the straight flow path 1a coincides with the X direction.

The reason for providing the straight flow path 1a having a predetermined length is as follows.
This is because, when the test fluid flows through the flow cell 1, the flow of the test fluid becomes laminar. The conditions for obtaining the laminar flow include the viscosity of the test fluid, the length of the straight flow path, the cross-sectional shape and flow velocity of the flow path, and the like, and the length of the straight flow path 1a and the cross-sectional shape of the flow path. Is determined in consideration of the viscosity and flow rate of the test fluid.

The laser light source 2 irradiates a predetermined portion of the linear flow path 1a of the flow cell 1 with a laser beam La to form an irradiation area. Here, the optical axis of the laser beam La coincides with the Z direction and is orthogonal to the central axis of the straight flow path 1a coincident with the X direction.

Further, as shown in FIG. 2, the angle between the optical axis of the laser beam La and the outer wall of the flow cell 1 may be set to a predetermined angle θ. This is to prevent the laser light La from being reflected on the outer wall of the flow cell 1 and part of the reflected light returning to the laser light source 2. This is because, when a part of the reflected light returns to the laser light source 2, the feedback noise is undesirably superimposed on the laser light La.

In order to prevent the laser beam La from being reflected by the outer wall of the flow cell 1, for example, if the laser beam La can be guided to a predetermined portion of the linear flow path 1a through the same material as the outer wall of the flow cell 1, the predetermined angle θ is set. No need to set.

The condensing optical system 3 has an optical axis coinciding with the central axis of the straight flow path 1a of the flow cell 1, and has a predetermined area M (hereinafter referred to as a measurement area M) in the irradiation area shown in FIG. Has a function of condensing scattered light Ls emitted from particles that have received the laser light La.

The photoelectric conversion element array 4 includes three photoelectric conversion elements 4a, 4b, and 4c, each light receiving surface being perpendicular to the center axis of the flow path, and the center axis (X direction) of the flow path and the laser light. It is provided adjacent to the Y direction perpendicular to the axis (Z direction).
The photoelectric conversion elements 4a, 4b, and 4c convert scattered light Ls emitted while particles pass through the measurement region M into a voltage.

The optical axis of the laser beam La and the flow cell 1
When the angle formed by the outer wall of the photoelectric conversion elements 4a, 4b, and 4c is set to a predetermined angle θ shown in FIG.
The light collecting optical system 3 may be inclined by a predetermined angle θ with respect to a plane perpendicular to the optical axis.

The processing unit 5 detects peak values (pulse heights) Ea, Eb, and Ec of voltages output by the three photoelectric conversion elements 4a, 4b, and 4c while the particles pass through the measurement area M. It comprises value detecting means 6a, 6b, 6c and position detecting means 7 for creating a particle information reference table.

In the first embodiment of the present invention, as voltage detecting means, peak value detecting means 6a, 6b for detecting peak values Ea, Eb, Ec of voltages output from photoelectric conversion elements 4a, 4b, 4c, respectively. , 6c, but not necessarily peak values, for example, photoelectric conversion elements 4a, 4b, 4c.
The output voltage of c may be detected at the same timing, and the output voltage may be used in the subsequent arithmetic processing. Further, as the voltage detecting means, the output voltages of the photoelectric conversion elements 4a, 4b, 4c may be integrated and output for a predetermined time.

The position detecting means 7 includes an arithmetic unit 7a and a storage unit 7
b. First, the arithmetic unit 7a performs the following arithmetic processes (1) and (2), stores the result in the storage unit 7b, and creates a particle information reference table. (1) The ratio Ea / Eb of the output voltage Ea of the peak value detecting means 6a to the output voltage Eb of the peak value detecting means 6b is calculated. (2) The ratio Ec / Eb of the output voltage Ec of the peak value detecting means 6c to the output voltage Eb of the peak value detecting means 6b is calculated.

The operation of the particle passing position detecting device according to the first embodiment of the present invention configured as described above will be described. Since it is necessary to know the laser light intensity distribution in the measurement area M in advance, a method for measuring the laser light intensity distribution in the measurement area M will be described.

As shown in FIG. 3, a fluid containing a large number of standard particles (having the same particle size) is poured into the flow cell 1 from the direction of arrow A. At this time, the output waveform of each photoelectric conversion element 4a, 4b, 4c of the photoelectric conversion element array 4 varies depending on which position in the measurement area M the standard particle passes. Then, the three photoelectric conversion elements 4a, 4b, 4
In the case of the photoelectric conversion element array 4 made of c, there are five main types of passing patterns.

First, the standard particles are placed in the measurement area M shown in FIG.
, The light scattered by the standard particles L
The spot S of s appears only on the photoelectric conversion element 4b at the center of the photoelectric conversion element array 4, as shown in FIG.
At this time, the output waveform (relationship between time t and voltage E) of each of the photoelectric conversion elements 4a, 4b, 4c is as shown in FIG. That is, only the photoelectric conversion element 4b outputs a substantially pulse-like voltage (peak value Eb) corresponding to the scattered light Ls of the standard particles passing through the center Mc of the measurement region M for a certain time (from time t1 to time t2). However, the other photoelectric conversion elements 4a and 4c output only approximately level voltages (peak values Ea and Ec) corresponding to the noise.

Next, the standard particles are measured in the measurement area M shown in FIG.
5A, the spot S of the scattered light Ls by the standard particles appears only on the photoelectric conversion element 4a at one end of the photoelectric conversion element array 4, as shown in FIG. At this time, the output waveform (relationship between time t and voltage E) of each of the photoelectric conversion elements 4a, 4b, 4c is as shown in FIG. That is, only the photoelectric conversion element 4a has the measurement area M
And outputs a substantially pulse-like voltage (peak value Ea) corresponding to the scattered light Ls of the standard particles passing for one time Ms from time t3 to time t4.
4c is a substantially level voltage (peak values Eb, Eb) corresponding to the noise.
Output only c).

Similarly, when the standard particles pass through the other end Ms (symmetrical to the one end Ms) of the measurement area M shown in FIG. 3, the spot S of the scattered light Ls by the standard particles is shown in FIG.
As shown in (a), it appears only in the photoelectric conversion element 4c at the other end of the photoelectric conversion element array 4. At this time, the output waveform (relationship between time t and voltage E) of each of the photoelectric conversion elements 4a, 4b, 4c is as shown in FIG. That is, only the photoelectric conversion element 4c passes through the other end portion Ms of the measurement area M for a certain period of time (from time t3 to time t4).
A substantially pulse-shaped voltage (peak value Ec) corresponding to s is output, and the other photoelectric conversion elements 4a and 4b output only a substantially level voltage (peak values Ea and Eb) corresponding to noise.

Further, when the standard particles are in the measurement area M shown in FIG.
7, the spot S of the scattered light Ls due to the standard particles appears over the boundary between the photoelectric conversion element 4a and the photoelectric conversion element 4b as shown in FIG. 7A. At this time, the output waveform (relationship between time t and voltage E) of each of the photoelectric conversion elements 4a, 4b, 4c is as shown in FIG. 7B. That is, the photoelectric conversion elements 4a and 4b move along one path Mm of the measurement area M for a certain period of time (from time t5 to time t6).
And outputs substantially pulse-like voltages (peak values Ea and Eb) corresponding to the scattered light Ls of the standard particles passing through the photoelectric conversion element 4.
c outputs only a substantially level voltage (peak value Ec) corresponding to the noise.

Similarly, when the standard particles pass through another path Mm of the measurement area M shown in FIG. 3 (symmetric with one path Mm), the spot S of the scattered light Ls by the standard particles is shown in FIG.
As shown in (a), it appears over the boundary between the photoelectric conversion element 4b and the photoelectric conversion element 4c. At this time, the output waveform (relationship between time t and voltage E) of each of the photoelectric conversion elements 4a, 4b, 4c is as shown in FIG. That is, a substantially pulse-shaped voltage (peak value Eb, Pb) corresponding to the scattered light Ls of the standard particles that the photoelectric conversion elements 4b, 4c pass through the other path Mm of the measurement area M for a certain period of time (from time t5 to time t6). E
c), and the photoelectric conversion element 4a outputs only a substantially level voltage (peak value Ea) corresponding to the noise.

Then, in the position detecting means 7, FIG.
When the spot S appears only in the center photoelectric conversion element 4b as shown in FIG.
The ratio Ea / Eb of the peak voltage Ea of the photoelectric conversion element 4a to the peak voltage Eb of b is calculated, and since Ea <Eb, a value of almost zero (Ea / Eb ≒ 0) is output as the ratio Ea / Eb; It is stored in the storage unit 7b. The operation unit 7a
, The ratio Ec / Eb of the peak voltage Ec of the photoelectric conversion element 4c to the peak voltage Eb of the photoelectric conversion element 4b is calculated, and since Ec <Eb, the ratio Ec / Eb is substantially zero (Ec / Eb ≒ 0). The value is output and stored in the storage unit 7b.

In the position detecting means 7, as shown in FIG. 5A, the spot S is applied only to the photoelectric conversion element 4a at one end.
Appears in the arithmetic unit 7a, the photoelectric conversion element 4b
The ratio Ea / Eb of the peak voltage Ea of the photoelectric conversion element 4a with respect to the peak voltage Eb is calculated, and since Ea> Eb, a very large value (Ea / Eb ≒) is obtained as the ratio Ea / Eb.
∞) is output and stored in the storage unit 7b. Similarly, the photoelectric conversion element 4c with respect to the peak voltage Eb of the photoelectric conversion element 4b
Calculate the ratio Ec / Eb of the peak voltage Ec of
Therefore, the ratio Ea / Eb is about 1 (Ea / Eb ≒).
The value of 1) is output and stored in the storage unit 7b.

In the position detecting means 7, as shown in FIG. 6 (a), the spot S is applied only to the photoelectric conversion element 4c at the other end.
Appears in the arithmetic unit 7a, the photoelectric conversion element 4b
The ratio Ea / Eb of the peak voltage Ea of the photoelectric conversion element 4a to the peak voltage Eb is calculated, and since Ea ≒ Eb, a value of about 1 (Ea / Eb ≒ 1) is output as the ratio Ea / Eb and stored. The information is stored in the unit 7b. Similarly, the ratio Ec / Eb of the peak voltage Ec of the photoelectric conversion element 4c to the peak voltage Eb of the photoelectric conversion element 4b is calculated. Since Ec> Eb, a very large value (Ec / Eb) is obtained as the ratio Ec / Eb.
≒ ∞) is output and stored in the storage unit 7b.

Next, in the position detecting means 7, as shown in FIG. 7A, when the spot S appears over the boundary between the photoelectric conversion element 4a and the photoelectric conversion element 4b, the photoelectric conversion is performed by the arithmetic unit 7a. The ratio Ea / Eb of the peak voltage Ea of the photoelectric conversion element 4a to the peak voltage Eb of the element 4b is calculated. Since Ea ≒ Eb, the ratio Ea / Eb is about 1
The value of (Ea / Eb ≒ 1) is output and stored in the storage unit 7b. Similarly, the ratio Ec / Eb of the peak voltage Ec of the photoelectric conversion element 4c to the peak voltage Eb of the photoelectric conversion element 4b is calculated. Since Ec <Eb, the ratio Ec / Eb is almost zero (Ec / Eb ≒ 0). Is output and stored in the storage unit 7b.

In the position detecting means 7, as shown in FIG. 8 (a), when the spot S appears over the boundary between the photoelectric conversion element 4b and the photoelectric conversion element 4c, the photoelectric conversion element The ratio Ea / Eb of the peak voltage Ea of the photoelectric conversion element 4a to the peak voltage Eb of 4b is calculated, and since Ea <Eb, a value of almost zero (Ec / Eb ≒ 0) is output as the ratio Ea / Eb, It is stored in the storage unit 7b. Similarly, the ratio Ec / Eb of the peak voltage Ec of the photoelectric conversion element 4c to the peak voltage Eb of the photoelectric conversion element 4b.
Is calculated, and since Ec ≒ Eb, a value of about 1 (Ec / Eb ≒ 1) is output as the ratio Ec / Eb and stored in the storage unit 7b.

Note that the reference voltage is the photoelectric conversion element 4
photoelectric conversion elements 4a and 4c other than the peak voltage Eb
Or the sum of the peak voltages (Ea + Eb + Ec). The point is not the absolute value of the peak voltage of the photoelectric conversion elements 4a, 4b, 4c, but the spot S of the scattered light Ls by the standard particles based on the ratio (ratio) of the peak voltage of each of the photoelectric conversion elements 4a, 4b, 4c to the reference voltage. This is because the accuracy is higher when the position is obtained.

For the above five cases, FIG.
As shown in (5), a particle information reference table can be created when the reference voltage is the peak voltage Eb of the photoelectric conversion element 4b. Therefore, the ratio Ea / Eb of the peak voltage Ea of the photoelectric conversion element 4a to the peak voltage Eb of the photoelectric conversion element 4b.
If the ratio Ec / Eb of the peak voltage Ec of the photoelectric conversion element 4c to the peak voltage Eb of the photoelectric conversion element 4b is known, the passing position of the particles in the measurement region M in the Y direction can be determined by referring to the particle information reference table. It can be identified from among five ways.

In addition to the above-mentioned five kinds of passing patterns, spots S on the boundary between the photoelectric conversion element 4a and the photoelectric conversion element 4b or on the boundary between the photoelectric conversion element 4b and the photoelectric conversion element 4c.
, The ratio Ea / Eb of the peak voltage Ea of the photoelectric conversion element 4a to the peak voltage Eb of the photoelectric conversion element 4b and the photoelectric conversion element Ratio Ec / E of peak voltage Ec of photoelectric conversion element 4c to peak voltage Eb of peak 4b
If b is known, the position of the particle in the measurement area M in the Y direction can be identified by applying the value of the ratio Ea / Eb and the value of the ratio Ec / Eb to the particle information reference table.

The particle passage position detecting device according to the second embodiment of the present invention has a flow cell 1 as shown in FIG.
1, laser light source 12, condensing optical system 13, light detection means 14
And a processing device 15. Here, the flow cell 11,
The laser light source 12 and the condensing optical system 13 have the same configuration as that shown in FIG.

The light detecting means 14 has a vertical (Y direction) and a horizontal (Z
3) x 3 matrix-shaped photoelectric conversion elements D
_{11, D 12, D 13,} D 21, consists ...... D _33, the light receiving surface forms a vertical Y · Z plane to the central axis of the flow channel 11a (X direction).

The processor 15, three × 3 pieces of photoelectric conversion elements _{D 11, D 12, D 13} , D 21, ...... peak value E ₁₁ of each of the output voltage of the _{D 33, E 12, E 13} , E _21, ...... peak value detecting means 16a for detecting the E _33, 16b, 16c and the peak value _{E 11, E 12, E 13} , E 21, position detecting means for detecting the position of the particle from ...... E ₃₃ 17 Consists of

The peak value detecting means 16a is a photoelectric conversion element D
₁₁ , D ₁₂ , and D ₁₃ are time-divisionally sampled to detect their peak values E ₁₁ , E ₁₂ , and E ₁₃ , and the peak value detecting means 16b detects the peak values of the photoelectric conversion elements D ₂₁ , D ₂₂ , and D ₂₃ . The output voltage is sampled in a time-division manner and its peak values E ₂₁ , E ₂₂ ,
Detecting the E _23, a peak value detecting means 16c detects the photoelectric conversion element D _31, D _32, the peak value is sampled in a time division output voltage of the _{D 33 E 31, E 32,} E 33.

Note that the peak value detecting means is a photoelectric conversion element D
₁₁ , D ₁₂ , D ₁₃ , D ₂₁ ,..., D ₃₃ may be provided, and the peak value may be detected by constantly sampling the output voltage due to the scattered light Ls of the particles passing through the measurement area M at a certain time. . Further, the voltage detecting means is not necessarily a peak value, and may be, for example, photoelectric conversion elements D ₁₁ , D ₁₂ , D ₁₃ , D ₂₁ ,.
The output voltage of the D ₃₃ may be detected at the same timing.
Further, as voltage detecting means, the photoelectric conversion elements 4a, 4b,
The output voltage of 4c may be integrated and output for a predetermined time.

The position detecting means 17 comprises a calculating part 17a and a storage part 17b. First, in the calculating part 17a, the peak value E detected by the peak value detecting means 16a, 16b, 16c is detected.
_{11, E 12, E 13,} E 21, one voltage among ...... E ₃₃ (e.g., a peak value E ₂₂₎ is selected, the ratio of the other peak values, based on the voltage (E ₁₁ / E ₂₂ , E ₁₂ / E ₂₂ ...) Are calculated, and the result is stored in the storage unit 17b to create a particle information reference table similar to that of FIG.

[0046] Further, the calculating unit 17a, the peak value detecting means 16a, 16b, 16c peak value E ₁₁ which _{detects, E 12, E 13, E} 21, selects the largest peak value among ...... E ₃₃ The result may be stored in the storage unit 17b.

The operation of the particle passing position detecting device according to the second embodiment of the present invention will be described. As shown in FIG. 10, a fluid containing particles flows into the flow cell 11 from the direction of arrow A. At this time, the photoelectric conversion elements D ₁₁ , D ₁₂ , D ₁₃ , D ₂₁ ,... Of the light detecting means 14 depend on which position in the measurement area M the particles pass through.
The output waveform of the D ₃₃ is a different one.

[0048] For example, when particles pass through the path of the measurement area M corresponding to the light receiving surface of the photoelectric conversion element D ₂₂ in the light detection means 14, the peak value detecting means 16a, 16b, 16c are particles the measurement region M During the passage, the output voltages of the photoelectric conversion elements D ₁₁ , D ₁₂ , D ₁₃ , D ₂₁ ,..., D ₃₃ according to the scattered light Ls of the particles are sampled to detect the peak value.

In this case, the intensity of the laser beam in the measurement area M has a distribution (almost Gaussian distribution) in which the intensity is strongest at the center and becomes weaker toward the edge away from the center. because through the strong portions through again weak portions of the heart from the weak light intensity, the photoelectric conversion element D ₂₂ Nomigaryaku pulsed voltage output and the other photoelectric conversion element,
Only the level voltage corresponding to the noise is output.

[0050] Therefore, the peak value of the photoelectric conversion element D ₂₂ E ₂₂
, The ratio to other peak values (E ₁₁ /
If E ₂₂ , E ₁₂ / E ₂₂ ... Are known, the passing position of the particles in the measurement region M can be identified two-dimensionally (YZ plane) by referring to the particle information reference table.

The particle passing position detecting apparatus according to the third embodiment of the present invention has a flow cell 2 as shown in FIG.
1, laser light source 22, condensing optical system 23, trap 20,
It comprises a photoelectric conversion element array 24 and a processing device 25.

The flow cell 21 is made of a transparent member and has a straight flow path 21a (Y direction) having a predetermined length. Here, the cross-sectional shape of the flow cell 21 is a rectangular tube shape.
The reason for providing the straight flow path 21a of a predetermined length is the same as in the case of the flow cell 1 of the particle passage position detecting device according to the first embodiment of the present invention.

The laser light source 22 irradiates a predetermined portion of the linear flow path 21a of the flow cell 21 with a laser beam La to form an irradiation area. Here, the optical axis (X direction) of the laser beam La intersects the straight flow path 21a (Y direction).

The condensing optical system 23 has an optical axis (X direction) coinciding with the optical axis of the laser light source 22, and a predetermined area M (hereinafter referred to as a measurement area M) in the irradiation area shown in FIG. Is provided with a function of condensing the scattered light Ls generated in.

The photoelectric conversion element array 24 is composed of three photoelectric conversion elements 24a, 24b and 24c, each light receiving surface being perpendicular to the optical axis (X direction) of the condensing optical system 23 and the central axis of the flow path. (Y direction) and a Z direction perpendicular to the laser optical axis (X direction). Photoelectric conversion elements 24a, 24
b and 24c convert the scattered light Ls emitted while the particles pass through the measurement region M into a voltage.

The trap 20 located on the optical axis of the condensing optical system 23 prevents the light source light La of the laser light source 22 from directly entering the photoelectric conversion element array 24. As a result, only the scattered light Ls emitted by the particles passing through the flow path 21a enters the photoelectric conversion element 24.

The processing device 25 outputs the peak values (pulse heights) Ea, Eb, and Ev of the voltages output by the three photoelectric conversion elements 24a, 24b, and 24c while the particles pass through the measurement area M.
Peak value detecting means 26a, 26b, 26 for detecting Ec
c and position detecting means 2 for creating a particle information reference table
7

In the third embodiment of the present invention, as voltage detecting means, peak value detecting means 26a, 26b for detecting peak values Ea, Eb, Ec of voltages output from photoelectric conversion elements 24a, 24b, 24c, respectively. , 26c, but not necessarily the peak value.
The output voltages of 4a, 24b, and 24c may be detected at the same timing, and the output voltages may be used in subsequent arithmetic processing. Further, as the voltage detecting means, the photoelectric conversion elements 24a,
The output voltages of 24b and 24c may be integrated and output for a predetermined time.

The position detecting means 27 includes an arithmetic unit 27a and a storage unit 27b. First, the arithmetic unit 27a performs the following arithmetic processes (1) and (2), and stores the result in the storage unit 2.
7b to create a particle information reference table. (1) The ratio Ea / Eb of the output voltage Ea of the peak value detecting means 26a to the output voltage Eb of the peak value detecting means 26b
Is calculated. (2) Ratio Ec / Eb of output voltage Ec of peak value detecting means 26c to output voltage Eb of peak value detecting means 26b
Is calculated.

The operation of the particle passing position detecting device according to the third embodiment of the present invention will be described. As shown in FIG. 12, a fluid containing particles flows into the flow cell 21 from the direction of arrow A. At this time, each photoelectric conversion element 24a, 24b, 2 of the photoelectric conversion element array 24 depends on which position in the measurement area M the particle passes.
4c output waveforms are various. In the case of the photoelectric conversion element array 24 including three photoelectric conversion elements 24a, 24b, and 24c, there are five main types of passing patterns.

First, when the standard particles pass through the center Mc of the measurement area M shown in FIG. 12, the spot S of the scattered light Ls by the standard particles is, as shown in FIG. It appears only in the photoelectric conversion element 24b at the center of 24 and moves in the direction of the arrow. At this time, the output waveform (relationship between time t and voltage E) of each of the photoelectric conversion elements 24a, 24b, 24c is as shown in FIG. That is, only the photoelectric conversion element 24b outputs a substantially pulse-like voltage (peak value Eb) corresponding to the scattered light Ls of the standard particles passing through the center Mc of the measurement area M for a certain time (from time t1 to time t2). However, the other photoelectric conversion elements 24a and 24c output only approximately level voltages (peak values Ea and Ec) corresponding to noise.

Next, when the standard particles pass through one end Ms of the measurement area M shown in FIG. 12, the spot S of the scattered light Ls by the standard particles is photoelectrically converted as shown in FIG. It appears only in the photoelectric conversion element 24a at one end of the element array 24 and moves in the direction of the arrow. At this time, the output waveform (time t and voltage E of each photoelectric conversion element 24a, 24b, 24c)
14B) is as shown in FIG. That is,
A substantially pulse-shaped voltage (peak value E) corresponding to the scattered light Ls of the standard particles that passes only one end Ms of the measurement area M for a certain period of time (from time t3 to time t4).
a), and the other photoelectric conversion elements 24b and 24c output only approximately level voltages (peak values Eb and Ec) corresponding to noise.

Similarly, when the standard particles pass through the other end Ms (a position symmetrical to the one end Ms) of the measurement area M shown in FIG. 12, the spot S of the scattered light Ls by the standard particles is
As shown in FIG. 15A, only the photoelectric conversion element 24c at the other end of the photoelectric conversion element array 24 appears and moves in the direction of the arrow. At this time, each of the photoelectric conversion elements 24a, 24b, 24
The output waveform of c (the relationship between time t and voltage E) is shown in FIG.
The result is as shown in FIG. That is, only the photoelectric conversion element 24c moves the other end Ms of the measurement area M for a certain time (time t3
To a time t4), outputs a substantially pulse-like voltage (peak value Ec) corresponding to the scattered light Ls of the standard particles passing through, and the other photoelectric conversion elements 24a and 24b output a substantially level voltage (peak value Ea) corresponding to noise. , Eb).

Further, when the standard particles pass through one path Mm of the measurement area M shown in FIG. 12, the spot S of the scattered light Ls by the standard particles is, as shown in FIG. It appears over the boundary between the photoelectric conversion element 24a and the photoelectric conversion element 24b and moves in the direction of the arrow. At this time, the output waveform (relationship between time t and voltage E) of each of the photoelectric conversion elements 24a, 24b, 24c is as shown in FIG. That is, the voltage (peak value Ea, peak value Ea,) corresponding to the scattered light Ls of the standard particles that the photoelectric conversion elements 24a and 24b pass through one path Mm of the measurement area M for a certain time (from time t5 to time t6). Eb), and the photoelectric conversion element 24c outputs only a substantially level voltage (peak value Ec) corresponding to the noise.

Similarly, when the standard particle passes through another path Mm (a position symmetrical to one path Mm) of the measurement area M shown in FIG. 12, the spot S of the scattered light Ls by the standard particle is
As shown in FIG. 17 (a), it appears over the boundary between the photoelectric conversion elements 24b and 24c and moves in the direction of the arrow. At this time, each photoelectric conversion element 24a, 24b, 2
4c (the relationship between time t and voltage E) is shown in FIG.
The result is as shown in FIG. That is, the photoelectric conversion elements 24b,
A substantially pulse-like voltage (peak values Eb, Ec) corresponding to the scattered light Ls of the standard particles that passes through the other path Mm of the measurement area M for a certain time (from time t5 to time t6) is output. The conversion element 24a outputs only a substantially level voltage (peak value Ea) corresponding to the noise.

Then, the position detecting means 27
As shown in (a), when the spot S appears only in the central photoelectric conversion element 24b, the arithmetic unit 17a calculates the ratio Ea / Eb of the peak voltage Ea of the photoelectric conversion element 24a to the peak voltage Eb of the photoelectric conversion element 24b. And Ea
<Eb, the ratio Ea / Eb is almost zero (Ea
/ Eb ≒ 0) is output and stored in the storage unit 27b.
Further, in the calculation unit 27a, the ratio Ec / Eb of the peak voltage Ec of the photoelectric conversion element 24c to the peak voltage Eb of the photoelectric conversion element 24b is calculated, and since Ec <Eb,
A value of approximately zero (Ec / Eb ≒ 0) is output as the ratio Ec / Eb and stored in the storage unit 27b.

In the position detecting means 27, FIG.
As shown in (a), when the spot S appears only on the photoelectric conversion element 24a at one end, the arithmetic unit 27a calculates the ratio Ea / Eb of the peak voltage Ea of the photoelectric conversion element 24a to the peak voltage Eb of the photoelectric conversion element 24b. And Ea
> Eb, a very large value (Ea / Eb ≒ ∞) is output as the ratio Ea / Eb and stored in the storage unit 27b. Similarly, the ratio Ec / E of the peak voltage Ec of the photoelectric conversion element 24c to the peak voltage Eb of the photoelectric conversion element 24b.
b, and Ec ≒ Eb, so that a value of about 1 (Ea / Eb ≒ 1) is output as the ratio Ea / Eb, and the storage unit 27b
To memorize.

In the position detecting means 27, FIG.
As shown in (a), when the spot S appears only in the photoelectric conversion element 24c at the other end, the arithmetic unit 27a calculates a ratio Ea / Pe of the peak voltage Ea of the photoelectric conversion element 24a to the peak voltage Eb of the photoelectric conversion element 24b. Eb is calculated and Ea
Since ≒ Eb, the ratio Ea / Eb is about 1 (Ea / Eb).
The value of b ≒ 1) is output and stored in the storage unit 27b. Similarly, the ratio Ec / Eb of the peak voltage Ec of the photoelectric conversion element 24c to the peak voltage Eb of the photoelectric conversion element 24b is calculated, and since Ec> Eb, a very large value (Ec / Eb ≒) is obtained as the ratio Ec / Eb. ∞) is output and stored in the storage unit 27b.

Next, in the position detecting means 27, FIG.
As shown in (a), when the spot S appears over the boundary between the photoelectric conversion element 24a and the photoelectric conversion element 24b,
The calculation unit 27a calculates the ratio Ea / Eb of the peak voltage Ea of the photoelectric conversion element 24a to the peak voltage Eb of the photoelectric conversion element 24b. Since Ea ≒ Eb, the ratio Ea
A value of about 1 (Ea / Eb ≒ 1) is output as / Eb and stored in the storage unit 27b. Similarly, the ratio Ec / Eb of the peak voltage Ec of the photoelectric conversion element 24c to the peak voltage Eb of the photoelectric conversion element 24b is calculated. Since Ec <Eb, the ratio Ec / Eb is almost zero (Ec / Eb ≒ 0). Is output and stored in the storage unit 27b.

In the position detecting means 27, FIG.
As shown in (a), when the spot S appears over the boundary between the photoelectric conversion element 24b and the photoelectric conversion element 24c,
The calculation unit 27a calculates the ratio Ea / Eb of the peak voltage Ea of the photoelectric conversion element 24a to the peak voltage Eb of the photoelectric conversion element 24b. Since Ea <Eb, the ratio Ea
A value of almost zero (Ec / Eb ≒ 0) is output as / Eb and stored in the storage unit 27b. Similarly, the photoelectric conversion element 2
The ratio Ec / Eb of the peak voltage Ec of the photoelectric conversion element 24c to the peak voltage Eb of 4b is calculated, and since Ec ≒ Eb, a value of about 1 (Ec / Eb ≒ 1) is output as the ratio Ec / Eb, It is stored in the storage unit 27b.

Note that the reference voltage is the voltage of the photoelectric conversion element 2.
4b other than the peak voltage Eb of 4b,
The peak voltages Ea and Ec of 24c may be used, or the sum of each peak voltage (Ea + Eb + Ec) may be used. The point is not the absolute value of the peak voltage of the photoelectric conversion elements 24a, 24b, 24c, but the respective photoelectric conversion elements 24a, 242 with respect to the reference voltage.
This is because the accuracy is higher when the position of the spot S of the scattered light Ls by the standard particles is obtained from the ratio (ratio) of the peak voltages of 4b and 24c.

In the above five cases, FIG.
A particle information reference table can be created in the case where the reference voltage is the peak voltage Eb of the photoelectric conversion element 24b, similar to the particle information reference table shown in FIG. Therefore, the photoelectric conversion element 24
If the ratio Ea / Eb of the peak voltage Ea of the photoelectric conversion element 24a to the peak voltage Eb of b, and the ratio Ec / Eb of the peak voltage Ec of the photoelectric conversion element 24c to the peak voltage Eb of the photoelectric conversion element 24b are known, refer to the particle information. By referring to the table, the passing position of the particles in the measurement region M in the Z direction can be identified from among five types.

In addition to the above-mentioned five passing patterns, the measurement area M where the spot S appears over the boundary between the photoelectric conversion elements 24a and 24b or the boundary between the photoelectric conversion elements 24b and 24c. The peak voltage Ea of the photoelectric conversion element 24a with respect to the peak voltage Eb of the photoelectric conversion element 24b
Ratio Ea / Eb and the peak voltage E of the photoelectric conversion element 24b.
b, the ratio E of the peak voltage Ec of the photoelectric conversion element 24c to
If c / Eb is known, the value of the ratio Ea / Eb and the ratio Ec / Eb
By applying the value of to the particle information lookup table,
The position at which the particles pass in the Z direction in the measurement region M can be identified.

The present invention is not limited to the above embodiment of the present invention. For example, as the overall shape of the flow cell, L-shaped flow cells 1 and 11 and a linear flow cell 21 are used. May be any shape as long as it can be arranged so that the central axis of the flow path and the optical axis of the light collecting optical system coincide. Therefore, the overall shape of the flow cell may be bent or curved as long as the optical relationship between the laser light La and the scattered light Ls is not affected.

Although the flow cell has a rectangular cross section in the above embodiment of the invention, it may have a circular cross section.

Further, according to the present invention, the light receiving surface of the light detecting means composed of a plurality of photoelectric conversion elements is arranged perpendicular to the center axis of the flow path or the laser optical axis, and the particle passage position in the flow path and the particle The intensity distribution of the scattered light was detected. However, if only the particle passage position in the flow path is detected without detecting the intensity distribution of the scattered light of the particles, the light receiving surface of the light detection means should be perpendicular to the center axis of the flow path and the laser optical axis. They can also be placed.

[0077]

As described above, according to the first aspect of the present invention, particles are not affected by the intensity of the scattered light of passing particles due to the laser light intensity distribution in the measurement area irradiated with the laser light. The position of the passage that has passed can be detected.

According to the second aspect of the present invention, the position of the flow path through which the particles pass is not affected by the intensity of the scattered light intensity of the passing particles due to the laser light intensity distribution in the measurement area irradiated with the laser light. Can be detected.

According to the third aspect of the invention, the position of the flow path through which the particles pass is not affected by the intensity of the scattered light intensity of the passing particles due to the laser light intensity distribution in the measurement area irradiated with the laser light. It can be detected in two dimensions.

According to the fourth aspect of the present invention, the position of the flow path through which the particles pass is not affected by the intensity of the scattered light intensity of the passing particles due to the laser light intensity distribution in the measurement area irradiated with the laser light. Can be detected.

According to the fifth aspect of the present invention, it is possible to detect the position of the flow path through which the particles pass without being influenced by the intensity of the scattered light intensity of the particles accompanying the laser light intensity distribution in the measurement area.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a particle passing position detecting device according to a first embodiment of the present invention.

FIG. 2 is a plan sectional view of a measurement region irradiated with laser light in FIG.

FIG. 3 is a longitudinal sectional view of a measurement region irradiated with laser light in FIG.

FIG. 4 is a diagram showing a light receiving state (a) of the photoelectric conversion element array and an output waveform (b) at that time in FIG.

FIG. 5 is a diagram showing a light receiving state (a) of the photoelectric conversion element array and an output waveform (b) at that time in FIG.

FIG. 6 is a diagram showing a light receiving state (a) of the photoelectric conversion element array and an output waveform (b) at that time in FIG.

FIG. 7 is a diagram showing a light receiving state (a) of the photoelectric conversion element array and an output waveform (b) at that time in FIG.

8 is a diagram showing a light receiving state (a) of the photoelectric conversion element array and an output waveform (b) at that time in FIG.

FIG. 9 is a diagram showing a particle information reference table.

FIG. 10 is a configuration diagram of a particle passage position detecting device according to a second embodiment of the present invention.

FIG. 11 is a configuration diagram of a particle passage position detecting device according to a third embodiment of the present invention.

12 is a longitudinal sectional view of a measurement region irradiated with laser light in FIG.

13 is a diagram showing a light receiving state (a) of the photoelectric conversion element array and an output waveform (b) at that time in FIG.

14 is a diagram showing a light receiving state (a) of the photoelectric conversion element array and an output waveform (b) at that time in FIG.

15 is a diagram showing a light receiving state (a) of the photoelectric conversion element array and an output waveform (b) at that time in FIG.

FIG. 16 is a diagram showing a light receiving state (a) of the photoelectric conversion element array and an output waveform (b) at that time in FIG.

17 is a diagram showing a light receiving state (a) of the photoelectric conversion element array and an output waveform (b) at that time in FIG.

FIG. 18 is a configuration diagram of a conventional light scattering type particle counting device.

[Explanation of symbols]

1, 11, 21, ... flow cells, 1a, 11a, 21a ...
Linear flow path, 2, 12, 22 ... laser light source, 3, 13, 2
3 ... Condensing optical system (condensing means), 4,24 ... Photoelectric conversion element array, 4a, 4b, 4c, 24a, 24b, 24c ...
Photoelectric conversion element, 5, 15, 25 ... processing device, 6a, 6
b, 6c, 16a, 16b, 16c, 26a, 26b,
26c: peak value detecting means (voltage detecting means), 7, 1
7, 27: position detecting means, 14: light detecting means, 20: trap.

Claims (5)

[Claims] 1. A flow cell having a bent shape made of a transparent member, a laser light source that irradiates a flow path of the flow cell with a laser beam to form a measurement region, and an optical axis coinciding with a center axis of the flow path. Light collecting means for collecting the scattered light of the particles generated in the measurement area and a light detecting means comprising a plurality of photoelectric conversion elements for receiving the scattered light collected by the light collecting means,
Voltage detecting means for detecting output signals of the plurality of photoelectric conversion elements, and position detecting means for comparing the output signals of the voltage detecting means with each other and outputting passage position information of the measurement region through which particles have passed. Characteristic particle passing position detection device. 2. The light detecting means comprising a plurality of photoelectric conversion elements, wherein each light receiving surface is adjacent to a direction perpendicular to a center axis of the flow path and substantially perpendicular to a center axis of the flow path and a laser optical axis. 2. The particle passing position detecting device according to claim 1, wherein the device is a photoelectric conversion element array including N (N is an integer of 2 or more) provided photoelectric conversion elements. 3. The light detecting means comprising a plurality of photoelectric conversion elements, wherein the vertical and horizontal photoelectric conversion elements are composed of V × H (V and H are both integers of 2 or more) photoelectric conversion elements, and each light receiving surface has a flow path. The particle passing position detection device according to claim 1, wherein the particle passage position detection device is perpendicular to a central axis of the particle. 4. A flow cell formed of a transparent member, a laser light source that irradiates a flow path of the flow cell with laser light to form a measurement region, and an optical axis that coincides with a central axis of the laser light. Light collecting means for collecting scattered light of particles generated in the measurement region, a trap located on the optical axis of the light collecting means, and a plurality of photoelectric conversion elements for receiving the scattered light collected by the light collecting means And a voltage detecting means for detecting output signals of the plurality of photoelectric conversion elements, and comparing the output signals of the voltage detecting means with each other to output information on a passing position of the measurement area through which the particles have passed. A particle passing position detecting device comprising a position detecting means. 5. A light detecting means comprising a plurality of photoelectric conversion elements, wherein each light receiving surface is provided adjacently in a direction perpendicular to the laser optical axis and substantially perpendicular to the center axis of the flow path and the laser optical axis. N
5. The particle passing position detecting device according to claim 4, wherein the photoelectric conversion element array comprises (N is an integer of 2 or more) photoelectric conversion elements.